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Sample records for non-native managed coniferous

  1. Managing conflicts arising from fisheries enhancements based on non-native fishes in southern Africa.

    Science.gov (United States)

    Ellender, B R; Woodford, D J; Weyl, O L F; Cowx, I G

    2014-12-01

    Southern Africa has a long history of non-native fish introductions for the enhancement of recreational and commercial fisheries, due to a perceived lack of suitable native species. This has resulted in some important inland fisheries being based on non-native fishes. Regionally, these introductions are predominantly not benign, and non-native fishes are considered one of the main threats to aquatic biodiversity because they affect native biota through predation, competition, habitat alteration, disease transfer and hybridization. To achieve national policy objectives of economic development, food security and poverty eradication, countries are increasingly looking towards inland fisheries as vehicles for development. As a result, conflicts have developed between economic and conservation objectives. In South Africa, as is the case for other invasive biota, the control and management of non-native fishes is included in the National Environmental Management: Biodiversity Act. Implementation measures include import and movement controls and, more recently, non-native fish eradication in conservation priority areas. Management actions are, however, complicated because many non-native fishes are important components in recreational and subsistence fisheries that contribute towards regional economies and food security. In other southern African countries, little attention has focussed on issues and management of non-native fishes, and this is cause for concern. This paper provides an overview of introductions, impacts and fisheries in southern Africa with emphasis on existing and evolving legislation, conflicts, implementation strategies and the sometimes innovative approaches that have been used to prioritize conservation areas and manage non-native fishes.

  2. Setting Priorities for Monitoring and Managing Non-native Plants: Toward a Practical Approach

    Science.gov (United States)

    Koch, Christiane; Jeschke, Jonathan M.; Overbeck, Gerhard E.; Kollmann, Johannes

    2016-09-01

    Land managers face the challenge to set priorities in monitoring and managing non-native plant species, as resources are limited and not all non-natives become invasive. Existing frameworks that have been proposed to rank non-native species require extensive information on their distribution, abundance, and impact. This information is difficult to obtain and often not available for many species and regions. National watch or priority lists are helpful, but it is questionable whether they provide sufficient information for environmental management on a regional scale. We therefore propose a decision tree that ranks species based on more simple albeit robust information, but still provides reliable management recommendations. To test the decision tree, we collected and evaluated distribution data from non-native plants in highland grasslands of Southern Brazil. We compared the results with a national list from the Brazilian Invasive Species Database for the state to discuss advantages and disadvantages of the different approaches on a regional scale. Out of 38 non-native species found, only four were also present on the national list. If management would solely rely on this list, many species that were identified as spreading based on the decision tree would go unnoticed. With the suggested scheme, it is possible to assign species to active management, to monitoring, or further evaluation. While national lists are certainly important, management on a regional scale should employ additional tools that adequately consider the actual risk of non-natives to become invasive.

  3. Non-native megaherbivores: the case for novel function to manage plant invasions on islands.

    Science.gov (United States)

    Hansen, Dennis M

    2015-07-20

    There is a heated debate about whether all non-native species are 'guilty until proven innocent', or whether some should be accepted or even welcomed. Further fanning the flames, I here present a case where introductions of carefully vetted, non-native species could provide a net conservation benefit. On many islands, native megaherbivores (flightless birds, tortoises) recently went extinct. Here, rewilding with carefully selected non-native species as ecological replacements is increasingly considered a solution, reinstating a herbivory regime that largely benefits the native flora. Based on these efforts, I suggest that restoration practitioners working on islands without a history of native megaherbivores that are threatened by invasive plants should consider introducing a non-native island megaherbivore, and that large and giant tortoises are ideal candidates. Such tortoises would be equally useful on islands where eradication of invasive mammals has led to increased problems with invasive plants, or on islands that never had introduced mammalian herbivores, but where invasive plants are a problem. My proposal may seem radical, but the reversibility of using giant tortoises means that nothing is lost from trying, and that indeed much is to be gained. As an easily regulated adaptive management tool, it represents an innovative, hypothesis-driven 'innocent until proven guilty' approach.

  4. Understanding the threats posed by non-native species: public vs. conservation managers.

    Directory of Open Access Journals (Sweden)

    Rodolphe E Gozlan

    Full Text Available Public perception is a key factor influencing current conservation policy. Therefore, it is important to determine the influence of the public, end-users and scientists on the prioritisation of conservation issues and the direct implications for policy makers. Here, we assessed public attitudes and the perception of conservation managers to five non-native species in the UK, with these supplemented by those of an ecosystem user, freshwater anglers. We found that threat perception was not influenced by the volume of scientific research or by the actual threats posed by the specific non-native species. Media interest also reflected public perception and vice versa. Anglers were most concerned with perceived threats to their recreational activities but their concerns did not correspond to the greatest demonstrated ecological threat. The perception of conservation managers was an amalgamation of public and angler opinions but was mismatched to quantified ecological risks of the species. As this suggests that invasive species management in the UK is vulnerable to a knowledge gap, researchers must consider the intrinsic characteristics of their study species to determine whether raising public perception will be effective. The case study of the topmouth gudgeon Pseudorasbora parva reveals that media pressure and political debate has greater capacity to ignite policy changes and impact studies on non-native species than scientific evidence alone.

  5. Understanding the threats posed by non-native species: public vs. conservation managers.

    Science.gov (United States)

    Gozlan, Rodolphe E; Burnard, Dean; Andreou, Demetra; Britton, J Robert

    2013-01-01

    Public perception is a key factor influencing current conservation policy. Therefore, it is important to determine the influence of the public, end-users and scientists on the prioritisation of conservation issues and the direct implications for policy makers. Here, we assessed public attitudes and the perception of conservation managers to five non-native species in the UK, with these supplemented by those of an ecosystem user, freshwater anglers. We found that threat perception was not influenced by the volume of scientific research or by the actual threats posed by the specific non-native species. Media interest also reflected public perception and vice versa. Anglers were most concerned with perceived threats to their recreational activities but their concerns did not correspond to the greatest demonstrated ecological threat. The perception of conservation managers was an amalgamation of public and angler opinions but was mismatched to quantified ecological risks of the species. As this suggests that invasive species management in the UK is vulnerable to a knowledge gap, researchers must consider the intrinsic characteristics of their study species to determine whether raising public perception will be effective. The case study of the topmouth gudgeon Pseudorasbora parva reveals that media pressure and political debate has greater capacity to ignite policy changes and impact studies on non-native species than scientific evidence alone.

  6. Non-native plant invasions in managed and protected ponderosa pine/Douglas-fir forests of the Colorado Front Range

    Science.gov (United States)

    Fornwalt, P.J.; Kaufmann, M.R.; Huckaby, L.S.; Stoker, J.M.; Stohlgren, T.J.

    2003-01-01

    We examined patterns of non-native plant diversity in protected and managed ponderosa pine/Douglas-fir forests of the Colorado Front Range. Cheesman Lake, a protected landscape, and Turkey Creek, a managed landscape, appear to have had similar natural disturbance histories prior to European settlement and fire protection during the last century. However, Turkey Creek has experienced logging, grazing, prescribed burning, and recreation since the late 1800s, while Cheesman Lake has not. Using the modified-Whittaker plot design to sample understory species richness and cover, we collected data for 30 0.1 ha plots in each landscape. Topographic position greatly influenced results, while management history did not. At both Cheesman Lake and Turkey Creek, low/riparian plots had highest native and non-native species richness and cover; upland plots (especially east/west-facing, south-facing and flat, high plots) had the lowest. However, there were no significant differences between Cheesman Lake and Turkey Creek for native species richness, native species cover, non-native species richness, or non-native species cover for any topographic category. In general, non-native species richness and cover were highly positively correlated with native species richness and/or cover (among other variables). In total, 16 non-native species were recorded at Cheesman Lake and Turkey Creek; none of the 16 non-native species were more common at one site than another. These findings suggest that: (1) areas that are high in native species diversity also contain more non-native species; (2) both protected and managed areas can be invaded by non-native plant species, and at similar intensities; and (3) logging, grazing, and other similar disturbances may have less of an impact on non-native species establishment and growth than topographic position (i.e., in lowland and riparian zones versus upland zones).

  7. Status and management of non-native plant invasion in three of the largest national parks in the United States

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    Scott Abella

    2015-06-01

    Full Text Available Globally, invasion by non-native plants threatens resources that nature reserves are designated to protect. We assessed the status of non-native plant invasion on 1,662, 0.1-ha plots in Death Valley National Park, Mojave National Preserve, and Lake Mead National Recreation Area. These parks comprise 2.5 million ha, 23% of the national park land in the contiguous USA. At least one non-native species inhabited 82% of plots. Thirty-one percent of plots contained one non-native species, 30% two, 17% three, and 4% four to ten non-native species. Red brome (Bromus rubens, an ‘ecosystem engineer’ that alters fire regimes, was most widespread, infesting 60% of plots. By identifying frequency of species through this assessment, early detection and treatment can target infrequent species or minimally invaded sites, while containment strategies could focus on established invaders. We further compared two existing systems for prioritizing species for management and found that a third of species on plots had no rankings available. Moreover, rankings did not always agree between ranking systems for species that were ranked. Presence of multiple non-native species complicates treatment, and while we found that 40% of plots contained both forb and grass invaders, exploiting accelerated phenology of non-natives (compared to native annuals might help manage multi-species invasions. Large sizes of these parks and scale of invasion are formidable challenges for management. Yet, precisely because of their size, these reserves represent opportunities to conserve large landscapes of native species by managing non-native plant invasions.

  8. The relationship between conceptual metaphors and classroom management language: reactions by native and non-native speakers of English

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    Graham Low

    2009-04-01

    Full Text Available The use of the target language to manage a class and organise its work represents one of the few genuinely communicative uses of the target language in many formal foreign-language or bilingual-education teaching situations. It is thus important that both teachers and learners understand and know how to use the key expressions involved. These tend to be highly metaphoric (Low, 2008 with one particularly productive conceptual metaphor involving the JOURNEY (or TRAVEL source domain seemingly standing out. There seems to have been little investigation to date into whether or not learners whose first language is not English actually understand the expressions involved in such classroom management language. Moreover, with the recent growing interest in the area of content-based learning, there is increasing pressure on language teachers, whose first language is not English, to use English as their classroom management language. Our first aim was to look at whether the acceptability judgements for classroom management expressions offered by non-native speaking teachers of English resembled those of native speakers, and whether these judgements reflected corpus findings regarding the frequency of usage in spoken English. To do this, we analysed native and non-native speaker responses to a short questionnaire. Our second aim was to look at how non-native speakers of English perceive the meanings of these expressions, comparing our findings to native speaker judgements and corpus results.

  9. The interactive effects of climate change, riparian management, and a non-native predators on stream-rearing salmon

    Science.gov (United States)

    Lawrence, David J.; Stewart-Koster, Ben; Olden, Julian D.; Ruesch, Aaron S.; Torgersen, Christian E.; Lawler, Joshua J.; Butcher, Don P.; Crown, Julia K.

    2014-01-01

    Predicting how climate change is likely to interact with myriad other stressors that threaten species of conservation concern is an essential challenge in aquatic ecosystems. This study provides a framework to accomplish this task in salmon-bearing streams of the northwestern United States, where land-use related reductions in riparian shading have caused changes in stream thermal regimes, and additional warming from projected climate change may result in significant losses of coldwater fish habitat over the next century. Predatory non-native smallmouth bass have also been introduced into many northwestern streams and their range is likely to expand as streams warm, presenting an additional challenge to the persistence of threatened Pacific salmon. The goal of this work was to forecast the interactive effects of climate change, riparian management, and non-native species on stream-rearing salmon, and to evaluate the capacity of restoration to mitigate these effects. We intersected downscaled global climate forecasts with a local-scale water temperature model to predict mid- and end-of-century temperatures in streams in the Columbia River basin; we compared one stream that is thermally impaired due to the loss of riparian vegetation and another that is cooler and has a largely intact riparian corridor. Using the forecasted stream temperatures in conjunction with fish-habitat models, we predicted how stream-rearing Chinook salmon and bass distributions would change as each stream warmed. In the highly modified stream, end-of-century warming may cause near total loss of Chinook salmon rearing habitat and a complete invasion of the upper watershed by bass. In the less modified stream, bass were thermally restricted from the upstream-most areas. In both systems, temperature increases resulted in higher predicted spatial overlap between stream-rearing Chinook salmon and potentially predatory bass in the early summer (2-4-fold increase) and greater abundance of bass. We

  10. Ecological impacts of non-native species

    Science.gov (United States)

    Wilkinson, John W.

    2012-01-01

    management of non-native species has only just begun but some promising results have already emerged (see below), giving hope to a very difficult conservation issue. This chapter provides an overview of the role of non-native species in amphibian declines and summarizes the current state of knowledge of non-native species that are known, or considered to be, a threat to amphibian species and populations. The biological and socio-economic issues of non-native species control are examined and brief case studies of successful eradication programmes are provided.

  11. Designing English-Medium Classroom Management Course for Non-Natives

    OpenAIRE

    Tuba Gokmenoglu; Sevinç Gelmez-Burakgazi

    2013-01-01

    This qualitative phenomenological research study explores the practices of instructors teaching through the medium of English as a foreign language, in classroom management course. Data collection instruments are semi-structured interviews and the course syllabi. Phenomenological data analysis techniques (bracketing, determining themes) were employed. Results indicate that instructors do not use a specific model for the classroom management course. The challenges faced with design of an Engli...

  12. Designing English-Medium Classroom Management Course for Non-Natives

    Directory of Open Access Journals (Sweden)

    Tuba Gokmenoglu

    2013-03-01

    Full Text Available This qualitative phenomenological research study explores the practices of instructors teaching through the medium of English as a foreign language, in classroom management course. Data collection instruments are semi-structured interviews and the course syllabi. Phenomenological data analysis techniques (bracketing, determining themes were employed. Results indicate that instructors do not use a specific model for the classroom management course. The challenges faced with design of an English-medium instruction such as difficulty in finding cultural course materials, lack of confidence among local students, adaptation of international students and the solutions (dividing the course into two parts: theory and practice; sharing own experiences; using tentative course syllabus of instructors for these challenges were explored, and suggestions for the designers of English-medium courses were discussed

  13. Adding fuel to the fire: the impacts of non-native grass invasion on fire management at a regional scale.

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    Samantha A Setterfield

    Full Text Available BACKGROUND: Widespread invasion by non-native plants has resulted in substantial change in fire-fuel characteristics and fire-behaviour in many of the world's ecosystems, with a subsequent increase in the risk of fire damage to human life, property and the environment. Models used by fire management agencies to assess fire risk are dependent on accurate assessments of fuel characteristics but there is little evidence that they have been modified to reflect landscape-scale invasions. There is also a paucity of information documenting other changes in fire management activities that have occurred to mitigate changed fire regimes. This represents an important limitation in information for both fire and weed risk management. METHODOLOGY/PRINCIPAL FINDINGS: We undertook an aerial survey to estimate changes to landscape fuel loads in northern Australia resulting from invasion by Andropogon gayanus (gamba grass. Fuel load within the most densely invaded area had increased from 6 to 10 t ha(-1 in the past two decades. Assessment of the effect of calculating the Grassland Fire Danger Index (GFDI for the 2008 and 2009 fire seasons demonstrated that an increase from 6 to 10 t ha(-1 resulted in an increase from five to 38 days with fire risk in the 'severe' category in 2008 and from 11 to 67 days in 2009. The season of severe fire weather increased by six weeks. Our assessment of the effect of increased fuel load on fire management practices showed that fire management costs in the region have increased markedly (∼9 times in the past decade due primarily to A. gayanus invasion. CONCLUSIONS/SIGNIFICANCE: This study demonstrated the high economic cost of mitigating fire impacts of an invasive grass. This study demonstrates the need to quantify direct and indirect invasion costs to assess the risk of further invasion and to appropriately fund fire and weed management strategies.

  14. The public and professionals reason similarly about the management of non-native invasive species: a quantitative investigation of the relationship between beliefs and attitudes.

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    Anke Fischer

    Full Text Available Despite continued critique of the idea of clear boundaries between scientific and lay knowledge, the 'deficit-model' of public understanding of ecological issues still seems prevalent in discourses of biodiversity management. Prominent invasion biologists, for example, still argue that citizens need to be educated so that they accept scientists' views on the management of non-native invasive species. We conducted a questionnaire-based survey with members of the public and professionals in invasive species management (n = 732 in Canada and the UK to investigate commonalities and differences in their perceptions of species and, more importantly, how these perceptions were connected to attitudes towards species management. Both native and non-native mammal and tree species were included. Professionals tended to have more extreme views than the public, especially in relation to nativeness and abundance of a species. In both groups, species that were perceived to be more abundant, non-native, unattractive or harmful to nature and the economy were more likely to be regarded as in need of management. While perceptions of species and attitudes towards management thus often differed between public and professionals, these perceptions were linked to attitudes in very similar ways across the two groups. This suggests that ways of reasoning about invasive species employed by professionals and the public might be more compatible with each other than commonly thought. We recommend that managers and local people engage in open discussion about each other's beliefs and attitudes prior to an invasive species control programme. This could ultimately reduce conflict over invasive species control.

  15. The public and professionals reason similarly about the management of non-native invasive species: a quantitative investigation of the relationship between beliefs and attitudes.

    Science.gov (United States)

    Fischer, Anke; Selge, Sebastian; van der Wal, René; Larson, Brendon M H

    2014-01-01

    Despite continued critique of the idea of clear boundaries between scientific and lay knowledge, the 'deficit-model' of public understanding of ecological issues still seems prevalent in discourses of biodiversity management. Prominent invasion biologists, for example, still argue that citizens need to be educated so that they accept scientists' views on the management of non-native invasive species. We conducted a questionnaire-based survey with members of the public and professionals in invasive species management (n = 732) in Canada and the UK to investigate commonalities and differences in their perceptions of species and, more importantly, how these perceptions were connected to attitudes towards species management. Both native and non-native mammal and tree species were included. Professionals tended to have more extreme views than the public, especially in relation to nativeness and abundance of a species. In both groups, species that were perceived to be more abundant, non-native, unattractive or harmful to nature and the economy were more likely to be regarded as in need of management. While perceptions of species and attitudes towards management thus often differed between public and professionals, these perceptions were linked to attitudes in very similar ways across the two groups. This suggests that ways of reasoning about invasive species employed by professionals and the public might be more compatible with each other than commonly thought. We recommend that managers and local people engage in open discussion about each other's beliefs and attitudes prior to an invasive species control programme. This could ultimately reduce conflict over invasive species control.

  16. Chemical ecology and management of bark beetles in western coniferous forests

    Science.gov (United States)

    Christopher J. Fettig

    2013-01-01

    The future looks bright for the development and use of semiochemical-based tools in forests, particularly in remote and sensitive areas where other management techniques (e.g., the use of insecticides) may not be appropriate. This editorial provides an concise overview of chemical ecology and management of bark beetles in western coniferous forests.

  17. English Business Communication Skills Training Needs of Non-Native English-Speaking Managers: A Case in Taiwan.

    Science.gov (United States)

    Tsui, Chia-Jung

    1992-01-01

    Discusses results of a survey of managers in high-technology industry in Taiwan regarding their needs for English business communication skills in the workplace. Finds that English conversation and English telephoning are the most urgently needed training courses. (SR)

  18. Management Effectiveness of a Secondary Coniferous Forest for Landscape Appreciation and Psychological Restoration.

    Science.gov (United States)

    Takayama, Norimasa; Fujiwara, Akio; Saito, Haruo; Horiuchi, Masahiro

    2017-07-18

    We investigated the influence of forest management on landscape appreciation and psychological restoration in on-site settings by exposing respondents to an unmanaged, dense coniferous (crowding) forest and a managed (thinned) coniferous forest; we set the two experimental settings in the forests of the Fuji Iyashinomoroi Woodland Study Center. The respondents were individually exposed to both settings while sitting for 15 min and were required to answer three questionnaires to analyze the psychological restorative effects before and after the experiment (feeling (the Profile of Mood States), affect (the Positive and Negative Affect Schedule), and subjective restorativeness (the Restorative Outcome Scale). To compare landscape appreciation, they were required to answer another two questionnaires only after the experiment, for scene appreciation (the semantic differential scale) and for the restorative properties of each environment (the Perceived Restorativeness Scale). Finally, we obtained these findings: (1) the respondents evaluated each forest environment highly differently and evaluated the thinned forest setting more positively; (2) the respondents' impressions of the two physical environments did not appear to be accurately reflected in their evaluations; (3) forest environments have potential restorative effects whether or not they are managed, but these effects can be partially enhanced by managing the forests.

  19. Management Effectiveness of a Secondary Coniferous Forest for Landscape Appreciation and Psychological Restoration

    Science.gov (United States)

    Fujiwara, Akio; Saito, Haruo; Horiuchi, Masahiro

    2017-01-01

    We investigated the influence of forest management on landscape appreciation and psychological restoration in on-site settings by exposing respondents to an unmanaged, dense coniferous (crowding) forest and a managed (thinned) coniferous forest; we set the two experimental settings in the forests of the Fuji Iyashinomoroi Woodland Study Center. The respondents were individually exposed to both settings while sitting for 15 min and were required to answer three questionnaires to analyze the psychological restorative effects before and after the experiment (feeling (the Profile of Mood States), affect (the Positive and Negative Affect Schedule), and subjective restorativeness (the Restorative Outcome Scale). To compare landscape appreciation, they were required to answer another two questionnaires only after the experiment, for scene appreciation (the semantic differential scale) and for the restorative properties of each environment (the Perceived Restorativeness Scale). Finally, we obtained these findings: (1) the respondents evaluated each forest environment highly differently and evaluated the thinned forest setting more positively; (2) the respondents’ impressions of the two physical environments did not appear to be accurately reflected in their evaluations; (3) forest environments have potential restorative effects whether or not they are managed, but these effects can be partially enhanced by managing the forests. PMID:28718831

  20. Adaptive genetic potential of coniferous forest tree species under climate change: implications for sustainable forest management

    Science.gov (United States)

    Mihai, Georgeta; Birsan, Marius-Victor; Teodosiu, Maria; Dumitrescu, Alexandru; Daia, Mihai; Mirancea, Ionel; Ivanov, Paula; Alin, Alexandru

    2017-04-01

    coniferous species for a sustainable forest management in the context of climate change), financed by the Executive Agency for Higher Education, Research, Development and Innovation Funding, grant number PN-II-PC-PCCA-2013-4-0695.

  1. Defining the impact of non-native species.

    Science.gov (United States)

    Jeschke, Jonathan M; Bacher, Sven; Blackburn, Tim M; Dick, Jaimie T A; Essl, Franz; Evans, Thomas; Gaertner, Mirijam; Hulme, Philip E; Kühn, Ingolf; Mrugała, Agata; Pergl, Jan; Pyšek, Petr; Rabitsch, Wolfgang; Ricciardi, Anthony; Richardson, David M; Sendek, Agnieszka; Vilà, Montserrat; Winter, Marten; Kumschick, Sabrina

    2014-10-01

    Non-native species cause changes in the ecosystems to which they are introduced. These changes, or some of them, are usually termed impacts; they can be manifold and potentially damaging to ecosystems and biodiversity. However, the impacts of most non-native species are poorly understood, and a synthesis of available information is being hindered because authors often do not clearly define impact. We argue that explicitly defining the impact of non-native species will promote progress toward a better understanding of the implications of changes to biodiversity and ecosystems caused by non-native species; help disentangle which aspects of scientific debates about non-native species are due to disparate definitions and which represent true scientific discord; and improve communication between scientists from different research disciplines and between scientists, managers, and policy makers. For these reasons and based on examples from the literature, we devised seven key questions that fall into 4 categories: directionality, classification and measurement, ecological or socio-economic changes, and scale. These questions should help in formulating clear and practical definitions of impact to suit specific scientific, stakeholder, or legislative contexts. © 2014 The Authors. Conservation Biology published by Wiley Periodicals, Inc., on behalf of the Society for Conservation Biology.

  2. Word Durations in Non-Native English

    Science.gov (United States)

    Baker, Rachel E.; Baese-Berk, Melissa; Bonnasse-Gahot, Laurent; Kim, Midam; Van Engen, Kristin J.; Bradlow, Ann R.

    2010-01-01

    In this study, we compare the effects of English lexical features on word duration for native and non-native English speakers and for non-native speakers with different L1s and a range of L2 experience. We also examine whether non-native word durations lead to judgments of a stronger foreign accent. We measured word durations in English paragraphs read by 12 American English (AE), 20 Korean, and 20 Chinese speakers. We also had AE listeners rate the `accentedness' of these non-native speakers. AE speech had shorter durations, greater within-speaker word duration variance, greater reduction of function words, and less between-speaker variance than non-native speech. However, both AE and non-native speakers showed sensitivity to lexical predictability by reducing second mentions and high frequency words. Non-native speakers with more native-like word durations, greater within-speaker word duration variance, and greater function word reduction were perceived as less accented. Overall, these findings identify word duration as an important and complex feature of foreign-accented English. PMID:21516172

  3. 75 FR 60405 - Lincoln National Forest, New Mexico, Integrated Non-Native Invasive Plant Project

    Science.gov (United States)

    2010-09-30

    ... Forest Service Lincoln National Forest, New Mexico, Integrated Non-Native Invasive Plant Project AGENCY... control spread of non- native invasive plants (NNIP) within the LNF. The proposal utilizes several... methods, and adaptive management. Invasive plants designated by the State of New Mexico as noxious weeds...

  4. NATIVE VS NON-NATIVE ENGLISH TEACHERS

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    Masrizal Masrizal

    2013-02-01

    Full Text Available Although the majority of English language teachers worldwide are non-native English speakers (NNS, no research was conducted on these teachers until recently. A pioneer research by Peter Medgyes in 1994 took quite a long time until the other researchers found their interests in this issue. There is a widespread stereotype that a native speaker (NS is by nature the best person to teach his/her foreign language. In regard to this assumption, we then see a very limited room and opportunities for a non native teacher to teach language that is not his/hers. The aim of this article is to analyze the differences among these teachers in order to prove that non-native teachers have equal advantages that should be taken into account. The writer expects that the result of this short article could be a valuable input to the area of teaching English as a foreign language in Indonesia.

  5. Non-natives: 141 scientists object

    NARCIS (Netherlands)

    Simberloff, D.; Van der Putten, W.H.

    2011-01-01

    Supplementary information to: Non-natives: 141 scientists object Full list of co-signatories to a Correspondence published in Nature 475, 36 (2011); doi: 10.1038/475036a. Daniel Simberloff University of Tennessee, Knoxville, Tennessee, USA. dsimberloff@utk.edu Jake Alexander Institute of Integrative

  6. Non-natives: 141 scientists object

    NARCIS (Netherlands)

    Simberloff, D.; Van der Putten, W.H.

    2011-01-01

    Supplementary information to: Non-natives: 141 scientists object Full list of co-signatories to a Correspondence published in Nature 475, 36 (2011); doi: 10.1038/475036a. Daniel Simberloff University of Tennessee, Knoxville, Tennessee, USA. dsimberloff@utk.edu Jake Alexander Institute of Integrative

  7. Non-natives: 141 scientists object

    OpenAIRE

    Simberloff, D.; van der Putten, W. H.

    2011-01-01

    Supplementary information to: Non-natives: 141 scientists object Full list of co-signatories to a Correspondence published in Nature 475, 36 (2011); doi: 10.1038/475036a. Daniel Simberloff University of Tennessee, Knoxville, Tennessee, USA. Jake Alexander Institute of Integrative Biology, Zurich, Switzerland. Fred Allendorf University of Montana, Missoula, Montana, USA. James Aronson CEFE/CNRS, Montpellier, France. Pedro M. Antunes Algoma University, Sault Ste. Marie, Onta...

  8. Soil nematode community under the non-native trees in the Botanic Garden of Petrozavodsk State University

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    Sushchuk Anna

    2016-12-01

    Full Text Available The particularities of soil nematode communities of the rhizosphere of non-native trees were studied in the Botanic Garden of Petrozavodsk State University (Republic of Karelia. Taxonomic diversity, abundance, community structure and ecological indices derived from nematode fauna analysis were used as the evaluation parameters. Nematode fauna included 51 genera, 6 of them were plant parasitic. The dominant eco-trophic group in the nematode community structure of coniferous trees was bacterial feeders; fungal feeders in most cases were observed in the second numbers. The contribution of bacterial feeders was decreased and plant parasites were increased in eco-trophic structure of nematode communities of deciduous trees in compared with coniferous trees. Analysis of ecological indices showed that the state of soil nematode communities reflects complex, structured (stable soil food web in the biocenoses with deciduous trees, and degraded (basal food web – under coniferous trees.

  9. Kalispel Non-Native Fish Suppression Project 2007 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Wingert, Michele; Andersen, Todd [Kalispel Natural Resource Department

    2008-11-18

    Non-native salmonids are impacting native salmonid populations throughout the Pend Oreille Subbasin. Competition, hybridization, and predation by non-native fish have been identified as primary factors in the decline of some native bull trout (Salvelinus confluentus) and westslope cutthroat trout (Oncorhynchus clarki lewisi) populations. In 2007, the Kalispel Natural Resource Department (KNRD) initiated the Kalispel Nonnative Fish Suppression Project. The goal of this project is to implement actions to suppress or eradicate non-native fish in areas where native populations are declining or have been extirpated. These projects have previously been identified as critical to recovering native bull trout and westslope cutthroat trout (WCT). Lower Graham Creek was invaded by non-native rainbow (Oncorhynchus mykiss) and brook trout (Salvelinus fontinalis) after a small dam failed in 1991. By 2003, no genetically pure WCT remained in the lower 700 m of Graham Creek. Further invasion upstream is currently precluded by a relatively short section of steep, cascade-pool stepped channel section that will likely be breached in the near future. In 2008, a fish management structure (barrier) was constructed at the mouth of Graham Creek to preclude further invasion of non-native fish into Graham Creek. The construction of the barrier was preceded by intensive electrofishing in the lower 700 m to remove and relocate all captured fish. Westslope cutthroat trout have recently been extirpated in Cee Cee Ah Creek due to displacement by brook trout. We propose treating Cee Cee Ah Creek with a piscicide to eradicate brook trout. Once eradication is complete, cutthroat trout will be translocated from nearby watersheds. In 2004, the Washington Department of Fish and Wildlife (WDFW) proposed an antimycin treatment within the subbasin; the project encountered significant public opposition and was eventually abandoned. However, over the course of planning this 2004 project, little public

  10. Bird communities of coniferous forests in the Acadian region: their habitat associations and responses to forest management

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual report documents project activities for bird communities of coniferous forests in the Acadian Region. The objectives of this project are to: 1 quantify...

  11. Bird communities of coniferous forests in the Acadian region: their habitat associations and responses to forest management

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual report documents project activities for bird communities of coniferous forests in the Acadian Region. The objectives of this project are to: (1) quantify...

  12. [FY 2015 progress report]: Bird Communities of Coniferous Forests in the Acadian Region: Their Responses to Management and Habitat Associations

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This FY2015 progress report documents project activities for bird communities of coniferous forests in the Acadian Region. The goal of the project is to examine...

  13. Bird communities of coniferous forests in the Acadian region: their habitat associations and responses to forest management

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual report documents project activities for bird communities of coniferous forests in the Acadian Region. The objectives of this project are to: (1) quantify...

  14. Bird communities of coniferous forests in the Acadian region: their habitat associations and responses to forest management

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual report documents project activities for bird communities of coniferous forests in the Acadian Region. The objectives of this project are to: 1 quantify...

  15. [FY 2014 progress report]: Bird Communities of Coniferous Forests in the Acadian Region: Their Responses to Management and Habitat Associations

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This FY2014 progress report documents project activities for bird communities of coniferous forests in the Acadian Region. The goal of the project is to examine...

  16. Exploring Public Perception of Non-native Species from a Visions of Nature Perspective

    Science.gov (United States)

    Verbrugge, Laura N. H.; Van den Born, Riyan J. G.; Lenders, H. J. Rob

    2013-12-01

    Not much is known about lay public perceptions of non-native species and their underlying values. Public awareness and engagement, however, are important aspects in invasive species management. In this study, we examined the relations between the lay public's visions of nature, their knowledge about non-native species, and their perceptions of non-native species and invasive species management with a survey administered in the Netherlands. Within this framework, we identified three measures for perception of non-native species: perceived risk, control and engagement. In general, respondents scored moderate values for perceived risk and personal engagement. However, in case of potential ecological or human health risks, control measures were supported. Respondents' images of the human-nature relationship proved to be relevant in engagement in problems caused by invasive species and in recognizing the need for control, while images of nature appeared to be most important in perceiving risks to the environment. We also found that eradication of non-native species was predominantly opposed for species with a high cuddliness factor such as mammals and bird species. We conclude that lay public perceptions of non-native species have to be put in a wider context of visions of nature, and we discuss the implications for public support for invasive species management.

  17. Non-native fishes in Florida freshwaters: a literature review and synthesis

    Science.gov (United States)

    Schofield, Pamela J.; Loftus, William F.

    2015-01-01

    Non-native fishes have been known from freshwater ecosystems of Florida since the 1950s, and dozens of species have established self-sustaining populations. Nonetheless, no synthesis of data collected on those species in Florida has been published until now. We searched the literature for peer-reviewed publications reporting original data for 42 species of non-native fishes in Florida that are currently established, were established in the past, or are sustained by human intervention. Since the 1950s, the number of non-native fish species increased steadily at a rate of roughly six new species per decade. Studies documented (in decreasing abundance): geographic location/range expansion, life- and natural-history characteristics (e.g., diet, habitat use), ecophysiology, community composition, population structure, behaviour, aquatic-plant management, and fisheries/aquaculture. Although there is a great deal of taxonomic uncertainty and confusion associated with many taxa, very few studies focused on clarifying taxonomic ambiguities of non-native fishes in the State. Most studies were descriptive; only 15 % were manipulative. Risk assessments, population-control studies and evaluations of effects of non-native fishes were rare topics for research, although they are highly valued by natural-resource managers. Though some authors equated lack of data with lack of effects, research is needed to confirm or deny conclusions. Much more is known regarding the effects of lionfish (Pterois spp.) on native fauna, despite its much shorter establishment time. Natural-resource managers need biological and ecological information to make policy decisions regarding non-native fishes. Given the near-absence of empirical data on effects of Florida non-native fishes, and the lengthy time-frames usually needed to collect such information, we provide suggestions for data collection in a manner that may be useful in the evaluation and prediction of non-native fish effects.

  18. An Ecosystem-Service Approach to Evaluate the Role of Non-Native Species in Urbanized Wetlands

    Science.gov (United States)

    Yam, Rita S. W.; Huang, Ko-Pu; Hsieh, Hwey-Lian; Lin, Hsing-Juh; Huang, Shou-Chung

    2015-01-01

    Natural wetlands have been increasingly transformed into urbanized ecosystems commonly colonized by stress-tolerant non-native species. Although non-native species present numerous threats to natural ecosystems, some could provide important benefits to urbanized ecosystems. This study investigated the extent of colonization by non-native fish and bird species of three urbanized wetlands in subtropical Taiwan. Using literature data the role of each non-native species in the urbanized wetland was evaluated by their effect (benefits/damages) on ecosystem services (ES) based on their ecological traits. Our sites were seriously colonized by non-native fishes (39%–100%), but wetland ES. Our results indicated the importance of non-native fishes in supporting ES by serving as food source to fish-eating waterbirds (native, and migratory species) due to their high abundance, particularly for Oreochromis spp. However, all non-native birds are regarded as “harmful” species causing important ecosystem disservices, and thus eradication of these bird-invaders from urban wetlands would be needed. This simple framework for role evaluation of non-native species represents a holistic and transferable approach to facilitate decision making on management priority of non-native species in urbanized wetlands. PMID:25860870

  19. Movements, cover-type selection, and survival of fledgling Ovenbirds in managed deciduous and mixed coniferous-deciduous forests

    Science.gov (United States)

    Streby, Henry M.; Andersen, David E.

    2013-01-01

    We used radio telemetry to monitor movements, cover-type selection, and survival for fledglings of the mature-forest nesting Ovenbird (Seiurus aurocapilla) at two managed forest sites in north-central Minnesota. Both sites contained forested wetlands, regenerating clearcut stands of various ages, and logging roads, but differed in mature forest composition; one deciduous with open understory, and the other mixed coniferous-deciduous with dense understory. We used compositional analysis, modified to incorporate age-specific limitations in fledgling movements, to assess cover-type selection by fledglings throughout the dependent (on adult care) post-fledging period. Compared to those that were depredated, fledglings from nests in deciduous forest that survived the early post-fledging period had more older (sapling-dominated) clearcut available, directed movements toward older clearcuts and forested wetlands, and used older clearcuts more than other cover types relative to availability. Fledglings that were depredated had more young (shrub-dominated) clearcut and unpaved logging road available, and used mature forest and roads more than expected based on availability. For birds from nests in mixed mature forest with dense understory, movements and cover-type selection were similar between fledglings that survived and those that were depredated. However, fledglings that were depredated at that site also had more young clearcut available than fledglings that survived. We conclude that Ovenbird fledgling survival is influenced by distance of their nest to various non-nesting cover types, and by the subsequent selection among those cover types, but that the influence of non-nesting cover types varies depending on the availability of dense understory vegetation in mature forest.

  20. Comments on the proposed intensive forest management in the temperate coniferous forests

    Energy Technology Data Exchange (ETDEWEB)

    Khan, A.A.

    1979-01-01

    Intensive forest management is being introduced in the moist temperate forests of the Kaghan Valley, N. Pakistan, based on a combination of a shelterwood system with clear felling of trees down to an advanced growth of up to 12 inches, with artificial regeneration, mainly by planting of Cedrus deodara and Pinus wallichiana. Possible adverse effects of the proposed system (e.g. leaching of soil nutrients following clear felling) are briefly discussed. A more cautious approach, employing natural regeneration, is recommended.

  1. Defining the Impact of Non-Native Species

    OpenAIRE

    Jeschke, Jonathan M; Bacher, Sven; Tim M Blackburn; Dick, Jaimie T. A.; Essl, Franz; Evans, Thomas; Gaertner, Mirijam; Hulme, Philip E.; Kühn, Ingolf; Mrugała, Agata; Pergl, Jan; Pyšek, Petr; Rabitsch, Wolfgang; Ricciardi, Anthony; Richardson, David M.

    2014-01-01

    Non-native species cause changes in the ecosystems to which they are introduced. These changes, or some of them, are usually termed impacts; they can be manifold and potentially damaging to ecosystems and biodiversity. However, the impacts of most non-native species are poorly understood, and a synthesis of available information is being hindered because authors often do not clearly define impact. We argue that explicitly defining the impact of non-native species will promote progress toward ...

  2. Dynamics and pattern of a managed coniferous forest landscape in Oregon

    Science.gov (United States)

    Spies, Thomas A.; Ripple, William J.; Bradshaw, G. A.

    1995-01-01

    We examined the process of fragmentation in a managed forest landscape by comparing rates and patterns of disturbance (primarily clear-cutting) and regrowth between 1972 and 1988 using Landsat imagery. A 2589-km(exp 2) managed forest landscape in western Oregon was classified into two forest types, closed-canopy conifer forest (CF) (typically, greater than 60% conifer cover) and other forest and nonforest types (OT) (typically, less than 40 yr old or deciduous forest). The percentage of CF declined from 71 to 58% between 1972 and 1988. Declines were greatest on private land, least in wilderness, and intermediate in public nonwilderness. High elevations (greater than 914 m) maintained a greater percentage of CF than lower elevations (less than 914 m). The percentage of the area at the edge of the two cover types increased on all ownerships and in both elevational zones, whereas the amount of interior habitat (defined as CF at least 100 m from OT) decreased on all ownerships and elevational zones. By 1988 public lands contained approximately 45% interior habitat while private lands had 12% interior habitat. Mean interior patch area declined from 160 to 62 ha. The annual rate of disturbance (primarily clear-cutting) for the entire area including the wilderness was 1.19%, which corresponds to a cutting rotation of 84 yr. The forest landscape was not in a steady state or regulated condition which is not projected to occur for at least 40 yr under current forest plans. Variability in cutting rates within ownerships was higher on private land than on nonreserve public land. However, despite the use of dispersed cutting patterns on public land, spatial patterns of cutting and remnant forest patches were nonuniform across the entire public ownership. Large remaining patches (less than 5000 ha) of contiguous interior forest were restricted to public lands designated for uses other than timber production such as wilderness areas and research natural areas.

  3. Defining the Impact of Non-Native Species

    Science.gov (United States)

    Jeschke, Jonathan M; Bacher, Sven; Blackburn, Tim M; Dick, Jaimie T A; Essl, Franz; Evans, Thomas; Gaertner, Mirijam; Hulme, Philip E; Kühn, Ingolf; Mrugała, Agata; Pergl, Jan; Pyšek, Petr; Rabitsch, Wolfgang; Ricciardi, Anthony; Richardson, David M; Sendek, Agnieszka; VilÀ, Montserrat; Winter, Marten; Kumschick, Sabrina

    2014-01-01

    Non-native species cause changes in the ecosystems to which they are introduced. These changes, or some of them, are usually termed impacts; they can be manifold and potentially damaging to ecosystems and biodiversity. However, the impacts of most non-native species are poorly understood, and a synthesis of available information is being hindered because authors often do not clearly define impact. We argue that explicitly defining the impact of non-native species will promote progress toward a better understanding of the implications of changes to biodiversity and ecosystems caused by non-native species; help disentangle which aspects of scientific debates about non-native species are due to disparate definitions and which represent true scientific discord; and improve communication between scientists from different research disciplines and between scientists, managers, and policy makers. For these reasons and based on examples from the literature, we devised seven key questions that fall into 4 categories: directionality, classification and measurement, ecological or socio-economic changes, and scale. These questions should help in formulating clear and practical definitions of impact to suit specific scientific, stakeholder, or legislative contexts. Definiendo el Impacto de las Especies No-Nativas Resumen Las especies no-nativas pueden causar cambios en los ecosistemas donde son introducidas. Estos cambios, o algunos de ellos, usualmente se denominan como impactos; estos pueden ser variados y potencialmente dañinos para los ecosistemas y la biodiversidad. Sin embargo, los impactos de la mayoría de las especies no-nativas están pobremente entendidos y una síntesis de información disponible se ve obstaculizada porque los autores continuamente no definen claramente impacto. Discutimos que definir explícitamente el impacto de las especies no-nativas promoverá el progreso hacia un mejor entendimiento de las implicaciones de los cambios a la biodiversidad y los

  4. Non-native educators in English language teaching

    CERN Document Server

    Braine, George

    2013-01-01

    The place of native and non-native speakers in the role of English teachers has probably been an issue ever since English was taught internationally. Although ESL and EFL literature is awash, in fact dependent upon, the scrutiny of non-native learners, interest in non-native academics and teachers is fairly new. Until recently, the voices of non-native speakers articulating their own concerns have been even rarer. This book is a response to this notable vacuum in the ELT literature, providing a forum for language educators from diverse geographical origins and language backgrounds. In additio

  5. Non-native speech perception in adverse conditions: A review

    NARCIS (Netherlands)

    Garcia Lecumberri, M.L.; Cooke, M.P.; Cutler, A.

    2010-01-01

    If listening in adverse conditions is hard, then listening in a foreign language is doubly so: non-native listeners have to cope with both imperfect signals and imperfect knowledge. Comparison of native and non-native listener performance in speech-in-noise tasks helps to clarify the role of prior l

  6. Intelligibility of native and non-native Dutch Speech

    NARCIS (Netherlands)

    Wijngaarden, S.J. van

    2001-01-01

    The intelligibility of speech is known to be lower if the speaker is non-native instead of native for the given language. This study is aimed at quantifying the overall degradation due to limitations of non-native speakers of Dutch, specifically of Dutch-speaking Americans who have lived in the Neth

  7. Speech intelligibility of native and non-native speech

    NARCIS (Netherlands)

    Wijngaarden, S.J. van

    1999-01-01

    The intelligibility of speech is known to be lower if the talker is non-native instead of native for the given language. This study is aimed at quantifying the overall degradation due to acoustic-phonetic limitations of non-native talkers of Dutch, specifically of Dutch-speaking Americans who have l

  8. Preparing Non-Native English-Speaking ESL Teachers

    Science.gov (United States)

    Shin, Sarah J.

    2008-01-01

    This article addresses the challenges that non-native English-speaking teacher trainees face as they begin teaching English as a Second Language (ESL) in Western, English-speaking countries. Despite a great deal of training, non-native speaker teachers may be viewed as inadequate language teachers because they often lack native speaker competence…

  9. When the Teacher Is a Non-native Speaker

    Institute of Scientific and Technical Information of China (English)

    Pèter Medgyes

    2005-01-01

    @@ In "When the Teacher is a Non-native Speaker," Medgyes examines the differences in teaching behavior between native and non-native teachers of English, and then specifies the causes of those differences. The aim of the discussion is to raise the awareness of both groups of teachers to their respective strengths and weaknesses, and thus help them become better teachers.

  10. The Non-Native English Speaker Teachers in TESOL Movement

    Science.gov (United States)

    Kamhi-Stein, Lía D.

    2016-01-01

    It has been almost 20 years since what is known as the non-native English-speaking (NNES) professionals' movement--designed to increase the status of NNES professionals--started within the US-based TESOL International Association. However, still missing from the literature is an understanding of what a movement is, and why non-native English…

  11. Speech Recognition of Non-Native Speech Using Native and Non-Native Acoustic Models

    Science.gov (United States)

    2000-08-01

    NATIVE AND NON-NATIVE ACOUSTIC MODELS David A. van Leeuwen and Rosemary Orr vanLeeuwentm .tno. nl R. 0rr~kno. azn. nl TNO Human Factors Research...a] is pronounced closer to the [c] by the vowels . Journal of Phonetics, 25:437-470, 1997. 32 [2] D. B. Paul and J. M. Baker. The design for [9] R. H...J. Kershaw, [12] Tony Robinson. Private Communication. L. Lamel, D. A. van Leeuwen , D. Pye, A. J. Robinson, H. J. M. Steeneken, and P. C. Wood- [13

  12. Native and Non-Native Perceptions on a Non-Native Oral Discourse in an Academic Setting

    Directory of Open Access Journals (Sweden)

    Kenan Dikilitaş

    2012-07-01

    Full Text Available This qualitative study investigates discourse-level patterns typically employed by a Turkish lecturer based on the syntactic patterns found in the collected data. More specifically, the study aims to reveal how different native and non-native speakers of English perceive discourse patterns used by a non-native lecturer teaching in English. The data gathered from a Turkish lecturer teaching finance, and the interviews both with the lecturer and the students. The lecturer and the students were videotaped and the data was evaluated by content analysis. The results revealed a difference between the way non-native and native speakers evaluate an oral discourse of a non-native lecturer teaching in English. Native speakers of English found the oral performance moderately comprehensible, while non-native speakers found it relatively comprehensible.

  13. The Attitudes and Perceptions of Non-Native English Speaking ...

    African Journals Online (AJOL)

    The Attitudes and Perceptions of Non-Native English Speaking Adults toward Explicit Grammar Instruction. ... to excel in their academic careers, obtain good jobs, and interact well with those who speak English. ... AJOL African Journals Online.

  14. Perceptual assimilation and discrimination of non-native vowel contrasts

    Science.gov (United States)

    Tyler, Michael D.; Best, Catherine T.; Faber, Alice; Levitt, Andrea G.

    2014-01-01

    Research on language-specific tuning in speech perception has focused mainly on consonants, while that on non-native vowel perception has failed to address whether the same principles apply. Therefore, non-native vowel perception was investigated here in light of relevant theoretical models: The Perceptual Assimilation Model (PAM) and the Natural Referent Vowel (NRV) framework. American-English speakers completed discrimination and L1-assimilation (categorization and goodness rating) tests on six non-native vowel contrasts. Discrimination was consistent with PAM assimilation types, but asymmetries predicted by NRV were only observed for single-category assimilations, suggesting that perceptual assimilation might modulate the effects of vowel peripherality on non-native vowel perception. PMID:24923313

  15. Small mammal use of native warm-season and non-native cool-season grass forage fields

    Science.gov (United States)

    Ryan L Klimstra,; Christopher E Moorman,; Converse, Sarah J.; Royle, J. Andrew; Craig A Harper,

    2015-01-01

    Recent emphasis has been put on establishing native warm-season grasses for forage production because it is thought native warm-season grasses provide higher quality wildlife habitat than do non-native cool-season grasses. However, it is not clear whether native warm-season grass fields provide better resources for small mammals than currently are available in non-native cool-season grass forage production fields. We developed a hierarchical spatially explicit capture-recapture model to compare abundance of hispid cotton rats (Sigmodon hispidus), white-footed mice (Peromyscus leucopus), and house mice (Mus musculus) among 4 hayed non-native cool-season grass fields, 4 hayed native warm-season grass fields, and 4 native warm-season grass-forb ("wildlife") fields managed for wildlife during 2 summer trapping periods in 2009 and 2010 of the western piedmont of North Carolina, USA. Cotton rat abundance estimates were greater in wildlife fields than in native warm-season grass and non-native cool-season grass fields and greater in native warm-season grass fields than in non-native cool-season grass fields. Abundances of white-footed mouse and house mouse populations were lower in wildlife fields than in native warm-season grass and non-native cool-season grass fields, but the abundances were not different between the native warm-season grass and non-native cool-season grass fields. Lack of cover following haying in non-native cool-season grass and native warm-season grass fields likely was the key factor limiting small mammal abundance, especially cotton rats, in forage fields. Retention of vegetation structure in managed forage production systems, either by alternately resting cool-season and warm-season grass forage fields or by leaving unharvested field borders, should provide refugia for small mammals during haying events.

  16. Perceptual assimilation and discrimination of non-native vowel contrasts

    OpenAIRE

    2014-01-01

    Research on language-specific tuning in speech perception has focused mainly on consonants, while that on non-native vowel perception has failed to address whether the same principles apply. Therefore, non-native vowel perception was investigated here in light of relevant theoretical models: The Perceptual Assimilation Model (PAM) and the Natural Referent Vowel (NRV) framework. American-English speakers completed discrimination and L1-assimilation (categorization and goodnes...

  17. The role of abstraction in non-native speech perception.

    Science.gov (United States)

    Pajak, Bozena; Levy, Roger

    2014-09-01

    The end-result of perceptual reorganization in infancy is currently viewed as a reconfigured perceptual space, "warped" around native-language phonetic categories, which then acts as a direct perceptual filter on any non-native sounds: naïve-listener discrimination of non-native-sounds is determined by their mapping onto native-language phonetic categories that are acoustically/articulatorily most similar. We report results that suggest another factor in non-native speech perception: some perceptual sensitivities cannot be attributed to listeners' warped perceptual space alone, but rather to enhanced general sensitivity along phonetic dimensions that the listeners' native language employs to distinguish between categories. Specifically, we show that the knowledge of a language with short and long vowel categories leads to enhanced discrimination of non-native consonant length contrasts. We argue that these results support a view of perceptual reorganization as the consequence of learners' hierarchical inductive inferences about the structure of the language's sound system: infants not only acquire the specific phonetic category inventory, but also draw higher-order generalizations over the set of those categories, such as the overall informativity of phonetic dimensions for sound categorization. Non-native sound perception is then also determined by sensitivities that emerge from these generalizations, rather than only by mappings of non-native sounds onto native-language phonetic categories.

  18. An invasion risk map for non-native aquatic macrophytes of the Iberian Peninsula

    Directory of Open Access Journals (Sweden)

    Argantonio Rodríguez-Merino

    2017-05-01

    Full Text Available Freshwater systems are particularly susceptible to non-native organisms, owing to their high sensitivity to the impacts that are caused by these organisms. Species distribution models, which are based on both environmental and socio-economic variables, facilitate the identification of the most vulnerable areas for the spread of non-native species. We used MaxEnt to predict the potential distribution of 20 non-native aquatic macrophytes in the Iberian Peninsula. Some selected variables, such as the temperature seasonality and the precipitation in the driest quarter, highlight the importance of the climate on their distribution. Notably, the human influence in the territory appears as a key variable in the distribution of studied species. The model discriminated between favorable and unfavorable areas with high accuracy. We used the model to build an invasion risk map of aquatic macrophytes for the Iberian Peninsula that included results from 20 individual models. It showed that the most vulnerable areas are located near to the sea, the major rivers basins, and the high population density areas. These facts suggest the importance of the human impact on the colonization and distribution of non-native aquatic macrophytes in the Iberian Peninsula, and more precisely agricultural development during the Green Revolution at the end of the 70’s. Our work also emphasizes the utility of species distribution models for the prevention and management of biological invasions.

  19. Emotion and lying in a non-native language.

    Science.gov (United States)

    Caldwell-Harris, Catherine L; Ayçiçeği-Dinn, Ayşe

    2009-03-01

    Bilingual speakers frequently report experiencing greater emotional resonance in their first language compared to their second. In Experiment 1, Turkish university students who had learned English as a foreign language had reduced skin conductance responses (SCRs) when listening to emotional phrases in English compared to Turkish, an effect which was most pronounced for childhood reprimands. A second type of emotional language, reading out loud true and false statements, was studied in Experiment 2. Larger SCRs were elicited by lies compared to true statements, and larger SCRs were evoked by English statements compared to Turkish statements. In contrast, ratings of how strongly participants felt they were lying showed that Turkish lies were more strongly felt than English lies. Results suggest that two factors influence the electrodermal activity elicited when bilingual speakers lie in their two languages: arousal due to emotions associated with lying, and arousal due to anxiety about managing speech production in non-native language. Anxiety and emotionality when speaking a non-naive language need to be better understood to inform practices ranging from bilingual psychotherapy to police interrogation of suspects and witnesses.

  20. Gopherus agassizii (Desert Tortoise). Non-native seed dispersal

    Science.gov (United States)

    Ennen, J.R.; Loughran, Caleb L.; Lovich, Jeffrey E.

    2011-01-01

    Sahara Mustard (Brassica tournefortii) is a non-native, highly invasive weed species of southwestern U.S. deserts. Sahara Mustard is a hardy species, which flourishes under many conditions including drought and in both disturbed and undisturbed habitats (West and Nabhan 2002. In B. Tellman [ed.], Invasive Plants: Their Occurrence and Possible Impact on the Central Gulf Coast of Sonora and the Midriff Islands in the Sea of Cortes, pp. 91–111. University of Arizona Press, Tucson). Because of this species’ ability to thrive in these habitats, B. tournefortii has been able to propagate throughout the southwestern United States establishing itself in the Mojave and Sonoran Deserts in Arizona, California, Nevada, and Utah. Unfortunately, naturally disturbed areas created by native species, such as the Desert Tortoise (Gopherus agassizii), within these deserts could have facilitated the propagation of B. tournefortii. (Lovich 1998. In R. G. Westbrooks [ed.], Invasive Plants, Changing the Landscape of America: Fact Book, p. 77. Federal Interagency Committee for the Management of Noxious and Exotic Weeds [FICMNEW], Washington, DC). However, Desert Tortoises have never been directly observed dispersing Sahara Mustard seeds. Here we present observations of two Desert Tortoises dispersing Sahara Mustard seeds at the interface between the Mojave and Sonoran deserts in California.

  1. Identification of coniferous woods

    Science.gov (United States)

    B. Francis Kukachka

    1960-01-01

    The identification of coniferous woods is generally regarded as being more difficult than for the hardwood species. This is due to the fact that conifers are more elemental in their structure and, as a consequence, the number of diagnostic features that may he employed is proportionately smaller. Instructions are given here in the sequential use of primary diagnostic...

  2. Engineering biofuel tolerance in non-native producing microorganisms.

    Science.gov (United States)

    Jin, Hu; Chen, Lei; Wang, Jiangxin; Zhang, Weiwen

    2014-01-01

    Large-scale production of renewable biofuels through microbiological processes has drawn significant attention in recent years, mostly due to the increasing concerns on the petroleum fuel shortages and the environmental consequences of the over-utilization of petroleum-based fuels. In addition to native biofuel-producing microbes that have been employed for biofuel production for decades, recent advances in metabolic engineering and synthetic biology have made it possible to produce biofuels in several non-native biofuel-producing microorganisms. Compared to native producers, these non-native systems carry the advantages of fast growth, simple nutrient requirements, readiness for genetic modifications, and even the capability to assimilate CO2 and solar energy, making them competitive alternative systems to further decrease the biofuel production cost. However, the tolerance of these non-native microorganisms to toxic biofuels is naturally low, which has restricted the potentials of their application for high-efficiency biofuel production. To address the issues, researches have been recently conducted to explore the biofuel tolerance mechanisms and to construct robust high-tolerance strains for non-native biofuel-producing microorganisms. In this review, we critically summarize the recent progress in this area, focusing on three popular non-native biofuel-producing systems, i.e. Escherichia coli, Lactobacillus and photosynthetic cyanobacteria.

  3. Perceptual assimilation and discrimination of non-native vowel contrasts.

    Science.gov (United States)

    Tyler, Michael D; Best, Catherine T; Faber, Alice; Levitt, Andrea G

    2014-01-01

    Research on language-specific tuning in speech perception has focused mainly on consonants, while that on non-native vowel perception has failed to address whether the same principles apply. Therefore, non-native vowel perception was investigated here in light of relevant theoretical models: the Perceptual Assimilation Model (PAM) and the Natural Referent Vowel (NRV) framework. American-English speakers completed discrimination and native language assimilation (categorization and goodness rating) tests on six nonnative vowel contrasts. Discrimination was consistent with PAM assimilation types, but asymmetries predicted by NRV were only observed for single-category assimilations, suggesting that perceptual assimilation might modulate the effects of vowel peripherality on non-native vowel perception.

  4. Are non-native plants perceived to be more risky? Factors influencing horticulturists' risk perceptions of ornamental plant species.

    Directory of Open Access Journals (Sweden)

    Franziska Humair

    Full Text Available Horticultural trade is recognized as an important vector in promoting the introduction and dispersal of harmful non-native plant species. Understanding horticulturists' perceptions of biotic invasions is therefore important for effective species risk management. We conducted a large-scale survey among horticulturists in Switzerland (N = 625 to reveal horticulturists' risk and benefit perceptions from ornamental plant species, their attitudes towards the regulation of non-native species, as well as the factors decisive for environmental risk perceptions and horticulturists' willingness to engage in risk mitigation behavior. Our results suggest that perceived familiarity with a plant species had a mitigating effect on risk perceptions, while perceptions of risk increased if a species was perceived to be non-native. However, perceptions of the non-native origin of ornamental plant species were often not congruent with scientific classifications. Horticulturists displayed positive attitudes towards mandatory trade regulations, particularly towards those targeted against known invasive species. Participants also expressed their willingness to engage in risk mitigation behavior. Yet, positive effects of risk perceptions on the willingness to engage in risk mitigation behavior were counteracted by perceptions of benefits from selling non-native ornamental species. Our results indicate that the prevalent practice in risk communication to emphasize the non-native origin of invasive species can be ineffective, especially in the case of species of high importance to local industries and people. This is because familiarity with these plants can reduce risk perceptions and be in conflict with scientific concepts of non-nativeness. In these cases, it might be more effective to focus communication on well-documented environmental impacts of harmful species.

  5. Evaluating ecosystem services provided by non-native species: an experimental test in California grasslands.

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    Claudia Stein

    Full Text Available The concept of ecosystem services--the benefits that nature provides to human's society--has gained increasing attention over the past decade. Increasing global abiotic and biotic change, including species invasions, is threatening the secure delivery of these ecosystem services. Efficient evaluation methods of ecosystem services are urgently needed to improve our ability to determine management strategies and restoration goals in face of these new emerging ecosystems. Considering a range of multiple ecosystem functions may be a useful way to determine such strategies. We tested this framework experimentally in California grasslands, where large shifts in species composition have occurred since the late 1700's. We compared a suite of ecosystem functions within one historic native and two non-native species assemblages under different grazing intensities to address how different species assemblages vary in provisioning, regulatory and supporting ecosystem services. Forage production was reduced in one non-native assemblage (medusahead. Cultural ecosystem services, such as native species diversity, were inherently lower in both non-native assemblages, whereas most other services were maintained across grazing intensities. All systems provided similar ecosystem services under the highest grazing intensity treatment, which simulated unsustainable grazing intensity. We suggest that applying a more comprehensive ecosystem framework that considers multiple ecosystem services to evaluate new emerging ecosystems is a valuable tool to determine management goals and how to intervene in a changing ecosystem.

  6. Economic impacts of non-native forest insects in the continental United States.

    Directory of Open Access Journals (Sweden)

    Juliann E Aukema

    Full Text Available Reliable estimates of the impacts and costs of biological invasions are critical to developing credible management, trade and regulatory policies. Worldwide, forests and urban trees provide important ecosystem services as well as economic and social benefits, but are threatened by non-native insects. More than 450 non-native forest insects are established in the United States but estimates of broad-scale economic impacts associated with these species are largely unavailable. We developed a novel modeling approach that maximizes the use of available data, accounts for multiple sources of uncertainty, and provides cost estimates for three major feeding guilds of non-native forest insects. For each guild, we calculated the economic damages for five cost categories and we estimated the probability of future introductions of damaging pests. We found that costs are largely borne by homeowners and municipal governments. Wood- and phloem-boring insects are anticipated to cause the largest economic impacts by annually inducing nearly $1.7 billion in local government expenditures and approximately $830 million in lost residential property values. Given observations of new species, there is a 32% chance that another highly destructive borer species will invade the U.S. in the next 10 years. Our damage estimates provide a crucial but previously missing component of cost-benefit analyses to evaluate policies and management options intended to reduce species introductions. The modeling approach we developed is highly flexible and could be similarly employed to estimate damages in other countries or natural resource sectors.

  7. Evaluating ecosystem services provided by non-native species: an experimental test in California grasslands.

    Science.gov (United States)

    Stein, Claudia; Hallett, Lauren M; Harpole, W Stanley; Suding, Katharine N

    2014-01-01

    The concept of ecosystem services--the benefits that nature provides to human's society--has gained increasing attention over the past decade. Increasing global abiotic and biotic change, including species invasions, is threatening the secure delivery of these ecosystem services. Efficient evaluation methods of ecosystem services are urgently needed to improve our ability to determine management strategies and restoration goals in face of these new emerging ecosystems. Considering a range of multiple ecosystem functions may be a useful way to determine such strategies. We tested this framework experimentally in California grasslands, where large shifts in species composition have occurred since the late 1700's. We compared a suite of ecosystem functions within one historic native and two non-native species assemblages under different grazing intensities to address how different species assemblages vary in provisioning, regulatory and supporting ecosystem services. Forage production was reduced in one non-native assemblage (medusahead). Cultural ecosystem services, such as native species diversity, were inherently lower in both non-native assemblages, whereas most other services were maintained across grazing intensities. All systems provided similar ecosystem services under the highest grazing intensity treatment, which simulated unsustainable grazing intensity. We suggest that applying a more comprehensive ecosystem framework that considers multiple ecosystem services to evaluate new emerging ecosystems is a valuable tool to determine management goals and how to intervene in a changing ecosystem.

  8. Initial Teacher Training Courses and Non-Native Speaker Teachers

    Science.gov (United States)

    Anderson, Jason

    2016-01-01

    This article reports on a study contrasting 41 native speakers (NSs) and 38 non-native speakers (NNSs) of English from two short initial teacher training courses, the Cambridge Certificate in English Language Teaching to Adults and the Trinity College London CertTESOL. After a brief history and literature review, I present findings on teachers'…

  9. Initial Teacher Training Courses and Non-Native Speaker Teachers

    Science.gov (United States)

    Anderson, Jason

    2016-01-01

    This article reports on a study contrasting 41 native speakers (NSs) and 38 non-native speakers (NNSs) of English from two short initial teacher training courses, the Cambridge Certificate in English Language Teaching to Adults and the Trinity College London CertTESOL. After a brief history and literature review, I present findings on teachers'…

  10. The Ceremonial Elements of Non-Native Cultures.

    Science.gov (United States)

    Horwood, Bert

    1994-01-01

    Explores reasons behind the wrongful adoption of Native American ceremonies by Euro-Americans. Focuses on the need for ceremony, its relevance to environmental education, and the fact that some immigrant cultural traditions neither fit this new land nor value the earth. Suggests how non-Natives can express their connection to the land by creating…

  11. Non-Native University Students' Perception of Plagiarism

    Science.gov (United States)

    Ahmad, Ummul Khair; Mansourizadeh, Kobra; Ai, Grace Koh Ming

    2012-01-01

    Plagiarism is a complex issue especially among non-native students and it has received a lot of attention from researchers and scholars of academic writing. Some scholars attribute this problem to cultural perceptions and different attitudes toward texts. This study evaluates student perception of different aspects of plagiarism. A small group of…

  12. Native Speakers' Perception of Non-Native English Speech

    Science.gov (United States)

    Jaber, Maysa; Hussein, Riyad F.

    2011-01-01

    This study is aimed at investigating the rating and intelligibility of different non-native varieties of English, namely French English, Japanese English and Jordanian English by native English speakers and their attitudes towards these foreign accents. To achieve the goals of this study, the researchers used a web-based questionnaire which…

  13. Empowering Non-Native English Speaking Teachers through Critical Pedagogy

    Science.gov (United States)

    Hayati, Nur

    2010-01-01

    Critical pedagogy is a teaching approach that aims to develop students' critical thinking, political and social awareness, and self esteem through dialogue learning and reflection. Related to the teaching of EFL, this pedagogy holds the potential to empower non native English speaking teachers (NNESTs) when incorporated into English teacher…

  14. Seasonal greenhouse gas and soil nutrient cycling in semi-arid native and non-native perennial grass pastures

    Science.gov (United States)

    Previous research indicates that a difference occurs in native and non-native grass species in regard to drivers of greenhouse gas (GHG, (carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O))) emissions from soil. Drivers of soil nutrients could help establish best management practices to mit...

  15. Assessment of local management practices on the population ecology of some medicinal plants in the coniferous forest of Northern Parts of Pakistan.

    Science.gov (United States)

    Sher, Hassan; Elyemeni, Mohammad; Khan, Abdur Rehman; Sabir, Amjad

    2011-04-01

    A study on the assessment of local management practices on the population of three medicinal plants viz.: Persicaria amplexicaule. D. Don., Valeriana jatamansi Jones and Viola serpens Wall ex Roxb was conducted during 2002-2004 in the coniferous forest of Northern Parts of Pakistan. The objective of the study was to know the impact of current management practices on the population size of targeted plants. The study showed that the involvement of locals in the gathering of targeted plants varied with the change in elevation. Among the targeted plants V. serpens was collected by large majorities of people (83.3%) at 2700 m followed by 72% at 2300 m and 37% at 1900 m. V. jatamansi was harvested by a small number of people (18.1%) at 1900 and 2300 m each, followed by 8.3% at 2700 m. While P. amplexicaule was harvested by a few collectors (9.1%) at 1900 m and 9.6% at 2300 m followed by 8.3% at 2700 m. The study concluded that these species have been extracted so heavily in the past that they are found now sparsely in some sites of the study area. Secondly, due to loss of its habitat by deforestation and encroachment of land for cultivation its population is on the decline towards extinction. Therefore, the current study recommends the conservation of the remaining populations of targeted plants through active participation of local communities.

  16. The intelligibility of Lombard speech for non-native listeners.

    Science.gov (United States)

    Cooke, Martin; Lecumberri, Maria Luisa García

    2012-08-01

    Speech produced in the presence of noise--Lombard speech--is more intelligible in noise than speech produced in quiet, but the origin of this advantage is poorly understood. Some of the benefit appears to arise from auditory factors such as energetic masking release, but a role for linguistic enhancements similar to those exhibited in clear speech is possible. The current study examined the effect of Lombard speech in noise and in quiet for Spanish learners of English. Non-native listeners showed a substantial benefit of Lombard speech in noise, although not quite as large as that displayed by native listeners tested on the same task in an earlier study [Lu and Cooke (2008), J. Acoust. Soc. Am. 124, 3261-3275]. The difference between the two groups is unlikely to be due to energetic masking. However, Lombard speech was less intelligible in quiet for non-native listeners than normal speech. The relatively small difference in Lombard benefit in noise for native and non-native listeners, along with the absence of Lombard benefit in quiet, suggests that any contribution of linguistic enhancements in the Lombard benefit for natives is small.

  17. Drivers of Non-Native Aquatic Species Invasions across the ...

    Science.gov (United States)

    Background/Question/Methods Mapping the geographic distribution of non-native aquatic species is a critically important precursor to understanding the anthropogenic and environmental factors that drive freshwater biological invasions. Such efforts are often limited to local scales and/or to a single taxa, missing the opportunity to observe and understand the drivers of macroscale invasion patterns at sub-continental or continental scales. Here we map the distribution of exotic freshwater species richness across the continental United States using publicly accessible species occurrence data (e.g GBIF) and investigate the role of human activity in driving macroscale patterns of aquatic invasion. Using a dasymetric model of human population density and a spatially explicit model of recreational freshwater fishing demand, we analyzed the effect of these metrics of human influence on non-native aquatic species richness at the watershed scale, while controlling for spatial and sampling bias. We also assessed the effects that a temporal mismatch between occurrence data (collected since 1815) and cross-sectional predictors (developed using 2010 data) may have on model fit. Results/Conclusions Our results indicated that non-native aquatic species richness exhibits a highly patchy distribution, with hotspots in the Northeast, Great Lakes, Florida, and human population centers on the Pacific coast. These richness patterns are correlated with population density, but are m

  18. Risk assessment of non-native fishes in the Balkans Region using FISK, the invasiveness screening tool for non-native freshwater fishes

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    P. SIMONOVIC

    2013-06-01

    Full Text Available A high level of freshwater fish endemism in the Balkans Region emphasizes the need for non-native species risk assessments to inform management and control measures, with pre-screening tools, such as the Fish Invasiveness Screening Kit (FISK providing a useful first step. Applied to 43 non-native and translocated freshwater fishes in four Balkan countries, FISK reliably discriminated between invasive and non-invasive species, with a calibration threshold value of 9.5 distinguishing between species of medium and high risk sensu lato of becoming invasive. Twelve of the 43 species were assessed by scientists from two or more Balkan countries, and the remaining 31 species by a single assessor. Using the 9.5 threshold, three species were classed as low risk, 10 as medium risk, and 30 as high risk, with the latter category comprised of 26 moderately high risk, three high risk, and one very high risk species. Confidence levels in the assessments were relatively constant for all species, indicating concordance amongst assessors.

  19. Locking horns with Hawai‘i’s non-native ungulate issues

    Science.gov (United States)

    Hess, Steve

    2014-01-01

    Conservation and management interests for sustained-yield hunting of non-native ungulates in Hawai‘i have conflicted with the conservation of native biota for several decades. Hawaiian ecosystems evolved in the absence of large mammals and all currently hunted animals in Hawai‘i are non-native species. The best-studied aspects of Hawai‘i’s ungulates have dealt primarily with direct negative effects on native biota in natural areas, but there has been little research in population dynamics for sustained-yield management. Ungulates have been removed from approximately 750 km2 throughout the Hawaiian Islands to protect these natural areas, thereby reducing the amount of land area available for hunting activities and the maintenance of game populations. At the same time, unauthorized introductions of additional wild ungulate species between Hawaiian Islands have recently increased in frequency. The majority of hunting activities are of feral domestic livestock species for subsistence purposes, which typically do not generate sufficient revenue to offset costs of game management. Moreover, bag limits and seasons are generally not determined from biological criteria because harvest reporting is voluntary and game populations are rarely monitored. Consequently, ungulate populations cannot be managed for any particular level of abundance or other objectives. Research and monitoring which emphasize population dynamics and productivity would enable more precisely regulated sustained-yield game management programs and may reduce potential conflicts with the conservation of native biota.

  20. NIS occurrence - Non-native species impacts on threatened and endangered salmonids

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The objectives of this project: a) Identify the distribution of non-natives in the Columbia River Basin b) Highlight the impacts of non-natives on salmonids c)...

  1. Warming climate may negatively affect native forest understory plant richness and composition by increasing invasions of non-native plants

    Science.gov (United States)

    Dovciak, M.; Wason, J. W., III; Frair, J.; Lesser, M.; Hurst, J.

    2016-12-01

    Warming climate is often expected to cause poleward and upslope migrations of native plant species and facilitate the spread of non-native plants, and thus affect the composition and diversity of forest understory plant communities. However, changing climate can often interact with other components of global environmental change, and especially so with land use, which often varies along extant climatic gradients making it more difficult to predict species and biodiversity responses to changing climate. We used large national databases (USDA FIA, NLCD, and PRISM) within GLM and NMDS analytical frameworks to study the effects of climate (temperature and precipitation), and land management (type, fragmentation, time since disturbance) on the diversity and composition of native and non-native plant species in forest understories across large geographical (environmental) gradients of the northeastern United States. We tested how non-native and native species diversity and composition responded to existing climate gradients and land-use drivers, and we approximated how changing climate may affect both native and non-native species composition and richness under different climate change scenarios (+1.5, 2, and 4.8 degrees C). Many understory forest plant communities already contain large proportions of non-native plants, particularly so in relatively warmer and drier areas, at lower elevations, and in areas with more substantial land-use histories. On the other hand, cooler and moister areas, higher elevations, and areas used predominantly for forestry or nature conservation (i.e., large contiguous forest cover) were characterized by a low proportion of non-native plant species in terms of both species cover and richness. In contrast to native plants, non-native plant richness was related positively to mean annual temperature and negatively to precipitation. Mountain areas appeared to serve as refugia for native forest understory species under the current climate, but

  2. Aquatic macroinvertebrate responses to native and non-native predators

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    Haddaway N. R.

    2014-01-01

    Full Text Available Non-native species can profoundly affect native ecosystems through trophic interactions with native species. Native prey may respond differently to non-native versus native predators since they lack prior experience. Here we investigate antipredator responses of two common freshwater macroinvertebrates, Gammarus pulex and Potamopyrgus jenkinsi, to olfactory cues from three predators; sympatric native fish (Gasterosteus aculeatus, sympatric native crayfish (Austropotamobius pallipes, and novel invasive crayfish (Pacifastacus leniusculus. G. pulex responded differently to fish and crayfish; showing enhanced locomotion in response to fish, but a preference for the dark over the light in response to the crayfish. P.jenkinsi showed increased vertical migration in response to all three predator cues relative to controls. These different responses to fish and crayfish are hypothesised to reflect the predators’ differing predation types; benthic for crayfish and pelagic for fish. However, we found no difference in response to native versus invasive crayfish, indicating that prey naiveté is unlikely to drive the impacts of invasive crayfish. The Predator Recognition Continuum Hypothesis proposes that benefits of generalisable predator recognition outweigh costs when predators are diverse. Generalised responses of prey as observed here will be adaptive in the presence of an invader, and may reduce novel predators’ potential impacts.

  3. The Role of Tourism and Recreation in the Spread of Non-Native Species: A Systematic Review and Meta-Analysis.

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    Lucy G Anderson

    Full Text Available Managing the pathways by which non-native species are introduced and spread is considered the most effective way of preventing species invasions. Tourism and outdoor recreation involve the frequent congregation of people, vehicles and vessels from geographically diverse areas. They are therefore perceived to be major pathways for the movement of non-native species, and ones that will become increasingly important with the continued growth of these sectors. However, a global assessment of the relationship between tourism activities and the introduction of non-native species-particularly in freshwater and marine environments-is lacking. We conducted a systematic review and meta-analysis to determine the impact of tourism and outdoor recreation on non-native species in terrestrial, marine and freshwater environments. Our results provide quantitative evidence that the abundance and richness of non-native species are significantly higher in sites where tourist activities take place than in control sites. The pattern was consistent across terrestrial, freshwater and marine environments; across a variety of vectors (e.g. horses, hikers, yachts; and across a range of taxonomic groups. These results highlight the need for widespread biosecurity interventions to prevent the inadvertent introduction of invasive non-native species (INNS as the tourism and outdoor recreation sectors grow.

  4. The Role of Tourism and Recreation in the Spread of Non-Native Species: A Systematic Review and Meta-Analysis.

    Science.gov (United States)

    Anderson, Lucy G; Rocliffe, Steve; Haddaway, Neal R; Dunn, Alison M

    2015-01-01

    Managing the pathways by which non-native species are introduced and spread is considered the most effective way of preventing species invasions. Tourism and outdoor recreation involve the frequent congregation of people, vehicles and vessels from geographically diverse areas. They are therefore perceived to be major pathways for the movement of non-native species, and ones that will become increasingly important with the continued growth of these sectors. However, a global assessment of the relationship between tourism activities and the introduction of non-native species-particularly in freshwater and marine environments-is lacking. We conducted a systematic review and meta-analysis to determine the impact of tourism and outdoor recreation on non-native species in terrestrial, marine and freshwater environments. Our results provide quantitative evidence that the abundance and richness of non-native species are significantly higher in sites where tourist activities take place than in control sites. The pattern was consistent across terrestrial, freshwater and marine environments; across a variety of vectors (e.g. horses, hikers, yachts); and across a range of taxonomic groups. These results highlight the need for widespread biosecurity interventions to prevent the inadvertent introduction of invasive non-native species (INNS) as the tourism and outdoor recreation sectors grow.

  5. Non-Native (Exotic Snake Envenomations in the U.S., 2005–2011

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    Brandon J. Warrick

    2014-09-01

    Full Text Available Non-native (exotic snakes are a problematic source of envenomation worldwide. This manuscript describes the current demographics, outcomes and challenges of non-native snakebites in the United States (U.S.. We performed a retrospective case series of the National Poison Data System (NPDS database between 2005 and 2011. There were 258 human exposures involving at least 61 unique exotic venomous species (average = 37 per year; range = 33–40. Males comprised 79% and females 21%. The average age was 33 years with 16% less than 20 years old. 70% of bites occurred in a private residence and 86% were treated at a healthcare facility. 35% of cases received antivenom and 10% were given antibiotics. This study is compared to our previous study (1994–2004 in which there was a substantial coding error rate. Software modifications significantly reduced coding errors. Identification and acquisition of appropriate antivenoms pose a number of logistical difficulties in the management of these envenomations. In the U.S., poison centers have valuable systems and clinical roles in the provision of expert consultation and in the management of these cases.

  6. Non-Native (Exotic) Snake Envenomations in the U.S., 2005–2011

    Science.gov (United States)

    Warrick, Brandon J.; Boyer, Leslie V.; Seifert, Steven A.

    2014-01-01

    Non-native (exotic) snakes are a problematic source of envenomation worldwide. This manuscript describes the current demographics, outcomes and challenges of non-native snakebites in the United States (U.S.). We performed a retrospective case series of the National Poison Data System (NPDS) database between 2005 and 2011. There were 258 human exposures involving at least 61 unique exotic venomous species (average = 37 per year; range = 33–40). Males comprised 79% and females 21%. The average age was 33 years with 16% less than 20 years old. 70% of bites occurred in a private residence and 86% were treated at a healthcare facility. 35% of cases received antivenom and 10% were given antibiotics. This study is compared to our previous study (1994–2004) in which there was a substantial coding error rate. Software modifications significantly reduced coding errors. Identification and acquisition of appropriate antivenoms pose a number of logistical difficulties in the management of these envenomations. In the U.S., poison centers have valuable systems and clinical roles in the provision of expert consultation and in the management of these cases. PMID:25268980

  7. EMPOWERING NON-NATIVE ENGLISH SPEAKING TEACHERS THROUGH CRITICAL PEDAGOGY

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    Nur Hayati

    2010-02-01

    Full Text Available Critical pedagogy is a teaching approach that aims to develop students’ critical thinking, political and social awareness, and self esteem through dialogue learning and reflection. Related to the teaching of EFL, this pedagogy holds the potential to empower non native English speaking teachers (NNESTs when incorporated into English teacher education programs. It can help aspiring NNESTs to grow awareness of the political and sociocultural implications of EFL teaching, to foster their critical thinking on any concepts or ideas regarding their profession, and more importantly, to recognize their strengths as NNESTs. Despite the potential, the role of critical pedagogy in improving EFL teacher education program in Indonesia has not been sufficiently discussed. This article attempts to contribute to the discussion by looking at a number of ways critical pedagogy can be incorporated in the programs, the rationale for doing so, and the challenges that might come on the way.

  8. The non-native seaweed Asparagopsis armata supports a diverse crustacean assemblage.

    Science.gov (United States)

    Pacios, I; Guerra-García, J M; Baeza-Rojano, E; Cabezas, M P

    2011-05-01

    This is the first study describing the crustacean fauna associated to Asparagopsis armata, a non-native, red seaweed widely distributed along western Mediterranean coasts. First found in Australia and New Zealand, it was introduced naturally through the Strait of Gibraltar and rapidly spread out. A one-year spatio-temporal study (Feb 08-Feb 09) was carried out in the Strait of Gibraltar to characterize the spatio-temporal patterns of the associated crustacean fauna. Maximum biomass of A. armata was measured during April-June, whereas the maximum crustacean abundances were registered from June-October. In total 41 crustacean species were identified. The caprellid Caprella penantis, traditionally associated to non-polluted areas, was more abundant on Tarifa Island (higher values of dissolved oxygen and pH) than in Algeciras (lower oxygen and pH). The gammarid Podocerus variegatus was dominant in Algeciras Bay while Hyale schmidti and Apherusa mediterranea were the most abundant on Tarifa Island. Among isopods, Synisoma nadejda was only found on Tarifa Island. When compared with literature of native algae of the intertidal and shallow sublittoral, the species richness of associated crustaceans was similar in A. armata and the natives. Very little is known about the influence of this algae on altering marine communities, so complete faunistic studies dealing with other groups such as polychaetes or molluscs are necessary to properly address biogeographical, ecological and management programmes dealing with this non-native species. Copyright © 2011 Elsevier Ltd. All rights reserved.

  9. Exploring Non-Native EFL Teachers’ Knowledge Base: Practices and Perceptions

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    Anchalee Jansem

    2014-11-01

    Full Text Available This qualitative study was conducted to explore non-native EFL teachers’ knowledge base performed during instruction, perceived knowledge base underlying teaching practices, and perceived pathways of knowledge base construction.  The data from four sources including video recordings of classroom observations, interviews, detailed field-notes taken during classroom observations, and participants’ reflections revealed that the eight participants integrated knowledge of the English language, other content areas, instructional delivery, classroom management, and the changing world and social contexts in their instruction.  The findings indicated that the participants realized that their knowledge consisted of language construction and skills, other content areas, ability to teach, understanding students’ strengths, weaknesses, and needs, the changing world, social contexts, and technology, as well as problem solving ability.  Also, they perceived teacher education programs, additional learning experience, teaching experience, in-service professional development activities, and a working environment as key sources of knowledge base construction for non-native teachers. Keywords: knowledge base, English as a Foreign language teachers, knowledge construction

  10. Free classification of American English dialects by native and non-native listeners.

    Science.gov (United States)

    Clopper, Cynthia G; Bradlow, Ann R

    2009-10-01

    Most second language acquisition research focuses on linguistic structures, and less research has examined the acquisition of sociolinguistic patterns. The current study explored the perceptual classification of regional dialects of American English by native and non-native listeners using a free classification task. Results revealed similar classification strategies for the native and non-native listeners. However, the native listeners were more accurate overall than the non-native listeners. In addition, the non-native listeners were less able to make use of constellations of cues to accurately classify the talkers by dialect. However, the non-native listeners were able to attend to cues that were either phonologically or sociolinguistically relevant in their native language. These results suggest that non-native listeners can use information in the speech signal to classify talkers by regional dialect, but that their lack of signal-independent cultural knowledge about variation in the second language leads to less accurate classification performance.

  11. Impacts of fire on non-native plant recruitment in black spruce forests of interior Alaska

    Science.gov (United States)

    Conway, Alexandra J.; Jean, Mélanie

    2017-01-01

    Climate change is expected to increase the extent and severity of wildfires throughout the boreal forest. Historically, black spruce (Picea mariana (Mill.) B.S.P.) forests in interior Alaska have been relatively free of non-native species, but the compounding effects of climate change and an altered fire regime could facilitate the expansion of non-native plants. We tested the effects of wildfire on non-native plant colonization by conducting a seeding experiment of non-native plants on different substrate types in a burned black spruce forest, and surveying for non-native plants in recently burned and mature black spruce forests. We found few non-native plants in burned or mature forests, despite their high roadside presence, although invasion of some burned sites by dandelion (Taraxacum officinale) indicated the potential for non-native plants to move into burned forest. Experimental germination rates were significantly higher on mineral soil compared to organic soil, indicating that severe fires that combust much of the organic layer could increase the potential for non-native plant colonization. We conclude that fire disturbances that remove the organic layer could facilitate the invasion of non-native plants providing there is a viable seed source and dispersal vector. PMID:28158284

  12. Using the Speech Transmission Index to predict the intelligibility of non-native speech

    Science.gov (United States)

    van Wijngaarden, Sander J.; Steeneken, Herman J. M.; Houtgast, Tammo; Bronkhorst, Adelbert W.

    2002-05-01

    The calibration of the Speech Transmission Index (STI) is based on native speech, presented to native listeners. This means that the STI predicts speech intelligibility under the implicit assumption of fully native communication. In order to assess effects of both non-native production and non-native perception of speech, the intelligibility of short sentences was measured in various non-native scenarios, as a function of speech-to-noise ratio. Since each speech-to-noise ratio is associated with a unique STI value, this establishes the relation between sentence intelligibility and STI. The difference between native and non-native intelligibility as a function of STI was used to calculate a correction function for the STI for each separate non-native scenario. This correction function was applied to the STI ranges corresponding to certain intelligibility categories (bad-excellent). Depending on the proficiency of non-native talkers and listeners, the category boundaries were found to differ from the standard (native) boundaries by STI values up to 0.30 (on the standard 0-1 scale). The corrections needed for non-native listeners are greater than for non-native talkers with a similar level of proficiency. For some categories of non-native communicators, the qualification excellent requires an STI higher than 1.00, and therefore cannot be reached.

  13. Fire history of coniferous riparian forests in the Sierra Nevada

    Science.gov (United States)

    K. Van de Water; M. North

    2010-01-01

    Fire is an important ecological process in many western U.S. coniferous forests, yet high fuel loads, rural home construction and other factors have encouraged the suppression of most wildfires. Using mechanical thinning and prescribed burning, land managers often try to reduce fuels in strategic areas with the highest fuel loads. Riparian forests, however, are often...

  14. Native and Non-Native English Language Teachers

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    Ian Walkinshaw

    2014-05-01

    Full Text Available The English language teaching industry in East and Southeast Asia subscribes to an assumption that native English-speaking teachers (NESTs are the gold standard of spoken and written language, whereas non-native English-speaking teachers (non-NESTs are inferior educators because they lack this innate linguistic skill. But does this premise correspond with the views of second language learners? This article reports on research carried out with university students in Vietnam and Japan exploring the advantages and disadvantages of learning English from NESTs and non-NESTs. Contrary to the above notion, our research illuminated a number of perceived advantages—and disadvantages—in both types of teachers. Students viewed NESTs as models of pronunciation and correct language use, as well as being repositories of cultural knowledge, but they also found NESTs poor at explaining grammar, and their different cultures created tension. Non-NESTs were perceived as good teachers of grammar, and had the ability to resort to the students’ first language when necessary. Students found classroom interaction with non-NESTs easier because of their shared culture. Non-NESTs’ pronunciation was often deemed inferior to that of NESTs, but also easier to comprehend. Some respondents advocated learning from both types of teachers, depending on learners’ proficiency and the skill being taught.

  15. Effects of training on learning non-native speech contrasts

    Science.gov (United States)

    Sinnott, Joan M.

    2002-05-01

    An animal psychoacoustic procedure was used to train human listeners to categorize two non-native phonemic distinctions. In Exp 1, Japanese perception of the English liquid contrast /r-l/ was examined. In Exp 2, American-English perception of the Hindi dental-retroflex contrast /d-D/was examined. The training methods were identical in the two studies. The stimuli consisted of 64 CVs produced by four different native talkers (two male, two female) using four different vowels. The procedure involved manually moving a lever to make either a ``go-left'' or ``go-right'' response to categorize the stimuli. Feedback was given for correct and incorrect responses after each trial. After 32 training sessions, lasting about 8 weeks, performance was analyzed using both percent correct and response time as measures. Results showed that the Japanese listeners, as a group, were statistically similar to a group of native listeners in categorizing the liquid contrast. In contrast, the Amercan-English listeners were not nativelike in categorizing the dental-retroflex contrast. Hypotheses for the different results in the two experiments are discussed, including possible subject-related variables. In addition, the use of an animal model is proposed to objectively ``calibrate'' the psychoacoustic salience of various phoneme contrasts used in human speech.

  16. Applying the collective impact approach to address non-native species: A case study of the Great Lakes Phragmites Collaborative

    Science.gov (United States)

    Braun, H. B.; Kowalski, Kurt P.; Hollins, K.

    2016-01-01

    To address the invasion of non-native Phragmites in the Great Lakes, researchers at the U.S. Geological Survey—Great Lakes Science Center partnered with the Great Lakes Commission in 2012 to establish the Great Lakes Phragmites Collaborative (GLPC). The GLPC is a regional-scale partnership established to improve collaboration among stakeholders and increase the effectiveness of non-native Phragmites management and research. Rather than forming a traditional partnership with a narrowly defined goal, the GLPC follows the principles of collective impact to engage stakeholders, guide progress, and align resources to address this complex, regional challenge. In this paper, the concept and tenets of collective impact are described, the GLPC is offered as a model for other natural resource-focused collective impact efforts, and steps for establishing collaboratives are presented. Capitalizing on the interactive collective impact approach, the GLPC is moving toward a broadly accepted common agenda around which agencies and individuals will be able to better align their actions and generate measureable progress in the regional campaign to protect healthy, diverse ecosystems from damage caused by non-native Phragmites.

  17. Modern Greek Language: Acquisition of Morphology and Syntax by Non-Native Speakers

    Science.gov (United States)

    Andreou, Georgia; Karapetsas, Anargyros; Galantomos, Ioannis

    2008-01-01

    This study investigated the performance of native and non native speakers of Modern Greek language on morphology and syntax tasks. Non-native speakers of Greek whose native language was English, which is a language with strict word order and simple morphology, made more errors and answered more slowly than native speakers on morphology but not…

  18. Language Distance and Non-Native Syntactic Processing: Evidence from Event-Related Potentials

    Science.gov (United States)

    Zawiszewski, Adam; Gutierrez, Eva; Fernandez, Beatriz; Laka, Itziar

    2011-01-01

    In this study, we explore native and non-native syntactic processing, paying special attention to the language distance factor. To this end, we compared how native speakers of Basque and highly proficient non-native speakers of Basque who are native speakers of Spanish process certain core aspects of Basque syntax. Our results suggest that…

  19. Chinese Fantasy Novel: Empirical Study on New Word Teaching for Non-Native Learners

    Science.gov (United States)

    Meng, Bok Check; Soon, Goh Ying

    2014-01-01

    Giving additional learning materials such as Chinese fantasy novel to non-native learners can be strenuous. This study seeks to render empirical support on the usefulness of the use of new words in Chinese fantasy novel to enhance vocabulary learning among the non-native learners of Chinese. In general, the students agreed that they like to learn…

  20. The Impact of Non-Native English Teachers' Linguistic Insecurity on Learners' Productive Skills

    Science.gov (United States)

    Daftari, Giti Ehtesham; Tavil, Zekiye Müge

    2017-01-01

    The discrimination between native and non-native English speaking teachers is reported in favor of native speakers in literature. The present study examines the linguistic insecurity of non-native English speaking teachers (NNESTs) and investigates its influence on learners' productive skills by using SPSS software. The eighteen teachers…

  1. Determinants of success in native and non-native listening comprehension: an individual differences approach

    NARCIS (Netherlands)

    S. Andringa; N. Olsthoorn; C. van Beuningen; R. Schoonen; J. Hulstijn

    2012-01-01

    The goal of this study was to explain individual differences in both native and non-native listening comprehension; 121 native and 113 non-native speakers of Dutch were tested on various linguistic and nonlinguistic cognitive skills thought to underlie listening comprehension. Structural equation mo

  2. The Factors Influencing the Motivational Strategy Use of Non-Native English Teachers

    Science.gov (United States)

    Solak, Ekrem; Bayar, Adem

    2014-01-01

    Motivation can be considered one of the most important factors determining success in language classroom. Therefore, this research aims to determine the variables influencing the motivational strategies used by non-native English teachers in Turkish context. 122 non-native English teachers teaching English at a state-run university prep school…

  3. Cognitive and Emotional Evaluation of Two Educational Outdoor Programs Dealing with Non-Native Bird Species

    Science.gov (United States)

    Braun, Michael; Buyer, Regine; Randler, Christoph

    2010-01-01

    "Non-native organisms are a major threat to biodiversity". This statement is often made by biologists, but general conclusions cannot be drawn easily because of contradictory evidence. To introduce pupils aged 11-14 years to this topic, we employed an educational program dealing with non-native animals in Central Europe. The pupils took part in a…

  4. The effect of L1 orthography on non-native vowel perception

    NARCIS (Netherlands)

    Escudero, P.; Wanrooij, K.E.

    2010-01-01

    Previous research has shown that orthography influences the learning and processing of spoken non-native words. In this paper, we examine the effect of L1 orthography on non-native sound perception. In Experiment 1, 204 Spanish learners of Dutch and a control group of 20 native speakers of Dutch

  5. The Effect of L1 Orthography on Non-Native Vowel Perception

    Science.gov (United States)

    Escudero, Paola; Wanrooij, Karin

    2010-01-01

    Previous research has shown that orthography influences the learning and processing of spoken non-native words. In this paper, we examine the effect of L1 orthography on non-native sound perception. In Experiment 1, 204 Spanish learners of Dutch and a control group of 20 native speakers of Dutch were asked to classify Dutch vowel tokens by…

  6. Delayed Next Turn Repair Initiation in Native/Non-native Speaker English Conversation.

    Science.gov (United States)

    Wong, Jean

    2000-01-01

    Examines a form of other-initiated conversational repair that is delayed within next turn position, a form that is produced by non-native speakers of English whose native language is Mandarin. Using the framework of conversational analysis, shows that in native/non-native conversation, other-initiated repair is not always done as early as possible…

  7. Facing Innovation: Preparing Lecturers for English-Medium Instruction in a Non-Native Context.

    Science.gov (United States)

    Klaassen, R. G.; De Graaff, E.

    2001-01-01

    Discusses the effects of training on the teaching staff in an innovation process that is the implementation of English-medium instruction by non-native speaking lecturers to non-native speaking students. The workshop turned out to be the most appropriate professional development for the first two phases in the innovation process. (Contains 13…

  8. Cross-Linguistic Influence in Non-Native Languages: Explaining Lexical Transfer Using Language Production Models

    Science.gov (United States)

    Burton, Graham

    2013-01-01

    The focus of this research is on the nature of lexical cross-linguistic influence (CLI) between non-native languages. Using oral interviews with 157 L1 Italian high-school students studying English and German as non-native languages, the project investigated which kinds of lexis appear to be more susceptible to transfer from German to English and…

  9. Structural Correlates for Lexical Efficiency and Number of Languages in Non-Native Speakers of English

    Science.gov (United States)

    Grogan, A.; Parker Jones, O.; Ali, N.; Crinion, J.; Orabona, S.; Mechias, M. L.; Ramsden, S.; Green, D. W.; Price, C. J.

    2012-01-01

    We used structural magnetic resonance imaging (MRI) and voxel based morphometry (VBM) to investigate whether the efficiency of word processing in the non-native language (lexical efficiency) and the number of non-native languages spoken (2+ versus 1) were related to local differences in the brain structure of bilingual and multilingual speakers.…

  10. Cross-Linguistic Influence in Non-Native Languages: Explaining Lexical Transfer Using Language Production Models

    Science.gov (United States)

    Burton, Graham

    2013-01-01

    The focus of this research is on the nature of lexical cross-linguistic influence (CLI) between non-native languages. Using oral interviews with 157 L1 Italian high-school students studying English and German as non-native languages, the project investigated which kinds of lexis appear to be more susceptible to transfer from German to English and…

  11. Fire Regime along Latitudinal Gradients of Continuous to Discontinuous Coniferous Boreal Forests in Eastern Canada

    National Research Council Canada - National Science Library

    Portier, Jeanne; Gauthier, Sylvie; Leduc, Alain; Arseneault, Dominique; Bergeron, Yves

    2016-01-01

      Fire is the main disturbance in North American coniferous boreal forests. In Northern Quebec, Canada, where forest management is not allowed, the landscape is gradually constituted of more opened lichen woodlands...

  12. Discriminative Phoneme Sequences Extraction for Non-Native Speaker's Origin Classification

    CERN Document Server

    Bouselmi, Ghazi; Illina, Irina; Haton, Jean-Paul

    2007-01-01

    In this paper we present an automated method for the classification of the origin of non-native speakers. The origin of non-native speakers could be identified by a human listener based on the detection of typical pronunciations for each nationality. Thus we suppose the existence of several phoneme sequences that might allow the classification of the origin of non-native speakers. Our new method is based on the extraction of discriminative sequences of phonemes from a non-native English speech database. These sequences are used to construct a probabilistic classifier for the speakers' origin. The existence of discriminative phone sequences in non-native speech is a significant result of this work. The system that we have developed achieved a significant correct classification rate of 96.3% and a significant error reduction compared to some other tested techniques.

  13. Contrasting xylem vessel constraints on hydraulic conductivity between native and non-native woody understory species

    Directory of Open Access Journals (Sweden)

    Maria S Smith

    2013-11-01

    Full Text Available We examined the hydraulic properties of 82 native and non-native woody species common to forests of Eastern North America, including several congeneric groups, representing a range of anatomical wood types. We observed smaller conduit diameters with greater frequency in non-native species, corresponding to lower calculated potential vulnerability to cavitation index. Non-native species exhibited higher vessel-grouping in metaxylem compared with native species, however, solitary vessels were more prevalent in secondary xylem. Higher frequency of solitary vessels in secondary xylem was related to a lower potential vulnerability index. We found no relationship between anatomical characteristics of xylem, origin of species and hydraulic conductivity, indicating that non-native species did not exhibit advantageous hydraulic efficiency over native species. Our results confer anatomical advantages for non-native species under the potential for cavitation due to freezing, perhaps permitting extended growing seasons.

  14. Trophic Strategies of a Non-Native and a Native Amphibian Species in Shared Ponds.

    Directory of Open Access Journals (Sweden)

    Olatz San Sebastián

    Full Text Available One of the critical factors for understanding the establishment, success and potential impact on native species of an introduced species is a thorough knowledge of how these species manage trophic resources. Two main trophic strategies for resource acquisition have been described: competition and opportunism. In the present study our objective was to identify the main trophic strategies of the non-native amphibian Discoglossus pictus and its potential trophic impact on the native amphibian Bufo calamita. We determine whether D. pictus exploits similar trophic resources to those exploited by the native B. calamita (competition hypothesis or alternative resources (opportunistic hypothesis. To this end, we analyzed the stable isotope values of nitrogen and carbon in larvae of both species, in natural ponds and in controlled laboratory conditions. The similarity of the δ15N and δ13C values in the two species coupled with isotopic signal variation according to pond conditions and niche partitioning when they co-occurred indicated dietary competition. Additionally, the non-native species was located at higher levels of trophic niches than the native species and B. calamita suffered an increase in its standard ellipse area when it shared ponds with D. pictus. These results suggest niche displacement of B. calamita to non-preferred resources and greater competitive capacity of D. pictus in field conditions. Moreover, D. pictus showed a broader niche than the native species in all conditions, indicating increased capacity to exploit the diversity of resources; this may indirectly favor its invasiveness. Despite the limitations of this study (derived from potential variability in pond isotopic signals, the results support previous experimental studies. All the studies indicate that D. pictus competes with B. calamita for trophic resources with potential negative effects on the fitness of the latter.

  15. Diversity and significance of eriophyoid mites (Acari: Eriophyoidea associated with coniferous trees in Poland: a review

    Directory of Open Access Journals (Sweden)

    Kiedrowicz Agnieszka

    2016-06-01

    Full Text Available Among the approximately 200 eriophyoid mite species associated with coniferous trees worldwide, 33 species (of the families Eriophyidae and Phytoptidae infest conifers in Poland, and 24 of them can cause visible feeding symptoms. In this paper we discuss the importance of eriophyoid mites to coniferous plants in Poland and their potential impact on the decorative value of ornamental plants. We emphasize the general lack of knowledge about the diversity of eriophyoid mites associated with coniferous trees and its role in the management and control of this economically important mite group.

  16. How much does language proficiency by non-native listeners influence speech audiometric tests in noise?

    Science.gov (United States)

    Warzybok, Anna; Brand, Thomas; Wagener, Kirsten C; Kollmeier, Birger

    2015-01-01

    The current study investigates the extent to which the linguistic complexity of three commonly employed speech recognition tests and second language proficiency influence speech recognition thresholds (SRTs) in noise in non-native listeners. SRTs were measured for non-natives and natives using three German speech recognition tests: the digit triplet test (DTT), the Oldenburg sentence test (OLSA), and the Göttingen sentence test (GÖSA). Sixty-four non-native and eight native listeners participated. Non-natives can show native-like SRTs in noise only for the linguistically easy speech material (DTT). Furthermore, the limitation of phonemic-acoustical cues in digit triplets affects speech recognition to the same extent in non-natives and natives. For more complex and less familiar speech materials, non-natives, ranging from basic to advanced proficiency in German, require on average 3-dB better signal-to-noise ratio for the OLSA and 6-dB for the GÖSA to obtain 50% speech recognition compared to native listeners. In clinical audiology, SRT measurements with a closed-set speech test (i.e. DTT for screening or OLSA test for clinical purposes) should be used with non-native listeners rather than open-set speech tests (such as the GÖSA or HINT), especially if a closed-set version in the patient's own native language is available.

  17. Feedback in online course for non-native English-speaking students

    CERN Document Server

    Olesova, Larisa

    2013-01-01

    Feedback in Online Course for Non-Native English-Speaking Students is an investigation of the effectiveness of audio and text feedback provided in English in an online course for non-native English-speaking students. The study presents results showing how audio and text feedback can impact on non-native English-speaking students' higher-order learning as they participate in an asynchronous online course. It also discusses the results of how students perceive both types of the feedback provided. In addition, the study examines how the impact and perceptions differ when the instructor giving the

  18. 2011 Invasive Non-native Plant Inventory dataset : Quivira National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This dataset is a product of the 2011 invasive non-native plant inventory conducted at Quivira National Wildlife Refuge by Utah State University. This inventory...

  19. Recreational freshwater fishing drives non-native aquatic species richness patterns at a continental scale

    Data.gov (United States)

    U.S. Environmental Protection Agency — Aim. Mapping the geographic distribution of non-native aquatic species is a critically important precursor to understanding the anthropogenic and environmental...

  20. Non-native Chinese Foreign Language (CFL) Teachers: Identity and Discourse

    DEFF Research Database (Denmark)

    Zhang, Chun

    2014-01-01

    Abstract Native Chinese foreign language (CFL) teacher identity is an emerging subject of research interest in the teacher education. Yet, limited study has been done on the construction of Non-native CFL teachers in their home culture. Guided by a concept of teacher identity......-in-discourse, the paper reports on a qualitative study that explores how three Non-native CFL teachers construct their teacher identity as they interact with Danish students while teaching CFL at one Danish university. Data collected from in-depth interviews over a period of two years show that the Non-native CFL...... teachers face tensions and challenges in constructing their identities as CFL teachers, and the tensions and challenges that arose from Danish teaching culture could influence the Non-native CFL teachers' contributions to CFL teaching in their home cultures. The findings further show that in order to cope...

  1. Using the Speech Transmission Index for predicting non-native speech intelligibility

    Science.gov (United States)

    van Wijngaarden, Sander J.; Bronkhorst, Adelbert W.; Houtgast, Tammo; Steeneken, Herman J. M.

    2004-03-01

    While the Speech Transmission Index (STI) is widely applied for prediction of speech intelligibility in room acoustics and telecommunication engineering, it is unclear how to interpret STI values when non-native talkers or listeners are involved. Based on subjectively measured psychometric functions for sentence intelligibility in noise, for populations of native and non-native communicators, a correction function for the interpretation of the STI is derived. This function is applied to determine the appropriate STI ranges with qualification labels (``bad''-``excellent''), for specific populations of non-natives. The correction function is derived by relating the non-native psychometric function to the native psychometric function by a single parameter (ν). For listeners, the ν parameter is found to be highly correlated with linguistic entropy. It is shown that the proposed correction function is also valid for conditions featuring bandwidth limiting and reverberation.

  2. Turkish Students' Perspectives on Speaking Anxiety in Native and Non-Native English Speaker Classes

    Science.gov (United States)

    Bozavli, Ebubekir; Gulmez, Recep

    2012-01-01

    The aim of this study is to reveal the effect of FLA (foreign language anxiety) in native/non-native speaker of English classrooms. In this study, two groups of students (90 in total) of whom 38 were in NS (native speaker) class and 52 in NNS (non-native speaker) class taking English as a second language course for 22 hours a week at Erzincan…

  3. Spatial arrangement overrules environmental factors to structure native and non-native assemblages of synanthropic harvestmen.

    Directory of Open Access Journals (Sweden)

    Christoph Muster

    Full Text Available Understanding how space affects the occurrence of native and non-native species is essential for inferring processes that shape communities. However, studies considering spatial and environmental variables for the entire community - as well as for the native and non-native assemblages in a single study - are scarce for animals. Harvestmen communities in central Europe have undergone drastic turnovers during the past decades, with several newly immigrated species, and thus provide a unique system to study such questions. We studied the wall-dwelling harvestmen communities from 52 human settlements in Luxembourg and found the assemblages to be largely dominated by non-native species (64% of specimens. Community structure was analysed using Moran's eigenvector maps as spatial variables, and landcover variables at different radii (500 m, 1000 m, 2000 m in combination with climatic parameters as environmental variables. A surprisingly high portion of pure spatial variation (15.7% of total variance exceeded the environmental (10.6% and shared (4% components of variation, but we found only minor differences between native and non-native assemblages. This could result from the ecological flexibility of both, native and non-native harvestmen that are not restricted to urban habitats but also inhabit surrounding semi-natural landscapes. Nevertheless, urban landcover variables explained more variation in the non-native community, whereas coverage of semi-natural habitats (forests, rivers at broader radii better explained the native assemblage. This indicates that some urban characteristics apparently facilitate the establishment of non-native species. We found no evidence for competitive replacement of native by invasive species, but a community with novel combination of native and non-native species.

  4. An Analysis of Student Evaluations of Native and Non Native Korean Foreign Language Teachers

    Directory of Open Access Journals (Sweden)

    Julie Damron

    2009-08-01

    Full Text Available In an effort to analyze the strengths and weaknesses of native and non-native teaching assistants and part-time teachers (both referred to as TAs in this article, students completed 632 evaluations of Ko-rean Language TAs from 2005 to 2008, and these evaluations were compiled for an analysis of variants (ANOVA. The evaluations were categorized into three groups of TAs: native Korean-speaking female, native Korean-speaking male, and non-native male; non-native females would have been included in the study, but there were not enough non-native female teachers to have a reliable sample. In an effort to encourage more self-examined teaching practices, this study addresses the greatest strengths and weaknesses of each group. Results revealed several significant differences between the ratings of the groups: native female TAs rated lowest overall, and non-native male TAs rated highest overall. The most prominent differences be-tween groups occurred in ratings of amount students learned, TAs’ preparedness, TAs’ active involvement in students’ learning, TAs’ enthusiasm, and TAs’ tardiness. This study reviews students’ written comments on the evaluations and proposes possible causes of these findings, concluding that differences in ratings are based on both teaching patterns associated with each group of TAs and student re-sponse bias that favors non-native male speakers. Teaching patterns include a tendency for native (Korean female TAs to teach using a lecture format and non-native male TAs to teach using a discussion format; for native TAs to have difficulty adapting to the language level of the students; and for a more visible enthusiasm for Korean culture held by non-native TAs. Causes for bias may include “other-ing” females and natives, TA selection procedures, and trends in evaluating TAs based on language level.

  5. Trophic consequences of non-native pumpkinseed Lepomis gibbosus for native pond fishes

    OpenAIRE

    Copp, G. H.; Britton, J R; Guo, Z.; Edmonds-Brown, V; Pegg, Josie; L. VILIZZI; Davison, P.

    2017-01-01

    Introduced non-native fishes can cause considerable adverse impacts on freshwater ecosystems. The pumpkinseed Lepomis gibbosus, a North American centrarchid, is one of the most widely distributed non-native fishes in Europe, having established self-sustaining populations in at least 28 countries, including the U.K. where it is predicted to become invasive under warmer climate conditions. To predict the consequences of increased invasiveness, a field experiment was completed over a summer peri...

  6. Comprehending non-native speakers: theory and evidence for adjustment in manner of processing.

    Science.gov (United States)

    Lev-Ari, Shiri

    2014-01-01

    Non-native speakers have lower linguistic competence than native speakers, which renders their language less reliable in conveying their intentions. We suggest that expectations of lower competence lead listeners to adapt their manner of processing when they listen to non-native speakers. We propose that listeners use cognitive resources to adjust by increasing their reliance on top-down processes and extracting less information from the language of the non-native speaker. An eye-tracking study supports our proposal by showing that when following instructions by a non-native speaker, listeners make more contextually-induced interpretations. Those with relatively high working memory also increase their reliance on context to anticipate the speaker's upcoming reference, and are less likely to notice lexical errors in the non-native speech, indicating that they take less information from the speaker's language. These results contribute to our understanding of the flexibility in language processing and have implications for interactions between native and non-native speakers.

  7. The influence of non-native language proficiency on speech perception performance

    Directory of Open Access Journals (Sweden)

    Lisa eKilman

    2014-07-01

    Full Text Available The present study examined to what extent proficiency in a non-native language influences speech perception in noise. We explored how English proficiency affected native (Swedish and non-native (English speech perception in four speech reception threshold (SRT conditions including two energetic (stationary, fluctuating noise and two informational (two-talker babble Swedish, two-talker babble English maskers. Twenty-three normal-hearing native Swedish listeners participated, age between 28 and 64 years. The participants also performed standardized tests in English proficiency, non-verbal reasoning and working memory capacity. Our approach with focus on proficiency and the assessment of external as well as internal, listener-related factors allowed us to examine which variables explained intra-and interindividual differences in native and non-native speech perception performance. The main result was that in the non-native target, the level of English proficiency is a decisive factor for speech intelligibility in noise. High English proficiency improved performance in all four conditions when target language was English. The informational maskers were interfering more with perception than energetic maskers, specifically in the non-native language. The study also confirmed that the SRT's were better when target language was native compared to non-native.

  8. Northward invading non-native vascular plant species in and adjacent to Wood Buffalo National Park

    Energy Technology Data Exchange (ETDEWEB)

    Wein, R.W.; Wein, G.; Bahret, S.; Cody, W.J. (Alberta University, Edmonton, AB (Canada). Canadian Circumpolar Institute)

    A survey of the non-native vascular plant species in Wood Buffalo National Park, Canada's largest forested National Park, documented their presence and abundance in key locations. Most of the fifty-four species (nine new records) were found in disturbed sites including roadsides, settlements, farms, areas of altered hydrological regimes, recent bums, and intensive bison grazing. Species that have increased most in geographic area and abundance in recent years include [ital Agropyron repens], [ital Bromus inermis], [ital Chenopodium album], [ital Melilotus spp.], [ital Trifolium spp.], [ital Plantago major], [ital Achillea millefolium], [ital Crepis tectorum] and [ital Sonchus arvensis]. An additional 20 species, now common in the Peace River and Fort Vermilion areas, have the potential to invade the Park if plant communities are subjected to additional stress as northern climates are modified by the greenhouse effect and as other human-caused activities disturb the vegetation. It is recommended that permanent plots be located in key locations and monitored for species invasion and changing abundances as input to management plans.

  9. Non-native species in the vascular flora of highlands and mountains of Iceland

    Directory of Open Access Journals (Sweden)

    Pawel Wasowicz

    2016-01-01

    Full Text Available The highlands and mountains of Iceland are one of the largest remaining wilderness areas in Europe. This study aimed to provide comprehensive and up-to-date data on non-native plant species in these areas and to answer the following questions: (1 How many non-native vascular plant species inhabit highland and mountainous environments in Iceland? (2 Do temporal trends in the immigration of alien species to Iceland differ between highland and lowland areas? (3 Does the incidence of alien species in the disturbed and undisturbed areas within Icelandic highlands differ? (4 Does the spread of non-native species in Iceland proceed from lowlands to highlands? and (5 Can we detect hot-spots in the distribution of non-native taxa within the highlands? Overall, 16 non-native vascular plant species were detected, including 11 casuals and 5 naturalized taxa (1 invasive. Results showed that temporal trends in alien species immigration to highland and lowland areas are similar, but it is clear that the process of colonization of highland areas is still in its initial phase. Non-native plants tended to occur close to man-made infrastructure and buildings including huts, shelters, roads etc. Analysis of spatio-temporal patterns showed that the spread within highland areas is a second step in non-native plant colonization in Iceland. Several statically significant hot spots of alien plant occurrences were identified using the Getis-Ord Gi* statistic and these were linked to human disturbance. This research suggests that human-mediated dispersal is the main driving force increasing the risk of invasion in Iceland’s highlands and mountain areas.

  10. Non-native species in the vascular flora of highlands and mountains of Iceland.

    Science.gov (United States)

    Wasowicz, Pawel

    2016-01-01

    The highlands and mountains of Iceland are one of the largest remaining wilderness areas in Europe. This study aimed to provide comprehensive and up-to-date data on non-native plant species in these areas and to answer the following questions: (1) How many non-native vascular plant species inhabit highland and mountainous environments in Iceland? (2) Do temporal trends in the immigration of alien species to Iceland differ between highland and lowland areas? (3) Does the incidence of alien species in the disturbed and undisturbed areas within Icelandic highlands differ? (4) Does the spread of non-native species in Iceland proceed from lowlands to highlands? and (5) Can we detect hot-spots in the distribution of non-native taxa within the highlands? Overall, 16 non-native vascular plant species were detected, including 11 casuals and 5 naturalized taxa (1 invasive). Results showed that temporal trends in alien species immigration to highland and lowland areas are similar, but it is clear that the process of colonization of highland areas is still in its initial phase. Non-native plants tended to occur close to man-made infrastructure and buildings including huts, shelters, roads etc. Analysis of spatio-temporal patterns showed that the spread within highland areas is a second step in non-native plant colonization in Iceland. Several statically significant hot spots of alien plant occurrences were identified using the Getis-Ord Gi* statistic and these were linked to human disturbance. This research suggests that human-mediated dispersal is the main driving force increasing the risk of invasion in Iceland's highlands and mountain areas.

  11. Influence of native and non-native multitalker babble on speech recognition in noise

    Directory of Open Access Journals (Sweden)

    Chandni Jain

    2014-03-01

    Full Text Available The aim of the study was to assess speech recognition in noise using multitalker babble of native and non-native language at two different signal to noise ratios. The speech recognition in noise was assessed on 60 participants (18 to 30 years with normal hearing sensitivity, having Malayalam and Kannada as their native language. For this purpose, 6 and 10 multitalker babble were generated in Kannada and Malayalam language. Speech recognition was assessed for native listeners of both the languages in the presence of native and nonnative multitalker babble. Results showed that the speech recognition in noise was significantly higher for 0 dB signal to noise ratio (SNR compared to -3 dB SNR for both the languages. Performance of Kannada Listeners was significantly higher in the presence of native (Kannada babble compared to non-native babble (Malayalam. However, this was not same with the Malayalam listeners wherein they performed equally well with native (Malayalam as well as non-native babble (Kannada. The results of the present study highlight the importance of using native multitalker babble for Kannada listeners in lieu of non-native babble and, considering the importance of each SNR for estimating speech recognition in noise scores. Further research is needed to assess speech recognition in Malayalam listeners in the presence of other non-native backgrounds of various types.

  12. Unique structural modulation of a non-native substrate by cochaperone DnaJ.

    Science.gov (United States)

    Tiwari, Satyam; Kumar, Vignesh; Jayaraj, Gopal Gunanathan; Maiti, Souvik; Mapa, Koyeli

    2013-02-12

    The role of bacterial DnaJ protein as a cochaperone of DnaK is strongly appreciated. Although DnaJ unaccompanied by DnaK can bind unfolded as well as native substrate proteins, its role as an individual chaperone remains elusive. In this study, we demonstrate that DnaJ binds a model non-native substrate with a low nanomolar dissociation constant and, more importantly, modulates the structure of its non-native state. The structural modulation achieved by DnaJ is different compared to that achieved by the DnaK-DnaJ complex. The nature of structural modulation exerted by DnaJ is suggestive of a unique unfolding activity on the non-native substrate by the chaperone. Furthermore, we demonstrate that the zinc binding motif along with the C-terminal substrate binding domain of DnaJ is necessary and sufficient for binding and the subsequent binding-induced structural alterations of the non-native substrate. We hypothesize that this hitherto unknown structural alteration of non-native states by DnaJ might be important for its chaperoning activity by removing kinetic traps of the folding intermediates.

  13. Looking through phonological shape to lexical meaning: the bottleneck of non-native sign language processing.

    Science.gov (United States)

    Mayberry, R I; Fischer, S D

    1989-11-01

    In two studies, we find that native and non-native acquisition show different effects on sign language processing. Subjects were all born deaf and used sign language for interpersonal communication, but first acquired it at ages ranging from birth to 18. In the first study, deaf signers shadowed (simultaneously watched and reproduced) sign language narratives given in two dialects, American Sign Language (ASL) and Pidgin Sign English (PSE), in both good and poor viewing conditions. In the second study, deaf signers recalled and shadowed grammatical and ungrammatical ASL sentences. In comparison with non-native signers, natives were more accurate, comprehended better, and made different kinds of lexical changes; natives primarily changed signs in relation to sign meaning independent of the phonological characteristics of the stimulus. In contrast, non-native signers primarily changed signs in relation to the phonological characteristics of the stimulus independent of lexical and sentential meaning. Semantic lexical changes were positively correlated to processing accuracy and comprehension, whereas phonological lexical changes were negatively correlated. The effects of non-native acquisition were similar across variations in the sign dialect, viewing condition, and processing task. The results suggest that native signers process lexical structural automatically, such that they can attend to and remember lexical and sentential meaning. In contrast, non-native signers appear to allocate more attention to the task of identifying phonological shape such that they have less attention available for retrieval and memory of lexical meaning.

  14. Positive effects of non-native grasses on the growth of a native annual in a southern california ecosystem.

    Science.gov (United States)

    Pec, Gregory J; Carlton, Gary C

    2014-01-01

    Fire disturbance is considered a major factor in the promotion of non-native plant species. Non-native grasses are adapted to fire and can alter environmental conditions and reduce resource availability in native coastal sage scrub and chaparral communities of southern California. In these communities persistence of non-native grasses following fire can inhibit establishment and growth of woody species. This may allow certain native herbaceous species to colonize and persist beneath gaps in the canopy. A field manipulative experiment with control, litter, and bare ground treatments was used to examine the impact of non-native grasses on growth and establishment of a native herbaceous species, Cryptantha muricata. C. muricata seedling survival, growth, and reproduction were greatest in the control treatment where non-native grasses were present. C. muricata plants growing in the presence of non-native grasses produced more than twice the number of flowers and more than twice the reproductive biomass of plants growing in the treatments where non-native grasses were removed. Total biomass and number of fruits were also greater in the plants growing in the presence of non-native grasses. Total biomass and reproductive biomass was also greater in late germinants than early germinants growing in the presence of non-native grasses. This study suggests a potential positive effect of non-native grasses on the performance of a particular native annual in a southern California ecosystem.

  15. Positive Effects of Non-Native Grasses on the Growth of a Native Annual in a Southern California Ecosystem

    Science.gov (United States)

    Pec, Gregory J.; Carlton, Gary C.

    2014-01-01

    Fire disturbance is considered a major factor in the promotion of non-native plant species. Non-native grasses are adapted to fire and can alter environmental conditions and reduce resource availability in native coastal sage scrub and chaparral communities of southern California. In these communities persistence of non-native grasses following fire can inhibit establishment and growth of woody species. This may allow certain native herbaceous species to colonize and persist beneath gaps in the canopy. A field manipulative experiment with control, litter, and bare ground treatments was used to examine the impact of non-native grasses on growth and establishment of a native herbaceous species, Cryptantha muricata. C. muricata seedling survival, growth, and reproduction were greatest in the control treatment where non-native grasses were present. C. muricata plants growing in the presence of non-native grasses produced more than twice the number of flowers and more than twice the reproductive biomass of plants growing in the treatments where non-native grasses were removed. Total biomass and number of fruits were also greater in the plants growing in the presence of non-native grasses. Total biomass and reproductive biomass was also greater in late germinants than early germinants growing in the presence of non-native grasses. This study suggests a potential positive effect of non-native grasses on the performance of a particular native annual in a southern California ecosystem. PMID:25379790

  16. Drivers of the composition and diversity of carabid functional traits in UK coniferous plantations.

    Science.gov (United States)

    Spake, Rebecca; Barsoum, Nadia; Newton, Adrian C; Doncaster, C Patrick

    2016-01-01

    Functional diversity (FD) is increasingly used as a metric to evaluate the impact of forest management strategies on ecosystem functioning. Management interventions that aim to maximise FD require knowledge of multiple environmental drivers of FD, which have not been studied to date in temperate coniferous production forests. We quantified the relative importance of abiotic (forest management) and biotic (ground vegetation community) drivers of carabid FD and trait distribution in 44 coniferous plantation forest stands across the UK. Carabid FD declined with canopy cover and carabid body length correlated negatively with the percentage of open semi-natural area surrounding a plot. We conclude that forest management could enhance carabid FD through initiatives that emulate natural disturbance regimes through gap creation. We found that neither functional nor taxonomic metrics of vegetation diversity correlated with carabid FD, suggesting that restoration of plant communities, a major goal of forest restoration efforts, will not necessarily enhance carabid FD in coniferous plantations.

  17. Mountain coniferous forests, refugia and butterflies.

    Science.gov (United States)

    Varga, Zoltán

    2008-05-01

    The boreal coniferous forests form the most extended vegetation zone of the Northern Hemisphere. As opposed to North America, they are disconnected from the mountain coniferous forests in Europe, because of the dominant east-west direction of the mountain chains. Consequently, the mountain forests show some unique characteristic features of glacial survival and postglacial history, as well. The mountain coniferous forests have numerous common floral and faunal elements with the boreal zone. However, the few unique faunal elements of the European mountain coniferous forests can be used to unravel the peculiar patterns and processes of this biome. In this issue of Molecular Ecology, Thomas Schmitt and Karola Haubrich (2008) use the relatively common and taxonomically well-studied butterfly, the large ringlet (Erebia euryale) to identify the last glacial refugia and postglacial expansion routes.

  18. [Turpentined vapour baths with coniferous oil].

    Science.gov (United States)

    Raynal, Cécile

    2007-10-01

    This article presents the history of turpentined vapour baths used to treat rheumatismes. In the same time appeared patent medicines made with coniferous oil, sold by chemist near those baths establishments.

  19. Evidence for language transfer leading to a perceptual advantage for non-native listeners.

    Science.gov (United States)

    Chang, Charles B; Mishler, Alan

    2012-10-01

    Phonological transfer from the native language is a common problem for non-native speakers that has repeatedly been shown to result in perceptual deficits vis-à-vis native speakers. It was hypothesized, however, that transfer could help, rather than hurt, if it resulted in a beneficial bias. Due to differences in pronunciation norms between Korean and English, Koreans in the U.S. were predicted to be better than Americans at perceiving unreleased stops-not only in their native language (Korean) but also in their non-native language (English). In three experiments, Koreans were found to be significantly more accurate than Americans at identifying unreleased stops in Korean, at identifying unreleased stops in English, and at discriminating between the presence and absence of an unreleased stop in English. Taken together, these results suggest that cross-linguistic transfer is capable of boosting speech perception by non-natives beyond native levels.

  20. Epistemologies in the Text of Children's Books: Native- and non-Native-authored books

    Science.gov (United States)

    Dehghani, Morteza; Bang, Megan; Medin, Douglas; Marin, Ananda; Leddon, Erin; Waxman, Sandra

    2013-09-01

    An examination of artifacts provides insights into the goals, practices, and orientations of the persons and cultures who created them. Here, we analyze storybook texts, artifacts that are a part of many children's lives. We examine the stories in books targeted for 4-8-year-old children, contrasting the texts generated by Native American authors versus popular non-Native authors. We focus specifically on the implicit and explicit 'epistemological orientations' associated with relations between human beings and the rest of nature. Native authors were significantly more likely than non-Native authors to describe humans and the rest of nature as psychologically close and embedded in relationships. This pattern converges well with evidence from a behavioral task in which we probed Native (from urban inter-tribal and rural communities) and non-Native children's and adults' attention to ecological relations. We discuss the implications of these differences for environmental cognition and science learning.

  1. Diabetic retinopathy in native and non-native Sarawakians--findings from the Diabetic Eye Registry.

    Science.gov (United States)

    Mallika, P S; Aziz, S; Goh, P P; Lee, P Y; Cheah, W L; Chong, M S; Tan, A K

    2012-08-01

    This study aims to determine the risk factors associated with diabetic retinopathy (DR) among natives and non-natives Sarawakians who were seen at 3 public hospitals and one health clinic in Sarawak. It is a cross sectional study where data on patients with DM were collected by staff at these healthcare facilities and entered into the web-based Diabetic Eye Registry. Univariate and multivariate analysis was used to determine the association factors for DR. DR was significantly less associated with natives (24.4%) compared to non-native Sarawakians (34.1%) (p < 0.001). The odds of getting DR was higher in patients whose duration of DM was more than 20 years (OR = 2.6), who have renal impairment (OR = 1.7) and non-natives (OR = 1.4).

  2. Perceptual learning of non-native speech contrast and functioning of the olivocochlear bundle.

    Science.gov (United States)

    Kumar, Ajith U; Hegde, Medha; Mayaleela

    2010-07-01

    The purpose of this study was to investigate the relationship between perceptual learning of non-native speech sounds and strength of feedback in the medial olivocochlear bundle (MOCB). Discrimination abilities of non-native speech sounds (Malayalam) from its native counterparts (Hindi) were monitored during 12 days of training. Contralateral inhibition of otoacoustic emissions were measured on the first and twelfth day of training. Results suggested that training significantly improved reaction time and accuracy of identification of non-native speech sounds. There was a significant positive correlation between the slope (linear) of identification scores and change in distortion product otoacoustic emission inhibition at 3000 Hz. Findings suggest that during perceptual learning feedback from the MOCB may fine tune the brain stem and/or cochlea. However, such a change, isolated to a narrow frequency region, represents a limited effect and needs further exploration to confirm and/or extend any generalization of findings.

  3. Sleep and native language interference affect non-native speech sound learning.

    Science.gov (United States)

    Earle, F Sayako; Myers, Emily B

    2015-12-01

    Adults learning a new language are faced with a significant challenge: non-native speech sounds that are perceptually similar to sounds in one's native language can be very difficult to acquire. Sleep and native language interference, 2 factors that may help to explain this difficulty in acquisition, are addressed in 3 studies. Results of Experiment 1 showed that participants trained on a non-native contrast at night improved in discrimination 24 hr after training, while those trained in the morning showed no such improvement. Experiments 2 and 3 addressed the possibility that incidental exposure to perceptually similar native language speech sounds during the day interfered with maintenance in the morning group. Taken together, results show that the ultimate success of non-native speech sound learning depends not only on the similarity of learned sounds to the native language repertoire, but also to interference from native language sounds before sleep.

  4. Combined Acoustic and Pronunciation Modelling for Non-Native Speech Recognition

    CERN Document Server

    Bouselmi, Ghazi; Illina, Irina

    2007-01-01

    In this paper, we present several adaptation methods for non-native speech recognition. We have tested pronunciation modelling, MLLR and MAP non-native pronunciation adaptation and HMM models retraining on the HIWIRE foreign accented English speech database. The ``phonetic confusion'' scheme we have developed consists in associating to each spoken phone several sequences of confused phones. In our experiments, we have used different combinations of acoustic models representing the canonical and the foreign pronunciations: spoken and native models, models adapted to the non-native accent with MAP and MLLR. The joint use of pronunciation modelling and acoustic adaptation led to further improvements in recognition accuracy. The best combination of the above mentioned techniques resulted in a relative word error reduction ranging from 46% to 71%.

  5. Food sources of dominant macrozoobenthos between native and non-native mangrove forests: A comparative study

    Science.gov (United States)

    Chen, Luzhen; Yan, Ting; Xiong, Yiyi; Zhang, Yihui; Lin, Guanghui

    2017-03-01

    The macrozoobenthos is an important link of the food web in coastal wetlands. Diet-habitat relationships may significantly depend on qualitative differences and seasonal availability of food sources. Increasing interest has been shown in food web structure altered by non-native plants. In particular, however, a non-native mangrove species from Bangladesh, Sonneratia apetala, has been widely planted in China, but little is known about its possible impact on food sources of macrozoobenthos living in these non-native mangrove forests. Therefore, in this study, we used fatty acid analysis to compare the food sources of one littorinid snail and two grapsid crab species between two native mangrove forests and one non-native S. apetala plantation in the Zhanjiang Mangrove National Nature Reserve of China. We found that the sediment of all three forests had high diatom and bacteria signals, but low mangrove leaf signals, while the opposite patterns were detected in the three macrozoobenthos. Specifically, the gastropod Littoraria melanostoma relied mainly on mangrove leaves and brown algae as food sources, with significant differences among the three mangrove forests, and showed significant seasonal variation in its diet. The grapsidae species (Perisesarma bidens and Parasesarma plicatum) mainly grazed on mangrove litter, brown and green algae, and occasionally consumed diatoms and bacteria, also showing significant seasonal variation in their diet. Overall, Principle Components Analysis (PCA) of the fatty acid profiles showed a significant overlapping in food sources among the macrozoobenthos living in the non-native and native mangrove forests, but significant seasonal variations in their food sources. This suggests that the planting of non-native S. apetala near original mangrove forests has had little effect on the feeding behavior of macrozoobenthos some 10 years after planting.

  6. Fully Automated Non-Native Speech Recognition Using Confusion-Based Acoustic Model Integration

    OpenAIRE

    Bouselmi, Ghazi; Fohr, Dominique; Illina, Irina; Haton, Jean-Paul

    2005-01-01

    This paper presents a fully automated approach for the recognition of non-native speech based on acoustic model modification. For a native language (L1) and a spoken language (L2), pronunciation variants of the phones of L2 are automatically extracted from an existing non-native database as a confusion matrix with sequences of phones of L1. This is done using L1's and L2's ASR systems. This confusion concept deals with the problem of non existence of match between some L2 and L1 phones. The c...

  7. Global exchange and accumulation of non-native plants

    Science.gov (United States)

    van Kleunen, Mark; Dawson, Wayne; Essl, Franz; Pergl, Jan; Winter, Marten; Weber, Ewald; Kreft, Holger; Weigelt, Patrick; Kartesz, John; Nishino, Misako; Antonova, Liubov A.; Barcelona, Julie F.; Cabezas, Francisco J.; Cárdenas, Dairon; Cárdenas-Toro, Juliana; Castaño, Nicolás; Chacón, Eduardo; Chatelain, Cyrille; Ebel, Aleksandr L.; Figueiredo, Estrela; Fuentes, Nicol; Groom, Quentin J.; Henderson, Lesley; Inderjit; Kupriyanov, Andrey; Masciadri, Silvana; Meerman, Jan; Morozova, Olga; Moser, Dietmar; Nickrent, Daniel L.; Patzelt, Annette; Pelser, Pieter B.; Baptiste, María P.; Poopath, Manop; Schulze, Maria; Seebens, Hanno; Shu, Wen-Sheng; Thomas, Jacob; Velayos, Mauricio; Wieringa, Jan J.; Pyšek, Petr

    2015-09-01

    All around the globe, humans have greatly altered the abiotic and biotic environment with ever-increasing speed. One defining feature of the Anthropocene epoch is the erosion of biogeographical barriers by human-mediated dispersal of species into new regions, where they can naturalize and cause ecological, economic and social damage. So far, no comprehensive analysis of the global accumulation and exchange of alien plant species between continents has been performed, primarily because of a lack of data. Here we bridge this knowledge gap by using a unique global database on the occurrences of naturalized alien plant species in 481 mainland and 362 island regions. In total, 13,168 plant species, corresponding to 3.9% of the extant global vascular flora, or approximately the size of the native European flora, have become naturalized somewhere on the globe as a result of human activity. North America has accumulated the largest number of naturalized species, whereas the Pacific Islands show the fastest increase in species numbers with respect to their land area. Continents in the Northern Hemisphere have been the major donors of naturalized alien species to all other continents. Our results quantify for the first time the extent of plant naturalizations worldwide, and illustrate the urgent need for globally integrated efforts to control, manage and understand the spread of alien species.

  8. Non-Native Pre-Service English Teachers’ Narratives about Their Pronunciation Learning and Implications for Pronunciation Training

    OpenAIRE

    Chin Wen Chien

    2014-01-01

    This study analyzes 58 non-native pre-service elementary school English teachers’ narratives about their pronunciation learning and teaching. Two important findings emerge in this study.  First, participants did not have the same attitude toward their roles as non-native English speakers regarding pronunciation learning and teaching. Second, regardless of their attitude or roles as non-native English speakers, participants claimed that when they become language teachers in the future, they wi...

  9. Contrasting Pollinators and Pollination in Native and Non-Native Regions of Highbush Blueberry Production.

    Science.gov (United States)

    Gibbs, Jason; Elle, Elizabeth; Bobiwash, Kyle; Haapalainen, Tiia; Isaacs, Rufus

    2016-01-01

    Highbush blueberry yields are dependent on pollination by bees, and introduction of managed honey bees is the primary strategy used for pollination of this crop. Complementary pollination services are also provided by wild bees, yet highbush blueberry is increasingly grown in regions outside its native range where wild bee communities may be less adapted to the crop and growers may still be testing appropriate honey bee stocking densities. To contrast crop pollination in native and non-native production regions, we sampled commercial 'Bluecrop' blueberry fields in British Columbia and Michigan with grower-selected honey bee stocking rates (0-39.5 hives per ha) to compare bee visitors to blueberry flowers, pollination and yield deficits, and how those vary with local- and landscape-scale factors. Observed and Chao-1 estimated species richness, as well as Shannon diversity of wild bees visiting blueberries were significantly higher in Michigan where the crop is within its native range. The regional bee communities were also significantly different, with Michigan farms having greater dissimilarity than British Columbia. Blueberry fields in British Columbia had fewer visits by honey bees than those in Michigan, irrespective of stocking rate, and they also had lower berry weights and a significant pollination deficit. In British Columbia, pollination service increased with abundance of wild bumble bees, whereas in Michigan the abundance of honey bees was the primary predictor of pollination. The proportion of semi-natural habitat at local and landscape scales was positively correlated with wild bee abundance in both regions. Wild bee abundance declined significantly with distance from natural borders in Michigan, but not in British Columbia where large-bodied bumble bees dominated the wild bee community. Our results highlight the varying dependence of crop production on different types of bees and reveal that strategies for pollination improvement in the same crop can

  10. Carbon Costs of Constitutive and Expressed Resistance to a Non-Native Pathogen in Limber Pine

    Science.gov (United States)

    2016-01-01

    Increasing the frequency of resistance to the non-native fungus Cronartium ribicola (causative agent of white pine blister rust, WPBR) in limber pine populations is a primary management objective to sustain high-elevation forest communities. However, it is not known to what extent genetic disease resistance is costly to plant growth or carbon economy. In this study, we measured growth and leaf-level physiology in (1) seedling families from seed trees that have previously been inferred to carry or not carry Cr4, the dominant R gene allele conferring complete, gene-for-gene resistance to WPBR in limber pine, and (2) populations that were and were not infected with C. ribicola. We found that, in the absence of C. ribicola exposure, there was no significant difference in carbon relations between families born from seed trees that harbor the resistance allele compared to those that lack it, either to plant growth and phenology or leaf-level photosynthetic traits. However, post-infection with C. ribicola, growth was significantly reduced in inoculation survivors expressing complete resistance compared to uninoculated seedlings. Furthermore, inoculation survivors exhibited significant increases in a suite of traits including photosynthetic rate, respiration rate, leaf N, and stomatal conductance and a decrease in photosynthetic water-use efficiency. The lack of constitutive carbon costs associated with Cr4 resistance in non-stressed limber pine is consistent with a previous report that the R gene allele is not under selection in the absence of C. ribicola and suggests that host resistance may not bear a constitutive cost in pathosystems that have not coevolved. However, under challenge by C. ribicola, complete resistance to WPBR in limber pine has a significant cost to plant growth, though enhanced carbon acquisition post-infection may offset this somewhat. These costs and effects on performance further complicate predictions of this species’ response in warmer future

  11. Diet of non-native northern snakehead (Channa argus) compared to three co-occurring predators in the lower Potomac River, USA

    Science.gov (United States)

    Ryan K. Saylor,; Nicolas W.R. Laointe,; Angermeier, Paul

    2012-01-01

    Introductions of large, non-native, carnivorous fishes continue to occur worldwide and represent a substantial management concern to global biodiversity. One of the most recent non-native fishes to successfully establish in North America is the northern snakehead (Channa argus), found in the lower Potomac River catchment. Dispersal of the northern snakehead throughout this system has been well documented since its original discovery in May 2004; however, little is known about the foraging habits of this species and its interactions with co-occurring predators. Here, we quantify northern snakehead diet in comparison with the diets of naturalised largemouth bass (Micropterus salmoides), and native American eel (Anguilla rostrata) and yellow perch (Perca flavescens) collected from tidal freshwaters bordering Virginia and Maryland near Fort Belvoir, Virginia. Over 97% of northern snakehead gut contents were fishes, with fundulid and centrarchid species consumed most frequently. Dietary overlap was biologically significant only between northern snakehead and largemouth bass. Aquatic invertebrates were >10 times more common in native predator diets, reducing dietary overlap with northern snakehead. Ontogenic shifts in adult northern snakehead diet were also detected, which may be explained by optimal foraging rather than true prey specificity. Northern snakehead may be occupying a novel niche based on a piscivorous diet, therefore limiting competition with resident predators in the lower Potomac River. Further research into interactions between largemouth bass and northern snakehead is needed to inform management decisions and understand the ecological impacts of this non-native species.

  12. Strategies for Improving Academic Performance by Non-Native English Speakers in Graduate Programs

    Science.gov (United States)

    Todd, Tracye A.; Stinson, Terrye A.; Sivakumaran, Thillainatarajan

    2011-01-01

    Over the past decade, the number of non-native English speaking students in higher education has increased dramatically. Educators at all levels have experienced challenges in meeting the academic needs of these students and continue to seek strategies for addressing these challenges. This paper describes some of this research related to K-12 and…

  13. Proficient beyond borders: assessing non-native speakers in a native speakers’ framework

    Directory of Open Access Journals (Sweden)

    Johanna Fleckenstein

    2016-11-01

    Full Text Available Abstract Background English language proficiency is considered a basic skill that students from different language backgrounds are expected to master, independent of whether they are native or non-native speakers. Tests that measure language proficiency in non-native speakers are typically linked to the common European framework of reference for languages. Such tests, however, often lack the criteria to define a practically relevant degree of proficiency in English. We approach this deficit by assessing non-native speakers’ performance within a native speakers’ framework. Method Items from two English reading assessments—the Programme for International Student Assessment (PISA and the National Assessment (NA for English as a foreign language in Germany—were administered to N = 427 German high school students. Student abilities were estimated by drawing plausible values in a two-dimensional Rasch model. Results Results show that non-native speakers of English generally underperformed compared to native speakers. However, academic track students in the German school system achieved satisfactory levels of proficiency on the PISA scale. Linking the two scales showed systematic differences in the proficiency level classifications. Conclusion The findings contribute to the validation and international localization of NA standards for English as a foreign language. Practical implications are discussed with respect to policy-defined benchmarks for the successful participation in a global English-speaking society.

  14. TOEFL11: A Corpus of Non-Native English. Research Report. ETS RR-13-24

    Science.gov (United States)

    Blanchard, Daniel; Tetreault, Joel; Higgins, Derrick; Cahill, Aoife; Chodorow, Martin

    2013-01-01

    This report presents work on the development of a new corpus of non-native English writing. It will be useful for the task of native language identification, as well as grammatical error detection and correction, and automatic essay scoring. In this report, the corpus is described in detail.

  15. The online application of binding condition B in native and non-native pronoun resolution.

    Science.gov (United States)

    Patterson, Clare; Trompelt, Helena; Felser, Claudia

    2014-01-01

    Previous research has shown that anaphor resolution in a non-native language may be more vulnerable to interference from structurally inappropriate antecedents compared to native anaphor resolution. To test whether previous findings on reflexive anaphors generalize to non-reflexive pronouns, we carried out an eye-movement monitoring study investigating the application of binding condition B during native and non-native sentence processing. In two online reading experiments we examined when during processing local and/or non-local antecedents for pronouns were considered in different types of syntactic environment. Our results demonstrate that both native English speakers and native German-speaking learners of English showed online sensitivity to binding condition B in that they did not consider syntactically inappropriate antecedents. For pronouns thought to be exempt from condition B (so-called "short-distance pronouns"), the native readers showed a weak preference for the local antecedent during processing. The non-native readers, on the other hand, showed a preference for the matrix subject even where local coreference was permitted, and despite demonstrating awareness of short-distance pronouns' referential ambiguity in a complementary offline task. This indicates that non-native comprehenders are less sensitive during processing to structural cues that render pronouns exempt from condition B, and prefer to link a pronoun to a salient subject antecedent instead.

  16. Taiwanese University Students' Attitudes to Non-Native Speakers English Teachers

    Science.gov (United States)

    Chang, Feng-Ru

    2016-01-01

    Numerous studies have been conducted to explore issues surrounding non-native speakers (NNS) English teachers and native speaker (NS) teachers which concern, among others, the comparison between the two, the self-perceptions of NNS English teachers and the effectiveness of their teaching, and the students' opinions on and attitudes towards them.…

  17. Ethical Considerations in Conducting Research with Non-Native Speakers of English

    Science.gov (United States)

    Koulouriotis, Joanna

    2011-01-01

    The ethical considerations of three education researchers working with non-native English-speaking participants were examined from a critical theory stand-point in the light of the literature on research ethics in various disciplines. Qualitative inquiry and data analysis were used to identify key themes, which centered around honor and respect…

  18. A Corpus-Based Study of Adverbial Connectors in Native and Non-native Students’ Writing

    DEFF Research Database (Denmark)

    WANG, Yan-jun; Li, Rui

    2016-01-01

    , this paper firstly makes a comparison to the usage of adverbial connectors in their writings of the native students and non-native students and then exposes a distinctive gap between these two types of writings in usage of adverbial connectors. In order to help Chinese second-language learners acquire...

  19. Facebook-Photovoice Interface: Empowering Non-Native Pre-Service English Language Teachers

    Science.gov (United States)

    Rubrico, Jessie Grace U.; Hashim, Fatimah

    2014-01-01

    Engaging non-native pre-service English teachers who are still learning the language themselves requires two tasks: facilitating their language teaching skills and scaffolding their language learning. This action research interfaced Facebook and Photovoice technologies in order to empower participants to be proactive in their language learning and…

  20. The Knowledge Base of Non-Native English-Speaking Teachers: Perspectives of Teachers and Administrators

    Science.gov (United States)

    Zhang, Fengjuan; Zhan, Ju

    2014-01-01

    This study explores the knowledge base of non-native English-speaking teachers (NNESTs) working in the Canadian English as a second language (ESL) context. By examining NNESTs' experiences in seeking employment and teaching ESL in Canada, and investigating ESL program administrators' perceptions and hiring practices in relation to NNESTs, it…

  1. Comparison of native and non-native phone imitation by English and Spanish speakers.

    Science.gov (United States)

    Olmstead, Anne J; Viswanathan, Navin; Aivar, M Pilar; Manuel, Sarath

    2013-01-01

    Experiments investigating phonetic convergence in conversation often focus on interlocutors with similar phonetic inventories. Extending these experiments to those with dissimilar inventories requires understanding the capacity of speakers to imitate native and non-native phones. In the present study, we tested native Spanish and native English speakers to determine whether imitation of non-native tokens differs qualitatively from imitation of native tokens. Participants imitated a [ba]-[pa] continuum that varied in VOT from -60 ms (prevoiced, Spanish [b]) to +60 ms (long lag, English [p]) such that the continuum consisted of some tokens that were native to Spanish speakers and some that were native to English speakers. Analysis of the imitations showed two critical results. First, both groups of speakers demonstrated sensitivity to VOT differences in tokens that fell within their native regions of the VOT continuum (prevoiced region for Spanish and long lag region for English). Secondly, neither group of speakers demonstrated such sensitivity to VOT differences among tokens that fell in their non-native regions of the continuum. These results show that, even in an intentional imitation task, speakers cannot accurately imitate non-native tokens, but are clearly flexible in producing native tokens. Implications of these findings are discussed with reference to the constraints on convergence in interlocutors from different linguistic backgrounds.

  2. Fitness benefits of the fruit fly Rhagoletis alternata on a non-native rose host

    NARCIS (Netherlands)

    Meijer, Kim; Smit, Christian; Schilthuizen, Menno; Beukeboom, Leo W.

    2016-01-01

    Many species have been introduced worldwide into areas outside their natural range. Often these non-native species are introduced without their natural enemies, which sometimes leads to uncontrolled population growth. It is rarely reported that an introduced species provides a new resource for a nat

  3. Patterns of English phoneme confusions by native and non-native listeners

    NARCIS (Netherlands)

    Cutler, A.; Weber, A.C.; Smits, R.; Cooper, N.

    2004-01-01

    Native American English and non-native (Dutch) listeners identified either the consonant or the vowel in all possible American English CV and VC syllables. The syllables were embedded in multispeaker babble at three signal-to-noise ratios (0, 8, and 16 dB). The phoneme identification performance of

  4. Juggling Identity and Authority: A Case Study of One Non-Native Instructor of English

    Science.gov (United States)

    Subtirelu, Nicholas

    2011-01-01

    Authority in the classroom is an important concept to teachers everywhere. The act of teaching continuously engages them in the negotiation and construction of an identity that is accepted as authoritative by their students. Identity and authority, however, are in conflict in the context of NNSTs ["non-native" speaker teachers] of English (and…

  5. User requirement analysis of social conventions learning applications for non-natives and low-literates

    NARCIS (Netherlands)

    Schouten, Dylan; Smets, Nanja; Driessen, Marianne; Hanekamp, Marieke; Cremers, Ania

    2013-01-01

    Learning and acting on social conventions is problematic for low-literates and non-natives, causing problems with societal participation and citizenship. Using the Situated Cognitive Engineering method, requirements for the design of social conventions learning software are derived from demographic

  6. Non-Native English-Speaking Teachers, Context and English Language Teaching

    Science.gov (United States)

    Hayes, David

    2009-01-01

    This article contends that, in spite of a recent upsurge in writing on non-native English-speaking teachers (NNESTs) in the global discourse of English language teaching (ELT), the experiences of NNESTSs working within their own state educational systems remain seriously under-investigated. To help to redress this, the article explores, from their…

  7. The online application of binding condition B in native and non-native pronoun resolution

    Directory of Open Access Journals (Sweden)

    Clare ePatterson

    2014-02-01

    Full Text Available Previous research has shown that anaphor resolution in a non-native language may be more vulnerable to interference from structurally inappropriate antecedents compared to native anaphor resolution. To test whether previous findings on reflexive anaphors generalise to non-reflexive pronouns, we carried out an eye-movement monitoring study investigating the application of binding condition B during native and non-native sentence processing. In two online reading experiments we examined when during processing local and/or non-local antecedents for pronouns were considered in different types of syntactic environment. Our results demonstrate that both native English speakers and native German-speaking learners of English showed online sensitivity to binding condition B in that they did not consider syntactically inappropriate antecedents. For pronouns thought to be exempt from condition B (so-called 'short-distance pronouns', the native readers showed a weak preference for the local antecedent during processing. The non-native readers, on the other hand, showed a preference for the matrix subject even where local coreference was permitted, and despite demonstrating awareness of short-distance pronouns' referential ambiguity in a complementary offline task. This indicates that non-native comprehenders are less sensitive during processing to structural cues that render pronouns exempt from condition B, and prefer to link a pronoun to a salient subject antecedent instead.

  8. Expansion and fragment settlement of the non-native seagrass Halophila stipulacea in a Caribbean bay

    NARCIS (Netherlands)

    Smulders, Fee O.H.; Vonk, J.A.; Engel, M.S.; Christianen, Marjolijn J.A.

    2017-01-01

    The non-native seagrass species Halophila stipulacea has spread throughout the Eastern Caribbean since 2002, and could potentially impact the functioning of local seagrass ecosystems. Important characteristics for invasiveness, such as dispersal, recruitment and expansion of H. stipulacea at a lo

  9. Perception of Non-Native Consonant Length Contrast: The Role of Attention in Phonetic Processing

    Science.gov (United States)

    Porretta, Vincent J.; Tucker, Benjamin V.

    2015-01-01

    The present investigation examines English speakers' ability to identify and discriminate non-native consonant length contrast. Three groups (L1 English No-Instruction, L1 English Instruction, and L1 Finnish control) performed a speeded forced-choice identification task and a speeded AX discrimination task on Finnish non-words (e.g.…

  10. Native- and Non-Native Speaking English Teachers in Vietnam: Weighing the Benefits

    Science.gov (United States)

    Walkinshaw, Ian; Duong, Oanh Thi Hoang

    2012-01-01

    This paper examines a common belief that learners of English as a foreign language prefer to learn English from native-speaker teachers rather than non-native speakers of English. 50 Vietnamese learners of English evaluated the importance of native-speakerness compared with seven qualities valued in an English language teacher: teaching…

  11. Invasions by two non-native insects alter regional forest species composition and successional trajectories

    Science.gov (United States)

    Randall S. Morin; Andrew M. Liebhold

    2015-01-01

    While invasions of individual non-native phytophagous insect species are known to affect growth and mortality of host trees, little is known about how multiple invasions combine to alter forest dynamics over large regions. In this study we integrate geographical data describing historical invasion spread of the hemlock woolly adelgid, Adelges tsugae...

  12. Risk to native Uroleucon aphids (Hemiptera: Aphididae) from non-native lady beetles (Coleoptera: Coccinellidae)

    Science.gov (United States)

    Aphids in the genus Uroleucon Mordvilko (Hemiptera: Aphididae) are native herbivores that feed on goldenrod (Solidago spp.) and other Asteraceae in North America. The aphids are potential prey for a wide variety of natural enemies, including native and non-native species of lady beetles (Coleoptera...

  13. Predicting establishment of non-native fishes in Greece: identifying key features

    Directory of Open Access Journals (Sweden)

    Christos Gkenas

    2015-11-01

    Full Text Available Non-native fishes are known to cause economic damage to human society and are considered a major threat to biodiversity loss in freshwater ecosystems. The growing concern about these impacts has driven to an investigation of the biological traits that facilitate the establishment of non-native fish. However, invalid assessment in choosing the appropriate statistical model can lead researchers to ambiguous conclusions. Here, we present a comprehensive comparison of traditional and alternative statistical methods for predicting fish invasions using logistic regression, classification trees, multicorrespondence analysis and random forest analysis to determine characteristics of successful and failed non-native fishes in Hellenic Peninsula through establishment. We defined fifteen categorical predictor variables with biological relevance and measures of human interest. Our study showed that accuracy differed according to the model and the number of factors considered. Among all the models tested, random forest and logistic regression performed best, although all approaches predicted non-native fish establishment with moderate to excellent results. Detailed evaluation among the models corresponded with differences in variables importance, with three biological variables (parental care, distance from nearest native source and maximum size and two variables of human interest (prior invasion success and propagule pressure being important in predicting establishment. The analyzed statistical methods presented have a high predictive power and can be used as a risk assessment tool to prevent future freshwater fish invasions in this region with an imperiled fish fauna.

  14. Computer Vision Syndrome for Non-Native Speaking Students: What Are the Problems with Online Reading?

    Science.gov (United States)

    Tseng, Min-chen

    2014-01-01

    This study investigated the online reading performances and the level of visual fatigue from the perspectives of non-native speaking students (NNSs). Reading on a computer screen is more visually more demanding than reading printed text. Online reading requires frequent saccadic eye movements and imposes continuous focusing and alignment demand.…

  15. 5.0 Monitoring methods for forests vulnerable to non-native invasive pest species

    Science.gov (United States)

    David W. Williams; Michael E. Montgomery; Kathleen S. Shields; Richard A. Evans

    2008-01-01

    Non-native invasive species pose a serious threat to forest resources, requiring programs to monitor their spatial spread and the damage they inflict on forest ecosystems. Invasive species research in the Delaware River Basin (DRB) had three primary objectives: to develop and evaluate monitoring protocols for selected pests and resulting ecosystem damage at the IMRAs...

  16. Computer Vision Syndrome for Non-Native Speaking Students: What Are the Problems with Online Reading?

    Science.gov (United States)

    Tseng, Min-chen

    2014-01-01

    This study investigated the online reading performances and the level of visual fatigue from the perspectives of non-native speaking students (NNSs). Reading on a computer screen is more visually more demanding than reading printed text. Online reading requires frequent saccadic eye movements and imposes continuous focusing and alignment demand.…

  17. Facebook-Photovoice Interface: Empowering Non-Native Pre-Service English Language Teachers

    Science.gov (United States)

    Rubrico, Jessie Grace U.; Hashim, Fatimah

    2014-01-01

    Engaging non-native pre-service English teachers who are still learning the language themselves requires two tasks: facilitating their language teaching skills and scaffolding their language learning. This action research interfaced Facebook and Photovoice technologies in order to empower participants to be proactive in their language learning and…

  18. Non-Native English Language Teachers' Perspective on Culture in English as a Foreign Language Classrooms

    Science.gov (United States)

    Bayyurt, Yasemin

    2006-01-01

    This article examines the importance of raising non-native English language teachers' awareness of different dimensions of culture in the teaching of English as an international language. The author believes that the more critical English language teachers become about the involvement of culture in their English language teaching, the more they…

  19. Using the Speech Transmission Index for predicting non-native speech intelligibility

    NARCIS (Netherlands)

    Wijngaarden, S.J. van; Bronkhorst, A.W.; Houtgast, T.; Steeneken, H.J.M.

    2004-01-01

    While the Speech Transmission Index ~STI! is widely applied for prediction of speech intelligibility in room acoustics and telecommunication engineering, it is unclear how to interpret STI values when non-native talkers or listeners are involved. Based on subjectively measured psychometric functions

  20. Comparison of native and non-native phone imitation by English and Spanish speakers

    Directory of Open Access Journals (Sweden)

    Annie J Olmstead

    2013-07-01

    Full Text Available Experiments investigating phonetic convergence in conversation often focus on interlocutors with similar phonetic inventories. Extending these experiments to those with dissimilar inventories requires understanding the capacity of speakers to imitate native and non-native phones. In the present study, we tested native Spanish and native English speakers to determine whether imitation of non-native tokens differs qualitatively from imitation of native tokens. Participants imitated a [ba] -[pa] continuum that varied in VOT from -60 ms (prevoiced, Spanish [b] to +60 ms (long lag, English [p] such that the continuum consisted of some tokens that were native to Spanish speakers and some that were native to English speakers. Analysis of the imitations showed two critical results. First, both groups of speakers demonstrated sensitivity to VOT differences in tokens that fell within their native regions of the VOT continuum (prevoiced region for Spanish and long lag region for English. Secondly, neither group of speakers demonstrated such sensitivity to VOT differences among tokens that fell in their non-native regions of the continuum. These results show that, even in an intentional imitation task, speakers cannot accurately imitate non-native tokens, but are clearly flexible in producing native tokens. Implications of these findings are discussed with reference to the constraints on convergence in interlocutors from different linguistic backgrounds.

  1. Early detection of non-native fishes using next-generation DNA sequencing of fish larvae

    Science.gov (United States)

    Our objective was to evaluate the use of fish larvae for early detection of non-native fishes, comparing traditional and molecular taxonomy based on next-generation DNA sequencing to investigate potential efficiencies. Our approach was to intensively sample a Great Lakes non-nati...

  2. User requirement analysis of social conventions learning applications for Non-natives and low-literates

    NARCIS (Netherlands)

    Schouten, D.; Smets, N.; Driessen, M.; Hanekamp, M.; Cremers, A.H.M.; Neerincx, M.A.

    2013-01-01

    Learning and acting on social conventions is problematic for low-literates and non-natives, causing problems with societal participation and citizenship. Using the Situated Cognitive Engineering method, requirements for the design of social conventions learning software are derived from demographic

  3. Linguistic Support for Non-Native English Speakers: Higher Education Practices in the United States

    Science.gov (United States)

    Snow Andrade, Maureen; Evans, Norman W.; Hartshorn, K. James

    2014-01-01

    Higher education institutions in English-speaking nations host significant populations of non-native English speakers (NNES), both international and resident. English language proficiency is a critical factor to their success. This study reviews higher education practices in the United States related to this population. Findings indicate…

  4. User requirement analysis of social conventions learning applications for Non-natives and low-literates

    NARCIS (Netherlands)

    Schouten, D.; Smets, N.; Driessen, M.; Hanekamp, M.; Cremers, A.H.M.; Neerincx, M.A.

    2013-01-01

    Learning and acting on social conventions is problematic for low-literates and non-natives, causing problems with societal participation and citizenship. Using the Situated Cognitive Engineering method, requirements for the design of social conventions learning software are derived from demographic

  5. Using the Speech Transmission Index for predicting non-native speech intelligibility

    NARCIS (Netherlands)

    Wijngaarden, S.J. van; Bronkhorst, A.W.; Houtgast, T.; Steeneken, H.J.M.

    2004-01-01

    While the Speech Transmission Index ~STI! is widely applied for prediction of speech intelligibility in room acoustics and telecommunication engineering, it is unclear how to interpret STI values when non-native talkers or listeners are involved. Based on subjectively measured psychometric functions

  6. To What Extent Do Native and Non-Native Writers Make Use of Collocations?

    Science.gov (United States)

    Durrant, Philip; Schmitt, Norbert

    2009-01-01

    Usage-based models claim that first language learning is based on the frequency-based analysis of memorised phrases. It is not clear though, whether adult second language learning works in the same way. It has been claimed that non-native language lacks idiomatic formulas, suggesting that learners neglect phrases, focusing instead on orthographic…

  7. Quantifying the intelligibility of speech in noise for non-native listeners

    NARCIS (Netherlands)

    Wijngaarden, S.J. van; Steeneken, H.J.M.; Houtgast, T.

    2002-01-01

    When listening to languages learned at a later age, speech intelligibility is generally lower than when listening to one's native language. The main purpose of this study is to quantify speech intelligibility in noise for specific populations of non-native listeners, only broadly addressing the unde

  8. Non-native and native organisms moving into high elevation and high latitude ecosystems in an era of climate change

    DEFF Research Database (Denmark)

    Pauchard, Aníbal; Milbau, Ann; Albihn, Ann;

    2016-01-01

    Cold environments at high elevation and high latitude are often viewed as resistant to biological invasions. However, climate warming, land use change and associated increased connectivity all increase the risk of biological invasions in these environments. Here we present a summary of the key...... discussions of the workshop ‘Biosecurity in Mountains and Northern Ecosystems: Current Status and Future Challenges’ (Flen, Sweden, 1–3 June 2015). The aims of the workshop were to (1) increase awareness about the growing importance of species expansion—both non-native and native—at high elevation and high......, especially if it is coupled with prioritisation schemes for targeting invaders likely to have greatest impact. Communication and co-operation between cold environment regions will facilitate rapid response, and maximise the use of limited research and management resources....

  9. Novice Non-Native English Teachers’ Reflections on Their Teacher Education Programmes and Their First Years of Teaching

    Directory of Open Access Journals (Sweden)

    Sumru Akcan

    2016-01-01

    Full Text Available This study investigates novice non-native English teachers’ opinions about the effectiveness of their teacher education programme and the challenges during their initial years of teaching. The results of a survey administered to fifty-five novice teachers and follow-up interviews identify strengths and weaknesses in their teacher education programme and catalogue the difficulties they faced when they star-ted to teach. The study found significant differences between the content of novice teachers’ academic courses in their teacher education programme and the conditions they experienced in classrooms. The major challenges of their first years of teaching were related to lesson delivery, managing behaviour, unmotivated students, and students with learning disabilities. The article includes suggestions to prepare teachers for the actualities of working in schools.

  10. A non-native prey mediates the effects of a shared predator on an ecosystem service.

    Directory of Open Access Journals (Sweden)

    James E Byers

    Full Text Available Non-native species can alter ecosystem functions performed by native species often by displacing influential native species. However, little is known about how ecosystem functions may be modified by trait-mediated indirect effects of non-native species. Oysters and other reef-associated filter feeders enhance water quality by controlling nutrients and contaminants in many estuarine environments. However, this ecosystem service may be mitigated by predation, competition, or other species interactions, especially when such interactions involve non-native species that share little evolutionary history. We assessed trophic and other interference effects on the critical ecosystem service of water filtration in mesocosm experiments. In single-species trials, typical field densities of oysters (Crassostrea virginica reduced water-column chlorophyll a more strongly than clams (Mercenaria mercenaria. The non-native filter-feeding reef crab Petrolisthes armatus did not draw down chlorophyll a. In multi-species treatments, oysters and clams combined additively to influence chlorophyll a drawdown. Petrolisthes did not affect net filtration when added to the bivalve-only treatments. Addition of the predatory mud crab Panopeus herbstii did not influence oyster feeding rates, but it did stop chlorophyll a drawdown by clams. However, when Petrolisthes was also added in with the clams, the clams filtered at their previously unadulterated rates, possibly because Petrolisthes drew the focus of predators or habituated the clams to crab stimuli. In sum, oysters were the most influential filter feeder, and neither predators nor competitors interfered with their net effect on water-column chlorophyll. In contrast, clams filtered less, but were more sensitive to predators as well as a facilitative buffering effect of Petrolisthes, illustrating that non-native species can indirectly affect an ecosystem service by aiding the performance of a native species.

  11. Loss of biodiversity in a conservation unit of the Brazilian Atlantic Forest: the effect of introducing non-native fish species.

    Science.gov (United States)

    Fragoso-Moura, E N; Oporto, L T; Maia-Barbosa, P M; Barbosa, F A R

    2016-02-01

    The introduction of species has become an important problem for biodiversity and natural ecosystem conservation. The lake system of the middle Rio Doce (MG, Brazil) comprises c. 200 lakes at various conservation states, of which 50 are located within the Rio Doce State Park (PERD). Previous studies had verified several of these lakes suffered non-native fishes introductions and the presence of these species needs for the implementation of actions aiming at not only their control but also the preservation of the native species. This study discusses the effects of non-native fish species in the largest conservation unit of Atlantic Forest in Minas Gerais, southeast of Brazil, using data from 1983 to 2010 distributed as follow: data prior to 2006 were obtained from previous studies, and data from September 2006 to July 2010 were obtained in Lake Carioca at four sampling stations using gillnets, seine nets and sieve. A total of 17 fish species was collected (2006-2010) of which five were introduced species. Among the small to medium size native species (30 to 2000 mm standard length) seven had disappeared, two are new records and one was recaptured. The non-native species Cichla kelberi (peacock bass) and Pygocentrus nattereri (red piranha) are within the most abundant captured species. Integrated with other actions, such as those preventing new introductions, a selective fishing schedule is proposed as an alternative approach to improve the conservation management actions and the local and regional biodiversity maintenance.

  12. Tolerance of native and non-native fish species to chemical stress: a case study for the River Rhine

    NARCIS (Netherlands)

    A. Fedorenkova; J.A. Vonk; A.M. Breure; A.J. Hendriks; R.S.E.W. Leuven

    2013-01-01

    Freshwater ecosystems can be impacted by invasive species. Non-native species can become invasive due to their high tolerance to environmental stressors (e.g., pollution and habitat modifications). Yet, tolerance of native and non-native fish species exposed simultaneously to multiple chemical stres

  13. Higher dropout rate in non-native patients than in native patients in rehabilitation in The Netherlands

    NARCIS (Netherlands)

    Sloots, Maurits; Scheppers, Emmanuel F.; van de Weg, Frans B.; Bartels, Edien A.; Geertzen, Jan H.; Dekker, Joost; Dekker, Jaap

    2009-01-01

    Dropout from a rehabilitation programme often occurs in patients with chronic nonspecific low back pain of non-native origin. However, the exact dropout rate is not known. The objective of this study was to determine the difference in dropout rate between native and non-native patients with chronic

  14. Intelligibility of non-natively produced Dutch words: interaction between segmental and suprasegmental errors.

    Science.gov (United States)

    Caspers, Johanneke; Horłoza, Katarzyna

    2012-01-01

    In the field of second language research many adhere to the idea that prosodic errors are more detrimental to the intelligibility of non-native speakers than segmental errors. The current study reports on a series of experiments testing the influence of stress errors and segmental errors, and a combination of these, on native processing of words produced by intermediate speakers of Dutch as a second language with either Mandarin Chinese or French as mother tongue. The results suggest that both stress and segmental errors influence processing, but suprasegmental errors do not outweigh segmental errors. It seems that a more 'foreign' generic pronunciation leads to a greater impact of (supra)segmental errors, suggesting that segmental and prosodic deviations should not be viewed as independent factors in processing non-native speech.

  15. Mental health status in pregnancy among native and non-native Swedish-speaking women

    DEFF Research Database (Denmark)

    Wangel, Anne-Marie; Schei, Berit; Ryding, Elsa Lena

    2012-01-01

    OBJECTIVES: To describe mental health status in native and non-native Swedish-speaking pregnant women and explore risk factors of depression and posttraumatic stress (PTS) symptoms. DESIGN AND SETTING: A cross-sectional questionnaire study was conducted at midwife-based antenatal clinics in South......OBJECTIVES: To describe mental health status in native and non-native Swedish-speaking pregnant women and explore risk factors of depression and posttraumatic stress (PTS) symptoms. DESIGN AND SETTING: A cross-sectional questionnaire study was conducted at midwife-based antenatal clinics...... in Southern Sweden. SAMPLE: A non-selected group of women in mid-pregnancy. METHODS: Participants completed a questionnaire covering background characteristics, social support, life events, mental health variables and the short Edinburgh Depression Scale. MAIN OUTCOME MEASURES: Depressive symptoms during...

  16. Teaching Media in the Teaching of Arabic Language to Non-Native Arabic Speakers

    Directory of Open Access Journals (Sweden)

    Rais Abdullah

    2016-06-01

    Full Text Available Learning media has demonstrated its superiority in helping educators or teachers in the process of conveying the message of learning more quickly and easily caught by the students. The media play a role in enriching the learning experience of students, increase their attention to the lesson, minimize differences in perception between teachers and students as well as to help resolve personal differences between students. The teaching Arabic to non-native speaker would be more interesting and easier to learn, remembered, understood and practiced by the students, if taught through the media. This article aims to explore the benefits, importance and role of instructional media in teaching Arabic to non- native Speaker

  17. Non-native salmonids affect amphibian occupancy at multiple spatial scales

    Science.gov (United States)

    Pilliod, David S.; Hossack, Blake R.; Bahls, Peter F.; Bull, Evelyn L.; Corn, Paul Stephen; Hokit, Grant; Maxell, Bryce A.; Munger, James C.; Wyrick, Aimee

    2010-01-01

    Aim The introduction of non-native species into aquatic environments has been linked with local extinctions and altered distributions of native species. We investigated the effect of non-native salmonids on the occupancy of two native amphibians, the long-toed salamander (Ambystoma macrodactylum) and Columbia spotted frog (Rana luteiventris), across three spatial scales: water bodies, small catchments and large catchments. Location Mountain lakes at ≥ 1500 m elevation were surveyed across the northern Rocky Mountains, USA. Methods We surveyed 2267 water bodies for amphibian occupancy (based on evidence of reproduction) and fish presence between 1986 and 2002 and modelled the probability of amphibian occupancy at each spatial scale in relation to habitat availability and quality and fish presence. Results After accounting for habitat features, we estimated that A. macrodactylum was 2.3 times more likely to breed in fishless water bodies than in water bodies with fish. Ambystoma macrodactylum also was more likely to occupy small catchments where none of the water bodies contained fish than in catchments where at least one water body contained fish. However, the probability of salamander occupancy in small catchments was also influenced by habitat availability (i.e. the number of water bodies within a catchment) and suitability of remaining fishless water bodies. We found no relationship between fish presence and salamander occupancy at the large-catchment scale, probably because of increased habitat availability. In contrast to A. macrodactylum, we found no relationship between fish presence and R. luteiventris occupancy at any scale. Main conclusions Our results suggest that the negative effects of non-native salmonids can extend beyond the boundaries of individual water bodies and increase A. macrodactylum extinction risk at landscape scales. We suspect that niche overlap between non-native fish and A. macrodactylum at higher elevations in the northern Rocky

  18. Non-native novice EFL teachers' beliefs about teaching and learning

    OpenAIRE

    Erkmen, Besime

    2010-01-01

    This study investigated the beliefs about teaching and learning English of nine non-native novice teachers at a private university in Northern Cyprus, and the extent to which these beliefs changed in their first year of teaching. Data was collected over an academic year of nine months by means of semi-structured interviews, credos, classroom observations, post-lesson reflection forms, stimulated-recall interviews, diaries and a metaphor-elicitation task. The study found that novice teachers’ ...

  19. Emergence of category-level sensitivities in non-native speech sound learning

    Directory of Open Access Journals (Sweden)

    Emily eMyers

    2014-08-01

    Full Text Available Over the course of development, speech sounds that are contrastive in one’s native language tend to become perceived categorically: that is, listeners are unaware of variation within phonetic categories while showing excellent sensitivity to speech sounds that span linguistically meaningful phonetic category boundaries. The end stage of this developmental process is that the perceptual systems that handle acoustic-phonetic information show special tuning to native language contrasts, and as such, category-level information appears to be present at even fairly low levels of the neural processing stream. Research on adults acquiring non-native speech categories offers an avenue for investigating the interplay of category-level information and perceptual sensitivities to these sounds as speech categories emerge. In particular, one can observe the neural changes that unfold as listeners learn not only to perceive acoustic distinctions that mark non-native speech sound contrasts, but also to map these distinctions onto category-level representations. An emergent literature on the neural basis of novel and non-native speech sound learning offers new insight into this question. In this review, I will examine this literature in order to answer two key questions. First, where in the neural pathway does sensitivity to category-level phonetic information first emerge over the trajectory of speech sound learning? Second, how do frontal and temporal brain areas work in concert over the course of non-native speech sound learning? Finally, in the context of this literature I will describe a model of speech sound learning in which rapidly-adapting access to categorical information in the frontal lobes modulates the sensitivity of stable, slowly-adapting responses in the temporal lobes.

  20. Increased Abundance of Native and Non-Native Spiders With Habitat Fragmentation

    OpenAIRE

    Bolger, Douglas T.; Beard, Karen H.; Suarez, Andrew; Case, Ted

    2008-01-01

    Habitat fragmentation and invasive species often contribute to the decline of native taxa. Since the penetration of non-native species into natural habitat may be facilitated by habitat fragmentation, it is important to examine how these two factors interact. Previous research documented that, in contrast to most other arthropod taxa, spiders increased in density and morphospecies richness with decreasing fragment area and increasing fragment age (time since insularization) in urban habitat f...

  1. A Hybrid Acoustic and Pronunciation Model Adaptation Approach for Non-native Speech Recognition

    Science.gov (United States)

    Oh, Yoo Rhee; Kim, Hong Kook

    In this paper, we propose a hybrid model adaptation approach in which pronunciation and acoustic models are adapted by incorporating the pronunciation and acoustic variabilities of non-native speech in order to improve the performance of non-native automatic speech recognition (ASR). Specifically, the proposed hybrid model adaptation can be performed at either the state-tying or triphone-modeling level, depending at which acoustic model adaptation is performed. In both methods, we first analyze the pronunciation variant rules of non-native speakers and then classify each rule as either a pronunciation variant or an acoustic variant. The state-tying level hybrid method then adapts pronunciation models and acoustic models by accommodating the pronunciation variants in the pronunciation dictionary and by clustering the states of triphone acoustic models using the acoustic variants, respectively. On the other hand, the triphone-modeling level hybrid method initially adapts pronunciation models in the same way as in the state-tying level hybrid method; however, for the acoustic model adaptation, the triphone acoustic models are then re-estimated based on the adapted pronunciation models and the states of the re-estimated triphone acoustic models are clustered using the acoustic variants. From the Korean-spoken English speech recognition experiments, it is shown that ASR systems employing the state-tying and triphone-modeling level adaptation methods can relatively reduce the average word error rates (WERs) by 17.1% and 22.1% for non-native speech, respectively, when compared to a baseline ASR system.

  2. Incorporating fragmentation and non-native species into distribution models to inform fluvial fish conservation.

    Science.gov (United States)

    Taylor, Andrew T; Papeş, Monica; Long, James M

    2017-09-06

    Fluvial fishes face increased imperilment from anthropogenic activities, but the specific factors contributing most to range declines are often poorly understood. For example, the shoal bass (Micropterus cataractae) is a fluvial-specialist species experiencing continual range loss, yet how perceived threats have contributed to range loss is largely unknown. We employed species distribution models (SDMs) to disentangle which factors are contributing most to shoal bass range loss by estimating a potential distribution based on natural abiotic factors and by estimating a series of current, occupied distributions that also incorporated variables characterizing land cover, non-native species, and fragmentation intensity (no fragmentation, dams only, and dams and large impoundments). Model construction allowed for interspecific relationships between non-native congeners and shoal bass to vary across fragmentation intensities. Results from the potential distribution model estimated shoal bass presence throughout much of their native basin, whereas models of current occupied distribution illustrated increased range loss as fragmentation intensified. Response curves from current occupied models indicated a potential interaction between fragmentation intensity and the relationship between shoal bass and non-native congeners, wherein non-natives may be favored at the highest fragmentation intensity. Response curves also suggested that free-flowing fragment lengths of > 100 km were necessary to support shoal bass presence. Model evaluation, including an independent validation, suggested models had favorable predictive and discriminative abilities. Similar approaches that use readily-available, diverse geospatial datasets may deliver insights into the biology and conservation needs of other fluvial species facing similar threats. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  3. An invasive non-native mammal population conserves genetic diversity lost from its native range.

    Science.gov (United States)

    Veale, A J; Holland, O J; McDonald, R A; Clout, M N; Gleeson, D M

    2015-05-01

    Invasive, non-native species are one of the major causes of global biodiversity loss. Although they are, by definition, successful in their non-native range, their populations generally show major reductions in their genetic diversity during the demographic bottleneck they experience during colonization. By investigating the mitochondrial genetic diversity of an invasive non-native species, the stoat Mustela erminea, in New Zealand and comparing it to diversity in the species' native range in Great Britain, we reveal the opposite effect. We demonstrate that the New Zealand stoat population contains four mitochondrial haplotypes that have not been found in the native range. Stoats in Britain rely heavily on introduced rabbits Oryctolagus cuniculus as their primary prey and were introduced to New Zealand in a misguided attempt at biological control of rabbits, which had also been introduced there. While invasive stoats have since decimated the New Zealand avifauna, native stoat populations were themselves decimated by the introduction to Britain of Myxoma virus as a control measure for rabbits. We highlight the irony that while introduced species (rabbits) and subsequent biocontrol (myxomatosis) have caused population crashes of native stoats, invasive stoats in New Zealand, which were also introduced for biological control, now contain more genetic haplotypes than their most likely native source. © 2015 John Wiley & Sons Ltd.

  4. Invasion of non-native grasses causes a drop in soil carbon storage in California grasslands

    Science.gov (United States)

    Koteen, Laura E.; Baldocchi, Dennis D.; Harte, John

    2011-10-01

    Vegetation change can affect the magnitude and direction of global climate change via its effect on carbon cycling among plants, the soil and the atmosphere. The invasion of non-native plants is a major cause of land cover change, of biodiversity loss, and of other changes in ecosystem structure and function. In California, annual grasses from Mediterranean Europe have nearly displaced native perennial grasses across the coastal hillsides and terraces of the state. Our study examines the impact of this invasion on carbon cycling and storage at two sites in northern coastal California. The results suggest that annual grass invasion has caused an average drop in soil carbon storage of 40 Mg/ha in the top half meter of soil, although additional mechanisms may also contribute to soil carbon losses. We attribute the reduction in soil carbon storage to low rates of net primary production in non-native annuals relative to perennial grasses, a shift in rooting depth and water use to primarily shallow sources, and soil respiratory losses in non-native grass soils that exceed production rates. These results indicate that even seemingly subtle land cover changes can significantly impact ecosystem functions in general, and carbon storage in particular.

  5. Invasion of non-native grasses causes a drop in soil carbon storage in California grasslands

    Energy Technology Data Exchange (ETDEWEB)

    Koteen, Laura E; Harte, John [Energy and Resources Group, 310 Barrows Hall, University of California, Berkeley, CA 94720 (United States); Baldocchi, Dennis D, E-mail: lkoteen@berkeley.edu [Department of Environmental Science, Policy and Management, 137 Mulford Hall, University of California, Berkeley, CA 94720 (United States)

    2011-10-15

    Vegetation change can affect the magnitude and direction of global climate change via its effect on carbon cycling among plants, the soil and the atmosphere. The invasion of non-native plants is a major cause of land cover change, of biodiversity loss, and of other changes in ecosystem structure and function. In California, annual grasses from Mediterranean Europe have nearly displaced native perennial grasses across the coastal hillsides and terraces of the state. Our study examines the impact of this invasion on carbon cycling and storage at two sites in northern coastal California. The results suggest that annual grass invasion has caused an average drop in soil carbon storage of 40 Mg/ha in the top half meter of soil, although additional mechanisms may also contribute to soil carbon losses. We attribute the reduction in soil carbon storage to low rates of net primary production in non-native annuals relative to perennial grasses, a shift in rooting depth and water use to primarily shallow sources, and soil respiratory losses in non-native grass soils that exceed production rates. These results indicate that even seemingly subtle land cover changes can significantly impact ecosystem functions in general, and carbon storage in particular.

  6. Adaptive responses to cool climate promotes persistence of a non-native lizard.

    Science.gov (United States)

    While, Geoffrey M; Williamson, Joseph; Prescott, Graham; Horváthová, Terézia; Fresnillo, Belén; Beeton, Nicholas J; Halliwell, Ben; Michaelides, Sozos; Uller, Tobias

    2015-03-22

    Successful establishment and range expansion of non-native species often require rapid accommodation of novel environments. Here, we use common-garden experiments to demonstrate parallel adaptive evolutionary response to a cool climate in populations of wall lizards (Podarcis muralis) introduced from southern Europe into England. Low soil temperatures in the introduced range delay hatching, which generates directional selection for a shorter incubation period. Non-native lizards from two separate lineages have responded to this selection by retaining their embryos for longer before oviposition--hence reducing the time needed to complete embryogenesis in the nest--and by an increased developmental rate at low temperatures. This divergence mirrors local adaptation across latitudes and altitudes within widely distributed species and suggests that evolutionary responses to climate can be very rapid. When extrapolated to soil temperatures encountered in nests within the introduced range, embryo retention and faster developmental rate result in one to several weeks earlier emergence compared with the ancestral state. We show that this difference translates into substantial survival benefits for offspring. This should promote short- and long-term persistence of non-native populations, and ultimately enable expansion into areas that would be unattainable with incubation duration representative of the native range.

  7. Identifying and ascribing the relative significance of introduction pathways for non-native plants into Iceland

    Directory of Open Access Journals (Sweden)

    Wasowicz Pawel

    2014-12-01

    Full Text Available The study is aimed at identifying pathways frequently used by non-native plant species, assessing their relative significance and development in time. Pathways were defined following NOBANIS framework (Madsen et al., 2014. Species assessments were based on HARMONIA scheme (Branquart, 2007. Four categories of environmental hazards were assessed plus two additional categories summarizing impacts on health and economy. Temporal development of pathways was assessed using cumulative per annum taxa records. To quantify the activity of investigated pathways over time an index (δ10 showing the number of new species introduced during the period of 10 years was calculated. The study shows that horticulture, landscaping and agriculture can be pointed out as pathways of concern in Iceland. A set of species of concern is also proposed. Two plant taxa are included in A list (high risk species: Anthriscus sylvestis and Lupinus nootkatensis. Three taxa are placed in B list (watch list: Heracleum mantegazzianum, Heracleum persicum and Pinus contorta. Results of the present study are compared with similar studies carried out in Denmark, Scandinavia and Baltic countries. Different measures to prevent introductions of new and potentially dangerous non-native species are also discussed including selection of good practices that may significantly reduce the threat from non-native species used in agriculture and horticulture.

  8. Non-native gobies facilitate the transmission of Bucephalus polymorphus (Trematoda).

    Science.gov (United States)

    Ondračková, Markéta; Hudcová, Iveta; Dávidová, Martina; Adámek, Zdeněk; Kašný, Martin; Jurajda, Pavel

    2015-07-19

    Introduced species can modify local host-parasite dynamics by amplifying parasite infection which can 'spill-back' to the native fauna, whether they are competent hosts for local parasites, or by acting as parasite sinks with 'dilution' of infection decreasing the parasite burden of native hosts. Recently infection by the trematode Bucephalus polymorphus has increased in several European rivers, being attributed to the introduction of intermediate host species from the Ponto-Caspian region. Using a combination of field and experimental data, we evaluated the competence of non-native and native fish as intermediate hosts for B. polymorphus and its role for parasite development in a definitive host. The density of 0+ juvenile fish (the second intermediate hosts for B. polymorphus) was measured in the River Morava, Czech Republic and fish were screened for natural metacercariae infection. The stomach contents of predatory fish that are definitive hosts of B. polymorphus were examined to assess the importance of non-native gobies for parasite transmission. In semi-natural conditions, parasite establishment, initial survival, and maturity rates in experimentally infected definitive hosts pikeperch Sander lucioperca were measured in flukes recovered from native white bream Abramis bjoerkna and non-native tubenose goby Proterorhinus semilunaris and round goby Neogobius melanostomus. Adult fluke size and egg production was also measured to evaluate the potential effect of intermediate host species on parasite fitness. We detected high natural infection parameters of B. polymorphus in native cyprinids and non-native gobies compared to data from the period prior to goby establishment. Both fish groups are consumed by predatory fish and represent a major component of the littoral fish community. Parasite establishment and adult size in definitive hosts was equivalent among the second intermediate host species, despite a lower size of metacercariae recovered from round gobies

  9. Wildlife species associated with non-coniferous vegetation in Pacific Northwest conifer forests: A review

    Science.gov (United States)

    Hagar, J.C.

    2007-01-01

    Non-coniferous vegetation, including herbs, shrubs, and broad-leaved trees, makes a vital contribution to ecosystem function and diversity in Pacific Northwest conifer forests. However, forest management has largely been indifferent or detrimental to shrubs and trees that have low commercial value, in spite of a paradigm shift towards more holistic management in recent decades. Forest management practices that are detrimental to broad-leaved trees and shrubs are likely to decrease habitat diversity for wildlife, but the number of species that may be affected has not previously been enumerated. I reviewed life history accounts for forest-dwelling vertebrate wildlife species and derived a list of 78 species in Oregon and Washington that are associated with non-coniferous vegetation. The diversity of direct and indirect food resources provided was the primary functional basis for associations of most species with non-coniferous vegetation. Thus, a diversity of herbs and broad-leaved trees and shrubs provides the foundation for food webs that contribute to diversity at multiple trophic levels in Pacific Northwest conifer forests. Given the number of species associated with non-coniferous vegetation in conifer-dominated forests, maintaining habitats that support diverse plant communities, particularly broad-leaved trees and shrubs, will be an important component of management strategies intended to foster biodiversity. Silvicultural practices such as modified planting densities, and pre-commercial and commercial thinning, can be used to control stand density in order to favor the development of understory herbs, shrubs, and a diversity of tree species within managed stands. Allowing shrubs and hardwood trees to develop and persist in early seral stands by curtailing vegetation control also would benefit many species associated with non-coniferous vegetation.

  10. Non-native fish control below Glen Canyon Dam - Report from a structured decision-making project

    Science.gov (United States)

    Runge, Michael C.; Bean, Ellen; Smith, David; Kokos, Sonja

    2011-01-01

    This report describes the results of a structured decision-making project by the U.S. Geological Survey to provide substantive input to the Bureau of Reclamation (Reclamation) for use in the preparation of an Environmental Assessment concerning control of non-native fish below Glen Canyon Dam. A forum was created to allow the diverse cooperating agencies and Tribes to discuss, expand, and articulate their respective values; to develop and evaluate a broad set of potential control alternatives using the best available science; and to define individual preferences of each group on how to manage the inherent trade-offs in this non-native fish control problem. This project consisted of two face-to-face workshops, held in Mesa, Arizona, October 18-20 and November 8-10, 2010. At the first workshop, a diverse set of objectives was discussed, which represented the range of concerns of those agencies and Tribes present. A set of non-native fish control alternatives ('hybrid portfolios') was also developed. Over the 2-week period between the two workshops, four assessment teams worked to evaluate the control alternatives against the array of objectives. At the second workshop, the results of the assessment teams were presented. Multi-criteria decision analysis methods were used to examine the trade-offs inherent in the problem, and allowed the participating agencies and Tribes to express their individual judgments about how those trade-offs should best be managed in Reclamation`s selection of a preferred alternative. A broad array of objectives was identified and defined, and an effort was made to understand how these objectives are likely to be achieved by a variety of strategies. In general, the objectives reflected desired future conditions over 30 years. A rich set of alternative approaches was developed, and the complex structure of those alternatives was documented. Multi-criteria decision analysis methods allowed the evaluation of those alternatives against the array

  11. Population size structure of non-native fishes along longitudinal gradients in a highly regulated Mediterranean basin.

    Directory of Open Access Journals (Sweden)

    Fátima Amat-Trigo

    2015-10-01

    Documented changes in fish size metrics at population levels can demonstrate trends in non-native fishes at basin scale, however, the collinearity with spatial gradients and the species-specific response could make it a difficult undertaking.

  12. Decoding speech perception by native and non-native speakers using single-trial electrophysiological data.

    Directory of Open Access Journals (Sweden)

    Alex Brandmeyer

    Full Text Available Brain-computer interfaces (BCIs are systems that use real-time analysis of neuroimaging data to determine the mental state of their user for purposes such as providing neurofeedback. Here, we investigate the feasibility of a BCI based on speech perception. Multivariate pattern classification methods were applied to single-trial EEG data collected during speech perception by native and non-native speakers. Two principal questions were asked: 1 Can differences in the perceived categories of pairs of phonemes be decoded at the single-trial level? 2 Can these same categorical differences be decoded across participants, within or between native-language groups? Results indicated that classification performance progressively increased with respect to the categorical status (within, boundary or across of the stimulus contrast, and was also influenced by the native language of individual participants. Classifier performance showed strong relationships with traditional event-related potential measures and behavioral responses. The results of the cross-participant analysis indicated an overall increase in average classifier performance when trained on data from all participants (native and non-native. A second cross-participant classifier trained only on data from native speakers led to an overall improvement in performance for native speakers, but a reduction in performance for non-native speakers. We also found that the native language of a given participant could be decoded on the basis of EEG data with accuracy above 80%. These results indicate that electrophysiological responses underlying speech perception can be decoded at the single-trial level, and that decoding performance systematically reflects graded changes in the responses related to the phonological status of the stimuli. This approach could be used in extensions of the BCI paradigm to support perceptual learning during second language acquisition.

  13. Effect of endophytic Bacillus cereus ERBP inoculation into non-native host: Potentials and challenges for airborne formaldehyde removal.

    Science.gov (United States)

    Khaksar, Gholamreza; Treesubsuntorn, Chairat; Thiravetyan, Paitip

    2016-10-01

    Phytoremediation could be a cost-effective, environmentally friendly approach for the treatment of indoor air. However, some drawbacks still dispute the expediency of phytotechnology. Our objectives were to investigate the competency of plant growth-promoting (PGP) endophytic Bacillus cereus ERBP (endophyte root blue pea), isolated from the root of Clitoria ternatea, to colonize and stabilize within Zamioculcas zamiifolia and Euphorbia milii as non-native hosts without causing any disease or stress symptoms. Moreover, the impact of B. cereus ERBP on the natural shoot endophytic community and for the airborne formaldehyde removal capability of non-native hosts was assessed. Non-native Z. zamiifolia was effectively inoculated with B. cereus ERBP through soil as the most efficient method of endophyte inoculation. Denaturing gradient gel electrophoresis profiling of the shoot endophytic community verified the colonization and stability of B. cereus ERBP within its non-native host during a 20-d fumigation period without interfering with the natural shoot endophytic diversity of Z. zamiifolia. B. cereus ERBP conferred full protection to its non-native host against formaldehyde phytotoxicity and enhanced airborne formaldehyde removal of Z. zamiifolia whereas non-inoculated plants suffered from formaldehyde phytotoxicity because their natural shoot endophytic community was detrimentally affected by formaldehyde. In contrast, B. cereus ERBP inoculation into non-native E. milii deteriorated airborne formaldehyde removal of the non-native host (compared to a non-inoculated one) as B. cereus ERBP interfered with natural shoot endophytic community of E. milii, which caused stress symptoms and stimulated ethylene biosynthesis. Non-native host inoculation with PGP B. cereus ERBP could bear potentials and challenges for airborne formaldehyde removal.

  14. Impact of non-native terrestrial mammals on the structure of the terrestrial mammal food web of Newfoundland, Canada.

    Directory of Open Access Journals (Sweden)

    Justin S Strong

    Full Text Available The island of Newfoundland is unique because it has as many non-native terrestrial mammals as native ones. The impacts of non-native species on native flora and fauna can be profound and invasive species have been identified as one of the primary drivers of species extinction. Few studies, however, have investigated the effects of a non-native species assemblage on community and ecosystem properties. We reviewed the literature to build the first terrestrial mammal food web for the island of Newfoundland and then used network analyses to investigate how the timing of introductions and trophic position of non-native species has affected the structure of the terrestrial mammal food web in Newfoundland. The first non-native mammals (house mouse and brown rat became established in Newfoundland with human settlement in the late 15th and early 16th centuries. Coyotes and southern red-backed voles are the most recent mammals to establish themselves on the island in 1985 and 1998, respectively. The fraction of intermediate species increased with the addition of non-native mammals over time whereas the fraction of basal and top species declined over time. This increase in intermediate species mediated by non-native species arrivals led to an overall increase in the terrestrial mammal food web connectance and generality (i.e. mean number of prey per predator. This diverse prey base and sources of carrion may have facilitated the natural establishment of coyotes on the island. Also, there is some evidence that the introduction of non-native prey species such as the southern red-backed vole has contributed to the recovery of the threatened American marten. Long-term monitoring of the food web is required to understand and predict the impacts of the diverse novel interactions that are developing in the terrestrial mammal food web of Newfoundland.

  15. Is my stress right or wrong? Studying the production of stress by non-native speaking teachers of English

    OpenAIRE

    Ika Apriani Fata

    2014-01-01

    This study aims at exploring the production of stress by non native English teachers in Aceh. It also inquires into how these teachers of English overcame their shortcomings in oral English language teaching. 45 non native English teachers from Aceh were recorded. They came from four regions in the province of Aceh, namely Aceh Timur, Langsa, Aceh Utara and Aceh Besar. The participants have taught English from five to 15 years. The approach used in this paper is qualitative by focusing on the...

  16. Impact of non-native terrestrial mammals on the structure of the terrestrial mammal food web of Newfoundland, Canada.

    Science.gov (United States)

    Strong, Justin S; Leroux, Shawn J

    2014-01-01

    The island of Newfoundland is unique because it has as many non-native terrestrial mammals as native ones. The impacts of non-native species on native flora and fauna can be profound and invasive species have been identified as one of the primary drivers of species extinction. Few studies, however, have investigated the effects of a non-native species assemblage on community and ecosystem properties. We reviewed the literature to build the first terrestrial mammal food web for the island of Newfoundland and then used network analyses to investigate how the timing of introductions and trophic position of non-native species has affected the structure of the terrestrial mammal food web in Newfoundland. The first non-native mammals (house mouse and brown rat) became established in Newfoundland with human settlement in the late 15th and early 16th centuries. Coyotes and southern red-backed voles are the most recent mammals to establish themselves on the island in 1985 and 1998, respectively. The fraction of intermediate species increased with the addition of non-native mammals over time whereas the fraction of basal and top species declined over time. This increase in intermediate species mediated by non-native species arrivals led to an overall increase in the terrestrial mammal food web connectance and generality (i.e. mean number of prey per predator). This diverse prey base and sources of carrion may have facilitated the natural establishment of coyotes on the island. Also, there is some evidence that the introduction of non-native prey species such as the southern red-backed vole has contributed to the recovery of the threatened American marten. Long-term monitoring of the food web is required to understand and predict the impacts of the diverse novel interactions that are developing in the terrestrial mammal food web of Newfoundland.

  17. Reproduction of the non-native fish Lepomis gibbosus (Perciformes: Centrarchidae) in Brazil.

    Science.gov (United States)

    Santos, Rangel E; Silva, Tayara P; Chehayeb, Igor V; de Magalhães, André L B

    2012-09-01

    Minas Gerais is the fourth largest Brazilian state, and has an estimate of 354 native fish species. However, these fish species may be threatened, as this state has the highest rank of fish introductions reported for Brazil and South America. As one from the total of 85 non-native species detected, Lepomis gibbosus was introduced in the 60s to serve both as foragefish and to improve sport fishing. In this study, we evaluated the establishment of L. gibbosus in a shallow lake in the city ofOuro Preto, Doce River basin, state of Minas Gerais, Southeastern Brazil. We collected fish with fishing rods every two months from March 2002-February 2003. Fragments of gonads from a total of 226 females and 226 males were obtained and processed following standard histological techniques; then 5-7 microm thickness sections were taken and stained in hematoxylin-eosin. Besides, for each specimen, the biometric measurements included the standard length (SL) and body weight (BW); and the sex ratio was obtained. The reproductive cycle stages were confirmed by the distribution of oocytes and spermatogenic cells. The type of spawning was determined by the frequency distribution of the reproductive cycle stages and ovarian histology. Based on the microscopic characteristics of the gonads, the following stages of the reproductive cycle were determined: one=Rest, two=Mature, three=Spawned for females or Spent for males; males and females in reproduction were found throughout the study period. Post-spawned ovaries containing oocytes in stages one (initial perinucleolar), two (advanced perinucleolar), three (pre-vitellogenic), four (vitellogenic) and post-ovulatory follicles indicated fractionated-type spawning in this species. The smallest breeding male and female measured were 4.6 and 4.9cm standard length, respectively, suggesting stunting. The sex ratio did not vary between males and females along the year and bimonthly, being 1:1. Moreover, L. gibbosus appears to be at stage three of

  18. Phonetic processing of non-native speech in semantic vs non-semantic tasks.

    Science.gov (United States)

    Gustafson, Erin; Engstler, Caroline; Goldrick, Matthew

    2013-12-01

    Research with speakers with acquired production difficulties has suggested phonetic processing is more difficult in tasks that require semantic processing. The current research examined whether similar effects are found in bilingual phonetic processing. English-French bilinguals' productions in picture naming (which requires semantic processing) were compared to those elicited by repetition (which does not require semantic processing). Picture naming elicited slower, more accented speech than repetition. These results provide additional support for theories integrating cognitive and phonetic processes in speech production and suggest that bilingual speech research must take cognitive factors into account when assessing the structure of non-native sound systems.

  19. Overview of Native-speaker English Teacher Versus Non-native-speaker English Teacher

    Institute of Scientific and Technical Information of China (English)

    ZOU Xu

    2015-01-01

    As much more non-native-speaker English teachers teach alongside native-speaker English teachers, either in China or any other non-English-speaking country, research on the differences between native-speaker English teacher and non-na⁃tive-speaker English teacher is necessary. This paper offers an overview of such difference between the two groups of English teachers in terms of their strengths and weaknesses, teaching styles and approaches. The conclusion suggests that cooperation and communication be emphsised and that the two groups of teachers communicate more and exchange their ideas on how to teach the same group of students more effectively.

  20. How noise and language proficiency influence speech recognition by individual non-native listeners.

    Science.gov (United States)

    Zhang, Jin; Xie, Lingli; Li, Yongjun; Chatterjee, Monita; Ding, Nai

    2014-01-01

    This study investigated how speech recognition in noise is affected by language proficiency for individual non-native speakers. The recognition of English and Chinese sentences was measured as a function of the signal-to-noise ratio (SNR) in sixty native Chinese speakers who never lived in an English-speaking environment. The recognition score for speech in quiet (which varied from 15%-92%) was found to be uncorrelated with speech recognition threshold (SRTQ/2), i.e. the SNR at which the recognition score drops to 50% of the recognition score in quiet. This result demonstrates separable contributions of language proficiency and auditory processing to speech recognition in noise.

  1. A global organism detection and monitoring system for non-native species

    Science.gov (United States)

    Graham, J.; Newman, G.; Jarnevich, C.; Shory, R.; Stohlgren, T.J.

    2007-01-01

    Harmful invasive non-native species are a significant threat to native species and ecosystems, and the costs associated with non-native species in the United States is estimated at over $120 Billion/year. While some local or regional databases exist for some taxonomic groups, there are no effective geographic databases designed to detect and monitor all species of non-native plants, animals, and pathogens. We developed a web-based solution called the Global Organism Detection and Monitoring (GODM) system to provide real-time data from a broad spectrum of users on the distribution and abundance of non-native species, including attributes of their habitats for predictive spatial modeling of current and potential distributions. The four major subsystems of GODM provide dynamic links between the organism data, web pages, spatial data, and modeling capabilities. The core survey database tables for recording invasive species survey data are organized into three categories: "Where, Who & When, and What." Organisms are identified with Taxonomic Serial Numbers from the Integrated Taxonomic Information System. To allow users to immediately see a map of their data combined with other user's data, a custom geographic information system (GIS) Internet solution was required. The GIS solution provides an unprecedented level of flexibility in database access, allowing users to display maps of invasive species distributions or abundances based on various criteria including taxonomic classification (i.e., phylum or division, order, class, family, genus, species, subspecies, and variety), a specific project, a range of dates, and a range of attributes (percent cover, age, height, sex, weight). This is a significant paradigm shift from "map servers" to true Internet-based GIS solutions. The remainder of the system was created with a mix of commercial products, open source software, and custom software. Custom GIS libraries were created where required for processing large datasets

  2. Across-talker effects on non-native listeners’ vowel perception in noise1

    OpenAIRE

    Bent, Tessa; Kewley-Port, Diane; Ferguson, Sarah Hargus

    2010-01-01

    This study explored how across-talker differences influence non-native vowel perception. American English (AE) and Korean listeners were presented with recordings of 10 AE vowels in ∕bVd∕ context. The stimuli were mixed with noise and presented for identification in a 10-alternative forced-choice task. The two listener groups heard recordings of the vowels produced by 10 talkers at three signal-to-noise ratios. Overall the AE listeners identified the vowels 22% more accurately than the Korean...

  3. Impact of Non-Native Birds on Native Ecosystems: A Global Analysis.

    Science.gov (United States)

    Martin-Albarracin, Valeria L; Amico, Guillermo C; Simberloff, Daniel; Nuñez, Martin A

    2015-01-01

    Introduction and naturalization of non-native species is one of the most important threats to global biodiversity. Birds have been widely introduced worldwide, but their impacts on populations, communities, and ecosystems have not received as much attention as those of other groups. This work is a global synthesis of the impact of nonnative birds on native ecosystems to determine (1) what groups, impacts, and locations have been best studied; (2) which taxonomic groups and which impacts have greatest effects on ecosystems, (3) how important are bird impacts at the community and ecosystem levels, and (4) what are the known benefits of nonnative birds to natural ecosystems. We conducted an extensive literature search that yielded 148 articles covering 39 species belonging to 18 families -18% of all known naturalized species. Studies were classified according to where they were conducted: Africa, Asia, Australasia, Europe, North America, South America, Islands of the Indian, of the Pacific, and of the Atlantic Ocean. Seven types of impact on native ecosystems were evaluated: competition, disease transmission, chemical, physical, or structural impact on ecosystem, grazing/ herbivory/ browsing, hybridization, predation, and interaction with other non-native species. Hybridization and disease transmission were the most important impacts, affecting the population and community levels. Ecosystem-level impacts, such as structural and chemical impacts were detected. Seven species were found to have positive impacts aside from negative ones. We provide suggestions for future studies focused on mechanisms of impact, regions, and understudied taxonomic groups.

  4. Adaptive Communication: Languages with More Non-Native Speakers Tend to Have Fewer Word Forms

    Science.gov (United States)

    Bentz, Christian; Verkerk, Annemarie; Kiela, Douwe; Hill, Felix; Buttery, Paula

    2015-01-01

    Explaining the diversity of languages across the world is one of the central aims of typological, historical, and evolutionary linguistics. We consider the effect of language contact-the number of non-native speakers a language has-on the way languages change and evolve. By analysing hundreds of languages within and across language families, regions, and text types, we show that languages with greater levels of contact typically employ fewer word forms to encode the same information content (a property we refer to as lexical diversity). Based on three types of statistical analyses, we demonstrate that this variance can in part be explained by the impact of non-native speakers on information encoding strategies. Finally, we argue that languages are information encoding systems shaped by the varying needs of their speakers. Language evolution and change should be modeled as the co-evolution of multiple intertwined adaptive systems: On one hand, the structure of human societies and human learning capabilities, and on the other, the structure of language. PMID:26083380

  5. Optimizing Automatic Speech Recognition for Low-Proficient Non-Native Speakers

    Directory of Open Access Journals (Sweden)

    Catia Cucchiarini

    2010-01-01

    Full Text Available Computer-Assisted Language Learning (CALL applications for improving the oral skills of low-proficient learners have to cope with non-native speech that is particularly challenging. Since unconstrained non-native ASR is still problematic, a possible solution is to elicit constrained responses from the learners. In this paper, we describe experiments aimed at selecting utterances from lists of responses. The first experiment on utterance selection indicates that the decoding process can be improved by optimizing the language model and the acoustic models, thus reducing the utterance error rate from 29–26% to 10–8%. Since giving feedback on incorrectly recognized utterances is confusing, we verify the correctness of the utterance before providing feedback. The results of the second experiment on utterance verification indicate that combining duration-related features with a likelihood ratio (LR yield an equal error rate (EER of 10.3%, which is significantly better than the EER for the other measures in isolation.

  6. Adaptive Communication: Languages with More Non-Native Speakers Tend to Have Fewer Word Forms.

    Science.gov (United States)

    Bentz, Christian; Verkerk, Annemarie; Kiela, Douwe; Hill, Felix; Buttery, Paula

    2015-01-01

    Explaining the diversity of languages across the world is one of the central aims of typological, historical, and evolutionary linguistics. We consider the effect of language contact-the number of non-native speakers a language has-on the way languages change and evolve. By analysing hundreds of languages within and across language families, regions, and text types, we show that languages with greater levels of contact typically employ fewer word forms to encode the same information content (a property we refer to as lexical diversity). Based on three types of statistical analyses, we demonstrate that this variance can in part be explained by the impact of non-native speakers on information encoding strategies. Finally, we argue that languages are information encoding systems shaped by the varying needs of their speakers. Language evolution and change should be modeled as the co-evolution of multiple intertwined adaptive systems: On one hand, the structure of human societies and human learning capabilities, and on the other, the structure of language.

  7. Disadvantages of publishing biomedical research articles in English for non-native speakers of English.

    Science.gov (United States)

    Rezaeian, Mohsen

    2015-01-01

    English has become the most frequently used language for scientific communication in the biomedical field. Therefore, scholars from all over the world try to publish their findings in English. This trend has a number of advantages, along with several disadvantages. In the current article, the most important disadvantages of publishing biomedical research articles in English for non-native speakers of English are reviewed. The most important disadvantages of publishing biomedical research articles in English for non-native speakers may include: Overlooking, either unintentionally or even deliberately, the most important local health problems; failure to carry out groundbreaking research due to limited medical research budgets; violating generally accepted codes of publication ethics and committing research misconduct and publications in open-access scam/predatory journals rather than prestigious journals. The above mentioned disadvantages could eventually result in academic establishments becoming irresponsible or, even worse, corrupt. In order to avoid this, scientists, scientific organizations, academic institutions, and scientific associations all over the world should design and implement a wider range of collaborative and comprehensive plans.

  8. The relationship between brain reaction and English reading tests for non-native English speakers.

    Science.gov (United States)

    Cheng, Pei-Wen; Tian, Yu-Jie; Kuo, Ting-Hua; Sun, Koun-Tem

    2016-07-01

    This research analyzed the brain activity of non-native English speakers while engaged in English reading tests. The brain wave event-related potentials (ERPs) of participants were used to analyze the difference between making correct and incorrect choices on English reading test items. Three English reading tests of differing levels were designed and 20 participants, 10 males and 10 females whose ages ranged from 20 to 24, voluntarily participated in the experiment. Experimental results were analyzed by performing independent t-tests on the ERPs of participants for gender, difficulty level, and correct versus wrong options. Participants who chose incorrect options elicited a larger N600, verifying results found in the literature. Another interesting result was found: For incorrectly answered items, different areas of brain showing a significant difference in ERPs between the chosen and non-chosen options corresponded to gender differences; for males, this area was located in the right hemisphere whereas for females, it was located in the left. Experimental results imply that non-native English speaking males and females employ different areas of the brain to comprehend the meaning of difficult items.

  9. Quantifying the intelligibility of speech in noise for non-native talkers

    Science.gov (United States)

    van Wijngaarden, Sander J.; Steeneken, Herman J. M.; Houtgast, Tammo

    2002-12-01

    The intelligibility of speech pronounced by non-native talkers is generally lower than speech pronounced by native talkers, especially under adverse conditions, such as high levels of background noise. The effect of foreign accent on speech intelligibility was investigated quantitatively through a series of experiments involving voices of 15 talkers, differing in language background, age of second-language (L2) acquisition and experience with the target language (Dutch). Overall speech intelligibility of L2 talkers in noise is predicted with a reasonable accuracy from accent ratings by native listeners, as well as from the self-ratings for proficiency of L2 talkers. For non-native speech, unlike native speech, the intelligibility of short messages (sentences) cannot be fully predicted by phoneme-based intelligibility tests. Although incorrect recognition of specific phonemes certainly occurs as a result of foreign accent, the effect of reduced phoneme recognition on the intelligibility of sentences may range from severe to virtually absent, depending on (for instance) the speech-to-noise ratio. Objective acoustic-phonetic analyses of accented speech were also carried out, but satisfactory overall predictions of speech intelligibility could not be obtained with relatively simple acoustic-phonetic measures.

  10. Across-talker effects on non-native listeners' vowel perception in noise.

    Science.gov (United States)

    Bent, Tessa; Kewley-Port, Diane; Ferguson, Sarah Hargus

    2010-11-01

    This study explored how across-talker differences influence non-native vowel perception. American English (AE) and Korean listeners were presented with recordings of 10 AE vowels in /bVd/ context. The stimuli were mixed with noise and presented for identification in a 10-alternative forced-choice task. The two listener groups heard recordings of the vowels produced by 10 talkers at three signal-to-noise ratios. Overall the AE listeners identified the vowels 22% more accurately than the Korean listeners. There was a wide range of identification accuracy scores across talkers for both AE and Korean listeners. At each signal-to-noise ratio, the across-talker intelligibility scores were highly correlated for AE and Korean listeners. Acoustic analysis was conducted for 2 vowel pairs that exhibited variable accuracy across talkers for Korean listeners but high identification accuracy for AE listeners. Results demonstrated that Korean listeners' error patterns for these four vowels were strongly influenced by variability in vowel production that was within the normal range for AE talkers. These results suggest that non-native listeners are strongly influenced by across-talker variability perhaps because of the difficulty they have forming native-like vowel categories.

  11. Vegetation and non-native ungulate monitoring at the Big Island National Wildlife Refuge Complex 2010–2014.

    Science.gov (United States)

    Hess, Steven C.; Leopold, Christina R.; Kendall, Steven J.

    2015-01-01

    The Hakalau Forest Unit (HFU) of Big Island National Wildlife Refuge Complex (BINWRC) has intensively managed feral cattle (Bos taurus) and pigs (Sus scrofa) and monitored non-native ungulate presence and distribution during surveys of all managed areas since 1988. We: 1) provide results from recent ungulate surveys at HFU to determine current feral pig abundance and distribution; 2) present results of surveys of ungulate presence and distribution at the Kona Forest Unit (KFU); 3) present results of surveys of weed presence and cover at both refuge units; and 4) present baseline results from long-term vegetation monitoring plots at KFU. Overall pig abundance appears to have decreased at HFU, although not significantly, over the period from 2010 to 2014. Management units 2 and 4 contained the majority of pigs at HFU. Pig density outside of adjacent managed areas has declined significantly from 2010 to 2014 for unknown reasons. Ungulate sign occurred in > 50% of plots at KFU during the November 2012 and September 2013 surveys, but ungulate sign occurred in temporal pattern. Spatial patterns are more pronounced; however, some weed species may not be reliably represented due to observers’ abilities to recognize less common weeds. Nonetheless, the distribution and cover of fireweed (Senecio madagascariensis) at KFU may have increased over the study period. Vegetation surveys documented baseline floristic composition and forest structure at KFU. It is not known if this current amount of emerging cover is sufficient for long-term self-sustaining forest canopy regeneration; however, numerous ‘ōhi‘a seedlings were found in the wet forest and mesic ‘ōhi‘a habitats, indicating an ample viable seed source and robust potential for forest regeneration.

  12. Some linguistic and pragmatic considerations affecting science reporting in English by non-native speakers of the language.

    Science.gov (United States)

    Kourilova-Urbanczik, Magda

    2012-06-01

    Approximately 50% of publications in English peer reviewed journals are contributed by non-native speakers (NNS) of the language. Basic thought processes are considered to be universal yet there are differences in thought patterns and particularly in discourse management of writers with different linguistic and cultural backgrounds. The study highlights some areas of potential incompatibility in native and NNS processing of English scientific papers. Principles and conventions in generating academic discourse are considered in terms of frequently occurring failures of NNS to meet expectations of editors, reviewers, and readers. Major problem areas concern organization and flow of information, principles of cohesion and clarity, cultural constraints, especially those of politeness and negotiability of ideas, and the complicated area of English modality pragmatics. The aim of the paper is to sensitize NN authors of English academic reports to problem areas of discourse processing which are stumbling blocks, often affecting acceptance of manuscripts. The problems discussed are essential for acquiring pragmalinguistic and sociocultural competence in producing effective communication.

  13. Mental health status in pregnancy among native and non-native Swedish-speaking women: a Bidens study.

    Science.gov (United States)

    Wangel, Anne-Marie; Schei, Berit; Ryding, Elsa Lena; Ostman, Margareta

    2012-12-01

    To describe mental health status in native and non-native Swedish-speaking pregnant women and explore risk factors of depression and posttraumatic stress (PTS) symptoms. A cross-sectional questionnaire study was conducted at midwife-based antenatal clinics in Southern Sweden. A non-selected group of women in mid-pregnancy. Participants completed a questionnaire covering background characteristics, social support, life events, mental health variables and the short Edinburgh Depression Scale. Depressive symptoms during the past week and PTS symptoms during the past year. Out of 1003 women, 21.4% reported another language than Swedish as their mother tongue and were defined as non-native. These women were more likely to be younger, have fewer years of education, potential financial problems, and lack of social support. More non-native speakers self-reported depressive, PTS, anxiety and, psychosomatic symptoms, and fewer had had consultations with a psychiatrist or psychologist. Of all women, 13.8% had depressive symptoms defined by Edinburgh Depression Scale 7 or above. Non-native status was associated with statistically increased risks of depressive symptoms and having ≥1 PTS symptom compared with native-speaking women. Multivariate modeling including all selected factors resulted in adjusted odds ratios for depressive symptoms of 1.75 (95% confidence interval: 1.11-2.76) and of 1.56 (95% confidence interval: 1.10-2.34) for PTS symptoms in non-native Swedish speakers. Non-native Swedish-speaking women had a more unfavorable mental health status than native speakers. In spite of this, non-native speaking women had sought less mental health care. © 2012 The Authors Acta Obstetricia et Gynecologica Scandinavica© 2012 Nordic Federation of Societies of Obstetrics and Gynecology.

  14. Modulation of legume defense signaling pathways by native and non-native pea aphid clones

    Directory of Open Access Journals (Sweden)

    Carlos Sanchez-Arcos

    2016-12-01

    Full Text Available The pea aphid (Acyrthosiphon pisum is a complex of at least 15 genetically different host races that are native to specific legume plants, but can all develop on the universal host plant Vicia faba. Despite much research it is still unclear why pea aphid host races (biotypes are able to colonize their native hosts while other host races are not. All aphids penetrate the plant and salivate into plant cells when they test plant suitability. Thus plants might react differently to the various pea aphid host races. To find out whether legume species vary in their defense responses to different pea aphid host races, we measured the amounts of salicylic acid (SA, the jasmonic acid-isoleucine conjugate (JA-Ile, other jasmonate precursors and derivatives, and abscisic acid (ABA in four different species (Medicago sativa, Trifolium pratense, Pisum sativum, V. faba after infestation by native and non-native pea aphid clones of various host races. Additionally, we assessed the performance of the clones on the four plant species. On M. sativa and T. pratense, non-native clones that were barely able to survive or reproduce, triggered a strong SA and JA-Ile response, whereas infestation with native clones led to lower levels of both phytohormones. On P. sativum, non-native clones, which survived or reproduced to a certain extent, induced fluctuating SA and JA-Ile levels, whereas the native clone triggered only a weak SA and JA-Ile response. On the universal host V. faba all aphid clones triggered only low SA levels initially, but induced clone-specific patterns of SA and JA-Ile later on. The levels of the active JA-Ile conjugate and of the other JA-pathway metabolites measured showed in many cases similar patterns, suggesting that the reduction in JA signaling was due to an effect upstream of OPDA. ABA levels were downregulated in all aphid clone-plant combinations and were therefore probably not decisive factors for aphid-plant compatibility. Our results

  15. Introduction of non-native marine fish species to the Canary Islands waters through oil platforms as vectors

    Science.gov (United States)

    Pajuelo, José G.; González, José A.; Triay-Portella, Raül; Martín, José A.; Ruiz-Díaz, Raquel; Lorenzo, José M.; Luque, Ángel

    2016-11-01

    This work documents the introduction of non-native fish species to the Canary Islands (central-eastern Atlantic) through oil rigs. Methodological approaches have included surveys by underwater visual censuses around and under oil platforms and along the docking area of rigs at the Port of Las Palmas. Eleven non-native fish species were registered. Paranthias furcifer, Abudefduf hoefleri, Acanthurus bahianus, Acanthurus chirurgus, and Acanthurus coeruleus are first recorded from the Canaries herein. Other three species could not be identified, although they have never been observed in the Canaries. Cephalopholis taeniops, Abudefduf saxatilis, and Acanthurus monroviae had been previously recorded. Native areas of these species coincide with the areas of origin and the scale of oil rigs with destination the Port of Las Palmas. The absence of native species in the censuses at rigs and their presence at rigs docking area, together with the observation of non-native species after the departure of platforms, reject the possibility that these non-native species were already present in the area introduced by another vector. C. taeniops, A. hoefleri, A. saxatilis, A. chirurgus, A. coeruleus and A. monroviae are clearly seafarer species. A. bahianus seems to be a potential seafarer species. P. furcifer is a castaway species. For the moment, the number of individuals of the non-native species in marine ecosystems of the Canaries seems to be low, and more investigation is needed for controlling these translocations.

  16. Durations of American English vowels by native and non-native speakers: acoustic analyses and perceptual effects.

    Science.gov (United States)

    Liu, Chang; Jin, Su-Hyun; Chen, Chia-Tsen

    2014-06-01

    The goal of this study was to examine durations of American English vowels produced by English-, Chinese-, and Korean-native speakers and the effects of vowel duration on vowel intelligibility. Twelve American English vowels were recorded in the /hVd/ phonetic context by native speakers and non-native speakers. The English vowel duration patterns as a function of vowel produced by non-native speakers were generally similar to those produced by native speakers. These results imply that using duration differences across vowels may be an important strategy for non-native speakers' production before they are able to employ spectral cues to produce and perceive English speech sounds. In the intelligibility experiment, vowels were selected from 10 native and non-native speakers and vowel durations were equalized at 170 ms. Intelligibility of vowels with original and equalized durations was evaluated by American English native listeners. Results suggested that vowel intelligibility of native and non-native speakers degraded slightly by 3-8% when durations were equalized, indicating that vowel duration plays a minor role in vowel intelligibility.

  17. Phytophagous insects on native and non-native host plants: combining the community approach and the biogeographical approach.

    Directory of Open Access Journals (Sweden)

    Kim Meijer

    Full Text Available During the past centuries, humans have introduced many plant species in areas where they do not naturally occur. Some of these species establish populations and in some cases become invasive, causing economic and ecological damage. Which factors determine the success of non-native plants is still incompletely understood, but the absence of natural enemies in the invaded area (Enemy Release Hypothesis; ERH is one of the most popular explanations. One of the predictions of the ERH, a reduced herbivore load on non-native plants compared with native ones, has been repeatedly tested. However, many studies have either used a community approach (sampling from native and non-native species in the same community or a biogeographical approach (sampling from the same plant species in areas where it is native and where it is non-native. Either method can sometimes lead to inconclusive results. To resolve this, we here add to the small number of studies that combine both approaches. We do so in a single study of insect herbivory on 47 woody plant species (trees, shrubs, and vines in the Netherlands and Japan. We find higher herbivore diversity, higher herbivore load and more herbivory on native plants than on non-native plants, generating support for the enemy release hypothesis.

  18. The Spread of Non-native Plant Species Collection of Cibodas Botanical Garden into Mt. Gede Pangrango National Park

    Directory of Open Access Journals (Sweden)

    Musyarofah Zuhri

    2013-05-01

    Full Text Available The role of botanic garden in spread of non-native plant species has concerned of international worldwide. This study aimed to study the extent of non-native plant species from Cibodas Botanical Garden (CBG which invades into natural rainforest. A line transect was made edge-to-interior with 1,600 m in distance from CBG boundary. Result showed that distance from CBG was not significant in correlation with non-native tree and treelet density. Furthermore, presence of existing CBG’s plant collection was not a single aspect which influenced presence and abundance. Three invasive species possibly was escape from CBG and it showed edge-to-interior in stems density, i.e. Cinchona pubescens, Calliandra calothyrsus and Cestrum aurantiacum. The patterns of non-native species were influenced by presence of ditch across transect, existence of human trail, and the other non-native species did not have general pattern of spread distribution. Overall, botanical gardens should minimize the risk of unintentional introduced plant by perform site-specific risk assessment.

  19. Learning foreign sounds in an alien world: videogame training improves non-native speech categorization.

    Science.gov (United States)

    Lim, Sung-joo; Holt, Lori L

    2011-01-01

    Although speech categories are defined by multiple acoustic dimensions, some are perceptually weighted more than others and there are residual effects of native-language weightings in non-native speech perception. Recent research on nonlinguistic sound category learning suggests that the distribution characteristics of experienced sounds influence perceptual cue weights: Increasing variability across a dimension leads listeners to rely upon it less in subsequent category learning (Holt & Lotto, 2006). The present experiment investigated the implications of this among native Japanese learning English /r/-/l/ categories. Training was accomplished using a videogame paradigm that emphasizes associations among sound categories, visual information, and players' responses to videogame characters rather than overt categorization or explicit feedback. Subjects who played the game for 2.5h across 5 days exhibited improvements in /r/-/l/ perception on par with 2-4 weeks of explicit categorization training in previous research and exhibited a shift toward more native-like perceptual cue weights.

  20. A Multidimensional Scaling Study of Native and Non-Native Listeners' Perception of Second Language Speech.

    Science.gov (United States)

    Foote, Jennifer A; Trofimovich, Pavel

    2016-04-01

    Second language speech learning is predicated on learners' ability to notice differences between their own language output and that of their interlocutors. Because many learners interact primarily with other second language users, it is crucial to understand which dimensions underlie the perception of second language speech by learners, compared to native speakers. For this study, 15 non-native and 10 native English speakers rated 30-s language audio-recordings from controlled reading and interview tasks for dissimilarity, using all pairwise combinations of recordings. PROXSCAL multidimensional scaling analyses revealed fluency and aspects of speakers' pronunciation as components underlying listener judgments but showed little agreement across listeners. Results contribute to an understanding of why second language speech learning is difficult and provide implications for language training.

  1. Recognizing Chinese characters in digital ink from non-native language writers using hierarchical models

    Science.gov (United States)

    Bai, Hao; Zhang, Xi-wen

    2017-06-01

    While Chinese is learned as a second language, its characters are taught step by step from their strokes to components, radicals to components, and their complex relations. Chinese Characters in digital ink from non-native language writers are deformed seriously, thus the global recognition approaches are poorer. So a progressive approach from bottom to top is presented based on hierarchical models. Hierarchical information includes strokes and hierarchical components. Each Chinese character is modeled as a hierarchical tree. Strokes in one Chinese characters in digital ink are classified with Hidden Markov Models and concatenated to the stroke symbol sequence. And then the structure of components in one ink character is extracted. According to the extraction result and the stroke symbol sequence, candidate characters are traversed and scored. Finally, the recognition candidate results are listed by descending. The method of this paper is validated by testing 19815 copies of the handwriting Chinese characters written by foreign students.

  2. Reproduction of the non-native fish Lepomis gibbosus (Perciformes: Centrarchidae in Brazil

    Directory of Open Access Journals (Sweden)

    Rangel E. Santos

    2012-09-01

    Full Text Available Minas Gerais is the fourth largest Brazilian state, and has an estimate of 354 native fish species. However, these fish species may be threatened, as this state has the highest rank of fish introductions reported for Brazil and South America. As one from the total of 85 non-native species detected, Lepomis gibbosus was introduced in the 60s to serve both as foragefish and to improve sport fishing. In this study, we evaluated the establishment of L. gibbosus in a shallow lake in the city of Ouro Preto, Doce River basin, state of Minas Gerais, Southeastern Brazil. We collected fish with fishing rods every two months from March 2002-February 2003. Fragments of gonads from a total of 226 females and 226 males were obtained and processed following standard histological techniques; then 5-7μm thickness sections were taken and stained in hematoxylin-eosin. Besides, for each specimen, the biometric measurements included the standard length (SL and body weight (BW; and the sex ratio was obtained. The reproductive cycle stages were confirmed by the distribution of oocytes and spermatogenic cells. The type of spawning was determined by the frequency distribution of the reproductive cycle stages and ovarian histology. Based on the microscopic characteristics of the gonads, the following stages of the reproductive cycle were determined: one=Rest, two=Mature, three=Spawned for females or Spent for males; males and females in reproduction were found throughout the study period. Post-spawned ovaries containing oocytes in stages one (initial perinucleolar, two (advanced perinucleolar, three (pre-vitellogenic, four (vitellogenic and post-ovulatory follicles indicated fractionated-type spawning in this species. The smallest breeding male and female measured were 4.6 and 4.9cm standard length, respectively, suggesting stunting. The sex ratio did not vary between males and females along the year and bimonthly, being 1:1. Moreover, L. gibbosus appears to be at stage

  3. Assessing the impact of non-native freshwater fishes on native species using relative weight

    Directory of Open Access Journals (Sweden)

    Giannetto D.

    2012-01-01

    Full Text Available The aim of the research was to test relative weight (Wr, a condition index which allows evaluation of fish well-being, as a tool to investigate the impact of the presence of non native species (NNS on the condition of the key native species (NS of the Tiber River basin (Italy: Barbustyberinus Bonaparte, Leuciscus cephalus (Linnaeus, Leuciscus lucumonis Bianco, Rutilus rubilio (Bonaparte and Telestes muticellus (Bonaparte. By means of Canonical Correlation Analysis, data from 130 sampling sites, distributed throughout Tiber River basin, were examined. Wr of NS was related to densities of NNS and to environmental variables. Moreover, the correlation between Wr of NS and density of NNS was investigated through linear regression analysis and covariance analysis. Preliminary results encourage the use of Wr as a tool to assess the relationship between NS and ecological factors (such as the presence of NNS and to explain the changes that occur along the longitudinal gradient of a river.

  4. Non-Native Ambrosia Beetles as Opportunistic Exploiters of Living but Weakened Trees

    Science.gov (United States)

    Ranger, Christopher M.; Schultz, Peter B.; Frank, Steven D.; Chong, Juang H.; Reding, Michael E.

    2015-01-01

    Exotic Xylosandrus spp. ambrosia beetles established in non-native habitats have been associated with sudden and extensive attacks on a diverse range of living trees, but factors driving their shift from dying/dead hosts to living and healthy ones are not well understood. We sought to characterize the role of host physiological condition on preference and colonization by two invaders, Xylosandrus germanus and Xylosandrus crassiusculus. When given free-choice under field conditions among flooded and non-flooded deciduous tree species of varying intolerance to flooding, beetles attacked flood-intolerant tree species over more tolerant species within 3 days of initiating flood stress. In particular, flood-intolerant flowering dogwood (Cornus florida) sustained more attacks than flood-tolerant species, including silver maple (Acer saccharinum) and swamp white oak (Quercus bicolor). Ethanol, a key host-derived attractant, was detected at higher concentrations 3 days after initiating flooding within stems of flood intolerant species compared to tolerant and non-flooded species. A positive correlation was also detected between ethanol concentrations in stem tissue and cumulative ambrosia beetle attacks. When adult X. germanus and X. crassiusculus were confined with no-choice to stems of flood-stressed and non-flooded C. florida, more ejected sawdust resulting from tunneling activity was associated with the flood-stressed trees. Furthermore, living foundresses, eggs, larvae, and pupae were only detected within galleries created in stems of flood-stressed trees. Despite a capability to attack diverse tree genera, X. germanus and X. crassiusculus efficiently distinguished among varying host qualities and preferentially targeted trees based on their intolerance of flood stress. Non-flooded trees were not preferred or successfully colonized. This study demonstrates the host-selection strategy exhibited by X. germanus and X. crassiusculus in non-native habitats involves

  5. Non-Native Ambrosia Beetles as Opportunistic Exploiters of Living but Weakened Trees.

    Science.gov (United States)

    Ranger, Christopher M; Schultz, Peter B; Frank, Steven D; Chong, Juang H; Reding, Michael E

    2015-01-01

    Exotic Xylosandrus spp. ambrosia beetles established in non-native habitats have been associated with sudden and extensive attacks on a diverse range of living trees, but factors driving their shift from dying/dead hosts to living and healthy ones are not well understood. We sought to characterize the role of host physiological condition on preference and colonization by two invaders, Xylosandrus germanus and Xylosandrus crassiusculus. When given free-choice under field conditions among flooded and non-flooded deciduous tree species of varying intolerance to flooding, beetles attacked flood-intolerant tree species over more tolerant species within 3 days of initiating flood stress. In particular, flood-intolerant flowering dogwood (Cornus florida) sustained more attacks than flood-tolerant species, including silver maple (Acer saccharinum) and swamp white oak (Quercus bicolor). Ethanol, a key host-derived attractant, was detected at higher concentrations 3 days after initiating flooding within stems of flood intolerant species compared to tolerant and non-flooded species. A positive correlation was also detected between ethanol concentrations in stem tissue and cumulative ambrosia beetle attacks. When adult X. germanus and X. crassiusculus were confined with no-choice to stems of flood-stressed and non-flooded C. florida, more ejected sawdust resulting from tunneling activity was associated with the flood-stressed trees. Furthermore, living foundresses, eggs, larvae, and pupae were only detected within galleries created in stems of flood-stressed trees. Despite a capability to attack diverse tree genera, X. germanus and X. crassiusculus efficiently distinguished among varying host qualities and preferentially targeted trees based on their intolerance of flood stress. Non-flooded trees were not preferred or successfully colonized. This study demonstrates the host-selection strategy exhibited by X. germanus and X. crassiusculus in non-native habitats involves

  6. Am\\'elioration des Performances des Syst\\`emes Automatiques de Reconnaissance de la Parole pour la Parole Non Native

    CERN Document Server

    Bouselmi, Ghazi; Illina, Irina; Haton, Jean-Paul

    2007-01-01

    In this article, we present an approach for non native automatic speech recognition (ASR). We propose two methods to adapt existing ASR systems to the non-native accents. The first method is based on the modification of acoustic models through integration of acoustic models from the mother tong. The phonemes of the target language are pronounced in a similar manner to the native language of speakers. We propose to combine the models of confused phonemes so that the ASR system could recognize both concurrent pronounciations. The second method we propose is a refinment of the pronounciation error detection through the introduction of graphemic constraints. Indeed, non native speakers may rely on the writing of words in their uttering. Thus, the pronounctiation errors might depend on the characters composing the words. The average error rate reduction that we observed is (22.5%) relative for the sentence error rate, and 34.5% (relative) in word error rate.

  7. Modelling the introduction and spread of non-native species: international trade and climate change drive ragweed invasion.

    Science.gov (United States)

    Chapman, Daniel S; Makra, László; Albertini, Roberto; Bonini, Maira; Páldy, Anna; Rodinkova, Victoria; Šikoparija, Branko; Weryszko-Chmielewska, Elżbieta; Bullock, James M

    2016-09-01

    Biological invasions are a major driver of global change, for which models can attribute causes, assess impacts and guide management. However, invasion models typically focus on spread from known introduction points or non-native distributions and ignore the transport processes by which species arrive. Here, we developed a simulation model to understand and describe plant invasion at a continental scale, integrating repeated transport through trade pathways, unintentional release events and the population dynamics and local anthropogenic dispersal that drive subsequent spread. We used the model to simulate the invasion of Europe by common ragweed (Ambrosia artemisiifolia), a globally invasive plant that causes serious harm as an aeroallergen and crop weed. Simulations starting in 1950 accurately reproduced ragweed's current distribution, including the presence of records in climatically unsuitable areas as a result of repeated introduction. Furthermore, the model outputs were strongly correlated with spatial and temporal patterns of ragweed pollen concentrations, which are fully independent of the calibration data. The model suggests that recent trends for warmer summers and increased volumes of international trade have accelerated the ragweed invasion. For the latter, long distance dispersal because of trade within the invaded continent is highlighted as a key invasion process, in addition to import from the native range. Biosecurity simulations, whereby transport through trade pathways is halted, showed that effective control is only achieved by early action targeting all relevant pathways. We conclude that invasion models would benefit from integrating introduction processes (transport and release) with spread dynamics, to better represent propagule pressure from native sources as well as mechanisms for long-distance dispersal within invaded continents. Ultimately, such integration may facilitate better prediction of spatial and temporal variation in invasion

  8. Potential population and assemblage influences of non-native trout on native nongame fish in Nebraska headwater streams

    Science.gov (United States)

    Turek, Kelly C.; Pegg, Mark A.; Pope, Kevin L.; Schainost, Steve

    2014-01-01

    Non-native trout are currently stocked to support recreational fisheries in headwater streams throughout Nebraska. The influence of non-native trout introductions on native fish populations and their role in structuring fish assemblages in these systems is unknown. The objectives of this study were to determine (i) if the size structure or relative abundance of native fish differs in the presence and absence of non-native trout, (ii) if native fish-assemblage structure differs in the presence and absence of non-native trout and (iii) if native fish-assemblage structure differs across a gradient in abundances of non-native trout. Longnose dace Rhinichthys cataractae were larger in the presence of brown trout Salmo trutta and smaller in the presence of rainbow trout Oncorhynchus mykiss compared to sites without trout. There was also a greater proportion of larger white suckers Catostomus commersonii in the presence of brown trout. Creek chub Semotilus atromaculatus and fathead minnow Pimephales promelas size structures were similar in the presence and absence of trout. Relative abundances of longnose dace, white sucker, creek chub and fathead minnow were similar in the presence and absence of trout, but there was greater distinction in native fish-assemblage structure between sites with trout compared to sites without trout as trout abundances increased. These results suggest increased risk to native fish assemblages in sites with high abundances of trout. However, more research is needed to determine the role of non-native trout in structuring native fish assemblages in streams, and the mechanisms through which introduced trout may influence native fish populations.

  9. Direct and Indirect Influence of Non-Native Neighbours on Pollination and Fruit Production of a Native Plant.

    Directory of Open Access Journals (Sweden)

    Ana Montero-Castaño

    Full Text Available Entomophilous non-native plants can directly affect the pollination and reproductive success of native plant species and also indirectly, by altering the composition and abundance of floral resources in the invaded community. Separating direct from indirect effects is critical for understanding the mechanisms underlying the impacts of non-native species on recipient communities.Our aims are: (a to explore both the direct effect of the non-native Hedysarum coronarium and its indirect effect, mediated by the alteration of floral diversity, on the pollinator visitation rate and fructification of the native Leopoldia comosa and (b to distinguish whether the effects of the non-native species were due to its floral display or to its vegetative interactions.We conducted field observations within a flower removal experimental setup (i.e. non-native species present, absent and with its inflorescences removed at the neighbourhood scale.Our study illustrates the complexity of mechanisms involved in the impacts of non-native species on native species. Overall, Hedysarum increased pollinator visitation rates to Leopoldia target plants as a result of direct and indirect effects acting in the same direction. Due to its floral display, Hedysarum exerted a direct magnet effect attracting visits to native target plants, especially those made by the honeybee. Indirectly, Hedysarum also increased the visitation rate of native target plants. Due to the competition for resources mediated by its vegetative parts, it decreased floral diversity in the neighbourhoods, which was negatively related to the visitation rate to native target plants. Hedysarum overall also increased the fructification of Leopoldia target plants, even though such an increase was the result of other indirect effects compensating for the observed negative indirect effect mediated by the decrease of floral diversity.

  10. Seed rain under native and non-native tree species in the Cabo Rojo National Wildlife Refuge, Puerto Rico

    OpenAIRE

    2014-01-01

    Seed dispersal is a fundamental process in plant ecology and is of critical importance for the restoration of tropical communities. The lands of the Cabo Rojo National Wildlife Refuge (CRNWR), formerly under agriculture, were abandoned in the 1970s and colonized mainly by non-native tree species of degraded pastures. Here we described the seed rain under the most common native and non-native trees in the refuge in an attempt to determine if focal tree geographic origin (native versus non-nati...

  11. Introduction and spread of non-native parasites with Silurus glanis L. (Teleostei: Siluridae) in UK fisheries.

    Science.gov (United States)

    Reading, A J; Britton, J R; Davies, G D; Shinn, A P; Williams, C F

    2012-12-01

    Despite growing concern of the ecological risks posed by the European catfish Siluris glanis L. in freshwater fisheries, little information exists on the parasite fauna of this silurid catfish in Britain. Parasitological examinations of released S. glanis from four still-water fisheries in England revealed the presence of Thaparocleidus vistulensis (Siwak, 1932) and Ergasilus sieboldi (Nordmann, 1832), both non-native parasites, the latter known to be an important fish pathogen. This represents the first record of T. vistulensis from British freshwater fish. The human-assisted movement of S. glanis between UK recreational still-water fisheries provides a clear avenue for the introduction and spread of non-native parasites.

  12. 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...

  13. Habitat distribution for non-native Amazona viridigenalis within San Diego County using Maxent predictive model

    Science.gov (United States)

    Meseck, Kristin April

    Human propagated changes to the environment have adversely affected certain species while advantaging other species. Psittacines, or species that fall within the parrot family, have been found to be well adapted to modified environments. Over time, transportation of various parrot species for use in the exotic pet trade has caused accidental releases of individual parrots, resulting in species groups forming and colonizing in new, non-native environments, specifically urban and suburban ones. Amazona viridigenalis, the Red-crowned parrot, is a species that has adapted to living in several regions within the United States including Texas, Florida, and California. This species is endangered within its native range in the lowlands of eastern Mexico, yet has the largest population of any other psittacine species in California. Despite this interesting dichotomy this species remains severely understudied in its new range. Using geographic information systems and Maxent predictive model, this research aims to achieve a greater understanding of the extent of habitat suitable to the Amazona viridigenalis within San Diego County and the habitat variables that enable its establishment success. Presence locations where individuals of the species were using habitat were collected along with 12 important variables that represent Red-crowned parrot habitat elements. These were used in the creation of a predictive habitat model utilizing Maxent machine-learning technique. Three models were created using three different background extents from which the pseudo-absence points were generated. These models were tested for statistical significance and predictive accuracy. It was found that model performance significantly decreased with a decrease in size of model extent. The largest extent was chosen to model habitat using the five variables that were found to be the least correlated, achieved the most gain, and had the most explanatory power for the earlier models. The final model

  14. FlexAID: Revisiting Docking on Non-Native-Complex Structures.

    Science.gov (United States)

    Gaudreault, Francis; Najmanovich, Rafael J

    2015-07-27

    Small-molecule protein docking is an essential tool in drug design and to understand molecular recognition. In the present work we introduce FlexAID, a small-molecule docking algorithm that accounts for target side-chain flexibility and utilizes a soft scoring function, i.e. one that is not highly dependent on specific geometric criteria, based on surface complementarity. The pairwise energy parameters were derived from a large dataset of true positive poses and negative decoys from the PDBbind database through an iterative process using Monte Carlo simulations. The prediction of binding poses is tested using the widely used Astex dataset as well as the HAP2 dataset, while performance in virtual screening is evaluated using a subset of the DUD dataset. We compare FlexAID to AutoDock Vina, FlexX, and rDock in an extensive number of scenarios to understand the strengths and limitations of the different programs as well as to reported results for Glide, GOLD, and DOCK6 where applicable. The most relevant among these scenarios is that of docking on flexible non-native-complex structures where as is the case in reality, the target conformation in the bound form is not known a priori. We demonstrate that FlexAID, unlike other programs, is robust against increasing structural variability. FlexAID obtains equivalent sampling success as GOLD and performs better than AutoDock Vina or FlexX in all scenarios against non-native-complex structures. FlexAID is better than rDock when there is at least one critical side-chain movement required upon ligand binding. In virtual screening, FlexAID results are lower on average than those of AutoDock Vina and rDock. The higher accuracy in flexible targets where critical movements are required, intuitive PyMOL-integrated graphical user interface and free source code as well as precompiled executables for Windows, Linux, and Mac OS make FlexAID a welcome addition to the arsenal of existing small-molecule protein docking methods.

  15. Voice vs. Text Chats: Their Efficacy for Learning Probing Questions by Non-Native Speaking Medical Professionals in Online Courses

    Science.gov (United States)

    Ellis, Olga

    2012-01-01

    Through an English for Specific Purposes (ESP): Communication in Nursing online course, the present study examines the efficacy of synchronous voice-based and text-based chats as instructional and communicative modes in learning to use open questions for probing in therapeutic dialogues by non-native speaking (NNS) participants, students of a…

  16. Pragmatic Competence and Social Power Awareness: The Case of Written and Spoken Discourse in Non-Native English Environments

    Science.gov (United States)

    Pérez-Sabater, Carmen; Montero-Fleta, Begoña

    2014-01-01

    Following one of the new challenges suggested by the Common European Framework of Reference for Languages, a treatment was developed to enhance pragmatic competence, since this competence is not easy to acquire by non-native speakers. Within this context, we focused on pragmatic awareness in the workplace, an area of expertise in growing demand…

  17. Learning to Teach English Language in the Practicum: What Challenges do Non-Native ESL Student Teachers Face?

    Science.gov (United States)

    Gan, Zhengdong

    2013-01-01

    This study investigates the challenges sixteen non-native preservice ESL teachers in a Bachelor of Education (English Language) (BEdEL) programme from Hong Kong experienced in an eight-week teaching practicum. Qualitative data from semi-structured interviews and reflective journals were collected from all 16 participants to obtain a detailed…

  18. 3D Talking-Head Mobile App: A Conceptual Framework for English Pronunciation Learning among Non-Native Speakers

    Science.gov (United States)

    Ali, Ahmad Zamzuri Mohamad; Segaran, Kogilathah

    2013-01-01

    One of the critical issues pertaining learning English as second language successfully is pronunciation, which consequently contributes to learners' poor communicative power. This situation is moreover crucial among non-native speakers. Therefore, various initiatives have been taken in order to promote effective language learning, which includes…

  19. Descriptions of Difficult Conversations between Native and Non-Native English Speakers: In-Group Membership and Helping Behaviors

    Science.gov (United States)

    Young, Ray; Faux, William V., II

    2011-01-01

    This study illustrated the perceptions of native English speakers about difficult conversations with non-native English speakers. A total of 114 native English speakers enrolled in undergraduate communication courses at a regional state university answered a questionnaire about a recent difficult conversation the respondent had with a non-native…

  20. Age of Acquisition and Proficiency in a Second Language Independently Influence the Perception of Non-Native Speech

    Science.gov (United States)

    Archila-Suerte, Pilar; Zevin, Jason; Bunta, Ferenc; Hernandez, Arturo E.

    2012-01-01

    Sensorimotor processing in children and higher-cognitive processing in adults could determine how non-native phonemes are acquired. This study investigates how age-of-acquisition (AOA) and proficiency-level (PL) predict native-like perception of statistically dissociated L2 categories, i.e., within-category and between-category. In a similarity…

  1. Scaffolding Learning: Developing Materials to Support the Learning of Science and Language by Non-Native English-Speaking Students

    Science.gov (United States)

    Afitska, Oksana

    2016-01-01

    In recent years, the UK, like many other English first-language-speaking countries, has encountered a steady and continuous increase in the numbers of non-native English-speaking learners entering state primary and secondary schools. A significant proportion of these learners has specific language and subject learning needs, many of which can only…

  2. Effects of noise, reverberation and foreign accent on native and non-native listeners' performance of English speech comprehension.

    Science.gov (United States)

    Peng, Z Ellen; Wang, Lily M

    2016-05-01

    A large number of non-native English speakers may be found in American classrooms, both as listeners and talkers. Little is known about how this population comprehends speech in realistic adverse acoustical conditions. A study was conducted to investigate the effects of background noise level (BNL), reverberation time (RT), and talker foreign accent on native and non-native listeners' speech comprehension, while controlling for English language abilities. A total of 115 adult listeners completed comprehension tasks under 15 acoustic conditions: three BNLs (RC-30, RC-40, and RC-50) and five RTs (from 0.4 to 1.2 s). Fifty-six listeners were tested with speech from native English-speaking talkers and 59 with native Mandarin-Chinese-speaking talkers. Results show that, while higher BNLs were generally more detrimental to listeners with lower English proficiency, all listeners experienced significant comprehension deficits above RC-40 with native English talkers. This limit was lower (i.e., above RC-30), however, with Chinese talkers. For reverberation, non-native listeners as a group performed best with RT up to 0.6 s, while native listeners performed equally well up to 1.2 s. A matched foreign accent benefit has also been identified, where the negative impact of higher reverberation does not exist for non-native listeners who share the talker's native language.

  3. Students Writing Emails to Faculty: An Examination of E-Politeness among Native and Non-Native Speakers of English

    Science.gov (United States)

    Biesenbach-Lucas, Sigrun

    2007-01-01

    This study combines interlanguage pragmatics and speech act research with computer-mediated communication and examines how native and non-native speakers of English formulate low- and high-imposition requests to faculty. While some research claims that email, due to absence of non-verbal cues, encourages informal language, other research has…

  4. Unpacking Race, Culture, and Class in Rural Alaska: Native and Non-Native Multidisciplinary Professionals' Perceptions of Child Sexual Abuse

    Science.gov (United States)

    Bubar, Roe; Bundy-Fazioli, Kimberly

    2011-01-01

    The purpose of this study was to unpack notions of class, culture, and race as they relate to multidisciplinary team (MDT) professionals and their perceptions of prevalence in child sexual abuse cases in Native and non-Native rural Alaska communities. Power and privilege within professional settings is significant for all social work professionals…

  5. Language and Academic Identity: A Study of the Experiences of Non-Native English Speaking International Students

    Science.gov (United States)

    Halic, Olivia; Greenberg, Katherine; Paulus, Trena

    2009-01-01

    This phenomenological study explores the experiences of non-native English-speaking international students regarding language, culture and identity in the context of their graduate studies. Interviews were conducted with each of the eight participants. Interpretive analysis was used within a constructivist frame. The findings of this study are…

  6. Integrating Academic Language, Thinking, and Content: Learning Scaffolds for Non-Native Speakers in the Middle Grades

    Science.gov (United States)

    Zwiers, Jeff

    2006-01-01

    The purpose of this action research study was to explore possibilities for scaffolding academic language and historical thinking for non-native English speaking students in two middle school classrooms. The teaching approach focused on six dimensions of historical thinking: background knowledge, cause, effect, bias, empathy, and application. The…

  7. Musical ability and non-native speech-sound processing are linked through sensitivity to pitch and spectral information.

    Science.gov (United States)

    Kempe, Vera; Bublitz, Dennis; Brooks, Patricia J

    2015-05-01

    Is the observed link between musical ability and non-native speech-sound processing due to enhanced sensitivity to acoustic features underlying both musical and linguistic processing? To address this question, native English speakers (N = 118) discriminated Norwegian tonal contrasts and Norwegian vowels. Short tones differing in temporal, pitch, and spectral characteristics were used to measure sensitivity to the various acoustic features implicated in musical and speech processing. Musical ability was measured using Gordon's Advanced Measures of Musical Audiation. Results showed that sensitivity to specific acoustic features played a role in non-native speech-sound processing: Controlling for non-verbal intelligence, prior foreign language-learning experience, and sex, sensitivity to pitch and spectral information partially mediated the link between musical ability and discrimination of non-native vowels and lexical tones. The findings suggest that while sensitivity to certain acoustic features partially mediates the relationship between musical ability and non-native speech-sound processing, complex tests of musical ability also tap into other shared mechanisms. © 2014 The British Psychological Society.

  8. A Non-Native Student's Experience on Collaborating with Native Peers in Academic Literacy Development: A Sociopolitical Perspective

    Science.gov (United States)

    Cheng, Rui

    2013-01-01

    This sociopolitically-oriented case study aims to further explore the complex social network non-native students are engaged in during their literacy activities. In previous research, institutional policies, supervisors and instructors, and gatekeepers of target journals are normally regarded as key players to influence students fulfilling their…

  9. Communicative Functions of the Nurse-Patient Relationship: Observations of Native and Non-Native Nurses in United States Hospitals.

    Science.gov (United States)

    Hadley, Jo Linda

    A study compared the nurse-patient communication of native and non-native English-speaking nurses. Examination of the literature on nurse-patient relationships and a brief survey of native nurses yielded an instrument for observation of nurses. Ten nurses were observed for 3 hourse each. Transcripts of the observations of the five non-native…

  10. Scaffolding Learning: Developing Materials to Support the Learning of Science and Language by Non-Native English-Speaking Students

    Science.gov (United States)

    Afitska, Oksana

    2016-01-01

    In recent years, the UK, like many other English first-language-speaking countries, has encountered a steady and continuous increase in the numbers of non-native English-speaking learners entering state primary and secondary schools. A significant proportion of these learners has specific language and subject learning needs, many of which can only…

  11. The Development and Validation of the "Academic Spoken English Strategies Survey (ASESS)" for Non-Native English Speaking Graduate Students

    Science.gov (United States)

    Schroeder, Rui M.

    2016-01-01

    This study reports on the three-year development and validation of a new assessment tool--the Academic Spoken English Strategies Survey (ASESS). The questionnaire is the first of its kind to assess the listening and speaking strategy use of non-native English speaking (NNES) graduate students. A combination of sources was used to develop the…

  12. Impact of non-native plant removal on lizards in riparian habitats in the southwestern United States

    Science.gov (United States)

    Heather L. Bateman; Alice Chung-MacCoubrey; Howard L. Snell

    2008-01-01

    Many natural processes in the riparian cottonwood (Populus deltoides) forest of the Middle Rio Grande (MRG) in the southwestern United States have been disrupted or altered, allowing non-native plants such as saltcedar (Tamarix spp.) and Russian olive (Elaeagnus angustifolia) to establish. We investigated...

  13. Competitive effects of non-native plants are lowest in native plant communities that are most vulnerable to invasion

    Science.gov (United States)

    J.Stephen Brewer; W. Chase Bailey

    2014-01-01

    Despite widespread acknowledgment that disturbance favors invasion, a hypothesis that has received little attention is whether non-native invaders have greater competitive effects on native plants in undisturbed habitats than in disturbed habitats. This hypothesis derives from the assumption that competitive interactions are more persistent in habitats that have not...

  14. Summer distribution and species richness of non-native fishes in the mainstem Willamette River, oregon, 1944-2006

    Science.gov (United States)

    We reviewed the results of seven extensive and two reach-specific fish surveys conducted on the mainstem Willamette River between 1944 and 2006 to document changes in the summer distribution and species richness of non-native fishes through time and the relative abundances of the...

  15. Non-Native Japanese Listeners' Perception of Vowel Length Contrasts in Japanese and Modern Standard Arabic (MSA)

    Science.gov (United States)

    Tsukada, Kimiko

    2012-01-01

    This study aimed to compare the perception of short vs. long vowel contrasts in Japanese and Modern Standard Arabic (MSA) by four groups of listeners differing in their linguistic backgrounds: native Arabic (NA), native Japanese (NJ), non-native Japanese (NNJ) and Australian English (OZ) speakers. The NNJ and OZ groups shared the first language…

  16. The Pedagogy and Its Effectiveness among Native and Non-Native English Speaking Teachers in the Korean EFL Context

    Science.gov (United States)

    Nam, Hyun Ha

    2010-01-01

    As English progressively becomes the global language, many native English speakers move to foreign countries to work as English teachers. However a review of the literature reveals that there is little research on their actual performance compared to the non-native local English teachers. This comparative case study examines pedagogic practices of…

  17. Memory for non-native language: the role of lexical processing in the retention of surface form.

    Science.gov (United States)

    Sampaio, Cristina; Konopka, Agnieszka E

    2013-01-01

    Research on memory for native language (L1) has consistently shown that retention of surface form is inferior to that of gist (e.g., Sachs, 1967). This paper investigates whether the same pattern is found in memory for non-native language (L2). We apply a model of bilingual word processing to more complex linguistic structures and predict that memory for L2 sentences ought to contain more surface information than L1 sentences. Native and non-native speakers of English were tested on a set of sentence pairs with different surface forms but the same meaning (e.g., "The bullet hit/struck the bull's eye"). Memory for these sentences was assessed with a cued recall procedure. Responses showed that native and non-native speakers did not differ in the accuracy of gist-based recall but that non-native speakers outperformed native speakers in the retention of surface form. The results suggest that L2 processing involves more intensive encoding of lexical level information than L1 processing.

  18. Unpacking Race, Culture, and Class in Rural Alaska: Native and Non-Native Multidisciplinary Professionals' Perceptions of Child Sexual Abuse

    Science.gov (United States)

    Bubar, Roe; Bundy-Fazioli, Kimberly

    2011-01-01

    The purpose of this study was to unpack notions of class, culture, and race as they relate to multidisciplinary team (MDT) professionals and their perceptions of prevalence in child sexual abuse cases in Native and non-Native rural Alaska communities. Power and privilege within professional settings is significant for all social work professionals…

  19. Microbial 1-butanol production: Identification of non-native production routes and in silico engineering interventions.

    Science.gov (United States)

    Ranganathan, Sridhar; Maranas, Costas D

    2010-07-01

    The potential of engineering microorganisms with non-native pathways for the synthesis of long-chain alcohols has been identified as a promising route to biofuels. We describe computationally derived predictions for assembling pathways for the production of biofuel candidate molecules and subsequent metabolic engineering modifications that optimize product yield. A graph-based algorithm illustrates that, by culling information from BRENDA and KEGG databases, all possible pathways that link the target product with metabolites present in the production host are identified. Subsequently, we apply our recent OptForce procedure to pinpoint reaction modifications that force the imposed product yield in Escherichia coli. We demonstrate this procedure by suggesting new pathways and genetic interventions for the overproduction of 1-butanol using the metabolic model for Escherichia coli. The graph-based search method recapitulates all recent discoveries based on the 2-ketovaline intermediate and hydroxybutyryl-CoA but also pinpoints one novel pathway through thiobutanoate intermediate that to the best of our knowledge has not been explored before.

  20. Non-native acylated homoserine lactones reveal that LuxIR quorum sensing promotes symbiont stability.

    Science.gov (United States)

    Studer, Sarah V; Schwartzman, Julia A; Ho, Jessica S; Geske, Grant D; Blackwell, Helen E; Ruby, Edward G

    2014-08-01

    Quorum sensing, a group behaviour coordinated by a diffusible pheromone signal and a cognate receptor, is typical of bacteria that form symbioses with plants and animals. LuxIR-type N-acyl L-homoserine (AHL) quorum sensing is common in Gram-negative Proteobacteria, and many members of this group have additional quorum-sensing networks. The bioluminescent symbiont Vibrio fischeri encodes two AHL signal synthases: AinS and LuxI. AinS-dependent quorum sensing converges with LuxI-dependent quorum sensing at the LuxR regulatory element. Both AinS- and LuxI-mediated signalling are required for efficient and persistent colonization of the squid host, Euprymna scolopes. The basis of the mutualism is symbiont bioluminescence, which is regulated by both LuxI- and AinS-dependent quorum sensing, and is essential for maintaining a colonization of the host. Here, we used chemical and genetic approaches to probe the dynamics of LuxI- and AinS-mediated regulation of bioluminescence during symbiosis. We demonstrate that both native AHLs and non-native AHL analogues can be used to non-invasively and specifically modulate induction of symbiotic bioluminescence via LuxI-dependent quorum sensing. Our data suggest that the first day of colonization, during which symbiont bioluminescence is induced by LuxIR, is a critical period that determines the stability of the V. fischeri population once symbiosis is established.

  1. Automatic pronunciation error detection in non-native speech: the case of vowel errors in Dutch.

    Science.gov (United States)

    van Doremalen, Joost; Cucchiarini, Catia; Strik, Helmer

    2013-08-01

    This research is aimed at analyzing and improving automatic pronunciation error detection in a second language. Dutch vowels spoken by adult non-native learners of Dutch are used as a test case. A first study on Dutch pronunciation by L2 learners with different L1s revealed that vowel pronunciation errors are relatively frequent and often concern subtle acoustic differences between the realization and the target sound. In a second study automatic pronunciation error detection experiments were conducted to compare existing measures to a metric that takes account of the error patterns observed to capture relevant acoustic differences. The results of the two studies do indeed show that error patterns bear information that can be usefully employed in weighted automatic measures of pronunciation quality. In addition, it appears that combining such a weighted metric with existing measures improves the equal error rate by 6.1 percentage points from 0.297, for the Goodness of Pronunciation (GOP) algorithm, to 0.236.

  2. Information encoded in non-native states drives substrate-chaperone pairing.

    Science.gov (United States)

    Mapa, Koyeli; Tiwari, Satyam; Kumar, Vignesh; Jayaraj, Gopal Gunanathan; Maiti, Souvik

    2012-09-05

    Many proteins refold in vitro through kinetic folding intermediates that are believed to be by-products of native-state centric evolution. These intermediates are postulated to play only minor roles, if any, in vivo because they lack any information related to translation-associated vectorial folding. We demonstrate that refolding intermediate of a test protein, generated in vitro, is able to find its cognate chaperone, from the whole complement of Escherichia coli soluble chaperones. Cognate chaperone-binding uniquely alters the conformation of non-native substrate. Importantly, precise chaperone targeting of substrates are maintained as long as physiological molar ratios of chaperones remain unaltered. Using a library of different chaperone substrates, we demonstrate that kinetically trapped refolding intermediates contain sufficient structural features for precise targeting to cognate chaperones. We posit that evolution favors sequences that, in addition to coding for a functional native state, encode folding intermediates with higher affinity for cognate chaperones than noncognate ones.

  3. Atmospheric dust accumulation on native and non-native species: effects on gas exchange parameters.

    Science.gov (United States)

    González, Juan A; Prado, Fernando E; Piacentini, Ruben D

    2014-05-01

    Plants are continuously exposed to atmospheric particulate matter (dust), and their leaves are the main receptors of deposited dust. The objective of this study was to assess the effects of dust deposition on leaf gas exchange parameters of 17 native and non-native tree and shrub species growing in Gran San Miguel de Tucumán in northwestern Argentina. Maximum assimilation rate (), stomatal conductance (), transpiration rate (), internal CO concentration (), and instantaneous water-use efficiency (WUE) were measured in cleaned leaves (CL) and dusted leaves (DL) of different species on November 2010, July 2011, and September 2011. In almost all studied species, gas exchange parameters were significantly affected by dust deposition. Values for , , and of DL were significantly reduced in 11, 12, and 14 species compared with CL. Morphological leaf traits seem to be related to reduction. Indeed, L. and (Mart. ex DC.) Standl. species with pubescent leaves and thick ribs showed the highest reduction percentages. Contrarily, and WUE were increased in DL but were less responsive to dust deposition than other parameters. Increases of and WUE were significant in 5 and 11 species, respectively. Correlation analyses between /, /, and / pairs showed significant positive linear correlations in CL and DL of many studied species, including small and tall plants. These results suggest that leaf stomatal factors and shade-induced effect by accumulated dust are primarily responsible for the observed reductions in photosynthesis rate of DL.

  4. Exploring the beliefs of native and non-native English speaking kindergarten teachers in Taiwan

    Directory of Open Access Journals (Sweden)

    Chiung-Wen Chang

    2012-12-01

    Full Text Available This study investigates the beliefs of native and non-native English speaking teachers on teaching English in kindergartens. A qualitative case study design is used to construct individual portraits and a cross-case analysis of several kindergarten teachers and analyze data following the qualitative data analysis methods by Taylor and Bodgan (1998. Data collected by interview and classroom observation show 4 different beliefs to be salient across the cases: language learning, the role of the teacher, the role of the learner, and self-efficacy. Data analysis shows teacher beliefs that are complex and closely related to the teacher’s life and learning experiences, multiple identities, and different environmental affordances and constraints. Therefore, the teachers’ subjective account from an emic perspective is useful for describing this complexity. The findings of this study have implications for constructing "a technical culture" (Kleinsasser, 1993, in which teachers may find themselves, that supports the teacher, and that contributes to quality teaching and professional growth.

  5. Do non-native plant species affect the shape of productivity-diversity relationships?

    Science.gov (United States)

    Drake, J.M.; Cleland, E.E.; Horner-Devine, M. C.; Fleishman, E.; Bowles, C.; Smith, M.D.; Carney, K.; Emery, S.; Gramling, J.; Vandermast, D.B.; Grace, J.B.

    2008-01-01

    The relationship between ecosystem processes and species richness is an active area of research and speculation. Both theoretical and experimental studies have been conducted in numerous ecosystems. One finding of these studies is that the shape of the relationship between productivity and species richness varies considerably among ecosystems and at different spatial scales, though little is known about the relative importance of physical and biological mechanisms causing this variation. Moreover, despite widespread concern about changes in species' global distributions, it remains unclear if and how such large-scale changes may affect this relationship. We present a new conceptual model of how invasive species might modulate relationships between primary production and species richness. We tested this model using long-term data on relationships between aboveground net primary production and species richness in six North American terrestrial ecosystems. We show that primary production and abundance of non-native species are both significant predictors of species richness, though we fail to detect effects of invasion extent on the shapes of the relationship between species richness and primary production.

  6. Novel antibodies reveal inclusions containing non-native SOD1 in sporadic ALS patients.

    Directory of Open Access Journals (Sweden)

    Karin Forsberg

    Full Text Available Mutations in CuZn-superoxide dismutase (SOD1 cause amyotrophic lateral sclerosis (ALS and are found in 6% of ALS patients. Non-native and aggregation-prone forms of mutant SOD1s are thought to trigger the disease. Two sets of novel antibodies, raised in rabbits and chicken, against peptides spaced along the human SOD1 sequence, were by enzyme-linked immunosorbent assay and an immunocapture method shown to be specific for denatured SOD1. These were used to examine SOD1 in spinal cords of ALS patients lacking mutations in the enzyme. Small granular SOD1-immunoreactive inclusions were found in spinal motoneurons of all 37 sporadic and familial ALS patients studied, but only sparsely in 3 of 28 neurodegenerative and 2 of 19 non-neurological control patients. The granular inclusions were by confocal microscopy found to partly colocalize with markers for lysosomes but not with inclusions containing TAR DNA binding protein-43, ubiquitin or markers for endoplasmic reticulum, autophagosomes or mitochondria. Granular inclusions were also found in carriers of SOD1 mutations and in spinobulbar muscular atrophy (SBMA patients and they were the major type of inclusion detected in ALS patients homozygous for the wild type-like D90A mutation. The findings suggest that SOD1 may be involved in ALS pathogenesis in patients lacking mutations in the enzyme.

  7. Surveillance potential of non-native Hawaiian birds for detection of West Nile Virus

    Science.gov (United States)

    Hofmeister, Erik K.; Dusek, Robert J.; Brand, Christopher J.

    2015-01-01

    West Nile virus (WNV) was first detected in North America in 1999. Alaska and Hawaii (HI) remain the only U.S. states in which transmission of WNV has not been detected. Dead bird surveillance has played an important role in the detection of the virus geographically, as well as temporally. In North America, corvids have played a major role in WNV surveillance; however, the only corvid in HI is the endangered Hawaiian crow that exists only in captivity, thus precluding the use of this species for WNV surveillance in HI. To evaluate the suitability of alternate avian species for WNV surveillance, we experimentally challenged seven abundant non-native bird species present in HI with WNV and compared mortality, viremia, oral shedding of virus, and seroconversion. For detection of WNV in oral swabs, we compared viral culture, reverse-transcriptase polymerase chain reaction, and the RAMP® test. For detection of antibodies to WNV, we compared an indirect and a competitive enzyme-linked immunoassay. We found four species (house sparrow, house finch, Japanese white-eye, and Java sparrow) that may be useful in dead bird surveillance for WNV; while common myna, zebra dove, and spotted dove survived infection and may be useful in serosurveillance.

  8. ERP evidence for different strategies in the processing of case markers in native speakers and non-native learners

    Directory of Open Access Journals (Sweden)

    Friederici Angela D

    2007-03-01

    Full Text Available Abstract Background The present experiments were designed to test how the linguistic feature of case is processed in Japanese by native and non-native listeners. We used a miniature version of Japanese as a model to compare sentence comprehension mechanisms in native speakers and non-native learners who had received training until they had mastered the system. In the first experiment we auditorily presented native Japanese speakers with sentences containing incorrect double nominatives and incorrect double accusatives, and with correct sentences. In the second experiment we tested trained non-natives with the same material. Based on previous research in German we expected an N400-P600 biphasic ERP response with specific modulations depending on the violated case and whether the listeners were native or non-native. Results For native Japanese participants the general ERP response to the case violations was an N400-P600 pattern. Double accusatives led to an additional enhancement of the P600 amplitude. For the learners a native-like P600 was present for double accusatives and for double nominatives. The additional negativity, however, was present in learners only for double nominative violations, and it was characterized by a different topographical distribution. Conclusion The results indicate that native listeners use case markers for thematic as well as syntactic structure building during incremental sentence interpretation. The modulation of the P600 component for double accusatives possibly reflects case specific syntactic restrictions in Japanese. For adult language learners later processes, as reflected in the P600, seem to be more native-like compared to earlier processes. The anterior distribution of the negativity and its selective emergence for canonical sentences were taken to suggest that the non-native learners resorted to a rather formal processing strategy whereby they relied to a large degree on the phonologically salient

  9. Reasons for drop-out in rehabilitation treatment of native patients and non-native patients with chronic low back pain in the Netherlands : a medical file study

    NARCIS (Netherlands)

    Sloots, M.; Dekker, J. H. M.; Bartels, E. A. C.; Geertzen, J. H. B.; Dekker, J.

    2010-01-01

    Aim. Drop-out of rehabilitation treatment in non-native patients with chronic low back pain has been reported to be higher than in native Dutch patients. It was expected that drop-out in non-native patients would be due to different expectations on the content of rehabilitation treatment and due to

  10. Perceived Job Skill Limitations and Participation in Education and Training Opportunities: Differences between Us Native-Born and Non-Native-Born Individuals

    Science.gov (United States)

    Smith, M. Cecil; Smith, Thomas J.

    2010-01-01

    Data from the 2003 National Assessment of Adult Literacy were examined to determine if non-native-born adults in the US differ from their native-born counterparts in (1) participation in work-related training or education, and (2) perceptions that specific skills limit their job opportunities. Results indicated that non-native-born persons were…

  11. Diversity of fungal endophytes in non-native Phragmites australis in the Great Lakes

    Science.gov (United States)

    Clay, Keith; Shearin, Zachery; Bourke, Kimberly; Bickford, Wesley A.; Kowalski, Kurt P.

    2016-01-01

    Plant–microbial interactions may play a key role in plant invasions. One common microbial interaction takes place between plants and fungal endophytes when fungi asymptomatically colonize host plant tissues. The objectives of this study were to isolate and sequence fungal endophytes colonizing non-native Phragmites australis in the Great Lakes region to evaluate variation in endophyte community composition among three host tissue types and three geographical regions. We collected entire ramets from multiple clones and populations, surface sterilized plant tissues, and plated replicate tissue samples from leaves, stems, and rhizomes on corn meal agar plates to culture and isolate fungal endophytes. Isolates were then subjected to Sanger sequencing of the ITS region of the nuclear ribosomal DNA. Sequences were compared to fungal databases to define operational taxonomic units (OTUs) that were analyzed statistically for community composition. In total, we obtained 173 endophyte isolates corresponding to 55 OTUs, 39 of which were isolated only a single time. The most common OTU corresponded most closely to Sarocladium strictum and comprised 25 % of all fungal isolates. More OTUs were found in stem tissues, but endophyte diversity was greatest in rhizome tissues. PERMANOVA analyses indicated significant differences in endophyte communities among tissue types, geographical regions, and the interaction between those factors, but no differences among individual ramets were detected. The functional role of the isolated endophytes is not yet known, but one genus isolated here (Stagonospora) has been reported to enhance Phragmites growth. Understanding the diversity and functions of Phragmites endophytes may provide targets for control measures based on disrupting host plant/endophyte interactions.

  12. Fine-scale determinants of conservation value of river reaches in a hotspot of native and non-native species diversity.

    Science.gov (United States)

    Maceda-Veiga, Alberto; Baselga, Andrés; Sousa, Ronaldo; Vilà, Montserrat; Doadrio, Ignacio; de Sostoa, Adolfo

    2017-01-01

    Global freshwater biodiversity is declining at unprecedented rates while non-native species are expanding. Examining diversity patterns across variable river conditions can help develop better management strategies. However, many indicators can be used to determine the conservartion value of aquatic communities, and little is known of how well they correlate to each other in making diagnostics, including when testing for the efficacy of protected areas. Using an extensive data set (99,700km(2), n=530 sites) across protected and unprotected river reaches in 15 catchments of NE Spain, we examine correlations among 20 indicators of conservation value of fish communities, including the benefits they provide to birds and threatened mammals and mussels. Our results showed that total native fish abundance or richness correlated reasonably well with many native indicators. However, the lack of a strong congruence led modelling techniques to identify different river attributes for each indicator of conservation value. Overall, tributaries were identified as native fish refugees, and nutrient pollution, salinization, low water velocity and poor habitat structure as major threats to the native biota. We also found that protected areas offered limited coverage to major components of biodiversity, including rarity, threat and host-parasite relationships, even though values of non-native indicators were notably reduced. In conclusion, restoring natural hydrological regimes and water chemical status is a priority to stem freshwater biodiversity loss in this region. A complementary action can be the protection of tributaries, but more studies examining multiple components of diversity are necessary to fully test their potential as fluvial reserves in Mediterranean climate areas. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. Biosecurity and vector behaviour: evaluating the potential threat posed by anglers and canoeists as pathways for the spread of invasive non-native species and pathogens.

    Science.gov (United States)

    Anderson, Lucy G; White, Piran C L; Stebbing, Paul D; Stentiford, Grant D; Dunn, Alison M

    2014-01-01

    Invasive non-native species (INNS) endanger native biodiversity and are a major economic problem. The management of pathways to prevent their introduction and establishment is a key target in the Convention on Biological Diversity's Aichi biodiversity targets for 2020. Freshwater environments are particularly susceptible to invasions as they are exposed to multiple introduction pathways, including non-native fish stocking and the release of boat ballast water. Since many freshwater INNS and aquatic pathogens can survive for several days in damp environments, there is potential for transport between water catchments on the equipment used by recreational anglers and canoeists. To quantify this biosecurity risk, we conducted an online questionnaire with 960 anglers and 599 canoeists to investigate their locations of activity, equipment used, and how frequently equipment was cleaned and/or dried after use. Anglers were also asked about their use and disposal of live bait. Our results indicate that 64% of anglers and 78.5% of canoeists use their equipment/boat in more than one catchment within a fortnight, the survival time of many of the INNS and pathogens considered in this study and that 12% of anglers and 50% of canoeists do so without either cleaning or drying their kit between uses. Furthermore, 8% of anglers and 28% of canoeists had used their equipment overseas without cleaning or drying it after each use which could facilitate both the introduction and secondary spread of INNS in the UK. Our results provide a baseline against which to evaluate the effectiveness of future biosecurity awareness campaigns, and identify groups to target with biosecurity awareness information. Our results also indicate that the biosecurity practices of these groups must improve to reduce the likelihood of inadvertently spreading INNS and pathogens through these activities.

  14. Effective Prediction of Errors by Non-native Speakers Using Decision Tree for Speech Recognition-Based CALL System

    Science.gov (United States)

    Wang, Hongcui; Kawahara, Tatsuya

    CALL (Computer Assisted Language Learning) systems using ASR (Automatic Speech Recognition) for second language learning have received increasing interest recently. However, it still remains a challenge to achieve high speech recognition performance, including accurate detection of erroneous utterances by non-native speakers. Conventionally, possible error patterns, based on linguistic knowledge, are added to the lexicon and language model, or the ASR grammar network. However, this approach easily falls in the trade-off of coverage of errors and the increase of perplexity. To solve the problem, we propose a method based on a decision tree to learn effective prediction of errors made by non-native speakers. An experimental evaluation with a number of foreign students learning Japanese shows that the proposed method can effectively generate an ASR grammar network, given a target sentence, to achieve both better coverage of errors and smaller perplexity, resulting in significant improvement in ASR accuracy.

  15. A professional development scheme for non-native speaking teachers of English from the Arab world: an action research study

    OpenAIRE

    Rabi, Sally A

    2013-01-01

    Following an action research framework, my research investigates professional development for English Language teachers in the Arab World, who are non-native\\ud speakers of English themselves.\\ud \\ud The thesis has five chapters: Literature Review, Critical Contexts, Methodology of the Study, Data Analysis and Presentation, and finally the Discussion and Findings of the\\ud research. The Literature Review covers works relevant to the area of the study in relation to existing teacher practices,...

  16. Recognition of spoken words by native and non-native listeners: Talker-, listener-, and item-related factors

    Science.gov (United States)

    Bradlow, Ann R.; Pisoni, David B.

    2012-01-01

    In order to gain insight into the interplay between the talker-, listener-, and item-related factors that influence speech perception, a large multi-talker database of digitally recorded spoken words was developed, and was then submitted to intelligibility tests with multiple listeners. Ten talkers produced two lists of words at three speaking rates. One list contained lexically “easy” words (words with few phonetically similar sounding “neighbors” with which they could be confused), and the other list contained lexically “hard” (wordswords with many phonetically similar sounding “neighbors”). An analysis of the intelligibility data obtained with native speakers of English (experiment 1) showed a strong effect of lexical similarity. Easy words had higher intelligibility scores than hard words. A strong effect of speaking rate was also found whereby slow and medium rate words had higher intelligibility scores than fast rate words. Finally, a relationship was also observed between the various stimulus factors whereby the perceptual difficulties imposed by one factor, such as a hard word spoken at a fast rate, could be overcome by the advantage gained through the listener's experience and familiarity with the speech of a particular talker. In experiment 2, the investigation was extended to another listener population, namely, non-native listeners. Results showed that the ability to take advantage of surface phonetic information, such as a consistent talker across items, is a perceptual skill that transfers easily from first to second language perception. However, non-native listeners had particular difficulty with lexically hard words even when familiarity with the items was controlled, suggesting that non-native word recognition may be compromised when fine phonetic discrimination at the segmental level is required. Taken together, the results of this study provide insight into the signal-dependent and signal-independent factors that influence spoken

  17. STUDENTS WRITING EMAILS TO FACULTY: AN EXAMINATION OF E-POLITENESS AMONG NATIVE AND NON-NATIVE SPEAKERS OF ENGLISH

    Directory of Open Access Journals (Sweden)

    Sigrun Biesenbach-Lucas

    2007-02-01

    Full Text Available This study combines interlanguage pragmatics and speech act research with computer-mediated communication and examines how native and non-native speakers of English formulate low- and high-imposition requests to faculty. While some research claims that email, due to absence of non-verbal cues, encourages informal language, other research has claimed the opposite. However, email technology also allows writers to plan and revise messages before sending them, thus affording the opportunity to edit not only for grammar and mechanics, but also for pragmatic clarity and politeness.The study examines email requests sent by native and non-native English speaking graduate students to faculty at a major American university over a period of several semesters and applies Blum-Kulka, House, and Kasper’s (1989 speech act analysis framework – quantitatively to distinguish levels of directness, i.e. pragmatic clarity; and qualitatively to compare syntactic and lexical politeness devices, the request perspectives, and the specific linguistic request realization patterns preferred by native and non-native speakers. Results show that far more requests are realized through direct strategies as well as hints than conventionally indirect strategies typically found in comparative speech act studies. Politeness conventions in email, a text-only medium with little guidance in the academic institutional hierarchy, appear to be a work in progress, and native speakers demonstrate greater resources in creating e-polite messages to their professors than non-native speakers. A possible avenue for pedagogical intervention with regard to instruction in and acquisition of politeness routines in hierarchically upward email communication is presented.

  18. Student perceptions of native and non-native speaker language instructors: A comparison of ESL and Spanish

    Directory of Open Access Journals (Sweden)

    Laura Callahan

    2006-12-01

    Full Text Available The question of the native vs. non-native speaker status of second and foreign language instructors has been investigated chiefly from the perspective of the teacher. Anecdotal evidence suggests that students have strong opinions on the relative qualities of instruction by native and non-native speakers. Most research focuses on students of English as a foreign or second language. This paper reports on data gathered through a questionnaire administered to 55 university students: 31 students of Spanish as FL and 24 students of English as SL. Qualitative results show what strengths students believe each type of instructor has, and quantitative results confirm that any gap students may perceive between the abilities of native and non-native instructors is not so wide as one might expect based on popular notions of the issue. ESL students showed a stronger preference for native-speaker instructors overall, and were at variance with the SFL students' ratings of native-speaker instructors' performance on a number of aspects. There was a significant correlation in both groups between having a family member who is a native speaker of the target language and student preference for and self-identification with a native speaker as instructor. (English text

  19. Kinetic network models of tryptophan mutations in β-hairpins reveal the importance of non-native interactions.

    Science.gov (United States)

    Razavi, Asghar M; Voelz, Vincent A

    2015-06-09

    We present an analysis of the most extensive explicit-solvent simulations of β-hairpins to date (9.4 ms in aggregate), with the aim of probing the effects of tryptophan mutations on folding. From molecular simulations of GB1 hairpin, trpzip4, trpzip5, and trpzip6 performed on Folding@home, Markov State Models (MSMs) were constructed using a unified set of metastable states, enabling objective comparison of folding mechanisms. MSM models display quantitative agreement with experimental structural observables and folding kinetics, and predict multimodal kinetics due to specific non-native kinetic traps, which be identified as on- or off-pathway from the network topology. We quantify kinetic frustration by several means, including the s-ensemble method to evaluate glasslike behavior. Free-energy profiles and transition state movement clearly show stabilization of non-native states as Trp mutations are introduced. Remarkably, we find that "β-capped" sequences (trpzip4 and trpzip5) are able to overcome this frustration and remain cooperative two-state folders with a large time-scale gap. These results suggest that, while β-capping motifs are robust, fold stabilization by tryptophan generally may require overcoming significant non-native kinetic traps, perhaps explaining their under-representation in natural proteins.

  20. Dissociating Cortical Activity during Processing of Native and Non-Native Audiovisual Speech from Early to Late Infancy

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    Eswen Fava

    2014-08-01

    Full Text Available Initially, infants are capable of discriminating phonetic contrasts across the world’s languages. Starting between seven and ten months of age, they gradually lose this ability through a process of perceptual narrowing. Although traditionally investigated with isolated speech sounds, such narrowing occurs in a variety of perceptual domains (e.g., faces, visual speech. Thus far, tracking the developmental trajectory of this tuning process has been focused primarily on auditory speech alone, and generally using isolated sounds. But infants learn from speech produced by people talking to them, meaning they learn from a complex audiovisual signal. Here, we use near-infrared spectroscopy to measure blood concentration changes in the bilateral temporal cortices of infants in three different age groups: 3-to-6 months, 7-to-10 months, and 11-to-14-months. Critically, all three groups of infants were tested with continuous audiovisual speech in both their native and another, unfamiliar language. We found that at each age range, infants showed different patterns of cortical activity in response to the native and non-native stimuli. Infants in the youngest group showed bilateral cortical activity that was greater overall in response to non-native relative to native speech; the oldest group showed left lateralized activity in response to native relative to non-native speech. These results highlight perceptual tuning as a dynamic process that happens across modalities and at different levels of stimulus complexity.

  1. Arbuscular mycorrhizal colonization in black poplar roots after defoliation by a non-native and a native insect

    Directory of Open Access Journals (Sweden)

    Zampieri E

    2016-08-01

    Full Text Available A major goal in ecology is to understand how interactions among organisms influence ecosystem services. This work compares the effects of two Lepidoptera defoliators, one non-native (Hyphantria cunea and one native (Lymantria dispar to Europe, on the colonization of black poplar (the Populus nigra clone “Jean Pourtet” roots by an arbuscular mycorrhizal (AM symbiotic fungus (Funneliformis mosseae in a pot experiment. The effects of defoliation have also been assessed on the expression of fungal and plant genes playing a role during symbiosis. Both control and defoliated poplars have shown a low level of mycorrhization. Additionally, neither the non-native nor the native insect seem to strongly affect the AM colonization, at least at the time of observation (eight days from the end of the defoliation. Concerning the gene expression analysis, our results suggest that defoliation does not influence neither the expression of genes coding for a fungal and a plant phosphate transporter nor that of a gene coding for a fungal ATPase, and that there were no differences between defoliation carried out by the non-native and the native insect.

  2. Perception of native and non-native affricate-fricative contrasts: cross-language tests on adults and infants.

    Science.gov (United States)

    Tsao, Feng-Ming; Liu, Huei-Mei; Kuhl, Patricia K

    2006-10-01

    Previous studies have shown improved sensitivity to native-language contrasts and reduced sensitivity to non-native phonetic contrasts when comparing 6-8 and 10-12-month-old infants. This developmental pattern is interpreted as reflecting the onset of language-specific processing around the first birthday. However, generalization of this finding is limited by the fact that studies have yielded inconsistent results and that insufficient numbers of phonetic contrasts have been tested developmentally; this is especially true for native-language phonetic contrasts. Three experiments assessed the effects of language experience on affricate-fricative contrasts in a cross-language study of English and Mandarin adults and infants. Experiment 1 showed that English-speaking adults score lower than Mandarin-speaking adults on Mandarin alveolo-palatal affricate-fricative discrimination. Experiment 2 examined developmental change in the discrimination of this contrast in English- and Mandarin-leaning infants between 6 and 12 months of age. The results demonstrated that native-language performance significantly improved with age while performance on the non-native contrast decreased. Experiment 3 replicated the perceptual improvement for a native contrast: 6-8 and 10-12-month-old English-learning infants showed a performance increase at the older age. The results add to our knowledge of the developmental patterns of native and non-native phonetic perception.

  3. The Acquisition of English Focus Marking by Non-Native Speakers

    Science.gov (United States)

    Baker, Rachel Elizabeth

    This dissertation examines Mandarin and Korean speakers' acquisition of English focus marking, which is realized by accenting particular words within a focused constituent. It is important for non-native speakers to learn how accent placement relates to focus in English because appropriate accent placement and realization makes a learner's English more native-like and easier to understand. Such knowledge may also improve their English comprehension skills. In this study, 20 native English speakers, 20 native Mandarin speakers, and 20 native Korean speakers participated in four experiments: (1) a production experiment, in which they were recorded reading the answers to questions, (2) a perception experiment, in which they were asked to determine which word in a recording was the last prominent word, (3) an understanding experiment, in which they were asked whether the answers in recorded question-answer pairs had context-appropriate prosody, and (4) an accent placement experiment, in which they were asked which word they would make prominent in a particular context. Finally, a new group of native English speakers listened to utterances produced in the production experiment, and determined whether the prosody of each utterance was appropriate for its context. The results of the five experiments support a novel predictive model for second language prosodic focus marking acquisition. This model holds that both transfer of linguistic features from a learner's native language (L1) and features of their second language (L2) affect learners' acquisition of prosodic focus marking. As a result, the model includes two complementary components: the Transfer Component and the L2 Challenge Component. The Transfer Component predicts that prosodic structures in the L2 will be more easily acquired by language learners that have similar structures in their L1 than those who do not, even if there are differences between the L1 and L2 in how the structures are realized. The L2

  4. Status of the Island Night Lizard and Two Non-Native Lizards on Outlying Landing Field San Nicolas Island, California

    Science.gov (United States)

    Fellers, Gary M.; Drost, Charles A.; Murphey, Thomas G.

    2008-01-01

    More than 900 individually marked island night lizards (Xantusia riversiana) were captured on San Nicolas Island, California, between 1984 and 2007 as part of an ongoing study to monitor the status of this threatened species. Our data suggest that at least a few lizards are probably more than 20 years old, and one lizard would be 31.5 years old if it grew at an average rate for the population. Ages of 20 and 30 years seem reasonable given the remarkably slow growth during capture intervals of more than a decade for five of the lizards which we estimated to be 20 or more years old. Like other lizards, island night lizard growth rates vary by size, with larger lizards growing more slowly. In general, growth rates were somewhat greater on San Nicolas Island (compared with Santa Barbara Island), and this increase was sustained through all of the intermediate size classes. The higher growth rate may account for the somewhat larger lizards present on San Nicolas Island, although we cannot discount the possibility that night lizards on San Nicolas are merely living longer. The high percentage of small lizards in the Eucalyptus habitat might seem to reflect a healthy population in that habitat, but the high proportion of small lizards appears to be caused by good reproduction in the 1900s and substantially poorer reproduction in subsequent years. The Eucalyptus habitat has dried quite a bit in recent years. Night lizards in the Haplopappus/Grassland habitat have shown an increase in the proportion of larger lizards since 2000. There has also been an increase in the proportion of large lizards in the Rock Cobble habitat at Redeye Beach. However, there are has been some change in habitat with more elephant seals occupying the same area just above the high tide as do the night lizards. Southern alligator lizards and side-blotched lizards are both non-native on San Nicolas Island. Neither lizard causes obvious harm to island night lizards, and management time and effort should

  5. Estimating Invasion Success by Non-Native Trees in a National Park Combining WorldView-2 Very High Resolution Satellite Data and Species Distribution Models

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    Antonio T. Monteiro

    2017-01-01

    Full Text Available Invasion by non-native tree species is an environmental and societal challenge requiring predictive tools to assess invasion dynamics. The frequent scale mismatch between such tools and on-ground conservation is currently limiting invasion management. This study aimed to reduce these scale mismatches, assess the success of non-native tree invasion and determine the environmental factors associated to it. A hierarchical scaling approach combining species distribution models (SDMs and satellite mapping at very high resolution (VHR was developed to assess invasion by Acacia dealbata in Peneda-Gerês National Park, the only national park in Portugal. SDMs were first used to predict the climatically suitable areas for A. dealdata and satellite mapping with the random-forests classifier was then applied to WorldView-2 very-high resolution imagery to determine whether A. dealdata had actually colonized the predicted areas (invasion success. Environmental attributes (topographic, disturbance and canopy-related differing between invaded and non-invaded vegetated areas were then analyzed. The SDM results indicated that most (67% of the study area was climatically suitable for A. dealbata invasion. The onset of invasion was documented to 1905 and satellite mapping highlighted that 12.6% of study area was colonized. However, this species had only colonized 62.5% of the maximum potential range, although was registered within 55.6% of grid cells that were considerable unsuitable. Across these areas, the specific success rate of invasion was mostly below 40%, indicating that A. dealbata invasion was not dominant and effective management may still be possible. Environmental attributes related to topography (slope, canopy (normalized difference vegetation index (ndvi, land surface albedo and disturbance (historical burnt area differed between invaded and non-invaded vegetated area, suggesting that landscape attributes may alter at specific locations with Acacia

  6. Coniferous Canopy BRF Simulation Based on 3-D Realistic Scene

    Science.gov (United States)

    Wang, Xin-yun; Guo, Zhi-feng; Qin, Wen-han; Sun, Guo-qing

    2011-01-01

    It is difficulties for the computer simulation method to study radiation regime at large-scale. Simplified coniferous model was investigate d in the present study. It makes the computer simulation methods such as L-systems and radiosity-graphics combined method (RGM) more powerf ul in remote sensing of heterogeneous coniferous forests over a large -scale region. L-systems is applied to render 3-D coniferous forest scenarios: and RGM model was used to calculate BRF (bidirectional refle ctance factor) in visible and near-infrared regions. Results in this study show that in most cases both agreed well. Meanwhiie at a tree and forest level. the results are also good.

  7. Imported Asian swamp eels (Synbranchidae: Monopterus) in North American live food markets: Potential vectors of non-native parasites

    Science.gov (United States)

    Nico, Leo G.; Sharp, Paul; Collins, Timothy M.

    2011-01-01

    Since the 1990s, possibly earlier, large numbers of Asian swamp eels (Synbranchidae: Monopterus spp.), some wild-caught, have been imported live from various countries in Asia and sold in ethnic food markets in cities throughout the USA and parts of Canada. Such markets are the likely introduction pathway of some, perhaps most, of the five known wild populations of Asian swamp eels present in the continental United States. This paper presents results of a pilot study intended to gather baseline data on the occurrence and abundance of internal macroparasites infecting swamp eels imported from Asia to North American retail food markets. These data are important in assessing the potential role that imported swamp eels may play as possible vectors of non-native parasites. Examination of the gastrointestinal tracts and associated tissues of 19 adult-sized swamp eels—identified as M. albus "Clade C"—imported from Vietnam and present in a U.S. retail food market revealed that 18 (95%) contained macroparasites. The 394 individual parasites recovered included a mix of nematodes, acanthocephalans, cestodes, digeneans, and pentastomes. The findings raise concern because of the likelihood that some parasites infecting market swamp eels imported from Asia are themselves Asian taxa, some possibly new to North America. The ecological risk is exacerbated because swamp eels sold in food markets are occasionally retained live by customers and a few reportedly released into the wild. For comparative purposes, M. albus "Clade C" swamp eels from a non-native population in Florida (USA) were also examined and most (84%) were found to be infected with internal macroparasites. The current level of analysis does not allow us to confirm whether these are non-native parasites.

  8. Antipredator responses by native mosquitofish to non-native cichlids: An examination of the role of prey naiveté

    Science.gov (United States)

    Rehage, Jennifer S.; Dunlop, Katherine L.; Loftus, William F.

    2009-01-01

    The strong impact of non-native predators in aquatic systems is thought to relate to the evolutionary naiveté of prey. Due to isolation and limited dispersal, this naiveté may be relatively high in freshwater systems. In this study, we tested this notion by examining the antipredator response of native mosquitofish, Gambusia holbrooki, to two non-native predators found in the Everglades, the African jewelfish,Hemichromis letourneuxi, and the Mayan cichlid, Cichlasoma urophthalmus. We manipulated prey naiveté by using two mosquitofish populations that varied in their experience with the recent invader, the African jewelfish, but had similar levels of experience with the longer-established Mayan cichlid. Specifically, we tested these predictions: (1) predator hunting modes differed between the two predators, (2) predation rates would be higher by the novel jewelfish predator, (3) particularly on the naive population living where jewelfish have not invaded yet, (4) antipredator responses would be stronger to Mayan cichlids due to greater experience and weaker and/or ineffective to jewelfish, and (5) especially weakest by the naive population. We assayed prey and predator behavior, and prey mortality in lab aquaria where both predators and prey were free-ranging. Predator hunting modes and habitat domains differed, with jewelfish being more active search predators that used slightly higher parts of the water column and less of the habitat structure relative to Mayan cichlids. In disagreement with our predictions, predation rates were similar between the two predators, antipredator responses were stronger to African jewelfish (except for predator inspections), and there was no difference in response between jewelfish-savvy and jewelfish-naive populations. These results suggest that despite the novelty of introduced predators, prey may be able to respond appropriately if non-native predator archetypes are similar enough to those of native predators, if prey rely

  9. Coexistence of Native-Like and Non-Native Cytochrome c on Anionic Liposomes with Different Cardiolipin Content.

    Science.gov (United States)

    Pandiscia, Leah A; Schweitzer-Stenner, Reinhard

    2015-10-08

    We employed a combination of fluorescence, visible circular dichroism, and absorption spectroscopy to study the conformational changes of ferricytochrome c upon its binding to cardiolipin-containing small unilamellar vesicles. The measurements were performed as a function of the cardiolipin concentration, the cardiolipin content of the liposomes, and the NaCl concentration of the solvent. The data were analyzed with a novel model that combines a single binding step with a conformational equilibrium between native-like and non-native-like proteins bound to the membrane surface. The equilibrium between the two conformations, which themselves are comprised of structurally slightly different subconformations, shifts to the more non-native-like conformation with increasing cardiolipin concentration. For the binding isotherms described in this paper, we explicitly considered the enthalpic and entropic contributions of molecular crowding to protein binding at low lipid concentrations and high occupancy of the liposome surface. Increasing the CL content of liposomes increases the overall binding affinity but makes the conformational distribution much more susceptible to the influence of sodium and chloride ions, which shifts the equilibrium toward the more native-like state and directly inhibits binding, particularly to liposomes with 100% cardiolipin content. Spectroscopic evidence further suggests that a fraction of the non-native conformers adopts a pentacoordinated state similar to those obtained in class C peroxidases. On the basis of our results, we propose a hypothesis that describes the balance between facilitating and impeding forces controlling the peroxidase activity of cytochrome c in the inner membrane space of mitochondria.

  10. Projecting invasion risk of non-native watersnakes (Nerodia fasciata and Nerodia sipedon) in the western United States.

    Science.gov (United States)

    Rose, Jonathan P; Todd, Brian D

    2014-01-01

    Species distribution models (SDMs) are increasingly used to project the potential distribution of introduced species outside their native range. Such studies rarely explicitly evaluate potential conflicts with native species should the range of introduced species expand. Two snake species native to eastern North America, Nerodia fasciata and Nerodia sipedon, have been introduced to California where they represent a new stressor to declining native amphibians, fish, and reptiles. To project the potential distributions of these non-native watersnakes in western North America, we built ensemble SDMs using MaxEnt, Boosted Regression Trees, and Random Forests and habitat and climatic variables. We then compared the overlap between the projected distribution of invasive watersnakes and the distributions of imperiled native amphibians, fish, and reptiles that can serve as prey or competitors for the invaders, to estimate the risk to native species posed by non-native watersnakes. Large areas of western North America were projected to be climatically suitable for both species of Nerodia according to our ensemble SDMs, including much of central California. The potential distributions of both N. fasciata and N. sipedon overlap extensively with the federally threatened Giant Gartersnake, Thamnophis gigas, which inhabits a similar ecological niche. N. fasciata also poses risk to the federally threatened California Tiger Salamander, Ambystoma californiense, whereas N. sipedon poses risk to some amphibians of conservation concern, including the Foothill Yellow-legged Frog, Rana boylii. We conclude that non-native watersnakes in California can likely inhabit ranges of several native species of conservation concern that are expected to suffer as prey or competing species for these invaders. Action should be taken now to eradicate or control these invasions before detrimental impacts on native species are widespread. Our methods can be applied broadly to quantify the risk posed by

  11. Projecting invasion risk of non-native watersnakes (Nerodia fasciata and Nerodia sipedon in the western United States.

    Directory of Open Access Journals (Sweden)

    Jonathan P Rose

    Full Text Available Species distribution models (SDMs are increasingly used to project the potential distribution of introduced species outside their native range. Such studies rarely explicitly evaluate potential conflicts with native species should the range of introduced species expand. Two snake species native to eastern North America, Nerodia fasciata and Nerodia sipedon, have been introduced to California where they represent a new stressor to declining native amphibians, fish, and reptiles. To project the potential distributions of these non-native watersnakes in western North America, we built ensemble SDMs using MaxEnt, Boosted Regression Trees, and Random Forests and habitat and climatic variables. We then compared the overlap between the projected distribution of invasive watersnakes and the distributions of imperiled native amphibians, fish, and reptiles that can serve as prey or competitors for the invaders, to estimate the risk to native species posed by non-native watersnakes. Large areas of western North America were projected to be climatically suitable for both species of Nerodia according to our ensemble SDMs, including much of central California. The potential distributions of both N. fasciata and N. sipedon overlap extensively with the federally threatened Giant Gartersnake, Thamnophis gigas, which inhabits a similar ecological niche. N. fasciata also poses risk to the federally threatened California Tiger Salamander, Ambystoma californiense, whereas N. sipedon poses risk to some amphibians of conservation concern, including the Foothill Yellow-legged Frog, Rana boylii. We conclude that non-native watersnakes in California can likely inhabit ranges of several native species of conservation concern that are expected to suffer as prey or competing species for these invaders. Action should be taken now to eradicate or control these invasions before detrimental impacts on native species are widespread. Our methods can be applied broadly to quantify

  12. U.S. Airline Transport Pilot International Flight Language Experiences, Report 3: Language Experiences in Non-Native English-Speaking Airspace/Airports

    Science.gov (United States)

    2010-05-01

    MacKay, I., and Meador D. (2002). The production of English vowels by fluent early and late Italian- English bilinguals. Phonetica, 59:49- 71...U.S. Airline Transport Pilot International Flight Language Experiences, Report 3: Language Experiences in Non-Native English -Speaking Airspace...International Flight Language Experiences, Report 3: Language Experiences in Non-Native English -Speaking Airspace/Airports 6. Performing Organization Code

  13. Self-perceived oral communication competence in English, self-perceived employability and career expectations among non-native English speaking business professionals

    OpenAIRE

    Kuokka, Tiia

    2016-01-01

    Objective of the Study: The objectives for this thesis were 1) to understand non-native English speaking business professionals' self-perception of their oral communication competence in English, 2) to understand the importance of English language and competence in English for non-native English speaking business professionals when they consider employability and career expectations and finally 3) to study whether the concepts of self-perceived oral English communication competence, self-...

  14. Reasons for drop-out in rehabilitation treatment of native patients and non-native patients with chronic low back pain in the Netherlands: a medical file study.

    Science.gov (United States)

    Sloots, M; Dekker, J H M; Bartels, E A C; Geertzen, J H B; Dekker, J

    2010-12-01

    Drop-out of rehabilitation treatment in non-native patients with chronic low back pain has been reported to be higher than in native Dutch patients. It was expected that drop-out in non-native patients would be due to different expectations on the content of rehabilitation treatment and due to language or communication problems. Aim of this study was to determine differences in reasons for drop-out between native patients and non-native patients with chronic non-specific low back pain participating in a rehabilitation program. A retrospective study in medical files (N.=99) of patients who dropped out of treatment was performed in two rehabilitation centers and two rehabilitation departments of general hospitals. Patient files were checked for diagnosis, status of origin, gender, age and reason for drop-out. The differences in frequency in reasons for drop-out between native and non-native patients were tested by Chi-square tests. Withdrawal due to different expectations on the content of rehabilitation treatment occurred significantly more frequently in non-native patients (P=0.035). Withdrawal due to refusal to participate (no further reason given) occurred more often (P=0.008) in native Dutch patients than in non-native patients. No significant differences between non-native patients and native Dutch patients were reported regarding withdrawal due to language or communication problems, and no show (patient did not show up at consultation sessions without informing about the reason and without making an appointment for a new consultation). The present study provided evidence that drop-out in non-native patients is often related to different expectations regarding the content of rehabilitation treatment.

  15. Non-native and native organisms moving into high elevation and high latitude ecosystems in an era of climate change: new challenges for ecology and conservation

    Science.gov (United States)

    Pauchard, Aníbal; Albihn, Ann; Alexander, Jake; Burgess, Treena; Daehler, Curt; Essl, Franz; Evengard, Birgitta; Greenwood, Greg; Haider, Sylvia; Lenoir, Jonathan; McDougall, K.; Milbau, Ann; Muths, Erin L.; Nunez, Martin; Pellissier, Lois; Rabitsch, Wolfgang; Rew, Lisa; Robertson, Mark; Sanders, Nathan; Kueffer, Christoph

    2016-01-01

    Cold environments at high elevation and high latitude are often viewed as resistant to biological invasions. However, climate warming, land use change and associated increased connectivity all increase the risk of biological invasions in these environments. Here we present a summary of the key discussions of the workshop ‘Biosecurity in Mountains and Northern Ecosystems: Current Status and Future Challenges’ (Flen, Sweden, 1–3 June 2015). The aims of the workshop were to (1) increase awareness about the growing importance of species expansion—both non-native and native—at high elevation and high latitude with climate change, (2) review existing knowledge about invasion risks in these areas, and (3) encourage more research on how species will move and interact in cold environments, the consequences for biodiversity, and animal and human health and wellbeing. The diversity of potential and actual invaders reported at the workshop and the likely interactions between them create major challenges for managers of cold environments. However, since these cold environments have experienced fewer invasions when compared with many warmer, more populated environments, prevention has a real chance of success, especially if it is coupled with prioritisation schemes for targeting invaders likely to have greatest impact. Communication and co-operation between cold environment regions will facilitate rapid response, and maximise the use of limited research and management resources.

  16. SAR backscatter from coniferous forest gaps

    Science.gov (United States)

    Day, John L.; Davis, Frank W.

    1992-01-01

    A study is in progress comparing Airborne Synthetic Aperture Radar (AIRSAR) backscatter from coniferous forest plots containing gaps to backscatter from adjacent gap-free plots. Issues discussed are how do gaps in the range of 400 to 1600 sq m (approximately 4-14 pixels at intermediate incidence angles) affect forest backscatter statistics and what incidence angles, wavelengths, and polarizations are most sensitive to forest gaps. In order to visualize the slant-range imaging of forest and gaps, a simple conceptual model is used. This strictly qualitative model has led us to hypothesize that forest radar returns at short wavelengths (eg., C-band) and large incidence angles (e.g., 50 deg) should be most affected by the presence of gaps, whereas returns at long wavelengths and small angles should be least affected. Preliminary analysis of 1989 AIRSAR data from forest near Mt. Shasta supports the hypothesis. Current forest backscatter models such as MIMICS and Santa Barbara Discontinuous Canopy Backscatter Model have in several cases correctly predicted backscatter from forest stands based on inputs of measured or estimated forest parameters. These models do not, however, predict within-stand SAR scene texture, or 'intrinsic scene variability' as Ulaby et al. has referred to it. For instance, the Santa Barbara model, which may be the most spatially coupled of the existing models, is not truly spatial. Tree locations within a simulated pixel are distributed according to a Poisson process, as they are in many natural forests, but tree size is unrelated to location, which is not the case in nature. Furthermore, since pixels of a simulated stand are generated independently in the Santa Barbara model, spatial processes larger than one pixel are not modeled. Using a different approach, Oliver modeled scene texture based on an hypothetical forest geometry. His simulated scenes do not agree well with SAR data, perhaps due to the simple geometric model used. Insofar as texture

  17. The influence of visual speech information on the intelligibility of English consonants produced by non-native speakers.

    Science.gov (United States)

    Kawase, Saya; Hannah, Beverly; Wang, Yue

    2014-09-01

    This study examines how visual speech information affects native judgments of the intelligibility of speech sounds produced by non-native (L2) speakers. Native Canadian English perceivers as judges perceived three English phonemic contrasts (/b-v, θ-s, l-ɹ/) produced by native Japanese speakers as well as native Canadian English speakers as controls. These stimuli were presented under audio-visual (AV, with speaker voice and face), audio-only (AO), and visual-only (VO) conditions. The results showed that, across conditions, the overall intelligibility of Japanese productions of the native (Japanese)-like phonemes (/b, s, l/) was significantly higher than the non-Japanese phonemes (/v, θ, ɹ/). In terms of visual effects, the more visually salient non-Japanese phonemes /v, θ/ were perceived as significantly more intelligible when presented in the AV compared to the AO condition, indicating enhanced intelligibility when visual speech information is available. However, the non-Japanese phoneme /ɹ/ was perceived as less intelligible in the AV compared to the AO condition. Further analysis revealed that, unlike the native English productions, the Japanese speakers produced /ɹ/ without visible lip-rounding, indicating that non-native speakers' incorrect articulatory configurations may decrease the degree of intelligibility. These results suggest that visual speech information may either positively or negatively affect L2 speech intelligibility.

  18. Home range use and movement patterns of non-native feral goats in a tropical island montane dry landscape.

    Directory of Open Access Journals (Sweden)

    Mark W Chynoweth

    Full Text Available Advances in wildlife telemetry and remote sensing technology facilitate studies of broad-scale movements of ungulates in relation to phenological shifts in vegetation. In tropical island dry landscapes, home range use and movements of non-native feral goats (Capra hircus are largely unknown, yet this information is important to help guide the conservation and restoration of some of the world's most critically endangered ecosystems. We hypothesized that feral goats would respond to resource pulses in vegetation by traveling to areas of recent green-up. To address this hypothesis, we fitted six male and seven female feral goats with Global Positioning System (GPS collars equipped with an Argos satellite upload link to examine goat movements in relation to the plant phenology using the Normalized Difference Vegetation Index (NDVI. Movement patterns of 50% of males and 40% of females suggested conditional movement between non-overlapping home ranges throughout the year. A shift in NDVI values corresponded with movement between primary and secondary ranges of goats that exhibited long-distance movement, suggesting that vegetation phenology as captured by NDVI is a good indicator of the habitat and movement patterns of feral goats in tropical island dry landscapes. In the context of conservation and restoration of tropical island landscapes, the results of our study identify how non-native feral goats use resources across a broad landscape to sustain their populations and facilitate invasion of native plant communities.

  19. Application of Native Speaker Models for Identifying Deviations in Rhetorical Moves in Non-Native Speaker Manuscripts

    Directory of Open Access Journals (Sweden)

    Assef Khalili

    2016-06-01

    Full Text Available Introduction: Explicit teaching of generic conventions of a text genre, usually extracted from native-speaker (NS manuscripts, has long been emphasized in the teaching of Academic Writing inEnglish for Specific Purposes (henceforthESP classes, both in theory and practice. While consciousness-raising about rhetorical structure can be instrumental to non-native speakers(NNS, it has to be admitted that most works done in the field of ESP have tended to focus almost exclusively on native-speaker (NS productions, giving scant attention to non-native speaker (NNS manuscripts. That is, having outlined established norms for good writing on the basis of NS productions, few have been inclined to provide a descriptive account of NNS attempts at trying to produce a research article (RA in English. That is what we have tried to do in the present research. Methods: We randomly selected 20 RAs in dentistry and used two well-established models for results and discussion sections to try to describe the move structure of these articles and show the points of divergence from the established norms. Results: The results pointed to significant divergences that could seriously compromise the quality of an RA. Conclusion: It is believed that the insights gained on the deviations in NNS manuscripts could prove very useful in designing syllabi for ESP classes.

  20. Morphological change and phenotypic plasticity in native and non-native pumpkinseed sunfish in response to competition

    Science.gov (United States)

    Yavno, Stan; Rooke, Anna C.; Fox, Michael G.

    2014-06-01

    Non-indigenous species are oftentimes exposed to ecosystems with unfamiliar species, and organisms that exhibit a high degree of phenotypic plasticity may be better able to contend with the novel competitors that they may encounter during range expansion. In this study, differences in morphological plasticity were investigated using young-of-year pumpkinseed sunfish ( Lepomis gibbosus) from native North American and non-native European populations. Two Canadian populations, isolated from bluegill sunfish ( L. macrochirus) since the last glaciation, and two Spanish populations, isolated from bluegill since their introduction in Europe, were reared in a common environment using artificial enclosures. Fish were subjected to allopatric (without bluegill) or sympatric (with bluegill) conditions, and differences in plasticity were tested through a MANOVA of discriminant function scores. All pumpkinseed populations exhibited dietary shifts towards more benthivorous prey when held with bluegill. Differences between North American and European populations were observed in body dimensions, gill raker length and pelvic fin position. Sympatric treatments induced an increase in body width and a decrease in caudal peduncle length in native fish; non-native fish exhibited longer caudal peduncle lengths when held in sympatry with bluegill. Overall, phenotypic plasticity influenced morphological divergence less than genetic factors, regardless of population. Contrary to predictions, pumpkinseeds from Europe exhibited lower levels of phenotypic plasticity than Canadian populations, suggesting that European pumpkinseeds are more canalized than their North American counterparts.

  1. Morphological change and phenotypic plasticity in native and non-native pumpkinseed sunfish in response to sustained water velocities.

    Science.gov (United States)

    Yavno, S; Fox, M G

    2013-11-01

    Phenotypic plasticity can contribute to the proliferation and invasion success of nonindigenous species by promoting phenotypic changes that increase fitness, facilitate range expansion and improve survival. In this study, differences in phenotypic plasticity were investigated using young-of-year pumpkinseed sunfish from colonies established with lentic and lotic populations originating in Canada (native) and Spain (non-native). Individuals were subjected to static and flowing water treatments for 80 days. Inter- and intra-population differences were tested using ancova and discriminant function analysis, and differences in phenotypic plasticity were tested through a manova of discriminant function scores. Differences between Iberian and North American populations were observed in dorsal fin length, pectoral fin position and caudal peduncle length. Phenotypic plasticity had less influence on morphology than genetic factors, regardless of population origin. Contrary to predictions, Iberian pumpkinseed exhibited lower levels of phenotypic plasticity than native populations, suggesting that canalization may have occurred in the non-native populations during the processes of introduction and range expansion.

  2. An event-related potential study of visual rhyming effects in native and non-native English speakers.

    Science.gov (United States)

    Botezatu, Mona R; Miller, Carol A; Misra, Maya

    2015-02-11

    English monolinguals and highly proficient, but first language (L1)-dominant, Spanish-English and Chinese-English bilinguals made rhyme judgments of visually presented English word pairs while behavioral and EEG measures were being recorded. Two types of conditions were considered: rhyming and nonrhyming pairs that were orthographically dissimilar (e.g. white-fight, child-cough) and those that were orthographically similar (e.g. right-fight, dough-cough). Both native and non-native English speakers were faster and more accurate in responding to nonrhyming than rhyming targets under orthographically dissimilar conditions, although the response times of Chinese-English bilinguals differed from those of the other groups. All groups were slower and less accurate in responding to nonrhyming targets under orthographically similar conditions, with the response times and accuracy rates of Spanish-English bilinguals differing from those of the other groups. All participant groups showed more negative N450 mean amplitudes to nonrhyming compared with rhyming targets, regardless of orthographic similarity, and this rhyming effect did not differ across groups under the orthographically similar conditions. However, under orthographically dissimilar conditions, the rhyming effect was less robust in non-native speakers, being modulated by English proficiency.

  3. Soil moisture patterns in a northern coniferous forest

    Science.gov (United States)

    Thomas F. McLintock

    1959-01-01

    The trend of soil moisture during the growing season, the alternate wetting from rainfall and drying during clear weather, determines the amount of moisture available for tree growth and also fixes, in part, the environment for root growth. In much of the northern coniferous region both moisture content and root environment are in turn affected by the hummock-and-...

  4. 75 FR 55736 - Mark Twain National Forest; Missouri; Integrated Non-Native Invasive Plant Project

    Science.gov (United States)

    2010-09-14

    ... proposal utilizes several management tools, including registered herbicides, bio-agents, and manual... herbicide or release of bio- agents. The application of herbicide could result in an increase of toxic...

  5. Integrating early detection with DNA barcoding: species identification of a non-native monitor lizard (Squamata: Varanidae) carcass in Mississippi, U.S.A.

    Science.gov (United States)

    Reed, Robert N.; Hopken, Matthew W.; Steen, David A.; Falk, Bryan G.; Piaggio, Antoinette J.

    2016-01-01

    Early detection of invasive species is critical to increasing the probability of successful management. At the primary stage of an invasion, invasive species are easier to control as the population is likely represented by just a few individuals. Detection of these first few individuals can be challenging, particularly if they are cryptic or otherwise characterized by low detectability. The engagement of members of the public may be critical to early detection as there are far more citizen s on the landscape than trained biologists. However, it can be difficult to assess the credibility of public reporting, especially when a diagnostic digital image or a physical specimen in good condition are lacking. DNA barcoding can be used for verification when morphological identification of a specimen is not possible or uncertain (i.e., degraded or partial specimen). DNA barcoding relies on obtaining a DNA sequence from a relatively small fragment of mitochondrial DNA and comparing it to a database of sequences containing a variety of expertly identified species. He rein we report the successful identification of a degraded specimen of a non-native, potentially invasive reptile species (Varanus niloticus) via DNA barcoding, after discovery and reporting by a member of the public.

  6. Designing acoustics for linguistically diverse classrooms: Effects of background noise, reverberation and talker foreign accent on speech comprehension by native and non-native English-speaking listeners

    Science.gov (United States)

    Peng, Zhao Ellen

    The current classroom acoustics standard (ANSI S12.60-2010) recommends core learning spaces not to exceed background noise level (BNL) of 35 dBA and reverberation time (RT) of 0.6 second, based on speech intelligibility performance mainly by the native English-speaking population. Existing literature has not correlated these recommended values well with student learning outcomes. With a growing population of non-native English speakers in American classrooms, the special needs for perceiving degraded speech among non-native listeners, either due to realistic room acoustics or talker foreign accent, have not been addressed in the current standard. This research seeks to investigate the effects of BNL and RT on the comprehension of English speech from native English and native Mandarin Chinese talkers as perceived by native and non-native English listeners, and to provide acoustic design guidelines to supplement the existing standard. This dissertation presents two studies on the effects of RT and BNL on more realistic classroom learning experiences. How do native and non-native English-speaking listeners perform on speech comprehension tasks under adverse acoustic conditions, if the English speech is produced by talkers of native English (Study 1) versus native Mandarin Chinese (Study 2)? Speech comprehension materials were played back in a listening chamber to individual listeners: native and non-native English-speaking in Study 1; native English, native Mandarin Chinese, and other non-native English-speaking in Study 2. Each listener was screened for baseline English proficiency level, and completed dual tasks simultaneously involving speech comprehension and adaptive dot-tracing under 15 acoustic conditions, comprised of three BNL conditions (RC-30, 40, and 50) and five RT scenarios (0.4 to 1.2 seconds). The results show that BNL and RT negatively affect both objective performance and subjective perception of speech comprehension, more severely for non-native

  7. Talk About Mouth Speculums: Collocational Competence and Spoken Fluency in Non-Native English-Speaking University Lecturers

    DEFF Research Database (Denmark)

    Westbrook, Pete

    Despite the large body of research into formulaic language and fluency, there seems to be a lack of empirical evidence for how collocations, often considered a subset of formulaic language, might impact on fluency. To address this problem, this dissertation examined to what extent correlations...... might exist between overall language proficiency, collocational competence and spoken fluency in non-native English-speaking university lecturers. The data came from 15 20-minute mini-lectures recorded between 2009 and 2011 for an English oral proficiency test for lecturers employed at the University...... of Copenhagen. The 15 lecturers came from three departments: Large Animal Science, Information Technology and Mathematics. Test examiners’ global and fluency scores from the test were analysed against collocational competence, measured as collocations produced per thousand words spoken, and three temporal...

  8. Effects of a non-native cichlid fish (African jewelfish, Hemichromis letourneuxi Sauvage 1880) on a simulated Everglades aquatic community

    Science.gov (United States)

    Schofield, Pamela J.; Slone, Daniel H.; Gregoire, Denise R.; Loftus, William F.

    2014-01-01

    In an 8-month mesocosm experiment, we examined how a simulated Everglades aquatic community of small native fishes, snails, and shrimp changed with the addition of either a native predator (dollar sunfish Lepomis marginatus) or a non-native predator (African jewelfish Hemichromis letourneuxi) compared to a no-predator control. Two snail species (Planorbella duryi, Physella cubensis) and the shrimp (Palaemonetes paludosus) displayed the strongest predator-treatment effects, with significantly lower biomasses in tanks with Hemichromis. One small native fish (Heterandria formosa) was significantly less abundant in Hemichromis tanks, but there were no significant treatment effects for Gambusia holbrooki, Jordanella floridae, or Pomacea paludosa (applesnail). Overall, there were few treatment differences between native predator and no-predator control tanks. The results suggest that the potential of Hemichromis to affect basal food-web species that link primary producers with higher-level consumers in the aquatic food web, with unknown consequences for Florida waters.

  9. Interactions between non-native armored suckermouth catfish (Loricariidae: Pterygoplichthys) and native Florida manatee (Trichechus manatus latirostris) in artesian springs

    Science.gov (United States)

    Nico, Leo G.; Loftus, William F.; Reid, James P.

    2009-01-01

    Non-native suckermouth armored catfishes (Loricariidae) of the genus Pterygoplichthys are now common throughout much of peninsular Florida. In this paper, we present preliminary observations on interactions between a Pterygoplichthys species, tentatively identified as P. disjunctivus (Weber, 1991), and endangered native Florida manatees, Trichechus manatus latirostris (Harlan, 1824), in artesian spring systems in Florida's St. Johns River drainage. The introduced catfish have become abundant in spring habitats, sites used by manatees as winter thermal refuges. In the spring runs, Pterygoplichthys regularly attaches to manatees and grazes the epibiota on their skin. On occasion, dozens of Pterygoplichthys congregate on individual manatees. Manatee responses varied widely; some did not react visibly to attached catfish whereas others appeared agitated and attempted to dislodge the fish. The costs and/or benefits of this interaction to manatees remain unclear.

  10. THE ACQUISITION OF ENGLISH NEGATION 'NO' AND 'NOT': EVIDENCES FROM AN INDONESIAN CHILD IN NON-NATIVE PARENTS BILINGUAL PROGRAM

    Directory of Open Access Journals (Sweden)

    Anni Holila Pulungan

    2003-01-01

    Full Text Available Every child is born with an innate endowment by which (a language(s acquisition is possible. This view emphasizes the role of universal properties every child is born with to acquire (a language(s. This paper presents the acquisition of English negation 'no' and 'not' by an Indonesian child brought up in Indonesian - English Non-native Parents Bilingual Program (NPBP. The analysis is directed to reveal the pattern of 'no' and 'not' use as the evidence that a child still acquires a targeted language despite the poor targeted language input s/he is exposed to. The result of the analysis shows that the acquisition of English negation 'no' and 'not' by an Indonesian child in Indonesian - English NPBP also has a pattern which falls into syntactic, semantic, and pragmatic cases. To some extent, it supports Universal Grammar frame, but there are some which provide new insights on this issue.

  11. A COMPARISON OF ORAL EVALUATION RATINGS BY NATIVE ENGLISH SPEAKER TEACHERS AND NON-NATIVE ENGLISH SPEAKER TEACHERS

    Directory of Open Access Journals (Sweden)

    Brittany Baitman

    2013-01-01

    Full Text Available This study attempts to explore the differences and similarities between native English speaker (NES teachers and non-native English speaker (NNES teachers in their oral evaluation ratings of the same university level English language learners. To this effect, the iBT/Next Generation TOEFL Test Independent Speaking Rubric and a questionnaire were employed. The results reveal that NES teachers are more lenient in their oral evaluation ratings than NNES teachers. In regards to the questionnaire employed, it was found that NES teachers take into consideration the aspects of fluency and pronunciation more so than NNES teachers when orally assessing students, while NNES teachers take more into consideration the aspects of grammatical accuracy and vocabulary. Further research is required in the area of oral assessment specifically pertaining to nationality, age, work experience, and knowledge of a second language.

  12. Effectiveness of backpack electrofishing for removal of non-native fishes from a small warm-water stream

    Science.gov (United States)

    Ward, David L.; O'neill, Matthew W.; Ka'apu-Lyons, Cassie

    2015-01-01

    Electrofishing is commonly used when renovating small streams to remove nuisance fishes but the likelihood of complete eradication of unwanted species, particularly warm-water fishes, is unknown. In October of 2008, we electrofished Bonita Creek, a small stream with base flows (<0.56 m3/s) in southern Arizona, and then treated the stream with rotenone to kill all of the remaining fish and quantify the effectiveness of single and multiple-pass electro fishing. Six, 100-m transects were electro fished on three consecutive days followed by a single treatment with rotenone. Fish caught using electrofishing were identified, counted and removed from each transect daily and then compared to numbers of dead fish collected during the subsequent rotenone application. Electrofishing effectiveness was highly variable among transects. Single-pass electrofishing caught an average of 23% (95% CI=5 to 40%) of the fish present, and three-pass electrofishing on consecutive days caught on average 55% (95% CI=28 to 83%) of the fish in each transect. Native Arizona fishes were more susceptible to electrofishing (77 % captured) than non-native species (54% captured), though native fish were rare. Transects in Bonita Creek averaged 3.6±1.5 m wide and 0.25±0.20 m deep (max depth 1.2 m). Bonita Creek is a small first-order stream which exhibits ideal conditions for backpack electrofishing, yet we captured a relatively small percentage of the fish present. This suggests that complete removal of non-native warm-water fishes using backpack electrofishing is not likely to be successful, especially in larger more complex streams.

  13. Use of multifactorial analysis to develop aqueous two-phase systems for isolation of non-native IGF-I.

    Science.gov (United States)

    Hart, R A; Ogez, J R; Builder, S E

    1995-04-01

    A high yield procedure was developed to solubilize and extract IGF-I from recombinant E. coli by adding chaotrope and disulfide reductant to alkaline fermentation broth. To enhance centrifugation performance and recovery yield, a salt/polymer aqueous two-phase extraction procedure was developed whereby soluble non-native IGF-I and biomass solids are enriched in separate liquid phases. To develop this extraction system a multifactorial experimental approach was used to simultaneously map the phase diagram and identify conditions to suitably partition IGF-I and cell remnants. The presence of urea in these systems tended to disrupt two-phase formation and solids sedimentation. This, in turn, constrained the concentrations of phase forming solutes which could be effectively used. Systems containing low levels of salt (less than about 4% w/w) and polymer (less than about 10% w/w) did not form two phases. Systems containing high levels of salt (greater than about 7% w/w) and polymer (greater than about 18% w/w) formed two phases with floating solids. Intermediate levels of salt (between about 4% and 7% w/w) and polymer (between about 10% and 18% w/w) formed two phases in which solids were enriched in the heavy phase. Systems in this latter desired category were produced with a variety of different salts and polymers and all enriched non-native IGF-I in the light phase. Highest recovery yield (about 90%) was obtained with systems composed of 5% sodium sulfate and 14% PEG-8000.(ABSTRACT TRUNCATED AT 250 WORDS)

  14. Influence of Removal of a Non-native Tree Species Mimosa caesalpiniifolia Benth. on the Regenerating Plant Communities in a Tropical Semideciduous Forest Under Restoration in Brazil

    Science.gov (United States)

    Podadera, Diego S.; Engel, Vera L.; Parrotta, John A.; Machado, Deivid L.; Sato, Luciane M.; Durigan, Giselda

    2015-11-01

    Exotic species are used to trigger facilitation in restoration plantings, but this positive effect may not be permanent and these species may have negative effects later on. Since such species can provide a marketable product (firewood), their harvest may represent an advantageous strategy to achieve both ecological and economic benefits. In this study, we looked at the effect of removal of a non-native tree species ( Mimosa caesalpiniifolia) on the understory of a semideciduous forest undergoing restoration. We assessed two 14-year-old plantation systems (modified "taungya" agroforestry system; and mixed plantation using commercial timber and firewood tree species) established at two sites with contrasting soil properties in São Paulo state, Brazil. The experimental design included randomized blocks with split plots. The natural regeneration of woody species (height ≥0.2 m) was compared between managed (all M. caesalpiniifolia trees removed) and unmanaged plots during the first year after the intervention. The removal of M. caesalpiniifolia increased species diversity but decreased stand basal area. Nevertheless, the basal area loss was recovered after 1 year. The management treatment affected tree species regeneration differently between species groups. The results of this study suggest that removal of M. caesalpiniifolia benefited the understory and possibly accelerated the succession process. Further monitoring studies are needed to evaluate the longer term effects on stand structure and composition. The lack of negative effects of tree removal on the natural regeneration indicates that such interventions can be recommended, especially considering the expectations of economic revenues from tree harvesting in restoration plantings.

  15. The effect of input source (Native vs. Non- native and EFL learners’ perceptions towards it, on their listening performances, across gender

    Directory of Open Access Journals (Sweden)

    Karim Sadeghi

    2014-07-01

    Full Text Available The issue of the “native/non-native speaker’s input source” occupies an important place in any EFL listening comprehension test. This study is meant to unveil whether listening to a native or non-native speaker (i.e., input source and students’ perceptions towards it affect the performance of upper-intermediate EFL learners in a listening test. For this purpose, an experimental design was used to compare the performance of two groups of learners on an EFL listening test. A test of 20 multiple choice items was administered to 66 EFL learners (31 male and 35 female, half of whom listened to a native speaker’s voice while the other 33 test takers listened to a non-native speaker’s voice. Moreover, a perception questionnaire considering students’ perceptions towards using native or non-native input source in listening tests was utilized. The results of the study highlighted that the overall performance of the two groups differed significantly. That is, the listeners to the non-native input outperformed those who listened to a native speaker. Also, the results of the questionnaire revealed some noteworthy findings which indicate that students preferred the use of non-native input in listening tests. Moreover, considering gender as a moderator variable, a statistically significant main effect was found for gender; that is, gender does play a significant role as a moderator variable. In other words, female test takers performed better than males in both conditions. Further findings and implications are discussed in the paper.

  16. Increased potential for wound activated production of Prostaglandin E2 and related toxic compounds in non-native populations of Gracilaria vermiculophylla.

    Science.gov (United States)

    Hammann, Mareike; Rempt, Martin; Pohnert, Georg; Wang, Gaoge; Boo, Sung Min; Weinberger, Florian

    2016-01-01

    The capacity of the East Asian seaweed Gracilaria vermiculophylla ("Ogonori") for production of prostaglandin E2 from arachidonic acid occasionally causes food poisoning after ingestion. During the last two decades the alga has been introduced to Europe and North America. Non-native populations have been shown to be generally less palatable to marine herbivores than native populations. We hypothesized that the difference in palatability among populations could be due to differences in the algal content of prostaglandins. We therefore compared the capacity for wound-activated production of prostaglandins and other eicosatetraenoid oxylipins among five native populations in East Asia and seven non-native populations in Europe and NW Mexico, using a targeted metabolomics approach. In two independent experiments non-native populations exhibited a significant tendency to produce more eicosatetraenoids than native populations after acclimation to identical conditions and subsequent artificial wounding. Fourteen out of 15 eicosatetraenoids that were detected in experiment I and all 19 eicosatetraenoids that were detected in experiment II reached higher mean concentrations in non-native than in native specimens. Wounding of non-native specimens resulted on average in 390% more 15-keto-PGE2, in 90% more PGE2, in 37% more PGA2 and in 96% more 7,8-di-hydroxy-eicosatetraenoic acid than wounding of native specimens. Not only PGE2, but also PGA2 and dihydroxylated eicosatetraenoic acid are known to deter various biological enemies of G. vermiculophylla that cause tissue or cell wounding, and in the present study the latter two compounds also repelled the mesograzer Littorina brevicula. Non-native populations of G. vermiculophylla are thus more defended against herbivory than native populations. This increased capacity for activated chemical defense may have contributed to their invasion success and at the same time it poses an elevated risk for human food safety.

  17. Non-native freshwater fishes in the Iberian Southeast: black list and potential impacts

    Directory of Open Access Journals (Sweden)

    Fátima Amat-Trigo

    2015-10-01

    At least, sixteen species had been introduced the Southeast Iberian by the beginning of the 20th century, but the rate of introduction is highly elevated in the last two decades, with the majority of introductions since 2000. Most studies reviewed reported only potential impacts. Failed introductions are poorly documented and existing information is scattered in regional publications, reports and other grey literature. Due to the interbasin water transfers (Tajo-Segura channel, the number of translocated species is high, however, information about these fishes is not regarded by researchers and their potential impacts are neglected. We established a black list with sixteen cited species and nineteen potential invasive species. Additionally, research needs and management priority measures are evaluated.

  18. Assessing the Performance of Automatic Speech Recognition Systems When Used by Native and Non-Native Speakers of Three Major Languages in Dictation Workflows

    DEFF Research Database (Denmark)

    Zapata, Julián; Kirkedal, Andreas Søeborg

    2015-01-01

    In this paper, we report on a two-part experiment aiming to assess and compare the performance of two types of automatic speech recognition (ASR) systems on two different computational platforms when used to augment dictation workflows. The experiment was performed with a sample of speakers...... of three major languages and with different linguistic profiles: non-native English speakers; non-native French speakers; and native Spanish speakers. The main objective of this experiment is to examine ASR performance in translation dictation (TD) and medical dictation (MD) workflows without manual...

  19. Evaluating detection and monitoring tools for incipient and relictual non-native ungulate populations

    Science.gov (United States)

    Judge, Seth W.; Hess, Steve; Faford, Jonathan K.J.; Pacheco, Dexter; Leopold, Christina R.; Cole, Colleen; Deguzman, Veronica

    2016-01-01

    Hawai‘i Volcanoes National Park (HAVO) encompasses 1,308 km2 on Hawai‘i Island. The park harbors endemic plants and animals which are threatened by a variety of invasive species. Introduced ungulates have caused sharp declines of numerous endemic species and have converted ecosystems to novel grazing systems in many cases. Local ranchers and the Territorial Government of Hawai‘i had long conducted regional ungulate control even prior to the establishment of HAVO in 1916. In 1995 the park’s hunting team began a new hunt database that allowed managers to review hunt effort and effectiveness in each management unit. Target species included feral pigs (Sus scrofa), European mouflon sheep (Ovis gmelini musimon), feral goats (Capra hircus) and wild cattle (Bos taurus). Hunters removed 1,204 feral pigs from HAVO over a 19-year period (1996‒2014). A variety of methods were employed, but trapping, snaring and ground hunts with dogs accounted for the most kills. Trapping yielded the most animals per unit effort. Hunters and volunteers removed 6,657 mouflon from HAVO; 6,601 of those were from the 468 km2 Kahuku Unit. Aerial hunts yielded the most animals followed by ground hunt methods. Hunters completed eradications of goats in several management units over an 18- year period (1997‒2014) when they removed the last 239 known individuals in HAVO primarily with aerial hunts. There have also been seven cattle and five feral dogs (Canis familiaris) removed from HAVO. Establishing benchmarks and monitoring the success of on-the-ground ungulate removal efforts can improve the efficiency of protecting and restoring native forest for high-priority watersheds and native wildlife. We tested a variety of methods to detect small populations of ungulates within HAVO and the Hō‘ili Wai study area in the high-priority watershed of Ka‘ū Forest Reserve on Hawai‘i Island. We conducted ground surveys, aerial surveys and continuous camera trap monitoring in both fence

  20. Sediment composition mediates the invasibility of aquatic ecosystems by a non-native Poaceae species

    Directory of Open Access Journals (Sweden)

    José Vitor Botter Fasoli

    2015-06-01

    Full Text Available Aim: To test the invasibility of aquatic ecosystems by an exotic species, we used the invasive macrophyte Urochloa arrecta, which has invaded many Neotropical waterbodies and has reduced biodiversity in these habitats. The extensive growth of this macrophyte can be related to its affinity for mud-rich sediments, which occur primarily in secondary river channels and lentic habitats.MethodsTo test this hypothesis, we cultivated U. arrecta in trays with different percentages of mud and we measured the sprout length and biomass of the plants after 75 days.ResultsOur results showed a positive and significant relationship between sediment mud percentage and nitrogen, phosphorus and organic matter. Both plant length and biomass increased significantly and continuously with increasing mud content, indicating that the growth of this species is not limited even at the highest levels of mud, which is shown to be toxic for other species of macrophytes. Thus, it is probable that sand-rich sites, such as river shores, are less vulnerable to invasion by this species than relatively mud-rich sites, such as lakes.ConclusionsThis finding indicates that relatively mud-rich ecosystems should be prioritised in monitoring programs to prevent invasion by this species. In addition, the slow development of this species in sandy sediments opens a potential window for its management, at least on small spatial scales. However, despite the reduced growth of U. arrecta in sand-rich sediments, this grass is able to grow in several types of sediments, which explains its spread in a variety of habitats in Neotropical freshwater ecosystems.

  1. Application of FISK, an invasiveness screening tool for non-native freshwater fishes, in the Murray-Darling Basin (southeastern Australia).

    Science.gov (United States)

    Vilizzi, Lorenzo; Copp, Gordon H

    2013-08-01

    The Fish Invasiveness Scoring Kit (FISK) is currently one of the most popular pre-screening tools for freshwater fishes. A recent upgrade has ensured its wider climatic relevance to countries with subtropical regions. This enhancement is of particular importance to Australia, which encompasses tropical, arid, and temperate zones, and where the introduction of non-native fish species poses a significant risk to biodiversity. In this study, 55 fish species previously evaluated in a U.K.-based calibration of FISK are reassessed for their potential invasiveness in the Murray-Darling Basin (MDB; southeastern Australia), the continent's largest catchment encompassing arid and temperate climates. Approximately half of the species were classed as "medium risk" and the other half as "high risk," and the ≥19 threshold previously identified from the calibration study was confirmed. The three highest scoring species (common carp Cyprinus carpio carpio, goldfish Carassius auratus, and eastern mosquitofish Gambusia holbrooki) were those already present and invasive in the area, whereas nearly half of the tropical and subtropical species had lower scores compared to U.K. assessments, possibly because of climate change predictions of drier conditions across the MDB. There were some discordances between FISK and two Australian-based assessment protocols, one of which is qualitative and the other represents a simplified version of FISK. Notably, the Australian origins of FISK should provide for an additional reason for further applications of the tool in other RA areas (i.e., drainage basins) of the continent, ultimately encouraging adoption as the country's reference screening tool for management and conservation purposes.

  2. 76 FR 72436 - Draft Environmental Impact Statement for Protecting and Restoring Native Ecosystems by Managing...

    Science.gov (United States)

    2011-11-23

    ...; 2310-0057-422] Draft Environmental Impact Statement for Protecting and Restoring Native Ecosystems by... Restoring Native Ecosystems by Managing Non-Native Ungulates. SUMMARY: The National Park Service (NPS... Restoring Native Ecosystems by Managing Non-Native Ungulates, Hawaii Volcanoes National Park, Hawaii. The...

  3. Are eavesdroppers multimodal?Sensory exploitation of floral signals by a non-native cockroach Blatta orientalis

    Institute of Scientific and Technical Information of China (English)

    Rodrigo C.VERGARA; Alejandra TORRES-ARANEDA; Diego A.VILLAGRA; Robert A.RAGUSO; Mary T.K.ARROYO; Cristian A.BILLAGRA

    2011-01-01

    The study of multi-modal communication has only recently been extended to innate and learned interactions between flowers and their animal visitors,and usually only to pollinators.Here we studied the relevance of floral scent and visual display of a night blooming,putatively hawkmoth-poilinated plant Oenothera acaulis(Onagraceae)in the attraction of non-native cockroaches Blatta orientalis(Blattodea:Blattldae),which function as facultative floral lajrcenists in coastal habitats of central Chile.We experimentally decoupled visual(corolla)and olfactory(fragrance)stimuli by presentlng paper corollas and green mesh bags,with or without a freshly-picked natural flower inside.We then contrasted the behavioral responses of roaches in these treatments with those to the natural combination of traits in actual flowers and their respective control treatments,measuring the roaches'frequency of first visits,mean and total residence time spent in each treatment.The roaches primarily used olfactory cues when approaching O.acaulis flowers at two biologically relevant spatial scaies.In addition,the presence of conspecific roaches bad a strong influence on recruitment to the expenrnental arena,increasing the statlstical differences among treatments.Our results suggest a primacy of floral fragrance over visual stimuli in the foraging responses of B.orientalis.Olfactory cues were necessary and sufficient to attract the roaches,and the visual cues presented in our manipulations only marginally increased their attraction within a 20 cm diameter of the stimulus.The full spectrum of floral visitation behavior was not elicited by the artlficial flowers,suggesting the need for addltional tactile or contact chemosensory stimuli not provided by paper.Although the nitrogenous scent compounds that we found in O.acaulis flowers are almost exclusively found in hawkmoth-pollinated flowers,the attractiveness of these compounds to a non-native,facultative flower-visiting insect indicates that they

  4. Toward a Composite, Personalized, and Institutionalized Teacher Identity for Non-Native English Speakers in U.S. Secondary ESL Programs

    Science.gov (United States)

    Huang, I-Chen; Varghese, Manka M.

    2015-01-01

    Research in English language teaching and teacher identity has increasingly focused on understanding non-native English-speaking teachers. In addition, much of this research has been conducted in adult English as a second language (ESL) settings. Through a multiple-case qualitative study of four teachers in an underexplored research setting--that…

  5. Non-native plants and soil microbes: potential contributors to the consistent reduction in soil aggregate stability caused by the disturbance of North American grasslands.

    Science.gov (United States)

    Duchicela, Jessica; Vogelsang, Keith M; Schultz, Peggy A; Kaonongbua, Wittaya; Middleton, Elizabeth L; Bever, James D

    2012-10-01

    • Soil aggregate stability is an important ecosystem property that is altered by anthropogenic disturbance. Yet, the generalization of these alterations and the identification of the main contributors are limited by the absence of cross-site comparisons and the application of inconsistent methodologies across regions. • We assessed aggregate stability in paired remnant and post-disturbance grasslands across California, shortgrass and tallgrass prairies, and in manipulative experiments of plant composition and soil microbial inoculation. • Grasslands recovering from anthropogenic disturbance consistently had lower aggregate stability than remnants. Across all grasslands, non-native plant diversity was significantly associated with reduced soil aggregate stability. A negative effect of non-native plants on aggregate stability was also observed in a mesocosm experiment comparing native and non-native plants from California grasslands. Moreover, an inoculation study demonstrated that the degradation of the microbial community also contributes to the decline in soil aggregate stability in disturbed grasslands. • Anthropogenic disturbance consistently reduced water-stable aggregates. The stability of aggregates was reduced by non-native plants and the degradation of the native soil microbial community. This latter effect might contribute to the sustained decline in aggregate stability following anthropogenic disturbance. Further exploration is advocated to understand the generality of these potential mechanisms.

  6. Native or Non-Native-Speaking Teaching for L2 Pronunciation Teaching?--An Investigation on Their Teaching Effect and Students' Preferences

    Science.gov (United States)

    Li, Ying; Zhang, Gouzhi

    2016-01-01

    This study investigated L2 leaners' preferences between native-speaking teachers (NST) and non-native-speaking teachers (NNST) as their English pronunciation teacher, and examined the participants' accentedness and comprehensibility in L2-English pronunciation after being taught by a NST and a NNST. The participants were 30 undergraduates who were…

  7. Repetition and Turn-Allocation in the Non-Native Acquisition of Discourse. Papers and Reports on Child Language Development, No. 12.

    Science.gov (United States)

    Keller-Cohen, Deborah; Gracey, Cheryl

    A study of non-native children's acquisition of communicative competence examined the child's construction of rules of conversation in the second language. The linguistic devices that children use to link up their utterances with those of another speaker, i.e., cohesion-creating devices that create textual unity, were focused upon. Repetition, one…

  8. Morphological facilitation for regular and irregular verb formations in native and non-native speakers: Little evidence for two distinct mechanisms*

    Science.gov (United States)

    FELDMAN, LAURIE BETH; KOSTIĆ, ALEKSANDAR; BASNIGHT-BROWN, DANA M.; ĐURĐEVIĆ, DUŠICA FILIPOVIĆ; PASTIZZO, MATTHEW JOHN

    2010-01-01

    The authors compared performance on two variants of the primed lexical decision task to investigate morphological processing in native and non-native speakers of English. They examined patterns of facilitation on present tense targets. Primes were regular (billed–bill) past tense formations and two types of irregular past tense forms that varied on preservation of target length (fell–fall; taught–teach). When a forward mask preceded the prime (Exp. 1), language and prime type interacted. Native speakers showed reliable regular and irregular length preserved facilitation relative to orthographic controls. Non-native speakers’ latencies after morphological and orthographic primes did not differ reliably except for regulars. Under cross-modal conditions (Exp. 2), language and prime type interacted. Native but not non-native speakers showed inhibition following orthographically similar primes. Collectively, reliable facilitation for regulars and patterns across verb type and task provided little support for a processing dichotomy (decomposition, non-combinatorial association) based on inflectional regularity in either native or non-native speakers of English. PMID:20526436

  9. Exploring Non-Native English-Speaking Teachers' Beliefs about the Monolingual Approach: Differences between Pre-Service and In-Service Korean Teachers of English

    Science.gov (United States)

    Lee, Jang Ho

    2016-01-01

    The non-native English-speaking teachers' (NNESTs) beliefs about the monolingual approach have not been sufficiently studied in the teaching of English as a foreign language (EFL). In examining the NNESTs' beliefs about that issue, the present study adapts Guy Cook's recent framework, according to which the monolingual approach is based upon four…

  10. Toward a Composite, Personalized, and Institutionalized Teacher Identity for Non-Native English Speakers in U.S. Secondary ESL Programs

    Science.gov (United States)

    Huang, I-Chen; Varghese, Manka M.

    2015-01-01

    Research in English language teaching and teacher identity has increasingly focused on understanding non-native English-speaking teachers. In addition, much of this research has been conducted in adult English as a second language (ESL) settings. Through a multiple-case qualitative study of four teachers in an underexplored research setting--that…

  11. To What Extent Do We Hear Phonemic Contrasts in a Non-Native Regional Variety? Tracking the Dynamics of Perceptual Processing with EEG

    Science.gov (United States)

    Dufour, Sophie; Brunelliere, Angele; Nguyen, Noel

    2013-01-01

    This combined ERP and behavioral experiment explores the dynamics of processing during the discrimination of vowels in a non-native regional variety. Southern listeners were presented with three word forms, two of which are encountered in both Standard and Southern French ([kot] and [kut]), whereas the third one exists in Standard but not Southern…

  12. Learner Agency and Non-Native Speaker Identity in Pedagogical Lingua Franca Conversations: Insights from Intercultural Telecollaboration in Foreign Language Education

    Science.gov (United States)

    Kohn, Kurt; Hoffstaedter, Petra

    2017-01-01

    This article discusses insights gained from a case study on telecollaboration for intercultural communication in foreign language school contexts. Focus was on non-native English and German lingua franca conversations between pairs of students (aged 14-16, B1 level) from schools in France, Germany, the Netherlands and Spain. Telecollaboration…

  13. Growth form and distribution of introduced plants in their native and non-native ranges in Eastern Asia and North America

    Science.gov (United States)

    Robert E. Ricklefs; Qinfeng Guo; Hong Qian

    2008-01-01

    There is a growing interest in understanding the influence of plant traits on their ability to spread in non-native regions. Many studies addressing this issue have been based on relatively small areas or restricted taxonomic groups. Here, we analyse a large data base involving 1567 plant species introduced between Eastern Asia and North America or from elsewhere to...

  14. Investigating Applications of Speech-to-Text Recognition Technology for a Face-to-Face Seminar to Assist Learning of Non-Native English-Speaking Participants

    Science.gov (United States)

    Shadiev, Rustam; Hwang, Wu-Yuin; Huang, Yueh-Min; Liu, Chia-Ju

    2016-01-01

    This study applied speech-to-text recognition (STR) technology to assist non-native English-speaking participants to learn at a seminar given in English. How participants used transcripts generated by the STR technology for learning and their perceptions toward the STR were explored. Three main findings are presented in this study. Most…

  15. Suitability of California bay laurel and other species as hosts for the non-native redbay ambrosia beetle and granulate ambrosia beetle.

    Science.gov (United States)

    Albert (Bud) Mayfield; Martin MacKenzie; Philip G. Cannon; Steve Oak; Scott Horn; Jaesoon Hwang; Paul E. Kendra

    2013-01-01

    The redbay ambrosia beetle Xyleborus glabratus Eichhoff is a non-native vector of the pathogen that causes laurel wilt, a deadly disease of trees in the family Lauraceae in the southeastern U.S.A.Concern exists that X. glabratus and its fungal symbiont could be transported to the western U....

  16. Suitability of California bay laurel and other species as potential hosts for the non-native redbay ambrosia beetle and granulate ambrosia beetle

    Science.gov (United States)

    The redbay ambrosia beetle (Xyleborus glabratus Eichhoff) is a non-native invasive forest pest and vector of the pathogen that causes laurel wilt, a deadly disease of trees in the family Lauraceae in the southeastern United States (U.S.). Concern exists that X. glabratus and its fungal symbiont cou...

  17. Integrated Spatial Models of Non Native Plant Invasion, Fire Risk, and Wildlife Habitat to Support Conservation of Military and Adjacent Lands in the Arid Southwest

    Science.gov (United States)

    2015-12-01

    2002). These species are largely characterized by early winter germination, high viable seed loads, and multiple dispersal mechanisms; in combination...approach to mapping improved our B. tournefortii models, likely because spatial heterogeneity in precipitation drove phenological variability across...via dispersal from wind, vehicles, and water. Table 1: Attributes of non-native invasive plant species targeted by this study. Genus Type

  18. The effect of task complexity on functional adequacy, fluency and lexical diversity in speaking performances of native and non-native speakers

    NARCIS (Netherlands)

    de Jong, N.H.; Steinel, M.P.; Florijn, A.; Schoonen, R.; Hulstijn, J.H.; Housen, A.; Kuiken, F.; Vedder, I.

    2012-01-01

    This study investigated how task complexity affected native and non-native speakers’ speaking performance in terms of a measure of communicative success (functional adequacy), three types of fluency (breakdown fluency, speed fluency, and repair fluency), and lexical diversity. Participants (208 non-

  19. Making the Transition from Non-Native Speaker to Near-Native Speaker Teachers of English: Facing Globalization Challenges in Teaching English

    Science.gov (United States)

    Bin Mohamed Ali, Haja Mohideen

    2009-01-01

    Many job advertisements seeking teachers of English to work in Japan, China, South Korea and Thailand, for instance, specify that they are looking for native speaking teachers from USA, UK, Australia and New Zealand. They do not seem to be interested even in trained non-native speaking teachers from their own countries. This situation also exists…

  20. Investigating Native and Non-Native English-Speaking Teacher Raters' Judgements of Oral Proficiency in the College English Test-Spoken English Test (CET-SET)

    Science.gov (United States)

    Zhang, Ying; Elder, Catherine

    2014-01-01

    This study investigates the impact of raters' language background on their judgements of the speaking performance in the College English Test-Spoken English Test (CET-SET) of China, by comparing the rating patterns of non-native English-speaking (NNES) teacher raters, who are currently employed to assess performance on the CET-SET, with those of…

  1. Short-Term Response of Native Flora to the Removal of Non-Native Shrubs in Mixed-Hardwood Forests of Indiana, USA

    Directory of Open Access Journals (Sweden)

    Joshua M. Shields

    2015-05-01

    Full Text Available While negative impacts of invasive species on native communities are well documented, less is known about how these communities respond to the removal of established populations of invasive species. With regard to invasive shrubs, studies examining native community response to removal at scales greater than experimental plots are lacking. We examined short-term effects of removing Lonicera maackii (Amur honeysuckle and other non-native shrubs on native plant taxa in six mixed-hardwood forests. Each study site contained two 0.64 ha sample areas—an area where all non-native shrubs were removed and a reference area where no treatment was implemented. We sampled vegetation in the spring and summer before and after non-native shrubs were removed. Cover and diversity of native species, and densities of native woody seedlings, increased after shrub removal. However, we also observed significant increases in L. maackii seedling densities and Alliaria petiolata (garlic mustard cover in removal areas. Changes in reference areas were less pronounced and mostly non-significant. Our results suggest that removing non-native shrubs allows short-term recovery of native communities across a range of invasion intensities. However, successful restoration will likely depend on renewed competition with invasive species that re-colonize treatment areas, the influence of herbivores, and subsequent control efforts.

  2. Effects of the Differences between Native and Non-Native English-Speaking Teachers on Students' Attitudes and Motivation toward Learning English

    Science.gov (United States)

    Pae, Tae-Il

    2017-01-01

    This study presents findings on three research agendas: (1) the difference between native English-speaking teachers (NESTs) and non-native English-speaking teachers (NNESTs) in students' attitudes toward and motivation for learning English, (2) the moderating effect of the type of class (i.e., English Conversation vs. Practical English) on the…

  3. Research and Trends in the Studies of Native & Non-Native Speaker Teachers of Languages: A Review on Selected Researches and Theses

    Science.gov (United States)

    SuriatiJusoh, Fathen; Alias, Norlidah; Siraj, Saedah; De Witt, Dorothy; Hussin, Zaharah; Darusalam, Ghazali

    2013-01-01

    Recruiting and employing native speaker teachers of English Language (NST) in non-native speakers' context are widely practised in countries which learn and use the target language taught by the native speaker teachers (NST) as either as a second or a foreign language. This paper reviews selected journals and thesis on the issues of Native and…

  4. Attitudes of Palestinian Undergraduate Students towards Native and Non-Native English Language Teachers and Their Relation to Students' Listening Ability

    Science.gov (United States)

    Nafi, Jamal Subhi Ismail; Qabaja, Ziad Mohammed Mahmoud; Al-Kar, Hibah Jabir Ibrahim

    2016-01-01

    The purpose of this study is to investigate the attitudes of Palestinian undergraduate students towards native and non-native English language teachers and their relation to students' listening ability. To achieve this purpose and to answer the research questions and test the hypotheses, the researchers adopted both the descriptive and inferential…

  5. UV Screening in Native and Non-native Plant Species in the Tropical Alpine: Implications for Climate Change-Driven Migration of Species to Higher Elevations

    Directory of Open Access Journals (Sweden)

    Paul W. Barnes

    2017-08-01

    Full Text Available Ongoing changes in Earth’s climate are shifting the elevation ranges of many plant species with non-native species often experiencing greater expansion into higher elevations than native species. These climate change-induced shifts in distributions inevitably expose plants to novel biotic and abiotic environments, including altered solar ultraviolet (UV-B (280–315 nm radiation regimes. Do the greater migration potentials of non-native species into higher elevations imply that they have more effective UV-protective mechanisms than native species? In this study, we surveyed leaf epidermal UV-A transmittance (TUV A in a diversity of plant species representing different growth forms to test whether native and non-native species growing above 2800 m elevation on Mauna Kea, Hawaii differed in their UV screening capabilities. We further compared the degree to which TUV A varied along an elevation gradient in the native shrub Vaccinium reticulatum and the introduced forb Verbascum thapsus to evaluate whether these species differed in their abilities to adjust their levels of UV screening in response to elevation changes in UV-B. For plants growing in the Mauna Kea alpine/upper subalpine, we found that adaxial TUV A, measured with a UVA-PAM fluorometer, varied significantly among species but did not differ between native (mean = 6.0%; n = 8 and non-native (mean = 5.8%; n = 11 species. When data were pooled across native and non-native taxa, we also found no significant effect of growth form on TUV A, though woody plants (shrubs and trees were represented solely by native species whereas herbaceous growth forms (grasses and forbs were dominated by non-native species. Along an elevation gradient spanning 2600–3800 m, TUV A was variable (mean range = 6.0–11.2% and strongly correlated with elevation and relative biologically effective UV-B in the exotic V. thapsus; however, TUV A was consistently low (3% and did not vary with elevation in the native

  6. Atomistic structural ensemble refinement reveals non-native structure stabilizes a sub-millisecond folding intermediate of CheY

    Science.gov (United States)

    Shi, Jade; Nobrega, R. Paul; Schwantes, Christian; Kathuria, Sagar V.; Bilsel, Osman; Matthews, C. Robert; Lane, T. J.; Pande, Vijay S.

    2017-03-01

    The dynamics of globular proteins can be described in terms of transitions between a folded native state and less-populated intermediates, or excited states, which can play critical roles in both protein folding and function. Excited states are by definition transient species, and therefore are difficult to characterize using current experimental techniques. Here, we report an atomistic model of the excited state ensemble of a stabilized mutant of an extensively studied flavodoxin fold protein CheY. We employed a hybrid simulation and experimental approach in which an aggregate 42 milliseconds of all-atom molecular dynamics were used as an informative prior for the structure of the excited state ensemble. This prior was then refined against small-angle X-ray scattering (SAXS) data employing an established method (EROS). The most striking feature of the resulting excited state ensemble was an unstructured N-terminus stabilized by non-native contacts in a conformation that is topologically simpler than the native state. Using these results, we then predict incisive single molecule FRET experiments as a means of model validation. This study demonstrates the paradigm of uniting simulation and experiment in a statistical model to study the structure of protein excited states and rationally design validating experiments.

  7. Non-native English language speakers benefit most from the use of lecture capture in medical school.

    Science.gov (United States)

    Shaw, Graham P; Molnar, David

    2011-01-01

    Medical education in the United States and Canada continues to evolve. However, many of the changes in pedagogy are being made without appropriate evaluation. Here, we attempt to evaluate the effectiveness of lecture capture technology as a learning tool in Podiatric medical education. In this pilot project, student performance in an inaugural lecture capture-supported biochemistry course was compared to that in the previous academic year. To examine the impact of online lecture podcasts on student performance a within-subjects design was implemented, a two way ANCOVA with repeated measures. The use of lecture capture-supported pedagogy resulted in significantly higher student test scores, than achieved historically using traditional pedagogy. The overall course performance using this lecture capture-supported pedagogy was almost 6% higher than in the previous year. Non-native English language speakers benefitted more significantly from the lecture capture-supported pedagogy than native English language speakers, since their performance improved by 10.0 points. Given that underrepresented minority (URM) students, whose native language is not English, makes up a growing proportion of medical school matriculates, these observations support the use of lecture capture technology in other courses. Furthermore, this technology may also be used as part of an academic enrichment plan to improve performance on the American Podiatric Medical Licensing Examination, reduce the attrition of URM students and potentially address the predicted minority physician shortage in 2020.

  8. Atomistic structural ensemble refinement reveals non-native structure stabilizes a sub-millisecond folding intermediate of CheY

    Science.gov (United States)

    Shi, Jade; Nobrega, R. Paul; Schwantes, Christian; Kathuria, Sagar V.; Bilsel, Osman; Matthews, C. Robert; Lane, T. J.; Pande, Vijay S.

    2017-01-01

    The dynamics of globular proteins can be described in terms of transitions between a folded native state and less-populated intermediates, or excited states, which can play critical roles in both protein folding and function. Excited states are by definition transient species, and therefore are difficult to characterize using current experimental techniques. Here, we report an atomistic model of the excited state ensemble of a stabilized mutant of an extensively studied flavodoxin fold protein CheY. We employed a hybrid simulation and experimental approach in which an aggregate 42 milliseconds of all-atom molecular dynamics were used as an informative prior for the structure of the excited state ensemble. This prior was then refined against small-angle X-ray scattering (SAXS) data employing an established method (EROS). The most striking feature of the resulting excited state ensemble was an unstructured N-terminus stabilized by non-native contacts in a conformation that is topologically simpler than the native state. Using these results, we then predict incisive single molecule FRET experiments as a means of model validation. This study demonstrates the paradigm of uniting simulation and experiment in a statistical model to study the structure of protein excited states and rationally design validating experiments. PMID:28272524

  9. Metadiscourse markers in biological research articles and journal impact factor: Non-native writers vs. native writers.

    Science.gov (United States)

    Gholami, Javad; Ilghami, Roghayeh

    2016-07-08

    Metadiscourse markers (MDMs) are lexical resources that writers employ to organize their discourse and state their stance towards the content or the reader. This study investigated the frequency with which interactive and interactional MDMs were employed in biological research articles (RAs). It also explored the possible relationship between the frequency of these markers and Impact Factor (IF) of journals as an index of quality. Moreover, it aimed at finding out the difference(s) between two groups of authors (Iranian and American) in their use of these markers. Forty biological RAs published in years 2008-2011 written by Iranian non-native authors and published in four ISI journals with different IFs and 40 articles with the same characteristics published by American native authors were selected and examined for the use of the markers. The results showed that there was a strong positive correlation between the frequency of MDMs and IF of the journals. Regarding the frequency of MDMs, it was observed that Iranian authors employed interactive and interactional markers slightly more than their American counterparts. These results may provisionally confirm the considerable role of MDMs in enhancing the coherence and organization of articles for possible publication in high-impact journals. © 2016 by The International Union of Biochemistry and Molecular Biology, 44(4):349-360, 2016.

  10. Elucidating Native and Non-Native Plant-Fog Interactions Across Microclimatic Zones in San Cristobal Island, Galapagos

    Science.gov (United States)

    Schmitt, S.; Riveros-Iregui, D. A.; Hu, J.

    2015-12-01

    Changes in land use, such as the clear cutting of forests and the abandonment of land once used for agriculture, pose an incredible threat to the fragile ecosystems in the tropics. One such consequence of land use change in the tropics is the propagation of invasive plant species. The Galapagos Islands, an ecosystem subject to significant anthropogenic pressure by both increasing tourism and a growing native population, are especially threatened by invasive plant species. More than 800 plant species have been introduced in Galapagos, comprising over 60% of the total flora. San Cristobal Island in particular has been impacted by the introduction of non-native species; the combined pressures of invasive species and land use change have fundamentally altered 70% of the landscape of the island. We performed stable isotope analysis of fog water, surface water and plant xylem water to examine water use by both native and invasive plant species across different microclimatic zones. We conducted these measurements starting at the end of the rainy season and through the middle of the dry season. Our results represent an initial effort to characterize the effects of a changing vegetative cover on the water cycling of tropical islands and provide insight into the interactions between plants, surface water and groundwater at various spatial and temporal scales.

  11. How Will Climate Warming Affect Non-Native Pumpkinseed Lepomis gibbosus Populations in the U.K.?

    Science.gov (United States)

    Zięba, Grzegorz; Fox, Michael G; Copp, Gordon H

    2015-01-01

    Of the non-native fishes introduced to the U.K., the pumpkinseed is one of six species predicted to benefit from the forecasted climate warming conditions. To demonstrate the potential response of adults and their progeny to a water temperature increase, investigations of parental pumpkinseed acclimatization, reproduction and YOY over-wintering were carried out in outdoor experimental ponds under ambient and elevated water temperature regimes. No temperature effects were observed on either adult survivorship and growth, and none of the assessed reproductive activity variables (total spawning time, spawning season length, number of spawning bouts) appeared to be responsible for the large differences observed in progeny number and biomass. However, it was demonstrated in a previous study [Zięba G. et al., 2010] that adults in the heated ponds began spawning earlier than those of the ambient ponds. Ambient ponds produced 2.8× more progeny than the heated ponds, but these progeny were significantly smaller, probably due to their late hatching date, and subsequently suffered very high mortality over the first winter. Pumpkinseed in the U.K. will clearly benefit from climate warming through earlier seasonal reproduction, resulting in larger progeny going into winter, and as a result, higher over-winter survivorship would be expected relative to that which occurs under the present climatic regime.

  12. How Will Climate Warming Affect Non-Native Pumpkinseed Lepomis gibbosus Populations in the U.K.?

    Directory of Open Access Journals (Sweden)

    Grzegorz Zięba

    Full Text Available Of the non-native fishes introduced to the U.K., the pumpkinseed is one of six species predicted to benefit from the forecasted climate warming conditions. To demonstrate the potential response of adults and their progeny to a water temperature increase, investigations of parental pumpkinseed acclimatization, reproduction and YOY over-wintering were carried out in outdoor experimental ponds under ambient and elevated water temperature regimes. No temperature effects were observed on either adult survivorship and growth, and none of the assessed reproductive activity variables (total spawning time, spawning season length, number of spawning bouts appeared to be responsible for the large differences observed in progeny number and biomass. However, it was demonstrated in a previous study [Zięba G. et al., 2010] that adults in the heated ponds began spawning earlier than those of the ambient ponds. Ambient ponds produced 2.8× more progeny than the heated ponds, but these progeny were significantly smaller, probably due to their late hatching date, and subsequently suffered very high mortality over the first winter. Pumpkinseed in the U.K. will clearly benefit from climate warming through earlier seasonal reproduction, resulting in larger progeny going into winter, and as a result, higher over-winter survivorship would be expected relative to that which occurs under the present climatic regime.

  13. A note on the acoustic-phonetic characteristics of non-native English vowels produced in noise

    Science.gov (United States)

    Li, Chi-Nin; Munro, Murray J.

    2003-10-01

    The Lombard reflex occurs when people unconsciously raise their vocal levels in the presence of loud background noise. Previous work has established that utterances produced in noisy environments exhibit increases in vowel duration and fundamental frequency (F0), and a shift in formant center frequencies for F1 and F2. Most studies of the Lombard reflex have been conducted with native speakers; research with second-language speakers is much less common. The present study examined the effects of the Lombard reflex on foreign-accented English vowel productions. Seven female Cantonese speakers and a comparison group of English speakers were recorded producing three vowels (/i u a/) in /bVt/ context in quiet and in 70 dB of masking noise. Vowel durations, F0, and the first two formants for each of the three vowels were measured. Analyses revealed that vowel durations and F0 were greater in the vowels produced in noise than those produced in quiet in most cases. First formants, but not F2, were consistently higher in Lombard speech than in normal speech. The findings suggest that non-native English speakers exhibit acoustic-phonetic patterns similar to those of native speakers when producing English vowels in noisy conditions.

  14. Invaders in hot water: a simple decontamination method to prevent the accidental spread of aquatic invasive non-native species.

    Science.gov (United States)

    Anderson, Lucy G; Dunn, Alison M; Rosewarne, Paula J; Stebbing, Paul D

    Watersports equipment can act as a vector for the introduction and spread of invasive non native species (INNS) in freshwater environments. To support advice given to recreational water users under the UK Government's Check Clean Dry biosecurity campaign and ensure its effectiveness at killing a range of aquatic INNS, we conducted a survival experiment on seven INNS which pose a high risk to UK freshwaters. The efficacy of exposure to hot water (45 °C, 15 min) was tested as a method by which waters users could 'clean' their equipment and was compared to drying and a control group (no treatment). Hot water had caused 99 % mortality across all species 1 h after treatment and was more effective than drying at all time points (1 h: χ(2) = 117.24, p water or drying, 6/7 of these species survived for 16 days, highlighting the importance of good biosecurity practice to reduce the risk of accidental spread. In an additional experiment the minimum lethal temperature and exposure time in hot water to cause 100 % mortality in American signal crayfish (Pacifastacus leniusculus), was determined to be 5 min at 40 °C. Hot water provides a simple, rapid and effective method to clean equipment. We recommend that it is advocated in future biosecurity awareness campaigns.

  15. Pragmatic assessment of request speech act of Iranian EFL learners by non-native English speaking teachers

    Directory of Open Access Journals (Sweden)

    Minoo Alemi

    2016-07-01

    Full Text Available The analysis of raters' comments on pragmatic assessment of L2 learners is among new and understudied concepts in second language studies. To shed light on this issue, the present investigation targeted important variables such as raters’ criteria and rating patterns by analyzing the interlanguage pragmatic assessment process of the Iranian non-native English speaking raters (NNESRs regarding the request speech act, while considering important factors such as raters’ gender and background teaching experiences. For this purpose, 62 raters’ rating scores and comments on Iranian EFL learners’ requests based on six situations of specified video prompts were analyzed. The results of the content analysis of raters’ comments revealed nine criteria, including pragmalinguistic and socio-pragmatic components of language, which have been noted by raters differently through six request situations. Among the considered criteria, politeness, conversers’ relationship, style and register, and explanation were of great importance to NNESRs. Furthermore, t-test and chi-square analysis of raters’ assigned rating scores and mentioned criteria across different situations verified the insignificance of factors such as raters’ gender and teaching experiences on the process of EFL learners’ pragmatic assessment. In addition, the results of the study suggest the necessity of teaching L2 pragmatics in language classes and in teacher training courses.

  16. The effect of language immersion education on the preattentive perception of native and non-native vowel contrasts.

    Science.gov (United States)

    Peltola, Maija S; Tuomainen, Outi; Koskinen, Mira; Aaltonen, Olli

    2007-01-01

    Proficiency in a second language (L2) may depend upon the age of exposure and the continued use of the mother tongue (L1) during L2 acquisition. The effect of early L2 exposure on the preattentive perception of native and non-native vowel contrasts was studied by measuring the mismatch negativity (MMN) response from 14-year-old children. The test group consisted of six Finnish children who had participated in English immersion education. The control group consisted of eight monolingual Finns. The subjects were presented with Finnish and English synthetic vowel contrasts. The aim was to see whether early exposure had resulted in the development of a new language-specific memory trace for the contrast phonemically irrelevant in L1. The results indicated that only the contrast with the largest acoustic distance elicited an MMN response in the Bilingual group, while the Monolingual group showed a response also to the native contrast. This may suggest that native-like memory traces for prototypical vowels were not formed in early language immersion.

  17. Environmental Degradation in a Eutrophic Shallow Lake is not Simply Due to Abundance of Non-native Cyprinus carpio

    Science.gov (United States)

    Ramírez-Herrejón, Juan P.; Mercado-Silva, Norman; Balart, Eduardo F.; Moncayo-Estrada, Rodrigo; Mar-Silva, Valentín; Caraveo-Patiño, Javier

    2015-09-01

    Non-native species are often major drivers of the deterioration of natural ecosystems. The common carp Cyprinus carpio are known to cause major changes in lentic systems, but may not be solely responsible for large scale changes in these ecosystems. We used data from extensive collection efforts to gain insight into the importance of carp as drivers of ecosystem change in Lake Patzcuaro, Mexico. We compared the structure (fish density, biomass, diversity, and evenness) of fish assemblages from six Lake Patzcuaro sites with different habitat characteristics. Intersite comparisons were carried out for both wet and dry seasons. We explored the relationships between non-carp species and carp; and studied multivariate interactions between fish abundance and habitat characteristics. From a biomass perspective, carp was dominant in only four of six sites. In terms of density, carp was not a dominant species in all sites. Further, carp density and biomass were not negatively related to native species density and biomass, even when carp density and biomass were positively correlated to water turbidity levels. Carp dominated fish assemblages in the shallowest sites with the highest water turbidity, plant detritus at the bottom, and floating macrophytes covering the lake surface. These results suggest that the effect of carp on fish assemblages may be highly dependent on habitat characteristics in Lake Patzcuaro. Watershed degradation, pollution, water level loss, and other sources of anthropogenic influence may be more important drivers of Lake Patzcuaro degradation than the abundance of carp.

  18. How Will Climate Warming Affect Non-Native Pumpkinseed Lepomis gibbosus Populations in the U.K.?

    Science.gov (United States)

    Zięba, Grzegorz; Fox, Michael G.; Copp, Gordon H.

    2015-01-01

    Of the non-native fishes introduced to the U.K., the pumpkinseed is one of six species predicted to benefit from the forecasted climate warming conditions. To demonstrate the potential response of adults and their progeny to a water temperature increase, investigations of parental pumpkinseed acclimatization, reproduction and YOY over-wintering were carried out in outdoor experimental ponds under ambient and elevated water temperature regimes. No temperature effects were observed on either adult survivorship and growth, and none of the assessed reproductive activity variables (total spawning time, spawning season length, number of spawning bouts) appeared to be responsible for the large differences observed in progeny number and biomass. However, it was demonstrated in a previous study [Zięba G. et al., 2010] that adults in the heated ponds began spawning earlier than those of the ambient ponds. Ambient ponds produced 2.8× more progeny than the heated ponds, but these progeny were significantly smaller, probably due to their late hatching date, and subsequently suffered very high mortality over the first winter. Pumpkinseed in the U.K. will clearly benefit from climate warming through earlier seasonal reproduction, resulting in larger progeny going into winter, and as a result, higher over-winter survivorship would be expected relative to that which occurs under the present climatic regime. PMID:26302021

  19. [Psychosocial risk of fossilization by occupationally-used non-native Englishin information and communication technologists of Argentina].

    Science.gov (United States)

    Serra, Silvana Valeria; Buonanotte, Federico; Frankel, Lilian; Brizuela, Monica; Serra, Mariel; Soria, Elio Andres

    2016-01-01

    Companies use non-native language (L2) as a service tool, and they may incur in occupational psychosocial risks. Interlanguage can be chronic under poor communicative situations, leading to fossilization. It could be an adverse effect because of its impact in productivity and occupational health. Thus, our aim was to establish factors of this psychosocial risk. 348 information and communication technologists (ICT) were analyzed. They were native Spanish speakers with normal hearing, and used English as a work tool. Age, gender, L2 stages and errors were recorded in relation to fossilization risk. Statistical methods were applied for categorical data (p<0.05). After gender and age adjustments, a significant inverse association was found between L2 stages and fossilization risk (p<0.0001), with higher risk being in the acquisition stage. Also, L2 errors showed a significant direct relation with fossilization risk (p=0.0005). Summing up, ICT in acquisition L2 had upper psychosocial risk to fossilization with mechanistic execution of it, under poorer communicative formats. This results have high sanitary impact given they involved a massively demanded professionals.

  20. Fungal endophytes from seeds of invasive, non-native Phragmites australis and their potential role in germination and seedling growth

    Science.gov (United States)

    Shearin, Zackery R. C.; Filipek, Matthew; Desai, Rushvi; Bickford, Wesley A.; Kowalski, Kurt P.; Clay, Keith

    2017-01-01

    Background and aimsWe characterized fungal endophytes of seeds of invasive, non-native Phragmites from three sites in the Great Lakes region to determine if fungal symbiosis could contribute to invasiveness through their effects on seed germination and seedling growth.MethodsField-collected seeds were surface sterilized and plated on agar to culture endophytes for ITS sequencing. Prevalence of specific endophytes from germinated and non-germinated seeds, and from seedlings, was compared.ResultsOne-third of 740 seeds yielded endophyte isolates. Fifteen taxa were identified with Alternaria sp. representing 54% of all isolates followed by Phoma sp. (21%) and Penicillium corylophilum (12%). Overall germination of seeds producing an isolate (36%) was significantly higher than seeds not producing an isolate (20%). Penicillium in particular was strongly associated with increased germination of seeds from one site. Sixty-three isolates and 11 taxa were also obtained from 30 seedlings where Phoma, Penicillium and Alternaria respectively were most prevalent. There was a significant effect of isolating an endophyte from the seed on seedling growth.ConclusionsThese results suggest that many endophyte taxa are transmitted in seeds and can increase seed germination and seedling growth of invasive Phragmites. The role of fungal endophytes in host establishment, growth and invasiveness in nature requires further research.

  1. Non-native seagrass

    NARCIS (Netherlands)

    van Tussenbroek, B.I.; van Katwijk, M.M.; Bouma, T.J.; van der Heide, T.; Govers, L.L.; Leuven, R.S.E.W.

    2016-01-01

    Seagrasses comprise 78 species and are rarely invasive. But the seagrass Halophila stipulacea, firstly recorded in the Caribbean in the year 2002, has spread quickly throughout the region. Previous works have described this species as invasive in the Caribbean, forming dense mats that exclude native

  2. [The butterflies (Lepidoptera, Diurna) of the boreal forests in southeastern Russia. II. Light coniferous forests].

    Science.gov (United States)

    Martynenko, A B

    2009-01-01

    Species groupings formed in dark coniferous forests of southeastern Russia are analyzed by the example of butterflies. The species and chorological composition of these groupings are discussed. Classification analysis of species checklists for twelve local faunas is given. It is indicated that the applicability of a single faunistic category to all the dark coniferous forests of the studied region is doubtful.

  3. Affinity and activity of non-native quinones at the QB site of bacterial photosynthetic reaction centers

    Science.gov (United States)

    Zhang, Xinyu; Gunner, M. R.

    2014-01-01

    Purple, photosynthetic reaction centers (RCs) from Rb. sphaeroides bacteria use UQ10 as primary (QA) and secondary (QB) electron acceptors. Many quinones reconstitute QA function, while few will act as QB. Nine quinones were tested for their ability to bind and reconstitute QA and QB function. Only ubiquinone (UQ) reconstitutes both QA and QB function in the same protein. The affinities of the non-native quinones for the QB site were determined by a competitive inhibition assay. The affinities of benzoquinones (BQ), napthoquinone (NQ) and 2-methyl-NQ for the QB site are 7±3 times weaker than for the QA site. However, di-ortho substituted NQs and anthraquinone bind tightly to the QA site (Kd ≤200 nM) and ≥1000 times more weakly to the QB site, perhaps setting a limit on the size of the site. With a low potential electron donor (2-methyl, 3-dimethylamino-1,4-Napthoquinone (Me-diMeAm-NQ)) at QA, QB reduction is 260 meV more favorable than with UQ as QA. Electron transfer from Me-diMeAm-NQ at the QA site to NQ at the QB site can be detected. In the QB site the NQ semiquinone is estimated to be ≈ 60–100 meV higher in energy than the UQ semiquinone, while in the QA site the semiquinone energy level is similar or lower with NQ than with UQ. Thus, the NQ semiquinone is more stable in the QA than QB site. In contrast, the native UQ semiquinone is ≈ 60 meV lower in energy in the QB than the QA site, stabilizing forward electron transfer from QA to QB. PMID:23715773

  4. Polysemous Verbs and Modality in Native and Non-Native Argumentative Writing: A Corpus-Based Study

    Directory of Open Access Journals (Sweden)

    Danica Salazar

    2009-12-01

    Full Text Available The present study is a corpus-based analysis of a selection of polysemous lexical verbs used to express modality in student argumentative writing. Twenty-three lexical verbs were searched for in three 100,000-word corpora of argumentative essays written in English by American, Filipino and Spanish university students. Concordance lines were examined to determine their use in the three corpora. After presenting the overall results for all verbs studied, more in-depth linguistic analysis was performed on the polysemous verb feel. These analyses revealed that the non-native writers, unlike their native counterparts, had a limited grasp of the full range of meanings of lexical verbs such as feel. It also showed that all student writers under study employed only a restricted range of lexical verbs to convey modal meanings in their writing.En este artículo presentamos un análisis de una selección de verbos polisémicos, utilizados para expresar modalidad, en tres corpus de textos argumentativos escritos en inglés por estudiantes universitarios americanos, filipinos y españoles. Después de exponer los resultados generales, se presenta un análisis más exhaustivo del verbo polisémico feel, que revela que los estudiantes no nativos, a diferencia de los nativos, tienen un conocimiento limitado de su diversidad de sentidos. También muestra que todos los estudiantes analizados usaron un repertorio restringido de verbos léxicos que expresan modalidad.

  5. The effect of visuals on non-native English students' learning of the basic principles and laws of motion

    Science.gov (United States)

    Yang, Quan

    2001-10-01

    This study, involving 154 undergraduate college students in China, was conducted to determine whether the surface structure of visual graphics affect content learning when the learner was a non-native English speaker and learning took place in a non-English speaking environment. Instruction with concrete animated graphics resulted in significantly higher achievement, when compared to instruction with concrete static, abstract static, abstract animated graphics or text only without any graphical illustrations. It was also found, unexpectedly, the text-only instruction resulted in the second best achievement, significantly higher than instruction with concrete static, abstract static, and abstract animated graphics. In addition, there was a significant interaction with treatment and test item, which indicated that treatment effects on graphic-specific items differed from those on definitional items. Additional findings indicated that relation to graphics directly or indirectly from the text that students studied had little impact on their performance in the posttests. Further, 51% of the participants indicated that they relied on some graphical images to answer the test questions and 19% relied heavily on graphics when completing the tests. In conclusion, concrete graphics when combined with animation played a significant role in enhancing ESL student performance and enabled the students to achieve the best learning outcomes as compared to abstract animated, concrete static, and abstract static graphics. This result suggested a significant innovation in the design and development of ESL curriculum in computer-based instruction, which would enable ESL students to perform better and achieve the expected outcomes in content area learning.

  6. Non-native western tubenose gobies Proterorhinus semilunaris show distinct site, sex and age-related differences in diet

    Directory of Open Access Journals (Sweden)

    Všetičková L.

    2014-01-01

    Full Text Available The tubenose goby, Proterorhinus semilunaris, has expanded its range throughout Europe. Comprehensive studies to identify its impact on native riverine ecosystems, however, are relatively scarce. Here, we evaluate dietary preferences of P. semilunaris on a non-native river to reveal any such impacts. Fish were sampled monthly over 2011–2012 from three sites along the River Dyje (Czech Republic; Danube basin with differing population levels and food availability. Both the amount of food consumed and dietary composition varied seasonally, with site having a strong effect. Food consumed differed between males and females, but not dietary composition; while diet differed between age classes, but not food consumed. In general, Trichoptera, Chironomidae and zooplankton dominated the diet at all sites, with Trichoptera taken more often earlier in the year and zooplankton later. Mussels were always avoided, despite high abundance, while less preferred prey were occasionally taken in high numbers in response to increased availability or energy demand (e.g. spawning. Fish eggs and fry (all P. semilunaris were only taken in high numbers at one site, being related to high population level and fry drift from a reservoir. Male feeding declined over the breeding season, presumably due to nest guarding, while female feeding declined over winter, possibly resulting in high mortality. Proterorhinus semilunaris is a feeding opportunist, which may facilitate colonisation in habitats with poor prey availability. No predation pressure on native species was observed through consumption of eggs or fry, though small/young indigenous fish may be affected through diet competition.

  7. FEEDING INTERACTION OF THE NON-NATIVE AFRICAN CATFISH (Clarias gariepinus BURCHELL, 1822 IN ITANHÉM RIVER ESTUARY, BAHIA, BRAZIL

    Directory of Open Access Journals (Sweden)

    Leandro Bonesi Rabelo

    2014-09-01

    Full Text Available A total of 214 stomachs of Clarias gariepinus, Centropomus undecimalis and C. parallelus from the Itanhém and Caravelas Rivers, northeastern Brazil, were analyzed to investigate the impact of the non-native species Clarias gariepinus on the Itanhém River food web as compared to that of the adjacent Caravelas River, where this species has not been registered. In Itanhém River, shrimp was the most important food for C. gariepinus, and Teleostei for C. parallelus. In the Caravelas River, Brachyura was the main food item for C. parallelus, and Teleostei for C. undecimalis. There was no food overlap between the species within or between rivers. There is no evidence, in the results of this study, of changes in the diet of the Centropomus parallelus due to the presence of the non-native species.

  8. Persistence and extirpation in invaded landscapes: patch characteristics and connectivity determine effects of non-native predatory fish on native salamanders

    Science.gov (United States)

    Pilliod, David S.; Arkle, Robert S.; Maxell, Bryce A.

    2012-01-01

    Studies have demonstrated negative effects of non-native, predatory fishes on native amphibians, yet it is still unclear why some amphibian populations persist, while others are extirpated, following fish invasion. We examined this question by developing habitat-based occupancy models for the long-toed salamander (Ambystoma macrodactylum) and nonnative fish using survey data from 1,749 water bodies across 470 catchments in the Northern Rocky Mountains, USA. We first modeled the habitat associations of salamanders at 468 fishless water bodies in 154 catchments where non-native fish were historically, and are currently, absent from the entire catchment. Wethen applied this habitat model to the complete data set to predict the probability of salamander occupancy in each water body, removing any effect of fish presence. Finally, we compared field-observed occurrences of salamanders and fish to modeled probability of salamander occupancy. Suitability models indicated that fish and salamanders had similar habitat preferences, possibly resulting in extirpations of salamander populations from entire catchments where suitable habitats were limiting. Salamanders coexisted with non-native fish in some catchments by using marginal quality, isolated (no inlet or outlet) habitats that remained fishless. They rarely coexisted with fish within individual water bodies and only where habitat quality was highest. Connectivity of water bodies via streams resulted in increased probability of fish invasion and consequently reduced probability of salamander occupancy.These results could be used to identify and prioritize catchments and water bodies where control measures would be most effective at restoring amphibian populations. Our approach could be useful as a framework for improved investigations into questions of persistence and extirpation of native species when non-native species have already become established.

  9. Altitudinal occurrence of non-native plant species (neophytes) and their habitat affinity to anthropogenic biotopes in conditions of South-Western Slovakia

    OpenAIRE

    Beniak Michal; Pauková Žaneta; Fehér Alexander

    2015-01-01

    Many ecological studies showed that species density (the number of species per unit area) in nonnative organism groups of the mountain areas decreases with increasing altitude. The aim of the paper is to determine the variability in the incidence of non-native plant species (neophytes) associated with the change in altitude and links of the invading taxons to reference habitat types, as well as their links to three ecologically very similar, however in natural conditions, different areas. In ...

  10. Trade in non-native, CITES-listed, wildlife in Asia, as exemplified by the trade in freshwater turtles and tortoises (Chelonidae) in Thailand

    OpenAIRE

    Nijman, V; Shepherd, C.R.

    2007-01-01

    In 1973 the Convention in International Trade in Endangered Species of Wild Fauna and Flora (CITES) was called to life as to regulate the international wildlife trade, and to prevent species becoming (economically and biologically) extinct. The trade in freshwater turtles and tortoises in Asia is so huge that it threatens the survival of many species. In 2006 and 2007, during three surveys at Chatuchak market in Bangkok, Thailand, we recorded a significant trade in non-native CITES-listed fre...

  11. The roles of climate, phylogenetic relatedness, introduction effort, and reproductive traits in the establishment of non-native reptiles and amphibians.

    Science.gov (United States)

    van Wilgen, Nicola J; Richardson, David M

    2012-04-01

    We developed a method to predict the potential of non-native reptiles and amphibians (herpetofauna) to establish populations. This method may inform efforts to prevent the introduction of invasive non-native species. We used boosted regression trees to determine whether nine variables influence establishment success of introduced herpetofauna in California and Florida. We used an independent data set to assess model performance. Propagule pressure was the variable most strongly associated with establishment success. Species with short juvenile periods and species with phylogenetically more distant relatives in regional biotas were more likely to establish than species that start breeding later and those that have close relatives. Average climate match (the similarity of climate between native and non-native range) and life form were also important. Frogs and lizards were the taxonomic groups most likely to establish, whereas a much lower proportion of snakes and turtles established. We used results from our best model to compile a spreadsheet-based model for easy use and interpretation. Probability scores obtained from the spreadsheet model were strongly correlated with establishment success as were probabilities predicted for independent data by the boosted regression tree model. However, the error rate for predictions made with independent data was much higher than with cross validation using training data. This difference in predictive power does not preclude use of the model to assess the probability of establishment of herpetofauna because (1) the independent data had no information for two variables (meaning the full predictive capacity of the model could not be realized) and (2) the model structure is consistent with the recent literature on the primary determinants of establishment success for herpetofauna. It may still be difficult to predict the establishment probability of poorly studied taxa, but it is clear that non-native species (especially lizards

  12. Has the emergence of English as a Lingua Franca been an entirely beneficial phenomenon for both native and non-native English speakers

    Institute of Scientific and Technical Information of China (English)

    HU; RUOXI

    2015-01-01

    <正>Recently,the emergence of English as a lingua franca generates a controversial issue which has been fiercely discussed whether it is a wholly beneficial phenomenon for both native and non-native English speakers.Based on the Cambridge Encyclopedia of Language,English was widely transmitted all over the world due to the British colonization in the early19th century.With advanced industry and frequent multilateral trade,Britain further impelled the spread of English.Besides,

  13. Mycorrhizal detection of native and non-native truffles in a historic arboretum and the discovery of a new North American species, Tuber arnoldianum sp. nov.

    Science.gov (United States)

    Healy, Rosanne A; Zurier, Hannah; Bonito, Gregory; Smith, Matthew E; Pfister, Donald H

    2016-10-01

    During a study comparing the ectomycorrhizal root communities in a native forest with those at the Arnold Arboretum in Massachusetts (USA), the European species Tuber borchii was detected on the roots of a native red oak in the arboretum over two successive years. Since T. borchii is an economically important edible truffle native to Europe, we conducted a search of other roots in the arboretum to determine the extent of colonization. We also wanted to determine whether other non-native Tuber species had been inadvertently introduced into this 140-year-old Arboretum because many trees were imported into the site with intact soil and roots prior to the 1921 USDA ban on these horticultural practices in the USA. While T. borchii was not found on other trees, seven other native and exotic Tuber species were detected. Among the North American Tuber species detected from ectomycorrhizae, we also collected ascomata of a previously unknown species described here as Tuber arnoldianum. This new species was found colonizing both native and non-native tree roots. Other ectomycorrhizal taxa that were detected included basidiomycetes in the genera Amanita, Russula, Tomentella, and ascomycetes belonging to Pachyphlodes, Helvella, Genea, and Trichophaea. We clarify the phylogenetic relationships of each of the Tuber species detected in this study, and we discuss their distribution on both native and non-native host trees.

  14. Re-cycling mercury: the role of stocking non-native fish in high-altitude lakes

    Science.gov (United States)

    Hansson, S. V.; Le Roux, G.; Sonke, J.

    2016-12-01

    Mercury (Hg) is a globally distributed pollutant that can be carried long distances and be deposited remote from its original source. It is also one of the few natural abundant trace metals that serves no biological purpose, i.e. is highly toxic to humans and other biota. Studies have also shown that Hg-deposition increases with increasing altitude, leading to a higher load of contamination to these already sensitive environments. Any additional sources of Hg to high-altitude aquatic systems are therefore of high concern. Today introduced non-indigenous fish can be found in aquatic systems on all contents, with the exception of Antarctica. However, the social and economic benefits gained by these introductions often weighs against the ecological impacts. E.g. studies have shown that introduction of carnivore fish can lead to alternation of the aquatic food web and introduce pathogens causing population declines or even extinction. Few studies however have looked at the introduction of non-native fish to high altitude aquatic systems in the scope of heavy-metal contamination. By using a combined geochemical and isotopic approach, we therefore study the introduction of brown trout as a potential source of Hg-contamination in three high altitude lakes in the French Pyrenees. We combine analysis of δ13C and δ15N, with tot-Hg and Hg-isotopes in samples of biofilm, invertebrates, common minnow and brow trout and compare these with data from trout bred at a local fish farm, providing the fish used when stocking lakes in the nearby region. Our results show that levels of tot-Hg in trout from our sites surpasses literature values by 5 times or more and that MIF and MDF Hg-isotope signatures shows clear relationship with fish size and with δ15N. However, there is a clear difference in the Hg-isotopic signatures of the wild trout compared to the farmed. Whereas δ202Hg and Δ199Hg-signatures of the wild trout aligns with the onsite food chain (biofilm, plankton, common

  15. North American coral snake antivenin for the neutralization of non-native elapid venoms in a murine model.

    Science.gov (United States)

    Richardson, William H; Tanen, David A; Tong, Tri C; Betten, David P; Carstairs, Shaun D; Williams, Saralyn R; Cantrell, Frank L; Clark, Richard F

    2006-02-01

    North American coral snake antivenin (CSAV; Wyeth Antivenin [Micrurus fulvius], equine origin) is approved for the treatment of coral snake envenomations in the United States. The coral snake is the only elapid that is native to North America, but envenomations from non-native elapids are occurring more commonly in this country. This study was designed to evaluate the efficacy of CSAV in the neutralization of two exotic elapid envenomations: Naja naja (Indian cobra) and Dendroaspis polylepsis (black mamba). A randomized, blinded, placebo-controlled murine model of intraperitoneal venom injection was employed. Venom potency was determined in preliminary dosing studies. Study animals then were divided into five groups: 1) N. naja venom + CSAV, 2) N. naja venom + 0.9% normal saline (NS), 3) D. polylepsis venom + CSAV, 4) D. polylepsis venom + NS, and 5) CSAV + NS. The venom dose was chosen to be twice the estimated LD50. The amount of CSAV injected was ten times the amount necessary for neutralization of a 2 x LD50 dose of M. f. fulvius venom in a murine model. Statistical analysis included Fisher's exact and log-rank testing to compare survival rates and times. Preliminary studies estimated the venom LD50 to be 2.58 mg/kg and 0.45 mg/kg, respectively, for the N. naja and D. polylepsis. A significant difference was shown in comparison of survival times between CSAV-venom groups and normal saline-venom groups despite all animals in both treatment and control arms dying. Animals receiving CSAV and N. naja venom survived (mean +/- SD) 24.4 +/- 3.0 minutes, versus 17.8 +/- 1.3 minutes in the control group (p < 0.001), whereas those receiving CSAV and D. polylepsis venom survived 203.8 +/- 37.0 minutes versus 130.0 +/- 42.6 minutes in the control group (p < 0.001). All animals in the CSAV + NS group survived to the conclusion of the study. When premixed with venom, CSAV increased survival time in a murine model of intraperitoneal N. naja and D. polylepsis venom injection

  16. Organic compounds in atmospheric aerosols from a Finnish coniferous forest

    Energy Technology Data Exchange (ETDEWEB)

    Anttila, P.; Rissanen, T.; Shimmo, M.; Kallio, M.; Hyoetylaeinen, T.; Riekkola, M.L. [Laboratory of Analytical Chemistry, Department of Chemistry, University of Helsinki (Finland); Kulmala, M. [Department of Physical Sciences, University of Helsinki (Finland)

    2005-07-01

    Atmospheric aerosol particles were collected with a high-volume sampler in a Finnish coniferous forest during the field campaign Quantification of Aerosol Nucleation in the European Boundary Layer (QUEST) in March-April 2003. Four chromatographic techniques were applied to characterise the organic composition of the samples, and to study variations in the concentrations of identified compounds. Among the nearly 160 organic compounds identified were n-alkanes, nalkanals, n-alkan-2-ones, n- alkanols, n-alkanoic acids, n-alkenoic acids, dicarboxylic acids, polyaromatic hydrocarbons, hopanes, streranes, terpenes and terpenoids. The observed variations in the concentrations of certain compounds were mostly explained by ambient temperature. Comparison of days when atmospheric new particle formation took place with days when the formation did not occur, however, revealed higher concentrations of long-chain n- alkanes (> C{sub 22}) and < C{sub 18} n-alkanoic acids on the particle formation days. (orig.)

  17. The influences of canopy species and topographic variables on understory species diversity and composition in coniferous forests.

    Science.gov (United States)

    Huo, Hong; Feng, Qi; Su, Yong-hong

    2014-01-01

    Understanding the factors that influence the distribution of understory vegetation is important for biological conservation and forest management. We compared understory species composition by multi-response permutation procedure and indicator species analysis between plots dominated by Qinghai spruce (Picea crassifolia Kom.) and Qilian juniper (Sabina przewalskii Kom.) in coniferous forests of the Qilian Mountains, northwestern China. Understory species composition differed markedly between the forest types. Many heliophilous species were significantly associated with juniper forest, while only one species was indicative of spruce forest. Using constrained ordination and the variation partitioning model, we quantitatively assessed the relative effects of two sets of explanatory variables on understory species composition. The results showed that topographic variables had higher explanatory power than did site conditions for understory plant distributions. However, a large amount of the variation in understory species composition remained unexplained. Forward selection revealed that understory species distributions were primarily affected by elevation and aspect. Juniper forest had higher species richness and α-diversity and lower β-diversity in the herb layer of the understory plant community than spruce forest, suggesting that the former may be more important in maintaining understory biodiversity and community stability in alpine coniferous forest ecosystems.

  18. Fire Regime along Latitudinal Gradients of Continuous to Discontinuous Coniferous Boreal Forests in Eastern Canada

    Directory of Open Access Journals (Sweden)

    Jeanne Portier

    2016-09-01

    Full Text Available Fire is the main disturbance in North American coniferous boreal forests. In Northern Quebec, Canada, where forest management is not allowed, the landscape is gradually constituted of more opened lichen woodlands. Those forests are discontinuous and show a low regeneration potential resulting from the cumulative effects of harsh climatic conditions and very short fire intervals. In a climate change context, and because the forest industry is interested in opening new territories to forest management in the north, it is crucial to better understand how and why fire risk varies from the north to the south at the transition between the discontinuous and continuous boreal forest. We used time-since-fire (TSF data from fire archives as well as a broad field campaign in Quebec’s coniferous boreal forests along four north-south transects in order to reconstruct the fire history of the past 150 to 300 years. We performed survival analyses in each transect in order to (1 determine if climate influences the fire risk along the latitudinal gradient; (2 fractionate the transects into different fire risk zones; and (3 quantify the fire cycle—defined as the time required to burn an area equivalent to the size of the study area—of each zone and compare its estimated value with current fire activity. Results suggest that drought conditions are moderately to highly responsible for the increasing fire risk from south to north in the three westernmost transects. No climate influence was observed in the last one, possibly because of its complex physical environment. Fire cycles are shortening from south to north, and from east to west. Limits between high and low fire risk zones are consistent with the limit between discontinuous and continuous forests, established based on recent fire activity. Compared to the last 40 years, fire cycles of the last 150–300 years are shorter. Our results suggest that as drought episodes are expected to become more frequent

  19. Increment-borer methods for determining fire history in coniferous forests

    Science.gov (United States)

    Stephen W. Barrett; Stephen F. Arno

    1988-01-01

    Describes use of increment borers for interpreting fire history in coniferous forests. These methods are intended for use in wildernesses, parks, and other natural areas where sawing cross-sections from fire-scarred trees is prohibited.

  20. The effect of temperature and moisture on trace gas emissions from deciduous and coniferous leaf litter

    National Research Council Canada - National Science Library

    Gritsch, Christine; Egger, Florian; Zehetner, Franz; Zechmeister‐Boltenstern, Sophie

    2016-01-01

    ... gases, i.e., carbon dioxide (CO 2 ), nitrous oxide (N 2 O), methane (CH 4 ), and nitric oxide (NO) coming from deciduous and coniferous leaf litter were measured at five temperatures and seven moisture contents...

  1. Diversity of predominant endophytic bacteria in European deciduous and coniferous trees

    National Research Council Canada - National Science Library

    Izumi, Hironari; Anderson, Ian C; Killham, Ken; Moore, Edward R.B

    2008-01-01

    The diversity of endophytic bacteria residing in root, stem, and leaf tissues was examined in coniferous and deciduous tree species, Scots pine (Pinus sylvestris L.), silver birch (Betula pendula Roth), and rowan (Sorbus aucuparia L...

  2. Coniferous Canopy BRF Simulation Based on 3-D Realistic Scene%Coniferous Canopy BRF Simulation Based on3-D Realistic Scene

    Institute of Scientific and Technical Information of China (English)

    WANG Xin-yun; GUO Zhi-feng; QINWen-hans; SUN Guo-qing

    2011-01-01

    It is difficulties for the computer simulation method to study radiation regime at large-scale.Simplified coniferous model was investigated in the present study.It makes the computer simulation methods such as L-systems and radiosity-graphics combined method (RGM) more powerful in remote sensing of heterogeneous coniferous forests over a large-scale region.L-systems is applied to render 3-D coniferous forest scenarios,and RGM model was used to calculate BRF (bidirectional reflectance factor) in visible and near-infrared regions.Results in this study show that in most cases both agreed well Meanwhile at a tree and forest level,the results are also good.

  3. Mercury in coniferous and deciduous upland forests in Northern New England, USA: implications from climate change

    Directory of Open Access Journals (Sweden)

    J. B. Richardson

    2015-07-01

    Full Text Available Climatic changes in the northeastern US are expected to cause coniferous stands to transition to deciduous stands over the next hundred years. Mercury (Hg sequestration in forest soils may change as a result. In order to understand potential effects of this transition, we studied aboveground vegetation and soils at paired coniferous and deciduous stands on eight mountains in Vermont and New Hampshire, US. Organic horizons at coniferous stands accumulated more Total Hg (THg (42 ± 6 g ha−1 than deciduous stands (30 ± 4 g ha−1. Total Hg pools in the mineral horizons were similar for coniferous (46 ± 8 g ha−1 and deciduous stands (45 ± 7 g ha−1. Soil properties (C, % clay, and pH explained 56 % of the variation in mineral soil Hg concentration when multiple regressed. Foliar and bole wood Hg concentrations were generally greater for coniferous species than deciduous species. We estimated Hg mean residence time (MRT in the organic and mineral horizons at coniferous and deciduous stands using a simple two-box model. Organic horizon MRT were longer at coniferous stands (183 ± 44 yr than deciduous stands (65 ± 15 yr. Mineral soil horizon MRT values were also longer for coniferous stands (386 ± 57 yr than for deciduous stands (188 ± 27 yr. We concluded that organic horizon Hg accumulation is influenced by vegetation type but mineral horizons are primarily affected by soil properties. Further investigations into the effect of vegetation type on volatilization, atmospheric deposition, and leaching rates are needed to constrain regional Hg cycling rates.

  4. [Butterflies (Lepidoptera, Diurna) in boreal forests of southeastern Russia: 1. Light coniferous forests].

    Science.gov (United States)

    Martynenko, A B

    2009-01-01

    Species groups formed in light coniferous forests prevailing in southeastern Russia are considered using the example of butterflies. Problems concerning the formation of species composition and its originality in some insects groups are discussed. A classification analysis of species checklists for twelve local faunas of Transbaikalia and the southern Russian Far East is performed. It is shown that the faunas of areas occupied by light coniferous forests have a common background.

  5. Mercury in coniferous and deciduous upland forests in northern New England, USA: implications of climate change

    Science.gov (United States)

    Richardson, J. B.; Friedland, A. J.

    2015-11-01

    Climatic changes in the northeastern US are expected to cause coniferous stands to transition to deciduous stands over the next hundred years. Mercury (Hg) sequestration in forest soils may change as a result. In order to understand potential effects of such a transition, we studied aboveground vegetation and soils at paired coniferous and deciduous stands on eight mountains in Vermont and New Hampshire, USA. Organic horizons at coniferous stands accumulated more total Hg (THg; 42 ± 6 g ha-1) than deciduous stands (30 ± 4 g ha-1). Total Hg pools in the mineral horizons were similar for coniferous (46 ± 8 g ha-1) and deciduous stands (45 ± 7 g ha-1). Soil properties (C, % clay, and pH) explained 56 % of the variation in mineral soil Hg concentration when multiply regressed. Foliar and bole wood Hg concentrations were generally greater for coniferous species than deciduous species. Using allometric equations, we estimated that aboveground accumulation of Hg in foliage and woody biomass was similar between vegetation types but that coniferous stands have significantly smaller annual litterfall fluxes (0.03 g ha-1 yr-1) than deciduous stands (0.24 g ha-1 yr-1). We conclude that organic horizon Hg accumulation is influenced by vegetation type but mineral horizon Hg accumulation is primarily controlled by soil properties. Further investigations into the effect of vegetation type on volatilization, atmospheric deposition, and leaching rates are needed to constrain regional Hg cycling rates.

  6. Microhabitat interactions of non-native pumpkinseed Lepomis gibbosus in a Mediterranean-type stream suggest no evidence for impact on endemic fishes

    Directory of Open Access Journals (Sweden)

    Top Nildeniz

    2016-01-01

    Full Text Available The pumpkinseed Lepomis gibbosus was introduced to Europe and parts of the Mediterranean Region more than 100 years ago. However, relatively little is known of its potential ecological impacts on the native species and freshwater ecosystems of Anatolia (Turkey, where the species is currently established in ponds and rivers. In this study, interactions between L. gibbosus and native and non-native stream fishes were investigated between June 2009 and May 2010 in Sarıçay Stream, a Mediterranean-type water course. Microhabitat preferences for depth, substratum composition, distance from bank and from vegetation, plant cover, velocity, turbidity and light intensity were studied by Constrained Quadratic Ordination. The species sampled in larger frequency of occurrence (and for which microhabitat relationships could be investigated comprised endemic Smyrna chub Petroleuciscus smyrnaeus and Aegean chub Squalius fellowesii, and non-native L. gibbosus (both juveniles and adults and topmouth gudgeon Pseudorasbora parva. Adult L. gibbosus were found to prefer locations closer to the bank with less turbid water, plant cover, light intensity, woody structure and with sandy substratum whilst avoiding riffle habitats with coarser debris, deeper water, dense submersed aquatic vegetation and higher velocities. These preferences overlapped with those for the other non-native species P. parva, but not with those for the endemic species and for L. gibbosus juveniles. The results of this study suggest that the potential for adverse impacts through competition for habitat of adult L. gibbosus with the native fish fauna is not apparent in Sarıçay Stream.

  7. SEASONALITY OF ANNUAL PLANT ESTABLISHMENT INFLUENCES THE INTERACTIONBETWEEN THE NON-NATIVE ANNUAL GRASS BROMUS MADRITENSIS SSP. RUBENS AND MOJAVE DESERT PERENNIALS

    Energy Technology Data Exchange (ETDEWEB)

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

    2004-01-01

    Competition between native and non-native species can change the composition and structure of plant communities, but in deserts the timing of non-native plant establishment can modulate their impacts to native species. In a field experiment, we varied densities of the non-native annual grass Bromus madritensis ssp. rubens around individuals of three native perennials--Larrea iridentata, Achnatherum hymenoides, and Pleuraphis rigida--in either winter or spring. Additional plots were prepared for the Same perennial species and seasons, but with a mixture of native annual species. Relative growth rates of perennial shoots (RGRs) declined with increasing Bromus biomass when Bromus that was established in winter had 2-3 mo of growth and high water use before perennial growth began. However, this high water use did not significantly reduce water potentials for the perennials, suggesting Bromus that established earlier depleted other soil resources, such as N, otherwise used by perennial plants. Spring-established Bromus had low biomass even at higher densities and did not effectively reduce RGRs, resulting in an overall lower impact to perennials than when Bromus was established in winter. Similarly, growth and reproduction of perennials with mixed annuals as neighbors did not differ from those with Bromus neighbors of equivalent biomass, but densities of these annuals did not support the high biomass necessary to reduce perennial growth. Thus, impacts of native Mojave Desert annuals to perennials are expected to be lower than those of Bromus because seed dormancy and narrow requirements for seedling survivorship produce densities and biomass lower than those achieved by Bromus. In comparing the effects of Bromus among perennial species, the impact of increased Bromus biomass on RGR was lower for Larrea than for the two perennial grasses, probably because Lurrea maintains low growth rates throughout the year, even after Bromus has completed its life cycle. This contrasts

  8. Raman spectroscopy and multivariate analysis for the rapid discrimination between native-like and non-native states in freeze-dried protein formulations.

    Science.gov (United States)

    Pieters, Sigrid; Vander Heyden, Yvan; Roger, Jean-Michel; D'Hondt, Matthias; Hansen, Laurent; Palagos, Bernard; De Spiegeleer, Bart; Remon, Jean-Paul; Vervaet, Chris; De Beer, Thomas

    2013-10-01

    This study investigates whether Raman spectroscopy combined with multivariate analysis (MVA) enables a rapid and direct differentiation between two classes of conformational states, i.e., native-like and non-native proteins, in freeze-dried formulations. A data set comprising of 99 spectra, both from native-like and various types of non-native freeze-dried protein formulations, was obtained by freeze-drying lactate dehydrogenase (LDH) as model protein under various conditions. Changes in the secondary structure in the solid freeze-dried proteins were determined through visual interpretation of the blank corrected second derivative amide I band in the ATR-FTIR spectra (further called FTIR spectra) and served as an independent reference to assign class labels. Exploratory analysis and supervised classification, using Principal Components Analysis (PCA) and Partial Least Squares - Linear Discriminant Analysis (PLS-LDA), respectively, revealed that Raman spectroscopy is with 95% accuracy able to correctly discriminate between native-like and non-native states in the tested freeze-dried LDH formulations. Backbone (i.e., amide III) and side chain sensitive spectral regions proved important for making the discrimination between both classes. As discrimination was not influenced by the spectral signals from the tested excipients, there was no need for blank corrections. The Raman model may allow direct and automated analysis of the investigated quality attribute, opening possibilities for a real time and in-line quality indication as a future step. However, the sensitivity of the method should be further investigated and where possible improved. Copyright © 2013 Elsevier B.V. All rights reserved.

  9. Why do students choose English as a medium of instruction? A Bourdieusian perspective on the study strategies of non-native English speakers

    DEFF Research Database (Denmark)

    Lueg, Klarissa; Lueg, Rainer

    2015-01-01

    by the Bourdieusian perspective, this relationship is not directly observable but operates through hidden mechanisms, such as cultural capital (relative English proficiency) and a better sense of gaming and positioning (career orientation). Business students from the lowest stratum self-select against EMI due......Taking a Bourdieusian perspective, we analyze the relevance of social background and capital for choosing English as a medium of instruction (EMI). Our work focuses on students with a non-native English-language background in a business school setting. Although proponents argue that EMI generally...

  10. Salinity tolerance of non-native suckermouth armoured catfish (Loricariidae: Pterygoplichthys) in south-eastern Mexico: implications for invasion and dispersal

    Science.gov (United States)

    Capps, Krista A.; Nico, Leo G.; Mendoza-Carranza, Manuel; Arevalo-Frias, Wendi; Ropicki, Andrew J.; Heilpern, Sebastian A.; Rodiles-Hernandez, Rocio

    2011-01-01

    1. Salinity tolerance is one of several important physiological attributes that determine invasion success and the pattern of dispersal of introduced aquatic organisms. Introduced freshwater fishes able to tolerate elevated salinities have the potential to invade and exploit brackish-water (mixohaline) environments and use estuaries and coastal waters as 'bridges' for dispersing from one coastal river system to another. 2. Several members of the neotropical suckermouth armoured catfish genus Pterygoplichthys (Siluriformes: Loricariidae) have established non-native populations in inland waters of North and Central America, Asia and islands in the Caribbean, and Pacific and Indian oceans. Loricariids are generally considered to be strictly freshwater; but a few naturally occur in mesohaline habitats. 3.Catch and habitat data from 2004–2005 and 2009–2011 fish surveys in the Grijalva–Usumacinta River delta region (south-eastern Mexico) confirmed that introduced Pterygoplichthys populations established in upstream freshwater sites (where these catfish are abundant) have recently dispersed into downstream oligohaline and mesohaline estuarine habitats. During 2009–2011 surveys, these non-native catfish — tentatively identified as P. pardalis or its hybrids — were found in sites with salinities ranging from 1 to 8 ppt (mean 5.2 ppt). 4.Acute-salinity experiments were conducted with Pterygoplichthys (110–302 mm standard length, N=140) captured in the Grijalva–Usumacinta Basin to determine upper salinity tolerance levels. Tests demonstrated that individuals maintained in salinities of 0.2 ppt were able to survive abrupt (acute) exposure to salinities up to 10 ppt with little mortality over 10 days (240 h experimental endpoint). A few individuals survived abrupt exposure to 11 and 12 ppt for 20 or more hours, although none survived more than a few hours at 16 ppt or greater. 5.These field and experimental results provide quantitative evidence that non-native

  11. Significant and persistent impact of timber harvesting on soil microbial communities in Northern coniferous forests.

    Science.gov (United States)

    Hartmann, Martin; Howes, Charles G; VanInsberghe, David; Yu, Hang; Bachar, Dipankar; Christen, Richard; Henrik Nilsson, Rolf; Hallam, Steven J; Mohn, William W

    2012-12-01

    Forest ecosystems have integral roles in climate stability, biodiversity and economic development. Soil stewardship is essential for sustainable forest management. Organic matter (OM) removal and soil compaction are key disturbances associated with forest harvesting, but their impacts on forest ecosystems are not well understood. Because microbiological processes regulate soil ecology and biogeochemistry, microbial community structure might serve as indicator of forest ecosystem status, revealing changes in nutrient and energy flow patterns before they have irreversible effects on long-term soil productivity. We applied massively parallel pyrosequencing of over 4.6 million ribosomal marker sequences to assess the impact of OM removal and soil compaction on bacterial and fungal communities in a field experiment replicated at six forest sites in British Columbia, Canada. More than a decade after harvesting, diversity and structure of soil bacterial and fungal communities remained significantly altered by harvesting disturbances, with individual taxonomic groups responding differentially to varied levels of the disturbances. Plant symbionts, like ectomycorrhizal fungi, and saprobic taxa, such as ascomycetes and actinomycetes, were among the most sensitive to harvesting disturbances. Given their significant ecological roles in forest development, the fate of these taxa might be critical for sustainability of forest ecosystems. Although abundant bacterial populations were ubiquitous, abundant fungal populations often revealed a patchy distribution, consistent with their higher sensitivity to the examined soil disturbances. These results establish a comprehensive inventory of bacterial and fungal community composition in northern coniferous forests and demonstrate the long-term response of their structure to key disturbances associated with forest harvesting.

  12. An exhaustive inventory of coniferous trees in an agricultural landscape

    Science.gov (United States)

    Rousselet, Jérôme; Roques, Alain; Garcia, Jacques

    2015-01-01

    Abstract Background Various species of forest trees are commonly used for ornamental purposes and are therefore frequently found in non-forest ecosystems. These trees constitute a significant component of the trees outside forests (TOF). Although increasingly recognized as prominent feature of agricultural lands and built-up areas, not much is known, however, about TOF since they are generally absent from forest inventories. New information In the present study, we focus on the coniferous tree species that constitute potential hosts for a forest defoliator, the pine processionary moth Thaumetopoea pityocampa Den. & Schiff. (Lepidoptera, Notodontidae). We carried out an exhaustive inventory of all pines (Pinus spp.), cedars (Cedrus spp.) and Douglas-fir (Pseudotsuga menziesii) in a 22 × 22 km study window located in the open-field region of Beauce in the centre of France. We recorded a total of 3834 individuals or small groups host trees corresponding a density of 7.9 occurrences per 100 ha. We provide the spatial coordinates of the points without differentiation between tree species. PMID:25733964

  13. An exhaustive inventory of coniferous trees in an agricultural landscape.

    Science.gov (United States)

    Rousselet, Jérôme; Roques, Alain; Garcia, Jacques; Rossi, Jean-Pierre

    2015-01-01

    Various species of forest trees are commonly used for ornamental purposes and are therefore frequently found in non-forest ecosystems. These trees constitute a significant component of the trees outside forests (TOF). Although increasingly recognized as prominent feature of agricultural lands and built-up areas, not much is known, however, about TOF since they are generally absent from forest inventories. In the present study, we focus on the coniferous tree species that constitute potential hosts for a forest defoliator, the pine processionary moth Thaumetopoeapityocampa Den. & Schiff. (Lepidoptera, Notodontidae). We carried out an exhaustive inventory of all pines (Pinus spp.), cedars (Cedrus spp.) and Douglas-fir (Pseudotsugamenziesii) in a 22 × 22 km study window located in the open-field region of Beauce in the centre of France. We recorded a total of 3834 individuals or small groups host trees corresponding a density of 7.9 occurrences per 100 ha. We provide the spatial coordinates of the points without differentiation between tree species.

  14. A fully polarimetric scattering model for a coniferous forest

    Science.gov (United States)

    Karam, M. A.; Fung, A. K.; Lopes, A.; Mougin, E.

    1991-01-01

    For an elliptically polarized plane wave exciting a coniferous forested canopy a fully polarimetric scattering model has been developed to account for the size and orientation distributions of each forest constituent. A canopy is divided into three layers over a rough interface. The upper two layers represent the crown with its constituents (leaves, stems, and branches). The lower layer stands for the trunks and the rough interface is the canopy-ground interface. For a plane wave exciting the canopy, the explicit expressions for the bistatic scattering coefficient associated with each scattering mechanism are given. For an elliptically polarized incidence wave, the present model can be recast in a form suitable for polarimetric wave synthesis. The model validation is justified by comparing the measured and the calculated values of the backscattering coefficients for a linearly polarized incident wave. The comparison is made over a wide range of frequencies and incident angles. Numerical simulations are conducted to calculate the radar polarization signature of the canopy for different incident frequencies and angles.

  15. Hyperarticulation of vowels enhances phonetic change responses in both native and non-native speakers of English: evidence from an auditory event-related potential study.

    Science.gov (United States)

    Uther, Maria; Giannakopoulou, Anastasia; Iverson, Paul

    2012-08-27

    The finding that hyperarticulation of vowel sounds occurs in certain speech registers (e.g., infant- and foreigner-directed speech) suggests that hyperarticulation may have a didactic function in facilitating acquisition of new phonetic categories in language learners. This event-related potential study tested whether hyperarticulation of vowels elicits larger phonetic change responses, as indexed by the mismatch negativity (MMN) component of the auditory event-related potential (ERP) and tested native and non-native speakers of English. Data from 11 native English-speaking and 10 native Greek-speaking participants showed that Greek speakers in general had smaller MMNs compared to English speakers, confirming previous studies demonstrating sensitivity of the MMN to language background. In terms of the effect of hyperarticulation, hyperarticulated stimuli elicited larger MMNs for both language groups, suggesting vowel space expansion does elicit larger pre-attentive phonetic change responses. Interestingly Greek native speakers showed some P3a activity that was not present in the English native speakers, raising the possibility that additional attentional switch mechanisms are activated in non-native speakers compared to native speakers. These results give general support for models of speech learning such as Kuhl's Native Language Magnet enhanced (NLM-e) theory. Crown Copyright © 2012. Published by Elsevier B.V. All rights reserved.

  16. The Effects of Anthropogenic Structures on Habitat Connectivity and the Potential Spread of Non-Native Invertebrate Species in the Offshore Environment.

    Directory of Open Access Journals (Sweden)

    Rachel D Simons

    Full Text Available Offshore structures provide habitat that could facilitate species range expansions and the introduction of non-native species into new geographic areas. Surveys of assemblages of seven offshore oil and gas platforms in the Santa Barbara Channel revealed a change in distribution of the non-native sessile invertebrate Watersipora subtorquata, a bryozoan with a planktonic larval duration (PLD of 24 hours or less, from one platform in 2001 to four platforms in 2013. We use a three-dimensional biophysical model to assess whether larval dispersal via currents from harbors to platforms and among platforms is a plausible mechanism to explain the change in distribution of Watersipora and to predict potential spread to other platforms in the future. Hull fouling is another possible mechanism to explain the change in distribution of Watersipora. We find that larval dispersal via currents could account for the increase in distribution of Watersipora from one to four platforms and that Watersipora is unlikely to spread from these four platforms to additional platforms through larval dispersal. Our results also suggest that larvae with PLDs of 24 hours or less released from offshore platforms can attain much greater dispersal distances than larvae with PLDs of 24 hours or less released from nearshore habitat. We hypothesize that the enhanced dispersal distance of larvae released from offshore platforms is driven by a combination of the offshore hydrodynamic environment, larval behavior, and larval release above the seafloor.

  17. Small but tough: What can ecophysiology of croaking gourami Trichopsis vittatus (Cuvier 1831) tell us about invasiveness of non-native fishes in Florida?

    Science.gov (United States)

    Schofield, Pam; Schulte, Jessica

    2016-01-01

    Trichopsis vittata (Cuvier, 1831) is a small, freshwater gourami (Fam: Osphronemidae) native to southeast Asia. It was first detected in Florida in the 1970s and seems to have persisted for decades in a small area. In this study, we documented T. vittata’s ecophysiological tolerances (salinity and low-temperature) and qualitatively compared them to published values for other sympatric non-native species that have successfully invaded much of the Florida peninsula. Trichopsis vittata survived acute salinity shifts to 16 psu and was able to survive up to 20 psu when salinity was raised more slowly (5 psu per week). In a cold-tolerance experiment, temperature was lowered from 24 °C at 1 °C hr-1 until fish died. Mean temperature at death (i.e., lower lethal limit) was 7.2 °C. Trichopsis vittata seems as tolerant or more tolerant than many other sympatric non-native fishes for the variables we examined. However, T. vittata is the only species that has not dispersed since its introduction. Species other than T. vittata have broadly invaded ranges, many of which include the entire lower third of the Florida peninsula. It is possible that tolerance to environmental parameters serves as a filter for establishment, wherein candidate species must possess the ability to survive abiotic extremes as a first step. However, a species’ ability to expand its geographic range may ultimately rely on a secondary set of criteria including biotic interactions and life-history variables.

  18. The Effects of Anthropogenic Structures on Habitat Connectivity and the Potential Spread of Non-Native Invertebrate Species in the Offshore Environment.

    Science.gov (United States)

    Simons, Rachel D; Page, Henry M; Zaleski, Susan; Miller, Robert; Dugan, Jenifer E; Schroeder, Donna M; Doheny, Brandon

    2016-01-01

    Offshore structures provide habitat that could facilitate species range expansions and the introduction of non-native species into new geographic areas. Surveys of assemblages of seven offshore oil and gas platforms in the Santa Barbara Channel revealed a change in distribution of the non-native sessile invertebrate Watersipora subtorquata, a bryozoan with a planktonic larval duration (PLD) of 24 hours or less, from one platform in 2001 to four platforms in 2013. We use a three-dimensional biophysical model to assess whether larval dispersal via currents from harbors to platforms and among platforms is a plausible mechanism to explain the change in distribution of Watersipora and to predict potential spread to other platforms in the future. Hull fouling is another possible mechanism to explain the change in distribution of Watersipora. We find that larval dispersal via currents could account for the increase in distribution of Watersipora from one to four platforms and that Watersipora is unlikely to spread from these four platforms to additional platforms through larval dispersal. Our results also suggest that larvae with PLDs of 24 hours or less released from offshore platforms can attain much greater dispersal distances than larvae with PLDs of 24 hours or less released from nearshore habitat. We hypothesize that the enhanced dispersal distance of larvae released from offshore platforms is driven by a combination of the offshore hydrodynamic environment, larval behavior, and larval release above the seafloor.

  19. A Study of Avoidance Strategy of Face Threat of Native Speaker and Non-Native Speaker by Using Goffman’s Face-Work Theory

    Directory of Open Access Journals (Sweden)

    Salmon Pandarangga

    2016-05-01

    Full Text Available The purpose of this study was to analyze the avoidance strategy of face threat by English native speaker and non-native speaker who learnt other language e.g. English. This study used Irving Goffman’s face-work theory and its relation to avoidance face threat as a framework. 2 participants (one Australian and one Indonesian took part in this study. Both participants were interviewed in English language in English speaking environment for about 30 minutes each. The participants were asked to tell about their hobbies with some open-ended questions. This study focused on spoken sentences produced by both interviewees that indicated avoidance of face threat. The findings revealed that the native speaker and non-native speaker reacted differently to avoid face threat. In addition, they also had their own strategy to avoid the face threat. This study concluded that different cultures significantly contributed to the strategy of avoidance of face threat. Permalink/DOI: http://dx.doi.org/10.15408/ijee.v2i2.3087

  20. Species Diversity Based on Vertical Structure as Indicators of Artificial Restoration for Coniferous Forests in Southwest China

    Institute of Scientific and Technical Information of China (English)

    ZHANG Qiaoying; ZHANG Yunchun; Eshetu Yirdaw; LUO Peng; YI Shaoliang; Wu Ning

    2006-01-01

    Five indices of species richness, species diversity and species evenness were used to assess α diversity of four types of coniferous forests undergone different artificial regeneration time. The study was based on the vertical structure of forests, involving growth-forms of total plants as well as vertical layers of woody plants. The results showed that, except for the fourth layer of woody plants, the vertical structure of the four forests exhibited significant difference in terms of their species richness, species diversity and species evenness, suggesting that α species diversity index provided more detailed information and was a better index reflecting the regeneration processes in this region. It was recommended that silvicultural management of artificially regenerated forests should be strengthened to conserve the biodiversity of the forests, optimize forest structure and, in the long run, promote sustainable development of forest ecosystems.

  1. Altitudinal variation in soil organic carbon stock in coniferous subtropical and broadleaf temperate forests in Garhwal Himalaya

    Directory of Open Access Journals (Sweden)

    Kumar Munesh

    2009-08-01

    Full Text Available Abstract Background The Himalayan zones, with dense forest vegetation, cover a fifth part of India and store a third part of the country reserves of soil organic carbon (SOC. However, the details of altitudinal distribution of these carbon stocks, which are vulnerable to forest management and climate change impacts, are not well known. Results This article reports the results of measuring the stocks of SOC along altitudinal gradients. The study was carried out in the coniferous subtropical and broadleaf temperate forests of Garhwal Himalaya. The stocks of SOC were found to be decreasing with altitude: from 185.6 to 160.8 t C ha-1 and from 141.6 to 124.8 t C ha-1 in temperature (Quercus leucotrichophora and subtropical (Pinus roxburghii forests, respectively. Conclusion The results of this study lead to conclusion that the ability of soil to stabilize soil organic matter depends negatively on altitude and call for comprehensive theoretical explanation

  2. Atmospheric deposition in coniferous and deciduous tree stands in Poland

    Science.gov (United States)

    Kowalska, Anna; Astel, Aleksander; Boczoń, Andrzej; Polkowska, Żaneta

    2016-05-01

    The objective of this study was to assess the transformation of precipitation in terms of quantity and chemical composition following contact with the crown layer in tree stands with varied species composition, to investigate the effect of four predominant forest-forming species (pine, spruce, beech, and oak) on the amount and composition of precipitation reaching forest soils, and to determine the sources of pollution in atmospheric precipitation in forest areas in Poland. The amount and chemical composition (pH, electric conductivity, alkalinity, and chloride, nitrate, sulfate, phosphate, ammonium, calcium, magnesium, sodium, potassium, iron aluminum, manganese, zinc, copper, total nitrogen, and dissolved organic carbon contents) of atmospheric (bulk, BP) and throughfall (TF) precipitation were studied from January to December 2010 on twelve forest monitoring plots representative of Polish conditions. The study results provided the basis for the determination of the fluxes of pollutants in the forest areas of Poland and allowed the comparison of such fluxes with values provided in the literature for European forest areas. The transformation of precipitation in the canopy was compared for different tree stands. The fluxes of substances in an open field and under canopy were influenced by the location of the plot, including the regional meteorological conditions (precipitation amounts), vicinity of the sea (effect of marine aerosols), and local level of anthropogenic pollution. Differences between the plots were higher in TF than in BP. The impact of the vegetation cover on the chemical composition of precipitation depended on the region of the country and dominant species in a given tree stand. Coniferous species tended to cause acidification of precipitation, whereas deciduous species increased the pH of TF. Pine and oak stands enriched precipitation with components that leached from the canopy (potassium, manganese, magnesium) to a higher degree than spruce and

  3. Non-native molluscan colonizers on deliberately placed shipwrecks in the Florida Keys, with description of a new species of potentially invasive worm-snail (Gastropoda: Vermetidae)

    Science.gov (United States)

    Granados-Cifuentes, Camila; Rawlings, Timothy A.; Sierwald, Petra; Collins, Timothy M.

    2017-01-01

    Artificial reefs created by deliberately sinking ships off the coast of the Florida Keys island chain are providing new habitat for marine invertebrates. This newly developing fouling community includes the previously reported invasive orange tube coral Tubastraea coccinea and the non-native giant foam oyster Hyotissa hyotis. New SCUBA-based surveys involving five shipwrecks spanning the upper, middle, and lower Florida Keys, show T. coccinea now also established in the lower Keys and H. hyotis likewise extending to new sites. Two additional mollusks found on the artificial reefs, the amathinid gastropod Cyclothyca pacei and gryphaeid oyster Hyotissa mcgintyi, the latter also common in the natural reef areas, are discussed as potentially non-native. A new species of sessile, suspension-feeding, worm-snail, Thylacodes vandyensis Bieler, Rawlings & Collins n. sp. (Vermetidae), is described from the wreck of the USNS Vandenberg off Key West and discussed as potentially invasive. This new species is compared morphologically and by DNA barcode markers to other known members of the genus, and may be a recent arrival from the Pacific Ocean. Thylacodes vandyensis is polychromatic, with individuals varying in both overall head-foot coloration and mantle margin color pattern. Females brood stalked egg capsules attached to their shell within the confines of their mantle cavity, and give rise to crawl-away juveniles. Such direct-developing species have the demonstrated capacity for colonizing habitats isolated far from their native ranges and establishing rapidly growing founder populations. Vermetid gastropods are common components of the marine fouling community in warm temperate and tropical waters and, as such, have been tagged as potentially invasive or with a high potential to be invasive in the Pacific Ocean. As vermetids can influence coral growth/composition in the Pacific and have been reported serving as intermediate hosts for blood flukes of loggerhead turtles

  4. Hyperspectral canopy reflectance as a predictor for root concentrations of nitrogen and carbon in native and non native grass species

    Science.gov (United States)

    Land managers, scientists, and crop professionals need real-time, inexpensive, and labor-saving methods to determine below-ground biomass and potential carbon (C) and nitrogen (N) inputs of that biomass. Remote sensing is a non-destructive tool that monitors vigor of vegetation and has been used t...

  5. Seasonal greenhouse gas and soil nutrient cycling in semi-arid native and non-native perennial grass pastures

    Science.gov (United States)

    Previous research indicates that photosynthetic metabolism of warm- and cool-season grass species affects greenhouse gas (GHG, (carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O))) emissions from soil. This information could help establish best management practices to mitigate GHGs and stor...

  6. [Modeling of forest landscape change in Xiaoxinganling mountains under different planting proportions of coniferous and broadleaved species].

    Science.gov (United States)

    Zhou, Yu-fei; He, Hong-shi; Bu, Ren-cang; Jin, Long-ru; Li, Xiu-zhen

    2008-08-01

    With spatially explicit landscape model (LANDIS), the dynamic change of forest landscape in Youhao Forest Bureau in Xiaoxinganling Mountains from 2001-2201 under 5 planting proportions of coniferous and broadleaved species, i.e., 100% broadleaved species, 70% broadleaved and 30% coniferous species, 50% broadleaved and 50% coniferous species, 30% broadleaved and 70% coniferous species, and 100% coniferous species, was studied, taking the forest under natural regeneration after harvesting as the control. The results showed that afforestation effectively promoted the recovery of forest resources, but single planting of coniferous species would lead to the area percent of broadleaved species lower than the control. When broadleaved species were planted only, the area percent of coniferous species was lower than the control. The area percent and aggregation index of Pinus koraiensis and Larix gmelini increased with increasing planting proportion of coniferous species, and those of Quercus mongolica increased with increasing planting proportion of broad-leaved species. Afforestation decreased the area percent of Betula phatyphylla, but had no significant effects on its aggregation index. Different afforestation strategies not only altered the species area percent, but also affected the species spatial pattern.

  7. Laboratory and field validation of a simple method for detecting four species of non-native freshwater fish using eDNA.

    Science.gov (United States)

    Davison, P I; Créach, V; Liang, W-J; Andreou, D; Britton, J R; Copp, G H

    2016-09-01

    This paper presents the first phase in the development and validation of a simple and reliable environmental (e)DNA method using conventional PCR to detect four species of non-native freshwater fish: pumpkinseed Lepomis gibbosus, sunbleak Leucaspius delineatus, fathead minnow Pimephales promelas and topmouth gudgeon Pseudorasbora parva. The efficacy of the approach was demonstrated in indoor tank (44 l) trials in which all four species were detected within 24 h. Validation was through two field trials, in which L. gibbosus was detected 6-12 h after its introduction into outdoor experimental ponds and P. parva was successfully detected in disused fish rearing ponds where the species was known to exist. Thus, the filtration of small (30 ml) volumes of pond water was sufficient to capture fish eDNA and the approach emphasised the importance of taking multiple water samples of sufficient spatial coverage for detecting species of random or patchy distribution.

  8. Development of phonological constancy: 19-month-olds, but not 15-month-olds, identify words in a non-native regional accent.

    Science.gov (United States)

    Mulak, Karen E; Best, Catherine T; Tyler, Michael D; Kitamura, Christine; Irwin, Julia R

    2013-01-01

    By 12 months, children grasp that a phonetic change to a word can change its identity (phonological distinctiveness). However, they must also grasp that some phonetic changes do not (phonological constancy). To test development of phonological constancy, sixteen 15-month-olds and sixteen 19-month-olds completed an eye-tracking task that tracked their gaze to named versus unnamed images for familiar words spoken in their native (Australian) and an unfamiliar non-native (Jamaican) regional accent of English. Both groups looked longer at named than unnamed images for Australian pronunciations, but only 19-month-olds did so for Jamaican pronunciations, indicating that phonological constancy emerges by 19 months. Vocabulary size predicted 15-month-olds' identifications for the Jamaican pronunciations, suggesting vocabulary growth is a viable predictor for phonological constancy development.

  9. Non-native Conformers of Cystic Fibrosis Transmembrane Conductance Regulator NBD1 Are Recognized by Hsp27 and Conjugated to SUMO-2 for Degradation.

    Science.gov (United States)

    Gong, Xiaoyan; Ahner, Annette; Roldan, Ariel; Lukacs, Gergely L; Thibodeau, Patrick H; Frizzell, Raymond A

    2016-01-22

    A newly identified pathway for selective degradation of the common mutant of the cystic fibrosis transmembrane conductance regulator (CFTR), F508del, is initiated by binding of the small heat shock protein, Hsp27. Hsp27 collaborates with Ubc9, the E2 enzyme for protein SUMOylation, to selectively degrade F508del CFTR via the SUMO-targeted ubiquitin E3 ligase, RNF4 (RING finger protein 4) (1). Here, we ask what properties of CFTR are sensed by the Hsp27-Ubc9 pathway by examining the ability of NBD1 (locus of the F508del mutation) to mimic the disposal of full-length (FL) CFTR. Similar to FL CFTR, F508del NBD1 expression was reduced 50-60% by Hsp27; it interacted preferentially with the mutant and was modified primarily by SUMO-2. Mutation of the consensus SUMOylation site, Lys(447), obviated Hsp27-mediated F508del NBD1 SUMOylation and degradation. As for FL CFTR and NBD1 in vivo, SUMO modification using purified components in vitro was greater for F508del NBD1 versus WT and for the SUMO-2 paralog. Several findings indicated that Hsp27-Ubc9 targets the SUMOylation of a transitional, non-native conformation of F508del NBD1: (a) its modification decreased as [ATP] increased, reflecting stabilization of the nucleotide-binding domain by ligand binding; (b) a temperature-induced increase in intrinsic fluorescence, which reflects formation of a transitional NBD1 conformation, was followed by its SUMO modification; and (c) introduction of solubilizing or revertant mutations to stabilize F508del NBD1 reduced its SUMO modification. These findings indicate that the Hsp27-Ubc9 pathway recognizes a non-native conformation of mutant NBD1, which leads to its SUMO-2 conjugation and degradation by the ubiquitin-proteasome system.

  10. When Anthropogenic River Disturbance Decreases Hybridisation between Non-Native and Endemic Cyprinids and Drives an Ecomorphological Displacement towards Juvenile State in Both Species.

    Directory of Open Access Journals (Sweden)

    Emmanuel Corse

    Full Text Available Understanding the impact of non-native species on native species is a major challenge in molecular ecology, particularly for genetically compatible fish species. Invasions are generally difficult to study because their effects may be confused with those of environmental or human disturbances. Colonized ecosystems are differently impacted by human activities, resulting in diverse responses and interactions between native and non-native species. We studied the dynamics between two Cyprinids species (invasive Chondrostoma nasus and endemic Parachondrostoma toxostoma and their hybrids in 16 populations (from allopatric to sympatric situations and from little to highly fragmented areas corresponding to 2,256 specimens. Each specimen was assigned to a particular species or to a hybrid pool using molecular identification (cytochrome b and 41 microsatellites. We carried out an ecomorphological analysis based on size, age, body shape, and diet (gut vacuity and molecular fecal contents. Our results contradicted our initial assumptions on the pattern of invasion and the rate of introgression. There was no sign of underperformance for the endemic species in areas where hybridisation occurred. In the unfragmented zone, the introduced species was found mostly downstream, with body shapes similar to those in allopatric populations while both species were found to be more insectivorous than the reference populations. However, high level of hybridisation was detected, suggesting interactions between the two species during spawning and/or the existence of hybrid swarm. In the disturbed zone, introgression was less frequent and slender body shape was associated with diatomivorous behaviour, smaller size (juvenile characteristics and greater gut vacuity. Results suggested that habitat degradation induced similar ecomorphological trait changes in the two species and their hybrids (i.e. a transition towards a pedomorphic state where the invasive species is more

  11. Increases in soil water content after the mortality of non-native trees in oceanic island forest ecosystems are due to reduced water loss during dry periods.

    Science.gov (United States)

    Hata, Kenji; Kawakami, Kazuto; Kachi, Naoki

    2016-03-01

    The control of dominant, non-native trees can alter the water balance of soils in forest ecosystems via hydrological processes, which results in changes in soil water environments. To test this idea, we evaluated the effects of the mortality of an invasive tree, Casuarina equisetifolia Forst., on the water content of surface soils on the Ogasawara Islands, subtropical islands in the northwestern Pacific Ocean, using a manipulative herbicide experiment. Temporal changes in volumetric water content of surface soils at 6 cm depth at sites where all trees of C. equisetifolia were killed by herbicide were compared with those of adjacent control sites before and after their mortality with consideration of the amount of precipitation. In addition, the rate of decrease in the soil water content during dry periods and the rate of increase in the soil water content during rainfall periods were compared between herbicide and control sites. Soil water content at sites treated with herbicide was significantly higher after treatment than soil water content at control sites during the same period. Differences between initial and minimum values of soil water content at the herbicide sites during the drying events were significantly lower than the corresponding differences in the control quadrats. During rainfall periods, both initial and maximum values of soil water contents in the herbicided quadrats were higher, and differences between the maximum and initial values did not differ between the herbicided and control quadrats. Our results indicated that the mortality of non-native trees from forest ecosystems increased water content of surface soils, due primarily to a slower rate of decrease in soil water content during dry periods.

  12. Non-native scientists, research dissemination and English neologisms: What happens in the early stages of reception and re-production?

    Directory of Open Access Journals (Sweden)

    Daniel Linder

    2016-11-01

    Full Text Available That the English language is the prevailing language in international scientific discourse is an undeniable fact for research professionals who are non-native speakers of English (NNSE. An exploratory, survey-based study of scientists in the experimental disciplines of neuroscience and medicine seeks to reveal, on the one hand, the habits of scientists who in their research practice come across neologisms in English and need to use them in oral and written scientific discourse in their own languages, and, on the other hand, their attitudes towards these neologisms and towards English as the language of international science. We found that all scientists write and publish their research articles (RAs in English and most submit them unrevised by native speakers of English. When first encountering a neologism in English, scientists tend to pay close attention to these new concepts, ideas or terms and very early in the reception process attempt to coin acceptable, natural-sounding Spanish equivalents for use in the laboratory and in their Spanish texts. In conjunction with the naturalized Spanish term, they often use the English neologism verbatim in a coexistent bilingual form, but they avoid using only the English term and very literal translations. These behaviors show an ambivalent attitude towards English (the language of both new knowledge reception and dissemination of their RAs and Spanish (used for local professional purposes and for popularization: while accepting to write in their acquired non-native language, they simultaneously recognize that their native language needs to preserve its specificity as a language of science.

  13. Soil fractal features of subalpine coniferous forests in western Sichuan under different anthropogenic disturbances

    Institute of Scientific and Technical Information of China (English)

    LIAO Yongmei; CHEN Jingsong

    2006-01-01

    Fractal theory,used to study natural figures and images with self-similarity but without characteristic lengths,offers an effective tool to investigate quantitatively the complex systems such as soil.In this paper,we have discussed about our study of the fractal features of the subalpine coniferous forests,soil particles,and microaggregates under different intensities of anthropogenic disturbances in the Miyaluo area of west Sichuan and investigated the effects of the disturbances on the forest soils attributed to different fractal dimensions.The study introduces a new way to investigate the recovery and reestablishment of subalpine coniferous forests.

  14. Formation, fate and leaching of chloroform in coniferous forest soils

    Energy Technology Data Exchange (ETDEWEB)

    Albers, Christian N., E-mail: calbers@ruc.dk [Dept. Geochemistry, Geological Survey of Denmark and Greenland, O. Voldgade 10, DK-1350, Copenhagen (Denmark); Laier, Troels; Jacobsen, Ole S. [Dept. Geochemistry, Geological Survey of Denmark and Greenland, O. Voldgade 10, DK-1350, Copenhagen (Denmark)

    2010-10-15

    Research highlights: {yields} Chloroform may be formed in coniferous forest soil. {yields} The formed chloroform may enter the groundwater in {mu}g/L concentrations. {yields} Clear seasonal patterns in chloroform formation in soil are observed. {yields} Sorption and degradation affects the fate of chloroform in forest soil. - Abstract: Chloroform is a common groundwater pollutant but also a natural compound in forest ecosystems. Leaching of natural chloroform from forest soil to groundwater was followed by regular analysis of soil air and groundwater from multilevel wells at four different sites in Denmark for a period of up to 4 a. Significant seasonal variation in chloroform was observed in soil air 0.5 m below surface ranging at one site from 120 ppb by volume in summer to 20 ppb during winter. With depth, the seasonal variation diminished gradually, ranging from 30 ppb in summer to 20 ppb during winter, near the groundwater table. Chloroform in the shallowest groundwater ranged from 0.5-1.5 {mu}g L{sup -1} at one site to 2-5 {mu}g L{sup -1} at another site showing no clear correlation with season. Comparing changes in chloroform in soil air versus depth with on-site recorded meteorological data indicated that a clear relationship appears between rain events and leaching of chloroform. Chloroform in top soil air co-varied with CO{sub 2} given a delay of 3-4 weeks providing evidence for its biological origin. This was confirmed during laboratory incubation experiments which further located the fermentation layer as the most chloroform producing soil horizon. Sorption of chloroform to soils, examined using {sup 14}C-CHCl{sub 3}, correlated with organic matter content, being high in the upper organic rich soils and low in the deeper more minerogenic soils. The marked decrease in chloroform in soil with depth may in part be due to microbial degradation which was shown to occur at all depths by laboratory tests using {sup 14}C-CHCl{sub 3}.

  15. Late pleistocene history of coniferous woodland in the mohave desert.

    Science.gov (United States)

    Wells, P V; Berger, R

    1967-03-31

    mesophytic, montane, coniferous-forest zone of ponderosa pine or white fir now occupying islands of relatively mesic environment on the highest mountains of the region. On the contrary, the uneven stocking of the lofty mountains of the Mohave Desert with mesephytic or boreal species and the trend toward endemism suggest a long history of isolation.

  16. Environmental Assessment for Integrated Natural Resources Management Plan Activities at Eglin Air Force Base, Florida

    Science.gov (United States)

    2013-01-28

    12) ● All feral hogs that are taken would be euthanized. ● Feral cats captured on Santa Rosa Island (SRI) are live trapped and delivered to the...native Animal Management and BASH Non-native animal control efforts center on feral hogs on the mainland reservation and feral cats , coyotes, and red...Nuisance and Non-native Animal Management and BASH ● All feral hogs that are taken would be euthanized. ● Feral cats captured on SRI are live trapped

  17. Mapping current and potential distribution of non-native Prosopis juliflora in the Afar region of Ethiopia

    Science.gov (United States)

    Wakie, Tewodros; Evangelista, Paul H.; Jarnevich, Catherine S.; Laituri, Melinda

    2014-01-01

    We used correlative models with species occurrence points, Moderate Resolution Imaging Spectroradiometer (MODIS) vegetation indices, and topo-climatic predictors to map the current distribution and potential habitat of invasive Prosopis juliflora in Afar, Ethiopia. Time-series of MODIS Enhanced Vegetation Indices (EVI) and Normalized Difference Vegetation Indices (NDVI) with 250 m2 spatial resolution were selected as remote sensing predictors for mapping distributions, while WorldClim bioclimatic products and generated topographic variables from the Shuttle Radar Topography Mission product (SRTM) were used to predict potential infestations. We ran Maxent models using non-correlated variables and the 143 species-occurrence points. Maxent generated probability surfaces were converted into binary maps using the 10-percentile logistic threshold values. Performances of models were evaluated using area under the receiver-operating characteristic (ROC) curve (AUC). Our results indicate that the extent of P. juliflora invasion is approximately 3,605 km2 in the Afar region (AUC = 0.94), while the potential habitat for future infestations is 5,024 km2 (AUC = 0.95). Our analyses demonstrate that time-series of MODIS vegetation indices and species occurrence points can be used with Maxent modeling software to map the current distribution of P. juliflora, while topo-climatic variables are good predictors of potential habitat in Ethiopia. Our results can quantify current and future infestations, and inform management and policy decisions for containing P. juliflora. Our methods can also be replicated for managing invasive species in other East African countries.

  18. Small scale temporal distribution of radiocesium in undisturbed coniferous forest soil: Radiocesium depth distribution profiles.

    Science.gov (United States)

    Teramage, Mengistu T; Onda, Yuichi; Kato, Hiroaki

    2016-04-01

    The depth distribution of pre-Fukushima and Fukushima-derived (137)Cs in undisturbed coniferous forest soil was investigated at four sampling dates from nine months to 18 months after the Fukushima nuclear power plant accident. The migration rate and short-term temporal variability among the sampling profiles were evaluated. Taking the time elapsed since the peak deposition of pre-Fukushima (137)Cs and the median depth of the peaks, its downward displacement rates ranged from 0.15 to 0.67 mm yr(-1) with a mean of 0.46 ± 0.25 mm yr(-1). On the other hand, in each examined profile considerable amount of the Fukushima-derived (137)Cs was found in the organic layer (51%-92%). At this moment, the effect of time-distance on the downward distribution of Fukushima-derived (137)Cs seems invisible as its large portion is still found in layers where organic matter is maximal. This indicates that organic matter seems the primary and preferential sorbent of radiocesium that could be associated with the physical blockage of the exchanging sites by organic-rich dusts that act as a buffer against downward propagation of radiocesium, implying radiocesium to be remained in the root zone for considerable time period. As a result, this soil section can be a potential source of radiation dose largely due to high radiocesium concentration coupled with its low density. Generally, such kind of information will be useful to establish a dynamic safety-focused decision support system to ease and assist management actions. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Mapping current and potential distribution of non-native Prosopis juliflora in the Afar region of Ethiopia.

    Directory of Open Access Journals (Sweden)

    Tewodros T Wakie

    Full Text Available We used correlative models with species occurrence points, Moderate Resolution Imaging Spectroradiometer (MODIS vegetation indices, and topo-climatic predictors to map the current distribution and potential habitat of invasive Prosopis juliflora in Afar, Ethiopia. Time-series of MODIS Enhanced Vegetation Indices (EVI and Normalized Difference Vegetation Indices (NDVI with 250 m2 spatial resolution were selected as remote sensing predictors for mapping distributions, while WorldClim bioclimatic products and generated topographic variables from the Shuttle Radar Topography Mission product (SRTM were used to predict potential infestations. We ran Maxent models using non-correlated variables and the 143 species- occurrence points. Maxent generated probability surfaces were converted into binary maps using the 10-percentile logistic threshold values. Performances of models were evaluated using area under the receiver-operating characteristic (ROC curve (AUC. Our results indicate that the extent of P. juliflora invasion is approximately 3,605 km2 in the Afar region (AUC  = 0.94, while the potential habitat for future infestations is 5,024 km2 (AUC  = 0.95. Our analyses demonstrate that time-series of MODIS vegetation indices and species occurrence points can be used with Maxent modeling software to map the current distribution of P. juliflora, while topo-climatic variables are good predictors of potential habitat in Ethiopia. Our results can quantify current and future infestations, and inform management and policy decisions for containing P. juliflora. Our methods can also be replicated for managing invasive species in other East African countries.

  20. Mapping current and potential distribution of non-native Prosopis juliflora in the Afar region of Ethiopia.

    Science.gov (United States)

    Wakie, Tewodros T; Evangelista, Paul H; Jarnevich, Catherine S; Laituri, Melinda

    2014-01-01

    We used correlative models with species occurrence points, Moderate Resolution Imaging Spectroradiometer (MODIS) vegetation indices, and topo-climatic predictors to map the current distribution and potential habitat of invasive Prosopis juliflora in Afar, Ethiopia. Time-series of MODIS Enhanced Vegetation Indices (EVI) and Normalized Difference Vegetation Indices (NDVI) with 250 m2 spatial resolution were selected as remote sensing predictors for mapping distributions, while WorldClim bioclimatic products and generated topographic variables from the Shuttle Radar Topography Mission product (SRTM) were used to predict potential infestations. We ran Maxent models using non-correlated variables and the 143 species- occurrence points. Maxent generated probability surfaces were converted into binary maps using the 10-percentile logistic threshold values. Performances of models were evaluated using area under the receiver-operating characteristic (ROC) curve (AUC). Our results indicate that the extent of P. juliflora invasion is approximately 3,605 km2 in the Afar region (AUC  = 0.94), while the potential habitat for future infestations is 5,024 km2 (AUC  = 0.95). Our analyses demonstrate that time-series of MODIS vegetation indices and species occurrence points can be used with Maxent modeling software to map the current distribution of P. juliflora, while topo-climatic variables are good predictors of potential habitat in Ethiopia. Our results can quantify current and future infestations, and inform management and policy decisions for containing P. juliflora. Our methods can also be replicated for managing invasive species in other East African countries.

  1. The invasion of non-native grasses into California grasslands has caused a shift in energy partitioning between latent and sensible heat flux, reduced albedo and higher surface temperatures

    Science.gov (United States)

    Koteen, L. E.; Harte, J.; Baldocchi, D. D.

    2012-12-01

    In California, native grasses have been largely displaced across millions of acres of grassland habitat by the invasion of non-native grasses from Mediterranean Europe. Although seemingly subtle, this shift in grass species composition has altered the water and energy cycles in these ecosystems due to a shift in life cycle strategy. Native California grasses are perennial and long-lived. To survive California's long summer drought, they possess deep roots to harvest moisture along the full depth of the soil profile. Aboveground, most California perennial grasses are bunchy and dense, covering the ground and restricting soil evaporation. Their growing season extends over most of the year, thus maintaining an unbroken interaction along the soil-plant-atmosphere continuum, and enabling the plants to draw water from deep soil layers well into the dry summer. In contrast, the now-dominant non-native grasses are annuals. They grow from seed each year when Autumn rains begin, and die with the onset of summer drought. Aboveground, non-native annuals are sparse relative to native perennials, and possess a shallow root system with the large majority of root biomass above 20 cm depth. To determine the impact of this land cover shift on ecosystem water and energy cycles, we measured the components of the surface energy balance at a grassland site in northern coastal California where remnant perennial grasses are found growing alongside regions that have undergone non-native invasion. Specifically, in locations dominated by each grass type, we measured net radiation and ground and canopy heat flux through the surface renewal method. We also measured midday PAR albedo to determine the impact of grassland invasion on energy capture. In three years of measurements, corresponding to average, wet and dry years, we found that energy partitioning during the growing season is similar between grass types. However, once non-native annual grasses senesce in mid to late spring, the ratio

  2. Minimizing measurement uncertainties of coniferous needle-leaf optical properties, part I: methodological review

    NARCIS (Netherlands)

    Yanez Rausell, L.; Schaepman, M.E.; Clevers, J.G.P.W.; Malenovsky, Z.

    2014-01-01

    Optical properties (OPs) of non-flat narrow plant leaves, i.e., coniferous needles, are extensively used by the remote sensing community, in particular for calibration and validation of radiative transfer models at leaf and canopy level. Optical measurements of such small living elements are, howeve

  3. Coniferous needle-leaves, shots and canopies : a remote sensing approach

    NARCIS (Netherlands)

    Yanez Rausell, L.

    2014-01-01

    Coniferous forests are important in the regulation of the Earth’s climate and thus continuous monitoring of these ecosystems is crucial to better understand potential responses to climate change. Optical remote sensing (RS) provides powerful methods for the estimation of essential climate

  4. Measurement of the dry deposition flux of NH3 on to coniferous forest

    NARCIS (Netherlands)

    Duyzer, J.H.; Verhagen, H.L.M.; Weststrate, J.H.; Bosveld, F.C.

    1992-01-01

    The dry deposition flux of NH3 to coniferous forest was determined by the micrometeorological gradient method using a 36m high tower. Aerodynamic characteristics of the site were studied, using a second tower erected in the forest 100m from the first. Fluxes and gradients of heat and momentum measur

  5. Rehabilitation of monotonous exotic coniferous plantations: A case study of spontaneous establishment of different tree species

    NARCIS (Netherlands)

    Jonásová, M.; Hees, van A.F.M.; Prach, K.

    2006-01-01

    Conversion of plantations of exotic coniferous species, such as Norway spruce (Picea abies), Douglas fir (Pseudotsuga menziesii) and Sitka spruce (Picea sitchensis), into more natural woodland is intended in two national parks in the province of Drenthe, The Netherlands. For that purpose, artificial

  6. Carbon and Nitrogen Transformations in Surface Soils Under Ermans Birch and Dark Coniferous Forests

    Institute of Scientific and Technical Information of China (English)

    DENG Xiao-Wen; HAN Shi-Jie; HU Yan-Ling; ZHOU Yu-Mei

    2009-01-01

    Soil samples were taken from an Ermans birch (Betula ermanii)-dark coniferous forest (Picea jezoensis and Abies nephrolepis) ecotone growing on volcanic ejecta in the northern slopc of Changbai Mountains of Northeast China,to compare soil carbon (C) and nitrogen (N) transformations in the two forests.The soil type is Umbri-Gelic Cambosols in Chinese Soil Taxonomy.Soil samples were incubated aerobically at 20 ℃ and field capacity of 700 g kg-1 over a period of 27 weeks.The amount of soil microbial biomass and net N mineralization were higher in the Ermans birch than the dark coniferous forest (P<0.05),whereas the cumulative C mineralization (as CO2 emission) in the dark coniferous forest exceeded that in the Ermans birch (P<0.05).Release of the cumulative dissolved organic C and dissolved organic N were greater in the Ermans birch than the dark coniferous forest (P<0.05).The results suggested that differences of forest types could result in considerable change in soil C and N transformations.

  7. Micrometeorological measurement of the dry deposition flux of sulphate and nitrate aerosols to coniferous forest

    NARCIS (Netherlands)

    Wyers, G.P.; Duyzer, J.H.

    1997-01-01

    Dry deposition fluxes of sulphate and nitrate have been determined over a coniferous canopy using the aerodynamic gradient technique. Vertical concentration gradients of sulphate and nitrate were measured with filters; the gradient of ammonium bisulphate was measured with thermodenuders. Filter meas

  8. Minimizing measurement uncertainties of coniferous needle-leaf optical properties, part I: methodological review

    NARCIS (Netherlands)

    Yanez Rausell, L.; Schaepman, M.E.; Clevers, J.G.P.W.; Malenovsky, Z.

    2014-01-01

    Optical properties (OPs) of non-flat narrow plant leaves, i.e., coniferous needles, are extensively used by the remote sensing community, in particular for calibration and validation of radiative transfer models at leaf and canopy level. Optical measurements of such small living elements are, howeve

  9. Coniferous needle-leaves, shots and canopies : a remote sensing approach

    NARCIS (Netherlands)

    Yanez Rausell, L.

    2014-01-01

    Coniferous forests are important in the regulation of the Earth’s climate and thus continuous monitoring of these ecosystems is crucial to better understand potential responses to climate change. Optical remote sensing (RS) provides powerful methods for the estimation of essential climate vari

  10. Invariant community structure of soil bacteria in subtropical coniferous and broadleaved forests.

    Science.gov (United States)

    Wang, Xiaoli; Wang, Xiaoling; Zhang, Weixin; Shao, Yuanhu; Zou, Xiaoming; Liu, Tao; Zhou, Lixia; Wan, Songze; Rao, Xingquan; Li, Zhian; Fu, Shenglei

    2016-01-12

    Soil bacteria may be influenced by vegetation and play important roles in global carbon efflux and nutrient cycling under global changes. Coniferous and broadleaved forests are two phyletically distinct vegetation types. Soil microbial communities in these forests have been extensively investigated but few studies have presented comparable data regarding the characteristics of bacterial communities in subtropical forests. We investigated soil bacterial biomass and community composition in three pairs of coniferous and broadleaved forests across a subtropical climatic gradient. We found that bacterial biomass differed between the coniferous and broadleaved forests across the subtropical climate gradient; however, this difference disappeared at some individual sites. In contrast, the same 90 bacterial genera were found in both forest types, and their relative abundances didn't differ between the forest types, with the exception of one genus that was more abundant in broadleaved forests. Soil nitrogen or moisture was associated with bacterial groups in the coniferous and broadleaved forests, respectively. Thus, we inferred that these forests can respond differently to future changes in nitrogen deposition or precipitation. This study highlights soil bacterial invariant community composition in contrasting subtropical forests and provides a new perspective on the potential response and feedback of forests to global changes.

  11. Belowground ectomycorrhizal fungal communities respond to liming in three southern Swedish coniferous forest stands

    DEFF Research Database (Denmark)

    Kjøller, Rasmus; Clemmensen, Karina

    2009-01-01

    In this study we report on changes in the belowground ectomycorrhizal fungal communities in southern Swedish coniferous forests as a consequence of liming with 3-7 ton limestone per hectare 16 years prior to the study. A total of 107 ectomycorrhizal fungi were identified from 969 independently...

  12. Shade Tolerance of Temperate Asian Bamboos: a Harbinger of their Naturalization in Pacific Northwest Coniferous Forests?

    Science.gov (United States)

    Bamboos native to temperate East Asian forests may be pre-adapted to floristically related coniferous forests in western North America that conspicuously lack large, rhizomatous grasses. Given the increasing opportunity for Asian bamboos to enter North America through horticulture, such pre-adaptat...

  13. Calibration of the L-MEB model over a coniferous and a deciduous forest

    DEFF Research Database (Denmark)

    Grant, Jennifer P.; Saleh-Contell, Kauzar; Wigneron, Jean-Pierre

    2008-01-01

    In this paper, the L-band Microwave Emission of the Biosphere (L-MEB) model used in the Soil Moisture and Ocean Salinity (SMOS) Level 2 Soil Moisture algorithm is calibrated using L-band (1.4 GHz) microwave measurements over a coniferous (Pine) and a deciduous (mixed/Beech) forest. This resulted...

  14. Absorption of Power Plants СО2 Emissions by Coniferous Tree Stands

    Directory of Open Access Journals (Sweden)

    Suvorova G.G.

    2015-12-01

    Full Text Available The article reviews the ability of coniferous (common pine, siberian larch and siberian spruce stands growing in 9 municipal districts of the Irkutsk region to absorb СО2 technogenic emission of heat power plants. (EIGAF index is suggested to characterize gas-absorbing (СО2–absorbing activity; the index reflects proportion between СО2 technogenic emission and photosynthetic productivity (GPP of coniferous tree stands. СО2–absorbing capacity in 8 of the monitored districts has been shown to significantly exceed the amount of carbon dioxide emission from heat power sector. The index values EIGAF=0.01-0.97 demonstrate that СО2 technogenic emission amounts to 1-97% of coniferous stands photosynthetic productivity in the areas under study. At the same time, the most industrially developed Angarsk district shows СО2 photosynthetic absorption to be 8-12 times lower than technogenic СО2 emission. Reasons of low gas-absorbing capacity of coniferous tree stands of this area are discussed.

  15. Private and public incomes in dehesas and coniferous forests in Andalusia, Spain

    Science.gov (United States)

    Paola Ovando; Pablo Campos; Jose L. Oviedo; Alejandro Caparrós

    2015-01-01

    We apply an ecosystem accounting system to estimate the total social income accrued from private and public products in a group of agroforestry farms in Andalusia (Spain). We provide bio-physical and economic indicators for two contrasting farm types, a sub-group of 15 publicly owned coniferous forests and a sub-group of 24 privately owned dehesa farms. Total social...

  16. Analyzing the ecosystem carbon dynamics of four European coniferous forests using a biogeochemistry model

    NARCIS (Netherlands)

    Churkina, G.; Tenhunen, J.; Thornton, P.; Falge, E.; Elbers, J.A.; Erhard, M.; Grünwald, T.; Kowalski, A.; Rannik, Ü.; Sprinz, D.

    2003-01-01

    This paper provides the first steps toward a regional-scale analysis of carbon (C) budgets. We explore the ability of the ecosystem model BIOME-BGC to estimate the daily and annual C dynamics of four European coniferous forests and shifts in these dynamics in response to changing environmental

  17. Rehabilitation of monotonous exotic coniferous plantations: A case study of spontaneous establishment of different tree species

    NARCIS (Netherlands)

    Jonásová, M.; Hees, van A.F.M.; Prach, K.

    2006-01-01

    Conversion of plantations of exotic coniferous species, such as Norway spruce (Picea abies), Douglas fir (Pseudotsuga menziesii) and Sitka spruce (Picea sitchensis), into more natural woodland is intended in two national parks in the province of Drenthe, The Netherlands. For that purpose, artificial

  18. Effective Control of Non-Native American Mink by Strategic Trapping in a River Catchment in Mainland Britain.

    Science.gov (United States)

    Reynolds, Jonathan C; Richardson, Suzanne M; Rodgers, Ben J E; Rodgers, Owain R K

    2013-04-01

    The introduction of American mink (Neovison vison; hereafter mink) into Europe has had severe impacts on many native wildlife species, including the water vole (Arvicola amphibius) in mainland Britain. Although trapping has been widely used to attempt to control mink, managers have little direct evidence of its effect on mink density or distribution, particularly where immigration of mink from nearby areas is inevitable. Such evidence is needed to justify the use of lethal methods in conservation policy. During 2006-2010 we removed mink from the River Monnow Catchment in western Britain, using track-recording rafts to monitor continuously for mink presence, guiding a strategic trapping effort. The area monitored and trapped was increased in stages, from a core sub-catchment with 109 km of water-course in 2006, to a 421-km(2) catchment with 203 km of water-course in 2009. In each successive sub-catchment, mink detection and capture rates declined rapidly to near-zero levels after trapping began. Detections and captures showed seasonal peaks in every year corresponding to known dispersal periods, but also declined steadily from year to year, with increasing periods in which we did not detect mink. These results suggested that each sub-catchment was cleared of mink within a few months, with subsequent captures attributable to immigration. On average, we detected each mink 5.1 times before capture (daily probability of detection = 0.059 per mink and raft), and trapped them 3.4 days after deploying traps in response. On average, mink entering the area were likely to have been present for less than 13 days before capture. Water voles had been extinct in the Monnow Catchment since the 1980s. During 2006-2008 (starting 6 months after mink trapping commenced), we released 700 captive-bred water voles into the treatment area to re-establish a wild population. Persistence of this population through the 4 years of the project was considered indicative of effective mink control

  19. "It's All about Give and Take," or Is It?: Where, When and How Do Native and Non-Native Uses of English Shape U. K. University Students' Representations of Each Other and Their Learning Experience?

    Science.gov (United States)

    Henderson, Juliet

    2009-01-01

    In this article the author draws on a larger project related to university internationalisation as represented by student voices to explore the part native and non-native speaker uses of English, as a marker of identity and legitimacy, play inside and outside formal curriculum delivery. Through the analysis of student voice constructions of…

  20. Investigating Native and Non-Native English-Speaking Teacher Raters' Judgements of Oral Proficiency in the College English Test-Spoken English Test (CET-SET)

    Science.gov (United States)

    Zhang, Ying; Elder, Catherine

    2014-01-01

    This study investigates the impact of raters' language background on their judgements of the speaking performance in the College English Test-Spoken English Test (CET-SET) of China, by comparing the rating patterns of non-native English-speaking (NNES) teacher raters, who are currently employed to assess performance on the CET-SET, with those…

  1. Comparison of Leaf Breakdown for Native and Non-native Riparian Species in Streams Draining Urban, Agricultural, and Forested Land Cover.

    Science.gov (United States)

    Powers, M. D.; Benfield, E. F.

    2005-05-01

    Organic matter breakdown rates in streams vary among riparian tree species and are dependent on a variety of in-stream biological, chemical, and physical factors. These factors and the composition and distribution of riparian vegetation are changed by anthropogenic modification of the landscape. This may result in altered energy flow through stream ecosystems that is reflected in changes in organic matter input and breakdown. The goal of this study was to compare leaf breakdown rates between a native (box elder, Acer negundo) and non-native (weeping willow, Salix babylonica) species among three land cover categories: urban, agricultural, and forested. We conducted this study over 14 weeks in 13 streams near Roanoke, Virginia. Box elder occurs naturally along disturbed riparian corridors in this region, while weeping willow has been actively planted for its aesthetic value. Our results indicate weeping willow breakdown rates were faster than box elder across all land cover categories. Breakdown rates for both species were slowest in the urban streams, intermediate in agricultural streams, and fastest in forested streams.

  2. Native and non-native speech sound processing and the neural mismatch responses: A longitudinal study on classroom-based foreign language learning.

    Science.gov (United States)

    Jost, Lea B; Eberhard-Moscicka, Aleksandra K; Pleisch, Georgette; Heusser, Veronica; Brandeis, Daniel; Zevin, Jason D; Maurer, Urs

    2015-06-01

    Learning a foreign language in a natural immersion context with high exposure to the new language has been shown to change the way speech sounds of that language are processed at the neural level. It remains unclear, however, to what extent this is also the case for classroom-based foreign language learning, particularly in children. To this end, we presented a mismatch negativity (MMN) experiment during EEG recordings as part of a longitudinal developmental study: 38 monolingual (Swiss-) German speaking children (7.5 years) were tested shortly before they started to learn English at school and followed up one year later. Moreover, 22 (Swiss-) German adults were recorded. Instead of the originally found positive mismatch response in children, an MMN emerged when applying a high-pass filter of 3 Hz. The overlap of a slow-wave positivity with the MMN indicates that two concurrent mismatch processes were elicited in children. The children's MMN in response to the non-native speech contrast was smaller compared to the native speech contrast irrespective of foreign language learning, suggesting that no additional neural resources were committed to processing the foreign language speech sound after one year of classroom-based learning. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Overexpression of a non-native deoxyxylulose-dependent vitamin B6 pathway in Bacillus subtilis for the production of pyridoxine.

    Science.gov (United States)

    Commichau, Fabian M; Alzinger, Ariane; Sande, Rafael; Bretzel, Werner; Meyer, Frederik M; Chevreux, Bastien; Wyss, Markus; Hohmann, Hans-Peter; Prágai, Zoltán

    2014-09-01

    Vitamin B6 is a designation for the vitamers pyridoxine, pyridoxal, pyridoxamine, and their respective 5'-phosphates. Pyridoxal 5'-phosphate, the biologically most-important vitamer, serves as a cofactor for many enzymes, mainly active in amino acid metabolism. While microorganisms and plants are capable of synthesizing vitamin B6, other organisms have to ingest it. The vitamer pyridoxine, which is used as a dietary supplement for animals and humans is commercially produced by chemical processes. The development of potentially more cost-effective and more sustainable fermentation processes for pyridoxine production is of interest for the biotech industry. We describe the generation and characterization of a Bacillus subtilis pyridoxine production strain overexpressing five genes of a non-native deoxyxylulose 5'-phosphate-dependent vitamin B6 pathway. The genes, derived from Escherichia coli and Sinorhizobium meliloti, were assembled to two expression cassettes and introduced into the B. subtilis chromosome. in vivo complementation assays revealed that the enzymes of this pathway were functionally expressed and active. The resulting strain produced 14mg/l pyridoxine in a small-scale production assay. By optimizing the growth conditions and co-feeding of 4-hydroxy-threonine and deoxyxylulose the productivity was increased to 54mg/l. Although relative protein quantification revealed bottlenecks in the heterologous pathway that remain to be eliminated, the final strain provides a promising basis to further enhance the production of pyridoxine using B. subtilis.

  4. Phonetic training and non-native speech perception--New memory traces evolve in just three days as indexed by the mismatch negativity (MMN) and behavioural measures.

    Science.gov (United States)

    Tamminen, Henna; Peltola, Maija S; Kujala, Teija; Näätänen, Risto

    2015-07-01

    Language-specific, automatically responding memory traces form the basis for speech sound perception and new neural representations can also evolve for non-native speech categories. The aim of this study was to find out how a three-day phonetic listen-and-repeat training affects speech perception, and whether it generates new memory traces. We used behavioural identification, goodness rating, discrimination, and reaction time tasks together with mismatch negativity (MMN) brain response registrations to determine the training effects on native Finnish speakers. We trained the subjects the voicing contrast in fricative sounds. Fricatives are not differentiated by voicing in Finnish, i.e., voiced fricatives do not belong to the Finnish phonological system. Therefore, they are extremely hard for Finns to learn. However, only after three days of training, the native Finnish subjects had learned to perceive the distinction. The results show striking changes in the MMN response; it was significantly larger on the second day after two training sessions. Also, the majority of the behavioural indicators showed improvement during training. Identification altered after four sessions of training and discrimination and reaction times improved throughout training. These results suggest remarkable language-learning effects both at the perceptual and pre-attentive neural level as a result of brief listen-and-repeat training in adult participants.

  5. Carnivory during Ontogeny of the Plagioscion squamosissimus: A Successful Non-Native Fish in a Lentic Environment of the Upper Paraná River Basin

    Science.gov (United States)

    Neves, Mayara Pereira; Delariva, Rosilene Luciana; Guimarães, Ana Tereza Bittencourt; Sanches, Paulo Vanderlei

    2015-01-01

    This study evaluated feeding patterns and ontogenetic variations in a non-native fish species (Plagioscion squamosissimus) in an isolated lake in the Upper Paraná River floodplain. Quarterly samplings were performed from April 2005 to February 2006 using plankton nets to capture larvae, seining nets for juveniles, and gill nets and trammel for adults. Stomach contents (n = 378) were examined according to the volumetric method in which the volume of each food item was estimated using graduated test tubes or a glass counting plate. During early development (larval stage), P. squamosissimus consumed mainly Cladocera and Copepoda. Juveniles showed a more diverse diet, including shrimp (Macrobrachium amazonicum), fish, aquatic insects (Trichoptera, Ephemeroptera, Chironomidae and pupae of Diptera) and plants. It was notable the high proportion of cannibalism (23.3%) in this stage. Adults consumed predominantly shrimp and fish. The use of food resources varied significantly between development stages (ANOSIM; r = 0.458; pjuvenile and larval stages, while M. amazonicum and other fishes caused the differences between adults and other ontogenetic stages. These results are confirmed by the relationship between standard length and developmental periods (ANCOVA; r2 = 0.94; p<0.0001). In general, there were low values of trophic niche breadth. The essentially carnivorous habit from the early stages of P. squamosissimus and the predominant use of M. amazonicum by adults have important roles in feeding patterns of the species, suggesting a major contribution to its success and establishment, especially in lentic environments. PMID:26524336

  6. Time-resolved visible and infrared absorption spectroscopy data obtained using photosystem I particles with non-native quinones incorporated into the A1 binding site.

    Science.gov (United States)

    Makita, Hiroki; Hastings, Gary

    2016-06-01

    Time-resolved visible and infrared absorption difference spectroscopy data at both 298 and 77 K were obtained using cyanobacterial menB (-) mutant photosystem I particles with several non-native quinones incorporated into the A1 binding site. Data was obtained for photosystem I particles with phylloquinone (2-methyl-3-phytyl-1,4-naphthoquinone), 2-bromo-1,4-naphthoquinone, 2-chloro-1,4-naphthoquinone, 2-methyl-1,4-naphthoquinone, 2,3-dibromo-1,4-naphthoquinone, 2,3-dichloro-1,4-naphthoquinone, and 9,10-anthraquinone incorporated. Transient absorption data were obtained at 487 and 703 nm in the visible spectral range, and 1950-1100 cm(-1) in the infrared region. Time constants obtained from fitting the time-resolved infrared and visible data are in good agreement. The measured time constants are crucial for the development of appropriate kinetic models that can describe electron transfer processes in photosystem I, "Modeling Electron Transfer in Photosystem I" Makita and Hastings (2016) [1].

  7. Time-resolved visible and infrared absorption spectroscopy data obtained using photosystem I particles with non-native quinones incorporated into the A1 binding site

    Directory of Open Access Journals (Sweden)

    Hiroki Makita

    2016-06-01

    Full Text Available Time-resolved visible and infrared absorption difference spectroscopy data at both 298 and 77 K were obtained using cyanobacterial menB− mutant photosystem I particles with several non-native quinones incorporated into the A1 binding site. Data was obtained for photosystem I particles with phylloquinone (2-methyl-3-phytyl-1,4-naphthoquinone, 2-bromo-1,4-naphthoquinone, 2-chloro-1,4-naphthoquinone, 2-methyl-1,4-naphthoquinone, 2,3-dibromo-1,4-naphthoquinone, 2,3-dichloro-1,4-naphthoquinone, and 9,10-anthraquinone incorporated. Transient absorption data were obtained at 487 and 703 nm in the visible spectral range, and 1950–1100 cm−1 in the infrared region. Time constants obtained from fitting the time-resolved infrared and visible data are in good agreement. The measured time constants are crucial for the development of appropriate kinetic models that can describe electron transfer processes in photosystem I, “Modeling Electron Transfer in Photosystem I” Makita and Hastings (2016 [1].

  8. CLASSIFICATION AND TYPES OF PREFERENTIAL FLOW FOR A DARK CONIFEROUS FOREST ECOSYSTEM IN THE UPPER REACH AREA OF THE YANGTZE RIVER

    Institute of Scientific and Technical Information of China (English)

    Jianzhi NIU; Xinxiao YU; Zhiqiang ZHANG; Yutao ZHAO

    2007-01-01

    Preferential flow is the ordinary phenomenon of rapid and non-equilibrium transport of water and solutes occurring in most soil. It causes latent pollution of ground and surface waters and affects runoff yield and flow concentration. This paper studies preferential flow for a dark coniferous ecosystem in the upper reach area of the Yangtze River, establishes a classification for the preferential flow and discusses types of preferential flow with a soil column experiment using a homemade apparatus and dye-tracer analysis. The preferential flow is mainly unsaturated gravitational flow in the upper layer of the slope deposit for mature forest soil, which is dominated by a wetness front, and the flow gradually transforms to macroporous flow as the soil layer deepens. The observed preferential flow in the young, middle-aged and over-mature forests that have grown on glacial lateral moraines is macroporous flow. The purpose of this research is to analyze systemically the behavior of soil water movement for a dark coniferous forest ecosystem in the upper reach area of the Yangtze River and to provide a theoretical basis for effective watershed management.

  9. Factor contribution to fire occurrence, size, and burn probability in a subtropical coniferous forest in East China

    Science.gov (United States)

    Guo, Zhixing; Li, Yijia

    2017-01-01

    The contribution of factors including fuel type, fire-weather conditions, topography and human activity to fire regime attributes (e.g. fire occurrence, size distribution and severity) has been intensively discussed. The relative importance of those factors in explaining the burn probability (BP), which is critical in terms of fire risk management, has been insufficiently addressed. Focusing on a subtropical coniferous forest with strong human disturbance in East China, our main objective was to evaluate and compare the relative importance of fuel composition, topography, and human activity for fire occurrence, size and BP. Local BP distribution was derived with stochastic fire simulation approach using detailed historical fire data (1990–2010) and forest-resource survey results, based on which our factor contribution analysis was carried out. Our results indicated that fuel composition had the greatest relative importance in explaining fire occurrence and size, but human activity explained most of the variance in BP. This implies that the influence of human activity is amplified through the process of overlapping repeated ignition and spreading events. This result emphasizes the status of strong human disturbance in local fire processes. It further confirms the need for a holistic perspective on factor contribution to fire likelihood, rather than focusing on individual fire regime attributes, for the purpose of fire risk management. PMID:28207837

  10. Factor contribution to fire occurrence, size, and burn probability in a subtropical coniferous forest in East China.

    Science.gov (United States)

    Ye, Tao; Wang, Yao; Guo, Zhixing; Li, Yijia

    2017-01-01

    The contribution of factors including fuel type, fire-weather conditions, topography and human activity to fire regime attributes (e.g. fire occurrence, size distribution and severity) has been intensively discussed. The relative importance of those factors in explaining the burn probability (BP), which is critical in terms of fire risk management, has been insufficiently addressed. Focusing on a subtropical coniferous forest with strong human disturbance in East China, our main objective was to evaluate and compare the relative importance of fuel composition, topography, and human activity for fire occurrence, size and BP. Local BP distribution was derived with stochastic fire simulation approach using detailed historical fire data (1990-2010) and forest-resource survey results, based on which our factor contribution analysis was carried out. Our results indicated that fuel composition had the greatest relative importance in explaining fire occurrence and size, but human activity explained most of the variance in BP. This implies that the influence of human activity is amplified through the process of overlapping repeated ignition and spreading events. This result emphasizes the status of strong human disturbance in local fire processes. It further confirms the need for a holistic perspective on factor contribution to fire likelihood, rather than focusing on individual fire regime attributes, for the purpose of fire risk management.

  11. Variation in litter decomposition-temperature relationships between coniferous and broadleaf forests in Huangshan Mountain,China

    Institute of Scientific and Technical Information of China (English)

    HE Xing-bing; SONG Fu-qiang; ZHANG Peng; LIN Yong-hui; TIAN Xing-jun; REN Li-li; CHEN Cheng; LI Xiao-na; Tan Hai-xia

    2007-01-01

    A study was conducted to identify the differences in the decompositions of leaf litter, lignin and carbohydrate between coniferous forest and broadleaf forest at 20℃ and 30℃ in Huangshan Mountain, Anhui Province, China. Results showed that at 20℃ mass loss of leaf litter driven by microbial decomposers was higher in broadleaf forest than that in coniferous forest, whereas the difference in mass loss of leaf litter was not significant at 30℃. The temperature increase did not affect the mass loss of leaf litter for coniferous forest treatment, but significantly reduced the decomposition rate for broadleaf forest treatment. The functional decomposers of microorganism in broadleaf forest produced a higher lignin decomposition rate at 20℃, compared to that in coniferous forest, but the difference in lignin decomposition was not found between two forest types at 30℃. Improved temperature increased the lignin decomposition for both broadleaf and coniferous forest. Additionally, the functional group of microorganism from broadleaf forest showed marginally higher carbohydrate loss than that from coniferous forest at both temperatures. Temperature increase reduced the carbohydrate decomposition for broadleaf forest, while only a little reduce was found for coniferous forest. Remarkable differences occurred in responses between most enzymes (Phenoloxidase, peroxidase, β-glucosidase and endocellulase) and decomposition rate of leaf litter to forest type and temperature, although there exist strong relationships between measured enzyme activities and decomposition rate in most cases. The reason is that more than one enzyme contribute to the mass loss of leaf litter and organic chemical components. In conclusion, at a community scale the coniferous and broadleaf forests differed in their temperature-decomposition relationships.

  12. Two Types of Ventilated Porometers Compared on Broadleaf and Coniferous Species 12

    Science.gov (United States)

    Johnson, Jon D.

    1981-01-01

    Two ventilated porometers (diffusion and steady-state) were compared on four broadleaf and five coniferous species. The diffusion porometer gave consistently lower conductance values for both types of species, reflecting a direct stomatal response to low chamber humidity. At high conductance values, the porometers produced a linear and nearly equal response, but the diffusion porometer was less sensitive at low conductance values. This was due to lower air flow (20% of the velocity in the steady-state porometer) and water vapor sorption (by its acrylic plastic chamber). The broadleaf species had less variation (R2 = 0.81) than did the coniferous species (R2 = 0.61), but, with the latter, there was better correspondence between the two porometers, possibly due to sampling technique. Conductance values were clustered by species. PMID:16661946

  13. In vitro fungistatic effects of natural coniferous resin from Norway spruce (Picea abies).

    Science.gov (United States)

    Rautio, M; Sipponen, A; Lohi, J; Lounatmaa, K; Koukila-Kähkölä, P; Laitinen, K

    2012-08-01

    Resins (rosin, pitch) are natural products of the coniferous trees and are antimicrobial against a wide range of microbes. The antifungal effectiveness of resin, purified from Norway spruce (Picea abies), was studied against human pathogenic fungi and yeasts with the agar plate diffusion tests and electron microscopy (EM). The fungistatic effect of these resin mixtures (resin salves) was tested against a set of Candida yeasts, dermatophytes, and opportunistic fungi. Transmission and scanning EM was done from samples of fungi (Trichophyton mentagrophytes). In agar diffusion tests, the resin was strongly antifungal against all dermatophytes tested, e.g., against all fungi of the genus Trichophyton, but it was not antifungal against the Candida yeasts or against the opportunistic fungi tested. According to EM, resin caused damages in the cell hyphae and cell wall structures. We conclude that, in the agar plate diffusion test, coniferous resins are strongly fungistatic against the dermatophytic fungi only.

  14. Nanocarbon materials obtained of coniferous trees in the composition of black powder

    OpenAIRE

    2012-01-01

    Obtained black powders from coniferous wood. The carbon content of up to 90% can be used in warfare, pyrotechnics and industries. In the Republic of Kazakhstan does not produce gunpowder. In the energy-intensive materials laboratory, developed industrial black powders (ordinary), composed of components produced in the republic of Kazakhstan. Sulfur, activated carbon, based on apricot seeds and rice husks, softwood sawdust, which have lower costs than their foreign counterparts.

  15. Nanocarbon materials obtained of coniferous trees in the composition of black powder

    Directory of Open Access Journals (Sweden)

    Zulkhair Mansurov

    2012-03-01

    Full Text Available Obtained black powders from coniferous wood. The carbon content of up to 90% can be used in warfare, pyrotechnics and industries. In the Republic of Kazakhstan does not produce gunpowder. In the energy-intensive materials laboratory, developed industrial black powders (ordinary, composed of components produced in the republic of Kazakhstan. Sulfur, activated carbon, based on apricot seeds and rice husks, softwood sawdust, which have lower costs than their foreign counterparts.

  16. Difference in uprooting resistance among coniferous species planted in soils of volcanic origin

    OpenAIRE

    Koizumi, Akio; Oonuma, Naoki; Sasaki, Yoshihisa; Takahashi, Kunihide

    2007-01-01

    Uprooting resistance against wind force for coniferous plantations in soils of volcanic origin was studied. The difference in uprooting resistance among Abies sachalinensis, Picea jezoensis, and Larix kaempferi was discussed. The sample site was set in Chitose plantations in Hokkaido Japan, where typhoon 0418 caused fatal uprooting damage in 2004. An uproot resistance index—the ratio of the geometrical moment of area for uprooted root-plate to the moment susceptibility to wind force—was defin...

  17. Evolution of an invasive species research program and implications for large-scale management of a non-native, invasive plant pathogen

    Science.gov (United States)

    Christopher A. Lee; Janice M. Alexander; Susan J. Frankel; Yana Valachovic

    2012-01-01

    We conducted a research needs assessment (RNA) in 2010 to gather opinions of "experts" and a larger public on research priorities for Phytophthora ramorum, the pathogen that causes sudden oak death in forest trees and Ramorum blight in ornamental plants. We place these 2010 findings in context with findings of similar P. ramorum...

  18. Altitudinal occurrence of non-native plant species (neophytes and their habitat affinity to anthropogenic biotopes in conditions of South-Western Slovakia

    Directory of Open Access Journals (Sweden)

    Beniak Michal

    2015-03-01

    Full Text Available Many ecological studies showed that species density (the number of species per unit area in nonnative organism groups of the mountain areas decreases with increasing altitude. The aim of the paper is to determine the variability in the incidence of non-native plant species (neophytes associated with the change in altitude and links of the invading taxons to reference habitat types, as well as their links to three ecologically very similar, however in natural conditions, different areas. In general, the most invaded habitats are those which are highly influenced by human activities. Firstly, data collection was conducted through field mapping of build-up areas in South-western Slovakia. Subsequently, with the assistance of ordination methods, we evaluated the level of association of invasive neophytes according to the set objectives. We found that altitude was an important factor determining variability of invasive neophytes’ occurrence. Total amount of habitats with invasive neophytes’ occurrence showed a linear increase along the altitudinal gradient. Many invasive neophytes adapted to abandoned habitats of upland territory were also able to grow along roads, and vice versa, abandoned and unused habitats of lowland areas created conditions for many typical invasive neophytes occurring along roads and habitats of gardens and yards. Railways of lowland areas provided habitats and means of spread of invasive woody neophytes. Gardens and yards were important sources of alien neophytes in all observed territories. Invasive neophyte Aster novi-belgii can be described as a very variable species tolerant to a wide range of factors limiting the spread of species along the elevation gradient.

  19. Carnivory during Ontogeny of the Plagioscion squamosissimus: A Successful Non-Native Fish in a Lentic Environment of the Upper Parana River Basin.

    Directory of Open Access Journals (Sweden)

    Mayara Pereira Neves

    Full Text Available This study evaluated feeding patterns and ontogenetic variations in a non-native fish species (Plagioscion squamosissimus in an isolated lake in the Upper Paraná River floodplain. Quarterly samplings were performed from April 2005 to February 2006 using plankton nets to capture larvae, seining nets for juveniles, and gill nets and trammel for adults. Stomach contents (n = 378 were examined according to the volumetric method in which the volume of each food item was estimated using graduated test tubes or a glass counting plate. During early development (larval stage, P. squamosissimus consumed mainly Cladocera and Copepoda. Juveniles showed a more diverse diet, including shrimp (Macrobrachium amazonicum, fish, aquatic insects (Trichoptera, Ephemeroptera, Chironomidae and pupae of Diptera and plants. It was notable the high proportion of cannibalism (23.3% in this stage. Adults consumed predominantly shrimp and fish. The use of food resources varied significantly between development stages (ANOSIM; r = 0.458; p<0.005, showing changes in food preferences during ontogeny. The Similarity Percentage Analysis (SIMPER indicated that Cladocera and Copepoda were responsible for the differences observed between the larval stages of pre-flexion, flexion and post-flexion. M. amazonicum and Chironomidae were responsible for the differences between juvenile and larval stages, while M. amazonicum and other fishes caused the differences between adults and other ontogenetic stages. These results are confirmed by the relationship between standard length and developmental periods (ANCOVA; r2 = 0.94; p<0.0001. In general, there were low values of trophic niche breadth. The essentially carnivorous habit from the early stages of P. squamosissimus and the predominant use of M. amazonicum by adults have important roles in feeding patterns of the species, suggesting a major contribution to its success and establishment, especially in lentic environments.

  20. Identification of STAC3 variants in non-Native American families with overlapping features of Carey-Fineman-Ziter syndrome and Moebius syndrome.

    Science.gov (United States)

    Telegrafi, Aida; Webb, Bryn D; Robbins, Sarah M; Speck-Martins, Carlos E; FitzPatrick, David; Fleming, Leah; Redett, Richard; Dufke, Andreas; Houge, Gunnar; van Harssel, Jeske J T; Verloes, Alain; Robles, Angela; Manoli, Irini; Engle, Elizabeth C; Jabs, Ethylin W; Valle, David; Carey, John; Hoover-Fong, Julie E; Sobreira, Nara L M

    2017-10-01

    Horstick et al. (2013) previously reported a homozygous p.Trp284Ser variant in STAC3 as the cause of Native American myopathy (NAM) in 5 Lumbee Native American families with congenital hypotonia and weakness, cleft palate, short stature, ptosis, kyphoscoliosis, talipes deformities, and susceptibility to malignant hyperthermia (MH). Here we present two non-Native American families, who were found to have STAC3 pathogenic variants. The first proband and her affected older sister are from a consanguineous Qatari family with a suspected clinical diagnosis of Carey-Fineman-Ziter syndrome (CFZS) based on features of hypotonia, myopathic facies with generalized weakness, ptosis, normal extraocular movements, cleft palate, growth delay, and kyphoscoliosis. We identified the homozygous c.851G>C;p.Trp284Ser variant in STAC3 in both sisters. The second proband and his affected sister are from a non-consanguineous, Puerto Rican family who was evaluated for a possible diagnosis of Moebius syndrome (MBS). His features included facial and generalized weakness, minimal limitation of horizontal gaze, cleft palate, and hypotonia, and he has a history of MH. The siblings were identified to be compound heterozygous for STAC3 variants c.851G>C;p.Trp284Ser and c.763_766delCTCT;p.Leu255IlefsX58. Given the phenotypic overlap of individuals with CFZS, MBS, and NAM, we screened STAC3 in 12 individuals diagnosed with CFZS and in 50 individuals diagnosed with MBS or a congenital facial weakness disorder. We did not identify any rare coding variants in STAC3. NAM should be considered in patients presenting with facial and generalized weakness, normal or mildly abnormal extraocular movement, hypotonia, cleft palate, and scoliosis, particularly if there is a history of MH. © 2017 Wiley Periodicals, Inc.

  1. Migratory monarchs wintering in California experience low infection risk compared to monarchs breeding year-round on non-native milkweed.

    Science.gov (United States)

    Satterfield, Dara A; Villablanca, Francis X; Maerz, John C; Altizer, Sonia

    2016-08-01

    Long-distance migration can lower infection risk for animal populations by removing infected individuals during strenuous journeys, spatially separating susceptible age classes, or allowing migrants to periodically escape from contaminated habitats. Many seasonal migrations are changing due to human activities including climate change and habitat alteration. Moreover, for some migratory populations, sedentary behaviors are becoming more common as migrants abandon or shorten their journeys in response to supplemental feeding or warming temperatures. Exploring the consequences of reduced movement for host-parasite interactions is needed to predict future responses of animal pathogens to anthropogenic change. Monarch butterflies (Danaus plexippus) and their specialist protozoan parasite Ophryocystis elektroscirrha (OE) provide a model system for examining how long-distance migration affects infectious disease processes in a rapidly changing world. Annual monarch migration from eastern North America to Mexico is known to reduce protozoan infection prevalence, and more recent work suggests that monarchs that forego migration to breed year-round on non-native milkweeds in the southeastern and south central Unites States face extremely high risk of infection. Here, we examined the prevalence of OE infection from 2013 to 2016 in western North America, and compared monarchs exhibiting migratory behavior (overwintering annually along the California coast) with those that exhibit year-round breeding. Data from field collections and a joint citizen science program of Monarch Health and Monarch Alert showed that infection frequency was over nine times higher for monarchs sampled in gardens with year-round milkweed as compared to migratory monarchs sampled at overwintering sites. Results here underscore the importance of animal migrations for lowering infection risk and motivate future studies of pathogen transmission in migratory species affected by environmental change. © The

  2. The distribution of the invasive non-native gastropod Crepidula fornicata in the Milford Haven Waterway, its northernmost population along the west coast of Britain

    Science.gov (United States)

    Bohn, Katrin; Richardson, Christopher A.; Jenkins, Stuart R.

    2015-12-01

    The invasive non-native gastropod Crepidula fornicata is well established in the Milford Haven Waterway (MHW) in south-west Wales, UK, since its first introduction to this ria in 1953. Whilst it reaches high densities within the MHW and has extended its range to the south of this ria, there has been very little northward expansion. Here, we report findings of a series of intertidal and subtidal surveys in 2009 and 2010 where we monitored the population density and the vertical distribution of C. fornicata at its northern range limit in Wales (the MHW). We also characterised the composition of the surface substrata of the seabed in the MHW to provide some insight into how the availability of certain settlement substrata may limit its distribution along the west coast of Britain. We found locally very dense aggregations (maximum 2748 ± 3859 individuals m-2, mean ± SD) in the shallow subtidal and low intertidal of the MHW. Subtidally, highest densities were found in areas of high gravel content (grain sizes ~16-256 mm), suggesting that the availability of this substrata type is beneficial for its establishment at a site. In the intertidal, on the other hand, high gravel content was indicative of low C. fornicata abundance, possibly because gravelly shores are an indicator of very exposed conditions that, at least in the intertidal, may result in high levels of early post-settlement mortality and low recruitment. C. fornicata was absent from the entrance of the MHW, possibly due to the lack of suitable settlement substrata. The presence of substantial populations in the MHW suggests that C. fornicata's population growth and potential expansion in Welsh coastal waters is not fully limited by prevailing environmental conditions in the region, but that other processes may affect its local distribution.

  3. Water holding effect of subalpine dark coniferous forest soil in Gongga Mountain, China

    Institute of Scientific and Technical Information of China (English)

    CHANG Zhi-hua; LU Zhao-hua; GUAN Wen-bin

    2003-01-01

    Because of the distinction of soil property and humus content, soil water content is not ideal to indicate whether it is suitable to the growth of plant. Mainly based on the PF-a numerical value denoting the water regime of soil and connected with the growth of plant, the study combined the moisture percentage of soil with PF to research in quantity the interrelation between the moisture percentage and PF in different succession phases of subalpine dark coniferous forest in Gongga Mountain. The results showed that: (1) In the same PF value, the moisture percentage in humus horizon increased gradually with the development of the succession of the dark coniferous forest; The moisture percentage of over-mature forest was the highest and>mature forest>half-mature forest>young growth forest; (2) With the increase of soil depth, the soil bulk density increased and the moisture percentage decreased, but the difference in the percentage of moisture was not notable in different succession phases. (3) In different succession series, the vegetation affected the soil water characteristics by increasing the soil organic matter, improving the soil construction, receding the soil bulk density and enhancing the soil porosity; (4) The humus horizon of the dark coniferous forest soil has the highest water holding capability in this region.

  4. Comparison of Characteristic of Water Balance between Evergreen Coniferous and Deciduous Broad-leaved Forests

    Science.gov (United States)

    Hisada, Shigeta; Senge, Masateru; Ito, Kengo; Maruyama, Toshisuke

    Hydrological observation was carried out at two basins occupied mainly by evergreen coniferous forest of Chamaecyparis obtusa and deciduous broad-leaved forest of Quercus crispula in order to clarify the influences of different forest type on water balance. The analysis of short-time period water-budget method showed that the evapotranspiration of coniferous forest was more than broad-leaved one. By calculating transpiration from Priestley-Taylor equation, intercepted evaporation was separated from evapotranspiration. The result of comparison of intercepted evaporation between two basin was that intercepted evaporation of coniferous basin was more than that of broad-leaved basin. From separating total runoff into direct and base flow components; it was shown that there was no difference in direct runoff of two basins, so the differences of total runoff of two basins were caused due to the difference of base flow. From the above analysis of water balance components, it is clarified that the different forest type influences the amount of intercepted evaporation and base flow.

  5. The effect of temperature and moisture on trace gas emissions from deciduous and coniferous leaf litter

    Science.gov (United States)

    Gritsch, Christine; Egger, Florian; Zehetner, Franz; Zechmeister-Boltenstern, Sophie

    2016-05-01

    The forest litter layer lies at the boundary between soil and atmosphere and is a major factor in biogeochemical cycles. While there are several studies on how the litter layer controls soil trace gas emissions, litter emissions itself are less well understood, and it is still unclear how important gases respond to changing temperature and moisture. In order to assess leaf litter gas exchange, we conducted laboratory incubation experiments in which the full set of climate relevant gases, i.e., carbon dioxide (CO2), nitrous oxide (N2O), methane (CH4), and nitric oxide (NO) coming from deciduous and coniferous leaf litter were measured at five temperatures and seven moisture contents. In addition, we compared litter and soil from different origin in terms of temperature/moisture responses of gas fluxes and investigated possible interactions between the two climate factors. Deciduous litter emitted more CO2 (up to 335 mg CO2-C kg-1 h-1) than coniferous litter, whereas coniferous litter released maximum amounts of NO (207 µg NO-N kg-1 h-1). N2O was only emitted from litter under very moist and warm conditions (>70% wet weight, >10°C). CH4 emissions were close to zero. Temperature sensitivities of litter emissions were generally lower than for soil emissions. Nevertheless, wet and warm conditions always enhanced litter emissions, suggesting a strong feedback effect of the litter layer to predicted future climate change.

  6. Longer-term effects of selective thinning on microarthropod communities in a late-successional coniferous forest

    Science.gov (United States)

    Peck, R.W.; Niwa, C.G.

    2005-01-01

    Microarthropod densities within late-successional coniferous forests thinned 16-41 yr before sampling were compared with adjacent unthinned stands to identify longer term effects of thinning on this community. Soil and forest floor layers were sampled separately on eight paired sites. Within the forest floor oribatid, mesostigmatid, and to a marginal extent, prostigmatid mites, were reduced in thinned stands compared with unthinned stands. No differences were found for Collembola in the forest floor or for any mite suborder within the soil. Family level examination of mesostigmatid and prostigmatid mites revealed significant differences between stand types for both horizons. At the species level, thinning influenced numerous oribatid mites and Collembola. For oribatid mites, significant or marginally significant differences were found for seven of 15 common species in the forest floor and five of 16 common species in soil. Collembola were affected less, with differences found for one of 11 common species in the forest floor and three of 13 common species in soil. Multivariate analysis of variance and ordination indicated that forest thinning had little influence on the composition of oribatid mite and collembolan communities within either the forest floor or soil. Differences in microclimate or in the accumulation of organic matter on the forest floor were likely most responsible for the observed patterns of abundance. Considering the role that microarthropods play in nutrient cycling, determining the functional response of a wide range of taxa to thinning may be important to effective ecosystem management.

  7. Comparison of soil bacterial communities in a natural hardwood forest and coniferous plantations in perhumid subtropical low mountains.

    Science.gov (United States)

    Lin, Yu-Te; Hu, Hsueh-Wen; Whitman, William B; Coleman, David C; Chiu, Chih-Yu

    2014-12-01

    The bacterial community of forest soils is influenced by environmental disturbance and/or meteorological temperature and precipitation. In this study, we investigated three bacterial communities in soils of a natural hardwood forest and two plantations of conifer, Calocedrus formosana and Cryptomeria japonica, in a perhumid, low mountain area. By comparison with our previous studies with similar temperature and/or precipitation, we aimed to elucidate how disturbance influences the bacterial community in forest soils and whether bacterial communities in similar forest types differ under different climate conditions. Analysis of 16S ribosomal RNA gene clone libraries revealed that Acidobacteria and Proteobacteria were the most abundant phyla in the three forest soil communities, with similar relative abundance of various bacterial groups. However, UniFrac analysis based on phylogenetic information revealed differences of bacterial communities between natural hardwood forest and coniferous plantation soils. The diversities of bacterial communities of the replanted Calocedrus and Cryptomeria forests were higher than that in natural hardwood forest. The bacterial diversity of these three forest soil were all higher than those in the same forest types at other locations with less precipitation or with lower temperature. In addition, the distribution of some of the most abundant operational taxonomic units in the three communities differed from other forest soils, including those related to Acidobacteria, α-, β- and γ-Proteobacteria. Reforestation could increase the bacterial diversity. Therefore, soil bacterial communities could be shaped by the forestry management practices and climate differences in warm and humid conditions.

  8. Overexpression of the primary sigma factor gene sigA improved carotenoid production by Corynebacterium glutamicum: Application to production of β-carotene and the non-native linear C50 carotenoid bisanhydrobacterioruberin

    Directory of Open Access Journals (Sweden)

    Hironori Taniguchi

    2017-06-01

    Full Text Available Corynebacterium glutamicum shows yellow pigmentation due to biosynthesis of the C50 carotenoid decaprenoxanthin and its glycosides. This bacterium has been engineered for production of various non-native cyclic C40 and C50 carotenoids such as β-carotene, astaxanthin or sarcinaxanthin. In this study, the effect of modulating gene expression more broadly by overexpression of sigma factor genes on carotenoid production by C. glutamicum was characterized. Overexpression of the primary sigma factor gene sigA improved lycopene production by recombinant C. glutamicum up to 8-fold. In C. glutamicum wild type, overexpression of sigA led to 2-fold increased accumulation of the native carotenoid decaprenoxanthin in the stationary growth phase. Under these conditions, genes related to thiamine synthesis and aromatic compound degradation showed increased RNA levels and addition of thiamine and the aromatic iron chelator protocatechuic acid to the culture medium enhanced carotenoid production when sigA was overexpressed. Deletion of the gene for the alternative sigma factor SigB, which is expected to replace SigA in RNA polymerase holoenzymes during transition to the stationary growth phase, also increased carotenoid production. The strategy of sigA overexpression could be successfully transferred to production of the non-native carotenoids β-carotene and bisanhydrobacterioruberin (BABR. Production of the latter is the first demonstration that C. glutamicum may accumulate a non-native linear C50 carotenoid instead of the native cyclic C50 carotenoid decaprenoxanthin.

  9. Coexistence of native-like and non-native partially unfolded ferricytochrome c on the surface of cardiolipin-containing liposomes.

    Science.gov (United States)

    Pandiscia, Leah A; Schweitzer-Stenner, Reinhard

    2015-01-29

    Cytochrome c, in spite of adopting a rather rigid structure around its prosthetic heme group, is rather diverse with regard to its function and structural variability. On the surface of the inner membrane of mitochondria it serves as an electron transfer carrier. However, at conditions which have not yet been unambiguously identified, cytochrome c can adopt a variety of non-native conformations, some of which exhibit peroxidase activity. Cardiolipin-containing liposomes have served as ideal model system to investigate the various modes of interaction between cytochrome c and the inner mitochrondrial membrane. We probed the binding of horse heart ferricytochrome c to liposomes formed with 20% tetraoleoyl cardiolipin (TOCL) and 80% dioleoyl-sn-glycero-3-phosphocholine (DOPC) as a function of lipid/protein ratio by fluorescence and visible circular dichroism spectroscopy. The obtained binding isotherms suggest that they reflect reversible binding processes, which excludes the possibility of significant protein insertion into the membrane. A global analysis of our data revealed the existence of two binding sites on the protein which causes rather different degrees of protein unfolding. We found that these two modes of interaction between protein and liposome led to conformational changes. While site 1 is relatively unaffected by NaCl, site 2 shows a more native-like state or a higher population of the native state in the presence of NaCl. At the highest utilized concentration of NaCl, there is only a 40% inhibition of the binding to site 2. We interpret our finding for this binding site as reflecting an equilibrium between electrostatically bound proteins with a high degree of unfolding and less unfolded proteins which bind either via H-bonding between lysine side chains and PO2(-) or hydrophobic interactions. With regard to site 2 binding, our results are reminiscent of the two-state equilibrium between a compact C and an extended E-state proposed by Pletneva and co

  10. 中国寒温带针叶林生物多样性的研究进展%Research Progress on the Cold Temperate Coniferous Forest Biodiversity in China

    Institute of Scientific and Technical Information of China (English)

    朱道光; 曾昭文; 王继丰; 崔福星; 倪红伟

    2014-01-01

    寒温带针叶林(北方针叶林或泰加林),主要分布于高纬度地区的一种主要森林类型,是地球上第二大陆地生物群区(仅次于热带森林),不仅是全球重要的木材资源分布区,而且是全球气候变化最显著的地区之一。过整理总结大量文献的基础上,提出在全球变化较为剧烈的环境背景下,认识寒温带针叶林植被的生态学效应,掌握寒温带针叶林各个时期物种变化的演替规律,进而为科学地管理我国寒温带针叶林提供合理的建议,以保证寒温带针叶林生态系统具有较高的生物多样性和生产力,具有重要的理论和实际意义。%Cold Temperate coniferous forest (taiga or boreal forest) is the second largest land biomes on the Earth (rank only second to tropical forests ) which mainly located in the high latitude, it is not only major distribution area of timber resources all over the world, but is also one of the most obvious global climate change area. By gathering and summarizing the extensive literatures, it is proposed that ecological effects on boreal coniferous forest vegetation at the condition of the serious global environmental change, and the succession law of species changes of boreal coniferous forest during various periods, in order to provide reasonable recommendations about scientific management of boreal coniferous forest, and it has important theoretical and practical significance that ensures boreal coniferous forest ecosystems with high biodiversity and productivity.

  11. Effects of mercury deposition and coniferous forests on the mercury contamination of fish in the South Central United States.

    Science.gov (United States)

    Drenner, Ray W; Chumchal, Matthew M; Jones, Christina M; Lehmann, Christopher M B; Gay, David A; Donato, David I

    2013-02-05

    Mercury (Hg) is a toxic metal that is found in aquatic food webs and is hazardous to human and wildlife health. We examined the relationship between Hg deposition, land coverage by coniferous and deciduous forests, and average Hg concentrations in largemouth bass (Micropterus salmoides)-equivalent fish (LMBE) in 14 ecoregions located within all or part of six states in the South Central U.S. In 11 ecoregions, the average Hg concentrations in 35.6-cm total length LMBE were above 300 ng/g, the threshold concentration of Hg recommended by the U.S. Environmental Protection Agency for the issuance of fish consumption advisories. Percent land coverage by coniferous forests within ecoregions had a significant linear relationship with average Hg concentrations in LMBE while percent land coverage by deciduous forests did not. Eighty percent of the variance in average Hg concentrations in LMBE between ecoregions could be accounted for by estimated Hg deposition after adjusting for the effects of coniferous forests. Here we show for the first time that fish from ecoregions with high atmospheric Hg pollution and coniferous forest coverage pose a significant hazard to human health. Our study suggests that models that use Hg deposition to predict Hg concentrations in fish could be improved by including the effects of coniferous forests on Hg deposition.

  12. Subpixel canopy cover estimation of coniferous forests in Oregon using SWIR imaging spectrometry

    Science.gov (United States)

    Lobell, David B.; Asner, Gregory P.; Law, Beverly E.; Treuhaft, Robert N.

    2001-03-01

    The percent cover of vegetation canopies is an important variable for many land-surface biophysical and biogeochemical models and serves as a useful measure of land cover change. Remote sensing methods to estimate the subpixel fraction of vegetation canopies with spectral mixture analysis (SMA) require knowledge of the reflectance properties of major land cover units, called endmembers. However, variability in endmember reflectance across space and time has limited the interpretation and general applicability of SMA approaches. In this study, a subpixel vegetation cover of coniferous forests in Oregon, United States, was successfully estimated by employing shortwave infrared reflectance measurements (SWIR2 region, 2080-2280 nm) collected by the NASA Airborne Visible Infrared Imaging Spectrometer (AVIRIS). The approach presented here, referred to as AutoSWIR [Asner and Lobell, 2000], was originally developed for semiarid and arid environments and exploits the low SWIR2 variability of materials found in most ecosystems. SWIR2 field spectra from Oregon were compared with spectra from an arid systems database, revealing significant differences only for soil reflectance. However, SWIR2 variability remained low, as indicated by field spectra and principal component analysis, and AutoSWIR was then modified to use coniferous forest spectra collected in Oregon. Subsequent high spatial resolution estimates of forest canopy cover agreed well with estimates from low-altitude air photos (rms = 3%), demonstrating the successful extension of AutoSWIR to a coniferous forest ecosystem. The generality of AutoSWIR facilitates accurate estimates of vegetation cover that can be automatically retrieved from SWIR2 spectral measurements collected by forthcoming spaceborne imaging spectrometers such as NASA's New Millenium Program EO-1 Hyperion. These estimates can then be used to characterize landscape heterogeneity important for land-surface, atmospheric, and biogeochemical research.

  13. The importance of micrometeorological variations for photosynthesis and transpiration in a boreal coniferous forest

    DEFF Research Database (Denmark)

    Schurgers, Guy; Lagergren, F.; Molder, M.

    2015-01-01

    the importance of vertical variations in light, temperature, CO2 concentration and humidity within the canopy for fluxes of photosynthesis and transpiration of a boreal coniferous forest in central Sweden. A leaf-level photosynthesis-stomatal conductance model was used for aggregating these processes to canopy...... abovecanopy and within-canopy humidity, and despite large gradients in CO2 concentration during early morning hours after nights with stable conditions, neither humidity nor CO2 played an important role for vertical heterogeneity of photosynthesis and transpiration....

  14. Comparison between Brazil and Canada as regards competitiveness in coniferous sawn timber production

    Directory of Open Access Journals (Sweden)

    Alexandre Nascimento de Almeida

    2013-09-01

    Full Text Available The objective of this study is to identify strengths and weaknesses of Brazil and Canada regarding the production of coniferous sawn timber, based on an opinion survey with entrepreneurs operating in that business segment. The method selected for use was cluster analysis and results led to the conclusion that Brazil's main strengths relate to the expansion potential of its domestic and export markets and also to the high productivity and profitability of its forests, while, as for Canada, in addition to having an extensive area with commercial forests, a major strength is the commitment of the Canadian government to provide adequate infrastructure for the sawn timber industry to operate effectively.

  15. Growth ring analysis of fossil coniferous woods from early cretaceous of Araripe Basin.

    Science.gov (United States)

    Pires, Etiene F; Guerra-Sommer, Margot

    2011-06-01

    Growth ring analysis on silicified coniferous woods from the Missão Velha Formation (Araripe Basin - Brazil) has yielded important information about periodicity of wood production during the Early Cretaceous in the equatorial belt. Despite warm temperatures, dendrological data indicate that the climate was characterized by cyclical alternation of dry and rainy periods influenced by cyclical precipitations, typical of tropical wet and dry or savanna climate. The abundance of false growth rings can be attributed to both occasional droughts and arthropod damage. The present climate data agree with palaeoclimatic models that inferred summer-wet biomes for the Late Jurassic/Early Cretaceous boundary in the southern equatorial belt.

  16. Scenario Modeling of Thermal Influence from Forest Fire Front on a Coniferous Tree Trunk

    Directory of Open Access Journals (Sweden)

    Baranovskiy Nikolay V.

    2016-01-01

    Full Text Available Scenario research results of heat transfer and tissue damage in three-layered tree trunk influenced by heat flux from forest fire are presented. The problem is solved in two-dimensional statement in polar coordinates. The typical range of influence parameters (heat flux from forest fire front, trunk radius, coniferous species, air temperature, duration of exposure and distance from fire line is considered. Temperature distributions in different moments of time are obtained. Condition of tree damage by forest fire influence is under consideration in this research. Information summarized using tables with scenario and fire consequences results.

  17. Scattering from a random layer embedded with dielectric needles. [for applications to coniferous vegetation

    Science.gov (United States)

    Eom, H. J.; Fung, A. K.

    1986-01-01

    Intensity scattering from a random layer imbedded with small dielectric needles is studied for applications to coniferous vegetation. The phase matrix of a thin needle whose length may be appreciable compared to the incident wavelength is presented. The effects of needle orientation on scattering is taken into account by averaging the phase function over angles of orientation. The backscattering coefficient from the layer is computed by solving the radiative transfer equation. The effects of operating frequency, orientation and size of a needle on like- and cross-backscattering are demonstrated. It was found that in backscattering angular trends are mainly controlled by the orientation of the needles.

  18. Thermal infrared as a tool to detect tree water stress in a coniferous forest

    Science.gov (United States)

    Nourtier, M.; Chanzy, A.; Bes, B.; Davi, H.; Hanocq, J. F.; Mariotte, N.; Sappe, G.

    2009-04-01

    In the context of climatic change, species area may move and so, a study of forest species vulnerability is on interest. In Mediterranean regions, trees can suffer of water stress due to drought during summer. Responses to environmental constraints are delayed in forest so it is necessary to anticipate risks in order to adapt management. It would be therefore interesting to localize areas where trees might be vulnerable to water stress. To detect such areas, the idea developed in this study is to map the severity of water stress, which may be linked to soil. Because vegetation surface temperature is linked to transpiration and so to water stress, the relevance of thermal infrared as a tool to detect water stress was explored. Past studies about surface temperature of forests at the planting scale did not lead to conclusive results. At this scale, important spatial and temporal variations of surface temperature, with a magnitude of about 10°C, can be registered but there is possibly a sizeable contribution of the undergrowth (Duchemin, 1998a, 1998b). In the other hand, important stress are not detectable, probably due to meteorological conditions (Pierce et al., 1990). During spring and summer 2008, an experimentation was carried out on the silver fir (Abies alba) forest of Mont Ventoux (south of France) to evaluate temporal variations at tree scale of the surface temperature in relation to water stress and climatic conditions. Two sites and three trees were chosen for measurements of surface temperature with a view to have different levels of water stress. Transpiration deficit is characterised by the ratio of actual transpiration to potential transpiration which is computed by the ISBA model (Noilhan et al., 1989) implemented by climatic observations made at the top of tree canopy. Sap flow measurements needed to calculate this ratio were completed on different trees of the sites. Climatic datas also allows building reference temperature and then surface

  19. Remote sensing of temperate coniferous forest lead area index - The influence of canopy closure, understory vegetation and background reflectance

    Science.gov (United States)

    Spanner, Michael A.; Pierce, Lars L.; Running, Steven W.; Peterson, David L.

    1990-01-01

    Consideration is given to the effects of canopy closure, understory vegetation, and background reflectance on the relationship between Landsat TM data and the leaf area index (LAI) of temperate coniferous forests in the western U.S. A methodology for correcting TM data for atmospheric conditions and sun-surface-sensor geometry is discussed. Strong inverse curvilinear relationships were found between coniferous forest LAI and TM bands 3 and 5. It is suggested that these inverse relationships are due to increased reflectance of understory vegetation and background in open stands of lower LAI and decreased reflectance of the overstory in closed canopy stands with higher LAI.

  20. Remote sensing of temperate coniferous forest lead area index - The influence of canopy closure, understory vegetation and background reflectance

    Science.gov (United States)

    Spanner, Michael A.; Pierce, Lars L.; Running, Steven W.; Peterson, David L.

    1990-01-01

    Consideration is given to the effects of canopy closure, understory vegetation, and background reflectance on the relationship between Landsat TM data and the leaf area index (LAI) of temperate coniferous forests in the western U.S. A methodology for correcting TM data for atmospheric conditions and sun-surface-sensor geometry is discussed. Strong inverse curvilinear relationships were found between coniferous forest LAI and TM bands 3 and 5. It is suggested that these inverse relationships are due to increased reflectance of understory vegetation and background in open stands of lower LAI and decreased reflectance of the overstory in closed canopy stands with higher LAI.