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Sample records for alien invasive slider

  1. Alien invasive slider turtle in unpredicted habitat: a matter of niche shift or of predictors studied?

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    Dennis Rödder

    Full Text Available BACKGROUND: Species Distribution Models (SDMs aim on the characterization of a species' ecological niche and project it into geographic space. The result is a map of the species' potential distribution, which is, for instance, helpful to predict the capability of alien invasive species. With regard to alien invasive species, recently several authors observed a mismatch between potential distributions of native and invasive ranges derived from SDMs and, as an explanation, ecological niche shift during biological invasion has been suggested. We studied the physiologically well known Slider turtle from North America which today is widely distributed over the globe and address the issue of ecological niche shift versus choice of ecological predictors used for model building, i.e., by deriving SDMs using multiple sets of climatic predictor. PRINCIPAL FINDINGS: In one SDM, predictors were used aiming to mirror the physiological limits of the Slider turtle. It was compared to numerous other models based on various sets of ecological predictors or predictors aiming at comprehensiveness. The SDM focusing on the study species' physiological limits depicts the target species' worldwide potential distribution better than any of the other approaches. CONCLUSION: These results suggest that a natural history-driven understanding is crucial in developing statistical models of ecological niches (as SDMs while "comprehensive" or "standard" sets of ecological predictors may be of limited use.

  2. Invasive alien birds in Denmark

    DEFF Research Database (Denmark)

    Fox, Anthony David; Heldbjerg, Henning; Nyegaard, Timme

    2015-01-01

    Avian Introduced Alien Species (IAS) constitute a threat to the integrity of native biodiversity, the economy and human health, so here we briefly review some of the problems posed by such species around the world in relation to such bird species in Denmark. A new European Union Regulation...... on Invasive Alien Species implemented in January 2015 establishes a framework for actions to combat alien species, which requires Member States to prevent the spread of alien species, provide early warning and rapid responses to their presence and management of established alien species where they occur. We...... show the importance of mechanisms such as DOF’s (Dansk Ornitologisk Forening, BirdLife Denmark) Atlas project, Common Bird Census (breeding and wintering species) and DOFbasen to contribute data on the current geographical and numerical distribution of the few serious alien avian species already...

  3. Invasive alien birds in Denmark

    DEFF Research Database (Denmark)

    Nyegaard, Timme; Heldbjerg, Henning; Fox, Anthony David

    Avian Introduced Alien Species (IAS) constitute a threat to the integrity of native biodiversity, the economy and human health, so here we briefly review some of the problems posed by such species around the world in relation to bird species in Denmark. A new European Union Regulation on Invasive...... the importance of mechanisms such as DOFs (Danish Ornithological Society, BirdLife Denmark) Atlas project, Common Bird Monitoring (breeding and wintering species) and DOFbasen to contribute data on the current geographical and numerical distribution of the few serious alien avian species already present...

  4. Assessment and Management of Invasive Alien Predators

    OpenAIRE

    Kirsty Park

    2004-01-01

    Although invasive alien species have been identified as the second greatest threat to biodiversity after habitat loss, characterizing and quantifying their impacts on native species and habitats remains a fundamental problem in conservation biology. Here, I review the techniques that are currently used to assess the impact of invasive alien species on biodiversity, highlighting both their uses in invasive species ecology and their limitations in establishing a causal relationship. Adopting a ...

  5. Invasive alien birds in Denmark

    DEFF Research Database (Denmark)

    Fox, Anthony David; Heldbjerg, Henning; Nyegaard, Timme

    2015-01-01

    Avian Introduced Alien Species (IAS) constitute a threat to the integrity of native biodiversity, the economy and human health, so here we briefly review some of the problems posed by such species around the world in relation to such bird species in Denmark. A new European Union Regulation...... show the importance of mechanisms such as DOF’s (Dansk Ornitologisk Forening, BirdLife Denmark) Atlas project, Common Bird Census (breeding and wintering species) and DOFbasen to contribute data on the current geographical and numerical distribution of the few serious alien avian species already...

  6. Uprooting and burial of invasive alien plants

    DEFF Research Database (Denmark)

    Kollmann, Johannes Christian; Brink-Jensen, Kasper; Frandsen, Sally I.

    2011-01-01

    Invasive alien plants are a problem for conservation management, and control of these species can be combined with habitat restoration. Subsoil burial of uprooted plants is a new method of mechanical control, which might be suitable in disturbed habitats. The method was tested in Rosa rugosa...... increased with fragment dry mass (0.5–168.5 g). After 18 months with harrowing the species was still resprouting, flowering, and fruiting, albeit with no difference between shrub margin and center. Resprouts were taller (26 cm) and coverage was higher (0–4%) after two compared with three times harrowing...

  7. [Alien species invasion in Southern China and its countermeasures].

    Science.gov (United States)

    Fan, Jihui; Li, Jiang; Cheng, Genwei

    2005-03-01

    Alien species invasion may cause serious ecological damage, resulting in ecological crisis and biodiversity comedown, and further menacing existing human environment. At present, the invasion of alien species has brought very serious damage to China's environment and society. The direct annual loss of its agro-forestry industry accounts for 574 billion RMB. Taking the alien species in Southern China as an example, this paper analyzed the bio-invasion approaches, mechanics and damages, and aiming at the characters of invaded area and concerned ecosystems and species, proposed several prevention measurements, i.e., pay attention to the phenomena of bio-invasion and to the basic researches on it; intensify the legislation and establish scientific strategies for introducing alien species; enforce the quarantine on invasive species and establish countrywide monitoring system on alien species; enhance people's defending consciousness; and strengthen international cooperation and collaboration.

  8. Modelling Hotspots for Invasive Alien Plants in India.

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    Dibyendu Adhikari

    Full Text Available Identification of invasion hotspots that support multiple invasive alien species (IAS is a pre-requisite for control and management of invasion. However, till recently it remained a methodological challenge to precisely determine such invasive hotspots. We identified the hotspots of alien species invasion in India through Ecological Niche Modelling (ENM using species occurrence data from the Global Biodiversity Information Facility (GBIF. The predicted area of invasion for selected species were classified into 4 categories based on number of model agreements for a region i.e. high, medium, low and very low. About 49% of the total geographical area of India was predicted to be prone to invasion at moderate to high levels of climatic suitability. The intersection of anthropogenic biomes and ecoregions with the regions of 'high' climatic suitability was classified as hotspot of alien plant invasion. Nineteen of 47 ecoregions of India, harboured such hotspots. Most ecologically sensitive regions of India, including the 'biodiversity hotspots' and coastal regions coincide with invasion hotspots, indicating their vulnerability to alien plant invasion. Besides demonstrating the usefulness of ENM and open source data for IAS management, the present study provides a knowledge base for guiding the formulation of an effective policy and management strategy for controlling the invasive alien species.

  9. Modelling Hotspots for Invasive Alien Plants in India.

    Science.gov (United States)

    Adhikari, Dibyendu; Tiwary, Raghuvar; Barik, Saroj Kanta

    2015-01-01

    Identification of invasion hotspots that support multiple invasive alien species (IAS) is a pre-requisite for control and management of invasion. However, till recently it remained a methodological challenge to precisely determine such invasive hotspots. We identified the hotspots of alien species invasion in India through Ecological Niche Modelling (ENM) using species occurrence data from the Global Biodiversity Information Facility (GBIF). The predicted area of invasion for selected species were classified into 4 categories based on number of model agreements for a region i.e. high, medium, low and very low. About 49% of the total geographical area of India was predicted to be prone to invasion at moderate to high levels of climatic suitability. The intersection of anthropogenic biomes and ecoregions with the regions of 'high' climatic suitability was classified as hotspot of alien plant invasion. Nineteen of 47 ecoregions of India, harboured such hotspots. Most ecologically sensitive regions of India, including the 'biodiversity hotspots' and coastal regions coincide with invasion hotspots, indicating their vulnerability to alien plant invasion. Besides demonstrating the usefulness of ENM and open source data for IAS management, the present study provides a knowledge base for guiding the formulation of an effective policy and management strategy for controlling the invasive alien species.

  10. Control techniques for invasive alien plants

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    Michele de Sá Dechoum

    2013-03-01

    Full Text Available Invasive alien species are recognized as a major threat to the conservation of biodiversity. These species should be managed based on local and regional environmental conditions. Control techniques were tested for ten invasive species in Santa Catarina State: the trees Casuarina equisetifolia, Hovenia dulcis, Psidium guajava, Syzygium cumini, and Terminalia catappa, and shrubs and herbs Rubus fruticosus, Furcraea foetida, Hedychium coronarium, Impatiens walleriana, and Tradescantia zebrina. Treatments applied for trees were cut stump, frill and girdling or ring-barking followed by herbicide application, while the other species were treated with foliar spray, application of herbicide on the root system, cut stump and herbicide injection. The active ingredients tested were Triclopyr, Glyphosate, and the combination of Triclopyr + Fluroxipyr in concentrations from 2 to 6%, according to the species. The cut stump method was efficient for all of the woody species, while ring-barking and frilling followed by herbicide application and basal bark application resulted in different levels of efficiency for the species tested. The most efficient method for herbs and shrubs was foliar spray, and the least efficient methods were cut stump and herbicide injection.

  11. Retrospection of Alien Invasive Forest Insect Pests in China

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Eleven species of alien invasive forest insect pests have been found since the early time that insect species had been taken recorded in China. Their origins, inland distribution, invasive time, hosts, causing damage are recorded in this paper for the evidence of biological invasion. Their control methods are also studied or discussed.

  12. Mycorrhizal status helps explain invasion success of alien plant species.

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    Menzel, Andreas; Hempel, Stefan; Klotz, Stefan; Moora, Mari; Pyšek, Petr; Rillig, Matthias C; Zobel, Martin; Kühn, Ingolf

    2017-01-01

    It is still debated whether alien plants benefit from being mycorrhizal, or if engaging in the symbiosis constrains their establishment and spread in new regions. We analyzed the association between mycorrhizal status of alien plant species in Germany and their invasion success. We compared whether the representation of species with different mycorrhizal status (obligate, facultative, or non-mycorrhizal) differed at several stages of the invasion process. We used generalized linear models to explain the occupied geographical range of alien plants, incorporating interactions of mycorrhizal status with plant traits related to morphology, reproduction, and life-history. Non-naturalized aliens did not differ from naturalized aliens in the relative frequency of different mycorrhizal status categories. Mycorrhizal status significantly explained the occupied range of alien plants; with facultative mycorrhizal species inhabiting a larger range than non-mycorrhizal aliens and obligate mycorrhizal plant species taking an intermediate position. Aliens with storage organs, shoot metamorphoses, or specialized structures promoting vegetative dispersal occupied a larger range when being facultative mycorrhizal. We conclude that being mycorrhizal is important for the persistence of aliens in Germany and constitutes an advantage compared to being non-mycorrhizal. Being facultative mycorrhizal seems to be especially advantageous for successful spread, as the flexibility of this mycorrhizal status may enable plants to use a broader set of ecological strategies.

  13. Invasive alien woody plants of the northern Cape

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    L. Henderson

    1991-12-01

    Full Text Available The frequency and abundance of invasive alien woody plants were recorded along roadsides and at watercourse crossings in 31% (90/286 of the quarter degree squares in the study area. The survey yielded 23 species of which the most prominent invaders were Prosopis spp. The most prominent remaining species were: Opuntia ficus-indica, Nicotiana glauca and Melia azedarach. The greatest abundance and diversity of alien invader plants were recorded near human settlements. More than half of the total recorded species have invaded perennial riverbanks. The episodic Molopo and Kuruman Rivers have been invaded almost exclusively by  Prosopis spp., which in places have formed extensive stands.

  14. Invasive alien woody plants of the Orange Free State

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    L. Henderson

    1991-12-01

    Full Text Available The frequency and abundance of invasive alien woody plants were recorded along roadsides and at watercourse crossings in 66% (151/230 of the quarter degree squares in the study area. The survey yielded 64 species of which the most prominent (in order of prominence in streambank habitats were:  Salix babylonica, Populus x  canescens, Acacia dealbata and  Salix fragilis (fide R.D. Meikle pers. comm . The most prominent species (in order of prominence in roadside and veld habitats were:  Opunlia ficus-indica, Prunus persica, Eucalyptus spp..  Rosa eglanteria, Pyracantha angustifolia and Acacia dealbata.Little invasion was recorded for most of the province. The greatest intensity of invasion was recorded along the perennial rivers and rocky hillsides in the moist grassland of the eastern mountain region bordering on Lesotho and Natal.

  15. Invasive alien woody plants of the eastern Cape

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    L. Henderson

    1992-12-01

    Full Text Available The frequency and abundance of invasive alien woody plants were recorded along roadsides and at watercourse crossings in 69.9% (151/216 of the quarter degree squares in the study area. The survey yielded 101 species of which the most prominent (in order of prominence in roadside and veld habitats were:  Opuntia ficus-indica, Acacia meamsii and A. cyclops. The most prominent species (in order of prominence in streambank habitats were:  A. meamsii, Populus x  canescens, Salix babylonica and  S. fragilis (fide R.D. Meikle.The greatest intensity of invasion was recorded in the wetter eastern parts and particularly in the vicinity of Port Elizabeth. Uitenhage, East London, Grahamstown, Hogsback and Stutterheim. There was relatively little invasion in the central and western dry interior except along watercourses.

  16. 外来侵袭物种的法律定义%Legal Definition on Alien Invasive Species

    Institute of Scientific and Technical Information of China (English)

    高敏

    2005-01-01

    Agriculture,economy,ecological environment and human health are heavily threatened by alien invasive species ,Alien invasive species is spreading in our country,How to prevent,control and destroy alien invasive species through systems and regulations is problem for related legislation to resolve,However,how to deline alien species,invasive and introduction is premise of legal control on alien invasive species,and determines scope and offect of legal control,through comparing and analyzing legal definition of other countries.legal definition on alien invasive species in our country is put forwarded in the article。

  17. Essential elements of online information networks on invasive alien species

    Science.gov (United States)

    Simpson, A.; Sellers, E.; Grosse, A.; Xie, Y.

    2006-01-01

    In order to be effective, information must be placed in the proper context and organized in a manner that is logical and (preferably) standardized. Recently, invasive alien species (IAS) scientists have begun to create online networks to share their information concerning IAS prevention and control. At a special networking session at the Beijing International Symposium on Biological Invasions, an online Eastern Asia-North American IAS Information Network (EA-NA Network) was proposed. To prepare for the development of this network, and to provide models for other regional collaborations, we compare four examples of global, regional, and national online IAS information networks: the Global Invasive Species Information Network, the Invasives Information Network of the Inter-American Biodiversity Information Network, the Chinese Species Information System, and the Invasive Species Information Node of the US National Biological Information Infrastructure. We conclude that IAS networks require a common goal, dedicated leaders, effective communication, and broad endorsement, in order to obtain sustainable, long-term funding and long-term stability. They need to start small, use the experience of other networks, partner with others, and showcase benefits. Global integration and synergy among invasive species networks will succeed with contributions from both the top-down and the bottom-up. ?? 2006 Springer.

  18. Worldwide Alien Invasion: A Methodological Approach to Forecast the Potential Spread of a Highly Invasive Pollinator

    Science.gov (United States)

    2016-01-01

    The ecological impacts of alien species invasion are a major threat to global biodiversity. The increasing number of invasion events by alien species and the high cost and difficulty of eradicating invasive species once established require the development of new methods and tools for predicting the most susceptible areas to invasion. Invasive pollinators pose serious threats to biodiversity and human activity due to their close relationship with many plants (including crop species) and high potential competitiveness for resources with native pollinators. Although at an early stage of expansion, the bumblebee species Bombus terrestris is becoming a representative case of pollinator invasion at a global scale, particularly given its high velocity of invasive spread and the increasing number of reports of its impacts on native bees and crops in many countries. We present here a methodological framework of habitat suitability modeling that integrates new approaches for detecting habitats that are susceptible to Bombus terrestris invasion at a global scale. Our approach did not include reported invaded locations in the modeling procedure; instead, those locations were used exclusively to evaluate the accuracy of the models in predicting suitability over regions already invaded. Moreover, a new and more intuitive approach was developed to select the models and evaluate different algorithms based on their performance and predictive convergence. Finally, we present a comprehensive global map of susceptibility to Bombus terrestris invasion that highlights priority areas for monitoring. PMID:26882479

  19. Worldwide Alien Invasion: A Methodological Approach to Forecast the Potential Spread of a Highly Invasive Pollinator.

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    André L Acosta

    Full Text Available The ecological impacts of alien species invasion are a major threat to global biodiversity. The increasing number of invasion events by alien species and the high cost and difficulty of eradicating invasive species once established require the development of new methods and tools for predicting the most susceptible areas to invasion. Invasive pollinators pose serious threats to biodiversity and human activity due to their close relationship with many plants (including crop species and high potential competitiveness for resources with native pollinators. Although at an early stage of expansion, the bumblebee species Bombus terrestris is becoming a representative case of pollinator invasion at a global scale, particularly given its high velocity of invasive spread and the increasing number of reports of its impacts on native bees and crops in many countries. We present here a methodological framework of habitat suitability modeling that integrates new approaches for detecting habitats that are susceptible to Bombus terrestris invasion at a global scale. Our approach did not include reported invaded locations in the modeling procedure; instead, those locations were used exclusively to evaluate the accuracy of the models in predicting suitability over regions already invaded. Moreover, a new and more intuitive approach was developed to select the models and evaluate different algorithms based on their performance and predictive convergence. Finally, we present a comprehensive global map of susceptibility to Bombus terrestris invasion that highlights priority areas for monitoring.

  20. Applications of Remote Sensing to Alien Invasive Plant Studies

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    Gregory P. Asner

    2009-06-01

    Full Text Available Biological invasions can affect ecosystems across a wide spectrum of bioclimatic conditions. Therefore, it is often important to systematically monitor the spread of species over a broad region. Remote sensing has been an important tool for large-scale ecological studies in the past three decades, but it was not commonly used to study alien invasive plants until the mid 1990s. We synthesize previous research efforts on remote sensing of invasive plants from spatial, temporal and spectral perspectives. We also highlight a recently developed state-of-the-art image fusion technique that integrates passive and active energies concurrently collected by an imaging spectrometer and a scanning-waveform light detection and ranging (LiDAR system, respectively. This approach provides a means to detect the structure and functional properties of invasive plants of different canopy levels. Finally, we summarize regional studies of biological invasions using remote sensing, discuss the limitations of remote sensing approaches, and highlight current research needs and future directions.

  1. The casual, naturalised and invasive alien flora of Zimbabwe based on herbarium and literature records

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    Alfred Maroyi

    2012-10-01

    Full Text Available Zimbabwe’s casual, naturalised and invasive alien plant species were analysed with regard to their habit, origin, mode or purpose of introduction and their invasion status in the country. This alien flora of 391 taxa belonged to 239 genera and 73 families, corresponding to 6.6%of the total flora of Zimbabwe. Of these, 153 (39.1% plant species were casual aliens, 154 (39.4% were naturalised and 84 (21.5% were invasive species. Most invasions in terms of numbers of alien species were in the central and eastern parts of the country. Asteraceae (53 species, Poaceae (48 species and Fabaceae sensu lato (49 species families were prominent in all the floristic regions of the country. Annual and perennial herbaceous species formed the majority of life forms of the casual, naturalised and invasive alien flora of Zimbabwe. Genera with the highest number of alien species were Ipomoea with nine species, Acacia and Euphorbiawith eight species each, Chenopodium and Senna with seven species each, Eucalyptus with six species, Oenothera, Physalis and Solanum with five species each. More than 49.6% of the alien plants in Zimbabwe originated primarily from South, Central and North America, followed by Europe (24.6%, Asia (23.8%, Africa (10.5% and Australasia (5.9%. Conservation implications: This research provides baseline information and historical invasion patterns of casual, naturalised and invasive alien flora in Zimbabwe. This inventory is a crucial starting point in trying to understand and initiate the management of biological invasions. This is also important for monitoring new introductions and management of existing alien plants in Zimbabwe.

  2. Dna c-values of 20 invasive alien species and 3 native species in south china

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    Gong Ni

    2014-01-01

    Full Text Available Cultivated fields and forests in South China are experiencing serious damage due to invasive alien plants. We investigated the relation between DNA C-values and invasiveness. The DNA C-values of 23 species ranged from 0.39 pg to 3.37 pg. Herbs, perennials and native species had higher mean DNA C-values than shrubs, annuals and invasive alien species. DNA C-values decreased with increasing invasiveness. Paederia scandens, a harmful native species, has the lowest DNA C-value among the perennials, indicating that native species with low nuclear content may also possess an invasive potential.

  3. State-space modeling indicates rapid invasion of an alien shrub in coastal dunes

    DEFF Research Database (Denmark)

    Damgaard, Christian Frølund; Nygaard, Bettina; Ejrnæs, Rasmus

    2011-01-01

    Invasion by alien plants has negative effects on coastal dunes. Monitoring local spread of invasive species depends on long-term data with sufficient spatial resolution. Bayesian state-space models are a new method for monitoring invasive plants based on unbalanced permanent-plot data. The method...

  4. Horticultural markets promote alien species invasions: an Estonian case study of herbaceous perennials

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    Merle Ööpik

    2013-06-01

    Full Text Available Gardening is a popular pastime, but commercial horticulture is responsible for the introduction of alien species and contributes to invasions in a variety of ways. Although an extensive international literature is available on plant invasions, it is still important at the national level to examine the influence of local factors. Accordingly, 17 nurseries in Estonia that cultivated and sold perennial alien species were selected, and a list of species and prices was compiled. The relationships between species status, and factors such as their abundance in the wild were examined statistically. A qualitative list of the nationally problematic species among herbaceous perennials was also completed. A total of 880 taxa were recorded, of which 10.3% were native and 89.7% alien. In all, 87.3% of the alien species were still confined to cultivated areas. The ecological and socio-economic characteristics of the taxa were described, and lists of the families of casual, naturalised and invasive aliens were provided. Both native and increasing wild alien species have a very similar profile on the market. Alien species that are less expensive, widely available and have more cultivars per species on the market are also more likely to escape. The invasive status and abundance of escaped aliens in an area increases with residence time. In general, socio-economic factors create new and reflect previous propagule pressures from commercial horticulture, which continuously increase the likelihood of alien species surviving and invading new areas. Our findings suggest that these national socio-economic market-related factors explain much of the invasiveness of various perennial ornamental species, and therefore regional and national authorities urgently need to regulate and control the ornamental plant trade to diminish the risk of new invasions.

  5. Distribution patterns of invasive alien species in Alabama, USA

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    Xiongwen Chen

    2012-12-01

    Full Text Available Invasive alien species (IAS cause environmental and economical problems. How to effectively manage all IAS at a large area is a challenge.Hypotheses about IAS (such as the “human activity” hypothesis, the “biotic acceptance” and the “biotic resistance” have been proposedfrom numerous studies. Here the state of Alabama in USA, widely occupied by IAS, is used as a case study for characterizing the emergentpatterns of IAS. The results indicate that most IAS are located in metropolitan areas and in the Black Belt area which is a historical intensiveland use area. There are positive relationships between the richness of IAS and the change of human population, the species richness and thenumber of endangered species, as well as the total road length and farmland area across Alabama. This study partially supports the abovethree hypotheses and provides a general pattern of local IAS. Based on possible processes related with IAS, some implications forstrategically managing local IAS are discussed.

  6. Effect of the Internet Commerce on Dispersal Modes of Invasive Alien Species

    Science.gov (United States)

    Lenda, Magdalena; Skórka, Piotr; Knops, Johannes M. H.; Moroń, Dawid; Sutherland, William J.; Kuszewska, Karolina; Woyciechowski, Michał

    2014-01-01

    The spread of invasive alien plants has considerable environmental and economic consequences, and is one of the most challenging ecological problems. The spread of invasive alien plant species depends largely on long-distance dispersal, which is typically linked with human activity. The increasing domination of the internet will have impacts upon almost all components of our lives, including potential consequences for the spread of invasive species. To determine whether the rise of Internet commerce has any consequences for the spread of invasive alien plant species, we studied the sale of thirteen of some of the most harmful Europe invasive alien plant species sold as decorative plants from twenty-eight large, well known gardening shops in Poland that sold both via the Internet and through traditional customer sales. We also analyzed temporal changes in the number of invasive plants sold in the largest Polish internet auction portal. When sold through the Internet invasive alien plant species were transported considerably longer distances than for traditional sales. For internet sales, seeds of invasive alien plant species were transported further than were live plants saplings; this was not the case for traditional sales. Also, with e-commerce the shape of distance distribution were flattened with low skewness comparing with traditional sale where the distributions were peaked and right-skewed. Thus, e-commerce created novel modes of long-distance dispersal, while traditional sale resembled more natural dispersal modes. Moreover, analysis of sale in the biggest Polish internet auction portal showed that the number of alien specimens sold via the internet has increased markedly over recent years. Therefore internet commerce is likely to increase the rate at which ecological communities become homogenized and increase spread of invasive species by increasing the rate of long distance dispersal. PMID:24932498

  7. Effect of the internet commerce on dispersal modes of invasive alien species.

    Science.gov (United States)

    Lenda, Magdalena; Skórka, Piotr; Knops, Johannes M H; Moroń, Dawid; Sutherland, William J; Kuszewska, Karolina; Woyciechowski, Michał

    2014-01-01

    The spread of invasive alien plants has considerable environmental and economic consequences, and is one of the most challenging ecological problems. The spread of invasive alien plant species depends largely on long-distance dispersal, which is typically linked with human activity. The increasing domination of the internet will have impacts upon almost all components of our lives, including potential consequences for the spread of invasive species. To determine whether the rise of Internet commerce has any consequences for the spread of invasive alien plant species, we studied the sale of thirteen of some of the most harmful Europe invasive alien plant species sold as decorative plants from twenty-eight large, well known gardening shops in Poland that sold both via the Internet and through traditional customer sales. We also analyzed temporal changes in the number of invasive plants sold in the largest Polish internet auction portal. When sold through the Internet invasive alien plant species were transported considerably longer distances than for traditional sales. For internet sales, seeds of invasive alien plant species were transported further than were live plants saplings; this was not the case for traditional sales. Also, with e-commerce the shape of distance distribution were flattened with low skewness comparing with traditional sale where the distributions were peaked and right-skewed. Thus, e-commerce created novel modes of long-distance dispersal, while traditional sale resembled more natural dispersal modes. Moreover, analysis of sale in the biggest Polish internet auction portal showed that the number of alien specimens sold via the internet has increased markedly over recent years. Therefore internet commerce is likely to increase the rate at which ecological communities become homogenized and increase spread of invasive species by increasing the rate of long distance dispersal.

  8. Ecological Risk Assessment with MCDM of Some Invasive Alien Plants in China

    Science.gov (United States)

    Xie, Guowen; Chen, Weiguang; Lin, Meizhen; Zheng, Yanling; Guo, Peiguo; Zheng, Yisheng

    Alien plant invasion is an urgent global issue that threatens the sustainable development of the ecosystem health. The study of its ecological risk assessment (ERA) could help us to prevent and reduce the invasion risk more effectively. Based on the theory of ERA and methods of the analytic hierarchy process (AHP) of multi-criteria decision-making (MCDM), and through the analyses of the characteristics and processes of alien plant invasion, this paper discusses the methodologies of ERA of alien plant invasion. The assessment procedure consisted of risk source analysis, receptor analysis, exposure and hazard assessment, integral assessment, and countermeasure of risk management. The indicator system of risk source assessment as well as the indices and formulas applied to measure the ecological loss and risk were established, and the method for comprehensively assessing the ecological risk of alien plant invasion was worked out. The result of ecological risk analysis to 9 representative invasive alien plants in China shows that the ecological risk of Erigeron annuus, Ageratum conyzoides, Alternanthera philoxeroides and Mikania midrantha is high (grade1-2), that of Oxalis corymbosa and Wedelia chinensis comes next (grade3), while Mirabilis jalapa, Pilea microphylla and Calendula officinalis of the last (grade 4). Risk strategies are put forward on this basis.

  9. Do invasive alien plants benefit more from global environmental change than native plants?

    Science.gov (United States)

    Liu, Yanjie; Oduor, Ayub M O; Zhang, Zhen; Manea, Anthony; Tooth, Ifeanna M; Leishman, Michelle R; Xu, Xingliang; van Kleunen, Mark

    2016-11-26

    Invasive alien plant species threaten native biodiversity, disrupt ecosystem functions and can cause large economic damage. Plant invasions have been predicted to further increase under ongoing global environmental change. Numerous case studies have compared the performance of invasive and native plant species in response to global environmental change components (i.e. changes in mean levels of precipitation, temperature, atmospheric CO2 concentration or nitrogen deposition). Individually, these studies usually involve low numbers of species and therefore the results cannot be generalized. Therefore, we performed a phylogenetically controlled meta-analysis to assess whether there is a general pattern of differences in invasive and native plant performance under each component of global environmental change. We compiled a database of studies that reported performance measures for 74 invasive alien plant species and 117 native plant species in response to one of the above-mentioned global environmental change components. We found that elevated temperature and CO2 enrichment increased the performance of invasive alien plants more strongly than was the case for native plants. Invasive alien plants tended to also have a slightly stronger positive response to increased N deposition and increased precipitation than native plants, but these differences were not significant (N deposition: P = 0.051; increased precipitation: P = 0.679). Invasive alien plants tended to have a slightly stronger negative response to decreased precipitation than native plants, although this difference was also not significant (P = 0.060). So while drought could potentially reduce plant invasion, increases in the four other components of global environmental change considered, particularly global warming and atmospheric CO2 enrichment, may further increase the spread of invasive plants in the future.

  10. Loss or gain? Invasive aliens and biodiversity in the Mediterranean Sea

    Energy Technology Data Exchange (ETDEWEB)

    Galil, B.S. [National Institute of Oceanography, Israel Oceanographic and Limnological Research, POB 8030, Haifa 31080 (Israel)]. E-mail: galil@post.tau.ac.il

    2007-07-01

    More than 500 alien species were listed from the Mediterranean Sea. Though no extinction of a native species is known, sudden decline in abundance, and even local extirpations, concurrent with proliferation of aliens, had been recorded. Examination of the profound ecological impacts of some of the most conspicuous invasive alien species underscores their role, among multiple anthropogenic stressors, in altering the infralittoral communities. Local population losses and niche contraction of native species may not induce immediate extirpation, but they augur reduction of genetic diversity, loss of functions, processes, and habitat structure, increase the risk of decline and extinction, and lead to biotic homogenization. The relevant environmental policy and management framework is discussed.

  11. Recovery of endemic dragonflies after removal of invasive alien trees.

    Science.gov (United States)

    Samways, Michael J; Sharratt, Norma J

    2010-02-01

    Because dragonflies are very sensitive to alien trees, we assessed their response to large-scale restoration of riparian corridors. We compared three types of disturbance regime--alien invaded, cleared of alien vegetation, and natural vegetation (control)--and recorded data on 22 environmental variables. The most significant variables in determining dragonfly assemblages were percentage of bank cover and tree canopy cover, which indicates the importance of vegetation architecture for these dragonflies. This finding suggests that it is important to restore appropriate marginal vegetation and sunlight conditions. Recovery of dragonfly assemblages after the clearing of alien trees was substantial. Species richness and abundance at restored sites matched those at control sites. Dragonfly assemblage patterns reflected vegetation succession. Thus, initially eurytopic, widespread species were the main beneficiaries of the removal of alien trees, and stenotopic, endemic species appeared after indigenous vegetation recovered over time. Important indicator species were the two national endemics (Allocnemis leucosticta and Pseudagrion furcigerum), which, along with vegetation type, can be used to monitor return of overall integrity of riparian ecology and to make management decisions. Endemic species as a whole responded positively to restoration, which suggests that indigenous vegetation recovery has major benefits for irreplaceable and widespread generalist species.

  12. Invasive species information networks: Collaboration at multiple scales for prevention, early detection, and rapid response to invasive alien species

    Science.gov (United States)

    Simpson, Annie; Jarnevich, Catherine S.; Madsen, John; Westbrooks, Randy G.; Fournier, Christine; Mehrhoff, Les; Browne, Michael; Graham, Jim; Sellers, Elizabeth A.

    2009-01-01

    Accurate analysis of present distributions and effective modeling of future distributions of invasive alien species (IAS) are both highly dependent on the availability and accessibility of occurrence data and natural history information about the species. Invasive alien species monitoring and detection networks (such as the Invasive Plant Atlas of New England and the Invasive Plant Atlas of the MidSouth) generate occurrence data at local and regional levels within the United States, which are shared through the US National Institute of Invasive Species Science. The Inter-American Biodiversity Information Network's Invasives Information Network (I3N), facilitates cooperation on sharing invasive species occurrence data throughout the Western Hemisphere. The I3N and other national and regional networks expose their data globally via the Global Invasive Species Information Network (GISIN). International and interdisciplinary cooperation on data sharing strengthens cooperation on strategies and responses to invasions. However, limitations to effective collaboration among invasive species networks leading to successful early detection and rapid response to invasive species include: lack of interoperability; data accessibility; funding; and technical expertise. This paper proposes various solutions to these obstacles at different geographic levels and briefly describes success stories from the invasive species information networks mentioned above. Using biological informatics to facilitate global information sharing is especially critical in invasive species science, as research has shown that one of the best indicators of the invasiveness of a species is whether it has been invasive elsewhere. Data must also be shared across disciplines because natural history information (e.g. diet, predators, habitat requirements, etc.) about a species in its native range is vital for effective prevention, detection, and rapid response to an invasion. Finally, it has been our

  13. A risk assessment system for alien plant bio-invasion in Xiamen of China

    Institute of Scientific and Technical Information of China (English)

    OU Jian; LU Changyi; DesmondK.O'TOOLE

    2008-01-01

    Bio-invasion has caused serious ecosystem damage and enormous economic losses in China, and it has been the greatest factor to island bio-diversity reduction. Xiamen, as an important seaport with a relatively high conservation value, is particularly vulnerable to bio-invasion for its typical island ecosystem as well as frequent human-made disturbance. As a result of field surveys, literature review, and consultation with experts, a list of 67 alien plants identified as major invaders (12 species) and emerging invaders (55 species) in Xiamen has been compiled. Based on the analysis of the current situation of bio-invasion in Xiamen, a risk assessment system for alien plant invasion has been designed using a ranking system and an analytic hierarchy process. The system consists of 17 secondary indices, grouped into 6 primary indices reflecting the different stages in the bio-invasion process: introduction, establishment, dispersion, current range, infestation, and artificial control. Biogeographical, ecological, and experience-linked aspects of the species as well as artificial disturbance were taken into account in the index selection and criterion development. The system was then validated (and worked well) using fifty well-known alien plant species as candidates. Appropriate recommendations are proposed to help local policy-makers prioritize their decisions on such alien plants.

  14. Minimizing Risks of Invasive Alien Plant Species in Tropical Production Forest Management

    Directory of Open Access Journals (Sweden)

    Michael Padmanaba

    2014-08-01

    Full Text Available Timber production is the most pervasive human impact on tropical forests, but studies of logging impacts have largely focused on timber species and vertebrates. This review focuses on the risk from invasive alien plant species, which has been frequently neglected in production forest management in the tropics. Our literature search resulted in 114 publications with relevant information, including books, book chapters, reports and papers. Examples of both invasions by aliens into tropical production forests and plantation forests as sources of invasions are presented. We discuss species traits and processes affecting spread and invasion, and silvicultural practices that favor invasions. We also highlight potential impacts of invasive plant species and discuss options for managing them in production forests. We suggest that future forestry practices need to reduce the risks of plant invasions by conducting surveillance for invasive species; minimizing canopy opening during harvesting; encouraging rapid canopy closure in plantations; minimizing the width of access roads; and ensuring that vehicles and other equipment are not transporting seeds of invasive species. Potential invasive species should not be planted within dispersal range of production forests. In invasive species management, forewarned is forearmed.

  15. Aliens in Transylvania: risk maps of invasive alien plant species in Central Romania

    Directory of Open Access Journals (Sweden)

    Heike Zimmermann

    2015-01-01

    Full Text Available Using the MAXENT algorithm, we developed risk maps for eight invasive plant species in southern Transylvania, Romania, a region undergoing drastic land-use changes. Our findings show that invasion risk increased with landscape heterogeneity. Roads and agricultural areas were most prone to invasion, whereas forests were least at risk.

  16. Public attitude in the city of Belgrade towards invasive alien plant species

    Directory of Open Access Journals (Sweden)

    Tomićević Jelena

    2012-01-01

    Full Text Available Biological invasions are seen as a major threat to biodiversity at a global level, while the number of new invasions is increasing at an alarming rate. Raising the awareness of the public, academic world and policy makers about the dangers caused by invasive species, is essential for the creation of the support needed to implement and coordinate the policies necessary to address this problem. The aim of this study is to determine the level of local public awareness of the existence of these plant species, examine the public attitude towards alien invasive plant species and willingness to get involved in the prevention of their spreading. The survey was conducted in four nurseries on the territory of the City of Belgrade and the investigation dealt only with alien invasive woody plant species. Thirty customers were questioned in each of the four nurseries. The results show that local public is uninformed on the issue of invasive plant species. It is necessary to constantly and intensively raise their awareness of this issue, as well as the awareness of harmful consequences that may occur due to the uncontrolled spreading of alien invasive species. This refers not only to the population that visits the nurseries and buys the plants there and to those employed in plant production and selling, but also to the whole local public and decision makers.

  17. Annotated list of marine alien species in the Mediterranean with records of the worst invasive species

    Directory of Open Access Journals (Sweden)

    A. ZENETOS

    2012-12-01

    Full Text Available This collaborative effort by many specialists across the Mediterranean presents an updated annotated list of alien marine species in the Mediterranean Sea. Alien species have been grouped into six broad categories namely established, casual, questionable, cryptogenic, excluded and invasive, and presented in lists of major ecofunctional/taxonomic groups. The establishment success within each group is provided while the questionable and excluded records are commented in brief. A total of 963 alien species have been reported from the Mediterranean until December 2005, 218 of which have been classified as excluded (23% leaving 745 of the recorded species as valid aliens. Of these 385 (52% are already well established, 262 (35% are casual records, while 98 species (13% remain “questionable” records. The species cited in this work belong mostly to zoobenthos and in particular to Mollusca and Crustacea, while Fish and Phytobenthos are the next two groups which prevail among alien biota in the Mediterranean. The available information depends greatly on the taxonomic group examined. Thus, besides the three groups explicitly addressed in the CIESM atlas series (Fish, Decapoda/Crustacea and Mollusca, which are however updated in the present work, Polychaeta, Phytobenthos, Phytoplankton and Zooplankton are also addressed in this study. Among other zoobenthic taxa sufficiently covered in this study are Echinodermata, Sipuncula, Bryozoa and Ascidiacea. On the contrary, taxa such as Foraminifera, Amphipoda and Isopoda, that are not well studied in the Mediterranean, are insufficiently covered. A gap of knowledge is also noticed in Parasites, which, although ubiquitous and pervasive in marine systems, have been relatively unexplored as to their role in marine invasions. Conclusively the lack of funding purely systematic studies in the region has led to underestimation of the number of aliens in the Mediterranean. Emphasis is put on those species that are

  18. Missing the Boat on Invasive Alien Species: A Review of Post-Secondary Curricula in Canada

    Science.gov (United States)

    Smith, Andrea L.; Bazely, Dawn R.; Yan, Norman D.

    2011-01-01

    Invasive alien species (IAS) cause major environmental and economic damage worldwide, and also threaten human food security and health. The impacts of IAS are expected to rise with continued globalization, land use modification, and climate change. Developing effective strategies to deal with IAS requires a collaborative, interdisciplinary…

  19. Status of biological control projects on terrestrial invasive alien weeds in California

    Science.gov (United States)

    In cooperation with foreign scientists, we are currently developing new classical biological control agents for five species of invasive alien terrestrial weeds. Cape-Ivy. A gall-forming fly, Parafreutreta regalis, and a stem-boring moth, Digitivalva delaireae, have been favorably reviewed by TAG...

  20. Experimental study to control the upstream migration of invasive alien fish species by submerged weir

    Science.gov (United States)

    Sakuma, Masami; Kunimatsu, Fumihiro; Tsuchiya, Taku; Kawamura, Makiko; Fujita, Hiroshi

    Largemouth bass and Bluegill, major invasive alien fish species in Japan, have been extending their habitat ranges over not only Lake Biwa and the lagoons but also surrounding waters connected to them through small rivers and canals. Their increasing number is bringing about the reduction in the number of native fish species. To prevent the spread of these alien species through small rivers and canals during breeding season of the native fish (crucian carp), this study experimentally examined the effect of a submerged weir on controlling upstream migration of the alien species and the native fish. As a result of the experiment, the ratio of the alien species migrating upstream decreased as the weir height rose, whereas the ratio did not show the same trend in the case of the native fish. The ratio of the alien species also decreased as the overflow velocity over the weir rose. On the other hand, the ratio of the native fish increased as the overflow velocity rose up to 1.0m/s and decreased thereafter. These results suggest that the submerged weir may control upstream migration of the alien species to surrounding waters through small rivers and canals without interfering with the reproductive migration of the native fish.

  1. Global threats from invasive alien species in the twenty-first century and national response capacities

    Science.gov (United States)

    Early, Regan; Bradley, Bethany A.; Dukes, Jeffrey S.; Lawler, Joshua J.; Olden, Julian D.; Blumenthal, Dana M.; Gonzalez, Patrick; Grosholz, Edwin D.; Ibañez, Ines; Miller, Luke P.; Sorte, Cascade J. B.; Tatem, Andrew J.

    2016-01-01

    Invasive alien species (IAS) threaten human livelihoods and biodiversity globally. Increasing globalization facilitates IAS arrival, and environmental changes, including climate change, facilitate IAS establishment. Here we provide the first global, spatial analysis of the terrestrial threat from IAS in light of twenty-first century globalization and environmental change, and evaluate national capacities to prevent and manage species invasions. We find that one-sixth of the global land surface is highly vulnerable to invasion, including substantial areas in developing economies and biodiversity hotspots. The dominant invasion vectors differ between high-income countries (imports, particularly of plants and pets) and low-income countries (air travel). Uniting data on the causes of introduction and establishment can improve early-warning and eradication schemes. Most countries have limited capacity to act against invasions. In particular, we reveal a clear need for proactive invasion strategies in areas with high poverty levels, high biodiversity and low historical levels of invasion. PMID:27549569

  2. Global threats from invasive alien species in the twenty-first century and national response capacities.

    Science.gov (United States)

    Early, Regan; Bradley, Bethany A; Dukes, Jeffrey S; Lawler, Joshua J; Olden, Julian D; Blumenthal, Dana M; Gonzalez, Patrick; Grosholz, Edwin D; Ibañez, Ines; Miller, Luke P; Sorte, Cascade J B; Tatem, Andrew J

    2016-08-23

    Invasive alien species (IAS) threaten human livelihoods and biodiversity globally. Increasing globalization facilitates IAS arrival, and environmental changes, including climate change, facilitate IAS establishment. Here we provide the first global, spatial analysis of the terrestrial threat from IAS in light of twenty-first century globalization and environmental change, and evaluate national capacities to prevent and manage species invasions. We find that one-sixth of the global land surface is highly vulnerable to invasion, including substantial areas in developing economies and biodiversity hotspots. The dominant invasion vectors differ between high-income countries (imports, particularly of plants and pets) and low-income countries (air travel). Uniting data on the causes of introduction and establishment can improve early-warning and eradication schemes. Most countries have limited capacity to act against invasions. In particular, we reveal a clear need for proactive invasion strategies in areas with high poverty levels, high biodiversity and low historical levels of invasion.

  3. Research Progress on Invasion Mechanism of Alien Invasive Species%外来物种入侵机制的研究进展

    Institute of Scientific and Technical Information of China (English)

    张巧; 郝建锋

    2011-01-01

    To make foundation for further study of alien plant invasion and fundamentally control alien plant invasion, in this paper the invasion status of alien plants in China was generalized, the process and mechanisms of biological invasion were analyzed and prevention and control measures were proposed which is of great significance to prevention of malignant alien invasive species invasion.%为了从根本上有效控制外来植物的入侵,为外来植物入侵的深入研究提供参考,综述了我国外来物种入侵现状,分析外来物种入侵过程及入侵机制,提出对入侵物种的预防和控制措施,对于防治恶性外来入侵物种有重要意义.

  4. Ornamental Plants as Invasive Aliens: Problems and Solutions in Kruger National Park, South Africa

    Science.gov (United States)

    Foxcroft, Llewellyn C.; Richardson, David M.; Wilson, John R. U.

    2008-01-01

    The most widespread invasive alien plant species in South Africa’s Kruger National Park (KNP) were either introduced unintentionally along rivers and roads, or intentionally for use as ornamentals. We examine the spatial distribution of ornamental alien plants in KNP, look at the link between human population size, history, and species richness, and show how the distribution of particular species reflects the likely history of ornamental plantings. Results are used to assess whether past management actions have been appropriately directed. Two hundred and fifty-eight alien species have been recorded in the 36 tourist camps and staff villages. The number of staff housed in villages explains much of the diversity of cultivated alien plant species. Older camps also tend to have more ornamental alien plant species. However, the lack of a strong link between camp age and number of cultivated species suggests that ornamental plants have been widely spread around the KNP by humans. We also show that increased camp activity (either size or age) has led to more ornamental species, while, with the notable exception of Skukuza, camp activity has had a much smaller effect on the number of noncultivated species. Noncultivated species tend to be naturally dispersed, as opposed to directly spread by humans between camps. Past management prioritized certain species on the basis of their potential to invade KNP and on the prevailing national legislation. These species were removed manually and follow-up control was carried out. Once the priority species were deemed to be under control, less invasive species were targeted. All alien species were removed from vacated houses, regardless of the potential invasiveness of the species.

  5. INVASIVESNET towards an International Association for Open Knowledge on Invasive Alien Species

    Science.gov (United States)

    Lucy, Frances E; Roy, Helen; Simpson, Annie; Carlton, James T.; Hanson, John Mark; Magellan, Kit; Campbell, Marnie L.; Costello, Mark J.; Pagad, Shyama; Hewitt, Chad L; McDonald, Justin; Cassey, Phillip; Thomaz, Sidinei M; Katsanevakis, Stelios; Zenetos, Argyro; Tricarico, Elena; Boggero, Angela; Groom, Quentin J; Adriaens, Tim; Vanderhoeven, Sonia; Torchin, Mark E.; Hufbauer, Ruth A.; Fuller, Pam; Carman, Mary R; Conn, David Bruce; Vitule, Jean R. S.; Canning-Clode, João; Galil, Bella S; Ojaveer, Henn; Bailey, Sarah A; Therriault, Thomas W; Claudi, Renata; Gazda, Anna; Dick, Jaimie T A; Caffrey, Joe; Witt, Arne; Kenis, Marc; Lehtiniemi, Maiju; Helmisaari, Harry; Panov, Vadim E

    2016-01-01

    In a world where invasive alien species (IAS) are recognised as one of the major threats to biodiversity, leading scientists from five continents have come together to propose the concept of developing an international association for open knowledge and open data on IAS—termed “INVASIVESNET”. This new association will facilitate greater understanding and improved management of invasive alien species (IAS) and biological invasions globally, by developing a sustainable network of networks for effective knowledge exchange. In addition to their inclusion in the CBD Strategic Plan for Biodiversity, the increasing ecological, social, cultural and economic impacts associated with IAS have driven the development of multiple legal instruments and policies. This increases the need for greater co-ordination, co-operation, and information exchange among scientists, management, the community of practice and the public.

  6. Clearing a Path Towards Effective Alien Invasive Control: the Legal Conundrum

    Directory of Open Access Journals (Sweden)

    AR Patterson

    2006-05-01

    Full Text Available Alien invasive plants pose significant ecological, social and economic challenges for South Africa. These species threaten South Africa’s rich biodiversity, deplete our scarce water resources, reduce the agricultural potential of land, cause soil erosion and intensify flooding and fires. According to recent estimations, over eight percent of land in South Africa has been invaded by these species and at current rates of expansion their impact could double in the next fifteen years. In an attempt to curb the impending crises, the South African government has promulgated eleven national and various provincial laws which contain mechanisms for regulating the different threats posed by alien invasive plants. Certain of these laws are framework in nature while the majority are sectoral and aimed at regulating these species for one of the following four main purposes: biodiversity conservation; water conservation; agricultural management; and fire risk management. The responsibility for administering these laws spans four national departments, nine provincial environmental authorities, provincial conservation authorities, numerous local and statutory authorities. This fragmented regime, coupled with the adoption of a command and control approach to regulation, has proven inept in effectively regulating the spread of alien invasive plants in South Africa. This reality led the previous Minister of Environmental Affairs and Tourism, Mr Valli Moosa, to call for the development of a “coherent legislative framework … streamlined along the lines of the principles endorsed by the Convention on Biological Diversity”. This article critically analyses the government’s attempts to develop such a “coherent legislative framework” to regulate alien invasive plants in light of recent legislative reform. It is divided into two parts. Part one critically considers South Africa’s current laws of relevance to alien invasive plants with specific emphasis on

  7. Invasive Alien Species of Terrestrial Vegetation of North-Eastern Uttar Pradesh

    Directory of Open Access Journals (Sweden)

    Sumit Srivastava

    2014-01-01

    Full Text Available The vegetational landscape of north-eastern Terai region at the foot hills of Central Himalayas is a mosaic of grassland, old-field, wasteland, and forest ecosystems. Like many other parts of the country, this region is also infested with alien intruders which not only interfere with the growth and production of food crops but also exercise adverse effects on the biodiversity of native species. The present study attempts to catalogue the invasive alien species of the terrestrial vegetation of north-eastern Uttar Pradesh especially with reference to their habit, taxonomic position, and nativity. A total of 1135 plant species within 580 genera under 119 families are so far known to occur in the region. Of these, only 149 species within 100 genera under 41 families have been found to be invasive aliens as evident from their center of origin, past history, nature of aggregation, and invasion observed under field conditions. About 80% of these invaders have been introduced from neotropics. Out of 173 invasive plants across India, this region shares 149 species, out of which 66% of species have come from Tropical America, 14% from African continent, and the rest from other countries. A better planning in the form of early identification and reporting of infestation and spread of noxious weeds is needed for their control.

  8. Fire-driven alien invasion in a fire-adapted ecosystem

    Science.gov (United States)

    Keeley, Jon E.; Brennan, Teresa J.

    2012-01-01

    Disturbance plays a key role in many alien plant invasions. However, often the main driver of invasion is not disturbance per se but alterations in the disturbance regime. In some fire-adapted shrublands, the community is highly resilient to infrequent, high-intensity fires, but changes in the fire regime that result in shorter fire intervals may make these communities more susceptible to alien plant invasions. This study examines several wildfire events that resulted in short fire intervals in California chaparral shrublands. In one study, we compared postfire recovery patterns in sites with different prefire stand ages (3 and 24 years), and in another study we compared sites that had burned once in four years with sites that had burned twice in this period. The population size of the dominant native shrub Adenostoma fasciculatum was drastically reduced following fire in the 3-year sites relative to the 24-year sites. The 3-year sites had much greater alien plant cover and significantly lower plant diversity than the 24-year sites. In a separate study, repeat fires four years apart on the same sites showed that annual species increased significantly after the second fire, and alien annuals far outnumbered native annuals. Aliens included both annual grasses and annual forbs and were negatively correlated with woody plant cover. Native woody species regenerated well after the first fire but declined after the second fire, and one obligate seeding shrub was extirpated from two sites by the repeat fires. It is concluded that some fire-adapted shrublands are vulnerable to changes in fire regime, and this can lead to a loss of native diversity and put the community on a trajectory towards type conversion from a woody to an herbaceous system. Such changes result in alterations in the proportion of natives to non-natives, changes in functional types from deeply rooted shrubs to shallow rooted grasses and forbs, increased fire frequency due to the increase in fine fuels

  9. Insect Eradication and Containment of Invasive Alien Species

    Science.gov (United States)

    Insect eradication programs are nearly always targeted at recently arrived invasive species with significant pest potential. They attempt to contain a pest to a defined area and then completely eliminate the pest from that area. From a Federal regulatory standpoint, eradication programs are undert...

  10. Checklist of invasive alien species in CSIR-NBRI Botanic Garden, Lucknow, India

    Directory of Open Access Journals (Sweden)

    Shilpi Singh

    2015-08-01

    Full Text Available The invasive alien species of CSIR-NBRI Botanic Garden are enumerated and their impact on the surrounding ecosystem are discussed. This study deals with the information on habit, nativity and family of plant species occurring in the area of study. A total of 103 invasive alien species under 86 genera and 36 families were recorded. Among these, the eudicotyledons represent 85 species, 69 genera and 32 families; monocotyledons represent 18 species, 17 genera and 4 families. In terms of nativity, species from Tropical America are the most dominant group with 34 species. In addition, based on life forms, herbs are dominant (88 species, followed by shrubs (8 species, climbers (4 species and trees (3 species.

  11. The application of the European strategy on invasive alien species: an example with introduced squirrels

    OpenAIRE

    Sandro Bertolino; Piero Genovesi

    2005-01-01

    Abstract We assessed the cases of squirrel species already introduced into Italy inside the framework proposed by the European strategy on invasive alien species. We collected information on 9 introductions that originated 8 populations: 3 of grey squirrels (Sciurus carolinensis), 2 of Finlayson's squirrels (Callosciurus finlaysonii), and 3 of Siberian chip-munks (Eutamias sibiricus). Food opportunism...

  12. [Fast catalogue of alien invasive weeds by Vis/NIR spectroscopy].

    Science.gov (United States)

    Yu, Jia-Jia; Zou, Wei; He, Yong; Xu, Zheng-Hao

    2009-11-01

    The feasibility of visible and short-wave near-infrared spectroscopy (VIS/WNIR) techniques as means for the nondestructive and fast detection of alien invasive weeds was evaluated. Selected sensitive bands were found validated. In the present study, 3 kinds of alien invasive weeds, Veronica persica, Veronica polita, and Veronica arvensis Linn, and one kind of local weed, Lamiaceae amplexicaule Linn, were employed. The results showed that visible and NIR (Vis/NIR) technology could be introduced in classification of the alien invasive weeds or local weed with the similar outline. Thirty x 4 weeds samples were randomly selected for the calibration set, while the remaining 20 x 4 samples for the prediction set. Smoothing methods of moving average and standard normal variate (SNV) were used to pretreat spectra data. Based on principal components analysis, soft independent models of class analogy (SIMCA) were applied to make the model. Four frontal principal components of each catalogues were applied as the input of SIMCA, and with a significance level of 0.05, recognition ratio of 78.75% was obtained. The average prediction result is 90% except for Veronica polita. According to the modeling power of each spectra data in SIMCA, some possible sensitive bands, 496-521, 589-626 and 789-926 nm, were founded. By using these possible sensitive bands as the inputs of least squares support vector machine (LS-SVM), and setting the result of LS-SVM as the object function value of genetic algorithm (GA), mutational rate, crossover rate and population size were set up as 0.9, 0.5 and 50 respectively. Finally recognition ratio of 95.63% was obtained. The prediction results of 95.63% indicated that the selected wavelengths reflected the main characteristics of the four weeds, which proposed a new way to accelerate the research on cataloguing alien invasive weeds.

  13. Sentinel trees as a tool to forecast invasions of alien plant pathogens.

    Directory of Open Access Journals (Sweden)

    AnnaMaria Vettraino

    Full Text Available Recent disease outbreaks caused by alien invasive pathogens into European forests posed a serious threat to forest sustainability with relevant environmental and economic effects. Many of the alien tree pathogens recently introduced into Europe were not previously included on any quarantine lists, thus they were not subject to phytosanitary inspections. The identification and description of alien fungi potentially pathogenic to native European flora before their introduction in Europe, is a paramount need in order to limit the risk of invasion and the impact to forest ecosystems. To determine the potential invasive fungi, a sentinel trees plot was established in Fuyang, China, using healthy seedlings of European tree species including Quercus petreae, Q. suber, and Q. ilex. The fungal assemblage associated with symptomatic specimens was studied using the tag-encoded 454 pyrosequencing of the nuclear ribosomal internal transcribed spacer-1 (ITS 1. Taxa with probable Asiatic origin were identified and included plant pathogenic genera. These results indicate that sentinel plants may be a strategic tool to improve the prevention of bioinvasions.

  14. The quest gone astray: tracing horror in alien invasion television series of the new millenium

    OpenAIRE

    Ay, Tuba

    2008-01-01

    91 pages The starting years of the new millennium, explicitly the year 2005, witnessed an attempt to bring the science fiction genre to the mainstream like the attempt in the 1950s, however, this time not through the medium of film but through television. Conversely, the outcome is not the same for the television series that have alien invasion narratives, if compared to the B-movies of the 1950s that had similar narratives. Mostly concentrated upon the texts of the series Invasion and Thr...

  15. EventSlider User Manual

    Science.gov (United States)

    2016-09-01

    FrameworkElement parent class), which allows for efficient batch setting of these main properties without changing the display until the initialization is...a single click, or a tap, near or on an event line. 4. Library and Namespace The EventSlider control has been compiled into the following dynamic...namespace:WPFControls.EventSlider;assembly=WPFControls.EventSlider" Only a single class is exposed in this namespace, the EventSlider class. All methods, properties, and

  16. Interspecific Differences in Diet between Introduced Red-eared Sliders and Native Turtles in China

    Institute of Scientific and Technical Information of China (English)

    Jian WANG; Haitao SHI; Shijia HU; Kai MA; Chuang LI

    2013-01-01

    Although the alien Red-eared slider (Trachemys scripta elegans) is generally argued as an invasive species that competes with native turtles, the ifeld evidence on its diet is controversial. Field studies conducted at the Gutian Nature Reserve of Guangdong and along the Wanquan River in Hainan, China show that T. s. elegans is an opportunitic omnivore, consuming a wide variety of food items. Consumption varies throughout its range;more plant material is consumed in Guangdong, compared to a more carnivorous diet in Hainan;and juveniles are also found to have a more carnivorous diet than adults. This implies a high adaptability to new environment. Sympatric native Mauremys sinensis shows a more herbivorous diet and a narrower niche breadth (0.0260) in Hainan, plus a low niche overlap (0.3048) with T. s. elegans, providing a potential empty niche for the invasive T. s. elegans. Red-eared slider is also known to consume large quantities of native prey species to disrupt the ecological balance. It is imperative to understand the invasive nature of this species and the mechanisms by which it affects native ecology.

  17. New alien barnacles in the Azores and some remarks on the invasive potential of Balanidae

    Science.gov (United States)

    Torres, Paulo; Costa, Ana Cristina; Dionísio, Maria Ana

    2012-12-01

    Global homogenization of biota is underway through worldwide introduction and establishment of non-indigenous (exotic) species. Organisms fouling ship hulls are continually in transit and can affect communities through biodiversity loss and serious damage to economy and public health. In the Azores, for the first time, underwater alien species prospection was conducted in marinas and recreational harbours, at São Miguel Island. Populations of three locally previously unknown barnacle species were found: Amphibalanus amphitrite, Amphibalanus eburneus and Perforatus perforatus. These species account for the more than 50% of alien barnacles worldwide that belong to Balanidae family. Hence, some considerations about morphology and life cycle of this family are advanced, discussed and related to their invasive potential.

  18. Developing thresholds of potential concern for invasive alien species: Hypotheses and concepts

    Directory of Open Access Journals (Sweden)

    Llewellyn C. Foxcroft

    2009-01-01

    Full Text Available The Kruger National Park (KNP has developed and refined a system of management called ‘strategic adaptive management’ (SAM, which rests on the concept of ‘threshold of potential concern’ (TPC. TPCs represent end-points in a continuum of change. When thresholds are reached – at which point concerns of negative impacts on biodiversity are raised – management options are explicitly considered and implemented. This paper describes the TPCs developed for monitoring and managing invasive alien species (IAS. More importantly, however, it describes the conceptual understanding, principles and hypotheses adopted as the foundations for setting these TPCs. In accordance with adaptive management practices, the TPCs will be revised as the ecological and conceptual understanding of invasions grows and information is gained through research in the KNP and elsewhere.Conservation implication: In accepting that species and systems are variable, and that flux is inevitable and desirable, these TPCs developed for invasive alien species specifi cally, provide end points against which monitoring can be assessed. Once a threshold is reached, the cause of the threshold being exceeded is examined and management interventions recommended.

  19. Release from belowground enemies and shifts in root traits as interrelated drivers of alien plant invasion success: a hypothesis.

    Science.gov (United States)

    Dawson, Wayne

    2015-10-01

    Our understanding of the interrelated mechanisms driving plant invasions, such as the interplay between enemy release and resource-acquisition traits, is biased by an aboveground perspective. To address this bias, I hypothesize that plant release from belowground enemies (especially fungal pathogens) will give invasive plant species a fitness advantage in the alien range, via shifts in root traits (e.g., increased specific root length and branching intensity) that increase resource uptake and competitive ability compared to native species in the alien range, and compared to plants of the invader in its native range. Such root-trait changes could be ecological or evolutionary in nature. I explain how shifts in root traits could occur as a consequence of enemy release and contribute to invasion success of alien plants, and how they could be interrelated with other potential belowground drivers of invasion success (allelopathy, mutualist enhancement). Finally, I outline the approaches that could be taken to test whether belowground enemy release results in increased competitive ability and nutrient uptake by invasive alien plants, via changes in root traits in the alien range.

  20. Stakeholder Perceptions of an Ecosystem Services Approach to Clearing Invasive Alien Plants on Private Land

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    Lauren S. Urgenson

    2013-03-01

    Full Text Available Incentivizing private landowners and other stakeholders is central to the effective conservation of ecosystem services in working landscapes. To better understand how to design effective incentives, the perceptions of landowners and other stakeholders are explored regarding a proposed approach to clearing invasive alien plants on private land in the Western Cape Province, South Africa. The public funded national program, Working for Water, conserves ecosystem services while employing and training people from marginalized sectors of society to clear these plants. Private landowner involvement is a key conservation challenge, because without adequate landowner involvement, invasive alien plants persist on the landscape and continuously reinvade cleared areas. We collected interview data from private landowners in three study sites, and web-survey data from conservation professionals and Working for Water managers, in order to compare stakeholder perceptions of (1 government and landowners' responsibilities for clearing invasive alien plants; (2 existing and proposed policy tools; and (3 the extent to which stakeholders consider the proposed financial incentive to be sufficient. There was significant consensus among stakeholders concerning their preference for shared landowner and government responsibility and for a policy mix that combines incentives with disincentives. Landowners from the three study sites differed in the level of responsibility they were willing to assume. Stakeholders also diverged in terms of their perceptions of the proposed financial incentives. Furthermore, the perspectives of landowners were strongly associated with ecological and social features of the landscapes in which they are located. Understanding stakeholders' points of view within their differing contexts is shown to be a valuable means of gaining insight into the opportunities and constraints that face ecosystem service conservation in working landscapes.

  1. Invasive alien woody plants of the southern and southwestern Cape region, South Africa

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    L. Henderson

    1998-12-01

    Full Text Available The frequency and abundance of invasive alien plants were recorded along roadsides and at watercourse crossings in 82.9% (145/175 of the quarter degree squares in the study area (3I-35°S, 17-25°E and covering ± 90 000 km:. The sur­vey yielded 102 species of which the most prominent (in order of prominence in roadside and veld (natural and modified habitats were: Acacia cyclops, A. saligna and A. mearnsii The most prominent species (in order of prominence in stream- bank habitats were: A. mearnsii, A. saligna and Populus x canescens.

  2. Climatic niche divergence and habitat suitability of eight alien invasive weeds in China under climate change.

    Science.gov (United States)

    Wan, Ji-Zhong; Wang, Chun-Jing; Tan, Jing-Fang; Yu, Fei-Hai

    2017-03-01

    Testing climatic niche divergence and modeling habitat suitability under conditions of climate change are important for developing strategies to limit the introduction and expansion of alien invasive weeds (AIWs) and providing important ecological and evolutionary insights. We assessed climatic niches in both native and invasive ranges as well as habitat suitability under climate change for eight representative Chinese AIWs from the American continent. We used climatic variables associated with occurrence records and developed ecological niche models with Maxent. Interestingly, the climatic niches of all eight AIWs diverged significantly between the native and invasive ranges (the American continent and China). Furthermore, the AIWs showed larger climatic niche breadths in the invasive ranges than in the native ranges. Our results suggest that climatic niche shifts between native and invasive ranges occurred. Thus, the occurrence records of both native and invasive regions must be considered when modeling and predicting the spatial distributions of AIWs under current and future climate scenarios. Owing to high habitat suitability, AIWs were more likely to expand into regions of low latitude, and future climate change was predicted to result in a shift in the AIWs in Qinghai and Tibet (regions of higher altitude) as well as Heilongjiang, Jilin, Liaoning, Inner Mongolia, and Gansu (regions of higher latitude). Our results suggest that we need measures to prevent and control AIW expansion at the country-wide level.

  3. Species pools, community completeness and invasion: disentangling diversity effects on the establishment of native and alien species.

    Science.gov (United States)

    Bennett, Jonathan A; Riibak, Kersti; Kook, Ene; Reier, Ülle; Tamme, Riin; Guillermo Bueno, C; Pärtel, Meelis

    2016-12-01

    Invasion should decline with species richness, yet the relationship is inconsistent. Species richness, however, is a product of species pool size and biotic filtering. Invasion may increase with richness if large species pools represent weaker environmental filters. Measuring species pool size and the proportion realised locally (completeness) may clarify diversity-invasion relationships by separating environmental and biotic effects, especially if species' life-history stage and origin are accounted for. To test these relationships, we added seeds and transplants of 15 native and alien species into 29 grasslands. Species pool size and completeness explained more variation in invasion than richness alone. Although results varied between native and alien species, seed establishment and biotic resistance to transplants increased with species pool size, whereas transplant growth and biotic resistance to seeds increased with completeness. Consequently, species pools and completeness represent multiple independent processes affecting invasion; accounting for these processes improves our understanding of invasion.

  4. Alien invasions and the game of hide and seek in Patagonia.

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    Martin Lindegren

    Full Text Available The introduction, establishment and spread of alien species is a major threat to biodiversity and the provision of ecosystem services for human wellbeing. In order to reduce further loss of biodiversity and maintain productive and sustainable ecosystems, understanding the ecological mechanisms underlying species invasions and avoiding potentially harmful effects on native communities is urgently needed, but largely lacking. We here demonstrate, by means of hydroacoustics and advanced spatial modelling, how native fish species as a result of previous exposure to native predators may successfully respond to invasive novel predators through a complicated game of hide and seek, minimizing spatio-temporal overlap with predators, and potentially facilitating coexistence between native prey species (Galaxiids and introduced novel predators (Salmonids in a deep Andean lake, Patagonia.

  5. The Impact of the Invasive Alien Plant, Impatiens glandulifera, on Pollen Transfer Networks

    Science.gov (United States)

    Emer, Carine; Vaughan, Ian P.; Hiscock, Simon; Memmott, Jane

    2015-01-01

    Biological invasions are a threat to the maintenance of ecological processes, including pollination. Plant-flower visitor networks are traditionally used as a surrogated for pollination at the community level, despite they do not represent the pollination process, which takes place at the stigma of plants where pollen grains are deposited. Here we investigated whether the invasion of the alien plant Impatiens glandulifera (Balsaminaceae) affects pollen transfer at the community level. We asked whether more alien pollen is deposited on the stigmas of plants on invaded sites, whether deposition is affected by stigma type (dry, semidry and wet) and whether the invasion of I. glandulifera changes the structure of the resulting pollen transfer networks. We sampled stigmas of plants on 10 sites invaded by I. glandulifera (hereafter, balsam) and 10 non-invaded control sites. All 20 networks had interactions with balsam pollen, although significantly more balsam pollen was found on plants with dry stigmas in invaded areas. Balsam pollen deposition was restricted to a small subset of plant species, which is surprising because pollinators are known to carry high loads of balsam pollen. Balsam invasion did not affect the loading of native pollen, nor did it affect pollen transfer network properties; networks were modular and poorly nested, both of which are likely to be related to the specificity of pollen transfer interactions. Our results indicate that pollination networks become more specialized when moving from the flower visitation to the level of pollen transfer networks. Therefore, caution is needed when inferring pollination from patterns of insect visitation or insect pollen loads as the relationship between these and pollen deposition is not straightforward. PMID:26633170

  6. The Impact of the Invasive Alien Plant, Impatiens glandulifera, on Pollen Transfer Networks.

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    Carine Emer

    Full Text Available Biological invasions are a threat to the maintenance of ecological processes, including pollination. Plant-flower visitor networks are traditionally used as a surrogated for pollination at the community level, despite they do not represent the pollination process, which takes place at the stigma of plants where pollen grains are deposited. Here we investigated whether the invasion of the alien plant Impatiens glandulifera (Balsaminaceae affects pollen transfer at the community level. We asked whether more alien pollen is deposited on the stigmas of plants on invaded sites, whether deposition is affected by stigma type (dry, semidry and wet and whether the invasion of I. glandulifera changes the structure of the resulting pollen transfer networks. We sampled stigmas of plants on 10 sites invaded by I. glandulifera (hereafter, balsam and 10 non-invaded control sites. All 20 networks had interactions with balsam pollen, although significantly more balsam pollen was found on plants with dry stigmas in invaded areas. Balsam pollen deposition was restricted to a small subset of plant species, which is surprising because pollinators are known to carry high loads of balsam pollen. Balsam invasion did not affect the loading of native pollen, nor did it affect pollen transfer network properties; networks were modular and poorly nested, both of which are likely to be related to the specificity of pollen transfer interactions. Our results indicate that pollination networks become more specialized when moving from the flower visitation to the level of pollen transfer networks. Therefore, caution is needed when inferring pollination from patterns of insect visitation or insect pollen loads as the relationship between these and pollen deposition is not straightforward.

  7. Preference and Prey Switching in a Generalist Predator Attacking Local and Invasive Alien Pests

    Science.gov (United States)

    Jaworski, Coline C.; Bompard, Anaïs; Genies, Laure; Amiens-Desneux, Edwige; Desneux, Nicolas

    2013-01-01

    Invasive pest species may strongly affect biotic interactions in agro-ecosystems. The ability of generalist predators to prey on new invasive pests may result in drastic changes in the population dynamics of local pest species owing to predator-mediated indirect interactions among prey. On a short time scale, the nature and strength of such indirect interactions depend largely on preferences between prey and on predator behavior patterns. Under laboratory conditions we evaluated the prey preference of the generalist predator Macrolophus pygmaeus Rambur (Heteroptera: Miridae) when it encounters simultaneously the local tomato pest Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) and the invasive alien pest Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae). We tested various ratios of local vs. alien prey numbers, measuring switching by the predator from one prey to the other, and assessing what conditions (e.g. prey species abundance and prey development stage) may favor such prey switching. The total predation activity of M. pygmaeus was affected by the presence of T. absoluta in the prey complex with an opposite effect when comparing adult and juvenile predators. The predator showed similar preference toward T. absoluta eggs and B. tabaci nymphs, but T. absoluta larvae were clearly less attacked. However, prey preference strongly depended on prey relative abundance with a disproportionately high predation on the most abundant prey and disproportionately low predation on the rarest prey. Together with the findings of a recent companion study (Bompard et al. 2013, Population Ecology), the insight obtained on M. pygmaeus prey switching may be useful for Integrated Pest Management in tomato crops, notably for optimal simultaneous management of B. tabaci and T. absoluta, which very frequently co-occur on tomato. PMID:24312646

  8. PHYTOSOCIOLOGY OF INVASIVE ALIEN THEROPHYTIC FLORA OF PEDDAGATTU, THE PROPOSED SITE FOR URANIUM MINING IN NALGONDA DISTRICT, TELANGANA, INDIA

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    A. BALEESHWAR REDDY1*, V. HANUMANTHA RAO AND V. VASUDEVA RAO2

    2014-10-01

    The present investigation reflects the findings of invasive alien species and phytosociological attributes at Peddagattu (Lambapur, Nalgonda district, Telangana, India. Phytosociology studies on Invasive alien species were collected during 2010-2012. Of 30 species of taxa are belonging to 29 genera and 17 families. Compositae is the most dominant family representing   with 6 species (20% followed by Malvaceae 4 species (13%, Solanaceae 3 species (10%, Amaranthaceae  and Leguminaceae with 2 species (7% each. About 60% of these alien species were introduced from Tropical America followed by Tropical Africa (13%, and Trop. C. America (7%. Among the species, Tridax procumbens shows the highest IVI value (12.94 and followed by Cleome viscose (7.12, Waltheria indica (6.13 and Parthenium hysterophorus (5.57 and Typha angustata (5.22.

  9. Evidence, Perceptions, and Trade-offs Associated with Invasive Alien Plant Control in the Table Mountain National Park, South Africa

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    Brian W. van Wilgen

    2012-06-01

    Full Text Available The Table Mountain National Park is a 265 km2 protected area embedded within a city of 3.5 million people. The park contains an extremely diverse flora with many endemic species, and has been granted World Heritage Site status in recognition of this unique biodiversity. Invasive alien plants are arguably the most significant threat to the conservation of this biodiversity, and the past decade has seen the implementation of aggressive programs aimed at the removal of invasions by these plants. These invasive alien plants include several species of trees, notably pines (Pinus species and eucalypts (Eucalyptus species, which historically have been grown in plantations, and which are utilized for recreation by the city's residents. In addition, many citizens regard the trees as attractive and ecologically beneficial, and for these reasons the alien plant control programs have been controversial. I briefly outline the legal obligations to deal with invasive alien plants, the history of control operations and the scientific rationale for their implementation, and the concerns that have been raised about the operations. Evidence in support of control includes the aggressive invasive nature of many species, and the fact that they displace native biodiversity (often irreversibly and have negative impacts on hydrology, fire intensity, and soil stability. Those against control cite aesthetic concerns, the value of pine plantations for recreation, the (perceived unattractive nature of the treeless natural vegetation, and the (incorrect belief that trees bring additional rainfall. The debate has been conducted through the press, and examples of perceptions and official responses are given. Despite opposition, the policy promoting alien plant removal has remained in place, and considerable progress has been made towards clearing pine plantations and invasive populations. This conservation success story owes much to political support, arising largely from job

  10. EU Regulation 1143/2014 and the Bern Convention : Allied forces in the war on invasive alien species

    NARCIS (Netherlands)

    Trouwborst, Arie

    2015-01-01

    This article identifies and analyzes current and potential synergies between the new EU Regulation 1143/2014 on the prevention and management of the introduction and spread of invasive alien species on the one hand, and the Bern Convention on the Conservation of European Wildlife and Natural Habitat

  11. Resilience to disturbance and resistance to alien grass invasions in the cold desert of western North America

    Science.gov (United States)

    Alien grass invasions are resulting in ecosystem-level transformations of entire landscapes in arid and semi-arid ecosystems. The cold desert of western US is undergoing such a transformation, and is considered one of the most imperiled large ecosystems in the US. To address the rapid and complex ch...

  12. A biome-scale assessment of the impact of invasive alien plants on ecosystem services in South Africa.

    Science.gov (United States)

    van Wilgen, B W; Reyers, B; Le Maitre, D C; Richardson, D M; Schonegevel, L

    2008-12-01

    This paper reports an assessment of the current and potential impacts of invasive alien plants on selected ecosystem services in South Africa. We used data on the current and potential future distribution of 56 invasive alien plant species to estimate their impact on four services (surface water runoff, groundwater recharge, livestock production and biodiversity) in five terrestrial biomes. The estimated reductions in surface water runoff as a result of current invasions were >3000 million m(3) (about 7% of the national total), most of which is from the fynbos (shrubland) and grassland biomes; the potential reductions would be more than eight times greater if invasive alien plants were to occupy the full extent of their potential range. Impacts on groundwater recharge would be less severe, potentially amounting to approximately 1.5% of the estimated maximum reductions in surface water runoff. Reductions in grazing capacity as a result of current levels of invasion amounted to just over 1% of the potential number of livestock that could be supported. However, future impacts could increase to 71%. A 'biodiversity intactness index' (the remaining proportion of pre-modern populations) ranged from 89% to 71% for the five biomes. With the exception of the fynbos biome, current invasions have almost no impact on biodiversity intactness. Under future levels of invasion, however, these intactness values decrease to around 30% for the savanna, fynbos and grassland biomes, but to even lower values (13% and 4%) for the two karoo biomes. Thus, while the current impacts of invasive alien plants are relatively low (with the exception of those on surface water runoff), the future impacts could be very high. While the errors in these estimates are likely to be substantial, the predicted impacts are sufficiently large to suggest that there is serious cause for concern.

  13. Ecdysteroids in the larvae of Opogona sacchari (Bojer), a invasive alien pest

    Institute of Scientific and Technical Information of China (English)

    WANG FangHai; ZHANG GuRen; WEN RuiZhen; HE GuoFeng

    2007-01-01

    In order to understand the composition and quantitative variation of ecdysteriods in the larvae of Opogona sacchari (Bojer), a invasive alien pest, we analyzed the larval ecdysteroid composition and titers in this pest. The main component of ecdysteriods in the larvae of O. Sacchari is 20-hydroxyecdysone, and also there is a little 26-hydroxyecdysone. The titer of ecdysteriods in the larvae from the 1st instar to the 7th instar was gotten higher gradually compared on ng ecdysteroid/larva, but no regularity could be found about the titer if compared on ng ecdysteroid/g avoirdupois. There was only one peak of ecdysteroids (0.5475 ng/larva) showed at day 2 during the developmental time of the 6th instar larvae. However, there were two peaks appearing during the developmental time of the 7th instar larvae , one peak (0.29415 ng/larva) at day 3, another (0.214 ng/larva) at day 5.

  14. Alien plants introduced by different pathways differ in invasion success: unintentional introductions as a threat to natural areas.

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    Petr Pyšek

    Full Text Available BACKGROUND: Understanding the dimensions of pathways of introduction of alien plants is important for regulating species invasions, but how particular pathways differ in terms of post-invasion success of species they deliver has never been rigorously tested. We asked whether invasion status, distribution and habitat range of 1,007 alien plant species introduced after 1500 A.D. to the Czech Republic differ among four basic pathways of introduction recognized for plants. PRINCIPAL FINDINGS: Pathways introducing alien species deliberately as commodities (direct release into the wild; escape from cultivation result in easier naturalization and invasion than pathways of unintentional introduction (contaminant of a commodity; stowaway arriving without association with it. The proportion of naturalized and invasive species among all introductions delivered by a particular pathway decreases with a decreasing level of direct assistance from humans associated with that pathway, from release and escape to contaminant and stowaway. However, those species that are introduced via unintentional pathways and become invasive are as widely distributed as deliberately introduced species, and those introduced as contaminants invade an even wider range of seminatural habitats. CONCLUSIONS: Pathways associated with deliberate species introductions with commodities and pathways whereby species are unintentionally introduced are contrasting modes of introductions in terms of invasion success. However, various measures of the outcome of the invasion process, in terms of species' invasion success, need to be considered to accurately evaluate the role of and threat imposed by individual pathways. By employing various measures we show that invasions by unintentionally introduced plant species need to be considered by management as seriously as those introduced by horticulture, because they invade a wide range of seminatural habitats, hence representing even a greater

  15. Effects of invasive alien kahili ginger (Hedychium gardnerianum) on native plant species regeneration in a Hawaiian rainforest

    Science.gov (United States)

    Minden, V.; Jacobi, J.D.; Porembski, S.; Boehmer, H.J.

    2010-01-01

    Questions: Does the invasive alien Hedychium gardnerianum (1) replace native understory species, (2) suppress natural regeneration of native plant species, (3) increase the invasiveness of other non-native plants and (4) are native forests are able to recover after removal of H. gardnerianum. Location: A mature rainforest in Hawai'i Volcanoes National Park on the island of Hawai'i (about 1200 m. a.s.l.; precipitation approximately 2770mm yr-1). Study sites included natural plots without effects of alien plants, ginger plots with a H. gardnerianum-domimted herb layer and cleared plots treated with herbicide to remove alien plants. Methods: Counting mature trees, saplings and seedlings of native and alien plant species. Using nonparametric H-tests to compare impact of H. gardnerianum on the structure of different sites. Results: Results confirmed the hypothesis that H. gardnerianum has negative effects on natural forest dynamics. Lower numbers of native tree seedlings and saplings were found on ginger-dominated plots. Furthermore, H. gardnerianum did not show negative effects on the invasive alien tree species Psidium cattleianum. Conclusions: This study reveals that where dominance of H. gardnerianum persists, regeneration of the forest by native species will be inhibited. Furthermore, these areas might experience invasion by P. cattleianum, resulting in displacement of native canopy species in the future, leading to a change in forest structure and loss of other species dependent on natural rainforest, such as endemic birds. However, if H. gardnerianum is removed the native Hawaiian forest is likely to regenerate and regain its natural structure. ?? 2009 International Association for Vegetation Science.

  16. Chemical cues released by an alien invasive aquatic gastropod drive its invasion success.

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    Jacqueline L Raw

    Full Text Available BACKGROUND: Chemical cues provide aquatic organisms with sensory information that guides behavioural responses and thus interactions among themselves, each other and the environment. Chemical cues are considered important for predator avoidance, foraging, larval settlement and broadcast spawning in aquatic environments. However, the significance of their role as drivers of direct interactions between heterospecifics has been largely overlooked. METHODOLOGY/PRINCIPAL FINDINGS: A video camera and a demarcated arena were used in situ to record behavioural responses of three native gastropod species, Assiminea cf. capensis, Melanoides tuberculata and Coriandria durbanensis, exposed to treatments representing chemical cues released by a non-native invasive gastropod, Tarebia granifera. The responses were measured quantitatively as displacement and orientation of movement at locations in St Lucia Estuary, within the iSimangaliso Wetland Park, a UNESCO World Heritage Site on the east coast of South Africa. All native gastropods exhibited a negative taxis response to chemical cues released by T. granifera, while T. granifera individuals responded randomly to conspecifics. Displacement was measured relative to the source of the extract, the number of steps taken were determined with path analysis and orientation was determined from the mean (±95% CIs turning angles, with significant negative turning angles representing negative taxis. Responses to treatments corresponding to the environment and conspecifics were random and undirected, indicating kinesis. CONCLUSION/SIGNIFICANCE: This study presents evidence for interactions driven by chemical cues between a non-native invasive gastropod and several gastropods native to South Africa. The results indicate that chemical cues can facilitate invasion success as the behavioural response of native gastropods is to move away allowing additional food and space resources to become available to T. granifera.

  17. APPROACHES ON THE INVASIVE ALIEN TAXA IN ROMANIA - AMBROSIA ARTEMISIIFOLIA (RAGWEED I

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    Nicoleta IANOVICI

    2009-01-01

    Full Text Available The aim of the present contribution was to determine the situation of Ambrosia artemisiifolia in Romania. A. artemisiifolia has a pronounced invasive character and is anemophilous, contrary to most Asteraceae. This paper is a brief summary about the researches on the alien plant Ambrosia artemisiifolia in Romania. At present, this alien plant is in the process of acclimatization and naturalization in our country. Till now it has indicated from all Romanian provinces, the spread of this taxon through our country is still incomplete known, at about a century since its first identification at Orşova. Nowadays the agricultural areas are greatly infested in Romania. However, the infestations on waste land or roadsides are rarely controlled. The annual pollen counts show an increasing tendency, indicating an increased local population. Ambrosia artemisiifolia has been studied by a high number of romanian scientists and many articles have been written on the topic. For the study of the spreading of the Ambrosia artemisiifolia L. species in the Western field of the country it was established as a study perimeter an areal which situates between the adminitrative limits of Timiş county. In 2008 the presence of the species was noticed in 49 locations. In 2009 - 2011, the observations continued and it was observed the emergence of the species in 28 new locations, also the expansion and amplification in the pryor locations. In the years 2010-2011 have been made many observations in other 33 counties and Bucureşti. The determinations were made in the months of June-September. In this work were listed a number of sites across Romania, where A. artemisiifolia vegetate. Currently the biggest problem is in the lowland and hill area of macro-regions 1, 3 and 4 where the species A. artemisiifolia is found in the extensive and diverse ecosystems. The paper presents personal observations on some morphological features, anatomical and ecological aspects.

  18. Perception and Understanding of Invasive Alien Species Issues by Nature Conservation and Horticulture Professionals in Belgium

    Science.gov (United States)

    Vanderhoeven, Sonia; Piqueray, Julien; Halford, Mathieu; Nulens, Greet; Vincke, Jan; Mahy, Grégory

    2011-03-01

    We conducted a survey to determine how two professional sectors in Belgium, horticulture professionals and nature reserve managers (those directly involved in conservation), view the issues associated with invasive plant species. We developed and utilized a questionnaire that addressed the themes of awareness, concept and use of language, availability of information, impacts and, finally, control and available solutions. Using co-inertia analyses, we tested to what extent the perception of invasive alien species (IAS) was dependent upon the perception of Nature in general. Only forty-two percent of respondent horticulture professionals and eighty-two percent of nature reserve managers had a general knowledge of IAS. Many individuals in both target groups nonetheless had an accurate understanding of the scientific issues. Our results therefore suggest that the manner in which individuals within the two groups view, or perceive, the IAS issue was more the result of lack of information than simply biased perceptions of target groups. Though IAS perceptions by the two groups diverged, they were on par with how they viewed Nature in general. The descriptions of IAS by participants converged with the ideas and concepts frequently found in the scientific literature. Both managers and horticulture professionals expressed a strong willingness to participate in programs designed to prevent the spread of, and damage caused by, IAS. Despite this, the continued commercial availability of many invasive species highlighted the necessity to use both mandatory and voluntary approaches to reduce their re-introduction and spread. The results of this study provide stakeholders and conservation managers with practical information on which communication and management strategies can be based.

  19. Invasion by the Alien Tree Prunus serotina Alters Ecosystem Functions in a Temperate Deciduous Forest.

    Science.gov (United States)

    Aerts, Raf; Ewald, Michael; Nicolas, Manuel; Piat, Jérôme; Skowronek, Sandra; Lenoir, Jonathan; Hattab, Tarek; Garzón-López, Carol X; Feilhauer, Hannes; Schmidtlein, Sebastian; Rocchini, Duccio; Decocq, Guillaume; Somers, Ben; Van De Kerchove, Ruben; Denef, Karolien; Honnay, Olivier

    2017-01-01

    Alien invasive species can affect large areas, often with wide-ranging impacts on ecosystem structure, function, and services. Prunus serotina is a widespread invader of European temperate forests, where it tends to form homogeneous stands and limits recruitment of indigenous trees. We hypotesized that invasion by P. serotina would be reflected in the nutrient contents of the native species' leaves and in the respiration of invaded plots as efficient resource uptake and changes in nutrient cycling by P. serotina probably underly its aggressive invasiveness. We combined data from 48 field plots in the forest of Compiègne, France, and data from an experiment using 96 microcosms derived from those field plots. We used general linear models to separate effects of invasion by P. serotina on heterotrophic soil and litter respiration rates and on canopy foliar nutrient content from effects of soil chemical properties, litter quantity, litter species composition, and tree species composition. In invaded stands, average respiration rates were 5.6% higher for soil (without litter) and 32% higher for soil and litter combined. Compared to indigenous tree species, P. serotina exhibited higher foliar N (+24.0%), foliar P (+50.7%), and lower foliar C:N (-22.4%) and N:P (-10.1%) ratios. P. serotina affected foliar nutrient contents of co-occuring indigenous tree species leading to decreased foliar N (-8.7 %) and increased C:N ratio (+9.5%) in Fagus sylvatica, decreased foliar N:P ratio in Carpinus betulus (-13.5%) and F. sylvatica (-11.8%), and increased foliar P in Pinus sylvestris (+12.3%) in invaded vs. uninvaded stands. Our results suggest that P. serotina is changing nitrogen, phosphorus, and carbon cycles to its own advantage, hereby increasing carbon turnover via labile litter, affecting the relative nutrient contents in the overstory leaves, and potentially altering the photosynthetic capacity of the long-lived indigenous broadleaved species. Uncontrolled invasion of

  20. Invasion by the Alien Tree Prunus serotina Alters Ecosystem Functions in a Temperate Deciduous Forest

    Science.gov (United States)

    Aerts, Raf; Ewald, Michael; Nicolas, Manuel; Piat, Jérôme; Skowronek, Sandra; Lenoir, Jonathan; Hattab, Tarek; Garzón-López, Carol X.; Feilhauer, Hannes; Schmidtlein, Sebastian; Rocchini, Duccio; Decocq, Guillaume; Somers, Ben; Van De Kerchove, Ruben; Denef, Karolien; Honnay, Olivier

    2017-01-01

    Alien invasive species can affect large areas, often with wide-ranging impacts on ecosystem structure, function, and services. Prunus serotina is a widespread invader of European temperate forests, where it tends to form homogeneous stands and limits recruitment of indigenous trees. We hypotesized that invasion by P. serotina would be reflected in the nutrient contents of the native species' leaves and in the respiration of invaded plots as efficient resource uptake and changes in nutrient cycling by P. serotina probably underly its aggressive invasiveness. We combined data from 48 field plots in the forest of Compiègne, France, and data from an experiment using 96 microcosms derived from those field plots. We used general linear models to separate effects of invasion by P. serotina on heterotrophic soil and litter respiration rates and on canopy foliar nutrient content from effects of soil chemical properties, litter quantity, litter species composition, and tree species composition. In invaded stands, average respiration rates were 5.6% higher for soil (without litter) and 32% higher for soil and litter combined. Compared to indigenous tree species, P. serotina exhibited higher foliar N (+24.0%), foliar P (+50.7%), and lower foliar C:N (−22.4%) and N:P (−10.1%) ratios. P. serotina affected foliar nutrient contents of co-occuring indigenous tree species leading to decreased foliar N (−8.7 %) and increased C:N ratio (+9.5%) in Fagus sylvatica, decreased foliar N:P ratio in Carpinus betulus (−13.5%) and F. sylvatica (−11.8%), and increased foliar P in Pinus sylvestris (+12.3%) in invaded vs. uninvaded stands. Our results suggest that P. serotina is changing nitrogen, phosphorus, and carbon cycles to its own advantage, hereby increasing carbon turnover via labile litter, affecting the relative nutrient contents in the overstory leaves, and potentially altering the photosynthetic capacity of the long-lived indigenous broadleaved species. Uncontrolled

  1. The application of the European strategy on invasive alien species: an example with introduced squirrels

    Directory of Open Access Journals (Sweden)

    Sandro Bertolino

    2005-06-01

    Full Text Available Abstract We assessed the cases of squirrel species already introduced into Italy inside the framework proposed by the European strategy on invasive alien species. We collected information on 9 introductions that originated 8 populations: 3 of grey squirrels (Sciurus carolinensis, 2 of Finlayson's squirrels (Callosciurus finlaysonii, and 3 of Siberian chip-munks (Eutamias sibiricus. Food opportunism and high reproductive rate may explain the high success rate in establishing new populations, even with a low propagule pressure. A negative impact on the red squirrel (Sciurus vulgaris and damage to forestry and manufactures have been recorded in the areas of introduction. Accordingly to the European strategy, Italy is called to build-up a rapid response system in order to avoid further releases of alien squirrels in the wild. Meanwhile these species must be considered as a priority for trade restriction. Considering the risks posed to biodiversity and human activities, Italy must adopt a precautionary principle, removing small nuclei of introduced species before they spread in large areas. Riassunto Applicazione della strategia europea sulle specie non indigene: un esempio con gli scoiattoli introdotti Come esempio di applicazione della strategia europea sulle specie invasive introdotte, abbiamo analizzato la situazione degli scoiattoli introdotti in Italia. Su 9 introduzioni registrate, in 8 casi si sono formate popolazioni naturalizzate: 3 di scoiattolo grigio (Sciurus carolinensis, 2 di scoiattolo di Finlayson (Callosciurus finlaysonii e 3 di tamia siberiano (Eutamias sibiricus. L'alto successo delle introduzioni, anche a partire da pochi animali rilasciati, è probabilmente legato all'opportunismo alimentare delle specie considerate e al loro elevato tasso riproduttivo. Al momento, nelle aree di introduzione sono segnalati fenomeni

  2. Ecdysteroids in the adults and eggs of Opogona sacchari (Bojer), an invasive alien pest

    Institute of Scientific and Technical Information of China (English)

    WANG FangHai; ZHANG GuRen; WEN RuiZhen; HE GuoFeng

    2008-01-01

    In order to understand the composition and quantitative variation of ecdysteriods in the adults and eggs of Opogona sacchari (Bojer), an invasive alien pest, we analyzed the ecdysteroid composition and titers in the adult and egg of this pest. On day 4 after eclosion, the titer of ecdysteriods in the male adult was 0.080 ng/sdult, much lower than 5.978 ng/adult in the female adult. During the development of ovaries, the titer of ecdysteriods was low on the first two days, and high in the late period, with the peak (10.48 ng/ovary) appearing on day 3. During the development of eggs, the titer of ecdysteriods was about 0.010 ng/egg from day I to day 3, and then decreased to 0.006 ng/egg on day 4. In both adults and eggs, three main components of ecdysteriods were found by identification of HPLC/RIA. They were 20-hydroxyecdysone, 26-hydroxyecdysone, and an unidentified component.

  3. Ecdysteroids in the pupae of Opogona sacchari (Bojer), a new invasive alien pest

    Institute of Scientific and Technical Information of China (English)

    WANG Fanghai; ZHANG Guren; WEN Ruizhen; HE Guofeng

    2006-01-01

    In order to understand the composition and quantitative variation of ecdysteriods in the pupae of Opogona sacchari (Bojer), a new invasive alien pest, we analyzed the pupal ecdysteroid composition and titers in this pest. The main component of ecdysteriods in the pupae of O. sacchari is 20-hydroxyecdysone. The titre of ecdysteriods in both male pupae and female pupae get higher gradually, and then decreased slowly after reaching a peak (80 ng/pupa). The titre of ecdysteriods was about 30 ng/pupa in the later stage of pupae. The peak of male pupae appeared on the third day, but the peak of female pupae lasted from the second day to the fourth day during pupal developments. The ecdysteroid content was higher in female pupae than in male pupae during specific pupal time (the 1st, 2nd, 4th, 5th, 6th day). We also found that the titre of ecdysteroids in posterior part of pupae was higher than in anterior part of pupae obviously.

  4. The large-scale removal of mammalian invasive alien species in Northern Europe.

    Science.gov (United States)

    Robertson, Peter A; Adriaens, Tim; Lambin, Xavier; Mill, Aileen; Roy, Sugoto; Shuttleworth, Craig M; Sutton-Croft, Mike

    2017-02-01

    Numerous examples exist of successful mammalian invasive alien species (IAS) eradications from small islands (<10 km(2) ), but few from more extensive areas. We review 15 large-scale removals (mean area 2627 km(2) ) from Northern Europe since 1900, including edible dormouse, muskrat, coypu, Himalayan porcupine, Pallas' and grey squirrels and American mink, each primarily based on daily checking of static traps. Objectives included true eradication or complete removal to a buffer zone, as distinct from other programmes that involved local control to limit damage or spread. Twelve eradication/removal programmes (80%) were successful. Cost increased with and was best predicted by area, while the cost per unit area decreased; the number of individual animals removed did not add significantly to the model. Doubling the area controlled reduced cost per unit area by 10%, but there was no evidence that cost effectiveness had increased through time. Compared with small islands, larger-scale programmes followed similar patterns of effort in relation to area. However, they brought challenges when defining boundaries and consequent uncertainties around costs, the definition of their objectives, confirmation of success and different considerations for managing recolonisation. Novel technologies or increased use of volunteers may reduce costs. Rapid response to new incursions is recommended as best practice rather than large-scale control to reduce the environmental, financial and welfare costs. © 2016 Crown copyright. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

  5. Ecdysteroids in the adults and eggs of Opogona sacchari (Bojer),an invasive alien pest

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    In order to understand the composition and quantitative variation of ecdysteriods in the adults and eggs of Opogona sacchari (Bojer), an invasive alien pest, we analyzed the ecdysteroid composition and titers in the adult and egg of this pest. On day 4 after eclosion, the titer of ecdysteriods in the male adult was 0.080 ng/adult, much lower than 5.978 ng/adult in the female adult. During the development of ovaries, the titer of ecdysteriods was low on the first two days, and high in the late period, with the peak (10.48 ng/ovary) appearing on day 3. During the development of eggs, the titer of ecdysteriods was about 0.010 ng/egg from day 1 to day 3, and then decreased to 0.006 ng/egg on day 4. In both adults and eggs, three main components of ecdysteriods were found by identification of HPLC/RIA. They were 20-hydroxyecdysone, 26-hydroxyecdysone, and an unidentified component.

  6. Potential Distribution of Alien Invasive Species and Risk Assessment: a Case Study of Erwinia amylovora in China

    Institute of Scientific and Technical Information of China (English)

    CHEN Chen; CHEN Juan; HU Bai-shi; JIANG Ying-hua; LIU Feng-quan

    2007-01-01

    Alien invasive species represent a severe risk to biodiversity and economy, as in the case of fire blight (Erwinia amylovora), a bacterial disease that originated in North America, which may be released into new locations by means of fruit trade. On the basis of the knowledge of Erwinia amylovora's biophysical characteristics and environmental data, the geographic information system (GIS) has been applied to determine areas where Erwinia amylovora can potentially invade China. Temperature and precipitation, during the blossoming period, are considered to be two critical factors affecting the Erwinia amylovora's suitable climatic zones. This spatial modeling approach was validated from a case study in Europe, where the occurrence of Erwinia amylovora has been proven. The model prediction agreed with the occurrence of the bacteria recorded in Europe, and the same procedure has been applied to produce a potential establishment area in China's two preferential apple cultivation regions, Bohai Bay region and Huangtu Altiplano region. It has been found that areas belonging to the high-risk category are more or less the main apple producing areas, accounting for their great economic importance in China. This methodology provides an initial baseline for assessment, prevention, and management of alien species that may become invasive under certain environmental conditions. In addition, this modeling approach provides a tool for policy makers to use, in making decisions on management practices where alien species are involved.

  7. Salmonella infection in green anoles (Anolis carolinensis), an invasive alien species on Chichi Island of the Ogasawara archipelago in Japan.

    Science.gov (United States)

    Sumiyama, Daisuke; Izumiya, Hidemasa; Kanazawa, Tomoko; Murata, Koichi

    2014-03-01

    We investigated the presence of Salmonella in the green anole (Anolis carolinensis), an invasive alien species on Chichi Island, Japan. Samples were also collected from feral goats and public toilets on the island to examine infectious routes. Salmonellae were isolated from 27.1% of 199 samples; 32.6% of 141 cloacal samples from anoles, 62.5% of 8 intestinal samples from anole carcasses, 16.7% of 12 fecal samples from goats and 2.6% of 38 toilet bowl swabs. The serotype of most isolates was Salmonella Oranienburg (94.4% of 54). Although we did not confirm the infection pathways, our results indicated that green anoles are a risk factor as a source of Salmonella for public health. It is important to consider endemic pathogens that may be amplified by alien species within their introduced areas.

  8. Conserving a geographically isolated Charaxes butterfly in response to habitat fragmentation and invasive alien plants

    Directory of Open Access Journals (Sweden)

    Casparus J. Crous

    2015-03-01

    Full Text Available In South Africa, much of the forest biome is vulnerable to human-induced disturbance. The forest-dwelling butterfly Charaxes xiphares occidentalis is naturally confined to a small forest region in the south-western Cape, South Africa. Most of the remaining habitat of this species is within a fragmented agricultural matrix. Furthermore, this geographical area is also heavily invaded by alien plants, especially Acacia mearnsii. We investigated how C. x. occidentalis behaviourally responds to different habitat conditions in the landscape. We were particularly interested in touring, patrolling and settling behaviour as a conservation proxy for preference of a certain habitat configuration in this agricultural matrix. Remnant forest patches in the agricultural matrix showed fewer behavioural incidents than in a reference protected area. Moreover, dense stands of A. mearnsii negatively influenced the incidence and settling pattern of this butterfly across the landscape, with fewer tree settlings associated with more heavily invaded forest patches. This settling pattern was predominantly seen in female butterflies. We also identified specific trees that were settled upon for longer periods by C. x. occidentalis. Distance to a neighbouring patch and patch size influenced behavioural incidences, suggesting that further patch degradation and isolation could be detrimental to this butterfly. Conservation implications: We highlight the importance of clearing invasive tree species from vulnerable forest ecosystems and identify key tree species to consider in habitat conservation and rehabilitation programmes for this butterfly. We also suggest retaining as much intact natural forest as possible. This information should be integrated in local biodiversity management plans.

  9. Response measures of invasive alien species%外来生物入侵及应对措施

    Institute of Scientific and Technical Information of China (English)

    张凌峰

    2015-01-01

    Taking the biological invasion in The Kunming World Horticultural Expo Garden as example, this article analyzes in detail the causes of biological invasion and control measures. Results of the research provide a reference to alien biological invasion prevention and eco-security studies for Kunming World expo garden as well as the whole area of Kunming.%以昆明世界园艺博览园(以下简称世博园)内生物入侵的现状为例,分析其产生原因及防治对策,为世博园及整个昆明地区外来生物入侵的防范和生态安全提供参考。

  10. DEVELOPMENT OF AN INDEX OF ALIEN SPECIES INVASIVENESS: AN AID TO ASSESSING RIPARIAN VEGETATION CONDITION

    Science.gov (United States)

    Many riparian areas are invaded by alien plant species that negatively affect native species composition, community dynamics and ecosystem properties. We sampled vegetation along reaches of 31 low order streams in eastern Oregon, and characterized species assemblages at patch an...

  11. Seed dispersal networks in the Galápagos and the consequences of alien plant invasions

    DEFF Research Database (Denmark)

    Heleno, R. H.; Olesen, Jens Mogens; Nogales, M.

    2013-01-01

    Alien plants are a growing threat to the Gala´pagos unique biota. We evaluated the impact of alien plants on eight seed dispersal networks from two islands of the archipelago. Nearly 10 000 intact seeds from 58 species were recovered from the droppings of 18 bird and reptile dispersers. The most...... plants were dispersed via two pathways: dryfruited plants were preferentially dispersed by finches, while fleshy fruited species were mostly dispersed by other birds and reptiles....

  12. First occurrence of the invasive alien species Polydora cornuta Bosc, 1802 (Polychaeta: Spionidae on the coast of Greece (Elefsis Bay; Aegean Sea

    Directory of Open Access Journals (Sweden)

    N. SIMBOURA

    2012-12-01

    Full Text Available The present study reports on the occurrence of two specimens of the alien species Polydora cornutaBosc, 1802, in Elefsis Bay, the Saronikos Gulf (Aegean Sea, eastern Mediterranean. This is the firstrecord of this invasive alien species on the coast of Greece and the second report in the eastern MediterraneanSea after its first finding in Izmir Bay (on the Turkish Aegean coast. This finding enhances its distributionalpattern within the Mediterranean

  13. Invasive alien species in the food chain: Advancing risk assessment models to address climate change, economics and uncertainty

    Directory of Open Access Journals (Sweden)

    Darren Kriticos

    2013-09-01

    Full Text Available Pest risk maps illustrate where invasive alien arthropods, molluscs, pathogens, and weeds might become established, spread, and cause harm to natural and agricultural resources within a pest risk area. Such maps can be powerful tools to assist policymakers in matters of international trade, domestic quarantines, biosecurity surveillance, or pest-incursion responses. The International Pest Risk Mapping Workgroup (IPRMW is a group of ecologists, economists, modellers, and practising risk analysts who are committed to improving the methods used to estimate risks posed by invasive alien species to agricultural and natural resources. The group also strives to improve communication about pest risks to biosecurity, production, and natural-resource-sector stakeholders so that risks can be better managed. The IPRMW previously identified ten activities to improve pest risk assessment procedures, among these were: “improve representations of uncertainty, … expand communications with decision-makers on the interpretation and use of risk maps, … increase international collaboration, … incorporate climate change, … [and] study how human and biological dimensions interact” (Venette et al. 2010.

  14. An assessment of alien invasive plant species in Gonarezhou National Park, Zimbabwe

    NARCIS (Netherlands)

    Sithole, D.; Zisadza-Gandiwa, P.; Gandiwa, E.

    2012-01-01

    This study investigated the occurrence of alien plant species in Gonarezhou National Park (GNP), Zimbabwe. We focused on two main habitat types, namely riparian areas of the major rivers and dry land areas. Sampling was carried out from 42 sampling plots in both habitat types. Variables studied incl

  15. Studies on Legislation of Preventing and Controlling of Invasive Alien Species%防治外来物种入侵立法研究

    Institute of Scientific and Technical Information of China (English)

    刘欣庆; 李景明; 孙玉芳

    2012-01-01

    With the rapid economic development as well as continuously strengthening of international exchanges, the invasion of alien species is becoming increasingly serious and caused significant harm to the country's economic, cultural, ecological and human health. By analysis of legislation of international community for preventing and controlling invasive alien species, China's legislative problems of preventing and controlling invasive alien species were studied. Suggestions to modify current laws and regulations were proposed for comprehensive construction of China's legislation of prevention and control of alien invasive species.%随着经济的快速发展以及国际交流的不断加强,外来物种入侵的现象日益严重,给我国的经济、文化、生态以及人类健康造成了重大的危害。文章通过分析国际社会外来物种入侵立法情况,研究了我国在防治外来物种入侵立法方面存在的问题,并对现有法律法规中的有关内容提出了修改和完善的建议,以期为全面加强我国防治外来物种入侵立法提供借鉴。

  16. Torrefaction of invasive alien plants: Influence of heating rate and other conversion parameters on mass yield and higher heating value.

    Science.gov (United States)

    Mundike, Jhonnah; Collard, François-Xavier; Görgens, Johann F

    2016-06-01

    With the aim of controlling their proliferation, two invasive alien plants, Lantana camara (LC) and Mimosa pigra (MP), both widespread in Africa, were considered for torrefaction for renewable energy applications. Using thermogravimetric analysis, the influence of heating rate (HR: 2.18-19.82°Cmin(-1)) together with variable temperature and hold time on char yield and HHV (in a bomb calorimeter) were determined. Statistically significant effects of HR on HHV with optima at 10.5°Cmin(-1) for LC and 20°Cmin(-1) for MP were obtained. Increases of HHV up to 0.8MJkg(-1) or energy yield greater than 10%, together with a 3-fold reduction in torrefaction conversion time could be achieved by optimisation of HR. Analysis of the torrefaction volatiles by TG-MS showed that not only hemicelluloses, but also lignin conversion, could influence the optimum HR value.

  17. Differences found in the macroinvertebrate community composition in the presence or absence of the invasive alien crayfish, Orconectes hylas

    Science.gov (United States)

    Freeland-Riggert, Brandye T.; Cairns, Stefan H.; Poulton, Barry C.; Riggert, Chris M.

    2016-01-01

    Introductions of alien species into aquatic ecosystems have been well documented, including invasions of crayfish species; however, little is known about the effects of these introductions on macroinvertebrate communities. The woodland crayfish (Orconectes hylas (Faxon)) has been introduced into the St. Francis River watershed in southeast Missouri and has displaced populations of native crayfish. The effects of O. hylas on macroinvertebrate community composition were investigated in a fourth-order Ozark stream at two locations, one with the presence of O. hylas and one without. Significant differences between sites and across four sampling periods and two habitats were found in five categories of benthic macroinvertebrate metrics: species richness, percent/composition, dominance/diversity, functional feeding groups, and biotic indices. In most seasons and habitat combinations, the invaded site had significantly higher relative abundance of riffle beetles (Coleoptera: Elmidae), and significantly lower Missouri biotic index values, total taxa richness, and both richness and relative abundance of midges (Diptera: Chironomidae). Overall study results indicate that some macroinvertebrate community differences due to the O. hylas invasion were not consistent between seasons and habitats, suggesting that further research on spatial and temporal habitat use and feeding ecology of Ozark crayfish species is needed to improve our understanding of the effects of these invasions on aquatic communities.

  18. Does mutualism drive the invasion of two alien species? The case of Solenopsis invicta and Phenacoccus solenopsis.

    Directory of Open Access Journals (Sweden)

    Aiming Zhou

    Full Text Available Although mutualism between ants and honeydew-producing hemipterans has been extensively recognized in ecosystem biology, however few attempts to test the hypothesis that mutualism between two alien species leads to the facilitation of the invasion process. To address this problem, we focus on the conditional mutualism between S. invicta and P. solenopsis by field investigations and indoor experiments. In the laboratory, ant colony growth increased significantly when ants had access to P. solenopsis and animal-based food. Honeydew produced by P. solenopsis also improved the survival of ant workers. In the field, colony density of P. solenopsis was significantly greater on plots with ants than on plots without ants. The number of mealybug mummies on plants without fire ants was almost three times that of plants with fire ants, indicating a strong effect of fire ants on mealybug survival. In addition, the presence of S. invicta successfully contributed to the spread of P. solenopsis. The quantity of honeydew consumption by S. invicta was significantly greater than that of a presumptive native ant, Tapinoma melanocephalum. When compared with the case without ant tending, mealybugs tended by ants matured earlier and their lifespan and reproduction increased. T. melanocephalum workers arrived at honeydew more quickly than S. invicta workers, while the number of foraging S. invicta workers on plants steadily increased, eventually exceeding that number of T. melanocephalum foragers. Overall, these results suggest that the conditional mutualism between S. invicta and P. solenopsis facilitates population growth and fitness of both species. S. invicta tends to acquire much more honeydew and drive away native ants, promoting their predominance. These results suggest that the higher foraging tempo of S. invicta may provide more effective protection of P. solenopsis than native ants. Thus mutualism between these two alien species may facilitate the invasion

  19. Fire and simulated herbivory have antagonistic effects on resistance of savanna grasslands to alien shrub invasion

    NARCIS (Netherlands)

    te Beest, Mariska; Mpandza, Nokukhanya J.; Olff, Han

    2015-01-01

    Question Resistance of the native community has been identified as an important factor limiting invasion success and invader impact. However, to what extent resistance interacts with disturbance to control invasion success remains unclear. We studied the interaction between biotic resistance, fire a

  20. Past and estimated future impact of invasive alien mammals on insular threatened vertebrate populations.

    Science.gov (United States)

    McCreless, Erin E; Huff, David D; Croll, Donald A; Tershy, Bernie R; Spatz, Dena R; Holmes, Nick D; Butchart, Stuart H M; Wilcox, Chris

    2016-08-18

    Invasive mammals on islands pose severe, ongoing threats to global biodiversity. However, the severity of threats from different mammals, and the role of interacting biotic and abiotic factors in driving extinctions, remain poorly understood at a global scale. Here we model global extirpation patterns for island populations of threatened and extinct vertebrates. Extirpations are driven by interacting factors including invasive rats, cats, pigs, mustelids and mongooses, native species taxonomic class and volancy, island size, precipitation and human presence. We show that controlling or eradicating the relevant invasive mammals could prevent 41-75% of predicted future extirpations. The magnitude of benefits varies across species and environments; for example, managing invasive mammals on small, dry islands could halve the extirpation risk for highly threatened birds and mammals, while doing so on large, wet islands may have little benefit. Our results provide quantitative estimates of conservation benefits and, when combined with costs in a return-on-investment framework, can guide efficient conservation strategies.

  1. Study on the Invasive Alien Plants in South China%华南地区外来人侵植物调查研究

    Institute of Scientific and Technical Information of China (English)

    林建勇; 梁瑞龙; 李娟; 黄应钦

    2012-01-01

    根据野外调查和相关资料整理,探讨华南地区入侵植物的种类组成、来源、生长型,比较不同地区间种类组成的相似性,预测部分危险性较大的入侵种的扩散趋势。研究表明:华南三省共有外来入侵植物148种,属于41科105属,其中广东、广西、海南分别为132、129、100种,以菊科(Asteraceae)、禾本科(Gramineae)和苋科(Amaranthaceae)的种类最多。美洲起源的入侵种最多,共有108种,占总种数73.0%。草本型入侵植物种类最多,共有114种,占总物种数77.0%。广东和广西两省入侵植物组成的相似性最大,广西和海南的相似性最低。%According to field investigation and relative data, the species composition, origin and life form were studied, the similarity of different species in different areas was compared, and the spread- ing tendency on part of high dangerous invasive alien plants was predicted. The study showed that 148 species of invasive alien plants belonging to 105 genera of 41 families were identified in three provinces of South China. There were 132 species of invasive alien plants in Guangdong, 129 species in Guangxi and 100 species in Hainan, in which the most were Asteraceae, Gramineae and Amaranthaceae. The most of the invasive alien plants were from America with 108 species, taking up 73.0% of the total species. The species of herbaceous invasive alien plants were the most with 114 species, taking up 77.0 %. The similarity of species composition of invasive alien plants between Guangdong and Guangxi was the highest, the lowest between Guangxi and Hainan.

  2. 历山自然保护区外来入侵植物研究%Study on Invasive Alien Plants in Lishan Nature Reserve, Shanxi

    Institute of Scientific and Technical Information of China (English)

    马世军; 王建军

    2011-01-01

    The invasive alien plants in Lishan Nature Reserve, Shanxi, totally 11 species, were studied,including Chenopodium hybridum ,Amaranthus retroflexus ,Vaccaria segetalis ,Melilotus albus , Hibisicus trio-num , Ipomoea purpurea ,Datura stramonium ,Conyza Canadensis ,Erigeron annuus ,Sonchus oleraceus and Avena fatua. The diffusing mechanism, invasion route, distribution, habitat, ecological damage and utilization value for those invasive alien plants were analyzed,respectively. Moreover,the management strategies for those invasive alien species were also discussed, including mechanical, chemical and biological controls and strengthening research of diffusing mechanism.%历山自然保护区的外来入侵植物有11种,分别是杂配藜、反枝苋、王不留行、白香草木樨、野西瓜苗、圆叶牵牛、曼陀罗、小蓬草、一年蓬、苦苣菜、野燕麦等.本文论述了它们的入侵途径、分布、生境、危害及利用价值,提出了对外来入侵植物的管理对策,包括人工措施、化学措施、生物措施、加强扩散机制研究等.

  3. Past and estimated future impact of invasive alien mammals on insular threatened vertebrate populations

    Science.gov (United States)

    McCreless, Erin E.; Huff, David D.; Croll, Donald A.; Tershy, Bernie R.; Spatz, Dena R.; Holmes, Nick D.; Butchart, Stuart H. M.; Wilcox, Chris

    2016-01-01

    Invasive mammals on islands pose severe, ongoing threats to global biodiversity. However, the severity of threats from different mammals, and the role of interacting biotic and abiotic factors in driving extinctions, remain poorly understood at a global scale. Here we model global extirpation patterns for island populations of threatened and extinct vertebrates. Extirpations are driven by interacting factors including invasive rats, cats, pigs, mustelids and mongooses, native species taxonomic class and volancy, island size, precipitation and human presence. We show that controlling or eradicating the relevant invasive mammals could prevent 41–75% of predicted future extirpations. The magnitude of benefits varies across species and environments; for example, managing invasive mammals on small, dry islands could halve the extirpation risk for highly threatened birds and mammals, while doing so on large, wet islands may have little benefit. Our results provide quantitative estimates of conservation benefits and, when combined with costs in a return-on-investment framework, can guide efficient conservation strategies. PMID:27535095

  4. Selective logging and fire as drivers of alien grass invasion in a Bolivian tropical dry forest

    NARCIS (Netherlands)

    Veldman, J.W.; Mostacedo, B.; Peña-Claros, M.; Putz, F.E.

    2009-01-01

    Logging is an integral component of most conceptual models that relate human land-use and climate change to tropical deforestation via positive-feedbacks involving fire. Given that grass invasions can substantially alter fire regimes, we studied grass distributions in a tropical dry forest 1-5 yr af

  5. Hybridization and Sexual Reproduction in the Invasive Alien Fallopia (Polygonaceae) Complex in Belgium

    Science.gov (United States)

    Tiébré, Marie-Solange; Vanderhoeven, Sonia; Saad, Layla; Mahy, Grégory

    2007-01-01

    Background and Aims The knotweed complex, Fallopia spp. (Polygonaceae), belongs to the most troublesome invasive species in Europe and North America. Vegetative regeneration is widely recognized as the main mode of reproduction in the adventive regions. However, the contribution of sexual reproduction to the success of these invasive species has only been detailed for the British Isles. An examination was made as to how hybridization may influence the sexual reproduction of the complex in Belgium and to determine how it may contribute to the dispersal of the species. Methods Studies were made of floral biology, reproductive success, seed rain, seed bank, germination capacity, seedling survival and dispersal capacity in order to characterize the reproductive biology of the species. Moreover, chromosome counts and flow cytometry were used to assess the hybrid status of seedlings produced by sexual reproduction. Key Results In the area investigated, extensive sexual reproduction by hybridization within the complex, including one horticultural species, was demonstrated. A small percentage of seeds may be dispersed outside the maternal clone (>16 m) allowing the formation of genetically differentiated individuals. Seed germination was possible even after a winter cold period. Conclusions The extensive sexual reproduction by hybridization could further contribute to the dramatic invasive success of knotweeds in Belgium and should not be underestimated when considering control and management measures. PMID:17210609

  6. Effects of an alien ant invasion on abundance, behavior, and reproductive success of endemic island birds.

    Science.gov (United States)

    Davis, Naomi E; O'Dowd, Dennis J; Green, Peter T; Nally, Ralph Mac

    2008-10-01

    Biological invaders can reconfigure ecological networks in communities, which changes community structure, composition, and ecosystem function. We investigated whether impacts caused by the introduced yellow crazy ant (Anoplolepis gracilipes), a pantropical invader rapidly expanding its range, extend to higher-order consumers by comparing counts, behaviors, and nesting success of endemic forest birds in ant-invaded and uninvaded rainforest on Christmas Island (Indian Ocean). Point counts and direct behavioral observations showed that ant invasion altered abundances and behaviors of the bird species we examined: the Island Thrush (Turdus poliocephalus erythropleurus), Emerald Dove (Chalcophaps indica natalis), and Christmas Island White-eye (Zosterops natalis). The thrush, which frequents the forest floor, altered its foraging and reproductive behaviors in ant-invaded forest, where nest-site location changed, and nest success and juvenile counts were lower. Counts of the dove, which forages exclusively on the forest floor, were 9-14 times lower in ant-invaded forest. In contrast, counts and foraging success of the white-eye, a generalist feeder in the understory and canopy, were higher in ant-invaded forest, where mutualism between the ant and honeydew-secreting scale insects increased the abundance of scale-insect prey. These complex outcomes involved the interplay of direct interference by ants and altered resource availability and habitat structure caused indirectly by ant invasion. Ecological meltdown, rapidly unleashed by ant invasion, extended to these endemic forest birds and may affect key ecosystem processes, including seed dispersal.

  7. A review of invasive alien species impacts on eucalypt stands and citrus orchards ecosystem services: towards an integrated management approach.

    Science.gov (United States)

    Branco, Sofia; Videira, Nuno; Branco, Manuela; Paiva, Maria Rosa

    2015-02-01

    Multidisciplinary knowledge on the impact caused by invasive alien species (IAS) on ecosystems is crucial for guiding policy makers in the adoption of sustainable management measures. This research was focused on insect IAS impacts on two managed ecosystems: eucalypt plantations and citrus orchards. It begins with an identification of the wide range of ecosystem services (ES) and disservices provided by each of these managed ecosystems, according to the methodology proposed by the Millennium Ecosystem Assessment. Subsequently, a comprehensive review of studies that promoted the identification and valuation of direct and indirect impacts IAS impacts on these ecosystems was performed. From the synthesis of previous findings, an integrative management framework is advanced. This links the identification of ES, drivers of change and development of IAS management strategies by means of assessment processes that account for multiple dimensions of ES values. The article concludes with a discussion on the challenges underpinning assessment and valuation approaches that inform the design of inclusive strategies and interventions to tackle IAS impacts.

  8. Is there a need for a more explicit accounting of invasive alien species under the Water Framework Directive?

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    Jochen Vandekerkhove

    2013-01-01

    Full Text Available Through ratification of the Water Framework Directive (WFD, EU Member States committed themselves to a pressure-based assessment ofthe ecological status of their water bodies. Invasive alien species (IAS constitute a major pressure in many aquatic ecosystems, yet are notexplicitly accounted for by the majority of WFD assessment methods. Most Member States argue that no explicit assessment of IAS isrequired, assuming that significant IAS pressures will affect the WFD biological quality elements (BQEs, and be detected by generic WFDstatus assessments. We tested this assumption for a selection of country-by-surface-water category combinations, covering nearly 40,000water bodies. For each of the combinations, the pressure by high-impact IAS is higher in water bodies with ecological status varying from bad to moderate than in water bodies in good or high ecological status. Most high-impact IAS show strong associations with low status class categories. Of the 17 most frequently occurring high-impact IAS, only Mustela vison (Schreber, 1777 and Potamopyrgus antipodarum(Gray, 1853 are disproportionately frequent in high status water bodies. The sensitivity of WFD methods varies across BQEs, withmacrophyte-based methods showing a consistently high sensitivity to IAS pressures. However, significant pressures are observed in anumber of high status water bodies. This points to a need for further optimization of existing methods so that they address the full range of pressures exerted by IAS.

  9. Neighbour Origin and Ploidy Level Drive Impact of an Alien Invasive Plant Species in a Competitive Environment.

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    Yan Sun

    Full Text Available Our understanding of the potential mechanisms driving the spread and naturalization of alien plant species has increased over the past decades, but specific knowledge on the factors contributing to their increased impact in the introduced range is still urgently needed. The native European plant Centaurea stoebe occurs as two cytotypes with different life histories (monocarpic diploids, allo-polycarpic tetraploids. However, only tetraploids have been found in its introduced range in North America, where C. stoebe has become a most prominent plant invader. Here, we focus on the ploidy level of C. stoebe and origin of neighbouring community in explaining the high impact during the invasion of new sites in the introduced range. We conducted a mesocosm experiment under open-field conditions with the diploid (EU2x and tetraploid (EU4x cytotype of Centaurea stoebe from its native European (EU range, and with the invasive tetraploid (NA4x cytotype from the introduced North American (NA range in competition with EU (old or NA (new neighbouring plant communities. In the presence of competition, the biomass of EU neighbouring community was reduced to a comparable level by all three geo-cytotypes of C. stoebe. In contrast, the biomass of the NA neighbouring community was reduced beyond when competing with tetraploid, but not with diploid C. stoebe. The fact that the biomass of all three geo-cytotypes of C. stoebe was correlated with the biomass of the EU neighbouring community, but not with that of the NA neighbouring community suggests that different mechanisms underlie the competitive interactions between C. stoebe and its old vs. new neighbouring communities, such as competition for the same limiting resources at home vs competition through novel allelo-chemicals or differential resource uptake strategies in the introduced range. We therefore caution to simply use the ecosystem impact assessed at home to predict impact in the introduced range.

  10. Neighbour Origin and Ploidy Level Drive Impact of an Alien Invasive Plant Species in a Competitive Environment.

    Science.gov (United States)

    Sun, Yan; Müller-Schärer, Heinz; Schaffner, Urs

    2016-01-01

    Our understanding of the potential mechanisms driving the spread and naturalization of alien plant species has increased over the past decades, but specific knowledge on the factors contributing to their increased impact in the introduced range is still urgently needed. The native European plant Centaurea stoebe occurs as two cytotypes with different life histories (monocarpic diploids, allo-polycarpic tetraploids). However, only tetraploids have been found in its introduced range in North America, where C. stoebe has become a most prominent plant invader. Here, we focus on the ploidy level of C. stoebe and origin of neighbouring community in explaining the high impact during the invasion of new sites in the introduced range. We conducted a mesocosm experiment under open-field conditions with the diploid (EU2x) and tetraploid (EU4x) cytotype of Centaurea stoebe from its native European (EU) range, and with the invasive tetraploid (NA4x) cytotype from the introduced North American (NA) range in competition with EU (old) or NA (new) neighbouring plant communities. In the presence of competition, the biomass of EU neighbouring community was reduced to a comparable level by all three geo-cytotypes of C. stoebe. In contrast, the biomass of the NA neighbouring community was reduced beyond when competing with tetraploid, but not with diploid C. stoebe. The fact that the biomass of all three geo-cytotypes of C. stoebe was correlated with the biomass of the EU neighbouring community, but not with that of the NA neighbouring community suggests that different mechanisms underlie the competitive interactions between C. stoebe and its old vs. new neighbouring communities, such as competition for the same limiting resources at home vs competition through novel allelo-chemicals or differential resource uptake strategies in the introduced range. We therefore caution to simply use the ecosystem impact assessed at home to predict impact in the introduced range.

  11. Root-inhabiting fungi in alien plant species in relation to invasion status and soil chemical properties.

    Science.gov (United States)

    Majewska, Marta L; Błaszkowski, Janusz; Nobis, Marcin; Rola, Kaja; Nobis, Agnieszka; Łakomiec, Daria; Czachura, Paweł; Zubek, Szymon

    In order to recognize interactions between alien vascular plants and soil microorganisms and thus better understand the mechanisms of plant invasions, we examined the mycorrhizal status, arbuscular mycorrhizal fungi (AMF) colonization rate, arbuscular mycorrhiza (AM) morphology and presence of fungal root endophytes in 37 non-native species in Central Europe. We also studied the AMF diversity and chemical properties of soils from under these species. The plant and soil materials were collected in southern Poland. We found that 35 of the species formed AM and their mycorrhizal status depended on species identity. Thirty-three taxa had AM of Arum-type alone. Lycopersicon esculentum showed intermediate AM morphology and Eragrostis albensis developed both Arum and Paris. The mycelia of dark septate endophytes (DSE) were observed in 32 of the species, while sporangia of Olpidium spp. were found in the roots of 10. Thirteen common and worldwide occurring AMF species as well as three unidentified spore morphotypes were isolated from trap cultures established with the soils from under the plant species. Claroideoglomus claroideum, Funneliformis mosseae and Septoglomus constrictum were found the most frequently. The presence of root-inhabiting fungi and the intensity of their colonization were not correlated with soil chemical properties, plant invasion status, their local abundance and habitat type. No relationships were also found between the presence of AMF, DSE and Olpidium spp. These suggest that other edaphic conditions, plant and fungal species identity or the abundance of these fungi in soils might have an impact on the occurrence and intensity of fungal root colonization in the plants under study.

  12. Invasive, naturalized and casual alien plants in southern Africa: a sum­mary based on the Southern African Plant Invaders Atlas (SAPIA

    Directory of Open Access Journals (Sweden)

    L. Henderson

    2007-12-01

    Full Text Available The primary objective of this publication is to provide an overview of the species identity, invasion status, geographical extent, and abundance of alien plants in South Africa, Swaziland and Lesotho, based on field records from 1979 to the end of 2000. The dataset is all the species records for the study area in the Southern African Plant Invaders Atlas (SAPIA database during this time period. A total of 548 naturalized and casual alien plant species were catalogued and invasion was recorded almost throughout the study area. Most invasion, in terms of both species numbers and total species abundance, was recorded along the southern, southwestern and eastern coastal belts and in the adjacent interior. This area includes the whole of the Fynbos and Forest Biomes, and the moister eastern parts of the Grassland and Savanna Biomes. This study reinforces previous studies that the Fynbos Biome is the most extensively invaded vegetation type in South Africa but it also shows that parts of Savanna and Grassland are as heavily invaded as parts of the Fynbos. The Fabaceae is prominent in all biomes and Acacia with 17 listed species, accounts for a very large proportion of all invasion. Acacia mearmii was by far the most prominent invasive species in the study area, followed by A. saligna, Lantana camara, A. cyclops, Opuntia ficus-indica. Solarium mauritianum, Populus alba/xcanescens, Melia azedarach, A. dealbata and species of Prosopis.

  13. The role of habitat factors in successful invasion of alien plant Acer negundo in riparian zones.

    Science.gov (United States)

    Sikorski, Piotr; Sikorska, Daria

    2016-04-01

    Ash-leaved maple (Acer negundo) is one of the most invasive species occurring in riparian zones. The invasion is especially effective in disturbed areas, as the plant favours anthropogenic sites. The plant was also observed to be able to penetrate into sandy bars, also those separated from the land, inaccessible to people. It's removal is time-consuming and laborious, often involves damage done to sensitive vegetation and the results are doubtful, as the plant quickly regenerates. The invasion patterns and establishment of ash-leaved maple in natural ecosystems are poorly investigated. The aim of this study was to test how habitat factors such as: light availability, soil characteristics and competition contribute to ash-leaved maple effective colonization of natural sand bars free from anthropogenic pressure. In 2014 sand bars located in Vistula River Valley in Warsaw were inventoried and classified basing on their development stage as 1 - initial, 2 - unstable, 3 - stable. Apart from the occurrence of the invasive ash-leaved maple the plants competing with it were recognized and the percentage of the shoots of shrubs and herbaceous plants was estimated. PAR was measured at ground level and 1 meter above ground, the thickness of organic layer formed on the top of the sand was also measured as the indicator of sand bar development stage. The maple's survival in extremely difficult conditions resembles the strategy of willows and poplars naturally occurring in the riparian zones, which are well adapted to this environment. The success of invasion strongly depends on the plants establishment during sand bars initial stage of development. The seedlings growth correlates with the age of the sand bar (r1=0,41, r2=0,42 i r3=0,57). The colonization lasts for 4-6 years and the individuals start to cluster in bigger parches. After that period the maple turns into the phase of competition for space. Habitat factors such as shading (r2=0,41 i r3=0,51) and organic layer

  14. The invasion of five alien species in the Delta do Parnaíba Environmental Protection Area, Northeastern Brazil.

    Science.gov (United States)

    Loebmann, Daniel; Mai, Ana Cecília G; Lee, James T

    2010-09-01

    Marine biological invasions have been regarded as one of the major causes of native biodiversity loss, with shipping and aquaculture being the leading contributors for the introductions of alien species in aquatic ecosystems. In the present study, five aquatic alien species (one mollusk, three crustaceans and one fish species) were detected during dives, shore searches and from the fisheries on the coast of the Delta do Parnaíba Environmental Protection Area, in the States of Piauí and Maranhão, Northeastern Brazil. The species were the bicolor purse-oyster Isognomon bicolor, the whiteleg shrimp Litopenaeus vannamei, the giant river prawn Macrobrachium rosenbergii, the Indo-Pacific swimming crab Charybdis hellerii and, the muzzled blenny Omobranchus punctatus. Ballast water (I. bicolor, C. hellerii, and O. punctatus) and aquaculture activities (L. vannamei and M. rosenbergii) in adjacent areas are the most likely vectors of introduction. All exotic species found have potential impact risks to the environment because they are able to compete against native species for resources (food and habitat). Isognomon bicolor share the same habitat and food items with the native bivalve species of mussels and barnacles. Litopenaeus vannamei share the same habitat and food items with the native penaeids such as the pinkspot shrimp Farfantepenaeus brasiliensis, the Southern brown shrimp Farfantepenaeus subtilis, and the Southern white shrimp Litopenaeus schmitti, and in the past few years L. vannamei was responsible for a viral epidemics in the cultivation tanks that could be transmitted to native penaeid shrimps. Charybdis hellerii is also able to cause impacts on the local fisheries as the species can decrease the populations of native portunid crabs which are commercialized in the studied region. Macrobrachium rosenbergii may be sharing natural resources with the Amazon River prawn Macrobrachium amazonicum. Omobranchus punctatus shares habit with the native redlip blenny

  15. The prioritisation of invasive alien plant control projects using a multi-criteria decision model informed by stakeholder input and spatial data.

    Science.gov (United States)

    Forsyth, G G; Le Maitre, D C; O'Farrell, P J; van Wilgen, B W

    2012-07-30

    Invasions by alien plants are a significant threat to the biodiversity and functioning of ecosystems and the services they provide. The South African Working for Water program was established to address this problem. It needs to formulate objective and transparent priorities for clearing in the face of multiple and sometimes conflicting demands. This study used the analytic hierarchy process (a multi-criteria decision support technique) to develop and rank criteria for prioritising alien plant control operations in the Western Cape, South Africa. Stakeholder workshops were held to identify a goal and criteria and to conduct pair-wise comparisons to weight the criteria with respect to invasive alien plant control. The combination of stakeholder input (to develop decision models) with data-driven model solutions enabled us to include many alternatives (water catchments), that would otherwise not have been feasible. The most important criteria included the capacity to maintain gains made through control operations, the potential to enhance water resources and conserve biodiversity, and threats from priority invasive alien plant species. We selected spatial datasets and used them to generate weights that could be used to objectively compare alternatives with respect to agreed criteria. The analysis showed that there are many high priority catchments which are not receiving any funding and low priority catchments which are receiving substantial allocations. Clearly, there is a need for realigning priorities, including directing sufficient funds to the highest priority catchments to provide effective control. This approach provided a tractable, consensus-based solution that can be used to direct clearing operations.

  16. Evidence for shifts to faster growth strategies in the new ranges of invasive alien plants

    Science.gov (United States)

    Leishman, Michelle R; Cooke, Julia; Richardson, David M; Newman, Jonathan

    2014-01-01

    Summary Understanding the processes underlying the transition from introduction to naturalization and spread is an important goal of invasion ecology. Release from pests and pathogens in association with capacity for rapid growth is thought to confer an advantage for species in novel regions. We assessed leaf herbivory and leaf-level traits associated with growth strategy in the native and exotic ranges of 13 invasive plant species from 256 populations. Species were native to either the Western Cape region of South Africa, south-western Australia or south-eastern Australia and had been introduced to at least one of the other regions or to New Zealand. We tested for evidence of herbivore release and shifts in leaf traits between native and exotic ranges of the 13 species. Across all species, leaf herbivory, specific leaf area and leaf area were significantly different between native and exotic ranges while there were no significant differences across the 13 species found for leaf mass, assimilation rate, dark respiration or foliar nitrogen. Analysis at the species- and region-level showed that eight out of 13 species had reduced leaf herbivory in at least one exotic region compared to its native range. Six out of 13 species had significantly larger specific leaf area (SLA) in at least one exotic range region and five of those six species experienced reduced leaf herbivory. Increases in SLA were underpinned by increases in leaf area rather than reductions in leaf mass. No species showed differences in the direction of trait shifts from the native range between different exotic regions. This suggests that the driver of selection on these traits in the exotic range is consistent across regions and hence is most likely to be associated with factors linked with introduction to a novel environment, such as release from leaf herbivory, rather than with particular environmental conditions. Synthesis. These results provide evidence that introduction of a plant species into a

  17. Cabomba caroliniana A. Gray 1837: A new, alien and potentially invasive species in Serbia

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    Vukov Dragana

    2013-01-01

    Full Text Available During field studies of the vegetation in the canal network of the Hydro-System Danube-Tisa-Danube in Serbia, in 2008, 2011 and 2012, populations of Cabomba caroliniana A. Gray 1837 were recorded. Cabomba caroliniana was not previously recorded in the aquatic vegetation in Serbia. It is a popular aquarium plant native to South America (Brazil, Uruguay, Paraguay, and northeastern Argentina and, according to some authors, to southeastern United States. It was introduced into the rest of the USA, Canada, Australia, Asia (China, Malaysia, India, Japan, and in many regions of its new range it is considered an invasive and noxious aquatic weed. In Europe, it was found in the United Kingdom (introduced to England, Belgium, the Netherlands, and Hungary. Newly recorded populations in Serbia are restricted to the canals in Bačka. Populations are established only on two localities (Mali Stapar and Odžaci. [Projekat Ministarstva nauke Republike Srbije, br. III43002

  18. Study on the Characteristics of Alien Invasive Plants of Wetland in Yunnan%云南湿地外来入侵植物特征研究

    Institute of Scientific and Technical Information of China (English)

    杨忠兴; 陶晶; 郑进烜

    2014-01-01

    通过对云南湿地外来入侵植物的实地调查,确定云南湿地外来入侵植物共有70种,隶属于24科54属;来源于5大洲,其中来源于美洲的植物种类最多,共47种,占67.1%;入侵途径以人为传入为主,占95.7%。按水分生态类型分,以中生植物为主;按生活型分,以草本为主;按繁殖方式分,以种子繁殖为主,但以无性繁殖为主的入侵物种扩散速度快,危害性大。外来入侵植物在云南省16个地州(市)129个县(区)的湿地均有分布,其中全省范围分布的有43种,占61.5%。%Based on the field survey of invasive plant of wetland in Yunnan province , it was found out that there were 70 alien invasive plants belonging to 54 genera, 24 families.They originated from 5 continents, and 47 spe-cies (67.1%) were from the American Continent .The invasive route were mainly introduced by human , account-ing for 95.7 %, and most of alien invasive plants were hygrophytes according to water ecotype , and were herbs according to life-form and were seed propagation according to reproduction type .The alien invasive plants by asexual reproduction expanded very fast which caused higher damages .The alien invasive plants were widely distributed in the wetland of 129 counties of 16 prefectures or municipalities in Yunnan , among of which 43 species ( 61.5 %) were distributed in the whole province .

  19. Living with aliens: effects of invasive shrub honeysuckles on avian nesting.

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    Jason M Gleditsch

    Full Text Available Invasive species have come to the forefront of conservation biology as a major threat to native biodiversity. Habitats dominated by shrub honeysuckles (Lonicera spp. in the United States have been characterized as "ecological traps" by ecologists. Here we tested this hypothesis by investigating the effects of shrub honeysuckles on the nesting ecology of native birds in seven study sites in central Pennsylvania, USA. We examined how the abundance of shrub honeysuckles influenced the selection of nesting substrates and habitat for a community of common songbirds, and the parental-care behavior and nestling development of gray catbirds (Dumetella carolinensis. We found that birds had a strong bias towards nesting in honeysuckle shrubs, but not necessarily for nesting in honeysuckle-dominated habitats. Nest predation rates were affected by the density of nests in a habitat, but not by the overall abundance of honeysuckles in such habitats. Honeysuckle abundance in the habitat did show significant effects on some parental-care behavioral parameters: catbirds had higher nest visitation rates and shorter visit lengths in areas of high honeysuckle density. On average, Gray catbirds fed fruit 12%±0.31 s.e. of their nestling-feeding bouts, mostly fruits of shrub honeysuckles. Nestlings in sites with high honeysuckle density also showed higher mass:tarsus ratios, suggesting a good (possibly better physiological condition of catbird nestlings at the time of fledging. Our study shows that honeysuckle-dominated habitats could have equivocal effects on nesting parameters of common species of native birds. We advise more caution in the widespread denomination of novel plant communities with high densities of honeysuckle as "ecological traps" as effects can be null or positive on native birds in certain localities.

  20. APPROACHES ON THE INVASIVE ALIEN TAXA IN ROMANIA - AMBROSIA ARTEMISIIFOLIA (RAGWEED II

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    Nicoleta IANOVICI

    2011-01-01

    Full Text Available In a previous paper we presented the localities in Romania where we identified populations of Ambrosia artemisiifolia. Between 2008-2011, investigations were continuing. Our data clearly show that Ambrosia is present throughout the country. The territories heavily infested are railway embankments, along traffic routes, gravel pits, building sites, forest edges, industrial areas, cemeteries and recreational areas. It is quite common to find ragweed in many private gardens, or flower pots in urban areas. The few foci observed along riversides got there by household waste and construction waste. In many rural communities find it on the drainage ditches. Disturbed and neglected land (on city limits and outside the city, abandonment of land without subsequent turning of stubble and another wrong agricultural practice, absence of ruderal weed control are the main causes that favor the dissemination of our country. Intensity of anthropogenic influence is manifested mainly by transport of materials and soil movement during road rehabilitation and construction of highways. The recent observations show that could be expected to appear on agricultural fields, now being found only on the outskirts of cultivated land, at 5-6 meters from high traffic roads. Ambrosia benefits from human activities to spread. This implies a strong control strategy. The main objective of the fighting activities need to be to reduce damages caused by its pollen and to limit its expansion. If invasion by Ambrosia is left uncontrolled, increase of allergies could heavily augment the treatments. Knowledge about mechanical or chemical control of ragweed could be very important for road and rail services, agricultural institutions, farmers, staff responsible for managing natural areas, institutions that approves and oversees residential sites and factories, responsible personnel of the administrations from cities and rural localities. Reducing the population is more required than

  1. Preliminary results of studies on the distribution of invasive alien vascular plant species occurring in semi-natural and natural habitats in NW Poland

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    Popiela Agnieszka

    2015-03-01

    Full Text Available In Western Pomerania, as in other areas of Europe, alien species play an increasingly important role. In particular, invasive plants tend to spread rapidly and in large numbers which may reduce diversity of native species, leading to the phenomenon of “trivialisation of flora”, and transform ecosystems. The list of invasive species (32 taxa includes alien species occurring throughout Western Pomerania, and penetrating natural or semi-natural habitats. The second group consists of potentially invasive species (23 taxa, i.e. those distributed across the area under study and tending to increase the number of their localities in semi-natural and natural habitats, taxa invasive only locally, as well as species with missing data, which does not currently allow including them into the first group. Invasive weeds, as well as some epecophytes and archaeophytes occurring only on anthropogenic sites and tending to spread, were not taken into account. Among hemiagriophytes, the most common and troublesome ones are: Conyza canadensis, Erigeron annuus, Lolium multiflorum, Lupinus polyphyllus, Solidago canadensis, S. gigantea. Among holoagriophytes, i.e. the taxa which received the highest naturalisation status, very expansive species, successful in land colonisation, like Acer negundo, Bidens frondosa, B. connata, Clematis vitalba, Elodea canadensis, Epilobium ciliatum, Heracleum sosnowskyi, Impatiens glandulifera, I. parviflora, Padus serotina, Quercus rubra and Robinia pseudoacacia, should be given particular attention. Among the invasive and potentially invasive species, most taxa penetrate plant communities of the Artemisietea and Molinio-Arrhenatheretea class, followed by Querco-Fagetea, Vaccinio-Piceetea, Stellarietea mediae, Salicetea purpurae and Koelerio-Corynophoretea. The number of invasive species is twice as high when compared to the situation of these species in Poland; on the contrary, the number of species inhabiting anthropogenic, semi

  2. Study on Present Situation of Invasive Alien Species in Xinjiang%新疆外来入侵种现状研究

    Institute of Scientific and Technical Information of China (English)

    陈丽

    2012-01-01

    通过对我国新疆9种已呈现出较大危害的外来入侵种的分布范围、生境类型、种群建立状况、起源、首次发现或引入的地点及时间、来源、引入路径、入侵途径、经济和生态影响等内容进行了研究,并深入分析了目前外来入侵种管理等方面存在的问题,提出了外来入侵物种预防、控制和管理措施。%This paper researched distribution,habitat types,populations to establish the status,origin,the place and time found or introduced for the first time,introduction path,invasion pathways,economic and ecological impact and other aspects of nine kinds of invasive alien species which have shown a greater hazard in Xinjiang,analyzed the problems of alien invasive species management,and put forwards the prevention,control and management measures.

  3. Air-lubrication of magnetic disk sliders

    Science.gov (United States)

    Dreßler, B.; Graichen, K.; Bärwolff, G.; Jehring, L.; Seifert, G.

    1993-03-01

    Steady-state and dynamic flying of a self-acting magnetic disk slider over a hard disk are considered. Some tasks for computations are formulated and the possibilities of developed numerical codes are illustrated. Numerical results of dynamic flying over a disk surface with an obstacle are in agreement with experimental data.

  4. INVASIVENESS, CLONALITY AND HABITAT OF ALIEN INVASIVE PLANT IN VIRGINIA OF AMERICA%美国弗吉尼亚州入侵植物入侵性、克隆性和分布生境研究

    Institute of Scientific and Technical Information of China (English)

    肖赟君; 王宁; 周兵; 闫小红

    2014-01-01

    The invasiveness of alien invasive clonal plants might be affected by their clonality. The 109 alien invasive plants in Virginia of America were analyzed. The results showed that there are 59 invasive clonal plants (54.1%), whose mainly reproductive types were stolon and tiller. The percentage of the strongest invasiveness plants, the stronger invasiveness plants, the weaker invasiveness plants in all invasive plants are 30.3%, 44%and 25.7%, with clonal plants accounting for 48.5%, 56.3%, 57.1%respectively. Most of invasive plants were annual or biennial herbs, perennial herbs, shrub and vine, which belonged to Gramineae, Leguminosae and Compositae mainly. The majority of invasive plants distributed in adequate lighting and wet habitats. Data mentioned above indicated that clonality of the invasive plants in Virginia may be contributed significantly to their invasiveness, and most of invasive plants had strong ability of occupying habitat.%为了探讨入侵克隆植物入侵性与其克隆性之间的相关性,对美国弗吉尼亚州109种外来入侵植物进行了相关研究,结果表明:克隆植物有59种,占入侵植物总数的54.1%,且多数可通过根茎、分蘖等方式进行繁殖。入侵性最强的物种、较强的物种、较弱的物种分别占入侵植物总数的30.3%、44%、25.7%,其中克隆植物所占比例依次为:48.5%、56.3%和57.1%。上述入侵植物多为1~2年生草本、多年生草本、灌木和藤本类入侵植物,禾本科、豆科和菊科等科植物占据多数,多生长分布在光照充足、水分适宜的生境。上述结果表明,弗吉尼亚州入侵植物的克隆性可能促进了其入侵性,多数入侵植物具有较强的生境占据能力。

  5. 外来寄生虫入侵及其对土著宿主的影响%Invasion of Alien Parasites and Its Impacts on Native Hosts

    Institute of Scientific and Technical Information of China (English)

    孔萌萌; 李文祥

    2016-01-01

    Biological invasion is a major threat to native species and biodiversity.Invasive parasites are introduced with the alien hosts and also considered as invasive species.In this paper,parasites invading processes including species introduction,population establishment and host switching were summarized by analyzing invasion cases of exotic parasites.Generally,the invasive parasites were more virulent in native hosts than in the co-introduced alien host.Some invasive parasites resulted in direct or indirect death of native hosts and some species decreased repro-duction ability of native hosts populations,consequently decreasing community diversity of native hosts.We also discussed the control and management of parasite invasion according to the invasive process of parasites:firstly,to avoid translocation of parasites with the introduction of hosts by taking early warning measures,including transporta-tion management and introduced species management ;then,to prevent establishment of parasite population by e-radicating reservoir hosts,controlling vectors,vaccinating susceptible hosts and implementing habitat management;finally,to take mitigation measures such as managing native host and vector population,cutting off corridors to limit further invasive spread.%生物入侵严重威胁着土著物种和生物多样性,外来物种带来的寄生虫入侵问题也应该引起相应的重视。结合外来寄生虫的入侵案例,阐述了寄生虫的引入、种群建立和宿主转移等入侵过程。通常寄生虫入侵后,致病力会变得更大,有些会直接引起土著宿主的死亡,有些间接引起宿主死亡,有的则引起繁殖力下降,从而降低土著宿主的群落多样性,讨论了寄生虫入侵的管理和控制。

  6. 外来入侵豚草综合治理研究进展%Cai-taiAdvances in Integrated Control of Invasive Alien Plant Ambrosia artemisiifolia

    Institute of Scientific and Technical Information of China (English)

    王娟; 邓旭; 谭济才

    2011-01-01

    Ambrosia is a kind of invasive alien weed, whose invasion not only threatens native biodiversity and ecosystems, but also causes considerable economic loss. In order to control the damage of Ambrosia effectively, on the basis of introducing mechanical, chemical and biological control methods, the insufficiencies of them were clarified and an integrated control measure was proposed.%豚草属(Ambrosia)是一种外来恶性杂草,它的入侵不仅威胁了当地生物多样性和生态系统,还导致巨大的经济损失.为有效控制其危害,在介绍豚草人工、化学、生物控制方法的基础上,针对各种方法不足之处.提出了综合控制措施.

  7. 外来物种入侵的刑事控制模式%On Criminal Control Pattern of Invasive Alien Species

    Institute of Scientific and Technical Information of China (English)

    王振

    2013-01-01

    Invasive alien species has been becoming a risking factor that is very harmful to the ecological security besides lives and health of human being, so it is necessary to regulating the invasive alien species in criminal law.Analyzing the protecting ways of the legal interests of environment in criminal law, we should take the potential damage offense and the indeed damage offense together into account in criminal legislation.At the same time, it is right rout to introducing the epidemiology causality, based on probability theory and the statistical science to settling the mazy problem of the causality of criminal law about eco-crimes.%物种入侵正日益成为危害人类生命健康、生态环境安全的又一风险因素;对物种入侵行为的刑法规制的犯罪构成模式设计是危险犯与实害犯并用;建立在统计科学概率论基础上的疫学因果关系是破解生态犯罪刑法因果关系的合理选择.

  8. Alien invasive species and biological pollution of the Great Lakes Basin ecosystem[Great Lakes Water Quality Board : Report to the International Joint Commission

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-05-01

    The displacement of important native species in the Great Lakes is a result of an invasion by a succession of non indigenous aquatic species. These invasion also resulted in interference with the proper human water uses and cost billions of dollars. The problem was considered serious enough that the International Joint Commission asked the Great Lakes Water Quality Board in 1999 to review the regulations in place and make recommendations, if necessary, for the implementation of additional measures that could be considered to keep control over the introduction of alien invasive species. Escapes from aquaria, aquaculture, research and educational facilities, canal and diversion water flows, and release of live bait are all sources of this invasion. The effectiveness of alternative technologies to control the invasion was to be examined by the Board. Other efforts taking place to address the situation in the basin are being complemented by the publication of this report. It is considered that the most important source of alien invasive species (AIS) to the Great Lakes is the discharge of ballast water from shipping vessels coming from outside the United States and Canada. A major concern is the role played by vessels reporting no ballast on board (NOBOB) upon entering the basin. A number of recommendations were made concerning: (1) implementation and enforcement of the ballast water discharge standards agreed upon by both countries, (2) the evaluation of the effectiveness of alternative technologies to achieve ballast water discharge standards over the long term, combined with the use of chemical treatment while the evaluation is being performed, (3) the implementation of optimal management practices to control sediments in shipping vessels, (4) modifications to the design of shipping vessels, and (5) the monitoring and contingency plans in the event of a repeat scenario in the future. Composed of an equal number representatives from the United States and Canada, at

  9. Do David and Goliath Play the Same Game? Explanation of the Abundance of Rare and Frequent Invasive Alien Plants in Urban Woodlands in Warsaw, Poland

    Science.gov (United States)

    Mędrzycki, Piotr; Kołaczkowska, Ewa; Ciurzycki, Wojciech; Marciszewska, Katarzyna

    2016-01-01

    Invasive Alien Plants occur in numbers differing by orders of magnitude at subsequent invasion stages. Effective sampling and quantifying niches of rare invasive plants are quite problematic. The aim of this paper is an estimation of the influence of invasive plants frequency on the explanation of their local abundance. We attempted to achieve it through: (1) assessment of occurrence of self-regenerating invasive plants in urban woodlands, (2) comparison of Random Forest modelling results for frequent and rare species. We hypothesized that the abundance of frequent species would be explained better than that of rare ones and that both rare and frequent species share a common hierarchy of the most important determinants. We found 15 taxa in almost two thirds of 1040 plots with a total number of 1068 occurrences. There were recorded 6 taxa of high frequency–Prunus serotina, Quercus rubra, Acer negundo, Robinia pseudoacacia, Impatiens parviflora and Solidago spp.–and 9 taxa of low frequency: Acer saccharinum, Amelanchier spicata, Cornus spp., Fraxinus spp., Parthenocissus spp., Syringa vulgaris, Echinocystis lobata, Helianthus tuberosus, Reynoutria spp. Random Forest’s models’ quality grows with the number of occurrences of frequent taxa but not of the rare ones. Both frequent and rare taxa share a similar hierarchy of predictors’ importance: Land use > Tree stand > Seed source and, for frequent taxa, Forest properties as well. We conclude that there is an ‘explanation jump’ at higher species frequencies, but rare species are surprisingly similar to frequent ones in their determinant’s hierarchy, with differences conforming with their respective stages of invasion. PMID:27992516

  10. A Legislative Research on Prevention and Control of Alien Species Invasion%我国外来物种入侵防治立法研究

    Institute of Scientific and Technical Information of China (English)

    鲁继平

    2015-01-01

    To reverse the grave situation of alien species invasion in China, we should make a legislative research on prevention and control of the invasion. It will help transform some effective rules and measures into legal norms, thus promoting the administrative work according to law in this respect. One of the most effective measures to control invasion of alien species is to formulate Law on Prevention and Control of Alien Species Invasion (hereafter referred to as the Law). It is not only an important initiative to implement the relevant documents issued by the Party Central Committee and the State Council but also a necessary requirement of sustainable development. Chinese government is now paying high attention to the prevention and control of alien species invasion. In view of our plenty practices and other countries ' experiences, we should as soon as possible enact the Law on the basis of the existing law and regulations. The author suggest the Law be composed of General Provisions, Foreword, Survey, Prevention & Control, Supervision & Administration, Legal Liabilities and Supplementary Provisions. In the Legal Liabilities not only administrative and criminal liabilities should be stipulated, feasible civil liabilities should also be clearly defined.%开展外来物种入侵防治立法不仅有利于扭转我国外来物种入侵防治的严峻形势, 而且也有利于将许多行之有效的制度和措施上升为法律规范,从而有力地促进我国外来物种入侵防治工作的依法开展和依法行政. 制定外来物种入侵防治法是落实党中央、国务院有关文件要求的重要举措,是实施可持续发展战略的必然要求,是防治外来物种入侵最有效的手段之一. 目前,我国对外来物种入侵防治工作高度重视,已积累了丰富的实践经验,同时又有可供参考、借鉴的国外立法经验. 因此,应在充分考虑现行法律规范的基础上,尽快制定出台我国外来物种入侵防治法,

  11. 广西北部湾经济区外来入侵植物%The Alien Invasive Phmts in Guangxi Beibu Gulf Economic Zone

    Institute of Scientific and Technical Information of China (English)

    林建勇; 温远光; 韦洁

    2011-01-01

    根据野外调查和相关资料整理,初步探讨了广西北部湾经济区外来入侵植物的种类组成、原产地、引入途径、生境类型、分布情况和危害程度。结果表明:该区现有外来入侵植物31科69属87种,种数最多的有菊科(Compositae)和禾本科(Gramineae),其中来源于美洲的种类最多,有67种,占总种数77.9%。危害状况严重的有15种,危害中等的有30种,危害较轻的有41种。保护本地生态系统、建立外来入侵物种监测机制和风险评价体系将是防范外来入侵植物的有效途径。%According to field investigation and related materials, the species, place of origin, introducing approaches, habitats, distribution and harmfulness of alien invasive plants in Guangxi Beibu Gulf Economic Zone were discussed. The results showed that 87 species of alien invasive plants belonging to 69 genera and 31 families were identified, most of Compositae and Gramineae. Constitutional analysis of the original locality revealed that 67 species were from Tropical America which took up 77.9 % of the total species. And 15 species were ,evaluated to be at the high degree of threat to the local biodiversity, 30 at the medium, and 41 at the low. The most effective strategies were to protect native ecosystem and to establish monitor mechanism and risk assessment system of alien invasive plants.

  12. Changes in defense of an alien plant Ambrosia artemisiifolia before and after the invasion of a native specialist enemy Ophraella communa.

    Directory of Open Access Journals (Sweden)

    Yuya Fukano

    Full Text Available The evolution of increased competitive ability hypothesis (EICA predicts that when alien plants are free from their natural enemies they evolve lower allocation to defense in order to achieve a higher growth rate. If this hypothesis is true, the converse implication would be that the defense against herbivory could be restored if a natural enemy also becomes present in the introduced range. We tested this scenario in the case of Ambrosia artemisiifolia (common ragweed - a species that invaded Japan from North America. We collected seeds from five North American populations, three populations in enemy free areas of Japan and four populations in Japan where the specialist herbivore Ophraella communa naturalized recently. Using plants grown in a common garden in Japan, we compared performance of O. communa with a bioassay experiment. Consistent with the EICA hypothesis, invasive Japanese populations of A. artemisiifolia exhibited a weakened defense against the specialist herbivores and higher growth rate than native populations. Conversely, in locations where the herbivore O. communa appeared during the past decade, populations of A. artemisiifolia exhibited stronger defensive capabilities. These results strengthen the case for EICA and suggest that defense levels of alien populations can be recuperated rapidly after the native specialist becomes present in the introduced range. Our study implies that the plant defense is evolutionary labile depending on plant-herbivore interactions.

  13. DNA-based identification of invasive alien species in relation to Canadian federal policy and law, and the basis of rapid-response management.

    Science.gov (United States)

    Thomas, Vernon G; Hanner, Robert H; Borisenko, Alex V

    2016-11-01

    Managing invasive alien species in Canada requires reliable taxonomic identification as the basis of rapid-response management. This can be challenging, especially when organisms are small and lack morphological diagnostic features. DNA-based techniques, such as DNA barcoding, offer a reliable, rapid, and inexpensive toolkit for taxonomic identification of individual or bulk samples, forensic remains, and even environmental DNA. Well suited for this requirement, they could be more broadly deployed and incorporated into the operating policy and practices of Canadian federal departments and should be authorized under these agencies' articles of law. These include Fisheries and Oceans Canada, Canadian Food Inspection Agency, Transport Canada, Environment Canada, Parks Canada, and Health Canada. These efforts should be harmonized with the appropriate provisions of provincial jurisdictions, for example, the Ontario Invasive Species Act. This approach necessitates that a network of accredited, certified laboratories exists, and that updated DNA reference libraries are readily accessible. Harmonizing this approach is vital among Canadian federal agencies, and between the federal and provincial levels of government. Canadian policy and law must also be harmonized with that of the USA when detecting, and responding to, invasive species in contiguous lands and waters. Creating capacity in legislation for use of DNA-based identifications brings the authority to fund, train, deploy, and certify staff, and to refine further developments in this molecular technology.

  14. Colonization history, host distribution, anthropogenic influence and landscape features shape populations of white pine blister rust, an invasive alien tree pathogen.

    Directory of Open Access Journals (Sweden)

    Simren Brar

    Full Text Available White pine blister rust is caused by the fungal pathogen Cronartium ribicola J.C. Fisch (Basidiomycota, Pucciniales. This invasive alien pathogen was introduced into North America at the beginning of the 20th century on pine seedlings imported from Europe and has caused serious economic and ecological impacts. In this study, we applied a population and landscape genetics approach to understand the patterns of introduction and colonization as well as population structure and migration of C. ribicola. We characterized 1,292 samples of C. ribicola from 66 geographic locations in North America using single nucleotide polymorphisms (SNPs and evaluated the effect of landscape features, host distribution, and colonization history on the structure of these pathogen populations. We identified eastern and western genetic populations in North America that are strongly differentiated. Genetic diversity is two to five times higher in eastern populations than in western ones, which can be explained by the repeated accidental introductions of the pathogen into northeastern North America compared with a single documented introduction into western North America. These distinct genetic populations are maintained by a barrier to gene flow that corresponds to a region where host connectivity is interrupted. Furthermore, additional cryptic spatial differentiation was identified in western populations. This differentiation corresponds to landscape features, such as mountain ranges, and also to host connectivity. We also detected genetic differentiation between the pathogen populations in natural stands and plantations, an indication that anthropogenic movement of this pathogen still takes place. These results highlight the importance of monitoring this invasive alien tree pathogen to prevent admixture of eastern and western populations where different pathogen races occur.

  15. Colonization History, Host Distribution, Anthropogenic Influence and Landscape Features Shape Populations of White Pine Blister Rust, an Invasive Alien Tree Pathogen

    Science.gov (United States)

    Brar, Simren; Tsui, Clement K. M.; Dhillon, Braham; Bergeron, Marie-Josée; Joly, David L.; Zambino, P. J.; El-Kassaby, Yousry A.; Hamelin, Richard C.

    2015-01-01

    White pine blister rust is caused by the fungal pathogen Cronartium ribicola J.C. Fisch (Basidiomycota, Pucciniales). This invasive alien pathogen was introduced into North America at the beginning of the 20th century on pine seedlings imported from Europe and has caused serious economic and ecological impacts. In this study, we applied a population and landscape genetics approach to understand the patterns of introduction and colonization as well as population structure and migration of C. ribicola. We characterized 1,292 samples of C. ribicola from 66 geographic locations in North America using single nucleotide polymorphisms (SNPs) and evaluated the effect of landscape features, host distribution, and colonization history on the structure of these pathogen populations. We identified eastern and western genetic populations in North America that are strongly differentiated. Genetic diversity is two to five times higher in eastern populations than in western ones, which can be explained by the repeated accidental introductions of the pathogen into northeastern North America compared with a single documented introduction into western North America. These distinct genetic populations are maintained by a barrier to gene flow that corresponds to a region where host connectivity is interrupted. Furthermore, additional cryptic spatial differentiation was identified in western populations. This differentiation corresponds to landscape features, such as mountain ranges, and also to host connectivity. We also detected genetic differentiation between the pathogen populations in natural stands and plantations, an indication that anthropogenic movement of this pathogen still takes place. These results highlight the importance of monitoring this invasive alien tree pathogen to prevent admixture of eastern and western populations where different pathogen races occur. PMID:26010250

  16. Discussion On the Civil Liability of Alien Species Invasion%外来物种入侵的民事责任构成之探讨

    Institute of Scientific and Technical Information of China (English)

    童光法; 佟占军

    2012-01-01

    经过许可的有意引种行为和无意引种行为,引种人不需要承担民事责任;此时应当设立国家外来物种入侵防治基金.在未经许可的有意引种行为,适用一般侵权行为的过错归责原则,即适用《侵权责任法》第6条而不适用第65条的规定;基于已建立的国家引种许可证制度和相应的数据库,来认定该未经许可的引种行为具有违法性;在因果关系证明上,原告方只需就责任成立的因果关系进行证明.%Under the authorization of introduction of alien species or any unintentional introduction, a person shouldn't bear civil liability for the damages when the action leads to invasion. Under this circumstance, the state should advocate establishment of environmental fund for preventing and controlling alien species invasion. Without any permission, a person should bear fault liability according to the article 6 (not article 65) of Tort Liability Act. Based on the licensing system, list system and the corresponding database, we hold the wrongfulness of the unauthorized actions. The plaintiff shouldn't prove the legal cause but the cause in fact.

  17. Composition and distribution of invasive alien plants in Suzhou area%苏州地区外来入侵植物组成及分布

    Institute of Scientific and Technical Information of China (English)

    林敏; 郝建华; 陈国奇

    2012-01-01

    为了解苏州外来入侵植物的种类组成及分布概况,对苏州地区6个县市(包括常熟、昆山、苏州、太仓、吴江和张家港)26个样点内不同生境中的外来入侵植物进行了调查分析.调查结果显示:每个样点有外来人侵植物7~25种,平均每个样点有17.9种.在26个样点中观察到外来入侵植物57种,隶属于19科45属;其中菊科(Compositae)种类最多(23种),占总种数的40.4%;豆科(Leguminosae)、玄参科(Scrophulariaceae)、禾本科(Poaceae)、伞形科(Apiaceae)、苋科(Amaranthaceae)和旋花科(Convolvulaceae)种类也较多.原产于北美洲和欧洲的种类分别有20和12种,分别占总种数的35.1%和21.0%;还有17种原产于美洲的其他区域,少数种类原产于非洲、西亚和地中海地区.在57种外来入侵植物中,草本植物有55种,非多年生植物有44种,分别占总种数的96.5%和77.2%.有18种的频度超过50%,其中加拿大一枝黄花(Solidago canadensis L.)和一年蓬[Erigeron annuus (L.) Pers.]的频度最高,分别达到96.15%和92.31%,且多度等级均属于极多级(Soc);空心莲子草[ Ahernanthera philoxeroides( Mart.) Griseb.]和白车轴草(Trifolium repens L.)的频度也均在80%以上,且多度等级也属于极多级(Soc).调查结果表明:苏州地区外来植物入侵现象比较严重.%In order to understand species composition and distribution of invasive alien plants in Suzhou, invasive alien plants in different habitats of 26 sample plots in six counties or cities (including Changshu, Kunshan, Suzhou, Taicang, Wujiang and Zhangjiagang) of Suzhou area were investigated and analyzed. The investigation results show that there are 7-25 species of invasive alien plants in these plots with the average of 17. 9 species per plot. There are 57 species of invasive alien plants observed in 26 sample plots, belonging to 45 genera in 19 families. In which, species number in Compositae (23 species) is the most

  18. Removal of nonnative slider turtles (Trachemys scripta) and effects on native Sonora mud turtles (Kinosternon sonoriense) at Montezuma Well, Yavapai County, Arizona

    Science.gov (United States)

    Drost, Charles A.; Lovich, Jeffrey E.; Madrak, Sheila V.; Monatesti, A.J.

    2011-01-01

    The National Park Service (NPS) estimates that 234 national parks contain nonnative, invasive animal species that are of management concern (National Park Service, 2004). Understanding and controlling invasive species is thus an important priority within the NPS (National Park Service, 1996). The slider turtle (Trachemys scripta) is one such invasive species. Native to the Southeastern United States (Ernst and Lovich, 2009), as well as Mexico, Central America, and portions of South America (Ernst and Barbour, 1989), the slider turtle has become established throughout the continental United States and in other locations around the world (Burke and others, 2000). Slider turtle introductions have been suspected to be a threat to native turtles (Holland 1994; da Silva and Blasco, 1995), however, there has not been serious study of their effects until recently. Cadi and Joly (2003) found that slider turtles outcompeted European pond turtles (Emys orbicularis) for preferred basking sites under controlled experimental conditions, demonstrating for the first time direct competition for resources between a native and an exotic turtle species. Similarly, Spinks and others (2003) suggested that competition for basking sites between slider turtles and Pacific pond turtles (Actinemys marmorata) was partly responsible for the decline of Pacific pond turtles observed at their study site in California. They concluded that the impact of introduced slider turtles was 'almost certainly negative' for the western pond turtle. In the most recent critical study to assess the effects of introduced slider turtles on native turtles, Cadi and Joly (2004) demonstrated that European pond turtles that were kept under experimentally controlled conditions with slider turtles lost body weight and exhibited higher rates of mortality than in control groups of turtles comprised of the same species, demonstrating potential population-level effects on native species. Slider turtles are not native to

  19. Survivorship and feeding preferences among size classes of outplanted sea urchins, Tripneustes gratilla, and possible use as biocontrol for invasive alien algae

    Science.gov (United States)

    Ringang, Rory R.; Cantero, Sean Michael A.; Toonen, Robert J.

    2015-01-01

    We investigate the survivorship, growth and diet preferences of hatchery-raised juvenile urchins, Tripneustes gratilla, to evaluate the efficacy of their use as biocontrol agents in the efforts to reduce alien invasive algae. In flow-through tanks, we measured urchin growth rates, feeding rates and feeding preferences among diets of the most common invasive algae found in Kāneʻohe Bay, Hawaiʻi: Acanthophora spicifera, Gracilaria salicornia, Eucheuma denticulatum and Kappaphycus clade B. Post-transport survivorship of outplanted urchins was measured in paired open and closed cages in three different reef environments (lagoon, reef flat and reef slope) for a month. Survivorship in closed cages was highest on the reef flat (∼75%), and intermediate in the lagoon and reef slope (∼50%). In contrast, open cages showed similar survivorship on the reef flat and in the lagoon, but only 20% of juvenile urchins survived in open cages placed on the reef slope. Urchins grew significantly faster on diets of G. salicornia (1.58 mm/week ± 0.14 SE) and Kappaphycus clade B (1.69 ± 0.14 mm/wk) than on E. denticulatum (0.97 ± 0.14 mm/wk), with intermediate growth when fed on A. spicifera (1.23 ± 0.11 mm/wk). Interestingly, urchins display size-specific feeding preferences. In non-choice feeding trials, small urchins (17.5–22.5 mm test diameter) consumed G. salicornia fastest (6.08 g/day ± 0.19 SE), with A. spicifera (4.25 ± 0.02 g/day) and Kappaphycus clade B (3.83 ± 0.02 g/day) intermediate, and E. denticulatum was clearly the least consumed (2.32 ± 0.37 g/day). Medium-sized (29.8–43.8 mm) urchins likewise preferentially consumed G. salicornia (12.60 ± 0.08 g/day), with less clear differences among the other species in which E. denticulatum was still consumed least (9.35 ± 0.90 g/day). In contrast, large urchins (45.0–65.0 mm) showed no significant preferences among the different algae species at all (12.43–15.24 g/day). Overall consumption rates in non

  20. Survivorship and feeding preferences among size classes of outplanted sea urchins, Tripneustes gratilla, and possible use as biocontrol for invasive alien algae.

    Science.gov (United States)

    Westbrook, Charley E; Ringang, Rory R; Cantero, Sean Michael A; Toonen, Robert J

    2015-01-01

    We investigate the survivorship, growth and diet preferences of hatchery-raised juvenile urchins, Tripneustes gratilla, to evaluate the efficacy of their use as biocontrol agents in the efforts to reduce alien invasive algae. In flow-through tanks, we measured urchin growth rates, feeding rates and feeding preferences among diets of the most common invasive algae found in Kāne'ohe Bay, Hawai'i: Acanthophora spicifera, Gracilaria salicornia, Eucheuma denticulatum and Kappaphycus clade B. Post-transport survivorship of outplanted urchins was measured in paired open and closed cages in three different reef environments (lagoon, reef flat and reef slope) for a month. Survivorship in closed cages was highest on the reef flat (∼75%), and intermediate in the lagoon and reef slope (∼50%). In contrast, open cages showed similar survivorship on the reef flat and in the lagoon, but only 20% of juvenile urchins survived in open cages placed on the reef slope. Urchins grew significantly faster on diets of G. salicornia (1.58 mm/week ± 0.14 SE) and Kappaphycus clade B (1.69 ± 0.14 mm/wk) than on E. denticulatum (0.97 ± 0.14 mm/wk), with intermediate growth when fed on A. spicifera (1.23 ± 0.11 mm/wk). Interestingly, urchins display size-specific feeding preferences. In non-choice feeding trials, small urchins (17.5-22.5 mm test diameter) consumed G. salicornia fastest (6.08 g/day ± 0.19 SE), with A. spicifera (4.25 ± 0.02 g/day) and Kappaphycus clade B (3.83 ± 0.02 g/day) intermediate, and E. denticulatum was clearly the least consumed (2.32 ± 0.37 g/day). Medium-sized (29.8-43.8 mm) urchins likewise preferentially consumed G. salicornia (12.60 ± 0.08 g/day), with less clear differences among the other species in which E. denticulatum was still consumed least (9.35 ± 0.90 g/day). In contrast, large urchins (45.0-65.0 mm) showed no significant preferences among the different algae species at all (12.43-15.24 g/day). Overall consumption rates in non-choice trials

  1. Survivorship and feeding preferences among size classes of outplanted sea urchins, Tripneustes gratilla, and possible use as biocontrol for invasive alien algae

    Directory of Open Access Journals (Sweden)

    Charley E. Westbrook

    2015-09-01

    Full Text Available We investigate the survivorship, growth and diet preferences of hatchery-raised juvenile urchins, Tripneustes gratilla, to evaluate the efficacy of their use as biocontrol agents in the efforts to reduce alien invasive algae. In flow-through tanks, we measured urchin growth rates, feeding rates and feeding preferences among diets of the most common invasive algae found in Kāneʻohe Bay, Hawaiʻi: Acanthophora spicifera, Gracilaria salicornia, Eucheuma denticulatum and Kappaphycus clade B. Post-transport survivorship of outplanted urchins was measured in paired open and closed cages in three different reef environments (lagoon, reef flat and reef slope for a month. Survivorship in closed cages was highest on the reef flat (∼75%, and intermediate in the lagoon and reef slope (∼50%. In contrast, open cages showed similar survivorship on the reef flat and in the lagoon, but only 20% of juvenile urchins survived in open cages placed on the reef slope. Urchins grew significantly faster on diets of G. salicornia (1.58 mm/week ± 0.14 SE and Kappaphycus clade B (1.69 ± 0.14 mm/wk than on E. denticulatum (0.97 ± 0.14 mm/wk, with intermediate growth when fed on A. spicifera (1.23 ± 0.11 mm/wk. Interestingly, urchins display size-specific feeding preferences. In non-choice feeding trials, small urchins (17.5–22.5 mm test diameter consumed G. salicornia fastest (6.08 g/day ± 0.19 SE, with A. spicifera (4.25 ± 0.02 g/day and Kappaphycus clade B (3.83 ± 0.02 g/day intermediate, and E. denticulatum was clearly the least consumed (2.32 ± 0.37 g/day. Medium-sized (29.8–43.8 mm urchins likewise preferentially consumed G. salicornia (12.60 ± 0.08 g/day, with less clear differences among the other species in which E. denticulatum was still consumed least (9.35 ± 0.90 g/day. In contrast, large urchins (45.0–65.0 mm showed no significant preferences among the different algae species at all (12.43–15.24 g/day. Overall consumption rates in non

  2. Competitive replacement of the native Vitis and Hedera taxa by invasive aliens: morphological, cytological and molecular evidences

    Directory of Open Access Journals (Sweden)

    Maria HOHN

    2012-10-01

    Full Text Available We describe here case studies of two woody climber species native to the broadleaf forests of the Carpathian basin. Wild grape (Vitis sylvestris C.C.Gmel., considered to be one of the ancestors of the domesticated grapevine (Vitis vinifera L. became a highly threatened species since the introduction of the American grape species as rootstocks for grapevine. Among these, especially, Riparian grape (Vitis riparia Minchx. escaped from the wine yards and by invading the natural habitats replaced the autochthonous wild grape. In consequence of the competitive exclusion Vitis sylvestris suffered a strong withdrawal along its native habitats. 20 morphological traits, including leaf shape and trichome structure were studied to tackle evidence of the introgressive hybridization among the alien and native taxa. Most of the studied Hungarian habitats were already dominated by hybrid specimens of Vitis taxa. Molecular analysis based on 8 nuclear microsatellites markers supported the morphological results. 

  3. ALIEN SPECIES: THEIR ROLE IN AMPHIBIAN POPULATION DECLINES AND RESTORATION

    Science.gov (United States)

    Alien species (also referred to as exotic, invasive, introduced, or normative species) have been implicated as causal agents in population declines of many amphibian species. Herein, we evaluate the relative contributions of alien species and other factors in adversely affecting ...

  4. Alien Pathogens on the Horizon

    NARCIS (Netherlands)

    Roy, Helen E.; Hesketh, Helen; Purse, Bethan V.; Eilenberg, Jørgen; Santini, Alberto; Scalera, Riccardo; Stentiford, Grant D.; Adriaens, Tim; Bacela-Spychalska, Karolina; Bass, David; Beckmann, Katie M.; Bessell, Paul; Bojko, Jamie; Booy, Olaf; Cardoso, Ana Cristina; Essl, Franz; Groom, Quentin; Harrower, Colin; Kleespies, Regina; Martinou, Angeliki F.; Oers, van Monique M.; Peeler, Edmund J.; Pergl, Jan; Rabitsch, Wolfgang; Roques, Alain; Schaffner, Francis; Schindler, Stefan; Schmidt, Benedikt R.; Schönrogge, Karsten; Smith, Jonathan; Solarz, Wojciech; Stewart, Alan; Stroo, Arjan; Tricarico, Elena; Turvey, Katharine M.A.; Vannini, Andrea; Vilà, Montserrat; Woodward, Stephen; Wynns, Anja Amtoft; Dunn, Alison M.

    2016-01-01

    According to the Convention on Biological Diversity, by 2020 invasive alien species (IAS) should be identified and their impacts assessed, so that species can be prioritized for implementation of appropriate control strategies and measures put in place to manage invasion pathways. For one quarter of

  5. Strategy to control the invasive alien tree Miconia calvescens in Pacific islands: Eradication, containment or something else?

    Science.gov (United States)

    Meyer, Jean-Yves; Loope, Lloyd; Goarant, Anne-Claire; Veitch, C.R.; Clout, M.N.; Towns, D. R.

    2011-01-01

    Miconia calvescens (Melastomataceae) is a notorious plant invader in the tropical islands of French Polynesia, Hawaii and New Caledonia. A small tree native to Central and South America, it was first introduced as an ornamental in private botanic gardens in Tahiti (1937), Honolulu (1961), and Nouméa (1970s) where it escaped, became naturalised, and formed dense monospecific stands. More than 80,000 ha are currently invaded in French Polynesia, 10,000 ha in the Hawaiian Islands and 140 ha in New Caledonia. Control programmes have been under way in the Hawaiian Islands (Oahu, Maui, Hawaii, Kauai) and French Polynesia (Raiatea, Tahaa, Nuku Hiva, Fatu Hiva) since the early 1990s, and in New Caledonia (Province Sud) since 2006. Despite more than 15 years of intensive control efforts and millions of plants destroyed, eradication has not been achieved in any of these islands, mainly because the species has multiple features that thwart its elimination (e.g., prolific seed production, active dispersal by alien and native frugivorous birds, large and persistent soil seed bank, shade-tolerance), combined with the difficulty of detecting and destroying plants on rough terrain and steep slopes, insufficient control frequency, and limited financial and human resources. Miconia’s life cycle requires at least four years growth from seedling to fruiting. Consequently, prevention of fruit production may be an effective management strategy for small populations. This “juvenilization” process may allow the eradication of small populations when carefully conducted over a quarter century. 

  6. Effect of friction on the performance of inertial slider

    Indian Academy of Sciences (India)

    K Anantheshwara; N S Murali; M S Bobji

    2008-06-01

    Inertial sliders are friction based drives used to position with a resolution of a few hundred of nanometers to over a range of few millimeters. The compactness and simple construction enabled it to be used as a coarse positioner in various Scanning Probe Microscopes (SPM). Even heavy masses has been thought off earlier to use the inertial slider to position precisely, lack of understanding in the dynamical friction behaviour has been the main reason why the inertial sliders potential has not been explored fully in any practical device. In this paper, we have studied the effect of different operating parameters on the step size of the slider. The inertial mass is kept on three sapphire balls, which are attached to shear piezoelectric material. The behaviour of inertial mass was studied for different input waveforms and different surface conditions that come in contact with the sapphire balls. It was observed that under lubricated conditions the step size was reduced.

  7. Genomic signature and cluster analysis of genetic diversity of alien invasive species%外来入侵物种的基因签名及其遗传多样性聚类分析

    Institute of Scientific and Technical Information of China (English)

    谈承杰; 朱平

    2013-01-01

      密码子的使用频率分布能够反映一定的生物特性,因而可作为一种基因签名。本文使用CGR方法来研究外来入侵物种不同组织序列的基因签名及遗传多样性聚类分析,首先得出了刺花莲子草(Alternanthera pungens),紫茎泽兰(Ageratina adenophora),水葫芦(Eichhornia crassipes),微甘菊(Mikania micrantha),土荆芥(Chenopodium ambrosioides),一枝黄花(Solidago canadensis)等6种外来入侵植物的31条序列核苷酸字串长k=1到k=6的情况,并选取k=3,即基因序列的密码子,作为生物特性的一个重要表达。并且构造序列间的CGR欧式距离,进而对外来入侵植物序列遗传多样性进行了聚类分析。通过对所获得的6种外来入侵植物的31条序列的基因签名,得出如下结果:CGR是一种简便且计算量小的方法,且基于CGR方法的基因签名,具有典型的生物特性;入侵植物的基因序列在密码子的使用上是非均衡的,且物种亲缘关系近的,则基因签名相似越高;而且基因签名也揭示出了密码子的第三位碱基偏好使用碱基T的现象,与一般物种密码子第三位碱基偏好G/C情况有强烈反差。此外,从获得的6个物种的31条序列聚类谱系图可以直观看出,入侵植物间存在着一定的亲缘关系,遗传多样性较丰富。由于我们所建立的基于CGR方法的基因签名,不仅能够反映植物特性和进化关系,而且能揭示序列中密码子和碱基的偏好使用情况,因而该方法有利于对外来入侵物种的遗传多样性分析、风险评估及预防控制等提供科学依据。%Alien invasive species had been a global eco-environmental problem, resulting in huge economic loss. The distribution of codon usage could reflect some biological characteristics, therefore it could be a genomic signature. The paper proposed a genomic signature-based approach, using CGR with word length of k=3, which

  8. 梅州城市湿地外来入侵植物现状及防治对策%Alien Invasive Plants and Their Control in Urban Wetlands of Meizhou

    Institute of Scientific and Technical Information of China (English)

    曾兰华; 杨礼文; 俞万源; 李海山; 欧先交

    2013-01-01

    通过实地调查和文献检索,对梅州城市湿地外来入侵植物的组成、生活型、危害程度、原产地、入侵途径等进行了分析。结果表明:梅州城市湿地主要外来入侵植物有16科29属33种,其中菊科植物的数量最多,占入侵植物总数的27.3%;生活型以草本植物为主;有10种入侵植物给当地生态环境带来严重危害;原产地以美洲为主;引入途径主要以人为有意或无意引入为主。在分析城市湿地外来入侵植物现状的基础上,提出了建立入侵植物生态风险评估系统、加强入境检疫、加强地区合作、提高公众防范意识、有效防控和变害为宝等对策,为城市生态及经济的可持续发展提供参考。%The composition, life forms, damage degrees, original districts and invasive routes of alien invasive plant species in urban wetlands of Meizhou City are analyzed in this paper based on our field survey and literature review. The results show that 33 species from 16 families and 29 genera of alien invasive plant species are distributed in the urban wetlands of Meizhou. The Asteraceous plants are the most in number and take up 27.3%of the total species. Herbaceous plant is the dominant life form. In addition, there are 10 species that have caused high degree of threat to the local ecological environment. Most of the alien invasive plant species originally were from the Americas and were introduced intentionally or unintentionally by human beings. On the basis of the research, the strategies for controlling the alien invasive plants are proposed, such as establishing ecological risk evaluating system, enhancing entry quarantine, enhancing regional cooperation, increasing public awareness, effectively preventing and controlling the alien invasive plants, and transforming harmful plants into useful ones, etc. The results of this paper will provide reference for sustainable development of urban ecology and economy of the

  9. Survey and documentation of the potential and actual invasive alien plant species and other biological threats to biodiversity in Awash National Park, Ethiopia

    Directory of Open Access Journals (Sweden)

    Sebsebe DEMISSEW

    2011-01-01

    Full Text Available The study was conducted at the Awash National Park (ANP Ethiopia, todocument Invasive Alien Species (IAS and to assess the spread of Prosopis juliflora (Sw. DC. A total of 64 sample plots were laid systematically along the altitudinal gradient of 750 to 1916 m.Potential IAS were recorded. IAS which may threaten biodiversity of the park includes species such as Prosopis juliflora, Parthenium hysterophorus L., Cryptostegia grandiflora Roxb. ex R. Br., Parkinsonia aculeata L., Senna occidentalis (L. Link, Datura ferox L. and Xanthium strumarium L. Except P. juliflora and P. hysterophorus, all others were not recorded in Ethiopia as IAS. P.juliflora was recorded in three plots with cover of 1% to 10%. P. juliflora was also found spread in different parts of the park particularly following the route of cattle movement. P. hysterophoruswas recorded in and around nine sample plots. Plot 46, 47 and 48 werehighly infested by P. hysterophorus which covered more than 60, 70 and 80% of the ground layer respectively. C. grandiflora was recorded in 11 plots with cover ranging from 1% to 35%. In view of all the natural as well as anthropogenic threats to the biodiversity of the Park, the ANP is at high risk. The rich biodiversity needsimmediate management intervention.

  10. 海洋外来物种入侵对南海生态系统的影响及防控对策%Impacts of alien species invasion on the South China Sea ecosystem and related control strategies

    Institute of Scientific and Technical Information of China (English)

    陆琴燕; 刘永; 李纯厚; 魏小岚; 刘勇

    2013-01-01

    外来海洋物种入侵已成为继海洋栖息地破坏之后世界海洋生态环境面临的第二个重大威胁.为了全面了解我国南海外来物种的状况,本文阐述了南海主要外来物种的生物学和生态学特征及其对生态系统的影响,并提出相应的防控对策.结果表明:(1)在我国南海最主要分布和已经报道的外来物种共有35种,多为无意引进.其中,海洋外来藻类最多,为16种,占总种类数的45.7%;其次是海洋污损动物,为11种,占31.4%;外来微生物,为5种,占14.3%;潮间带滩涂植物主要有3种,占8.6%.(2)外来入侵物种主要通过4个方面危害海洋生态系统:弱化海洋生态系统群落结构,降低其物种多样性;改变海洋生态系统遗传多样性,降低其遗传变异性;影响海洋生态系统稳定性,造成外源病害肆虐;加剧海洋生态灾害.本文对南海不同种类外来物种生物学特征分析可为南海外来物种入侵的进一步研究提供基础资料,防控对策的提出可为管理部门制定海洋外来物种入侵管理策略提供参考,以期更好地保护南海海洋生态系统.%Alien species invasion is generally regarded as the second serious threat following habitat destruction to marine ecosystem.This paper elaborated the biological and ecological characters of marine alien species in the South China Sea and the impacts of these species invasion on the South China Sea ecosystem,and put forward the corresponding control strategies.There were totally 35 alien species in the South China Sea,most of which were accidentally introduced species.Among the alien species,alien algae were dominant (16 species,45.7% of the total),followed by fouling animals (11 species,31.4%),alien microorganisms (5 species,14.3%),and intertidal plants (3 species,8.6%).The alien species invasion weakened the community structure and reduced the biodiversity,altered the genetic diversity and decreased the genetic

  11. Simulation of surface acoustic wave motor with spherical slider.

    Science.gov (United States)

    Morita, T; Kurosawa, M K; Higuchi, T

    1999-01-01

    The operation of a surface acoustic wave (SAW) motor using spherical-shaped sliders was demonstrated by Kurosawa et al. (1994). It was necessary to modify the previous simulation models for usual ultrasonic motors because of this slider shape and the high frequency vibration. A conventional ultrasonic motor has a flat contact surface slider and a hundredth driving frequency; so, the tangential motion caused by the elasticity of the slider and stator with regard to the spherical slider of the SAW motor requires further investigation. In this paper, a dynamic simulation model for the SAW motor is proposed. From the simulation result, the mechanism of the SAW motor was clarified (i.e., levitation and contact conditions were repeated during the operation). The transient response of the motor speed was simulated. The relationships between frictional factor and time constant and vibration velocity of the stator and the slider speed were understood. The detailed research regarding the elastic deformation caused by preload would be helpful to construct an exact simulation model for the next work.

  12. Construction and Application of Basic Data Acquisition and Management System for Fujian Province's Alien Invasive Species%福建外来入侵生物基础数据采集管理系统构建与应用

    Institute of Scientific and Technical Information of China (English)

    陈宏; 赵健; 池美香; 邱荣洲; 翁启勇

    2011-01-01

    针对福建外来入侵生物防控工作中对历史数据管理、部门调查数据协同与交换、数据分析与展示中存在的实际问题,结合“3S”技术(地理信息系统技术、遥感技术和全球定位技术)、移动智能终端、3G移动通信网络等现代信息技术,设计了福建外来入侵生物数据采集与管理的协同工作模式,并开发了福建外来入侵生物基础数据采集管理系统与采集设备.实现了不同的用户对外来入侵生物信息的采集、传输、管理、查询和发布等完整的信息处理流程.在建设过程中完成了156种福建主要外来入侵生物基础数据的收集、整理和数据入库,以期为福建省外来入侵生物风险分析和预警监测提供基础数据来源和技术支撑.%In order to solve the problem about the historical data management, collaboration and exchange department of survey data, data analysis and display of prevention and control of alien invasive species in Fujian province, geographic information systems technology, remote sensing and global positioning systems (the 3S technology), personal digital assistant and third generation mobile communication system were applied to design the data acquisition and management team work model of alien invasive species for Fujian province in this study, and realize the information system and develop data acquisition devices. For different user needs, the system realizes the alien invasive species information processing flow, such as data acquisition, data transmission, data management, data query and publish information. This study has completed to acquire, collate and store 156 alien invasive species records in Fujian province. Implementation and operation of system could provide basic data sources, technology and devices supports for risk assessment and early warning monitor with alien invasive species in Fujian province.

  13. The Problem and Status of the Alien Invasive Plants in China%中国外来入侵植物研究现状及存在的问题

    Institute of Scientific and Technical Information of China (English)

    闫小玲; 寿海洋; 马金双

    2012-01-01

    生物入侵是当今各国发展的一大挑战,特别是像中国这样的发展中国家.然而,我们对外来入侵种的本底资料还很不清楚,更缺乏相关的深入调查;对生物入侵所造成的生态和经济影响还没有引起足够的重视,同时也忽视了盲目引种可能带来的各种危害.本文在文献调研的基础上,从外来植物的入侵历史和文化、中国外来入侵植物的调查现状、外米植物入侵对生态安全及经济的影响等方面进行了全面系统的总结,并提出了中国外来入侵植物研究领域存在的问题及应对措施.%The biological invasion has become a major challenge on global development, especially for whole developing country like China. However, the background data of invasive species in China is still far from completed, and the relevant investigation of the Chinese invasive inforatmion has not been fully available yet today. The huge ecological and economic impacts caused by various invasive species have not been fully noticed or observed by the relative institutions and scientists, plus the ignorance of dangerous invasion with the introduction of alien species. Based on various literatures, the history and culture of invasive plant species, their invasive status and impact on ecological security and economic loss in China have been fully reviewed; and the problems existed and mangement measures of alien invasive plants in China have been fully proposed and summarized in order to provide basic information on the management of invasive plant species in China, and appeal to the government and the community to improve their Risk-Prevention strategies and great sense of urgency with alien invasive plants in China.

  14. Invasive mechanism and manasement stratesy of Bemisia tabaci (Gennadius) biotype B: Progress report of 973 Program on invasive alien species in China

    Institute of Scientific and Technical Information of China (English)

    WAN FangHao; CUI XuHong; ZHANG LiPing; ZHANG Fan; ZHANG QingWen; LIU WanXue; LIANG Pei; LEI ZhongRen; ZHANG YongJun; ZHANG GuiFen; LIU ShuSheng; LUO Chen; CHU Dong; ZHANG YouJun; ZANG LianSheng; JIU Min; Lǖ ZhiChuang

    2009-01-01

    Bemisia tabaci (Gennadius) biotype B, called a "superbug", is one of the most harmful biotypes of this species complex worldwide. In this report, the invasive mechanism and management of B. tabaci bio-type B, based on our 5-year studies, are presented. Six B. tabaci biotypes, B, Q, ZHJ1, ZHJ2, ZHJ3 and FJ1, have been identified in China. Biotype B dominates the other biotypes in many regions of the country. Genetic diversity in biotype B might be induced by host plant, geographical conditions, and/or insecticidal application. The activities of CarE (carboxylesterase) and GSTs (glutathione-S-transferase) in biotype B reared on cucumber and squash were greater than on other host plants, which might have increased its resistance to insecticides. The higher activities of detoxification enzymes in biotype B might be induced by the secondary metabolites in host plants. Higher adaptive ability of biotype B adults to adverse conditions might be linked to the expression of heat shock protein genes. The in-digenous B. tabaci biotypes were displaced by the biotype B within 225 d. The asymmetric mating in-teractions and mutualism between biotype B and begomoviruses via its host plants speed up wide-spread invasion and displacement of other biotypes. B. tabaci biotype B displaced Trialeurodes vapo-rariorum (Westwood) after 4-7 generations under glasshouse conditions. Greater adaptive ability of the biotype B to adverse conditions and its rapid population increase might be the reasons of its suc-cessful displacement of T. vaporariorum. Greater ability of the biotype B to switch to different host plants may enrich its host plants, which might enable it to better compete with T. vaporariorum. Native predatory natural enemies possess greater ability to suppress B. tabaci under field conditions. The kairomones in the 3rd and 4th instars of biotype B may provide an important stimulus in host searching and location by its parasitoids. The present results provide useful information in

  15. Invasive mechanism and management strategy of Bemisia tabaci(Gennadius) biotype B:Progress report of 973 Program on invasive alien species in China

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Bemisia tabaci(Gennadius) biotype B,called a "superbug",is one of the most harmful biotypes of this species complex worldwide.In this report,the invasive mechanism and management of B.tabaci biotype B,based on our 5-year studies,are presented.Six B.tabaci biotypes,B,Q,ZHJ1,ZHJ2,ZHJ3 and FJ1,have been identified in China.Biotype B dominates the other biotypes in many regions of the country.Genetic diversity in biotype B might be induced by host plant,geographical conditions,and/or insecticidal application.The activities of CarE(carboxylesterase) and GSTs(glutathione-S-transferase) in biotype B reared on cucumber and squash were greater than on other host plants,which might have increased its resistance to insecticides.The higher activities of detoxification enzymes in biotype B might be induced by the secondary metabolites in host plants.Higher adaptive ability of biotype B adults to adverse conditions might be linked to the expression of heat shock protein genes.The indigenous B.tabaci biotypes were displaced by the biotype B within 225 d.The asymmetric mating interactions and mutualism between biotype B and begomoviruses via its host plants speed up widespread invasion and displacement of other biotypes.B.tabaci biotype B displaced Trialeurodes vaporariorum(Westwood) after 4-7 generations under glasshouse conditions.Greater adaptive ability of the biotype B to adverse conditions and its rapid population increase might be the reasons of its successful displacement of T.vaporariorum.Greater ability of the biotype B to switch to different host plants may enrich its host plants,which might enable it to better compete with T.vaporariorum.Native predatory natural enemies possess greater ability to suppress B.tabaci under field conditions.The kairomones in the 3rd and 4th instars of biotype B may provide an important stimulus in host searching and location by its parasitoids.The present results provide useful information in explaining the mechanisms of genetic diversity

  16. Invasive mechanism and management strategy of Bemisia tabaci (Gennadius) biotype B: progress report of 973 Program on invasive alien species in China.

    Science.gov (United States)

    Wan, FangHao; Zhang, GuiFen; Liu, ShuSheng; Luo, Chen; Chu, Dong; Zhang, YouJun; Zang, LianSheng; Jiu, Min; Lü, ZhiChuang; Cui, XuHong; Zhang, LiPing; Zhang, Fan; Zhang, QingWen; Liu, WanXue; Liang, Pei; Lei, ZhongRen; Zhang, YongJun

    2009-01-01

    Bemisia tabaci (Gennadius) biotype B, called a "superbug", is one of the most harmful biotypes of this species complex worldwide. In this report, the invasive mechanism and management of B. tabaci biotype B, based on our 5-year studies, are presented. Six B. tabaci biotypes, B, Q, ZHJ1, ZHJ2, ZHJ3 and FJ1, have been identified in China. Biotype B dominates the other biotypes in many regions of the country. Genetic diversity in biotype B might be induced by host plant, geographical conditions, and/or insecticidal application. The activities of CarE (carboxylesterase) and GSTs (glutathione-S-transferase) in biotype B reared on cucumber and squash were greater than on other host plants, which might have increased its resistance to insecticides. The higher activities of detoxification enzymes in biotype B might be induced by the secondary metabolites in host plants. Higher adaptive ability of biotype B adults to adverse conditions might be linked to the expression of heat shock protein genes. The indigenous B. tabaci biotypes were displaced by the biotype B within 225 d. The asymmetric mating interactions and mutualism between biotype B and begomoviruses via its host plants speed up widespread invasion and displacement of other biotypes. B. tabaci biotype B displaced Trialeurodes vaporariorum (Westwood) after 4-7 generations under glasshouse conditions. Greater adaptive ability of the biotype B to adverse conditions and its rapid population increase might be the reasons of its successful displacement of T. vaporariorum. Greater ability of the biotype B to switch to different host plants may enrich its host plants, which might enable it to better compete with T. vaporariorum. Native predatory natural enemies possess greater ability to suppress B. tabaci under field conditions. The kairomones in the 3rd and 4th instars of biotype B may provide an important stimulus in host searching and location by its parasitoids. The present results provide useful information in

  17. Alien Abductions

    Science.gov (United States)

    Nickell, Joe

    2000-03-01

    Since the beginning of the modern UFO craze in 1947, an elaborate mythology has developed concerning alleged extraterrestrial visitations. ``Flying saucer" sightings (typically involving misperceptions of such mundane phenomena as meteors and research balloons) began to be accompanied in the 1950s by reports from ``contactees," persons who claimed to have had close encounters with, even to have been transported to distant planets by, UFO occupants. By the 1960s came reports of sporadic ``abductions" which have proliferated in correlation with media interest. (Indeed, by interaction between claimants and media the portrayal of aliens has evolved from a multiplicity of types into the rather standardized big-eyed humanoid model.) While evidence of alien contact has often been faked--as by spurious photos, ``crop circles," and the notorious ``Alien Autopsy" film--few alien abduction reports appear to be hoaxes. Most seem instead to come from sincere, sane individuals. Nevertheless, not one has been authenticated, and serious investigation shows that such claims can be explained as sleep-related phenomena (notably ``waking dreams"), hypnotic confabulation, and other psychological factors. As is typical of other mythologies, the alien myth involves supernormal beings that may interact with humans, and it purports to explain the workings of the universe and humanity's place within it.

  18. Occurrence and damage of alien invasive weeds in Guangxi agricultural ecosystem%广西农业生态系统外来入侵杂草发生与危害现状分析

    Institute of Scientific and Technical Information of China (English)

    郭成林; 马永林; 马跃峰; 覃建林

    2013-01-01

    [目的]了解广西农业生态系统外来入侵杂草发生与危害状况,为外来入侵杂草的风险评估与防控提供科学依据.[方法]采用文献资料与野外调查相结合的方法,于2011年10月~2012年9月对广西境内14个地级市80个县区稻田、甘蔗地、木薯地、桑园、果园、蔬菜以及其他作物地外来入侵杂草进行系统调查,调查内容包括外来入侵杂草的种类、分布、生境及危害程度.[结果]查明广西农业生态系统有外来入侵杂草101种,隶属27科74属,其中以菊科最多,有25种,其次为禾本科17种、苋科8种、茄科7种、豆科6种、旋花科和大戟科各5种;从植物性状看,以草本植物为主,有88种,占87.13%;从分布特点看,以全区分布为主,有67种,占66.34%;从危害程度看,危害严重的外来杂草有15种,危害程度中等的有22种.[结论]广西农业生态系统外来杂草种类多、数量大、危害重,建立外来物种监测、风险评估及防控体系是防范外来杂草入侵的有效途径.%[Objective]The study was performed to investigate the occurrence and damage of alien invasive weeds in Guangxi agricultural ecosystem in order to provide references for their risk assessment and further prevention and control.[Method] Based on field investigations and related literatures,systematic study was conducted from October 2011 to September 2012 to investigate variety,distribution,habitat and damage degree of invasive weeds in rice,sugarcane,cassava,mulberry,orchard,vegetable and other crop fields in 80 counties and 14 cities of Guangxi.[Result]A total of 101 species of invasive plants belonging to 74 genus and 27 families were identified in Guangxi farmlands.Amongst them,Compositae was the most invasiveweeds,which was consisted of 25 species and it was followed by Gramineae (17 species),Amaranthaceae (8 species),Solanaceae (7 species),Leguminosae (6 species),Convolvulaceae (5 species) and Euphorbiaceae (5 species

  19. 许昌市城郊外来入侵植物调查及危害风险评价%Research and Risk Assessment of Alien Invasive Plants of Xuchang Suburb

    Institute of Scientific and Technical Information of China (English)

    姜罡丞; 王珂; 董东平

    2009-01-01

    The analyses of the invasive plants of Xuchang suburbs show that there are 46 species of invasive plants and they belong to 18 families.They come from North America,South America,Europe and Western Asian in the original.The ways of the invasion include intended introduction of human,non-intended introduction of human activities and nature invasion.The disaster mechanism is mainly affected by the biological characteristics of the plants,appropriate geographical environment and human activities.According to the author's risk assessment system of Xuchang suburbs,21 kinds of alien invasive plants are high risk harm plants and 10 kinds are moderate risk harm plants among 46 alien invasive plants.%对许昌市城郊的外来入侵植物统计分析结果表明:外来入侵植物共有46种,隶属18科;其来源地有南北美洲、欧洲、西亚等地区;入侵途径主要包括人为有意引入、人类活动无意引入和自然侵入;成灾机制则主要受植物本身的生物学特性和适宜的地理环境以及人类活动的影响.据作者建立的许昌市城郊外来入侵植物危害风险评价指标分析:在46种外来入侵植物中,其中有21种属于高风险危害植物,10种属于中风险危害植物.

  20. Species,origins and risk assessment of alien invasive ornamental plants in China%中国外来观赏入侵植物的种类与来源及其风险评价

    Institute of Scientific and Technical Information of China (English)

    王宁; 杜丽; 周兵; 闫小红

    2013-01-01

    Based on literature and previous studies, risks of alien invasive ornamental plants in China were assessed for the first time, taking into consideration of their composition, growth characteristics, detection or in-troduction time and place, and geographical origin. The results show that there are 84 invasive plants belonging to 30 families in China. Most of them were part of Asteraceae, Onagraceae, Leguminosae, Solanaceae and Conv-olvulaceae. Perennial and annual herbs account for the majority. Most of these ornamental plants could repro-duce by seeds and a part of the plants have asexual reproduction ability. They were mainly detected in or intro-duced to China from 1890 to 1969 in coastal provinces and Yunan Province of China. America was the primary geographical origin of these alien invasive plants. The number of the strongest invasive plants, the stronger inva-sive plants and the weaker invasive plants are respectively 8 , 56 and 20 . The majority of the alien invasive orna-mental plants are moderately dangerous.%通过查阅相关文献资料,整理分析中国外来观赏入侵植物的种类组成、生长特性、首次发现或引入时间及地点、地理来源,并对其进行风险评价。结果表明:目前中国外来观赏入侵植物共计84种,隶属30科,其中以菊科、柳叶菜科、豆科、茄科和旋花科植物为主,且多年生和一年生草本植物占据多数;入侵植物繁殖方式多以种子进行繁殖,部分兼具无性繁殖能力;首次发现或引入外来观赏植物时间较集中于1890-1969年,地点主要为中国一些沿海省份以及云南省,其地理上多来源于美洲;属于高、中、低入侵危害等级的外来观赏植物分别有8种、56种和20种,中等风险入侵植物所占比例较高。

  1. Current status of invasive alien pests in Guangxi Province and Vietnam%广西及越南农业外来有害生物入侵现状

    Institute of Scientific and Technical Information of China (English)

    于永浩; 高旭渊; 曾宪儒; 龙秀珍; 韦德卫; 覃建林; 蔡健和; 曾涛

    2016-01-01

    【背景】广西地理环境独特,与越南水陆相连,气候、作物等条件相似,边境贸易往来频繁,致使其成为我国遭受外来有害生物入侵最严重的地区之一。【方法】通过本底调查,分析总结了广西农业外来有害生物入侵的现状。【结果】广西主要入侵动物26种,入侵微生物18种,入侵植物21种,高风险入侵物种包括辣椒实蝇、木薯绵粉蚧、扶桑绵粉蚧、稻水象甲、黄瓜绿斑驳花叶病毒等;来自越南的潜在危险性有害生物共38种。【结论与意义】广西受外来有害生物入侵的风险加剧,并有进一步扩散蔓延的趋势。提出应对入侵生物的综合防控对策,为广西外来入侵有害生物的防控提供参考。%Background] With the unique geographical conditions, and because of the more and more frequent border trade, similar climate and cropping systems in Guangxi and Vietnam, Guangxi Province has become one of the most threatened areas by the inva-sion of alien species in China. [Method] This paper analyzed the current status of the biological invasions in Guangxi via a back-ground survey. [Result] There were 26 species of invasive animals, 18 species of microorganism and 21 species of weeds. Some harmful invasive species of high risk includes the chilifruit fly [ Bactrocera latifrons ( Hendel) ] , the cassava mealybug ( Phenacoccus manihoti Matile-Ferrero) , the solenopsis mealybug ( Phenacoccus solenopsis Tinsley) , the rice water weevil ( Lissorhoptrus oryzophi-lus Kuschel) , and the Cucumber green mottle mosaic virus. 38 potentially hazardous pests from Vietnam are listed. [Conclusion and significance] Risk of harmful invasive species to Guangxi aggravated, with further spread tendency. Comprehensive strategy about the invasive alien pest was proposed, which provided some ideas controlling the invasive alien pests in Guangxi Province.

  2. Alien Invasive Plants in Nanchang Urban Green Land and Its Preventive Measures%南昌城市绿地外来入侵植物及其防治对策

    Institute of Scientific and Technical Information of China (English)

    朱碧华; 杨凤梅

    2012-01-01

    Alien plants invasion,which has caused wide public concern all over the world,threatening the stability and the bearing capability of ecosystem.Moreover,it harming the economic structure of human society and human health,and the loss is beyond estimation.The urban green land is easily influenced of alien plants invasion as a comparatively weaker self-regulate ecosystem.The common species of alien invasive plants in Nanchang urban green land were introduced in this paper,and its attacking ways and the harmful result to the urban green ecosystem were discussed,meanwhile,some relevant prevention measures were put forward.%植物入侵威胁生态系统的稳定性,影响生态系统的承载力,危害人类社会经济结构以及人类健康,造成了无法估量的损失,已经引起全球的普遍关注。城市绿地作为一个自我调节能力相对较弱的生态系统,对外来植物入侵的防范能力比较低,受影响的程度会更大。介绍南昌城市绿地中外来入侵植物的常见种类,探讨外来植物的入侵途径和对城市绿地生态系统的危害,并提出相应的预防措施。

  3. ALIENS IN WESTERN STREAM ECOSYSTEMS

    Science.gov (United States)

    The USEPA's Environmental Monitoring and Assessment Program conducted a five year probability sample of permanent mapped streams in 12 western US states. The study design enables us to determine the extent of selected riparian invasive plants, alien aquatic vertebrates, and some ...

  4. Predicting vibration-induced displacement for a resonant friction slider

    DEFF Research Database (Denmark)

    Fidlin, A.; Thomsen, Jon Juel

    2001-01-01

    A mathematical model is set up to quantify vibration-induced motions of a slider, sandwiched between friction layers with different coefficients of friction, and equipped with an imbedded resonator that oscillates at high frequency and small amplitude. This model is highly nonlinear, involving non...... of the full equations of motion. The expressions are used to estimate and explain the influence of system parameters....

  5. egoSlider: Visual Analysis of Egocentric Network Evolution.

    Science.gov (United States)

    Wu, Yanhong; Pitipornvivat, Naveen; Zhao, Jian; Yang, Sixiao; Huang, Guowei; Qu, Huamin

    2016-01-01

    Ego-network, which represents relationships between a specific individual, i.e., the ego, and people connected to it, i.e., alters, is a critical target to study in social network analysis. Evolutionary patterns of ego-networks along time provide huge insights to many domains such as sociology, anthropology, and psychology. However, the analysis of dynamic ego-networks remains challenging due to its complicated time-varying graph structures, for example: alters come and leave, ties grow stronger and fade away, and alter communities merge and split. Most of the existing dynamic graph visualization techniques mainly focus on topological changes of the entire network, which is not adequate for egocentric analytical tasks. In this paper, we present egoSlider, a visual analysis system for exploring and comparing dynamic ego-networks. egoSlider provides a holistic picture of the data through multiple interactively coordinated views, revealing ego-network evolutionary patterns at three different layers: a macroscopic level for summarizing the entire ego-network data, a mesoscopic level for overviewing specific individuals' ego-network evolutions, and a microscopic level for displaying detailed temporal information of egos and their alters. We demonstrate the effectiveness of egoSlider with a usage scenario with the DBLP publication records. Also, a controlled user study indicates that in general egoSlider outperforms a baseline visualization of dynamic networks for completing egocentric analytical tasks.

  6. Practical extensions of point labeling in the slider model

    NARCIS (Netherlands)

    Strijk, T.; Kreveld, M.J. van

    2001-01-01

    This paper extends on research by the authors together with Alexander Wolff on point label placement using a model where labels can be placed at any position that touches the point (the slider model). Such models have been shown to perform better than methods that allow only a fixed number of positi

  7. Sliders Versus Storyboards - Investigating Interaction Design for Mobile Video Browsing

    NARCIS (Netherlands)

    Hürst, Wolfgang; Hoet, Miklas

    2015-01-01

    We present a comparative study of two different interfaces for mobile video browsing on tablet devices following two basic concepts - storyboard designs representing a video’s content in a grid-like arrangement of static images extracted from the file, and slider interfaces enabling users to interac

  8. A Preliminary Study on the Alien Invasive Plant Species in Huangshanlu Forest Park,Guangzhou%广州南沙黄山鲁森林公园外来入侵植物初步研究

    Institute of Scientific and Technical Information of China (English)

    李海生; 蔡惠娟; 李济明; 邓华源; 钟碧玲

    2015-01-01

    Based on field investigation and literature research,the species,life form,growth situation, the ways of invasion and hazard situation of invasive plants in Huangshanlu Forest Park were preliminarily studied.The results showed that there were thirty species of alien invasive plants belonging to 29 genera of 14 families in Huangshanlu Forest Park.Of them,six alien invasive plant species belong to Poaceae and seven belong to Asteraceae,occupying 43.3% of the total number of invasive plants.Analysis of the life form showed that the most dominant plants were terrestrial herbs (21 species),then shrubs (4 species), vines(3 species),trees and aquatic herbs(1 species respectively),all of them mainly growing in the heavily disturbed areas.In addition,with the analysis of growth characteristics and distribution of ecological traits in the field,seven alien invasive species were evaluated to be at the highest degree of threat to the local biodiversity,nine at the medium,and fourteen at the lowest.Based on the origin,15 species from Tropical America,occupied 50% of the total alien invasive species in Huangshanlu Forest Park.%通过野外调查,结合文献资料,对广州南沙黄山鲁森林公园入侵植物的种类、生活型、生境状况、入侵途径以及危害状况等进行了初步研究.结果表明:黄山鲁森林公园现有外来入侵植物30种,隶属14科29属,其中禾本科(6种)、菊科(7种)植物占总入侵植物种数的43.3%.对入侵植物的生活型分析发现,陆生草本植物最多(21种),其次为灌木(4种)、藤本植物(3种),乔木和水生草本种类最少(各1种),入侵植物主要生长在受人为干扰较大的区域.此外,对入侵植物生长特性及分布等生态学特征分析,可将其对黄山鲁森林公园生物多样性危害程度大致分为3级,其中危害严重的有7种,危害中等的有9种,危害较轻的有14种.从原产地分析来看,15种来自于热带美洲地区,

  9. 北京松山自然保护区外来入侵植物研究%The Research of Alien Invasive Plant in Beijing Songshan Nature Reserve

    Institute of Scientific and Technical Information of China (English)

    刘佳凯; 姚可侃; 张容; 夏阳; 王慧慧; 张振明; 吴计贵; 蒋万杰

    2012-01-01

    为了对松山地区外来植物进行长期有效的监测和管理,防止其对当地的自然生态系统造成破坏,对松山国家级自然保护区的植物进行了详细的样方调查,并对保护区外来入侵植物的分布和相对盖度进行分析.结果表明:松山自然保护区共发现外来植物入侵植物23种,隶属于12科17属,其中大麻(Cannabis sativa)、反枝苋(Amaranthus retroflexus)、萱草(Hemerocallis fulva)、洋槐(Robinia pseudoacacia)、荷包豆(Phaseolus coccineus)等较为常见,影响外来植物入侵的主要因素是道路修建和坡向.该区域的外来物种的各种群规模不大,且多集中在人为活动较为频繁的实验区,对保护区内重点保护的天然次生油松林以及落叶阔叶次生林的生态系统并不存在特别大的威胁.%In order to establish a long-term monitoring mechanism of exotic plants in Songshan Nature Reserve, the author conducted this study, through the survey and the analysis of distribution and relative coverage of alien invasive plants in Songshan Nature Reserve, the results showed that 23 species of alien invasive plants were found, belonging to 12 families and 17 generas. Among them marijuana (Cannabis sativa), redroot amaranth (Amaranthus retroflexus), day lily (Hemerocallis fulva), acacia {Robinia pseudoacacia) and scarlet runner bean (Phaseolus coccineus) were more common. The road construction was the first factor, which influenced and promoted the distribution of alien plants. The next factor was the aspect. Research showed that the alien species population scale was not big and the adverse impact on the local ecological system was not obvious.

  10. Widespread plant species: natives vs. aliens in our changing world

    Science.gov (United States)

    Stohlgren, Thomas J.; Pyšek, Petr; Kartesz, John; Nishino, Misako; Pauchard, Aníbal; Winter, Marten; Pino, Joan; Richardson, David M.; Wilson, John R.U.; Murray, Brad R.; Phillips, Megan L.; Ming-yang, Li; Celesti-Grapow, Laura; Font, Xavier

    2011-01-01

    Estimates of the level of invasion for a region are traditionally based on relative numbers of native and alien species. However, alien species differ dramatically in the size of their invasive ranges. Here we present the first study to quantify the level of invasion for several regions of the world in terms of the most widely distributed plant species (natives vs. aliens). Aliens accounted for 51.3% of the 120 most widely distributed plant species in North America, 43.3% in New South Wales (Australia), 34.2% in Chile, 29.7% in Argentina, and 22.5% in the Republic of South Africa. However, Europe had only 1% of alien species among the most widespread species of the flora. Across regions, alien species relative to native species were either as well-distributed (10 comparisons) or more widely distributed (5 comparisons). These striking patterns highlight the profound contribution that widespread invasive alien plants make to floristic dominance patterns across different regions. Many of the most widespread species are alien plants, and, in particular, Europe and Asia appear as major contributors to the homogenization of the floras in the Americas. We recommend that spatial extent of invasion should be explicitly incorporated in assessments of invasibility, globalization, and risk assessments.

  11. Widespread plant species: Natives versus aliens in our changing world

    Science.gov (United States)

    Stohlgren, T.J.; Pysek, P.; Kartesz, J.; Nishino, M.; Pauchard, A.; Winter, M.; Pino, J.; Richardson, D.M.; Wilson, J.R.U.; Murray, B.R.; Phillips, M.L.; Ming-yang, L.; Celesti-Grapow, L.; Font, X.

    2011-01-01

    Estimates of the level of invasion for a region are traditionally based on relative numbers of native and alien species. However, alien species differ dramatically in the size of their invasive ranges. Here we present the first study to quantify the level of invasion for several regions of the world in terms of the most widely distributed plant species (natives vs. aliens). Aliens accounted for 51.3% of the 120 most widely distributed plant species in North America, 43.3% in New South Wales (Australia), 34.2% in Chile, 29.7% in Argentina, and 22.5% in the Republic of South Africa. However, Europe had only 1% of alien species among the most widespread species of the flora. Across regions, alien species relative to native species were either as well-distributed (10 comparisons) or more widely distributed (5 comparisons). These striking patterns highlight the profound contribution that widespread invasive alien plants make to floristic dominance patterns across different regions. Many of the most widespread species are alien plants, and, in particular, Europe and Asia appear as major contributors to the homogenization of the floras in the Americas. We recommend that spatial extent of invasion should be explicitly incorporated in assessments of invasibility, globalization, and risk assessments. ?? 2011 Springer Science+Business Media B.V.

  12. Feeding kinematics of freshwater turtles: what advantage do invasive species possess?

    Science.gov (United States)

    Nishizawa, Hideaki; Tabata, Runa; Hori, Tomoya; Mitamura, Hiromich; Arai, Nobuaki

    2014-10-01

    The red-eared slider (Trachemys scripta) is an invasive turtle species that is displacing the populations of native freshwater turtles in many countries. However, the mechanism that makes red-eared sliders superior competitors has been less well studied. In this study, we compare the feeding kinematics of the red-eared slider with those of Reeves' pond turtle (Mauremys reevesii), a turtle native to East Asia, and offer an explanation as to why red-eared sliders are superior in food competition. Reeves' pond turtles sympatric to red-eared sliders have been reported to have a mainly durophagous diet in contrast to the preference for a soft diet in areas of allopatry to red-eared sliders, indicating the dietary shift resulted from food competition. Maximum neck extension and retraction speed are considered to be indicators of striking ability, but were not found to be superior in red-eared sliders. In fact, maximum neck extension speed was significantly higher in Reeves' pond turtles, though this advantage may be counteracted by the longer neck of Reeves' pond turtles, resulting in similar neck extension times. On the other hand, red-eared sliders had a significantly shorter gape cycle time and neck retraction time, indicating that they can complete feeding in a short time. Therefore, red-eared sliders are suggested to be superior in food competition not due to their striking ability, but due to exploiting preferable food in a shorter time.

  13. 外来入侵植物小飞蓬化感作用机理研究的进展%The Progress of Studies on the Allelopathy Mechanism of Alien Invasive Plant Conyza Canadensis ( L. ) Cronq.

    Institute of Scientific and Technical Information of China (English)

    张海燕; 罗鑫; 张敏

    2015-01-01

    入侵植物会损害环境生态系统,影响生物的多样性,给农业生产带来严重的经济损失.目前,虽然入侵植物的化感作用研究较多,但是很多缺乏对化感作用的深入研究.结合国内外入侵植物的研究进展,该研究阐述了小飞蓬的研究现状、化感物质的分离鉴定方法以及入侵机理研究的进展.参24.%Alien invasive plants can damage the ecological environment system,have influence on the biological diversity and bring serious economic losses to the agricultural production. At present,there are many studies on the allelopathic effect of the invasive plants,but lack of deep research on the mechanism of allelopathy. Combined with the research progress of invasive plants at home and abroad,this paper in-troduce research actuality, methods of isolation, identification allelochemicals and the progress in the mechanism research of Conyza Canadensis. 24refs.

  14. A DYNAMIC MODEL FOR A DISC EXCITED BY VERTICALLY MISALIGNED, ROTATING, FRICTIONAL SLIDERS

    Institute of Scientific and Technical Information of China (English)

    OUYANG Huajiang; GU Yuanxian; YANG Haitian

    2004-01-01

    This paper presents a dynamic model for a disc subjected to two sliders rotating in the circumferential direction over the top and bottom surfaces of the disc. The two sliders are vertically misaligned and each is a mass-spring-damper system with friction between the slider and the disc.The moving loads produced by misaligned sliders can destabilise the whole system. Stability analysis is carried out in a simulated example. This model is meant to explain the friction mechanism for generating unstable vibration in many applications involving rotating discs.

  15. The role of the World Trade Organization and the 'three sisters' (the World Organisation for Animal Health, the International Plant Protection Convention and the Codex Alimentarius Commission) in the control of invasive alien species and the preservation of biodiversity.

    Science.gov (United States)

    Kahn, S; Pelgrim, W

    2010-08-01

    The missions of the World Organisation for Animal Health (OIE) include the design of surveillance and control methods for infectious transboundary animal diseases (including zoonoses), the provision of guarantees concerning animal health and animal production food safety, and the setting of standards for, and promotion of, animal welfare. The OIE role in setting standards for the sanitary safety of international trade in animals and animal products is formally recognised in the World Trade Organization (WTO) Agreement on the Application of Sanitary and Phytosanitary Measures (the SPS Agreement). While the primary focus of the OIE is on animal diseases and zoonoses, the OIE has also been working within the WTO framework to examine possible contributions the organisation can make to achieving the goals of the Convention on Biological Diversity, particularly to preventing the global spread of invasive alien species (IAS). However, at the present time, setting standards for invasive species (other than those connected to the cause and distribution of diseases listed by the OIE) is outside the OIE mandate. Any future expansion of the OIE mandate would need to be decided by its Members and resources (expertise and financial contributions) for an extended standard-setting work programme secured. The other international standard-setting organisations referenced by the SPS Agreement are the International Plant Protection Convention (IPPC) and the Codex Alimentarius Commission (CAC). The IPPC mandate and work programme address IAS and the protection of biodiversity. The CAC is not involved in this field.

  16. Slider Posture Effects on Air Bearing in a Heat-Assisted Magnetic Recording System

    Directory of Open Access Journals (Sweden)

    Kyaw Sett Myo

    2012-01-01

    Full Text Available This paper reports the effects of slider posture on the slider bearing in a heat-assisted magnetic recording (HAMR system with the direct simulation Monte Carlo (DSMC method. In this HAMR system, the heat issues on the slider bearings are assumed to be caused by a heated spot on the disk and/or slider body itself at various pitch angles. The simulation results show that with a heated spot on the disk, the air bearing pressure and air bearing force that acted on the slider surface will increase when the pitch angle becomes larger. It is also found that the bearing force increases with the heated spot size and the effects of a heated spot become more obvious at a larger pitch angle. On the other hand, the slider body temperature is observed to have a noticeable effect on air bearing pressure and force. The smaller pitch angle enlarges the tendency of bearing force variations with the slider temperature and makes the slider more sensitive to its temperature changes.

  17. 基于物种生态位与物质能量流互动机制对外来入侵植物的探讨%A Study on Alien Invasive Plants from the Interactive Mechanism between Species Niche and Material/Energy Flow

    Institute of Scientific and Technical Information of China (English)

    陈剑; 喻庆国; 杨宇明

    2011-01-01

    [目的]为揭示外来植物入侵机制的本质.[方法]本文以物种生态位与环境物质能量流为基本研究参量,分析外来植物入侵的内在机制.[结果]认为通常情况下外来入侵植物缺乏明确的定义标准和有效防治方法.[结论]外来入侵植物的泛滥取决于该物种生态位在空间上是否获得连续的满足,以此为基础提出了相应的防治措施,对构建"柱网模型"提出设想,并对外来入侵植物概念本身提出讨论.%[Objective]This study was to reveal the essence of mechanism about how the alien invasive plants spread.[Method]Species niche and material/energy flow were used as basic research indicators to analyze the intrinsic mechanism of alien plants invasion.[Result]Most of the invasive plants have not been explicitly defined and their effective control methods not brought forward.[Conclusion]Overrun of alien invasive plants depends on whether the niche of a species could be continuously met at spatial level.Based on this we put forward corresponding control measures, proposed an assumption to establish a cylinder-network model and discussed the definition of alien invasive plants.

  18. Biological and Ecological Characteristics of an Invasive Alien Species Spartina in Yellow River Delta%黄河三角洲外来入侵物种米草的生物学与生态学特性

    Institute of Scientific and Technical Information of China (English)

    石东里; 田家怡; 陈印平

    2009-01-01

    In Yellow River Delta,the biological and ecological characteristics of an invasive alien spe-cies spartina were investigated. The results showed that the stem of spartina is tenacious and many gas chambers are in epidermal parencbyma of its rhizome. These characteristics ensure that it can live in flooding conditions. Salt gland that is under surface of its leaf and can secret and discharge salt. Water loss can make seed fail to germination. Its capability of asexual reproduction is strong and that is the bio-logical base of its spreading. Its euryhalinity, submergence tolerance, high adaptability and reproductive capacity,strong high invasion capacity and great ecological amplitude are the ecological base of its inva-sion and development.%对黄河三角洲外来入侵物种米草的生物学、生态学特性进行了观测和研究.结果表明:米草茎秆坚韧,不易倒伏;根状茎表皮薄壁组织内有许多气腔,与淹水条件下生活的习性相适应;米草叶背面有盐腺,便于泌盐和排盐;米草种子失水即失去萌发力,无性繁殖力强,是其扩散的生物学基础;米草的广盐性、耐淹性、高适应性、强繁殖扩散能力、强竞争入侵能力、生态幅宽,是其入侵和爆发的生态学基础.

  19. A Research Review of Invasive Mechanism of Alien Plant Ambrosia Artemisiifolia and Its Present Situation%外来植物豚草的入侵机理研究进展及其现状

    Institute of Scientific and Technical Information of China (English)

    柏祥; 刘传才; 塔莉; 王连龙

    2015-01-01

    从外来植物的入侵性和生境的可入侵性两方面综述了外来植物豚草的入侵机理研究进展,分析了豚草在秦皇岛地区的现状,以中国环境管理干部学院新校区为例调查了人类活动干扰对豚草的影响。豚草的入侵性与其自身所具有的生理生态学特性密切相关,生境的可入侵性则与其群落特征和受干扰程度等因素有关。目前豚草是秦皇岛地区自然群落的建群种,没有表现出入侵性。新校区调查结果表明:豚草在自然群落中零星分布,但受到人类活动干扰的生境中豚草表现出一定的优势度。因此,在豚草防治中应防止人类活动的过度干扰影响,以保护当地的生态环境。%A research review was presented on invasive mechanism of alien plant Ambrosia art-emisiifolia in terms of its invasiveness and the habitat invisibility. The present situation of the plant was analyzed in Qinhuangdao region, and the new campus was taken as an example to inves-tigate the effects of human activity disturbance on A. artemisiifolia. The invasiveness of A. artemisiifolia was closely related to its ecophysiological characteristics, while the habitat invisibility was impacted by community characteristics and disturbance degree. In present, the plant was a community construction species in this region, and showed no invasion. The investigated results showed that A. artemisiifolia distributed sporadically in the natural community. However, in the habitat disturbed by human activities, the plant had relatively high advantage. Therefore, excessive human activity disturbance should be prevented to control the invasive plant, by which to protect the local ecological environment.

  20. Legislation for Prevention of Alien Species Invasion%预防外来物种入侵的立法对策

    Institute of Scientific and Technical Information of China (English)

    渠烨

    2011-01-01

    This paper analyzed the present situation of prevention of alien species in China, pointed out the legislative maladies of non special laws, existent deviation and limited scope. It put forward the countermeasures on definiting legislative aims,making special laws and middle and long term planning, expanding coverage,improving laws and regulations and acclimating international situation.%对我国目前预防外来物种入侵问题的现状进行了分析,指出了我国在预防外来物种入侵立法上没有专门的针对性法律,立法目的有偏差、法律涉及范围有限的弊病,提出了明确立法目的、制订专项立法与中长期规划、适当扩大相关法律覆盖范围、完善法律法规和顺应国际形势的立法对策.

  1. How many marine aliens in Europe?

    Directory of Open Access Journals (Sweden)

    Stelios Katsanevakis

    2013-01-01

    Full Text Available In the framework of the European Alien Species Information Network (EASIN; http://easin.jrc.ec.europa.eu/, an inventory of marine alienspecies in Europe was created by critically reviewing existing information in 34 global, European, regional and national databases. In total, 1369 marine alien species have been reported in the European seas (including 110 cryptogenic and 139 questionable species; this is a substantial increase from the 737 species previously reported in 2009 based on the DAISIE (Delivering Alien Invasive Species Inventories for Europe; http://www.europe-aliens.org dataset. Most of the reported species were invertebrates (63.3%, followed by chromists (13.7%, vertebrates (11.6%, and plants (10.1%. Mollusca is the most numerous phylum, followed by Arthropoda, Chordata, and Annelida. Thecountries with the highest reported numbers of marine alien species were Israel, Turkey, Italy, France, Egypt and Greece. A reporting bias is evident as efforts for monitoring and reporting alien species vary among countries.

  2. Variable viscosity condition in the modeling of a slider bearing

    CERN Document Server

    Uprety, Kedar Nath

    2014-01-01

    To reduce tear and wear of machinery lubrication is essential. Lubricants form a layer between two surfaces preventing direct contact and reduce friction between moving parts and hence reduce wear. In this short letter the lubrication of two slider bearings with parallel and nonparallel is studied. First, we show that bearings with parallel plates cannot support any load. For bearings with nonparallel plates we are interested on how constant and temperature dependent viscosity affects the properties of the bearings. Also, a critical temperature for which the bearings would fail due to excess in temperature is found for both latter cases. If the viscosity is constant, the critical temperature is given by an explicit formula, while for the non-constant viscosity the critical temperature can be always found from a closed form formula involving Weber functions

  3. Studies on Flora Alien Invasive Plants and Disastrous Mechanisms in Wanzhou, Chongqing%重庆市万州区入侵植物区系特征与成灾机制研究

    Institute of Scientific and Technical Information of China (English)

    余顺慧; 邓洪平

    2011-01-01

    According to the outside invading Plant' s final research of Wanzhou it indicates: (1) There are 45 species of flora alien invasive plants which have been already known at present, they belong to 35 genera and 20 families in Wanzhou; (2) The flora shows an obvious tropic characteristics; (3) Most of them are produced in America. Accordingly, The outside causing disaster invading plant's mechanism in Wanzhou has shown the close connection being a geographical feature component with area, has drawn attention in responding to in area vegetation process besides introducing a fine variety.%采取野外样方调查和资料分析方法,对重庆市万州区入侵植物区系特征及其成灾机制进行研究.结果表明:①万州区有入侵植物共20科、35属、45种;②该区入侵植物在科属分布区类型上除世界分布外,主要为热带分布;③入侵植物大部分来源于美洲.该文还探讨了万州区入侵植物的成灾机制与其区系地理成分之间的密切联系.

  4. First Report of Outbreaks of the Fall Armyworm Spodoptera frugiperda (J E Smith) (Lepidoptera, Noctuidae), a New Alien Invasive Pest in West and Central Africa

    Science.gov (United States)

    Sankung, Sagnia B.; Togola, Abou; Tamò, Manuele

    2016-01-01

    The fall armyworm Spodoptera frugiperda is a prime noctuid pest of maize on the American continents where it has remained confined despite occasional interceptions by European quarantine services in recent years. The pest has currently become a new invasive species in West and Central Africa where outbreaks were recorded for the first time in early 2016. The presence of at least two distinct haplotypes within samples collected on maize in Nigeria and São Tomé suggests multiple introductions into the African continent. Implications of this new threat to the maize crop in tropical Africa are briefly discussed. PMID:27788251

  5. Controling measures on invasive alien plant "Spartina alterniflora"%外来入侵植物——互花米草的控制措施

    Institute of Scientific and Technical Information of China (English)

    林嵩

    2012-01-01

    This article summarized some controling measures on Spartina alterniflora in the domestic and foreign, including physical, chemical, biological, bio-substitution methods. In connection with the existing problems, it is proposed that the comprehensive prevention and control measures could reach the ideal results to control spartina, alterniflorain invasion.%综述了国内外控制互花米草入侵采取的措施,其中包括物理、化学、生物和生物替代等措施,并针对存在的问题,提出控制互花米草的综合措施。

  6. Attacking invasive grasses

    Science.gov (United States)

    Keeley, Jon E.

    2015-01-01

    In grasslands fire may play a role in the plant invasion process, both by creating disturbances that potentially favour non-native invasions and as a possible tool for controlling alien invasions. Havill et al. (Applied Vegetation Science, 18, 2015, this issue) determine how native and non-native species respond to different fire regimes as a first step in understanding the potential control of invasive grasses.

  7. Characteristics of HgCdTe epilayer grown by LPE using horizontal slider

    Indian Academy of Sciences (India)

    J K Radhakrishnan; S Sitharaman; S C Gupta

    2002-11-01

    The characteristics of HgCdTe epilayers grown in a modified horizontal slider system, are reported here. The surface morphology of the grown layers, their IR transmission characteristics, depth and lateral compositional uniformity, structural and electrical characteristics are discussed.

  8. Thermal Analysis of Heat-Assisted Magnetic Recording Optical Head with Laser Diode on Slider

    Science.gov (United States)

    Xu, Baoxi; Chia, Cheow Wee; Zhang, Qide; Teck Toh, Yeow; An, Chengwu; Vienne, Guillaume

    2011-09-01

    For the optical head used in heat-assisted magnetic recording (HAMR), mounting a laser diode chip on the slider offers a more integrated, compact, and stable design. However, the heat generated by the laser diode will cause the head temperature to increase, which may decrease the laser output power and change the slider flying status. In this paper, the thermal analysis of the HAMR head including the laser diode and a transducer is conducted. The effects of the laser diode power, the power absorbed by the transducer, boundary thermal resistance between the laser diode chip and the slider substrate, and slider fly speed and fly height on the laser temperature increase, the transducer temperature increase, and the air-bearing surface temperature distribution are studied. The deformation of the air-bearing surface caused by its temperature change is also analyzed.

  9. Use of non-timber forest products from invasive alien Prosopis species(mesquite) and native trees in South Africa: implications for management

    Institute of Scientific and Technical Information of China (English)

    Ross; T; Shackleton; David; C; Le; Maitre; Brian; W; van; Wilgen; David; M; Richardson

    2015-01-01

    Background: Prosopis species have been introduced to many areas outside their native range to provide benefits to local communities. Several Prosopis species and their hybrids(hereafter "mesquite") have, however, become naturalised and invasive and now generate substantial costs. Management options are limited because of the complex conflicts of interest regarding benefits and costs. Management policies and strategies must take account of such conflicts, but further insights are needed on the dimensions of uses and impacts before such information can be usefully applied. Current policy in South Africa allows for the growth and use of mesquite in one province,but not in others where its control is mandatory. We report on a study to quantify the direct use and perceptions of non-timber forest products(NTFPs) from mesquite and native trees in South Africa.Methods: Semi-structures household interviews were conducted with various stakeholder groups to identify what tree products are used, to ascertain amounts used as well as to gauge perceptions of natural resource use between different tree species and use over time.Results: The direct household use value of native trees was higher than that of mesquite, and local stakeholders attached greater value to products from native trees than from mesquite. Therefore, native trees are and will still be preferentially harvested, and mesquite is unlikely to offer protection to native species by providing an alternative source of products. Mesquite pods do, however, provide valuable additional resources(fodder and medicinal products). The use of both native trees and mesquite is decreasing as the incomes of poorer households rise and as alternative energy sources become available. The benefits and reliance on mesquite are not as high as previously assumed and the impacts from mesquite invasions create large problems for local communities.Conclusion: This study provides further evidence that the impacts of mesquite exceed the

  10. Alienation and Education.

    Science.gov (United States)

    Reimanis, Gunars

    This paper reviews the author's research on the role of certain aspects of alienation in education. The first part of the paper discusses similarities between anomie and locus of reinforcement control, as they assess the normlessness and powerlessness aspects of alienation. The second part reports results from studies attempting to modify one's…

  11. The Roots Of Alienation

    Science.gov (United States)

    Bronfenbrenner, Urie

    1973-01-01

    Alienation in our society takes several forms--withdrawal, hostility, or efforts to reform. The author traces the roots of alienation to our neglect of many of the needs of children, particularly their need for interaction with adults. Among his many recommendations are: modified work schedules to permit more time with children and systems for…

  12. The aliens are hiding

    Science.gov (United States)

    2015-06-01

    In reply to the physicsworld.com news story “Trail goes cold on alien hotspots, for now” (28 April, http://ow.ly/MeOpZ; see also p5), which described the results of a survey that looked for unexplained pockets of infrared radiation that could have been produced by advanced alien civilizations.

  13. 中国西南纵向岭谷区外来入侵植物对生物多样性的影响%The Impacts of the Alien Invasive Plants on Biodiversity in Longitudinal Range-Gorge Region of Southwest China

    Institute of Scientific and Technical Information of China (English)

    陆树刚; 徐成东; 董晓东; 段玉清; 王奕

    2006-01-01

    This paper deals with the impacts of the alien invasive plants on biodiversity in longitudinal range-gorge region of Southwest China. The longitudinal range-gorge region of Southwest China is a critical region for reserving biodiversity and now this region has become a highly endangered region with more than 70 species of alien invasive plants. Among these invasive plants, Ageratina adenophora ( Eupatorium adeophorum ), Chromolaena odorata ( Eupatorium odoratum ), and Tithonia diversifolia are severely imperiling this region. The structure and functions of ecosystems in this region are badly destroyed with the consequences that, the native species are in the face of extinction, and thai agricultural producers, animal husbandry, and forestry activities or even the ecological security are in danger. The damage of alien invasive plants in this region led to a great attention in our country. It is of great practical significance and scientific value to make a comprehensive study of the alien invasive plants of this region, to discover their principles of activity, to slow down their imperiling speed, to wipe out them from this region, and eventually to restore the ecological equilibrium. This paper gives a detailed description of the impacts of the alien invasive plants on the plants species diversity, plants community diversity, ecosystem diversity, agricultural producers, animal husbandry, and forestry. In the end, the authors suggested several solutions to control and wipe out the alien invasive plants.%论述中国西南纵向岭谷区外来入侵植物对生物多样性的影响.中国西南纵向岭谷区是我国生物多样性保护的关键地区.目前,该区域已成为外来植物入侵的重灾区,外来入侵植物种类多达70余种,其中,紫茎泽兰Ageratina adenophora(Eupatorium adenophorum)、飞机草Chromolaena odorata(Eupatorium odoratum)和肿柄菊Tithonia diversifolia等在该区域危害严重,该区域的生态系统的结构与功能遭

  14. [Application of molecular marker techniques in invasion ecology].

    Science.gov (United States)

    Chu, Dong; Zhang, You-jun; Wan, Fang-hao

    2007-06-01

    Alien invasive species can cause huge economic loss in agricultural and forestry production, and threaten biodiversity and human health. The research of invasion ecology is of significance in understanding the invasion mechanisms of alien invasive species and in developing corresponding sustainable control methods. Molecular marker is regarded as a useful tool in approaching some essential issues in the research of invasion ecology. In this paper, the applications of molecular marker techniques in the studies of identification, geographic distribution, invasive source, spread pattern, genetic variation, hybridization, and gene introgression of alien invasive species were reviewed, and the application prospects were discussed.

  15. Ecological state of invasive alien plant Solanum rostratum in Beijing%北京外来入侵植物刺萼龙葵的生态状况

    Institute of Scientific and Technical Information of China (English)

    向俊; 李翠妮; 刘全儒; 周云龙; 孙乐; 毛春明; 梁前进

    2011-01-01

    Field investigation was made on ninety 2 m × 2 m sampling quadrats in Ligezhuang and Xiaocaocun villages of Miyun County, Beijing to analyze the population abundance, frequency, and importance value of invasive alien Solanum rostratum , as well as the species composition and flora characteristics of plant communities, aimed to assess the ecological state and ecological endangering risk of the invasive species based on its growth pattern, ecological advantage, and competitive aspects. In abundance, the S. rostratum was at the third position in Ligezhuang village (a total of 29 plant species) , and at the fifth position in Xiaocaocun village (a total of 51 plant species) ; in frequency, the S. ro.stratum was at the first position both in Ligezhuang and in Xiaocaocun. The importance value indicated that the S. rostratum both in Ligezhuang and in Xiaocaocun had the greatest comprehensive adaptability. Accordingly, the invasion of S. rostratum in Beijing was still at a stage at which the damage was limited and locally, though the plant had overcome its growth bottleneck. Several species belonged to Poaceae, Compositae, and Moraceae had the potential acting as a counterweight to the progressive expansion of S. rostratum. For ecological intervention strategy, it could be established in the native species with some advantages and somehow predominated in adaptation to ecologically substitute or eradicate the invasion of S. rostratum before it became a single dominant species.%调查了北京密云县李各庄和小漕村荒草地90个2 m×2 m草本优势型样方的刺萼龙葵入侵地,分析了样方中各种植物的种类组成和区系特点以及种群的多度、频度和重要值,并结合其生长型、生态优势和竞争关系,评估了北京外来入侵植物刺萼龙葵的生态状况和生态危害风险.结果表明:在多度方面,刺萼龙葵在李各庄群落(共29种植物)中位列第3,在小漕村群落(共51种植物)中位列第5;在频度方面,

  16. Slider-Disk Contacts During the Loading Process in a Ramp-Load Magnetic Disk Drive

    Science.gov (United States)

    Fu, Ta-Chung; Bogy, David B.

    Experimental investigations of the dynamic loading process of a 2.5″ hard disk drive with a ramp loading system are presented. The dual beam Polytec LDV is successfully applied to the measurement of slider-disk relative motion during single load events. An AE system is used to confirm the slider-disk contacts. The effects of different head-load speeds and of different initial pitch and roll angles are examined. It is observed that the following three parameters: (1) Initial loading velocity, which is determined by the actuator swing velocity as well as the disk runout, (2) Initial pitch, and (3) Initial roll, strongly affect the occurrence of the slider-disk contact. An apparent inconsistency between the LDV and AE measurements disappeared after all sliders except the LDV measured one were removed from the drive. Critical ramp speeds below which slider-disk contacts do not occur were established for two different sets of initial pitch and roll for the tested drive.

  17. Generation of noncircular gears for variable motion of the crank-slider mechanism

    Science.gov (United States)

    Niculescu, M.; Andrei, L.; Cristescu, A.

    2016-08-01

    The paper proposes a modified kinematics for the crank-slider mechanism of a nails machine. The variable rotational motion of the driven gear allows to slow down the velocity of the slider in the head forming phase and increases the period for the forming forces to be applied, improving the quality of the final product. The noncircular gears are designed based on a hybrid function for the gear transmission ratio whose parameters enable multiple variations of the noncircular driven gears and crack-slider mechanism kinematics, respectively. The AutoCAD graphical and programming facilities are used (i) to analyse and optimize the slider-crank mechanism output functions, in correlation with the predefined noncircular gears transmission ratio, (ii) to generate the noncircular centrodes using the kinematics hypothesis, (iii) to generate the variable geometry of the gear teeth profiles, based on the rolling method, and (iv) to produce the gears solid virtual models. The study highlights the benefits/limits that the noncircular gears transmission ratio defining hybrid functions have on both crank-slider mechanism kinematics and gears geometry.

  18. Recreational trails as corridors for alien plants in the Rocky Mountains, USA

    Science.gov (United States)

    Wells, Floye H.; Lauenroth, William K.; Bradford, John B.

    2012-01-01

    Alien plant species often use areas of heavy human activity for habitat and dispersal. Roads and utility corridors have been shown to harbor more alien species than the surrounding vegetation and are therefore believed to contribute to alien plant persistence and spread. Recreational trails represent another corridor that could harbor alien species and aid their spread. Effective management of invasive species requires understanding how alien plants are distributed at trailheads and trails and how their dispersal may be influenced by native vegetation. Our overall goal was to investigate the distribution of alien plants at trailheads and trails in the Rocky Mountains of Colorado. At trailheads, we found that although the number of alien species was less than the number of native species, alien plant cover ( x̄=50%) did not differ from native plant cover, and we observed a large number of alien seedlings in the soil seed bank, suggesting that alien plants are a large component of trailhead communities and will continue to be so in the future. Along trails, we found higher alien species richness and cover on trail (as opposed to 4 m from the trail) in 3 out of 4 vegetation types, and we observed higher alien richness and cover in meadows than in other vegetation types. Plant communities at both trailheads and trails, as well as seed banks at trailheads, contain substantial diversity and abundance of alien plants. These results suggest that recreational trails in the Rocky Mountains of Colorado may function as corridors that facilitate the spread of alien species into wildlands. Our results suggest that control of alien plants should begin at trailheads where there are large numbers of aliens and that control efforts on trails should be prioritized by vegetation type.

  19. Life under alien skies

    Science.gov (United States)

    Dartnell, Lewis

    2012-04-01

    As the number of confirmed extrasolar planets increases, so does the likelihood that some of them will harbour life. Lewis Dartnell describes some preliminary - but increasingly well founded - efforts to predict what alien plants and animals might look like.

  20. Parental Alienation Syndrome

    Directory of Open Access Journals (Sweden)

    Fuat Torun

    2011-09-01

    Full Text Available Children who have been programmed by one parent to be alienated from the other parent are commonly seen in the context of child-custody disputes. Its primary manifestation is the child’s campaign of denigration against a parent, a campaign that has no justification. It is said to result from a combination of a programming (brainwashing parent’s indoctrinations and the child’s own contributions to the vilification of the targeted parent. Many evaluators use the term parental alienation syndrome to refer to the disorder engendered in such children. However, there is significant controversy going on about the validity of parental alienation syndrome. The purpose of this article has been to describe and help to differentiate parental alienation syndrome and abuse for mental health professionals working in the field, and discuss the arguments about the validity of this syndrome.

  1. The alien paradox.

    OpenAIRE

    Tugby, Matthew

    2015-01-01

    Platonism delivers a theory of possibility that is distinct from both Lewisian modal realism and ersatz modal theories. By putting the topic of alien properties at centre stage in our modal theorizing, a strong preliminary case for platonism can be made. A puzzle about alien properties is created by modern truthmaker theory and some plausible assumptions about properties and existence. But this puzzle is one that platonism is able to solve in a simple and conservative way.

  2. Interface solution for writing-induced nano-deformation of slider body

    Science.gov (United States)

    Li, Hui; Liu, Bo; Chong, Tow-Chong

    2006-08-01

    Writing-induced nano-deformation of slider body becomes a big concern when the mechanical spacing between the head and disk is continuously reduced to achieve higher magnetic recording areal density. Reduced head-disk spacing increases the risk of head/disk contact and causes the thermal instability in head-disk interface (HDI). This paper reports authors' efforts towards exploration of interface solutions for writing-induced instability in ultra-low head-disk spacing magnetic system. Multi-shallow step structure with optimized rail position is analyzed and a new femto slider with such structure is explored. The results of numerical simulation indicate that the multi-shallow step structure is an effective approach in reducing the flying height change caused by the writing-induced nano-deformation of the slider body.

  3. Alien plant species list and distribution for Camdeboo National Park, Eastern Cape Province, South Africa

    Directory of Open Access Journals (Sweden)

    Mmoto L. Masubelele

    2009-01-01

    Full Text Available Protected areas globally are threatened by the potential negative impacts that invasive alien plants pose, and Camdeboo National Park (CNP, South Africa, is no exception. Alien plants have been recorded in the CNP since 1981, before it was proclaimed a national park by South African National Parks in 2005. This is the first publication of a list of alien plants in and around the CNP. Distribution maps of some of the first recorded alien plant species are also presented and discussed. To date, 39 species of alien plants have been recorded, of which 13 are invasive and one is a transformer weed. The majority of alien plant species in the park are herbaceous (39% and succulent (24% species. The most widespread alien plant species in the CNP are Atriplex inflata (= A. lindleyi subsp. inflata, Salsola tragus (= S. australis and cacti species, especially Opuntia ficus-indica. Eradication and control measures that have been used for specific problematic alien plant species are described. Conservation implications: This article represents the first step in managing invasive alien plants and includes the collation of a species list and basic information on their distribution in and around the protected area. This is important for enabling effective monitoring of both new introductions and the distribution of species already present. We present the first species list and distribution information for Camdeboo National Park.

  4. Entropy generation in non-Newtonian fluid flow in a slider bearing

    Indian Academy of Sciences (India)

    M Pakdemirli; B S Yilbas; M Yurusoy

    2004-12-01

    In the present study, entropy production in flow fields due to slider bearings is formulated. The rate of entropy generation is computed for different fluid properties and geometric configurations of the slider bearing. In order to account for the non-Newtonian effect, a special type of third-grade fluid is considered. It is found that the rate of entropy generation is influenced significantly by the height of the bearing clearance and the non-Newtonian parameter of the fluid.

  5. An Analytical Approach for Analysis of Slider Bearings with Non-Newtonian Lubricants

    Directory of Open Access Journals (Sweden)

    Li-Ming Chu

    2014-01-01

    Full Text Available In this study, a regular perturbation technique is utilized to derive the modified Reynolds equation which is applicable to power-law lubricant. The performance of slider bearings including pressure distributions, velocity distributions, film thickness, load capacity, flow rate, shear force, and friction coefficient is also derived analytically for various ξ, flow indices (n, and outlet film thicknesses (H0. These analytical solutions are clear to find the effects of the operation parameters rather than numerical methods. It can be simply and fast used for engineers. Subsequently, these proposed analytical solutions are used to analyze the lubrication performance of slider bearing with the power-law fluids.

  6. The occurrence of alien plant species in field margins in Finland

    OpenAIRE

    Jauni, Miia; Hyvönen, Terho

    2009-01-01

    The results suggest that alien plant species comprise an important part of the biodiversity of Finnish field margins and semi-natural agricultural habitats. The role of field margins as dispersal corridors for invasive alien plants is limited for certain species.

  7. The biological invasion in Albania

    Directory of Open Access Journals (Sweden)

    JULIAN SHEHU

    2014-06-01

    Full Text Available Albania, whose territory comprises many types of habitats and is characterized by a rich biological diversity, is particularly vulnerable to the threats posed by alien invasive species. The spread of invasive alien species is creating complex and far-reaching challenges that threaten both the natural biological riches of the earth and the well-being of our people. While the problem is global, the nature and severity of the impacts on society, economic life, health, and natural heritage are distributed unevenly across nations and regions. Some aspects of the global invasive alien species (IAS problem require solutions tailored to the specific values, needs, and priorities of nations while others call for consolidated action by the larger world community. Preventing the international movement of invasive alien species and coordinating a timely and effective response to invasions requires cooperation and collaboration among governments, economic sectors, non-governmental organizations, and international treaty organizations. Many features have been attributed to invasive species and invaded ecosystems, but none are universal and invasive species tend to have a suite of traits rather than all of themThe large numbers of alien organisms introduced into Albania do not generally endanger the biodiversity on a large scale.

  8. The problematic of the geographical expansion of invasive alien species. Analysis and distribution of two species in the province of Avila and initiatives for the minimization of their effects; La problematica de la expansion geografica de las especies exoticas invasoras. Analisis y distribucion de dos especies en la provincia de Avila e iniciativas para la minimizacion de sus efectos

    Energy Technology Data Exchange (ETDEWEB)

    Garcia Quiroga, F.

    2012-07-01

    Invasive alien species currently constitute a serious threat for biodiversity and large economic losses. The risks associated to its introduction are in constant growth due to the increase of trade, tourism, transport and market globalization. Examples of these species can be found in the fauna such as the red swamp or Louisiana crawfish and in the flora as the ailanthus, which affect a great deal of the Spanish provinces, as that of Avila where they will be analyzed in greater detail. Because of it, the development of an effective action against its invasion through a series of measures, as well as the development and implementation of a legal framework, in addition to the information of the citizens are essential aspects for eradication or to mitigate its expansion. (Author)

  9. Prediction of potential invasion range of alien plant Peperomia pellucida in China%外来入侵植物草胡椒在我国的潜分布范围预测

    Institute of Scientific and Technical Information of China (English)

    董旭; 陈秀芝; 娄玉霞; 郭水良

    2013-01-01

    Summary In recent years,new alien plants have constantly been invading China as a result of an increase of foreign exchanges.Peperomia pellucida (L.) Kunth,a species that originated from tropical America,is one of the alien species recently found in Shanghai.Its potential geographical distribution range and habitats of the species are still unknown.Scientists have applied a variety of ecological niche models to predict the risk of exotic plant invasions in China.Among these ecological niche models,maximum entropy (MaxEnt) model has higher accuracy of predicted results with small sample size. According to 12 environmental variables from the global climate environment database (http://www. worldclim.org/) and 649 occurrence records of P.pellucida in the world from the global biodiversity database (http://data.gbif.org/welcome.htm) and the Chinese Virtual Herbarium (http://www.cvh.org.cn/cms/),a prediction of P.pellucida potential distribution was conducted using MaxEnt model and ArcGis 9.3 software.In this prediction,12 environmental variables were used,including precipitation of wettest month,mean diurnal temperature range,isothermality,precipitation of warmest quarter,mean temperature of coldest quarter,variance in precipitation seasonality,precipitation of coldest quarter,temperature annual range,altitude,precipitation of driest month,mean temperature of warmest quarter,and mean temperature of driest quarter.When modeling,the occurrence data and environmental variables were firstly imported into the MaxEnt,and 75% of the occurrence data to predict the risk(training data)and the other(testing data)to test the accuracy were used.The raster layer of P.pellucida was gotten in the global potential distribution in ASCII format,then was imported into ArcGis for further analyses,and the potential suitable areas of P.pellucida in China was gotten.Finally,the result was confirmed by the ROC(receiver operating characteristics) curve analytical method,and the AUC(area under

  10. Alien Plant Invasion Situation in “Two Lakes and One Reservoir” Ecological Functional Area of Guiyang and Prevention Measures%贵阳市两湖一库生态功能区植物入侵情况及防范措施

    Institute of Scientific and Technical Information of China (English)

    石登红; 李灿

    2011-01-01

    为了解贵阳市外来入侵生物情况,对红枫湖、百花湖和阿哈水库的主要入侵植物进行了调查.结果表明:贵阳市红枫湖、百花湖和阿哈水库生态功能区外来入侵植物有52种,隶属于20科.入侵种以菊科最多,为15种;其次是苋科和豆科,分别为4种和6种.有28种入侵种来源于美洲,其他种来源于欧洲、亚洲、非洲等地区.有入侵行为的39种外来植物大部分属于田间杂草.并针对入侵植物的种类组成、入侵途径及危害程度等提出了相应的防范措施.%Results from investigation of alien invasive plants in “two lakes and one reservoir” ecological functional area of Guiyang showed that there were 51 plant species belonging to 20 families in the area, 15,4,and 6 species of which belonged to Compositae,Amarantaceae and Leguminosae,respectively. 28 species of them originated from America and others from Europe,Asia and Africa. Most of the 39 alien plants were field weeds. The prevention measures were proposed aiming at the composition, invading way and extent of injury of alien invasive plants.

  11. Review of alien marine macrophytes in Tunisia

    Directory of Open Access Journals (Sweden)

    Y. R. SGHAIER

    2014-06-01

    Full Text Available In the present study, the list of alien marine macrophytes introduced into Tunisia was updated in the light of available data and new observations. A total of 27 alien marine macrophytes have been recorded so far from Tunisia: 18 Rhodophyta, 3 Ochrophyta, 5 Chlorophyta and 1 Magnoliophyta. For each species, the locality (-ies, the year (or period and the source of the first observation in Tunisia are given. The distribution and the status (casual, cryptogenic, established or questionable of species in Tunisia were evaluated and, where appropriate, discussed. Among them, Hypnea cornuta is reported for the first time from Tunisia. Fourteen alien marine macrophytes are established, whereas seven cryptogenic and two casual species require further investigation. Eleven species are considered as invasive or potentially invasive in the Mediterranean Sea: Acrothamnion preissii, Asparagopsis armata, A. taxiformis Indo-Pacific lineage, Hypnea cornuta, Lophocladia lallemandii, Womersleyella setacea, Caulerpa chemnitzia, C. cylindracea, C. taxifolia, Codium fragile subsp. fragile and Halophila stipulacea. Finally, the case of four questionable species is also discussed.

  12. Inventory of alien marine species of Cyprus (2009

    Directory of Open Access Journals (Sweden)

    S. KATSANEVAKIS

    2012-12-01

    Full Text Available An updated inventory of alien marine species from coastal and offshore waters of Cyprus is presented. Records were compiled based on the existing scientific and grey literature, including HCMR database of Mediterranean alien species, technical reports, scientific congresses, academic dissertations, and websites, as well as on unpublished/personal observations. The listed species were classified in one of five categories: established, invasive, casual, cryptogenic, and questionable. The mode of introduction and the year of first sighting were also reported for each species. Eight new records based on personal observations of the authors were reported (Chondria coerulescens, Neosiphonia sphaerocarpa, Enchelycore anatina, Lagocephalus spadiceus, Lagocephalus suezensis, Scomberomorus commerson, Sillago sihama, and Sphoeroides pachygaster. Nine species, previously reported as aliens in Cypriot waters, were excluded from the inventory for various reasons. Ten established species were characterized as invasive (Caulerpa racemosa var. cylindracea, Cerithium scabridum, Strombus persicus, Trochus erythraeus, Brachidontes pharaonis, Pinctada radiata, Fistularia commersonii, Lagocephalus sceleratus, Siganus luridus, and Siganus rivulatus as they have a substantial impact on biodiversity and/or local economy. The impact of alien marine species in Cyprus is expected to grow in the close future, and further effort directed towards recording alien invasions and their impact will be needed.

  13. 8 CFR 211.5 - Alien commuters.

    Science.gov (United States)

    2010-01-01

    ... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Alien commuters. 211.5 Section 211.5 Aliens...: IMMIGRANTS; WAIVERS § 211.5 Alien commuters. (a) General. An alien lawfully admitted for permanent residence.... An alien commuter engaged in seasonal work will be presumed to have taken up residence in the...

  14. Sensing and Identification of Nonlinear Dynamics of Slider with Clearance in Sub-5 Nanometer Regime

    Directory of Open Access Journals (Sweden)

    Gang Sheng

    2011-01-01

    Full Text Available This paper provides an overview of the problems pertaining to the sensing and identification of nonlinear dynamics of slider with clearance in sub-5 nanometer regime. This problem is complex in nature because the nonlinear dynamics of slider in sub-5 nanometer clearance regime involves different sources of nonlinear, nonstationary, and uncertainty characteristics. For example, the involved forces such as air-bearing force, intermolecular force, and contact forces are all nonlinear. The complex interface interaction with mobile lubricant makes the slider response be nonstationary. Furthermore, the interfacial parameters are available only by assumptions in the sense of statistics. Most of the reported studies either focused on physics-based simulations by using assumed interfacial parameters or focused on experimental characterization. The issues of the sensing and identification of the nonlinear dynamic properties of slider in nanometer clearance regime will be discussed with an aim at illustrating the promising approaches for improving the correlation between test data and physics-based simulations.

  15. Optimization of thermal fly-height control slider geometry for Tbit/in^2 recording

    NARCIS (Netherlands)

    Vakis, Antonis I.; Polycarpou, Andreas A.

    2010-01-01

    Magnetic storage advances including thermal fly-height control (TFC) technology were able to reduce the clearance between the read/write elements of the slider and the disk surface to increase the recording density of hard disk drives without compromising the stability of the head–disk interface (HD

  16. Footprints of alien technology

    Science.gov (United States)

    Davies, P. C. W.

    2012-04-01

    If alien civilizations do, or did, exist, their technology will impact their environment. Some consideration has been given to the detection of large-scale astro-engineering, such as Dyson spheres. However, a very advanced technology might leave more subtle footprints requiring sophisticated scientific methods to uncover. We must not overlook the possibility that alien technology has impacted our immediate astronomical environment, even Earth itself, but probably a very long time ago. This raises the question of what traces, if anything, might remain today. I shall consider the possibilities of biological, geological and physical traces, and suggest ways that we might search for them.

  17. Five-DOF innovative linear MagLev slider to account for pitch, tilt and load uncertainty

    Science.gov (United States)

    Kao, Yi-Ming; Tsai, Nan-Chyuan; Chiu, Hsin-Lin

    2017-02-01

    This paper is focused at position deviation regulation upon a slider by Fuzzy Sliding Mode Control (FSMC). Five Degrees Of Freedom (DOF) of position deviation are required to be regulated except for the direction (i.e., X-axis) in which the slider moves forward and backward. Totally 8 sets of Magnetic Actuators (MAs) and an Electro-Pneumatic Transducer (EPT) are employed to drive the slider carrying loads under the commands of FSMC. EPT is applied to adjust the pressure of compressed air to counterbalance the weight of slider itself. At first, the system dynamic model of slider, including load uncertainty and load position uncertainty, is established. Intensive computer simulations are undertaken to verify the validity of proposed control strategy. Finally, a prototype of realistic slider position deviation regulation system is successfully built up. According to the experiments by cooperation of pneumatic and magnetic control, the actual linear position deviations of slider can be regulated within ±8 μm and angular position deviations within ±1 mini-degrees. From the viewpoint of energy consumption, the applied currents to 8 sets of MAs are all below 1.2 A. To sum up, the closed-loop levitation system by cooperation of pneumatic and magnetic control is capable to account for load uncertainty and uncertainty of the standing position of load to be carried.

  18. The cobblers stick to their lasts : pollinators prefer native over alien plant species in a multi-species experiment

    OpenAIRE

    Chrobock, Thomas; Winiger, Pius; Fischer, Markus; van Kleunen, Mark

    2013-01-01

    The majority of plant species rely, at least partly, on animals for pollination. Our knowledge on whether pollinator visitation differs between native and alien plant species, and between invasive and non-invasive alien species is still limited. Additionally, because numerous invasive plant species are escapees from horticulture, the transition from human-assisted occurrence in urbanized habitats to unassisted persistence and spread in (semi-)natural habitats requires study. To address whethe...

  19. The legitimacy of alien rulers

    DEFF Research Database (Denmark)

    Horne, Christine; Ben-Nun Bloom, Pazit; Irwin, Kyle

    2016-01-01

    In the modern world, alien rulers are generally perceived to lack legitimacy. Political legitimacy is important because it is thought to be the principal alternative to coercive institutions. Little empirical evidence supports these claims, however. We devise a laboratory experiment that isolates...... alienness from other ruler characteristics. The experiment tests whether alien rulers have less legitimacy than native rulers, and whether the ability to punish compensates for this disadvantage. Using American and Israeli college student samples, we find that alien rulers receive less compliance than...... native rulers, and that the ability to punish does not allow alien rulers to “catch-up” with native rulers....

  20. Alien Life Imagined

    Science.gov (United States)

    Brake, Mark

    2012-11-01

    1. Kosmos: aliens in ancient Greece; 2. The world turned upside down: Copernicanism and the voyages of discovery; 3. In Newton's train: pluralism and the system of the world; 4. Extraterrestrials in the early machine age; 5. After Darwin: the war of the worlds; 6. Einstein's sky: life in the new universe; 7. Ever since SETI: astrobiology in the space age; References; Index.

  1. The Origins of Alienation

    Science.gov (United States)

    Bronfenbrenner, Urie

    1974-01-01

    Evolutionary changes in the structure of the American family have led to an increase in the estrangement between young people and adults in the United States. The role of day care services, peer groups, schools, the community, and the organization of work are discussed in terms of their contribution to this alienation as well as possible changes…

  2. Forgetting and remembering alienation theory.

    Science.gov (United States)

    Yuill, Chris

    2011-01-01

    Alienation theory has acted as the stimulus for a great deal of research and writing in the history of sociology. It has formed the basis of many sociological "classics" focused on the workplace and the experiences of workers, and has also been mobilized to chart wider social malaise and individual troubles. Alienation theory usage has, however, declined significantly since its heyday of the 1960s and 1970s. Here, the reasons why alienation theory was "forgotten" and what can be gained by "remembering" alienation theory are explored. to realize this ambition this article proceeds by (1) briefly visiting differing definitions of alienation theory, before charting its high point, and the various debates and tensions of the time, during the 1960s and 1970s; (2) analysing the reasons why alienation theory fell from grace from the 1980s onwards; (3) elaborating how and why alienation theory is still relevant for sociology and the wider social sciences today.

  3. Variation in the strength of reproductive interference from an alien congener to a native species in Taraxacum.

    Science.gov (United States)

    Nishida, Sachiko; Hashimoto, Keisuke; Kanaoka, Masahiro M; Takakura, Ko-Ichi; Nishida, Takayoshi

    2017-01-01

    Reproductive interference (RI) may be a contributing factor to the displacement of native species by an alien congener, and RI strength has been shown theoretically to affect distributional relationships between species. Thus, variations in RI strength from alien to native species result in different consequences of invasions and efforts to conserve native species, but the variations have seldom been examined empirically. We therefore investigated RI strength variations from the alien species Taraxacum officinale and its hybrids to eight populations of native dandelions, four T. japonicum populations and two populations each of two subspecies of T. platycarpum. We examined the association between alien relative abundance and native seed set in field surveys, and we also performed hand-pollination experiments to investigate directly the sensitivity of native flowers to alien pollen. We found that the effect of alien relative abundance on native seed set of even the same native species could differ greatly in different regions, and that the sensitivity of native flowers to alien pollen was also dependent on region. Our results, together with those of previous studies, show that RI from the alien to the native species is strong in regions where the alien species outnumbers the native species and marginal where it does not; this result suggests that alien RI can critically affect distributional relationships between native and alien species. Our study highlights the importance of performing additional empirical investigations of RI strength variation and of giving due attention to alien RI in efforts to conserve regional native biodiversity.

  4. Considerations of Building up a Supervision and Management System for Prevention and Control of Invasive Alien Species Posing Environmental Hazards in China%关于构建我国外来入侵物种环境危害防控监督管理体系的思考

    Institute of Scientific and Technical Information of China (English)

    丁晖; 马方舟; 吴军; 雷军成; 乐志芳; 徐海根

    2015-01-01

    外来入侵物种是造成全球生物多样性丧失的主要威胁因素,我国是世界上受外来入侵物种危害最严重的国家之一。近年来,我国外来入侵物种的发生态势出现重大变化,呈现出许多新特点,但现行管理制度不健全,管理策略不完善,技术支撑薄弱,管理能力不强。要建立以环境危害防控为目标的管理体系,形成“引进—建立种群—传播扩散—发生危害”过程中的“无缝”监管,提高防控措施的技术水平和综合运用能力。研究提出了与此相适应的管理框架、管理目标、管理范围、管理对象、基本原则、主要制度和措施,初步形成了我国外来入侵物种环境危害防控监督管理体系的构建方案。%Invasive alien species are major threats to biodiversity at the global level. China is among the countries most af⁃fected by invasive alien species. Especially in recent years, the situation has changed greatly, displaying a number of new characteristics. In coping with the changing situation, it is found that the governance system is incomplete, management strategy imperfect, technological support inadequate and management capacity insufficient in the country. It is, therefore, essential and critical to build up an environment⁃hazard⁃control⁃oriented holistic governance system, a“seamless” supervi⁃sion network over the entire process of“introduction⁃population⁃establishment⁃dissimilation and proliferation⁃hazard forma⁃tion”, and a set of control measures high in technical level and comprehensive applicability. To address the issue, a holis⁃tic governance system is brought forth, that including framework, targets, scope, objects, fundamental principles, main institutions and measures, which tentatively form a program for building up a supervision and management system for pre⁃vention and control of invasive alien species posing environmental hazards.

  5. Cardan gear mechanism versus slider-crank mechanism in pumps and engines

    Energy Technology Data Exchange (ETDEWEB)

    Karhula, J.

    2008-07-01

    In machine design we always want to save space, save energy and produce as much power as possible. We can often reduce accelerations, inertial loads and energy consumption by changing construction. In this study the old cardan gear mechanism (hypocycloid mechanism) has been compared with the conventional slider-crank mechanism in air pumps and four-stroke engines. Comprehensive Newtonian dynamics has been derived for the both mechanisms. First the slidercrank and the cardan gear machines have been studied as lossless systems. Then the friction losses have been added to the calculations. The calculation results show that the cardan gear machines can be more efficient than the slider-crank machines. The smooth running, low mass inertia, high pressures and small frictional power losses make the cardan gear machines clearly better than the slider-crank machines. The dynamic tooth loads of the original cardan gear construction do not rise very high when the tooth clearances are kept tight. On the other hand the half-size crank length causes high bearing forces in the cardan gear machines. The friction losses of the cardan gear machines are generally quite small. The mechanical efficiencies are much higher in the cardan gear machines than in the slider-crank machines in normal use. Crankshaft torques and power needs are smaller in the cardan gear air pumps than in the equal slider-crank air pumps. The mean crankshaft torque and the mean output power are higher in the cardan gear four-stroke engines than in the slider-crank four-stroke engines in normal use. The cardan gear mechanism is at its best, when we want to build a pump or an engine with a long connecting rod (approx 5.crank length) and a thin piston (approx 1.5.crank length) rotating at high angular velocity and intermittently high angular acceleration. The cardan gear machines can be designed also as slide constructions without gears. Suitable applications of the cardan gear machines are three-cylinder half

  6. Alien plant dynamics following fire in mediterranean-climate California shrublands

    Science.gov (United States)

    Keeley, J.E.; Baer-Keeley, M.; Fotheringham, C.J.

    2005-01-01

    Over 75 species of alien plants were recorded during the first five years after fire in southern California shrublands, most of which were European annuals. Both cover and richness of aliens varied between years and plant association. Alien cover was lowest in the first postfire year in all plant associations and remained low during succession in chaparral but increased in sage scrub. Alien cover and richness were significantly correlated with year (time since disturbance) and with precipitation in both coastal and interior sage scrub associations. Hypothesized factors determining alien dominance were tested with structural equation modeling. Models that included nitrogen deposition and distance from the coast were not significant, but with those variables removed we obtained a significant model that gave an R2 = 0.60 for the response variable of fifth year alien dominance. Factors directly affecting alien dominance were (1) woody canopy closure and (2) alien seed banks. Significant indirect effects were (3) fire intensity, (4) fire history, (5) prefire stand structure, (6) aridity, and (7) community type. According to this model the most critical factor influencing aliens is the rapid return of the shrub and subshrub canopy. Thus, in these communities a single functional type (woody plants) appears to the most critical element controlling alien invasion and persistence. Fire history is an important indirect factor because it affects both prefire stand structure and postfire alien seed banks. Despite being fire-prone ecosystems, these shrublands are not adapted to fire per se, but rather to a particular fire regime. Alterations in the fire regime produce a very different selective environment, and high fire frequency changes the selective regime to favor aliens. This study does not support the widely held belief that prescription burning is a viable management practice for controlling alien species on semiarid landscapes. ?? 2005 by the Ecological Society of

  7. 8 CFR 232.3 - Arriving aliens.

    Science.gov (United States)

    2010-01-01

    ... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Arriving aliens. 232.3 Section 232.3 Aliens and Nationality DEPARTMENT OF HOMELAND SECURITY IMMIGRATION REGULATIONS DETENTION OF ALIENS FOR PHYSICAL AND MENTAL EXAMINATION § 232.3 Arriving aliens. When a district director has reasonable...

  8. 8 CFR 244.4 - Ineligible aliens.

    Science.gov (United States)

    2010-01-01

    ... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Ineligible aliens. 244.4 Section 244.4 Aliens and Nationality DEPARTMENT OF HOMELAND SECURITY IMMIGRATION REGULATIONS TEMPORARY PROTECTED STATUS FOR NATIONALS OF DESIGNATED STATES § 244.4 Ineligible aliens. An alien is ineligible for...

  9. 8 CFR 236.13 - Ineligible aliens.

    Science.gov (United States)

    2010-01-01

    ... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Ineligible aliens. 236.13 Section 236.13 Aliens and Nationality DEPARTMENT OF HOMELAND SECURITY IMMIGRATION REGULATIONS APPREHENSION AND DETENTION OF INADMISSIBLE AND DEPORTABLE ALIENS; REMOVAL OF ALIENS ORDERED REMOVED Family Unity Program §...

  10. 22 CFR 41.71 - Transit aliens.

    Science.gov (United States)

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Transit aliens. 41.71 Section 41.71 Foreign... NATIONALITY ACT, AS AMENDED Transit Aliens § 41.71 Transit aliens. (a) Transit aliens—general. An alien is classifiable as a nonimmigrant transit alien under INA 101(a) (15) (C) if the consular officer is...

  11. DOUBLE FOUR-BAR CRANK-SLIDER MECHANISM DYNAMIC BALANCING BY META-HEURISTIC ALGORITHMS

    Directory of Open Access Journals (Sweden)

    Habib Emdadi

    2013-09-01

    Full Text Available In this paper, a new method for dynamic balancing of double four-bar crank slider mechanism by metaheuristic-based optimization algorithms is proposed. For this purpose, a proper objective function which is necessary for balancing of this mechanism and corresponding constraints has been obtained by dynamic modeling of the mechanism. Then PSO, ABC, BGA and HGAPSO algorithms have been applied for minimizing the defined cost function in optimization step. The optimization results have been studied completely by extracting the cost function, fitness, convergence speed and runtime values of applied algorithms. It has been shown that PSO and ABC are more efficient than BGA and HGAPSO in terms of convergence speed and result quality. Also, a laboratory scale experimental doublefour-bar crank-slider mechanism was provided for validating the proposed balancing method practically.

  12. Double Four-Bar Crank-Slider Mechanism Dynamic Balancing by Meta-Heuristic Algorithms

    Directory of Open Access Journals (Sweden)

    Habib Emdadi

    2013-09-01

    Full Text Available In this paper, a new method for dynamic balancing of double four-bar crank slider mechanism by meta-heuristic-based optimization algorithms is proposed. For this purpose, a proper objective function which is necessary for balancing of this mechanism and corresponding constraints has been obtained by dynamic modeling of the mechanism.Then PSO, ABC, BGA and HGAPSO algorithms have been applied for minimizing the defined cost function in optimization step. The optimization results have been studied completely by extracting the cost function, fitness, convergence speed and run time values of applied algorithms. It has been shown that PSO and ABC are more efficient than BGA and HGAPSO in terms of convergence speed and result quality. Also, a laboratory scale experimental double four-bar crank-slider mechanism was provided for validating the proposedbalancing method practicall

  13. Optical properties of alumina titanium carbide sliders used in rigid disk drives.

    Science.gov (United States)

    de Groot, P

    1998-10-01

    A common material for read-write sliders is a composite of alumina (Al(2)O(3)) and titanium carbide (TiC), with a grain size of the order of 1 mum. I derive the effective complex reflectivity of this material, using scalar diffraction theory and the known indices of refraction of Al(2)O(3) and TiC. The effective reflectivity is a function of the relative surface area of the exposed TiC grains as well as of the numerical aperture of the collection optics. The theory resolves several known discrepancies between ellipsometry and reflectometry of Al(2)O(3)-TiC. The theory also predicts a systematic error in the phase shift on reflection calculation. These results are of considerable interest for surface shape metrology of the slider as well as for optical flying-height testing and control of pole-tip recession.

  14. Finding and Exploring Health Information with a Slider-Based User Interface.

    Science.gov (United States)

    Pang, Patrick Cheong-Iao; Verspoor, Karin; Pearce, Jon; Chang, Shanton

    2016-01-01

    Despite the fact that search engines are the primary channel to access online health information, there are better ways to find and explore health information on the web. Search engines are prone to problems when they are used to find health information. For instance, users have difficulties in expressing health scenarios with appropriate search keywords, search results are not optimised for medical queries, and the search process does not account for users' literacy levels and reading preferences. In this paper, we describe our approach to addressing these problems by introducing a novel design using a slider-based user interface for discovering health information without the need for precise search keywords. The user evaluation suggests that the interface is easy to use and able to assist users in the process of discovering new information. This study demonstrates the potential value of adopting slider controls in the user interface of health websites for navigation and information discovery.

  15. Floristic analysis and distribution pattern of alien plants in Shandong Province,eastern China

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Alien plants,along with their ecological invasion and negative impacts on indigenous species diversity and ecosystems,are one of the major topics of current ecological research.The background investigation and floristic analysis of alien plants are very important and form an essential database for invasive species research,control and management.In our study these alien plants,mainly collected from the Flora of Shandong Province,combined with a field survey,were studied and analyzed.We also established a floristic database.Our findings are as follows:1) there are a total of 827 alien species,belonging to 122 families and 416 genera of which 348 species were imported from other countries;2) a high proportion,39.0% of the flora in Shandong Province,is accounted for by alien species,of which 21 dominant families largely belong to the Rosaceae,Leguminosae,Asteraceae and Gramineae;3) the diverse geographical distribution of the genera is characterized by species dominant in the temperate zone which accounts for 52.5% of the alien plants and 44.1% of the plants from the tropics;4) the origins of alien species and their centralized distribution in Shandong together show the anthropogenic effect and unnatural impacts on the environment and 5) in Shandong Province,alien plants originate more from temperate zones than from any other areas of the world.

  16. The alien hand syndrome

    Science.gov (United States)

    Panikkath, Deepa; Mojumder, Deb; Nugent, Kenneth

    2014-01-01

    A 77-year-old woman presented with the complaint of observing her left hand moving without her knowledge while watching television. Her left hand stroked her face and hair as if somebody was controlling it. These movements lasted only half an hour but on recovery, she had left hemiparesis. Alien hand syndrome as the presentation of cardioembolic stroke is extremely rare but can be terrifying to patients. PMID:24982566

  17. Alien Introgression in Wheat

    OpenAIRE

    Molnár-Láng, M.; Ceoloni, C; Doležel, J

    2015-01-01

    This book provides an overview of the latest advancements in the field of alien introgression in wheat. The discovery and wide application of molecular genetic techniques including molecular markers, in situ hybridization, and genomics has led to a surge in interspecific and intergeneric hybridization in recent decades. The work begins with the taxonomy of cereals, especially of those species which are potential gene sources for wheat improvement. The text then goes on to cover.

  18. A Letter to Alien

    Institute of Scientific and Technical Information of China (English)

    邱政榜

    2012-01-01

    Dear Alien, 1 am sorry to hear that you have some problems. I hear you argued with your best friend. 1 think you could call him up or go to his home. You could write him a letter. And you could tell him you are sony. Or maybe you could give him a ticket to a ball game. I am sure you will get on well with him again.

  19. Captured by Aliens

    Science.gov (United States)

    Achenbach, Joel

    2000-03-01

    Captured by Aliens is a long and twisted voyage from science to the supernatural and back again. I hung out in Roswell, N.M., spent time with the Mars Society, met a guy who was figuring out the best way to build a spaceship to go to Alpha Centauri. I visited the set of the X-Files and talked to Mulder and Scully. One day over breakfast I was told by NASA administrator Dan Goldin, We live in a fog, man! He wants the big answers to the big questions. I spent a night in the base of a huge radio telescope in the boondocks of West Virginia, awaiting the signal from the aliens. I was hypnotized in a hotel room by someone who suspected that I'd been abducted by aliens and that this had triggered my interest in the topic. In the last months of his life, I talked to Carl Sagan, who believed that the galaxy riots with intelligent civilizations. He's my hero, for his steadfast adherence to the scientific method. What I found in all this is that the big question that needs immediate attention is not what's out THERE, but what's going on HERE, on Earth, and why we think the way we do, and how we came to be here in the first place.

  20. Bark beetles and pinhole borers (Curculionidae, Scolytinae, Platypodinae alien to Europe

    Directory of Open Access Journals (Sweden)

    Lawrence Kirkendall

    2010-09-01

    Full Text Available Invasive bark beetles are posing a major threat to forest resources around the world. DAISIE’s web-based and printed databases of invasive species in Europe provide an incomplete and misleading picture of the alien scolytines and platypodines. We present a review of the alien bark beetle fauna of Europe based on primary literature through 2009. We find that there are 18 Scolytinae and one Platypodinae species apparently established in Europe, from 14 different genera. Seventeen species are naturalized. We argue that Trypodendron laeve, commonly considered alien in Europe, is a native species; conversely, we hypothesize that Xyleborus pfeilii, which has always been treated as indigenous, is an alien species from Asia. We also point out the possibility that the Asian larch bark beetle Ips subelongatus is established in European Russia. We show that there has been a marked acceleration in the rate of new introductions to Europe, as is also happening in North America: seven alien species were first recorded in the last decade. We present information on the biology, origins, and distributions of the alien species. All but four are polyphagous, and 11 are inbreeders: two traits which increase invasiveness. Eleven species are native to Asia, six to the Americas, and one is from the Canary Islands. The Mediterranean is especially favorable for invasives, hosting a large proportion of the aliens (8/18. Italy, Spain and France have the largest numbers of alien species (15, 10 and 7 respectively. We point out that the low numbers for at least some countries is likely due to under-reporting. Finally, we discuss the difficulties associated with identifying newly invasive species. Lack of good illustrations and keys hinder identification, particularly for species coming from Asia and Oceania.

  1. Environmental and economic impact of alien terrestrial arthropods in Europe

    Directory of Open Access Journals (Sweden)

    Sibylle Vaes-Petignat

    2014-06-01

    Full Text Available In the last decades abundance and importance of invasive alien species has grown continuously due to the undiminished growth of global trade. In most cases, arthropod introductions were unintended and occurred as hitchhikers or contaminants. Alien arthropods can have significant environmental impacts and can be economically costly. To measure these impacts, we expand the generic impact scoring system initially developed for mammals and birds, and applied it to terrestrial arthropods. The scoring of the 77 most widely distributed arthropod species alien to Europe revealed the mite Varroa destructor as the most harmful species, followed by the Chinese longhorn beetle Anoplophora chinensis and the Argentine ant Linepithema humile. The highest environmental impact is through herbivory, disease transmission, and ecosystem impacts. The highest economic impact is on agriculture and human infrastructure. The generic impact scoring system allows comparing impact scores of vertebrates and arthropods, thus serving as a background for decision making processes of policies and stakeholders.

  2. No saturation in the accumulation of alien species worldwide.

    Science.gov (United States)

    Seebens, Hanno; Blackburn, Tim M; Dyer, Ellie E; Genovesi, Piero; Hulme, Philip E; Jeschke, Jonathan M; Pagad, Shyama; Pyšek, Petr; Winter, Marten; Arianoutsou, Margarita; Bacher, Sven; Blasius, Bernd; Brundu, Giuseppe; Capinha, César; Celesti-Grapow, Laura; Dawson, Wayne; Dullinger, Stefan; Fuentes, Nicol; Jäger, Heinke; Kartesz, John; Kenis, Marc; Kreft, Holger; Kühn, Ingolf; Lenzner, Bernd; Liebhold, Andrew; Mosena, Alexander; Moser, Dietmar; Nishino, Misako; Pearman, David; Pergl, Jan; Rabitsch, Wolfgang; Rojas-Sandoval, Julissa; Roques, Alain; Rorke, Stephanie; Rossinelli, Silvia; Roy, Helen E; Scalera, Riccardo; Schindler, Stefan; Štajerová, Kateřina; Tokarska-Guzik, Barbara; van Kleunen, Mark; Walker, Kevin; Weigelt, Patrick; Yamanaka, Takehiko; Essl, Franz

    2017-02-15

    Although research on human-mediated exchanges of species has substantially intensified during the last centuries, we know surprisingly little about temporal dynamics of alien species accumulations across regions and taxa. Using a novel database of 45,813 first records of 16,926 established alien species, we show that the annual rate of first records worldwide has increased during the last 200 years, with 37% of all first records reported most recently (1970-2014). Inter-continental and inter-taxonomic variation can be largely attributed to the diaspora of European settlers in the nineteenth century and to the acceleration in trade in the twentieth century. For all taxonomic groups, the increase in numbers of alien species does not show any sign of saturation and most taxa even show increases in the rate of first records over time. This highlights that past efforts to mitigate invasions have not been effective enough to keep up with increasing globalization.

  3. Aliens on Earth. Are reports of close encounters correct?

    CERN Document Server

    Sobkowicz, Pawel

    2012-01-01

    Popular culture (movies, SF literature) and witness accounts of close encounters with extraterrestrials provide a rather bizarre image of Aliens behavior on Earth. It is far from stereotypes of human space exploration. The reported Aliens are not missions of diplomats, scientists nor even invasion fleets; typical encounters are with lone ETs (or small groups), and involve curious behavior: abductions and experiments (often of sexual nature), cattle mutilations, localized killing and mixing in human society using various methods. Standard scientific explanations of these social memes point to influence of cultural artifacts (movies, literature) on social imagination, projection of our fears and observations of human society, and, in severe cases, psychic disorder of the involved individuals. In this work we propose an alternate explanation, claiming that the memes might be the result of observations of actual behavior of true Aliens, who, visiting Earth behave in a way that is then reproduced by such memes. Th...

  4. No saturation in the accumulation of alien species worldwide

    Science.gov (United States)

    Seebens, Hanno; Blackburn, Tim M.; Dyer, Ellie E.; Genovesi, Piero; Hulme, Philip E.; Jeschke, Jonathan M.; Pagad, Shyama; Pyšek, Petr; Winter, Marten; Arianoutsou, Margarita; Bacher, Sven; Blasius, Bernd; Brundu, Giuseppe; Capinha, César; Celesti-Grapow, Laura; Dawson, Wayne; Dullinger, Stefan; Fuentes, Nicol; Jäger, Heinke; Kartesz, John; Kenis, Marc; Kreft, Holger; Kühn, Ingolf; Lenzner, Bernd; Liebhold, Andrew; Mosena, Alexander; Moser, Dietmar; Nishino, Misako; Pearman, David; Pergl, Jan; Rabitsch, Wolfgang; Rojas-Sandoval, Julissa; Roques, Alain; Rorke, Stephanie; Rossinelli, Silvia; Roy, Helen E.; Scalera, Riccardo; Schindler, Stefan; Štajerová, Kateřina; Tokarska-Guzik, Barbara; van Kleunen, Mark; Walker, Kevin; Weigelt, Patrick; Yamanaka, Takehiko; Essl, Franz

    2017-01-01

    Although research on human-mediated exchanges of species has substantially intensified during the last centuries, we know surprisingly little about temporal dynamics of alien species accumulations across regions and taxa. Using a novel database of 45,813 first records of 16,926 established alien species, we show that the annual rate of first records worldwide has increased during the last 200 years, with 37% of all first records reported most recently (1970–2014). Inter-continental and inter-taxonomic variation can be largely attributed to the diaspora of European settlers in the nineteenth century and to the acceleration in trade in the twentieth century. For all taxonomic groups, the increase in numbers of alien species does not show any sign of saturation and most taxa even show increases in the rate of first records over time. This highlights that past efforts to mitigate invasions have not been effective enough to keep up with increasing globalization. PMID:28198420

  5. Functional differences between native and alien species : a global-scale comparison

    NARCIS (Netherlands)

    Ordonez, Alejandro; Wright, Ian J.; Olff, Han; Kitajima, Kaoru

    2010-01-01

    1. A prevalent question in the study of plant invasions has been whether or not invasions can be explained on the basis of traits. Despite many attempts, a synthetic view of multi-trait differences between alien and native species is not yet available. 2. We compiled a database of three ecologically

  6. Brechtian Alienation in Videogames

    Directory of Open Access Journals (Sweden)

    Daniel Joseph Dunne

    2014-11-01

    Full Text Available Immersion is constantly being broken in video games via the intrusion of mechanics and features that cause no end of distraction, breaking the player’s engagement in both the game’s narrative and in the gameplay. Yet these breaks are an integral part of games, whether through loading, saving or any other mechanical system that detracts from the playing the core game. These aren’t analysed as thoroughly as they could be in current game academia. However Bertolt Brecht’s “Verfremdungseffekt”, or distancing effect, provides a much needed foundation in the analysis of these sections within games that provoke a feeling of alienation.

  7. Poles Apart: Comparing Trends of Alien Hymenoptera in New Zealand with Europe (DAISIE.

    Directory of Open Access Journals (Sweden)

    Darren Ward

    Full Text Available Developing generalisations of invasive species is an important part of invasion biology. However, trends and generalisations from one part of the world may not necessarily hold elsewhere. We present the first inventory and analysis of all Hymenoptera alien to New Zealand, and compare patterns from New Zealand with those previously published from Europe (DAISIE. Between the two regions there was broad correlation between families with the highest number of alien species (Braconidae, Encyrtidae, Pteromalidae, Eulophidae, Formicidae, Aphelinidae. However, major differences also existed. The number of species alien to New Zealand is higher than for Europe (334 vs 286, and major differences include: i the much lower proportion of intentionally released species in New Zealand (21% vs 63% in Europe; and ii the greater proportion of unintentionally introduced parasitoids in New Zealand (71.2% vs 22.6%. The disharmonic 'island' nature of New Zealand is shown, as a high proportion of families (36% have no native representatives, and alien species also represent >10% of the native fauna for many other families. A much larger proportion of alien species are found in urban areas in New Zealand (60% compared to Europe (~30%, and higher numbers of alien species were present earlier in New Zealand (especially <1950. Differences in the origins of alien species were also apparent. Unlike Europe, the New Zealand data reveals a change in the origins of alien species over time, with an increasing dominance of alien species from Australasia (a regional neighbour during the past 25 years. We recommend that further effort be made towards the formation, and analysis, of regional inventories of alien species. This will allow a wider range of taxa and regions to be examined for generalisations, and help assess and prioritise the risk posed by certain taxa towards the economy or environment.

  8. Contrasting biogeography of endemic and alien terrestrial species in the Canary Islands

    OpenAIRE

    Vilà, Montserrat

    2006-01-01

    Endemics and alien organisms can be considered two faces of the same coin, since management of both groups of taxa have strongly interrelated conservation implications. Islands are rich in endemic species and are also very vulnerable to biological invasions. We analysed the biogeography and taxonomy of endemic and alien terrestrial species in the Canary Islands including fungi, lichens, bryophytes, vascular plants, arthropods, molluscs, annelids and vertebrates. By using the plant dataset we ...

  9. Structure design and establishment of database application system for alien species in Shandong Province, China

    Institute of Scientific and Technical Information of China (English)

    GUO Wei-hua; LIU Heng; DU Ning; ZHANG Xin-shi; WANG Ren-qing

    2007-01-01

    This paper presents a case study on structure design and establishment of database application system for alien species in Shandong Province, integrating with Geographic Information System, computer network, and database technology to the research of alien species. The modules of alien species database, including classified data input, statistics and analysis, species pictures and distribution maps,and out date input, were approached by Visual Studio.net 2003 and Microsoft SQL server 2000. The alien species information contains the information of classification, species distinction characteristics, biological characteristics, original area, distribution area, the entering fashion and route, invasion time, invasion reason, interaction with the endemic species, growth state, danger state and spatial information, i.e.distribution map. Based on the above bases, several models including application, checking, modifying, printing, adding and returning models were developed. Furthermore, through the establishment of index tables and index maps, we can also spatially query the data like picture,text and GIS map data. This research established the technological platform of sharing information about scientific resource of alien species in Shandong Province, offering the basis for the dynamic inquiry of alien species, the warning technology of prevention and the fast reaction system. The database application system possessed the principles of good practicability, friendly user interface and convenient usage. It can supply full and accurate information inquiry services of alien species for the users and provide functions of dynamically managing the database for the administrator.

  10. 28 CFR 21.3 - Aliens.

    Science.gov (United States)

    2010-07-01

    ... 28 Judicial Administration 1 2010-07-01 2010-07-01 false Aliens. 21.3 Section 21.3 Judicial Administration DEPARTMENT OF JUSTICE WITNESS FEES § 21.3 Aliens. (a) Aliens entitled to payment of $30 per day. The following aliens are entitled to witness fees and allowances provided in § 21.4: (1)...

  11. 8 CFR 1244.4 - Ineligible aliens.

    Science.gov (United States)

    2010-01-01

    ... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Ineligible aliens. 1244.4 Section 1244.4 Aliens and Nationality EXECUTIVE OFFICE FOR IMMIGRATION REVIEW, DEPARTMENT OF JUSTICE IMMIGRATION REGULATIONS TEMPORARY PROTECTED STATUS FOR NATIONALS OF DESIGNATED STATES § 1244.4 Ineligible aliens. An...

  12. 8 CFR 245a.32 - Ineligible aliens.

    Science.gov (United States)

    2010-01-01

    ... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Ineligible aliens. 245a.32 Section 245a.32 Aliens and Nationality DEPARTMENT OF HOMELAND SECURITY IMMIGRATION REGULATIONS ADJUSTMENT OF STATUS TO... IMMIGRATION AND NATIONALITY ACT LIFE Act Amendments Family Unity Provisions § 245a.32 Ineligible aliens....

  13. Dynamic Performance Characteristics of a Curved Slider Bearing Operating with Ferrofluids

    Directory of Open Access Journals (Sweden)

    Udaya P. Singh

    2012-01-01

    Full Text Available In the present theoretical investigation, the effect of ferrofluid on the dynamic characteristics of curved slider bearings is presented using Shliomis model which accounts for the rotation of magnetic particles, their magnetic moments, and the volume concentration in the fluid. The modified Reynolds equation for the dynamic state of the bearing is obtained. The results of dynamic stiffness and damping characteristics are presented. It is observed that the effect of rotation of magnetic particles improves the stiffness and damping capacities of the bearings.

  14. Feasibility of Open Tube Slider Growth of HgCdTe from Te-Rich Solution.

    Science.gov (United States)

    1980-02-01

    od of Equation (26), which assumes CdTe and HgTe molecules are dissolved in Te and that the solution is 3.2 percent less dense than the solid...finished slice is protected with a layer of beeswax and diced to the size of our slider system, either I 1Xlcm 2 or 2X3cm2 . Just before use, the...h time allowed for the solute to dissolve at 770’C produces ent with the annealing studies of Schrnt and Stelzer 1211 on 55 ’- IKIKE TRANSACTIONS ON

  15. Alien Hand Syndrome.

    Science.gov (United States)

    Hassan, Anhar; Josephs, Keith A

    2016-08-01

    Alien hand syndrome (AHS) is a rare disorder of involuntary limb movement together with a sense of loss of limb ownership. It most commonly affects the hand, but can occur in the leg. The anterior (frontal, callosal) and posterior variants are recognized, with distinguishing clinical features and anatomical lesions. Initial descriptions were attributed to stroke and neurosurgical operations, but neurodegenerative causes are now recognized as most common. Structural and functional imaging and clinical studies have implicated the supplementary motor area, pre-supplementary motor area, and their network connections in the frontal variant of AHS, and the inferior parietal lobule and connections in the posterior variant. Several theories are proposed to explain the pathophysiology. Herein, we review the literature to update advances in the understanding of the classification, pathophysiology, etiology, and treatment of AHS.

  16. A method to calculate and counterbalance the inertia force of slider-crank mechanisms in high-speed presses

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    A new method to calculate and counterbalance the inertia force of slider-crank mechanisms in high-speed mechanical presses was put forward. By analyzing the kinematic characteristics of a center-located slider-crank mechanism whose crank rotates at a constant angular velocity,the kinematic parameters of the slide,connecting rod and crank were formulated approximately. On the basis of the results above,three inertia forces and the input moment in the mechanism during its idle running were investigated and fo...

  17. Correlation between endoscopic sex determination and gonad histology in pond sliders, Trachemys scripta (Reptilia: Testudines: Emydidae

    Directory of Open Access Journals (Sweden)

    David Perpiñán

    2016-06-01

    Full Text Available Coelioscopy has been proven to be a valuable technique to determine the sex of juvenile chelonians. However, there is a disagreement regarding the proper way to identify testes and ovaries, which is a direct consequence of the lack of studies correlating the results of endoscopic examination with the histology of the gonad. In this blinded study we assessed two methods of sex determination in juvenile pond sliders (Trachemys scripta using endoscopy: via coelioscopy, with visualization of the gonads, and via cloacoscopy, with visualization of phallus/clitoris; we then compared the results of these procedures with the histology of the gonad. The results of gonad histology correlated 100% with the results from coelioscopic examination, but only 57.77% of the results obtained by cloacoscopy were accurate. Using cloacoscopy, 83.33% of males and 38.46% of females were misdiagnosed. Sex determination of juvenile pond sliders was considered accurate when coelioscopy was used, but inaccurate when cloacoscopy with identification of phallus/clitoris was attempted.

  18. AliEn Resource Brokers

    OpenAIRE

    Saiz, Pablo; Buncic, Predrag; Peters, Andreas J.

    2003-01-01

    AliEn (ALICE Environment) is a lightweight GRID framework developed by the Alice Collaboration. When the experiment starts running, it will collect data at a rate of approximately 2 PB per year, producing O(109) files per year. All these files, including all simulated events generated during the preparation phase of the experiment, must be accounted and reliably tracked in the GRID environment. The backbone of AliEn is a distributed file catalogue, which associates universal logical file name...

  19. Synergistic impacts by an invasive amphipod and an invasive fish explain native gammarid extinction

    OpenAIRE

    Beggel, S.; Brandner, J.; Cerwenka, A. F.; Geist, J.

    2016-01-01

    Background Worldwide freshwater ecosystems are increasingly affected by invasive alien species. In particular, Ponto-Caspian gobiid fishes and amphipods are suspected to have pronounced effects on aquatic food webs. However, there is a lack of systematic studies mechanistically testing the potential synergistic effects of invasive species on native fauna. In this study we investigated the interrelations between the invasive amphipod Dikerogammarus villosus and the invasive fish species Neogob...

  20. Alien and endangered plants in the Brazilian Cerrado exhibit contrasting relationships with vegetation biomass and N : P stoichiometry.

    Science.gov (United States)

    Lannes, Luciola S; Bustamante, Mercedes M C; Edwards, Peter J; Venterink, Harry Olde

    2012-11-01

    Although endangered and alien invasive plants are commonly assumed to persist under different environmental conditions, surprisingly few studies have investigated whether this is the case. We examined how endangered and alien species are distributed in relation to community biomass and N : P ratio in the above-ground community biomass in savanna vegetation in the Brazilian Cerrado. For 60 plots, we related the occurrence of endangered (Red List) and alien invasive species to plant species richness, vegetation biomass and N : P ratio, and soil variables. Endangered plants occurred mainly in plots with relatively low above-ground biomass and high N : P ratios, whereas alien invasive species occurred in plots with intermediate to high biomass and low N : P ratios. Occurrences of endangered or alien plants were unrelated to extractable N and P concentrations in the soil. These contrasting distributions in the Cerrado imply that alien species only pose a threat to endangered species if they are able to invade sites occupied by these species and increase the above-ground biomass and/or decrease the N : P ratio of the vegetation. We found some evidence that alien species do increase above-ground community biomass in the Cerrado, but their possible effect on N : P stoichiometry requires further study.

  1. Ancient aliens on mars

    CERN Document Server

    Bara, Mike

    2013-01-01

    Best-selling author and Secret Space Program researcher Bara brings us this lavishly illustrated volume on alien structures on Mars. Was there once a vast, technologically advanced civilization on Mars, and did it leave evidence of its existence behind for humans to find eons later? Did these advanced extraterrestrial visitors vanish in a solar system wide cataclysm of their own making, only to make their way to Earth and start anew? Was Mars once as lush and green as the Earth, and teeming with life? Did Mars once orbit a missing member of the solar system, a "Super Earth” that vanished in a disaster that devastated life on Earth and Venus and left us only the asteroid belt as evidence of its once grand existence? Did the survivors of this catastrophe leave monuments and temples behind, arranged in a mathematical precision designed to teach us the Secret of a new physics that could lift us back to the stars? Does the planet have an automated defense shield that swallows up robotic probes if they wander int...

  2. Comparing determinants of alien bird impacts across two continents: implications for risk assessment and management

    Science.gov (United States)

    Evans, Thomas; Kumschick, Sabrina; Dyer, Ellie; Blackburn, Tim

    2014-01-01

    Invasive alien species can have serious adverse impacts on both the environment and the economy. Being able to predict the impacts of an alien species could assist in preventing or reducing these impacts. This study aimed to establish whether there are any life history traits consistently correlated with the impacts of alien birds across two continents, Europe and Australia, as a first step toward identifying life history traits that may have the potential to be adopted as predictors of alien bird impacts. A recently established impact scoring system was used in combination with a literature review to allocate impact scores to alien bird species with self-sustaining populations in Australia. These scores were then tested for correlation with a series of life history traits. The results were compared to data from a previous study in Europe, undertaken using the same methodology, in order to establish whether there are any life history traits consistently correlated with impact across both continents. Habitat generalism was the only life history trait found to be consistently correlated with impact in both Europe and Australia. This trait shows promise as a potential predictor of alien bird impacts. The results support the findings of previous studies in this field, and could be used to inform decisions regarding the prevention and management of future invasions. PMID:25165531

  3. A method to calculate and counterbalance the inertia force of slider-crank mechanisms in high-speed presses

    Institute of Scientific and Technical Information of China (English)

    Jim Wang; Sheng-dun Zhao; Hu-shan Shi; Chun-jian Hua

    2009-01-01

    A new method to calculate and counterbalance the inertia force of slider-crank mechanisms in high-speed mechanical presses was put forward. By analyzing the kinematic characteristics of a center-located slider-crank mechanism whose crank rotates at a constant angular velocity, the kinematic parameters of the slide, connecting rod and crank were formulated approximately. On the basis of the results above, three inertia forces and the input moment in the mechanism during its idle running were investigated and formulated by dynamic analysis. A verification experiment was performed on a slider-crank mechanism at a high-speed press machine. The forces derived from the established formulas were compared respectively with those obtained by the ADAMS software and the classical method of connecting rod mass substitution. It was experimentally found that the proposed formulas have an improved performance over related earlier techniques. By use of these results, a 1000 kN 1250 rpm four-point high-speed press machine was designed and manufactured. The slide of this press is driven by four sets of slider-crank mechanisms with symmetrical layout and opposite rotation directions to counterbalance the horizontal inertia forces. Four eccentric counterbalance blocks were designed to counterbalance the vertical force after their mass and equivalent eccentric radius were formulated. The high-speed press machine designed by the proposed counterbalance method has worked with satisfactory performance and good dynamic balance for more than four years in practical production.

  4. Records of alien marine species in the shallow coastal waters of Chios Island (2009

    Directory of Open Access Journals (Sweden)

    S. KATSANEVAKIS

    2012-12-01

    Full Text Available The shallow coastline of Chios Island was surveyed for the presence of any alien marine benthic species, during August 2009. Fourteen randomly selected sites were surveyed by snorkeling during standardized one-hour transects at depths between 0 and 10 m, and the presence of all identified alien benthic species was recorded. Six alien species were identified: Asparagopsis taxiformis, Caulerpa racemosa var. cylindracea, Stypopodium schimperi, Halophila stipulacea, Percnon gibbesi, and Siganus luridus. The green alga C. racemosa var. cylindracea was found in high densities in all the surveyed sites and was characterized as invasive in the island. The brown alga S. schimperi, the crab P. gibbesi, and the fish S. luridussustain established populations in the area. For three of the recorded marine alien species (S. schimperi, P. gibbesi, and S. luridus,Chios Island seems to be the northernmost margin of their geographical range in the Aegean Sea.

  5. Geographical constraints are stronger than invasion patterns for European urban floras.

    Directory of Open Access Journals (Sweden)

    Carlo Ricotta

    Full Text Available Understanding the mechanisms that affect invasion success of alien species is an important prerequisite for the effective management of present and future aliens. To gain insight into this matter we asked the following questions: Are the geographical patterns of species distributions in urban floras different for native compared with alien plant species? Does the introduction of alien species contribute to the homogenization of urban floras? We used a Mantel test on Jaccard dissimilarity matrices of 30 urban floras across the British Isles, Italy and central Europe to compare the spatial distribution of native species with four classes of alien species: archaeophytes, all neophytes, non-invasive neophytes, and invasive neophytes. Archaeophytes and neophytes are species that were introduced into Europe before and after 1500 AD, respectively. To analyze the homogenizing effect of alien species on the native urban floras, we tested for differences in the average dissimilarity of individual cities from their group centroid in ordination space. Our results show that the compositional patterns of native and alien species seem to respond to the same environmental drivers, such that all four classes of alien species were significantly related to native species across urban floras. In this framework, alien species may have an impact on biogeographic patterns of urban floras in ways that reflect their history of introduction and expansion: archaeophytes and invasive neophytes tended to homogenize, while non-invasive neophytes tended to differentiate urban floras.

  6. Geographical Constraints Are Stronger than Invasion Patterns for European Urban Floras

    Science.gov (United States)

    Ricotta, Carlo; Celesti-Grapow, Laura; Kühn, Ingolf; Rapson, Gillian; Pyšek, Petr; La Sorte, Frank A.; Thompson, Ken

    2014-01-01

    Understanding the mechanisms that affect invasion success of alien species is an important prerequisite for the effective management of present and future aliens. To gain insight into this matter we asked the following questions: Are the geographical patterns of species distributions in urban floras different for native compared with alien plant species? Does the introduction of alien species contribute to the homogenization of urban floras? We used a Mantel test on Jaccard dissimilarity matrices of 30 urban floras across the British Isles, Italy and central Europe to compare the spatial distribution of native species with four classes of alien species: archaeophytes, all neophytes, non-invasive neophytes, and invasive neophytes. Archaeophytes and neophytes are species that were introduced into Europe before and after 1500 AD, respectively. To analyze the homogenizing effect of alien species on the native urban floras, we tested for differences in the average dissimilarity of individual cities from their group centroid in ordination space. Our results show that the compositional patterns of native and alien species seem to respond to the same environmental drivers, such that all four classes of alien species were significantly related to native species across urban floras. In this framework, alien species may have an impact on biogeographic patterns of urban floras in ways that reflect their history of introduction and expansion: archaeophytes and invasive neophytes tended to homogenize, while non-invasive neophytes tended to differentiate urban floras. PMID:24465640

  7. Efficient distinction of invasive aquatic plant species from non-invasive related species using DNA barcoding

    NARCIS (Netherlands)

    Ghahramanzadeh, R.; Esselink, G.; Kodde, L.P.; Duistermaat, H.; Valkenburg, van J.L.C.H.; Marashi, S.H.; Smulders, M.J.M.; Wiel, van de C.C.M.

    2013-01-01

    Biological invasions are regarded as threats to global biodiversity. Among invasive aliens, a number of plant species belonging to the genera Myriophyllum, Ludwigia and Cabomba, and to the Hydrocharitaceae family pose a particular ecological threat to water bodies. Therefore, one would try to preven

  8. Evaluation of online information sources on alien species in Europe: the need of harmonization and integration.

    Science.gov (United States)

    Gatto, Francesca; Katsanevakis, Stelios; Vandekerkhove, Jochen; Zenetos, Argyro; Cardoso, Ana Cristina

    2013-06-01

    Europe is severely affected by alien invasions, which impact biodiversity, ecosystem services, economy, and human health. A large number of national, regional, and global online databases provide information on the distribution, pathways of introduction, and impacts of alien species. The sufficiency and efficiency of the current online information systems to assist the European policy on alien species was investigated by a comparative analysis of occurrence data across 43 online databases. Large differences among databases were found which are partially explained by variations in their taxonomical, environmental, and geographical scopes but also by the variable efforts for continuous updates and by inconsistencies on the definition of "alien" or "invasive" species. No single database covered all European environments, countries, and taxonomic groups. In many European countries national databases do not exist, which greatly affects the quality of reported information. To be operational and useful to scientists, managers, and policy makers, online information systems need to be regularly updated through continuous monitoring on a country or regional level. We propose the creation of a network of online interoperable web services through which information in distributed resources can be accessed, aggregated and then used for reporting and further analysis at different geographical and political scales, as an efficient approach to increase the accessibility of information. Harmonization, standardization, conformity on international standards for nomenclature, and agreement on common definitions of alien and invasive species are among the necessary prerequisites.

  9. Evaluation of Online Information Sources on Alien Species in Europe: The Need of Harmonization and Integration

    Science.gov (United States)

    Gatto, Francesca; Katsanevakis, Stelios; Vandekerkhove, Jochen; Zenetos, Argyro; Cardoso, Ana Cristina

    2013-06-01

    Europe is severely affected by alien invasions, which impact biodiversity, ecosystem services, economy, and human health. A large number of national, regional, and global online databases provide information on the distribution, pathways of introduction, and impacts of alien species. The sufficiency and efficiency of the current online information systems to assist the European policy on alien species was investigated by a comparative analysis of occurrence data across 43 online databases. Large differences among databases were found which are partially explained by variations in their taxonomical, environmental, and geographical scopes but also by the variable efforts for continuous updates and by inconsistencies on the definition of "alien" or "invasive" species. No single database covered all European environments, countries, and taxonomic groups. In many European countries national databases do not exist, which greatly affects the quality of reported information. To be operational and useful to scientists, managers, and policy makers, online information systems need to be regularly updated through continuous monitoring on a country or regional level. We propose the creation of a network of online interoperable web services through which information in distributed resources can be accessed, aggregated and then used for reporting and further analysis at different geographical and political scales, as an efficient approach to increase the accessibility of information. Harmonization, standardization, conformity on international standards for nomenclature, and agreement on common definitions of alien and invasive species are among the necessary prerequisites.

  10. Reliability analysis of kinematic accuracy for the elastic slider-crank mechanism

    Institute of Scientific and Technical Information of China (English)

    TUO Yaofei; CHEN Jianjun; ZHANG Chijiang; CHEN Yongqin

    2007-01-01

    This paper deals with the static and dynamic output kinematic accuracy of a group of elastic slider-crank mechanisms with the same design parameters by taking the bar length,the joint-gaps,the mass density,and the sectional and the physical parameters as random variables.According to the principle of linear pile-up of small displacement,the static and dynamic output kinematic errors are synthesized,and the reliability model of the kinematic accuracy of the mechanism is built.Through an example,a study of the influencing factors on the reliability of the output kinematic accuracy of the mechanism is made.The results obtained reveal the following facts:with the increase of the crank's rotating speed,the dynamic elastic deformation of the mechanism becomes the principal factor that greatly affects the reliability of the output kinematic accuracy of the mechanism.

  11. Irregular Wave Energy Extraction Analysis for a Slider Crank WEC Power Take-Off System

    Energy Technology Data Exchange (ETDEWEB)

    Sang, Yuanrui; Karayaka, H. Bora; Yan, Yanjun; Zhang, James Z.; Muljadi, Eduard

    2015-09-02

    Slider crank Wave Energy Converter (WEC) is a novel energy conversion device. It converts wave energy into electricity at a relatively high efficiency, and it features a simple structure. Past analysis on this WEC has been done under regular sinusoidal wave conditions, and a suboptimal energy could be achieved. This paper presents the analysis of the system under irregular wave conditions; a time-domain hydrodynamics model is adopted and the control methodology is modified to better serve the irregular wave conditions. Results from the simulations show that the performance of the system under irregular wave conditions is different from that under regular sinusoidal wave conditions, but still a reasonable amount of energy can be extracted.

  12. Energy Extraction from a Slider-Crank Wave Energy under Irregular Wave Conditions: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Sang, Yuanrui; Karayaka, H. Bora; Yan, Yanjun; Zhang, James Z.; Muljadi, Eduard; Yu, Yi-Hsiang

    2015-08-24

    A slider-crank wave energy converter (WEC) is a novel energy conversion device. It converts wave energy into electricity at a relatively high efficiency, and it features a simple structure. Past analysis on this particular WEC has been done under regular sinusoidal wave conditions, and suboptimal energy could be achieved. This paper presents the analysis of the system under irregular wave conditions; a time-domain hydrodynamics model is adopted and a rule-based control methodology is introduced to better serve the irregular wave conditions. Results from the simulations show that the performance of the system under irregular wave conditions is different from that under regular sinusoidal wave conditions, but a reasonable amount of energy can still be extracted.

  13. The Affective Slider: A Digital Self-Assessment Scale for the Measurement of Human Emotions.

    Directory of Open Access Journals (Sweden)

    Alberto Betella

    Full Text Available Self-assessment methods are broadly employed in emotion research for the collection of subjective affective ratings. The Self-Assessment Manikin (SAM, a pictorial scale developed in the eighties for the measurement of pleasure, arousal, and dominance, is still among the most popular self-reporting tools, despite having been conceived upon design principles which are today obsolete. By leveraging on state-of-the-art user interfaces and metacommunicative pictorial representations, we developed the Affective Slider (AS, a digital self-reporting tool composed of two slider controls for the quick assessment of pleasure and arousal. To empirically validate the AS, we conducted a systematic comparison between AS and SAM in a task involving the emotional assessment of a series of images taken from the International Affective Picture System (IAPS, a database composed of pictures representing a wide range of semantic categories often used as a benchmark in psychological studies. Our results show that the AS is equivalent to SAM in the self-assessment of pleasure and arousal, with two added advantages: the AS does not require written instructions and it can be easily reproduced in latest-generation digital devices, including smartphones and tablets. Moreover, we compared new and normative IAPS ratings and found a general drop in reported arousal of pictorial stimuli. Not only do our results demonstrate that legacy scales for the self-report of affect can be replaced with new measurement tools developed in accordance to modern design principles, but also that standardized sets of stimuli which are widely adopted in research on human emotion are not as effective as they were in the past due to a general desensitization towards highly arousing content.

  14. 8 CFR 1214.2 - Review of alien victims of severe forms of trafficking in persons; aliens in pending immigration...

    Science.gov (United States)

    2010-01-01

    ... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Review of alien victims of severe forms of trafficking in persons; aliens in pending immigration proceedings. 1214.2 Section 1214.2 Aliens and... NONIMMIGRANT CLASSES § 1214.2 Review of alien victims of severe forms of trafficking in persons; aliens...

  15. Update of marine alien species in Hellenic waters

    Directory of Open Access Journals (Sweden)

    M.A. PANCUCCI-PAPADOPOULOU

    2012-12-01

    Full Text Available The list of marine alien species in Hellenic waters is updated taking into account new findings (published and unpublished data. According to the present work, the number of these species has increased from 90 (known until end 2003 to 128. Most of them are zoobenthic species followed by fish and macroalgae. An interannual analysis revealed an important increase of alien species during the last years. The study of their geographic distribution showed that their majority is present in the southeastern Aegean. More than 55% of them are well established, while about 40% are casual records. Their main pathway of introduction seems to be the Suez Canal followed by shipping, whereas the Straits of Gibraltar, aquaculture and the Straits of Dardanelles appear to play a less important role in their invasion of Hellenic waters. These findings are discussed considering environmental and anthropogenic factors.

  16. How Do Alien Plants Fit in the Space-Phylogeny Matrix?

    Science.gov (United States)

    Procheş, Şerban; Forest, Félix; Jose, Sarah; De Dominicis, Michela; Ramdhani, Syd; Wiggill, Timothy

    2015-01-01

    Recent advances in the field of plant community phylogenetics and invasion phylogenetics are mostly based on plot-level data, which do not take into consideration the spatial arrangement of individual plants within the plot. Here we use within-plot plant coordinates to investigate the link between the physical distance separating plants, and their phylogenetic relatedness. We look at two vegetation types (forest and grassland, similar in species richness and in the proportion of alien invasive plants) in subtropical coastal KwaZulu-Natal, South Africa. The relationship between phylogenetic distance and physical distance is weak in grassland (characterised by higher plant densities and low phylogenetic diversity), and varies substantially in forest vegetation (variable plant density, higher phylogenetic diversity). There is no significant relationship between the proportion of alien plants in the plots and the strength of the physical-phylogenetic distance relationship, suggesting that alien plants are well integrated in the local spatial-phylogenetic landscape. PMID:25893962

  17. Functional differences between native and alien species: a global-scale comparison

    DEFF Research Database (Denmark)

    Ordonez Gloria, Alejandro

    2010-01-01

    1. A prevalent question in the study of plant invasions has been whether or not invasions can be explained on the basis of traits. Despite many attempts, a synthetic view of multi-trait differences between alien and native species is not yet available.2. We compiled a database of three ecologically...... important traits (specific leaf area, typical maximum canopy height, individual seed mass) for 4473 species sampled over 95 communities (3784 species measured in their native range, 689 species in their introduced range, 207 in both ranges).3. Considering each trait separately, co-occurring native and alien...... species significantly differed in their traits. These differences, although modest, were expressed in a combined 15% higher specific leaf area, 16% lower canopy height and 26% smaller seeds.4. Using three novel multi-trait metrics of functional diversity, aliens showed significantly smaller trait ranges...

  18. 33 CFR 125.25 - Aliens.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Aliens. 125.25 Section 125.25 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) WATERFRONT....25 Aliens. Alien registration records together with other papers and documents which indicated...

  19. 22 CFR 62.27 - Alien physicians.

    Science.gov (United States)

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Alien physicians. 62.27 Section 62.27 Foreign... Provisions § 62.27 Alien physicians. (a) Purpose. Pursuant to the Mutual Educational and Cultural Exchange... Foreign Medical Graduates must sponsor alien physicians who wish to pursue programs of graduate...

  20. Expanding the Parameters of Parental Alienation Syndrome.

    Science.gov (United States)

    Cartwright, Glenn F.

    1993-01-01

    Because parental alienation syndrome is newly recognized, it must be redefined as new cases are observed. Evidence suggests that alienation may be provoked by other than custodial matters, cases of alleged sexual abuse may be hinted, slow judgments by courts exacerbate problem, prolonged alienation of child may trigger mental illness, and little…

  1. Invasive ornamental fish: a potential threat to aquatic biodiversity in peninsular India

    Directory of Open Access Journals (Sweden)

    J.D.M. Knight

    2010-02-01

    Full Text Available Alien fish find their way into newer habitats and ecosystems opportunistically. Once in a new habitat, these species try to occupy empty niches and compete with native species. An alien species becomes invasive wherever it has a competetive advantage over native species. Ecology of aquatic invasive alien species is rather poorly understood as most attention has been on invertebrates as that which spread through ballast water. Invasive alien species of fish that have taken advantage of the aquarium trade are emerging as the most important threats to fragile aquatic habitats. Regulations to this trade are rather weak and there is a general lack of data on the ecological impact of alien fish species despite the fact that a third of the world’s worst aquatic invasive species are aquarium or ornamental species.

  2. 湿地外来植物香菇草(Hydrocotyle vulgaris)入侵风险研究%Study on invasion risk of Hydrocotyle vulgaris as an alien species in wetlands

    Institute of Scientific and Technical Information of China (English)

    缪丽华; 季梦成; 王莹莹; 乔东东; 陈煜初

    2011-01-01

    通过对香菇草(Hydrocotyle vulgaris)形态特征、生长习性以及繁殖特点的研究以揭示其入侵风险.结果表明:1)香菇草适应性强,具有表型可塑性,能适应水生到旱生、强光到隐蔽等多种生境,并具有较好的耐受性,从而能占据更宽的生态幅;2)侵占力强,能形成比较高密度的植株丛成片生长,地下部分由根茎和大量的不定根密集网状交错,在地上、地下高密度占领生境从而排挤其他植物,降低群落物种多样性;3)繁殖速度快,可营养繁殖和种子繁殖,以根茎营养繁殖为主,自然生长的香菇草个体1年繁殖倍数达到50倍以上;4)根除难度大,根茎的片断残留仍然可生长成新的植株再次快速繁殖扩大;5)根据香菇草的生长习性,其适生区域的气候特征指标为:日平均温度稳定≥10℃天数多于180 d,最冷月(1月)平均温度高于-5℃,年极端最低气温不低于-10℃;结合我国的气候数据,预测划分香菇草的适生范围包括:中国北亚热带湿润区、中亚热带湿润区、南亚热带湿润区、边缘热带湿润区、中热带湿润区、赤道热带湿润区和中国高原亚热带地区;6)采用外来物种入侵风险指数评估体系分析香菇草的入侵风险表明,其入侵风险指数可确定得分为71分,其中“繁殖和扩散特性”项目得39分.说明香菇草入侵风险程度极高,属于“不可引入物种”.最后提出了香菇草入侵风险管理建议.%The growth habit, morphological and reproductive characteristics of Hydrocotyle vulgaris were systematically described to assess its invasion risks. The results showed that the invasion risks of H. Vulgaris were displayed in four aspects. First, the adaptability and phenotypic plasticity of H. Vulgaris ensured its adaptation to the environment. Also its tolerance contributed to the occupation of wider ecological amplitude. Second, the aggressive ability made it able to occupy the habitat

  3. A List of Alien Plants in the Kruger National Park

    Directory of Open Access Journals (Sweden)

    I.A.W. Macdonald

    1988-10-01

    Full Text Available The alien vascular plant flora of the Kruger National Park is listed. Annotations cover the invasive status, modes of introduction and dispersal, dates of first recording, ecological impacts and control status of each species. The list comprises 156 species of which 113 are considered invasive within the park. Most of the species have been accidentally introduced to the park. The ecological impacts of 27 species (of which 11 are trees and shrubs were rated as moderate or high. By 1985 only 10 species are thought to have been eradicated from the park. Most of the invasive species are herbaceous weeds of man-disturbed sites and the eradication of these is generally considered impossible. Most of the important species are dispersed by water and animals. The significance of limiting reinvasion of the park down the rivers flowing into the park, is stressed.

  4. Which Factors Affect the Success or Failure of Eradication Campaigns against Alien Species?

    NARCIS (Netherlands)

    Pluess, T.; Jarošík, V.; Pysek, P.; Cannon, R.; Pergl, J.; Breukers, A.; Bacher, S.

    2012-01-01

    Although issues related to the management of invasive alien species are receiving increasing attention, little is known about which factors affect the likelihood of success of management measures. We applied two data mining techniques, classification trees and boosted trees, to identify factors that

  5. Optimal Resource Management in the Presence of a Deleterious Alien Species

    NARCIS (Netherlands)

    Batabyal, A.A.; Nijkamp, Peter

    2007-01-01

    Various plants and resources such as orchards are vulnerable to the detrimental effects of successful invasions by alien animal or plant species. To outline an appropriate policy response, we first use renewal theory to construct a stochastic model of optimal orchard management in the presence of a

  6. Germination Response of Four Alien Congeneric Amaranthus Species to Environmental Factors

    Science.gov (United States)

    Hao, Jian-Hua; Lv, Shuang-Shuang; Bhattacharya, Saurav; Fu, Jian-Guo

    2017-01-01

    Seed germination is the key step for successful establishment, growth and further expansion of population especially for alien plants with annual life cycle. Traits like better adaptability and germination response were thought to be associated with plant invasion. However, there are not enough empirical studies correlating adaptation to environmental factors with germination response of alien invasive plants. In this study, we conducted congeneric comparisons of germination response to different environmental factors such as light, pH, NaCl, osmotic and soil burials among four alien amaranths that differ in invasiveness and have sympatric distribution in Jiangsu Province, China. The data were used to create three-parameter sigmoid and exponential decay models, which were fitted to cumulative germination and emergence curves. The results showed higher maximum Germination (Gmax), shorter time for 50% germination (G50) and the rapid slope (Grate) for Amaranthus blitum (low-invasive) and A. retroflexus (high-invasive) compare to intermediately invasive A. spinosus and A. viridis in all experimental regimes. It indicated that germination potential does not necessarily constitute a trait that can efficiently distinguish highly invasive and low invasive congeners in four Amaranthus species. However, it was showed that the germination performances of four amaranth species were more or less correlated with their worldwide distribution area. Therefore, the germination performance can be used as a reference indicator, but not an absolute trait for invasiveness. Our results also confirmed that superior germination performance in wide environmental conditions supplementing high seed productivity in highly invasive A. retroflexus might be one of the reasons for its prolific growth and wide distribution. These findings lay the foundation to develop more efficient weed management practice like deep burial of seeds by turning over soil and use of tillage agriculture to control

  7. Germination Response of Four Alien Congeneric Amaranthus Species to Environmental Factors.

    Science.gov (United States)

    Hao, Jian-Hua; Lv, Shuang-Shuang; Bhattacharya, Saurav; Fu, Jian-Guo

    2017-01-01

    Seed germination is the key step for successful establishment, growth and further expansion of population especially for alien plants with annual life cycle. Traits like better adaptability and germination response were thought to be associated with plant invasion. However, there are not enough empirical studies correlating adaptation to environmental factors with germination response of alien invasive plants. In this study, we conducted congeneric comparisons of germination response to different environmental factors such as light, pH, NaCl, osmotic and soil burials among four alien amaranths that differ in invasiveness and have sympatric distribution in Jiangsu Province, China. The data were used to create three-parameter sigmoid and exponential decay models, which were fitted to cumulative germination and emergence curves. The results showed higher maximum Germination (Gmax), shorter time for 50% germination (G50) and the rapid slope (Grate) for Amaranthus blitum (low-invasive) and A. retroflexus (high-invasive) compare to intermediately invasive A. spinosus and A. viridis in all experimental regimes. It indicated that germination potential does not necessarily constitute a trait that can efficiently distinguish highly invasive and low invasive congeners in four Amaranthus species. However, it was showed that the germination performances of four amaranth species were more or less correlated with their worldwide distribution area. Therefore, the germination performance can be used as a reference indicator, but not an absolute trait for invasiveness. Our results also confirmed that superior germination performance in wide environmental conditions supplementing high seed productivity in highly invasive A. retroflexus might be one of the reasons for its prolific growth and wide distribution. These findings lay the foundation to develop more efficient weed management practice like deep burial of seeds by turning over soil and use of tillage agriculture to control

  8. The Mexican "Illegal Alien" Commute.

    Science.gov (United States)

    Decker, Phil

    1986-01-01

    A photo report of the following three treks by illegal aliens across the border from Mexico to work in Arizona reveals the dangers and disappointments the migrants are exposed to: (1) a "carpool" from Southern Mexico; (2) a train ride from Sinaloa; and (3) a 40-mile hike through the Arizona desert. (PS)

  9. Can we Communicate with Aliens?

    Science.gov (United States)

    Csányi, V.; Kampis, Gy.

    The subject of this paper is: what answer can be given if the aliens are neither animals nor humans of an unknown culture, but specimens of an extraterrestrial intelligence? If we generalize this question, we may ask, how and to what extent is communication possible among intelligent beings?

  10. Invasive mutualists erode native pollination webs.

    Directory of Open Access Journals (Sweden)

    Marcelo A Aizen

    2008-02-01

    Full Text Available Plant-animal mutualisms are characterized by weak or asymmetric mutual dependences between interacting species, a feature that could increase community stability. If invasive species integrate into mutualistic webs, they may alter web structure, with consequences for species persistence. However, the effect of alien mutualists on the architecture of plant-pollinator webs remains largely unexplored. We analyzed the extent of mutual dependency between interacting species, as a measure of mutualism strength, and the connectivity of 10 paired plant-pollinator webs, eight from forests of the southern Andes and two from oceanic islands, with different incidences of alien species. Highly invaded webs exhibited weaker mutualism than less-invaded webs. This potential increase in network stability was the result of a disproportionate increase in the importance and participation of alien species in the most asymmetric interactions. The integration of alien mutualists did not alter overall network connectivity, but links were transferred from generalist native species to super-generalist alien species during invasion. Therefore, connectivity among native species declined in highly invaded webs. These modifications in the structure of pollination webs, due to dominance of alien mutualists, can leave many native species subject to novel ecological and evolutionary dynamics.

  11. Searching for Alien Life Having Unearthly Biochemistry

    Science.gov (United States)

    Jones, Harry

    2003-01-01

    The search for alien life in the solar system should include exploring unearth-like environments for life having an unearthly biochemistry. We expect alien life to conform to the same basic chemical and ecological constraints as terrestrial life, since inorganic chemistry and the laws of ecosystems appear to be universal. Astrobiologists usually assume alien life will use familiar terrestrial biochemistry and therefore hope to find alien life by searching near water or by supplying hydrocarbons. The assumption that alien life is likely to be based on carbon and water is traditional and plausible. It justifies high priority for missions to search for alien life on Mars and Europa, but it unduly restricts the search for alien life. Terrestrial carbon-water biochemistry is not possible on most of the bodies of our solar system, but all alien life is not necessarily based on terrestrial biochemistry. If alien life has a separate origin from Earth life, and if can survive in an environment extremely different from Earth's, then alien life may have unearthly biochemistry. There may be other solvents than water that support alien life and other elements than carbon that form complex life enabling chain molecules. Rather than making the exploration-restricting assumption that all life requires carbon, water, and terrestrial biochemistry, we should make the exploration-friendly assumption that indigenous, environmentally adapted, alien life forms might flourish using unearthly biochemistry in many places in the solar system. Alien life might be found wherever there is free energy and a physical/chemical system capable of using that energy to build living structures. Alien life may be discovered by the detection of some general non-equilibrium chemistry rather than of terrestrial biochemistry. We should explore all the potential abodes of life in the solar system, including those where life based on terrestrial biochemistry can not exist.

  12. Modified technique of using conventional slider boat for liquid phase epitaxy of silicon for solar cell application

    Indian Academy of Sciences (India)

    D Majumdar; S Chatterjee; U Gangopadhyay; H Saha

    2003-10-01

    Epitaxial layers of silicon are grown on single crystal Si-substrate from a solution of silicon in indium using conventional graphite slider boat technique. The important problems of natural convection due to lower density of silicon compared to indium, poor wetting of substrate due to high angle of contact of indium solution on silicon substrate resulting in poor nucleation, melt removal from the growth substrate and saturation wafer associated with LPE in this technique are practically eliminated using sandwich method with simple modifications of the boat and the method of growth. Some experimental studies on the effect of different surface preparations of growth substrate are also reported. Growth results are shown and discussed. Further, improvization of slider boat to facilitate better study of growth parameters is suggested in the line of modification already carried out.

  13. Correlation between endoscopic sex determination and gonad histology in pond sliders, Trachemys scripta (Reptilia: Testudines: Emydidae)

    OpenAIRE

    2016-01-01

    Coelioscopy has been proven to be a valuable technique to determine the sex of juvenile chelonians. However, there is a disagreement regarding the proper way to identify testes and ovaries, which is a direct consequence of the lack of studies correlating the results of endoscopic examination with the histology of the gonad. In this blinded study we assessed two methods of sex determination in juvenile pond sliders (Trachemys scripta) using endoscopy: via coelioscopy, with visualization of the...

  14. Roles of diet protein and temperature in the growth and nutritional energetics of juvenile slider turtles, Trachemys scripta

    Science.gov (United States)

    Avery, Harold W.; Spotila, James R.; Congdon, Justin D.; Fischer, Robert U.; Standora, Edward A.; Avery, Susan B.

    1993-01-01

    We determined the effects of dietary protein and Ta on growth rates, food consumption rates, digestion rates, and digestive efficiencies of juvenile slider turtles (Trachemys scripta). Results from this study provide a clearer understanding of how these environmental factors interact in influencing body sizes and growth rates of individuals in wild slider turtle populations. Changes in plastron length, carapace length, and body mass were significantly greater for T. scripta eating 25% and 40% crude protein diets than for those eating 10% crude protein. Those consuming 10% crude protein showed significant decreases in body mass and plastron length over a 13-wk period. Individuals at Ta's of 15°, 22°, 28°, or 34° C had food ingestion rates (kJ wk⁻¹) that increased markedly with an increase in Ta. Increasing dietary crude protein concentration increased turtle ingestion rates and influenced the positive effect of Ta. Increasing dietary crude protein concentration alone did not significantly affect turtle consumption rates but did significantly influence the positive effect of Ta. Digestive efficiencies were very high (because of the pelleted diet). Those turtles that ate at 15° C had a digestive efciency of 99.5%, as compared with 98.3% at 22° C, 94.8% at 28° C, and 95.8% at 34° C. Dietary protein concentration did not influence the digestive efficiencies of T. scripta. These data suggest that dietary protein is an important nutritional component to the growth of juvenile slider turtles and that elevated thermal conditions, combined with a high dietary protein availability, may explain the very high growth rates of slider turtles in some wild populations.

  15. Invasive mechanism and control strategy of Ageratina adenophora (Sprengel)

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    In order to ascertain the invasive mechanism and control strategy of the invasive Crofton weed, Ageratina adenophora, its ecological adaptability and population differentiation,the formation of single dominant population, displacement of native plants and sustainable management strategies were investigated. The present results helped to clarify and explain such issues as the adaptability post invasion,interaction and competition between inter-and intra-species and community resistance, thereby providing important references to researches on other invasive alien species.

  16. DEPENDENCE OF THE SLIDER DEFORMATION AND MACHINING PRECISION ON THE MULTIPURPOSE MACHINE-TOOL COMPLEX OF VM SERIES

    Directory of Open Access Journals (Sweden)

    Berezhnoy S. B.

    2016-04-01

    Full Text Available The article is devoted to the development of high-tech metal-working industry, as well as to the use of unmanned technology. We recommended measures to improve the accuracy and quality of manufacturing of complex and large workpieces weighing up to 100 tons. To date, the technical level of many economy sectors is largely determined by the level of the production means. Based on the engineering development there is an overall automation and mechanization of production and industry processes, construction, agriculture, transport and other industries. We analyzed forms of slide sections, of errors affecting the accuracy of the workpieces manufacturing. We made simulation of the cutting forces and sliders deformations. Solved measures increase manufacturing accuracy based on multi-purpose machine tool systems of VM series. We held the analysis of the dependence of cutting forces, a slider form on its strain in different types of processing. We obtained a graph of cutting force and precision manufacturing. We defined the optimal shape of the slider cross section to increase the rigidity and reduce the slide deformation in metal cutting

  17. Response of the JAK-STAT signaling pathway to oxygen deprivation in the red eared slider turtle, Trachemys scripta elegans.

    Science.gov (United States)

    Bansal, Saumya; Biggar, Kyle K; Krivoruchko, Anastasia; Storey, Kenneth B

    2016-11-15

    The red-eared slider turtle, Trachemys scripta elegans, is a model organism commonly used to study the environmental stress of anoxia. It exhibits multiple biochemical adaptations to ensure its survival during the winter months where quantities of oxygen are largely depleted. We proposed that JAK-STAT signaling would display stress responsive regulation to mediate the survival of the red-eared slider turtle, Trachemys scripta elegans, during anoxic stress. Importantly, the JAK-STAT signaling pathway is involved in transmitting extracellular signals to the nucleus resulting in the expression of select genes that aid cell survival and growth. Immunoblotting was used to compare the relative phosphorylation levels of JAK proteins, STAT proteins, and two of its inhibitors, SOCS and PIAS, in response to anoxia. A clear activation of the JAK-STAT pathway was observed in the liver tissue while no significant changes were found in the skeletal muscle. To further support our findings we also found an increase in mRNA transcripts of downstream targets of STATs, namely bcl-xL and bcl-2, using PCR analysis in the liver tissues. These findings suggest an important role for the JAK-STAT pathway in exhibiting natural anoxia tolerance by the red-eared slider turtle.

  18. Assessing the importance of alien macro-Crustacea (Malacostraca) within macroinvertebrate assemblages in Belgian coastal harbours

    Science.gov (United States)

    Boets, Pieter; Lock, Koen; Goethals, Peter L. M.

    2012-06-01

    Harbours, which are often characterised by anthropogenic stress in combination with intensive international ship traffic, tend to be very susceptible to aquatic invasions. Since alien macrocrustaceans are known to be very successful across many European waters, a study was made on their distribution and impact in the four Belgian coastal harbours (Nieuwpoort, Ostend, Blankenberge and Zeebrugge). Biological and physical-chemical data were gathered at 43 sampling sites distributed along a salinity gradient in the four harbours. One-fourth of all crustacean species recorded were alien and represented on average 30% of the total macrocrustacean abundance and 65% of the total macrocrustacean biomass. The large share of alien crustaceans in the total macrocrustacean biomass was mainly due to several large alien crab species. Most alien species were found in the oligohaline zone, whereas the number of indigenous species slightly increased with increasing salinity. The low number of indigenous species present at low salinities was probably not only caused by salinity, but also by the lower water quality in this salinity range. Based on the site-specific biocontamination index (SBCI), which was used to assess the ecological water quality, the harbour of Nieuwpoort and Ostend scored best and were classified as good, indicating the limited abundance and the low number of alien macrocrustaceans. Sampling locations situated more inland generally had a higher SBCI and a lower ecological water quality. Zeebrugge and Blankenberge were characterised by a severe biocontamination. For Zeebrugge, this is probably related to the intensive transcontinental commercial ship traffic, whereas for Blankenberge, this could be due to introduction of alien species via recreational crafts or due to its geographical location in the proximity of Zeebrugge. Consistent monitoring of estuarine regions and harbours, which are seen as hotspots for introductions, could help in understanding and

  19. 22 CFR 42.22 - Returning resident aliens.

    Science.gov (United States)

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Returning resident aliens. 42.22 Section 42.22... Returning resident aliens. (a) Requirements for returning resident status. An alien shall be classifiable as... presented that: (1) The alien had the status of an alien lawfully admitted for permanent residence at...

  20. 8 CFR 236.2 - Confined aliens, incompetents, and minors.

    Science.gov (United States)

    2010-01-01

    ... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Confined aliens, incompetents, and minors. 236.2 Section 236.2 Aliens and Nationality DEPARTMENT OF HOMELAND SECURITY IMMIGRATION REGULATIONS APPREHENSION AND DETENTION OF INADMISSIBLE AND DEPORTABLE ALIENS; REMOVAL OF ALIENS ORDERED REMOVED...

  1. 8 CFR 1241.30 - Aliens ordered deported.

    Science.gov (United States)

    2010-01-01

    ... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Aliens ordered deported. 1241.30 Section 1241.30 Aliens and Nationality EXECUTIVE OFFICE FOR IMMIGRATION REVIEW, DEPARTMENT OF JUSTICE IMMIGRATION REGULATIONS APPREHENSION AND DETENTION OF ALIENS ORDERED REMOVED Deportation of Aliens in...

  2. Interaction between two sliders in a system with rate- and state-dependent friction

    Institute of Scientific and Technical Information of China (English)

    HE; Changrong; (何昌荣)

    2003-01-01

    This study examines slip recurrence patterns in a two-block spring-slider model with rate- and state-dependent friction. Both weak and strong heterogeneities are considered with different settings of coupling stiffness. The results show that the recurrence pattern of slips strongly depends on the degree of coupling between the two blocks. With strong coupling between the two blocks (e.g., kc/ki max >~1), the slip pattern of the system is simple and characterized by periodical stick-slips, with the two blocks slipping together. With strong heterogeneity in friction strength, period-2 motion is found for moderate coupling stiffness (kc/ki max=0.4) between the two blocks. More complicated patterns are found with weak coupling stiffness (kc/ki max=0.2) and strong heterogeneity. With strong heterogeneity, very weak coupling leads to chaotic slip patterns. With coupling stiffness kc=5 ki max and strong heterogeneity, chaotic slip patterns are not found, in contrast with the results by Huang and Turcotte who employed the classical static/kinetic friction law.

  3. THE DEFORMATION EFFECT OF VM SLIDER MULTI COMPLEX MACHINE SERIES ON PRECISION MACHINING

    Directory of Open Access Journals (Sweden)

    Berezhnoy S. B.

    2015-09-01

    Full Text Available The article is devoted to the problems of increasing the economic growth of the Russian Federation, the development of high-tech knowledge-intensive manufacturing industries on the basis of a fundamentally new technological order, new unmanned technologies. The measures to improve the accuracy of manufacturing of complex and large-sized parts. Currently, the technical level of many sectors of the economy is largely determined by the level of production of means of production. The basis of these means is the machine tool industry. On the basis of machine tool development we handle a comprehensive mechanization and automation of production processes in industry, construction, agriculture, transport and other industries. We completed a comprehensive analysis of the errors affecting the manufacturing precision parts. The activities for improving the accuracy of manufacture based on VM 32 multi-machine complex series were proposed. We made the analysis of the cutting forces influence and the cross-sectional shape of the slide on its deformation for various types of processing. We determined the optimal shape of the cross section of the slider to increase stiffness and reduce deformation of the slide in metal cutting

  4. Influence of wall slip on the hydrodynamic behavior of a two-dimensional slider bearing

    Institute of Scientific and Technical Information of China (English)

    G.J.Ma; C.W.Wu; P.Zhou

    2007-01-01

    In the present paper, a multi-linearity method is used to address the nonlinear slip control equation for the hydrodynamic analysis of a two-dimensional (2-D) slip gap flow. Numerical analysis of a finite length slider beating with wall slip shows that the surface limiting shear stress exerts complicated influences on the hydrodynamic behavior of the gap flow. If the slip occurs at either the stationary surface or the moving surface (especially at the stationary surface),there is a transition point in the initial limiting shear stress for the proportional coefficient to affect the hydrodynamic load support in two opposite ways: it increases the hydrody-namic load support at higher initial limiting shear stresses, but decreases the hydrodynamic load support at lower ini-tial limiting shear stresses. If the slip occurs at the moving surface only, no fluid pressure is generated in the case of null initial limiting shear stress. If the slip occurs at both the surfaces with the same slip property, the hydrodynamic load support goes off after a critical sliding speed is reached. A small initial limiting shear stress and a small proportionality coefficient always give rise to a low friction drag.

  5. AliEn Resource Brokers

    CERN Document Server

    Saiz, P; Peters, A J; Saiz, Pablo; Buncic, Predrag; Peters, Andreas J.

    2003-01-01

    AliEn (ALICE Environment) is a lightweight GRID framework developed by the Alice Collaboration. When the experiment starts running, it will collect data at a rate of approximately 2 PB per year, producing O(109) files per year. All these files, including all simulated events generated during the preparation phase of the experiment, must be accounted and reliably tracked in the GRID environment. The backbone of AliEn is a distributed file catalogue, which associates universal logical file name to physical file names for each dataset and provides transparent access to datasets independently of physical location. The file replication and transport is carried out under the control of the File Transport Broker. In addition, the file catalogue maintains information about every job running in the system. The jobs are distributed by the Job Resource Broker that is implemented using a simplified pull (as opposed to traditional push) architecture. This paper describes the Job and File Transport Resource Brokers and sho...

  6. Alien liquid detector and control

    Energy Technology Data Exchange (ETDEWEB)

    Potter, B.M.

    1980-09-02

    An alien liquid detector employs a monitoring element and an energizing circuit for maintaining the temperature of the monitoring element substantially above ambient temperature. For this purpose an electronic circit controls a flow of heating current to the monitoring element. The presence of an alien liquid is detected by sensing a predetermined change in heating current flow to the monitoring element, e.g., to distinguish between water and oil. In preferred embodiments the monitoring element is a thermistor whose resistance is compared with a reference resistance and heating current through the thermistor is controlled in accordance with the difference. In one embodiment a bridge circuit senses the resistance difference; the difference may be sensed by an operational amplifier arrangement. Features of the invention include positioning the monitoring element at the surface of water, slightly immersed, so that the power required to maintain the thermistor temperature substantially above ambient temperature serves to detect presence of oil pollution at the surface.

  7. 'Would you eat an alien?'

    Science.gov (United States)

    2016-12-10

    A novel way of exploring comparative cognition, animal welfare ethics and human-animal relations formed the basis of this year's Wooldridge Memorial Lecture, held during the BVA Congress at the London Vet Show last month. Christine Nicol, of the University of Bristol, shared her experiences of making the BBC Radio 4 series 'Would you eat an alien?' and gave an insight into the ethical dilemmas that formed the basis of the programme. Laura Honey reports.

  8. Global networks for invasion science: benefits, challenges and guidelines

    DEFF Research Database (Denmark)

    Packer, Jasmin G.; Meyerson, Laura A.; Richardson, David M.;

    2016-01-01

    Much has been done to address the challenges of biological invasions, but fundamental questions (e.g., which species invade? Which habitats are invaded? How can invasions be effectively managed?) still need to be answered before the spread and impact of alien taxa can be effectively managed. Ques...

  9. A conceptual framework for invasion in microbial communities

    DEFF Research Database (Denmark)

    Kinnunen, Marta; Dechesne, Arnaud; Proctor, Caitlin

    2016-01-01

    and consistent terminology nor always include rigorous interpretations of the processes behind invasion. Therefore, we suggest that a consistent set of definitions and a rigorous conceptual framework are needed. We define invasion in a microbial community as the establishment of an alien microbial type...

  10. Economic essays on marine invasive species and international fisheries agreements

    NARCIS (Netherlands)

    Walker, A.N.

    2016-01-01

    This thesis is divided into two parts, as explained in Chapter 1, which focus on different aspects of marine ecological change. Part A considers marine Invasive Alien Species (IAS), which are taxa introduced outside of their native range. The detrimental consequences of invasions for human welfare n

  11. Invasive species unchecked by climate - response

    DEFF Research Database (Denmark)

    Burrows, Michael T.; Schoeman, David S.; Duarte, Carlos M.;

    2012-01-01

    Hulme points out that observed rates of range expansion by invasive alien species are higher than the median speed of isotherm movement over the past 50 years, which in turn has outpaced the rates of climate-associated range changes of marine and terrestrial species. This is not surprising, given...

  12. Urban Power Line Corridors as Novel Habitats for Grassland and Alien Plant Species in South-Western Finland.

    Science.gov (United States)

    Lampinen, Jussi; Ruokolainen, Kalle; Huhta, Ari-Pekka

    2015-01-01

    Regularly managed electric power line corridors may provide habitats for both early-successional grassland plant species and disturbance-dependent alien plant species. These habitats are especially important in urban areas, where they can help conserve native grassland species and communities in urban greenspace. However, they can also provide further footholds for potentially invasive alien species that already characterize urban areas. In order to implement power line corridors into urban conservation, it is important to understand which environmental conditions in the corridors favor grassland species and which alien species. Likewise it is important to know whether similar environmental factors in the corridors control the species composition of the two groups. We conducted a vegetation study in a 43 kilometer long urban power line corridor network in south-western Finland, and used generalized linear models and distance-based redundancy analysis to determine which environmental factors best predict the occurrence and composition of grassland and alien plant species in the corridors. The results imply that old corridors on dry soils and steep slopes characterized by a history as open areas and pastures are especially suitable for grassland species. Corridors suitable for alien species, in turn, are characterized by productive soils and abundant light and are surrounded by a dense urban fabric. Factors controlling species composition in the two groups are somewhat correlated, with the most important factors including light abundance, soil moisture, soil calcium concentration and soil productivity. The results have implications for grassland conservation and invasive alien species control in urban areas.

  13. Comparing functional similarity between a native and an alien slug in temperate rain forests of British Columbia

    Directory of Open Access Journals (Sweden)

    Mariano A. Rodriguez-Cabal

    2015-04-01

    Full Text Available The impacts of invasive alien species are greatest when they become dominant members of a community, introduce novel traits, and displace native species. Invasions by alien mollusks represent a novel context by which to compare trait differences between generalist native and introduced herbivores in terrestrial ecosystems. Here, we determined the abundance, habitat, feeding preferences, as well as the metabolic rate of the native Pacific banana slug (Ariolimax columbianus and the alien black slug (Arion rufus in the coastal forests of British Columbia, Canada. Through a series of observational and experimental studies, we found that alien slugs are more abundant, differ in their habitat preferences, and consumed more fungi (mushrooms than native banana slugs. Conversely, in an enclosures experiment we found that herbivory damage by native slugs was higher compared to enclosures with alien only and control enclosures. Finally, metabolic rates were similar for both slug species. These results suggest that alien black slugs possess a suite of traits that make them functionally different from native banana slugs.

  14. Index of Alien Impact: A method for evaluating potential ecological impact of alien plant species

    Science.gov (United States)

    Alien plant species are stressors to ecosystems and indicators of reduced ecosystem integrity. The magnitude of the stress reflects not only the quantity of aliens present, but also the quality of their interactions with native ecosystems. We develop an Index of Alien Impact (IAI...

  15. Alienation in educational organizations and its’ management

    Directory of Open Access Journals (Sweden)

    Pınar Sarpkaya

    2009-09-01

    Full Text Available The purpose of this study was to study the alienation in educational organizations carefully and to call attention to this subject which was studied insufficiently. Descriptive method was used in the study. The concept of alienation was brought up with philosophical and sociological principals and then common inferences about the educational organizations were made within the help of studies which were about the alienation in educational institutions. Hegel was the first to consider the fact of “alienation” philosophically in his book “Phenomenology of Spirit ”. To Hegel human history is also the history of human being’s becoming alienated to himself. After Hegel, Ludwig Feuerbach considered this fact in his book “Essence of Christianity” in 1841. According to Marx, alienation is a compulsory phase that development of human being must have. Marx emphasizes that in capitalist society which is named as modern society man with his labor in production relations becomes alienated to his labor, then to his social relationships, and finally to himself. In his opinion, man is desired to pull in to the consumption helical that is obstinately insisted as necessity. In this way, consumption and dissatisfaction are two elements which set off and product each other. Alienation is deterioration and decay conceit of human existence’s natural, social, psychological and cultural dimensions. It is human being’s separating from each other and becoming alienated to each other. In this respect, alienation means that man survives by becoming distant to himself, to the product he produces, to his natural, social, psychological and cultural environment but under the control of their dominance and decisiveness. Seeman distinguishes alienation into five; Powerlessness, Meaninglessness, Normlessness, Isolation and self-estrangement. The studies that are made in educational organizations about alienation focus on alienation of teacher and student. There

  16. Alienation in educational organizations and its’ management

    Directory of Open Access Journals (Sweden)

    Sadi Yılmaz

    2009-09-01

    Full Text Available The purpose of this study was to study the alienation in educational organizations carefully and to call attention to this subject which was studied insufficiently. Descriptive method was used in the study. The concept of alienation was brought up with philosophical and sociological principals and then common inferences about the educational organizations were made within the help of studies which were about the alienation in educational institutions. Hegel was the first to consider the fact of “alienation” philosophically in his book “Phenomenology of Spirit  ”. To Hegel human history is also the history of human being’s becoming alienated to himself. After Hegel, Ludwig Feuerbach considered this fact in his book “Essence of Christianity” in 1841. According to Marx, alienation is a compulsory phase that development of human being must have. Marx emphasizes that in capitalist society which is named as modern society man with his labor in production relations becomes alienated to his labor, then to his social relationships, and finally to himself. In his opinion, man is desired to pull in to the consumption helical that is obstinately insisted as necessity. In this way, consumption and dissatisfaction are two elements which set off and product each other. Alienation is deterioration and decay conceit of human existence’s natural, social, psychological and cultural dimensions. It is human being’s separating from each other and becoming alienated to each other. In this respect, alienation means that man survives by becoming distant to himself, to the product he produces, to his natural, social, psychological and cultural environment but under the control of their dominance and decisiveness. Seeman distinguishes alienation into five; Powerlessness, Meaninglessness, Normlessness, Isolation and self-estrangement. The studies that are made in educational organizations about alienation focus on alienation of teacher and student. There

  17. NEW CONTRIBUTION TO THE STUDY OF ALIEN FLORA IN ROMANIA

    Directory of Open Access Journals (Sweden)

    SÎRBU CULIŢĂ

    2011-12-01

    Full Text Available In this paper, a number of seventeen alien plant species are presented, one of them being now for the first time reported in Romania (Sedum sarmentosum Bunge. Some species are mentioned for the first time in the flora of Moldavia (Aster novae-angliae L., Cenchrus incertus M. A. Curtis, Chenopodium pumilio R. Br., Fraxinus americana L., Lindernia dubia (L. Pennell, Petunia × atkinsiana D. Don, Solidago gigantea Aiton, Tagetes erecta L. or Transylvania (Kochia sieversiana (Pallas C. A. Mey., and some are reported from new localities (seven species. For each species, there are presented general data on the geographical origin, its distribution in Europe and worldwide, as well as its invasion history and current distribution in Romania. Some of these species manifest a remarkable spreading tendency, expanding their invasion area in Romania. Voucher specimens were deposited in the Herbarium of University of Agricultural Sciences and Veterinary Medicine Iaşi (IASI.

  18. ELNAIS meets EASIN: distribution of marine alien species in Greece using EASIN mapping services and ELNAIS spatial data

    Directory of Open Access Journals (Sweden)

    S. KATSANEVAKIS

    2013-04-01

    Full Text Available The European Alien Species Information Network (EASIN was created with the aim to provide easy access to accurate information on alien species in Europe. EASIN allows the retrieval of spatial information from existing online data providers in order to produce integrated georeferenced distribution maps of alien species in Europe. In November 2012, a new data provider, the Ellenic Network on Aquatic Invasive Species (ELNAIS, joined EASIN; this has significantly increased the available georeferenced information on marine/estuarine alien species in Greek waters. Here, we use maps created by EASIN to show differences in patterns of distribution in Greece for the most abundant Phyla of marine alien species - Mollusca, Arthropoda, Chordata and Annelida. We also show that the two main pathways of introduction of marine alien species (Lessepsian migration and Shipping are related to different patterns of species spatial distribution in Greece. Overall, the tools provided by EASIN can greatly aid scientists and policy makers in obtaining high quality information on marine alien species in Greece, especially after the association with ELNAIS.

  19. 农林外来有害生物红火蚁入侵的问题建构与社会管理研究%A Study on Problems Construction and Social Management of Invasion of the Invasive Alien Species Solenpsisinvicta

    Institute of Scientific and Technical Information of China (English)

    张波; 罗映鹏; 雷益勤; 王艳玲; 骆小华; 黄秀颖; 向安强

    2015-01-01

    Solenpsisinvicta is the main invasive species in China and it is also one of the most damaging invasive species in the list of International Union for Conservation of Nature and Natural Resources. It is a pest which is detrimental to human or human concerns including agriculture, commercialtrade and travel. Applying the social construction theory within sociology of environment, the article aims to analyze the occurrence of invasion of Solenpsisinvicta. The goal is to study how has the invasion of the Solenpsisinvicta been constructed a problem in China, from the perspective of media, environment and its control. The article also tries to explore countermeasure of Splenpsisinvicta and the mechanism of the social management in the context of social science and natural science.%红火蚁是中国主要外来入侵物种,也是世界自然保护联盟收录的最具破坏力的入侵生物之一,它是一种危害农业生产、影响人民生活和旅游贸易的检疫性有害生物。利用环境社会学的问题建构理论,分析红火蚁入侵问题的发生机理,从媒体传播方式、红火蚁危害性、环境主张等方面,论证红火蚁入侵问题的建构过程;从自然科学与社会科学两方面,探讨相关问题的防范措施和社会管理机制。

  20. The assessment of hull fouling as a mechanism for the introduction and dispersal of alien species in the main Hawaiian Islands through surveys at harbors on Oahu's Southern and Southwestern Coasts during 2003 (NODC Accession 0001455)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Surveys for adult invertebrates that were part of the hull fouling communities were done to determine to what extent marine alien invasive species (AIS) are being...

  1. The assessment of hull fouling as a mechanism for the introduction and dispersal of marine alien species in the main Hawaiian Islands through surveys at harbors on Oahu's southern and southwestern coasts during 2003 (NODC Accession 0001455)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Surveys for adult invertebrates that were part of the hull fouling communities were done to determine to what extent marine alien invasive species (AIS) are being...

  2. Survey of roadside alien plants in Hawai`i Volcanoes National Park and adjacent residential areas 2001-2005

    Science.gov (United States)

    Bio, Keali'i F.; Pratt, Linda W.; Jacobi, James D.

    2012-01-01

    The sides of all paved roads of Hawai`i Volcanoes National Park (HAVO) were surveyed on foot in 2001 to 2005, and the roadside presence of 240 target invasive and potentially invasive alien plant species was recorded in mile-long increments. Buffer zones 5–10 miles (8–16 km) long along Highway 11 on either side of the Kīlauea and Kahuku Units of the park, as well as Wright Road that passed by the disjunct `Ōla`a Tract Unit, were included in the survey. Highway 11 is the primary road through the park and a major island thoroughfare. Three residential subdivisions adjacent to the park were similarly surveyed in 0.5–1 mile (0.8–1.6 km) intervals in 2003, and data were analyzed separately. Two roads to the east and northeast were also surveyed, but data from these disjunct areas were analyzed separately from park roads. In total, 174 of the target alien species were observed along HAVO roads and buffers, exclusive of residential areas, and the mean number of target aliens per mile surveyed was 20.6. Highway 11 and its buffer zones had the highest mean number of target alien plants per mile (26.7) of all park roads, and the Mauna Loa Strip Road had the lowest mean (11.7). Segments of Highway 11 adjacent to HAVO and Wright Road next to `Ōla`a Tract had mean numbers of target alien per mile (24–47) higher than those of any internal road. Alien plant frequencies were summarized for each road in HAVO. Fifteen new records of vascular plants for HAVO were observed and collected along park roads. An additional 28 alien plant species not known from HAVO were observed along the buffer segments of Highway 11 adjacent to the park. Within the adjacent residential subdivisions, 65 target alien plant species were sighted along roadsides. At least 15 potentially invasive species not currently found within HAVO were observed along residential roads, and several other species found there have been previously eliminated from the park or controlled to remnant populations

  3. INVENTORY OF THE INVASIVE ALIE N PLANT SPECIES IN INDONESIA

    Directory of Open Access Journals (Sweden)

    SRI S UDARMIYATI T JITROSOEDIRDJO

    2005-01-01

    Full Text Available An inventory of the alien plant species in Indone sia based on the existing references and herbarium specimens concluded that 1936 alien plant species ar e found in Indonesia which belong to 187 families. Field studies should be done to get the complete figur es of alien plant species in Indonesia. Based on the existing figures of the plant species, the invasive alien plant species can be iden tified, followed by studies on the assessment of losses, biology, management and their possible utilizations. Alien plant species are imported to Indonesia for cultivation, collection of the botanical garden, as experimental plants or other curiosities. Aside from plants purposely imported, there are also introduced plant propagules conta-minating imported agricultural products. These alien plant species can be beneficial or have a potential of being invasive. The alien cultivated species consisted of 67% of the total number. More than half of the cultivated plants are ornamental plants. Some of th e species are naturalized or escaped from cultivation and become wild and invasive. Some other natura lized species, adapted well without any problems of invasion. There are 339 species or 17% of the species r ecorded as weeds. The highest record of weeds is found in the family of Poaceae (57 species, follo wed by Asteraceae (53 species and Cyperaceae (35 species. There are 6 families having more than 10 species of weeds: Amaranthaceae, Asteraceae, Cyperaceae, Euphorbiaceae, Poaceae, and Rubiaceae. Three families have more than 100 species: Asteraceae 162 species, Poaceae 120 species, and Papillionaceae 103 species. Five species of aquatic and 20 species of terrestrial plants considered as important alien plant species in Indonesia were identified and some of their distributions noted

  4. Papahanaumokuakea - Laysan Island Invasive Plant Monitoring and Control with Volunteers 2012

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This project supports restoration activities at Laysan Island. Staff and volunteers continue efforts to eradicate alien invasive species Indian dropseed (Sporobolus...

  5. Will climate change promote future invasions?

    Science.gov (United States)

    Bellard, C.; Thuiller, W.; Leroy, B.; Genovesi, P.; Bakkenes, M.; Courchamp, F.

    2013-01-01

    Biological invasion is increasingly recognized as one of the greatest threats to biodiversity. Using ensemble forecasts from species distribution models to project future suitable areas of the “100 of the world’s worst invasive species” defined by the IUCN, we show that both climate and land use changes will likely cause drastic species range shifts. Looking at potential spatial aggregation of invasive species, we identify three future hotspots of invasion in Europe, northeastern North America, and Oceania. We also emphasize that some regions could lose a significant number of invasive alien species, creating opportunities for ecosystem restoration. From the list of 100, scenarios of potential range distributions show a consistent shrinking for invasive amphibians and birds, while for aquatic and terrestrial invertebrates distributions are projected to substantially increase in most cases. Given the harmful impacts these invasive species currently have on ecosystems, these species will likely dramatically influence the future of biodiversity. PMID:23913552

  6. An updated review of alien species on the coasts of Turkey

    Directory of Open Access Journals (Sweden)

    M.E. CINAR

    2012-12-01

    Full Text Available This 2010 review of alien species along the coasts of Turkey represents a total of 400 alien species belonging to 14 systematic groups. The present paper also reports the first findings ofVanderhorstia mertensi in the Aegean Sea (Gökova Bay, Chama adspersa in the Sea of Marmara andMya arenaria in the Aegean Sea. A total of 124 new alien species was determined within the last 5 years. Mollusca had the highest number of species (105 species, followed by Polychaeta (75 species, Crustacea (64 species and Pisces (58 species. The highest number of alien species (330 species were encountered on the Levantine coast of Turkey, followed by the Aegean Sea (165 species, Sea of Marmara (69 species and Black Sea (20 species. The Suez Canal (66% of the total number of alien species is the main vector for species introductions to the coasts of Turkey, followed by the ship-mediated transport (30%. The majority of species (306 species, 76% of total number of species have become established in the area, while 59 species are classified as casual (15%, 23 species as questionable (6% and 13 species as cryptogenic (3%. One new alien species was introduced to the coasts of Turkey every 4 weeks between 1991 and 2010. The majority of aliens were found on soft substratum (198 species in shallow waters (0-10 m (319 species. Some species such asCaulerpa racemosa, Amphistegina lobifera, Amphisorus hemprichii, Rhopilema nomadica, Mnemiopsis leidyi, Hydroides spp., Ficopomatus enigmaticus, Charybdis longicollis, Rapana venosa, Asterias rubens, Siganus spp. and Lagocephalus sceleratus show high invasive characters, and have great impacts both on the prevailing ecosystems and humans.

  7. Alien Phytogeographic Regions of Southern Africa: Numerical Classification, Possible Drivers, and Regional Threats

    Science.gov (United States)

    Hugo, Sanet; Van Rensburg, Berndt J.; Van Wyk, Abraham E.; Steenkamp, Yolande

    2012-01-01

    The distributions of naturalised alien plant species that have invaded natural or semi-natural habitat are often geographically restricted by the environmental conditions in their new range, implying that alien species with similar environmental requirements and tolerances may form assemblages and characterise particular areas. The aim of this study was to use objective numerical techniques to reveal any possible alien phytogeographic regions (i.e. geographic areas with characteristic alien plant assemblages) in southern Africa. Quarter degree resolution presence records of naturalised alien plant species of South Africa, Lesotho, Swaziland, Namibia and Botswana were analysed through a divisive hierarchical classification technique, and the output was plotted on maps for further interpretation. The analyses revealed two main alien phytogeographic regions that could be subdivided into eight lower level phytogeographic regions. Along with knowledge of the environmental requirements of the characteristic species and supported by further statistical analyses, we hypothesised on the main drivers of alien phytogeographic regions, and suggest that environmental features such as climate and associated biomes were most important, followed by human activities that modify climatic and vegetation features, such as irrigation and agriculture. Most of the characteristic species are not currently well-known as invasive plant species, but many may have potential to become troublesome in the future. Considering the possibility of biotic homogenization, these findings have implications for predicting the characteristics of the plant assemblages of the future. However, the relatively low quality of the dataset necessitates further more in-depth studies with improved data before the findings could be directly beneficial for management. PMID:22574145

  8. An extensive alien plant inventory from the inhabited areas of galapagos.

    Directory of Open Access Journals (Sweden)

    Anne Guézou

    Full Text Available BACKGROUND: Plant invasions are causing habitat degradation in Galapagos. Problems are concentrated on the four inhabited islands. Plants introduced to rural areas in the humid highlands and urban areas on the arid coast act as foci for invasion of the surrounding Galapagos National Park. METHODOLOGY/PRINCIPAL FINDINGS: Here we present results of the most comprehensive inventory to date of alien vascular plants in the inhabited areas of Galapagos. The survey was conducted between 2002 and 2007, in 6031 properties (97% of the total on Floreana, Isabela, San Cristobal and Santa Cruz Islands. In total 754 alien vascular plant taxa were recorded, representing 468 genera in 123 families. Dicotyledons represented 554 taxa, monocotyledons 183, there were 7 gymnosperms and 10 pteridophytes. Almost half (363 of the taxa were herbaceous. The most represented families were Fabaceae (sensu lato, Asteraceae and Poaceae. The three most recorded species in the humid rural areas were Psidium guajava, Passiflora edulis and Bryophyllum pinnatum, and in the dry urban areas, Aloe vera, Portulaca oleracea and Carica papaya. In total, 264 (35% taxa were recorded as naturalized. The most common use for taxa was ornamental (52%. CONCLUSIONS/SIGNIFICANCE: This extensive survey has increased the known alien vascular flora of Galapagos by 257 species, giving a ratio of alien to native taxa of 1.57:1. It provides a crucial baseline for plant invasion management in the archipelago and contributes data for meta analyses of invasion processes worldwide. A repeat of the survey in the future would act as an effective early detection tool to help avoid further invasion of the Galapagos National Park.

  9. Fanon and the Problem of Alienation.

    Science.gov (United States)

    Kessous, Naaman

    1987-01-01

    The notion of alienation as presented in the writings of Frantz Fanon needs a theoretical analysis which considers its economic, racial and political aspects. Marx wrote on alienation in a similar way portraying it as a self-fulfilling prophecy which is fraught with violence and dehumanization. (VM)

  10. Alienation and the Four Worlds of Childhood.

    Science.gov (United States)

    Bronfenbrenner, Urie

    1986-01-01

    Outlines the four worlds of childhood and the ways that alienation in adolescents can be counteracted through the creation of interconnecting links. The risks of losing youths to alienating factors caused by institutions, the social structure, and the pressures under which schools and families function is the highest it has ever been. (MD)

  11. Alienation, Mass Society and Mass Culture.

    Science.gov (United States)

    Dam, Hari N.

    This monograph examines the nature of alienation in mass society and mass culture. Conceptually based on the "Gemeinschaft-Gesellschaft" paradigm of sociologist Ferdinand Tonnies, discussion traces the concept of alienation as it appears in the philosophies of Hegel, Marx, Kierkegaard, Sartre, and others. Dwight Macdonald's "A Theory of Mass…

  12. Update of alien fauna and new records from Tunisian marine waters

    Directory of Open Access Journals (Sweden)

    K. OUNIFI- BEN AMOR

    2014-06-01

    Full Text Available An updated inventory of alien marine fauna in coastal and offshore Tunisian waters is presented. Records were compiled from scientific and ‘grey’ publications, presentations at scientific meetings, theses presented in fulfillment of requirements towards MSc and PhD degrees, websites and personal observations. 136 alien species were recorded in Tunisian waters, 60 records in northern coasts, West Mediterranean and 76 in central and southern coasts, Central Mediterranean. Nearly half of the first sightings in Tunisian waters took place in the Gulf of Gabès. The dominant taxa are Crustancean (24%, Molluscs (23%, Fishes (19% and Annelida (13%. Twenty one species previously reported as aliens, were upon consideration, reclassified as range-expanding Atlantic species. Amathia verticillata, previously considered native to the Mediterranean, is reclassified as pseudoindigenous. Twenty one alien species are newly recorded from Tunisia, including 5 fish species, 5 polychaetes, 4 crustaceans, 4 molluscs, and one each schyphozoan, bryozoan and tunicate. The findings of Gibberulus gibberulus albus, Morula aspera and Calcinus latens, three species new to the Mediterranean, and of Actaedoes tomentosus, reported for the second time in the basin, are described. Species were classified according to their establishment status and their origins. This contribution highlights the dual origin of biological invasion in Tunisian waters (Red Sea and Atlantic, with slightly more species of Red Sea and Indo-Pacific origin (61,76%.  The impact of the alien species in Tunisian waters was discussed.

  13. Alien invasions in Antarctica—is anyone liable?

    Directory of Open Access Journals (Sweden)

    Kevin A. Hughes

    2014-05-01

    Full Text Available The introduction of non-native species to Antarctica in association with human activities is a major threat to indigenous biodiversity and the region's unique ecosystems, as has been well-demonstrated in other ecosystems globally. Existing legislation contained in the Protocol on Environmental Protection to the Antarctic Treaty does not specifically make the eradication of non-native species mandatory, although it is implicit that human-assisted introductions should not take place. Furthermore, to date, eradications of non-native species in the Treaty area have been infrequent and slow to progress. In 2005 an additional Annex (VI to the Protocol was agreed concerning “Liability arising from environmental emergencies.” This annex focusses on prevention of environmental emergencies, contingency planning and reclaiming costs incurred when responding to an environmental emergency caused by another operator within the Antarctic Treaty area. However, the types of environmental emergencies covered by the annex are not defined. In this paper we highlight potential difficulties with the application of Annex VI in the context of non-native species control and eradication, including, for example, whether a non-native species introduction would be classified as an “environmental emergency” and therefore be considered under the terms of the annex. Even if this were the case, we conclude that the slow pace of approval of the annex by Antarctic Treaty Parties may prevent it coming into force for many years and, once in force, in its current form it is unlikely to be useful for reclaiming costs associated with the eradication or management of a non-native species.

  14. Non-Newtonian Effects of Second-Order Fluids on the Hydrodynamic Lubrication of Inclined Slider Bearings.

    Science.gov (United States)

    Apparao, Siddangouda; Biradar, Trimbak Vaijanath; Naduvinamani, Neminath Bhujappa

    2014-01-01

    Theoretical study of non-Newtonian effects of second-order fluids on the performance characteristics of inclined slider bearings is presented. An approximate method is used for the solution of the highly nonlinear momentum equations for the second-order fluids. The closed form expressions for the fluid film pressure, load carrying capacity, frictional force, coefficient of friction, and centre of pressure are obtained. The non-Newtonian second order fluid model increases the film pressure, load carrying capacity, and frictional force whereas the center of pressure slightly shifts towards exit region. Further, the frictional coefficient decreases with an increase in the bearing velocity as expected for an ideal fluid.

  15. Troubling travellers: are ecologically harmful alien species associated with particular introduction pathways?

    Directory of Open Access Journals (Sweden)

    Jan Pergl

    2017-01-01

    Full Text Available Prioritization of introduction pathways is seen as an important component of the management of biological invasions. We address whether established alien plants, mammals, freshwater fish and terrestrial invertebrates with known ecological impacts are associated with particular introduction pathways (release, escape, contaminant, stowaway, corridor and unaided. We used the information from the European alien species database DAISIE (www.europe-aliens.org supplemented by the EASIN catalogue (European Alien Species Information Network, and expert knowledge. Plants introduced by the pathways release, corridor and unaided were disproportionately more likely to have ecological impacts than those introduced as contaminants. In contrast, impacts were not associated with particular introduction pathways for invertebrates, mammals or fish. Thus, while for plants management strategies should be targeted towards the appropriate pathways, for animals, management should focus on reducing the total number of taxa introduced, targeting those pathways responsible for high numbers of introductions. However, regardless of taxonomic group, having multiple introduction pathways increases the likelihood of the species having an ecological impact. This may simply reflect that species introduced by multiple pathways have high propagule pressure and so have a high probability of establishment. Clearly, patterns of invasion are determined by many interacting factors and management strategies should reflect this complexity.

  16. Alien encounter a scientific novel

    CERN Document Server

    Schulze-Makuch, Dirk

    2014-01-01

    It has been nearly 100 years since the Apollo moon landings, when Jack and Vladimir, two astronauts on a mission to Venus, discover a mysterious void related to indigenous life on the planet. Subsequently more voids are detected on Earth, Mars, Titan, and, quite ominously, inside a planetoid emerging from the Kuiper belt. Jack is sent to investigate the voids in the Solar System and intercept the planetoid - which, as becomes increasingly clear, is inhabited by alien life forms. Jack and his crew will have little time to understand their alien biochemistry, abilities, behavior patterns, resilience, and technology, but also how these life forms relate to the voids. Humankind's first encounter with these exotic life forms couldn't be more fateful, becoming a race against time to save life on Earth and to reveal the true nature of the voids, which seem to be intrinsically related to life and the universe itself. In this novel, the author combines many topics related to state-of-the-art research in the field of...

  17. Alien seas oceans in space

    CERN Document Server

    Lopes, Rosaly

    2013-01-01

    In the early days of planetary observation, oceans were thought to exist in all corners of the Solar System. Carbonated seas percolated beneath the clouds of Venus. Features on the Moon's surface were given names such as "the Bay of Rainbows” and the "Ocean of Storms." With the advent of modern telescopes and spacecraft exploration these ancient concepts of planetary seas have been replaced by the reality of something even more exotic. Alien Seas serves up the current research, past beliefs, and new theories to offer a rich array of the "seas" on other worlds. It is organized by location and by the material composing the oceans under discussion, with expert authors penning chapters on their  specialty. Each chapter features new original art depicting alien seas, as well as the latest ground-based and spacecraft images. With the contributors as guides, readers can explore the wild seas of Jupiter's watery satellite Europa, believed similar in composition to battery acid. Saturn's planet-sized moon Titan see...

  18. Invasions by ladybugs, ladybirds, and other predatory Coleoptera

    OpenAIRE

    Evans, Edward W.; Soares, António O.; Yasuda, Hironori

    2011-01-01

    Copyright © International Organization for Biological Control (IOBC) 2011. Species of predatory Coleoptera have become abundant in new geographic regions recently, raising concerns for invaded ecosystems. We address this topic by focusing on invasive alien ladybird beetles (Coccinellidae; known also as ladybugs). Humans appear directly or indirectly responsible for all or most ladybird invasions. Factors hypothesized to have promoted ladybird invasions include genetic diversity (e.g., for ...

  19. Growth-form and spatiality driving the functional difference of native and alien aquatic plants in Europe.

    Science.gov (United States)

    Lukács, Balázs A; Vojtkó, Anna E; Mesterházy, Attila; Molnár V, Attila; Süveges, Kristóf; Végvári, Zsolt; Brusa, Guido; Cerabolini, Bruno E L

    2017-02-01

    Trait-based approaches are widely used in community ecology and invasion biology to unravel underlying mechanisms of vegetation dynamics. Although fundamental trade-offs between specific traits and invasibility are well described among terrestrial plants, little is known about their role and function in aquatic plant species. In this study, we examine the functional differences of aquatic alien and native plants stating that alien and native species differ in selected leaf traits. Our investigation is based on 60 taxa (21 alien and 39 native) collected from 22 freshwater units of Hungarian and Italian lowlands and highlands. Linear mixed models were used to investigate the effects of nativeness on four fundamental traits (leaf area, leaf dry matter content, specific leaf area, and leaf nitrogen content), while the influence of growth-form, altitude, and site were employed simultaneously. We found significantly higher values of leaf areas and significantly lower values of specific leaf areas for alien species if growth-form was included in the model as an additional predictor.We showed that the trait-based approach of autochthony can apply to aquatic environments similar to terrestrial ones, and leaf traits have relevance in explaining aquatic plant ecology whether traits are combined with growth-forms as a fixed factor. Our results confirm the importance of traits related to competitive ability in the process of aquatic plant invasions. Alien aquatic plants can be characterized as species producing soft leaves faster. We argue that the functional traits of alien aquatic plants are strongly growth-form dependent. Using the trait-based approach, we found reliable characteristics of aquatic plants related to species invasions, which might be used, for example, in conservation management.

  20. Biological Invasion Risks and the Public Good: an Economic Perspective

    Directory of Open Access Journals (Sweden)

    Jason Shogren

    2002-06-01

    Full Text Available We postulate that the causes of the problem of invasive alien species are primarily economic and, as such, require economic solutions. Invasive alien species are of increasing concern for four reasons. First, introductions are increasing sharply, while mechanisms for excluding or eradicating alien species have been either withdrawn or progressively weakened. Both trends are due to the liberalization of and increase in international travel and trade, an economic phenomenon. Second, the costs of invasions are rising rapidly due partly to increasing human population density, and partly to increasing intensity of production in genetically impoverished agricultural systems. Third, biological invasions are associated with a high degree of uncertainty both because they involve novel interactions, and because invasion risks are endogenous. Actual risks depend on how people react to the possibility of invasions. Fourth, the exclusion and control of invasive species is a "weakest-link" public good. This places the well-being of society in the hands of the least effective provider. We argue that an economic solution to the problem of invasive species has two components. One is to use incentives to change human behavior so as to enhance protection against the introduction, establishment, and spread of invasive behavior. The other is to develop institutions that support the weakest members of global society, converting a "weakest-link" to a "best-shot" public good.

  1. A conceptual framework for invasion in microbial communities

    KAUST Repository

    Kinnunen, Marta

    2016-05-03

    There is a growing interest in controlling-promoting or avoiding-the invasion of microbial communities by new community members. Resource availability and community structure have been reported as determinants of invasion success. However, most invasion studies do not adhere to a coherent and consistent terminology nor always include rigorous interpretations of the processes behind invasion. Therefore, we suggest that a consistent set of definitions and a rigorous conceptual framework are needed. We define invasion in a microbial community as the establishment of an alien microbial type in a resident community and argue how simple criteria to define aliens, residents, and alien establishment can be applied for a wide variety of communities. In addition, we suggest an adoption of the community ecology framework advanced by Vellend (2010) to clarify potential determinants of invasion. This framework identifies four fundamental processes that control community dynamics: dispersal, selection, drift and diversification. While selection has received ample attention in microbial community invasion research, the three other processes are often overlooked. Here, we elaborate on the relevance of all four processes and conclude that invasion experiments should be designed to elucidate the role of dispersal, drift and diversification, in order to obtain a complete picture of invasion as a community process.

  2. A conceptual framework for invasion in microbial communities.

    Science.gov (United States)

    Kinnunen, Marta; Dechesne, Arnaud; Proctor, Caitlin; Hammes, Frederik; Johnson, David; Quintela-Baluja, Marcos; Graham, David; Daffonchio, Daniele; Fodelianakis, Stilianos; Hahn, Nicole; Boon, Nico; Smets, Barth F

    2016-12-01

    There is a growing interest in controlling-promoting or avoiding-the invasion of microbial communities by new community members. Resource availability and community structure have been reported as determinants of invasion success. However, most invasion studies do not adhere to a coherent and consistent terminology nor always include rigorous interpretations of the processes behind invasion. Therefore, we suggest that a consistent set of definitions and a rigorous conceptual framework are needed. We define invasion in a microbial community as the establishment of an alien microbial type in a resident community and argue how simple criteria to define aliens, residents, and alien establishment can be applied for a wide variety of communities. In addition, we suggest an adoption of the community ecology framework advanced by Vellend (2010) to clarify potential determinants of invasion. This framework identifies four fundamental processes that control community dynamics: dispersal, selection, drift and diversification. While selection has received ample attention in microbial community invasion research, the three other processes are often overlooked. Here, we elaborate on the relevance of all four processes and conclude that invasion experiments should be designed to elucidate the role of dispersal, drift and diversification, in order to obtain a complete picture of invasion as a community process.

  3. 45 CFR 1626.7 - Verification of eligible alien status.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 4 2010-10-01 2010-10-01 false Verification of eligible alien status. 1626.7... CORPORATION RESTRICTIONS ON LEGAL ASSISTANCE TO ALIENS § 1626.7 Verification of eligible alien status. (a) An alien seeking representation shall submit appropriate documents to verify eligibility, unless the...

  4. 45 CFR 233.52 - Overpayment to aliens.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 2 2010-10-01 2010-10-01 false Overpayment to aliens. 233.52 Section 233.52... ELIGIBILITY IN FINANCIAL ASSISTANCE PROGRAMS § 233.52 Overpayment to aliens. A State Plan under title IV-A of the Social Security Act, shall provide that: (a) Any sponsor of an alien and the alien shall...

  5. 45 CFR 1626.5 - Alien status and eligibility.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 4 2010-10-01 2010-10-01 false Alien status and eligibility. 1626.5 Section 1626... RESTRICTIONS ON LEGAL ASSISTANCE TO ALIENS § 1626.5 Alien status and eligibility. Subject to all other... may provide legal assistance to an alien who is present in the United States and who is within one...

  6. 26 CFR 1.871-3 - Residence of alien seamen.

    Science.gov (United States)

    2010-04-01

    ... 26 Internal Revenue 9 2010-04-01 2010-04-01 false Residence of alien seamen. 1.871-3 Section 1.871... (CONTINUED) INCOME TAXES Nonresident Aliens and Foreign Corporations § 1.871-3 Residence of alien seamen. In order to determine whether an alien seaman is a resident of the United States for purposes of the...

  7. 26 CFR 1.6654-6 - Nonresident alien individuals.

    Science.gov (United States)

    2010-04-01

    ... 26 Internal Revenue 13 2010-04-01 2010-04-01 false Nonresident alien individuals. 1.6654-6 Section....6654-6 Nonresident alien individuals. (a) In general. A nonresident alien individual is required to... gross income of a nonresident alien individual is such as to require making a payment of...

  8. 31 CFR 515.335 - Permanent resident alien.

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Permanent resident alien. 515.335... Definitions § 515.335 Permanent resident alien. As used in § 515.208, the term permanent resident alien means an alien lawfully admitted for permanent residence into the United States....

  9. 47 CFR 90.115 - Foreign government and alien eligibility.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Foreign government and alien eligibility. 90... government and alien eligibility. (a) No station authorization in the radio services governed by this part....9(c) of this chapter) if such entity is: (1) An alien or the representative of any alien; (2)...

  10. 8 CFR 1240.38 - Fingerprinting of excluded aliens.

    Science.gov (United States)

    2010-01-01

    ... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Fingerprinting of excluded aliens. 1240.38 Section 1240.38 Aliens and Nationality EXECUTIVE OFFICE FOR IMMIGRATION REVIEW, DEPARTMENT OF JUSTICE IMMIGRATION REGULATIONS PROCEEDINGS TO DETERMINE REMOVABILITY OF ALIENS IN THE UNITED STATES Exclusion...

  11. 28 CFR 0.47 - Alien property matters.

    Science.gov (United States)

    2010-07-01

    ... 28 Judicial Administration 1 2010-07-01 2010-07-01 false Alien property matters. 0.47 Section 0.47....47 Alien property matters. The Office of Alien Property shall be a part of the Civil Division: (a... Alien Property: (1) Exercising or performing all the authority, rights, privileges, powers, duties,...

  12. 7 CFR 273.4 - Citizenship and alien status.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 4 2010-01-01 2010-01-01 false Citizenship and alien status. 273.4 Section 273.4... and alien status. (a) Household members meeting citizenship or alien status requirements. No person is...)(4)(i) of this section, or (5) An individual who is both a qualified alien as defined in paragraph...

  13. 8 CFR 1241.20 - Aliens ordered excluded.

    Science.gov (United States)

    2010-01-01

    ... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Aliens ordered excluded. 1241.20 Section 1241.20 Aliens and Nationality EXECUTIVE OFFICE FOR IMMIGRATION REVIEW, DEPARTMENT OF JUSTICE IMMIGRATION REGULATIONS APPREHENSION AND DETENTION OF ALIENS ORDERED REMOVED Deportation of Excluded...

  14. 22 CFR 40.91 - Certain aliens previously removed.

    Science.gov (United States)

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Certain aliens previously removed. 40.91... IMMIGRANTS UNDER THE IMMIGRATION AND NATIONALITY ACT, AS AMENDED Aliens Previously Removed § 40.91 Certain aliens previously removed. (a) 5-year bar. An alien who has been found inadmissible, whether as a...

  15. 22 CFR 40.92 - Aliens unlawfully present.

    Science.gov (United States)

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Aliens unlawfully present. 40.92 Section 40.92... UNDER THE IMMIGRATION AND NATIONALITY ACT, AS AMENDED Aliens Previously Removed § 40.92 Aliens unlawfully present. (a) 3-year bar. An alien described in INA 212(a)(9)(B)(i)(I) shall be ineligible for...

  16. 8 CFR 274a.3 - Continuing employment of unauthorized aliens.

    Science.gov (United States)

    2010-01-01

    ... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Continuing employment of unauthorized aliens. 274a.3 Section 274a.3 Aliens and Nationality DEPARTMENT OF HOMELAND SECURITY IMMIGRATION REGULATIONS CONTROL OF EMPLOYMENT OF ALIENS Employer Requirements § 274a.3 Continuing employment...

  17. 8 CFR 1236.2 - Confined aliens, incompetents, and minors.

    Science.gov (United States)

    2010-01-01

    ... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Confined aliens, incompetents, and minors. 1236.2 Section 1236.2 Aliens and Nationality EXECUTIVE OFFICE FOR IMMIGRATION REVIEW, DEPARTMENT OF JUSTICE IMMIGRATION REGULATIONS APPREHENSION AND DETENTION OF INADMISSIBLE AND DEPORTABLE ALIENS;...

  18. 8 CFR 235.3 - Inadmissible aliens and expedited removal.

    Science.gov (United States)

    2010-01-01

    ... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Inadmissible aliens and expedited removal. 235.3 Section 235.3 Aliens and Nationality DEPARTMENT OF HOMELAND SECURITY IMMIGRATION REGULATIONS INSPECTION OF PERSONS APPLYING FOR ADMISSION § 235.3 Inadmissible aliens and expedited removal. (a)...

  19. 8 CFR 204.6 - Petitions for employment creation aliens.

    Science.gov (United States)

    2010-01-01

    ... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Petitions for employment creation aliens. 204.6 Section 204.6 Aliens and Nationality DEPARTMENT OF HOMELAND SECURITY IMMIGRATION REGULATIONS IMMIGRANT PETITIONS Immigrant Visa Petitions § 204.6 Petitions for employment creation aliens. (a)...

  20. Alienation in Irvine Welsh’s Trainspotting

    Directory of Open Access Journals (Sweden)

    B.A. Senekal

    2010-07-01

    Full Text Available This article examines how Melvin Seeman’s theory of alienation (1959 and modern alienation research manifest in Irvine Welsh’s “Trainspotting”. This is an important novel, not only because of its commercial success, but also because it depicts a specific marginalised subculture. Postmodernism and systems theory approaches, as well as changes in the social and political spheres have motivated researchers such as Geyer (1996, Kalekin-Fishman (1998 and Neal and Collas (2000 to reinterpret Seeman’s theory. This article attempts to incorporate this new theory of alienation in the analysis of contemporary fiction. Seeman identifies five aspects of alienation, namely powerlessness, meaninglessness, normlessness, social isolation and self-estrangement. Following Neal and Collas (2000, in particular, this article omits self-estrangement, but shows how the other four aspects of alienation have changed since Seeman’s formulation. It is argued that “Trainspotting” depicts a specific occurrence of alienation in modern western society, besides normlessness, meaninglessness, and social isolation, highlighting Seeman’s concept of powerlessness, in particular. The article further argues that applying Seeman’s theory of alienation in the study of contemporary literature provides a fresh theoretical approach that contributes to the understanding of how fiction engages with its environment.

  1. The alien terrestrial invertebrate fauna of the High Arctic archipelago of Svalbard: potential implications for the native flora and fauna

    Directory of Open Access Journals (Sweden)

    Stephen J. Coulson

    2015-09-01

    Full Text Available Experience from the Antarctic indicates that the establishment of alien species may have significant negative effects on native flora and fauna in polar regions and is considered to be amongst the greatest threats to biodiversity. But, there have been few similar studies from the Arctic. Although the terrestrial invertebrate inventory of the Svalbard Archipelago is amongst the most complete for any region of the Arctic, no consideration has yet been made of alien terrestrial invertebrate species, their invasiveness tendencies, threat to the native biology or their route of entry. Such baseline information is critical for appropriate management strategies. Fifteen alien invertebrate species have established in the Svalbard environment, many of which have been introduced via imported soils. Biosecurity legislation now prohibits such activities. None of the recorded established aliens yet show invasive tendencies but some may have locally negative effects. Ten species are considered to be vagrants and a further seven are classified as observations. Vagrants and the observations are not believed to be able to establish in the current tundra environment. The high connectivity of Svalbard has facilitated natural dispersal processes and may explain why few alien species are recorded compared to isolated islands in the maritime Antarctic. The vagrant species observed are conspicuous Lepidoptera, implying that less evident vagrant species are also arriving regularly. Projected climate change may enable vagrant species to establish, with results that are difficult to foresee.

  2. Rocky shores of a major southern African Marine Protected Area are almost free from intertidal invertebrate alien species

    Directory of Open Access Journals (Sweden)

    Hanlie Malherbe

    2014-02-01

    Full Text Available A major threat to marine ecosystems is the establishment and proliferation of invasive alien species. This study addresses gaps in our knowledge regarding marine alien invertebrate species in the Kogelberg Biosphere Reserve (KBR and adjacent Betty’s Bay Marine Protected Area (MPA in the Western Cape of South Africa, together a potentially important area for south-coast marine conservation. Understanding the distribution and geographical expansion of these species is critical for conservation planning. A quantitative systematic survey of the intertidal rocky shore region was undertaken. The mytilid Mediterranean mussel, Mytilus galloprovincialis, and the bryozoan Watersipora subtorquata were the only alien species recorded along the coastline, which included the MPA. The abundance of M. galloprovincialis was significantly higher outside the MPA, and the abundance of W. subtorquata was significantly higher inside the MPA. With only two alien species recorded, the Betty’s Bay MPA and its surroundings support relatively few marine alien species with regards to rocky shore invertebrate biodiversity. Conservation implications: It is important that the Betty’s Bay MPA and its adjacent coastline maintain its current status as an area with relatively few marine alien species. The conservation implications on management require routine surveys of this region to detect early introductions of any additional species.

  3. Alien Marine Species in the Mediterranean - the 100 ‘Worst Invasives’ and their Impact

    Directory of Open Access Journals (Sweden)

    N. STREFTARIS

    2012-12-01

    Full Text Available A number of marine alien species have been described as invasive or locally invasive in the Mediterranean because of their proliferation, and/or their geographical spread and/or impact on native populations. Based on that information and on the documented impact they have on the biodiversity and socioeconomics of the basin, a preliminary list of the 100 ‘worst’ Invasive Alien Species (IAS in the Mediterranean has been produced and presented in this work along with details on their impact. Emphasis is given to their impact on socioeconomics (fi sheries/aquaculture, health & sanitation, infrastructure & building, documented for 43 species. Such selection of the ‘worst’ IAS was diffi cult and controversial and is expected to attract much attention and scientifi c criticism since not only can the documentation of the impact of IAS be controversial, but also their inventory can be biased towards the effort and resources devoted to the study of the impact of certain species/taxonomic groups. Thus, while marine plants (phytobenthos and phytoplankton are fairly well studied, less attention has been paid to the impact of vertebrates and even less to invertebrates. Nevertheless, the list highlights the need for continued research on the issue (monitoring aliens and their impact for an integrated ecosystem based management approach over the entire area. The preliminary list can provide the basis for selecting indicator species within the Mediterranean and thus be the common ground to build cooperation about IAS within countries in the region.

  4. Understanding the biological invasion risk posed by the global wildlife trade: propagule pressure drives the introduction and establishment of Nearctic turtles.

    Science.gov (United States)

    García-Díaz, Pablo; Ross, Joshua V; Ayres, César; Cassey, Phillip

    2015-03-01

    Biological invasions are a key component of human-induced global change. The continuing increase in global wildlife trade has raised concerns about the parallel increase in the number of new invasive species. However, the factors that link the wildlife trade to the biological invasion process are still poorly understood. Moreover, there are analytical challenges in researching the role of global wildlife trade in biological invasions, particularly issues related to the under-reporting of introduced and established populations in areas with reduced sampling effort. In this work, we use high-quality data on the international trade in Nearctic turtles (1999-2009) coupled with a statistical modelling framework, which explicitly accounts for detection, to investigate the factors that influence the introduction (release, or escape into the wild) of globally traded Nearctic turtles and the establishment success (self-sustaining exotic populations) of slider turtles (Trachemys scripta), the most frequently traded turtle species. We found that the introduction of a species was influenced by the total number of turtles exported to a jurisdiction and the age at maturity of the species, while the establishment success of slider turtles was best associated with the propagule number (number of release events), and the number of native turtles in the jurisdiction of introduction. These results indicate both a direct and indirect association between the wildlife trade and the introduction of turtles and establishment success of slider turtles, respectively. Our results highlight the existence of gaps in the number of globally recorded introduction events and established populations of slider turtles, although the expected bias is low. We emphasize the importance of researching independently the factors that affect the different stages of the invasion pathway. Critically, we observe that the number of traded individuals might not always be an adequate proxy for propagule pressure

  5. The mechanism of PTFE and PE friction deposition: a combined scanning electron and scanning force microscopy study on highly oriented polymeric sliders

    NARCIS (Netherlands)

    Schaeben, H.; Vancso, G. Julius

    1998-01-01

    The mechanism of friction deposition of polytetrafluoroethylene (PTFE) and polyethylene (PE) was studied by scanning electron (SEM) and scanning force microscopy (SFM) on the worn surfaces of PTFE and PE sliders that were used in friction deposition on glass substrates. These surfaces exhibited a fi

  6. Traits of reproductive biology associated with invasiveness in alien invasive plant Phytolacca americana%外来入侵植物美洲商陆的繁殖生物学特性及其与入侵性的关系

    Institute of Scientific and Technical Information of China (English)

    周兵; 闫小红; 肖宜安; 张争光; 李晓红; 杨佳琴

    2013-01-01

    Phytolacca americana is one of the widespread invasive weeds in Phytolaccaceae in China. The reproductive traits of this species such as phenology of flowering, floral syndrome, breeding system and seed germination characteristics were studied by experimental observation and bagging treatment to assess the association of these reproductive traits with invasiveness. P. americana flowered during June to August every year in Ji’an city. The lifespan of a single capitulum was approximately 6 to 7 days, 2 to 4 days for a single flower. The diameter, stamen length, style length and stigma diameter were (6.43 ± 0.15), (2.83 ± 0.10), (0.92 ± 0.06) and (1.02 ± 0.08) mm respectively. Bagged flowers without emasculation showed high maturing rate (93.33±1.92)% which means a high self-compatibility, but it also exhibited a certain cross-compatibility with a maturing rate of (42.22±2.22)% in the emasculation treatment, its P/O ratio was 372.37 ± 31.24, and out-crossing index was 3, which suggests that the breeding system of P. americana is facultative selfing, and sometimes needs pollinators. The main floral visitors were insects of Apidae, Vespidae, Sarcophagidae, Syrphidae. The thousand seed weight was 6.43 g, the seed emerged relatively lowly, but orderly and with a long life activity. Our experimental findings suggested that the reproductive traits such as the versatile mating system of self- and cross-pollination, high seed production, long seed life span and strong asexual capacity might contribute to the invasive capability of P. americana.%  美洲商陆(Phytolacca americana)是一种我国广泛分布的商陆科入侵植物。通过实验观察和人工控制套袋等方法,对其开花动态、花部综合特征、繁育系统和种子萌发率等与繁殖相关的特性进行了研究,探讨了这些繁殖特性与入侵性的关系。结果表明,美洲商陆每年6—8月开花,单花序的花期为6~7 d,单花的花期为2~4 d。其花

  7. AliEn - EDG Interoperability in ALICE

    CERN Document Server

    Bagnasco, S; Buncic, P; Carminati, F; Cerello, P G; Saiz, P

    2003-01-01

    AliEn (ALICE Environment) is a GRID-like system for large scale job submission and distributed data management developed and used in the context of ALICE, the CERN LHC heavy-ion experiment. With the aim of exploiting upcoming Grid resources to run AliEn-managed jobs and store the produced data, the problem of AliEn-EDG interoperability was addressed and an in-terface was designed. One or more EDG (European Data Grid) User Interface machines run the AliEn software suite (Cluster Monitor, Storage Element and Computing Element), and act as interface nodes between the systems. An EDG Resource Broker is seen by the AliEn server as a single Computing Element, while the EDG storage is seen by AliEn as a single, large Storage Element; files produced in EDG sites are registered in both the EDG Replica Catalogue and in the AliEn Data Catalogue, thus ensuring accessibility from both worlds. In fact, both registrations are required: the AliEn one is used for the data management, the EDG one to guarantee the integrity and...

  8. Alien species on the coasts of Turkey

    Directory of Open Access Journals (Sweden)

    M.E. CINAR

    2012-12-01

    Full Text Available The compilation of data on alien species reported from the Turkish coasts yielded a total of 263 species belonging to 11 systematic groups, of which Mollusca had the highest number of species (85 species, followed by Crustacea (51, fishes (43 and phytobenthos (39. The Black Sea is represented by a total of 20 alien species, the Sea of Marmara by 48 species, the Aegean Sea by 98 species and the Levantine Sea by 202 species. The majority of aliens found in the Black Sea and the Sea of Marmara were transported via shipping, whereas the Levantine coast is extensively subjected to Lessepsian migration. Benthic habitats (soft and hard substrata comprise 76% of the total alien species and the pelagic environment is inhabited by thirty-nine species. Almost 50% of aliens collected from the Turkish coasts were found only at 0-10 m depth. Eight species occur at depths deeper than 100 m. The impacts of aliens on the benthic and pelagic ecosystems are presented.

  9. Alien seed beetles (Coleoptera: Chrysomelidae: Bruchinae) in Europe.

    Science.gov (United States)

    Yus-Ramos, Rafael; Ventura, Daniel; Bensusan, Keith; Coello-García, Pedro; György, Zoltán; Stojanova, Anelia

    2014-07-01

    Under the framework of the DAISIE consortium, whose main mission is to make an inventory of the alien invasive species of Europe and its islands, we review the current state of knowledge and provide an up-to-date catalogue and distributional status for alien seed beetles (Coleoptera: Chrysomelidae: Bruchinae) in Europe. This work is based on studies of the species detected from the last century to the present, but with greater emphasis on the beginning of the 21st century, during which new biological studies have been carried out and findings made in European countries. The main objective of this paper is to focus on this last fact, which has promoted new views on the existing and potential threat of exotic bruchids in relation to climate change. This must now be regarded as a matter of concern for European agricultural and environmental policies. Only species of exotic origin introduced in European regions outside their native range were considered. Therefore, species of European origin spreading to new countries within Europe are not treated. Also, we provide a new approach to classifying alien seed beetle species according to their ability to become established, distinguishing between the well-established and those that may appear in seed stores but are not capable of invading natural and agricultural ecosystems. We present a taxonomic characterization of the alien bruchids found in Europe, providing an illustrated key based on external morphological characters of adults. The key facilitates the identification of the sixteen most frequently recorded genera, which represent 37 of the 42 species of exotic species recorded in Europe up to the present, whether established, not established or occasional. Finally, we provide a summary of the state of knowledge of the taxonomy and biology of the 20 most worrying species as pests, both established and non-established. This includes, where appropriate, an illustrated key for the identification of species. The study

  10. Implementing invasive species management in an adaptive management framework

    Directory of Open Access Journals (Sweden)

    Llewellyn C. Foxcroft

    2011-05-01

    Full Text Available Adaptive management theory has attracted substantial interest in recent years, in natural resource management in general and also for invasive alien species management. However, whilst many theoretical and conceptual advances have been made, documented cases of practical applications are rare. Coupling invasive species management components with adaptive feedback processes is not without challenges, requiring a substantial change in the thinking and practice of all those involved. Drawing on a decade of experience in South African National Parks, we suggest an approach to implementing adaptive management for controlling invasive alien species. Whilst efforts have been made to advance components of the overall management strategy, the absence of a framework for decision making and feedback mechanisms, inflexibility in the system and shortcomings in the governance structure are all identified as barriers to learning and knowledge integration for the purposes of effective invasive alien species management. The framework provided here, encompassing documents, committees and processes, is aimed at addressing these shortcomings.Conservation implication: Adaptive management theory offers a robust tool for managing inherently complex systems. Its practical application, however, requires distilling the theory into useable functions. We offer a framework to advance implementation of strategic adaptive management for the control of invasive alien species using experiences gained from South African National Parks.

  11. 双滑块弯销内抽芯机构设计%Design of Double Sliders Forniciform Dowel Inside Core-pulling Structure

    Institute of Scientific and Technical Information of China (English)

    陈怀民

    2013-01-01

    在带有90°弯管的移位器底座注塑模具设计中,提出一种适用于弯管抽芯的双滑块弯销内抽芯机构。通过从弯管弯曲段主型芯中分割出滑块型芯先进行内抽芯,避免了脱模时带倒扣的弯管与主型芯发生摩擦。通过在滑块型芯的弯销内抽芯机构中引进辅助滑块,替代传统的注塑模具辅助分型面结构,可实现滑块型芯任意角度的内抽芯,从而简化了注塑模具的结构,提高了模具抽芯机构的工作稳定性。%In the injection mold design process of the shifter pedestal with 90° bending pipe,a double sliders forniciform dowel inside core-pulling mechanism suitable for the bending pipe core-pulling was put forward. Through separating slider core from main bending core of the bending pipe for doing inside core-pulling firstly,the interference of the main core and the bending pipe with undercut is avoided when demolding. Through adding auxiliary slider into the forniciform dowel inside core-pulling mechanism of the slider core for replacing traditional auxiliary parting surface of injection mold,the inside core-pulling at any angle of the slider core can be realized. The inside core-pulling mechanism can reduce the complexity of the mold structure and enhance the core-pulling work stability.

  12. Structural Design and Numerical Analysis of Segmented Hydrostatic Slider%拼块式液体静压导轨设计与数值分析

    Institute of Scientific and Technical Information of China (English)

    柯晓龙; 黄海滨; 林晓辉; 姜涛

    2014-01-01

    This paper presented a new segmented hydrostatic slider and built a corresponding verification model aiming at higher machining accuracy and better manufacturing technology. Based on the theory of fluid dynamic, parameter calculation of hydrostatic slider at different oil pocket areas was done, and using MATLAB for simulation, impact of parameters such as oil packet dimension, dynamic viscosity and equivalent diameter ratio on the hydrostatic slider was discussed. The results show that increase of equivalent diameter ratio (β) or dimension of oil packet ( b2 ) can improve the oil supply pressure of hydrostatic slider significantly. It can provide theoretical support to the design and application of hydrostatic sliders.%出于加工精度和制造工艺的考虑,采用一种新式的拼块式液体静压导轨结构搭建了相应的实物平台。根据液体静压支撑原理,完成不等面积对置静压支撑导轨的关键参数计算。利用Matlab软件,分析了油腔尺寸、动力粘度和节流比等参数对导轨供油压力等指标的影响。结果表明,适当增加节流比β和小油腔尺寸b2,可以提高导轨供油压力。该研究可为液体静压导轨的工程设计与应用提供理论借鉴。

  13. Socioeconomic and livelihood impact of invasive species on marginal homesteads: the case of aceria guerreronis on coconut palms in India

    OpenAIRE

    Aravindakshan, Sreejith

    2011-01-01

    Alien invasive species are non-native organisms that occur outside their natural adapted habitat and dispersal potential. They are seen as a threat not only to biodiversity and ecosystems, but also to socioeconomic development, livelihood and human well-being. In India, the bioinvasion of coconut palms by an alien invasive mite species Aceria guerreronis, popularly known as ‘Coconut mite’ accounting for enormous economic loss was first noticed just before the start of the new m...

  14. Parental Alienation Syndrome vs. Parental Alienation: Which Diagnosis Should Evaluators Use in Child-Custody Disputes?

    Science.gov (United States)

    Gardner, Richard A.

    2002-01-01

    The purpose of this article is to elucidate the sources of controversy between the use of the terms Parental Alienation Syndrome and Parental Alienation and to delineate the advantages and disadvantages of using either term in the context of child-custody disputes. It concludes that families are best served when the more specific term, Parental…

  15. Toxicity of glyphosate as Glypro and LI700 to red-eared slider (trachemys scripta elegans) embryos and early hatchlings.

    Science.gov (United States)

    Sparling, Donald W; Matson, Cole; Bickham, John; Doelling-Brown, Paige

    2006-10-01

    More than 8.2 billion ha of cropland, gardens, and forests are treated with the herbicide glyphosate each year. Whereas the toxicity of glyphosate and associated adjuvants has been measured in other vertebrates, few, if any, studies have looked at their effects in reptiles. In some instances, management of turtle habitat requires control of successional stages through application of herbicides. Adults and juvenile turtles may be exposed directly, whereas embryos may contact the chemicals through the soil. In the present study, we exposed eggs of red-eared sliders (Trachemys scripta elegans) to single applications of herbicide ranging from 0 to 11,206 ppm wet weight of glyphosate in Glypro and 0 to 678 ppm of the surfactant, LI700. Hatching success at the highest concentration was significantly lower (73%) than in other treatments (80-100%). At hatch, turtles at the highest concentration weighed less than those at other concentrations. During a 14-d holding period, we observed dose-response relationships in the ability of hatchlings to right themselves when turned on their backs. At the end of the holding period, hatchlings at the highest dose level were still lighter, and somatic indices were lower, than those in other treatments. Genetic damage, as measured by flow cytometry, increased with treatment concentration except for the highest dose. We conclude that because of the high concentrations needed to produce effects and the protection offered by several centimeters of soil or sediment, glyphosate with LI700 poses low levels of risk to red-eared slider embryos under normal field operations with regards to the endpoints measured in the present study. Carelessness in handling glyphosate or failure to follow label directions may produce adverse effects. There also is a risk that the health of turtle embryos may be affected in ways not measured in the present study.

  16. Investigating Invasives

    Science.gov (United States)

    Lightbody, Mary

    2008-01-01

    Invasive species, commonly known as "invasives," are nonnative plants, animals, and microbes that completely take over and change an established ecosystem. The consequences of invasives' spread are significant. In fact, many of the species that appear on the Endangered Species list are threatened by invasives. Therefore, the topic of invasive…

  17. Spatial distribution and temporal trends of soft-bottom marine benthic alien species collected during the period 1989-2008 in the Nervión estuary (southeastern Bay of Biscay)

    Science.gov (United States)

    Zorita, Izaskun; Solaun, Oihana; Borja, Angel; Franco, Javier; Muxika, Iñigo; Pascual, Marta

    2013-10-01

    As the introduction of alien species represents one of the most important causes of biodiversity loss, it is crucial to study the distribution of alien species in order to control or eradicate their introduction and spread. Thus, the present study aimed to analyse the spatial distribution and temporal trends of soft-bottom marine benthic alien species collected during 20 years in the Nervión estuary, southeastern Bay of Biscay. Results indicated that, from a total of 6688 species records, 117 corresponded to alien species. Likewise, from a total of 742 different species identified, 23 species were classified as alien species. The two most frequently recorded alien species, Pseudopolydora paucibranchiata and Monocorophium acherusicum, appeared mainly at the intermediate part of the estuary that suffered historically an intense pollution. The presence and abundance of soft-bottom alien species became more evident since the mid-nineties, when the widening of the Bilbao Harbour occurred, together with a water quality improvement and the industry decline. Finally, although the identified alien species are considered as not invasive, the spread of alien species in the estuary might be considered as a threat.

  18. Alien Roadside Species More Easily Invade Alpine than Lowland Plant Communities in a Subarctic Mountain Ecosystem

    Science.gov (United States)

    Lembrechts, Jonas J.; Milbau, Ann; Nijs, Ivan

    2014-01-01

    Effects of roads on plant communities are not well known in cold-climate mountain ecosystems, where road building and development are expected to increase in future decades. Knowledge of the sensitivity of mountain plant communities to disturbance by roads is however important for future conservation purposes. We investigate the effects of roads on species richness and composition, including the plant strategies that are most affected, along three elevational gradients in a subarctic mountain ecosystem. We also examine whether mountain roads promote the introduction and invasion of alien plant species from the lowlands to the alpine zone. Observations of plant community composition were made together with abiotic, biotic and anthropogenic factors in 60 T-shaped transects. Alpine plant communities reacted differently to road disturbances than their lowland counterparts. On high elevations, the roadside species composition was more similar to that of the local natural communities. Less competitive and ruderal species were present at high compared with lower elevation roadsides. While the effects of roads thus seem to be mitigated in the alpine environment for plant species in general, mountain plant communities are more invasible than lowland communities. More precisely, relatively more alien species present in the roadside were found to invade into the surrounding natural community at high compared to low elevations. We conclude that effects of roads and introduction of alien species in lowlands cannot simply be extrapolated to the alpine and subarctic environment. PMID:24586947

  19. Do abundance and proximity of the alien Impatiens glandulifera affect pollination and reproductive success of two sympatric co-flowering native species?

    Directory of Open Access Journals (Sweden)

    Anne-Laure Jacquemart

    2012-12-01

    Full Text Available In invasion ecology, potential impacts of aliens on native flora are still under debate. Our aim was to determine the pollinator mediated effects of both proximity and abundance of an alien species on the reproductive success of natives. We chose the highly invasive Impatiens glandulifera and two native species: Epilobium angustifolium and Aconitum napellus ssp. lusitanicum. These species share characteristics allowing for pollination interactions: similar biotopes, overlapping flowering periods and same main pollinators. The effects of abundance (5, 25 and 100 individuals and proximity (0 and 15 m of the alien on visitation rate, insect behaviour, pollen deposition and reproductive success of both natives were investigated during 2 flowering seasons. We used centred visitation rates as they can be directly interpreted as a positive or negative effect of the invasive.Both abundance and proximity of the alien increased bumblebee visitation rates to both natives. On the other hand, abundance of the exotic species had a slight negative effect on honeybee visits to natives while its proximity had no effect. The behaviour of bumblebees changed as visitors left significantly more often the native plants for I. glandulifera when its abundance increased. As a consequence of this “inconstancy”, bees deposited considerable quantities of alien pollen on native stigmas. Nevertheless, this interspecific pollen transfer did not decrease seed set in natives. Self-compatibility and high attractiveness of both native species probably alleviate the risk of altered pollinator services and reproductive success due to the invader in natural populations.

  20. Intraguild predation behaviour of ladybirds in semi-field experiments explains invasion success of Harmonia axyridis

    NARCIS (Netherlands)

    Raak-van den Berg, C.L.; Lange, de H.J.; Lenteren, van J.C.

    2012-01-01

    Harmonia axyridis has been introduced as a biological control agent in Europe and the USA. Since its introduction, it has established and spread, and it is now regarded as an invasive alien species. It has been suggested that intraguild predation is especially important for the invasion success of H

  1. Using effect size benchmarks to assess when alien impacts are actually alien.

    Science.gov (United States)

    Smith, Helen M; Dickman, Chris R; Banks, Peter B

    2017-01-27

    Alien predators have on average twice the impact on native prey populations than do native predators, and are a severe threat to wildlife globally. Manipulation experiments can be used to quantify the impact of an alien predator on its prey population/s, but unless the results are compared to benchmarks, it is unclear whether this impact is indeed greater than that of a native predator. Here we use the Australian garden skink Lampropholis delicata and alien black rat Rattus rattus to test if black rats are an additive source of predation for the skink, and to judge whether the effect size of rat-impact on the skink represents that of an alien or native predator. We used replicated experiments to exclude black rats at local and landscape scales to test how rats affect skink activity and trapping frequency. Both manipulations had positive effects on skinks, however, the population-level effect size was lower than that described for alien predators but similar to that expected for native predators. We suggest that Australian skinks may respond appropriately to predatory alien rats because they coevolved with endemic Rattus species. This adds novel insights into the varying levels of impact that alien predators have on native prey.

  2. Using effect size benchmarks to assess when alien impacts are actually alien

    Science.gov (United States)

    Smith, Helen M.; Dickman, Chris R.; Banks, Peter B.

    2017-01-01

    Alien predators have on average twice the impact on native prey populations than do native predators, and are a severe threat to wildlife globally. Manipulation experiments can be used to quantify the impact of an alien predator on its prey population/s, but unless the results are compared to benchmarks, it is unclear whether this impact is indeed greater than that of a native predator. Here we use the Australian garden skink Lampropholis delicata and alien black rat Rattus rattus to test if black rats are an additive source of predation for the skink, and to judge whether the effect size of rat-impact on the skink represents that of an alien or native predator. We used replicated experiments to exclude black rats at local and landscape scales to test how rats affect skink activity and trapping frequency. Both manipulations had positive effects on skinks, however, the population-level effect size was lower than that described for alien predators but similar to that expected for native predators. We suggest that Australian skinks may respond appropriately to predatory alien rats because they coevolved with endemic Rattus species. This adds novel insights into the varying levels of impact that alien predators have on native prey. PMID:28128305

  3. Updated review of marine alien species and other ‘newcomers’ recorded from the Maltese Islands (Central Mediterranean

    Directory of Open Access Journals (Sweden)

    J. EVANS

    2015-01-01

    Full Text Available An updated review of marine alien species and other ‘newcomers’ recorded from the Maltese Islands is presented on account of new records and amendments to a previous review in 2007. Species were classified according to their establishment status (‘Questionable’, ‘Casual’, ‘Established’, ‘Invasive’ and origin (‘Alien’, ‘Range expansion’, ‘Cryptogenic’. A total of 31 species were added to the inventory, while 6 species have been removed, bringing the total number of species to 73. Of these, 66 are considered to be aliens (or putative aliens but with uncertain origin with the remaining 7 resulting from range expansion. Six records are considered to be questionable and hence unverified. For verified records, the dominant taxonomic groups are Mollusca (represented by 21 species and Actinopterygii (15 species, followed by Crustacea (8 species and Rhodophyta (7 species. Eight of these species (aliens: Caulerpa cylindracea, Lophocladia lallemandi, Womersleyella setacea, Brachidontes pharaonis, Percnon gibbesi, Fistularia commersonii, Siganus luridus; range extender: Sphoeroides pachygaster are considered to be invasive. The introduction pathway for 30 species is unknown. Amongst the alien species, ‘Shipping’ is the most common introduction pathway, followed by ‘Secondary dispersal’ from elsewhere in the Mediterranean Sea. An increasing trend in the number of alien marine species reported from the Maltese Islands is evident, with a peak of 22 species recorded during the last decade (2001–2010. A discussion on the rationale for including range-expanding species in national inventories of recent arrivals, and in the analysis of trends in records from the Maltese Islands, is included. In particular, the general warming trend of Mediterranean surface waters appears to be facilitating the westward spread of thermophilic alien species from the Eastern to the Central Mediterranean, and the eastward range expansion of

  4. An introduction to parental alienation syndrome.

    Science.gov (United States)

    Farkas, Michelle M

    2011-04-01

    Parental alienation syndrome (PAS) can occur during a tumultuous divorce between embattled parents involved in a bitter child custody dispute. During parental warfare, a child is used as a weapon by one parent (alienating parent) against the other parent (alienated/targeted parent). The targeted parent-child relationship once encased with unconditional love is transformed by an unrelenting campaign of denigration, criticism, and hatred. Since nursing literature on PAS is almost nonexistent, the purpose of this article is to increase nursing awareness and provide basic information. Awareness of PAS symptoms and interpersonal dynamics is important to prompt nurses in recommending treatment for families. Nurses should collaboratively join other professionals in their quest to provide the best treatment possible.

  5. Transient alien limb phenomenon in right frontoparietal infarction

    Directory of Open Access Journals (Sweden)

    Panda Samhita

    2010-01-01

    Full Text Available Alien limb phenomenon is associated with different neurological disorders, such as stroke and corticobasal degeneration. It is usually caused by involvement of the corpus callosum, with or without the frontal regions. Rarely, it can result from insult in the posterior cerebral artery territory. Alien limb phenomenon is generally persistent. Here, an unusual case of transient alien hand phenomenon is reported.

  6. 26 CFR 301.7701(b)-1 - Resident alien.

    Science.gov (United States)

    2010-04-01

    ... 26 Internal Revenue 18 2010-04-01 2010-04-01 false Resident alien. 301.7701(b)-1 Section 301.7701... ADMINISTRATION PROCEDURE AND ADMINISTRATION Definitions § 301.7701(b)-1 Resident alien. (a) Scope. Section 301.7701(b)-1(b) provides rules for determining whether an alien individual is a lawful permanent...

  7. 45 CFR 233.51 - Eligibility of sponsored aliens.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 2 2010-10-01 2010-10-01 false Eligibility of sponsored aliens. 233.51 Section... CONDITIONS OF ELIGIBILITY IN FINANCIAL ASSISTANCE PROGRAMS § 233.51 Eligibility of sponsored aliens... affidavit(s) of support or similar agreement on behalf of an alien (who is not the child of the sponsor...

  8. 20 CFR 404.1036 - Certain nonresident aliens.

    Science.gov (United States)

    2010-04-01

    ... 20 Employees' Benefits 2 2010-04-01 2010-04-01 false Certain nonresident aliens. 404.1036 Section... Employment § 404.1036 Certain nonresident aliens. (a) Foreign students. (1) Foreign students (nonimmigrant aliens) may be temporarily in the United States under subparagraph (F) of section 101(a)(15) of...

  9. Gulliver’s Alienation from A Total Rationalist

    Institute of Scientific and Technical Information of China (English)

    周月

    2015-01-01

    Taken the historical background of this novel into consideration, the present essay presents a text-based analysis of Gulliver's alienation. It analyzes the process of Gulliver's alienation from a total rationalist to an anti-rationalist. Gulliver's alienation shows Swift's his deep reflection on the 18th Century total rationalism.

  10. 42 CFR 435.139 - Coverage for certain aliens.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 4 2010-10-01 2010-10-01 false Coverage for certain aliens. 435.139 Section 435... Aliens § 435.139 Coverage for certain aliens. The agency must provide services necessary for the treatment of an emergency medical condition, as defined in § 440.255(c) of this chapter, to those...

  11. 32 CFR 1630.46 - Class 4-T: Treaty alien.

    Science.gov (United States)

    2010-07-01

    ... 32 National Defense 6 2010-07-01 2010-07-01 false Class 4-T: Treaty alien. 1630.46 Section 1630.46 National Defense Other Regulations Relating to National Defense SELECTIVE SERVICE SYSTEM CLASSIFICATION RULES § 1630.46 Class 4-T: Treaty alien. In Class 4-T shall be placed any registrant who is an alien...

  12. 22 CFR 40.9 - Classes of inadmissible aliens.

    Science.gov (United States)

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Classes of inadmissible aliens. 40.9 Section 40.9 Foreign Relations DEPARTMENT OF STATE VISAS REGULATIONS PERTAINING TO BOTH NONIMMIGRANTS AND... inadmissible aliens. Subparts B through L describe classes of inadmissible aliens who are ineligible to...

  13. 78 FR 51696 - Restrictions on Legal Assistance to Aliens

    Science.gov (United States)

    2013-08-21

    ... 45 CFR Part 1626 Restrictions on Legal Assistance to Aliens AGENCY: Legal Services Corporation... Legal Services Corporation (LSC or Corporation) regulation on legal assistance to aliens. The revisions are intended to implement three statutory changes on aliens eligible for legal assistance from...

  14. 42 CFR 436.330 - Coverage for certain aliens.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 4 2010-10-01 2010-10-01 false Coverage for certain aliens. 436.330 Section 436... Coverage of the Medically Needy § 436.330 Coverage for certain aliens. If an agency provides Medicaid to... condition, as defined in § 440.255(c) of this chapter to those aliens described in § 436.406(c) of...

  15. 42 CFR 436.128 - Coverage for certain qualified aliens.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 4 2010-10-01 2010-10-01 false Coverage for certain qualified aliens. 436.128... Mandatory Coverage of the Categorically Needy § 436.128 Coverage for certain qualified aliens. The agency... § 440.255(c) of this chapter to those aliens described in § 436.406(c) of this subpart....

  16. 8 CFR 1235.3 - Inadmissible aliens and expedited removal.

    Science.gov (United States)

    2010-01-01

    ... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Inadmissible aliens and expedited removal. 1235.3 Section 1235.3 Aliens and Nationality EXECUTIVE OFFICE FOR IMMIGRATION REVIEW, DEPARTMENT OF JUSTICE IMMIGRATION REGULATIONS INSPECTION OF PERSONS APPLYING FOR ADMISSION § 1235.3 Inadmissible...

  17. 43 CFR 426.8 - Nonresident aliens and foreign entities.

    Science.gov (United States)

    2010-10-01

    ... 43 Public Lands: Interior 1 2010-10-01 2010-10-01 false Nonresident aliens and foreign entities..., DEPARTMENT OF THE INTERIOR ACREAGE LIMITATION RULES AND REGULATIONS § 426.8 Nonresident aliens and foreign... reclamation law or these regulations, a nonresident alien or foreign entity that directly holds land in...

  18. 22 CFR 41.24 - International organization aliens.

    Science.gov (United States)

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false International organization aliens. 41.24... aliens. (a) Definition of international organization. “International organization” means: (1) Any public...)(27)(I), INTELSAT or any successor or separated entity thereof. (b) Aliens coming to...

  19. 22 CFR 41.58 - Aliens in religious occupations.

    Science.gov (United States)

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Aliens in religious occupations. 41.58 Section... IMMIGRATION AND NATIONALITY ACT, AS AMENDED Business and Media Visas § 41.58 Aliens in religious occupations. (a) Requirements for “R” classification. An alien shall be classifiable under the provisions of...

  20. 32 CFR 1602.3 - Aliens and nationals.

    Science.gov (United States)

    2010-07-01

    ... 32 National Defense 6 2010-07-01 2010-07-01 false Aliens and nationals. 1602.3 Section 1602.3 National Defense Other Regulations Relating to National Defense SELECTIVE SERVICE SYSTEM DEFINITIONS § 1602.3 Aliens and nationals. (a) The term alien means any person who is not a citizen or national of...

  1. 22 CFR 41.55 - Aliens with extraordinary ability.

    Science.gov (United States)

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Aliens with extraordinary ability. 41.55... IMMIGRATION AND NATIONALITY ACT, AS AMENDED Business and Media Visas § 41.55 Aliens with extraordinary ability. (a) Requirements for O classification. An alien shall be classifiable under the provisions of INA...

  2. The Lost Parents' Perspective on Parental Alienation Syndrome.

    Science.gov (United States)

    Vassiliou, Despina; Cartwright, Glenn F.

    2001-01-01

    Examined alienated fathers' and mothers' perceptions of parental alienation syndrome (PAS). Data were collected via semistructured, open ended interview questionnaires to determine if there were shared characteristics among alienated families; common issues in marital conflicts contributing to marriage dissolution; similarities in experience of…

  3. AliEn - EDG Interoperability in ALICE

    OpenAIRE

    Bagnasco, S.; Barbera, R; Buncic, P.; Carminati, F.; Cerello, P.; Saiz, P.

    2003-01-01

    AliEn (ALICE Environment) is a GRID-like system for large scale job submission and distributed data management developed and used in the context of ALICE, the CERN LHC heavy-ion experiment. With the aim of exploiting upcoming Grid resources to run AliEn-managed jobs and store the produced data, the problem of AliEn-EDG interoperability was addressed and an in-terface was designed. One or more EDG (European Data Grid) User Interface machines run the AliEn software suite (Cluster Monitor, Stora...

  4. Alienation in As I lay Dying

    Institute of Scientific and Technical Information of China (English)

    汪倩

    2013-01-01

    The enormous change of the earlier 20th century has not only brought false prosperity to the society but also pushed people into spiritual wasteland. Indifference and alienation have replaced communication and trust among people or between one and self. By analyzing the alienation among people, the self-split of oneself and the reasons resulting these in William Faulkner ’s As I lay Dying, the concern of Faulkner about the social phenomenon and his pursuit of transcending the personal to a universal level will be better presented to us.

  5. Does residence time affect responses of alien species richness to environmental and spatial processes?

    Directory of Open Access Journals (Sweden)

    Matteo Dainese

    2012-08-01

    Full Text Available One of the most robust emerging generalisations in invasion biology is that the probability of invasion increases with the time since introduction (residence time. We analysed the spatial distribution of alien vascular plant species in a region of north-eastern Italy to understand the influence of residence time on patterns of alien species richness. Neophytes were grouped according to three periods of arrival in the study region (1500–1800, 1800–1900, and > 1900. We applied multiple regression (spatial and non-spatial with hierarchical partitioning to determine the influence of climate and human pressure on species richness within the groups. We also applied variation partitioning to evaluate the relative importance of environmental and spatial processes. Temperature mainly influenced groups with speciesa longer residence time, while human pressure influenced the more recently introduced species, although its influence remained significant in all groups. Partial regression analyses showed that most of the variation explained by the models is attributable to spatially structured environmental variation, while environment and space had small independent effects. However, effects independent of environment decreased, and spatially independent effects increased, from older to the more recent neophytes. Our data illustrate that the distribution of alien species richness for species that arrived recently is related to propagule pressure, availability of novel niches created by human activity, and neutral-based (dispersal limitation processes, while climate filtering plays a key role in the distribution of species that arrived earlier. This study highlights the importance of residence time, spatial structure, and environmental conditions in the patterns of alien species richness and for a better understanding of its geographical variation.

  6. Native and alien ichthyofauna in coastal fishery of Rhodes (eastern Mediterranean (2002-2010

    Directory of Open Access Journals (Sweden)

    Maria Corsini-Foka

    2015-11-01

    Full Text Available Rhodes Island (southeastern Aegean is located in a geographically crucial region subjected to biological invasions. Among the 108 alien species recorded, 30 are fish, all of Indo-Pacific/Red Sea origin introduced via Suez through Lessepsian migration (Corsini-Foka et al., 2015; Corsini-Foka and Kondylatos, In press; Kondylatos and Corsini-Foka, In press. In this oligotrophic area, fishery production is limited, due to the paucity of species of commercial interest and their low abundance, while adapted infrastructures for fish landing and marketing are absent. Coastal fishery has dominated during the last twenty years (ELSTAT, 2015. Within 2002-2010, the Hydrobiological Station of Rhodes conducted experimental boat seining surveys, using exclusively a professional 12m fishing boat, at 5-30 m depth, in the Gulf of Trianda (sandy mud, Posidonia meadows. The 94 carried out hauls (7-18 hauls/year, produced a total fish biomass of approximately 4400 Kg, recording 97 fish (86 native, 11 alien and 4 cephalopod species (3 native, 1 alien. Fish species ranged from 32 to 63/year, whereas aliens ranged from 5 to 8 species. Almost steadily present since 2002, were earlier colonizers such as Apogonichthyoides pharaonis, Siganus rivulatus, Siganus luridus, Stephanolepis diaspros and more recent ones as Pteragogus trispilus, Sphyraena chrysotaenia and Fistularia commersonii, while Lagocephalus sceleratus, firstly recorded in 2005, occurred regularly since 2007; the presence of Lagocephalus suezensis, Sphyraena flavicauda and Upeneus pori was scattered since their first records in 2004-2005. Alien fish commercially important are the Siganids, S. chrysotaenia and surprisingly F. commersonii. In terms of biomass per haul, alien fish ranged from 0 to 18.5 Kg, native from 1.5 to 182 Kg. Catches were dominated by Centracanthidae (Spicara spp. and Sparidae (Boops boops, sometimes by other native such as Oblada melanura, Diplodus spp., Chromis Chromis and others. The

  7. Pharmacokinetics of meloxicam in red-eared slider turtles (Trachemys scripta elegans) after single intravenous and intramuscular injections.

    Science.gov (United States)

    Uney, Kamil; Altan, Feray; Aboubakr, Mohammed; Cetin, Gul; Dik, Burak

    2016-05-01

    OBJECTIVE To determine the pharmacokinetics of meloxicam after single IV and IM injections in red-eared slider turtles (Trachemys scripta elegans). ANIMALS 8 healthy red-eared slider turtles. PROCEDURES Turtles received 1 dose of meloxicam (0.2 mg/kg) IV or IM (4 turtles/route), a 30-day washout period was provided, and then turtles received the same dose by the opposite route. Blood samples were collected at predetermined times for measurement of plasma meloxicam concentration. Pharmacokinetic values for each administration route were determined with a 2-compartment open model approach. RESULTS For IV administration, mean ± SD values of major pharmacokinetic variables were 1.02 ± 0.41 hours for distribution half-life, 9.78 ± 2.23 hours for elimination half-life, 215 ± 32 mL/kg for volume of distribution at steady state, 11.27 ± 1.44 μg•h/mL for area under the plasma concentration versus time curve, and 18.00 ± 2.32 mL/h/kg for total body clearance. For IM administration, mean values were 0.35 ± 0.06 hours for absorption half-life, 0.72 ± 0.06 μg/mL for peak plasma concentration, 1.5 ± 0.0 hours for time to peak concentration, 3.73 ± 2.41 hours for distribution half-life, 13.53 ± 1.95 hours for elimination half-life, 11.33 ± 0.92 μg•h/mL for area under the plasma concentration versus time curve, and 101 ± 6% for bioavailability. No adverse reactions were detected. CONCLUSIONS AND CLINICAL RELEVANCE Long half-life, high bioavailability, and lack of immediate adverse reactions of meloxicam administered IM at 0.2 mg/kg suggested the possibility of safe and effective clinical use in turtles. Additional studies are needed to establish appropriate administration frequency and clinical efficacy.

  8. Diversity of invasive species in Shanghai

    Directory of Open Access Journals (Sweden)

    Qingrou Zhang

    2013-11-01

    Full Text Available A list of invasive alien species (IAS is essential for initiating an analysis of the biological and ecological traits of such species and for improving our understanding of patterns of biological invasions. An inventory of IAS in Shanghai was prepared through a literature survey. A total of 212 IAS belonging to 63 orders and 87 families were recorded. Of these, 65% were plants, 29% were animals, and the rest were microorganisms. Dominant groups could be distinguished in both plant and animal groups. Species originating from the Americas made up 51% of the total, while 52% of plant species were introduced intentionally and 82% of animal species unintentionally. Of the invasive plants, 93% are distributed in highly disturbed habitats with rich resources, whereas 76% of invasive animals occur in storehouses and farmlands. The present information on diversity and ecological features of IAS is crucial for designing management strategies against the negative impacts of such species in Shanghai.

  9. Invite an Alien to Astronomy Night

    Science.gov (United States)

    Governor, Donna; Richwine, Pebble

    2007-01-01

    Dozens of inflatable aliens recently "descended" upon the authors' middle school to kick-off their first school-wide Astronomy night. With an estimated attendance of over 500, their eighth-grade students hosted over a dozen activity-rich sessions designed to entertain and educate students and their families about the wonders of the solar system…

  10. God-Belief, Self- Detection, Alienation

    Directory of Open Access Journals (Sweden)

    Majid Sadeghi Hasan Abadi

    2010-04-01

    Full Text Available According to some Western thinkers, considering earthy and compelled human alongside with the heavenly and compelling God can result in nothing but human’s alienation and transduction of alien personality in his mind and spirit. Basically, man’s realization of alienation and its type has a close relationship with the way of consideration of human and his nature. Of course type of human regard to God and kind of God that a religion defines, is another altered factor that into the side transaction, human and God has a decisive role. In Islamic teaching human nature and religion are defined as two truth corresponding together and in other words unique truth manifest into the sight of genesis and legislation as human nature and religion. In Islamic philosophy especially Hekmah Al-Motaaliyeh (transcendental wisdom human’s relationship with God and also universe with God, is the same as relation and dependency. In heavenly instructions, human nature is divine whiff. Therefore, it should have total congruity with divine nature. Since self- forgetfulness is the direct result of God- forgetfulness, God-belief and self- detection have strong relation with each other, too. Moreover, in the mystical instructions of the Muslims mystics, God is a truth that is closer to man than himself. And therefore, the more he is such proximity , attraction and rapture to God, not only the man becomes self- alien , but also he will recognize himself better than before and will approach to his own origin.

  11. Telematics, Demography, and the End of Alienation.

    Science.gov (United States)

    Coates, Joseph F.

    1982-01-01

    The social and organizational consequences of the rapid spread of telecommunications and computer technology promise a social revolution that could substantially reduce alienation in the work force. Educational attainment, scheduling, and other factors related to technological advancement can affect work satisfaction and opportunities. (MSE)

  12. Staff Exchange or Legal Alien Programs

    DEFF Research Database (Denmark)

    Jørgensen, Rune Nørgaard

    2016-01-01

    SRA would very much like to support the exchange of best practice between members throughout the year and the Membership Committee is presently looking into the opportunities for a Staff Exchange or Legal Alien Program. However the International Section has already had the chance to provide...

  13. Alien wavelength modeling tool and field trial

    DEFF Research Database (Denmark)

    Sambo, N.; Sgambelluri, A.; Secondini, M.

    2015-01-01

    A modeling tool is presented for pre-FEC BER estimation of PM-QPSK alien wavelength signals. A field trial is demonstrated and used as validation of the tool's correctness. A very close correspondence between the performance of the field trial and the one predicted by the modeling tool has been...

  14. Processes of Alienation: Marx, Orff and Kodaly

    Science.gov (United States)

    Benedict, Cathy

    2009-01-01

    Using Marx as a lens through which to interrogate music methodology, in particular those espoused by Orff and Kodaly, this article suggests that rather than the free play and creativity Orff and Kodaly intended, the implementation of these methods in a strict and unmindful manner, often alienates both teacher and student from musicking. Thus these…

  15. Aliens Among Us : Are They Already Here ?

    Science.gov (United States)

    McGaha, J.

    2008-03-01

    Popular culture, science fiction and mainstream belief, says they are! What is the evidence? Astronomer, skeptic and retired USAF pilot James McGaha examines this "Space Age" Mythology. From years of investigation of the physical evidence of aliens and there spacecraft (UFO's) here on earth, McGaha presents the scientific facts.

  16. A Randomised, Placebo-Controlled Trial of Neurodynamic Sliders on Hamstring Responses in Footballers with Hamstring Tightness

    Science.gov (United States)

    Areeudomwong, Pattanasin; Oatyimprai, Ketsarakon; Pathumb, Saranchana

    2016-01-01

    Background Neurodynamics intervention is known to increase apparent muscle extensibility, but information regarding hamstring responses after a neurodynamic sliders (NS) technique is scarce. The aim of this study was to evaluate the effects of NS on apparent hamstring extensibility and activity in footballers with hamstring tightness. Methods Forty eligible healthy male footballers with hamstring tightness were each randomly allocated to either a 4-week NS technique or a control group (CG) receiving placebo shortwave intervention. Knee extension angles were measured with the passive knee extension test, and maximal voluntary isometric contraction (MVIC) of hamstrings was measured by a surface electromyography at baseline and after intervention sessions. Results The results showed that NS produced a statistically and clinically significant increase in knee extension angle compared to CG (P < 0.001); however, there was no difference between the groups receiving MVIC of hamstrings. Within group comparison, NS also provided a significant increase in knee extension angle (P < 0.001), whereas the control group did not. There was no change in hamstring MVIC in either group after intervention. Conclusions The findings of this study reveal that four weeks of NS technique improved apparent hamstring extensibility but did not change the hamstring activity in footballers with hamstring tightness. PMID:28090180

  17. Rigid-flexible outer sheath model using slider linkage locking mechanism and air pressure for endoscopic surgery.

    Science.gov (United States)

    Yagi, Akihiko; Matsumiya, Kiyoshi; Masamune, Ken; Liao, Hongen; Dohi, Takeyoshi

    2006-01-01

    The objective of this paper is to develop an outer sheath for flexible endoscopic manipulators. This sheath can switch two states including flexible and rigid, and make a rigid curved path for inserting manipulators. The flexible mode can be curved into a required shape. The rigid mode can hold the shape of the sheath, and then keep the path for instruments. Through the managed path, the flexible manipulators become easy to reach the target. We proposed a serial multi joint model to realize the flexible mechanism. This model is composed of a set of frame units which are connected serially. Each unit can be rotated to a given angle around the center of the joint. We developed a slider-link mechanism and a gear stopper controlled by air pressure for rigid mode. We designed and fabricated the prototype with a diameter of 16 mm and length of 290 mm. The experiment showed that the device could be switched from the flexible mode to the rigid mode when the air pressure was over 150 kPa, and each joint could hold its angle against the maximum 400 mNm. The phantom experiment showed that the flexible devices are possible to transmit the wire tension to the endpoint of the manipulator without changing the curving shape with by the developed outer sheath device.

  18. Do 'sliders' slide and 'tensioners' tension? An analysis of neurodynamic techniques and considerations regarding their application.

    Science.gov (United States)

    Coppieters, Michel W; Butler, David S

    2008-06-01

    Despite the high prevalence of carpal tunnel syndrome and cubital tunnel syndrome, the quality of clinical practice guidelines is poor and non-invasive treatment modalities are often poorly documented. The aim of this cadaveric biomechanical study was to measure longitudinal excursion and strain in the median and ulnar nerve at the wrist and proximal to the elbow during different types of nerve gliding exercises. The results confirmed the clinical assumption that 'sliding techniques' result in a substantially larger excursion of the nerve than 'tensioning techniques' (e.g., median nerve at the wrist: 12.6 versus 6.1mm, ulnar nerve at the elbow: 8.3 versus 3.8mm), and that this larger excursion is associated with a much smaller change in strain (e.g., median nerve at the wrist: 0.8% (sliding) versus 6.8% (tensioning)). The findings demonstrate that different types of nerve gliding exercises have largely different mechanical effects on the peripheral nervous system. Hence different types of techniques should not be regarded as part of a homogenous group of exercises as they may influence neuropathological processes differently. The findings of this study and a discussion of possible beneficial effects of nerve gliding exercises on neuropathological processes may assist the clinician in selecting more appropriate nerve gliding exercises in the conservative and post-operative management of common neuropathies.

  19. Identifying factors linked to the occurrence of alien gastropods in isolated woodland water bodies.

    Science.gov (United States)

    Spyra, Aneta; Strzelec, Małgorzata

    2014-03-01

    Biological invasions are a significant component of human-caused global change and is widely regarded as one of the main threats to natural biodiversity. Isolated anthropogenic water bodies created in the areas that are deprived of natural freshwater habitats allow the survival and reproduction of alien species on newly settled sites. They are often small with water level fluctuations causing frequent environmental disturbances. The colonisation success may be the result of the rate of their degradation. The aims of the study were to determine the environmental conditions that affect the existence of alien species of gastropods in this type of aquatic environment and to examine whether the occurrence of non-native species affects the community structure of the native species. This study made it possible to group woodland ponds according to the occurrence of the three invasive species in snail communities and discuss the environmental conditions present in these pond types. Analysis of water properties emphasised the distinctiveness of the selected pond types. In ponds of the Potamopyrgus antipodarum type, we found the highest values of some parameters mainly hardness, conductivity, and content of calcium and chlorides, in contrast with the Physella acuta type, which were characterised by the lowest values except for phosphates and nitrites. In the Ferrissia fragilis type, we found the highest nitrate content. Data on the occurrence of alien species in different water environments play an important role in actions which are taken to prevent new invasions and spread of non-native species as well as to reduce future impacts of invaders.

  20. A critical review of records of alien marine species from the Maltese Islands and surrounding waters (Central Mediterranean

    Directory of Open Access Journals (Sweden)

    M. SCIBERRAS

    2012-12-01

    Full Text Available An updated list of alien marine species recorded from the Maltese Islands and surrounding waters, compiled from scientific and ‘grey’ literature and from authenticated unpublished reports to the authors, is presented. The listed species are classified in one of four categories as regards establishment status: established, casual, invasive and questionable. Doubtful records are listed as ‘?’. A total of 48 species, including nine dubious ones, are included in the list. Of the accepted records, 64% are established, of which 15.4% are invasive, 18% are casual and 18% are questionable. The most represented groups are molluscs (14 species, fish (13 species and macrophytes (10 species. Six species are classified as invasive in Maltese waters: Lophocladia lallemandii, Womersleyella setacea, Caulerpa racemosa var. cylindracea, Percnon gibbesi, Fistularia commersonii and Sphoeroides pachygaster; impacts of some of these species on local ecosystems are discussed. Since the early 1900s, there has been an increasing trend in the number of alien marine species reported from the Maltese Islands. Transportation via shipping and in connection with aquaculture, as well as the range expansion of Lessepsian immigrants, appear to be the most common vectors for entry, accounting for 20%, 11% and 32% respectively of the alien species included in this review. The general warming trend of Mediterranean waters and increasing marine traffic may be facilitating the spread of warm-water Atlantic and Indo-Pacific species to the central Mediterranean, including the Maltese Islands.

  1. Spatial risk assessment of alien plants in China using biodiversity resistance theory

    Directory of Open Access Journals (Sweden)

    YouHua Chen

    2014-06-01

    Full Text Available In the present study, the potential occurrence risk of invasive plants across different provinces of China is studied using disease risk mapping techniques (empirical Bayesian smoothing and Poisson-Gamma model. The biodiversity resistance theory which predicts that high-biodiversity areas will have reduced risk of species invasion serves as the base for performing spatial risk assessment of plant invasion across provinces. The results show that, both risk mapping methods identified that north-eastern part of China have the highest relative risk of plant invasion. In contrast, south-western and south-eastern parts of China, which have high woody plant richness, are predicted to possess low relative risks of plant invasion. Through spatial regression analysis (simultaneous autoregression model, nine environmental variables representing energy availability, water availability, seasonality, and habitat heterogeneity are used to explain the relative risk of plant invasion across provinces of China. The fitting results suggest that, PRECrange and TEMrange are the most two important covariates correlated with the occurrence risks of alien plants at provincial level in China. As indicated by Moran's I index, spatial regression analysis can effectively eliminate the potential biases caused by spatial autocorrelation.

  2. The Global Distribution and Drivers of Alien Bird Species Richness.

    Science.gov (United States)

    Dyer, Ellie E; Cassey, Phillip; Redding, David W; Collen, Ben; Franks, Victoria; Gaston, Kevin J; Jones, Kate E; Kark, Salit; Orme, C David L; Blackburn, Tim M

    2017-01-01

    Alien species are a major component of human-induced environmental change. Variation in the numbers of alien species found in different areas is likely to depend on a combination of anthropogenic and environmental factors, with anthropogenic factors affecting the number of species introduced to new locations, and when, and environmental factors influencing how many species are able to persist there. However, global spatial and temporal variation in the drivers of alien introduction and species richness remain poorly understood. Here, we analyse an extensive new database of alien birds to explore what determines the global distribution of alien species richness for an entire taxonomic class. We demonstrate that the locations of origin and introduction of alien birds, and their identities, were initially driven largely by European (mainly British) colonialism. However, recent introductions are a wider phenomenon, involving more species and countries, and driven in part by increasing economic activity. We find that, globally, alien bird species richness is currently highest at midlatitudes and is strongly determined by anthropogenic effects, most notably the number of species introduced (i.e., "colonisation pressure"). Nevertheless, environmental drivers are also important, with native and alien species richness being strongly and consistently positively associated. Our results demonstrate that colonisation pressure is key to understanding alien species richness, show that areas of high native species richness are not resistant to colonisation by alien species at the global scale, and emphasise the likely ongoing threats to global environments from introductions of species.

  3. The Global Distribution and Drivers of Alien Bird Species Richness

    Science.gov (United States)

    Dyer, Ellie E.; Cassey, Phillip; Redding, David W.; Collen, Ben; Franks, Victoria; Gaston, Kevin J.; Jones, Kate E.; Kark, Salit; Orme, C. David L.; Blackburn, Tim M.

    2017-01-01

    Alien species are a major component of human-induced environmental change. Variation in the numbers of alien species found in different areas is likely to depend on a combination of anthropogenic and environmental factors, with anthropogenic factors affecting the number of species introduced to new locations, and when, and environmental factors influencing how many species are able to persist there. However, global spatial and temporal variation in the drivers of alien introduction and species richness remain poorly understood. Here, we analyse an extensive new database of alien birds to explore what determines the global distribution of alien species richness for an entire taxonomic class. We demonstrate that the locations of origin and introduction of alien birds, and their identities, were initially driven largely by European (mainly British) colonialism. However, recent introductions are a wider phenomenon, involving more species and countries, and driven in part by increasing economic activity. We find that, globally, alien bird species richness is currently highest at midlatitudes and is strongly determined by anthropogenic effects, most notably the number of species introduced (i.e., “colonisation pressure”). Nevertheless, environmental drivers are also important, with native and alien species richness being strongly and consistently positively associated. Our results demonstrate that colonisation pressure is key to understanding alien species richness, show that areas of high native species richness are not resistant to colonisation by alien species at the global scale, and emphasise the likely ongoing threats to global environments from introductions of species. PMID:28081142

  4. Impacts of invading alien plant species on water flows at stand and catchment scales

    Science.gov (United States)

    Le Maitre, D. C.; Gush, M. B.; Dzikiti, S.

    2015-01-01

    There have been many studies of the diverse impacts of invasions by alien plants but few have assessed impacts on water resources. We reviewed the information on the impacts of invasions on surface runoff and groundwater resources at stand to catchment scales and covering a full annual cycle. Most of the research is South African so the emphasis is on South Africa's major invaders with data from commercial forest plantations where relevant. Catchment studies worldwide have shown that changes in vegetation structure and the physiology of the dominant plant species result in changes in surface runoff and groundwater discharge, whether they involve native or alien plant species. Where there is little change in vegetation structure [e.g. leaf area (index), height, rooting depth and seasonality] the effects of invasions generally are small or undetectable. In South Africa, the most important woody invaders typically are taller and deeper rooted than the native species. The impacts of changes in evaporation (and thus runoff) in dryland settings are constrained by water availability to the plants and, thus, by rainfall. Where the dryland invaders are evergreen and the native vegetation (grass) is seasonal, the increases can reach 300–400 mm/year. Where the native vegetation is evergreen (shrublands) the increases are ∼200–300 mm/year. Where water availability is greater (riparian settings or shallow water tables), invading tree water-use can reach 1.5–2.0 times that of the same species in a dryland setting. So, riparian invasions have a much greater impact per unit area invaded than dryland invasions. The available data are scattered and incomplete, and there are many gaps and issues that must be addressed before a thorough understanding of the impacts at the site scale can be gained and used in extrapolating to watershed scales, and in converting changes in flows to water supply system yields. PMID:25935861

  5. 8 CFR 241.21 - Stay of deportation of excluded alien.

    Science.gov (United States)

    2010-01-01

    ... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Stay of deportation of excluded alien. 241.21 Section 241.21 Aliens and Nationality DEPARTMENT OF HOMELAND SECURITY IMMIGRATION REGULATIONS APPREHENSION AND DETENTION OF ALIENS ORDERED REMOVED Deportation of Excluded Aliens (for Hearings...

  6. 8 CFR 241.24 - Notice to transportation line of alien's exclusion.

    Science.gov (United States)

    2010-01-01

    ... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Notice to transportation line of alien's exclusion. 241.24 Section 241.24 Aliens and Nationality DEPARTMENT OF HOMELAND SECURITY IMMIGRATION REGULATIONS APPREHENSION AND DETENTION OF ALIENS ORDERED REMOVED Deportation of Excluded Aliens (for...

  7. 8 CFR 208.5 - Special duties toward aliens in custody of DHS.

    Science.gov (United States)

    2010-01-01

    ... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Special duties toward aliens in custody of DHS. 208.5 Section 208.5 Aliens and Nationality DEPARTMENT OF HOMELAND SECURITY IMMIGRATION... duties toward aliens in custody of DHS. (a) General. When an alien in the custody of DHS requests...

  8. 8 CFR 274a.12 - Classes of aliens authorized to accept employment.

    Science.gov (United States)

    2010-01-01

    ... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Classes of aliens authorized to accept employment. 274a.12 Section 274a.12 Aliens and Nationality DEPARTMENT OF HOMELAND SECURITY IMMIGRATION REGULATIONS CONTROL OF EMPLOYMENT OF ALIENS Employment Authorization § 274a.12 Classes of aliens authorized...

  9. 8 CFR 1212.5 - Parole of aliens into the United States.

    Science.gov (United States)

    2010-01-01

    ... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Parole of aliens into the United States. 1212.5 Section 1212.5 Aliens and Nationality EXECUTIVE OFFICE FOR IMMIGRATION REVIEW, DEPARTMENT OF... INADMISSIBLE ALIENS; PAROLE § 1212.5 Parole of aliens into the United States. Procedures and standards for...

  10. Threat and management strategies of potentially invasive insects in China

    Institute of Scientific and Technical Information of China (English)

    ZHANG RunZhi; ZHANG YaPing; JIANG YouXu

    2009-01-01

    The Global Invasive Species Database, GISD, comprises 27 species of the most significant invasive alien insects in the world (through November, 2005), 6 of which are originally native to China, 11 are established in China, and 10 have a potential invasion threat to China. This paper discusses these species in terms of distribution, harmfulness and dispersal ways, and finds that: (ⅰ) Information regarding invasive insects in the GISD remains inadequate. Such harmful invasive species as Opogona sacchari (Bojer), Oracella acuta (Lobdell), and Dendroctonus valens LeConte are not included. (ⅱ) Ten species of invasive insects, particularly Lasius neglectus Van Loon and Linepithema humile (Mayr)which become established in areas near China, have the potential to become established in China. (ⅲ)Special attention should be paid to species from Asia and the Americas because of their greater Iikelihood of becoming established in China. Finally, some management strategies including legislation,quarantine, early warning, prevention and control are suggested.

  11. Threat and management strategies of potentially invasive insects in China

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    The Global Invasive Species Database, GISD, comprises 27 species of the most significant invasive alien insects in the world (through November, 2005), 6 of which are originally native to China, 11 are established in China, and 10 have a potential invasion threat to China. This paper discusses these species in terms of distribution, harmfulness and dispersal ways, and finds that: (i) Information re-garding invasive insects in the GISD remains inadequate. Such harmful invasive species as Opogona sacchari (Bojer), Oracella acuta (Lobdell), and Dendroctonus valens LeConte are not included. (ii) Ten species of invasive insects, particularly Lasius neglectus Van Loon and Linepithema humile (Mayr) which become established in areas near China, have the potential to become established in China. (iii) Special attention should be paid to species from Asia and the Americas because of their greater likeli-hood of becoming established in China. Finally, some management strategies including legislation, quarantine, early warning, prevention and control are suggested.

  12. Posterior alien hand syndrome: case report

    Energy Technology Data Exchange (ETDEWEB)

    Rohde, S.; Weidauer, S.; Lanfermann, H.; Zanella, F. [Institute of Neuroradiology, Johann Wolfgang Goethe University, Schleusenweg 2-16, 60528 Frankfurt am Main (Germany)

    2002-11-01

    The alien hand syndrome (AHS) is involuntary uncontrolled movement of an arm with a sense of estrangement from the limb itself. AHS was initially used to describe interhemispheric disconnection phenomena in patients with lesions in the anterior corpus callosum, but it has been found in patients with posterior cerebral lesions without involvement of the corpus callosum, for example parietal infarcts or corticobasal degeneration. The posterior alien hand syndrome is less frequent and presents with nonpurposive behaviour like lifting the arm or writhing fingers. We report an 80-year-old woman with a posterior AHS of the dominant right hand. MRI showed atrophy of the pre- and postcentral gyri without involvement of the corpus callosum. We discuss the aetiology of the posterior AHS and the differences from the anterior varieties. (orig.)

  13. Exoplanets finding, exploring, and understanding alien worlds

    CERN Document Server

    Kitchin, Chris

    2012-01-01

    Since 1992 there has been an explosion in the discovery of planets orbiting stars other than the Sun. There are now around 600 alien planets that we know about and that number is likely to break through the 1,000 ‘barrier’ within a couple of years. The recent launch of the Kepler space telescope specifically to look for new worlds opens the prospect of hundreds, maybe thousands, of further exoplanets being found. Many of these planets orbits stars that are not too different from the Sun, but they are so close in to their stars that their surfaces could be flooded with seas of molten lead – or even molten iron. Others orbit so far from their stars that they might as well be alone in interstellar space. A planet closely similar to the Earth has yet to be detected, but that (to us) epoch-making discovery is just a matter of time. Could these alien worlds could provide alternative homes for humankind, new supplies of mineral resources and might they might already be homes to alien life? Exoplanets: Finding,...

  14. Distribution and impact of the alien anemone Sagartia ornata in the West Coast National Park

    Directory of Open Access Journals (Sweden)

    Tamara B. Robinson

    2015-03-01

    Full Text Available Sagartia ornata is an alien anemone that occurs intertidally within the West Coast National Park (WCNP. Whilst baseline distributional data was gathered in 2001, the range and abundance of this alien has not been reassessed. The present study aimed to determine the current status and distribution of this anemone, to assess its diet so as to establish the role it may play as predator and to investigate its impact on sandy-shore communities. Sagartia ornata was found to be restricted to the WCNP, where it occurred in densities of up to 508 ± 218 individuals per m2 . Within the park the distribution of this anemone had changed. Populations were recorded in Nanozostera capensis seagrass beds for the first time and this alien was absent from two areas in which it had previously occurred. Diet analysis revealed indigenous polychaetes and amphipods as the dominant prey items consumed by S. ornata. This alien was found to significantly alter sandy-shore community structure, with differences caused primarily by increases in the abundance and biomass of the tanaid Anatanais gracilis and the polychaete Orbinia angrapequensis. Additionally, invaded areas supported significantly greater invertebrate diversity, density and biomass. It is concluded that whilst this anemone negatively affects native biota, its current dependence on restricted habitats precludes widespread impacts with the park.Conservation implications: With regard to conservation implications, this invasion should be routinely monitored outside the WCNP as in its native range S. ornata occurs on rocky shores and kelp holdfasts, suggesting a potential for spread along the west coast of South Africa.

  15. Global change and marine communities: Alien species and climate change

    Energy Technology Data Exchange (ETDEWEB)

    Occhipinti-Ambrogi, Anna [DET - Dip. di Ecologia del Territorio, Sezione di Ecologia, Universita degli Studi di Pavia, Via S. Epifanio 14, I-27100 Pavia (Italy)]. E-mail: occhipin@unipv.it

    2007-07-01

    Anthropogenic influences on the biosphere since the advent of the industrial age are increasingly causing global changes. Climatic change and the rising concentration of greenhouse gases in the atmosphere are ranking high in scientific and public agendas, and other components of global change are also frequently addressed, among which are the introductions of non indigenous species (NIS) in biogeographic regions well separated from the donor region, often followed by spectacular invasions. In the marine environment, both climatic change and spread of alien species have been studied extensively; this review is aimed at examining the main responses of ecosystems to climatic change, taking into account the increasing importance of biological invasions. Some general principles on NIS introductions in the marine environment are recalled, such as the importance of propagule pressure and of development stages during the time course of an invasion. Climatic change is known to affect many ecological properties; it interacts also with NIS in many possible ways. Direct (proximate) effects on individuals and populations of altered physical-chemical conditions are distinguished from indirect effects on emergent properties (species distribution, diversity, and production). Climatically driven changes may affect both local dispersal mechanisms, due to the alteration of current patterns, and competitive interactions between NIS and native species, due to the onset of new thermal optima and/or different carbonate chemistry. As well as latitudinal range expansions of species correlated with changing temperature conditions, and effects on species richness and the correlated extinction of native species, some invasions may provoke multiple effects which involve overall ecosystem functioning (material flow between trophic groups, primary production, relative extent of organic material decomposition, extent of benthic-pelagic coupling). Some examples are given, including a special

  16. Displacement of a native by an alien bumblebee: lower pollinator efficiency overcome by overwhelmingly higher visitation frequency.

    Science.gov (United States)

    Madjidian, Josefin A; Morales, Carolina L; Smith, Henrik G

    2008-07-01

    Biological invasions might constitute a major threat to mutualisms. Introduced pollinators might competitively displace their native counterparts, which in turn affects the pollination of native plants, if native and alien visitors differ in pollinator effectiveness. Since its invasion in 1994 into south-west Argentina, the introduced European bumblebee Bombus ruderatus has continuously increased in abundance, along with a simultaneous decrease in the abundance of the native Bombus dahlbomii. The latter is the only native bumblebee species of the temperate forests of southern South America, and the main pollinator of the endemic herb Alstroemeria aurea. In order to evaluate the impact of the ongoing displacement of the native by the alien bumblebee, we compared the pollinator effectiveness (i.e., the combination of pollinator efficiency per visit and visitation frequency) between both bumblebee species, as well as related pollinator traits that might account for potential differences in pollinator efficiency. Native Bombus dahlbomii, which has a larger body and spent more time per flower, was the more efficient pollinator compared to Bombus ruderatus, both in terms of quantity and quality of pollen deposited per visit. However, Bombus ruderatus was a much more frequent flower visitor than Bombus dahlbomii. As a consequence, Bombus ruderatus is nowadays a more effective pollinator of A. aurea than its native congener. Despite the lack of evidence of an increase in seed set at the population level, comparisons with historical records of Bombus dahlbomii abundances prior to Bombus ruderatus' invasion suggest that the overall pollination intensity of A. aurea might in fact have risen as a consequence of this invasion. Field experiments like these, that incorporate the natural variation in abundance of native and alien species, are powerful means to demonstrate that the consequences of invasions are more complex than previous manipulated and controlled experiments have

  17. Right Sensory Alien Hand Phenomenon from a Left Pontine Hemorrhage

    OpenAIRE

    Rafiei, Nastaran; Chang, Gregory Youngnam

    2009-01-01

    Background Acute onset of a sensory alien hand phenomenon has been observed only from a supratentorial lesion involving the non-dominant hand, mostly from a right posterior cerebral artery infarction. A single acute vascular lesion resulting in a dominant hand sensory alien hand syndrome has not been previously documented. Case Report A 78-year old right-handed woman exhibited right sensory alien hand phenomenon from a left pontine hemorrhage. Disturbance of proprioceptive input and visuospat...

  18. AliEn - ALICE environment on the GRID

    CERN Document Server

    Saiz, P; Buncic, P; Piskac, R; Revsbech, J E; Sego, V

    2003-01-01

    AliEn (http://alien.cern.ch) (ALICE Environment) is a Grid framework built on top of the latest Internet standards for information exchange and authentication (SOAP, PKI) and common Open Source components. AliEn provides a virtual file catalogue that allows transparent access to distributed datasets and a number of collaborating Web services which implement the authentication, job execution, file transport, performance monitor and event logging. In the paper we will present the architecture and components of the system.

  19. AliEn - ALICE environment on the GRID

    Energy Technology Data Exchange (ETDEWEB)

    Saiz, P. E-mail: pablo.saiz@cern.ch; Aphecetche, L.; Buncic, P.; Piskac, R.; Revsbech, J.-E.; Sego, V

    2003-04-21

    AliEn (http://alien.cern.ch) (ALICE Environment) is a Grid framework built on top of the latest Internet standards for information exchange and authentication (SOAP, PKI) and common Open Source components. AliEn provides a virtual file catalogue that allows transparent access to distributed datasets and a number of collaborating Web services which implement the authentication, job execution, file transport, performance monitor and event logging. In the paper we will present the architecture and components of the system.

  20. Risk assessment of riparian plant invasions into protected areas.

    Science.gov (United States)

    Foxcroft, Llewellyn C; Rouget, Mathieu; Richardson, David M

    2007-04-01

    Protected areas are becoming increasingly isolated. River corridors represent crucial links to the surrounding landscape but are also major conduits for invasion of alien species. We developed a framework to assess the risk that alien plants in watersheds adjacent to a protected area will invade the protected area along rivers. The framework combines species- and landscape-level approaches and has five key components: (1) definition of the geographical area of interest, (2) delineation of the domain into ecologically meaningful zones, (3) identification of the appropriate landscape units, (4) categorization of alien species and mapping of their distribution and abundance, and (5) definition of management options. The framework guides the determination of species distribution and abundance through successive, easily followed steps, providing the means for the assessment of areas of concern. We applied the framework to Kruger National Park (KNP) in South Africa. We recorded 231 invasive alien plant species (of which 79 were major invaders) in the domain. The KNP is facing increasing pressure from alien species in the upper regions of the drainage areas of neighboring watersheds. On the basis of the climatic modeling, we showed that most major riparian invaders have the ability to spread across the KNP should they be transported down the rivers. With this information, KNP managers can identify areas for proactive intervention, monitoring, and resource allocation. Even for a very large protected area such as the KNP, sustainable management of biodiversity will depend heavily on the response of land managers upstream managing alien plants. We suggest that this framework is applicable to plants and other passively dispersed species that invade protected areas situated at the end of a drainage basin.

  1. The Alienated Plot in The End of the Road

    Institute of Scientific and Technical Information of China (English)

    王丽娜

    2014-01-01

    The End of the Road is John Barth’s second novel, and it is the first novel that brought abortion to the focus of public attention, which proves to be a huge success. This paper intends to study the alienation in The End of the Road based on the alienation as a literary style and the alienation embodied in the literary context. Through the analysis of the alienated plot, the pa-per aims to emphasize the internal cause for the end of the different character ’s road.

  2. 77 FR 23391 - Guidance on Reporting Interest Paid to Nonresident Aliens

    Science.gov (United States)

    2012-04-19

    ... Nonresident Aliens AGENCY: Internal Revenue Service (IRS), Treasury. ACTION: Final regulations. SUMMARY: This... alien individuals. These regulations will affect commercial banks, savings institutions, credit unions... companies that maintain deposit accounts for nonresident alien individuals. An agency may not conduct...

  3. 77 FR 4822 - Extension of Agency Information Collection Activity Under OMB Review: Flight Training for Aliens...

    Science.gov (United States)

    2012-01-31

    ... OMB Review: Flight Training for Aliens and Other Designated Individuals; Security Awareness Training... involves collecting information for background checks for all aliens and other designated individuals.... Information Collection Requirement Title: Flight Training for Aliens and Other Designated...

  4. THE ALIEN STREET TREES OF FORTALEZA (NE BRAZIL: QUALITATIVE OBSERVATIONS AND THE INVENTORY OF TWO DISTRICTS

    Directory of Open Access Journals (Sweden)

    Marcelo Freire Moro

    2011-01-01

    Full Text Available Public tree planting is important for cities. It produces shadow, brings well-being for humans, and supports the urban fauna. But the cultivation of exotic plants can also be responsible for dissemination of invasive species. This paper aims to evaluate public tree planting in Fortaleza, Ceará state, in northeastern Brazil. From 2005 to 2009, qualitative observations on tree composition in the city were made. In 2006, a detailed inventory of all public trees was carried out in two districts of Fortaleza. Jointly, 2075 individuals grew here. Most of the tree species planted in Fortaleza are aliens, some are even invasive. The massive use of exotic plants in Fortaleza has negative consequences for the environmental education. People do not know the regional native trees, and thus are not concerned about the local biodiversity conservation. In spite of the huge amounts of native species available for ornamental purposes in the Brazilian flora, the street trees of Fortaleza are overwhelmingly aliens.

  5. Application of Open-hydrostatic Slider Driven by Linear Motor in Grinding Machine%由直线电机驱动的静压导轨在磨床上的应用

    Institute of Scientific and Technical Information of China (English)

    潘慧; 范晓; 戴惠良

    2012-01-01

    介绍开式液体静压导轨的原理以及应用于磨床的设计过程,同时根据静压导轨的计算结果选择合适的直线电机,并总结了直线电机驱动的静压导轨的优点.%The principles of the open-hydrostatic slider and its application in the designing process of grinding machine were introduced. According to the calculating results of the open-hydrostatic slider, the right linear motor was chosen. The advantages of open-hydrostatic slider driven by linear motor were summarized.

  6. Plant invasions--the role of mutualisms.

    Science.gov (United States)

    Richardson, D M; Allsopp, N; D'Antonio, C M; Milton, S J; Rejmánek, M

    2000-02-01

    Many introduced plant species rely on mutualisms in their new habitats to overcome barriers to establishment and to become naturalized and, in some cases, invasive. Mutualisms involving animal-mediated pollination and seed dispersal, and symbioses between plant roots and microbiota often facilitate invasions. The spread of many alien plants, particularly woody ones, depends on pollinator mutualisms. Most alien plants are well served by generalist pollinators (insects and birds), and pollinator limitation does not appear to be a major barrier for the spread of introduced plants (special conditions relating to Ficus and orchids are described). Seeds of many of the most notorious plant invaders are dispersed by animals, mainly birds and mammals. Our review supports the view that tightly coevolved, plant-vertebrate seed dispersal systems are extremely rare. Vertebrate-dispersed plants are generally not limited reproductively by the lack of dispersers. Most mycorrhizal plants form associations with arbuscular mycorrhizal fungi which, because of their low specificity, do not seem to play a major role in facilitating or hindering plant invasions (except possibly on remote islands such as the Galapagos which are poor in arbuscular mycorrhizal fungi). The lack of symbionts has, however, been a major barrier for many ectomycorrhizal plants, notably for Pinus spp. in parts of the southern hemisphere. The roles of nitrogen-fixing associations between legumes and rhizobia and between actinorhizal plants and Frankia spp. in promoting or hindering invasions have been virtually ignored in the invasions literature. Symbionts required to induce nitrogen fixation in many plants are extremely widespread, but intentional introductions of symbionts have altered the invasibility of many, if not most, systems. Some of the world's worst invasive alien species only invaded after the introduction of symbionts. Mutualisms in the new environment sometimes re-unite the same species that form

  7. Invasive species

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This is a summary of management activities and research related to invasive species on Neal Smith National Wildlife Refuge between 1992 and 2009. As part of the...

  8. Climate change and biological invasions: evidence, expectations, and response options.

    Science.gov (United States)

    Hulme, Philip E

    2016-05-31

    A changing climate may directly or indirectly influence biological invasions by altering the likelihood of introduction or establishment, as well as modifying the geographic range, environmental impacts, economic costs or management of alien species. A comprehensive assessment of empirical and theoretical evidence identified how each of these processes is likely to be shaped by climate change for alien plants, animals and pathogens in terrestrial, freshwater and marine environments of Great Britain. The strongest contemporary evidence for the potential role of climate change in the establishment of new alien species is for terrestrial arthropods, as a result of their ectothermic physiology, often high dispersal rate and their strong association with trade as well as commensal relationships with human environments. By contrast, there is little empirical support for higher temperatures increasing the rate of alien plant establishment due to the stronger effects of residence time and propagule pressure. The magnitude of any direct climate effect on the number of new alien species will be small relative to human-assisted introductions driven by socioeconomic factors. Casual alien species (sleepers) whose population persistence is limited by climate are expected to exhibit greater rates of establishment under climate change assuming that propagule pressure remains at least at current levels. Surveillance and management targeting sleeper pests and diseases may be the most cost-effective option to reduce future impacts under climate change. Most established alien species will increase their distribution range in Great Britain over the next century. However, such range increases are very likely be the result of natural expansion of populations that have yet to reach equilibrium with their environment, rather than a direct consequence of climate change. To assess the potential realised range of alien species will require a spatially explicit approach that not only

  9. 76 FR 2852 - Guidance on Reporting Interest Paid to Nonresident Aliens; Correction

    Science.gov (United States)

    2011-01-18

    ... Nonresident Aliens; Correction AGENCY: Internal Revenue Service (IRS), Treasury. ACTION: Correction to a... nonresident alien individuals. FOR FURTHER INFORMATION CONTACT: Kathryn Holman, (202) 622-3840 (not a...

  10. 76 FR 7757 - Guidance on Reporting Interest Paid to Nonresident Aliens; Correction

    Science.gov (United States)

    2011-02-11

    ... Nonresident Aliens; Correction AGENCY: Internal Revenue Service (IRS), Treasury. ACTION: Correction to notice... and paid to nonresident alien individuals. FOR FURTHER INFORMATION CONTACT: Kathryn Holman at...

  11. Dispersal and predation in alien Acacia.

    Science.gov (United States)

    Holmes, P M

    1990-06-01

    I investigated seed removal in the litter layer of alien Acacia stands at bimonthly intervals throughout one year. Both ants (dispersers) and rodents (predators) removed significant quantities of seeds and may compete for seeds in low density Acacia stands. Seed removal from depots was greatest prior to seed-fall (Sept.-Nov.) and lowest during seed-fall (Jan.-Mar.). As rodents may consume a large proportion of the annual seed production at low Acacia densities, I propose that ants have played a critical role in accumulating Acacia seed banks.

  12. 42 CFR 435.350 - Coverage for certain aliens.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 4 2010-10-01 2010-10-01 false Coverage for certain aliens. 435.350 Section 435... ISLANDS, AND AMERICAN SAMOA Optional Coverage of the Medically Needy § 435.350 Coverage for certain aliens... treatment of an emergency medical condition, as defined in § 440.255(c) of this chapter, to those...

  13. Language Skill Definition: A Study of Legalized Aliens.

    Science.gov (United States)

    Chiswick, Barry R.; Miller, Paul W.

    1998-01-01

    Analyzes measures of language skills of legalized aliens using data from the Legalized Population Survey (LPS) of aliens who received amnesty under the 1986 Immigration Reform and Control Act. Includes self-assessed overall speaking skills, speaking and reading in specific situations, and perceptions of the impact of language skills on job…

  14. Alienation in College Students: A Rational and Semantic Analysis.

    Science.gov (United States)

    Moore, Robert M.

    This research project examined the relationship between the psycho-social malaise, alienation or anomia, and each of four psycholinguistic or semantic habit patterns: irrational ideation, identity orientation, uncritical inference behavior and allness orientation. In so doing, it sought, generally, to explicate alienation in terms of semantic…

  15. Making Marx Accessible: Understanding Alienated Labor through Experiential Learning

    Science.gov (United States)

    Parrotta, Kylie L.; Buck, Alison R.

    2013-01-01

    We introduce an exercise designed to make Marx's theory of alienated labor accessible to students in a Sociology of Work class. Through a role-playing activity where students create and sell goods under conditions of both alienated and nonalienated labor, students actually experience the different material and social consequences of these…

  16. How far could the alien boatman Trichocorixa verticalis verticalis spread? Worldwide estimation of its current and future potential distribution.

    Science.gov (United States)

    Guareschi, Simone; Coccia, Cristina; Sánchez-Fernández, David; Carbonell, José Antonio; Velasco, Josefa; Boyero, Luz; Green, Andy J; Millán, Andrés

    2013-01-01

    Invasions of alien species are considered among the least reversible human impacts, with diversified effects on aquatic ecosystems. Since prevention is the most cost-effective way to avoid biodiversity loss and ecosystem problems, one challenge in ecological research is to understand the limits of the fundamental niche of the species in order to estimate how far invasive species could spread. Trichocorixa verticalis verticalis (Tvv) is a corixid (Hemiptera) originally distributed in North America, but cited as an alien species in three continents. Its impact on native communities is under study, but it is already the dominant species in several saline wetlands and represents a rare example of an aquatic alien insect. This study aims: i) to estimate areas with suitable environmental conditions for Tvv at a global scale, thus identifying potential new zones of invasion; and ii) to test possible changes in this global potential distribution under a climate change scenario. Potential distributions were estimated by applying a multidimensional envelope procedure based on both climatic data, obtained from observed occurrences, and thermal physiological data. Our results suggest Tvv may expand well beyond its current range and find inhabitable conditions in temperate areas along a wide range of latitudes, with an emphasis on coastal areas of Europe, Northern Africa, Argentina, Uruguay, Australia, New Zealand, Myanmar, India, the western boundary between USA and Canada, and areas of the Arabian Peninsula. When considering a future climatic scenario, the suitability area of Tvv showed only limited changes compared with the current potential distribution. These results allow detection of potential contact zones among currently colonized areas and potential areas of invasion. We also identified zones with a high level of suitability that overlap with areas recognized as global hotspots of biodiversity. Finally, we present hypotheses about possible means of spread, focusing on

  17. How far could the alien boatman Trichocorixa verticalis verticalis spread? Worldwide estimation of its current and future potential distribution.

    Directory of Open Access Journals (Sweden)

    Simone Guareschi

    Full Text Available Invasions of alien species are considered among the least reversible human impacts, with diversified effects on aquatic ecosystems. Since prevention is the most cost-effective way to avoid biodiversity loss and ecosystem problems, one challenge in ecological research is to understand the limits of the fundamental niche of the species in order to estimate how far invasive species could spread. Trichocorixa verticalis verticalis (Tvv is a corixid (Hemiptera originally distributed in North America, but cited as an alien species in three continents. Its impact on native communities is under study, but it is already the dominant species in several saline wetlands and represents a rare example of an aquatic alien insect. This study aims: i to estimate areas with suitable environmental conditions for Tvv at a global scale, thus identifying potential new zones of invasion; and ii to test possible changes in this global potential distribution under a climate change scenario. Potential distributions were estimated by applying a multidimensional envelope procedure based on both climatic data, obtained from observed occurrences, and thermal physiological data. Our results suggest Tvv may expand well beyond its current range and find inhabitable conditions in temperate areas along a wide range of latitudes, with an emphasis on coastal areas of Europe, Northern Africa, Argentina, Uruguay, Australia, New Zealand, Myanmar, India, the western boundary between USA and Canada, and areas of the Arabian Peninsula. When considering a future climatic scenario, the suitability area of Tvv showed only limited changes compared with the current potential distribution. These results allow detection of potential contact zones among currently colonized areas and potential areas of invasion. We also identified zones with a high level of suitability that overlap with areas recognized as global hotspots of biodiversity. Finally, we present hypotheses about possible means of

  18. ALIEN MARINE SPECIES OF LIBYA: FIRST INVENTORY AND NEW RECORDS IN EL-KOUF NATIONAL PARK (CYRENAICA AND THE NEIGHBOURING AREAS

    Directory of Open Access Journals (Sweden)

    H. BAZAIRI

    2013-07-01

    Full Text Available The presence of marine alien species in El-Kouf National Park and the neighbouring areas was assessed using a compilation of available information and observations, a field survey conducted on October 2010 in the framework of the MedMPAnet project and results of further monitoring during June and September 2012. A total of 9 alien species were reported: the Rhodophyta Asparagopsis taxiformis (Delile Trevisan de Saint-Léon, the Chlorophyta Caulerpa racemosa var. cylindracea (Sonder Verlaque, Huisman & Boudouresque, the crab Percnon gibbesi (H. Milne-Edwards, 1853 and the fishes Fistularia commersonii Rüppell, 1838, Siganus luridus (Rüppell, 1829, Siganus rivulatus Forsskål, 1775, Pempheris vanicolensis Cuvier, 1831, Lagocephalus sceleratus (Gmelin, 1789 and Sphyraena flavicauda Rüppell, 1838. Several of them were until now unknown for the National Park. The list of alien marine species of Libya is updated and discussed. Until now 63 marine aliens species were recorded along the Libyan coasts. These include 3 Foraminifera, 3 Ochrophyta, 5 Rhodophyta, 5 Chlorophyta, 1 Magnoliophyta, 11 Arthropoda, 13 Mollusca, 1 Echinodermata and 21 Chordata. Among these Non Indigenous Species, 43 are known as established along the Libyan coast including 8 invasive, 11 casual, 6 questionable, 3 cryptogenic and 1 unknown. An in-depth study of the marine organisms would substantially increase the number of alien species occurring in Libya. Monitoring of marine assemblages of MPAs is a valuable opportunity to go further into the knowledge of native and introduced species.

  19. Do species differ in their ability to coexist with the dominant alien Lupinus polyphyllus? A comparison between two distinct invaded ranges and a native range

    Directory of Open Access Journals (Sweden)

    Martin Hejda

    2013-06-01

    Full Text Available The community-level impacts of invasive plants are likely to vary depending on the character of native species of the target communities and their ability to thrive within the stands of the dominant alien invader. Therefore, I examined the response of native species richness to the cover of the dominant alien Lupinus polyphyllus in two distinct invaded ranges: Czech Republic (Central Europe and New Zealand. I compared the relation between native species richness and the cover of the dominant alien L. polyphyllus with that in its native range, Pacific Northwest, USA.In the native range, I found no response of native species richness to the cover of L. polyphyllus. In the Czech Republic (central Europe, the richness of native species related to it negativelly, but the relation was only marginally significant. Contrary to that, the richness of species native to New Zealand related to the cover of L. polyphyllus strongly negatively and the negative relation was significantly stronger than that of species native to Europe.Of the two invaded ranges, species native to New Zealand have been documented to be much more vulnerable to the conditions associated with the invasion and dominance of L. polyphyllus, compared to species native to central Europe. This principle has been shown both across these two invaded ranges and in New Zealand, where the aliens of european origin successfully coexist with the dominant invasive alien L. polyphyllus. Similarly, species in the native range of L. polyphyllus showed no relation to its cover, indicating their ability to thrive even in dense stands of this dominant species.

  20. AliEn: ALICE environment on the GRID

    Energy Technology Data Exchange (ETDEWEB)

    Bagnasco, S; Betev, L; Buncic, P; Carminati, F; Cirstoiu, C; Grigoras, C; Hayrapetyan, A; Harutyunyan, A; Peters, A J; Saiz, P [CERN, European Organization for Nuclear Research, 1211 Geneve 23 (Switzerland)], E-mail: pablo.saiz@cern.ch

    2008-07-15

    Starting from mid-2008, the ALICE detector at CERN LHC will collect data at a rate of 4PB per year. ALICE will use exclusively distributed Grid resources to store, process and analyse this data. The top-level management of the Grid resources is done through the AliEn (ALICE Environment) system, which is in continuous development since year 2000. AliEn presents several original solutions, which have shown their viability in a number of large exercises of increasing complexity called Data Challenges. This paper describes the AliEn architecture: Job Management, Data Management and UI. The current status of AliEn will be illustrated, as well as the performance of the system during the data challenges. The paper also describes the future AliEn development roadmap.

  1. Alien macroalgae in Denmark - a broad-scale national perspective

    DEFF Research Database (Denmark)

    Thomsen, Mads S.; Wernberg, Thomas; Stæhr, Peter Anton

    2007-01-01

    Most studies documenting the importance of alien macroalgae relative to native species are based on smaller-scale sampling programmes. Between 1989 and 2003, a Danish monitoring programme collected data on the percentage cover of macroalgae at more than 600 locations throughout the country. We...... examined this data set to estimate the relative abundance of alien species in the algal flora on large spatiotemporal scales, i.e. across depth ranges, regions and years. Of the 10 alien macroalgal species known to inhabit Danish coastal waters, nine were found in the survey. Most of the alien species were...... only present in low quantities (alien species, Sargassum muticum and Bonnemaisonia hamifera, constituted 2-7% of the assemblages, depending on depth, region and year. Sargassum muticum was abundant from 0 to 5 m in the northwestern region...

  2. AliEn: ALICE Environment on the GRID

    CERN Multimedia

    Bagnasco, S; Buncic, P; Carminati, F; Cirstoiu, C; Grigoras, C; Hayrapetyan, A; Harutyunyan, A; Peters, A J; Saiz, P

    2007-01-01

    Starting from mid-2008, the ALICE detector at CERN LHC will collect data at a rate of 4PB per year. ALICE will use exclusively distributed Grid resources to store, process and analyse this data. The top-level management of the Grid resources is done through the AliEn (ALICE Environment) system, which is in continuous development since year 2000. AliEn presents several original solutions, which have shown their viability in a number of large exercises of increasing complexity called Data Challenges. This paper describes the AliEn architecture: Job Management, Data Management and UI. The current status of AliEn will be illustrated, as well as the performance of the system during the data challenges. The paper also describes the future AliEn development roadmap.

  3. Red swamp crayfish: biology, ecology and invasion - an overview

    OpenAIRE

    Tainã Gonçalves Loureiro; Pedro Manuel Silva Gentil Anastácio; Paula Beatriz de Araujo; Catherine Souty-Grosset; Mauricio Pereira Almerão

    2015-01-01

    ABSTRACTAlien species have been transported and traded by humans for many centuries. However, with the era of globalization, biological invasions have reached notable magnitudes. Currently, introduction of alien species is one of the major threats to biodiversity and ecosystem functioning. The North American crayfish Procambarus clarkii is one of the most widely introduced freshwater species in the world, especially due to its high economic importance. It is responsible for great modification...

  4. Evolution of "The New Frontier" in "Alien" and "Aliens": Patriarchal Co-optation of the Feminine Archetype.

    Science.gov (United States)

    Rushing, Janice Hocker

    1989-01-01

    Discusses feminine symbolism in the American frontier myth as an evolving cultural/rhetorical manifestation of a developing archetypal process. Analyzes the films "Alien" and "Aliens," in which the lost feminine is encountered, found to be vengeful of exploitation of her domain, and then killed by a patriarchalized heroine. (SR)

  5. Political Alienation among Migrant Youths: Exploring the Mechanisms of Political Alienation and Acculturation among Migrant Youths in Norwegian Schools

    Science.gov (United States)

    Solhaug, Trond

    2012-01-01

    This article addresses the following question: What characterizes the mechanisms of political alienation among non-Western immigrant students, and how might these mechanisms be related to student's acculturation attitudes? A theory of political alienation and acculturation is applied. Substantial quantitative data from Norwegian upper secondary…

  6. Purpose of Introduction as a Predictor of Invasiveness among Introduced Shrubs in Rwanda

    Directory of Open Access Journals (Sweden)

    Jean Leonard Seburanga

    2015-01-01

    Full Text Available The introduced shrub flora in Rwanda was analyzed and the risk of invasion was assessed based on the species’ purposes of introduction. The results showed that more than half of invasive alien shrubs in Rwanda were introduced as ornamentals. They include Agave americana L., Bryophyllum proliferum Bowie ex Hook., Caesalpinia decapetala (Roth Alston, Lantana camara L., and Tithonia diversifolia (Hemsley A. Gray. However, these represented only 3.16% of the total number of introduced ornamental shrubs. At the time when the study was conducted, no introduced food crop had become invasive. Species introduced for purposes other than food or culinary use showed higher likelihood of becoming invasive.

  7. Which factors affect the success or failure of eradication campaigns against alien species?

    Science.gov (United States)

    Pluess, Therese; Jarošík, Vojtěch; Pyšek, Petr; Cannon, Ray; Pergl, Jan; Breukers, Annemarie; Bacher, Sven

    2012-01-01

    Although issues related to the management of invasive alien species are receiving increasing attention, little is known about which factors affect the likelihood of success of management measures. We applied two data mining techniques, classification trees and boosted trees, to identify factors that relate to the success of management campaigns aimed at eradicating invasive alien invertebrates, plants and plant pathogens. We assembled a dataset of 173 different eradication campaigns against 94 species worldwide, about a half of which (50.9%) were successful. Eradications in man-made habitats, greenhouses in particular, were more likely to succeed than those in (semi-)natural habitats. In man-made habitats the probability of success was generally high in Australasia, while in Europe and the Americas it was higher for local infestations that are easier to deal with, and for international campaigns that are likely to profit from cross-border cooperation. In (semi-) natural habitats, eradication campaigns were more likely to succeed for plants introduced as an ornamental and escaped from cultivation prior to invasion. Averaging out all other factors in boosted trees, pathogens, bacteria and viruses were most, and fungi the least likely to be eradicated; for plants and invertebrates the probability was intermediate. Our analysis indicates that initiating the campaign before the extent of infestation reaches the critical threshold, starting to eradicate within the first four years since the problem has been noticed, paying special attention to species introduced by the cultivation pathway, and applying sanitary measures can substantially increase the probability of eradication success. Our investigations also revealed that information on socioeconomic factors, which are often considered to be crucial for eradication success, is rarely available, and thus their relative importance cannot be evaluated. Future campaigns should carefully document socioeconomic factors to

  8. Which factors affect the success or failure of eradication campaigns against alien species?

    Directory of Open Access Journals (Sweden)

    Therese Pluess

    Full Text Available Although issues related to the management of invasive alien species are receiving increasing attention, little is known about which factors affect the likelihood of success of management measures. We applied two data mining techniques, classification trees and boosted trees, to identify factors that relate to the success of management campaigns aimed at eradicating invasive alien invertebrates, plants and plant pathogens. We assembled a dataset of 173 different eradication campaigns against 94 species worldwide, about a half of which (50.9% were successful. Eradications in man-made habitats, greenhouses in particular, were more likely to succeed than those in (semi-natural habitats. In man-made habitats the probability of success was generally high in Australasia, while in Europe and the Americas it was higher for local infestations that are easier to deal with, and for international campaigns that are likely to profit from cross-border cooperation. In (semi- natural habitats, eradication campaigns were more likely to succeed for plants introduced as an ornamental and escaped from cultivation prior to invasion. Averaging out all other factors in boosted trees, pathogens, bacteria and viruses were most, and fungi the least likely to be eradicated; for plants and invertebrates the probability was intermediate. Our analysis indicates that initiating the campaign before the extent of infestation reaches the critical threshold, starting to eradicate within the first four years since the problem has been noticed, paying special attention to species introduced by the cultivation pathway, and applying sanitary measures can substantially increase the probability of eradication success. Our investigations also revealed that information on socioeconomic factors, which are often considered to be crucial for eradication success, is rarely available, and thus their relative importance cannot be evaluated. Future campaigns should carefully document

  9. Microbial diversity determines the invasion of soil by a bacterial pathogen

    NARCIS (Netherlands)

    van Elsas, Jan Dirk; Chiurazzi, Mario; Mallon, Cyrus A.; Elhottova, Dana; Kristufek, Vaclav; Salles, Joana Falcao

    2012-01-01

    Natural ecosystems show variable resistance to invasion by alien species, and this resistance can relate to the species diversity in the system. In soil, microorganisms are key components that determine life support functions, but the functional redundancy in the microbiota of most soils has long be

  10. 8 CFR 209.2 - Adjustment of status of alien granted asylum.

    Science.gov (United States)

    2010-01-01

    ... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Adjustment of status of alien granted asylum. 209.2 Section 209.2 Aliens and Nationality DEPARTMENT OF HOMELAND SECURITY IMMIGRATION REGULATIONS ADJUSTMENT OF STATUS OF REFUGEES AND ALIENS GRANTED ASYLUM § 209.2 Adjustment of status of...

  11. 8 CFR 214.11 - Alien victims of severe forms of trafficking in persons.

    Science.gov (United States)

    2010-01-01

    ... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Alien victims of severe forms of trafficking in persons. 214.11 Section 214.11 Aliens and Nationality DEPARTMENT OF HOMELAND SECURITY IMMIGRATION REGULATIONS NONIMMIGRANT CLASSES § 214.11 Alien victims of severe forms of trafficking in...

  12. 26 CFR 1.871-2 - Determining residence of alien individuals.

    Science.gov (United States)

    2010-04-01

    ... 26 Internal Revenue 9 2010-04-01 2010-04-01 false Determining residence of alien individuals. 1...) INCOME TAX (CONTINUED) INCOME TAXES Nonresident Aliens and Foreign Corporations § 1.871-2 Determining residence of alien individuals. (a) General. The term nonresident alien individual means an individual...

  13. 26 CFR 1.871-5 - Loss of residence by an alien.

    Science.gov (United States)

    2010-04-01

    ... 26 Internal Revenue 9 2010-04-01 2010-04-01 false Loss of residence by an alien. 1.871-5 Section 1... (CONTINUED) INCOME TAXES Nonresident Aliens and Foreign Corporations § 1.871-5 Loss of residence by an alien. An alien who has acquired residence in the United States retains his status as a resident until...

  14. 26 CFR 31.3402(f)(6)-1 - Withholding exemptions for nonresident alien individuals.

    Science.gov (United States)

    2010-04-01

    ... 26 Internal Revenue 15 2010-04-01 2010-04-01 false Withholding exemptions for nonresident alien... exemptions for nonresident alien individuals. A nonresident alien individual (other than, in regard to wages paid after February 28, 1979, a nonresident alien individual treated as a resident under section...

  15. 8 CFR 214.14 - Alien victims of certain qualifying criminal activity.

    Science.gov (United States)

    2010-01-01

    ... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Alien victims of certain qualifying criminal activity. 214.14 Section 214.14 Aliens and Nationality DEPARTMENT OF HOMELAND SECURITY IMMIGRATION REGULATIONS NONIMMIGRANT CLASSES § 214.14 Alien victims of certain qualifying criminal activity....

  16. 26 CFR 1.871-1 - Classification and manner of taxing alien individuals.

    Science.gov (United States)

    2010-04-01

    ... 26 Internal Revenue 9 2010-04-01 2010-04-01 false Classification and manner of taxing alien... (CONTINUED) INCOME TAX (CONTINUED) INCOME TAXES Nonresident Aliens and Foreign Corporations § 1.871-1 Classification and manner of taxing alien individuals. (a) Classes of aliens. For purposes of the income...

  17. 45 CFR Appendix to Part 1626 - Alien Eligibility for Representation by LSC Programs

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 4 2010-10-01 2010-10-01 false Alien Eligibility for Representation by LSC... SERVICES CORPORATION RESTRICTIONS ON LEGAL ASSISTANCE TO ALIENS Pt. 1626, App. Appendix to Part 1626—Alien Eligibility for Representation by LSC Programs Alien Eligibility for Representation by LSC Programs...

  18. 8 CFR 241.9 - Notice to transportation line of alien's removal.

    Science.gov (United States)

    2010-01-01

    ... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Notice to transportation line of alien's removal. 241.9 Section 241.9 Aliens and Nationality DEPARTMENT OF HOMELAND SECURITY IMMIGRATION REGULATIONS APPREHENSION AND DETENTION OF ALIENS ORDERED REMOVED Post-hearing Detention and Removal §...

  19. 8 CFR 1209.2 - Adjustment of status of alien granted asylum.

    Science.gov (United States)

    2010-01-01

    ... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Adjustment of status of alien granted asylum. 1209.2 Section 1209.2 Aliens and Nationality EXECUTIVE OFFICE FOR IMMIGRATION REVIEW, DEPARTMENT OF JUSTICE IMMIGRATION REGULATIONS ADJUSTMENT OF STATUS OF REFUGEES AND ALIENS GRANTED ASYLUM §...

  20. 26 CFR 1.871-4 - Proof of residence of aliens.

    Science.gov (United States)

    2010-04-01

    ... 26 Internal Revenue 9 2010-04-01 2010-04-01 false Proof of residence of aliens. 1.871-4 Section 1... (CONTINUED) INCOME TAXES Nonresident Aliens and Foreign Corporations § 1.871-4 Proof of residence of aliens... alien within the United States has acquired residence therein for purposes of the income tax....

  1. 8 CFR 212.5 - Parole of aliens into the United States.

    Science.gov (United States)

    2010-01-01

    ... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Parole of aliens into the United States. 212.5 Section 212.5 Aliens and Nationality DEPARTMENT OF HOMELAND SECURITY IMMIGRATION REGULATIONS DOCUMENTARY REQUIREMENTS: NONIMMIGRANTS; WAIVERS; ADMISSION OF CERTAIN INADMISSIBLE ALIENS; PAROLE §...

  2. 8 CFR 241.10 - Special care and attention of removable aliens.

    Science.gov (United States)

    2010-01-01

    ... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Special care and attention of removable aliens. 241.10 Section 241.10 Aliens and Nationality DEPARTMENT OF HOMELAND SECURITY IMMIGRATION REGULATIONS APPREHENSION AND DETENTION OF ALIENS ORDERED REMOVED Post-hearing Detention and Removal §...

  3. 8 CFR 1245.11 - Adjustment of aliens in S nonimmigrant classification.

    Science.gov (United States)

    2010-01-01

    ... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Adjustment of aliens in S nonimmigrant classification. 1245.11 Section 1245.11 Aliens and Nationality EXECUTIVE OFFICE FOR IMMIGRATION REVIEW... RESIDENCE § 1245.11 Adjustment of aliens in S nonimmigrant classification. (a) Eligibility. An...

  4. 8 CFR 241.3 - Detention of aliens during removal period.

    Science.gov (United States)

    2010-01-01

    ... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Detention of aliens during removal period. 241.3 Section 241.3 Aliens and Nationality DEPARTMENT OF HOMELAND SECURITY IMMIGRATION REGULATIONS APPREHENSION AND DETENTION OF ALIENS ORDERED REMOVED Post-hearing Detention and Removal § 241.3 Detention...

  5. 8 CFR 287.3 - Disposition of cases of aliens arrested without warrant.

    Science.gov (United States)

    2010-01-01

    ... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Disposition of cases of aliens arrested without warrant. 287.3 Section 287.3 Aliens and Nationality DEPARTMENT OF HOMELAND SECURITY IMMIGRATION REGULATIONS FIELD OFFICERS; POWERS AND DUTIES § 287.3 Disposition of cases of aliens arrested without...

  6. 8 CFR 245.11 - Adjustment of aliens in S nonimmigrant classification.

    Science.gov (United States)

    2010-01-01

    ... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Adjustment of aliens in S nonimmigrant classification. 245.11 Section 245.11 Aliens and Nationality DEPARTMENT OF HOMELAND SECURITY IMMIGRATION... aliens in S nonimmigrant classification. (a) Eligibility. An application on Form I-854, requesting...

  7. 8 CFR 234.4 - International airports for entry of aliens.

    Science.gov (United States)

    2010-01-01

    ... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false International airports for entry of aliens. 234.4 Section 234.4 Aliens and Nationality DEPARTMENT OF HOMELAND SECURITY IMMIGRATION REGULATIONS DESIGNATION OF PORTS OF ENTRY FOR ALIENS ARRIVING BY CIVIL AIRCRAFT § 234.4 International airports for...

  8. 22 CFR 40.93 - Aliens unlawfully present after previous immigration violation.

    Science.gov (United States)

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Aliens unlawfully present after previous... TO BOTH NONIMMIGRANTS AND IMMIGRANTS UNDER THE IMMIGRATION AND NATIONALITY ACT, AS AMENDED Aliens Previously Removed § 40.93 Aliens unlawfully present after previous immigration violation. An alien...

  9. 8 CFR 244.5 - Temporary treatment benefits for eligible aliens.

    Science.gov (United States)

    2010-01-01

    ... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Temporary treatment benefits for eligible aliens. 244.5 Section 244.5 Aliens and Nationality DEPARTMENT OF HOMELAND SECURITY IMMIGRATION... for eligible aliens. (a) Prior to the registration period. Prior to the registration...

  10. 8 CFR 241.14 - Continued detention of removable aliens on account of special circumstances.

    Science.gov (United States)

    2010-01-01

    ... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Continued detention of removable aliens on account of special circumstances. 241.14 Section 241.14 Aliens and Nationality DEPARTMENT OF HOMELAND SECURITY IMMIGRATION REGULATIONS APPREHENSION AND DETENTION OF ALIENS ORDERED REMOVED...

  11. 8 CFR 241.15 - Countries to which aliens may be removed.

    Science.gov (United States)

    2010-01-01

    ... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Countries to which aliens may be removed. 241.15 Section 241.15 Aliens and Nationality DEPARTMENT OF HOMELAND SECURITY IMMIGRATION REGULATIONS APPREHENSION AND DETENTION OF ALIENS ORDERED REMOVED Post-hearing Detention and Removal § 241.15 Countries...

  12. 8 CFR 245.23 - Adjustment of aliens in T nonimmigrant classification.

    Science.gov (United States)

    2010-01-01

    ... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Adjustment of aliens in T nonimmigrant classification. 245.23 Section 245.23 Aliens and Nationality DEPARTMENT OF HOMELAND SECURITY IMMIGRATION... aliens in T nonimmigrant classification. (a) Eligibility of principal T-1 applicants. Except as...

  13. 8 CFR 1244.5 - Temporary treatment benefits for eligible aliens.

    Science.gov (United States)

    2010-01-01

    ... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Temporary treatment benefits for eligible aliens. 1244.5 Section 1244.5 Aliens and Nationality EXECUTIVE OFFICE FOR IMMIGRATION REVIEW, DEPARTMENT... § 1244.5 Temporary treatment benefits for eligible aliens. (a) Prior to the registration period. Prior...

  14. 26 CFR 1.6851-2 - Certificates of compliance with income tax laws by departing aliens.

    Science.gov (United States)

    2010-04-01

    ... the taxable year; (c) An alien in transit through the United States or any of its possessions on a C-1... alien is in transit through the United States or any of its possessions; (e) An alien military trainee... fact that the alien intends to depart from the United States will justify termination of his...

  15. The Identification of Alienated Parents and Children: Implications for School Psychologists.

    Science.gov (United States)

    Calabrese, Raymond L.; And Others

    1987-01-01

    Examined predictors of parental alienation in parents of 49 urban midwestern fourth-graders using the Dean Alienation Scale. High levels of alienation were associated with single, unemployed female parents, whose child was a female with few perceived friends. In predicting parental level of alienation, race, achievement, and attendance were not…

  16. Alien hand syndrome: neural correlates of movements without conscious will.

    Directory of Open Access Journals (Sweden)

    Michael Schaefer

    Full Text Available BACKGROUND: The alien hand syndrome is a striking phenomenon characterized by purposeful and autonomous movements that are not voluntarily initiated. This study aimed to examine neural correlates of this rare neurological disorder in a patient with corticobasal degeneration and alien hand syndrome of the left hand. METHODOLOGY/PRINCIPAL FINDINGS: We employed functional magnetic resonance imaging to investigate brain responses associated with unwanted movements in a case study. Results revealed that alien hand movements involved a network of brain activations including the primary motor cortex, premotor cortex, precuneus, and right inferior frontal gyrus. Conscious and voluntary movements of the alien hand elicited a similar network of brain responses but lacked an activation of the inferior frontal gyrus. The results demonstrate that alien and unwanted movements may engage similar brain networks than voluntary movements, but also imply different functional contributions of prefrontal areas. Since the inferior frontal gyrus was uniquely activated during alien movements, the results provide further support for a specific role of this brain region in inhibitory control over involuntary motor responses. CONCLUSIONS/SIGNIFICANCE: We discuss the outcome of this study as providing evidence for a distributed neural network associated with unwanted movements in alien hand syndrome, including brain regions known to be related to movement execution and planning as well as areas that have been linked to inhibition control (inferior frontal gyrus and experience of agency (precuneus.

  17. The Relationship between Teachers’ Occupational Professionalism and Organizational Alienation

    Directory of Open Access Journals (Sweden)

    Yilmaz Ilker Yorulmaz

    2015-11-01

    Full Text Available The purpose of this study is to determine the relationship between occupational professionalism and organizational alienation levels of teachers. The study is designed as a survey model. The sample of the study consists of 303 teachers working in the Mugla province of Turkey. Participants were selected by using the disproportionate cluster sampling technique. Data was collected through the application of the Teachers’ Occupational Professionalism Scale and the Work Alienation Scale. Descriptive statistics, t-test, ANOVA and correlation analyses were used to analyze the data. Based on the findings, the participant teachers’ level of occupational professionalism is high. Among the occupational professionalism dimensions, teachers consider they have professional awareness the most. This is followed by emotional labor, contribution to organization, and personal development. Teachers’ occupational professionalism differ according to gender and school type variables, while it does not differ according to seniority and time in service at the current school. The participant teachers’ organizational alienation is low. Among the alienation dimensions, teachers consider alienating the school the most, even if its level is low. This is followed respectively by powerlessness, isolation and meaninglessness dimensions. Teachers’ organizational alienation differs according to gender, school type, seniority and time in service at the current school variables. There are significant relationships between alienation and occupational professionalism levels of teachers.

  18. 分子间作用力对超低飞高磁头动态飞行特性的影响%Effects of intermolecular forces on dynamic flying characteristics of an ultra-low flying height slider

    Institute of Scientific and Technical Information of China (English)

    王玉娟; 梁丽; 陈云飞

    2013-01-01

    The Reynolds lubrication and motion equations of a pico slider with a fly height of 3.5 nm is resolved by using the finite control volume method and the third-order Runge-Kutta method. The influence of intermolecular forces on the flying attitude of the slider when it flies over a rectan-gular step on the disk is studied,and time-domain analysis of the interface between the slider and disk is conducted.Simulation results show that the dynamic flight stability of the slider is destroyed by intermolecular forces between the slider and the disk when the slider flies over a rectangular step on the disk in a system with an ultra-low flying height,which is an important factor in causing inter-face failures between the slider and the disk.Furthermore,approaches to reducing intermolecular forces are proposed,such as rationally designing the geometric parameters of the slider to reduce the area of the rear pad of the slider,and improving the surface evenness of the disk,which can further improve the stability of the interface between the slider and the disk.%以飞高为3.5 nm 的皮米磁头为研究对象,采用有限控制体法和三阶 Runge-Kutta 方法,求解磁头的雷诺方程和运动学方程.得出磁头飞跃盘面凸起障碍过程中头盘间分子间作用力对其飞行姿态的影响,并对磁头磁盘界面进行时域分析.模拟结果表明:超低飞高情况下,磁头飞跃盘面凸起障碍时,分子间作用力破坏了磁头动态飞行稳定性,它是引起头盘界面失效的一个重要因素.在此基础上,提出了降低分子间作用力的方法,如合理设计头盘界面几何参数以适当减小磁头尾部凸缘的面积,或者提高磁盘的表面质量以降低磁盘面的不平整度.以上措施都可以有效降低分子间作用力的不利影响,提高头盘界面稳定性.

  19. Impact of invasive plants on food webs and pathways

    Directory of Open Access Journals (Sweden)

    Sikai Wang

    2013-05-01

    Full Text Available In natural ecosystems, energy mainly flows along food chains in food webs. Numerous studies have shown that plant invasions influence ecosystem functions through altering food webs. In recent decades, more attention has been paid to the effects of alien plants on local food webs. In this review, we analyze the influence of exotic plants on food webs and pathways, and explore the impacts of local food web characteristics on community invasibility. Invasive plants alter food webs mainly by changing basal resources and environment conditions in different ways. First, they are consumed by native herbivores due to their high availability, and are therefore incorporated into the native food web. Second, if they show low availability to native herbivores, a new food web is generated through introduction of new consumers or by changing the energy pathway. Third, environmental changes induced by plant invasions may alter population density and feeding behavior of various species at different trophic levels, thus alien plants will affect the communities and food web structures along non-trophic pathways. The influence of the local food web on plant invasions depends on web size and trophic connections. Issues that deserve attention in future studies are raised and discussed. Future research should extend from short-term experiments to long-term monitoring. More quantitative researches to define the responses of food web parameters are needed. In addition, recovering of food web structure and species interaction in restored habitats is an important issue requiring future research.

  20. Soil sustainability study in Lithuanian alien forest stands

    Science.gov (United States)

    Čiuldiene, Dovile; Skridlaite, Grazina; Žalūdiene, Gaile; Askelsson, Cecilia; Armolaitis, Kestutis

    2016-04-01

    Tree species are shifting their natural ranges in response to climate changes (Saltré et al., 2013). Northern red oak has originated from North America, but was planted in Europe already in twentieth century. At present, it is considered as invasive species in Poland and at invasive stage in the Lithuanian forests (Riepsas and Straigyte, 2008). European larch naturally grows in Central Europe, but its range has been extended by planting it as far as the Nordic countries. According to a pollen study in peat soils, European larch naturally grew in Lithuania in the sixteenth century and was reintroduced 200 years ago (Jankauskas, 1954). Therefore, the global warming could accelerate the expansion of European larch and Northern red oak into Lithuanian forests. An urgent need appeared to evaluate an impact of those warmth-tolerant species on soil mineral chemistry and quality. New results on the determination of mineral weathering rates in alien forest stands using a PROFILE soil chemistry model were obtained during a doctoral study at the Institute of Forestry. Soil minerals were studied by a Scanning Electron Microscopy at the Institute of Geology and Geography. The results provided a lot of new information on soil weathering rates in Lithuania. The 47 and 157-year-old European larch (Larix decidua Mill.), 45 and 55-year-old Northern red oak (Quercus rubra L.) plantations and adjacent perennial grasslands were chosen for this study. The soils were classified as Luvisols and were developed from glaciofluvial deposits. The PROFILE model requires data of climate conditions (mean annual temperature and precipitation), chemical parameters of atmospheric deposition, forest plantation dendrometric and chemical (wood, foliage litter fall) characteristics, soil physical characteristics and mineral composition. A cation weathering rate (sum of Ca+Mg+ K) is 30% higher in a soil under the Northern red oak than in adjacent perennial grassland. Meanwhile, cation weathering rates