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Sample records for invasion success facilitated

  1. Do defensive chemicals facilitate intraguild predation and influence invasion success in ladybird beetles?

    PubMed

    Kajita, Yukie; Obrycki, John J; Sloggett, John J; Evans, Edward W; Haynes, Kenneth F

    2014-12-01

    Egg predation and cannibalism are believed to be common phenomena among many species of aphidophagous predatory ladybird beetles despite the presence of alkaloid based defensive chemicals in all life stages. We identified defensive chemicals from eggs of three congeneric species, one introduced into North America (Coccinella septempunctata L.), and two native (C. transversoguttata richardsoni Brown, and C. novemnotata Herbst), and examined the effects of ingested defensive chemicals on first instars. Ingested congeneric alkaloids were not toxic to first instars, likely because the three congeners produce the same principal alkaloids, precoccinelline and coccinelline, in similar amounts. First instars of the three congeners accumulated alkaloids ingested through egg cannibalism and congeneric predation. Egg consumption doubled the amount of alkaloids in first instars when they fed on conspecific or congeneric eggs, in comparison to a pea aphid diet. No detrimental effects of ingested congeneric alkaloids on development or survival of first instars were observed among these congeners. Chemical defenses of eggs are therefore not likely to be important in favoring the invasive species, C. septempunctata, in interactions with these native congeneric species. Because the invasive species is the most aggressive predator, having the same types of alkaloids may facilitate disproportionate intraguild predation on native congeners by C. septempunctata thereby potentially enhancing the invasion success of this introduced species. PMID:25380992

  2. Do defensive chemicals facilitate intraguild predation and influence invasion success in ladybird beetles?

    PubMed

    Kajita, Yukie; Obrycki, John J; Sloggett, John J; Evans, Edward W; Haynes, Kenneth F

    2014-12-01

    Egg predation and cannibalism are believed to be common phenomena among many species of aphidophagous predatory ladybird beetles despite the presence of alkaloid based defensive chemicals in all life stages. We identified defensive chemicals from eggs of three congeneric species, one introduced into North America (Coccinella septempunctata L.), and two native (C. transversoguttata richardsoni Brown, and C. novemnotata Herbst), and examined the effects of ingested defensive chemicals on first instars. Ingested congeneric alkaloids were not toxic to first instars, likely because the three congeners produce the same principal alkaloids, precoccinelline and coccinelline, in similar amounts. First instars of the three congeners accumulated alkaloids ingested through egg cannibalism and congeneric predation. Egg consumption doubled the amount of alkaloids in first instars when they fed on conspecific or congeneric eggs, in comparison to a pea aphid diet. No detrimental effects of ingested congeneric alkaloids on development or survival of first instars were observed among these congeners. Chemical defenses of eggs are therefore not likely to be important in favoring the invasive species, C. septempunctata, in interactions with these native congeneric species. Because the invasive species is the most aggressive predator, having the same types of alkaloids may facilitate disproportionate intraguild predation on native congeners by C. septempunctata thereby potentially enhancing the invasion success of this introduced species.

  3. Experimental evaluation of predation as a facilitator of invasion success in a stream fish.

    PubMed

    Fraser, Douglas F; Lamphere, Bradley A

    2013-03-01

    Predator-prey relationships in poikilotherms are often size dependent, such as when adults of two interacting species are capable of eating juveniles of the other species. Such bi-directional predation can be important during the establishment and spread of an invading species, but its role remains poorly understood. Using a combination of laboratory and mesocosm experiments and field introductions, we demonstrate that guppies, Poecilia reticulata, prey on juvenile killifish, Rivulus hartii, and thereby facilitate their establishment in the habitat of a potential predator. Laboratory studies found that mature guppies can consume larval Rivulus, and experimental stream studies showed that guppies reduced the number of Rivulus surviving from eggs. Growth trials found that interspecific competition, while significant, cannot account for the declines in the survival of juvenile Rivulus seen in field surveys. Finally, a field experiment, in which guppies were introduced into previously guppy-free stream reaches, resulted in a marked reduction in the abundance of juvenile Rivulus relative to guppy-free controls. Together, these results indicate that reducing the native Rivulus population represents an important.mechanism promoting guppy invasion success. PMID:23687890

  4. Hybridization increases invasive knotweed success

    PubMed Central

    Parepa, Madalin; Fischer, Markus; Krebs, Christine; Bossdorf, Oliver

    2014-01-01

    Hybridization is one of the fundamental mechanisms by which rapid evolution can occur in exotic species. If hybrids show increased vigour, this could significantly contribute to invasion success. Here, we compared the success of the two invasive knotweeds, Fallopia japonica and F. sachalinensis, and their hybrid, F. × bohemica, in competing against experimental communities of native plants. Using plant material from multiple clones of each taxon collected across a latitudinal gradient in Central Europe, we found that knotweed hybrids performed significantly better in competition with a native community and that they more strongly reduced the growth of the native plants. One of the parental species, F. sachalinensis, regenerated significantly less well from rhizomes, and this difference disappeared if activated carbon was added to the substrate, which suggests allelopathic inhibition of F. sachalinensis regeneration by native plants. We found substantial within-taxon variation in competitive success in all knotweed taxa, but variation was generally greatest in the hybrid. Interestingly, there was also significant variation within the genetically uniform F. japonica, possibly reflecting epigenetic differences. Our study shows that invasive knotweed hybrids are indeed more competitive than their parents and that hybridization increased the invasiveness of the exotic knotweed complex. PMID:24665343

  5. Hybridization increases invasive knotweed success.

    PubMed

    Parepa, Madalin; Fischer, Markus; Krebs, Christine; Bossdorf, Oliver

    2014-03-01

    Hybridization is one of the fundamental mechanisms by which rapid evolution can occur in exotic species. If hybrids show increased vigour, this could significantly contribute to invasion success. Here, we compared the success of the two invasive knotweeds, Fallopia japonica and F. sachalinensis, and their hybrid, F. × bohemica, in competing against experimental communities of native plants. Using plant material from multiple clones of each taxon collected across a latitudinal gradient in Central Europe, we found that knotweed hybrids performed significantly better in competition with a native community and that they more strongly reduced the growth of the native plants. One of the parental species, F. sachalinensis, regenerated significantly less well from rhizomes, and this difference disappeared if activated carbon was added to the substrate, which suggests allelopathic inhibition of F. sachalinensis regeneration by native plants. We found substantial within-taxon variation in competitive success in all knotweed taxa, but variation was generally greatest in the hybrid. Interestingly, there was also significant variation within the genetically uniform F. japonica, possibly reflecting epigenetic differences. Our study shows that invasive knotweed hybrids are indeed more competitive than their parents and that hybridization increased the invasiveness of the exotic knotweed complex. PMID:24665343

  6. Invasional meltdown: invader-invader mutualism facilitates a secondary invasion.

    PubMed

    Green, Peter T; O'Dowd, Dennis J; Abbott, Kirsti L; Jeffery, Mick; Retallick, Kent; Mac Nally, Ralph

    2011-09-01

    In multiply invaded ecosystems, introduced species should interact with each other as well as with native species. Invader-invader interactions may affect the success of further invaders by altering attributes of recipient communities and propagule pressure. The invasional meltdown hypothesis (IMH) posits that positive interactions among invaders initiate positive population-level feedback that intensifies impacts and promotes secondary invasions. IMH remains controversial: few studies show feedback between invaders that amplifies their effects, and none yet demonstrate facilitation of entry and spread of secondary invaders. Our results show that supercolonies of an alien ant, promoted by mutualism with introduced honeydew-secreting scale insects, permitted invasion by an exotic land snail on Christmas Island, Indian Ocean. Modeling of land snail spread over 750 sites across 135 km2 over seven years showed that the probability of land snail invasion was facilitated 253-fold in ant supercolonies but impeded in intact forest where predaceous native land crabs remained abundant. Land snail occurrence at neighboring sites, a measure of propagule pressure, also promoted land snail spread. Site comparisons and experiments revealed that ant supercolonies, by killing land crabs but not land snails, disrupted biotic resistance and provided enemy-free space. Predation pressure on land snails was lower (28.6%), survival 115 times longer, and abundance 20-fold greater in supercolonies than in intact forest. Whole-ecosystem suppression of supercolonies reversed the probability of land snail invasion by allowing recolonization of land crabs; land snails were much less likely (0.79%) to invade sites where supercolonies were suppressed than where they remained intact. Our results provide strong empirical evidence for IMH by demonstrating that mutualism between invaders reconfigures key interactions in the recipient community. This facilitates entry of secondary invaders and

  7. Will extreme climatic events facilitate biological invasions?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Extreme climatic events, such as intense heat waves, hurricanes, floods and droughts, can dramatically affect ecological and evolutionary processes, and more extreme events are projected with ongoing climate change. However, the implications of these events for biological invasions, which themselves...

  8. Sea Urchins Predation Facilitates Coral Invasion in a Marine Reserve

    PubMed Central

    Coma, Rafel; Serrano, Eduard; Linares, Cristina; Ribes, Marta; Díaz, David; Ballesteros, Enric

    2011-01-01

    Macroalgae is the dominant trophic group on Mediterranean infralittoral rocky bottoms, whereas zooxanthellate corals are extremely rare. However, in recent years, the invasive coral Oculina patagonica appears to be increasing its abundance through unknown means. Here we examine the pattern of variation of this species at a marine reserve between 2002 and 2010 and contribute to the understanding of the mechanisms that allow its current increase. Because indirect interactions between species can play a relevant role in the establishment of species, a parallel assessment of the sea urchin Paracentrotus lividus, the main herbivorous invertebrate in this habitat and thus a key species, was conducted. O. patagonica has shown a 3-fold increase in abundance over the last 8 years and has become the most abundant invertebrate in the shallow waters of the marine reserve, matching some dominant erect macroalgae in abundance. High recruitment played an important role in this increasing coral abundance. The results from this study provide compelling evidence that the increase in sea urchin abundance may be one of the main drivers of the observed increase in coral abundance. Sea urchins overgraze macroalgae and create barren patches in the space-limited macroalgal community that subsequently facilitate coral recruitment. This study indicates that trophic interactions contributed to the success of an invasive coral in the Mediterranean because sea urchins grazing activity indirectly facilitated expansion of the coral. Current coral abundance at the marine reserve has ended the monopolization of algae in rocky infralittoral assemblages, an event that could greatly modify both the underwater seascape and the sources of primary production in the ecosystem. PMID:21789204

  9. SUCCESS@Seneca: Facilitating Student and Staff Success

    ERIC Educational Resources Information Center

    Fishman, Steve; Decandia, Lisa

    2006-01-01

    SUCCESS@Seneca has teamed up with the General Arts and Science programs at Seneca's Newnham campus. The design of an integrated service delivery model addresses numerous student success and retention related activities by providing the essential connection between academics and college resources. The program focuses on the promotion and support of…

  10. Linking climate change and biological invasions: Ocean warming facilitates nonindigenous species invasions.

    PubMed

    Stachowicz, John J; Terwin, Jeffrey R; Whitlatch, Robert B; Osman, Richard W

    2002-11-26

    The spread of exotic species and climate change are among the most serious global environmental threats. Each independently causes considerable ecological damage, yet few data are available to assess whether changing climate might facilitate invasions by favoring introduced over native species. Here, we compare our long-term record of weekly sessile marine invertebrate recruitment with interannual variation in water temperature to assess the likely effect of climate change on the success and spread of introduced species. For the three most abundant introduced species of ascidian (sea squirt), the timing of the initiation of recruitment was strongly negatively correlated with winter water temperature, indicating that invaders arrived earlier in the season in years with warmer winters. Total recruitment of introduced species during the following summer also was positively correlated with winter water temperature. In contrast, the magnitude of native ascidian recruitment was negatively correlated with winter temperature (more recruitment in colder years) and the timing of native recruitment was unaffected. In manipulative laboratory experiments, two introduced compound ascidians grew faster than a native species, but only at temperatures near the maximum observed in summer. These data suggest that the greatest effects of climate change on biotic communities may be due to changing maximum and minimum temperatures rather than annual means. By giving introduced species an earlier start, and increasing the magnitude of their growth and recruitment relative to natives, global warming may facilitate a shift to dominance by nonnative species, accelerating the homogenization of the global biota. PMID:12422019

  11. Linking climate change and biological invasions: Ocean warming facilitates nonindigenous species invasions.

    PubMed

    Stachowicz, John J; Terwin, Jeffrey R; Whitlatch, Robert B; Osman, Richard W

    2002-11-26

    The spread of exotic species and climate change are among the most serious global environmental threats. Each independently causes considerable ecological damage, yet few data are available to assess whether changing climate might facilitate invasions by favoring introduced over native species. Here, we compare our long-term record of weekly sessile marine invertebrate recruitment with interannual variation in water temperature to assess the likely effect of climate change on the success and spread of introduced species. For the three most abundant introduced species of ascidian (sea squirt), the timing of the initiation of recruitment was strongly negatively correlated with winter water temperature, indicating that invaders arrived earlier in the season in years with warmer winters. Total recruitment of introduced species during the following summer also was positively correlated with winter water temperature. In contrast, the magnitude of native ascidian recruitment was negatively correlated with winter temperature (more recruitment in colder years) and the timing of native recruitment was unaffected. In manipulative laboratory experiments, two introduced compound ascidians grew faster than a native species, but only at temperatures near the maximum observed in summer. These data suggest that the greatest effects of climate change on biotic communities may be due to changing maximum and minimum temperatures rather than annual means. By giving introduced species an earlier start, and increasing the magnitude of their growth and recruitment relative to natives, global warming may facilitate a shift to dominance by nonnative species, accelerating the homogenization of the global biota.

  12. Tensile Forces Originating from Cancer Spheroids Facilitate Tumor Invasion

    PubMed Central

    Kopanska, Katarzyna S.; Alcheikh, Yara; Staneva, Ralitza; Vignjevic, Danijela; Betz, Timo

    2016-01-01

    The mechanical properties of tumors and the tumor environment provide important information for the progression and characterization of cancer. Tumors are surrounded by an extracellular matrix (ECM) dominated by collagen I. The geometrical and mechanical properties of the ECM play an important role for the initial step in the formation of metastasis, presented by the migration of malignant cells towards new settlements as well as the vascular and lymphatic system. The extent of this cell invasion into the ECM is a key medical marker for cancer prognosis. In vivo studies reveal an increased stiffness and different architecture of tumor tissue when compared to its healthy counterparts. The observed parallel collagen organization on the tumor border and radial arrangement at the invasion zone has raised the question about the mechanisms organizing these structures. Here we study the effect of contractile forces originated from model tumor spheroids embedded in a biomimetic collagen I matrix. We show that contractile forces act immediately after seeding and deform the ECM, thus leading to tensile radial forces within the matrix. Relaxation of this tension via cutting the collagen does reduce invasion, showing a mechanical relation between the tensile state of the ECM and invasion. In turn, these results suggest that tensile forces in the ECM facilitate invasion. Furthermore, simultaneous contraction of the ECM and tumor growth leads to the condensation and reorientation of the collagen at the spheroid’s surface. We propose a tension-based model to explain the collagen organization and the onset of invasion by forces originating from the tumor. PMID:27271249

  13. Tensile Forces Originating from Cancer Spheroids Facilitate Tumor Invasion.

    PubMed

    Kopanska, Katarzyna S; Alcheikh, Yara; Staneva, Ralitza; Vignjevic, Danijela; Betz, Timo

    2016-01-01

    The mechanical properties of tumors and the tumor environment provide important information for the progression and characterization of cancer. Tumors are surrounded by an extracellular matrix (ECM) dominated by collagen I. The geometrical and mechanical properties of the ECM play an important role for the initial step in the formation of metastasis, presented by the migration of malignant cells towards new settlements as well as the vascular and lymphatic system. The extent of this cell invasion into the ECM is a key medical marker for cancer prognosis. In vivo studies reveal an increased stiffness and different architecture of tumor tissue when compared to its healthy counterparts. The observed parallel collagen organization on the tumor border and radial arrangement at the invasion zone has raised the question about the mechanisms organizing these structures. Here we study the effect of contractile forces originated from model tumor spheroids embedded in a biomimetic collagen I matrix. We show that contractile forces act immediately after seeding and deform the ECM, thus leading to tensile radial forces within the matrix. Relaxation of this tension via cutting the collagen does reduce invasion, showing a mechanical relation between the tensile state of the ECM and invasion. In turn, these results suggest that tensile forces in the ECM facilitate invasion. Furthermore, simultaneous contraction of the ECM and tumor growth leads to the condensation and reorientation of the collagen at the spheroid's surface. We propose a tension-based model to explain the collagen organization and the onset of invasion by forces originating from the tumor. PMID:27271249

  14. Facilitation and competition among invasive plants: a field experiment with alligatorweed and water hyacinth.

    PubMed

    Wundrow, Emily J; Carrillo, Juli; Gabler, Christopher A; Horn, Katherine C; Siemann, Evan

    2012-01-01

    Ecosystems that are heavily invaded by an exotic species often contain abundant populations of other invasive species. This may reflect shared responses to a common factor, but may also reflect positive interactions among these exotic species. Armand Bayou (Pasadena, TX) is one such ecosystem where multiple species of invasive aquatic plants are common. We used this system to investigate whether presence of one exotic species made subsequent invasions by other exotic species more likely, less likely, or if it had no effect. We performed an experiment in which we selectively removed exotic rooted and/or floating aquatic plant species and tracked subsequent colonization and growth of native and invasive species. This allowed us to quantify how presence or absence of one plant functional group influenced the likelihood of successful invasion by members of the other functional group. We found that presence of alligatorweed (rooted plant) decreased establishment of new water hyacinth (free-floating plant) patches but increased growth of hyacinth in established patches, with an overall net positive effect on success of water hyacinth. Water hyacinth presence had no effect on establishment of alligatorweed but decreased growth of existing alligatorweed patches, with an overall net negative effect on success of alligatorweed. Moreover, observational data showed positive correlations between hyacinth and alligatorweed with hyacinth, on average, more abundant. The negative effect of hyacinth on alligatorweed growth implies competition, not strong mutual facilitation (invasional meltdown), is occurring in this system. Removal of hyacinth may increase alligatorweed invasion through release from competition. However, removal of alligatorweed may have more complex effects on hyacinth patch dynamics because there were strong opposing effects on establishment versus growth. The mix of positive and negative interactions between floating and rooted aquatic plants may influence local

  15. Facilitation and Competition among Invasive Plants: A Field Experiment with Alligatorweed and Water Hyacinth

    PubMed Central

    Wundrow, Emily J.; Carrillo, Juli; Gabler, Christopher A.; Horn, Katherine C.; Siemann, Evan

    2012-01-01

    Ecosystems that are heavily invaded by an exotic species often contain abundant populations of other invasive species. This may reflect shared responses to a common factor, but may also reflect positive interactions among these exotic species. Armand Bayou (Pasadena, TX) is one such ecosystem where multiple species of invasive aquatic plants are common. We used this system to investigate whether presence of one exotic species made subsequent invasions by other exotic species more likely, less likely, or if it had no effect. We performed an experiment in which we selectively removed exotic rooted and/or floating aquatic plant species and tracked subsequent colonization and growth of native and invasive species. This allowed us to quantify how presence or absence of one plant functional group influenced the likelihood of successful invasion by members of the other functional group. We found that presence of alligatorweed (rooted plant) decreased establishment of new water hyacinth (free-floating plant) patches but increased growth of hyacinth in established patches, with an overall net positive effect on success of water hyacinth. Water hyacinth presence had no effect on establishment of alligatorweed but decreased growth of existing alligatorweed patches, with an overall net negative effect on success of alligatorweed. Moreover, observational data showed positive correlations between hyacinth and alligatorweed with hyacinth, on average, more abundant. The negative effect of hyacinth on alligatorweed growth implies competition, not strong mutual facilitation (invasional meltdown), is occurring in this system. Removal of hyacinth may increase alligatorweed invasion through release from competition. However, removal of alligatorweed may have more complex effects on hyacinth patch dynamics because there were strong opposing effects on establishment versus growth. The mix of positive and negative interactions between floating and rooted aquatic plants may influence local

  16. Facilitate Insight by Non-Invasive Brain Stimulation

    PubMed Central

    Chi, Richard P.; Snyder, Allan W.

    2011-01-01

    Our experiences can blind us. Once we have learned to solve problems by one method, we often have difficulties in generating solutions involving a different kind of insight. Yet there is evidence that people with brain lesions are sometimes more resistant to this so-called mental set effect. This inspired us to investigate whether the mental set effect can be reduced by non-invasive brain stimulation. 60 healthy right-handed participants were asked to take an insight problem solving task while receiving transcranial direct current stimulation (tDCS) to the anterior temporal lobes (ATL). Only 20% of participants solved an insight problem with sham stimulation (control), whereas 3 times as many participants did so (p = 0.011) with cathodal stimulation (decreased excitability) of the left ATL together with anodal stimulation (increased excitability) of the right ATL. We found hemispheric differences in that a stimulation montage involving the opposite polarities did not facilitate performance. Our findings are consistent with the theory that inhibition to the left ATL can lead to a cognitive style that is less influenced by mental templates and that the right ATL may be associated with insight or novel meaning. Further studies including neurophysiological imaging are needed to elucidate the specific mechanisms leading to the enhancement. PMID:21311746

  17. Cane toads on cowpats: commercial livestock production facilitates toad invasion in tropical australia.

    PubMed

    González-Bernal, Edna; Greenlees, Matthew; Brown, Gregory P; Shine, Richard

    2012-01-01

    Habitat disturbance and the spread of invasive organisms are major threats to biodiversity, but the interactions between these two factors remain poorly understood in many systems. Grazing activities may facilitate the spread of invasive cane toads (Rhinella marina) through tropical Australia by providing year-round access to otherwise-seasonal resources. We quantified the cane toad's use of cowpats (feces piles) in the field, and conducted experimental trials to assess the potential role of cowpats as sources of prey, water, and warmth for toads. Our field surveys show that cane toads are found on or near cowpats more often than expected by chance. Field-enclosure experiments show that cowpats facilitate toad feeding by providing access to dung beetles. Cowpats also offer moist surfaces that can reduce dehydration rates of toads and are warmer than other nearby substrates. Livestock grazing is the primary form of land use over vast areas of Australia, and pastoral activities may have contributed substantially to the cane toad's successful invasion of that continent. PMID:23145158

  18. Biogenic disturbance determines invasion success in a subtidal soft-sediment system.

    PubMed

    Lohrer, Andrew M; Chiaroni, Luca D; Hewitt, Judi E; Thrush, Simon F

    2008-05-01

    Theoretically, disturbance and diversity can influence the success of invasive colonists if (1) resource limitation is a prime determinant of invasion success and (2) disturbance and diversity affect the availability of required resources. However, resource limitation is not of overriding importance in all systems, as exemplified by marine soft sediments, one of Earth's most widespread habitat types. Here, we tested the disturbance-invasion hypothesis in a marine soft-sediment system by altering rates of biogenic disturbance and tracking the natural colonization of plots by invasive species. Levels of sediment disturbance were controlled by manipulating densities of burrowing spatangoid urchins, the dominant biogenic sediment mixers in the system. Colonization success by two invasive species (a gobiid fish and a semelid bivalve) was greatest in plots with sediment disturbance rates < 500 cm(3) x m(-2) x d(-1), at the low end of the experimental disturbance gradient (0 to > 9000 cm(3) x m(-2) x d(-1)). Invasive colonization declined with increasing levels of sediment disturbance, counter to the disturbance-invasion hypothesis. Increased sediment disturbance by the urchins also reduced the richness and diversity of native macrofauna (particularly small, sedentary, surface feeders), though there was no evidence of increased availability of resources with increased disturbance that would have facilitated invasive colonization: sediment food resources (chlorophyll a and organic matter content) did not increase, and space and access to overlying water were not limited (low invertebrate abundance). Thus, our study revealed the importance of biogenic disturbance in promoting invasion resistance in a marine soft-sediment community, providing further evidence of the valuable role of bioturbation in soft-sediment systems (bioturbation also affects carbon processing, nutrient recycling, oxygen dynamics, benthic community structure, and so on.). Bioturbation rates are

  19. Temperature Tolerance and Stress Proteins as Mechanisms of Invasive Species Success

    PubMed Central

    Zerebecki, Robyn A.; Sorte, Cascade J. B.

    2011-01-01

    has facilitated the current success of invasive species and could lead to greater success of invasives than native species as global warming continues. PMID:21541309

  20. Repetition across successive sentences facilitates young children's word learning.

    PubMed

    Schwab, Jessica F; Lew-Williams, Casey

    2016-06-01

    Young children who hear more child-directed speech (CDS) tend to have larger vocabularies later in childhood, but the specific characteristics of CDS underlying this link are currently underspecified. The present study sought to elucidate how the structure of language input boosts learning by investigating whether repetition of object labels in successive sentences-a common feature of natural CDS-promotes young children's efficiency in learning new words. Using a looking-while-listening paradigm, 2-year-old children were taught the names of novel objects, with exposures either repeated across successive sentences or distributed throughout labeling episodes. Results showed successful learning only when label-object pairs had been repeated in blocks of successive sentences, suggesting that immediate opportunities to detect recurring structure facilitate young children's learning. These findings offer insight into how the information flow within CDS might influence vocabulary development, and we consider the findings alongside research showing the benefits of distributing information across time. (PsycINFO Database Record PMID:27148781

  1. Non-native grass invasion suppresses forest succession.

    PubMed

    Flory, S Luke; Clay, Keith

    2010-12-01

    Multiple factors can affect the process of forest succession including seed dispersal patterns, seedling survival, and environmental heterogeneity. A relatively understudied factor affecting the process of succession is invasions by non-native plants. Invasions can increase competition, alter abiotic conditions, and provide refuge for consumers. Functional traits of trees such as seed size and life history stage may mediate the effects of invasions on succession. We tested the effects of the forest invader Microstegium vimineum on planted and naturally regenerating trees in a multi-year field experiment. We established plots containing nine species of small- and large-seeded tree species planted as seeds or saplings, and experimentally added Microstegium to half of all plots. Over 3 years, Microstegium invasion had an overall negative effect on small-seeded species driven primarily by the effect on sweetgum, the most abundant small-seeded species, but did not affect large-seeded species such as hickory and oak species, which have more stored seed resources. Natural regeneration was over 400% greater in control than invaded plots for box elder, red maple, and spicebush, and box elder seedlings were 58% smaller in invaded plots. In contrast to the effects on tree seedlings, invasion did not affect tree sapling survival or growth. Microstegium may be directly reducing tree regeneration through competition. Invaded plots had greater overall herbaceous biomass in 2006 and 2008 and reduced light availability late in the growing season. Indirect effects may also be important. Invaded plots had 120% more thatch biomass, a physical barrier to seedling establishment, and significantly greater vole damage to tree saplings during 2006 and 2007. Our results show that two tree functional traits, seed size and life history stage, determined the effects of Microstegium on tree regeneration. Suppression of tree regeneration by Microstegium invasions may slow the rate of forest

  2. Environmental and biotic correlates to lionfish invasion success in Bahamian coral reefs.

    PubMed

    Anton, Andrea; Simpson, Michael S; Vu, Ivana

    2014-01-01

    Lionfish (Pterois volitans), venomous predators from the Indo-Pacific, are recent invaders of the Caribbean Basin and southeastern coast of North America. Quantification of invasive lionfish abundances, along with potentially important physical and biological environmental characteristics, permitted inferences about the invasion process of reefs on the island of San Salvador in the Bahamas. Environmental wave-exposure had a large influence on lionfish abundance, which was more than 20 and 120 times greater for density and biomass respectively at sheltered sites as compared with wave-exposed environments. Our measurements of topographic complexity of the reefs revealed that lionfish abundance was not driven by habitat rugosity. Lionfish abundance was not negatively affected by the abundance of large native predators (or large native groupers) and was also unrelated to the abundance of medium prey fishes (total length of 5-10 cm). These relationships suggest that (1) higher-energy environments may impose intrinsic resistance against lionfish invasion, (2) habitat complexity may not facilitate the lionfish invasion process, (3) predation or competition by native fishes may not provide biotic resistance against lionfish invasion, and (4) abundant prey fish might not facilitate lionfish invasion success. The relatively low biomass of large grouper on this island could explain our failure to detect suppression of lionfish abundance and we encourage continuing the preservation and restoration of potential lionfish predators in the Caribbean. In addition, energetic environments might exert direct or indirect resistance to the lionfish proliferation, providing native fish populations with essential refuges. PMID:25184250

  3. Environmental and Biotic Correlates to Lionfish Invasion Success in Bahamian Coral Reefs

    PubMed Central

    Anton, Andrea; Simpson, Michael S.; Vu, Ivana

    2014-01-01

    Lionfish (Pterois volitans), venomous predators from the Indo-Pacific, are recent invaders of the Caribbean Basin and southeastern coast of North America. Quantification of invasive lionfish abundances, along with potentially important physical and biological environmental characteristics, permitted inferences about the invasion process of reefs on the island of San Salvador in the Bahamas. Environmental wave-exposure had a large influence on lionfish abundance, which was more than 20 and 120 times greater for density and biomass respectively at sheltered sites as compared with wave-exposed environments. Our measurements of topographic complexity of the reefs revealed that lionfish abundance was not driven by habitat rugosity. Lionfish abundance was not negatively affected by the abundance of large native predators (or large native groupers) and was also unrelated to the abundance of medium prey fishes (total length of 5–10 cm). These relationships suggest that (1) higher-energy environments may impose intrinsic resistance against lionfish invasion, (2) habitat complexity may not facilitate the lionfish invasion process, (3) predation or competition by native fishes may not provide biotic resistance against lionfish invasion, and (4) abundant prey fish might not facilitate lionfish invasion success. The relatively low biomass of large grouper on this island could explain our failure to detect suppression of lionfish abundance and we encourage continuing the preservation and restoration of potential lionfish predators in the Caribbean. In addition, energetic environments might exert direct or indirect resistance to the lionfish proliferation, providing native fish populations with essential refuges. PMID:25184250

  4. Strong human association with plant invasion success for Trifolium introductions to New Zealand.

    PubMed

    Gravuer, Kelly; Sullivan, Jon J; Williams, Peter A; Duncan, Richard P

    2008-04-29

    It has proven difficult, when focused only on biological determinants, to explain why some plant species become naturalized in or invade new locations, whereas others fail. We analyzed the invasion of Trifolium (true clover) species into New Zealand, assessing a range of human, biogeographic, and biological influences at three key invasion stages: introduction, naturalization, and spread. We used sparse principal component analysis (SPCA) to define suites of related attributes and aggregated boosted trees to model relationships with invasion outcomes. Human and biogeographic attributes were strongly associated with success at all stages. Whereas biogeographic attributes, notably large native range, were consistently associated with success, different human factors appeared to favor success at different stages, such as presence in early trade/immigration hotspots (introduction), intentional large-scale planting (naturalization), and frequent presence as a seed contaminant (relative spread rate). Biological traits were less strongly associated with success for introduction and spread and little if at all for naturalization; we found that tall perennials with long flowering periods were more frequently selected for introduction, whereas species with extended flowering in New Zealand spread more rapidly. In addition to causal relationships, the importance of human factors may reflect indirect associations, including ecological traits associated with both human use and invasion. Nevertheless, our results highlight key roles that humans can play in facilitating plant invasion via two pathways: (i) commercial introduction leading to widespread planting and concomitant naturalization and spread and (ii) unintentional introduction and spread of species associated with human activities, such as seed contaminants.

  5. Hybridization can facilitate species invasions, even without enhancing local adaptation.

    PubMed

    Mesgaran, Mohsen B; Lewis, Mark A; Ades, Peter K; Donohue, Kathleen; Ohadi, Sara; Li, Chengjun; Cousens, Roger D

    2016-09-01

    The founding population in most new species introductions, or at the leading edge of an ongoing invasion, is likely to be small. Severe Allee effects-reductions in individual fitness at low population density-may then result in a failure of the species to colonize, even if the habitat could support a much larger population. Using a simulation model for plant populations that incorporates demography, mating systems, quantitative genetics, and pollinators, we show that Allee effects can potentially be overcome by transient hybridization with a resident species or an earlier colonizer. This mechanism does not require the invocation of adaptive changes usually attributed to invasions following hybridization. We verify our result in a case study of sequential invasions by two plant species where the outcrosser Cakile maritima has replaced an earlier, inbreeding, colonizer Cakile edentula (Brassicaceae). Observed historical rates of replacement are consistent with model predictions from hybrid-alleviated Allee effects in outcrossers, although other causes cannot be ruled out.

  6. Synergies between climate anomalies and hydrological modifications facilitate estuarine biotic invasions.

    PubMed

    Winder, Monika; Jassby, Alan D; Mac Nally, Ralph

    2011-08-01

    Environmental perturbation, climate change and international commerce are important drivers for biological invasions. Climate anomalies can further increase levels of habitat disturbance and act synergistically to elevate invasion risk. Herein, we use a historical data set from the upper San Francisco Estuary to provide the first empirical evidence for facilitation of invasions by climate extremes. Invasive zooplankton species did not become established in this estuary until the 1970s when increasing propagule pressure from Asia coincided with extended drought periods. Hydrological management exacerbated the effects of post-1960 droughts and reduced freshwater inflow even further, increasing drought severity and allowing unusually extreme salinity intrusions. Native zooplankton experienced unprecedented conditions of high salinity and intensified benthic grazing, and life history attributes of invasive zooplankton were advantageous enough during droughts to outcompete native species and colonise the system. Extreme climatic events can therefore act synergistically with environmental perturbation to facilitate the establishment of invasive species.

  7. INDIRECT FACILITATION OF AN ANURAN INVASION BY NON-NATIVE FISHES

    EPA Science Inventory

    Indirect trophic interactions are increasingly considered critical to the structure of biological communities but have received little attention in the process of invasion. We found that invasion of bullfrogs is facilitated by the presence of non-native fish, which indirectly inc...

  8. Hybridization can facilitate species invasions, even without enhancing local adaptation.

    PubMed

    Mesgaran, Mohsen B; Lewis, Mark A; Ades, Peter K; Donohue, Kathleen; Ohadi, Sara; Li, Chengjun; Cousens, Roger D

    2016-09-01

    The founding population in most new species introductions, or at the leading edge of an ongoing invasion, is likely to be small. Severe Allee effects-reductions in individual fitness at low population density-may then result in a failure of the species to colonize, even if the habitat could support a much larger population. Using a simulation model for plant populations that incorporates demography, mating systems, quantitative genetics, and pollinators, we show that Allee effects can potentially be overcome by transient hybridization with a resident species or an earlier colonizer. This mechanism does not require the invocation of adaptive changes usually attributed to invasions following hybridization. We verify our result in a case study of sequential invasions by two plant species where the outcrosser Cakile maritima has replaced an earlier, inbreeding, colonizer Cakile edentula (Brassicaceae). Observed historical rates of replacement are consistent with model predictions from hybrid-alleviated Allee effects in outcrossers, although other causes cannot be ruled out. PMID:27601582

  9. Reduced genetic variation and the success of an invasive species

    PubMed Central

    Tsutsui, Neil D.; Suarez, Andrew V.; Holway, David A.; Case, Ted J.

    2000-01-01

    Despite the severe ecological and economic damage caused by introduced species, factors that allow invaders to become successful often remain elusive. Of invasive taxa, ants are among the most widespread and harmful. Highly invasive ants are often unicolonial, forming supercolonies in which workers and queens mix freely among physically separate nests. By reducing costs associated with territoriality, unicolonial species can attain high worker densities, allowing them to achieve interspecific dominance. Here we examine the behavior and population genetics of the invasive Argentine ant (Linepithema humile) in its native and introduced ranges, and we provide a mechanism to explain its success as an invader. Using microsatellite markers, we show that a population bottleneck has reduced the genetic diversity of introduced populations. This loss is associated with reduced intraspecific aggression among spatially separate nests, and leads to the formation of interspecifically dominant supercolonies. In contrast, native populations are more genetically variable and exhibit pronounced intraspecific aggression. Although reductions in genetic diversity are generally considered detrimental, these findings provide an example of how a genetic bottleneck can lead to widespread ecological success. In addition, these results provide insights into the origin and evolution of unicoloniality, which is often considered a challenge to kin selection theory. PMID:10811892

  10. A successful avian invasion occupies a marginal ecological niche

    NASA Astrophysics Data System (ADS)

    Batalha, Helena R.; Ramos, Jaime A.; Cardoso, Gonçalo C.

    2013-05-01

    Biological invasions often threaten biodiversity, yet their ecological effects are unpredictable and in some cases may be neutral. Assessing potential interactions between invasive and native species is thus important to understand community functioning and prioritize conservation efforts. With this purpose, we compared the ecological niche and occurrence of a successful avian invader in SW Europe, the common waxbill (Estrildidae: Estrilda astrild), with those of co-occurring native passerine species. We found that common waxbills occupy a marginal niche relative to the community of native passerines, with a larger average ecological distance to the remaining species in the community compared to the native species amongst themselves, and a nearest-neighbour ecological distance identical to those of native species. Furthermore, ecological similarity did not predict co-occurrence of waxbills with other bird species. This is consistent with the invasion using a vacant niche in unsaturated communities, which is likely related to invading waxbills occupying partly human-modified habitats. Similar explanations may apply to other biological invasions of human-modified environments. Results also suggest that detrimental ecological effects due to interspecific competition with native passerines are unlikely. Notwithstanding, the ecological nearest-neighbour of common waxbills was the reed bunting (Emberiza schoeniclus), whose SW European subspecies are endangered, and may justify conservation attention regarding possible interactions between these two species.

  11. Warming can enhance invasion success through asymmetries in energetic performance.

    PubMed

    Penk, Marcin R; Jeschke, Jonathan M; Minchin, Dan; Donohue, Ian

    2016-03-01

    Both climate warming and biological invasions are prominent drivers of global environmental change and it is important to determine how they interact. However, beyond tolerance and reproductive thresholds, little is known about temperature dependence of invaders' performance, particularly in the light of competitive attributes of functionally similar native species. We used experimentally derived energy budgets and field temperature data to determine whether anticipated warming will asymmetrically affect the energy budgets of the globally invasive Ponto-Caspian mysid crustacean Hemimysis anomala and a functionally similar native competitor (Mysis salemaai) whose range is currently being invaded. In contrast to M. salemaai, which maintains a constant feeding rate with temperature leading to diminishing energy assimilation, we found that H. anomala increases its feeding rate with temperature in parallel with growing metabolic demand. This enabled the invader to maintain high energy assimilation rates, conferring substantially higher scope for growth compared to the native analogue at spring-to-autumn temperatures. Anticipated warming will likely exacerbate this energetic asymmetry and remove the winter overlap, which, given the seasonal limitation of mutually preferred prey, appears to underpin coexistence of the two species. These results indicate that temperature-dependent asymmetries in scope for growth between invaders and native analogues comprise an important mechanism determining invasion success under warming climates. They also highlight the importance of considering relevant spectra of ecological contexts in predicting successful invaders and their impacts under warming scenarios. PMID:26618450

  12. Rapid protein profiling facilitates surveillance of invasive mosquito species

    PubMed Central

    2014-01-01

    Background Invasive aedine mosquito species have become a major issue in many parts of the world as most of them are recognised vectors or potentially involved in transmission of pathogens. Surveillance of these mosquitoes (e.g. Ae. aegypti, Yellow fever mosquito, Aedes albopictus, Asian tiger mosquito) is mainly done by collecting eggs using ovitraps and by identification of the larvae hatched in the laboratory. In order to replace this challenging and laborious procedure, we have evaluated matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF MS) for easy and rapid species identification. Methods Individual protein profiles were generated using five eggs each of nine aedine species (Ae. aegypti, Ae. albopictus, Ae. atropalpus, Ae. cretinus, Ae. geniculatus, Ae. japonicus, Ae. koreicus, Ae. phoeniciae, Ae. triseriatus) from various geographical origins, and species-specific biomarker mass sets could be generated. A blinded validation using our reference data base for automated egg identification was performed. In addition, pools of 10 aedine eggs (132 two-species and 18 three-species pools) in different ratios were evaluated. Results Specific biomarker mass sets comprising 18 marker masses could be generated for eggs of nine container-inhabiting aedine species, including all the major invasive and indigenous species of Europe and North America. Two additional masses shared by all investigated aedine species are used as internal calibrators. Identification of single eggs was highly accurate (100% specificity, 98.75% sensitivity), and this method is also of value for the identification of species in pools of ten eggs. When mixing two or three species, all were identified in all pools in at least 2 or 1 of the 4 loaded replicates, respectively, if the “lesser abundant” species in the pool accounted for three or more eggs. Conclusions MALDI-TOF MS, which is widely applied for routine identification of microorganisms in clinical

  13. External morphology explains the success of biological invasions.

    PubMed

    Azzurro, Ernesto; Tuset, Victor M; Lombarte, Antoni; Maynou, Francesc; Simberloff, Daniel; Rodríguez-Pérez, Ana; Solé, Ricard V

    2014-11-01

    Biological invasions have become major players in the current biodiversity crisis, but realistic tools to predict which species will establish successful populations are still unavailable. Here we present a novel approach that requires only a morphometric characterisation of the species. Using fish invasions of the Mediterranean, we show that the abundance of non-indigenous fishes correlates with the location and relative size of occupied morphological space within the receiving pool of species. Those invaders that established abundant populations tended to be added outside or at the margins of the receiving morphospace, whereas non-indigenous species morphologically similar to resident ones failed to develop large populations or even to establish themselves, probably because the available ecological niches were already occupied. Accepting that morphology is a proxy for a species' ecological position in a community, our findings are consistent with ideas advanced since Darwin's naturalisation hypothesis and provide a new warning signal to identify invaders and to recognise vulnerable communities.

  14. External morphology explains the success of biological invasions.

    PubMed

    Azzurro, Ernesto; Tuset, Victor M; Lombarte, Antoni; Maynou, Francesc; Simberloff, Daniel; Rodríguez-Pérez, Ana; Solé, Ricard V

    2014-11-01

    Biological invasions have become major players in the current biodiversity crisis, but realistic tools to predict which species will establish successful populations are still unavailable. Here we present a novel approach that requires only a morphometric characterisation of the species. Using fish invasions of the Mediterranean, we show that the abundance of non-indigenous fishes correlates with the location and relative size of occupied morphological space within the receiving pool of species. Those invaders that established abundant populations tended to be added outside or at the margins of the receiving morphospace, whereas non-indigenous species morphologically similar to resident ones failed to develop large populations or even to establish themselves, probably because the available ecological niches were already occupied. Accepting that morphology is a proxy for a species' ecological position in a community, our findings are consistent with ideas advanced since Darwin's naturalisation hypothesis and provide a new warning signal to identify invaders and to recognise vulnerable communities. PMID:25227153

  15. Limitation and facilitation of one of the world's most invasive fish: an intercontinental comparison

    USGS Publications Warehouse

    Budy, Phaedra E.; Thiede, Gary P.; Lobón-Cerviá, Javier; Fernandez, Gustavo Gonzolez; McHugh, Peter; McIntosh, Angus; Vøllestad, Lief Asbjørn; Becares, Eloy; Jellyman, Phillip

    2013-01-01

    -dependent variation in determining invasion success. Overall our results indicate “growth plasticity across the life span” was important for facilitating invasion, and should be added to lists of factors characterizing successful invaders.

  16. Belowground advantages in construction cost facilitate a cryptic plant invasion.

    PubMed

    Caplan, Joshua S; Wheaton, Christine N; Mozdzer, Thomas J

    2014-04-30

    The energetic cost of plant organ construction is a functional trait that is useful for understanding carbon investment during growth (e.g. the resource acquisition vs. tissue longevity tradeoff), as well as in response to global change factors like elevated CO2 and N. Despite the enormous importance of roots and rhizomes in acquiring soil resources and responding to global change, construction costs have been studied almost exclusively in leaves. We sought to determine how construction costs of aboveground and belowground organs differed between native and introduced lineages of a geographically widely dispersed wetland plant species (Phragmites australis) under varying levels of CO2 and N. We grew plants under ambient and elevated atmospheric CO2, as well as under two levels of soil nitrogen. We determined construction costs for leaves, stems, rhizomes and roots, as well as for whole plants. Across all treatment conditions, the introduced lineage of Phragmites had a 4.3 % lower mean rhizome construction cost than the native. Whole-plant construction costs were also smaller for the introduced lineage, with the largest difference in sample means (3.3 %) occurring under ambient conditions. In having lower rhizome and plant-scale construction costs, the introduced lineage can recoup its investment in tissue construction more quickly, enabling it to generate additional biomass with the same energetic investment. Our results suggest that introduced Phragmites has had an advantageous tissue investment strategy under historic CO2 and N levels, which has facilitated key rhizome processes, such as clonal spread. We recommend that construction costs for multiple organ types be included in future studies of plant carbon economy, especially those investigating global change.

  17. Facilitating Participant Success: Teachers Experiencing Antarctica and the Arctic Program

    NASA Astrophysics Data System (ADS)

    Shipp, S. S.; Bruccoli, A.; Porter, M.; Meese, D.

    2003-12-01

    science content to solidify. This is illustrated by the changing emphasis of presentations. Presentations after the field season progress from being "experience" based to being "content" based as the teacher continues to develop understanding through interactions with researchers and teaching colleagues. The participants bring a wide array of skills to the program; rarely is one individual accomplished at every responsibility. Some participants are gifted speakers, others are talented writers, and others are exemplary mentors. The TEA Program has attempted to put into place support mechanisms to help build skills, and to leverage the strengths of the participants by providing opportunities for them to collaborate. Presentations are practiced within the TEA community before being presented at conferences. Classroom resources are identified, analyzed, and/or developed by teams of teachers in collaboration with curriculum writers at workshops. The mentoring requirement, considered the most challenging responsibility, is supported by bi-monthly conference calls that include several TEA teachers. Through these mechanisms, TEAs share successes, brainstorm solutions, and help each other with challenges. Facilitating the interaction and support of TEAs by each other is, perhaps, one of the strongest mechanisms for achieving success.

  18. An invasive species facilitates the recovery of salt marsh ecosystems on Cape Cod.

    PubMed

    Bertness, Mark D; Coverdale, Tyler C

    2013-09-01

    With global increases in human impacts, invasive species have become a major threat to ecosystems worldwide. While they have been traditionally viewed as harmful, invasive species may facilitate the restoration of degraded ecosystems outside their native ranges. In New England (USA) overfishing has depleted salt marsh predators, allowing the herbivorous crab Sesarma reticulatum to denude hundreds of hectares of low marsh. Here, using multiple site surveys and field caging experiments, we show that the subsequent invasion of green crabs, Carcinus maenas, into heavily burrowed marshes partially reverses decades of cordgrass die-off. By consuming Sesarma, eliciting a nonlethal escape response, and evicting Sesarma from burrows, Carcinus reduces Sesarma herbivory and promotes cordgrass recovery. These results suggest that invasive species can contribute to restoring degraded ecosystems and underscores the potential for invasive species to return ecological functions lost to human impacts. PMID:24279265

  19. An invasive species facilitates the recovery of salt marsh ecosystems on Cape Cod.

    PubMed

    Bertness, Mark D; Coverdale, Tyler C

    2013-09-01

    With global increases in human impacts, invasive species have become a major threat to ecosystems worldwide. While they have been traditionally viewed as harmful, invasive species may facilitate the restoration of degraded ecosystems outside their native ranges. In New England (USA) overfishing has depleted salt marsh predators, allowing the herbivorous crab Sesarma reticulatum to denude hundreds of hectares of low marsh. Here, using multiple site surveys and field caging experiments, we show that the subsequent invasion of green crabs, Carcinus maenas, into heavily burrowed marshes partially reverses decades of cordgrass die-off. By consuming Sesarma, eliciting a nonlethal escape response, and evicting Sesarma from burrows, Carcinus reduces Sesarma herbivory and promotes cordgrass recovery. These results suggest that invasive species can contribute to restoring degraded ecosystems and underscores the potential for invasive species to return ecological functions lost to human impacts.

  20. Geographical range, heat tolerance and invasion success in aquatic species

    PubMed Central

    Bates, Amanda E.; McKelvie, Catherine M.; Sorte, Cascade J. B.; Morley, Simon A.; Jones, Nicholas A. R.; Mondon, Julie A.; Bird, Tomas J.; Quinn, Gerry

    2013-01-01

    Species with broader geographical ranges are expected to be ecological generalists, while species with higher heat tolerances may be relatively competitive at more extreme and increasing temperatures. Thus, both traits are expected to relate to increased survival during transport to new regions of the globe, and once there, establishment and spread. Here, we explore these expectations using datasets of latitudinal range breadth and heat tolerance in freshwater and marine invertebrates and fishes. After accounting for the latitude and hemisphere of each species’ native range, we find that species introduced to freshwater systems have broader geographical ranges in comparison to native species. Moreover, introduced species are more heat tolerant than related native species collected from the same habitats. We further test for differences in range breadth and heat tolerance in relation to invasion success by comparing species that have established geographically restricted versus extensive introduced distributions. We find that geographical range size is positively related to invasion success in freshwater species only. However, heat tolerance is implicated as a trait correlated to widespread occurrence of introduced populations in both freshwater and marine systems. Our results emphasize the importance of formal risk assessments before moving heat tolerant species to novel locations. PMID:24266040

  1. Facilitating Successful Postsecondary Transitions for Students with Disabilities

    ERIC Educational Resources Information Center

    Joyce, Diana K.; Grapin, Sally

    2012-01-01

    Over the past decade, school psychologists' role in facilitating the transition from high school to college for students with disabilities has become increasingly complex. Practitioners are faced with the difficult task of navigating the conspicuous disconnect between disability eligibility criteria at the secondary and postsecondary levels…

  2. Indirect facilitation of an anuran invasion by non-native fishes

    USGS Publications Warehouse

    Adams, Michael J.; Pearl, Christopher A.; Bury, R. Bruce

    2003-01-01

    Positive interactions among non-native species could greatly exacerbate the problem of invasions, but are poorly studied and our knowledge of their occurrence is mostly limited to plant-pollinator and dispersal interactions. We found that invasion of bullfrogs is facilitated by the presence of co-evolved non-native fish, which increase tadpole survival by reducing predatory macroinvertebrate densities. Native dragonfly nymphs in Oregon, USA caused zero survival of bullfrog tadpoles in a replicated field experiment unless a non-native sunfish was present to reduce dragonfly density. This pattern was also evident in pond surveys where the best predictors of bullfrog abundance were the presence of non-native fish and bathymetry. This is the first experimental evidence of facilitation between two non-native vertebrates and supports the invasional meltdown hypothesis. Such positive interactions among non-native species have the potential to disrupt ecosystems by amplifying invasions, and our study shows they can occur via indirect mechanisms.

  3. Loss of P53 facilitates invasion and metastasis of prostate cancer cells.

    PubMed

    Wang, Yi; Zhang, Y X; Kong, C Z; Zhang, Z; Zhu, Y Y

    2013-12-01

    Prostate cancer is a lethal cancer for the invasion and metastasis in its earlier period. P53 is a tumor suppressor gene which plays a critical role on safeguarding the integrity of genome. However, loss of P53 facilitates or inhibits the invasion and metastasis of tumor is still suspended. In this study, we are going to explain whether loss of P53 affect the invasion and metastasis of prostate cancer cells. To explore whether loss of P53 influences the invasion and metastasis ability of prostate cancer cells, we first compared the invasion ability of si-P53 treated cells and control cells by wound healing, transwell assay, and adhesion assay. We next tested the activity of MMP-2, MMP-9, and MMP-14 by western blot and gelatin zymography. Moreover, we employed WB and IF to identify the EMT containing E-cad, N-cad, vimentin, etc. We also examined the expression of cortactin, cytoskeleton, and paxillin by immunofluorescence, and tested the expression of ERK and JNK by WB. Finally, we applied WB to detect the expression of FAK, Src, and the phosphorylation of them to elucidate the mechanism of si-P53 influencing invasion and metastasis. According to the inhibition rate of si-P53, we choose the optimized volume of si-P53. With the volume, we compare the invasion and metastasis ability of Du145 and si-P53 treated cells. We find si-P53 promotes the invasion and metastasis in prostate cancer cells, increases the expression and activity of MMP-2/9 and MMP-14. Also, si-P53 promotes EMT and cytoskeleton rearrangement. Further analyses explain that this effect is associated with FAK-Src signaling pathway. Loss of P53 promotes the invasion and metastasis ability of prostate cancer cells and the mechanism is correlated with FAK-Src signaling pathway. P53 is involved in the context of invasion and metastasis. PMID:23982184

  4. The more the better? The role of polyploidy in facilitating plant invasions

    PubMed Central

    te Beest, Mariska; Le Roux, Johannes J.; Richardson, David M.; Brysting, Anne K.; Suda, Jan; Kubešová, Magdalena; Pyšek, Petr

    2012-01-01

    Background Biological invasions are a major ecological and socio-economic problem in many parts of the world. Despite an explosion of research in recent decades, much remains to be understood about why some species become invasive whereas others do not. Recently, polyploidy (whole genome duplication) has been proposed as an important determinant of invasiveness in plants. Genome duplication has played a major role in plant evolution and can drastically alter a plant's genetic make-up, morphology, physiology and ecology within only one or a few generations. This may allow some polyploids to succeed in strongly fluctuating environments and/or effectively colonize new habitats and, thus, increase their potential to be invasive. Scope We synthesize current knowledge on the importance of polyploidy for the invasion (i.e. spread) of introduced plants. We first aim to elucidate general mechanisms that are involved in the success of polyploid plants and translate this to that of plant invaders. Secondly, we provide an overview of ploidal levels in selected invasive alien plants and explain how ploidy might have contributed to their success. Conclusions Polyploidy can be an important factor in species invasion success through a combination of (1) ‘pre-adaptation’, whereby polyploid lineages are predisposed to conditions in the new range and, therefore, have higher survival rates and fitness in the earliest establishment phase; and (2) the possibility for subsequent adaptation due to a larger genetic diversity that may assist the ‘evolution of invasiveness’. Alternatively, polyploidization may play an important role by (3) restoring sexual reproduction following hybridization or, conversely, (4) asexual reproduction in the absence of suitable mates. We, therefore, encourage invasion biologists to incorporate assessments of ploidy in their studies of invasive alien species. PMID:22040744

  5. A trematode parasite alters growth, feeding behavior, and demographic success of invasive rusty crayfish (Orconectes rusticus).

    PubMed

    Sargent, Lindsey W; Baldridge, Ashley K; Vega-Ross, Maraliz; Towle, Kevin M; Lodge, David M

    2014-07-01

    Nonindigenous species can cause major changes to community interactions and ecosystem processes. The strong impacts of these species are often attributed to their high demographic success. While the importance of enemy release in facilitating invasions has often been emphasized, few studies have addressed the role of parasites in the invasive range in controlling demographic success of potential invaders. Here we examine whether a trematode parasite (Microphallus spp.) can contribute to previously documented alternate states in the abundance of invasive rusty crayfish (Orconectes rusticus) in north temperate lakes in Wisconsin, USA. Microphallus infect O. rusticus after emerging from their first intermediate host, a hydrobiid snail. As previously documented, O. rusticus reduce densities of hydrobiid snails through direct predation and destruction of macrophyte habitat. Therefore, if Microphallus substantially reduce O. rusticus fitness, these parasites may reinforce a state of low crayfish abundance, and, at the other extreme, abundant crayfish may repress these parasites, reinforcing a state of high crayfish abundance. From samples collected from 109 sites in 16 lakes, we discovered (1) a positive relationship between crayfish infection intensity and hydrobiid snail abundance, (2) a negative relationship between parasite prevalence and crayfish abundance, and (3) a negative relationship between parasite prevalence and crayfish population growth. With experiments, we found that infection with Microphallus reduced foraging behavior and growth in O. rusticus, which may be the mechanisms responsible for the population reductions we observed. Overall results are consistent with the hypothesis that Microphallus contributes to alternate states in the abundance and impacts of O. rusticus.

  6. Facilitating Classroom Success for the Closed Head Injured Student.

    ERIC Educational Resources Information Center

    DePompei, Roberta; Blosser, Jean L.

    Intended for special educators and administrators, the paper addresses the educational implications of closed head injury in children. Characteristics of head injured students are noted, including previous successful experiences in social and academic settings, inconsistent performance patterns, and cognitive deficits which are present as in other…

  7. [Non-invasive transcutaneous spinal cord stimulation facilitates locomotor activity in decerebrated and spinal cats].

    PubMed

    Musienko, P E; Bogacheva, I N; Savochin, A A; Kilimnik, V A; Gorskiĭ, O V; Nikitin, O A; Gerasimenko, Ia P

    2013-08-01

    It is known that spinal neuronal networks activated by epidural electrical stimulation (EES) can produce the stepping EMG pattern and control the locomotor behavior. At present study we showed that non-invasive transcutaneous electrical spinal cord stimulation (tESCS) applied to the lumbar-sacral enlargement can facilitate the locomotor activity in decerebrated and spinal animals. The comparison of the motor responses evoked by EES vs tESCS showed that both methods produce the locomotor patterns with close properties and similar reflex mechanisms. The data obtained suggest that tESCS is an efficient approach for investigation of the locomotor control in acute and chronic experiments as well as facilitates of the locomotor abilities after spinal cord injury. Taking to account the non-invasivity and easement of tESCS, this approach could be further implemented in clinical practice for rehabilitation of the patient with spinal cord injury.

  8. Invasive Japanese beetles facilitate aggregation and injury by a native scarab pest of ripening fruits

    PubMed Central

    Hammons, Derrick L.; Kurtural, S. Kaan; Newman, Melissa C.; Potter, Daniel A.

    2009-01-01

    Invasive species' facilitation, or benefiting, of native species is rarely considered in biological invasion literature but could have serious economic consequences should a non-native herbivore facilitate injury by a native pest of high-value crops. Japanese beetle (JB), Popillia japonica, a polyphagous scarab, facilitates feeding by the obligate fruit-feeding native green June beetle (GJB), Cotinis nitida, by biting into intact grape berries that GJB, which has blunt spatulate mandibles, is otherwise unable to exploit. Here, we show JB further facilitates GJB by contaminating fruits with yeasts, and by creating infection courts for yeasts associated with GJB, that elicit volatiles exploited as aggregation kairomones by GJB. Traps baited with combinations of grapes and beetles were used to show that fruits injured by JB alone, or in combination with GJB, become highly attractive to both sexes of GJB. Such grapes emit high amounts of fermentation compounds compared with intact grapes. Beetle feeding on grape mash induced the same volatiles as addition of winemaker's yeast, and similar attraction of GJB in the field. Eight yeast species were isolated and identified from JB collected from grapevine foliage. Establishment and spread of JB throughout fruit-growing regions of the United States is likely to elevate the pest status of GJB and other pests of ripening fruits in vineyards and orchards. PMID:19234133

  9. Climate warming may facilitate invasion of the exotic shrub Lantana camara.

    PubMed

    Zhang, Qiaoying; Zhang, Yunchun; Peng, Shaolin; Zobel, Kristjan

    2014-01-01

    Plant species show different responses to the elevated temperatures that are resulting from global climate change, depending on their ecological and physiological characteristics. The highly invasive shrub Lantana camara occurs between the latitudes of 35 °N and 35 °S. According to current and future climate scenarios predicted by the CLIMEX model, climatically suitable areas for L. camara are projected to contract globally, despite expansions in some areas. The objective of this study was to test those predictions, using a pot experiment in which branch cuttings were grown at three different temperatures (22 °C, 26 °C and 30 °C). We hypothesized that warming would facilitate the invasiveness of L. camara. In response to rising temperatures, the total biomass of L. camara did increase. Plants allocated more biomass to stems and enlarged their leaves more at 26 °C and 30 °C, which promoted light capture and assimilation. They did not appear to be stressed by higher temperatures, in fact photosynthesis and assimilation were enhanced. Using lettuce (Lactuca sativa) as a receptor plant in a bioassay experiment, we also tested the phytotoxicity of L. camara leachate at different temperatures. All aqueous extracts from fresh leaves significantly inhibited the germination and seedling growth of lettuce, and the allelopathic effects became stronger with increasing temperature. Our results provide key evidence that elevated temperature led to significant increases in growth along with physiological and allelopathic effects, which together indicate that global warming facilitates the invasion of L. camara.

  10. Large-scale facilitation of a sessile community by an invasive habitat-forming snail

    NASA Astrophysics Data System (ADS)

    Thyrring, Jakob; Thomsen, Mads Solgaard; Wernberg, Thomas

    2013-12-01

    We provide an example of extensive facilitation of a sessile community throughout an invaded estuary by the invasive snail Batillaria australis. We show that B. australis greatly increases a limiting resource (attachment space) to a community of sessile organisms and estimate that a large part of the invaded estuary now contain ca. 50 times more sessile individuals associated with the invader than all native snails combined. We argue that native snails are unlikely to have been dramatically reduced by the invader, and we therefore suggest that the shell-attached sessile community, as a functional group, has benefitted significantly from this invasion. These results expand the current understanding of how invaded marine systems respond to habitat-forming invaders.

  11. Arbuscular mycorrhizal fungi facilitate the invasion of Solidago canadensis L. in southeastern China

    NASA Astrophysics Data System (ADS)

    Yang, Ruyi; Zhou, Gang; Zan, Shuting; Guo, Fuyu; Su, Nannan; Li, Jing

    2014-11-01

    The significance of arbuscular mycorrhizal fungi (AMF) in the process of plant invasion is still poorly understood. We hypothesize that invasive plants would change local AMF community structure in a way that would benefit themselves but confer less advantages to native plants, thus influencing the extent of plant interactions. An AMF spore community composed of five morphospecies of Glomus with equal density (initial AMF spore community, I-AMF) was constructed to test this hypothesis. The results showed that the invasive species, Solidago canadensis, significantly increased the relative abundance of G. geosperum and G. etunicatum (altered AMF spore community, A-AMF) compared to G. mosseae, which was a dominant morphospecies in the monoculture of native Kummerowia striata. The shift in AMF spore community composition driven by S. canadensis generated functional variation between I-AMF and A-AMF communities. For example, I-AMF increased biomass and nutrient uptake of K. striata in both monocultures and mixtures of K. striata and S. canadensis compared to A-AMF. In contrast, A-AMF significantly enhanced root nitrogen (N) acquisition of S. canadensis grown in mixture. Moreover, mycorrhizal-mediated 15N uptake provided direct evidence that I-AMF and A-AMF differed in their affinities with native and invading species. The non-significant effect of A-AMF on K. striata did not result from allelopathy as root exudates of S. canadensis exhibited positive effects on seed germination and biomass of K. striata under naturally occurring concentrations. When considered together, we found that A-AMF facilitated the invasion of S. canadensis through decreasing competitiveness of the native plant K. striata. The results supported our hypothesis and can be used to improve our understanding of an ecosystem-based perspective towards exotic plant invasion.

  12. Increases in both temperature means and extremes likely facilitate invasive herbivore outbreaks

    NASA Astrophysics Data System (ADS)

    Ju, Rui-Ting; Zhu, Hai-Yan; Gao, Lei; Zhou, Xu-Hui; Li, Bo

    2015-10-01

    Although increases in mean temperature (MT) and extreme high temperature (EHT) can greatly affect population dynamics of insects under global warming, how concurrent changes in both MT and EHT affect invasive species is largely unknown. We used four thermal regimes to simulate the increases in summer temperature and compared their effects on the life-history traits of three geographical populations (Chongqing, Wuhan and Shanghai) of an invasive insect, Corythucha ciliata, in China. The four thermal regimes were control (i.e., natural or ambient), an increase in MT (IMT), an increase in EHT, and a combination of IMT + EHT. We found that the three warming regimes significantly increased the developmental rate but did not affect the survival, sex ratio, longevity, or fecundity of C. ciliata. Consequently, the intrinsic rate of natural increase (rm) was enhanced and the number of days required for population doubling (t) was reduced by the warming regimes. The demographic parameters did not significantly differ among the three populations. These results indicate that population size of C. ciliata may be enhanced by increases in both temperature means and extremes. The increases in summer temperature associated with climate change, therefore, would likely facilitate population outbreaks of some thermophilic invasive insects.

  13. Increases in both temperature means and extremes likely facilitate invasive herbivore outbreaks.

    PubMed

    Ju, Rui-Ting; Zhu, Hai-Yan; Gao, Lei; Zhou, Xu-Hui; Li, Bo

    2015-10-27

    Although increases in mean temperature (MT) and extreme high temperature (EHT) can greatly affect population dynamics of insects under global warming, how concurrent changes in both MT and EHT affect invasive species is largely unknown. We used four thermal regimes to simulate the increases in summer temperature and compared their effects on the life-history traits of three geographical populations (Chongqing, Wuhan and Shanghai) of an invasive insect, Corythucha ciliata, in China. The four thermal regimes were control (i.e., natural or ambient), an increase in MT (IMT), an increase in EHT, and a combination of IMT + EHT. We found that the three warming regimes significantly increased the developmental rate but did not affect the survival, sex ratio, longevity, or fecundity of C. ciliata. Consequently, the intrinsic rate of natural increase (rm) was enhanced and the number of days required for population doubling (t) was reduced by the warming regimes. The demographic parameters did not significantly differ among the three populations. These results indicate that population size of C. ciliata may be enhanced by increases in both temperature means and extremes. The increases in summer temperature associated with climate change, therefore, would likely facilitate population outbreaks of some thermophilic invasive insects.

  14. Increases in both temperature means and extremes likely facilitate invasive herbivore outbreaks.

    PubMed

    Ju, Rui-Ting; Zhu, Hai-Yan; Gao, Lei; Zhou, Xu-Hui; Li, Bo

    2015-01-01

    Although increases in mean temperature (MT) and extreme high temperature (EHT) can greatly affect population dynamics of insects under global warming, how concurrent changes in both MT and EHT affect invasive species is largely unknown. We used four thermal regimes to simulate the increases in summer temperature and compared their effects on the life-history traits of three geographical populations (Chongqing, Wuhan and Shanghai) of an invasive insect, Corythucha ciliata, in China. The four thermal regimes were control (i.e., natural or ambient), an increase in MT (IMT), an increase in EHT, and a combination of IMT + EHT. We found that the three warming regimes significantly increased the developmental rate but did not affect the survival, sex ratio, longevity, or fecundity of C. ciliata. Consequently, the intrinsic rate of natural increase (rm) was enhanced and the number of days required for population doubling (t) was reduced by the warming regimes. The demographic parameters did not significantly differ among the three populations. These results indicate that population size of C. ciliata may be enhanced by increases in both temperature means and extremes. The increases in summer temperature associated with climate change, therefore, would likely facilitate population outbreaks of some thermophilic invasive insects. PMID:26502826

  15. Increases in both temperature means and extremes likely facilitate invasive herbivore outbreaks

    PubMed Central

    Ju, Rui-Ting; Zhu, Hai-Yan; Gao, Lei; Zhou, Xu-Hui; Li, Bo

    2015-01-01

    Although increases in mean temperature (MT) and extreme high temperature (EHT) can greatly affect population dynamics of insects under global warming, how concurrent changes in both MT and EHT affect invasive species is largely unknown. We used four thermal regimes to simulate the increases in summer temperature and compared their effects on the life-history traits of three geographical populations (Chongqing, Wuhan and Shanghai) of an invasive insect, Corythucha ciliata, in China. The four thermal regimes were control (i.e., natural or ambient), an increase in MT (IMT), an increase in EHT, and a combination of IMT + EHT. We found that the three warming regimes significantly increased the developmental rate but did not affect the survival, sex ratio, longevity, or fecundity of C. ciliata. Consequently, the intrinsic rate of natural increase (rm) was enhanced and the number of days required for population doubling (t) was reduced by the warming regimes. The demographic parameters did not significantly differ among the three populations. These results indicate that population size of C. ciliata may be enhanced by increases in both temperature means and extremes. The increases in summer temperature associated with climate change, therefore, would likely facilitate population outbreaks of some thermophilic invasive insects. PMID:26502826

  16. Interaction of species traits and environmental disturbance predicts invasion success of aquatic microorganisms.

    PubMed

    Mächler, Elvira; Altermatt, Florian

    2012-01-01

    Factors such as increased mobility of humans, global trade and climate change are affecting the range of many species, and cause large-scale translocations of species beyond their native range. Many introduced species have a strong negative influence on the new local environment and lead to high economic costs. There is a strong interest to understand why some species are successful in invading new environments and others not. Most of our understanding and generalizations thereof, however, are based on studies of plants and animals, and little is known on invasion processes of microorganisms. We conducted a microcosm experiment to understand factors promoting the success of biological invasions of aquatic microorganisms. In a controlled lab experiment, protist and rotifer species originally isolated in North America invaded into a natural, field-collected community of microorganisms of European origin. To identify the importance of environmental disturbances on invasion success, we either repeatedly disturbed the local patches, or kept them as undisturbed controls. We measured both short-term establishment and long-term invasion success, and correlated it with species-specific life-history traits. We found that environmental disturbances significantly affected invasion success. Depending on the invading species' identity, disturbances were either promoting or decreasing invasion success. The interaction between habitat disturbance and species identity was especially pronounced for long-term invasion success. Growth rate was the most important trait promoting invasion success, especially when the species invaded into a disturbed local community. We conclude that neither species traits nor environmental factors alone conclusively predict invasion success, but an integration of both of them is necessary.

  17. Interaction of Species Traits and Environmental Disturbance Predicts Invasion Success of Aquatic Microorganisms

    PubMed Central

    Mächler, Elvira; Altermatt, Florian

    2012-01-01

    Factors such as increased mobility of humans, global trade and climate change are affecting the range of many species, and cause large-scale translocations of species beyond their native range. Many introduced species have a strong negative influence on the new local environment and lead to high economic costs. There is a strong interest to understand why some species are successful in invading new environments and others not. Most of our understanding and generalizations thereof, however, are based on studies of plants and animals, and little is known on invasion processes of microorganisms. We conducted a microcosm experiment to understand factors promoting the success of biological invasions of aquatic microorganisms. In a controlled lab experiment, protist and rotifer species originally isolated in North America invaded into a natural, field-collected community of microorganisms of European origin. To identify the importance of environmental disturbances on invasion success, we either repeatedly disturbed the local patches, or kept them as undisturbed controls. We measured both short-term establishment and long-term invasion success, and correlated it with species-specific life-history traits. We found that environmental disturbances significantly affected invasion success. Depending on the invading species’ identity, disturbances were either promoting or decreasing invasion success. The interaction between habitat disturbance and species identity was especially pronounced for long-term invasion success. Growth rate was the most important trait promoting invasion success, especially when the species invaded into a disturbed local community. We conclude that neither species traits nor environmental factors alone conclusively predict invasion success, but an integration of both of them is necessary. PMID:23028985

  18. Climate Warming May Facilitate Invasion of the Exotic Shrub Lantana camara

    PubMed Central

    Zhang, Qiaoying; Zhang, Yunchun; Peng, Shaolin; Zobel, Kristjan

    2014-01-01

    Plant species show different responses to the elevated temperatures that are resulting from global climate change, depending on their ecological and physiological characteristics. The highly invasive shrub Lantana camara occurs between the latitudes of 35°N and 35°S. According to current and future climate scenarios predicted by the CLIMEX model, climatically suitable areas for L. camara are projected to contract globally, despite expansions in some areas. The objective of this study was to test those predictions, using a pot experiment in which branch cuttings were grown at three different temperatures (22°C, 26°C and 30°C). We hypothesized that warming would facilitate the invasiveness of L. camara. In response to rising temperatures, the total biomass of L. camara did increase. Plants allocated more biomass to stems and enlarged their leaves more at 26°C and 30°C, which promoted light capture and assimilation. They did not appear to be stressed by higher temperatures, in fact photosynthesis and assimilation were enhanced. Using lettuce (Lactuca sativa) as a receptor plant in a bioassay experiment, we also tested the phytotoxicity of L. camara leachate at different temperatures. All aqueous extracts from fresh leaves significantly inhibited the germination and seedling growth of lettuce, and the allelopathic effects became stronger with increasing temperature. Our results provide key evidence that elevated temperature led to significant increases in growth along with physiological and allelopathic effects, which together indicate that global warming facilitates the invasion of L. camara. PMID:25184224

  19. Whitebark pine facilitation at treeline: potential interactions for disruption by an invasive pathogen.

    PubMed

    Tomback, Diana F; Blakeslee, Sarah C; Wagner, Aaron C; Wunder, Michael B; Resler, Lynn M; Pyatt, Jill C; Diaz, Soledad

    2016-08-01

    In stressful environments, facilitation often aids plant establishment, but invasive plant pathogens may potentially disrupt these interactions. In many treeline communities in the northern Rocky Mountains of the U.S. and Canada, Pinus albicaulis, a stress-tolerant pine, initiates tree islands at higher frequencies than other conifers - that is, leads to leeward tree establishment more frequently. The facilitation provided by a solitary (isolated) P. albicaulis leading to tree island initiation may be important for different life-history stages for leeward conifers, but it is not known which life-history stages are influenced and protection provided. However, P. albicaulis mortality from the non-native pathogen Cronartium ribicola potentially disrupts these facilitative interactions, reducing tree island initiation. In two Rocky Mountain eastern slope study areas, we experimentally examined fundamental plant-plant interactions which might facilitate tree island formation: the protection offered by P. albicaulis to leeward seed and seedling life-history stages, and to leeward krummholz conifers. In the latter case, we simulated mortality from C. ribicola for windward P. albicaulis to determine whether loss of P. albicaulis from C. ribicola impacts leeward conifers. Relative to other common solitary conifers at treeline, solitary P. albicaulis had higher abundance. More seeds germinated in leeward rock microsites than in conifer or exposed microsites, but the odds of cotyledon seedling survival during the growing season were highest in P. albicaulis microsites. Planted seedling survival was low among all microsites examined. Simulating death of windward P. albicaulis by C. ribicola reduced shoot growth of leeward trees. Loss of P. albicaulis to exotic disease may limit facilitation interactions and conifer community development at treeline and potentially impede upward movement as climate warms. PMID:27551372

  20. Differential invasion success of salmonids in southern Chile: patterns and hypotheses

    USGS Publications Warehouse

    Arismendi, Ivan; Penaluna, Brooke E.; Dunham, Jason B.; García de Leaniz, Carlos; Soto, Doris; Fleming, Ian A.; Gomez-Uchidam, Daniel; Gajardo, Gonzalo; Vargas, Pamela V.; León-Muñoz, Jorge

    2014-01-01

    Biological invasions create complex ecological and societal issues worldwide. Most of the knowledge about invasions comes only from successful invaders, but less is known about which processes determine the differential success of invasions. In this review, we develop a framework to identify the main dimensions driving the success and failure of invaders, including human influences, characteristics of the invader, and biotic interactions. We apply this framework by contrasting hypotheses and available evidence to explain variability in invasion success for 12 salmonids introduced to Chile. The success of Oncorhynchus mykiss and Salmo trutta seems to be influenced by a context-specific combination of their phenotypic plasticity, low ecosystem resistance, and propagule pressure. These well-established invaders may limit the success of subsequently introduced salmonids, with the possible exception of O. tshawytscha, which has a short freshwater residency and limited spatial overlap with trout. Although propagule pressure is high for O. kisutch and S. salar due to their intensive use in aquaculture, their lack of success in Chile may be explained by environmental resistance, including earlier spawning times than in their native ranges, and interactions with previously established and resident Rainbow Trout. Other salmonids have also failed to establish, and they exhibit a suite of ecological traits, environmental resistance, and limited propagule pressure that are variably associated with their lack of success. Collectively, understanding how the various drivers of invasion success interact may explain the differential success of invaders and provide key guidance for managing both positive and negative outcomes associated with their presence.

  1. Successful management of a case of electrical storm due to invasive endocarditis.

    PubMed

    Hottkowitz, Christoph; Ammann, Peter; Kleger, Gian Reto; Künzli, Andreas; Hack, Dietrich; Rickli, Hans; Maeder, Micha T

    2012-01-01

    We present a 44-year-old man with invasive aortic and tricuspid valve endocarditis complicated by electrical storm, which was immediately diagnosed and successfully treated due to the patient's telemetry electrocardiogram (ECG). This case highlights a rare but potentially fatal complication in patients with invasive endocarditis and the need for very careful clinical evaluation and monitoring of these patients.

  2. Creating a Successful Citizen Science Model to Detect and Report Invasive Species

    ERIC Educational Resources Information Center

    Gallo, Travis; Waitt, Damon

    2011-01-01

    The Invaders of Texas program is a successful citizen science program in which volunteers survey and monitor invasive plants throughout Texas. Invasive plants are being introduced at alarming rates, and our limited knowledge about their distribution is a major cause for concern. The Invaders of Texas program trains citizen scientists to detect the…

  3. Intraguild predation and successful invasion by introduced ladybird beetles.

    PubMed

    Snyder, William E; Clevenger, Garrett M; Eigenbrode, Sanford D

    2004-08-01

    Introductions of two ladybird beetle (Coleoptera: Coccinellidae) species, Coccinella septempunctata and Harmonia axyridis, into North America for aphid biocontrol have been followed by declines in native species. We examined intraguild predation (IGP) between larvae of these two exotic species and larvae of the two most abundant native coccinellids in eastern Washington State, C. transversoguttata and Hippodamia convergens. In pairings between the two native species in laboratory microcosms containing pea ( Pisum sativum) plants, neither native had a clear advantage over the other in IGP. When the natives were paired with either Harmonia axyridis or C. septempunctata, the natives were more frequently the victims than perpetrators of IGP. In contrast, in pairings between the exotic species, neither had an IGP advantage, although overall rates of IGP between these two species were very high. Adding alternative prey (aphids) to microcosms did not alter the frequency and patterns of relative IGP among the coccinellid species. In observations of encounters between larvae, the introduced H. axyridis frequently survived multiple encounters with the native C. transversoguttata, whereas the native rarely survived a single encounter with H. axyridis. Our results suggest that larvae of the native species face increased IGP following invasion by C. septempunctata and H. axyridis, which may be contributing to the speed with which these exotic ladybird beetles displace the natives following invasion.

  4. Success, failure, and spreading speeds for invasions on spatial gradients.

    PubMed

    Li, Bingtuan; Fagan, William F; Meyer, Kimberly I

    2015-01-01

    We study a model that describes the spatial spread of a species along a habitat gradient on which the species' growth increases. Mathematical analysis is provided to determine the spreading dynamics of the model. We demonstrate that the species may succeed or fail in local invasion depending on the species' growth function and dispersal kernel. We delineate the conditions under which a spreading species may be stopped by poor quality habitat, and demonstrate how a species can escape a region of poor quality habitat by climbing a resource gradient to good quality habitat where it spreads at a constant spreading speed. We show that dispersal may take the species from a good quality region to a poor quality region where the species becomes extinct. We also provide formulas for spreading speeds for the model that are determined by the dispersal kernel and linearized growth rates in both directions.

  5. Regime shift by an exotic nitrogen-fixing shrub mediates plant facilitation in primary succession.

    PubMed

    Stinca, Adriano; Chirico, Giovanni Battista; Incerti, Guido; Bonanomi, Giuliano

    2015-01-01

    Ecosystem invasion by non-native, nitrogen-fixing species is a global phenomenon with serious ecological consequences. However, in the Mediterranean basin few studies addressed the impact of invasion by nitrogen-fixing shrubs on soil quality and hydrological properties at local scale, and the possible effects on succession dynamics and ecosystem invasibility by further species. In this multidisciplinary study we investigated the impact of Genista aetnensis (Biv.) DC., an exotic nitrogen-fixing shrub, on the Vesuvius Grand Cone (Southern Italy). Specifically, we tested the hypotheses that the invasion of G. aetnensis has a significant impact on soil quality, soil hydrological regime, local microclimate and plant community structure, and that its impact increases during the plant ontogenetic cycle. We showed that G. aetnensis, in a relatively short time-span (i.e. ~ 40 years), has been able to build-up an island of fertility under its canopy, by accumulating considerable stocks of C, N, and P in the soil, and by also improving the soil hydrological properties. Moreover, G. aetnensis mitigates the daily range of soil temperature, reducing the exposure of coexisting plants to extremely high temperatures and water loss by soil evaporation, particularly during the growing season. Such amelioration of soil quality, coupled with the mitigation of below-canopy microclimatic conditions, has enhanced plant colonization of the barren Grand Cone slopes, by both herbaceous and woody species. These results suggest that the invasion of G. aetnensis could eventually drive to the spread of other, more resource-demanding exotic species, promoting alternative successional trajectories that may dramatically affect the local landscape. Our study is the first record of the invasion of G. aetnensis, an additional example of the regime shifts driven by N-fixing shrubs in Mediterranean region. Further studies are needed to identity specific management practices that can limit the spread and

  6. Regime shift by an exotic nitrogen-fixing shrub mediates plant facilitation in primary succession.

    PubMed

    Stinca, Adriano; Chirico, Giovanni Battista; Incerti, Guido; Bonanomi, Giuliano

    2015-01-01

    Ecosystem invasion by non-native, nitrogen-fixing species is a global phenomenon with serious ecological consequences. However, in the Mediterranean basin few studies addressed the impact of invasion by nitrogen-fixing shrubs on soil quality and hydrological properties at local scale, and the possible effects on succession dynamics and ecosystem invasibility by further species. In this multidisciplinary study we investigated the impact of Genista aetnensis (Biv.) DC., an exotic nitrogen-fixing shrub, on the Vesuvius Grand Cone (Southern Italy). Specifically, we tested the hypotheses that the invasion of G. aetnensis has a significant impact on soil quality, soil hydrological regime, local microclimate and plant community structure, and that its impact increases during the plant ontogenetic cycle. We showed that G. aetnensis, in a relatively short time-span (i.e. ~ 40 years), has been able to build-up an island of fertility under its canopy, by accumulating considerable stocks of C, N, and P in the soil, and by also improving the soil hydrological properties. Moreover, G. aetnensis mitigates the daily range of soil temperature, reducing the exposure of coexisting plants to extremely high temperatures and water loss by soil evaporation, particularly during the growing season. Such amelioration of soil quality, coupled with the mitigation of below-canopy microclimatic conditions, has enhanced plant colonization of the barren Grand Cone slopes, by both herbaceous and woody species. These results suggest that the invasion of G. aetnensis could eventually drive to the spread of other, more resource-demanding exotic species, promoting alternative successional trajectories that may dramatically affect the local landscape. Our study is the first record of the invasion of G. aetnensis, an additional example of the regime shifts driven by N-fixing shrubs in Mediterranean region. Further studies are needed to identity specific management practices that can limit the spread and

  7. Regime Shift by an Exotic Nitrogen-Fixing Shrub Mediates Plant Facilitation in Primary Succession

    PubMed Central

    Stinca, Adriano; Chirico, Giovanni Battista; Incerti, Guido; Bonanomi, Giuliano

    2015-01-01

    Ecosystem invasion by non-native, nitrogen-fixing species is a global phenomenon with serious ecological consequences. However, in the Mediterranean basin few studies addressed the impact of invasion by nitrogen-fixing shrubs on soil quality and hydrological properties at local scale, and the possible effects on succession dynamics and ecosystem invasibility by further species. In this multidisciplinary study we investigated the impact of Genista aetnensis (Biv.) DC., an exotic nitrogen-fixing shrub, on the Vesuvius Grand Cone (Southern Italy). Specifically, we tested the hypotheses that the invasion of G. aetnensis has a significant impact on soil quality, soil hydrological regime, local microclimate and plant community structure, and that its impact increases during the plant ontogenetic cycle. We showed that G. aetnensis, in a relatively short time-span (i.e. ~ 40 years), has been able to build-up an island of fertility under its canopy, by accumulating considerable stocks of C, N, and P in the soil, and by also improving the soil hydrological properties. Moreover, G. aetnensis mitigates the daily range of soil temperature, reducing the exposure of coexisting plants to extremely high temperatures and water loss by soil evaporation, particularly during the growing season. Such amelioration of soil quality, coupled with the mitigation of below-canopy microclimatic conditions, has enhanced plant colonization of the barren Grand Cone slopes, by both herbaceous and woody species. These results suggest that the invasion of G. aetnensis could eventually drive to the spread of other, more resource-demanding exotic species, promoting alternative successional trajectories that may dramatically affect the local landscape. Our study is the first record of the invasion of G. aetnensis, an additional example of the regime shifts driven by N-fixing shrubs in Mediterranean region. Further studies are needed to identity specific management practices that can limit the spread and

  8. Invasive maxillary sinus aspergillosis: A case report successfully treated with voriconazole and surgical debridement

    PubMed Central

    Redondo-González, Luis-Miguel; Verrier-Hernández, Alberto

    2014-01-01

    Introduction: Invasive aspergillosis of the paranasal sinuses is a rare disease and often misdiagnosed; however, its incidence has seen substancial growth over the past 2 decades. Definitive diagnosis of these lesions is based on histological examination and fungal culture. Case Report: An 81-year-old woman with a history of pain in the left maxillary region is presented. The diagnosis was invasive maxillary aspergillosis in immunocompetent patient, which was successfully treated with voriconazole and surgical debridement. Possible clinical manifestations, diagnostic imaging techniques and treatment used are discussed. Since the introduction of voriconazole, there have been several reports of patients with invasive aspergillosis who responded to treatment with this new antifungal agent. Conclusions: We report the importance of early diagnosis and selection of an appropriate antifungal agent to achieve a successful treatment. Key words:Invasive aspergillosis, voriconazole, fungal sinusitis, antifungal agent, open sinus surgery. PMID:25593673

  9. Long-distance dispersal of the gypsy moth (Lepidoptera: Lymantriidae) facilitated its initial invasion of Wisconsin.

    PubMed

    Tobin, Patrick C; Blackburn, Laura M

    2008-02-01

    Gypsy moth (Lymantria dispar L.) spread is dominated by stratified dispersal, and, although spread rates are variable in space and time, the gypsy moth has invaded Wisconsin at a consistently higher rate than in other regions. Allee effects, which act on low-density populations ahead of the moving population that contribute to gypsy moth spread, have also been observed to be consistently weaker in Wisconsin. Because a major cause of an Allee effect in the gypsy moth is mate-finding failure at low densities, supplementing low-density populations with immigrants that arrive through dispersal may facilitate establishment and consequent spread. We used local indicator of spatial autocorrelation methods to examine space-time gypsy moth monitoring data from 1996 to 2006 and identify isolated, low-density colonies that arrived through dispersal. We measured the distance of these colonies from the moving population front to show that long-distance dispersal was markedly present in earlier years when Wisconsin was still mainly uninfested. Recently, however, immigrants arriving through long-distance dispersal may no longer be detected because instead of invading uninfested areas, they are now supplementing high-density colonies. In contrast, we observed no temporal pattern in the distance between low-density colonies and the population front in West Virginia and Virginia. We submit that long-distance dispersal, perhaps facilitated through meteorological mechanisms, played an important role in the spread dynamics of the initial Wisconsin gypsy moth invasion, but it currently plays a lesser role because the portion of Wisconsin most susceptible to long-distance immigrants from alternate sources is now heavily infested.

  10. Inherent phenotypic plasticity facilitates progression of head and neck cancer: Endotheliod characteristics enable angiogenesis and invasion

    SciTech Connect

    Tong, Meng; Han, Byungdo B.; Holpuch, Andrew S.; Pei, Ping; He, Lingli; Mallery, Susan R.

    2013-04-15

    subpopulations are highly responsive to TGF- β1, VEGF and endostatin. ► TGF-β1 facilitates cadherin switching and augments invasiveness of HNSCC subpopulations.

  11. Different Traits Determine Introduction, Naturalization and Invasion Success In Woody Plants: Proteaceae as a Test Case

    PubMed Central

    Moodley, Desika; Geerts, Sjirk; Richardson, David M.; Wilson, John R. U.

    2013-01-01

    A major aim of invasion ecology is to identify characteristics of successful invaders. However, most plant groups studied in detail (e.g. pines and acacias) have a high percentage of invasive taxa. Here we examine the global introduction history and invasion ecology of Proteaceae—a large plant family with many taxa that have been widely disseminated by humans, but with few known invaders. To do this we compiled a global list of species and used boosted regression tree models to assess which factors are important in determining the status of a species (not introduced, introduced, naturalized or invasive). At least 402 of 1674 known species (24%) have been moved by humans out of their native ranges, 58 species (14%) have become naturalized but not invasive, and 8 species (2%) are invasive. The probability of naturalization was greatest for species with large native ranges, low susceptibility to Phytophthora root-rot fungus, large mammal-dispersed seeds, and with the capacity to resprout. The probability of naturalized species becoming invasive was greatest for species with large native ranges, those used as barrier plants, tall species, species with small seeds, and serotinous species. The traits driving invasiveness of Proteaceae were similar to those for acacias and pines. However, while some traits showed a consistent influence at introduction, naturalization and invasion, others appear to be influential at one stage only, and some have contrasting effects at different stages. Trait-based analyses therefore need to consider different invasion stages separately. On their own, these observations provide little predictive power for risk assessment, but when the causative mechanisms are understood (e.g. Phytophthora susceptibility) they provide valuable insights. As such there is considerable value in seeking the correlates and mechanisms underlying invasions for particular taxonomic or functional groups. PMID:24086442

  12. Different traits determine introduction, naturalization and invasion success in woody plants: Proteaceae as a test case.

    PubMed

    Moodley, Desika; Geerts, Sjirk; Richardson, David M; Wilson, John R U

    2013-01-01

    A major aim of invasion ecology is to identify characteristics of successful invaders. However, most plant groups studied in detail (e.g. pines and acacias) have a high percentage of invasive taxa. Here we examine the global introduction history and invasion ecology of Proteaceae--a large plant family with many taxa that have been widely disseminated by humans, but with few known invaders. To do this we compiled a global list of species and used boosted regression tree models to assess which factors are important in determining the status of a species (not introduced, introduced, naturalized or invasive). At least 402 of 1674 known species (24%) have been moved by humans out of their native ranges, 58 species (14%) have become naturalized but not invasive, and 8 species (2%) are invasive. The probability of naturalization was greatest for species with large native ranges, low susceptibility to Phytophthora root-rot fungus, large mammal-dispersed seeds, and with the capacity to resprout. The probability of naturalized species becoming invasive was greatest for species with large native ranges, those used as barrier plants, tall species, species with small seeds, and serotinous species. The traits driving invasiveness of Proteaceae were similar to those for acacias and pines. However, while some traits showed a consistent influence at introduction, naturalization and invasion, others appear to be influential at one stage only, and some have contrasting effects at different stages. Trait-based analyses therefore need to consider different invasion stages separately. On their own, these observations provide little predictive power for risk assessment, but when the causative mechanisms are understood (e.g. Phytophthora susceptibility) they provide valuable insights. As such there is considerable value in seeking the correlates and mechanisms underlying invasions for particular taxonomic or functional groups.

  13. Reductions in native grass biomass associated with drought facilitates the invasion of an exotic grass into a model grassland system.

    PubMed

    Manea, Anthony; Sloane, Daniel R; Leishman, Michelle R

    2016-05-01

    The invasion success of exotic plant species is often dependent on resource availability. Aspects of climate change such as rising atmospheric CO2 concentration and extreme climatic events will directly and indirectly alter resource availability in ecological communities. Understanding how these climate change-associated changes in resource availability will interact with one another to influence the invasion success of exotic plant species is complex. The aim of the study was to assess the establishment success of an invasive exotic species in response to climate change-associated changes in resource availability (CO2 levels and soil water availability) as a result of extreme drought. We grew grassland mesocosms consisting of four co-occurring native grass species common to the Cumberland Plain Woodland of western Sydney, Australia, under ambient and elevated CO2 levels and subjected them to an extreme drought treatment. We then added seeds of a highly invasive C3 grass, Ehrharta erecta, and assessed its establishment success (biomass production and reproductive output). We found that reduced biomass production of the native grasses in response to the extreme drought treatment enhanced the establishment success of E. erecta by creating resource pulses in light and space. Surprisingly, CO2 level did not affect the establishment success of E. erecta. Our results suggest that the invasion risk of grasslands in the future may be coupled to soil water availability and the subsequent response of resident native vegetation therefore making it strongly context- dependent. PMID:26780256

  14. Does greater thermal plasticity facilitate range expansion of an invasive terrestrial anuran into higher latitudes?

    PubMed Central

    Winwood-Smith, Hugh S.; Alton, Lesley A.; Franklin, Craig E.; White, Craig R.

    2015-01-01

    Temperature has pervasive effects on physiological processes and is critical in setting species distribution limits. Since invading Australia, cane toads have spread rapidly across low latitudes, but slowly into higher latitudes. Low temperature is the likely factor limiting high-latitude advancement. Several previous attempts have been made to predict future cane toad distributions in Australia, but understanding the potential contribution of phenotypic plasticity and adaptation to future range expansion remains challenging. Previous research demonstrates the considerable thermal metabolic plasticity of the cane toad, but suggests limited thermal plasticity of locomotor performance. Additionally, the oxygen-limited thermal tolerance hypothesis predicts that reduced aerobic scope sets thermal limits for ectotherm performance. Metabolic plasticity, locomotor performance and aerobic scope are therefore predicted targets of natural selection as cane toads invade colder regions. We measured these traits at temperatures of 10, 15, 22.5 and 30°C in low- and high-latitude toads acclimated to 15 and 30°C, to test the hypothesis that cane toads have adapted to cooler temperatures. High-latitude toads show increased metabolic plasticity and higher resting metabolic rates at lower temperatures. Burst locomotor performance was worse for high-latitude toads. Other traits showed no regional differences. We conclude that increased metabolic plasticity may facilitate invasion into higher latitudes by maintaining critical physiological functions at lower temperatures. PMID:27293695

  15. Does greater thermal plasticity facilitate range expansion of an invasive terrestrial anuran into higher latitudes?

    PubMed

    Winwood-Smith, Hugh S; Alton, Lesley A; Franklin, Craig E; White, Craig R

    2015-01-01

    Temperature has pervasive effects on physiological processes and is critical in setting species distribution limits. Since invading Australia, cane toads have spread rapidly across low latitudes, but slowly into higher latitudes. Low temperature is the likely factor limiting high-latitude advancement. Several previous attempts have been made to predict future cane toad distributions in Australia, but understanding the potential contribution of phenotypic plasticity and adaptation to future range expansion remains challenging. Previous research demonstrates the considerable thermal metabolic plasticity of the cane toad, but suggests limited thermal plasticity of locomotor performance. Additionally, the oxygen-limited thermal tolerance hypothesis predicts that reduced aerobic scope sets thermal limits for ectotherm performance. Metabolic plasticity, locomotor performance and aerobic scope are therefore predicted targets of natural selection as cane toads invade colder regions. We measured these traits at temperatures of 10, 15, 22.5 and 30°C in low- and high-latitude toads acclimated to 15 and 30°C, to test the hypothesis that cane toads have adapted to cooler temperatures. High-latitude toads show increased metabolic plasticity and higher resting metabolic rates at lower temperatures. Burst locomotor performance was worse for high-latitude toads. Other traits showed no regional differences. We conclude that increased metabolic plasticity may facilitate invasion into higher latitudes by maintaining critical physiological functions at lower temperatures.

  16. Massively parallel sequencing and analysis of expressed sequence tags in a successful invasive plant

    PubMed Central

    Prentis, Peter J.; Woolfit, Megan; Thomas-Hall, Skye R.; Ortiz-Barrientos, Daniel; Pavasovic, Ana; Lowe, Andrew J.; Schenk, Peer M.

    2010-01-01

    Background Invasive species pose a significant threat to global economies, agriculture and biodiversity. Despite progress towards understanding the ecological factors associated with plant invasions, limited genomic resources have made it difficult to elucidate the evolutionary and genetic factors responsible for invasiveness. This study presents the first expressed sequence tag (EST) collection for Senecio madagascariensis, a globally invasive plant species. Methods We used pyrosequencing of one normalized and two subtractive libraries, derived from one native and one invasive population, to generate an EST collection. ESTs were assembled into contigs, annotated by BLAST comparison with the NCBI non-redundant protein database and assigned gene ontology (GO) terms from the Plant GO Slim ontologies. Key Results Assembly of the 221 746 sequence reads resulted in 12 442 contigs. Over 50 % (6183) of 12 442 contigs showed significant homology to proteins in the NCBI database, representing approx. 4800 independent transcripts. The molecular transducer GO term was significantly over-represented in the native (South African) subtractive library compared with the invasive (Australian) library. Based on NCBI BLAST hits and literature searches, 40 % of the molecular transducer genes identified in the South African subtractive library are likely to be involved in response to biotic stimuli, such as fungal, bacterial and viral pathogens. Conclusions This EST collection is the first representation of the S. madagascariensis transcriptome and provides an important resource for the discovery of candidate genes associated with plant invasiveness. The over-representation of molecular transducer genes associated with defence responses in the native subtractive library provides preliminary support for aspects of the enemy release and evolution of increased competitive ability hypotheses in this successful invasive. This study highlights the contribution of next-generation sequencing

  17. Dual-goal facilitation in Wason's 2-4-6 task: what mediates successful rule discovery?

    PubMed

    Gale, Maggie; Ball, Linden J

    2006-05-01

    The standard 2-4-6 task requires discovery of a single rule and produces success rates of about 20%, whereas the dual-goal (DG) version requests discovery of two complementary rules and elevates success to over 60%. The experiment examined two explanations of DG superiority: Evans' (1989) positivity-bias account, and Wharton, Cheng, and Wickens' (1993) goal-complementarity theory. Two DG conditions were employed that varied the linguistic labelling of rules (either positively labelled Dax vs. Med, or mixed-valence "fits" vs. "does not fit"). Solution-success results supported the goal-complementarity theory since facilitation arose in both DG conditions relative to single-goal tasks, irrespective of the linguistic labelling of hypotheses. DG instructions also altered quantitative and qualitative aspects of hypothesis-testing behaviour, and analyses revealed the novel result that the production of at least a single descending triple mediates between DG instructions and task success. We propose that the identification of an appropriate contrast class that delimits the scope of complementary rules may be facilitated through the generation of a descending instance. Overall, our findings can best be accommodated by Oaksford and Chater's (1994) iterative counterfactual model of hypotheses testing, which can readily subsume key elements of the goal-complementarity theory. PMID:16608752

  18. Propagule size and dispersal costs mediate establishment success of an invasive species.

    PubMed

    Lange, Rolanda; Marshall, Dustin J

    2016-03-01

    Bio-invasions depend on the number and frequency of invaders arriving in new habitats. Yet, as is often the case, it is not only quantity that counts, but also quality. The process of dispersal can change disperser quality and establishment success. Invasions are a form of extra-range dispersal, so that invaders often experience changes in quality through dispersal. To study effects of dispersal on invader quality, and its interactions with quantity on invasion success, we manipulated both in a field experiment using an invasive marine invertebrate. Establishment success increased with the number of individuals arriving in a new habitat. Prolonged larval durations--our manipulation of prolonged dispersal--decreased individual quality and establishment success. Groups of invaders with prolonged larval durations contributed only a third of the offspring relative to invaders that settled immediately. We also found an interaction between the quality and quantity of invaders on individual growth: only within high-quality cohorts did individuals experience density-dependent effects on growth. Our findings highlight that dispersal not only affects the quantity of invaders arriving in a new habitat but also their quality, and both mediate establishment success. PMID:27197384

  19. Propagule size and dispersal costs mediate establishment success of an invasive species.

    PubMed

    Lange, Rolanda; Marshall, Dustin J

    2016-03-01

    Bio-invasions depend on the number and frequency of invaders arriving in new habitats. Yet, as is often the case, it is not only quantity that counts, but also quality. The process of dispersal can change disperser quality and establishment success. Invasions are a form of extra-range dispersal, so that invaders often experience changes in quality through dispersal. To study effects of dispersal on invader quality, and its interactions with quantity on invasion success, we manipulated both in a field experiment using an invasive marine invertebrate. Establishment success increased with the number of individuals arriving in a new habitat. Prolonged larval durations--our manipulation of prolonged dispersal--decreased individual quality and establishment success. Groups of invaders with prolonged larval durations contributed only a third of the offspring relative to invaders that settled immediately. We also found an interaction between the quality and quantity of invaders on individual growth: only within high-quality cohorts did individuals experience density-dependent effects on growth. Our findings highlight that dispersal not only affects the quantity of invaders arriving in a new habitat but also their quality, and both mediate establishment success.

  20. Mutualism between co-introduced species facilitates invasion and alters plant community structure

    PubMed Central

    Prior, Kirsten M.; Robinson, Jennifer M.; Meadley Dunphy, Shannon A.; Frederickson, Megan E.

    2015-01-01

    Generalized mutualisms are often predicted to be resilient to changes in partner identity. Variation in mutualism-related traits between native and invasive species however, can exacerbate the spread of invasive species (‘invasional meltdown’) if invasive partners strongly interact. Here we show how invasion by a seed-dispersing ant (Myrmica rubra) promotes recruitment of a co-introduced invasive over native ant-dispersed (myrmecochorous) plants. We created experimental communities of invasive (M. rubra) or native ants (Aphaenogaster rudis) and invasive and native plants and measured seed dispersal and plant recruitment. In our mesocosms, and in laboratory and field trials, M. rubra acted as a superior seed disperser relative to the native ant. By contrast, previous studies have found that invasive ants are often poor seed dispersers compared with native ants. Despite belonging to the same behavioural guild, seed-dispersing ants were not functionally redundant. Instead, native and invasive ants had strongly divergent effects on plant communities: the invasive plant dominated in the presence of the invasive ant and the native plants dominated in the presence of the native ant. Community changes were not due to preferences for coevolved partners: variation in functional traits of linked partners drove differences. Here, we show that strongly interacting introduced mutualists can be major drivers of ecological change. PMID:25540283

  1. Mutualism between co-introduced species facilitates invasion and alters plant community structure.

    PubMed

    Prior, Kirsten M; Robinson, Jennifer M; Meadley Dunphy, Shannon A; Frederickson, Megan E

    2015-02-01

    Generalized mutualisms are often predicted to be resilient to changes in partner identity. Variation in mutualism-related traits between native and invasive species however, can exacerbate the spread of invasive species ('invasional meltdown') if invasive partners strongly interact. Here we show how invasion by a seed-dispersing ant (Myrmica rubra) promotes recruitment of a co-introduced invasive over native ant-dispersed (myrmecochorous) plants. We created experimental communities of invasive (M. rubra) or native ants (Aphaenogaster rudis) and invasive and native plants and measured seed dispersal and plant recruitment. In our mesocosms, and in laboratory and field trials, M. rubra acted as a superior seed disperser relative to the native ant. By contrast, previous studies have found that invasive ants are often poor seed dispersers compared with native ants. Despite belonging to the same behavioural guild, seed-dispersing ants were not functionally redundant. Instead, native and invasive ants had strongly divergent effects on plant communities: the invasive plant dominated in the presence of the invasive ant and the native plants dominated in the presence of the native ant. Community changes were not due to preferences for coevolved partners: variation in functional traits of linked partners drove differences. Here, we show that strongly interacting introduced mutualists can be major drivers of ecological change. PMID:25540283

  2. The enemy of my enemy is my friend: intraguild predation between invaders and natives facilitates coexistence with shared invasive prey.

    PubMed

    MacNeil, Calum; Dick, Jaimie T A

    2014-08-01

    Understanding and predicting the outcomes of biological invasions is challenging where multiple invader and native species interact. We hypothesize that antagonistic interactions between invaders and natives could divert their impact on subsequent invasive species, thus facilitating coexistence. From field data, we found that, when existing together in freshwater sites, the native amphipod Gammarus duebeni celticus and a previous invader G. pulex appear to facilitate the establishment of a second invader, their shared prey Crangonyx pseudogracilis. Indeed, the latter species was rarely found at sites where each Gammarus species was present on its own. Experiments indicated that this may be the result of G. d. celticus and G. pulex engaging in more intraguild predation (IGP) than cannibalism; when the 'enemy' of either Gammarus species was present, that is, the other Gammarus species, C. pseudogracilis significantly more often escaped predation. Thus, the presence of mutual enemies and the stronger inter- than intraspecific interactions they engage in can facilitate other invaders. With some invasive species such as C. pseudogracilis having no known detrimental effects on native species, and indeed having some positive ecological effects, we also conclude that some invasions could promote biodiversity and ecosystem functioning.

  3. Stress for invasion success? Temperature stress of preceding generations modifies the response to insecticide stress in an invasive pest insect.

    PubMed

    Piiroinen, Saija; Lyytinen, Anne; Lindström, Leena

    2013-02-01

    Adaptation to stressful environments is one important factor influencing species invasion success. Tolerance to one stress may be complicated by exposure to other stressors experienced by the preceding generations. We studied whether parental temperature stress affects tolerance to insecticide in the invasive Colorado potato beetle Leptinotarsa decemlineata. Field-collected pyrethroid-resistant beetles were reared under either stressful (17°C) or favourable (23°C) insecticide-free environments for three generations. Then, larvae were exposed to pyrethroid insecticides in common garden conditions (23°C). Beetles were in general tolerant to stress. The parental temperature stress alone affected beetles positively (increased adult weight) but it impaired their tolerance to insecticide exposure. In contrast, offspring from the favourable temperature regime showed compensatory weight gain in response to insecticide exposure. Our study emphasizes the potential of cross-generational effects modifying species stress tolerance. When resistant pest populations invade benign environments, a re-application of insecticides may enhance their performance via hormetic effects. In turn, opposite effects may arise if parental generations have been exposed to temperature stress. Thus, the outcome of management practices of invasive pest species is difficult to predict unless we also incorporate knowledge of the evolutionary and recent (preceding generations) stress history of the given populations into pest management. PMID:23467574

  4. CO2 Enrichment and Warming Interact to Facilitate Invasion of a Semi-Arid Grassland

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Although a variety of global changes have been shown to influence plant invasions, interactive effects of different changes have rarely been studied. We examined effects of CO2 enrichment and warming on the ability of the invasive forb Linaria dalmatica (Dalmatian toadflax) to invade semi-arid mixed...

  5. Planting intensity, residence time, and species traits determine invasion success of alien woody species.

    PubMed

    Pysek, Petr; Krivánek, Martin; Jarosík, Vojtech

    2009-10-01

    We studied the relative importance of residence time, propagule pressure, and species traits in three stages of invasion of alien woody plants cultivated for about 150 years in the Czech Republic, Central Europe. The probability of escape from cultivation, naturalization, and invasion was assessed using classification trees. We compared 109 escaped-not-escaped congeneric pairs, 44 naturalized-not-naturalized, and 17 invasive-not-invasive congeneric pairs. We used the following predictors of the above probabilities: date of introduction to the target region as a measure of residence time; intensity of planting in the target area as a proxy for propagule pressure; the area of origin; and 21 species-specific biological and ecological traits. The misclassification rates of the naturalization and invasion model were low, at 19.3% and 11.8%, respectively, indicating that the variables used included the major determinants of these processes. The probability of escape increased with residence time in the Czech Republic, whereas the probability of naturalization increased with the residence time in Europe. This indicates that some species were already adapted to local conditions when introduced to the Czech Republic. Apart from residence time, the probability of escape depends on planting intensity (propagule pressure), and that of naturalization on the area of origin and fruit size; it is lower for species from Asia and those with small fruits. The probability of invasion is determined by a long residence time and the ability to tolerate low temperatures. These results indicate that a simple suite of factors determines, with a high probability, the invasion success of alien woody plants, and that the relative role of biological traits and other factors is stage dependent. High levels of propagule pressure as a result of planting lead to woody species eventually escaping from cultivation, regardless of biological traits. However, the biological traits play a role in later

  6. Dispersal and the design of effective management strategies for plant invasions: matching scales for success.

    PubMed

    Fletcher, Cameron S; Westcott, David A

    2013-12-01

    Dispersal of propagules makes invasions a fundamentally spatial phenomenon, and to be effective, management actions to control or eradicate invasive species must take this spatial structure into account. While there is a vibrant literature linking detailed dispersal measurements to the rate of invasive spread, and a separate literature focused on incorporating management into invasive models in order to improve the control of weeds, there are relatively fewer manuscripts incorporating state-of-the-art dispersal modeling and management modeling together to provide on-ground recommendations for structuring effective management. In this paper, we perform a generalized analysis of a spatially explicit, individual-based simulation model of invasion management with empirically determined dispersal processes, illustrated with the example of Miconia calvescens in the Australian Wet Tropics rain forest, to explore how matching the spatial scale of management to the spatial scale of the dispersal processes underpinning invasion influences the success of management. We find that management strategies designed to maximize the number of weeds removed from the management region, either in the first year of management or over longer periods, provide a poor estimate of the spatial scale of management that maximizes the probability of eradication. We show that achieving a goal of certainty of eradication requires exceeding a minimal spatial scale of management and total management resourcing. We generalize these results to examine how the spatial scale of dispersal drives the spatial scale of effective management strategies. These results show that to be effective, management of dispersal-driven invasions must occur at spatial scales determined by the scale of dispersal processes, and resourced accordingly. It illustrates how those scales might be calculated for a specific case for which detailed dispersal data are available and generalizes the result to highlight how dispersal

  7. Dispersal and the design of effective management strategies for plant invasions: matching scales for success.

    PubMed

    Fletcher, Cameron S; Westcott, David A

    2013-12-01

    Dispersal of propagules makes invasions a fundamentally spatial phenomenon, and to be effective, management actions to control or eradicate invasive species must take this spatial structure into account. While there is a vibrant literature linking detailed dispersal measurements to the rate of invasive spread, and a separate literature focused on incorporating management into invasive models in order to improve the control of weeds, there are relatively fewer manuscripts incorporating state-of-the-art dispersal modeling and management modeling together to provide on-ground recommendations for structuring effective management. In this paper, we perform a generalized analysis of a spatially explicit, individual-based simulation model of invasion management with empirically determined dispersal processes, illustrated with the example of Miconia calvescens in the Australian Wet Tropics rain forest, to explore how matching the spatial scale of management to the spatial scale of the dispersal processes underpinning invasion influences the success of management. We find that management strategies designed to maximize the number of weeds removed from the management region, either in the first year of management or over longer periods, provide a poor estimate of the spatial scale of management that maximizes the probability of eradication. We show that achieving a goal of certainty of eradication requires exceeding a minimal spatial scale of management and total management resourcing. We generalize these results to examine how the spatial scale of dispersal drives the spatial scale of effective management strategies. These results show that to be effective, management of dispersal-driven invasions must occur at spatial scales determined by the scale of dispersal processes, and resourced accordingly. It illustrates how those scales might be calculated for a specific case for which detailed dispersal data are available and generalizes the result to highlight how dispersal

  8. Phenology effects on invasion success: insights from coupling field experiments to coexistence theory.

    PubMed

    Godoy, Oscar; Levine, Jonathan M

    2014-03-01

    Ecologists have identified a growing number of functional traits that promote invasion. However, whether trait differences between exotic and native species promote invasion success by enhancing niche differences or giving invaders competitive advantages is poorly understood. We explored the mechanisms by which phenology determines invasion success in a California annual plant community by quantifying how the seasonal timing of growth relates to niche differences that stabilize coexistence, and the competitive ability differences that drive dominance and exclusion. We parameterized models of community dynamics from experimentally assembled annual communities in which exotic plants displayed earlier, coincident, or later phenology than native residents. Using recent theoretical advances from the coexistence literature, we found that differences in phenology promote stabilizing niche differences between exotic and native species. However, phenology was more strongly related to competitive ability differences, allowing later invaders to outcompete earlier native competitors and native residents to outcompete earlier invaders in field experiments. Few of these insights could be inferred by comparing the competitive outcomes across invaders, highlighting the need to quantify niche and competitive ability differences when disentangling how species differences drive invasion success.

  9. Preadaptation and post-introduction evolution facilitate the invasion of Phragmites australis in North America.

    PubMed

    Guo, Wen-Yong; Lambertini, Carla; Nguyen, Loc Xuan; Li, Xiu-Zhen; Brix, Hans

    2014-12-01

    Compared with non-invasive species, invasive plant species may benefit from certain advantageous traits, for example, higher photosynthesis capacity and resource/energy-use efficiency. These traits can be preadapted prior to introduction, but can also be acquired through evolution following introduction to the new range. Disentangling the origins of these advantageous traits is a fundamental and emerging question in invasion ecology. We conducted a multiple comparative experiment under identical environmental condition with the invasive haplotype M lineage of the wetland grass Phragmites australis and compared the ecophysiological traits of this invasive haplotype M in North America with those of the European ancestor and the conspecific North American native haplotype E lineage, P. australis ssp. americanus. The invasive haplotype M differed significantly from the native North American conspecific haplotype E in several ecophysiological and morphological traits, and the European haplotype M had a more efficient photosynthetic apparatus than the native North American P. australis ssp. americanus. Within the haplotype M lineage, the introduced North American P. australis exhibited different biomass allocation patterns and resource/energy-use strategies compared to its European ancestor group. A discriminant analysis of principal components separated the haplotype M and the haplotype E lineages completely along the first canonical axis, highly related to photosynthetic gas-exchange parameters, photosynthetic energy-use efficiency and payback time. The second canonical axis, highly related to photosynthetic nitrogen use efficiency and construction costs, significantly separated the introduced P. australis in North America from its European ancestor. Synthesis. We conclude that the European P. australis lineage was preadapted to be invasive prior to its introduction, and that the invasion in North America is further stimulated by rapid post-introduction evolution in

  10. Preadaptation and post-introduction evolution facilitate the invasion of Phragmites australis in North America.

    PubMed

    Guo, Wen-Yong; Lambertini, Carla; Nguyen, Loc Xuan; Li, Xiu-Zhen; Brix, Hans

    2014-12-01

    Compared with non-invasive species, invasive plant species may benefit from certain advantageous traits, for example, higher photosynthesis capacity and resource/energy-use efficiency. These traits can be preadapted prior to introduction, but can also be acquired through evolution following introduction to the new range. Disentangling the origins of these advantageous traits is a fundamental and emerging question in invasion ecology. We conducted a multiple comparative experiment under identical environmental condition with the invasive haplotype M lineage of the wetland grass Phragmites australis and compared the ecophysiological traits of this invasive haplotype M in North America with those of the European ancestor and the conspecific North American native haplotype E lineage, P. australis ssp. americanus. The invasive haplotype M differed significantly from the native North American conspecific haplotype E in several ecophysiological and morphological traits, and the European haplotype M had a more efficient photosynthetic apparatus than the native North American P. australis ssp. americanus. Within the haplotype M lineage, the introduced North American P. australis exhibited different biomass allocation patterns and resource/energy-use strategies compared to its European ancestor group. A discriminant analysis of principal components separated the haplotype M and the haplotype E lineages completely along the first canonical axis, highly related to photosynthetic gas-exchange parameters, photosynthetic energy-use efficiency and payback time. The second canonical axis, highly related to photosynthetic nitrogen use efficiency and construction costs, significantly separated the introduced P. australis in North America from its European ancestor. Synthesis. We conclude that the European P. australis lineage was preadapted to be invasive prior to its introduction, and that the invasion in North America is further stimulated by rapid post-introduction evolution in

  11. Preadaptation and post-introduction evolution facilitate the invasion of Phragmites australis in North America

    PubMed Central

    Guo, Wen-Yong; Lambertini, Carla; Nguyen, Loc Xuan; Li, Xiu-Zhen; Brix, Hans

    2014-01-01

    Compared with non-invasive species, invasive plant species may benefit from certain advantageous traits, for example, higher photosynthesis capacity and resource/energy-use efficiency. These traits can be preadapted prior to introduction, but can also be acquired through evolution following introduction to the new range. Disentangling the origins of these advantageous traits is a fundamental and emerging question in invasion ecology. We conducted a multiple comparative experiment under identical environmental condition with the invasive haplotype M lineage of the wetland grass Phragmites australis and compared the ecophysiological traits of this invasive haplotype M in North America with those of the European ancestor and the conspecific North American native haplotype E lineage, P. australis ssp. americanus. The invasive haplotype M differed significantly from the native North American conspecific haplotype E in several ecophysiological and morphological traits, and the European haplotype M had a more efficient photosynthetic apparatus than the native North American P. australis ssp. americanus. Within the haplotype M lineage, the introduced North American P. australis exhibited different biomass allocation patterns and resource/energy-use strategies compared to its European ancestor group. A discriminant analysis of principal components separated the haplotype M and the haplotype E lineages completely along the first canonical axis, highly related to photosynthetic gas-exchange parameters, photosynthetic energy-use efficiency and payback time. The second canonical axis, highly related to photosynthetic nitrogen use efficiency and construction costs, significantly separated the introduced P. australis in North America from its European ancestor. Synthesis. We conclude that the European P. australis lineage was preadapted to be invasive prior to its introduction, and that the invasion in North America is further stimulated by rapid post-introduction evolution in

  12. Understanding the importance of teachers in facilitating student success: Contemporary science, practice, and policy.

    PubMed

    Jimerson, Shane R; Haddock, Aaron D

    2015-12-01

    Teacher quality has a vital influence on student success or failure. Thus, further research regarding teacher effectiveness, teacher evaluation, teacher well-being, and teacher contributions is essential to inform school psychologists and allied educational professionals who collaborate and consult with teachers to facilitate student success. In this special topic section of School Psychology Quarterly, a series of 6 articles further elucidate teachers' powerful contributions to student outcomes along with concrete, research-based ways for school psychologists to support and collaborate with teachers. The studies included in the special section describe how teacher support facilitates students' positive academic and social-emotional outcomes and how students' attitudes toward learning moderate the association between the classroom environment and students' academic achievement. Studies also report on the development and validation of self-report measures focused on both teacher subjective well-being and teachers' use of evidence-based practices. Finally, the articles included in the special topic section offer insights and ideas for refining teacher evaluation practices, understanding the factors contributing to program implementation fidelity, and improving prevention, early identification, and intervention efforts aimed at fostering school completion and positive youth development. PMID:26641958

  13. Facilitators and barriers to success among ethnic minority students enrolled in a predominately white baccalaureate nursing program.

    PubMed

    Smith, Charlene B; Williams-Jones, Pamela; Lewis-Trabeaux, Shirleen; Mitchell, Denise

    2012-07-01

    This study identified facilitators and barriers to academic success among ethnic minority students enrolled in a BSN program. The following research questions were asked: What factors (a) facilitate academic performance; (b) are barriers to academic performance; (c) influence the college experience and academic success; (d) within the nursing department, influence academic success; (e) What is the impact of socialization on academic performance; (f) What were facilitators of academic success identified among study participants; and, (g) Which facilitators, identified by subjects, were most common among those participants? A retrospective-descriptive study design consisted of a sample of all minority students who were enrolled in clinical at a baccalaureate nursing program between 2005 and the fall of 2010. Bandura's theory on self-efficacy was used. Loftus and Duty's Survey of Factors Influencing Student Retention and Academic Success was adapted. Data were analyzed using SPSS 19.0 with ANOVA to determine if a significant difference in responses existed.

  14. Jack-of-all-trades: phenotypic plasticity facilitates the invasion of an alien slug species.

    PubMed

    Knop, Eva; Reusser, Nik

    2012-11-22

    Invasive alien species might benefit from phenotypic plasticity by being able to (i) maintain fitness in stressful environments ('robust'), (ii) increase fitness in favourable environments ('opportunistic'), or (iii) combine both abilities ('robust and opportunistic'). Here, we applied this framework, for the first time, to an animal, the invasive slug, Arion lusitanicus, and tested (i) whether it has a more adaptive phenotypic plasticity compared with a congeneric native slug, Arion fuscus, and (ii) whether it is robust, opportunistic or both. During one year, we exposed specimens of both species to a range of temperatures along an altitudinal gradient (700-2400 m a.s.l.) and to high and low food levels, and we compared the responsiveness of two fitness traits: survival and egg production. During summer, the invasive species had a more adaptive phenotypic plasticity, and at high temperatures and low food levels, it survived better and produced more eggs than A. fuscus, representing the robust phenotype. During winter, A. lusitanicus displayed a less adaptive phenotype than A. fuscus. We show that the framework developed for plants is also very useful for a better mechanistic understanding of animal invasions. Warmer summers and milder winters might lead to an expansion of this invasive species to higher altitudes and enhance its spread in the lowlands, supporting the concern that global climate change will increase biological invasions.

  15. Evidence does not support a role for gallic acid in Phragmites australis invasion success.

    PubMed

    Weidenhamer, Jeffrey D; Li, Mei; Allman, Joshua; Bergosh, Robert G; Posner, Mason

    2013-02-01

    Gallic acid has been reported to be responsible for the invasive success of nonnative genotypes of Phragmites australis in North America. We have been unable to confirm previous reports of persistent high concentrations of gallic acid in the rhizosphere of invasive P. australis, and of high concentrations of gallic acid and gallotannins in P. australis rhizomes. The half-life of gallic acid in nonsterile P. australis soil was measured by aqueous extraction of soils and found to be less than 1 day at added concentrations up to 10,000 μg g(-1). Furthermore, extraction of P. australis soil collected in North Carolina showed no evidence of gallic acid, and extractions of both rhizomes and leaves of samples of four P. australis populations confirmed to be of invasive genotype show only trace amounts of gallic acid and/or gallotannins. The detection limits were less than 20 μg gallic acid g(-1) FW in the rhizome samples tested, which is approximately 0.015 % of the minimum amount of gallic acid expected based on previous reports. While the occurrence of high concentrations of gallic acid and gallotannins in some local populations of P. australis cannot be ruled out, our results indicate that exudation of gallic acid by P. australis cannot be a primary, general explanation for the invasive success of this species in North America.

  16. A qualitative investigation of barriers and facilitators of rehabilitation success from the psychosomatic inpatients’ perspective

    PubMed Central

    Brütt, Anna Levke; Magaard, Julia Luise; Andreas, Sylke; Schulz, Holger

    2016-01-01

    Objective Psychosomatic inpatient rehabilitation aims at promoting functioning in patients with mental disorders. Although generally effective, some patients do not benefit from this rehabilitation and suffer from symptoms as well as functional impairment. This study aimed to identify patient-reported factors influencing activity and participation outcomes. Subject and methods Five focus groups with N=23 former psychosomatic rehabilitation inpatients were conducted. The discussions focused on facilitators and barriers of treatment outcome. The material was analyzed inductively according to qualitative content analysis. Categories were derived from the material. Results Patients reported sociodemographic and clinical characteristics as well as personal factors, preparation before psychotherapy, and aspects of employment and health care as predictors of treatment success. Conclusion A wide range of possible factors that influence the course of functioning from the patients’ perspective were determined. These factors can be assigned to the ICF conceptual model. Clinician and researcher perspectives may complement these factors.

  17. A qualitative investigation of barriers and facilitators of rehabilitation success from the psychosomatic inpatients’ perspective

    PubMed Central

    Brütt, Anna Levke; Magaard, Julia Luise; Andreas, Sylke; Schulz, Holger

    2016-01-01

    Objective Psychosomatic inpatient rehabilitation aims at promoting functioning in patients with mental disorders. Although generally effective, some patients do not benefit from this rehabilitation and suffer from symptoms as well as functional impairment. This study aimed to identify patient-reported factors influencing activity and participation outcomes. Subject and methods Five focus groups with N=23 former psychosomatic rehabilitation inpatients were conducted. The discussions focused on facilitators and barriers of treatment outcome. The material was analyzed inductively according to qualitative content analysis. Categories were derived from the material. Results Patients reported sociodemographic and clinical characteristics as well as personal factors, preparation before psychotherapy, and aspects of employment and health care as predictors of treatment success. Conclusion A wide range of possible factors that influence the course of functioning from the patients’ perspective were determined. These factors can be assigned to the ICF conceptual model. Clinician and researcher perspectives may complement these factors. PMID:27698554

  18. Educating ethnic minority students for the nursing workforce: facilitators and barriers to success.

    PubMed

    Loftus, Jocelyn; Duty, Susan

    2010-07-01

    The number of ethnic minorities graduating from nursing programs does not meet the number of ethnic minority nurses that are needed for patient care. In order to identify the facilitators and barriers to success, a survey was sent to current students and to those who graduated within 2 years. There were 314 responses, which was an overall response rate of 39.6%. Among the 4 facilitator factors, only the general academic support factor was perceived as more helpful by African-American students (p = 0.001). Among the 5 barrier factors, African-American students and Other Ethnic Minority students perceived program workload and pace (African-Americans p < 0.005; Other multicultural groups p < 0.02), computer access (African-Americans p < 0.05; Other multicultural groups p < 0.05) and technology competence (African-Americans p < 0.02) to be barriers. Any student, regardless of ethnicity, who worked at a job 13 to 40 hours a week, perceived family and financial concerns as a barrier. Results indicated that curriculum content should include technology basics and testing for competence. Financial support for students must be expanded through loans and scholarships so workload and pace become more manageable.

  19. Kelp canopy facilitates understory algal assemblage via competitive release during early stages of secondary succession.

    PubMed

    Benes, Kylla M; Carpenter, Robert C

    2015-01-01

    Kelps are conspicuous foundation species in marine ecosystems that alter the composition of understory algal assemblages. While this may be due to changes in the competitive interactions between algal species, how kelp canopies mediate propagule supply and establishment success of understory algae is not well known. In Southern California, USA, Eisenia arborea forms dense kelp canopies in shallow subtidal environments and is associated with an understory dominated by red algal species. In canopy-free areas, however, the algal assemblage is comprised of mostly brown algal species. We used a combination of mensurative and manipulative experiments to test whether Eisenia facilitates the understory assemblage by reducing competition between these different types of algae by changes in biotic interactions and/or recruitment. Our results show Eisenia facilitates a red algal assemblage via inhibition of brown algal settlement into the canopy zone, allowing recruitment to occur by vegetative means rather than establishment of new individuals. In the canopy-free zone, however, high settlement and recruitment rates suggest competitive interactions shape the community there. These results demonstrate that foundation species alter the distribution and abundance of associated organisms by affecting not only interspecific interactions but also propagule supply and recruitment limitation.

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

    PubMed

    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.

  1. Biotic and abiotic controls of argentine ant invasion success at local and landscape scales

    USGS Publications Warehouse

    Menke, S.B.; Fisher, R.N.; Jetz, W.; Holway, D.A.

    2007-01-01

    Although the ecological success of introduced species hinges on biotic interactions and physical conditions, few experimental studies - especially on animals - have simultaneously investigated the relative importance of both types of factors. The lack of such research may stem from the common assumption that native and introduced species exhibit similar environmental tolerances. Here we combine experimental and spatial modeling approaches (1) to determine the relative importance of biotic and abiotic controls of Argentine ant (Linepithema humile) invasion success, (2) to examine how the importance of these factors changes with spatial scale in southern California (USA), and (3) to assess how Argentine ants differ from native ants in their environmental tolerances. A factorial field experiment that combined native ant removal with irrigation revealed that Argentine ants failed to invade any dry plots (even those lacking native ants) but readily invaded all moist plots. Native ants slowed the spread of Argentine ants into irrigated plots but did not prevent invasion. In areas without Argentine ants, native ant species showed variable responses to irrigation. At the landscape scale, Argentine ant occurrence was positively correlated with minimum winter temperature (but not precipitation), whereas native ant diversity increased with precipitation and was negatively correlated with minimum winter temperature. These results are of interest for several reasons. First, they demonstrate that fine-scale differences in the physical environment can eclipse biotic resistance from native competitors in determining community susceptibility to invasion. Second, our results illustrate surprising complexities with respect to how the abiotic factors limiting invasion can change with spatial scale, and third, how native and invasive species can differ in their responses to the physical environment. Idiosyncratic and scale-dependent processes complicate attempts to forecast where

  2. Invasive parasites, habitat change and heavy rainfall reduce breeding success in Darwin's finches.

    PubMed

    Cimadom, Arno; Ulloa, Angel; Meidl, Patrick; Zöttl, Markus; Zöttl, Elisabet; Fessl, Birgit; Nemeth, Erwin; Dvorak, Michael; Cunninghame, Francesca; Tebbich, Sabine

    2014-01-01

    Invasive alien parasites and pathogens are a growing threat to biodiversity worldwide, which can contribute to the extinction of endemic species. On the Galápagos Islands, the invasive parasitic fly Philornis downsi poses a major threat to the endemic avifauna. Here, we investigated the influence of this parasite on the breeding success of two Darwin's finch species, the warbler finch (Certhidea olivacea) and the sympatric small tree finch (Camarhynchus parvulus), on Santa Cruz Island in 2010 and 2012. While the population of the small tree finch appeared to be stable, the warbler finch has experienced a dramatic decline in population size on Santa Cruz Island since 1997. We aimed to identify whether warbler finches are particularly vulnerable during different stages of the breeding cycle. Contrary to our prediction, breeding success was lower in the small tree finch than in the warbler finch. In both species P. downsi had a strong negative impact on breeding success and our data suggest that heavy rain events also lowered the fledging success. On the one hand parents might be less efficient in compensating their chicks' energy loss due to parasitism as they might be less efficient in foraging on days of heavy rain. On the other hand, intense rainfalls might lead to increased humidity and more rapid cooling of the nests. In the case of the warbler finch we found that the control of invasive plant species with herbicides had a significant additive negative impact on the breeding success. It is very likely that the availability of insects (i.e. food abundance)is lower in such controlled areas, as herbicide usage led to the removal of the entire understory. Predation seems to be a minor factor in brood loss.

  3. Invasive Parasites, Habitat Change and Heavy Rainfall Reduce Breeding Success in Darwin's Finches

    PubMed Central

    Cimadom, Arno; Ulloa, Angel; Meidl, Patrick; Zöttl, Markus; Zöttl, Elisabet; Fessl, Birgit; Nemeth, Erwin; Dvorak, Michael; Cunninghame, Francesca; Tebbich, Sabine

    2014-01-01

    Invasive alien parasites and pathogens are a growing threat to biodiversity worldwide, which can contribute to the extinction of endemic species. On the Galápagos Islands, the invasive parasitic fly Philornis downsi poses a major threat to the endemic avifauna. Here, we investigated the influence of this parasite on the breeding success of two Darwin's finch species, the warbler finch (Certhidea olivacea) and the sympatric small tree finch (Camarhynchus parvulus), on Santa Cruz Island in 2010 and 2012. While the population of the small tree finch appeared to be stable, the warbler finch has experienced a dramatic decline in population size on Santa Cruz Island since 1997. We aimed to identify whether warbler finches are particularly vulnerable during different stages of the breeding cycle. Contrary to our prediction, breeding success was lower in the small tree finch than in the warbler finch. In both species P. downsi had a strong negative impact on breeding success and our data suggest that heavy rain events also lowered the fledging success. On the one hand parents might be less efficient in compensating their chicks' energy loss due to parasitism as they might be less efficient in foraging on days of heavy rain. On the other hand, intense rainfalls might lead to increased humidity and more rapid cooling of the nests. In the case of the warbler finch we found that the control of invasive plant species with herbicides had a significant additive negative impact on the breeding success. It is very likely that the availability of insects (i.e. food abundance)is lower in such controlled areas, as herbicide usage led to the removal of the entire understory. Predation seems to be a minor factor in brood loss. PMID:25248092

  4. Successful treatment of a persistent mole with myometrial invasion by direct injection of methotrexate.

    PubMed

    Su, W H; Wang, P H; Chang, S P

    2001-01-01

    For patients with persistent or invasive gestational trophoblastic disease (GTD), systemic injection of chemotherapy is the treatment of choice if fertility is to be preserved. To prevent serious adverse effects after systemic use and possibly achieve better effects, direct local injection of chemotherapy into the tumor site, especially when in the myometrium, seems a reasonable alternative. A patient with a persistent molar pregnancy with myometrial invasion is presented. A plateau of beta-hCG (human chorionic gonadotropin) level around 550 mIU/mL was noticed for three weeks though systemic methotrexate (MTX) injection and repeat suction curettage had been performed. During the same period, a well-defined invasive complex with multiple vesicles in the myometrium was documented using transvaginal ultrasound (TVUS). Sonar-guided injection to the tumor using 50 mg MTX was performed uneventfully. An obvious shrinkage of the mass and declining beta-hCG level were demonstrated after the procedure. The patient restored her menses after the operation and a fertility evaluation including serial beta-hCG levels and hysterosalpingography showed them to be within the reference ranges. The successful outcome of this case encouraged us to treat localized invasive GTD using direct injection of MTX with the guidance of TVUS. Since no identical cases were found in our review of the English literature, more cases and similar regimens are needed to establish the safety and efficacy of this procedure.

  5. Women with doctorates in science: Perceptions of facilitative factors and obstacles to their success

    NASA Astrophysics Data System (ADS)

    Guimond, Pamela S.

    In the past thirty years there has been a significant increase in the number of women pursuing careers in the biological sciences, yet similar increases have not been seen in the physical sciences or engineering. Research suggests that societal, educational, and personal factors may be the cause. This study was designed to validate factors previously identified as being influential on the learning of science by women, as well as to discover factors not previously identified and to gain an understanding of the degree to which each of these factors is perceived to relate to their academic success. Quantitative and qualitative methodologies were used to identify factors that facilitated the success of or presented obstacles to women as they pursued doctoral degrees in physical science and engineering. Sixty-four women scientists completed surveys. Of these, twelve participated in telephone interviews. The data collected from these methodologies, when taken together, allowed for both a generalizability of results and in-depth understanding of the factors identified. Three major themes were identified. First was the importance of people in these women's lives. Second was each woman's expression of personality traits including passion, determination, and resilience. Third was the importance of support from a variety of sources. All of the scientists considered support necessary for their success. Implications for practice include: providing girls with a wide variety of experiences in mathematics and science, including both in-school and out-of-school activities; providing girls with role models and mentors; utilizing a variety of teaching strategies aimed at girls' preferred learning styles; providing a variety of kinds of support girls need to feel welcome and valued; developing in girls personal characteristics associated with the culture of science; minimizing the use of high-stakes exams; and maximizing schedule flexibility so women can combine scientific careers and

  6. Loss of native herbaceous species due to woody plant encroachment facilitates the establishment of an invasive grass.

    PubMed

    Alofs, Karen M; Fowler, Norma L

    2013-03-01

    Although negative relationships between diversity (frequently measured as species richness) and invasibility at neighborhood or community scales have often been reported, realistic natural diversity gradients have rarely been studied at this scale. We recreated a naturally occurring gradient in species richness to test the effects of species richness on community invasibility. In central Texas savannas, as the proportion of woody plants increases (a process known as woody plant encroachment), herbaceous habitat is both lost and fragmented, and native herbaceous species richness declines. We examined the effects of these species losses on invasibility in situ by removing species that occur less frequently in herbaceous patches as woody plant encroachment advances. This realistic species removal was accompanied by a parallel and equivalent removal of biomass with no changes in species richness. Over two springs, the nonnative bunchgrass Bothriochloa ischaemum germinated significantly more often in the biomass-removal treatment than in unmanipulated control plots, suggesting an effect of native plant density independent of diversity. Additionally, significantly more germination occurred in the species-removal treatment than in the biomass-removal treatment. Changes in species richness had a stronger effect on B. ischaemum germination than changes in plant density, demonstrating that niche-related processes contributed more to biotic resistance in this system than did species-neutral competitive interactions. Similar treatment effects were found on transplant growth. Thus we show that woody plant encroachment indirectly facilitates the establishment of an invasive grass by reducing native diversity. Although we found a negative relationship between species richness and invasibility at the scale of plots with similar composition and environmental conditions, we found a positive relationship between species richness and invasibility at larger scales. This apparent

  7. Does Ecophysiology Determine Invasion Success? A Comparison between the Invasive Boatman Trichocorixa verticalis verticalis and the Native Sigara lateralis (Hemiptera, Corixidae) in South-West Spain

    PubMed Central

    Coccia, Cristina; Calosi, Piero; Boyero, Luz; Green, Andy J.; Bilton, David T.

    2013-01-01

    Background Trichocorixa verticalis verticalis, a native of North America, is the only alien corixid identified in Europe. First detected in 1997 in southern Portugal, it has spread into south-west Spain including Doñana National Park. Its impact on native taxa in the same area is unclear, but it is the dominant species in several permanent, saline wetlands. Methodology/Principal Findings We investigated whether the ecophysiology of this alien species favours its spread in the Iberian Peninsula and its relative success in saline areas. We compared physiological responses to heating (Critical Thermal maximum), cooling (Critical Thermal minimum) and freezing (Super Cooling Point) in the native Sigara lateralis and introduced T. v. verticalis acclimated to different temperatures and salinities. The larger S. lateralis generally outperformed T. v. verticalis and appeared to possess a broader thermal tolerance range. In both taxa, CTmax was highest in animals exposed to a combination of high conductivities and relatively low acclimation temperatures. However, CTmax was generally higher in T. v. verticalis and lower in S. lateralis when acclimated at higher temperatures. CTmin were lower (greater tolerance to cold) after acclimation to high conductivities in T. v. verticalis, and following acclimation to low conductivities in S. lateralis. Both acclimation temperature and conductivity influenced corixids' freezing tolerance; however, only in T. v. verticalis did SCP decrease after exposure to both high temperature and conductivity. T. v. verticalis showed a higher range of mean responses over all treatments. Conclusions Whilst the native S. lateralis may have a broader thermal range, the alien species performs particularly well at higher salinities and temperatures and this ability may facilitate its invasion in Mediterranean areas. The greater plasticity of T. v. verticalis may further facilitate its spread in the future, as it may be more able to respond to climate

  8. Intraguild Predation Behaviour of Ladybirds in Semi-Field Experiments Explains Invasion Success of Harmonia axyridis

    PubMed Central

    Van Lenteren, Joop 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. axyridis. The aim of this study was to compare the intraguild predation behaviour of three ladybird species (Coccinella septempunctata, Adalia bipunctata, and H. axyridis). Predation behaviour was investigated in semi-field experiments on small lime trees (Tilia platyphyllos). Two fourth-instar larvae placed on a tree rarely made contact during 3-hour observations. When placed together on a single leaf in 23%–43% of the observations at least one contact was made. Of those contacts 0%–27% resulted in an attack. Harmonia axyridis attacked mostly heterospecifics, while A. bipunctata and C. septempunctata attacked heterospecifics as often as conspecifics. In comparison with A. bipunctata and C. septempunctata, H. axyridis was the most successful intraguild predator as it won 86% and 44% of heterospecific battles against A. bipunctata and C. septempunctata respectively, whilst A. bipunctata won none of the heterospecific battles and C. septempunctata won only the heterospecific battles against A. bipunctata. Coccinella septempunctata dropped from a leaf earlier and more often than the other two species but was in some cases able to return to the tree, especially under cloudy conditions. The frequency with which a species dropped did not depend on the species the larva was paired with. The results of these semi-field experiments confirm that H. axyridis is a strong intraguild predator as a consequence of its aggressiveness and good defence against predation from heterospecific species. The fact that H. axyridis is such a strong intraguild predator helps to explain its successful establishment as invasive alien species in Europe and the USA. PMID:22815790

  9. FACILITATED INVASIONS: A NON-NATIVE FISH INCREASES SURVIVAL OF A NON-NATIVE ANURAN

    EPA Science Inventory

    The introduction of a variety of non-native gamefish to formerly fishless ponds and lakes represents one of the most widespread alterations of freshwater habitats in western North America. We hypothesized that introduced bluegill are facilitating the survival of introduced bullf...

  10. Revisiting photodynamic therapy dosimetry: reductionist & surrogate approaches to facilitate clinical success.

    PubMed

    Pogue, Brian W; Elliott, Jonathan T; Kanick, Stephen C; Davis, Scott C; Samkoe, Kimberley S; Maytin, Edward V; Pereira, Stephen P; Hasan, Tayyaba

    2016-04-01

    Photodynamic therapy (PDT) can be a highly complex treatment, with many parameters influencing treatment efficacy. The extent to which dosimetry is used to monitor and standardize treatment delivery varies widely, ranging from measurement of a single surrogate marker to comprehensive approaches that aim to measure or estimate as many relevant parameters as possible. Today, most clinical PDT treatments are still administered with little more than application of a prescribed drug dose and timed light delivery, and thus the role of patient-specific dosimetry has not reached widespread clinical adoption. This disconnect is at least partly due to the inherent conflict between the need to measure and understand multiple parameters in vivo in order to optimize treatment, and the need for expedience in the clinic and in the regulatory and commercialization process. Thus, a methodical approach to selecting primary dosimetry metrics is required at each stage of translation of a treatment procedure, moving from complex measurements to understand PDT mechanisms in pre-clinical and early phase I trials, towards the identification and application of essential dose-limiting and/or surrogate measurements in phase II/III trials. If successful, identifying the essential and/or reliable surrogate dosimetry measurements should help facilitate increased adoption of clinical PDT. In this paper, examples of essential dosimetry points and surrogate dosimetry tools that may be implemented in phase II/III trials are discussed. For example, the treatment efficacy as limited by light penetration in interstitial PDT may be predicted by the amount of contrast uptake in CT, and so this could be utilized as a surrogate dosimetry measurement to prescribe light doses based upon pre-treatment contrast. Success of clinical ALA-based skin lesion treatment is predicted almost uniquely by the explicit or implicit measurements of photosensitizer and photobleaching, yet the individualization of treatment

  11. Revisiting photodynamic therapy dosimetry: reductionist & surrogate approaches to facilitate clinical success.

    PubMed

    Pogue, Brian W; Elliott, Jonathan T; Kanick, Stephen C; Davis, Scott C; Samkoe, Kimberley S; Maytin, Edward V; Pereira, Stephen P; Hasan, Tayyaba

    2016-04-01

    Photodynamic therapy (PDT) can be a highly complex treatment, with many parameters influencing treatment efficacy. The extent to which dosimetry is used to monitor and standardize treatment delivery varies widely, ranging from measurement of a single surrogate marker to comprehensive approaches that aim to measure or estimate as many relevant parameters as possible. Today, most clinical PDT treatments are still administered with little more than application of a prescribed drug dose and timed light delivery, and thus the role of patient-specific dosimetry has not reached widespread clinical adoption. This disconnect is at least partly due to the inherent conflict between the need to measure and understand multiple parameters in vivo in order to optimize treatment, and the need for expedience in the clinic and in the regulatory and commercialization process. Thus, a methodical approach to selecting primary dosimetry metrics is required at each stage of translation of a treatment procedure, moving from complex measurements to understand PDT mechanisms in pre-clinical and early phase I trials, towards the identification and application of essential dose-limiting and/or surrogate measurements in phase II/III trials. If successful, identifying the essential and/or reliable surrogate dosimetry measurements should help facilitate increased adoption of clinical PDT. In this paper, examples of essential dosimetry points and surrogate dosimetry tools that may be implemented in phase II/III trials are discussed. For example, the treatment efficacy as limited by light penetration in interstitial PDT may be predicted by the amount of contrast uptake in CT, and so this could be utilized as a surrogate dosimetry measurement to prescribe light doses based upon pre-treatment contrast. Success of clinical ALA-based skin lesion treatment is predicted almost uniquely by the explicit or implicit measurements of photosensitizer and photobleaching, yet the individualization of treatment

  12. Revisiting photodynamic therapy dosimetry: reductionist & surrogate approaches to facilitate clinical success

    NASA Astrophysics Data System (ADS)

    Pogue, Brian W.; Elliott, Jonathan T.; Kanick, Stephen C.; Davis, Scott C.; Samkoe, Kimberley S.; Maytin, Edward V.; Pereira, Stephen P.; Hasan, Tayyaba

    2016-04-01

    Photodynamic therapy (PDT) can be a highly complex treatment, with many parameters influencing treatment efficacy. The extent to which dosimetry is used to monitor and standardize treatment delivery varies widely, ranging from measurement of a single surrogate marker to comprehensive approaches that aim to measure or estimate as many relevant parameters as possible. Today, most clinical PDT treatments are still administered with little more than application of a prescribed drug dose and timed light delivery, and thus the role of patient-specific dosimetry has not reached widespread clinical adoption. This disconnect is at least partly due to the inherent conflict between the need to measure and understand multiple parameters in vivo in order to optimize treatment, and the need for expedience in the clinic and in the regulatory and commercialization process. Thus, a methodical approach to selecting primary dosimetry metrics is required at each stage of translation of a treatment procedure, moving from complex measurements to understand PDT mechanisms in pre-clinical and early phase I trials, towards the identification and application of essential dose-limiting and/or surrogate measurements in phase II/III trials. If successful, identifying the essential and/or reliable surrogate dosimetry measurements should help facilitate increased adoption of clinical PDT. In this paper, examples of essential dosimetry points and surrogate dosimetry tools that may be implemented in phase II/III trials are discussed. For example, the treatment efficacy as limited by light penetration in interstitial PDT may be predicted by the amount of contrast uptake in CT, and so this could be utilized as a surrogate dosimetry measurement to prescribe light doses based upon pre-treatment contrast. Success of clinical ALA-based skin lesion treatment is predicted almost uniquely by the explicit or implicit measurements of photosensitizer and photobleaching, yet the individualization of treatment

  13. Native Predators Do Not Influence Invasion Success of Pacific Lionfish on Caribbean Reefs

    PubMed Central

    Hackerott, Serena; Valdivia, Abel; Green, Stephanie J.; Côté, Isabelle M.; Cox, Courtney E.; Akins, Lad; Layman, Craig A.; Precht, William F.; Bruno, John F.

    2013-01-01

    Biotic resistance, the process by which new colonists are excluded from a community by predation from and/or competition with resident species, can prevent or limit species invasions. We examined whether biotic resistance by native predators on Caribbean coral reefs has influenced the invasion success of red lionfishes (Pterois volitans and Pterois miles), piscivores from the Indo-Pacific. Specifically, we surveyed the abundance (density and biomass) of lionfish and native predatory fishes that could interact with lionfish (either through predation or competition) on 71 reefs in three biogeographic regions of the Caribbean. We recorded protection status of the reefs, and abiotic variables including depth, habitat type, and wind/wave exposure at each site. We found no relationship between the density or biomass of lionfish and that of native predators. However, lionfish densities were significantly lower on windward sites, potentially because of habitat preferences, and in marine protected areas, most likely because of ongoing removal efforts by reserve managers. Our results suggest that interactions with native predators do not influence the colonization or post-establishment population density of invasive lionfish on Caribbean reefs. PMID:23874565

  14. Native predators do not influence invasion success of pacific lionfish on Caribbean reefs.

    PubMed

    Hackerott, Serena; Valdivia, Abel; Green, Stephanie J; Côté, Isabelle M; Cox, Courtney E; Akins, Lad; Layman, Craig A; Precht, William F; Bruno, John F

    2013-01-01

    Biotic resistance, the process by which new colonists are excluded from a community by predation from and/or competition with resident species, can prevent or limit species invasions. We examined whether biotic resistance by native predators on Caribbean coral reefs has influenced the invasion success of red lionfishes (Pterois volitans and Pterois miles), piscivores from the Indo-Pacific. Specifically, we surveyed the abundance (density and biomass) of lionfish and native predatory fishes that could interact with lionfish (either through predation or competition) on 71 reefs in three biogeographic regions of the Caribbean. We recorded protection status of the reefs, and abiotic variables including depth, habitat type, and wind/wave exposure at each site. We found no relationship between the density or biomass of lionfish and that of native predators. However, lionfish densities were significantly lower on windward sites, potentially because of habitat preferences, and in marine protected areas, most likely because of ongoing removal efforts by reserve managers. Our results suggest that interactions with native predators do not influence the colonization or post-establishment population density of invasive lionfish on Caribbean reefs.

  15. Non-invasive investigations successfully select patients for temporal lobe surgery

    PubMed Central

    Kilpatrick, C.; Cook, M.; Kaye, A.; Murphy, M.; Matkovic, Z.

    1997-01-01

    OBJECTIVES—There is controversy regarding the need for invasive monitoring in the preoperative assessment of patients with temporal lobe epilepsy. The use of a series of non-invasive investigations in identifying the seizure focus is reported in 75 consecutive adults referred for epilepsy surgery.
METHODS—All had video-EEG monitoring using scalp electrodes, high resolution MRI, and neuropsychology assessment. Other investigations included volumetric MRI, PET, and ictal and interictal SPECT. The seizure focus was localised and surgery offered if MRI disclosed unilateral hippocampal atrophy or a foreign tissue lesion and other investigations were either concordant or not discordant.
RESULTS—In 68 patients the seizure focus was localised and three patients were inoperable. Sixty five patients have been offered surgery and 50 have undergone temporal lobe surgery and have a follow up of at least 12 months (mean 24 months). All had pathology: hippocampal sclerosis 34, dysembryoblastic neuroepithelial tumour six, cavernoma four, dysplasia two, low grade glioma two, ganglioglioma two. Thirty nine patients (78%) are seizure free postoperatively, 29/34 with hippocampal sclerosis and 10/16 with a foreign tissue lesion. Of the 11 patients with postoperative recurrent seizures, eight have a >90% reduction in seizure frequency and three have <90% reduction in seizure frequency but a worthwhile improvement.
CONCLUSIONS—Non-invasive investigations successfully select most patients for temporal lobe surgery.

 PMID:9328249

  16. Can adaptive modulation of traits to urban environments facilitate Ricinus communis L. invasiveness?

    PubMed

    Goyal, Neha; Pardha-Saradhi, P; Sharma, Gyan P

    2014-11-01

    This paper addresses the phenotypic variation among Ricinus communis L. populations in four urban habitat types (road verges, garbage dumps, construction debris, and natural area) in Delhi, India, by evaluating important traits such as plant height, basal circumference, seeds per plant, seed size, seed weight, specific leaf area, and reproductive index. An important biochemical marker, proline, considered as a good plant performance indicator under stress was also quantified in leaves of R. communis to evaluate its response in different habitats. Interestingly, the species showed significant variation in plant height, specific leaf area, seed size, seed weight, and leaf proline content in different habitat types. Leaf proline content was positively related to plant height, specific leaf area, and seed size while negatively related to the total number of seeds/plant. Interestingly, reproductive index, calculated as a ratio of the total number of seeds to the plant height also showed a negative relation with leaf proline content. Results indicated that R. communis exhibits adaptive modulation of growth, reproductive traits, and leaf proline content in various urban habitats which contributes to invasiveness, range expansion, and establishment of the species. The study also gives evidence of how morphological and physiological traits could directly affect invasiveness of R. communis.

  17. Can adaptive modulation of traits to urban environments facilitate Ricinus communis L. invasiveness?

    PubMed

    Goyal, Neha; Pardha-Saradhi, P; Sharma, Gyan P

    2014-11-01

    This paper addresses the phenotypic variation among Ricinus communis L. populations in four urban habitat types (road verges, garbage dumps, construction debris, and natural area) in Delhi, India, by evaluating important traits such as plant height, basal circumference, seeds per plant, seed size, seed weight, specific leaf area, and reproductive index. An important biochemical marker, proline, considered as a good plant performance indicator under stress was also quantified in leaves of R. communis to evaluate its response in different habitats. Interestingly, the species showed significant variation in plant height, specific leaf area, seed size, seed weight, and leaf proline content in different habitat types. Leaf proline content was positively related to plant height, specific leaf area, and seed size while negatively related to the total number of seeds/plant. Interestingly, reproductive index, calculated as a ratio of the total number of seeds to the plant height also showed a negative relation with leaf proline content. Results indicated that R. communis exhibits adaptive modulation of growth, reproductive traits, and leaf proline content in various urban habitats which contributes to invasiveness, range expansion, and establishment of the species. The study also gives evidence of how morphological and physiological traits could directly affect invasiveness of R. communis. PMID:25103212

  18. Recent Invasion of the Symbiont-Bearing Foraminifera Pararotalia into the Eastern Mediterranean Facilitated by the Ongoing Warming Trend.

    PubMed

    Schmidt, Christiane; Morard, Raphael; Almogi-Labin, Ahuva; Weinmann, Anna E; Titelboim, Danna; Abramovich, Sigal; Kucera, Michal

    2015-01-01

    , our results indicate that continued warming of the eastern Mediterranean will facilitate the invasion of more tropical marine taxa into the Mediterranean, disturbing local biodiversity and ecosystem structure. PMID:26270964

  19. Recent Invasion of the Symbiont-Bearing Foraminifera Pararotalia into the Eastern Mediterranean Facilitated by the Ongoing Warming Trend.

    PubMed

    Schmidt, Christiane; Morard, Raphael; Almogi-Labin, Ahuva; Weinmann, Anna E; Titelboim, Danna; Abramovich, Sigal; Kucera, Michal

    2015-01-01

    , our results indicate that continued warming of the eastern Mediterranean will facilitate the invasion of more tropical marine taxa into the Mediterranean, disturbing local biodiversity and ecosystem structure.

  20. Recent Invasion of the Symbiont-Bearing Foraminifera Pararotalia into the Eastern Mediterranean Facilitated by the Ongoing Warming Trend

    PubMed Central

    Schmidt, Christiane; Morard, Raphael; Almogi-Labin, Ahuva; Weinmann, Anna E.; Titelboim, Danna; Abramovich, Sigal; Kucera, Michal

    2015-01-01

    , our results indicate that continued warming of the eastern Mediterranean will facilitate the invasion of more tropical marine taxa into the Mediterranean, disturbing local biodiversity and ecosystem structure. PMID:26270964

  1. Invasive Fire Ants Reduce Reproductive Success and Alter the Reproductive Strategies of a Native Vertebrate Insectivore

    PubMed Central

    Ligon, Russell A.; Siefferman, Lynn; Hill, Geoffrey E.

    2011-01-01

    Background Introduced organisms can alter ecosystems by disrupting natural ecological relationships. For example, red imported fire ants (Solenopsis invicta) have disrupted native arthropod communities throughout much of their introduced range. By competing for many of the same food resources as insectivorous vertebrates, fire ants also have the potential to disrupt vertebrate communities. Methodology/Principal Findings To explore the effects of fire ants on a native insectivorous vertebrate, we compared the reproductive success and strategies of eastern bluebirds (Sialia sialis) inhabiting territories with different abundances of fire ants. We also created experimental dyads of adjacent territories comprised of one territory with artificially reduced fire ant abundance (treated) and one territory that was unmanipulated (control). We found that more bluebird young fledged from treated territories than from adjacent control territories. Fire ant abundance also explained significant variation in two measures of reproductive success across the study population: number of fledglings and hatching success of second clutches. Furthermore, the likelihood of bluebird parents re-nesting in the same territory was negatively influenced by the abundance of foraging fire ants, and parents nesting in territories with experimentally reduced abundances of fire ants produced male-biased broods relative to pairs in adjacent control territories. Conclusions/Significance Introduced fire ants altered both the reproductive success (number of fledglings, hatching success) and strategies (decision to renest, offspring sex-ratio) of eastern bluebirds. These results illustrate the negative effects that invasive species can have on native biota, including species from taxonomically distant groups. PMID:21799904

  2. Stealth predation and the predatory success of the invasive ctenophore Mnemiopsis leidyi.

    PubMed

    Colin, Sean P; Costello, John H; Hansson, Lars J; Titelman, Josefin; Dabiri, John O

    2010-10-01

    In contrast to higher metazoans such as copepods and fish, ctenophores are a basal metazoan lineage possessing a relatively narrow set of sensory-motor capabilities. Yet lobate ctenophores can capture prey at rates comparable to sophisticated predatory copepods and fish, and they are capable of altering the composition of coastal planktonic communities. Here, we demonstrate that the predatory success of the lobate ctenophore Mnemiopsis leidyi lies in its use of cilia to generate a feeding current that continuously entrains large volumes of fluid, yet is virtually undetectable to its prey. This form of stealth predation enables M. leidyi to feed as a generalist predator capturing prey, including microplankton (approximately 50 μm), copepods (approximately 1 mm), and fish larvae (>3 mm). The efficacy and versatility of this stealth feeding mechanism has enabled M. leidyi to be notoriously destructive as a predator and successful as an invasive species.

  3. Stealth predation and the predatory success of the invasive ctenophore Mnemiopsis leidyi

    PubMed Central

    Colin, Sean P.; Costello, John H.; Hansson, Lars J.; Titelman, Josefin; Dabiri, John O.

    2010-01-01

    In contrast to higher metazoans such as copepods and fish, ctenophores are a basal metazoan lineage possessing a relatively narrow set of sensory-motor capabilities. Yet lobate ctenophores can capture prey at rates comparable to sophisticated predatory copepods and fish, and they are capable of altering the composition of coastal planktonic communities. Here, we demonstrate that the predatory success of the lobate ctenophore Mnemiopsis leidyi lies in its use of cilia to generate a feeding current that continuously entrains large volumes of fluid, yet is virtually undetectable to its prey. This form of stealth predation enables M. leidyi to feed as a generalist predator capturing prey, including microplankton (approximately 50 μm), copepods (approximately 1 mm), and fish larvae (>3 mm). The efficacy and versatility of this stealth feeding mechanism has enabled M. leidyi to be notoriously destructive as a predator and successful as an invasive species. PMID:20855619

  4. Transposable element islands facilitate adaptation to novel environments in an invasive species.

    PubMed

    Schrader, Lukas; Kim, Jay W; Ence, Daniel; Zimin, Aleksey; Klein, Antonia; Wyschetzki, Katharina; Weichselgartner, Tobias; Kemena, Carsten; Stökl, Johannes; Schultner, Eva; Wurm, Yannick; Smith, Christopher D; Yandell, Mark; Heinze, Jürgen; Gadau, Jürgen; Oettler, Jan

    2014-01-01

    Adaptation requires genetic variation, but founder populations are generally genetically depleted. Here we sequence two populations of an inbred ant that diverge in phenotype to determine how variability is generated. Cardiocondyla obscurior has the smallest of the sequenced ant genomes and its structure suggests a fundamental role of transposable elements (TEs) in adaptive evolution. Accumulations of TEs (TE islands) comprising 7.18% of the genome evolve faster than other regions with regard to single-nucleotide variants, gene/exon duplications and deletions and gene homology. A non-random distribution of gene families, larvae/adult specific gene expression and signs of differential methylation in TE islands indicate intragenomic differences in regulation, evolutionary rates and coalescent effective population size. Our study reveals a tripartite interplay between TEs, life history and adaptation in an invasive species.

  5. Transposable element islands facilitate adaptation to novel environments in an invasive species.

    PubMed

    Schrader, Lukas; Kim, Jay W; Ence, Daniel; Zimin, Aleksey; Klein, Antonia; Wyschetzki, Katharina; Weichselgartner, Tobias; Kemena, Carsten; Stökl, Johannes; Schultner, Eva; Wurm, Yannick; Smith, Christopher D; Yandell, Mark; Heinze, Jürgen; Gadau, Jürgen; Oettler, Jan

    2014-01-01

    Adaptation requires genetic variation, but founder populations are generally genetically depleted. Here we sequence two populations of an inbred ant that diverge in phenotype to determine how variability is generated. Cardiocondyla obscurior has the smallest of the sequenced ant genomes and its structure suggests a fundamental role of transposable elements (TEs) in adaptive evolution. Accumulations of TEs (TE islands) comprising 7.18% of the genome evolve faster than other regions with regard to single-nucleotide variants, gene/exon duplications and deletions and gene homology. A non-random distribution of gene families, larvae/adult specific gene expression and signs of differential methylation in TE islands indicate intragenomic differences in regulation, evolutionary rates and coalescent effective population size. Our study reveals a tripartite interplay between TEs, life history and adaptation in an invasive species. PMID:25510865

  6. Butorphanol premedication to facilitate invasive monitoring in cardiac surgery patients before induction of anaesthesia.

    PubMed

    Tripathi, Mukesh; Nath, Soumya Shanker; Banerjee, Sudipto; Tripathi, Mamta

    2009-01-01

    Cannulations (peripheral vein, radial artery and jugular vein) performed for invasive monitoring before induction of anaesthesia in cardiac surgery patients may be associated with stress and anxiety. The efficacy and safety of butorphanol premedication was assessed in setting up of invasive monitoring. The study was a prospective, randomized, double blind, placebo controlled one with 70 patients undergoing elective cardiac surgery. In group-1 patients (n = 35) (placebo) intramuscular saline was administered 1-2 hours before the surgery in equivalent volume to butorphanol. In group-2 (n = 35) butorphanol (1, 1.5 and 2 mg for three body weight groups < 40 kg, 41-60 kg and> 60 kg, respectively) was administered 1-2 hours before surgery. Observer blinded for medication recorded the sedation score, pupil size and pain after each cannulation using visual analogue score (VAS). Student's 't' test and Chi-square test for proportions, Mann-Whitney test for non-parametric data was carried out. The median pain score of cannulation in group-2 (butorphanol) in the hand (10 mm) and neck (20 mm) were significantly (P < 0.05) lower than group-1 (placebo) patients (hand = 30 mm and neck = 40 mm). Pain during neck cannulation was significantly (P < 0.05) reduced (VAS < 30 mm) in patients with the pupil size of < 2.5 mm. Since the pain during neck cannulation was more than pain during hand cannulations in both the groups, we conclude that the intensity of pain depends also upon the site of cannulation. Besides the analgesic effect of butorphanol, its sedative effect helped to effectively decrease the pain during neck cannulation in conscious patients. PMID:19136753

  7. Facilitators: One Key Factor in Implementing Successful Experience-Based Training and Development Programs.

    ERIC Educational Resources Information Center

    Wagner, Richard J.; Roland, Christopher C.

    An increasing number of corporations are using some form of experience-based outdoor training and development. Most of these programs follow a general process that includes: (1) introduction of the activity by the facilitator; (2) the experiential activity (during which the facilitator is observer or safety monitor); and (3) debriefing or…

  8. Alien Plants Introduced by Different Pathways Differ in Invasion Success: Unintentional Introductions as a Threat to Natural Areas

    PubMed Central

    Pyšek, Petr; Jarošík, Vojtěch; Pergl, Jan

    2011-01-01

    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 threat to natural areas

  9. Prp19 facilitates invasion of hepatocellular carcinoma via p38 mitogen-activated protein kinase/Twist1 pathway

    PubMed Central

    Zhu, Ji-Min; Yu, Qian; Xue, Ru-Yi; Fang, Ying; Zhang, Yi-An; Chen, Yan-Jie; Liu, Tao-Tao; Dong, Ling; Shen, Xi-Zhong

    2016-01-01

    Pre-mRNA processing factor 19 (Prp19) is involved in many cellular events including pre-mRNA processing and DNA damage response. However, the pathological role of Prp19 in hepatocellular carcinoma (HCC) is still elusive. Here, we reported that Prp19 was increased in most HCC tissues and HCC cell lines, and its overexpression in HCC tissues was positively correlated with vascular invasion, tumor capsule breakthrough and poor prognosis. Prp19 potentiated migratory and invasive abilities of HCC cells in vitro and in vivo. Furthermore Prp19 facilitated Twist1-induced epithelial-mesenchymal transition. Mechanistic insights revealed that Prp19 directly binded with TGF-β-activated kinase1 (TAK1) and promoted the activation of p38 mitogen-activated protein kinase (MAPK), preventing Twist1 from degradation. Finally Prp19/p38 MAPK/Twist1 axis was attested in nude mice xenografts and HCC patient specimens. This work implies that the gain of Prp19 is a critical event during the progression of HCC, making it a promising target for malignancies with aberrant Prp19 expression. PMID:26959880

  10. Moving from "Things to Do on Monday" to Student Learning: Physical Education Professional Development Facilitators' Views of Success

    ERIC Educational Resources Information Center

    Patton, Kevin; Parker, Melissa

    2014-01-01

    Background: Facilitation within successful professional development (PD) requires individuals working with a cadre of teachers to examine and reframe their practices, navigating the complexities associated with educational reform initiatives. Although much has been written about the magnitude of the shift required of teachers within current…

  11. Phylodynamics analysis of canine parvovirus in Uruguay: evidence of two successive invasions by different variants.

    PubMed

    Maya, Leticia; Calleros, Lucía; Francia, Lourdes; Hernández, Martín; Iraola, Gregorio; Panzera, Yanina; Sosa, Katia; Pérez, Ruben

    2013-06-01

    Canine parvovirus (CPV) comprises three antigenic variants (2a, 2b, and 2c) with different frequencies and genetic variability among countries. Current CPV populations are considered to be spatially structured with relatively little movement of viruses between geographical areas. Here we describe the evolution and population dynamics of CPV in Uruguay from 2006-2011 using full-length capsid viral protein 2 (VP2) sequences. CPV-2c was the predominant variant in Uruguay for 4 years (2006-2009). The estimated time to the most recent common ancestor suggested that the CPV-2c variant appeared in Uruguay around 2004-2005. Comparative phylogenetic analysis revealed that South American CPV-2c strains did not emerge de novo but may have a European origin. In 2010, a remarkable epidemiological change occurred as a consequence of the emergence of a novel CPV-2a strain in the previously homogeneous CPV-2c population. The frequency of the novel CPV-2a strain increased to 85 % in 2011, representing the first example of a CPV-2a strain replacing a predominant CPV-2c strain in a dog population. The CPV-2a strains detected in 2010-2011 were not phylogenetically related to any other strain collected on the American continent but were identical to Asiatic strains, suggesting that its emergence was a consequence of a migration event. Taken together, our findings suggest that in the last decade, Uruguay has experienced two successive invasions by CPV-2c and CPV-2a variants of European and Asiatic origins, respectively. These results support the hypothesis that CPV invasion events are not rare in certain geographic regions and indicate that some current strains may exhibit an unexpectedly high invasion and replacement capability.

  12. Invasion of an exotic forb impacts reproductive success and site fidelity of a migratory songbird.

    PubMed

    Ortega, Yvette Katina; McKelvey, Kevin Scot; Six, Diana Lee

    2006-08-01

    Although exotic plant invasions threaten natural systems worldwide, we know little about the specific ecological impacts of invaders, including the magnitude of effects and underlying mechanisms. Exotic plants are likely to impact higher trophic levels when they overrun native plant communities, affecting habitat quality for breeding songbirds by altering food availability and/or nest predation levels. We studied chipping sparrows (Spizella passerina) breeding in savannas that were either dominated by native vegetation or invaded by spotted knapweed (Centaurea maculosa), an exotic forb that substantially reduces diversity and abundance of native herbaceous plant species. Chipping sparrows primarily nest in trees but forage on the ground, consuming seeds and arthropods. We found that predation rates did not differ between nests at knapweed and native sites. However, initiation of first nests was delayed at knapweed versus native sites, an effect frequently associated with low food availability. Our seasonal fecundity model indicated that breeding delays could translate to diminished fecundity, including dramatic declines in the incidence of double brooding. Site fidelity of breeding adults was also substantially reduced in knapweed compared to native habitats, as measured by return rates and shifts in territory locations between years. Declines in reproductive success and site fidelity were greater for yearling versus older birds, and knapweed invasion appeared to exacerbate differences between age classes. In addition, grasshoppers, which represent an important prey resource, were substantially reduced in knapweed versus native habitats. Our results strongly suggest that knapweed invasion can impact chipping sparrow populations by reducing food availability. Food chain effects may be an important mechanism by which strong plant invaders impact songbirds and other consumers.

  13. Multitrophic interaction facilitates parasite–host relationship between an invasive beetle and the honey bee

    PubMed Central

    Torto, Baldwyn; Boucias, Drion G.; Arbogast, Richard T.; Tumlinson, James H.; Teal, Peter E. A.

    2007-01-01

    Colony defense by honey bees, Apis mellifera, is associated with stinging and mass attack, fueled by the release of alarm pheromones. Thus, alarm pheromones are critically important to survival of honey bee colonies. Here we report that in the parasitic relationship between the European honey bee and the small hive beetle, Aethina tumida, the honey bee's alarm pheromones serve a negative function because they are potent attractants for the beetle. Furthermore, we discovered that the beetles from both Africa and the United States vector a strain of Kodamaea ohmeri yeast, which produces these same honey bee alarm pheromones when grown on pollen in hives. The beetle is not a pest of African honey bees because African bees have evolved effective methods to mitigate beetle infestation. However, European honey bees, faced with disease and pest management stresses different from those experienced by African bees, are unable to effectively inhibit beetle infestation. Therefore, the environment of the European honey bee colony provides optimal conditions to promote the unique bee–beetle–yeast–pollen multitrophic interaction that facilitates effective infestation of hives at the expense of the European honey bee. PMID:17483478

  14. Successful pneumonectomy for invasive pulmonary aspergillosis and advanced non-small cell-lung cancer.

    PubMed

    Minesaki, Shohei; Koyama, Nobuyuki; Ishida, Hironori; Kobayashi, Kunihiko

    2013-01-01

    Aspergillus spp. is a pathogenic fungus in patients with malignancy, immunosuppression or respiratory diseases, and invasive pulmonary aspergillosis (IPA) caused by its infection is an aggressive and often lethal disorder. We report a case of non-small-cell lung cancer (NSCLC) where pneumonectomy concomitantly enabled radical cure of the underlying disease and IPA against which different antifungal drugs had been ineffective. In a patient with locally advanced NSCLC that progressed despite chemoradiation, radiation pneumonitis and subsequently cavitary disease developed following the administration of corticosteroids. Based upon the isolation of Aspergillus spp. from sputum, a diagnosis of IPA was made and since the latter was refractory to multiple antifungal drugs, pneumonectomy was undertaken which resulted in successful treatment of both NSCLC and IPA. Surgical intervention should be considered as a therapeutic option for IPA complicating NSCLC that is refractory to medical management. PMID:23505081

  15. Bottom-up control of consumers leads to top-down indirect facilitation of invasive annual herbs in semiarid Chile.

    PubMed

    Madrigal, Jaime; Kelt, Douglas A; Meserve, Peter L; Gutierrez, Julio R; Squeo, Francisco A

    2011-02-01

    The abundance of exotic plants is thought to be limited by competition with resident species (including plants and generalist herbivores). In contrast, observations in semiarid Chile suggest that a native generalist rodent, the degu (Octodon degus), may be facilitating the expansion of exotic annual plants. We tested this hypothesis with a 20-year data set from a World Biosphere Reserve in mediterranean Chile. In this semiarid environment, rainfall varies annually and dramatically influences cover by both native and exotic annual plants; degu population density affects the composition and cover of exotic and native annual plants. In low-rainfall years, cover of both native and exotic herbs is extremely low. Higher levels of precipitation result in proportional increases in cover of all annual plants (exotic and native species), leading in turn to increases in degu population densities, at which point they impact native herbs in proportion to their greater cover, indirectly favoring the expansion of exotic plants. We propose that bottom-up control of consumers at our site results in top-down indirect facilitation of invasive annual herbs, and that this pattern may be general to other semiarid ecosystems. PMID:21618907

  16. Non-invasive brain stimulation can induce paradoxical facilitation. Are these neuroenhancements transferable and meaningful to security services?

    PubMed Central

    Levasseur-Moreau, Jean; Brunelin, Jerome; Fecteau, Shirley

    2013-01-01

    For ages, we have been looking for ways to enhance our physical and cognitive capacities in order to augment our security. One potential way to enhance our capacities may be to externally stimulate the brain. Methods of non-invasive brain stimulation (NIBS), such as repetitive transcranial magnetic stimulation (rTMS) and transcranial electrical stimulation (tES), have been recently developed to modulate brain activity. Both techniques are relatively safe and can transiently modify motor and cognitive functions outlasting the stimulation period. The purpose of this paper is to review data suggesting that NIBS can enhance motor and cognitive performance in healthy volunteers. We frame these findings in the context of whether they may serve security purposes. Specifically, we review studies reporting that NIBS induces paradoxical facilitation in motor (precision, speed, strength, acceleration endurance, and execution of daily motor task) and cognitive functions (attention, impulsive behavior, risk-taking, working memory, planning, and deceptive capacities). Although transferability and meaningfulness of these NIBS-induced paradoxical facilitations into real-life situations are not clear yet, NIBS may contribute at improving training of motor and cognitive functions relevant for military, civil, and forensic security services. This is an enthusiastic perspective that also calls for fair and open debates on the ethics of using NIBS in healthy individuals to enhance normal functions. PMID:23966923

  17. Invasive aspergillosis successfully treated by combined antifungal therapy and immunosuppressive monotherapy two months following heart transplantation

    PubMed Central

    Żabicki, Bartłomiej; Baszyńska-Wachowiak, Hanna; Straburzyńska-Migaj, Ewa; Juszkat, Robert; Grajek, Stefan; Jemielity, Marek

    2016-01-01

    Invasive aspergillosis is becoming increasingly prevalent, especially following transplantation. Invasive aspergillosis is associated with mortality. Successful therapy is related to early diagnosis and proper therapy. We present the case of a 61-year-old man suffering from invasive aspergillosis 2 months following heart transplantation. He was suffering from hypertrophic cardiomyopathy and he underwent orthotropic heart transplantation. He was readmitted to the Department of Cardiology 69 days following transplantation due to symptoms of productive cough for 5 days. It was accompanied by chest pain, shortness of breath, and fever up to 39°C. He was slightly cyanotic and confused on physical examination. The patient's status deteriorated within the following 2 days. On bronchoscopic specimen examinations Aspergillus mould filaments were detected and the serum galactomannan index was 12.162. His blood saturation decreased to 85%. C-reactive protein serum level increased to 273 mg/l. The patient was admitted to the intensive care unit and intubated due to severe respiratory insufficiency. Computed tomography revealed massive, mostly homogeneous consolidation. The patient was treated with 200 mg of voriconazole and 50 mg of caspofungin daily. Caspofungin therapy was continued for 23 days and voriconazole was administered parenterally for 62 days. Voriconazole therapy was continued orally for 9 months. During combined antifungal therapy, the galactomannan serum index constantly decreased from 12.1 to 0.33 (end-point of caspofungin therapy) and to 0.23 (end-point of voriconazole parenteral administration). His immunosuppressive therapy was limited to calcineurin inhibitor (tacrolimus) monotherapy. Post-treatment imaging 9 months after diagnosis confirmed the efficacy of therapy as a lack of pulmonary infiltration associated with left apical peribronchial scarring as a result of treatment. The present case proved the efficiency of combined (voriconazole and caspofungin

  18. Invasive aspergillosis successfully treated by combined antifungal therapy and immunosuppressive monotherapy two months following heart transplantation.

    PubMed

    Urbanowicz, Tomasz; Żabicki, Bartłomiej; Baszyńska-Wachowiak, Hanna; Straburzyńska-Migaj, Ewa; Juszkat, Robert; Grajek, Stefan; Jemielity, Marek

    2016-06-01

    Invasive aspergillosis is becoming increasingly prevalent, especially following transplantation. Invasive aspergillosis is associated with mortality. Successful therapy is related to early diagnosis and proper therapy. We present the case of a 61-year-old man suffering from invasive aspergillosis 2 months following heart transplantation. He was suffering from hypertrophic cardiomyopathy and he underwent orthotropic heart transplantation. He was readmitted to the Department of Cardiology 69 days following transplantation due to symptoms of productive cough for 5 days. It was accompanied by chest pain, shortness of breath, and fever up to 39°C. He was slightly cyanotic and confused on physical examination. The patient's status deteriorated within the following 2 days. On bronchoscopic specimen examinations Aspergillus mould filaments were detected and the serum galactomannan index was 12.162. His blood saturation decreased to 85%. C-reactive protein serum level increased to 273 mg/l. The patient was admitted to the intensive care unit and intubated due to severe respiratory insufficiency. Computed tomography revealed massive, mostly homogeneous consolidation. The patient was treated with 200 mg of voriconazole and 50 mg of caspofungin daily. Caspofungin therapy was continued for 23 days and voriconazole was administered parenterally for 62 days. Voriconazole therapy was continued orally for 9 months. During combined antifungal therapy, the galactomannan serum index constantly decreased from 12.1 to 0.33 (end-point of caspofungin therapy) and to 0.23 (end-point of voriconazole parenteral administration). His immunosuppressive therapy was limited to calcineurin inhibitor (tacrolimus) monotherapy. Post-treatment imaging 9 months after diagnosis confirmed the efficacy of therapy as a lack of pulmonary infiltration associated with left apical peribronchial scarring as a result of treatment. The present case proved the efficiency of combined (voriconazole and caspofungin

  19. On mixed reality environments for minimally invasive therapy guidance: systems architecture, successes and challenges in their implementation from laboratory to clinic.

    PubMed

    Linte, Cristian A; Davenport, Katherine P; Cleary, Kevin; Peters, Craig; Vosburgh, Kirby G; Navab, Nassir; Edwards, Philip Eddie; Jannin, Pierre; Peters, Terry M; Holmes, David R; Robb, Richard A

    2013-03-01

    Mixed reality environments for medical applications have been explored and developed over the past three decades in an effort to enhance the clinician's view of anatomy and facilitate the performance of minimally invasive procedures. These environments must faithfully represent the real surgical field and require seamless integration of pre- and intra-operative imaging, surgical instrument tracking, and display technology into a common framework centered around and registered to the patient. However, in spite of their reported benefits, few mixed reality environments have been successfully translated into clinical use. Several challenges that contribute to the difficulty in integrating such environments into clinical practice are presented here and discussed in terms of both technical and clinical limitations. This article should raise awareness among both developers and end-users toward facilitating a greater application of such environments in the surgical practice of the future.

  20. On mixed reality environments for minimally invasive therapy guidance: Systems architecture, successes and challenges in their implementation from laboratory to clinic

    PubMed Central

    Linte, Cristian A.; Davenport, Katherine P.; Cleary, Kevin; Peters, Craig; Vosburgh, Kirby G.; Navab, Nassir; Edwards, Philip “Eddie”; Jannin, Pierre; Peters, Terry M.; Holmes, David R.; Robb, Richard A.

    2013-01-01

    Mixed reality environments for medical applications have been explored and developed over the past three decades in an effort to enhance the clinician’s view of anatomy and facilitate the performance of minimally invasive procedures. These environments must faithfully represent the real surgical field and require seamless integration of pre- and intra-operative imaging, surgical instrument tracking, and display technology into a common framework centered around and registered to the patient. However, in spite of their reported benefits, few mixed reality environments have been successfully translated into clinical use. Several challenges that contribute to the difficulty in integrating such environments into clinical practice are presented here and discussed in terms of both technical and clinical limitations. This article should raise awareness among both developers and end-users toward facilitating a greater application of such environments in the surgical practice of the future. PMID:23632059

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

    NASA Astrophysics Data System (ADS)

    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

  2. Causes and effects of a highly successful marine invasion: Case-study of the introduced Pacific oyster Crassostrea gigas in continental NW European estuaries

    NASA Astrophysics Data System (ADS)

    Troost, Karin

    2010-10-01

    Since the 1960's, the Pacific oyster Crassostrea gigas has been introduced for mariculture at several locations within NW Europe. The oyster established itself everywhere and expanded rapidly throughout the receiving ecosystems, forming extensive and dense reef structures. It became clear that the Pacific oyster induced major changes in NW European estuaries. This paper reviews the causes of the Pacific oyster's remarkably successful establishment and spread in The Netherlands and neighbouring countries, and includes a comprehensive review of consequences for the receiving communities. Ecosystem engineering by C. gigas and a relative lack of natural enemies in receiving ecosystems are identified as the most important characteristics facilitating the invader's successful establishment and expansion. The Pacific oyster's large filtration capacity and eco-engineering characteristics induced many changes in receiving ecosystems. Different estuaries are affected differently; in the Dutch Oosterschelde estuary expanding stocks saturate the carrying capacity whereas in the Wadden Sea no such problems exist. In general, the Pacific oyster seems to fit well within continental NW European estuarine ecosystems and there is no evidence that the invader outcompetes native bivalves. C. gigas induces changes in plankton composition, habitat heterogeneity and biodiversity, carrying capacity, food webs and parasite life cycles. The case of the Pacific oyster in NW European estuaries is only one example in an increasing series of biological invasions mediated by human activities. This case-study will contribute to further elucidating general mechanisms in marine invasions; invasions that sometimes appear a threat, but can also contribute to ecological complexity.

  3. The Single Parent Family: A Challenge for Parents. Successful Parenting. Facilitator's Guide. Part Seven.

    ERIC Educational Resources Information Center

    Taylor, Barbara Lynn

    Intended for parent educators, this facilitator's guide outlines a workshop for single parents to help them meet the challenges of raising children alone. The guide first presents frameworks for a 1- or 2-hour workshop and for an 8-session workshop. The remainder of the guide corresponds to a 28-minute companion video, presenting questions for…

  4. The Shared Experiences: Facilitating Successful Transfer of Women and Underrepresented Minorities in STEM Fields

    ERIC Educational Resources Information Center

    Jackson, Dimitra Lynette; Starobin, Soko S.; Laanan, Frankie Santos

    2013-01-01

    This chapter addresses critical issues related to the transfer success of women and underrepresented minorities (URMs) in STEM disciplines and will highlight implications for fostering a successful transfer experience for these populations. For the purposes of this chapter, URMs is defined by the National Science Foundation to include African…

  5. Double-layered collagen gel hemisphere for cell invasion assay: successful visualization and quantification of cell invasion activity.

    PubMed

    Takata, Masahiko; Maniwa, Yoshimasa; Doi, Takefumi; Tanaka, Yugo; Okada, Kenji; Nishio, Wataru; Ohbayashi, Chiho; Yoshimura, Masahiro; Hayashi, Yoshitake; Okita, Yutaka

    2007-10-01

    Although various methods for collagen gel-based cell invasion assays have been described, there continues to be a need for a simpler and more objective assay. Here, we describe an easy-to-prepare double-layered collagen gel hemisphere (DL-CGH) system that satisfies these requirements, and we demonstrate the advantages of this new system for visualizing cell movements during invasion. DL-CGH consists of a central core collagen layer surrounded by an outer cover collagen layer. A droplet of collagen I solution (containing cells to be examined) naturally forms a small hemisphere on the bottom of the culture dish. After this central core layer gels, a second droplet is placed atop the first gel, encapsulating it completely. The hemisphere is submerged in the medium and cultured. The invasive activity of cells that infiltrate from the inner to the outer layer can be evaluated optically. Using this in vitro system, we measured the inhibitory effect of E-cadherin expression on cancer cell invasion. DL-CGH also allowed visualization of interactions between invading cancer cells and the stroma. Cancer cells, which lack the proteases required for direct entrance into the three-dimensional collagen matrix, were seen to slip like amoebas through matrix gaps generated by the pericellular proteolytic activity of fibroblasts. [Supplementary materials are available for this article. Go to the publisher's online edition of Cell Communication and Adhesion for the following free supplemental resources: Movies 1-3; 4a and b]. PMID:17957531

  6. Unravelling the Paradox of Loss of Genetic Variation during Invasion: Superclones May Explain the Success of a Clonal Invader

    PubMed Central

    Caron, Valerie; Ede, Fiona J.; Sunnucks, Paul

    2014-01-01

    Clonality is a common characteristic of successful invasive species, but general principles underpinning the success of clonal invaders are not established. A number of mechanisms could contribute to invasion success including clones with broad tolerances and preferences, specialist clones and adaptation in situ. The majority of studies to date have been of plants and some invertebrate parthenogens, particularly aphids, and have not necessarily caught invasion at very early stages. Here we describe the early stages of an invasion by a Northern Hemisphere Hymenopteran model in three different land masses in the Southern Hemisphere. Nematus oligospilus Förster (Hymenoptera: Tenthredinidae), a sawfly feeding on willows (Salix spp.), was recently introduced to the Southern Hemisphere where it has become invasive and is strictly parthenogenetic. In this study, the number of N. oligospilus clones, their distribution in the landscape and on different willow hosts in South Africa, New Zealand and Australia were assessed using 25 microsatellite markers. Evidence is presented for the presence of two very common and widespread multilocus genotypes (MLGs) or ‘superclones’ dominating in the three countries. Rarer MLGs were closely related to the most widespread superclone; it is plausible that all N. oligospilus individuals were derived from a single clone. A few initial introductions to Australia and New Zealand seemed to have occurred. Our results point towards a separate introduction in Western Australia, potentially from South Africa. Rarer clones that were dominant locally putatively arose in situ, and might be locally favoured, or simply have not yet had time to spread. Data presented represent rare baseline data early in the invasion process for insights into the mechanisms that underlie the success of a global invader, and develop Nematus oligospilus as a valuable model to understand invasion genetics of clonal pests. PMID:24914550

  7. Successful treatment of rare-earth magnet ingestion via minimally invasive techniques: a case series.

    PubMed

    Kosut, Jessica S; Johnson, Sidney M; King, Jeremy L; Garnett, Gwendolyn; Woo, Russell K

    2013-04-01

    Cases of rare-earth magnet ingestions have been increasingly reported in the literature. However, these descriptions have focused on the severity of the injuries, rather than the clinical presentation and/or therapeutic approach. We report a series of eight children, ranging in age from 2 to 10 years, who ingested powerful rare-earth magnets. The rare-earth magnets were marketed in 2009 under the trade name Buckyballs(®) (Maxfield & Oberton, New York, NY). They are about 5 mm in size, spherical, and brightly colored, making them appealing for young children to play with and place in their mouths. Three children presented within hours of ingestion, and the magnets were successfully removed via endoscopy in two, whereas the third child required laparoscopy. No fistulas were found in these children. A fourth child presented 2 days after ingestion with evidence of bowel wall erosion, but without fistula formation; the magnets were removed via laparoscopy. A fifth child ingested nine magnets in a ring formation, which were removed via colonoscopy without evidence of injury or fistula formation. The three remaining children presented late (5-8 days after ingestion) and were found to have associated fistulas. They were treated successfully with a combination of endoscopy and laparoscopy with fluoroscopy. None of the children in our series required an open surgical procedure. All children were discharged home without complications. This case series highlights the potential dangers of rare-earth magnet ingestion in children. Our experience suggests that prompt intervention using minimally invasive approaches can lead to successful outcomes.

  8. Patchiness and Co-Existence of Indigenous and Invasive Mussels at Small Spatial Scales: The Interaction of Facilitation and Competition

    PubMed Central

    Erlandsson, Johan; McQuaid, Christopher D.; Sköld, Martin

    2011-01-01

    Ecological theory predicts that two species with similar requirements will fail to show long-term co-existence in situations where shared resources are limiting, especially at spatial scales that are small relative to the size of the organisms. Two species of intertidal mussels, the indigenous Perna perna and the invasive Mytilus galloprovincialis, form mixed beds on the south coast of South Africa in a situation that has been stable for several generations of these species, even though these populations are often limited by the availability of space. We examined the spatial structure of these species where they co-exist at small spatial scales in the absence of apparent environmental heterogeneity at two sites, testing: whether conspecific aggregation of mussels can occur (using spatial Monte-Carlo tests); the degree of patchiness (using Korcak B patchiness exponent), and whether there was a relationship between percent cover and patchiness. We found that under certain circumstances there is non-random conspecific aggregation, but that in other circumstances there may be random distribution (i.e. the two species are mixed), so that spatial patterns are context-dependent. The relative cover of the species differed between sites, and within each site, the species with higher cover showed low Korcak B values (indicating low patchiness, i.e. the existence of fewer, larger patches), while the less abundant species showed the reverse, i.e. high patchiness. This relationship did not hold for either species within sites. We conclude that co-existence between these mussels is possible, even at small spatial scales because each species is an ecological engineer and, while they have been shown to compete for space, this is preceded by initial facilitation. We suggest that a patchy pattern of co-existence is possible because of a balance between direct (competitive) and indirect (facilitative) interactions. PMID:22132084

  9. Provisional Admission Practices: Blending Access and Support to Facilitate Student Success

    ERIC Educational Resources Information Center

    Nichols, Andrew Howard; Clinedinst, Melissa

    2013-01-01

    This report examines provisional admission as an initiative that can expand four-year college access and success for students from economically disadvantaged backgrounds. Provisional admission policies and programs enable students to enroll at an institution under specific conditions. Students are often required to meet certain academic…

  10. Facilitating Primary Head Teacher Succession in England: The Role of the School Business Manager

    ERIC Educational Resources Information Center

    Woods, Charlotte; Armstrong, Paul; Pearson, Diana

    2012-01-01

    School leadership is significant for student learning, but increased workload and complexity are believed to be in part responsible for the difficulties internationally in managing succession, with experienced leaders leaving the profession prematurely and potential future leaders reluctant to take on the role. This article draws on a national…

  11. Know when to run, know when to hide: can behavioral differences explain the divergent invasion success of two sympatric lizards?

    PubMed Central

    Chapple, David G; Simmonds, Sarah M; Wong, Bob BM

    2011-01-01

    Invasive species represent a select subset of organisms that have successfully transitioned through each stage of the introduction process (transportation, establishment, and spread). Although there is a growing realization that behavior plays a critical role in invasion success, few studies have focused on the initial stages of introduction. We examined whether differences in the grouping tendencies and exploratory behavior of two sympatric lizard species could contribute to their divergent invasion success. While the nondirected activity of the two species did not differ, the invasive delicate skink (Lampropholis delicata) was found to be more exploratory than the congeneric noninvasive garden skink (L. guichenoti), which enabled it to more effectively locate novel environments and basking site resources. The delicate skink also exhibited a greater tendency to hide, which may act to enhance its probability of ensnarement in freight and cargo and decrease its likelihood of detection during transit. The grouping tendencies of the two species did not differ. Together, our results suggest that while the two species have an equivalent “opportunity” for unintentional human-assisted transportation, several pre-existing behavioral traits may enhance the success of the delicate skink in negotiating the initial stages of the introduction process, and subsequent post-establishment spread. PMID:22393500

  12. Critical dosimetry measures and surrogate tools that can facilitate clinical success in PDT (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Pogue, Brian W.; Davis, Scott C.; Kanick, Stephen C.; Maytin, Edward V.; Pereira, Stephen P.; Palanisami, Akilan; Hasan, Tayyaba

    2016-03-01

    Photodynamic therapy can be a highly complex treatment with more than one parameter to control, or in some cases it is easily implemented with little control other than prescribed drug and light values. The role of measured dosimetry as related to clinical adoption has not been as successful as it could have been, and part of this may be from the conflicting goals of advocating for as many measurements as possible for accurate control, versus companies and clinical adopters advocating for as few measurements as possible, to keep it simple. An organized approach to dosimetry selection is required, which shifts from mechanistic measurements in pre-clinical and early phase I trials, towards just those essential dose limiting measurements and a focus on possible surrogate measures in phase II/III trials. This essential and surrogate approach to dosimetry should help successful adoption of clinical PDT if successful. The examples of essential dosimetry points and surrogate dosimetry tools which might be implemented in phase II and higher trials are discussed for solid tissue PDT with verteporfin and skin lesion treatment with aminolevulinc acid.

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

    PubMed

    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. PMID:26668717

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

    PubMed

    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.

  15. Intercontinental chemical variation in the invasive ant Wasmannia auropunctata (Roger) (Hymenoptera Formicidae): a key to the invasive success of a tramp species

    NASA Astrophysics Data System (ADS)

    Errard, Christine; Delabie, Jacques; Jourdan, Hervé; Hefetz, Abraham

    2005-07-01

    Unicoloniality emerges as a feature that characterizes successful invasive species. Its underlying mechanism is reduced intraspecific aggression while keeping interspecific competitiveness. To that effect, we present here a comparative behavioural and chemical study of the invasive ant Wasmannia auropunctata in parts of its native and introduced ranges. We tested the hypothesis that introduced populations (New Caledonia archipelago) have reduced intraspecific aggression relative to native populations (e.g., Ilhéus area, Brazil) and that this correlates with reduced variability in cuticular hydrocarbons (CHCs). As predicted, there was high intraspecific aggression in the Brazilian populations, but no intraspecific aggression among the New Caledonian populations. However, New Caledonian worker W. auropunctata remained highly aggressive towards ants of other invasive species. The chemical data corresponded with the behaviour. While CHCs of ants from the regions of Brazil diverged, the profiles of ants from various localities in New Caledonia showed high uniformity. We suggest that in New Caledonia W. auropunctata appears to behave as a single supercolony, whereas in its native range it acts as a multicolonial species. The uniformity of recognition cues in the New Caledonia ants may reflect a process whereby recognition alleles became fixed in the population, but may also be the consequence of a single introduction event and subsequent aggressive invasion of the ecosystem. Chemical uniformity coupled with low intraspecific but high interspecific aggression, lend credence to the latter hypothesis.

  16. Reproductive success by large, closely related males facilitated by sperm storage in an aggregate breeding amphibian.

    PubMed

    Chandler, C H; Zamudio, K R

    2008-03-01

    The outcome of sexual selection on males may depend on female mate choice and male-male competition as well as postcopulatory processes such as cryptic female choice and sperm competition. We studied the outcome of sexual selection in the spotted salamander (Ambystoma maculatum), specifically examining the role of body size and relatedness on male reproductive success. Using controlled mating experiments in the field, we gave females access to three males of different sizes. We used seven microsatellite loci to determine paternity in the resulting larvae, estimate relatedness (r) between females and their mates, and calculate md(2) (a measure of within-individual genomic divergence), heterozygosity, and standardized heterozygosity in the larvae. Both body size and relatedness to the female were significant predictors of male reproductive success. The relatedness of the males available to a female did not influence the amount of stored sperm she used to sire her larvae. Nonetheless, computer simulations showed that the average md(2), heterozygosity, and standardized heterozygosity of the offspring were lower than expected by random mating. These differences are due to the use of stored sperm to fertilize some eggs; md(2), heterozygosity, and standardized heterozygosity of larvae sired by stored sperm were significantly lower than those of larvae sired by the experimental males. These results suggest that relatedness may further influence a male's long-term reproductive success by determining whether his sperm is stored for later breeding seasons. Sexual selection in this salamander likely involves a complex interaction among many factors and may act over many seasons. PMID:18179431

  17. Morphological and Physiological Traits in the Success of the Invasive Plant Lespedeza Cuneata

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Invasive plants may use different strategies and mechanisms to become dominant in non native systems. To better understand the strategies and mechanisms of invading plants in tallgrass prairie, physiological and morphological characteristics of the invasive Lespedeza cuneata and native Ambrosia psi...

  18. Dissociable parietal regions facilitate successful retrieval of recently learned and personally familiar information.

    PubMed

    Elman, Jeremy A; Cohn-Sheehy, Brendan I; Shimamura, Arthur P

    2013-03-01

    In fMRI analyses, the posterior parietal cortex (PPC) is particularly active during the successful retrieval of episodic memory. To delineate the neural correlates of episodic retrieval more succinctly, we compared retrieval of recently learned spatial locations (photographs of buildings) with retrieval of previously familiar locations (photographs of familiar campus buildings). Episodic retrieval of recently learned locations activated a circumscribed region within the ventral PPC (anterior angular gyrus and adjacent regions in the supramarginal gyrus) as well as medial PPC regions (posterior cingulated gyrus and posterior precuneus). Retrieval of familiar locations activated more posterior regions in the ventral PPC (posterior angular gyrus, LOC) and more anterior regions in the medial PPC (anterior precuneus and retrosplenial cortex). These dissociable effects define more precisely PPC regions involved in the retrieval of recent, contextually bound information as opposed to regions involved in other processes, such as visual imagery, scene reconstruction, and self-referential processing.

  19. Can transgenerational plasticity contribute to the invasion success of annual plant species?

    PubMed

    Fenesi, Annamária; Dyer, Andrew R; Geréd, Júliánna; Sándor, Dorottya; Ruprecht, Eszter

    2014-09-01

    Adaptive transgenerational plasticity (TGP), i.e., significantly higher fitness when maternal and offspring conditions match, might contribute to the population growth of non-native species in highly variable environments. However, comparative studies that directly test this hypothesis are lacking. Therefore, we performed a reciprocal split-brood experiment to compare TGP in response to N and water availability in single populations of two invasive (Amaranthus retroflexus, Galinsoga parviflora) and two congeneric non-invasive introduced species (Amaranthus albus, Galinsoga ciliata). We hypothesized that the transgenerational effect is adaptive: (1) in invasive species compared with non-invasive adventives, and (2) in stressful conditions compared with resource-rich environments. The phenotypic variation among offspring was generated, in large part, by our experimental treatments in the maternal generation; therefore, we demonstrated a direct TGP effect on the offspring's adult fitness. We found evidence, for the first time, that invasive and non-invasive adventive species differ regarding the expression of TGP in the adult stage, as adaptive responses were found exclusively in the invasive species. The manifestation of TGP was more explicit under resource-rich conditions; therefore, it might contribute to the population dynamics of non-native species in resource-rich sites rather than to their ecological tolerance spectra.

  20. Abscisic acid in soil facilitates community succession in three forests in China.

    PubMed

    Zhao, Houben; Peng, Shaolin; Chen, Zhuoquan; Wu, Zhongmin; Zhou, Guangyi; Wang, Xu; Qiu, Zhijun

    2011-07-01

    Plants release secondary metabolites into the soil that change the chemical environment around them. Exogenous abscisic acid (ABA) is an important allelochemical whose role in successional trajectories has not been examined. We hypothesized that ABA can accumulate in the soil through successional processes and have an influence on forest dynamics. To this end, we investigated the distribution of ABA in forest communities from early to late successional stages and the response of dominant species to the gradient of ABA concentrations in three types of forests from northern to southern China. Concentrations of ABA in the soils of three forest types increased from early to late successional stages. Pioneer species' litters had the lowest ABA content, and their seed germination and seedling early growth were the most sensitive to the inhibitory effect of ABA. Mid- and late-successional species had a much higher ABA content in fallen leaves than pioneer species, and their seed germination and seedling early growth were inhibited by higher concentrations of ABA than pioneers. Late-successional species showed little response to the highest ABA concentration, possibly due to their large seed size. The results suggest that ABA accumulates in the soil as community succession proceeds. Sensitivity to ABA in the early stages, associated with other characteristics, may result in pioneer species losing their advantage in competition with late-successional species in an increasingly high ABA concentration environment, and being replaced by ABA-tolerant, late-successional species.

  1. Long-term scenarios of the invasive black cherry in pine-oak forest: Impact of regeneration success

    NASA Astrophysics Data System (ADS)

    Vanhellemont, Margot; Baeten, Lander; Verbeeck, Hans; Hermy, Martin; Verheyen, Kris

    2011-05-01

    The spread of invasive tree species in forests can be slow because of their long life span and the lag phases that may occur during the invasion process. Models of forest succession are a useful tool to explore how these invasive species might affect long-term forest development. We used the spatially explicit individual tree model SORTIE-ND to gain insight into the long-term development of a gap-dependent invasive tree species, Prunus serotina, in a pine-oak forest on sandy soil, the forest type in which P. serotina occurs most often in its introduced range. Forest inventory data, tree ring data, and photographs of the tree crowns were collected in a forest reserve in the Netherlands, characterized by high game densities. The collected data were then combined with data from literature to parameterize the model. We ran the model for two different scenarios in order to evaluate the impact of differences in the regeneration success of the native Quercus robur and the invasive P. serotina. The outcome of the simulations shows two differing courses of forest development. The invasive P. serotina became the dominant species when the regeneration of Q. robur was hindered, e.g., because of high herbivore densities. When both Q. robur and P. serotina were able to regenerate, Q. robur became the most abundant species in the long-term. We hypothesize that the relatively short life span of P. serotina may preclude its dominance if other long-lived tree species are present and able to regenerate.

  2. Facilitators and barriers to the successful implementation of a protocol to detect child abuse based on parental characteristics.

    PubMed

    Diderich, Hester M; Dechesne, Mark; Fekkes, Minne; Verkerk, Paul H; Pannebakker, Fieke D; Klein Velderman, Mariska; Sorensen, Peggy J G; Buitendijk, Simone E; Oudesluys-Murphy, Anne Marie

    2014-11-01

    To determine the critical facilitating and impeding factors underlying successful implementation of a method to detect child abuse based on parental rather than child characteristics known as the Hague Protocol. The original implementation region of the protocol (The Hague) was compared to a new implementation region (Friesland), using analysis of referrals, focus group interviews (n=6) at the Emergency departments (ED) and at the Reporting Centers for Child abuse and Neglect (RCCAN) as well as questionnaires (n=76) at the EDs. Implementation of the Hague Protocol substantially increased the number of referrals to the RCCAN in both regions. In Friesland, the new implementation region, the number of referrals increased from 2 out of 92,464 patients (three per 100,000) to 108 out of 167,037 patients (62 per 100,000). However in Friesland, child abuse was confirmed in a substantially lower percentage of cases relative to the initial implementation region (62% vs. 91%, respectively). Follow-up analyses suggest that this lower positive predictive value may be due to the lack of training for RCCAN professionals concerning the Hague Protocol. The focus group interviews and questionnaires point to time limitations as the main impediment for implementation, whereas an implementation coach has been mentioned as the most important facilitating factor for success. The Hague Protocol can be used to detect child abuse beyond the initial implementation region. However, training is essential in order to assure a consistent evaluation by the RCCAN. PMID:25192959

  3. Facilitators and barriers to the successful implementation of a protocol to detect child abuse based on parental characteristics.

    PubMed

    Diderich, Hester M; Dechesne, Mark; Fekkes, Minne; Verkerk, Paul H; Pannebakker, Fieke D; Klein Velderman, Mariska; Sorensen, Peggy J G; Buitendijk, Simone E; Oudesluys-Murphy, Anne Marie

    2014-11-01

    To determine the critical facilitating and impeding factors underlying successful implementation of a method to detect child abuse based on parental rather than child characteristics known as the Hague Protocol. The original implementation region of the protocol (The Hague) was compared to a new implementation region (Friesland), using analysis of referrals, focus group interviews (n=6) at the Emergency departments (ED) and at the Reporting Centers for Child abuse and Neglect (RCCAN) as well as questionnaires (n=76) at the EDs. Implementation of the Hague Protocol substantially increased the number of referrals to the RCCAN in both regions. In Friesland, the new implementation region, the number of referrals increased from 2 out of 92,464 patients (three per 100,000) to 108 out of 167,037 patients (62 per 100,000). However in Friesland, child abuse was confirmed in a substantially lower percentage of cases relative to the initial implementation region (62% vs. 91%, respectively). Follow-up analyses suggest that this lower positive predictive value may be due to the lack of training for RCCAN professionals concerning the Hague Protocol. The focus group interviews and questionnaires point to time limitations as the main impediment for implementation, whereas an implementation coach has been mentioned as the most important facilitating factor for success. The Hague Protocol can be used to detect child abuse beyond the initial implementation region. However, training is essential in order to assure a consistent evaluation by the RCCAN.

  4. Barriers and facilitators to successful transition from pediatric to adult inflammatory bowel disease care from the perspectives of providers

    PubMed Central

    Paine, Christine Weirich; Stollon, Natalie B.; Lucas, Matthew S.; Brumley, Lauren D.; Poole, Erika S.; Peyton, Tamara; Grant, Anne W.; Jan, Sophia; Trachtenberg, Symme; Zander, Miriam; Mamula, Petar; Bonafide, Christopher P.; Schwartz, Lisa A.

    2014-01-01

    Background For adolescents and young adults (AYA) with inflammatory bowel disease (IBD), the transition from pediatric to adult care is often challenging and associated with gaps in care. Our study objectives were to (1) identify outcomes for evaluating transition success and (2) elicit the major barriers and facilitators of successful transition. Methods We interviewed pediatric and adult IBD providers from across the United States with experience caring for AYAs with IBD until thematic saturation was reached after 12 interviews. We elicited the participants' backgrounds, examples of successful and unsuccessful transition of AYAs for whom they cared, and recommendations for improving transition using the Social-ecological Model of Adolescent and Young Adult Readiness to Transition framework. We coded interview transcripts using the constant comparative method and identified major themes. Results Participants reported evaluating transition success and failure using healthcare utilization outcomes (e.g. maintaining continuity with adult providers), health outcomes (e.g. stable symptoms), and quality of life outcomes (e.g. attending school). The patients' level of developmental maturity (i.e. ownership of care) was the most prominent determinant of transition outcomes. The style of parental involvement (i.e. helicopter parent vs. optimally-involved parent) also influenced outcomes as well as the degree of support by providers (e.g. care coordination). Conclusion IBD transition success is influenced by a complex interplay of patient developmental maturity, parenting style, and provider support. Multidisciplinary IBD care teams should aim to optimize these factors for each patient to increase the likelihood of a smooth transfer to adult care. PMID:25137417

  5. Invasion Success in a Marginal Habitat: An Experimental Test of Competitive Ability and Drought Tolerance in Chromolaena odorata

    PubMed Central

    te Beest, Mariska; Elschot, Kelly; Olff, Han; Etienne, Rampal S.

    2013-01-01

    Climatic niche models based on native-range climatic data accurately predict invasive-range distributions in the majority of species. However, these models often do not account for ecological and evolutionary processes, which limit the ability to predict future range expansion. This might be particularly problematic in the case of invaders that occupy environments that would be considered marginal relative to the climatic niche in the native range of the species. Here, we assess the potential for future range expansion in the shrub Chromolaena odorata that is currently invading mesic savannas (>650 mm MAP) in South Africa that are colder and drier than most habitats in its native range. In a greenhouse experiment we tested whether its current distribution in South Africa can be explained by increased competitive ability and/or differentiation in drought tolerance relative to the native population. We compared aboveground biomass, biomass allocation, water use efficiency and relative yields of native and invasive C. odorata and the resident grass Panicum maximum in wet and dry conditions. Surprisingly, we found little differentiation between ranges. Invasive C. odorata showed no increased competitive ability or superior drought tolerance compared to native C. odorata. Moreover we found that P. maximum was a better competitor than either native or invasive C. odorata. These results imply that C. odorata is unlikely to expand its future range towards more extreme, drier, habitats beyond the limits of its current climatic niche and that the species’ invasiveness most likely depends on superior light interception when temporarily released from competition by disturbance. Our study highlights the fact that species can successfully invade habitats that are at the extreme end of their ranges and thereby contributes towards a better understanding of range expansion during species invasions. PMID:23936301

  6. Invasion success in a marginal habitat: an experimental test of competitive ability and drought tolerance in Chromolaena odorata.

    PubMed

    te Beest, Mariska; Elschot, Kelly; Olff, Han; Etienne, Rampal S

    2013-01-01

    Climatic niche models based on native-range climatic data accurately predict invasive-range distributions in the majority of species. However, these models often do not account for ecological and evolutionary processes, which limit the ability to predict future range expansion. This might be particularly problematic in the case of invaders that occupy environments that would be considered marginal relative to the climatic niche in the native range of the species. Here, we assess the potential for future range expansion in the shrub Chromolaena odorata that is currently invading mesic savannas (>650 mm MAP) in South Africa that are colder and drier than most habitats in its native range. In a greenhouse experiment we tested whether its current distribution in South Africa can be explained by increased competitive ability and/or differentiation in drought tolerance relative to the native population. We compared aboveground biomass, biomass allocation, water use efficiency and relative yields of native and invasive C. odorata and the resident grass Panicum maximum in wet and dry conditions. Surprisingly, we found little differentiation between ranges. Invasive C. odorata showed no increased competitive ability or superior drought tolerance compared to native C. odorata. Moreover we found that P. maximum was a better competitor than either native or invasive C. odorata. These results imply that C. odorata is unlikely to expand its future range towards more extreme, drier, habitats beyond the limits of its current climatic niche and that the species' invasiveness most likely depends on superior light interception when temporarily released from competition by disturbance. Our study highlights the fact that species can successfully invade habitats that are at the extreme end of their ranges and thereby contributes towards a better understanding of range expansion during species invasions.

  7. Adaptive management in EBIPM: A key to success in invasive plant management

    Technology Transfer Automated Retrieval System (TEKTRAN)

    EBIPM is an important advancement in management of invasive plants. EBIPM puts land management decisions on a sound-footing based on ecological principles that cause plant community change. These principles, however, must be incorporated into the adaptive management cycle to truly make a change in h...

  8. Early detection monitoring of aquatic invasive species: Measuring performance success in a Lake Superior pilot network

    EPA Science Inventory

    The Great Lakes Water Quality Agreement, Annex 6 calls for a U.S.-Canada, basin-wide aquatic invasive species early detection network by 2015. The objective of our research is to explore survey design strategies that can improve detection efficiency, and to develop performance me...

  9. "Eh! I Felt I Was Sabotaged!": Facilitators' Understandings of Success in a Participatory HIV and IPV Prevention Intervention in Urban South Africa

    ERIC Educational Resources Information Center

    Gibbs, Andrew; Willan, Samantha; Jama-Shai, Nwabisa; Washington, Laura; Jewkes, Rachel

    2015-01-01

    Participatory approaches to behaviour change dominate HIV- and intimate partner violence prevention interventions. Research has identified multiple challenges in the delivery of these. In this article, we focus on how facilitators conceptualize successful facilitation and how these understandings may undermine dialogue and critical consciousness,…

  10. Genetic structure, admixture and invasion success in a Holarctic defoliator, the gypsy moth (Lymantria dispar, Lepidoptera: Erebidae).

    PubMed

    Wu, Yunke; Molongoski, John J; Winograd, Deborah F; Bogdanowicz, Steven M; Louyakis, Artemis S; Lance, David R; Mastro, Victor C; Harrison, Richard G

    2015-03-01

    Characterizing the current population structure of potentially invasive species provides a critical context for identifying source populations and for understanding why invasions are successful. Non-native populations inevitably lose genetic diversity during initial colonization events, but subsequent admixture among independently introduced lineages may increase both genetic variation and adaptive potential. Here we characterize the population structure of the gypsy moth (Lymantria dispar Linnaeus), one of the world's most destructive forest pests. Native to Eurasia and recently introduced to North America, the current distribution of gypsy moth includes forests throughout the temperate region of the northern hemisphere. Analyses of microsatellite loci and mitochondrial DNA sequences for 1738 individuals identified four genetic clusters within L. dispar. Three of these clusters correspond to the three named subspecies; North American populations represent a distinct fourth cluster, presumably a consequence of the population bottleneck and allele frequency change that accompanied introduction. We find no evidence that admixture has been an important catalyst of the successful invasion and range expansion in North America. However, we do find evidence of ongoing hybridization between subspecies and increased genetic variation in gypsy moth populations from Eastern Asia, populations that now pose a threat of further human-mediated introductions. Finally, we show that current patterns of variation can be explained in terms of climate and habitat changes during the Pleistocene, a time when temperate forests expanded and contracted. Deeply diverged matrilines in Europe imply that gypsy moths have been there for a long time and are not recent arrivals from Asia.

  11. Case Studies Due to Invasive Plants on the Vegetation Retardation Succession in Landslide Areas of Shimen reservoir

    NASA Astrophysics Data System (ADS)

    Huang, Wen-Cheng; Lin, Shin-Hwei

    2014-05-01

    The steep terrain and the fragile geology in Taiwan have caused large landslides in the reservoir watershed in the season with typhoons and heavy rain. Management, restoration strategies, and vegetation succession mechanism of landslide areas are distinct due to different attributes and locations of landslide areas. Aiming at 50 landslide areas in Shihmen reservoir watershed from 2004 to 2012, because of the Typhoon Aere occurred in 2004, this study clusters with the primary vegetation data and ortho image, and discusses the primary vegetation type in landslide areas. The successive management engineering in the watershed and the case data in Sule and Shaluntzu are analyzed the vegetation development and plant competition to evaluate the plant succession mechanism and the vegetation restoration results for the reference of successive design of vegetation engineering in landslide areas. The result shows that Shaluntzu area used invasive plants Rhodesgrass and Rhodesian kudzu when slope land vegetation restoration and secondary planting seedlings. Rhodesian kudzu has property of binding plant and causes for vegetation death. Currently, cutting down Rhodesian kudzu to reduce its interference is the most effective prevention and management method. Carefully choose the pre-grass species for vegetation in the have to carry out artificial vegetation restoration area, and continue to monitor the status currently. It would increase biodiversity for slope land due to select the indicator species of vegetation restoration and know successional trends of invasive plant species.

  12. Success in Competition for Space in Two Invasive Coral Species in the western Atlantic - Tubastraea micranthus and T. coccinea.

    PubMed

    Sammarco, Paul W; Porter, Scott A; Genazzio, Melissa; Sinclair, James

    2015-01-01

    Invasion success by an alien species is dependent upon rate of reproduction, growth, mortality, physical characteristics of the environment, and successful competition for resources with native species. For sessile, epibenthic marine species, one critical resource is space. We examined competitive success in two invasive Indo-Pacific corals involved in competition for space in the northern Gulf of Mexico-Tubastraea coccinea and T. micranthus-on up to 13 offshore oil/gas platforms south of the Mississippi River. Still-capture photos of thousands of overgrowth interactions between the target corals and other sessile epibenthic fauna were analyzed from ROV videos collected at 8-183 m depth. T. micranthus was observed overgrowing >90% of all sessile epibenthic species which it encountered. Frequencies of competitive success varied significantly between platforms. T. coccinea was competitively superior to all competitors pooled, at the 60% level. There was little variability between T. coccinea populations. T. coccinea encountered the following species most frequently-the encrusting sponges Xestospongia sp. (with the commensal Parazoanthus catenularis), X. carbonaria, Dictyonella funicularis, Mycale carmigropila, Phorbas amaranthus, and Haliclona vansoesti-and was found to be, on average, competitively superior to them. Both T. micranthus and T. coccinea appear to be good competitors for space against these species in the northern Gulf of Mexico. Competitive success in T. micranthus was highest in the NE part of the study area, and lowest in the SW area near the Mississippi River plume. T. coccinea's competitive success peaked in the SW study area. This suggests that variation in competitive success both within and between populations of these species may be due to differences in local environmental factors. PMID:26684321

  13. Success in Competition for Space in Two Invasive Coral Species in the western Atlantic – Tubastraea micranthus and T. coccinea

    PubMed Central

    Sammarco, Paul W.; Porter, Scott A.; Genazzio, Melissa; Sinclair, James

    2015-01-01

    Invasion success by an alien species is dependent upon rate of reproduction, growth, mortality, physical characteristics of the environment, and successful competition for resources with native species. For sessile, epibenthic marine species, one critical resource is space. We examined competitive success in two invasive Indo-Pacific corals involved in competition for space in the northern Gulf of Mexico—Tubastraea coccinea and T. micranthus—on up to 13 offshore oil/gas platforms south of the Mississippi River. Still-capture photos of thousands of overgrowth interactions between the target corals and other sessile epibenthic fauna were analyzed from ROV videos collected at 8–183 m depth. T. micranthus was observed overgrowing >90% of all sessile epibenthic species which it encountered. Frequencies of competitive success varied significantly between platforms. T. coccinea was competitively superior to all competitors pooled, at the 60% level. There was little variability between T. coccinea populations. T. coccinea encountered the following species most frequently—the encrusting sponges Xestospongia sp. (with the commensal Parazoanthus catenularis), X. carbonaria, Dictyonella funicularis, Mycale carmigropila, Phorbas amaranthus, and Haliclona vansoesti—and was found to be, on average, competitively superior to them. Both T. micranthus and T. coccinea appear to be good competitors for space against these species in the northern Gulf of Mexico. Competitive success in T. micranthus was highest in the NE part of the study area, and lowest in the SW area near the Mississippi River plume. T. coccinea’s competitive success peaked in the SW study area. This suggests that variation in competitive success both within and between populations of these species may be due to differences in local environmental factors. PMID:26684321

  14. The PDZ protein TIP-1 facilitates cell migration and pulmonary metastasis of human invasive breast cancer cells in athymic mice

    SciTech Connect

    Han, Miaojun; Wang, Hailun; Zhang, Hua-Tang; Han, Zhaozhong

    2012-05-25

    Highlights: Black-Right-Pointing-Pointer This study has revealed novel oncogenic functions of TIP-1 in human invasive breast cancer. Black-Right-Pointing-Pointer Elevated TIP-1 expression levels in human breast cancers correlate to the disease prognosis. Black-Right-Pointing-Pointer TIP-1 knockdown suppressed the cell migration and pulmonary metastasis of human breast cancer cells. Black-Right-Pointing-Pointer TIP-1 knockdown suppressed the expression and functionality of motility-related genes. -- Abstract: Tax-interacting protein 1 (TIP-1, also known as Tax1bp3) inhibited proliferation of colon cancer cells through antagonizing the transcriptional activity of beta-catenin. However, in this study, elevated TIP-1 expression levels were detected in human invasive breast cancers. Studies with two human invasive breast cancer cell lines indicated that RNAi-mediated TIP-1 knockdown suppressed the cell adhesion, proliferation, migration and invasion in vitro, and inhibited tumor growth in mammary fat pads and pulmonary metastasis in athymic mice. Biochemical studies showed that TIP-1 knockdown had moderate and differential effects on the beta-catenin-regulated gene expression, but remarkably down regulated the genes for cell adhesion and motility in breast cancer cells. The decreased expression of integrins and paxillin was accompanied with reduced cell adhesion and focal adhesion formation on fibronectin-coated surface. In conclusion, this study revealed a novel oncogenic function of TIP-1 suggesting that TIP-1 holds potential as a prognostic biomarker and a therapeutic target in the treatment of human invasive breast cancers.

  15. Inadvertent subclavian artery cannulation with a central venous catheter; successful retrieval using a minimally invasive technique.

    PubMed

    Redmond, C E; O'Donohoe, R; Breslin, D; Brophy, D P

    2014-10-01

    A 48-year-old lady was referred to our department as an emergency following an unsuccessful attempt at central venous catheter insertion, resulting in cannulation of the subclavian artery. She underwent angiography with removal of the catheter and closure of the arteriotomy using an Angio-Seal device. While the optimal management of this scenario has yet to be defined, the use of this minimally invasive technique warrants consideration. PMID:25507120

  16. Inadvertent subclavian artery cannulation with a central venous catheter; successful retrieval using a minimally invasive technique.

    PubMed

    Redmond, C E; O'Donohoe, R; Breslin, D; Brophy, D P

    2014-10-01

    A 48-year-old lady was referred to our department as an emergency following an unsuccessful attempt at central venous catheter insertion, resulting in cannulation of the subclavian artery. She underwent angiography with removal of the catheter and closure of the arteriotomy using an Angio-Seal device. While the optimal management of this scenario has yet to be defined, the use of this minimally invasive technique warrants consideration. PMID:25417392

  17. Successful treatment of an invasive fungal infection caused by Talaromyces sp. with voriconazole

    PubMed Central

    Sili, Uluhan; Bilgin, Huseyin; Masania, Rikesh; Eryuksel, Emel; Cimsit, Nuri Cagatay; Ayranci, Gulcicek; Richardson, Malcolm; Korten, Volkan

    2015-01-01

    Invasive fungal infections (IFI) are on the rise due to increasing numbers of immunosuppressed and critically ill patients. A malignant-looking pulmonary nodule in an immunosuppressed patient may indeed be caused by a fungal organism. We report a patient, who was eventually diagnosed with an IFI caused by an agent of hyalohyphomycosis, Talaromyces sp. determined via molecular methods and succesfully treated with voriconazole. PMID:25830087

  18. Successful treatment of an invasive fungal infection caused by Talaromyces sp. with voriconazole.

    PubMed

    Sili, Uluhan; Bilgin, Huseyin; Masania, Rikesh; Eryuksel, Emel; Cimsit, Nuri Cagatay; Ayranci, Gulcicek; Richardson, Malcolm; Korten, Volkan

    2015-06-01

    Invasive fungal infections (IFI) are on the rise due to increasing numbers of immunosuppressed and critically ill patients. A malignant-looking pulmonary nodule in an immunosuppressed patient may indeed be caused by a fungal organism. We report a patient, who was eventually diagnosed with an IFI caused by an agent of hyalohyphomycosis, Talaromyces sp. determined via molecular methods and succesfully treated with voriconazole. PMID:25830087

  19. 'Eh! I felt I was sabotaged!': facilitators' understandings of success in a participatory HIV and IPV prevention intervention in urban South Africa.

    PubMed

    Gibbs, Andrew; Willan, Samantha; Jama-Shai, Nwabisa; Washington, Laura; Jewkes, Rachel

    2015-12-01

    Participatory approaches to behaviour change dominate HIV- and intimate partner violence prevention interventions. Research has identified multiple challenges in the delivery of these. In this article, we focus on how facilitators conceptualize successful facilitation and how these understandings may undermine dialogue and critical consciousness, through a case study of facilitators engaged in the delivery of Stepping Stones and Creating Futures and ten focus-group discussions held with facilitators. All facilitators continually emphasized the importance of discussion and active engagement by participants. However, other understandings of successful facilitation also emerged, including group management--particularly securing high levels of attendance; ensuring answers provided by participants were 'right'; being active facilitators; and achieving behaviour change. These in various ways potentially undermined dialogue and the emergence of critical thinking. We locate these different understandings of success as located in the wider context of conceptualizations of autonomy and structure; historical experiences of work and education; and the ongoing tension between the requirements of rigorous research and those of participatory interventions. We suggest a new approach to training and support for facilitators is required if participatory interventions are to be delivered at scale, as they must be. PMID:26590246

  20. Metatranscriptomics and pyrosequencing facilitate discovery of potential viral natural enemies of the invasive Caribbean crazy ant, Nylanderia pubens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background: Nylanderia pubens (Forel) is an invasive ant species that in recent years has developed into a serious nuisance problem in the Caribbean and United States. A rapidly expanding range, explosive localized population growth, and control difficulties have elevated this ant to pest status. ...

  1. Over-invasion by functionally equivalent invasive species.

    PubMed

    Russell, James C; Sataruddin, Nurul S; Heard, Allison D

    2014-08-01

    Multiple invasive species have now established at most locations around the world, and the rate of new species invasions and records of new invasive species continue to grow. Multiple invasive species interact in complex and unpredictable ways, altering their invasion success and impacts on biodiversity. Incumbent invasive species can be replaced by functionally similar invading species through competitive processes; however the generalized circumstances leading to such competitive displacement have not been well investigated. The likelihood of competitive displacement is a function of the incumbent advantage of the resident invasive species and the propagule pressure of the colonizing invasive species. We modeled interactions between populations of two functionally similar invasive species and indicated the circumstances under which dominance can be through propagule pressure and incumbent advantage. Under certain circumstances, a normally subordinate species can be incumbent and reject a colonizing dominant species, or successfully colonize in competition with a dominant species during simultaneous invasion. Our theoretical results are supported by empirical studies of the invasion of islands by three invasive Rattus species. Competitive displacement is prominent in invasive rats and explains the replacement of R. exulans on islands subsequently invaded by European populations of R. rattus and R. norvegicus. These competition outcomes between invasive species can be found in a broad range of taxa and biomes, and are likely to become more common. Conservation management must consider that removing an incumbent invasive species may facilitate invasion by another invasive species. Under very restricted circumstances of dominant competitive ability but lesser impact, competitive displacement may provide a novel method of biological control.

  2. From richer to poorer: successful invasion by freshwater fishes depends on species richness of donor and recipient basins.

    PubMed

    Fitzgerald, Daniel B; Tobler, Michael; Winemiller, Kirk O

    2016-07-01

    Evidence for the theory of biotic resistance is equivocal, with experiments often finding a negative relationship between invasion success and native species richness, and large-scale comparative studies finding a positive relationship. Biotic resistance derives from local species interactions, yet global and regional studies often analyze data at coarse spatial grains. In addition, differences in competitive environments across regions may confound tests of biotic resistance based solely on native species richness of the invaded community. Using global and regional data sets for fishes in river and stream reaches, we ask two questions: (1) does a negative relationship exist between native and non-native species richness and (2) do non-native species originate from higher diversity systems. A negative relationship between native and non-native species richness in local assemblages was found at the global scale, while regional patterns revealed the opposite trend. At both spatial scales, however, nearly all non-native species originated from river basins with higher native species richness than the basin of the invaded community. Together, these findings imply that coevolved ecological interactions in species-rich systems inhibit establishment of generalist non-native species from less diverse communities. Consideration of both the ecological and evolutionary aspects of community assembly is critical to understanding invasion patterns. Distinct evolutionary histories in different regions strongly influence invasion of intact communities that are relatively unimpacted by human actions, and may explain the conflicting relationship between native and non-native species richness found at different spatial scales.

  3. Landscape Factors Facilitating the Invasive Dynamics and Distribution of the Brown Marmorated Stink Bug, Halyomorpha halys (Hemiptera: Pentatomidae), after Arrival in the United States

    PubMed Central

    Wallner, Adam M.; Hamilton, George C.; Nielsen, Anne L.; Hahn, Noel; Green, Edwin J.; Rodriguez-Saona, Cesar R.

    2014-01-01

    The brown marmorated stink bug, Halyomorpha halys, a native of Asia, has become a serious invasive pest in the USA. H. halys was first detected in the USA in the mid 1990s, dispersing to over 41 other states. Since 1998, H. halys has spread throughout New Jersey, becoming an important pest of agriculture, and a major nuisance in urban developments. In this study, we used spatial analysis, geostatistics, and Bayesian linear regression to investigate the invasion dynamics and colonization processes of this pest in New Jersey. We present the results of monitoring H. halys from 51 to 71 black light traps that were placed on farms throughout New Jersey from 2004 to 2011 and examined relationships between total yearly densities of H. halys and square hectares of 48 landscape/land use variables derived from urban, wetland, forest, and agriculture metadata, as well as distances to nearest highways. From these analyses we propose the following hypotheses: (1) H. halys density is strongly associated with urban developments and railroads during its initial establishment and dispersal from 2004 to 2006; (2) H. halys overwintering in multiple habitats and feeding on a variety of plants may have reduced the Allee effect, thus facilitating movement into the southernmost regions of the state by railroads from 2005 to 2008; (3) density of H. halys contracted in 2009 possibly from invading wetlands or sampling artifact; (4) subsequent invasion of H. halys from the northwest to the south in 2010 may conform to a stratified-dispersal model marked by rapid long-distance movement, from railroads and wetland rights-of-way; and (5) high densities of H. halys may be associated with agriculture in southern New Jersey in 2011. These landscape features associated with the invasion of H. halys in New Jersey may predict its potential rate of invasion across the USA and worldwide. PMID:24787576

  4. Aquatic pollution may favor the success of the invasive species A. franciscana.

    PubMed

    Varó, I; Redón, S; Garcia-Roger, E M; Amat, F; Guinot, D; Serrano, R; Navarro, J C

    2015-04-01

    The genus Artemia consists of several bisexual and parthenogenetic sibling species. One of them, A. franciscana, originally restricted to the New World, becomes invasive when introduced into ecosystems out of its natural range of distribution. Invasiveness is anthropically favored by the use of cryptobiotic eggs in the aquaculture and pet trade. The mechanisms of out-competition of the autochthonous Artemia by the invader are still poorly understood. Ecological fitness may play a pivotal role, but other underlying biotic and abiotic factors may contribute. Since the presence of toxicants in hypersaline aquatic ecosystems has been documented, our aim here is to study the potential role of an organophosphate pesticide, chlorpyrifos, in a congeneric mechanism of competition between the bisexual A. franciscana (AF), and one of the Old World parthenogenetic siblings, A. parthenogenetica (PD). For this purpose we carried out life table experiments with both species, under different concentrations of the toxicant (0.1, 1 and 5μg/l), and analyzed the cholinesterase inhibition at different developmental stages. The results evidence that both, AF and PD, showed an elevated tolerance to high ranges of chlorpyrifos, but AF survived better and its fecundity was less affected by the exposure to the pesticide than that of PD. The higher fecundity of AF is a selective advantage in colonization processes leading to its establishment as NIS. Besides, under the potential selective pressure of abiotic factors, such as the presence of toxicants, its higher resistance in terms of survival and biological fitness also indicates out-competitive advantages.

  5. Indirect effects of parasites in invasions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Introduced species disrupt native communities and biodiversity worldwide. Parasitic infections (and at times, their absence) are thought to be a key component in the success and impact of biological invasions by plants and animals. They can facilitate or limit invasions, and positively or negatively...

  6. Climate change likely to facilitate the invasion of the non-native hydroid, Cordylophora caspia, in the San Francisco Estuary.

    PubMed

    Meek, Mariah H; Wintzer, Alpa P; Wetzel, William C; May, Bernie

    2012-01-01

    Climate change and invasive species can both have negative impacts on native species diversity. Additionally, climate change has the potential to favor invasive species over natives, dealing a double blow to native biodiversity. It is, therefore, vital to determine how changing climate conditions are directly linked to demographic rates and population growth of non-native species so we can quantitatively evaluate how invasive populations may be affected by changing conditions and, in turn, impact native species. Cordylophora caspia, a hydrozoan from the Ponto-Caspian region, has become established in the brackish water habitats of the San Francisco Estuary (SFE). We conducted laboratory experiments to study how temperature and salinity affect C. caspia population growth rates, in order to predict possible responses to climate change. C. Caspia population growth increased nonlinearly with temperature and leveled off at a maximum growth rate near the annual maximum temperature predicted under a conservative climate change scenario. Increasing salinity, however, did not influence growth rates. Our results indicate that C. caspia populations in the SFE will benefit from predicted regional warming trends and be little affected by changes in salinity. The population of C. caspia in the SFE has the potential to thrive under future climate conditions and may subsequently increase its negative impact on the food web.

  7. Climate Change Likely to Facilitate the Invasion of the Non-Native Hydroid, Cordylophora caspia, in the San Francisco Estuary

    PubMed Central

    Meek, Mariah H.; Wintzer, Alpa P.; Wetzel, William C.; May, Bernie

    2012-01-01

    Climate change and invasive species can both have negative impacts on native species diversity. Additionally, climate change has the potential to favor invasive species over natives, dealing a double blow to native biodiversity. It is, therefore, vital to determine how changing climate conditions are directly linked to demographic rates and population growth of non-native species so we can quantitatively evaluate how invasive populations may be affected by changing conditions and, in turn, impact native species. Cordylophora caspia, a hydrozoan from the Ponto-Caspian region, has become established in the brackish water habitats of the San Francisco Estuary (SFE). We conducted laboratory experiments to study how temperature and salinity affect C. caspia population growth rates, in order to predict possible responses to climate change. C. Caspia population growth increased nonlinearly with temperature and leveled off at a maximum growth rate near the annual maximum temperature predicted under a conservative climate change scenario. Increasing salinity, however, did not influence growth rates. Our results indicate that C. caspia populations in the SFE will benefit from predicted regional warming trends and be little affected by changes in salinity. The population of C. caspia in the SFE has the potential to thrive under future climate conditions and may subsequently increase its negative impact on the food web. PMID:23071559

  8. Genetic structure, admixture and invasion success in a Holarctic defoliator, the gypsy moth (Lymantria dispar, Lepidoptera: Erebidae).

    PubMed

    Wu, Yunke; Molongoski, John J; Winograd, Deborah F; Bogdanowicz, Steven M; Louyakis, Artemis S; Lance, David R; Mastro, Victor C; Harrison, Richard G

    2015-03-01

    Characterizing the current population structure of potentially invasive species provides a critical context for identifying source populations and for understanding why invasions are successful. Non-native populations inevitably lose genetic diversity during initial colonization events, but subsequent admixture among independently introduced lineages may increase both genetic variation and adaptive potential. Here we characterize the population structure of the gypsy moth (Lymantria dispar Linnaeus), one of the world's most destructive forest pests. Native to Eurasia and recently introduced to North America, the current distribution of gypsy moth includes forests throughout the temperate region of the northern hemisphere. Analyses of microsatellite loci and mitochondrial DNA sequences for 1738 individuals identified four genetic clusters within L. dispar. Three of these clusters correspond to the three named subspecies; North American populations represent a distinct fourth cluster, presumably a consequence of the population bottleneck and allele frequency change that accompanied introduction. We find no evidence that admixture has been an important catalyst of the successful invasion and range expansion in North America. However, we do find evidence of ongoing hybridization between subspecies and increased genetic variation in gypsy moth populations from Eastern Asia, populations that now pose a threat of further human-mediated introductions. Finally, we show that current patterns of variation can be explained in terms of climate and habitat changes during the Pleistocene, a time when temperate forests expanded and contracted. Deeply diverged matrilines in Europe imply that gypsy moths have been there for a long time and are not recent arrivals from Asia. PMID:25655667

  9. Leaf Photosynthesis and Plant Competitive Success in a Mixed-grass Prairie: With Reference to Exotic Grasses Invasion

    DOE PAGESBeta

    Dong, Dr. Xuejun; Patton, J.; Gu, Lianhong; Wang, J.; Patton, B.

    2014-11-26

    The widespread invasion of exotic cool-season grasses in mixed-grass rangeland is diminishing the hope of bringing back the natural native plant communities. However, ecophysiological mechanisms explaining the relative competitiveness of these invasive grasses over the native species generally are lacking. In this study, we used experimental data collected in south-central North Dakota, USA to address this issue. Photosynthetic potential was obtained from the net assimilation (A) vs. internal CO2 (Ci) response curves from plants grown in a greenhouse. Plant success was defined as the average frequency measured over 25 years (1988 to 2012) on overflow range sites across five levelsmore » of grazing intensity. In addition, estimated leaf area index of individual species under field conditions was used to indicate plant success. The correlation between photosynthetic potential based on A/Ci curves and plant frequency was negative. The correlation between leaf photosynthesis and plant success (defined as leaf area within a unit land area) was also negative, although statistically weak. These results suggest that the two cool-season grasses, Poa pratensis and Bromus inermis, do not rely on superior leaf-level photosynthesis for competitive success. Instead, some other traits, such as early and late-season growth, may be more important for them to gain dominance in the mixed-grass prairie. We propose that the negative photosynthesis-frequency relation as observed in this study results from a strong competition for limited soil nutrients in the mixed-grass prairie. In conclusion, it has implications for the stability and productivity of the grassland under various human disruptions influencing the soil nutrient status.« less

  10. Leaf Photosynthesis and Plant Competitive Success in a Mixed-grass Prairie: With Reference to Exotic Grasses Invasion

    SciTech Connect

    Dong, Dr. Xuejun; Patton, J.; Gu, Lianhong; Wang, J.; Patton, B.

    2014-11-26

    The widespread invasion of exotic cool-season grasses in mixed-grass rangeland is diminishing the hope of bringing back the natural native plant communities. However, ecophysiological mechanisms explaining the relative competitiveness of these invasive grasses over the native species generally are lacking. In this study, we used experimental data collected in south-central North Dakota, USA to address this issue. Photosynthetic potential was obtained from the net assimilation (A) vs. internal CO2 (Ci) response curves from plants grown in a greenhouse. Plant success was defined as the average frequency measured over 25 years (1988 to 2012) on overflow range sites across five levels of grazing intensity. In addition, estimated leaf area index of individual species under field conditions was used to indicate plant success. The correlation between photosynthetic potential based on A/Ci curves and plant frequency was negative. The correlation between leaf photosynthesis and plant success (defined as leaf area within a unit land area) was also negative, although statistically weak. These results suggest that the two cool-season grasses, Poa pratensis and Bromus inermis, do not rely on superior leaf-level photosynthesis for competitive success. Instead, some other traits, such as early and late-season growth, may be more important for them to gain dominance in the mixed-grass prairie. We propose that the negative photosynthesis-frequency relation as observed in this study results from a strong competition for limited soil nutrients in the mixed-grass prairie. In conclusion, it has implications for the stability and productivity of the grassland under various human disruptions influencing the soil nutrient status.

  11. Salt tolerance traits increase the invasive success of Acacia longifolia in Portuguese coastal dunes.

    PubMed

    Morais, Maria Cristina; Panuccio, Maria Rosaria; Muscolo, Adele; Freitas, Helena

    2012-06-01

    Salt tolerance of two co-occurring legumes in coastal areas of Portugal, a native species--Ulex europaeus, and an invasive species--Acacia longifolia, was evaluated in relation to plant growth, ion content and antioxidant enzyme activities. Plants were submitted to four concentrations of NaCl (0, 50, 100 and 200 mM) for three months, under controlled conditions. The results showed that NaCl affects the growth of both species in different ways. Salt stress significantly reduced the plant height and the dry weight in Acacia longifolia whereas in U. europaeus the effect was not significant. Under salt stress, the root:shoot ratio (W(R):W(S)) and root mass ratio (W(R):W(RS)) increased as a result of increasing salinity in A. longifolia but the same was not observed in U. europaeus. In addition, salt stress caused a significant accumulation of Na+, especially in U. europaeus, and a decrease in K+ content and K+/Na+ ratio. The activities of antioxidant enzymes were higher in A. longifolia compared to U. europaeus. In A. longifolia, catalase (CAT, EC 1.11.1.6) and glutathione reductase (GR, EC 1.6.4.2.) activities increased significantly, while ascorbate peroxidase (APX, EC 1.11.1.11) and peroxidase (POX, EC 1.11.1.7) activities remained unchanged in comparison with the control. In U. europaeus, NaCl concentration significantly reduced APX activity but did not significantly affect CAT, GR and POX activities. Our results suggest that the invasive species copes better with salinity stress in part due to a higher rates of CAT and GR activities and a higher K+/Na+ ratio, which may represent an additional advantage when competing with native species in co-occurring salty habitats.

  12. Life-threatening upper gastrointestinal bleeding due to gastric Dieulafoy's lesion: Successful minimally-invasive management.

    PubMed

    Bondade, Nikhil; Bhandari, Suryaprakash; Rao, Prashant; Shah, Rahul; Bothara, Vishal; Maydeo, Amit

    2016-01-01

    Dieulafoy's lesion (DL) is a relatively rare, but potentially life-threatening condition. It accounts for 1-2% of acute gastrointestinal bleedings. Its serious nature makes it necessary for early diagnosis and treatment. This is a case report of a patient who presented with life-threatening haematemesis due to gastric Dieulafoy's that was successfully treated laparoscopically after failed endotherapy. PMID:27251825

  13. Life-threatening upper gastrointestinal bleeding due to gastric Dieulafoy's lesion: Successful minimally-invasive management

    PubMed Central

    Bondade, Nikhil; Bhandari, Suryaprakash; Rao, Prashant; Shah, Rahul; Bothara, Vishal; Maydeo, Amit

    2016-01-01

    Dieulafoy's lesion (DL) is a relatively rare, but potentially life-threatening condition. It accounts for 1-2% of acute gastrointestinal bleedings. Its serious nature makes it necessary for early diagnosis and treatment. This is a case report of a patient who presented with life-threatening haematemesis due to gastric Dieulafoy's that was successfully treated laparoscopically after failed endotherapy. PMID:27251825

  14. Enteroscopic Tattooing for Better Intraoperative Localization of a Bleeding Jejunal GIST Facilitates Minimally Invasive Laparoscopically-assisted Surgery.

    PubMed

    Iacob, Razvan; Dimitriu, Anca; Stanciulea, Oana; Herlea, Vlad; Popescu, Irinel; Gheorghe, Cristian

    2016-03-01

    We present the case of a 63-year-old man that was admitted for melena and severe anemia. Upper GI endoscopy and colonoscopy failed to identify the lesion responsible for bleeding, and enteroCT scan was also non-contributive to the diagnosis. Capsule endoscopy indicated possible jejunal bleeding but could not indicate the source of bleeding, recommending anterograde enteroscopy. Single balloon enteroscopy identified a 2 cm submucosal tumour in the distal part of the jejunum, with a macroscopic appearance suggesting a gastrointestinal stromal tumour (GIST). The tumor location was marked using SPOT tattoo and subsequently easily identified by the surgeon and resected via minimally invasive laparoscopic-assisted approach. Histological and immunohistochemical analysis indicated a low risk GIST. The unusual small size of the GIST as a modality of presentation, with digestive bleeding and anemia and the ability to use VCE/enteroscopy to identify and mark the lesion prior to minimally invasive surgery, represent the particularities of the presented case. PMID:27014761

  15. [A case of advanced esophageal cancer with direct bronchial invasion successfully treated by multidisciplinary therapy].

    PubMed

    Haba, Yusuke; Okamoto, Koichi; Watanabe, Toshifumi; Tsukada, Tomoya; Kinoshita, Jun; Makino, Isamu; Nakamura, Keishi; Oyama, Katsunobu; Ninomiya, Itasu; Fushida, Sachio; Fujimura, Takashi; Ohta, Tetsuo

    2014-11-01

    A 66-year-old man with advanced esophageal cancer (staging Mt, 6.0 cm, cT3N0M0, cStage II) was administered neoadjuvant chemotherapy (NAC: 5-fluorouracil and cisplatin). As the tumor continued to grow after one course of NAC, video-assisted thoracoscopic surgery(VATS) was used to perform an esophagectomy along with 3-field lymph node dissection and retrosternal route reconstruction using a gastric tube. The second course of NAC was not administered. Intraoperative findings showed the direct invasion of the primary esophageal cancer into the membranous portion of the left bronchus. The maximum possible tumor tissue was resected and removed. The tumor tissue was exposed extensively to the surface of the esophageal adventitia and a residual tumor at the surface of the left bronchus was suspected. It was diagnosed as CT-pT4 (left bronchus), N0, M0, CT-pStage III. Subsequently, we administered chemoradiotherapy consisting of weekly low-dose docetaxel with radiation for the residual tumor (60 Gy/30 Fr). The patient is still alive 40 months after surgery without any signs of recurrence.

  16. The secret to successful deep-sea invasion: does low temperature hold the key?

    PubMed

    Smith, Kathryn E; Thatje, Sven

    2012-01-01

    There is a general consensus that today's deep-sea biodiversity has largely resulted from recurrent invasions and speciations occurring through homogenous waters during periods of the Phanerozoic eon. Migrations likely continue today, primarily via isothermal water columns, such as those typical of Polar Regions, but the necessary ecological and physiological adaptations behind them are poorly understood. In an evolutionary context, understanding the adaptations, which allow for colonisation to high-pressure environments, may enable us to predict future events. In this investigation, we examine pressure tolerance during development, in the shallow-water neogastropod Buccinum undatum using thermally acclimated egg masses from temperate and sub-polar regions across the species range. Fossil records indicate neogastropods to have a deep-water origin, suggesting shallow-water species may be likely candidates for re-emergence into the deep sea. Our results show population level differences in physiological thresholds, which indicate low temperature acclimation to increase pressure tolerance. These findings imply this species is capable of deep-sea penetration through isothermal water columns prevailing at high latitudes. This study gives new insight into the fundamentals behind past and future colonisation events. Such knowledge is instrumental to understand better how changes in climate envelopes affect the distribution and radiation of species along latitudinal as well as bathymetric temperature gradients.

  17. The Secret to Successful Deep-Sea Invasion: Does Low Temperature Hold the Key?

    PubMed Central

    Smith, Kathryn E.; Thatje, Sven

    2012-01-01

    There is a general consensus that today’s deep-sea biodiversity has largely resulted from recurrent invasions and speciations occurring through homogenous waters during periods of the Phanerozoic eon. Migrations likely continue today, primarily via isothermal water columns, such as those typical of Polar Regions, but the necessary ecological and physiological adaptations behind them are poorly understood. In an evolutionary context, understanding the adaptations, which allow for colonisation to high-pressure environments, may enable us to predict future events. In this investigation, we examine pressure tolerance during development, in the shallow-water neogastropod Buccinum undatum using thermally acclimated egg masses from temperate and sub-polar regions across the species range. Fossil records indicate neogastropods to have a deep-water origin, suggesting shallow-water species may be likely candidates for re-emergence into the deep sea. Our results show population level differences in physiological thresholds, which indicate low temperature acclimation to increase pressure tolerance. These findings imply this species is capable of deep-sea penetration through isothermal water columns prevailing at high latitudes. This study gives new insight into the fundamentals behind past and future colonisation events. Such knowledge is instrumental to understand better how changes in climate envelopes affect the distribution and radiation of species along latitudinal as well as bathymetric temperature gradients. PMID:23227254

  18. [A case of advanced esophageal cancer with direct bronchial invasion successfully treated by multidisciplinary therapy].

    PubMed

    Haba, Yusuke; Okamoto, Koichi; Watanabe, Toshifumi; Tsukada, Tomoya; Kinoshita, Jun; Makino, Isamu; Nakamura, Keishi; Oyama, Katsunobu; Ninomiya, Itasu; Fushida, Sachio; Fujimura, Takashi; Ohta, Tetsuo

    2014-11-01

    A 66-year-old man with advanced esophageal cancer (staging Mt, 6.0 cm, cT3N0M0, cStage II) was administered neoadjuvant chemotherapy (NAC: 5-fluorouracil and cisplatin). As the tumor continued to grow after one course of NAC, video-assisted thoracoscopic surgery(VATS) was used to perform an esophagectomy along with 3-field lymph node dissection and retrosternal route reconstruction using a gastric tube. The second course of NAC was not administered. Intraoperative findings showed the direct invasion of the primary esophageal cancer into the membranous portion of the left bronchus. The maximum possible tumor tissue was resected and removed. The tumor tissue was exposed extensively to the surface of the esophageal adventitia and a residual tumor at the surface of the left bronchus was suspected. It was diagnosed as CT-pT4 (left bronchus), N0, M0, CT-pStage III. Subsequently, we administered chemoradiotherapy consisting of weekly low-dose docetaxel with radiation for the residual tumor (60 Gy/30 Fr). The patient is still alive 40 months after surgery without any signs of recurrence. PMID:25731408

  19. The role of the invasive polychaete Ficopomatus enigmaticus (Fauvel, 1923) (Serpulidae) as facilitator of parasite transmission in Mar Chiquita coastal lagoon (Buenos Aires, Argentina).

    PubMed

    Etchegoin, J A; Merlo, M J; Parietti, M

    2012-09-01

    In Mar Chiquita coastal lagoon (Argentina), the reefs of the invasive polychaete Ficopomatus enigmaticus (Serpulidae) serve as concentration areas for invertebrates and vertebrates and as potential foci of parasite transmission (mainly digeneans). To analyse the role of F. enigmaticus as facilitator of parasite transmission, and to evaluate the influence of the habitats selected by 2 species of cochliopid snails (Heleobia conexa and Heleobia australis), on the richness and on the prevalence of the digenean assemblages that parasitize them, 1945 snails were collected from 2 sampling sites. The comparisons between larval digenean communities parasitizing both snail hosts revealed significant differences related to the overall prevalence and the prevalence contributed by birds in the snails collected from reefs. These results support the idea that the reefs may increase the number of links between intermediate and definitive hosts of digeneans, facilitating parasite transmission only when the aggregates of F. enigmaticus become the unique habitat of the snail host. This first report of an exotic species acting as facilitator of parasite transmission in an estuarine area highlights the importance of analysing the effects of the assimilation process of exotic species by recently colonized environments (including the possible effects on parasite transmission).

  20. Winning the invasion roulette: escapes from fish farms increase admixture and facilitate establishment of non-native rainbow trout

    PubMed Central

    Consuegra, Sofia; Phillips, Nia; Gajardo, Gonzalo; de Leaniz, Carlos Garcia

    2011-01-01

    Aquaculture is a major source of invasive aquatic species, despite the fact that cultured organisms often have low genetic diversity and tend to be maladapted to survive in the wild. Yet, to what extent aquaculture escapees become established by means of high propagule pressure and multiple origins is not clear. We analysed the genetic diversity of 15 established populations and four farmed stocks of non-native rainbow trout in Chile, a species first introduced for recreational fishing around 1900, but which has in recent decades escaped in large numbers from fish farms and become widespread. Aquaculture propagule pressure was a good predictor of the incidence of farm escapees, which represented 16% of all free-ranging rainbow trout and were present in 80% of the study rivers. Hybrids between farm escapes and established trout were present in all rivers at frequencies ranging between 7 and 69%, and population admixture was positively correlated with genetic diversity. We suggest that non-native salmonids introduced into the Southern Hemisphere could benefit from admixture because local adaptations may not have yet developed, and there may be initially little fitness loss resulting from outbreeding depression. PMID:25568013

  1. Winning the invasion roulette: escapes from fish farms increase admixture and facilitate establishment of non-native rainbow trout.

    PubMed

    Consuegra, Sofia; Phillips, Nia; Gajardo, Gonzalo; de Leaniz, Carlos Garcia

    2011-09-01

    Aquaculture is a major source of invasive aquatic species, despite the fact that cultured organisms often have low genetic diversity and tend to be maladapted to survive in the wild. Yet, to what extent aquaculture escapees become established by means of high propagule pressure and multiple origins is not clear. We analysed the genetic diversity of 15 established populations and four farmed stocks of non-native rainbow trout in Chile, a species first introduced for recreational fishing around 1900, but which has in recent decades escaped in large numbers from fish farms and become widespread. Aquaculture propagule pressure was a good predictor of the incidence of farm escapees, which represented 16% of all free-ranging rainbow trout and were present in 80% of the study rivers. Hybrids between farm escapes and established trout were present in all rivers at frequencies ranging between 7 and 69%, and population admixture was positively correlated with genetic diversity. We suggest that non-native salmonids introduced into the Southern Hemisphere could benefit from admixture because local adaptations may not have yet developed, and there may be initially little fitness loss resulting from outbreeding depression.

  2. The key host for an invasive forest pathogen also facilitates the pathogen's survival of wildfire in California forests.

    PubMed

    Beh, Maia M; Metz, Margaret R; Frangioso, Kerri M; Rizzo, David M

    2012-12-01

    The first wildfires in sudden oak death-impacted forests occurred in 2008 in the Big Sur region of California, creating the rare opportunity to study the interaction between an invasive forest pathogen and a historically recurring disturbance. To determine whether and how the sudden oak death pathogen, Phytophthora ramorum, survived the wildfires, we completed intensive vegetation-based surveys in forest plots that were known to be infested before the wildfires. We then used 24 plot-based variables as predictors of P. ramorum recovery following the wildfires. The likelihood of recovering P. ramorum from burned plots was lower than in unburned plots both 1 and 2 yr following the fires. Post-fire recovery of P. ramorum in burned plots was positively correlated with the number of pre-fire symptomatic California bay laurel (Umbellularia californica), the key sporulating host for this pathogen, and negatively correlated with post-fire bay laurel mortality levels. Patchy burn patterns that left green, P. ramorum-infected bay laurel amidst the charred landscape may have allowed these trees to serve as inoculum reservoirs that could lead to the infection of newly sprouting vegetation, further highlighting the importance of bay laurel in the sudden oak death disease cycle.

  3. Elevated expression level of long noncoding RNA MALAT-1 facilitates cell growth, migration and invasion in pancreatic cancer.

    PubMed

    Jiao, Feng; Hu, Hai; Yuan, Cuncun; Wang, Lei; Jiang, Weihua; Jin, Ziliang; Guo, Zhen; Wang, Liwei

    2014-12-01

    Pancreatic cancer is one of the most aggressive solid malignancies with a dismal survival rate. Recent studies have shown that high expression levels of long noncoding RNA (lncRNA) metastasis-associated lung adenocarcinoma transcript-1 (MALAT-1) correlate with several solid tumors. However, the underlying molecular mechanisms and its clinical significance in pancreatic cancer remain to be elucidated. In the present study, our results showed that MALAT-1 expression levels were upregulated in pancreatic cancer tissues compared with adjacent noncancerous controls. Consistently, higher expression level of MALAT-1 was found in all seven pancreatic cancer cell lines relative to the human pancreatic ductal epithelial cell. Further function analysis revealed that downregulation of MALAT-1 could inhibit tumor cell proliferation and decrease cell migration and invasion in vitro. The underlying mechanisms are possibly involved in inducing G2/M cell cycle arrest, promoting cell apoptosis, suppressing epithelial-mesenchymal transition and reducing cancer stem-like properties. In conclusion, this study indicated that MALAT-1 may serve as an oncogenic lncRNA that is involved in malignancy phenotypes of pancreatic cancer. Therefore, it may be used as a potential therapeutic target.

  4. Acquisition of doxorubicin resistance facilitates migrating and invasive potentials of gastric cancer MKN45 cells through up-regulating aldo-keto reductase 1B10.

    PubMed

    Morikawa, Yoshifumi; Kezuka, Chihiro; Endo, Satoshi; Ikari, Akira; Soda, Midori; Yamamura, Keiko; Toyooka, Naoki; El-Kabbani, Ossama; Hara, Akira; Matsunaga, Toshiyuki

    2015-03-25

    Continuous exposure to doxorubicin (DOX) accelerates hyposensitivity to the drug-elicited lethality of gastric cells, with increased risks of the recurrence and serious cardiovascular side effects. However, the detailed mechanisms underlying the reduction of DOX sensitivity remain unclear. In this study, we generated a DOX-resistant variant upon continuously treating human gastric cancer MKN45 cells with incremental concentrations of the drug, and investigated whether the gain of DOX resistance influences gene expression of four aldo-keto reductases (AKRs: 1B10, 1C1, 1C2 and 1C3). RT-PCR analysis revealed that among the enzymes AKR1B10 is most highly up-regulated during the chemoresistance induction. The up-regulation of AKR1B10 was confirmed by analyses of Western blotting and enzyme activity. The DOX sensitivity of MKN45 cells was reduced and elevated by overexpression and inhibition of AKR1B10, respectively. Compared to the parental MKN45 cells, the DOX-resistant cells had higher migrating and invasive abilities, which were significantly suppressed by addition of AKR1B10 inhibitors. Zymographic and real-time PCR analyses also revealed significant increases in secretion and expression of matrix metalloproteinase (MMP) 2 associated with DOX resistance. Moreover, the overexpression of AKR1B10 in the parental cells remarkably facilitated malignant progression (elevation of migrating and invasive potentials) and MMP2 secretion, which were lowered by the AKR1B10 inhibitors. These results suggest that AKR1B10 is a DOX-resistance gene in the gastric cancer cells, and is responsible for elevating the migrating and invasive potentials of the cells through induction of MMP2. PMID:25686905

  5. Tidal and seasonal effects on survival rates of the endangered California clapper rail: does invasive Spartina facilitate greater survival in a dynamic environment?

    USGS Publications Warehouse

    Overton, Cory T.; Casazza, Michael L.; Takekawa, John Y.; Strong, Donald R.; Holyoak, Marcel

    2014-01-01

    Invasive species frequently degrade habitats, disturb ecosystem processes, and can increase the likelihood of extinction of imperiled populations. However, novel or enhanced functions provided by invading species may reduce the impact of processes that limit populations. It is important to recognize how invasive species benefit endangered species to determine overall effects on sensitive ecosystems. For example, since the 1990s, hybrid Spartina (Spartina foliosa × alterniflora) has expanded throughout South San Francisco Bay, USA, supplanting native vegetation and invading mudflats. The endangered California clapper rail (Rallus longirostris obsoletus) uses the tall, dense hybrid Spartina for cover and nesting, but the effects of hybrid Spartina on clapper rail survival was unknown. We estimated survival rates of 108 radio-marked California clapper rails in South San Francisco Bay from January 2007 to March 2010, a period of extensive hybrid Spartina eradication, with Kaplan–Meier product limit estimators. Clapper rail survival patterns were consistent with hybrid Spartina providing increased refuge cover from predators during tidal extremes which flood native vegetation, particularly during the winter when the vegetation senesces. Model averaged annual survival rates within hybrid Spartina dominated marshes before eradication (Ŝ = 0.466) were greater than the same marshes posttreatment (Ŝ = 0.275) and a marsh dominated by native vegetation (Ŝ = 0.272). However, models with and without marsh treatment as explanatory factor for survival rates had nearly equivalent support in the observed data, lending ambiguity as to whether hybrid Spartina facilitated greater survival rates than native marshland. Conservation actions to aid in recovery of this endangered species should recognize the importance of available of high tide refugia, particularly in light of invasive species eradication programs and projections of future sea-level rise.

  6. Identification of AMPK Phosphorylation Sites Reveals a Network of Proteins Involved in Cell Invasion and Facilitates Large-Scale Substrate Prediction.

    PubMed

    Schaffer, Bethany E; Levin, Rebecca S; Hertz, Nicholas T; Maures, Travis J; Schoof, Michael L; Hollstein, Pablo E; Benayoun, Bérénice A; Banko, Max R; Shaw, Reuben J; Shokat, Kevan M; Brunet, Anne

    2015-11-01

    AMP-activated protein kinase (AMPK) is a central energy gauge that regulates metabolism and has been increasingly involved in non-metabolic processes and diseases. However, AMPK's direct substrates in non-metabolic contexts are largely unknown. To better understand the AMPK network, we use a chemical genetics screen coupled to a peptide capture approach in whole cells, resulting in identification of direct AMPK phosphorylation sites. Interestingly, the high-confidence AMPK substrates contain many proteins involved in cell motility, adhesion, and invasion. AMPK phosphorylation of the RHOA guanine nucleotide exchange factor NET1A inhibits extracellular matrix degradation, an early step in cell invasion. The identification of direct AMPK phosphorylation sites also facilitates large-scale prediction of AMPK substrates. We provide an AMPK motif matrix and a pipeline to predict additional AMPK substrates from quantitative phosphoproteomics datasets. As AMPK is emerging as a critical node in aging and pathological processes, our study identifies potential targets for therapeutic strategies. PMID:26456332

  7. What makes Aspergillus fumigatus a successful pathogen? Genes and molecules involved in invasive aspergillosis.

    PubMed

    Abad, Ana; Fernández-Molina, Jimena Victoria; Bikandi, Joseba; Ramírez, Andoni; Margareto, Javier; Sendino, Javier; Hernando, Fernando Luis; Pontón, Jose; Garaizar, Javier; Rementeria, Aitor

    2010-01-01

    Aspergillus fumigatus is an opportunistic pathogen that causes 90% of invasive aspergillosis (IA) due to Aspergillus genus, with a 50-95% mortality rate. It has been postulated that certain virulence factors are characteristic of A. fumigatus, but the "non-classical" virulence factors seem to be highly variable. Overall, published studies have demonstrated that the virulence of this fungus is multifactorial, associated with its structure, its capacity for growth and adaptation to stress conditions, its mechanisms for evading the immune system and its ability to cause damage to the host. In this review we intend to give a general overview of the genes and molecules involved in the development of IA. The thermotolerance section focuses on five genes related with the capacity of the fungus to grow at temperatures above 30°C (thtA, cgrA, afpmt1, kre2/afmnt1, and hsp1/asp f 12). The following sections discuss molecules and genes related to interaction with the host and with the immune responses. These sections include β-glucan, α-glucan, chitin, galactomannan, galactomannoproteins (afmp1/asp f 17 and afmp2), hydrophobins (rodA/hyp1 and rodB), DHN-melanin, their respective synthases (fks1, rho1-4, ags1-3, chsA-G, och1-4, mnn9, van1, anp1, glfA, pksP/alb1, arp1, arp2, abr1, abr2, and ayg1), and modifying enzymes (gel1-7, bgt1, eng1, ecm33, afpigA, afpmt1-2, afpmt4, kre2/afmnt1, afmnt2-3, afcwh41 and pmi); several enzymes related to oxidative stress protection such as catalases (catA, cat1/catB, cat2/katG, catC, and catE), superoxide dismutases (sod1, sod2, sod3/asp f 6, and sod4), fatty acid oxygenases (ppoA-C), glutathione tranferases (gstA-E), and others (afyap1, skn7, and pes1); and efflux transporters (mdr1-4, atrF, abcA-E, and msfA-E). In addition, this review considers toxins and related genes, such as a diffusible toxic substance from conidia, gliotoxin (gliP and gliZ), mitogillin (res/mitF/asp f 1), hemolysin (aspHS), festuclavine and fumigaclavine A

  8. Metatranscriptomics and Pyrosequencing Facilitate Discovery of Potential Viral Natural Enemies of the Invasive Caribbean Crazy Ant, Nylanderia pubens

    PubMed Central

    Valles, Steven M.; Oi, David H.; Yu, Fahong; Tan, Xin-Xing; Buss, Eileen A.

    2012-01-01

    Background Nylanderia pubens (Forel) is an invasive ant species that in recent years has developed into a serious nuisance problem in the Caribbean and United States. A rapidly expanding range, explosive localized population growth, and control difficulties have elevated this ant to pest status. Professional entomologists and the pest control industry in the United States are urgently trying to understand its biology and develop effective control methods. Currently, no known biological-based control agents are available for use in controlling N. pubens. Methodology and Principal Findings Metagenomics and pyrosequencing techniques were employed to examine the transcriptome of field-collected N. pubens colonies in an effort to identify virus infections with potential to serve as control agents against this pest ant. Pyrosequencing (454-platform) of a non-normalized N. pubens expression library generated 1,306,177 raw sequence reads comprising 450 Mbp. Assembly resulted in generation of 59,017 non-redundant sequences, including 27,348 contigs and 31,669 singlets. BLAST analysis of these non-redundant sequences identified 51 of potential viral origin. Additional analyses winnowed this list of potential viruses to three that appear to replicate in N. pubens. Conclusions Pyrosequencing the transcriptome of field-collected samples of N. pubens has identified at least three sequences that are likely of viral origin and, in which, N. pubens serves as host. In addition, the N. pubens transcriptome provides a genetic resource for the scientific community which is especially important at this early stage of developing a knowledgebase for this new pest. PMID:22384082

  9. Successful Transition to Elementary School and the Implementation of Facilitative Practices Specified in the Reggio-Emilia Philosophy

    ERIC Educational Resources Information Center

    Schneider, Barry H.; Manetti, Mara; Frattini, Laura; Rania, Nadia; Santo, Jonathan Bruce; Coplan, Robert J.; Cwinn, Eli

    2014-01-01

    Systematic, mandated facilitation of school transitions is an important but understudied aspect of the Reggio-Emilia approach to early childhood education admired internationally as best practice. We studied the links between Northern Italian transition practices and academic achievement, school liking, cooperativeness, and problem behaviors. We…

  10. Enhancing Successful Outcomes of Wiki-Based Collaborative Writing: A State-of-the-Art Review of Facilitation Frameworks

    ERIC Educational Resources Information Center

    Stoddart, Andrew; Chan, Joe Yong-Yi; Liu, Gi-Zen

    2016-01-01

    This state-of-the-art review research undertook a survey of a variety of studies regarding wiki-based collaborative writing projects and from this body of work extracted the best practices tenets of facilitation. Wiki-based collaborative writing projects are becoming more common in second language (L2) pedagogy. Such projects have multiple aims.…

  11. Does temperature-mediated reproductive success drive the direction of species displacement in two invasive species of leafminer fly?

    PubMed

    Wang, Haihong; Reitz, Stuart R; Xiang, Juncheng; Smagghe, Guy; Lei, Zhongren

    2014-01-01

    Liriomyza sativae and L. trifolii (Diptera: Agromyzidae) are two highly invasive species of leafmining flies, which have become established as pests of horticultural crops throughout the world. In certain regions where both species have been introduced, L. sativae has displaced L. trifolii, whereas the opposite has occurred in other regions. These opposing outcomes suggest that neither species is an inherently superior competitor. The regions where these displacements have been observed (southern China, Japan and western USA) are climatically different. We determined whether temperature differentially affects the reproductive success of these species and therefore if climatic differences could affect the outcome of interspecific interactions where these species are sympatric. The results of life table parameters indicate that both species can develop successfully at all tested temperatures (20, 25, 31, 33°C). L. sativae had consistently higher fecundities at all temperatures, but L. trifolii developed to reproductive age faster. Age-stage specific survival rates were higher for L. sativae at low temperatures, but these were higher for L. trifolii at higher temperatures. We then compared the net reproductive rates (R0) for both species in pure and mixed cultures maintained at the same four constant temperatures. Both species had significantly lower net reproductive rates in mixed species cultures compared with their respective pure species cultures, indicating that both species are subject to intense interspecific competition. Net reproductive rates were significantly greater for L. sativae than for L. trifolii in mixed species groups at the lower temperatures, whereas the opposite occurred at the higher temperature. Therefore, interactions between the species are temperature dependent and small differences could shift the competitive balance between the species. These temperature mediated effects may contribute to the current ongoing displacement of L. sativae by

  12. Autophagy facilitates TLR4- and TLR3-triggered migration and invasion of lung cancer cells through the promotion of TRAF6 ubiquitination.

    PubMed

    Zhan, Zhenzhen; Xie, Xuefeng; Cao, Hao; Zhou, Xiaohui; Zhang, Xu Dong; Fan, Huimin; Liu, Zhongmin

    2014-02-01

    Autophagy contributes to the pathogenesis of cancer, whereas toll-like receptors (TLRs) also play an important role in cancer development and immune escape. However, little is known about the potential interaction between TLR signaling and autophagy in cancer cells. Here we show that autophagy induced by TLR4 or TLR3 activation enhances various cytokine productions through promoting TRAF6 (TNF receptor-associated factor 6, E3 ubiquitin protein ligase) ubiquitination and thus facilitates migration and invasion of lung cancer cells. Stimulation of TLR4 and TLR3 with lipopolysaccharide (LPS) and polyinosinic-polycytidylic acid [poly(I:C)] respectively triggered autophagy in lung cancer cells. This was mediated by the adaptor protein, toll-like receptor adaptor molecule 1 (TICAM1/TRIF), and was required for TLR4- and TLR3-induced increases in the production of IL6, CCL2/MCP-1 [chemokine (C-C motif) ligand 2], CCL20/MIP-3α [chemokine (C-C motif) ligand 20], VEGFA (vascular endothelial growth factor A), and MMP2 [matrix metallopeptidase 2 (gelatinase A, 72 kDa gelatinase, 72 kDa type IV collagenase)]. These cytokines appeared to be necessary for enhanced migration and invasion of lung cancer cells upon TLR activation. Remarkably, inhibition of autophagy by chemical or genetic approaches blocked TLR4- or TLR3-induced Lys63 (K63)-linked ubiquitination of TRAF6 that was essential for activation of MAPK and NFKB (nuclear factor of kappa light polypeptide gene enhancer in B-cells) pathways, both of which were involved in the increased production of the cytokines. Collectively, these results identify induction of autophagy by TLR4 and TLR3 as an important mechanism that drives lung cancer progression, and indicate that inhibition of autophagy may be a useful strategy in the treatment of lung cancer.

  13. Increase in male reproductive success and female reproductive investment in invasive populations of the harlequin ladybird Harmonia axyridis.

    PubMed

    Laugier, Guillaume J M; Le Moguédec, Gilles; Tayeh, Ashraf; Loiseau, Anne; Osawa, Naoya; Estoup, Arnaud; Facon, Benoît

    2013-01-01

    Reproductive strategy affects population dynamics and genetic parameters that can, in turn, affect evolutionary processes during the course of biological invasion. Life-history traits associated with reproductive strategy are therefore potentially good candidates for rapid evolutionary shifts during invasions. In a series of mating trials, we examined mixed groups of four males from invasive and native populations of the harlequin ladybird Harmonia axyridis mating freely during 48 hours with one female of either type. We recorded the identity of the first male to copulate and after the 48 h-period, we examined female fecundity and share of paternity, using molecular markers. We found that invasive populations have a different profile of male and female reproductive output. Males from invasive populations are more likely to mate first and gain a higher proportion of offspring with both invasive and native females. Females from invasive populations reproduce sooner, lay more eggs, and have offspring sired by a larger number of fathers than females from native populations. We found no evidence of direct inbreeding avoidance behaviour in both invasive and native females. This study highlights the importance of investigating evolutionary changes in reproductive strategy and associated traits during biological invasions. PMID:24204741

  14. Increase in male reproductive success and female reproductive investment in invasive populations of the harlequin ladybird Harmonia axyridis.

    PubMed

    Laugier, Guillaume J M; Le Moguédec, Gilles; Tayeh, Ashraf; Loiseau, Anne; Osawa, Naoya; Estoup, Arnaud; Facon, Benoît

    2013-01-01

    Reproductive strategy affects population dynamics and genetic parameters that can, in turn, affect evolutionary processes during the course of biological invasion. Life-history traits associated with reproductive strategy are therefore potentially good candidates for rapid evolutionary shifts during invasions. In a series of mating trials, we examined mixed groups of four males from invasive and native populations of the harlequin ladybird Harmonia axyridis mating freely during 48 hours with one female of either type. We recorded the identity of the first male to copulate and after the 48 h-period, we examined female fecundity and share of paternity, using molecular markers. We found that invasive populations have a different profile of male and female reproductive output. Males from invasive populations are more likely to mate first and gain a higher proportion of offspring with both invasive and native females. Females from invasive populations reproduce sooner, lay more eggs, and have offspring sired by a larger number of fathers than females from native populations. We found no evidence of direct inbreeding avoidance behaviour in both invasive and native females. This study highlights the importance of investigating evolutionary changes in reproductive strategy and associated traits during biological invasions.

  15. Barriers and facilitators for promotoras' success in delivering pesticide safety education to Latino farmworker families: La Familia Sana.

    PubMed

    Trejo, Grisel; Arcury, Thomas A; Grzywacz, Joseph G; Tapia, Janeth; Quandt, Sara A

    2013-01-01

    Despite widespread use of lay health advisor (LHA) programs, factors related to success of LHAs remain largely unexamined. This study describes experiences and personal transformations of LHAs (promotoras de salud) in a pesticide safety education program targeting farmworker families in North Carolina, using postintervention in-depth interviews conducted with 17 LHAs. LHAs identified assets and barriers that affected their success. LHAs also described increases in self-efficacy and empowerment resulting in perceived improvements in ability to teach and impact their community. Such positive changes are essential benefits to the LHAs. Evaluations that address these topics are needed to better understand continuity and attrition in LHA programs.

  16. Long live the alien: is high genetic diversity a pivotal aspect of crested porcupine (Hystrix cristata) long-lasting and successful invasion?

    PubMed

    Trucchi, Emiliano; Facon, Benoit; Gratton, Paolo; Mori, Emiliano; Stenseth, Nils Chr; Jentoft, Sissel

    2016-08-01

    Studying the evolutionary dynamics of an alien species surviving and continuing to expand after several generations can provide fundamental information on the relevant features of clearly successful invasions. Here, we tackle this task by investigating the dynamics of the genetic diversity in invasive crested porcupine (Hystrix cristata) populations, introduced to Italy about 1500 years ago, which are still growing in size, distribution range and ecological niche. Using genome-wide RAD markers, we describe the structure of the genetic diversity and the demographic dynamics of the H. cristata invasive populations and compare their genetic diversity with that of native African populations of both H. cristata and its sister species, H. africaeaustralis. First, we demonstrate that genetic diversity is lower in both the invasive Italian and the North Africa source range relative to other native populations from sub-Saharan and South Africa. Second, we find evidence of multiple introduction events in the invasive range followed by very limited gene flow. Through coalescence-based demographic reconstructions, we also show that the bottleneck at introduction was mild and did not affect the introduced genetic diversity. Finally, we reveal that the current spatial expansion at the northern boundary of the range is following a leading-edge model characterized by a general reduction of genetic diversity towards the edge of the expanding range. We conclude that the level of genome-wide diversity of H. cristata invasive populations is less important in explaining its successful invasion than species-specific life-history traits or the phylogeographic history in the native source range. PMID:27171527

  17. Long live the alien: is high genetic diversity a pivotal aspect of crested porcupine (Hystrix cristata) long-lasting and successful invasion?

    PubMed

    Trucchi, Emiliano; Facon, Benoit; Gratton, Paolo; Mori, Emiliano; Stenseth, Nils Chr; Jentoft, Sissel

    2016-08-01

    Studying the evolutionary dynamics of an alien species surviving and continuing to expand after several generations can provide fundamental information on the relevant features of clearly successful invasions. Here, we tackle this task by investigating the dynamics of the genetic diversity in invasive crested porcupine (Hystrix cristata) populations, introduced to Italy about 1500 years ago, which are still growing in size, distribution range and ecological niche. Using genome-wide RAD markers, we describe the structure of the genetic diversity and the demographic dynamics of the H. cristata invasive populations and compare their genetic diversity with that of native African populations of both H. cristata and its sister species, H. africaeaustralis. First, we demonstrate that genetic diversity is lower in both the invasive Italian and the North Africa source range relative to other native populations from sub-Saharan and South Africa. Second, we find evidence of multiple introduction events in the invasive range followed by very limited gene flow. Through coalescence-based demographic reconstructions, we also show that the bottleneck at introduction was mild and did not affect the introduced genetic diversity. Finally, we reveal that the current spatial expansion at the northern boundary of the range is following a leading-edge model characterized by a general reduction of genetic diversity towards the edge of the expanding range. We conclude that the level of genome-wide diversity of H. cristata invasive populations is less important in explaining its successful invasion than species-specific life-history traits or the phylogeographic history in the native source range.

  18. Facilitative ecological interactions between invasive species: Arundo donax stands as favorable habitat for cattle ticks (Acari: Ixodidae) along the U.S.-Mexico border.

    PubMed

    Racelis, A E; Davey, R B; Goolsby, J A; Pérez de León, A A; Varner, K; Duhaime, R

    2012-03-01

    The cattle tick, Rhipicephalus (Boophilus) spp. is a key vector of protozoa that cause bovine babesiosis. Largely eradicated from most of the United States, the cattle tick continues to infest south Texas, and recent outbreaks in this area may signal a resurgence of cattle tick populations despite current management efforts. An improved understanding of the dynamic ecology of cattle fever ticks along the U.S.-Mexico border is required to devise strategies for sustainable eradication efforts. Management areas of the cattle tick overlap considerably with dense, wide infestations of the non-native, invasive grass known as giant reed (Arundo donax L.). Here we show that stands of giant reed are associated with abiotic and biotic conditions that are favorable to tick survival, especially when compared with other nearby habitats (open pastures of buffelgrass (Pennisetum ciliare) and closed canopy native forests). Overhead canopies in giant reed stands and native riparian forests reduce daily high temperature, which was the best abiotic predictor of oviposition by engorged females. In sites where temperatures were extreme, specifically open grasslands, fewer females laid eggs and the resulting egg masses were smaller. Pitfall trap collections of ground dwelling arthropods suggest a low potential for natural suppression of tick populations in giant reed stands. The finding that A. donax infestations present environmental conditions that facilitate the survival and persistence of cattle ticks, as well or better than native riparian habitats and open grasslands, represents an alarming complication for cattle fever tick management in the United States.

  19. Facilitating Surveillance of Pulmonary Invasive Mold Diseases in Patients with Haematological Malignancies by Screening Computed Tomography Reports Using Natural Language Processing

    PubMed Central

    Ananda-Rajah, Michelle R.; Martinez, David; Slavin, Monica A.; Cavedon, Lawrence; Dooley, Michael; Cheng, Allen; Thursky, Karin A.

    2014-01-01

    Purpose Prospective surveillance of invasive mold diseases (IMDs) in haematology patients should be standard of care but is hampered by the absence of a reliable laboratory prompt and the difficulty of manual surveillance. We used a high throughput technology, natural language processing (NLP), to develop a classifier based on machine learning techniques to screen computed tomography (CT) reports supportive for IMDs. Patients and Methods We conducted a retrospective case-control study of CT reports from the clinical encounter and up to 12-weeks after, from a random subset of 79 of 270 case patients with 33 probable/proven IMDs by international definitions, and 68 of 257 uninfected-control patients identified from 3 tertiary haematology centres. The classifier was trained and tested on a reference standard of 449 physician annotated reports including a development subset (n = 366), from a total of 1880 reports, using 10-fold cross validation, comparing binary and probabilistic predictions to the reference standard to generate sensitivity, specificity and area under the receiver-operating-curve (ROC). Results For the development subset, sensitivity/specificity was 91% (95%CI 86% to 94%)/79% (95%CI 71% to 84%) and ROC area was 0.92 (95%CI 89% to 94%). Of 25 (5.6%) missed notifications, only 4 (0.9%) reports were regarded as clinically significant. Conclusion CT reports are a readily available and timely resource that may be exploited by NLP to facilitate continuous prospective IMD surveillance with translational benefits beyond surveillance alone. PMID:25250675

  20. Facilitative ecological interactions between invasive species: Arundo donax stands as favorable habitat for cattle ticks (Acari: Ixodidae) along the U.S.-Mexico border.

    PubMed

    Racelis, A E; Davey, R B; Goolsby, J A; Pérez de León, A A; Varner, K; Duhaime, R

    2012-03-01

    The cattle tick, Rhipicephalus (Boophilus) spp. is a key vector of protozoa that cause bovine babesiosis. Largely eradicated from most of the United States, the cattle tick continues to infest south Texas, and recent outbreaks in this area may signal a resurgence of cattle tick populations despite current management efforts. An improved understanding of the dynamic ecology of cattle fever ticks along the U.S.-Mexico border is required to devise strategies for sustainable eradication efforts. Management areas of the cattle tick overlap considerably with dense, wide infestations of the non-native, invasive grass known as giant reed (Arundo donax L.). Here we show that stands of giant reed are associated with abiotic and biotic conditions that are favorable to tick survival, especially when compared with other nearby habitats (open pastures of buffelgrass (Pennisetum ciliare) and closed canopy native forests). Overhead canopies in giant reed stands and native riparian forests reduce daily high temperature, which was the best abiotic predictor of oviposition by engorged females. In sites where temperatures were extreme, specifically open grasslands, fewer females laid eggs and the resulting egg masses were smaller. Pitfall trap collections of ground dwelling arthropods suggest a low potential for natural suppression of tick populations in giant reed stands. The finding that A. donax infestations present environmental conditions that facilitate the survival and persistence of cattle ticks, as well or better than native riparian habitats and open grasslands, represents an alarming complication for cattle fever tick management in the United States. PMID:22493861

  1. Extreme Environments Facilitate Hybrid Superiority – The Story of a Successful Daphnia galeata × longispina Hybrid Clone

    PubMed Central

    Griebel, Johanna; Gießler, Sabine; Poxleitner, Monika; Navas Faria, Amanda; Yin, Mingbo; Wolinska, Justyna

    2015-01-01

    Hybridization within the animal kingdom has long been underestimated. Hybrids have often been considered less fit than their parental species. In the present study, we observed that the Daphnia community of a small lake was dominated by a single D. galeata × D. longispina hybrid clone, during two consecutive years. Notably, in artificial community set-ups consisting of several clones representing parental species and other hybrids, this hybrid clone took over within about ten generations. Neither the fitness assay conducted under different temperatures, or under crowded and non-crowded environments, nor the carrying capacity test revealed any outstanding life history parameters of this hybrid clone. However, under simulated winter conditions (i.e. low temperature, food and light), the hybrid clone eventually showed a higher survival probability and higher fecundity compared to parental species. Hybrid superiority in cold-adapted traits leading to an advantage of overwintering as parthenogenetic lineages might consequently explain the establishment of successful hybrids in natural communities of the D. longispina complex. In extreme cases, like the one reported here, a superior hybrid genotype might be the only clone alive after cold winters. Overall, superiority traits, such as enhanced overwintering here, might explain hybrid dominance in nature, especially in extreme and rapidly changing environments. Although any favoured gene complex in cyclic parthenogens could be frozen in successful clones independent of hybridization, we did not find similarly successful clones among parental species. We conclude that the emergence of the observed trait is linked to the production of novel recombined hybrid genotypes. PMID:26448651

  2. Soil modification by invasive plants: Effects on native and invasive species of mixed-grass prairies

    USGS Publications Warehouse

    Jordan, N.R.; Larson, D.L.; Huerd, S.C.

    2008-01-01

    Invasive plants are capable of modifying attributes of soil to facilitate further invasion by conspecifics and other invasive species. We assessed this capability in three important plant invaders of grasslands in the Great Plains region of North America: leafy spurge (Euphorbia esula), smooth brome (Bromus inermis) and crested wheatgrass (Agropyron cristatum). In a glasshouse, these three invasives or a group of native species were grown separately through three cycles of growth and soil conditioning in both steam-pasteurized and non-pasteurized soils, after which we assessed seedling growth in these soils. Two of the three invasive species, Bromus and Agropyron, exhibited significant self-facilitation via soil modification. Bromus and Agropyron also had significant facilitative effects on other invasives via soil modification, while Euphorbia had significant antagonistic effects on the other invasives. Both Agropyron and Euphorbia consistently suppressed growth of two of three native forbs, while three native grasses were generally less affected. Almost all intra- and interspecific effects of invasive soil conditioning were dependent upon presence of soil biota from field sites where these species were successful invaders. Overall, these results suggest that that invasive modification of soil microbiota can facilitate plant invasion directly or via 'cross-facilitation' of other invasive species, and moreover has potential to impede restoration of native communities after removal of an invasive species. However, certain native species that are relatively insensitive to altered soil biota (as we observed in the case of the forb Linum lewisii and the native grasses), may be valuable as 'nurse'species in restoration efforts. ?? 2007 Springer Science+Business Media B.V.

  3. Fibrin glue coating of the surgical surfaces may facilitate formation of a successful bleb in trabeculectomy surgery.

    PubMed

    Sakarya, Yasar; Sakarya, Rabia; Kara, Selcuk; Soylu, Tulay

    2011-08-01

    Trabeculectomy is commonly conducted when medical therapy fails to control intraocular pressure (IOP). The success of trabeculectomy for the treatment of glaucoma depends on the wound-healing response at the subconjunctival filtering bleb site. Postoperative scar formation is a serious problem in this surgery. Current strategies to counteract scarring include local antimetabolite treatment, which is associated with severe side effects, limiting its application. Therefore, additional means to safely modulate wound healing are desirable. In ophthalmic surgery, fibrin glue is used mainly for sealing and hemostatics purpose. Fibrin glue coating of tenon face of conjunctiva, scleral surface, reverse face of scleral flap and scleral bed with insoluble fibrin glue can halt both ooze bleeding and vascular leakage. By retarding the first step of wound healing, less postoperative inflammation may occur. Additionally aqueous humor flows through a fibrin glue coated interface. Therefore, we hypothesize that fibrin glue coating of the surgical surfaces in trabeculectomy surgery may yield less subconjunctival fibrosis and more successful bleb. To the best of our knowledge, no basic research has yet been performed regarding fibrin glue coating for halting the vascular leakage and easing the aqueous drainage into subconjunctival space in glaucoma surgery.

  4. Low Genetic Diversity and High Invasion Success of Corbicula fluminea (Bivalvia, Corbiculidae) (Müller, 1774) in Portugal

    PubMed Central

    Gomes, Cidália; Sousa, Ronaldo; Mendes, Tito; Borges, Rui; Vilares, Pedro; Vasconcelos, Vitor; Guilhermino, Lúcia; Antunes, Agostinho

    2016-01-01

    The Asian clam, Corbicula fluminea, is an invasive alien species (IAS) originally from Asia that has spread worldwide causing major ecological and economic impacts in aquatic ecosystems. Here, we evaluated C. fluminea genetic (using COI mtDNA, CYTb mtDNA and 18S rDNA gene markers), morphometric and sperm morphology variation in Portuguese freshwater ecosystems. The COI marker revealed a single haplotype, which belongs to the Asian FW5 invasive lineage, suggesting a common origin for all the 13 Portuguese C. fluminea populations analysed. Morphometric analyses showed differences between the populations colonizing the North (with the exception of the Lima River) and the Centre/South ecosystems. The sperm morphology examination revealed the presence of biflagellate sperm, a distinctive character of the invasive androgenetic lineages. The low genetic variability of the Portuguese C. fluminea populations and the pattern of sperm morphology have been illuminating for understanding the demographic history of this invasive species. We hypothesize that these populations were derived from a unique introductory event of a Corbicula fluminea FW5 invasive androgenic lineage in the Tejo River, which subsequently dispersed to other Portuguese freshwater ecosystems. The C. fluminea asexual reproductive mode may have assisted these populations to become highly invasive despite the low genetic diversity. PMID:27391333

  5. Low Genetic Diversity and High Invasion Success of Corbicula fluminea (Bivalvia, Corbiculidae) (Müller, 1774) in Portugal.

    PubMed

    Gomes, Cidália; Sousa, Ronaldo; Mendes, Tito; Borges, Rui; Vilares, Pedro; Vasconcelos, Vitor; Guilhermino, Lúcia; Antunes, Agostinho

    2016-01-01

    The Asian clam, Corbicula fluminea, is an invasive alien species (IAS) originally from Asia that has spread worldwide causing major ecological and economic impacts in aquatic ecosystems. Here, we evaluated C. fluminea genetic (using COI mtDNA, CYTb mtDNA and 18S rDNA gene markers), morphometric and sperm morphology variation in Portuguese freshwater ecosystems. The COI marker revealed a single haplotype, which belongs to the Asian FW5 invasive lineage, suggesting a common origin for all the 13 Portuguese C. fluminea populations analysed. Morphometric analyses showed differences between the populations colonizing the North (with the exception of the Lima River) and the Centre/South ecosystems. The sperm morphology examination revealed the presence of biflagellate sperm, a distinctive character of the invasive androgenetic lineages. The low genetic variability of the Portuguese C. fluminea populations and the pattern of sperm morphology have been illuminating for understanding the demographic history of this invasive species. We hypothesize that these populations were derived from a unique introductory event of a Corbicula fluminea FW5 invasive androgenic lineage in the Tejo River, which subsequently dispersed to other Portuguese freshwater ecosystems. The C. fluminea asexual reproductive mode may have assisted these populations to become highly invasive despite the low genetic diversity. PMID:27391333

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

    USGS Publications Warehouse

    Simpson, A.; Jarnevich, C.; Madsen, J.; Westbrooks, R.; Fournier, C.; Mehrhoff, L.; Browne, M.; Graham, J.; Sellers, E.

    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

  7. Intrinsic monitoring of learning success facilitates memory encoding via the activation of the SN/VTA-Hippocampal loop

    PubMed Central

    Ripollés, Pablo; Marco-Pallarés, Josep; Alicart, Helena; Tempelmann, Claus; Rodríguez-Fornells, Antoni; Noesselt, Toemme

    2016-01-01

    Humans constantly learn in the absence of explicit rewards. However, the neurobiological mechanisms supporting this type of internally-guided learning (without explicit feedback) are still unclear. Here, participants who completed a task in which no external reward/feedback was provided, exhibited enhanced fMRI-signals within the dopaminergic midbrain, hippocampus, and ventral striatum (the SN/VTA-Hippocampal loop) when successfully grasping the meaning of new-words. Importantly, new-words that were better remembered showed increased activation and enhanced functional connectivity between the midbrain, hippocampus, and ventral striatum. Moreover, enhanced emotion-related physiological measures and subjective pleasantness ratings during encoding were associated with remembered new-words after 24 hr. Furthermore, increased subjective pleasantness ratings were also related to new-words remembered after seven days. These results suggest that intrinsic—potentially reward-related—signals, triggered by self-monitoring of correct performance, can promote the storage of new information into long-term memory through the activation of the SN/VTA-Hippocampal loop, possibly via dopaminergic modulation of the midbrain. DOI: http://dx.doi.org/10.7554/eLife.17441.001 PMID:27644419

  8. Intrinsic monitoring of learning success facilitates memory encoding via the activation of the SN/VTA-Hippocampal loop.

    PubMed

    Ripollés, Pablo; Marco-Pallarés, Josep; Alicart, Helena; Tempelmann, Claus; Rodríguez-Fornells, Antoni; Noesselt, Toemme

    2016-01-01

    Humans constantly learn in the absence of explicit rewards. However, the neurobiological mechanisms supporting this type of internally-guided learning (without explicit feedback) are still unclear. Here, participants who completed a task in which no external reward/feedback was provided, exhibited enhanced fMRI-signals within the dopaminergic midbrain, hippocampus, and ventral striatum (the SN/VTA-Hippocampal loop) when successfully grasping the meaning of new-words. Importantly, new-words that were better remembered showed increased activation and enhanced functional connectivity between the midbrain, hippocampus, and ventral striatum. Moreover, enhanced emotion-related physiological measures and subjective pleasantness ratings during encoding were associated with remembered new-words after 24 hr. Furthermore, increased subjective pleasantness ratings were also related to new-words remembered after seven days. These results suggest that intrinsic-potentially reward-related-signals, triggered by self-monitoring of correct performance, can promote the storage of new information into long-term memory through the activation of the SN/VTA-Hippocampal loop, possibly via dopaminergic modulation of the midbrain. PMID:27644419

  9. Intrinsic monitoring of learning success facilitates memory encoding via the activation of the SN/VTA-Hippocampal loop.

    PubMed

    Ripollés, Pablo; Marco-Pallarés, Josep; Alicart, Helena; Tempelmann, Claus; Rodríguez-Fornells, Antoni; Noesselt, Toemme

    2016-09-20

    Humans constantly learn in the absence of explicit rewards. However, the neurobiological mechanisms supporting this type of internally-guided learning (without explicit feedback) are still unclear. Here, participants who completed a task in which no external reward/feedback was provided, exhibited enhanced fMRI-signals within the dopaminergic midbrain, hippocampus, and ventral striatum (the SN/VTA-Hippocampal loop) when successfully grasping the meaning of new-words. Importantly, new-words that were better remembered showed increased activation and enhanced functional connectivity between the midbrain, hippocampus, and ventral striatum. Moreover, enhanced emotion-related physiological measures and subjective pleasantness ratings during encoding were associated with remembered new-words after 24 hr. Furthermore, increased subjective pleasantness ratings were also related to new-words remembered after seven days. These results suggest that intrinsic-potentially reward-related-signals, triggered by self-monitoring of correct performance, can promote the storage of new information into long-term memory through the activation of the SN/VTA-Hippocampal loop, possibly via dopaminergic modulation of the midbrain.

  10. Different effects of invader-native phylogenetic relatedness on invasion success and impact: a meta-analysis of Darwin's naturalization hypothesis.

    PubMed

    Ma, Chao; Li, Shao-Peng; Pu, Zhichao; Tan, Jiaqi; Liu, Manqiang; Zhou, Jing; Li, Huixin; Jiang, Lin

    2016-09-14

    Darwin's naturalization hypothesis (DNH), which predicts that alien species more distantly related to native communities are more likely to naturalize, has received much recent attention. The mixed findings from empirical studies that have tested DNH, however, seem to defy generalizations. Using meta-analysis to synthesize results of existing studies, we show that the predictive power of DNH depends on both the invasion stage and the spatial scale of the studies. Alien species more closely related to natives tended to be less successful at the local scale, supporting DNH; invasion success, however, was unaffected by alien-native relatedness at the regional scale. On the other hand, alien species with stronger impacts on native communities tended to be more closely related to natives at the local scale, but less closely related to natives at the regional scale. These patterns are generally consistent across different ecosystems, taxa and investigation methods. Our results revealed the different effects of invader-native relatedness on invader success and impact, suggesting the operation of different mechanisms across invasion stages and spatial scales. PMID:27605502

  11. Different effects of invader-native phylogenetic relatedness on invasion success and impact: a meta-analysis of Darwin's naturalization hypothesis.

    PubMed

    Ma, Chao; Li, Shao-Peng; Pu, Zhichao; Tan, Jiaqi; Liu, Manqiang; Zhou, Jing; Li, Huixin; Jiang, Lin

    2016-09-14

    Darwin's naturalization hypothesis (DNH), which predicts that alien species more distantly related to native communities are more likely to naturalize, has received much recent attention. The mixed findings from empirical studies that have tested DNH, however, seem to defy generalizations. Using meta-analysis to synthesize results of existing studies, we show that the predictive power of DNH depends on both the invasion stage and the spatial scale of the studies. Alien species more closely related to natives tended to be less successful at the local scale, supporting DNH; invasion success, however, was unaffected by alien-native relatedness at the regional scale. On the other hand, alien species with stronger impacts on native communities tended to be more closely related to natives at the local scale, but less closely related to natives at the regional scale. These patterns are generally consistent across different ecosystems, taxa and investigation methods. Our results revealed the different effects of invader-native relatedness on invader success and impact, suggesting the operation of different mechanisms across invasion stages and spatial scales.

  12. Prey interception drives web invasion and spider size determines successful web takeover in nocturnal orb-web spiders

    PubMed Central

    Gan, Wenjin; Liu, Shengjie; Yang, Xiaodong; Li, Daiqin; Lei, Chaoliang

    2015-01-01

    ABSTRACT A striking feature of web-building spiders is the use of silk to make webs, mainly for prey capture. However, building a web is energetically expensive and increases the risk of predation. To reduce such costs and still have access to abundant prey, some web-building spiders have evolved web invasion behaviour. In general, no consistent patterns of web invasion have emerged and the factors determining web invasion remain largely unexplored. Here we report web invasion among conspecifics in seven nocturnal species of orb-web spiders, and examined the factors determining the probability of webs that could be invaded and taken over by conspecifics. About 36% of webs were invaded by conspecifics, and 25% of invaded webs were taken over by the invaders. A web that was built higher and intercepted more prey was more likely to be invaded. Once a web was invaded, the smaller the size of the resident spider, the more likely its web would be taken over by the invader. This study suggests that web invasion, as a possible way of reducing costs, may be widespread in nocturnal orb-web spiders. PMID:26405048

  13. Prey interception drives web invasion and spider size determines successful web takeover in nocturnal orb-web spiders.

    PubMed

    Gan, Wenjin; Liu, Shengjie; Yang, Xiaodong; Li, Daiqin; Lei, Chaoliang

    2015-09-24

    A striking feature of web-building spiders is the use of silk to make webs, mainly for prey capture. However, building a web is energetically expensive and increases the risk of predation. To reduce such costs and still have access to abundant prey, some web-building spiders have evolved web invasion behaviour. In general, no consistent patterns of web invasion have emerged and the factors determining web invasion remain largely unexplored. Here we report web invasion among conspecifics in seven nocturnal species of orb-web spiders, and examined the factors determining the probability of webs that could be invaded and taken over by conspecifics. About 36% of webs were invaded by conspecifics, and 25% of invaded webs were taken over by the invaders. A web that was built higher and intercepted more prey was more likely to be invaded. Once a web was invaded, the smaller the size of the resident spider, the more likely its web would be taken over by the invader. This study suggests that web invasion, as a possible way of reducing costs, may be widespread in nocturnal orb-web spiders.

  14. Prey interception drives web invasion and spider size determines successful web takeover in nocturnal orb-web spiders.

    PubMed

    Gan, Wenjin; Liu, Shengjie; Yang, Xiaodong; Li, Daiqin; Lei, Chaoliang

    2015-01-01

    A striking feature of web-building spiders is the use of silk to make webs, mainly for prey capture. However, building a web is energetically expensive and increases the risk of predation. To reduce such costs and still have access to abundant prey, some web-building spiders have evolved web invasion behaviour. In general, no consistent patterns of web invasion have emerged and the factors determining web invasion remain largely unexplored. Here we report web invasion among conspecifics in seven nocturnal species of orb-web spiders, and examined the factors determining the probability of webs that could be invaded and taken over by conspecifics. About 36% of webs were invaded by conspecifics, and 25% of invaded webs were taken over by the invaders. A web that was built higher and intercepted more prey was more likely to be invaded. Once a web was invaded, the smaller the size of the resident spider, the more likely its web would be taken over by the invader. This study suggests that web invasion, as a possible way of reducing costs, may be widespread in nocturnal orb-web spiders. PMID:26405048

  15. Government success in partnerships: The USDA-ARS areawide ecologically-based invasive annual grass management program

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Areawide partnership of researchers, educators and ranchers have been implementing an Areawide Pest Management project over the past three years to catalyze the adoption of ecologically-based invasive annual grass management across the western US. The program includes the establishment of watershed-...

  16. Foraging Behavior Interactions Between Two non-Native Social Wasps, Vespula germanica and V. vulgaris (Hymenoptera: Vespidae): Implications for Invasion Success?

    PubMed

    Pereira, Ana Julia; Pirk, Gabriela I; Corley, Juan C

    2016-01-01

    Vespula vulgaris is an invasive scavenging social wasp that has very recently arrived in Patagonia (Argentina), a territory previously invaded - 35 yrs earlier - by another wasp, Vespula germanica Although V. vulgaris wasps possess features that could be instrumental in overcoming obstacles through several invasion stages, the presence of preestablished populations of V. germanica could affect their success. We studied the potential role played by V. germanica on the subsequent invasion process of V. vulgaris wasps in Patagonia by focusing on the foraging interaction between both species. This is because food searching and exploitation are likely to overlap strongly among Vespula wasps. We carried out choice tests where two types of baits were presented in a pairwise manner. We found experimental evidence supporting the hypothesis that V. germanica and V. vulgaris have an asymmetrical response to baits with stimuli simulating the presence of each other. V. germanica avoided baits with either visual or olfactory cues indicating the V. vulgaris presence. However, V. vulgaris showed no preference between baits with or lacking V. germanica stimuli. These results suggest that the presence of an established population of V. germanica may not contribute to added biotic resistance to V. vulgaris invasion.

  17. Foraging Behavior Interactions Between Two non-Native Social Wasps, Vespula germanica and V. vulgaris (Hymenoptera: Vespidae): Implications for Invasion Success?

    PubMed Central

    Pereira, Ana Julia; Corley, Juan C.

    2016-01-01

    Vespula vulgaris is an invasive scavenging social wasp that has very recently arrived in Patagonia (Argentina), a territory previously invaded – 35 yrs earlier – by another wasp, Vespula germanica. Although V. vulgaris wasps possess features that could be instrumental in overcoming obstacles through several invasion stages, the presence of preestablished populations of V. germanica could affect their success. We studied the potential role played by V. germanica on the subsequent invasion process of V. vulgaris wasps in Patagonia by focusing on the foraging interaction between both species. This is because food searching and exploitation are likely to overlap strongly among Vespula wasps. We carried out choice tests where two types of baits were presented in a pairwise manner. We found experimental evidence supporting the hypothesis that V. germanica and V. vulgaris have an asymmetrical response to baits with stimuli simulating the presence of each other. V. germanica avoided baits with either visual or olfactory cues indicating the V. vulgaris presence. However, V. vulgaris showed no preference between baits with or lacking V. germanica stimuli. These results suggest that the presence of an established population of V. germanica may not contribute to added biotic resistance to V. vulgaris invasion. PMID:27503470

  18. Foraging Behavior Interactions Between Two non-Native Social Wasps, Vespula germanica and V. vulgaris (Hymenoptera: Vespidae): Implications for Invasion Success?

    PubMed

    Pereira, Ana Julia; Pirk, Gabriela I; Corley, Juan C

    2016-01-01

    Vespula vulgaris is an invasive scavenging social wasp that has very recently arrived in Patagonia (Argentina), a territory previously invaded - 35 yrs earlier - by another wasp, Vespula germanica Although V. vulgaris wasps possess features that could be instrumental in overcoming obstacles through several invasion stages, the presence of preestablished populations of V. germanica could affect their success. We studied the potential role played by V. germanica on the subsequent invasion process of V. vulgaris wasps in Patagonia by focusing on the foraging interaction between both species. This is because food searching and exploitation are likely to overlap strongly among Vespula wasps. We carried out choice tests where two types of baits were presented in a pairwise manner. We found experimental evidence supporting the hypothesis that V. germanica and V. vulgaris have an asymmetrical response to baits with stimuli simulating the presence of each other. V. germanica avoided baits with either visual or olfactory cues indicating the V. vulgaris presence. However, V. vulgaris showed no preference between baits with or lacking V. germanica stimuli. These results suggest that the presence of an established population of V. germanica may not contribute to added biotic resistance to V. vulgaris invasion. PMID:27503470

  19. The presence of co-flowering species facilitates reproductive success of Pedicularis monbeigiana (Orobanchaceae) through variation in bumble-bee foraging behaviour

    PubMed Central

    Liao, Kuo; Gituru, Robert W.; Guo, You-Hao; Wang, Qing-Feng

    2011-01-01

    Background and Aims The presence of co-flowering species can alter pollinator foraging behaviour and, in turn, positively or negatively affect the reproductive success of the focal species. Such interactions were investigated between a focal species, Pedicularis monbeigiana, and a co-flowering species, Vicia dichroantha, which was mediated by behaviour alteration of the shared bumble-bee pollinator. Methods Floral display size and floral colour change of P. monbeigiana were compared between pure (P. monbeigiana only) and mixed (P. monbeigiana and V. dichroantha) plots in two populations. Pollinator visitation rates, interspecific floral switching and successive within-plant pollinator visits were recorded. In addition, supplemental pollination at plant level was performed, and the fruit set and seed set were analysed in pure and mixed plots with different densities of P. monbeigiana. Key Results Pollinator visitation rates were dramatically higher in mixed plots than in pure plots. The higher pollinator visitation rates were recorded in both low- and high-density plots. In particular, successive flower visits within an individual plant were significantly lower in mixed plots. Supplemental pollination significantly increased fruit set and seed set of individuals in pure plots, while it only marginally increased seed set per fruit of plants in mixed plots. Conclusions The presence of V. dichroantha can facilitate pollination and increase female reproductive success of P. monbeigiana via both quantity (mitigating pollinator limitation) and quality (reducing geitonogamy) effects. This study suggests that successive pollinator movements among flowers within a plant, as well as pollinator visitation rates and interspecific flower switching, may be important determinants of the direction and mechanisms of interaction between species. PMID:21831855

  20. Evaluating the Interacting Influences of Pollination, Seed Predation, Invasive Species and Isolation on Reproductive Success in a Threatened Alpine Plant

    PubMed Central

    Krushelnycky, Paul D.

    2014-01-01

    Reproduction in rare plants may be influenced and limited by a complex combination of factors. External threats such as invasive species and landscape characteristics such as isolation may impinge on both pollination and seed predation dynamics, which in turn can strongly affect reproduction. I assessed how patterns in floral visitation, seed predation, invasive ant presence, and plant isolation influenced one another and ultimately affected viable seed production in Haleakalā silverswords (Argyroxiphium sandwicense subsp. macrocephalum) of Hawai’i. Floral visitation was dominated by endemic Hylaeus bees, and patterns of visitation were influenced by floral display size and number of plants clustered together, but not by floral herbivory or nearest flowering neighbor distance. There was also some indication that Argentine ant presence impacted floral visitation, but contradictory evidence and limitations of the study design make this result uncertain. Degree of seed predation was associated only with plant isolation, with the two main herbivores partitioning resources such that one preferentially attacked isolated plants while the other attacked clumped plants; total seed predation was greater in more isolated plants. Net viable seed production was highly variable among individuals (0–55% seed set), and was affected mainly by nearest neighbor distance, apparently owing to low cross-pollination among plants separated by even short distances (>10–20 m). This isolation effect dominated net seed set, with no apparent influence from floral visitation rates, percent seed predation, or invasive ant presence. The measured steep decline in seed set with isolation distance may not be typical of the entire silversword range, and may indicate that pollinators in addition to Hylaeus bees could be important for greater gene flow. Management aimed at maintaining or maximizing silversword reproduction should focus on the spatial context of field populations and outplanting

  1. Effects of natural flooding and manual trapping on the facilitation of invasive crayfish-native amphibian coexistence in a semi-arid perennial stream

    USGS Publications Warehouse

    Kats, Lee B.; Bucciarelli, Gary; Vandergon, Thomas L.; Honeycutt, Rodney L.; Mattiasen, Evan; Sanders, Arthur; Riley, Seth P.D.; Kerby, Jacob L.; Fisher, Robert N.

    2013-01-01

    Aquatic amphibians are known to be vulnerable to a myriad of invasive predators. Invasive crayfish are thought to have eliminated native populations of amphibians in some streams in the semi-arid Santa Monica Mountains of southern California. Despite their toxic skin secretions that defend them from native predators, newts are vulnerable to crayfish attacks, and crayfish have been observed attacking adult newts, and eating newt egg masses and larvae. For 15 years, we have observed invasive crayfish and native California newts coexisting in one stream in the Santa Monica Mountains. During that period, we monitored the densities of both crayfish and newt egg mass densities and compared these to annual rainfall totals. After three seasons of below average rainfall, we reduced crayfish numbers by manual trapping. Our long-term data indicated that crayfish did not fare well in years when rainfall is above the historic average. This invasive predator did not evolve with high velocity streams, and observations indicated that southern California storm events washed crayfish downstream, killing many of them. Newts exhibit increased reproduction in years when crayfish numbers were reduced. A comparison with a nearby stream that does not contain crayfish indicated that newt reproduction positively responded to increased rainfall, but that fluctuations were much greater in the stream that contains crayfish. We suggest that rainfall patterns help explain invasive crayfish/newt coexistence and that management for future coexistence may benefit from manual trapping.

  2. Preference of a native beetle for "exoticism," characteristics that contribute to invasive success of Costelytra zealandica (Scarabaeidae: Melolonthinae).

    PubMed

    Lefort, Marie-Caroline; Boyer, Stéphane; Vereijssen, Jessica; Sprague, Rowan; Glare, Travis R; Worner, Susan P

    2015-01-01

    Widespread replacement of native ecosystems by productive land sometimes results in the outbreak of a native species. In New Zealand, the introduction of exotic pastoral plants has resulted in diet alteration of the native coleopteran species, Costelytra zealandica (White) (Scarabaeidae) such that this insect has reached the status of pest. In contrast, C. brunneum (Broun), a congeneric species, has not developed such a relationship with these 'novel' host plants. This study investigated the feeding preferences and fitness performance of these two closely related scarab beetles to increase fundamental knowledge about the mechanisms responsible for the development of invasive characteristics in native insects. To this end, the feeding preference of third instar larvae of both Costelytra species was investigated using an olfactometer device, and the survival and larval growth of the invasive species C. zealandica were compared on native and exotic host plants. Costelytra zealandica, when sampled from exotic pastures, was unable to fully utilise its ancestral native host and showed higher feeding preference and performance on exotic plants. In contrast, C. zealandica sampled from native grasslands did not perform significantly better on either host and showed similar feeding preferences to C. brunneum, which exhibited no feeding preference. This study suggests the possibility of strong intraspecific variation in the ability of C. zealandica to exploit native or exotic plants, supporting the hypothesis that such ability underpins the existence of distinct host-races in this species. PMID:26644985

  3. Dietary Flexibility Aids Asian Earthworm Invasion in North American Forests

    EPA Science Inventory

    On a local scale, invasiveness of introduced species and invasibility of habitats together determine invasion success. A key issue in invasion ecology has been how to quantify the contribution of species invasiveness and habitat invasibility separately. Conventional approaches, s...

  4. The Wide Potential Trophic Niche of the Asiatic Fruit Fly Drosophila suzukii: The Key of Its Invasion Success in Temperate Europe?

    PubMed

    Poyet, Mathilde; Le Roux, Vincent; Gibert, Patricia; Meirland, Antoine; Prévost, Geneviève; Eslin, Patrice; Chabrerie, Olivier

    2015-01-01

    The Asiatic fruit fly Drosophila suzukii has recently invaded Europe and North and South America, causing severe damage to fruit production systems. Although agronomic host plants of that fly are now well documented, little is known about the suitability of wild and ornamental hosts in its exotic area. In order to study the potential trophic niche of D. suzukii with relation to fruit characteristics, fleshy fruits from 67 plant species were sampled in natural and anthropic ecosystems (forests, hedgerows, grasslands, coastal areas, gardens and urban areas) of the north of France and submitted to experimental infestations. A set of fruit traits (structure, colour, shape, skin texture, diameter and weight, phenology) potentially interacting with oviposition choices and development success of D. suzukii was measured. Almost half of the tested plant species belonging to 17 plant families allowed the full development of D. suzukii. This suggests that the extreme polyphagy of the fly and the very large reservoir of hosts producing fruits all year round ensure temporal continuity in resource availability and contribute to the persistence and the exceptional invasion success of D. suzukii in natural habitats and neighbouring cultivated systems. Nevertheless, this very plastic trophic niche is not systematically beneficial to the fly. Some of the tested plants attractive to D. suzukii gravid females stimulate oviposition but do not allow full larval development. Planted near sensitive crops, these "trap plants" may attract and lure D. suzukii, therefore contributing to the control of the invasive fly. PMID:26581101

  5. The Wide Potential Trophic Niche of the Asiatic Fruit Fly Drosophila suzukii: The Key of Its Invasion Success in Temperate Europe?

    PubMed Central

    Poyet, Mathilde; Le Roux, Vincent; Gibert, Patricia; Meirland, Antoine; Prévost, Geneviève; Eslin, Patrice; Chabrerie, Olivier

    2015-01-01

    The Asiatic fruit fly Drosophila suzukii has recently invaded Europe and North and South America, causing severe damage to fruit production systems. Although agronomic host plants of that fly are now well documented, little is known about the suitability of wild and ornamental hosts in its exotic area. In order to study the potential trophic niche of D. suzukii with relation to fruit characteristics, fleshy fruits from 67 plant species were sampled in natural and anthropic ecosystems (forests, hedgerows, grasslands, coastal areas, gardens and urban areas) of the north of France and submitted to experimental infestations. A set of fruit traits (structure, colour, shape, skin texture, diameter and weight, phenology) potentially interacting with oviposition choices and development success of D. suzukii was measured. Almost half of the tested plant species belonging to 17 plant families allowed the full development of D. suzukii. This suggests that the extreme polyphagy of the fly and the very large reservoir of hosts producing fruits all year round ensure temporal continuity in resource availability and contribute to the persistence and the exceptional invasion success of D. suzukii in natural habitats and neighbouring cultivated systems. Nevertheless, this very plastic trophic niche is not systematically beneficial to the fly. Some of the tested plants attractive to D. suzukii gravid females stimulate oviposition but do not allow full larval development. Planted near sensitive crops, these “trap plants” may attract and lure D. suzukii, therefore contributing to the control of the invasive fly. PMID:26581101

  6. Intermittent daytime mouthpiece ventilation successfully augments nocturnal non-invasive ventilation, controlling ventilatory failure and maintaining patient independence.

    PubMed

    Ward, Karen; Ford, Verity; Ashcroft, Helen; Parker, Robert

    2015-01-01

    A 53-year-old woman with spinal muscular atrophy and a 7-year history of nocturnal non-invasive ventilation (NIV) use via nasal mask and chinstrap was admitted electively. Outpatient review suggested symptomatic hypercapnia and hypoxaemia. Use of her usual NIV resulted in early morning respiratory acidosis due to excess mouth leak, and continuous face mask NIV was instigated while in hospital. Once stabilised, she elected to return to nasal ventilation. At outpatient review, respiratory acidosis reoccurred despite diurnal use of NIV. Using the patient's routine ventilator and a novel mouthpiece and trigger algorithm, intermittent daytime mouthpiece ventilation (MPV) was introduced alongside overnight NIV. Control of respiratory failure was achieved and, vitally, independent living maintained. Intermittent MPV was practicable and effective where the limits of ventilator tolerance had otherwise been reached. MPV may reduce the need for tracheostomy ventilation and this case serves as a reminder of the increasing options routinely available to NIV clinicians. PMID:26160549

  7. Evaluation of minimally invasive indices for predicting ascites susceptibility in three successive hatches of broilers exposed to cool temperatures.

    PubMed

    Wideman, R F; Wing, T; Kirby, Y K; Forman, M F; Marson, N; Tackett, C D; Ruiz-Feria, C A

    1998-10-01

    Broilers from three consecutive hatches were exposed to cool temperatures to amplify the incidence of pulmonary hypertension syndrome (PHS, ascites). The largest apparently healthy individuals on Day 42 were evaluated using minimally invasive diagnostic indices [percentage saturation of hemoglobin with oxygen, hematocrit (HCT), heart rate, electrocardiogram (ECG) Lead II, body weight), then they were subjected to the ongoing pressures of fast growth and cool temperatures to determine which of these indices are predictive of the subsequent onset of PHS. Approximately 20% of the males and females evaluated on Day 42 subsequently developed PHS by Day 51. When data for all hatches were pooled and broilers that subsequently developed ascites were compared with those that did not (nonascitic), body weights, heart rates, and percentage saturation of hemoglobin with oxygen were lower on Day 42 for ascitic than for nonascitic males, and HCT was higher in ascitic males and females than in nonascitic males and females, respectively. Comparisons of the ECG Lead II wave amplitudes for all hatches pooled indicated that RS-wave amplitude was larger in ascitic than in nonascitic males, and that S-wave amplitude was more negative in ascitic males and females than in nonascitic males and females. Necropsies conducted on Day 51 revealed higher right:total ventricular weight ratios in ascitic than in nonascitic broilers, whereas normalizing the left ventricle plus septum weight for differences in body weight generated similar values for ascitic and nonascitic males and females, respectively. These results support a primary role for pulmonary hypertension but not cardiomyopathy in the pathogenesis of ascites triggered by cool temperatures. Values obtained for minimally invasive diagnostic indices on Day 42 also establish predictive thresholds that can be used to evaluate the PHS susceptibility of large and apparently healthy male and female broilers.

  8. Recovery of Physiological Traits in Saplings of Invasive Bischofia Tree Compared with Three Species Native to the Bonin Islands under Successive Drought and Irrigation Cycles.

    PubMed

    Yazaki, Kenichi; Kuroda, Katsushi; Nakano, Takashi; Kitao, Mitsutoshi; Tobita, Hiroyuki; Ogasa, Mayumi Y; Ishida, Atsushi

    2015-01-01

    Partial leaf shedding induced by hydraulic failure under prolonged drought can prevent excess water consumption, resulting in delayed recovery of carbon productivity following rainfall. To understand the manner of water use of invasive species in oceanic island forests under a fluctuating water regime, leaf shedding, multiple physiological traits, and the progress of embolism in the stem xylem under repeated drought-irrigation cycles were examined in the potted saplings of an invasive species, Bischofia javanica Blume, and three endemic native species, Schima mertensiana (Sieb. Et Zucc,) Koitz., Hibiscus glaber Matsum, and Distylium lepidotum Nakai, from the Bonin Islands, Japan. The progress of xylem embolism was observed by cryo-scanning electron microscopy. The samples exhibited different processes of water saving and drought tolerance based on the different combinations of partial leaf shedding involved in embolized conduits following repeated de-rehydration. Predawn leaf water potential largely decreased with each successive drought-irrigation cycle for all tree species, except for B. javanica. B. javanica shed leaves conspicuously under drought and showed responsive stomatal conductance to VPD, which contributed to recover leaf gas exchange in the remaining leaves, following a restored water supply. In contrast, native tree species did not completely recover photosynthetic rates during the repeated drought-irrigation cycles. H. glaber and D. lepidotum preserved water in vessels and adjusted leaf osmotic rates but did not actively shed leaves. S. mertensiana exhibited partial leaf shedding during the first cycle with an osmotic adjustment, but they showed less responsive stomatal conductance to VPD. Our data indicate that invasive B. javanica saplings can effectively use water supplied suddenly under drought conditions. We predict that fluctuating precipitation in the future may change tree distributions even in mesic or moist sites in the Bonin Islands.

  9. Recovery of Physiological Traits in Saplings of Invasive Bischofia Tree Compared with Three Species Native to the Bonin Islands under Successive Drought and Irrigation Cycles

    PubMed Central

    Yazaki, Kenichi; Kuroda, Katsushi; Nakano, Takashi; Kitao, Mitsutoshi; Tobita, Hiroyuki; Ogasa, Mayumi Y.; Ishida, Atsushi

    2015-01-01

    Partial leaf shedding induced by hydraulic failure under prolonged drought can prevent excess water consumption, resulting in delayed recovery of carbon productivity following rainfall. To understand the manner of water use of invasive species in oceanic island forests under a fluctuating water regime, leaf shedding, multiple physiological traits, and the progress of embolism in the stem xylem under repeated drought-irrigation cycles were examined in the potted saplings of an invasive species, Bischofia javanica Blume, and three endemic native species, Schima mertensiana (Sieb. Et Zucc,) Koitz., Hibiscus glaber Matsum, and Distylium lepidotum Nakai, from the Bonin Islands, Japan. The progress of xylem embolism was observed by cryo-scanning electron microscopy. The samples exhibited different processes of water saving and drought tolerance based on the different combinations of partial leaf shedding involved in embolized conduits following repeated de-rehydration. Predawn leaf water potential largely decreased with each successive drought-irrigation cycle for all tree species, except for B. javanica. B. javanica shed leaves conspicuously under drought and showed responsive stomatal conductance to VPD, which contributed to recover leaf gas exchange in the remaining leaves, following a restored water supply. In contrast, native tree species did not completely recover photosynthetic rates during the repeated drought-irrigation cycles. H. glaber and D. lepidotum preserved water in vessels and adjusted leaf osmotic rates but did not actively shed leaves. S. mertensiana exhibited partial leaf shedding during the first cycle with an osmotic adjustment, but they showed less responsive stomatal conductance to VPD. Our data indicate that invasive B. javanica saplings can effectively use water supplied suddenly under drought conditions. We predict that fluctuating precipitation in the future may change tree distributions even in mesic or moist sites in the Bonin Islands. PMID

  10. Variability in the Contribution of Different Life Stages to Population Growth as a Key Factor in the Invasion Success of Pinus strobus

    PubMed Central

    Münzbergová, Zuzana; Hadincová, Věra; Wild, Jan; Kindlmannová, Jana

    2013-01-01

    Background Despite the increasing number of studies attempting to model population growth in various organisms, we still know relatively little about the population dynamics of long-lived species that reproduce only in the later stages of their life cycle, such as trees. Predictions of the dynamics of these species are, however, urgently needed for planning management actions when species are either endangered or invasive. In long-lived species, a single management intervention may have consequences for several decades, and detailed knowledge of long-term performance can therefore elucidate possible outcomes during the management planning phase. Methodology and Principal Findings We studied the population dynamics of an invasive tree species, Pinus strobus, in three habitat types represented by their position along the elevation gradient occupied by the species. In agreement with previous studies on the population dynamics of long-lived perennials, our results show that the survival of the largest trees exhibits the highest elasticity in all of the studied habitats. In contrast, life table response experiments (LTRE) analysis showed that different stages contribute the most to population growth rates in different habitats, with generative reproduction being more important in lower slopes and valley bottoms and survival being more important on rock tops and upper slopes. Conclusions The results indicate that P. strobus exhibits different growth strategies in different habitats that result in similar population growth rates. We propose that this plasticity in growth strategies is a key factor in the invasion success of the white pine. In all of the investigated habitats, the population growth rates are above 1, indicating that the population of the species is still increasing and has the ability to spread and occupy a wide range of habitats. PMID:23468896

  11. Recovery of Physiological Traits in Saplings of Invasive Bischofia Tree Compared with Three Species Native to the Bonin Islands under Successive Drought and Irrigation Cycles.

    PubMed

    Yazaki, Kenichi; Kuroda, Katsushi; Nakano, Takashi; Kitao, Mitsutoshi; Tobita, Hiroyuki; Ogasa, Mayumi Y; Ishida, Atsushi

    2015-01-01

    Partial leaf shedding induced by hydraulic failure under prolonged drought can prevent excess water consumption, resulting in delayed recovery of carbon productivity following rainfall. To understand the manner of water use of invasive species in oceanic island forests under a fluctuating water regime, leaf shedding, multiple physiological traits, and the progress of embolism in the stem xylem under repeated drought-irrigation cycles were examined in the potted saplings of an invasive species, Bischofia javanica Blume, and three endemic native species, Schima mertensiana (Sieb. Et Zucc,) Koitz., Hibiscus glaber Matsum, and Distylium lepidotum Nakai, from the Bonin Islands, Japan. The progress of xylem embolism was observed by cryo-scanning electron microscopy. The samples exhibited different processes of water saving and drought tolerance based on the different combinations of partial leaf shedding involved in embolized conduits following repeated de-rehydration. Predawn leaf water potential largely decreased with each successive drought-irrigation cycle for all tree species, except for B. javanica. B. javanica shed leaves conspicuously under drought and showed responsive stomatal conductance to VPD, which contributed to recover leaf gas exchange in the remaining leaves, following a restored water supply. In contrast, native tree species did not completely recover photosynthetic rates during the repeated drought-irrigation cycles. H. glaber and D. lepidotum preserved water in vessels and adjusted leaf osmotic rates but did not actively shed leaves. S. mertensiana exhibited partial leaf shedding during the first cycle with an osmotic adjustment, but they showed less responsive stomatal conductance to VPD. Our data indicate that invasive B. javanica saplings can effectively use water supplied suddenly under drought conditions. We predict that fluctuating precipitation in the future may change tree distributions even in mesic or moist sites in the Bonin Islands. PMID

  12. [Invasive thymoma successfully treated with high-dose chemotherapy followed by peripheral blood stem cell transplantation(PBSCT)].

    PubMed

    Iwasaki, Y; Kubota, Y; Yokomura, I; Ueda, M; Hashimoto, S; Arimoto, T; Inaba, T; Shimazaki, C; Nakagawa, M; Toda, S

    1998-03-01

    A 42-year-old man was admitted with chest pain. A large mass in the anterior mediastinum was seen on a chest X-ray film and confirmed by CT. Surgery was performed, but the tumor was nonresectable because it had invaded the aorta and pulmonary artery, and had disseminated to the pericardium. Invasive thymoma (stage IVa) was diagnosed He initially received two courses of ADOC (50 mg/m2 of cisplatin, 40 mg/m2 of doxorubicin, 0.6 mg/m2 of vincristine, and 700 mg/m2 of cyclophosphamide) at 3-week intervals. Four weeks after the 2 causes of ADOC, he was given 300 mg/m2 of etoposide for five days followed by G-CSF subcutaneously for peripheral blood stem cell collection. After the two courses of ADOC, he received high-dose ICE (1.5 g/m2 of ifosfamide for four days, 400 mg/m2 of carboplatin for three days, and 200 mg/m2 of etoposide for five days) followed by peripheral blood stem cell transplantation (PBSCT). He was given G-CSF after PBSCT, with subsequent rapid neutrophil and platelet recovery. The tumor diminished remarkably in size and complete remission was confirmed pathologically at subsequent thoractomy. Postoperatively, 50 Gy of irradiation was given. These observations suggest that high-dose ICE followed by PBSCT in combination with an ADOC regimen, surgery, and radiotherapy is highly effective and well tolerated in patients with advanced nonresectable thymoma.

  13. The Relative Importance of Genetic Diversity and Phenotypic Plasticity in Determining Invasion Success of a Clonal Weed in the USA and China.

    PubMed

    Geng, Yupeng; van Klinken, Rieks D; Sosa, Alejandro; Li, Bo; Chen, Jiakuan; Xu, Cheng-Yuan

    2016-01-01

    Phenotypic plasticity has been proposed as an important adaptive strategy for clonal plants in heterogeneous habitats. Increased phenotypic plasticity can be especially beneficial for invasive clonal plants, allowing them to colonize new environments even when genetic diversity is low. However, the relative importance of genetic diversity and phenotypic plasticity for invasion success remains largely unknown. Here, we performed molecular marker analyses and a common garden experiment to investigate the genetic diversity and phenotypic plasticity of the globally important weed Alternanthera philoxeroides in response to different water availability (terrestrial vs. aquatic habitats). This species relies predominantly on clonal propagation in introduced ranges. We therefore expected genetic diversity to be restricted in the two sampled introduced ranges (the USA and China) when compared to the native range (Argentina), but that phenotypic plasticity may allow the species' full niche range to nonetheless be exploited. We found clones from China had very low genetic diversity in terms of both marker diversity and quantitative variation when compared with those from the USA and Argentina, probably reflecting different introduction histories. In contrast, similar patterns of phenotypic plasticity were found for clones from all three regions. Furthermore, despite the different levels of genetic diversity, bioclimatic modeling suggested that the full potential bioclimatic distribution had been invaded in both China and USA. Phenotypic plasticity, not genetic diversity, was therefore critical in allowing A. philoxeroides to invade diverse habitats across broad geographic areas.

  14. The Relative Importance of Genetic Diversity and Phenotypic Plasticity in Determining Invasion Success of a Clonal Weed in the USA and China

    PubMed Central

    Geng, Yupeng; van Klinken, Rieks D.; Sosa, Alejandro; Li, Bo; Chen, Jiakuan; Xu, Cheng-Yuan

    2016-01-01

    Phenotypic plasticity has been proposed as an important adaptive strategy for clonal plants in heterogeneous habitats. Increased phenotypic plasticity can be especially beneficial for invasive clonal plants, allowing them to colonize new environments even when genetic diversity is low. However, the relative importance of genetic diversity and phenotypic plasticity for invasion success remains largely unknown. Here, we performed molecular marker analyses and a common garden experiment to investigate the genetic diversity and phenotypic plasticity of the globally important weed Alternanthera philoxeroides in response to different water availability (terrestrial vs. aquatic habitats). This species relies predominantly on clonal propagation in introduced ranges. We therefore expected genetic diversity to be restricted in the two sampled introduced ranges (the USA and China) when compared to the native range (Argentina), but that phenotypic plasticity may allow the species' full niche range to nonetheless be exploited. We found clones from China had very low genetic diversity in terms of both marker diversity and quantitative variation when compared with those from the USA and Argentina, probably reflecting different introduction histories. In contrast, similar patterns of phenotypic plasticity were found for clones from all three regions. Furthermore, despite the different levels of genetic diversity, bioclimatic modeling suggested that the full potential bioclimatic distribution had been invaded in both China and USA. Phenotypic plasticity, not genetic diversity, was therefore critical in allowing A. philoxeroides to invade diverse habitats across broad geographic areas. PMID:26941769

  15. The Relative Importance of Genetic Diversity and Phenotypic Plasticity in Determining Invasion Success of a Clonal Weed in the USA and China.

    PubMed

    Geng, Yupeng; van Klinken, Rieks D; Sosa, Alejandro; Li, Bo; Chen, Jiakuan; Xu, Cheng-Yuan

    2016-01-01

    Phenotypic plasticity has been proposed as an important adaptive strategy for clonal plants in heterogeneous habitats. Increased phenotypic plasticity can be especially beneficial for invasive clonal plants, allowing them to colonize new environments even when genetic diversity is low. However, the relative importance of genetic diversity and phenotypic plasticity for invasion success remains largely unknown. Here, we performed molecular marker analyses and a common garden experiment to investigate the genetic diversity and phenotypic plasticity of the globally important weed Alternanthera philoxeroides in response to different water availability (terrestrial vs. aquatic habitats). This species relies predominantly on clonal propagation in introduced ranges. We therefore expected genetic diversity to be restricted in the two sampled introduced ranges (the USA and China) when compared to the native range (Argentina), but that phenotypic plasticity may allow the species' full niche range to nonetheless be exploited. We found clones from China had very low genetic diversity in terms of both marker diversity and quantitative variation when compared with those from the USA and Argentina, probably reflecting different introduction histories. In contrast, similar patterns of phenotypic plasticity were found for clones from all three regions. Furthermore, despite the different levels of genetic diversity, bioclimatic modeling suggested that the full potential bioclimatic distribution had been invaded in both China and USA. Phenotypic plasticity, not genetic diversity, was therefore critical in allowing A. philoxeroides to invade diverse habitats across broad geographic areas. PMID:26941769

  16. Successful intestinal Echinococcus multilocularis oncosphere invasion and subsequent hepatic metacestode establishment in resistant RccHan™:WIST rats after pharmacological immunosuppression.

    PubMed

    Armua-Fernandez, Maria Teresa; Joekel, Deborah; Schweiger, Alexander; Eichenberger, Ramon Marc; Matsumoto, Jun; Deplazes, Peter

    2016-09-01

    Susceptibility/resistance to larval Echinococcus multilocularis infection varies greatly depending on host species and strains. Whereas several mice strains and non-human primates are highly susceptible to alveolar echinococcosis, rats and most of humans are considered as more resistant. In this study, we aimed to elucidate factors responsible for host resistance in rats (Experiments A-D). (A) The parasite establishment was not observed in immunocompetent Wistar rats orally inoculated with sodium hypochlorite resistant eggs with/without pig bile, or activated/non-activated oncospheres (NAO). Peritoneal inoculation with NAO or metacestode tissue allowed the parasite establishment in rats. (B) T-cell-deficient athymic nude rats showed complete resistance against the metacestode establishment after oral inoculation with parasite eggs. This finding suggests that T-cell-independent parasite clearance occurred in the animals during early phase of the parasite invasion. Finally, Wistar rats that received pharmacological immunosuppression using either dexamethasone (DMS) alone or methotrexate (MTX) i.p. alone or a combination of these compounds were orally inoculated with the parasite's eggs. As a result (D), successful establishment of metacestode with protoscoleces was observed in all 3 rats treated with DMS (s.c.) alone or in all 6 rats treated with DMS (s.c.) plus MTX but not in 8 rats with MTX alone, suggesting that factors affected by DMS treatment are responsible to regulate the parasite invasion and establishment. PMID:27188839

  17. Dynamics of an experimental microbial invasion.

    PubMed

    Acosta, Francisco; Zamor, Richard M; Najar, Fares Z; Roe, Bruce A; Hambright, K David

    2015-09-15

    The ecological dynamics underlying species invasions have been a major focus of research in macroorganisms for the last five decades. However, we still know little about the processes behind invasion by unicellular organisms. To expand our knowledge of microbial invasions, we studied the roles of propagule pressure, nutrient supply, and biotic resistance in the invasion success of a freshwater invasive alga, Prymnesium parvum, using microcosms containing natural freshwater microbial assemblages. Microcosms were subjected to a factorial design with two levels of nutrient-induced diversity and three levels of propagule pressure, and incubated for 7 d, during which P. parvum densities and microbial community composition were tracked. Successful invasion occurred in microcosms receiving high propagule pressure whereas nutrients or community diversity played no role in invasion success. Invaded communities experienced distinctive changes in composition compared with communities where the invasion was unsuccessful. Successfully invaded microbial communities had an increased abundance of fungi and ciliates, and decreased abundances of diatoms and cercozoans. Many of these changes mirrored the microbial community changes detected during a natural P. parvum bloom in the source system. This role of propagule pressure is particularly relevant for P. parvum in the reservoir-dominated southern United States because this species can form large, sustained blooms that can generate intense propagule pressures for downstream sites. Human impact and global climate change are currently causing widespread environmental changes in most southern US freshwater systems that may facilitate P. parvum establishment and, when coupled with strong propagule pressure, could put many more systems at risk for invasion. PMID:26324928

  18. Dynamics of an experimental microbial invasion

    PubMed Central

    Acosta, Francisco; Zamor, Richard M.; Najar, Fares Z.; Roe, Bruce A.; Hambright, K. David

    2015-01-01

    The ecological dynamics underlying species invasions have been a major focus of research in macroorganisms for the last five decades. However, we still know little about the processes behind invasion by unicellular organisms. To expand our knowledge of microbial invasions, we studied the roles of propagule pressure, nutrient supply, and biotic resistance in the invasion success of a freshwater invasive alga, Prymnesium parvum, using microcosms containing natural freshwater microbial assemblages. Microcosms were subjected to a factorial design with two levels of nutrient-induced diversity and three levels of propagule pressure, and incubated for 7 d, during which P. parvum densities and microbial community composition were tracked. Successful invasion occurred in microcosms receiving high propagule pressure whereas nutrients or community diversity played no role in invasion success. Invaded communities experienced distinctive changes in composition compared with communities where the invasion was unsuccessful. Successfully invaded microbial communities had an increased abundance of fungi and ciliates, and decreased abundances of diatoms and cercozoans. Many of these changes mirrored the microbial community changes detected during a natural P. parvum bloom in the source system. This role of propagule pressure is particularly relevant for P. parvum in the reservoir-dominated southern United States because this species can form large, sustained blooms that can generate intense propagule pressures for downstream sites. Human impact and global climate change are currently causing widespread environmental changes in most southern US freshwater systems that may facilitate P. parvum establishment and, when coupled with strong propagule pressure, could put many more systems at risk for invasion. PMID:26324928

  19. The Long-Term Effects of Reduced Competitive Ability on Foraging Success of an Invasive Pest Species.

    PubMed

    Westermann, Fabian Ludwig; Bell, Vaughn Antony; Suckling, David Maxwell; Lester, Philip John

    2016-08-01

    Ant species like Pheidole megacephala (F.), Solenopsis invicta (Buren), and the Argentine ant, Linepithema humile (Mayr), have repeatedly been reported to be strongly associated with honeydew-producing arthropods like aphids, scale insects, and mealybugs, effectively protecting them from biological control agents like parasitoids. Here we report the results of a successful trial using pheromone dispensers to suppress Argentine ant activity over large sections in a commercial vineyard over a period of two months and preventing ant access into and foraging within the vine canopy. We found Argentine ant activity to be significantly reduced in pheromone-treated plots for the duration of the trial period compared with control plots. Our results showed a significant reduction in the numbers of Argentine ant workers recruited to randomly placed food resources within treated plots compared with untreated plots. Furthermore, spatial distribution of Argentine ants alongside transects in untreated plots remained relatively continuous, while increasing sharply beyond the borders of treated plots. Lastly, we measured the body fat content of workers and found a significant reduction in fat among workers from treated plots compared with untreated plots, suggesting an adverse effects on nest fitness. Additionally, we provide an initial assessment of the feasibility of the presented approach. Our results showed that it is possible to control Argentine ant, preventing them access to and foraging within the vine canopy, thereby reducing Argentine ants' access to honeydew.

  20. The Long-Term Effects of Reduced Competitive Ability on Foraging Success of an Invasive Pest Species.

    PubMed

    Westermann, Fabian Ludwig; Bell, Vaughn Antony; Suckling, David Maxwell; Lester, Philip John

    2016-08-01

    Ant species like Pheidole megacephala (F.), Solenopsis invicta (Buren), and the Argentine ant, Linepithema humile (Mayr), have repeatedly been reported to be strongly associated with honeydew-producing arthropods like aphids, scale insects, and mealybugs, effectively protecting them from biological control agents like parasitoids. Here we report the results of a successful trial using pheromone dispensers to suppress Argentine ant activity over large sections in a commercial vineyard over a period of two months and preventing ant access into and foraging within the vine canopy. We found Argentine ant activity to be significantly reduced in pheromone-treated plots for the duration of the trial period compared with control plots. Our results showed a significant reduction in the numbers of Argentine ant workers recruited to randomly placed food resources within treated plots compared with untreated plots. Furthermore, spatial distribution of Argentine ants alongside transects in untreated plots remained relatively continuous, while increasing sharply beyond the borders of treated plots. Lastly, we measured the body fat content of workers and found a significant reduction in fat among workers from treated plots compared with untreated plots, suggesting an adverse effects on nest fitness. Additionally, we provide an initial assessment of the feasibility of the presented approach. Our results showed that it is possible to control Argentine ant, preventing them access to and foraging within the vine canopy, thereby reducing Argentine ants' access to honeydew. PMID:27329630

  1. Parasites and genetic diversity in an invasive bumblebee

    PubMed Central

    Jones, Catherine M; Brown, Mark J F; Ings, Thomas

    2014-01-01

    Biological invasions are facilitated by the global transportation of species and climate change. Given that invasions may cause ecological and economic damage and pose a major threat to biodiversity, understanding the mechanisms behind invasion success is essential. Both the release of non-native populations from natural enemies, such as parasites, and the genetic diversity of these populations may play key roles in their invasion success. We investigated the roles of parasite communities, through enemy release and parasite acquisition, and genetic diversity in the invasion success of the non-native bumblebee, Bombus hypnorum, in the United Kingdom. The invasive B. hypnorum had higher parasite prevalence than most, or all native congeners for two high-impact parasites, probably due to higher susceptibility and parasite acquisition. Consequently parasites had a higher impact on B. hypnorum queens’ survival and colony-founding success than on native species. Bombus hypnorum also had lower functional genetic diversity at the sex-determining locus than native species. Higher parasite prevalence and lower genetic diversity have not prevented the rapid invasion of the United Kingdom by B. hypnorum. These data may inform our understanding of similar invasions by commercial bumblebees around the world. This study suggests that concerns about parasite impacts on the small founding populations common to re-introduction and translocation programs may be less important than currently believed. PMID:24749545

  2. A successful case of biological invasion: the fish Cichla piquiti, an Amazonian species introduced into the Pantanal, Brazil.

    PubMed

    Resende, E K; Marques, D K S; Ferreira, L K S G

    2008-11-01

    The 'tucunaré', Cichla piquiti, an exotic Amazonian fish has become established along the left bank of the Paraguay River in the Pantanal. It was introduced by escaping from culture ponds in the Upper Piquiri River and spread downstream, along the lateral flooded areas of that river, continuing through the clear waters of the left bank of the Paraguay River and reaching south as far as the Paraguai Mirim and Negrinho rivers. Adult spawners have been found in the region, meaning that it is a self-sustained population. Reproduction occurs in the period of low waters. They were found feeding on fishes of lentic environments belonging to the families Characidae, Cichlidae and Loricariidae. Until the end of 2004, its distribution was restricted to the left bank of the Paraguay River, but in March 2005, some specimens were found on the right bank, raising a question for the future: what will be the distribution area of the tucunaré in the Pantanal? Information about its dispersion is increasing: it is known to be in the Tuiuiú Lake, Pantanal National Park and in the Bolivian Pantanal, all of them on the right bank of the Paraguay River. The hypothesis that the 'tucunaré' could not cross turbid waters, such as in the Paraguay River, was refuted by these recent findings. Possibly, the tucunaré's capacity to lay more than one batch of eggs in a reproductive period, as well as its care of eggs and young, lead them to establish themselves successfully in new environments, as has been observed in the Pantanal and other localities. PMID:19197497

  3. The role thermal physiology plays in species invasion

    PubMed Central

    Kelley, Amanda L.

    2014-01-01

    The characterization of physiological phenotypes that may play a part in the establishment of non-native species can broaden our understanding about the ecology of species invasion. Here, an assessment was carried out by comparing the responses of invasive and native species to thermal stress. The goal was to identify physiological patterns that facilitate invasion success and to investigate whether these traits are widespread among invasive ectotherms. Four hypotheses were generated and tested using a review of the literature to determine whether they could be supported across taxonomically diverse invasive organisms. The four hypotheses are as follows: (i) broad geographical temperature tolerances (thermal width) confer a higher upper thermal tolerance threshold for invasive rather than native species; (ii) the upper thermal extreme experienced in nature is more highly correlated with upper thermal tolerance threshold for invasive vs. native animals; (iii) protein chaperone expression—a cellular mechanism that underlies an organism's thermal tolerance threshold—is greater in invasive organisms than in native ones; and (iv) acclimation to higher temperatures can promote a greater range of thermal tolerance for invasive compared with native species. Each hypothesis was supported by a meta-analysis of the invasive/thermal physiology literature, providing further evidence that physiology plays a substantial role in the establishment of invasive ectotherms. PMID:27293666

  4. Invasive arthropods.

    PubMed

    Sanders, C J; Mellor, P S; Wilson, A J

    2010-08-01

    Many arthropod species have been transported around the globe and successfully invaded new regions. Invasive arthropods can have severe impacts on animal and human health, agriculture and forestry, and the biodiversity of natural habitats as well as those modified by humans. The economic and environmental effects of invasion can be both direct, through feeding and competition, and indirect, such as the transmission of pathogens. In this paper, the authors consider ten examples that illustrate the main mechanisms of introduction, the characteristics that enable species to rapidly expand their ranges and some of the consequences of their arrival.

  5. An Appreciative Exploration of How Schools Create a Sense of Belonging to Facilitate the Successful Transition to a New School for Pupils Involved in a Managed Move

    ERIC Educational Resources Information Center

    Flitcroft, Deborah; Kelly, Catherine

    2016-01-01

    Much of the current guidance on managed moves focuses on the benefits of the "fresh start" provided. This paper describes an appreciative inquiry to explore how schools in one local authority create a sense of belonging to facilitate a fresh start for pupils involved in a managed move to a new school. Six deputy head teachers with…

  6. Serum metabolomic profiling facilitates the non-invasive identification of metabolic biomarkers associated with the onset and progression of non-small cell lung cancer.

    PubMed

    Puchades-Carrasco, Leonor; Jantus-Lewintre, Eloisa; Pérez-Rambla, Clara; García-García, Francisco; Lucas, Rut; Calabuig, Silvia; Blasco, Ana; Dopazo, Joaquín; Camps, Carlos; Pineda-Lucena, Antonio

    2016-03-15

    Lung cancer (LC) is responsible for most cancer deaths. One of the main factors contributing to the lethality of this disease is the fact that a large proportion of patients are diagnosed at advanced stages when a clinical intervention is unlikely to succeed. In this study, we evaluated the potential of metabolomics by 1H-NMR to facilitate the identification of accurate and reliable biomarkers to support the early diagnosis and prognosis of non-small cell lung cancer (NSCLC).We found that the metabolic profile of NSCLC patients, compared with healthy individuals, is characterized by statistically significant changes in the concentration of 18 metabolites representing different amino acids, organic acids and alcohols, as well as different lipids and molecules involved in lipid metabolism. Furthermore, the analysis of the differences between the metabolic profiles of NSCLC patients at different stages of the disease revealed the existence of 17 metabolites involved in metabolic changes associated with disease progression.Our results underscore the potential of metabolomics profiling to uncover pathophysiological mechanisms that could be useful to objectively discriminate NSCLC patients from healthy individuals, as well as between different stages of the disease. PMID:26883203

  7. Serum metabolomic profiling facilitates the non-invasive identification of metabolic biomarkers associated with the onset and progression of non-small cell lung cancer

    PubMed Central

    Puchades-Carrasco, Leonor; Jantus-Lewintre, Eloisa; Pérez-Rambla, Clara; García-García, Francisco; Lucas, Rut; Calabuig, Silvia; Blasco, Ana; Dopazo, Joaquín; Camps, Carlos; Pineda-Lucena, Antonio

    2016-01-01

    Lung cancer (LC) is responsible for most cancer deaths. One of the main factors contributing to the lethality of this disease is the fact that a large proportion of patients are diagnosed at advanced stages when a clinical intervention is unlikely to succeed. In this study, we evaluated the potential of metabolomics by 1H-NMR to facilitate the identification of accurate and reliable biomarkers to support the early diagnosis and prognosis of non-small cell lung cancer (NSCLC). We found that the metabolic profile of NSCLC patients, compared with healthy individuals, is characterized by statistically significant changes in the concentration of 18 metabolites representing different amino acids, organic acids and alcohols, as well as different lipids and molecules involved in lipid metabolism. Furthermore, the analysis of the differences between the metabolic profiles of NSCLC patients at different stages of the disease revealed the existence of 17 metabolites involved in metabolic changes associated with disease progression. Our results underscore the potential of metabolomics profiling to uncover pathophysiological mechanisms that could be useful to objectively discriminate NSCLC patients from healthy individuals, as well as between different stages of the disease. PMID:26883203

  8. Limb bone loading in swimming turtles: changes in loading facilitate transitions from tubular to flipper-shaped limbs during aquatic invasions.

    PubMed

    Young, Vanessa K Hilliard; Blob, Richard W

    2015-06-01

    Members of several terrestrial vertebrate lineages have returned to nearly exclusive use of aquatic habitats. These transitions were often accompanied by changes in skeletal morphology, such as flattening of limb bone shafts. Such morphological changes might be correlated with the exposure of limb bones to altered loading. Though the environmental forces acting on the skeleton differ substantially between water and land, no empirical data exist to quantify the impact of such differences on the skeleton, either in terms of load magnitude or regime. To test how locomotor loads change between water and land, we compared in vivo strains from femora of turtles (Trachemys scripta) during swimming and terrestrial walking. As expected, strain magnitudes were much lower (by 67.9%) during swimming than during walking. However, the loading regime of the femur also changed between environments: torsional strains are high during walking, but torsion is largely eliminated during swimming. Changes in loading regime between environments may have enabled evolutionary shifts to hydrodynamically advantageous flattened limb bones in highly aquatic species. Although circular cross sections are optimal for resisting torsional loads, the removal of torsion would reduce the advantage of tubular shapes, facilitating the evolution of flattened limbs. PMID:26085496

  9. Limb bone loading in swimming turtles: changes in loading facilitate transitions from tubular to flipper-shaped limbs during aquatic invasions.

    PubMed

    Young, Vanessa K Hilliard; Blob, Richard W

    2015-06-01

    Members of several terrestrial vertebrate lineages have returned to nearly exclusive use of aquatic habitats. These transitions were often accompanied by changes in skeletal morphology, such as flattening of limb bone shafts. Such morphological changes might be correlated with the exposure of limb bones to altered loading. Though the environmental forces acting on the skeleton differ substantially between water and land, no empirical data exist to quantify the impact of such differences on the skeleton, either in terms of load magnitude or regime. To test how locomotor loads change between water and land, we compared in vivo strains from femora of turtles (Trachemys scripta) during swimming and terrestrial walking. As expected, strain magnitudes were much lower (by 67.9%) during swimming than during walking. However, the loading regime of the femur also changed between environments: torsional strains are high during walking, but torsion is largely eliminated during swimming. Changes in loading regime between environments may have enabled evolutionary shifts to hydrodynamically advantageous flattened limb bones in highly aquatic species. Although circular cross sections are optimal for resisting torsional loads, the removal of torsion would reduce the advantage of tubular shapes, facilitating the evolution of flattened limbs.

  10. Inbreeding depression is purged in the invasive insect Harmonia axyridis.

    PubMed

    Facon, Benoît; Hufbauer, Ruth A; Tayeh, Ashraf; Loiseau, Anne; Lombaert, Eric; Vitalis, Renaud; Guillemaud, Thomas; Lundgren, Jonathan G; Estoup, Arnaud

    2011-03-01

    Bottlenecks in population size reduce genetic diversity and increase inbreeding, which can lead to inbreeding depression. It is thus puzzling how introduced species, which typically pass through bottlenecks, become such successful invaders. However, under certain theoretical conditions, bottlenecks of intermediate size can actually purge the alleles that cause inbreeding depression. Although this process has been confirmed in model laboratory systems, it has yet to be observed in natural invasive populations. We evaluate whether such purging could facilitate biological invasions by using the world-wide invasion of the ladybird (or ladybug) Harmonia axyridis. We first show that invasive populations endured a bottleneck of intermediate intensity. We then demonstrate that replicate introduced populations experience almost none of the inbreeding depression suffered by native populations. Thus, rather than posing a barrier to invasion as often assumed, bottlenecks, by purging deleterious alleles, can enable the evolution of invaders that maintain high fitness even when inbred. PMID:21333536

  11. Different Degrees of Plant Invasion Significantly Affect the Richness of the Soil Fungal Community

    PubMed Central

    Si, Chuncan; Liu, Xueyan; Wang, Congyan; Wang, Lei; Dai, Zhicong; Qi, Shanshan; Du, Daolin

    2013-01-01

    Several studies have shown that soil microorganisms play a key role in the success of plant invasion. Thus, ecologists have become increasingly interested in understanding the ecological effects of biological invasion on soil microbial communities given continuing increase in the effects of invasive plants on native ecosystems. This paper aims to provide a relatively complete depiction of the characteristics of soil microbial communities under different degrees of plant invasion. Rhizospheric soils of the notorious invasive plant Wedelia trilobata with different degrees of invasion (uninvaded, low-degree, and high-degree using its coverage in the invaded ecosystems) were collected from five discrete areas in Hainan Province, P. R. China. Soil physicochemical properties and community structure of soil microorganisms were assessed. Low degrees of W. trilobata invasion significantly increased soil pH values whereas high degrees of invasion did not significantly affected soil pH values. Moreover, the degree of W. trilobata invasion exerted significant effects on soil Ca concentration but did not significantly change other indices of soil physicochemical properties. Low and high degrees of W. trilobata invasion increased the richness of the soil fungal community but did not pose obvious effects on the soil bacterial community. W. trilobata invasion also exerted obvious effects on the community structure of soil microorganisms that take part in soil nitrogen cycling. These changes in soil physicochemical properties and community structure of soil microbial communities mediated by different degrees of W. trilobata invasion may present significant functions in further facilitating the invasion process. PMID:24392015

  12. Contributions of temporal segregation, oviposition choice, and non-additive effects of competitors to invasion success of Aedes japonicus (Diptera: Culicidae) in North America

    PubMed Central

    Murrell, Ebony G.; Noden, Bruce H.; Juliano, Steven A.

    2015-01-01

    The mosquito Aedes japonicus (Diptera: Culicidae) has spread rapidly through North America since its introduction in the 1990s. The mechanisms underlying its establishment in container communities occupied by competitors Aedes triseriatus and Aedes albopictus are unclear. Possibilities include (A) temporal separation of A. japonicus from other Aedes, (B) oviposition avoidance by A. japonicus of sites containing heterospecific Aedes larvae, and (C) non-additive competitive effects in assemblages of multiple Aedes. Containers sampled throughout the summer in an oak-hickory forest near Eureka, MO showed peak abundance for A. japonicus occurring significantly earlier in the season than either of the other Aedes species. Despite this, A. japonicus co-occurred with one other Aedes species in 53 % of samples when present, and co-occurred with both other Aedes in 18 % of samples. In a field oviposition experiment, A. japonicus laid significantly more eggs in forest edge containers than in forest interior containers, but did not avoid containers with low or high densities of larvae of A. triseriatus, A. albopictus, or both, compared to containers without larvae. Interspecific competitive effects (measured as decrease in the index of performance, λ′) of A. triseriatus or A. albopictus alone on A. japonicus larvae were not evident at the densities used, but the effect of both Aedes combined was significantly negative and super-additive of effects of individual interspecific competitors. Thus, neither oviposition avoidance of competitors nor non-additive competitive effects contribute to the invasion success of A. japonicus in North America. Distinct seasonal phenology may reduce competitive interactions with resident Aedes. PMID:26101466

  13. Oxygen supplementation facilitating successful prosthetic fitting and rehabilitation of a patient with severe chronic obstructive pulmonary disease following trans-tibial amputation: a case report

    PubMed Central

    2010-01-01

    Introduction Dysvascular amputations are increasingly performed in patients with underlying cardiac and pulmonary disorders. A limb prosthesis is rarely offered to patients with severe chronic obstructive pulmonary disease because of their inability to achieve the high energy expenditure required for prosthetic ambulation. We describe a case of successful prosthetic fitting and rehabilitation of a patient with severe chronic obstructive pulmonary disease with the aid of oxygen supplementation. Case presentation A 67-year-old aboriginal woman with severe chronic obstructive pulmonary disease and hypercapnic respiratory failure underwent right trans-tibial (below the knee) amputation for severe foot gangrene. An aggressive rehabilitation program of conditioning exercises and gait training utilizing oxygen therapy was initiated. She was custom-fitted with a right trans-tibial prosthesis. A rehabilitation program improved her strength, endurance and stump contracture, and she was able to walk for short distances with the prosthesis. The motion analysis studies showed a cadence of 73.5 steps per minute, a velocity of 0.29 meters per second and no difference in right and left step time and step length. Conclusion This case report illustrates that patients with significant severe chronic obstructive pulmonary disease can be successfully fitted with limb prostheses and undergo rehabilitation using supplemental oxygen along with optimization of their underlying comorbidities. Despite the paucity of published information in this area, prosthesis fitting and rehabilitation should be considered in patients who have undergone amputation and have severe chronic obstructive disease. PMID:21176182

  14. Drought-caused delay in nesting of Sonoran Desert birds and its facilitation of parasite- and predator-mediated variation in reproductive success

    USGS Publications Warehouse

    Chris McCreedy,; Van Riper, Charles

    2015-01-01

    As our understanding of climate change has increased, so has our awareness of the impacts of these changes on biotic systems. Climate models are nearly unanimous in their predictions for increased drought frequency in southwestern North America, and delays in nest initiation due to drought may influence nesting success and productivity for many Sonoran Desert bird species. In southeastern California and western Arizona in 2004–2009, we found negative correlations for 13 of 13 species between nest initiation date and rainfall accumulation during the preceding 4-month winter rainy season. Nesting was delayed more than 3 weeks for some species during extreme droughts in 2006 and 2007. During 2004–2009, we found a significant negative effect of nest initiation date on nest survival probability (β̂ = −0.031 ± 0.005 SE, P < 0.001) for the four species of greatest sample size. To investigate the role of nesting delay in nesting success and productivity, in 2010 we conducted a manipulative experiment with Black-tailed Gnatcatchers (Polioptila melanura; BTGN) and Verdins (Auriparus flaviceps; VERD). Following a wet winter, we delayed clutch initiation dates for treatment pairs to match first-egg dates that we observed during droughts in 2006 and 2007. Nest initiation date had a significant negative effect on nest survival of both species (BTGN: β̂ = −1.18 ± 0.27 SE, P < 0.001; VERD: β̂ = −2.33 ± 0.51 SE, P = 0.003). Treatment pairs were unable to overcome the lost period of high productivity in March and early April, and had lower productivity than control pairs over the entire breeding season. As nest predation and Brown-headed Cowbird (Molothrus ater) parasitism were the most common causes of nest failure, we conclude that the impacts of climate change–caused drought on annual reproductive output in the Sonoran Desert will be further compounded by parasitism and predation for Black-tailed Gnatcatchers and by predation for Verdins.

  15. Social personality polymorphism and the spread of invasive species: a model.

    PubMed

    Fogarty, Sean; Cote, Julien; Sih, Andrew

    2011-03-01

    Ecological invasions are a major worldwide problem exacting tremendous economic and ecological costs. Efforts to explain variability in invasion speed and impact by searching for combinations of ecological conditions and species traits associated with invasions have met with mixed success. We use a simulation model that integrates insights from life-history theory, animal personalities, network theory, and spatial ecology to derive a new mechanism for explaining variation in animal invasion success. We show that spread occurs most rapidly when (1) a species includes a mix of life-history or personality types that differ in density-dependent performance and dispersal tendencies, (2) the differences between types are of intermediate magnitude, and (3) patch connections are intermediate in number and widely spread. Within-species polymorphism in phenotype (e.g., life-history strategies or personality), a feature not included in previous models, is important for overcoming the fact that different traits are associated with success in different stages of the invasion process. Polymorphism in sociability (a personality type) increases the speed of the invasion front, since asocial individuals colonize empty patches and facilitate the local growth of social types that, in turn, induce faster dispersal by asocials at the invasion edge. The results hold implications for the prediction of invasion impacts and the classification of traits associated with invasiveness.

  16. Evidence of qualitative differences between soil-occupancy effects of invasive vs. native grassland plant species

    USGS Publications Warehouse

    Jordan, N.R.; Larson, D.L.; Huerd, S.C.

    2011-01-01

    Diversified grasslands that contain native plant species are being recognized as important elements of agricultural landscapes and for production of biofuel feedstocks as well as a variety of other ecosystem services. Unfortunately, establishment of such grasslands is often difficult, unpredictable, and highly vulnerable to interference and invasion by weeds. Evidence suggests that soil-microbial "legacies" of invasive perennial species can inhibit growth of native grassland species. However, previous assessments of legacy effects of soil occupancy by invasive species that invade grasslands have focused on single invasive species and on responses to invasive soil occupancy in only a few species. In this study, we tested the hypothesis that legacy effects of invasive species differ qualitatively from those of native grassland species. In a glasshouse, three invasive and three native grassland perennials and a native perennial mixture were grown separately through three cycles of growth and soil conditioning in soils with and without arbuscular mycorrhizal fungi (AMF), after which we assessed seedling growth in these soils. Native species differed categorically from invasives in their response to soil conditioning by native or invasive species, but these differences depended on the presence of AMF. When AMF were present, native species largely had facilitative effects on invasive species, relative to effects of invasives on other invasives. Invasive species did not facilitate native growth; neutral effects were predominant, but strong soil-mediated inhibitory effects on certain native species occurred. Our results support the hypothesis that successful plant invaders create biological legacies in soil that inhibit native growth, but suggest also this mechanism of invasion will have nuanced effects on community dynamics, as some natives may be unaffected by such legacies. Such native species may be valuable as nurse plants that provide cost-effective restoration of

  17. Evidence of qualitative differences between soil-occupancy effects of invasive vs. native grassland plant species

    USGS Publications Warehouse

    Jordan, Nicholas R.; Larson, Diane L.; Huerd, Sheri C.

    2011-01-01

    Diversified grasslands that contain native plant species are being recognized as important elements of agricultural landscapes and for production of biofuel feedstocks as well as a variety of other ecosystem services. Unfortunately, establishment of such grasslands is often difficult, unpredictable, and highly vulnerable to interference and invasion by weeds. Evidence suggests that soil-microbial "legacies" of invasive perennial species can inhibit growth of native grassland species. However, previous assessments of legacy effects of soil occupancy by invasive species that invade grasslands have focused on single invasive species and on responses to invasive soil occupancy in only a few species. In this study, we tested the hypothesis that legacy effects of invasive species differ qualitatively from those of native grassland species. In a glasshouse, three invasive and three native grassland perennials and a native perennial mixture were grown separately through three cycles of growth and soil conditioning in soils with and without arbuscular mycorrhizal fungi (AMF), after which we assessed seedling growth in these soils. Native species differed categorically from invasives in their response to soil conditioning by native or invasive species, but these differences depended on the presence of AMF. When AMF were present, native species largely had facilitative effects on invasive species, relative to effects of invasives on other invasives. Invasive species did not facilitate native growth; neutral effects were predominant, but strong soil-mediated inhibitory effects on certain native species occurred. Our results support the hypothesis that successful plant invaders create biological legacies in soil that inhibit native growth, but suggest also this mechanism of invasion will have nuanced effects on community dynamics, as some natives may be unaffected by such legacies. Such native species may be valuable as nurse plants that provide cost-effective restoration of

  18. Interactions between ecosystem engineers: A native species indirectly facilitates a non-native one

    NASA Astrophysics Data System (ADS)

    Sueiro, María Cruz; Schwindt, Evangelina; Mendez, María Martha (Pitu); Bortolus, Alejandro

    2013-08-01

    The positive impact that native species have on the survival, persistence and/or range-expansion of invasive species, is receiving increasing attention from ecologists and land managers trying to better understand and predict future invasions worldwide. Ecosystem engineers are among the best-known model organisms for such studies. The austral cordgrass Spartina densiflora is an ecosystem engineer native to South America coast, where it colonizes rocky shores that were recently successfully invaded by the acorn barnacle Balanus glandula. We conducted a field experiment combining living Spartina transplants and artificial model plants in order to address the following questions: Does the native ecosystem engineer S. densiflora facilitate the invasion of rocky shores by B. glandula? If so, how much of this facilitation is caused by its physical structure alone? We found that S. densiflora had a positive effect on the invasive barnacle by trapping among its stems, the mussels, shells and gravels where B. glandula settles. Dislodged mussels, cobbles, and small shells covered and agglutinated by living barnacles were retained within the aboveground structures of S. densiflora while the control plots (without living or artificial plant structures) remained mostly bare throughout the experiment, showing how plant structures speed the colonization process. Moreover, transplanting living Spartina and artificial Spartina models led to a maximum increase in the area covered by barnacles of more than 1700% relative to the unvegetated control plots. Our study clearly shows how a native ecosystem engineers can enhance the success of invasive species and facilitate their local spread.

  19. Establishment and abundance of Tetrastichus planipennisi (Hymenoptera: Eulophidae) in Michigan: potential for success in classical biocontrol of the invasive emerald ash borer (Coleoptera: Buprestidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Tetrastichus planipennisi Yang is a gregarious larval endoparasitoid native to China, and has been introduced to the United States since 2007 for classical biological control of the invasive emerald ash borer (EAB), Agrilus planipennis Fairmaire, an exotic beetle responsible for widespread ash morta...

  20. Using Annual Forbs and Early Seral Species in Seeding Mixtures for Improved Success in Great Basin Restoration

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Use of native annual and early sera! species in Great Basin rangeland reseeding efforts may increase invasion resistance, facilitate succession to desired vegetation, and improve restoration/rehabilitation success. Because they occupy a similar ecological niche, due to functional trait similarities ...

  1. Spatially variable propagule pressure and herbivory influence invasion of chaparral shrubland by an exotic grass.

    PubMed

    Lambrinos, John G

    2006-03-01

    Although numerous studies have identified mechanisms that either resist or facilitate biological invasions, few studies have explicitly tested how resisting and facilitating mechanisms interact to drive invasion success. In California, USA, undisturbed Mediterranean-type shrublands have resisted invasion by the perennial tussock grass Cortaderia jubata. In some cases, however, this resistance has been spectacularly breached even in the absence of large-scale disturbance. I tested the hypothesis that these invasions are facilitated by local reductions in the strength of biotic resistance. I evaluated invasive success using C. jubata seed and seedling additions at different microhabitats: the edge of a chaparral stand, under shrub canopy at different distances from the stand edge, and in canopy gaps within the stand. When left exposed to mammalian herbivores, seedling survivorship decreased sharply from nearly 40% on the stand edge to zero just 10 m into the stand. When transplants were protected from herbivory, however, distance from the edge had no significant influence on transplant survivorship. Seedling emergence was also greater on the edge and in canopy gaps than under the canopy, but these differences were not caused by differences in herbivory. The flux of invasive propagules reaching the soil surface was immense and greater along the edge and within gaps than under the stand canopy. Mirroring these patterns, naturally occurring seedling abundance declined dramatically with distance from the stand edge, and seedlings were far more common within stand gaps than would be expected given gap frequency within the stand. Despite strong biotic resistance to invasion within the stand, the cover of C. jubata has increased 20% over the last 9 years. These results suggest that the relative amount of susceptible edge habitat and the supply of invasive propagules can facilitate invasion even in the face of strong local biotic resistance.

  2. Biological invasions, climate change and genomics.

    PubMed

    Chown, Steven L; Hodgins, Kathryn A; Griffin, Philippa C; Oakeshott, John G; Byrne, Margaret; Hoffmann, Ary A

    2015-01-01

    The rate of biological invasions is expected to increase as the effects of climate change on biological communities become widespread. Climate change enhances habitat disturbance which facilitates the establishment of invasive species, which in turn provides opportunities for hybridization and introgression. These effects influence local biodiversity that can be tracked through genetic and genomic approaches. Metabarcoding and metagenomic approaches provide a way of monitoring some types of communities under climate change for the appearance of invasives. Introgression and hybridization can be followed by the analysis of entire genomes so that rapidly changing areas of the genome are identified and instances of genetic pollution monitored. Genomic markers enable accurate tracking of invasive species' geographic origin well beyond what was previously possible. New genomic tools are promoting fresh insights into classic questions about invading organisms under climate change, such as the role of genetic variation, local adaptation and climate pre-adaptation in successful invasions. These tools are providing managers with often more effective means to identify potential threats, improve surveillance and assess impacts on communities. We provide a framework for the application of genomic techniques within a management context and also indicate some important limitations in what can be achieved.

  3. Biological invasions, climate change and genomics

    PubMed Central

    Chown, Steven L; Hodgins, Kathryn A; Griffin, Philippa C; Oakeshott, John G; Byrne, Margaret; Hoffmann, Ary A

    2015-01-01

    The rate of biological invasions is expected to increase as the effects of climate change on biological communities become widespread. Climate change enhances habitat disturbance which facilitates the establishment of invasive species, which in turn provides opportunities for hybridization and introgression. These effects influence local biodiversity that can be tracked through genetic and genomic approaches. Metabarcoding and metagenomic approaches provide a way of monitoring some types of communities under climate change for the appearance of invasives. Introgression and hybridization can be followed by the analysis of entire genomes so that rapidly changing areas of the genome are identified and instances of genetic pollution monitored. Genomic markers enable accurate tracking of invasive species’ geographic origin well beyond what was previously possible. New genomic tools are promoting fresh insights into classic questions about invading organisms under climate change, such as the role of genetic variation, local adaptation and climate pre-adaptation in successful invasions. These tools are providing managers with often more effective means to identify potential threats, improve surveillance and assess impacts on communities. We provide a framework for the application of genomic techniques within a management context and also indicate some important limitations in what can be achieved. PMID:25667601

  4. The effect of light radiation and temperature variability on the invasion of marine fouling species

    NASA Astrophysics Data System (ADS)

    Kim, T.; Micheli, F.

    2009-12-01

    Climate change can alter the community structure as species which have adapted to the changed climate can compete better with other species. It can also influence the recruitment and invasion success of marine introduced species. Climate change involves not only global warming but also global dimming. However, it was not tested which of warming or dimming factors more significantly influence the invasion of marine species. To test this, we manipulated both temperature variability and light radiation by deploying different shading devices (black, white, transparent, and no treatment) for recruitment tiles in the warmer region where the species invasion rate is high. We compared the species frequency and coverage between shaded and non-shaded treatments. Interestingly, under opaque white plates where light radiation is lower than under transparent plates but the temperature is higher than under black plates, had the highest frequency and coverage of invasive fouling species. The recruitment tiles under black plates got second higher invasion of exotic species. We also deployed recruitment tiles in 14 different sites to determine if temperature influences the success of invasive species. The coverage of invasive species over native species increased significantly with increasing temperature. The results suggest that both low radiation and higher temperature facilitates the success of species invasion in the intertidal region.

  5. Investigating Invasives

    ERIC Educational Resources Information Center

    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…

  6. [A Case of an Unresectable Locally Advanced Rectal Cancer with Surrounding Organ Invasion Successfully Resected after Chemotherapy with mFOLFOX6 plus Cetuximab].

    PubMed

    Takagi, Hironori; Ariake, Kyohei; Takemura, Shinichi; Doi, Takashi

    2016-03-01

    A 63-year-old man visited our hospital with pain on micturition and was found to have a large rectal tumor with urinary bladder invasion on enhanced abdominal computed tomography (CT). The tumor appeared to be unresectable at presentation; thus, sigmoid colostomy was performed and chemotherapy was initiated. The tumor was found to be EGFR-positive and contained a wild-type KRAS. The mFOLFOX6 plus cetuximab (c-mab) regimen was initiated. The follow-up CT scan showed good tumor shrinkage after 4 courses of chemotherapy; 4 additional courses were administered. The tumor eventually regressed by more than 60% and was judged to be resectable. High anterior resection of the rectum with partial resection of the bladder was performed. Abdominal wall metastasis was detected 8 months after surgery, and additional resection was performed. The patient remained well with no other recurrence 8 months after the high anterior resection. Although chemoradiotherapy is the standard preoperative treatment of locally advanced rectal cancer, systemic therapy is effective in certain cases such as substantial tumor invasion of adjacent organs or metastasis. Here, we present a case of rectal cancer that became curatively resectable after preoperative chemotherapy with mFOLFOX6 plus c-mab.

  7. Preference of a native beetle for “exoticism,” characteristics that contribute to invasive success of Costelytra zealandica (Scarabaeidae: Melolonthinae)

    PubMed Central

    Boyer, Stéphane; Vereijssen, Jessica; Sprague, Rowan; Glare, Travis R.; Worner, Susan P.

    2015-01-01

    Widespread replacement of native ecosystems by productive land sometimes results in the outbreak of a native species. In New Zealand, the introduction of exotic pastoral plants has resulted in diet alteration of the native coleopteran species, Costelytra zealandica (White) (Scarabaeidae) such that this insect has reached the status of pest. In contrast, C. brunneum (Broun), a congeneric species, has not developed such a relationship with these ‘novel’ host plants. This study investigated the feeding preferences and fitness performance of these two closely related scarab beetles to increase fundamental knowledge about the mechanisms responsible for the development of invasive characteristics in native insects. To this end, the feeding preference of third instar larvae of both Costelytra species was investigated using an olfactometer device, and the survival and larval growth of the invasive species C. zealandica were compared on native and exotic host plants. Costelytra zealandica, when sampled from exotic pastures, was unable to fully utilise its ancestral native host and showed higher feeding preference and performance on exotic plants. In contrast, C. zealandica sampled from native grasslands did not perform significantly better on either host and showed similar feeding preferences to C. brunneum, which exhibited no feeding preference. This study suggests the possibility of strong intraspecific variation in the ability of C. zealandica to exploit native or exotic plants, supporting the hypothesis that such ability underpins the existence of distinct host-races in this species. PMID:26644985

  8. Parasites and marine invasions

    USGS Publications Warehouse

    Torchin, M.E.; Lafferty, K.D.; Kuris, A.M.

    2002-01-01

    Introduced marine species are a major environmental and economic problem. The rate of these biological invasions has substantially increased in recent years due to the globalization of the world's economies. The damage caused by invasive species is often a result of the higher densities and larger sizes they attain compared to where they are native. A prominent hypothesis explaining the success of introduced species is that they are relatively free of the effects of natural enemies. Most notably, they may encounter fewer parasites in their introduced range compared to their native range. Parasites are ubiquitous and pervasive in marine systems, yet their role in marine invasions is relatively unexplored. Although data on parasites of marine organisms exist, the extent to which parasites can mediate marine invasions, or the extent to which invasive parasites and pathogens are responsible for infecting or potentially decimating native marine species have not been examined. In this review, we present a theoretical framework to model invasion success and examine the evidence for a relationship between parasite presence and the success of introduced marine species. For this, we compare the prevalence and species richness of parasites in several introduced populations of marine species with populations where they are native. We also discuss the potential impacts of introduced marine parasites on native ecosystems.

  9. Does polyploidy facilitate long-distance dispersal?

    PubMed Central

    Linder, H. Peter; Barker, Nigel P.

    2014-01-01

    Background and Aims The ability of plant lineages to reach all continents contributes substantially to their evolutionary success. This is exemplified by the Poaceae, one of the most successful angiosperm families, in which most higher taxa (tribes, subfamilies) have global distributions. Due to the old age of the ocean basins relative to the major angiosperm radiations, this is only possible by means of long-distance dispersal (LDD), yet the attributes of lineages with successful LDD remain obscure. Polyploid species are over-represented in invasive floras and in the previously glaciated Arctic regions, and often have wider ecological tolerances than diploids; thus polyploidy is a candidate attribute of successful LDD. Methods The link between polyploidy and LDD was explored in the globally distributed grass subfamily Danthonioideae. An almost completely sampled and well-resolved species-level phylogeny of the danthonioids was used, and the available cytological information was assembled. The cytological evolution in the clade was inferred using maximum likelihood (ML) as implemented in ChromEvol. The biogeographical evolution in the clade was reconstructed using ML and Bayesian approaches. Key Results Numerous increases in ploidy level are demonstrated. A Late Miocene–Pliocene cycle of polyploidy is associated with LDD, and in two cases (the Australian Rytidosperma and the American Danthonia) led to secondary polyploidy. While it is demonstrated that successful LDD is more likely in polyploid than in diploid lineages, a link between polyploidization events and LDD is not demonstrated. Conclusions The results suggest that polyploids are more successful at LDD than diploids, and that the frequent polyploidy in the grasses might have facilitated the extensive dispersal among continents in the family, thus contributing to their evolutionary success. PMID:24694830

  10. Invasive Candidiasis

    MedlinePlus

    ... Invasive candidiasis is an infection caused by a yeast (a type of fungus) called Candida . Unlike Candida ... mouth and throat (also called “thrush”) or vaginal “yeast infections,” invasive candidiasis is a serious infection that ...

  11. Mycorrhizal co-invasion and novel interactions depend on neighborhood context.

    PubMed

    Moeller, Holly V; Dickie, Ian A; Peltzer, Duane A; Fukami, Tadashi

    2015-09-01

    Biological invasions are a rapidly increasing driver of global change, yet fundamental gaps remain in our understanding of the factors determining the success or extent of invasions. For example, although most woody plant species depend on belowground mutualists such as mycorrhizal fungi and nitrogen-fixing bacteria, the relative importance of these mutualisms in conferring invasion success is unresolved. Here, we describe how neighborhood context (identity of nearby tree species) affects the formation of belowground ectomycorrhizal partnerships between fungi and seedlings of a widespread invasive tree species, Pseudotsuga menziesii (Douglas-fir), in New Zealand. We found that the formation of mycorrhizal partnerships, the composition of the fungal species involved in these partnerships, and the origin of the fungi (co-invading or native to New Zealand) all depend on neighborhood context. Our data suggest that nearby ectomycorrhizal host trees act as both a reservoir of fungal inoculum and a carbon source for late-successional and native fungi. By facilitating mycorrhization of P. menziesii seedlings, adult trees may alleviate mycorrhizal limitation at the P. menziesii invasion front. These results highlight the importance of studying biological invasions across multiple ecological settings to understand establishment success and invasion speed. PMID:26594692

  12. Establishment and abundance of Tetrastichus planipennisi (Hymenoptera: Eulophidae) in Michigan: potential for success in classical biocontrol of the invasive emerald ash borer (Coleoptera: Buprestidae).

    PubMed

    Duan, Jian J; Bauer, Leah S; Abell, Kristopher J; Lelito, Jonathan P; Van Driesche, Roy

    2013-06-01

    Tetrastichus planipennisi Yang is a gregarious larval endoparasitoid native to China and has been introduced to the United States since 2007 for classical biological control of the invasive emerald ash borer, Agrilus planipennis Fairmaire, an exotic beetle responsible for widespread ash mortality. Between 2007-2010, T. planipennisi adults (3,311-4,597 females and approximately 1,500 males per site) were released into each of six forest sites in three counties (Ingham, Gratiot, and Shiawassee) of southern Michigan. By the fall of 2012, the proportion of sampled trees with one or more broods of T. planipennisi increased to 92 and 83% in the parasitoid-release and control plots, respectively, from 33 and 4% in the first year after parasitoid releases (2009 fall for Ingham county sites and 2010 for other sites). Similarly, the mean number of T. planipennisi broods observed from sampled trees increased from less than one brood per tree in the first year after parasitoid releases to 2.46 (at control plots) to 3.08 (at release plots) broods by the fall of 2012. The rates of emerald ash borer larval parasitism by T. planipennisi also increased from 1.2% in the first year after parasitoid releases to 21.2% in the parasitoid-release plots, and from 0.2 to 12.8% for the control plots by the fall of 2012. These results demonstrate that T. planipennisi is established in southern Michigan and that its populations are increasing and expanding. This suggests that T. planipennisi will likely play a critical role in suppressing emerald ash borer populations in Michigan. PMID:23865178

  13. Establishment and abundance of Tetrastichus planipennisi (Hymenoptera: Eulophidae) in Michigan: potential for success in classical biocontrol of the invasive emerald ash borer (Coleoptera: Buprestidae).

    PubMed

    Duan, Jian J; Bauer, Leah S; Abell, Kristopher J; Lelito, Jonathan P; Van Driesche, Roy

    2013-06-01

    Tetrastichus planipennisi Yang is a gregarious larval endoparasitoid native to China and has been introduced to the United States since 2007 for classical biological control of the invasive emerald ash borer, Agrilus planipennis Fairmaire, an exotic beetle responsible for widespread ash mortality. Between 2007-2010, T. planipennisi adults (3,311-4,597 females and approximately 1,500 males per site) were released into each of six forest sites in three counties (Ingham, Gratiot, and Shiawassee) of southern Michigan. By the fall of 2012, the proportion of sampled trees with one or more broods of T. planipennisi increased to 92 and 83% in the parasitoid-release and control plots, respectively, from 33 and 4% in the first year after parasitoid releases (2009 fall for Ingham county sites and 2010 for other sites). Similarly, the mean number of T. planipennisi broods observed from sampled trees increased from less than one brood per tree in the first year after parasitoid releases to 2.46 (at control plots) to 3.08 (at release plots) broods by the fall of 2012. The rates of emerald ash borer larval parasitism by T. planipennisi also increased from 1.2% in the first year after parasitoid releases to 21.2% in the parasitoid-release plots, and from 0.2 to 12.8% for the control plots by the fall of 2012. These results demonstrate that T. planipennisi is established in southern Michigan and that its populations are increasing and expanding. This suggests that T. planipennisi will likely play a critical role in suppressing emerald ash borer populations in Michigan.

  14. Enhanced Invasion of Metastatic Cancer Cells via Extracellular Matrix Interface

    PubMed Central

    Zhu, Jiangrui; Liang, Long; Jiao, Yang; Liu, Liyu

    2015-01-01

    Cancer cell invasion is a major component of metastasis and is responsible for extensive cell diffusion into and major destruction of tissues. Cells exhibit complex invasion modes, including a variety of collective behaviors. This phenomenon results in the structural heterogeneity of the extracellular matrix (ECM) in tissues. Here, we systematically investigated the environmental heterogeneity facilitating tumor cell invasion via a combination of in vitro cell migration experiments and computer simulations. Specifically, we constructed an ECM microenvironment in a microfabricated biochip and successfully created a three-dimensional (3D) funnel-like matrigel interface inside. Scanning electron microscopy demonstrated that the interface was at the interior defects of the nano-scale molecular anisotropic orientation and the localized structural density variations in the matrigel. Our results, particularly the correlation of the collective migration pattern with the geometric features of the funnel-like interface, indicate that this heterogeneous in vitro ECM structure strongly guides and promotes aggressive cell invasion in the rigid matrigel space. A cellular automaton model was proposed based on our experimental observations, and the associated quantitative analysis indicated that cell invasion was initiated and controlled by several mechanisms, including microenvironment heterogeneity, long-range cell-cell homotype and gradient-driven directional cellular migration. Our work shows the feasibility of constructing a complex and heterogeneous in vitro 3D ECM microenvironment that mimics the in vivo environment. Moreover, our results indicate that ECM heterogeneity is essential in controlling collective cell invasive behaviors and therefore determining metastasis efficiency. PMID:25706718

  15. Understanding invasion history and predicting invasive niches using genetic sequencing technology in Australia: case studies from Cucurbitaceae and Boraginaceae

    PubMed Central

    Shaik, Razia S.; Zhu, Xiaocheng; Clements, David R.; Weston, Leslie A.

    2016-01-01

    Part of the challenge in dealing with invasive plant species is that they seldom represent a uniform, static entity. Often, an accurate understanding of the history of plant introduction and knowledge of the real levels of genetic diversity present in species and populations of importance is lacking. Currently, the role of genetic diversity in promoting the successful establishment of invasive plants is not well defined. Genetic profiling of invasive plants should enhance our understanding of the dynamics of colonization in the invaded range. Recent advances in DNA sequencing technology have greatly facilitated the rapid and complete assessment of plant population genetics. Here, we apply our current understanding of the genetics and ecophysiology of plant invasions to recent work on Australian plant invaders from the Cucurbitaceae and Boraginaceae. The Cucurbitaceae study showed that both prickly paddy melon (Cucumis myriocarpus) and camel melon (Citrullus lanatus) were represented by only a single genotype in Australia, implying that each was probably introduced as a single introduction event. In contrast, a third invasive melon, Citrullus colocynthis, possessed a moderate level of genetic diversity in Australia and was potentially introduced to the continent at least twice. The Boraginaceae study demonstrated the value of comparing two similar congeneric species; one, Echium plantagineum, is highly invasive and genetically diverse, whereas the other, Echium vulgare, exhibits less genetic diversity and occupies a more limited ecological niche. Sequence analysis provided precise identification of invasive plant species, as well as information on genetic diversity and phylogeographic history. Improved sequencing technologies will continue to allow greater resolution of genetic relationships among invasive plant populations, thereby potentially improving our ability to predict the impact of these relationships upon future spread and better manage invaders possessing

  16. Dispersal ability and invasion success of Crepidula fornicata in a single gulf: insights from genetic markers and larval-dispersal model

    NASA Astrophysics Data System (ADS)

    Viard, Frédérique; Ellien, Céline; Dupont, Lise

    2006-05-01

    The success of an exotic species relies on many factors including dispersal capabilities and adaptation to novel environments. In particular, rapid spread from an initial point of introduction favours long-term establishment of exotic species, especially when large genetic diversity is maintained during the colonization phase. We here focused on the slipper limpet, Crepidula fornicata, a species native to the western Atlantic that has successfully invaded European bays and estuaries since the end of the nineteenth century following repeated introductions. Its settlement at high densities has major consequences on the macro-benthic fauna and flora. The aim of the present study was to analyse the ability of C. fornicata for rapid diffusion and long-distance dispersal, at the level of a large French gulf, namely the gulf of St-Malo (covering 120 km in latitude and 40 km in longitude) in the English Channel. The genetic architecture of 16 populations distributed all over this gulf was investigated using five microsatellite loci. Genetic diversity was found to be high and did not vary significantly with population density, population age or geographic location. Moreover, despite potential isolation among populations due to a strong tidal regime and the action of wind-induced currents, only weak barriers to gene flow were found across the gulf. These results were in agreement with results obtained from a simple 2D larval dispersal model. Both genetic data and the simulation model highlighted the potential for rapid and efficient spread of C. fornicata at a regional level.

  17. Cheatgrass invasion and wildlife habitat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The introduction and subsequent invasion of cheatgrass (Bromus tectorum) has altered native plant communities and the wildlife species that depend on these communities. Cheatgrass has truncated secondary succession by outcompeting native plant species for limited resources, thus building persistent...

  18. The importance of quantifying propagule pressure to understand invasion: an examination of riparian forest invasibility.

    PubMed

    Eschtruth, Anne K; Battles, John J

    2011-06-01

    The widely held belief that riparian communities are highly invasible to exotic plants is based primarily on comparisons of the extent of invasion in riparian and upland communities. However, because differences in the extent of invasion may simply result from variation in propagule supply among recipient environments, true comparisons of invasibility require that both invasion success and propagule pressure are quantified. In this study, we quantified propagule pressure in order to compare the invasibility of riparian and upland forests and assess the accuracy of using a community's level of invasion as a surrogate for its invasibility. We found the extent of invasion to be a poor proxy for invasibility. The higher level of invasion in the studied riparian forests resulted from greater propagule availability rather than higher invasibility. Furthermore, failure to account for propagule pressure may confound our understanding of general invasion theories. Ecological theory suggests that species-rich communities should be less invasible. However, we found significant relationships between species diversity and invasion extent, but no diversity-invasibility relationship was detected for any species. Our results demonstrate that using a community's level of invasion as a surrogate for its invasibility can confound our understanding of invasibility and its determinants.

  19. The Origin of Invasive Microorganisms Matters for Science, Policy, and Management: The Case of Didymosphenia geminata

    PubMed Central

    Taylor, Brad W.; Bothwell, Max L.

    2014-01-01

    The value of distinguishing native from nonnative invasive species has recently been questioned. However, this dichotomy is important for understanding whether a species’ successful dominance is caused by introductions, changing environmental conditions that facilitate an existing population, or both processes. We highlight the importance of knowing the origin of hard-to-detect invasive microorganisms for scientific research, management, and policy using a case study of recent algal blooms of the stalk-producing diatom Didymosphenia geminata. Nuisance blooms have been reported in rivers worldwide and have been hastily attributed to introductions. However, evidence indicates that blooms are probably not caused by introductions but, rather, by environmental conditions that promote excessive stalk production by this historically rare species. Effective responses to invasive microorganisms depend on knowing whether their proliferation is caused by being nonnative or is the result of changing environmental conditions that promote invasive characteristics of native species. PMID:26955071

  20. Minimally invasive pancreatic surgery.

    PubMed

    Yiannakopoulou, E

    2015-12-01

    Minimally invasive pancreatic surgery is feasible and safe. Laparoscopic distal pancreatectomy should be widely adopted for benign lesions of the pancreas. Laparoscopic pancreaticoduodenectomy, although technically demanding, in the setting of pancreatic ductal adenocarcinoma has a number of advantages including shorter hospital stay, faster recovery, allowing patients to recover in a timelier manner and pursue adjuvant treatment options. Furthermore, it seems that progression-free survival is longer in patients undergoing laparoscopic pancreaticoduodenectomy in comparison with those undergoing open pancreaticoduodenectomy. Minimally invasive middle pancreatectomy seems appropriate for benign or borderline tumors of the neck of the pancreas. Technological advances including intraoperative ultrasound and intraoperative fluorescence imaging systems are expected to facilitate the wide adoption of minimally invasive pancreatic surgery. Although, the oncological outcome seems similar with that of open surgery, there are still concerns, as the majority of relevant evidence comes from retrospective studies. Large multicenter randomized studies comparing laparoscopic with open pancreatectomy as well as robotic assisted with both open and laparoscopic approaches are needed. Robotic approach could be possibly shown to be less invasive than conventional laparoscopic approach through the less traumatic intra-abdominal handling of tissues. In addition, robotic approach could enable the wide adoption of the technique by surgeon who is not that trained in advanced laparoscopic surgery. A putative clinical benefit of minimally invasive pancreatic surgery could be the attenuated surgical stress response leading to reduced morbidity and mortality as well as lack of the detrimental immunosuppressive effect especially for the oncological patients. PMID:26530291

  1. Different responses of invasive and native species to elevated CO 2 concentration

    NASA Astrophysics Data System (ADS)

    Song, Liying; Wu, Jinrong; Li, Changhan; Li, Furong; Peng, Shaolin; Chen, Baoming

    2009-01-01

    Increasing atmospheric CO 2 concentration is regarded as an important factor facilitating invasion. However, the mechanisms by which invasive plants spread at the expense of existing native plants are poorly understood. In this study, three invasive species ( Mikania micrantha, Wedelia trilobata and Ipomoea cairica) and their indigenous co-occurring species or congeners ( Paederia scandens, Wedelia chinensis and Ipomoea pescaprae) in South China were exposed to elevated CO 2 concentration (700 μmol mol -1). The invasive species showed an average increase of 67.1% in photosynthetic rate, significantly different from the native species (24.8%). On average the increase of total biomass at elevated CO 2 was greater for invasive species (70.3%) than for the natives (30.5%). Elevated CO 2 also resulted in significant changes in biomass allocation and morphology of invasive M. micrantha and W. trilobata. These results indicate a substantial variation in response to elevated CO 2 between these invasive and native plant species, which might be a potential mechanism partially explaining the success of invasion with ongoing increase in atmospheric CO 2.

  2. Changes in soil bacterial communities induced by the invasive plant Pennisetum setaceum in a semiarid environment

    NASA Astrophysics Data System (ADS)

    Rodriguez-Caballero, Gema; Caravaca, Fuensanta; del Mar Alguacil, María; Fernández-López, Manuel; José Fernández-González, Antonio; García-Orenes, Fuensanta; Roldán, Antonio

    2016-04-01

    Invasive alien species are considered as a global threat being among the main causes of biodiversity loss. Plant invasions have been extensively studied from different disciplines with the purpose of identifying predictor traits of invasiveness and finding solutions. However, less is known about the implication of the rhizosphere microbiota in these processes, even when it is well known the importance of the interaction between plant rhizosphere and microbial communities. The objective of this study was to determine whether native and invasive plants support different bacterial communities in their rhizospheres and whether there are bacterial indicator species that might be contributing to the invasion process of these ecosystems. We carried out a study in five independent locations under Mediterranean semiarid conditions, where the native Hyparrhenia hirta is being displaced by Pennisetum setaceum, an aggressive invasive Poaceae and soil bacterial communities were amplified and 454-pyrosequenced. Changes in the composition and structure of the bacterial communities, owing to the invasive status of the plant, were detected when the richness and alpha-diversity estimators were calculated as well as when we analyzed the PCoA axes scores. The Indicator Species Analysis results showed a higher number of indicators for invaded communities at all studied taxonomic levels. In conclusion, the effect of the invasiveness and its interaction with the soil location has promoted shifts in the rhizosphere bacterial communities which might be facilitating the invader success in these ecosystems.

  3. Does cryptic microbiota mitigate pine resistance to an invasive beetle-fungus complex? Implications for invasion potential.

    PubMed

    Cheng, Chihang; Xu, Letian; Xu, Dandan; Lou, Qiaozhe; Lu, Min; Sun, Jianghua

    2016-01-01

    Microbial symbionts are known to assist exotic pests in their colonization of new host plants. However, there has been little evidence linking symbiotic invasion success to mechanisms for mitigation of native plant resistance. The red turpentine beetle (RTB) was introduced with a fungus, Leptographium procerum, to China from the United States and became a destructively invasive symbiotic complex in natural Pinus tabuliformis forests. Here, we report that three Chinese-resident fungi, newly acquired by RTB in China, induce high levels of a phenolic defensive chemical, naringenin, in pines. This invasive beetle-fungus complex is suppressed by elevated levels of naringenin. However, cryptic microbiotas in RTB galleries strongly degrade naringenin, and pinitol, the main soluble carbohydrate of P. tabuliformis, is retained in L. procerum-infected phloem and facilitate naringenin biodegradation by the microbiotas. These results demonstrate that cryptic microbiota mitigates native host plant phenolic resistance to an invasive symbiotic complex, suggesting a putative mechanism for reduced biotic resistance to symbiotic invasion. PMID:27621032

  4. Does cryptic microbiota mitigate pine resistance to an invasive beetle-fungus complex? Implications for invasion potential

    PubMed Central

    Cheng, Chihang; Xu, Letian; Xu, Dandan; Lou, Qiaozhe; Lu, Min; Sun, Jianghua

    2016-01-01

    Microbial symbionts are known to assist exotic pests in their colonization of new host plants. However, there has been little evidence linking symbiotic invasion success to mechanisms for mitigation of native plant resistance. The red turpentine beetle (RTB) was introduced with a fungus, Leptographium procerum, to China from the United States and became a destructively invasive symbiotic complex in natural Pinus tabuliformis forests. Here, we report that three Chinese-resident fungi, newly acquired by RTB in China, induce high levels of a phenolic defensive chemical, naringenin, in pines. This invasive beetle-fungus complex is suppressed by elevated levels of naringenin. However, cryptic microbiotas in RTB galleries strongly degrade naringenin, and pinitol, the main soluble carbohydrate of P. tabuliformis, is retained in L. procerum-infected phloem and facilitate naringenin biodegradation by the microbiotas. These results demonstrate that cryptic microbiota mitigates native host plant phenolic resistance to an invasive symbiotic complex, suggesting a putative mechanism for reduced biotic resistance to symbiotic invasion. PMID:27621032

  5. Seedling germination success and survival of the invasive shrub Scotch broom ( Cytisus scoparius) in response to fire and experimental clipping in the montane grasslands of the Nilgiris, south India

    NASA Astrophysics Data System (ADS)

    Srinivasan, Madhusudan P.; Kalita, Ratul; Gurung, Inder K.; Bhattacharjee, Saroj K.; Antony, Predit M.; Krishnan, Suresh; Gleeson, Scott K.

    2012-01-01

    The spread of the exotic shrub Scotch broom in the montane grasslands of the Nilgiris is one of the major threats to biodiversity and ecosystem function there. It is likely that fire suppression over the past few decades is the proximate cause of expansion of broom populations. This study capitalizes on a wildfire event to examine fire effects on mature broom populations and soil seedbanks. Fire resulted in widespread death of mature broom stands but also stimulated broom soil seedbanks. However, this initial difference in seedling densities in burned and unburned plots was lost over time due to continuous recruitment in unburned plots. In a seed addition experiment, plots which were clipped prior to the fire showed higher germination success, possibly because fire temperature was moderated by biomass removal. In another experiment, non-dormant broom seeds were added to burned plots, which then received clipping treatments; there were no differences in broom seedling survival in clipped vs. unclipped plots. Overall, these results suggest that prescribed burning might contribute to the control of Scotch broom invasion by helping eliminate mature stands without significantly increasing regeneration from seed.

  6. Spread dynamics of invasive species

    PubMed Central

    Arim, Matías; Abades, Sebastián R.; Neill, Paula E.; Lima, Mauricio; Marquet, Pablo A.

    2006-01-01

    Species invasions are a principal component of global change, causing large losses in biodiversity as well as economic damage. Invasion theory attempts to understand and predict invasion success and patterns of spread. However, there is no consensus regarding which species or community attributes enhance invader success or explain spread dynamics. Experimental and theoretical studies suggest that regulation of spread dynamics is possible; however, the conditions for its existence have not yet been empirically demonstrated. If invasion spread is a regulated process, the structure that accounts for this regulation will be a main determinant of invasion dynamics. Here we explore the existence of regulation underlying changes in the rate of new site colonization. We employ concepts and analytical tools from the study of abundance dynamics and show that spread dynamics are, in fact, regulated processes and that the regulation structure is notably consistent among invasions occurring in widely different contexts. We base our conclusions on the analysis of the spread dynamics of 30 species invasions, including birds, amphibians, fish, invertebrates, plants, and a virus, all of which exhibited similar regulation structures. In contrast to current beliefs that species invasions are idiosyncratic phenomena, here we provide evidence that general patterns do indeed exist. PMID:16387862

  7. Adaptation to enemy shifts: rapid resistance evolution to local Vibrio spp. in invasive Pacific oysters

    PubMed Central

    Wendling, Carolin C.; Wegner, K. Mathias

    2015-01-01

    One hypothesis for the success of invasive species is reduced pathogen burden, resulting from a release from infections or high immunological fitness of invaders. Despite strong selection exerted on the host, the evolutionary response of invaders to newly acquired pathogens has rarely been considered. The two independent and genetically distinct invasions of the Pacific oyster Crassostrea gigas into the North Sea represent an ideal model system to study fast evolutionary responses of invasive populations. By exposing both invasion sources to ubiquitous and phylogenetically diverse pathogens (Vibrio spp.), we demonstrate that within a few generations hosts adapted to newly encountered pathogen communities. However, local adaptation only became apparent in selective environments, i.e. at elevated temperatures reflecting patterns of disease outbreaks in natural populations. Resistance against sympatric and allopatric Vibrio spp. strains was dominantly inherited in crosses between both invasion sources, resulting in an overall higher resistance of admixed individuals than pure lines. Therefore, we suggest that a simple genetic resistance mechanism of the host is matched to a common virulence mechanism shared by local Vibrio strains. This combination might have facilitated a fast evolutionary response that can explain another dimension of why invasive species can be so successful in newly invaded ranges. PMID:25716784

  8. Facilitating Facilitators: Enhancing PBL through a Structured Facilitator Development Program

    ERIC Educational Resources Information Center

    Salinitri, Francine D.; Wilhelm, Sheila M.; Crabtree, Brian L.

    2015-01-01

    With increasing adoption of the problem-based learning (PBL) model, creative approaches to enhancing facilitator training and optimizing resources to maintain effective learning in small groups is essential. We describe a theoretical framework for the development of a PBL facilitator training program that uses the constructivist approach as the…

  9. Isolation of invasive Plasmodium yoelii merozoites with a long half-life to evaluate invasion dynamics and potential invasion inhibitors.

    PubMed

    Mutungi, Joe Kimanthi; Yahata, Kazuhide; Sakaguchi, Miako; Kaneko, Osamu

    2015-11-01

    Malaria symptoms and pathogenesis are caused by blood stage parasite burdens of Plasmodium spp., for which invasion of red blood cells (RBCs) by merozoites is essential. Successful targeting by either drugs or vaccines directed against the whole merozoite or its antigens during its transient extracellular status would contribute to malaria control by impeding RBC invasion. To understand merozoite invasion biology and mechanisms, it is desired to obtain merozoites that retain their invasion activity in vitro. Accordingly, methods have been developed to isolate invasive Plasmodium knowlesi and Plasmodium falciparum merozoites. Rodent malaria parasite models offer ease in laboratory maintenance and experimental genetic modifications; however, no methods have been reported regarding isolation of high numbers of invasive rodent malaria merozoites. In this study, Plasmodium yoelii-infected RBCs were obtained from infected mice, and mature schizont-infected RBCs enriched via Histodenz™ density gradients. Merozoites retaining invasion activity were then isolated by passing the preparations through a filter membrane. RBC-invaded parasites developed to mature stages in vitro in a synchronous manner. Isolated merozoites were evaluated for retention of invasion activity following storage at different temperatures prior to incubation with uninfected mouse RBCs. Isolated merozoites retained their invasion activity 4h after isolation at 10 or 15 °C, whereas their invasion activity reduced to 0-10% within 30 min when incubated on ice or at 37 °C prior to RBC invasion assay. Images of merozoites at successive steps during RBC invasion were captured by light and transmission electron microscopy. Synthetic peptides derived from the amino acid sequence of the P. yoelii invasion protein RON2 efficiently inhibited RBC invasion. The developed method to isolate and keep invasive P. yoelii merozoites for up to 4h is a powerful tool to study the RBC invasion biology of this parasite

  10. Shifts in grassland invasibility: effects of soil resources, disturbance, composition, and invader size.

    PubMed

    Renne, Ian J; Tracy, Benjamin F; Colonna, Ignacio A

    2006-09-01

    There is an emerging recognition that invasibility is not an intrinsic community trait, but is a condition that fluctuates from interactions between environmental forces and residential characters. Elucidating the spatiotemporal complexities of invasion requires inclusion of multiple, ecologically variable factors within communities of differing structure. Water and nutrient amendments, disturbance, and local composition affect grassland invasibility but no study has simultaneously integrated these, despite evidence that they frequently interact. Using a split-plot factorial design, we tested the effects of these factors on the invasibility of C3 pasture communities by smooth pigweed Amaranthus hybridus L., a problematic C4 forb. We sowed seeds and transplanted 3-week old seedlings of A. hybridus into plots containing monocultures and mixtures of varying composition, subjected plots to water, soil disturbance, and synthetic bovine urine (SBU) treatments, and measured A. hybridus emergence, recruitment, and growth rate. Following SBU addition, transplanted seedling growth increased in all plots but differed among legume and nonlegume monocultures and mixtures of these plant types. However, SBU decreased the number and recruitment rate of emerged seedlings because high residential growth reduced light availability. Nutrient pulses can therefore have strong but opposing effects on invasibility, depending on when they coincide with particular life history stages of an invader. Indeed, in SBU-treated plots, small differences in height of transplanted seedlings early on produced large differences in their final biomass. All facilitative effects of small-scale disturbance on invasion success diminished when productivity-promoting factors were present, suggesting that disturbance patch size is important. Precipitation-induced invasion resistance of C3 pastures by a C4 invader was partly supported. In grazed grasslands, these biotic and environmental factors vary across

  11. USGS invasive species solutions

    USGS Publications Warehouse

    Simpson, Annie

    2011-01-01

    Land managers must meet the invasive species challenge every day, starting with identification of problem species, then the collection of best practices for their control, and finally the implementation of a plan to remove the problem. At each step of the process, the availability of reliable information is essential to success. The U.S. Geological Survey (USGS) has developed a suite of resources for early detection and rapid response, along with data management and sharing.

  12. Resolving the genetic basis of invasiveness and predicting invasions.

    PubMed

    Weinig, Cynthia; Brock, Marcus T; Dechaine, Jenny A; Welch, Stephen M

    2007-02-01

    Considerable effort has been invested in determining traits underlying invasiveness. Yet, identifying a set of traits that commonly confers invasiveness in a range of species has proven elusive, and almost nothing is known about genetic loci affecting invasive success. Incorporating genetic model organisms into ecologically relevant studies is one promising avenue to begin dissecting the genetic underpinnings of invasiveness. Molecular biologists are rapidly characterizing genes mediating developmental responses to diverse environmental cues, i.e., genes for plasticity, as well as to environmental factors likely to impose strong selection on invading species, e.g., resistance to herbivores and competitors, coordination of life-history events with seasonal changes, and physiological tolerance of heat, drought, or cold. Here, we give an overview of molecular genetic tools increasingly used to characterize the genetic basis of adaptation and that may be used to begin identifying genetic mechanisms of invasiveness. Given the divergent traits that affect invasiveness, "invasiveness genes" common to many clades are unlikely, but the combination of developmental genetic advances with further evolutionary studies and modeling may provide a framework for identifying genes that account for invasiveness in related species.

  13. Introduction to the Special Issue: The role of soil microbial-driven belowground processes in mediating exotic plant invasions

    PubMed Central

    Inderjit

    2015-01-01

    Soil microbial communities are one of the multiple factors that facilitate or resist plant invasion. Regional and biogeographic studies help to determine how soil communities and the processes mediated by soil microbes are linked to other mechanisms of invasion. Both the success of plant invasions and their impacts are profoundly influenced by a wide range of soil communities and the soil processes mediated by them. With an aim to better understand the mechanisms responsible for the soil community-driven routes, a special issue of AoB PLANTS was conceived. I hope that the range of papers included in the special issue will reveal some of the complexities in soil community-mediated plant invasion. PMID:25979967

  14. Getting Set for Success.

    ERIC Educational Resources Information Center

    Santa Rita, Emilio

    These career development materials consist of three booklets: the text, success portfolio, and facilitator's guide. Unit 1 in the text tests the students' coping skills. Contracts in the success portfolio for this unit enable the student to determine the sources of stress and ways of coping; describe different procedures for managing time; assess…

  15. Genetic reconstructions of invasion history.

    PubMed

    Cristescu, Melania E

    2015-05-01

    A diverse array of molecular markers and constantly evolving analytical approaches have been employed to reconstruct the invasion histories of the most notorious invasions. Detailed information on the source(s) of introduction, invasion route, type of vectors, number of independent introductions and pathways of secondary spread has been corroborated for a large number of biological invasions. In this review, I present the promises and limitations of current techniques while discussing future directions. Broad phylogeographic surveys of native and introduced populations have traced back invasion routes with surprising precision. These approaches often further clarify species boundaries and reveal complex patterns of genetic relationships with noninvasive relatives. Moreover, fine-scale analyses of population genetics or genomics allow deep inferences on the colonization dynamics across invaded ranges and can reveal the extent of gene flow among populations across various geographical scales, major demographic events such as genetic bottlenecks as well as other important evolutionary events such as hybridization with native taxa, inbreeding and selective sweeps. Genetic data have been often corroborated successfully with historical, geographical and ecological data to enable a comprehensive reconstruction of the invasion process. The advent of next-generation sequencing, along with the availability of extensive databases of repository sequences generated by barcoding projects opens the opportunity to broadly monitor biodiversity, to identify early invasions and to quantify failed invasions that would otherwise remain inconspicuous to the human eye. PMID:25703061

  16. The population biology of fungal invasions.

    PubMed

    Gladieux, P; Feurtey, A; Hood, M E; Snirc, A; Clavel, J; Dutech, C; Roy, M; Giraud, T

    2015-05-01

    Fungal invasions are increasingly recognized as a significant component of global changes, threatening ecosystem health and damaging food production. Invasive fungi also provide excellent models to evaluate the generality of results based on other eukaryotes. We first consider here the reasons why fungal invasions have long been overlooked: they tend to be inconspicuous, and inappropriate methods have been used for species recognition. We then review the information available on the patterns and mechanisms of fungal invasions. We examine the biological features underlying invasion success of certain fungal species. We review population structure analyses, revealing native source populations and strengths of bottlenecks. We highlight the documented ecological and evolutionary changes in invaded regions, including adaptation to temperature, increased virulence, hybridization, shifts to clonality and association with novel hosts. We discuss how the huge census size of most fungi allows adaptation even in bottlenecked, clonal invaders. We also present new analyses of the invasion of the anther-smut pathogen on white campion in North America, as a case study illustrating how an accurate knowledge of species limits and phylogeography of fungal populations can be used to decipher the origin of invasions. This case study shows that successful invasions can occur even when life history traits are particularly unfavourable to long-distance dispersal and even with a strong bottleneck. We conclude that fungal invasions are valuable models to contribute to our view of biological invasions, in particular by providing insights into the traits as well as ecological and evolutionary processes allowing successful introductions.

  17. SOST Inhibits Prostate Cancer Invasion

    PubMed Central

    Hudson, Bryan D.; Hum, Nicholas R.; Thomas, Cynthia B.; Kohlgruber, Ayano; Sebastian, Aimy; Collette, Nicole M.; Coleman, Matthew A.; Christiansen, Blaine A.; Loots, Gabriela G.

    2015-01-01

    Inhibitors of Wnt signaling have been shown to be involved in prostate cancer (PC) metastasis; however the role of Sclerostin (Sost) has not yet been explored. Here we show that elevated Wnt signaling derived from Sost deficient osteoblasts promotes PC invasion, while rhSOST has an inhibitory effect. In contrast, rhDKK1 promotes PC elongation and filopodia formation, morphological changes characteristic of an invasive phenotype. Furthermore, rhDKK1 was found to activate canonical Wnt signaling in PC3 cells, suggesting that SOST and DKK1 have opposing roles on Wnt signaling in this context. Gene expression analysis of PC3 cells co-cultured with OBs exhibiting varying amounts of Wnt signaling identified CRIM1 as one of the transcripts upregulated under highly invasive conditions. We found CRIM1 overexpression to also promote cell-invasion. These findings suggest that bone-derived Wnt signaling may enhance PC tropism by promoting CRIM1 expression and facilitating cancer cell invasion and adhesion to bone. We concluded that SOST and DKK1 have opposing effects on PC3 cell invasion and that bone-derived Wnt signaling positively contributes to the invasive phenotypes of PC3 cells by activating CRIM1 expression and facilitating PC-OB physical interaction. As such, we investigated the effects of high concentrations of SOST in vivo. We found that PC3-cells overexpressing SOST injected via the tail vein in NSG mice did not readily metastasize, and those injected intrafemorally had significantly reduced osteolysis, suggesting that targeting the molecular bone environment may influence bone metastatic prognosis in clinical settings. PMID:26545120

  18. SOST Inhibits Prostate Cancer Invasion.

    PubMed

    Hudson, Bryan D; Hum, Nicholas R; Thomas, Cynthia B; Kohlgruber, Ayano; Sebastian, Aimy; Collette, Nicole M; Coleman, Matthew A; Christiansen, Blaine A; Loots, Gabriela G

    2015-01-01

    Inhibitors of Wnt signaling have been shown to be involved in prostate cancer (PC) metastasis; however the role of Sclerostin (Sost) has not yet been explored. Here we show that elevated Wnt signaling derived from Sost deficient osteoblasts promotes PC invasion, while rhSOST has an inhibitory effect. In contrast, rhDKK1 promotes PC elongation and filopodia formation, morphological changes characteristic of an invasive phenotype. Furthermore, rhDKK1 was found to activate canonical Wnt signaling in PC3 cells, suggesting that SOST and DKK1 have opposing roles on Wnt signaling in this context. Gene expression analysis of PC3 cells co-cultured with OBs exhibiting varying amounts of Wnt signaling identified CRIM1 as one of the transcripts upregulated under highly invasive conditions. We found CRIM1 overexpression to also promote cell-invasion. These findings suggest that bone-derived Wnt signaling may enhance PC tropism by promoting CRIM1 expression and facilitating cancer cell invasion and adhesion to bone. We concluded that SOST and DKK1 have opposing effects on PC3 cell invasion and that bone-derived Wnt signaling positively contributes to the invasive phenotypes of PC3 cells by activating CRIM1 expression and facilitating PC-OB physical interaction. As such, we investigated the effects of high concentrations of SOST in vivo. We found that PC3-cells overexpressing SOST injected via the tail vein in NSG mice did not readily metastasize, and those injected intrafemorally had significantly reduced osteolysis, suggesting that targeting the molecular bone environment may influence bone metastatic prognosis in clinical settings.

  19. Invasive plants have broader physiological niches.

    PubMed

    Higgins, Steven I; Richardson, David M

    2014-07-22

    Invasive species cost the global economy billions of dollars each year, but ecologists have struggled to predict the risk of an introduced species naturalizing and invading. Although carefully designed experiments are needed to fully elucidate what makes some species invasive, much can be learned from unintentional experiments involving the introduction of species beyond their native ranges. Here, we assess invasion risk by linking a physiologically based species distribution model with data on the invasive success of 749 Australian acacia and eucalypt tree species that have, over more than a century, been introduced around the world. The model correctly predicts 92% of occurrences observed outside of Australia from an independent dataset. We found that invasiveness is positively associated with the projection of physiological niche volume in geographic space, thereby illustrating that species tolerant of a broader range of environmental conditions are more likely to be invasive. Species achieve this broader tolerance in different ways, meaning that the traits that define invasive success are context-specific. Hence, our study reconciles studies that have failed to identify the traits that define invasive success with the urgent and pragmatic need to predict invasive success.

  20. Pronounced and prevalent intersexuality does not impede the ‘Demon Shrimp’ invasion

    PubMed Central

    Green Etxabe, Amaia; Short, Stephen; Flood, Tim; Johns, Tim

    2015-01-01

    Crustacean intersexuality is widespread and often linked to infection by sex-distorting parasites. However, unlike vertebrate intersexuality, its association with sexual dysfunction is unclear and remains a matter of debate. The ‘Demon Shrimp,’ Dikerogammarus haemobaphes, an amphipod that has invaded continental waterways, has recently become widespread in Britain. Intersexuality has been noted in D. haemobaphes but not investigated further. We hypothesise that a successful invasive population should not display a high prevalence of intersexuality if this condition represents a truly dysfunctional phenotype. In addition, experiments have indicated that particular parasite burdens in amphipods may facilitate invasions. The rapid and ongoing invasion of British waterways represents an opportunity to determine whether these hypotheses are consistent with field observations. This study investigates the parasites and sexual phenotypes of D. haemobaphes in British waterways, characterising parasite burdens using molecular screening, and makes comparisons with the threatened Gammarus pulex natives. We reveal that invasive and native populations have distinct parasitic profiles, suggesting the loss of G. pulex may have parasite-mediated eco-system impacts. Furthermore, the parasite burdens are consistent with those previously proposed to facilitate biological invasions. Our study also indicates that while no intersexuality occurs in the native G. pulex, approximately 50% of D. haemobaphes males present pronounced intersexuality associated with infection by the microsporidian Dictyocoela berillonum. This unambiguously successful invasive population presents, to our knowledge, the highest reported prevalence of male intersexuality. This is the clearest evidence to date that such intersexuality does not represent a form of debilitating sexual dysfunction that negatively impacts amphipod populations. PMID:25699206

  1. Physical Stress, Not Biotic Interactions, Preclude an Invasive Grass from Establishing in Forb-Dominated Salt Marshes

    PubMed Central

    He, Qiang; Cui, Baoshan; An, Yuan

    2012-01-01

    Background Biological invasions have become the focus of considerable concern and ecological research, yet the relative importance of abiotic and biotic factors in controlling the invasibility of habitats to exotic species is not well understood. Spartina species are highly invasive plants in coastal wetlands; however, studies on the factors that control the success or failure of Spartina invasions across multiple habitat types are rare and inconclusive. Methodology and Principal Findings We examined the roles of physical stress and plant interactions in mediating the establishment of the smooth cordgrass, Spartina alterniflora, in a variety of coastal habitats in northern China. Field transplant experiments showed that cordgrass can invade mudflats and low estuarine marshes with low salinity and frequent flooding, but cannot survive in salt marshes and high estuarine marshes with hypersaline soils and infrequent flooding. The dominant native plant Suaeda salsa had neither competitive nor facilitative effects on cordgrass. A common garden experiment revealed that cordgrass performed significantly better when flooded every other day than when flooded weekly. These results suggest that physical stress rather than plant interactions limits cordgrass invasions in northern China. Conclusions and Significance We conclude that Spartina invasions are likely to be constrained to tidal flats and low estuarine marshes in the Yellow River Delta. Due to harsh physical conditions, salt marshes and high estuarine marshes are unlikely to be invaded. These findings have implications for understanding Spartina invasions in northern China and on other coasts with similar biotic and abiotic environments. PMID:22432003

  2. Principles for ecologically based invasive plant management

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Land managers long have identified a critical need for a practical and effective framework to guide the implementation of successful restoration, especially where invasive plants dominate the ecosystem. A holistic, ecologically-based invasive plant management (EBIPM) framework that integrates ecosy...

  3. Morphological and Physiological Compensation Promote Climate-Induced Invasions Above and below Treeline

    NASA Astrophysics Data System (ADS)

    Winkler, D. E.; Huxman, T. E.; Kudo, G.

    2014-12-01

    Elucidating the mechanisms underlying invasive species success is a challenge in ecology. Treeline ecotones are eminently suited to address this challenge given their sensitivity to climate change and the different abiotic filters in place over short distances. The invasive dwarf bamboo Sasa kurilensis has had pronounced effects on Japanese alpine plant communities, including the loss of over 1/3 of native species in some areas. The drivers of S. kurilensis invasions remain unresolved. We evaluated S. kurilensis stands along elevation and moisture gradients in Daisetsuzan National Park (Hokkaido, Japan) to identify strategy shifts that might facilitate invasions. We anticipated morphological responses to be correlated with invasion above treeline, while physiological processes to be more coordinated below treeline, reflecting different ecological filters in place within each community. We compared growth patterns and plant water status in the native (i.e., montane forests) and invasive (i.e., subalpine and alpine meadows) ranges of S. kurilensis. Dwarf bamboo at native lower elevations were taller than those at newly-invaded upper limits, indicating light limitation and investment in culm elongation. Culms in the native range grew faster than those at higher elevations. In contrast, culm density increased and plants allocated more to photosynthetic structures in invaded areas without overstory. Plants tended to invade drier soils but showed increased water stress, likely compensating by producing more photosynthetic structures to promote carbon gain. Overall, our results reveal dwarf bamboo exhibits both morphological and physiological variation across treeline ecotones. This appears to enable it to successfully invade subalpine and alpine communities while responding to a new climate. This pattern of variation coupled with changing soil dynamics as a result of earlier snowmelt will likely continue to promote the invasion of S. kurilensis into these systems

  4. Transposable elements as agents of rapid adaptation may explain the genetic paradox of invasive species.

    PubMed

    Stapley, Jessica; Santure, Anna W; Dennis, Stuart R

    2015-05-01

    Rapid adaptation of invasive species to novel habitats has puzzled evolutionary biologists for decades, especially as this often occurs in the face of limited genetic variability. Although some ecological traits common to invasive species have been identified, little is known about the possible genomic/genetic mechanisms that may underlie their success. A common scenario in many introductions is that small founder population sizes will often lead to reduced genetic diversity, but that invading populations experience large environmental perturbations, such as changes in habitat and environmental stress. Although sudden and intense stress is usually considered in a negative context, these perturbations may actually facilitate rapid adaptation by affecting genome structure, organization and function via interactions with transposable elements (TEs), especially in populations with low genetic diversity. Stress-induced changes in TE activity can alter gene action and can promote structural variation that may facilitate the rapid adaptation observed in new environments. We focus here on the adaptive potential of TEs in relation to invasive species and highlight their role as powerful mutational forces that can rapidly create genetic diversity. We hypothesize that activity of transposable elements can explain rapid adaptation despite low genetic variation (the genetic paradox of invasive species), and provide a framework under which this hypothesis can be tested using recently developed and emerging genomic technologies.

  5. Antagonistic interactions between an invasive alien and a native coccinellid species may promote coexistence.

    PubMed

    Hentley, William T; Vanbergen, Adam J; Beckerman, Andrew P; Brien, Melanie N; Hails, Rosemary S; Jones, T Hefin; Johnson, Scott N

    2016-07-01

    Despite the capacity of invasive alien species to alter ecosystems, the mechanisms underlying their impact remain only partly understood. Invasive alien predators, for example, can significantly disrupt recipient communities by consuming prey species or acting as an intraguild predator (IGP). Behavioural interactions are key components of interspecific competition between predators, yet these are often overlooked invasion processes. Here, we show how behavioural, non-lethal IGP interactions might facilitate the establishment success of an invading alien species. We experimentally assessed changes in feeding behaviour (prey preference and consumption rate) of native UK coccinellid species (Adalia bipunctata and Coccinella septempunctata), whose populations are, respectively, declining and stable, when exposed to the invasive intraguild predator, Harmonia axyridis. Using a population dynamics model parameterized with these experimental data, we predicted how intraguild predation, accommodating interspecific behavioural interactions, might impact the abundance of the native and invasive alien species over time. When competing for the same aphid resource, the feeding rate of A. bipunctata significantly increased compared to the feeding in isolation, while the feeding rate of H. axyridis significantly decreased. This suggests that despite significant declines in the UK, A. bipunctata is a superior competitor to the intraguild predator H. axyridis. In contrast, the behaviour of non-declining C. septempunctata was unaltered by the presence of H. axyridis. Our experimental data show the differential behavioural plasticity of competing native and invasive alien predators, but do not explain A. bipunctata declines observed in the UK. Using behavioural plasticity as a parameter in a population dynamic model for A. bipunctata and H. axyridis, coexistence is predicted between the native and invasive alien following an initial period of decline in the native species. We

  6. Antagonistic interactions between an invasive alien and a native coccinellid species may promote coexistence.

    PubMed

    Hentley, William T; Vanbergen, Adam J; Beckerman, Andrew P; Brien, Melanie N; Hails, Rosemary S; Jones, T Hefin; Johnson, Scott N

    2016-07-01

    Despite the capacity of invasive alien species to alter ecosystems, the mechanisms underlying their impact remain only partly understood. Invasive alien predators, for example, can significantly disrupt recipient communities by consuming prey species or acting as an intraguild predator (IGP). Behavioural interactions are key components of interspecific competition between predators, yet these are often overlooked invasion processes. Here, we show how behavioural, non-lethal IGP interactions might facilitate the establishment success of an invading alien species. We experimentally assessed changes in feeding behaviour (prey preference and consumption rate) of native UK coccinellid species (Adalia bipunctata and Coccinella septempunctata), whose populations are, respectively, declining and stable, when exposed to the invasive intraguild predator, Harmonia axyridis. Using a population dynamics model parameterized with these experimental data, we predicted how intraguild predation, accommodating interspecific behavioural interactions, might impact the abundance of the native and invasive alien species over time. When competing for the same aphid resource, the feeding rate of A. bipunctata significantly increased compared to the feeding in isolation, while the feeding rate of H. axyridis significantly decreased. This suggests that despite significant declines in the UK, A. bipunctata is a superior competitor to the intraguild predator H. axyridis. In contrast, the behaviour of non-declining C. septempunctata was unaltered by the presence of H. axyridis. Our experimental data show the differential behavioural plasticity of competing native and invasive alien predators, but do not explain A. bipunctata declines observed in the UK. Using behavioural plasticity as a parameter in a population dynamic model for A. bipunctata and H. axyridis, coexistence is predicted between the native and invasive alien following an initial period of decline in the native species. We

  7. The Argentine ant persists through unfavorable winters via a mutualism facilitated by a native tree.

    PubMed

    Brightwell, Robert J; Silverman, Jules

    2011-10-01

    Mutualisms and facilitations can fundamentally change the relationship between an organism's realized and fundamental niche. Invasive species may prove particularly suitable models for investigating this relationship as many are dependent on finding new partners for successful establishment. We conducted field-based experiments testing whether a native tree facilitates the successful survival of the invasive Argentine ant, Linepithema humile (Mayr), through unfavorable winter conditions in the southeastern United States. We found Argentine ant nests aggregated around the native loblolly pine, Pinus taeda L., during the winter months. The bark of this tree absorbed enough radiant solar energy to reach temperatures suitable for Argentine ant foraging even when ambient temperatures should have curtailed all foraging. Conversely, foraging ceased when the trunk was shaded. The sun-warmed bark of this tree gave the Argentine ant access to a stable honeydew resource. Argentine ants were not found on or near deciduous trees even though bark temperatures were warm enough to permit Argentine ant foraging on cold winter days. Augmenting deciduous trees with sucrose water through the winter months lead to Argentine ant nests remaining at their base and Argentine ants foraging on the tree. The Argentine ant requires both foraging opportunity and a reliable winter food source to survive through unfavorable winter conditions in the southeastern United States. The loblolly pine provided both of these requirements extending the realized niche of Argentine ants beyond its fundamental niche.

  8. [Emerging invasive fungal infections].

    PubMed

    Alvez, F; Figueras, C; Roselló, E

    2010-07-01

    The frequency and diversity of invasive fungal infections has changed over the last 25 years. The emergence of less common, but medically important fungi has increased, and the children at risk has expanded, with the inclusion of medical conditions such as cancer, mainly haematological malignancy or stem cell transplant, immunosuppressive therapy, prolonged neutropenia, and T-cell immunodeficiency. Among mould infections, fusariosis and phaeohyphomycosis (Dematiaceous fungi) have been increasingly reported in this group of patients. To successfully manage these challenging infections, it is imperative that paediatricians and sub-specialists remain aware of the optimal and timely diagnosis and therapeutic options. Unlike other common mycoses that cause human disease, there no simple antigen or serological tests available to detect these pathogens in tissue or blood. The outcome for these disseminate, and often refractory fungal infections in neutropenic patients and transplant recipients remains extremely poor, requiring early and aggressive therapy. Unfortunately there are no guidelines outlining the choices for optimal therapy in the treatment of paediatric invasive fungal infections do not exist, and on the other hand are limited paediatric data available comparing antifungal agents in children with proven, probable or suspected invasive fungal infection. The options for treatment rest mainly on some adult guidelines that comment on the treatment of these emerging and uncommon important fungi in children. Despite the sparse clinical trials available on treatment and its poor outcome, options for treatment of invasive fungal infections have increased with the advance of new antifungal agents, with improved tolerability and increased range of activity. The epidemiology, clinical manifestations, diagnosis and treatment of fusariosis and phaeohyphomycosis are discussed in this article.

  9. Cane toads lack physiological enhancements for dispersal at the invasive front in Northern Australia.

    PubMed

    Tracy, Christopher R; Christian, Keith A; Baldwin, John; Phillips, Ben L

    2012-01-15

    Many invasive species have evolved behavioural and morphological characteristics that facilitate their dispersal into new areas, but it is unclear how selection on this level of the phenotype filters through to the underlying physiology. Cane toads have been dispersing westward across northern tropical Australia for more than 70 years. Previous studies of cane toads at the invasive front have identified several behavioural, morphological and locomotory characteristics that have evolved to facilitate dispersal of toads. We assessed a range of physiological characteristics associated with locomotory abilities in toads from the long-established, east coast of Australia, from the invasive front, and from a site in between these locations. We measured time to exhaustion and respiratory gases of toads exercising on a treadmill, time to recovery from exhaustion, blood properties (lactate, haematocrit, haemoglobin, red blood cell count, blood cell volume), and muscle properties associated with locomotion (activities of the enzymes citrate synthase and lactate dehydrogenase, and pH buffering capacity). None of the measured physiological parameters supported the hypothesis that toads from the invasive front possess physiological adaptations that facilitate dispersal compared to toads from areas colonised in the past. The strongest difference among the three groups of toads, time to exhaustion, showed exactly the opposite trend; toads from the long-established populations in the east coast had the longest time to exhaustion. Successful colonisers can employ many characteristics to facilitate their dispersal, so the extent to which behaviour, morphology and physiology co-evolve remains an interesting question. However, in the present case at least, behavioural adaptations do not appear to have altered the organism's underlying physiology.

  10. Adopting a new philosophy: minimal invasion.

    PubMed

    Whitehouse, Joseph A

    2006-06-01

    Dentistry is a dynamic profession with new trends evolving. Minimally invasive dentistry is becoming not just a concept but a way of practicing. Creative people are finding ways, materials, and technology that enable patients to experience less hard-tissue or soft-tissue removal, improved prevention and maintenance, and increased attention to a philosophy of "less is more." The World Congress of Minimally Invasive Dentistry was formed to facilitate the sharing of these new concepts. The members embrace change, and dentistry offers the constant opportunity for such. As the standard of care moves toward minimally invasive dentistry, patients will benefit. PMID:16792118

  11. Facilitating Organizational Change.

    ERIC Educational Resources Information Center

    1999

    The first of the three papers in this symposium, "Conflicts that Arise in Small Group Facilitation: A Descriptive Study of Accounts, Actions, Outcomes, and Assessments" (Judith A. Kolb, William J. Rothwell), contains self-report verbatim accounts contributed by facilitators and the results of a literature review on small group conflict. "A Test of…

  12. A Facilitation Performance Aid.

    ERIC Educational Resources Information Center

    Chevalier, Roger

    1997-01-01

    Presents a guide, derived from the Situational Leadership model, which describes the process that should be used in facilitating a group discussion. The process includes preparation, assessment, diagnosis, prescription, development, reinforcement, and follow-up. Three figures depict the Situational Leadership model, the facilitation process, and…

  13. Aquatic invasive species: Lessons from cancer research

    USGS Publications Warehouse

    Sepulveda, Adam; Ray, Andrew; Al-Chokhachy, Robert K.; Muhlfeld, Clint C.; Gresswell, Robert E.; Gross, Jackson A.; Kershner, Jeffrey L.

    2014-01-01

    Aquatic invasive species are disrupting ecosystems with increasing frequency. Successful control of these invasions has been rare: Biologists and managers have few tools for fighting aquatic invaders. In contrast, the medical community has long worked to develop tools for preventing and fighting cancer. Its successes are marked by a coordinated research approach with multiple steps: prevention, early detection, diagnosis, treatment options and rehabilitation. The authors discuss how these steps can be applied to aquatic invasive species, such as the American bullfrog (Lithobates catesbeianus), in the Northern Rocky Mountain region of the United States, to expedite tool development and implementation along with achievement of biodiversity conservation goals.

  14. Evolutionary mechanisms of habitat invasions, using the copepod Eurytemora affinis as a model system.

    PubMed

    Lee, Carol Eunmi

    2016-01-01

    The study of the copepod Eurytemora affinis has provided unprecedented insights into mechanisms of invasive success. In this invited review, I summarize a subset of work from my laboratory to highlight key insights gained from studying E. affinis as a model system. Invasive species with brackish origins are overrepresented in freshwater habitats. The copepod E. affinis is an example of such a brackish invader, and has invaded freshwater habitats multiple times independently in recent years. These invasions were accompanied by the evolution of physiological tolerance and plasticity, increased body fluid regulation, and evolutionary shifts in ion transporter (V-type H(+) ATPase, Na(+), K(+)-ATPase) activity and expression. These evolutionary changes occurred in parallel across independent invasions in nature and in laboratory selection experiments. Selection appears to act on standing genetic variation during invasions, and maintenance of this variation is likely facilitated through 'beneficial reversal of dominance' in salinity tolerance across habitats. Expression of critical ion transporters is localized in newly discovered Crusalis leg organs. Increased freshwater tolerance is accompanied by costs to development time and greater requirements for food. High-food concentration increases low-salinity tolerance, allowing saline populations to invade freshwater habitats. Mechanisms observed here likely have relevance for other taxa undergoing fundamental niche expansions. PMID:27087851

  15. Evolutionary mechanisms of habitat invasions, using the copepod Eurytemora affinis as a model system.

    PubMed

    Lee, Carol Eunmi

    2016-01-01

    The study of the copepod Eurytemora affinis has provided unprecedented insights into mechanisms of invasive success. In this invited review, I summarize a subset of work from my laboratory to highlight key insights gained from studying E. affinis as a model system. Invasive species with brackish origins are overrepresented in freshwater habitats. The copepod E. affinis is an example of such a brackish invader, and has invaded freshwater habitats multiple times independently in recent years. These invasions were accompanied by the evolution of physiological tolerance and plasticity, increased body fluid regulation, and evolutionary shifts in ion transporter (V-type H(+) ATPase, Na(+), K(+)-ATPase) activity and expression. These evolutionary changes occurred in parallel across independent invasions in nature and in laboratory selection experiments. Selection appears to act on standing genetic variation during invasions, and maintenance of this variation is likely facilitated through 'beneficial reversal of dominance' in salinity tolerance across habitats. Expression of critical ion transporters is localized in newly discovered Crusalis leg organs. Increased freshwater tolerance is accompanied by costs to development time and greater requirements for food. High-food concentration increases low-salinity tolerance, allowing saline populations to invade freshwater habitats. Mechanisms observed here likely have relevance for other taxa undergoing fundamental niche expansions.

  16. Esophagectomy - minimally invasive

    MedlinePlus

    Minimally invasive esophagectomy; Robotic esophagectomy; Removal of the esophagus - minimally invasive; Achalasia - esophagectomy; Barrett esophagus - esophagectomy; Esophageal cancer - esophagectomy - laparoscopic; Cancer of the ...

  17. Excluding access to invasion hubs can contain the spread of an invasive vertebrate

    PubMed Central

    Florance, Daniel; Webb, Jonathan K.; Dempster, Tim; Kearney, Michael R.; Worthing, Alex; Letnic, Mike

    2011-01-01

    Many biological invasions do not occur as a gradual expansion along a continuous front, but result from the expansion of satellite populations that become established at ‘invasion hubs’. Although theoretical studies indicate that targeting control efforts at invasion hubs can effectively contain the spread of invasions, few studies have demonstrated this in practice. In arid landscapes worldwide, humans have increased the availability of surface water by creating artificial water points (AWPs) such as troughs and dams for livestock. By experimentally excluding invasive cane toads (Bufo marinus) from AWP, we show that AWP provide a resource subsidy for non-arid-adapted toads and serve as dry season refuges and thus invasion hubs for cane toads in arid Australia. Using data on the distribution of permanent water in arid Australia and the dispersal potential of toads, we predict that systematically excluding toads from AWP would reduce the area of arid Australia across which toads are predicted to disperse and colonize under average climatic conditions by 38 per cent from 2 242 000 to 1 385 000 km2. Our study shows how human modification of hydrological regimes can create a network of invasion hubs that facilitates a biological invasion, and confirms that targeted control at invasion hubs can reduce landscape connectivity to contain the spread of an invasive vertebrate. PMID:21345870

  18. Excluding access to invasion hubs can contain the spread of an invasive vertebrate.

    PubMed

    Florance, Daniel; Webb, Jonathan K; Dempster, Tim; Kearney, Michael R; Worthing, Alex; Letnic, Mike

    2011-10-01

    Many biological invasions do not occur as a gradual expansion along a continuous front, but result from the expansion of satellite populations that become established at 'invasion hubs'. Although theoretical studies indicate that targeting control efforts at invasion hubs can effectively contain the spread of invasions, few studies have demonstrated this in practice. In arid landscapes worldwide, humans have increased the availability of surface water by creating artificial water points (AWPs) such as troughs and dams for livestock. By experimentally excluding invasive cane toads (Bufo marinus) from AWP, we show that AWP provide a resource subsidy for non-arid-adapted toads and serve as dry season refuges and thus invasion hubs for cane toads in arid Australia. Using data on the distribution of permanent water in arid Australia and the dispersal potential of toads, we predict that systematically excluding toads from AWP would reduce the area of arid Australia across which toads are predicted to disperse and colonize under average climatic conditions by 38 per cent from 2,242,000 to 1,385,000 km(2). Our study shows how human modification of hydrological regimes can create a network of invasion hubs that facilitates a biological invasion, and confirms that targeted control at invasion hubs can reduce landscape connectivity to contain the spread of an invasive vertebrate. PMID:21345870

  19. Invasive congeners differ in successional impacts across space and time.

    PubMed

    David, Aaron S; Zarnetske, Phoebe L; Hacker, Sally D; Ruggiero, Peter; Biel, Reuben G; Seabloom, Eric W

    2015-01-01

    Invasive species can alter the succession of ecological communities because they are often adapted to the disturbed conditions that initiate succession. The extent to which this occurs may depend on how widely they are distributed across environmental gradients and how long they persist over the course of succession. We focus on plant communities of the USA Pacific Northwest coastal dunes, where disturbance is characterized by changes in sediment supply, and the plant community is dominated by two introduced grasses--the long-established Ammophila arenaria and the currently invading A. breviligulata. Previous studies showed that A. breviligulata has replaced A. arenaria and reduced community diversity. We hypothesize that this is largely due to A. breviligulata occupying a wider distribution across spatial environmental gradients and persisting in later-successional habitat than A. arenaria. We used multi-decadal chronosequences and a resurvey study spanning 2 decades to characterize distributions of both species across space and time, and investigated how these distributions were associated with changes in the plant community. The invading A. breviligulata persisted longer and occupied a wider spatial distribution across the dune, and this corresponded with a reduction in plant species richness and native cover. Furthermore, backdunes previously dominated by A. arenaria switched to being dominated by A. breviligulata, forest, or developed land over a 23-yr period. Ammophila breviligulata likely invades by displacing A. arenaria, and reduces plant diversity by maintaining its dominance into later successional backdunes. Our results suggest distinct roles in succession, with A. arenaria playing a more classically facilitative role and A. breviligulata a more inhibitory role. Differential abilities of closely-related invasive species to persist through time and occupy heterogeneous environments allows for distinct impacts on communities during succession.

  20. Invasive Congeners Differ in Successional Impacts across Space and Time

    PubMed Central

    David, Aaron S.; Zarnetske, Phoebe L.; Hacker, Sally D.; Ruggiero, Peter; Biel, Reuben G.; Seabloom, Eric W.

    2015-01-01

    Invasive species can alter the succession of ecological communities because they are often adapted to the disturbed conditions that initiate succession. The extent to which this occurs may depend on how widely they are distributed across environmental gradients and how long they persist over the course of succession. We focus on plant communities of the USA Pacific Northwest coastal dunes, where disturbance is characterized by changes in sediment supply, and the plant community is dominated by two introduced grasses – the long-established Ammophila arenaria and the currently invading A. breviligulata. Previous studies showed that A. breviligulata has replaced A. arenaria and reduced community diversity. We hypothesize that this is largely due to A. breviligulata occupying a wider distribution across spatial environmental gradients and persisting in later-successional habitat than A. arenaria. We used multi-decadal chronosequences and a resurvey study spanning 2 decades to characterize distributions of both species across space and time, and investigated how these distributions were associated with changes in the plant community. The invading A. breviligulata persisted longer and occupied a wider spatial distribution across the dune, and this corresponded with a reduction in plant species richness and native cover. Furthermore, backdunes previously dominated by A. arenaria switched to being dominated by A. breviligulata, forest, or developed land over a 23-yr period. Ammophila breviligulata likely invades by displacing A. arenaria, and reduces plant diversity by maintaining its dominance into later successional backdunes. Our results suggest distinct roles in succession, with A. arenaria playing a more classically facilitative role and A. breviligulata a more inhibitory role. Differential abilities of closely-related invasive species to persist through time and occupy heterogeneous environments allows for distinct impacts on communities during succession. PMID

  1. Geographical variations in adult body size and reproductive life history traits in an invasive anuran, Discoglossus pictus.

    PubMed

    Oromi, Neus; Pujol-Buxó, Eudald; San Sebastián, Olatz; Llorente, Gustavo A; Hammou, Mohamed Aït; Sanuy, Delfi

    2016-06-01

    Variability in life history traits positively affects the establishment and expansive potential of invasive species. In the present study, we analysed the variation of body size in seven populations - two native and five invasive - of the painted frog (Discoglossus pictus, Anura: Discoglossidae), native to North Africa and introduced in southern France and the north-east of the Iberian Peninsula. Other life history traits (age at maturity, size at maturity, longevity, median age and potential reproductive lifespan) were analysed in a native and an invasive population. We observed geographic variations in adult body size, related mainly to mean annual precipitation. Thus, populations had greater body size as mean annual precipitation increased, resulting in bigger specimens in the invasive populations. Adult body size and growth rates also varied between sexes in all studied populations, with males significantly larger than females. Age distribution varied between native (1-5 years) and invasive populations (2-4 years) and also between sexes. Our results suggest that higher precipitation promotes faster growth rates and larger adult body size that could facilitate the successful establishment of invasive populations.

  2. Twelve years of repeated wild hog activity promotes population maintenance of an invasive clonal plant in a coastal dune ecosystem.

    PubMed

    Oldfield, Callie A; Evans, Jonathan P

    2016-04-01

    Invasive animals can facilitate the success of invasive plant populations through disturbance. We examined the relationship between the repeated foraging disturbance of an invasive animal and the population maintenance of an invasive plant in a coastal dune ecosystem. We hypothesized that feral wild hog (Sus scrofa) populations repeatedly utilized tubers of the clonal perennial, yellow nutsedge (Cyperus esculentus) as a food source and evaluated whether hog activity promoted the long-term maintenance of yellow nutsedge populations on St. Catherine's Island, Georgia, United States. Using generalized linear mixed models, we tested the effect of wild hog disturbance on permanent sites for yellow nutsedge culm density, tuber density, and percent cover of native plant species over a 12-year period. We found that disturbance plots had a higher number of culms and tubers and a lower percentage of native live plant cover than undisturbed control plots. Wild hogs redisturbed the disturbed plots approximately every 5 years. Our research provides demographic evidence that repeated foraging disturbances by an invasive animal promote the long-term population maintenance of an invasive clonal plant. Opportunistic facultative interactions such as we demonstrate in this study are likely to become more commonplace as greater numbers of introduced species are integrated into ecological communities around the world.

  3. Twelve years of repeated wild hog activity promotes population maintenance of an invasive clonal plant in a coastal dune ecosystem.

    PubMed

    Oldfield, Callie A; Evans, Jonathan P

    2016-04-01

    Invasive animals can facilitate the success of invasive plant populations through disturbance. We examined the relationship between the repeated foraging disturbance of an invasive animal and the population maintenance of an invasive plant in a coastal dune ecosystem. We hypothesized that feral wild hog (Sus scrofa) populations repeatedly utilized tubers of the clonal perennial, yellow nutsedge (Cyperus esculentus) as a food source and evaluated whether hog activity promoted the long-term maintenance of yellow nutsedge populations on St. Catherine's Island, Georgia, United States. Using generalized linear mixed models, we tested the effect of wild hog disturbance on permanent sites for yellow nutsedge culm density, tuber density, and percent cover of native plant species over a 12-year period. We found that disturbance plots had a higher number of culms and tubers and a lower percentage of native live plant cover than undisturbed control plots. Wild hogs redisturbed the disturbed plots approximately every 5 years. Our research provides demographic evidence that repeated foraging disturbances by an invasive animal promote the long-term population maintenance of an invasive clonal plant. Opportunistic facultative interactions such as we demonstrate in this study are likely to become more commonplace as greater numbers of introduced species are integrated into ecological communities around the world. PMID:27110354

  4. Managing and facilitating innovation and nurse satisfaction.

    PubMed

    Weston, Marla J

    2009-01-01

    Behaviors and actions that foster innovation are complementary to those associated with managing and facilitating nurse satisfaction. These include creating an organizational climate that encourages the generation, sharing, and implementation of new ideas; managing with the skills to hire and retain competent and creative individuals; and establishing the infrastructure and processes to recognize and embed best and promising practices into the organization. The ability to innovate and to manage and facilitate nurse satisfaction is a necessary competency for organizational success. PMID:19893447

  5. Ecological principles underpinning invasive plant management tools and strategies

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The broad focus of ecologically-based invasive plant management is to identify and repair the ecological processes facilitating plant invasion. To be useful, however, EBIPM requires that our application of management tools and strategies be based on ecological principles that determine the rate and ...

  6. A functional trait perspective on plant invasion

    PubMed Central

    Drenovsky, Rebecca E.; Grewell, Brenda J.; D'Antonio, Carla M.; Funk, Jennifer L.; James, Jeremy J.; Molinari, Nicole; Parker, Ingrid M.; Richards, Christina L.

    2012-01-01

    Background and Aims Global environmental change will affect non-native plant invasions, with profound potential impacts on native plant populations, communities and ecosystems. In this context, we review plant functional traits, particularly those that drive invader abundance (invasiveness) and impacts, as well as the integration of these traits across multiple ecological scales, and as a basis for restoration and management. Scope We review the concepts and terminology surrounding functional traits and how functional traits influence processes at the individual level. We explore how phenotypic plasticity may lead to rapid evolution of novel traits facilitating invasiveness in changing environments and then ‘scale up’ to evaluate the relative importance of demographic traits and their links to invasion rates. We then suggest a functional trait framework for assessing per capita effects and, ultimately, impacts of invasive plants on plant communities and ecosystems. Lastly, we focus on the role of functional trait-based approaches in invasive species management and restoration in the context of rapid, global environmental change. Conclusions To understand how the abundance and impacts of invasive plants will respond to rapid environmental changes it is essential to link trait-based responses of invaders to changes in community and ecosystem properties. To do so requires a comprehensive effort that considers dynamic environmental controls and a targeted approach to understand key functional traits driving both invader abundance and impacts. If we are to predict future invasions, manage those at hand and use restoration technology to mitigate invasive species impacts, future research must focus on functional traits that promote invasiveness and invader impacts under changing conditions, and integrate major factors driving invasions from individual to ecosystem levels. PMID:22589328

  7. Master of all trades: thermal acclimation and adaptation of cardiac function in a broadly distributed marine invasive species, the European green crab, Carcinus maenas.

    PubMed

    Tepolt, Carolyn K; Somero, George N

    2014-04-01

    As global warming accelerates, there is increasing concern about how ecosystems may change as a result of species loss and replacement. Here, we examined the thermal physiology of the European green crab (Carcinus maenas Linnaeus 1758), a globally invasive species, along three parallel thermal gradients in its native and invasive ranges. At each site, we assessed cardiac physiology to determine heat and cold tolerance and acclimatory plasticity. We found that, overall, the species is highly tolerant of both heat and cold, and that it survives higher temperatures than co-occurring native marine crustaceans. Further, we found that both heat and cold tolerance are plastic in response to short-term acclimation (18-31 days at either 5 or 25°C). Comparing patterns within ranges, we found latitudinal gradients in thermal tolerance in the native European range and in the invasive range in eastern North America. This pattern is strongest in the native range, and likely evolved there. Because of a complicated invasion history, the latitudinal pattern in the eastern North American invasive range may be due either to rapid adaptation post-invasion or to adaptive differences between the ancestral populations that founded the invasion. Overall, the broad thermal tolerance ranges of green crabs, which may facilitate invasion of novel habitats, derive from high inherent eurythermality and acclimatory plasticity and potentially adaptive differentiation among populations. The highly flexible physiology that results from these capacities may represent the hallmark of a successful invasive species, and may provide a model for success in a changing world.

  8. Master of all trades: thermal acclimation and adaptation of cardiac function in a broadly distributed marine invasive species, the European green crab, Carcinus maenas.

    PubMed

    Tepolt, Carolyn K; Somero, George N

    2014-04-01

    As global warming accelerates, there is increasing concern about how ecosystems may change as a result of species loss and replacement. Here, we examined the thermal physiology of the European green crab (Carcinus maenas Linnaeus 1758), a globally invasive species, along three parallel thermal gradients in its native and invasive ranges. At each site, we assessed cardiac physiology to determine heat and cold tolerance and acclimatory plasticity. We found that, overall, the species is highly tolerant of both heat and cold, and that it survives higher temperatures than co-occurring native marine crustaceans. Further, we found that both heat and cold tolerance are plastic in response to short-term acclimation (18-31 days at either 5 or 25°C). Comparing patterns within ranges, we found latitudinal gradients in thermal tolerance in the native European range and in the invasive range in eastern North America. This pattern is strongest in the native range, and likely evolved there. Because of a complicated invasion history, the latitudinal pattern in the eastern North American invasive range may be due either to rapid adaptation post-invasion or to adaptive differences between the ancestral populations that founded the invasion. Overall, the broad thermal tolerance ranges of green crabs, which may facilitate invasion of novel habitats, derive from high inherent eurythermality and acclimatory plasticity and potentially adaptive differentiation among populations. The highly flexible physiology that results from these capacities may represent the hallmark of a successful invasive species, and may provide a model for success in a changing world. PMID:24671964

  9. Biology of invasive termites: a worldwide review.

    PubMed

    Evans, Theodore A; Forschler, Brian T; Grace, J Kenneth

    2013-01-01

    The number of recognized invasive termite species has increased from 17 in 1969 to 28 today. Fourteen species have been added to the list in the past 44 years; 10 have larger distributions and 4 have no reported change in distribution, and 3 species are no longer considered invasive. Although most research has focused on invasive termites in urban areas, molecular identification methods have answered questions about certain species and found that at least six species have invaded natural forest habitats. All invasive species share three characteristics that together increase the probability of creating viable propagules: they eat wood, nest in food, and easily generate secondary reproductives. These characteristics are most common in two families, the Kalotermitidae and Rhinotermitidae (which make up 21 species on the invasive termite list), particularly in three genera, Cryptotermes, Heterotermes, and Coptotermes (which together make up 16 species). Although it is the largest termite family, the Termitidae (comprising 70% of all termite species) have only two invasive species, because relatively few species have these characteristics. Islands have double the number of invasive species that continents do, with islands in the South Pacific the most invaded geographical region. Most invasive species originate from Southeast Asia. The standard control methods normally used against native pest termites are also employed against invasive termites; only two eradication attempts, in South Africa and New Zealand, appear to have been successful, both against Coptotermes species. PMID:23020620

  10. U-Pace: Facilitating Academic Success for All Students

    ERIC Educational Resources Information Center

    Reddy, Diane M.; Fleming, Raymond; Pedrick, Laura E.; Ports, Katie A.; Barnack-Tavlaris, Jessica L.; Helion, Alicia M.; Swain, Rodney A.

    2011-01-01

    Because the transition to a knowledge-based economy requires an educated workforce, colleges and universities have made retention of students--particularly those who are academically underprepared--an institutional priority. College completion leads to economic and social advancement for students and is also critical to the nation's economic and…

  11. Repetition across Successive Sentences Facilitates Young Children's Word Learning

    ERIC Educational Resources Information Center

    Schwab, Jessica F.; Lew-Williams, Casey

    2016-01-01

    Young children who hear more child-directed speech (CDS) tend to have larger vocabularies later in childhood, but the specific characteristics of CDS underlying this link are currently underspecified. The present study sought to elucidate how the structure of language input boosts learning by investigating whether repetition of object labels in…

  12. Examining the Context of Instruction to Facilitate Student Success

    ERIC Educational Resources Information Center

    von der Embse, Nathaniel P.; Putwain, David W.

    2015-01-01

    Identifying effective instructional practices and effective teachers is an important issue in educational research, policy, and practice. However, many schools have resorted to measuring these constructs with student test scores, ignoring the instructional context. In this introductory article to the special issue, we highlight the importance of…

  13. The evolutionary consequences of biological invasions.

    PubMed

    Suarez, Andrew V; Tsutsui, Neil D

    2008-01-01

    A major challenge of invasion biology is the development of a predictive framework that prevents new invasions. This is inherently difficult because different biological characteristics are important at the different stages of invasion: opportunity/transport, establishment and spread. Here, we draw from recent research on a variety of taxa to examine the evolutionary causes and consequences of biological invasions. The process of introduction may favour species with characteristics that promote success in highly disturbed, human-dominated landscapes, thus exerting novel forms of selection on introduced populations. Moreover, evidence is accumulating that multiple introductions can often be critical to the successful establishment and spread of introduced species, as they may be important sources of genetic variation necessary for adaptation in new environments or may permit the introduction of novel traits. Thus, not only should the introduction of new species be prevented, but substantial effort should also be directed to preventing the secondary introduction of previously established species (and even movement of individuals among introduced populations). Modern molecular techniques can take advantage of genetic changes postintroduction to determine the source of introduced populations and their vectors of spread, and to elucidate the mechanisms of success of some invasive species. Moreover, the growing availability of genomic tools will permit the identification of underlying genetic causes of invasive success.

  14. Behavioral flexibility in an invasive bird is independent of other behaviors.

    PubMed

    Logan, Corina J

    2016-01-01

    Behavioral flexibility is considered important for a species to adapt to environmental change. However, it is unclear how behavioral flexibility works: it relates to problem solving ability and speed in unpredictable ways, which leaves an open question of whether behavioral flexibility varies with differences in other behaviors. If present, such correlations would mask which behavior causes individuals to vary. I investigated whether behavioral flexibility (reversal learning) performances were linked with other behaviors in great-tailed grackles, an invasive bird. I found that behavioral flexibility did not significantly correlate with neophobia, exploration, risk aversion, persistence, or motor diversity. This suggests that great-tailed grackle performance in behavioral flexibility tasks reflects a distinct source of individual variation. Maintaining multiple distinct sources of individual variation, and particularly variation in behavioral flexibility, may be a mechanism for coping with the diversity of novel elements in their environments and facilitate this species' invasion success. PMID:27478705

  15. Behavioral flexibility in an invasive bird is independent of other behaviors

    PubMed Central

    2016-01-01

    Behavioral flexibility is considered important for a species to adapt to environmental change. However, it is unclear how behavioral flexibility works: it relates to problem solving ability and speed in unpredictable ways, which leaves an open question of whether behavioral flexibility varies with differences in other behaviors. If present, such correlations would mask which behavior causes individuals to vary. I investigated whether behavioral flexibility (reversal learning) performances were linked with other behaviors in great-tailed grackles, an invasive bird. I found that behavioral flexibility did not significantly correlate with neophobia, exploration, risk aversion, persistence, or motor diversity. This suggests that great-tailed grackle performance in behavioral flexibility tasks reflects a distinct source of individual variation. Maintaining multiple distinct sources of individual variation, and particularly variation in behavioral flexibility, may be a mechanism for coping with the diversity of novel elements in their environments and facilitate this species’ invasion success. PMID:27478705

  16. Characteristics of successful alien plants.

    PubMed

    van Kleunen, M; Dawson, W; Maurel, N

    2015-05-01

    Herbert Baker arguably initiated the search for species characteristics determining alien plant invasion success, with his formulation of the 'ideal weed'. Today, a profusion of studies has tested a myriad of traits for their importance in explaining success of alien plants, but the multiple, not always appropriate, approaches used have led to some confusion and criticism. We argue that a greater understanding of the characteristics explaining alien plant success requires a refined approach that respects the multistage, multiscale nature of the invasion process. We present a schema of questions we can ask regarding the success of alien species, with the answering of one question in the schema being conditional on the answer of preceding questions (thus acknowledging the nested nature of invasion stages). For each question, we identify traits and attributes of species we believe are likely to be most important in explaining species success, and we make predictions as to how we expect successful aliens to differ from natives and from unsuccessful aliens in their characteristics. We organize the findings of empirical studies according to the questions in our schema that they have addressed, to assess the extent to which they support our predictions. We believe that research on plant traits of alien species has already told us a lot about why some alien species become successful after introduction. However, if we ask the right questions at the appropriate scale and use appropriate comparators, research on traits may tell us whether they are really important or not, and if so under which conditions.

  17. Adaptive invasive species distribution models: A framework for modeling incipient invasions

    USGS Publications Warehouse

    Uden, Daniel R.; Allen, Craig R.; Angeler, David G.; Corral, Lucia; Fricke, Kent A.

    2015-01-01

    The utilization of species distribution model(s) (SDM) for approximating, explaining, and predicting changes in species’ geographic locations is increasingly promoted for proactive ecological management. Although frameworks for modeling non-invasive species distributions are relatively well developed, their counterparts for invasive species—which may not be at equilibrium within recipient environments and often exhibit rapid transformations—are lacking. Additionally, adaptive ecological management strategies address the causes and effects of biological invasions and other complex issues in social-ecological systems. We conducted a review of biological invasions, species distribution models, and adaptive practices in ecological management, and developed a framework for adaptive, niche-based, invasive species distribution model (iSDM) development and utilization. This iterative, 10-step framework promotes consistency and transparency in iSDM development, allows for changes in invasive drivers and filters, integrates mechanistic and correlative modeling techniques, balances the avoidance of type 1 and type 2 errors in predictions, encourages the linking of monitoring and management actions, and facilitates incremental improvements in models and management across space, time, and institutional boundaries. These improvements are useful for advancing coordinated invasive species modeling, management and monitoring from local scales to the regional, continental and global scales at which biological invasions occur and harm native ecosystems and economies, as well as for anticipating and responding to biological invasions under continuing global change.

  18. Molecular basis of invasion in breast cancer.

    PubMed

    McSherry, E A; Donatello, S; Hopkins, A M; McDonnell, S

    2007-12-01

    Cancer cell invasion involves the breaching of tissue barriers by cancer cells, and the subsequent infiltration of these cells throughout the surrounding tissue. In breast cancer, invasion at the molecular level requires the coordinated efforts of numerous processes within the cancer cell and its surroundings. Accumulation of genetic changes which impair the regulation of cell growth and death is generally accepted to initiate cancer. Loss of cell-adhesion molecules, resulting in a loss in tissue architecture, in parallel with matrix remodelling may also confer a motile or migratory advantage to breast cancer cells. The tumour microenvironment may further influence the behaviour of these cancer cells through expression of cytokines, growth factors, and proteases promoting chemotaxis and invasion. This review will attempt to summarise recent work on these fundamental processes influencing or facilitating breast cancer cell invasion. (Part of a Multi-author Review). PMID:17957337

  19. Molecular basis of invasion in breast cancer.

    PubMed

    McSherry, E A; Donatello, S; Hopkins, A M; McDonnell, S

    2007-12-01

    Cancer cell invasion involves the breaching of tissue barriers by cancer cells, and the subsequent infiltration of these cells throughout the surrounding tissue. In breast cancer, invasion at the molecular level requires the coordinated efforts of numerous processes within the cancer cell and its surroundings. Accumulation of genetic changes which impair the regulation of cell growth and death is generally accepted to initiate cancer. Loss of cell-adhesion molecules, resulting in a loss in tissue architecture, in parallel with matrix remodelling may also confer a motile or migratory advantage to breast cancer cells. The tumour microenvironment may further influence the behaviour of these cancer cells through expression of cytokines, growth factors, and proteases promoting chemotaxis and invasion. This review will attempt to summarise recent work on these fundamental processes influencing or facilitating breast cancer cell invasion. (Part of a Multi-author Review).

  20. Predator control promotes invasive dominated ecological states.

    PubMed

    Wallach, Arian D; Johnson, Christopher N; Ritchie, Euan G; O'Neill, Adam J

    2010-08-01

    Invasive species are regarded as one of the top five drivers of the global extinction crisis. In response, extreme measures have been applied in an attempt to control or eradicate invasives, with little success overall. We tested the idea that state shifts to invasive dominance are symptomatic of losses in ecosystem resilience, due to the suppression of apex predators. This concept was investigated in Australia where the high rate of mammalian extinctions is largely attributed to the destructive influence of invasive species. Intensive pest control is widely applied across the continent, simultaneously eliminating Australia's apex predator, the dingo (Canis lupus dingo). We show that predator management accounts for shifts between two main ecosystem states. Lethal control fractures dingo social structure and leads to bottom-up driven increases in invasive mesopredators and herbivores. Where control is relaxed, dingoes re-establish top-down regulation of ecosystems, allowing for the recovery of biodiversity and productivity. PMID:20545732

  1. Understanding Facilitation: Theory and Principles.

    ERIC Educational Resources Information Center

    Hogan, Christine

    This book introduces newcomers to the concept of facilitation, and it presents a critical analysis of established and current theory on facilitation for existing practitioners. The following are among the topics discussed: (1) emergence of the field of facilitation; (2) development of facilitation in management; (3) development of facilitation in…

  2. Invasive clonal plant species have a greater root-foraging plasticity than non-invasive ones.

    PubMed

    Keser, Lidewij H; Dawson, Wayne; Song, Yao-Bin; Yu, Fei-Hai; Fischer, Markus; Dong, Ming; van Kleunen, Mark

    2014-03-01

    Clonality is frequently positively correlated with plant invasiveness, but which aspects of clonality make some clonal species more invasive than others is not known. Due to their spreading growth form, clonal plants are likely to experience spatial heterogeneity in nutrient availability. Plasticity in allocation of biomass to clonal growth organs and roots may allow these plants to forage for high-nutrient patches. We investigated whether this foraging response is stronger in species that have become invasive than in species that have not. We used six confamilial pairs of native European clonal plant species differing in invasion success in the USA. We grew all species in large pots under homogeneous or heterogeneous nutrient conditions in a greenhouse, and compared their nutrient-foraging response and performance. Neither invasive nor non-invasive species showed significant foraging responses to heterogeneity in clonal growth organ biomass or in aboveground biomass of clonal offspring. Invasive species had, however, a greater positive foraging response in terms of root and belowground biomass than non-invasive species. Invasive species also produced more total biomass. Our results suggest that the ability for strong root foraging is among the characteristics promoting invasiveness in clonal plants.

  3. Invasive clonal plant species have a greater root-foraging plasticity than non-invasive ones.

    PubMed

    Keser, Lidewij H; Dawson, Wayne; Song, Yao-Bin; Yu, Fei-Hai; Fischer, Markus; Dong, Ming; van Kleunen, Mark

    2014-03-01

    Clonality is frequently positively correlated with plant invasiveness, but which aspects of clonality make some clonal species more invasive than others is not known. Due to their spreading growth form, clonal plants are likely to experience spatial heterogeneity in nutrient availability. Plasticity in allocation of biomass to clonal growth organs and roots may allow these plants to forage for high-nutrient patches. We investigated whether this foraging response is stronger in species that have become invasive than in species that have not. We used six confamilial pairs of native European clonal plant species differing in invasion success in the USA. We grew all species in large pots under homogeneous or heterogeneous nutrient conditions in a greenhouse, and compared their nutrient-foraging response and performance. Neither invasive nor non-invasive species showed significant foraging responses to heterogeneity in clonal growth organ biomass or in aboveground biomass of clonal offspring. Invasive species had, however, a greater positive foraging response in terms of root and belowground biomass than non-invasive species. Invasive species also produced more total biomass. Our results suggest that the ability for strong root foraging is among the characteristics promoting invasiveness in clonal plants. PMID:24352844

  4. Facilitative Strategies in Action.

    ERIC Educational Resources Information Center

    Fuller, Thara M. A.; Haugabrook, Adrian K.

    2001-01-01

    Describes campus-based strategies to facilitate collaboration by examining the process of restructuring a division of student affairs as an educational partner with academic affairs. Describes three collaborative efforts at the University of Massachusetts Boston: the Beacon Leadership Project, the Diversity Research Initiative, and the Beacon…

  5. The Inclusion Facilitator's Guide

    ERIC Educational Resources Information Center

    Jorgensen, Cheryl M.; Schuh, Mary C.; Nisbet, Jan

    2005-01-01

    Inclusion facilitators are educators who do more than teach children with disabilities--they advocate for change in schools and communities, sparking a passion for inclusion in teachers, administrators, and families and giving them the practical guidance they need to make it work. This is an essential new role in today's schools, and this guide…

  6. Facilitating Cognitive Development.

    ERIC Educational Resources Information Center

    Schwebel, Milton

    1985-01-01

    Human cognition research is shifting away from the importance of IQ and is emphasizing the stimulation and acceleration of a child's mental development. The emerging field of instructional psychology is trying to facilitate cognitive development. Current experimental programs--a university-school project in Belgium and a family project in…

  7. Formation of Freirian Facilitators.

    ERIC Educational Resources Information Center

    Noble, Phyllis

    This paper is written for people who are already familiar with the philosophy and methodology of Paulo Freire's liberatory education and are interested in creating a formation program for adult education facilitators using his ideas. The author describes the paper as "a collection of thoughts, of things to consider," when organizing such a…

  8. Facilitating Distance Education.

    ERIC Educational Resources Information Center

    Rossman, Mark H., Ed.; Rossman, Maxine E., Ed.

    1995-01-01

    This collection of articles on distance learning reflects the perspectives and concerns of the learner and the facilitator of learning in distance education setting. Eight chapters are included: (1) "The Evolution and Advantages of Distance Education" (John E. Cantelon) traces the history of distance education and demonstrates how it transcends…

  9. Facilitation of Adult Development

    ERIC Educational Resources Information Center

    Boydell, Tom

    2016-01-01

    Taking an autobiographical approach, I tell the story of my experiences facilitating adult development, in a polytechnic and as a management consultant. I relate these to a developmental framework of Modes of Being and Learning that I created and elaborated with colleagues. I connect this picture with a number of related models, theories,…

  10. Paradigm of plant invasion: multifaceted review on sustainable management.

    PubMed

    Rai, Prabhat Kumar

    2015-12-01

    A cascade of reviews and growing body of literature exists on forest invasion ecology, its mechanism or causes; however, no review addressed the sustainable management of invasive plants of forest in totality. Henceforth, the present paper aims to provide a critical review on the management of invasive species particularly in the context of forest plants. Plant invasion in forest is now increasingly being recognized as a global problem, and various continents are adversely affected, although to a differential scale. Quest for the ecological mechanism lying behind the success of invasive species over native species of forest has drawn the attention of researches worldwide particularly in the context of diversity-stability relationship. Transport, colonization, establishment, and landscape spread may be different steps in success of invasive plants in forest, and each and every step is checked through several ecological attributes. Further, several ecological attribute and hypothesis (enemy release, novel weapon, empty niche, evolution of increased competitive ability, etc.) were proposed pertaining to success of invasive plant species in forest ecosystems. However, a single theory will not be able to account for invasion success among all environments as it may vary spatially and temporally. Therefore, in order to formulate a sustainable management plan for invasive plants of forest, it is necessary to develop a synoptic view of the dynamic processes involved in the invasion process. Moreover, invasive species of forest can act synergistically with other elements of global change, including land-use change, climate change, increased concentrations of atmospheric carbon dioxide, and nitrogen deposition. Henceforth, a unified framework for biological invasions that reconciles and integrates the key features of the most commonly used invasion frameworks into a single conceptual model that can be applied to all human-mediated invasions.

  11. Paradigm of plant invasion: multifaceted review on sustainable management.

    PubMed

    Rai, Prabhat Kumar

    2015-12-01

    A cascade of reviews and growing body of literature exists on forest invasion ecology, its mechanism or causes; however, no review addressed the sustainable management of invasive plants of forest in totality. Henceforth, the present paper aims to provide a critical review on the management of invasive species particularly in the context of forest plants. Plant invasion in forest is now increasingly being recognized as a global problem, and various continents are adversely affected, although to a differential scale. Quest for the ecological mechanism lying behind the success of invasive species over native species of forest has drawn the attention of researches worldwide particularly in the context of diversity-stability relationship. Transport, colonization, establishment, and landscape spread may be different steps in success of invasive plants in forest, and each and every step is checked through several ecological attributes. Further, several ecological attribute and hypothesis (enemy release, novel weapon, empty niche, evolution of increased competitive ability, etc.) were proposed pertaining to success of invasive plant species in forest ecosystems. However, a single theory will not be able to account for invasion success among all environments as it may vary spatially and temporally. Therefore, in order to formulate a sustainable management plan for invasive plants of forest, it is necessary to develop a synoptic view of the dynamic processes involved in the invasion process. Moreover, invasive species of forest can act synergistically with other elements of global change, including land-use change, climate change, increased concentrations of atmospheric carbon dioxide, and nitrogen deposition. Henceforth, a unified framework for biological invasions that reconciles and integrates the key features of the most commonly used invasion frameworks into a single conceptual model that can be applied to all human-mediated invasions. PMID:26581605

  12. Understanding the genetic basis of invasiveness.

    PubMed

    Prentis, Peter J; Pavasovic, Ana

    2013-05-01

    Invasive species provide excellent study systems to evaluate the ecological and evolutionary processes that contribute to the colonization of novel environments. While the ecological processes that contribute to the successful establishment of invasive plants have been studied in detail, investigation of the evolutionary processes involved in successful invasions has only recently received attention. In particular, studies investigating the genomic and gene expression differences between native and introduced populations of invasive species are just beginning and are required if we are to understand how plants become invasive. In the current issue of Molecular Ecology, Hodgins et al. (2013) tackle this unresolved question, by examining gene expression differences between native and introduced populations of annual ragweed, Ambrosia artemisiifolia. The study identifies a number of potential candidate genes based on gene expression differences that may be responsible for the success of annual ragweed in its introduced range. Furthermore, genes involved in stress response are over-represented in the differentially expressed gene set. Future experiments could use functional studies to test whether changes in gene expression at these candidate genes do in fact underlie changes in growth characteristics and reproductive output observed in this and other invasive species. PMID:23738371

  13. Life history trait differentiation and local adaptation in invasive populations of Ambrosia artemisiifolia in China.

    PubMed

    Li, Xiao-Meng; She, Deng-Ying; Zhang, Da-Yong; Liao, Wan-Jin

    2015-03-01

    Local adaptation has been suggested to play an important role in range expansion, particularly among invasive species. However, the extent to which local adaptation affects the success of an invasive species and the factors that contribute to local adaptation are still unclear. This study aimed to investigate a case of population divergence that may have contributed to the local adaptation of invasive populations of Ambrosia artemisiifolia in China. Common garden experiments in seven populations indicated clinal variations along latitudinal gradients, with plants from higher latitudes exhibiting earlier flowering and smaller sizes at flowering. In reciprocal transplant experiments, plants of a northern Beijing origin produced more seeds at their home site than plants of a southern Wuhan origin, and the Wuhan-origin plants had grown taller at flowering than the Beijing-origin plants in Wuhan, which is believed to facilitate pollen dispersal. These results suggest that plants of Beijing origin may be locally adapted through female fitness and plants from Wuhan possibly locally adapted through male fitness. Selection and path analysis suggested that the phenological and growth traits of both populations have been influenced by natural selection and that flowering time has played an important role through its direct and indirect effects on the relative fitness of each individual. This study evidences the life history trait differentiation and local adaptation during range expansion of invasive A. artemisiifolia in China.

  14. A resurrection study reveals rapid adaptive evolution within populations of an invasive plant.

    PubMed

    Sultan, Sonia E; Horgan-Kobelski, Tim; Nichols, Lauren M; Riggs, Charlotte E; Waples, Ryan K

    2013-02-01

    The future spread and impact of an introduced species will depend on how it adapts to the abiotic and biotic conditions encountered in its new range, so the potential for rapid evolution subsequent to species introduction is a critical, evolutionary dimension of invasion biology. Using a resurrection approach, we provide a direct test for change over time within populations in a species' introduced range, in the Asian shade annual Polygonum cespitosum. We document, over an 11-year period, the evolution of increased reproductive output as well as greater physiological and root-allocational plasticity in response to the more open, sunny conditions found in the North American range in which the species has become invasive. These findings show that extremely rapid adaptive modifications to ecologically-important traits and plastic expression patterns can evolve subsequent to a species' introduction, within populations established in its introduced range. This study is one of the first to directly document evolutionary change in adaptive plasticity. Such rapid evolutionary changes can facilitate the spread of introduced species into novel habitats and hence contribute to their invasive success in a new range. The data also reveal how evolutionary trajectories can differ among populations in ways that can influence invasion dynamics.

  15. Attacking invasive grasses

    USGS Publications Warehouse

    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.

  16. Tolerance and resistance of invasive and native Eupatorium species to generalist herbivore insects

    NASA Astrophysics Data System (ADS)

    Wang, Rui-Fang; Feng, Yu-Long

    2016-11-01

    Invasive plants are exotic species that escape control by native specialist enemies. However, exotic plants may still be attacked by locally occurring generalist enemies, which can influence the dynamics of biological invasions. If invasive plants have greater defensive (resistance and tolerance) capabilities than indigenous plants, they may experience less damage from native herbivores. In the present study, we tested this prediction using the invasive plant Eupatorium adenophorum and two native congeners under simulated defoliation and generalist herbivore insect (Helicoverpa armigera and Spodoptera litura) treatments. E. adenophorum was less susceptible and compensated more quickly to damages in biomass production from both treatments compared to its two congeners, exhibiting greater herbivore tolerance. This strong tolerance to damage was associated with greater resource allocation to aboveground structures, leading to a higher leaf area ratio and a lower root: crown mass ratio than those of its native congeners. E. adenophorum also displayed a higher resistance index (which integrates acid detergent fiber, nitrogen content, carbon/nitrogen ratio, leaf mass per area, toughness, and trichome density) than its two congeners. Thus, H. armigera and S. litura performed poorly on E. adenophorum, with less leaf damage, a lengthened insect developmental duration, and decreased pupating: molting ratios compared to those of the native congeners. Strong tolerance and resistance traits may facilitate the successful invasion of E. adenophorum in China and may decrease the efficacy of leaf-feeding biocontrol agents. Our results highlight both the need for further research on defensive traits and their role in the invasiveness and biological control of exotic plants, and suggest that biocontrol of E. adenophorum in China would require damage to the plant far in excess of current levels.

  17. Best practice in clinical facilitation of undergraduate nursing students.

    PubMed

    Needham, Judith; McMurray, Anne; Shaban, Ramon Z

    2016-09-01

    Clinical facilitation is critical to successful student clinical experience. The research reported in this paper used an interpretive case study to explore perspectives of clinical facilitators on what constitutes best practice in clinical facilitation of undergraduate nursing students. Eleven clinical facilitators from South East Queensland, Australia, participated in focus groups, interviews and a concept mapping exercise to gather their perspectives on best practice. The data gathered information regarding their prior and current experiences as registered nurses and facilitators, considering reasons they became clinical facilitators, their educational background and self-perceived adequacy of their knowledge for clinical facilitation. Analysis was through constant comparison. Findings of the study provided in-depth insight into the role of clinical facilitators, with best practice conceptualised via three main themes; 'assessing', 'learning to facilitate' and 'facilitating effectively'. While they felt there was some autonomy in the role, the clinical facilitators sought a closer liaison with academic staff and feedback about their performance, in particular their assessment of the students. Key strategies identified for improving best practice included educational support for the clinical facilitators, networking, and mentoring from more experienced clinical facilitators. When implemented, these strategies will help develop the clinical facilitators' skills and ensure quality clinical experiences for undergraduate nursing students. PMID:27580169

  18. The evolution of invasiveness in garden ants.

    PubMed

    Cremer, Sylvia; Ugelvig, Line V; Drijfhout, Falko P; Schlick-Steiner, Birgit C; Steiner, Florian M; Seifert, Bernhard; Hughes, David P; Schulz, Andreas; Petersen, Klaus S; Konrad, Heino; Stauffer, Christian; Kiran, Kadri; Espadaler, Xavier; d'Ettorre, Patrizia; Aktaç, Nihat; Eilenberg, Jørgen; Jones, Graeme R; Nash, David R; Pedersen, Jes S; Boomsma, Jacobus J

    2008-01-01

    It is unclear why some species become successful invaders whilst others fail, and whether invasive success depends on pre-adaptations already present in the native range or on characters evolving de-novo after introduction. Ants are among the worst invasive pests, with Lasius neglectus and its rapid spread through Europe and Asia as the most recent example of a pest ant that may become a global problem. Here, we present the first integrated study on behavior, morphology, population genetics, chemical recognition and parasite load of L. neglectus and its non-invasive sister species L. turcicus. We find that L. neglectus expresses the same supercolonial syndrome as other invasive ants, a social system that is characterized by mating without dispersal and large networks of cooperating nests rather than smaller mutually hostile colonies. We conclude that the invasive success of L. neglectus relies on a combination of parasite-release following introduction and pre-adaptations in mating system, body-size, queen number and recognition efficiency that evolved long before introduction. Our results challenge the notion that supercolonial organization is an inevitable consequence of low genetic variation for chemical recognition cues in small invasive founder populations. We infer that low variation and limited volatility in cuticular hydrocarbon profiles already existed in the native range in combination with low dispersal and a highly viscous population structure. Human transport to relatively disturbed urban areas thus became the decisive factor to induce parasite release, a well established general promoter of invasiveness in non-social animals and plants, but understudied in invasive social insects. PMID:19050762

  19. The Evolution of Invasiveness in Garden Ants

    PubMed Central

    Cremer, Sylvia; Ugelvig, Line V.; Drijfhout, Falko P.; Schlick-Steiner, Birgit C.; Steiner, Florian M.; Seifert, Bernhard; Hughes, David P.; Schulz, Andreas; Petersen, Klaus S.; Konrad, Heino; Stauffer, Christian; Kiran, Kadri; Espadaler, Xavier; d'Ettorre, Patrizia; Aktaç, Nihat; Eilenberg, Jørgen; Jones, Graeme R.; Nash, David R.; Pedersen, Jes S.; Boomsma, Jacobus J.

    2008-01-01

    It is unclear why some species become successful invaders whilst others fail, and whether invasive success depends on pre-adaptations already present in the native range or on characters evolving de-novo after introduction. Ants are among the worst invasive pests, with Lasius neglectus and its rapid spread through Europe and Asia as the most recent example of a pest ant that may become a global problem. Here, we present the first integrated study on behavior, morphology, population genetics, chemical recognition and parasite load of L. neglectus and its non-invasive sister species L. turcicus. We find that L. neglectus expresses the same supercolonial syndrome as other invasive ants, a social system that is characterized by mating without dispersal and large networks of cooperating nests rather than smaller mutually hostile colonies. We conclude that the invasive success of L. neglectus relies on a combination of parasite-release following introduction and pre-adaptations in mating system, body-size, queen number and recognition efficiency that evolved long before introduction. Our results challenge the notion that supercolonial organization is an inevitable consequence of low genetic variation for chemical recognition cues in small invasive founder populations. We infer that low variation and limited volatility in cuticular hydrocarbon profiles already existed in the native range in combination with low dispersal and a highly viscous population structure. Human transport to relatively disturbed urban areas thus became the decisive factor to induce parasite release, a well established general promoter of invasiveness in non-social animals and plants, but understudied in invasive social insects. PMID:19050762

  20. Loss of reproductive output caused by an invasive species.

    PubMed

    Tremblay, Maude E M; Morris, Todd J; Ackerman, Josef D

    2016-04-01

    We investigated whether Neogobius melanostomus, an invader of biodiversity 'hot-spots' in the Laurentian Great Lakes region, facilitates or inhibits unionid mussel recruitment by serving as a host or sink for their parasitic larvae (glochidia). Infestation and metamorphosis rates of four mussel species with at-risk (conservation) status (Epioblasma torulosa rangiana, Epioblasma triquetra, Lampsilis fasciola and Villosa iris) and one common species (Actinonaias ligamentina) on N. melanostomus were compared with rates on known primary and marginal hosts in the laboratory. All species successfully infested N. melanostomus, but only E. triquetra, V. iris and A. ligamentina successfully metamorphosed into juveniles, albeit at very low rates well below those seen on even the marginal hosts. Neogobius melanostomus collected from areas of unionid occurrence in the Grand and Sydenham rivers (Ontario, Canada) exhibited glochidial infection rates of 39.4% and 5.1%, respectively, with up to 30 glochidia representing as many as six unionid species per fish. A mathematical model suggests that N. melanostomus serve more as a sink for glochidia than as a host for unionids, thereby limiting recruitment success. This represents a novel method by which an invasive species affects a native species.

  1. Loss of reproductive output caused by an invasive species

    PubMed Central

    Tremblay, Maude E. M.; Morris, Todd J.; Ackerman, Josef D.

    2016-01-01

    We investigated whether Neogobius melanostomus, an invader of biodiversity ‘hot-spots’ in the Laurentian Great Lakes region, facilitates or inhibits unionid mussel recruitment by serving as a host or sink for their parasitic larvae (glochidia). Infestation and metamorphosis rates of four mussel species with at-risk (conservation) status (Epioblasma torulosa rangiana, Epioblasma triquetra, Lampsilis fasciola and Villosa iris) and one common species (Actinonaias ligamentina) on N. melanostomus were compared with rates on known primary and marginal hosts in the laboratory. All species successfully infested N. melanostomus, but only E. triquetra, V. iris and A. ligamentina successfully metamorphosed into juveniles, albeit at very low rates well below those seen on even the marginal hosts. Neogobius melanostomus collected from areas of unionid occurrence in the Grand and Sydenham rivers (Ontario, Canada) exhibited glochidial infection rates of 39.4% and 5.1%, respectively, with up to 30 glochidia representing as many as six unionid species per fish. A mathematical model suggests that N. melanostomus serve more as a sink for glochidia than as a host for unionids, thereby limiting recruitment success. This represents a novel method by which an invasive species affects a native species. PMID:27152202

  2. Invasive Insects Differ from Non-Invasive in Their Thermal Requirements

    PubMed Central

    Kenis, Marc; Honěk, Alois; Skuhrovec, Jiří; Pyšek, Petr

    2015-01-01

    We tested whether two basic thermal requirements for insect development, lower developmental thresholds, i.e. temperatures at which development ceases, and sums of effective temperatures, i.e. numbers of day degrees above the lower developmental thresholds necessary to complete development, differ among insect species that proved to be successful invaders in regions outside their native range and those that did not. Focusing on species traits underlying invasiveness that are related to temperature provides insights into the mechanisms of insect invasions. The screening of thermal requirements thus could improve risk-assessment schemes by incorporating these traits in predictions of potentially invasive insect species. We compared 100 pairs of taxonomically-related species originating from the same continent, one invasive and the other not reported as invasive. Invasive species have higher lower developmental thresholds than those never recorded outside their native ranges. Invasive species also have a lower sum of effective temperatures, though not significantly. However, the differences between invasive and non-invasive species in the two physiological measures were significantly inversely correlated. This result suggests that many species are currently prevented from invading by low temperatures in some parts of the world. Those species that will overcome current climatic constraints in regions outside their native distribution due to climate change could become even more serious future invaders than present-day species, due to their potentially faster development. PMID:26090826

  3. Capitol Success.

    PubMed

    Sorrel, Amy Lynn

    2015-08-01

    This legislative session, medicine resolved to ensure physicians can give their patients the best care possible. The hard work paid off in significant victories that largely build on the Texas Medical Association's 2013 legislative successes. PMID:26263520

  4. Capitol Success.

    PubMed

    Sorrel, Amy Lynn

    2015-08-01

    This legislative session, medicine resolved to ensure physicians can give their patients the best care possible. The hard work paid off in significant victories that largely build on the Texas Medical Association's 2013 legislative successes.

  5. Facilitation as a teaching strategy : experiences of facilitators.

    PubMed

    Lekalakala-Mokgele, E

    2006-08-01

    Changes in nursing education involve the move from traditional teaching approaches that are teacher-centred to facilitation, a student centred approach. The student-centred approach is based on a philosophy of teaching and learning that puts the learner on centre-stage. The aim of this study was to identify the challenges of facilitators of learning using facilitation as a teaching method and recommend strategies for their (facilitators) development and support. A qualitative, explorative and contextual design was used. Four (4) universities in South Africa which utilize facilitation as a teaching/ learning process were identified and the facilitators were selected to be the sample of the study. The main question posed during in-depth group interviews was: How do you experience facilitation as a teaching/learning method?. Facilitators indicated different experiences and emotions when they first had to facilitate learning. All of them indicated that it was difficult to facilitate at the beginning as they were trained to lecture and that no format for facilitation was available. They experienced frustrations and anxieties as a result. The lack of knowledge of facilitation instilled fear in them. However they indicated that facilitation had many benefits for them and for the students. Amongst the ones mentioned were personal and professional growth. Challenges mentioned were the fear that they waste time and that they do not cover the content. It is therefore important that facilitation be included in the training of nurse educators. PMID:17131610

  6. Fort Collins Science Center: Invasive Species Science

    USGS Publications Warehouse

    Stohlgren, Tom

    2004-01-01

    FORT is also the administrative home of the National Institute of Invasive Species Science, a growing consortium of partnerships between government and private organizations established by the U.S. Geological Survey (USGS) and its many cooperators. The Institute was formed to develop cooperative approaches for invasive species science that meet the urgent needs of land managers and the public. Its mission is to work with others to coordinate data and research from many sources to predict and reduce the effects of harmful nonnative plants, animals, and diseases in natural areas and throughout the United States, with a strategic approach to information management, research, modeling, technical assistance, and outreach. The Institute research team will develop local-, regional-, and national- scale maps of invasive species and identify priority invasive species, vulnerable habitats, and pathways of invasion. County-level and point data on occurrence will be linked to plot-level and site-level information on species abundance and spread. FORT scientists and Institute partners are working to integrate remote sensing data and GIS-based predictive models to track the spread of invasive species across the country. This information will be linked to control and restoration efforts to evaluate their cost-effectiveness. Understanding both successes and failures will advance the science of invasive species containment and control as well as restoration of habitats and native biodiversity.

  7. Invasion strategies in clonal aquatic plants: are phenotypic differences caused by phenotypic plasticity or local adaptation?

    PubMed Central

    Riis, Tenna; Lambertini, Carla; Olesen, Birgit; Clayton, John S.; Brix, Hans; Sorrell, Brian K.

    2010-01-01

    Background and Aims The successful spread of invasive plants in new environments is often linked to multiple introductions and a diverse gene pool that facilitates local adaptation to variable environmental conditions. For clonal plants, however, phenotypic plasticity may be equally important. Here the primary adaptive strategy in three non-native, clonally reproducing macrophytes (Egeria densa, Elodea canadensis and Lagarosiphon major) in New Zealand freshwaters were examined and an attempt was made to link observed differences in plant morphology to local variation in habitat conditions. Methods Field populations with a large phenotypic variety were sampled in a range of lakes and streams with different chemical and physical properties. The phenotypic plasticity of the species before and after cultivation was studied in a common garden growth experiment, and the genetic diversity of these same populations was also quantified. Key Results For all three species, greater variation in plant characteristics was found before they were grown in standardized conditions. Moreover, field populations displayed remarkably little genetic variation and there was little interaction between habitat conditions and plant morphological characteristics. Conclusions The results indicate that at the current stage of spread into New Zealand, the primary adaptive strategy of these three invasive macrophytes is phenotypic plasticity. However, while limited, the possibility that genetic diversity between populations may facilitate ecotypic differentiation in the future cannot be excluded. These results thus indicate that invasive clonal aquatic plants adapt to new introduced areas by phenotypic plasticity. Inorganic carbon, nitrogen and phosphorous were important in controlling plant size of E. canadensis and L. major, but no other relationships between plant characteristics and habitat conditions were apparent. This implies that within-species differences in plant size can be explained

  8. Human and rat glioma growth, invasion, and vascularization in a novel chick embryo brain tumor model.

    PubMed

    Cretu, Alexandra; Fotos, Joseph S; Little, Brian W; Galileo, Deni S

    2005-01-01

    The mechanisms that control the insidiously invasive nature of malignant gliomas are poorly understood, and their study would be facilitated by an in vivo model that is easy to manipulate and inexpensive. The developing chick embryo brain was assessed as a new xenograft model for the production, growth, and study of human and rat glioma cell lines. Three established glioma lines (U-87 MG, C6, and 9L) were injected into chick embryo brain ventricles on embryonic day (E) 5 and brains were examined after several days to two weeks after injection. All glioma lines survived, produced vascularized intraventricular tumors, and invaded the brain in a manner similar to that in rodents. Rat C6 glioma cells spread along vasculature and also invaded the neural tissue. Human U-87 glioma cells migrated along vasculature and exhibited slight invasion of neural tissue. Rat 9L gliosarcoma cells were highly motile, but migrated only along the vasculature. A derivative of 9L cells that stably expressed the cell surface adhesion molecule NgCAM/L1 was produced and also injected into chick embryo brain ventricles to see if this protein could facilitate tumor cell migration away from the vasculature into areas such as axonal tracts. 9L/NgCAM cells, however, did not migrate away from the vasculature and, thus, this protein alone cannot be responsible for diffuse invasiveness of some gliomas. 9L/NgCAM cell motility was assessed in vitro using sophisticated time-lapse microscopy and quantitative analysis, and was significantly altered compared to parental 9L cells. These studies demonstrate that the chick embryo brain is a successful and novel xenograft model for mammalian gliomas and demonstrate the potential usefulness of this new model for studying glioma tumor cell growth, vascularization, and invasiveness.

  9. Partnership Successes

    NASA Technical Reports Server (NTRS)

    2004-01-01

    As NASA plots new courses to fulfill its bold, new mission to explore the Moon, Mars, and beyond, the Agency continues to hold steadfast in its commitment to explore and improve our very own home planet. In doing so, NASA fervidly goes to great lengths to draw correlations between the "know-how" of its many scientists, engineers, and other technology facilitators, and the "know-how" of Federal agency counterparts, academic institutions, and private organizations. By sharing knowledge and resources, these entities come together to find the common ground necessary to preserve the past, present, and future of Earth - in the best interests of all of its inhabitants.

  10. Promoting Spontaneous Facilitation in Online Discussions: Designing Object and Ground Rules

    ERIC Educational Resources Information Center

    Wang, Yu-mei; Chen, Der-Thanq

    2010-01-01

    Facilitation is a key factor in ensuring the success of class discussions. Traditionally, instructors are the ones who assume the role of facilitators in discussions. Online learning environments open opportunities for students to assume the role of facilitators. In well-designed online learning communities, spontaneous facilitation would likely…

  11. Success Counseling.

    ERIC Educational Resources Information Center

    Boffey, D. Barnes; Boffey, David M.

    1993-01-01

    Describes success counseling, a counseling approach based on the principles of William Glasser's control theory and reality therapy that helps campers examine their wants and needs, evaluate their own behaviors, and see the connections between behavior and the ability to meet basic needs for love, power, fun, and freedom. Provides examples of…

  12. Do invasive species perform better in their new ranges?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A fundamental assumption in invasion biology is that successful invaders exhibit enhanced vigor following introductions to new ranges, including larger size, greater fecundity, and denser populations. This assumption of ‘increased vigour’ underlies most empirical and theoretical studies of invasion ...

  13. Ancestral origins and invasion pathways in a globally invasive bird correlate with climate and influences from bird trade.

    PubMed

    Jackson, Hazel; Strubbe, Diederik; Tollington, Simon; Prys-Jones, Robert; Matthysen, Erik; Groombridge, Jim J

    2015-08-01

    Invasive species present a major threat to global biodiversity. Understanding genetic patterns and evolutionary processes that reinforce successful establishment is paramount for elucidating mechanisms underlying biological invasions. Among birds, the ring-necked parakeet (Psittacula krameri) is one of the most successful invasive species, established in over 35 countries. However, little is known about the evolutionary genetic origins of this species and what population genetic signatures tell us about patterns of invasion. We reveal the ancestral origins of populations across the invasive range and explore the potential influence of climate and propagule pressure from the pet trade on observed genetic patterns. Ring-necked parakeet samples representing the ancestral native range (n = 96) were collected from museum specimens, and modern samples from the invasive range (n = 855) were gathered from across Europe, Mauritius and Seychelles, and sequenced for two mitochondrial DNA markers comprising 868 bp of cytochrome b and control region, and genotyped at 10 microsatellite loci. Invasive populations comprise birds that originate predominantly from Pakistan and northern areas of India. Haplotypes associated with more northerly distribution limits in the ancestral native range were more prevalent in invasive populations in Europe, and the predominance of Asian haplotypes in Europe is consistent with the higher number of Asian birds transported by the pet trade outside the native range. Successful establishment of invasive species is likely to be underpinned by a combination of environmental and anthropogenic influences.

  14. Ancestral origins and invasion pathways in a globally invasive bird correlate with climate and influences from bird trade.

    PubMed

    Jackson, Hazel; Strubbe, Diederik; Tollington, Simon; Prys-Jones, Robert; Matthysen, Erik; Groombridge, Jim J

    2015-08-01

    Invasive species present a major threat to global biodiversity. Understanding genetic patterns and evolutionary processes that reinforce successful establishment is paramount for elucidating mechanisms underlying biological invasions. Among birds, the ring-necked parakeet (Psittacula krameri) is one of the most successful invasive species, established in over 35 countries. However, little is known about the evolutionary genetic origins of this species and what population genetic signatures tell us about patterns of invasion. We reveal the ancestral origins of populations across the invasive range and explore the potential influence of climate and propagule pressure from the pet trade on observed genetic patterns. Ring-necked parakeet samples representing the ancestral native range (n = 96) were collected from museum specimens, and modern samples from the invasive range (n = 855) were gathered from across Europe, Mauritius and Seychelles, and sequenced for two mitochondrial DNA markers comprising 868 bp of cytochrome b and control region, and genotyped at 10 microsatellite loci. Invasive populations comprise birds that originate predominantly from Pakistan and northern areas of India. Haplotypes associated with more northerly distribution limits in the ancestral native range were more prevalent in invasive populations in Europe, and the predominance of Asian haplotypes in Europe is consistent with the higher number of Asian birds transported by the pet trade outside the native range. Successful establishment of invasive species is likely to be underpinned by a combination of environmental and anthropogenic influences. PMID:26172573

  15. Ancestral origins and invasion pathways in a globally invasive bird correlate with climate and influences from bird trade

    PubMed Central

    Jackson, Hazel; Strubbe, Diederik; Tollington, Simon; Prys-Jones, Robert; Matthysen, Erik; Groombridge, Jim J

    2015-01-01

    Invasive species present a major threat to global biodiversity. Understanding genetic patterns and evolutionary processes that reinforce successful establishment is paramount for elucidating mechanisms underlying biological invasions. Among birds, the ring-necked parakeet (Psittacula krameri) is one of the most successful invasive species, established in over 35 countries. However, little is known about the evolutionary genetic origins of this species and what population genetic signatures tell us about patterns of invasion. We reveal the ancestral origins of populations across the invasive range and explore the potential influence of climate and propagule pressure from the pet trade on observed genetic patterns. Ring-necked parakeet samples representing the ancestral native range (n = 96) were collected from museum specimens, and modern samples from the invasive range (n = 855) were gathered from across Europe, Mauritius and Seychelles, and sequenced for two mitochondrial DNA markers comprising 868 bp of cytochrome b and control region, and genotyped at 10 microsatellite loci. Invasive populations comprise birds that originate predominantly from Pakistan and northern areas of India. Haplotypes associated with more northerly distribution limits in the ancestral native range were more prevalent in invasive populations in Europe, and the predominance of Asian haplotypes in Europe is consistent with the higher number of Asian birds transported by the pet trade outside the native range. Successful establishment of invasive species is likely to be underpinned by a combination of environmental and anthropogenic influences. PMID:26172573

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

    PubMed

    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

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

    PubMed Central

    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

  18. A facilitated mentoring process for engineers

    SciTech Connect

    Donald, L.; Clark, M.

    1993-11-01

    Mentoring has been occurring in organizations for many, many years through a natural pairing process of people wanting to help one another. The numerous benefits of mentoring to both the protege and the mentor are widely known. In this paper we describe a Facilitated Mentoring Pilot Program for engineers, successfully completed in June, 1993. This career development tool can help make ``Every Engineer a Leader.``

  19. Remote analysis of biological invasion and the impact of enemy release.

    PubMed

    Kellner, James R; Asner, Gregory P; Kinney, Kealoha M; Loarie, Scott R; Knapp, David E; Kennedy-Bowdoin, Ty; Questad, Erin J; Cordell, Susan; Thaxton, Jarrod M

    2011-09-01

    Escape from natural enemies is a widely held generalization for the success of exotic plants. We conducted a large-scale experiment in Hawaii (USA) to quantify impacts of ungulate removal on plant growth and performance, and to test whether elimination of an exotic generalist herbivore facilitated exotic success. Assessment of impacted and control sites before and after ungulate exclusion using airborne imaging spectroscopy and LiDAR, time series satellite observations, and ground-based field studies over nine years indicated that removal of generalist herbivores facilitated exotic success, but the abundance of native species was unchanged. Vegetation cover <1 m in height increased in ungulate-free areas from 48.7% +/- 1.5% to 74.3% +/- 1.8% over 8.4 years, corresponding to an annualized growth rate of lambda = 1.05 +/- 0.01 yr(-1) (median +/- SD). Most of the change was attributable to exotic plant species, which increased from 24.4% +/- 1.4% to 49.1% +/- 2.0%, (lambda = 1.08 +/- 0.01 yr(-1)). Native plants experienced no significant change in cover (23.0% +/- 1.3% to 24.2% +/- 1.8%, lambda = 1.01 +/- 0.01 yr(-1)). Time series of satellite phenology were indistinguishable between the treatment and a 3.0-km2 control site for four years prior to ungulate removal, but they diverged immediately following exclusion of ungulates. Comparison of monthly EVI means before and after ungulate exclusion and between the managed and control areas indicates that EVI strongly increased in the managed area after ungulate exclusion. Field studies and airborne analyses show that the dominant invader was Senecio madagascariensis, an invasive annual forb that increased from < 0.01% to 14.7% fractional cover in ungulate-free areas (lambda = 1.89 +/- 0.34 yr(-1)), but which was nearly absent from the control site. A combination of canopy LAI, water, and fractional cover were expressed in satellite EVI time series and indicate that the invaded region maintained greenness during drought

  20. Minimally Invasive Mitral Valve Surgery III

    PubMed Central

    Lehr, Eric J.; Guy, T. Sloane; Smith, Robert L.; Grossi, Eugene A.; Shemin, Richard J.; Rodriguez, Evelio; Ailawadi, Gorav; Agnihotri, Arvind K.; Fayers, Trevor M.; Hargrove, W. Clark; Hummel, Brian W.; Khan, Junaid H.; Malaisrie, S. Chris; Mehall, John R.; Murphy, Douglas A.; Ryan, William H.; Salemi, Arash; Segurola, Romualdo J.; Smith, J. Michael; Wolfe, J. Alan; Weldner, Paul W.; Barnhart, Glenn R.; Goldman, Scott M.; Lewis, Clifton T. P.

    2016-01-01

    Abstract Minimally invasive mitral valve operations are increasingly common in the United States, but robotic-assisted approaches have not been widely adopted for a variety of reasons. This expert opinion reviews the state of the art and defines best practices, training, and techniques for developing a successful robotics program. PMID:27662478

  1. Invisible invaders: non-pathogenic invasive microbes in aquatic and terrestrial ecosystems.

    PubMed

    Litchman, Elena

    2010-12-01

    Although the number of studies on invasive plants and animals has risen exponentially, little is known about invasive microbes, especially non-pathogenic ones. Microbial invasions by viruses, bacteria, fungi and protists occur worldwide but are much harder to detect than invasions by macroorganisms. Invasive microbes have the potential to significantly alter community structure and ecosystem functioning in diverse terrestrial and aquatic ecosystems. Consequently, increased attention is needed on non-pathogenic invasive microbes, both free-living and symbiotic, and their impacts on communities and ecosystems. Major unknowns include the characteristics that make microbes invasive and properties of the resident communities and the environment that facilitate invasions. A comparison of microbial invasions with invasions of macroorganisms should provide valuable insights into general principles that apply to invasions across all domains of life and to taxon-specific invasion patterns. Invasive microbes appear to possess traits thought to be common in many invasive macroorganisms: high growth rate and resource utilization efficiency, and superior competitive abilities. Invading microorganisms are often similar to native species, but with enhanced performance traits, and tend to spread in lower diversity communities. Global change can exacerbate microbial invasions; therefore, they will likely increase in the future.

  2. The Transition Experiences of Successful Chinese Immigrants

    ERIC Educational Resources Information Center

    Amundson, Norman E.; Yeung, Thomas; Sun, Iris; Chan, Keith; Cheng, Johnny

    2011-01-01

    This article focused on the transition experiences of 20 successful Chinese immigrants, in particular their transition stories and how they accounted for their success (what facilitated and hindered their transition). An enhanced critical incident method was used for data analysis. Four major success categories emerged: having a positive attitude…

  3. Student Success: Institutional and Individual Perspectives

    ERIC Educational Resources Information Center

    Mullin, Christopher M.

    2012-01-01

    This article examines measures of student success, with a focus on how they apply to community colleges. A conceptual framework is presented as a way of facilitating thinking about and accurately grounding discussions of student success. The article closes with an examination of emerging concepts related to the measurement of student success in…

  4. Innovative design for early detection of invasive species

    EPA Science Inventory

    Non-native aquatic species impose significant ecological impacts and rising financial costs in marine and freshwater ecosystems worldwide. Early detection of invasive species, as they enter a vulnerable ecosystem, is critical to successful containment and eradication. ORD, at t...

  5. Linking a Large-Watershed Hydrogeochemical Model to a Wetland Community-Ecosystem Model to Estimate Plant Invasion Risk in the Coastal Great Lakes Region, USA

    NASA Astrophysics Data System (ADS)

    Currie, W. S.; Bourgeau-Chavez, L. L.; Elgersma, K. J.; French, N. H. F.; Goldberg, D. E.; Hart, S.; Hyndman, D. W.; Kendall, A. D.; Martin, S. L.; Martina, J. P.

    2014-12-01

    In the Laurentian Great Lakes region of the Upper Midwest, USA, agricultural and urban land uses together with high N deposition are contributing to elevated flows of N in rivers and groundwater to coastal wetlands. The functioning of coastal wetlands, which provide a vital link between land and water, are imperative to maintaining the health of the entire Great Lakes Basin. Elevated N inflows are believed to facilitate the spread of large-stature invasive plants (cattails and Phragmites) that reduce biodiversity and have complex effects on other ecosystem services including wetland N retention and C accretion. We enhanced the ILHM (Integrated Landscape Hydrology Model) to simulate the effects of land use on N flows in streams, rivers, and groundwater throughout the Lower Peninsula of Michigan. We used the hydroperiods and N loading rates simulated by ILHM as inputs to the Mondrian model of wetland community-ecosystem processes to estimate invasion risk and other ecosystem services in coastal wetlands around the Michigan coast. Our linked models produced threshold behavior in the success of invasive plants in response to N loading, with the threshold ranging from ca. 8 to 12 g N/m2 y, depending on hydroperiod. Plant invasions increased wetland productivity 3-fold over historically oligotrophic native communities, decreased biodiversity but slightly increased wetland N retention. Regardless of invasion, elevated N loading resulted in significantly enhanced rates of C accretion, providing an important region-wide mechanism of C storage. The linked models predicted a general pattern of greater invasion risk in the southern basins of lakes Michigan and Huron relative to northern areas. The basic mechanisms of invasion have been partially validated in our field mesocosms constructed for this project. The general regional patterns of increased invasion risk have been validated through our field campaigns and remote sensing conducted for this project.

  6. Hierarchical modeling of an invasive spread: The eurasian collared-dove streptopelia decaocto in the United States

    USGS Publications Warehouse

    Bled, F.; Royle, J. Andrew; Cam, E.

    2011-01-01

    Invasive species are regularly claimed as the second threat to biodiversity. To apply a relevant response to the potential consequences associated with invasions (e.g., emphasize management efforts to prevent new colonization or to eradicate the species in places where it has already settled), it is essential to understand invasion mechanisms and dynamics. Quantifying and understanding what influences rates of spatial spread is a key research area for invasion theory. In this paper, we develop a model to account for occupancy dynamics of an invasive species. Our model extends existing models to accommodate several elements of invasive processes; we chose the framework of hierarchical modeling to assess site occupancy status during an invasion. First, we explicitly accounted for spatial structure and how distance among sites and position relative to one another affect the invasion spread. In particular, we accounted for the possibility of directional propagation and provided a way of estimating the direction of this possible spread. Second, we considered the influence of local density on site occupancy. Third, we decided to split the colonization process into two subprocesses, initial colonization and recolonization, which may be ground-breaking because these subprocesses may exhibit different relationships with environmental variations (such as density variation) or colonization history (e.g., initial colonization might facilitate further colonization events). Finally, our model incorporates imperfection in detection, which might be a source of substantial bias in estimating population parameters. We focused on the case of the Eurasian Collared-Dove (Streptopelia decaocto) and its invasion of the United States since its introduction in the early 1980s, using data from the North American BBS (Breeding Bird Survey). The Eurasian Collared-Dove is one of the most successful invasive species, at least among terrestrial vertebrates. Our model provided estimation of the

  7. "Success"ful Reading Instruction.

    ERIC Educational Resources Information Center

    George, Carol J.

    1986-01-01

    The Success in Reading and Writing Program at a K-2 school in Fort Jackson, South Carolina, teaches children of varied races and abilities to read and write using newspapers, dictionaries, library books, magazines, and telephone directories. These materials help students develop language skills in a failure-free atmosphere. Includes two…

  8. Facilitating post traumatic growth

    PubMed Central

    Turner, de Sales; Cox, Helen

    2004-01-01

    Background Whilst negative responses to traumatic injury have been well documented in the literature, there is a small but growing body of work that identifies posttraumatic growth as a salient feature of this experience. We contribute to this discourse by reporting on the experiences of 13 individuals who were traumatically injured, had undergone extensive rehabilitation and were discharged from formal care. All participants were injured through involvement in a motor vehicle accident, with the exception of one, who was injured through falling off the roof of a house. Methods In this qualitative study, we used an audio-taped in-depth interview with each participant as the means of data collection. Interviews were transcribed verbatim and analysed thematically to determine the participants' unique perspectives on the experience of recovery from traumatic injury. In reporting the findings, all participants' were given a pseudonym to assure their anonymity. Results Most participants indicated that their involvement in a traumatic occurrence was a springboard for growth that enabled them to develop new perspectives on life and living. Conclusion There are a number of contributions that health providers may make to the recovery of individuals who have been traumatically injured to assist them to develop new views of vulnerability and strength, make changes in relationships, and facilitate philosophical, physical and spiritual growth. PMID:15248894

  9. Endemic predators, invasive prey and native diversity

    PubMed Central

    Wanger, Thomas C.; Wielgoss, Arno C.; Motzke, Iris; Clough, Yann; Brook, Barry W.; Sodhi, Navjot S.; Tscharntke, Teja

    2011-01-01

    Interactions between native diversity and invasive species can be more complex than is currently understood. Invasive ant species often substantially reduce diversity in the native ants diversity that act as natural control agents for pest insects. In Indonesia (on the island of Sulawesi), the third largest cacao producer worldwide, we show that a predatory endemic toad (Ingerophrynus celebensis) controls invasive ant (Anoplolepis gracilipes) abundance, and positively affects native ant diversity. We call this the invasive-naivety effect (an opposite of enemy release), whereby alien species may not harbour anti-predatory defences against a novel native predator. A positive effect of the toads on native ants may facilitate their predation on insect vectors of cacao diseases. Hence, toads may increase crop yield, but further research is needed on this aspect. Ironically, amphibians are globally the most threatened vertebrate class and are strongly impacted by the conversion of rainforest to cacao plantations in Sulawesi. It is, therefore, crucial to manage cacao plantations to maintain these endemic toads, as they may provide critical ecosystem services, such as invasion resistance and preservation of native insect diversity. PMID:20826488

  10. Online: The Student Success Network.

    ERIC Educational Resources Information Center

    Griffin, Robert

    2000-01-01

    The Foothill-De Anza Community College District has digitalized student transcripts, and will create a Student Success Network (SSN) that will provide (1) online Individual Educational Plans for students; (2) electronic student portfolios to facilitate early identification of "at risk" students; and (3) a Counselor Web Portal for online advising.…

  11. Minimally Invasive Surgery in Gynecologic Oncology

    PubMed Central

    Mori, Kristina M.; Neubauer, Nikki L.

    2013-01-01

    Minimally invasive surgery has been utilized in the field of obstetrics and gynecology as far back as the 1940s when culdoscopy was first introduced as a visualization tool. Gynecologists then began to employ minimally invasive surgery for adhesiolysis and obtaining biopsies but then expanded its use to include procedures such as tubal sterilization (Clyman (1963), L. E. Smale and M. L. Smale (1973), Thompson and Wheeless (1971), Peterson and Behrman (1971)). With advances in instrumentation, the first laparoscopic hysterectomy was successfully performed in 1989 by Reich et al. At the same time, minimally invasive surgery in gynecologic oncology was being developed alongside its benign counterpart. In the 1975s, Rosenoff et al. reported using peritoneoscopy for pretreatment evaluation in ovarian cancer, and Spinelli et al. reported on using laparoscopy for the staging of ovarian cancer. In 1993, Nichols used operative laparoscopy to perform pelvic lymphadenectomy in cervical cancer patients. The initial goals of minimally invasive surgery, not dissimilar to those of modern medicine, were to decrease the morbidity and mortality associated with surgery and therefore improve patient outcomes and patient satisfaction. This review will summarize the history and use of minimally invasive surgery in gynecologic oncology and also highlight new minimally invasive surgical approaches currently in development. PMID:23997959

  12. Perspectives on trans-Pacific biological invasions

    USGS Publications Warehouse

    Guo, Q.

    2002-01-01

    Trans-Pacific biological invasion is one of the most striking and influential biological phenomena occurring in modern times and the process is still accelerating, and the associated invasives form neo-disjuncts (cf. many well-known paleo-disjuncts) between eastern Asia and North America. To better understand this phenomenon and the related taxa, I address the following questions: 1) what types of species (e.g., life/growth form) have been, or are likely to be, associated with trans-Pacific (eastern Asia, North America) invasions; 2) what has happened or may happen to these species after their remote geographic separation, and 3) what aspects of these species and their native and non-native habitats should be better understood for improved control. To answer these questions, comparisons of the invasive species' characteristics in their native and invaded habitats need to be examined, including: l) genetics, 2) life history/morphology (e.g., plant size, seed size, etc.), 3) ecology (e.g., life/growth forms, pollinators, competitors), 4) distributions (e.g., range size, shape, latitude) in their native (source) and introduced (target) ranges or habitats, and 5) physical factors such as soil, water, and climate. The purpose of these studies is 1) to identify the limiting factors that restrict the distributions of exotic species in native ranges, 2) to understand why invasive species are successful in the introduced ranges, 3) to predict possible future invasions, and, ultimately, 4) to provide information for more efficient and effective management.

  13. Habitat cascades: the conceptual context and global relevance of facilitation cascades via habitat formation and modification.

    PubMed

    Thomsen, Mads S; Wernberg, Thomas; Altieri, Andrew; Tuya, Fernando; Gulbransen, Dana; McGlathery, Karen J; Holmer, Marianne; Silliman, Brian R

    2010-08-01

    The importance of positive interactions is increasingly acknowledged in contemporary ecology. Most research has focused on direct positive effects of one species on another. However, there is recent evidence that indirect positive effects in the form of facilitation cascades can also structure species abundances and biodiversity. Here we conceptualize a specific type of facilitation cascade-the habitat cascade. The habitat cascade is defined as indirect positive effects on focal organisms mediated by successive facilitation in the form of biogenic formation or modification of habitat. Based on a literature review, we demonstrate that habitat cascades are a general phenomenon that enhances species abundance and diversity in forests, salt marshes, seagrass meadows, and seaweed beds. Habitat cascades are characterized by a hierarchy of facilitative interactions in which a basal habitat former (typically a large primary producer, e.g., a tree) creates living space for an intermediate habitat former (e.g., an epiphyte) that in turn creates living space for the focal organisms (e.g., spiders, beetles, and mites). We then present new data on a habitat cascade common to soft-bottom estuaries in which a relatively small invertebrate provides basal habitat for larger intermediate seaweeds that, in turn, generate habitat for focal invertebrates and epiphytes. We propose that indirect positive effects on focal organisms will be strongest when the intermediate habitat former is larger and different in form and function from the basal habitat former. We also discuss how humans create, modify, and destroy habitat cascades via global habitat destruction, climatic change, over-harvesting, pollution, or transfer of invasive species. Finally, we outline future directions for research that will lead to a better understanding of habitat cascades. PMID:21558196

  14. Evolutionary increases in defense during a biological invasion.

    PubMed

    Liao, Zhi-Yong; Zheng, Yu-Long; Lei, Yan-Bao; Feng, Yu-Long

    2014-04-01

    Invasive plants generally escape from specialist herbivores of their native ranges but may experience serious damage from generalists. As a result, invasive plants may evolve increased resistance to generalists and tolerance to damage. To test these hypotheses, we carried out a common garden experiment comparing 15 invasive populations with 13 native populations of Chromolaena odorata, including putative source populations identified with molecular methods and binary choice feeding experiments using three generalist herbivores. Plants from invasive populations of C. odorata had both higher resistance to three generalists and higher tolerance to simulated herbivory (shoot removal) than plants from native populations. The higher resistance of plants from invasive populations was associated with higher leaf C content and densities of leaf trichomes and glandular scales, and lower leaf N and water contents. Growth costs were detected for tolerance but not for resistance, and plants from invasive populations of C. odorata showed lower growth costs of tolerance. Our results suggest that invasive plants may evolve to increase both resistance to generalists and tolerance to damage in introduced ranges, especially when the defense traits have low or no fitness costs. Greater defenses in invasive populations may facilitate invasion by C. odorata by reducing generalist impacts and increasing compensatory growth after damage has occurred.

  15. Invasion of novel habitats uncouples haplo-diplontic life cycles.

    PubMed

    Krueger-Hadfield, Stacy A; Kollars, Nicole M; Byers, James E; Greig, Thomas W; Hammann, Mareike; Murray, David C; Murren, Courtney J; Strand, Allan E; Terada, Ryuta; Weinberger, Florian; Sotka, Erik E

    2016-08-01

    Baker's Law predicts uniparental reproduction will facilitate colonization success in novel habitats. While evidence supports this prediction among colonizing plants and animals, few studies have investigated shifts in reproductive mode in haplo-diplontic species in which both prolonged haploid and diploid stages separate meiosis and fertilization in time and space. Due to this separation, asexual reproduction can yield the dominance of one of the ploidy stages in colonizing populations. We tested for shifts in ploidy and reproductive mode across native and introduced populations of the red seaweed Gracilaria vermiculophylla. Native populations in the northwest Pacific Ocean were nearly always attached by holdfasts to hard substrata and, as is characteristic of the genus, haploid-diploid ratios were slightly diploid-biased. In contrast, along North American and European coastlines, introduced populations nearly always floated atop soft-sediment mudflats and were overwhelmingly dominated by diploid thalli without holdfasts. Introduced populations exhibited population genetic signals consistent with extensive vegetative fragmentation, while native populations did not. Thus, the ecological shift from attached to unattached thalli, ostensibly necessitated by the invasion of soft-sediment habitats, correlated with shifts from sexual to asexual reproduction and slight to strong diploid bias. We extend Baker's Law by predicting other colonizing haplo-diplontic species will show similar increases in asexuality that correlate with the dominance of one ploidy stage. Labile mating systems likely facilitate colonization success and subsequent range expansion, but for haplo-diplontic species, the long-term eco-evolutionary impacts will depend on which ploidy stage is lost and the degree to which asexual reproduction is canalized. PMID:27286564

  16. Invasion of novel habitats uncouples haplo-diplontic life cycles.

    PubMed

    Krueger-Hadfield, Stacy A; Kollars, Nicole M; Byers, James E; Greig, Thomas W; Hammann, Mareike; Murray, David C; Murren, Courtney J; Strand, Allan E; Terada, Ryuta; Weinberger, Florian; Sotka, Erik E

    2016-08-01

    Baker's Law predicts uniparental reproduction will facilitate colonization success in novel habitats. While evidence supports this prediction among colonizing plants and animals, few studies have investigated shifts in reproductive mode in haplo-diplontic species in which both prolonged haploid and diploid stages separate meiosis and fertilization in time and space. Due to this separation, asexual reproduction can yield the dominance of one of the ploidy stages in colonizing populations. We tested for shifts in ploidy and reproductive mode across native and introduced populations of the red seaweed Gracilaria vermiculophylla. Native populations in the northwest Pacific Ocean were nearly always attached by holdfasts to hard substrata and, as is characteristic of the genus, haploid-diploid ratios were slightly diploid-biased. In contrast, along North American and European coastlines, introduced populations nearly always floated atop soft-sediment mudflats and were overwhelmingly dominated by diploid thalli without holdfasts. Introduced populations exhibited population genetic signals consistent with extensive vegetative fragmentation, while native populations did not. Thus, the ecological shift from attached to unattached thalli, ostensibly necessitated by the invasion of soft-sediment habitats, correlated with shifts from sexual to asexual reproduction and slight to strong diploid bias. We extend Baker's Law by predicting other colonizing haplo-diplontic species will show similar increases in asexuality that correlate with the dominance of one ploidy stage. Labile mating systems likely facilitate colonization success and subsequent range expansion, but for haplo-diplontic species, the long-term eco-evolutionary impacts will depend on which ploidy stage is lost and the degree to which asexual reproduction is canalized.

  17. Propagule Pressure, Habitat Conditions and Clonal Integration Influence the Establishment and Growth of an Invasive Clonal Plant, Alternanthera philoxeroides

    PubMed Central

    You, Wen-Hua; Han, Cui-Min; Fang, Long-Xiang; Du, Dao-Lin

    2016-01-01

    Many notorious invasive plants are clonal, spreading mainly by vegetative propagules. Propagule pressure (the number of propagules) may affect the establishment, growth, and thus invasion success of these clonal plants, and such effects may also depend on habitat conditions. To understand how propagule pressure, habitat conditions and clonal integration affect the establishment and growth of the invasive clonal plants, an 8-week greenhouse with an invasive clonal plant, Alternanthera philoxeroides was conducted. High (five fragments) or low (one fragment) propagule pressure was established either in bare soil (open habitat) or dense native vegetation of Jussiaea repens (vegetative habitat), with the stolon connections either severed from or connected to the relatively older ramets. High propagule pressure greatly increased the establishment and growth of A. philoxeroides, especially when it grew in vegetative habitats. Surprisingly, high propagule pressure significantly reduced the growth of individual plants of A. philoxeroides in open habitats, whereas it did not affect the individual growth in vegetative habitats. A shift in the intraspecific interaction on A. philoxeroides from competition in open habitats to facilitation in vegetative habitats may be the main reason. Moreover, clonal integration significantly improved the growth of A. philoxeroides only in open habitats, especially with low propagule pressure, whereas it had no effects on the growth and competitive ability of A. philoxeroides in vegetative habitats, suggesting that clonal integration may be of most important for A. philoxeroides to explore new open space and spread. These findings suggest that propagule pressure may be crucial for the invasion success of A. philoxeroides, and such an effect also depends on habitat conditions. PMID:27200041

  18. Propagule Pressure, Habitat Conditions and Clonal Integration Influence the Establishment and Growth of an Invasive Clonal Plant, Alternanthera philoxeroides.

    PubMed

    You, Wen-Hua; Han, Cui-Min; Fang, Long-Xiang; Du, Dao-Lin

    2016-01-01

    Many notorious invasive plants are clonal, spreading mainly by vegetative propagules. Propagule pressure (the number of propagules) may affect the establishment, growth, and thus invasion success of these clonal plants, and such effects may also depend on habitat conditions. To understand how propagule pressure, habitat conditions and clonal integration affect the establishment and growth of the invasive clonal plants, an 8-week greenhouse with an invasive clonal plant, Alternanthera philoxeroides was conducted. High (five fragments) or low (one fragment) propagule pressure was established either in bare soil (open habitat) or dense native vegetation of Jussiaea repens (vegetative habitat), with the stolon connections either severed from or connected to the relatively older ramets. High propagule pressure greatly increased the establishment and growth of A. philoxeroides, especially when it grew in vegetative habitats. Surprisingly, high propagule pressure significantly reduced the growth of individual plants of A. philoxeroides in open habitats, whereas it did not affect the individual growth in vegetative habitats. A shift in the intraspecific interaction on A. philoxeroides from competition in open habitats to facilitation in vegetative habitats may be the main reason. Moreover, clonal integration significantly improved the growth of A. philoxeroides only in open habitats, especially with low propagule pressure, whereas it had no effects on the growth and competitive ability of A. philoxeroides in vegetative habitats, suggesting that clonal integration may be of most important for A. philoxeroides to explore new open space and spread. These findings suggest that propagule pressure may be crucial for the invasion success of A. philoxeroides, and such an effect also depends on habitat conditions. PMID:27200041

  19. Indirect effects of habitat disturbance on invasion: nutritious litter from a grazing resistant plant favors alien over native Collembola.

    PubMed

    Leinaas, Hans Petter; Bengtsson, Jan; Janion-Scheepers, Charlene; Chown, Steven L

    2015-08-01

    Biological invasions are major threats to biodiversity, with impacts that may be compounded by other forms of environmental change. Observations of high density of the invasive springtail (Collembola), Hypogastrura manubrialis in heavily grazed renosterveld vegetation in the Western Cape, South Africa, raised the question of whether the invasion was favored by changes in plant litter quality associated with habitat disturbance in this vegetation type. To examine the likely mechanisms underlying the high abundance of H. manubrialis, cages with three types of naturally occurring litter with different nutrient content were placed out in the area and collected after different periods of time. Hypogastrura manubrialis was mainly found in the nutrient-rich litter of the yellowbush (Galenia africana), which responds positively to disturbance in the form of overgrazing. This suggests that invasion may have been facilitated by a positive interaction with this grazing resistant plant. By contrast, indigenous Collembola were least abundant in yellowbush litter. Negative correlations between high abundance of H. manubrialis and the abundance and diversity of other species suggest that competitive interactions might underlie low abundance of these other species at the patch level. Group behavior enables H. manubrialis to utilize efficiently this ephemeral, high quality resource, and might improve its competitive ability. The results suggest that interactions among environmental change drivers may lead to unforeseen invasion effects. H. manubrialis is not likely to be very successful in un-grazed renosterveld, but in combination with grazing, favoring the nutrient-rich yellowbush, it may become highly invasive. Field manipulations are required to fully verify these conclusions. PMID:26380678

  20. Indirect effects of habitat disturbance on invasion: nutritious litter from a grazing resistant plant favors alien over native Collembola

    PubMed Central

    Leinaas, Hans Petter; Bengtsson, Jan; Janion-Scheepers, Charlene; Chown, Steven L

    2015-01-01

    Biological invasions are major threats to biodiversity, with impacts that may be compounded by other forms of environmental change. Observations of high density of the invasive springtail (Collembola), Hypogastrura manubrialis in heavily grazed renosterveld vegetation in the Western Cape, South Africa, raised the question of whether the invasion was favored by changes in plant litter quality associated with habitat disturbance in this vegetation type. To examine the likely mechanisms underlying the high abundance of H. manubrialis, cages with three types of naturally occurring litter with different nutrient content were placed out in the area and collected after different periods of time. Hypogastrura manubrialis was mainly found in the nutrient-rich litter of the yellowbush (Galenia africana), which responds positively to disturbance in the form of overgrazing. This suggests that invasion may have been facilitated by a positive interaction with this grazing resistant plant. By contrast, indigenous Collembola were least abundant in yellowbush litter. Negative correlations between high abundance of H. manubrialis and the abundance and diversity of other species suggest that competitive interactions might underlie low abundance of these other species at the patch level. Group behavior enables H. manubrialis to utilize efficiently this ephemeral, high quality resource, and might improve its competitive ability. The results suggest that interactions among environmental change drivers may lead to unforeseen invasion effects. H. manubrialis is not likely to be very successful in un-grazed renosterveld, but in combination with grazing, favoring the nutrient-rich yellowbush, it may become highly invasive. Field manipulations are required to fully verify these conclusions. PMID:26380678

  1. Biogeographical plant-soil relations of invasive medusahead (Elymus caput-medusae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Understanding the mechanisms that underlie the success of invasive plant species is integral to predicting and ameliorating their negative impacts. Many hypotheses have consequently been proposed to explain invasive behavior. This lack of consensus within invasion ecology can partially be attributed...

  2. Germination and seedling frost tolerance differ between the native and invasive range in common ragweed.

    PubMed

    Leiblein-Wild, Marion Carmen; Kaviani, Rana; Tackenberg, Oliver

    2014-03-01

    Germination characteristics and frost tolerance of seedlings are crucial parameters for establishment and invasion success of plants. The characterization of differences between populations in native and invasive ranges may improve our understanding of range expansion and adaptation. Here, we investigated germination characteristics of Ambrosia artemisiifolia L., a successful invader in Europe, under a temperature gradient between 5 and 25 °C. Besides rate and speed of germination we determined optimal, minimal and maximal temperature for germination of ten North American and 17 European populations that were sampled along major latitudinal and longitudinal gradients. We furthermore investigated the frost tolerance of seedlings. Germination rate was highest at 15 °C and germination speed was highest at 25 °C. Germination rate, germination speed, frost tolerance of seedlings, and the temperature niche width for germination were significantly higher and broader, respectively, for European populations. This was partly due to a higher seed mass of these populations. Germination traits lacked evidence for adaptation to climatic variables at the point of origin for both provenances. Instead, in the native range, seedling frost tolerance was positively correlated with the risk of frosts which supports the assumption of local adaptation. The increased frost tolerance of European populations may allow germination earlier in the year which may subsequently lead to higher biomass allocation--due to a longer growing period--and result in higher pollen and seed production. The increase in germination rates, germination speed and seedling frost tolerance might result in a higher fitness of the European populations which may facilitate further successful invasion and enhance the existing public health problems associated with this species.

  3. Minimally Invasive Valve Surgery

    PubMed Central

    Pope, Nicolas H.; Ailawadi, Gorav

    2014-01-01

    Cardiac valve surgery is life saving for many patients. The advent of minimally invasive surgical techniques has historically allowed for improvement in both post-operative convalescence and important clinical outcomes. The development of minimally invasive cardiac valve repair and replacement surgery over the past decade is poised to revolutionize the care of cardiac valve patients. Here, we present a review of the history and current trends in minimally invasive aortic and mitral valve repair and replacement, including the development of sutureless bioprosthetic valves. PMID:24797148

  4. Successful Treatment of Invasive Pulmonary Mucormycosis in an Immunocompromised Patient.

    PubMed

    Afolayan, Oluwatobi; Copeland, Hannah; Hargrove, Rachel; Zaheer, Salman; Wallen, Jason M

    2016-04-01

    A 59-year-old man undergoing chemotherapy for acute myelogenous leukemia had a bilateral pneumonic process. The right lung subsequently developed several small cavitary lesions extending from the central hilum to the chest wall. Despite medical therapy, repeat imaging demonstrated coalescence into a single, large, central cavitary lesion. Thoracic surgery was consulted because of the central hilar involvement of all three lobes; a pneumonectomy would have been required to resect the lesion. However, he was not a candidate for pneumonectomy because of a low predicted postoperative forced expiratory volume in 1 second. We performed a rib resection, debridement, and marsupialization, in which the skin was sewn circumferentially to the parietal pleura. His wound was managed with wet-to-dry dressings. Postoperatively, he recovered well, with resolution of his cough. Three weeks after surgery, he was discharged from the hospital, and the cavity completely closed at 4 months. PMID:27000614

  5. Invasive Prenatal Testing

    PubMed Central

    Hunter, A.

    1988-01-01

    Invasive prenatal diagnosis is a major diagnostic tool which is used in modern obstetrical care. A synopsis of these techniques is provided to assist the family practitioner in providing this information to his patients. PMID:21253097

  6. 76 FR 18575 - Nominations of New Members to the Invasive Species Advisory Committee (ISAC)

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-04

    ... international cooperation in addressing invasive species; facilitates the development of a coordinated network... issues. ISAC provides advice in cooperation with stakeholders and existing organizations addressing...; coordinating diverse groups of stakeholders to resolve complex environmental issues and conflicts;...

  7. From molecules to management: adopting DNA-based methods for monitoring biological invasions in aquatic environments

    EPA Science Inventory

    Recent technological advances have driven rapid development of DNA-based methods designed to facilitate detection and monitoring of invasive species in aquatic environments. These tools promise to significantly alleviate difficulties associated with traditional monitoring approac...

  8. Mechatronic Feasibility of Minimally Invasive, Atraumatic Cochleostomy

    PubMed Central

    Caversaccio, Marco; Proops, David; Brett, Peter

    2014-01-01

    Robotic assistance in the context of lateral skull base surgery, particularly during cochlear implantation procedures, has been the subject of considerable research over the last decade. The use of robotics during these procedures has the potential to provide significant benefits to the patient by reducing invasiveness when gaining access to the cochlea, as well as reducing intracochlear trauma when performing a cochleostomy. Presented herein is preliminary work on the combination of two robotic systems for reducing invasiveness and trauma in cochlear implantation procedures. A robotic system for minimally invasive inner ear access was combined with a smart drilling tool for robust and safe cochleostomy; evaluation was completed on a single human cadaver specimen. Access to the middle ear was successfully achieved through the facial recess without damage to surrounding anatomical structures; cochleostomy was completed at the planned position with the endosteum remaining intact after drilling as confirmed by microscope evaluation. PMID:25110661

  9. Non-Invasive Prenatal Diagnosis of Lethal Skeletal Dysplasia by Targeted Capture Sequencing of Maternal Plasma

    PubMed Central

    Wang, Yaoshen; Chen, Chao; Gao, Changxin; Yu, Song; Liu, Yan; Song, Wei; Asan; Zhu, Hongmei; Yang, Ling; Deng, Hongmei; Su, Yue; Yi, Xin

    2016-01-01

    Background Since the discovery of cell-free foetal DNA in the plasma of pregnant women, many non-invasive prenatal testing assays have been developed. In the area of skeletal dysplasia diagnosis, some PCR-based non-invasive prenatal testing assays have been developed to facilitate the ultrasound diagnosis of skeletal dysplasias that are caused by de novo mutations. However, skeletal dysplasias are a group of heterogeneous genetic diseases, the PCR-based method is hard to detect multiple gene or loci simultaneously, and the diagnosis rate is highly dependent on the accuracy of the ultrasound diagnosis. In this study, we investigated the feasibility of using targeted capture sequencing to detect foetal de novo pathogenic mutations responsible for skeletal dysplasia. Methodology/Principal Findings Three families whose foetuses were affected by skeletal dysplasia and two control families whose foetuses were affected by other single gene diseases were included in this study. Sixteen genes related to some common lethal skeletal dysplasias were selected for analysis, and probes were designed to capture the coding regions of these genes. Targeted capture sequencing was performed on the maternal plasma DNA, the maternal genomic DNA, and the paternal genomic DNA. The de novo pathogenic variants in the plasma DNA data were identified using a bioinformatical process developed for low frequency mutation detection and a strict variant interpretation strategy. The causal variants could be specifically identified in the plasma, and the results were identical to those obtained by sequencing amniotic fluid samples. Furthermore, a mean of 97% foetal specific alleles, which are alleles that are not shared by maternal genomic DNA and amniotic fluid DNA, were identified successfully in plasma samples. Conclusions/Significance Our study shows that capture sequencing of maternal plasma DNA can be used to non-invasive detection of de novo pathogenic variants. This method has the potential

  10. The Essential Elements of Facilitation.

    ERIC Educational Resources Information Center

    Priest, Simon; Gass, Michael; Gillis, Lee

    Most organizations find it difficult to implement change, and only about 10 percent of learning from training and development experiences is actually applied in the workplace. This book advocates facilitation as a means of enhancing change and increasing productivity. Facilitation engages employees by enhancing the processes associated with their…

  11. Facilitating Dialogues about Racial Realities

    ERIC Educational Resources Information Center

    Quaye, Stephen John

    2014-01-01

    Background/Context: Facilitating dialogues about racial issues in higher education classroom settings continues to be a vexing problem facing postsecondary educators. In order for students to discuss race with their peers, they need skilled facilitators who are knowledgeable about racial issues and able to support students in these difficult…

  12. Landscape corridors can increase invasion by an exotic species and reduce diversity of native species

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Although corridors have become commonplace in conservation to mitigate negative effects of habitat fragmentation, concerns persist that they may facilitate spread of invasive species. In a large-scale experiment, we measured effects of corridors on invasive fire ants, Solenopsis invicta, and on comm...

  13. The diagnosis and management of pre-invasive breast disease: Promise of new technologies in understanding pre-invasive breast lesions

    PubMed Central

    Jeffrey, Stefanie S; Pollack, Jonathan R

    2003-01-01

    Array-based comparative genomic hybridization, RNA expression profiling, and proteomic analyses are new molecular technologies used to study breast cancer. Invasive breast cancers were originally evaluated because they provided ample quantities of DNA, RNA, and protein. The application of these technologies to pre-invasive breast lesions is discussed, including methods that facilitate their implementation. Data indicate that atypical ductal hyperplasia and ductal carcinoma in situ are precursor lesions molecularly similar to adjacent invasive breast cancer. It is expected that molecular technologies will identify breast tissue at risk for the development of unfavorable subtypes of invasive breast cancer and reveal strategies for targeted chemoprevention or eradication. PMID:14580250

  14. Integrin β4 regulates SPARC protein to promote invasion.

    PubMed

    Gerson, Kristin D; Shearstone, Jeffrey R; Maddula, V S R Krishna; Seligmann, Bruce E; Mercurio, Arthur M

    2012-03-23

    The α6β4 integrin (referred to as "β4" integrin) is a receptor for laminins that promotes carcinoma invasion through its ability to regulate key signaling pathways and cytoskeletal dynamics. An analysis of published Affymetrix GeneChip data to detect downstream effectors involved in β4-mediated invasion of breast carcinoma cells identified SPARC, or secreted protein acidic and rich in cysteine. This glycoprotein has been shown to play an important role in matrix remodeling and invasion. Our analysis revealed that manipulation of β4 integrin expression and signaling impacted SPARC expression and that SPARC facilitates β4-mediated invasion. Expression of β4 in β4-deficient cells reduced the expression of a specific microRNA (miR-29a) that targets SPARC and impedes invasion. In cells that express endogenous β4, miR-29a expression is low and β4 ligation facilitates the translation of SPARC through a TOR-dependent mechanism. The results obtained in this study demonstrate that β4 can regulate SPARC expression and that SPARC is an effector of β4-mediated invasion. They also highlight a potential role for specific miRNAs in executing the functions of integrins.

  15. Multi level ecological fitting: indirect life cycles are not a barrier to host switching and invasion.

    PubMed

    Malcicka, Miriama; Agosta, Salvatore J; Harvey, Jeffrey A

    2015-09-01

    Many invasive species are able to escape from coevolved enemies and thus enjoy a competitive advantage over native species. However, during the invasion phase, non-native species must overcome many ecological and/or physiological hurdles before they become established and spread in their new habitats. This may explain why most introduced species either fail to establish or remain as rare interstitials in their new ranges. Studies focusing on invasive species have been based on plants or animals where establishment requires the possession of preadapted traits from their native ranges that enables them to establish and spread in their new habitats. The possession of preadapted traits that facilitate the exploitation of novel resources or to colonize novel habitats is known as 'ecological fitting'. Some species have evolved traits and life histories that reflect highly intimate associations with very specific types of habitats or niches. For these species, their phenological windows are narrow, and thus the ability to colonize non-native habitats requires that a number of conditions need to be met in accordance with their more specialized life histories. Some of the strongest examples of more complex ecological fitting involve invasive parasites that require different animal hosts to complete their life cycles. For instance, the giant liver fluke, Fascioloides magna, is a major parasite of several species of ungulates in North America. The species exhibits a life cycle whereby newly hatched larvae must find suitable intermediate hosts (freshwater snails) and mature larvae, definitive hosts (ungulates). Intermediate and definitive host ranges of F. magna in its native range are low in number, yet this parasite has been successfully introduced into Europe where it has become a parasite of native European snails and deer. We discuss how the ability of these parasites to overcome multiple ecophysiological barriers represents an excellent example of 'multiple

  16. Successful Predictions

    NASA Astrophysics Data System (ADS)

    Pierrehumbert, R.

    2012-12-01

    In an observational science, it is not possible to test hypotheses through controlled laboratory experiments. One can test parts of the system in the lab (as is done routinely with infrared spectroscopy of greenhouse gases), but the collective behavior cannot be tested experimentally because a star or planet cannot be brought into the lab; it must, instead, itself be the lab. In the case of anthropogenic global warming, this is all too literally true, and the experiment would be quite exciting if it weren't for the unsettling fact that we and all our descendents for the forseeable future will have to continue making our home in the lab. There are nonetheless many routes though which the validity of a theory of the collective behavior can be determined. A convincing explanation must not be a"just-so" story, but must make additional predictions that can be verified against observations that were not originally used in formulating the theory. The field of Earth and planetary climate has racked up an impressive number of such predictions. I will also admit as "predictions" statements about things that happened in the past, provided that observations or proxies pinning down the past climate state were not available at the time the prediction was made. The basic prediction that burning of fossil fuels would lead to an increase of atmospheric CO2, and that this would in turn alter the Earth's energy balance so as to cause tropospheric warming, is one of the great successes of climate science. It began in the lineage of Fourier, Tyndall and Arrhenius, and was largely complete with the the radiative-convective modeling work of Manabe in the 1960's -- all well before the expected warming had progressed far enough to be observable. Similarly, long before the increase in atmospheric CO2 could be detected, Bolin formulated a carbon cycle model and used it to predict atmospheric CO2 out to the year 2000; the actual values come in at the high end of his predicted range, for

  17. Minimally invasive procedures

    PubMed Central

    Baltayiannis, Nikolaos; Michail, Chandrinos; Lazaridis, George; Anagnostopoulos, Dimitrios; Baka, Sofia; Mpoukovinas, Ioannis; Karavasilis, Vasilis; Lampaki, Sofia; Papaiwannou, Antonis; Karavergou, Anastasia; Kioumis, Ioannis; Pitsiou, Georgia; Katsikogiannis, Nikolaos; Tsakiridis, Kosmas; Rapti, Aggeliki; Trakada, Georgia; Zissimopoulos, Athanasios; Zarogoulidis, Konstantinos

    2015-01-01

    Minimally invasive procedures, which include laparoscopic surgery, use state-of-the-art technology to reduce the damage to human tissue when performing surgery. Minimally invasive procedures require small “ports” from which the surgeon inserts thin tubes called trocars. Carbon dioxide gas may be used to inflate the area, creating a space between the internal organs and the skin. Then a miniature camera (usually a laparoscope or endoscope) is placed through one of the trocars so the surgical team can view the procedure as a magnified image on video monitors in the operating room. Specialized equipment is inserted through the trocars based on the type of surgery. There are some advanced minimally invasive surgical procedures that can be performed almost exclusively through a single point of entry—meaning only one small incision, like the “uniport” video-assisted thoracoscopic surgery (VATS). Not only do these procedures usually provide equivalent outcomes to traditional “open” surgery (which sometimes require a large incision), but minimally invasive procedures (using small incisions) may offer significant benefits as well: (I) faster recovery; (II) the patient remains for less days hospitalized; (III) less scarring and (IV) less pain. In our current mini review we will present the minimally invasive procedures for thoracic surgery. PMID:25861610

  18. Alien invasive birds.

    PubMed

    Brochier, B; Vangeluwe, D; van den Berg, T

    2010-08-01

    A bird species is regarded as alien invasive if it has been introduced, intentionally or accidentally, to a location where it did not previously occur naturally, becomes capable of establishing a breeding population without further intervention by humans, spreads and becomes a pest affecting the environment, the local biodiversity, the economy and/or society, including human health. European Starling (Sturnus vulgaris), Common Myna (Acridotheres tristis) and Red-vented Bulbul (Pycnonotus cafer) have been included on the list of '100 of the World's Worst Invasive Alien Species', a subset of the Global Invasive Species Database. The 'Delivering Alien Invasive Species Inventories for Europe' project has selected Canada Goose (Branta canadensis), Ruddy Duck (Oxyura jamaicensis), Rose-ringed Parakeet (Psittacula krameri) and Sacred Ibis (Threskiornis aethiopicus) as among 100 of the worst invasive species in Europe. For each of these alien bird species, the geographic range (native and introduced range), the introduction pathway, the general impacts and the management methods are presented. PMID:20919578

  19. Resource competition in plant invasions: emerging patterns and research needs.

    PubMed

    Gioria, Margherita; Osborne, Bruce A

    2014-01-01

    Invasions by alien plants provide a unique opportunity to examine competitive interactions among plants. While resource competition has long been regarded as a major mechanism responsible for successful invasions, given a well-known capacity for many invaders to become dominant and reduce plant diversity in the invaded communities, few studies have measured resource competition directly or have assessed its importance relative to that of other mechanisms, at different stages of an invasion process. Here, we review evidence comparing the competitive ability of invasive species vs. that of co-occurring native plants, along a range of environmental gradients, showing that many invasive species have a superior competitive ability over native species, although invasive congeners are not necessarily competitively superior over native congeners, nor are alien dominants are better competitors than native dominants. We discuss how the outcomes of competition depend on a number of factors, such as the heterogeneous distribution of resources, the stage of the invasion process, as well as phenotypic plasticity and evolutionary adaptation, which may result in increased or decreased competitive ability in both invasive and native species. Competitive advantages of invasive species over natives are often transient and only important at the early stages of an invasion process. It remains unclear how important resource competition is relative to other mechanisms (competition avoidance via phenological differences, niche differentiation in space associated with phylogenetic distance, recruitment and dispersal limitation, indirect competition, and allelopathy). Finally, we identify the conceptual and methodological issues characterizing competition studies in plant invasions, and we discuss future research needs, including examination of resource competition dynamics and the impact of global environmental change on competitive interactions between invasive and native species.

  20. Resource competition in plant invasions: emerging patterns and research needs

    PubMed Central

    Gioria, Margherita; Osborne, Bruce A.

    2014-01-01

    Invasions by alien plants provide a unique opportunity to examine competitive interactions among plants. While resource competition has long been regarded as a major mechanism responsible for successful invasions, given a well-known capacity for many invaders to become dominant and reduce plant diversity in the invaded communities, few studies have measured resource competition directly or have assessed its importance relative to that of other mechanisms, at different stages of an invasion process. Here, we review evidence comparing the competitive ability of invasive species vs. that of co-occurring native plants, along a range of environmental gradients, showing that many invasive species have a superior competitive ability over native species, although invasive congeners are not necessarily competitively superior over native congeners, nor are alien dominants are better competitors than native dominants. We discuss how the outcomes of competition depend on a number of factors, such as the heterogeneous distribution of resources, the stage of the invasion process, as well as phenotypic plasticity and evolutionary adaptation, which may result in increased or decreased competitive ability in both invasive and native species. Competitive advantages of invasive species over natives are often transient and only important at the early stages of an invasion process. It remains unclear how important resource competition is relative to other mechanisms (competition avoidance via phenological differences, niche differentiation in space associated with phylogenetic distance, recruitment and dispersal limitation, indirect competition, and allelopathy). Finally, we identify the conceptual and methodological issues characterizing competition studies in plant invasions, and we discuss future research needs, including examination of resource competition dynamics and the impact of global environmental change on competitive interactions between invasive and native species. PMID

  1. Intrapartum ST segment analyses (STAN) using simultaneous invasive and non-invasive fetal electrocardiography: a report of 6 cases.

    PubMed

    Reinhard, J; Hayes-Gill, B; Yuan, J; Schiermeier, S; Louwen, F

    2014-06-01

    The objective of this study was to analyze ST segment analyses (STAN) using simultaneous traditional - gold standard invasive (fetal scalp electrode) and newly available non-invasive abdominal fetal electrocardiography (fECG) during delivery.This was a prospective observational study of non-invasive fetal ECG using 5 abdominally sited electrodes (Monica AN24) against the traditional fetal scalp electrodes (STAN S31) on 6 patients. Data were analyzed when the STAN S31 found the baseline and when there was a baseline rise.Successful fECG signal acquisition was achieved in 6/6 (100%) patients. Using the non-invasive fECG, P and QRS waves were seen in all cases, and T waves in 3/6 (50%). ST segment analysis analysis was possible in 6/6 (100%) and 3/6 (50%) using invasive and non-invasive fECG, respectively.This study demonstrates that ST segment analysis is feasible using invasive and non-invasive fECG. Further studies are warranted to confirm the preliminary results and improve ECG morphology of non-invasive fECG.

  2. A Modified In vitro Invasion Assay to Determine the Potential Role of Hormones, Cytokines and/or Growth Factors in Mediating Cancer Cell Invasion.

    PubMed

    Bagati, Archis; Koch, Zethan; Bofinger, Diane; Goli, Haneesha; Weiss, Laura S; Dau, Rosie; Thomas, Megha; Zucker, Shoshanna N

    2015-04-24

    Blood serum serves as a chemoattractant towards which cancer cells migrate and invade, facilitating their intravasation into microvessels. However, the actual molecules towards which the cells migrate remain elusive. This modified invasion assay has been developed to identify targets which drive cell migration and invasion. This technique compares the invasion index under three conditions to determine whether a specific hormone, growth factor, or cytokine plays a role in mediating the invasive potential of a cancer cell. These conditions include i) normal fetal bovine serum (FBS), ii) charcoal-stripped FBS (CS-FBS), which removes hormones, growth factors, and cytokines and iii) CS-FBS + molecule (denoted "X"). A significant change in cell invasion with CS-FBS as compared to FBS, indicates the involvement of hormones, cytokines or growth factors in mediating the change. Individual molecules can then be added back to CS-FBS to assay their ability to reverse or rescue the invasion phenotype. Furthermore, two or more factors can be combined to evaluate the additive or synergistic effects of multiple molecules in driving or inhibiting invasion. Overall, this method enables the investigator to determine whether hormones, cytokines, and/or growth factors play a role in cell invasion by serving as chemoattractants or inhibitors of invasion for a particular type of cancer cell or a specific mutant. By identifying specific chemoattractants and inhibitors, this modified invasion assay may help to elucidate signaling pathways that direct cancer cell invasion.

  3. Linkages of plant–soil feedbacks and underlying invasion mechanisms

    PubMed Central

    Inderjit; Cahill, James F.

    2015-01-01

    Soil microbial communities and processes have repeatedly been shown to impact plant community assembly and population growth. Soil-driven effects may be particularly pronounced with the introduction of plants to non-native ranges, as introduced plants are not typically accompanied by transference of local soil communities. Here we describe how the mechanisms by which soil community processes influence plant growth overlap with several known and well-described mechanisms of plant invasion. Critically, a given soil community process may either facilitate or limit invasion, depending upon local conditions and the specific mechanisms of soil processes involved. Additionally, as soil communities typically consist of species with short generation times, the net consequences of plant–soil feedbacks for invasion trajectories are likely to change over time, as ecological and evolutionary adjustments occur. Here we provide an overview of the ecological linkages of plant–soil feedbacks and underlying mechanisms of invasion. PMID:25784668

  4. Drought and ice plant invasion in Bodega Bay, California

    NASA Astrophysics Data System (ADS)

    Weill, A.

    2014-12-01

    Ice plant (Carpobrotus edulis) is a succulent native to South Africa that is widespread in coastal California. Ice plant invasion is facilitated by the plant's ability to compete for water. More frequent drought due to climate change could enhance the invasive potential of ice plant due to its succulent properties and potential to access and compete for water under drought conditions. However, ice plant spread may be slowed due to water stress under drought despite a potential competitive advantage. We test the alternative hypotheses that invasive potential increases or decreases during times of drought by analyzing ice plant spread during past droughts at Bodega Bay, California using analysis of aerial photographs taken over the last two decades. The results of this analysis may reveal how ice plant may behave in future drought years and provide useful information for invasive species management.

  5. Invasive Plant Management in the United States National Wildlife Refuge

    USGS Publications Warehouse

    Lusk, Michael; Ericson, Jenny

    2011-01-01

    Invasive species pose a significant challenge to the National Wildlife Refuge System and have been identified as the single most important threat to habitat management on refuges. At present, it is estimated that over 2 million acres of refuge lands are invaded by invasive plants. The current and potential costs of controlling invasive plants, as well as monitoring and restoring refuge lands, are significant both financially and ecologically. Budgetary expenditures for invasive species projects in FY 2009 totaled $18.4 million. A number of strategies are used to confront this threat and have resulted in success on a variety of levels. The Refuge System utilizes key partnerships, invasive species strike teams, and a dedicated cadre of volunteers to implement projects that incorporate mechanical, chemical and biological control methods.

  6. The role of environmental gradients in non-native plant invasion into burnt areas of Yosemite National Park, California

    USGS Publications Warehouse

    Klinger, R.; Underwood, E.C.; Moore, P.E.

    2006-01-01

    Fire is known to facilitate the invasion of many non-native plant species, but how invasion into burnt areas varies along environmental gradients is not well-understood. We used two pre-existing data sets to analyse patterns of invasion by non-native plant species into burnt areas along gradients of topography, soil and vegetation structure in Yosemite National Park, California, USA. A total of 46 non-native species (all herbaceous) were recorded in the two data sets. They occurred in all seven of the major plant formations in the park, but were least common in subalpine and upper montane conifer forests. There was no significant difference in species richness or cover of non-natives between burnt and unburnt areas for either data set, and environmental gradients had a stronger effect on patterns of non-native species distribution, abundance and species composition than burning. Cover and species richness of non-natives had significant positive correlations with slope (steepness) and herbaceous cover, while species richness had significant negative correlations with elevation, the number of years post-burn, and cover of woody vegetation. Non-native species comprised a relatively minor component of the vegetation in both burnt and unburnt areas in Yosemite (percentage species Combining double low line 4%, mean cover < 6.0%), and those species that did occur in burnt areas tended not to persist over time. The results indicate that in many western montane ecosystems, fire alone will not necessarily result in increased rates of invasion into burnt areas. However, it would be premature to conclude that non-native species could not affect post-fire succession patterns in these systems. Short fire-return intervals and high fire severity coupled with increased propagule pressure from areas used heavily by humans could still lead to high rates of invasion, establishment and spread even in highly protected areas such as Yosemite. ?? 2006 Blackwell Publishing Ltd.

  7. The effects of local spatial structure on epidemiological invasions.

    PubMed Central

    Keeling, M J

    1999-01-01

    Predicting the likely success of invasions is vitally important in ecology and especially epidemiology. Whether an organism can successfully invade and persist in the short-term is highly dependent on the spatial correlations that develop in the early stages of invasion. By modelling the correlations between individuals, we are able to understand the role of spatial heterogeneity in invasion dynamics without the need for large-scale computer simulations. Here, a natural methodology is developed for modelling the behaviour of individuals in a fixed network. This formulation is applied to the spread of a disease through a structured network to determine invasion thresholds and some statistical properties of a single epidemic. PMID:10343409

  8. Integrating biological invasions, climate change and phenotypic plasticity.

    PubMed

    Engel, Katharina; Tollrian, Ralph; Jeschke, Jonathan M

    2011-05-01

    Invasive species frequently change the ecosystems where they are introduced, e.g., by affecting species interactions and population densities of native species. We outline the connectedness of biological invasions, climate change and the phenomenon of phenotypic plasticity. Integrating these hot topics is important for understanding the biology of many species, their information transfer and general interactions with other organisms. One example where this is particularly true is the zooplankton species Daphnia lumholtzi, which has successfully invaded North America. The combination of a high thermal tolerance and a phenotypically plastic defense in D. lumholtzi might be responsible for its invasion success. Its morphological defense consists of rigid spines and is formed after sensory detecting the presence of native fish predators. The integration of biological invasions, climate change and phenotypic plasticity is an important goal for integrative biology.

  9. Integrating biological invasions, climate change and phenotypic plasticity

    PubMed Central

    Tollrian, Ralph; Jeschke, Jonathan M

    2011-01-01

    Invasive species frequently change the ecosystems where they are introduced, e.g., by affecting species interactions and population densities of native species. We outline the connectedness of biological invasions, climate change and the phenomenon of phenotypic plasticity. Integrating these hot topics is important for understanding the biology of many species, their information transfer and general interactions with other organisms. One example where this is particularly true is the zooplankton species Daphnia lumholtzi, which has successfully invaded North America. The combination of a high thermal tolerance and a phenotypically plastic defense in D. lumholtzi might be responsible for its invasion success. Its morphological defense consists of rigid spines and is formed after sensory detecting the presence of native fish predators. The integration of biological invasions, climate change and phenotypic plasticity is an important goal for integrative biology. PMID:21980551

  10. Invasion of dentinal tubules by oral bacteria.

    PubMed

    Love, R M; Jenkinson, H F

    2002-01-01

    Bacterial invasion of dentinal tubules commonly occurs when dentin is exposed following a breach in the integrity of the overlying enamel or cementum. Bacterial products diffuse through the dentinal tubule toward the pulp and evoke inflammatory changes in the pulpo-dentin complex. These may eliminate the bacterial insult and block the route of infection. Unchecked, invasion results in pulpitis and pulp necrosis, infection of the root canal system, and periapical disease. While several hundred bacterial species are known to inhabit the oral cavity, a relatively small and select group of bacteria is involved in the invasion of dentinal tubules and subsequent infection of the root canal space. Gram-positive organisms dominate the tubule microflora in both carious and non-carious dentin. The relatively high numbers of obligate anaerobes present-such as Eubacterium spp., Propionibacterium spp., Bifidobacterium spp., Peptostreptococcus micros, and Veillonella spp.-suggest that the environment favors growth of these bacteria. Gram-negative obligate anaerobic rods, e.g., Porphyromonas spp., are less frequently recovered. Streptococci are among the most commonly identified bacteria that invade dentin. Recent evidence suggests that streptococci may recognize components present within dentinal tubules, such as collagen type I, which stimulate bacterial adhesion and intra-tubular growth. Specific interactions of other oral bacteria with invading streptococci may then facilitate the invasion of dentin by select bacterial groupings. An understanding the mechanisms involved in dentinal tubule invasion by bacteria should allow for the development of new control strategies, such as inhibitory compounds incorporated into oral health care products or dental materials, which would assist in the practice of endodontics. PMID:12097359

  11. Does Mutualism Drive the Invasion of Two Alien Species? The Case of Solenopsis invicta and Phenacoccus solenopsis

    PubMed Central

    Zhou, Aiming; Lu, Yongyue; Zeng, Ling; Xu, Yijuan; Liang, Guangwen

    2012-01-01

    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 success of both

  12. Early Primary Invasion Scientists

    ERIC Educational Resources Information Center

    Spellman, Katie V.; Villano, Christine P.

    2011-01-01

    "We really need to get the government involved," said one student, holding his graph up to USDA scientist Steve Seefeldt. Dr. Steve studies methods to control "invasive" plants, plants that have been introduced to an area by humans and have potential to spread rapidly and negatively affect ecosystems. The first grader and his classmates had become…

  13. Aquatic invasive species

    USGS Publications Warehouse

    Thorsteinson, Lyman

    2005-01-01

    Invasive species are plants or animals that are present in an ecosystem beyond their native range. They may have few natural controls in their new environment and proliferate. They can threaten native species and interfere with human activities. The Western Fisheries Research Center (WFRC) has been conducting research to understand how non-native species invade and affect ecosystems, thus aiding management efforts.

  14. Stochastic dynamics of the prisoner's dilemma with cooperation facilitators.

    PubMed

    Mobilia, Mauro

    2012-07-01

    In the framework of the paradigmatic prisoner's dilemma game, we investigate the evolutionary dynamics of social dilemmas in the presence of "cooperation facilitators." In our model, cooperators and defectors interact as in the classical prisoner's dilemma, where selection favors defection. However, here the presence of a small number of cooperation facilitators enhances the fitness (reproductive potential) of cooperators, while it does not alter that of defectors. In a finite population of size N, the dynamics of the prisoner's dilemma with facilitators is characterized by the probability that cooperation takes over (fixation probability) by the mean times to reach the absorbing states. These quantities are computed exactly using Fokker-Planck equations. Our findings, corroborated by stochastic simulations, demonstrate that the influence of facilitators crucially depends on the difference between their density z and the game's cost-to-benefit ratio r. When z > r, the fixation of cooperators is likely in a large population and, under weak selection pressure, invasion and replacement of defection by cooperation is favored by selection if b(z - r)(1 - z) > N(-1), where 0facilitators but defection is the dominating strategy.

  15. Invasive and Non-Invasive Congeners Show Similar Trait Shifts between Their Same Native and Non-Native Ranges

    PubMed Central

    García, Yedra; Callaway, Ragan M.; Diaconu, Alecu; Montesinos, Daniel

    2013-01-01

    Differences in morphological or ecological traits expressed by exotic species between their native and non-native ranges are often interpreted as evidence for adaptation to new conditions in the non-native ranges. In turn this adaptation is often hypothesized to contribute to the successful invasion of these species. There is good evidence for rapid evolution by many exotic invasives, but the extent to which these evolutionary changes actually drive invasiveness is unclear. One approach to resolving the relationship between adaptive responses and successful invasion is to compare traits between populations from the native and non-native ranges for both exotic invaders and congeners that are exotic but not invasive. We compared a suite of morphological traits that are commonly tested in the literature in the context of invasion for three very closely related species of Centaurea, all of which are sympatric in the same native and non-native ranges in Europe and North America. Of these, C. solstitialis is highly invasive whereas C. calcitrapa and C. sulphurea are not. For all three species, plants from non-native populations showed similar shifts in key traits that have been identified in other studies as important putative adaptive responses to post-introduction invasion. For example, for all three species plants from populations in non-native ranges were (i) larger and (ii) produced seeds that germinated at higher rates. In fact, the non-invasive C. calcitrapa showed the strongest trait shift between ranges. Centaurea solstitialis was the only species for which plants from the non-native range increased allocation to defensive spines, and allocated proportionally less resources to reproduction, patterns contrary to what would be predicted by theory and other empirical studies to enhance invasion. Our results suggest caution when interpreting the commonly observed increase in size and reproductive capacity as factors that cause exotics to become invaders. PMID

  16. Invasive and non-invasive congeners show similar trait shifts between their same native and non-native ranges.

    PubMed

    García, Yedra; Callaway, Ragan M; Diaconu, Alecu; Montesinos, Daniel

    2013-01-01

    Differences in morphological or ecological traits expressed by exotic species between their native and non-native ranges are often interpreted as evidence for adaptation to new conditions in the non-native ranges. In turn this adaptation is often hypothesized to contribute to the successful invasion of these species. There is good evidence for rapid evolution by many exotic invasives, but the extent to which these evolutionary changes actually drive invasiveness is unclear. One approach to resolving the relationship between adaptive responses and successful invasion is to compare traits between populations from the native and non-native ranges for both exotic invaders and congeners that are exotic but not invasive. We compared a suite of morphological traits that are commonly tested in the literature in the context of invasion for three very closely related species of Centaurea, all of which are sympatric in the same native and non-native ranges in Europe and North America. Of these, C. solstitialis is highly invasive whereas C. calcitrapa and C. sulphurea are not. For all three species, plants from non-native populations showed similar shifts in key traits that have been identified in other studies as important putative adaptive responses to post-introduction invasion. For example, for all three species plants from populations in non-native ranges were (i) larger and (ii) produced seeds that germinated at higher rates. In fact, the non-invasive C. calcitrapa showed the strongest trait shift between ranges. Centaurea solstitialis was the only species for which plants from the non-native range increased allocation to defensive spines, and allocated proportionally less resources to reproduction, patterns contrary to what would be predicted by theory and other empirical studies to enhance invasion. Our results suggest caution when interpreting the commonly observed increase in size and reproductive capacity as factors that cause exotics to become invaders. PMID

  17. LESSons in minimally invasive urology.

    PubMed

    Dev, Harveer; Sooriakumaran, Prasanna; Tewari, Ashutosh; Rane, Abhay

    2011-05-01

    Since the introduction of laparoscopic surgery, the promise of lower postoperative morbidity and improved cosmesis has been achieved. LaparoEndoscopic Single Site (LESS) surgery potentially takes this further. Following the first human urological LESS report in 2007, numerous case series have emerged, as well as comparative studies comparing LESS with standard laparoscopy. Technological developments in instrumentation, access and optics devices are overcoming some of the challenges that are raised when operating through a single site. Further advances in the technique have included the incorporation of robotics (R-LESS), which exploit the ergonomic benefits of ex vivo robotic platforms in an attempt to further improve the implementation of LESS procedures. In the future, urologists may be able to benefit from in vivo micro-robots that will allow the manipulation of tissue from internal repositionable platforms. The use of magnetic anchoring and guidance systems (MAGS) might allow the external manoeuvring of intra-corporeal instruments to reduce clashing and facilitate triangulation. However, the final promise in minimally invasive surgery is natural orifice transluminal endoscopic surgery (NOTES), with its scarless technique. It remains to be seen whether NOTES, LESS, or any of these future developments will prove their clinical utility over standard laparoscopic methods.

  18. Dietary flexibility aids Asian earthworm invasion in North American forests.

    PubMed

    Zhang, Weixin; Hendrix, Paul F; Snyder, Bruce A; Molina, Marirosa; Li, Jianxiong; Rao, Xingquan; Siemann, Evan; Fu, Shenglei

    2010-07-01

    On a local scale, invasiveness of introduced species and invasibility of habitats together determine invasion success. A key issue in invasion ecology has been how to quantify the contribution of species invasiveness and habitat invasibility separately. Conventional approaches, such as comparing the differences in traits and/or impacts of species between native and/or invaded ranges, do not determine the extent to which the performance of invaders is due to either the effects of species traits or habitat characteristics. Here we explore the interaction between two of the most widespread earthworm invaders in the world (Asian Amynthas agrestis and European Lumbricus rubellus) and study the effects of species invasiveness and habitat invasibility separately through an alternative approach of "third habitat" in Tennessee, USA. We propose that feeding behaviors of earthworms will be critical to invasion success because trophic ecology of invasive animals plays a key role in the invasion process. We found that (1) the biomass and isotopic abundances (delta13C and delta15N) of A. agrestis were not impacted by either direct effects of L. rubellus competition or indirect effects of L. rubellus-preconditioned habitat; (2) A. agrestis disrupted the relationship between L. rubellus and soil microorganisms and consequently hindered litter consumption by L. rubellus; and (3) compared to L. rubellus, A. agrestis shifted its diet more readily to consume more litter, more soil gram-positive (G+) bacteria (which may be important for litter digestion), and more non-microbial soil fauna when soil microorganisms were depleted. In conclusion, A. agrestis showed strong invasiveness through its dietary flexibility through diet shifting and superior feeding behavior and its indirectly negative effect of habitat invasibility on L. rubellus via changes in the soil microorganism community. In such context, our results expand on the resource fluctuation hypothesis and support the superior

  19. Seed bank survival of an invasive species, but not of two native species, declines with invasion.

    PubMed

    Orrock, John L; Christopher, Cory C; Dutra, Humberto P

    2012-04-01

    Soil-borne seed pathogens may play an important role in either hindering or facilitating the spread of invasive exotic plants. We examined whether the invasive shrub Lonicera maackii (Caprifoliaceae) affected fungi-mediated mortality of conspecific and native shrub seeds in a deciduous forest in eastern Missouri. Using a combination of L. maackii removal and fungicide treatments, we found no effect of L. maackii invasion on seed viability of the native Symphoricarpos orbiculatus (Caprifoliaceae) or Cornus drummondii (Cornaceae). In contrast, fungi were significant agents of L. maackii seed mortality in invaded habitats. Losses of L. maackii to soil fungi were also significant in invaded habitats where L. maackii had been removed, although the magnitude of the effect of fungi was lower, suggesting that changes in soil chemistry or microhabitat caused by L. maackii were responsible for affecting fungal seed pathogens. Our work suggests that apparent competition via soil pathogens is not an important factor contributing to impacts of L. maackii on native shrubs. Rather, we found that fungal seed pathogens have density-dependent effects on L. maackii seed survival. Therefore, while fungal pathogens may provide little biotic resistance to early invasion by L. maackii, our study illustrates that more work is needed to understand how changes in fungal pathogens during the course of an invasion contribute to the potential for restoration of invaded systems. More generally, our study suggests that increased rates of fungal pathogen attack may be realized by invasive plants, such as L. maackii, that change the chemical or physical environment of the habitats they invade.

  20. Microvascular invasion in hepatocellular carcinoma

    PubMed Central

    Ünal, Emre; İdilman, İlkay Sedakat; Akata, Deniz; Özmen, Mustafa Nasuh; Karçaaltıncaba, Muşturay

    2016-01-01

    Microvascular invasion is a crucial histopathologic prognostic factor for hepatocellular carcinoma. We reviewed the literature and aimed to draw attention to clinicopathologic and imaging findings that may predict the presence of microvascular invasion in hepatocellular carcinoma. Imaging findings suggesting microvascular invasion are disruption of capsule, irregular tumor margin, peritumoral enhancement, multifocal tumor, increased tumor size, and increased glucose metabolism on positron emission tomography-computed tomography. In the presence of typical findings, microvascular invasion may be predicted. PMID:26782155

  1. [Pathogenesis of invasive fungal infections].

    PubMed

    Garcia-Vidal, Carolina; Carratalà, Jordi

    2012-03-01

    Invasive fungal infections remain a life-threatening disease. The development of invasive fungal disease is dependent on multiple factors, such us colonization and efficient host immune response. We aimed to review the pathogenesis of invasive fungal infections, in particular, those caused by Candida and Aspergillus. For this we propose, to describe the fungal characteristics, to detail the host defence mechanisms against fungus and to analyse the host risk factors for invasive fungal infection.

  2. Invasive species and climate change

    USGS Publications Warehouse

    Middleton, Beth A.

    2006-01-01

    Invasive species challenge managers in their work of conserving and managing natural areas and are one of the most serious problems these managers face. Because invasive species are likely to spread in response to changes in climate, managers may need to change their approaches to invasive species management accordingly.

  3. Genetic perspectives on marine biological invasions.

    PubMed

    Geller, Jonathan B; Darling, John A; Carlton, James T

    2010-01-01

    The extent to which the geographic distributions of marine organisms have been reshaped by human activities remains underappreciated, and so does, consequently, the impact of invasive species on marine ecosystems. The application of molecular genetic data in fields such as population genetics, phylogeography, and evolutionary biology have improved our ability to make inferences regarding invasion histories. Genetic methods have helped to resolve longstanding questions regarding the cryptogenic status of marine species, facilitated recognition of cryptic marine biodiversity, and provided means to determine the sources of introduced marine populations and to begin to recover the patterns of anthropogenic reshuffling of the ocean's biota. These approaches stand to aid materially in the development of effective management strategies and sustainable science-based policies. Continued advancements in the statistical analysis of genetic data promise to overcome some existing limitations of current approaches. Still other limitations will be best addressed by concerted collaborative and multidisciplinary efforts that recognize the important synergy between understanding the extent of biological invasions and coming to a more complete picture of both modern-day and historical marine biogeography.

  4. Evolutionary speed of species invasions.

    PubMed

    García-Ramos, Gisela; Rodríguez, Diego

    2002-04-01

    Successful invasion may depend of the capacity of a species to adjust genetically to a spatially varying environment. This research modeled a species invasion by examining the interaction between a quantitative genetic trait and population density. It assumed: (I) a quantitative genetic trait describes the adaptation of an individual to its local ecological conditions; (2) populations far from the local optimum grow more slowly than those near the optimum; and (3) the evolution of a trait depends on local population density, because differences in local population densities cause asymmetrical gene flow. This genetics-density interaction determined the propagation speed of populations. Numerical simulations showed that populations spread by advancing as two synchronic traveling waves, one for population density and one for trait adaptation. The form of the density wave was a step front that advances homogenizing populations at their carrying capacity; the adaptation wave was a curve with finite slope that homogenizes populations at full adaptation. The largest speed of population expansion, for a dimensionless analysis, corresponded to an almost homogeneous spatial environment when this model approached an ecological description such as the Fisher-Skellam's model. A large genetic response also favored faster speeds. Evolutionary speeds, in a natural scale, showed a wide range of rates that were also slower compared to models that only consider demographics. This evolutionary speed increased with high heritability, strong stabilizing selection, and high intrinsic growth rate. It decreased for steeper environmental gradients. Also indicated was an optimal dispersal rate over which evolutionary speed declined. This is expected because dispersal moves individuals further, but homogenizes populations genetically, making them maladapted. The evolutionary speed was compared to observed data. Furthermore, a moderate increase in the speed of expansion was predicted for

  5. Linking concepts in the ecology and evolution of invasive plants: network analysis shows what has been most studied and identifies knowledge gaps

    PubMed Central

    Vanderhoeven, Sonia; Brown, Cynthia S; Tepolt, Carolyn K; Tsutsui, Neil D; Vanparys, Valérie; Atkinson, Sheryl; Mahy, Grégory; Monty, Arnaud

    2010-01-01

    In recent decades, a growing number of studies have addressed connections between ecological and evolutionary concepts in biologic invasions. These connections may be crucial for understanding the processes underlying invaders’ success. However, the extent to which scientists have worked on the integration of the ecology and evolution of invasive plants is poorly documented, as few attempts have been made to evaluate these efforts in invasion biology research. Such analysis can facilitate recognize well-documented relationships and identify gaps in our knowledge. In this study, we used a network-based method for visualizing the connections between major aspects of ecology and evolution in the primary research literature. Using the family Poaceae as an example, we show that ecological concepts were more studied and better interconnected than were evolutionary concepts. Several possible connections were not documented at all, representing knowledge gaps between ecology and evolution of invaders. Among knowledge gaps, the concepts of plasticity, gene flow, epigenetics and human influence were particularly under-connected. We discuss five possible research avenues to better understand the relationships between ecology and evolution in the success of Poaceae, and of alien plants in general. PMID:25567919

  6. Linking concepts in the ecology and evolution of invasive plants: network analysis shows what has been most studied and identifies knowledge gaps.

    PubMed

    Vanderhoeven, Sonia; Brown, Cynthia S; Tepolt, Carolyn K; Tsutsui, Neil D; Vanparys, Valérie; Atkinson, Sheryl; Mahy, Grégory; Monty, Arnaud

    2010-03-01

    In recent decades, a growing number of studies have addressed connections between ecological and evolutionary concepts in biologic invasions. These connections may be crucial for understanding the processes underlying invaders' success. However, the extent to which scientists have worked on the integration of the ecology and evolution of invasive plants is poorly documented, as few attempts have been made to evaluate these efforts in invasion biology research. Such analysis can facilitate recognize well-documented relationships and identify gaps in our knowledge. In this study, we used a network-based method for visualizing the connections between major aspects of ecology and evolution in the primary research literature. Using the family Poaceae as an example, we show that ecological concepts were more studied and better interconnected than were evolutionary concepts. Several possible connections were not documented at all, representing knowledge gaps between ecology and evolution of invaders. Among knowledge gaps, the concepts of plasticity, gene flow, epigenetics and human influence were particularly under-connected. We discuss five possible research avenues to better understand the relationships between ecology and evolution in the success of Poaceae, and of alien plants in general.

  7. Invasive earthworms interact with abiotic conditions to influence the invasion of common buckthorn (Rhamnus cathartica).

    PubMed

    Roth, Alexander M; Whitfeld, Timothy J S; Lodge, Alexandra G; Eisenhauer, Nico; Frelich, Lee E; Reich, Peter B

    2015-05-01

    Common buckthorn (Rhamnus cathartica L.) is one of the most abundant and ecologically harmful non-native plants in forests of the Upper Midwest United States. At the same time, European earthworms are invading previously glaciated areas in this region, with largely anecdotal evidence suggesting they compound the negative effects of buckthorn and influence the invasibility of these forests. Germination and seedling establishment are important control points for colonization by any species, and manipulation of the conditions influencing these life history stages may provide insight into why invasive species are successful in some environments and not others. Using a greenhouse microcosm experiment, we examined the effects of important biotic and abiotic factors on the germination and seedling establishment of common buckthorn. We manipulated light levels, leaf litter depth and earthworm presence to investigate the independent and interactive effects of these treatments on buckthorn establishment. We found that light and leaf litter depth were significant predictors of buckthorn germination but that the presence of earthworms was the most important factor; earthworms interacted with light and leaf litter to increase the number and biomass of buckthorn across all treatments. Path analysis suggested both direct and moisture-mediated indirect mechanisms controlled these processes. The results suggest that the action of earthworms may provide a pathway through which buckthorn invades forests of the Upper Midwest United States. Hence, researchers and managers should consider co-invasion of plants and earthworms when investigating invasibility and creating preemptive or post-invasion management plans.

  8. Impacts of invasive plants on resident animals across ecosystems, taxa, and feeding types: a global assessment.

    PubMed

    Schirmel, Jens; Bundschuh, Mirco; Entling, Martin H; Kowarik, Ingo; Buchholz, Sascha

    2016-02-01

    As drivers of global change, biological invasions have fundamental ecological consequences. However, it remains unclear how invasive plant effects on resident animals vary across ecosystems, animal classes, and functional groups. We performed a comprehensive meta-analysis covering 198 field and laboratory studies reporting a total of 3624 observations of invasive plant effects on animals. Invasive plants had reducing (56%) or neutral (44%) effects on animal abundance, diversity, fitness, and ecosystem function across different ecosystems, animal classes, and feeding types while we could not find any increasing effect. Most importantly, we found that invasive plants reduced overall animal abundance, diversity and fitness. However, this significant overall effect was contingent on ecosystems, taxa, and feeding types of animals. Decreasing effects of invasive plants were most evident in riparian ecosystems, possibly because frequent disturbance facilitates more intense plant invasions compared to other ecosystem types. In accordance with their immediate reliance on plants for food, invasive plant effects were strongest on herbivores. Regarding taxonomic groups, birds and insects were most strongly affected. In insects, this may be explained by their high frequency of herbivory, while birds demonstrate that invasive plant effects can also cascade up to secondary consumers. Since data on impacts of invasive plants are rather limited for many animal groups in most ecosystems, we argue for overcoming gaps in knowledge and for a more differentiated discussion on effects of invasive plant on native fauna.

  9. Modeling Hawaiian ecosystem degradation due to invasive plants under current and future climates

    USGS Publications Warehouse

    Vorsino, Adam E.; Fortini, Lucas B.; Amidon, Fred A.; Miller, Stephen E.; Jacobi, James D.; Price, Jonathan P.; `Ohukani`ohi`a Gon, Sam; Koob, Gregory A.

    2014-01-01

    Occupation of native ecosystems by invasive plant species alters their structure and/or function. In Hawaii, a subset of introduced plants is regarded as extremely harmful due to competitive ability, ecosystem modification, and biogeochemical habitat degradation. By controlling this subset of highly invasive ecosystem modifiers, conservation managers could significantly reduce native ecosystem degradation. To assess the invasibility of vulnerable native ecosystems, we selected a proxy subset of these invasive plants and developed robust ensemble species distribution models to define their respective potential distributions. The combinations of all species models using both binary and continuous habitat suitability projections resulted in estimates of species richness and diversity that were subsequently used to define an invasibility metric. The invasibility metric was defined from species distribution models with 0.8; True Skill Statistic >0.75) as evaluated per species. Invasibility was further projected onto a 2100 Hawaii regional climate change scenario to assess the change in potential habitat degradation. The distribution defined by the invasibility metric delineates areas of known and potential invasibility under current climate conditions and, when projected into the future, estimates potential reductions in native ecosystem extent due to climate-driven invasive incursion. We have provided the code used to develop these metrics to facilitate their wider use (Code S1). This work will help determine the vulnerability of native-dominated ecosystems to the combined threats of climate change and invasive species, and thus help prioritize ecosystem and species management actions.

  10. [Robot-assisted minimally invasive esophagectomy. German version].

    PubMed

    van Hillegersberg, R; Seesing, M F J; Brenkman, H J F; Ruurda, J P

    2016-08-01

    Esophagolymphadenectomy is the cornerstone of multimodality treatment for resectable esophageal cancer. The preferred surgical approach is transthoracic, with a two-field lymph node dissection and gastric conduit reconstruction. A minimally invasive approach has been shown to reduce postoperative complications and increase quality of life. Robot-assisted minimally invasive esophagectomy (RAMIE) was developed to facilitate this complex thoracoscopic procedure. RAMIE has been shown to be safe with good oncologic results and reduced morbidity. The use of RAMIE opens new indications for curative surgery in patients with T4b tumors, high mediastinal tumors, and lymph node metastases after neoadjuvant treatment. PMID:27484825

  11. Effects of bryophytes on succession from alkaline marsh to Sphagnum bog

    SciTech Connect

    Glime, J.M.; Wetzel, R.G.; Kennedy, B.J.

    1982-10-01

    The alkaline eastern marsh of Lawrence Lake, a marl lake in southwestern Michigan, was sampled by randomly placed line transects to determine the bryophyte cover and corresponding vascular plant zones. Cluster analysis indicated three distinct bryophyte zones which correspond with the recognized vascular plant zones. Mosses occupied over 50% of the surface in some areas. Invasion of Sphagnum, vertical zonation of the mosses on hummocks, zonation with distance from the lake, the abundance of non-Sphagnum moss hummocks, and the ability of the non-Sphagnum species to lower the pH of marsh water during laboratory incubations are evidence that non-Sphagnum mosses facilitate succession from alkaline marsh to Sphagnum bog.

  12. High School Facilitators and Inhibitors.

    ERIC Educational Resources Information Center

    Gnagey, William J.

    1981-01-01

    Teachers in a small high school nominated students whose classroom behavior facilitates or inhibits (disrupts) the learning process. These two groups were compared on locus of control, Maslow motive hierarchies, attitudes toward crime prevention, and achievement. Results are discussed and suggestions for helping disruptive students are made. (SJL)

  13. Sign Facilitation in Word Recognition.

    ERIC Educational Resources Information Center

    Wauters, Loes N.; Knoors, Harry E. T.; Vervloed, Mathijs P. J.; Aarnoutse, Cor A. J.

    2001-01-01

    This study examined whether use of sign language would facilitate reading word recognition by 16 deaf children (6- to 1 years-old) in the Netherlands. Results indicated that if words were learned through speech, accompanied by the relevant sign, accuracy of word recognition was greater than if words were learned solely through speech. (Contains…

  14. Producing Gestures Facilitates Route Learning

    PubMed Central

    So, Wing Chee; Ching, Terence Han-Wei; Lim, Phoebe Elizabeth; Cheng, Xiaoqin; Ip, Kit Yee

    2014-01-01

    The present study investigates whether producing gestures would facilitate route learning in a navigation task and whether its facilitation effect is comparable to that of hand movements that leave physical visible traces. In two experiments, we focused on gestures produced without accompanying speech, i.e., co-thought gestures (e.g., an index finger traces the spatial sequence of a route in the air). Adult participants were asked to study routes shown in four diagrams, one at a time. Participants reproduced the routes (verbally in Experiment 1 and non-verbally in Experiment 2) without rehearsal or after rehearsal by mentally simulating the route, by drawing it, or by gesturing (either in the air or on paper). Participants who moved their hands (either in the form of gestures or drawing) recalled better than those who mentally simulated the routes and those who did not rehearse, suggesting that hand movements produced during rehearsal facilitate route learning. Interestingly, participants who gestured the routes in the air or on paper recalled better than those who drew them on paper in both experiments, suggesting that the facilitation effect of co-thought gesture holds for both verbal and nonverbal recall modalities. It is possibly because, co-thought gesture, as a kind of representational action, consolidates spatial sequence better than drawing and thus exerting more powerful influence on spatial representation. PMID:25426624

  15. Producing gestures facilitates route learning.

    PubMed

    So, Wing Chee; Ching, Terence Han-Wei; Lim, Phoebe Elizabeth; Cheng, Xiaoqin; Ip, Kit Yee

    2014-01-01

    The present study investigates whether producing gestures would facilitate route learning in a navigation task and whether its facilitation effect is comparable to that of hand movements that leave physical visible traces. In two experiments, we focused on gestures produced without accompanying speech, i.e., co-thought gestures (e.g., an index finger traces the spatial sequence of a route in the air). Adult participants were asked to study routes shown in four diagrams, one at a time. Participants reproduced the routes (verbally in Experiment 1 and non-verbally in Experiment 2) without rehearsal or after rehearsal by men