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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. 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

  3. 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

  4. Predicting invasion success in complex ecological networks

    PubMed Central

    Romanuk, Tamara N.; Zhou, Yun; Brose, Ulrich; Berlow, Eric L.; Williams, Richard J.; Martinez, Neo D.

    2009-01-01

    A central and perhaps insurmountable challenge of invasion ecology is to predict which combinations of species and habitats most effectively promote and prevent biological invasions. Here, we integrate models of network structure and nonlinear population dynamics to search for potential generalities among trophic factors that may drive invasion success and failure. We simulate invasions where 100 different species attempt to invade 150 different food webs with 15–26 species and a wide range (0.06–0.32) of connectance. These simulations yield 11 438 invasion attempts by non-basal species, 47 per cent of which are successful. At the time of introduction, whether or not the invader is a generalist best predicts final invasion success; however, once the invader establishes itself, it is best distinguished from unsuccessful invaders by occupying a lower trophic position and being relatively invulnerable to predation. In general, variables that reflect the interaction between an invading species and its new community, such as generality and trophic position, best predict invasion success; however, for some trophic categories of invaders, fundamental species traits, such as having the centre of the feeding range low on the theoretical niche axis (for non-omnivorous and omnivorous herbivores), or the topology of the food web (for tertiary carnivores), best predict invasion success. Across all invasion scenarios, a discriminant analysis model predicted successful and failed invasions with 76.5 per cent accuracy for properties at the time of introduction or 100 per cent accuracy for properties at the time of establishment. More generally, our results suggest that tackling the challenge of predicting the properties of species and habitats that promote or inhibit invasions from food web perspective may aid ecologists in identifying rules that govern invasions in natural ecosystems. PMID:19451125

  5. 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...

  6. 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

  7. The influence of numbers on invasion success.

    PubMed

    Blackburn, Tim M; Lockwood, Julie L; Cassey, Phillip

    2015-05-01

    The process by which a species becomes a biological invader, at a location where it does not naturally occur, can be divided into a series of sequential stages (transport, introduction, establishment and spread). A species' success at passing through each of these stages depends, in a large part, on the number of individuals available to assist making each transition. Here, we review the evidence that numbers determine success at each stage of the invasion process and then discuss the likely mechanisms by which numbers affect success. We conclude that numbers of individuals affect transport and introduction by moderating the likelihood that abundant (and widespread) species are deliberately or accidentally translocated; affect establishment success by moderating the stochastic processes (demographic, environmental, genetic or Allee) to which small, introduced populations will be vulnerable; and affect invasive spread most likely because of persistent genetic effects determined by the numbers of individuals involved in the establishment phase. We finish by suggesting some further steps to advance our understanding of the influence of numbers on invasion success, particularly as they relate to the genetics of the process. PMID:25641210

  8. The Role of Facilitative Interactions in Tree Invasions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Many Ecologists studying the invasion biology of exotic plants have adopted the Gleasonian view that plant communities are primarily structured by competitive individualistic interactions and interdependent interactions (i.e. facilitation) are absent or limited (e.g. Bruno et al., 2005). However, s...

  9. Mild Traumatic Brain Injury: Facilitating School Success.

    ERIC Educational Resources Information Center

    Hux, Karen; Hacksley, Carolyn

    1996-01-01

    A case study is used to demonstrate the effects of mild traumatic brain injury on educational efforts. Discussion covers factors complicating school reintegration, ways to facilitate school reintegration, identification of cognitive and behavioral consequences, minimization of educators' discomfort, reintegration program design, and family…

  10. Community Building: Facilitating Successful Online Courses.

    ERIC Educational Resources Information Center

    McSporran, Mae; Young, Stuart

    It is important to build a community of learners so that cooperative learning takes place. This is more difficult to accomplish online, where the lecturer has to overcome the natural reticence of students to post in shared class spaces. This paper suggests contructive methods of ensuring the success of an online course. These include: (1)…

  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. PMID:12422019

  12. 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

  13. 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

  14. 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

  15. The role of life history traits in mammalian invasion success.

    PubMed

    Capellini, Isabella; Baker, Joanna; Allen, William L; Street, Sally E; Venditti, Chris

    2015-10-01

    Why some organisms become invasive when introduced into novel regions while others fail to even establish is a fundamental question in ecology. Barriers to success are expected to filter species at each stage along the invasion pathway. No study to date, however, has investigated how species traits associate with success from introduction to spread at a large spatial scale in any group. Using the largest data set of mammalian introductions at the global scale and recently developed phylogenetic comparative methods, we show that human-mediated introductions considerably bias which species have the opportunity to become invasive, as highly productive mammals with longer reproductive lifespans are far more likely to be introduced. Subsequently, greater reproductive output and higher introduction effort are associated with success at both the establishment and spread stages. High productivity thus supports population growth and invasion success, with barriers at each invasion stage filtering species with progressively greater fecundity. PMID:26293900

  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. Use of dexmedetomidine to facilitate non-invasive ventilation

    PubMed Central

    DeMuro, Jonas P; Mongelli, Michael N; Hanna, Adel F

    2013-01-01

    Patients with chronic obstructive pulmonary disease and congestive heart failure exacerbations, as well as pneumonia benefit from the use of non-invasive ventilation (NIV), due to increased patient comfort and a reduced incidence of ventilator-associated pneumonia. However, some patients do not tolerate NIV due to anxiety or agitation, and traditionally physicians have withheld sedation from these patients due to concerns of loss of airway protection and respiratory depression. We report our recent experience with a 91-year-old female who received NIV for acute respiratory distress secondary to pneumonia. The duration of NIV was a total time period of 86 h, using the bilevel positive airway pressure mode via a full face mask. The patient was initially agitated with the NIV, but with the addition of the dexmedetomidine, she tolerated it well. The dexmedetomidine was administered without a loading dose, as a continuous infusion ranging from 0.2 to 0.5 mcg/kg/hr, titrated to a Ramsey score of three. This case illustrates the safe use of dexmedetomidine to facilitate NIV, and improve compliance, which may reduce ICU length of stay. PMID:24459626

  18. Increased snow facilitates plant invasion in mixed grass prairie

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Although global change is known to influence plant invasion, relatively little is known about interactions between altered precipitation and invasion. In the North American Mixedgrass prairie, invasive species are often abundant in wet and nitrogen rich areas, suggesting that predicted changes in pr...

  19. Cane Toads on Cowpats: Commercial Livestock Production Facilitates Toad Invasion in Tropical Australia

    PubMed Central

    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

  20. Increased snow facilitates plant invasion in mixedgrass prairie.

    PubMed

    Blumenthlal, D; Chimner, R A; Welker, J M; Morgan, J A

    2008-07-01

    Although global change is known to influence plant invasion, little is known about interactions between altered precipitation and invasion. In the North American mixedgrass prairie, invasive species are often abundant in wet and nitrogen (N)-rich areas, suggesting that predicted changes in precipitation and N deposition could exacerbate invasion. Here, this possibility was tested by seeding six invasive species into experimental plots of mixedgrass prairie treated with a factorial combination of increased snow, summer irrigation, and N addition. Without added snow, seeded invasive species were rarely observed. Snow addition increased average above-ground biomass of Centaurea diffusa from 0.026 to 66 g m(-2), of Gypsophila paniculata from 0.1 to 7.3 g m(-2), and of Linaria dalmatica from 5 to 101 g m(-2). Given added snow, summer irrigation increased the density of G. paniculata, and N addition increased the density and biomass of L. dalmatica. Plant density responses mirrored those of plant biomass, indicating that increases in biomass resulted, in part, from increases in recruitment. In contrast to seeded invasive species, resident species did not respond to snow addition. These results suggest that increases in snowfall or variability of snowfall may exacerbate forb invasion in the mixedgrass prairie. PMID:19086291

  1. 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

  2. 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

  3. 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

  4. 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

  5. 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...

  6. 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

  7. 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

  8. 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.

  9. 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

  10. 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

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

    PubMed

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

    2013-02-01

    challenges associated with context-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. PMID:23691655

  12. 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.

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

    PubMed Central

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

    2014-01-01

    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. PMID:24938305

  14. Mapping for Success: Mapping and Aligning the Curriculum To Improve Student Learning. A Guide for Facilitators

    ERIC Educational Resources Information Center

    Jensen, Jennifer L.; Sowers, Jayne

    2005-01-01

    Mapping for Success: Mapping and Aligning the Curriculum To Improve Student Learning, A Guide for Facilitators serves as both a training manual for future mapping facilitators and a facilitator?s primary resource for implementing the mapping process in a school. In the mapping process, teachers outline, analyze, and change a school?s curriculum…

  15. 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

  16. 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

  17. Successful approaches for battling invasive species in developed countries

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Biological invasions increasingly threaten natural resources and reduce biological diversity worldwide. To curtail biological invasions, developed countries have adopted multitire approaches that systematically address the process of invasion, encompassing introduction, establishment, spread and nat...

  18. 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.

  19. 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

  20. 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

  1. The cell surface GRP78 facilitates the invasion of hepatocellular carcinoma cells.

    PubMed

    Zhang, Xiu-Xiu; Li, Hong-Dan; Zhao, Song; Zhao, Liang; Song, Hui-Juan; Wang, Guan; Guo, Qing-Jun; Luan, Zhi-Dong; Su, Rong-Jian

    2013-01-01

    Invasion is a major characteristic of hepatocellular carcinoma and one of the main causes of refractory to treatment. We have previously reported that GRP78 promotes the invasion of hepatocellular carcinoma although the mechanism underlying this change remains uncertain. In this paper, we explored the role of the cell surface GRP78 in the regulation of cancer cell invasion in hepatocellular carcinoma cells. We found that neutralization of the endogenous cell surface GRP78 with the anti-GRP78 antibody inhibited the adhesion and invasion in hepatocellular carcinoma cell lines Mahlavu and SMMC7721. However, forced expression of the cell surface GRP78 facilitated the adhesion and invasion in SMMC7721. We further demonstrated that inhibition of the endogenous cell surface GRP78 specifically inhibited the secretion and activity of MMP-2 but did not affect the secretion and activity of MMP-9. We also found that inhibition of the cell surface GRP78 increased E-Cadherin expression and decreased N-Cadherin level. On the contrary, forced expression of the cell surface GRP78 increased N-Cadherin expression and decreased E-Cadherin level, suggesting that the cell surface GRP78 plays critical role in the regulation of EMT process. These findings suggest that the cell surface GRP78 plays a stimulatory role in the invasion process and may be a potential anti-invasion target for the treatment of hepatocellular carcinoma. PMID:24383061

  2. Strategies the facilitate academic success of nursing students in HBCU's.

    PubMed

    Sheffler, S J

    1997-01-01

    Attrition of nursing students is a problem in nursing programs across the country and is not limited solely to programs in historically Black Colleges and Universities (HBCUs). This article will describe some of the strategies utilized by nursing faculty in one HBCU to assist students in overcoming barriers that inhibit their academic success. PMID:9460305

  3. Rapid adaptation to climate facilitates range expansion of an invasive plant.

    PubMed

    Colautti, Robert I; Barrett, Spencer C H

    2013-10-18

    Adaptation to climate, evolving over contemporary time scales, could facilitate rapid range expansion across environmental gradients. Here, we examine local adaptation along a climatic gradient in the North American invasive plant Lythrum salicaria. We show that the evolution of earlier flowering is adaptive at the northern invasion front where it increases fitness as much as, or more than, the effects of enemy release and the evolution of increased competitive ability. However, early flowering decreases investment in vegetative growth, which reduces fitness by a factor of 3 in southern environments where the North American invasion commenced. Our results demonstrate that local adaptation can evolve quickly during range expansion, overcoming environmental constraints on propagule production. PMID:24136968

  4. Empirical Evaluation of a Forecasting Model for Successful Facilitation in Telematic Learning Programmes.

    ERIC Educational Resources Information Center

    Bisschoff, A.; Bisschoff, C. A.

    2002-01-01

    Potchefstroom University for Christian Higher Education evaluated the usefulness of a model created to predict the success of distance education course facilitators. The model identified eight key attributes based on performance measures from the 1999 Facilitator Customer Service Survey. The evaluation accredited the model while suggesting…

  5. 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.

  6. Differences in evolutionary history translate into differences in invasion success of alien mammals in South Africa

    PubMed Central

    Yessoufou, Kowiyou; Gere, Jephris; Daru, Barnabas H; van der Bank, Michelle

    2014-01-01

    Attempts to investigate the drivers of invasion success are generally limited to the biological and evolutionary traits distinguishing native from introduced species. Although alien species introduced to the same recipient environment differ in their invasion intensity – for example, some are “strong invaders”; others are “weak invaders” – the factors underlying the variation in invasion success within alien communities are little explored. In this study, we ask what drives the variation in invasion success of alien mammals in South Africa. First, we tested for taxonomic and phylogenetic signal in invasion intensity. Second, we reconstructed predictive models of the variation in invasion intensity among alien mammals using the generalized linear mixed-effects models. We found that the family Bovidae and the order Artiodactyla contained more “strong invaders” than expected by chance, and that such taxonomic signal did not translate into phylogenetic selectivity. In addition, our study indicates that latitude, gestation length, social group size, and human population density are only marginal determinant of the variation in invasion success. However, we found that evolutionary distinctiveness – a parameter characterising the uniqueness of each alien species – is the most important predictive variable. Our results indicate that the invasive behavior of alien mammals may have been “fingerprinted” in their evolutionary past, and that evolutionary history might capture beyond ecological, biological and life-history traits usually prioritized in predictive modeling of invasion success. These findings have applicability to the management of alien mammals in South Africa. PMID:25360253

  7. 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.

  8. 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

  9. 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

  10. 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

  11. 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. PMID:25184224

  12. Positive Feedback between Mycorrhizal Fungi and Plants Influences Plant Invasion Success and Resistance to Invasion

    PubMed Central

    Zhang, Qian; Yang, Ruyi; Tang, Jianjun; Yang, Haishui; Hu, Shuijin; Chen, Xin

    2010-01-01

    Negative or positive feedback between arbuscular mycorrhizal fungi (AMF) and host plants can contribute to plant species interactions, but how this feedback affects plant invasion or resistance to invasion is not well known. Here we tested how alterations in AMF community induced by an invasive plant species generate feedback to the invasive plant itself and affect subsequent interactions between the invasive species and its native neighbors. We first examined the effects of the invasive forb Solidago canadensis L. on AMF communities comprising five different AMF species. We then examined the effects of the altered AMF community on mutualisms formed with the native legume forb species Kummerowia striata (Thunb.) Schindl. and on the interaction between the invasive and native plants. The host preferences of the five AMF were also assessed to test whether the AMF form preferred mutualistic relations with the invasive and/or the native species. We found that S. canadensis altered AMF spore composition by increasing one AMF species (Glomus geosporum) while reducing Glomus mosseae, which is the dominant species in the field. The host preference test showed that S. canadensis had promoted the abundance of AMF species (G. geosporum) that most promoted its own growth. As a consequence, the altered AMF community enhanced the competitiveness of invasive S. canadensis at the expense of K. striata. Our results demonstrate that the invasive S. canadensis alters soil AMF community composition because of fungal-host preference. This change in the composition of the AMF community generates positive feedback to the invasive S. canadensis itself and decreases AM associations with native K. striata, thereby making the native K. striata less dominant. PMID:20808770

  13. 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

  14. 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.

  15. 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…

  16. Invasive Cane Toads: Social Facilitation Depends upon an Individual’s Personality

    PubMed Central

    González-Bernal, Edna; Brown, Gregory P.; Shine, Richard

    2014-01-01

    Individual variation in behavioural traits (including responses to social cues) may influence the success of invasive populations. We studied the relationship between sociality and personality in invasive cane toads (Rhinella marina) from a recently established population in tropical Australia. In our field experiments, we manipulated social cues (the presence of a feeding conspecific) near a food source. We captured and compared toads that only approached feeding sites where another toad was already present, with conspecifics that approached unoccupied feeding sites. Subsequent laboratory trials showed correlated personality differences (behavioural syndromes) between these two groups of toads. For example, toads that approached already-occupied rather than unoccupied feeding sites in the field, took longer to emerge from a shelter-site in standardized trials, suggesting these individuals are ‘shy’ (whereas toads that approached unoccupied feeding stations tended to be ‘bold’). Manipulating hunger levels did not abolish this difference. In feeding trials, a bold toad typically outcompeted a shy toad under conditions of low prey availability, but the outcome was reversed when multiple prey items were present. Thus, both personality types may be favored under different circumstances. This invasive population of toads contains individuals that exhibit a range of personalities, hinting at the existence of a wide range of social dynamics in taxa traditionally considered to be asocial. PMID:25033047

  17. The effects of phylogenetic relatedness on invasion success and impact: deconstructing Darwin's naturalisation conundrum.

    PubMed

    Li, Shao-Peng; Cadotte, Marc W; Meiners, Scott J; Hua, Zheng-Shuang; Shu, Hao-Yue; Li, Jin-Tian; Shu, Wen-Sheng

    2015-12-01

    Darwin's naturalisation conundrum describes the paradox that the relatedness of exotic species to native residents could either promote or hinder their success through opposing mechanisms: niche pre-adaptation or competitive interactions. Previous studies focusing on single snapshots of invasion patterns have provided support to both sides of the conundrum. Here, by examining invasion dynamics of 480 plots over 40 years, we show that exotic species more closely related to native species were more likely to enter, establish and dominate the resident communities, and that native residents more closely related to these successful exotics were more likely to go locally extinct. Therefore, non-random displacement of natives during invasion could weaken or even reverse the negative effects of exotic-native phylogenetic distances on invasion success. The scenario that exotics more closely related to native residents are more successful, but tend to eliminate their closely related natives, may help to reconcile the 150-year-old conundrum. PMID:26437879

  18. International Adoption: Strategies in Early Childhood Classrooms To Help Facilitate Success. Developmentally Appropriate Practice.

    ERIC Educational Resources Information Center

    Caro, Patricia; Ogunnaike, Oluyomi

    2001-01-01

    Describes developmental interventions, attachment issues, curricular ideas, and nutritional considerations that can facilitate successful integration into U.S. early childhood environments of children adopted from overseas. Asserts that early childhood educators can nurture adopted children's development by arranging a conducive environment,…

  19. Release from herbivory does not confer invasion success for Eugenia uniflora in Florida.

    PubMed

    Bohl Stricker, Kerry; Stiling, Peter

    2014-03-01

    One of the most commonly cited hypotheses explaining invasion success is the enemy release hypothesis (ERH), which maintains that populations are regulated by coevolved natural enemies where they are native but are relieved of this pressure in the new range. However, the role of resident enemies in plant invasion remains unresolved. We conducted a field experiment to test predictions of the ERH empirically using a system of native, introduced invasive, and introduced non-invasive Eugenia congeners in south Florida. Such experiments are rarely undertaken but are particularly informative in tests of the ERH, as they simultaneously identify factors allowing invasive species to replace natives and traits determining why most introduced species are unsuccessful invaders. We excluded insect herbivores from seedlings of Eugenia congeners where the native and invasive Eugenia co-occur, and compared how herbivore exclusion affected foliar damage, growth, and survival. We found no evidence to support the ERH in this system, instead finding that the invasive E. uniflora sustained significantly more damage than the native and introduced species. Interestingly, E. uniflora performed better than, or as well as, its congeners in terms of growth and survival, in spite of higher damage incidence. Further, although herbivore exclusion positively influenced Eugenia seedling survival, there were few differences among species and no patterns in regard to invasion status or origin. We conclude that the ability of E. uniflora to outperform its native and introduced non-invasive congeners, and not release from insect herbivores, contributes to its success as an invader in Florida. PMID:24141380

  20. 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

  1. 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

  2. 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

  3. 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.

  4. UNDERSTANDING THE ROLE OF CLIMATE CHANGE AND LAND USE MODIFICATIONS IN FACILITATING PATHOGEN INVASIONS AND DECLINES OF ECTOTHERMS

    EPA Science Inventory

    We expect to reveal general mechanisms by which climate change and specific land use modifications facilitate parasite invasions. This will enhance risk assessment and management by allowing decision makers to prioritize regions, localities, and species that are at risk for po...

  5. 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

  6. 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

  7. 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

  8. 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

  9. 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

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

    PubMed Central

    MacNeil, Calum; Dick, Jaimie T. A.

    2014-01-01

    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. PMID:25122739

  11. 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

  12. Hard traits of three Bromus species in their source area explain their current invasive success

    NASA Astrophysics Data System (ADS)

    Fenesi, Annamária; Rédei, Tamás; Botta-Dukát, Zoltán

    2011-09-01

    We address two highly essential question using three Eurasian Bromus species with different invasion success in North America as model organisms: (1) why some species become invasive and others do not, and (2) which traits can confer pre-adaptation for species to become invasive elsewhere. While the morphology and phenology of the chosen bromes ( Bromus tectorum, Bromus sterilis and Bromus squarrosus) are highly similar, we measured complex traits often associated with invasive success: phenotypic plasticity, competitive ability and generalist-specialist character. We performed common-garden experiments, community- and landscape-level surveys in areas of co-occurrence in Central Europe (Hungary) that could have served as donor region for American introductions. According to our results, the three bromes are unequally equipped with trait that could enhance invasiveness. B. tectorum possesses several traits that may be especially relevant: it has uniquely high phenotypic plasticity, as demonstrated in a nitrogen addition experiment, and it is a habitat generalist, thriving in a wide range of habitats, from semi-natural to degraded ones, and having the widest co-occurrence based niche-breadth. The strength of B. sterilis lies in its ability to use resources unexploited by other species. It can become dominant, but only in one non-natural habitat type, namely the understorey of the highly allelopathic stands of the invasive Robinia pseudoacacia. B. squarrosus is a habitat specialist with low competitive ability, always occurring with low coverage. This ranking of the species' abilities can explain the current spreading success of the three bromes on the North American continent, and highlight the high potential of prehistoric invaders (European archaeophytes) to become invasive elsewhere.

  13. 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

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

    PubMed Central

    Piiroinen, Saija; Lyytinen, Anne; Lindström, Leena

    2013-01-01

    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

  15. 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

  16. 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...

  17. 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

  18. The Warden procedure can be successfully performed using minimally invasive cardiac surgery without aortic clamping.

    PubMed

    Zubritskiy, Alexey; Arkhipov, Alexey; Khapaev, Timur; Naberukhin, Yuriy; Omelchenko, Alexander; Gorbatykh, Yuriy; Bogachev-Prokophiev, Alexander; Karaskov, Alexander

    2016-02-01

    Currently, minimally invasive cardiac surgery has found widespread use even in congenital heart surgery. The number of defects, which can be corrected through a small incision or totally endoscopic, is on the rise. Nowadays, surgeons can repair atrial septal defect, ventricular septal defect, patent ductus arteriosus and other congenital heart defects using minimally invasive techniques. In this paper, we report 21 cases of successful repair of supracardiac partial anomalous right upper and middle pulmonary venous connection, using the Warden procedure. It was performed in children through the right-sided midaxillary thoracotomy with direct cardiopulmonary bypass cannulation and induction of ventricular fibrillation. There were no operative or early postoperative deaths or complications. All patients were in sinus rhythm at discharge. According to echocardiography, there were no cases of early SVC or pulmonary veins narrowing. The Warden procedure can be performed safely and efficiently using the minimally invasive cardiac surgery. PMID:26541958

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

    PubMed Central

    Knop, Eva; Reusser, Nik

    2012-01-01

    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. PMID:23015630

  20. 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. PMID:20857771

  1. 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. PMID:26236909

  2. Successful treatment of rectal cancer with perineal invasion: Three case reports

    PubMed Central

    KITAHARA, TOMOHIRO; UEMURA, MAMORU; HARAGUCHI, NAOTSUGU; NISHIMURA, JUNICHI; SHINGAI, TATSUSHI; HATA, TAISHI; TAKEMASA, ICHIRO; MIZUSHIMA, TSUNEKAZU; DOKI, YUICHIRO; MORI, MASAKI; YAMAMOTO, HIROFUMI

    2014-01-01

    Rectal cancer occasionally invades adjacent organs. However, rectal cancer with perineal invasion is uncommon and difficult to treat. Locally advanced colorectal cancer may be clinically treated with neoadjuvant therapy, followed by en bloc resection. Skin invasion may lead to tumor dissemination via cutaneous blood flow and lymphatic routes. There is currently no firm evidence regarding the treatment of these significantly advanced rectal cancers. In this study, we report 3 cases of rectal cancer with perineal invasion, successfully managed by multimodality treatment. Case 1 is a 52-year-old man with rectal cancer that had invaded the perineum; case 2 is a 38-year-old man with rectal cancer infiltrating the perineal skin and liver metastasis; and case 3 is a 50-year-old woman with rectal cancer and perineal invasion. All the cases were treated with radical excision. No severe complications were observed in the perioperative period. Case 2, in particular, was confirmed to remain alive 5 years after the surgery. Our experience suggests that multimodality treatment, including extended radical surgery, may be a feasible approach to the treatment of rectal cancer with perineal skin invasion. PMID:24940483

  3. Habitat structure determines competition intensity and invasion success in gecko lizards.

    PubMed

    Petren, K; Case, T J

    1998-09-29

    Species diversity is correlated with structural complexity in many animal communities; however, experimental tests of the mechanisms underlying this important relationship are rare, especially in terrestrial communities. We manipulated physical features of the habitat of gecko lizards and measured the effect on exploitation competition for insects. Increasing both the dispersion of food resources and microhabitat topography dramatically reduced interspecific competition. Adding topographic structure reduced the advantages of the larger, faster, invasive species. Interindividual spacing decreased, but intraspecific agonistic interference increased in the more territorial, resident species. Human structural alterations of the environment facilitate invasion and competitive displacement in this system. Physical microhabitat structure can potentially affect species interactions through a variety of complex mechanisms. PMID:9751735

  4. Broader Impact Actualized: Collaborative Efforts that Facilitate Successful Movement of Underrepresented Students Through the Pipeline

    NASA Astrophysics Data System (ADS)

    Pyrtle, A. J.; Whitney, V. W.

    2007-12-01

    The Minorities Striving and Pursuing Higher Degrees of Success in Earth System Science Initiative \\(MS PHD'S)\\ was established by and for underrepresented minorities to facilitate increased and sustained participation in Earth system science community. Based on successful experiences of students within the SOARS program, the MS PHD'S 2003 pilot project incorporated a team mentoring structure. Student interaction with multiple mentors resulted in exposure to multiple learning perspectives and increased one-on-one, mentee/mentor interaction. Since program inception, eleven \\(11)\\ minority Earth system scientists have served as Program mentors and eighty-two (82) minority and non-minority scientists have served as Meeting Mentors to MS PHD'S student participants A total of ninety-nine \\(99)\\ undergraduate and graduate students from underrepresented populations have participated in the MS PHD'S program. Twenty-five undergraduate and graduate students participated in the MS PHD'S pilot program in 2003 as Cohort I. During FY 04-05, Cohort II consisted of twenty-seven students and twenty-three students formed Cohort III. FY 06-07, twenty-four (24) students formed Cohort IV. Of the ninety-nine \\(99)\\ student participants, fifty-four \\(54)\\ MS PHD'S student participants self-identified as African American, twenty-seven \\(27)\\ as Puerto Rican, six \\(6)\\ as Hispanic/Mexican American, eight \\(8)\\ as Native American and one \\(1)\\ each as African, Asian, Pacific Islander and Multi-Ethnic. During the five \\(5)\\ year span of MS PHD'S programming, fourteen \\(14)\\ student participants completed BS degrees, ten (10) completed MS degrees and seven \\(7\\ completed the Doctoral degrees. How did MS PHD'S establish meaningful engagement of the science community to enhance diversity within the Earth system science community? This case study reveals replicable processes and constructs to enhance the quality of meaningful collaboration and engagement. In addition, the

  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. 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

  7. Does Disturbance Similarly Facilitate Weed Invasion Within Grass, Forb, and Shrub Plots?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Big sagebrush communities (Artemisia tridentata Nutt.) in the Great Basin have been degraded by the synergistic consequences of chronic disturbance and annual weed invasion (Young and Evans 1978). Repairing ecosystem function is an overarching goal of restoration efforts, but it remains unclear whi...

  8. 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

  9. 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. PMID:25248092

  10. 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

  11. Inducible defences as key adaptations for the successful invasion of Daphnia lumholtzi in North America?

    PubMed

    Engel, Katharina; Tollrian, Ralph

    2009-05-22

    The mechanisms underlying successful biological invasions often remain unclear. In the case of the tropical water flea Daphnia lumholtzi, which invaded North America, it has been suggested that this species possesses a high thermal tolerance, which in the course of global climate change promotes its establishment and rapid spread. However, D. lumholtzi has an additional remarkable feature: it is the only water flea that forms rigid head spines in response to chemicals released in the presence of fishes. These morphologically (phenotypically) plastic traits serve as an inducible defence against these predators. Here, we show in controlled mesocosm experiments that the native North American species Daphnia pulicaria is competitively superior to D. lumholtzi in the absence of predators. However, in the presence of fish predation the invasive species formed its defences and became dominant. This observation of a predator-mediated switch in dominance suggests that the inducible defence against fish predation may represent a key adaptation for the invasion success of D. lumholtzi. PMID:19324783

  12. Artificially accelerating the reversal of desertification: cyanobacterial inoculation facilitates the succession of vegetation communities.

    PubMed

    Lan, Shubin; Zhang, Qingyi; Wu, Li; Liu, Yongding; Zhang, Delu; Hu, Chunxiang

    2014-01-01

    Desertification has been recognized as a global environmental problem, and one region experiencing ongoing desertification is the eastern edge of Qubqi Desert (Inner Mongolia). To investigate the facilitating effects of cyanobacterial inoculation technology on the desertification control along this steppe-desert transition region, artificial cyanobacterial crusts were constructed with two filamentous cyanobacteria 3 and 8 years ago combined with Salix planting. The results showed that no crusts formed after 3 years of fixation only with Salix planting, whereas after cyanobacterial inoculation, the crusts formed quickly and gradually succeed to moss crusts. During that course, topsoil environments were gradually improved, providing the necessary material basis for the regeneration of vascular plants. In this investigation, total 27 species of vascular plants had regenerated in the experimental region, mainly belonging to Asteraceae, Poaceae, Chenopodiaceae and Leguminosae. Using space time substitution, the dominant species along with the application of cyanobacterial inoculation technology succeeded from Agriophyllum squarrosum ultimately to Leymus chinensis. In addition, it was found that the shady side of the dunes is more conducive to crust development and succession of vegetation communities. Conclusively, our results indicate artificial cyanobacterial inoculation technology is an effective and desirable path for desertification control. PMID:24303976

  13. 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

  14. 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

  15. 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

  16. 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...

  17. 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

  18. 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

  19. Stromal fibroblasts facilitate cancer cell invasion by a novel invadopodia-independent matrix degradation process.

    PubMed

    Cao, H; Eppinga, R D; Razidlo, G L; Krueger, E W; Chen, J; Qiang, L; McNiven, M A

    2016-03-01

    Metastatic invasion of tumors into peripheral tissues is known to rely upon protease-mediated degradation of the surrounding stroma. This remodeling process uses complex, actin-based, specializations of the plasma membrane termed invadopodia that act both to sequester and release matrix metalloproteinases. Here we report that cells of mesenchymal origin, including tumor-associated fibroblasts, degrade substantial amounts of surrounding matrix by a mechanism independent of conventional invadopodia. These degradative sites lack the punctate shape of conventional invadopodia to spread along the cell base and are reticular and/or fibrous in character. In marked contrast to invadopodia, this degradation does not require the action of Src kinase, Cdc42 or Dyn2. Rather, inhibition of Dyn2 causes a marked upregulation of stromal matrix degradation. Further, expression and activity of matrix metalloproteinases are differentially regulated between tumor cells and stromal fibroblasts. This matrix remodeling by fibroblasts increases the invasive capacity of tumor cells, thereby illustrating how the tumor microenvironment can contribute to metastasis. These findings provide evidence for a novel matrix remodeling process conducted by stromal fibroblasts that is substantially more effective than conventional invadopodia, distinct in structural organization and regulated by disparate molecular mechanisms. PMID:25982272

  20. Cell-surface GRP78 facilitates colorectal cancer cell migration and invasion.

    PubMed

    Li, Zongwei; Zhang, Lichao; Zhao, Yarui; Li, Hanqing; Xiao, Hong; Fu, Rong; Zhao, Chao; Wu, Haili; Li, Zhuoyu

    2013-05-01

    Glucose regulated protein 78 (GRP78) is predominantly located in the endoplasmic reticulum as a molecular chaperone. It has also been found on the membranes of some cancer cells, acting as a receptor for a wide variety of ligands. However, its presence on colorectal cancer (CRC) cell surface and its role in CRC metastatic progression remain elusive. Here we reported that GRP78 was predominantly present in the form of clustering aggregates on CRC cell surfaces, and its surface abundance was strongly correlated with CRC differentiation stage. Interestingly, we observed that cell-surface GRP78 had an interaction with the ECM adhesion molecule β1-integrin and was involved in cell-matrix adhesion through regulation of focal adhesion kinase (FAK). Moreover, the present data also implicated that surface GRP78 promoted the cell invasion process, and this effect was at least partly mediated through its association with uPA-uPAR protease system. Together, our data suggests that surface GRP78 promotes CRC cell migration and invasion by regulating cell-matrix adhesion and ECM degradation, which is independent of its signaling receptor function. PMID:23485528

  1. 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

  2. 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. PMID:23874565

  3. Relationship between invasion success and colony breeding structure in a subterranean termite.

    PubMed

    Perdereau, E; Bagnères, A-G; Vargo, E L; Baudouin, G; Xu, Y; Labadie, P; Dupont, S; Dedeine, F

    2015-05-01

    Factors promoting the establishment and colonization success of introduced populations in new environments constitute an important issue in biological invasions. In this context, the respective role of pre-adaptation and evolutionary changes during the invasion process is a key question that requires particular attention. This study compared the colony breeding structure (i.e. number and relatedness among reproductives within colonies) in native and introduced populations of the subterranean pest termite, Reticulitermes flavipes. We generated and analysed a data set of both microsatellite and mtDNA loci on termite samples collected in three introduced populations, one in France and two in Chile, and in the putative source population of French and Chilean infestations that has recently been identified in New Orleans, LA. We also provided a synthesis combining our results with those of previous studies to obtain a global picture of the variation in breeding structure in this species. Whereas most native US populations are mainly composed of colonies headed by monogamous pairs of primary reproductives, all introduced populations exhibit a particular colony breeding structure that is characterized by hundreds of inbreeding reproductives (neotenics) and by a propensity of colonies to fuse, a pattern shared uniquely with the population of New Orleans. These characteristics are comparable to those of many invasive ants and are discussed to play an important role during the invasion process. Our finding that the New Orleans population exhibits the same breeding structure as its related introduced populations suggests that this native population is pre-adapted to invade new ranges. PMID:25641360

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

    PubMed Central

    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

  5. 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

  6. 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

  7. 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…

  8. IbeR facilitates stress-resistance, invasion and pathogenicity of avian pathogenic Escherichia coli.

    PubMed

    Wang, Shaohui; Bao, Yinli; Meng, Qingmei; Xia, Yongjie; Zhao, Yichao; Wang, Yang; Tang, Fang; ZhuGe, Xiangkai; Yu, Shengqing; Han, Xiangan; Dai, Jianjun; Lu, Chengping

    2015-01-01

    Systemic infections by avian pathogenic Escherichia coli (APEC) are economically devastating to poultry industries worldwide. IbeR, located on genomic island GimA, was shown to serve as an RpoS-like regulator in rpoS gene mutation neonatal meningitis E. coli (NMEC) RS218. However, the role of IbeR in pathogenicity of APEC carrying active RpoS has not yet been investigated. We showed that the APEC IbeR could elicit antibodies in infected ducks, suggesting that IbeR might be involved in APEC pathogenicity. To investigate the function of IbeR in APEC pathogenesis, mutant and complementation strains were constructed and characterized. Inactivation of ibeR led to attenuated virulence and reduced invasion capacity towards DF-1 cells, brains and cerebrospinal fluid (CSF) in vitro and in vivo. Bactericidal assays demonstrated that the mutant strain had impaired resistance to environmental stress and specific pathogen-free (SPF) chicken serum. These virulence-related phenotypes were restored by genetic complementation. Quantitative real-time reverse transcription PCR revealed that IbeR controlled expression of stress-resistance genes and virulence genes, which might led to the associated virulence phenotype. PMID:25768126

  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. Non-invasive, neuron-specific gene therapy can be facilitated by focused ultrasound and recombinant adeno-associated virus

    PubMed Central

    Wang, Shutao; Olumolade, Oluyemi O.; Sun, Tao; Samiotaki, Gesthimani; Konofagou, Elisa E.

    2015-01-01

    Recombinant adeno-associated virus (rAAV) has shown great promise as a potential cure for neurodegenerative diseases. The existence of the blood-brain barrier (BBB), however, hinders efficient delivery of the viral vectors. Direct infusion through craniotomy is the most commonly used approach to achieve rAAV delivery, which carries increased risks of infection and other complications. Here we report a focused ultrasound (FUS) facilitated, non-invasive rAAV delivery paradigm that is capable of producing targeted and neuron-specific transductions. Oscillating ultrasound contrast agents (i.e. microbubbles), driven by focused ultrasound waves, temporarily “unlocking” the BBB, allowing the systemically administrated rAAVs to enter the brain parenchyma, while maintaining their bioactivity and selectivity. Taking the advantage of the neuron-specific promoter-synapsin, rAAV gene expression was triggered almost exclusively (95%) in neurons of the targeted (i.e. caudate-putamen) region. Both behavioral assessment and histological examination revealed no significant long term adverse effects (in the brain and several other critical organs) for this combined treatment paradigm. Results from this study demonstrated the feasibility and safety for the non-invasive, targeted rAAV delivery technique, which might have provided a new arena for gene therapy in both pre-clinical and clinical settings. PMID:25354683

  11. 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

  12. Multitrophic interaction facilitates parasite-host relationship between an invasive beetle and the honey bee.

    PubMed

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

    2007-05-15

    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

  13. Microfabricated collagen tracks facilitate single cell metastatic invasion in 3D.

    PubMed

    Kraning-Rush, Casey M; Carey, Shawn P; Lampi, Marsha C; Reinhart-King, Cynthia A

    2013-03-01

    While the mechanisms employed by metastatic cancer cells to migrate remain poorly understood, it has been widely accepted that metastatic cancer cells can invade the tumor stroma by degrading the extracellular matrix (ECM) with matrix metalloproteinases (MMPs). Although MMP inhibitors showed early promise in preventing metastasis in animal models, they have largely failed clinically. Recently, studies have shown that some cancer cells can use proteolysis to mechanically rearrange their ECM to form tube-like "microtracks" which other cells can follow without using MMPs themselves. We speculate that this mode of migration in the secondary cells may be one example of migration which can occur without endogenous protease activity in the secondary cells. Here we present a technique to study this migration in a 3D, collagen-based environment which mimics the size and topography of the tracks produced by proteolytically active cancer cells. Using time-lapse phase-contrast microscopy, we find that these microtracks permit the rapid and persistent migration of noninvasive MCF10A mammary epithelial cells, which are unable to otherwise migrate in 3D collagen. Additionally, while highly metastatic MDAMB231 breast cancer cells are able to invade a 3D collagen matrix, seeding within the patterned microtracks induced significantly increased cell migration speed, which was not decreased by pharmacological MMP inhibition. Together, these data suggest that microtracks within a 3D ECM may facilitate the migration of cells in an MMP-independent fashion, and may reveal novel insight into the clinical challenges facing MMP inhibitors. PMID:23388698

  14. 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

  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. A Study of Facilitative Leadership Behavior and Its Role in the Success of Schools

    ERIC Educational Resources Information Center

    Toremen, Fatih

    2004-01-01

    In recent years, more progressive approaches regarding the leadership roles of principals have been put forward. Most of those approaches are deeply important as they stress the certain roles of the administration such as cultural leadership and transformative leadership. Supportive of those styles, facilitative leadership puts important…

  17. The Single Parent Family: A Challenge for Children. Successful Parenting. Facilitator's Guide. Part Six.

    ERIC Educational Resources Information Center

    Taylor, Barbara Lynn

    Intended for counselors working in schools or residential child care settings, in child welfare and family preservation services, or in juvenile justice, this facilitator's guide outlines a workshop for children and adolescents growing up in single-parent families. The guide first presents a framework for a one-class or five-class workshop…

  18. 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

  19. 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

  20. 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…

  1. 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.

  2. 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

  3. Facilitation by Pinus flexilis during succession: a hierarchy of mechanisms benefits other plant species.

    PubMed

    Baumeister, Dayna; Callaway, Ragan M

    2006-07-01

    Studies of facilitation have primarily been limited to single mechanisms, species, or environments. We examined interacting mechanisms governing the facilitative effects of Pinus flexilis on two later successional understory species, Pseudotsuga menziesii and Ribes cereum, in different microhabitats and seasons at the ecotone between the Rocky Mountain forests and Great Plains grasslands in Montana, USA. In field surveys, 69% of Pseudotsuga and 91% of Ribes were located beneath P. flexilis even though P. flexilis subcrowns accounted for a small proportion of available habitat. For three years, we monitored the survival of Pseudotsuga and Ribes seedlings experimentally planted beneath P. flexilis and in the open at a windward and a leeward site. Survival of both species was highest beneath P. flexilis at a site topographically protected from strong unidirectional winds (38% for Pseudotsuga and 63% for Ribes), and lowest at a windward site and in the open where tree crowns did not provide shelter from winds (2% and 6%, respectively). These results suggest that wind amelioration contributed to the facilitative effect of P. flexilis. However, even at the leeward site, where wind speed was low, survival of Pseudotsuga and Ribes was higher beneath P. flexilis, suggesting the importance of shade. To explore the relative importance of different mechanisms, we designed an experiment with six treatments: "shade," "shade + wind," "shade + drift," "wind," "drift," and a "control." After two years, we found shade to be of overwhelming importance for the survival of Pseudotsuga and Ribes. Without shade, no other treatments were significant, but once shade was provided, wind amelioration and snow pack accumulation increased survival of Pseudotsuga, suggesting that these different facilitative mechanisms functioned in a nested hierarchical manner: some mechanisms were important only when others were already functioning. Many studies have demonstrated multiple interacting

  4. 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

  5. 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

  6. Patchiness and co-existence of indigenous and invasive mussels at small spatial scales: the interaction of facilitation and competition.

    PubMed

    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

  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. PMID:23573888

  8. Facilitating High Achievement: High School Principals' Reflections on Their Successful Leadership Practices

    ERIC Educational Resources Information Center

    Crum, Karen S.; Sherman, Whitney H.

    2008-01-01

    Purpose: The burden for school improvement in a time of accountability falls squarely on the shoulders of principals as new requirements demand that they act as instructional leaders. The purpose of this study is to discover the common themes of school leadership and instructional practices of high school principals at successful schools in…

  9. Facilitating and Promoting Academic and Social Success for the Adolescent with Attention Deficit Disorder.

    ERIC Educational Resources Information Center

    Spinelli, Cathleen G.

    This paper discusses the role of resource center teachers in helping students with attention deficit disorder (ADD) successfully make the transition to secondary school. It addresses: (1) characteristics of ADD, including academic underachievement, cognitive fatigue, fine motor dysfunction, lack of self-monitoring skills, poorly developed…

  10. Training Career Adaptability to Facilitate a Successful School-to-Work Transition

    ERIC Educational Resources Information Center

    Koen, Jessie; Klehe, Ute-Christine; Van Vianen, Annelies E. M.

    2012-01-01

    The transition from school to work is one of the most critical steps in graduates' careers, as it can determine vocational outcomes and future career success. Yet, these newcomers to the labor market often take longer than regular job seekers to find a suitable job, are more likely to experience a job mismatch and to suffer from underemployment.…

  11. 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…

  12. 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…

  13. How did we make the Interdisciplinary Generalist Curriculum Project work? National efforts to facilitate success.

    PubMed

    Lesky, L; Davis, A; Cooke, M

    2001-04-01

    The Interdisciplinary Generalist Curriculum (IGC) Project created curricular changes at the participating schools with very little direct financial support. A reconsideration of the process of this national effort reveals many intangible elements that were as critical to the project's successes as were the direct dollars. Those factors included careful attention to the criteria for school selection, specific project requirements that allowed institutional flexibility in project evolution, national assistance in program implementation, early and ongoing national recognition for project schools, and a highly organized, involved, and goal-oriented national organization. This national initiative provides a successful model for future funding of projects in this era of dwindling financial support for medical education innovation. PMID:11299167

  14. Using support programs to facilitate academic success in African American students.

    PubMed

    Stokes, L G; Claytor, K

    1998-01-01

    Academic problems resulting from both internal and external factors affect the ability of students to be successful in their course study. Verbalization about problems and concerns to supportive teachers and counselors is not uncommon. However students often do not possess the knowledge and skills needed to handle these problems. This article describes support programs that have been put into place at Indiana University School of Nursing to assist students with specific problems and describes the benefits associated with these programs. PMID:10196865

  15. 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.

  16. Successful long-term management of invasive cerebral fungal infection following liver transplantation.

    PubMed

    Patel, Madhukar S; Wright, Alissa J; Kohn, Rachel; Markmann, James F; Kotton, Camille N; Vagefi, Parsia A

    2015-03-01

    Central nervous system (CNS) infections after liver transplantation may be fungal in aetiology, with involvement from either common organisms such as Cryptococcus neoformans and Aspergillus spp. as well as less common organisms, such as the Mucorales and Scedosporium spp. Although the mortality of CNS fungal infections was nearly 100% in early series, more recent data has suggested that good outcomes can be achieved. This may be due to both improved diagnostic capabilities, such as the ability to obtain fungal susceptibilities and therapeutic drug levels, and improved therapeutic options, such as the newer triazoles- voriconazole and posaconazole. Due to improved outcomes, issues have now arisen around the long-term tolerability of these agents. The following two cases of invasive cerebral fungal infections following liver transplantation, one with Aspergillus flavus, and the other with Scedosporium boydii/apiospermum highlight the success that can be seen with the modern management of a previously fatal diagnosis. In particular, we highlight the issues around therapeutic monitoring and discontinuation of therapy. PMID:25590987

  17. Elevated CO2 increases productivity and invasive species success in an arid ecosystem

    NASA Astrophysics Data System (ADS)

    Smith, Stanley D.; Huxman, Travis E.; Zitzer, Stephen F.; Charlet, Therese N.; Housman, David C.; Coleman, James S.; Fenstermaker, Lynn K.; Seemann, Jeffrey R.; Nowak, Robert S.

    2000-11-01

    Arid ecosystems, which occupy about 20% of the earth's terrestrial surface area, have been predicted to be one of the most responsive ecosystem types to elevated atmospheric CO2 and associated global climate change. Here we show, using free-air CO2 enrichment (FACE) technology in an intact Mojave Desert ecosystem, that new shoot production of a dominant perennial shrub is doubled by a 50% increase in atmospheric CO2 concentration in a high rainfall year. However, elevated CO 2 does not enhance production in a drought year. We also found that above-ground production and seed rain of an invasive annual grass increases more at elevated CO2 than in several species of native annuals. Consequently, elevated CO2 might enhance the long-term success and dominance of exotic annual grasses in the region. This shift in species composition in favour of exotic annual grasses, driven by global change, has the potential to accelerate the fire cycle, reduce biodiversity and alter ecosystem function in the deserts of western North America.

  18. 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

  19. 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.

  20. Eradication success down under: heat treatment of a sunken trawler to kill the invasive seaweed Undaria pinnatifida.

    PubMed

    Wotton, Debra M; O'Brien, Chris; Stuart, Mike D; Fergus, Dougal J

    2004-11-01

    Eradication of invasive species is difficult in the marine environment, and there have only been a few successes. We report the successful eradication of the invasive seaweed Undaria pinnatifida from a sunken trawler in the Chatham Islands, New Zealand. New heat-treatment methods were developed as the most cost effective and environmentally acceptable option to kill Undaria. Monitoring of the trawler for three years after it sank found no Undaria after the vessel was treated. Key factors in the success of the eradication programme included: early detection, a rapid response, pre-existing knowledge of Undaria, an adaptive management approach, targeting of multiple life history stages, and the cooperation of the vessel's insurer. PMID:15530528

  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. The integrin alphav beta3 increases cellular stiffness and cytoskeletal remodeling dynamics to facilitate cancer cell invasion

    NASA Astrophysics Data System (ADS)

    Mierke, Claudia Tanja

    2013-01-01

    The process of cancer cell invasion through the extracellular matrix (ECM) of connective tissue plays a prominent role in tumor progression and is based fundamentally on biomechanics. Cancer cell invasion usually requires cell adhesion to the ECM through the cell-matrix adhesion receptors integrins. The expression of the αvβ3 integrin is increased in several tumor types and is consistently associated with increased metastasis formation in patients. The hypothesis was that the αvβ3 integrin expression increases the invasiveness of cancer cells through increased cellular stiffness, and increased cytoskeletal remodeling dynamics. Here, the invasion of cancer cells with different αvβ3 integrin expression levels into dense three-dimensional (3D) ECMs has been studied. Using a cell sorter, two subcell lines expressing either high or low amounts of αvβ3 integrins (αvβ3high or αvβ3low cells, respectively) have been isolated from parental MDA-MB-231 breast cancer cells. αvβ3high cells showed a threefold increased cell invasion compared to αvβ3low cells. Similar results were obtained for A375 melanoma, 786-O kidney and T24 bladder carcinoma cells, and cells in which the β3 integrin subunit was knocked down using specific siRNA. To investigate whether contractile forces are essential for αvβ3 integrin-mediated increased cellular stiffness and subsequently enhanced cancer cell invasion, invasion assays were performed in the presence of myosin light chain kinase inhibitor ML-7 and Rho kinase inhibitor Y27632. Indeed, cancer cell invasiveness was reduced after addition of ML-7 and Y27632 in αvβ3high cells but not in αvβ3low cells. Moreover, after addition of the contractility enhancer calyculin A, an increase in pre-stress in αvβ3low cells was observed, which enhanced cellular invasiveness. In addition, inhibition of the Src kinase, STAT3 or Rac1 strongly reduced the invasiveness of αvβ3high cells, whereas the invasiveness of β3 specific knock

  3. "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,…

  4. 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. PMID:23936301

  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. 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...

  7. 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.

  8. Induction of Brain Microvascular Endothelial Cell Urokinase Expression by Cryptococcus neoformans Facilitates Blood-Brain Barrier Invasion

    PubMed Central

    Stie, Jamal; Fox, Deborah

    2012-01-01

    The invasive ability of the blood-borne fungal pathogen Cryptococcus neoformans can be enhanced through interactions with host plasma components, such as plasminogen. Previously we showed by in vitro studies that plasminogen coats the surface of C. neoformans and is converted to the active serine protease, plasmin, by host plasminogen activators. Viable, but not formaldehyde- or sodium azide-killed, cryptococcal strains undergo brain microvascular endothelial cell-dependent plasminogen-to-plasmin activation, which results in enhanced, plasmin-dependent cryptococcal invasion of primary bovine brain microvascular endothelial cells and fungal ability to degrade plasmin substrates. In the present work, brain microvascular endothelial cells cultured with viable, but not killed, cryptococcal strains led to significant increases in both urokinase mRNA transcription and cell-associated urokinase protein expression. Soluble urokinase was also detected in conditioned medium from brain microvascular endothelial cells cultured with viable, but not killed, C. neoformans. Exposure of plasminogen pre-coated viable C. neoformans to conditioned medium from strain-matched brain microvascular endothelial cell-fungal co-cultures resulted in plasminogen-to-plasmin activation and plasmin-dependent cryptococcal invasion. siRNA-mediated silencing of urokinase gene expression or the use of specific inhibitors of urokinase activity abrogated both plasminogen-to-plasmin activation on C. neoformans and cryptococcal-brain microvascular endothelial cell invasion. Our results suggest that pathogen exploitation of the host urokinase-plasmin(ogen) system may contribute to C. neoformans virulence during invasive cryptococcosis. PMID:23145170

  9. '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

  10. 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.

  11. 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

  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. Successful Treatment of Tracheal Invasion Caused by Thyroid Cancer Using Endotracheal Tube Balloon Inflation under Flexible Bronchoscopic Guidance.

    PubMed

    Han, Yang-Hee; Jung, Bock-Hyun; Kwon, Jun Sung; Lim, Jaemin

    2014-11-01

    Tracheal invasion is an uncommon complication of thyroid cancer, but it can cause respiratory failure. A rigid bronchoscope may be used to help relieve airway obstruction, but general anesthesia is usually required. Tracheal balloon dilatation and stent insertion can be performed without general anesthesia, but complete airway obstruction during balloon inflation may be dangerous in some patients. Additionally, placement of the stent adjacent to the vocal cords can be technically challenging. An 86-year-old female patient with tracheal invasion resulting from thyroid cancer was admitted to our hospital because of worsening dyspnea. Due to the patient's refusal of general anesthesia and the interventional radiologist's difficulty in completing endotracheal stenting, we performed endotracheal tube balloon dilatation and argon plasma coagulation. We have successfully treated tracheal obstruction in the patient with thyroid cancer by using endotracheal tube balloon inflation and a flexible bronchoscope without general anesthesia or airway obstruction during balloon inflation. PMID:25473409

  14. 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

  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. Successive Invasion-Mediated Interspecific Hybridizations and Population Structure in the Endangered Cichlid Oreochromis mossambicus

    PubMed Central

    Firmat, Cyril; Alibert, Paul; Losseau, Michèle; Baroiller, Jean-François; Schliewen, Ulrich K.

    2013-01-01

    Hybridization between invasive and native species accounts among the major and pernicious threats to biodiversity. The Mozambique tilapia Oreochromis mossambicus, a widely used freshwater aquaculture species, is especially imperiled by this phenomenon since it is recognized by the IUCN as an endangered taxon due to genetic admixture with O. niloticus an invasive congeneric species. The Lower Limpopo and the intermittent Changane River (Mozambique) drain large wetlands of potentially great importance for conservation of O. mossambicus, but their populations have remained unstudied until today. Therefore we aimed (1) to estimate the autochthonous diversity and population structure among genetically pure O. mossambicus populations to provide a baseline for the conservation genetics of this endangered species, (2) to quantify and describe genetic variation of the invasive populations and investigate the most likely factors influencing their spread, (3) to identify O. mossambicus populations unaffected by hybridization. Bayesian assignment tests based on 423 AFLP loci and the distribution of 36 species-specific mitochondrial haplotypes both indicate a low frequency of invasive and hybrid genotypes throughout the system, but nevertheless reveal evidence for limited expansion of two alien species (O. niloticus and O. andersonii) and their hybrids in the Lower Limpopo. O. mossambicus populations with no traces of hybridization are identified. They exhibit a significant genetic structure. This contrasts with previously published estimates and provides rather promising auspices for the conservation of O. mossambicus. Especially, parts of the Upper Changane drainage and surrounding wetlands are identified as refugial zones for O. mossambicus populations. They should therefore receive high conservation priority and could represent valuable candidates for the development of aquaculture strains based on local genetic resources. PMID:23671704

  18. 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. ...

  19. 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

  20. 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...

  1. Chronic Invasive Aspergillus Sinusitis and Otitis with Meningeal Extension Successfully Treated with Voriconazole

    PubMed Central

    Morgand, Marjolaine; Rammaert, Blandine; Poirée, Sylvain; Bougnoux, Marie-Elisabeth; Tran, Hugo; Kania, Romain; Chrétien, Fabrice; Jouvion, Gregory

    2015-01-01

    Invasive aspergillosis (IA) is a severe disseminated fungal disease that occurs mostly in immunocompromised patients. However, central nervous system IA, combining meningitis and skull base involvement, does not occur only in groups with classic risk factors for IA; patients with chronic renal failure and diabetes mellitus are also at risk for more chronic forms. In both of our proven IA cases, voriconazole monotherapy was effective without surgery, and cerebrospinal fluid and serum 1,3-β-d-glucan test results were initially positive, in contrast to galactomannan antigen results. PMID:26392507

  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. PMID:26582547

  3. Selection of the antifungal agent decides prognosis of invasive aspergillosis: case report of a successful outcome with voriconazole.

    PubMed

    Arakawa, Hisaya; Suto, Chikako; Notani, Hiroko; Ishida, Takashi; Abe, Kayoko; Ookubo, Yasuo

    2014-02-01

    Invasive aspergillosis is a rare disease and is often misdiagnosed. The clinical course is quite aggressive and it is a potentially fatal disease. We report a case of invasive aspergillosis involving the dura mater and optic nerves which was successfully treated with voriconazole, even though the patient had residual monocular blindness. An 86-year-old Japanese man complained of developing loss of vision in his left eye while taking oral fluconazole prescribed by an otolaryngologist for mycosis of the left maxillary sinus. He was referred to our hospital. At the first visit, he already had no light perception in the left eye, with decreased ocular motility in all directions and orbital apex syndrome. His corrected distance visual acuity (CDVA) in the right eye was 20/25 with enlargement of Mariotte's blind spot. Magnetic resonance imaging revealed inflammation around both optic nerves that also involved the dura mater. His antifungal therapy was changed to intravenous voriconazole. Although his right CDVA temporarily declined to 20/50, it improved to 20/16 by 10 months after the initiation of treatment. Maxillary sinus biopsy detected Aspergillus. Invasive aspergillosis progresses rapidly and aggressively. The present case highlights the importance of early diagnosis and selection of an appropriate antifungal agent. PMID:23397120

  4. A native fungal symbiont facilitates the prevalence and development of an invasive pathogen-native vector symbiosis.

    PubMed

    Zhao, Lilin; Lu, Min; Niu, Hongtao; Fang, Guofei; Zhang, Shuai; Sun, Jianghua

    2013-12-01

    Invasive pathogen-insect symbioses have been extensively studied in many different ecological niches. Whether the damage of symbioses in different introduced regions might be influenced by other microorganisms has, however, received little attention. Eight years of field data showed that the varied levels of the nematode and beetle populations and infested trees of the invasive Bursaphelenchus xylophilus--Monochamus alternatus symbiosis were correlated with patterns in the isolation frequencies of ophiostomatoid fungi at six sites, while the laboratory experiments showed that the nematode produced greater numbers of offspring with a female-biased sex ratio and developed faster in the presence of one native symbiotic ophiostomatoid fungus, Sporothrix sp. 1. Diacetone alcohol (DAA) from xylem inoculated with Sporothrix sp. 1 induced B. xylophilus to produce greater numbers of offspring. Its presence also significantly increased the growth and survival rate of M. alternatus, and possibly explains the prevalence of the nematode-vector symbiosis when Sporothrix sp. 1 was dominant in the fungal communities. Studying the means by which multispecies interactions contributed to biogeographical dynamics allowed us to better understand the varied levels of damage caused by biological invasion across the invaded range. PMID:24597227

  5. 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

  6. Overexpression of CD44 in Neural Precursor Cells Improves Trans- Endothelial Migration and Facilitates Their Invasion of Perivascular Tissues In Vivo

    PubMed Central

    Deboux, Cyrille; Ladraa, Sophia; Cazaubon, Sylvie; Ghribi-Mallah, Siham; Weiss, Nicolas; Chaverot, Nathalie; Couraud, Pierre Olivier; Evercooren, Anne Baron-Van

    2013-01-01

    Neural precursor (NPC) based therapies are used to restore neurons or oligodendrocytes and/or provide neuroprotection in a large variety of neurological diseases. In multiple sclerosis models, intravenously (i.v) -delivered NPCs reduced clinical signs via immunomodulation. We demonstrated recently that NPCs were able to cross cerebral endothelial cells in vitro and that the multifunctional signalling molecule, CD44 involved in trans-endothelial migration of lymphocytes to sites of inflammation, plays a crucial role in extravasation of syngeneic NPCs. In view of the role of CD44 in NPCs trans-endothelial migration in vitro, we questioned presently the benefit of CD44 overexpression by NPCs in vitro and in vivo, in EAE mice. We show that overexpression of CD44 by NPCs enhanced over 2 folds their trans-endothelial migration in vitro, without impinging on the proliferation or differentiation potential of the transduced cells. Moreover, CD44 overexpression by NPCs improved significantly their elongation, spreading and number of filopodia over the extracellular matrix protein laminin in vitro. We then tested the effect of CD44 overexpression after i.v. delivery in the tail vein of EAE mice. CD44 overexpression was functional in vivo as it accelerated trans-endothelial migration and facilitated invasion of HA expressing perivascular sites. These in vitro and in vivo data suggest that CD44 may be crucial not only for NPC crossing the endothelial layer but also for facilitating invasion of extravascular tissues. PMID:23468987

  7. 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

  8. 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.

  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. 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

  11. 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

  12. Buschke-Löwenstein Tumour: Successful Treatment with Minimally Invasive Techniques.

    PubMed

    Correia, Estefânia; Santos, António

    2015-01-01

    We report a case of an 80-year-old female who presented with a four-year history of a growing mass in the perianal area with pain and bleeding during defaecation. Clinical examination revealed a locally destructive, cauliflower-like, verrucous mass measuring 10 × 12 cm in diameter. Histologic findings revealed a moderate degree of dysplasia of the epithelium with koilocytosis atypia, acanthosis, and parakeratosis, features that are consistent with Buschke-Löwenstein tumour. Polymerase-chain-reaction assay for human papillomavirus (HPV) showed an infection with HPV type 11. Full-thickness excision of involved skin was undertaken by cryotherapy and electrocautery over five months. The entire wound was left open to heal by secondary intention. After 3 years of follow-up, the patient has not experienced a recurrence, with excellent functional results, but the cosmetic results were satisfactory. These minimally invasive techniques can be safer and more cost-effective than surgery and the General Practitioner can play a key role in diagnosis. PMID:26417462

  13. Buschke-Löwenstein Tumour: Successful Treatment with Minimally Invasive Techniques

    PubMed Central

    Correia, Estefânia; Santos, António

    2015-01-01

    We report a case of an 80-year-old female who presented with a four-year history of a growing mass in the perianal area with pain and bleeding during defaecation. Clinical examination revealed a locally destructive, cauliflower-like, verrucous mass measuring 10 × 12 cm in diameter. Histologic findings revealed a moderate degree of dysplasia of the epithelium with koilocytosis atypia, acanthosis, and parakeratosis, features that are consistent with Buschke-Löwenstein tumour. Polymerase-chain-reaction assay for human papillomavirus (HPV) showed an infection with HPV type 11. Full-thickness excision of involved skin was undertaken by cryotherapy and electrocautery over five months. The entire wound was left open to heal by secondary intention. After 3 years of follow-up, the patient has not experienced a recurrence, with excellent functional results, but the cosmetic results were satisfactory. These minimally invasive techniques can be safer and more cost-effective than surgery and the General Practitioner can play a key role in diagnosis. PMID:26417462

  14. 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. PMID:23227254

  15. Experienced radio-guided surgery teams can successfully perform minimally invasive radio-guided parathyroidectomy without intraoperative parathyroid hormone assays.

    PubMed

    Caudle, Abigail S; Brier, Sarah E; Calvo, Benjamin F; Kim, Hong Jin; Meyers, Michael O; Ollila, David W

    2006-09-01

    Minimally invasive parathyroidectomy is an accepted treatment option for primary hyperparathyroidism. The need for intraoperative parathyroid hormone assays (iPTH) to confirm adenoma removal remains controversial. We studied minimally invasive radio-guided parathyroidectomy (MIRP) performed using preoperative sestamibi localization studies, intraoperative gamma detection probe, and the selective use of frozen section pathology without the use of iPTH. This is a single institution review of patients with primary hyperparathyroidism treated with MIRP by surgeons experienced in radio-guided surgery between October 1, 1998 and July 15, 2005. Information was obtained by reviewing computer medical records as well as contacting primary care physicians. Factors evaluated included laboratory values, pathology results, and evidence of recurrence. One hundred forty patients were included with a median preoperative calcium level of 11.3 mg/dL (range, 9.6-17) and a PTH level of 147 pg/mL (range, 19-5042). The median postoperative calcium level was 9.3 mg/dL. All patients were initially eucalcemic postoperatively except for one who had normal parathyroid levels. However, five (4%) patients required re-exploration for various reasons. Of the failures, one was secondary to the development of secondary hyperparathyroidism, and therefore would not have benefited from iPTH, one had thyroid tissue removed at the first operation, and three developed evidence of a second adenoma. One of these three patients had a drop in PTH level from 1558 pg/mL preoperatively to 64 pg/mL on postoperative Day 1, indicating that iPTH would not have prevented this failure. Thus, only three (2.1%) patients could have potentially benefited from the use of iPTH. MIRP was successful in 96 per cent of patients using a combination of preoperative sestamibi scans, intraoperative localization with a gamma probe, and the selective use of frozen pathology. This correlates with reported success rates of 95 per cent

  16. Invasive Pulmonary Aspergillosis in a Haematopoietic Stem Cell Transplant Recipient with Sickle Cell Disease: a Successful Treatment

    PubMed Central

    Paciaroni, Katia; De Angelis, Gioia; Gallucci, Cristiano; Alfieri, Cecilia; Ribersani, Michela; Roveda, Andrea; Isgrò, Antonella; Marziali, Marco; Aloi, Ivan Pietro; Inserra, Alessandro; Gaziev, Javid; Sodani, Pietro; Lucarelli, Guido

    2015-01-01

    Sickle Cell Anaemia (SCA) is the most common inherited blood disorder and is associated with severe morbidity and decreased survival. Allogeneic Haematopoietic Stem Cell Transplantation (HSCT) is the only curative approach. Nevertheless the decision to perform a bone marrow transplant includes the risk of major complications and transplant-related mortality. Infections represent the leading cause of death in SCA patients undergoing HSCT. Invasive Pulmonary Aspergillosis (IPA) is a devastating opportunistic infection and remains a significant cause of morbidity and mortality in HSCT recipients. Data regarding IPA in the setting of SCA are lacking. In the present report, we describe a patient with SCA, who developed IPA after allogeneic bone marrow transplant. The fungal infection was treated by systemic antifungal therapy in addition to surgery, despite mild chronic graft versus host disease (GVHD) and continuing immunosuppressive therapy. This case shows that IPA occurring in bone marrow recipients with SCA can be successfully treated. PMID:25574365

  17. Invasive pulmonary aspergillosis in a haematopoietic stem cell transplant recipient with sickle cell disease: a successful treatment.

    PubMed

    Paciaroni, Katia; De Angelis, Gioia; Gallucci, Cristiano; Alfieri, Cecilia; Ribersani, Michela; Roveda, Andrea; Isgrò, Antonella; Marziali, Marco; Aloi, Ivan Pietro; Inserra, Alessandro; Gaziev, Javid; Sodani, Pietro; Lucarelli, Guido

    2015-01-01

    Sickle Cell Anaemia (SCA) is the most common inherited blood disorder and is associated with severe morbidity and decreased survival. Allogeneic Haematopoietic Stem Cell Transplantation (HSCT) is the only curative approach. Nevertheless the decision to perform a bone marrow transplant includes the risk of major complications and transplant-related mortality. Infections represent the leading cause of death in SCA patients undergoing HSCT. Invasive Pulmonary Aspergillosis (IPA) is a devastating opportunistic infection and remains a significant cause of morbidity and mortality in HSCT recipients. Data regarding IPA in the setting of SCA are lacking. In the present report, we describe a patient with SCA, who developed IPA after allogeneic bone marrow transplant. The fungal infection was treated by systemic antifungal therapy in addition to surgery, despite mild chronic graft versus host disease (GVHD) and continuing immunosuppressive therapy. This case shows that IPA occurring in bone marrow recipients with SCA can be successfully treated. PMID:25574365

  18. 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

  19. 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.

  20. Cholangiocyte Myosin IIB Is Required for Localized Aggregation of Sodium Glucose Cotransporter 1 to Sites of Cryptosporidium parvum Cellular Invasion and Facilitates Parasite Internalization ▿

    PubMed Central

    O'Hara, Steven P.; Gajdos, Gabriella B.; Trussoni, Christy E.; Splinter, Patrick L.; LaRusso, Nicholas F.

    2010-01-01

    Internalization of the obligate intracellular apicomplexan parasite, Cryptosporidium parvum, results in the formation of a unique intramembranous yet extracytoplasmic niche on the apical surfaces of host epithelial cells, a process that depends on host cell membrane extension. We previously demonstrated that efficient C. parvum invasion of biliary epithelial cells (cholangiocytes) requires host cell actin polymerization and localized membrane translocation/insertion of Na+/glucose cotransporter 1 (SGLT1) and of aquaporin 1 (Aqp1), a water channel, at the attachment site. The resultant localized water influx facilitates parasite cellular invasion by promoting host-cell membrane protrusion. However, the molecular mechanisms by which C. parvum induces membrane translocation/insertion of SGLT1/Aqp1 are obscure. We report here that cultured human cholangiocytes express several nonmuscle myosins, including myosins IIA and IIB. Moreover, C. parvum infection of cultured cholangiocytes results in the localized selective aggregation of myosin IIB but not myosin IIA at the region of parasite attachment, as assessed by dual-label immunofluorescence confocal microscopy. Concordantly, treatment of cells with the myosin light chain kinase inhibitor ML-7 or the myosin II-specific inhibitor blebbistatin or selective RNA-mediated repression of myosin IIB significantly inhibits (P < 0.05) C. parvum cellular invasion (by 60 to 80%). Furthermore ML-7 and blebbistatin significantly decrease (P < 0.02) C. parvum-induced accumulation of SGLT1 at infection sites (by approximately 80%). Thus, localized actomyosin-dependent membrane translocation of transporters/channels initiated by C. parvum is essential for membrane extension and parasite internalization, a phenomenon that may also be relevant to the mechanisms of cell membrane protrusion in general. PMID:20457792

  1. DSG3 Facilitates Cancer Cell Growth and Invasion through the DSG3-Plakoglobin-TCF/LEF-Myc/Cyclin D1/MMP Signaling Pathway

    PubMed Central

    Chen, Yin-Ju; Lee, Li-Yu; Chao, Yin-Ka; Chang, Joseph T.; Lu, Ya-Ching; Li, Hsiao-Fang; Chiu, Ching-Chi; Li, Yi-Chen; Li, Yan-Liang; Chiou, Jeng-Fong; Cheng, Ann-Joy

    2013-01-01

    Desmoglein 3 (DSG3) is a component of the desmosome, which confers strong cell-cell adhesion. Previously, an oncogenic function of DSG3 has been found in head neck cancer (HNC). Here, we investigated how this molecule contributes to the malignant phenotype. Because DSG3 is associated with plakoglobin, we examined whether these phenotypic alterations were mediated through the plakoglobin molecule. Immunoprecipitation and immunofluorescence staining revealed that DSG3 silencing disrupted its interaction with plakoglobin and induced plakoglobin translocation from the cytoplasm to the nucleus. Knockdown of DSG3 significantly increased the interaction of plakoglobin with the transcriptional factor TCF and suppressed the TCF/LEF transcriptional activity. These effects further conferred to reduced expression of the TCF/LEF downstream target genes, including c-myc, cyclin D1, and MMP-7. Functional analyses showed that DSG3 silencing reduced cell growth and arrested cells at G0/G1 phase. Besides, cell migration and invasion abilities were also decreased. These cellular results were confirmed using tumor xenografts in mice, as DSG3 silencing led to the suppressed tumor growth, plakoglobin translocation and reduced expression of TCF/LEF target genes in tumors. Therefore, our study shows that the desmosomal protein DSG3 additionally functions to regulate malignant phenotypes via nuclear signaling. In conclusion, we found that DSG3 functions as an oncogene and facilitates cancer growth and invasion in HNC cells through the DSG3-plakoglobin-TCF/LEF pathway. PMID:23737966

  2. Intracellular Parasite Invasion Strategies

    NASA Astrophysics Data System (ADS)

    Sibley, L. D.

    2004-04-01

    Intracellular parasites use various strategies to invade cells and to subvert cellular signaling pathways and, thus, to gain a foothold against host defenses. Efficient cell entry, ability to exploit intracellular niches, and persistence make these parasites treacherous pathogens. Most intracellular parasites gain entry via host-mediated processes, but apicomplexans use a system of adhesion-based motility called ``gliding'' to actively penetrate host cells. Actin polymerization-dependent motility facilitates parasite migration across cellular barriers, enables dissemination within tissues, and powers invasion of host cells. Efficient invasion has brought widespread success to this group, which includes Toxoplasma, Plasmodium, and Cryptosporidium.

  3. Invasion success and development of benthic assemblages: effect of timing, duration of submersion and substrate type.

    PubMed

    Vaz-Pinto, F; Torrontegi, O; Prestes, A C L; Alvaro, N V; Neto, A I; Martins, G M

    2014-03-01

    Several studies have suggested that communities associated with artificial substrata support more non-indigenous species (NIS) than natural habitats, and may function as corridors for their expansion. Our study focused on the role of substrate type, timing and duration of submersion as determinants of fouling assemblage. We used plates made of basalt, concrete or fibreglass, to assess early, i.e., 3 months, and late, i.e., 12 months, succession in benthic communities. To assess spatial and temporal variability of the results, sampling was performed at 2 locations and the experiment was repeated in two seasons of the year. Our results showed that the timing and duration of submersion affected the number and percent cover of natives and NIS, as well as assemblage composition. Moreover, the present study showed no support for the hypothesis that marine NIS are more abundant on artificial substrata, as neither of the two artificial substrata tested supported a greater number of NIS compared to basalt (the natural substratum). Overall, fibreglass presented the most different benthic assemblage composition, supporting the fact that the extent and nature of the observed differences varied not only between natural and artificial substrata, but also according to the type of artificial habitat considered. Thus, our results are in agreement with previous studies that stated that appropriate strategies for environmental management should integrate ecological assessment in order to maintain natural patterns of distribution and abundance of organisms, scales of variability and relevant ecological processes. PMID:24374052

  4. 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.…

  5. 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…

  6. 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

  7. Does Temperature-Mediated Reproductive Success Drive the Direction of Species Displacement in Two Invasive Species of Leafminer Fly?

    PubMed Central

    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

  8. 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

  9. 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

  10. Morphine does not facilitate breast cancer progression in two preclinical mouse models for human invasive lobular and HER2⁺ breast cancer.

    PubMed

    Doornebal, Chris W; Vrijland, Kim; Hau, Cheei-Sing; Coffelt, Seth B; Ciampricotti, Metamia; Jonkers, Jos; de Visser, Karin E; Hollmann, Markus W

    2015-08-01

    Morphine and other opioid analgesics are potent pain-relieving agents routinely used for pain management in patients with cancer. However, these drugs have recently been associated with a worse relapse-free survival in patients with surgical cancer, thus suggesting that morphine adversely affects cancer progression and relapse. In this study, we evaluated the impact of morphine on breast cancer progression, metastatic dissemination, and outgrowth of minimal residual disease. Using preclinical mouse models for metastatic invasive lobular and HER2 breast cancer, we show that analgesic doses of morphine do not affect mammary tumor growth, angiogenesis, and the composition of tumor-infiltrating immune cells. Our studies further demonstrate that morphine, administered in the presence or absence of surgery-induced tissue damage, neither facilitates de novo metastatic dissemination nor promotes outgrowth of minimal residual disease after surgery. Together, these findings indicate that opioid analgesics can be used safely for perioperative pain management in patients with cancer and emphasize that current standards of "good clinical practice" should be maintained. PMID:25734987

  11. 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

  12. 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

  13. 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.

  14. 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

  15. Propagule pressure and colony social organization are associated with the successful invasion and rapid range expansion of fire ants in China.

    PubMed

    Yang, Chin-Cheng; Ascunce, Marina S; Luo, Li-Zhi; Shao, Jing-Guo; Shih, Cheng-Jen; Shoemaker, DeWayne

    2012-02-01

    We characterized patterns of genetic variation in populations of the fire ant Solenopsis invicta in China using mitochondrial DNA sequences and nuclear microsatellite loci to test predictions as to how propagule pressure and subsequent dispersal following establishment jointly shape the invasion success of this ant in this recently invaded area. Fire ants in Wuchuan (Guangdong Province) are genetically differentiated from those found in other large infested areas of China. The immediate source of ants in Wuchuan appears to be somewhere near Texas, which ranks first among the southern USA infested states in the exportation of goods to China. Most colonies from spatially distant, outlying areas in China are genetically similar to one another and appear to share a common source (Wuchuan, Guangdong Province), suggesting that long-distance jump dispersal has been a prevalent means of recent spread of fire ants in China. Furthermore, most colonies at outlier sites are of the polygyne social form (featuring multiple egg-laying queens per nest), reinforcing the important role of this social form in the successful invasion of new areas and subsequent range expansion following invasion. Several analyses consistently revealed characteristic signatures of genetic bottlenecks for S. invicta populations in China. The results of this study highlight the invasive potential of this pest ant, suggest that the magnitude of international trade may serve as a predictor of propagule pressure and indicate that rates and patterns of subsequent range expansion are partly determined by the interplay between species traits and the trade and transportation networks. PMID:22181975

  16. Does Invasion Success Reflect Superior Cognitive Ability? A Case Study of Two Congeneric Lizard Species (Lampropholis, Scincidae)

    PubMed Central

    Shine, Richard

    2014-01-01

    A species' intelligence may reliably predict its invasive potential. If this is true, then we might expect invasive species to be better at learning novel tasks than non-invasive congeners. To test this hypothesis, we exposed two sympatric species of Australian scincid lizards, Lampropholis delicata (invasive) and L. guichenoti (non-invasive) to standardized maze-learning tasks. Both species rapidly decreased the time they needed to find a food reward, but latencies were always higher for L. delicata than L. guichenoti. More detailed analysis showed that neither species actually learned the position of the food reward; they were as likely to turn the wrong way at the end of the study as at the beginning. Instead, their times decreased because they spent less time immobile in later trials; and L. guichenoti arrived at the reward sooner because they exhibited “freezing” (immobility) less than L. delicata. Hence, our data confirm that the species differ in their performance in this standardized test, but neither the decreasing time to find the reward, nor the interspecific disparity in those times, are reflective of cognitive abilities. Behavioural differences may well explain why one species is invasive and one is not, but those differences do not necessarily involve cognitive ability. PMID:24475097

  17. 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

  18. 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

  19. 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

  20. 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

  1. 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

  2. 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

  3. 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

  4. 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

  5. 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-...

  6. Facilitating Success for New Teachers.

    ERIC Educational Resources Information Center

    Weasmer, Jerie; Woods, Amelia Mays

    1998-01-01

    To help beginning teachers succeed, principals should identify individual teachers' strengths and weaknesses during the interviewing/hiring stage, balance neophytes' workloads, limit their extracurricular activities, establish expectations, select veteran mentors, offer informal formative assessment, be specific about classroom observations, and…

  7. Imaging and minimally invasive aortic valve replacement

    PubMed Central

    Loor, Gabriel

    2015-01-01

    Cardiovascular imaging has been the most important tool allowing for innovation in cardiac surgery. There are now a variety of approaches available for treating aortic valve disease, including standard sternotomy, minimally invasive surgery, and percutaneous valve replacement. Minimally invasive cardiac surgery relies on maximizing exposure within a limited field of view. The complexity of this approach is increased as the relationship between the great vessels and the bony thorax varies between individuals. Ultimately, the success of minimally invasive surgery depends on appropriate choices regarding the type and location of the incision, cannulation approach, and cardioprotection strategy. These decisions are facilitated by preoperative imaging, which forms the focus of this review. PMID:25694979

  8. 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.

  9. 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

  10. 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...

  11. 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

  12. Reflections as Near-Peer Facilitators of an Inquiry Project for Undergraduate Anatomy: Successes and Challenges from a Term of Trial-and-Error

    ERIC Educational Resources Information Center

    Anstey, Lauren M.; Michels, Alison; Szymus, Julianna; Law, Wyanne; Ho, Man-Hymn Edwin; Qu, Fei; Yeung, Ralph T. T.; Chow, Natalie

    2014-01-01

    Near-peer facilitators (senior students serving as facilitators to their more junior peers) bring a unique student-based perspective to teaching. With fewer years of teaching experience however, students who become involved in a facilitator role typically develop related skills quickly through a process of trial-and-error within the classroom. The…

  13. 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

  14. 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

  15. LIN28A facilitates the transformation of human neural stem cells and promotes glioblastoma tumorigenesis through a pro-invasive genetic program

    PubMed Central

    Mao, Xing-gang; Hütt-Cabezas, Marianne; Orr, Brent A.; Weingart, Melanie; Taylor, Isabella; Rajan, Anand K.D.; Odia, Yazmin; Kahlert, Ulf; Maciaczyk, Jarek; Nikkhah, Guido; Eberhart, Charles G.; Raabe, Eric H.

    2013-01-01

    The cellular reprogramming factor LIN28A promotes tumorigenicity in cancers arising outside the central nervous system, but its role in brain tumors is unknown. We detected LIN28A protein in a subset of human gliomas observed higher expression in glioblastoma (GBM) than in lower grade tumors. Knockdown of LIN28A using lentiviral shRNA in GBM cell lines inhibited their invasion, growth and clonogenicity. Expression of LIN28A in GBM cell lines increased the number and size of orthotopic xenograft tumors. LIN28A expression also enhanced the invasiveness of GBM cells in vitro and in vivo. Increasing LIN28A was associated with down-regulation of tumor suppressing microRNAs let-7b and let-7g and up-regulation of the chromatin modifying protein HMGA2. The increase in tumor cell aggressiveness in vivo and in vitro was accompanied by an upregulation of pro-invasive gene expression, including SNAI1. To further investigate the oncogenic potential of LIN28A, we infected hNSC with lentiviruses encoding LIN28A together with dominant negative R248W-TP53, constitutively active KRAS and hTERT. Resulting subclones proliferated at an increased rate and formed invasive GBM-like tumors in orthotopic xenografts in immunodeficient mice. Similar to LIN28A-transduced GBM neurosphere lines, hNSC-derived tumor cells showed increased expression of HMGA2. Taken together, these data suggest a role for LIN28A in high grade gliomas and illustrate an HMGA2-associated, pro-invasive program that can be activated in GBM by LIN28A-mediated suppression of let-7 microRNAs. PMID:23846349

  16. Reflections as near-peer facilitators of an inquiry project for undergraduate anatomy: Successes and challenges from a term of trial-and-error.

    PubMed

    Anstey, Lauren M; Michels, Alison; Szymus, Julianna; Law, Wyanne; Edwin Ho, Man-Hymn; Qu, Fei; Yeung, Ralph T T; Chow, Natalie

    2014-01-01

    Near-peer facilitators (senior students serving as facilitators to their more junior peers) bring a unique student-based perspective to teaching. With fewer years of teaching experience however, students who become involved in a facilitator role typically develop related skills quickly through a process of trial-and-error within the classroom. The aim of this paper is to report on the authors' own experiences and reflections as student near-peer facilitators for an inquiry-based project in an undergraduate anatomy course. Three areas of the facilitator experience are explored: (1) offering adequate guidance as facilitators of inquiry, (2) motivating students to engage in the inquiry process, and (3) fostering creativity in learning. A practical framework for providing guidance to students is discussed which offers facilitators a scaffold for asking questions and assisting students through the inquiry process. Considerations for stimulating intrinsic motivations toward inquiry learning are made, paying attention to ways in which facilitators might influence feelings of motivation towards learning. Also, the role of creativity in inquiry learning is explored by highlighting the actions facilitators can take to foster a creative learning environment. Finally, recommendations are made for the development of formalized training programs that aid near-peer facilitators in the acquisition of facilitation skills before entering into a process of trial-and-error within the classroom. PMID:23813933

  17. 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

  18. Three case studies of three high school teachers' definitions, beliefs, and implementation practices of inquiry-based science method including barriers to and facilitators of successful implementation

    NASA Astrophysics Data System (ADS)

    Blackburn-Morrison, Kimberly D.

    This study involved three teachers in various stages of implementation of inquiry-based science method. The cases were chosen because one participant was a novice in using inquiry-based science method, one participant was in her second year of implementation, and the third participant was experienced with inquiry-based science method. The cases were set in a rural high school in three different science classrooms. One of the classrooms was a regular biology class. One of the classrooms was an honors oceanography class and another was an advanced placement environmental science classroom. Data sources included interviews, observations, and document collection. Interviews, observations, and document collection were used to triangulate data. Each classroom was observed five times. Interviews were conducted at the beginning of the semester with each participant and at the end of the semester. Follow-up interviews were conducted after each observation. Documents were collected such as each teacher's lesson plans, student work, and assignments. Data was initially organized according to the research areas of teacher's definition, teacher's beliefs, teacher's barriers to implementation, and teacher's enablers to implementation. Then, patterns emerging from each of these cases were organized. Lastly, patterns emerging across cases were compared in a cross-case analysis. Patterns shared between cases were: Participants related inquiry-based science method with hands-on learning activities. Participants saw students as the center of the learning process. Participants had positive beliefs about constructivist learning practices that were strengthened after implementation of inquiry-based teaching. Facilitators of successful implementation of inquiry-based science method were positive student motivation, students' retention of knowledge, and a positive experience for lower level students. Barriers to successful implementation were teachers not having complete control of the

  19. 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

  20. 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

  1. 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

  2. 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

  3. 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

  4. 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

  5. Ancillary therapies to enhance success of non-invasive modes of respiratory support - Approaches to delivery room use of surfactant and caffeine?

    PubMed

    Kribs, Angela; Hummler, Helmut

    2016-06-01

    During recent decades, non-invasive respiratory support has become popular for treating neonates with respiratory failure. Several prospective randomized controlled trials have been performed to compare use of continuous positive airway pressure (CPAP) as primary respiratory support in preterm infants with respiratory distress syndrome (RDS) to endotracheal intubation, mechanical ventilation and surfactant therapy. Systematic reviews of these studies suggest that routine CPAP at delivery is efficacious in decreasing bronchopulmonary dysplasia (BPD), death, or both. This led to the recommendation to consider CPAP to avoid endotracheal intubation. As surfactant therapy is known to reduce BPD and death, several ways to combine CPAP with surfactant have been described. With the increasing use of CPAP immediately after birth, the early use of caffeine to stimulate respiration has become a point of discussion. This review focuses on different modes of surfactant application during CPAP and on the early use of caffeine as ancillary therapies to enhance CPAP success. PMID:26936187

  6. 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

  7. 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

  8. 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

  9. Collagen XVI Induces Expression of MMP9 via Modulation of AP-1 Transcription Factors and Facilitates Invasion of Oral Squamous Cell Carcinoma

    PubMed Central

    Bedal, Konstanze B.; Grässel, Susanne; Oefner, Peter J.; Reinders, Joerg; Reichert, Torsten E.; Bauer, Richard

    2014-01-01

    Collagen XVI belongs to the family of fibril-associated collagens with interrupted triple helices (FACIT). It is overexpressed during the progression of oral squamous cell carcinoma (OSCC). The present data show a strong collagen XVI-dependent induction of MMP9 and an increase in OSCC cell invasion. We found activated integrin-linked kinase (ILK) in a complex with kindlin-1 and activation of protein kinase B (PKB/Akt) to be responsible for MMP9 induction. Inhibition of the formation of focal adhesions reduced MMP9 expression. Moreover, collagen XVI overexpressing OSCC cell clones (COLXVI cell clones) transfected with vectors containing different MMP9 promoter fragments adjacent to a luciferase reporter revealed an increase in luciferase signal dependent on AP-1 binding sites. Deletion of the AP-1 binding site 98 bp upstream of the reported transcription start site and inhibition of AP-1 with Tanshinone IIA resulted in decreased MMP9 expression. The AP-1 subunit JunB showed differential expression between COLXVI cell clones and mock control cells. Additionally, mass spectrometric analysis of immunoprecipitates revealed that c-Fos interacted strongly with dyskerin in COLXVI cell clones compared to mock controls. PMID:24466237

  10. 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

  11. 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

  12. A unified approach for quantifying invasibility and degree of invasion.

    PubMed

    Guo, Qinfeng; Fei, Songlin; Dukes, Jeffrey S; Oswalt, Christopher M; Iannone, Basil V; Potter, Kevin M

    2015-10-01

    Habitat invasibility is a central focus of invasion biology, with implications for basic ecological patterns and processes and for effective invasion management. "Invasibility" is, however, one of the most elusive metrics and misused terms in ecology. Empirical studies and meta-analyses of invasibility have produced inconsistent and even conflicting results. This lack of consistency, and subsequent difficulty in making broad cross-habitat comparisons, stem in part from (1) the indiscriminant use of a closely related, but fundamentally different concept, that of degree of invasion (DI) or level of invasion; and (2) the lack of common invasibility metrics, as illustrated by our review of all invasibility-related papers published in 2013. To facilitate both cross-habitat comparison and more robust ecological generalizations, we clarify the definitions of invasibility and DI, and for the first time propose a common metric for quantifying invasibility based on a habitat's resource availability as inferred from relative resident species richness and biomass. We demonstrate the feasibility of our metric using empirical data collected from 2475 plots from three forest ecosystems in the eastern United States. We also propose a similar metric for DI. Our unified, resource-based metrics are scaled from 0 to 1, facilitating cross-habitat comparisons. Our proposed metrics clearly distinguish invasibility and DI from each other, which will help to (1) advance invasion ecology by allowing more robust testing of generalizations and (2) facilitate more effective invasive species control and management. PMID:26649383

  13. 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

  14. Regarding the role of new host associations in the success of Cactoblastis cactorum as both a biological control agent and invasive species.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A key theoretical basis for using classic biological control against invasive alien species (IAS) has been the enemy release hypothesis (ERH), which suggests that the increased vigor and invasiveness of IAS in the introduced range is strongly influenced by their release from co-evolved natural enemi...

  15. 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

  16. 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

  17. 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

  18. 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, III

    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.

  19. 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.

  20. 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

  1. 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

  2. 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 ...

  3. MARveling at parasite invasion.

    PubMed

    Hager, Kristin M; Carruthers, Vern B

    2008-02-01

    Micronemal proteins (MICs) are key mediators of cytoadherence and invasion for Toxoplasma gondii. Emerging evidence indicates that carbohydrate binding facilitates Toxoplasma entry into host cells. The recently solved Toxoplasma MIC1s (TgMIC1s) structure reveals the presence of novel specialized domains that can discriminate between glycan residues. Comparison with Plasmodium erythrocyte-binding antigen 175 reveals that terminal sialic acid residues might represent a shared but tailored invasion pathway among apicomplexan parasites. PMID:18203663

  4. 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...

  5. 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

  6. Invasion triangle: an organizational framework for species invasion

    PubMed Central

    Perkins, Lora B; Leger, Elizabeth A; Nowak, Robert S

    2011-01-01

    Species invasion is a complex, multifactor process. To encapsulate this complexity into an intuitively appealing, simple, and straightforward manner, we present an organizational framework in the form of an invasion triangle. The invasion triangle is an adaptation of the disease triangle used by plant pathologists to help envision and evaluate interactions among a host, a pathogen, and an environment. Our modification of this framework for invasive species incorporates the major processes that result in invasion as the three sides of the triangle: (1) attributes of the potential invader; (2) biotic characteristics of a potentially invaded site; and (3) environmental conditions of the site. The invasion triangle also includes the impact of external influences on each side of the triangle, such as climate and land use change. This paper introduces the invasion triangle, discusses how accepted invasion hypotheses are integrated in this framework, describes how the invasion triangle can be used to focus research and management, and provides examples of application. The framework provided by the invasion triangle is easy to use by both researchers and managers and also applicable at any level of data intensity, from expert opinion to highly controlled experiments. The organizational framework provided by the invasion triangle is beneficial for understanding and predicting why species are invasive in specific environments, for identifying knowledge gaps, for facilitating communication, and for directing management in regard to invasive species. PMID:22393528

  7. 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.

  8. 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…

  9. [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. PMID:27067860

  10. 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

  11. Noninvasive electrocardiomapping facilitates previously failed ablation of right appendage diverticulum associated life-threatening accessory pathway.

    PubMed

    Hocini, Mélèze; Shah, Ashok J; Cochet, Hubert; Maury, Philippe; Denis, Arnaud; Haïssaguerre, Michel

    2013-05-01

    Combination of structural (CT-scan) and functional (3D electrocardiomapping) imaging methods helped successfully accomplish ablation of a life-threatening manifest accessory pathway in association with a complex right atrial anomaly after previous unsuccessful attempts of endo-epicardial ablation guided by the invasive electroanatomic system in an adolescent female. Such a system has a potential to facilitate the ablation procedure and impact its outcome through accurate localization of the arrhythmogenic substrate. PMID:23252769

  12. 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

  13. 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

  14. The successful use of amphotericin B followed by oral posaconazole in a rare case of invasive fungal sinusitis caused by co-infection with mucormycosis and aspergillus

    PubMed Central

    Mahomed, Sharana; Basanth, Sujith; Mlisana, Koleka

    2015-01-01

    We report on an unusual case of oro-rhinocerebral disease caused by mucormycosis and aspergillus co-infection in a 54-year-old insulin dependent diabetic patient. Although she was successfully treated with parenteral amphotericin B followed by oral posaconazole, she was left with irreversible blindness of the right eye and multiple cranial nerve palsies. PMID:26793475

  15. 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 ...

  16. [Resource availability and its role in development of invasion processes].

    PubMed

    Kriksunov, E A; Bobyrev, A E; Burmenskiĭ, V A

    2010-01-01

    The state of biotic communities inhabiting different water bodies is analyzed aiming to determination of conditions facilitating development of biological invasions. Mass-balance and dynamic models are used to reveal the factors ensuring the invasion of zebra mussel, Dreissena polymorpha, in Naroch Lakes (Byelorussia), and smelt, Osmerus eperlanus, in Lake Syamozero (Karelia). The results obtained indicate that for invasions leading to trophic chain lengthening, the main factor of successful invasion is the availability of resources that are not utilized by aboriginal species. Highest chances for successful invasion belong to invading species feeding on those trophic groups which contribute to the most extent to forming of 'excess' (i.e., available for the invader) production. It is shown that establishment of an alien species in a native community appears to be possible only when total amount of such 'excess' production is higher then some threshold value. Under conditions of spatio-temporal environmental heterogeneity, the timing factor, which determines the exact moment of an alien species intrusion, becomes important as well. PMID:21061642

  17. Integrating biology into invasive species management is a key principle for eradication success: the case of yellow crazy ant Anoplolepis gracilipes in northern Australia.

    PubMed

    Hoffmann, B D

    2015-04-01

    The lack of biological knowledge of many invasive species remains as one of the greatest impediments to their management. Here I detail targeted research into the biology of the yellow crazy ant Anoplolepis gracilipes within northern Australia and detail how such knowledge can be used to improve the management outcomes for this species. I quantified nest location and density in three habitats, worker activity over 24 h, infestation expansion rate, seasonal variation of worker abundance and the timing of production of sexuals. Nests were predominantly (up to 68%) located at the bases of large trees, indicating that search efforts should focus around tree bases. Nest density was one nest per 22, 7.1 and 6.3 m2 in the three habitats, respectively. These data form the baselines for quantifying treatment efficacy and set sampling densities for post-treatment assessments. Most (60%) nests were underground, predominantly (89%) occurring in an open area rather than underneath a rock or log. Some seasonality was evident for nests within leaf litter, with most (83%) occurring during the 'wet season' (October-March). Of the underground nests, most were shallow, with 44% being less than 10 cm deep, and 67% being less than 20 cm deep. Such nest location and density information serves many management purposes, for improving detection, mapping and post-treatment assessments, and also provided strong evidence that carbohydrate supply was a major driver of A. gracilipes populations. Just over half of the nests (56%) contained queens. Of the 62 underground nests containing queens, most queens (80%) were located at the deepest chamber. When queens were present, most often (38%) only one queen was present, the most being 16. Queen number per nest was the lowest in July and August just prior to the emergence of virgin queens in September, with queen numbers then remaining steadily high until April. Nothing is known for any ant species about how the queen number per nest/colony affects

  18. 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

  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. 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.

  1. 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...

  2. 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

  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. Decidual Control of Trophoblast Invasion.

    PubMed

    Sharma, Shipra; Godbole, Geeta; Modi, Deepak

    2016-03-01

    At the time of implantation, the trophoblast cells of the embryo adhere and then invade into the maternal endometrium and eventually establish placentation. The endometrium at the same time undergoes decidualization, which is essential for successful pregnancy. While the NK cells of the decidua have been implicated to play a key role in trophoblast invasion, few evidence are now available to demonstrate a pro-invasive property of decidual stromal cells. Secretions from decidualized endometrial stromal cells promote invasion of primary trophoblasts and model cell lines by activating proteases and altering expression of adhesion-related molecules. The decidual secretions contain high amounts of pro-invasive factors that include IL-1β, IL-5, IL-6, IL-7, IL-8, IL-9, IL-13, IL-15, Eotaxin CCL11, IP-10 and RANTES, and anti-invasive factors IL-10, IL-12 and VEGF. It appears that these decidual factors promote invasion by regulating the protease pathways and integrin expression utilizing the STAT pathways in the trophoblast cells. At the same time the decidua also seem to secrete some anti-invasive factors that are antagonist to the matrix metalloproteinases and/or are activators of tissue inhibitors of metalloproteinases. This might be essential to neutralize the effects of the invasion-promoting factors and restrain overinvasion. It is tempting to propose that during the course of pregnancy, the decidua must balance the production of these pro and anti-invasive molecules and such harmonizing production would allow a timely and regulated invasion. PMID:26755153

  5. 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…

  6. The Zen of Facilitation.

    ERIC Educational Resources Information Center

    Killion, Joellen P.; Simmons, Lynn A.

    1992-01-01

    Distinguishes between training and facilitation, examines the belief system of a facilitator, and shares a process for moving from the familiar mind-set of the trainer to the zen (the practice of seeking the truth) of facilitation. (GLR)

  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. Immobilizing nitrogen to control plant invasion

    Technology Transfer Automated Retrieval System (TEKTRAN)

    1. Increased soil nitrogen (N) availability may often facilitate plant invasions. Therefore, lowering N availability might be expected to reduce those invasions and favor native species. Numerous studies have examined effects of low N availability on specific invaders, but a synthesis of these stu...

  9. 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

  10. 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

  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. Invasive mammals.

    PubMed

    Moutou, F; Pastoret, P P

    2010-08-01

    Every region of the world is concerned by potential mammal invasions, as humans are already present on all the world's land masses. All these invasions are a result of species introductions by humans for one reason or another. The authors briefly review the known movements and observed consequences of mammal-related invasions. They take examples from all five continents, as well as from a few island systems. The ancient introduction of game species, and later of domestic species, has been followed more recently by movements of commercial species. We are now seeing the emergence of what are known as entertainment species. In a number of cases, such introductions have led to the establishment of new epidemiological cycles that previously might never have been thought possible. According to current indicators, this phenomenon is not on the wane. PMID:20919577

  13. Looking at both sides of the invasion: patterns of colonization in the violet tunicate Botrylloides violaceus.

    PubMed

    Bock, D G; Zhan, A; Lejeusne, C; MacIsaac, H J; Cristescu, M E

    2011-02-01

    Understanding the ecological and evolutionary forces that shape the genetic structure of invasive populations and facilitate their expansion across a large spectrum of environments is critical for the prediction of spread and management of ongoing invasions. Here, we study the dynamics of postestablishment colonization in the colonial ascidian Botrylloides violaceus, a notorious marine invader. After its initial introduction from the Northwest Pacific, B. violaceus spread rapidly along the Pacific and Atlantic coasts of North America, impacting both aquaculture facilities and natural ecosystems. We compare genetic diversity and patterns of gene flow among 25 populations (N=679) from the West and East coasts, and evaluate the contribution of sexual vs. asexual reproduction to this species' invasion success using data from the mitochondrial cytochrome c oxidase subunit I (COI) gene and 13 nuclear polymorphic microsatellite loci. Our results reveal contrasting patterns of spread in the coastal waters of North America. While the West coast was colonized by noncontiguous (long-distance) dispersal, the East coast invasion appears to have occurred through contiguous (stepping-stone) spread. Molecular data further indicate that although dispersal in colonial ascidians is predominantly achieved through sexually produced propagules, aquaculture practices such as high-pressure washing can facilitate fragmentation and potentially exacerbate infestations and spread via asexual propagules. The results presented here suggest that caution should be used against the general assumption that all invasions, even within a single species, exhibit similar patterns of colonization, as highly contrasting dynamics may transpire in different invaded ranges. PMID:21199029

  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. Pronounced and prevalent intersexuality does not impede the 'Demon Shrimp' invasion.

    PubMed

    Green Etxabe, Amaia; Short, Stephen; Flood, Tim; Johns, Tim; Ford, Alex T

    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

  17. 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

  18. 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. PMID:25469955

  19. 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

  20. Invasive aspergillosis complicating Cushing's syndrome.

    PubMed

    Walsh, T J; Mendelsohn, G

    1981-08-01

    Patients with Cushing's syndrome are susceptible to opportunistic infections. Invasive fungal infections in patients with Cushing's syndrome caused by endogenous glucocorticoid excess rarely are reported, and aspergillosis occurring in this setting, to our knowledge, has not been described. Two patients with Cushing's syndrome and notably elevated levels of circulating cortisol had invasive aspergillosis develop. A patient with endogenous hypercortisolism caused by adrenal cortical carcinoma suffered a subarachnoid hemorrhage from rupture of an Aspergillus mycotic aneurysm. The other patient, who had an adrenocorticotrophic hormone-producing prostatic carcinoma, had pulmonary and disseminated aspergillosis develop. Exogenous corticosteroids are known clinically and experimentally to facilitate disseminated aspergillosis. Endogenous hypercortisolism also may bae an important factor predisposing to invasive aspergillosis. PMID:7259386

  1. 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. PMID:22251714

  2. 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

  3. 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...

  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. PMID:25611725

  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. 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…

  7. 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. PMID:23213366

  8. Invasive toads shift predator-prey densities in animal communities by removing top predators.

    PubMed

    Doody, J Sean; Soanes, Rebekah; Castellano, Christina M; Rhind, David; Green, Brian; McHenry, Colin R; Clulow, Simon

    2015-09-01

    Although invasive species can have substantial impacts on animal communities, cases of invasive species facilitating native species by removing their predators have rarely been demonstrated across vertebrate trophic linkages. The predictable spread of the invasive cane toad (Rhinella marina), however, offered a unique opportunity to quantify cascading effects. In northern Australia, three species of predatory monitor lizards suffered severe population declines due to toad-induced lethal toxic ingestion (yellow-spotted monitor (Varanus panoptes), Mertens' water monitor (V. mertensi), Mitchell's water monitor (V. mitchelli). We, thus, predicted subsequent increases in the abundance and recruitment of prey species due to the reduction of those predators. Toad-induced population-level declines in the water monitor species approached 50% over a five-year period spanning the toad invasion, apparently causing fledging success of the Crimson Finch (Neochmia.phaeton) to increase from 55% to 81%. The consensus of our original and published long-term data is that invasive cane toads are causing predators to lose a foothold on top-down regulation of their prey, triggering shifts in the relative densities of predator and prey in the Australian tropical savannah ecosystem. PMID:26594710

  9. 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

  10. 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.

  11. 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 ...

  12. Nitrogen acquisition by annual and perennial grass seedlings: testing the roles of performance and plasticity to explain plant invasion

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Differences in resource acquisition ability between native and exotic plants is one hypothesis to explain invasive plant success. Mechanisms include contrasting resource acquisition rates between native and invasive species, greater plasticity in resource acquisition by invasive species, and trade-...

  13. 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

  14. 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. PMID:26995099

  15. 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

  16. 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

  17. Microparasites and Placental Invasiveness in Eutherian Mammals

    PubMed Central

    Capellini, Isabella; Nunn, Charles L.; Barton, Robert A.

    2015-01-01

    Placental invasiveness—the number of maternal tissue layers separating fetal tissues from maternal blood—is variable across mammalian species. Although this diversity is likely to be functionally important, variation in placental invasiveness remains unexplained. Here we test the hypothesis that increased risk of transplacental transmission of pathogens from the mother to the fetus promotes the evolution of non-invasive placentation, the most likely derived condition in eutherian mammals. Specifically, we predict that non-invasive placentation is associated with increased microparasite species richness relative to more invasive placental types, based on the assumption that higher numbers of microparasites in a population reflects greater risk of transplacental transmission to fetuses. As predicted, higher bacteria species richness is associated with non-invasive placentation. Protozoa species richness, however, shows the opposite pattern. Because invasive placentae facilitate the transfer of maternal antibodies to the fetus, we propose that the ancestral condition of invasive placentation is retained under selection for protection of newborns from higher risk of postnatal protozoan infection. Hence, our findings suggest that a tradeoff exists between protection against bacterial infection prenatally and protozoan infection postnatally. Future studies are needed to investigate how maternal prevalence of infection and the relative pre- versus postnatal risk of fetal infection by different microparasite groups vary among mammalian hosts in relation to placental invasiveness. PMID:26168031

  18. Evidence that invasion by cheatgrass alters soil nitrogen availability

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Certain exotic plant species are known to engineer soil processes and thereby facilitate their competitive stature and invasiveness. In a well-characterized winterfat (Krascheninnikovia lanata) community in the Honey Lake Valley of northeastern CA, we tested if cheatgrass invasion (Bromus tectorum L...

  19. 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 ...

  20. A Quality Classroom: Quality Teaching Tools That Facilitate Student Success.

    ERIC Educational Resources Information Center

    Cooke, Brian

    This presentation described practical applications and quality tools for educators that are based on original classroom research and the theories of motivation, learning, profound knowledge, systems thinking, and service quality advanced by Karl Albrecht, William Glasser, and W. Edwards Deming. The presentation was conducted in a way that…

  1. 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…

  2. DO SUCCESSFUL STAKEHOLDER NEGOTIATIONS FACILITATE BELIEF CONSENSUS? (R825285)

    EPA Science Inventory

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  3. 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…

  4. 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

  5. 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

  6. 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

  7. Alien Invasions and the Game of Hide and Seek in Patagonia

    PubMed Central

    Lindegren, Martin; Vigliano, Pablo; Nilsson, P. Anders

    2012-01-01

    The introduction, establishment and spread of alien species is a major threat to biodiversity and the provision of ecosystem services for human wellbeing. In order to reduce further loss of biodiversity and maintain productive and sustainable ecosystems, understanding the ecological mechanisms underlying species invasions and avoiding potentially harmful effects on native communities is urgently needed, but largely lacking. We here demonstrate, by means of hydroacoustics and advanced spatial modelling, how native fish species as a result of previous exposure to native predators may successfully respond to invasive novel predators through a complicated game of hide and seek, minimizing spatio-temporal overlap with predators, and potentially facilitating coexistence between native prey species (Galaxiids) and introduced novel predators (Salmonids) in a deep Andean lake, Patagonia. PMID:23071496

  8. 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

  9. 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…

  10. 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. PMID:25421056

  11. 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

  12. 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.

  13. 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…

  14. 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…

  15. 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,…

  16. Action Research Facilitator's Handbook.

    ERIC Educational Resources Information Center

    Caro-Bruce, Cathy

    This handbook is a roadmap for action research facilitators to help groups as they work through the research process. It offers quotations, handouts, strategies, resources, and insights from actual experiences. The sections of the handbook follow the action research cycle, focusing on: "What is Action Research?"; "What is the Action Research…

  17. 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…

  18. Facilitating Strategy Transfer in College Reading Courses

    ERIC Educational Resources Information Center

    McGrath, Jane; Hamer, Arden

    2007-01-01

    The success of a developmental reading course really should be measured several semesters later by how well the students have transferred their new strategies to their content courses. To help facilitate this transfer, a list of ten instructional strategies are presented that have been developed from the literature and classroom experience.…

  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). PMID:17957337

  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. 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

  2. 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

  3. Invasive rodent eradication on islands.

    PubMed

    Howald, Gregg; Donlan, C Josh; Galván, Juan Pablo; Russell, James C; Parkes, John; Samaniego, Araceli; Wang, Yiwei; Veitch, Dick; Genovesi, Piero; Pascal, Michel; Saunders, Alan; Tershy, Bernie

    2007-10-01

    Invasive mammals are the greatest threat to island biodiversity and invasive rodents are likely responsible for the greatest number of extinctions and ecosystem changes. Techniques for eradicating rodents from islands were developed over 2 decades ago. Since that time there has been a significant development and application of this conservation tool. We reviewed the literature on invasive rodent eradications to assess its current state and identify actions to make it more effective. Worldwide, 332 successful rodent eradications have been undertaken; we identified 35 failed eradications and 20 campaigns of unknown result. Invasive rodents have been eradicated from 284 islands (47,628 ha). With the exception of two small islands, rodenticides were used in all eradication campaigns. Brodifacoum was used in 71% of campaigns and 91% of the total area treated. The most frequent rodenticide distribution methods (from most to least) are bait stations, hand broadcasting, and aerial broadcasting. Nevertheless, campaigns using aerial broadcast made up 76% of the total area treated. Mortality of native vertebrates due to nontarget poisoning has been documented, but affected species quickly recover to pre-eradication population levels or higher. A variety of methods have been developed to mitigate nontarget impacts, and applied research can further aid in minimizing impacts. Land managers should routinely remove invasive rodents from islands <100 ha that lack vertebrates susceptible to nontarget poisoning. For larger islands and those that require nontarget mitigation, expert consultation and greater planning effort are needed. With the exception of house mice (Mus musculus), island size may no longer be the limiting factor for rodent eradications; rather, social acceptance and funding may be the main challenges. To be successful, large-scale rodent campaigns should be integrated with programs to improve the livelihoods of residents, island biosecurity, and reinvasion response

  4. A resurrection study reveals rapid adaptive evolution within populations of an invasive plant

    PubMed Central

    Sultan, Sonia E; Horgan-Kobelski, Tim; Nichols, Lauren M; Riggs, Charlotte E; Waples, Ryan K

    2013-01-01

    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. PMID:23798976

  5. Community Ecology of Container Mosquitoes (Diptera: Culicidae) in Virginia Following Invasion by Aedes japonicus

    PubMed Central

    ARMISTEAD, JENNIFER S.; NISHIMURA, NAOYA; ARIAS, JORGE R.; LOUNIBOS, L. PHILIP

    2012-01-01

    The success of an invasive species in a new region depends on its interactions with ecologically similar resident species. Invasions by disease vector mosquitoes are important as they may have ecological and epidemiological consequences. Potential interactions of a recent invasive mosquito, Aedes japonicus Theobald, with resident species in Virginia were evaluated by sampling larvae from containers and trapping adults. Distinct species compositions were observed for artificial containers and rock pools, with Ae. albopictus most abundant in the former and Ae. japonicus in the latter. However, these two species were found to co-occur in 21.2% of containers sampled. Among the six mosquito species most common in containers from May through September, 2006, only interspecific associations of Ae.japonicus with Aedesalbopictus(Skuse) and Aedestriseriatus(Say) were significant, and both were negative. In addition to differences in habitat preference, mean crowding estimates suggest that interspecific repulsion may contribute to the significant negative associations observed between these species. High relative abundances of late instars and pupae of Ae. japonicus seem to provide this species with a mechanism of evading competition with Ae. albopictus, facilitating their coexistence in artificial containers. Although annual fluctuations were observed, trends in adult populations over a 6-yr period provide no evidence of declines. In summary, this survey of diverse container types and all life stages provided only limited evidence for competitive displacements or reductions of resident container species by Ae. japonicus, as observed elsewhere in its invasive range. PMID:23270159

  6. 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. PMID:25362583

  7. 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

  8. 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.

  9. 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

  10. 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. PMID:27152202

  11. 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

  12. 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

  13. The Principal as a Catalyst and Facilitator of Planned Change.

    ERIC Educational Resources Information Center

    Chamley, John; And Others

    1994-01-01

    Educational change must be facilitated, not dictated, to be successful. Since most new curriculum programs ignore complex classroom realities, teachers usually view them negatively. Facilitative principals create the necessary conditions for change by progressing through three stages: creating new roles and expectations, mobilizing proponents for…

  14. 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. PMID:16158250

  15. 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

  16. 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.

  17. 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.

  18. Favorable climate change response explains non-native species' success in Thoreau's woods.

    PubMed

    Willis, Charles G; Ruhfel, Brad R; Primack, Richard B; Miller-Rushing, Abraham J; Losos, Jonathan B; Davis, Charles C

    2010-01-01

    Invasive species have tremendous detrimental ecological and economic impacts. Climate change may exacerbate species invasions across communities if non-native species are better able to respond to climate changes than native species. Recent evidence indicates that species that respond to climate change by adjusting their phenology (i.e., the timing of seasonal activities, such as flowering) have historically increased in abundance. The extent to which non-native species success is similarly linked to a favorable climate change response, however, remains untested. We analyzed a dataset initiated by the conservationist Henry David Thoreau that documents the long-term phenological response of native and non-native plant species over the last 150 years from Concord, Massachusetts (USA). Our results demonstrate that non-native species, and invasive species in particular, have been far better able to respond to recent climate change by adjusting their flowering time. This demonstrates that climate change has likely played, and may continue to play, an important role in facilitating non-native species naturalization and invasion at the community level. PMID:20126652

  19. Minimally invasive follicular thyroid carcinomas: prognostic factors.

    PubMed

    Stenson, Gustav; Nilsson, Inga-Lena; Mu, Ninni; Larsson, Catharina; Lundgren, Catharina Ihre; Juhlin, C Christofer; Höög, Anders; Zedenius, Jan

    2016-08-01

    Although minimally invasive follicular thyroid carcinoma (MI-FTC) is regarded as an indolent tumour, treatment strategies remain controversial. Our aim was to investigate the outcome for patients with MI-FTC and to identify prognostic parameters to facilitate adequate treatment and follow-up. This retrospective follow-up study involved all cases of MI-FTC operated at the Karolinska University Hospital between 1986 and 2009. Outcome was analysed using death from MI-FTC as endpoint. Fifty-eight patients (41 women and 17 men) with MI-FTC were identified. The median follow-up time was 140 (range 21-308) months. Vascular invasion was observed in 36 cases and was associated with larger tumour size [median 40 (20-76) compared with 24 (10-80) mm for patients with capsular invasion only (P = 0.001)] and older patients [54 (20-92) vs. 44 (11-77) years; P = 0.019]. Patients with vascular invasion were more often treated with thyroidectomy (21/36 compared to 7/22 with capsular invasion only; P = 0.045). Five patients died from metastatic disease of FTC after a median follow-up of 114 (range 41-193) months; all were older than 50 years (51-72) at the time of the initial surgery; vascular invasion was present in all tumours and all but one were treated with thyroidectomy. Univariate analysis identified combined capsular and vascular invasion (P = 0.034), age at surgery ≥50 years (P = 0.023) and male gender (P = 0.005) as related to risk of death from MI-FTC. MI-FTC should not be considered a purely indolent disease. Age at diagnosis and the existence of combined capsular and vascular invasion were identified as important prognostic factors. PMID:26858184

  20. Project Success.

    ERIC Educational Resources Information Center

    Meredith, Larry D.

    Project Success consists of after-school, weekend, and summer educational programs geared toward minority and disadvantaged students to increase their numbers seeking postsecondary education from the Meadville, Pennsylvania area. The project is funded primarily through the Edinboro University of Pennsylvania, whose administration is committed to…

  1. 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

  2. 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

  3. Gradualness facilitates knowledge refinement.

    PubMed

    Rada, R

    1985-05-01

    To facilitate knowledge refinement, a system should be designed so that small changes in the knowledge correspond to small changes in the function or performance of the system. Two sets of experiments show the value of small, heuristically guided changes in a weighted rule base. In the first set, the ordering among numbers (reflecting certainties) makes their manipulation more straightforward than the manipulation of relationships. A simple credit assignment and weight adjustment strategy for improving numbers in a weighted, rule-based expert system is presented. In the second set, the rearrangement of predicates benefits from additional knowledge about the ``ordering'' among predicates. A third set of experiments indicates the importance of the proper level of granularity when augmenting a knowledge base. Augmentation of one knowledge base by analogical reasoning from another knowledge base did not work with only binary relationships, but did succeed with ternary relationships. To obtain a small improvement in the knowledge base, a substantial amount of structure had to be treated as a unit. PMID:21869290

  4. 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

  5. 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

  6. 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 ...

  7. 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…

  8. 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…

  9. 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

  10. 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

  11. 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

  12. 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.

  13. [Pulmonary non invasive infection by Scedosporium apiospermum].

    PubMed

    Cruz, Rodrigo; Barros, Manuel; Reyes, Mirtha

    2015-08-01

    We reported a case of non-invasive pulmonary infection by Scedosporium apiospermum in 67 years old female with bronchiectasis and caverns secondary to tuberculosis. Diagnosis was made with lung CT and bronchial lavage cultures. The patient was initially treated with itraconazole for six weeks without success and then voriconazole for 16 weeks, with good clinical response. PMID:26436797

  14. 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

  15. 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.…

  16. 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...

  17. Endemic predators, invasive prey and native diversity.

    PubMed

    Wanger, Thomas C; Wielgoss, Arno C; Motzke, Iris; Clough, Yann; Brook, Barry W; Sodhi, Navjot S; Tscharntke, Teja

    2011-03-01

    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

  18. 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

  19. LOUISIANA INVASIVE SPECIES PLAN

    EPA Science Inventory

    Identify the species, locations, and effects of invasive species within the state and the effects of these invasive species in Louisiana. Also identify how these species are spread, and the authorities that exist to manage and control them. With this information, create a m...

  20. Invasion of the Whiteflies

    Technology Transfer Automated Retrieval System (TEKTRAN)

    As invasive alien species spread, they often displace indigenous species, thus altering ecological communities and adversely affecting agricultural pest management, human health and well-being, and biodiversity. Despite the importance of invasive species, the processes enabling them to become estab...

  1. 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. PMID:24326694

  2. Cutaneous Squamous Cell Carcinoma with Invasion through Ear Cartilage

    PubMed Central

    Boisen, Julie; Malone, C. Helen; Kelly, Brent; Wagner, Richard F.

    2016-01-01

    Cutaneous squamous cell carcinoma of the ear represents a high-risk tumor location with an increased risk of metastasis and local tissue invasion. However, it is uncommon for these cancers to invade through nearby cartilage. Cartilage invasion is facilitated by matrix metalloproteases, specifically collagenase 3. We present the unusual case of a 76-year-old man with an auricular squamous cell carcinoma that exhibited full-thickness perforation of the scapha cartilage. Permanent sections through the eroded cartilage confirmed tumor invasion extending to the posterior ear skin. PMID:27293916

  3. 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

  4. 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

  5. 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

  6. 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.

  7. 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

  8. 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

  9. 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

  10. 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...

  11. 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. PMID:24197990

  12. Succession planning.

    PubMed

    Catanzaro, Thomas E

    2006-03-01

    This article provides the reader with an appreciation of the diverse elements that go into a buy-sell, affiliation, or merger situation for veterinary practices. In the changing market place of American veterinary medicine, old paradigms no longer hold comfort. The generational differences are briefly explored herein as well as the new economic realities. A few examples are offered to illustrate just how much variability exists in the current business of veterinary medicine and the subsequent practice transitions needed to enhance value. Functioning models are explored, as well as affiliation and merger options. Practice valuation is discussed in general terms, referencing the cutting-edge factors. The six-point summary provides almost all practices a solid operational base for daily operations and succession planning. PMID:16442447

  13. Current and future therapies for invasive aspergillosis.

    PubMed

    Bassetti, Matteo; Pecori, Davide; Della Siega, Paola; Corcione, Silvia; De Rosa, Francesco Giuseppe

    2015-06-01

    Invasive fungal infections have increase worldwide and represent a threat for immunocompromised patients including HIV-infected, recipients of solid organ and stem cell transplants, and patients receiving immunosuppressive therapies. High mortality rates and difficulties in early diagnosis characterize pulmonary fungal infections. Invasive pulmonary aspergillosis has been reviewed focussing on therapeutic management. Although new compounds have become available in the past years (i.e., amphotericin B lipid formulations, last-generation azoles, and echinocandines), new diagnostic tools and careful therapeutic management are mandatory to assure an early appropriate targeted treatment that represents the key factor for a successful conservative approach in respiratory fungal infections. PMID:24994691

  14. An assessment of invasion risk from assisted migration.

    PubMed

    Mueller, Jillian M; Hellmann, Jessica J

    2008-06-01

    To reduce the risk of extinction due to climate change, some ecologists have suggested human-aided translocation of species, or assisted migration (AM), to areas where climate is projected to become suitable. Such intentional movement, however, may create new invasive species if successful introductions grow out of control and cause ecologic or economic damage. We assessed this risk by surveying invasive species in the United States and categorizing invaders based on origin. Because AM will involve moving species on a regional scale within continents (i.e., range shifts), we used invasive species with an intracontinental origin as a proxy for species that would be moved through AM. We then determined whether intracontinental invasions were more prevalent or harmful than intercontinental invasions. Intracontinental invasions occurred far less frequently than invasions from other continents, but they were just as likely to have had severe effects. Fish and crustaceans pose a particularly high threat of intracontinental invasion. We conclude that the risk of AM to create novel invasive species is small, but assisted species that do become invasive could have large effects. Past experience with species reintroductions may help inform policy regarding AM. PMID:18577085

  15. 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…

  16. 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…

  17. 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...

  18. 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

  19. 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

  20. Successful Lecturing

    PubMed Central

    Copeland, H Liesel; Longworth, David L; Hewson, Mariana G; Stoller, James K

    2000-01-01

    OBJECTIVE In a study conducted over 3 large symposia on intensive review of internal medicine, we previously assessed the features that were most important to course participants in evaluating the quality of a lecture. In this study, we attempt to validate these observations by assessing prospectively the extent to which ratings of specific lecture features would predict the overall evaluation of lectures. MEASUREMENTS AND MAIN RESULTS After each lecture, 143 to 355 course participants rated the overall lecture quality of 69 speakers involved in a large symposium on intensive review of internal medicine. In addition, 7 selected participants and the course directors rated specific lecture features and overall quality for each speaker. The relations among the variables were assessed through Pearson correlation coefficients and cluster analysis. Regression analysis was performed to determine which features would predict the overall lecture quality ratings. The features that most highly correlated with ratings of overall lecture quality were the speaker's abilities to identify key points (r = .797) and be engaging (r = .782), the lecture clarity (r = .754), and the slide comprehensibility (r = .691) and format (r = .660). The three lecture features of engaging the audience, lecture clarity, and using a case-based format were identified through regression as the strongest predictors of overall lecture quality ratings (R2= 0.67, P = 0.0001). CONCLUSIONS We have identified core lecture features that positively affect the success of the lecture. We believe our findings are useful for lecturers wanting to improve their effectiveness and for educators who design continuing medical education curricula. PMID:10886470

  1. Minimally invasive hip replacement

    MedlinePlus

    ... Smits SA, Swinford RR, Bahamonde RE. A randomized, prospective study of 3 minimally invasive surgical approaches in total hip arthroplasty: comprehensive gait analysis. J Arthroplasty . 2008;23:68-73. PMID: 18722305 ...

  2. Molecular ecology of zebra mussel invasions.

    PubMed

    May, Gemma E; Gelembiuk, Gregory W; Panov, Vadim E; Orlova, Marina I; Lee, Carol Eunmi

    2006-04-01

    The invasion of the zebra mussel, Dreissena polymorpha, into North American waters has resulted in profound ecological disturbances and large monetary losses. This study examined the invasion history and patterns of genetic diversity among endemic and invading populations of zebra mussels using DNA sequences from the mitochondrial cytochrome oxidase I (COI) gene. Patterns of haplotype frequency indicate that all invasive populations of zebra mussels from North America and Europe originated from the Ponto-Caspian Sea region. The distribution of haplotypes was consistent with invasive populations arising from the Black Sea drainage, but could not exclude the possibility of an origin from the Caspian Sea drainage. Similar haplotype frequencies among North American populations of D. polymorpha suggest colonization by a single founding population. There was no evidence of invasive populations arising from tectonic lakes in Turkey, while lakes in Greece and Macedonia contained only Dreissena stankovici. Populations in Turkey might be members of a sibling species complex of D. polymorpha. Ponto-Caspian derived populations of D. polymorpha (theta = 0.0011) and Dreissena bugensis (one haplotype) exhibited low levels of genetic diversity at the COI gene, perhaps as a result of repeated population bottlenecks. In contrast, geographically isolated tectonic lake populations exhibited relatively high levels of genetic diversity (theta = 0.0032 to 0.0134). It is possible that the fluctuating environment of the Ponto-Caspian basin facilitated the colonizing habit of invasive populations of D. polymorpha and D. bugensis. Our findings were concordant with the general trend of destructive freshwater invaders in the Great Lakes arising from the Ponto-Caspian Sea basin. PMID:16599964

  3. 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...

  4. Evidence that invasion by cheatgrass (Bromus tectorum L.) increases soil nitrogen availability

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Certain exotic plant species are known to engineer soil processes and thereby facilitate their competitive stature and invasiveness. In a well-characterized winterfat (Krascheninnikovia lanata) community in the Honey Lake Valley of northeastern CA, we tested if cheatgrass invasion (Bromus tectorum L...

  5. Preimplantation factor (PIF) promotes human trophoblast invasion.

    PubMed

    Moindjie, Hadia; Santos, Esther Dos; Loeuillet, Laurence; Gronier, Héloise; de Mazancourt, Philippe; Barnea, Eytan R; Vialard, François; Dieudonne, Marie-Noëlle

    2014-11-01

    Preimplantation factor (PIF) is a peptide secreted by viable mammalian embryos. Moreover, it can be detected in the circulation of pregnant women. Recently, it was shown that PIF promotes invasion in trophoblast cell lines in vitro. Successful human embryo implantation depends on a deep and highly controlled invasion of extravillous trophoblast (EVT) in the maternal endometrium. Trophoblast invasion is regulated in part by matrix metalloproteinase (MMP) activity and integrin expression. The present study demonstrates the presence of PIF in early pregnancy and characterizes its effects on primary human trophoblast invasion. At the fetomaternal interface, intense PIF labeling by immunohistochemistry was present during early gestation in villous trophoblasts and EVTs. A decrease of labeling was observed at term. Furthermore, PIF significantly promoted invasion of human EVT isolated from first-trimester placenta. The proinvasive regulatory effect of PIF in EVT was associated with 1) increased MMP9 activity and 2) reduced tissue inhibitor of metalloproteinase-1 (TIMP1) mRNA expression. PIF also regulated alpha v and alpha 1 integrin mRNA expressions. Last, the proinvasive effect of PIF appeared to be mediated by the mitogen-activated protein kinase (MAPK), phosphoinositide-3-kinase (PI3K), and Janus-kinase signal transducer and activator of transcription (JAK-STAT) signaling pathways. In summary, this work describes the direct, positive effect of PIF on the control of human trophoblastic cell invasion by modulation of MMP/TIMP balance and integrin expression. Moreover, these results suggest that PIF is involved in pathological pregnancies characterized by insufficient or excessive trophoblast invasion. PMID:25232018

  6. 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

  7. Hybrid haplotype vigor in Florida (USA) populations of the invasive exotic Brazilian peppertree, Schinus terebinthifolius

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The process of invasive species establishment allows ecologists and evolutionary biologists to study these occurrences as human induced experiments in contemporary evolution. The success of invasive species exposes a genetic paradox. How can successful invaders overcome the hurdle of reduced genet...

  8. Collinear facilitation in color vision.

    PubMed

    Huang, Pi-Chun; Mullen, Kathy T; Hess, Robert F

    2007-01-01

    The detection of a luminance-defined Gabor is improved by two high contrast, aligned, flanking Gabors, an effect termed collinear facilitation. We investigate whether this facilitation also occurs for isoluminant chromatic stimuli, and whether it can occur for chromatic targets with luminance flanks and vice versa. We measured collinear facilitation for Gabor stimuli (0.75 cpd, 1 octave bandwidth) of three different contrast types: achromatic, red-green that isolates the L/M-cone opponent mechanism, and blue-yellow that isolates the S-cone opponent mechanism. Three conditions were investigated: (1) target and flanks all of the same contrast type and spatial phase; (2) target and flanks of the same contrast type but opposite phases (0 degrees and 180 degrees ); and (3) target and flanks of different contrast types (chromatic with achromatic contrast) and two opposite phase combinations. We find that a similar degree of collinear facilitation occurs for the isoluminant chromatic stimuli as for the achromatic stimuli, and all exhibit phase dependency. Facilitation did not occur, however, between chromatic and achromatic target and flanking stimuli. This suggests that at the level of collinear facilitation, the chromatic and the achromatic postreceptoral mechanisms have their own spatial interactions that are segregated from one another. PMID:17997661

  9. Minimally Invasive Spigelian Hernia Repair

    PubMed Central

    Baucom, Catherine; Nguyen, Quan D.; Hidalgo, Marco

    2009-01-01

    Introduction: Spigelian hernia is an uncommon ventral hernia characterized by a defect in the linea semilunaris. Repair of spigelian hernia has traditionally been accomplished via an open transverse incision and primary repair. The purpose of this article is to present 2 case reports of incarcerated spigelian hernia that were successfully repaired laparoscopically using Gortex mesh and to present a review of the literature regarding laparoscopic repair of spigelian hernias. Methods: Retrospective chart review and Medline literature search. Results: Two patients underwent laparoscopic mesh repair of incarcerated spigelian hernias. Both were started on a regular diet on postoperative day 1 and discharged on postoperative days 2 and 3. One patient developed a seroma that resolved without intervention. There was complete resolution of preoperative symptoms at the 12-month follow-up. Conclusion: Minimally invasive repair of spigelian hernias is an alternative to the traditional open surgical technique. Further studies are needed to directly compare the open and the laparoscopic repair. PMID:19660230

  10. Invasive aspergillosis: new insights into disease, diagnostic and treatment.

    PubMed

    Karthaus, Meinolf; Buchheidt, Dieter

    2013-01-01

    Aspergillus infections are a threat to in patients with hematological malignancies. Known risk factors are profound and long lasting neutropenia, uncontrolled graft versus host disease, continuous administration of steroids and environmental factors such as hospital construction. Numerous efforts have been undertaken for prophylaxis of invasive aspergillosis in high-risk populations. Most of them failed to demonstrate survival advantages. Prophylaxis makes sense, since diagnosis and treatment of invasive aspergillosis remain difficult. The introduction of non-culture based tools for the diagnosis of invasive aspergillosis is an important step forward for early and sensitive diagnosis of invasive aspergillosis. Early treatment is the cornerstone of a successful management of invasive aspergillosis. Substantial improvement came with the introduction of lipid formulations of amphotericin B in the early 1990s. Voriconazole was the first azole that improved the overall survival for patients with invasive aspergillosis. Newer azoles and the echinocandins were introduced for the treatment of invasive aspergillosis in the late 1990s. Voriconazole and liposomal amphotericin B allow a safer and more effective treatment of invasive aspergillosis when compared with amphotericin B-desoxycholate. Combination of antifungal agents has been introduced in clinical trials. Up to now no significant benefit has been obtained with antifungal combination compared to voriconazole alone. Because mortality of invasive aspergillosis remains up to more than 50%, prophylaxis, early diagnosis and early initiation of antifungal therapy are of utmost importance for the reduction of invasive aspergillosis related mortality. Despite all advances in the management of invasive aspergillosis important questions remain unresolved. This article reviews the current state and new insights in the management of invasive aspergillosis and points out clinicians unmet needs. PMID:23278538

  11. 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

  12. 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

  13. 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

  14. A Practical and Less Invasive Total Cavopulmonary Connection Sheep Model

    PubMed Central

    Wang, Dongfang; Plunkett, Mark; Gao, Guodong; Zhou, Xiaoqin; Ballard-Croft, Cherry; Reda, Hassan; Zwischenberger, Joseph B.

    2016-01-01

    Our goal is to develop a less invasive total cavopulmonary connection (TCPC) sheep model for testing total cavopulmonary assist (CPA) devices. Thirteen sheep underwent a right 4th intercostal lateral thoracotomy. In series I (n=6), a polytetrafluoroethylene (PTFE) extracardiac conduit (ECC) was connected to inferior vena cava (IVC) and superior vena cava (SVC) by end to side anastomosis. The SVC/IVC remained connected to right atrium (RA). A PTFE graft bridged ECC to right pulmonary artery (RPA). Clamps between SVC/IVC anastomoses and RA diverted total venous blood to pulmonary circulation. In series II (n=7), temporary bypasses between SVC/IVC to RA allowed SVC/IVC to be cut off from RA for better RPA exposure. The ECC-SVC/IVC were end-end anastomosed and ECC-RPA side-side anastomosed for total SVC/IVC to PA conversion. In each series, one sheep died of bleeding. In 5 sheep in series I and 6 sheep in series II, the TCPC model was successfully created with significantly increased central venous pressure and significantly decreased pulmonary artery pressure/arterial blood pressure. Our acute TCPC sheep model has a less traumatic right thoracotomy with no cardiopulmonary bypass and less blood loss with no blood transfusion, facilitating future long-term CPA device evaluation. PMID:24399067

  15. 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.

  16. Linkages of plant-soil feedbacks and underlying invasion mechanisms.

    PubMed

    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

  17. 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.

  18. 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.

  19. 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

  20. 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

  1. Mechanisms of Perineural Invasion.

    PubMed

    Bakst, Richard L; Wong, Richard J

    2016-04-01

    Perineural invasion (PNI) is the neoplastic invasion of nerves. PNI is widely recognized as an important adverse pathological feature of many malignancies, including pancreatic, prostate, and head and neck cancers and is associated with a poor prognosis. Despite widespread acknowledgment of the clinical significance of PNI, the mechanisms underlying its pathogenesis remain largely unknown. Recent theories of PNI pathogenesis have placed a significant emphasis on the active role of the nerve microenvironment, with PNI resulting from well-orchestrated reciprocal interactions between cancer and host. Elucidating the mechanisms involved in PNI may translate into targeted therapies for this ominous process. PMID:27123385

  2. Minimally Invasive Radiofrequency Devices.

    PubMed

    Sadick, Neil; Rothaus, Kenneth O

    2016-07-01

    This article reviews minimally invasive radiofrequency options for skin tightening, focusing on describing their mechanism of action and clinical profile in terms of safety and efficacy and presenting peer-reviewed articles associated with the specific technologies. Treatments offered by minimally invasive radiofrequency devices (fractional, microneedling, temperature-controlled) are increasing in popularity due to the dramatic effects they can have without requiring skin excision, downtime, or even extreme financial burden from the patient's perspective. Clinical applications thus far have yielded impressive results in treating signs of the aging face and neck, either as stand-alone or as postoperative maintenance treatments. PMID:27363771

  3. Facilitation of learning: part 1.

    PubMed

    Warburton, Tyler; Trish, Houghton; Barry, Debbie

    2016-04-01

    This article, the fourth in a series of 11, discusses the context for the facilitation of learning. It outlines the main principles and theories for understanding the process of learning, including examples which link these concepts to practice. The practical aspects of using these theories in a practice setting will be discussed in the fifth article of this series. Together, these two articles will provide mentors and practice teachers with knowledge of the learning process, which will enable them to meet the second domain of the Nursing and Midwifery Council's Standards to Support Learning and Assessment in Practice on facilitation of learning. PMID:27050014

  4. Osteopontin Is Expressed in the Mouse Uterus during Early Pregnancy and Promotes Mouse Blastocyst Attachment and Invasion In Vitro

    PubMed Central

    Qi, Qian-Rong; Xie, Qing-Zhen; Liu, Xue-Li; Zhou, Yun

    2014-01-01

    Embryo implantation into the maternal uterus is a decisive step for successful mammalian pregnancy. Osteopontin (OPN) is a member of the small integrin-binding ligand N-linked glycoprotein family and participates in cell adhesion and invasion. In this study, we showed that Opn mRNA levels are up-regulated in the mouse uterus on day 4 and at the implantation sites on days 5 and 8 of pregnancy. Immunohistochemistry localized the OPN protein to the glandular epithelium on day 4 and to the decidual zone on day 8 of pregnancy. OPN mRNA and proteins are induced by in vivo and in vitro decidualization. OPN expression in the endometrial stromal cells is regulated by progesterone, a key regulator during decidualization. As a secreted protein, the protein level of OPN in the uterine cavity is enriched on day 4, and in vitro embryo culturing has indicated that OPN can facilitate blastocyst hatching and adhesion. Knockdown of OPN attenuates the adhesion and invasion of blastocysts in mouse endometrial stromal cells by suppressing the expression and enzymatic activity of matrix metalloproteinase-9 in the trophoblast. Our data indicated that OPN expression in the mouse uterus during early pregnancy is essential for blastocyst hatching and adhesion and that the knockdown of OPN in mouse endometrial stroma cells could lead to a restrained in vitro trophoblast invasion. PMID:25133541

  5. Earthworm invasion as the driving force behind plant invasion and community change in northeastern North American forests.

    PubMed

    Nuzzo, Victoria A; Maerz, John C; Blossey, Bernd

    2009-08-01

    Identification of factors that drive changes in plant community structure and contribute to decline and endangerment of native plant species is essential to the development of appropriate management strategies. Introduced species are assumed to be driving causes of shifts in native plant communities, but unequivocal evidence supporting this view is frequently lacking. We measured native vegetation, non-native earthworm biomass, and leaf-litter volume in 15 forests in the presence and absence of 3 non-native plant species (Microstegium vimineum, Alliaria petiolata, Berberis thunbergii) to assess the general impact of non-native plant and earthworm invasions on native plant communities in northeastern United States. Non-native plant cover was positively correlated with total native plant cover and non-native earthworm biomass. Earthworm biomass was negatively associated with cover of native woody and most herbaceous plants and with litter volume. Graminoid cover was positively associated with non-native earthworm biomass and non-native plant cover. These earthworm-associated responses were detected at all sites despite differences in earthworm species and abundance, composition of the native plant community, identity of invasive plant species, and geographic region. These patterns suggest earthworm invasion, rather than non-native plant invasion, is the driving force behind changes in forest plant communities in northeastern North America, including declines in native plant species, and earthworm invasions appear to facilitate plant invasions in these forests. Thus, a focus on management of invasive plant species may be insufficient to protect northeastern forest understory species. PMID:19236448

  6. 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

  7. Diagnostic methods for invasive fungal diseases in patients with hematologic malignancies

    PubMed Central

    Riwes, Mary Mansour; Wingard, John R

    2013-01-01

    Invasive fungal disease is associated with increased morbidity and mortality in hematologic malignancy patients and hematopoietic stem cell transplant recipients. Timely recognition and treatment of invasive fungal diseases in these patients are essential and decrease mortality. However, conventional definitive diagnostic methods are difficult and time consuming. While conventional microbiological and histopathological methods are still needed for a definitive diagnosis of invasive fungal disease, new noninvasive diagnostic methods including serologic and molecular biomarkers are now available. These new diagnostic methods facilitate an early diagnosis of invasive fungal disease and allow for utilization of a pre-emptive treatment approach, which may ultimately lead to improved treatment outcomes and reduced toxicity. PMID:23216596

  8. 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…

  9. Mechanisms Regulating Glioma Invasion

    PubMed Central

    Paw, Ivy; Carpenter, Richard C.; Watabe, Kounosuke; Debinski, Waldemar; Lo, Hui-Wen

    2015-01-01

    Glioblastoma (GBM) is the most aggressive, deadliest, and most common brain malignancy in adults. Despite the advances made in surgical techniques, radiotherapy and chemotherapy, the median survival for GBM patients has remained at a mere 14 months. GBM poses several unique challenges to currently available treatments for the disease. For example, GBM cells have the propensity to aggressively infiltrate/invade into the normal brain tissues and along the vascular tracks, which prevents complete resection of all malignant cells and limits the effect of localized radiotherapy while sparing normal tissue. Although anti-angiogenic treatment exerts anti-edematic effect in GBM, unfortunately, tumors progress with acquired increased invasiveness. Therefore, it is an important task to gain a deeper understanding of the intrinsic and post-treatment invasive phenotypes of GBM in hopes that the gained knowledge would lead to novel GBM treatments that are more effective and less toxic. This review will give an overview of some of the signaling pathways that have been shown to positively and negatively regulate GBM invasion, including, the PI3K/Akt, Wnt, sonic hedgehog-GLI1, and microRNAs. The review will also discuss several approaches to cancer therapies potentially altering GBM invasiveness. PMID:25796440

  10. Porocarcinoma with perineural invasion

    PubMed Central

    Maguire, Ciara A.; Kazlouskaya, Viktoryia; Buchen, Daniel; Heller, Patricia; Elston, Dirk M.

    2015-01-01

    Herein we present the case of a 58 year old woman with porocarcinoma of the left forehead with perineural invasion, diagnosed after recurrence of previously excised benign poroma. This case serves as a reminder of the potential of malignant degeneration within long-standing benign adnexal tumors as well as the spectrum of histological features that may be seen in porocarcinoma. PMID:25821737

  11. 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.

  12. 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

  13. Facilitating Conditions for School Motivation.

    ERIC Educational Resources Information Center

    Yeung, Alexander Seeshing; McInerney, Dennis M.

    Primary and high school students (277 in grades 5-6; 615 in grades 7-12) in the United States (47 percent boys) responded to 26 items of the Facilitating Conditions Questionnaire (FCQ). Results indicate 7 distinct FCQ factors: perceived value of schooling; affect toward schooling; peer positive academic climate (Peer Positive); encouragement from…

  14. 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 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. SUPERFUND GROUNDWATER ISSUE - FACILITATED TRANSPORT

    EPA Science Inventory

    The Regional Superfund Ground Water Forum is a group of ground-water scientists representing EPA's Regional Superfund Offices, organized to exchange up to date information related to ground-water remediation at Superfund sites. Facilitated transport is an issue identified by the ...

  16. Facilitation of Mourning During Childhood.

    ERIC Educational Resources Information Center

    Kliman, Gilbert; And Others

    This paper discusses case studies of children psychologically disturbed by the death of parents or siblings. Illustrations of mourning facilitation were mainly gathered from 16 orphaned children, ages 3-14. Some techniques used in helping children mourn include: discussing physical details of the illness, discussing previous deaths of animals and…

  17. Casebook of Selected State Facilitators.

    ERIC Educational Resources Information Center

    Network of Innovative Schools, Inc., Andover, MA.

    The U.S. Office of Education's National Diffusion Network is designed to transport and systematically promote the adoption of validated innovative programs throughout the nation. The 13 case studies in this publication are intended to provide a comprehensive overview of the state facilitator effort and accurately represent the range and diversity…

  18. Technology Alone Won't Transform Teacher to Facilitator

    ERIC Educational Resources Information Center

    Martinez, Monica; McGrath, Dennis

    2014-01-01

    Technology alone won't be enough to improve teaching and learning to where it needs to be for 21st century skills. Where it is being done successfully, teachers collectively share a vision of promoting deeper learning in all their students, and have collaboratively redesigned the role of the teacher to that of facilitator who uses technology…

  19. Facilitating Interdisciplinary Work: Using Quality Assessment to Create Common Ground

    ERIC Educational Resources Information Center

    Oberg, Gunilla

    2009-01-01

    Newcomers often underestimate the challenges of interdisciplinary work and, as a rule, do not spend sufficient time to allow them to overcome differences and create common ground, which in turn leads to frustration, unresolved conflicts, and, in the worst case scenario, discontinued work. The key to successful collaboration is to facilitate the…

  20. Facilitating the Development of Proportional Reasoning through Teaching Ratio

    ERIC Educational Resources Information Center

    Parish, Linda

    2010-01-01

    If the ability to reason proportionally seems to be a good indication of likely success in further mathematical pursuits (Lamon, 1999), how do children develop this ability, and how can teachers facilitate this? In this present study, six ratio/rates task-based assessment questions were trialled on ten students from Grades 5 to 9 in an attempt to…

  1. Revegetation potential of Great Basin native annuals and perennial grasses: Does facilitation occur?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Revegetation of degraded Great Basin rangelands is a challenging task. In an already unforgiving environment the addition of exotic invasive annual weeds, such as cheatgrass (Bromus tectorum) have added to this challenge. Increasing interest in plant facilitation research has suggested using nati...

  2. 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. PMID:22006283

  3. 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.

  4. Herbivores mediate different competitive and facilitative responses of native and invader populations of Brassica nigra.

    PubMed

    Oduor, Ayub M O; Strauss, Sharon Y; García, Yedra; Cascales, Modesto Berbel; Gómez, José M

    2013-10-01

    Differences in plant and herbivore community assemblages between exotic and native ranges may select for different levels of plant traits in invasive and native populations of plant species. Little is currently known of how herbivores may mediate competitive and facilitative interactions between invasive and native populations of plant species and their plant neighbors. Here, we conducted a common-garden field experiment to test whether invasive and native populations of Brassica nigra differ in phenotypic expressions of growth (biomass and plant height) and reproductive (seed yield) traits under different plant neighbor treatments and ambient vs. reduced level of insect herbivore damage on the B. nigra plants. We found significant interactive effects of plant neighbor treatments, level of insect herbivore damage on B. nigra plants, and invasive status of B. nigra on the phenotypic trait expressions. Plant neighbor treatments had minimal effects on phenotypic trait expressions by invasive populations of B. nigra under either level of insect herbivore damage. In contrast, for native populations of B. nigra, ambient level of insect herbivore damage resulted in plant neighbors facilitating expression of the traits above, while reduced damage resulted in plant neighbors competitively suppressing trait expression. Our results suggest that insect herbivores and plant neighbors interactively shape expression of plant traits in native and exotic ranges of invasive plants. Such interactions could potentially lead to different selection pressures on traits that determine antiherbivore defenses and plant-plant interactions. PMID:24358714

  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. 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

  7. 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.

  8. Genetic Perspectives on Marine Biological Invasions

    NASA Astrophysics Data System (ADS)

    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.

  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, III; 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. 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. PMID:26390918

  11. Planning for Youth Success: Resource and Training Manual. Connecting Schools, Families, and Communities for Youth Success.

    ERIC Educational Resources Information Center

    Dorfman, Diane; Douglas, Randi; Ellis, Debbie; Fisher, Amy; Geiger, Elke; Hughes, Kendra; Ko, Lena; Saifer, Steffen

    This manual is designed to assist facilitators working with members of a school community in forming or strengthening partnerships that will promote greater success for their youth. Participants can identify characteristics that are most important for youth to be successful in their community, consider ways to determine that students are…

  12. [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

  13. Analysis of the Transcriptional Differences between Indigenous and Invasive Whiteflies Reveals Possible Mechanisms of Whitefly Invasion

    PubMed Central

    Wang, Yong-Liang; Wang, Yu-Jun; Luan, Jun-Bo; Yan, Gen-Hong; Liu, Shu-Sheng; Wang, Xiao-Wei

    2013-01-01

    Background The whitefly Bemisa tabaci is a species complex of more than 31 cryptic species which include some of the most destructive invasive pests of crops worldwide. Among them, Middle East-Asia Minor 1 (MEAM1) and Mediterranean have invaded many countries and displaced the native whitefly species. The successful invasion of the two species is largely due to their wide range of host plants, high resistance to insecticides and remarkable tolerance to environmental stresses. However, the molecular differences between invasive and indigenous whiteflies remain largely unknown. Methodology/Principal Findings Here the global transcriptional difference between the two invasive whitefly species (MEAM1, MED) and one indigenous whitefly species (Asia II 3) were analyzed using the Illumina sequencing. Our analysis indicated that 2,422 genes between MEAM1 and MED; 3,073 genes between MEAM1 and Asia II 3; and 3,644 genes between MED and Asia II 3 were differentially expressed. Gene Ontology enrichment analysis revealed that the differently expressed genes between the invasive and indigenous whiteflies were significantly enriched in the term of ‘oxidoreductase activity’. Pathway enrichment analysis showed that carbohydrate, amino acid and glycerolipid metabolisms were more active in MEAM1 and MED than in Asia II 3, which may contribute to their differences in biological characteristics. Our analysis also illustrated that the majority of genes involved in ‘drug metabolic pathway’ were expressed at a higher level in MEAM1 and MED than in Asia II 3. Taken together, these results revealed that the genes related to basic metabolism and detoxification were expressed at an elevated level in the invasive whiteflies, which might be responsible for their higher resistance to insecticides and environmental stresses. Conclusions/Significance The extensive comparison of MEAM1, MED and Asia II 3 gene expression may serve as an invaluable resource for revealing the molecular

  14. Facilitating Facilitators to Facilitate, in Problem or Enquiry Based Learning Sessions

    ERIC Educational Resources Information Center

    Coelho, Catherine

    2014-01-01

    Problem based learning (PBL) has been used in dental education over the past 20 years and uses a patient case scenario to stimulate learning in a small group setting, where a trained facilitator does not teach but guides the group to bring about deep contextualized learning, to be empathetic to each other and to encourage fair and equitable…

  15. Corticotomy facilitated orthodontics: Review of a technique.

    PubMed

    Alghamdi, Ali Saad Thafeed

    2010-01-01

    Corticotomy found to be effective in accelerating orthodontic treatment. The most important factors in the success of this technique is proper case selection and careful surgical and orthodontic treatment. Corticotomy facilitated orthodontics advocated for comprehensive fixed orthodontic appliances in conjunction with full thickness flaps and labial and lingual corticotomies around teeth to be moved. Bone graft should be applied directly over the bone cuts and the flap sutured in place. Tooth movement should be initiated two weeks after the surgery, and every two weeks thereafter by activation of the orthodontic appliance. Orthodontic treatment time with this technique will be reduced to one-third the time of conventional orthodontics. Alveolar augmentation of labial and lingual cortical plates were used in an effort to enhance and strengthen the periodontium, reasoning that the addition of bone to alveolar housing of the teeth, using modern bone grafting techniques, ensures root coverage as the dental arch expanded. Corticotomy facilitated orthodontics is promising procedure but only few cases were reported in the literature. Controlled clinical and histological studies are needed to understand the biology of tooth movement with this procedure, the effect on teeth and bone, post-retention stability, measuring the volume of mature bone formation, and determining the status of the periodontium and roots after treatment. PMID:23960473

  16. Corticotomy facilitated orthodontics: Review of a technique

    PubMed Central

    AlGhamdi, Ali Saad Thafeed

    2009-01-01

    Corticotomy found to be effective in accelerating orthodontic treatment. The most important factors in the success of this technique is proper case selection and careful surgical and orthodontic treatment. Corticotomy facilitated orthodontics advocated for comprehensive fixed orthodontic appliances in conjunction with full thickness flaps and labial and lingual corticotomies around teeth to be moved. Bone graft should be applied directly over the bone cuts and the flap sutured in place. Tooth movement should be initiated two weeks after the surgery, and every two weeks thereafter by activation of the orthodontic appliance. Orthodontic treatment time with this technique will be reduced to one-third the time of conventional orthodontics. Alveolar augmentation of labial and lingual cortical plates were used in an effort to enhance and strengthen the periodontium, reasoning that the addition of bone to alveolar housing of the teeth, using modern bone grafting techniques, ensures root coverage as the dental arch expanded. Corticotomy facilitated orthodontics is promising procedure but only few cases were reported in the literature. Controlled clinical and histological studies are needed to understand the biology of tooth movement with this procedure, the effect on teeth and bone, post-retention stability, measuring the volume of mature bone formation, and determining the status of the periodontium and roots after treatment. PMID:23960473

  17. 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. PMID:25481818

  18. Role of "external facilitation" in implementation of research findings: a qualitative evaluation of facilitation experiences in the Veterans Health Administration

    PubMed Central

    Stetler, Cheryl B; Legro, Marcia W; Rycroft-Malone, Joanne; Bowman, Candice; Curran, Geoffrey; Guihan, Marylou; Hagedorn, Hildi; Pineros, Sandra; Wallace, Carolyn M

    2006-01-01

    Background Facilitation has been identified in the literature as a potentially key component of successful implementation. It has not, however, either been well-defined or well-studied. Significant questions remain about the operational definition of facilitation and about the relationship of facilitation to other interventions, especially to other change agent roles when used in multi-faceted implementation projects. Researchers who are part of the Quality Enhancement Research Initiative (QUERI) are actively exploring various approaches and processes, including facilitation, to enable implementation of best practices in the Veterans Health Administration health care system – the largest integrated healthcare system in the United States. This paper describes a systematic, retrospective evaluation of implementation-related facilitation experiences within QUERI, a quality improvement program developed by the US Department of Veterans Affairs. Methods A post-hoc evaluation was conducted through a series of semi-structured interviews to examine the concept of facilitation across several multi-site QUERI implementation studies. The interview process is based on a technique developed in the field of education, which systematically enhances learning through experience by stimulating recall and reflection regarding past complex activities. An iterative content analysis approach relative to a set of conceptually-based interview questions was used for data analysis. Findings Findings suggest that facilitation, within an implementation study initiated by a central change agency, is a deliberate and valued process of interactive problem solving and support that occurs in the context of a recognized need for improvement and a supportive interpersonal relationship. Facilitation was described primarily as a distinct role with a number of potentially crucial behaviors and activities. Data further suggest that external facilitators were likely to use or integrate other

  19. Characteristic sounds facilitate visual search.

    PubMed

    Iordanescu, Lucica; Guzman-Martinez, Emmanuel; Grabowecky, Marcia; Suzuki, Satoru

    2008-06-01

    In a natural environment, objects that we look for often make characteristic sounds. A hiding cat may meow, or the keys in the cluttered drawer may jingle when moved. Using a visual search paradigm, we demonstrated that characteristic sounds facilitated visual localization of objects, even when the sounds carried no location information. For example, finding a cat was faster when participants heard a meow sound. In contrast, sounds had no effect when participants searched for names rather than pictures of objects. For example, hearing "meow" did not facilitate localization of the word cat. These results suggest that characteristic sounds cross-modally enhance visual (rather than conceptual) processing of the corresponding objects. Our behavioral demonstration of object-based cross-modal enhancement complements the extensive literature on space-based cross-modal interactions. When looking for your keys next time, you might want to play jingling sounds. PMID:18567253

  20. Counterfactual Thinking Facilitates Behavioral Intentions

    PubMed Central

    Smallman, Rachel; Roese, Neal J.

    2009-01-01

    People often ponder what might have been, and these counterfactual inferences have been linked to behavior regulation. Counterfactuals may enhance performance by either a content-specific pathway (via shift in behavioral intentions) and/or a content-neutral pathway (via mindsets or motivation). Three experiments provided new specification of the content-specific pathway. A sequential priming paradigm revealed that counterfactual judgments facilitated RTs to complete behavioral intention judgments relative to control judgments and to a no-judgment baseline (Experiment 1). This facilitation effect was found only for intention judgments that matched the information content of the counterfactual (Experiment 2) and only for intention judgments as opposed to a different judgment that nevertheless focused on the same information content (Experiment 3). These findings clarify the content-specific pathway by which counterfactuals influence behavior. PMID:20161221

  1. The menopause: stressors and facilitators.

    PubMed Central

    el-Guebaly, N; Atchison, B; Hay, W

    1984-01-01

    Between about ages 40 and 55 years, women experience a transition known as the menopause, which marks the end of their childbearing years. Although the most striking feature of the menopause is the cessation of menstruation, other biologic and psychosocial events occur and can be classified as stressors and "facilitators". For a predisposed group of women the stressors are likely to cause psychiatric disorders. At the same time, the facilitators are opportunities for personal growth and development. Physicians who understand both types of events during this phase of life and who are sensitive to the overall effects of ageing on marital partners can provide comprehensive care to the menopausal patient rather than automatically pursuing drug therapy (substitution hormonal therapy) alone. PMID:6488116

  2. In Vivo Facilitated Diffusion Model

    PubMed Central

    Bauer, Maximilian; Metzler, Ralf

    2013-01-01

    Under dilute in vitro conditions transcription factors rapidly locate their target sequence on DNA by using the facilitated diffusion mechanism. However, whether this strategy of alternating between three-dimensional bulk diffusion and one-dimensional sliding along the DNA contour is still beneficial in the crowded interior of cells is highly disputed. Here we use a simple model for the bacterial genome inside the cell and present a semi-analytical model for the in vivo target search of transcription factors within the facilitated diffusion framework. Without having to resort to extensive simulations we determine the mean search time of a lac repressor in a living E. coli cell by including parameters deduced from experimental measurements. The results agree very well with experimental findings, and thus the facilitated diffusion picture emerges as a quantitative approach to gene regulation in living bacteria cells. Furthermore we see that the search time is not very sensitive to the parameters characterizing the DNA configuration and that the cell seems to operate very close to optimal conditions for target localization. Local searches as implied by the colocalization mechanism are only found to mildly accelerate the mean search time within our model. PMID:23349772

  3. Pins and needles: minimally invasive office techniques for facial rejuvenation.

    PubMed

    Maas, Corey S; Bapna, Sumit

    2009-11-01

    The desire for minimally invasive facial rejuvenation has continued to increase from the perspective of both the patients and injectors. For successful rejuvenation, it is important to understand the anatomic changes of the aging face as well as the properties of available neuromodulators and soft tissue fillers. The injector should be knowledgeable of the advantages and disadvantages of each product. Patient selection, perhaps, plays the largest role in success, choosing patients that would truly benefit from and have reasonable expectations for minimally invasive techniques. Unsatisfactory outcomes can be limited by meticulous injection technique and well thought out treatment plans. PMID:19924599

  4. Human extravillous trophoblast invasion: intrinsic and extrinsic regulation.

    PubMed

    Menkhorst, E; Winship, A; Van Sinderen, M; Dimitriadis, E

    2016-03-01

    During the establishment of pregnancy, a human blastocyst implants into the uterine endometrium to facilitate the formation of a functional placenta. Implantation involves the blastocyst adhering to the uterine luminal epithelium before the primitive syncytiotrophoblast and subsequently specialised cells, the extravillous trophoblast (EVT), invade into the decidua in order to engraft and remodel uterine spiral arteries, creating the placental blood supply at the end of the first trimester. Defects in EVT invasion lead to abnormal placentation and thus adverse pregnancy outcomes. The local decidual environment is thought to play a key role in regulating trophoblast invasion. Here we describe the major cell types present in the decidua during the first trimester of pregnancy and review what is known about their regulation of EVT invasion. Overall, the evidence suggests that in a healthy pregnancy almost all cell types in the decidua actively promote EVT invasion and, further, that reduced EVT invasion towards the end of the first trimester is regulated, in part, by the reduced invasive capacity of EVTs shown at this time. PMID:25163485

  5. IL-33 enhances proliferation and invasiveness of decidual stromal cells by up-regulation of CCL2/CCR2 via NF-κB and ERK1/2 signaling.

    PubMed

    Hu, Wen-Ting; Li, Ming-Qing; Liu, Wei; Jin, Li-Ping; Li, Da-Jin; Zhu, Xiao-Yong

    2014-04-01

    Interleukin (IL)-33, a newly described member of the IL-1 family, has been reported to facilitate primary tumor progression and metastatic dissemination. However, its biological function on decidual stromal cells (DSCs) remains unclear. In this study, we tested the hypothesis whether IL-33 promotes proliferation and invasion of DSCs, and the possible mechanism. IL-33 and its orphan receptor ST2 was found to be co-expressed by DSCs in human first-trimester pregnancy. Addition of IL-33, enhanced the proliferation and invasion of DSCs in a dosage-dependent manner, concomitantly with increasing expression of proliferation relative gene (PCNA, survivin) and invasion relative gene (titin, MMP2). Blocking IL-33/ST2 signaling by soluble sST2 apparently abolished the stimulatory effect on the proliferation, invasiveness and related gene expression in DSCs. We also demonstrated that chemokines CCL2/CCR2 was significantly increased with IL-33 administration. Moreover, inhibition of CCL2/CCR2 activation using CCL2 neutralizing antibody or CCR2 blocker prevented IL-33-stimulated proliferation and invasiveness capacity of DSCs. Increasing phosphorylation of nuclear factor NF-κB p65 and extracellular signal-regulated kinases ERK1/2 after treatment with IL-33 was confirmed by western blotting. And the IL-33-induced CCL2/CCR2 expression was abrogated by treatment with the NF-κB inhibitor BAY 11-7082 or ERK1/2 inhibitor U0126. Finally, we showed that decreased IL-33/ST2 expression was observed in DSCs from spontaneous abortion compared with normal pregnancy at both gene and protein levels. This study provides evidence for the molecular mechanism of IL-33 in promoting proliferation and invasiveness of DSCs by up-regulation of CCL2/CCR2 via NF-κB and ERK1/2 signal pathways and thus contributes insight to the potential of IL-33 involved in successful pregnancy via inducing DSCs mitosis and invasion. PMID:24344240

  6. A Landscape Approach to Invasive Species Management.

    PubMed

    Lurgi, Miguel; Wells, Konstans; Kennedy, Malcolm; Campbell, Susan; Fordham, Damien A

    2016-01-01

    Biological invasions are not only a major threat to biodiversity, they also have major impacts on local economies and agricultural production systems. Once established, the connection of local populations into metapopulation networks facilitates dispersal at landscape scales, generating spatial dynamics that can impact the outcome of pest-management actions. Much planning goes into landscape-scale invasive species management. However, effective management requires knowledge on the interplay between metapopulation network topology and management actions. We address this knowledge gap using simulation models to explore the effectiveness of two common management strategies, applied across different extents and according to different rules for selecting target localities in metapopulations with different network topologies. These management actions are: (i) general population reduction, and (ii) reduction of an obligate resource. The reduction of an obligate resource was generally more efficient than population reduction for depleting populations at landscape scales. However, the way in which local populations are selected for management is important when the topology of the metapopulation is heterogeneous in terms of the distribution of connections among local populations. We tested these broad findings using real-world scenarios of European rabbits (Oryctolagus cuniculus) infesting agricultural landscapes in Western Australia. Although management strategies targeting central populations were more effective in simulated heterogeneous metapopulation structures, no difference was observed in real-world metapopulation structures that are highly homogeneous. In large metapopulations with high proximity and connectivity of neighbouring populations, different spatial management strategies yield similar outcomes. Directly considering spatial attributes in pest-management actions will be most important for metapopulation networks with heterogeneously distributed links. Our

  7. A Landscape Approach to Invasive Species Management

    PubMed Central

    Lurgi, Miguel; Wells, Konstans; Kennedy, Malcolm; Campbell, Susan; Fordham, Damien A.

    2016-01-01

    Biological invasions are not only a major threat to biodiversity, they also have major impacts on local economies and agricultural production systems. Once established, the connection of local populations into metapopulation networks facilitates dispersal at landscape scales, generating spatial dynamics that can impact the outcome of pest-management actions. Much planning goes into landscape-scale invasive species management. However, effective management requires knowledge on the interplay between metapopulation network topology and management actions. We address this knowledge gap using simulation models to explore the effectiveness of two common management strategies, applied across different extents and according to different rules for selecting target localities in metapopulations with different network topologies. These management actions are: (i) general population reduction, and (ii) reduction of an obligate resource. The reduction of an obligate resource was generally more efficient than population reduction for depleting populations at landscape scales. However, the way in which local populations are selected for management is important when the topology of the metapopulation is heterogeneous in terms of the distribution of connections among local populations. We tested these broad findings using real-world scenarios of European rabbits (Oryctolagus cuniculus) infesting agricultural landscapes in Western Australia. Although management strategies targeting central populations were more effective in simulated heterogeneous metapopulation structures, no difference was observed in real-world metapopulation structures that are highly homogeneous. In large metapopulations with high proximity and connectivity of neighbouring populations, different spatial management strategies yield similar outcomes. Directly considering spatial attributes in pest-management actions will be most important for metapopulation networks with heterogeneously distributed links. Our

  8. How We Think and Talk about Facilitation

    ERIC Educational Resources Information Center

    Kato, Fumitoshi

    2010-01-01

    Over the past few years, the notion of "facilitation" has been increasingly gaining attention and acceptance in Japan, especially in the context of education and training. Today, Japanese educators think and talk about facilitation, even if it is not yet clear what facilitation is. Interestingly enough, the term "facilitation" does not exist in…

  9. Diversity of pyrrolizidine alkaloids in native and invasive Senecio pterophorus (Asteraceae): implications for toxicity.

    PubMed

    Castells, Eva; Mulder, Patrick P J; Pérez-Trujillo, Míriam

    2014-12-01

    Changes in plant chemical defenses after invasion could have consequences on the invaded ecosystems by modifying the interactions between plants and herbivores and facilitating invasion success. However, no comprehensive biogeographical studies have yet determined the phenotypic levels of plant chemical defenses, as consumed by local herbivores, covering large distributional areas of a species. Senecio pterophorus is a perennial shrub native to Eastern South Africa, expanded into Western South Africa and introduced into Australia and Europe. As other Asteraceae, S. pterophorus contains pyrrolizidine alkaloids (PAs) toxic to vertebrate and invertebrate herbivores. Here we analyzed S. pterophorus PAs by LC-MS/MS on foliage sampled across its entire distributional range, including the native and all non-native areas. PA concentrations and diversity was very high: we found 57 compounds belonging to 6 distinct necine base-types, including the highly toxic 1,2-unsaturated PAs (retronecine and otonecines) and the less toxic 1,2-saturated PAs (platynecine and rosmarinecines). Plants from different origins diverged in their PA absolute and relative concentrations. Rosmarinine was the most abundant compound in Australia and South Africa, but it was nearly absent in Europe. We characterized three plant chemotypes: retrorsine-senkirkine chemotype in Eastern South Africa, rosmarinine chemotype in Australia and Western South Africa, and acetylseneciphylline chemotype in Europe. PA absolute concentrations were highest in Australia. The increased absolute and relative concentrations of retronecine PAs from Australia and Europe, respectively, indicate that S. pterophorus is potentially more toxic in the invasive range than in the native range. PMID:25269662

  10. Facilitating Self-Regulated Learning Skills and Achievement with a Strategic Content Learning Approach

    ERIC Educational Resources Information Center

    Heller, Monica L.; Marchant, Gregory J.

    2015-01-01

    Whether out of financial concerns for student retention or altruistic goals involving facilitating successful learning, efforts are being made to ensure college student success beyond chance independent study skills. Students often lack effective self-regulatory skills and study strategies necessary for success in college. With guidance through…

  11. A long-term experimental case study of the ecological effectiveness and cost effectiveness of invasive plant management in achieving conservation goals: bitou bush control in booderee national park in eastern australia.

    PubMed

    Lindenmayer, David B; Wood, Jeff; MacGregor, Christopher; Buckley, Yvonne M; Dexter, Nicholas; Fortescue, Martin; Hobbs, Richard J; Catford, Jane A

    2015-01-01

    Invasive plant management is often justified in terms of conservation goals, yet progress is rarely assessed against these broader goals, instead focussing on short-term reductions of the invader as a measure of success. Key questions commonly remain unanswered including whether invader removal reverses invader impacts and whether management itself has negative ecosystem impacts. We addressed these knowledge gaps using a seven year experimental investigation of Bitou Bush, Chrysanthemoides monilifera subsp. rotundata. Our case study took advantage of the realities of applied management interventions for Bitou Bush to assess whether it is a driver or passenger of environmental change, and quantified conservation benefits relative to management costs of different treatment regimes. Among treatments examined, spraying with herbicide followed by burning and subsequent re-spraying (spray-fire-spray) proved the most effective for reducing the number of individuals and cover of Bitou Bush. Other treatment regimes (e.g. fire followed by spraying, or two fires in succession) were less effective or even exacerbated Bitou Bush invasion. The spray-fire-spray regime did not increase susceptibility of treated areas to re-invasion by Bitou Bush or other exotic species. This regime significantly reduced plant species richness and cover, but these effects were short-lived. The spray-fire-spray regime was the most cost-effective approach to controlling a highly invasive species and facilitating restoration of native plant species richness to levels characteristic of uninvaded sites. We provide a decision tree to guide management, where recommended actions depend on the outcome of post-treatment monitoring and performance against objectives. Critical to success is avoiding partial treatments and treatment sequences that may exacerbate invasive species impacts. We also show the value of taking advantage of unplanned events, such as wildfires, to achieve management objectives at

  12. A Long-Term Experimental Case Study of the Ecological Effectiveness and Cost Effectiveness of Invasive Plant Management in Achieving Conservation Goals: Bitou Bush Control in Booderee National Park in Eastern Australia

    PubMed Central

    Lindenmayer, David B.; Wood, Jeff; MacGregor, Christopher; Buckley, Yvonne M.; Dexter, Nicholas; Fortescue, Martin; Hobbs, Richard J.; Catford, Jane A.

    2015-01-01

    Invasive plant management is often justified in terms of conservation goals, yet progress is rarely assessed against these broader goals, instead focussing on short-term reductions of the invader as a measure of success. Key questions commonly remain unanswered including whether invader removal reverses invader impacts and whether management itself has negative ecosystem impacts. We addressed these knowledge gaps using a seven year experimental investigation of Bitou Bush, Chrysanthemoides monilifera subsp. rotundata. Our case study took advantage of the realities of applied management interventions for Bitou Bush to assess whether it is a driver or passenger of environmental change, and quantified conservation benefits relative to management costs of different treatment regimes. Among treatments examined, spraying with herbicide followed by burning and subsequent re-spraying (spray-fire-spray) proved the most effective for reducing the number of individuals and cover of Bitou Bush. Other treatment regimes (e.g. fire followed by spraying, or two fires in succession) were less effective or even exacerbated Bitou Bush invasion. The spray-fire-spray regime did not increase susceptibility of treated areas to re-invasion by Bitou Bush or other exotic species. This regime significantly reduced plant species richness and cover, but these effects were short-lived. The spray-fire-spray regime was the most cost-effective approach to controlling a highly invasive species and facilitating restoration of native plant species richness to levels characteristic of uninvaded sites. We provide a decision tree to guide management, where recommended actions depend on the outcome of post-treatment monitoring and performance against objectives. Critical to success is avoiding partial treatments and treatment sequences that may exacerbate invasive species impacts. We also show the value of taking advantage of unplanned events, such as wildfires, to achieve management objectives at

  13. Facilitating diabetes self-management.

    PubMed

    Wierenga, M E; Hewitt, J B

    1994-01-01

    The purpose of this study was to enhance sensitivity to and understanding of the perceptions of persons with diabetes by analyzing these individuals' unsolicited comments on structured questionnaires. Twenty of 66 adults with non-insulin-dependent diabetes mellitus (NIDDM) who participated in a study to modify their eating habits wrote a total of 122 unsolicited comments on three different questionnaires. A systematic analysis of the content of these comments resulted in seven coding categories: personal philosophy; knowledge deficit; weight or blood sugar problems; diet, exercise, or medication problems; self-care activity; stress; and success. Further analysis resulted in a trilevel schema (survival, regulation, success) depicting how individuals learn to manage their diabetes. The problem-identification and seeking-help behaviors identified in the survival level gradually changed to learning to live with the regimen in the regulation level. Respondents whose activities were in the success level demonstrated more autonomy than persons in the other two levels. A health orientation rather than a problem orientation also was seen in the success level. Consequently, teaching strategies should be tailored to the client's level of self-care, with an emphasis on assisting them toward the success level. PMID:7851227

  14. Airway centered invasive pulmonary aspergillosis in an immunocompetent patient: case report and literature review

    PubMed Central

    Kim, Jun Ho; Lee, Hong Lyeol; Kim, Lucia; Kim, Jung Soo; Kim, Yeo Ju; Lee, Ha Young

    2016-01-01

    Invasive pulmonary aspergillosis is a major problem that occurs in severely immunocompromised patients. Airway centered invasive pulmonary aspergillosis is rare in patients with normal immunity or those without critical illness. Computed tomography (CT) is a very useful diagnostic modality, yielding characteristic imaging findings for early diagnosis of this infection in immunocompromised and immunocompetent patients. We describe the case of an immunocompetent patient with airway centered invasive aspergillosis, who was successfully treated with voriconazole. PMID:27076982

  15. Predicting future thermal habitat suitability of competing native and invasive fish species: from metabolic scope to oceanographic modelling.

    PubMed

    Marras, Stefano; Cucco, Andrea; Antognarelli, Fabio; Azzurro, Ernesto; Milazzo, Marco; Bariche, Michel; Butenschön, Momme; Kay, Susan; Di Bitetto, Massimiliano; Quattrocchi, Giovanni; Sinerchia, Matteo; Domenici, Paolo

    2015-01-01

    Global increase in sea temperatures has been suggested to facilitate the incoming and spread of tropical invaders. The increasing success of these species may be related to their higher physiological performance compared with indigenous ones. Here, we determined the effect of temperature on the aerobic metabolic scope (MS) of two herbivorous fish species that occupy a similar ecological niche in the Mediterranean Sea: the native salema (Sarpa salpa) and the invasive marbled spinefoot (Siganus rivulatus). Our results demonstrate a large difference in the optimal temperature for aerobic scope between the salema (21.8°C) and the marbled spinefoot (29.1°C), highlighting the importance of temperature in determining the energy availability and, potentially, the distribution patterns of the two species. A modelling approach based on a present-day projection and a future scenario for oceanographic conditions was used to make predictions about the thermal habitat suitability (THS, an index based on the relationship between MS and temperature) of the two species, both at the basin level (the whole Mediterranean Sea) and at the regional level (the Sicilian Channel, a key area for the inflow of invasive species from the Eastern to the Western Mediterranean Sea). For the present-day projection, our basin-scale model shows higher THS of the marbled spinefoot than the salema in the Eastern compared with the Western Mediterranean Sea. However, by 2050, the THS of the marbled spinefoot is predicted to increase throughout the whole Mediterranean Sea, causing its westward expansion. Nevertheless, the regional-scale model suggests that the future thermal conditions of Western Sicily will remain relatively unsuitable for the invasive species and could act as a barrier for its spread westward. We suggest that metabolic scope can be used as a tool to evaluate the potential invasiveness of alien species and the resilience to global warming of native species. PMID:27293680

  16. Predicting future thermal habitat suitability of competing native and invasive fish species: from metabolic scope to oceanographic modelling

    PubMed Central

    Marras, Stefano; Cucco, Andrea; Antognarelli, Fabio; Azzurro, Ernesto; Milazzo, Marco; Bariche, Michel; Butenschön, Momme; Kay, Susan; Di Bitetto, Massimiliano; Quattrocchi, Giovanni; Sinerchia, Matteo; Domenici, Paolo

    2015-01-01

    Global increase in sea temperatures has been suggested to facilitate the incoming and spread of tropical invaders. The increasing success of these species may be related to their higher physiological performance compared with indigenous ones. Here, we determined the effect of temperature on the aerobic metabolic scope (MS) of two herbivorous fish species that occupy a similar ecological niche in the Mediterranean Sea: the native salema (Sarpa salpa) and the invasive marbled spinefoot (Siganus rivulatus). Our results demonstrate a large difference in the optimal temperature for aerobic scope between the salema (21.8°C) and the marbled spinefoot (29.1°C), highlighting the importance of temperature in determining the energy availability and, potentially, the distribution patterns of the two species. A modelling approach based on a present-day projection and a future scenario for oceanographic conditions was used to make predictions about the thermal habitat suitability (THS, an index based on the relationship between MS and temperature) of the two species, both at the basin level (the whole Mediterranean Sea) and at the regional level (the Sicilian Channel, a key area for the inflow of invasive species from the Eastern to the Western Mediterranean Sea). For the present-day projection, our basin-scale model shows higher THS of the marbled spinefoot than the salema in the Eastern compared with the Western Mediterranean Sea. However, by 2050, the THS of the marbled spinefoot is predicted to increase throughout the whole Mediterranean Sea, causing its westward expansion. Nevertheless, the regional-scale model suggests that the future thermal conditions of Western Sicily will remain relatively unsuitable for the invasive species and could act as a barrier for its spread westward. We suggest that metabolic scope can be used as a tool to evaluate the potential invasiveness of alien species and the resilience to global warming of native species. PMID:27293680

  17. Count Your Eggs Before They Invade: Identifying and Quantifying Egg Clutches of Two Invasive Apple Snail Species (Pomacea)

    PubMed Central

    Kyle, Colin H.; Plantz, Allyson L.; Shelton, Therese; Burks, Romi L.

    2013-01-01

    Winning the war against invasive species requires early detection of invasions. Compared to terrestrial invaders, aquatic species often thrive undetected under water and do not garner notice until too late for early action. However, fortunately for managers, apple snails (Family Ampullariidae, Genus Pomacea) provide their own conspicuous sign of invasion in the form of vibrantly colored egg clutches. Managers can potentially use egg clutches laid in the riparian zone as a means of early detection and species identification. To facilitate such efforts, we quantified differences in characteristics (length, width, depth, mass, egg number) of field-laid clutches for the two most common invasive species of apple snail, P. canaliculata and P. maculata, in native and non-native populations. Pomacea canaliculata native and non-native populations differed noticeably only in width. Native P. maculata clutches possessed significantly greater width, mass and eggs numbers compared with native P. canaliculata. Non-native P. maculata clutches significantly exceeded all other populations in all measured characteristics. Consequently, these traits may successfully distinguish between species. Fecundity data also allowed us to develop models that accurately estimated the number of eggs per clutch for each species based on clutch dimensions. We tested one, two and three dimensional models of clutches, including rendering a clutch as either a complete ellipsoid or an ellipsoid intersected by a cylinder to represent the oviposition site. Model comparisons found the product of length and depth, with a different function for each population, best predicted egg number for both species. Comparisons of egg number to clutch volume and mass implied non-native P. canaliculata may be food limited, while non-native P. maculata appeared to produce such enormous clutches by having access to greater nutrients than the native population. With these new tools, researchers and managers can quickly

  18. Separate and combined effects of habitat-specific fish predation on the survival of invasive and native gammarids

    NASA Astrophysics Data System (ADS)

    Kotta, Jonne; Orav-Kotta, Helen; Herkül, Kristjan

    2010-10-01

    The North-American amphipod Gammarus tigrinus was observed for the first time in the northern Baltic Sea in 2003. The invasive amphipod has been particularly successful in some habitats (e.g. on pebbles) where it has become one of the most abundant gammarid species. We studied experimentally if the dominant fish Gasterosteus aculeatus preyed differentially on the exotic G. tigrinus and the native Gammarus salinus, if predation differed among habitats, and if one gammarid species facilitated predation on the other. The experiment demonstrated that (1) fish preyed more on the exotic G. tigrinus than the native G. salinus. (2) Predation did not differ among habitats. (3) Gammarus tigrinus facilitated the predation on G. salinus and this facilitation varied among habitats with significant effects on pebbles. Thus, the combined effect of habitat-specific fish predation and competition between gammarid amphipods is a possible explanation of the current range of G. tigrinus in the northern Baltic Sea. G. tigrinus seems to establish in habitats where it can significantly increase fish predation on the native gammarids.

  19. Stochastic facilitation in the brain?

    NASA Astrophysics Data System (ADS)

    Ward, Lawrence M.; Greenwood, Priscilla E.

    2016-05-01

    We describe the context for three unsolved problems of noise in the brain as well as provide some new results relevant to one of them. The problems are: are neural oscillations better described as noisy limit cycles or as noise-driven quasicycles, does noise facilitate synchronization and information transmission in the brain, and do noise-driven spatial patterns (quasipatterns) coexist with noise-driven quasicycles in the brain? We provide a few new results indicating that, in models at least, spatial quasipatterns of quasicycles can occur, and resemble patterns observed in other areas, such as predator-prey systems and chemical reactions.

  20. Digital microfluidics for spheroid-based invasion assays.

    PubMed

    Bender, Brian F; Aijian, Andrew P; Garrell, Robin L

    2016-04-21

    Cell invasion is a key process in tissue growth, wound healing, and tumor progression. Most invasion assays examine cells cultured in adherent monolayers, which fail to recapitulate the three-dimensional nuances of the tissue microenvironment. Multicellular cell spheroids have a three-dimensional (3D) morphology and mimic the intercellular interactions found in tissues in vivo, thus providing a more physiologically relevant model for studying the tissue microenvironment and processes such as cell invasion. Spheroid-based invasion assays often require tedious, manually intensive handling protocols or the use of robotic liquid handling systems, which can be expensive to acquire, operate, and maintain. Here we describe a digital microfluidic (DμF) platform that enables formation of spheroids by the hanging drop method, encapsulation of the spheroids in collagen, and the exposure of spheroids to migration-modulating agents. Collagen sol-gel solutions up to 4 mg mL(-1), which form gels with elastic moduli up to ∼50 kPa, can be manipulated on the device. In situ spheroid migration assays show that cells from human fibroblast spheroids exhibit invasion into collagen gels, which can be either enhanced or inhibited by the delivery of exogenous migration modulating agents. Exposing fibroblast spheroids to spheroid secretions from colon cancer spheroids resulted in a >100% increase in fibroblast invasion into the collagen gel, consistent with the cancer-associated fibroblast phenotype. These data show that DμF can be used to automate the liquid handling protocols for spheroid-based invasion assays and create a cell invasion model that mimics the tissue microenvironment more closely than two-dimensional culturing techniques do. A DμF platform that facilitates the creation and assaying of 3D in vitro tissue models has the potential to make automated 3D cell-based assays more accessible to researchers in the life sciences. PMID:27020962

  1. Predicting Invasive Fungal Pathogens Using Invasive Pest Assemblages: Testing Model Predictions in a Virtual World

    PubMed Central

    Paini, Dean R.; Bianchi, Felix J. J. A.; Northfield, Tobin D.; De Barro, Paul J.

    2011-01-01

    Predicting future species invasions presents significant challenges to researchers and government agencies. Simply considering the vast number of potential species that could invade an area can be insurmountable. One method, recently suggested, which can analyse large datasets of invasive species simultaneously is that of a self organising map (SOM), a form of artificial neural network which can rank species by establishment likelihood. We used this method to analyse the worldwide distribution of 486 fungal pathogens and then validated the method by creating a virtual world of invasive species in which to test the SOM. This novel validation method allowed us to test SOM's ability to rank those species that can establish above those that can't. Overall, we found the SOM highly effective, having on average, a 96–98% success rate (depending on the virtual world parameters). We also found that regions with fewer species present (i.e. 1–10 species) were more difficult for the SOM to generate an accurately ranked list, with success rates varying from 100% correct down to 0% correct. However, we were able to combine the numbers of species present in a region with clustering patterns in the SOM, to further refine confidence in lists generated from these sparsely populated regions. We then used the results from the virtual world to determine confidences for lists generated from the fungal pathogen dataset. Specifically, for lists generated for Australia and its states and territories, the reliability scores were between 84–98%. We conclude that a SOM analysis is a reliable method for analysing a large dataset of potential invasive species and could be used by biosecurity agencies around the world resulting in a better overall assessment of invasion risk. PMID:22016773

  2. Facilitation of learning: part 2.

    PubMed

    Warburton, Tyler; Houghton, Trish; Barry, Debbie

    2016-04-27

    The previous article in this series of 11, Facilitation of learning: part 1, reviewed learning theories and how they relate to clinical practice. Developing an understanding of these theories is essential for mentors and practice teachers to enable them to deliver evidence-based learning support. This is important given that effective learning support is dependent on an educator who possesses knowledge of their specialist area as well as the relevent tools and methods to support learning. The second domain of the Nursing and Midwifery Council's Standards to Support Learning and Assessment in Practice relates to the facilitation of learning. To fulfil this domain, mentors and practice teachers are required to demonstrate their ability to recognise the needs of learners and provide appropriate support to meet those needs. This article expands on some of the discussions from part 1 of this article and considers these from a practical perspective, in addition to introducing some of the tools that can be used to support learning. PMID:27191319

  3. Positive Emotion Facilitates Audiovisual Binding

    PubMed Central

    Kitamura, Miho S.; Watanabe, Katsumi; Kitagawa, Norimichi

    2016-01-01

    It has been shown that positive emotions can facilitate integrative and associative information processing in cognitive functions. The present study examined whether emotions in observers can also enhance perceptual integrative processes. We tested 125 participants in total for revealing the effects of emotional states and traits in observers on the multisensory binding between auditory and visual signals. Participants in Experiment 1 observed two identical visual disks moving toward each other, coinciding, and moving away, presented with a brief sound. We found that for participants with lower depressive tendency, induced happy moods increased the width of the temporal binding window of the sound-induced bounce percept in the stream/bounce display, while no effect was found for the participants with higher depressive tendency. In contrast, no effect of mood was observed for a simple audiovisual simultaneity discrimination task in Experiment 2. These results provide the first empirical evidence of a dependency of multisensory binding upon emotional states and traits, revealing that positive emotions can facilitate the multisensory binding processes at a perceptual level. PMID:26834585

  4. A Source Area Approach Demonstrates Moderate Predictive Ability but Pronounced Variability of Invasive Species Traits.

    PubMed

    Klonner, Günther; Fischer, Stefan; Essl, Franz; Dullinger, Stefan

    2016-01-01

    The search for traits that make alien species invasive has mostly concentrated on comparing successful invaders and different comparison groups with respect to average trait values. By contrast, little attention has been paid to trait variability among invaders. Here, we combine an analysis of trait differences between invasive and non-invasive species with a comparison of multidimensional trait variability within these two species groups. We collected data on biological and distributional traits for 1402 species of the native, non-woody vascular plant flora of Austria. We then compared the subsets of species recorded and not recorded as invasive aliens anywhere in the world, respectively, first, with respect to the sampled traits using univariate and multiple regression models; and, second, with respect to their multidimensional trait diversity by calculating functional richness and dispersion metrics. Attributes related to competitiveness (strategy type, nitrogen indicator value), habitat use (agricultural and ruderal habitats, occurrence under the montane belt), and propagule pressure (frequency) were most closely associated with invasiveness. However, even the best multiple model, including interactions, only explained a moderate fraction of the differences in invasive success. In addition, multidimensional variability in trait space was even larger among invasive than among non-invasive species. This pronounced variability suggests that invasive success has a considerable idiosyncratic component and is probably highly context specific. We conclude that basing risk assessment protocols on species trait profiles will probably face hardly reducible uncertainties. PMID:27187616

  5. A Source Area Approach Demonstrates Moderate Predictive Ability but Pronounced Variability of Invasive Species Traits

    PubMed Central

    Essl, Franz; Dullinger, Stefan

    2016-01-01

    The search for traits that make alien species invasive has mostly concentrated on comparing successful invaders and different comparison groups with respect to average trait values. By contrast, little attention has been paid to trait variability among invaders. Here, we combine an analysis of trait differences between invasive and non-invasive species with a comparison of multidimensional trait variability within these two species groups. We collected data on biological and distributional traits for 1402 species of the native, non-woody vascular plant flora of Austria. We then compared the subsets of species recorded and not recorded as invasive aliens anywhere in the world, respectively, first, with respect to the sampled traits using univariate and multiple regression models; and, second, with respect to their multidimensional trait diversity by calculating functional richness and dispersion metrics. Attributes related to competitiveness (strategy type, nitrogen indicator value), habitat use (agricultural and ruderal habitats, occurrence under the montane belt), and propagule pressure (frequency) were most closely associated with invasiveness. However, even the best multiple model, including interactions, only explained a moderate fraction of the differences in invasive success. In addition, multidimensional variability in trait space was even larger among invasive than among non-invasive species. This pronounced variability suggests that invasive success has a considerable idiosyncratic component and is probably highly context specific. We conclude that basing risk assessment protocols on species trait profiles will probably face hardly reducible uncertainties. PMID:27187616

  6. Minimally invasive parathyroid surgery

    PubMed Central

    Noureldine, Salem I.; Gooi, Zhen

    2015-01-01

    Traditionally, bilateral cervical exploration for localization of all four parathyroid glands and removal of any that are grossly enlarged has been the standard surgical treatment for primary hyperparathyroidism (PHPT). With the advances in preoperative localization studies and greater public demand for less invasive procedures, novel targeted, minimally invasive techniques to the parathyroid glands have been described and practiced over the past 2 decades. Minimally invasive parathyroidectomy (MIP) can be done either through the standard Kocher incision, a smaller midline incision, with video assistance (purely endoscopic and video-assisted techniques), or through an ectopically placed, extracervical, incision. In current practice, once PHPT is diagnosed, preoperative evaluation using high-resolution radiographic imaging to localize the offending parathyroid gland is essential if MIP is to be considered. The imaging study results suggest where the surgeon should begin the focused procedure and serve as a road map to allow tailoring of an efficient, imaging-guided dissection while eliminating the unnecessary dissection of multiple glands or a bilateral exploration. Intraoperative parathyroid hormone (IOPTH) levels may be measured during the procedure, or a gamma probe used during radioguided parathyroidectomy, to ascertain that the correct gland has been excised and that no other hyperfunctional tissue is present. MIP has many advantages over the traditional bilateral, four-gland exploration. MIP can be performed using local anesthesia, requires less operative time, results in fewer complications, and offers an improved cosmetic result and greater patient satisfaction. Additional advantages of MIP are earlier hospital discharge and decreased overall associated costs. This article aims to address the considerations for accomplishing MIP, including the role of preoperative imaging studies, intraoperative adjuncts, and surgical techniques. PMID:26425454

  7. Minimally invasive mediastinal surgery

    PubMed Central

    Melfi, Franca M. A.; Mussi, Alfredo

    2016-01-01

    In the past, mediastinal surgery was associated with the necessity of a maximum exposure, which was accomplished through various approaches. In the early 1990s, many surgical fields, including thoracic surgery, observed the development of minimally invasive techniques. These included video-assisted thoracic surgery (VATS), which confers clear advantages over an open approach, such as less trauma, short hospital stay, increased cosmetic results and preservation of lung function. However, VATS is associated with several disadvantages. For this reason, it is not routinely performed for resection of mediastinal mass lesions, especially those located in the anterior mediastinum, a tiny and remote space that contains vital structures at risk of injury. Robotic systems can overcome the limits of VATS, offering three-dimensional (3D) vision and wristed instrumentations, and are being increasingly used. With regards to thymectomy for myasthenia gravis (MG), unilateral and bilateral VATS approaches have demonstrated good long-term neurologic results with low complication rates. Nevertheless, some authors still advocate the necessity of maximum exposure, especially when considering the distribution of normal and ectopic thymic tissue. In recent studies, the robotic approach has shown to provide similar neurological outcomes when compared to transsternal and VATS approaches, and is associated with a low morbidity. Importantly, through a unilateral robotic technique, it is possible to dissect and remove at least the same amount of mediastinal fat tissue. Preliminary results on early-stage thymomatous disease indicated that minimally invasive approaches are safe and feasible, with a low rate of pleural recurrence, underlining the necessity of a “no-touch” technique. However, especially for thymomatous disease characterized by an indolent nature, further studies with long follow-up period are necessary in order to assess oncologic and neurologic results through minimally

  8. Minimally invasive mediastinal surgery.

    PubMed

    Melfi, Franca M A; Fanucchi, Olivia; Mussi, Alfredo

    2016-01-01

    In the past, mediastinal surgery was associated with the necessity of a maximum exposure, which was accomplished through various approaches. In the early 1990s, many surgical fields, including thoracic surgery, observed the development of minimally invasive techniques. These included video-assisted thoracic surgery (VATS), which confers clear advantages over an open approach, such as less trauma, short hospital stay, increased cosmetic results and preservation of lung function. However, VATS is associated with several disadvantages. For this reason, it is not routinely performed for resection of mediastinal mass lesions, especially those located in the anterior mediastinum, a tiny and remote space that contains vital structures at risk of injury. Robotic systems can overcome the limits of VATS, offering three-dimensional (3D) vision and wristed instrumentations, and are being increasingly used. With regards to thymectomy for myasthenia gravis (MG), unilateral and bilateral VATS approaches have demonstrated good long-term neurologic results with low complication rates. Nevertheless, some authors still advocate the necessity of maximum exposure, especially when considering the distribution of normal and ectopic thymic tissue. In recent studies, the robotic approach has shown to provide similar neurological outcomes when compared to transsternal and VATS approaches, and is associated with a low morbidity. Importantly, through a unilateral robotic technique, it is possible to dissect and remove at least the same amount of mediastinal fat tissue. Preliminary results on early-stage thymomatous disease indicated that minimally invasive approaches are safe and feasible, with a low rate of pleural recurrence, underlining the necessity of a "no-touch" technique. However, especially for thymomatous disease characterized by an indolent nature, further studies with long follow-up period are necessary in order to assess oncologic and neurologic results through minimally invasive

  9. Getting the right traits: reproductive and dispersal characteristics predict the invasiveness of herbaceous plant species.

    PubMed

    Moravcová, Lenka; Pyšek, Petr; Jarošík, Vojtěch; Pergl, Jan

    2015-01-01

    To better understand the effect of species traits on plant invasion, we collected comparative data on 20 reproductive and dispersal traits of 93 herbaceous alien species in the Czech Republic, central Europe, introduced after 1500 A. D. We explain plant invasion success, expressed by two measures: invasiveness, i.e. whether the species is naturalized but non-invasive, or invasive; and dominance in plant communities expressed as the mean cover in vegetation plots. We also tested how important reproductive and dispersal traits are in models including other characteristics generally known to predict invasion outcome, such as plant height, life history and residence time. By using regression/classification trees we show that the biological traits affect invasion success at all life stages, from reproduction (seed production) to dispersal (propagule properties), and the ability to compete with resident species (height). By including species traits information not usually available in multispecies analyses, we provide evidence that traits do play important role in determining the outcome of invasion and can be used to distinguish between alien species that reach the final stage of the invasion process and dominate the local communities from those that do not. No effect of taxonomy ascertained in regression and classification trees indicates that the role of traits in invasiveness should be assessed primarily at the species level. PMID:25906399

  10. Population genetic dynamics of an invasion reconstructed from the sediment egg bank.

    PubMed

    Möst, Markus; Oexle, Sarah; Marková, Silvia; Aidukaite, Dalia; Baumgartner, Livia; Stich, Hans-Bernd; Wessels, Martin; Martin-Creuzburg, Dominik; Spaak, Piet

    2015-08-01

    Biological invasions are a global issue with far-reaching consequences for single species, communities and whole ecosystems. Our understanding of modes and mechanisms of biological invasions requires knowledge of the genetic processes associated with successful invasions. In many instances, this information is particularly difficult to obtain as the initial phases of the invasion process often pass unnoticed and we rely on inferences from contemporary population genetic data. Here, we combined historic information with the genetic analysis of resting eggs to reconstruct the invasion of Daphnia pulicaria into Lower Lake Constance (LLC) in the 1970s from the resting egg bank in the sediments. We identified the invader as 'European D. pulicaria' originating from meso- and eutrophic lowland lakes and ponds in Central Europe. The founding population was characterized by extremely low genetic variation in the resting egg bank that increased considerably over time. Furthermore, strong evidence for selfing and/or biparental inbreeding was found during the initial phase of the invasion, followed by a drop of selfing rate to low levels in subsequent decades. Moreover, the increase in genetic variation was most pronounced during early stages of the invasion, suggesting additional introductions during this period. Our study highlights that genetic data covering the entire invasion process from its beginning can be crucial to accurately reconstruct the invasion history of a species. We show that propagule banks can preserve such information enabling the study of population genetic dynamics and sources of genetic variation in successful invasive populations. PMID:26122166

  11. Getting the Right Traits: Reproductive and Dispersal Characteristics Predict the Invasiveness of Herbaceous Plant Species

    PubMed Central

    Moravcová, Lenka; Pyšek, Petr; Pergl, Jan

    2015-01-01

    To better understand the effect of species traits on plant invasion, we collected comparative data on 20 reproductive and dispersal traits of 93 herbaceous alien species in the Czech Republic, central Europe, introduced after 1500 A. D. We explain plant invasion success, expressed by two measures: invasiveness, i.e. whether the species is naturalized but non-invasive, or invasive; and dominance in plant communities expressed as the mean cover in vegetation plots. We also tested how important reproductive and dispersal traits are in models including other characteristics generally known to predict invasion outcome, such as plant height, life history and residence time. By using regression/classification trees we show that the biological traits affect invasion success at all life stages, from reproduction (seed production) to dispersal (propagule properties), and the ability to compete with resident species (height). By including species traits information not usually available in multispecies analyses, we provide evidence that traits do play important role in determining the outcome of invasion and can be used to distinguish between alien species that reach the final stage of the invasion process and dominate the local communities from those that do not. No effect of taxonomy ascertained in regression and classification trees indicates that the role of traits in invasiveness should be assessed primarily at the species level. PMID:25906399

  12. Invasive hemodynamic monitoring.

    PubMed

    Magder, Sheldon

    2015-01-01

    Although invasive hemodynamic monitoring requires considerable skill, studies have shown a striking lack of knowledge of the measurements obtained with the pulmonary artery catheter (PAC). This article reviews monitoring using a PAC. Issues addressed include basic physiology that determines cardiac output and blood pressure; methodology in the measurement of data obtained from a PAC; use of the PAC in making a diagnosis and for patient management, with emphasis on a responsive approach to management; and uses of the PAC that are not indications by themselves for placing the catheter, but can provide useful information when a PAC is in place. PMID:25435479

  13. Minimally Invasive Parathyroidectomy

    PubMed Central

    Starker, Lee F.; Fonseca, Annabelle L.; Carling, Tobias; Udelsman, Robert

    2011-01-01

    Minimally invasive parathyroidectomy (MIP) is an operative approach for the treatment of primary hyperparathyroidism (pHPT). Currently, routine use of improved preoperative localization studies, cervical block anesthesia in the conscious patient, and intraoperative parathyroid hormone analyses aid in guiding surgical therapy. MIP requires less surgical dissection causing decreased trauma to tissues, can be performed safely in the ambulatory setting, and is at least as effective as standard cervical exploration. This paper reviews advances in preoperative localization, anesthetic techniques, and intraoperative management of patients undergoing MIP for the treatment of pHPT. PMID:21747851

  14. Spinal cord injury affects I-wave facilitation in human motor cortex.

    PubMed

    Nardone, Raffaele; Höller, Yvonne; Bathke, Arne C; Orioli, Andrea; Schwenker, Kerstin; Frey, Vanessa; Golaszewski, Stefan; Brigo, Francesco; Trinka, Eugen

    2015-07-01

    Transcranial magnetic stimulation (TMS) is a useful non-invasive approach for studying cortical physiology. To further clarify the mechanisms of cortical reorganization after spinal cord injury (SCI), we used a non-invasive paired TMS protocol for the investigation of the corticospinal I-waves, the so-called I-wave facilitation, in eight patients with cervical SCI. We found that the pattern of I-wave facilitation significantly differs between SCI patients with normal and abnormal central motor conduction (CMCT), and healthy controls. The group with normal CMCT showed increased I-wave facilitation, while the group with abnormal CMCT showed lower I-wave facilitation compared to a control group. The facilitatory I-wave interaction occurs at the level of the motor cortex, and the mechanisms responsible for the production of I-waves are under control of GABA-related inhibition. Therefore, the findings of our small sample preliminary study provide further physiological evidence of increased motor cortical excitability in patients with preserved corticospinal projections. This is possibly due to decreased GABAergic intracortical inhibition. The excitability of networks producing short-interval intracortical facilitation could increase after SCI as a mechanism to enhance activation of residual corticospinal tract pathways and thus compensate for the impaired ability of the motor cortex to generate appropriate voluntary movements. Finally, the I-wave facilitation technique could be used in clinical neurorehabilitation as an additional method of assessing and monitoring function in SCI. PMID:26151771

  15. Comparing the Invasibility of Experimental “Reefs” with Field Observations of Natural Reefs and Artificial Structures

    PubMed Central

    Dafforn, Katherine A.; Glasby, Tim M.; Johnston, Emma L.

    2012-01-01

    Natural systems are increasingly being modified by the addition of artificial habitats which may facilitate invasion. Where invaders are able to disperse from artificial habitats, their impact may spread to surrounding natural communities and therefore it is important to investigate potential factors that reduce or enhance invasibility. We surveyed the distribution of non-indigenous and native invertebrates and algae between artificial habitats and natural reefs in a marine subtidal system. We also deployed sandstone plates as experimental ‘reefs’ and manipulated the orientation, starting assemblage and degree of shading. Invertebrates (non-indigenous and native) appeared to be responding to similar environmental factors (e.g. orientation) and occupied most space on artificial structures and to a lesser extent reef walls. Non-indigenous invertebrates are less successful than native invertebrates on horizontal reefs despite functional similarities. Manipulative experiments revealed that even when non-indigenous invertebrates invade vertical “reefs”, they are unlikely to gain a foothold and never exceed covers of native invertebrates (regardless of space availability). Community ecology suggests that invertebrates will dominate reef walls and algae horizontal reefs due to functional differences, however our surveys revealed that native algae dominate both vertical and horizontal reefs in shallow estuarine systems. Few non-indigenous algae were sampled in the study, however where invasive algal species are present in a system, they may present a threat to reef communities. Our findings suggest that non-indigenous species are less successful at occupying space on reef compared to artificial structures, and manipulations of biotic and abiotic conditions (primarily orientation and to a lesser extent biotic resistance) on experimental “reefs” explained a large portion of this variation, however they could not fully explain the magnitude of differences. PMID

  16. Teaching for Successful Intelligence Raises School Achievement.

    ERIC Educational Resources Information Center

    Sternberg, Robert J.; Torff, Bruce; Grigorenko, Elena

    1998-01-01

    A "successful intelligence" intervention improved school achievement for a group of 225 ethnically diverse third-graders, both on performance assessments measuring analytical, creative, and practical achievements and on conventional multiple-choice memory assessments. Teaching for triarchic thinking facilitates factual recall, because learning…

  17. Understanding Successful Sandwich Placements: A Bourdieusian Approach

    ERIC Educational Resources Information Center

    Clark, Martyn; Zukas, Miriam

    2016-01-01

    Sandwich placements and other integrated work and study schemes are increasingly advocated as a key means by which universities can promote students' employability. However, there is little understanding of how successful placements work in terms of facilitating learning and development. Drawing on three longitudinal case studies of students who…

  18. Large-scale aerial images capture details of invasive plant populations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Satellite and aerial remote sensing have been successfully used to measure invasive weed infestations over very large areas, but have limited resolution. Ground-based methods have provided detailed measurements of invasive weeds, but can measure only limited areas. Here we test a novel approach th...

  19. Within plant interspecific competition does not limit the highly invasive thrips, Frankliniella occidentalis in Florida

    Technology Transfer Automated Retrieval System (TEKTRAN)

    1. Competitive superiority is often cited as the main reason for the success of an invasive species. Although invaded ecosystems are often examined, few have studied areas in which an invasive species has failed to invade. 2. The western flower thrips, Frankliniella occidentalis, is a damaging pest ...

  20. Limitations to postfire seedling establishment: the role of seeding technology, water availability, and invasive plant abundance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Seeding rangeland following wildfire is a central tool managers use to stabilize soils and inhibit the spread of invasive plants. Rates of successful seeding on arid rangeland, however, are low. The objective of this study was to determine the degree to which water availability, invasive plant abund...

  1. Minimally Invasive Approach of a Retrocaval Ureter

    PubMed Central

    Pinheiro, Hugo; Ferronha, Frederico; Morales, Jorge; Campos Pinheiro, Luís

    2016-01-01

    The retrocaval ureter is a rare congenital entity, classically managed with open pyeloplasty techniques. The experience obtained with the laparoscopic approach of other more frequent causes of ureteropelvic junction (UPJ) obstruction has opened the method for the minimally invasive approach of the retrocaval ureter. In our paper, we describe a clinical case of a right retrocaval ureter managed successfully with laparoscopic dismembered pyeloplasty. The main standpoints of the procedure are described. Our results were similar to others published by other urologic centers, which demonstrates the safety and feasibility of the procedure for this condition.

  2. The Influence of Facilitator and Facilitation Characteristics on Participants' Ratings of Stepfamily Education

    ERIC Educational Resources Information Center

    Higginbotham, Brian J.; Myler, Cory

    2010-01-01

    We examine the relative importance of facilitator and facilitation characteristics on participant ratings of a stepfamily education program. Data from 48 facilitators and 598 participants suggest that quality facilitation is more meaningful to participants than whether facilitators have comparable demographic characteristics or life experiences.…

  3. How Batterer Intervention Programs Work: Participant and Facilitator Accounts of Processes of Change

    ERIC Educational Resources Information Center

    Silvergleid, Courtenay S.; Mankowski, Eric S.

    2006-01-01

    Understanding what facilitates change in men who perpetrate domestic violence can aid the development of more effective batterer intervention programs (BIPs). To identify and describe key change processes, in-depth interviews were conducted with nine successful BIP completers and with 10 intervention group facilitators. The accounts described a…

  4. Malignant cancer and invasive placentation

    PubMed Central

    D'Souza, Alaric W.; Wagner, Günter P.

    2014-01-01

    Cancer metastasis is an invasive process that involves the transplantation of cells into new environments. Since human placentation is also invasive, hypotheses about a relationship between invasive placentation in eutherian mammals and metastasis have been proposed. The relationship between metastatic cancer and invasive placentation is usually presented in terms of antagonistic pleiotropy. According to this hypothesis, evolution of invasive placentation also established the mechanisms for cancer metastasis. Here, in contrast, we argue that the secondary evolution of less invasive placentation in some mammalian lineages may have resulted in positive pleiotropic effects on cancer survival by lowering malignancy rates. These positive pleiotropic effects would manifest themselves as resistance to cancer cell invasion. To provide a preliminary test of this proposal, we re-analyze data from Priester and Mantel (Occurrence of tumors in domestic animals. Data from 12 United States and Canadian colleges of veterinary medicine. J Natl Cancer Inst 1971;47:1333-44) about malignancy rates in cows, horses, cats and dogs. From our analysis we found that equines and bovines, animals with less invasive placentation, have lower rates of metastatic cancer than felines and canines in skin and glandular epithelial cancers as well as connective tissue sarcomas. We conclude that a link between type of placentation and species-specific malignancy rates is more likely related to derived mechanisms that suppress invasion rather than different degrees of fetal placental aggressiveness. PMID:25324490

  5. The economic impact of minimally invasive total knee arthroplasty.

    PubMed

    Coon, Thomas M

    2006-07-01

    The goals of minimally invasive surgery (MIS) total knee arthroplasty (TKA) are to minimize surgical trauma, minimize blood loss, and maximize the effect of analgesia. Assuming these surgical procedures are successful and rigid fixation is achieved, the result, in theory, should be shorter hospital stays and successful, early, aggressive rehabilitation at reduced cost relative to standard TKA surgical techniques. In this article, I address the economic benefits of applying MIS TKA surgical techniques compared with standard TKA surgical techniques. PMID:16927653

  6. Assessing stakeholder perspectives on invasive plants to inform risk analysis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Conservation and land management decisions are often based primarily on natural science, but could be more successful if human influences were effectively integrated into decision-making. This is especially true for efforts to manage invasive plants, whose arrival is usually the product of delibera...

  7. Facilitating submetering implementation. Final report

    SciTech Connect

    Bowers, M.A.

    1996-05-01

    Residential submetering is the measurement and billing of electric use in individual apartments in master-metered buildings. In master-metered building situations, residents do not bear electricity costs in proportion to consumption levels. As a result, studies have confirmed that residents in master-metered buildings tend to consume more electricity than residents with individual apartment metering, and have established electrical submetering as an effective energy conservation measure. The New York State Energy Research & Development Authority (NYSERDA) has commissioned a project called Facilitating Submetering Implementation to identify and analyze barriers to the implementation of residential electrical submetering in New York and to formulate recommendations that would facilitate the removal of these barriers, streamlining the process. Experienced professionals in the technical, legal, regulatory, analytical, financial, and other aspects of submetering were retained to interview key interested parties and conduct public forums. This and other data were then analyzed to ascertain the barriers to submetering and develop recommendations designed to reduce or eliminate these barriers. The key barriers to submetering implementation were found to be the Public Service Commission (PSC) requirement for a vote of a majority of shareholders (for coops and condos) and the high initial cost that cannot easily be recouped by owners of both rental and shareholder-owned buildings. The key recommendations are to repeal the voting requirement, maintain the utility incentives, adopt a uniform dispute resolution mechanism, and increase awareness through an Ad-hoc Submetering Committee and supporting educational materials. Other funding sources not fully available can also be made available with regulatory agency support.

  8. [Minimally Invasive Treatment of Esophageal Benign Diseases].

    PubMed

    Inoue, Haruhiro

    2016-07-01

    As a minimally invasive treatment of esophageal achalasia per-oral endoscopic myotomy( POEM) was developed in 2008. More than 1,100 cases of achalasia-related diseases received POEM. Success rate of the procedure was more than 95%(Eckerdt score improvement 3 points and more). No serious( Clavian-Dindo classification III b and more) complication was experienced. These results suggest that POEM becomes a standard minimally invasive treatment for achalasia-related diseases. As an off-shoot of POEM submucosal tumor removal through submucosal tunnel (per-oral endoscopic tumor resection:POET) was developed and safely performed. Best indication of POET is less than 5 cm esophageal leiomyoma. A novel endoscopic treatment of gastroesophageal reflux disease (GERD) was developed. Anti-reflux mucosectomy( ARMS) is nearly circumferential mucosal reduction of gastric cardia mucosa. ARMS is performed in 56 consecutive cases of refractory GERD. No major complications were encountered and excellent clinical results. Best indication of ARMS is a refractory GERD without long sliding hernia. Longest follow-up case is more than 10 years. Minimally invasive treatments for esophageal benign diseases are currently performed by therapeutic endoscopy. PMID:27440038

  9. In vitro Cell Migration and Invasion Assays

    PubMed Central

    Justus, Calvin R.; Leffler, Nancy; Ruiz-Echevarria, Maria; Yang, Li V.

    2014-01-01

    Migration is a key property of live cells and critical for normal development, immune response, and disease processes such as cancer metastasis and inflammation. Methods to examine cell migration are very useful and important for a wide range of biomedical research such as cancer biology, immunology, vascular biology, cell biology and developmental biology. Here we use tumor cell migration and invasion as an example and describe two related assays to illustrate the commonly used, easily accessible methods to measure these processes. The first method is the cell culture wound closure assay in which a scratch is generated on a confluent cell monolayer. The speed of wound closure and cell migration can be quantified by taking snapshot pictures with a regular inverted microscope at several time intervals. More detailed cell migratory behavior can be documented using the time-lapse microscopy system. The second method described in this paper is the transwell cell migration and invasion assay that measures the capacity of cell motility and invasiveness toward a chemo-attractant gradient. It is our goal to describe these methods in a highly accessible manner so that the procedures can be successfully performed in research laboratories even just with basic cell biology setup. PMID:24962652

  10. Facilitating Alzheimer disease research recruitment.

    PubMed

    Grill, Joshua D; Galvin, James E

    2014-01-01

    Alzheimer disease (AD) research faces challenges to successful enrollment, especially to clinical trials and biomarker studies. Failure to recruit the planned number of participants in a timely manner threatens the internal validity and success of clinical research, raising concerns about external validity and generalizability of results, and possibly leading to disparities in disease treatment. Methods to improve recruitment exist, but require varying levels of staff effort and financial resources, and evidence of effectiveness is often lacking or inconsistent. In this review, we summarize some of the available methods to improve AD research recruitment, the available literature to support or refute these strategies, and some of the experiences at the authors' AD Research Centers. We discuss the use of community-based participatory research principles and participant registries as a means to enhance research enrollment and increase diversity of research samples. PMID:24322484

  11. Clarifying debates in invasion biology: a survey of invasion biologists.

    PubMed

    Young, Ashley M; Larson, Brendon M H

    2011-10-01

    Invasion biology is a relatively new field, so there are ongoing debates about foundational issues regarding terminology and assessment of the causes and consequences of invasive species. These debates largely reflect differing views about the extent to which invasion biologists should advocate on behalf of native species. We surveyed reviewers of the journal Biological Invasions to obtain a better sense of how invasion biologists evaluate several foundational issues. We received 422 replies, which represented a very good response rate for an online survey of 42.5% of those contacted. Responses to several debates in the field were distributed bimodally, but respondents consistently indicated that contemporary biological invasions are unprecedented. Even still, this was not seen as justification for exaggerated language (hyperbole). In contrast to prevalent claims in the literature, only 27.3% of respondents ranked invasive species as the first or second greatest threat to biodiversity. The responses also highlighted the interaction of invasive species with other threats and the role of human activity in their spread. Finally, the respondents agreed that they need to be both more objective and better at communicating their results so that those results can be effectively integrated into management. PMID:21757195

  12. ITER risk workshop facilitator guide

    SciTech Connect

    Medina, Patricia

    2009-01-01

    The goal of planning risk management is to make everyone involved in a program aware that risk should be a consideration in the design, development, and fielding of a system. Risk planning is a tool to assess and mitigate events that might adversely impact the program. Therefore, risk management increases the probability/likelihood of program success and can help to avoid program crisis management and improve problem solving by managing risk early in the acquisition cycle.

  13. Non-Invasive Imaging of Neuroanatomical Structures and Neural Activation with High-Resolution MRI

    PubMed Central

    Herberholz, Jens; Mishra, Subrata H.; Uma, Divya; Germann, Markus W.; Edwards, Donald H.; Potter, Kimberlee

    2011-01-01

    Several years ago, manganese-enhanced magnetic resonance imaging (MEMRI) was introduced as a new powerful tool to image active brain areas and to identify neural connections in living, non-human animals. Primarily restricted to studies in rodents and later adapted for bird species, MEMRI has recently been discovered as a useful technique for neuroimaging of invertebrate animals. Using crayfish as a model system, we highlight the advantages of MEMRI over conventional techniques for imaging of small nervous systems. MEMRI can be applied to image invertebrate nervous systems at relatively high spatial resolution, and permits identification of stimulus-evoked neural activation non-invasively. Since the selection of specific imaging parameters is critical for successful in vivo micro-imaging, we present an overview of different experimental conditions that are best suited for invertebrates. We also compare the effects of hardware and software specifications on image quality, and provide detailed descriptions of the steps necessary to prepare animals for successful imaging sessions. Careful consideration of hardware, software, experiments, and specimen preparation will promote a better understanding of this novel technique and facilitate future MEMRI studies in other laboratories. PMID:21503138

  14. Minimally invasive radio-guided surgery for primary hyperparathyroidism: From preoperative to intraoperative localization imaging.

    PubMed

    Rubello, D; Kapse, N; Grassetto, G; Massaro, A; Al-Nahhas, A

    2010-12-01

    The introduction and successful implementation of minimally invasive radio-guided parathyroidectomy (MIRP) has revolutionized the surgical approach to remove parathyroid adenomas. A prerequisite for such success is an accurate localization of the offending adenoma. To achieve this goal, a multimodality approach is commonly employed using a combination of anatomical and functional imaging. Of the anatomical cross-sectional techniques, ultrasonography is the most widely available but is operator-dependent and has reduced sensitivity, specially in the presence of thyroid nodules. Similarly, computed tomography and magnetic resonance imaging have low sensitivities but provide value in detecting retrotracheal, retro-oesophageal and mediastinal adenomas. Functional imaging with ⁹⁹(m)Tc-Sestamibi is currently the most vital imaging procedure in this respect with variable protocols including dual-phase and dual isotope imaging. The sensitivity and specificity can improve by acquiring in single photon emission tomography (SPECT) mode and using co-registration with low dose CT to provide anatomical data (SPECT/CT). The current recommended approach is the combination of functional imaging with ⁹⁹(m)Tc-Sestamibi and high-resolution ultrasound (US), supplemented with intraoperative gamma probe in certain cases and quick persurgical measurement of parathyroid hormone. This review aims to explore the utility of various imaging modalities, alone and in combination, in detecting parathyroid adenoma and facilitating the current approach of MIRP. PMID:20846640

  15. A Quartet of Success Stories: How to Make Inclusion Work.

    ERIC Educational Resources Information Center

    Farlow, Leslie

    1996-01-01

    As the profiles of four mentally handicapped teenagers show, students with severe disabilities can benefit from being included in subject-area classes. To facilitate inclusion, teachers can allow peers to facilitate learning, prime students to be successful participants, give students valued roles, utilize existing expertise, and adapt the…

  16. Invasion and Management of Agricultural Alien Insects in China.

    PubMed

    Wan, Fang-Hao; Yang, Nian-Wan

    2016-01-01

    China is the world's fourth-largest country in terms of landmass. Its highly diverse biogeography presents opportunities for many invasive alien insects. However, physical and climate barriers sometimes prevent locally occurring species from spreading. China has 560 confirmed invasive alien species; 125 are insect pests, and 92 of these damage the agricultural ecosystem. The estimated annual economic loss due to alien invasive species is more than $18.9 billion. The most harmful invasive insects exhibit some common characteristics, such as high reproduction, competitive dominance, and high tolerance, and benefit from mutualist facilitation interactions. Regional cropping system structure adjustments have resulted in mono-agricultural ecosystems in cotton and other staple crops, providing opportunities for monophagous insect pests. Furthermore, human dietary shifts to fruits and vegetables and smallholder-based farming systems result in highly diverse agricultural ecosystems, which provide resource opportunities for polyphagous insects. Multiple cropping and widespread use of greenhouses provide continuous food and winter habitats for insect pests, greatly extending their geographic range. The current management system consists of early-warning, monitoring, eradication, and spread blocking technologies. This review provides valuable new synthetic information on integrated management practices based mainly on biological control for a number of invasive species. We encourage farmers and extension workers to be more involved in training and further research for novel protection methods that takes into consideration end users' needs. PMID:26527302

  17. Technologies and Techniques for Supporting Facilitated Video

    ERIC Educational Resources Information Center

    Linnell, Natalie

    2011-01-01

    Worldwide, demand for education of all kinds is increasing beyond the capacity to provide it. One approach that shows potential for addressing this demand is facilitated video. In facilitated video, an educator is recorded teaching, and that video is sent to a remote site where it is shown to students by a facilitator who creates interaction…

  18. Facilitated IEP Meetings: An Emerging Practice

    ERIC Educational Resources Information Center

    Consortium for Appropriate Dispute Resolution in Special Education (CADRE), 2004

    2004-01-01

    To help special education planning teams reach agreements, several State Education Agencies (SEAs) provide the option of facilitated Individualized Education Program (IEP) meetings. The use of externally facilitated IEP meetings is growing nationally. When relationships between parents and schools are strained, facilitated meetings may be…

  19. Evaluation of the Facilitated Communication Pilot

    ERIC Educational Resources Information Center

    Cooper-Martin, Elizabeth

    2014-01-01

    The Office of Special Education and Student Services asked the Office of Shared Accountability to evaluate the "Facilitated Communication Pilot." In facilitated communication (FC), people with communication impairments express themselves by typing with the aid of a communication partner, called a facilitator, who provides physical (and…

  20. The Teacher and Town Planner as Facilitator.

    ERIC Educational Resources Information Center

    Peel, Deborah

    2000-01-01

    Discussion of theories of facilitation in teaching focuses on citizen participation and the role of the facilitator in town planning. Highlights include hierarchies of learning; student-centered learning; facilitating community participation; information technology skills and interpersonal skills; and a rationale for participation. (LRW)