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Sample records for invasion decreases diversity

  1. 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

  2. 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

  3. SPARC Promotes Cell Invasion In Vivo by Decreasing Type IV Collagen Levels in the Basement Membrane

    PubMed Central

    Morrissey, Meghan A.; Jayadev, Ranjay; Miley, Ginger R.; Blebea, Catherine A.; Chi, Qiuyi; Ihara, Shinji; Sherwood, David R.

    2016-01-01

    Overexpression of SPARC, a collagen-binding glycoprotein, is strongly associated with tumor invasion through extracellular matrix in many aggressive cancers. SPARC regulates numerous cellular processes including integrin-mediated cell adhesion, cell signaling pathways, and extracellular matrix assembly; however, the mechanism by which SPARC promotes cell invasion in vivo remains unclear. A main obstacle in understanding SPARC function has been the difficulty of visualizing and experimentally examining the dynamic interactions between invasive cells, extracellular matrix and SPARC in native tissue environments. Using the model of anchor cell invasion through the basement membrane (BM) extracellular matrix in Caenorhabditis elegans, we find that SPARC overexpression is highly pro-invasive and rescues BM transmigration in mutants with defects in diverse aspects of invasion, including cell polarity, invadopodia formation, and matrix metalloproteinase expression. By examining BM assembly, we find that overexpression of SPARC specifically decreases levels of BM type IV collagen, a crucial structural BM component. Reduction of type IV collagen mimicked SPARC overexpression and was sufficient to promote invasion. Tissue-specific overexpression and photobleaching experiments revealed that SPARC acts extracellularly to inhibit collagen incorporation into BM. By reducing endogenous SPARC, we also found that SPARC functions normally to traffic collagen from its site of synthesis to tissues that do not express collagen. We propose that a surplus of SPARC disrupts extracellular collagen trafficking and reduces BM collagen incorporation, thus weakening the BM barrier and dramatically enhancing its ability to be breached by invasive cells. PMID:26926673

  4. SPARC Promotes Cell Invasion In Vivo by Decreasing Type IV Collagen Levels in the Basement Membrane.

    PubMed

    Morrissey, Meghan A; Jayadev, Ranjay; Miley, Ginger R; Blebea, Catherine A; Chi, Qiuyi; Ihara, Shinji; Sherwood, David R

    2016-02-01

    Overexpression of SPARC, a collagen-binding glycoprotein, is strongly associated with tumor invasion through extracellular matrix in many aggressive cancers. SPARC regulates numerous cellular processes including integrin-mediated cell adhesion, cell signaling pathways, and extracellular matrix assembly; however, the mechanism by which SPARC promotes cell invasion in vivo remains unclear. A main obstacle in understanding SPARC function has been the difficulty of visualizing and experimentally examining the dynamic interactions between invasive cells, extracellular matrix and SPARC in native tissue environments. Using the model of anchor cell invasion through the basement membrane (BM) extracellular matrix in Caenorhabditis elegans, we find that SPARC overexpression is highly pro-invasive and rescues BM transmigration in mutants with defects in diverse aspects of invasion, including cell polarity, invadopodia formation, and matrix metalloproteinase expression. By examining BM assembly, we find that overexpression of SPARC specifically decreases levels of BM type IV collagen, a crucial structural BM component. Reduction of type IV collagen mimicked SPARC overexpression and was sufficient to promote invasion. Tissue-specific overexpression and photobleaching experiments revealed that SPARC acts extracellularly to inhibit collagen incorporation into BM. By reducing endogenous SPARC, we also found that SPARC functions normally to traffic collagen from its site of synthesis to tissues that do not express collagen. We propose that a surplus of SPARC disrupts extracellular collagen trafficking and reduces BM collagen incorporation, thus weakening the BM barrier and dramatically enhancing its ability to be breached by invasive cells. PMID:26926673

  5. Habitat fragmentation, tree diversity, and plant invasion interact to structure forest caterpillar communities.

    PubMed

    Stireman, John O; Devlin, Hilary; Doyle, Annie L

    2014-09-01

    Habitat fragmentation and invasive species are two of the most prominent threats to terrestrial ecosystems. Few studies have examined how these factors interact to influence the diversity of natural communities, particularly primary consumers. Here, we examined the effects of forest fragmentation and invasion of exotic honeysuckle (Lonicera maackii, Caprifoliaceae) on the abundance and diversity of the dominant forest herbivores: woody plant-feeding Lepidoptera. We systematically surveyed understory caterpillars along transects in 19 forest fragments over multiple years in southwestern Ohio and evaluated how fragment area, isolation, tree diversity, invasion by honeysuckle and interactions among these factors influence species richness, diversity and abundance. We found strong seasonal variation in caterpillar communities, which responded differently to fragmentation and invasion. Abundance and richness increased with fragment area, but these effects were mitigated by high levels of honeysuckle, tree diversity, landscape forest cover, and large recent changes in area. Honeysuckle infestation was generally associated with decreased caterpillar abundance and diversity, but these effects were strongly dependent on other fragment traits. Effects of honeysuckle on abundance were moderated when fragment area, landscape forest cover and tree diversity were high. In contrast, negative effects of honeysuckle invasion on caterpillar diversity were most pronounced in fragments with high tree diversity and large recent increases in area. Our results illustrate the complex interdependencies of habitat fragmentation, plant diversity and plant invasion in their effects on primary consumers and emphasize the need to consider these processes in concert to understand the consequences of anthropogenic habitat change for biodiversity. PMID:25015121

  6. Decreased TUSC3 Promotes Pancreatic Cancer Proliferation, Invasion and Metastasis

    PubMed Central

    Fan, Xiaoqiang; Zhang, Xiu; Shen, Jie; Zhao, Haibin; Yu, Xuetao; Chen, Yong’an; Zhuang, Zhuonan; Deng, Xiaolong; Feng, Hua; Wang, Yunfei; Peng, Long

    2016-01-01

    Pancreatic cancer is an aggressive disease with dismal prognosis. It is of paramount importance to understand the underlying etiological mechanisms and identify novel, consistent, and easy-to-apply prognostic factors for precision therapy. TUSC3 (tumor suppressor candidate 3) was identified as a potential tumor suppressor gene and previous study showed TUSC3 is decreased in pancreatic cancer at mRNA level, but its putative tumor suppressor function remains to be verified. In this study, TUSC3 expression was found to be suppressed both at mRNA and protein levels in cell line models as well as in clinical samples; decreased TUSC3 expression was associated with higher pathological TNM staging and poorer outcome. In three pairs of cell lines with different NF-κB activity, TUSC3 expression was found to be reversely correlated with NF-κB activity. TUSC3-silenced pancreatic cancer cell line exhibited enhanced potential of proliferation, migration and invasion. In an orthotopic implanted mice model, TUSC3 silenced cells exhibited more aggressive phenotype with more liver metastasis. In conclusion, the current study shows that decreased immunological TUSC3 staining is a factor prognostic of poor survival in pancreatic cancer patients and decreased TUSC3 promotes pancreatic cancer cell proliferation, invasion and metastasis. The reverse correlation between NF-κB activity and TUSC3 expression may suggest a novel regulation pattern for this molecule. PMID:26871953

  7. Role of ATF5 in the invasive potential of diverse human cancer cell lines.

    PubMed

    Nukuda, Akihiro; Endoh, Hiroki; Yasuda, Motoaki; Mizutani, Takeomi; Kawabata, Kazushige; Haga, Hisashi

    2016-06-01

    Activating transcription factor 5 (ATF5) is a member of the ATF/cAMP response element-binding protein family. Our research group recently revealed that ATF5 expression increases the invasiveness of human lung carcinoma cells. However, the effects of ATF5 on the invasive potential of other cancer cells lines remain unclear. Therefore, in this study, we investigated the role of ATF5 in the invasive activity of diverse human cancer cell lines. Invasiveness was assessed using Matrigel invasion assays. ATF5 knockdown resulted in decreased invasiveness in seven of eight cancer cell lines tested. These results suggest that ATF5 promotes invasiveness in several cancer cell lines. Furthermore, the roles of ATF5 in the invasiveness were evaluated in three-dimensional (3D) culture conditions. In 3D collagen gel, HT-1080 and MDA-MB-231 cells exhibited high invasiveness, with spindle morphology and high invasion speed. In both cell lines, knockdown of ATF5 resulted in rounded morphology and decreased invasion speed. Next, we showed that ATF5 induced integrin-α2 and integrin-β1 expression and that the depletion of integrin-α2 or integrin-β1 resulted in round morphology and decreased invasion speed. Our results suggest that ATF5 promotes invasion by inducing the expression of integrin-α2 and integrin-β1 in several human cancer cell lines. PMID:27125458

  8. Tree Diversity Limits the Impact of an Invasive Forest Pest.

    PubMed

    Guyot, Virginie; Castagneyrol, Bastien; Vialatte, Aude; Deconchat, Marc; Selvi, Federico; Bussotti, Filippo; Jactel, Hervé

    2015-01-01

    The impact of invasive herbivore species may be lower in more diverse plant communities due to mechanisms of associational resistance. According to the "resource concentration hypothesis" the amount and accessibility of host plants is reduced in diverse plant communities, thus limiting the exploitation of resources by consumers. In addition, the "natural enemy hypothesis" suggests that richer plant assemblages provide natural enemies with more complementary resources and habitats, thus promoting top down regulation of herbivores. We tested these two hypotheses by comparing crown damage by the invasive Asian chestnut gall wasp (Dryocosmus kuriphilus) on chestnut trees (Castanea sativa) in pure and mixed stands in Italy. We estimated the defoliation on 70 chestnut trees in 15 mature stands sampled in the same region along a gradient of tree species richness ranging from one species (chestnut monocultures) to four species (mixtures of chestnut and three broadleaved species). Chestnut defoliation was significantly lower in stands with higher tree diversity. Damage on individual chestnut trees decreased with increasing height of neighboring, heterospecific trees. These results suggest that conservation biological control method based on tree species mixtures might help to reduce the impact of the Asian chestnut gall. PMID:26360881

  9. Tree Diversity Limits the Impact of an Invasive Forest Pest

    PubMed Central

    Guyot, Virginie; Castagneyrol, Bastien; Vialatte, Aude; Deconchat, Marc; Selvi, Federico; Bussotti, Filippo; Jactel, Hervé

    2015-01-01

    The impact of invasive herbivore species may be lower in more diverse plant communities due to mechanisms of associational resistance. According to the “resource concentration hypothesis” the amount and accessibility of host plants is reduced in diverse plant communities, thus limiting the exploitation of resources by consumers. In addition, the “natural enemy hypothesis” suggests that richer plant assemblages provide natural enemies with more complementary resources and habitats, thus promoting top down regulation of herbivores. We tested these two hypotheses by comparing crown damage by the invasive Asian chestnut gall wasp (Dryocosmus kuriphilus) on chestnut trees (Castanea sativa) in pure and mixed stands in Italy. We estimated the defoliation on 70 chestnut trees in 15 mature stands sampled in the same region along a gradient of tree species richness ranging from one species (chestnut monocultures) to four species (mixtures of chestnut and three broadleaved species). Chestnut defoliation was significantly lower in stands with higher tree diversity. Damage on individual chestnut trees decreased with increasing height of neighboring, heterospecific trees. These results suggest that conservation biological control method based on tree species mixtures might help to reduce the impact of the Asian chestnut gall. PMID:26360881

  10. Origin matters: diversity affects the performance of alien invasive species but not of native species.

    PubMed

    Sun, Yan; Müller-Schärer, Heinz; Maron, John L; Schaffner, Urs

    2015-06-01

    At local scales, it has often been found that invasibility decreases with increasing resident plant diversity. However, whether resident community diversity similarly resists invasion by alien versus native species is seldom studied. We examined this issue by invading constructed native plant assemblages that varied in species and functional richness with invasive alien or native Asteraceae species. Assemblages were also invaded with spotted knapweed, Centaurea stoebe, a native European aster that has been previously used in diversity-invasibility experiments in North America. We also conducted a field survey to explore the generality of the patterns generated from our experimental study. Both experimental and observational work revealed that increasing diversity reduced the performance of alien but not native invaders. Centaurea stoebe invading its native community performed poorly regardless of resident diversity, whereas in a parallel, previously published study conducted in North America, C. stoebe easily invaded low-diversity but not high-diversity assemblages. Our results suggest that diversity is an attribute of resident communities that makes them more or less susceptible to invasion by novel invasive alien but not native plant species. PMID:25996858

  11. Curvilinear Effects of Invasive Plants on Plant Diversity: Plant Community Invaded by Sphagneticola trilobata

    PubMed Central

    Zhai, De-Li; Chen, Si-Chong; Si, Chun-Can; Huang, Ping; Wang, Rui-Ping; Zhong, Qiong-Xin; Du, Dao-Lin

    2014-01-01

    The effects of invasive plants on the species diversity of plant communities are controversial, showing either a positive or negative linear relationship. Based on community data collected from forty 5 m×5 m plots invaded by Sphagneticola trilobata in eight cities across Hainan Island, China, we found S. trilobata decreased plant community diversity once its cover was beyond 10%. We demonstrated that the effects of invasive/native plants on the plant diversity of communities invaded by S. trilobata were curvilinear. These effects, which showed peaks under different degrees of vegetation cover, appeared not only for S. trilobata and all invasive plants, but also for all native plants. Invasive plants primarily had negative effects on plant diversity when they became abundant at a much lower cover level (less than 35%), compared with the native plants (over 60%). Thus, it is necessary to distinguish a range for assessing the effects of plants, especially invasive plants. Our results also confirmed that the invasion intensity of invasive alien plants increased with the intensity of local economic development. We highlight and further discuss the critical importance of curvilinear effects of biological invasion to provide ideas regarding the conservation of local biodiversity and the management of invasive plants. PMID:25426856

  12. 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

  13. Severe plant invasions can increase mycorrhizal fungal abundance and diversity

    PubMed Central

    Lekberg, Ylva; Gibbons, Sean M; Rosendahl, Søren; Ramsey, Philip W

    2013-01-01

    Invasions by non-native plants can alter ecosystem functions and reduce native plant diversity, but relatively little is known about their effect on belowground microbial communities. We show that invasions by knapweed (Centaurea stoebe) and leafy spurge (Euphorbia esula, hereafter spurge)—but not cheatgrass (Bromus tectorum)—support a higher abundance and diversity of symbiotic arbuscular mycorrhizal fungi (AMF) than multi-species native plant communities. The higher AMF richness associated with knapweed and spurge is unlikely due to a co-invasion by AMF, because a separate sampling showed that individual native forbs hosted a similar AMF abundance and richness as exotic forbs. Native grasses associated with fewer AMF taxa, which could explain the reduced AMF richness in native, grass-dominated communities. The three invasive plant species harbored distinct AMF communities, and analyses of co-occurring native and invasive plants indicate that differences were partly driven by the invasive plants and were not the result of pre-invasion conditions. Our results suggest that invasions by mycotrophic plants that replace poorer hosts can increase AMF abundance and richness. The high AMF richness in monodominant plant invasions also indicates that the proposed positive relationship between above and belowground diversity is not always strong. Finally, the disparate responses among exotic plants and consistent results between grasses and forbs suggest that AMF respond more to plant functional group than plant provenance. PMID:23486251

  14. Sampling and Complementarity Effects of Plant Diversity on Resource Use Increases the Invasion Resistance of Communities

    PubMed Central

    Zhu, Dan H.; Wang, Ping; Zhang, Wei Z.; Yuan, Yue; Li, Bin; Wang, Jiang

    2015-01-01

    Background Although plant diversity is postulated to resist invasion, studies have not provided consistent results, most of which were ascribed to the influences of other covariate environmental factors. Methodology/Principal Findings To explore the mechanisms by which plant diversity influences community invasibility, an experiment was conducted involving grassland sites varying in their species richness (one, two, four, eight, and sixteen species). Light interception efficiency and soil resources (total N, total P, and water content) were measured. The number of species, biomass, and the number of seedlings of the invading species decreased significantly with species richness. The presence of Patrinia scabiosaefolia Fisch. ex Trev. and Mosla dianthera (Buch.-Ham. ex Roxburgh) Maxim. significantly increased the resistance of the communities to invasion. A structural equation model showed that the richness of planted species had no direct and significant effect on invasion. Light interception efficiency had a negative effect on the invasion whereas soil water content had a positive effect. In monocultures, Antenoron filiforme (Thunb.) Rob. et Vaut. showed the highest light interception efficiency and P. scabiosaefolia recorded the lowest soil water content. With increased planted-species richness, a greater percentage of pots showed light use efficiency higher than that of A. filiforme and a lower soil water content than that in P. scabiosaefolia. Conclusions/Significance The results of this study suggest that plant diversity confers resistance to invasion, which is mainly ascribed to the sampling effect of particular species and the complementarity effect among species on resources use. PMID:26556713

  15. Evolution of Invasion in a Diverse Set of Fusobacterium Species

    PubMed Central

    Manson McGuire, Abigail; Cochrane, Kyla; Griggs, Allison D.; Haas, Brian J.; Abeel, Thomas; Zeng, Qiandong; Nice, Justin B.; MacDonald, Hanlon; Birren, Bruce W.; Berger, Bryan W.; Allen-Vercoe, Emma

    2014-01-01

    ABSTRACT The diverse Fusobacterium genus contains species implicated in multiple clinical pathologies, including periodontal disease, preterm birth, and colorectal cancer. The lack of genetic tools for manipulating these organisms leaves us with little understanding of the genes responsible for adherence to and invasion of host cells. Actively invading Fusobacterium species can enter host cells independently, whereas passively invading species need additional factors, such as compromise of mucosal integrity or coinfection with other microbes. We applied whole-genome sequencing and comparative analysis to study the evolution of active and passive invasion strategies and to infer factors associated with active forms of host cell invasion. The evolution of active invasion appears to have followed an adaptive radiation in which two of the three fusobacterial lineages acquired new genes and underwent expansions of ancestral genes that enable active forms of host cell invasion. Compared to passive invaders, active invaders have much larger genomes, encode FadA-related adhesins, and possess twice as many genes encoding membrane-related proteins, including a large expansion of surface-associated proteins containing the MORN2 domain of unknown function. We predict a role for proteins containing MORN2 domains in adhesion and active invasion. In the largest and most comprehensive comparison of sequenced Fusobacterium species to date, we have generated a testable model for the molecular pathogenesis of Fusobacterium infection and illuminate new therapeutic or diagnostic strategies. PMID:25370491

  16. Invasive lionfish use a diversity of habitats in Florida

    USGS Publications Warehouse

    Schofield, Pamela J.; Akins, Lad; Gregoire-Lucente, Denise R.; Pawlitz, Rachel J.

    2014-01-01

    Two species of lionfish (Pterois volitans and Pterois miles) are the first marine fishes known to invade and establish self-sustaining populations along the eastern seaboard of the United States. First documented off the coast of Florida in 1985, lionfish are now found along the Atlantic coast of the United States as well as in the Caribbean Sea and Gulf of Mexico. Although long-term effects of this invasion are not yet fully known, there is early evidence that lionfish are negatively impacting native marine life. The lionfish invasion raises questions about which types of habitat the species will occupy in its newly invaded ecosystem. In their native range, lionfish are found primarily on coral reefs but sometimes are found in other habitats such as seagrasses and mangroves. This fact sheet documents the diversity of habitat types in which invasive lionfish have been reported within Florida’s coastal waters, based on lionfish sightings recorded in the U.S. Geological Survey Nonindigenous Aquatic Species database (USGS-NAS).

  17. Furin inhibition results in absent or decreased invasiveness and tumorigenicity of human cancer cells

    PubMed Central

    Bassi, Daniel E.; Lopez De Cicco, Ricardo; Mahloogi, Haleh; Zucker, Stanley; Thomas, Gary; Klein-Szanto, Andres J. P.

    2001-01-01

    Pro-protein convertases such as furin are expressed in many human tumor lines and primary tumors. Furin processes stromelysin-3, membrane type 1 matrix metalloproteinase (MMPs) involved in tumor cell invasiveness, as well as growth factors such as transforming growth factor β1. Evaluation of furin expression in head and neck squamous cell carcinoma (HNSCC) cells exhibiting different invasive ability showed that furin overexpression correlated with their respective invasiveness. The use of a selective furin inhibitor, alpha 1-PDX (PDX) was studied in three furin-expressing invasive HNSCC cell lines. The effects of PDX transfection were evaluated in vivo and in vitro to determine changes in the malignant phenotype. Transfection of HNSCC cell lines with PDX resulted in significant decrease or absence of tumorigenicity after s.c. inoculation into severe combined immunodeficient mice. Likewise, in vitro invasiveness was reduced ≈50%. The in vivo invasion assay using tracheal xenotransplants showed even more drastic reductions of the invasive ability of PDX-transfected cells (up to an 80% decrease). PDX-transfected cells did not invade or penetrated less into the tracheal wall tissues than their vector alone-transfected counterparts. In addition, the former cells showed a remarkable decrease in MMP-2 processing and activity. After PDX transfection the cells were less efficient in processing the tumor progression-associated furin substrates transforming growth factor β1 and pro-membrane type 1-MMP. These findings indicate that furin inhibition is a feasible approach to attenuate and even abolish certain critical attributes of the advanced malignant phenotype. Thus, furin should be considered as a promising target for cancer therapy. PMID:11517338

  18. Biodiversity loss decreases parasite diversity: theory and patterns

    USGS Publications Warehouse

    Lafferty, Kevin D.

    2012-01-01

    Past models have suggested host–parasite coextinction could lead to linear, or concave down relationships between free-living species richness and parasite richness. I explored several models for the relationship between parasite richness and biodiversity loss. Life cycle complexity, low generality of parasites and sensitivity of hosts reduced the robustness of parasite species to the loss of free-living species diversity. Food-web complexity and the ordering of extinctions altered these relationships in unpredictable ways. Each disassembly of a food web resulted in a unique relationship between parasite richness and the richness of free-living species, because the extinction trajectory of parasites was sensitive to the order of extinctions of free-living species. However, the average of many disassemblies tended to approximate an analytical model. Parasites of specialist hosts and hosts higher on food chains were more likely to go extinct in food-web models. Furthermore, correlated extinctions between hosts and parasites (e.g. if parasites share a host with a specialist predator) led to steeper declines in parasite richness with biodiversity loss. In empirical food webs with random removals of free-living species, the relationship between free-living species richness and parasite richness was, on average, quasi-linear, suggesting biodiversity loss reduces parasite diversity more than previously thought.

  19. Less can be more: loss of MHC functional diversity can reflect adaptation to novel conditions during fish invasions

    PubMed Central

    Monzón-Argüello, Catalina; Garcia de Leaniz, Carlos; Gajardo, Gonzalo; Consuegra, Sofia

    2013-01-01

    The ability of invasive species to adapt to novel conditions depends on population size and environmental mismatch, but also on genetic variation. Away from their native range, invasive species confronted with novel selective pressures may display different levels of neutral versus functional genetic variation. However, the majority of invasion studies have only examined genetic variation at neutral markers, which may reveal little about how invaders adapt to novel environments. Salmonids are good model systems to examine adaptation to novel pressures because they have been translocated all over the world and represent major threats to freshwater biodiversity in the Southern Hemisphere, where they have become invasive. We examined patterns of genetic differentiation at seven putatively neutral (microsatellites) loci and one immune-related major histocompatibility complex (MHC class II-β) locus among introduced rainbow trout living in captivity (farmed) or under natural conditions (naturalized) in Chilean Patagonia. A significant positive association was found between differentiation at neutral and functional markers, highlighting the role of neutral evolutionary forces in shaping genetic variation at immune-related genes in salmonids. However, functional (MHC) genetic diversity (but not microsatellite diversity) decreased with time spent in the wild since introduction, suggesting that there was selection against alleles associated with captive rearing of donor populations that do not provide an advantage in the wild. Thus, although high genetic diversity may initially enhance fitness in translocated populations, it does not necessarily reflect invasion success, as adaptation to novel conditions may result in rapid loss of functional MHC diversity. PMID:24223274

  20. In situ clinical evidence that zinc levels are decreased in breast invasive ductal carcinoma

    PubMed Central

    Zou, Jing; Franklin, Renty B.

    2016-01-01

    Purpose Altered zinc levels in malignant cells versus their normal cells have important implications in the development and progression of several cancers. Prostate, pancreatic, and hepatocellular carcinomas exhibit consistent marked zinc decrease in situ in the malignant cells, and other cancers (such as kidney, lung, and thyroid) also exhibit decreased tissue zinc levels. However, zinc levels are increased in breast cancer tissue compared to breast normal tissue, and the contemporary dominant view is that zinc is increased in invasive ductal carcinoma. This has important implications regarding the role and effects of zinc in breast malignancy compared to other cancers, which caused us to initiate this study to either confirm or challenge the contemporary view of an increased zinc level in the invasive ductal malignant cells. Methods We employed dithizone staining of breast tissue sections and tissue cores to determine the relative in situ cellular zinc levels specifically in the invasive ductal malignant cells as compared to normal ductal epithelium. This approach had not been employed in any of the reported breast studies. Results The results revealed that the zinc levels are consistently and markedly decreased in the ductal malignant cells as compared with higher prominent zinc levels in the normal ductal epithelium. Decreased zinc is evident in Grade 1 well-differentiated malignancy and in Grade 2 and Grade 3 carcinomas. Among the twenty-five cancer cases in this study, none exhibited increased zinc in the invasive ductal carcinoma compared to the zinc level in the normal ductal epithelium. Conclusions The decreased zinc levels in breast invasive ductal carcinoma is consistent with prostate, pancreatic, and liver carcinomas in which the decrease in zinc is a required event in the development of malignancy to prevent cytotoxicity that would result from the higher zinc levels in the normal cells. This new understanding requires a redirection in elucidating the

  1. Targeting SIM2-s decreases glioma cell invasion through mesenchymal--epithelial transition.

    PubMed

    Su, Yuhang; Wang, Juntao; Zhang, Xiaodan; Shen, Jie; Deng, Lin; Liu, Qinglin; Li, Gang

    2014-11-01

    Glioma is a common primary intracranial carcinoma with high incidence, recurrence, and motility. Single minded homolog 2-short form (SIM2-s), a member of basic helix-loop-helix (bHLH) family, is reported to be expressed in glioma and might play a role in the invasion. In the present study, we investigated the importance of SIM2-s in glioma invasion and further explored the potential mechanisms. We showed that targeting SIM2-s by interference technology could decrease cell adhesion to fibronectin, induce cell aggregation and cytoskeletal changes. Furthermore, we showed that targeting SIM2-s increased the expression of epithelial markers and decreased the expression of mesenchymal markers, that is mesenchymal-epithelial transition (MET). Targeting SIM2-s decreased self-renewal of glioma stem cells by tumor sphere formation assay. Taken together, our results indicated that MET is involved in the inhibition of glioma invasion by targeting SIM2-s, and SIM2-s may be a new gene target. PMID:24909296

  2. Decreased expression of ADAMTS-1 in human breast tumors stimulates migration and invasion

    PubMed Central

    2013-01-01

    Background ADAMTS-1 (a disintegrin and metalloprotease with thrombospondin motifs) is a member of the ADAMTS family of metalloproteases. Here, we investigated mRNA and protein levels of ADAMTS-1 in normal and neoplastic tissues using qPCR, immunohistochemistry and immunoblot analyses, and we addressed the role of ADAMTS-1 in regulating migration, invasion and invadopodia formation in breast tumor cell lines. Results In a series of primary breast tumors, we observed variable levels of ADAMTS-1 mRNA expression but lower levels of ADAMTS-1 protein expression in human breast cancers as compared to normal tissue, with a striking decrease observed in high-malignancy cases (triple-negative for estrogen, progesterone and Her-2). This result prompted us to analyze the effect of ADAMTS-1 knockdown in breast cancer cells in vitro. MDA-MB-231 cells with depleted ADAMTS-1 expression demonstrated increased migration, invasion and invadopodia formation. The regulatory mechanisms underlying the effects of ADAMTS-1 may be related to VEGF, a growth factor involved in migration and invasion. MDA-MB-231 cells with depleted ADAMTS-1 showed increased VEGF concentrations in conditioned medium capable of inducing human endothelial cells (HUVEC) tubulogenesis. Furthermore, expression of the VEGF receptor (VEGFR2) was increased in MDA-MB-231 cells as compared to MCF7 cells. To further determine the relationship between ADAMTS-1 and VEGF regulating breast cancer cells, MDA-MB-231 cells with reduced expression of ADAMTS-1 were pretreated with a function-blocking antibody against VEGF and then tested in migration and invasion assays; both were partially rescued to control levels. Conclusions ADAMTS-1 expression was decreased in human breast tumors, and ADAMTS-1 knockdown stimulated migration, invasion and invadopodia formation in breast cancer cells in vitro. Therefore, this series of experiments suggests that VEGF is involved in the effects mediated by ADAMTS-1 in breast cancer cells. PMID

  3. Microbial diversity determines the invasion of soil by a bacterial pathogen

    PubMed Central

    van Elsas, Jan Dirk; Chiurazzi, Mario; Mallon, Cyrus A.; Elhottovā, Dana; Krištůfek, Václav; Salles, Joana Falcão

    2012-01-01

    Natural ecosystems show variable resistance to invasion by alien species, and this resistance can relate to the species diversity in the system. In soil, microorganisms are key components that determine life support functions, but the functional redundancy in the microbiota of most soils has long been thought to overwhelm microbial diversity–function relationships. We here show an inverse relationship between soil microbial diversity and survival of the invading species Escherichia coli O157:H7, assessed by using the marked derivative strain T. The invader's fate in soil was determined in the presence of (i) differentially constructed culturable bacterial communities, and (ii) microbial communities established using a dilution-to-extinction approach. Both approaches revealed a negative correlation between the diversity of the soil microbiota and survival of the invader. The relationship could be explained by a decrease in the competitive ability of the invader in species-rich vs. species-poor bacterial communities, reflected in the amount of resources used and the rate of their consumption. Soil microbial diversity is a key factor that controls the extent to which bacterial invaders can establish. PMID:22232669

  4. Minimal genetic diversity in the facultatively outcrossing perennial pepperweed (Lepidium latifolium) invasion

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Perennial pepperweed (Lepidium latifolium L.) is a Eurasian plant species that is invasive in North America. The invasion often forms large, dense monocultural stands. We investigated the genetic diversity along transects in dense populations in the western USA using Amplified Fragment Length Polymo...

  5. Inhibition of arachidonic acid metabolism decreases tumor cell invasion and matrix metalloproteinase expression.

    PubMed

    Koontongkaew, Sittichai; Monthanapisut, Paopanga; Saensuk, Theeranuch

    2010-11-01

    Head and neck cancers are known to synthesize arachidonic acid metabolites. Interfering with arachidonic acid metabolism may inhibit growth and invasiveness of cancer cells. In this study we investigate effects of sulindac (the non-selective COX inhibitor), aspirin (the irreversible, preferential COX-1 inhibitor), NS-398 (the selective COX-2 inhibitor), NDGA (nordihydroguaiaretic acid, the selective LOX inhibitor) and ETYA (5,8,11,14-eicosatetraynoic acid, the COX and LOX inhibitor) on cell viability, MMP-2 and MMP-9 activities, and in vitro invasion of cancer cells derived from primary and metastatic head and neck, and colon cancers. The inhibitors of COX and/or LOX could inhibit cell proliferation, MMP activity and invasion in head and neck and colon cancer cells. However, the inhibitory effect was obviously observed in colon cancer cells. Inhibition of arachidonic acid metabolism caused a decrease in cancer cell motility, which partially explained by the inhibition of MMPs. Therefore, COX and LOX pathways play important roles in head and neck cancer cell growth. PMID:20654727

  6. Fire and grazing impacts on plant diversity and alien plant invasions in the southern Sierra Nevada

    USGS Publications Warehouse

    Keeley, J.E.; Lubin, D.; Fotheringham, C.J.

    2003-01-01

    the vegetation mosaic in this region places them in proximity to chaparral. The speed at which alien propagules reach a burned site and the speed at which the shrublands return to their former closed-canopy condition determine alien invasion. Frequent burning of this vegetation alters the balance in favor of alien invasion. In the higher-elevation coniferous forests, species diversity was a function of fire severity and time since fire. High-intensity fires create gaps that decrease canopy coverage and increase light levels and nutrients for an ephemeral successional flora. Few species have persistent seed banks, so the time since fire is an important determinant of colonization success. There was a highly significant interaction between fire severity and time since fire for understory cover, species richness, and alien richness and cover. Understory was sparse in the first year after fire, particularly in low-severity burns, and increased substantially several years after fire, particularly on high-severity burns. Both fire severity and time since fire affected alien species richness and dominance. Coniferous forests had about one-third as many alien species as the foothill oak savannas, and fewer than half of the species were shared between these communities. Unburned coniferous forests were largely free of alien species, whereas some burned sites had a significant alien presence, which presents a challenge for fire restoration of these forests.

  7. Diversity of dynamics and morphologies of invasive solid tumors

    NASA Astrophysics Data System (ADS)

    Jiao, Yang; Torquato, Salvatore

    2012-03-01

    Complex tumor-host interactions can significantly affect the growth dynamics and morphologies of progressing neoplasms. The growth of a confined solid tumor induces mechanical pressure and deformation of the surrounding microenvironment, which in turn influences tumor growth. In this paper, we generalize a recently developed cellular automaton model for invasive tumor growth in heterogeneous microenvironments [Y. Jiao and S. Torquato, PLoS Comput. Biol. 7, e1002314 (2011)] by incorporating the effects of pressure. Specifically, we explicitly model the pressure exerted on the growing tumor due to the deformation of the microenvironment and its effect on the local tumor-host interface instability. Both noninvasive-proliferative growth and invasive growth with individual cells that detach themselves from the primary tumor and migrate into the surrounding microenvironment are investigated. We find that while noninvasive tumors growing in "soft" homogeneous microenvironments develop almost isotropic shapes, both high pressure and host heterogeneity can strongly enhance malignant behavior, leading to finger-like protrusions of the tumor surface. Moreover, we show that individual invasive cells of an invasive tumor degrade the local extracellular matrix at the tumor-host interface, which diminishes the fingering growth of the primary tumor. The implications of our results for cancer diagnosis, prognosis and therapy are discussed.

  8. Cranial diameter pulsations measured by non-invasive ultrasound decrease with tilt

    NASA Technical Reports Server (NTRS)

    Ueno, Toshiaki; Ballard, Richard E.; Macias, Brandon R.; Yost, William T.; Hargens, Alan R.

    2003-01-01

    INTRODUCTION: Intracranial pressure (ICP) may play a significant role in physiological responses to microgravity by contributing to the nausea associated with microgravity exposure. However, effects of altered gravity on ICP in astronauts have not been investigated, primarily due to the invasiveness of currently available techniques. We have developed an ultrasonic device that monitors changes in cranial diameter pulsation non-invasively so that we can evaluate ICP dynamics in astronauts during spaceflight. This study was designed to demonstrate the feasibility of our ultrasound technique under the physiological condition in which ICP dynamics are changed due to altered gravitational force. METHODS: Six healthy volunteers were placed at 60 degrees head-up, 30 degrees headup, supine, and 15 degrees head-down positions for 3 min at each angle. We measured arterial blood pressure (ABP) with a finger pressure cuff, and cranial diameter pulsation with a pulsed phase lock loop device (PPLL). RESULTS: Analysis of covariance demonstrated that amplitudes of cranial diameter pulsations were significantly altered with the angle of tilt (p < 0.001). The 95% confidence interval for linear regression coefficients of the cranial diameter pulsation amplitudes with tilt angle was 0.862 to 0.968. However, ABP amplitudes did not show this relationship. DISCUSSION: Our noninvasive ultrasonic technique reveals that the amplitude of cranial diameter pulsation decreases as a function of tilt angle, suggesting that ICP pulsation follows the same relationship. It is demonstrated that the PPLL device has a sufficient sensitivity to detect changes non-invasively in ICP pulsation caused by altered gravity.

  9. Anomalous droughts, not invasion, decrease persistence of native fishes in a desert river.

    PubMed

    Ruhí, Albert; Holmes, Elizabeth E; Rinne, John N; Sabo, John L

    2015-04-01

    Changing climate extremes and invasion by non-native species are two of the most prominent threats to native faunas. Predicting the relationships between global change and native faunas requires a quantitative toolkit that effectively links the timing and magnitude of extreme events to variation in species abundances. Here, we examine how discharge anomalies--unexpected floods and droughts--determine covariation in abundance of native and non-native fish species in a highly variable desert river in Arizona. We quantified stochastic variation in discharge using Fourier analyses on >15,000 daily observations. We subsequently coupled maximum annual spectral anomalies with a 15-year time series of fish abundances (1994-2008), using Multivariate Autoregressive State-Space (MARSS) models. Abiotic drivers (discharge anomalies) were paramount in determining long-term fish abundances, whereas biotic drivers (species interactions) played only a secondary role. As predicted, anomalous droughts reduced the abundances of native species, while floods increased them. However, in contrast to previous studies, we observed that the non-native assemblage was surprisingly unresponsive to extreme events. Biological trait analyses showed that functional uniqueness was higher in native than in non-native fishes. We also found that discharge anomalies influenced diversity patterns at the meta-community level, with nestedness increasing after anomalous droughts due to the differential impairment of native species. Overall, our results advance the notion that discharge variation is key in determining community trajectories in the long term, predicting the persistence of native fauna even in the face of invasion. We suggest this variation, rather than biotic interactions, may commonly underlie covariation between native and non-native faunas, especially in highly variable environments. If droughts become increasingly severe due to climate change, and floods increasingly muted due to

  10. Breaking down the silos to decrease internal diversions and patient flow delays.

    PubMed

    Driscoll, Molly; Tobis, Kristen; Gurka, David; Serafin, Frederick; Carlson, Elizabeth

    2015-01-01

    Hospitals strive to admit patients to the units where caregiver competencies align with the patient's condition. When the hospital's census peaks, internal diversions and the associated risks increase, which are intensified when silos exist, as segregated care negatively impacts collaboration and patient safety. In this study, a 600+-bed academic, tertiary care specialty hospital experienced an increase in internal diversions. Within the neuroscience service line, emergent neuroscience transfers from outside hospitals had been declined or internally diverted because of capacity limitations. Formalized processes for improving collaboration between health care providers related to capacity issues were required to decrease internal diversions and improve patient flow and patient safety. A pilot project was conducted on neuroscience units during a process improvement initiative. A hospital-wide internal diversion plan was developed, identifying primary and secondary placement options for all patients requiring hospitalization to support patient flow and patient safety. Forecasting tools were developed to provide units' leadership with current information on expected admissions. Daily capacity huddles were instituted to increase collaboration between patient care units. The interventions trialed during the pilot decreased internal diversions and improved patient flow. The improved collaboration resulted in an 80% decrease in declinations of emergent intensive care unit transfers from outside hospitals due to capacity limitations and a 50% decrease in the number of these patients being internally diverted to alternate intensive care units. The interventions implemented minimized internal diversions and improved patient flow. The transparency of the patient placement process led to an increased collaboration between all participants. PMID:25474675

  11. The role of propagule pressure, genetic diversity and microsite availability for Senecio vernalis invasion.

    PubMed

    Erfmeier, Alexandra; Hantsch, Lydia; Bruelheide, Helge

    2013-01-01

    Genetic diversity is supposed to support the colonization success of expanding species, in particular in situations where microsite availability is constrained. Addressing the role of genetic diversity in plant invasion experimentally requires its manipulation independent of propagule pressure. To assess the relative importance of these components for the invasion of Senecio vernalis, we created propagule mixtures of four levels of genotype diversity by combining seeds across remote populations, across proximate populations, within single populations and within seed families. In a first container experiment with constant Festuca rupicola density as matrix, genotype diversity was crossed with three levels of seed density. In a second experiment, we tested for effects of establishment limitation and genotype diversity by manipulating Festuca densities. Increasing genetic diversity had no effects on abundance and biomass of S. vernalis but positively affected the proportion of large individuals to small individuals. Mixtures composed from proximate populations had a significantly higher proportion of large individuals than mixtures composed from within seed families only. High propagule pressure increased emergence and establishment of S. vernalis but had no effect on individual growth performance. Establishment was favoured in containers with Festuca, but performance of surviving seedlings was higher in open soil treatments. For S. vernalis invasion, we found a shift in driving factors from density dependence to effects of genetic diversity across life stages. While initial abundance was mostly linked to the amount of seed input, genetic diversity, in contrast, affected later stages of colonization probably via sampling effects and seemed to contribute to filtering the genotypes that finally grew up. In consequence, when disentangling the mechanistic relationships of genetic diversity, seed density and microsite limitation in colonization of invasive plants, a clear

  12. The Role of Propagule Pressure, Genetic Diversity and Microsite Availability for Senecio vernalis Invasion

    PubMed Central

    Erfmeier, Alexandra; Hantsch, Lydia; Bruelheide, Helge

    2013-01-01

    Genetic diversity is supposed to support the colonization success of expanding species, in particular in situations where microsite availability is constrained. Addressing the role of genetic diversity in plant invasion experimentally requires its manipulation independent of propagule pressure. To assess the relative importance of these components for the invasion of Senecio vernalis, we created propagule mixtures of four levels of genotype diversity by combining seeds across remote populations, across proximate populations, within single populations and within seed families. In a first container experiment with constant Festuca rupicola density as matrix, genotype diversity was crossed with three levels of seed density. In a second experiment, we tested for effects of establishment limitation and genotype diversity by manipulating Festuca densities. Increasing genetic diversity had no effects on abundance and biomass of S. vernalis but positively affected the proportion of large individuals to small individuals. Mixtures composed from proximate populations had a significantly higher proportion of large individuals than mixtures composed from within seed families only. High propagule pressure increased emergence and establishment of S. vernalis but had no effect on individual growth performance. Establishment was favoured in containers with Festuca, but performance of surviving seedlings was higher in open soil treatments. For S. vernalis invasion, we found a shift in driving factors from density dependence to effects of genetic diversity across life stages. While initial abundance was mostly linked to the amount of seed input, genetic diversity, in contrast, affected later stages of colonization probably via sampling effects and seemed to contribute to filtering the genotypes that finally grew up. In consequence, when disentangling the mechanistic relationships of genetic diversity, seed density and microsite limitation in colonization of invasive plants, a clear

  13. Disruption of Foraging by a Dominant Invasive Species to Decrease Its Competitive Ability

    PubMed Central

    Westermann, Fabian Ludwig; Suckling, David Maxwell; Lester, Philip John

    2014-01-01

    Invasive species are a major threat to biodiversity when dominant within their newly established habitat. The globally distributed Argentine ant Linepithema humile has been reported to break the trade-off between interference and exploitative competition, achieve high population densities, and overpower nests of many endemic ant species. We have used the sensitivity of the Argentine ant to the synthetic trail pheromone (Z)-9-hexadecanal to investigate species interactions for the first time. We predicted that disrupting Argentine ant trail following behaviour would reduce their competitive ability and create an opportunity for three other resident species to increase their foraging success. Argentine ant success in the control was reduced with increasing pheromone concentration, as predicted, but interactions varied among competing resident species. These behavioural variations provide an explanation for observed differences in foraging success of the competing resident species and how much each of these individual competitors can increase their foraging if the competitive ability of the dominant invader is decreased. The mechanism for the observed increase in resource acquisition of resident species appears to be a decrease in aggressive behaviour displayed by the Argentine ant, which may create an opportunity for other resident species to forage more successfully. Our demonstration of species interactions with trail pheromone disruption is the first known case of reduced dominance under a pheromone treatment in ants. PMID:24594633

  14. Gene Flow and Maintenance of Genetic Diversity in Invasive Mosquitofish (Gambusia holbrooki)

    PubMed Central

    Díez-del-Molino, David; Carmona-Catot, Gerard; Araguas, Rosa-Maria; Vidal, Oriol; Sanz, Nuria; García-Berthou, Emili; García-Marín, Jose-Luis

    2013-01-01

    Genetic analyses contribute to studies of biological invasions by mapping the origin and dispersal patterns of invasive species occupying new territories. Using microsatellite loci, we assessed the genetic diversity and spatial population structure of mosquitofish (Gambusia holbrooki) that had invaded Spanish watersheds, along with the American locations close to the suspected potential source populations. Mosquitofish populations from the Spanish streams that were studied had similar levels of genetic diversity to the American samples; therefore, these populations did not appear to have undergone substantial losses of genetic diversity during the invasion process. Population structure analyses indicated that the Spanish populations fell into four main clusters, which were primarily associated with hydrography. Dispersal patterns indicated that local populations were highly connected upstream and downstream through active dispersal, with an average of 21.5% fish from other locations in each population. After initially introducing fish to one location in a given basin, such dispersal potential might contribute to the spread and colonization of suitable habitats throughout the entire river basin. The two-dimension isolation-by-distance pattern here obtained, indicated that the human-mediated translocation of mosquitofish among the three study basins is a regular occurrence. Overall, both phenomena, high natural dispersal and human translocation, favor gene flow among river basins and the retention of high genetic diversity, which might help retain the invasive potential of mosquitofish populations. PMID:24358194

  15. Landscape corridors can increase invasion by an exotic species and reduce diversity of native species.

    SciTech Connect

    Resasco, Julian; et al,

    2014-04-01

    Abstract. Landscape corridors are commonly used to mitigate negative effects of habitat fragmentation, but concerns persist that they may facilitate the spread of invasive species. In a replicated landscape experiment of open habitat, we measured effects of corridors on the invasive fire ant, Solenopsis invicta, and native ants. Fire ants have two social forms: polygyne, which tend to disperse poorly but establish at high densities, and monogyne, which disperse widely but establish at lower densities. In landscapes dominated by polygyne fire ants, fire ant abundance was higher and native ant diversity was lower in habitat patches connected by corridors than in unconnected patches. Conversely, in landscapes dominated by monogyne fire ants, connectivity had no influence on fire ant abundance and native ant diversity. Polygyne fire ants dominated recently created landscapes, suggesting that these corridor effects may be transient. Our results suggest that corridors can facilitate invasion and they highlight the importance of considering species’ traits when assessing corridor utility.

  16. Conjunctival Melanoma With Morphologic Diversity and Orbital Invasion.

    PubMed

    Zoroquiain, Pablo; Nayman, Taylor; Fernandes, Bruno; Burnier, Miguel N

    2016-05-01

    A 68-year-old male with a previous history of 3 dysplastic skin nevi was referred to ophthalmology for a 1-year history of a progressive growth of a firm nodule in the lower left eyelid. Examination revealed a firm nodule in the inferior anterior orbit and mild conjunctival pigmentation on the left inferior fornix. A conjunctival incisional biopsy was taken, showing a melanoma. Because of the infiltration by the mass of the orbit on magnetic resonance imaging, an exenteration was performed. Histopathological analysis showed a unique conjunctival melanoma showing morphological diversity; specifically, a pattern characteristic of conjunctival melanoma, and the concurrent presence of staghorn patterns, signet-ring cells, and rosettoid patterns. Seven years of follow-up shows that the patient is alive with no further metastasis or recurrence. This report represents the first documented case of multiple morphologic patterns within a conjunctival melanoma. PMID:26909584

  17. β-elemene decreases cell invasion by upregulating E-cadherin expression in MCF-7 human breast cancer cells.

    PubMed

    Zhang, Xian; Zhang, Yang; Li, Yinghua

    2013-08-01

    Inactivation of E-cadherin results in cell migration and invasion, hence leading to cancer aggressiveness and metastasis. Downregulation of E-cadherin is closely correlated with a poor prognosis in invasive breast cancer. Thus, re-introducing E-cadherin is a novel strategy for cancer therapy. The aim of the present study was to determine the effects of the traditional Chinese medicine, β-elemene (ELE), on E-cadherin expression, cell migration and invasion in the breast cancer cell line MCF-7. MCF-7 cells were treated with 50 and 100 µg/ml ELE. E-cadherin mRNA was analyzed by reverse transcription‑polymerase chain reaction. E-cadherin protein levels were determined by immunofluorescence and western blot assays. Cell motility was measured by a Transwell assay. ELE increased both the protein and mRNA levels of E-cadherin, accompanied by decreased cell migration and invasion. Further analysis demonstrated that ELE upregulated estrogen receptor‑α (ERα) and metastasis-associated protein 3 (MTA3), and decreased the nuclear transcription factor Snail. In conclusion, our results demonstrate that ELE decreases cell migration and invasion by upregulating E-cadherin expression via controlling the ERα/MTA3/Snail signaling pathway. PMID:23732279

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

    PubMed

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

    2015-05-01

    Invasive, non-native species are one of the major causes of global biodiversity loss. Although they are, by definition, successful in their non-native range, their populations generally show major reductions in their genetic diversity during the demographic bottleneck they experience during colonization. By investigating the mitochondrial genetic diversity of an invasive non-native species, the stoat Mustela erminea, in New Zealand and comparing it to diversity in the species' native range in Great Britain, we reveal the opposite effect. We demonstrate that the New Zealand stoat population contains four mitochondrial haplotypes that have not been found in the native range. Stoats in Britain rely heavily on introduced rabbits Oryctolagus cuniculus as their primary prey and were introduced to New Zealand in a misguided attempt at biological control of rabbits, which had also been introduced there. While invasive stoats have since decimated the New Zealand avifauna, native stoat populations were themselves decimated by the introduction to Britain of Myxoma virus as a control measure for rabbits. We highlight the irony that while introduced species (rabbits) and subsequent biocontrol (myxomatosis) have caused population crashes of native stoats, invasive stoats in New Zealand, which were also introduced for biological control, now contain more genetic haplotypes than their most likely native source. PMID:25655531

  19. Genetic diversity of HPV16 and HPV18 in Brazilian patients with invasive cervical cancer.

    PubMed

    Vidal, Joao Paulo C B; Felix, Shayany Pinto; Chaves, Cláudia B P; Patury, Patrícia; Franco, Vanessa F; de Morais, Evaneide A; de Carvalho, Neile A; Carvalho, Aurenice C L; Almeida Neto, Olimpio F; Vieira, Lina Maria T M; Correa, Flavia Miranda; Martins, Luís Felipe Leite; Negrão, Antonio; de Almeida, Liz Maria; Moreira, Miguel Angelo Martins

    2016-07-01

    Cervical cancer is the fourth most common cancer among women, and ∼70-80% of these cancers are associated with two human papillomavirus types: HPV16 and HPV18. Several studies have reported that intra-type diversity is associated with the progression of infection to invasive cancer. Herein, we report the genetic diversity of HPV16 and HPV18 in a cohort of 594 Brazilian women with invasive cervical cancer and describe the prevalence of lineages and intra-type diversity prior to the implementation of the public immunization program in Brazil. HPV detection and genotyping were performed using PCR, PGMY/GP primers, and DNA extracted from fresh tumors. The HPV16 (378 women) and HPV18 (80 women) lineages were identified by PCR and sequencing of the LCR and E6 fragments, followed by SNV comparison and phylogenetic analysis. In our cohort, was found a higher frequency of the lineage A (in 217 women), followed by lineage D (in 97 women) and lineages B and C (in 10 women each) for HPV16; and a higher frequency of lineage A (in 56 women) followed by lineage B (in 15 women) in HPV18. The genetic diversity of HPV16 indicated a recent expansion of specific variants or a selective advantage that is associated with invasive cancer; this pattern was not observed for HPV18. J. Med. Virol. 88:1279-1287, 2016. © 2015 Wiley Periodicals, Inc. PMID:26694554

  20. Decreased stathmin-1 expression inhibits trophoblast proliferation and invasion and is associated with recurrent miscarriage.

    PubMed

    Tian, Fu-Ju; Qin, Chuan-Mei; Li, Xiao-Cui; Wu, Fan; Liu, Xiao-Rui; Xu, Wang-Ming; Lin, Yi

    2015-10-01

    Fetal trophoblasts invade endometrium and establish a complex interaction with the maternal microenvironment during early pregnancy. However, the molecular mechanisms regulating trophoblast migration and invasion at the maternal-fetal interface remain poorly understood. Immunohistochemistry and immunoblotting have shown that stathmin-1 (STMN1) was down-regulated significantly in placental villi tissue and trophoblasts from patients with recurrent miscarriage. In vitro, overexpression of STMN1 promoted human trophoblast proliferation, migration, and invasion, whereas knockdown of STMN1 inhibited these processes. In addition, knockdown of STMN1 down-regulated N-cadherin and up-regulated E-cadherin in trophoblasts, whereas E-cadherin was up-regulated and N-cadherin was down-regulated in recurrent miscarriage villi tissue. Knockdown of STMN1 attenuated cytoplasmic-nuclear translocation of β-catenin and in turn down-regulated trophoblast matrix metalloproteases. Furthermore, tumor necrosis factor-α (TNF-α) down-regulated STMN1 expression, and serum TNF-α expression correlated inversely with trophoblast STMN1 levels. Interestingly, M1 macrophage-derived TNF-α reduced trophoblast migration and invasion, and an anti-TNF-α antibody reversed this effect. Collectively, this study indicated that STMN1 may play a key role in regulating trophoblast invasion, and that impaired STMN1 expression may lead to abnormal trophoblast invasion and result in recurrent miscarriage. PMID:26272359

  1. A combination treatment with DNA methyltransferase inhibitors and suramin decreases invasiveness of breast cancer cells

    PubMed Central

    Borges, Sahra; Döppler, Heike R.

    2014-01-01

    The treatment of patients with invasive breast cancer remains a major issue because of the acquisition of drug resistance to conventional chemotherapy. Here we propose a new therapeutic strategy by combining DNA methyltransferase inhibitors (DMTIs) with suramin. Cytotoxic effects of suramin or combination treatment with DMTIs were determined in highly invasive breast cancer cell lines MDA-MB-231, BT-20 and HCC1954, or control cells. In addition, effects on cell invasion were determined in 3-dimensional cell culture assays. DMTI-mediated upregulation of Protein Kinase D1 (PKD1) expression was shown by Western blotting. Effects of suramin on PKD1 activity was determined in vitro and in cells. The importance of PKD1 in mediating the effects of such combination treatment in cell invasion was demonstrated using 3D cell culture assays. A proof of principal animal experiment was performed showing that PKD1 is critical for breast cancer growth. We show that when used in combination, suramin and DMTIs impair the invasive phenotype of breast cancer cells. We show that PKD1, a kinase that previously has been described as a suppressor of tumor cell invasion, is an interface for both FDA-approved drugs, since the additive effects observed are due to DMTI-mediated re-expression and suramin-induced activation of PKD1. Our data reveal a mechanism of how a combination treatment with non-toxic doses of suramin and DMTIs may be of therapeutic benefit for patients with aggressive, multi-drug resistant breast cancer. PMID:24510012

  2. Diversity of burial rates in convergent settings decreased as Earth aged

    PubMed Central

    Nicoli, Gautier; Moyen, Jean-François; Stevens, Gary

    2016-01-01

    The evolution and the growth of the continental crust is inextricably linked to the evolution of Earth’s geodynamic processes. The detrital zircon record within the continental crust, as well as the isotopic composition of this crust, indicates that the amount of juvenile felsic material decreased with time and that in geologically recent times, the generation of new crust is balanced by recycling of the crust back into the mantle within subduction zones. However it cannot always have been so; yet the nature of the crust and the processes of crustal reworking in the Precambrian Earth are not well constrained. Here we use both detrital zircon ages and metamorphic pressure-temperature-time (P-T-t) information from metasedimentary units deposited in proposed convergent settings from Archaean, Proterozoic and Phanerozoic terrains to characterize the evolution of minimum estimates of burial rate (km.Ma−1) as a function of the age of the rocks. The demonstrated decrease in burial rate correlates positively with a progressive decrease in the production of juvenile felsic crust in the Archaean and Proterozoic. Burial rates are also more diverse in the Archaean than in modern times. We interpret these features to reflect a progressive decrease in the diversity of tectonic processes from Archaean to present, coupled with the emergence of the uniquely Phanerozoic modern-style collision. PMID:27216133

  3. Diversity of burial rates in convergent settings decreased as Earth aged

    NASA Astrophysics Data System (ADS)

    Nicoli, Gautier; Moyen, Jean-François; Stevens, Gary

    2016-05-01

    The evolution and the growth of the continental crust is inextricably linked to the evolution of Earth’s geodynamic processes. The detrital zircon record within the continental crust, as well as the isotopic composition of this crust, indicates that the amount of juvenile felsic material decreased with time and that in geologically recent times, the generation of new crust is balanced by recycling of the crust back into the mantle within subduction zones. However it cannot always have been so; yet the nature of the crust and the processes of crustal reworking in the Precambrian Earth are not well constrained. Here we use both detrital zircon ages and metamorphic pressure-temperature-time (P-T-t) information from metasedimentary units deposited in proposed convergent settings from Archaean, Proterozoic and Phanerozoic terrains to characterize the evolution of minimum estimates of burial rate (km.Ma‑1) as a function of the age of the rocks. The demonstrated decrease in burial rate correlates positively with a progressive decrease in the production of juvenile felsic crust in the Archaean and Proterozoic. Burial rates are also more diverse in the Archaean than in modern times. We interpret these features to reflect a progressive decrease in the diversity of tectonic processes from Archaean to present, coupled with the emergence of the uniquely Phanerozoic modern-style collision.

  4. Diversity of burial rates in convergent settings decreased as Earth aged.

    PubMed

    Nicoli, Gautier; Moyen, Jean-François; Stevens, Gary

    2016-01-01

    The evolution and the growth of the continental crust is inextricably linked to the evolution of Earth's geodynamic processes. The detrital zircon record within the continental crust, as well as the isotopic composition of this crust, indicates that the amount of juvenile felsic material decreased with time and that in geologically recent times, the generation of new crust is balanced by recycling of the crust back into the mantle within subduction zones. However it cannot always have been so; yet the nature of the crust and the processes of crustal reworking in the Precambrian Earth are not well constrained. Here we use both detrital zircon ages and metamorphic pressure-temperature-time (P-T-t) information from metasedimentary units deposited in proposed convergent settings from Archaean, Proterozoic and Phanerozoic terrains to characterize the evolution of minimum estimates of burial rate (km.Ma(-1)) as a function of the age of the rocks. The demonstrated decrease in burial rate correlates positively with a progressive decrease in the production of juvenile felsic crust in the Archaean and Proterozoic. Burial rates are also more diverse in the Archaean than in modern times. We interpret these features to reflect a progressive decrease in the diversity of tectonic processes from Archaean to present, coupled with the emergence of the uniquely Phanerozoic modern-style collision. PMID:27216133

  5. Increasing land-use intensity decreases floral colour diversity of plant communities in temperate grasslands.

    PubMed

    Binkenstein, Julia; Renoult, Julien P; Schaefer, H Martin

    2013-10-01

    To preserve biodiversity and ecosystem functions in a globally changing world it is crucial to understand the effect of land use on ecosystem processes such as pollination. Floral colouration is known to be central in plant-pollinator interactions. To date, it is still unknown whether land use affects the colouration of flowering plant communities. To assess the effect of land use on the diversity and composition of flower colours in temperate grasslands, we collected data on the number of flowering plant species, blossom cover and flower reflectance spectra from 69 plant communities in two German regions, Schwäbische Alb (SA) and Hainich-Dün (HD). We analysed reflectance data of flower colours as they are perceived by honeybees and studied floral colour diversity based upon spectral loci of each flowering plant species in the Maxwell triangle. Before the first mowing, flower colour diversity decreased with increasing land-use intensity in SA, accompanied by a shift of mean flower colours of communities towards an increasing proportion of white blossom cover in both regions. By changing colour characteristics of grasslands, we suggest that increasing land-use intensity can affect the flower visitor fauna in terms of visitor behaviour and diversity. These changes may in turn influence plant reproduction in grassland plant communities. Our results indicate that land use is likely to affect communication processes between plants and flower visitors by altering flower colour traits. PMID:23568710

  6. Reduced Genetic Diversity and Increased Structure in American Mink on the Swedish Coast following Invasive Species Control.

    PubMed

    Zalewski, Andrzej; Zalewska, Hanna; Lunneryd, Sven-Gunnar; André, Carl; Mikusiński, Grzegorz

    2016-01-01

    Eradication and population reductions are often used to mitigate the negative impacts of non-native invasive species on native biodiversity. However, monitoring the effectiveness of non-native species control programmes is necessary to evaluate the efficacy of these measures. Genetic monitoring could provide valuable insights into temporal changes in demographic, ecological, and evolutionary processes in invasive populations being subject to control programmes. Such programmes should cause a decrease in effective population size and/or in genetic diversity of the targeted non-native species and an increase in population genetic structuring over time. We used microsatellite DNA data from American mink (Neovison vison) to determine whether the removal of this predator on the Koster Islands archipelago and the nearby Swedish mainland affected genetic variation over six consecutive years of mink culling by trappers as part of a population control programme. We found that on Koster Islands allelic richness decreased (from on average 4.53 to 3.55), genetic structuring increased, and effective population size did not change. In contrast, the mink population from the Swedish coast showed no changes in genetic diversity or structure, suggesting the stability of this population over 6 years of culling. Effective population size did not change over time but was higher on the coast than on the islands across all years. Migration rates from the islands to the coast were almost two times higher than from the coast to the islands. Most migrants leaving the coast were localised on the southern edge of the archipelago, as expected from the direction of the sea current between the two sites. Genetic monitoring provided valuable information on temporal changes in the population of American mink suggesting that this approach can be used to evaluate and improve control programmes of invasive vertebrates. PMID:27333328

  7. Reduced Genetic Diversity and Increased Structure in American Mink on the Swedish Coast following Invasive Species Control

    PubMed Central

    Zalewska, Hanna; Lunneryd, Sven-Gunnar; André, Carl; Mikusiński, Grzegorz

    2016-01-01

    Eradication and population reductions are often used to mitigate the negative impacts of non-native invasive species on native biodiversity. However, monitoring the effectiveness of non-native species control programmes is necessary to evaluate the efficacy of these measures. Genetic monitoring could provide valuable insights into temporal changes in demographic, ecological, and evolutionary processes in invasive populations being subject to control programmes. Such programmes should cause a decrease in effective population size and/or in genetic diversity of the targeted non-native species and an increase in population genetic structuring over time. We used microsatellite DNA data from American mink (Neovison vison) to determine whether the removal of this predator on the Koster Islands archipelago and the nearby Swedish mainland affected genetic variation over six consecutive years of mink culling by trappers as part of a population control programme. We found that on Koster Islands allelic richness decreased (from on average 4.53 to 3.55), genetic structuring increased, and effective population size did not change. In contrast, the mink population from the Swedish coast showed no changes in genetic diversity or structure, suggesting the stability of this population over 6 years of culling. Effective population size did not change over time but was higher on the coast than on the islands across all years. Migration rates from the islands to the coast were almost two times higher than from the coast to the islands. Most migrants leaving the coast were localised on the southern edge of the archipelago, as expected from the direction of the sea current between the two sites. Genetic monitoring provided valuable information on temporal changes in the population of American mink suggesting that this approach can be used to evaluate and improve control programmes of invasive vertebrates. PMID:27333328

  8. Non-native grass invasion associated with increases in insect diversity in temperate forest understory

    NASA Astrophysics Data System (ADS)

    Metcalf, Judith L.; Emery, Sarah M.

    2015-11-01

    Invasive plants can alter the structure and function of plant communities to such a degree that they can also have significant impacts on the insect communities. Because insects play an important role in many ecosystems, changes in these communities could have important implications, beyond their biodiversity value, for ecosystem function and diversity at other trophic levels. Microstegium vimineum is an annual C4 grass that is invasive in many eastern North American deciduous forests. Because this grass plays an important role in determining the plant community structure in the understory of these forests, it also has the potential to significantly alter understory insect communities. In this study we evaluated the relationship between M. vimineum and understory insect communities in a forest reserve in Kentucky, USA. Total insect abundance, richness and diversity showed a positive association with M. vimineum presence. Trophic analysis showed significantly higher abundances of herbivores where M. vimineum was present. Forb abundance, which serves as the primary food source for herbivorous insects in this system, was lower in sites invaded with M. vimineum. Invasion by this non-native was also associated with significant increases in aboveground plant biomass which was nearly 50% greater in invaded sites. These results indicate that the understory insect community may be responding to increased biomass rather than the loss of native forb food resources, which contradicts other studies that have examined relationships between M. vimineum invasion and insects. Our results provide evidence that invasive plants can provide benefits for other trophic levels, even when native plant biodiversity is lost.

  9. 17β-Estradiol treatment inhibits breast cell proliferation, migration and invasion by decreasing MALAT-1 RNA level

    SciTech Connect

    Zhao, Ziyi; Chen, Changjin; Liu, Yu; Wu, Chuanfang

    2014-03-07

    Highlights: • E2 affects not only estrogen-receptor α positive breast cells but also negative ones. • 100 nM E2 treatment affects breast cells proliferation, migration. • 100 nM E2 treatment functions in an estrogen-receptor α-independent way. • E2 treatment decreases MALAT-1 RNA level by post-transcriptional regulation. - Abstract: Breast cancer cells, which express estrogen receptor α (ERα), respond to estrogen in a concentration dependent fashion, resulting in proliferation or apoptosis. But breast cancer cells without ERα show no effect on low concentration of estrogen treatment. Proliferation, migration and invasion of MCF10a, MCF7 and MB231 cells treated with low (1 nM) or high (100 nM) dose of 17β-Estradiol (E2) was performed. We identified the effects of E2 on these breast cell lines, and looked for the difference in the presence and absence of ERα. Specifically, we looked for the changes of long non-coding RNA metastasis associated lung adenocarcinoma transcript 1 (MALAT-1), which is found extensively and highly expressed in several kinds of tumor cells, including breast carcinoma. It was observed that proliferation, migration and invasion of breast cells were greatly affected by high concentration E2 treatment and were not affected by low concentration E2 treatment in an ERα independent way. We found that the high concentration E2 treatment largely decreased MALAT-1 RNA level. Interestingly, MALAT-1 decreasing by knocking down showed similar effects on proliferation, migration and invasion. E2 treatment affects breast tumor or non-tumor cells proliferation, migration and invasion in an ERα -independent, but a dose-dependent way by decreasing the MALAT-1 RNA level.

  10. The effect of competition on the neutral intraspecific diversity of invasive species.

    PubMed

    Roques, L; Hosono, Y; Bonnefon, O; Boivin, T

    2015-08-01

    This paper deals with the effect of interspecific competition on the dynamics of neutral genetic diversity in a range-expanding population. The spread of an invasive species in an environment already hosting a resident competitor is described by a traveling wave solution with minimal speed, u(t,x) = U(x - c ∗ t), of a diffusive Lotka-Volterra competition model. The description of the dynamics of neutral genetic fractions in this wave is based on a decomposition of the wave into several components, as proposed by Roques et al. (Proc Natl Acad Sci USA 109(23):8828-8833, 2012). Our analytical results reveal that the wave can be either the pulled type, corresponding to strong erosion of the diversity, or the pushed type, corresponding to maintenance of the initial diversity. The pulled/pushed nature of the wave depends on the linear or nonlinear nature of the speed c *. Our results show that, for sufficiently strong competition, the speed is nonlinear, and therefore all of the genetic diversity in the invasive population is maintained. Conversely, in the absence of competition, or when competition is mild, the speed is linear, which means that only the furthest forward fraction in the initial invasive population eventually remains in the colonization front. Our numerical results also show that the sufficient conditions of Lewis et al. (J Math Biol 45(3):219-233, 2002) and Huang (J Dyn Differ Equ 22(2):285-297, 2010) for the linearity of the speed c * can still be improved, and they show that nonlinear speeds occur across a wide region of the parameter space, providing a counterpoint to recent analytical results suggesting that nonlinear speeds only occur in certain limiting cases. PMID:25193551

  11. Contrasting patterns in genetic diversity following multiple invasions of fresh and brackish waters.

    PubMed

    Kelly, David W; Muirhead, James R; Heath, Daniel D; Macisaac, Hugh J

    2006-10-01

    Biological invasions may combine the genetic effects of population bottlenecks and selection and thus provide valuable insight into the role of such processes during novel environmental colonizations. However, these processes are also influenced by multiple invasions, the number of individuals introduced and the degree of similarity between source and receiving habitats. The amphipod Gammarus tigrinus provides a useful model to assess these factors, as its invasion history has involved major environmental transitions. This species is native to the northwest Atlantic Ocean, although it invaded both brackish and freshwater habitats in the British Isles after introduction more than 65 years ago. It has also spread to similar habitats in Western Europe and, most recently, to Eastern Europe, the Baltic Sea, and the Laurentian Great Lakes. To examine sources of invasion and patterns of genetic change, we sampled populations from 13 native estuaries and 19 invaded sites and sequenced 542 bp of the mitochondrial COI gene. Strong native phylogeographical structure allowed us to unambiguously identify three allopatrically evolved clades (2.3-3.1% divergent) in invading populations, indicative of multiple introductions. The most divergent clades occurred in the British Isles and mainland Europe and were sourced from the St Lawrence and Chesapeake/Delaware Bay estuaries. A third clade was found in the Great Lakes and sourced to the Hudson River estuary. Despite extensive sampling, G. tigrinus did not occur in freshwater at putative source sites. Some European populations showed reduced genetic diversity consistent with bottlenecks, although selection effects cannot be excluded. The habitat distribution of clades in Europe was congruent with the known invasion history of secondary spread from the British Isles. Differences in salinity tolerance among lineages were suggested by patterns of habitat colonization by different native COI clades. Populations consisting of admixtures

  12. Decreased Diversity of the Oral Microbiota of Patients with Hepatitis B Virus-Induced Chronic Liver Disease: A Pilot Project.

    PubMed

    Ling, Zongxin; Liu, Xia; Cheng, Yiwen; Jiang, Xiawei; Jiang, Haiyin; Wang, Yuezhu; Li, Lanjuan

    2015-01-01

    Increasing evidence suggests that altered gut microbiota is implicated in the pathogenesis of hepatitis B virus-induced chronic liver disease (HBV-CLD). However, the structure and composition of the oral microbiota of patients with HBV-CLD remains unclear. High-throughput pyrosequencing showed that decreased oral bacterial diversity was found in patients with HBV-CLD. The Firmicutes/Bacteroidetes ratio was increased significantly, which indicated that dysbiosis of the oral microbiota participated in the process of HBV-CLD development. However, the changing patterns of the oral microbiota in patients with HBV-induced liver cirrhosis (LC) were almost similar to patients with chronic hepatitis B (CHB). HBV infection resulted in an increase in potential H2S- and CH3SH-producing phylotypes such as Fusobacterium, Filifactor, Eubacterium, Parvimonas and Treponema, which might contribute to the increased oral malodor. These key oral-derived phylotypes might invade into the gut as opportunistic pathogens and contribute to altering the composition of the gut microbiota. This study provided important clues that dysbiosis of the oral microbiota might be involved in the development of HBV-CLD. Greater understanding of the relationships between the dysbiosis of oral microbiota and the development of HBV-CLD might facilitate the development of non-invasive differential diagnostic procedures and targeted treatments of HBV-CLD patients harbouring specific oral phylotypes. PMID:26606973

  13. Decreased Diversity of the Oral Microbiota of Patients with Hepatitis B Virus-Induced Chronic Liver Disease: A Pilot Project

    PubMed Central

    Ling, Zongxin; Liu, Xia; Cheng, Yiwen; Jiang, Xiawei; Jiang, Haiyin; Wang, Yuezhu; Li, Lanjuan

    2015-01-01

    Increasing evidence suggests that altered gut microbiota is implicated in the pathogenesis of hepatitis B virus-induced chronic liver disease (HBV-CLD). However, the structure and composition of the oral microbiota of patients with HBV-CLD remains unclear. High-throughput pyrosequencing showed that decreased oral bacterial diversity was found in patients with HBV-CLD. The Firmicutes/Bacteroidetes ratio was increased significantly, which indicated that dysbiosis of the oral microbiota participated in the process of HBV-CLD development. However, the changing patterns of the oral microbiota in patients with HBV-induced liver cirrhosis (LC) were almost similar to patients with chronic hepatitis B (CHB). HBV infection resulted in an increase in potential H2S- and CH3SH-producing phylotypes such as Fusobacterium, Filifactor, Eubacterium, Parvimonas and Treponema, which might contribute to the increased oral malodor. These key oral-derived phylotypes might invade into the gut as opportunistic pathogens and contribute to altering the composition of the gut microbiota. This study provided important clues that dysbiosis of the oral microbiota might be involved in the development of HBV-CLD. Greater understanding of the relationships between the dysbiosis of oral microbiota and the development of HBV-CLD might facilitate the development of non-invasive differential diagnostic procedures and targeted treatments of HBV-CLD patients harbouring specific oral phylotypes. PMID:26606973

  14. Microbiome diversity of Aphis glycines with extensive superinfection in native and invasive populations.

    PubMed

    Bansal, Raman; Mian, M A Rouf; Michel, Andy P

    2014-02-01

    Associations among insects and microbes can lead to beneficial or parasitic interactions. Using 454 sequencing of 16S RNA genes, we compared microbiome diversity and abundance among field-collected (F) and laboratory-reared (L) populations of the invasive soybean aphid (Aphis glycines), a pest of soybean. Additionally, we screened A. glycines populations from native (Japan, South Korea and China) and invasive regions (North America) to broadly determine the microbiome diversity. Our results suggested that Arsenophonus (relative abundance of 54.6%), Buchnera (38.7%) and Wolbachia (3.7%) were the major bacteria associated with A. glycines. Arsenophonus was the most abundant in F populations but was significantly reduced in L populations; additional bacteria species also had lower relative abundances in L populations. Native and invasive populations were largely similar in bacteria communities and revealed substantial superinfection of Arsenophonus and Wolbachia. The lone exception was a lack of Arsenophonus in A. glycines from Japan. Divergent selection pressures among natural and laboratory populations were inferred as factors driving the differential bacterial communities observed. Our results will allow for improved comparative aphid-symbiont research and broaden our understanding of the interactions among insects, endosymbionts and their environments. PMID:24596263

  15. Genetic diversity in three invasive clonal aquatic species in New Zealand

    PubMed Central

    2010-01-01

    Background Elodea canadensis, Egeria densa and Lagarosiphon major are dioecious clonal species which are invasive in New Zealand and other regions. Unlike many other invasive species, the genetic variation in New Zealand is very limited. Clonal reproduction is often considered an evolutionary dead end, even though a certain amount of genetic divergence may arise due to somatic mutations. The successful growth and establishment of invasive clonal species may be explained not by adaptability but by pre-existing ecological traits that prove advantageous in the new environment. We studied the genetic diversity and population structure in the North Island of New Zealand using AFLPs and related the findings to the number of introductions and the evolution that has occurred in the introduced area. Results Low levels of genetic diversity were found in all three species and appeared to be due to highly homogeneous founding gene pools. Elodea canadensis was introduced in 1868, and its populations showed more genetic structure than those of the more recently introduced of E. densa (1946) and L. major (1950). Elodea canadensis and L. major, however, had similar phylogeographic patterns, in spite of the difference in time since introduction. Conclusions The presence of a certain level of geographically correlated genetic structure in the absence of sexual reproduction, and in spite of random human dispersal of vegetative propagules, can be reasonably attributed to post-dispersal somatic mutations. Direct evidence of such evolutionary events is, however, still insufficient. PMID:20565861

  16. Isoliquiritigenin inhibits migration and invasion of prostate cancer cells: possible mediation by decreased JNK/AP-1 signaling.

    PubMed

    Kwon, Gyoo Taik; Cho, Han Jin; Chung, Won-Yoon; Park, Kwang-Kyun; Moon, Aree; Park, Jung Han Yoon

    2009-09-01

    Isoliquiritigenin (ISL, 4,2',4'-trihydroxychalcone), which is found in licorice, shallot and bean sprouts, is a potent antioxidant with anti-inflammatory and anti-carcinogenic effects. The purpose of this study was to investigate the effects of ISL treatment on the migration, invasion and adhesion characteristics of DU145 human prostate cancer cells. DU145 cells were cultured in the presence of 0-20 micromol/L ISL with or without 10 microg/L epidermal growth factor (EGF). ISL inhibited basal and EGF-induced cell migration, invasion and adhesion dose dependently. ISL decreased EGF-induced secretion of urokinase-type plasminogen activator (uPA), matrix metalloproteinase (MMP)-9, tissue inhibitor of metalloproteinase-1 (TIMP-1), and vascular endothelial growth factor (VEGF), but increased TIMP-2 secretion in a concentration-dependent manner. In addition, ISL decreased the protein levels of integrin-alpha2, intercellular adhesion molecule (ICAM) and vascular cell adhesion molecule (VCAM), and mRNA levels of uPA, MMP-9, VEGF, ICAM and integrin-alpha2. Furthermore, basal and EGF-induced activator protein (AP)-1 binding activity and phosphorylation of Jun N-terminal kinase (JNK), c-Jun and Akt were decreased after ISL treatment. However, phosphorylation of extracellular signal-regulated kinase (ERK)1/2 and p38 mitogen-activated protein kinase was not altered. The JNK inhibitor SP600125 inhibited basal and EGF-induced secretion of uPA, VEGF, MMP-9 and TIMP-1, as well as AP-1 DNA binding activity and cell migration. These results provide evidence for the role of ISL as a potent antimetastatic agent, which can markedly inhibit the metastatic and invasive capacity of prostate cancer cells. The inhibition of JNK/AP-1 signaling may be one of the mechanisms by which ISL inhibits cancer cell invasion and migration. PMID:18824345

  17. The influence of Aster x salignus Willd. Invasion on the diversity of soil yeast communities

    NASA Astrophysics Data System (ADS)

    Glushakova, A. M.; Kachalkin, A. V.; Chernov, I. Yu.

    2016-07-01

    The annual dynamics of yeast communities were studied in the soddy-podzolic soil under the thickets of Aster x salignus Willd., one of the widespread invasive plant species in central Russia. Yeast groups in the soils under continuous aster thickets were found to differ greatly from the yeast communities in the soils under the adjacent indigenous meadow vegetation. In both biotopes the same species ( Candida vartiovaarae, Candida sake, and Cryptococcus terreus) are dominants. However, in the soils under indigenous grasses, eurybiontic yeasts Rhodotorula mucilaginosa, which almost never occur in the soil under aster, are widespread. In the soil under aster, the shares of other typical epiphytic and pedobiontic yeast fungi (ascomycetic species Wickerhamomyces aniomalus, Barnettozyma californica and basidiomycetic species Cystofilobasidium macerans, Guehomyces pullulans) significantly increase. Thus, the invasion of Aster x salignus has a clear effect on soil yeast complexes reducing their taxonomic and ecological diversity.

  18. Population Structure and Genetic Diversity of Native and Invasive Populations of Solanum rostratum (Solanaceae)

    PubMed Central

    Zhao, Jiali; Solís-Montero, Lislie; Lou, Anru; Vallejo-Marín, Mario

    2013-01-01

    Aims We investigate native and introduced populations of Solanum rostratum, an annual, self-compatible plant that has been introduced around the globe. This study is the first to compare the genetic diversity of Solanum rostratum between native and introduced populations. We aim to (1) determine the level of genetic diversity across the studied regions; (2) explore the likely origins of invasive populations in China; and (3) investigate whether there is the evidence of multiple introductions into China. Methods We genotyped 329 individuals at 10 microsatellite loci to determine the levels of genetic diversity and to investigate population structure of native and introduced populations of S. rostratum. We studied five populations in each of three regions across two continents: Mexico, the U.S.A. and China. Important Findings We found the highest genetic diversity among Mexican populations of S. rostratum. Genetic diversity was significantly lower in Chinese and U.S.A. populations, but we found no regional difference in inbreeding coefficients (FIS) or population differentiation (FST). Population structure analyses indicate that Chinese and U.S.A. populations are more closely related to each other than to sampled Mexican populations, revealing that introduced populations in China share an origin with the sampled U.S.A. populations. The distinctiveness between some introduced populations indicates multiple introductions of S. rostratum into China. PMID:24224008

  19. ERβ decreases the invasiveness of triple-negative breast cancer cells by regulating mutant p53 oncogenic function

    PubMed Central

    Bado, Igor; Nikolos, Fotis; Rajapaksa, Gayani; Gustafsson, Jan-Åke; Thomas, Christoforos

    2016-01-01

    Most (80%) of the triple-negative breast cancers (TNBCs) express mutant p53 proteins that acquire oncogenic activities including promoting metastasis. We previously showed that wild-type ERβ (ERβ1) impedes epithelial to mesenchymal transition (EMT) and decreases the invasiveness of TNBC cells. In the present study we searched for signaling pathways that ERβ1 uses to inhibit EMT and invasion in TNBC cells. We show that ERβ1 binds to and opposes the transcriptional activity of mutant p53 at the promoters of genes that regulate metastasis. p63 that transcriptionally cooperates with mutant p53 also binds to ERβ1. Downregulation of p63 represses the epithelial phenotype of ERβ1-expressing cells and alters the expression of mutant p53 target genes. These results describe a novel mechanism through which ERβ1 can disturb oncogenic signals to inhibit aggressiveness in TNBCs. PMID:26871946

  20. Luteolin decreases the attachment, invasion and cytotoxicity of UPEC in bladder epithelial cells and inhibits UPEC biofilm formation.

    PubMed

    Shen, Xiao-fei; Ren, Lai-bin; Teng, Yan; Zheng, Shuang; Yang, Xiao-long; Guo, Xiao-juan; Wang, Xin-yuan; Sha, Kai-hui; Li, Na; Xu, Guang-ya; Tian, Han-wen; Wang, Xiao-ying; Liu, Xiao-kang; Li, Jingyu; Huang, Ning

    2014-10-01

    Urinary tract infection (UTI), primarily caused by uropathogenic Escherichia coli (UPEC), is one of the most common infectious diseases worldwide. Emerging antibiotic resistance requires novel treatment strategies. Luteolin, a dietary polyphenolic flavonoid, has been confirmed as a potential antimicrobial agent. Here, we evaluated the sub-MICs of luteolin for potential properties to modulate the UPEC infection. We found that luteolin significantly decreased the attachment and invasion of UPEC J96 or CFT073 in human bladder epithelial cell lines T24. Meanwhile, obvious decreased expression of type 1 fimbriae adhesin fimH gene, lower bacterial surface hydrophobicity and swimming motility, were observed in luteolin-pretreated UPEC. Furthermore, luteolin could attenuate UPEC-induced cytotoxicity in T24 cells, which manifested as decreased activity of lactate dehydrogenase (LDH). Simultaneously, the inhibition of luteolin on UPEC-induced cytotoxicity was confirmed by ethidium bromide/acridine orange staining. Finally, the luteolin-pretreated UPEC showed a lower ability of biofilm formation. Collectively, these results indicated that luteolin decreased the attachment and invasion of UPEC in bladder epithelial cells, attenuated UPEC-induced cytotoxicity and biofilm formation via down-regulating the expression of adhesin fimH gene, reducing the bacterial surface hydrophobicity and motility. PMID:25051393

  1. Functional Diversity of Boreal Bog Plant Species Decreases Seasonal Variation of Ecosystem Carbon Sink Function

    NASA Astrophysics Data System (ADS)

    Korrensalo, A.

    2015-12-01

    Species diversity has been found to decrease the temporal variance of productivity of a plant community, and diversity in species responses to environmental factors seems to make a plant community more stable in changing conditions. Boreal bogs are nutrient poor peatland ecosystems where the number of plant species is low but the species differ greatly in their growth form. In here we aim to assess the role of the variation in photosynthesis between species for the temporal variation in ecosystem carbon sink function. To quantify the photosynthetic properties and their seasonal variation for different bog plant species we measured photosynthetic parameters and stress-inducing chlorophyll fluorescence of vascular plant and Sphagnum moss species in a boreal bog over a growing season. We estimated monthly gross photosynthesis (PG) of the whole study site based on species level light response curves and leaf area development. The estimated PG was further compared with a gross primary production (GPP) estimate measured by eddy covariance (EC) technique. The sum of upscaled PG estimates agreed well with the GPP estimate measured by the EC technique. The contributions of the species and species groups to the ecosystem level PG changed over the growing season. The sharp mid-summer peak in sedge PG was balanced by more stable PG of evergreen shrubs and Sphagna. Species abundance rather than differences in photosynthetic properties between species and growth forms determined the most productive plants on the ecosystem scale. Sphagna had lower photosynthesis and clorophyll fluorescence than vascular plants but were more productive on the ecosystem scale throughout the growing season due to their high areal coverage. These results show that the diversity of growth forms stabilizes the seasonal variation of the ecosystem level PG in an ombrotrophic bog ecosystem. This may increase the resilience of the ecosystem to changing environmental conditions.

  2. Resistome diversity in cattle and the environment decreases during beef production.

    PubMed

    Noyes, Noelle R; Yang, Xiang; Linke, Lyndsey M; Magnuson, Roberta J; Dettenwanger, Adam; Cook, Shaun; Geornaras, Ifigenia; Woerner, Dale E; Gow, Sheryl P; McAllister, Tim A; Yang, Hua; Ruiz, Jaime; Jones, Kenneth L; Boucher, Christina A; Morley, Paul S; Belk, Keith E

    2016-01-01

    Antimicrobial resistant determinants (ARDs) can be transmitted from livestock systems through meat products or environmental effluents. The public health risk posed by these two routes is not well understood, particularly in non-pathogenic bacteria. We collected pooled samples from 8 groups of 1741 commercial cattle as they moved through the process of beef production from feedlot entry through slaughter. We recorded antimicrobial drug exposures and interrogated the resistome at points in production when management procedures could potentially influence ARD abundance and/or transmission. Over 300 unique ARDs were identified. Resistome diversity decreased while cattle were in the feedlot, indicating selective pressure. ARDs were not identified in beef products, suggesting that slaughter interventions may reduce the risk of transmission of ARDs to beef consumers. This report highlights the utility and limitations of metagenomics for assessing public health risks regarding antimicrobial resistance, and demonstrates that environmental pathways may represent a greater risk than the food supply. PMID:26952213

  3. Irradiation induces diverse changes in invasive potential in cancer cell lines.

    PubMed

    Fujita, Mayumi; Yamada, Shigeru; Imai, Takashi

    2015-12-01

    Cancer patients without metastasis are generally considered as candidates for curative localized radiation therapy. However, while the benefits of localized radiation have been demonstrated by many clinical studies, recurrences or distant metastases that develop after local treatment remain a major therapeutic challenge. Several in vitro and in vivo studies have reported that irradiation may subsequently alter tumor aggression by reducing or promoting the invasiveness of the remaining cancer cells after radiation, which appears to differ depending on the form of radiation, as well as the investigated cell lines. Cell lines recapitulate cancer heterogeneity based on the characteristics reflected in their genetic abnormalities, and thus can be used as a tool to investigate the genetic basis of cancer aggression. Importantly, molecular insights into this process would allow us to tailor drug treatments for use in combination with local radiation treatment. This review summarizes the diverse responses of cancer cell invasiveness induced by radiation, and discusses the possible molecular pathways and the genetic variations that may affect radiation-altered invasion. PMID:26410035

  4. Serotypes and Clonal Diversity of Streptococcus pneumoniae Causing Invasive Disease in the Era of PCV13 in Catalonia, Spain.

    PubMed

    Del Amo, Eva; Esteva, Cristina; Hernandez-Bou, Susanna; Galles, Carmen; Navarro, Marian; Sauca, Goretti; Diaz, Alvaro; Gassiot, Paula; Marti, Carmina; Larrosa, Nieves; Ciruela, Pilar; Jane, Mireia; Sá-Leão, Raquel; Muñoz-Almagro, Carmen

    2016-01-01

    The aim of this study was to study the serotypes and clonal diversity of pneumococci causing invasive pneumococcal disease in Catalonia, Spain, in the era of 13-valent pneumococcal conjugate vaccine (PCV13). In our region, this vaccine is only available in the private market and it is estimated a PCV13 vaccine coverage around 55% in children. A total of 1551 pneumococcal invasive isolates received between 2010 and 2013 in the Molecular Microbiology Department at Hospital Sant Joan de Déu, Barcelona, were included. Fifty-two serotypes and 249 clonal types-defined by MLST-were identified. The most common serotypes were serotype 1 (n = 182; 11.7%), 3 (n = 145; 9.3%), 19A (n = 137; 8.8%) and 7F (n = 122; 7.9%). Serotype 14 was the third most frequent serotype in children < 2 years (15 of 159 isolates). PCV7 serotypes maintained their proportion along the period of study, 16.6% in 2010 to 13.4% in 2013, whereas there was a significant proportional decrease in PCV13 serotypes, 65.3% in 2010 to 48.9% in 2013 (p<0.01). This decrease was mainly attributable to serotypes 19A and 7F. Serotype 12F achieved the third position in 2013 (n = 22, 6.4%). The most frequent clonal types found were ST306 (n = 154, 9.9%), ST191 (n = 111, 7.2%), ST989 (n = 85, 5.5%) and ST180 (n = 80, 5.2%). Despite their decrease, PCV13 serotypes continue to be a major cause of disease in Spain. These results emphasize the need for complete PCV13 vaccination. PMID:26953887

  5. Serotypes and Clonal Diversity of Streptococcus pneumoniae Causing Invasive Disease in the Era of PCV13 in Catalonia, Spain

    PubMed Central

    del Amo, Eva; Esteva, Cristina; Hernandez-Bou, Susanna; Galles, Carmen; Navarro, Marian; Sauca, Goretti; Diaz, Alvaro; Gassiot, Paula; Marti, Carmina; Larrosa, Nieves; Ciruela, Pilar; Jane, Mireia; Sá-Leão, Raquel; Muñoz-Almagro, Carmen

    2016-01-01

    The aim of this study was to study the serotypes and clonal diversity of pneumococci causing invasive pneumococcal disease in Catalonia, Spain, in the era of 13-valent pneumococcal conjugate vaccine (PCV13). In our region, this vaccine is only available in the private market and it is estimated a PCV13 vaccine coverage around 55% in children. A total of 1551 pneumococcal invasive isolates received between 2010 and 2013 in the Molecular Microbiology Department at Hospital Sant Joan de Déu, Barcelona, were included. Fifty-two serotypes and 249 clonal types—defined by MLST—were identified. The most common serotypes were serotype 1 (n = 182; 11.7%), 3 (n = 145; 9.3%), 19A (n = 137; 8.8%) and 7F (n = 122; 7.9%). Serotype 14 was the third most frequent serotype in children < 2 years (15 of 159 isolates). PCV7 serotypes maintained their proportion along the period of study, 16.6% in 2010 to 13.4% in 2013, whereas there was a significant proportional decrease in PCV13 serotypes, 65.3% in 2010 to 48.9% in 2013 (p<0.01). This decrease was mainly attributable to serotypes 19A and 7F. Serotype 12F achieved the third position in 2013 (n = 22, 6.4%). The most frequent clonal types found were ST306 (n = 154, 9.9%), ST191 (n = 111, 7.2%), ST989 (n = 85, 5.5%) and ST180 (n = 80, 5.2%). Despite their decrease, PCV13 serotypes continue to be a major cause of disease in Spain. These results emphasize the need for complete PCV13 vaccination. PMID:26953887

  6. Distinguishing between invasions and habitat changes as drivers of diversity loss among California's freshwater fishes.

    PubMed

    Light, Theo; Marchetti, Michael P

    2007-04-01

    Many of California's native populations of freshwater fish are in serious decline, as are freshwater faunas worldwide. Habitat loss and alteration, hydrologic modification, water pollution, and invasions have been identified as major drivers of these losses. Because these potential causes of decline are frequently correlated, it is difficult to separate direct from indirect effects of each factor and to appropriately rank their importance for conservation action. Recently a few authors have questioned the conservation significance of invasions, suggesting that they are "passengers" rather than "drivers" of ecological change. We compiled an extensive, watershed-level data set of fish presence and conservation status, land uses, and hydrologic modifications in California and used an information theoretic approach (Akaike's information criterion, AIC) and path analysis to evaluate competing models of native fish declines. Hydrologic modification (impoundments and diversions), invasions, and proportion of developed land were all predictive of the number of extinct and at-risk native fishes in California watersheds in the AIC analysis. Although nonindigenous fish richness was the best single predictor (after native richness) of fishes of conservation concern, the combined ranking of models containing hydrologic modification variables was slightly higher than that of models containing nonindigenous richness. Nevertheless, the path analysis indicated that the effects of both hydrologic modification and development on fishes of conservation concern were largely indirect, through their positive effects on nonindigenous fish richness. The best-fitting path model was the driver model, which included no direct effects of abiotic disturbance on native fish declines. Our results suggest that, for California freshwater fishes, invasions are the primary direct driver of extinctions and population declines, whereas the most damaging effect of habitat alteration is the tendency of

  7. Targeting choline phospholipid metabolism: GDPD5 and GDPD6 silencing decrease breast cancer cell proliferation, migration, and invasion.

    PubMed

    Cao, Maria Dung; Cheng, Menglin; Rizwan, Asif; Jiang, Lu; Krishnamachary, Balaji; Bhujwalla, Zaver M; Bathen, Tone F; Glunde, Kristine

    2016-08-01

    Abnormal choline phospholipid metabolism is associated with oncogenesis and tumor progression. We have investigated the effects of targeting choline phospholipid metabolism by silencing two glycerophosphodiesterase genes, GDPD5 and GDPD6, using small interfering RNA (siRNA) in two breast cancer cell lines, MCF-7 and MDA-MB-231. Treatment with GDPD5 and GDPD6 siRNA resulted in significant increases in glycerophosphocholine (GPC) levels, and no change in the levels of phosphocholine or free choline, which further supports their role as GPC-specific regulators in breast cancer. The GPC levels were increased more than twofold during GDPD6 silencing, and marginally increased during GDPD5 silencing. DNA laddering was negative in both cell lines treated with GDPD5 and GDPD6 siRNA, indicating absence of apoptosis. Treatment with GDPD5 siRNA caused a decrease in cell viability in MCF-7 cells, while GDPD6 siRNA treatment had no effect on cell viability in either cell line. Decreased cell migration and invasion were observed in MDA-MB-231 cells treated with GDPD5 or GDPD6 siRNA, where a more pronounced reduction in cell migration and invasion was observed under GDPD5 siRNA treatment as compared with GDPD6 siRNA treatment. In conclusion, GDPD6 silencing increased the GPC levels in breast cancer cells more profoundly than GDPD5 silencing, while the effects of GDPD5 silencing on cell viability/proliferation, migration, and invasion were more severe than those of GDPD6 silencing. Our results suggest that silencing GDPD5 and GDPD6 alone or in combination may have potential as a new molecular targeting strategy for breast cancer treatment. Copyright © 2016 John Wiley & Sons, Ltd. PMID:27356959

  8. Inter-varietal interactions among plants in genotypically diverse mixtures tend to decrease herbivore performance.

    PubMed

    Grettenberger, Ian M; Tooker, John F

    2016-09-01

    Much research has explored the effects of plant species diversity on herbivore populations, but far less has considered effects of plant genotypic diversity, or how abiotic stressors, like drought, can modify effects. Mechanisms by which plant genotypic diversity affects herbivore populations remain largely unresolved. We used greenhouse studies with a model system of wheat (Triticum aestivum L.) and bird cherry-oat aphid (Rhopalosiphum padi L.) to determine whether the genotypic diversity of a plant's neighborhood influences performance and fitness of herbivores on a focal plant and if drought changes the influence of neighborhood diversity. Taken across all varieties we tested, plant-plant interactions in diverse neighborhoods reduced aphid performance and generated associational resistance, although effects on aphids depended on variety identity. In diverse mixtures, drought stress greatly diminished the genotypic diversity-driven reduction in aphid performance. Neighborhood diversity influenced mother aphid size, and appeared to partially explain how plant-plant interactions reduced the number of offspring produced in mixtures. Plant size did not mediate effects on aphid performance, although neighborhood diversity reduced plant mass across varieties and watering treatments. Our results suggest inter-varietal interactions in genotypic mixtures can affect herbivore performance in the absence of herbivore movement and that abiotic stress may diminish any effects. Accounting for how neighborhood diversity influences resistance of an individual plant to herbivores will help aid development of mixtures of varieties for managing insect pests and clarify the role of plant genotypic diversity in ecosystems. PMID:27170329

  9. Activated carbon decreases invasive plant growth by mediating plant–microbe interactions

    PubMed Central

    Nolan, Nicole E.; Kulmatiski, Andrew; Beard, Karen H.; Norton, Jeanette M.

    2015-01-01

    There is growing appreciation for the idea that plant–soil interactions (e.g. allelopathy and plant–microbe feedbacks) may explain the success of some non-native plants. Where this is the case, native plant restoration may require management tools that change plant–soil interactions. Activated carbon (AC) is one such potential tool. Previous research has shown the potential for high concentrations of AC to restore native plant growth to areas dominated by non-natives on a small scale (1 m × 1 m plots). Here we (i) test the efficacy of different AC concentrations at a larger scale (15 m × 15 m plots), (ii) measure microbial responses to AC treatment and (iii) use a greenhouse experiment to identify the primary mechanism, allelopathy versus microbial changes, through which AC impacts native and non-native plant growth. Three years after large-scale applications, AC treatments decreased non-native plant cover and increased the ratio of native to non-native species cover, particularly at concentrations >400 g m−2. Activated carbon similarly decreased non-native plant growth in the greenhouse. This effect, however, was only observed in live soils, suggesting that AC effects were microbially mediated and not caused by direct allelopathy. Bacterial community analysis of field soils indicated that AC increased the relative abundance of an unidentified bacterium and an Actinomycetales and decreased the relative abundance of a Flavobacterium, suggesting that these organisms may play a role in AC effects on plant growth. Results support the idea that manipulations of plant–microbe interactions may provide novel and effective ways of directing plant growth and community development (e.g. native plant restoration). PMID:25387751

  10. Activated carbon decreases invasive plant growth by mediating plant-microbe interactions.

    PubMed

    Nolan, Nicole E; Kulmatiski, Andrew; Beard, Karen H; Norton, Jeanette M

    2014-01-01

    There is growing appreciation for the idea that plant-soil interactions (e.g. allelopathy and plant-microbe feedbacks) may explain the success of some non-native plants. Where this is the case, native plant restoration may require management tools that change plant-soil interactions. Activated carbon (AC) is one such potential tool. Previous research has shown the potential for high concentrations of AC to restore native plant growth to areas dominated by non-natives on a small scale (1 m × 1 m plots). Here we (i) test the efficacy of different AC concentrations at a larger scale (15 m × 15 m plots), (ii) measure microbial responses to AC treatment and (iii) use a greenhouse experiment to identify the primary mechanism, allelopathy versus microbial changes, through which AC impacts native and non-native plant growth. Three years after large-scale applications, AC treatments decreased non-native plant cover and increased the ratio of native to non-native species cover, particularly at concentrations >400 g m(-2). Activated carbon similarly decreased non-native plant growth in the greenhouse. This effect, however, was only observed in live soils, suggesting that AC effects were microbially mediated and not caused by direct allelopathy. Bacterial community analysis of field soils indicated that AC increased the relative abundance of an unidentified bacterium and an Actinomycetales and decreased the relative abundance of a Flavobacterium, suggesting that these organisms may play a role in AC effects on plant growth. Results support the idea that manipulations of plant-microbe interactions may provide novel and effective ways of directing plant growth and community development (e.g. native plant restoration). PMID:25387751

  11. Population structure and diversity of an invasive pine needle pathogen reflects anthropogenic activity.

    PubMed

    Barnes, Irene; Wingfield, Michael J; Carbone, Ignazio; Kirisits, Thomas; Wingfield, Brenda D

    2014-09-01

    Dothistroma septosporum is a haploid fungal pathogen that causes a serious needle blight disease of pines, particularly as an invasive alien species on Pinus radiata in the Southern Hemisphere. During the course of the last two decades, the pathogen has also incited unexpected epidemics on native and non-native pine hosts in the Northern Hemisphere. Although the biology and ecology of the pathogen has been well documented, there is a distinct lack of knowledge regarding its movement or genetic diversity in many of the countries where it is found. In this study we determined the global population diversity and structure of 458 isolates of D. septosporum from 14 countries on six continents using microsatellite markers. Populations of the pathogen in the Northern Hemisphere, where pines are native, displayed high genetic diversities and included both mating types. Most of the populations from Europe showed evidence for random mating, little population differentiation and gene flow between countries. Populations in North America (USA) and Asia (Bhutan) were genetically distinct but migration between these continents and Europe was evident. In the Southern Hemisphere, the population structure and diversity of D. septosporum reflected the anthropogenic history of the introduction and establishment of plantation forestry, particularly with Pinus radiata. Three introductory lineages in the Southern Hemisphere were observed. Countries in Africa, that have had the longest history of pine introductions, displayed the greatest diversity in the pathogen population, indicating multiple introductions. More recent introductions have occurred separately in South America and Australasia where the pathogen population is currently reproducing clonally due to the presence of only one mating type. PMID:25478155

  12. Population structure and diversity of an invasive pine needle pathogen reflects anthropogenic activity

    PubMed Central

    Barnes, Irene; Wingfield, Michael J; Carbone, Ignazio; Kirisits, Thomas; Wingfield, Brenda D

    2014-01-01

    Dothistroma septosporum is a haploid fungal pathogen that causes a serious needle blight disease of pines, particularly as an invasive alien species on Pinus radiata in the Southern Hemisphere. During the course of the last two decades, the pathogen has also incited unexpected epidemics on native and non-native pine hosts in the Northern Hemisphere. Although the biology and ecology of the pathogen has been well documented, there is a distinct lack of knowledge regarding its movement or genetic diversity in many of the countries where it is found. In this study we determined the global population diversity and structure of 458 isolates of D. septosporum from 14 countries on six continents using microsatellite markers. Populations of the pathogen in the Northern Hemisphere, where pines are native, displayed high genetic diversities and included both mating types. Most of the populations from Europe showed evidence for random mating, little population differentiation and gene flow between countries. Populations in North America (USA) and Asia (Bhutan) were genetically distinct but migration between these continents and Europe was evident. In the Southern Hemisphere, the population structure and diversity of D. septosporum reflected the anthropogenic history of the introduction and establishment of plantation forestry, particularly with Pinus radiata. Three introductory lineages in the Southern Hemisphere were observed. Countries in Africa, that have had the longest history of pine introductions, displayed the greatest diversity in the pathogen population, indicating multiple introductions. More recent introductions have occurred separately in South America and Australasia where the pathogen population is currently reproducing clonally due to the presence of only one mating type. PMID:25478155

  13. Resistome diversity in cattle and the environment decreases during beef production

    PubMed Central

    Noyes, Noelle R; Yang, Xiang; Linke, Lyndsey M; Magnuson, Roberta J; Dettenwanger, Adam; Cook, Shaun; Geornaras, Ifigenia; Woerner, Dale E; Gow, Sheryl P; McAllister, Tim A; Yang, Hua; Ruiz, Jaime; Jones, Kenneth L; Boucher, Christina A; Morley, Paul S; Belk, Keith E

    2016-01-01

    Antimicrobial resistant determinants (ARDs) can be transmitted from livestock systems through meat products or environmental effluents. The public health risk posed by these two routes is not well understood, particularly in non-pathogenic bacteria. We collected pooled samples from 8 groups of 1741 commercial cattle as they moved through the process of beef production from feedlot entry through slaughter. We recorded antimicrobial drug exposures and interrogated the resistome at points in production when management procedures could potentially influence ARD abundance and/or transmission. Over 300 unique ARDs were identified. Resistome diversity decreased while cattle were in the feedlot, indicating selective pressure. ARDs were not identified in beef products, suggesting that slaughter interventions may reduce the risk of transmission of ARDs to beef consumers. This report highlights the utility and limitations of metagenomics for assessing public health risks regarding antimicrobial resistance, and demonstrates that environmental pathways may represent a greater risk than the food supply. DOI: http://dx.doi.org/10.7554/eLife.13195.001 PMID:26952213

  14. Orthotopic urinary diversion after radical cystectomy in treatment of muscle invasive bladder cancer.

    PubMed

    Jovan, Hadži-Djokić; Vladan, Andrejević; Tomislav, Pejčić; Miodrag, Aćimović; Uroš, Babić; Miodrag, Stanić; Zoran, Džamić

    2014-01-01

    Surgical treatment of invasive carcinoma of the bladder in males includes total cystectomy removal of the prostate, seminal vesicles, and the distal parts of the urethers and the pelvic lymph node dissection as well. At this moment it is not possible to recommend a particular type of urinary diversion, but today in clinical practice commonly used derivative are ileal orthotopic neobladder as the continent one and ileal conduit as non-continent urinary diversion. Continent urinary diversion after radical cystectomy are the result of the application of technological innovation in surgery, but also knowledge, imagination and skill of well trained urologist. This type of operation significantly improves the quality of life in patients who underwent radical cystectomy, and the proposal is to operate whenever there is a possibility for this type of procedure. Also it is very important, during surgery to respect oncological principles, of complete removal of tumorous tissue and that the functional principle of ensur- ing that the patients have daytime and also nighttime continence later on after the surgery. PMID:25782228

  15. Artichoke polyphenols induce apoptosis and decrease the invasive potential of the human breast cancer cell line MDA-MB231.

    PubMed

    Mileo, Anna Maria; Di Venere, Donato; Linsalata, Vito; Fraioli, Rocco; Miccadei, Stefania

    2012-09-01

    The human breast cancer cell line, estrogen receptor negative, MDA-MB231, was used to evaluate the antitumor effect of polyphenolic extracts from the edible part of artichokes (AEs). Treatment of cancer cells reduced cell viability and inhibited cell growth in a dose-dependent manner. Importantly, AEs did not have any effect on normal breast epithelial cell line, MCF10A. Chlorogenic acid (ChA), the most representative component of the polyphenolic fraction of artichoke, had no prominent effects on the cell death rate of MDA-MB231 cells. The addition of AEs to the cells, rather than ChA, triggered apoptosis via a mitochondrial and a death-receptor pathway, as shown by the activation of caspase-9 and caspase-8, respectively. Furthermore, an increase of the Bax:Bcl2 ratio and up-regulation of cyclin-dependent kinase inhibitor, p21(WAF1), crucial apoptotic players, were documented. According to our data on activation of caspase-9, a loss of mitochondrial transmembrane potential (Ψ(m)) was shown. Cell motility and invasion capabilities were remarkably inhibited by AEs-treatment in highly invasive MDA-MB231 cells. In addition, a significant decrease of proteolytic activity of metalloproteinase-2 protein (MMP-2), involved in degrading components of the extracellular matrix, was detected. Our findings indicate that AEs reduced cell viability, inhibited cell growth, triggered apoptotic mechanisms, and showed inhibitory properties against the invasive behavior of MDA-MB231 cancer cell line. Altogether, these data indicate the potential chemopreventive activity of artichoke polyphenolic extracts. PMID:22170094

  16. Bird functional diversity decreases with time since disturbance: Does patchy prescribed fire enhance ecosystem function?.

    PubMed

    Sitters, Holly; Di Stefano, Julian; Christie, Fiona; Swan, Matthew; York, Alan

    2016-01-01

    Animal species diversity is often associated with time since disturbance, but the effects of disturbances such as fire on functional diversity are unknown. Functional diversity measures the range, abundance, and distribution of trait values in a community, and links changes in species composition with the consequences for ecosystem function. Improved understanding of the relationship between time since fire (TSF) and functional diversity is critical given that the frequency of both prescribed fire and wildfire is expected to increase. To address this knowledge gap, we examined responses of avian functional diversity to TSF and two direct measures of environmental heterogeneity, plant diversity, and structural heterogeneity. We surveyed birds across a 70-year chronosequence spanning four vegetation types in southeast Australia. Six bird functional traits were used to derive four functional diversity indices (richness, evenness, divergence, and dispersion) and the effects of TSF, plant diversity and structural heterogeneity on species richness and the functional diversity indices were examined using mixed models. We used a regression tree method to identify traits associated with species more common in young vegetation. Functional richness and dispersion were negatively associated with TSF in all vegetation types, suggesting that recent prescribed fire generates heterogeneous vegetation and provides greater opportunities for resource partitioning. Species richness was not significantly associated with TSF, and is probably an unreliable surrogate for functional diversity in fire-prone systems. A positive, relationship between functional evenness and structural heterogeneity was comnon to all vegetation types, suggesting that fine-scale (tens of meters) structural variation can enhance ecosystem function. Species more common in young vegetation were primarily linked by their specialist diets, indicating that ecosystem services such as seed dispersal and insect control

  17. 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

  18. Decreased FOXF1 promotes hepatocellular carcinoma tumorigenesis, invasion, and stemness and is associated with poor clinical outcome

    PubMed Central

    Zhao, Zhen-guo; Wang, De-qiang; Hu, De-fei; Li, You-sheng; Liu, Shuang-hai

    2016-01-01

    Forkhead box F1 (FOXF1), a member of the forkhead transcription factor superfamily, plays critical roles in the progression of certain types of cancers. However, the expression and function of FOXF1 in human hepatocellular carcinoma (HCC) are still unclear. Quantitative real-time reverse transcription polymerase chain reaction, Western blotting, and immunohistochemistry detected the relatively lower expression status of FOXF1 in HCC cases. Soft agar and transwell assays clearly demonstrated that FOXF1-knockdown cells showed significantly increased in vitro cell tumorigenesis and invasion, and FOXF1-overexpressing cells had significantly reduced growth and invasion potential. Our study also examined the role of FOXF1 in HCC cell stemness by sphere formation, aldehyde dehydrogenase (ALDH1) activity, and CD44/133-positive cell analysis. Enforced FOXF1 expression decreased HCC cell stemness, and the downregulation of FOXF1 promoted cancer cell stemness. The in vivo study showed that overexpressed FOXF1 inhibits nude mouse tumorigenicity with downregulation of CD44 and proliferating cell nuclear antigen. More importantly, loss of FOXF1 expression was linked to poor overall survival time by Kaplan–Meier analysis. PMID:27042124

  19. Amplicon pyrosequencing reveals the soil microbial diversity associated with invasive Japanese barberry (Berberis thunbergii DC.).

    PubMed

    Coats, V C; Pelletreau, K N; Rumpho, M E

    2014-03-01

    The soil microbial community acts as a reservoir of microbes that directly influences the structure and composition of the aboveground plant community, promotes plant growth, increases stress tolerance and mediates local patterns of nutrient cycling. Direct interactions between plants and rhizosphere-dwelling microorganisms occur at, or near, the surface of the root. Upon introduction and establishment, invasive plants modify the soil microbial communities and soil biochemistry affecting bioremediation efforts and future plant communities. Here, we used tag-encoded FLX amplicon 454 pyrosequencing (TEFAP) to characterize the bacterial and fungal community diversity in the rhizosphere of Berberis thunbergii DC. (Japanese barberry) from invasive stands in coastal Maine to investigate effects of soil type, soil chemistry and surrounding plant cover on the soil microbial community structure. Acidobacteria, Actinobacteria, Proteobacteria and Verrucomicrobia were the dominant bacterial phyla, whereas fungal communities were comprised mostly of Ascomycota and Basidiomycota phyla members, including Agaricomycetes and Sordariomycetes. Bulk soil chemistry had more effect on the bacterial community structure than the fungal community. An effect of geographic location was apparent in the rhizosphere microbial communities, yet it was less significant than the effect of surrounding plant cover. These data demonstrate a high degree of spatial variation in the rhizosphere microbial communities of Japanese barberry with apparent effects of soil chemistry, location and canopy cover on the microbial community structure. PMID:24118303

  20. High-Level Genetic Diversity among Invasive Streptococcus pneumoniae Isolates in Turkey.

    PubMed

    Guldemir, Dilek; Acar, Sumeyra; Otgun, Selin Nar; Unaldi, Ozlem; Gozalan, Aysegul; Ertek, Mustafa; Durmaz, Riza

    2016-05-20

    This study obtained information on the serotypes and molecular typing characteristics of Streptococcus pneumoniae strains causing invasive diseases in Turkey. Sixty-eight S. pneumoniae isolates causing invasive pneumococcal diseases were collected from different regions of Turkey from 2009 to 2011. The isolates were characterized by performing multilocus sequence typing (MLST), pulsed-field gel electrophoresis (PFGE), and capsular serotyping, and 25 different serotypes were identified. Serotypes 19F, 23F, 1, 14, and 7F were common and accounted for 52.9% of all the serotypes. In addition, 54 different PFGE profiles (pulsotypes) were observed. Twenty-three of the 68 (33.8%) isolates were clustered into 9 pulsotypes. MLST analysis yielded 36 sequence types, of which 12 (33.3%) were novel. A comparison of results with the global pneumococcal MLST database by performing eBURST analysis showed that our strains belonged to 20 different clonal complexes and 5 singletons. In addition, we identified 4 new alleles: 2 gdh, 1 xpt, and 1 ddl. Thus, the results of this study highlighted a high level of diversity among pneumococcal isolates. In addition, the study identified a case of possible capsular switching. PMID:26255730

  1. Invasion of dwarf bamboo into alpine snow-meadows in northern Japan: pattern of expansion and impact on species diversity.

    PubMed

    Kudo, Gaku; Amagai, Yukihiro; Hoshino, Buho; Kaneko, Masami

    2011-09-01

    Recently, a dwarf bamboo species,Sasa kurilensis; Poaceae, has invaded into alpine snow-meadows in the wilderness area of the Taisetsu Mountains, northern Japan. This dwarf bamboo species has a wide distribution range from lowland to alpine sites of snowy regions. Because of the formation of dense evergreen culms and an extensive rhizome system, other plants are excluded following invasion by this dwarf bamboo, resulting in low species diversity. Dwarf bamboo originally inhabited the leeward slopes of alpine dwarf pine (Pinus pumila) clumps in alpine regions. During the last 32 years, however, dwarf bamboo has expanded its distribution area by up to 47% toward snow-meadows, especially on southeastern facing slopes. This rapid change may be related to the decrease in soil moisture and expansion of the annual growing period caused by the recent acceleration of snowmelt time. A multiyear census revealed that the density of bamboo culms increased 30-150% during 2 years, and the annual expansion of bamboo rhizomes was 39 cm on average. In addition to the expansion of bamboo clumps by vegetative growth, the possibility of migration by seed dispersal was also suggested by a genet analysis. With the increase in culm density, the species richness of snow-meadow vegetation decreased to less than one-quarter of the original level due to intense shading by dwarf bamboo. The rapid vegetation change in these almost pristine alpine environments isolated from the human activity implies that global climate change already influences the alpine ecosystem. PMID:22393485

  2. Invasion of dwarf bamboo into alpine snow-meadows in northern Japan: pattern of expansion and impact on species diversity

    PubMed Central

    Kudo, Gaku; Amagai, Yukihiro; Hoshino, Buho; Kaneko, Masami

    2011-01-01

    Recently, a dwarf bamboo species,Sasa kurilensis; Poaceae, has invaded into alpine snow-meadows in the wilderness area of the Taisetsu Mountains, northern Japan. This dwarf bamboo species has a wide distribution range from lowland to alpine sites of snowy regions. Because of the formation of dense evergreen culms and an extensive rhizome system, other plants are excluded following invasion by this dwarf bamboo, resulting in low species diversity. Dwarf bamboo originally inhabited the leeward slopes of alpine dwarf pine (Pinus pumila) clumps in alpine regions. During the last 32 years, however, dwarf bamboo has expanded its distribution area by up to 47% toward snow-meadows, especially on southeastern facing slopes. This rapid change may be related to the decrease in soil moisture and expansion of the annual growing period caused by the recent acceleration of snowmelt time. A multiyear census revealed that the density of bamboo culms increased 30–150% during 2 years, and the annual expansion of bamboo rhizomes was 39 cm on average. In addition to the expansion of bamboo clumps by vegetative growth, the possibility of migration by seed dispersal was also suggested by a genet analysis. With the increase in culm density, the species richness of snow-meadow vegetation decreased to less than one-quarter of the original level due to intense shading by dwarf bamboo. The rapid vegetation change in these almost pristine alpine environments isolated from the human activity implies that global climate change already influences the alpine ecosystem. PMID:22393485

  3. Investigation of the genetic diversity of an invasive whitefly (Bemisia tabaci) in China using both mitochondrial and nuclear DNA markers.

    PubMed

    Chu, D; Gao, C S; De Barro, P; Wan, F H; Zhang, Y J

    2011-08-01

    It is often considered that reduced genetic variation due to bottlenecks and founder effects limits the capacity for species to establish in new environments and subsequently spread. The recent invasion (during the past five years) of an alien whitefly, one member of Bemisia tabaci cryptic species complex, referred to as Mediterranean (herein referred to as Q-type) in Shandong Province, China, provides an ideal opportunity to study the changes in genetic variation between its home range in the Mediterranean region and its invasion range. Using both the mitochondrial cytochrome oxidase I (mtCOI) and nuclear (microsatellite) DNA, we show that Q in Shandong likely originated in the western Mediterranean. We also found that the haplotype diversity was low compared with its presumed geographic origin, whereas microsatellite allele diversity showed no such decline. A key factor in invasions is the establishment of females and so bottleneck and founder events can lead to a very rapid and considerable loss of mitochondrial diversity. The lack of haplotype diversity in Shandong supports the interpretation that, at one or more points between the western Mediterranean and China, the invading Q lost haplotype diversity, most probably through the serial process of establishment and redistribution through trade in ornamental plants. However, the loss in haplotype diversity does not necessarily mean that nuclear allelic diversity should also decline. Provided females can mate freely with whichever males are available, allelic diversity can be maintained or even increased relative to the origin of the invader. Our findings may offer some explanation to the apparent paradox between the concept of reduced genetic variation limiting adaptation to new environments and the observed low diversity in successful invaders. PMID:21320364

  4. INSECT FAUNA DIVERSITY AMONG INVASIVE, NON-INVASIVE AND NATIVE CONGENERS AND IMPLICATIONS FOR THE ENEMY RELEASE HYPOTHESIS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The enemy release hypothesis (ERH) has been frequently invoked to explain the naturalization and spread of introduced species. One ramification of the ERH is that invasive plants sustain less herbivore pressure than do the native species. Empirical studies testing the ERH have mostly involved two-w...

  5. Soil-occupancy effects of invasive and native grassland plant species on composition and diversity of mycorrhizal associations

    USGS Publications Warehouse

    Jordan, Nicholas R.; Aldrich-Wolfe, Laura; Huerd, Sheri C.; Larson, Diane L.; Muehlbauer, Gary

    2012-01-01

    Diversified grasslands that contain native plant species can produce biofuels, support sustainable grazing systems, and produce other ecosystem services. However, ecosystem service production can be disrupted by invasion of exotic perennial plants, and these plants can have soil-microbial “legacies” that may interfere with establishment and maintenance of diversified grasslands even after effective management of the invasive species. The nature of such legacies is not well understood, but may involve suppression of mutualisms between native species and soil microbes. In this study, we tested the hypotheses that legacy effects of invasive species change colonization rates, diversity, and composition of arbuscular-mycorrhizal fungi (AMF) associated with seedlings of co-occurring invasive and native grassland species. In a glasshouse, experimental soils were conditioned by cultivating three invasive grassland perennials, three native grassland perennials, and a native perennial mixture. Each was grown separately through three cycles of growth, after which we used T-RFLP analysis to characterize AMF associations of seedlings of six native perennial and six invasive perennial species grown in these soils. Legacy effects of soil conditioning by invasive species did not affect AMF richness in seedling roots, but did affect AMF colonization rates and the taxonomic composition of mycorrhizal associations in seedling roots. Moreover, native species were more heavily colonized by AMF and roots of native species had greater AMF richness (number of AMF operational taxonomic units per seedling) than did invasive species. The invasive species used to condition soil in this experiment have been shown to have legacy effects on biomass of native seedlings, reducing their growth in this and a previous similar experiment. Therefore, our results suggest that successful plant invaders can have legacies that affect soil-microbial associations of native plants and that these effects

  6. Calibrating Snakehead Diversity with DNA Barcodes: Expanding Taxonomic Coverage to Enable Identification of Potential and Established Invasive Species

    PubMed Central

    Serrao, Natasha R.; Steinke, Dirk; Hanner, Robert H.

    2014-01-01

    Detecting and documenting the occurrence of invasive species outside their native range requires tools to support their identification. This can be challenging for taxa with diverse life stages and/or problematic or unresolved morphological taxonomies. DNA barcoding provides a potent method for identifying invasive species, as it allows for species identification at all life stages, including fragmentary remains. It also provides an efficient interim taxonomic framework for quantifying cryptic genetic diversity by parsing barcode sequences into discontinuous haplogroup clusters (typical of reproductively isolated species) and labelling them with unique alphanumeric identifiers. Snakehead fishes are a diverse group of opportunistic predators endemic to Asia and Africa that may potentially pose significant threats as aquatic invasive species. At least three snakehead species (Channa argus, C. maculata, and C. marulius) are thought to have entered North America through the aquarium and live-food fish markets, and have established populations, yet their origins remain unclear. The objectives of this study were to assemble a library of DNA barcode sequences derived from expert identified reference specimens in order to determine the identity and aid invasion pathway analysis of the non-indigenous species found in North America using DNA barcodes. Sequences were obtained from 121 tissue samples representing 25 species and combined with public records from GenBank for a total of 36 putative species, which then partitioned into 49 discrete haplogroups. Multiple divergent clusters were observed within C. gachua, C. marulius, C. punctata and C. striata suggesting the potential presence of cryptic species diversity within these lineages. Our findings demonstrate that DNA barcoding is a valuable tool for species identification in challenging and under-studied taxonomic groups such as snakeheads, and provides a useful framework for inferring invasion pathway analysis. PMID

  7. Calibrating snakehead diversity with DNA barcodes: expanding taxonomic coverage to enable identification of potential and established invasive species.

    PubMed

    Serrao, Natasha R; Steinke, Dirk; Hanner, Robert H

    2014-01-01

    Detecting and documenting the occurrence of invasive species outside their native range requires tools to support their identification. This can be challenging for taxa with diverse life stages and/or problematic or unresolved morphological taxonomies. DNA barcoding provides a potent method for identifying invasive species, as it allows for species identification at all life stages, including fragmentary remains. It also provides an efficient interim taxonomic framework for quantifying cryptic genetic diversity by parsing barcode sequences into discontinuous haplogroup clusters (typical of reproductively isolated species) and labelling them with unique alphanumeric identifiers. Snakehead fishes are a diverse group of opportunistic predators endemic to Asia and Africa that may potentially pose significant threats as aquatic invasive species. At least three snakehead species (Channa argus, C. maculata, and C. marulius) are thought to have entered North America through the aquarium and live-food fish markets, and have established populations, yet their origins remain unclear. The objectives of this study were to assemble a library of DNA barcode sequences derived from expert identified reference specimens in order to determine the identity and aid invasion pathway analysis of the non-indigenous species found in North America using DNA barcodes. Sequences were obtained from 121 tissue samples representing 25 species and combined with public records from GenBank for a total of 36 putative species, which then partitioned into 49 discrete haplogroups. Multiple divergent clusters were observed within C. gachua, C. marulius, C. punctata and C. striata suggesting the potential presence of cryptic species diversity within these lineages. Our findings demonstrate that DNA barcoding is a valuable tool for species identification in challenging and under-studied taxonomic groups such as snakeheads, and provides a useful framework for inferring invasion pathway analysis. PMID

  8. Diversity of mycorrhizal fungi of terrestrial orchids: compatibility webs, brief encounters, lasting relationships and alien invasions.

    PubMed

    Bonnardeaux, Yumiko; Brundrett, Mark; Batty, Andrew; Dixon, Kingsley; Koch, John; Sivasithamparam, K

    2007-01-01

    The diversity of mycorrhizal fungi associated with an introduced weed-like South African orchid (Disa bracteata) and a disturbance-intolerant, widespread, native West Australian orchid (Pyrorchis nigricans) were compared by molecular identification of the fungi isolated from single pelotons. Molecular identification revealed both orchids were associated with fungi from diverse groups in the Rhizoctonia complex with worldwide distribution. Symbiotic germination assays confirmed the majority of fungi isolated from pelotons were mycorrhizal and a factorial experiment uncovered complex webs of compatibility between six terrestrial orchids and 12 fungi from Australia and South Africa. Two weed-like (disturbance-tolerant rapidly spreading) orchids - D. bracteata and the indigenous Australian Microtis media, had the broadest webs of mycorrhizal fungi. In contrast, other native orchids had relatively small webs of fungi (Diuris magnifica and Thelymitra crinita), or germinated exclusively with their own fungus (Caladenia falcata and Pterostylis sanguinea). Orchids, such as D. bracteata and M. media, which form relationships with diverse webs of fungi, had apparent specificity that decreased with time, as some fungi had brief encounters with orchids that supported protocorm formation but not subsequent seedling growth. The interactions between orchid mycorrhizal fungi and their hosts are discussed. PMID:17289365

  9. Decreased fish diversity found near marble industry effluents in River Barandu, Pakistan.

    PubMed

    Mulk, Shahi; Korai, Abdul Latif; Azizullah, Azizullah; Khattak, Muhammad Nasir Khan

    2016-01-01

    In a recently published study we observed that effluents from marble industry affected physicochemical characteristics of River Barandu in District Buner, Pakistan. These changes in water quality due to marble effluents may affect fish community. The present study was therefore conducted to evaluate the impacts of marble industry effluents on fish communities in River Barandu using abundance, richness, diversity and evenness of fish species as end point criteria. The fish samples were collected by local fishermen on monthly basis from three selected sites (upstream, effluents/industrial, and downstream sites). During the study period, a total of 18 fish species were found belonging to 4 orders, 5 families and 11 genera. The Cyprinidae was observed to be the dominant family at all the three selected sites. Lower abundance and species diversity was observed at the industrial (22%) and downstream sites (33%) as compared to the upstream site (45%). Effluents of marble industry were associated with lower abundance of species in River Barandu. It is recommended that industries should be shifted away from the vicinity of river and their effluents must be treated before discharging to prevent further loss of fish abundance and diversity in the River. PMID:26497021

  10. Temporal analysis of mtDNA variation reveals decreased genetic diversity in least terns

    USGS Publications Warehouse

    Draheim, Hope M.; Baird, Patricia; Haig, Susan M.

    2012-01-01

    The Least Tern (Sternula antillarum) has undergone large population declines over the last century as a result of direct and indirect anthropogenic factors. The genetic implications of these declines are unknown. We used historical museum specimens (pre-1960) and contemporary (2001–2005) samples to examine range-wide phylogeographic patterns and investigate potential loss in the species' genetic variation. We obtained sequences (522 bp) of the mitochondrial gene for NADH dehydrogenase subunit 6 (ND6) from 268 individuals from across the species' range. Phylogeographic analysis revealed no association with geography or traditional subspecies designations. However, we detected potential reductions in genetic diversity in contemporary samples from California and the Atlantic coast Least Tern from that in historical samples, suggesting that current genetic diversity in Least Tern populations is lower than in their pre-1960 counterparts. Our results offer unique insights into changes in the Least Tern's genetic diversity over the past century and highlight the importance and utility of museum specimens in studies of conservation genetics.

  11. Apigenin up-regulates transgelin and inhibits invasion and migration of colorectal cancer through decreased phosphorylation of AKT.

    PubMed

    Chunhua, Li; Donglan, Lin; Xiuqiong, Fu; Lihua, Zhang; Qin, Fan; Yawei, Liu; Liang, Zhao; Ge, Wen; Linlin, Jing; Ping, Zeng; Kun, Li; Xuegang, Sun

    2013-10-01

    Colorectal cancer (CRC) is a major cause of morbidity and mortality throughout the world. Apigenin is a flavonoid that possesses various clinically relevant properties such as anti-tumour, anti-platelet and anti-inflammatory activities. Our results showed that apigenin has anti-proliferation, anti-invasion and anti-migration effects in three kinds of colorectal adenocarcinoma cell lines, namely SW480, DLD-1 and LS174T. Proteomic analysis with SW480 indicated that apigenin up-regulated the expression of transgelin (TAGLN) in mitochondria to exert its anti-tumour growth and anti-metastasis effects. Real-time quantitative polymerase chain reaction (RQ-PCR) and western blot confirm the up-regulation in all the three colorectal adenocarcinoma cells. An inverse correlation was observed between TAGLN expression and CRC metastasis in tissue microarray staining. TAGLN siRNA increased the viability of SW480. Apigenin decreased the expression of MMP-9 in a dose-dependent manner. Transfection of three truncated forms of TAGLN and wild type has identified TAGLN as a repressor of MMP-9 expression. A synergetic effect was observed in overexpression of TAGLN wild type and apigenin treatment which manifested as lowered phosphorylation of AKT Ser473 and ATK Thr308. In an orthotopic CRC model, apigenin inhibited tumour growth and metastasis to liver and lung. In conclusion, our research provided direct evidence that apigenin inhibited tumour growth and metastasis both in vitro and in vivo. Apigenin up-regulated TAGLN and hence down-regulated MMP-9 expression through decreasing phosphorylation of Akt at Ser473 and in particular Thr308 to prevent cell proliferation and migration. PMID:23773626

  12. Increased Inter-Colony Fusion Rates Are Associated with Reduced COI Haplotype Diversity in an Invasive Colonial Ascidian Didemnum vexillum

    PubMed Central

    Smith, Kirsty F.; Stefaniak, Lauren; Saito, Yasunori; Gemmill, Chrissen E. C.; Cary, S. Craig; Fidler, Andrew E.

    2012-01-01

    Considerable progress in our understanding of the population genetic changes associated with biological invasions has been made over the past decade. Using selectively neutral loci, it has been established that reductions in genetic diversity, reflecting founder effects, have occurred during the establishment of some invasive populations. However, some colonial organisms may actually gain an ecological advantage from reduced genetic diversity because of the associated reduction in inter-colony conflict. Here we report population genetic analyses, along with colony fusion experiments, for a highly invasive colonial ascidian, Didemnum vexillum. Analyses based on mitochondrial cytochrome oxidase I (COI) partial coding sequences revealed two distinct D. vexillum clades. One COI clade appears to be restricted to the probable native region (i.e., north-west Pacific Ocean), while the other clade is present in widely dispersed temperate coastal waters around the world. This clade structure was supported by 18S ribosomal DNA (rDNA) sequence data, which revealed a one base-pair difference between the two clades. Recently established populations of D. vexillum in New Zealand displayed greatly reduced COI genetic diversity when compared with D. vexillum in Japan. In association with this reduction in genetic diversity was a significantly higher inter-colony fusion rate between randomly paired New Zealand D. vexillum colonies (80%, standard deviation ±18%) when compared with colonies found in Japan (27%, standard deviation ±15%). The results of this study add to growing evidence that for colonial organisms reductions in population level genetic diversity may alter colony interaction dynamics and enhance the invasive potential of newly colonizing species. PMID:22303442

  13. 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

  14. 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

  15. Habitat Loss other than Fragmentation per se Decreased Nuclear and Chloroplast Genetic Diversity in a Monoecious Tree

    PubMed Central

    Shen, Dong-Wei; Chen, Xiao-Yong

    2012-01-01

    Generally, effect of fragmentation per se on biodiversity has not been separated from the effect of habitat loss. In this paper, using nDNA and cpDNA SSRs, we studied genetic diversity of Castanopsis sclerophylla (Lindl. & Paxton) Schotty populations and decoupled the effects of habitat loss and fragmentation per se. We selected seven nuclear and six cpDNA microsatellite loci and genotyped 460 individuals from mainland and island populations, which were located in the impoundment created in 1959. Number of alleles per locus of populations in larger habitats was significantly higher than that in smaller habitats. There was a significant relationship between the number of alleles per locus and habitat size. Based on this relationship, the predicted genetic diversity of an imaginary population of size equaling the total area of the islands was lower than that of the global population on the islands. Re-sampling demonstrated that low genetic diversity of populations in small habitats was caused by unevenness in sample size. Fisher's α index was similar among habitat types. These results indicate that the decreased nuclear and chloroplast genetic diversity of populations in smaller habitats was mainly caused by habitat loss. For nuclear and chloroplast microsatellite loci, values of FST were 0.066 and 0.893, respectively, and the calculated pollen/seed dispersal ratio was 162.2. When separated into pre-and post-fragmentation cohorts, pollen/seed ratios were 121.2 and 189.5, respectively. Our results suggest that habitat loss explains the early decrease in genetic diversity, while fragmentation per se may play a major role in inbreeding and differentiation among fragmented populations and later loss of genetic diversity. PMID:22723951

  16. Habitat loss other than fragmentation per se decreased nuclear and chloroplast genetic diversity in a monoecious tree.

    PubMed

    Zhang, Xin; Shi, Miao-Miao; Shen, Dong-Wei; Chen, Xiao-Yong

    2012-01-01

    Generally, effect of fragmentation per se on biodiversity has not been separated from the effect of habitat loss. In this paper, using nDNA and cpDNA SSRs, we studied genetic diversity of Castanopsis sclerophylla (Lindl. & Paxton) Schotty populations and decoupled the effects of habitat loss and fragmentation per se. We selected seven nuclear and six cpDNA microsatellite loci and genotyped 460 individuals from mainland and island populations, which were located in the impoundment created in 1959. Number of alleles per locus of populations in larger habitats was significantly higher than that in smaller habitats. There was a significant relationship between the number of alleles per locus and habitat size. Based on this relationship, the predicted genetic diversity of an imaginary population of size equaling the total area of the islands was lower than that of the global population on the islands. Re-sampling demonstrated that low genetic diversity of populations in small habitats was caused by unevenness in sample size. Fisher's α index was similar among habitat types. These results indicate that the decreased nuclear and chloroplast genetic diversity of populations in smaller habitats was mainly caused by habitat loss. For nuclear and chloroplast microsatellite loci, values of F(ST) were 0.066 and 0.893, respectively, and the calculated pollen/seed dispersal ratio was 162.2. When separated into pre-and post-fragmentation cohorts, pollen/seed ratios were 121.2 and 189.5, respectively. Our results suggest that habitat loss explains the early decrease in genetic diversity, while fragmentation per se may play a major role in inbreeding and differentiation among fragmented populations and later loss of genetic diversity. PMID:22723951

  17. Decreased virus population diversity in p53-null mice infected with weakly oncogenic Abelson virus.

    PubMed

    Marchlik, Erica; Kalman, Richard; Rosenberg, Naomi

    2005-09-01

    The Abelson murine leukemia virus (Ab-MLV), like other retroviruses that contain v-onc genes, arose following a recombination event between a replicating retrovirus and a cellular oncogene. Although experimentally validated models have been presented to address the mechanism by which oncogene capture occurs, very little is known about the events that influence emerging viruses following the recombination event that incorporates the cellular sequences. One feature that may play a role is the genetic makeup of the host in which the virus arises; a number of host genes, including oncogenes and tumor suppressor genes, have been shown to affect the pathogenesis of many murine leukemia viruses. To examine how a host gene might affect an emerging v-onc gene-containing retrovirus, we studied the weakly oncogenic Ab-MLV-P90A strain, a mutant that generates highly oncogenic variants in vivo, and compared the viral populations in normal mice and mice lacking the p53 tumor suppressor gene. While variants arose in both p53+/+ and p53-/- tumors, the samples from the wild-type animals contained a more diverse virus population. Differences in virus population diversity were not observed when wild-type and null animals were infected with a highly oncogenic wild-type strain of Ab-MLV. These results indicate that p53, and presumably other host genes, affects the selective forces that operate on virus populations in vivo and likely influences the evolution of oncogenic retroviruses such as Ab-MLV. PMID:16140739

  18. Nitrogen deposition and management practices increase soil microbial biomass carbon but decrease diversity in Moso bamboo plantations

    NASA Astrophysics Data System (ADS)

    Li, Quan; Song, Xinzhang; Gu, Honghao; Gao, Fei

    2016-06-01

    Because microbial communities play a key role in carbon (C) and nitrogen (N) cycling, changes in the soil microbial community may directly affect ecosystem functioning. However, the effects of N deposition and management practices on soil microbes are still poorly understood. We studied the effects of these two factors on soil microbial biomass carbon (MBC) and community composition in Moso bamboo plantations using high-throughput sequencing of the 16S rRNA gene. Plantations under conventional (CM) or intensive management (IM) were subjected to one of four N treatments for 30 months. IM and N addition, both separately and in combination, significantly increased soil MBC while decreasing bacterial diversity. However, increases in soil MBC were inhibited when N addition exceeded 60 kg N•ha‑1•yr‑1. IM increased the relative abundances of Actinobacteria and Crenarchaeota but decreased that of Acidobacteria. N addition increased the relative abundances of Acidobacteria, Crenarchaeota, and Actinobacteria but decreased that of Proteobacteria. Soil bacterial diversity was significantly related to soil pH, C/N ratio, and nitrogen and available phosphorus content. Management practices exerted a greater influence over regulation of the soil MBC and microbial diversity compared to that of N deposition in Moso bamboo plantations.

  19. Nitrogen deposition and management practices increase soil microbial biomass carbon but decrease diversity in Moso bamboo plantations

    PubMed Central

    Li, Quan; Song, Xinzhang; Gu, Honghao; Gao, Fei

    2016-01-01

    Because microbial communities play a key role in carbon (C) and nitrogen (N) cycling, changes in the soil microbial community may directly affect ecosystem functioning. However, the effects of N deposition and management practices on soil microbes are still poorly understood. We studied the effects of these two factors on soil microbial biomass carbon (MBC) and community composition in Moso bamboo plantations using high-throughput sequencing of the 16S rRNA gene. Plantations under conventional (CM) or intensive management (IM) were subjected to one of four N treatments for 30 months. IM and N addition, both separately and in combination, significantly increased soil MBC while decreasing bacterial diversity. However, increases in soil MBC were inhibited when N addition exceeded 60 kg N∙ha−1∙yr−1. IM increased the relative abundances of Actinobacteria and Crenarchaeota but decreased that of Acidobacteria. N addition increased the relative abundances of Acidobacteria, Crenarchaeota, and Actinobacteria but decreased that of Proteobacteria. Soil bacterial diversity was significantly related to soil pH, C/N ratio, and nitrogen and available phosphorus content. Management practices exerted a greater influence over regulation of the soil MBC and microbial diversity compared to that of N deposition in Moso bamboo plantations. PMID:27302857

  20. Nitrogen deposition and management practices increase soil microbial biomass carbon but decrease diversity in Moso bamboo plantations.

    PubMed

    Li, Quan; Song, Xinzhang; Gu, Honghao; Gao, Fei

    2016-01-01

    Because microbial communities play a key role in carbon (C) and nitrogen (N) cycling, changes in the soil microbial community may directly affect ecosystem functioning. However, the effects of N deposition and management practices on soil microbes are still poorly understood. We studied the effects of these two factors on soil microbial biomass carbon (MBC) and community composition in Moso bamboo plantations using high-throughput sequencing of the 16S rRNA gene. Plantations under conventional (CM) or intensive management (IM) were subjected to one of four N treatments for 30 months. IM and N addition, both separately and in combination, significantly increased soil MBC while decreasing bacterial diversity. However, increases in soil MBC were inhibited when N addition exceeded 60 kg N∙ha(-1)∙yr(-1). IM increased the relative abundances of Actinobacteria and Crenarchaeota but decreased that of Acidobacteria. N addition increased the relative abundances of Acidobacteria, Crenarchaeota, and Actinobacteria but decreased that of Proteobacteria. Soil bacterial diversity was significantly related to soil pH, C/N ratio, and nitrogen and available phosphorus content. Management practices exerted a greater influence over regulation of the soil MBC and microbial diversity compared to that of N deposition in Moso bamboo plantations. PMID:27302857

  1. Ecosystem engineering by invasive exotic beavers reduces in-stream diversity and enhances ecosystem function in Cape Horn, Chile.

    PubMed

    Anderson, Christopher B; Rosemond, Amy D

    2007-11-01

    Species invasions are of global significance, but predicting their impacts can be difficult. Introduced ecosystem engineers, however, provide an opportunity to test the underlying mechanisms that may be common to all invasive engineers and link relationships between changes in diversity and ecosystem function, thereby providing explanatory power for observed ecological patterns. Here we test specific predictions for an invasive ecosystem engineer by quantifying the impacts of habitat and resource modifications caused by North American beavers (Castor canadensis) on aquatic macroinvertebrate community structure and stream ecosystem function in the Cape Horn Biosphere Reserve, Chile. We compared responses to beavers in three habitat types: (1) forested (unimpacted) stream reaches, (2) beaver ponds, and (3) sites immediately downstream of beaver dams in four streams. We found that beaver engineering in ponds created taxonomically simplified, but more productive, benthic macroinvertebrate assemblages. Specifically, macroinvertebrate richness, diversity and number of functional feeding groups were reduced by half, while abundance, biomass and secondary production increased three- to fivefold in beaver ponds compared to forested sites. Reaches downstream of beaver ponds were very similar to natural forested sections. Beaver invasion effects on both community and ecosystem parameters occurred predominantly via increased retention of fine particulate organic matter, which was associated with reduced macroinvertebrate richness and diversity (via homogenization of benthic microhabitat) and increased macroinvertebrate biomass and production (via greater food availability). Beaver modifications to macroinvertebrate community structure were largely confined to ponds, but increased benthic production in beaver-modified habitats adds to energy retention and flow for the entire stream ecosystem. Furthermore, the effects of beavers on taxa richness (negative) and measures of

  2. Plant invasions differentially affected by diversity and dominant species in native- and exotic-dominated grasslands.

    PubMed

    Xu, Xia; Polley, H Wayne; Hofmockel, Kirsten; Daneshgar, Pedram P; Wilsey, Brian J

    2015-12-01

    Plant invasions are an increasingly serious global concern, especially as the climate changes. Here, we explored how plant invasions differed between native- and novel exotic-dominated grasslands with experimental addition of summer precipitation in Texas in 2009. Exotic species greened up earlier than natives by an average of 18 days. This was associated with a lower invasion rate early in the growing season compared to native communities. However, invasion rate did not differ significantly between native and exotic communities across all sampling times. The predictors of invasion rate differed between native and exotic communities, with invasion being negatively influenced by species richness in natives and by dominant species in exotics. Interestingly, plant invasions matched the bimodal pattern of precipitation in Temple, Texas, and did not respond to the pulse of precipitation during the summer. Our results suggest that we will need to take different approaches in understanding of invasion between native and exotic grasslands. Moreover, with anticipated increasing variability in precipitation under global climate change, plant invasions may be constrained in their response if the precipitation pulses fall outside the normal growing period of invaders. PMID:27069615

  3. Benthic community responses to macroalgae invasions in seagrass beds: Diversity, isotopic niche and food web structure at community level

    NASA Astrophysics Data System (ADS)

    Deudero, S.; Box, A.; Vázquez-Luis, M.; Arroyo, N. L.

    2014-04-01

    Trophic paths between species are a useful tool for analysing the impact of species invasions of a biotic community. Species invasions produce changes at trophic level and diversity shifts by replacing native species with species of similar ecological niche. This study focused on the effects of macroalgal invasions on seagrass ecosystems. We conducted two - year bimonthly sampling of a pristine Posidonia oceanica seagrass meadow and dead matte colonized by three Caulerpa species bimonthly. The largest changes in faunal composition were found in meadows colonized by Caulerpa prolifera, where major differences in infaunal taxonomic distinctness were apparent. On the other hand, the infaunal community was quite similar between the two invasive Caulerpa species (Caulerpa taxifolia and Caulerpa racemosa). The isotopic niche based on the main trophic guilds established using stable isotope signatures at community level resulted in a highly compacted and 15N-enriched C. prolifera food web structure, indicating high overlap of food source utilization among faunal components, which is typical of degraded systems. Conversely, the P. oceanica ecosystem presented the most complex food web, while the influence of the 2 invasive species were similar. An attempt to reconstruct the food web at each vegetated habitat revealed high trophic linkages among the different trophic levels with a continuous transition among them by the various trophic guilds suggesting an adaptation response of the different organisms to the new habitat forming species.

  4. Decreased microbial diversity and Lactobacillus group in the intestine of geriatric giant pandas (Ailuropoda melanoleuca).

    PubMed

    Peng, Zhirong; Zeng, Dong; Wang, Qiang; Niu, Lili; Ni, Xueqin; Zou, Fuqin; Yang, Mingyue; Sun, Hao; Zhou, Yi; Liu, Qian; Yin, Zhongqiong; Pan, Kangcheng; Jing, Bo

    2016-05-01

    It has been established beyond doubt that giant panda genome lacks lignin-degrading related enzyme, gastrointestinal microbes may play a vital role in digestion of highly fibrous bamboo diet. However, there is not much information available about the intestinal bacteria composition in captive giant pandas with different ages. In this study, we compared the intestinal bacterial community of 12 captive giant pandas from three different age groups (subadults, adults, and geriatrics) through PCR-denaturing gradient gel electrophoresis (DGGE) and real-time PCR analysis. Results indicated that microbial diversity in the intestine of adults was significantly higher than that of the geriatrics (p < 0.05), but not significant compared to the subadults (p > 0.05). The predominant bands in DGGE patterns shared by the twelve pandas were related to Firmicutes and Proteobacteria. Additionally, in comparison to healthy individuals, antibiotic-treated animals showed partial microbial dysbiosis. Real-time PCR analyses confirmed a significantly higher abundance of the Lactobacillus in the fecal microbiota of adults (p < 0.05), while other bacterial groups and species detected did not significantly differ among the three age groups (p > 0.05). This study revealed that captive giant pandas with different ages showed different intestinal bacteria composition. PMID:27038949

  5. Overexpression of dnIKK in mesenchymal stem cells leads to increased migration and decreased invasion upon TNFα stimulation.

    PubMed

    Haasters, Florian; Prall, Wolf Christian; Westphal, Ines; Böcker, Wolfgang; Padula, Daniela; Mutschler, Wolf; Docheva, Denitsa; Schieker, Matthias

    2013-06-28

    IκB kinase 2 (IKK-2) mediates tumor necrosis-factor α (TNFα) induced invasion of human mesenchymal stem cell (hMSC) to sites of tissue injury. Suppressing IKK-2 activity leads to reduced expression of proteolytic enzymes and impaired invasive capacity. In order to further reveal mechanisms of hMSC recruitment, we here aimed to analyse the impact of IKK-2 on two-dimensional migration upon TNFα stimulation in contrast to three-dimensional invasion. An immortalized hMSC line (SCP-1) was transduced with a dominant-negative mutant of IκB kinase 2 (SCP-1 dnIKK). Migration was assessed using a linear-gradient chemotaxis chambers by time-lapse analysis. Invasive capacity through human extracellular matrix was analysed using transwell invasion assays. RT-PCR confirmed increased IKK-2 expression levels in SCP-1 dnIKK cells, while TNFα receptor I and II expression was not altered. Invasion upon TNFα stimulation was significantly reduced by 78% in SCP-1 dnIKK. In contrast, migration was significantly increased, represented by a 60% elevated forward migration index and a 2.1-fold higher mean dislocation of the center of mass towards TNFα. In conclusion, our data confirms the impact of IKK-2 in TNFα dependent hMSC recruitment. Interestingly, reducing IKK-2 function increases two-dimensional migration towards TNFα, while invasive capacity is impaired. These findings contribute to a deeper understanding of MSC's biological properties orchestrating the complex processes of stem cell recruitment and homing. PMID:23743204

  6. Decreased Nucleotide and Expression Diversity and Modified Coexpression Patterns Characterize Domestication in the Common Bean[W][OPEN

    PubMed Central

    Bellucci, Elisa; Bitocchi, Elena; Ferrarini, Alberto; Benazzo, Andrea; Biagetti, Eleonora; Klie, Sebastian; Minio, Andrea; Rau, Domenico; Rodriguez, Monica; Panziera, Alex; Venturini, Luca; Attene, Giovanna; Albertini, Emidio; Jackson, Scott A.; Nanni, Laura; Fernie, Alisdair R.; Nikoloski, Zoran; Bertorelle, Giorgio; Delledonne, Massimo; Papa, Roberto

    2014-01-01

    Using RNA sequencing technology and de novo transcriptome assembly, we compared representative sets of wild and domesticated accessions of common bean (Phaseolus vulgaris) from Mesoamerica. RNA was extracted at the first true-leaf stage, and de novo assembly was used to develop a reference transcriptome; the final data set consists of ∼190,000 single nucleotide polymorphisms from 27,243 contigs in expressed genomic regions. A drastic reduction in nucleotide diversity (∼60%) is evident for the domesticated form, compared with the wild form, and almost 50% of the contigs that are polymorphic were brought to fixation by domestication. In parallel, the effects of domestication decreased the diversity of gene expression (18%). While the coexpression networks for the wild and domesticated accessions demonstrate similar seminal network properties, they show distinct community structures that are enriched for different molecular functions. After simulating the demographic dynamics during domestication, we found that 9% of the genes were actively selected during domestication. We also show that selection induced a further reduction in the diversity of gene expression (26%) and was associated with 5-fold enrichment of differentially expressed genes. While there is substantial evidence of positive selection associated with domestication, in a few cases, this selection has increased the nucleotide diversity in the domesticated pool at target loci associated with abiotic stress responses, flowering time, and morphology. PMID:24850850

  7. Evaluation of Eukaryotic Cell Invasion on a Library of Genetically Diverse Campylobacter spp. Isolates.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Campylobacter spp. are the largest cause of sporadic bacterial gastrointestinal infection in the industrialized world. Epithelial cell invasion is thought to be necessary to bring about infection in humans. Invasion studies have shown that different Campylobacter jejuni isolates may differ in thei...

  8. 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...

  9. Inhibition of adhesion of enteroinvasive pathogens to human intestinal Caco-2 cells by Lactobacillus acidophilus strain LB decreases bacterial invasion.

    PubMed

    Coconnier, M H; Bernet, M F; Kernéis, S; Chauvière, G; Fourniat, J; Servin, A L

    1993-07-01

    Salmonella typhimurium and enteropathogenic Escherichia coli (EPEC) were found to adhere to the brush border of differentiated human intestinal epithelial Caco-2 cells in culture, whereas Yersinia pseudotuberculosis and Listeria monocytogenes adhered to the periphery of undifferentiated Caco-2 cells. All these enterovirulent strains invaded the Caco-2 cells. Using a heat-killed human Lactobacillus acidophilus (strain LB) which strongly adheres both to undifferentiated and differentiated Caco-2 cells, we have studied inhibition of cell association with and invasion within Caco-2 cells by enterovirulent bacteria. Living and heat-killed Lactobacillus acidophilus strain LB inhibited both cell association and invasion of Caco-2 cells by enterovirulent bacteria in a concentration-dependent manner. The mechanism of inhibition of both adhesion and invasion appears to be due to steric hindrance of human enterocytic pathogen receptors by whole-cell lactobacilli rather than to a specific blockade of receptors. PMID:8354463

  10. French invasive Asian tiger mosquito populations harbor reduced bacterial microbiota and genetic diversity compared to Vietnamese autochthonous relatives

    PubMed Central

    Minard, G.; Tran, F. H.; Van, Van Tran; Goubert, C.; Bellet, C.; Lambert, G.; Kim, Khanh Ly Huynh; Thuy, Trang Huynh Thi; Mavingui, P.; Valiente Moro, C.

    2015-01-01

    The Asian tiger mosquito Aedes albopictus is one of the most significant pathogen vectors of the twenty-first century. Originating from Asia, it has invaded a wide range of eco-climatic regions worldwide. The insect-associated microbiota is now recognized to play a significant role in host biology. While genetic diversity bottlenecks are known to result from biological invasions, the resulting shifts in host-associated microbiota diversity has not been thoroughly investigated. To address this subject, we compared four autochthonous Ae. albopictus populations in Vietnam, the native area of Ae. albopictus, and three populations recently introduced to Metropolitan France, with the aim of documenting whether these populations display differences in host genotype and bacterial microbiota. Population-level genetic diversity (microsatellite markers and COI haplotype) and bacterial diversity (16S rDNA metabarcoding) were compared between field-caught mosquitoes. Bacterial microbiota from the whole insect bodies were largely dominated by Wolbachia pipientis. Targeted analysis of the gut microbiota revealed a greater bacterial diversity in which a fraction was common between French and Vietnamese populations. The genus Dysgonomonas was the most prevalent and abundant across all studied populations. Overall genetic diversities of both hosts and bacterial microbiota were significantly reduced in recently established populations of France compared to the autochthonous populations of Vietnam. These results open up many important avenues of investigation in order to link the process of geographical invasion to shifts in commensal and symbiotic microbiome communities, as such shifts may have dramatic impacts on the biology and/or vector competence of invading hematophagous insects. PMID:26441903

  11. Homologous prime boosting based on intranasal delivery of non-pathogenic invasive Escherichia coli expressing MPT64, decreases Mycobacterium tuberculosis dissemination.

    PubMed

    Sali, Michela; Dainese, Elisa; Morandi, Matteo; Zumbo, Antonella; Rocca, Stefano; Goussard, Sylvie; Palù, Giorgio; Grillot-Courvalin, Catherine; Delogu, Giovanni; Manganelli, Riccardo

    2014-07-01

    Protein-subunit vaccines as boosting strategies against tuberculosis (TB) infection are currently in the pipeline of TB vaccine research. Their main limitation is represented by their poor immunogenicity, which makes it necessary to couple protein-subunits with adjuvant molecules. In this study, we employed replication-deficient invasive Escherichia coli strains to deliver Mycobacterium tuberculosis proteins to the cytoplasm of non-phagocytic eukaryotic cells using various priming and prime-boosting vaccination protocols. Our results demonstrate that intranasal administration of invasive E. coli expressing the M. tuberculosis protective antigen MPT64 to mice primed with a recombinant BCG strain over-expressing MPT64 on its surface, decrease bacterial burden in mice spleens. Our data suggest that replication-deficient invasive E. coli may represent a suitable platform for BCG/rBCG priming followed by homologous-boosting immunization strategies. PMID:24886957

  12. Rhamnus cathartica (Rosales: Rhamnaceae) Invasion Reduces Ground-Dwelling Insect Abundance and Diversity in Northeast Iowa Forests.

    PubMed

    Schuh, Marissa; Larsen, Kirk J

    2015-06-01

    European buckthorn (Rhamnus cathartica L.) is an invasive woody shrub in deciduous forests of the Upper Midwest. Studies have suggested buckthorn invasion has negative effects on native plants, soil, and ecosystems, but its impacts on insects are largely unstudied. To test the impact of buckthorn invasion on ground-dwelling insects in forests of northeastern Iowa, pitfall traps were used to sample ground-dwelling insects at five sites four different periods from June to August 2013. Each site had three treatments: areas heavily infested with buckthorn, areas where buckthorn has not established, and areas where buckthorn had been removed within the past 2-10 yr. Most insects were identified to family and quantified; while ground beetles (Coleoptera: Carabidae) and ants (Hymenoptera: Formicidae) were identified to species and quantified. In total, 11,576 insects representing eight orders and 46 families were collected. Areas uninvaded by buckthorn had significantly greater insect abundance and taxonomic richness than areas invaded by buckthorn. Of the 948 ground beetles representing 40 species, abundance, species richness, and Shannon diversity indices were significantly lower in areas invaded by buckthorn compared with areas with no buckthorn. The 2,661 ants from 24 species had similar trends, but treatment differences were not significant because of high variability. These results clearly show a negative impact of buckthorn invasion on the abundance and taxonomic richness of ground-dwelling insects. PMID:26313971

  13. Plant Invasions Associated with Change in Root-Zone Microbial Community Structure and Diversity.

    PubMed

    Rodrigues, Richard R; Pineda, Rosana P; Barney, Jacob N; Nilsen, Erik T; Barrett, John E; Williams, Mark A

    2015-01-01

    The importance of plant-microbe associations for the invasion of plant species have not been often tested under field conditions. The research sought to determine patterns of change in microbial communities associated with the establishment of invasive plants with different taxonomic and phenetic traits. Three independent locations in Virginia, USA were selected. One site was invaded by a grass (Microstegium vimineum), another by a shrub (Rhamnus davurica), and the third by a tree (Ailanthus altissima). The native vegetation from these sites was used as reference. 16S rRNA and ITS regions were sequenced to study root-zone bacterial and fungal communities, respectively, in invaded and non-invaded samples and analyzed using Quantitative Insights Into Microbial Ecology (QIIME). Though root-zone microbial community structure initially differed across locations, plant invasion shifted communities in similar ways. Indicator species analysis revealed that Operational Taxonomic Units (OTUs) closely related to Proteobacteria, Acidobacteria, Actinobacteria, and Ascomycota increased in abundance due to plant invasions. The Hyphomonadaceae family in the Rhodobacterales order and ammonia-oxidizing Nitrospirae phylum showed greater relative abundance in the invaded root-zone soils. Hyphomicrobiaceae, another bacterial family within the phyla Proteobacteria increased as a result of plant invasion, but the effect associated most strongly with root-zones of M. vimineum and R. davurica. Functional analysis using Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt) showed bacteria responsible for nitrogen cycling in soil increased in relative abundance in association with plant invasion. In agreement with phylogenetic and functional analyses, greater turnover of ammonium and nitrate was associated with plant invasion. Overall, bacterial and fungal communities changed congruently across plant invaders, and support the hypothesis that nitrogen

  14. Plant Invasions Associated with Change in Root-Zone Microbial Community Structure and Diversity

    PubMed Central

    Rodrigues, Richard R.; Pineda, Rosana P.; Barney, Jacob N.; Nilsen, Erik T.; Barrett, John E.; Williams, Mark A.

    2015-01-01

    The importance of plant-microbe associations for the invasion of plant species have not been often tested under field conditions. The research sought to determine patterns of change in microbial communities associated with the establishment of invasive plants with different taxonomic and phenetic traits. Three independent locations in Virginia, USA were selected. One site was invaded by a grass (Microstegium vimineum), another by a shrub (Rhamnus davurica), and the third by a tree (Ailanthus altissima). The native vegetation from these sites was used as reference. 16S rRNA and ITS regions were sequenced to study root-zone bacterial and fungal communities, respectively, in invaded and non-invaded samples and analyzed using Quantitative Insights Into Microbial Ecology (QIIME). Though root-zone microbial community structure initially differed across locations, plant invasion shifted communities in similar ways. Indicator species analysis revealed that Operational Taxonomic Units (OTUs) closely related to Proteobacteria, Acidobacteria, Actinobacteria, and Ascomycota increased in abundance due to plant invasions. The Hyphomonadaceae family in the Rhodobacterales order and ammonia-oxidizing Nitrospirae phylum showed greater relative abundance in the invaded root-zone soils. Hyphomicrobiaceae, another bacterial family within the phyla Proteobacteria increased as a result of plant invasion, but the effect associated most strongly with root-zones of M. vimineum and R. davurica. Functional analysis using Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt) showed bacteria responsible for nitrogen cycling in soil increased in relative abundance in association with plant invasion. In agreement with phylogenetic and functional analyses, greater turnover of ammonium and nitrate was associated with plant invasion. Overall, bacterial and fungal communities changed congruently across plant invaders, and support the hypothesis that nitrogen

  15. Shared genetic diversity across the global invasive range of the monk parakeet suggests a common restricted geographic origin and the possibility of convergent selection.

    PubMed

    Edelaar, Pim; Roques, Severine; Hobson, Elizabeth A; Gonçalves da Silva, Anders; Avery, Michael L; Russello, Michael A; Senar, Juan C; Wright, Timothy F; Carrete, Martina; Tella, José L

    2015-05-01

    While genetic diversity is hypothesized to be an important factor explaining invasion success, there is no consensus yet on how variation in source populations or demographic processes affects invasiveness. We used mitochondrial DNA haplotypic and microsatellite genotypic data to investigate levels of genetic variation and reconstruct the history of replicate invasions on three continents in a globally invasive bird, the monk parakeet (Myiopsitta monachus). We evaluated whether genetic diversity at invasive sites could be explained by (i) the native source populations from which they were derived and (ii) demographic bottlenecks during introduction. Genetic data indicated a localized source area for most sampled invasive populations, with limited evidence for admixing of native source populations. This pattern largely coincides with historical data on pet trade exports. However, the invasive populations are genetically more similar than predicted from the export data alone. The extent of bottleneck effects varied among invasive populations. The observed low genetic diversity, evidence of demographic contraction and restricted source area do not support the hypothesis that invasion is favoured by the mixing and recombining of genetic variation from multiple source populations. Instead, they suggest that reduced genetic variation through random processes may not inhibit successful establishment and invasion in this species. However, convergent selection across invasive sites could also explain the observed patterns of reduction and similarity in genetic variation and/or the restricted source area. In general, the alternative explanation of intraspecific variation in invasive potential among genotypes or geographic areas is neglected, but warrants more attention as it could inform comparative studies and management of biological invaders. PMID:25873354

  16. Invasion of Ligustrum lucidum (Oleaceae) in the southern Yungas: Changes in habitat properties and decline in bird diversity

    NASA Astrophysics Data System (ADS)

    Ayup, M. M.; Montti, L.; Aragón, R.; Grau, H. R.

    2014-01-01

    Ligustrum lucidum is the major exotic tree in NW Argentina montane forests (Yungas). To assess the effects of its expanding invasion on avian communities we (1) measured different habitat properties (vertical forest structure and composition, vegetation cover, light availability, air temperature, air relative humidity and soil litter depth), (2) compared bird species composition and diversity in Ligustrum-dominated and native-dominated secondary forests and (3) analyzed seasonal patterns and changes in these variables between forest types. The study was conducted during 2010-2011 wet and dry seasons, at two altitudinal zones: 500-800 and 1100-1450 masl. Compared with native forests, Ligustrum dominated forests had a more homogeneous vertical forest structure and denser canopy cover (resulting in lower understory solar radiation), significantly lower understory cover and lower litter depth. Air temperature and relative humidity did not differ between forests in either season. Solar radiation was higher in the dry season in both forest types, but litter depth showed opposite patterns between seasons depending on forest type. We recorded 59 bird species in 21 families. Bird species abundance, richness and diversity indexes were significantly lower in Ligustrum-dominated relative to native forests of similar successional age, which had almost twice as many species as the former. Avian communities differed between altitudinal zones, but the difference was stronger between Ligustrum and native-dominated forests. Avian community composition was less variable in time and space in native forests than in Ligustrum-dominated ones. Our results suggest that L. lucidum invasion generates structurally homogeneous and simpler forests that represent a less suitable habitat for a diverse avifauna. This illustrates the wide ecological changes (from habitat properties and ecosystem functioning to vertebrate community composition) that the subtropical mountain forests of Argentina are

  17. Inhibition of microRNA-21 decreases the invasiveness of fibroblast-like synoviocytes in rheumatoid arthritis via TGFβ/Smads signaling pathway

    PubMed Central

    Xiong, Gaoxin; Huang, Zhang; Jiang, Hua; Pan, Zhengjun; Xie, Jie; Wang, Shuangli

    2016-01-01

    Objective(s): MicroRNA-21 (miR21) is aberrantly elevated in rheumatoid arthritis (RA) patients, the significance of this microRNA in RA pathogenesis and treatment, however, has not been investigated. In this study, by using RA-derived fibroblast-like synoviocyte (FLS) cells as a model, we investigated the effect and corresponding mechanism of miR21 inhibition on FLSs invasion. Materials and Methods: miR21 expression in synovial tissue and FLSs in RA patients and non-RA controls were determined by stem-loop RT-PCR. The effect of miR21 on FLSs viability and invasiveness were evaluated using miR21 inhibition. Cell viability was evaluated by MTT assay and the expression of genes at mRNA and protein levels was determined by RT-PCR and Western blot, respectively. Results: Our results showed that miR21 expression was highly increased in synovial tissue and FLSs in RA patients. Also, we reported that miR21 inhibitor treatment could significantly suppress the invasiveness of FLSs without affecting cell viability. The decreased FLSs invasion by miR21 inhibition was associated with down-regulated expression of matrix metalloproteinase (MMP)-1, MMP3, and MMP13. Further analysis revealed that miR21 inhibition could suppress the expression of TGFβ1 and Smad4, but promote that of Smad7. Moreover, suppression of FLS invasion and MMPs expression by miR21 treatment could be counteracted by additional TGFβ1 treatment. Conclusion: Our results indicated that miR21 inhibition can down-regulate the expression of MMP1, MMP3, and MMP13 and consequently suppress the invasiveness of FLS, which is achieved through TGFβ1/Smad4/7 signaling pathway. The findings of this study could offer a novel approach for RA treatment.

  18. 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

  19. Recombinant nematode anticoagulant protein c2 inhibits cell invasion by decreasing uPA expression in NSCLC cells.

    PubMed

    Tong, Yu; Yue, Jun; Mao, Meng; Liu, Qingqing; Zhou, Jing; Yang, Jiyun

    2015-04-01

    Nematode anticoagulant protein c2 (NAPc2) is an 85-residue polypeptide originally isolated from the hematophagous hookworm, Ancylostoma caninum. Several studies have shown that rNAPc2 inhibits the growth of primary and metastatic tumors in mice independently of its ability to initiate coagulation. We obtained bioactive recombinant rNAPc2 by splicing of the rNAPc2-intein-CBD fusion proteins expressed in E. coli ER2566. In the in vitro assay, rNAPc2 obviously inhibited the invasive ability of non-small cell lung cancer (NSCLC) cells in a dose-dependent manner. Furthermore, rNAPc2 suppressed tumor growth in vivo by daily intraperitoneal injection of rNAPc2 in an NSCLC cell xenograft model of nude mice. Respectively, rNAPc2 downregulated the production of urokinase plasminogen activator (uPA) (P<0.05) and suppressed nuclear factor-κB (NF-κB) activity. We also identified that inhibition of NF-κB activity impaired cell invasion and reduced the uPA production in NSCLC cells. Meanwhile, NF-κB was found to directly bind to the uPA promoter in vitro. These results demonstrated that rNAPc2 inhibits cell invasion at least in part through the downregulation of the NF-κB-dependent metastasis-related gene expression in NSCLC. Our results also suggest that uPA, a known metastasis-promoting gene, is indirectly regulated by rNAPc2 through NF-κB activation. These results indicate that rNAPc2 may be a potent agent for the prevention of NSCLC progression. PMID:25672417

  20. Forest species diversity reduces disease risk in a generalist plant pathogen invasion

    USGS Publications Warehouse

    Haas, Sarah E.; Hooten, Mevin B.; Rizzo, David M.; Meentemeyer, Ross K.

    2011-01-01

    Empirical evidence suggests that biodiversity loss can increase disease transmission, yet our understanding of the 'diversity-disease hypothesis' for generalist pathogens in natural ecosystems is limited. We used a landscape epidemiological approach to examine two scenarios regarding diversity effects on the emerging plant pathogen Phytophthora ramorum across a broad, heterogeneous ecoregion: (1) an amplification effect exists where disease risk is greater in areas with higher plant diversity due to the pathogen's wide host range, or (2) a dilution effect where risk is reduced with increasing diversity due to lower competency of alternative hosts. We found evidence for pathogen dilution, whereby disease risk was lower in sites with higher species diversity, after accounting for potentially confounding effects of host density and landscape heterogeneity. Our results suggest that although nearly all plants in the ecosystem are hosts, alternative hosts may dilute disease transmission by competent hosts, thereby buffering forest health from infectious disease.

  1. Non-thermal plasma inhibits human cervical cancer HeLa cells invasiveness by suppressing the MAPK pathway and decreasing matrix metalloproteinase-9 expression

    PubMed Central

    Li, Wei; Yu, K. N.; Bao, Lingzhi; Shen, Jie; Cheng, Cheng; Han, Wei

    2016-01-01

    Non-thermal plasma (NTP) has been proposed as a novel therapeutic method for anticancer treatment. However, the mechanism underlying its biological effects remains unclear. In this study, we investigated the inhibitory effect of NTP on the invasion of HeLa cells, and explored the possible mechanism. Our results showed that NTP exposure for 20 or 40 s significantly suppressed the migration and invasion of HeLa cells on the basis of matrigel invasion assay and wound healing assay, respectively. Moreover, NTP reduced the activity and protein expression of the matrix metalloproteinase (MMP)-9 enzyme. Western blot analysis indicated that NTP exposure effectively decreased phosphorylation level of both ERK1/2 and JNK, but not p38 MAPK. Furthermore, treatment with MAPK signal pathway inhibitors or NTP all exhibited significant depression of HeLa cells migration and MMP-9 expression. The result showed that NTP synergistically suppressed migration and MMP-9 expression in the presence of ERK1/2 inhibitor and JNK inhibitor, but not p38 MAPK inhibitor. Taken together, these findings suggested that NTP exposure inhibited the migration and invasion of HeLa cells via down-regulating MMP-9 expression in ERK1/2 and JNK signaling pathways dependent manner. These findings provide hints to the potential clinical research and therapy of NTP on cervical cancer metastasis. PMID:26818472

  2. Non-thermal plasma inhibits human cervical cancer HeLa cells invasiveness by suppressing the MAPK pathway and decreasing matrix metalloproteinase-9 expression

    NASA Astrophysics Data System (ADS)

    Li, Wei; Yu, K. N.; Bao, Lingzhi; Shen, Jie; Cheng, Cheng; Han, Wei

    2016-01-01

    Non-thermal plasma (NTP) has been proposed as a novel therapeutic method for anticancer treatment. However, the mechanism underlying its biological effects remains unclear. In this study, we investigated the inhibitory effect of NTP on the invasion of HeLa cells, and explored the possible mechanism. Our results showed that NTP exposure for 20 or 40 s significantly suppressed the migration and invasion of HeLa cells on the basis of matrigel invasion assay and wound healing assay, respectively. Moreover, NTP reduced the activity and protein expression of the matrix metalloproteinase (MMP)-9 enzyme. Western blot analysis indicated that NTP exposure effectively decreased phosphorylation level of both ERK1/2 and JNK, but not p38 MAPK. Furthermore, treatment with MAPK signal pathway inhibitors or NTP all exhibited significant depression of HeLa cells migration and MMP-9 expression. The result showed that NTP synergistically suppressed migration and MMP-9 expression in the presence of ERK1/2 inhibitor and JNK inhibitor, but not p38 MAPK inhibitor. Taken together, these findings suggested that NTP exposure inhibited the migration and invasion of HeLa cells via down-regulating MMP-9 expression in ERK1/2 and JNK signaling pathways dependent manner. These findings provide hints to the potential clinical research and therapy of NTP on cervical cancer metastasis.

  3. Decreasing Abundance, Increasing Diversity and Changing Structure of the Wild Bee Community (Hymenoptera: Anthophila) along an Urbanization Gradient

    PubMed Central

    Fortel, Laura; Henry, Mickaël; Guilbaud, Laurent; Guirao, Anne Laure; Kuhlmann, Michael; Mouret, Hugues; Rollin, Orianne; Vaissière, Bernard E.

    2014-01-01

    Background Wild bees are important pollinators that have declined in diversity and abundance during the last decades. Habitat destruction and fragmentation associated with urbanization are reported as part of the main causes of this decline. Urbanization involves dramatic changes of the landscape, increasing the proportion of impervious surface while decreasing that of green areas. Few studies have investigated the effects of urbanization on bee communities. We assessed changes in the abundance, species richness, and composition of wild bee community along an urbanization gradient. Methodology/Principal Findings Over two years and on a monthly basis, bees were sampled with colored pan traps and insect nets at 24 sites located along an urbanization gradient. Landscape structure within three different radii was measured at each study site. We captured 291 wild bee species. The abundance of wild bees was negatively correlated with the proportion of impervious surface, while species richness reached a maximum at an intermediate (50%) proportion of impervious surface. The structure of the community changed along the urbanization gradient with more parasitic species in sites with an intermediate proportion of impervious surface. There were also greater numbers of cavity-nesting species and long-tongued species in sites with intermediate or higher proportion of impervious surface. However, urbanization had no effect on the occurrence of species depending on their social behavior or body size. Conclusions/Significance We found nearly a third of the wild bee fauna known from France in our study sites. Indeed, urban areas supported a diverse bee community, but sites with an intermediate level of urbanization were the most speciose ones, including greater proportion of parasitic species. The presence of a diverse array of bee species even in the most urbanized area makes these pollinators worthy of being a flagship group to raise the awareness of urban citizens about

  4. Phylogenetic investigation of the genus Raoiella (Prostigmata: Tenuipalpidae): Diversity, distribution, and world invasions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The genus Raoiella is most well known because of the red palm mite, R. indica, a major pest of palms spreading aggressively throughout the Americas. Not much was known about the biology, geographic origins, or evolutionary history of the genus when R. indica emerged as a major invasive pest. This pa...

  5. Invasive stink bug favors naïve plants: Testing the role of plant geographic origin in diverse, managed environments

    PubMed Central

    Martinson, Holly M.; Bergmann, Erik J.; Venugopal, P. Dilip; Riley, Christopher B.; Shrewsbury, Paula M.; Raupp, Michael J.

    2016-01-01

    With the introduction and establishment of exotic species, most ecosystems now contain both native and exotic plants and herbivores. Recent research identifies several factors that govern how specialist herbivores switch host plants upon introduction. Predicting the feeding ecology and impacts of introduced generalist species, however, remains difficult. Here, we examine how plant geographic origin, an indicator of shared co-evolutionary history, influences patterns of host use by a generalist, invasive herbivore, while accounting for variation in plant availability. The brown marmorated stink bug, Halyomorpha halys, is a highly polyphagous Asian herbivore and an economically important invasive pest in North America and Europe. In visual surveys of 220 plant taxa in commercial nurseries in Maryland, USA, H. halys was more abundant on non-Asian plants and selected these over Asian plants. The relationship between the relative use of plants and their availability was strongly positive but depended also on plant origin at two of our three sites, where the higher relative use of non-Asian plants was greatest for highly abundant taxa. These results highlight the importance of considering both plant origin and relative abundance in understanding the selection of host plants by invasive generalist herbivores in diverse, natural and urban forests. PMID:27581756

  6. Invasive stink bug favors naïve plants: Testing the role of plant geographic origin in diverse, managed environments.

    PubMed

    Martinson, Holly M; Bergmann, Erik J; Venugopal, P Dilip; Riley, Christopher B; Shrewsbury, Paula M; Raupp, Michael J

    2016-01-01

    With the introduction and establishment of exotic species, most ecosystems now contain both native and exotic plants and herbivores. Recent research identifies several factors that govern how specialist herbivores switch host plants upon introduction. Predicting the feeding ecology and impacts of introduced generalist species, however, remains difficult. Here, we examine how plant geographic origin, an indicator of shared co-evolutionary history, influences patterns of host use by a generalist, invasive herbivore, while accounting for variation in plant availability. The brown marmorated stink bug, Halyomorpha halys, is a highly polyphagous Asian herbivore and an economically important invasive pest in North America and Europe. In visual surveys of 220 plant taxa in commercial nurseries in Maryland, USA, H. halys was more abundant on non-Asian plants and selected these over Asian plants. The relationship between the relative use of plants and their availability was strongly positive but depended also on plant origin at two of our three sites, where the higher relative use of non-Asian plants was greatest for highly abundant taxa. These results highlight the importance of considering both plant origin and relative abundance in understanding the selection of host plants by invasive generalist herbivores in diverse, natural and urban forests. PMID:27581756

  7. Genomic Recombination Leading to Decreased Virulence of Group B Streptococcus in a Mouse Model of Adult Invasive Disease.

    PubMed

    Teatero, Sarah; Lemire, Paul; Dewar, Ken; Wasserscheid, Jessica; Calzas, Cynthia; Mallo, Gustavo V; Li, Aimin; Athey, Taryn B T; Segura, Mariela; Fittipaldi, Nahuel

    2016-01-01

    Adult invasive disease caused by Group B Streptococcus (GBS) is increasing worldwide. Whole-genome sequencing (WGS) now permits rapid identification of recombination events, a phenomenon that occurs frequently in GBS. Using WGS, we described that strain NGBS375, a capsular serotype V GBS isolate of sequence type (ST)297, has an ST1 genomic background but has acquired approximately 300 kbp of genetic material likely from an ST17 strain. Here, we examined the virulence of this strain in an in vivo model of GBS adult invasive infection. The mosaic ST297 strain showed intermediate virulence, causing significantly less systemic infection and reduced mortality than a more virulent, serotype V ST1 isolate. Bacteremia induced by the ST297 strain was similar to that induced by a serotype III ST17 strain, which was the least virulent under the conditions tested. Yet, under normalized bacteremia levels, the in vivo intrinsic capacity to induce the production of pro-inflammatory cytokines was similar between the ST297 strain and the virulent ST1 strain. Thus, the diminished virulence of the mosaic strain may be due to reduced capacity to disseminate or multiply in blood during a systemic infection which could be mediated by regulatory factors contained in the recombined region. PMID:27527222

  8. EphA2 silencing in nasopharyngeal carcinoma leads to decreased proliferation, invasion and increased sensitization to paclitaxel.

    PubMed

    Tan, Pingqing; Liu, Yong; Yu, Changyun; Su, Zhongwu; Li, Guo; Zhou, Xiaojuan; Huang, Donghai; Zhang, Xin; Qiu, Yuanzheng; Tian, Yongquan

    2012-09-01

    EphA2 is frequently overexpressed and functionally altered in a variety of human cancers. However, its roles in human nasopharyngeal carcinoma (NPC) remain unclear. To investigate the roles of EphA2 in the development and progression of NPC, we initially evaluated the expression pattern of EphA2 protein in NPC tissues using western blotting and CCK-8 assay. Fluorescence-activated cell sorting analysis and invasion assay were conducted to observe the effects of EphA2 inhibition in vivo. Our results demonstrated that EphA2 was overexpressed in NPC specimens and the expression of EphA2 was significantly associated with T classification, advanced clinical stage and lymph node metastasis. Moreover, human NPC 5-8F cells were infected with lentiviral vector-mediated EphA2-specific shRNA, which resulted in the significant inhibition of cell growth, invasion of 5-8F cells and markedly enhanced the sensitivity of 5-8F cells to the chemotherapeutic agent paclitaxel in vitro. Collectively, our results demonstrate that EphA2 is involved in malignant cell behavior and is a potential therapeutic target in human NPC. PMID:23741245

  9. Decreased expression of miR-378 correlates with tumor invasiveness and poor prognosis of patients with glioma

    PubMed Central

    Li, Bing; Wang, Yilin; Li, Shiting; He, Hua; Sun, Fengbin; Wang, Chunlin; Lu, Yicheng; Wang, Xiaoqiang; Tao, Bangbao

    2015-01-01

    microRNAs (miRNAs) are a class of small non-coding RNAs that play important roles in a variety of biological process. It has been reported that dysregulation of miRNA is always associated with cancer progression and development, and miR-378 aberrant expression has been found in some types of cancers. However, the association of miR-378 and glioma has not been evaluated. In this work, we measured the expression of miR-378 in glioma tissues and non-neoplastic brain tissues was measured using real-time PCR, and found that miRNA-378 expression level was significantly lower in glioma tissues compared with non-neoplastic brain tissues. Patients with lower miR-378 expression level had significantly poorer overall survival. Multivariate Cox regression analysis showed that miR-378 expression was an independent prognostic factor for 5-year overall survival. Over-expression of miR-378 inhibits glioma cell migration and invasion. In conclusion, our results indicated that miR-378 may serve as a tumor suppressor and play an important role in inhibiting tumor migration and invasion. Our work implicates the potential effect of miR-378 on the prognosis of glioma. PMID:26261592

  10. Diversity and trans-arctic invasion history of mitochondrial lineages in the North Atlantic Macoma balthica complex (Bivalvia: Tellinidae).

    PubMed

    Nikula, Raisa; Strelkov, Petr; Väinölä, Risto

    2007-04-01

    The history of repeated inter- or transoceanic invasions in bivalve mollusks of the circumpolar Macoma balthica complex was assessed from mtDNA COIII sequences. The data suggest that four independent trans-Arctic invasions, from the Pacific, gave rise to the current lineage diversity in the North Atlantic. Unlike in many other prominent North Atlantic littoral taxa, no evidence for (postinvasion) trans-Atlantic connections was found in the M. balthica complex. The earliest branch of the mtDNA tree is represented by the temperate-boreal North American populations (=Macoma petalum), separated from the M. balthica complex proper in the Early Pliocene at latest. The ensuing trans-Arctic invasions established the North European M. b. rubra, which now prevails on the North Sea and northeast Atlantic coasts, about two million years ago, and the currently northwest Atlantic M. balthica lineage in the Canadian Maritimes, in the Middle Pleistocene. The final reinvasion(s) introduced a lineage that now prevails in a number of North European marginal seas and is still hardly distinguishable from North Pacific mtDNA (M. b. balthica). We used coalescence simulation analyses to assess the age of the latest invasion from the Pacific to the northeast Atlantic. The results refute the hypothesis of recent, human-mediated reintroductions between northeast Pacific and the North European marginal seas in historical times. Yet they also poorly fit the alternative hypotheses of an early postglacial trans-Arctic invasion (< 11 thousand years ago), or an invasion during the previous Eemian interglacial (120 thousand years ago). Divergence time estimates rather fall in the Middle Weichselian before the Last Glacial Maximum, in conflict with the conventional thinking of trans-Arctic biogeographical connections; an early Holocene reinvasion may still be regarded as the most plausible scenario. Today, the most recently invaded Pacific mtDNA lineage is found admixed with the earlier established

  11. Indigenous and Invasive Fruit Fly Diversity along an Altitudinal Transect in Eastern Central Tanzania

    PubMed Central

    Geurts, Katrien; Mwatawala, Maulid; De Meyer, Marc

    2012-01-01

    The relative abundance of indigenous and invasive frugivorous fruit flies (Diptera: Tephritidae) was evaluated spatially and temporally along an altitudinal transect between 581–1650 m in the Uluguru Mountains near Morogoro, Tanzania. The polyphagous invasive fruit fly Bactrocera invadens Drew, Tsuruta, and White and the indigenous fruit fly Ceratitis rosa Karsch show a similar temporal pattern, but are largely separated spatially, with B. invadens being abundant at lower elevation and C. rosa predominant at higher elevation. The polyphagous indigenous C. cosyra (Walker) coincides with B. invadens but shows an inverse temporal pattern. The cucurbit feeders B. cucurbitae (Coquillett) and Dacus bivittatus (Bigot) show a similar temporal pattern, but the former is restricted to lower elevations. Host availability and climatic differences seem to be the determining factors to explain the differences in occurrence and abundance in time and space. PMID:22935017

  12. Prolactin receptor attenuation induces zinc pool redistribution through ZnT2 and decreases invasion in MDA-MB-453 breast cancer cells

    SciTech Connect

    Bostanci, Zeynep; Alam, Samina; Soybel, David I.; Kelleher, Shannon L.

    2014-02-15

    Prolactin receptor (PRL-R) activation regulates cell differentiation, proliferation, cell survival and motility of breast cells. Prolactin (PRL) and PRL-R over-expression are strongly implicated in breast cancer, particularly contributing to tumor growth and invasion in the more aggressive estrogen-receptor negative (ER−) disease. PRL-R antagonists have been suggested as potential therapeutic agents; however, mechanisms through which PRL-R antagonists exert their actions are not well-understood. Zinc (Zn) is a regulatory factor for over 10% of the proteome, regulating critical cell processes such as proliferation, cell signaling, transcription, apoptosis and autophagy. PRL-R signaling regulates Zn metabolism in breast cells. Herein we determined effects of PRL-R attenuation on cellular Zn metabolism and cell function in a model of ER-, PRL-R over-expressing breast cancer cells (MDA-MB-453). PRL-R attenuation post-transcriptionally increased ZnT2 abundance and redistributed intracellular Zn pools into lysosomes and mitochondria. ZnT2-mediated lysosomal Zn sequestration was associated with reduced matrix metalloproteinase 2 (MMP-2) activity and decreased invasion. ZnT2-mediated Zn accumulation in mitochondria was associated with increased mitochondrial oxidation. Our results suggest that PRL-R antagonism in PRL-R over-expressing breast cancer cells may reduce invasion through the redistribution of intracellular Zn pools critical for cellular function. - Highlights: • PRL-R attenuation increased ZnT2 expression. • PRL-R attenuation increased lysosomal and mitochondrial Zn accumulation. • PRL-R attenuation decreased MMP-2 and invasion. • PRL-R antagonists may modulate lysosomal and mitochondrial Zn pools.

  13. Map2k4 Functions as a Tumor Suppressor in Lung Adenocarcinoma and Inhibits Tumor Cell Invasion by Decreasing Peroxisome Proliferator-Activated Receptor γ2 Expression ▿

    PubMed Central

    Ahn, Young-Ho; Yang, Yanan; Gibbons, Don L.; Creighton, Chad J.; Yang, Fei; Wistuba, Ignacio I.; Lin, Wei; Thilaganathan, Nishan; Alvarez, Cristina A.; Roybal, Jonathon; Goldsmith, Elizabeth J.; Tournier, Cathy; Kurie, Jonathan M.

    2011-01-01

    MAP2K4 encodes a dual-specificity kinase (mitogen-activated protein kinase kinase 4, or MKK4) that is mutated in a variety of human malignancies, but the biochemical properties of the mutant kinases and their roles in tumorigenesis have not been fully elucidated. Here we showed that 8 out of 11 cancer-associated MAP2K4 mutations reduce MKK4 protein stability or impair its kinase activity. On the basis of findings from bioinformatic studies on human cancer cell lines with homozygous MAP2K4 loss, we posited that MKK4 functions as a tumor suppressor in lung adenocarcinomas that develop in mice owing to expression of mutant Kras and Tp53. Conditional Map2k4 inactivation in the bronchial epithelium of mice had no discernible effect alone but increased the multiplicity and accelerated the growth of incipient lung neoplasias induced by oncogenic Kras. MKK4 suppressed the invasion and metastasis of Kras-Tp53-mutant lung adenocarcinoma cells. MKK4 deficiency increased peroxisomal proliferator-activated receptor γ2 (PPARγ2) expression through noncanonical MKK4 substrates, and PPARγ2 enhanced tumor cell invasion. We conclude that Map2k4 functions as a tumor suppressor in lung adenocarcinoma and inhibits tumor cell invasion by decreasing PPARγ2 levels. PMID:21896780

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

    PubMed Central

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

    2016-01-01

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

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

    PubMed

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

    2016-01-01

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

  16. The extent of hybridization and its impact on the genetic diversity and population structure of an invasive tree, Ulmus pumila (Ulmaceae)

    PubMed Central

    Zalapa, Juan E; Brunet, Johanne; Guries, Raymond P

    2010-01-01

    Ulmus pumila is considered an invasive tree in 41 of the United States. In this study, we examined the extent of hybridization in naturalized populations of U. pumila, its impact on genetic diversity and genetic structure and its potential role in explaining the invasion process of U. pumila. Genetic analyses indicated widespread hybridization with native Ulmus rubra in naturalized U. pumila populations. Hybridization increased the genetic diversity of U. pumila populations and affected their genetic structure. The level of genetic diversity in ‘mature’ accessions, many of which may represent original plantings throughout the USA, was high and similar to the diversity of East Asian accessions. Hybridization with the native red elm may play an important role in the success of Siberian elm as an invader in temperate regions of the USA. PMID:25567916

  17. Patterns of mitochondrial haplotype diversity in the invasive pest Epiphyas postvittana (Lepidoptera: Tortricidae).

    PubMed

    Tooman, Leah K; Rose, Caroline J; Carraher, Colm; Suckling, D Max; Paquette, Sébastien Rioux; Ledezma, Lisa A; Gilligan, Todd M; Epstein, Marc; Barr, Norman B; Newcomb, Richard D

    2011-06-01

    The light brown apple moth, Epiphyas postvittana (Walker) (Lepidoptera: Tortricidae), is a horticultural pest of Australia and New Zealand that has more recently invaded Hawaii, Europe, and California. A 2,216-bp region of the mitochondrial genome containing the cytochrome oxidase I and II genes was sequenced from 752 individuals. Haplotype network analyses revealed a major split between a predominantly Western Australian clade and all other samples, suggestive of either a deep genetic divergence or a cryptic species. Nucleotide and haplotype diversity were highest in the country of origin, Australia, and in New Zealand populations, with evidence of haplotype sharing between New Zealand and Tasmania. Nucleotide and haplotype diversity were higher in California than within the British Isles or Hawaii. From the total of 96 haplotypes, seven were found in California, of which four were private. Within California, there have been at least two introductions; based on genetic diversity we were unable to assign a likely source for a single moth found and eradicated in Los Angeles in 2007; however, our data suggest it is unlikely that Hawaii and the British Isles are sources of the major E. postvittana population found throughout the rest of the state since 2006. PMID:21735912

  18. AB209630, a long non-coding RNA decreased expression in hypopharyngeal squamous cell carcinoma, influences proliferation, invasion, metastasis, and survival

    PubMed Central

    Li, Wenming; Wang, Juan; Xiang, Xuan; Li, Guojun; Pan, Xinliang; Lei, Dapeng

    2016-01-01

    Long noncoding RNAs (lncRNAs) are associated with the development, progression, and prognosis of human cancers. However, the clinical significance and biological function of lncRNAs in hypopharyngeal squamous cell carcinoma (HSCC) remain largely unknown. We characterized the novel lncRNA AB209630 in vivo and in vitro. First, using qRT-PCR, we evaluated whether AB209630 levels differ between HSCC tissues/cell lines and adjacent normal tissues/cell lines. We then assessed whether AB209630 expression levels stimulate or inhibit proliferation, invasion, apoptosis, and metastasis in vitro. Finally, we investigated whether AB209630 levels in tumor tissues were associated with survival outcomes. Our results demonstrated that AB209630 levels were markedly lower in HSCC tissues and cells than in normal tissues and cells, and increased expression of AB209630 level significantly inhibited growth, metastasis, and invasion and stimulated apoptosis in vitro. In addition, patients with decreased expression of AB209630 had a significantly poorer prognosis than those with high AB209630 expression. These data suggest that increased expression of AB209630 might either stimulate or inhibit biological activities involved in HSCC development, indicating a potential application of AB209630 in future treatment for this disease. This study suggest that AB209630 functions as a tumor suppressor in HSCC, and its decreased expression may help predict a poor prognostic outcome of HSCC. Our future work will focus on the mechanisms of whether and how AB209630 as a tumor suppressor gene is involved in HSCC development. PMID:26895099

  19. Phylogenetic investigation of the genus Raoiella (Prostigmata: Tenuipalpidae): diversity, distribution, and world invasions.

    PubMed

    Dowling, A P G; Ochoa, R; Beard, J J; Welbourn, W C; Ueckermann, E A

    2012-08-01

    The genus Raoiella is best known because of the red palm mite, R. indica, a major pest of palms spreading aggressively throughout the Americas. Not much was known about the biology, geographic origins, or evolutionary history of the genus when R. indica emerged as a major invasive pest. This paper attempts to address some of the basic historical questions regarding the palm mite as well as the genus. Molecular characters from COI and 28S regions were used to produce a phylogenetic hypothesis for the genus in an effort to understand its geographic origin. It also uses COI barcode data to delimit several potentially new species discovered by the authors in Australia. Results show a basal split between R. indica and all other Raoiella species, which indicates Africa or the Middle East as the most probable origin of the genus. Additionally, COI data suggests that at least eight new species are represented among the 20 Australian populations included in this study. PMID:21913003

  20. European Invasion of North American Pinus strobus at Large and Fine Scales: High Genetic Diversity and Fine-Scale Genetic Clustering over Time in the Adventive Range

    PubMed Central

    Mandák, Bohumil; Hadincová, Věroslava; Mahelka, Václav; Wildová, Radka

    2013-01-01

    Background North American Pinus strobus is a highly invasive tree species in Central Europe. Using ten polymorphic microsatellite loci we compared various aspects of the large-scale genetic diversity of individuals from 30 sites in the native distribution range with those from 30 sites in the European adventive distribution range. To investigate the ascertained pattern of genetic diversity of this intercontinental comparison further, we surveyed fine-scale genetic diversity patterns and changes over time within four highly invasive populations in the adventive range. Results Our data show that at the large scale the genetic diversity found within the relatively small adventive range in Central Europe, surprisingly, equals the diversity found within the sampled area in the native range, which is about thirty times larger. Bayesian assignment grouped individuals into two genetic clusters separating North American native populations from the European, non-native populations, without any strong genetic structure shown over either range. In the case of the fine scale, our comparison of genetic diversity parameters among the localities and age classes yielded no evidence of genetic diversity increase over time. We found that SGS differed across age classes within the populations under study. Old trees in general completely lacked any SGS, which increased over time and reached its maximum in the sapling stage. Conclusions Based on (1) the absence of difference in genetic diversity between the native and adventive ranges, together with the lack of structure in the native range, and (2) the lack of any evidence of any temporal increase in genetic diversity at four highly invasive populations in the adventive range, we conclude that population amalgamation probably first happened in the native range, prior to introduction. In such case, there would have been no need for multiple introductions from previously isolated populations, but only several introductions from

  1. Resting-state networks link invasive and noninvasive brain stimulation across diverse psychiatric and neurological diseases.

    PubMed

    Fox, Michael D; Buckner, Randy L; Liu, Hesheng; Chakravarty, M Mallar; Lozano, Andres M; Pascual-Leone, Alvaro

    2014-10-14

    Brain stimulation, a therapy increasingly used for neurological and psychiatric disease, traditionally is divided into invasive approaches, such as deep brain stimulation (DBS), and noninvasive approaches, such as transcranial magnetic stimulation. The relationship between these approaches is unknown, therapeutic mechanisms remain unclear, and the ideal stimulation site for a given technique is often ambiguous, limiting optimization of the stimulation and its application in further disorders. In this article, we identify diseases treated with both types of stimulation, list the stimulation sites thought to be most effective in each disease, and test the hypothesis that these sites are different nodes within the same brain network as defined by resting-state functional-connectivity MRI. Sites where DBS was effective were functionally connected to sites where noninvasive brain stimulation was effective across diseases including depression, Parkinson's disease, obsessive-compulsive disorder, essential tremor, addiction, pain, minimally conscious states, and Alzheimer's disease. A lack of functional connectivity identified sites where stimulation was ineffective, and the sign of the correlation related to whether excitatory or inhibitory noninvasive stimulation was found clinically effective. These results suggest that resting-state functional connectivity may be useful for translating therapy between stimulation modalities, optimizing treatment, and identifying new stimulation targets. More broadly, this work supports a network perspective toward understanding and treating neuropsychiatric disease, highlighting the therapeutic potential of targeted brain network modulation. PMID:25267639

  2. Resting-state networks link invasive and noninvasive brain stimulation across diverse psychiatric and neurological diseases

    PubMed Central

    Fox, Michael D.; Buckner, Randy L.; Liu, Hesheng; Chakravarty, M. Mallar; Lozano, Andres M.; Pascual-Leone, Alvaro

    2014-01-01

    Brain stimulation, a therapy increasingly used for neurological and psychiatric disease, traditionally is divided into invasive approaches, such as deep brain stimulation (DBS), and noninvasive approaches, such as transcranial magnetic stimulation. The relationship between these approaches is unknown, therapeutic mechanisms remain unclear, and the ideal stimulation site for a given technique is often ambiguous, limiting optimization of the stimulation and its application in further disorders. In this article, we identify diseases treated with both types of stimulation, list the stimulation sites thought to be most effective in each disease, and test the hypothesis that these sites are different nodes within the same brain network as defined by resting-state functional-connectivity MRI. Sites where DBS was effective were functionally connected to sites where noninvasive brain stimulation was effective across diseases including depression, Parkinson's disease, obsessive-compulsive disorder, essential tremor, addiction, pain, minimally conscious states, and Alzheimer’s disease. A lack of functional connectivity identified sites where stimulation was ineffective, and the sign of the correlation related to whether excitatory or inhibitory noninvasive stimulation was found clinically effective. These results suggest that resting-state functional connectivity may be useful for translating therapy between stimulation modalities, optimizing treatment, and identifying new stimulation targets. More broadly, this work supports a network perspective toward understanding and treating neuropsychiatric disease, highlighting the therapeutic potential of targeted brain network modulation. PMID:25267639

  3. Magnetofection based on superparamagnetic iron oxide nanoparticle-mediated low lncRNA HOTAIR expression decreases the proliferation and invasion of glioma stem cells.

    PubMed

    Fang, Kan; Liu, Peifeng; Dong, Suyan; Guo, Yanjie; Cui, Xinxin; Zhu, Xiaoying; Li, Xuan; Jiang, Lianghan; Liu, Te; Wu, Yuncheng

    2016-08-01

    Glioma stem cells (GSCs) are a special subpopulation of glioma cells that are key to the sensitivity of tumors to treatments and to the possibility of tumor recurrence. Identifying new strategies that inhibit the growth of GSCs are therefore important for developing novel therapies for glioblastoma multiforme (GBM). In this study, CD133+ human glioma stem cells were isolated and cultured. Magnetic nanoparticles were used to mediate the expression of siRNAs targeting the HOTAIR (si-HOTAIR) sequence in human gliomas. Effect of downregulation of HOTAIR expression on proliferation, invasion and in vivo tumorigenicity of human GSCs and underlying molecular mechanisms were further evaluated. The results of the MTT assay and flow cytometric analysis showed that downregulation of HOTAIR expression inhibited cell proliferation and induced cell cycle arrest. Transwell assays demonstrated that downregulation of HOTAIR expression resulted in a decrease in the invasive capability of GSCs. Moreover, magnetic nanoparticle-mediated low expression of HOTAIR effectively reduced the tumorigenic capacity of glioma stem cells in vivo. In addition, the results of qRT-PCR and western blot analysis demonstrated that downregulation of HOTAIR expression significantly increased the expression of PDCD4 in GSCs, in addition to reducing the expression of CCND1 and CDK4. An in-depth mechanistic analysis showed that downregulation of HOTAIR expression reduced the recruitment of downstream molecules, EZH2 and LSD1, thereby activating the expression of PDCD4 at the transcriptional level. In conclusion, downregulation of HOTAIR expression effectively promoted the expression of PDCD4, thereby inhibiting the proliferation, invasion and in vivo tumorigenicity of human GSCs. PMID:27277755

  4. Magnetofection based on superparamagnetic iron oxide nanoparticle-mediated low lncRNA HOTAIR expression decreases the proliferation and invasion of glioma stem cells

    PubMed Central

    Fang, Kan; Liu, Peifeng; Dong, Suyan; Guo, Yanjie; Cui, Xinxin; Zhu, Xiaoying; Li, Xuan; Jiang, Lianghan; Liu, Te; Wu, Yuncheng

    2016-01-01

    Glioma stem cells (GSCs) are a special subpopulation of glioma cells that are key to the sensitivity of tumors to treatments and to the possibility of tumor recurrence. Identifying new strategies that inhibit the growth of GSCs are therefore important for developing novel therapies for glioblastoma multiforme (GBM). In this study, CD133+ human glioma stem cells were isolated and cultured. Magnetic nanoparticles were used to mediate the expression of siRNAs targeting the HOTAIR (si-HOTAIR) sequence in human gliomas. Effect of downregulation of HOTAIR expression on proliferation, invasion and in vivo tumorigenicity of human GSCs and underlying molecular mechanisms were further evaluated. The results of the MTT assay and flow cytometric analysis showed that downregulation of HOTAIR expression inhibited cell proliferation and induced cell cycle arrest. Transwell assays demonstrated that downregulation of HOTAIR expression resulted in a decrease in the invasive capability of GSCs. Moreover, magnetic nanoparticle-mediated low expression of HOTAIR effectively reduced the tumorigenic capacity of glioma stem cells in vivo. In addition, the results of qRT-PCR and western blot analysis demonstrated that downregulation of HOTAIR expression significantly increased the expression of PDCD4 in GSCs, in addition to reducing the expression of CCND1 and CDK4. An in-depth mechanistic analysis showed that downregulation of HOTAIR expression reduced the recruitment of downstream molecules, EZH2 and LSD1, thereby activating the expression of PDCD4 at the transcriptional level. In conclusion, downregulation of HOTAIR expression effectively promoted the expression of PDCD4, thereby inhibiting the proliferation, invasion and in vivo tumorigenicity of human GSCs. PMID:27277755

  5. Serum Glutamate Levels Correlate with Gleason Score and Glutamate Blockade Decreases Proliferation, Migration, and Invasion and Induces Apoptosis in Prostate Cancer Cells

    PubMed Central

    Koochekpour, Shahriar; Majumdar, Sunipa; Azabdaftari, Gissou; Attwood, Kristopher; Scioneaux, Ray; Subramani, Dhatchayini; Manhardt, Charles; Lorusso, Giovanni D.; Willard, Stacey S.; Thompson, Hillary; Shourideh, Mojgan; Rezaei, Katayoon; Sartor, Oliver; Mohler, James L.; Vessella, Robert L.

    2012-01-01

    Purpose During glutaminolysis, glutamine is catabolized to glutamate and incorporated into citric acid cycle and lipogenesis. Serum glutamate levels were measured in patients with primary prostate cancer (PCa) or metastatic castrate-resistant PCa (mCRPCa) to establish clinical relevance. The effect of glutamate-deprivation or blockade by metabotropic glutamate receptor 1 (GRM1)-antagonists was investigated on PCa cells’ growth, migration, and invasion to establish biological relevance. Experimental Design Serum glutamate levels were measured in normal men (n = 60) and patients with primary PCa (n = 197) or mCRPCa (n = 109). GRM1 expression in prostatic tissues was examined using immunohistochemistry (IHC). Cell growth, migration, and invasion were determined using cell cytotoxicity and modified Boyden chamber assays, respectively. Apoptosis was detected using immunoblotting against cleaved caspases, PARP and γ-H2AX. Results Univariate and multivariate analyses demonstrated significantly higher serum glutamate levels in Gleason score ≥ 8 than in the Gleason sscore ≤ 7 and in African Americans than in the Caucasian Americans. African Americans with mCRPCa significantly higher serum glutamate levels than those with primary PCa or benign prostate. However, in Caucasian Americans, serum glutamate levels were similar in normal research subjects and patients with mCRPC. IHC demonstrated weak or no expression of GRM1 in luminal acinar epithelial cells of normal or hyperplastic glands, but high expression in primary or metastatic PCa tissues. Glutamate deprivation or blockade decreased PCa cells’ proliferation, migration, and invasion and led to apoptotic cell death. Conclusions Glutamate expression is mechanistically associated with and may provide a biomarker of PCa aggressiveness. PMID:23072969

  6. Distribution and Diversity of hmw1A Among Invasive Nontypeable Haemophilus influenzae Isolates in Iran

    PubMed Central

    Shahini Shams Abadi, Milad; Siadat, Seyed Davar; Vaziri, Farzam; Davari, Mehdi; Fateh, Abolfazl; Pourazar, Shahin; Abdolrahimi, Farid; Ghazanfari, Morteza

    2016-01-01

    Background: The pathogenesis of nontypeable Haemophilus influenzae (NTHi) begins with adhesion to the rhinopharyngeal mucosa. Almost 38–80% of NTHi clinical isolates produce proteins that belong to the High Molecular Weight (HMW) family of adhesins, which are believed to facilitate colonization. Methods: In the present study, the prevalence of hmwA, which encodes the HMW adhesin, was determined for a collection of 32 NTHi isolates. Restriction Fragment Length Polymorphism (RFLP) was performed to advance our understanding of hmwA binding sequence diversity. Results: The results demonstrated that hmwA was detected in 61% of NTHi isolates. According to RFLP, isolates were divided into three groups. Conclusion: Based on these observations, it is hypothesized that some strains of nontypeable Haemophilus influenzae infect some specific areas more than other parts. PMID:27141269

  7. Tannin-rich pomegranate rind extracts reduce adhesion to and invasion of Caco-2 Cells by Listeria monocytogenes and decrease its expression of virulence genes.

    PubMed

    Xu, Yunfeng; Li, Guanghui; Zhang, Baigang; Wu, Qian; Wang, Xin; Xia, Xiaodong

    2015-01-01

    Pomegranate rind is rich in tannins that have remarkable antimicrobial activities. This study aimed to evaluate the effects of a tannin-rich fraction from pomegranate rind (TFPR) on Listeria monocytogenes virulence gene expression and on the pathogen's interaction with human epithelial cells. Growth curves were monitored to determine the effect of TFPR on L. monocytogenes growth. The 3-(4,5-dimethylthiazol-2-yl)2,5-diphenyltetrazolium bromide and fluorescence staining assays were used to examine the cytotoxicity of TFPR. The effects of TFPR on L. monocytogenes adhesion to and invasion of epithelial cells were investigated using Caco-2 cells. Real-time quantitative PCR analysis was conducted to quantify mRNA levels of three virulence genes in L. monocytogenes. Results showed that a MIC of TFPR against L. monocytogenes was 5 mg/ml in this study. TFPR exhibited cytotoxicity against Caco-2 cells when the concentration was 2.5 mg/ml. Subinhibitory concentrations of TFPR significantly reduced, in a dose-dependent manner, adhesion to and invasion of Caco-2 cells by L. monocytogenes. When L. monocytogenes was grown in the presence of 2.5 mg/ml TFPR, the transcriptional levels of prfA, inlA, and hly decreased by 17-, 34-, and 28-fold, respectively. PMID:25581187

  8. Genetic diversity in a morphologically conservative invasive taxon: Multiple introductions of swamp eels to the southeastern United States

    USGS Publications Warehouse

    Collins, T.M.; Trexler, J.C.; Nico, L.G.; Rawlings, T.A.

    2002-01-01

    Genetic analysis of introduced populations, especially in morphologically conservative taxa, can clarify introduction histories, identify management units and source populations, provide a more realistic estimate of the frequency of successful invasion, and suggest strategies for preventing further introductions. In the last 7 years, populations of swamp eels, referred to the Asian genus Monopterus (Family Synbranchidae) on the basis of external morphology, have been discovered in aquatic habitats near Atlanta, Georgia; Tampa, Florida; North Miami, Florida; and most recently in close proximity to Everglades National Park in Homestead, Florida. Swamp eels are large predators capable of dispersal over land and have the potential to disrupt already threatened ecosystems. We analyzed mitochondrial DNA sequences from four known populations in the continental United States and samples from Malaysia, Indonesia, Vietnam, and two locations in China to determine introduction histories, source populations, genetic diversity, and relationships among populations. Our results indicate that there have been at least three independent introductions of genetically distinct forms. Introduced populations in close proximity (separated by <40 km) are genetically distinct. The level of sequence difference among introduced populations reaches levels seen among sister families of teleost fishes for the same region of the mitochondrial genome. These genetically distinct introduced populations in all likelihood represent at least two and possibly three species. Regardless of species status, these genetically distinct lineages may be expected to vary in ecological or life-history traits, representing different potential threats to the ecosystems where they have been introduced. Given the success of swamp eels in invading many habitats around the world, further study of these eels is warranted to elucidate the characteristics of successful invaders and invasions.

  9. Biological Warfare in Invasive Plants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Alliaria petiolata (garlic mustard) is an invasive species in temperate forests throughout North America that has led to a decrease in species diversity and alterations in nutrient cycling. Garlic mustard produces an arsenal of secondary chemicals in the glucosinolate family that have strong biocid...

  10. Loss of phytotelmata due to an invasive bromeliad-eating weevil and its potential effects on faunal diversity and biogeochemical cycles

    NASA Astrophysics Data System (ADS)

    Cooper, Teresa M.; Frank, J. Howard; Cave, Ronald D.

    2014-01-01

    Epiphytic tank bromeliads are important ecosystem engineers because they form phytotelmata that create habitat, increase species richness and abundance, create water sources and nutrient reservoirs in the canopy, and collect and redirect nutrients in forest ecosystems. Native bromeliad populations have been devastated in Florida (USA) because an invasive bromeliad-eating weevil (Metamasius callizona) has been destroying the plants. Tillandsia utriculata is a tank bromeliad that was once widespread from central to south Florida. Its populations have been hit hard by the weevil and are declining rapidly. This study quantifies the mortality rate caused by the weevil in a population of T. utriculata at the Enchanted Forest Sanctuary in central Florida and estimates the associated loss of phytotelmata. Estimations of phytotelmata were calculated for the T. utriculata baseline population, the population at 6 months into the study when 87% of the population was destroyed, and at the end of the study when less than 3% of the bromeliad population remained (99% of all deaths were caused by the weevil). The baseline population contained 16,758 L of water. At six months, there were 3180 L, and at the end of the study, there were 408 L. The loss of phytotelmata results in the loss of habitat, a decrease in biological diversity, and altered water and nutrient cycles and availability.

  11. Invasion genetics of the Bermuda buttercup (Oxalis pes-caprae): complex intercontinental patterns of genetic diversity, polyploidy and heterostyly characterize both native and introduced populations.

    PubMed

    Ferrero, Victoria; Barrett, Spencer C H; Castro, Sílvia; Caldeirinha, Patrícia; Navarro, Luis; Loureiro, João; Rodríguez-Echeverría, Susana

    2015-05-01

    Genetic diversity in populations of invasive species is influenced by a variety of factors including reproductive systems, ploidy level, stochastic forces associated with colonization and multiple introductions followed by admixture. Here, we compare genetic variation in native and introduced populations of the clonal plant Oxalis pes-caprae to investigate the influence of reproductive mode and ploidy on levels of diversity. This species is a tristylous geophyte native to South Africa. Invasive populations throughout much of the introduced range are composed of a sterile clonal pentaploid short-styled form. We examined morph ratios, ploidy level, reproductive mode and genetic diversity at nuclear microsatellite loci in 10 and 12 populations from South Africa and the Western Mediterranean region, respectively. Flow cytometry confirmed earlier reports of diploids and tetraploids in the native range, with a single population containing pentaploid individuals. Introduced populations were composed mainly of pentaploids, but sexual tetraploids were also found. There was clear genetic differentiation between ploidy levels, but sexual populations from both regions were not significantly different in levels of diversity. Invasive populations of the pentaploid exhibited dramatically reduced levels of diversity but were not genetically uniform. The occurrence of mixed ploidy levels and stylar polymorphism in the introduced range is consistent with multiple introductions to the Western Mediterranean. This inference was supported by variation patterns at microsatellite loci. Our study indicates that some invasive populations of Oxalis pes-caprae are not entirely clonal, as often assumed, and multiple introductions and recombination have the potential to increase genetic variation in the introduced range. PMID:25604701

  12. Plasma miR-185 is decreased in patients with esophageal squamous cell carcinoma and might suppress tumor migration and invasion by targeting RAGE.

    PubMed

    Jing, Rongrong; Chen, Wen; Wang, Huimin; Ju, Shaoqing; Cong, Hui; Sun, Baolan; Jin, Qin; Chu, Shaopeng; Xu, Lili; Cui, Ming

    2015-11-01

    The receptor for advanced-glycation end products (RAGE) is upregulated in various cancers and has been associated with tumor progression, but little is known about its expression and regulation by microRNAs (miRNAs) in esophageal squamous cell carcinoma (ESCC). Here, we describe miR-185, which represses RAGE expression, and investigate the biological role of miR-185 in ESCC. In this study, we found that the high level of RAGE expression in 29 pairs of paraffin-embedded ESCC tissues was correlated positively with the depth of invasion by immunohistochemistry, suggesting that RAGE was involved in ESCC. We used bioinformatics searches and luciferase reporter assays to investigate the prediction that RAGE was regulated directly by miR-185. Besides, overexpression of miR-185 in ESCC cells was accompanied by 27% (TE-11) and 49% (Eca-109) reduced RAGE expression. The effect was further confirmed in RAGE protein by immunofluorescence in both cell lines. The effects were reversed following cotransfection with miR-185 and high-level expression of the RAGE vector. Furthermore, the biological role of miR-185 in ESCC cell lines was investigated using assays of cell viability, Ki-67 staining, and cell migration and invasion, as well as in a xenograft model. We found that overexpression of miR-185 inhibited migration and invasion by ESCC cells in vitro and reduced their capacity to develop distal pulmonary metastases in vivo partly through the RAGE/heat shock protein 27 pathway. Interestingly, in clinical specimens, the level of plasma miR-185 expression was decreased significantly (P = 0.002) in patients with ESCC [0.500; 95% confidence interval (CI) 0.248-1.676] compared with healthy controls (2.410; 95% CI 0.612-5.671). The value of the area under the receiver-operating characteristic curve was 0.73 (95% CI 0.604-0.855). In conclusion, our findings shed novel light on the role of miR-185/RAGE in ESCC metastasis, and plasma miR-185 has potential as a novel diagnostic biomarker

  13. Placenta-Enriched LincRNAs MIR503HG and LINC00629 Decrease Migration and Invasion Potential of JEG-3 Cell Line

    PubMed Central

    Muys, Bruna Rodrigues; Lorenzi, Júlio Cesar Cetrulo; Zanette, Dalila Luciola; Bueno, Rafaela de Barros Lima e; de Araújo, Luíza Ferreira; Dinarte-Santos, Anemari Ramos; Alves, Cleidson Pádua; Ramão, Anelisa; de Molfetta, Greice Andreotti; Vidal, Daniel Onofre; Silva, Wilson Araújo

    2016-01-01

    LINC00629 and MIR503HG are long intergenic non-coding RNAs (lincRNAs) mapped on chromosome X (Xq26), a region enriched for genes associated with human reproduction. Genes highly expressed in normal reproductive tissues and cancers (CT genes) are well known as potential tumor biomarkers. This study aimed to characterize the structure, expression, function and regulation mechanism of MIR503HG and LINC00629 lincRNAs. According to our data, MIR503HG expression was almost exclusive to placenta and LINC00629 was highly expressed in placenta and other reproductive tissues. Further analysis, using a cancer cell lines panel, showed that MIR503HG and LINC00629 were expressed in 50% and 100% of the cancer cell lines, respectively. MIR503HG was expressed predominantly in the nucleus of JEG-3 choriocarcinoma cells. We observed a positively correlated expression between MIR503HG and LINC00629, and between the lincRNAs and neighboring miRNAs. Also, both LINC00629 and MIR503GH could be negatively regulated by DNA methylation in an indirect way. Additionally, we identified new transcripts for MIR503HG and LINC00629 that are relatively conserved when compared to other primates. Furthermore, we found that overexpression of MIR503HG2 and the three-exon LINC00629 new isoforms decreased invasion and migration potential of JEG-3 tumor cell line. In conclusion, our results suggest that lincRNAs MIR503HG and LINC00629 impaired migration and invasion capacities in a choriocarcinoma in vitro model, indicating a potential role in human reproduction and tumorigenesis. Moreover, the MIR503HG expression pattern found here could indicate a putative new tumor biomarker. PMID:27023770

  14. Invasive and Noninvasive Streptococcus pneumoniae Capsule and Surface Protein Diversity following the Use of a Conjugate Vaccine

    PubMed Central

    Croney, Christina M.; Nahm, Moon H.; Juhn, Steven K.; Briles, David E.

    2013-01-01

    The 13-valent pneumococcal conjugate vaccine (PCV13) was introduced in the United States in 2010 for the prevention of invasive pneumococcal disease (IPD) and otitis media. While many studies have reported its potential efficacy for IPD, not much is known about the epidemiology of noninvasive disease following its introduction. We characterized the capsular types and surface protein genes of noninvasive pediatric pneumococcal isolates collected between 2002 and 2010 (n = 1,058) at Children's of Alabama following the introduction of PCV7 and tested a subset of noninvasive and previously characterized IPD isolates for the presence of the pspA, pspC, and rrgC genes, which encode protection-eliciting proteins. PCV7 serotypes had dramatically decreased by 2010 (P < 0.0001), and only 50% of all noninvasive infections were caused by the PCV13 capsular serotypes. Serotype 19A accounted for 32% of the noninvasive isolates, followed by serotypes 35B (9%), 19F (7%), and 6C (6%). After 7 years of PCV7 usage, there were no changes in the frequencies of the pspA or pspC genes; 96% of the strains were positive for family 1 or 2 pspA genes, and 81% were also positive for pspC. Unexpectedly, more noninvasive than invasive strains were positive for rrgC (P < 0.0001), and the proportion of rrgC-positive strains in 2008 to 2010 was greater than that in 2002 to 2008 (IPD, P < 0.02; noninvasive, P < 0.001). Serotypes 19F, 19A, and 35B were more frequently rrgC positive (P < 0.005) than other serotypes. A vaccine containing antigens, such as PspA, PspC, and/or RrgC, can provide coverage against most non-PCV13-type pneumococci. Continued surveillance is critical for optimal future vaccine development. PMID:24006139

  15. Yeast diversity associated with invasive Dendroctonus valens killing Pinus tabuliformis in China using culturing and molecular methods.

    PubMed

    Lou, Qiao-Zhe; Lu, Min; Sun, Jiang-Hua

    2014-08-01

    Bark beetle-associated yeasts are much less studied than filamentous fungi, yet they are also considered to play important roles in beetle nutrition, detoxification, and chemical communication. The red turpentine beetle, Dendroctonus valens, an invasive bark beetle introduced from North America, became one of the most destructive pests in China, having killed more than 10 million Pinus tabuliformis as well as other pine species. No investigation of yeasts associated with this bark beetle in its invaded ranges has been conducted so far. The aim of this study was to assess the diversity of yeast communities in different microhabitats and during different developmental stages of Den. valens in China using culturing and denaturing gradient gel electrophoresis (DGGE) approaches and to compare the yeast flora between China and the USA. The yeast identity was confirmed by sequencing the D1/D2 domain of LSU ribosomal DNA (rDNA). In total, 21 species (13 ascomycetes and eight basidiomycetes) were detected by culturing method, and 12 species (11 ascomycetes and one basidiomycetes) were detected by molecular methods from China. The most frequent five species in China were Candida piceae (Ogataea clade), Cyberlindnera americana, Candida oregonensis (Metschnikowia clade), Candida nitratophila (Ogataea clade) and an undescribed Saccharomycopsis sp., detected by both methods. Seven species were exclusively detected by DGGE. Ca. oregonensis (Metschnikowia clade) was the most frequently detected species by DGGE method. Eight species (all were ascomycetes) from the USA were isolated; seven of those were also found in China. We found significant differences in yeast total abundance as well as community composition between different developmental stages and significant differences between the surface and the gut. The frass yeast community was more similar to that of Den. valens surface or larvae than to the community of the gut or adults. Possible functions of the yeast associates are

  16. Nitrogen uptake: invasive annual vs. native perennial rangeland grasses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Incursion into perennial dominated rangelands of the Intermountain West by two winter exotic annual grasses, cheatgrass and medusahead, is one of the most serious plant invasion in North America. The invasions have decreased productivity and biological diversity and increased the frequency of range...

  17. Decreased expression of let-7c is associated with non-response of muscle-invasive bladder cancer patients to neoadjuvant chemotherapy

    PubMed Central

    Vinall, Ruth L.; Tepper, Clifford G.; Ripoll, Alexandra A. Z.; Gandour-Edwards, Regina F.; Durbin-Johnson, Blythe P.; Yap, Stanley A.; Ghosh, Paramita M.; deVere White, Ralph W.

    2016-01-01

    The identification and development of biomarkers which predict response of muscle invasive bladder cancer (MIBC) patients to neoadjuvant chemotherapy would likely increase usage of this treatment option and thereby improve patient survival rates. MiRNA array and qRT-PCR validation was used to identify miRNA which are associated with response to neoadjuvant chemotherapy. RNA was extracted from a total of 41 archival, fully annotated, MIBC patient diagnostic biopsies (20 chemo-responders and 21 non-responders (response is defined as > 5 year survival rate and being pT0 post-chemotherapy)). Microarray and qPCR identified let-7c as being differentially expressed in chemo-responder versus non-responder patients. Patients with higher let-7c expression levels had significantly higher odds of responding to chemotherapy (p = 0.023, OR 2.493, 95% CI 1.121, 5.546), and assessment of let-7c levels allowed for prediction of patient response (AUC 0.72, positive predictive value 59%). Decreased let-7c was associated with MIBC incidence (p < 0.001), and significantly correlated with other related miRNA including those that were not differentially expressed between responders and non-responders. The combined data indicate let-7c plays a role in mediating chemoresistance to neoadjuvant chemotherapy in MIBC patients, and is a modest, yet clinically meaningful, predictor of patient response. PMID:27382433

  18. Decreased expression of let-7c is associated with non-response of muscle-invasive bladder cancer patients to neoadjuvant chemotherapy.

    PubMed

    Vinall, Ruth L; Tepper, Clifford G; Ripoll, Alexandra A Z; Gandour-Edwards, Regina F; Durbin-Johnson, Blythe P; Yap, Stanley A; Ghosh, Paramita M; deVere White, Ralph W

    2016-03-01

    The identification and development of biomarkers which predict response of muscle invasive bladder cancer (MIBC) patients to neoadjuvant chemotherapy would likely increase usage of this treatment option and thereby improve patient survival rates. MiRNA array and qRT-PCR validation was used to identify miRNA which are associated with response to neoadjuvant chemotherapy. RNA was extracted from a total of 41 archival, fully annotated, MIBC patient diagnostic biopsies (20 chemo-responders and 21 non-responders (response is defined as > 5 year survival rate and being pT0 post-chemotherapy)). Microarray and qPCR identified let-7c as being differentially expressed in chemo-responder versus non-responder patients. Patients with higher let-7c expression levels had significantly higher odds of responding to chemotherapy (p = 0.023, OR 2.493, 95% CI 1.121, 5.546), and assessment of let-7c levels allowed for prediction of patient response (AUC 0.72, positive predictive value 59%). Decreased let-7c was associated with MIBC incidence (p < 0.001), and significantly correlated with other related miRNA including those that were not differentially expressed between responders and non-responders. The combined data indicate let-7c plays a role in mediating chemoresistance to neoadjuvant chemotherapy in MIBC patients, and is a modest, yet clinically meaningful, predictor of patient response. PMID:27382433

  19. Efficacy of a sensory deterrent and pipe modifications in decreasing entrainment of juvenile green sturgeon (Acipenser medirostris) at unscreened water diversions

    PubMed Central

    Poletto, Jamilynn B.; Cocherell, Dennis E.; Mussen, Timothy D.; Ercan, Ali; Bandeh, Hossein; Levent Kavvas, M.; Cech, Joseph J.; Fangue, Nann A.

    2014-01-01

    Water projects designed to extract fresh water for local urban, industrial and agricultural use throughout rivers and estuaries worldwide have contributed to the fragmentation and degradation of suitable habitat for native fishes. The number of water diversions located throughout the Sacramento–San Joaquin watershed in California's Central Valley exceeds 3300, and the majority of these are unscreened. Many anadromous fish species are susceptible to entrainment into these diversions, potentially impacting population numbers. In the laboratory, juvenile green sturgeon (Acipenser medirostris) have been shown to have high entrainment rates into unscreened diversions compared with those of other native California fish species, which may act as a significant source of mortality for this already-threatened species. Therefore, we tested the efficacy of a sensory deterrent (strobe light) and two structural pipe modifications (terminal pipe plate and upturned pipe configuration) in decreasing the entrainment of juvenile green sturgeon (mean mass ± SEM = 162.9 ± 4.0 g; mean fork length = 39.4 ± 0.3 cm) in a large (>500 kl) outdoor flume fitted with a water-diversion pipe 0.46 m in diameter. While the presence of the strobe light did not affect fish entrainment rates, the terminal pipe plate and upturned pipe modifications significantly decreased the proportion of fish entrained out of the total number tested relative to control conditions (0.13 ± 0.02 and 0.03 ± 0.02 vs. 0.44 ± 0.04, respectively). These data suggest that sensory deterrents using visual stimuli are not an effective means to reduce diversion pipe interactions for green sturgeon, but that structural alterations to diversions can successfully reduce entrainment for this species. Our results are informative for the development of effective management strategies to mitigate the impacts of water diversions on sturgeon populations and suggest that effective restoration

  20. Chronic Trichuris muris Infection Decreases Diversity of the Intestinal Microbiota and Concomitantly Increases the Abundance of Lactobacilli.

    PubMed

    Holm, Jacob Bak; Sorobetea, Daniel; Kiilerich, Pia; Ramayo-Caldas, Yuliaxis; Estellé, Jordi; Ma, Tao; Madsen, Lise; Kristiansen, Karsten; Svensson-Frej, Marcus

    2015-01-01

    The intestinal microbiota is vital for shaping the local intestinal environment as well as host immunity and metabolism. At the same time, epidemiological and experimental evidence suggest an important role for parasitic worm infections in maintaining the inflammatory and regulatory balance of the immune system. In line with this, the prevalence of persistent worm infections is inversely correlated with the incidence of immune-associated diseases, prompting the use of controlled parasite infections for therapeutic purposes. Despite this, the impact of parasite infection on the intestinal microbiota, as well as potential downstream effects on the immune system, remain largely unknown. We have assessed the influence of chronic infection with the large-intestinal nematode Trichuris muris, a close relative of the human pathogen Trichuris trichiura, on the composition of the murine intestinal microbiota by 16S ribosomal-RNA gene-based sequencing. Our results demonstrate that persistent T. muris infection dramatically affects the large-intestinal microbiota, most notably with a drop in the diversity of bacterial communities, as well as a marked increase in the relative abundance of the Lactobacillus genus. In parallel, chronic T. muris infection resulted in a significant shift in the balance between regulatory and inflammatory T cells in the intestinal adaptive immune system, in favour of inflammatory cells. Together, these data demonstrate that chronic parasite infection strongly influences the intestinal microbiota and the adaptive immune system. Our results illustrate the complex interactions between these factors in the intestinal tract, and contribute to furthering the understanding of this interplay, which is of crucial importance considering that 500 million people globally are suffering from these infections and their potential use for therapeutic purposes. PMID:25942314

  1. Chronic Trichuris muris Infection Decreases Diversity of the Intestinal Microbiota and Concomitantly Increases the Abundance of Lactobacilli

    PubMed Central

    Kiilerich, Pia; Ramayo-Caldas, Yuliaxis; Estellé, Jordi; Ma, Tao; Madsen, Lise; Kristiansen, Karsten; Svensson-Frej, Marcus

    2015-01-01

    The intestinal microbiota is vital for shaping the local intestinal environment as well as host immunity and metabolism. At the same time, epidemiological and experimental evidence suggest an important role for parasitic worm infections in maintaining the inflammatory and regulatory balance of the immune system. In line with this, the prevalence of persistent worm infections is inversely correlated with the incidence of immune-associated diseases, prompting the use of controlled parasite infections for therapeutic purposes. Despite this, the impact of parasite infection on the intestinal microbiota, as well as potential downstream effects on the immune system, remain largely unknown. We have assessed the influence of chronic infection with the large-intestinal nematode Trichuris muris, a close relative of the human pathogen Trichuris trichiura, on the composition of the murine intestinal microbiota by 16S ribosomal-RNA gene-based sequencing. Our results demonstrate that persistent T. muris infection dramatically affects the large-intestinal microbiota, most notably with a drop in the diversity of bacterial communities, as well as a marked increase in the relative abundance of the Lactobacillus genus. In parallel, chronic T. muris infection resulted in a significant shift in the balance between regulatory and inflammatory T cells in the intestinal adaptive immune system, in favour of inflammatory cells. Together, these data demonstrate that chronic parasite infection strongly influences the intestinal microbiota and the adaptive immune system. Our results illustrate the complex interactions between these factors in the intestinal tract, and contribute to furthering the understanding of this interplay, which is of crucial importance considering that 500 million people globally are suffering from these infections and their potential use for therapeutic purposes. PMID:25942314

  2. Exploring origins, invasion history and genetic diversity of Imperata cylindrica (L.) P. Beauv. (Cogongrass) in the United States using genotyping by sequencing.

    PubMed

    Burrell, A Millie; Pepper, Alan E; Hodnett, George; Goolsby, John A; Overholt, William A; Racelis, Alexis E; Diaz, Rodrigo; Klein, Patricia E

    2015-05-01

    Imperata cylindrica (Cogongrass, Speargrass) is a diploid C4 grass that is a noxious weed in 73 countries and constitutes a significant threat to global biodiversity and sustainable agriculture. We used a cost-effective genotyping-by-sequencing (GBS) approach to identify the reproductive system, genetic diversity and geographic origins of invasions in the south-eastern United States. In this work, we demonstrated the advantage of employing the closely related, fully sequenced crop species Sorghum bicolor (L.) Moench as a proxy reference genome to identify a set of 2320 informative single nucleotide and insertion-deletion polymorphisms. Genetic analyses identified four clonal lineages of cogongrass and one clonal lineage of Imperata brasiliensis Trin. in the United States. Each lineage was highly homogeneous, and we found no evidence of hybridization among the different lineages, despite geographical overlap. We found evidence that at least three of these lineages showed clonal reproduction prior to introduction to the United States. These results indicate that cogongrass has limited evolutionary potential to adapt to novel environments and further suggest that upon arrival to its invaded range, this species did not require local adaptation through hybridization/introgression or selection of favourable alleles from a broad genetic base. Thus, cogongrass presents a clear case of broad invasive success, across a diversity of environments, in a clonal organism with limited genetic diversity. PMID:25864837

  3. Molecular epidemiology of methicillin-resistant Staphylococcus aureus in Switzerland: sampling only invasive isolates does not allow a representative description of the local diversity of clones.

    PubMed

    Senn, L; Basset, P; Greub, G; Prod'hom, G; Frei, R; Zbinden, R; Gaia, V; Balmelli, C; Pfyffer, G E; Mühlemann, K; Zanetti, G; Blanc, D S

    2013-07-01

    We conducted a molecular study of MRSA isolated in Swiss hospitals, including the first five consecutive isolates recovered from blood cultures and the first ten isolates recovered from other sites in newly identified carriers. Among 73 MRSA isolates, 44 different double locus sequence typing (DLST) types and 32 spa types were observed. Most isolates belonged to the NewYork/Japan, the UK-EMRSA-15, the South German and the Berlin clones. In a country with a low to moderate MRSA incidence, inclusion of non-invasive isolates allowed a more accurate description of the diversity. PMID:23458418

  4. Luteolin decreases invasiveness, deactivates STAT3 signaling, and reverses interleukin-6 induced epithelial–mesenchymal transition and matrix metalloproteinase secretion of pancreatic cancer cells

    PubMed Central

    Huang, Xince; Dai, Shengjie; Dai, Juji; Xiao, Yuwu; Bai, Yongyu; Chen, Bicheng; Zhou, Mengtao

    2015-01-01

    Luteolin, a flavone, has been shown to exhibit anticancer properties. Here, we investigated whether luteolin affects epithelial–mesenchymal transition (EMT) and invasiveness of pancreatic cancer cell lines and their underlying mechanism. Pancreatic cancer cell lines PANC-1 and SW1990 were used in our study, and their EMT characters, matrix metalloproteinase (MMP) expression level, invasiveness, and signal transducer and activator of transcription 3 (STAT3) activity were determined after luteolin treatment. We also treated pancreatic cancer cells with interleukin-6 (IL-6) to see whether IL-6-induced activation of STAT3, EMT, and MMP secretion was affected by luteolin. We found that luteolin inhibits EMT and MMP2, MMP7, and MMP9 expression in a dose-dependent manner, similar to STAT3 signaling. Through Transwell assay, we found that invasiveness of pancreatic cancer cells was inhibited by luteolin. EMT characters and MMP secretion increase with STAT3 activity after IL-6 treatment and these effects, caused by IL-6, were inhibited by luteolin. We concluded that luteolin inhibits invasiveness of pancreatic cancer cells, and we speculated that luteolin inhibits EMT and MMP secretion likely through deactivation of STAT3 signaling. Luteolin has potential antitumor effects and merits further investigation. PMID:26527884

  5. Extreme differences in population structure and genetic diversity for three invasive congeners: knotweeds in western North America

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Japanese, giant, and the hybrid Bohemian knotweeds (Fallopia japonica, F. sachalinensis and F. x bohemica) have invaded the western USA and Canada, as well as other regions of the world. The distribution of these species in western North America, and their mode of invasion, is relatively unresolved....

  6. Human Mesenchymal Stem Cells of Diverse Origins Support Persistent Infection with Kaposi’s Sarcoma-Associated Herpesvirus and Manifest Distinct Angiogenic, Invasive, and Transforming Phenotypes

    PubMed Central

    Lee, Myung-Shin; Yuan, Hongfeng; Jeon, Hyungtaek; Zhu, Ying; Yoo, Seungmin; Shi, Songtao; Krueger, Brian; Renne, Rolf; Lu, Chun; Jung, Jae U.

    2016-01-01

    ABSTRACT Kaposi’s sarcoma (KS), a highly angiogenic and invasive tumor often involving different organ sites, including the oral cavity, is caused by infection with Kaposi’s sarcoma-associated herpesvirus (KSHV). Diverse cell markers have been identified on KS tumor cells, but their origin remains an enigma. We previously showed that KSHV could efficiently infect, transform, and reprogram rat primary mesenchymal stem cells (MSCs) into KS-like tumor cells. In this study, we showed that human primary MSCs derived from diverse organs, including bone marrow (MSCbm), adipose tissue (MSCa), dental pulp, gingiva tissue (GMSC), and exfoliated deciduous teeth, were permissive to KSHV infection. We successfully established long-term cultures of KSHV-infected MSCa, MSCbm, and GMSC (LTC-KMSCs). While LTC-KMSCs had lower proliferation rates than the uninfected cells, they expressed mixtures of KS markers and displayed differential angiogenic, invasive, and transforming phenotypes. Genetic analysis identified KSHV-derived microRNAs that mediated KSHV-induced angiogenic activity by activating the AKT pathway. These results indicated that human MSCs could be the KSHV target cells in vivo and established valid models for delineating the mechanism of KSHV infection, replication, and malignant transformation in biologically relevant cell types. PMID:26814175

  7. Diversity of Prophage DNA Regions of Streptococcus agalactiae Clonal Lineages from Adults and Neonates with Invasive Infectious Disease

    PubMed Central

    Salloum, Mazen; van der Mee-Marquet, Nathalie; Valentin-Domelier, Anne-Sophie; Quentin, Roland

    2011-01-01

    The phylogenetic position and prophage DNA content of the genomes of 142 S. agalactiae (group-B streptococcus, GBS) isolates responsible for bacteremia and meningitis in adults and neonates were studied and compared. The distribution of the invasive isolates between the various serotypes, sequence types (STs) and clonal complexes (CCs) differed significantly between adult and neonatal isolates. Use of the neighbor-net algorithm with the PHI test revealed evidence for recombination in the population studied (PHI, P = 2.01×10−6), and the recombination-mutation ratio (R/M) was 6∶7. Nevertheless, the estimated R/M ratio differed between CCs. Analysis of the prophage DNA regions of the genomes of the isolates assigned 90% of the isolates to five major prophage DNA groups: A to E. The mean number of prophage DNA fragments amplified per isolate varied from 2.6 for the isolates of prophage DNA group E to 4.0 for the isolates of prophage DNA group C. The isolates from adults and neonates with invasive diseases were distributed differently between the various prophage DNA groups (P<0.00001). Group C prophage DNA fragments were found in 52% of adult invasive isolates, whereas 74% of neonatal invasive isolates had prophage DNA fragments of groups A and B. Differences in prophage DNA content were also found between serotypes, STs and CCs (P<0.00001). All the ST-1 and CC1 isolates, mostly of serotype V, belonged to the prophage DNA group C, whereas 84% of the ST-17 and CC17 isolates, all of serotype III, belonged to prophage DNA groups A and B. These data indicate that the transduction mechanisms, i.e., gene transfer from one bacterium to another by a bacteriophage, underlying genetic recombination in S. agalactiae species, are specific to each intraspecies lineage and population of strains responsible for invasive diseases in adults and neonates. PMID:21633509

  8. Long-term balanced fertilization decreases arbuscular mycorrhizal fungal diversity in an arable soil in North China revealed by 454 pyrosequencing.

    PubMed

    Lin, Xiangui; Feng, Youzhi; Zhang, Huayong; Chen, Ruirui; Wang, Junhua; Zhang, Jiabao; Chu, Haiyan

    2012-06-01

    A balanced fertilization can increase crop yields partly due to stimulated microbial activities and growths. In this study, we investigated arbuscular mycorrhizal fungi (AMF) in arable soils to determine the optimal practices for an effective fertilization. We used pyrosequencing-based approach to study AMF diversity, as well as their responses to different long-term (>20 years) fertilizations, including OM (organic manure) and mix chemical fertilizers of NP (nitrogen-phosphorus), NK (nitrogen-potassium), and NPK (nitrogen-phosphorus-potassium). Results revealed that 124,998 of 18S rRNA gene fragments were dominated by Glomeromycota with 59,611 sequences, generating 70 operational taxonomic units (OTUs), of which the three largest families were Glomeraceae, Gigasporaceae and Acaulosporaceae. In Control and NK plots, AMF diversity and richness significantly decreased under long-term P fertilizations, such as NP, NPK, and OM. Concomitantly, the AMF community structure shifted. Supported by canonical correspondence analysis, we hereby propose that long-term balanced fertilization, especially P fertilizer with additional N fertilizer, helps the build-up of soil nutrients. Consequently, some AMF community constituents are sacrificed, propelled by the self-regulation of plant-AMF-microbes system, resulting in an agro-ecosystem with a better sustainability. This knowledge would be valuable toward better understandings of AMF community in agro-ecosystem, and long-term ecosystem benefits of the balanced fertilization. PMID:22582875

  9. Elucidating the native sources of an invasive tree species, Acacia pycnantha, reveals unexpected native range diversity and structure

    PubMed Central

    Ndlovu, Joice; Richardson, David M.; Wilson, John R. U.; O'Leary, Martin; Le Roux, Johannes J.

    2013-01-01

    Background and Aims Understanding the introduction history of invasive plant species is important for their management and identifying effective host-specific biological control agents. However, uncertain taxonomy, intra- and interspecific hybridization, and cryptic speciation may obscure introduction histories, making it difficult to identify native regions to explore for host-specific agents. The overall aim of this study was to identify the native source populations of Acacia pycnantha, a tree native to south-eastern Australia and invasive in South Africa, Western Australia and Portugal. Using a phylogeographical approach also allowed an exploration of the historical processes that have shaped the genetic structure of A. pycnantha in its native range. Methods Nuclear (nDNA) and plastid DNA sequence data were used in network and tree-building analyses to reconstruct phylogeographical relationships between native and invasive A. pycnantha populations. In addition, mismatch distributions, relative rates and Bayesian analyses were used to infer recent demographic processes and timing of events in Australia that led to population structure and diversification. Key Results The plastid network indicated that Australian populations of A. pycnantha are geographically structured into two informally recognized lineages, the wetland and dryland forms, whereas the nuclear phylogeny showed little geographical structure between these two forms. Moreover, the dryland form of A. pycnantha showed close genetic similarity to the wetland form based on nDNA sequence data. Hybrid zones may explain these findings, supported here by incongruent phylogenetic placement of some of these taxa between nuclear and plastid genealogies. Conclusions It is hypothesized that habitat fragmentation due to cycles of aridity inter-dispersed with periods of abundant rainfall during the Pleistocene (approx. 100 kya) probably gave rise to native dryland and wetland forms of A. pycnantha. Although the

  10. Inhibitory effect of berberine on the invasion of human lung cancer cells via decreased productions of urokinase-plasminogen activator and matrix metalloproteinase-2

    SciTech Connect

    Peng, P.-L.; Hsieh, Y.-S.; Wang, C.-J.; Hsu, J.-L.; Chou, F.-P. . E-mail: fpchou@csmu.edu.tw

    2006-07-01

    Berberine, a compound isolated from medicinal herbs, has been reported with many pharmacological effects related to anti-cancer and anti-inflammation capabilities. In this study, we observed that berberine exerted a dose- and time-dependent inhibitory effect on the motility and invasion ability of a highly metastatic A549 cells under non-cytotoxic concentrations. In cancer cell migration and invasion process, matrix-degrading proteinases are required. A549 cell treated with berberine at various concentrations showed reduced ECM proteinases including matrix metalloproteinase-2 (MMP2) and urokinase-plasminogen activator (u-PA) by gelatin and casein zymography analysis. The inhibitory effect is likely to be at the transcriptional level, since the reduction in the transcripts levels was corresponding to the proteins. Moreover, berberine also exerted its action via regulating tissue inhibitor of metalloproteinase-2 (TIMP-2) and urokinase-plasminogen activator inhibitor (PAI). The upstream mediators of the effect involved c-jun, c-fos and NF-{kappa}B, as evidenced by reduced phosphorylation of the proteins. These findings suggest that berberine possesses an anti-metastatic effect in non-small lung cancer cell and may, therefore, be helpful in clinical treatment.

  11. Decreased expression of DNA repair genes (XRCC1, ERCC1, ERCC2, and ERCC4) in squamous intraepithelial lesion and invasive squamous cell carcinoma of the cervix.

    PubMed

    Bajpai, Deepti; Banerjee, Ayan; Pathak, Sujata; Jain, Sunesh K; Singh, Neeta

    2013-05-01

    Reduced DNA repair might affect the risk of progression from infection with carcinogenic human papillomavirus (HPV), the etiologic agent for cervical cancer (CC), to persistent HPV infection, and hence to cervical pre-cancer and cancer. We assessed the variation in baseline expression of base excision repair gene XRCC1 and three nucleotide excision repair genes ERCC1, ERCC2, and ERCC4 and the risk of developing cervical cancer. A hospital-based case-control study was designed with 50 invasive cervical cancer patients, 40 squamous intraepithelial lesions (SIL) patients and 85 controls subjects. RT-qPCR and Western blotting was used to quantitate in vitro the mRNA and protein levels in fresh CC, SIL and normal cervix tissue. The levels of XRCC1, ERCC2, ERCC4, and ERCC1 transcripts and their respective proteins were lower in cervical cancer and SILs as compared to controls (p ≤ 0.001, 0.001, 0.001, and 0.025, respectively). In multivariate logistic regression analysis (adjusting for parity, age at first child birth, use of oral contraceptives, smoking status), low expression of XRCC1, ERCC2, ERCC4, and ERCC1 was associated with a significant increased risk for CC and SIL. Our results suggest that individuals whose expression of XRCC1, ERCC4, ERCC2, and ERCC1 are reduced may be at a higher risk of developing SIL which eventually leads to invasive cervical carcinoma. Moreover, independently also the reduced expression of these genes can directly lead to cervical cancer progression. PMID:23435956

  12. Elevated integrin α6β4 expression is associated with venous invasion and decreased overall survival in non-small cell lung cancer.

    PubMed

    Stewart, Rachel L; West, Dava; Wang, Chi; Weiss, Heidi L; Gal, Tamas; Durbin, Eric B; O'Connor, William; Chen, Min; O'Connor, Kathleen L

    2016-08-01

    Lung cancer carries a poor prognosis and is the most common cause of cancer-related death worldwide. The integrin α6β4, a laminin receptor, promotes carcinoma progression in part by cooperating with various growth factor receptors to facilitate invasion and metastasis. In carcinoma cells with mutant TP53, the integrin α6β4 promotes cell survival. TP53 mutations and integrin α6β4 overexpression co-occur in many aggressive malignancies. Because of the high frequency of TP53 mutations in lung squamous cell carcinoma (SCC), we sought to investigate the association of integrin β4 expression with clinicopathologic features and survival in non-small cell lung cancer (NSCLC). We constructed a lung cancer tissue microarray and stained sections for integrin β4 subunit expression using immunohistochemistry. We found that integrin β4 expression is elevated in SCC compared with adenocarcinoma (P<.0001), which was confirmed in external gene expression data sets (P<.0001). We also determined that integrin β4 overexpression associates with the presence of venous invasion (P=.0048) and with reduced overall patient survival (hazard ratio, 1.46; 95% confidence interval, 1.01-2.09; P=.0422). Elevated integrin β4 expression was also shown to associate with reduced overall survival in lung cancer gene expression data sets (hazard ratio, 1.49; 95% confidence interval, 1.31-1.69; P<.0001). Using cBioPortal, we generated a network map demonstrating the 50 most highly altered genes neighboring ITGB4 in SCC, which included laminins, collagens, CD151, genes in the EGFR and PI3K pathways, and other known signaling partners. In conclusion, we demonstrate that integrin β4 is overexpressed in NSCLC where it is an adverse prognostic marker. PMID:27107458

  13. Renal Function Outcomes and Risk Factors for Risk Factors for Stage 3B Chronic Kidney Disease after Urinary Diversion in Patients with Muscle Invasive Bladder Cancer

    PubMed Central

    Hatakeyama, Shingo; Koie, Takuya; Narita, Takuma; Hosogoe, Shogo; Yamamoto, Hayato; Tobisawa, Yuki; Yoneyama, Tohru; Yoneyama, Takahiro; Hashimoto, Yasuhiro; Ohyama, Chikara

    2016-01-01

    Objectives To assess the effects of urinary diversion on renal function, we retrospectively investigated renal function over 5 years after urinary diversion using a propensity score matching strategy. Methods Between May 1996 and November 2013, 345 consecutive adult patients underwent radical cystectomy and urinary diversion in our hospital; one hundred and fifteen patients with more than a 5-year follow-up were enrolled. Propensity scores were calculated using logistic analysis, and the data used in the analyses included age, gender, Eastern Cooperative Oncology Group Performance Status (ECOG-PS), clinical tumor stage, presence of cardiovascular disease; hypertension; and type 2 diabetes and preoperative eGFR at the initial visit. Multivariate logistic regression analysis was used to assess the risk factors for stage 3B chronic kidney disease (CKD) after the different types of urinary diversion. Results Continent and incontinent diversion were performed in 68 and 47 patients, respectively. The mean preoperative eGFR was significantly lower in the incontinent than in the continent group (P < 0.001). In propensity score-matched patients (n = 34 each), no significant differences were observed in pre- and postoperative eGFR and 5-year eGFR decrease rates between the groups. In the incontinent group, the number of postoperative stage 3B CKD patients was significantly increased than the continent group. Using multivariate analysis, independent risk factors significantly associated with stage 3B CKD at 5 years after surgery were older age, eGFR before surgery, incontinent diversion (cutaneous ureterostomy), and postoperative hydronephrosis. Conclusions The types of urinary diversion had no significant impact on renal function decline, whereas older age, preexisting impaired renal function, postoperative hydronephrosis, and cutaneous ureterostomy were independent risk factors for stage 3B CKD at 5 years after radical cystectomy. PMID:26901860

  14. Effects of invasive plants on arthropods.

    PubMed

    Litt, Andrea R; Cord, Erin E; Fulbright, Timothy E; Schuster, Greta L

    2014-12-01

    Non-native plants have invaded nearly all ecosystems and represent a major component of global ecological change. Plant invasions frequently change the composition and structure of vegetation communities, which can alter animal communities and ecosystem processes. We reviewed 87 articles published in the peer-reviewed literature to evaluate responses of arthropod communities and functional groups to non-native invasive plants. Total abundance of arthropods decreased in 62% of studies and increased in 15%. Taxonomic richness decreased in 48% of studies and increased in 13%. Herbivorous arthropods decreased in response to plant invasions in 48% of studies and increased in 17%, likely due to direct effects of decreased plant diversity. Predaceous arthropods decreased in response to invasive plants in 44% of studies, which may reflect indirect effects due to reductions in prey. Twenty-two percent of studies documented increases in predators, which may reflect changes in vegetation structure that improved mobility, survival, or web-building for these species. Detritivores increased in 67% of studies, likely in response to increased litter and decaying vegetation; no studies documented decreased abundance in this functional group. Although many researchers have examined effects of plant invasions on arthropods, sizeable information gaps remain, specifically regarding how invasive plants influence habitat and dietary requirements. Beyond this, the ability to predict changes in arthropod populations and communities associated with plant invasions could be improved by adopting a more functional and mechanistic approach. Understanding responses of arthropods to invasive plants will critically inform conservation of virtually all biodiversity and ecological processes because so many organisms depend on arthropods as prey or for their functional roles, including pollination, seed dispersal, and decomposition. Given their short generation times and ability to respond rapidly to

  15. Correlation between Genotypic Diversity, Lipooligosaccharide Gene Locus Class Variation, and Caco-2 Cell Invasion Potential of Campylobacter jejuni Isolates from Chicken Meat and Humans: Contribution to Virulotyping▿

    PubMed Central

    Habib, Ihab; Louwen, Rogier; Uyttendaele, Mieke; Houf, Kurt; Vandenberg, Olivier; Nieuwenhuis, Edward E.; Miller, William G.; van Belkum, Alex; De Zutter, Lieven

    2009-01-01

    Significant interest in studying the lipooligosaccharide (LOS) of Campylobacter jejuni has stemmed from its potential role in postinfection paralytic disorders. In this study we present the results of PCR screening of five LOS locus classes (A, B, C, D, and E) for a collection of 116 C. jejuni isolates from chicken meat (n = 76) and sporadic human cases of diarrhea (n = 40). We correlated LOS classes with clonal complexes (CC) assigned by multilocus sequence typing (MLST). Finally, we evaluated the invasion potential of a panel of 52 of these C. jejuni isolates for Caco-2 cells. PCR screening showed that 87.1% (101/116) of isolates could be assigned to LOS class A, B, C, D, or E. Concordance between LOS classes and certain MLST CC was revealed. The majority (85.7% [24/28]) of C. jejuni isolates grouped in CC-21 were shown to express LOS locus class C. The invasion potential of C. jejuni isolates possessing sialylated LOS (n = 29; classes A, B, and C) for Caco-2 cells was significantly higher (P < 0.0001) than that of C. jejuni isolates with nonsialylated LOS (n = 23; classes D and E). There was no significant difference in invasiveness between chicken meat and human isolates. However, C. jejuni isolates assigned to CC-206 (correlated with LOS class B) or CC-21 (correlated with LOS class C) showed statistically significantly higher levels of invasion than isolates from other CC. Correlation between LOS classes and CC was further confirmed by pulsed-field gel electrophoresis. The present study reveals a correlation between genotypic diversity and LOS locus classes of C. jejuni. We showed that simple PCR screening for C. jejuni LOS classes could reliably predict certain MLST CC and add to the interpretation of molecular-typing results. Our study corroborates that sialylation of LOS is advantageous for C. jejuni fitness and virulence in different hosts. The modulation of cell surface carbohydrate structure could enhance the ability of C. jejuni to adapt to or survive

  16. Development of a versatile enzyme immunoassay for non-invasive assessment of glucocorticoid metabolites in a diversity of taxonomic species.

    PubMed

    Watson, Rebecca; Munro, Coralie; Edwards, Katie L; Norton, Vicki; Brown, Janine L; Walker, Susan L

    2013-06-01

    Endocrinology is a useful tool for conservation biologists and animal managers, and measuring glucocorticoids can help understand biological mechanisms associated with species decline and animal welfare. The current study describes the development and optimization of a glucocorticoid enzyme immunoassay (EIA) to non-invasively assess adrenal activity in a variety of taxa. The antiserum (CJM006) was raised in rabbits to a corticosterone-3-CMO-BSA immunogen and used in a standard competitive EIA system. However, the EIA initially produced results with unacceptably high inter-assay variation, attributed to consistent patterns observed within the optical density of developing plates. To determine the cause of this variability, a number of factors were examined using synthetic corticosterone standard and endogenous faecal extract, including: plate type (Nunc MaxiSorp® II versus Immulon IB plates); the use of non-specific secondary antibody; type (artificial versus natural) and presence (light versus dark) of light during incubation; plate loading temperature (4°C versus room temperature); and substrate reagent temperature (4°C versus room temperature). Results indicated that variability was associated with plate location effects, which were not initially detected because control samples were always run in the same positions across plates. Light and temperature were the two major factors that affected EIA reliability. For this assay, the standard protocol required slight modification, with the optimal protocol using Nunc MaxiSorp® plates, room temperature substrate reagents and dark incubation conditions. Following optimization, this EIA was then validated biochemically for 38 species, through parallel displacement curves and interference assessment tests of faecal and urine samples. Additionally, biological validation was performed opportunistically in a subset of species, with use of this EIA demonstrating significant elevations in faecal glucocorticoid metabolites

  17. Decreased morbidity following long saphenous vein harvesting using a minimally invasive technique: a randomised controlled trial comparing two techniques for long saphenous vein harvest

    PubMed Central

    Mahmood, Zahid; Al Benna, Sammy; Nkere, Udim; Murday, Andrew

    2006-01-01

    Objectives The objective of this study was to compare the morbidity associated with long saphenous vein harvesting using the traditional open technique (A) against a minimally invasive technique using the Mayo vein stripper (B) that involves multiple short incisions. Design We conducted a prospective randomized controlled study in 80 patients undergoing first time coronary artery bypass grafting. Pain and healing was assessed on each postoperative day. Rings of long saphenous vein were subjected to organ-bath evaluation of endothelium-dependent and endothelium-independent relaxation. Results Three patients were excluded from the study, leaving 38 patients in Group A and 39 in Group B. With respect to operative procedure, Group A had a greater length of vein harvested than Group B. There was no statistical difference in pain scores and endothelium-dependent or endothelium-independent relaxation between the two groups. However there were significantly more infections in Group A compared with Group B. Conclusion Harvesting vein through multiple incisions using the Mayo vein stripper is quicker, results in fewer infections and has no deleterious effect on endothelial function compared to open technique. PMID:16759395

  18. Huaier restrains proliferative and invasive potential of human hepatoma SKHEP-1 cells partially through decreased Lamin B1 and elevated NOV.

    PubMed

    Hu, Zhongdong; Yang, Ailin; Su, Guozhu; Zhao, Yunfang; Wang, Ying; Chai, Xingyun; Tu, Pengfei

    2016-01-01

    Hepatocellular carcinoma (HCC) is one of the most common cause of malignancy-related mortality worldwide. It is urgently needed to develop potential drugs with good efficacy and low toxicity for HCC treatment. The anti-tumor effect of Traditional Chinese Medicine (TCM) has received increasing attention worldwide. Trametes robiniophila Murr. (Huaier) has been used in TCM for approximately 1,600 years. Clinically, Huaier has satisfactory therapeutic effects in cancer treatment, especially in HCC. However, the mechanisms underlying the anti-cancer effect of Huaier remain ill defined. Herein we have demonstrated that Huaier dramatically inhibited cell proliferation and induced apoptosis in human hepatoma cell line SKHEP-1. Importantly, Huaier restrained the metastatic capability of SKHEP-1 cells. Mechanistically, down-regulation of Lamin B1 and up-regulation of Nephroblastoma overexpressed (NOV) were at least partially responsible for the inhibitory effect of Huaier on the proliferative and invasive capacity of SKHEP-1 cells. Our finding provided new insights into mechanisms of anti-HCC effect of Huaier and suggested a new scientific basis for clinical medication. PMID:27503760

  19. Activation of Estrogen Receptor Transfected into a Receptor-Negative Brest Cancer Cell Line Decreases the Metastatic and Invasive Potential of the Cells

    NASA Astrophysics Data System (ADS)

    Garcia, Marcel; Derocq, Danielle; Freiss, Gilles; Rochefort, Henri

    1992-12-01

    Breast cancers containing estrogen receptors are responsive to antiestrogen treatment and have a better prognosis than estrogen receptor-negative tumors. The loss of estrogen and progesterone receptors appears to be associated with a progression to less-differentiated tumors. We transfected the human estrogen receptor into the estrogen receptor-negative metastatic breast cancer cell line MDA-MB-231 in an attempt to restore their sensitivity to antiestrogens. Two stable sublines of MDA-MB-231 cells (HC1 and HE5) expressing functional estrogen receptors were studied for their ability to grow and invade in vitro and to metastasize in athymic nude mice. The number and size of lung metastases developed by these two sublines in ovariectomized nude mice was not markedly altered by tamoxifen but was inhibited 3-fold by estradiol. Estradiol also significantly inhibited in vitro cell proliferation of these sublines and their invasiveness in Matrigel, a reconstituted basement membrane, whereas the antiestrogens 4-hydroxytamoxifen and ICI 164,384 reversed these effects. These results show that estradiol inhibits the metastatic ability of estrogen receptornegative breast cancer cells following transfection with the estrogen receptor, whereas estrogen receptor-positive breast cancers are stimulated by estrogen, indicating that factors other than the estrogen receptor are involved in progression toward hormone independence. Reactivation or transfer of the estrogen receptor gene can therefore be considered as therapeutic approaches to hormone-independent cancers

  20. Huaier restrains proliferative and invasive potential of human hepatoma SKHEP-1 cells partially through decreased Lamin B1 and elevated NOV

    PubMed Central

    Hu, Zhongdong; Yang, Ailin; Su, Guozhu; Zhao, Yunfang; Wang, Ying; Chai, Xingyun; Tu, Pengfei

    2016-01-01

    Hepatocellular carcinoma (HCC) is one of the most common cause of malignancy-related mortality worldwide. It is urgently needed to develop potential drugs with good efficacy and low toxicity for HCC treatment. The anti-tumor effect of Traditional Chinese Medicine (TCM) has received increasing attention worldwide. Trametes robiniophila Murr. (Huaier) has been used in TCM for approximately 1,600 years. Clinically, Huaier has satisfactory therapeutic effects in cancer treatment, especially in HCC. However, the mechanisms underlying the anti-cancer effect of Huaier remain ill defined. Herein we have demonstrated that Huaier dramatically inhibited cell proliferation and induced apoptosis in human hepatoma cell line SKHEP-1. Importantly, Huaier restrained the metastatic capability of SKHEP-1 cells. Mechanistically, down-regulation of Lamin B1 and up-regulation of Nephroblastoma overexpressed (NOV) were at least partially responsible for the inhibitory effect of Huaier on the proliferative and invasive capacity of SKHEP-1 cells. Our finding provided new insights into mechanisms of anti-HCC effect of Huaier and suggested a new scientific basis for clinical medication. PMID:27503760

  1. Diversion of intestinal flow decreases the numbers of interleukin 4 secreting and interferon γ secreting T lymphocytes in small bowel mucosa

    PubMed Central

    Schmit, A; Van Gossum, A; Carol, M; Houben, J; Mascart, F

    2000-01-01

    BACKGROUND/AIMS—The intestinal immune system faces large amounts of antigens, and its regulation is tightly balanced by cytokines. In this study, the effect of intestinal flow diversion on spontaneous secretion of interleukin (IL)-4 and interferon (IFN)- γ was analysed.
METHODS—Eight patients (two with Crohn's disease, four with ulcerative colitis, and two with previous colon cancer) carrying a double lumen small bowel stoma after a total colectomy procedure were included in the study. For each patient, eight biopsy samples were taken endoscopically from both the diverted and non-diverted part of the small bowel. Intraepithelial lymphocytes (IELs) and lamina propria lymphocytes (LPLs) were isolated separately and assayed for numbers of cells spontaneously secreting IL-4 and/or IFN-γ by an ELISPOT technique.
RESULTS—Compared with the non-diverted mucosa, a significant decrease in the number of spontaneously IFN-γ secreting CD3 lymphocytes was observed in the diverted small bowel mucosa among both IELs (p = 0.008) and LPLs (p = 0.007). The same results, although less significant, were obtained for IL-4, especially in LPLs (p = 0.01).
CONCLUSION—The intestinal content influences the spontaneous secretion of IFN-γ and IL-4 by intestinal lymphocytes. These results could help to elucidate the anti-inflammatory role of split ileostomy in patients suffering from inflammatory bowel diseases.


Keywords: intestine; T lymphocytes; mucosa; interleukin-4; interferon-γ; ELISPOT PMID:10601053

  2. Genetic monitoring detects an overlooked cryptic species and reveals the diversity and distribution of three invasive Rattus congeners in south Africa

    PubMed Central

    2011-01-01

    Background South Africa's long and extensive trade activity has ensured ample opportunities for exotic species introduction. Whereas the rich biodiversity of endemic southern African fauna has been the focus of many studies, invasive vertebrates are generally overlooked despite potential impacts on biodiversity, health and agriculture. Genetic monitoring of commensal rodents in South Africa which uncovered the presence of Rattus tanezumi, a South-East Asian endemic not previously known to occur in Africa, provided the impetus for expanded studies on all invasive Rattus species present. Results To this end, intensified sampling at 28 South African localities and at one site in Swaziland, identified 149 Rattus specimens. Cytochrome b gene sequencing revealed the presence of two R. tanezumi, seven Rattus rattus and five Rattus norvegicus haplotypes in south Africa. Phylogenetic results were consistent with a single, recent R. tanezumi introduction and indicated that R. norvegicus and R. rattus probably became established following at least two and three independent introductions, respectively. Intra- and inter-specific diversity was highest in informal human settlements, with all three species occurring at a single metropolitan township site. Rattus norvegicus and R. rattus each occurred sympatrically with Rattus tanezumi at one and five sites, respectively. Karyotyping of selected R. rattus and R. tanezumi individuals identified diploid numbers consistent with those reported previously for these cryptic species. Ordination of bioclimatic variables and MaxEnt ecological niche modelling confirmed that the bioclimatic niche occupied by R. tanezumi in south Africa was distinct from that occupied in its naturalised range in south-east Asia suggesting that factors other than climate may influence the distribution of this species. Conclusions This study has highlighted the value of genetic typing for detecting cryptic invasive species, providing historical insights into

  3. Endosymbiotic and Host Proteases in the Digestive Tract of the Invasive Snail Pomacea canaliculata: Diversity, Origin and Characterization

    PubMed Central

    Godoy, Martín S.; Castro-Vasquez, Alfredo; Vega, Israel A.

    2013-01-01

    Digestive proteases of the digestive tract of the apple snail Pomacea canaliculata were studied. Luminal protease activity was found in the crop, the style sac and the coiled gut and was significantly higher in the coiled gut. Several protease bands and their apparent molecular weights were identified in both tissue extracts and luminal contents by gel zymography: (1) a 125 kDa protease in salivary gland extracts and in the crop content; (2) a 30 kDa protease throughout all studied luminal contents and in extracts of the midgut gland and of the endosymbionts isolated from this gland; (3) two proteases of 145 and 198 kDa in the coiled gut content. All these proteases were inhibited by aprotinin, a serine-protease inhibitor, and showed maximum activity between 30°C and 35°C and pH between 8.5 and 9.5. Tissue L-alanine-N-aminopeptidase activity was determined in the wall of the crop, the style sac and the coiled gut and was significantly higher in the coiled gut. Our findings show that protein digestion in P. canaliculata is carried out through a battery of diverse proteases originated from the salivary glands and the endosymbionts lodged in the midgut gland and by proteases of uncertain origin that occur in the coiled gut lumen. PMID:23818959

  4. 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

  5. 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

  6. An extreme cytoplasmic bottleneck in the modern European cultivated potato (Solanum tuberosum) is not reflected in decreased levels of nuclear diversity

    PubMed Central

    Provan, J.; Powell, W; Dewar, H.; Bryan, G.; Machray, G. C.; Waugh, R.

    1999-01-01

    We have used the polymorphic chloroplast (cp) and nuclear simple sequence repeats (SSRs) to analyse levels of cytoplasmic and nuclear diversity in the gene pool of the European cultivated potato (Solanum tuberosum ssp. tuberosum). Primers designed from the complete chloroplast sequence of tobacco (Nicotiana tabacum) were used to amplify polymorphic products in a range of potato cultivars. Combining the data from seven polymorphic cpSSR loci gave 26 haplotypes, one of which (haplotype A) accounted for 151 out of the 178 individuals studied and corresponded to the T-type cytoplasm previously identified in cultivated potatoes using chloroplast restriction fragment length polymorphism analysis. Phylogenetic and diversity analyses of the relationships between cpSSR haplotypes confirmed much higher levels of cytoplasmic diversity outwith the T-type group. Diversity levels at eight nuclear SSR loci, however, were not significantly different between cytoplasmic groups, suggesting a severe maternal bottleneck in the evolution of the modern cultivated potato. These results highlight the importance in quantifying levels of cytoplasmic as well as nuclear diversity and confirm the need for a change in breeding practices to increase levels of non-T-type cytoplasm in the cultivated gene pool, thus helping reduce problems associated with pollen sterility. This may be facilitated by germplasm analysis using cpSSRs, which will allow efficient selection of diverse cytoplasm donors.

  7. Decreasing incidence and changes in serotype distribution of invasive pneumococcal disease in persons aged under 18 years since introduction of 10-valent and 13-valent conjugate vaccines in Portugal, July 2008 to June 2012.

    PubMed

    Aguiar, S I; Brito, M J; Horacio, A N; Lopes, J P; Ramirez, M; Melo-Cristino, J

    2014-01-01

    The 10-valent pneumococcal conjugate vaccine (PCV10) became available in Portugal in mid-2009 and the 13-valent vaccine (PCV13) in early 2010. The incidence of invasive pneumococcal disease (IPD) in patients aged under 18 years decreased from 8.19 cases per 100,000 in 2008–09 to 4.52/100,000 in 2011–12. However, IPD incidence due to the serotypes included in the 7-valent conjugate vaccine (PCV7) in children aged under two years remained constant. This fall resulted from significant decreases in the number of cases due to: (i) the additional serotypes included in PCV10 and PCV13 (1, 5, 7F; from 37.6% to 20.6%), particularly serotype 1 in older children; and (ii) the additional serotypes included in PCV13 (3, 6A, 19A; from 31.6% to 16.2%), particularly serotype 19A in younger children. The decrease in serotype 19A before vaccination indicates that it was not triggered by PCV13 administration. The decrease of serotype 1 in all groups, concomitant with the introduction of PCV10, is also unlikely to have been triggered by vaccination, although PCVs may have intensified and supported these trends. PCV13 serotypes remain major causes of IPD, accounting for 63.2% of isolates recovered in Portugal in 2011–12, highlighting the potential role of enhanced vaccination in reducing paediatric IPD in Portugal. PMID:24698140

  8. Impacts of invasive plants on resident animals across ecosystems, taxa, and feeding types: a global assessment.

    PubMed

    Schirmel, Jens; Bundschuh, Mirco; Entling, Martin H; Kowarik, Ingo; Buchholz, Sascha

    2016-02-01

    As drivers of global change, biological invasions have fundamental ecological consequences. However, it remains unclear how invasive plant effects on resident animals vary across ecosystems, animal classes, and functional groups. We performed a comprehensive meta-analysis covering 198 field and laboratory studies reporting a total of 3624 observations of invasive plant effects on animals. Invasive plants had reducing (56%) or neutral (44%) effects on animal abundance, diversity, fitness, and ecosystem function across different ecosystems, animal classes, and feeding types while we could not find any increasing effect. Most importantly, we found that invasive plants reduced overall animal abundance, diversity and fitness. However, this significant overall effect was contingent on ecosystems, taxa, and feeding types of animals. Decreasing effects of invasive plants were most evident in riparian ecosystems, possibly because frequent disturbance facilitates more intense plant invasions compared to other ecosystem types. In accordance with their immediate reliance on plants for food, invasive plant effects were strongest on herbivores. Regarding taxonomic groups, birds and insects were most strongly affected. In insects, this may be explained by their high frequency of herbivory, while birds demonstrate that invasive plant effects can also cascade up to secondary consumers. Since data on impacts of invasive plants are rather limited for many animal groups in most ecosystems, we argue for overcoming gaps in knowledge and for a more differentiated discussion on effects of invasive plant on native fauna. PMID:26390918

  9. Southern leaf blight disease severity is correlated with decreased maize leaf epiphytic bacterial species richness and the phyllosphere bacterial diversity decline is enhanced by nitrogen fertilization

    PubMed Central

    Manching, Heather C.; Balint-Kurti, Peter J.; Stapleton, Ann E.

    2014-01-01

    Plant leaves are inhabited by a diverse group of microorganisms that are important contributors to optimal growth. Biotic and abiotic effects on plant growth are usually studied in controlled settings examining response to variation in single factors and in field settings with large numbers of variables. Multi-factor experiments with combinations of stresses bridge this gap, increasing our understanding of the genotype-environment-phenotype functional map for the host plant and the affiliated epiphytic community. The maize inbred B73 was exposed to single and combination abiotic and the biotic stress treatments: low nitrogen fertilizer and high levels of infection with southern leaf blight (causal agent Cochliobolus heterostrophus). Microbial epiphyte samples were collected at the vegetative early-season phase and species composition was determined using 16S ribosomal intergenic spacer analysis. Plant traits and level of southern leaf blight disease were measured late-season. Bacterial diversity was different among stress treatment groups (P < 0.001). Lower species richness—alpha diversity—was correlated with increased severity of southern leaf blight disease when disease pressure was high. Nitrogen fertilization intensified the decline in bacterial alpha diversity. While no single bacterial ribotype was consistently associated with disease severity, small sets of ribotypes were good predictors of disease levels. Difference in leaf bacterial-epiphyte diversity early in the season were correlated with plant disease severity, supporting further tests of microbial epiphyte-disease correlations for use in predicting disease progression. PMID:25177328

  10. Genomic comparison of multi-drug resistant invasive and colonizing Acinetobacter baumannii isolated from diverse human body sites reveals genomic plasticity

    PubMed Central

    2011-01-01

    Background Acinetobacter baumannii has recently emerged as a significant global pathogen, with a surprisingly rapid acquisition of antibiotic resistance and spread within hospitals and health care institutions. This study examines the genomic content of three A. baumannii strains isolated from distinct body sites. Isolates from blood, peri-anal, and wound sources were examined in an attempt to identify genetic features that could be correlated to each isolation source. Results Pulsed-field gel electrophoresis, multi-locus sequence typing and antibiotic resistance profiles demonstrated genotypic and phenotypic variation. Each isolate was sequenced to high-quality draft status, which allowed for comparative genomic analyses with existing A. baumannii genomes. A high resolution, whole genome alignment method detailed the phylogenetic relationships of sequenced A. baumannii and found no correlation between phylogeny and body site of isolation. This method identified genomic regions unique to both those isolates found on the surface of the skin or in wounds, termed colonization isolates, and those identified from body fluids, termed invasive isolates; these regions may play a role in the pathogenesis and spread of this important pathogen. A PCR-based screen of 74 A. baumanii isolates demonstrated that these unique genes are not exclusive to either phenotype or isolation source; however, a conserved genomic region exclusive to all sequenced A. baumannii was identified and verified. Conclusions The results of the comparative genome analysis and PCR assay show that A. baumannii is a diverse and genomically variable pathogen that appears to have the potential to cause a range of human disease regardless of the isolation source. PMID:21639920

  11. The diversity and prevalence of hard ticks attacking human hosts in Eastern Siberia (Russian Federation) with first description of invasion of non-endemic tick species.

    PubMed

    Khasnatinov, Maxim Anatolyevich; Liapunov, Alexander Valeryevich; Manzarova, Ellina Lopsonovna; Kulakova, Nina Viktorovna; Petrova, Irina Viktorovna; Danchinova, Galina Anatolyevna

    2016-02-01

    Hard ticks are the vectors of many pathogens including tick-borne encephalitis virus and the Lyme disease agent Borrelia burgdorferi sensu lato. In Eastern Siberia, Ixodes persulcatus, Dermacentor nuttalli, Dermacentor silvarum and Haemaphysalis concinna are regarded as aggressive to humans. Recently, significant changes in world tick fauna have been reported and this affects the spread of tick-borne pathogens. We studied the current species diversity, population structure and prevalence of tick-borne pathogens of hard ticks (Acari: Ixodidae) that attacked humans in Eastern Siberia (Irkutsk region, Russia). In total, 31,892 individual ticks were identified and analysed during the years 2007-2014. The majority (85.4%) of victims was bitten by I. persulcatus, 14.55% of attacks on humans were caused by D. nuttalli and D. silvarum, whereas H. concinna was documented only in 15 cases (0.05%). The seasonal activity and the age/gender structure of the tick population were studied as well. Among all the studied ticks, three unconventional species, i.e. Rhipicephalus sanguineus, Dermacentor reticulatus and Amblyomma americanum, were identified. Analysis of tick bite histories indicates at least three events of invasion of non-endemic ticks into the ecosystems of northern Eurasia with harsh continental climates. Invading ticks are able to reach the adult life stage and are aggressive to the local human population. Phylogenetic analysis of mt 16S rRNA gene fragments suggests multiple independent routes of tick migration to Eastern Siberia. Possible implications to human health and epidemiology of tick-borne infections are discussed. PMID:26443685

  12. Exposure to soil, house dust and decaying plants increases gut microbial diversity and decreases serum immunoglobulin E levels in BALB/c mice.

    PubMed

    Zhou, Dongrui; Zhang, Honglin; Bai, Zhimao; Zhang, Aidi; Bai, Futian; Luo, Xing; Hou, Yue; Ding, Xiao; Sun, Beili; Sun, Xiao; Ma, Ning; Wang, Cuifen; Dai, Xiaoniu; Lu, Zuhong

    2016-05-01

    To assess the impact of sanitation of a living environment on gut microbiota and development of the immune system, we raised BALB/c mice under three distinct environmental conditions: a specific pathogen-free animal room (SPF), a general animal room (XZ) and a farmhouse (JD). All other variables like diet, age, genetic background, physiological status and original gut microbiota were controlled for in the three groups. Using high-throughput sequencing of the 16S rRNA gene, we found that each mouse group had a specific structure of the gut microbial community. Groups JD and XZ harboured a significantly more diverse and richer gut microbiota than did group SPF. Bacteroidetes were significantly more abundant in groups XZ and JD than in group SPF, whereas Firmicutes showed the inverse pattern. Total serum immunoglobulin E (IgE) levels were significantly lower in groups XZ and JD than in group SPF. There were no significant differences in gut microbiota diversity and serum IgE concentration between groups JD and XZ, but we found higher abundance of dominant genera in the gut microflora of group JD. We conclude that exposure to soil, house dust and decaying plant material enhances gut microbial diversity and innate immunity. Our results seem to provide new evidence supporting the hygiene hypothesis. PMID:25958920

  13. Elimination of Arsenophonus and decrease in the bacterial symbionts diversity by antibiotic treatment leads to increase in fitness of whitefly, Bemisia tabaci.

    PubMed

    Raina, Harpreet Singh; Rawal, Vagisha; Singh, Shama; Daimei, Guisuibou; Shakarad, Mallikarjun; Rajagopal, Raman

    2015-06-01

    Bemisia tabaci is an invasive agricultural pest with more than 24 genetic groups harboring different bacterial endosymbionts categorized into obligatory and facultative endosymbionts. Arsenophonus is one of the facultative endosymbionts prevalent in B. tabaci of Indian sub-continent. Not much is known about the functional role of this endosymbiont in its host. Some studies have revealed its involvement in virus transmission by B. tabaci, but how it effects the biology of B. tabaci is unknown. In this study, tetracycline was used to eliminate Arsenophonus from B. tabaci to study its effects with regard to development and other fitness parameters. Bacteria specific 16S Polymerase chain reaction (PCR) was used to ascertain Arsenophonus absence with differential effects on other secondary endosymbionts present in B. tabaci. Our results revealed that Arsenophonus negative (A(-)) whiteflies had more fecundity, increased juvenile developmental time, increased nymphal survival and increased adult life span as compared to control (A(+)) whiteflies. Thus, our results demonstrate that A(+) whiteflies have lesser fitness as compared to A(-) whiteflies. These observations give a new insight about the probable role of Arsenophonus in B. tabaci, that need to be explored further. PMID:25801610

  14. 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...

  15. 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

  16. Rickettsia parkeri invasion of diverse host cells involves an Arp2/3 complex, WAVE complex and Rho-family GTPase-dependent pathway.

    PubMed

    Reed, Shawna C O; Serio, Alisa W; Welch, Matthew D

    2012-04-01

    Rickettsiae are obligate intracellular pathogens that are transmitted to humans by arthropod vectors and cause diseases such as spotted fever and typhus. Although rickettsiae require the host cell actin cytoskeleton for invasion, the cytoskeletal proteins that mediate this process have not been completely described. To identify the host factors important during cell invasion by Rickettsia parkeri, a member of the spotted fever group (SFG), we performed an RNAi screen targeting 105 proteins in Drosophila melanogaster S2R+ cells. The screen identified 21 core proteins important for invasion, including the GTPases Rac1 and Rac2, the WAVE nucleation-promoting factor complex and the Arp2/3 complex. In mammalian cells, including endothelial cells, the natural targets of R. parkeri, the Arp2/3 complex was also crucial for invasion, while requirements for WAVE2 as well as Rho GTPases depended on the particular cell type. We propose that R. parkeri invades S2R+ arthropod cells through a primary pathway leading to actin nucleation, whereas invasion of mammalian endothelial cells occurs via redundant pathways that converge on the host Arp2/3 complex. Our results reveal a key role for the WAVE and Arp2/3 complexes, as well as a higher degree of variation than previously appreciated in actin nucleation pathways activated during Rickettsia invasion. PMID:22188208

  17. How Should Beta-Diversity Inform Biodiversity Conservation?

    PubMed

    Socolar, Jacob B; Gilroy, James J; Kunin, William E; Edwards, David P

    2016-01-01

    To design robust protected area networks, accurately measure species losses, or understand the processes that maintain species diversity, conservation science must consider the organization of biodiversity in space. Central is beta-diversity--the component of regional diversity that accumulates from compositional differences between local species assemblages. We review how beta-diversity is impacted by human activities, including farming, selective logging, urbanization, species invasions, overhunting, and climate change. Beta-diversity increases, decreases, or remains unchanged by these impacts, depending on the balance of processes that cause species composition to become more different (biotic heterogenization) or more similar (biotic homogenization) between sites. While maintaining high beta-diversity is not always a desirable conservation outcome, understanding beta-diversity is essential for protecting regional diversity and can directly assist conservation planning. PMID:26701706

  18. Changes in hardwood forest understory plant communities in response to European earthworm invasions.

    PubMed

    Hale, Cindy M; Frelich, Lee E; Reich, Peter B

    2006-07-01

    European earthworms are colonizing earthworm-free northern hardwood forests across North America. Leading edges of earthworm invasion provide an opportunity to investigate the response of understory plant communities to earthworm invasion and whether the species composition of the earthworm community influences that response. Four sugar maple-dominated forest sites with active earthworm invasions were identified in the Chippewa National Forest in north central Minnesota, USA. In each site, we established a 30 x 150 m sample grid that spanned a visible leading edge of earthworm invasion and sampled earthworm populations and understory vegetation over four years. Across leading edges of earthworm invasion, increasing total earthworm biomass was associated with decreasing diversity and abundance of herbaceous plants in two of four study sites, and the abundance and density of tree seedlings decreased in three of four study sites. Sample points with the most diverse earthworm species assemblage, independent of biomass, had the lowest plant diversity. Changes in understory plant community composition were most affected by increasing biomass of the earthworm species Lumbricus rubellus. Where L. rubellus was absent there was a diverse community of native herbaceous plants, but where L. rubellus biomass reached its maximum, the herbaceous-plant community was dominated by Carex pensylvanica and Arisaema triphyllum and, in some cases, was completely absent. Evidence from these forest sites suggests that earthworm invasion can lead to dramatic changes in the understory community and that the nature of these changes is influenced by the species composition of the invading earthworm community. PMID:16922315

  19. Invasive blue mussels threaten regional scale genetic diversity in mainland and remote offshore locations: the need for baseline data and enhanced protection in the Southern Ocean.

    PubMed

    Gardner, Jonathan P A; Zbawicka, Małgorzata; Westfall, Kristen M; Wenne, Roman

    2016-09-01

    Human-mediated biological transfers of species have substantially modified many ecosystems with profound environmental and economic consequences. However, in many cases, invasion events are very hard to identify because of the absence of an appropriate baseline of information for receiving sites/regions. In this study, use of high-resolution genetic markers (single nucleotide polymorphisms - SNPs) highlights the threat of introduced Northern Hemisphere blue mussels (Mytilus galloprovincialis) at a regional scale to Southern Hemisphere lineages of blue mussels via hybridization and introgression. Analysis of a multispecies SNP dataset reveals hotspots of invasive Northern Hemisphere blue mussels in some mainland New Zealand locations, as well as the existence of unique native lineages of blue mussels on remote oceanic islands in the Southern Ocean that are now threatened by invasive mussels. Samples collected from an oil rig that has moved between South Africa, Australia, and New Zealand were identified as invasive Northern Hemisphere mussels, revealing the relative ease with which such non-native species may be moved from region to region. In combination, our results highlight the existence of unique lineages of mussels (and by extension, presumably of other taxa) on remote offshore islands in the Southern Ocean, the need for more baseline data to help identify bioinvasion events, the ongoing threat of hybridization and introgression posed by invasive species, and the need for greater protection of some of the world's last great remote areas. PMID:27124277

  20. 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…

  1. The Extent of Hybridization and Its Impact on the Genetic Diversity and Population Structure of an Invasive Tree, Ulmus Pumila (Ulmaceae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Siberian elm (Ulmus pumila L.), native to East Asia, was introduced in the U.S. in the 1900’s because of its high tolerance to Dutch elm disease (DED). Siberian elm has spread following its introduction and has now become one of the most invasive woody species in the U.S., alongside Russian olive a...

  2. An Invasive Mammal (the Gray Squirrel, Sciurus carolinensis) Commonly Hosts Diverse and Atypical Genotypes of the Zoonotic Pathogen Borrelia burgdorferi Sensu Lato

    PubMed Central

    Magierecka, Agnieszka; Gilbert, Lucy; Edoff, Alissa; Brereton, Amelia; Kilbride, Elizabeth; Denwood, Matt; Birtles, Richard; Biek, Roman

    2015-01-01

    Invasive vertebrate species can act as hosts for endemic pathogens and may alter pathogen community composition and dynamics. For the zoonotic pathogen Borrelia burgdorferi sensu lato, the agent of Lyme borreliosis, recent work shows invasive rodent species can be of high epidemiological importance and may support host-specific strains. This study examined the role of gray squirrels (Sciurus carolinensis) (n = 679), an invasive species in the United Kingdom, as B. burgdorferi sensu lato hosts. We found that gray squirrels were frequently infested with Ixodes ricinus, the main vector of B. burgdorferi sensu lato in the United Kingdom, and 11.9% were infected with B. burgdorferi sensu lato. All four genospecies that occur in the United Kingdom were detected in gray squirrels, and unexpectedly, the bird-associated genospecies Borrelia garinii was most common. The second most frequent infection was with Borrelia afzelii. Genotyping of B. garinii and B. afzelii produced no evidence for strains associated with gray squirrels. Generalized linear mixed models (GLMM) identified tick infestation and date of capture as significant factors associated with B. burgdorferi sensu lato infection in gray squirrels, with infection elevated in early summer in squirrels infested with ticks. Invasive gray squirrels appear to become infected with locally circulating strains of B. burgdorferi sensu lato, and further studies are required to determine their role in community disease dynamics. Our findings highlight the fact that the role of introduced host species in B. burgdorferi sensu lato epidemiology can be highly variable and thus difficult to predict. PMID:25888168

  3. EDAPHIC CONTROLS ON THE PHYTOCHEMISTRY OF THE INVASIVE PLANT ALLIARIA PETIOLATA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Alliaria petiolata (garlic mustard), an invasive species in temperate forests throughout North America, is associated with decreases in above and below ground species diversity and alterations to nutrient turnover. Garlic mustard produces a set of secondary chemicals in the glucosinolate family, sp...

  4. 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 ...

  5. AB173. TR4 nuclear receptor increases prostate cancer invasion via decreasing the miR-373-3p expression to alter TGFβR2/p-Smad3 signals

    PubMed Central

    Yang, Guosheng; Qiu, Xiaofo

    2016-01-01

    Objective Testicular nuclear receptor 4 (TR4) is a member of the nuclear receptor superfamily, which may play key roles to influence the metabolic diseases and prostate tumorigenesis. The purpose of our study is to elucidate the mechanisms how TR4 influences the prostate cancer (PCa) metastasis. Methods We constructed three different PCa cell lines including C4-2, PC3 and CWR22Rv1 with differential stable expression of TR4. RT-PCR and Western blot analysis were used to validate identified downstream genes. To explore the function of genes, we manipulated cells 2D and 3D invasion assays and mice experiment. Results we found TR4 could promote PCa cell invasion using two different cell invasion assays. Mechanism dissection revealed that TR4 might enhance PCa cell invasion via modulation of the microRNA-373-3p (miR-373-3p) expression. An interruption approach using miR-373-3p partially reversed TR4-enhanced PCa cell invasion. Furthermore, we found TR4-miR-373-3p might function through modulation of the TGFβR2/p-Smad3 signals to enhance the PCa cell invasion. The in vivo mouse model using orthotopic xenografted CWR22Rv1 cell line transfected with luciferase-reporter also confirmed in vitro cell line studies showing TR4 enhanced PCa metastasis via modulation of miR-373-3p. Conclusions Our data suggest that TR4 may represent a key player to influence the PCa metastasis and targeting TR4 miR-373-3p→ TGFβR2/p-Smad3 axis using TR4 antagonist or TR4-siRNA or miR-373-3p may become a new potential therapeutic approach to better suppress PCa metastasis.

  6. Uptake, outcomes, and costs of implementing non-invasive prenatal testing for Down’s syndrome into NHS maternity care: prospective cohort study in eight diverse maternity units

    PubMed Central

    Wright, David; Hill, Melissa; Verhoef, Talitha I; Daley, Rebecca; Lewis, Celine; Mason, Sarah; McKay, Fiona; Jenkins, Lucy; Howarth, Abigail; Cameron, Louise; McEwan, Alec; Fisher, Jane; Kroese, Mark; Morris, Stephen

    2016-01-01

    Objective To investigate the benefits and costs of implementing non-invasive prenatal testing (NIPT) for Down’s syndrome into the NHS maternity care pathway. Design Prospective cohort study. Setting Eight maternity units across the United Kingdom between 1 November 2013 and 28 February 2015. Participants All pregnant women with a current Down’s syndrome risk on screening of at least 1/1000. Main outcome measures Outcomes were uptake of NIPT, number of cases of Down’s syndrome detected, invasive tests performed, and miscarriages avoided. Pregnancy outcomes and costs associated with implementation of NIPT, compared with current screening, were determined using study data on NIPT uptake and invasive testing in combination with national datasets. Results NIPT was prospectively offered to 3175 pregnant women. In 934 women with a Down’s syndrome risk greater than 1/150, 695 (74.4%) chose NIPT, 166 (17.8%) chose invasive testing, and 73 (7.8%) declined further testing. Of 2241 women with risks between 1/151 and 1/1000, 1799 (80.3%) chose NIPT. Of 71 pregnancies with a confirmed diagnosis of Down’s syndrome, 13/42 (31%) with the diagnosis after NIPT and 2/29 (7%) after direct invasive testing continued, resulting in 12 live births. In an annual screening population of 698 500, offering NIPT as a contingent test to women with a Down’s syndrome screening risk of at least 1/150 would increase detection by 195 (95% uncertainty interval −34 to 480) cases with 3368 (2279 to 4027) fewer invasive tests and 17 (7 to 30) fewer procedure related miscarriages, for a non-significant difference in total costs (£−46 000, £−1 802 000 to £2 661 000). The marginal cost of NIPT testing strategies versus current screening is very sensitive to NIPT costs; at a screening threshold of 1/150, NIPT would be cheaper than current screening if it cost less than £256. Lowering the risk threshold increases the number of Down’s syndrome cases detected and

  7. 'Bigger data' on scale-dependent effects of invasive species on biodiversity cannot overcome confounded analyses: a comment on Stohlgren & Rejmánek (2014).

    PubMed

    Chase, Jonathan M; Powell, Kristin I; Knight, Tiffany M

    2015-08-01

    A recent study by Stohlgren & Rejmánek (SR: Stohlgren TJ, Rejmánek M. 2014 Biol. Lett. 10. (doi:10.1098/rsbl.2013.0939)) purported to test the generality of a recent finding of scale-dependent effects of invasive plants on native diversity; dominant invasive plants decreased the intercept and increased the slope of the species-area relationship. SR (2014) find little correlation between invasive species cover and the slopes and intercepts of SARs across a diversity of sites. We show that the analyses of SR (2014) are inappropriate because of confounding causality. PMID:26246332

  8. The Effects of Copper Pollution on Fouling Assemblage Diversity: A Tropical-Temperate Comparison

    PubMed Central

    Canning-Clode, João; Fofonoff, Paul; Riedel, Gerhardt F.; Torchin, Mark; Ruiz, Gregory M.

    2011-01-01

    Background The invasion of habitats by non-indigenous species (NIS) occurs at a global scale and can generate significant ecological, evolutionary, economic and social consequences. Estuarine and coastal ecosystems are particularly vulnerable to pollution from numerous sources due to years of human-induced degradation and shipping. Pollution is considered as a class of disturbance with anthropogenic roots and recent studies have concluded that high frequencies of disturbance may facilitate invasions by increasing the availability of resources. Methodology/Principal Findings To examine the effects of heavy metal pollution as disturbance in shaping patterns of exotic versus native diversity in marine fouling communities we exposed fouling communities to different concentrations of copper in one temperate (Virginia) and one tropical (Panama) region. Diversity was categorized as total, native and non-indigenous and we also incorporated taxonomic and functional richness. Our findings indicate that total fouling diversity decreased with increasing copper pollution, whether taxonomic or functional diversity is considered. Both native and non-indigenous richness decreased with increasing copper concentrations at the tropical site whereas at the temperate site, non-indigenous richness was too low to detect any effect. Conclusions/Significance Non-indigenous richness decreased with increasing metal concentrations, contradicting previous investigations that evaluate the influence of heavy metal pollution on diversity and invasibility of fouling assemblages. These results provide first insights on how the invasive species pool in a certain region may play a key role in the disturbance vs. non-indigenous diversity relationship. PMID:21437262

  9. First results on the genetic diversity of the invasive signal crayfish Pacifastacus leniusculus (Dana, 1852) in Europe using novel microsatellite loci.

    PubMed

    Froufe, E; Varandas, S; Teixeira, A; Sousa, R; Filipová, L; Petrusek, A; Edsman, L; Lopes-Lima, M

    2015-08-01

    The introduction of non-native crayfish in aquatic ecosystems is very common due to human activities (e.g. aquaculture, recreational and commercial fisheries). The signal crayfish, Pacifastacus leniusculus (Dana, 1852), is one of the most widespread invasive species in Europe. Although several important ecological and economic impacts of this species have been reported, its European population genetic characterisation has never been undertaken using nuclear markers. Thus, the aim of this study was to develop and characterise new microsatellite markers for signal crayfish that can be useful in future studies in its invaded range, since only five are available so far. In total, 93 individuals from four geographically distinct European populations (Portugal, Great Britain, Finland and Sweden) were scored for the new markers and for those previously described, with the Bayesian analysis revealing a clear distinction among populations. These markers are suitable for future studies of the population genetic structure of this important invasive species, by increasing information about the possible pathways of introduction and dispersal, and by giving insights about the most important vectors of introduction. PMID:25638230

  10. Comparison of genetic diversity of the invasive weed Rubus alceifolius poir. (Rosaceae) in its native range and in areas of introduction, using amplified fragment length polymorphism (AFLP) markers.

    PubMed

    Amsellem, L; Noyer, J L; Le Bourgeois, T; Hossaert-McKey, M

    2000-04-01

    Theory predicts that colonization of new areas will be associated with population bottlenecks that reduce within-population genetic diversity and increase genetic differentiation among populations. This should be especially true for weedy plant species, which are often characterized by self-compatible breeding systems and vegetative propagation. To test this prediction, and to evaluate alternative scenarios for the history of introduction, the genetic diversity of Rubus alceifolius was studied with amplified fragment length polymorphism (AFLP) markers in its native range in southeast Asia and in several areas where this plant has been introduced and is now a serious weed (Indian Ocean islands, Australia). In its native range, R. alceifolius showed great genetic variability within populations and among geographically close populations (populations sampled ranging from northern Vietnam to Java). In Madagascar, genetic variability was somewhat lower than in its native range, but still considerable. Each population sampled in the other Indian Ocean islands (Mayotte, La Réunion, Mauritius) was characterized by a single different genotype of R. alceifolius for the markers studied, and closely related to individuals from Madagascar. Queensland populations also included only a single genotype, identical to that found in Mauritius. These results suggest that R. alceifolius was first introduced into Madagascar, perhaps on multiple occasions, and that Madagascan individuals were the immediate source of plants that colonized other areas of introduction. Successive nested founder events appear to have resulted in cumulative reduction in genetic diversity. Possible explanations for the monoclonality of R. alceifolius in many areas of introduction are discussed. PMID:10736047

  11. Species richness and interacting factors control invasibility of a marine community

    PubMed Central

    Marraffini, M. L.; Geller, J. B.

    2015-01-01

    Anthropogenic vectors have moved marine species around the world leading to increased invasions and expanded species' ranges. The biotic resistance hypothesis of Elton (in The ecology of invasions by animals and plants, 1958) predicts that more diverse communities should have greater resistance to invasions, but experiments have been equivocal. We hypothesized that species richness interacts with other factors to determine experimental outcomes. We manipulated species richness, species composition (native and introduced) and availability of bare space in invertebrate assemblages in a marina in Monterey, CA. Increased species richness significantly interacted with both initial cover of native species and of all organisms to collectively decrease recruitment. Although native species decreased recruitment, introduced species had a similar effect, and we concluded that biotic resistance is conferred by total species richness. We suggest that contradictory conclusions in previous studies about the role of diversity in regulating invasions reflect uncontrolled variables in those experiments that modified the effect of species richness. Our results suggest that patches of low diversity and abundance may facilitate invasions, and that such patches, once colonized by non-indigenous species, can resist both native and non-indigenous species recruitment. PMID:26203005

  12. Radiotherapy Can Decrease Locoregional Recurrence and Increase Survival in Mastectomy Patients With T1 to T2 Breast Cancer and One to Three Positive Nodes With Negative Estrogen Receptor and Positive Lymphovascular Invasion Status

    SciTech Connect

    Yang, P.S.; Chen, C.M.; Liu, M.C.; Jian, J.M.; Horng, C.F.; Liu, M.J.; Yu, B.L.; Lee, M.Y.; Chi, C.W.

    2010-06-01

    Purpose: To define a subgroup of patients at high risk of locoregional recurrence (LRR) who might be benefit from postmastectomy radiotherapy in invasive breast cancer and tumor size <5 cm with one to three involved axillary lymph nodes (T1-2 N1). Methods and Materials: Between April 1991 and December 2005, 544 patients with T1-2 N1 invasive breast cancer were treated with modified radical mastectomy. Of the 544 patients, 383 patients (70.4%) had no radiotherapy, and 161 patients (29.6%) received radiotherapy. We retrospectively compared these two patient groups. Results: With a median follow-up of 40.3 months, LRR occurred in 40 (7.4%) of 544 patients. On univariate analysis, high nuclear grade (p = 0.04), negative estrogen receptor (ER) status (p = 0.001), presence of lymphovascular invasion (LVI) (p = 0.003), and no radiotherapy (p = 0.0015) were associated with a significantly higher rate of LRR. Negative ER status (hazard ratio = 5.1) and presence of LVI (hazard ratio = 2.5) were the risk factors for LRR with statistical significance in the multivariate analysis. Radiotherapy reduced the LRR in patients with the following characteristics: age <40 years, T2 stage, high nuclear grade, negative ER status, and presence of LVI. For 41 patients with negative ER and positive LVI status, radiotherapy can reduce LRR from 10 of 25 (40%) to 2 of 16 (12.5%) and increase the 5-year overall survival from 43.7% to 87.1%. Conclusion: Radiotherapy can reduce LRR and increase survival in T1-2 N1 breast cancer patients with negative ER status and presence of LVI.

  13. Genetic Diversity of the Invasive Gall Wasp Leptocybe invasa (Hymenoptera: Eulophidae) and of its Rickettsia Endosymbiont, and Associated Sex-Ratio Differences

    PubMed Central

    Nugnes, Francesco; Gebiola, Marco; Monti, Maurilia Maria; Gualtieri, Liberata; Giorgini, Massimo; Wang, Jianguo; Bernardo, Umberto

    2015-01-01

    The blue-gum chalcid Leptocybe invasa Fisher & LaSalle (Hymenoptera: Eulophidae) is a gall wasp pest of Eucalyptus species, likely native to Australia. Over the past 15 years it has invaded 39 countries on all continents where eucalypts are grown. The worldwide invasion of the blue gum chalcid was attributed to a single thelytokous morphospecies formally described in 2004. Subsequently, however, males have been recorded in several countries and the sex ratio of field populations has been found to be highly variable in different areas. In order to find an explanation for such sex ratio differences, populations of L. invasa from a broad geographical area were screened for the symbionts currently known as reproductive manipulators, and both wasps and symbionts were genetically characterized using multiple genes. Molecular analyses suggested that L. invasa is in fact a complex of two cryptic species involved in the rapid and efficient spread of the wasp, the first recovered from the Mediterranean region and South America, the latter from China. All screened specimens were infected by endosymbiotic bacteria belonging to the genus Rickettsia. Two closely related Rickettsia strains were found, each infecting one of the two putative cryptic species of L. invasa and associated with different average sex ratios. Rickettsia were found to be localized in the female reproductive tissues and transovarially transmitted, suggesting a possible role of Rickettsia as the causal agent of thelytokous parthenogenesis in L. invasa. Implications for the variation of sex ratio and for the management of L. invasa are discussed. PMID:25970681

  14. 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

  15. INVASIVE PLANTS HARBOR HUNGRY DETRITIVORES THAT ALTER ECOSYSTEM FUNCTION

    EPA Science Inventory

    Ecosystems are expected to function more efficiently in response to a diverse community of inhabitants. However, biological invasions may change expected relationships between ecosystem function and diversity. We observed increased decomposition, a measure of ecosystem function...

  16. 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

  17. Global ecological impacts of invasive species in aquatic ecosystems.

    PubMed

    Gallardo, Belinda; Clavero, Miguel; Sánchez, Marta I; Vilà, Montserrat

    2016-01-01

    The introduction of invasive species, which often differ functionally from the components of the recipient community, generates ecological impacts that propagate along the food web. This review aims to determine how consistent the impacts of aquatic invasions are across taxa and habitats. To that end, we present a global meta-analysis from 151 publications (733 cases), covering a wide range of invaders (primary producers, filter collectors, omnivores and predators), resident aquatic community components (macrophytes, phytoplankton, zooplankton, benthic invertebrates and fish) and habitats (rivers, lakes and estuaries). Our synthesis suggests a strong negative influence of invasive species on the abundance of aquatic communities, particularly macrophytes, zooplankton and fish. In contrast, there was no general evidence for a decrease in species diversity in invaded habitats, suggesting a time lag between rapid abundance changes and local extinctions. Invaded habitats showed increased water turbidity, nitrogen and organic matter concentration, which are related to the capacity of invaders to transform habitats and increase eutrophication. The expansion of invasive macrophytes caused the largest decrease in fish abundance, the filtering activity of filter collectors depleted planktonic communities, omnivores (including both facultative and obligate herbivores) were responsible for the greatest decline in macrophyte abundance, and benthic invertebrates were most negatively affected by the introduction of new predators. These impacts were relatively consistent across habitats and experimental approaches. Based on our results, we propose a framework of positive and negative links between invasive species at four trophic positions and the five different components of recipient communities. This framework incorporates both direct biotic interactions (predation, competition, grazing) and indirect changes to the water physicochemical conditions mediated by invaders (habitat

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

    NASA Astrophysics Data System (ADS)

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

    2014-11-01

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

  19. Eco-immunology of fish invasions: the role of MHC variation.

    PubMed

    Monzón-Argüello, C; Garcia de Leaniz, C; Gajardo, G; Consuegra, S

    2014-06-01

    The relationship between invaders and the pathogens encountered in their new environment can have a large effect on invasion success. Invaders can become free from their natural pathogens and reallocate costly immune resources to growth and reproduction, thereby increasing invasion success. Release from enemies and relaxation of selective pressures could render newly founded populations more variable at immune-related genes, such as the major histocompatibility complex (MHC), particularly when they have different origins. Using rainbow and brown trout, two of the world's most successful fish invaders, we tested the general hypothesis that invaders should display high intrapopulation immunogenetic diversity and interpopulation divergence, due to the interplay between genetic drift and successive waves of genetically divergent introductions. We analysed genetic diversity and signatures of selection at the MHC class II β immune-related locus. In both species, MHC diversity (allelic richness and heterozygosity) for southern hemisphere populations was similar to values reported for populations at their native range. However, MHC functional diversity was limited, and population immunogenetic structuring weaker than that observed using neutral markers. Depleted MHC functional diversity could reflect a decrease in immune response, immune-related assortative mating or selection for resistance to newly encountered parasites. Given that the role of MHC diversity in the survival of these populations remains unclear, depleted functional diversity of invasive salmonids could compromise their long-term persistence. A better understanding of the eco-immunology of invaders may help in managing and preventing the impact of biological invasions, a major cause of loss of biodiversity worldwide. PMID:24752816

  20. Negative Effects of an Exotic Grass Invasion on Small-Mammal Communities

    PubMed Central

    Freeman, Eric D.; Sharp, Tiffanny R.; Larsen, Randy T.; Knight, Robert N.; Slater, Steven J.; McMillan, Brock R.

    2014-01-01

    Exotic invasive species can directly and indirectly influence natural ecological communities. Cheatgrass (Bromus tectorum) is non-native to the western United States and has invaded large areas of the Great Basin. Changes to the structure and composition of plant communities invaded by cheatgrass likely have effects at higher trophic levels. As a keystone guild in North American deserts, granivorous small mammals drive and maintain plant diversity. Our objective was to assess potential effects of invasion by cheatgrass on small-mammal communities. We sampled small-mammal and plant communities at 70 sites (Great Basin, Utah). We assessed abundance and diversity of the small-mammal community, diversity of the plant community, and the percentage of cheatgrass cover and shrub species. Abundance and diversity of the small-mammal community decreased with increasing abundance of cheatgrass. Similarly, cover of cheatgrass remained a significant predictor of small-mammal abundance even after accounting for the loss of the shrub layer and plant diversity, suggesting that there are direct and indirect effects of cheatgrass. The change in the small-mammal communities associated with invasion of cheatgrass likely has effects through higher and lower trophic levels and has the potential to cause major changes in ecosystem structure and function. PMID:25269073

  1. Negative effects of an exotic grass invasion on small-mammal communities.

    PubMed

    Freeman, Eric D; Sharp, Tiffanny R; Larsen, Randy T; Knight, Robert N; Slater, Steven J; McMillan, Brock R

    2014-01-01

    Exotic invasive species can directly and indirectly influence natural ecological communities. Cheatgrass (Bromus tectorum) is non-native to the western United States and has invaded large areas of the Great Basin. Changes to the structure and composition of plant communities invaded by cheatgrass likely have effects at higher trophic levels. As a keystone guild in North American deserts, granivorous small mammals drive and maintain plant diversity. Our objective was to assess potential effects of invasion by cheatgrass on small-mammal communities. We sampled small-mammal and plant communities at 70 sites (Great Basin, Utah). We assessed abundance and diversity of the small-mammal community, diversity of the plant community, and the percentage of cheatgrass cover and shrub species. Abundance and diversity of the small-mammal community decreased with increasing abundance of cheatgrass. Similarly, cover of cheatgrass remained a significant predictor of small-mammal abundance even after accounting for the loss of the shrub layer and plant diversity, suggesting that there are direct and indirect effects of cheatgrass. The change in the small-mammal communities associated with invasion of cheatgrass likely has effects through higher and lower trophic levels and has the potential to cause major changes in ecosystem structure and function. PMID:25269073

  2. Potential reversal of a phase shift: the rapid decrease in the cover of the invasive green macroalga Dictyosphaeria cavernosa Forsskål on coral reefs in Kāne`ohe Bay, Oahu, Hawai`i

    NASA Astrophysics Data System (ADS)

    Stimson, J.; Conklin, E.

    2008-12-01

    The native green macroalga Dictyosphaeria cavernosa dominated most of the reef slope habitat in Kāne‘ohe Bay, Hawai‘i for 40 years prior to 2006 and had displaced corals from the habitats they created. This has been one of the most oft-cited examples of a phase shift occurring on a coral reef. After decades of relatively constant, high abundance of the alga, percent cover declined dramatically throughout the bay between February and June 2006. The sudden decrease in cover of this alga appears to be the result of an unusually protracted cloudy, rainy period in March 2006, which may have reduced irradiance and caused the alga to lose weight. Corals and red macroalgae living at the same depths and in some of the same habitats were apparently not affected by this 42-day period of rain and overcast skies. Competition between corals and D. cavernosa for space on reef slopes has been virtually eliminated by the death of this alga, but the unstable rubble formations, which remain in much of the area formerly covered by D. cavernosa may not be conducive to rapid increase in cover by the remaining corals or to establishment by coral recruits. Two years later, there was still no recovery of D. cavernosa. This represents a rare example of decline in macroalgal dominance on a reef and a partial reversal, possibly only temporary, of a phase shift.

  3. Eukaryotic Cell Invasion does not correlate to flaA SVR Sequence Type based on a Library of Genetically Diverse Campylobacter jejuni Isolates Originally Recovered from A Variety of Sources in Iceland

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Introduction: Campylobacter spp. are considered to be a leading bacterial etiologic agent of acute food-borne gastroenteritis among human populations. Epithelial cell invasion is hypothesized to be necessary for human infection and cell invasion assays have been utilized to demonstrate that distinc...

  4. Diverse Thinking about Diversity

    ERIC Educational Resources Information Center

    Kaplan, Sandra N.

    2013-01-01

    This article focuses on the concept of diversity in educational decision making. It is noted that the differences that distinguish the needs, interests and abilities are identified by educators. It lists misconceptions resulting from not attending to within-group diversity, and states that a "loss of self" for individual members of…

  5. The making of a rapid plant invader: genetic diversity and differentiation in the native and invaded range of Senecio inaequidens.

    PubMed

    Lachmuth, Susanne; Durka, Walter; Schurr, Frank M

    2010-09-01

    To become invasive, exotic species have to succeed in the consecutive phases of introduction, naturalization, and invasion. Each of these phases leaves traces in genetic structure, which may affect the species' success in subsequent phases. We examined this interplay of genetic structure and invasion dynamics in the South African Ragwort (Senecio inaequidens), one of Europe's fastest plant invaders. We used AFLP and microsatellite markers to analyze 19 native African and 32 invasive European populations. In combination with historic data, we distinguished invasion routes and traced them back to the native source areas. This revealed that different introduction sites had markedly different success in the three invasion phases. Notably, an observed lag-phase in Northern Germany was evidently not terminated by factors increasing the invasiveness of the resident population but by invasive spread from another introduction centre. The lineage invading Central Europe was introduced to sites in which winters are more benign than in the native source region. Subsequently, this lineage spread into areas in which winter temperatures match the native climate more closely. Genetic diversity clearly increases with population age in Europe and less clearly decreases with spread rate up to population establishment. This indicates that gene flow along well-connected invasion routes counteracted losses of genetic diversity during rapid spread. In summary, this study suggests that multiple introductions, environmental preadaptation and high gene flow along invasion routes contributed to the success of this rapid invader. More generally, it demonstrates the benefit of combining genetic, historical, and climatic data for understanding biological invasions. PMID:20854275

  6. Climate-driven diversity loss in a grassland community.

    PubMed

    Harrison, Susan P; Gornish, Elise S; Copeland, Stella

    2015-07-14

    Local ecological communities represent the scale at which species coexist and share resources, and at which diversity has been experimentally shown to underlie stability, productivity, invasion resistance, and other desirable community properties. Globally, community diversity shows a mixture of increases and decreases over recent decades, and these changes have relatively seldom been linked to climatic trends. In a heterogeneous California grassland, we documented declining plant diversity from 2000 to 2014 at both the local community (5 m(2)) and landscape (27 km(2)) scales, across multiple functional groups and soil environments. Communities became particularly poorer in native annual forbs, which are present as small seedlings in midwinter; within native annual forbs, community composition changed toward lower representation of species with a trait indicating drought intolerance (high specific leaf area). Time series models linked diversity decline to the significant decrease in midwinter precipitation. Livestock grazing history, fire, succession, N deposition, and increases in exotic species could be ruled out as contributing causes. This finding is among the first demonstrations to our knowledge of climate-driven directional loss of species diversity in ecological communities in a natural (nonexperimental) setting. Such diversity losses, which may also foreshadow larger-scale extinctions, may be especially likely in semiarid regions that are undergoing climatic trends toward higher aridity and lower productivity. PMID:26100891

  7. Climate-driven diversity loss in a grassland community

    PubMed Central

    Harrison, Susan P.; Gornish, Elise S.; Copeland, Stella

    2015-01-01

    Local ecological communities represent the scale at which species coexist and share resources, and at which diversity has been experimentally shown to underlie stability, productivity, invasion resistance, and other desirable community properties. Globally, community diversity shows a mixture of increases and decreases over recent decades, and these changes have relatively seldom been linked to climatic trends. In a heterogeneous California grassland, we documented declining plant diversity from 2000 to 2014 at both the local community (5 m2) and landscape (27 km2) scales, across multiple functional groups and soil environments. Communities became particularly poorer in native annual forbs, which are present as small seedlings in midwinter; within native annual forbs, community composition changed toward lower representation of species with a trait indicating drought intolerance (high specific leaf area). Time series models linked diversity decline to the significant decrease in midwinter precipitation. Livestock grazing history, fire, succession, N deposition, and increases in exotic species could be ruled out as contributing causes. This finding is among the first demonstrations to our knowledge of climate-driven directional loss of species diversity in ecological communities in a natural (nonexperimental) setting. Such diversity losses, which may also foreshadow larger-scale extinctions, may be especially likely in semiarid regions that are undergoing climatic trends toward higher aridity and lower productivity. PMID:26100891

  8. 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

  9. 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 ...

  10. Minimally Invasive Cardiovascular Surgery: Incisions and Approaches

    PubMed Central

    Langer, Nathaniel B.; Argenziano, Michael

    2016-01-01

    Throughout the modern era of cardiac surgery, most operations have been performed via median sternotomy with cardiopulmonary bypass. This paradigm is changing, however, as cardiovascular surgery is increasingly adopting minimally invasive techniques. Advances in patient evaluation, instrumentation, and operative technique have allowed surgeons to perform a wide variety of complex operations through smaller incisions and, in some cases, without cardiopulmonary bypass. With patients desiring less invasive operations and the literature supporting decreased blood loss, shorter hospital length of stay, improved postoperative pain, and better cosmesis, minimally invasive cardiac surgery should be widely practiced. Here, we review the incisions and approaches currently used in minimally invasive cardiovascular surgery. PMID:27127555

  11. [Invasive yeast infections in neutropenic patients].

    PubMed

    Ruiz Camps, Isabel; Jarque, Isidro

    2016-01-01

    Invasive fungal diseases caused by yeasts still play an important role in the morbidity and mortality in neutropenic patients with haematological malignancies. Although the overall incidence of invasive candidiasis has decreased due to widespread use of antifungal prophylaxis, the incidence of non-Candida albicans Candida species is increasing compared with that of C.albicans, and mortality of invasive candidiasis continues to be high. In addition, there has been an increase in invasive infections caused by an array of uncommon yeasts, including species of the genus Malassezia, Rhodotorula, Trichosporon and Saprochaete, characterised by their resistance to echinocandins and poor prognosis. PMID:27395023

  12. 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

  13. 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

  14. Managing diversity.

    PubMed

    Epting, L A; Glover, S H; Boyd, S D

    1994-06-01

    The U.S. work force is becoming increasingly diverse as the 20th century approaches. Statistics prove that most organizations are experiencing gender, culture, and age diversity within their labor forces. All managers and leaders must accept this diversity and work to handle it effectively. This article examines the current literature concerning management of diversity and its implications for the health care profession. Gender, culture, and age diversity and the potential problems that may arise with each are also addressed. Reasons to manage diversity are offered, as well as methods of managing diversity for both the manager and the chief executive officer. PMID:10134144

  15. Effects of PCV7 and PCV13 on invasive pneumococcal disease and carriage in Stockholm, Sweden.

    PubMed

    Galanis, Ilias; Lindstrand, Ann; Darenberg, Jessica; Browall, Sarah; Nannapaneni, Priyanka; Sjöström, Karin; Morfeldt, Eva; Naucler, Pontus; Blennow, Margareta; Örtqvist, Åke; Henriques-Normark, Birgitta

    2016-04-01

    The effects of pneumococcal conjugated vaccines (PCVs) need to be investigated. In Stockholm County, Sweden, PCV7 was introduced in the childhood immunisation programme in 2007 and changed to PCV13 in 2010.Over 90% of all invasive isolates during 2005-2014 (n=2336) and carriage isolates, 260 before and 647 after vaccine introduction, were characterised by serotyping, molecular typing and antibiotic susceptibility, and serotype diversity was calculated. Clinical information was collected for children and adults with invasive pneumococcal disease (IPD).The IPD incidence decreased post-PCV7, but not post-PCV13, in vaccinated children. Beneficial herd effects were seen in older children and adults, but not in the elderly. The herd protection was more pronounced post-PCV7 than post-PCV13. PCV7 serotypes decreased. IPD caused by PCV13 serotypes 3 and 19A increased post-PCV7. Post-PCV13, serotypes 6A and 19A, but not serotype 3, decreased. The serotype distribution changed in carriage and IPD to nonvaccine types, also in nonvaccinated populations. Expansion of non-PCV13 serotypes was largest following PCV13 introduction. Serotype diversity increased and nonvaccine clones emerged, such as CC433 (serotype 22F) in IPD and CC62 (serotype 11A) in carriage. In young children, meningitis, septicaemia and severe rhinosinusitis, but not bacteraemic pneumonia, decreased.Pneumococcal vaccination leads to expansion of new or minor serotypes/clones, also in nonvaccinated populations. PMID:26797033

  16. Effects of PCV7 and PCV13 on invasive pneumococcal disease and carriage in Stockholm, Sweden

    PubMed Central

    Galanis, Ilias; Lindstrand, Ann; Darenberg, Jessica; Browall, Sarah; Nannapaneni, Priyanka; Sjöström, Karin; Morfeldt, Eva; Naucler, Pontus; Blennow, Margareta; Örtqvist, Åke

    2016-01-01

    The effects of pneumococcal conjugated vaccines (PCVs) need to be investigated. In Stockholm County, Sweden, PCV7 was introduced in the childhood immunisation programme in 2007 and changed to PCV13 in 2010. Over 90% of all invasive isolates during 2005–2014 (n=2336) and carriage isolates, 260 before and 647 after vaccine introduction, were characterised by serotyping, molecular typing and antibiotic susceptibility, and serotype diversity was calculated. Clinical information was collected for children and adults with invasive pneumococcal disease (IPD). The IPD incidence decreased post-PCV7, but not post-PCV13, in vaccinated children. Beneficial herd effects were seen in older children and adults, but not in the elderly. The herd protection was more pronounced post-PCV7 than post-PCV13. PCV7 serotypes decreased. IPD caused by PCV13 serotypes 3 and 19A increased post-PCV7. Post-PCV13, serotypes 6A and 19A, but not serotype 3, decreased. The serotype distribution changed in carriage and IPD to nonvaccine types, also in nonvaccinated populations. Expansion of non-PCV13 serotypes was largest following PCV13 introduction. Serotype diversity increased and nonvaccine clones emerged, such as CC433 (serotype 22F) in IPD and CC62 (serotype 11A) in carriage. In young children, meningitis, septicaemia and severe rhinosinusitis, but not bacteraemic pneumonia, decreased. Pneumococcal vaccination leads to expansion of new or minor serotypes/clones, also in nonvaccinated populations. PMID:26797033

  17. Diversity: a grazier's best friend

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Biodiversity is a hot topic, but can understanding biodiversity help with pasture management? A diverse pasture may use resources more efficiently, extend the grazing season longer, resist weed invasion, and be more successful in stressful conditions. Animal production can be as good or better on a ...

  18. [Influences of Solenopsis invicta buren invasion on the native ant communities in different habitats in Guangdong].

    PubMed

    Wu, Bi-qiu; Lu, Yong-yue; Zeng, Ling; Liang, Guang-wen

    2008-01-01

    By using pitfall and bait traps, an investigation was made on the diversity and similarity of ant communities in the areas infested and un-infested with Solenopsis invicta Buren in Shenzhen of Guangdong. The results showed that under the invasion of S. invicta, the ant species number in lawn and wasteland reduced obviously, with a decrease of 6 in lawn and 3 in wasteland, and the native dominant ant species in lichee orchard, especially in wasteland and lawn, were replaced by S. invicta. With the infestation of S. invicta, the diversity and evenness of ant communities in wasteland and lawn decreased but the predominance increased obviously, while it was in adverse in lichee orchard. The similarity coefficients of the ant communities between S. invicta infested and un-infested lichee orchard, wasteland and lawn were 0.6316, 0.5882 and 0.2941, respectively. PMID:18419088

  19. Cardiac Output Assessed by Invasive and Minimally Invasive Techniques

    PubMed Central

    Lee, Allison J.; Cohn, Jennifer Hochman; Ranasinghe, J. Sudharma

    2011-01-01

    Cardiac output (CO) measurement has long been considered essential to the assessment and guidance of therapeutic decisions in critically ill patients and for patients undergoing certain high-risk surgeries. Despite controversies, complications and inherent errors in measurement, pulmonary artery catheter (PAC) continuous and intermittent bolus techniques of CO measurement continue to be the gold standard. Newer techniques provide less invasive alternatives; however, currently available monitors are unable to provide central circulation pressures or true mixed venous saturations. Esophageal Doppler and pulse contour monitors can predict fluid responsiveness and have been shown to decrease postoperative morbidity. Many minimally invasive techniques continue to suffer from decreased accuracy and reliability under periods of hemodynamic instability, and so few have reached the level of interchangeability with the PAC. PMID:21776254

  20. Temporal Genetic Dynamics of an Invasive Species, Frankliniella occidentalis (Pergande), in an Early Phase of Establishment

    PubMed Central

    Yang, Xian-Ming; Lou, Heng; Sun, Jing-Tao; Zhu, Yi-Ming; Xue, Xiao-Feng; Hong, Xiao-Yue

    2015-01-01

    Many species can successfully colonize new areas despite their propagules having low genetic variation. We assessed whether the decreased genetic diversity could result in temporal fluctuations of genetic parameters of the new populations of an invasive species, western flower thrips, Frankliniella occidentalis, using mitochondrial and microsatellite markers. This study was conducted in eight localities from four climate regions in China, where F. occidentalis was introduced in the year 2000 and had lower genetic diversity than its native populations. We also tested the level of genetic differentiation in these introduced populations. The genetic diversity of the samples at different years in the same locality was not significantly different from each other in most localities. FST and STRUCTURE analysis also showed that most temporal population comparisons from the same sites were not significantly differentiated. Our results showed that the invasive populations of F. occidentalis in China can maintain temporal stability in genetic composition at an early phase of establishment despite having lower genetic diversity than in their native range. PMID:26138760

  1. Temporal Genetic Dynamics of an Invasive Species, Frankliniella occidentalis (Pergande), in an Early Phase of Establishment.

    PubMed

    Yang, Xian-Ming; Lou, Heng; Sun, Jing-Tao; Zhu, Yi-Ming; Xue, Xiao-Feng; Hong, Xiao-Yue

    2015-01-01

    Many species can successfully colonize new areas despite their propagules having low genetic variation. We assessed whether the decreased genetic diversity could result in temporal fluctuations of genetic parameters of the new populations of an invasive species, western flower thrips, Frankliniella occidentalis, using mitochondrial and microsatellite markers. This study was conducted in eight localities from four climate regions in China, where F. occidentalis was introduced in the year 2000 and had lower genetic diversity than its native populations. We also tested the level of genetic differentiation in these introduced populations. The genetic diversity of the samples at different years in the same locality was not significantly different from each other in most localities. FST and STRUCTURE analysis also showed that most temporal population comparisons from the same sites were not significantly differentiated. Our results showed that the invasive populations of F. occidentalis in China can maintain temporal stability in genetic composition at an early phase of establishment despite having lower genetic diversity than in their native range. PMID:26138760

  2. Mechanobiology of tumor invasion: engineering meets oncology

    PubMed Central

    Carey, Shawn P.; D’Alfonso, Timothy M.; Shin, Sandra J.; Reinhart-King, Cynthia A.

    2011-01-01

    The physical sciences and engineering have introduced novel perspectives into the study of cancer through model systems, tools, and metrics that enable integration of basic science observations with clinical data. These methods have contributed to the identification of several overarching mechanisms that drive processes during cancer progression including tumor growth, angiogenesis, and metastasis. During tumor cell invasion – the first clinically observable step of metastasis – cells demonstrate diverse and evolving physical phenotypes that cannot typically be defined by any single molecular mechanism, and mechanobiology has been used to study the physical cell behaviors that comprise the “invasive phenotype”. In this review, we discuss the continually evolving pathological characterization and in vitro mechanobiological characterization of tumor invasion, with emphasis on emerging physical biology and mechanobiology strategies that have contributed to a more robust mechanistic understanding of tumor cell invasion. These physical approaches may ultimately help to better predict and identify tumor metastasis. PMID:22178415

  3. Ecosystem engineers modulate exotic invasions in riparian plant communities

    NASA Astrophysics Data System (ADS)

    Corenblit, D.; Tabacchi, E.; Steiger, J.; Gonzales, E.; Planty-Tabacchi, A. M.

    2012-04-01

    The relationship between biodiversity and invasibility of exotic plant species within different environments and at different spatial scales is still being discussed amongst scientists. In this study, patterns of native and exotic plant species richness and cover were examined in relation with ecosystem engineer effects of pioneer vegetation within the active tract of the Mediterranean gravel bed river Tech, South France. The floristic composition was characterized according to two distinct vegetation types corresponding to two habitats with contrasted conditions: (i) open and exposed alluvial bars dominated by herbaceous communities and (ii) islands and river margins partly stabilized by ecosystem engineer plants, disconnected from annual hydrogeomorphic disturbances, and covered by woody vegetation. A significant positive correlation between exotic and native plant species richness and cover was observed for the herbaceous and the woody types, indicating that both native and exotic richness benefit from the prevailing environmental conditions. However, significant differences in native and exotic specific richness and cover were found between these two vegetation types. Higher values of total species richness and Shannon diversity of native and exotic species were attained within the herbaceous vegetation type compared to the woody type. These differences may be related to changes in local exposure to hydrogeomorphic disturbances driven by engineer plant species, and to vegetation succession. A lower exotic cover within the woody vegetation type compared to the herbaceous type suggested an increase of resistance to invasion by exotic species during the biogeomorphic succession. The engineer effects of woody vegetation resulted in a decrease of alpha (α) diversity at patch scale but, in parallel, caused an increase in gamma (γ) diversity at the scale of the studied river segment. Our study corroborates recent investigations that support the theory of biotic

  4. Instructional Diversity.

    ERIC Educational Resources Information Center

    Samples, Bob

    2000-01-01

    Explains how learning occurs in the brain, specifically in the limbic system. Compares traditional teaching methods and diverse learning modes. Describes the characteristics of diverse instructional approaches. First published in 1994. (YDS)

  5. 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.

  6. Rethinking Diversity.

    ERIC Educational Resources Information Center

    Gordon, Jack

    1992-01-01

    Managing diversity is about coping with unassimilated differences, about building systems and a culture that unite different people in a common pursuit without undermining their diversity. The goal of diversity training is a high performance organization rather than a climate in which no one's feathers are ruffled. (SK)

  7. 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

  8. Production of Early Diploid Males by European Colonies of the Invasive Hornet Vespa velutina nigrithorax

    PubMed Central

    Darrouzet, Eric; Gévar, Jérémy; Guignard, Quentin; Aron, Serge

    2015-01-01

    The invasive yellow-legged hornet Vespa velutina nigrithorax was accidentally introduced in Europe in the early 2000s. As is the case in colonies of other wasp and hornet species, V. velutina colonies are known to produce sexuals (males and new queens) at the end of the summer. We show that early-stage colonies in French populations frequently produce males well before the usual reproductive period. The vast majority of the males produced are diploid, which is consistent with the loss of genetic diversity previously reported in introduced populations in France. Since males do not participate in colony activities, the production of early diploid males at the expense of workers is expected to hamper colony growth and, ultimately, decrease the expansion of the species in its invasive range in Europe. PMID:26414951

  9. Lianas as invasive species in North America: Chapter 28

    USGS Publications Warehouse

    Leicht-Young, Stacey A.; Pavlovic, Noel B.

    2015-01-01

    Liana diversity is typically low in the temperate zones; however, the influx of non-native invasive liana species in North America has increased local diversity at the expense of native habitats and species. Some of the most illustrative studies of invasive lianas in temperate North America compared the biological traits of invasive lianas with native congeners or ecological analogs. The majority of these studies focused on two species, Celastrus orbiculatus (oriental bittersweet) and Lonicera japonica (Japanese honeysuckle). Temperate zone lianas generally have higher photosynthetic rates than other early successional species and their host trees. Invasive lianas are having an increasing impact on the dynamics and trajectories of North American plant communities. They often exhibit superior growth and survival compared to their native counterparts, and in some cases, invasive lianas may directly contribute to the decline of their native correlates.

  10. Population genetics of the invasive cryptogenic anemone, Anemonia alicemartinae, along the southeastern Pacific coast

    NASA Astrophysics Data System (ADS)

    Canales-Aguirre, C. B.; Quiñones, A.; Hernández, C. E.; Neill, P. E.; Brante, A.

    2015-08-01

    One of the most important issues in biological invasions is understanding the factors and mechanisms determining the invasion success of non-native species. Theoretical and empirical works have shown that genetic diversity is a determinant of invasion success; thus, studying spatial patterns of genetic diversity, and exploring how biological and physical factors shape this population trait, are fundamental for understanding this phenomenon. Coastal marine ecosystems are one of the most susceptible habitats to invasion given the complex network of maritime transport. In this work we study the cryptogenic anemone, Anemonia alicemartinae, which has rapidly increased its geographical range southward during the last 50 years (approx. 2000 km) along the southeastern Pacific coast. Based on COI mtDNA sequences we evaluated three main hypotheses: a) the genetic diversity of A. alicemartinae decreases according to the direction of invasion (from north to south); b) there is biogeographic-phylogeographic concordance at the 30°S biogeographic break; and c) the demographic history is coherent with a recent geographic expansion. A total of 161 individual samples of A. alicemartinae were collected along the southeastern Pacific coast range of distribution, covering more than 2000 km, including samples along the 30°S biogeographical break. Results showed low genetic diversity (Hd = 0.253; π = 0.08) and a lack of geographic population genetic structure (FST = - 0.009, p-value = 0.656). The highest genetic diversity was observed in Peru (Chero and Mesas) and at localities close to the main Chilean seaports. We did not observe concordance between biogeographic and phylogeographic patterns or isolation by distance. Demographic indices (D = - 2.604, p < 0.001; Fu's = - 26.619, p < 0.001), as well as a star-like configuration of the haplotype network support recent population expansion of this species. Our results, together with historical field observations, support the idea that

  11. 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

  12. 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

  13. Genetic Diversity of Cell-Invasive Erythromycin-Resistant and -Susceptible Group A Streptococci Determined by Analysis of the RD2 Region of the prtF1 Gene

    PubMed Central

    Spinaci, Cinzia; Magi, Gloria; Zampaloni, Claudia; Vitali, Luca A.; Paoletti, Claudia; Catania, Maria R.; Prenna, Manuela; Ferrante, Luigi; Ripa, Sandro; Varaldo, Pietro E.; Facinelli, Bruna

    2004-01-01

    The RD2 region of the internalization-associated gene prtF1, which encodes the fibronectin-binding repeat domain type 2 of protein F1, plays a crucial role in the entry of group A streptococci (GAS) into epithelial cells. A molecular study of the variability of the RD2 region was carried out with 77 independent Italian GAS, 66 erythromycin resistant (ER) and 11 erythromycin susceptible (ES), which had previously been investigated for the association between erythromycin resistance and ability to enter human respiratory cells. The amplicons obtained from PCR analysis of the RD2 region were consistent with a number of RD2 repeats ranging from one to five, more frequently four (n = 30), three (n = 27), and one (n = 18). A new method to type cell-invasive GAS (RD2 typing) was developed by combining PCR analysis of the RD2 region and restriction analysis of PCR products with endonucleases HaeIII, DdeI, and HinfI. Overall, 10 RD2 types (a to j) were distinguished (all detected among the 66 ER isolates, four detected among the 11 ES isolates). Comparison and correlation of RD2 typing data with the genotype and phenotype of macrolide resistance and with data from PCR M typing and SmaI macrorestriction analysis allowed us to identify 41 different clones (31 among the 66 ER isolates and 10 among the 11 ES isolates). Three major clones accounted for 40% of the isolates (47% of ER strains). Some ES isolates appeared to be related to ER isolates with identical combinations of RD2 type and emm type. While simultaneous use of different typing methods is essential for a thorough investigation of GAS epidemiology, RD2 typing may be especially helpful in typing cell-invasive GAS. PMID:14766830

  14. Genetic diversity in two introduced biofouling amphipods (Amphipods valida and Jassa marmorata) along the Pacific North American coast: investigation into molecular identification and cryptic diversity

    EPA Science Inventory

    We investigated patterns of genetic diversity among invasive populations of A. valida and J. marmorata from the Pacific North American coast to assess the accuracy of morphological identification and determine whether or not cryptic diversity and multiple introductions contribute...

  15. Effects of Invasive-Plant Management on Nitrogen-Removal Services in Freshwater Tidal Marshes.

    PubMed

    Alldred, Mary; Baines, Stephen B; Findlay, Stuart

    2016-01-01

    Establishing relationships between biodiversity and ecosystem function is an ongoing endeavor in contemporary ecosystem and community ecology, with important practical implications for conservation and the maintenance of ecosystem services. Removal of invasive plant species to conserve native diversity is a common management objective in many ecosystems, including wetlands. However, substantial changes in plant community composition have the potential to alter sediment characteristics and ecosystem services, including permanent removal of nitrogen from these systems via microbial denitrification. A balanced assessment of costs associated with keeping and removing invasive plants is needed to manage simultaneously for biodiversity and pollution targets. We monitored small-scale removals of Phragmites australis over four years to determine their effects on potential denitrification rates relative to three untreated Phragmites sites and adjacent sites dominated by native Typha angustifolia. Sediment ammonium increased following the removal of vegetation from treated sites, likely as a result of decreases in both plant uptake and nitrification. Denitrification potentials were lower in removal sites relative to untreated Phragmites sites, a pattern that persisted at least two years following removal as native plant species began to re-colonize treated sites. These results suggest the potential for a trade-off between invasive-plant management and nitrogen-removal services. A balanced assessment of costs associated with keeping versus removing invasive plants is needed to adequately manage simultaneously for biodiversity and pollution targets. PMID:26914688

  16. Diet breadth influences how the impact of invasive plants is propagated through food webs.

    PubMed

    Carvalheiro, Luisa G; Buckley, Yvonne M; Memmott, Jane

    2010-04-01

    Invasive plants are considered a major cause of ecosystem degradation worldwide. While their impacts on native plants have been widely reported, there is little information on how these impacts propagate through food webs and affect species at higher trophic levels. Using a quantitative food web approach we evaluated the impacts of an invasive plant on plant-herbivore-parasitoid communities, asking specifically how diet breadth influences the propagation of such impacts. Measuring the impact of the alien plant at the plant level seriously underestimated the community-level effect of this weed as it also caused changes in the abundance of native herbivores and parasitoids, along with a decrease in parasitoid species richness. The invading plant affected specialist and generalist subsets of communities differently, having significant and strong negative impacts on the abundance of all specialists with no negative effect on generalist consumers. Specialist consumer decline led to further disruptions of top-down regulatory mechanisms, releasing generalist species from competition via shared natural enemies. Plant invasion also significantly increased the evenness of species abundance of all trophic levels in the food webs, as well as the evenness of species interaction frequency. Extending impact evaluation to higher trophic levels and considering changes in trophic diversity within levels is hence essential for a full evaluation of the consequences of invasion by alien plants. Moreover, information on diet breadth of species in the invaded community should be taken into account when evaluating/predicting the impacts on any introduced species. PMID:20462120

  17. Effects of Invasive-Plant Management on Nitrogen-Removal Services in Freshwater Tidal Marshes

    PubMed Central

    Alldred, Mary; Baines, Stephen B.; Findlay, Stuart

    2016-01-01

    Establishing relationships between biodiversity and ecosystem function is an ongoing endeavor in contemporary ecosystem and community ecology, with important practical implications for conservation and the maintenance of ecosystem services. Removal of invasive plant species to conserve native diversity is a common management objective in many ecosystems, including wetlands. However, substantial changes in plant community composition have the potential to alter sediment characteristics and ecosystem services, including permanent removal of nitrogen from these systems via microbial denitrification. A balanced assessment of costs associated with keeping and removing invasive plants is needed to manage simultaneously for biodiversity and pollution targets. We monitored small-scale removals of Phragmites australis over four years to determine their effects on potential denitrification rates relative to three untreated Phragmites sites and adjacent sites dominated by native Typha angustifolia. Sediment ammonium increased following the removal of vegetation from treated sites, likely as a result of decreases in both plant uptake and nitrification. Denitrification potentials were lower in removal sites relative to untreated Phragmites sites, a pattern that persisted at least two years following removal as native plant species began to re-colonize treated sites. These results suggest the potential for a trade-off between invasive-plant management and nitrogen-removal services. A balanced assessment of costs associated with keeping versus removing invasive plants is needed to adequately manage simultaneously for biodiversity and pollution targets. PMID:26914688

  18. Freshwater ecosystems and aquatic insects: a paradox in biological invasions.

    PubMed

    Fenoglio, Stefano; Bonada, Núria; Guareschi, Simone; López-Rodríguez, Manuel J; Millán, Andrés; Tierno de Figueroa, J Manuel

    2016-04-01

    Biological invasions have increased significantly in response to global change and constitute one of the major causes of biodiversity loss. Insects make up a large fraction of invasive species, in general, and freshwaters are among the most invaded ecosystems on our planet. However, even though aquatic insects dominate most inland waters, have unparalleled taxonomic diversity and occupy nearly all trophic niches, there are almost no invasive insects in freshwaters. We present some hypotheses regarding why aquatic insects are not common among aquatic invasive organisms, suggesting that it may be the result of a suite of biological, ecological and anthropogenic factors. Such specific knowledge introduces a paradox in the current scientific discussion on invasive species; therefore, a more in-depth understanding could be an invaluable aid to disentangling how and why biological invasions occur. PMID:27072403

  19. Hybrid watermilfoil lineages are more invasive and less sensitive to a commonly used herbicide than their exotic parent (Eurasian watermilfoil)

    PubMed Central

    LaRue, Elizabeth A; Zuellig, Matthew P; Netherland, Michael D; Heilman, Mark A; Thum, Ryan A

    2013-01-01

    Hybridization may stimulate the evolution of invasiveness in human-impacted habitats if unique hybrid genotypes have higher fitness than parental genotypes. Human efforts to control invasive taxa frequently involve the intentional alteration of habitats, but few studies have considered whether hybridization can result in decreased sensitivity to control measures. Here, we investigate whether interspecific hybrids between introduced Eurasian watermilfoil (Myriophyllum spicatum) and native northern watermilfoil (M. sibiricum) are more invasive than parental Eurasian watermilfoil, especially in regard to their relative responses to an herbicide commonly applied for their control (2,4-dichlorophenoxyacetic acid; 2,4-D). In two separate laboratory experiments, hybrids on average grew faster and were less sensitive to 2,4-D compared with parental Eurasian watermilfoil. These two invasive traits appear to be common in hybrid watermilfoils, as opposed to being restricted to a few unique lineages, because they were found in a diversity of hybrid genotypes from several independent hybridization events. In addition, we found that hybrids occurred more frequently than parental species in natural lakes previously treated with 2,4-D. Our results provide compelling empirical evidence that hybridization is associated with the evolution of increased invasiveness in watermilfoils, and have important implications for their management. PMID:23745138

  20. 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

  1. Are we "missing the boat" on preventing the spread of invasive plants in rangelands?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Invasive plants are negatively impacting the ecological and economic production of rangelands by reducing resource productivity, decreasing biodiversity, displacing native vegetation, and altering ecosystem processes and functions. However, despite these well known negative impacts, once invasive p...

  2. PREVENTION: A PROACTIVE APPROACH TO THE CONTROL OF INVASIVE PLANTS IN WILDLANDS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Infestations of wildlands by invasive plants can reduce resource productivity, decrease biodiversity, displace native vegetation, and alter ecosystem processes and functions. The traditional reactive strategy of controlling established invasive plant infestations followed by restoration of the nati...

  3. Selection on herbivory resistance and growth rate in an invasive plant

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Invasive species face different conditions in their new range, which may lead to evolutionary change. The evolution of increased competitive ability (EICA) hypothesis proposes that invasive species evolve decreased defense and increased growth rate and competitive ability following introduction. W...

  4. Does clozapine decrease smoking?

    PubMed

    de Leon, Jose; Diaz, Francisco J; Josiassen, Richard C; Cooper, Thomas B; Simpson, George M

    2005-06-01

    McEvoy et al.'s study in 1999, which used cotinine levels but had limited power, suggested that clozapine treatment may be associated with a mild smoking decrease (particularly when plasma clozapine levels are > 150 ng/ml). Some naturalistic studies also suggest that clozapine treatment may be associated with a mild smoking decrease. The present study included 38 schizophrenic daily smokers from a double-blind clozapine trial. Five analyses were tested for significant decreases in plasma cotinine levels from a haloperidol baseline to: (1) the end of clozapine trials regarding clozapine doses (100, 300 or 600 mg/day), (2) the end of the clozapine trial where the highest plasma clozapine level was achieved, (3) the end of the clozapine trial where a clozapine level in the 150-450 ng/ml range was achieved, (4) the end of the first clozapine trial regardless of clozapine dose, and (5) the end of the last clozapine trial in the study. The first and straightforward analysis by dose showed no clozapine effects on smoking. The second and the third analyses (an attempt to mimic the design by McEvoy et al. [McEvoy, J.P., Freudenreich, O., Wilson, W.H., 1999. Smoking and therapeutic response to clozapine in patients with schizophrenia. Biol. Psychiat. 46, 125-129.]) also indicated that there was not a significant effect of clozapine on smoking. The fourth and five analyses were also negative. None of the five analyses in our clozapine trial demonstrated that clozapine had major effects on smoking. This study cannot rule out that in some subjects, clozapine treatment may be associated with a small decrease in smoking. New prospective longitudinal studies using repeated cotinine and clozapine levels are needed to explore whether clozapine may reduce smoking in some patients. PMID:15951089

  5. Abiotic constraints eclipse biotic resistance in determining invasibility along experimental vernal pool gradients.

    PubMed

    Gerhardt, Fritz; Collinge, Sharon K

    2007-04-01

    Effective management of invasive species requires that we understand the mechanisms determining community invasibility. Successful invaders must tolerate abiotic conditions and overcome resistance from native species in invaded habitats. Biotic resistance to invasions may reflect the diversity, abundance, or identity of species in a community. Few studies, however, have examined the relative importance of abiotic and biotic factors determining community invasibility. In a greenhouse experiment, we simulated the abiotic and biotic gradients typically found in vernal pools to better understand their impacts on invasibility. Specifically, we invaded plant communities differing in richness, identity, and abundance of native plants (the "plant neighborhood") and depth of inundation to measure their effects on growth, reproduction, and survival of five exotic plant species. Inundation reduced growth, reproduction, and survival of the five exotic species more than did plant neighborhood. Inundation reduced survival of three species and growth and reproduction of all five species. Neighboring plants reduced growth and reproduction of three species but generally did not affect survival. Brassica rapa, Centaurea solstitialis, and Vicia villosa all suffered high mortality due to inundation but were generally unaffected by neighboring plants. In contrast, Hordeum marinum and Lolium multiflorum, whose survival was unaffected by inundation, were more impacted by neighboring plants. However, the four measures describing plant neighborhood differed in their effects. Neighbor abundance impacted growth and reproduction more than did neighbor richness or identity, with growth and reproduction generally decreasing with increasing density and mass of neighbors. Collectively, these results suggest that abiotic constraints play the dominant role in determining invasibility along vernal pool and similar gradients. By reducing survival, abiotic constraints allow only species with the

  6. Embracing Diversity

    ERIC Educational Resources Information Center

    Roeck, Kathryn T.

    2009-01-01

    The high school art unit "Embracing Diversity" was the author's principal work towards the completion of a Masters thesis. The objective was to learn whether or not teaching an art unit that focused on sexual diversity could have a positive impact on the current culture one finds in high schools. The unit was found to have a positive impact on…

  7. Minimally invasive video-assisted versus minimally invasive nonendoscopic thyroidectomy.

    PubMed

    Fík, Zdeněk; Astl, Jaromír; Zábrodský, Michal; Lukeš, Petr; Merunka, Ilja; Betka, Jan; Chovanec, Martin

    2014-01-01

    Minimally invasive video-assisted thyroidectomy (MIVAT) and minimally invasive nonendoscopic thyroidectomy (MINET) represent well accepted and reproducible techniques developed with the main goal to improve cosmetic outcome, accelerate healing, and increase patient's comfort following thyroid surgery. Between 2007 and 2011, a prospective nonrandomized study of patients undergoing minimally invasive thyroid surgery was performed to compare advantages and disadvantages of the two different techniques. There were no significant differences in the length of incision to perform surgical procedures. Mean duration of hemithyroidectomy was comparable in both groups, but it was more time consuming to perform total thyroidectomy by MIVAT. There were more patients undergoing MIVAT procedures without active drainage in the postoperative course and we also could see a trend for less pain in the same group. This was paralleled by statistically significant decreased administration of both opiates and nonopiate analgesics. We encountered two cases of recurrent laryngeal nerve palsies in the MIVAT group only. MIVAT and MINET represent safe and feasible alternative to conventional thyroid surgery in selected cases and this prospective study has shown minimal differences between these two techniques. PMID:24800227

  8. 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

  9. 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...

  10. 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...

  11. Insect-Flower Interaction Network Structure Is Resilient to a Temporary Pulse of Floral Resources from Invasive Rhododendron ponticum

    PubMed Central

    Tiedeken, Erin Jo; Stout, Jane C.

    2015-01-01

    Invasive alien plants can compete with native plants for resources, and may ultimately decrease native plant diversity and/or abundance in invaded sites. This could have consequences for native mutualistic interactions, such as pollination. Although invasive plants often become highly connected in plant-pollinator interaction networks, in temperate climates they usually only flower for part of the season. Unless sufficient alternative plants flower outside this period, whole-season floral resources may be reduced by invasion. We hypothesized that the cessation of flowering of a dominant invasive plant would lead to dramatic, seasonal compositional changes in plant-pollinator communities, and subsequent changes in network structure. We investigated variation in floral resources, flower-visiting insect communities, and interaction networks during and after the flowering of invasive Rhododendron ponticum in four invaded Irish woodland sites. Floral resources decreased significantly after R. ponticum flowering, but the magnitude of the decrease varied among sites. Neither insect abundance nor richness varied between the two periods (during and after R. ponticum flowering), yet insect community composition was distinct, mostly due to a significant reduction in Bombus abundance after flowering. During flowering R. ponticum was frequently visited by Bombus; after flowering, these highly mobile pollinators presumably left to find alternative floral resources. Despite compositional changes, however, network structural properties remained stable after R. ponticum flowering ceased: generality increased, but quantitative connectance, interaction evenness, vulnerability, H’2 and network size did not change. This is likely because after R. ponticum flowering, two to three alternative plant species became prominent in networks and insects increased their diet breadth, as indicated by the increase in network-level generality. We conclude that network structure is robust to

  12. Implications of invasion by Juniperus virginiana on small mammals in the southern Great Plains

    USGS Publications Warehouse

    Horncastle, V.J.; Hellgren, E.C.; Mayer, P.M.; Ganguli, A.C.; Engle, David M.; Leslie, David M., Jr.

    2005-01-01

    Changes in landscape cover in the Great Plains are resulting from the range expansion and invasion of eastern red cedar (Juniperus virginiana). By altering the landscape and local vegetation, red cedar is changing the structure and function of habitat for small mammals. We examined effects of invasion by eastern red cedar on small mammals in 3 plant communities (tallgrass prairie, old field, and cross-timbers forest) in the cross-timbers ecoregion in Oklahoma. We sampled small mammals seasonally from May 2001 to August 2002 by using Sherman live traps and mark-recapture techniques on 3.24-ha, 450-trap grids in each plant community. We sampled vegetation in two hundred twenty-five 12 x 12-m cells within each grid. The structure of the small-mammal community differed among the 3 habitat types, with higher species diversity and richness in the tallgrass-prairie and old-field sites. Overall, the small-mammal community shifted along a gradient of increasing eastern red cedar. In the old-field and tallgrass-prairie plots, occurrence of grassland mammals decreased with increasing red cedar, whereas only 1 woodland mammal species increased. In the cross-timbers forest site, percent woody cover (<1 m in height), rather than cover of red cedar, was the most important factor affecting woodland mammal species. Examination of our data suggests that an increase in overstory cover from 0% to 30% red cedar can change a species-rich prairie community to a depauperate community dominated by 1 species, Peromyscus leucopus. Losses in species diversity and changes in mammal distribution paralleled those seen in avian communities invaded by eastern red cedar. Our results highlight ecological effects of invasion by eastern red cedar on diversity and function at multiple trophic levels. ?? 2005 American Society of Mammalogists.

  13. Does time since introduction influence enemy release of an invasive weed?

    PubMed

    Harvey, Kerinne J; Nipperess, David A; Britton, David R; Hughes, Lesley

    2013-10-01

    Release from natural enemies is considered to potentially play an important role in the initial establishment and success of introduced plants. With time, the species richness of herbivores using non-native plants may increase [species-time relationship (STR)]. We investigated whether enemy release may be limited to the early stages of invasion. Substituting space for time, we sampled invertebrates and measured leaf damage on the invasive species Senecio madagascariensis Poir. at multiple sites, north and south of the introduction site. Invertebrate communities were collected from plants in the field, and reared from collected plant tissue. We also sampled invertebrates and damage on the native congener Senecio pinnatifolius var. pinnatifolius A. Rich. This species served as a control to account for environmental factors that may vary along the latitudinal gradient and as a comparison for evaluating the enemy release hypothesis (ERH). In contrast to predictions of the ERH, greater damage and herbivore abundances and richness were found on the introduced species S. madagascariensis than on the native S. pinnatifolius. Supporting the STR, total invertebrates (including herbivores) decreased in abundance, richness and Shannon diversity from the point of introduction to the invasion fronts of S. madagascariensis. Leaf damage showed the opposite trend, with highest damage levels at the invasion fronts. Reared herbivore loads (as opposed to external collections) were greater on the invader at the point of introduction than on sites further from this region. These results suggest there is a complex relationship between the invader and invertebrate community response over time. S. madagascariensis may be undergoing rapid changes at its invasion fronts in response to environmental and herbivore pressure. PMID:23512201

  14. Range expansion of invasive shrubs: implication for crown fire risk in forestlands of the southern USA

    PubMed Central

    Wang, Hsiao-Hsuan; Wonkka, Carissa L.; Grant, William E.; Rogers, William E.

    2016-01-01

    Non-native plant invasions and changing management activities have dramatically altered the structure and composition of forests worldwide. Invasive shrubs and fire suppression have led to increased densification and biomass accumulation in forest ecosystems of the southeastern USA. Notably, Chinese and European privets are rapid growing, shade-tolerant shrubs which number among the most aggressive invasive species in these forests. Privet encroachment has caused losses of native diversity, alteration of ecosystem processes and changes in community structure. The latter has become manifest through decreases in fine herbaceous fuels concurrent with increases in coarse woody fuels in forest understoreys. These alterations in fuel structure will potentially lead to less frequent, but more severe forest fires, which threaten important forest resources during extreme weather conditions. Drawing on extensive data sets compiled by the US Forest Service, we integrated statistical forecasting and analytical techniques within a spatially explicit, agent-based, simulation framework to predict potential range expansion of Chinese and European privet (Ligustrum sinense and L. vulgare) and the associated increase in crown fire risk over the next two decades in forestlands of Mississippi and Alabama. Our results indicate that probability of invasion is positively associated with elevation, adjacency (within 300 m) to water bodies, mean daily maximum temperature, site productivity and private land ownership, and is negatively associated with slope, stand age, artificial regeneration, distance to the nearest road and fire disturbance. Our projections suggest the total area invaded will increase from 1.36 to ≈31.39% of all forestlands in Mississippi and Alabama (≈7 million hectares) and the annual frequency of crown fires in these forestlands will approximately double within the next two decades. Such time series projections of annual range expansions and crown fire frequency

  15. Connecting differential responses of native and invasive riparian plants to climate change and environmental alteration.

    PubMed

    Flanagan, Neal E; Richardson, Curtis J; Ho, Mengchi

    2015-04-01

    Climate change is predicted to impact river systems in the southeastern United States through alterations of temperature, patterns of precipitation and hydrology. Future climate scenarios for the southeastern United States predict (1) surface water temperatures will warm in concert with air temperature, (2) storm flows will increase and base flows will decrease, and (3) the annual pattern of synchronization between hydroperiod and water temperature will be altered. These alterations are expected to disturb floodplain plant communities, making them more vulnerable to establishment of invasive species. The primary objective of this study is to evaluate whether native and invasive riparian plant assemblages respond differently to alterations of climate and land use. To study the response of riparian wetlands to watershed and climate alterations, we utilized an existing natural experiment imbedded in gradients of temperature and hydrology-found among dammed and undammed rivers. We evaluated a suite of environmental variables related to water temperature, hydrology, watershed disturbance, and edaphic conditions to identify the strongest predictors of native and invasive species abundances. We found that native species abundance is strongly influenced by climate-driven variables such as temperature and hydrology, while invasive species abundance is more strongly influenced by site-specific factors such as land use and soil nutrient availability. The patterns of synchronization between plant phenology, annual hydrographs, and annual water temperature cycles may be key factors sustaining the viability of native riparian plant communities. Our results demonstrate the need to understand the interactions between climate, land use, and nutrient management in maintaining the species diversity of riparian plant communities. Future climate change is likely to result in diminished competitiveness of native plant species, while the competitiveness of invasive species will increase

  16. Arbuscular mycorrhizal assemblages in native plant roots change in the presence of invasive exotic grasses

    USGS Publications Warehouse

    Hawkes, C.V.; Belnap, J.; D'Antonio, C.; Firestone, M.K.

    2006-01-01

    Plant invasions have the potential to significantly alter soil microbial communities, given their often considerable aboveground effects. We examined how plant invasions altered the arbuscular mycorrhizal fungi of native plant roots in a grassland site in California and one in Utah. In the California site, we used experimentally created plant communities composed of exotic (Avena barbata, Bromus hordeaceus) and native (Nassella pulchra, Lupinus bicolor) monocultures and mixtures. In the Utah semi-arid grassland, we took advantage of invasion by Bromus tectorum into long-term plots dominated by either of two native grasses, Hilaria jamesii or Stipa hymenoides. Arbuscular mycorrhizal fungi colonizing roots were characterized with PCR amplification of the ITS region, cloning, and sequencing. We saw a significant effect of the presence of exotic grasses on the diversity of mycorrhizal fungi colonizing native plant roots. In the three native grasses, richness of mycorrhizal fungi decreased; in the native forb at the California site, the number of fungal RFLP patterns increased in the presence of exotics. The exotic grasses also caused the composition of the mycorrhizal community in native roots to shift dramatically both in California, with turnover of Glomus spp., and Utah, with replacement of Glomus spp. by apparently non-mycorrhizal fungi. Invading plants may be able to influence the network of mycorrhizal fungi in soil that is available to natives through either earlier root activity or differential carbon provision compared to natives. Alteration of the soil microbial community by plant invasion can provide a mechanism for both successful invasion and the resulting effects of invaders on the ecosystem. ?? Springer 2006.

  17. Range expansion of invasive shrubs: implication for crown fire risk in forestlands of the southern USA.

    PubMed

    Wang, Hsiao-Hsuan; Wonkka, Carissa L; Grant, William E; Rogers, William E

    2016-01-01

    Non-native plant invasions and changing management activities have dramatically altered the structure and composition of forests worldwide. Invasive shrubs and fire suppression have led to increased densification and biomass accumulation in forest ecosystems of the southeastern USA. Notably, Chinese and European privets are rapid growing, shade-tolerant shrubs which number among the most aggressive invasive species in these forests. Privet encroachment has caused losses of native diversity, alteration of ecosystem processes and changes in community structure. The latter has become manifest through decreases in fine herbaceous fuels concurrent with increases in coarse woody fuels in forest understoreys. These alterations in fuel structure will potentially lead to less frequent, but more severe forest fires, which threaten important forest resources during extreme weather conditions. Drawing on extensive data sets compiled by the US Forest Service, we integrated statistical forecasting and analytical techniques within a spatially explicit, agent-based, simulation framework to predict potential range expansion of Chinese and European privet (Ligustrum sinenseandL. vulgare) and the associated increase in crown fire risk over the next two decades in forestlands of Mississippi and Alabama. Our results indicate that probability of invasion is positively associated with elevation, adjacency (within 300 m) to water bodies, mean daily maximum temperature, site productivity and private land ownership, and is negatively associated with slope, stand age, artificial regeneration, distance to the nearest road and fire disturbance. Our projections suggest the total area invaded will increase from 1.36 to ≈31.39% of all forestlands in Mississippi and Alabama (≈7 million hectares) and the annual frequency of crown fires in these forestlands will approximately double within the next two decades. Such time series projections of annual range expansions and crown fire frequency

  18. 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

  19. 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

  20. [Minimally Invasive Open Surgery for Lung Cancer].

    PubMed

    Nakagawa, Kazuo; Watanabe, Shunichi

    2016-07-01

    Significant efforts have been made to reduce the invasiveness of surgical procedures by surgeons for a long time. Surgeons always keep it in mind that the basic principle performing less invasive surgical procedures for malignant tumors is to decrease the invasiveness for patients without compromising oncological curability and surgical safety. Video-assisted thoracic surgery (VATS) has been used increasingly as a minimally invasive approach to lung cancer surgery. Whereas, whether VATS lobectomy is a less invasive procedure and has equivalent or better clinical effect compared with open lobectomy for patients with lung cancer remains controversial because of the absence of randomized prospective studies. The degree of difficulty for anatomical lung resection depends on the degree of the fissure development, mobility of hilar lymph nodes, and the degree of pleural adhesions. During pulmonary surgery, thoracic surgeons always have to deal with not only these difficulties but other unexpected events such as intraoperative bleeding. Recently, we perform pulmonary resection for lung cancer with minimally invasive open surgery (MIOS) approach. In this article, we introduce the surgical procedure of MIOS and demonstrate short-term results. Off course, the efficacy of MIOS needs to be further evaluated with long-term results. PMID:27440030

  1. A global assessment of invasive plant impacts on resident species, communities and ecosystems: the interaction of impact measures, invading species' traits and environment

    PubMed Central

    Pyšek, Petr; Jarošík, Vojtěch; Hulme, Philip E; Pergl, Jan; Hejda, Martin; Schaffner, Urs; Vilà, Montserrat

    2012-01-01

    With the growing body of literature assessing the impact of invasive alien plants on resident species and ecosystems, a comprehensive assessment of the relationship between invasive species traits and environmental settings of invasion on the characteristics of impacts is needed. Based on 287 publications with 1551 individual cases that addressed the impact of 167 invasive plant species belonging to 49 families, we present the first global overview of frequencies of significant and non-significant ecological impacts and their directions on 15 outcomes related to the responses of resident populations, species, communities and ecosystems. Species and community outcomes tend to decline following invasions, especially those for plants, but the abundance and richness of the soil biota, as well as concentrations of soil nutrients and water, more often increase than decrease following invasion. Data mining tools revealed that invasive plants exert consistent significant impacts on some outcomes (survival of resident biota, activity of resident animals, resident community productivity, mineral and nutrient content in plant tissues, and fire frequency and intensity), whereas for outcomes at the community level, such as species richness, diversity and soil resources, the significance of impacts is determined by interactions between species traits and the biome invaded. The latter outcomes are most likely to be impacted by annual grasses, and by wind pollinated trees invading mediterranean or tropical biomes. One of the clearest signals in this analysis is that invasive plants are far more likely to cause significant impacts on resident plant and animal richness on islands rather than mainland. This study shows that there is no universal measure of impact and the pattern observed depends on the ecological measure examined. Although impact is strongly context dependent, some species traits, especially life form, stature and pollination syndrome, may provide a means to predict

  2. Invasion of the Fungal Pathogen Batrachochytrium dendrobatidis on California Islands.

    PubMed

    Yap, Tiffany A; Gillespie, Lauren; Ellison, Silas; Flechas, Sandra V; Koo, Michelle S; Martinez, Ari E; Vredenburg, Vance T

    2016-03-01

    Batrachochytrium dendrobatidis (Bd), an amphibian fungal pathogen, has infected >500 species and caused extinctions or declines in >200 species worldwide. Despite over a decade of research, little is known about its invasion biology. To better understand this, we conducted a museum specimen survey (1910-1997) of Bd in amphibians on 11 California islands and found a pattern consistent with the emergence of Bd epizootics on the mainland, suggesting that geographic isolation did not prevent Bd invasion. We propose that suitable habitat, host diversity, and human visitation overcome isolation from the mainland and play a role in Bd invasion. PMID:26493624

  3. Minimally Invasive Valve Surgery

    PubMed Central

    Pope, Nicolas H.; Ailawadi, Gorav

    2014-01-01

    Cardiac valve surgery is life saving for many patients. The advent of minimally invasive surgical techniques has historically allowed for improvement in both post-operative convalescence and important clinical outcomes. The development of minimally invasive cardiac valve repair and replacement surgery over the past decade is poised to revolutionize the care of cardiac valve patients. Here, we present a review of the history and current trends in minimally invasive aortic and mitral valve repair and replacement, including the development of sutureless bioprosthetic valves. PMID:24797148

  4. Mixed population genomics support for the central marginal hypothesis across the invasive range of the cane toad (Rhinella marina) in Australia.

    PubMed

    Trumbo, Daryl R; Epstein, Brendan; Hohenlohe, Paul A; Alford, Ross A; Schwarzkopf, Lin; Storfer, Andrew

    2016-09-01

    Understanding factors that cause species' geographic range limits is a major focus in ecology and evolution. The central marginal hypothesis (CMH) predicts that species cannot adapt to conditions beyond current geographic range edges because genetic diversity decreases from core to edge due to smaller, more isolated edge populations. We employed a population genomics framework using 24 235-33 112 SNP loci to test major predictions of the CMH in the ongoing invasion of the cane toad (Rhinella marina) in Australia. Cane toad tissue samples were collected along broad-scale, core-to-edge transects across their invasive range. Geographic and ecological core areas were identified using GIS and habitat suitability indices from ecological niche modelling. Bayesian clustering analyses revealed three genetic clusters, in the northwest invasion-front region, northeast precipitation-limited region and southeast cold temperature-limited region. Core-to-edge patterns of genetic diversity and differentiation were consistent with the CMH in the southeast, but were not supported in the northeast and showed mixed support in the northwest. Results suggest cold temperatures are a likely contributor to southeastern range limits, consistent with CMH predictions. In the northeast and northwest, ecological processes consisting of a steep physiological barrier and ongoing invasion dynamics, respectively, are more likely explanations for population genomic patterns than the CMH. PMID:27393238

  5. Invasive plant management on anticipated conservation benefits: a scientific Assessment

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Invasive plants negatively impact rangelands throughout the western United States by displacing desirable species, altering ecological processes, reducing wildlife habitat, degrading systems, altering fire regimes, and decreasing productivity. Assessing the influence of conservation practices on var...

  6. 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 ...

  7. 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

  8. Drug diversion

    PubMed Central

    Wood, Danielle

    2015-01-01

    SUMMARY Prescription drug diversion has significant health, legal and social implications. Deaths from misuse of prescription drugs account for a significant proportion of overdose deaths. The drugs most commonly involved are analgesics, particularly opioids, and psychoactive drugs, particularly benzodiazepines. Diverted drugs are most often sourced from a family member or friend, but are also sourced from overseas pharmacies or laboratories, or bought from drug dealers. Drug diversion can be mitigated by good prescribing practices. Systems for monitoring the prescribing and dispensing of medicines are being instituted across Australia. PMID:26648654

  9. Discovering Diversity.

    ERIC Educational Resources Information Center

    Manner, Barbara M.; Hattler, Jean Anne

    2000-01-01

    Introduces a preservice teacher field trip to the rain forests and coastal areas. This experience develops an awareness for different cultures among preservice teachers by experiencing biological and cultural diversity in Costa Rica. Presents students' own ideas on this experience. (YDS)

  10. PLANT DIVERSITY

    EPA Science Inventory

    Habitat change statistics and species-area curves were used to estimate the effects of alternative future scenarios for agriculture on plant diversity in Iowa farmlands. Study areas were two watersheds in central Iowa of about 50 and 90 square kilometers, respectively. Future s...

  11. Generational diversity.

    PubMed

    Kramer, Linda W

    2010-01-01

    Generational diversity has proven challenges for nurse leaders, and generational values may influence ideas about work and career planning. This article discusses generational gaps, influencing factors and support, and the various generational groups present in today's workplace as well as the consequences of need addressing these issues. The article ends with a discussion of possible solutions. PMID:20395729

  12. Diversity Trailblazer

    ERIC Educational Resources Information Center

    Stuart, Reginald

    2012-01-01

    When Dr. Kumea Shorter-Gooden took on her newly created job this month at the University of Maryland's flagship College Park campus, she assumed a challenge at the school with a lot riding on her shoulders--helping the University of Maryland strengthen its diversity efforts and, thus, its relevance to the state in the future and standing among the…

  13. Aberrant Wnt-1/beta-catenin signaling and WIF-1 deficiency are important events which promote tumor cell invasion and metastasis in salivary gland adenoid cystic carcinoma.

    PubMed

    Wang, Ruinan; Geng, Ning; Zhou, Yuqiao; Zhang, Dunfang; Li, Longjiang; Li, Jing; Ji, Ning; Zhou, Min; Chen, Yu; Chen, Qianming

    2015-01-01

    This study investigates whether Wnt components play a role in carcinogenesis, or the invasion and metastasis of salivary glands, also referred to as adenoid cystic carcinoma (sAdCC). Several sAdCC cell lines with low invasive potential (ACC-2), high metastatic potential (ACC-M), and higher invasive potential (T-ACC-M) were examined to determine whether Wnt components correlate with tumors' invasive and metastatic behavior. Immunohistochemistry was performed in a sAdCC tissue array. ACC-M expressed higher levels of Wnt-1, beta-catenin and lower WIF-1 compared to ACC-2 (P<0.05). T-ACC-M exhibited increased mRNA of Wnt-1 and beta-catenin, and decreased WIF-1 compared to ACC-2 and ACC-M. Immuno-histochemistry showed up-regulation of Wnt-1 and down-regulation of WIF-1 in sAdCC compared with normal salivary glands. Beta-catenin was found in the cytoplasm and nuclei of sAdCC. Dislocation of E-cadherin in sAdCC was observed. These results suggest that sAdCC exhibits diverse expressions of Wnt components. It has an important relationship with the invasive phenotype of these cells. PMID:26405993

  14. Are modern biological invasions an unprecedented form of global change?

    PubMed

    Ricciardi, Anthony

    2007-04-01

    The uniqueness of the current, global mass invasion by nonindigenous species has been challenged recently by researchers who argue that modern rates and consequences of nonindigenous species establishment are comparable to episodes in the geological past. Although there is a fossil record of species invasions occurring in waves after geographic barriers had been lifted, such episodic events differ markedly from human-assisted invasions in spatial and temporal scales and in the number and diversity of organisms involved in long-distance dispersal. Today, every region of the planet is simultaneously affected and modern rates of invasion are several orders of magnitude higher than prehistoric rates. In terms of its rate and geographical extent, its potential for synergistic disruption and the scope of its evolutionary consequences, the current mass invasion event is without precedent and should be regarded as a unique form of global change. Prehistoric examples of biotic interchanges are nonetheless instructive and can increase our understanding of species-area effects, evolutionary effects, biotic resistance to invasion, and the impacts of novel functional groups introduced to naïve biotas. Nevertheless, they provide only limited insight into the synergistic effects of invasions and other environmental stressors, the effect of frequent introductions of large numbers of propagules, and global homogenization, all of which characterize the current mass invasion event. PMID:17391183

  15. Cultural diversity, economic development and societal instability

    USGS Publications Warehouse

    Nettle, D.; Grace, J.B.; Choisy, M.; Cornell, H.V.; Guegan, J.-F.; Hochberg, M.E.

    2007-01-01

    Background. Social scientists have suggested that cultural diversity in a nation leads to societal instability. However, societal instability may be affected not only by within-nation on ?? diversity, but also diversity between a nation and its neighbours or ?? diversity. It is also necessary to distinguish different domains of diversity, namely linguistic, ethnic and religious, and to distinguish between the direct effects of diversity on societal instability, and effects that are mediated by economic conditions. Methodology/Principal Findings. We assembled a large cross-national dataset with information on ?? and ?? cultural diversity, economic conditions, and indices of societal instability. Structural equation modeling was used to evaluate the direct and indirect effects of cultural diversity on economics and societal stability. Results show that different type and domains of diversity have interacting effects. As previously documented, linguistic ?? diversity has a negative effect on economic performance, and we show that it is largely through this economic mechanism that it affects societal instability. For ?? diversity, the higher the linguistic diversity among nations in a region, the less stable the nation. But, religious ?? diversity has the opposite effect, reducing instability, particularly in the presence of high linguistic diversity. Conclusions. Within-nation linguistic diversity is associated with reduced economic performance, which, in turn, increases societal instability. Nations which differ linguistically from their neighbors are also less stable. However, religious diversity between, neighboring nations has the opposite effect, decreasing societal instability.

  16. 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

  17. 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

  18. Climate change, plant traits, and invasion in natural and agricultural ecosystems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Invasive species and climate change, each of which is likely to influence agricultural productivity and biological diversity, are also likely to interact. This chapter explores characteristics of both invasive plants and invaded ecosystems to search for generalizations that may allow us to predict w...

  19. Exotic weevil invasion increases floral herbivore community density, function, and impact on a native plant

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Consumer communities are being re-arranged through unprecedented rates of human-mediated invasions and extinctions. Such changes in consumer composition and diversity potentially alter pressure and impact on resource populations. Although insect herbivore invasions are common, and exotic herbivores...

  20. 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

  1. 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

  2. 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

  3. Managing diversity.

    PubMed

    Wagner, M

    1991-09-30

    One look at projections for the U.S. work force through the year 2000 shows why healthcare administrators will be facing some new challenges. With the majority of new workers belonging to minority groups, "managing diversity" has become the newest catch phrase as executives work to reduce tensions resulting from race, gender or culture-based differences among workers, while also learning to understand and value those differences. PMID:10114151

  4. The importance of education in managing invasive plant species

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Invasive plant species can establish in diverse environments and with the increase in human mobility, they are no longer restricted to isolated pockets in remote parts of the world. Cheat grass (Bromus tectorum L.) in rangelands, purple loosestrife (Lythrum salicaria L.) in wet lands and Canada this...

  5. Distinct invasion strategies operating within a natural annual plant system.

    PubMed

    Lai, Hao Ran; Mayfield, Margaret M; Gay-des-Combes, Justine M; Spiegelberger, Thomas; Dwyer, John M

    2015-04-01

    Alien plant species are known to have a wide range of impacts on recipient communities, from resident species' exclusions to coexistence with resident species. It remains unclear; however, if this variety of impacts is due to different invader strategies, features of recipient communities or both. To test this, we examined multiple plant invasions of a single ecosystem in southwestern Australia. We used extensive community data to calculate pairwise segregation between target alien species and many co-occurring species. We related segregation to species' positions along community trait hierarchies and identified at least two distinct invasion strategies: 'exploiters' which occupy high positions along key trait hierarchies and reduce local native species diversity (particularly in nutrient-enriched situations), and 'coexisters' who occupy intermediate trait positions and have no discernable impact on native diversity. We conclude that trait hierarchies, linked to measures of competition, can provide valuable insights about the processes driving different invasion outcomes. PMID:25728390

  6. Minimally invasive procedures on the lumbar spine.

    PubMed

    Skovrlj, Branko; Gilligan, Jeffrey; Cutler, Holt S; Qureshi, Sheeraz A

    2015-01-16

    Degenerative disease of the lumbar spine is a common and increasingly prevalent condition that is often implicated as the primary reason for chronic low back pain and the leading cause of disability in the western world. Surgical management of lumbar degenerative disease has historically been approached by way of open surgical procedures aimed at decompressing and/or stabilizing the lumbar spine. Advances in technology and surgical instrumentation have led to minimally invasive surgical techniques being developed and increasingly used in the treatment of lumbar degenerative disease. Compared to the traditional open spine surgery, minimally invasive techniques require smaller incisions and decrease approach-related morbidity by avoiding muscle crush injury by self-retaining retractors, preventing the disruption of tendon attachment sites of important muscles at the spinous processes, using known anatomic neurovascular and muscle planes, and minimizing collateral soft-tissue injury by limiting the width of the surgical corridor. The theoretical benefits of minimally invasive surgery over traditional open surgery include reduced blood loss, decreased postoperative pain and narcotics use, shorter hospital length of stay, faster recover and quicker return to work and normal activity. This paper describes the different minimally invasive techniques that are currently available for the treatment of degenerative disease of the lumbar spine. PMID:25610845

  7. [Advanced coronary artery surgery for minimally invasiveness].

    PubMed

    Yamaguchi, Shohjiro; Tomita, Shigeyuki; Watanabe, Go

    2008-07-01

    Since the development of drug-eluting stents, the conditions of coronary artery surgery have changed. The selection criteria for candidates for coronary artery bypass grafting (CABG) have become more stringent. In this era, surgeons should perform less invasive surgery to save such candidates. Off-pump coronary artery bypass (OPCAB) will become the gold standard surgical procedure for the treatment of ischemic heart disease. This paper describes how to perform less invasive OPCAB with some useful devices and points out the pitfalls of the standard procedure. We have also introduced robotic surgery using the DaVinci system. This procedure decreases the length of dermal incisions. Robotic surgery has other advantages compared with the standard endoscopic surgery. The arm of the robot absorbs the vibrations of human hands and the command function can decrease movement significantly. This arm has five joints, allowing the operator to manipulate the equipment easily inside the body. We have also performed awake CABG with high epidural anesthesia for minimally invasive surgery. This procedure is performed especially in patients with severe cerebrovascular disease and lung injury. In our institution, patients can be discharged only 5 days after this surgical procedure. Less invasive surgery will be the standard procedure in future. PMID:18681162

  8. 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

  9. 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.

  10. 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

  11. 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

  12. Constraints on coastal dune invasion for a notorious plant invader

    PubMed Central

    Griffith, Alden B.; Ahmed, Tania; Hildner, Abigail L. G.; Kuckreja, Shivani; Long, Shuangxou

    2015-01-01

    Although most biological invasions are not successful, relatively few studies have examined otherwise notorious invaders in systems where they are not highly problematic. The annual grass Bromus tectorum is a dominant invader in western North America, but is usually confined to human-dominated and disturbed systems (e.g. roadsides and parking lots) in the East where it remains virtually unstudied. This study aims to address fundamental ecological questions regarding B. tectorum in a Cape Cod dune ecosystem. (i) What is the range of variation in population dynamics and the potential for population growth? (ii) Which factors influence its local abundance and distribution? We observed substantial variation in population dynamics over 3 years, with the number of adult B. tectorum individuals increasing substantially between the first 2 years (λ = 9.24) and then decreasing (λ = 0.43). Population growth in terms of total seeds was similarly variable, but to a lesser extent (λ = 2.32 followed by λ = 0.32). Experimental soil disturbance led to a more than 10-fold increase in mean seedling emergence, and high sensitivity to differences in emergence carried this effect through the life cycle. In contrast, barriers to seed dispersal had no effect on population dynamics, suggesting limited dispersal in this system. Across the landscape, the presence of B. tectorum was associated with areas of higher plant diversity as opposed to those with a strong dominant (e.g. the foredune, dominated by Ammophila breviligulata, or low heathlands, characterized by Hudsonia tomentosa and Arctostaphylos uva-ursi). Overall, we find that B. tectorum is capable of both substantial population growth and decline in a dune ecosystem, but is likely limited without disturbance and dispersal agents. Thus, management actions that restrict dune access (e.g. for nesting habitat) likely have the co-benefit of limiting the invasive potential of B. tectorum. PMID:26558705

  13. Minimally invasive radioguided parathyroidectomy (MIRP).

    PubMed

    Goldstein, R E; Martin, W H; Richards, K

    2003-06-01

    The technique of parathyroidectomy has traditionally involved a bilateral exploration of the neck with the intent of visualizing 4 parathyroid glands and resecting pathologically enlarged glands. Parathyroid scanning using technetium-99m sestamibi has evolved and can now localize 80% to 90% of parathyroid adenomas. The technique of minimally invasive radioguided parathyroidectomy (MIRP) is a surgical option for most patients with primary hyperparathyroidism and a positive preoperative parathyroid scan. The technique makes use of a hand-held gamma probe that is used intraoperatively to guide the dissection in a highly directed manner with the procedure often performed under local anesthesia. The technique results in excellent cure rates while allowing most patients to leave the hospital within a few hours after the completion of the procedure. Current data also suggest the procedure can decrease hospital charges by approximately 50%. This technique may significantly change the management of primary hyperparathyroidism. PMID:12955045

  14. Effects of Mechanical Properties on Tumor Invasion: Insights from a Cellular Model

    PubMed Central

    Li, Yingzi; Naveed, Hammad; Liang, Jie; Xu, Lisa X.

    2016-01-01

    Understanding the regulating mechanism of tumor invasion is of crucial importance for both fundamental cancer research and clinical applications. Previous in vivo experiments have shown that invasive cancer cells dissociate from the primary tumor and invade into the stroma, forming an irregular invasive morphology. Although cell movements involved in tumor invasion are ultimately driven by mechanical forces of cell-cell interactions and tumor-host interactions, how these mechanical properties affect tumor invasion is still poorly understood. In this study, we use a recently developed two-dimensional cellular model to study the effects of mechanical properties on tumor invasion. We study the effects of cell-cell adhesions as well as the degree of degradation and stiffness of extracellular matrix (ECM). Our simulation results show that cell-cell adhesion relationship must be satisfied for tumor invasion. Increased adhesion to ECM and decreased adhesion among tumor cells result in invasive tumor behaviors. When this invasive behavior occurs, ECM plays an important role for both tumor morphology and the shape of invasive cancer cells. Increased stiffness and stronger degree of degradation of ECM promote tumor invasion, generating more aggressive tumor invasive morphologies. It can also generate irregular shape of invasive cancer cells, protruding towards ECM. The capability of our model suggests it a useful tool to study tumor invasion and might be used to propose optimal treatment in clinical applications. PMID:25571562

  15. [Diverse sustainability--sustainable diversity].

    PubMed

    Schmeling-Kludas, Christoph; Koch-Gromus, Uwe

    2011-08-01

    In spite of its plenitude, the scientific works of the important German psychologist Ernst August Dölle (1898-1972) are little adapted till today, mostly they are being reduced to his studies about dichotomy and duplicity. But based on his diaries of the year 1968, the authors can verify without doubt, that Dölle far ahead of his time, carried on research about sustainability and diversity. He was the first scientist worldwide to connect these two concepts. PMID:21837611

  16. What determines positive, neutral, and negative impacts of Solidago canadensis invasion on native plant species richness?

    PubMed Central

    Dong, Li-Jia; Yu, Hong-Wei; He, Wei-Ming

    2015-01-01

    Whether plant invasions pose a great threat to native plant diversity is still hotly debated due to conflicting findings. More importantly, we know little about the mechanisms of invasion impacts on native plant richness. We examined how Solidago canadensis invasion influenced native plants using data from 291 pairs of invaded and uninvaded plots covering an entire invaded range, and quantified the relative contributions of climate, recipient communities, and S. canadensis to invasion impacts. There were three types of invasion consequences for native plant species richness (i.e., positive, neutral, and negative impacts). Overall, the relative contributions of recipient communities, S. canadensis and climate to invasion impacts were 71.39%, 21.46% and 7.15%, respectively; furthermore, the roles of recipient communities, S. canadensis and climate were largely ascribed to plant diversity, density and cover, and precipitation. In terms of direct effects, invasion impacts were negatively linked to temperature and native plant communities, and positively to precipitation and soil microbes. Soil microbes were crucial in the network of indirect effects on invasion impacts. These findings suggest that the characteristics of recipient communities are the most important determinants of invasion impacts and that invasion impacts may be a continuum across an entire invaded range. PMID:26573017

  17. Importance of molehill disturbances for invasion by Bunias orientalis in meadows and pastures

    NASA Astrophysics Data System (ADS)

    Kiełtyk, Piotr; Mirek, Zbigniew

    2015-04-01

    Small-scale soil disturbances by fossorial animals can change physical and biotic conditions in disturbed patches and influence spatial and temporal dynamics, and the composition of plant communities. They create regeneration niches and colonization openings for native plants and, according to the intermediate disturbance hypothesis, they are expected to increase plant community diversity. However, it also has been reported that increased disturbance resource availability and decreased competition with native species may result in the invasion of communities by alien plant species, as predicted by the fluctuating resources theory of invasibility. In this study, we investigated the importance of European mole disturbances for the invasion of semi-natural fresh meadows and pastures by the alien plant, Bunias orientalis, which has mainly spread throughout Central Europe on anthropogenically disturbed sites. We hypothesized that the invader, being particularly well adapted to anthropogenic disturbances, enters into dense vegetation of meadows and pastures mainly on mole mounds. To assess the seedling recruitment of B. orientalis in relation to disturbance, we counted the number of seedlings that emerged on molehills and control plots in meadows and pastures. The establishment of juvenile (0-1 year) rosette plants on and off molehills was surveyed on 5 × 5 m plots. In accordance with our hypothesis, mole disturbances were found to serve as a gateway for B. orientalis by which the invader may colonize semi-natural grasslands. The seedlings of the species emerged almost solely on molehills and the young rosettes were established predominantly on mole mounds. Although the seedling density did not differ significantly between the meadows and pastures, the number of established plants in the pastures was considerably higher. We suggest that the invasion by B. orientalis in pastures may be facilitated by vegetative regeneration following root fragmentation by sheep pasturing.

  18. Extracellular Matrix Invasion in Metastases and Angiogenesis: Commentary on the Matrigel "Chemoinvasion Assay".

    PubMed

    Albini, Adriana

    2016-08-15

    Invasive and metastatic cells must cross the basement membrane's extracellular matrix to disseminate to distant sites. Although in the eighties the concept was well established, no easy in vitro functional assay was available. Working in Hynda Kleinman's and George Martin's laboratory at NIH (Bethesda, MD), where the reconstituted basement membrane Matrigel was discovered, I had the intuition that Matrigel coating of migration filters could represent a valid tool to mimic in vitro biological matrix barriers. The "chemoinvasion assay" using Matrigel in Boyden blind-well chambers was developed in 1985-1986 and published in Cancer Research in 1987. It was a rapid and easy tool for studying invasion, a crucial step in cancer metastasis. Since its conception, the assay has been employed for studies on the metastatic process, angiogenesis, and for the screening of drugs that are potentially able to decrease cell invasion. It was adapted to be easily employed as a routine assay and commercialized. In that historical article, we also described the use of thick layers of Matrigel for the study of morphogenesis of invasive cells, a simple and visual assay, adaptable to reproduce collective cell migration in vitro To date, in its diverse optimized variants, the chemoinvasion assay is still widely used, contributing to novel data production. In the era of precision medicine and next-generation sequencing, the cheap, fast, and reproducible chemoinvasion assay may have further developments, including possible applications in the investigations on cancer stem cells, immunity and immune modulators, applications with siRNA silencing, selection of aggressive cell populations, and phenotypes and genetic evaluations. Cancer Res; 76(16); 4595-7. ©2016 AACR.See related article by Albini A et al., Cancer Res 1987;47:3239-45Visit the Cancer Research 75(th) Anniversary timeline. PMID:27528578

  19. Keystone predators (eastern newts, Notophthalmus viridescens) reduce the impacts of an aquatic invasive species

    USGS Publications Warehouse

    Smith, Kimberly G.

    2006-01-01

    Predation, competition, and their interaction are known to be important factors that influence the structure of ecological communities. In particular, in those cases where a competitive hierarchy exists among prey species, the presence of certain keystone predators can result in enhanced diversity in the prey community. However, little is known regarding the influence of keystone predator presence on invaded prey communities. Given the widespread occurrence of invasive species and substantial concern regarding their ecological impacts, studies on this topic are needed. In this study I used naturalistic replications of an experimental tadpole assemblage to assess the influence of predatory eastern newts, Notophthalmus viridescens, on the outcome of interspecific competition among native and nonindigenous tadpoles. When newts were absent, the presence of the tadpoles of one invasive species, the Cuban treefrog, Osteopilus septentrionalis, resulted in decreased survival and growth rate of the dominant native species, Bufo terrestris, and dominance of the tadpole assemblage by O. septentrionalis. However, the presence of one adult newt generally reduced or eliminated the negative impacts of O. septentrionalis tadpoles, resulting in comparable survival and performance of native species in invaded and noninvaded treatments. Differential mortality among the tadpole species suggests that newts preyed selectively on O. septentrionalis tadpoles, supporting the hypothesis that newts acted as keystone predators in the invaded assemblage. The presence of nonindigenous larval cane toads, Bufo marinus, did not significantly affect native species, and this species was not negatively affected by the presence of newts. Collectively, these results suggest that eastern newts significantly modified the competitive hierarchy of the invaded tadpole assemblage and reduced the impacts of a competitively superior invasive species. If general, these results suggest that the presence of

  20. Comparing the ecological impacts of native and invasive crayfish: could native species' translocation do more harm than good?

    PubMed

    James, J; Slater, F M; Vaughan, I P; Young, K A; Cable, J

    2015-05-01

    Biological invasions are a principal threat to global biodiversity. Omnivores, such as crayfish, are among the most important groups of invaders. Their introduction often results in biodiversity loss, particularly of their native counterparts. Managed relocations of native crayfish from areas under threat from invasive crayfish into isolated 'ark sites' are sometimes suggested as a conservation strategy for native crayfish; however, such relocations may have unintended detrimental consequences for the recipient ecosystem. Despite this, there have been few attempts to quantify the relative impacts of native and invasive crayfish on aquatic ecosystems. To address this deficiency we conducted a meta-analysis on the effects of native and invasive crayfish on nine ecosystem components: decomposition rate, primary productivity, plant biomass, invertebrate density, biomass and diversity, fish biomass and refuge use, and amphibian larval survival. Native and invasive crayfish significantly reduced invertebrate density and biomass, fish biomass and amphibian survival rate and significantly increased decomposition rates. Invasive crayfish also significantly reduced plant biomass and invertebrate diversity and increased primary productivity. These results show that native and invasive crayfish have wide-ranging impacts on aquatic ecosystems that may be exacerbated for invasive species. Subsequent analysis showed that the impacts of invasive crayfish were significantly greater, in comparison to native crayfish, for decomposition and primary productivity but not invertebrate density, biomass and diversity. Overall, our findings reconfirm the ecosystem altering abilities of both native and invasive crayfish, enforcing the need to carefully regulate managed relocations of native species as well as to develop control programs for invasives. PMID:25549809

  1. Landscape determinants of nonindigenous fish invasions

    USGS Publications Warehouse

    Ross, R.M.; Lellis, W.A.; Bennett, R.M.; Johnson, C.S.

    2001-01-01

    Much has been written about the influence of exotic or nonindigenous species on natural habitats and communities of organisms, but little is known of the physical or biological conditions that lead to successful invasion of native habitats and communities by exotics. We studied invasivity factors in headwater streams of the Susquehanna River West Branch, which drains portions of the northern Appalachian Plateau. A replicated (two major tributaries) 3 ?? 3 factorial design was used to determine landscape effects of size (stream order) and quality (land use) on abiotic (physical and chemical) and biotic (fish community structure and function) stream attributes. Seven (21%) of thirty-four fish species (brown trout, common carp, mimic shiner, bluegill, smallmouth bass, fantail darter, and banded darter) collected in the eighteen streams sampled were nonindigenous to the basin. Watershed size (stream orders 1, 3, and 5) significantly affected stream geomorphologic and habitat variables (gradient, width, depth, current velocity, diel water temperature, bank overhang, canopy cover, and woody debris density) but not water-quality variables, while land use in watersheds (conservation, mining, and agriculture) significantly affected measured water-quality variables (alkalinity and concentrations of manganese, calcium, chloride, nitrate, and total dissolved solids) but not stream physical or habitat quality. Both watershed size and land use affected fish-community variables such as presence of particular species, species density, species diversity, tolerance diversity, and mean fish size, but in both cases the effect was transparent to native-origin status of fish species. No relationships were found between occurrence of nonindigenous species in watersheds and trophic structure or functional diversity. Therefore, the hypothesis that reduced species diversity increases vulnerability to nonindigenous species was not supported. However, the spatial variation associated with

  2. Valuing Diversity

    PubMed Central

    Fryer, Roland G.; Loury, Glenn C.

    2014-01-01

    This paper explores the economics of diversity-enhancing policies. A model is proposed in which heterogeneous agents, distinguished by skill level and social identity, purchase productive opportunities in a competitive market. We analyze policies designed to raise the status of a disadvantaged identity group. When agent identity is contractible, efficient policy grants preferred access to slots but offers no direct assistance for acquiring skills. When identity is not contractible, efficient policy provides universal subsidies to skill development when the fraction of the disadvantaged group at the skill development margin is larger than their share at the slot assignment margin. PMID:25525280

  3. Placing invasive species management in a spatiotemporal context.

    PubMed

    Baker, Christopher M; Bode, Michael

    2016-04-01

    Invasive species are a worldwide issue, both ecologically and economically. A large body of work focuses on various aspects of invasive species control, including how to allocate control efforts to eradicate an invasive population as cost effectively as possible: There are a diverse range of invasive species management problems, and past mathematical analyses generally focus on isolated examples, making it hard to identify and understand parallels between the different contexts. In this study, we use a single spatiotemporal model to tackle the problem of allocating control effort for invasive species when suppressing an island invasive species, and for long-term spatial suppression projects. Using feral cat suppression as an illustrative example, we identify the optimal resource allocation for island and mainland suppression projects. Our results demonstrate how using a single model to solve different problems reveals similar characteristics of the solutions in different scenarios. As well as illustrating the insights offered by linking problems through a spatiotemporal model, we also derive novel and practically applicable results for our case studies. For temporal suppression projects on islands, we find that lengthy projects are more cost effective and that rapid control projects are only economically cost effective when population growth rates are high or diminishing returns on control effort are low. When suppressing invasive species around conservation assets (e.g., national parks or exclusion fences), we find that the size of buffer zones should depend on the ratio of the species growth and spread rate. PMID:27411245

  4. 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…

  5. 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

  6. 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

  7. 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.

  8. Shikonin inhibits invasiveness of osteosarcoma through MMP13 suppression.

    PubMed

    Deng, Biyong; Qiu, Bing

    2015-12-01

    Osteosarcoma (OS) is the most common primary malignant bone tumor, notorious for its metastasis. We have recently shown that shikonin, an effective constituent extracted from Chinese medicinal herb, induces necroptosis in OS cells. Nevertheless, the effects of low-dose shikonin on the invasiveness of OS cells are unknown. Here, we showed that shikonin dose-dependently decreased OS cell invasiveness in both scratch wound healing assay and transwell cell migration assay. Moreover, the direct target of shikonin on cell invasiveness was found to be matrix metalloproteinase (MMP)-13. Further, the inhibitory effects of shikonin on cell invasiveness were completely abolished in MMP13-overexpressing OS cells. Together, these data suggest that shikonin may suppress OS invasiveness through MMP13 suppression. Thus, our data highlight a previous unappreciated role for shikonin in suppressing OS cell metastasis. PMID:26104765

  9. 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

  10. RESTORING SPECIES RICHNESS AND DIVERSITY IN A RUSSIAN KNAPWEED (ACROPTILON REPENS)-INFESTED RIPARIAN PLANT COMMUNITY USING HERBICIDES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Species richness and diversity are important indicators of ecosystem function and may be related to plant community resistance to invasion by non-indigenous species. Knowledge about the influence of various strategies on species richness and diversity is central to making wise invasive plant manage...

  11. 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.

  12. Grazing maintains native plant diversity and promotes community stability in an annual grassland.

    PubMed

    Beck, Jared J; Hernández, Daniel L; Pasari, Jae R; Zavaleta, Erika S

    2015-07-01

    Maintaining native biodiversity in grasslands requires management and mitigation of anthropogenic changes that have altered resource availability, grazing regimes, and community composition. In California (USA), high levels of atmospheric nitrogen (N) deposition have facilitated the invasion of exotic grasses, posing a threat to the diverse plant and insect communities endemic to serpentine grasslands. Cattle grazing has been employed to mitigate the consequences of exotic grass invasion, but the ecological effects of grazing in this system are not fully understood. To characterize the effects of realistic N deposition on serpentine plant communities and to evaluate the efficacy of grazing as a management tool, we performed a factorial experiment adding N and excluding large herbivores in California's largest serpentine grassland. Although we observed significant interannual variation in community composition related to climate in our six-year study, exotic cover was consistently and negatively correlated with native plant richness. Sustained low-level N addition did not influence plant community composition, but grazing reduced grass abundance while maintaining greater native forb cover, native plant diversity, and species richness in comparison to plots excluding large herbivores. Furthermore, grazing increased the temporal stability of plant communities by decreasing year-to-year variation in native forb cover, native plant diversity, and native species richness. Taken together, our findings demonstrate that moderate-intensity cattle grazing can be used to restrict the invasive potential of exotic grasses and maintain native plant communities in serpentine grasslands. We hypothesize that the reduced temporal variability in serpentine plant communities managed by grazing may directly benefit populations of the threatened Edith's Bay checkerspot butterfly (Euphydryas editha bayensis). PMID:26485954

  13. Trophic network architecture of root-associated bacterial communities determines pathogen invasion and plant health.

    PubMed

    Wei, Zhong; Yang, Tianjie; Friman, Ville-Petri; Xu, Yangchun; Shen, Qirong; Jousset, Alexandre

    2015-01-01

    Host-associated bacterial communities can function as an important line of defence against pathogens in animals and plants. Empirical evidence and theoretical predictions suggest that species-rich communities are more resistant to pathogen invasions. Yet, the underlying mechanisms are unclear. Here, we experimentally test how the underlying resource competition networks of resident bacterial communities affect invasion resistance to the plant pathogen Ralstonia solanacearum in microcosms and in tomato plant rhizosphere. We find that bipartite resource competition networks are better predictors of invasion resistance compared with resident community diversity. Specifically, communities with a combination of stabilizing configurations (low nestedness and high connectance), and a clear niche overlap with the pathogen, reduce pathogen invasion success, constrain pathogen growth within invaded communities and have lower levels of diseased plants in greenhouse experiments. Bacterial resource competition network characteristics can thus be important in explaining positive diversity-invasion resistance relationships in bacterial rhizosphere communities. PMID:26400552

  14. Predator diversity effects in an exotic freshwater food web.

    PubMed

    Naddafi, Rahmat; Rudstam, Lars G

    2013-01-01

    Cascading trophic interactions are often defined as the indirect effects of a predator on primary producers through the effect of the predator on herbivores. These effects can be both direct through removal of herbivores [density-mediated indirect interactions (DMIIs)] or indirect through changes in the behavior of the herbivores [trait-mediated indirect interactions (TMIIs)]. How the relative importance of these two indirect interactions varies with predator diversity remains poorly understood. We tested the effect of predator diversity on both TMIIs and DMIIs on phytoplankton using two competitive invasive dreissenid mussel species (zebra mussel and quagga mussel) as the herbivores and combinations of one, two or all three species of the predators pumpkinseed sunfish, round goby, and rusty crayfish. Predators had either direct access to mussels and induced both TMII and DMII, or no direct access and induced only TMII through the presence of risk cues. In both sets of treatments, the predators induced a trophic cascade which resulted in more phytoplankton remaining with predators present than with only mussels present. The trophic cascade was weaker in three-predator and two-predator treatments than in one-predator treatments when predators had direct access to dreissenids (DMIIs and TMIIs). Crayfish had higher cascading effects on phytoplankton than both pumpkinseed and round goby. Increased predator diversity decreased the strength of DMIIs but had no effect on the strength of TMIIs. The strength of TMIIs was higher with zebra than quagga mussels. Our study suggests that inter-specific interference among predators in multi-species treatments weakens the consumptive cascading effects of predation on lower trophic levels whereas the importance of predator diversity on trait mediated effects depends on predator identity. PMID:23991126

  15. Minimally Invasive Transforaminal Lumbar Interbody Fusion.

    PubMed

    Ahn, Junyoung; Tabaraee, Ehsan; Singh, Kern

    2015-07-01

    Minimally invasive transforaminal lumbar interbody fusion (MIS TLIF) is performed via tubular dilators thereby preserving the integrity of the paraspinal musculature. The decreased soft tissue disruption in the MIS technique has been associated with significantly decreased blood loss, shorter length of hospitalization, and an expedited return to work while maintaining comparable arthrodesis rates when compared with the open technique particularly in the setting of spondylolisthesis (isthmic and degenerative), recurrent symptomatic disk herniation, spinal stenosis, pseudoarthrosis, iatrogenic instability, and spinal trauma. The purpose of this article and the accompanying video wass to demonstrate the techniques for a primary, single-level MIS TLIF. PMID:26079840

  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. Reconstructing the invasion history of Heracleum persicum (Apiaceae) into Europe.

    PubMed

    Rijal, Dilli P; Alm, Torbjørn; Jahodová, Šárka; Stenøien, Hans K; Alsos, Inger G

    2015-11-01

    Sparse, incomplete and inappropriate historical records of invasive species often hamper invasive species management interventions. Population genetic analyses of invaders might provide a suitable context for the identification of their source populations and possible introduction routes. Here, we describe the population genetics of Heracleum persicum Desf. ex Fisch and trace its route of introduction into Europe. Microsatellite markers revealed a significantly higher genetic diversity of H. persicum in its native range, and the loss of diversity in the introduced range may be attributed to a recent genetic bottleneck. Bayesian cluster analysis on regional levels identified three and two genetic clusters in the native and the introduced ranges, respectively. A global structure analysis revealed two worldwide distinct genetic groups: one primarily in Iran and Denmark, the other primarily in Norway. There were also varying degrees of admixture in England, Sweden, Finland and Latvia. Approximate Bayesian computation indicated two independent introductions of H. persicum from Iran to Europe: the first one in Denmark and the second one in England. Finland was subsequently colonized by English populations. In contrast to the contemporary hypothesis of English origin of Norwegian populations, we found Finland to be a more likely source for Norwegian populations, a scenario supported by higher estimated historical migration from Finland to Norway. Genetic diversity per se is not a primary determinant of invasiveness in H. persicum. Our results indicate that, due to either pre-adaptations or rapid local adaptations, introduced populations may have acquired invasiveness after subsequent introductions, once a suitable environment was encountered. PMID:26454010

  18. Differential plant invasiveness is not always driven by host promiscuity with bacterial symbionts.

    PubMed

    Klock, Metha M; Barrett, Luke G; Thrall, Peter H; Harms, Kyle E

    2016-01-01

    Identification of mechanisms that allow some species to outcompete others is a fundamental goal in ecology and invasive species management. One useful approach is to examine congeners varying in invasiveness in a comparative framework across native and invaded ranges. Acacia species have been widely introduced outside their native range of Australia, and a subset of these species have become invasive in multiple parts of the world. Within specific regions, the invasive status of these species varies. Our study examined whether a key mechanism in the life history of Acacia species, the legume-rhizobia symbiosis, influences acacia invasiveness on a regional scale. To assess the extent to which species varying in invasiveness correspondingly differ with regard to the diversity of rhizobia they associate with, we grew seven Acacia species ranging in invasiveness in California in multiple soils from both their native (Australia) and introduced (California) ranges. In particular, the aim was to determine whether more invasive species formed symbioses with a wider diversity of rhizobial strains (i.e. are more promiscuous hosts). We measured and compared plant performance, including aboveground biomass, survival, and nodulation response, as well as rhizobial community composition and richness. Host promiscuity did not differ among invasiveness categories. Acacia species that varied in invasiveness differed in aboveground biomass for only one soil and did not differ in survival or nodulation within individual soils. In addition, acacias did not differ in rhizobial richness among invasiveness categories. However, nodulation differed between regions and was generally higher in the native than introduced range. Our results suggest that all Acacia species introduced to California are promiscuous hosts and that host promiscuity per se does not explain the observed differences in invasiveness within this region. Our study also highlights the utility of assessing potential

  19. Differential plant invasiveness is not always driven by host promiscuity with bacterial symbionts

    PubMed Central

    Klock, Metha M.; Barrett, Luke G.; Thrall, Peter H.; Harms, Kyle E.

    2016-01-01

    Identification of mechanisms that allow some species to outcompete others is a fundamental goal in ecology and invasive species management. One useful approach is to examine congeners varying in invasiveness in a comparative framework across native and invaded ranges. Acacia species have been widely introduced outside their native range of Australia, and a subset of these species have become invasive in multiple parts of the world. Within specific regions, the invasive status of these species varies. Our study examined whether a key mechanism in the life history of Acacia species, the legume-rhizobia symbiosis, influences acacia invasiveness on a regional scale. To assess the extent to which species varying in invasiveness correspondingly differ with regard to the diversity of rhizobia they associate with, we grew seven Acacia species ranging in invasiveness in California in multiple soils from both their native (Australia) and introduced (California) ranges. In particular, the aim was to determine whether more invasive species formed symbioses with a wider diversity of rhizobial strains (i.e. are more promiscuous hosts). We measured and compared plant performance, including aboveground biomass, survival, and nodulation response, as well as rhizobial community composition and richness. Host promiscuity did not differ among invasiveness categories. Acacia species that varied in invasiveness differed in aboveground biomass for only one soil and did not differ in survival or nodulation within individual soils. In addition, acacias did not differ in rhizobial richness among invasiveness categories. However, nodulation differed between regions and was generally higher in the native than introduced range. Our results suggest that all Acacia species introduced to California are promiscuous hosts and that host promiscuity per se does not explain the observed differences in invasiveness within this region. Our study also highlights the utility of assessing potential

  20. Minimally Invasive Surgery for Inflammatory Bowel Disease

    PubMed Central

    Holder-Murray, Jennifer; Marsicovetere, Priscilla

    2015-01-01

    Abstract: Surgical management of inflammatory bowel disease is a challenging endeavor given infectious and inflammatory complications, such as fistula, and abscess, complex often postoperative anatomy, including adhesive disease from previous open operations. Patients with Crohn's disease and ulcerative colitis also bring to the table the burden of their chronic illness with anemia, malnutrition, and immunosuppression, all common and contributing independently as risk factors for increased surgical morbidity in this high-risk population. However, to reduce the physical trauma of surgery, technologic advances and worldwide experience with minimally invasive surgery have allowed laparoscopic management of patients to become standard of care, with significant short- and long-term patient benefits compared with the open approach. In this review, we will describe the current state-of the-art for minimally invasive surgery for inflammatory bowel disease and the caveats inherent with this practice in this complex patient population. Also, we will review the applicability of current and future trends in minimally invasive surgical technique, such as laparoscopic “incisionless,” single-incision laparoscopic surgery (SILS), robotic-assisted, and other techniques for the patient with inflammatory bowel disease. There can be no doubt that minimally invasive surgery has been proven to decrease the short- and long-term burden of surgery of these chronic illnesses and represents high-value care for both patient and society. PMID:25989341

  1. 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.

  2. 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.

  3. Diverse Classrooms, Diverse Curriculum, Diverse Complications: Three Teacher Perspectives

    ERIC Educational Resources Information Center

    Ungemah, Lori D.

    2015-01-01

    Racial, ethnic, linguistic, and religious diversity continues to increase in classrooms. Many call for a more diverse curriculum, but curricular diversity brings its own challenges to both teachers and students. These three vignettes are drawn from my ethnographic data at Atlantic High School in Brooklyn, New York, where I worked for ten years as…

  4. Global patterns in threats to vertebrates by biological invasions.

    PubMed

    Bellard, C; Genovesi, P; Jeschke, J M

    2016-01-27

    Biological invasions as drivers of biodiversity loss have recently been challenged. Fundamentally, we must know where species that are threatened by invasive alien species (IAS) live, and the degree to which they are threatened. We report the first study linking 1372 vertebrates threatened by more than 200 IAS from the completely revised Global Invasive Species Database. New maps of the vulnerability of threatened vertebrates to IAS permit assessments of whether IAS have a major influence on biodiversity, and if so, which taxonomic groups are threatened and where they are threatened. We found that centres of IAS-threatened vertebrates are concentrated in the Americas, India, Indonesia, Australia and New Zealand. The areas in which IAS-threatened species are located do not fully match the current hotspots of invasions, or the current hotspots of threatened species. The relative importance of biological invasions as drivers of biodiversity loss clearly varies across regions and taxa, and changes over time, with mammals from India, Indonesia, Australia and Europe are increasingly being threatened by IAS. The chytrid fungus primarily threatens amphibians, whereas invasive mammals primarily threaten other vertebrates. The differences in IAS threats between regions and taxa can help efficiently target IAS, which is essential for achieving the Strategic Plan 2020 of the Convention on Biological Diversity. PMID:26817767

  5. Coupling legacy geomorphic surface facies to riparian vegetation: Assessing red cedar invasion along the Missouri River downstream of Gavins Point dam, South Dakota

    NASA Astrophysics Data System (ADS)

    Greene, Samantha L.; Knox, James C.

    2014-01-01

    Floods increase fluvial complexity by eroding established surfaces and creating new alluvial surfaces. As dams regulate channel flow, fluvial complexity often decreases and the hydro-eco-geomorphology of the riparian habitat changes. Along the Missouri River, flow regulation resulted in channel incision of 1-3 m within the study area and disconnected the pre-dam floodplain from the channel. Evidence of fluvial complexity along the pre-dam Missouri River floodplain can be observed through the diverse depositional environments represented by areas of varying soil texture. This study evaluates the role of flow regulation and depositional environment along the Missouri River in the riparian invasion of red cedar downstream of Gavins Point dam, the final dam on the Missouri River. We determine whether invasion began before or after flow regulation, determine patterns of invasion using Bayesian t-tests, and construct a Bayesian multivariate linear model of invaded surfaces. We surveyed 59 plots from 14 riparian cottonwood stands for tree age, plot composition, plot stem density, and soil texture. Red cedars existed along the floodplain prior to regulation, but at a much lower density than today. We found 2 out of 565 red cedars established prior to regulation. Our interpretation of depositional environments shows that the coarser, sandy soils reflect higher energy depositional pre-dam surfaces that were geomorphically active islands and point bars prior to flow regulation and channel incision. The finer, clayey soils represent lower energy depositional pre-dam surfaces, such as swales or oxbow depressions. When determining patterns of invasion for use in a predictive statistical model, we found that red cedar primarily establishes on the higher energy depositional pre-dam surfaces. In addition, as cottonwood age and density decrease, red cedar density tends to increase. Our findings indicate that flow regulation caused hydrogeomorphic changes within the study area that

  6. Rapid increase in growth and productivity can aid invasions by a non-native tree

    PubMed Central

    Dudeque Zenni, Rafael; Lacerda da Cunha, Wanderson; Sena, Guilherme

    2016-01-01

    Research on biological invasions has produced detailed theories describing range expansions of introduced populations. However, current knowledge of evolutionary factors associated with invasive range expansions, especially those related to rapid evolution of long-lived organisms, is still rudimentary. Here, we used a system of six 40-year-old invasive pine populations that originated from replicated introduction events to study evolution in productivity, growth, and chemical defence traits. We tested the hypotheses that invasive populations were undergoing rapid phenotypic change as populations spread, that populations exhibit trade-offs between evolution in growth and chemical defences, and that rates of rapid evolution in plant growth and productivity effect rates of invasion. Although all invasions started from replicated pools of genetic material and equal propagule pressure, we found divergence in mean values for the six invasive populations in the six traits measured. Not only were there between-population variations but also invasive populations were also rapidly changing along each invasive population expansion. Two populations displayed greater leaf areas (LAs) and smaller specific LAs (SLAs) during range expansion. Four populations had faster growth rates at the leading edge of the invasion front in comparison with plants at the rear edge. In terms of total plant defences, non-volatile resin increased in plants along one invasion gradient and decreased in a second, total needle phenolics increased in plants along one invasion gradient and total wood phenolics increased in plants along the one invasion gradient and decreased in a second. We found no trade-offs between investments in growth and chemical defence. Also, faster rates of change in growth rate and LA were positively associated with greater dispersal distances of invasive populations, suggesting rapid evolution may increase invasiveness. Understanding the roles of both natural and human

  7. Rapid increase in growth and productivity can aid invasions by a non-native tree.

    PubMed

    Dudeque Zenni, Rafael; Lacerda da Cunha, Wanderson; Sena, Guilherme

    2016-01-01

    Research on biological invasions has produced detailed theories describing range expansions of introduced populations. However, current knowledge of evolutionary factors associated with invasive range expansions, especially those related to rapid evolution of long-lived organisms, is still rudimentary. Here, we used a system of six 40-year-old invasive pine populations that originated from replicated introduction events to study evolution in productivity, growth, and chemical defence traits. We tested the hypotheses that invasive populations were undergoing rapid phenotypic change as populations spread, that populations exhibit trade-offs between evolution in growth and chemical defences, and that rates of rapid evolution in plant growth and productivity effect rates of invasion. Although all invasions started from replicated pools of genetic material and equal propagule pressure, we found divergence in mean values for the six invasive populations in the six traits measured. Not only were there between-population variations but also invasive populations were also rapidly changing along each invasive population expansion. Two populations displayed greater leaf areas (LAs) and smaller specific LAs (SLAs) during range expansion. Four populations had faster growth rates at the leading edge of the invasion front in comparison with plants at the rear edge. In terms of total plant defences, non-volatile resin increased in plants along one invasion gradient and decreased in a second, total needle phenolics increased in plants along one invasion gradient and total wood phenolics increased in plants along the one invasion gradient and decreased in a second. We found no trade-offs between investments in growth and chemical defence. Also, faster rates of change in growth rate and LA were positively associated with greater dispersal distances of invasive populations, suggesting rapid evolution may increase invasiveness. Understanding the roles of both natural and human

  8. 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

  9. Ultrasonic non invasive techniques for microbiological instrumentation

    NASA Astrophysics Data System (ADS)

    Elvira, L.; Sierra, C.; Galán, B.; Resa, P.

    2010-01-01

    Non invasive techniques based on ultrasounds have advantageous features to study, characterize and monitor microbiological and enzymatic reactions. These processes may change the sound speed, viscosity or particle distribution size of the medium where they take place, which makes possible their analysis using ultrasonic techniques. In this work, two different systems for the analysis of microbiological liquid media based on ultrasounds are presented. In first place, an industrial application based on an ultrasonic monitoring technique for microbiological growth detection in milk is shown. Such a system may improve the quality control strategies in food production factories, being able to decrease the time required to detect possible contaminations in packed products. Secondly, a study about the growing of the Escherichia coli DH5 α in different conditions is presented. It is shown that the use of ultrasonic non invasive characterization techniques in combination with other conventional measurements like optical density provides complementary information about the metabolism of these bacteria.

  10. 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

  11. 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

  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. The Chief Diversity Officer

    ERIC Educational Resources Information Center

    Williams, Damon; Wade-Golden, Katrina

    2007-01-01

    Numerous institutions are moving toward the chief diversity officer model of leading and managing diversity in higher education. These officers carry formal administrative titles and ranks that range from vice president for institutional diversity to associate vice chancellor for diversity and climate and dean of diversity and academic engagement.…

  14. Schwann cells induce cancer cell dispersion and invasion

    PubMed Central

    Deborde, Sylvie; Lyubchik, Anna; Zhou, Yi; He, Shizhi; McNamara, William F.; Chernichenko, Natalya; Lee, Sei-Young; Barajas, Fernando; Chen, Chun-Hao; Bakst, Richard L.; Vakiani, Efsevia; He, Shuangba; Hall, Alan; Wong, Richard J.

    2016-01-01

    Nerves enable cancer progression, as cancers have been shown to extend along nerves through the process of perineural invasion, which carries a poor prognosis. Furthermore, the innervation of some cancers promotes growth and metastases. It remains unclear, however, how nerves mechanistically contribute to cancer progression. Here, we demonstrated that Schwann cells promote cancer invasion through direct cancer cell contact. Histological evaluation of murine and human cancer specimens with perineural invasion uncovered a subpopulation of Schwann cells that associates with cancer cells. Coculture of cancer cells with dorsal root ganglion extracts revealed that Schwann cells direct cancer cells to migrate toward nerves and promote invasion in a contact-dependent manner. Upon contact, Schwann cells induced the formation of cancer cell protrusions in their direction and intercalated between the cancer cells, leading to cancer cell dispersion. The formation of these processes was dependent on Schwann cell expression of neural cell adhesion molecule 1 (NCAM1) and ultimately promoted perineural invasion. Moreover, NCAM1-deficient mice showed decreased neural invasion and less paralysis. Such Schwann cell behavior reflects normal Schwann cell programs that are typically activated in nerve repair but are instead exploited by cancer cells to promote perineural invasion and cancer progression. PMID:26999607

  15. Out of the Black Sea: phylogeography of the invasive killer shrimp Dikerogammarus villosus across Europe.

    PubMed

    Rewicz, Tomasz; Wattier, Remi; Grabowski, Michał; Rigaud, Thierry; Bącela-Spychalska, Karolina

    2015-01-01

    The amphipod Dikerogammarus villosus has colonized most of the European main inland water bodies in less than 20 years, having deteriorating effect on the local benthic communities. Our aim was to reveal the species phylogeography in the native Black Sea area, to define the source populations for the colonization routes in continental Europe and for the newly established UK populations. We tested for the loss of genetic diversity between source and invasive populations as well as along invasion route. We tested also for isolation by distance. Thirty three native and invasive populations were genotyped for mtDNA (COI, 16S) and seven polymorphic nuclear microsatellites to assess cryptic diversity (presence of deeply divergent lineages), historical demography, level of diversity within lineage (e.g., number of alleles), and population structure. A wide range of methods was used, including minimum spanning network, molecular clock, Bayesian clustering and Mantel test. Our results identified that sea level and salinity changes during Pleistocene impacted the species phylogeography in the Black Sea native region with four differentiated populations inhabiting, respectively, the Dnieper, Dniester, Danube deltas and Durungol liman. The invasion of continental Europe is associated with two sources, i.e., the Danube and Dnieper deltas, which gave origin to two independent invasion routes (Western and Eastern) for which no loss of diversity and no isolation by distance were observed. The UK population has originated in the Western Route and, despite very recent colonization, no drastic loss of diversity was observed. The results show that the invasion of the killer shrimp is not associated with the costs of loosing genetic diversity, which may contribute to the success of this invader in the newly colonized areas. Additionally, while it has not yet occurred, it might be expected that future interbreeding between the genetically diversified populations from two independent

  16. Out of the Black Sea: Phylogeography of the Invasive Killer Shrimp Dikerogammarus villosus across Europe

    PubMed Central

    Rewicz, Tomasz; Wattier, Remi; Grabowski, Michał; Rigaud, Thierry; Bącela-Spychalska, Karolina

    2015-01-01

    The amphipod Dikerogammarus villosus has colonized most of the European main inland water bodies in less than 20 years, having deteriorating effect on the local benthic communities. Our aim was to reveal the species phylogeography in the native Black Sea area, to define the source populations for the colonization routes in continental Europe and for the newly established UK populations. We tested for the loss of genetic diversity between source and invasive populations as well as along invasion route. We tested also for isolation by distance. Thirty three native and invasive populations were genotyped for mtDNA (COI, 16S) and seven polymorphic nuclear microsatellites to assess cryptic diversity (presence of deeply divergent lineages), historical demography, level of diversity within lineage (e.g., number of alleles), and population structure. A wide range of methods was used, including minimum spanning network, molecular clock, Bayesian clustering and Mantel test. Our results identified that sea level and salinity changes during Pleistocene impacted the species phylogeography in the Black Sea native region with four differentiated populations inhabiting, respectively, the Dnieper, Dniester, Danube deltas and Durungol liman. The invasion of continental Europe is associated with two sources, i.e., the Danube and Dnieper deltas, which gave origin to two independent invasion routes (Western and Eastern) for which no loss of diversity and no isolation by distance were observed. The UK population has originated in the Western Route and, despite very recent colonization, no drastic loss of diversity was observed. The results show that the invasion of the killer shrimp is not associated with the costs of loosing genetic diversity, which may contribute to the success of this invader in the newly colonized areas. Additionally, while it has not yet occurred, it might be expected that future interbreeding between the genetically diversified populations from two independent

  17. 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

  18. 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.

  19. 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...

  20. 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

  1. MSX2 Induces Trophoblast Invasion in Human Placenta.

    PubMed

    Liang, Hao; Zhang, Qian; Lu, Junjie; Yang, Genling; Tian, Na; Wang, Xiaojie; Tan, Yi; Tan, Dongmei

    2016-01-01

    Normal implantation depends on appropriate trophoblast growth and invasion. Inadequate trophoblast invasion results in pregnancy-related disorders, such as early miscarriage and pre-eclampsia, which are dangerous to both the mother and fetus. Msh Homeobox 2 (MSX2), a member of the MSX family of homeobox proteins, plays a significant role in the proliferation and differentiation of various cells and tissues, including ectodermal organs, teeth, and chondrocytes. Recently, MSX2 was found to play important roles in the invasion of cancer cells into adjacent tissues via the epithelial-mesenchymal transition (EMT). However, the role of MSX2 in trophoblastic invasion during placental development has yet to be explored. In the present study, we detected MSX2 expression in cytotrophoblast, syncytiotrophoblast, and extravillous cytotrophoblast cells of first or third trimester human placentas via immunohistochemistry analysis. Furthermore, we found that the in vitro invasive ability of HTR8/SVneo cells was enhanced by exogenous overexpression of MSX2, and that this effect was accompanied by increased protein expression of matrix metalloproteinase-2 (MMP-2), vimentin, and β-catenin. Conversely, treatment of HTR8/SVneo cells with MSX2-specific siRNAs resulted in decreased protein expression of MMP-2, vimentin, and β-catenin, and reduced invasion levels in a Matrigel invasion test. Notably, however, treatment with the MSX2 overexpression plasmid and the MSX2 siRNAs had no effect on the mRNA expression levels of β-catenin. Meanwhile, overexpression of MSX2 and treatment with the MSX2-specific siRNA resulted in decreased and increased E-cadherin expression, respectively, in JEG-3 cells. Lastly, the protein expression levels of MSX2 were significantly lower in human pre-eclamptic placental villi than in the matched control placentas. Collectively, our results suggest that MSX2 may induce human trophoblast cell invasion, and dysregulation of MSX2 expression may be associated

  2. MSX2 Induces Trophoblast Invasion in Human Placenta

    PubMed Central

    Lu, Junjie; Yang, Genling; Tian, Na; Wang, Xiaojie; Tan, Yi; Tan, Dongmei

    2016-01-01

    Normal implantation depends on appropriate trophoblast growth and invasion. Inadequate trophoblast invasion results in pregnancy-related disorders, such as early miscarriage and pre-eclampsia, which are dangerous to both the mother and fetus. Msh Homeobox 2 (MSX2), a member of the MSX family of homeobox proteins, plays a significant role in the proliferation and differentiation of various cells and tissues, including ectodermal organs, teeth, and chondrocytes. Recently, MSX2 was found to play important roles in the invasion of cancer cells into adjacent tissues via the epithelial-mesenchymal transition (EMT). However, the role of MSX2 in trophoblastic invasion during placental development has yet to be explored. In the present study, we detected MSX2 expression in cytotrophoblast, syncytiotrophoblast, and extravillous cytotrophoblast cells of first or third trimester human placentas via immunohistochemistry analysis. Furthermore, we found that the in vitro invasive ability of HTR8/SVneo cells was enhanced by exogenous overexpression of MSX2, and that this effect was accompanied by increased protein expression of matrix metalloproteinase-2 (MMP-2), vimentin, and β-catenin. Conversely, treatment of HTR8/SVneo cells with MSX2-specific siRNAs resulted in decreased protein expression of MMP-2, vimentin, and β-catenin, and reduced invasion levels in a Matrigel invasion test. Notably, however, treatment with the MSX2 overexpression plasmid and the MSX2 siRNAs had no effect on the mRNA expression levels of β-catenin. Meanwhile, overexpression of MSX2 and treatment with the MSX2-specific siRNA resulted in decreased and increased E-cadherin expression, respectively, in JEG-3 cells. Lastly, the protein expression levels of MSX2 were significantly lower in human pre-eclamptic placental villi than in the matched control placentas. Collectively, our results suggest that MSX2 may induce human trophoblast cell invasion, and dysregulation of MSX2 expression may be associated

  3. No evolution of increased competitive ability or decreased allocation to defense in Melaleuca quinquenervia since release from natural enemies

    Technology Transfer Automated Retrieval System (TEKTRAN)

    If invasive plants are released from natural enemies in their introduced range, they may evolve decreased allocation to defense and increased growth, as predicted by the evolution of increased competitive ability (EICA) hypothesis. A field experiment using the invasive tree Melaleuca quinquenervia ...

  4. Drosophila suzukii: The Genetic Footprint of a Recent, Worldwide Invasion

    PubMed Central

    Adrion, Jeffrey R.; Kousathanas, Athanasios; Pascual, Marta; Burrack, Hannah J.; Haddad, Nick M.; Bergland, Alan O.; Machado, Heather; Sackton, Timothy B.; Schlenke, Todd A.; Watada, Masayoshi; Wegmann, Daniel; Singh, Nadia D.

    2014-01-01

    Native to Asia, the soft-skinned fruit pest Drosophila suzukii has recently invaded the United States and Europe. The eastern United States represents the most recent expansion of their range, and presents an opportunity to test alternative models of colonization history. Here, we investigate the genetic population structure of this invasive fruit fly, with a focus on the eastern United States. We sequenced six X-linked gene fragments from 246 individuals collected from a total of 12 populations. We examine patterns of genetic diversity within and between populations and explore alternative colonization scenarios using approximate Bayesian computation. Our results indicate high levels of nucleotide diversity in this species and suggest that the recent invasions of Europe and the continental United States are independent demographic events. More broadly speaking, our results highlight the importance of integrating population structure into demographic models, particularly when attempting to reconstruct invasion histories. Finally, our simulation results illustrate the general challenge in reconstructing invasion histories using genetic data and suggest that genome-level data are often required to distinguish among alternative demographic scenarios. PMID:25158796

  5. The Effect of Urbanization on Ant Abundance and Diversity: A Temporal Examination of Factors Affecting Biodiversity

    PubMed Central

    Buczkowski, Grzegorz; Richmond, Douglas S.

    2012-01-01

    Numerous studies have examined the effect of urbanization on species richness and most studies implicate urbanization as the major cause of biodiversity loss. However, no study has identified an explicit connection between urbanization and biodiversity loss as the impact of urbanization is typically inferred indirectly by comparing species diversity along urban-rural gradients at a single time point. A different approach is to focus on the temporal rather than the spatial aspect and perform “before and after” studies where species diversity is cataloged over time in the same sites. The current study examined changes in ant abundance and diversity associated with the conversion of natural habitats into urban habitats. Ant abundance and diversity were tracked in forested sites that became urbanized through construction and were examined at 3 time points - before, during, and after construction. On average, 4.3±1.2 unique species were detected in undisturbed plots prior to construction. Ant diversity decreased to 0.7±0.8 species in plots undergoing construction and 1.5±1.1 species in plots 1 year after construction was completed. With regard to species richness, urbanization resulted in the permanent loss of 17 of the 20 species initially present in the study plots. Recovery was slow and only 3 species were present right after construction was completed and 4 species were present 1 year after construction was completed. The second objective examined ant fauna recovery in developed residential lots based on time since construction, neighboring habitat quality, pesticide inputs, and the presence of invasive ants. Ant diversity was positively correlated with factors that promoted ecological recovery and negatively correlated with factors that promoted ecological degradation. Taken together, these results address a critical gap in our knowledge by characterizing the short- and long-term the effects of urbanization on the loss of ant biodiversity. PMID:22876291

  6. Changes in Streptococcus pyogenes causing invasive disease in Portugal: evidence for superantigen gene loss and acquisition.

    PubMed

    Friães, Ana; Lopes, Joana P; Melo-Cristino, José; Ramirez, Mario

    2013-12-01

    The emergence of highly virulent and successful Streptococcus pyogenes (group A streptococci - GAS) clones has been attributed to the exchange of virulence factors by lateral gene transfer mechanisms, which strongly contribute to genomic diversity. We characterized a collection of 191 GAS isolates recovered from normally sterile sites in Portugal during 2006-2009 and compared them to invasive isolates obtained during 2000-2005. Antimicrobial resistance rates did not change significantly between the two periods and were generally low. In 2006-2009, emm1, emm89, emm3, and emm6 represented 60% of the isolates. The chromosomally encoded superantigen (SAg) genes speG and smeZ were present in the majority (>90%) of the isolates, while speJ was found in only 45%. The phage encoded SAgs varied greatly in prevalence (2-53%). The distribution of emm types, pulsed-field gel electrophoresis profiling (PFGE) clusters, and SAg profiles changed significantly between the periods, although there were no statistically supported changes in the prevalence of individual types. While the macrolide susceptible clone emm1-T1-ST28 remained dominant (28%), there was a significant decrease in clonal diversity as indicated by both PFGE profiling and emm typing. This was accompanied by intra-clonal divergence of SAg profiles, which was statistically confirmed for isolates representing emm1, emm28, and emm44. This diversification was associated with the loss and acquisition of SAg genes, carried by phages and of chromosomal origin. These data suggest an ongoing genomic diversification of GAS invasive isolates in Portugal that may contribute to the persistence of clones with improved fitness or virulence. PMID:23932912

  7. Serotype/serogroup-specific antibiotic non-susceptibility of invasive and non-invasive Streptococcus pneumoniae, Switzerland, 2004 to 2014.

    PubMed

    Hauser, Christoph; Kronenberg, Andreas; Allemann, Aurélie; Mühlemann, Kathrin; Hilty, Markus

    2016-05-26

    Concurrent analysis of antibiotic resistance of colonising and invasive Streptococcus pneumoniae gives a more accurate picture than looking at either of them separately. Therefore, we analysed 2,129 non-invasive and 10,996 invasive pneumococcal isolates from Switzerland from 2004 to 2014, which spans the time before and after the introduction of the heptavalent (PCV7) and 13-valent (PCV13) conjugated pneumococcal polysaccharide vaccines. Serotype/serogroup information was linked with all antibiotic resistance profiles. During the study period, the proportion of non-susceptible non-invasive and invasive isolates significantly decreased for penicillin, ceftriaxone, erythromycin and trimethoprim/sulfamethoxazole (TMP-SMX). This was most apparent in non-invasive isolates from study subjects younger than five years (penicillin (p = 0.006), erythromycin (p = 0.01) and TMP-SMX (p = 0.002)). Resistant serotypes/serogroups included in PCV7 and/or PCV13 decreased and were replaced by non-PCV13 serotypes (6C and 15B/C). Serotype/serogroup-specific antibiotic resistance rates were comparable between invasive and non-invasive isolates. Adjusted odds ratios of serotype/serogroup-specific penicillin resistance were significantly higher in the west of Switzerland for serotype 6B (1.8; 95% confidence interval (CI): 1.4-4.8), 9V (3.4; 95% CI: 2.0-5.7), 14 (5.3; 95% CI: 3.8-7.5), 19A (2.2; 95% CI: 1.6-3.1) and 19F (3.1; 95% CI: 2.1-4.6), probably due to variations in the antibiotic consumption. PMID:27254535

  8. Primary invasive extramammary Paget disease on penoscrotum: a clinicopathological analysis of 41 cases.

    PubMed

    Shu, Bo; Shen, Xu-Xia; Chen, Peng; Fang, Xin-Zhi; Guo, Yong-Lian; Kong, Yun-Yi

    2016-01-01

    To investigate the clinicopathological and immunohistochemical features and prognostic factors for invasive extramammary Paget disease (EMPD) on penoscrotum, we described the clinical presentations, histopathology, and follow-up courses of 41 cases. The age of the patients ranged from 42 to 84 years. All the patients were treated with wide surgical excision, and 14 were confirmed to have lymph node metastasis. During follow-up, 18 patients (43.9%) developed local or distant recurrence, and 13 patients (31.7%) died of the disease. Histologically, glandular formation with true lumina within the epidermis was found in 29 cases, and signet ring cells were seen in 11 cases. In invasive components, nodular/micronodular growth pattern, glandular formation, and strands/solid sheets existed in 95.1% (39/41), 43.9% (18/41), and 24.4% (10/41) of the cases, respectively. More than half of the cases had at least 2 different types of invasive growth pattern. CK7 was diffusely positive in all cases, whereas CK20 was focally positive in 8 cases. GCDFP-15 was expressed to a variable degree in 24 cases. Presence of strands/solid sheets, lymphovascular invasion, and perineural invasion in invasive EMPD were found to be correlated with higher lymph node metastatic rate. Univariate analysis revealed that patients with one of the following prognostic factors: delay in diagnosis more than 7.5 years, depth of invasion more than 1 mm, invasive pattern of strands/solid sheets, marked inflammation, lymphovascular invasion, and lymph node metastasis at diagnosis, had significantly shorter cancer-specific survival. We concluded that invasive EMPD is a rare malignant skin neoplasm with morphological diversity. Invasive pattern of strands/solid sheets is significantly associated with both lymph node metastasis and worse prognosis. Delay in diagnosis, depth of invasion, marked inflammation, lymphovascular invasion, and regional lymph node status are important prognostic factors. PMID:26508372

  9. Integrated assessment of biological invasions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    As the main annalists of the ecological and economic impacts of invasions on ecosystems around the world, ecologists should be able to provide information that can guide management practices. Managers often want to know about the potential for invasion of specific organisms in the sites under their ...

  10. Prioritizing invasive plant management strategies

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Invasive plants are seriously impacting rangelands by displacing desirable species. Management of these species is expensive and careful allocation of scarce dollars is necessary. Ecologically-based invasive plant management (EBIPM) has the potential to provide an improved decision-making process ...

  11. Managing the invasive species risk

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Florida, California and Hawaii are on the front lines when it comes to the war with invasive species. One study documented the Florida invasion at more than one new arthropod species becoming established in the state each month with California estimated to be one every other month. This does not mea...

  12. MEDUSAHEAD INVASION, IMPLICATIONS, AND MANAGEMENT.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Medusahead invasion of western rangelands is at a cross-road, either an aggressive effort to prevent its invasion of new areas is initiated, or millions of acres will be lost. Medusahead is an aggressive, exotic, annual grass invading rangelands in the western United States. The rapid spread of me...

  13. Managing the invasive species risk

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Florida, California and Hawaii are on the front lines when it comes to the war with invasive species. One study documented the Florida invasion at more than one new arthropod species becoming established in the state each month with California estimated to be one every other month. This does not me...

  14. [Minimally invasive breast surgery].

    PubMed

    Mátrai, Zoltán; Gulyás, Gusztáv; Kunos, Csaba; Sávolt, Akos; Farkas, Emil; Szollár, András; Kásler, Miklós

    2014-02-01

    Due to the development in medical science and industrial technology, minimally invasive procedures have appeared in the surgery of benign and malignant breast diseases. In general , such interventions result in significantly reduced breast and chest wall scars, shorter hospitalization and less pain, but they require specific, expensive devices, longer surgical time compared to open surgery. Furthermore, indications or oncological safety have not been established yet. It is quite likely, that minimally invasive surgical procedures with high-tech devices - similar to other surgical subspecialties -, will gradually become popular and it may form part of routine breast surgery even. Vacuum-assisted core biopsy with a therapeutic indication is suitable for the removal of benign fibroadenomas leaving behind an almost invisible scar, while endoscopically assisted skin-sparing and nipple-sparing mastectomy, axillary staging and reconstruction with latissimus dorsi muscle flap are all feasible through the same short axillary incision. Endoscopic techniques are also suitable for the diagnostics and treatment of intracapsular complications of implant-based breast reconstructions (intracapsular fluid, implant rupture, capsular contracture) and for the biopsy of intracapsular lesions with uncertain pathology. Perception of the role of radiofrequency ablation of breast tumors requires further hands-on experience, but it is likely that it can serve as a replacement of surgical removal in a portion of primary tumors in the future due to the development in functional imaging and anticancer drugs. With the reduction of the price of ductoscopes routine examination of the ductal branch system, guided microdochectomy and targeted surgical removal of terminal ducto-lobular units or a "sick lobe" as an anatomical unit may become feasible. The paper presents the experience of the authors and provides a literature review, for the first time in Hungarian language on the subject. Orv. Hetil

  15. Physiology of non-invasive respiratory support.

    PubMed

    Alexiou, Stamatia; Panitch, Howard B

    2016-06-01

    Non-invasive ventilation (NIV) is used in neonates to treat extrathoracic and intrathoracic airway obstruction, parenchymal lung disease and disorders of control of breathing. Avoidance of airway intubation is associated with a reduction in the incidence of chronic lung disease among preterm infants with respiratory distress syndrome. Use of nasal continuous positive airway pressure (nCPAP) may help establish and maintain functional residual capacity (FRC), decrease respiratory work, and improve gas exchange. Other modes of non-invasive ventilation, which include heated humidified high-flow nasal cannula therapy (HHHFNC), nasal intermittent mandatory ventilation (NIMV), non-invasive pressure support ventilation (NI-PSV), and bi-level CPAP (SiPAP™), have also been shown to provide additional benefit in improving breathing patterns, reducing work of breathing, and increasing gas exchange when compared with nCPAP. Newer modes, such as neurally adjusted ventilatory assist (NAVA), hold the promise of improving patient-ventilator synchrony and so might ultimately improve outcomes for preterm infants with respiratory distress. PMID:26923501

  16. Src Kinase Regulation in Progressively Invasive Cancer

    PubMed Central

    Xu, Weichen; Allbritton, Nancy; Lawrence, David S.

    2012-01-01

    Metastatic progression is a multistep process that involves tumor growth and survival, motility and invasion, and subsequent proliferation in an inappropriate environment. The Src protein tyrosine kinase has been implicated in many of the biochemical pathways that drive these behaviors. Although Src itself is only rarely mutated in human tumors, its aberrant activity has been noted in various cancers and suggested to serve as a barometer of metastatic potential. With these features in mind, we examined Src kinase regulation at the structural, enzymatic, and expression levels as a function of progressively invasive prostate cancer cell lines. Surprisingly, both total Src content and kinase activity decrease with increasing cell line aggressiveness, an observation that appears to be inconsistent with the well-documented role of Src in the signaling pathways that drive growth and invasion. However, we do observe a direct correlation between Src kinase specific activity (total Src kinase activity/total Src content) and metastatic aggressiveness, possibly suggesting that in highly aggressive cell lines, key signaling enzymes are globally recruited to drive the cancerous phenotype. In addition, although the expected enhanced phosphorylation of Src at Tyr-416 (activation site) is present in the most aggressive prostate cancer cell lines, unexpectedly high phosphorylation levels at the Tyr-527 inhibitory site are observed as well. The latter, rather than representative of inhibited enzyme, is more indicative of primed Src responsive to local phosphorylated binding partners. PMID:23145001

  17. Inhibition between invasives: a newly introduced predator moderates the impacts of a previously established invasive predator.

    PubMed

    Griffen, Blaine D; Guy, Travis; Buck, Julia C

    2008-01-01

    1. With continued globalization, species are being transported and introduced into novel habitats at an accelerating rate. Interactions between invasive species may provide important mechanisms that moderate their impacts on native species. 2. The European green crab Carcinus maenas is an aggressive predator that was introduced to the east coast of North America in the mid-1800 s and is capable of rapid consumption of bivalve prey. A newer invasive predator, the Asian shore crab Hemigrapsus sanguineus, was first discovered on the Atlantic coast in the 1980s, and now inhabits many of the same regions as C. maenas within the Gulf of Maine. Using a series of field and laboratory investigations, we examined the consequences of interactions between these predators. 3. Density patterns of these two species at different spatial scales are consistent with negative interactions. As a result of these interactions, C. maenas alters its diet to consume fewer mussels, its preferred prey, in the presence of H. sanguineus. Decreased mussel consumption in turn leads to lower growth rates for C. maenas, with potential detrimental effects on C. maenas populations. 4. Rather than an invasional meltdown, this study demonstrates that, within the Gulf of Maine, this new invasive predator can moderate the impacts of the older invasive predator. PMID:18177327

  18. Lymphatic endothelial cells actively regulate prostate cancer cell invasion.

    PubMed

    Shah, Tariq; Wildes, Flonne; Kakkad, Samata; Artemov, Dmitri; Bhujwalla, Zaver M

    2016-07-01

    Lymphatic vessels serve as the primary route for metastatic spread to lymph nodes. However, it is not clear how interactions between cancer cells and lymphatic endothelial cells (LECs), especially within hypoxic microenvironments, affect the invasion of cancer cells. Here, using an MR compatible cell perfusion assay, we investigated the role of LEC-prostate cancer (PCa) cell interaction in the invasion and degradation of the extracellular matrix (ECM) by two human PCa cell lines, PC-3 and DU-145, under normoxia and hypoxia, and determined the metabolic changes that occurred under these conditions. We observed a significant increase in the invasion of ECM by invasive PC-3 cells, but not poorly invasive DU-145 cells when human dermal lymphatic microvascular endothelial cells (HMVEC-dlys) were present. Enhanced degradation of ECM by PC-3 cells in the presence of HMVEC-dlys identified interactions between HMVEC-dlys and PCa cells influencing cancer cell invasion. The enhanced ECM degradation was partly attributed to increased MMP-9 enzymatic activity in PC-3 cells when HMVEC-dlys were in close proximity. Significantly higher uPAR and MMP-9 expression levels observed in PC-3 cells compared to DU-145 cells may be one mechanism for increased invasion and degradation of matrigel by these cells irrespective of the presence of HMVEC-dlys. Hypoxia significantly decreased invasion by PC-3 cells, but this decrease was significantly attenuated when HMVEC-dlys were present. Significantly higher phosphocholine was observed in invasive PC-3 cells, while higher glycerophosphocholine was observed in DU-145 cells. These metabolites were not altered in the presence of HMVEC-dlys. Significantly increased lipid levels and lipid droplets were observed in PC-3 and DU-145 cells under hypoxia reflecting an adaptive survival response to oxidative stress. These results suggest that in vivo, invasive cells in or near lymphatic endothelial cells are likely to be more invasive and degrade the ECM

  19. Nestin depletion induces melanoma matrix metalloproteinases and invasion

    PubMed Central

    Lee, Chung-Wei; Zhan, Qian; Lezcano, Cecilia; Frank, Markus H.; Huang, John; Larson, Allison; Lin, Jennifer Y.; Wan, Marilyn T.; Lin, Ping-I; Ma, Jie; Kleffel, Sonja; Schatton, Tobias; Lian, Christine G.; Murphy, George F.

    2015-01-01

    Matrix metalloproteinases (MMPs) are key biological mediators of processes as diverse as wound healing, embryogenesis, and cancer progression. Although MMPs may be induced through multiple signaling pathways, the precise mechanisms for their regulation in cancer are incompletely understood. Because cytoskeletal changes are known to accompany MMP expression, we sought to examine the potential role of the poorly understood cytoskeletal protein, nestin, in modulating melanoma MMPs. Nestin knockdown (KD) upregulated expression of specific MMPs and MMP-dependent invasion both through extracellular matrix barriers in vitro and in peritumoral connective tissue of xenografts in vivo. Development of 3-dimensionsal melanospheres that in vitro partially recapitulate non-invasive tumorigenic melanoma growth was inhibited by nestin KD, although ECM invasion by aberrant melanospheres that did form was enhanced. Mechanistically, nestin KD-dependent melanoma invasion was associated with intracellular redistribution of phosphorylated focal adhesion kinase (pFAK) and increased melanoma cell responsiveness to transforming growth factor-beta (TGF-β), both implicated in pathways of melanoma invasion. The results suggest that the heretofore poorly understood intermediate filament, nestin, may serve as a novel mediator of MMPs critical to melanoma virulence. PMID:25365206

  20. An ideal weed: plasticity and invasiveness in Polygonum cespitosum.

    PubMed

    Sultan, Sonia E; Matesanz, Silvia

    2015-12-01

    The introduced Asian plant Polygonum cespitosum has only recently become invasive in northeastern North America, spreading into sunny as well as shaded habitats. We present findings from a multiyear case study of this ongoing species invasion, drawing on field environmental measurements, glasshouse plasticity and resurrection experiments, and molecular genetic (microsatellite) data. We focus in particular on patterns of individual phenotypic plasticity (norms of reaction), their diversity within and among populations in the species' introduced range, and their contribution to its potential to evolve even greater invasiveness. Genotypes from introduced-range P. cespitosum populations have recently evolved to express greater adaptive plasticity to full sun and/or dry conditions without any loss of fitness in shade. Evidently, this species may evolve the sort of "general-purpose genotypes" hypothesized by Herbert Baker to characterize an "ideal weed." Indeed, we identified certain genotypes capable of extremely high reproductive output across contrasting conditions, including sunny, shaded, moist, and dry. Populations containing these high-performance genotypes had consistently higher fitness in all glasshouse habitats; there was no evidence for local adaptive differentiation among populations from sunny, shaded, moist, or dry sites. Norm of reaction data may provide valuable insights to invasion biology: the presence of broadly adaptive, high-performance genotypes can promote a species' ecological spread while providing the fuel for increased invasiveness to evolve. PMID:26457473

  1. Detrimental Influence of Invasive Earthworms on North American Cold-Temperate Forest Soils

    ERIC Educational Resources Information Center

    Enerson, Isabel

    2012-01-01

    The topic of invasive earthworms is a timely concern that goes against many preconceived notions regarding the positive benefits of all worms. In the cold-temperate forests of North America invasive worms are threatening forest ecosystems, due to the changes they create in the soil, including decreases in C:N ratios and leaf litter, disruption of…

  2. Emergence and accumulation of novel pathogens suppress an invasive species.

    PubMed

    Stricker, Kerry Bohl; Harmon, Philip F; Goss, Erica M; Clay, Keith; Luke Flory, S

    2016-04-01

    Emerging pathogens are a growing threat to human health, agriculture and the diversity of ecological communities but may also help control problematic species. Here we investigated the diversity, distribution and consequences of emerging fungal pathogens infecting an aggressive invasive grass that is rapidly colonising habitats throughout the eastern USA. We document the recent emergence and accumulation over time of diverse pathogens that are members of a single fungal genus and represent multiple, recently described or undescribed species. We also show that experimental suppression of these pathogens increased host performance in the field, demonstrating the negative effects of emerging pathogens on invasive plants. Our results suggest that invasive species can facilitate pathogen emergence and amplification, raising concerns about movement of pathogens among agricultural, horticultural, and wild grasses. However, one possible benefit of pathogen accumulation is suppression of aggressive invaders over the long term, potentially abating their negative impacts on native communities. PMID:26931647

  3. Plant polyphenolics as anti-invasive cancer agents.

    PubMed

    Bracke, M E; Vanhoecke, B W A; Derycke, L; Bolca, S; Possemiers, S; Heyerick, A; Stevens, C V; De Keukeleire, D; Depypere, H T; Verstraete, W; Williams, C A; McKenna, S T; Tomar, S; Sharma, D; Prasad, A K; DePass, A L; Parmar, V S

    2008-02-01

    Because invasion is, either directly or via metastasis formation, the main cause of death in cancer patients, development of efficient anti-invasive agents is an important research challenge. We have established a screening program for potentially anti-invasive compounds. The assay is based on organotypic confronting cultures between human invasive cancer cells and a fragment of normal tissue in three dimensions. Anti-invasive agents appeared to be heterogeneous with regard to their chemical nature, but plant alkaloids, polyphenolics and some of their synthetic congeners were well represented. Even within this group, active compounds were quite diverse: (+)-catechin, tangeretin, xanthohumol and other prenylated chalcones, 3,7-dimethoxyflavone, a pyrazole derivative, an isoxazolylcoumarin and a prenylated desoxybenzoin. The data gathered in this system are now applied in two projects. Firstly, structure-activity relationships are explored with computer models using an artificial neural network approach, based on quantitative structural descriptors. The aim of this study is the prediction and design of optimally efficient anti-invasive compounds. Secondly, the metabolism of orally ingested plant polyphenolics by colonic bacteria is studied in a simulator of the human intestinal microbial ecosystem (SHIME) and in human intervention trials. This method should provide information on the final bioavailability of the active compounds in the human body, with regard to microbial metabolism, and the feasibility of designing pre- or probiotics that increase the generation of active principles for absorption in the gastro-intestinal tract. The final and global aim of all these studies is to predict, synthesize and apply in vivo molecules with an optimal anti-invasive, and hence an anti-metastatic activity against cancer. PMID:18288920

  4. Calbindins decreased after space flight

    NASA Technical Reports Server (NTRS)

    Sergeev, I. N.; Rhoten, W. B.; Carney, M. D.

    1996-01-01

    Exposure of the body to microgravity during space flight causes a series of well-documented changes in Ca2+ metabolism, yet the cellular and molecular mechanisms leading to these changes are poorly understood. Calbindins, vitamin D-dependent Ca2+ binding proteins, are believed to have a significant role in maintaining cellular Ca2+ homeostasis. In this study, we used biochemical and immunocytochemical approaches to analyze the expression of calbindin-D28k and calbindin-D9k in kidneys, small intestine, and pancreas of rats flown for 9 d aboard the space shuttle. The effects of microgravity on calbindins in rats from space were compared with synchronous Animal Enclosure Module controls, modeled weightlessness animals (tail suspension), and their controls. Exposure to microgravity resulted in a significant and sustained decrease in calbindin-D28k content in the kidney and calbindin-D9k in the small intestine of flight animals, as measured by enzyme-linked immunosorbent assay (ELISA). Modeled weightlessness animals exhibited a similar decrease in calbindins by ELISA. Immunocytochemistry (ICC) in combination with quantitative computer image analysis was used to measure in situ the expression of calbindins in the kidney and the small intestine, and the expression of insulin in pancreas. There was a large decrease of immunoreactivity in renal distal tubular cell-associated calbindin-D28k and in intestinal absorptive cell-associated calbindin-D9k of space flight and modeled weightlessness animals compared with matched controls. No consistent difference in pancreatic insulin immunoreactivity between space flight, modeled weightlessness, and controls was observed. Regression analysis of results obtained by quantitative ICC and ELISA for space flight, modeled weightlessness animals, and their controls demonstrated a significant correlation. These findings after a short-term exposure to microgravity or modeled weightlessness suggest that a decreased expression of calbindins

  5. Teaching for Diversity.

    ERIC Educational Resources Information Center

    Garcia, Ricardo L.

    This book focuses on how to teach students from diverse cultures and how to teach students to live in a diverse society. Chapter 1, "Democracy, Diversity, and Universal Education," discusses "The Nature of a Free Society,""The Role of Universal Education," and "Schools as Communities." Chapter 2, "Identifying and Understanding Diversity Issues,"…

  6. 10 Diversity Champions II

    ERIC Educational Resources Information Center

    Nealy, Michelle J.; Pluviose, David; Roach, Ronald

    2008-01-01

    Introducing the "Champions of Diversity" in the Academic Kickoff issue proved a timely reminder of the mission of Diverse during the lead up to the 25th anniversary of Cox, Matthews and Associates, the founder of the former Black Issues in Higher Education and publisher of Diverse. In this edition, the editors at Diverse unveil its second slate of…

  7. 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

  8. 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

  9. Plant functional traits of dominant native and invasive species in mediterranean-climate ecosystems.

    PubMed

    Funk, Jennifer L; Standish, Rachel J; Stock, William D; Valladares, Fernando

    2016-01-01

    The idea that dominant invasive plant species outperform neighboring native species through higher rates of carbon assimilation and growth is supported by several analyses of global data sets. However, theory suggests that native and invasive species occurring in low-resource environments will be functionally similar, as environmental factors restrict the range of observed physiological and morphological trait values. We measured resource-use traits in native and invasive plant species across eight diverse vegetation communities distributed throughout the five mediterranean-climate regions, which are drought prone and increasingly threatened by human activities, including the introduction of exotic species. Traits differed strongly across the five regions. In regions with functional differences between native and invasive species groups, invasive species displayed traits consistent with high resource acquisition; however, these patterns were largely attributable to differences in life form. We found that species invading mediterranean-climate regions were more likely to be annual than perennial: three of the five regions were dominated by native woody species and invasive annuals. These results suggest that trait differences between native and invasive species are context dependent and will vary across vegetation communities. Native and invasive species within annual and perennial groups had similar patterns of carbon assimilation and resource use, which contradicts the widespread idea that invasive species optimize resource acquisition rather than resource conservation. . PMID:27008777

  10. INVASIVE SPECIES RESEARCH IN THE USDA AGRICULTURAL RESEARCH SERVICE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Invasive pests cause huge losses to both agricultural production systems and to the natural environment through displacing native species and decreasing biodiversity. It is now estimated that many thousand exotic insects, weeds and pathogens have been established in the United States and that these...

  11. Invasive species compendium: Salvinia molesta D.S. Mitchell

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Salvinia molesta D.S. Mitchell is an invasive aquatic fern native to a small area of south-eastern Brazil. It has spread throughout the world, forming thick mats of vegetation that decrease dissolved oxygen and pH while outcompeting native vegetation. It has been introduced and established into many...

  12. Historical Invasion Records Can Be Misleading: Genetic Evidence for Multiple Introductions of Invasive Raccoons (Procyon lotor) in Germany.

    PubMed

    Fischer, Mari L; Hochkirch, Axel; Heddergott, Mike; Schulze, Christoph; Anheyer-Behmenburg, Helena E; Lang, Johannes; Michler, Frank-Uwe; Hohmann, Ulf; Ansorge, Hermann; Hoffmann, Lothar; Klein, Roland; Frantz, Alain C

    2015-01-01

    Biological invasions provide excellent study systems to understand evolutionary, genetic and ecological processes during range expansions. There is strong evidence for positive effects of high propagule pressure and the associated higher genetic diversity on invasion success, but some species have become invasive despite small founder numbers. The raccoon (Procyon lotor) is often considered as a typical example for such a successful invasion resulting from a small number of founders. The species' largest non-native population in Germany is commonly assumed to stem from a small number of founders and two separate founding events in the 1930s and 1940s. In the present study we analyzed 407 raccoons at 20 microsatellite loci sampled from the invasive range in Western Europe to test if these assumptions are correct. Contrary to the expectations, different genetic clustering methods detected evidence for at least four independent introduction events that gave rise to genetically differentiated subpopulations. Further smaller clusters were either artifacts or resulted from founder events at the range margin and recent release of captive individuals. We also found genetic evidence for on-going introductions of individuals. Furthermore a novel randomization process was used to determine the potential range of founder population size that would suffice to capture all the alleles present in a cluster. Our results falsify the assumption that this species has become widespread and abundant despite being genetically depauperate and show that historical records of species introductions may be misleading. PMID:25946257

  13. Historical Invasion Records Can Be Misleading: Genetic Evidence for Multiple Introductions of Invasive Raccoons (Procyon lotor) in Germany

    PubMed Central

    Fischer, Mari L.; Hochkirch, Axel; Heddergott, Mike; Schulze, Christoph; Anheyer-Behmenburg, Helena E.; Lang, Johannes; Michler, Frank-Uwe; Hohmann, Ulf; Ansorge, Hermann; Hoffmann, Lothar; Klein, Roland; Frantz, Alain C.

    2015-01-01

    Biological invasions provide excellent study systems to understand evolutionary, genetic and ecological processes during range expansions. There is strong evidence for positive effects of high propagule pressure and the associated higher genetic diversity on invasion success, but some species have become invasive despite small founder numbers. The raccoon (Procyon lotor) is often considered as a typical example for such a successful invasion resulting from a small number of founders. The species’ largest non-native population in Germany is commonly assumed to stem from a small number of founders and two separate founding events in the 1930s and 1940s. In the present study we analyzed 407 raccoons at 20 microsatellite loci sampled from the invasive range in Western Europe to test if these assumptions are correct. Contrary to the expectations, different genetic clustering methods detected evidence for at least four independent introduction events that gave rise to genetically differentiated subpopulations. Further smaller clusters were either artifacts or resulted from founder events at the range margin and recent release of captive individuals. We also found genetic evidence for on-going introductions of individuals. Furthermore a novel randomization process was used to determine the potential range of founder population size that would suffice to capture all the alleles present in a cluster. Our results falsify the assumption that this species has become widespread and abundant despite being genetically depauperate and show that historical records of species introductions may be misleading. PMID:25946257

  14. Geographic Proximity Not a Prerequisite for Invasion: Hawaii Not the Source of California Invasion by Light Brown Apple Moth (Epiphyas postvittana)

    PubMed Central

    Rubinoff, Daniel; Holland, Brenden S.; San Jose, Michael; Powell, Jerry A.

    2011-01-01

    Background The light brown apple moth (LBAM), Epiphyas postvittana (Walker), is native to Australia but invaded England, New Zealand, and Hawaii more than 100 years ago. In temperate climates, LBAM can be a major agricultural pest. In 2006 LBAM was discovered in California, instigating eradication efforts and quarantine against Hawaiian agriculture, the assumption being that Hawaii was the source of the California infestation. Genetic relationships among populations in Hawaii, California, and New Zealand are crucial to understanding LBAM invasion dynamics across the Pacific. Methodology/Principal Findings We sequenced mitochondrial DNA (mtDNA) from 1293 LBAM individuals from California (695), Hawaii (448), New Zealand (147), and Australia (3) to examine haplotype diversity and structure among introduced populations, and evaluate the null hypothesis that invasive populations are from a single panmictic source. However, invasive populations in California and New Zealand harbor deep genetic diversity, whereas Hawaii shows low level, shallow diversity. Conclusions/Significance LBAM recently has established itself in California, but was in Hawaii and New Zealand for hundreds of generations, yet California and New Zealand show similar levels of genetic diversity relative to Hawaii. Thus, there is no clear relationship between duration of invasion and genetic structure. Demographic statistics suggest rapid expansion occurring in California and past expansions in New Zealand; multiple introductions of diverse, genetically fragmented lineages could contribute to these patterns. Hawaii and California share no haplotypes, therefore, Hawaii is not the source of the California introduction. Paradoxically, Hawaii and California share multiple haplotypes with New Zealand. New Zealand may be the source for the California and Hawaii infestations, but the introductions were independent, and Hawaii was invaded only once. This has significant implications for quarantine, and suggests

  15. Minimally Invasive Surgery plus rt-PA for Intracerebral Hemorrhage Evacuation (MISTIE) Decreases Perihematomal Edema

    PubMed Central

    Mould, W. Andrew; Carhuapoma, J. Ricardo; Muschelli, John; Lane, Karen; Morgan, Timothy C; McBee, Nichol A; Bistran-Hall, Amanda J; Ullman, Natalie L; Vespa, Paul; Martin, Neil A; Awad, Issam; Zuccarello, Mario; Hanley, Daniel F.

    2014-01-01

    Background and Purpose Perihematomal edema (PHE) can worsen outcomes following ICH. Reports suggest that blood degradation products lead to PHE. We hypothesized that hematoma evacuation will reduce PHE volume and that treatment with rt-PA will not exacerbate it. Methods MISTIE II tested safety and efficacy of hematoma evacuation after ICH. We conducted a semi-automated, computerized volumetric analysis on CT to assess impact of hematoma removal on PHE and 2) effects of rt-PA on PHE. Volumetric analyses were performed on Baseline Stability (BLS) and End of Treatment (EOT) scans. Results Seventy-nine surgical and 39 medical patients from MISTIE II were analyzed. Mean hematoma volume at EOT was 19.6±14.5 cc for the surgical cohort and 40.7±13.9 cc for the medical cohort (p<0.001). Edema volume at EOT was lower for the surgical cohort: 27.7±13.3 cc than medical cohort: 41.7±14.6 cc (p<0.001). Graded effect of clot removal on PHE was observed when patients with >65%, 20-65%, and <20% ICH removed were analyzed (p<0.001). Positive correlation between PHE reduction and percent of ICH removed was identified (ρ=0.658; p<0.001). In the surgical cohort, 69 patients underwent surgical aspiration and rt-PA (S+rt-PA) while 10 underwent surgical aspiration only (SO). Both cohorts achieved similar clot reduction: S+rt-PA, 18.9±14.5 cc; and SO, 24.5±14.0 cc (p=0.26). Edema at EOT in S+rt-PA was 28.1±13.8 cc and 24.4±8.6 cc in SO (p=0.41). Conclusions Hematoma evacuation is associated with significant reduction in PHE. Furthermore, PHE does not appear to be exacerbated by rt-PA, making such neurotoxic effects unlikely when the drug is delivered to intracranial clot. Clinical Trial Registration Information URL: http://clinicaltrials.gov/ct2/show/NCT00224770?term=MISTIE&rank=1 Clinicaltrials.gov ID: NCT00224770 PMID:23391763

  16. Trophic network architecture of root-associated bacterial communities determines pathogen invasion and plant health

    PubMed Central

    Wei, Zhong; Yang, Tianjie; Friman, Ville-Petri; Xu, Yangchun; Shen, Qirong; Jousset, Alexandre

    2015-01-01

    Host-associated bacterial communities can function as an important line of defence against pathogens in animals and plants. Empirical evidence and theoretical predictions suggest that species-rich communities are more resistant to pathogen invasions. Yet, the underlying mechanisms are unclear. Here, we experimentally test how the underlying resource competition networks of resident bacterial communities affect invasion resistance to the plant pathogen Ralstonia solanacearum in microcosms and in tomato plant rhizosphere. We find that bipartite resource competition networks are better predictors of invasion resistance compared with resident community diversity. Specifically, communities with a combination of stabilizing configurations (low nestedness and high connectance), and a clear niche overlap with the pathogen, reduce pathogen invasion success, constrain pathogen growth within invaded communities and have lower levels of diseased plants in greenhouse experiments. Bacterial resource competition network characteristics can thus be important in explaining positive diversity–invasion resistance relationships in bacterial rhizosphere communities. PMID:26400552

  17. Transwell(®) invasion assays.

    PubMed

    Marshall, John

    2011-01-01

    The need to identify inhibitors of cancer invasion has driven the development of quantitative in vitro invasion assays. The most common assays used are based on the original Boyden assay system. Today commercially available plastic inserts for multi-well plates, which possess a cell-permeable membrane, as typified by Transwell(®) Permeable Supports, permit accurate repeatable invasion assays. When placed in the well of a multi-well tissue culture plate these inserts create a two-chamber system separated by the cell-permeable membrane. To create an invasion assay the pores in the membrane are blocked with a gel composed of extracellular matrix that is meant to mimic the typical matrices that tumour cells encounter during the invasion process in vivo. By placing the cells on one side of the gel and a chemoattractant on the other side of the gel, invasion is determined by counting those cells that have traversed the cell-permeable membrane having invaded towards the higher concentration of chemoattractant. In this chapter, in addition to protocols for performing Transwell invasion assays, there is consideration of the limitations of current assay designs with regard to available matrices and the absence of tumour microenvironment cells. PMID:21748672

  18. 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

  19. Decreasing Fires in Mediterranean Europe

    PubMed Central

    Turco, Marco; Bedia, Joaquín; Di Liberto, Fabrizio; Fiorucci, Paolo; von Hardenberg, Jost; Koutsias, Nikos; Llasat, Maria-Carmen; Xystrakis, Fotios; Provenzale, Antonello

    2016-01-01

    Forest fires are a serious environmental hazard in southern Europe. Quantitative assessment of recent trends in fire statistics is important for assessing the possible shifts induced by climate and other environmental/socioeconomic changes in this area. Here we analyse recent fire trends in Portugal, Spain, southern France, Italy and Greece, building on a homogenized fire database integrating official fire statistics provided by several national/EU agencies. During the period 1985-2011, the total annual burned area (BA) displayed a general decreasing trend, with the exception of Portugal, where a heterogeneous signal was found. Considering all countries globally, we found that BA decreased by about 3020 km2 over the 27-year-long study period (i.e. about -66% of the mean historical value). These results are consistent with those obtained on longer time scales when data were available, also yielding predominantly negative trends in Spain and France (1974-2011) and a mixed trend in Portugal (1980-2011). Similar overall results were found for the annual number of fires (NF), which globally decreased by about 12600 in the study period (about -59%), except for Spain where, excluding the provinces along the Mediterranean coast, an upward trend was found for the longer period. We argue that the negative trends can be explained, at least in part, by an increased effort in fire management and prevention after the big fires of the 1980’s, while positive trends may be related to recent socioeconomic transformations leading to more hazardous landscape configurations, as well as to the observed warming of recent decades. We stress the importance of fire data homogenization prior to analysis, in order to alleviate spurious effects associated with non-stationarities in the data due to temporal variations in fire detection efforts. PMID:26982584

  20. Decreasing Fires in Mediterranean Europe.

    PubMed

    Turco, Marco; Bedia, Joaquín; Di Liberto, Fabrizio; Fiorucci, Paolo; von Hardenberg, Jost; Koutsias, Nikos; Llasat, Maria-Carmen; Xystrakis, Fotios; Provenzale, Antonello

    2016-01-01

    Forest fires are a serious environmental hazard in southern Europe. Quantitative assessment of recent trends in fire statistics is important for assessing the possible shifts induced by climate and other environmental/socioeconomic changes in this area. Here we analyse recent fire trends in Portugal, Spain, southern France, Italy and Greece, building on a homogenized fire database integrating official fire statistics provided by several national/EU agencies. During the period 1985-2011, the total annual burned area (BA) displayed a general decreasing trend, with the exception of Portugal, where a heterogeneous signal was found. Considering all countries globally, we found that BA decreased by about 3020 km2 over the 27-year-long study period (i.e. about -66% of the mean historical value). These results are consistent with those obtained on longer time scales when data were available, also yielding predominantly negative trends in Spain and France (1974-2011) and a mixed trend in Portugal (1980-2011). Similar overall results were found for the annual number of fires (NF), which globally decreased by about 12600 in the study period (about -59%), except for Spain where, excluding the provinces along the Mediterranean coast, an upward trend was found for the longer period. We argue that the negative trends can be explained, at least in part, by an increased effort in fire management and prevention after the big fires of the 1980's, while positive trends may be related to recent socioeconomic transformations leading to more hazardous landscape configurations, as well as to the observed warming of recent decades. We stress the importance of fire data homogenization prior to analysis, in order to alleviate spurious effects associated with non-stationarities in the data due to temporal variations in fire detection efforts. PMID:26982584

  1. Bronchial hyperresponsiveness decreases through childhood.

    PubMed

    Riiser, Amund; Hovland, Vegard; Mowinckel, Petter; Carlsen, Kai-Håkon; Carlsen, Karin Lødrup

    2012-02-01

    Limited knowledge exists about development of bronchial hyperresponsiveness (BHR) through adolescence. We aimed to assess changes in and risk factors for BHR in adolescence. From a Norwegian birth cohort 517 subjects underwent clinical examinations, structured interviews and methacholine challenges at age 10 and 16. BHR was divided into four categories: no BHR (cumulative methacholine dose required to reduce FEV(1) by 20% (PD(20)) >16 μmol), borderline BHR (PD(20) ≤16 and >8 μmol), mild to moderate BHR (PD(20) ≤8 and >1 μmol), and severe BHR (PD(20) ≤ 1 μmol). Logistic regression analysis was used to assess risk factors and possible confounders. The number of children with PD(20) ≤ 8 decreased from 172 (33%) to 79 (15%) from age 10-16 (p < 0.001). Most children (n = 295, 57%) remained in the same BHR (category) from age 10-16 (50% with no BHR), whereas the majority 182 (82%) of the 222 children who changed BHR category, had decreased severity at age 16. PD(20) ≤ 8 at age 10 was the major risk factor for PD(20) ≤ 8 6 years later (odds ratio 6.3), without significant confounding effect (>25% change) of gender, active rhinitis, active asthma, height, FEV(1)/FVC, or allergic sensitization. BHR decreased overall in severity through adolescence, was stable for the majority of children and only a minority (8%) had increased BHR from age 10 to 16. Mild to moderate and severe BHR at age 10 were major risk factors for PD(20) ≤ 8 at 16 years and not modified by asthma or body size. PMID:22015380

  2. Non-invasive and invasive imaging of vulnerable coronary plaque.

    PubMed

    Celeng, Csilla; Takx, Richard A P; Ferencik, Maros; Maurovich-Horvat, Pál

    2016-08-01

    Vulnerable plaque is characterized by a large necrotic core and an overlying thin fibrous cap. Non-invasive imaging modalities such as computed tomography angiography (CTA) and magnetic resonance imaging (MRI) allow for the assessment of morphological plaque characteristics, while positron emission tomography (PET) enables the detection of metabolic activity within the atherosclerotic lesions. Invasive imaging modalities such as intravascular ultrasound (IVUS), optical-coherence tomography (OCT), and intravascular MRI (IV-MRI) display plaques at a high spatial resolution. Near-infrared spectroscopy (NIRS) allows for the detection of chemical components of atherosclerotic plaques. In this review, we describe state-of-the-art non-invasive and invasive imaging modalities and stress the combination of their advantages to identify vulnerable plaque features. PMID:27079893

  3. Monoamine oxidase A (MAO A) inhibitors decrease glioma progression

    PubMed Central

    Vaikari, Vijaya Pooja; Kota, Rajesh; Chen, Kevin; Yeh, Tzu-Shao; Jhaveri, Niyati; Groshen, Susan L.; Olenyuk, Bogdan Z.; Chen, Thomas C.; Hofman, Florence M.; Shih, Jean C.

    2016-01-01

    Glioblastoma (GBM) is an aggressive brain tumor which is currently treated with temozolomide (TMZ). Tumors usually become resistant to TMZ and recur; no effective therapy is then available. Monoamine Oxidase A (MAO A) oxidizes monoamine neurotransmitters resulting in reactive oxygen species which cause cancer. This study shows that MAO A expression is increased in human glioma tissues and cell lines. MAO A inhibitors, clorgyline or the near-infrared-dye MHI-148 conjugated to clorgyline (NMI), were cytotoxic for glioma and decreased invasion in vitro. Using the intracranial TMZ-resistant glioma model, clorgyline or NMI alone or in combination with low-dose TMZ reduced tumor growth and increased animal survival. NMI was localized specifically to the tumor. Immunocytochemistry studies showed that the MAO A inhibitor reduced proliferation, microvessel density and invasion, and increased macrophage infiltration. In conclusion, we have identified MAO A inhibitors as potential novel stand-alone drugs or as combination therapy with low dose TMZ for drug-resistant gliomas. NMI can also be used as a non-invasive imaging tool. Thus has a dual function for both therapy and diagnosis. PMID:26871599

  4. Monoamine oxidase A (MAO A) inhibitors decrease glioma progression.

    PubMed

    Kushal, Swati; Wang, Weijun; Vaikari, Vijaya Pooja; Kota, Rajesh; Chen, Kevin; Yeh, Tzu-Shao; Jhaveri, Niyati; Groshen, Susan L; Olenyuk, Bogdan Z; Chen, Thomas C; Hofman, Florence M; Shih, Jean C

    2016-03-22

    Glioblastoma (GBM) is an aggressive brain tumor which is currently treated with temozolomide (TMZ). Tumors usually become resistant to TMZ and recur; no effective therapy is then available. Monoamine Oxidase A (MAO A) oxidizes monoamine neurotransmitters resulting in reactive oxygen species which cause cancer. This study shows that MAO A expression is increased in human glioma tissues and cell lines. MAO A inhibitors, clorgyline or the near-infrared-dye MHI-148 conjugated to clorgyline (NMI), were cytotoxic for glioma and decreased invasion in vitro. Using the intracranial TMZ-resistant glioma model, clorgyline or NMI alone or in combination with low-dose TMZ reduced tumor growth and increased animal survival. NMI was localized specifically to the tumor. Immunocytochemistry studies showed that the MAO A inhibitor reduced proliferation, microvessel density and invasion, and increased macrophage infiltration. In conclusion, we have identified MAO A inhibitors as potential novel stand-alone drugs or as combination therapy with low dose TMZ for drug-resistant gliomas. NMI can also be used as a non-invasive imaging tool. Thus has a dual function for both therapy and diagnosis. PMID:26871599

  5. Mechanisms of invasive population establishment and spread of pinewood nematodes in China.

    PubMed

    XIE, BingYan; CHENG, XinYue; SHI, Juan; ZHANG, QingWen; DAI, ShuMing; CHENG, Fei Xue; LUO, YouQing

    2009-06-01

    This paper summarizes the results of our study of the pinewood nematode (Bursaphelenchus xylophilus). By population genetic analysis, it was determined that there was no genetic bottle caused by the founder effect and genetic drift in the Chinese invasive population. Multiple invasions with large amounts of nematodes from different sources led to rich genetic diversity in the invasive population. Keeping high genetic diversity in the invasive process may be one of the genetic mechanisms in its successful invasion. By testing interspecies competition, it was shown that, with high fecundity and a strong competitive ability, B. xylophilus outcompeted the native species B. mucronatus in the natural ecosystem during the invasion process. Competitive displacement may be one of the ecological mechanisms of B. xylophilus's invasion. In addition, an unequal interspecific hybridization with introgress was in favor of the invasive species which also accelerated the replacement of B. mucronatus by B. xylophilus. The structures, functions and evolutions of a few important genes that are closely related to the ecological adaptation of pinewood nematodes were studied to explore the molecular mechanism of its ecological adaptations. Further, the resistance and resilience mechanism of the pine ecosystem invaded by pinewood nematodes was also investigated. The results of these studies uncovered a portion of the genetic and ecological mechanisms of PWN's successful invasion and laid a foundation for further study to obtain a comprehensive interpretation of the mechanisms of the nematode invasion. The results also provided a scientific basis for effectively controlling the occurrence and spread of pine wilt disease which is caused by nematodes. Various aspects requiring further investigation are considered. PMID:19557337

  6. [Genetic diversity of microsatellite loci in captive Amur tigers].

    PubMed

    Zhang, Yu-Gaung; Li, Di-Qiang; Xiao, Qi-Ming; Rao, Li-Qun; Zhang, Xue-Wen

    2004-09-01

    The tiger is one of the most threatened wildlife species since the abundance and distribution of tiger have decreased dramatically in the last century. The wild Amur tiger (Panthera tigris altaica) only distributed in northeast China, the far east area of Russia and the north Korea and its size of wild population is about 450 in the world and 20 in China. Several hundred captive populations of Amur tigers are the main source to protect gene library of tiger and the source of recovering the wild populations. The Breeding Center for Felidae at Hengdaohezi and Haoerbin Tiger Park in Heilongjiang Province is the biggest captive breeding base in China. How to make clear the genetic pedigree and establish reasonable breeding system is the urgent issues. So we use the microsatellite DNA markers and non-invasive technology to research on the genetic diversity of captive Amur tiger in this study. Ten microsatellite loci (Fca005, Fca075, Fca094, Fca152, Fca161, Fca294, Pti002, Pti003, Pti007 and Pti010), highly variable nuclear markers, were studied their genetic diversity in 113 captive Amur tigers. The PCR amplified products of microsatellite loci were detected by non-denatured polyacrylamide gel electrophoresis. Allele numbers, allelic frequency, gene heterozygosity(H(e)), polymorphism information content(PIC) and effective number of allele(N(e)) were calculated. 41 alleles were found and their size were ranged from 110bp to 250bp in ten microsatellite loci, Fca152 had 6 alleles, Fca075, Fca094 and Fca294 had 5 alleles, Fca005 and Pti002 had 4 alleles and the others had 3 alleles in all tiger samples, respectively. The allelic frequencies were from 0.009 to 0.767; The He ranged from 0.385 to 0.707, and Fca294 and Pti010 locus had the highest and lowest value; the PIC were from 0.353 to 0.658, Fca294 and Pti010 locus had the highest and lowest value; and N(e) were from 1.626 to 3.409, Fca294 and Pti010 locus had the highest and lowest value, which showed the ten

  7. Minimally Invasive Multivessel Coronary Surgery and Hybrid Coronary Revascularization: Can We Routinely Achieve Less Invasive Coronary Surgery?

    PubMed

    Rodriguez, Maria; Ruel, Marc

    2016-01-01

    Coronary artery bypass grafting (CABG) is the gold standard in managing severe coronary artery disease. However, it is associated with prolonged recovery and potential complications, in part due to the invasiveness of the procedure. Less invasive CABG techniques attempt to improve the quality and quantity of life in the same way as surgical revascularization but with fewer complications. Minimally invasive coronary surgery (MICS) through a small thoracotomy allows for complete revascularization with good results in graft patency. Perioperative mortality is low, and there is decreased need for blood transfusion, lower surgical site infection rates, and an earlier return to full physical function. Hybrid coronary revascularization (HCR) attempts to combine the advantages of coronary artery bypass grafting with those of percutaneous coronary intervention. Several studies have shown that HCR provides better short-term outcomes with regard to decreased ventilation and ICU time, reduced need for blood transfusion, and shortened hospital stay. However, the rates for major adverse cardiovascular events and mortality are comparable to conventional CABG, except for patients with a high SYNTAX score who displayed increased mortality rates. There is also strong evidence of a higher need for repeat revascularization with HCR compared to CABG. Overall, MICS and HCR appear to be viable alternatives to conventional CABG, offering a less invasive approach to coronary revascularization, which may be especially beneficial to high-risk patients. This article discusses approaches that deliver the advantages of minimally invasive surgical revascularization that can be adapted by surgeons with minimal investment with regards to training and infrastructure. PMID:27127557

  8. Diversity Statements: How Faculty Applicants Address Diversity

    ERIC Educational Resources Information Center

    Schmaling, Karen B.; Trevino, Amira Y.; Lind, Justin R.; Blume, Arthur W.; Baker, Dana L.

    2015-01-01

    The purpose of the present study was to examine application materials for assistant professor positions in 3 academic disciplines. Applicants were asked to write a diversity statement describing how they would advance diversity through their research, teaching, and service. The sample included application materials submitted by 191 candidates for…

  9. Capturing the Diversity in Lexical Diversity

    ERIC Educational Resources Information Center

    Jarvis, Scott

    2013-01-01

    The range, variety, or diversity of words found in learners' language use is believed to reflect the complexity of their vocabulary knowledge as well as the level of their language proficiency. Many indices of lexical diversity have been proposed, most of which involve statistical relationships between types and tokens, and which ultimately…

  10. Does Staff Diversity Imply Openness to Diversity?

    ERIC Educational Resources Information Center

    Lauring, Jakob; Selmer, Jan

    2013-01-01

    Purpose: Post-secondary educational organizations are currently some of the most diverse settings to be found. However, few educational studies have dealt with staff diversity and hardly any has looked outside the USA. The purpose of this paper is to present a study of members of international university departments in Denmark. The authors set out…

  11. Can we create ethnically diverse skeletal collection from donated bodies?

    PubMed

    Weiss, Elizabeth

    2015-01-01

    Understanding bone health is least invasively and most effectively done through studying skeletal remains that reflect the living populations who will benefit from the knowledge produced through research. Donated body collections that accurately represent modern populations are needed for osteological insights to be applied to clinical practices. However, even though the US is growing increasingly diverse, donated body collections still suffer from a lack of ethnic diversity. Most individuals who donate their whole-bodies after death are European-American. Reasons for a lack of ethnic diversity stem from past injustices and present religious norms. Increasing body donation among minorities in the US and abroad may be difficult. PMID:25775919

  12. [Decreasing incidence of stent thrombosis].

    PubMed

    Lemesle, G; Delhaye, C

    2011-12-01

    Stent thrombosis (ST) remains a major pitfall of stent implantation in contemporary percutaneous coronary intervention (PCI) leading to high rates of death and non-fatal myocardial infarction. Many predictors of ST have been reported worldwide but the strongest have to be highlighted regarding the catastrophic prognosis of such an event. Because platelet aggregation has a pivotal role in ST pathogenesis, the new antiplatelet regimens combining aspirin and P2Y12 receptor inhibitors have led to a remarkable decrease in the ST incidence, especially in the setting of acute coronary syndrome (ACS). In this article, our purpose is to review the evolution of ST incidence since first stent use in PCI. We will also overview the main predictors of ST focusing on ACS and clopidogrel low response. PMID:22054519

  13. Squamous cell carcinoma - invasive (image)

    MedlinePlus

    This irregular red nodule is an invasive squamous cell carcinoma (a form of skin cancer). Initial appearance, shown here, may be very similar to a noncancerous growth called a keratoacanthoma. Squamous cell cancers ...

  14. Squamous cell carcinoma - invasive (image)

    MedlinePlus

    ... invasive squamous cell carcinoma (a form of skin cancer). Initial appearance, shown here, may be very similar to a noncancerous growth called a keratoacanthoma. Squamous cell cancers can metastasize (spread) and should be removed surgically ...

  15. Minimally Invasive Aortic Valve Replacement

    MedlinePlus Videos and Cool Tools

    ... screen and open the door to informed medical care. Good afternoon and welcome to the Heart Institute ... be progressive and less invasive in how we care for our patients. 8 Here's one from one ...

  16. 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...

  17. Mitral valve surgery - minimally invasive

    MedlinePlus

    ... that does many of these procedures. Minimally invasive heart valve surgery has improved greatly in recent years. These ... WT, Mack MJ. Transcatheter cardiac valve interventions. Surg Clin North Am . 2009;89:951-66. ...

  18. Heart bypass surgery - minimally invasive

    MedlinePlus

    ... in 30-day outcomes in high-risk patients randomized to off-pump versus on-pump coronary bypass ... Thiele H, Neumann-Schniedewind P, Jacobs S, et al. Randomized comparison of minimally invasive direct coronary artery bypass ...

  19. Propagule pressure-invasibility relationships: testing the influence of soil fertility and disturbance with Lespedeza cuneata.

    PubMed

    Houseman, Gregory R; Foster, Bryan L; Brassil, Chad E

    2014-02-01

    Although invasion risk is expected to increase with propagule pressure (PP), it is unclear whether PP-invasibility relationships follow an asymptotic or some other non-linear form and whether such relationships vary with underlying environmental conditions. Using manipulations of PP, soil fertility and disturbance, we tested how each influence PP-invasibility relationships for Lespedeza cuneata in a Kansas grassland and use recruitment curve models to determine how safe sites may contribute to plant invasions. After three growing seasons, we found that the PP-invasibility relationships best fit an asymptotic model of invasion reflecting a combination of density-independent and density-dependent processes and that seeds were aggregated within the plant community despite efforts to uniformly sow seeds. Consistent with some models, community invasibility decreased with enhanced soil fertility or reduced levels of disturbance in response to changes in the fraction of safe sites. Our results illustrate that disturbance and soil fertility can be a useful organizing principle for predicting community invasibility, asymptotic models are a reasonable starting point for modeling invasion, and new modeling techniques—coupled with classic experimental approaches—can enhance our understanding of the invasion process. PMID:24078081

  20. Asian longhorned beetle complicates the relationship between taxonomic diversity and pest vulnerability in street tree assemblages

    EPA Science Inventory

    Urban foresters routinely emphasise the importance of taxonomic diversity to reduce the vulnerability of tree assemblages to invasive pests, but it is unclear to what extent diversity reduces vulnerability to polyphagous (i.e. generalist) pests. Drawing on field data from seven c...

  1. Minimally Invasive Spinal Surgery with Intraoperative Image-Guided Navigation

    PubMed Central

    Kim, Terrence T.; Johnson, J. Patrick; Pashman, Robert; Drazin, Doniel

    2016-01-01

    We present our perioperative minimally invasive spine surgery technique using intraoperative computed tomography image-guided navigation for the treatment of various lumbar spine pathologies. We present an illustrative case of a patient undergoing minimally invasive percutaneous posterior spinal fusion assisted by the O-arm system with navigation. We discuss the literature and the advantages of the technique over fluoroscopic imaging methods: lower occupational radiation exposure for operative room personnel, reduced need for postoperative imaging, and decreased revision rates. Most importantly, we demonstrate that use of intraoperative cone beam CT image-guided navigation has been reported to increase accuracy. PMID:27213152

  2. Minimally Invasive Spinal Surgery with Intraoperative Image-Guided Navigation.

    PubMed

    Kim, Terrence T; Johnson, J Patrick; Pashman, Robert; Drazin, Doniel

    2016-01-01

    We present our perioperative minimally invasive spine surgery technique using intraoperative computed tomography image-guided navigation for the treatment of various lumbar spine pathologies. We present an illustrative case of a patient undergoing minimally invasive percutaneous posterior spinal fusion assisted by the O-arm system with navigation. We discuss the literature and the advantages of the technique over fluoroscopic imaging methods: lower occupational radiation exposure for operative room personnel, reduced need for postoperative imaging, and decreased revision rates. Most importantly, we demonstrate that use of intraoperative cone beam CT image-guided navigation has been reported to increase accuracy. PMID:27213152

  3. All stressed out and nowhere to go: does evolvability limit adaptation in invasive species? An introduction to the symposium at the SSE/ASN/SSB meeting, June 2004.

    PubMed

    Gilchrist, George W; Lee, Carol Eunmi

    2007-02-01

    Introduced and invasive species are major threats native species and communities and, quite naturally, most scientists and managers think of them in terms of ecological problems. However, species introductions are also experiments in evolution, both for the alien species and for the community that they colonize. We focus here on the introduced species because these offer opportunities to study the properties that allow a species to succeed in a novel habitat and the constraints that limit range expansion. Moreover, an increasing body of evidence from diverse taxa suggests that the introduced species often undergo rapid and observable evolutionary change in their new habitat. Evolution requires genetic variation, which may be decreased or expanded during an invasion, and an evolutionary mechanism such as genetic drift or natural selection. In this volume, we seek to understand how natural selection produces adaptive evolution during invasions. Key questions include what is the role of biotic and abiotic stress in driving adaptation, and what is the source of genetic variation in introduced populations. PMID:16924404

  4. Phylogeographic insights into the invasion history and secondary spread of the signal crayfish in Japan.

    PubMed

    Usio, Nisikawa; Azuma, Noriko; Larson, Eric R; Abbott, Cathryn L; Olden, Julian D; Akanuma, Hiromi; Takamura, Kenzi; Takamura, Noriko

    2016-08-01

    Successful invasion by nonindigenous species is often attributed to high propagule pressure, yet some foreign species become widespread despite showing reduced genetic variation due to founder effects. The signal crayfish (Pacifastacus leniusculus) is one such example, where rapid spread across Japan in recent decades is believed to be the result of only three founding populations. To infer the history and explore the success of this remarkable crayfish invasion, we combined detailed phylogeographical and morphological analyses conducted in both the introduced and native ranges. We sequenced 16S mitochondrial DNA of signal crayfish from across the introduced range in Japan (537 samples, 20 sites) and the native range in western North America (700 samples, 50 sites). Because chela size is often related to aggressive behavior in crayfish, and hence, their invasion success, we also measured chela size of a subset of specimens in both introduced and native ranges. Genetic diversity of introduced signal crayfish populations was as high as that of the dominant phylogeographic group in the native range, suggesting high propagule pressure during invasion. More recently established crayfish populations in Japan that originated through secondary spread from one of the founding populations exhibit reduced genetic diversity relative to older populations, probably as a result of founder effects. However, these newer populations also show larger chela size, consistent with expectations of rapid adaptations or phenotypic responses during the invasion process. Introduced signal crayfish populations in Japan originate from multiple source populations from a wide geographic range in the native range of western North America. A combination of high genetic diversity, especially for older populations in the invasive range, and rapid adaptation to colonization, manifested as larger chela in recent invasions, likely contribute to invasion success of signal crayfish in Japan. PMID

  5. Common Ground for Managing Invasive Annual Grasses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Invasive annual grasses often reach their full biological potential in ecosystems of the western United States. This suggests that crucial ecosystem "checks and balances" are not functioning. In other words, invasion occurs because ecosystems have lost resistance to invasion, and invasive plants a...

  6. Does high biodiversity reduce the risk of Lyme disease invasion?

    PubMed Central

    2013-01-01

    Background It has been suggested that increasing biodiversity, specifically host diversity, reduces pathogen and parasite transmission amongst wildlife (causing a “dilution effect”), whereby transmission amongst efficient reservoir hosts, (e.g. Peromyscus spp. mice for the agent of Lyme disease Borrelia burgdorferi) is reduced by the presence of other less efficient host species. If so, then increasing biodiversity should inhibit pathogen and parasite invasion. Methods We investigated this hypothesis by studying invasion of B. burgdorferi and its tick vector Ixodes scapularis in 71 field sites in southeastern Canada. Indices of trapped rodent host diversity, and of biodiversity of the wider community, were investigated as variables explaining the numbers of I. scapularis collected and B. burgdorferi infection in these ticks. A wide range of alternative environmental explanatory variables were also considered. Results The observation of low I. scapularis abundance and low B. burgdorferi infection prevalence in sites where I. scapularis were detected was consistent with early-stage invasion of the vector. There were significant associations between the abundance of ticks and season, year of study and ambient temperature. Abundance of host-seeking larvae was significantly associated with deer density, and abundance of host-seeking larvae and nymphs were positively associated with litter layer depth. Larval host infestations were lower where the relative proportion of non-Peromyscus spp. was high. Infestations of hosts with nymphs were lower when host species richness was higher, but overall nymphal abundance increased with species richness because Peromyscus spp. mouse abundance and host species richness were positively correlated. Nymphal infestations of hosts were lower where tree species richness was higher. B. burgdorferi infection prevalence in ticks varied significantly with an index of rates of migratory bird-borne vector and pathogen invasion. Conclusions

  7. Teaching Culturally Diverse Students.

    ERIC Educational Resources Information Center

    Correa, Vivian; Tulbert, Beth

    1991-01-01

    Characteristics of culturally diverse students are discussed in terms of language, culture, and socioeconomic factors. Meeting the educational needs of culturally diverse students can involve interactive teaming of professionals; parent involvement; and providing appropriate services, assessment, curriculum, and instruction. (JDD)

  8. Ecosystem management: Controlling biological invasion in an Illinois nature preserve

    SciTech Connect

    Thelen, C.S.; Schulz, K.E.

    1995-12-01

    Understanding the nature and effects of human interaction with the landscape is an important aspect of environmental decisionmaking. Often, human action alters the composition and distribution of organisms. In the North American central Midwest, human occupation has decimated native woodlands, which endure as habitat islands in a highly fragmented natural landscape dominated by intensive agriculture and permeated by invasive exotic species. The alterations in the landscape have affected the structure and function of the few remaining intact forests by altering the environment experienced by tree and herb species. A frequent invader of forest understories throughout the central Midwest is Vinca minor, a horticultural groundcover, yet this species has not previously been studied as a woodland invader. We tested the hypothesis that native understory species were excluded from colonized areas, and that tree seedling growth was suppressed. Using study plots in Knobeloch Woods Nature Preserve, St. Clair County, Illinois, we measured the effect of Vinca colonization on understory composition and diversity, by comparing colonized and uncolonized plots. We also related understory characteristics to soil and canopy properties. Finally, to evaluate an ongoing program to control the invasion in the field, we tested the hypothesis that simultaneous cutting and herbicide treatment had increased the diversity of native understory species. We hope with this study to provide fact-based recommendations for management of midwestern nature preserves experiencing exotic plant invasions.

  9. Biology and invasive species in the western U.S

    USGS Publications Warehouse

    U.S. Geological Survey

    2005-01-01

    The diversity of environments that characterizes the West is responsible for the region's rich biological heritage. This ecological diversity also means that opportunities for invasive species are many, varied, and complex. Island ecosystems are notoriously vulnerable to invaders as demonstrated in Hawaii and West Coast offshore islands. Aquatic invaders impose high economic and environmental costs in systems as varied as San Francisco Bay and desert springs in the Great Basin. Although the West's arid and montane ecosystems may seem resistant to plant and animal invaders, we now know that ex-otic species have altered physical processes related to fire and hydrology in a manner favoring further expansion and persis-tence of invaders. Natural resource managers value analytical, mapping, and genetics tools developed by USGS scientists to monitor invasive species and help conserve biological systems. USGS biologists conduct research to assist land and water managers' efforts to control invasive species and restore natural systems. Throughout the West, the USGS carries out studies for early detection and rapid assessment of invaders. The following are some examples of how the USGS is making a difference in the western United States.

  10. 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

  11. Genetic Bottlenecks in Time and Space: Reconstructing Invasions from Contemporary and Historical Collections

    PubMed Central

    Dormontt, Eleanor E.; Gardner, Michael G.; Breed, Martin F.; Rodger, James G.; Prentis, Peter J.; Lowe, Andrew J.

    2014-01-01

    Herbarium accession data offer a useful historical botanical perspective and have been used to track the spread of plant invasions through time and space. Nevertheless, few studies have utilised this resource for genetic analysis to reconstruct a more complete picture of historical invasion dynamics, including the occurrence of separate introduction events. In this study, we combined nuclear and chloroplast microsatellite analyses of contemporary and historical collections of Senecio madagascariensis, a globally invasive weed first introduced to Australia c. 1918 from its native South Africa. Analysis of nuclear microsatellites, together with temporal spread data and simulations of herbarium voucher sampling, revealed distinct introductions to south-eastern Australia and mid-eastern Australia. Genetic diversity of the south-eastern invasive population was lower than in the native range, but higher than in the mid-eastern invasion. In the invasive range, despite its low resolution, our chloroplast microsatellite data revealed the occurrence of new haplotypes over time, probably as the result of subsequent introduction(s) to Australia from the native range during the latter half of the 20th century. Our work demonstrates how molecular studies of contemporary and historical field collections can be combined to reconstruct a more complete picture of the invasion history of introduced taxa. Further, our study indicates that a survey of contemporary samples only (as undertaken for the majority of invasive species studies) would be insufficient to identify potential source populations and occurrence of multiple introductions. PMID:25192006

  12. 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.

  13. Impacts of invasive nonnative plant species on the rare forest herb Scutellaria montana

    NASA Astrophysics Data System (ADS)

    Sikkema, Jordan J.; Boyd, Jennifer N.

    2015-11-01

    Invasive plant species and overabundant herbivore populations have the potential to significantly impact rare plant species given their increased risk for local extirpation and extinction. We used interacting invasive species removal and grazer exclusion treatments replicated across two locations in an occurrence of rare Scutellaria montana (large-flowered skullcap) in Chattanooga, Tennessee, USA, to assess: 1) competition by invasive Ligustrum sinense (Chinese privet) and Lonicera japonica (Japanese honeysuckle) and 2) the role of invasive species in mediating Oedocoilus virginianus (white-tailed deer) grazing of S. montana. Contrary to our hypothesis that invasive species presence would suppress S. montana directly via competition, S. montana individuals experienced a seasonal increase in stem height when invasive species were intact but not when invasive species were removed. Marginally significant results indicated that invasive species may afford S. montana protection from grazers, and we suggest that invasive species also could protect S. montana from smaller herbivores and/or positively influence abiotic conditions. In contrast to growth responses, S. montana individuals protected from O. virginianus exhibited a decrease in flowering between seasons relative to unprotected plants, but invasive species did not affect this variable. Although it has been suggested that invasive plant species may negatively influence S. montana growth and fecundity, our findings do not support related concerns. As such, we suggest that invasive species eradication efforts in S. montana habitat could be more detrimental than positive due to associated disturbance. However, the low level of invasion of our study site may not be representative of potential interference in more heavily infested habitat.

  14. Prompt effect of replacing the 7-valent pneumococcal conjugate vaccine with the 13-valent vaccine on the epidemiology of invasive pneumococcal disease in Norway.

    PubMed

    Steens, Anneke; Bergsaker, Marianne A Riise; Aaberge, Ingeborg S; Rønning, Karin; Vestrheim, Didrik F

    2013-12-16

    The introduction of the 7-valent pneumococcal conjugate vaccine (PCV7) in the childhood immunisation programme in Norway in 2006 substantially decreased the incidence of vaccine-type (VT) invasive pneumococcal disease (IPD) in all age groups. Additionally, a slight increase in the non-vaccine (NVT) serotype IPD incidence (serotype replacement) was observed. After replacing PCV7 with PCV13 in 2011, a further decrease in IPD incidence is expected. However, the protection by the six additional serotypes opens new nasopharyngeal niches for colonisation, which favours conditions for serotype replacement. Close monitoring of IPD therefore remains important in order to quickly detect changes. In this observational retrospective population-based cohort study we used data notified nationally between 1 January 2004 and 31 December 2012 to determine the VT- and NVT-IPD incidences. The diversity in serotype distribution per year was analysed using the Simpson's index of diversity. Immunisation history of young children was obtained from the Norwegian Vaccination Registry to determine vaccine failure. The incidence of VT-IPD decreased in the targeted (<5 years) and non-targeted (≥5) age groups since PCV7 introduction and further decreased after the replacement with PCV13. Only two cases of vaccine failure were identified. This indicates very high effectiveness of the 2+1 schedules with PCV7 or PCV13 and suggests that non-vaccinated individuals profit through indirect protection. The decrease in incidence of PCV7-IPD in non-targeted age groups became larger in later years, indicating a lag phase for the indirect effects, and suggests that the indirect protection of PCV13 will increase in coming years. The incidence of some NVT, specifically serotypes 23B and 15A, increased after PCV13 introduction. This coincided with an increased Simpson's index of diversity in the targeted age group. As this suggests that serotype replacement is again occurring, continues monitoring of IPD

  15. Recent divergences and size decreases of eastern gorilla populations.

    PubMed

    Roy, Justin; Arandjelovic, Mimi; Bradley, Brenda J; Guschanski, Katerina; Stephens, Colleen R; Bucknell, Dan; Cirhuza, Henry; Kusamba, Chifundera; Kyungu, Jean Claude; Smith, Vince; Robbins, Martha M; Vigilant, Linda

    2014-11-01

    Compared with other African apes, eastern gorillas (Gorilla beringei) have been little studied genetically. We used analysis of autosomal DNA genotypes obtained from non-invasively collected faecal samples to estimate the evolutionary histories of the two extant mountain gorilla populations and the closely related eastern lowland gorillas. Our results suggest that eastern lowland gorillas and mountain gorillas split beginning some 10 000 years ago, followed 5000 years ago by the split of the two mountain gorilla populations of Bwindi Impenetrable National Park and the Virungas Massif. All three populations have decreased in effective population size, with particularly substantial 10-fold decreases for the mountain gorillas. These dynamics probably reflect responses to habitat changes resulting from climate fluctuations over the past 20 000 years as well as increasing human influence in this densely populated region in the last several thousand years. PMID:25376805

  16. Modeling Hawaiian ecosystem degradation due to invasive plants under current and future climates.

    PubMed

    Vorsino, Adam E; Fortini, Lucas B; Amidon, Fred A; Miller, Stephen E; Jacobi, James D; Price, Jonathan P; Gon, Sam 'ohukani'ohi'a; 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 <0.7 niche overlap (Warrens I) and relatively discriminative distributions (Area Under the Curve >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. PMID:24805254

  17. Modeling Hawaiian ecosystem degradation due to invasive plants under current and future climates.

    PubMed

    Vorsino, Adam E; Fortini, Lucas B; Amidon, Fred A; Miller, Stephen E; Jacobi, James D; Price, Jonathan P; 'Ohukani'ohi'a Gon, Sam; Koob, Gregory A

    2014-01-01

    Occupation of native ecosystems by invasive plant species alters their structure and/or function. In Hawaii, a subset of introduced plants is regarded as extremely harmful due to competitive ability, ecosystem modification, and biogeochemical habitat degradation. By controlling this subset of highly invasive ecosystem modifiers, conservation managers could significantly reduce native ecosystem degradation. To assess the invasibility of vulnerable native ecosystems, we selected a proxy subset of these invasive plants and developed robust ensemble species distribution models to define their respective potential distributions. The combinations of all species models using both binary and continuous habitat suitability projections resulted in estimates of species richness and diversity that were subsequently used to define an invasibility metric. The invasibility metric was defined from species distribution models with <0.7 niche overlap (Warrens I) and relatively discriminative distributions (Area Under the Curve >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. PMID:24991934

  18. Modeling Hawaiian Ecosystem Degradation due to Invasive Plants under Current and Future Climates

    PubMed Central

    Vorsino, Adam E.; Fortini, Lucas B.; Amidon, Fred A.; Miller, Stephen E.; Jacobi, James D.; Price, Jonathan P.; Gon, Sam 'Ohukani'ohi'a; 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 <0.7 niche overlap (Warrens I) and relatively discriminative distributions (Area Under the Curve >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. PMID:24805254

  19. Insights on Diversity.

    ERIC Educational Resources Information Center

    Bloom, Carol, Ed.; And Others

    This state-of-the-art report presents a series of essays on the topic of diversity. Essays include: (1) "Committing to Diversity" (George L. Mehaffy); (2) "Serving the Community by Serving Our Members" (Michael P. Wolfe); (3) "How Diversity Matters" (Asa G. Hilliard, III); (4) "A Prerequisite to Teaching Multiculturally" (Mary Louise Gomez); (5)…

  20. BioDiversity.

    ERIC Educational Resources Information Center

    Wilson, E. O., Ed.; Peter, Frances M., Ed.

    The diversity of life forms is one of the greatest wonders of the planet earth. The biosphere is an intricate tapestry of interwoven life forms. This book offers an overall view of this biological diversity and carries an urgent warning about the rapid alteration and destruction of the environments that have fostered the diversity of life forms…

  1. The State of Diversity.

    ERIC Educational Resources Information Center

    Josey, E. J.

    1994-01-01

    Examines what is being done to implement cultural diversity in libraries. Topics addressed include affirmative action; defining cultural diversity, including the significance of ethnicity, race, and race relations in the workplace; problems in implementing cultural diversity; and examples of successful implementation programs. (Contains three…

  2. Leadership and Diversity

    ERIC Educational Resources Information Center

    Coleman, Marianne

    2012-01-01

    As part of the special edition recognizing the 40th anniversary of "Educational Management Administration & Leadership" this article reviews the coverage of leadership and diversity issues in the journal. The majority of articles concerning diversity have focused on gender, with attention turning to the wider concept of diversity since the year…

  3. Thinking about Diversity.

    ERIC Educational Resources Information Center

    Anderson, James A.

    1993-01-01

    Before companies attempt to increase the diversity in their management ranks, it is necessary for them to learn to manage diversity. Managers should have a plan; focus on individual learning, human-relations, motivational, and communication styles; examine organizational culture; and offer diversity training. (JOW)

  4. Managing Generational Diversity

    ERIC Educational Resources Information Center

    O'Donovan, Eamonn

    2009-01-01

    Many school leaders have explored the issue of diversity when it comes to students, teachers and staff. Their focus typically has been on gender and ethnicity. However, generational diversity, an area of diversity that warrants serious consideration, has received less attention. Generational intelligence is important today for two reasons. First…

  5. Take action: influence diversity.

    PubMed

    Gomez, Norma J

    2013-01-01

    Increased diversity brings strength to nursing and ANNA. Being a more diverse association will require all of us working together. There is an old proverb that says: "one hand cannot cover the sky; it takes many hands." ANNA needs every one of its members to be a part of the diversity initiative. PMID:24579394

  6. Multilevel and Diverse Classrooms

    ERIC Educational Resources Information Center

    Baurain, Bradley, Ed.; Ha, Phan Le, Ed.

    2010-01-01

    The benefits and advantages of classroom practices incorporating unity-in-diversity and diversity-in-unity are what "Multilevel and Diverse Classrooms" is all about. Multilevel classrooms--also known as mixed-ability or heterogeneous classrooms--are a fact of life in ESOL programs around the world. These classrooms are often not only multilevel…

  7. Near term climate projections for invasive species distributions

    USGS Publications Warehouse

    Jarnevich, C.S.; Stohlgren, T.J.

    2009-01-01

    Climate change and invasive species pose important conservation issues separately, and should be examined together. We used existing long term climate datasets for the US to project potential climate change into the future at a finer spatial and temporal resolution than the climate change scenarios generally available. These fine scale projections, along with new species distribution modeling techniques to forecast the potential extent of invasive species, can provide useful information to aide conservation and invasive species management efforts. We created habitat suitability maps for Pueraria montana (kudzu) under current climatic conditions and potential average conditions up to 30 years in the future. We examined how the potential distribution of this species will be affected by changing climate, and the management implications associated with these changes. Our models indicated that P. montana may increase its distribution particularly in the Northeast with climate change and may decrease in other areas. ?? 2008 Springer Science+Business Media B.V.

  8. 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

  9. Human-aided admixture may fuel ecosystem transformation during biological invasions: theoretical and experimental evidence.

    PubMed

    Molofsky, Jane; Keller, Stephen R; Lavergne, Sébastien; Kaproth, Matthew A; Eppinga, Maarten B

    2014-04-01

    Biological invasions can transform our understanding of how the interplay of historical isolation and contemporary (human-aided) dispersal affects the structure of intraspecific diversity in functional traits, and in turn, how changes in functional traits affect other scales of biological organization such as communities and ecosystems. Because biological invasions frequently involve the admixture of previously isolated lineages as a result of human-aided dispersal, studies of invasive populations can reveal how admixture results in novel genotypes and shifts in functional trait variation within populations. Further, because invasive species can be ecosystem engineers within invaded ecosystems, admixture-induced shifts in the functional traits of invaders can affect the composition of native biodiversity and alter the flow of resources through the system. Thus, invasions represent promising yet under-investigated examples of how the effects of short-term evolutionary changes can cascade across biological scales of diversity. Here, we propose a conceptual framework that admixture between divergent source populations during biological invasions can reorganize the genetic variation underlying key functional traits, leading to shifts in the mean and variance of functional traits within invasive populations. Changes in the mean or variance of key traits can initiate new ecological feedback mechanisms that result in a critical transition from a native ecosystem to a novel invasive ecosystem. We illustrate the application of this framework with reference to a well-studied plant model system in invasion biology and show how a combination of quantitative genetic experiments, functional trait studies, whole ecosystem field studies and modeling can be used to explore the dynamics predicted to trigger these critical transitions. PMID:24772269

  10. Human-aided admixture may fuel ecosystem transformation during biological invasions: theoretical and experimental evidence

    PubMed Central

    Molofsky, Jane; Keller, Stephen R; Lavergne, Sébastien; Kaproth, Matthew A; Eppinga, Maarten B

    2014-01-01

    Biological invasions can transform our understanding of how the interplay of historical isolation and contemporary (human-aided) dispersal affects the structure of intraspecific diversity in functional traits, and in turn, how changes in functional traits affect other scales of biological organization such as communities and ecosystems. Because biological invasions frequently involve the admixture of previously isolated lineages as a result of human-aided dispersal, studies of invasive populations can reveal how admixture results in novel genotypes and shifts in functional trait variation within populations. Further, because invasive species can be ecosystem engineers within invaded ecosystems, admixture-induced shifts in the functional traits of invaders can affect the composition of native biodiversity and alter the flow of resources through the system. Thus, invasions represent promising yet under-investigated examples of how the effects of short-term evolutionary changes can cascade across biological scales of diversity. Here, we propose a conceptual framework that admixture between divergent source populations during biological invasions can reorganize the genetic variation underlying key functional traits, leading to shifts in the mean and variance of functional traits within invasive populations. Changes in the mean or variance of key traits can initiate new ecological feedback mechanisms that result in a critical transition from a native ecosystem to a novel invasive ecosystem. We illustrate the application of this framework with reference to a well-studied plant model system in invasion biology and show how a combination of quantitative genetic experiments, functional trait studies, whole ecosystem field studies and modeling can be used to explore the dynamics predicted to trigger these critical transitions. PMID:24772269

  11. Mechanisms underlying the impacts of exotic plant invasions.

    PubMed Central

    Levine, Jonathan M; Vilà, Montserrat; D'Antonio, Carla M; Dukes, Jeffrey S; Grigulis, Karl; Lavorel, Sandra

    2003-01-01

    Although the impacts of exotic plant invasions on community structure and ecosystem processes are well appreciated, the pathways or mechanisms that underlie these impacts are poorly understood. Better exploration of these processes is essential to understanding why exotic plants impact only certain systems, and why only some invaders have large impacts. Here, we review over 150 studies to evaluate the mechanisms underlying the impacts of exotic plant invasions on plant and animal community structure, nutrient cycling, hydrology and fire regimes. We find that, while numerous studies have examined the impacts of invasions on plant diversity and composition, less than 5% test whether these effects arise through competition, allelopathy, alteration of ecosystem variables or other processes. Nonetheless, competition was often hypothesized, and nearly all studies competing native and alien plants against each other found strong competitive effects of exotic species. In contrast to studies of the impacts on plant community structure and higher trophic levels, research examining impacts on nitrogen cycling, hydrology and fire regimes is generally highly mechanistic, often motivated by specific invader traits. We encourage future studies that link impacts on community structure to ecosystem processes, and relate the controls over invasibility to the controls over impact. PMID:12737654

  12. The thioredoxin system in breast cancer cell invasion and migration

    PubMed Central

    Bhatia, Maneet; McGrath, Kelly L.; Di Trapani, Giovanna; Charoentong, Pornpimol; Shah, Fenil; King, Mallory M.; Clarke, Frank M.; Tonissen, Kathryn F.

    2015-01-01

    Metastasis is the most life threatening aspect of breast cancer. It is a multi-step process involving invasion and migration of primary tumor cells with a subsequent colonization of these cells at a secondary location. The aim of the present study was to investigate the role of thioredoxin (Trx1) in the invasion and migration of breast cancer cells and to assess the strength of the association between high levels of Trx1 and thioredoxin reductase (TrxR1) expression with breast cancer patient survival. Our results indicate that the expression of both Trx1 and TrxR1 are statistically significantly increased in breast cancer patient cells compared with paired normal breast tissue from the same patient. Over-expression of Trx1 in MDA-MB-231 breast cancer cell lines enhanced cell invasion in in vitro assays while expression of a redox inactive mutant form of Trx1 (designated 1SS) or the antisense mRNA inhibited cell invasion. Addition of exogenous Trx1 also enhanced cell invasion, while addition of a specific monoclonal antibody that inhibits Trx1 redox function decreased cell invasion. Over-expression of intracellular Trx1 did not increase cell migration but expression of intracellular 1SS inhibited migration. Addition of exogenous Trx1 enhanced cell migration while 1SS had no effect. Treatment with auranofin inhibited TrxR activity, cell migration and clonogenic activity of MDA-MB-231 cells, while increasing reactive oxygen species (ROS) levels. Analysis of 25 independent cohorts with 5910 patients showed that Trx1 and TrxR1 were both associated with a poor patient prognosis in terms of overall survival, distant metastasis free survival and disease free survival. Therefore, targeting the Trx system with auranofin or other specific inhibitors may provide improved breast cancer patient outcomes through inhibition of cancer invasion and migration. PMID:26760912

  13. Invasive Infections with Nontyphoidal Salmonella in Sub-Saharan Africa.

    PubMed

    Mahon, Barbara E; Fields, Patricia I

    2016-06-01

    Invasive nontyphoidal Salmonella (NTS) infections in Africa cause an enormous burden of illness. These infections are often devastating, with mortality estimated at 20%, even with appropriate antimicrobial therapy. Two major groups-young children and HIV-infected adults-suffer the great majority of these infections. In children, younger age itself, as well as malaria, malnutrition, and HIV infection, are prominent risk factors. In adults, HIV infection is by far the most important risk factor. The most common serotypes in invasive infections are Salmonella enterica serotypes Typhimurium and Enteritidis. In recent years, a specific strain of Salmonella Typhimurium, multilocus sequence type 313, has caused epidemics of invasive disease. Little is known about risk factors for exposure to NTS, making the design of rational interventions to decrease exposure difficult. Antimicrobial therapy is critically important for treatment of invasive NTS infections. Thus, the emergence and spread of resistance to agents commonly used for treatment of invasive NTS infection, now including third-generation cephalosporins, is an ominous development. Already, many invasive NTS infections are essentially untreatable in many health care facilities in sub-Saharan Africa. Several candidate vaccines are in early development and, if safe and effective, could be promising. Interventions to prevent exposure to NTS (e.g., improved sanitation), to prevent the occurrence of disease if exposure does occur (e.g., vaccination, malaria control), and to prevent severe disease and death in those who become ill (e.g., preserving antimicrobial effectiveness) are all important in reducing the toll of invasive NTS disease in sub-Saharan Africa. PMID:27337467

  14. The thioredoxin system in breast cancer cell invasion and migration.

    PubMed

    Bhatia, Maneet; McGrath, Kelly L; Di Trapani, Giovanna; Charoentong, Pornpimol; Shah, Fenil; King, Mallory M; Clarke, Frank M; Tonissen, Kathryn F

    2016-08-01

    Metastasis is the most life threatening aspect of breast cancer. It is a multi-step process involving invasion and migration of primary tumor cells with a subsequent colonization of these cells at a secondary location. The aim of the present study was to investigate the role of thioredoxin (Trx1) in the invasion and migration of breast cancer cells and to assess the strength of the association between high levels of Trx1 and thioredoxin reductase (TrxR1) expression with breast cancer patient survival. Our results indicate that the expression of both Trx1 and TrxR1 are statistically significantly increased in breast cancer patient cells compared with paired normal breast tissue from the same patient. Over-expression of Trx1 in MDA-MB-231 breast cancer cell lines enhanced cell invasion in in vitro assays while expression of a redox inactive mutant form of Trx1 (designated 1SS) or the antisense mRNA inhibited cell invasion. Addition of exogenous Trx1 also enhanced cell invasion, while addition of a specific monoclonal antibody that inhibits Trx1 redox function decreased cell invasion. Over-expression of intracellular Trx1 did not increase cell migration but expression of intracellular 1SS inhibited migration. Addition of exogenous Trx1 enhanced cell migration while 1SS had no effect. Treatment with auranofin inhibited TrxR activity, cell migration and clonogenic activity of MDA-MB-231 cells, while increasing reactive oxygen species (ROS) levels. Analysis of 25 independent cohorts with 5910 patients showed that Trx1 and TrxR1 were both associated with a poor patient prognosis in terms of overall survival, distant metastasis free survival and disease free survival. Therefore, targeting the Trx system with auranofin or other specific inhibitors may provide improved breast cancer patient outcomes through inhibition of cancer invasion and migration. PMID:26760912

  15. Deletion of Invasion Protein B in Salmonella enterica Serovar Typhimurium Influences Bacterial Invasion and Virulence.

    PubMed

    Chen, Songbiao; Zhang, Chunjie; Liao, Chengshui; Li, Jing; Yu, Chuan; Cheng, Xiangchao; Yu, Zuhua; Zhang, Mingliang; Wang, Yang

    2015-12-01

    Salmonella enterica serovar Typhimurium (S. Typhimurium) has a wide host range and causes infections ranging from severe gastroenteritis to systemic infections in human, as well as causing typhoid-like disease in murine models of infection. S. Typhimurium translocates its effector proteins through the Salmonella pathogenicity island-I (SPI-I)-encoded T3SS-I needle complex. This study focuses on invasion protein B (SipB) of S. Typhimurium, which plays an active role in SPI-I invasion efficiency. To test our hypothesis, a sipB deletion mutant was constructed through double-crossover allelic using the suicide vector pRE112ΔsipB, and its biological characteristics were analyzed. The results showed that the SipB does not affect the growth of Salmonella, but the adherence, invasion, and virulence of the mutant were significantly decreased compared with wild-type S. Typhimurium (SL1344). This research indicates that SipB is an important virulence factor in the pathogenicity of S. Typhimurium. PMID:26341924

  16. Rapidly advancing invasive endomyocardial aspergillosis.

    PubMed

    Davutoglu, Vedat; Soydinc, Serdar; Aydin, Abdullah; Karakok, Metin

    2005-02-01

    The exposure to Aspergillus organisms/spores is likely common, but disease caused by tissue invasion with these fungi is uncommon and occurs primarily in the setting of immunosuppression. We report a case of rapidly advancing invasive endomyocardial aspergillosis secondary to prolonged usage of multiple broad-spectrum antibiotics in a nonimmunocompromised host. A 36-year-old cotton textile worker presented to our institution with a 3-month history of weight loss and fatigue. He reported receiving prolonged use of multiple broad-spectrum antibiotic treatment. The echocardiogram demonstrated multiple endomyocardial vegetations and a mass in the left atrium. Myocardial biopsy specimen revealed an invasive endomyocardial aspergillosis. The patient was investigated for immune deficiency including HIV, and this workup was negative. Treatment was started with amphotericin B and heparin for presumed left atrial thrombus. The patient died because of a rupture of mycotic aneurysm that resulted in cerebral hemorrhage. This case illustrates the risk of an invasive fungal infection in a nonimmunocompromised host who is a prolonged user of antibiotics in the setting of environmental exposure of opportunistic invasive fungal infections. PMID:15682058

  17. RNAi mediated Tiam1 gene knockdown inhibits invasion of retinoblastoma.

    PubMed

    Subramanian, Nithya; Navaneethakrishnan, Saranya; Biswas, Jyotirmay; Kanwar, Rupinder K; Kanwar, Jagat R; Krishnakumar, Subramanian

    2013-01-01

    T lymphoma invasion and metastasis protein (Tiam1) is up-regulated in variety of cancers and its expression level is related to metastatic potential of the type of cancer. Earlier, Tiam1 was shown to be overexpressed in retinoblastoma (RB) and we hypothesized that it was involved in invasiveness of RB. This was tested by silencing Tiam1 in RB cell lines (Y79 and Weri-Rb1) using siRNA pool, targeting different regions of Tiam1 mRNA. The cDNA microarray of Tiam1 silenced cells showed gene regulations altered by Tiam1 were predominantly on the actin cytoskeleton interacting proteins, apoptotic initiators and tumorogenic potential targets. The silenced phenotype resulted in decreased growth and increased apoptosis with non-invasive characteristics. Transfection of full length and N-terminal truncated construct (C1199) clearly revealed membrane localization of Tiam1 and not in the case of C580 construct. F-actin staining showed the interaction of Tiam1 with actin in the membrane edges that leads to ruffling, and also imparts varying invasive potential to the cell. The results obtained from our study show for the first time that Tiam1 modulates the cell invasion, mediated by actin cytoskeleton remodeling in RB. PMID:23950931

  18. Mechanisms driving diversity-productivity relationships differ between exotic and native communities and are affected by gastropod herbivory.

    PubMed

    Korell, Lotte; Schmidt, Robin; Bruelheide, Helge; Hensen, Isabell; Auge, Harald

    2016-04-01

    Biodiversity experiments have shown that productivity usually increases with plant species richness. However, most of those studies disregarded the importance of trophic interactions to the diversity-productivity relationship, and focused on the loss of native species while ignoring invasions by exotic species. Yet, as functional complementarity and the impact of plant antagonists are likely to differ between native and exotic communities, the diversity-productivity relationship may change when native communities are invaded by exotic species. We conducted a mesocosm experiment to test how diversity effects, evenness, and productivity differed between exotic and native assemblages of grassland plants, and how these communities were influenced by slug herbivory. In line with other experiments, we found higher productivity in exotic than in native communities. However, different mechanisms (complementarity vs. selection effect) contributed to the positive diversity-productivity relationships in exotic vs. native communities. Against expectations, native communities showed much lower evenness and a greater selection effect, suggesting that competitive dominance among native species may be even stronger than among exotic species. Slug herbivory decreased productivity independently of species origin and species diversity. However, exotic communities showed a threefold higher complementarity effect than native communities in the absence of slugs, which was mainly driven by differences in the responses of native and exotic legumes and nonleguminous herbs. Our results imply that underlying mechanisms for the positive diversity-productivity relationship differ between native and exotic communities in the early stages of community development, and that differential responses of plant functional groups to generalist herbivory can contribute to this pattern. PMID:26235964

  19. Changing trends of hemodynamic monitoring in ICU - from invasive to non-invasive methods: Are we there yet?

    PubMed

    Arora, Shubhangi; Singh, Preet Mohinder; Goudra, Basavana G; Sinha, Ashish C

    2014-04-01

    Hemodynamic monitoring in the form of invasive arterial, central venous pressure and pulmonary capillary wedge pressure monitoring may be required in seriously ill Intensive care unit patients, in patients undergoing surgeries involving gross hemodynamic changes and in patients undergoing cardiac surgeries. These techniques are considered the gold standards of hemodynamic monitoring but are associated with their inherent risks. A number of non-invasive techniques based on various physical principles are under investigation at present. The goal is to not only avoid the risk of invasive intervention, but also to match the gold standard set by them as far as possible. Techniques based on photoplethysmography, arterial tonometry and pulse transit time analysis have come up for continuous arterial pressure monitoring. Of these the first has been studied most extensively and validated, however it has been shown to be substandard in patients with gross hemodynamic instability. The other two still need further evaluation. While the non-invasive methods for arterial blood pressure monitoring are based on diverse technologies, those for measurement of central venous and pulmonary pressures are mostly based on imaging techniques such as echocardiography, Doppler ultrasound, computed tomography scan and chest X ray. Most of these techniques are based on measurement of the dimensions of the great veins. This makes them operator and observer dependent. However, studies done till now have revealed adequate inter-observer agreement. These techniques are still in their incipience and although initial studies are encouraging, further research is needed on this front. PMID:25024945

  20. Mechanisms Controlling the Plant Diversity Effect on Soil Microbial Community Composition and Soil Microbial Diversity

    NASA Astrophysics Data System (ADS)

    Mellado Vázquez, P. G.; Lange, M.; Griffiths, R.; Malik, A.; Ravenek, J.; Strecker, T.; Eisenhauer, N.; Gleixner, G.

    2015-12-01

    Soil microorganisms are the main drivers of soil organic matter cycling. Organic matter input by living plants is the major energy and matter source for soil microorganisms, higher organic matter inputs are found in highly diverse plant communities. It is therefore relevant to understand how plant diversity alters the soil microbial community and soil organic matter. In a general sense, microbial biomass and microbial diversity increase with increasing plant diversity, however the mechanisms driving these interactions are not fully explored. Working with soils from a long-term biodiversity experiment (The Jena Experiment), we investigated how changes in the soil microbial dynamics related to plant diversity were explained by biotic and abiotic factors. Microbial biomass quantification and differentiation of bacterial and fungal groups was done by phospholipid fatty acid (PLFA) analysis; terminal-restriction fragment length polymorphism was used to determine the bacterial diversity. Gram negative (G-) bacteria predominated in high plant diversity; Gram positive (G+) bacteria were more abundant in low plant diversity and saprotrophic fungi were independent from plant diversity. The separation between G- and G+ bacteria in relation to plant diversity was governed by a difference in carbon-input related factors (e.g. root biomass and soil moisture) between plant diversity levels. Moreover, the bacterial diversity increased with plant diversity and the evenness of the PLFA markers decreased. Our results showed that higher plant diversity favors carbon-input related factors and this in turn favors the development of microbial communities specialized in utilizing new carbon inputs (i.e. G- bacteria), which are contributing to the export of new C from plants to soils.

  1. Plant Functional Diversity and Species Diversity in the Mongolian Steppe

    PubMed Central

    Liu, Guofang; Xie, Xiufang; Ye, Duo; Ye, Xuehua; Tuvshintogtokh, Indree; Mandakh, Bayart; Huang, Zhenying; Dong, Ming

    2013-01-01

    Background The Mongolian steppe is one of the most important grasslands in the world but suffers from aridization and damage from anthropogenic activities. Understanding structure and function of this community is important for the ecological conservation, but has seldom been investigated. Methodology/Principal Findings In this study, a total of 324 quadrats located on the three main types of Mongolian steppes were surveyed. Early-season perennial forbs (37% of total importance value), late-season annual forbs (33%) and late-season perennial forbs (44%) were dominant in meadow, typical and desert steppes, respectively. Species richness, diversity and plant functional type (PFT) richness decreased from the meadow, via typical to desert steppes, but evenness increased; PFT diversity in the desert and meadow steppes was higher than that in typical steppe. However, above-ground net primary productivity (ANPP) was far lower in desert steppe than in the other two steppes. In addition, the slope of the relationship between species richness and PFT richness increased from the meadow, via typical to desert steppes. Similarly, with an increase in species diversity, PFT diversity increased more quickly in both the desert and typical steppes than that in meadow steppe. Random resampling suggested that this coordination was partly due to a sampling effect of diversity. Conclusions/Significance These results indicate that desert steppe should be strictly protected because of its limited functional redundancy, which its ecological functioning is sensitive to species loss. In contrast, despite high potential forage production shared by the meadow and typical steppes, management of these two types of steppes should be different: meadow steppe should be preserved due to its higher conservation value characterized by more species redundancy and higher spatial heterogeneity, while typical steppe could be utilized moderately because its dominant grass genus Stipa is resistant to

  2. Novel clones of Streptococcus pneumoniae causing invasive disease in Malaysia.

    PubMed

    Jefferies, Johanna M; Mohd Yusof, Mohd Yasim; Devi Sekaran, Shamala; Clarke, Stuart C

    2014-01-01

    Although Streptococcus pneumoniae is a leading cause of childhood disease in South East Asia, little has previously been reported regarding the epidemiology of invasive pneumococcal disease in Malaysia and very few studies have explored pneumococcal epidemiology using multilocus sequence typing (MLST). Here we describe serotype, multilocus sequence type (ST), and penicillin susceptibility of thirty pneumococcal invasive disease isolates received by the University of Malaya Medical Centre between February 2000 and January 2007 and relate this to the serotypes included in current pneumococcal conjugate vaccines. A high level of diversity was observed; fourteen serotypes and 26 sequence types (ST), (11 of which were not previously described) were detected from 30 isolates. Penicillin non-susceptible pneumococci accounted for 33% of isolates. The extent of molecular heterogeneity within carried and disease-causing Malaysian pneumococci remains unknown. Larger surveillance and epidemiological studies are now required in this region to provide robust evidence on which to base future vaccine policy. PMID:24941079

  3. Diagnosis of invasive fungal infections in immunocompromised children.

    PubMed

    Dornbusch, H J; Groll, A; Walsh, T J

    2010-09-01

    Early recognition and rapid initiation of effective treatment is a prerequisite for successful management of children with invasive fungal infections. The increasing diversity of fungal pathogens in high-risk patients, the differences in the antifungal spectra of available agents and the increasing rates of resistance call for identification of the infecting isolate at the species level and for information on drug resistance, in order to provide state-of-the-art patient care. Microscopy and culture of appropriate specimens remain the reference standard for mycological diagnosis, despite difficulties in obtaining appropriate and/or sufficient specimens, long durations of culture and false-negative results. Modern imaging studies and detection of circulating fungal cell wall components and DNA in blood and other body fluids or in affected tissues may improve the laboratory diagnosis of invasive mycoses. PMID:20678175

  4. Invasion Biology of Aedes japonicus japonicus (Diptera: Culicidae)

    PubMed Central

    Fonseca, Dina M.

    2014-01-01

    Aedes japonicus japonicus (Theobald) (Diptera: Culicidae) has recently expanded beyond its native range of Japan and Korea into large parts of North America and Central Europe. Population genetic studies begun immediately after the species was detected in North America revealed genetically distinct introductions that subsequently merged, likely contributing to the successful expansion. Interactions, particularly in the larval stage, with other known disease vectors give this invasive subspecies the potential to influence local disease dynamics. Its successful invasion likely does not involve superior direct competitive abilities, but it is associated with the use of diverse larval habitats and a cold tolerance that allows an expanded seasonal activity range in temperate climates. We predict a continued but slower expansion of Ae. j. japonicus in North America and a continued rapid expansion into other areas as this mosquito will eventually be considered a permanent resident of much of North America, Europe, Asia, and parts of Hawaii. PMID:24397520

  5. Invasion Dynamics of a Fish-Free Landscape by Brown Trout (Salmo trutta)

    PubMed Central

    Labonne, Jacques; Vignon, Matthias; Prévost, Etienne; Lecomte, Frédéric; Dodson, Julian J.; Kaeuffer, Renaud; Aymes, Jean-Christophe; Jarry, Marc; Gaudin, Philippe; Davaine, Patrick; Beall, Edward

    2013-01-01

    Metapopulation dynamics over the course of an invasion are usually difficult to grasp because they require large and reliable data collection, often unavailable. The invasion of the fish-free freshwater ecosystems of the remote sub-Antarctic Kerguelen Islands following man-made introductions of brown trout (Salmo trutta) in the 1950's is an exception to this rule. Benefiting from a full long term environmental research monitoring of the invasion, we built a Bayesian dynamic metapopulation model to analyze the invasion dynamics of 85 river systems over 51 years. The model accounted for patch size (river length and connections to lakes), alternative dispersal pathways between rivers, temporal trends in dynamics, and uncertainty in colonization date. The results show that the model correctly represents the observed pattern of invasion, especially if we assume a coastal dispersal pathway between patches. Landscape attributes such as patch size influenced the colonization function, but had no effect on propagule pressure. Independently from patch size and distance between patches, propagule pressure and colonization function were not constant through time. Propagule pressure increased over the course of colonization, whereas the colonization function decreased, conditional on propagule pressure. The resulting pattern of this antagonistic interplay is an initial rapid invasion phase followed by a strong decrease in the invasion rate. These temporal trends may be due to either adaptive processes or environmental gradients encountered along the colonization front. It was not possible to distinguish these two hypotheses. Because invasibility of Kerguelen Is. freshwater ecosystems is very high due to the lack of a pre-existing fish fauna and minimal human interference, our estimates of invasion dynamics represent a blueprint for the potential of brown trout invasiveness in pristine environments. Our conclusions shed light on the future of polar regions where, because of

  6. Invasiveness does not predict impact: response of native land snail communities to plant invasions in riparian habitats.

    PubMed

    Horáčková, Jitka; Juřičková, Lucie; Šizling, Arnošt L; Jarošík, Vojtěch; Pyšek, Petr

    2014-01-01

    Studies of plant invasions rarely address impacts on molluscs. By comparing pairs of invaded and corresponding uninvaded plots in 96 sites in floodplain forests, we examined effects of four invasive alien plants (Impatiens glandulifera, Fallopia japonica, F. sachalinensis, and F.× bohemica) in the Czech Republic on communities of land snails. The richness and abundance of living land snail species were recorded separately for all species, rare species listed on the national Red List, and small species with shell size below 5 mm. The significant impacts ranged from 16-48% reduction in snail species numbers, and 29-90% reduction in abundance. Small species were especially prone to reduction in species richness by all four invasive plant taxa. Rare snails were also negatively impacted by all plant invaders, both in terms of species richness or abundance. Overall, the impacts on snails were invader-specific, differing among plant taxa. The strong effect of I. glandulifera could be related to the post-invasion decrease in abundance of tall nitrophilous native plant species that are a nutrient-rich food source for snails in riparian habitats. Fallopia sachalinensis had the strongest negative impact of the three knotweeds, which reflects differences in their canopy structure, microhabitat humidity and litter decomposition. The ranking of Fallopia taxa according to the strength of impacts on snail communities differs from ranking by their invasiveness, known from previous studies. This indicates that invasiveness does not simply translate to impacts of invasion and needs to be borne in mind by conservation and management authorities. PMID:25238059

  7. Invasiveness Does Not Predict Impact: Response of Native Land Snail Communities to Plant Invasions in Riparian Habitats

    PubMed Central

    Horáčková, Jitka; Juřičková, Lucie; Šizling, Arnošt L.; Pyšek, Petr

    2014-01-01

    Studies of plant invasions rarely address impacts on molluscs. By comparing pairs of invaded and corresponding uninvaded plots in 96 sites in floodplain forests, we examined effects of four invasive alien plants (Impatiens glandulifera, Fallopia japonica, F. sachalinensis, and F.×bohemica) in the Czech Republic on communities of land snails. The richness and abundance of living land snail species were recorded separately for all species, rare species listed on the national Red List, and small species with shell size below 5 mm. The significant impacts ranged from 16–48% reduction in snail species numbers, and 29–90% reduction in abundance. Small species were especially prone to reduction in species richness by all four invasive plant taxa. Rare snails were also negatively impacted by all plant invaders, both in terms of species richness or abundance. Overall, the impacts on snails were invader-specific, differing among plant taxa. The strong effect of I. glandulifera could be related to the post-invasion decrease in abundance of tall nitrophilous native plant species that are a nutrient-rich food source for snails in riparian habitats. Fallopia sachalinensis had the strongest negative impact of the three knotweeds, which reflects differences in their canopy structure, microhabitat humidity and litter decomposition. The ranking of Fallopia taxa according to the strength of impacts on snail communities differs from ranking by their invasiveness, known from previous studies. This indicates that invasiveness does not simply translate to impacts of invasion and needs to be borne in mind by conservation and management authorities. PMID:25238059

  8. Antioxidant glucosylated caffeoylquinic acid derivatives in the invasive tropical soda apple, Solanum viarum

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The eggplant (Solanum melongena) and other species within the “spiny solanums” (Solanum subgenus Leptostemonum) contain diverse and abundant antioxidant caffeoylquinic acid (CQA) derivatives. The fruit of an aggressive invasive species in the spiny solanums, Solanum viarum, contain numerous CQA deri...

  9. Genomic analysis of a nontoxigenic, invasive Corynebacterium diphtheriae strain from Brazil

    PubMed Central

    Encinas, Fernando; Marin, Michel A; Ramos, Juliana N; Vieira, Verônica V; Mattos-Guaraldi, Ana Luiza; Vicente, Ana Carolina P

    2015-01-01

    We report the complete genome sequence and analysis of an invasive Corynebacterium diphtheriae strain that caused endocarditis in Rio de Janeiro, Brazil. It was selected for sequencing on the basis of the current relevance of nontoxigenic strains for public health. The genomic information was explored in the context of diversity, plasticity and genetic relatedness with other contemporary strains. PMID:26517665

  10. Impact of herbivory on performance of Vincetoxicum spp., invasive weeds in North America

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The alien invasive vines Vincetoxicum rossicum and Vincetoxicum nigrum (swallow-wort) are of major concern in eastern North America, where both species invade forested landscapes and threaten faunal and plant diversity. Among the few native natural enemies reported in Eurasia, the specialist chryso...

  11. Genetic uniformity characterizes the invasive spread of water hyacinth (Eichhornia crassipes), a clonal aquatic plant.

    PubMed

    Zhang, Yuan-Ye; Zhang, Da-Yong; Barrett, Spencer C H

    2010-05-01

    Aquatic plant invasions are often associated with long-distance dispersal of vegetative propagules and prolific clonal reproduction. These reproductive features combined with genetic bottlenecks have the potential to severely limit genetic diversity in invasive populations. To investigate this question we conducted a global scale population genetic survey using amplified fragment length polymorphism markers of the world's most successful aquatic plant invader -Eichhornia crassipes (water hyacinth). We sampled 1140 ramets from 54 populations from the native (South America) and introduced range (Asia, Africa, Europe, North America, Central America and the Caribbean). Although we detected 49 clones, introduced populations exhibited very low genetic diversity and little differentiation compared with those from the native range, and approximately 80% of introduced populations were composed of a single clone. A widespread clone ('W') detected in two Peruvian populations accounted for 70.9% of the individuals sampled and dominated in 74.5% of the introduced populations. However, samples from Bangladesh and Indonesia were composed of different genotypes, implicating multiple introductions to the introduced range. Nine of 47 introduced populations contained clonal diversity suggesting that sexual recruitment occurs in some invasive sites where environmental conditions favour seedling establishment. The global patterns of genetic diversity in E. crassipes likely result from severe genetic bottlenecks during colonization and prolific clonal propagation. The prevalence of the 'W' genotype throughout the invasive range may be explained by stochastic sampling, or possibly because of pre-adaptation of the 'W' genotype to tolerate low temperatures. PMID:20529068

  12. Dispersal Polymorphisms in Invasive Fire Ants.

    PubMed

    Helms, Jackson A; Godfrey, Aaron

    2016-01-01

    In the Found or Fly (FoF) hypothesis ant queens experience reproduction-dispersal tradeoffs such that queens with heavier abdomens are better at founding colonies but are worse flyers. We tested predictions of FoF in two globally invasive fire ants, Solenopsis geminata (Fabricius, 1804) and S. invicta (Buren, 1972). Colonies of these species may produce two different monogyne queen types-claustral queens with heavy abdomens that found colonies independently, and parasitic queens with small abdomens that enter conspecific nests. Claustral and parasitic queens were similarly sized, but the abdomens of claustral queens weighed twice as much as those of their parasitic counterparts. Their heavier abdomens adversely impacted morphological predictors of flight ability, resulting in 32-38% lower flight muscle ratios, 55-63% higher wing loading, and 32-33% higher abdomen drag. In lab experiments maximum flight durations in claustral S. invicta queens decreased by about 18 minutes for every milligram of abdomen mass. Combining our results into a simple fitness tradeoff model, we calculated that an average parasitic S. invicta