WorldWideScience

Sample records for below-ground vertebrate herbivory

  1. Transcriptome analysis of food habit transition from carnivory to herbivory in a typical vertebrate herbivore, grass carp Ctenopharyngodon idella

    OpenAIRE

    He, Shan; Liang, Xu-Fang; Li, Ling; Sun, Jian; Wen, Zheng-Yong; Cheng, Xiao-Yan; Li, Ai-Xuan; Cai, Wen-Jing; He, Yu-Hui; Wang, Ya-ping; Tao, Ya-Xiong; Yuan, Xiao-Chen

    2015-01-01

    Background Although feeding behavior and food habit are ecologically and economically important properties, little is known about formation and evolution of herbivory. Grass carp (Ctenopharyngodon idella) is an ecologically appealing model of vertebrate herbivore, widely cultivated in the world as edible fish or as biological control agents for aquatic weeds. Grass carp exhibits food habit transition from carnivory to herbivory during development. However, currently little is known about the ...

  2. The oldest caseid synapsid from the Late Pennsylvanian of Kansas, and the evolution of herbivory in terrestrial vertebrates.

    Science.gov (United States)

    Reisz, Robert R; Fröbisch, Jörg

    2014-01-01

    The origin and early evolution of amniotes (fully terrestrial vertebrates) led to major changes in the structure and hierarchy of terrestrial ecosystems. The first appearance of herbivores played a pivotal role in this transformation. After an early bifurcation into Reptilia and Synapsida (including mammals) 315 Ma, synapsids dominated Paleozoic terrestrial vertebrate communities, with the herbivorous caseids representing the largest vertebrates on land. Eocasea martini gen. et sp. nov., a small carnivorous caseid from the Late Carboniferous, extends significantly the fossil record of Caseidae, and permits the first clade-based study of the origin and initial evolution of herbivory in terrestrial tetrapods. Our results demonstrate for the first time that large caseid herbivores evolved from small, non-herbivorous caseids. This pattern is mirrored by three other clades, documenting multiple, independent, but temporally staggered origins of herbivory and increase in body size among early terrestrial tetrapods, leading to patterns consistent with modern terrestrial ecosystem.

  3. Equivalence in the strength of deer herbivory on above and below ground communities

    DEFF Research Database (Denmark)

    Lessard, Jean-Philippe; Reynolds, W. Nicholas; Bunn, Windy A.

    2012-01-01

    Herbivores exert a strong influence on the species composition and richness of plant communities, but the magnitude of their effect on belowground communities remains poorly understood. While an increasing number of studies acknowledge the importance of documenting belowground effects of herbivor...

  4. Below-ground competitiveness of adult beech and spruce trees

    OpenAIRE

    Nikolova, Petia Simeonova

    2007-01-01

    The aim of the field study was to quantify the below-ground competitiveness of 50 to 60-year-old beech (Fagus sylvatica) and spruce (Picea abies) trees by means of space-related cost/benefit relationships. The study was conducted at the experimental site “Kranzberger Forst” within the framework of the interdisciplinary research program Sonderforschungsbereich 607 (SFB 607; Project B4) “Growth and Parasite Defence – Competition for Resources in Economical Plants from Agronomy and Forestry”. It...

  5. How to calculate stress in above/below ground transition

    Energy Technology Data Exchange (ETDEWEB)

    Schnackenberg, P.J.

    1976-11-01

    Stresses and deflections occur in natural gas pipe lines at the transition from the below ground (fully restrained) to the above ground (unrestrained) condition. Analysis of the stresses and deflections in transition areas, resulting from internal pressure/temperature change, is necessary in determining anchor block requirements and design. Longitudinal deflections are used to determine whether an anchor block is required. Anchor block forces required to maintain the pipe in a fully constrained condition are then determined. A brief review of the analysis that resulted in more accurate solutions for deflection and anchor block forces is presented. Sample calculations are given for line sizes up to 41-cm OD, pressure to 193 bars, and temperatures to 72/sup 0/C. (JRD)

  6. Are above- and below-ground phenology in sync?

    Science.gov (United States)

    Abramoff, Rose Z; Finzi, Adrien C

    2015-02-01

    Globally, root production accounts for 33-67% of terrestrial net primary productivity and influences decomposition via root production and turnover, carbon (C) allocation to mycorrhizal fungi and root exudation. As recognized above ground, the timing of phenological events affects terrestrial C balance, yet there is no parallel understanding for below-ground phenology. In this paper we examine the phenology of root production and its relationship to temperature, soil moisture, and above-ground phenology. Synthesizing 87 observations of whole-plant phenology from 40 studies, we found that, on average, root growth occurs 25 ± 8 d after shoot growth but that the offset between the peak in root and shoot growth varies > 200 d across biomes (boreal, temperate, Mediterranean, and subtropical). Root and shoot growth are positively correlated with median monthly temperature and mean monthly precipitation in boreal, temperate, and subtropical biomes. However, a temperature hysteresis in these biomes leads to the hypothesis that internal controls over C allocation to roots are an equally, if not more, important driver of phenology. The specific mechanisms are as yet unclear but they are likely mediated by some combination of photoassimilate supply, hormonal signaling, and growth form.

  7. Arbuscular mycorrhizal fungi alter above- and below-ground chemical defense expression differentially among Asclepias species

    Directory of Open Access Journals (Sweden)

    Rachel L Vannette

    2013-09-01

    Full Text Available Belowground symbionts of plants can have substantial influence on plant growth and nutrition. Recent work demonstrates that mycorrhizal fungi can affect plant resistance to herbivory and the performance of above and belowground herbivores. Although these examples emerge from diverse systems, it is unclear if plant species that express similar defensive traits respond similarly to fungal colonization, but comparative work may inform this question. To examine the effects of arbuscular mycorrhizal fungi (AMF on the expression of chemical resistance, we inoculated 8 species of Asclepias (milkweed--which all produce toxic cardenolides--with a community of AMF. We quantified plant biomass, foliar and root cardenolide concentration and composition, and assessed evidence for a growth-defense tradeoff in the presence and absence of AMF. As expected, total foliar and root cardenolide concentration varied among milkweed species. Importantly, the effect of mycorrhizal fungi on total foliar cardenolide concentration also varied among milkweed species, with foliar cardenolides increasing or decreasing, depending on the plant species. We detected a phylogenetic signal to this variation; AMF fungi reduced foliar cardenolide concentrations to a greater extent in the clade including A. curassavica than in the clade including A. syriaca. Moreover, AMF inoculation shifted the composition of cardenolides in above- and below-ground plant tissues in a species-specific fashion. Mycorrhizal inoculation changed the relative distribution of cardenolides between root and shoot tissue in a species-specific fashion, but did not affect cardenolide diversity or polarity. Finally, a tradeoff between plant growth and defense in non-mycorrhizal plants was mitigated completely by AMF inoculation. Overall, we conclude that the effects of AMF inoculation on the expression of chemical resistance can vary among congeneric plant species, and ameliorate tradeoffs between growth and

  8. Evolutionary biology of plant defenses against herbivory and their predictive implications for endocrine disruptor susceptibility in vertebrates.

    OpenAIRE

    Wynne-Edwards, K E

    2001-01-01

    Hormone disruption is a major, underappreciated component of the plant chemical arsenal, and the historical coevolution between hormone-disrupting plants and herbivores will have both increased the susceptibility of carnivores and diversified the sensitivities of herbivores to man-made endocrine disruptors. Here I review diverse evidence of the influence of plant secondary compounds on vertebrate reproduction, including human reproduction. Three of the testable hypotheses about the evolutiona...

  9. EnviroAtlas - Below Ground Live Tree Biomass Carbon Storage for the Conterminous United States- Forested

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset includes the average below ground live tree root dry biomass estimate for the Watershed Boundary Dataset (WBD) 12-digit Hydrologic Unit...

  10. Recurrent evolution of herbivory in small, cold-climate lizards: Breaking the ecophysiological rules of reptilian herbivory

    OpenAIRE

    Espinoza, Robert E.; Wiens, John J.; Tracy, C. Richard

    2004-01-01

    Herbivory has evolved in many groups of vertebrates, but it is rare among both extinct and extant nonavian reptiles. Among squamate reptiles, (lizards, snakes, and their relatives), 7,800 species are considered to be herbivorous, and herbivory is restricted to lizards. Here, we show that within a group of South American lizards (Liolaemidae, ≈170 species), herbivory has evolved more frequently than in all other squamates combined and at a rate estimated to be >65 times faster. Furthermore, in...

  11. Above- and below-ground net primary productivity across ten Amazonian forests on contrasting soils

    Directory of Open Access Journals (Sweden)

    L. E. O. C. Aragão

    2009-12-01

    Full Text Available The net primary productivity (NPP of tropical forests is one of the most important and least quantified components of the global carbon cycle. Most relevant studies have focused particularly on the quantification of the above-ground coarse wood productivity, and little is known about the carbon fluxes involved in other elements of the NPP, the partitioning of total NPP between its above- and below-ground components and the main environmental drivers of these patterns. In this study we quantify the above- and below-ground NPP of ten Amazonian forests to address two questions: (1 How do Amazonian forests allocate productivity among its above- and below-ground components? (2 How do soil and leaf nutrient status and soil texture affect the productivity of Amazonian forests? Using a standardized methodology to measure the major elements of productivity, we show that NPP varies between 9.3±1.3 Mg C ha−1 yr−1 (mean±standard error, at a white sand plot, and 17.0±1.4 Mg C ha−1 yr−1 at a very fertile Terra Preta site, with an overall average of 12.8±0.9 Mg C ha−1 yr−1. The studied forests allocate on average 64±3% and 36±3% of the total NPP to the above- and below-ground components, respectively. The ratio of above-ground and below-ground NPP is almost invariant with total NPP. Litterfall and fine root production both increase with total NPP, while stem production shows no overall trend. Total NPP tends to increase with soil phosphorus and leaf nitrogen status. However, allocation of NPP to below-ground shows no relationship to soil fertility, but appears to decrease with the increase of soil clay content.

  12. Above- and below-ground net primary productivity across ten Amazonian forests on contrasting soils

    Directory of Open Access Journals (Sweden)

    L. E. O. C. Aragão

    2009-02-01

    Full Text Available The net primary productivity (NPP of tropical forests is one of the most important and least quantified components of the global carbon cycle. Most relevant studies have focused particularly on the quantification of the above-ground coarse wood productivity, and little is known about the carbon fluxes involved in other elements of the NPP, the partitioning of total NPP between its above- and below-ground components and the main environmental drivers of these patterns. In this study we quantify the above- and below-ground NPP of ten Amazonian forests to address two questions: (1 How do Amazonian forests allocate productivity among its above- and below-ground components? (2 How do soil and leaf nutrient status and soil texture affect the productivity of Amazonian forests? Using a standardized methodology to measure the major elements of productivity, we show that NPP varies between 9.3±1.3 Mg C ha−1 yr−1 (mean±standard error, at a white sand plot, and 17.0±1.4 Mg C ha−1 yr−1 at a very fertile Terra Preta site, with an overall average of 12.8±0.9 Mg C ha−1 yr−1. The studied forests allocate on average 64±3% and 36±3% of the total NPP to the above- and below-ground components, respectively. The ratio of above-ground and below-ground NPP is almost invariant with total NPP. Litterfall and fine root production both increase with total NPP, while stem production shows no overall trend. Total NPP tends to increase with soil phosphorus and leaf nitrogen status. However, allocation of NPP to below-ground shows no relationship to soil fertility, but appears to decrease with the increase of soil clay content.

  13. Imaging spectroscopy links aspen genotype with below-ground processes at landscape scales.

    Science.gov (United States)

    Madritch, Michael D; Kingdon, Clayton C; Singh, Aditya; Mock, Karen E; Lindroth, Richard L; Townsend, Philip A

    2014-01-01

    Fine-scale biodiversity is increasingly recognized as important to ecosystem-level processes. Remote sensing technologies have great potential to estimate both biodiversity and ecosystem function over large spatial scales. Here, we demonstrate the capacity of imaging spectroscopy to discriminate among genotypes of Populus tremuloides (trembling aspen), one of the most genetically diverse and widespread forest species in North America. We combine imaging spectroscopy (AVIRIS) data with genetic, phytochemical, microbial and biogeochemical data to determine how intraspecific plant genetic variation influences below-ground processes at landscape scales. We demonstrate that both canopy chemistry and below-ground processes vary over large spatial scales (continental) according to aspen genotype. Imaging spectrometer data distinguish aspen genotypes through variation in canopy spectral signature. In addition, foliar spectral variation correlates well with variation in canopy chemistry, especially condensed tannins. Variation in aspen canopy chemistry, in turn, is correlated with variation in below-ground processes. Variation in spectra also correlates well with variation in soil traits. These findings indicate that forest tree species can create spatial mosaics of ecosystem functioning across large spatial scales and that these patterns can be quantified via remote sensing techniques. Moreover, they demonstrate the utility of using optical properties as proxies for fine-scale measurements of biodiversity over large spatial scales.

  14. Below-ground carbon transfer among Betula nana may increase with warming in Arctic tundra.

    Science.gov (United States)

    Deslippe, Julie R; Simard, Suzanne W

    2011-11-01

    • Shrubs are expanding in Arctic tundra, but the role of mycorrhizal fungi in this process is unknown. We tested the hypothesis that mycorrhizal networks are involved in interplant carbon (C) transfer within a tundra plant community. • Here, we installed below-ground treatments to control for C transfer pathways and conducted a (13)CO(2)-pulse-chase labelling experiment to examine C transfer among and within plant species. • We showed that mycorrhizal networks exist in tundra, and facilitate below-ground transfer of C among Betula nana individuals, but not between or within the other tundra species examined. Total C transfer among conspecific B. nana pairs was 10.7 ± 2.4% of photosynthesis, with the majority of C transferred through rhizomes or root grafts (5.2 ± 5.3%) and mycorrhizal network pathways (4.1 ± 3.3%) and very little through soil pathways (1.4 ± 0.35%). • Below-ground C transfer was of sufficient magnitude to potentially alter plant interactions in Arctic tundra, increasing the competitive ability and mono-dominance of B. nana. C transfer was significantly positively related to ambient temperatures, suggesting that it may act as a positive feedback to ecosystem change as climate warms.

  15. Allometric scaling relationship between above- and below-ground biomass within and across five woody seedlings.

    Science.gov (United States)

    Cheng, Dongliang; Ma, Yuzhu; Zhong, Quanling; Xu, Weifeng

    2014-10-01

    Allometric biomass allocation theory predicts that leaf biomass (M L ) scaled isometrically with stem (M S ) and root (M R ) biomass, and thus above-ground biomass (leaf and stem) (M A ) and root (M R ) scaled nearly isometrically with below-ground biomass (root) for tree seedlings across a wide diversity of taxa. Furthermore, prior studies also imply that scaling constant should vary with species. However, litter is known about whether such invariant isometric scaling exponents hold for intraspecific biomass allocation, and how variation in scaling constants influences the interspecific scaling relationship between above- and below-ground biomass. Biomass data of seedlings from five evergreen species were examined to test scaling relationships among biomass components across and within species. Model Type II regression was used to compare the numerical values of scaling exponents and constants among leaf, stem, root, and above- to below-ground biomass. The results indicated that M L and M S scaled in an isometric or a nearly isometric manner with M R , as well as M A to M R for five woody species. Significant variation was observed in the Y-intercepts of the biomass scaling curves, resulting in the divergence for intraspecific scaling and interspecific scaling relationships for M L versus M S and M L versus M R , but not for M S versus M R and M A versus M R . We conclude, therefore, that a nearly isometric scaling relationship of M A versus M R holds true within each of the studied woody species and across them irrespective the negative scaling relationship between leaf and stem.

  16. Untangling positive and negative biotic interactions: views from above and below ground in a forest ecosystem.

    Science.gov (United States)

    Montgomery, Rebecca A; Reich, Peter B; Palik, Brian J

    2010-12-01

    In ecological communities, the outcome of plant-plant interactions represents the net effect of positive and negative interactions occurring above and below ground. Untangling these complex relationships can provide a better understanding of mechanisms that underlie plant-plant interactions and enhance our ability to predict population, community, and ecosystem effects of biotic interactions. In forested ecosystems, tree seedlings interact with established vegetation, but the mechanisms and outcomes of these interactions are not well understood. To explore such mechanisms, we manipulated above- and belowground interactions among tree seedlings, shrubs, and trees and monitored seedling survival and growth of six species (Pinus banksiana, Betula papyrifera, P. resinosa, Quercus rubra, P. strobus, and Acer rubrum) in mature pine-dominated forest in northern Minnesota, USA. The forest had a moderately open canopy and sandy soils. Understory manipulations were implemented in the forest interior and in large gaps and included removal of shrubs (no interactions), tieback of shrubs (belowground), removal of shrubs with addition of shade (aboveground), and unmanipulated shrubs (both below- and aboveground). We found that shrubs either suppressed or facilitated seedling survival and growth depending on the seedling species, source of interaction (e.g., above- or belowground), and ecological context (e.g., gap or forest interior). In general, shrubs strongly influenced survival and growth in gaps, with more modest effects in the forest interior. In gaps, the presence of shrub roots markedly decreased seedling growth and survival, supporting the idea that belowground competition may be more important in dry, nutrient-poor sites. Shrub shade effects were neutral for three species and facilitative for the other three. Facilitation was more likely for shade-tolerant species. In the forest interior, shrub shade negatively affected seedling survival for the most shade

  17. Soil Organic Carbon and Below Ground Biomass: Development of New GLOBE Special Measurements

    Science.gov (United States)

    Levine, Elissa; Haskett, Jonathan

    1999-01-01

    A scientific consensus is building that changes in the atmospheric concentrations of radiatively active gases are changing the climate (IPCC, 1990). One of these gases CO2 has been increasing in concentration due to additions from anthropogenic sources that are primarily industrial and land use related. The soil contains a very large pool of carbon, estimated at 1550 Gt (Lal 1995) which is larger than the atmospheric and biosphere pools of carbon combined (Greenland, 1995). The flux between the soil and the atmosphere is very large, 60 Pg C/yr (Lal 1997), and is especially important because the soil can act as either a source or a sink for carbon. On any given landscape, as much as 50% of the biomass that provides the major source of carbon can be below ground. In addition, the movement of carbon in and out of the soil is mediated by the living organisms. At present, there is no widespread sampling of soil biomass in any consistent or coordinated manner. Current large scale estimates of soil carbon are limited by the number and widely dispersed nature of the data points available. A measurement of the amount of carbon in the soil would supplement existing carbon data bases as well as provide a benchmark that can be used to determine whether the soil is storing carbon or releasing it to the atmosphere. Information on the below ground biomass would be a valuable addition to our understanding of net primary productivity and standing biomass. The addition of these as special measurements within GLOBE would be unique in terms of areal extent and continuity, and make a real contribution to scientific understanding of carbon dynamics.

  18. Interactive effect of herbivory and competition on the invasive plant Mikania micrantha.

    Science.gov (United States)

    Li, Junmin; Xiao, Tao; Zhang, Qiong; Dong, Ming

    2013-01-01

    A considerable number of host-specific biological control agents fail to control invasive plants in the field, and exploring the mechanism underlying this phenomenon is important and helpful for the management of invasive plants. Herbivory and competition are two of the most common biotic stressors encountered by invasive plants in their recipient communities. We predicted that the antagonistic interactive effect between herbivory and competition would weaken the effect of herbivory on invasive plants and result in the failure of herbivory to control invasive plants. To examine this prediction, thus, we conducted an experiment in which both invasive Mikania micrantha and native Coix lacryma-job i were grown together and subjected to herbivory-mimicking defoliation. Both defoliation and competition had significantly negative effects on the growth of the invader. However, the negative effect of 75% respective defoliation on the above- and below-ground biomass of Mikania micrantha was alleviated by presence of Coix lacryma-jobi. The negative effect of competition on the above- and below-ground biomass was equally compensated at 25%, 50% and 100% defoliation and overcompensated at 75% defoliation. The interactive effect was antagonistic and dependent on the defoliation intensity, with the maximum effect at 75% defoliation. The antagonistic interaction between defoliation and competition appears to be able to release the invader from competition, thus facilitating the invasiveness of Mikania, a situation that might make herbivory fail to inhibit the growth of invasive Mikania in the invaded community.

  19. Ectomycorrhizal communities above and below ground and truffle productivity in a Tuber aestivum orchard

    Directory of Open Access Journals (Sweden)

    Elena Salerni

    2014-08-01

    Full Text Available Aim of study: The diversity of ectomycorrhizal fungal communities (EM above (EMFb and below (EMMt ground associated with Quercus cerris L., Q. pubescens Willd., and Pinus nigra J.F.Arnold was analyzed.Area of study: A 20 year-old orchard that produces Tuber aestivum truffles, located a few kilometers from Chiusi della Verna (latitude 43° 41’ 53’’; longitude 11° 56’ 9’’ in Tuscany (central Italy was observed.Material and Methods: This investigation combined analyses of EMFb, EMMt, T. aestivum productivity, different host trees, and statistical data on community ecology.Main results: The EM communities showed high species richness and differed slightly in relation to both the host tree and their location above or below ground, providing frequent findings of Tricholoma and Tomentella, respectively. Positive correlations were found between the number of truffles and host trees, and between the weight and number of truffles and EMFb.Research highlights: Mycorrhizal fungi and truffle production are not in competition.Key words: Fungal communities; fruiting bodies; morphotypes; Tuber aestivum; competition; Italy.

  20. Planting depth and rhizome size effects on below ground growth of licorice (Glycyrrhiza glabra L.

    Directory of Open Access Journals (Sweden)

    reza vali allah poor

    2009-06-01

    Full Text Available An experiment was carried out to evaluate the effects of planting depth and rhizome sizes on below ground growth of licorice (Glycyrrhiza glabra L. at research glasshouse of Mashhad Unversity in 2001. Factorial experiment containing 2 factors of planting depth (10, 20 and 40‌cm and rhizome sizes (1,2 and 3 buds or 4,7 and 10 gr with two replications in completely randomized block design was employed. Development of different variables during growing season including root and mother rhizome dry weight were measured.The highest and the lowest root dry weight (RDWhave been seen in depth of 20 and 40 cm‌, respectively. About 100 days after planting (DAP, RDW increaseed very slowly but thenafter increased faster‌. Rhizome of any sizes in‌ 20 cm, gave the highest RDW‌. Three-bud rhizomes produced the highest RDW and 1-bud rhizome produced the lowest. Mother rhizome dry weight (MRDW reduced untill 60 days after planting. After 75th day, MRDW has increased and all plants started to fill their mother rhizome and finally rhizome of depth 20 cm produced the highest dry weight. In 160 days after planting, mother rhizomes started to lose their weight‌. 1and 3 -bud mother rhizome produce the lowest and highest MRDW, respectively.

  1. Root proliferation and seed yield in response to spatial heterogeneity of below-ground competition.

    Science.gov (United States)

    O'Brien, Erin E; Gersani, Mordechai; Brown, Joel S

    2005-11-01

    Here, we tested the predictions of a 'tragedy of the commons' model of below-ground plant competition in annual plants that experience spatial heterogeneity in their competitive environment. Under interplant competition, the model predicts that a plant should over-proliferate roots relative to what would maximize the collective yield of the plants. We predict that a plant will tailor its root proliferation to local patch conditions, restraining root production when alone and over-proliferating in the presence of other plants. A series of experiments were conducted using pairs of pea (Pisum sativum) plants occupying two or three pots in which the presence or absence of interplant root competition was varied while nutrient availability per plant was held constant. In two-pot experiments, competing plants produced more root mass and less pod mass per individual than plants grown in isolation. In three-pot experiments, peas modulated this response to conditions at the scale of individual pots. Root proliferation in the shared pot was higher compared with the exclusively occupied pot. Plants appear to display sophisticated nutrient foraging with outcomes that permit insights into interplant competition.

  2. Links between plant litter chemistry, species diversity, and below-ground ecosystem function.

    Science.gov (United States)

    Meier, Courtney L; Bowman, William D

    2008-12-16

    Decomposition is a critical source of plant nutrients, and drives the largest flux of terrestrial C to the atmosphere. Decomposing soil organic matter typically contains litter from multiple plant species, yet we lack a mechanistic understanding of how species diversity influences decomposition processes. Here, we show that soil C and N cycling during decomposition are controlled by the composition and diversity of chemical compounds within plant litter mixtures, rather than by simple metrics of plant species diversity. We amended native soils with litter mixtures containing up to 4 alpine plant species, and we used 9 litter chemical traits to evaluate the chemical composition (i.e., the identity and quantity of compounds) and chemical diversity of the litter mixtures. The chemical composition of the litter mixtures was the strongest predictor of soil respiration, net N mineralization, and microbial biomass N. Soil respiration and net N mineralization rates were also significantly correlated with the chemical diversity of the litter mixtures. In contrast, soil C and N cycling rates were poorly correlated with plant species richness, and there was no relationship between species richness and the chemical diversity of the litter mixtures. These results indicate that the composition and diversity of chemical compounds in litter are potentially important functional traits affecting decomposition, and simple metrics like plant species richness may fail to capture variation in these traits. Litter chemical traits therefore provide a mechanistic link between organisms, species diversity, and key components of below-ground ecosystem function.

  3. Redefining fine roots improves understanding of below-ground contributions to terrestrial biosphere processes.

    Science.gov (United States)

    McCormack, M Luke; Dickie, Ian A; Eissenstat, David M; Fahey, Timothy J; Fernandez, Christopher W; Guo, Dali; Helmisaari, Heljä-Sisko; Hobbie, Erik A; Iversen, Colleen M; Jackson, Robert B; Leppälammi-Kujansuu, Jaana; Norby, Richard J; Phillips, Richard P; Pregitzer, Kurt S; Pritchard, Seth G; Rewald, Boris; Zadworny, Marcin

    2015-08-01

    Fine roots acquire essential soil resources and mediate biogeochemical cycling in terrestrial ecosystems. Estimates of carbon and nutrient allocation to build and maintain these structures remain uncertain because of the challenges of consistently measuring and interpreting fine-root systems. Traditionally, fine roots have been defined as all roots ≤ 2 mm in diameter, yet it is now recognized that this approach fails to capture the diversity of form and function observed among fine-root orders. Here, we demonstrate how order-based and functional classification frameworks improve our understanding of dynamic root processes in ecosystems dominated by perennial plants. In these frameworks, fine roots are either separated into individual root orders or functionally defined into a shorter-lived absorptive pool and a longer-lived transport fine-root pool. Using these frameworks, we estimate that fine-root production and turnover represent 22% of terrestrial net primary production globally - a c. 30% reduction from previous estimates assuming a single fine-root pool. Future work developing tools to rapidly differentiate functional fine-root classes, explicit incorporation of mycorrhizal fungi into fine-root studies, and wider adoption of a two-pool approach to model fine roots provide opportunities to better understand below-ground processes in the terrestrial biosphere.

  4. Shrub encroachment in Arctic tundra: Betula nana effects on above- and below-ground litter decomposition.

    Science.gov (United States)

    McLaren, Jennie R; Buckeridge, Kate M; van de Weg, Martine J; Shaver, Gaius R; Schimel, Joshua P; Gough, Laura

    2017-03-06

    Rapid arctic vegetation change as a result of global warming includes an increase in the cover and biomass of deciduous shrubs. Increases in shrub abundance will result in a proportional increase of shrub litter in the litter community, potentially affecting carbon turnover rates in arctic ecosystems. We investigated the effects of leaf and root litter of a deciduous shrub, Betula nana, on decomposition, by examining species-specific decomposition patterns, as well as effects of Betula litter on the decomposition of other species. We conducted a two-year decomposition experiment in moist acidic tundra in northern Alaska, where we decomposed three tundra species (Vaccinium vitis-idaea, Rhododendron palustre, and Eriophorum vaginatum) alone and in combination with Betula litter. Decomposition patterns for leaf and root litter were determined using three different measures of decomposition (mass loss, respiration, extracellular enzyme activity). We report faster decomposition of Betula leaf litter compared to other species, with support for species differences coming from all three measures of decomposition. Mixing effects were less consistent among the measures, with negative mixing effects shown only for mass loss. In contrast, there were few species differences or mixing effects for root decomposition. Overall, we attribute longer-term litter mass loss patterns in to patterns created by early decomposition processes in the first winter. We note numerous differences for species patterns between leaf and root decomposition, indicating that conclusions from leaf litter experiments should not be extrapolated to below-ground decomposition. The high decomposition rates of Betula leaf litter aboveground, and relatively similar decomposition rates of multiple species below, suggest a potential for increases in turnover in the fast-decomposing carbon pool of leaves and fine roots as the dominance of deciduous shrubs in the Arctic increases, but this outcome may be tempered

  5. Mapping Above- and Below-Ground Carbon Pools in Boreal Forests: The Case for Airborne Lidar.

    Science.gov (United States)

    Kristensen, Terje; Næsset, Erik; Ohlson, Mikael; Bolstad, Paul V; Kolka, Randall

    2015-01-01

    A large and growing body of evidence has demonstrated that airborne scanning light detection and ranging (lidar) systems can be an effective tool in measuring and monitoring above-ground forest tree biomass. However, the potential of lidar as an all-round tool for assisting in assessment of carbon (C) stocks in soil and non-tree vegetation components of the forest ecosystem has been given much less attention. Here we combine the use airborne small footprint scanning lidar with fine-scale spatial C data relating to vegetation and the soil surface to describe and contrast the size and spatial distribution of C pools within and among multilayered Norway spruce (Picea abies) stands. Predictor variables from lidar derived metrics delivered precise models of above- and below-ground tree C, which comprised the largest C pool in our study stands. We also found evidence that lidar canopy data correlated well with the variation in field layer C stock, consisting mainly of ericaceous dwarf shrubs and herbaceous plants. However, lidar metrics derived directly from understory echoes did not yield significant models. Furthermore, our results indicate that the variation in both the mosses and soil organic layer C stock plots appears less influenced by differences in stand structure properties than topographical gradients. By using topographical models from lidar ground returns we were able to establish a strong correlation between lidar data and the organic layer C stock at a stand level. Increasing the topographical resolution from plot averages (~2000 m2) towards individual grid cells (1 m2) did not yield consistent models. Our study demonstrates a connection between the size and distribution of different forest C pools and models derived from airborne lidar data, providing a foundation for future research concerning the use of lidar for assessing and monitoring boreal forest C.

  6. Above- and below-ground competition in high and low irradiance: tree seedling responses to a competing liana Byttneria grandifolia

    NARCIS (Netherlands)

    Chen, J.Y.; Bongers, F.; Cao, K.F.; Cai, Z.Q.

    2008-01-01

    Abstract: In tropical forests, trees compete not only with other trees, but also with lianas, which may limit tree growth and regeneration. Liana effects may depend on the availability of above- and below-ground resources and differ between tree species. We conducted a shade house experiment to test

  7. A fungal endophyte helps plants to tolerate root herbivory through changes in gibberellin and jasmonate signaling.

    Science.gov (United States)

    Cosme, Marco; Lu, Jing; Erb, Matthias; Stout, Michael Joseph; Franken, Philipp; Wurst, Susanne

    2016-08-01

    Plant-microbe mutualisms can improve plant defense, but the impact of root endophytes on below-ground herbivore interactions remains unknown. We investigated the effects of the root endophyte Piriformospora indica on interactions between rice (Oryza sativa) plants and its root herbivore rice water weevil (RWW; Lissorhoptrus oryzophilus), and how plant jasmonic acid (JA) and GA regulate this tripartite interaction. Glasshouse experiments with wild-type rice and coi1-18 and Eui1-OX mutants combined with nutrient, jasmonate and gene expression analyses were used to test: whether RWW adult herbivory above ground influences subsequent damage caused by larval herbivory below ground; whether P. indica protects plants against RWW; and whether GA and JA signaling mediate these interactions. The endophyte induced plant tolerance to root herbivory. RWW adults and larvae acted synergistically via JA signaling to reduce root growth, while endophyte-elicited GA biosynthesis suppressed the herbivore-induced JA in roots and recovered plant growth. Our study shows for the first time the impact of a root endophyte on plant defense against below-ground herbivores, adds to growing evidence that induced tolerance may be an important root defense, and implicates GA as a signal component of inducible plant tolerance against biotic stress.

  8. Recurrent evolution of herbivory in small, cold-climate lizards: breaking the ecophysiological rules of reptilian herbivory.

    Science.gov (United States)

    Espinoza, Robert E; Wiens, John J; Tracy, C Richard

    2004-11-30

    Herbivory has evolved in many groups of vertebrates, but it is rare among both extinct and extant nonavian reptiles. Among squamate reptiles, (lizards, snakes, and their relatives), 7,800 species are considered to be herbivorous, and herbivory is restricted to lizards. Here, we show that within a group of South American lizards (Liolaemidae, approximately 170 species), herbivory has evolved more frequently than in all other squamates combined and at a rate estimated to be >65 times faster. Furthermore, in contrast to other herbivorous lizards and to existing theory, most herbivorous liolaemids are small bodied and live in cool climates. Herbivory is generally thought to evolve only in reptile species that are large bodied, live in warm climates, and maintain high body temperatures. These three well known "rules" of herbivory are considered to form the bases of physiological constraints that explain the paucity of herbivorous reptile species. We suggest that the recurrent and paradoxical evolution of herbivory in liolaemids is explained by a combination of environmental conditions (promoting independent origins of herbivory in isolated cool-climate regions), ecophysiological constraints (requiring small body size in cool climates, yet high body temperatures for herbivores), and phylogenetic history. More generally, our study demonstrates how integrating information from ecophysiology and phylogeny can help to explain macroevolutionary trends.

  9. Drought and root herbivory interact to alter the response of above-ground parasitoids to aphid infested plants and associated plant volatile signals.

    Directory of Open Access Journals (Sweden)

    Muhammad Tariq

    Full Text Available Multitrophic interactions are likely to be altered by climate change but there is little empirical evidence relating the responses of herbivores and parasitoids to abiotic factors. Here we investigated the effects of drought on an above/below-ground system comprising a generalist and a specialist aphid species (foliar herbivores, their parasitoids, and a dipteran species (root herbivore.We tested the hypotheses that: (1 high levels of drought stress and below-ground herbivory interact to reduce the performance of parasitoids developing in aphids; (2 drought stress and root herbivory change the profile of volatile organic chemicals (VOCs emitted by the host plant; (3 parasitoids avoid ovipositing in aphids feeding on plants under drought stress and root herbivory. We examined the effect of drought, with and without root herbivory, on the olfactory response of parasitoids (preference, plant volatile emissions, parasitism success (performance, and the effect of drought on root herbivory. Under drought, percentage parasitism of aphids was reduced by about 40-55% compared with well watered plants. There was a significant interaction between drought and root herbivory on the efficacy of the two parasitoid species, drought stress partially reversing the negative effect of root herbivory on percent parasitism. In the absence of drought, root herbivory significantly reduced the performance (e.g. fecundity of both parasitoid species developing in foliar herbivores. Plant emissions of VOCs were reduced by drought and root herbivores, and in olfactometer experiments parasitoids preferred the odour from well-watered plants compared with other treatments. The present work demonstrates that drought stress can change the outcome of interactions between herbivores feeding above- and below-ground and their parasitoids, mediated by changes in the chemical signals from plants to parasitoids. This provides a new insight into how the structure of terrestrial

  10. Simulated Sea-Level Rise Effects on the Above and Below-Ground Growth of Two Tidal Marsh Plant Species

    Science.gov (United States)

    Schile, L. M.; Callaway, J. C.; Kelly, M.

    2011-12-01

    Sea-level is expected to rise between 55 and 140 cm in the next century and is likely to have significant effects on the distribution and maintenance of tidal wetlands; however, little is known about the effects of increased sea level on Pacific coast tidal marsh vegetation. We initiated a field experiment in March 2011 to examine how increased depth and duration of inundation affect above and below-ground growth of two tidal wetland plant species: Schoenoplectus acutus and S. americanus. PVC planters, referred to as marsh organs, were installed at fixed elevations in channels at two ancient marshes in the San Francisco Bay Estuary: Browns Island and Rush Ranch. Each marsh organ structure is comprised of five rows of three six-inch PVC pipes, with each row 15cm lower than the row above, and was filled with surrounding mudflat sediment. Elevations span 60 cm and were chosen to be lower than the average current elevations of both species at each marsh to reflect projected increases in sea level. Rhizomes were collected from Browns Island, the less-saline site, and were cut to uniform sizes before planting. In every row, each species was grown individually and together. On a monthly basis, plant heights were recorded and pore-water sulfide concentration, salinity, and soil oxidation-reduction potential were measured. Schoenoplectus americanus growth and density significantly decreased with increased inundation at both sites. Schoenoplectus acutus growth was impacted more significantly at lower elevations at Rush Ranch but had little variation in density and growth across elevations at Browns Island. Salinity and sulfide concentrations varied little across elevations within a site but differed between sites. Above and belowground biomass will be collected in September 2011 to measure total annual productivity. The experiment provides basic yet crucial information on the impacts of increased inundation on tidal wetland vegetation and insight into potential changes in

  11. Luxury consumption of soil nutrients: a possible competitive strategy in above-ground and below-ground biomass allocation and root morphology for slow-growing arctic vegetation?

    NARCIS (Netherlands)

    Wijk, van M.T.; Williams, M.; Gough, L.; Hobbie, S.E.; Shaver, G.R.

    2003-01-01

    1 A field-experiment was used to determine how plant species might retain dominance in an arctic ecosystem receiving added nutrients. We both measured and modelled the above-ground and below-ground biomass allocation and root morphology of non-acidic tussock tundra near Toolik Lake, Alaska, after 4

  12. Understory Plant Community Composition Is Associated with Fine-Scale Above- and Below-Ground Resource Heterogeneity in Mature Lodgepole Pine (Pinus contorta Forests.

    Directory of Open Access Journals (Sweden)

    Anne C S McIntosh

    Full Text Available Understory plant communities play critical ecological roles in forest ecosystems. Both above- and below-ground ecosystem properties and processes influence these communities but relatively little is known about such effects at fine (i.e., one to several meters within-stand scales, particularly for forests in which the canopy is dominated by a single species. An improved understanding of these effects is critical for understanding how understory biodiversity is regulated in such forests and for anticipating impacts of changing disturbance regimes. Our primary objective was to examine the patterns of fine-scale variation in understory plant communities and their relationships to above- and below-ground resource and environmental heterogeneity within mature lodgepole pine forests. We assessed composition and diversity of understory vegetation in relation to heterogeneity of both the above-ground (canopy tree density, canopy and tall shrub basal area and cover, downed wood biomass, litter cover and below-ground (soil nutrient availability, decomposition, forest floor thickness, pH, and phospholipid fatty acids (PLFAs and multiple carbon-source substrate-induced respiration (MSIR of the forest floor microbial community environment. There was notable variation in fine-scale plant community composition; cluster and indicator species analyses of the 24 most commonly occurring understory species distinguished four assemblages, one for which a pioneer forb species had the highest cover levels, and three others that were characterized by different bryophyte species having the highest cover. Constrained ordination (distance-based redundancy analysis showed that two above-ground (mean tree diameter, litter cover and eight below-ground (forest floor pH, plant available boron, microbial community composition and function as indicated by MSIR and PLFAs properties were associated with variation in understory plant community composition. These results provide

  13. Understory Plant Community Composition Is Associated with Fine-Scale Above- and Below-Ground Resource Heterogeneity in Mature Lodgepole Pine (Pinus contorta) Forests.

    Science.gov (United States)

    McIntosh, Anne C S; Macdonald, S Ellen; Quideau, Sylvie A

    2016-01-01

    Understory plant communities play critical ecological roles in forest ecosystems. Both above- and below-ground ecosystem properties and processes influence these communities but relatively little is known about such effects at fine (i.e., one to several meters within-stand) scales, particularly for forests in which the canopy is dominated by a single species. An improved understanding of these effects is critical for understanding how understory biodiversity is regulated in such forests and for anticipating impacts of changing disturbance regimes. Our primary objective was to examine the patterns of fine-scale variation in understory plant communities and their relationships to above- and below-ground resource and environmental heterogeneity within mature lodgepole pine forests. We assessed composition and diversity of understory vegetation in relation to heterogeneity of both the above-ground (canopy tree density, canopy and tall shrub basal area and cover, downed wood biomass, litter cover) and below-ground (soil nutrient availability, decomposition, forest floor thickness, pH, and phospholipid fatty acids (PLFAs) and multiple carbon-source substrate-induced respiration (MSIR) of the forest floor microbial community) environment. There was notable variation in fine-scale plant community composition; cluster and indicator species analyses of the 24 most commonly occurring understory species distinguished four assemblages, one for which a pioneer forb species had the highest cover levels, and three others that were characterized by different bryophyte species having the highest cover. Constrained ordination (distance-based redundancy analysis) showed that two above-ground (mean tree diameter, litter cover) and eight below-ground (forest floor pH, plant available boron, microbial community composition and function as indicated by MSIR and PLFAs) properties were associated with variation in understory plant community composition. These results provide novel insights

  14. Epiphyte-cover on seagrass (Zostera marina L. leaves impedes plant performance and radial O2 loss from the below-ground tissue

    Directory of Open Access Journals (Sweden)

    Kasper Elgetti Brodersen

    2015-08-01

    Full Text Available The O2 budget of seagrasses is a complex interaction between several sources and sinks, which is strongly regulated by light availability and mass transfer over the diffusive boundary layer (DBL surrounding the plant. Epiphyte growth on leaves may thus strongly affect the O2 availability of the seagrass plant and its capability to aerate its rhizosphere as a defence against plant toxins.We used electrochemical and fiber-optic microsensors to quantify the O2 flux, DBL and light microclimate around leaves with and without filamentous algal epiphytes. We also quantified the below-ground radial O2 loss from roots (~1 mm from the root-apex to elucidate how this below-ground oxic microzone was affected by the presence of epiphytes.Epiphyte-cover on seagrass leaves (~21% areal cover resulted in reduced light quality and quantity for photosynthesis, thus leading to reduced plant fitness. A ~4 times thicker diffusive boundary layer around leaves with epiphyte-cover impeded gas (and nutrient exchange with the surrounding water-column and thus the amount of O2 passively diffusing into the leaves in darkness. During light exposure of the leaves, radial oxygen loss from the below-ground tissue was ~2 times higher from plants without epiphyte-cover. In contrast, no O2 was detectable at the surface of the root-cap tissue of plants with epiphyte-cover during darkness, leaving the plants more susceptible to sulphide intrusion.Epiphyte growth on seagrass leaves thus negatively affects the light climate and O2 uptake in darkness, hampering the plants performance and thereby reducing the oxidation capability of its below-ground tissue.

  15. Spider silk reduces insect herbivory.

    Science.gov (United States)

    Rypstra, Ann L; Buddle, Christopher M

    2013-02-23

    The role of predators in food webs extends beyond their ability to kill and consume prey. Such trait-mediated effects occur when signals of the predator influence the behaviour of other animals. Because all spiders are silk-producing carnivores, we hypothesized that silk alone would signal other arthropods and enhance non-lethal effects of spiders. We quantified the herbivory inflicted by two beetle species on green bean plants (Phaseolus vulgaris) in the presence of silkworm silk and spider silk along with no silk controls. Single leaflets were treated and enclosed with herbivores in the laboratory and field. Another set of leaflets were treated and left to experience natural herbivory in the field. Entire plants in the field were treated with silk and enclosed with herbivores or left exposed to herbivory. In all cases, the lowest levels of herbivory occurred with spider silk treatments and, in general, silkworm silk produced intermediate levels of leaf damage. These results suggest that silk may be a mechanism for the trait-mediated impacts of spiders and that it might contribute to integrated pest management programmes.

  16. Herbivory, Predation, and Biological Control.

    Science.gov (United States)

    Murphy, Terence M.; And Others

    1992-01-01

    Authors describe a set of controlled ecosystems that can be used to demonstrate the effects of herbivory on the health and growth of a plant population and of predation on the growth of a primary consumer population. The system also shows the effectiveness of biological pest control measures in a dramatic way. The construction of the ecosystems is…

  17. Invading from the garden? A comparison of leaf herbivory for exotic and native plants in natural and ornamental settings

    Institute of Scientific and Technical Information of China (English)

    Stephen F.Matter; Adam M.Stein; Richard Stokes; Brandy S.Wilkerson; Jessica R.Brzyski; Christopher J.Harrison; Sara Hyams; Clement Loo; Jessica Loomis; Hannah R.Lubbers; Leeann Seastrum; Trevor I.Stamper

    2012-01-01

    The enemies release hypothesis proposes that exotic species can become invasive by escaping from predators and parasites in their novel environment.Agrawal et al.(Enemy release? An experiment with congeneric plant pairs and diverse above-and below-ground enemies.Ecology,86,2979-2989) proposed that areas or times in which damage to introduced species is low provide opportunities for the invasion of native habitat.We tested whether ornamental settings may provide areas with low levels of herbivory for trees and shrubs,potentially facilitating invasion success.First,we compared levels of leaf herbivory among native and exotic species in ornamental and natural settings in Cincinnati,Ohio,United States.In the second study,we compared levels of herbivory for invasive and noninvasive exotic species between natural and ornamental settings.We found lower levels of leaf damage for exotic species than for native species; however,we found no differences in the amount of leaf damage suffered in ornamental or natural settings.Our results do not provide any evidence that ornamental settings afford additional release from herbivory for exotic plant species.

  18. The effects of initial planting density on above- and below-ground biomass in a 25-year-old Fagus orientalis Lipsky plantation in Hopa, Turkey

    OpenAIRE

    Güner, Sinan; Yağcı, Volkan; Tilki, Fahrettin; Çelik, Nejat

    2010-01-01

    The aim of this study was to determine the influence of initial planting density on above- and below- ground biomass in 25 years old oriental beech stands located in Hopa, Artvin, Turkey. The initial spacings used in this study were 0.7 x 2.0 m ( high planting density) and 2.0 x 2.0 m (low planting density). To analyse the planting density response of trees of different sizes (diameter), the sample trees within each stand density class were classified into four dbh classes (dbh1, dbh2, dbh3, ...

  19. Herbivory increases diversification across insect clades.

    Science.gov (United States)

    Wiens, John J; Lapoint, Richard T; Whiteman, Noah K

    2015-09-24

    Insects contain more than half of all living species, but the causes of their remarkable diversity remain poorly understood. Many authors have suggested that herbivory has accelerated diversification in many insect clades. However, others have questioned the role of herbivory in insect diversification. Here, we test the relationships between herbivory and insect diversification across multiple scales. We find a strong, positive relationship between herbivory and diversification among insect orders. However, herbivory explains less variation in diversification within some orders (Diptera, Hemiptera) or shows no significant relationship with diversification in others (Coleoptera, Hymenoptera, Orthoptera). Thus, we support the overall importance of herbivory for insect diversification, but also show that its impacts can vary across scales and clades. In summary, our results illuminate the causes of species richness patterns in a group containing most living species, and show the importance of ecological impacts on diversification in explaining the diversity of life.

  20. Tricholoma matsutake in a natural Pinus densiflora forest: correspondence between above- and below-ground genets, association with multiple host trees and alteration of existing ectomycorrhizal communities.

    Science.gov (United States)

    Lian, Chunlan; Narimatsu, Maki; Nara, Kazuhide; Hogetsu, Taizo

    2006-01-01

    Tricholoma matsutake (matsutake) is an ectomycorrhizal (ECM) fungus that produces economically important mushrooms in Japan. Here, we use microsatellite markers to identify genets of matsutake sporocarps and below-ground ECM tips, as well as associated host genotypes of Pinus densiflora. We also studied ECM fungal community structure inside, beneath and outside the matsutake fairy rings, using morphological and internal transcribed spacer (ITS) polymorphism analysis. Based on sporocarp samples, one to four genets were found within each fairy ring, and no genetic differentiation among six sites was detected. Matsutake ECM tips were only found beneath fairy rings and corresponded with the genotypes of the above-ground sporocarps. We detected nine below-ground matsutake genets, all of which colonized multiple pine trees (three to seven trees per genet). The ECM fungal community beneath fairy rings was species-poor and significantly differed from those inside and outside the fairy rings. We conclude that matsutake genets occasionally establish from basidiospores and expand on the root systems of multiple host trees. Although matsutake mycelia suppress other ECM fungi during expansion, most of them may recover after the passage of the fairy rings.

  1. Contrasting land uses in Mediterranean agro-silvo-pastoral systems generated patchy diversity patterns of vascular plants and below-ground microorganisms.

    Science.gov (United States)

    Bagella, Simonetta; Filigheddu, Rossella; Caria, Maria Carmela; Girlanda, Mariangela; Roggero, Pier Paolo

    2014-12-01

    The aims of this paper were (i) to define how contrasting land uses affected plant biodiversity in Mediterranean agro-silvo-pastoral-systems across a gradient of disturbance regimes: cork oak forests, secondary grasslands, hay crops, grass covered vineyards, tilled vineyards; (ii) to determine whether these patterns mirrored those of below-ground microorganisms and whether the components of γ-diversity followed a similar model. The disturbance regimes affected plant assemblage composition. Species richness decreased with increasing land use intensity, the Shannon index showed the highest values in grasslands and hay crops. Plant assemblage composition patterns mirrored those of Basidiomycota and Ascomycota. Richness in Basidiomycota, denitrifying bacteria and microbial biomass showed the same trend as that observed for vascular plant richness. The Shannon index pattern of below-ground microorganisms was different from that of plants. The plant γ-diversity component model weakly mirrored those of Ascomycota. Patchy diversity patterns suggest that the maintenance of contrasting land uses associated with different productions typical of agro-silvo-pastoral-systems can guarantee the conservation of biodiversity.

  2. Recommendations to the NRC for review criteria for alternative methods of low-level radioactive waste disposal: Task 2a, Below-ground vaults

    Energy Technology Data Exchange (ETDEWEB)

    Denson, R.H.; Bennett, R.D.; Wamsley, R.M.; Bean, D.L.; Ainsworth, D.L.

    1987-12-01

    The US Army Engineer Waterways Experiment Station (WES) and the US Army Engineer Division, Huntsville (HNDED) have developed general design criteria and specific design review criteria for the below-ground vault (BGV) alternative method of low-level radioactive waste (LLW) disposal. A BGV is a reinforced concrete vault (floor, walls, and roof) placed underground below the frost line, and above the water table, surrounded by filter blanket and drainage zones and covered with a low permeability earth layer and top soil with vegetation. Eight major review criteria categories have been developed ranging from the loads imposed on the BGV structure through material quality and durability considerations. Specific design review criteria have been developed in detail for seven of the eight major categories. 59 refs., 14 figs., 2 tabs.

  3. The roots of diversity: below ground species richness and rooting distributions in a tropical forest revealed by DNA barcodes and inverse modeling.

    Directory of Open Access Journals (Sweden)

    F Andrew Jones

    Full Text Available BACKGROUND: Plants interact with each other, nutrients, and microbial communities in soils through extensive root networks. Understanding these below ground interactions has been difficult in natural systems, particularly those with high plant species diversity where morphological identification of fine roots is difficult. We combine DNA-based root identification with a DNA barcode database and above ground stem locations in a floristically diverse lowland tropical wet forest on Barro Colorado Island, Panama, where all trees and lianas >1 cm diameter have been mapped to investigate richness patterns below ground and model rooting distributions. METHODOLOGY/PRINCIPAL FINDINGS: DNA barcode loci, particularly the cpDNA locus trnH-psba, can be used to identify fine and small coarse roots to species. We recovered 33 species of roots from 117 fragments sequenced from 12 soil cores. Despite limited sampling, we recovered a high proportion of the known species in the focal hectare, representing approximately 14% of the measured woody plant richness. This high value is emphasized by the fact that we would need to sample on average 13 m(2 at the seedling layer and 45 m(2 for woody plants >1 cm diameter to obtain the same number of species above ground. Results from inverse models parameterized with the locations and sizes of adults and the species identifications of roots and sampling locations indicates a high potential for distal underground interactions among plants. CONCLUSIONS: DNA barcoding techniques coupled with modeling approaches should be broadly applicable to studying root distributions in any mapped vegetation plot. We discuss the implications of our results and outline how second-generation sequencing technology and environmental sampling can be combined to increase our understanding of how root distributions influence the potential for plant interactions in natural ecosystems.

  4. Response of two prairie forbs to repeated vole herbivory.

    Science.gov (United States)

    Sullivan, Amy T; Howe, Henry F

    2011-04-01

    Vertebrate herbivores as diverse as ungulates, geese, and rabbits preferentially feed on plants that have previously experienced herbivory. Here, we ask whether smaller grassland "cryptic consumers" such as voles (Microtus ochrogaster and M. pennsylvanicus) preferentially clip (cut stems for access to leaves or seeds) or avoid previously clipped individuals of two tallgrass prairie species (Desmanthus illinoensis and Echinacea purpurea) within a growing season. Further, we ask how these plants respond to repeated clipping within a growing season, and whether the effects of this herbivory last into the subsequent growing season. Voles preferentially clipped stems of D. illinoensis and E. purpurea plants that had been previously clipped. The exception was indiscriminant clipping of stems of E. purpurea late in the growing season when its achenes, a favorite vole food, ripened. For D. illinoensis, repeated clipping resulted in a 59% reduction in biomass, 42% lower ratio of reproductive to vegetative biomass, and 57% fewer seeds produced per plant compared with unclipped plants. These effects lasted into the following growing season in which plants were protected from voles. In contrast, the only effect of repeated clipping for E. purpurea was that the number of achenes per plant was substantially reduced by three episodes of clipping. This effect did not carry over to the next growing season. Such differences in D. illinoensis and E. purpurea response to repeated stem clipping by voles offer insights into how these small rodents can effect major changes in composition and dominance in grassland communities.

  5. Carbon transfer from photosynthesis to below ground fine root/hyphae respiration in Quercus serrata using stable carbon isotope pulse labeling

    Science.gov (United States)

    Dannoura, M.; Kominami, Y.; Takanashi, S.; Takahashi, K.

    2013-12-01

    Studying carbon allocation in trees is a key to better understand belowground carbon cycle and its response to climate change. Tracing 13C in tree and soil compartments after pulse labeling is one of powerful tool to study the fate of carbon in forest ecosystems. This experiment was conducted in Yamashiro experimental forest, Kyoto, Japan. Annual mean temperature and precipitation from 1994 to 2009 are 15.5 ° C and 1,388 mm respectively. The branch pulse labeling were done 7 times in 2011 using same branch of Quercus serrata (H:11.7 m, DBH; 33.7 cm) to see seasonal variations of carbon velocity. Whole crown labeling of Quercus serrata (H:9 m, DBH; 13.7 cm) was done in 2012 to study carbon allocation and to especially focus on belowground carbon flux until to the hyphae respiration. Pure 13CO2 (99.9%) was injected to the labeling chamber which was set to branch or crown. Then, after one hour of branch labeling and 3.5 hour for crown labeling, the chamber was opened. Trunk respiration chambers, fine root chambers and hyphae chambers were set to the target tree to trace labeled carbon in the CO2 efflux. 41 μm mesh was used to exclude ingrowth of roots into hyphae chambers. The results show that the velocity of carbon through the tree varied seasonally, with higher velocity in summer than autumn, averaging 0.47 m h-1. Half-lives of labeled carbon in autotrophic respiration were similar above and below ground during the growing season, but they were twice longer in trunk than in root in autumn. From the whole crown labeling done end of growing season, the 13CO2 signal was observed 25 hours after labeling in trunk chamber and 34-37.7 hours after labeling in fine root and hyphae respiration almost simultaneously. Half-lives of 13 was longer in trunk than below ground. Trunk respiration was still using labelled carbon during winter suggesting that winter trunk respiration is partly fueled by carbon stored in the trunk at the end of the growing season.

  6. Top-down control of herbivory by birds and bats in the canopy of temperate broad-leaved oaks (Quercus robur.

    Directory of Open Access Journals (Sweden)

    Stefan M Böhm

    Full Text Available The intensive foraging of insectivorous birds and bats is well known to reduce the density of arboreal herbivorous arthropods but quantification of collateral leaf damage remains limited for temperate forest canopies. We conducted exclusion experiments with nets in the crowns of young and mature oaks, Quercus robur, in south and central Germany to investigate the extent to which aerial vertebrates reduce herbivory through predation. We repeatedly estimated leaf damage throughout the vegetation period. Exclusion of birds and bats led to a distinct increase in arthropod herbivory, emphasizing the prominent role of vertebrate predators in controlling arthropods. Leaf damage (e.g., number of holes differed strongly between sites and was 59% higher in south Germany, where species richness of vertebrate predators and relative oak density were lower compared with our other study site in central Germany. The effects of bird and bat exclusion on herbivory were 19% greater on young than on mature trees in south Germany. Our results support previous studies that have demonstrated clear effects of insectivorous vertebrates on leaf damage through the control of herbivorous arthropods. Moreover, our comparative approach on quantification of leaf damage highlights the importance of local attributes such as tree age, forest composition and species richness of vertebrate predators for control of arthropod herbivory.

  7. Positive effects of organic farming on below-ground mutualists: large-scale comparison of mycorrhizal fungal communities in agricultural soils.

    Science.gov (United States)

    Verbruggen, Erik; Röling, Wilfred F M; Gamper, Hannes A; Kowalchuk, George A; Verhoef, Herman A; van der Heijden, Marcel G A

    2010-06-01

    *The impact of various agricultural practices on soil biodiversity and, in particular, on arbuscular mycorrhizal fungi (AMF), is still poorly understood, although AMF can provide benefit to plants and ecosystems. Here, we tested whether organic farming enhances AMF diversity and whether AMF communities from organically managed fields are more similar to those of species-rich grasslands or conventionally managed fields. *To address this issue, the AMF community composition was assessed in 26 arable fields (13 pairs of organically and conventionally managed fields) and five semi-natural grasslands, all on sandy soil. Terminal restriction fragment length polymorphism community fingerprinting was used to characterize AMF community composition. *The average number of AMF taxa was highest in grasslands (8.8), intermediate in organically managed fields (6.4) and significantly lower in conventionally managed fields (3.9). Moreover, AMF richness increased significantly with the time since conversion to organic agriculture. AMF communities of organically managed fields were also more similar to those of natural grasslands when compared with those under conventional management, and were less uniform than their conventional counterparts, as expressed by higher beta-diversity (between-site diversity). *We suggest that organic management in agro-ecosystems contributes to the restoration and maintenance of these important below-ground mutualists.

  8. Below-ground carbon allocation in mature beech and spruce trees following long-term, experimentally enhanced O{sub 3} exposure in Southern Germany

    Energy Technology Data Exchange (ETDEWEB)

    Andersen, Christian P., E-mail: Andersen.christian@epa.go [US Environmental Protection Agency, Western Ecology Division, 200 SW 35th St., Corvallis, OR 97333 (United States); Ritter, Wilma [Ecophysiology of Plants, Department of Ecology and Ecosystem Management, Technische Universitaet Muenchen, Am Hochanger 13, 85354 Freising (Germany); Gregg, Jillian [Terrestrial Ecosystems Research Associates, 200 SW 35th St., Corvallis, OR 97333 (United States); Matyssek, Rainer; Grams, Thorsten E.E. [Ecophysiology of Plants, Department of Ecology and Ecosystem Management, Technische Universitaet Muenchen, Am Hochanger 13, 85354 Freising (Germany)

    2010-08-15

    Canopies of adult European beech (Fagus sylvatica) and Norway spruce (Picea abies) were labeled with CO{sub 2} depleted in {sup 13}C to evaluate carbon allocation belowground. One-half the trees were exposed to elevated O{sub 3} for 6 yrs prior to and during the experiment. Soil-gas sampling wells were placed at 8 and 15 cm and soil CO{sub 2} was sampled during labeling in mid-late August, 2006. In beech, {delta}{sup 13}CO{sub 2} at both depths decreased approximately 50 h after labeling, reflecting rapid translocation of fixed C to roots and release through respiration. In spruce, label was detected in fine-root tissue, but there was no evidence of label in {delta}{sup 13}CO{sub 2}. The results show that C fixed in the canopy rapidly reaches respiratory pools in beech roots, and suggest that spruce may allocate very little of recently-fixed carbon into root respiration during late summer. A change in carbon allocation belowground due to long-term O{sub 3} exposure was not observed. - Below-ground carbon allocation in mature beech and spruce exposed to ozone.

  9. Integrated plant phenotypic responses to contrasting above- and below-ground resources: key roles of specific leaf area and root mass fraction.

    Science.gov (United States)

    Freschet, Grégoire T; Swart, Elferra M; Cornelissen, Johannes H C

    2015-06-01

    Plants adapt phenotypically to different conditions of light and nutrient supply, supposedly in order to achieve colimitation of these resources. Their key variable of adjustment is the ratio of leaf area to root length, which relies on plant biomass allocation and organ morphology. We recorded phenotypic differences in leaf and root mass fractions (LMF, RMF), specific leaf area (SLA) and specific root length (SRL) of 12 herbaceous species grown in factorial combinations of high/low irradiance and fertilization treatments. Leaf area and root length ratios, and their components, were influenced by nonadditive effects between light and nutrient supply, and differences in the strength of plant responses were partly explained by Ellenberg's species values representing ecological optima. Changes in allocation were critical in plant responses to nutrient availability, as the RMF contribution to changes in root length was 2.5× that of the SRL. Contrastingly, morphological adjustments (SLA rather than LMF) made up the bulk of plant response to light availability. Our results suggest largely predictable differences in responses of species and groups of species to environmental change. Nevertheless, they stress the critical need to account for adjustments in below-ground mass allocation to understand the assembly and responses of communities in changing environments.

  10. Assessment of Above- and Below-ground Competition between Sesame (Sesamume indicum L. and Pigweed (Amaranthus retroflexus and Its Effects on Sesame Yield and Yield Components

    Directory of Open Access Journals (Sweden)

    A.J Yanegh

    2013-08-01

    Full Text Available This study carried out in a factorial layout on completely randomaized block design with three replications, to evaluate the above- and below- ground competition between sesame (Sesamum indicum and pigweed (Amaranthus retroflexus, and their impacts on sesame yield and yield component. The experimental treatments were all combination of crop-weed competition (shoot competition, root competition and root-shoot competition and sesame plant densitys (1, 2 and 4 plant per pot. Plants were sown in plastic pots (24 cm diameter and 28 cm height in year 2010, at feild of Ferdowsi University of Mashhad. For study the shoot competition of sesame-pigweed, the roots were separated by plastic when the pots were filled with soil before sowing the seeds. Three weeks after emerging, shoots of plants were separated vertical barrier (30 x 70 cm for studing root competition. Results showed that competition treatments had a significant effect on seed weight per plant and yield components except 1000 seed weight. Among competition produced higher yield and yield components compared to othere treatments. However, sesame and pigweed biological weight in root-shoot competition was 2.6 and 13.7 respectively, that was higher than other competition treatments and was significant. Capsule number in main and sub branches, capsule number in plant, seed number in capsule and seed number in plant in complete competition treatment was 15, 2.58, 17.5, 43.7 and 693.89 respectively, that was higher than other treatments and differences among them was significant. Sesame density also had a significant effect on seed weight per plant and yield components. When low density were used (one plant, yield and yield components was more, therefore in one plant per pot density biological weight of sesame was 3.82 gr, and in higher densities the mentioned traits decreased significantly.

  11. Effects of the 100-year most severe El Niño driven drought on above and below ground CO2 exchanges in a seasonal tropical forest

    Science.gov (United States)

    Detto, M.; Muller-Landau, H. C.; Davies, S. J.; Rubio Ramos, V. E.

    2015-12-01

    The role of environmental drivers in regulating carbon exchanges, such as the combined effects of different meteorological and hydrological factors, are still poorly understood in many tropical forests. For example, Central American tropical forests are characterized by a distinct dry season with large atmospheric evaporative demand, driven by solar radiations and sustained winds. In contrast, during the wet seasons, cloudiness results in lower radiation inputs but higher diffuse fraction, and higher water availability. Our site, Barro Colorado Island, located in Gatun Lake, Central Panama, averages 2800 mm of annual precipitation, with a pronounced dry season in Jan-Apr. Forest age varies between 100 and >400 yr. In July 2012, an eddy covariance system was installed on a 41 m tower on the top plateau of the island. In the current year (2015) the island is experiencing the most severe El Niño driven drought on record (precipitation is measured since 1921). The eddy covariance measurements show that carbon and water fluxes are strongly influenced by hydrological conditions. Prolonged dry spells during the dry season limit both above ground fluxes (ET and GPP) and below ground processes (root and microbial activities). Light use efficiency is about 30% lower during the dry season and evapotranspiration can be as 40% below potential. These decreases in ecosystem functions are driven primarily by a combination of structural (reduction in leaf area) and physiological (stomata regulation) adaptation. Similarly, soil effluxes respond strongly to hydrological conditions. In the dry season, lower soil respiration rates are spaced out by rare rain events generating large pulses. In contrast, during the wet season, frequent rain events suppress soil CO2effluxes, because of reduced diffusivity and oxygen depletion. Diurnal variation of soil respiration also suggested a potential translocation of photosynthates from leaf to roots to increase nutrient uptake during the dry

  12. Evaluation of carbon stocks in above- and below-ground biomass in Central Africa: case study of Lesio-louna tropical rainforest of Congo

    Science.gov (United States)

    Liu, X.; Ekoungoulou, R.; Loumeto, J. J.; Ifo, S. A.; Bocko, Y. E.; Koula, F. E.

    2014-07-01

    The study was aimed to estimate the carbon stocks of above- and below-ground biomass in Lesio-louna forest of Congo. The methodology of allometric equations was used to measure the carbon stocks of Lesio-louna natural forest. We are based precisely on the model II which is also called non-destructive method or indirect method of measuring carbon stocks. While there has been use of parameters such as the DBH and wood density. The research was done with 22 circular plots each 1256 m2. In the 22 plots studied, 19 plots are in the gallery forest and three plots in the secondary forest. Also, 22 circular plots were distributed in 5 sites studies of Lesio-louna forest, including: Inkou forest island, Iboubikro, Ngoyili, Blue lake and Ngambali. So, there are two forest types (secondary forest and gallery forest) in this forest ecosystem. In the 5 sites studied, we made measurements on a total of 347 trees with 197 trees for the class of 10-30 cm diameter, 131 trees for the class of 30-60 cm diameter and 19 trees in the diameter class > 60 cm. The results show that in the whole forest, average carbon stock for the 22 plots of the study was 168.601 t C ha-1 for AGB, or 81% and 39.551 t C ha-1 for BGB, or 19%. The total carbon stocks in all the biomass was 3395.365 t C for AGB, which is 3.395365 × 10-6 Gt C and 909.689934 t C for BGB, which was 9.09689934 × 10-7 Gt C. In this forest, the carbon stock was more important in AGB compared to BGB with respectively 3395.365 t C against 909.689934 t C. Plot10 (AGB = 363.899 t C ha-1 and BGB = 85.516 t C ha-1) was the most dominant in terms of carbon quantification in Lesio-louna.

  13. Mycorrhizal associations of Salix repens L. communities in succession of dune ecosystems I Above-ground and below-ground views of ectomycorrhizal fungi in relation to soil chemistry

    NARCIS (Netherlands)

    Heijden, van der E.W.; Vries, de F.W.; Kuyper, T.W.

    2000-01-01

    The diversity of ectomycorrhizal (EcM) communities in 16 stands of Salix repens L. growing under a variety of environmental conditions was studied by repeated sampling of EcM sporocarps and ectomycorrhizas, to assess the possible correspondence between above- and below-ground views of fungal taxa. A

  14. Herbivory and Stoichiometric Feedbacks to Primary Production

    NARCIS (Netherlands)

    Krumins, Jennifer Adams; Krumins, Valdis; Forgoston, Eric; Billings, Lora; van der Putten, Wim H.

    2015-01-01

    Established theory addresses the idea that herbivory can have positive feedbacks on nutrient flow to plants. Positive feedbacks likely emerge from a greater availability of organic carbon that primes the soil by supporting nutrient turnover through consumer and especially microbially-mediated metabo

  15. Vertebral Pnomocyst

    Directory of Open Access Journals (Sweden)

    Elif Karadeli

    2015-11-01

    Full Text Available The pneumatocyst in the spine is a rare condition and is usually discovered incidentally in patients being examined for unrelated problems. Intraosseous gas collection is occured in different pathologic conditions, containing osteomyelitis with gas-forming organisms, vertebral collapse due to osteonecrosis, and postoperative and posttraumatic conditions.  

  16. Vertebral chondroblastoma

    Energy Technology Data Exchange (ETDEWEB)

    Ilaslan, Hakan; Sundaram, Murali [Department of Radiology, Mayo Clinic, 200 First Street, SW, Rochester, MN 55905 (United States); Unni, Krishnan K. [Department of Laboratory Medicine and Pathology, Mayo Clinic, 200 First Street, SW, Rochester, MN 55905 (United States)

    2003-02-01

    To determine the age distribution, gender, incidence, and imaging findings of vertebral chondroblastoma, and to compare our series with findings from case reports in the world literature.Design and patients Case records and imaging findings of nine histologically documented vertebral chondroblastomas were retrospectively reviewed for patient age, gender, vertebral column location and level, morphology, matrix, edema, soft tissue mass, spinal canal invasion, and metastases. Our findings were compared with a total of nine patients identified from previous publications in the world literature. The histologic findings in our cases was re-reviewed for diagnosis and specifically for features of calcification and secondary aneurysmal bone cyst (ABC). Clinical follow-up was requested from referring institutions. Nine of 856 chondroblastomas arose in vertebrae (incidence 1.4%; thoracic 5, lumbar 1, cervical 2, sacral 1). There were six males and three females ranging in age from 5 to 41 years (mean 28 years). Satisfactory imaging from seven patients revealed the tumor to arise from the posterior elements in four and the body in three. All tumors were expansive, six of seven were aggressive, and the spinal canal was significantly narrowed by bone or soft tissue mass in six. In one patient canal invasion was minimal. Calcification was pronounced in two and subtle in four. The sole nonaggressive-appearing tumor was heavily mineralized. Bony edema and secondary ABC were not seen on MR imaging. None of the cases had microscopic features of significant secondary ABC. Calcification, and specifically ''chicken wire'' calcification, was identified in two patients. Pulmonary metastases occurred in none. Vertebral chondroblastoma is a rare neoplasm that presents later in life than its appendicular counterpart. On imaging it is aggressive in appearance with bone destruction, soft tissue mass, and spinal canal invasion. The lesions contain variable amounts of mineral

  17. The 'Herbivory Uncertainty Principle': application in a cerrado site

    Directory of Open Access Journals (Sweden)

    CA Gadotti

    Full Text Available Researchers may alter the ecology of their studied organisms, even carrying out apparently beneficial activities, as in herbivory studies, when they may alter herbivory damage. We tested whether visit frequency altered herbivory damage, as predicted by the 'Herbivory Uncertainty Principle'. In a cerrado site, we established 80 quadrats, in which we sampled all woody individuals. We used four visit frequencies (high, medium, low, and control, quantifying, at the end of three months, herbivory damage for each species in each treatment. We did not corroborate the 'Herbivory Uncertainty Principle', since visiting frequency did not alter herbivory damage, at least when the whole plant community was taken into account. However, when we analysed each species separately, four out of 11 species presented significant differences in herbivory damage, suggesting that the researcher is not independent of its measurements. The principle could be tested in other ecological studies in which it may occur, such as those on animal behaviour, human ecology, population dynamics, and conservation.

  18. Variable effects of temperature on insect herbivory

    Directory of Open Access Journals (Sweden)

    Nathan P. Lemoine

    2014-05-01

    Full Text Available Rising temperatures can influence the top-down control of plant biomass by increasing herbivore metabolic demands. Unfortunately, we know relatively little about the effects of temperature on herbivory rates for most insect herbivores in a given community. Evolutionary history, adaptation to local environments, and dietary factors may lead to variable thermal response curves across different species. Here we characterized the effect of temperature on herbivory rates for 21 herbivore-plant pairs, encompassing 14 herbivore and 12 plant species. We show that overall consumption rates increase with temperature between 20 and 30 °C but do not increase further with increasing temperature. However, there is substantial variation in thermal responses among individual herbivore-plant pairs at the highest temperatures. Over one third of the herbivore-plant pairs showed declining consumption rates at high temperatures, while an approximately equal number showed increasing consumption rates. Such variation existed even within herbivore species, as some species exhibited idiosyncratic thermal response curves on different host plants. Thus, rising temperatures, particularly with respect to climate change, may have highly variable effects on plant-herbivore interactions and, ultimately, top-down control of plant biomass.

  19. Pyric herbivory: rewilding landscapes through the recoupling of fire and grazing.

    Science.gov (United States)

    Fuhlendorf, Samuel D; Engle, David M; Kerby, Jay; Hamilton, Robert

    2009-06-01

    Our understanding of fire and grazing is largely based on small-scale experimental studies in which treatments are uniformly applied to experimental units that are considered homogenous. Any discussion of an interaction between fire and grazing is usually based on a statistical approach that ignores the spatial and temporal interactions on complex landscapes. We propose a new focus on the ecological interaction of fire and grazing in which each disturbance is spatially and temporally dependent on the other and results in a landscape where disturbance is best described as a shifting mosaic (a landscape with patches that vary with time since disturbance) that is critical to ecological structure and function of many ecosystems. We call this spatiotemporal interaction pyric herbivory (literal interpretation means grazing driven by fire). Pyric herbivory is the spatial and temporal interaction of fire and grazing, where positive and negative feedbacks promote a shifting pattern of disturbance across the landscape. We present data we collected from the Tallgrass Prairie Preserve in the southern Great Plains of North America that demonstrates that the interaction between free-roaming bison (Bison bison) and random fires promotes heterogeneity and provides the foundation for biological diversity and ecosystem function of North American and African grasslands. This study is different from other studies of fire and grazing because the fires we examined were random and grazing animals were free to roam and select from burned and unburned patches. For ecosystems across the globe with a long history of fire and grazing, pyric herbivory with any grazing herbivore is likely more effective at restoring evolutionary disturbance patterns than a focus on restoring any large vertebrate while ignoring the interaction with fire and other disturbances.

  20. The influence of water stress on biomass and N accumulation, N partitioning between above and below ground parts and on N rhizodeposition during reproductive growth of pea (Pisum sativum L.)

    DEFF Research Database (Denmark)

    Mahieu, S.; Germont, Florent; Aveline, A.

    2009-01-01

    are estimated. Moreover, grain legume crops are largely influenced by water stress while the world area exposed to drought periods may increase in the coming years due to global warming. This work aims to quantify biomass and N accumulation, N partitioning between above and below ground parts and N...... of flowering (59 days after sowing, DAS 59), at the end of the drought period applied during pod filling (DAS 74) and at maturity (DAS 101). Water stress strongly affected pea dry weight and N accumulation. In both stressed treatments, nodule biomass and N content were reduced by about 65% in the absence...... rhizodeposition by a pea (Pisum sativum L.) when influenced by water stress. In a controlled environment, pea plants were exposed to a severe drought or not stressed, either at flowering or during pod filling. N rhizodeposition was measured using the split root method and plants were harvested at the end...

  1. Above- and Below-ground Biomass, Net Ecosystem Carbon Exchange, and Soil Respiration in a Poplar Populus deltoides Bartr.) stand : Changes after 3 years of Growth under Elevated CO2

    Science.gov (United States)

    Barron-Gafford, G. A.; Grieve, K.; Bil, K.; Kudeyarov, V.; Handley, L.; Murthy, R.

    2003-12-01

    Stands of cottonwood (Populus deltoides Bartr.) trees were grown as a coppiced system under ambient (40 Pa), twice ambient (80 Pa), and three times ambient (120 Pa) partial pressure CO2 for the past three years in the Intensively-managed Forest Mesocosm (IFM) of the Biosphere 2 Center. Over three years Net Ecosystem CO2 exchange (NECE) was measured continuously and in the third year, nine whole trees were harvested from each CO2 treatment over the growing season. Both above- and below-ground parameters were measured. Three years of growth under elevated CO2 showed the expected stimulation in foliar biomass (8.7, 11.9, and 13.1 kg for the 40, 80, and 120 Pa treatments, respectively). Rates of NECE also followed an expected increase with elevated atmospheric CO2 concentrations, with maximum CO2 uptake rates reaching 10.5, 15.6, and 19.6 μ moles m-2 s-1 in the 40, 80, and 120 Pa treatments, respectively. However, above ground woody biomass and root biomass were not much stimulated beyond 80 Pa CO2. Wood/foliage and above/below ground biomass ratios reflect this decline. Under conditions of non-limiting nutrients and water, we found consistent increases in the above/below ground biomass ratio and wood to foliage biomass ratios in the 80 compared to the 40 Pa pCO2. Woody biomass production and the above/below ground biomass ratio were lower under the 120 Pa than any other treatment. Although biomass production did not change appreciably between 80 and 120 Pa CO2 treatments, both substrate induced and in-situ soil respiration values are also significantly higher in the 120Pa treatment, though no differences were present prior to CO2 treatments (Murthy et al. 2003). The unique closed-system operation of the IFM allowed for measures of soil CO2 efflux to be measured at both the soil collar and stand scales using a box model that takes into account all inputs and outputs from the stand. In-situ soil respiration rates increased significantly with increased atmospheric CO2

  2. The role of below-ground competition during early stages of secondary succession: the case of 3-year-old Scots pine (Pinus sylvestris L.) seedlings in an abandoned grassland.

    Science.gov (United States)

    Picon-Cochard, Catherine; Coll, Lluis; Balandier, Philippe

    2006-06-01

    In abandoned or extensively managed grasslands, the mechanisms involved in pioneer tree species success are not fully explained. Resource competition among plants and microclimate modifications have been emphasised as possible mechanisms to explain variation of survivorship and growth. In this study, we evaluated a number of mechanisms that may lead to successful survival and growth of seedlings of a pioneer tree species (Pinus sylvestris) in a grass-dominated grassland. Three-year-old Scots pines were planted in an extensively managed grassland of the French Massif Central and for 2 years were either maintained in bare soil or subjected to aerial and below-ground interactions induced by grass vegetation. Soil temperatures were slightly higher in bare soil than under the grass vegetation, but not to an extent explaining pine growth differences. The tall grass canopy reduced light transmission by 77% at ground level and by 20% in the upper part of Scots pine seedlings. Grass vegetation presence also significantly decreased soil volumetric water content (Hv) and soil nitrate in spring and in summer. In these conditions, the average tree height was reduced by 5% compared to trees grown in bare soil, and plant biomass was reduced by 85%. Scots pine intrinsic water-use efficiency (A/g), measured by leaf gas-exchange, increased when Hv decreased owing to a rapid decline of stomatal conductance (g). This result was also confirmed by delta 13C analyses of needles. A summer 15N labelling of seedlings and grass vegetation confirmed the higher NO3 capture capacity of grass vegetation in comparison with Scots pine seedlings. Our results provide evidence that the seedlings' success was linked to tolerance of below-ground resource depletion (particularly water) induced by grass vegetation based on morphological and physiological plasticity as well as to resource conservation.

  3. Prairie forb response to timing of vole herbivory.

    Science.gov (United States)

    Sullivan, Amy T; Howe, Henry F

    2009-05-01

    The timing of herbivory can be an important factor in the strength and direction of plant response to herbivore damage. To determine the effect of vole herbivory timing within a growing season on tallgrass prairie forbs, we used individual plant enclosures to limit vole access to three species, Desmanthus illinoensis, Echinacea purpurea, and Heliopsis helianthoides, in an experimental restoration in northern Illinois, USA. As part of a long-term experiment, we implemented five vole access treatments in 2003: (1) vole access for the entire growing season, (2) early-season access, (3) mid-season access, (4) late-season access, and (5) no vole access. We protected all plants from herbivory in the following growing season (2004) to test whether the effects of herbivory in one growing season carried over to the next. We also tested how restoration planting design, including seeding time (June or December) and density (35 or 350 seeds/m2 of each species) affected patterns of herbivory and plant recovery. Vole access for the entire growing season was most detrimental for the growth and reproduction of all three species. In contrast, vole access for a portion of the growing season had different effects on the three species: Desmanthus growth and reproduction was negatively affected by early-season access, Echinacea reproductive output was reduced by late-season access, and Heliopsis was not affected by early-, mid-, or late-season vole access. Negative effects of continual vole access carried over to the following growing season for Desmanthus and Heliopsis, but not for Echinacea. Effects of herbivory did not carry over to the next season for Echinacea and Heliopsis when plants were accessible to voles for only part of the growing season. In contrast, Desmanthus plants exposed to early-season herbivory in one year continued to produce fewer seeds per plant after being protected from vole herbivory for a growing season. Planting density and planting season had mixed effects

  4. Herbivory Network: An international, collaborative effort to study herbivory in Arctic and alpine ecosystems

    Science.gov (United States)

    Barrio, I. C.; Hik, D. S.; Jónsdóttir, I. S.; Bueno, C. G.; Mörsdorf, M. A.; Ravolainen, V. T.

    2016-09-01

    Plant-herbivore interactions are central to the functioning of tundra ecosystems, but their outcomes vary over space and time. Accurate forecasting of ecosystem responses to ongoing environmental changes requires a better understanding of the processes responsible for this heterogeneity. To effectively address this complexity at a global scale, coordinated research efforts, including multi-site comparisons within and across disciplines, are needed. The Herbivory Network was established as a forum for researchers from Arctic and alpine regions to collaboratively investigate the multifunctional role of herbivores in these changing ecosystems. One of the priorities is to integrate sites, methodologies, and metrics used in previous work, to develop a set of common protocols and design long-term geographically-balanced, coordinated experiments. The implementation of these collaborative research efforts will also improve our understanding of traditional human-managed systems that encompass significant portions of the sub-Arctic and alpine areas worldwide. A deeper understanding of the role of herbivory in these systems under ongoing environmental changes will guide appropriate adaptive strategies to preserve their natural values and related ecosystem services.

  5. Smart Lighting Information System Design Based on Above and Below Ground Data%基于地上地下数据的智慧照明信息系统总体设计

    Institute of Scientific and Technical Information of China (English)

    孔繁宇; 崔健博; 邹同元; 褚鹏飞

    2015-01-01

    This paper describes the overall designed program of the smart lighting based on above and below ground data information.The system is based on the static data including data integration from comprehensive urban space on the ground and underground pipeline,basic geographic information and streetlights professional data.It is combined with dynamic monitoring data for multi-dimensional data fusion and application to meet business needs for urban lighting daily management of equipment monitoring,facilities management and production management.The target is to improve the management intelligence and information management level,and achieve the ultimate goal of energy and maintenance cost saving.%介绍了一种基于地上地下数据的智慧照明信息系统总体建设方案.该系统是以完备的地上城市空间与地下管线一体化数据、 基础地理信息数据和路灯专业数据为静态数据基础,结合动态监测数据进行多维数据融合与应用,满足城市照明日常管理过程中设备监控、 设施管理、 生产管理等各方面业务需求,提高城市照明日常管理的智能化、 信息化管理程度,最终达到节约能源和维护成本的最终目的.

  6. Imaging of vertebral fractures

    Directory of Open Access Journals (Sweden)

    Ananya Panda

    2014-01-01

    Full Text Available Vertebral fracture is a common clinical problem. Osteoporosis is the leading cause of non-traumatic vertebral fracture. Often, vertebral fractures are not clinically suspected due to nonspecific presentation and are overlooked during routine interpretation of radiologic investigations. Moreover, once detected, many a times the radiologist fails to convey to the clinician in a meaningful way. Hence, vertebral fractures are a constant cause of morbidity and mortality. Presence of vertebral fracture increases the chance of fracture in another vertebra and also increases the risk of subsequent hip fracture. Early detection can lead to immediate therapeutic intervention improving further the quality of life. So, in this review, we wish to present a comprehensive overview of vertebral fracture imaging along with an algorithm of evaluation of vertebral fractures.

  7. Elk herbivory alters small mammal assemblages in high elevation drainages

    Science.gov (United States)

    Parsons, Elliott W.R.; Maron, John L.; Martin, Thomas E.

    2012-01-01

    Heavy herbivory by ungulates can substantially alter habitat, but the indirect consequences of habitat modification for animal assemblages that rely on that habitat are not well studied. This is a particularly important topic given that climate change can alter plant–herbivore interactions.

  8. Testing Skills in Vertebrates

    Science.gov (United States)

    Funk, Mildred Sears; Tosto, Pat

    2007-01-01

    In this article, the authors present a project that gives students examples of basic skills that many vertebrate species develop as they grow and function in their ecosystem. These activities involve information gathering about surroundings, learning how to use objects, and tracking and searching skills. Different vertebrate species may acquire…

  9. Impact of Invertebrate Herbivory on Native Aquatic Macrophytes

    Science.gov (United States)

    2007-08-01

    be seen in the non-treated leaves (b). 5 ERDC/TN APCRP-BC-9 August 2007 a Donacia spp., and the oviposition by various species of odonates ...1999). Figure 7. Odonate eggs on the underside of a P. nodosus leaf. After emergence, the leaf will be left with numerous holes. 7 ERDC/TN...Apparently, the dry biomass differences to P. nodosus were due to insect herbivory and non-consumptive damage such as odonate eggs. Figure 8

  10. Leaf mimicry in a climbing plant protects against herbivory.

    Science.gov (United States)

    Gianoli, Ernesto; Carrasco-Urra, Fernando

    2014-05-05

    Mimicry refers to adaptive similarity between a mimic organism and a model. Mimicry in animals is rather common, whereas documented cases in plants are rare, and the associated benefits are seldom elucidated [1, 2]. We show the occurrence of leaf mimicry in a climbing plant endemic to a temperate rainforest. The woody vine Boquila trifoliolata mimics the leaves of its supporting trees in terms of size, shape, color, orientation, petiole length, and/or tip spininess. Moreover, sequential leaf mimicry occurs when a single individual vine is associated with different tree species. Leaves of unsupported vines differed from leaves of climbing plants closely associated with tree foliage but did not differ from those of vines climbing onto leafless trunks. Consistent with an herbivory-avoidance hypothesis, leaf herbivory on unsupported vines was greater than that on vines climbing on trees but was greatest on vines climbing onto leafless trunks. Thus, B. trifoliolata gains protection against herbivory not merely by climbing and thus avoiding ground herbivores [3] but also by climbing onto trees whose leaves are mimicked. Unlike earlier cases of plant mimicry or crypsis, in which the plant roughly resembles a background or color pattern [4-7] or mimics a single host [8, 9], B. trifoliolata is able to mimic several hosts.

  11. Identifying osteoporotic vertebral fracture

    OpenAIRE

    Griffith, James F.

    2015-01-01

    Osteoporosis per se is not a harmful disease. It is the sequela of osteoporosis and most particularly the occurrence of osteoporotic fracture that makes osteoporosis a serious medical condition. All of the preventative measures, investigations, treatment and research into osteoporosis have one primary goal and that is to prevent the occurrence of osteoporotic fracture. Vertebral fracture is by far and away the most prevalent osteoporotic fracture. The significance and diagnosis of vertebral f...

  12. Vertebral osteomyelitis without disc involvement

    Energy Technology Data Exchange (ETDEWEB)

    Kamani, I.; Syed, I.; Saifuddin, A. E-mail: asaifuddin@aol.com; Green, R.; MacSweeney, F

    2004-10-01

    Vertebral osteomyelitis is most commonly due to pyogenic or granulomatous infection and typically results in the combined involvement of the intervertebral disc and adjacent vertebral bodies. Non-infective causes include the related conditions of chronic recurrent multifocal osteomyelitis (CRMO) and SAPHO (synovitis, acne, pustulosis, hyperostosis, and osteitis) syndrome. Occasionally, these conditions may present purely within the vertebral body, resulting in various combinations of vertebral marrow oedema and sclerosis, destructive lesions of the vertebral body and pathological vertebral collapse, thus mimicking neoplastic disease. This review illustrates the imaging features of vertebral osteomyelitis without disc involvement, with emphasis on magnetic resonance imaging (MRI) findings.

  13. Enough is enough: the effects of symbiotic ant abundance on herbivory, growth, and reproduction in an African acacia.

    Science.gov (United States)

    Palmer, Todd M; Brody, Alison K

    2013-03-01

    Understanding how cooperative interactions evolve and persist remains a central challenge in biology. Many mutualisms are thought to be maintained by "partner fidelity feedback," in which each partner bases their investment on the benefits they receive. Yet, we know little about how benefits change as mutualists vary their investment, which is critical to understanding the balance between mutualism and antagonism in any given partnership. Using an obligate ant-plant mutualism, we manipulated the density of symbiotic acacia ants (Crematogaster mimosae) and examined how the costs and benefits to Acacia drepanolobium trees scaled with ant abundance. Benefits of ants to plants saturated with increasing ant abundance for protection from branch browsing by elephants and attack by branch galling midges, while varying linearly for protection from cerambycid beetles. In addition, the risk of catastrophic whole-tree herbivory by elephants was highest for trees with very low ant abundance. However, there was no relationship between ant abundance and herbivory by leaf-feeding invertebrates, nor by vertebrate browsers such as giraffe, steinbuck, and Grant's gazelle. Ant abundance did not significantly influence rates of branch growth on acacias, but there was a significant negative relationship between ant abundance and the number of fruits produced by host plants, suggesting that maintaining high-density ant colonies is costly. Because benefits to plants largely saturated with increasing colony size, while costs to plant reproduction increased, we suggest that ant colonies may achieve abundances that are higher than optimal for host plants. Our results highlight the conflicts of interest inherent in many mutualisms, and demonstrate the value of examining the shape of curves relating costs and benefits within these globally important interactions.

  14. Photosynthesis, growth and foliar herbivory of four Ardisia species (Myrsinaceae)

    Science.gov (United States)

    Zhao, Jin; Chen, Jin

    2011-05-01

    Ardisia elliptica is an understory shrub endemic to Southeast Asia and has become a notorious invasive plant in Florida. In this study, we determined the photosynthetic capacity of A. elliptica and phylogenetically related species under four levels of irradiations. In addition, the levels of damage from natural insect herbivory of these four species under common garden conditions were investigated. The results show that A. elliptica had the higher photosynthetic capacity and the relative growth rate (RGR) which could be attributed to its high light-saturated photosynthetic rates ( Pmax), relatively low respiratory rate ( Rd) and the increasing specific leaf area (SLA) with decreasing irradiation. A. elliptica also exhibited high phenotypic plasticity for photosynthetic traits in response to different irradiations including LSPT, Pmax and RGR. Comparing to its congeners, A. elliptica suffered consistently severe damage from natural herbivory. Our results suggest that high photosynthetic capacity and high phenotypic plasticity could enable A. elliptica become a nuisance with the absence of natural enemies in introduced habitats, especially in those disturbed environments with high-light conditions.

  15. Herbivory drives the spread of salt marsh die-off.

    Science.gov (United States)

    Bertness, Mark D; Brisson, Caitlin P; Bevil, Matthew C; Crotty, Sinead M

    2014-01-01

    Salt marsh die-off is a Western Atlantic conservation problem that has recently spread into Narragansett Bay, Rhode Island, USA. It has been hypothesized to be driven by: 1) eutrophication decreasing plant investment into belowground biomass causing plant collapse, 2) boat wakes eroding creek banks, 3) pollution or disease affecting plant health, 4) substrate hardness controlling herbivorous crab distributions and 5) trophic dysfunction releasing herbivorous crabs from predator control. To distinguish between these hypotheses we quantified these variables at 14 Narragansett Bay salt marshes where die-off intensity ranged from die-off. Herbivory explained 73% of inter-site variation in die-off and predator control of herbivores and substrate hardness also varied significantly with die-off. This suggests that salt marsh die-off is being largely driven by intense herbivory via the release of herbivorous crabs from predator control. Our results and those from other marsh systems suggest that consumer control may not simply be a factor to consider in marsh conservation, but with widespread predator depletion impacting near shore habitats globally, trophic dysfunction and runaway consumption may be the largest and most urgent management challenge for salt marsh conservation.

  16. Vertebral Fracture Prediction

    DEFF Research Database (Denmark)

    2008-01-01

    Vertebral Fracture Prediction A method of processing data derived from an image of at least part of a spine is provided for estimating the risk of a future fracture in vertebraeof the spine. Position data relating to at least four neighbouring vertebrae of the spine is processed. The curvature...

  17. Plants can benefit from herbivory: stimulatory effects of sheep saliva on growth of Leymus chinensis.

    Directory of Open Access Journals (Sweden)

    Jushan Liu

    Full Text Available BACKGROUND: Plants and herbivores can evolve beneficial interactions. Growth factors found in animal saliva are probably key factors underlying plant compensatory responses to herbivory. However, there is still a lack of knowledge about how animal saliva interacts with herbivory intensities and how saliva can mobilize photosynthate reserves in damaged plants. METHODOLOGY/PRINCIPAL FINDINGS: The study examined compensatory responses to herbivory and sheep saliva addition for the grass species Leymus chinensis in three experiments over three years. The first two experiments were conducted in a factorial design with clipping (four levels in 2006 and five in 2007 and two saliva treatment levels. The third experiment examined the mobilization and allocation of stored carbohydrates following clipping and saliva addition treatments. Animal saliva significantly increased tiller number, number of buds, and biomass, however, there was no effect on height. Furthermore, saliva effects were dependent on herbivory intensities, associated with meristem distribution within perennial grass. Animal saliva was found to accelerate hydrolyzation of fructans and accumulation of glucose and fructose. CONCLUSIONS/SIGNIFICANCE: The results demonstrated a link between saliva and the mobilization of carbohydrates following herbivory, which is an important advance in our understanding of the evolution of plant responses to herbivory. Herbivory intensity dependence of the effects of saliva stresses the significance of optimal grazing management.

  18. Predicting vertebral bone strength by vertebral static histomorphometry

    DEFF Research Database (Denmark)

    Thomsen, Jesper Skovhus; Ebbesen, Ebbe Nils; Mosekilde, Lis

    2002-01-01

    The study investigates the relationship between static histomorphometry and bone strength of human lumbar vertebral bone. The ability of vertebral histomorphometry to predict vertebral bone strength was compared with that of vertebral densitometry, and also with histomorphometry and bone strength...... of the entire vertebral bodies (L-2) were used for histomorphometry. The other iliac crest biopsies and the L-3 were destructively tested by compression. High correlation was found between BV/TV or Tb.Sp and vertebral bone strength (absolute value of r = 0.86 in both cases). Addition of Tb.Th significantly...... of improving the prediction of bone strength of the vertebral body. The correlations between BV/TV of L-2 and bone strength of L-3 were comparable with the correlation obtained by quantitative computed tomography (QCT), peripheral QCT (pQCT), and dual-energy X-ray absorptrometry (DEXA) of L-3 and bone strength...

  19. Herbivory in the soft coral Sinularia flexibilis (Alcyoniidae)

    Science.gov (United States)

    Piccinetti, Chiara C.; Ricci, Roberta; Pennesi, Chiara; Radaelli, Giuseppe; Totti, Cecilia; Norici, Alessandra; Giordano, Mario; Olivotto, Ike

    2016-03-01

    Our work provides strong support for the hypothesis that Sinularia flexibilis ingests diatoms such as Thalassiosira pseudonana. We assessed algal ingestion by S. flexibilis through estimates of algal removal, histological analyses, scanning electron microscopy observations, and gene expression determination (18S and silicon transporter 1) by real time PCR. Cell counts are strongly suggestive of algal removal by the coral; light and scanning microscopy provide qualitative evidence for the ingestion of T. pseudonana by S. flexibilis, while molecular markers did not prove to be sufficiently selective/specific to give clear results. We thus propose that previous instances of inability of corals to ingest algae are reconsidered using different technical approach, before concluding that coral herbivory is not a general feature.

  20. Effects of zooplankton herbivory on biomarker proxy records

    Science.gov (United States)

    Grice, Kliti; Klein Breteler, Wim C. M.; Schouten, Stefan; Grossi, Vincent; de Leeuw, Jan W.; Sinninghe Damsté, Jaap S.

    1998-12-01

    The stable carbon isotopic compositions of cholesterol, generally the most dominant sterol in the copepod Temora, bears the δ13C "signature" of its dietary precursor sterol when fed on Isochrysis galbana and Rhodomonas sp. The δ13C of cholesterol in the faecal pellets released from Temora longicornis fed on Rhodomonas sp. is identical to the δ13C of the sterols in the diet, indicating that no significant carbon isotopic fractionation effects occur when the copepod modifies eukaryotic precursor sterols to cholesterol. Furthermore, the ratio of long-chain alkenones and their stable carbon isotopic compositions in I. galbana were identical to those egested in faecal material. Thus Zooplankton herbivory does not invalidate the use of these alkenones as a proxy for sea surface temperature and pCO2.

  1. Selective Herbivory by an Invasive Cyprinid, the Rudd Scardinius erythrophthalmus

    Energy Technology Data Exchange (ETDEWEB)

    Kapuscinski, Kevin L [SUNY-ESF, SUNY College of Environmental Science and Forestry; John, Farrell M [SUNY-ESF, SUNY College of Environmental Science and Forestry; Stehman, Stephen V [SUNY-ESF, SUNY College of Environmental Science and Forestry; Boyer, Gregory L [SUNY-ESF, SUNY College of Environmental Science and Forestry; Fernando, Danilo D [SUNY-ESF, SUNY College of Environmental Science and Forestry; Teece, Mark A [SUNY-ESF, SUNY College of Environmental Science and Forestry; Tschaplinski, Timothy J [ORNL

    2014-01-01

    1. Herbivory by non-native animals is a problem of growing concern globally, especially for ecosystems where significant native herbivores did not previously exist or have been replaced by non-natives. The rudd (Scardinius erythrophthalmus) is an omnivorous cyprinid that has a nearly global longitudinal distribution due to human translocations, yet it is unknown whether the rudd feeds selectively among aquatic macrophyte species common to North American waters. 2. We tested a null hypothesis of non-selective feeding by rudds using five species of aquatic macrophytes: Ceratophyllum demersum, Elodea canadensis, Najas flexilis, Stuckenia pectinata, and Vallisneria americana. Four rudds were placed in 15 different 890-L tanks and presented with known quantities of each macrophyte species (each tank serving as a block in a randomized complete block design). Each macrophyte bundle was weighed on six dates during a 13 d experiment. Differences in mean percent weight remaining among macrophyte species were tested using repeated measures analysis of variance. We also quantified differences among chemical attributes of the five macrophyte species and qualitatively determined if selective feeding by rudds was related to dry matter content (DMC), percent C by dry weight (%C), percent N by dry weight (%N), and the concentrations of total soluble proteins, two organic acids (aconitic and oxalic acid), total soluble phenolic compounds (<1,000 Da), nine soluble phenolic metabolites, and total phenolic compounds. 3. Selective feeding by rudds was evident, with the order of macrophyte removal (from highest to lowest) being: N. flexilis > E. canadensis > S. pectinata > V. americana > C. demersum. Selection was positively related to %C and atomic C:N, but not DMC, %N, or concentration of total soluble proteins, contrary to the expectation that rudds would select the most nutritious plants available. The concentration of aconitic acid was greatest in N. flexilis, a preferred macrophyte

  2. The effect of insect herbivory on the growth and fitness of introduced Verbascum thapsus L

    Directory of Open Access Journals (Sweden)

    Hannah Wilbur

    2013-10-01

    Full Text Available A majority of the plant species that are introduced into new ranges either do not become established, or become naturalized yet do not attain high densities and are thus considered ecologically and economically unproblematic. The factors that limit these relatively “benign” species are not well studied. The biotic resistance hypothesis predicts that herbivores, pathogens and competition reduce growth and reproduction of individual plants and so suppress population growth of non-native species. We explored the effect of insect herbivory and surrounding vegetation on growth and fitness of the non-native biennial plant Verbascum thapsus (common mullein in Colorado, USA. Mullein is widespread in its introduced North American range, yet is infrequently considered a management concern because populations are often ephemeral and restricted to disturbed sites. To evaluate the impact of insect herbivores on mullein performance, we reduced herbivory using an insecticide treatment and compared sprayed plants to those exposed to ambient levels of herbivory. Reducing herbivory increased survival from rosette to reproduction by 7%, from 70–77%. Of plants that survived, reducing herbivory increased plant area in the first year and plant height, the length of the reproductive spike, and seed set during the second year. Reducing herbivory also had a marked effect on plant fitness, increasing seed set by 50%, from about 48,000 seeds per plant under ambient herbivory to about 98,000 per plant under reduced herbivory. Our findings also highlight that the relationship between herbivory and performance is complex. Among plants exposed to ambient herbivory, we observed a positive relationship between damage and performance, suggesting that, as predicted by the plant vigor hypothesis, insect herbivores choose the largest plants for feeding when their choice is not restricted by insecticide treatment. In contrast to the strong effects of experimentally reduced

  3. Building the Vertebrate Spine

    Science.gov (United States)

    Pourquié, Olivier

    2008-03-01

    The vertebrate body can be subdivided along the antero-posterior (AP) axis into repeated structures called segments. This periodic pattern is established during embryogenesis by the somitogenesis process. Somites are generated in a rhythmic fashion from the paraxial mesoderm and subsequently differentiate to give rise to the vertebrae and skeletal muscles of the body. Somite formation involves an oscillator-the segmentation clock-whose periodic signal is converted into the periodic array of somite boundaries. This clock drives the dynamic expression of cyclic genes in the presomitic mesoderm and requires Notch and Wnt signaling. Microarray studies of the mouse presomitic mesoderm transcriptome reveal that the segmentation clock drives the periodic expression of a large network of cyclic genes involved in cell signaling. Mutually exclusive activation of the Notch/FGF and Wnt pathways during each cycle suggests that coordinated regulation of these three pathways underlies the clock oscillator. In humans, mutations in the genes associated to the function of this oscillator such as Dll3 or Lunatic Fringe result in abnormal segmentation of the vertebral column such as those seen in congenital scoliosis. Whereas the segmentation clock is thought to set the pace of vertebrate segmentation, the translation of this pulsation into the reiterated arrangement of segment boundaries along the AP axis involves dynamic gradients of FGF and Wnt signaling. The FGF signaling gradient is established based on an unusual mechanism involving mRNA decay which provides an efficient means to couple the spatio-temporal activation of segmentation to the posterior elongation of the embryo. Another striking aspect of somite production is the strict bilateral symmetry of the process. Retinoic acid was shown to control aspects of this coordination by buffering destabilizing effects from the embryonic left-right machinery. Defects in this embryonic program controlling vertebral symmetry might lead

  4. First record of herbivory of the invasive macrophyte Hedychium coronarium J. König (Zingiberaceae)

    OpenAIRE

    Castro,Wagner Antonio Chiba de; Moitas,Marcel Loyo; Lobato,Gabriela Monteiro; Cunha-Santino,Marcela Bianchessi da; Matos,Dalva Maria da Silva

    2013-01-01

    Invasive species can cause structural and functional changes in their non-native habitats, such as changes in the trophic chain. We describe ramet herbivory of butterfly ginger, an aggressive aquatic weed in Brazil, by capybaras in a floodplain area of a Cerrado reserve. This is the first record of herbivory of H. coronarium in invaded areas. Capybaras could be using the butterfly ginger as habitat and as a food resource, which could cause changes in apparent competition between these invasiv...

  5. Disentangling fragmentation effects on herbivory in understory plants of longleaf pine savanna.

    Science.gov (United States)

    Levey, Douglas J; Caughlin, T Trevor; Brudvig, Lars A; Haddad, Nick M; Damschen, Ellen I; Tewksbury, Joshua J; Evans, Daniel M

    2016-09-01

    Habitat fragmentation affects species and their interactions through intertwined mechanisms that include changes to fragment area, shape, connectivity and distance to edge. Disentangling these pathways is a fundamental challenge of landscape ecology and will help identify ecological processes important for management of rare species or restoration of fragmented habitats. In a landscape experiment that manipulated connectivity, fragment shape, and distance to edge while holding fragment area constant, we examined how fragmentation impacts herbivory and growth of nine plant species in longleaf pine savanna. Probability of herbivory in open habitat was strongly dependent on proximity to forest edge for every species, increasing with distance to edge in six species (primarily grasses and annual forbs) and decreasing in three species (perennial forbs and a shrub). In the two species of perennial forbs, these edge effects were dependent on fragment shape; herbivory strongly decreased with distance to edge in fragments of two shapes, but not in a third shape. For most species, however, probability of herbivory was unrelated to connectivity or fragment shape. Growth was generally determined more strongly by leaf herbivory than by distance to edge, fragment shape, or connectivity. Taken together, these results demonstrate consistently strong edge effects on herbivory, one of the most important biotic factors determining plant growth and demography. Our results contrast with the generally inconsistent results of observational studies, likely because our experimental approach enabled us to tease apart landscape processes that are typically confounded.

  6. A fungal endophyte helps plants to tolerate root herbivory through changes in gibberellin and jasmonate signaling

    NARCIS (Netherlands)

    Rebeca Cosme, M.P.

    2016-01-01

    Plant–microbe mutualisms can improve plant defense, but the impact of root endophytes on below-ground herbivore interactions remains unknown. We investigated the effects of the root endophyte Piriformospora indica on interactions between rice (Oryza sativa) plants and its root herbivore rice water w

  7. Radiotherapy of vertebral hemangiomas

    Energy Technology Data Exchange (ETDEWEB)

    Sakata, Kohichi; Hareyama, Masato; Oouchi, Atushi; Sido, Mitsuo; Nagakura, Hisayasu; Tamakawa, Mituharu; Akiba, Hidenari; Morita, Kazuo [Dept. of Radiology, Sapporo Medical Univ., School of Medicine (Japan)

    1997-12-31

    Between 1975 and 1996, 14 patients (11 females, 3 males) with vertebral hemangioma received treatment with radiotherapy. Thirteen patients had a history of back pain or lumbago and 2 patients had neurological symptoms such as sensory impairment or paraplegia. The standard dose administered was 36 Gy in 18 fractions (five treatments per week). In the 13 patients with pain, this was completely or partially relieved. The condition of a man with hypesthesia of the legs deteriorated and a woman with paraplegia who was treated with decompressive laminectomy followed by radiotherapy recovered completely after irradiation. CT scan before irradiation showed thickened trabeculae as small punctate areas of sclerosis in all patients. At MR imaging before irradiation, T2-weighted MR images showed areas of high intensity in all patients and MR images demonstrated lesion enhancement. However, none of the patients who were treated successfully with radiation demonstrated any changes of the affected vertebra in the conventional radiographic films, CT scan or MR imaging, even 5 years after irradiation. Radiological imaging is indispensable for the diagnosis of vertebral hemangiomas but does not appear to be useful for evaluating the effects of radiotherapy. (orig.).

  8. Aridity increases below-ground niche breadth in grass communities

    Science.gov (United States)

    Butterfield, Bradley J.; Bradford, John B.; Munson, Seth M.; Gremer, Jennifer R.

    2017-01-01

    Aridity is an important environmental filter in the assembly of plant communities worldwide. The extent to which root traits mediate responses to aridity, and how they are coordinated with leaf traits, remains unclear. Here, we measured variation in root tissue density (RTD), specific root length (SRL), specific leaf area (SLA), and seed size within and among thirty perennial grass communities distributed along an aridity gradient spanning 190–540 mm of climatic water deficit (potential minus actual evapotranspiration). We tested the hypotheses that traits exhibited coordinated variation (1) among species, as well as (2) among communities varying in aridity, and (3) functional diversity within communities declines with increasing aridity, consistent with the “stress-dominance” hypothesis. Across communities, SLA and RTD exhibited a coordinated response to aridity, shifting toward more conservative (lower SLA, higher RTD) functional strategies with increasing aridity. The response of SRL to aridity was more idiosyncratic and was independent of variation in SLA and RTD. Contrary to the stress-dominance hypothesis, the diversity of SRL values within communities increased with aridity, while none of the other traits exhibited significant diversity responses. These results are consistent with other studies that have found SRL to be independent of an SLA–RTD axis of functional variation and suggest that the dynamic nature of soil moisture in arid environments may facilitate a wider array of resource capture strategies associated with variation in SRL.

  9. [Growth, survival and herbivory of seedlings in Brosimum alicastrum (Moraceae), a species from the Neotropical undergrowth].

    Science.gov (United States)

    Ballina-Gómez, H S; Iriarte-Vivar, S; Orellana, R; Santiago, L S

    2008-12-01

    Growth responses, survival, and herbivory, on seedlings of Brosimum alicastrum were studied in a neotropical Mexican forest. We selected 122 seedlings and divided them into three groups assigned to defoliation treatments: control or 0 (n=21), 50 (n=51) and 90% (n=50). Every 4 months during two years we measured seedling growth (in terms of relative growth rate in biomass, leaf area growth, produced leaves and height growth) and survival. In addition, we evaluated every 12 months pathogen damage and insect herbivory using a 2 mm(-2) grid. Separately, we estimated mammal herbivory in 3-month old seedlings that were selected within a plot of 500 m x 10 m (N=1095). Pathogen damage and insect herbivory were evaluated within the same plot in 113 seedlings. We found that 50% defoliated seedlings showed compensatory responses in all growth parameters. Relative growth rate and height growth also had a compensatory response in seedlings at 90% defoliation. Relative growth rate and leaf area growth gradually decreased with time although height growth seedling showed an opposite pattern. Leaves produced were not affected by time. Estimated seedling survival probability increased with defoliation to a maximum of 97%, decreasing at 24 month to 37%. Mammal herbivory was more frequent and severe than herbivory caused by pathogens and insects. In some cases, mammal herbivory produced total defoliation. Compensatory growth in leaf area growth, produced leaves and height growth seedling suggest a synergic compensatory mechanism expressed in a whole-plant growth biomass (relative growth rate). Compensation and survival results suggest trade-offs at the leaf level, such as leaf area growth and produced leaves versus chemical defenses, respectively.

  10. Spermatogenesis in nonmammalian vertebrates.

    Science.gov (United States)

    Pudney, J

    1995-12-15

    Spermatogenesis appears to be a fairly conserved process throughout the vertebrate series. Thus, spermatogonia develop into spermatocytes that undergo meiosis to produce spermatids which enter spermiogenesis where they undergo a morphological transformation into spermatozoa. There is, however, variation amongst the vertebrates in how germ cell development and maturation is accomplished. This difference can be broadly divided into two distinct patterns, one present in anamniotes (fish, amphibia) and the other in amniotes (reptiles, birds, mammals). For anamniotes, spermatogenesis occurs in spermatocysts (cysts) which for most species develop within seminiferous lobules. Cysts are produced when a Sertoli cell becomes associated with a primary spermatogonium. Mitotic divisions of the primary spermatogonium produce a cohort of secondary spermatogonia that are enclosed by the Sertoli cell which forms the wall of the cyst. With spermatogenic progression a clone of isogeneic spermatozoa is produced which are released, by rupture of the cyst, into the lumen of the seminiferous lobule. Following spermiation, the Sertoli cell degenerates. For anamniotes, therefore, there is no permanent germinal epithelium since spermatocysts have to be replaced during successive breeding seasons. By contrast, spermatogenesis in amniotes does not occur in cysts but in seminiferous tubules that possess a permanent population of Sertoli cells and spermatogonia which act as a germ cell reservoir for succeeding bouts of spermatogenic activity. There is, in general, a greater variation in the organization of the testis and pattern of spermatogenesis in the anamniotes compared to amniotes. This is primarily due to the fact there is more reproductive diversity in anamniotes ranging from a relatively unspecialized condition where gametes are simply released into the aqueous environment to highly specialized strategies involving internal fertilization. These differences are obviously reflected in the

  11. Vertebral contour in spondylolisthesis

    Energy Technology Data Exchange (ETDEWEB)

    Lee, J. S.; Rho, J. C.; Park, J. H.; Choi, H. Y.; Kim, B. K. [Wallace memorial Baptist Hospital, Busan (Korea, Republic of)

    1981-09-15

    The defect in the pars interarticularis of spondylolisthesis may be dependent on contributing factors related to trauma and stress to which the neural arch is subjected, superimposed on a hereditary diasthesis. Posterior wedging of 5th lumber vertebral body in lumbosacral spondylolisthesis together with the degree of slip have been measured. The average wedging in spondylolisthesis is significantly greater than patient without this condition, and forms a characteristic radiological sign. The degree of wedging and slip show a statistically valid correlation. The diagnosis of spondylolisthesis is becoming more prevalent as the complexity of our society result in the increasing use of roentgenography of the lumbar spine. Isolated lateral deviation and rotation of spinous process seen in anteroposterior radiographs of the lumbar spine seems to be associated with pathology in the pars interarticularis.

  12. Systematic analysis of rice (Oryza sativa) metabolic responses to herbivory.

    Science.gov (United States)

    Alamgir, Kabir Md; Hojo, Yuko; Christeller, John T; Fukumoto, Kaori; Isshiki, Ryutaro; Shinya, Tomonori; Baldwin, Ian T; Galis, Ivan

    2016-02-01

    Plants defend against attack from herbivores by direct and indirect defence mechanisms mediated by the accumulation of phytoalexins and release of volatile signals, respectively. While the defensive arsenals of some plants, such as tobacco and Arabidopsis are well known, most of rice's (Oryza sativa) defence metabolites and their effectiveness against herbivores remain uncharacterized. Here, we used a non-biassed metabolomics approach to identify many novel herbivory-regulated metabolic signatures in rice. Most were up-regulated by herbivore attack while only a few were suppressed. Two of the most prominent up-regulated signatures were characterized as phenolamides (PAs), p-coumaroylputrescine and feruloylputrescine. PAs accumulated in response to attack by both chewing insects, i.e. feeding of the lawn armyworm (Spodoptera mauritia) and the rice skipper (Parnara guttata) larvae, and the attack of the sucking insect, the brown planthopper (Nilaparvata lugens, BPH). In bioassays, BPH insects feeding on 15% sugar solution containing p-coumaroylputrescine or feruloylputrescine, at concentrations similar to those elicited by heavy BPH attack in rice, had a higher mortality compared to those feeding on sugar diet alone. Our results highlight PAs as a rapidly expanding new group of plant defence metabolites that are elicited by herbivore attack, and deter herbivores in rice and other plants.

  13. Chemical ecology of vertebrate carrion

    Science.gov (United States)

    Vertebrate carrion is a nutrient-rich, ephemeral resource that is utilized by many different organisms ranging from vertebrate and invertebrate scavengers to microbes. The organisms that consume carrion play an important ecological role, as decomposition is vital to ecosystem function. Without the...

  14. Above- and belowground herbivory jointly impact defense and seed dispersal traits in Taraxacum officinale.

    Science.gov (United States)

    de la Peña, Eduardo; Bonte, Dries

    2014-08-01

    Plants are able to cope with herbivores by inducing defensive traits or growth responses that allow them to reduce or avoid the impact of herbivores. Since above- and belowground herbivores differ substantially in life-history traits, for example feeding types, and their spatial distribution, it is likely that they induce different responses in plants. Moreover, strong interactive effects on defense and plant growth are expected when above- and belowground herbivores are jointly present. The strengths and directions of these responses have been scarcely addressed in the literature. Using Taraxacum officinale, the root-feeding nematode Meloidogyne hapla and the locust Schistocerca gregaria as a model species, we examined to what degree above- and belowground herbivory affect (1) plant growth responses, (2) the induction of plant defensive traits, that is, leaf trichomes, and (3) changes in dispersal-related seed traits and seed germination. We compared the performance of plants originating from different populations to address whether plant responses are conserved across putative different genotypes. Overall, aboveground herbivory resulted in increased plant biomass. Root herbivory had no effect on plant growth. Plants exposed to the two herbivores showed fewer leaf trichomes than plants challenged only by one herbivore and consequently experienced greater aboveground herbivory. In addition, herbivory had effects that reached beyond the individual plant by modifying seed morphology, producing seeds with longer pappus, and germination success.

  15. Responses of insect herbivores and herbivory to habitat fragmentation: a hierarchical meta-analysis.

    Science.gov (United States)

    Rossetti, María Rosa; Tscharntke, Teja; Aguilar, Ramiro; Batáry, Péter

    2017-02-01

    Loss and fragmentation of natural habitats can lead to alterations of plant-animal interactions and ecosystems functioning. Insect herbivory, an important antagonistic interaction is expected to be influenced by habitat fragmentation through direct negative effects on herbivore community richness and indirect positive effects due to losses of natural enemies. Plant community changes with habitat fragmentation added to the indirect effects but with little predictable impact. Here, we evaluated habitat fragmentation effects on both herbivory and herbivore diversity, using novel hierarchical meta-analyses. Across 89 studies, we found a negative effect of habitat fragmentation on abundance and species richness of herbivores, but only a non-significant trend on herbivory. Reduced area and increased isolation of remaining fragments yielded the strongest effect on abundance and species richness, while specialist herbivores were the most vulnerable to habitat fragmentation. These fragmentation effects were more pronounced in studies with large spatial extent. The strong reduction in herbivore diversity, but not herbivory, indicates how important common generalist species can be in maintaining herbivory as a major ecosystem process.

  16. Comparative anatomy: all vertebrates do have vertebrae.

    Science.gov (United States)

    Janvier, Philippe

    2011-09-13

    In contrast to lampreys and jawed vertebrates, hagfishes were thought to lack vertebrae. Now, long overlooked vertebral rudiments have been analysed in hagfish, suggesting that vertebrae existed in the last common ancestor of all vertebrates.

  17. Long-term habitat selection and chronic root herbivory: explaining the relationship between periodical cicada density and tree growth.

    Science.gov (United States)

    Yang, Louie H; Karban, Richard

    2009-01-01

    Periodical cicadas (Magicicada spp.) are insect herbivores that feed on host tree roots, but their distribution among hosts is determined largely by the oviposition of female cicadas in the previous generation. A pattern of decreasing tree growth rates with increasing cicada densities is predicted when considering the costs of chronic root herbivory, but the opposite pattern is expected when considering adaptive habitat selection. Here, we report observations indicating that the relationship between periodical cicada densities and host tree growth rates is hump shaped. We suggest that both herbivory and habitat selection are likely to be key processes explaining this pattern, resulting in regions of positive and negative correlation. These results suggest that the effects of cicada herbivory are most apparent at relatively high cicada densities, while habitat selection tends to distribute cicada herbivory on host trees that are able to compensate for cicada root herbivory up to threshold cicada densities.

  18. Termites, vertebrate herbivores, and the fruiting success of Acacia drepanolobium.

    Science.gov (United States)

    Brody, Alison K; Palmer, Todd M; Fox-Dobbs, Kena; Doak, Dan F

    2010-02-01

    In African savannas, vertebrate herbivores are often identified as key determinants of plant growth, survivorship, and reproduction. However, plant reproduction is likely to be the product of responses to a suite of abiotic and biotic factors, including nutrient availability and interactions with antagonists and mutualists. In a relatively simple system, we examined the role of termites (which act as ecosystem engineers--modifying physical habitat and creating islands of high soil fertility), vertebrate herbivores, and symbiotic ants, on the fruiting success of a dominant plant, Acacia drepanolobium, in East African savannas. Using observational data, large-scale experimental manipulations, and analysis of foliar N, we found that Acacia drepanolobium trees growing at the edge of termite mounds were more likely to reproduce than those growing farther away, in off-mound soils. Although vertebrate herbivores preferentially used termite mounds as demonstrated by dung deposits, long-term exclusion of mammalian grazers did not significantly reduce A. drepanolobium fruit production. Leaf N was significantly greater in trees growing next to mounds than in those growing farther away, and this pattern was unaffected by exclusion of vertebrates. Thus, soil enrichment by termites, rather than through dung and urine deposition by large herbivores, is of primary importance to fruit production near mounds. Across all mound-herbivore treatment combinations, trees that harbored Crematogaster sjostedti were more likely to fruit than those that harbored one of the other three ant species. Although C. sjostedti is less aggressive than the other ants, it tends to inhabit large, old trees near termite mounds which are more likely to fruit than smaller ones. Termites play a key role in generating patches of nutrient-rich habitat important to the reproductive success of A. drepanolobium in East African savannas. Enhanced nutrient acquisition from termite mounds appears to allow plants to

  19. Grassland productivity in response to nutrient additions and herbivory is scale-dependent

    Directory of Open Access Journals (Sweden)

    Erica A.H. Smithwick

    2016-12-01

    Full Text Available Vegetation response to nutrient addition can vary across space, yet studies that explicitly incorporate spatial pattern into experimental approaches are rare. To explore whether there are unique spatial scales (grains at which grass response to nutrients and herbivory is best expressed, we imposed a large (∼3.75 ha experiment in a South African coastal grassland ecosystem. In two of six 60 × 60 m grassland plots, we imposed a scaled sampling design in which fertilizer was added in replicated sub-plots (1 × 1 m, 2 × 2 m, and 4 × 4 m. The remaining plots either received no additions or were fertilized evenly across the entire area. Three of the six plots were fenced to exclude herbivory. We calculated empirical semivariograms for all plots one year following nutrient additions to determine whether the scale of grass response (biomass and nutrient concentrations corresponded to the scale of the sub-plot additions and compared these results to reference plots (unfertilized or unscaled and to plots with and without herbivory. We compared empirical semivariogram parameters to parameters from semivariograms derived from a set of simulated landscapes (neutral models. Empirical semivariograms showed spatial structure in plots that received multi-scaled nutrient additions, particularly at the 2 × 2 m grain. The level of biomass response was predicted by foliar P concentration and, to a lesser extent, N, with the treatment effect of herbivory having a minimal influence. Neutral models confirmed the length scale of the biomass response and indicated few differences due to herbivory. Overall, we conclude that interpretation of nutrient limitation in grasslands is dependent on the grain used to measure grass response and that herbivory had a secondary effect.

  20. Grassland productivity in response to nutrient additions and herbivory is scale-dependent

    Science.gov (United States)

    Baldwin, Douglas C.; Naithani, Kusum J.

    2016-01-01

    Vegetation response to nutrient addition can vary across space, yet studies that explicitly incorporate spatial pattern into experimental approaches are rare. To explore whether there are unique spatial scales (grains) at which grass response to nutrients and herbivory is best expressed, we imposed a large (∼3.75 ha) experiment in a South African coastal grassland ecosystem. In two of six 60 × 60 m grassland plots, we imposed a scaled sampling design in which fertilizer was added in replicated sub-plots (1 × 1 m, 2 × 2 m, and 4 × 4 m). The remaining plots either received no additions or were fertilized evenly across the entire area. Three of the six plots were fenced to exclude herbivory. We calculated empirical semivariograms for all plots one year following nutrient additions to determine whether the scale of grass response (biomass and nutrient concentrations) corresponded to the scale of the sub-plot additions and compared these results to reference plots (unfertilized or unscaled) and to plots with and without herbivory. We compared empirical semivariogram parameters to parameters from semivariograms derived from a set of simulated landscapes (neutral models). Empirical semivariograms showed spatial structure in plots that received multi-scaled nutrient additions, particularly at the 2 × 2 m grain. The level of biomass response was predicted by foliar P concentration and, to a lesser extent, N, with the treatment effect of herbivory having a minimal influence. Neutral models confirmed the length scale of the biomass response and indicated few differences due to herbivory. Overall, we conclude that interpretation of nutrient limitation in grasslands is dependent on the grain used to measure grass response and that herbivory had a secondary effect. PMID:27920956

  1. Sex-related differences in reproductive allocation, growth, defense and herbivory in three dioecious neotropical palms.

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    Verónica Cepeda-Cornejo

    Full Text Available BACKGROUND: Frequently, in dioecious plants, female plants allocate more resources to reproduction than male plants. Therefore it is expected that asymmetrical allocation to reproduction may lead to a reproduction-growth tradeoff, whereby female plants grow less than male plants, but invest more in defenses and thus experience lower herbivory than male plants. METHODOLOGY/PRINCIPAL FINDINGS: We tested these expectations by comparing resource allocation to reproduction, growth and defense and its consequences on herbivory in three sympatric dioecious Chamaedorea palms (C. alternans, C. pinnatifrons and C. ernesti-augusti using a pair-wise design (replicated male/female neighboring plants in a Mexican tropical rain forest. Our findings support the predictions. Biomass allocation to reproduction in C. pinnatifrons was 3-times higher in female than male plants, consistent with what is known in C. alternans and C. ernesti-augusti. Growth (height and leaf production rate and biomass production was higher in male plants of all three species. Female plants of the three species had traits that suggest greater investment in defense, as they had 4-16% tougher leaves, and 8-18% higher total phenolic compounds concentration. Accordingly, female plants sustained 53-78% lower standing herbivory and 49-87% lower herbivory rates than male plants. CONCLUSIONS/SIGNIFICANCE: Our results suggests that resource allocation to reproduction in the studied palms is more costly to female plants and this leads to predictable intersexual differences in growth, defense and herbivory. We conclude that resource allocation to reproduction in plants can have important consequences that influence their interaction with herbivores. Since herbivory is recognized as an important selective force in plants, these results are of significance to our understanding of plant defense evolution.

  2. Simulated herbivory does not constrain phenotypic plasticity to shade through ontogeny in a relict tree.

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    Pardo, A; García, F M; Valladares, F; Pulido, F

    2016-07-01

    Ecological limits to phenotypic plasticity (PP), induced by simultaneous biotic and abiotic factors, can prevent organisms from exhibiting optimal plasticity, and in turn lead to decreased fitness. Herbivory is an important biotic stressor and may limit plant functional responses to challenging environmental conditions such as shading. In this study we investigated whether plant functional responses and PP to shade are constrained by herbivory, and whether such constraints are due to direct effects based on resource limitation by considering ontogeny. We used as a model system the relict tree Prunus lusitanica and implemented an indoor experiment to quantify the response of saplings of different ages to shade and herbivory. We measured five functional traits and quantitatively calculated PP. Results showed that herbivory did not constrain functional responses or PP to shade except for shoot:root ratio (SR), which, despite showing a high PP in damaged saplings, decreased under shade instead of increasing. Damaged saplings of older age did not exhibit reduced constraints on functional responses to shade and generally presented a lower PP than damaged saplings of younger age. Our findings suggest that herbivory-mediated constraints on plant plasticity to shade may not be as widespread as previously thought. Nonetheless, the negative effect of herbivory on SR plastic expression to shade could be detrimental for plant fitness. Finally, our results suggest a secondary role of direct effects (resource-based) on P. lusitanica plasticity limitation. Further studies should quantify plant resources in order to gain a better understanding of this seldom-explored subject.

  3. Impairment of leaf photosynthesis after insect herbivory or mechanical injury on common milkweed, Asclepias syriaca.

    Science.gov (United States)

    Delaney, K J; Haile, F J; Peterson, R K D; Higley, L G

    2008-10-01

    Insect herbivory has variable consequences on plant physiology, growth, and reproduction. In some plants, herbivory reduces photosynthetic rate (Pn) activity on remaining tissue of injured leaves. We sought to better understand the influence of leaf injury on Pn of common milkweed, Asclepias syriaca (Asclepiadaceae), leaves. Initially, we tested whether Pn reductions occurred after insect herbivory or mechanical injury. We also (1) examined the duration of photosynthetic recovery, (2) compared mechanical injury with insect herbivory, (3) studied the relationship between leaf Pn with leaf injury intensity, and (4) considered uninjured leaf compensatory Pn responses neighboring an injured leaf. Leaf Pn was significantly reduced on mechanically injured or insect-fed leaves in all reported experiments except one, so some factor(s) (cardiac glycoside induction, reproductive investment, and water stress) likely interacts with leaf injury to influence whether Pn impairment occurs. Milkweed tussock moth larval herbivory, Euchaetes egle L. (Arctiidae), impaired leaf Pn more severely than mechanical injury in one experiment. Duration of Pn impairment lasted > 5 d to indicate high leaf Pn sensitivity to injury, but Pn recovery occurred within 13 d in one experiment. The degree of Pn reduction was more severe from E. egle herbivory than similar levels of mechanical tissue removal. Negative linear relationships characterized leaf Pn with percentage tissue loss from single E. egle-fed leaves and mechanically injured leaves and suggested that the signal to trigger leaf Pn impairment on remaining tissue of an injured leaf was amplified by additional tissue loss. Finally, neighboring uninjured leaves to an E. egle-fed leaf had a small (approximately 10%) degree of compensatory Pn to partly offset tissue loss and injured leaf Pn impairment.

  4. The roots of defense: plant resistance and tolerance to belowground herbivory.

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    Sean M Watts

    Full Text Available BACKGROUND: There is conclusive evidence that there are fitness costs of plant defense and that herbivores can drive selection for defense. However, most work has focused on above-ground interactions, even though belowground herbivory may have greater impacts on individual plants than above-ground herbivory. Given the role of belowground plant structures in resource acquisition and storage, research on belowground herbivores has much to contribute to theories on the evolution of plant defense. Pocket gophers (Geomyidae provide an excellent opportunity to study root herbivory. These subterranean rodents spend their entire lives belowground and specialize on consuming belowground plant parts. METHODOLOGY AND PRINCIPAL FINDINGS: We compared the root defenses of native forbs from mainland populations (with a history of gopher herbivory to island populations (free from gophers for up to 500,000 years. Defense includes both resistance against herbivores and tolerance of herbivore damage. We used three approaches to compare these traits in island and mainland populations of two native California forbs: 1 Eschscholzia californica populations were assayed to compare alkaloid deterrents, 2 captive gophers were used to test the palatability of E. californica roots and 3 simulated root herbivory assessed tolerance to root damage in Deinandra fasciculata and E. californica. Mainland forms of E. californica contained 2.5 times greater concentration of alkaloids and were less palatable to gophers than island forms. Mainland forms of D. fasciculata and, to a lesser extent, E. californica were also more tolerant of root damage than island conspecifics. Interestingly, undamaged island individuals of D. fasciculata produced significantly more fruit than either damaged or undamaged mainland individuals. CONCLUSIONS AND SIGNIFICANCE: These results suggest that mainland plants are effective at deterring and tolerating pocket gopher herbivory. Results also suggest

  5. Genetic diversity increases insect herbivory on oak saplings.

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    Bastien Castagneyrol

    Full Text Available A growing body of evidence from community genetics studies suggests that ecosystem functions supported by plant species richness can also be provided by genetic diversity within plant species. This is not yet true for the diversity-resistance relationship as it is still unclear whether damage by insect herbivores responds to genetic diversity in host plant populations. We developed a manipulative field experiment based on a synthetic community approach, with 15 mixtures of one to four oak (Quercus robur half-sib families. We quantified genetic diversity at the plot level by genotyping all oak saplings and assessed overall damage caused by ectophagous and endophagous herbivores along a gradient of increasing genetic diversity. Damage due to ectophagous herbivores increased with the genetic diversity in oak sapling populations as a result of higher levels of damage in mixtures than in monocultures for all families (complementarity effect rather than because of the presence of more susceptible oak genotypes in mixtures (selection effect. Assemblages of different oak genotypes would benefit polyphagous herbivores via improved host patch location, spill over among neighbouring saplings and diet mixing. By contrast, genetic diversity was a poor predictor of the abundance of endophagous herbivores, which increased with individual sapling apparency. Plant genetic diversity may not provide sufficient functional contrast to prevent tree sapling colonization by specialist herbivores while enhancing the foraging of generalist herbivores. Long term studies are nevertheless required to test whether the effect of genetic diversity on herbivory change with the ontogeny of trees and local adaptation of specialist herbivores.

  6. Microzooplankton herbivory and community structure in the Amundsen Sea, Antarctica

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    Yang, Eun Jin; Jiang, Yong; Lee, SangHoon

    2016-01-01

    We examined microzooplankton abundance, community structure, and grazing impact on phytoplankton in the Amundsen Sea, Western Antarctica, during the early austral summer from December 2010 to January 2011. Our study area was divided into three regions based on topography, hydrographic properties, and trophic conditions: (1) the Oceanic Zone (OZ), with free sea ice and low phytoplankton biomass dominated by diatoms; (2) the Sea Ice Zone (SIZ), covered by heavy sea ice with colder water, lower salinity, and dominated by diatoms; and (3) the Amundsen Sea Polynya (ASP), with high phytoplankton biomass dominated by Phaeocystis antarctica. Microzooplankton biomass and communities associated with phytoplankton biomass and composition varied among regions. Heterotrophic dinoflagellates (HDF) were the most significant grazers in the ASP and OZ, whereas ciliates co-dominated with HDF in the SIZ. Microzooplankton grazing impact is significant in our study area, particularly in the ASP, and consumed 55.4-107.6% of phytoplankton production (average 77.3%), with grazing impact increasing with prey and grazer biomass. This result implies that a significant proportion of the phytoplankton production is not removed by sinking or other grazers but grazed by microzooplankton. Compared with diatom-based systems, Phaeocystis-based production would be largely remineralized and/or channeled through the microbial food web through microzooplankton grazing. In these waters the major herbivorous fate of phytoplankton is likely mediated by the microzooplankton population. Our study confirms the importance of herbivorous protists in the planktonic ecosystems of high latitudes. In conclusion, microzooplankton herbivory may be a driving force controlling phytoplankton growth in early summer in the Amundsen Sea, particularly in the ASP.

  7. Lymphatic regulation in nonmammalian vertebrates.

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    Hedrick, Michael S; Hillman, Stanley S; Drewes, Robert C; Withers, Philip C

    2013-08-01

    All vertebrate animals share in common the production of lymph through net capillary filtration from their closed circulatory system into their tissues. The balance of forces responsible for net capillary filtration and lymph formation is described by the Starling equation, but additional factors such as vascular and interstitial compliance, which vary markedly among vertebrates, also have a significant impact on rates of lymph formation. Why vertebrates show extreme variability in rates of lymph formation and how nonmammalian vertebrates maintain plasma volume homeostasis is unclear. This gap hampers our understanding of the evolution of the lymphatic system and its interaction with the cardiovascular system. The evolutionary origin of the vertebrate lymphatic system is not clear, but recent advances suggest common developmental factors for lymphangiogenesis in teleost fishes, amphibians, and mammals with some significant changes in the water-land transition. The lymphatic system of anuran amphibians is characterized by large lymphatic sacs and two pairs of lymph hearts that return lymph into the venous circulation but no lymph vessels per se. The lymphatic systems of reptiles and some birds have lymph hearts, and both groups have extensive lymph vessels, but their functional role in both lymph movement and plasma volume homeostasis is almost completely unknown. The purpose of this review is to present an evolutionary perspective in how different vertebrates have solved the common problem of the inevitable formation of lymph from their closed circulatory systems and to point out the many gaps in our knowledge of this evolutionary progression.

  8. Latitudinal variation in resistance and tolerance to herbivory in the perennial herb Lythrum salicaria is related to intensity of herbivory and plant phenology.

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    Lehndal, L; Ågren, J

    2015-03-01

    Both the length of the growing season and the intensity of herbivory often vary along climatic gradients, which may result in divergent selection on plant phenology, and on resistance and tolerance to herbivory. In Sweden, the length of the growing season and the number of insect herbivore species feeding on the perennial herb Lythrum salicaria decrease from south to north. Previous common-garden experiments have shown that northern L. salicaria populations develop aboveground shoots earlier in the summer and finish growth before southern populations do. We tested the hypotheses that resistance and tolerance to damage vary with latitude in L. salicaria and are positively related to the intensity of herbivory in natural populations. We quantified resistance and tolerance of populations sampled along a latitudinal gradient by scoring damage from natural herbivores and fitness in a common-garden experiment in the field and by documenting oviposition and feeding preference by specialist leaf beetles in a glasshouse experiment. Plant resistance decreased with latitude of origin, whereas plant tolerance increased. Oviposition and feeding preference in the glasshouse and leaf damage in the common-garden experiment were negatively related to damage in the source populations. The latitudinal variation in resistance was thus consistent with reduced selection from herbivores towards the northern range margin of L. salicaria. Variation in tolerance may be related to differences in the timing of damage in relation to the seasonal pattern of plant growth, as northern genotypes have developed further than southern have when herbivores emerge in early summer.

  9. Herbivory by a Phloem-feeding insect inhibits floral volatile production.

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    Martin Pareja

    Full Text Available There is extensive knowledge on the effects of insect herbivory on volatile emission from vegetative tissue, but little is known about its impact on floral volatiles. We show that herbivory by phloem-feeding aphids inhibits floral volatile emission in white mustard Sinapis alba measured by gas chromatographic analysis of headspace volatiles. The effect of the Brassica specialist aphid Lipaphis erysimi was stronger than the generalist aphid Myzus persicae and feeding by chewing larvae of the moth Plutella xylostella caused no reduction in floral volatile emission. Field observations showed no effect of L. erysimi-mediated floral volatile emission on the total number of flower visits by pollinators. Olfactory bioassays suggested that although two aphid natural enemies could detect aphid inhibition of floral volatiles, their olfactory orientation to infested plants was not disrupted. This is the first demonstration that phloem-feeding herbivory can affect floral volatile emission, and that the outcome of interaction between herbivory and floral chemistry may differ depending on the herbivore's feeding mode and degree of specialisation. The findings provide new insights into interactions between insect herbivores and plant chemistry.

  10. Plant defense, herbivory, and the growth of Cordia alliodora trees and their symbiotic Azteca ant colonies.

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    Pringle, Elizabeth G; Dirzo, Rodolfo; Gordon, Deborah M

    2012-11-01

    The effects of herbivory on plant fitness are integrated over a plant's lifetime, mediated by ontogenetic changes in plant defense, tolerance, and herbivore pressure. In symbiotic ant-plant mutualisms, plants provide nesting space and food for ants, and ants defend plants against herbivores. The benefit to the plant of sustaining the growth of symbiotic ant colonies depends on whether defense by the growing ant colony outpaces the plant's growth in defendable area and associated herbivore pressure. These relationships were investigated in the symbiotic mutualism between Cordia alliodora trees and Azteca pittieri ants in a Mexican tropical dry forest. As ant colonies grew, worker production remained constant relative to ant-colony size. As trees grew, leaf production increased relative to tree size. Moreover, larger trees hosted lower densities of ants, suggesting that ant-colony growth did not keep pace with tree growth. On leaves with ants experimentally excluded, herbivory per unit leaf area increased exponentially with tree size, indicating that larger trees experienced higher herbivore pressure per leaf area than smaller trees. Even with ant defense, herbivory increased with tree size. Therefore, although larger trees had larger ant colonies, ant density was lower in larger trees, and the ant colonies did not provide sufficient defense to compensate for the higher herbivore pressure in larger trees. These results suggest that in this system the tree can decrease herbivory by promoting ant-colony growth, i.e., sustaining space and food investment in ants, as long as the tree continues to grow.

  11. The ghost of herbivory past: slow defence relaxation in the chlorophyte Scenedesmus obliquus

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    Jacobus VIJVERBERG

    2009-08-01

    Full Text Available The freshwater chlorophyte Scenedesmus obliquus (Turpin Kützing produces colonies as an inducible defence against herbivores. We investigated the dynamics of Scenedesmus colony formation and disintegration in response to the density of the herbivorous rotifer Brachionus calyciflorus in large-scale mesocosms. Additional bioassays were performed to investigate Scenedesmus colony disintegration under different light regimes. In the mesocosm experiment, colony formation took place rapidly, but relaxation towards the initial size took relatively long (>10 d after cessation of herbivory. In the bioassays, in the absence of infochemicals, colonies disintegrated almost immediately in the dark (1-1.5 d, within 4 d under a photoperiod of 16:8 (L:D and between 8 and 12 days under full light. Colony disintegration times in the mesocosm experiment were substantially longer as compared to treatments with the same photoperiod (L:D 16:8 in the bioassays. So after a peak of herbivory, the 'ghost of herbivory past', i.e. the remaining infochemicals, may continue to induce colony formation, causing an additional lengthening of colony disintegration times and associated fitness costs (higher sedimentation loss rates. This indicates that costs of colony formation are not only important during the induction phase, but may be even more important during the relaxation phase. We compared these sedimentation costs to the costs of herbivory for differently sized Scenedesmus, and found a clear trade-off pattern for these costs.

  12. Effects of fire and herbivory on the stability of savanna ecosystems

    NARCIS (Netherlands)

    van Langevelde, F; van de Vijver, CADM; Kumar, L; van de Koppel, J; de Ridder, N; van Andel, J; Skidmore, AK; Hearne, JW; Stroosnijder, L; Bond, WJ; Prins, HHT; Rietkerk, M; Vijver, Claudius A.D.M. van de; Skidmore, Andrew K.; Hearne, John W.; Bond, William J.; Lauenroth, W.K.

    2003-01-01

    Savanna ecosystems are characterized by the co-occurrence of trees and grasses. In this paper, we argue that the balance between trees and grasses is, to a large extent,determined by the indirect interactive effects of herbivory and fire. These effects are based on the positive feedback between fuel

  13. Herbivory by a Phloem-feeding insect inhibits floral volatile production.

    Science.gov (United States)

    Pareja, Martin; Qvarfordt, Erika; Webster, Ben; Mayon, Patrick; Pickett, John; Birkett, Michael; Glinwood, Robert

    2012-01-01

    There is extensive knowledge on the effects of insect herbivory on volatile emission from vegetative tissue, but little is known about its impact on floral volatiles. We show that herbivory by phloem-feeding aphids inhibits floral volatile emission in white mustard Sinapis alba measured by gas chromatographic analysis of headspace volatiles. The effect of the Brassica specialist aphid Lipaphis erysimi was stronger than the generalist aphid Myzus persicae and feeding by chewing larvae of the moth Plutella xylostella caused no reduction in floral volatile emission. Field observations showed no effect of L. erysimi-mediated floral volatile emission on the total number of flower visits by pollinators. Olfactory bioassays suggested that although two aphid natural enemies could detect aphid inhibition of floral volatiles, their olfactory orientation to infested plants was not disrupted. This is the first demonstration that phloem-feeding herbivory can affect floral volatile emission, and that the outcome of interaction between herbivory and floral chemistry may differ depending on the herbivore's feeding mode and degree of specialisation. The findings provide new insights into interactions between insect herbivores and plant chemistry.

  14. Synergistic interactions between leaf beetle herbivory and fire enhance tamarisk (Tamarix spp.) mortality

    Science.gov (United States)

    Drus, Gail M.; Dudley, Tom L.; Antonio, Carla M.; Even, Thomas J.; Brooks, Matt L.; Matchett, J.R.

    2014-01-01

    The combined effects of herbivory and fire on plant mortality were investigated using prescribed burns of tamarisk (Tamarix ramosissima Lebed) exposed to herbivory by the saltcedar leaf beetle (Chrysomelidae: Diorhabda carinulata Desbrocher). Tamarix stands in the Humboldt Sink (NV, USA) were divided into three treatments: summer burn (August 2006), fall burn (October 2006) and control (unburned), and litter depth was manipulated to vary fire intensity within burn seasons. A gradient of existing herbivory impact was described with three plant condition metrics prior to fire: reduced proportions of green canopy, percent root crown starch sampled at the height of the growing season (August 2006), and percent root crown starch measured during dormancy (December 2006). August root crown starch concentration and proportion green canopy were strongly correlated, although the proportion green canopy predicted mortality better than August root crown starch. December root crown starch concentration was more depleted in unburned trees and in trees burned during the summer than in fall burn trees. Mortality in summer burned trees was higher than fall burned trees due to higher fire intensity, but December root crown starch available for resprouting in the spring was also lower in summer burned trees. The greatest mortality was observed in trees with the lowest December root crown starch concentration which were exposed to high fire intensity. Disproportionate changes in the slope and curvature of prediction traces as fire intensity and December starch reach reciprocal maximum and minimum levels indicate that beetle herbivory and fire intensity are synergistic.

  15. Effects of resource competition and herbivory on plant performance along a natural productivity gradient

    NARCIS (Netherlands)

    Van Der Wal, R; Egas, M; Bakker, J; van der Veen, A.

    2000-01-01

    1 The effects of resource competition and herbivory on a target species, Triglochin maritima, were studied along a productivity gradient of vegetation biomass in a temperate salt marsh. 2 Transplants were used to measure the impact of grazing, competition and soil fertility over two growing seasons.

  16. Effects of herbivory on the reproductive effort of 4 prairie perennials

    Directory of Open Access Journals (Sweden)

    Bradley Kate L

    2002-02-01

    Full Text Available Abstract Background Herbivory can affect every aspect of a plant's life. Damaged individuals may show decreased survivorship and reproductive output. Additionally, specific plant species (legumes and tissues (flowers are often selectively targeted by herbivores, like deer. These types of herbivory influence a plant's growth and abundance. The objective of this study was to identify the effects of leaf and meristem removal (simulated herbivory within an exclosure on fruit and flower production in four species (Rhus glabra, Rosa arkansana, Lathyrus venosus, and Phlox pilosa which are known targets of deer herbivory. Results Lathyrus never flowered or went to seed, so we were unable to detect any treatment effects. Leaf removal did not affect flower number in the other three species. However, Phlox, Rosa, and Rhus all showed significant negative correlations between seed mass and leaf removal. Meristem removal had a more negative effect than leaf removal on flower number in Phlox and on both flower number and seed mass in Rosa. Conclusions Meristem removal caused a greater response than defoliation alone in both Phlox and Rosa, which suggests that meristem loss has a greater effect on reproduction. The combination of leaf and meristem removal as well as recruitment limitation by deer, which selectively browse for these species, is likely to be one factor contributing to their low abundance in prairies.

  17. Forest loss increases insect herbivory levels in human-altered landscapes

    Science.gov (United States)

    Dodonov, Pavel; Morante-Filho, José Carlos; Mariano-Neto, Eduardo; Cazetta, Eliana; Andrade, Edyla Ribeiro de; Rocha-Santos, Larissa; Inforzato, Igor; Gomes, Francisco Sanches; Faria, Deborah

    2016-11-01

    Insect herbivory has been observed to be affected by habitat loss and fragmentation, although the mechanisms by which these anthropogenic disturbances affect this process are not well understood. To aid in clarifying this issue, we assessed the relation between forest cover and leaf damage caused by herbivorous insects on a representative tropical forest understory plant family, the Rubiaceae. We measured leaf area loss of Rubiaceae plants in 20 forest sites located in the Brazilian Atlantic forest, and also tested whether variation in forest cover, abundance of insectivorous birds (predators) and of Rubiaceae plants (resources) could explain the observed variation in leaf damage. Herbivory levels varied between 2.6 and 12.5 percent leaf area lost and increased with decreasing forest cover, whereas the other explanatory variables did not provide additional explanatory power. Therefore, forest loss appears to be the main driver of changes in local herbivory, and ecological processes such as top-down and bottom-up control may not account for the deforestation-related increase in herbivory levels. Other mechanisms, for example leaf quality and/or the influence of the adjoining land uses, have to be explored in future studies.

  18. Dealing with double trouble: consequences of single and double herbivory in Brassica juncea

    NARCIS (Netherlands)

    Mathur, V.; Tytgat, T.O.G.; Graaf, de R.M.; Kalia, V.; Reddy, A.S.; Vet, L.E.M.; Dam, van N.M.

    2013-01-01

    In their natural environment, plants are often attacked simultaneously by many insect species. The specificity of induced plant responses that is reported after single herbivore attacks may be compromised under double herbivory and this may influence later arriving herbivores. The present study focu

  19. The effect of structurally complex corals and herbivory on the dynamics of Halimeda

    Science.gov (United States)

    Castro-Sanguino, Carolina; Lovelock, Catherine; Mumby, Peter J.

    2016-06-01

    The calcareous green alga Halimeda is a key contributor to carbonate sediment production on coral reefs. As herbivores have a direct negative effect on the abundance of Halimeda, protection from herbivory is critical for Halimeda growth. Branching corals such as Acropora are likely to provide refugia for Halimeda from grazers, yet studies are scarce. Here, we investigated the vulnerability of two Halimeda species to herbivory using fish exclusion cages and assessed the contribution of coral structural complexity to seasonal changes in Halimeda biomass and morphometrics. While up to 50 % Halimeda abundance was depleted outside cages due to herbivory and the exclusion of large herbivores resulted in an increase in net growth up to threefold, Halimeda recruitment was positively affected by herbivory, more than two times greater outside cages. However, these responses differed between species and seasons; only one species was affected in winter but not summer. Coral structural complexity facilitated an increase of total algal biomass particularly in summer. At the individual level, thalli growing inside the Acropora canopy were always significantly larger (thallus biomass, volume and height) than those growing in exposed areas. We estimated that the carbonate production of Halimeda was nearly three times greater inside refuges provided by Acropora. Because Halimeda species differ in growth rates and susceptibility to grazing, we predict that the ongoing degradation of the habitat complexity provided by branching corals will alter Halimeda community structure and its contribution to local sediment budgets.

  20. Herbivory on the seagrass Cymodocea nodosa (Ucria) Ascherson in contrasting Spanish Mediterranean habitats

    NARCIS (Netherlands)

    Cebrian, J.; Duarte, C.M.; Marbà, N.

    1996-01-01

    We assess the magnitude and variability of herbivory (i.e. leaf consumption and sloughing caused by herbivore bites) on the seagrass Cymodocea nodosa along the Spanish Mediterranean coast and test the hypothesis that this is higher in meadows growing in sheltered bays than in exposed, open zones. To

  1. Ungulate herbivory modifies the effects of climate change on mountain forests

    NARCIS (Netherlands)

    Didion, M.P.; Kupferschmid, A.D.; Wolf, A.; Bugmann, H.

    2011-01-01

    Recent temperature observations suggest a general warming trend that may be causing the range of tree species to shift to higher latitudes and altitudes. Since biotic interactions such as herbivory can change tree species composition, it is important to understand their contribution to vegetation ch

  2. Recovering more than tree cover: herbivores and herbivory in a restored tropical dry forest.

    Directory of Open Access Journals (Sweden)

    Iris Juan-Baeza

    Full Text Available Intense and chronic disturbance may arrest natural succession, reduce environmental quality and lead to ecological interaction losses. Where natural succession does not occur, ecological restoration aims to accelerate this process. While plant establishment and diversity is promoted by restoration, few studies have evaluated the effect of restoration activities on ecological processes and animal diversity. This study assessed herbivory and lepidopteran diversity associated with two pioneer tree species growing in 4-year-old experimental restoration plots in a tropical dry forest at Sierra de Huautla, in Morelos, Mexico. The study was carried out during the rainy season of 2010 (July-October in eleven 50 x 50 m plots in three different habitats: cattle-excluded, cattle-excluded with restoration plantings, and cattle grazing plots. At the beginning of the rainy season, 10 juveniles of Heliocarpus pallidus (Malvaceae and Ipomoea pauciflora (Convolvulaceae were selected in each plot (N = 110 trees. Herbivory was measured in 10 leaves per plant at the end of the rainy season. To evaluate richness and abundance of lepidopteran larvae, all plants were surveyed monthly. Herbivory was similar among habitats and I. pauciflora showed a higher percentage of herbivory. A total of 868 lepidopteran larvae from 65 morphospecies were recorded. The family with the highest number of morphospecies (9 sp. was Geometridae, while the most abundant family was Saturnidae, with 427 individuals. Lepidopteran richness and abundance were significantly higher in H. pallidus than in I. pauciflora. Lepidopteran richness was significantly higher in the cattle-excluded plots, while abundance was significantly higher in the non-excluded plots. After four years of cattle exclusion and the establishment of plantings, lepidopteran richness increased 20 -fold in the excluded plots compared to the disturbed areas, whereas herbivory levels were equally high in both restored and

  3. Cascading effects of early-season herbivory on late-season herbivores and their parasitoids.

    Science.gov (United States)

    Hernandez-Cumplido, Johnattran; Glauser, Gaetan; Benrey, Betty

    2016-05-01

    There is an increasing awareness that herbivory by one insect species induces changes in a plant that affect the performance of other herbivore species that feed on the same plant. However, previous studies of interspecies interactions mediated by plant defense responses have rarely taken into account different insect guilds or the third trophic level. Using a combination of field and laboratory experiments, we examined how early-season herbivory in lima bean plants (Phaseolus lunatus) by the leaf-chewing herbivore Cerotoma ruficornis and the bean pod weevil Apion godmani affects the abundance and performance of the seed beetle Zabrotes subfasciatus and that of its parasitoid Stenocorse bruchivora, which occurs on the plants at the end of the growing season. In addition, we determined the consequences of early-season herbivore-induced defenses on plant performance. We hypothesized that early-season induction would affect plant reproduction and, hence, would alter the suitability of seeds for late-season seed-eating beetles, and that this would in turn alter the vulnerability of these seed beetles to parasitoids. We found strong support for these hypotheses. In the field, early-season herbivory negatively affected plant reproduction and seeds of these plants suffered lower levels of infestation by seed-eating beetles, which in turn suffered less parasitism. Laboratory assays with field-collected seeds confirmed that the performance of beetles and parasitoids was lower on seeds from plants that had been subjected to early-season herbivory. Further analyses revealed that seeds produced by control plants were larger, heavier, and had a higher concentration of cyanogenic glycosides and total protein content than seeds from plants subjected to herbivory. Our results provide insight into how direct and indirect interactions between and within different trophic levels affect the dynamics and structure of complex communities.

  4. Recovering More than Tree Cover: Herbivores and Herbivory in a Restored Tropical Dry Forest

    Science.gov (United States)

    2015-01-01

    Intense and chronic disturbance may arrest natural succession, reduce environmental quality and lead to ecological interaction losses. Where natural succession does not occur, ecological restoration aims to accelerate this process. While plant establishment and diversity is promoted by restoration, few studies have evaluated the effect of restoration activities on ecological processes and animal diversity. This study assessed herbivory and lepidopteran diversity associated with two pioneer tree species growing in 4-year-old experimental restoration plots in a tropical dry forest at Sierra de Huautla, in Morelos, Mexico. The study was carried out during the rainy season of 2010 (July-October) in eleven 50 x 50 m plots in three different habitats: cattle-excluded, cattle-excluded with restoration plantings, and cattle grazing plots. At the beginning of the rainy season, 10 juveniles of Heliocarpus pallidus (Malvaceae) and Ipomoea pauciflora (Convolvulaceae) were selected in each plot (N = 110 trees). Herbivory was measured in 10 leaves per plant at the end of the rainy season. To evaluate richness and abundance of lepidopteran larvae, all plants were surveyed monthly. Herbivory was similar among habitats and I. pauciflora showed a higher percentage of herbivory. A total of 868 lepidopteran larvae from 65 morphospecies were recorded. The family with the highest number of morphospecies (9 sp.) was Geometridae, while the most abundant family was Saturnidae, with 427 individuals. Lepidopteran richness and abundance were significantly higher in H. pallidus than in I. pauciflora. Lepidopteran richness was significantly higher in the cattle-excluded plots, while abundance was significantly higher in the non-excluded plots. After four years of cattle exclusion and the establishment of plantings, lepidopteran richness increased 20 –fold in the excluded plots compared to the disturbed areas, whereas herbivory levels were equally high in both restored and disturbed sites

  5. Plant allocation of carbon to defense as a function of herbivory, light and nutrient availability

    Science.gov (United States)

    DeAngelis, Donald L.; Ju, Shu; Liu, Rongsong; Bryant, John P.; Gourley, Stephen A.

    2012-01-01

    We use modeling to determine the optimal relative plant carbon allocations between foliage, fine roots, anti-herbivore defense, and reproduction to maximize reproductive output. The model treats these plant components and the herbivore compartment as variables. Herbivory is assumed to be purely folivory. Key external factors include nutrient availability, degree of shading, and intensity of herbivory. Three alternative functional responses are used for herbivory, two of which are variations on donor-dependent herbivore (models 1a and 1b) and one of which is a Lotka–Volterra type of interaction (model 2). All three were modified to include the negative effect of chemical defenses on the herbivore. Analysis showed that, for all three models, two stable equilibria could occur, which differs from most common functional responses when no plant defense component is included. Optimal strategies of carbon allocation were defined as the maximum biomass of reproductive propagules produced per unit time, and found to vary with changes in external factors. Increased intensity of herbivory always led to an increase in the fractional allocation of carbon to defense. Decreases in available limiting nutrient generally led to increasing importance of defense. Decreases in available light had little effect on defense but led to increased allocation to foliage. Decreases in limiting nutrient and available light led to decreases in allocation to reproduction in models 1a and 1b but not model 2. Increases in allocation to plant defense were usually accompanied by shifts in carbon allocation away from fine roots, possibly because higher plant defense reduced the loss of nutrients to herbivory.

  6. Recovering more than tree cover: herbivores and herbivory in a restored tropical dry forest.

    Science.gov (United States)

    Juan-Baeza, Iris; Martínez-Garza, Cristina; Del-Val, Ek

    2015-01-01

    Intense and chronic disturbance may arrest natural succession, reduce environmental quality and lead to ecological interaction losses. Where natural succession does not occur, ecological restoration aims to accelerate this process. While plant establishment and diversity is promoted by restoration, few studies have evaluated the effect of restoration activities on ecological processes and animal diversity. This study assessed herbivory and lepidopteran diversity associated with two pioneer tree species growing in 4-year-old experimental restoration plots in a tropical dry forest at Sierra de Huautla, in Morelos, Mexico. The study was carried out during the rainy season of 2010 (July-October) in eleven 50 x 50 m plots in three different habitats: cattle-excluded, cattle-excluded with restoration plantings, and cattle grazing plots. At the beginning of the rainy season, 10 juveniles of Heliocarpus pallidus (Malvaceae) and Ipomoea pauciflora (Convolvulaceae) were selected in each plot (N = 110 trees). Herbivory was measured in 10 leaves per plant at the end of the rainy season. To evaluate richness and abundance of lepidopteran larvae, all plants were surveyed monthly. Herbivory was similar among habitats and I. pauciflora showed a higher percentage of herbivory. A total of 868 lepidopteran larvae from 65 morphospecies were recorded. The family with the highest number of morphospecies (9 sp.) was Geometridae, while the most abundant family was Saturnidae, with 427 individuals. Lepidopteran richness and abundance were significantly higher in H. pallidus than in I. pauciflora. Lepidopteran richness was significantly higher in the cattle-excluded plots, while abundance was significantly higher in the non-excluded plots. After four years of cattle exclusion and the establishment of plantings, lepidopteran richness increased 20 -fold in the excluded plots compared to the disturbed areas, whereas herbivory levels were equally high in both restored and disturbed sites

  7. Pregnancy related symptomatic vertebral hemangioma

    Directory of Open Access Journals (Sweden)

    Meena Gupta

    2014-01-01

    Full Text Available Vertebral hemangiomas are benign vascular tumors of the spine that remain asymptomatic in most cases and incidentally encountered on imaging. Rarely, altered hemodynamic and hormonal changes during pregnancy may expand these benign lesions resulting in severe cord compression. The management of symptomatic vertebral hemangioma during pregnancy is controversial as modalities like radiotherapy and embolization are not suitable and surgery during pregnancy has a risk of preterm labor. Few cases of pregnancy related symptomatic vertebral hemangioma with marked epidural component have been reported in the literature. We report a case of 23-year-old primigravida who developed rapidly progressive paraparesis at 28 weeks of gestation and spine magnetic resonance imaging (MRI revealed upper thoracic vertebral hemangioma with extensive extra-osseous extension and spinal cord compression. Laminectomy and surgical decompression of the cord was performed at 32 weeks of the pregnancy. There was significant improvement in muscle power after a week of surgery. Six weeks postoperatively she delivered a full term normal baby with subsequent improvement of neurologic deficit. Repeat MRI of dorsal spine performed at 3 months postoperatively showed reduced posterior and anterior epidural components of vertebral hemangioma.

  8. Pregnancy related symptomatic vertebral hemangioma.

    Science.gov (United States)

    Gupta, Meena; Nayak, Rajeev; Singh, Hukum; Khwaja, Geeta; Chowdhury, Debashish

    2014-01-01

    Vertebral hemangiomas are benign vascular tumors of the spine that remain asymptomatic in most cases and incidentally encountered on imaging. Rarely, altered hemodynamic and hormonal changes during pregnancy may expand these benign lesions resulting in severe cord compression. The management of symptomatic vertebral hemangioma during pregnancy is controversial as modalities like radiotherapy and embolization are not suitable and surgery during pregnancy has a risk of preterm labor. Few cases of pregnancy related symptomatic vertebral hemangioma with marked epidural component have been reported in the literature. We report a case of 23-year-old primigravida who developed rapidly progressive paraparesis at 28 weeks of gestation and spine magnetic resonance imaging (MRI) revealed upper thoracic vertebral hemangioma with extensive extra-osseous extension and spinal cord compression. Laminectomy and surgical decompression of the cord was performed at 32 weeks of the pregnancy. There was significant improvement in muscle power after a week of surgery. Six weeks postoperatively she delivered a full term normal baby with subsequent improvement of neurologic deficit. Repeat MRI of dorsal spine performed at 3 months postoperatively showed reduced posterior and anterior epidural components of vertebral hemangioma.

  9. Vertebrate pressure-gradient receivers

    DEFF Research Database (Denmark)

    Christensen-Dalsgaard, Jakob

    2011-01-01

    The eardrums of all terrestrial vertebrates (tetrapods) are connected through Eustachian tubes or interaural canals. In some of the animals, these connections create pressure-gradient directionality, an enhanced directionality by interaction of sound arriving at both sides of the eardrum and stro......The eardrums of all terrestrial vertebrates (tetrapods) are connected through Eustachian tubes or interaural canals. In some of the animals, these connections create pressure-gradient directionality, an enhanced directionality by interaction of sound arriving at both sides of the eardrum....... Recent vertebrates form a continuum from perfect interaural transmission (0 dB in a certain frequency band) and pronounced eardrum directionality (30-40 dB) in the lizards, over somewhat attenuated transmission and limited directionality in birds and frogs, to the strongly attenuated interaural...

  10. The effect of chronic seaweed subsidies on herbivory: plant-mediated fertilization pathway overshadows lizard-mediated predator pathways.

    Science.gov (United States)

    Piovia-Scott, Jonah; Spiller, David A; Takimoto, Gaku; Yang, Louie H; Wright, Amber N; Schoener, Thomas W

    2013-08-01

    Flows of energy and materials link ecosystems worldwide and have important consequences for the structure of ecological communities. While these resource subsidies typically enter recipient food webs through multiple channels, most previous studies focussed on a single pathway of resource input. We used path analysis to evaluate multiple pathways connecting chronic marine resource inputs (in the form of seaweed deposits) and herbivory in a shoreline terrestrial ecosystem. We found statistical support for a fertilization effect (seaweed increased foliar nitrogen content, leading to greater herbivory) and a lizard numerical response effect (seaweed increased lizard densities, leading to reduced herbivory), but not for a lizard diet-shift effect (seaweed increased the proportion of marine-derived prey in lizard diets, but lizard diet was not strongly associated with herbivory). Greater seaweed abundance was associated with greater herbivory, and the fertilization effect was larger than the combined lizard effects. Thus, the bottom-up, plant-mediated effect of fertilization on herbivory overshadowed the top-down effects of lizard predators. These results, from unmanipulated shoreline plots with persistent differences in chronic seaweed deposition, differ from those of a previous experimental study of the short-term effects of a pulse of seaweed deposition: while the increase in herbivory in response to chronic seaweed deposition was due to the fertilization effect, the short-term increase in herbivory in response to a pulse of seaweed deposition was due to the lizard diet-shift effect. This contrast highlights the importance of the temporal pattern of resource inputs in determining the mechanism of community response to resource subsidies.

  11. Sexual and Asexual Reproduction of Salix sitchensis and the Influence of Beaver (Castor canadensis) Herbivory on Reproductive Success

    OpenAIRE

    Travis G. Gerwing; Alyssa M. Allen Gerwing; Rapaport, Eric; Alström-Rapaport, Cecilia

    2012-01-01

    The influence of beaver (Castor canadensis Kuhl) herbivory on Salix reproduction, specifically the stimulation of asexual reproduction via browsed stem fragments, is relatively unknown. This study aimed to determine if beaver herbivory stimulates asexual reproduction of riparian willows and results in mature populations dominated by clones. The survival of seedlings and asexual propagules produced by beaver browse in populations of the riparian willow Salix sitchensis (Sanson in Bongard) were...

  12. Early positive effects of tree species richness on herbivory in a large-scale forest biodiversity experiment influence tree growth

    OpenAIRE

    Schuldt, Andreas; Bruelheide, Helge; Härdtle, Werner; Assmann, Thorsten; Li, Ying; Ma, Keping; von Oheimb, Goddert; Zhang, Jiayong

    2015-01-01

    Despite the importance of herbivory for the structure and functioning of species-rich forests, little is known about how herbivory is affected by tree species richness, and more specifically by random vs. non-random species loss. We assessed herbivore damage and its effects on tree growth in the early stage of a large-scale forest biodiversity experiment in subtropical China that features random and non-random extinction scenarios of tree mixtures numbering between one and 24 species. In cont...

  13. Learning about Vertebrate Limb Development

    Science.gov (United States)

    Liang, Jennifer O.; Noll, Matthew; Olsen, Shayna

    2014-01-01

    We have developed an upper-level undergraduate laboratory exercise that enables students to replicate a key experiment in developmental biology. In this exercise, students have the opportunity to observe live chick embryos and stain the apical ectodermal ridge, a key tissue required for development of the vertebrate limb. Impressively, every…

  14. Early development of the vertebral column.

    Science.gov (United States)

    Scaal, Martin

    2016-01-01

    The segmental organization of the vertebrate body is most obviously visible in the vertebral column, which consists of a series of vertebral bones and interconnecting joints and ligaments. During embryogenesis, the vertebral column derives from the somites, which are the primary segments of the embryonic paraxial mesoderm. Anatomical, cellular and molecular aspects of vertebral column development have been of interest to developmental biologists for more than 150 years. This review briefly summarizes the present knowledge on early steps of vertebral column development in amniotes, starting from sclerotome formation and leading to the establishment of the anatomical bauplan of the spine composed of vertebral bodies, vertebral arches, intervertebral discs and ribs, and their specific axial identities along the body axis.

  15. Vertebral Geometry Parameters Can Predict Fractures

    Directory of Open Access Journals (Sweden)

    P Tofighi

    2007-01-01

    Conclusion: Vertebral fractures are common fractures in postmenopausal women. There was a correlation between verte¬bral height and fractures. Vertebral geometric parameters especially height T score can be used for fracture screening.

  16. Plant architecture and growth response of kudzu (fabaceae: Fabaceae) to simulated insect herbivory.

    Science.gov (United States)

    Frye, M J; Hough-Goldstein, J

    2013-10-01

    Kudzu [Pueraria montana variety lobata (Willd.) Maesen & S. M. Almeida] plant architecture and growth were compared for plants subjected to 4 wk of simulated herbivory (75% leaf cutting) and no damage. Simulated herbivory reduced above-ground and root biomass by 40 and 47%, respectively, whereas total vine length and average length of the 10 longest vines were reduced by 48 and 43%, respectively, compared with control plants. Plant architecture was also affected, with damaged plants showing a significantly reduced proportion of primary vines, shorter secondary vines, and reduced average internode distances compared with the control plants. In natural situations, these changes would reduce the ability of kudzu to compete for light and other resources by affecting the plant's climbing habit.

  17. Sharply increased insect herbivory during the Paleocene–Eocene Thermal Maximum

    Science.gov (United States)

    Currano, Ellen D.; Wilf, Peter; Wing, Scott L.; Labandeira, Conrad C.; Lovelock, Elizabeth C.; Royer, Dana L.

    2008-01-01

    The Paleocene–Eocene Thermal Maximum (PETM, 55.8 Ma), an abrupt global warming event linked to a transient increase in pCO2, was comparable in rate and magnitude to modern anthropogenic climate change. Here we use plant fossils from the Bighorn Basin of Wyoming to document the combined effects of temperature and pCO2 on insect herbivory. We examined 5,062 fossil leaves from five sites positioned before, during, and after the PETM (59–55.2 Ma). The amount and diversity of insect damage on angiosperm leaves, as well as the relative abundance of specialized damage, correlate with rising and falling temperature. All reach distinct maxima during the PETM, and every PETM plant species is extensively damaged and colonized by specialized herbivores. Our study suggests that increased insect herbivory is likely to be a net long-term effect of anthropogenic pCO2 increase and warming temperatures. PMID:18268338

  18. Interventional Management of Vertebral Body Metastases

    OpenAIRE

    Prince, Ethan A.; Ahn, Sun Ho

    2013-01-01

    Metastases to the vertebral column are often due to hypervascular primary tumors, the most common of which is renal cell carcinoma. Clinical symptoms attributed to vertebral body metastases include localized pain, mechanical instability of the vertebral column, and neurologic deficits resulting from mass effect. Treatment options include targeted radiotherapy, percutaneous vertebral augmentation with or without thermal ablation, and surgical resection with subsequent fusion. Overall, surgical...

  19. Evolution of endothelin receptors in vertebrates.

    Science.gov (United States)

    Braasch, Ingo; Schartl, Manfred

    2014-12-01

    Endothelin receptors are G protein coupled receptors (GPCRs) of the β-group of rhodopsin receptors that bind to endothelin ligands, which are 21 amino acid long peptides derived from longer prepro-endothelin precursors. The most basal Ednr-like GPCR is found outside vertebrates in the cephalochordate amphioxus, but endothelin ligands are only present among vertebrates, including the lineages of jawless vertebrates (lampreys and hagfishes), cartilaginous vertebrates (sharks, rays, and chimaeras), and bony vertebrates (ray-finned fishes and lobe-finned vertebrates including tetrapods). A bona fide endothelin system is thus a vertebrate-specific innovation with important roles for regulating the cardiovascular system, renal and pulmonary processes, as well as for the development of the vertebrate-specific neural crest cell population and its derivatives. Expectedly, dysregulation of endothelin receptors and the endothelin system leads to a multitude of human diseases. Despite the importance of different types of endothelin receptors for vertebrate development and physiology, current knowledge on endothelin ligand-receptor interactions, on the expression of endothelin receptors and their ligands, and on the functional roles of the endothelin system for embryonic development and in adult vertebrates is very much biased towards amniote vertebrates. Recent analyses from a variety of vertebrate lineages, however, have shown that the endothelin system in lineages such as teleost fish and lampreys is more diverse and is divergent from the mammalian endothelin system. This diversity is mainly based on differential evolution of numerous endothelin system components among vertebrate lineages generated by two rounds of whole genome duplication (three in teleosts) during vertebrate evolution. Here we review current understanding of the evolutionary history of the endothelin receptor family in vertebrates supplemented with surveys on the endothelin receptor gene complement of

  20. Combined effects of extreme climatic events and elevation on nutritional quality and herbivory of Alpine plants.

    Directory of Open Access Journals (Sweden)

    Annette Leingärtner

    Full Text Available Climatic extreme events can cause the shift or disruption of plant-insect interactions due to altered plant quality, e.g. leaf carbon to nitrogen ratios, and phenology. However, the response of plant-herbivore interactions to extreme events and climatic gradients has been rarely studied, although climatic extremes will increase in frequency and intensity in the future and insect herbivores represent a highly diverse and functionally important group. We set up a replicated climate change experiment along elevational gradients in the German Alps to study the responses of three plant guilds and their herbivory by insects to extreme events (extreme drought, advanced and delayed snowmelt versus control plots under different climatic conditions on 15 grassland sites. Our results indicate that elevational shifts in CN (carbon to nitrogen ratios and herbivory depend on plant guild and season. CN ratios increased with altitude for grasses, but decreased for legumes and other forbs. In contrast to our hypotheses, extreme climatic events did not significantly affect CN ratios and herbivory. Thus, our study indicates that nutritional quality of plants and antagonistic interactions with insect herbivores are robust against seasonal climatic extremes. Across the three functional plant guilds, herbivory increased with nitrogen concentrations. Further, increased CN ratios indicate a reduction in nutritional plant quality with advancing season. Although our results revealed no direct effects of extreme climatic events, the opposing responses of plant guilds along elevation imply that competitive interactions within plant communities might change under future climates, with unknown consequences for plant-herbivore interactions and plant community composition.

  1. Interactions among vegetation, climate, and herbivory control greenhouse gas fluxes in a subarctic coastal wetland

    Science.gov (United States)

    Kelsey, K. C.; Leffler, A. J.; Beard, K. H.; Schmutz, J. A.; Choi, R. T.; Welker, J. M.

    2016-12-01

    High-latitude ecosystems are experiencing the most rapid climate changes globally, and in many areas these changes are concurrent with shifts in patterns of herbivory. Individually, climate and herbivory are known to influence biosphere-atmosphere greenhouse gas (GHG) exchange; however, the interactive effects of climate and herbivory in driving GHG fluxes have been poorly quantified, especially in coastal systems that support large populations of migratory waterfowl. We investigated the magnitude and the climatic and physical controls of GHG exchange within the Yukon-Kuskokwim Delta in western Alaska across four distinct vegetation communities formed by herbivory and local microtopography. Net CO2 flux was greatest in the ungrazed Carex meadow community (3.97 ± 0.58 [SE] µmol CO2 m-2 s-1), but CH4 flux was greatest in the grazed community (14.00 ± 6.56 nmol CH4 m-2 s-1). The grazed community is also the only vegetation type where CH4 was a larger contributor than CO2 to overall GHG forcing. We found that vegetation community was an important predictor of CO2 and CH4 exchange, demonstrating that variation in regional gas exchange is best explained when the effect of grazing, determined by the difference between grazed and ungrazed communities, is included. Further, we identified an interaction between temperature and vegetation community, indicating that grazed regions could experience the greatest increases in CH4 emissions with warming. These results suggest that future GHG fluxes could be influenced by both climate and by changes in herbivore population dynamics that expand or contract the vegetation community most responsive to future temperature change.

  2. Genetic Based Plant Resistance and Susceptibility Traits to Herbivory Influence Needle and Root Litter Nutrient Dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Classen, Aimee T [ORNL; Chapman, Samantha K. [Smithsonian Environmental Research Center, Edgewater, MD; Whitham, Thomas G [Northern Arizona University; Hart, Stephen C [Northern Arizona University; Koch, George W [Northern Arizona University

    2007-01-01

    It is generally assumed that leaf and root litter decomposition have similar drivers and that nutrient release from these substrates is synchronized. Few studies have examined these assumptions, and none has examined how plant genetics (i.e., plant susceptibility to herbivory) could affect these relationships. Here we examine the effects of herbivore susceptibility and resistance on needle and fine root litter decomposition of pi on pine, Pinus edulis. The study population consists of individual trees that are either susceptible or resistant to herbivory by the pi on needle scale, Matsucoccus acalyptus, or the stem-boring moth, Dioryctria albovittella. Genetic analyses and experimental removals and additions of these insects have identified trees that are naturally resistant and susceptible to these insects. These herbivores increase the chemical quality of litter inputs and alter soil microclimate, both of which are important decomposition drivers. Our research leads to four major conclusions: Herbivore susceptibility and resistance effects on 1) needle litter mass loss and phosphorus (P) retention in moth susceptible and resistant litter are governed by microclimate, 2) root litter nitrogen (N) and P retention, and needle litter N retention are governed by litter chemical quality, 3) net nutrient release from litter can reverse over time, 4) root and needle litter mass loss and nutrient release are determined by location (above- vs. belowground), suggesting that the regulators of needle and root decomposition differ at the local scale. Understanding of decomposition and nutrient retention in ecosystems requires consideration of herbivore effects on above- and belowground processes and how these effects may be governed by plant genotype. Because an underlying genetic component to herbivory is common to most ecosystems of the world and herbivory may increase in climatic change scenarios, it is important to evaluate the role of plant genetics in affecting carbon and

  3. Recovering More than Tree Cover: Herbivores and Herbivory in a Restored Tropical Dry Forest

    OpenAIRE

    Iris Juan-Baeza; Cristina Martínez-Garza; Ek Del-Val

    2015-01-01

    Intense and chronic disturbance may arrest natural succession, reduce environmental quality and lead to ecological interaction losses. Where natural succession does not occur, ecological restoration aims to accelerate this process. While plant establishment and diversity is promoted by restoration, few studies have evaluated the effect of restoration activities on ecological processes and animal diversity. This study assessed herbivory and lepidopteran diversity associated with two pioneer tr...

  4. Epiphyte presence and seagrass species identity influence rates of herbivory in Mediterranean seagrass meadows

    Science.gov (United States)

    Marco-Méndez, Candela; Ferrero-Vicente, Luis Miguel; Prado, Patricia; Heck, Kenneth L.; Cebrián, Just; Sánchez-Lizaso, Jose Luis

    2015-03-01

    Herbivory on Mediterranean seagrass species is generally low compared to consumption of some other temperate and tropical species of seagrasses. In this study we: (1) investigate the feeding preference of the two dominant Mediterranean seagrass herbivores, the sea urchin Paracentrotus lividus and the fish Sarpa salpa, on Posidonia oceanica and Cymodocea nodosa and (2) elucidate the role of epiphytes in herbivore choices. We assessed consumption rates by tethering seagrass shoots, and preferences by food choice experiments with the following paired combinations: 1) Epiphytized leaves of both C. nodosa vs. P. oceanica (CE vs PE); 2) Non-epiphytized leaves of C. nodosa vs. P. oceanica (CNE vs. PNE); 3) Epiphytized vs non-epiphytized leaves of C. nodosa (CE vs. CNE) and 4) Epiphytized vs non-epiphytized leaves of P. oceanica (PE vs PNE). We found that preference for C. nodosa was weak for S. salpa, but strong for P. lividus, the species responsible for most consumption at our study. Overall both herbivores showed preference for epiphytized leaves. The higher nutritional quality of C. nodosa leaves and epiphytes together with the high coverage and diversity of the epiphyte community found on its leaves help explain the higher levels of herbivory recorded on epiphyted leaves of C. nodosa. Other factors such as seagrass accessibility, herbivore mobility and size, and behavioral responses to predation risks, may also affect the intensity of seagrass herbivory, and studies addressing the interactions with these factors are needed to improve our understanding of the nature, extent and implications of herbivory in coastal ecosystems.

  5. An invertebrate stomach's view on vertebrate ecology

    DEFF Research Database (Denmark)

    Calvignac-Spencer, Sebastien; Leendertz, Fabian H.; Gilbert, M. Thomas P.

    2013-01-01

    Recent studies suggest that vertebrate genetic material ingested by invertebrates (iDNA) can be used to investigate vertebrate ecology. Given the ubiquity of invertebrates that feed on vertebrates across the globe, iDNA might qualify as a very powerful tool for 21st century population...

  6. Cucumis melo microRNA expression profile during aphid herbivory in a resistant and susceptible interaction.

    Science.gov (United States)

    Sattar, Sampurna; Song, Yan; Anstead, James A; Sunkar, Ramanjulu; Thompson, Gary A

    2012-06-01

    Aphis gossypii resistance in melon (Cucumis melo) is due to the presence of a single dominant virus aphid transmission (Vat) gene belonging to the nucleotide-binding site leucine-rich repeat family of resistance genes. Significant transcriptional reprogramming occurs in Vat(+) plants during aphid infestation as metabolism shifts to respond to this biotic stress. MicroRNAs (miRNAs) are involved in the regulation of many biotic stress responses. The role of miRNAs was investigated in response to aphid herbivory during both resistant and susceptible interactions. Small RNA (smRNA) libraries were constructed from bulked leaf tissues of a Vat(+) melon line following early and late aphid infestations. Sequence analysis indicated that the expression profiles of conserved and newly identified miRNAs were altered during different stages of aphid herbivory. These results were verified by quantitative polymerase chain reaction experiments in both resistant Vat(+) and susceptible Vat(-) interactions. The comparative analyses revealed that most of the conserved miRNA families were differentially regulated during the early stages of aphid infestation in the resistant and susceptible interactions. Along with the conserved miRNA families, 18 cucurbit-specific miRNAs were expressed during the different stages of aphid herbivory. The comparison of the miRNA profiles in the resistant and susceptible interactions provides insight into the miRNA-dependent post-transcriptional gene regulation in Vat-mediated resistance.

  7. Herbivory, plant resistance, and climate in the tree ring record: interactions distort climatic reconstructions.

    Science.gov (United States)

    Trotter, R Talbot; Cobb, Neil S; Whitham, Thomas G

    2002-07-23

    To understand climate change, dendrochronologists have used tree ring analyses to reconstruct past climates, as well as ecological processes such as herbivore population dynamics. Such reconstructions, however, have been hindered by a lack of experiments that separate the influences of confounding impacts on tree rings, such as herbivores and the interactions of multiple factors. Our long-term experiments with scale insects on resistant and susceptible pines demonstrate three major points that are important to the application of this commonly used tool. (i) Herbivory reduced tree ring growth by 25-35%. (ii) The impact on ring growth distorted climate reconstruction, resulting in the overestimation of past moisture levels by more than 2-fold. Our data suggest that, if distortion because of herbivory has been a problem in previous reconstructions, estimates of the magnitude of recent climate changes are likely to be conservative. (iii) Our studies support a detectible plant resistance x herbivore x climate interaction in the tree ring record. Because resistance and susceptibility to herbivory are known to be genetically based in many systems, the potential exists to incorporate plant genetics into the field of dendrochronology, where it may be used to screen distortions from the tree ring record.

  8. How plants connect pollination and herbivory networks and their contribution to community stability.

    Science.gov (United States)

    Sauve, Alix M C; Thébault, Elisa; Pocock, Michael J O; Fontaine, Colin

    2016-04-01

    Pollination and herbivory networks have mainly been studied separately, highlighting their distinct structural characteristics and the related processes and dynamics. However, most plants interact with both pollinators and herbivores, and there is evidence that both types of interaction affect each other. Here we investigated the way plants connect these mutualistic and antagonistic networks together, and the consequences for community stability. Using an empirical data set, we show that the way plants connect pollination and herbivory networks is not random and promotes community stability. Analyses of the structure of binary and quantitative networks show different results: the plants' generalism with regard to pollinators is positively correlated to their generalism with regard to herbivores when considering binary interactions, but not when considering quantitative interactions. We also show that plants that share the same pollinators do not share the same herbivores. However, the way plants connect pollination and herbivory networks promotes stability for both binary and quantitative networks. Our results highlight the relevance of considering the diversity of interaction types in ecological communities, and stress the need to better quantify the costs and benefits of interactions, as well as to develop new metrics characterizing the way different interaction types are combined within ecological networks.

  9. Patterns in soil fertility and root herbivory interact to influence fine-root dynamics.

    Science.gov (United States)

    Stevens, Glen N; Jones, Robert H

    2006-03-01

    Fine-scale soil nutrient enrichment typically stimulates root growth, but it may also increase root herbivory, resulting in trade-offs for plant species and potentially influencing carbon cycling patterns. We used root ingrowth cores to investigate the effects of microsite fertility and root herbivory on root biomass in an aggrading upland forest in the coastal plain of South Carolina, USA. Treatments were randomly assigned to cores from a factorial combination of fertilizer and insecticide. Soil, soil fauna, and roots were removed from the cores at the end of the experiment (8-9 mo), and roots were separated at harvest into three diameter classes. Each diameter class responded differently to fertilizer and insecticide treatments. The finest roots (root biomass, were the only ones to respond significantly to both treatments, increasing when fertilizer and when insecticide were added (each P root-feeding insects have a strong influence on root standing crop with stronger herbivore impacts on finer roots and within more fertile microsites. Thus, increased vulnerability to root herbivory is a potentially significant cost of root foraging in nutrient-rich patches.

  10. Tolerance to deer herbivory and resistance to insect herbivores in the common evening primrose (Oenothera biennis).

    Science.gov (United States)

    Puentes, A; Johnson, M T J

    2016-01-01

    The evolution of plant defence in response to herbivory will depend on the fitness effects of damage, availability of genetic variation and potential ecological and genetic constraints on defence. Here, we examine the potential for evolution of tolerance to deer herbivory in Oenothera biennis while simultaneously considering resistance to natural insect herbivores. We examined (i) the effects of deer damage on fitness, (ii) the presence of genetic variation in tolerance and resistance, (iii) selection on tolerance, (iv) genetic correlations with resistance that could constrain evolution of tolerance and (v) plant traits that might predict defence. In a field experiment, we simulated deer damage occurring early and late in the season, recorded arthropod abundances, flowering phenology and measured growth rate and lifetime reproduction. Our study showed that deer herbivory has a negative effect on fitness, with effects being more pronounced for late-season damage. Selection acted to increase tolerance to deer damage, yet there was low and nonsignificant genetic variation in this trait. In contrast, there was substantial genetic variation in resistance to insect herbivores. Resistance was genetically uncorrelated with tolerance, whereas positive genetic correlations in resistance to insect herbivores suggest there exists diffuse selection on resistance traits. In addition, growth rate and flowering time did not predict variation in tolerance, but flowering phenology was genetically correlated with resistance. Our results suggest that deer damage has the potential to exert selection because browsing reduces plant fitness, but limited standing genetic variation in tolerance is expected to constrain adaptive evolution in O. biennis.

  11. Ungulate herbivory on alpine willow in the Sangre de Cristo Mountains of Colorado

    Science.gov (United States)

    Zeigenfuss, L.C.; Schoenecker, K.A.; Amburg, L.K.V.

    2011-01-01

    In many areas of the Rocky Mountains, elk (Cervus elaphus) migrate from low-elevation mountain valleys during spring to high-elevation subalpine and alpine areas for the summer. Research has focused on the impacts of elk herbivory on winter-range plant communities, particularly on woody species such as willow and aspen; however, little information is available on the effects of elk herbivory on alpine willows. In the Sangre de Cristo Mountains of south central Colorado, select alpine areas appear to receive high levels of summer elk herbivory, while other areas are nearly unbrowsed. In 2005 and 2008, we measured willow height, cover, and utilization on sites that appeared to be used heavily by elk, as well as on sites that appeared to be used lightly, to determine differences between these communities over time. We found less willow cover and shorter willows at sites that received higher levels of browsing compared to those that had lower levels of browsing. Human recreational use was greater at lightly browsed sites than at highly browsed sites. From 2005 to 2008, willow utilization declined, and willow cover and height increased at sites with heavy browsing, likely owing to ownership change of adjacent valley land which led to (1) removal of grazing competition from, cattle at valley locations and (2) increased human use in alpine areas, which displaced elk. We discuss the implications of increased human use and climate change on elk use of these alpine habitats. ?? 2011.

  12. Impacts of simulated herbivory on volatile organic compound emission profiles from coniferous plants

    Science.gov (United States)

    Faiola, C. L.; Jobson, B. T.; VanReken, T. M.

    2015-01-01

    The largest global source of volatile organic compounds (VOCs) in the atmosphere is from biogenic emissions. Plant stressors associated with a changing environment can alter both the quantity and composition of the compounds that are emitted. This study investigated the effects of one global change stressor, increased herbivory, on plant emissions from five different coniferous species: bristlecone pine (Pinus aristata), blue spruce (Picea pungens), western redcedar (Thuja plicata), grand fir (Abies grandis), and Douglas-fir (Pseudotsuga menziesii). Herbivory was simulated in the laboratory via exogenous application of methyl jasmonate (MeJA), a herbivory proxy. Gas-phase species were measured continuously with a gas chromatograph coupled to a mass spectrometer and flame ionization detector (GC-MS-FID). Stress responses varied between the different plant types and even between experiments using the same set of saplings. The compounds most frequently impacted by the stress treatment were alpha-pinene, beta-pinene, 1,8-cineol, beta-myrcene, terpinolene, limonene, and the cymene isomers. Individual compounds within a single experiment often exhibited a different response to the treatment from one another.

  13. Impacts of simulated herbivory on VOC emission profiles from coniferous plants

    Directory of Open Access Journals (Sweden)

    C. L. Faiola

    2014-09-01

    Full Text Available The largest global source of volatile organic compounds (VOCs in the atmosphere is from biogenic emissions. Plant stressors associated with a changing environment can alter both the quantity and composition of the compounds that are emitted. This study investigated the effects of one global change stressor, increased herbivory, on plant emissions from five different coniferous species: bristlecone pine (Pinus aristata, blue spruce (Picea pungens, western redcedar (Thuja plicata, grand fir (Abies grandis, and Douglas-fir (Pseudotsugas menziesii. Herbivory was simulated in the laboratory via exogenous application of methyl jasmonate, an herbivory proxy. Gas-phase species were measured continuously with a gas chromatograph coupled to a mass spectrometer and flame ionization detector (GC-MS-FID. Stress responses varied between the different plant types and even between experiments using the same set of saplings. The compounds most frequently impacted by the stress treatment were alpha-pinene, beta-pinene, 1,8-cineol, beta-myrcene, terpinolene, limonene, and the cymene isomers. Individual compounds within a single experiment often exhibited a different response to the treatment from one another.

  14. Impacts of simulated herbivory on VOC emission profiles from coniferous plants

    Science.gov (United States)

    Faiola, C. L.; Jobson, B. T.; VanReken, T. M.

    2014-09-01

    The largest global source of volatile organic compounds (VOCs) in the atmosphere is from biogenic emissions. Plant stressors associated with a changing environment can alter both the quantity and composition of the compounds that are emitted. This study investigated the effects of one global change stressor, increased herbivory, on plant emissions from five different coniferous species: bristlecone pine (Pinus aristata), blue spruce (Picea pungens), western redcedar (Thuja plicata), grand fir (Abies grandis), and Douglas-fir (Pseudotsugas menziesii). Herbivory was simulated in the laboratory via exogenous application of methyl jasmonate, an herbivory proxy. Gas-phase species were measured continuously with a gas chromatograph coupled to a mass spectrometer and flame ionization detector (GC-MS-FID). Stress responses varied between the different plant types and even between experiments using the same set of saplings. The compounds most frequently impacted by the stress treatment were alpha-pinene, beta-pinene, 1,8-cineol, beta-myrcene, terpinolene, limonene, and the cymene isomers. Individual compounds within a single experiment often exhibited a different response to the treatment from one another.

  15. Land-use legacies and present fire regimes interact to mediate herbivory by altering the neighboring plant community.

    Energy Technology Data Exchange (ETDEWEB)

    Hahn, Philip G. [University of Wisconsin; Orrock, John L. [University of Wisconsin

    2015-04-01

    Past and present human activities, such as historic agriculture and fire suppression, are widespread and can create depauperate plant communities. Although many studies show that herbivory on focal plants depends on the density of herbivores or the composition of the surrounding plant community, it is unclear whether anthropogenic changes to plant communities alter herbivory. We tested the hypothesis that human activities that alter the plant community lead to subsequent changes in herbivory. At 20 sites distributed across 80 300 hectares, we conducted a field experiment that manipulated insect herbivore access (full exclosures and pseudo-exclosures) to four focal plant species in longleaf pine woodlands with diff erent land-use histories (post-agricultural sites or non-agricultural sites) and degrees of fi re frequency (frequent and infrequent). Plant cover, particularly herbaceous cover, was lower in post-agricultural and fi re suppressed woodlands. Density of the dominant insect herbivore at our site (grasshoppers) was positively related to plant cover. Herbivore access reduced biomass of the palatable forb Solidago odora in frequently burned post-agricultural sites and in infrequently burned non-agricultural woodlands and increased mortality of another forb (Pityopsis graminifolia ), but did not aff ect two other less palatable species ( Schizachyrium scoparium and Tephrosia virginiana ). Herbivory on S. odora exhibited a hump-shaped response to plant cover, with low herbivory at low and high levels of plant cover. Herbivore density had a weak negative effect on herbivory. These findings suggest that changes in plant cover related to past and present human activities can modify damage rates on focal S. odora plants by altering grasshopper foraging behavior rather than by altering local grasshopper density. The resulting changes in herbivory may have the potential to limit natural recovery or restoration eff orts by reducing the establishment or performance of

  16. Response of the coral reef benthos and herbivory to fishery closure management and the 1998 ENSO disturbance.

    Science.gov (United States)

    McClanahan, T R

    2008-02-01

    The hypothesis that herbivory is higher in areas without fishing and will increase the rate at which hard coral communities return to pre-disturbance conditions was tested in and out of the marine protected areas (MPA) of Kenya after the 1998 El Niño Southern Oscillation (ENSO). Herbivory was estimated by assay and biomass methods, and both methods indicated higher herbivory in fishery closures. Despite higher herbivory, the effect of the ENSO disturbance was larger within these closures, with reefs undergoing a temporary transition from dominance by hard and soft coral to a temporary dominance of turf and erect algae that ended in the dominance of calcifying algae, massive Porites, Pocillopora and a few faviids six years after the disturbance. The fished reefs changed the least but had a greater cover of turf and erect algae and sponge shortly after the disturbance. Higher herbivory in the fishery closures reduced the abundance and persistence of herbivore-susceptible erect algae and created space and appropriate substratum for recruiting corals. Nonetheless, other post-settlement processes may have had strong influences such that annual rates of coral recovery were low ( approximately 2%) and not different between the management regimes. Recovery, as defined as and measured by the return to pre-disturbance coral cover and the dominant taxa, was slower in fishery closures than unmanaged reefs.

  17. Influence of Genotype, Environment, and Gypsy Moth Herbivory on Local and Systemic Chemical Defenses in Trembling Aspen (Populus tremuloides).

    Science.gov (United States)

    Rubert-Nason, Kennedy F; Couture, John J; Major, Ian T; Constabel, C Peter; Lindroth, Richard L

    2015-07-01

    Numerous studies have explored the impacts of intraspecific genetic variation and environment on the induction of plant chemical defenses by herbivory. Relatively few, however, have considered how those factors affect within-plant distribution of induced defenses. This work examined the impacts of plant genotype and soil nutrients on the local and systemic phytochemical responses of trembling aspen (Populus tremuloides) to defoliation by gypsy moth (Lymantria dispar). We deployed larvae onto foliage on individual tree branches for 15 days and then measured chemistry in leaves from: 1) branches receiving damage, 2) undamaged branches of insect-damaged trees, and 3) branches of undamaged control trees. The relationship between post-herbivory phytochemical variation and insect performance also was examined. Plant genotype, soil nutrients, and damage all influenced phytochemistry, with genotype and soil nutrients being stronger determinants than damage. Generally, insect damage decreased foliar nitrogen, increased levels of salicinoids and condensed tannins, but had little effect on levels of a Kunitz trypsin inhibitor, TI3. The largest damage-mediated tannin increases occurred in leaves on branches receiving damage, whereas the largest salicinoid increases occurred in leaves of adjacent, undamaged branches. Foliar nitrogen and the salicinoid tremulacin had the strongest positive and negative relationships, respectively, with insect growth. Overall, plant genetics and environment concomitantly influenced both local and systemic phytochemical responses to herbivory. These findings suggest that herbivory can contribute to phytochemical heterogeneity in aspen foliage, which may in turn influence future patterns of herbivory and nutrient cycling over larger spatial scales.

  18. Defense pattern of Chinese cork oak across latitudinal gradients: influences of ontogeny, herbivory, climate and soil nutrients.

    Science.gov (United States)

    Wang, Xiao-Fei; Liu, Jian-Feng; Gao, Wen-Qiang; Deng, Yun-Peng; Ni, Yan-Yan; Xiao, Yi-Hua; Kang, Feng-Feng; Wang, Qi; Lei, Jing-Pin; Jiang, Ze-Ping

    2016-01-01

    Knowledge of latitudinal patterns in plant defense and herbivory is crucial for understanding the mechanisms that govern ecosystem functioning and for predicting their responses to climate change. Using a widely distributed species in East Asia, Quercus variabilis, we aim to reveal defense patterns of trees with respect to ontogeny along latitudinal gradients. Six leaf chemical (total phenolics and total condensed tannin concentrations) and physical (cellulose, hemicellulose, lignin and dry mass concentration) defensive traits as well as leaf herbivory (% leaf area loss) were investigated in natural Chinese cork oak (Q. variabilis) forests across two ontogenetic stages (juvenile and mature trees) along a ~14°-latitudinal gradient. Our results showed that juveniles had higher herbivory values and a higher concentration of leaf chemical defense substances compared with mature trees across the latitudinal gradient. In addition, chemical defense and herbivory in both ontogenetic stages decreased with increasing latitude, which supports the latitudinal herbivory-defense hypothesis and optimal defense theory. The identified trade-offs between chemical and physical defense were primarily determined by environmental variation associated with the latitudinal gradient, with the climatic factors (annual precipitation, minimum temperature of the coldest month) largely contributing to the latitudinal defense pattern in both juvenile and mature oak trees.

  19. Defense pattern of Chinese cork oak across latitudinal gradients: influences of ontogeny, herbivory, climate and soil nutrients

    Science.gov (United States)

    Wang, Xiao-Fei; Liu, Jian-Feng; Gao, Wen-Qiang; Deng, Yun-Peng; Ni, Yan-Yan; Xiao, Yi-Hua; Kang, Feng-Feng; Wang, Qi; Lei, Jing-Pin; Jiang, Ze-Ping

    2016-06-01

    Knowledge of latitudinal patterns in plant defense and herbivory is crucial for understanding the mechanisms that govern ecosystem functioning and for predicting their responses to climate change. Using a widely distributed species in East Asia, Quercus variabilis, we aim to reveal defense patterns of trees with respect to ontogeny along latitudinal gradients. Six leaf chemical (total phenolics and total condensed tannin concentrations) and physical (cellulose, hemicellulose, lignin and dry mass concentration) defensive traits as well as leaf herbivory (% leaf area loss) were investigated in natural Chinese cork oak (Q. variabilis) forests across two ontogenetic stages (juvenile and mature trees) along a ~14°-latitudinal gradient. Our results showed that juveniles had higher herbivory values and a higher concentration of leaf chemical defense substances compared with mature trees across the latitudinal gradient. In addition, chemical defense and herbivory in both ontogenetic stages decreased with increasing latitude, which supports the latitudinal herbivory-defense hypothesis and optimal defense theory. The identified trade-offs between chemical and physical defense were primarily determined by environmental variation associated with the latitudinal gradient, with the climatic factors (annual precipitation, minimum temperature of the coldest month) largely contributing to the latitudinal defense pattern in both juvenile and mature oak trees.

  20. Osteomielitis vertebral piógena Pyogenic vertebral osteomyelitis

    Directory of Open Access Journals (Sweden)

    Pedro P. Perrotti

    2009-10-01

    Full Text Available La osteomielitis vertebral piógena (OVP es una localización poco frecuente (2-7% Se confirma con el aislamiento de un microorganismo de una vértebra, disco intervertebral, absceso epidural o paravertebral. Se describe una serie de casos por la infrecuente presentación de esta enfermedad, que puede ser consulta inicial en los servicios de clínica médica y por su sintomatología inespecífica que supone una dificultad diagnóstica. Tanto la columna lumbar como la dorsal fueron los sitios más afectados. El dolor dorsolumbar y la paraparesia fueron los síntomas más frecuentes de presentación. En ocho pacientes se aislaron Staphylococcus aureus, en uno Escherichia coli y en el restante Haemophylus sp. Se observó leucocitosis sólo en tres pacientes, y en dos velocidad de sedimentación globular mayor de 100 mm/h. Los diez pacientes presentaron imágenes características de osteomielitis vertebral piógena en la resonancia nuclear magnética. Dentro de las complicaciones, los abscesos paravertebrales y epidurales fueron los más frecuentes (en cinco enfermos. Además, un paciente presentó empiema pleural. De los diez pacientes de esta serie, siete recibieron inicialmente tratamiento médico empírico y luego específico para el germen aislado. En los restantes el tratamiento fue guiado de acuerdo al antibiograma. A dos enfermos fue necesario realizarles laminectomía descompresiva por compromiso de partes blandas y a otros dos estabilización quirúrgica por inestabilidad espinal, observándose buena evolución en todos los casos. Esta serie demuestra que, ante un paciente con dolor dorsolumbar y síntomas neurológicos se deberá tener en cuenta esta entidad para evitar un retraso en el tratamiento.Pyogenic osteomyelitis seldom affects the spine (2-7%. It is diagnosed by the isolation of a bacterial agent in the vertebral body, the intervertebral disks or from paravertebral or epidural abscesses. We report a retrospective study of ten

  1. The origin of herbivory on land: Initial patterns of plant tissue consumption by arthropods

    Institute of Scientific and Technical Information of China (English)

    CONRAD LABANDEIRA

    2007-01-01

    The early fossil record of terrestrial arthropod herbivory consists of two pulses.The first pulse was concentrated during the latest Silurian to Early Devonian (417 to 403 Ma),and consists of the earliest evidence for consumption of sporangia and stems (and limited fungivore borings). Herbivorization of most of these tissues was rapid, representing 0 to 20 million-year (m.y.) lags from the earliest occurrences of these organs in the fossil record to their initial consumption (Phase 1). For approximately the next 75 m.y., there was a second,more histologically varied origination and expansion of roots, leaves, wood and seeds,whose earliest evidence for herbivorization occurred from the Middle-Late Mississippian boundary to the Middle Pennsylvanian (327 to 309 Ma). The appearance of this second herbivory pulse during the later Paleozoic (Phase 2) is accompanied by major lags of 98 to 54 m.y. between times of appearance of each of the four organ and tissue types and their subsequent herbivory. Both pulses provide a context for three emerging questions. First is an explanation for the contrast between the near instantaneous consumption of plant tissues during Phase 1, versus the exceptionally long lags between the earliest occurrences of plant tissues and their subsequent herbivorization during Phase 2. Second is the identity of arthropod herbivores for both phases. Third is the cause behind the overwhelming targeting of seed-fern plant hosts during Phase 2. Regardless of the answers to these questions, the trace fossil record of plant-arthropod associations provides primary ecological data that remain unaddressed by the body-fossil record alone.

  2. Effects of flooding, salinity and herbivory on coastal plant communities, Louisiana, United States

    Science.gov (United States)

    Gough, L.; Grace, J.B.

    1998-01-01

    Flooding and salinity stress are predicted to increase in coastal Louisiana as relative sea level rise (RSLR) continues in the Gulf of Mexico region. Although wetland plant species are adapted to these stressors, questions persist as to how marshes may respond to changed abiotic variables caused by RSLR, and how herbivory by native and non-native mammals may affect this response. The effects of altered flooding and salinity on coastal marsh communities were examined in two field experiments that simultaneously manipulated herbivore pressure. Marsh sods subjected to increased or decreased flooding (by lowering or raising sods, respectively), and increased or decreased salinity (by reciprocally transplanting sods between a brackish and fresh marsh), were monitored inside and outside mammalian herbivore exclosures for three growing seasons. Increased flooding stress reduced species numbers and biomass; alleviating flooding stress did not significantly alter species numbers while community biomass increased. Increased salinity reduced species numbers and biomass, more so if herbivores were present. Decreasing salinity had an unexpected effect: herbivores selectively consumed plants transplanted from the higher-salinity site. In plots protected from herbivory, decreased salinity had little effect on species numbers or biomass, but community composition changed. Overall, herbivore pressure further reduced species richness and biomass under conditions of increased flooding and increased salinity, supporting other findings that coastal marsh species can tolerate increasingly stressful conditions unless another factor, e.g., herbivory, is also present. Also, species dropped out of more stressful treatments much faster than they were added when stresses were alleviated, likely due to restrictions on dispersal. The rate at which plant communities will shift as a result of changed abiotic variables will determine if marshes remain viable when subjected to RSLR.

  3. The role of genetic and chemical variation of Pinus sylvestris seedlings in influencing slug herbivory.

    Science.gov (United States)

    O'Reilly-Wapstra, Julianne M; Iason, Glenn R; Thoss, Vera

    2007-05-01

    This study investigated the genetic and chemical basis of resistance of Pinus sylvestris seedlings to herbivory by a generalist mollusc, Arion ater. Using feeding trials with captive animals, we examined selective herbivory by A. ater of young P. sylvestris seedlings of different genotypes and correlated preferences with seedling monoterpene levels. We also investigated the feeding responses of A. ater to artificial diets laced with two monoterpenes, Delta(3)-carene and alpha-pinene. Logistic regression indicated that two factors were the best predictors of whether seedlings in the trial would be consumed. Individual slug variation (replicates) was the most significant factor in the model; however, alpha-pinene concentration (also representing beta-pinene, Delta(3)-carene and total monoterpenes due to multicollinearity) of needles was also a significant factor. While A. ater did not select seedlings on the basis of family, seedlings not eaten were significantly higher in levels of alpha-pinene compared to seedlings that were consumed. We also demonstrated significant genetic variation in alpha-pinene concentration of seedlings between different families of P. sylvestris. Nitrogen and three morphological seedling characteristics (stem length, needle length and stem diameter) also showed significant genetic variation between P. sylvestris families. Artificial diets laced with high (5 mg g(-1) dry matter) quantities of either Delta(3)-carene or alpha-pinene, were eaten significantly less than control diets with no added monoterpenes, supporting the results of the seedling feeding trial. This study demonstrates that A. ater selectively feed on P. sylvestris seedlings and that this selection is based, in part, on the monoterpene concentration of seedlings. These results, coupled with significant genetic variation in alpha-pinene concentration of seedlings and evidence that slug herbivory is detrimental to P. sylvestris fitness, are discussed as possible evidence for A

  4. Vertebrate pressure-gradient receivers.

    Science.gov (United States)

    Christensen-Dalsgaard, Jakob

    2011-03-01

    The eardrums of all terrestrial vertebrates (tetrapods) are connected through Eustachian tubes or interaural canals. In some of the animals, these connections create pressure-gradient directionality, an enhanced directionality by interaction of sound arriving at both sides of the eardrum and strongly dependent on interaural transmission attenuation. Even though the tympanic middle ear has originated independently in the major tetrapod groups, in each group the ancestral condition probably was that the two middle ears were exposed in the mouth cavity with relatively high interaural transmission. Recent vertebrates form a continuum from perfect interaural transmission (0 dB in a certain frequency band) and pronounced eardrum directionality (30-40 dB) in the lizards, over somewhat attenuated transmission and limited directionality in birds and frogs, to the strongly attenuated interaural transmission and functionally isolated pressure receiver ears in the mammals. Since some of the binaural interaction already takes place at the eardrum in animals with strongly coupled ears, producing enhanced interaural time and level differences, the subsequent neural processing may be simpler. In robotic simulations of lizards, simple binaural subtraction (EI cells, found in brainstem nuclei of both frogs and lizards) produces strongly lateralized responses that are sufficient for steering the animal robustly to sound sources.

  5. Effects of herbivory, nutrients, and reef protection on algal proliferation and coral growth on a tropical reef.

    Science.gov (United States)

    Rasher, Douglas B; Engel, Sebastian; Bonito, Victor; Fraser, Gareth J; Montoya, Joseph P; Hay, Mark E

    2012-05-01

    Maintaining coral reef resilience against increasing anthropogenic disturbance is critical for effective reef management. Resilience is partially determined by how processes, such as herbivory and nutrient supply, affect coral recovery versus macroalgal proliferation following disturbances. However, the relative effects of herbivory versus nutrient enrichment on algal proliferation remain debated. Here, we manipulated herbivory and nutrients on a coral-dominated reef protected from fishing, and on an adjacent macroalgal-dominated reef subject to fishing and riverine discharge, over 152 days. On both reefs, herbivore exclusion increased total and upright macroalgal cover by 9-46 times, upright macroalgal biomass by 23-84 times, and cyanobacteria cover by 0-27 times, but decreased cover of encrusting coralline algae by 46-100% and short turf algae by 14-39%. In contrast, nutrient enrichment had no effect on algal proliferation, but suppressed cover of total macroalgae (by 33-42%) and cyanobacteria (by 71% on the protected reef) when herbivores were excluded. Herbivore exclusion, but not nutrient enrichment, also increased sediment accumulation, suggesting a strong link between herbivory, macroalgal growth, and sediment retention. Growth rates of the corals Porites cylindrica and Acropora millepora were 30-35% greater on the protected versus fished reef, but nutrient and herbivore manipulations within a site did not affect coral growth. Cumulatively, these data suggest that herbivory rather than eutrophication plays the dominant role in mediating macroalgal proliferation, that macroalgae trap sediments that may further suppress herbivory and enhance macroalgal dominance, and that corals are relatively resistant to damage from some macroalgae but are significantly impacted by ambient reef condition.

  6. Seasonal regulation of herbivory and nutrient effects on macroalgal recruitment and succession in a Florida coral reef

    Directory of Open Access Journals (Sweden)

    Alain Duran

    2016-11-01

    Full Text Available Herbivory and nutrient enrichment are drivers of benthic dynamics of coral reef macroalgae; however, their impact may vary seasonally. In this study we evaluated the effects of herbivore pressure, nutrient availability and potential propagule supply on seasonal recruitment and succession of macroalgal communities on a Florida coral reef. Recruitment tiles, replaced every three months, and succession tiles, kept in the field for nine months, were established in an ongoing factorial nutrient enrichment-herbivore exclusion experiment. The ongoing experiment had already created very different algal communities across the different herbivory and nutrient treatments. We tracked algal recruitment, species richness, and species abundance through time. Our results show seasonal variation in the effect of herbivory and nutrient availability on recruitment of coral reef macroalgae. In the spring, when there was higher macroalgal species richness and abundance of recruits, herbivory appeared to have more control on macroalgal community structure than did nutrients. In contrast, there was no effect of either herbivory or nutrient enrichment on macroalgal communities on recruitment tiles in cooler seasons. The abundance of recruits on tiles was positively correlated with the abundance of algal in the ongoing, established experiment, suggesting that propagule abundance is likely a strong influence on algal recruitment and early succession. Results of the present study suggest that abundant herbivorous fishes control recruitment and succession of macroalgae, particularly in the warm season when macroalgal growth is higher. However, herbivory appears less impactful on algal recruitment and community dynamics in cooler seasons. Ultimately, our data suggest that the timing of coral mortality (e.g., summer vs. winter mortality and freeing of benthic space may strongly influence the dynamics of algae that colonize open space.

  7. Evolutionary Specialization of Tactile Perception in Vertebrates.

    Science.gov (United States)

    Schneider, Eve R; Gracheva, Elena O; Bagriantsev, Slav N

    2016-05-01

    Evolution has endowed vertebrates with the remarkable tactile ability to explore the world through the perception of physical force. Yet the sense of touch remains one of the least well understood senses at the cellular and molecular level. Vertebrates specializing in tactile perception can highlight general principles of mechanotransduction. Here, we review cellular and molecular adaptations that underlie the sense of touch in typical and acutely mechanosensitive vertebrates.

  8. Avascular necrosis of a vertebral body

    Institute of Scientific and Technical Information of China (English)

    HUANG Sheng-li; SHI Wei; HE Xi-jing

    2009-01-01

    @@ Avascular necrosis of a vertebral body,a relatively uncommon entity,is caused by malicgnancy,infection,radiation,systemic stemid treatment,trauma,and the ike.1 Vertebral osteonecrosis induced by trauma is called Kümmell's disease,because it was initially described by Hermann KLimmell of Germany in 1891.2 This paper reported a young female with posttraumatic vertebral osteonecrosis and analyzed the causes.She was treated by thoracoscopic Surgery successfully.

  9. What is the general action of ghrelin for vertebrates? - comparisons of ghrelin's effects across vertebrates.

    Science.gov (United States)

    Kaiya, Hiroyuki; Kangawa, Kenji; Miyazato, Mikiya

    2013-01-15

    Ten years and more passed since ghrelin was discovered. Various physiological actions of ghrelin have been documented in both mammalian and nonmammalian vertebrates. Do these actions have any commonality? In this review, we focused on several effects of ghrelin, and compared the effect across vertebrates. We would like to discuss possible general function of ghrelin in vertebrates.

  10. Third-generation percutaneous vertebral augmentation systems

    Science.gov (United States)

    Galzio, Renato; Kazakova, Anna; Pantalone, Andrea; Grillea, Giovanni; Bartolo, Marcello; Salini, Vincenzo; Magliani, Vincenzo

    2016-01-01

    Currently, there is no general consensus about the management of osteoporotic vertebral fractures (OVF). In the past, conservative treatment for at least one month was deemed appropriate for the majority of vertebral fractures. When pain persisted after conservative treatment, it was necessary to consider surgical interventions including: vertebroplasty for vertebral fractures with less than 30% loss of height of the affected vertebral body and kyphoplasty for vertebral fractures with greater than 30% loss of height. Currently, this type of treatment is not feasible. Herein we review the characteristics and methods of operation of three of the most common percutaneous vertebral augmentation systems (PVAS) for the treatment of OVF: Vertebral Body Stenting® (VBS), OsseoFix® and Spine Jack®. VBS is a titanium device accompanied by a hydraulic (as opposed to mechanical) working system which allows a partial and not immediate possibility to control the opening of the device. On the other hand, OsseoFix® and Spine Jack® are accompanied by a mechanical working system which allows a progressive and controlled reduction of the vertebral fracture. Another important aspect to consider is the vertebral body height recovery. OsseoFix® has an indirect mechanism of action: the compaction of the trabecular bone causes an increase in the vertebral body height. Unlike the Vertebral Body Stenting® and Spine Jack®, the OsseoFix® has no direct lift mechanism. Therefore, for these characteristics and for the force that this device is able to provide. In our opinion, Spine Jack® is the only device also suitable for the treatment OVF, traumatic fracture (recent, old or inveterate) and primary or secondary bone tumors. PMID:27683690

  11. Vertebral Geometry Parameters Can Predict Fractures

    Directory of Open Access Journals (Sweden)

    P Tofighi

    2007-08-01

    Full Text Available Background: The aim of this study was to investigate vertebral geometry changes and determine cutoff value of vertebral height to predict fractures. Methods: In a cross-sectional study, 280 postmenopausal women recruited .In all subjects bone mineral density and radiog¬raphy of the lumbar spine performed. Lateral radiographs were evaluated for identification of vertebral fractures, using a validated semiquantitative method. T-score of vertebral height was calculated based on data extracted from Iranian Multi¬center Osteoporosis Study. ROC curve used to determine cut off value of vertebral height T-score to predict fractures. Results: The mean of age and BMI were 55.34±8.7 years and 27.73±5 kg/m2, respectively. Among osteoporotic women, 59.8% had one or more vertebral fractures and 23.8% had at least 2 fractures. In fracture group the T-score of spine and femur BMD was lower than the others. The mean of vertebral height in women without fractures was 12.94±0.6 cm, and in the patient with 4 or more fractures was12.3, thus every fracture accompany with 1.2% decreases in the height of vertebrae. The prevalence of vertebral fracture in osteoporotic patients was 71.4% and in healthy cases 39.5%. Better estimation of vertebral height T score in ROC curve was less than -0.7.The sensitivity and specificity of the cut off value were 81.3% and 52.9%, respectively. Conclusion: Vertebral fractures are common fractures in postmenopausal women. There was a correlation between verte¬bral height and fractures. Vertebral geometric parameters especially height T score can be used for fracture screening.

  12. Building the backbone: the development and evolution of vertebral patterning.

    Science.gov (United States)

    Fleming, Angeleen; Kishida, Marcia G; Kimmel, Charles B; Keynes, Roger J

    2015-05-15

    The segmented vertebral column comprises a repeat series of vertebrae, each consisting of two key components: the vertebral body (or centrum) and the vertebral arches. Despite being a defining feature of the vertebrates, much remains to be understood about vertebral development and evolution. Particular controversy surrounds whether vertebral component structures are homologous across vertebrates, how somite and vertebral patterning are connected, and the developmental origin of vertebral bone-mineralizing cells. Here, we assemble evidence from ichthyologists, palaeontologists and developmental biologists to consider these issues. Vertebral arch elements were present in early stem vertebrates, whereas centra arose later. We argue that centra are homologous among jawed vertebrates, and review evidence in teleosts that the notochord plays an instructive role in segmental patterning, alongside the somites, and contributes to mineralization. By clarifying the evolutionary relationship between centra and arches, and their varying modes of skeletal mineralization, we can better appreciate the detailed mechanisms that regulate and diversify vertebral patterning.

  13. Emerging role of roots in plant responses to aboveground insect herbivory

    Institute of Scientific and Technical Information of China (English)

    Vamsi J.Nalam; Jyoti Shah; Punya Nachappa

    2013-01-01

    Plants have evolved complex biochemical mechanisms to counter threats from insect herbivory.Recent research has revealed an important role of roots in plant responses to above ground herbivory (AGH).The involvement of roots is integral to plant resistance and tolerance mechanisms.Roots not only play an active role in plant defenses by acting as sites for biosynthesis of various toxins and but also contribute to tolerance by storing photoassimilates to enable future regrowth.The interaction of roots with beneficial soilborne microorganisms also influences the outcome of the interaction between plant and insect herbivores.Shoot-to-root communication signals are critical for plant response to AGH.A better understanding of the role of roots in plant response to AGH is essential in order to develop a comprehensive picture of plant-insect interactions.Here,we summarize the current status of research on the role of roots in plant response to AGH and also discuss possible signals involved in shoot-to-root communication.

  14. Risk of spider predation alters food web structure and reduces local herbivory in the field.

    Science.gov (United States)

    Bucher, Roman; Menzel, Florian; Entling, Martin H

    2015-06-01

    Predators can indirectly enhance plant performance via herbivore suppression, with both prey consumption and changes in prey traits (e.g. changes in foraging behaviour) contributing to the reduction in herbivory. We performed a field experiment to determine the extent of such non-consumptive effects which consisted of repeatedly placing spiders (Pisaura mirabilis) on enclosed plants (Urtica dioica) for cue deposition. Control plants were enclosed in the same way but without spiders. After cue deposition, the enclosures were removed to allow arthropods to colonize the plants and feed on them. Arthropods were removed from the plants before the subsequent spider deposition or control enclosure. During six cycles of enclosure, we quantified leaf damage on the plants. After a seventh cycle, the colonizing arthropods were sampled to determine community composition in relation to the presence/absence of spider cues. We found that the presence of chemotactile spider cues reduced leaf damage by 50 %. In addition, spider cues led to changes in the arthropod community: smaller spiders avoided plants with spider cues. In contrast, the aphid-tending ant Myrmica rubra showed higher recruitment of workers on cue-bearing plants, possibly to protect aphids. Our results show that the risk of spider predation can reduce herbivory on wild plants and also demonstrate that non-consumptive effects can be particularly strong within the predator guild.

  15. Fifty million years of herbivory on coral reefs: fossils, fish and functional innovations

    Science.gov (United States)

    Bellwood, D. R.; Goatley, C. H. R.; Brandl, S. J.; Bellwood, O.

    2014-01-01

    The evolution of ecological processes on coral reefs was examined based on Eocene fossil fishes from Monte Bolca, Italy and extant species from the Great Barrier Reef, Australia. Using ecologically relevant morphological metrics, we investigated the evolution of herbivory in surgeonfishes (Acanthuridae) and rabbitfishes (Siganidae). Eocene and Recent surgeonfishes showed remarkable similarities, with grazers, browsers and even specialized, long-snouted forms having Eocene analogues. These long-snouted Eocene species were probably pair-forming, crevice-feeding forms like their Recent counterparts. Although Eocene surgeonfishes likely played a critical role as herbivores during the origins of modern coral reefs, they lacked the novel morphologies seen in modern Acanthurus and Siganus (including eyes positioned high above their low-set mouths). Today, these forms dominate coral reefs in both abundance and species richness and are associated with feeding on shallow, exposed algal turfs. The radiation of these new forms, and their expansion into new habitats in the Oligocene–Miocene, reflects the second phase in the development of fish herbivory on coral reefs that is closely associated with the exploitation of highly productive short algal turfs. PMID:24573852

  16. Seagrass (Posidonia oceanica) seedlings in a high-CO2 world: from physiology to herbivory

    KAUST Repository

    Hernán, Gema

    2016-12-01

    Under future increased CO2 concentrations, seagrasses are predicted to perform better as a result of increased photosynthesis, but the effects in carbon balance and growth are unclear and remain unexplored for early life stages such as seedlings, which allow plant dispersal and provide the potential for adaptation under changing environmental conditions. Furthermore, the outcome of the concomitant biochemical changes in plant-herbivore interactions has been poorly studied, yet may have important implications in plant communities. In this study we determined the effects of experimental exposure to current and future predicted CO2 concentrations on the physiology, size and defense strategies against herbivory in the earliest life stage of the Mediterranean seagrass Posidonia oceanica. The photosynthetic performance of seedlings, assessed by fluorescence, improved under increased pCO2 conditions after 60 days, although these differences disappeared after 90 days. Furthermore, these plants exhibited bigger seeds and higher carbon storage in belowground tissues, having thus more resources to tolerate and recover from stressors. Of the several herbivory resistance traits measured, plants under high pCO2 conditions had a lower leaf N content but higher sucrose. These seedlings were preferred by herbivorous sea urchins in feeding trials, which could potentially counteract some of the positive effects observed.

  17. Lobelia siphilitica plants that escape herbivory in time also have reduced latex production.

    Directory of Open Access Journals (Sweden)

    Amy L Parachnowitsch

    Full Text Available Flowering phenology is an important determinant of a plant's reproductive success. Both assortative mating and niche construction can result in the evolution of correlations between phenology and other reproductive, functional, and life history traits. Correlations between phenology and herbivore defence traits are particularly likely because the timing of flowering can allow a plant to escape herbivory. To test whether herbivore escape and defence are correlated, we estimated phenotypic and genetic correlations between flowering phenology and latex production in greenhouse-grown Lobelia siphilitica L. (Lobeliaceae. Lobelia siphilitica plants that flower later escape herbivory by a specialist pre-dispersal seed predator, and thus should invest fewer resources in defence. Consistent with this prediction, we found that later flowering was phenotypically and genetically correlated with reduced latex production. To test whether herbivore escape and latex production were costly, we also measured four fitness correlates. Flowering phenology was negatively genetically correlated with three out of four fitness estimates, suggesting that herbivore escape can be costly. In contrast, we did not find evidence for costs of latex production. Generally, our results suggest that herbivore escape and defence traits will not evolve independently in L. siphilitica.

  18. Seagrass (Posidonia oceanica) seedlings in a high-CO2 world: from physiology to herbivory

    Science.gov (United States)

    Hernán, Gema; Ramajo, Laura; Basso, Lorena; Delgado, Antonio; Terrados, Jorge; Duarte, Carlos M.; Tomas, Fiona

    2016-01-01

    Under future increased CO2 concentrations, seagrasses are predicted to perform better as a result of increased photosynthesis, but the effects in carbon balance and growth are unclear and remain unexplored for early life stages such as seedlings, which allow plant dispersal and provide the potential for adaptation under changing environmental conditions. Furthermore, the outcome of the concomitant biochemical changes in plant-herbivore interactions has been poorly studied, yet may have important implications in plant communities. In this study we determined the effects of experimental exposure to current and future predicted CO2 concentrations on the physiology, size and defense strategies against herbivory in the earliest life stage of the Mediterranean seagrass Posidonia oceanica. The photosynthetic performance of seedlings, assessed by fluorescence, improved under increased pCO2 conditions after 60 days, although these differences disappeared after 90 days. Furthermore, these plants exhibited bigger seeds and higher carbon storage in belowground tissues, having thus more resources to tolerate and recover from stressors. Of the several herbivory resistance traits measured, plants under high pCO2 conditions had a lower leaf N content but higher sucrose. These seedlings were preferred by herbivorous sea urchins in feeding trials, which could potentially counteract some of the positive effects observed. PMID:27905514

  19. A new North American therizinosaurid and the role of herbivory in 'predatory' dinosaur evolution.

    Science.gov (United States)

    Zanno, Lindsay E; Gillette, David D; Albright, L Barry; Titus, Alan L

    2009-10-07

    Historically, ecomorphological inferences regarding theropod (i.e. 'predatory') dinosaurs were guided by an assumption that they were singularly hypercarnivorous. A recent plethora of maniraptoran discoveries has produced evidence challenging this notion. Here, we report on a new species of maniraptoran theropod, Nothronychus graffami sp. nov. Relative completeness of this specimen permits a phylogenetic reassessment of Therizinosauria-the theropod clade exhibiting the most substantial anatomical evidence of herbivory. In the most comprehensive phylogenetic study of the clade conducted to date, we recover Therizinosauria as the basalmost maniraptoran lineage. Using concentrated changes tests, we present evidence for correlated character evolution among herbivorous and hypercarnivorous taxa and propose ecomorphological indicators for future interpretations of diet among maniraptoran clades. Maximum parsimony optimizations of character evolution within our study indicate an ancestral origin for dietary plasticity and facultative herbivory (omnivory) within the clade. These findings suggest that hypercarnivory in paravian dinosaurs is a secondarily derived dietary specialization and provide a potential mechanism for the invasion of novel morpho- and ecospace early in coelurosaurian evolution-the loss of obligate carnivory and origin of dietary opportunism.

  20. High-altitude adaptations in vertebrate hemoglobins

    DEFF Research Database (Denmark)

    Weber, Roy E.

    2007-01-01

    Vertebrates at high altitude are subjected to hypoxic conditions that challenge aerobic metabolism. O2 transport from the respiratory surfaces to tissues requires matching between the O2 loading and unloading tensions and theO2-affinity of blood, which is an integrated function of hemoglobin......, birds and ectothermic vertebrates at high altitude....

  1. The evolution of adaptive immunity in vertebrates.

    Science.gov (United States)

    Hirano, Masayuki; Das, Sabyasachi; Guo, Peng; Cooper, Max D

    2011-01-01

    Approximately 500 million years ago, two types of recombinatorial adaptive immune systems (AISs) arose in vertebrates. The jawed vertebrates diversify their repertoire of immunoglobulin domain-based T and B cell antigen receptors mainly through the rearrangement of V(D)J gene segments and somatic hypermutation, but none of the fundamental AIS recognition elements in jawed vertebrates have been found in jawless vertebrates. Instead, the AIS of jawless vertebrates is based on variable lymphocyte receptors (VLRs) that are generated through recombinatorial usage of a large panel of highly diverse leucine-rich-repeat (LRR) sequences. Whereas the appearance of transposon-like, recombination-activating genes contributed uniquely to the origin of the AIS in jawed vertebrates, the use of activation-induced cytidine deaminase for receptor diversification is common to both the jawed and jawless vertebrates. Despite these differences in anticipatory receptor construction, the basic AIS design featuring two interactive T and B lymphocyte arms apparently evolved in an ancestor of jawed and jawless vertebrates within the context of preexisting innate immunity and has been maintained since as a consequence of powerful and enduring selection, most probably for pathogen defense purposes.

  2. Vertebral osteomyelitis: clinical features and diagnosis.

    Science.gov (United States)

    Eren Gök, S; Kaptanoğlu, E; Celikbaş, A; Ergönül, O; Baykam, N; Eroğlu, M; Dokuzoğuz, B

    2014-10-01

    We aimed to describe clinical and diagnostic features of vertebral osteomyelitis for differential diagnosis and treatment. This is a prospective observational study performed between 2002 and 2012 in Ankara Numune Education and Research Hospital in Ankara, Turkey. All the patients with vertebral osteomyelitis were followed for from 6 months to 3 years. In total, 214 patients were included in the study, 113 out of 214 (53%) were female. Out of 214 patients, 96 (45%) had brucellar vertebral osteomyelitis (BVO), 63 (29%) had tuberculous vertebral osteomyelitis (TVO), and 55 (26%) had pyogenic vertebral osteomyelitis (PVO). Mean number of days between onset of symptoms and establishment of diagnosis was greater with the patients with TVO (266 days) than BVO (115 days) or PVO (151 days, p 15 mm, sensitivity was 0.66, specificity was 0.97, positive predictive value was 0.89, negative predictive value was 0.88, and receiver operating characteristics area was 0.8. Tuberculous and brucellar vertebral osteomyelitis remained the leading causes of vertebral osteomyelitis with delayed diagnosis. In differential diagnosis of vertebral osteomyelitis, consumption of unpasteurized cheese, dealing with husbandry, sweating, arthralgia, hepatomegaly, elevated alanine transaminase, and lumbar involvement in magnetic resonance imaging were found to be predictors of BVO, thoracic involvement in magnetic resonance imaging and tuberculin skin test > 15 mm were found to be predictors of TVO, and history of spinal surgery and leucocytosis were found to be predictors of PVO.

  3. Nanotechnology for treating osteoporotic vertebral fractures.

    Science.gov (United States)

    Gao, Chunxia; Wei, Donglei; Yang, Huilin; Chen, Tao; Yang, Lei

    2015-01-01

    Osteoporosis is a serious public health problem affecting hundreds of millions of aged people worldwide, with severe consequences including vertebral fractures that are associated with significant morbidity and mortality. To augment or treat osteoporotic vertebral fractures, a number of surgical approaches including minimally invasive vertebroplasty and kyphoplasty have been developed. However, these approaches face problems and difficulties with efficacy and long-term stability. Recent advances and progress in nanotechnology are opening up new opportunities to improve the surgical procedures for treating osteoporotic vertebral fractures. This article reviews the improvements enabled by new nanomaterials and focuses on new injectable biomaterials like bone cements and surgical instruments for treating vertebral fractures. This article also provides an introduction to osteoporotic vertebral fractures and current clinical treatments, along with the rationale and efficacy of utilizing nanomaterials to modify and improve biomaterials or instruments. In addition, perspectives on future trends with injectable bone cements and surgical instruments enhanced by nanotechnology are provided.

  4. Interaction Effect Between Herbivory and Plant Fertilization on Extrafloral Nectar Production and on Seed Traits: An Experimental Study With Ricinus communis (Euphorbiaceae).

    Science.gov (United States)

    De Sibio, P R; Rossi, M N

    2016-08-01

    It is known that the release of volatile chemicals by many plants can attract the natural enemies of herbivorous insects. Such indirect interactions are likely when plants produce nectar from their extrafloral nectaries, and particularly when the production of extrafloral nectar (EFN) is induced by herbivory. In the present study, we conducted experiments to test whether foliar herbivory inflicted by Spodoptera frugiperda Smith (Noctuidae) increases nectar production by extrafloral nectaries on one of its host plants, Ricinus communis L. (Euphorbiaceae). Due to the current economic importance of R. communis, we also investigated whether the following seed traits-water content, dry mass, and essential oil production-are negatively affected by herbivory. Finally, we tested whether or not nectar production and seed traits are influenced by plant fertilization (plant quality). We found that nectar production was increased after herbivory, but it was not affected by the type of fertilization. Seed dry mass was higher in plants that were subjected to full fertilization, without herbivory; plants maintained in low fertilization conditions, however, had higher seed mass when subjected to herbivory. The same inverted pattern was observed for oil production. Therefore, our results suggest that EFN production in R. communis may act as an indirect defense strategy against herbivores, and that there is a trade-off between reproduction and plant growth when low-fertilized plants are subjected to herbivory.

  5. Leaf-fracture properties correlated with nutritional traits in nine Australian seagrass species: implications for susceptibility to herbivory

    NARCIS (Netherlands)

    de los Santos, C.B.; Brun, F.G.; Onoda, Y.; Cambridge, M.L.; Bouma, T.J.; Vergara, J.J.; Pérez-Lloréns, J.L.

    2012-01-01

    Seagrasses are exposed to the constant risk of structural damage due to abiotic factors, such as waves and currents, and biotic factors, e. g. herbivory. Leaf mechanical resistance is therefore essential in protecting plants from structural failure and may also have ecological consequences. For exam

  6. Sugarcane Serine Peptidase Inhibitors, Serine Peptidases, and Clp Protease System Subunits Associated with Sugarcane Borer (Diatraea saccharalis) Herbivory and Wounding

    Science.gov (United States)

    Medeiros, Ane H.; Mingossi, Fabiana B.; Dias, Renata O.; Franco, Flávia P.; Vicentini, Renato; Mello, Marcia O.; Moura, Daniel S.; Silva-Filho, Marcio C.

    2016-01-01

    Sugarcane’s (Saccharum spp.) response to Diatraea saccharalis (F.) (Lepidoptera: (Crambidae) herbivory was investigated using a macroarray spotted with 248 sugarcane Expressed Sequence Tags (ESTs) encoding serine peptidase inhibitors, serine peptidases. and Clp protease system subunits. Our results showed that after nine hours of herbivory, 13 sugarcane genes were upregulated and nine were downregulated. Among the upregulated genes, nine were similar to serine peptidase inhibitors and four were similar to Bowman-Birk Inhibitors (BBIs). Phylogenetic analysis revealed that these sequences belong to a phylogenetic group of sugarcane BBIs that are potentially involved in plant defense against insect predation. The remaining four upregulated genes included serine peptidases and one homolog to the Arabidopsis AAA+ chaperone subunit ClpD, which is a member of the Clp protease system. Among the downregulated genes, five were homologous to serine peptidases and four were homologous to Arabidopsis Clp subunits (three homologous to Clp AAA+ chaperones and one to a ClpP-related ClpR subunit). Although the roles of serine peptidase inhibitors in plant defenses against herbivory have been extensively investigated, the roles of plant serine peptidases and the Clp protease system represent a new and underexplored field of study. The up- and downregulated D. saccharalis genes presented in this study may be candidate genes for the further investigation of the sugarcane response to herbivory. PMID:27598134

  7. Mitotic chromosome condensation in vertebrates

    Energy Technology Data Exchange (ETDEWEB)

    Vagnarelli, Paola, E-mail: P.Vagnarelli@ed.ac.uk

    2012-07-15

    Work from several laboratories over the past 10-15 years has revealed that, within the interphase nucleus, chromosomes are organized into spatially distinct territories [T. Cremer, C. Cremer, Chromosome territories, nuclear architecture and gene regulation in mammalian cells, Nat. Rev. Genet. 2 (2001) 292-301 and T. Cremer, M. Cremer, S. Dietzel, S. Muller, I. Solovei, S. Fakan, Chromosome territories-a functional nuclear landscape, Curr. Opin. Cell Biol. 18 (2006) 307-316]. The overall compaction level and intranuclear location varies as a function of gene density for both entire chromosomes [J.A. Croft, J.M. Bridger, S. Boyle, P. Perry, P. Teague,W.A. Bickmore, Differences in the localization and morphology of chromosomes in the human nucleus, J. Cell Biol. 145 (1999) 1119-1131] and specific chromosomal regions [N.L. Mahy, P.E. Perry, S. Gilchrist, R.A. Baldock, W.A. Bickmore, Spatial organization of active and inactive genes and noncoding DNA within chromosome territories, J. Cell Biol. 157 (2002) 579-589] (Fig. 1A, A'). In prophase, when cyclin B activity reaches a high threshold, chromosome condensation occurs followed by Nuclear Envelope Breakdown (NEB) [1]. At this point vertebrate chromosomes appear as compact structures harboring an attachment point for the spindle microtubules physically recognizable as a primary constriction where the two sister chromatids are held together. The transition from an unshaped interphase chromosome to the highly structured mitotic chromosome (compare Figs. 1A and B) has fascinated researchers for several decades now; however a definite picture of how this process is achieved and regulated is not yet in our hands and it will require more investigation to comprehend the complete process. From a biochemical point of view a vertebrate mitotic chromosomes is composed of DNA, histone proteins (60%) and non-histone proteins (40%) [6]. I will discuss below what is known to date on the contribution of these two different classes

  8. Sapling herbivory, invertebrate herbivores and predators across a natural tree diversity gradient in Germany's largest connected deciduous forest.

    Science.gov (United States)

    Sobek, Stephanie; Scherber, Christoph; Steffan-Dewenter, Ingolf; Tscharntke, Teja

    2009-05-01

    Tree species-rich forests are hypothesised to be less susceptible to insect herbivores, but so far herbivory-diversity relationships have rarely been tested for tree saplings, and no such study has been published for deciduous forests in Central Europe. We expected that diverse tree communities reduce the probability of detection of host plants and increase abundance of predators, thereby reducing herbivory. We examined levels of herbivory suffered by beech (Fagus sylvatica L.) and maple saplings (Acer pseudoplatanus L. and Acer platanoides L.) across a tree species diversity gradient within Germany's largest remaining deciduous forest area, and investigated whether simple beech or mixed stands were less prone to damage caused by herbivorous insects. Leaf area loss and the frequency of galls and mines were recorded for 1,040 saplings (>13,000 leaves) in June and August 2006. In addition, relative abundance of predators was assessed to test for potential top-down control. Leaf area loss was generally higher in the two species of maple compared to beech saplings, while only beech showed a decline in damage caused by leaf-chewing herbivores across the tree diversity gradient. No significant patterns were found for galls and mines. Relative abundance of predators on beech showed a seasonal response and increased on species-rich plots in June, suggesting higher biological control. We conclude that, in temperate deciduous forests, herbivory-tree diversity relationships are significant, but are tree species-dependent with bottom-up and top-down control as possible mechanisms. In contrast to maple, beech profits from growing in a neighbourhood of higher tree richness, which implies that species identity effects may be of greater importance than tree diversity effects per se. Hence, herbivory on beech appeared to be mediated bottom-up by resource concentration in the sampled forest stands, as well as regulated top-down through biocontrol by natural enemies.

  9. Among-population variation in tolerance to larval herbivory by Anthocharis cardamines in the polyploid herb Cardamine pratensis.

    Directory of Open Access Journals (Sweden)

    Malin A E König

    Full Text Available Plants have two principal defense mechanisms to decrease fitness losses to herbivory: tolerance, the ability to compensate fitness after damage, and resistance, the ability to avoid damage. Variation in intensity of herbivory among populations should result in variation in plant defense levels if tolerance and resistance are associated with costs. Yet little is known about how levels of tolerance are related to resistance and attack intensity in the field, and about the costs of tolerance. In this study, we used information about tolerance and resistance against larval herbivory by the butterfly Anthocharis cardamines under controlled conditions together with information about damage in the field for a large set of populations of the perennial plant Cardamine pratensis. Plant tolerance was estimated in a common garden experiment where plants were subjected to a combination of larval herbivory and clipping. We found no evidence of that the proportion of damage that was caused by larval feeding vs. clipping influenced plant responses. Damage treatments had a negative effect on the three measured fitness components and also resulted in an earlier flowering in the year after the attack. Tolerance was related to attack intensity in the population of origin, i.e. plants from populations with higher attack intensity were more likely to flower in the year following damage. However, we found no evidence of a relationship between tolerance and resistance. These results indicate that herbivory drives the evolution for increased tolerance, and that changes in tolerance are not linked to changes in resistance. We suggest that the simultaneous study of tolerance, attack intensity in the field and resistance constitutes a powerful tool to understand how plant strategies to avoid negative effects of herbivore damage evolve.

  10. Organizational heterogeneity of vertebrate genomes.

    Directory of Open Access Journals (Sweden)

    Svetlana Frenkel

    Full Text Available Genomes of higher eukaryotes are mosaics of segments with various structural, functional, and evolutionary properties. The availability of whole-genome sequences allows the investigation of their structure as "texts" using different statistical and computational methods. One such method, referred to as Compositional Spectra (CS analysis, is based on scoring the occurrences of fixed-length oligonucleotides (k-mers in the target DNA sequence. CS analysis allows generating species- or region-specific characteristics of the genome, regardless of their length and the presence of coding DNA. In this study, we consider the heterogeneity of vertebrate genomes as a joint effect of regional variation in sequence organization superimposed on the differences in nucleotide composition. We estimated compositional and organizational heterogeneity of genome and chromosome sequences separately and found that both heterogeneity types vary widely among genomes as well as among chromosomes in all investigated taxonomic groups. The high correspondence of heterogeneity scores obtained on three genome fractions, coding, repetitive, and the remaining part of the noncoding DNA (the genome dark matter--GDM allows the assumption that CS-heterogeneity may have functional relevance to genome regulation. Of special interest for such interpretation is the fact that natural GDM sequences display the highest deviation from the corresponding reshuffled sequences.

  11. Melatonin Receptor Genes in Vertebrates

    Directory of Open Access Journals (Sweden)

    Hua Dong Yin

    2013-05-01

    Full Text Available Melatonin receptors are members of the G protein-coupled receptor (GPCR family. Three genes for melatonin receptors have been cloned. The MT1 (or Mel1a or MTNR1A and MT2 (or Mel1b or MTNR1B receptor subtypes are present in humans and other mammals, while an additional melatonin receptor subtype, Mel1c (or MTNR1C, has been identified in fish, amphibians and birds. Another melatonin related orphan receptor, GPR50, which does not bind melatonin, is found exclusively in mammals. The hormone melatonin is secreted primarily by the pineal gland, with highest levels occurring during the dark period of a circadian cycle. This hormone acts systemically in numerous organs. In the brain, it is involved in the regulation of various neural and endocrine processes, and it readjusts the circadian pacemaker, the suprachiasmatic nucleus. This article reviews recent studies of gene organization, expression, evolution and mutations of melatonin receptor genes of vertebrates. Gene polymorphisms reveal that numerous mutations are associated with diseases and disorders. The phylogenetic analysis of receptor genes indicates that GPR50 is an outgroup to all other melatonin receptor sequences. GPR50 may have separated from a melatonin receptor ancestor before the split between MTNR1C and the MTNR1A/B ancestor.

  12. Antibody Isotype Switching in Vertebrates.

    Science.gov (United States)

    Senger, Kate; Hackney, Jason; Payandeh, Jian; Zarrin, Ali A

    2015-01-01

    The humoral or antibody-mediated immune response in vertebrates has evolved to respond to diverse antigenic challenges in various anatomical locations. Diversification of the immunoglobulin heavy chain (IgH) constant region via isotype switching allows for remarkable plasticity in the immune response, including versatile tissue distribution, Fc receptor binding, and complement fixation. This enables antibody molecules to exert various biological functions while maintaining antigen-binding specificity. Different immunoglobulin (Ig) classes include IgM, IgD, IgG, IgE, and IgA, which exist as surface-bound and secreted forms. High-affinity autoantibodies are associated with various autoimmune diseases such as lupus and arthritis, while defects in components of isotype switching are associated with infections. A major route of infection used by a large number of pathogens is invasion of mucosal surfaces within the respiratory, digestive, or urinary tract. Most infections of this nature are initially limited by effector mechanisms such as secretory IgA antibodies. Mucosal surfaces have been proposed as a major site for the genesis of adaptive immune responses, not just in fighting infections but also in tolerating commensals and constant dietary antigens. We will discuss the evolution of isotype switching in various species and provide an overview of the function of various isotypes with a focus on IgA, which is universally important in gut homeostasis as well as pathogen clearance. Finally, we will discuss the utility of antibodies as therapeutic modalities.

  13. Chemical defenses of the tropical marine seaweed Canistrocarpus cervicornis against herbivory by sea urchin

    Directory of Open Access Journals (Sweden)

    Éverson Miguel Bianco

    2010-09-01

    Full Text Available This paper reports on the defensive chemical properties of the marine tropical brown seaweed Canistrocarpus cervicornis against herbivory. A natural concentration of dichloromethane crude extract (DCE obtained from this seaweed significantly inhibited feeding by the sea urchin Lytechinus variegatus. The major metabolite isolated from this active DCE extract was identified as the (4R,7R,14S-4α,7α-diacetoxy-14-hydroxydolast-1(15,8-diene that strongly inhibited feeding by the same sea urchin. This result suggests that the dolastane diterpenes class may constitute the defensive system of C. cervicornis against herbivory, and probably also of that of other brown seaweeds endowed with a biosynthetic pathway capable of producing compounds of the dolastane-type, a typical skeleton found in Dyctioteae species worldwide. This is the first report showing this compound-type (dolastane diterpenes as a chemical defense against herbivory in marine seaweeds. This study constitutes an additional report broadening the known spectrum of action and roles of secondary metabolites of the C. cervicornis and Dyctioteae species.Este artigo demonstra a química defensiva anti-herbivoria da macroalga parda marinha Canistrocarpus cervicornis. Em sua concentração natural, o extrato bruto em diclorometano (DCE inibiu significativamente o consumo alimentar do ouriço-do-mar Lytechinus variegatus. Deste extrato em DCE foi isolado o metabólito majoritário identificado como o diterpeno (4R,7R,14S-4α,7α-diacetoxi-14-hidroxidolasta-1(15,8-dieno. Esses resultados comprovam que diterpenos da classe dolastano podem compor o sistema defensivo anti-herbivoria de C. cervircornis e, supostamente, o de outras algas pardas capazes de produzi-los, uma vez que são composto típicos encontrados em esqueletos de Dyctiotas em todo o mundo. Este é o primeiro estudo demonstrando a ação anti-herbivoria desta classe de metabolitos (diterpenos dolastanos em macroalgas marinhas. Tais

  14. Epidemiology of acute vertebral osteomyelitis in Denmark

    DEFF Research Database (Denmark)

    Krogsgaard, M R; Wagn, P; Bengtsson, J

    1998-01-01

    We studied the epidemiology of acute, non-tuberculous, hematogenous vertebral osteomyelitis in Denmark during 1978-1982. 137 patients fulfilled the criteria for acute vertebral osteomyelitis. The incidence was 5/mill/year. There were no cases in the age group 20-29 years. The highest incidence......-1993, the relative number of reported patients with vertebral osteomyelitis had increased in the age group 20-49 years, compared to 1978-1982, but the incidence was highest in the group aged 60-79 years....

  15. Pulmonary Embolism with Vertebral Augmentation Procedures

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    Swetha Bopparaju

    2013-01-01

    Full Text Available With the prevalence of an aging American population on the rise, osteoporotic vertebral fractures are becoming a common occurrence, resulting in an increase in vertebral augmentation procedures and associated complications such as cement leakage, vertebral compressions, and pulmonary embolism. We describe a patient who presented with respiratory distress three years following kyphoplasty of the lumbar vertebra. Computed tomography (CT angiogram of the chest confirmed the presence of polymethylmethacrylate (PMMA cement in the lung fields and pulmonary vessels. We conducted a systematic review of the published literature identifying effective management strategies for the treatment of vertebroplasty-associated pulmonary embolism.

  16. Segmental patterning of the vertebrate embryonic axis.

    Science.gov (United States)

    Dequéant, Mary-Lee; Pourquié, Olivier

    2008-05-01

    The body axis of vertebrates is composed of a serial repetition of similar anatomical modules that are called segments or metameres. This particular mode of organization is especially conspicuous at the level of the periodic arrangement of vertebrae in the spine. The segmental pattern is established during embryogenesis when the somites--the embryonic segments of vertebrates--are rhythmically produced from the paraxial mesoderm. This process involves the segmentation clock, which is a travelling oscillator that interacts with a maturation wave called the wavefront to produce the periodic series of somites. Here, we review our current understanding of the segmentation process in vertebrates.

  17. Herbivory and growth in terrestrial and aquatic populations of amphibious stream plants

    DEFF Research Database (Denmark)

    Sand-Jensen, Kaj; Jacobsen, Dean

    2002-01-01

    1. Many amphibious plant species grow in the transition between terrestrial and submerged vegetation in small lowland streams. We determined biomass development, leaf turnover rate and invertebrate herbivory during summer in terrestrial and aquatic populations of three amphibious species...... production (average 1.2-5.1%) than aquatic populations (2.9-17.3%), while the same plant dry mass was consumed per unit ground area. 3. Grazing loss increased linearly with leaf age apart from the youngest leaf stages. Grazing loss during the lifetime of leaves was therefore 2.4-3.1 times higher than mean...... apparent loss to standing leaves of all ages. The results imply that variation in density of grazers relative to plant production can account for differences in grazing impact between terrestrial and aquatic populations, and that fast leaf turnover keeps apparent grazing damage down. 4. We conclude...

  18. Ants visit nectaries of Epidendrum denticulatum (Orchidaceae in a Brazilian rainforest: effects on herbivory and pollination

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    A. M. Almeida

    Full Text Available Epidendrum denticulatum (Orchidaceae produces nectar on the petioles of buds, flowers, and fruits (extrafloral nectaries but no nectar is found on its flowers, and it is probably a deceptive species. In the Brazilian Atlantic rainforest, some aspects of both the ecology and behavior of Camponotus sericeiventris (Formicinae and Ectatomma tuberculatum (Ponerinae, two ant species foraging on E. denticulatum extrafloral nectaries, were investigated. Both experiments, using termites as baits and field observations, suggest that these ant species are able to prevent reproductive organ herbivory, without affecting pollinator behaviour. Since a low fruit set is often cited as a characteristic of the family, especially for deceptive species, ants attracted to orchid inflorescences protect reproductive structures and increase the probability of pollination success. Epidendrum denticulatum flowers were visited and probably pollinated by Heliconius erato (Nymphalidae and Euphyes leptosema (Hesperiidae.

  19. Effects of selenium accumulation on phytotoxicity, herbivory, and pollination ecology in radish (Raphanus sativus L.).

    Science.gov (United States)

    Hladun, Kristen R; Parker, David R; Tran, Khoa D; Trumble, John T

    2013-01-01

    Selenium (Se) has contaminated areas in the western USA where pollination is critical to the functioning of both agricultural and natural ecosystems, yet we know little about how Se can impact pollinators. In a two-year semi-field study, the weedy plant Raphanus sativus (radish) was exposed to three selenate treatments and two pollination treatments to evaluate the effects on pollinator-plant interactions. Honey bee (Apis mellifera L.) pollinators were observed to readily forage on R. sativus for both pollen and nectar despite high floral Se concentrations. Se treatment increased both seed abortion (14%) and decreased plant biomass (8-9%). Herbivory by birds and aphids was reduced on Se-treated plants, indicating a potential reproductive advantage for the plant. Our study sheds light on how pollutants such as Se can impact the pollination ecology of a plant that accumulates even moderate amounts of Se.

  20. [Osteocyte-network in various vertebrates].

    Science.gov (United States)

    Yamaguchi, Akira

    2012-05-01

    Since aquatic and land vertebrates live in different habitats,the morphology and function of bone might be greatly affected by the habitats of each vertebrate. We histologically investigated the bones of various vertebrates including teleost fishes, amphibians, reptiles, and mammals. Teleost fishes exhibited either bones contained many osteocytes (cellular bone) or bones have few osteocytes (acellular bone) . The development of osteocyte lacunocanalicular system in the cellular bone of the fish is poor compared to those in amphibians, reptiles, and mammals. Bones in Xenopus laevis, a freshwater species, exhibited well-developed lacunocanalicular systems as well as those in reptiles and mammals. These studies indicates that the osteocyte lacunocanalicular system differs between teleost fishes and land vertebrates, but this is not directly related to aquatic habitat.

  1. Interconnections between the Ears in Nonmammalian Vertebrates

    DEFF Research Database (Denmark)

    Feng, Albert S.; Christensen-Dalsgaard, J.

    2010-01-01

    Many of the nonmammalian vertebrates (anurans, lizards, crocodiles, and some bird species) have large, continuous air spaces connecting the middle ears and acoustically coupling the eardrums. Acoustical coupling leads to strongly enhanced directionality of the ear at frequencies where diffraction...

  2. Sleep and orexins in nonmammalian vertebrates.

    Science.gov (United States)

    Volkoff, Hélène

    2012-01-01

    Although a precise definition of "sleep" has yet to be established, sleep-like behaviors have been observed in all animals studied to date including mammals and nonmammalian vertebrates. Orexins are hypothalamic neuropeptides that are involved in the regulation of many physiological functions, including feeding, thermoregulation, cardiovascular control, as well as the control of the sleep-wakefulness cycle. To date, the knowledge on the functions of orexins in nonmammalian vertebrates is still limited, but the similarity of the structures of orexins and their receptors among vertebrates suggest that they have similar conserved physiological functions. This review describes our current knowledge on sleep in nonmammalian vertebrates (birds, reptiles, amphibians, and fish) and the possible role of orexins in the regulation of their energy homeostasis and arousal states.

  3. A Case of Aerococcus Urinae Vertebral Osteomyelitis

    Science.gov (United States)

    Jerome, Michael; Slim, Jihad; Sison, Raymund; Marton, Randy

    2015-01-01

    Aerococcus urinae is an aerobic, alpha hemolytic gram positive coccus bacterium that grows in pairs or clusters. We report the first case of vertebral osteomyelitis due to A. urinae. This has not been previously reported in the literature. PMID:26069429

  4. RFamide peptides in early vertebrate development

    Directory of Open Access Journals (Sweden)

    Guro Katrine Sandvik

    2014-12-01

    Full Text Available RFamides (RFa are neuropeptides involved in many different physiological processes in vertebrates, such as reproductive behavior, pubertal activation of the reproductive endocrine axis, control of feeding behavior, and pain modulation. As research has focused mostly on their role in adult vertebrates, the possible roles of these peptides during development are poorly understood. However, the few studies that exist show that RFa are expressed early in development in different vertebrate classes, perhaps mostly associated with the central nervous system. Interestingly, the related peptide family of FMRFa has been shown to be important for brain development in invertebrates. In a teleost, the Japanese medaka, knockdown of genes in the Kiss system indicates that Kiss ligands and receptors are vital for brain development, but few other functional studies exist. Here we review the literature of RFa in early vertebrate development, including the possible functional roles these peptides may play.

  5. Planar cell polarity signaling in vertebrates.

    Science.gov (United States)

    Jones, Chonnettia; Chen, Ping

    2007-02-01

    Planar cell polarity (PCP) refers to the polarization of a field of cells within the plane of a cell sheet. This form of polarization is required for diverse cellular processes in vertebrates, including convergent extension (CE), the establishment of PCP in epithelial tissues and ciliogenesis. Perhaps the most distinct example of vertebrate PCP is the uniform orientation of stereociliary bundles at the apices of sensory hair cells in the mammalian auditory sensory organ. The establishment of PCP in the mammalian cochlea occurs concurrently with CE in this ciliated epithelium, therefore linking three cellular processes regulated by the vertebrate PCP pathway in the same tissue and emerging as a model system for dissecting PCP signaling. This review summarizes the morphogenesis of this model system to assist the interpretation of the emerging data and proposes molecular mechanisms underlying PCP signaling in vertebrates.

  6. Data compilations for primary production, herbivory, decomposition, and export for different types of marine communities, 1962-2002 (NCEI Accession 0054500)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset is a compilation of published data on primary production, herbivory, and nutrient content of primary producers in pristine communities of...

  7. When Forest become carbon sources: Impact of herbivory on carbon balance

    Science.gov (United States)

    Schafer, K. V.; Clark, K. L.; Skowronski, N. S.

    2008-12-01

    Traditionally forests are thought to be carbon sinks and are becoming important trading commodities in the carbon trading markets. However, disturbances such as fire, hurricanes and herbivory can lead to forests being sources rather than sinks of carbon. Here, we investigate the carbon balance of an oak/pine forest in the New Jersey Pine Barrens under herbivory attack in summer 2007. Net primary productivity (NPP) was reduced to ca 70% of previous year NPP (535 g m-2 a-1 in 2006) and canopy net assimilation (AnC), as modeled with the Canopy Conductance Constrained Carbon Assimilation model (4C-A), was reduced to ca 65 % of previous year (1335 g m-2 a-1 in 2006) AnC or ca 1015 g C m-2 a-1. Although the trees were defoliated for only 15 % of the normal annual growing season, the impact amounted to ca 30 % of C accumulation loss when integrated over the year. Overall NPP in 2007 was ca 378 g C m-2 a-1 with 50 % of NPP being allocated to foliage production which constitutes a short term carbon pool. On an ecosystem level net ecosystem exchange amounted to a release of 293 g C m-2 a-1 thus becoming a carbon source over the course of the year rather than being a sink for C. The overall impact of the defoliation spanned 21% of upland forests (320 km2) in the New Jersey Pine Barrens thus representing a significant amount of overall C being emitted back to the atmosphere rather than being accumulated in the biosphere.

  8. Low Herbivory among Targeted Reforestation Sites in the Andean Highlands of Southern Ecuador.

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    Marc-Oliver Adams

    Full Text Available Insect herbivory constitutes an important constraint in the viability and management of targeted reforestation sites. Focusing on young experimental stands at about 2000 m elevation in southern Ecuador, we examined foliar damage over one season as a function of tree species and habitat. Native tree species (Successional hardwood: Cedrela montana and Tabebuia chrysantha; fast-growing pioneer: Heliocarpus americanus have been planted among prevailing local landcover types (abandoned pasture, secondary shrub vegetation, and a Pinus patula plantation in 2003/4. Plantation trees were compared to conspecifics in the spontaneous undergrowth of adjacent undisturbed rainforest matched for height and foliar volume. Specifically, we tested the hypotheses that H. americanus as a pioneer species suffers more herbivory compared to the two successional tree species, and that damage is inversely related to habitat complexity. Overall leaf damage caused by folivorous insects (excluding leafcutter ants was low. Average leaf loss was highest among T. chrysantha (7.50% ± 0.19 SE of leaf area, followed by H. americanus (4.67% ± 0.18 SE and C. montana (3.18% ± 0.15 SE. Contrary to expectations, leaf area loss was highest among trees in closed-canopy natural rainforest, followed by pine plantation, pasture, and secondary shrub sites. Harvesting activity of leafcutter ants (Acromyrmex sp. was strongly biased towards T. chrysantha growing in open habitat (mean pasture: 2.5%; shrub: 10.5% where it could result in considerable damage (> 90.0%. Insect folivory is unlikely to pose a barrier for reforestation in the tropical Andean mountain forest zone at present, but leafcutter ants may become problematic if local temperatures increase in the wake of global warming.

  9. Low Herbivory among Targeted Reforestation Sites in the Andean Highlands of Southern Ecuador.

    Science.gov (United States)

    Adams, Marc-Oliver; Fiedler, Konrad

    2016-01-01

    Insect herbivory constitutes an important constraint in the viability and management of targeted reforestation sites. Focusing on young experimental stands at about 2000 m elevation in southern Ecuador, we examined foliar damage over one season as a function of tree species and habitat. Native tree species (Successional hardwood: Cedrela montana and Tabebuia chrysantha; fast-growing pioneer: Heliocarpus americanus) have been planted among prevailing local landcover types (abandoned pasture, secondary shrub vegetation, and a Pinus patula plantation) in 2003/4. Plantation trees were compared to conspecifics in the spontaneous undergrowth of adjacent undisturbed rainforest matched for height and foliar volume. Specifically, we tested the hypotheses that H. americanus as a pioneer species suffers more herbivory compared to the two successional tree species, and that damage is inversely related to habitat complexity. Overall leaf damage caused by folivorous insects (excluding leafcutter ants) was low. Average leaf loss was highest among T. chrysantha (7.50% ± 0.19 SE of leaf area), followed by H. americanus (4.67% ± 0.18 SE) and C. montana (3.18% ± 0.15 SE). Contrary to expectations, leaf area loss was highest among trees in closed-canopy natural rainforest, followed by pine plantation, pasture, and secondary shrub sites. Harvesting activity of leafcutter ants (Acromyrmex sp.) was strongly biased towards T. chrysantha growing in open habitat (mean pasture: 2.5%; shrub: 10.5%) where it could result in considerable damage (> 90.0%). Insect folivory is unlikely to pose a barrier for reforestation in the tropical Andean mountain forest zone at present, but leafcutter ants may become problematic if local temperatures increase in the wake of global warming.

  10. Assessing the Impacts of Herbivory on Plant Silica Accumulation across a Global Network of Grasslands

    Science.gov (United States)

    Quigley, K.

    2015-12-01

    Plants, especially grasses, have a profound impact on the biogeochemical cycling of silicon. Silicic acid (Si(OH)4) in soil water is absorbed by plant roots, transported via the transpiration stream, and deposited as solid silica (SiO2) phytoliths in leaf tissue. Evidence indicates that plant phytolith accumulation may have evolved as an anti-herbivore strategy, and modern studies reveal that these silica particles are abrasive to animal mouthparts and can interfere with digestion. Furthermore, several studies have shown that grasses have the ability to respond to insect and mammal herbivory by modifying the amount of silicon they absorb from soil, a property known as inducible defense. However, herbivory studies remain largely limited to a laboratory setting, and research in natural systems has only been conducted at a regional spatial scale. To address whether these localized patterns persist at the global scale, we utilized data from a network of 40 grassland sites occurring on six continents. Vegetation samples including grasses, forbs, and litter, were collected in and out of 6m x 6m herbivore exclosures by a team of collaborating scientists for an on-going research effort known as the Nutrient Network (NutNet). We utilized near infrared spectroscopy (NIRS) to create a calibration for plant silica which allowed for the rapid analysis of more than 1000 samples. Preliminary analyses indicate that silica content of grasses was higher outside of exclosures, where herbivores had access to vegetation. Our data reveal that herbivores play a significant role in modifying plant silicon uptake, and hence, the rates of silicon cycling in grasslands across the globe.

  11. Comparison of perimeter trap crop varieties: effects on herbivory, pollination, and yield in butternut squash.

    Science.gov (United States)

    Adler, L S; Hazzard, R V

    2009-02-01

    Perimeter trap cropping (PTC) is a method of integrated pest management (IPM) in which the main crop is surrounded with a perimeter trap crop that is more attractive to pests. Blue Hubbard (Cucurbita maxima Duch.) is a highly effective trap crop for butternut squash (C. moschata Duch. ex Poir) attacked by striped cucumber beetles (Acalymma vittatum Fabricius), but its limited marketability may reduce adoption of PTC by growers. Research comparing border crop varieties is necessary to provide options for growers. Furthermore, pollinators are critical for cucurbit yield, and the effect of PTC on pollination to main crops is unknown. We examined the effect of five border treatments on herbivory, pollination, and yield in butternut squash and manipulated herbivory and pollination to compare their importance for main crop yield. Blue Hubbard, buttercup squash (C. maxima Duch.), and zucchini (C. pepo L.) were equally attractive to cucumber beetles. Border treatments did not affect butternut leaf damage, but butternut flowers had the fewest beetles when surrounded by Blue Hubbard or buttercup squash. Yield was highest in the Blue Hubbard and buttercup treatments, but this effect was not statistically significant. Native bees accounted for 87% of pollinator visits, and pollination did not limit yield. There was no evidence that border crops competed with the main crop for pollinators. Our results suggest that both buttercup squash and zucchini may be viable alternatives to Blue Hubbard as borders for the main crop of butternut squash. Thus, growers may have multiple border options that reduce pesticide use, effectively manage pests, and do not disturb mutualist interactions with pollinators.

  12. Nanotechnology for treating osteoporotic vertebral fractures

    Directory of Open Access Journals (Sweden)

    Gao C

    2015-08-01

    Full Text Available Chunxia Gao,1,* Donglei Wei,1,* Huilin Yang,1 Tao Chen,2 Lei Yang1,3 1Department of Orthopaedic Surgery and Orthopaedic Institute, First Affiliated Hospital, 2Robotics and Microsystems Center, Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University, Suzhou, 3Laboratory of Nonlinear Mechanics, Institute of Mechanics, Chinese Academy of Sciences, Beijing, People’s Republic of China *These authors contributed equally to this work Abstract: Osteoporosis is a serious public health problem affecting hundreds of millions of aged people worldwide, with severe consequences including vertebral fractures that are associated with significant morbidity and mortality. To augment or treat osteoporotic vertebral fractures, a number of surgical approaches including minimally invasive vertebroplasty and kyphoplasty have been developed. However, these approaches face problems and difficulties with efficacy and long-term stability. Recent advances and progress in nanotechnology are opening up new opportunities to improve the surgical procedures for treating osteoporotic vertebral fractures. This article reviews the improvements enabled by new nanomaterials and focuses on new injectable biomaterials like bone cements and surgical instruments for treating vertebral fractures. This article also provides an introduction to osteoporotic vertebral fractures and current clinical treatments, along with the rationale and efficacy of utilizing nanomaterials to modify and improve biomaterials or instruments. In addition, perspectives on future trends with injectable bone cements and surgical instruments enhanced by nanotechnology are provided. Keywords: nanomaterials, osteoporosis, vertebral fracture, kyphoplasty, bone cement, pedicle screw, radiopacifier

  13. Vertebral morphometry: current methods and recent advances

    Energy Technology Data Exchange (ETDEWEB)

    Guglielmi, G. [University of Foggia, Department of Radiology, Foggia (Italy); Scientific Institute Hospital, Department of Radiology, San Giovanni Rotondo (Italy); Diacinti, D. [University La Sapienza, Department of Radiology, Roma (Italy); Kuijk, C. van [University of Amsterdam, Department of Radiology, Amsterdam (Netherlands); Aparisi, F. [Hospital Dr Peset, Department of Diagnostic Radiology, Valencia (Spain); Krestan, C. [Medical University of Vienna, Department of Radiology, Vienna (Austria); Adams, J.E. [University, Imaging Science and Biomedical Engineering, Manchester (United Kingdom); Link, T.M. [University of California, Department of Radiology, San Francisco, CA (United States)

    2008-07-15

    Vertebral fractures are the hallmark of osteoporosis and are associated with increased morbility and mortality. Because a majority of vertebral fractures often occur in absence of specific trauma and are asymptomatic, their identification is radiographic. The two most widely used methods to determine the severity of vertebral fractures are the visual semiquantitative (SQ) assessment and the morphometric quantitative approach, involving the measurements of vertebral body heights. The measurements may be made on conventional spinal radiographs (MRX: morphometric X-ray radiography) or on images obtained from dual X-ray absorptiometry (DXA) scans (MXA: morphometric X-ray absorptiometry).The availability of a rapid, low-dose method for assessment of vertebral fractures, using advanced fan-beam DXA devices, provides a practical method for integrated assessment of BMD and vertebral fracture status. The visual or morphometric assessment of lateral DXA spine images may have a potential role for use as a prescreening tool, excluding normal subjects prior to performing conventional radiographs. (orig.)

  14. The devil to pay: a cost of mutualism with Myrmelachista schumanni ants in 'devil's gardens' is increased herbivory on Duroia hirsuta trees.

    Science.gov (United States)

    Frederickson, Megan E; Gordon, Deborah M

    2007-04-22

    'Devil's gardens' are nearly pure stands of the myrmecophyte, Duroia hirsuta, that occur in Amazonian rainforests. Devil's gardens are created by Myrmelachista schumanni ants, which nest in D. hirsuta trees and kill other plants using formic acid as an herbicide. Here, we show that this ant-plant mutualism has an associated cost; by making devil's gardens, M. schumanni increases herbivory on D. hirsuta. We measured standing leaf herbivory on D. hirsuta trees and found that they sustain higher herbivory inside than outside devil's gardens. We also measured the rate of herbivory on nursery-grown D. hirsuta saplings planted inside and outside devil's gardens in ant-exclusion and control treatments. We found that when we excluded ants, herbivory on D. hirsuta was higher inside than outside devil's gardens. These results suggest that devil's gardens are a concentrated resource for herbivores. Myrmelachista schumanni workers defend D. hirsuta against herbivores, but do not fully counterbalance the high herbivore pressure in devil's gardens. We suggest that high herbivory may limit the spread of devil's gardens, possibly explaining why devil's gardens do not overrun Amazonian rainforests.

  15. Evolution of circadian organization in vertebrates

    Directory of Open Access Journals (Sweden)

    M. Menaker

    1997-03-01

    Full Text Available Circadian organization means the way in which the entire circadian system above the cellular level is put together physically and the principles and rules that determine the interactions among its component parts which produce overt rhythms of physiology and behavior. Understanding this organization and its evolution is of practical importance as well as of basic interest. The first major problem that we face is the difficulty of making sense of the apparently great diversity that we observe in circadian organization of diverse vertebrates. Some of this diversity falls neatly into place along phylogenetic lines leading to firm generalizations: i in all vertebrates there is a "circadian axis" consisting of the retinas, the pineal gland and the suprachiasmatic nucleus (SCN, ii in many non-mammalian vertebrates of all classes (but not in any mammals the pineal gland is both a photoreceptor and a circadian oscillator, and iii in all non-mammalian vertebrates (but not in any mammals there are extraretinal (and extrapineal circadian photoreceptors. An interesting explanation of some of these facts, especially the differences between mammals and other vertebrates, can be constructed on the assumption that early in their evolution mammals passed through a "nocturnal bottleneck". On the other hand, a good deal of the diversity among the circadian systems of vertebrates does not fall neatly into place along phylogenetic lines. In the present review we will consider how we might better understand such "phylogenetically incoherent" diversity and what sorts of new information may help to further our understanding of the evolution of circadian organization in vertebrates

  16. Jack vertebral dilator kyphoplasty for treatment of osteoporotic vertebral compression fractures.

    Science.gov (United States)

    Li, Dapeng; Huang, Yonghui; Yang, Huilin; Chen, Qi; Sun, Taicun; Wu, Yan; Li, Xuefeng

    2014-01-01

    Osteoporotic vertebral compression fractures (OVCFs) are common in the elderly population and often involve the thoracolumbar vertebrae. Clinical symptoms of OVCFs include severe pain, loss of vertebral height, progressive kyphosis and increased mortality. Jack vertebral dilator kyphoplasty is a recently developed OVCFs treatment modality, with few systematic studies present in the literature. This retrospective study was designed to investigate the safety and efficacy of Jack vertebral dilator kyphoplasty for treating thoracolumbar OVCFs. Sixteen elderly patients (55-85 years) with solitary thoracolumbar OVCFs were treated with this procedure and followed-up (10-27 months). The amount of injected bone cement and operative time, preoperative and postoperative visual analogue scores, anterior and middle vertebral body heights, local kyphosis angle, and complications was analysed. The results showed that the method provided long-term pain relief and restoration of the vertebral body height and spinal alignment. No serious complications occurred, but two patients experienced recompression of the vertebral body, and one patient experienced cement leakage into a disc. In conclusion, Jack vertebral dilator kyphoplasty is a safe and effective minimally invasive procedure for treatment of OVCFs.

  17. Efficacy of plastic mesh tubes in reducing herbivory damage by the invasive nutria (Myocastor coypus) in an urban restoration site

    Science.gov (United States)

    Sheffels, Trevor R.; Systma, Mark D.; Carter, Jacoby; Taylor, Jimmy D.

    2014-01-01

    The restoration of stream corridors is becoming an increasingly important component of urban landscape planning, and the high cost of these projects necessitates the need to understand and address potential ecological obstacles to project success. The nutria(Myocastor coypus) is an invasive, semi-aquatic rodent native to South America that causes detrimental ecological impacts in riparian and wetland habitats throughout its introduced range, and techniques are needed to reduce nutria herbivory damage to urban stream restoration projects. We assessed the efficacy of standard Vexar® plastic mesh tubes in reducing nutria herbivory damage to newly established woody plants. The study was conducted in winter-spring 2009 at Delta Ponds, a 60-ha urban waterway in Eugene, Oregon. Woody plants protected by Vexar® tubes demonstrated 100% survival over the 3-month initial establishment period, while only 17% of unprotected plantings survived. Nutria demonstrated a preference for black cottonwood (Populus balsamifera ssp trichocarpa) over red osier dogwood (Cornussericea) and willow (Salix spp). Camera surveillance showed that nutria were more active in unprotected rather than protected treatments. Our results suggest that Vexar® plastic mesh tubing can be an effective short-term herbivory mitigation tool when habitat use by nutria is low. Additionally, planting functionally equivalent woody plant species that are less preferred by nutria, and other herbivores, may be another method for reducing herbivory and improving revegetation success. This study highlights the need to address potential wildlife damage conflicts in the planning process for stream restoration in urban landscapes.

  18. High tolerance to salinity and herbivory stresses may explain the expansion of Ipomoea cairica to salt marshes.

    Directory of Open Access Journals (Sweden)

    Gang Liu

    Full Text Available BACKGROUND: Invasive plants are often confronted with heterogeneous environments and various stress factors during their secondary phase of invasion into more stressful habitats. A high tolerance to stress factors may allow exotics to successfully invade stressful environments. Ipomoea cairica, a vigorous invader in South China, has recently been expanding into salt marshes. METHODOLOGY/PRINCIPAL FINDINGS: To examine why this liana species is able to invade a stressful saline environment, we utilized I. cairica and 3 non-invasive species for a greenhouse experiment. The plants were subjected to three levels of salinity (i.e., watered with 0, 4 and 8 g L(-1 NaCl solutions and simulated herbivory (0, 25 and 50% of the leaf area excised treatments. The relative growth rate (RGR of I. cairica was significantly higher than the RGR of non-invasive species under both stress treatments. The growth performance of I. cairica was not significantly affected by either stress factor, while that of the non-invasive species was significantly inhibited. The leaf condensed tannin content was generally lower in I. cairica than in the non-invasive I. triloba and Paederia foetida. Ipomoea cairica exhibited a relatively low resistance to herbivory, however, its tolerance to stress factors was significantly higher than either of the non-invasive species. CONCLUSIONS/SIGNIFICANCE: This is the first study examining the expansion of I. cairica to salt marshes in its introduced range. Our results suggest that the high tolerance of I. cairica to key stress factors (e.g., salinity and herbivory contributes to its invasion into salt marshes. For I. cairica, a trade-off in resource reallocation may allow increased resources to be allocated to tolerance and growth. This may contribute to a secondary invasion into stressful habitats. Finally, we suggest that I. cairica could spread further and successfully occupy salt marshes, and countermeasures based on herbivory could be

  19. Evolution of innate and adaptive immune systems in jawless vertebrates.

    Science.gov (United States)

    Kasamatsu, Jun

    2013-01-01

    Because jawless vertebrates are the most primitive vertebrates, they have been studied to gain understanding of the evolutionary processes that gave rise to the innate and adaptive immune systems in vertebrates. Jawless vertebrates have developed lymphocyte-like cells that morphologically resemble the T and B cells of jawed vertebrates, but they express variable lymphocyte receptors (VLRs) instead of the T and B cell receptors that specifically recognize antigens in jawed vertebrates. These VLRs act as antigen receptors, diversity being generated in their antigen-binding sites by assembly of highly diverse leucine-rich repeat modules. Therefore, jawless vertebrates have developed adaptive immune systems based on the VLRs. Although pattern recognition receptors, including Toll-like receptors (TLRs) and Rig-like receptors (RLRs), and their adaptor genes are conserved in jawless vertebrates, some transcription factor and inflammatory cytokine genes in the TLR and RLR pathways are not present. However, like jawed vertebrates, the initiation of adaptive immune responses in jawless vertebrates appears to require prior activation of the innate immune system. These observations imply that the innate immune systems of jawless vertebrates have a unique molecular basis that is distinct from that of jawed vertebrates. Altogether, although the molecular details of the innate and adaptive immune systems differ between jawless and jawed vertebrates, jawless vertebrates have developed versions of these immune systems that are similar to those of jawed vertebrates.

  20. Post-traumatic Vertebral Compression Fracture Treated with Minimally Invasive Biologic Vertebral Augmentation for Reconstruction.

    Science.gov (United States)

    Chiu, John C; Maziad, Ali M

    2011-12-01

    In the United States, there is a high incidence of motor vehicle and sports injuries among the active population causing symptomatic post-traumatic vertebral compression fracture. At our institution, 28 cases of painful post-traumatic vertebral compression fractures (PPT-VCFs) were successfully treated with percutaneous vertebral augmentation (VA) for stabilization and reconstruction with intravertebral polyethylene mesh sac (OptiMesh®, Spineology, Inc., Stillwater, MN) and biological morcelized bone graft. The surgical approach provides an efficacious and controlled minimally invasive delivery mechanism to stabilize and reconstruct VCFs, as well as avoiding serious complications from Polymethylmethacrylate (PMMA) of vertebroplasty and kyphoplasty. The construct for biological bone graft/vertebral augmentation is osteoconductive and osteoinductive, and is used to create biologic vertebral stabilization and reconstruction. The adjacent vertebra integrity is protected by the construct with similar elasticity and physical characteristics of the biologic morcelized bone, more matched to that of adjacent bone than PMMA. The surgical techniques are described herein.

  1. Vertebrate extracellular preovulatory and postovulatory egg coats.

    Science.gov (United States)

    Menkhorst, Ellen; Selwood, Lynne

    2008-11-01

    Extracellular egg coats deposited by maternal or embryonic tissues surround all vertebrate conceptuses during early development. In oviparous species, the time of hatching from extracellular coats can be considered equivalent to the time of birth in viviparous species. Extracellular coats must be lost during gestation for implantation and placentation to occur in some viviparous species. In the most recent classification of vertebrate extracellular coats, Boyd and Hamilton (Cleavage, early development and implantation of the egg. In: Parkes AS (ed.), Marshall's Physiology of Reproduction, vol. 2, 3rd ed. London: Longmans, Green & Co; 1961:1-126) defined the coat synthesized by the oocyte during oogenesis as primary and the coat deposited by follicle cells surrounding the oocyte as secondary. Tertiary egg coats are those synthesized and deposited around the primary or secondary coat by the maternal reproductive tract. This classification is difficult to reconcile with recent data collected using modern molecular biological techniques that can accurately establish the site of coat precursor synthesis and secretion. We propose that a modification to the classification by Boyd and Hamilton is required. Vertebrate egg coats should be classed as belonging to the following two broad groups: the preovulatory coat, which is deposited during oogenesis by the oocyte or follicle cells, and the postovulatory coats, which are deposited after fertilization by the reproductive tract or conceptus. This review discusses the origin and classification of vertebrate extracellular preovulatory and postovulatory coats and illustrates what is known about coat homology between the vertebrate groups.

  2. Herbivory and arbuscular mycorrhiza in natural populations of Datura stramonium L.: correlation with the availability of nutrients in the soil

    Directory of Open Access Journals (Sweden)

    Ana Aguilar-Chama

    2016-03-01

    Full Text Available Trophic interactions impose important costs to their host plants, affecting patterns of resource allocation. The relationship between host and consumers is also influenced by the availability of resources, e. g., soil nutrients. In this study, we explored the relationship among mycorrhiza-plant-herbivore in natural populations of Datura stramonium and their correlation with the content of phosphorus, nitrogen and carbon in the soil. We estimated the vegetative and reproductive biomass of plants, the arbuscular mycorrhizal colonization and the level of herbivory in populations of D. stramonium. The local abundance of D. stramonium was negatively related to the content of phosphorus in the soil. In contrast, soil carbon concentration affected positively the vegetative and reproductive mass of D. stramonium, although it was negatively correlated with the specific leaf area (SLA. Of the trophic interactions only herbivory was significantly correlated with the SLA and no relationship was detected between the two interaction types. The lack of significant response of mycorrhizae to the soil nutrients concentration, plant performance, and herbivory may result from the stochasticity in the availability of mycorrhizal inoculum (identity and abundance in the populations studied.

  3. Losses of leaf area owing to herbivory and early senescence in three tree species along a winter temperature gradient

    Science.gov (United States)

    González-Zurdo, P.; Escudero, A.; Nuñez, R.; Mediavilla, S.

    2016-11-01

    In temperate climates, evergreen leaves have to survive throughout low temperature winter periods. Freezing and chilling injuries can lead to accelerated senescence of part of the leaf surface, which contributes to a reduction of the lifespan of the photosynthetic machinery and of leaf lifetime carbon gain. Low temperatures are also associated with changes in foliar chemistry and morphology that affect consumption by herbivores. Therefore, the severity of foliar area losses caused by accelerated senescence and herbivory can change along winter temperature gradients. The aim of this study is to analyse such responses in the leaves of three evergreen species ( Quercus ilex, Q. suber and Pinus pinaster) along a climatic gradient. The leaves of all three species presented increased leaf mass per area (LMA) and higher concentrations of structural carbohydrates in cooler areas. Only the two oak species showed visible symptoms of damage caused by herbivory, this being less intense at the coldest sites. The leaves of all three species presented chlorotic and necrotic spots that increased in size with leaf age. The foliar surface affected by chlorosis and necrosis was larger at the sites with the coldest winters. Therefore, the effects of the winter cold on the lifespan of the photosynthetic machinery were contradictory: losses of leaf area due to accelerated senescence increased, but there was a decrease in losses caused by herbivory. The final consequences for carbon assimilation strongly depend on the exact timing of the appearance of the damage resulting from low temperature and grazing by herbivores.

  4. The Effect of Bark Borer Herbivory on BVOC Emissions in Boreal Forests and Implications for SOA Formation

    Science.gov (United States)

    Faiola, Celia; Joutsensaari, Jorma; Holopainen, Jarmo; Yli-Juuti, Taina; Kokkola, Harri; Blande, James; Guenther, Alex; Virtanen, Annele

    2015-04-01

    Herbivore outbreaks are expected to increase as a result of climate change. These outbreaks can have significant effects on the emissions of biogenic volatile organic compound (BVOC) from vegetation, which contribute to the formation of secondary organic aerosol (SOA). We have synthesized the published results investigating changes to BVOC emissions from herbivory by the pine weevil, Hylobius abietis--a bark borer herbivore. Previous lab experiments have shown that bark borer herbivory on Scots pine trees increases monoterpene emissions 4-fold and sesquiterpene emissions 7-fold. Norway spruce exhibits a similar response. The BVOCs most impacted were linalool, beta-phellandrene, limonene, alpha-pinene, beta-pinene, myrcene, and sesquiterpenes like beta-farnesene, beta-bourbonene, and longifolene. The quantitative results from these studies were used to estimate potential impacts of bark borer herbivory on BVOC emissions at a regional scale using the Model of Emissions of Gases and Aerosols from Nature (MEGAN). MEGAN was run under baseline and herbivore outbreak conditions for a typical boreal forest environment in spring. Emissions output from MEGAN was used to run a microphysical box model to estimate the SOA formation potential under baseline and outbreak conditions. This estimate could provide us with an upper limit to the potential impact of bark borer outbreaks on SOA formation in a boreal forest.

  5. Effects of Canada goose herbivory on the tidal freshwater wetlands in Anacostia Park, 2009-2011

    Science.gov (United States)

    Krafft, Cairn C.; Hatfield, Jeffrey S.; Hammerschlag, Richard S.

    2013-01-01

    Herbivory has played a major role in dictating vegetation abundance and species composition at Kingman Marsh in Anacostia Park, Washington, D.C., since restoration of this tidal freshwater wetland was initiated in 2000. The diverse and robust vegetative cover that developed in the first year post-reconstruction experienced significant decimation in the second year, after the protective fencing was removed, and remained suppressed throughout the five-year study period. In June 2009 a herbivory study was initiated to document the impacts of herbivory by resident and nonmigratory Canada geese (Branta canadensis) to vegetation at Kingman Marsh. Sixteen modules consisting of paired fenced plots and unfenced control plots were constructed. Eight of the modules were installed in vegetated portions of the restoration site that had been protected over time by pre-existing fencing, while the remaining eight modules were placed in portions of the site that had not been protected over time and were basically unvegetated at the start of the experiment. Exclosure fencing was sufficiently elevated from the substrate level to allow access to other herbivores such as fish and turtles, while hopefully excluding mature Canada geese. The study was designed with an initial exclosure elevation of 20 cm. This elevation was chosen based on the literature, as adequate to exclude mature Canada geese, while maximizing access to other herbivores such as fish and turtles. Repeated measures analysis of variance (ANOVA) was used to analyze the differences between paired fenced and unfenced control plots for a number of variables including total vegetative cover. Differences in total vegetative cover were not statistically significant for the baseline data collected in June 2009. By contrast, two months after the old protective fencing was removed from the initially-vegetated areas to allow Canada geese access to the unfenced control plots, total vegetative cover had declined dramatically in the

  6. Mitochondrial genome organization and vertebrate phylogenetics

    Directory of Open Access Journals (Sweden)

    Pereira Sérgio Luiz

    2000-01-01

    Full Text Available With the advent of DNA sequencing techniques the organization of the vertebrate mitochondrial genome shows variation between higher taxonomic levels. The most conserved gene order is found in placental mammals, turtles, fishes, some lizards and Xenopus. Birds, other species of lizards, crocodilians, marsupial mammals, snakes, tuatara, lamprey, and some other amphibians and one species of fish have gene orders that are less conserved. The most probable mechanism for new gene rearrangements seems to be tandem duplication and multiple deletion events, always associated with tRNA sequences. Some new rearrangements seem to be typical of monophyletic groups and the use of data from these groups may be useful for answering phylogenetic questions involving vertebrate higher taxonomic levels. Other features such as the secondary structure of tRNA, and the start and stop codons of protein-coding genes may also be useful in comparisons of vertebrate mitochondrial genomes.

  7. The efficacy of radiotherapy for vertebral hemangiomas.

    Science.gov (United States)

    Miszczyk, L; Ficek, K; Trela, K; Spindel, J

    2001-01-01

    Vertebral hemangiomas are benign, slowly growing tumors sometimes causing local pain in the spine and/or neurologic disorders. The present paper includes 14 cases of painful vertebral hemangiomas treated by radiotherapy. All patients were irradiated using standard fractionation scheme with a total dose 20-30 Gy. One month after the treatment complete pain relief was noted in 36% of cases, five months later in 67% of cases, but in the remaining cases partial pain relief was noted. No correlation between treatment outcome and different biological and technical factors was found. No dose-response relationship was noted. The results suggest that anti-inflamatory effect of radiation plays the major role in this kind of treatment and that radiotherapy for vertebral hemangiomas is easy, short and highly effective analgetic treatment modality.

  8. The vertebral column of Australopithecus sediba.

    Science.gov (United States)

    Williams, Scott A; Ostrofsky, Kelly R; Frater, Nakita; Churchill, Steven E; Schmid, Peter; Berger, Lee R

    2013-04-12

    Two partial vertebral columns of Australopithecus sediba grant insight into aspects of early hominin spinal mobility, lumbar curvature, vertebral formula, and transitional vertebra position. Au. sediba likely possessed five non-rib-bearing lumbar vertebrae and five sacral elements, the same configuration that occurs modally in modern humans. This finding contrasts with other interpretations of early hominin regional vertebral numbers. Importantly, the transitional vertebra is distinct from and above the last rib-bearing vertebra in Au. sediba, resulting in a functionally longer lower back. This configuration, along with a strongly wedged last lumbar vertebra and other indicators of lordotic posture, would have contributed to a highly flexible spine that is derived compared with earlier members of the genus Australopithecus and similar to that of the Nariokotome Homo erectus skeleton.

  9. Chitin is endogenously produced in vertebrates.

    Science.gov (United States)

    Tang, W Joyce; Fernandez, Javier G; Sohn, Joel J; Amemiya, Chris T

    2015-03-30

    Chitin, a biopolymer of N-acetylglucosamine, is abundant in invertebrates and fungi and is an important structural molecule [1, 2]. There has been a longstanding belief that vertebrates do not produce chitin; however, we have obtained compelling evidence to the contrary. Chitin synthase genes are present in numerous fishes and amphibians, and chitin is localized in situ to the lumen of the developing zebrafish gut, in epithelial cells of fish scales, and in at least three different cell types in larval salamander appendages. Chitin synthase gene knockdowns and various histochemical experiments in zebrafish further authenticated our results. Finally, a polysaccharide was extracted from scales of salmon that exhibited all the chemical hallmarks of chitin. Our data and analyses demonstrate the existence of endogenous chitin in vertebrates and suggest that it serves multiple roles in vertebrate biology.

  10. The origin of the vertebrate skeleton

    Science.gov (United States)

    Pivar, Stuart

    2011-01-01

    The anatomy of the human and other vertebrates has been well described since the days of Leonardo da Vinci and Vesalius. The causative origin of the configuration of the bones and of their shapes and forms has been addressed over the ensuing centuries by such outstanding investigators as Goethe, Von Baer, Gegenbauer, Wilhelm His and D'Arcy Thompson, who sought to apply mechanical principles to morphogenesis. However, no coherent causative model of morphogenesis has ever been presented. This paper presents a causative model for the origin of the vertebrate skeleton, based on the premise that the body is a mosaic enlargement of self-organized patterns engrained in the membrane of the egg cell. Drawings illustrate the proposed hypothetical origin of membrane patterning and the changes in the hydrostatic equilibrium of the cytoplasm that cause topographical deformations resulting in the vertebrate body form.

  11. Climate, herbivory, and fire controls on tropical African forest for the last 60ka

    Science.gov (United States)

    Ivory, Sarah J.; Russell, James

    2016-09-01

    The Last Glacial Maximum (LGM) in Africa was drier than today and was followed by rapid step-wise climate changes during the last deglacial period. In much of Africa, these changes led to a drastic reduction of lowland forest area during the LGM, followed by recolonization of the lowlands by forest and woodland in concert with regional warming and wetting. However, the history of southeastern African vegetation contrasts with that observed further north. In particular, forest expansion appears to have occurred in southeastern Africa during episodes of high-latitude northern hemisphere cooling. Although vegetation history in Africa is generally assumed to relate purely to climate, previous studies have not addressed potential feedbacks between climate, vegetation, and disturbance regimes (fire, herbivory) that may create tipping points in ecosystems. This climate-vegetation history has profound implications for our understanding of the modern architecture of lowland and highland forests, both thought to be at risk from future climate change. Here we present analyses of fossil pollen, charcoal, and Sporormiella (dung fungus) on a continuous 60 kyr record from central Lake Tanganyika, Southeast Africa, that illustrates the interplay of climate and disturbance regimes in shaping vegetation composition and structure. We observe that extensive forests dominated the region during the last glacial period despite evidence of decreased rainfall. At the end of the LGM, forest opening at ∼17.5 ka followed warming temperatures but preceded rising precipitation, suggesting that temperature-induced water stress and disturbance from fire and herbivory affected initial landscape transformation. Our Sporormiella record indicates that mega-herbivore populations increased at the early Holocene. This higher animal density increased plant species richness and encouraged landscape heterogeneity until the mid-Holocene. At this time, regional drying followed by the onset of the Iron Age

  12. Above- and belowground responses of Arctic tundra ecosystems to altered soil nutrients and mammalian herbivory.

    Science.gov (United States)

    Gough, Laura; Moore, John C; Shaver, Gauis R; Simpson, Rodney T; Johnson, David R

    2012-07-01

    Theory and observation indicate that changes in the rate of primary production can alter the balance between the bottom-up influences of plants and resources and the top-down regulation of herbivores and predators on ecosystem structure and function. The exploitation ecosystem hypothesis (EEH) posited that as aboveground net primary productivity (ANPP) increases, the additional biomass should support higher trophic levels. We developed an extension of EEH to include the impacts of increases in ANPP on belowground consumers in a similar manner as aboveground, but indirectly through changes in the allocation of photosynthate to roots. We tested our predictions for plants aboveground and for phytophagous nematodes and their predators belowground in two common arctic tundra plant communities subjected to 11 years of increased soil nutrient availability and/or exclusion of mammalian herbivores. The less productive dry heath (DH) community met the predictions of EEH aboveground, with the greatest ANPP and plant biomass in the fertilized plots protected from herbivory. A palatable grass increased in fertilized plots while dwarf evergreen shrubs and lichens declined. Belowground, phytophagous nematodes also responded as predicted, achieving greater biomass in the higher ANPP plots, whereas predator biomass tended to be lower in those same plots (although not significantly). In the higher productivity moist acidic tussock (MAT) community, aboveground responses were quite different. Herbivores stimulated ANPP and biomass in both ambient and enriched soil nutrient plots; maximum ANPP occurred in fertilized plots exposed to herbivory. Fertilized plots became dominated by dwarf birch (a deciduous shrub) and cloudberry (a perennial forb); under ambient conditions these two species coexist with sedges, evergreen dwarf shrubs, and Sphagnum mosses. Phytophagous nematodes did not respond significantly to changes in ANPP, although predator biomass was greatest in control plots. The

  13. A paleontological perspective of vertebrate origin

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The Early Cambrian Haikouichthys and Haikouella have been claimed to be related to contribute in an important way to our understanding of vertebrate origin, but there have been heated debates about how exactly they are to be interpreted. New discoveries of numerous specimens of Haikouichthys not only confirm the identity of previously described structures such as the dorsal and the ventral fins, and chevron-shaped myomeres, but also reveal many new important characteristics, including sensory organs of the head (e.g. large eyes), and a prominent notochord with differentiated vertebral elements. This "first fish" appears, however, to retain primitive reproductive features of acraniates, suggesting that it is a stem-group craniates. A new order (Myllokunmingiida) and a new family (Myllokunmingiidae) are erected, and a new species, Zhongjianichthys rostratus (gen. et sp. nov.), is described herein. Over 1400 newly-discovered specimens of Haikouella provide a wealth of anatomical information on this organism. It differs from chordates in many organs and organ systems, including the skin, muscles, respiratory, circulatory and nervous systems. In contrast, its body-design resembles that of vetulicolians, and the presence of a "transitional" nervous system with both dorsal and ventral nerve cords suggests an affinity with living hemichordates. On the basis of these and other recent findings of fossil deuterostomes, a five-step hypothesis for vertebrate origin is proposed, intended to bridge the long- standing gap between protostomes and vertebrates. Four of the five steps accord with established ideas current in modern evolutionary zoology. Evidence for the first step is obtainable only from fossils, and specifically from fossils found from South China, hence the crucial importance of S. China sites for our understanding of early vertebrate origins and evolution. Accordingly, South China is suggested as the oldest-known birthplace of the whole vertebrates.

  14. Herbivory of wild Manduca sexta causes fast down-regulation of photosynthetic efficiency in Datura wrightii: an early signaling cascade visualized by chlorophyll fluorescence.

    Science.gov (United States)

    Barron-Gafford, Greg A; Rascher, Uwe; Bronstein, Judith L; Davidowitz, Goggy; Chaszar, Brian; Huxman, Travis E

    2012-09-01

    Plants experiencing herbivory suffer indirect costs beyond direct loss of leaf area, but differentially so based on the herbivore involved. We used a combination of chlorophyll fluorescence imaging and gas exchange techniques to quantify photosynthetic performance, the efficiency of photochemistry, and heat dissipation to examine immediate and longer-term physiological responses in the desert perennial Datura wrightii to herbivory by tobacco hornworm, Manduca sexta. Herbivory by colony-reared larvae yielded no significant reduction in carbon assimilation, whereas herbivory by wild larvae induced a fast and spreading down-regulation of photosynthetic efficiency, resulting in significant losses in carbon assimilation in eaten and uneaten leaves. We found both an 89 % reduction in net photosynthetic rates in herbivore-damaged leaves and a whole-plant response (79 % decrease in undamaged leaves from adjacent branches). Consequently, herbivory costs are higher than previously estimated in this well-studied plant-insect interaction. We used chlorophyll fluorescence imaging to elucidate the mechanisms of this down-regulation. Quantum yield decreased up to 70 % in a small concentric band surrounding the feeding area within minutes of the onset of herbivory. Non-photochemical energy dissipation by the plant to avoid permanent damage was elevated near the wound, and increased systematically in distant areas of the leaf away from the wound over subsequent hours. Together, the results underscore not only potential differences between colony-reared and wild-caught herbivores in experimental studies of herbivory but also the benefits of quantifying physiological responses of plants in unattacked leaves.

  15. Is there a missing link? Effects of root herbivory on plant-pollinator interactions and reproductive output in a monocarpic species.

    Science.gov (United States)

    Ghyselen, C; Bonte, D; Brys, R

    2016-01-01

    Herbivores can have a major influence on plant fitness. The direct impact of herbivory on plant reproductive output has long been studied, and recently also indirect effects of herbivory on plant traits and pollinator attraction have received increasing attention. However, the link between these direct and indirect effects has seldom been studied. In this study, we investigated effects of root herbivory on plant and floral traits, pollination success and reproductive outcome in the monocarpic perennial Cynoglossum officinale. We exposed 119 C. officinale plants to a range of root herbivore damage by its specialist herbivore Mogulones cruciger. We assessed the effect of herbivory on several plant traits, pollinator foraging behaviour and reproductive output, and to elucidate the link between these last two we also quantified pollen deposition and pollen tube growth and applied a pollination experiment to test whether seed set was pollen-limited. Larval root herbivory induced significant changes in plant traits and had a negative impact on pollinator visitation. Infested plants were reduced in size, had fewer flowers and received fewer pollinator visits at plant and flower level than non-infested plants. Also, seed set was negatively affected by root herbivory, but this could not be attributed to pollen limitation since neither stigmatic pollen loads and pollen tube growth nor the results of the hand-pollination experiment differed between infested and non-infested plants. Our observations demonstrate that although herbivory may induce significant changes in flowering behaviour and resulting plant-pollinator interactions, it does not necessarily translate into higher rates of pollen limitation. The observed reductions in reproductive output following infection can mainly be attributed to higher resource limitation compared to non-infested plants.

  16. Nontarget herbivory by a weed biocontrol insect is limited to spillover, reducing the chance of population-level impacts.

    Science.gov (United States)

    Catton, Haley A; Lalonde, Robert G; De Clerck-Floate, Rosemarie A

    2015-03-01

    Insects approved for classical biocontrol of weeds are often capable of using close relatives of their target weed for feeding, oviposition, or larval development, with reduced preference and performance. When nontarget herbivory occurs and is suspected to reduce survival, growth, or fecundity of individual plants, and insects are capable of reproducing on their nontarget host, characterization of spatial and temporal patterns of the occurrence and intensity of herbivory is valuable for predicting potential population-level effects. Here, we perform a novel post-release manipulative field experiment with a root-feeding biocontrol weevil, Mogulones crucifer, released in Canada to control the rangeland weed Cynoglossum officinale, to test for its ability to establish on the nontarget plant Hackelia micrantha. After Cynoglossum, M. crucifer exhibits its highest preference for and performance on Hackelia spp. We released M. crucifer on Canadian rangeland sites with naturally occurring populations of H. micrantha growing interspersed with the target weed or in the near absence of the target weed. Adult weevil feeding on surrounding plants was monitored for three summers after release (years 0, 1, and 2), and, subsequently, subsets of plants were destructively sampled to determine M. crucifer oviposition levels. Additional oviposition and larval development data were obtained from seven non-experimental sites where weevils were released zero, three, or four years earlier. M. crucifer was not detected on experimental sites without C. officinale after two years, and nontarget herbivory was restricted to rare, low-level spillover. Visible evidence of adult herbivory (i.e., scars on shoots) was associated with oviposition in 90% of targets but only 30% of nontarget plants. We infer, through ecological refuge theory, that nontarget population-level impacts from M. crucifer spillover are unlikely because of temporal, spatial, and probabilistic refuges from herbivory, and make

  17. Population-level consequences of herbivory, changing climate, and source-sink dynamics on a long-lived invasive shrub.

    Science.gov (United States)

    van Klinken, R D; Pichancourt, J B

    2015-12-01

    Long-lived plant species are highly valued environmentally, economically, and socially, but can also cause substantial harm as invaders. Realistic demographic predictions can guide management decisions, and are particularly valuable for long-lived species where population response times can be long. Long-lived species are also challenging, given population dynamics can be affected by factors as diverse as herbivory, climate, and dispersal. We developed a matrix model to evaluate the effects of herbivory by a leaf-feeding biological control agent released in Australia against a long-lived invasive shrub (mesquite, Leguminoseae: Prosopis spp.). The stage-structured, density-dependent model used an annual time step and 10 climatically diverse years of field data. Mesquite population demography is sensitive to source-sink dynamics as most seeds are consumed and redistributed spatially by livestock. In addition, individual mesquite plants, because they are long lived, experience natural climate variation that cycles over decadal scales, as well as anthropogenic climate change. The model therefore explicitly considered the effects of both net dispersal and climate variation. Herbivory strongly regulated mesquite populations through reduced growth and fertility, but additional mortality of older plants will be required to reach management goals within a reasonable time frame. Growth and survival of seeds and seedlings were correlated with daily soil moisture. As a result, population dynamics were sensitive to rainfall scenario, but population response times were typically slow (20-800 years to reach equilibrium or extinction) due to adult longevity. Equilibrium population densities were expected to remain 5% higher, and be more dynamic, if historical multi-decadal climate patterns persist, the effect being dampened by herbivory suppressing seed production irrespective of preceding rainfall. Dense infestations were unlikely to form under a drier climate, and required net

  18. Complex osteotomies vertebral column resection and decancellation.

    Science.gov (United States)

    Obeid, Ibrahim; Bourghli, Anouar; Boissière, Louis; Vital, Jean-Marc; Barrey, Cédric

    2014-07-01

    Pedicle subtraction osteotomy (PSO) is nowadays widely used to treat sagittal imbalance. Some complex malalignment cases cannot be treated by a PSO, whereas the imbalance is coronal or mixed or the sagittal imbalance is major and cannot be treated by a single PSO. The aim of this article was to review these complex situations--coronal imbalance, mixed imbalance, two-level PSO, vertebral column resection, and vertebral column decancellation, and to focus on their specificities. It wills also to evoke the utility of navigation in these complex cases.

  19. Slipped vertebral epiphysis (report of 2 cases

    Directory of Open Access Journals (Sweden)

    Majid Reza Farrokhi

    2009-02-01

    Full Text Available

    • Avulsion or fracture of posterior ring apophysis of lumbar vertebra is an uncommon cause of radicular low back pain in pediatric age group, adolescents and athletes. This lesion is one of differential diagnosis of disc herniation. We reported two teenage boys with sever low back pain and sciatica during soccer play that ultimately treated with diagnosis of lipped vertebral apophysis.
    • KEY WORDS: Ring Apophysis, vertebral fracture, sciatica, low back pain, disc herniation.

  20. Scenarios for the making of vertebrates.

    Science.gov (United States)

    Holland, Nicholas D; Holland, Linda Z; Holland, Peter W H

    2015-04-23

    Over the past 200 years, almost every invertebrate phylum has been proposed as a starting point for evolving vertebrates. Most of these scenarios are outdated, but several are still seriously considered. The short-range transition from ancestral invertebrate chordates (similar to amphioxus and tunicates) to vertebrates is well accepted. However, longer-range transitions leading up to the invertebrate chordates themselves are more controversial. Opinion is divided between the annelid and the enteropneust scenarios, predicting, respectively, a complex or a simple ancestor for bilaterian animals. Deciding between these ideas will be facilitated by further comparative studies of multicellular animals, including enigmatic taxa such as xenacoelomorphs.

  1. Zebrafish hox clusters and vertebrate genome evolution.

    Science.gov (United States)

    Amores, A; Force, A; Yan, Y L; Joly, L; Amemiya, C; Fritz, A; Ho, R K; Langeland, J; Prince, V; Wang, Y L; Westerfield, M; Ekker, M; Postlethwait, J H

    1998-11-27

    HOX genes specify cell fate in the anterior-posterior axis of animal embryos. Invertebrate chordates have one HOX cluster, but mammals have four, suggesting that cluster duplication facilitated the evolution of vertebrate body plans. This report shows that zebrafish have seven hox clusters. Phylogenetic analysis and genetic mapping suggest a chromosome doubling event, probably by whole genome duplication, after the divergence of ray-finned and lobe-finned fishes but before the teleost radiation. Thus, teleosts, the most species-rich group of vertebrates, appear to have more copies of these developmental regulatory genes than do mammals, despite less complexity in the anterior-posterior axis.

  2. The shape of the human lumbar vertebral canal A forma do canal vertebral lombar humano

    Directory of Open Access Journals (Sweden)

    Edmundo Zarzur

    1996-09-01

    Full Text Available Literature on the anatomy of the human vertebral column characterizes the shape of the lumbar vertebral canal as triangular. The purpose of the present study was to determine the precise shape of the lumbar vertebral canal. Ten lumbar vertebral columns of adult male cadavers were dissected. Two transverse sections were performed in the third lumbar vertebra. One section was performed at the level of the lower border of the ligamenta flava, and the other section was performed at the level of the pedicles. The shape of the lumbar vertebral canal at the level of the pedicles tends to be oval or circular, whereas the shape of the lumbar vertebral canal at the level of the lower border of the ligamenta flava is triangular. Thus, the shape of the human lumbar vertebral canal is not exclusively triangular, as reported in the literature. It is related to the level of the transversal section performed on the lumbar vertebra. This finding should be taken into consideration among factors involved in the spread of solutions introduced into the epidural space.A literatura sobre a anatomia da coluna vertebral descreve como sendo triangular o formato do canal vertebral na região lombar. O objetivo deste estudo é determinar a real forma do canal da coluna vertebral lombar.Dez colunas vertebrais de cadáveres de homens adultos foram dissecadas. Dois cortes transversais foram executados na terceira vértebra lombar. Um corte foi feito no nível das bordas inferiores de dois ligamentos amarelos vizinhos e o outro corte foi transversal, no nível dos pedículos. A forma do canal vertebral variou: no nível dos pedículos ela tende a ser oval ou circular e junto às bordas inferiores dos ligamentos amarelos passa a ser triangular. Portanto, a forma do canal vertebral lombar não é somente triangular; ela depende do nível em que se faz o corte transversal da vértebra. Estes achados devem ser levados em consideração entre os fatores envolvidos na difusão das

  3. Identification of QTL in soybean underlying resistance to herbivory by Japanese beetles (Popillia japonica, Newman).

    Science.gov (United States)

    Yesudas, C R; Sharma, H; Lightfoot, D A

    2010-07-01

    Soybean [Glycine max (L.) Merr.] was one of the most important legume crops in the world in 2010. Japanese beetles (JB; Popillia japonica, Newman) in the US were an introduced and potentially damaging insect pest for soybean. JBs are likely to spread across the US if global warming occurs. Resistance to JB in soybean was previously reported only in plant introductions. The aims here were to identify loci underlying resistance to JB herbivory in recombinant inbred lines (RILs) derived from the cross of Essex x Forrest cultivars (EF94) and to correlate those with loci with factors that confer insect resistance in soybean cultivars. The RIL population was used to map 413 markers, 238 satellite markers and 177 other DNA markers. Field data were from two environments over 2 years. Pest severity (PS) measured defoliation on a 0-9 scale. Pest incidence (PI) was the percentage of plants within each RIL with beetles on them. Antibiosis and antixenosis data were from feeding assays with detached leaves in petri plates. Five QTL were detected for the mean PS field trait (16% root knot nematode (LG F) but not other major loci underlying resistance to nematode or insect pests (LGs G, H and M).

  4. Invasive plant Alternanthera philoxeroides suffers more severe herbivory pressure than native competitors in recipient communities

    Science.gov (United States)

    Fan, Shufeng; Yu, Haihao; Dong, Xianru; Wang, Ligong; Chen, Xiuwen; Yu, Dan; Liu, Chunhua

    2016-11-01

    Host-enemy interactions are vital mechanisms that explain the success or failure of invasive plants in new ranges. We surveyed the defoliation of invasive Alternanthera philoxeroides and co-occurring native plants on two islands during different seasons over three consecutive years and measured the leaf nitrogen content and the C/N ratio of each plant species. To evaluate the effects of herbivory on A. philoxeroides, an herbivore exclosure experiment was conducted. We found that the mean defoliation of A. philoxeroides was higher than that of native plants, regardless of whether the dominant species was A. philoxeroides or native plants. A. philoxeroides defoliation increased significantly as the months progressed, whereas the defoliation of the total population of native plants was constant. The leaf nitrogen content was positively correlated with defoliation, and it was highest in A. philoxeroides. Additionally, A. philoxeroides in the herbivore exclusion treatment showed an increase in shoot biomass and total shoot length. Our study revealed that native generalist herbivores prefer the invasive plant to the natives because of the higher leaf nitrogen content. These results support the biotic resistance hypothesis, suggesting that native herbivore species can limit the population spread of invasive plants.

  5. Plant responses to insect herbivory: interactions between photosynthesis, reactive oxygen species and hormonal signalling pathways.

    Science.gov (United States)

    Kerchev, Pavel I; Fenton, Brian; Foyer, Christine H; Hancock, Robert D

    2012-02-01

    Under herbivore attack plants mount a defence response characterized by the accumulation of secondary metabolites and inhibitory proteins. Significant changes are observed in the transcriptional profiles of genes encoding enzymes of primary metabolism. Such changes have often been interpreted in terms of a requirement for an increased investment of resources to 'fuel' the synthesis of secondary metabolites. While enhanced secondary metabolism undoubtedly exerts an influence on primary metabolism, accumulating evidence suggests that rather than stimulating photosynthesis insect herbivory reduces photosynthetic carbon fixation and this response occurs by a re-programming of gene expression. Within this context, reactive oxygen species (ROS) and reductant/oxidant (redox) signalling play a central role. Accumulating evidence suggests that ROS signalling pathways are closely interwoven with hormone-signalling pathways in plant-insect interactions. Here we consider how insect infestation impacts on the stress signalling network through effects on ROS and cellular redox metabolism with particular emphasis on the roles of ROS in the plant responses to phloem-feeding insects.

  6. Treatment of osteoporotic vertebral compression fractures

    NARCIS (Netherlands)

    Klazen, C.A.H.

    2010-01-01

    In Chapter I, an outline of this thesis is given. In Chapter 2 we prospectively determined the natural course of pain in patients with conservatively treated acute osteoporotic vertebral compression fractures (VCF). In addition, we assessed the type of conservative therapy that these patients receiv

  7. Stakeholder participation in management of invasive vertebrates.

    Science.gov (United States)

    Ford-Thompson, Adriana E S; Snell, Carolyn; Saunders, Glen; White, Piran C L

    2012-04-01

    Stakeholders are increasingly involved in species conservation. We sought to understand what features of a participatory conservation program are associated with its ecological and social outcomes. We conducted a case study of the management of invasive vertebrates in Australia. Invasive vertebrates are a substantial threat to Australia's native species, and stakeholder participation in their management is often necessary for their control. First, we identified potential influences on the ecological and social outcomes of species conservation programs from the literature. We used this information to devise an interview questionnaire, which we administered to managers of 34 participatory invasive-vertebrate programs. Effects of invasive species were related to program initiator (agency or citizen), reasons for use of a participatory approach, and stakeholder composition. Program initiator was also related to the participation methods used, level of governance (i.e., governed by an agency or citizens), changes in stakeholder interactions, and changes in abundance of invasive species. Ecological and social outcomes were related to changes in abundance of invasive species and stakeholder satisfaction. We identified relations between changes in the number of participants, stakeholder satisfaction, and occurrence of conflict. Potential ways to achieve ecological and social goals include provision of governmental support (e.g., funding) to stakeholders and minimization of gaps in representation of stakeholder groups or individuals to, for example, increase conflict mitigation. Our findings provide guidance for increasing the probability of achieving ecological and social objectives in management of invasive vertebrates and may be applicable to other participatory conservation programs.

  8. Aquatic vertebrate locomotion : Wakes from body waves

    NARCIS (Netherlands)

    Videler, JJ; Muller, UK; Stamhuis, EJ

    1999-01-01

    Vertebrates swimming with undulations of the body and tail have inflection points where the curvature of the body changes from concave to convex or vice versa. These inflection paints travel down the body at the speed of the running wave of bending, In movements with increasing amplitudes, the body

  9. Light sensitivity in a vertebrate mechanoreceptor?

    NARCIS (Netherlands)

    Baker, G.E.; Grip, W.J. de; Turton, M.; Wagner, H.J.; Foster, R.G.; Douglas, R.H.

    2015-01-01

    Using immunohistochemistry and western blot analysis, we demonstrate that melanopsin is localised in cells around the central pore of lateral line neuromasts in the African clawed frog, Xenopus laevis. Since melanopsin is a known photoreceptor pigment with diverse functions in vertebrates, we sugges

  10. Opportunities and costs for preventing vertebrate extinctions

    DEFF Research Database (Denmark)

    Conde, Dalia Amor; Colchero, Fernando; Güneralp, Burak

    2015-01-01

    [2] . However, averting human-induced species extinctions within AZE sites requires enhanced planning tools to increase the chances of success [3] . Here, we assess the potential for ensuring the long-term conservation of AZE vertebrate species (157 mammals, 165 birds, 17 reptiles and 502 amphibians...

  11. Why can't vertebrates synthesize trehalose?

    Science.gov (United States)

    Argüelles, Juan-Carlos

    2014-10-01

    The non-reducing disaccharide trehalose is a singular molecule, which has been strictly conserved throughout evolution in prokaryotes (bacteria and archaea), lower eukaryotes, plants, and invertebrates, but is absent in vertebrates and-more specifically-in mammals. There are notable differences regarding the pivotal roles played by trehalose among distantly related organisms as well as in the specific metabolic pathways of trehalose biosynthesis and/or hydrolysis, and the regulatory mechanisms that control trehalose expression genes and enzymatic activities. The success of trehalose compared with that of other structurally related molecules is attributed to its exclusive set of physical properties, which account for its physiological roles and have also promoted important biotechnological applications. However, an intriguing question still remains: why are vertebrates in general, and mammals in particular, unable (or have lost the capacity) to synthesize trehalose? The search for annotated genomes of vertebrates reveals the absence of any functional trehalose synthase gene. Indeed, this is also true for the human genome, which contains, however, two genes encoding for isoforms of the hydrolytic activity (trehalase). Although we still lack a convincing answer, this striking difference might reflect the divergent evolutionary lineages followed by invertebrates and vertebrates. Alternatively, some clinical data point to trehalose as a toxic molecule when stored inside the human body.

  12. Neogene vertebrates from the Gargano Peninsula, Italy

    NARCIS (Netherlands)

    Freudenthal, M.

    1971-01-01

    Fissure-fillings in Mesozoic limestones in the Gargano Peninsula yield rich collections of fossil vertebrates, which are characterized by gigantism and aberrant morphology. Their age is considered to be Vallesian or Turolian. The special features of the fauna are probably due to isolation on an isla

  13. Physiology of cell volume regulation in vertebrates

    DEFF Research Database (Denmark)

    Hoffmann, Else K; Lambert, Ian H; Pedersen, Stine F

    2009-01-01

    and their regulation by, e.g., membrane deformation, ionic strength, Ca(2+), protein kinases and phosphatases, cytoskeletal elements, GTP binding proteins, lipid mediators, and reactive oxygen species, upon changes in cell volume. We also discuss the nature of the upstream elements in volume sensing in vertebrate...

  14. Extensive thoracolumbosacral vertebral osteomyelitis after Lemierre syndrome

    NARCIS (Netherlands)

    Kempen, D. H R; van Dijk, M.; Hoepelman, A. I M; Oner, F. C.; Verlaan, J. J.

    2015-01-01

    Purpose: To present a unique case of multilevel vertebral osteomyelitis after Lemierre syndrome. Methods: A previously healthy 27-year-old man presented in the Emergency Department in septic shock because of Lemierre syndrome for which he was subsequently treated with intravenous benzylpenicillin fo

  15. Pleistocene vertebrates of the Yukon Territory

    Science.gov (United States)

    Harington, C. R.

    2011-08-01

    Unglaciated parts of the Yukon constitute one of the most important areas in North America for yielding Pleistocene vertebrate fossils. Nearly 30 vertebrate faunal localities are reviewed spanning a period of about 1.6 Ma (million years ago) to the close of the Pleistocene some 10 000 BP (radiocarbon years before present, taken as 1950). The vertebrate fossils represent at least 8 species of fishes, 1 amphibian, 41 species of birds and 83 species of mammals. Dominant among the large mammals are: steppe bison ( Bison priscus), horse ( Equus sp.), woolly mammoth ( Mammuthus primigenius), and caribou ( Rangifer tarandus) - signature species of the Mammoth Steppe fauna ( Fig. 1), which was widespread from the British Isles, through northern Europe, and Siberia to Alaska, Yukon and adjacent Northwest Territories. The Yukon faunas extend from Herschel Island in the north to Revenue Creek in the south and from the Alaskan border in the west to Ketza River in the east. The Yukon holds evidence of the earliest-known people in North America. Artifacts made from bison, mammoth and caribou bones from Bluefish Caves, Old Crow Basin and Dawson City areas show that people had a substantial knowledge of making and using bone tools at least by 25 000 BP, and possibly as early as 40 000 BP. A suggested chronological sequence of Yukon Pleistocene vertebrates ( Table 1) facilitates comparison of selected faunas and indicates the known duration of various taxa.

  16. Benign nontraumatic osteolytic vertebral collapse simulating malignancy

    Energy Technology Data Exchange (ETDEWEB)

    Sattari, Azadeh [Hopital Lariboisiere, Department of Musculoskeletal Radiology, Paris Cedex 10 (France); Quillard, Alain [Hopital Lariboisiere, Department of Pathology, Paris Cedex 10 (France); Laredo, Jean-Denis [Hopital Lariboisiere, Department of Musculoskeletal Radiology, Paris Cedex 10 (France); University of Pennsylvania Health System, Department of Radiology, Philadelphia, PA (United States)

    2008-03-15

    This study described the imaging features of a distinctive pattern of biopsy-proven benign non-traumatic vertebral collapse (VC) that can mimic malignancy. Among 240 patients referred with painful VC over a 10-year period, we retrospectively selected 15 cases of benign VC which simulated malignancy, due to cortical bone destruction on radiographs. The diagnosis of benign origin was documented by percutaneous biopsy and 12-months of follow-up. Radiographs, CT and MR images of the spine were reviewed. Findings suggestive of malignancy included destruction involving the anterolateral cortex, posterior cortex and pedicles of the vertebral body (46%,15% and 15% respectively) at CT, epidural soft-tissue masses on CT (23%) and MR images (21%), and diffuse low signal-intensity (SI) of the vertebral body (50%) and pedicles (79%) on T1-weighted images. Features suggestive of a benign origin included an intravertebral vacuum phenomenon on radiographs and CT (13%), fracture lines within the vertebral body (92%) or pedicles (62%) at CT and presence an intravertebral area of high SI on T2-weighted images (93%). Benign non-traumatic osteolytic VC can simulate malignancy on radiographs. The features, above mentioned on CT and MR suggestive of a benign VC, are useful in interpreting biopsy results of such lesions and avoiding unnecessary repeat biopsy. (orig.)

  17. The Evolution of Line-1 in Vertebrates.

    Science.gov (United States)

    Boissinot, Stéphane; Sookdeo, Akash

    2016-10-19

    The abundance and diversity of the LINE-1 (L1) retrotransposon differ greatly among vertebrates. Mammalian genomes contain hundred of thousands L1s that have accumulated since the origin of mammals. A single group of very similar elements is active at a time in mammals, thus a single lineage of active families has evolved in this group. In contrast, non-mammalian genomes (fish, amphibians, reptiles) harbor a large diversity of concurrently transposing families, which are all represented by very small number of recently inserted copies. Why the pattern of diversity and abundance of L1 is so different among vertebrates remains unknown. To address this issue, we performed a detailed analysis of the evolution of active L1 in 14 mammals and in three non-mammalian vertebrate model species. We examined the evolution of base composition and codon bias, the general structure, and the evolution of the different domains of L1 (5'UTR, ORF1, ORF2, 3'UTR). L1s differ substantially in length, base composition and structure among vertebrates. The most variation is found in the 5'UTR, which is longer in amniotes, and in the ORF1, which tend to evolve faster in mammals. The highly divergent L1 families of lizard, frog and fish share species-specific features suggesting they are subjected to the same functional constraints imposed by their host. The relative conservation of the 5'UTR and ORF1 in non-mammalian vertebrates suggests that the repression of transposition by the host does not act in a sequence specific manner and did not result in an arms race, as is observed in mammals.

  18. A Case Report: Balloon Occlusion Of Vertebral Artery In A Giant Vertebral Artery Aneurysm

    Directory of Open Access Journals (Sweden)

    K. Edraki

    2005-08-01

    Full Text Available Introduction & Background: True aneurysms of extra cranial vertebral arteries are rare. The usual pathogenesis of aneurysms in this location is either penetrating or blunt trauma with resultant pseudo- aneurysm formation. We report a patient with a presumed pseudo-aneurysm of the extra- cranial vertebral artery presenting with painful neck mass, without obvious history of trauma. Case description: A 59-year old man presented with painful left lateral neck mass from 3 month ago with a bruit over it on physical examination. Patient had a history of long term anticoagulant therapy because of chronic lower extremity DVT. Patient was referred to our DSA (Department for angiography. After color Doppler US, CT scan and MR-angiography were performed and a giant aneurysm in left vertebral artery was detected. The lesion was successfully treated by an endovascular technique of balloon occlusion of the verte-bral artery.

  19. Varied overstrain injuries of the vertebral column conditioned by evolution

    Energy Technology Data Exchange (ETDEWEB)

    Kohlbach, W.

    1983-08-01

    During physiological growth of the juvenile vertebral column, various stages of stability occur which are characterized by the condition of the marginal rim of the vertebral bodies. If the vertebral juvenile column is overstrained, these variations in stability results in a variety of damage to vertebral bodies and vertebral disks. One of these lesions corresponds to Scheuermann's disease (osteochondrosis of vertebral epiphyses in juveniles). Damage of the vertebral column due to overstrain can occur only if the overstrain is applied in upright position. Since Man alone can damage his vertebral column in upright position (as a result of his evolutionary development), Scheuermann's thesis is confirmed that Scheuermann's disease is confined to Man. Spondylolysis/spondylolisthesis is also a damage caused by overstrain. Here, too, the damage can occur only if the load is exercised in upright position, with the exception of a slanted positioning of the intervertebral components.

  20. An Inquiry into Acupuncture Treatment on Cervical Vertebral Disease

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    @@ Introduction: The cervical vertebral diseases are the diseases of cervical osteoarticular and ligament hypertrophy that cause stenosis of vertebral canals and intervertebral foraminae and compression of nerve roots or cervical segments.

  1. Relationship between New Osteoporotic Vertebral Fracture and Instrumented Lumbar Arthrodesis

    OpenAIRE

    Kim, Bung-Hak; Choi, Dong-Hyuk; Jeon, Seong-Hun; Choi, Yong-Soo

    2010-01-01

    Study Design Retrospective study. Purpose To evaluate the relationship between a new osteoporotic vertebral fracture and instrumented lumbar arthrodesis. Overview of Literature In contrast to the growing recognition of the importance of adjacent segment disease after lumbar arthrodesis, relatively little attention has been paid to the relationship between osteoporotic vertebral fractures and instrumented lumbar arthrodesis. Methods Twenty five patients with a thoracolumbar vertebral fracture ...

  2. Vertebral Augmentation Involving Vertebroplasty or Kyphoplasty for Cancer-Related Vertebral Compression Fractures: A Systematic Review

    Science.gov (United States)

    2016-01-01

    Background Cancers that metastasize to the spine and primary cancers such as multiple myeloma can result in vertebral compression fractures or instability. Conservative strategies, including bed rest, bracing, and analgesic use, can be ineffective, resulting in continued pain and progressive functional disability limiting mobility and self-care. Surgery is not usually an option for cancer patients in advanced disease states because of their poor medical health or functional status and limited life expectancy. The objectives of this review were to evaluate the effectiveness and safety of percutaneous image-guided vertebral augmentation techniques, vertebroplasty and kyphoplasty, for palliation of cancer-related vertebral compression fractures. Methods We performed a systematic literature search for studies on vertebral augmentation of cancer-related vertebral compression fractures published from January 1, 2000, to October 2014; abstracts were screened by a single reviewer. For those studies meeting the eligibility criteria, full-text articles were obtained. Owing to the heterogeneity of the clinical reports, we performed a narrative synthesis based on an analytical framework constructed for the type of cancer-related vertebral fractures and the diversity of the vertebral augmentation interventions. Results The evidence review identified 3,391 citations, of which 111 clinical reports (4,235 patients) evaluated the effectiveness of vertebroplasty (78 reports, 2,545 patients) or kyphoplasty (33 reports, 1,690 patients) for patients with mixed primary spinal metastatic cancers, multiple myeloma, or hemangiomas. Overall the mean pain intensity scores often reported within 48 hours of vertebral augmentation (kyphoplasty or vertebroplasty), were significantly reduced. Analgesic use, although variably reported, usually involved parallel decreases, particularly in opioids, and mean pain-related disability scores were also significantly improved. In a randomized controlled

  3. Vertebral Augmentation Involving Vertebroplasty or Kyphoplasty for Cancer-Related Vertebral Compression Fractures: An Economic Analysis

    Science.gov (United States)

    2016-01-01

    Background Untreated vertebral compression fractures can have serious clinical consequences and impose a considerable impact on patients' quality of life and on caregivers. Since non-surgical management of these fractures has limited effectiveness, vertebral augmentation procedures are gaining acceptance in clinical practice for pain control and fracture stabilization. The objective of this analysis was to determine the cost-effectiveness and budgetary impact of kyphoplasty or vertebroplasty compared with non-surgical management for the treatment of vertebral compression fractures in patients with cancer. Methods We performed a systematic review of health economic studies to identify relevant studies that compare the cost-effectiveness of kyphoplasty or vertebroplasty with non-surgical management for the treatment of vertebral compression fractures in adults with cancer. We also performed a primary cost-effectiveness analysis to assess the clinical benefits and costs of kyphoplasty or vertebroplasty compared with non-surgical management in the same population. We developed a Markov model to forecast benefits and harms of treatments, and corresponding quality-adjusted life years and costs. Clinical data and utility data were derived from published sources, while costing data were derived using Ontario administrative sources. We performed sensitivity analyses to examine the robustness of the results. In addition, a 1-year budget impact analysis was performed using data from Ontario administrative sources. Two scenarios were explored: (a) an increase in the total number of vertebral augmentation procedures performed among patients with cancer in Ontario, maintaining the current proportion of kyphoplasty versus vertebroplasty; and (b) no increase in the total number of vertebral augmentation procedures performed among patients with cancer in Ontario but an increase in the proportion of kyphoplasties versus vertebroplasties. Results The base case considered each of

  4. Anatomia do sulco da artéria vertebral Vertebral artery groove anatomy

    Directory of Open Access Journals (Sweden)

    Max Franco de Carvalho

    2009-01-01

    Full Text Available INTRODUÇÃO: Diversas técnicas cirúrgicas têm sido realizadas na região craniocervical devido a diversas patologias. Durante o acesso cirúrgico a essa região existe um risco potencial de lesão iatrogênica da artéria vertebral, relacionado ao acesso lateral amplo e à avaliação inadequada da anatomia local. Variações no trajeto da artéria vertebral ocasionam maior risco de lesão vascular. O estudo pré-operatório por imagem da anatomia da artéria vertebral e do seu sulco tem sido realizado para aumentar a segurança cirúrgica. OBJETIVO: Estudar a morfometria da artéria vertebral no atlas através da tomografia computadorizada do sulco da artéria vertebral (SAV em 30 atlas isolados de cadáveres. MATERIAIS E MÉTODOS: O SAV e suas relações com a linha média foram avaliados através de oito medidas lineares e duas angulares, bilateralmente. A média, valor máximo e mínimo, e desvio padrão foram calculados para cada parâmetro. RESULTADOS: O SAV apresentou uma maior largura e maior espessura do lado esquerdo (pINTRODUCTION: Several surgical techniques have been carried through in the skull-cervical region due to various pathologies. During the surgical access to this region, a potential risk of iatrogenic injury of the vertebral artery exists, related to extended lateral access and the inadequate evaluation of the local anatomy. Variations in the groove of the vertebral artery lead to a greater risk of vascular injury during surgery. Preoperative image study of the vertebral artery anatomy and its groove has been realized to enhance surgical safety. OBJECTIVE: to study the morphometry of atlas vertebral artery on computed tomography scan images of the vertebral artery groove (VAG in 30 dry atlas. METHODS: VAG and its relationship with the midline were evaluated through eight linear and two angular measures, bilaterally. The average, maximum and minimum values, and standard deviation were calculated for each parameter

  5. Mechanisms driving diversity-productivity relationships differ between exotic and native communities and are affected by gastropod herbivory.

    Science.gov (United States)

    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.

  6. Greening of the Arctic: Partitioning Warming Versus Reindeer Herbivory for Willow Populations on Yamal Peninsula, Northwest Siberia

    Science.gov (United States)

    Forbes, B. C.; Macias-Fauria, M.; Zetterberg, P.; Kumpula, T.

    2012-12-01

    Arctic warming has been linked to observed increases in tundra shrub cover and growth in recent decades on the basis of significant relationships between deciduous shrub growth/biomass and temperature. These vegetation trends have been linked to Arctic sea-ice decline and thus to the sea-ice/albedo feedback known as Arctic amplification. However, the interactions between climate, sea ice, tundra vegetation and herbivores remain poorly understood. Recently we revealed a 50-year growth response over a >100,000 km2 area to a rise in summer temperature for willow (Salix lanata), one the most abundant shrub genera at and north of the continental treeline and an important source of reindeer forage in spring, summer and autumn. We demonstrated that whereas plant productivity is related to sea ice in late spring, the growing season peak responds to persistent synoptic-scale air masses over West Siberia associated with Fennoscandian weather systems through the Rossby wave train. Substrate was important for biomass accumulation, yet a strong correlation between growth and temperature encompasses all observed soil types. Vegetation was especially responsive to temperature in early summer. However, the role of herbivory was not addressed. The present data set explores the relationship between long-term herbivory and growth trends of shrubs experiencing warming in recent decades. Semi-domestic reindeer managed by indigenous Nenets nomads occur at high densities in summer on exposed ridge tops and graze heavily on prostrate and low erect willows. A few meters away in moderately sloped landslides tall willows remain virtually ungrazed as their canopies have grown above the browse line of ca. 180 cm. Here we detail the responses of neighboring shrub populations with and without intensive herbivory yet subject to the same decadal warming trend.

  7. Sediments influence accumulation of two macroalgal species through novel but differing interactions with nutrients and herbivory

    Science.gov (United States)

    Clausing, Rachel J.; Bittick, Sarah Joy; Fong, Caitlin R.; Fong, Peggy

    2016-12-01

    Despite increasing concern that sediment loads from disturbed watersheds facilitate algal dominance on tropical reefs, little is known of how sediments interact with two primary drivers of algal communities, nutrients and herbivory. We examined the effects of sediment loads on the thalli of two increasingly abundant genera of macroalgae, Galaxaura and Padina, in a bay subject to terrestrial sediment influx in Mo'orea, French Polynesia. Field experiments examining (1) overall effects of ambient sediments and (2) interacting effects of sediments (ambient/removal) and herbivores (caged/uncaged) demonstrated that sediments had strong but opposite effects on both species' biomass accumulation. Sediment removal increased accumulation of Padina boryana Thivy 50% in the initial field experiment but had no effect in the second; rather, in a novel interaction, herbivores overcompensated for increases in tissue nutrient stores that occurred with sediments loads, likely by preferential consumption of nutrient-rich meristematic tissues. Despite negative effects of sediments on biomass, Padina maintained rapid growth across treatments in both experiments. In contrast, positive growth in Galaxaura divaricata Kjellman only occurred with ambient sediment loads. In mesocosm experiments testing interactions of added nutrients and sediments on growth, Galaxaura grew at equivalent rates with sediments (collected from thalli on the reef) as with additions of nitrate and phosphate, suggesting sediments provide a nutrient subsidy. For Padina, however, the only effect was a 50% reduction in growth with sediment. Overall, retention of thallus sediments creates a positive feedback that Galaxaura appears to require to sustain net growth, while Padina merely tolerates sediments. These results indicate that sediments can modify nutrient and herbivore control of algae in ways that differ among species, with the potential for strong and unexpected effects on the abundance and composition of

  8. The impact of the absence of aliphatic glucosinolates on insect herbivory in Arabidopsis.

    Directory of Open Access Journals (Sweden)

    Jules Beekwilder

    Full Text Available Aliphatic glucosinolates are compounds which occur in high concentrations in Arabidopsis thaliana and other Brassicaceae species. They are important for the resistance of the plant to pest insects. Previously, the biosynthesis of these compounds was shown to be regulated by transcription factors MYB28 and MYB29. We now show that MYB28 and MYB29 are partially redundant, but in the absence of both, the synthesis of all aliphatic glucosinolates is blocked. Untargeted and targeted biochemical analyses of leaf metabolites showed that differences between single and double knock-out mutants and wild type plants were restricted to glucosinolates. Biosynthesis of long-chain aliphatic glucosinolates was blocked by the myb28 mutation, while short-chain aliphatic glucosinolates were reduced by about 50% in both the myb28 and the myb29 single mutants. Most remarkably, all aliphatic glucosinolates were completely absent in the double mutant. Expression of glucosinolate biosynthetic genes was slightly but significantly reduced by the single myb mutations, while the double mutation resulted in a drastic decrease in expression of these genes. Since the myb28myb29 double mutant is the first Arabidopsis genotype without any aliphatic glucosinolates, we used it to establish the relevance of aliphatic glucosinolate biosynthesis to herbivory by larvae of the lepidopteran insect Mamestra brassicae. Plant damage correlated inversely to the levels of aliphatic glucosinolates observed in those plants: Larval weight gain was 2.6 fold higher on the double myb28myb29 mutant completely lacking aliphatic glucosinolates and 1.8 higher on the single mutants with intermediate levels of aliphatic glucosinolates compared to wild type plants.

  9. The impact of the absence of aliphatic glucosinolates on insect herbivory in Arabidopsis.

    Science.gov (United States)

    Beekwilder, Jules; van Leeuwen, Wessel; van Dam, Nicole M; Bertossi, Monica; Grandi, Valentina; Mizzi, Luca; Soloviev, Mikhail; Szabados, Laszlo; Molthoff, Jos W; Schipper, Bert; Verbocht, Hans; de Vos, Ric C H; Morandini, Piero; Aarts, Mark G M; Bovy, Arnaud

    2008-04-30

    Aliphatic glucosinolates are compounds which occur in high concentrations in Arabidopsis thaliana and other Brassicaceae species. They are important for the resistance of the plant to pest insects. Previously, the biosynthesis of these compounds was shown to be regulated by transcription factors MYB28 and MYB29. We now show that MYB28 and MYB29 are partially redundant, but in the absence of both, the synthesis of all aliphatic glucosinolates is blocked. Untargeted and targeted biochemical analyses of leaf metabolites showed that differences between single and double knock-out mutants and wild type plants were restricted to glucosinolates. Biosynthesis of long-chain aliphatic glucosinolates was blocked by the myb28 mutation, while short-chain aliphatic glucosinolates were reduced by about 50% in both the myb28 and the myb29 single mutants. Most remarkably, all aliphatic glucosinolates were completely absent in the double mutant. Expression of glucosinolate biosynthetic genes was slightly but significantly reduced by the single myb mutations, while the double mutation resulted in a drastic decrease in expression of these genes. Since the myb28myb29 double mutant is the first Arabidopsis genotype without any aliphatic glucosinolates, we used it to establish the relevance of aliphatic glucosinolate biosynthesis to herbivory by larvae of the lepidopteran insect Mamestra brassicae. Plant damage correlated inversely to the levels of aliphatic glucosinolates observed in those plants: Larval weight gain was 2.6 fold higher on the double myb28myb29 mutant completely lacking aliphatic glucosinolates and 1.8 higher on the single mutants with intermediate levels of aliphatic glucosinolates compared to wild type plants.

  10. Seagrass Herbivory Levels Sustain Site-Fidelity in a Remnant Dugong Population.

    Directory of Open Access Journals (Sweden)

    Elrika D'Souza

    Full Text Available Herds of dugong, a largely tropical marine megaherbivore, are known to undertake long-distance movements, sequentially overgrazing seagrass meadows in their path. Given their drastic declines in many regions, it is unclear whether at lower densities, their grazing is less intense, reducing their need to travel between meadows. We studied the effect of the feeding behaviour of a small dugong population in the Andaman and Nicobar archipelago, India to understand how small isolated populations graze seagrasses. In the seven years of our observation, all recorded dugongs travelled either solitarily or in pairs, and their use of seagrasses was limited to 8 meadows, some of which were persistently grazed. These meadows were relatively large, contiguous and dominated by short-lived seagrasses species. Dugongs consumed approximately 15% of meadow primary production, but there was a large variation (3-40% of total meadow production in consumption patterns between meadows. The impact of herbivory was relatively high, with shoot densities c. 50% higher inside herbivore exclosures than in areas exposed to repeated grazing. Our results indicate that dugongs in the study area repeatedly graze the same meadows probably because the proportion of primary production consumed reduces shoot density to levels that are still above values that can trigger meadow abandonment. This ability of seagrasses to cope perhaps explains the long-term site fidelity shown by individual dugongs in these meadows. The fact that seagrass meadows in the archipelago are able to support dugong foraging requirements allows us to clearly identify locations where this remnant population persists, and where urgent management efforts can be directed.

  11. Interspecific variation in compensatory regrowth to herbivory associated with soil nutrients in three Ficus (Moraceae saplings.

    Directory of Open Access Journals (Sweden)

    Jin Zhao

    Full Text Available Plant compensatory regrowth is an induced process that enhances plant tolerance to herbivory. Plant behavior against herbivores differs between species and depends on resource availability, thus making general predictions related to plant compensatory regrowth difficult. To understand how soil nutrients determine the degree of compensatory regrowth for different plant species, we selected saplings of three Ficus species and treated with herbivore insects and artificial injury in both glasshouse conditions and in the field at two soil nutrient levels. Compensatory regrowth was calculated by biomass, relative growth rate and photosynthetic characteristics. A similar pattern was found in both the glasshouse and in the field for species F. hispida, where overcompensatory regrowth was triggered only under fertile conditions, and full compensatory regrowth occurred under infertile conditions. For F. auriculata, overcompensatory regrowth was stimulated only under infertile conditions and full compensatory regrowth occurred under fertile conditions. Ficus racemosa displayed full compensatory regrowth in both soil nutrient levels, but without overcompensatory regrowth following any of the treatments. The three Ficus species differed in biomass allocation following herbivore damage and artificial injury. The root/shoot ratio of F. hispida decreased largely following herbivore damage and artificial injury, while the root/shoot ratio for F. auriculata increased against damage treatments. The increase of shoot and root size for F. hispida and F. auriculata, respectively, appeared to be caused by a significant increase in photosynthesis. The results indicated that shifts in biomass allocation and increased photosynthesis are two of the mechanisms underlying compensatory regrowth. Contrasting patterns among the three Ficus species suggest that further theoretical and empirical work is necessary to better understand the complexity of the plant responses to

  12. Short-term herbivory has long-term consequences in warmed and ambient high Arctic tundra

    Science.gov (United States)

    Little, Chelsea J.; Cutting, Helen; Alatalo, Juha; Cooper, Elisabeth

    2017-02-01

    , underlying ecosystem processes are beginning to change. In addition, even short bouts of intense herbivory can have long-term consequences for some species in these communities.

  13. Herbivory and drought interact to enhance spatial patterning and diversity in a savanna understory.

    Science.gov (United States)

    Porensky, Lauren M; Wittman, Sarah E; Riginos, Corinna; Young, Truman P

    2013-10-01

    The combination of abiotic stress and consumer stress can have complex impacts on plant community structure. Effective conservation and management of semi-arid ecosystems requires an understanding of how different stresses interact to structure plant communities. We explored the separate and combined impacts of episodic drought, livestock grazing, and wild ungulate herbivory on species co-occurrence and diversity patterns in a relatively productive, semi-arid Acacia savanna. Specifically, we analyzed 9 years of biannual plant community data from the Kenya long-term exclosure experiment, a broad-scale manipulative experiment that has excluded different combinations of large mammalian herbivores from 18 4-ha plots since 1995. During droughts, we observed low species diversity and random species co-occurrence patterns. However, when rain followed a major drought, areas exposed to moderate cattle grazing displayed high species diversity and evidence of significant species aggregation. These patterns were not apparent in the absence of cattle, even if other large herbivores were present. To explore possible mechanisms, we examined patterns separately for common and rare species. We found that aggregation patterns were likely driven by rare species responding similarly to the availability of open micro-sites. Our results indicate that in a productive, fire-suppressed savanna, the combination of periodic drought and moderate cattle grazing can enhance plant biodiversity and fine-scale spatial heterogeneity by opening up space for species that are otherwise rare or cryptic. Our findings also emphasize that domestic herbivores can have significantly stronger impacts on plant community dynamics than wild herbivores, even in an ecosystem with a long history of grazing.

  14. Interspecific variation in compensatory regrowth to herbivory associated with soil nutrients in three Ficus (Moraceae) saplings.

    Science.gov (United States)

    Zhao, Jin; Chen, Jin

    2012-01-01

    Plant compensatory regrowth is an induced process that enhances plant tolerance to herbivory. Plant behavior against herbivores differs between species and depends on resource availability, thus making general predictions related to plant compensatory regrowth difficult. To understand how soil nutrients determine the degree of compensatory regrowth for different plant species, we selected saplings of three Ficus species and treated with herbivore insects and artificial injury in both glasshouse conditions and in the field at two soil nutrient levels. Compensatory regrowth was calculated by biomass, relative growth rate and photosynthetic characteristics. A similar pattern was found in both the glasshouse and in the field for species F. hispida, where overcompensatory regrowth was triggered only under fertile conditions, and full compensatory regrowth occurred under infertile conditions. For F. auriculata, overcompensatory regrowth was stimulated only under infertile conditions and full compensatory regrowth occurred under fertile conditions. Ficus racemosa displayed full compensatory regrowth in both soil nutrient levels, but without overcompensatory regrowth following any of the treatments. The three Ficus species differed in biomass allocation following herbivore damage and artificial injury. The root/shoot ratio of F. hispida decreased largely following herbivore damage and artificial injury, while the root/shoot ratio for F. auriculata increased against damage treatments. The increase of shoot and root size for F. hispida and F. auriculata, respectively, appeared to be caused by a significant increase in photosynthesis. The results indicated that shifts in biomass allocation and increased photosynthesis are two of the mechanisms underlying compensatory regrowth. Contrasting patterns among the three Ficus species suggest that further theoretical and empirical work is necessary to better understand the complexity of the plant responses to herbivore damage.

  15. Testing for the effects and consequences of mid paleogene climate change on insect herbivory.

    Directory of Open Access Journals (Sweden)

    Torsten Wappler

    Full Text Available BACKGROUND: The Eocene, a time of fluctuating environmental change and biome evolution, was generally driven by exceptionally warm temperatures. The Messel (47.8 Ma and Eckfeld (44.3 Ma deposits offer a rare opportunity to take a census of two, deep-time ecosystems occurring during a greenhouse system. An understanding of the long-term consequences of extreme warming and cooling events during this interval, particularly on angiosperms and insects that dominate terrestrial biodiversity, can provide insights into the biotic consequences of current global climatic warming. METHODOLOGY/PRINCIPAL FINDINGS: We compare insect-feeding damage within two middle Eocene fossil floras, Messel and Eckfeld, in Germany. From these small lake deposits, we studied 16,082 angiosperm leaves and scored each specimen for the presence or absence of 89 distinctive and diagnosable insect damage types (DTs, each of which was allocated to a major functional feeding group, including four varieties of external foliage feeding, piercing- and-sucking, leaf mining, galling, seed predation, and oviposition. Methods used for treatment of presence-absence data included general linear models and standard univariate, bivariate and multivariate statistical techniques. CONCLUSIONS/SIGNIFICANCE: Our results show an unexpectedly high diversity and level of insect feeding than comparable, penecontemporaneous floras from North and South America. In addition, we found a higher level of herbivory on evergreen, rather than deciduous taxa at Messel. This pattern is explained by a ca. 2.5-fold increase in atmospheric CO(2 that overwhelmed evergreen antiherbivore defenses, subsequently lessened during the more ameliorated levels of Eckfeld times. These patterns reveal important, previously undocumented features of plant-host and insect-herbivore diversification during the European mid Eocene.

  16. Algal growth and species composition under experimental control of herbivory, phosphorus and coral abundance in Glovers Reef, Belize.

    Science.gov (United States)

    McClanahan, T R; Cokos, B A; Sala, E

    2002-06-01

    The proliferation of algae on disturbed coral reefs has often been attributed to (1) a loss of large-bodied herbivorous fishes, (2) increases in sea water nutrient concentrations, particularly phosphorus, and (3) a loss of hard coral cover or a combination of these and other factors. We performed replicated small-scale caging experiments in the offshore lagoon of Glovers Reef atoll, Belize where three treatments had closed-top (no large-bodied herbivores) and one treatment had open-top cages (grazing by large-bodied herbivores). Closed-top treatments simulated a reduced-herbivory situation, excluding large fishes but including small herbivorous fishes such as damselfishes and small parrotfishes. Treatments in the closed-top cages included the addition of high phosphorus fertilizer, live branches of Acropora cervicornis and a third unmanipulated control treatment. Colonization, algal biomass and species composition on dead A. palmata "plates" were studied weekly for 50 days in each of the four treatments. Fertilization doubled the concentration of phosphorus from 0.35 to 0.77 microM. Closed-top cages, particularly the fertilizer and A. cervicornis additions, attracted more small-bodied parrotfish and damselfish than the open-top cages such that there was moderate levels of herbivory in closed-top cages. The open-top cages did, however, have a higher abundance of the chemically and morphologically defended erect algal species including Caulerpa cupressoides, Laurencia obtusa, Dictyota menstrualis and Lobophora variegata. The most herbivore-resistant calcareous green algae (i.e. Halimeda) were, however, uncommon in all treatments. Algal biomass increased and fluctuated simultaneously in all treatments over time, but algal biomass, as measured by wet, dry and decalcified weight, did not differ greatly between the treatments with only marginally higher biomass (p cervicornis suppressed algal colonization compared to the unmanipulated controls. Instead, the herbivore

  17. Coupling above and below ground gas measurements to understand greenhouse gas production in the soil profile

    Science.gov (United States)

    Nickerson, Nick; Creelman, Chance

    2016-04-01

    Natural and anthropogenic changes in climate have the potential to significantly affect the Earth's natural greenhouse gas balances. To understand how these climatic changes will manifest in a complex biological, chemical and physical system, a process-based understanding of the production and consumption of greenhouse gases in soils is critical. Commonly, both chamber methods and gradient-based approaches are used to estimate greenhouse gas flux from the soil to the atmosphere. Each approach offers benefits, but not surprisingly, comes with a list of drawbacks. Chambers are easily deployed on the surface without significant disturbance to the soil, and can be easily spatially replicated. However the high costs of automated chamber systems and the inability to partition fluxes by depth are potential downfalls. The gradient method requires a good deal of disturbance for installation, however it also offers users spatiotemporally resolved flux estimates at a reasonable price point. Researchers widely recognize that the main drawback of the gradient approach is the requirement to estimate diffusivity using empirical models based on studies of specific soils or soil types. These diffusivity estimates can often be off by several orders of magnitude, yielding poor flux estimates. Employing chamber and gradient methods in unison allows for in-situ estimation of the diffusion coefficient, and therefore improves gradient-based estimates of flux. A dual-method approach yields more robust information on the temporal dynamics and depth distribution of greenhouse gas production and consumption in the soil profile. Here we present a mathematical optimization framework that allows these complimentary measurement techniques to yield more robust information than a single technique alone. We then focus on how it can be used to improve the process-based understanding of greenhouse gas production in the soil profile.

  18. RF Tomography for Below-Ground Imaging of Extended Areas and Close-in Sensing

    Science.gov (United States)

    2010-07-01

    23:21:03 UTC from IEEE Xplore . Restrictions apply. 498 IEEE GEOSCIENCE AND REMOTE SENSING LETTERS, VOL. 7, NO. 3, JULY 2010 investigation region D...targets Authorized licensed use limited to: WASHINGTON UNIVERSITY LIBRARIES. Downloaded on August 16,2010 at 23:21:03 UTC from IEEE Xplore . Restrictions...Authorized licensed use limited to: WASHINGTON UNIVERSITY LIBRARIES. Downloaded on August 16,2010 at 23:21:03 UTC from IEEE Xplore . Restrictions apply

  19. Hot Cell Liners Category of Transuranic Waste Stored Below Ground within Area G

    Energy Technology Data Exchange (ETDEWEB)

    Jones, Robert Wesley [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Hargis, Kenneth Marshall [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2014-09-01

    A large wildfire called the Las Conchas Fire burned large areas near Los Alamos National Laboratory (LANL) in 2011 and heightened public concern and news media attention over transuranic (TRU) waste stored at LANL’s Technical Area 54 (TA-54) Area G waste management facility. The removal of TRU waste from Area G had been placed at a lower priority in budget decisions for environmental cleanup at LANL because TRU waste removal is not included in the March 2005 Compliance Order on Consent (Reference 1) that is the primary regulatory driver for environmental cleanup at LANL. The Consent Order is an agreement between LANL and the New Mexico Environment Department (NMED) that contains specific requirements and schedules for cleaning up historical contamination at the LANL site. After the Las Conchas Fire, discussions were held by the U.S. Department of Energy (DOE) with the NMED on accelerating TRU waste removal from LANL and disposing it at the Waste Isolation Pilot Plant (WIPP). This report summarizes available information on the origin, configuration, and composition of the waste containers within the Hot Cell Liners category; their physical and radiological characteristics; the results of the radioassays; and the justification to reclassify the five containers as LLW rather than TRU waste.

  20. Tracing {sup 13}C reveals the below ground connection between trees and fungi

    Energy Technology Data Exchange (ETDEWEB)

    Siegwolf, R.T.W.; Steinmann, K.; Saurer, M.; Koerner, Ch.

    2003-03-01

    Freshly assimilated atmospheric CO{sub 2} is transferred as sugars from the leaves into the whole organism. Since mycorrhiza fungi and tree roots are in an intensive symbiosis, the fungi provide important information about the tree internal carbon distribution. (author)

  1. Picturing Adoption of Below-Ground Biodiversity Technologies among Smallholder Farmers around Mabira Forest, Uganda

    Directory of Open Access Journals (Sweden)

    Isabirye, BE.

    2010-01-01

    Full Text Available Faced with a multitude of soil and water amendment technologies, farmers have the task of choosing the technologies to adopt for ensuring subsistence and income sustainability. In 2008, a study to characterize the farmers was conducted around Mabira Forest, to assess the adoption of soil technologies fostering Belowground Biodiversity (BGBD. Eighty-four households (38 participating and 46 non-participants from four villages were randomly selected and interviewed. Results showed that the adoption pattern was significantly driven by farm size, labor, household size, age and wealth status of the house. Also important were farm location, gender of household head, primary occupation, soil and water conservation technologies training, land tenure, and social capital. For the few current adopters, there was a perceived increase in labor demand but overall productivity was higher, partly resulting from increased crop productivity due to soil fertility enhancement and soil structure modification. It is therefore concluded that, around Mabira forest, BGBD technologies will be adopted by farming households with sufficient land, labor and social capital.

  2. Alternations of Structure and Functional Activity of Below Ground Microbial Communities at Elevated Atmospheric Carbon Dioxide

    Energy Technology Data Exchange (ETDEWEB)

    He, Zhili; Xu, Meiying; Deng, Ye; Kang, Sanghoon; Wu, Liyou; Van Nostrand, Joy D.; Hobbie, Sarah E.; Reich, Peter B.; Zhou, Jizhong

    2010-05-17

    The global atmospheric concentration of CO2 has increased by more than 30percent since the industrial revolution. Although the stimulating effects of elevated CO2 (eCO2) on plant growth and primary productivity have been well studied, its influences on belowground microbial communities are poorly understood and controversial. In this study, we showed a significant change in the structure and functional potential of soil microbial communities at eCO2 in a grassland ecosystem, the BioCON (Biodiversity, CO2 and Nitrogen) experimental site (http://www.biocon.umn.edu/) using a comprehensive functional gene array, GeoChip 3.0, which contains about 28,0000 probes and covers approximately 57,000 gene variants from 292 functional gene families involved in carbon, nitrogen, phosphorus and sulfur cycles as well as other functional processes. GeoChip data indicated that the functional structure of microbial communities was markedly different between ambient CO2 (aCO2) and eCO2 by detrended correspondence analysis (DCA) of all 5001 detected functional gene probes although no significant differences were detected in the overall microbial diversity. A further analysis of 1503 detected functional genes involved in C, N, P, and S cycles showed that a considerable portion (39percent) of them were only detected under either aCO2 (14percent) or eCO2 (25percent), indicating that the functional characteristics of the microbial community were significantly altered by eCO2. Also, for those shared genes (61percent) detected, some significantly (p<0.05) changed their abundance at eCO2. Especially, genes involved in labile C degradation, such as amyA, egl, and ara for starch, cellulose, and hemicelluloses, respectively, C fixation (e.g., rbcL, pcc/acc), N fixation (nifH), and phosphorus utilization (ppx) were significantly increased under eCO2, while those involved in decomposing recalcitrant C, such as glx, lip, and mnp for lignin degradation remained unchanged. This study provides insights into our understanding of belowground microbial communities and their feedbacks to terrestrial ecosystems at eCO2.

  3. Testing the growth rate hypothesis in vascular plants with above- and below-ground biomass.

    Science.gov (United States)

    Yu, Qiang; Wu, Honghui; He, Nianpeng; Lü, Xiaotao; Wang, Zhiping; Elser, James J; Wu, Jianguo; Han, Xingguo

    2012-01-01

    The growth rate hypothesis (GRH) proposes that higher growth rate (the rate of change in biomass per unit biomass, μ) is associated with higher P concentration and lower C:P and N:P ratios. However, the applicability of the GRH to vascular plants is not well-studied and few studies have been done on belowground biomass. Here we showed that, for aboveground, belowground and total biomass of three study species, μ was positively correlated with N:C under N limitation and positively correlated with P:C under P limitation. However, the N:P ratio was a unimodal function of μ, increasing for small values of μ, reaching a maximum, and then decreasing. The range of variations in μ was positively correlated with variation in C:N:P stoichiometry. Furthermore, μ and C:N:P ranges for aboveground biomass were negatively correlated with those for belowground. Our results confirm the well-known association of growth rate with tissue concentration of the limiting nutrient and provide empirical support for recent theoretical formulations.

  4. Testing the growth rate hypothesis in vascular plants with above- and below-ground biomass.

    Directory of Open Access Journals (Sweden)

    Qiang Yu

    Full Text Available The growth rate hypothesis (GRH proposes that higher growth rate (the rate of change in biomass per unit biomass, μ is associated with higher P concentration and lower C:P and N:P ratios. However, the applicability of the GRH to vascular plants is not well-studied and few studies have been done on belowground biomass. Here we showed that, for aboveground, belowground and total biomass of three study species, μ was positively correlated with N:C under N limitation and positively correlated with P:C under P limitation. However, the N:P ratio was a unimodal function of μ, increasing for small values of μ, reaching a maximum, and then decreasing. The range of variations in μ was positively correlated with variation in C:N:P stoichiometry. Furthermore, μ and C:N:P ranges for aboveground biomass were negatively correlated with those for belowground. Our results confirm the well-known association of growth rate with tissue concentration of the limiting nutrient and provide empirical support for recent theoretical formulations.

  5. Low below-ground organic carbon storage in a subarctic Alpine permafrost environment

    Science.gov (United States)

    Fuchs, M.; Kuhry, P.; Hugelius, G.

    2015-03-01

    This study investigates the soil organic carbon (SOC) storage in Tarfala Valley, northern Sweden. Field inventories, upscaled based on land cover, show that this alpine permafrost environment does not store large amounts of SOC, with an estimate mean of 0.9 ± 0.2 kg C m-2 for the upper meter of soil. This is 1 to 2 orders of magnitude lower than what has been reported for lowland permafrost terrain. The SOC storage varies for different land cover classes and ranges from 0.05 kg C m-2 for stone-dominated to 8.4 kg C m-2 for grass-dominated areas. No signs of organic matter burial through cryoturbation or slope processes were found, and radiocarbon-dated SOC is generally of recent origin (distribution in Tarfala Valley, based on the bottom temperature of snow measurements and a logistic regression model, showed that at an altitude where permafrost is probable the SOC storage is very low. In the high-altitude permafrost zones (above 1500 m), soils store only ca. 0.1 kg C m-2. Under future climate warming, an upward shift of vegetation zones may lead to a net ecosystem C uptake from increased biomass and soil development. As a consequence, alpine permafrost environments could act as a net carbon sink in the future, as there is no loss of older or deeper SOC from thawing permafrost.

  6. Above- and below-ground effects of plant diversity depend on species origin

    DEFF Research Database (Denmark)

    Kuebbing, Sara E.; Classen, Aimee Taylor; Sanders, Nate

    2015-01-01

    productivity: positive selection effect in nonnative communities and positive complementarity effect in native communities. Seedling establishment was 46% lower in nonnative than in native communities and was correlated with the average selection effect. Interspecific interactions contributed to productivity...... patterns, but the specific types of interactions differed between native and nonnative communities. These results reinforce findings that the diversity-productivity mechanisms in native and nonnative communities differ and are the first to show that these mechanisms can influence seedling establishment...

  7. Long-term resilience of above- and below ground ecosystem components among contrasting ecosystems.

    Science.gov (United States)

    Wardle, David A; Jonsson, Micael

    2014-07-01

    While several studies have explored how short-term ecological responses to disturbance vary among ecosystems, experimental studies of how contrasting ecosystems recover from disturbance in the longer term are few. We performed a simple long-term experiment on each of 30 contrasting forested islands in northern Sweden that vary in size; as size decreases, time since fire increases, soil fertility and ecosystem productivity declines, and plant species diversity increases. We predicted that resilience of understory plant community properties would be greatest on the larger, more productive islands, and that this would be paralleled by greater resilience of soil biotic and abiotic properties. For each island, we applied three disturbance treatments of increasing intensity to the forest understory once in 1998, i.e., light trimming, heavy trimming, and burning; a fourth treatment was an undisturbed control. We measured recovery of the understory vascular plant community annually over the following 14 years, and at that time also assessed recovery of mosses and several belowground variables. Consistent with our predictions, vascular plant whole-community variables (total cover, species richness, diversity [Shannon's H'], and community composition) recovered significantly more slowly on the smaller (least fertile) than the larger islands, but this difference was not substantial, and only noticeable in the most severely disturbed treatment. When an index of resilience was used, we were unable to detect effects of island size on the recovery of any property. We found that mosses and one shrub species (Empetrum hermaphroditum) recovered particularly slowly, and the higher abundance of this shrub on small islands was sufficient to explain any slower recovery of whole-ecosystem variables on those islands. Further, several belowground variables had not fully recovered from the most intense disturbance after 14 yr, and counter to our predictions, the degree of their recovery was never influenced by island size. While several studies have shown large variation among plant communities in their short-term response (notably resistance) to environmental perturbations, our results reveal that when perturbations are applied equally to highly contrasting ecosystems, differences in resilience among them in the longer term can be relatively minor, regardless of the severity of disturbance.

  8. Mechanosensitivity below Ground: Touch-Sensitive Smell-Producing Roots in the Shy Plant Mimosa pudica.

    Science.gov (United States)

    Musah, Rabi A; Lesiak, Ashton D; Maron, Max J; Cody, Robert B; Edwards, David; Fowble, Kristen L; Dane, A John; Long, Michael C

    2016-02-01

    The roots of the shy plant Mimosa pudica emit a cocktail of small organic and inorganic sulfur compounds and reactive intermediates into the environment, including SO2, methanesulfinic acid, pyruvic acid, lactic acid, ethanesulfinic acid, propanesulfenic acid, 2-aminothiophenol, S-propyl propane 1-thiosulfinate, phenothiazine, and thioformaldehyde, an elusive and highly unstable compound that, to our knowledge, has never before been reported to be emitted by a plant. When soil around the roots is dislodged or when seedling roots are touched, an odor is detected. The perceived odor corresponds to the emission of higher amounts of propanesulfenic acid, 2-aminothiophenol, S-propyl propane 1-thiosulfinate, and phenothiazine. The mechanosensitivity response is selective. Whereas touching the roots with soil or human skin resulted in odor detection, agitating the roots with other materials such as glass did not induce a similar response. Light and electron microscopy studies of the roots revealed the presence of microscopic sac-like root protuberances. Elemental analysis of these projections by energy-dispersive x-ray spectroscopy revealed them to contain higher levels of K(+) and Cl(-) compared with the surrounding tissue. Exposing the protuberances to stimuli that caused odor emission resulted in reductions in the levels of K(+) and Cl(-) in the touched area. The mechanistic implications of the variety of sulfur compounds observed vis-à-vis the pathways for their formation are discussed.

  9. Ectomycorrhizal communities above and below ground and truffle productivity in a Tuber aestivum orchard

    OpenAIRE

    Elena Salerni; Maria D'Aguanno; Pamela Leonardi; Claudia Perini

    2014-01-01

    Aim of study: The diversity of ectomycorrhizal fungal communities (EM) above (EMFb) and below (EMMt) ground associated with Quercus cerris L., Q. pubescens Willd., and Pinus nigra J.F.Arnold was analyzed.Area of study: A 20 year-old orchard that produces Tuber aestivum truffles, located a few kilometers from Chiusi della Verna (latitude 43° 41’ 53’’; longitude 11° 56’ 9’’) in Tuscany (central Italy) was observed.Material and Methods: This investigation combined analyses of EMFb, EMMt, T. aest...

  10. Completing below-ground carbon budgets for pastures, recovering forests, and mature forests of Amazonia

    Science.gov (United States)

    Davidson, Eric A.; Nepstad, Daniel C.; Trumbore, Susan E.

    1995-01-01

    This progress report covers the following efforts initiated for the year: year-round monthly soil CO2 flux measurements were started in both primary and secondary forests and in managed and degraded pastures; root sorting and weighing has begun and all four ecosystems at Paragominas have been analyzed through samples; regional modeling of soil water dynamics and minimum rooting depth has been done and the RADAMBRASIL soils database has been digitized and a 20 year record of the precipitation for the region has been produced, along with a hydrological ('bucket-tipping') model that will run within a GIS framework; prototype tension lysimeters have been designed and installed in soil pits to begin assessing the importance of DOC as a source of organic matter in deep soils; and many publications, listed in this document, have resulted from this year's research. Two of the papers published are included with this annual report document.

  11. Patterns and Processes of Vertebrate Evolution

    Science.gov (United States)

    Carroll, Robert Lynn

    1997-04-01

    This new text provides an integrated view of the forces that influence the patterns and rates of vertebrate evolution from the level of living populations and species to those that resulted in the origin of the major vertebrate groups. The evolutionary roles of behavior, development, continental drift, and mass extinctions are compared with the importance of variation and natural selection that were emphasized by Darwin. It is extensively illustrated, showing major transitions between fish and amphibians, dinosaurs and birds, and land mammals to whales. No book since Simpson's Major Features of Evolution has attempted such a broad study of the patterns and forces of evolutionary change. Undergraduate students taking a general or advanced course on evolution, and graduate students and professionals in evolutionary biology and paleontology will find the book of great interest.

  12. The Sarmatian vertebrates from Draxeni (Moldavian Platform

    Directory of Open Access Journals (Sweden)

    Vlad Codrea

    2007-10-01

    Full Text Available Middle Miocene (Sarmatian vertebrates had been unearthed at Draxeni (Vaslui district. The site is located in the northern area of the Moldavian Platform. There, the sand belonging to Şcheia Formation (Bessarabian is mined in a restricted open pit. This sand is related to a littoral environment (shoreface and foreshore. Some of its levels are rich in mollusc debris. Vertebrate remains, carried into the Bessarabian brackish basin are present too, but in smaller amounts. Mastodon, rhinoceros, hipparionine, tortoise remains had been collected there over several years. All teeth and bones are isolated and bear the marks of intensive rolling by waves and currents. This assemblage is typical for the top of Bessarabian in Moldavia, i.e. soon after the first hipparionine invasion in this part of the Europe. This assemblage can be related to the base of MN 9 unit.

  13. Aspergillus vertebral osteomyelitis in immunocompetent patients

    Directory of Open Access Journals (Sweden)

    Somika Sethi

    2012-01-01

    Full Text Available Fungal infections are one of the important cause of morbidity and mortality in immunocompromised patients. Aspergillus vertebral osteomyelitis is extremely rare. We report two cases of aspergillus vertebral osteomyelitis in immunocompetent men in the absence of an underlying disorder. The clinical and radiological findings were suggestive of Pott′s spine. The absolute CD4, CD8 counts and their ratio were normal. The HIV status was negative in both patients. Both patients underwent surgical decompression. The histopathology of tissue obtained were suggestive of aspergillus osteomyelitis. One patient had antifungal treatment for 3 months and was doing well at 1 year followup, whereas other patient did not turnup after 2 months.

  14. Brain size varies with temperature in vertebrates

    OpenAIRE

    2014-01-01

    The tremendous variation in brain size among vertebrates has long been thought to be related to differences in species’ metabolic rates. It is thought that species with higher metabolic rates can supply more energy to support the relatively high cost of brain tissue. And yet, while body temperature is known to be a major determinant of metabolic rate, the possible effects of temperature on brain size have scarcely been explored. Thus, here we explore the effects of temperature on brain size a...

  15. Transmission of ranavirus between ectothermic vertebrate hosts.

    Directory of Open Access Journals (Sweden)

    Roberto Brenes

    Full Text Available Transmission is an essential process that contributes to the survival of pathogens. Ranaviruses are known to infect different classes of lower vertebrates including amphibians, fishes and reptiles. Differences in the likelihood of infection among ectothermic vertebrate hosts could explain the successful yearlong persistence of ranaviruses in aquatic environments. The goal of this study was to determine if transmission of a Frog Virus 3 (FV3-like ranavirus was possible among three species from different ectothermic vertebrate classes: Cope's gray treefrog (Hyla chrysoscelis larvae, mosquito fish (Gambusia affinis, and red-eared slider (Trachemys scripta elegans. We housed individuals previously exposed to the FV3-like ranavirus with naïve (unexposed individuals in containers divided by plastic mesh screen to permit water flow between subjects. Our results showed that infected gray treefrog larvae were capable of transmitting ranavirus to naïve larval conspecifics and turtles (60% and 30% infection, respectively, but not to fish. Also, infected turtles and fish transmitted ranavirus to 50% and 10% of the naïve gray treefrog larvae, respectively. Nearly all infected amphibians experienced mortality, whereas infected turtles and fish did not die. Our results demonstrate that ranavirus can be transmitted through water among ectothermic vertebrate classes, which has not been reported previously. Moreover, fish and reptiles might serve as reservoirs for ranavirus given their ability to live with subclinical infections. Subclinical infections of ranavirus in fish and aquatic turtles could contribute to the pathogen's persistence, especially when highly susceptible hosts like amphibians are absent as a result of seasonal fluctuations in relative abundance.

  16. Light sensitivity in a vertebrate mechanoreceptor?

    Science.gov (United States)

    Baker, Gary E.; de Grip, Willem J.; Turton, Michael; Wagner, Hans-Joachim; Foster, Russell G.; Douglas, Ron H.

    2015-01-01

    ABSTRACT Using immunohistochemistry and western blot analysis, we demonstrate that melanopsin is localised in cells around the central pore of lateral line neuromasts in the African clawed frog, Xenopus laevis. Since melanopsin is a known photoreceptor pigment with diverse functions in vertebrates, we suggest that the lateral line of Xenopus laevis, which is primarily a mechanoreceptor, might also be light sensitive. Potential functions of such photosensitivity are discussed, including its role in mediating locomotor responses following dermal illumination. PMID:26206352

  17. The timing of Timezyme diversification in vertebrates.

    Science.gov (United States)

    Cazaméa-Catalan, Damien; Besseau, Laurence; Falcón, Jack; Magnanou, Elodie

    2014-01-01

    All biological functions in vertebrates are synchronized with daily and seasonal changes in the environment by the time keeping hormone melatonin. Its nocturnal surge is primarily due to the rhythmic activity of the arylalkylamine N-acetyl transferase AANAT, which thus became the focus of many investigations regarding its evolution and function. Various vertebrate isoforms have been reported from cartilaginous fish to mammals but their origin has not been clearly established. Using phylogeny and synteny, we took advantage of the increasing number of available genomes in order to test whether the various rounds of vertebrate whole genome duplications were responsible for the diversification of AANAT. We highlight a gene secondary loss of the AANAT2 in the Sarcopterygii, revealing for the first time that the AAANAT1/2 duplication occurred before the divergence between Actinopterygii (bony fish) and Sarcopterygii (tetrapods, lobe-finned fish, and lungfish). We hypothesize the teleost-specific whole genome duplication (WDG) generated the appearance of the AANAT1a/1b and the AANAT2/2'paralogs, the 2' isoform being rapidly lost in the teleost common ancestor (ray-finned fish). We also demonstrate the secondary loss of the AANAT1a in a Paracantopterygii (Atlantic cod) and of the 1b in some Ostariophysi (zebrafish and cave fish). Salmonids present an even more diverse set of AANATs that may be due to their specific WGD followed by secondary losses. We propose that vertebrate AANAT diversity resulted from 3 rounds of WGD followed by previously uncharacterized secondary losses. Extant isoforms show subfunctionalized localizations, enzyme activities and affinities that have increased with time since their emergence.

  18. [Cervical vertebral column--anatomy, fractures, treatment].

    Science.gov (United States)

    Kłosiński, Michał; Sienkiewicz-Zawilińska, Justyna; Lipski, Marcin; Zawiliński, Jarosław; Matyja, Andrzej; Walocha, Jerzy

    2009-01-01

    The paper deals with anatomy of human cervical spine. It shows close relation between knowledge on the normal structure and methods of treatment of different kinds of spine injuries. It describes detailed anatomy and mechanical features of cervical vertebral column, including the structure of distinct vertebrae, their joints and arrangement of muscles. It reviews also historical methods of treatment of fractures in this region considering current methods.

  19. The timing of Timezyme diversification in vertebrates.

    Directory of Open Access Journals (Sweden)

    Damien Cazaméa-Catalan

    Full Text Available All biological functions in vertebrates are synchronized with daily and seasonal changes in the environment by the time keeping hormone melatonin. Its nocturnal surge is primarily due to the rhythmic activity of the arylalkylamine N-acetyl transferase AANAT, which thus became the focus of many investigations regarding its evolution and function. Various vertebrate isoforms have been reported from cartilaginous fish to mammals but their origin has not been clearly established. Using phylogeny and synteny, we took advantage of the increasing number of available genomes in order to test whether the various rounds of vertebrate whole genome duplications were responsible for the diversification of AANAT. We highlight a gene secondary loss of the AANAT2 in the Sarcopterygii, revealing for the first time that the AAANAT1/2 duplication occurred before the divergence between Actinopterygii (bony fish and Sarcopterygii (tetrapods, lobe-finned fish, and lungfish. We hypothesize the teleost-specific whole genome duplication (WDG generated the appearance of the AANAT1a/1b and the AANAT2/2'paralogs, the 2' isoform being rapidly lost in the teleost common ancestor (ray-finned fish. We also demonstrate the secondary loss of the AANAT1a in a Paracantopterygii (Atlantic cod and of the 1b in some Ostariophysi (zebrafish and cave fish. Salmonids present an even more diverse set of AANATs that may be due to their specific WGD followed by secondary losses. We propose that vertebrate AANAT diversity resulted from 3 rounds of WGD followed by previously uncharacterized secondary losses. Extant isoforms show subfunctionalized localizations, enzyme activities and affinities that have increased with time since their emergence.

  20. Vertebral involvement in SAPHO syndrome: MRI findings

    Energy Technology Data Exchange (ETDEWEB)

    Nachtigal, A.; Cardinal, E.; Bureau, N.J. [Dept. of Radiology, Univ. de Montreal, QC (Canada); Sainte-Marie, L.G. [Dept. of Internal Medicine, Univ. de Montreal, QC (Canada); Milette, F. [Department of Pathology, Univ. de Montreal, QC (Canada)

    1999-03-01

    We report on the MRI findings in the vertebrae and surrounding soft tissues in two patients with the SAPHO syndrome (Synovitis, Acne, Pustulosis, Hyperostosis, Osteitis). The MRI findings include abnormal bone marrow signal, either focal or diffuse, of the vertebral bodies and posterior elements; hyperintense paravertebral soft tissue swelling and abnormal signal of the intervertebral discs. These changes are consistent with discitis and osteitis. (orig.) With 6 figs., 17 refs.

  1. The molecular biology of vertebrate olfaction.

    Science.gov (United States)

    Hayden, Sara; Teeling, Emma C

    2014-11-01

    The importance of chemosensation for vertebrates is reflected in the vast and variable nature of their chemosensory tissues, neurons, and genes, which we explore in this review. Immense progress has been made in elucidating the molecular biology of olfaction since the discovery of the olfactory receptor genes by Buck and Axel, which eventually won the authors the Nobel Prize. In particular, research linking odor ligands to olfactory receptors (ORs) is truly revolutionizing our understanding of how a large but limited number of chemosensory receptors can allow us to perceive the massive diversity of odors in our habitat. This research is providing insight into the evolution of genomes and providing the raw data needed to explore links between genotype and phenotype, still a grand challenge in biology. Research into olfaction is still developing and will no doubt continue until we have a clear understanding of how all odors are detected and the evolutionary forces that have molded the chemosensory subgenome in vertebrates. This knowledge will not only be a huge step in elucidating olfactory function, advancing scientific knowledge and techniques, but there are also commercial applications for this research. This review focuses on the molecular basis of chemosensation, particularly olfaction, its evolution across vertebrates and the recent molecular advances linking odors to their cognate receptors.

  2. Modular evolution of the Cetacean vertebral column.

    Science.gov (United States)

    Buchholtz, Emily A

    2007-01-01

    Modular theory predicts that hierarchical developmental processes generate hierarchical phenotypic units that are capable of independent modification. The vertebral column is an overtly modular structure, and its rapid phenotypic transformation in cetacean evolution provides a case study for modularity. Terrestrial mammals have five morphologically discrete vertebral series that are now known to be coincident with Hox gene expression patterns. Here, I present the hypothesis that in living Carnivora and Artiodactyla, and by inference in the terrestrial ancestors of whales, the series are themselves components of larger precaudal and caudal modular units. Column morphology in a series of fossil and living whales is used to predict the type and sequence of developmental changes responsible for modification of that ancestral pattern. Developmental innovations inferred include independent meristic additions to the precaudal column in basal archaeocetes and basilosaurids, stepwise homeotic reduction of the sacral series in protocetids, and dissociation of the caudal series into anterior tail and fluke subunits in basilosaurids. The most dramatic change was the novel association of lumbar and anterior caudal vertebrae in a module that crosses the precaudal/caudal boundary. This large unit is defined by shared patterns of vertebral morphology, count, and size in all living whales (Neoceti).

  3. Flapping wing aerodynamics: from insects to vertebrates.

    Science.gov (United States)

    Chin, Diana D; Lentink, David

    2016-04-01

    More than a million insects and approximately 11,000 vertebrates utilize flapping wings to fly. However, flapping flight has only been studied in a few of these species, so many challenges remain in understanding this form of locomotion. Five key aerodynamic mechanisms have been identified for insect flight. Among these is the leading edge vortex, which is a convergent solution to avoid stall for insects, bats and birds. The roles of the other mechanisms - added mass, clap and fling, rotational circulation and wing-wake interactions - have not yet been thoroughly studied in the context of vertebrate flight. Further challenges to understanding bat and bird flight are posed by the complex, dynamic wing morphologies of these species and the more turbulent airflow generated by their wings compared with that observed during insect flight. Nevertheless, three dimensionless numbers that combine key flow, morphological and kinematic parameters - the Reynolds number, Rossby number and advance ratio - govern flapping wing aerodynamics for both insects and vertebrates. These numbers can thus be used to organize an integrative framework for studying and comparing animal flapping flight. Here, we provide a roadmap for developing such a framework, highlighting the aerodynamic mechanisms that remain to be quantified and compared across species. Ultimately, incorporating complex flight maneuvers, environmental effects and developmental stages into this framework will also be essential to advancing our understanding of the biomechanics, movement ecology and evolution of animal flight.

  4. The immunoglobulins of cold-blooded vertebrates.

    Science.gov (United States)

    Pettinello, Rita; Dooley, Helen

    2014-11-24

    Although lymphocyte-like cells secreting somatically-recombining receptors have been identified in the jawless fishes (hagfish and lamprey), the cartilaginous fishes (sharks, skates, rays and chimaera) are the most phylogenetically distant group relative to mammals in which bona fide immunoglobulins (Igs) have been found. Studies of the antibodies and humoral immune responses of cartilaginous fishes and other cold-blooded vertebrates (bony fishes, amphibians and reptiles) are not only revealing information about the emergence and roles of the different Ig heavy and light chain isotypes, but also the evolution of specialised adaptive features such as isotype switching, somatic hypermutation and affinity maturation. It is becoming increasingly apparent that while the adaptive immune response in these vertebrate lineages arose a long time ago, it is most definitely not primitive and has evolved to become complex and sophisticated. This review will summarise what is currently known about the immunoglobulins of cold-blooded vertebrates and highlight the differences, and commonalities, between these and more "conventional" mammalian species.

  5. The Immunoglobulins of Cold-Blooded Vertebrates

    Directory of Open Access Journals (Sweden)

    Rita Pettinello

    2014-11-01

    Full Text Available Although lymphocyte-like cells secreting somatically-recombining receptors have been identified in the jawless fishes (hagfish and lamprey, the cartilaginous fishes (sharks, skates, rays and chimaera are the most phylogenetically distant group relative to mammals in which bona fide immunoglobulins (Igs have been found. Studies of the antibodies and humoral immune responses of cartilaginous fishes and other cold-blooded vertebrates (bony fishes, amphibians and reptiles are not only revealing information about the emergence and roles of the different Ig heavy and light chain isotypes, but also the evolution of specialised adaptive features such as isotype switching, somatic hypermutation and affinity maturation. It is becoming increasingly apparent that while the adaptive immune response in these vertebrate lineages arose a long time ago, it is most definitely not primitive and has evolved to become complex and sophisticated. This review will summarise what is currently known about the immunoglobulins of cold-blooded vertebrates and highlight the differences, and commonalities, between these and more “conventional” mammalian species.

  6. Horner syndrome due to vertebral artery stenosis.

    Science.gov (United States)

    Kim, Chul Han

    2013-11-01

    The author reports a rare case of Horner syndrome in a patient who resulted from stenosis of the vertebral artery after blunt trauma. A 31-year-old man was transferred to our department for evaluation of left medial orbital wall and nasal bone fractures. Five days ago, he was hospitalized due to multiple second to fourth rib fractures of the right chest following blunt trauma of the face, neck, and chest. Surgery was performed. Ten days later, he complained of drooping of the right eyelid. Physical examination revealed a discrete miosis and ptosis with normal levator function in the right eye. A workup for Horner syndrome was performed. Magnetic resonance angiography of the head and neck revealed a stenosis of the distal part of the right vertebral artery without the abnormality of carotid artery. He wore a cervical collar and underwent anticoagulation. However, Horner syndrome was not resolved over the next 12 months. Acute traumatic Horner syndrome may be associated with vertebral artery dissection in which the possibility of life-threatening injury can be masked.

  7. Percutaneous vertebral augmentation for painful osteolytic vertebral metastasis: a case report

    Directory of Open Access Journals (Sweden)

    Anselmetti GC

    2012-03-01

    Full Text Available Giovanni C Anselmetti1, Sean M Tutton2, Francis R Facchini3, Larry E Miller4,5, Jon E Block51Institute for Cancer Research and Treatment, Turin, Italy; 2Medical College of Wisconsin in Milwaukee, Froedtert Memorial Lutheran Hospital, Milwaukee, WI, USA; 3Interventional Radiology, Interventional Oncology, VIR Chicago, Hinsdale, IL, USA; 4Miller Scientific Consulting, Inc, Arden, NC, USA; 5The Jon Block Group, San Francisco, CA, USAIntroduction: Vertebral metastases are associated with significant pain, disability, and morbidity. Open surgery for fracture stabilization is often inappropriate in this population due to a poor risk-benefit profile, particularly if life expectancy is short. Percutaneous vertebroplasty and kyphoplasty are appealing adjunctive procedures in patients with malignancy for alleviation of intractable pain. However, these patients have higher risk of serious complications, notably cement extravasation. Described in this report is a case of a painful osteolytic vertebral metastasis that was successfully treated by a novel percutaneous vertebral augmentation system.Case presentation: A 42-year-old Caucasian female presented with a history of metastatic lung cancer unresponsive to radiation and chemotherapy with symptoms inadequately controlled by opiates over the previous 6 months. Magnetic resonance imaging and spiral computed tomography with two-dimensional reconstruction showed an osteolytic vertebral metastasis with complete involvement of the T10 vertebral body, extending to the cortical vertebral wall anteriorly and posteriorly. The patient was treated with percutaneous vertebral augmentation (Kiva® VCF Treatment System, Benvenue Medical, Inc, Santa Clara, CA utilizing a novel coil-shaped polyetheretherketone implant designed to minimize the risk of cement extravasation. After the minimally invasive procedure, bone cement distribution within the vertebral body was ideal, with no observed cement extravasation. No

  8. FRAX and the effect of teriparatide on vertebral and non-vertebral fracture

    Science.gov (United States)

    Harvey, Nicholas C; Kanis, John A; Odén, Anders; Burge, Russel T; Mitlak, Bruce H; Johansson, Helena; McCloskey, Eugene V

    2016-01-01

    Summary Daily teriparatide injections have been shown to reduce vertebral and non-vertebral fractures. Here we demonstrate that the magnitude of fracture risk reduction is independent of baseline fracture probability assessed by FRAX. Background Daily administration of 20μg or 40μg teriparatide has been shown to significantly decrease the risk of vertebral and non-vertebral fracture compared with placebo. The aim of the present study was to evaluate fracture risk assessed at baseline using the FRAX® tool and to determine the efficacy of teriparatide as a function of baseline fracture risk. Methods 1637 postmenopausal women in the pivotal phase 3 trial, randomly assigned to receive placebo (n=544), teriparatide 20 μg per day (n=541) or teriparatide 40 μg per day (n=552), were studied. Baseline clinical risk factors were entered into country-specific FRAX models to compute the 10-year probability of major osteoporotic fractures with or without input of femoral neck BMD. Because there was no difference in effect of 20 and 40μg teriparatide daily on fracture occurrence, the two active groups were merged. The interaction between probability of a major fracture and treatment efficacy was examined by Poisson regression. Results The 10-year probability of major osteoporotic fractures (with BMD) ranged from 2.2-67.2%. Treatment with teriparatide was associated with a 37% decrease in all non-vertebral fractures (95% CI:10-56 %) and a 56% decrease in low energy non-vertebral fractures (95% CI:24-75%) compared with placebo. The risk of morphometric vertebral fractures decreased significantly by 66% (95% CI:50-77%). Hazard ratios for the effect of teriparatide on the fracture outcome did not change significantly with increasing fracture probability (p>0.30). Similar findings were noted for the interaction when BMD was excluded from the FRAX model, or when probability of hip fracture was used as the marker of baseline risk. Conclusion We conclude that teriparatide

  9. Mucosal immunity in the gut: the non-vertebrate perspective.

    Science.gov (United States)

    Garcia-Garcia, Erick; Galindo-Villegas, Jorge; Mulero, Victor

    2013-01-01

    Much is now known about the vertebrate mechanisms involved in mucosal immunity, and the requirement of commensal microbiota at mucosal surfaces for the proper functioning of the immune system. In comparison, very little is known about the mechanisms of immunity at the barrier epithelia of non-vertebrate organisms. The purpose of this review is to summarize key experimental evidence illustrating how non-vertebrate immune mechanisms at barrier epithelia compare to those of higher vertebrates, using the gut as a model organ. Not only effector mechanisms of gut immunity are similar between vertebrates and non-vertebrates, but it also seems that the proper functioning of non-vertebrate gut defense mechanisms requires the presence of a resident microbiota. As more information becomes available, it will be possible to obtain a more accurate picture of how mucosal immunity has evolved, and how it adapts to the organisms' life styles.

  10. Turnabout Is Fair Play: Herbivory-Induced Plant Chitinases Excreted in Fall Armyworm Frass Suppress Herbivore Defenses in Maize.

    Science.gov (United States)

    Ray, Swayamjit; Alves, Patrick C M S; Ahmad, Imtiaz; Gaffoor, Iffa; Acevedo, Flor E; Peiffer, Michelle; Jin, Shan; Han, Yang; Shakeel, Samina; Felton, Gary W; Luthe, Dawn S

    2016-05-01

    The perception of herbivory by plants is known to be triggered by the deposition of insect-derived factors such as saliva and oral secretions, oviposition materials, and even feces. Such insect-derived materials harbor chemical cues that may elicit herbivore and/or pathogen-induced defenses in plants. Several insect-derived molecules that trigger herbivore-induced defenses in plants are known; however, insect-derived molecules suppressing them are largely unknown. In this study, we identified two plant chitinases from fall armyworm (Spodoptera frugiperda) larval frass that suppress herbivore defenses while simultaneously inducing pathogen defenses in maize (Zea mays). Fall armyworm larvae feed in enclosed whorls of maize plants, where frass accumulates over extended periods of time in close proximity to damaged leaf tissue. Our study shows that maize chitinases, Pr4 and Endochitinase A, are induced during herbivory and subsequently deposited on the host with the feces. These plant chitinases mediate the suppression of herbivore-induced defenses, thereby increasing the performance of the insect on the host. Pr4 and Endochitinase A also trigger the antagonistic pathogen defense pathway in maize and suppress fungal pathogen growth on maize leaves. Frass-induced suppression of herbivore defenses by deposition of the plant-derived chitinases Pr4 and Endochitinase A is a unique way an insect can co-opt the plant's defense proteins for its own benefit. It is also a phenomenon unlike the induction of herbivore defenses by insect oral secretions in most host-herbivore systems.

  11. Electrophysiological and behavioral responses of male fall webworm moths (Hyphantria cunea to Herbivory-induced mulberry (Morus alba leaf volatiles.

    Directory of Open Access Journals (Sweden)

    Rui Tang

    Full Text Available Volatile organic compounds (VOCs were collected from damaged and intact mulberry leaves (Morus alba L., Moraceae and from Hyphantria cunea larvae by headspace absorption with Super Q columns. We identified their constituents using gas chromatography-mass spectrometry, and evaluated the responses of male H. cunea antennae to the compounds using gas chromatography-flame ionization detection coupled with electroantennographic detection. Eleven VOC constituents were found to stimulate antennae of male H. cunea moths: β-ocimene, hexanal, cis-3-hexenal, limonene, trans-2-hexenal, cyclohexanone, cis-2-penten-1-ol, 6-methyl-5-hepten-2-one, 4-hydroxy-4-methyl-2-pentanone, trans-3-hexen-1-ol, and 2,4-dimethyl-3-pentanol. Nine of these chemicals were released by intact, mechanically-damaged, and herbivore-damaged leaves, while cis-2-penten-1-ol was released only by intact and mechanically-damaged leaves and β-ocimene was released only by herbivore-damaged leaves. Results from wind tunnel experiments conducted with volatile components indicated that male moths were significantly more attracted to herbivory-induced volatiles than the solvent control. Furthermore, male moths' attraction to a sex pheromone lure was increased by herbivory-induced compounds and β-ocimene, but reduced by cis-2-penten-1-ol. A proof long-range field trapping experiment showed that the efficiency of sex pheromone lures in trapping male moths was increased by β-ocimene and reduced by cis-2-penten-1-ol.

  12. Biodiversity as a multidimensional construct: a review, framework and case study of herbivory's impact on plant biodiversity.

    Science.gov (United States)

    Naeem, S; Prager, Case; Weeks, Brian; Varga, Alex; Flynn, Dan F B; Griffin, Kevin; Muscarella, Robert; Palmer, Matthew; Wood, Stephen; Schuster, William

    2016-12-14

    Biodiversity is inherently multidimensional, encompassing taxonomic, functional, phylogenetic, genetic, landscape and many other elements of variability of life on the Earth. However, this fundamental principle of multidimensionality is rarely applied in research aimed at understanding biodiversity's value to ecosystem functions and the services they provide. This oversight means that our current understanding of the ecological and environmental consequences of biodiversity loss is limited primarily to what unidimensional studies have revealed. To address this issue, we review the literature, develop a conceptual framework for multidimensional biodiversity research based on this review and provide a case study to explore the framework. Our case study specifically examines how herbivory by whitetail deer (Odocoileus virginianus) alters the multidimensional influence of biodiversity on understory plant cover at Black Rock Forest, New York. Using three biodiversity dimensions (taxonomic, functional and phylogenetic diversity) to explore our framework, we found that herbivory alters biodiversity's multidimensional influence on plant cover; an effect not observable through a unidimensional approach. Although our review, framework and case study illustrate the advantages of multidimensional over unidimensional approaches, they also illustrate the statistical and empirical challenges such work entails. Meeting these challenges, however, where data and resources permit, will be important if we are to better understand and manage the consequences we face as biodiversity continues to decline in the foreseeable future.

  13. Electrophysiological and behavioral responses of male fall webworm moths (Hyphantria cunea) to Herbivory-induced mulberry (Morus alba) leaf volatiles.

    Science.gov (United States)

    Tang, Rui; Zhang, Jin Ping; Zhang, Zhong Ning

    2012-01-01

    Volatile organic compounds (VOCs) were collected from damaged and intact mulberry leaves (Morus alba L., Moraceae) and from Hyphantria cunea larvae by headspace absorption with Super Q columns. We identified their constituents using gas chromatography-mass spectrometry, and evaluated the responses of male H. cunea antennae to the compounds using gas chromatography-flame ionization detection coupled with electroantennographic detection. Eleven VOC constituents were found to stimulate antennae of male H. cunea moths: β-ocimene, hexanal, cis-3-hexenal, limonene, trans-2-hexenal, cyclohexanone, cis-2-penten-1-ol, 6-methyl-5-hepten-2-one, 4-hydroxy-4-methyl-2-pentanone, trans-3-hexen-1-ol, and 2,4-dimethyl-3-pentanol. Nine of these chemicals were released by intact, mechanically-damaged, and herbivore-damaged leaves, while cis-2-penten-1-ol was released only by intact and mechanically-damaged leaves and β-ocimene was released only by herbivore-damaged leaves. Results from wind tunnel experiments conducted with volatile components indicated that male moths were significantly more attracted to herbivory-induced volatiles than the solvent control. Furthermore, male moths' attraction to a sex pheromone lure was increased by herbivory-induced compounds and β-ocimene, but reduced by cis-2-penten-1-ol. A proof long-range field trapping experiment showed that the efficiency of sex pheromone lures in trapping male moths was increased by β-ocimene and reduced by cis-2-penten-1-ol.

  14. Repeated vertebral augmentation for new vertebral compression fractures of postvertebral augmentation patients: a nationwide cohort study

    Directory of Open Access Journals (Sweden)

    Liang CL

    2015-03-01

    Full Text Available Cheng-Loong Liang,1 Hao-Kwan Wang,1 Fei-Kai Syu,2 Kuo-Wei Wang,1 Kang Lu,1 Po-Chou Liliang1 1Department of Neurosurgery, E-Da Hospital, I-Shou University, Kaohsiung City, Taiwan; 2Department of Pharmacy, China Medical University Hospital, Taichung City, Taiwan Purpose: Postvertebral augmentation vertebral compression fractures are common; repeated vertebral augmentation is usually performed for prompt pain relief. This study aimed to evaluate the incidence and risk factors of repeat vertebral augmentation.Methods: We performed a retrospective, nationwide, population-based longitudinal observation study, using the National Health Insurance Research Database (NHIRD of Taiwan. All patients who received vertebral augmentation for vertebral compression fractures were evaluated. The collected data included patient characteristics (demographics, comorbidities, and medication exposure and repeat vertebral augmentation. Kaplan–Meier and stratified Cox proportional hazard regressions were performed for analyses.Results: The overall incidence of repeat vertebral augmentation was 11.3% during the follow-up until 2010. Patients with the following characteristics were at greater risk for repeat vertebral augmentation: female sex (AOR=1.24; 95% confidence interval [CI]: 1.10–2.36, advanced age (AOR=1.60; 95% CI: 1.32–2.08, diabetes mellitus (AOR=4.31; 95% CI: 4.05–5.88, cerebrovascular disease (AOR=4.09; 95% CI: 3.44–5.76, dementia (AOR=1.97; 95% CI: 1.69–2.33, blindness or low vision (AOR=3.72; 95% CI: 2.32–3.95, hypertension (AOR=2.58; 95% CI: 2.35–3.47, and hyperlipidemia (AOR=2.09; 95% CI: 1.67–2.22. Patients taking calcium/ vitamin D (AOR=2.98; 95% CI: 1.83–3.93, bisphosphonates (AOR=2.11; 95% CI: 1.26–2.61, or calcitonin (AOR=4.59; 95% CI: 3.40–5.77 were less likely to undergo repeat vertebral augmentation; however, those taking steroids (AOR=7.28; 95% CI: 6.32–8.08, acetaminophen (AOR=3.54; 95% CI: 2.75–4.83, or nonsteroidal

  15. Clinical and neuroimaging features vertebral radiculopathy in the combination with vertebral hemangiomas

    Directory of Open Access Journals (Sweden)

    Che-honatskaya M.L.

    2012-06-01

    Full Text Available

    Aim of the study: to study the clinical and neuroimaging features of radiculopathy vertebral hemangiomas in conjunction with the vertebrae. Materials and methods. A total of 56 patients with radiculopathy vertebral hemangiomas combined with the vertebrae. Results. The patients in addition to pain, and focal neurological symptoms were observed violation of urination, and chronic venous insuffciency of lower extremities. MRI identifed three types of vertebral hem-angiomas, depending on the structural characteristics. Conclusion. The aim of the study is realized.Most hemangiomas are asymptomatic yourself. Pain and neurological symptoms caused by musculo-tonic component, the presence of disc herniation, changes in the intervertebral joints, ligaments violation. Type III meets the criteria for hemangiomas and requires aggressive surgical treatment.

  16. Modulación del crecimiento vertebral mediante electrocoagulación hemicircunferencial vertebral asistida

    OpenAIRE

    2009-01-01

    Nuestro trabajo está basado en la posibilidad de controlar el desarrollo asimétrico de los cartílagos de crecimiento vertebral, mediante la realización de una fisiodesis hemivertebral, con electrocoagulación, videoasistida por toracoscópica. Se realizará en cinco niveles torácicos, con un abordaje anterior mínimamente invasivo. Por lo tanto, planteamos como hipótesis de trabajo que La destrucción de las fisis de crecimiento vertebral mediante electrocoagulación, videoasistida por vía toracosc...

  17. Costs and Tradeoffs of Resistance and Tolerance to Belowground Herbivory in Potato

    Science.gov (United States)

    Díaz, Maria Fernanda; Bernal, Hugo; Ñustez, Carlos Eduardo; Thaler, Jennifer; Jander, Georg

    2017-01-01

    The success of sustainable crop production depends on our ability to select or create varieties that can allocate resources to both growth and defence. However, breeding efforts have emphasized increases in yields but have partially neglected defence traits against pests. Estimating the costs of multiple defences against tuber herbivores and the tradeoffs among them, as well as understanding the relationship between yield and multiple defences is still unknown but relevant to both basic and applied ecology. Using twenty commercial potato varieties available in Colombia and the tuber herbivore Tecia solanivora, we tested whether high yielding varieties show a reduction in three types of defence: constitutive and induced resistance, as well as tolerance. Specifically, we determined (1) the costs in terms of yield of all three defences, (2) the possible tradeoffs among them, and (3) if oviposition preference was related to the expression of these defences. We detected no costs in terms of yield of constitutive and induced resistance to tuber damage. We did, however, find evidence of costs of being able to tolerate tuber herbivory. While we found no tradeoffs among any of the estimated defences, there was a positive correlation between aboveground compensatory growth and tolerance in terms of tuber production, suggesting that after damage there are no shifts in the allocation of resources from aboveground to belowground biomass. Finally, we found that females laid more eggs on those varieties with the lowest level of constitutive resistance. In conclusion our findings suggest that in potatoes, breeding for higher yields has not caused any reduction in constitutive or induced resistance to tuber damage. This is not the case for tolerance where those varieties with higher yields are also less likely to tolerate tuber damage. Given the high incidence of tuber pests in Colombia, selecting for higher tolerance could allow for high productivity in the presence of herbivores

  18. Aspen Ecology in Rocky Mountain National Park: Age Distribution, Genetics, and the Effects of Elk Herbivory

    Science.gov (United States)

    Zeigenfuss, Linda C.; Binkley, Dan; Tuskan, Gerald A.; Romme, William H.; Yin, Tongming; DiFazio, Stephen; Singer, Francis J.

    2008-01-01

    very intense herbivory by elk and harsh environmental conditions. Conservation efforts through fencing protection and decreased elk browsing pressure are already being planned as part of the park's new elk management plan. If these efforts are undertaken, conditions that encourage stem recruitment to the tree canopy will likely result and the continued survival of these aspen stands will be enhanced.

  19. Herbivory of sympatric elk and cattle on Lincoln National Forest, south-central New Mexico

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    Heather H. Halbritter

    2015-09-01

    Full Text Available Background Wildlife and livestock grazing are important products of forest ecosystems, but can be controversial. Herbivory by North American elk and domestic cattle is a contentious management issue throughout western North America, often driving management proposals to decrease cattle and elk numbers based on perceived overutilization of forages. Such observations are often site level rather than landscape, and may confuse ecological sustainability with desired conditions. Methods We used line transects to document vegetation composition, structure, and grazing and browsing utilization for 4 key habitat types: mountain meadows, aspen, thinned conifer, and burned conifer on Lincoln National Forest, New Mexico, USA. We documented relative habitat use of these types by elk, mule deer, and cattle and modeled relative use on residual grass biomass of mountain meadows and browse utilization of forested types. We determined diets and diet quality of elk and cattle to assess degree of competition. Results Use of grasses in meadows was below management thresholds, and combined elk, cattle, and deer relative habitat use accounted for < 14 % of the variance in residual stubble height of Poa pratensis, the most abundant grass. Palatable browse was limited in habitat types (< 107 stems·ha -1 , use was generally high, and elk presence was correlated with the majority of browsing. Elk and cattle diets did not significantly overlap (Schoener’s index 0.54–0.57; elk fed primarily on deciduous shrubs (34 %–55 % of annual diets and cattle on grass (72 %–77 %. Digestibility and crude protein levels of cattle diets and body condition of elk indicated high quality diets for cattle and marginal–good quality diets for elk. Conclusions At observed stocking levels and densities, cattle and elk were not competing for forage based on diet similarity, nor were key habitat types being used beyond sustainable levels. Low browse availability indicates that

  20. Assisted techniques for vertebral cementoplasty: Why should we do it?

    Energy Technology Data Exchange (ETDEWEB)

    Muto, M., E-mail: mutomar@tiscali.it [Department of Diagnostic Imaging, Section of Neuroradiology—“A. Cardarelli” Hospital, Naples (Italy); Marcia, S. [Section of Radiology—Santissima Trinità Hospital, Cagliari (Italy); Guarnieri, G. [Department of Diagnostic Imaging, Section of Neuroradiology—“A. Cardarelli” Hospital, Naples (Italy); Pereira, V. [Unit of Interventional Neuroradiology–HUG, Geneva (Switzerland)

    2015-05-15

    Assisted techniques (AT) for vertebral cementoplasty include multiple mini-invasive percutaneous systems in which vertebral augmentation is obtained through mechanical devices with the aim to reach the best vertebral height restoration. As an evolution of the vertebroplasty, the rationale of the AT-treatment is to combine the analgesic and stability effect of cement injection with the restoration of a physiological height for the collapsed vertebral body. Reduction of the vertebral body kyphotic deformity, considering the target of normal spine biomechanics, could improve all systemic potential complications evident in patient with vertebral compression fracture (VCF). Main indications for AT are related to fractures in fragile vertebral osseous matrix and non-osteoporotic vertebral lesions due to spine metastasis or trauma. Many companies developed different systems for AT having the same target but different working cannula, different vertebral height restoration system and costs. Aim of this review is to discuss about vertebral cementoplasty procedures and techniques, considering patient inclusion and exclusion criteria as well as all related minor and/or major interventional complications.

  1. Herbivory and habitat association of tree seedlings in lowland evergreen rainforest on white-sand and terra-firme in the upper Rio Negro

    NARCIS (Netherlands)

    Stropp, J.; van der Sleen, Peter; Quesada, C.A.; ter Steege, Hans

    2014-01-01

    Background: It has been proposed that the interaction between herbivory and soil nutrient availability drives habitat association of tree species in Peruvian Amazonia. Nevertheless, there is no empirical evidence that this interaction holds across other Amazonian regions. Aims: We address this knowl

  2. Formation of the unusual semivolatile Diterpene Rhizathalene by the Arabidopsis Class I Terpene Synthase TPS08 in the root stele is involved in defense against belowground herbivory

    Science.gov (United States)

    Secondary metabolites are major constituents of plant defense against herbivore attack. Relatively little is known about the cell type-specific formation and anti-herbivore activities of secondary compounds in roots despite the substantial impact of root herbivory on plant performance and fitness. ...

  3. Vegetation succession and herbivory in a salt marsh: changes induced by sea level rise and silt deposition along an elevational gradient

    NARCIS (Netherlands)

    Olff, H.; De Leeuw, J.; Bakker, J.P.; Platerink, R.J.; Van Wijnen, H.J.; De Munck, W.

    1997-01-01

    1 The relationships between soil development, vertical vegetation zonation, vegetation succession and herbivory by Brent geese, Branta bernicla, were studied in a coastal salt marsh. We were able to analyse up to 100 years of salt marsh development by comparing sites where vegetation succession had

  4. Vegetation succession and herbivory in a salt marsh : changes induced by sea level rise and silt deposition along an elevational gradient

    NARCIS (Netherlands)

    Olff, H; De Leeuw, J; Bakker, JP; Platerink, RJ; Van Wijnen, HJ; De Munck, W

    1997-01-01

    1 The relationships between soil development, vertical vegetation zonation, vegetation succession and herbivory by Brent geese, Branta bernicla, were studied in a coastal salt marsh. We were able to analyse up to 100 years of salt marsh development by comparing sites where vegetation succession had

  5. A standard system to study vertebrate embryos.

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    Ingmar Werneburg

    Full Text Available Staged embryonic series are important as reference for different kinds of biological studies. I summarise problems that occur when using 'staging tables' of 'model organisms'. Investigations of developmental processes in a broad scope of taxa are becoming commonplace. Beginning in the 1990s, methods were developed to quantify and analyse developmental events in a phylogenetic framework. The algorithms associated with these methods are still under development, mainly due to difficulties of using non-independent characters. Nevertheless, the principle of comparing clearly defined newly occurring morphological features in development (events in quantifying analyses was a key innovation for comparative embryonic research. Up to date no standard was set for how to define such events in a comparative approach. As a case study I compared the external development of 23 land vertebrate species with a focus on turtles, mainly based on reference staging tables. I excluded all the characters that are only identical for a particular species or general features that were only analysed in a few species. Based on these comparisons I defined 104 developmental characters that are common either for all vertebrates (61 characters, gnathostomes (26, tetrapods (3, amniotes (7, or only for sauropsids (7. Characters concern the neural tube, somite, ear, eye, limb, maxillary and mandibular process, pharyngeal arch, eyelid or carapace development. I present an illustrated guide listing all the defined events. This guide can be used for describing developmental series of any vertebrate species or for documenting specimen variability of a particular species. The guide incorporates drawings and photographs as well as consideration of species identifying developmental features such as colouration. The simple character-code of the guide is extendable to further characters pertaining to external and internal morphological, physiological, genetic or molecular development, and

  6. Limbus lumbar and sacral vertebral fractures.

    Science.gov (United States)

    Mendez, Jorge S; Huete, Isidro L; Tagle, Patricio M

    2002-03-01

    We evaluated the fractures of the lumbar and sacral vertebral limbus by disc impingement at the peripheral ring apophysis in 23 adults associated with trauma in 16 of them. Lumbalgia, radicular pain and narrow canal symptoms are the presenting forms of this underdiagnosed pathology. CT is the best method of examination, while plain roentgenograms and MR are usually negative. Accurate diagnosis and surgical technique with larger exposure are needed to resect the fractured fragments and protruded disc material for decompressing the roots and the dural sac. Our results were very good on the majority of cases.

  7. Planar cell polarity and vertebrate organogenesis.

    Science.gov (United States)

    Karner, Courtney; Wharton, Keith A; Carroll, Thomas J

    2006-04-01

    In addition to being polarized along their apical/basal axis, cells composing most (if not all) organs are also polarized in a plane vertical to the A/B axis. Recent studies indicate that this so-called planar cell polarity (PCP) plays an essential role in the formation of multiple organ systems regulating directed cell migrations, polarized cell division and proper differentiation. In this review we will discuss the molecular mechanisms regulating PCP, including the hypothesized roles for Wnt ligands in this process, and its roles in vertebrate organogenesis.

  8. A Classification System for the Spread of Polymethyl Methacrylate in Vertebral Bodies Treated with Vertebral Augmentation

    Science.gov (United States)

    Frankl, Joseph; Sakata, Michael P.; Choudhary, Gagandeep; Hur, Seung; Peterson, Andrew; Hennemeyer, Charles T.

    2016-01-01

    In this study, we develop a classification system for describing polymethyl methacrylate (PMMA) spread in vertebral bodies after kyphoplasty or vertebroplasty for vertebral compression fractures (VCFs) and for assessing whether PMMA spread varies between operators, VCF etiology, or vertebral level. Intraoperative fluoroscopic images of 198 vertebral levels were reviewed in 137 patients (women, 84; men, 53; mean age, 75.8 ± 12.5; and those with a diagnosis of osteoporosis, 63%) treated with kyphoplasty between January 01, 2015 and May 31, 2015 at a single center to create a 5-class descriptive system. PMMA spread patterns in the same images were then classified by 2 board-certified radiologists, and a third board-certified radiologist resolved conflicts. A total of 2 primary PMMA spread patterns were identified, namely, acinar and globular, with subtypes of localized acinar, diffuse globular, and mixed, to describe an equal combination of patterns. Interrater reliability using the system was moderate (κ = 0.47). After resolving conflicts, the most common spread class was globular (n = 63), followed by mixed (n = 58), diffuse globular (n = 30), acinar (n = 27), and localized acinar (n = 20). The spread class after treatment by the 2 most frequent operators differed significantly (n1 = 63, n2 = 70; P kyphoplasty and vertebroplasty efficacy and adverse events. PMID:27795998

  9. Endplates Changes Related to Age and Vertebral Segment

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    Carlos Fernando P. S. Herrero

    2014-01-01

    Full Text Available Endplate separations are defined as the presence of a space between the hyaline cartilage and the cortical bone of the adjacent vertebral body. This study evaluates endplate separations from the vertebral body and intervertebral discs and verifies if endplate separation is related to age and the spinal level. Groups were formed based on age (20–40 and 41–85 years old and the vertebral segment (T7-T8 and L4-L5 segments. Histological analysis included assessment of the length of the vertebral endplates, the number and dimensions of the separations, and orientation of the collagen fibers, in the mid-sagittal slice. Two indexes were created: the separation index (number of separations/vertebral length and separation extension index (sum of all separations/vertebral length. The results of the study demonstrated a direct relationship between the density of separations in the endplate and two variables: age and spinal level.

  10. Two forms of adaptive immunity in vertebrates: similarities and differences.

    Science.gov (United States)

    Kasahara, Masanori; Sutoh, Yoichi

    2014-01-01

    Unlike jawed vertebrates that use T-cell and B-cell receptors for antigen recognition, jawless vertebrates represented by lampreys and hagfish use variable lymphocyte receptors (VLRs) as antigen receptors. VLRs generate diversity comparable to that of gnathostome antigen receptors by assembling variable leucine-rich repeat modules. The discovery of VLR has revolutionized our understanding of how adaptive immunity emerged and highlighted the differences between the adaptive immune systems (AISs) of jawed and jawless vertebrates. However, emerging evidence also indicates that their AISs have much in common. Particularly striking is the conservation of lymphocyte lineages. The basic architecture of the AIS including the dichotomy of lymphocytes appears to have been established in a common ancestor of jawed and jawless vertebrates. We review here the current knowledge on the AIS of jawless vertebrates, emphasizing both the similarities to and differences from the AIS of jawed vertebrates.

  11. Identifying Synonymous Regulatory Elements in Vertebrate Genomes

    Energy Technology Data Exchange (ETDEWEB)

    Ovcharenko, I; Nobrega, M A

    2005-02-07

    Synonymous gene regulation, defined as driving shared temporal and/or spatial expression of groups of genes, is likely predicated on genomic elements that contain similar modules of certain transcription factor binding sites (TFBS). We have developed a method to scan vertebrate genomes for evolutionary conserved modules of TFBS in a predefined configuration, and created a tool, named SynoR that identify synonymous regulatory elements (SREs) in vertebrate genomes. SynoR performs de novo identification of SREs utilizing known patterns of TFBS in active regulatory elements (REs) as seeds for genome scans. Layers of multiple-species conservation allow the use of differential phylogenetic sequence conservation filters in the search of SREs and the results are displayed as to provide an extensive annotation of genes containing detected REs. Gene Ontology categories are utilized to further functionally classify the identified genes, and integrated GNF Expression Atlas 2 data allow the cataloging of tissue-specificities of the predicted SREs. We illustrate how this new tool can be used to establish a linkage between human diseases and noncoding genomic content. SynoR is publicly available at http://synor.dcode.org.

  12. Sensing and surviving hypoxia in vertebrates.

    Science.gov (United States)

    Jonz, Michael G; Buck, Leslie T; Perry, Steve F; Schwerte, Thorsten; Zaccone, Giacomo

    2016-02-01

    Surviving hypoxia is one of the most critical challenges faced by vertebrates. Most species have adapted to changing levels of oxygen in their environment with specialized organs that sense hypoxia, while only few have been uniquely adapted to survive prolonged periods of anoxia. The goal of this review is to present the most recent research on oxygen sensing, adaptation to hypoxia, and mechanisms of anoxia tolerance in nonmammalian vertebrates. We discuss the respiratory structures in fish, including the skin, gills, and air-breathing organs, and recent evidence for chemosensory neuroepithelial cells (NECs) in these tissues that initiate reflex responses to hypoxia. The use of the zebrafish as a genetic and developmental model has allowed observation of the ontogenesis of respiratory and chemosensory systems, demonstration of a putative intracellular O2 sensor in chemoreceptors that may initiate transduction of the hypoxia signal, and investigation into the effects of extreme hypoxia on cardiorespiratory development. Other organisms, such as goldfish and freshwater turtles, display a high degree of anoxia tolerance, and these models are revealing important adaptations at the cellular level, such as the regulation of glutamatergic and GABAergic neurotransmission in defense of homeostasis in central neurons.

  13. A membrane-bound vertebrate globin.

    Directory of Open Access Journals (Sweden)

    Miriam Blank

    Full Text Available The family of vertebrate globins includes hemoglobin, myoglobin, and other O(2-binding proteins of yet unclear functions. Among these, globin X is restricted to fish and amphibians. Zebrafish (Danio rerio globin X is expressed at low levels in neurons of the central nervous system and appears to be associated with the sensory system. The protein harbors a unique N-terminal extension with putative N-myristoylation and S-palmitoylation sites, suggesting membrane-association. Intracellular localization and transport of globin X was studied in 3T3 cells employing green fluorescence protein fusion constructs. Both myristoylation and palmitoylation sites are required for correct targeting and membrane localization of globin X. To the best of our knowledge, this is the first time that a vertebrate globin has been identified as component of the cell membrane. Globin X has a hexacoordinate binding scheme and displays cooperative O(2 binding with a variable affinity (P(50∼1.3-12.5 torr, depending on buffer conditions. A respiratory function of globin X is unlikely, but analogous to some prokaryotic membrane-globins it may either protect the lipids in cell membrane from oxidation or may act as a redox-sensing or signaling protein.

  14. Evolution of vertebrate interferon inducible transmembrane proteins

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    Hickford Danielle

    2012-04-01

    Full Text Available Abstract Background Interferon inducible transmembrane proteins (IFITMs have diverse roles, including the control of cell proliferation, promotion of homotypic cell adhesion, protection against viral infection, promotion of bone matrix maturation and mineralisation, and mediating germ cell development. Most IFITMs have been well characterised in human and mouse but little published data exists for other animals. This study characterised IFITMs in two distantly related marsupial species, the Australian tammar wallaby and the South American grey short-tailed opossum, and analysed the phylogeny of the IFITM family in vertebrates. Results Five IFITM paralogues were identified in both the tammar and opossum. As in eutherians, most marsupial IFITM genes exist within a cluster, contain two exons and encode proteins with two transmembrane domains. Only two IFITM genes, IFITM5 and IFITM10, have orthologues in both marsupials and eutherians. IFITM5 arose in bony fish and IFITM10 in tetrapods. The bone-specific expression of IFITM5 appears to be restricted to therian mammals, suggesting that its specialised role in bone production is a recent adaptation specific to mammals. IFITM10 is the most highly conserved IFITM, sharing at least 85% amino acid identity between birds, reptiles and mammals and suggesting an important role for this presently uncharacterised protein. Conclusions Like eutherians, marsupials also have multiple IFITM genes that exist in a gene cluster. The differing expression patterns for many of the paralogues, together with poor sequence conservation between species, suggests that IFITM genes have acquired many different roles during vertebrate evolution.

  15. Tandemly Arrayed Genes in Vertebrate Genomes

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    Deng Pan

    2008-01-01

    Full Text Available Tandemly arrayed genes (TAGs are duplicated genes that are linked as neighbors on a chromosome, many of which have important physiological and biochemical functions. Here we performed a survey of these genes in 11 available vertebrate genomes. TAGs account for an average of about 14% of all genes in these vertebrate genomes, and about 25% of all duplications. The majority of TAGs (72–94% have parallel transcription orientation (i.e., they are encoded on the same strand in contrast to the genome, which has about 50% of its genes in parallel transcription orientation. The majority of tandem arrays have only two members. In all species, the proportion of genes that belong to TAGs tends to be higher in large gene families than in small ones; together with our recent finding that tandem duplication played a more important role than retroposition in large families, this fact suggests that among all types of duplication mechanisms, tandem duplication is the predominant mechanism of duplication, especially in large families. Finally, several species have a higher proportion of large tandem arrays that are species-specific than random expectation.

  16. "Ostrich sign" indicates bilateral vertebral artery dissection.

    Science.gov (United States)

    Rose, David Z; Husain, M Rizwan

    2012-11-01

    Vertebral artery dissections (VADs) comprise about 2% of ischemic strokes and can be associated with trauma, chiropractic manipulation, motor vehicle collisions, whiplash, amusement park rides, golfing, and other motion-induced injuries to the neck. We present a case of bilateral extracranial VAD as a complication of conducting an orchestra. To our knowledge, this has not been documented in the literature. Conceivably, vigorous neck twisting in an inexperienced, amateur conductor may place excessive rotational forces upon mobile portions of the verterbral arteries, tear the intima, deposit subintimal blood that extends longitudinally, and cause neck pain and/or posterior fossa ischemic symptoms. Magnetic resonance angiography examinations of axially oriented slices of bilateral VADs resemble the face of an ostrich. This observation is similar to the "puppy sign," in which bilateral internal carotid artery dissections resemble the face of a dog. Craniocervical dissections of either the carotid or vertebral arteries have the potential to form an aneurysm, cause artery-to-artery embolism, or completely occlude the parent artery, resulting in an ischemic stroke. Because bilateral VADs in axial magnetic resonance angiographic sections stand out like the eyes of an ostrich, and because the fast identification of VADs is so critical, we eponymize this image the "ostrich sign."

  17. Lumbo-costo-vertebral syndrome with posterior spinal dysraphism.

    Science.gov (United States)

    Kumar, G Samson Sujit; Kulkarni, Vaijayantee; Haran, R P

    2005-09-01

    Lumbo-costo-vertebral syndrome, which includes abnormalities of the vertebral bodies, ribs and trunk musculature, is very rare and only few cases have been reported. We report a case of 18-month-old female child with absent ribs, hemivertebrae, superior lumbar hernia (features of lumbo-costo-vertebral syndrome) and posterior spinal dysraphism, which to our knowledge is the first case in the English literature with such a combination of defects. Embryology and management of the case is discussed.

  18. Aberrant vertebral artery originating from the descending aorta

    Energy Technology Data Exchange (ETDEWEB)

    Stoesslein, F.; Porstmann, W.; Schueler, F.; Schoepke, W.

    1982-05-01

    A so far unknown case of a combination of coarctation and a right vertebral artery originating isolatedly from the thoracic aorta is reported, presenting the embryological hypothesis of the development of this anomalous course. The haemodynamic action of the coarctation produces a steal effect so that the vascular segments existing cranially of the stenosis are connected with the poststenotic zone via the vertebral circulation and the anomalous right vertebral artery.

  19. Candidal Vertebral Osteomyelitis in the Midst of Renal Disorders

    Science.gov (United States)

    Kumar, Anil; Rao, Srivatsa Nagaraja; Kumar, Krishna; Karim, Shamsul

    2016-01-01

    Vertebral osteomyelitis also known as discitis/pyogenic spondylitis refers to inflammation of the vertebral disc space. It is commonly seen in men and adults more than 50 years of age. Fungal osteomyelitis is a rare scenario compared to its bacterial counterpart. Spinal epidural abscess is a dangerous complication associated with vertebral osteomyelitis. Here, we report two cases of vertebral osteomyelitis caused by Candida tropicalis in patients with renal disorders (stage 5 chronic kidney disease and nephropathy). One of the case discussed here presented with spinal epidural abscess. Both the patients were started on antifungal therapy. One patient responded to treatment while the other was lost to follow up. PMID:27190806

  20. Facts and fancies about early fossil chordates and vertebrates.

    Science.gov (United States)

    Janvier, Philippe

    2015-04-23

    The interrelationships between major living vertebrate, and even chordate, groups are now reasonably well resolved thanks to a large amount of generally congruent data derived from molecular sequences, anatomy and physiology. But fossils provide unexpected combinations of characters that help us to understand how the anatomy of modern groups was progressively shaped over millions of years. The dawn of vertebrates is documented by fossils that are preserved as either soft-tissue imprints, or minute skeletal fragments, and it is sometimes difficult for palaeontologists to tell which of them are reliable vertebrate remains and which merely reflect our idea of an ancestral vertebrate.

  1. Reintroduction of locally extinct vertebrates impacts arid soil fungal communities.

    Science.gov (United States)

    Clarke, Laurence J; Weyrich, Laura S; Cooper, Alan

    2015-06-01

    Introduced species have contributed to extinction of native vertebrates in many parts of the world. Changes to vertebrate assemblages are also likely to alter microbial communities through coextinction of some taxa and the introduction of others. Many attempts to restore degraded habitats involve removal of exotic vertebrates (livestock and feral animals) and reintroduction of locally extinct species, but the impact of such reintroductions on microbial communities is largely unknown. We used high-throughput DNA sequencing of the fungal internal transcribed spacer I (ITS1) region to examine whether replacing exotic vertebrates with reintroduced native vertebrates led to changes in soil fungal communities at a reserve in arid central Australia. Soil fungal diversity was significantly different between dune and swale (interdune) habitats. Fungal communities also differed significantly between sites with exotic or reintroduced native vertebrates after controlling for the effect of habitat. Several fungal operational taxonomic units (OTUs) found exclusively inside the reserve were present in scats from reintroduced native vertebrates, providing a direct link between the vertebrate assemblage and soil microbial communities. Our results show that changes to vertebrate assemblages through local extinctions and the invasion of exotic species can alter soil fungal communities. If local extinction of one or several species results in the coextinction of microbial taxa, the full complement of ecological interactions may never be restored.

  2. Osteoporotic vertebral fracture simulating a spinal tumor: a case report

    Directory of Open Access Journals (Sweden)

    Moscote-Salazar Luis Rafael

    2015-06-01

    Full Text Available Vertebral fractures are a frequent entity, mainly in the thoracolumbar and lumbar spine. In some circumstances the differential diagnosis of vertebral injuries can confuse the physician, since the difference between an osteoporotic vertebral fracture and a fracture secondary to a tumor is not clear. We report the case of a patient with osteoporotic vertebral fracture simulating a spinal tumor, handled by our department of neurosurgery as illustrative experience to guide the approach in those cases, in which the definitive diagnosis is crucial for therapeutic decision making

  3. Genome duplication in early vertebrates: insights from agnathan cytogenetics.

    Science.gov (United States)

    Caputo Barucchi, V; Giovannotti, M; Nisi Cerioni, P; Splendiani, A

    2013-01-01

    Agnathans represent a remnant of a primitive offshoot of the vertebrates, and the long evolutionary separation between their 2 living groups, namely hagfishes and lampreys, could explain profound biological differences, also in karyotypes and genome sizes. Here, cytogenetic studies available on these vertebrates were summarized and data discussed with reference to the recently demonstrated monophyly of this group and to the 2 events of whole genome duplication (1R and 2R) characterizing the evolution of vertebrates. The comparison of cytogenetic data and phylogenetic relationships among agnathans and gnathostomes seems to support the hypothesis that 1R and 2R occurred before the evolutionary divergence between jawless and jawed vertebrates.

  4. Control of Vertebrate Skeletal Mineralization by Polyphosphates

    Science.gov (United States)

    Omelon, Sidney; Georgiou, John; Henneman, Zachary J.; Wise, Lisa M.; Sukhu, Balram; Hunt, Tanya; Wynnyckyj, Chrystia; Holmyard, Douglas; Bielecki, Ryszard; Grynpas, Marc D.

    2009-01-01

    Background Skeletons are formed in a wide variety of shapes, sizes, and compositions of organic and mineral components. Many invertebrate skeletons are constructed from carbonate or silicate minerals, whereas vertebrate skeletons are instead composed of a calcium phosphate mineral known as apatite. No one yet knows why the dynamic vertebrate skeleton, which is continually rebuilt, repaired, and resorbed during growth and normal remodeling, is composed of apatite. Nor is the control of bone and calcifying cartilage mineralization well understood, though it is thought to be associated with phosphate-cleaving proteins. Researchers have assumed that skeletal mineralization is also associated with non-crystalline, calcium- and phosphate-containing electron-dense granules that have been detected in vertebrate skeletal tissue prepared under non-aqueous conditions. Again, however, the role of these granules remains poorly understood. Here, we review bone and growth plate mineralization before showing that polymers of phosphate ions (polyphosphates: (PO3−)n) are co-located with mineralizing cartilage and resorbing bone. We propose that the electron-dense granules contain polyphosphates, and explain how these polyphosphates may play an important role in apatite biomineralization. Principal Findings/Methodology The enzymatic formation (condensation) and destruction (hydrolytic degradation) of polyphosphates offers a simple mechanism for enzymatic control of phosphate accumulation and the relative saturation of apatite. Under circumstances in which apatite mineral formation is undesirable, such as within cartilage tissue or during bone resorption, the production of polyphosphates reduces the free orthophosphate (PO43−) concentration while permitting the accumulation of a high total PO43− concentration. Sequestering calcium into amorphous calcium polyphosphate complexes can reduce the concentration of free calcium. The resulting reduction of both free PO43− and free

  5. Imperfect isolation: factors and filters shaping Madagascar's extant vertebrate fauna.

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    Karen E Samonds

    Full Text Available Analyses of phylogenetic topology and estimates of divergence timing have facilitated a reconstruction of Madagascar's colonization events by vertebrate animals, but that information alone does not reveal the major factors shaping the island's biogeographic history. Here, we examine profiles of Malagasy vertebrate clades through time within the context of the island's paleogeographical evolution to determine how particular events influenced the arrival of the island's extant groups. First we compare vertebrate profiles on Madagascar before and after selected events; then we compare tetrapod profiles on Madagascar to contemporary tetrapod compositions globally. We show that changes from the Mesozoic to the Cenozoic in the proportions of Madagascar's tetrapod clades (particularly its increase in the representation of birds and mammals are tied to changes in their relative proportions elsewhere on the globe. Differences in the representation of vertebrate classes from the Mesozoic to the Cenozoic reflect the effects of extinction (i.e., the non-random susceptibility of the different vertebrate clades to purported catastrophic global events 65 million years ago, and new evolutionary opportunities for a subset of vertebrates with the relatively high potential for transoceanic dispersal potential. In comparison, changes in vertebrate class representation during the Cenozoic are minor. Despite the fact that the island's isolation has resulted in high vertebrate endemism and a unique and taxonomically imbalanced extant vertebrate assemblage (both hailed as testimony to its long isolation, that isolation was never complete. Indeed, Madagascar's extant tetrapod fauna owes more to colonization during the Cenozoic than to earlier arrivals. Madagascar's unusual vertebrate assemblage needs to be understood with reference to the basal character of clades originating prior to the K-T extinction, as well as to the differential transoceanic dispersal advantage of

  6. Current and emerging treatment strategies for vertebral compression fractures

    Directory of Open Access Journals (Sweden)

    Hacein-Bey L

    2012-05-01

    Full Text Available Lotfi Hacein-BeyRadiological Associates of Sacramento Medical Group Inc, Sacramento, CA, USABackground: Vertebral compression fractures are most commonly related to osteoporosis or cancer, both of which are on the rise throughout the world. Once a vertebra is fractured, gradual deterioration of quality of life due to crippling pain and spinal instability usually follows. Although a number of traditional management options have been available to promote pain relief and to allow for increased activities, such as bed rest, bracing, pain medications, and light exercise programs, these have limited effectiveness in the majority of patients. Over 20 years ago, percutaneous vertebroplasty, which is a minimally invasive procedure consisting of the injection of polymethylmethacrylate directly into the fractured vertebra, emerged as an effective treatment. Various vertebral augmentation procedures were subsequently designed, all of which aim at eliminating pain, limiting or reversing vertebral collapse, and providing stability to the affected segment of the spine.Objective: This article discusses clinical aspects of vertebral compression fractures, current indications and contraindications and summarizes technical aspects of vertebroplasty, kyphoplasty, lordoplasty, and device-implanting vertebral augmentation procedures. Treatment effectiveness, which is significant despite recent criticism of vertebroplasty and other vertebral augmentation procedures, is also discussed. As economic pressures on health care systems are increasing in all countries, it is expected that the appropriateness, clinical effectiveness, and cost-effectiveness of vertebral augmentation procedures will be increasingly established by outcome analyses.Conclusion: It is important that physicians are familiar with vertebroplasty and other procedures designed to treat vertebral fractures in patients with advanced osteoporosis or cancer. These fractures, which are common and often

  7. Gastrophysa polygoni herbivory on Rumex confertus: single leaf VOC induction and dose dependent herbivore attraction/repellence to individual compounds.

    Science.gov (United States)

    Piesik, Dariusz; Wenda-Piesik, Anna; Kotwica, Karol; Łyszczarz, Alicja; Delaney, Kevin J

    2011-11-15

    We report large induction (>65(fold) increases) of volatile organic compounds (VOCs) emitted from a single leaf of the invasive weed mossy sorrel, Rumex confertus Willd. (Polygonaceae), by herbivory of the dock leaf beetle, Gastrophysa polygoni L. (Coleoptera: Chrysomelidae). The R. confertus VOC blend induced by G. polygoni herbivory included two green leaf volatiles ((Z)-3-hexenal, (Z)-3-hexen-1-yl acetate) and three terpenes (linalool, ß-caryophyllene, (E)-ß-farnesene). Uninjured leaves produced small constitutive amounts of the GLVs and barely detectable amounts of the terpenes. A Y-tube olfactometer bioassay revealed that both sexes of adult G. polygoni were attracted to (Z)-3-hexenal and (Z)-3-hexen-1-yl acetate at a concentration of 300 ng h(-1). No significant G. polygoni attraction or repellence was detected for any VOC at other concentrations (60 and 1500 ng h(-1)). Yet, G. polygoni males and females were significantly repelled by (or avoided) at the highest test concentration (7500 ng h(-1)) of both GLVs and (E)-ß-farnesene. Mated male and female G. polygoni might be attracted to injured R. confertus leaves, but might avoid R. confertus when VOC concentrations (especially the terpene (E)-ß-farnesene) suggest high overall plant injury from conspecifics, G. viridula, or high infestations of other herbivores that release (E)-ß-farnesene (e.g., aphids). Tests in the future will need to examine G. polygoni responses to VOCs emitted directly from uninjured (constitutive) and injured (induced) R. confertus, and examine whether R. confertus VOC induction concentrations increase with greater tissue removal on a single leaf and/or the number of leaves with feeding injury.

  8. The composite effect of transgenic plant volatiles for acquired immunity to herbivory caused by inter-plant communications.

    Directory of Open Access Journals (Sweden)

    Atsushi Muroi

    Full Text Available A blend of volatile organic compounds (VOCs emitted from plants induced by herbivory enables the priming of defensive responses in neighboring plants. These effects may provide insights useful for pest control achieved with transgenic-plant-emitted volatiles. We therefore investigated, under both laboratory and greenhouse conditions, the priming of defense responses in plants (lima bean and corn by exposing them to transgenic-plant-volatiles (VOCos including (E-β-ocimene, emitted from transgenic tobacco plants (NtOS2 that were constitutively overexpressing (E-β-ocimene synthase. When lima bean plants that had previously been placed downwind of NtOS2 in an open-flow tunnel were infested by spider mites, they were more defensive to spider mites and more attractive to predatory mites, in comparison to the infested plants that had been placed downwind of wild-type tobacco plants. This was similarly observed when the NtOS2-downwind maize plants were infested with Mythimna separata larvae, resulting in reduced larval growth and greater attraction of parasitic wasps (Cotesia kariyai. In a greenhouse experiment, we also found that lima bean plants (VOCos-receiver plants placed near NtOS2 were more attractive when damaged by spider mites, in comparison to the infested plants that had been placed near the wild-type plants. More intriguingly, VOCs emitted from infested VOCos-receiver plants affected their conspecific neighboring plants to prime indirect defenses in response to herbivory. Altogether, these data suggest that transgenic-plant-emitted volatiles can enhance the ability to prime indirect defenses via both plant-plant and plant-plant-plant communications.

  9. Epiphytes and nutrient contents influence Sarpa salpa herbivory on Caulerpa spp vs. seagrass species in Mediterranean meadows

    Science.gov (United States)

    Marco-Méndez, Candela; Ferrero-Vicente, Luis Miguel; Prado, Patricia; Sánchez-Lizaso, Jose Luis

    2017-01-01

    Mediterranean seagrass ecosystems are endangered by increased colonization of Caulerpa species, which may replace them, affecting key ecosystem processes. The fish Sarpa salpa (L.) is one of the main macroherbivores in the western Mediterranean seagrass meadows which is known to feed on a wide range of macroalgae such as Caulerpa species. In order to elucidate if this consumption could minimize the spread of invasive species, during summer-autumn 2012, we investigate the importance of S. salpa herbivory pressure on C. prolifera and C. cylindracea compared to Posidonia oceanica and Cymodocea nodosa in a mixed meadow. A combination of field experiments and dietary analyses were used to investigate consumption rates, dietary contributions, and feeding preferences for the different macrophytes, including the role of epiphytes and nutrient contents in mediating fish herbivory. In summer, C. nodosa was the most consumed macrophyte (12.75 ± 3.43 mg WW·d-1), probably influenced by higher fish densities, higher nutritional quality of leaves and epiphytes, and by differences in epiphyte composition. Feeding observations suggest that fish may have a variable diet, although with a consistent selection of mixed patches with C. nodosa and C. prolifera. Indeed, food choice experiments suggest that when seagrass leaves are not epiphytized, fish prefer feeding on C. prolifera. Gut content and stable isotopic analyses supported the dietary importance of epiphytes and C. prolifera but also suggested that C. cylindracea could occasionally be an important food item for S. salpa. Our results highlight the role of epiphytes in S. salpa feeding decisions but also suggest that C. nodosa and C. prolifera may have an important contribution to fish diet. The variability in S. salpa diet confirm the need to carry out multiple approach studies for a better understanding of its potential influence over different macrophytes species.

  10. Arthropod assemblage related to volatile cues in flowering wheat: interaction between aphid herbivory and soil conditions as induction factors.

    Science.gov (United States)

    Lenardis, Adriana E; Szpeiner, Alfonsina; Ghersa, Claudio M

    2014-04-01

    Volatile cues released by plants play an important role in plant-insect interactions and are influenced by pests or soil conditions affecting plant metabolism. Field microcosm experiments were used to characterize arthropod spontaneous assemblies in homogenous unstressed wheat patches exposed to volatile cues coming from wheat plants with different levels of stress. The design was a factorial completely randomized block design with three replications. Source wheat pots combined two stress factors: 1) soil degradation level: high and low, and 2) aphid herbivory: with (A) and without (B). Eighteen experimental units consisted of source stressed wheat pots, connected by tubes conducting the volatile cues to sink wheat patches. These patches were located at the end of the tubes placed in a flowering wheat field. Arthropod assemblies on wheat sinks were different between years and they were associated to the source cues. Soil condition was the main discriminating factor among arthropods when a clear contrast between high and low soil degradation was observed, whereas aphid herbivory was the main discriminating factor when soil condition effects were absent. Main soil properties related with arthropods assembly were Mg and K in the first year and cation exchange capacity, total nitrogen, and pH in the second year of experiment. According to this study, spontaneous arthropod distributions in the homogeneous, unstressed wheat patch responded to the volatile cues coming from wheat sources growing in particular soil conditions. It is possible to suggest that soil-plant-herbivore interactions change wheat cues and this phenomenon produces significant differences in neighboring arthropod community structure.

  11. Ischemic stroke: carotid and vertebral artery disease

    Energy Technology Data Exchange (ETDEWEB)

    Vilela, P.; Goulao, A. [Hospital Garcia de Orta, Servico de Neurorradiologia, Almada (Portugal)

    2005-03-01

    Ischemic strokes may have distinct aetiologies, including several different intrinsic arterial pathological disorders. The diagnosis and understanding of these arterial diseases is critical for the correct management of stroke as different treatment approaches are undertaken according to the aetiology. Atherosclerosis is by far the most common arterial disease among adults, and other pathological processes include arterial dissection, small vessel disease, inflammatory and non-inflammatory vasculopathy and vasomotor disorders. In children, there are several vasculopathies responsible for vaso-occlusive disease such as sickle-cell anemia, acute regressive angiopathy and Moya-Moya disease, neurofibromatosis, dissections, vasculitis associated with intracranial and systemic infections. An overview of the major carotid and vertebral pathological diseases responsible for ischemic stroke in adults and children, highlighting the accuracy of the different imaging modalities for its diagnosis and the imaging appearance of these diseases, is given. (orig.)

  12. Magnetic Susceptibility in the Vertebral Column

    Science.gov (United States)

    Schick, F.; Nagele, T.; Lutz, O.; Pfeffer, K.; Giehl, J.

    1994-01-01

    A magnetic resonance method is described which provides good-quality field-mapping images of the spine, although the in vivo signals from red bone marrow of the vertebral bodies exhibit similar fractions of lipid and water protons with their chemical-shift difference of 3.4 ppm. The susceptibilities of bone marrow and intervertebral disks were examined in 20 cadaveric human spines, 9 healthy volunteers, and 9 patients with degenerative disk alterations. The influence of geometrical properties was studied in cylindrical spine phantoms of different size and contents with different susceptibility. The measurements reveal interindividual differences of the susceptibility of the intervertebral disks in healthy subjects. Three out of nine degenerated disks with low signal in T2-weighted spin-echo images showed irregularities of the field distribution within the nucleus pulposus.

  13. Vertebral Augmentation: State of the Art

    Science.gov (United States)

    Nabhane, Linda; Issa El Khoury, Fouad; Kreichati, Gaby; El Rachkidi, Rami

    2016-01-01

    Osteoporotic vertebral compression fractures (OVF) are an increasing public health problem. Cement augmentation (vertebroplasty of kyphoplasty) helps stabilize painful OVF refractory to medical treatment. This stabilization is thought to improve pain and functional outcome. Vertebroplasty consists of injecting cement into a fractured vertebra using a percutaneous transpedicular approach. Balloon kyphoplasty uses an inflatable balloon prior to injecting the cement. Although kyphoplasty is associated with significant improvement of local kyphosis and less cement leakage, this does not result in long-term clinical and functional improvement. Moreover, vertebroplasty is favored by some due to the high cost of kyphoplasty. The injection of cement increases the stiffness of the fracture vertebrae. This can lead, in theory, to adjacent OVF. However, many studies found no increase of subsequent fracture when comparing medical treatment to cement augmentation. Kyphoplasty can have a protective effect due to restoration of sagittal balance. PMID:27114782

  14. Vertebral heart scores in eight dog breeds.

    Science.gov (United States)

    Jepsen-Grant, K; Pollard, R E; Johnson, L R

    2013-01-01

    The vertebral heart score (VHS) measurement is commonly used to provide a more objective measurement of cardiomegaly in canines. However, several studies have shown significant breed variations from the value previously established by Buchanan and Bücheler (9.7 ± 0.5). This study describes VHS measurements in Pug, Pomeranian, Yorkshire Terrier, Dachshund, Bulldog, Shih Tzu, Lhasa Apso, and Boston Terrier dog breeds. Dogs with two or three view thoracic radiographs, no subjective radiographic evidence of cardiomegaly, and no physical examination findings of heart murmurs or gallop rhythms were included in the study. The Pug, Pomeranian, Bulldog, and Boston Terrier groups were found to have a VHS significantly greater than 9.7 ± 0.5 (P Bulldog (P = 0.028) and Boston Terrier (P = 0.0004) groups. Thoracic depth to width ratio did not have a significant effect on VHS.

  15. Vertebral surface registration using ridgelines/crestlines

    Science.gov (United States)

    Tan, Sovira; Yao, Jianhua; Yao, Lawrence; Summers, Ronald M.; Ward, Michael M.

    2008-03-01

    The Iterative Closest Point (ICP) algorithm is an efficient and popular technique for surface registration. It however suffers from the well-known problem of local minima that make the algorithm stop before it reaches the desired global solution. ICP can be improved by the use of landmarks or features. We recently developed a level set capable of evolving on the surface of an object represented by a triangular mesh. This level set permits the segmentation of portions of a surface based on curvature features. The boundary of a segmented portion forms a ridgeline/crestline. We show that the ridgelines/crestlines and corresponding enclosed surfaces extracted by the algorithm can substantially improve ICP registration. We compared the performance of an ICP algorithm in three setups: 1) ICP without landmarks. 2) ICP using ridgelines. 3) ICP using ridgelines and corresponding enclosed surfaces. Our material consists of vertebral body surfaces extracted for a study about the progression of Ankylosing Spondylitis. Same vertebrae scanned at intervals of one or two years were rigidly registered. Vertebral body rims and the end plate surfaces they enclose were used as landmarks. The performance measure was the mean error distance between the registered surfaces. From the one hundred registrations that we performed the average mean error was respectively 0.503mm, 0.335mm and 0.254mm for the three setups. Setup 3 almost halved the average error of setup 1. Moreover the error range is dramatically reduced from [0.0985, 2.19]mm to just [0.0865, 0.532]mm, making the algorithm very robust.

  16. Pharyngo-vertebral fistula secondary to cervical vertebral fracture in a patient with stab wound.

    Science.gov (United States)

    Choi, Jeong Hwan

    2014-02-01

    Pharyngo-vertebral fistula (PVF) associated with cervical (C) spinal fracture is an extremely rare event that may lead to life-threatening infectious complications if not recognized promptly. Successful management of PVF depends on the physicians' awareness of the causes, prompt recognition of the symptoms and clinical findings, and immediate institution of treatment. I report a case of PVF after C3 vertebral body fracture that was initially neglected and subsequently developed into osteomyelitis involving adjacent vertebrae. On computed tomography and magnetic resonance imaging showed a PVF. Despite conservative care, spontaneous closure of the fistula was not achieved. Removal of PVF and surrounding granulation was achieved without any complication. To the best of my knowledge, PVF as a complication of C spine fracture has not hitherto been reported in the English literature.

  17. Congenital abnormalities of the vertebral column in ferrets.

    Science.gov (United States)

    Proks, Pavel; Stehlik, Ladislav; Paninarova, Michaela; Irova, Katarina; Hauptman, Karel; Jekl, Vladimir

    2015-01-01

    Vertebral column pathologies requiring surgical intervention have been described in pet ferrets, however little information is available on the normal vertebral formula and congenital variants in this species. The purpose of this retrospective study was to describe vertebral formulas and prevalence of congenital vertebral anomalies in a sample of pet ferrets. Radiographs of 172 pet ferrets (96 males and 76 females) were included in this retrospective study. In 143 ferrets (83.14%), five different formulas of the vertebral column were recorded with normal morphology of vertebrae (rib attachment included) but with a variable number of thoracic (Th), lumbar (L), and sacral (S) vertebrae. The number of cervical (C) vertebrae was constant in all examined animals. Observed vertebral formulas were C7/Th14/L6/S3 (51.74%), C7/Th14/L6/S4 (22.10%), C7/Th14/L7/S3 (6.98%), C7/Th15/L6/S3 (1.74%), and C7/Th15/L6/S4 (0.58%). Formula C7/Th14/L6/S4 was significantly more common in males than in females (P vertebral anomalies included block (two ferrets) and wedge vertebra (one ferret). Spina bifida was not detected. Findings from the current study indicated that vertebral formulas may vary in ferrets and congenital abnormalities are common. This should be taken into consideration for surgical planning.

  18. Variability and constraint in the mammalian vertebral column.

    Science.gov (United States)

    Asher, R J; Lin, K H; Kardjilov, N; Hautier, L

    2011-05-01

    Patterns of vertebral variation across mammals have seldom been quantified, making it difficult to test hypotheses of covariation within the axial skeleton and mechanisms behind the high level of vertebral conservatism among mammals. We examined variation in vertebral counts within 42 species of mammals, representing monotremes, marsupials and major clades of placentals. These data show that xenarthrans and afrotherians have, on average, a high proportion of individuals with meristic deviations from species' median series counts. Monotremes, xenarthrans, afrotherians and primates show relatively high variation in thoracolumbar vertebral count. Among the clades sampled in our dataset, rodents are the least variable, with several species not showing any deviations from median vertebral counts, or vertebral anomalies such as asymmetric ribs or transitional vertebrae. Most mammals show significant correlations between sacral position and length of the rib cage; only a few show a correlation between sacral position and number of sternebrae. The former result is consistent with the hypothesis that adult axial skeletal structures patterned by distinct mesodermal tissues are modular and covary; the latter is not. Variable levels of correlation among these structures may indicate that the boundaries of prim/abaxial mesodermal precursors of the axial skeleton are not uniform across species. We do not find evidence for a higher frequency of vertebral anomalies in our sample of embryos or neonates than in post-natal individuals of any species, contrary to the hypothesis that stabilizing selection plays a major role in vertebral patterning.

  19. 50 CFR 17.84 - Special rules-vertebrates.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 2 2010-10-01 2010-10-01 false Special rules-vertebrates. 17.84 Section 17.84 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR....84 Special rules—vertebrates. (a) Delmarva Peninsula fox squirrel (Sciurus niger cinereus). (1)...

  20. Collection & Processing of Vertebrate Specimens for Arbovirus Studies.

    Science.gov (United States)

    Sudia, W. Daniel; And Others

    Described are techniques used by the National Communicable Disease Center in obtaining blood and tissues from man and other vertebrates for arbovirus isolation and antibody studies. Also included are techniques for capturing and handling vertebrates; banding and marking; restraining and bleeding; storing of specimens to preserve antibody and…

  1. Cooperative Learning as a Tool To Teach Vertebrate Anatomy.

    Science.gov (United States)

    Koprowski, John L.; Perigo, Nan

    2000-01-01

    Describes a method for teaching biology that includes more investigative exercises that foster an environment for cooperative learning in introductory laboratories that focus on vertebrates. Fosters collaborative learning by facilitating interaction between students as they become experts on their representative vertebrate structures. (SAH)

  2. Fossil jawless fish from China foreshadows early jawed vertebrate anatomy.

    Science.gov (United States)

    Gai, Zhikun; Donoghue, Philip C J; Zhu, Min; Janvier, Philippe; Stampanoni, Marco

    2011-08-17

    Most living vertebrates are jawed vertebrates (gnathostomes), and the living jawless vertebrates (cyclostomes), hagfishes and lampreys, provide scarce information about the profound reorganization of the vertebrate skull during the evolutionary origin of jaws. The extinct bony jawless vertebrates, or 'ostracoderms', are regarded as precursors of jawed vertebrates and provide insight into this formative episode in vertebrate evolution. Here, using synchrotron radiation X-ray tomography, we describe the cranial anatomy of galeaspids, a 435-370-million-year-old 'ostracoderm' group from China and Vietnam. The paired nasal sacs of galeaspids are located anterolaterally in the braincase, and the hypophyseal duct opens anteriorly towards the oral cavity. These three structures (the paired nasal sacs and the hypophyseal duct) were thus already independent of each other, like in gnathostomes and unlike in cyclostomes and osteostracans (another 'ostracoderm' group), and therefore have the condition that current developmental models regard as prerequisites for the development of jaws. This indicates that the reorganization of vertebrate cranial anatomy was not driven deterministically by the evolutionary origin of jaws but occurred stepwise, ultimately allowing the rostral growth of ectomesenchyme that now characterizes gnathostome head development.

  3. The generation of vertebral segmental patterning in the chick embryo.

    Science.gov (United States)

    Senthinathan, Biruntha; Sousa, Cátia; Tannahill, David; Keynes, Roger

    2012-06-01

    We have carried out a series of experimental manipulations in the chick embryo to assess whether the notochord, neural tube and spinal nerves influence segmental patterning of the vertebral column. Using Pax1 expression in the somite-derived sclerotomes as a marker for segmentation of the developing intervertebral disc, our results exclude such an influence. In contrast to certain teleost species, where the notochord has been shown to generate segmentation of the vertebral bodies (chordacentra), these experiments indicate that segmental patterning of the avian vertebral column arises autonomously in the somite mesoderm. We suggest that in amniotes, the subdivision of each sclerotome into non-miscible anterior and posterior halves plays a critical role in establishing vertebral segmentation, and in maintaining left/right alignment of the developing vertebral elements at the body midline.

  4. A STUDY ON THORACIC VERTEBRAL SYNOSTOSIS & ITS CLINICAL IMPORTANCE

    Directory of Open Access Journals (Sweden)

    Md. Khaleel

    2015-01-01

    Full Text Available Vertebral anomalies are of interest not only to anatomist, but also to orthopedician, neurologist & neurosurgeons. Various vertebral anomalies of anatomic interest have been reported namely; occipitalisation, sacralisation, lumbarisation, absence of posterior elements of vertebral arch & vertebral s ynostosis. The fusion of vertebral column is rare anomalies usually congenital in origin. The fusion of thoracic vertebrae can present many clinical sign including congenital scoliosis. A study on 594 dry adult human vertebrae of unknown age & sex collected from the department of anatomy and phase I students of KBNIMS, Kalaburagi, Karnataka. The study was done over a period of 6 months (July to December 2014 during routine osteology classes for 1 year MBBS, we found the fusion of typical thoracic vertebrae between T 3 & T 4 . The cause could be failure of re - segmentation of somitomeres or acquired.

  5. Non-contiguous multifocal vertebral osteomyelitis caused by Serratia marcescens.

    Science.gov (United States)

    Lau, Jen Xin; Li, Jordan Yuanzhi; Yong, Tuck Yean

    2015-03-01

    Serratia marcescens is a common nosocomial infection but a rare cause of osteomyelitis and more so of vertebral osteomyelitis. Vertebral osteomyelitis caused by this organism has been reported in few studies. We report a case of S. marcescens vertebral discitis and osteomyelitis affecting multiple non-contiguous vertebras. Although Staphylococcus aureus is the most common cause of vertebral osteomyelitis, rare causes, such as S. marcescens, need to be considered, especially when risk factors such as intravenous heroin use, post-spinal surgery and immunosuppression are present. Therefore, blood culture and where necessary biopsy of the infected region should be undertaken to establish the causative organism and determine appropriate antibiotic susceptibility. Prompt diagnosis of S. marcescens vertebral osteomyelitis followed by the appropriate treatment can achieve successful outcomes.

  6. Control of vertebrate skeletal mineralization by polyphosphates.

    Directory of Open Access Journals (Sweden)

    Sidney Omelon

    Full Text Available BACKGROUND: Skeletons are formed in a wide variety of shapes, sizes, and compositions of organic and mineral components. Many invertebrate skeletons are constructed from carbonate or silicate minerals, whereas vertebrate skeletons are instead composed of a calcium phosphate mineral known as apatite. No one yet knows why the dynamic vertebrate skeleton, which is continually rebuilt, repaired, and resorbed during growth and normal remodeling, is composed of apatite. Nor is the control of bone and calcifying cartilage mineralization well understood, though it is thought to be associated with phosphate-cleaving proteins. Researchers have assumed that skeletal mineralization is also associated with non-crystalline, calcium- and phosphate-containing electron-dense granules that have been detected in vertebrate skeletal tissue prepared under non-aqueous conditions. Again, however, the role of these granules remains poorly understood. Here, we review bone and growth plate mineralization before showing that polymers of phosphate ions (polyphosphates: (PO(3(-(n are co-located with mineralizing cartilage and resorbing bone. We propose that the electron-dense granules contain polyphosphates, and explain how these polyphosphates may play an important role in apatite biomineralization. PRINCIPAL FINDINGS/METHODOLOGY: The enzymatic formation (condensation and destruction (hydrolytic degradation of polyphosphates offers a simple mechanism for enzymatic control of phosphate accumulation and the relative saturation of apatite. Under circumstances in which apatite mineral formation is undesirable, such as within cartilage tissue or during bone resorption, the production of polyphosphates reduces the free orthophosphate (PO(4(3- concentration while permitting the accumulation of a high total PO(4(3- concentration. Sequestering calcium into amorphous calcium polyphosphate complexes can reduce the concentration of free calcium. The resulting reduction of both free PO

  7. ANATOMICAL VARIATIONS IN CONDUIT OF VERTEBRAL ARTERY IN ATLAS

    Directory of Open Access Journals (Sweden)

    Krishna

    2013-10-01

    Full Text Available ABSTRACT : BACKGROUND: The 1 st cervical vertebra is named as atlas. It differs from all the other vertebrae in having no body and no spine. The atlas consists of two bulky lateral masses, connected to each other in front by a short anterior arch, and behind by a long curved posterior arch it thus forms a ring of bone. The posterior arch forms three - fifths of the atlantal ring. At the r oot of the arch the superior surface of posterior arch bears a wide groove for the vertebral artery, venous plexus and the C1 nerve immediately behind the lateral mass. In few cases this groove is converted into the completely or partially posterior/latera l vertebral artery foramen. AIM : This study was carried out to know the variations in posterior vertebral artery groove in atlas vertebra for clinical and surgical purpose. MATERIALS AND METHODS: The present study is based on the observation of the 300 mac erated Human atlas vertebrae of North Indian present in the Anthropology Museum of Department of Anatomy, GSVM Medical College, Kanpur. The atlases were randomly selected the age and sex were not taken into consideration. RESULTS: We observed the complete posterior vertebral artery foramen in 8% specimen (2.33% bilateral and 5.67% unilateral. In 3.33% it was found on left side and 2.33% on right side. Incidence of incomplete posterior vertebral artery foramen was observed in 9.33% (1.33% bilateral and 8% u nilateral. In 5% it was found on left side and 3% on right side. The bilateral presence of complete or incomplete lateral vertebral artery foramen was nil. The unilateral presence of complete or incomplete lateral vertebral artery foramen was found equal in frequency i.e. 0.67%. The unilateral presence of complete lateral vertebral artery foramen on either side was found in 0.33% specimen whereas the incomplete lateral vertebral artery foramen was found only on left side (0.67%. CONCLUSION : The presence o f complete/incomplete posterior or lateral

  8. Conodonts, Calcichordates and the Origin of Vertebrates

    Directory of Open Access Journals (Sweden)

    J. Bergström

    1998-01-01

    Full Text Available Interpretation of early deuterostome evolution and relationships has been hampered by the lack of soft-part preservation in most groups. In addition, a recently revealed upside-down life orientation of vertebrates (the only real notoneuralians compared to other bilateral animals has been misinterpreted as evidence for a unique body design in all deuterostomes, misleading any search for relatives. Regarding echinoderms, the variety of body plans is confusing. The interpretation of some fossils with echinoderm-type calcite skeletons as “calcichordate” ancestors of chordates, however, involves a hypothetical reconstruction of an unusual body plan and a long series of hypothetical transitions. The number of necessary steps is much lower if cephalochordates (amphioxus or lancelet are derived directly from hemichordate enteropneusts. “Sensation interpretations” of fossils (Yunnanozoon, Cathaymyrus from Burgess Shale type deposits have added further confusion. Soft-part preservation of conodont animals, with V-shaped myomeres and a notochord, shows that they were segmented chordates, while probable eyes and teeth suggest that they were already on the vertebrate side. Die Interpretation früher Deuterostomia hinsichtlich ihrer Evolution und verwandtschaftlichen Beziehungen ist in den meisten Gruppen durch den Mangel an Weichkörpererhaltung sehr erschwert. Die kürzlich entdeckte Tatsache, daß Vertebraten, d. h. die einzigen echten Notoneuralia, im Gegensatz zu anderen bilateral symmetrischen Organismen eine mit ihrer ursprünglichen Oberseite nach unten gerichtete Lebensstellung einnehmen, hat zu der irrtümlichen Ansicht geführt, daß alle Deuostomia über einen im Tierreich einzigartigen Bauplan verfügen. Diese Interpretation brachte naturgemäß jede Suche nach Verwandtschaftsverhältnissen auf Abwege. Hinsichtlich der Echinodermata ist die bauplanmäßige Variation in der Tat verwirrend. Die Interpretation einiger Fossilien mit

  9. Do lower vertebrates suffer from motion sickness?

    Science.gov (United States)

    Lychakov, Dmitri

    The poster presents literature data and results of the author’s studies with the goal to find out whether the lower animals are susceptible to motion sickness (Lychakov, 2012). In our studies, fish and amphibians were tested for 2 h and more by using a rotating device (f = 0.24 Hz, a _{centrifugal} = 0.144 g) and a parallel swing (f = 0.2 Hz, a _{horizontal} = 0.059 g). The performed studies did not revealed in 4 fish species and in toads any characteristic reactions of the motion sickness (sopite syndrome, prodromal preparatory behavior, vomiting). At the same time, in toads there appeared characteristic stress reactions (escape response, an increase of the number of urinations, inhibition of appetite), as well as some other reactions not associated with motion sickness (regular head movements, eye retractions). In trout fry the used stimulation promoted division of the individuals into the groups differing by locomotor reaction to stress, as well as the individuals with the well-expressed compensatory reaction that we called the otolithotropic reaction. Analysis of results obtained by other authors confirms our conclusions. Thus, the lower vertebrates, unlike mammals, are immune to motion sickness either under the land conditions or under conditions of weightlessness. On the basis of available experimental data and theoretical concepts of mechanisms of development the motion sickness, formulated in several hypotheses (mismatch hypothesis, Traisman‘ s hypothesis, resonance hypothesis), there presented the synthetic hypothesis of motion sickness that has the conceptual significance. According to the hypothesis, the unusual stimulation producing sensor-motor or sensor-sensor conflict or an action of vestibular and visual stimuli of frequency of about 0.2 Hz is perceived by CNS as poisoning and causes the corresponding reactions. The motion sickness actually is a byproduct of technical evolution. It is suggested that in the lower vertebrates, unlike mammals

  10. Future warming and acidification effects on anti-fouling and anti-herbivory traits of the brown alga Fucus vesiculosus (Phaeophyceae).

    Science.gov (United States)

    Raddatz, Stefanie; Guy-Haim, Tamar; Rilov, Gil; Wahl, Martin

    2017-02-01

    Human-induced ocean warming and acidification have received increasing attention over the past decade and are considered to have substantial consequences for a broad range of marine species and their interactions. Understanding how these interactions shift in response to climate change is particularly important with regard to foundation species, such as the brown alga Fucus vesiculosus. This macroalga represents the dominant habitat former on coastal rocky substrata of the Baltic Sea, fulfilling functions essential for the entire benthic community. Its ability to withstand extensive fouling and herbivory regulates the associated community and ecosystem dynamics. This study tested the interactive effects of future warming, acidification, and seasonality on the interactions of a marine macroalga with potential foulers and consumers. F. vesiculosus rockweeds were exposed to different combinations of conditions predicted regionally for the year 2100 (+∆5°C, +∆700 μatm CO2 ) using multifactorial long-term experiments in novel outdoor benthic mesocosms ("Benthocosms") over 9-12-week periods in four seasons. Possible shifts in the macroalgal susceptibility to fouling and consumption were tested using consecutive bioassays. Algal susceptibility to fouling and grazing varied substantially among seasons and between treatments. In all seasons, warming predominantly affected anti-fouling and anti-herbivory interactions while acidification had a subtle nonsignificant influence. Interestingly, anti-microfouling activity was highest during winter under warming, while anti-macrofouling and anti-herbivory activities were highest in the summer under warming. These contrasting findings indicate that seasonal changes in anti-fouling and anti-herbivory traits may interact with ocean warming in altering F. vesiculosus community composition in the future.

  11. A revised metric for quantifying body shape in vertebrates.

    Science.gov (United States)

    Collar, David C; Reynaga, Crystal M; Ward, Andrea B; Mehta, Rita S

    2013-08-01

    Vertebrates exhibit tremendous diversity in body shape, though quantifying this variation has been challenging. In the past, researchers have used simplified metrics that either describe overall shape but reveal little about its anatomical basis or that characterize only a subset of the morphological features that contribute to shape variation. Here, we present a revised metric of body shape, the vertebrate shape index (VSI), which combines the four primary morphological components that lead to shape diversity in vertebrates: head shape, length of the second major body axis (depth or width), and shape of the precaudal and caudal regions of the vertebral column. We illustrate the usefulness of VSI on a data set of 194 species, primarily representing five major vertebrate clades: Actinopterygii, Lissamphibia, Squamata, Aves, and Mammalia. We quantify VSI diversity within each of these clades and, in the course of doing so, show how measurements of the morphological components of VSI can be obtained from radiographs, articulated skeletons, and cleared and stained specimens. We also demonstrate that head shape, secondary body axis, and vertebral characteristics are important independent contributors to body shape diversity, though their importance varies across vertebrate groups. Finally, we present a functional application of VSI to test a hypothesized relationship between body shape and the degree of axial bending associated with locomotor modes in ray-finned fishes. Altogether, our study highlights the promise VSI holds for identifying the morphological variation underlying body shape diversity as well as the selective factors driving shape evolution.

  12. Evolution of adaptive immune recognition in jawless vertebrates.

    Science.gov (United States)

    Saha, Nil Ratan; Smith, Jeramiah; Amemiya, Chris T

    2010-02-01

    All extant vertebrates possess an adaptive immune system wherein diverse immune receptors are created and deployed in specialized blood cell lineages. Recent advances in DNA sequencing and developmental resources for basal vertebrates have facilitated numerous comparative analyses that have shed new light on the molecular and cellular bases of immune defense and the mechanisms of immune receptor diversification in the "jawless" vertebrates. With data from these key species in hand, it is becoming possible to infer some general aspects of the early evolution of vertebrate adaptive immunity. All jawed vertebrates assemble their antigen-receptor genes through combinatorial recombination of different "diversity" segments into immunoglobulin or T-cell receptor genes. However, the jawless vertebrates employ an analogous, but independently derived set of immune receptors in order to recognize and bind antigens: the variable lymphocyte receptors (VLRs). The means by which this locus generates receptor diversity and achieves antigen specificity is of considerable interest because these mechanisms represent a completely independent strategy for building a large immune repertoire. Therefore, studies of the VLR system are providing insight into the fundamental principles and evolutionary potential of adaptive immune recognition systems. Here we review and synthesize the wealth of data that have been generated towards understanding the evolution of the adaptive immune system in the jawless vertebrates.

  13. A unified anatomy ontology of the vertebrate skeletal system.

    Directory of Open Access Journals (Sweden)

    Wasila M Dahdul

    Full Text Available The skeleton is of fundamental importance in research in comparative vertebrate morphology, paleontology, biomechanics, developmental biology, and systematics. Motivated by research questions that require computational access to and comparative reasoning across the diverse skeletal phenotypes of vertebrates, we developed a module of anatomical concepts for the skeletal system, the Vertebrate Skeletal Anatomy Ontology (VSAO, to accommodate and unify the existing skeletal terminologies for the species-specific (mouse, the frog Xenopus, zebrafish and multispecies (teleost, amphibian vertebrate anatomy ontologies. Previous differences between these terminologies prevented even simple queries across databases pertaining to vertebrate morphology. This module of upper-level and specific skeletal terms currently includes 223 defined terms and 179 synonyms that integrate skeletal cells, tissues, biological processes, organs (skeletal elements such as bones and cartilages, and subdivisions of the skeletal system. The VSAO is designed to integrate with other ontologies, including the Common Anatomy Reference Ontology (CARO, Gene Ontology (GO, Uberon, and Cell Ontology (CL, and it is freely available to the community to be updated with additional terms required for research. Its structure accommodates anatomical variation among vertebrate species in development, structure, and composition. Annotation of diverse vertebrate phenotypes with this ontology will enable novel inquiries across the full spectrum of phenotypic diversity.

  14. A unified anatomy ontology of the vertebrate skeletal system.

    Science.gov (United States)

    Dahdul, Wasila M; Balhoff, James P; Blackburn, David C; Diehl, Alexander D; Haendel, Melissa A; Hall, Brian K; Lapp, Hilmar; Lundberg, John G; Mungall, Christopher J; Ringwald, Martin; Segerdell, Erik; Van Slyke, Ceri E; Vickaryous, Matthew K; Westerfield, Monte; Mabee, Paula M

    2012-01-01

    The skeleton is of fundamental importance in research in comparative vertebrate morphology, paleontology, biomechanics, developmental biology, and systematics. Motivated by research questions that require computational access to and comparative reasoning across the diverse skeletal phenotypes of vertebrates, we developed a module of anatomical concepts for the skeletal system, the Vertebrate Skeletal Anatomy Ontology (VSAO), to accommodate and unify the existing skeletal terminologies for the species-specific (mouse, the frog Xenopus, zebrafish) and multispecies (teleost, amphibian) vertebrate anatomy ontologies. Previous differences between these terminologies prevented even simple queries across databases pertaining to vertebrate morphology. This module of upper-level and specific skeletal terms currently includes 223 defined terms and 179 synonyms that integrate skeletal cells, tissues, biological processes, organs (skeletal elements such as bones and cartilages), and subdivisions of the skeletal system. The VSAO is designed to integrate with other ontologies, including the Common Anatomy Reference Ontology (CARO), Gene Ontology (GO), Uberon, and Cell Ontology (CL), and it is freely available to the community to be updated with additional terms required for research. Its structure accommodates anatomical variation among vertebrate species in development, structure, and composition. Annotation of diverse vertebrate phenotypes with this ontology will enable novel inquiries across the full spectrum of phenotypic diversity.

  15. Fatal Vertebral Artery Injury in Penetrating Cervical Spine Trauma

    Directory of Open Access Journals (Sweden)

    Chadi Tannoury

    2015-01-01

    Full Text Available Study Design. This case illustrates complications to a vertebral artery injury (VAI resulting from penetrating cervical spine trauma. Objectives. To discuss the management of both VAI and cervical spine trauma after penetrating gunshot wound to the neck. Summary of Background Data. Vertebral artery injury following cervical spine trauma is infrequent, and a unilateral VAI often occurs without neurologic sequela. Nevertheless, devastating complications of stroke and death do occur. Methods. A gunshot wound to the neck resulted in a C6 vertebral body fracture and C5–C7 transverse foramina fractures. Neck CT angiogram identified a left vertebral artery occlusion. A cerebral angiography confirmed occlusion of the left extracranial vertebral artery and patency of the remaining cerebrovascular system. Following anterior cervical corpectomy and stabilization, brainstem infarction occurred and resulted in death. Results. A fatal outcome resulted from vertebral artery thrombus propagation with occlusion of the basilar artery triggering basilar ischemia and subsequent brainstem and cerebellar infarction. Conclusions. Vertebral artery injury secondary to cervical spine trauma can lead to potentially devastating neurologic sequela. Early surgical stabilization, along with anticoagulation therapy, contributes towards managing the combination of injuries. Unfortunately, despite efforts, a poor outcome is sometimes inevitable when cervical spine trauma is coupled with a VAI.

  16. The variable effects of soil nitrogen availability and insect herbivory on aboveground and belowground plant biomass in an old-field ecosystem.

    Science.gov (United States)

    Blue, Jarrod D; Souza, Lara; Classen, Aimée T; Schweitzer, Jennifer A; Sanders, Nathan J

    2011-11-01

    Nutrient availability and herbivory can regulate primary production in ecosystems, but little is known about how, or whether, they may interact with one another. Here, we investigate how nitrogen availability and insect herbivory interact to alter aboveground and belowground plant community biomass in an old-field ecosystem. In 2004, we established 36 experimental plots in which we manipulated soil nitrogen (N) availability and insect abundance in a completely randomized plot design. In 2009, after 6 years of treatments, we measured aboveground biomass and assessed root production at peak growth. Overall, we found a significant effect of reduced soil N availability on aboveground biomass and belowground plant biomass production. Specifically, responses of aboveground and belowground community biomass to nutrients were driven by reductions in soil N, but not additions, indicating that soil N may not be limiting primary production in this ecosystem. Insects reduced the aboveground biomass of subdominant plant species and decreased coarse root production. We found no statistical interactions between N availability and insect herbivory for any response variable. Overall, the results of 6 years of nutrient manipulations and insect removals suggest strong bottom-up influences on total plant community productivity but more subtle effects of insect herbivores on aspects of aboveground and belowground production.

  17. Observer agreement in pediatric semiquantitative vertebral fracture diagnosis

    Energy Technology Data Exchange (ETDEWEB)

    Siminoski, Kerry [University of Alberta, Department of Radiology and Diagnostic Imaging and Division of Endocrinology and Metabolism, Department of Medicine, Edmonton (Canada); Lentle, Brian [University of British Columbia, Department of Radiology, Vancouver (Canada); BC Children' s Hospital, Department of Radiology, Vancouver (Canada); Matzinger, Mary Ann; Shenouda, Nazih [University of Ottawa, Department of Diagnostic Imaging, Ottawa (Canada); Children' s Hospital of Eastern Ontario, Department of Medical Imaging, Ottawa (Canada); Ward, Leanne M. [University of Ottawa, Department of Pediatrics, Children' s Hospital of Eastern Ontario, Ottawa (Canada); Children' s Hospital of Eastern Ontario, Research Institute, Ottawa (Canada); Collaboration: The Canadian STOPP Consortium

    2014-04-15

    The Genant semiquantitative (GSQ) method has been a standard procedure for diagnosis of vertebral fractures in adults but has only recently been shown to be of clinical utility in children. Observer agreement using the GSQ method in this age group has not been described. To evaluate observer agreement on vertebral readability and vertebral fracture diagnosis using the GSQ method in pediatric vertebral morphometry. Spine radiographs of 186 children with acute lymphoblastic leukemia were evaluated independently by three radiologists using the same GSQ methodology as in adults. A subset of 100 radiographs was evaluated on two occasions. An average of 4.7% of vertebrae were unreadable for the three radiologists. Intraobserver Cohen's kappa (κ) on readability ranged from 0.434 to 0.648 at the vertebral level and from 0.416 to 0.611 at the patient level, while interobserver κ for readability had a range of 0.330 to 0.504 at the vertebral level and 0.295 to 0.467 at the patient level. Intraobserver κ for the presence of vertebral fracture had a range of 0.529 to 0.726 at the vertebral level and was 0.528 to 0.767 at the patient level. Interobserver κ for fracture at the vertebral level ranged from 0.455 to 0.548 and from 0.433 to 0.486 at the patient level. Most κ values for both intra- and interobserver agreement in applying the GSQ method to pediatric spine radiographs were in the moderate to substantial range, comparable to the performance of the technique in adult studies. The GSQ method should be considered for use in pediatric research and clinical practice. (orig.)

  18. Gut Melatonin in Vertebrates: Chronobiology and Physiology.

    Science.gov (United States)

    Mukherjee, Sourav; Maitra, Saumen Kumar

    2015-01-01

    Melatonin, following discovery in the bovine pineal gland, has been detected in several extra-pineal sources including gastrointestinal tract or gut. Arylalkylamine N-acetyltransferase (AANAT) is the key regulator of its biosynthesis. Melatonin in pineal is rhythmically produced with a nocturnal peak in synchronization with environmental light-dark cycle. A recent study on carp reported first that melatonin levels and intensity of a ~23 kDa AANAT protein in each gut segment also exhibit significant daily variations but, unlike pineal, show a peak at midday in all seasons. Extensive experimental studies ruled out direct role of light-dark conditions in determining temporal pattern of gut melatoninergic system in carp, and opened up possible role of environmental non-photic cue(s) as its synchronizer. Based on mammalian findings, physiological significance of gut-derived melatonin also appears unique because its actions at local levels sharing paracrine and/or autocrine functions have been emphasized. The purpose of this mini review is to summarize the existing data on the chronobiology and physiology of gut melatonin and to emphasize their relation with the same hormone derived in the pineal in vertebrates including fish.

  19. Mapping and Quantifying Terrestrial Vertebrate Biodiversity at ...

    Science.gov (United States)

    The ability to assess, report, map, and forecast functions of ecosystems is critical to our capacity to make informed decisions to maintain the sustainable nature of our environment. Because of the variability among living organisms and levels of organization (e.g. genetic, species, ecosystem), biodiversity has always been difficult to measure precisely, especially within a systematic manner and over multiple scales. In answer to this challenge, the U.S. Environmental Protection Agency has created a partnership with other Federal agencies, academic institutions, and Non-Governmental Organizations to develop the EnviroAtlas (https://www.epa.gov/enviroatlas), an online national Decision Support Tool that allows users to view and analyze the geographical description of the supply and demand for ecosystem services, as well as the drivers of change. As part of the EnviroAtlas, an approach has been developed that uses deductive habitat models for all terrestrial vertebrates of the conterminous United States and clusters them into biodiversity metrics that relate to ecosystem service-relevant categories. Metrics, such as species and taxon richness, have been developed and integrated with other measures of biodiversity. Collectively, these metrics provide a consistent scalable process from which to make geographic comparisons, provide thematic assessments, and to monitor status and trends in biodiversity. The national biodiversity component operates across approximatel

  20. Semaphorin signaling in vertebrate neural circuit assembly

    Directory of Open Access Journals (Sweden)

    Yutaka eYoshida

    2012-06-01

    Full Text Available Neural circuit formation requires the coordination of many complex developmental processes. First, neurons project axons over long distances to find their final targets and then establish appropriate connectivity essential for the formation of neuronal circuitry. Growth cones, the leading edges of axons, navigate by interacting with a variety of attractive and repulsive axon guidance cues along their trajectories and at final target regions. In addition to guidance of axons, neuronal polarization, neuronal migration and dendrite development must be precisely regulated during development to establish proper neural circuitry. Semaphorins consist of a large protein family, which includes secreted and cell surface proteins, and they play important roles in many steps of neural circuit formation. The major semaphorin receptors are plexins and neuropilins, however other receptors and co-receptors also mediate signaling by semaphorins. Upon semaphorin binding to their receptors, downstream signaling molecules transduce this event within cells to mediate further events, including alteration of microtubule and actin cytoskeletal dynamics. Here, I review recent studies on semaphorin signaling in vertebrate neural circuit assembly, with the goal of highlighting how this diverse family of cues and receptors imparts exquisite specificity to neural complex connectivity.

  1. Delayed coupling theory of vertebrate segmentation.

    Science.gov (United States)

    Morelli, Luis G; Ares, Saúl; Herrgen, Leah; Schröter, Christian; Jülicher, Frank; Oates, Andrew C

    2009-01-01

    Rhythmic and sequential subdivision of the elongating vertebrate embryonic body axis into morphological somites is controlled by an oscillating multicellular genetic network termed the segmentation clock. This clock operates in the presomitic mesoderm (PSM), generating dynamic stripe patterns of oscillatory gene-expression across the field of PSM cells. How these spatial patterns, the clock's collective period, and the underlying cellular-level interactions are related is not understood. A theory encompassing temporal and spatial domains of local and collective aspects of the system is essential to tackle these questions. Our delayed coupling theory achieves this by representing the PSM as an array of phase oscillators, combining four key elements: a frequency profile of oscillators slowing across the PSM; coupling between neighboring oscillators; delay in coupling; and a moving boundary describing embryonic axis elongation. This theory predicts that the segmentation clock's collective period depends on delayed coupling. We derive an expression for pattern wavelength across the PSM and show how this can be used to fit dynamic wildtype gene-expression patterns, revealing the quantitative values of parameters controlling spatial and temporal organization of the oscillators in the system. Our theory can be used to analyze experimental perturbations, thereby identifying roles of genes involved in segmentation.

  2. Animal Models of Parkinson's Disease: Vertebrate Genetics

    Science.gov (United States)

    Lee, Yunjong; Dawson, Valina L.; Dawson, Ted M.

    2012-01-01

    Parkinson's disease (PD) is a complex genetic disorder that is associated with environmental risk factors and aging. Vertebrate genetic models, especially mice, have aided the study of autosomal-dominant and autosomal-recessive PD. Mice are capable of showing a broad range of phenotypes and, coupled with their conserved genetic and anatomical structures, provide unparalleled molecular and pathological tools to model human disease. These models used in combination with aging and PD-associated toxins have expanded our understanding of PD pathogenesis. Attempts to refine PD animal models using conditional approaches have yielded in vivo nigrostriatal degeneration that is instructive in ordering pathogenic signaling and in developing therapeutic strategies to cure or halt the disease. Here, we provide an overview of the generation and characterization of transgenic and knockout mice used to study PD followed by a review of the molecular insights that have been gleaned from current PD mouse models. Finally, potential approaches to refine and improve current models are discussed. PMID:22960626

  3. Facultative parthenogenesis discovered in wild vertebrates

    Science.gov (United States)

    Booth, Warren; Smith, Charles F.; Eskridge, Pamela H.; Hoss, Shannon K.; Mendelson, Joseph R.; Schuett, Gordon W.

    2012-01-01

    Facultative parthenogenesis (FP)—asexual reproduction by bisexual species—has been documented in a variety of multi-cellular organisms but only recently in snakes, varanid lizards, birds and sharks. Unlike the approximately 80 taxa of unisexual reptiles, amphibians and fishes that exist in nature, FP has yet to be documented in the wild. Based on captive documentation, it appears that FP is widespread in squamate reptiles (snakes, lizards and amphisbaenians), and its occurrence in nature seems inevitable, yet the task of detecting FP in wild individuals has been deemed formidable. Here we show, using microsatellite DNA genotyping and litter characteristics, the first cases of FP in wild-collected pregnant females and their offspring of two closely related species of North American pitviper snakes—the copperhead (Agkistrodon contortrix) and cottonmouth (Agkistrodon piscivorus). Our findings support the view that non-hybrid origins of parthenogenesis, such as FP, are more common in squamates than previously thought. With this confirmation, FP can no longer be viewed as a rare curiosity outside the mainstream of vertebrate evolution. Future research on FP in squamate reptiles related to proximate control of induction, reproductive competence of parthenogens and population genetics modelling is warranted. PMID:22977071

  4. Ephaptic communication in the vertebrate retina

    Directory of Open Access Journals (Sweden)

    Rozan eVroman

    2013-09-01

    Full Text Available In the vertebrate retina, cones project to the horizontal cells (HCs and bipolar cells (BCs. The communication between cones and horizontal cells uses both chemical and ephaptic mechanisms. Photoreceptors release glutamate in a Ca2+-dependent manner, while HCs feed back to cones via an ephaptic mechanism. Hyperpolarization of HCs leads to an increased current through connexin hemichannels located on the tips of HC dendrites invaginating the cone synaptic terminals. This current makes the extracellular synaptic space slightly negative. The result is that the Ca2+-channels in the cone pre-synaptic membrane experience a slightly depolarized membrane potential and therefore more glutamate is released. This ephaptic mechanism forms a very fast and noise free negative feedback pathway. These characteristics are crucial, since the retina has to perform well in demanding conditions such as low light levels and detecting fast events. In this mini-review we will discuss the critical components of such an ephaptic mechanism. Furthermore, we will address the question whether such communication appears in other systems as well and indicate some fundamental features to look for when attempting to identify an ephaptic mechanism.

  5. Comparative analyses of bidirectional promoters in vertebrates

    Directory of Open Access Journals (Sweden)

    Taylor James

    2008-05-01

    Full Text Available Abstract Background Orthologous genes with deep phylogenetic histories are likely to retain similar regulatory features. In this report we utilize orthology assignments for pairs of genes co-regulated by bidirectional promoters to map the ancestral history of the promoter regions. Results Our mapping of bidirectional promoters from humans to fish shows that many such promoters emerged after the divergence of chickens and fish. Furthermore, annotations of promoters in deep phylogenies enable detection of missing data or assembly problems present in higher vertebrates. The functional importance of bidirectional promoters is indicated by selective pressure to maintain the arrangement of genes regulated by the promoter over long evolutionary time spans. Characteristics unique to bidirectional promoters are further elucidated using a technique for unsupervised classification, known as ESPERR. Conclusion Results of these analyses will aid in our understanding of the evolution of bidirectional promoters, including whether the regulation of two genes evolved as a consequence of their proximity or if function dictated their co-regulation.

  6. Microtubules, polarity and vertebrate neural tube morphogenesis.

    Science.gov (United States)

    Cearns, Michael D; Escuin, Sarah; Alexandre, Paula; Greene, Nicholas D E; Copp, Andrew J

    2016-07-01

    Microtubules (MTs) are key cellular components, long known to participate in morphogenetic events that shape the developing embryo. However, the links between the cellular functions of MTs, their effects on cell shape and polarity, and their role in large-scale morphogenesis remain poorly understood. Here, these relationships were examined with respect to two strategies for generating the vertebrate neural tube: bending and closure of the mammalian neural plate; and cavitation of the teleost neural rod. The latter process has been compared with 'secondary' neurulation that generates the caudal spinal cord in mammals. MTs align along the apico-basal axis of the mammalian neuroepithelium early in neural tube closure, participating functionally in interkinetic nuclear migration, which indirectly impacts on cell shape. Whether MTs play other functional roles in mammalian neurulation remains unclear. In the zebrafish, MTs are important for defining the neural rod midline prior to its cavitation, both by localizing apical proteins at the tissue midline and by orienting cell division through a mirror-symmetric MT apparatus that helps to further define the medial localization of apical polarity proteins. Par proteins have been implicated in centrosome positioning in neuroepithelia as well as in the control of polarized morphogenetic movements in the neural rod. Understanding of MT functions during early nervous system development has so far been limited, partly by techniques that fail to distinguish 'cause' from 'effect'. Future developments will likely rely on novel ways to selectively impair MT function in order to investigate the roles they play.

  7. Evolution of the Vertebrate Resistin Gene Family.

    Directory of Open Access Journals (Sweden)

    Qingda Hu

    Full Text Available Resistin (encoded by Retn was previously identified in rodents as a hormone associated with diabetes; however human resistin is instead linked to inflammation. Resistin is a member of a small gene family that includes the resistin-like peptides (encoded by Retnl genes in mammals. Genomic searches of available genome sequences of diverse vertebrates and phylogenetic analyses were conducted to determine the size and origin of the resistin-like gene family. Genes encoding peptides similar to resistin were found in Mammalia, Sauria, Amphibia, and Actinistia (coelacanth, a lobe-finned fish, but not in Aves or fish from Actinopterygii, Chondrichthyes, or Agnatha. Retnl originated by duplication and transposition from Retn on the early mammalian lineage after divergence of the platypus, but before the placental and marsupial mammal divergence. The resistin-like gene family illustrates an instance where the locus of origin of duplicated genes can be identified, with Retn continuing to reside at this location. Mammalian species typically have a single copy Retn gene, but are much more variable in their numbers of Retnl genes, ranging from 0 to 9. Since Retn is located at the locus of origin, thus likely retained the ancestral expression pattern, largely maintained its copy number, and did not display accelerated evolution, we suggest that it is more likely to have maintained an ancestral function, while Retnl, which transposed to a new location, displays accelerated evolution, and shows greater variability in gene number, including gene loss, likely evolved new, but potentially lineage-specific, functions.

  8. Gut Melatonin in Vertebrates: Chronobiology and Physiology

    Directory of Open Access Journals (Sweden)

    Dr. Saumen Kumar Maitra

    2015-07-01

    Full Text Available Melatonin, following discovery in the bovine pineal gland, has been detected in several extra-pineal sources including gastrointestinal tract or gut. Arylalkylamine N-acetyltransferase (AANAT is the key regulator of its biosynthesis. Melatonin in pineal is rhythmically produced with a nocturnal peak in synchronization with environmental light-dark cycle. A recent study on carp reported first that melatonin levels and intensity of a ~23kDa AANAT protein in each gut segment also exhibit significant daily variations but, unlike pineal, show a peak at midday in all seasons. Extensive experimental studies ruled out direct role of light-dark conditions in determining temporal pattern of gut melatoninergic system in carp, and opened up possible role of environmental non-photic cue(s as its synchronizer. Based on mammalian findings, physiological significance of gut derived melatonin also appears unique because its actions at local levels sharing paracrine and/or autocrine functions have been emphasized. The purpose of this mini-review is to summarize existing data on the chronobiology and physiology of gut melatonin and to emphasize their relation with the same hormone derived in the pineal in vertebrates including fish.

  9. Lumbo-costo-vertebral syndrome with posterior spinal dysraphism

    Directory of Open Access Journals (Sweden)

    Sujit Kumar G

    2005-01-01

    Full Text Available Lumbo-costo-vertebral syndrome, which includes abnormalities of the vertebral bodies, ribs and trunk musculature, is very rare and only few cases have been reported. We report a case of 18-month-old female child with absent ribs, hemivertebrae, superior lumbar hernia (features of lumbo-costo-vertebral syndrome and posterior spinal dysraphism, which to our knowledge is the first case in the English literature with such a combination of defects. Embryology and management of the case is discussed.

  10. Considerations on evolution and healing of vertebral fractures.

    Science.gov (United States)

    Klumpp, Raymond; Trevisan, Carlo; Nava, Veronica; Riccardi, Domenico; Recalcati, Wilmer

    2013-10-01

    Only little is known when talking about the evolution of a vertebral fracture. From the few studies available in the literature, we can deduce that the risk a vertebral compression fracture has to worsen its deformity is consistent. It is important to try to make a prognosis on how the fracture is going to heal based on the type of fracture encountered. A chapter of its own is the occurrence of a vertebral fracture non-union that is difficult to diagnose and treat, but comes along with a poor prognosis.

  11. Evolution of vertebrates as viewed from the crest.

    Science.gov (United States)

    Green, Stephen A; Simoes-Costa, Marcos; Bronner, Marianne E

    2015-04-23

    The origin of vertebrates was accompanied by the advent of a novel cell type: the neural crest. Emerging from the central nervous system, these cells migrate to diverse locations and differentiate into numerous derivatives. By coupling morphological and gene regulatory information from vertebrates and other chordates, we describe how addition of the neural-crest-specification program may have enabled cells at the neural plate border to acquire multipotency and migratory ability. Analysis of the topology of the neural crest gene regulatory network can serve as a useful template for understanding vertebrate evolution, including elaboration of neural crest derivatives.

  12. Climate change and the ecology and evolution of Arctic vertebrates

    DEFF Research Database (Denmark)

    Gilg, Olivier; Kovacs, Kit M.; Aars, J.

    2012-01-01

    Climate change is taking place more rapidly and severely in the Arctic than anywhere on the globe, exposing Arctic vertebrates to a host of impacts. Changes in the cryosphere dominate the physical changes that already affect these animals, but increasing air temperatures, changes in precipitation......, and ocean acidification will also affect Arctic ecosystems in the future. Adaptation via natural selection is problematic in such a rapidly changing environment. Adjustment via phenotypic plasticity is therefore likely to dominate Arctic vertebrate responses in the short term, and many such adjustments have...... immigration from the South, many Arctic vertebrates are expected to become increasingly threatened during this century....

  13. Advances in Vertebrate Paleontology and Paleoanthropology in China

    Institute of Scientific and Technical Information of China (English)

    ZHOU Zhonghe; WANG Yuanqing

    2010-01-01

    @@ Vertebrate paleontology and paleoanthropology in China have a long glorious history dating back to the 1920s,and significant progress has been made in the last twenty years thanks to the discoveries of hundreds of important vertebrate fossils from the deposits ranging in age from the Early Cambrian to the Quaternary.These discoveries have led to nearly 100 papers appearing in prestigious journals of Nature,Science and PARAS by Chinese vertebrate paleontologists and paleoanthropologists,outnumbering those published by Chinese scientists from any other discipline in the same period.

  14. VERTEBRAL DEFORMITY IN CHILDREN AND DISPENSARY CARE ORGANIZATION

    Directory of Open Access Journals (Sweden)

    I. T. Batrshin

    2011-01-01

    Full Text Available In order to analyze the prevalence of spine deformation pathology and the state of vertebral children care screening of 18 500 schoolchildren was conducted by computer optical topography. In 79.5% of them the posture disturbances and in 14.5% - spinal deformity were detected. The multivariate analysis of vertebral deformity was performed. It is established that vertebral deformity till 10° on Coob has usually monoplane form, and more than 10° - only multiplane form. Dispensary health groups were formed, screening program for children with subsequent monitoring was proposed.

  15. Trunk muscle activity is modified in osteoporotic vertebral fracture and thoracic kyphosis with potential consequences for vertebral health.

    Directory of Open Access Journals (Sweden)

    Alison M Greig

    Full Text Available This study explored inter-relationships between vertebral fracture, thoracic kyphosis and trunk muscle control in elderly people with osteoporosis. Osteoporotic vertebral fractures are associated with increased risk of further vertebral fractures; but underlying mechanisms remain unclear. Several factors may explain this association, including changes in postural alignment (thoracic kyphosis and altered trunk muscle contraction patterns. Both factors may increase risk of further fracture because of increased vertebral loading and impaired balance, which may increase falls risk. This study compared postural adjustments in 24 individuals with osteoporosis with and without vertebral fracture and with varying degrees of thoracic kyphosis. Trunk muscle electromyographic activity (EMG associated with voluntary arm movements was recorded and compared between individuals with and without vertebral fracture, and between those with low and high thoracic kyphosis. Overall, elderly participants in the study demonstrated co-contraction of the trunk flexor and extensor muscles during forwards arm movements, but those with vertebral fractures demonstrated a more pronounced co-contraction than those without fracture. Individuals with high thoracic kyphosis demonstrated more pronounced alternating flexor and extensor EMG bursts than those with less kyphosis. Co-contraction of trunk flexor and extensor muscles in older individuals contrasts the alternating bursts of antagonist muscle activity in previous studies of young individuals. This may have several consequences, including altered balance efficacy and the potential for increased compressive loads through the spine. Both of these outcomes may have consequences in a population with fragile vertebrae who are susceptible to fracture.

  16. Diagnosis of vertebral fractures on lateral chest X-ray: Intraobserver agreement of semi-quantitative vertebral fracture assessment

    Energy Technology Data Exchange (ETDEWEB)

    Jagt-Willems, H.C. van der, E-mail: Hvanderjagt@spaarneziekenhuis.nl [Department of Geriatrics, Slotervaart Hospital, Amsterdam (Netherlands); Department of Internal Medicine, Spaarne Hospital, Hoofddorp (Netherlands); Munster, B.C. van [Department of Internal Medicine, Academic Medical Center, Amsterdam (Netherlands); Department of Geriatrics, Gelre Hospitals, Apeldoorn (Netherlands); Leeflang, M. [Department of Geriatrics, Gelre Hospitals, Apeldoorn (Netherlands); Beuerle, E. [Department of Radiology, Slotervaart Hospital, Amsterdam (Netherlands); Tulner, C.R. [Department of Geriatrics, Slotervaart Hospital, Amsterdam (Netherlands); Lems, W.F. [Department of Rheumatology, VU Medical Center, Amsterdam (Netherlands)

    2014-12-15

    Highlights: • (Lateral) chest X-ray's are often performed in older individuals for various reasons. • Vertebral fractures are visualized on lateral chest X-ray, but the diagnosis of vertebral fractures is until now only validated on (lateral) spine X-ray's. • This study shows that a (lateral) chest X-ray is sufficient for the diagnosis of vertebral fractures. • Older individuals with a vertebral fracture on a (lateral) chest X-ray do not need further radiography with thoracic spine X-ray or vertebral fracture assessment with DXA. - Abstract: Background: In clinical practice lateral images of the chest are performed for various reasons. As these lateral chest X rays show the vertebrae of the thoracic and thoraco-lumbar region, we wondered if these X-rays can be used for evaluation of vertebral fractures instead of separate thoracic spine X-rays. Methods: To evaluate the agreement and intraobserver reliability of the semi-quantitative method for vertebral fractures on the lateral chest X-ray (X-chest) in comparison to the lateral thoracic spine X-ray (X-Tspine), two observers scored vertebral fractures on X-Tspine and twice on X-chest, separately, blinded and in different time periods. Agreement and Cohens’ kappa were calculated for a diagnosis of any fracture on patient level and on vertebral body level. The study was done in patients visiting an outpatient geriatric day clinic, with a high prevalence of vertebral fractures. Results: 109 patients were included. The intraobserver agreement for X-chest versus X-Tspine was 95–98% for the two levels of fracturing, with a Cohen's kappa of 0.88–0.91. The intraobserver agreement and reliability of the re-test on the X-chest showed an agreement between 91 and 98% with a Cohen's kappa of 0.81–0.93. More vertebrae were visible on the X-chest, mean 10.2, SD 0.66 versus mean 9.8, SD 0.73 on the X-Tspine (p < 0.001). Conclusion: The results show good agreement and intraobserver reliability on

  17. Associations between the Cervical Vertebral Column and Craniofacial Morphology

    Directory of Open Access Journals (Sweden)

    L. Sonnesen

    2010-01-01

    Conclusion. It is suggested that fusion of the cervical vertebral column is associated with development and function of the craniofacial morphology. This finding is expected to have importance for diagnostics and elucidation of aetiology and thereby for optimal treatment.

  18. A novel form of ischio-vertebral syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Kassi, Ali A.; Ghachem, Maher B. [Hopital des Enfants Malades, Department of Orthopaedics, Tunis (Tunisia); Chehida, Farid B.; Gharbi, Hassan; Hendaoui, Lofti [Hopital des Enfants Malades, Department of Radiology, Tunis (Tunisia); Latos-Bielenska, Anna [University of Medical Sciences, Department of Medical Genetics, Poznan (Poland); Kozlowski, Kazimierz [New Children' s Hospital, Department of Medical Imaging, Sydney (Australia); The Children' s Hospital at Westmead, Sydney, NSW (Australia)

    2007-01-15

    We report a boy with ischial hypoplasia, vertebral malsegmentation and multiple other skeletal anomalies which do not fit well with any previously-described disorder. The proband's brother and mother were also slightly affected. We review the pertinent literature, discuss the differential diagnosis and suggest that this may be a previously unreported autosomal dominant disorder, with variable penetrance.We believe that the clinical and radiological features of various syndromes with ischial aplasia/hypoplasia and vertebral malsegmentation are not sufficiently different to justify the current separate categories of ''ischio-vertebral dysplasia'' and ''ischio-spinal dysostosis''. We suggest that the term ''ischio-vertebral syndrome'' should be used until identification of genes affecting ischial and axial morphogenesis is completed. (orig.)

  19. Experiment K307: Vertebral body strength of rat spinal columns

    Science.gov (United States)

    Kazarian, L. E.

    1981-01-01

    The effects of space flight on vertebral body bone strength excised were investigated. Comparative biomechanical investigations of vertebral body strength for flight, synchronous, and vivarium rats following spacecraft recovery (R+0), at R+6 and R+29 days post flight recovery are presented. Statistical analyses are presented for the mechanical properties of stiffness, ultimate load, displacement to ultimate load, and energy to ultimate load. At R+0 all of the above properties show that the vertebral body exhibits an increasing susceptibility to fracture. The reduction of bone strength is inhomogeneous and dependent on vertebral level. The R+6 recovery data was inconclusive since it varied above and below the R+0 data. At R+29 ultimate load values showed a statistically significant increase in bone strength approaching that of the vivarium or control group.

  20. Modified posterior vertebral column resection for Kümmell disease

    Science.gov (United States)

    Liu, Feng-Yu; Huo, Li-Shuang; Liu, Sen; Wang, Hui; Zhang, Li-Jun; Yang, Da-Long; Ding, Wen-Yuan

    2017-01-01

    Abstract Rationale: Kümmell's disease is defined as delayed traumatic vertebral collapse disease in which patients develop a kyphosis after asymptomatic minor spinal trauma. Both anterior approach and posterior approach have been reported, however, there is no standard treatment for Kümmell's disease. Patient concerns: We described a successful modified posterior vertebral column resection in a patient with Kümmell's disease. A 65-year-old woman reported persistent back pain for almost three months. Diagnoses: Kümmell's disease was diagnosed based on computer tomography (CT) and magnetic resonance imaging (MRI). Interventions: Modified posterior vertebral column resection combined with short-segment fixation was designed to treat this disease. Outcomes: The procedure was successful without any complications. Patient reported that symptoms were obviously improved in one week after operation. Lessons: Modified posterior vertebral column resection combined with short-segment fixation is an effective treatment option for Kümmell's disease. PMID:28151882

  1. An interesting case report of vertebral artery dissection following polytrauma

    Directory of Open Access Journals (Sweden)

    Vikas Acharya

    2016-01-01

    Conclusion: Our report displays select images related to this case report and emphasizes the consideration of routine imaging in head and neck traumatic injuries to diagnose internal carotid and/or vertebral artery dissections much earlier.

  2. MR manifestations of vertebral artery injuries in cervical spine trauma

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Jeong Sik; Chung, Tae Sub; Kim, Young Soo; Cho, Yong Eun; Kang, Byung Chul; Kim, Dong Ik [Yonsei Univ. College of Medicine, Seoul (Korea, Republic of)

    1996-11-01

    To assess the diagnostic efficacy of magnetic resonance (MR) imaging in the detection of a vertebral artery injury occurring from major cervical spine trauma. Conventional MR findings of 63 patients and 63 control subjects were compared to detect a possible change in the vertebral arteries resulted from trauma. Plain films, CT and clinical records were also reviewed to correlate the degree of cervical spine injury with vascular change. Nine cases of absent flow signals in vessel lumen were observed in eight patients and one was observed in the control group. Patients more frequently demonstrated other abnormalities such as intraluminal linear signals (n=3) or focal luminal narrowing (n=9) but there was no statistical significance. There was a close relationship between degree of cord damage and occlusion of the vertebral artery. Conventional MR imaging is useful in the detection of vertebral artery occlusion resulting from cervical spine trauma.

  3. Associations between the Cervical Vertebral Column and Craniofacial Morphology

    DEFF Research Database (Denmark)

    Sonnesen, Ane Liselotte

    2010-01-01

    Aim. To summarize recent studies on morphological deviations of the cervical vertebral column and associations with craniofacial morphology and head posture in nonsyndromic patients and in patients with obstructive sleep apnoea (OSA). Design. In these recent studies, visual assessment of the cerv......Aim. To summarize recent studies on morphological deviations of the cervical vertebral column and associations with craniofacial morphology and head posture in nonsyndromic patients and in patients with obstructive sleep apnoea (OSA). Design. In these recent studies, visual assessment...... of the cervical vertebral column and cephalometric analysis of the craniofacial skeleton were performed on profile radiographs of subjects with neutral occlusion, patients with severe skeletal malocclusions and patients with OSA. Material from human triploid foetuses and mouse embryos was analysed histologically....... Results. Recent studies have documented associations between fusion of the cervical vertebral column and craniofacial morphology, including head posture in patients with severe skeletal malocclusions. Histological studies on prenatal material supported these findings. Conclusion. It is suggested...

  4. Complete posterior migration of intact vertebral body in spinal tuberculosis

    Directory of Open Access Journals (Sweden)

    Sridhar Krishnamurthy

    2009-01-01

    Full Text Available Spinal tuberculosis most commonly presents as a paradiscal lesion involving the disc space and adjacent vertebral bodies. Atypical forms of spinal tuberculosis have been described and are most often a result of posterior element involvement. The authors report a patient, who presented with complete posterior migration of an intact vertebral body, a complication of spinal tuberculosis that has not been reported till date. A 12-year-old girl with history of pulmonary tuberculosis presented with progressive paraparesis and back pain. Plain X-rays and MRI revealed that the L2 vertebral body had migrated posteriorly into the spinal canal, without significant movement of the posterior elements. The vertebral body was normal, with no erosion or bone loss. However, bilateral pedicle and facet joint involvement was seen. The neural elements were decompressed through an anterolateral retroperitoneal approach and the spine reconstructed. The authors present this rare manifestation of spinal tuberculosis and discuss the possible mechanisms of this presentation.

  5. Treatment of osteoporotic vertebral body compression fractures by percutaneous vertebroplasty

    Institute of Scientific and Technical Information of China (English)

    Hongmin Zang; Yiheng Liu; Junchang Chen

    2005-01-01

    Objective: To explore the effect of percutaneous vertebroplasty to treat osteoporotic vertebral body compression fractures. Methods: Seventeen patients with compression fractures at 27 different levels came in for percutaneous vertebroplasty. Under the guidance of C-arm image intensifier, bone needle was inserted into the fracture vertebral bodies via a unilateral transpedicular approach.Polymethyl methacrylate (PMMA) was injected slowly under continuous fluoroscopic control. Then the effect was evaluated after operation.Results: Follow-up results among 15 patients were studied, other two patients lost contact. The follow-up period was from three to seven months. No patient had relapse of compression fracture. Leakage of the cement outside the vertebral body was seen in four bodies. All patients had a complete relief after Percutaneous vertebroplasty(PVP). Conclusion: PVP is an efficient minimally invasive technique to treat osteoporotic vertebral body compression fractures.

  6. Do Vertebrate Gut Metagenomes Confer Rapid Ecological Adaptation?

    Science.gov (United States)

    Alberdi, Antton; Aizpurua, Ostaizka; Bohmann, Kristine; Zepeda-Mendoza, Marie Lisandra; Gilbert, M Thomas P

    2016-09-01

    During times of rapid environmental change, survival of most vertebrate populations depends on their phenomic plasticity. Although differential gene-expression and post-transcriptional processes of the host genome receive focus as the main molecular mechanisms, growing evidence points to the gut microbiota as a key driver defining hosts' phenotypes. We propose that the plasticity of the gut microbiota might be an essential factor determining phenomic plasticity of vertebrates, and that it might play a pivotal role when vertebrates acclimate and adapt to fast environmental variation. We contemplate some key questions and suggest methodological approaches and experimental designs that can be used to evaluate whether gut microorganisms provide a boost of plasticity to vertebrates' phenomes, thereby increasing their acclimation and adaptation capacity.

  7. Anatomical variation of the origin of the left vertebral artery

    Directory of Open Access Journals (Sweden)

    Patasi B

    2009-08-01

    Full Text Available This paper presents and describes the anatomical variation of the left vertebral artery originating from the arch of aorta as a case report. This variation was found in one of the cadavers at the Division of Clinical and Functional Anatomy, Faculty of Medicine, University of Ottawa. During routine dissection of a male cadaver, in the superior mediastinum and the neck we observed an atypical origin of the left vertebral artery. Atypical origin was compared to the typical origin of the left vertebral artery in the anatomical literature. We compared our findings with different possible variations of the origin of the left vertebral artery reported in the literature. The clinical importance of the variation is discussed.

  8. Clinical Differences Between Monomicrobial and Polymicrobial Vertebral Osteomyelitis.

    Science.gov (United States)

    Issa, Kimona; Pourtaheri, Sina; Stewart, Tyler; Faloon, Michael; Sahai, Nikhil; Mease, Samuel; Sinha, Kumar; Hwang, Ki; Emami, Arash

    2016-11-11

    Little literature exists examining differences in presentation and outcomes between monomicrobial and polymicrobial vertebral infections. Seventy-nine patients treated for vertebral osteomyelitis between 2001 and 2011 were reviewed. Patients were divided into monomicrobial and polymicrobial cohorts based on type of infection. Various characteristics were compared between the 2 groups. The 26 patients with a polymicrobial infection were older and had a higher mortality rate, lower clearance of infection, larger infection, more vertebral instability, higher erythrocyte sedimentation rate at presentation, and longer mean length of stay. There were no significant differences in Oswestry Disability Index scores at final follow-up, but there were differences in presentation and clinical outcomes between monomicrobial and polymicrobial vertebral osteomyelitis. Patients may benefit from counseling regarding their disease type and potential prognosis. [Orthopedics. 201x; xx(x):xx-xx.].

  9. Design principles of insect and vertebrate visual systems.

    Science.gov (United States)

    Sanes, Joshua R; Zipursky, S Lawrence

    2010-04-15

    A century ago, Cajal noted striking similarities between the neural circuits that underlie vision in vertebrates and flies. Over the past few decades, structural and functional studies have provided strong support for Cajal's view. In parallel, genetic studies have revealed some common molecular mechanisms controlling development of vertebrate and fly visual systems and suggested that they share a common evolutionary origin. Here, we review these shared features, focusing on the first several layers-retina, optic tectum (superior colliculus), and lateral geniculate nucleus in vertebrates; and retina, lamina, and medulla in fly. We argue that vertebrate and fly visual circuits utilize common design principles and that taking advantage of this phylogenetic conservation will speed progress in elucidating both functional strategies and developmental mechanisms, as has already occurred in other areas of neurobiology ranging from electrical signaling and synaptic plasticity to neurogenesis and axon guidance.

  10. The 'Tully monster' is a vertebrate.

    Science.gov (United States)

    McCoy, Victoria E; Saupe, Erin E; Lamsdell, James C; Tarhan, Lidya G; McMahon, Sean; Lidgard, Scott; Mayer, Paul; Whalen, Christopher D; Soriano, Carmen; Finney, Lydia; Vogt, Stefan; Clark, Elizabeth G; Anderson, Ross P; Petermann, Holger; Locatelli, Emma R; Briggs, Derek E G

    2016-04-28

    Problematic fossils, extinct taxa of enigmatic morphology that cannot be assigned to a known major group, were once a major issue in palaeontology. A long-favoured solution to the 'problem of the problematica', particularly the 'weird wonders' of the Cambrian Burgess Shale, was to consider them representatives of extinct phyla. A combination of new evidence and modern approaches to phylogenetic analysis has now resolved the affinities of most of these forms. Perhaps the most notable exception is Tullimonstrum gregarium, popularly known as the Tully monster, a large soft-bodied organism from the late Carboniferous Mazon Creek biota (approximately 309-307 million years ago) of Illinois, USA, which was designated the official state fossil of Illinois in 1989. Its phylogenetic position has remained uncertain and it has been compared with nemerteans, polychaetes, gastropods, conodonts, and the stem arthropod Opabinia. Here we review the morphology of Tullimonstrum based on an analysis of more than 1,200 specimens. We find that the anterior proboscis ends in a buccal apparatus containing teeth, the eyes project laterally on a long rigid bar, and the elongate segmented body bears a caudal fin with dorsal and ventral lobes. We describe new evidence for a notochord, cartilaginous arcualia, gill pouches, articulations within the proboscis, and multiple tooth rows adjacent to the mouth. This combination of characters, supported by phylogenetic analysis, identifies Tullimonstrum as a vertebrate, and places it on the stem lineage to lampreys (Petromyzontida). In addition to increasing the known morphological disparity of extinct lampreys, a chordate affinity for T. gregarium resolves the nature of a soft-bodied fossil which has been debated for more than 50 years.

  11. Opportunities and costs for preventing vertebrate extinctions.

    Science.gov (United States)

    Conde, Dalia A; Colchero, Fernando; Güneralp, Burak; Gusset, Markus; Skolnik, Ben; Parr, Michael; Byers, Onnie; Johnson, Kevin; Young, Glyn; Flesness, Nate; Possingham, Hugh; Fa, John E

    2015-03-16

    Despite an increase in policy and management responses to the global biodiversity crisis, implementation of the 20 Aichi Biodiversity Targets still shows insufficient progress [1]. These targets, strategic goals defined by the United Nations Convention on Biological Diversity (CBD), address major causes of biodiversity loss in part by establishing protected areas (Target 11) and preventing species extinctions (Target 12). To achieve this, increased interventions will be required for a large number of sites and species. The Alliance for Zero Extinction (AZE) [2], a consortium of conservation-oriented organisations that aims to protect Critically Endangered and Endangered species restricted to single sites, has identified 920 species of mammals, birds, amphibians, reptiles, conifers and reef-building corals in 588 'trigger' sites [3]. These are arguably the most irreplaceable category of important biodiversity conservation sites. Protected area coverage of AZE sites is a key indicator of progress towards Target 11 [1]. Moreover, effective conservation of AZE sites is essential to achieve Target 12, as the loss of any of these sites would certainly result in the global extinction of at least one species [2]. However, averting human-induced species extinctions within AZE sites requires enhanced planning tools to increase the chances of success [3]. Here, we assess the potential for ensuring the long-term conservation of AZE vertebrate species (157 mammals, 165 birds, 17 reptiles and 502 amphibians) by calculating a conservation opportunity index (COI) for each species. The COI encompasses a set of measurable indicators that quantify the possibility of achieving successful conservation of a species in its natural habitat (COIh) and by establishing insurance populations in zoos (COIc).

  12. Predicting chemical impacts on vertebrate endocrine systems.

    Science.gov (United States)

    Nichols, John W; Breen, Miyuki; Denver, Robert J; Distefano, Joseph J; Edwards, Jeremy S; Hoke, Robert A; Volz, David C; Zhang, Xiaowei

    2011-01-01

    Animals have evolved diverse protective mechanisms for responding to toxic chemicals of both natural and anthropogenic origin. From a governmental regulatory perspective, these protective responses complicate efforts to establish acceptable levels of chemical exposure. To explore this issue, we considered vertebrate endocrine systems as potential targets for environmental contaminants. Using the hypothalamic-pituitary-thyroid (HPT), hypothalamic-pituitary-gonad (HPG), and hypothalamic-pituitary-adrenal (HPA) axes as case examples, we identified features of these systems that allow them to accommodate and recover from chemical insults. In doing so, a distinction was made between effects on adults and those on developing organisms. This distinction was required because endocrine system disruption in early life stages may alter development of organs and organ systems, resulting in permanent changes in phenotypic expression later in life. Risk assessments of chemicals that impact highly regulated systems must consider the dynamics of these systems in relation to complex environmental exposures. A largely unanswered question is whether successful accommodation to a toxic insult exerts a fitness cost on individual animals, resulting in adverse consequences for populations. Mechanistically based mathematical models of endocrine systems provide a means for better understanding accommodation and recovery. In the short term, these models can be used to design experiments and interpret study findings. Over the long term, a set of validated models could be used to extrapolate limited in vitro and in vivo testing data to a broader range of untested chemicals, species, and exposure scenarios. With appropriate modification, Tier 2 assays developed in support of the U.S. Environmental Protection Agency's Endocrine Disruptor Screening Program could be used to assess the potential for accommodation and recovery and inform the development of mechanistically based models.

  13. Computerized tomography of the vertebral column and the vertebral canal. Computertomographie der Wirbelsaeule und des Spinalkanals

    Energy Technology Data Exchange (ETDEWEB)

    Thurn, P.; Friedmann, G.

    1983-01-01

    Soon after the introduction of whole-body computerized tomography, it became apparent that this method is a valuable aid in many clinical problems as especially the paravertebral soft parts can be satisfactorily evaluated. The further technical improvement of the devices to permit sectoral and thin-layer scans, provided the possibility of scanning especially the intraspinal structures with an accuracy not so far known. Thus it became for the first time possible to demonstrate details of the spinal cord, the cauda and the surrounding spinal meninges directly, making for quite a substantial improvement of differential diagnosis and the restriction of myelography, which remains an invasive method despite the use of water-soluble contrast media. As the limitations and possibilities of the method have meanwhile been definitely established to some extent, the results in cases of intervertebral disk lesions, tumors, malformations, traumata and other diseases, which are based on the evaluation of some 3,000 examinations, were compiled in the hope of providing a manual to those concerned with computerized tomography of the vertebrate column and the vertebral canal, making them familiar with the normal anatomy and the interpretation of images of pathologic conditions, and pointing out the efficiency of computerized tomography in this particular sector of X-ray diagnostics.

  14. Vertebrate Paleontology in Central America: 30 years of progress

    OpenAIRE

    2014-01-01

    Vertebrate paleontology began in Central America in 1858 with the first published records, but the last 30 years have seen remarkable advances. These advances range from new localities, to new taxa to new analyses of diverse data. Central American vertebrate fossils represent all of the major taxonomic groups of vertebrates—fishes, amphibians, reptiles (especially turtles), birds and mammals (mostly xenarthrans, carnivores and ungulates)—but coverage is very uneven, with many groups (especial...

  15. [Complex forms of behavior in a series of vertebrates].

    Science.gov (United States)

    Maliukova, I V

    1978-01-01

    Within evolutionary line of vertebrates, correlation between the degree of differentiation of the brain and peculiarities of the formation of complex behavioural acts may be observed. Gradual evolution in the organization of complex motor food-searching conditioned reflexes and the capacity to visual discrimination was revealed in phylogenetic line of vertebrates: elasmobranchs (rays and sharks), marine teleosts, reptiles (terrestrial tortoises), insectivores (hedgehogs), rodents (rats) and primates (lower monkeys).

  16. Endovascular treatment for bilateral vertebral arteriovenous fistulas in neurofibromatosis 1.

    Science.gov (United States)

    Siddhartha, W; Chavhan, Govind B; Shrivastava, Manish; Limaye, Uday S

    2003-12-01

    We report a rare case of a 36-year-old woman with neurofibromatosis 1 (NF1) with bilateral vertebro-vertebral arteriovenous fistulas. The patient presented with quadriparesis and had neck pain. Angiography revealed vertebral arteriovenous fistulas bilaterally with dilated epidural venous plexuses compressing the cervical cord resulting in quadriparesis. Endovascular treatment using coils and balloons resulted in successful occlusion of both fistulas. At 6-months postembolization, the patient had improved significantly and is now able to walk with support.

  17. Use of cervical vertebral dimensions for assessment of children growth

    Directory of Open Access Journals (Sweden)

    Maria de Paula Caldas

    2007-04-01

    Full Text Available OBJECTIVE: The purpose of this study was to investigate whether skeletal maturation using cephalometric radiographs could be used in a Brazilian population. MATERIAL AND METHODS: The study population was selected from the files of the Oral Radiological Clinic of the Dental School of Piracicaba, Brazil and consisted of 128 girls and 110 boys (7.0 to 15.9 years old who had cephalometric and hand-wrist radiographs taken on the same day. Cervical vertebral bone age was evaluated using the method described by Mito and colleagues in 2002. Bone age was assessed by the Tanner-Whitehouse (TW3 method and was used as a gold standard to determine the reliability of cervical vertebral bone age. An analysis of variance and Tukey's post-hoc test were used to compare cervical vertebral bone age, bone age and chronological age at 5% significance level. RESULTS: The analysis of the Brazilian female children data showed that there was a statistically significant difference (p0.05 was found between cervical vertebral bone age and bone age. Differently, the analysis of the male children data revealed a statistically significant difference (p<0.05 between cervical vertebral bone age and bone age and between cervical vertebral bone age and chronological age (p<0.05. CONCLUSIONS: The findings of the present study suggest that the method for objectively evaluating skeletal maturation on cephalometric radiographs by determination of vertebral bone age can be applied to Brazilian females only. The development of a new method to objectively evaluate cervical vertebral bone age in males is needed.

  18. Associations between the Cervical Vertebral Column and Craniofacial Morphology

    OpenAIRE

    Sonnesen, L.

    2010-01-01

    Aim. To summarize recent studies on morphological deviations of the cervical vertebral column and associations with craniofacial morphology and head posture in nonsyndromic patients and in patients with obstructive sleep apnoea (OSA). Design. In these recent studies, visual assessment of the cervical vertebral column and cephalometric analysis of the craniofacial skeleton were performed on profile radiographs of subjects with neutral occlusion, patients with severe skeletal malocclusions a...

  19. Prevalence of thoracolumbar vertebral fractures on multidetector CT

    Energy Technology Data Exchange (ETDEWEB)

    Bartalena, Tommaso [Department of Radiology, S. Orsola University Hospital, Via Massarenti 9 - 40138 Bologna (Italy)], E-mail: t.bartalena@email.it; Giannelli, Giovanni; Rinaldi, Maria Francesca [Department of Radiology, S. Orsola University Hospital, Via Massarenti 9 - 40138 Bologna (Italy); Rimondi, Eugenio [Department of Radiology, Rizzoli Orthopaedic Institute, Via G.C. Pupilli 1 - 40136 Bologna (Italy); Rinaldi, Giovanni [Department of Radiology, S. Orsola University Hospital, Via Massarenti 9 - 40138 Bologna (Italy); Sverzellati, Nicola [Department of Clinical Sciences, Section of Radiology, University of Parma, Via Gramsci, 14 - 43100 Parma (Italy); Gavelli, Giampaolo [Department of Radiology, S. Orsola University Hospital, Via Massarenti 9 - 40138 Bologna (Italy)

    2009-03-15

    Objective: To evaluate the prevalence of osteoporotic vertebral fractures in patients undergoing multidetector computed tomography (MDCT) of the chest and/or abdomen. Materials and methods: 323 consecutive patients (196 males, 127 females) with a mean age of 62.6 years (range 20-88) who had undergone chest and/or abdominal MDCT were evaluated. Sagittal reformats of the spine obtained from thin section datasets were reviewed by two radiologists and assessed for vertebral fractures. Morphometric analysis using electronic calipers was performed on vertebral bodies which appeared abnormal upon visual inspection. A vertebral body height loss of 15% or more was considered a fracture and graded as mild (15-24%), moderate (25-49%) or severe (more than 50%). Official radiology reports were reviewed and whether the vertebral fractures had been reported or not was noted. Results: 31 out of 323 patients (9.5%) had at least 1 vertebral fracture and 7 of those patients had multiple fractures for a total of 41 fractures. Morphometric grading revealed 10 mild, 16 moderate and 15 severe fractures. Prevalence was higher in women (14.1%) than men (6.6%) and increased with patients age with a 17.1% prevalence in post-menopausal women. Only 6 out 41 vertebral fractures (14.6%) had been noted in the radiology final report while the remaining 35 (85.45) had not. Conclusion: although vertebral fractures represent frequent incidental findings on multidetector CT studies and may be easily identified on sagittal reformats, they are often underreported by radiologists, most likely because of unawareness of their clinical importance.

  20. Programming and inheritance of parental DNA methylomes in vertebrates.

    Science.gov (United States)

    Ci, Weimin; Liu, Jiang

    2015-01-01

    5-Methylcytosine (5mC) is a major epigenetic modification in animals. The programming and inheritance of parental DNA methylomes ensures the compatibility for totipotency and embryonic development. In vertebrates, the DNA methylomes of sperm and oocyte are significantly different. During early embryogenesis, the paternal and maternal methylomes will reset to the same state. Herein, we focus on recent advances in how offspring obtain the DNA methylation information from parents in vertebrates.

  1. Persistence, entrainment, and function of circadian rhythms in polar vertebrates.

    Science.gov (United States)

    Williams, Cory T; Barnes, Brian M; Buck, C Loren

    2015-03-01

    Polar organisms must cope with an environment that periodically lacks the strongest time-giver, or zeitgeber, of circadian organization-robust, cyclical oscillations between light and darkness. We review the factors influencing the persistence of circadian rhythms in polar vertebrates when the light-dark cycle is absent, the likely mechanisms of entrainment that allow some polar vertebrates to remain synchronized with geophysical time, and the adaptive function of maintaining circadian rhythms in such environments.

  2. From cyst to tubule: innovations in vertebrate spermatogenesis

    OpenAIRE

    Yoshida, Shosei

    2015-01-01

    Although vertebrates share many common traits, their germline development and function exhibit significant divergence. In particular, this article focuses on their spermatogenesis. The fundamental elements that constitute vertebrate spermatogenesis and the evolutionary changes that occurred upon transition from water to land will be discussed. The life‐long continuity of spermatogenesis is supported by the function of stem cells. Series of mitotic and meiotic germ cell divisions are ‘incomple...

  3. Evolutionary history of the vertebrate mitogen activated protein kinases family.

    Directory of Open Access Journals (Sweden)

    Meng Li

    Full Text Available BACKGROUND: The mitogen activated protein kinases (MAPK family pathway is implicated in diverse cellular processes and pathways essential to most organisms. Its evolution is conserved throughout the eukaryotic kingdoms. However, the detailed evolutionary history of the vertebrate MAPK family is largely unclear. METHODOLOGY/PRINCIPAL FINDINGS: The MAPK family members were collected from literatures or by searching the genomes of several vertebrates and invertebrates with the known MAPK sequences as queries. We found that vertebrates had significantly more MAPK family members than invertebrates, and the vertebrate MAPK family originated from 3 progenitors, suggesting that a burst of gene duplication events had occurred after the divergence of vertebrates from invertebrates. Conservation of evolutionary synteny was observed in the vertebrate MAPK subfamilies 4, 6, 7, and 11 to 14. Based on synteny and phylogenetic relationships, MAPK12 appeared to have arisen from a tandem duplication of MAPK11 and the MAPK13-MAPK14 gene unit was from a segmental duplication of the MAPK11-MAPK12 gene unit. Adaptive evolution analyses reveal that purifying selection drove the evolution of MAPK family, implying strong functional constraints of MAPK genes. Intriguingly, however, intron losses were specifically observed in the MAPK4 and MAPK7 genes, but not in their flanking genes, during the evolution from teleosts to amphibians and mammals. The specific occurrence of intron losses in the MAPK4 and MAPK7 subfamilies might be associated with adaptive evolution of the vertebrates by enhancing the gene expression level of both MAPK genes. CONCLUSIONS/SIGNIFICANCE: These results provide valuable insight into the evolutionary history of the vertebrate MAPK family.

  4. Anatomical variation of the origin of the left vertebral artery

    OpenAIRE

    Patasi B; Yeung A; Goodwin S; Jalali A

    2009-01-01

    This paper presents and describes the anatomical variation of the left vertebral artery originating from the arch of aorta as a case report. This variation was found in one of the cadavers at the Division of Clinical and Functional Anatomy, Faculty of Medicine, University of Ottawa. During routine dissection of a male cadaver, in the superior mediastinum and the neck we observed an atypical origin of the left vertebral artery. Atypical origin was compared to the typical origin of the left ver...

  5. Analysis of functional CT scan in cervical vertebral disease

    Energy Technology Data Exchange (ETDEWEB)

    Hirofuji, Eiichi; Tanaka, Seisuke; Tomihara, Mitsuo; Kita, Hiroshi; Yamasaki, Hiroyuki

    1982-12-01

    The atlantoaxial joint showed displacement in various directions in rheumatoid arthritis and cervical spondylosis. The displacements were promoted by anterior flexion and rotatory movements, exerting great influences on the spnial cord. The intervertebral space between the 5th and 6th vertebra showed narrowing of the vertebral canal in cervical spondylosis and was promoted by posterior flexion to affect the spinal cord to a great extent. Functional CT scan was useful for observation of pathologic conditions of vertebral diseases.

  6. A central role for the notochord in vertebral patterning.

    Science.gov (United States)

    Fleming, Angeleen; Keynes, Roger; Tannahill, David

    2004-02-01

    The vertebrates are defined by their segmented vertebral column, and vertebral periodicity is thought to originate from embryonic segments, the somites. According to the widely accepted 'resegmentation' model, a single vertebra forms from the recombination of the anterior and posterior halves of two adjacent sclerotomes on both sides of the embryo. Although there is supporting evidence for this model in amniotes, it remains uncertain whether it applies to all vertebrates. To explore this, we have investigated vertebral patterning in the zebrafish. Surprisingly, we find that vertebral bodies (centra) arise by secretion of bone matrix from the notochord rather than somites; centra do not form via a cartilage intermediate stage, nor do they contain osteoblasts. Moreover, isolated, cultured notochords secrete bone matrix in vitro, and ablation of notochord cells at segmentally reiterated positions in vivo prevents the formation of centra. Analysis of fss mutant embryos, in which sclerotome segmentation is disrupted, shows that whereas neural arch segmentation is also disrupted, centrum development proceeds normally. These findings suggest that the notochord plays a key, perhaps ancient, role in the segmental patterning of vertebrae.

  7. The origin of conodonts and of vertebrate mineralized skeletons

    Science.gov (United States)

    Murdock, Duncan J.E.; Dong, Xi-Ping; Repetski, John E.; Marone, Federica; Stampanoni, Marco; Donoghue, Philip C.J.

    2013-01-01

    Conodonts are an extinct group of jawless vertebrates whose tooth-like elements are the earliest instance of a mineralized skeleton in the vertebrate lineage, inspiring the ‘inside-out’ hypothesis that teeth evolved independently of the vertebrate dermal skeleton and before the origin of jaws. However, these propositions have been based on evidence from derived euconodonts. Here we test hypotheses of a paraconodont ancestry of euconodonts using synchrotron radiation X-ray tomographic microscopy to characterize and compare the microstructure of morphologically similar euconodont and paraconodont elements. Paraconodonts exhibit a range of grades of structural differentiation, including tissues and a pattern of growth common to euconodont basal bodies. The different grades of structural differentiation exhibited by paraconodonts demonstrate the stepwise acquisition of euconodont characters, resolving debate over the relationship between these two groups. By implication, the putative homology of euconodont crown tissue and vertebrate enamel must be rejected as these tissues have evolved independently and convergently. Thus, the precise ontogenetic, structural and topological similarities between conodont elements and vertebrate odontodes appear to be a remarkable instance of convergence. The last common ancestor of conodonts and jawed vertebrates probably lacked mineralized skeletal tissues. The hypothesis that teeth evolved before jaws and the inside-out hypothesis of dental evolution must be rejected; teeth seem to have evolved through the extension of odontogenic competence from the external dermis to internal epithelium soon after the origin of jaws.

  8. Audiological Findings in Patients with Oculo-Auriculo-Vertebral Spectrum

    Science.gov (United States)

    Sleifer, Pricila; Gorsky, Natalya de Souza; Goetze, Thayse Bienert; Rosa, Rafael Fabiano Machado; Zen, Paulo Ricardo Gazzola

    2014-01-01

    Introduction Oculo-auriculo-vertebral spectrum, also referred to as Goldenhar syndrome, is a condition characterized by alterations involving the development of the structures of the first and second branchial arches. The abnormalities primarily affect the face, the eyes, the spine, and the ears, and the auricular abnormalities are associated with possible hearing loss. Objective To analyze the audiological findings of patients with oculo-auriculo-vertebral spectrum through liminal pure-tone audiometry and speech audiometry test. Methods Cross-sectional study conducted on 10 patients with oculo-auriculo-vertebral spectrum and clinical findings on at least two of the following areas: orocraniofacial, ocular, auricular, and vertebral. All patients underwent tonal and vocal hearing evaluations. Results Seven patients were male and three were female; all had ear abnormalities, and the right side was the most often affected. Conductive hearing loss was the most common (found in 10 ears), followed by sensorineural hearing loss (in five ears), with mixed hearing loss in only one ear. The impairment of the hearing loss ranged from mild to moderate, with one case of profound loss. Conclusions The results show a higher frequency of conductive hearing loss among individuals with the oculo-auriculo-vertebral spectrum phenotype, especially moderate loss affecting the right side. Furthermore, research in auditory thresholds in the oculo-auriculo-vertebral spectrum is important in speech therapy findings about the disease to facilitate early intervention for possible alterations. PMID:25992144

  9. Measurement on Morphology and Kinematics of Crucian Vertebral Joints

    Institute of Scientific and Technical Information of China (English)

    Yonghua Zhang; Jianhui He; Guoqing Zhang

    2011-01-01

    In order to provide data for joints control of our recently designed crucian like biomimetic robot fish, an X-ray photograph technology was adopted to determine the number and length of vertebral joints. A frame-by-frame analysis of high-speed videotapes was conducted to quantify the kinematics of crucian at four speeds (12.651 cm·s-1, 18.201 cm·s 1, 21.901 cm·s 1,24.368 cm·s -1) during cruising. In addition to a brief introduction to experimental conditions and methods, we analyzed the influence of individual diversity on the absolute length as well as the non-dimensional length of vertebral joints. We also presented the maximal angular velocity and acceleration of vertebral joints under four swimming speeds, and provided the change of relative rotation angle, angular difference, angular velocity and angular acceleration of the rear vertebral joints with time at a certain swimming speed of 12.651 cm·s-1. At last, we presented the maximal lateral displacement of each mark at that speed.The study found that the influence of individual diversity on the non-dimensional length of vertebral joints is not significant; the maximal angular velocity and acceleration of vertebral joints increase with swimming speed; angular difference, angular velocity and angular acceleration exhibit two maximal values over one period at a certain swimming speed.

  10. X-ray image segmentation for vertebral mobility analysis

    Energy Technology Data Exchange (ETDEWEB)

    Benjelloun, Mohammed; Mahmoudi, Said [Computer Science Department, Faculty of Engineering of Mons, Mons (Belgium)

    2008-04-15

    The goal of this work is to extract the parameters determining vertebral motion and its variation during flexion-extension movements using a computer vision tool for estimating and analyzing vertebral mobility. To compute vertebral body motion parameters we propose a comparative study between two segmentation methods proposed and applied to lateral X-ray images of the cervical spine. The two vertebra contour detection methods include (1) a discrete dynamic contour model (DDCM) and (2) a template matching process associated with a polar signature system. These two methods not only enable vertebra segmentation but also extract parameters that can be used to evaluate vertebral mobility. Lateral cervical spine views including 100 views in flexion, extension and neutral orientations were available for evaluation. Vertebral body motion was evaluated by human observers and using automatic methods. The results provided by the automated approaches were consistent with manual measures obtained by 15 human observers. The automated techniques provide acceptable results for the assessment of vertebral body mobility in flexion and extension on lateral views of the cervical spine. (orig.)

  11. Craniofacial development of hagfishes and the evolution of vertebrates.

    Science.gov (United States)

    Oisi, Yasuhiro; Ota, Kinya G; Kuraku, Shigehiro; Fujimoto, Satoko; Kuratani, Shigeru

    2013-01-10

    Cyclostomes, the living jawless vertebrates including hagfishes and lampreys, represent the most basal lineage of vertebrates. Although the monophyly of cyclostomes has been supported by recent molecular analyses, the phenotypic traits of hagfishes, especially the lack of some vertebrate-defining features and the reported endodermal origin of the adenohypophysis, have been interpreted as hagfishes exhibiting a more ancestral state than those of all other vertebrates. Furthermore, the adult anatomy of hagfishes cannot be compared easily with that of lampreys. Here we describe the craniofacial development of a series of staged hagfish embryos, which shows that their adenohypophysis arises ectodermally, consistent with the molecular phylogenetic data. This finding also allowed us to identify a pan-cyclostome pattern, one not shared by jawed vertebrates. Comparative analyses indicated that many of the hagfish-specific traits can be explained by changes secondarily introduced into the hagfish lineage. We also propose a possibility that the pan-cyclostome pattern may reflect the ancestral programme for the craniofacial development of all living vertebrates.

  12. The effect of climate manipulations on the herbivory of the pest slug Deroceras reticulatum (Müller, 1774) (Pulmonata: Agriolimacidae)

    Science.gov (United States)

    El-Danasoury, H.; Iglesias-Piñeiro, J.; Córdoba, M.

    2016-10-01

    The pestiferous status of the terrestrial slug Deroceras reticulatum and the strong dependence of its biology and ecology on climatic factors have driven research on the potential responses of the slug to predicted scenarios of climate change. Here, we report two short-term experiments performed outdoors, under seminatural conditions, to assess the behavioural response of D. reticulatum to different climate manipulations in terms of herbivory, by measuring over 7 days the damage inflicted by slug populations to lettuce seedlings. The climate manipulations tested emulate predicted climatic conditions for northwest Spain, specifically winter warming and increased summer rainfall, in contrast respectively with normal winter conditions and summer without rain conditions. In a winter experiment, we compared a normal winter treatment with a winter warming treatment; with respect to the normal winter treatment, the winter warming treatment was characterised by higher temperature, lower relative humidity and the absence of rainfall. In a summer experiment, we compared a summer drought treatment with an increased summer rainfall treatment; with respect to the summer drought treatment, the increased summer rainfall treatment was characterised by the presence of rainfall, while the conditions of temperature and relative humidity were similar in both treatments. Neither winter warming nor increased summer rainfall did lead to a significant increase on the number of seedlings damaged by the slugs. However, with both treatments, we found a moderate increase on the amount of damage suffered by the seedlings. The results are discussed in the context of the potential responses of D. reticulatum to future climatic conditions.

  13. Ecological evaluation of the abundance and effects of elk herbivory in Rocky Mountain National Park, Colorado, 1994-1999

    Science.gov (United States)

    Singer, Francis J.; Zeigenfuss, Linda C.

    2002-01-01

    Severa l Nationa l Park Service units in the Intennountain region possess a number ofclosely related management needs relative to the abundance of wild ungulates and their herbivory effects on plants and ecosystem processes. In 1993, the then National Biological Service (NBS) - now U.S. Geological Survey, Biological Resources Discipline (USGS, BRD)­ initiated a series of research studies in four park units in the Intennountain West., into the abundance and effects of ungulates on park ecosystems. Each of these parks received a number of similar research study elements inclUding: (a) a number of new ungulate grazing exclosures (n = 12-21 exclosures per park); (b) aerial survey sightability models to estimate population Si7..e5 of ungUlates; (e) measures of biomass production and consumption rates near the exclosures and across the landscape; (d) studies of the effects of the grazing on plant abundance, species diversity, and ecosystem effects; and (e) computer model simu lations (SAVANNA) ofthe effects on the ecosystem and plant resources ofdifferent ungulate management scenarios. One park unit, Rocky Mountain National Park, Colorado, re<:eived funding from the U.S. Geological Survey (USGS, BRD) and parallel funding from NPS foran intensive research study of the effects of elk on the park ecosystems.

  14. Percutaneous vertebroplasty in the treatment of vertebral body compression fracture secondary to osteogenesis imperfecta

    Energy Technology Data Exchange (ETDEWEB)

    Rami, Parag M.; Heatwole, Eric V.; Boorstein, Jeffrey M. [Center for Vascular and Interventional Radiology, St. Vincent Mercy Medical Center, Toledo, OH (United States); McGraw, Kevin J. [Riverside Methodist Hospital, Columbus, OH (United States)

    2002-03-01

    Percutaneous vertebroplasty, a minimally invasive interventional radiological procedure, has recently been used effectively for the treatment of symptomatic vertebral body compression fractures. Primary indications for vertebroplasty include osteoporotic compression fracture, osteolytic vertebral metastasis and myeloma, and vertebral hemangioma. We present a case and extend the indication of percutaneous vertebroplasty in a patient with a vertebral body compression fracture secondary to osteogenesis imperfecta. (orig.)

  15. RADIOGRAPHIC MEASUREMENTS OF THE HEIGHTS OF VERTEBRAL BODIES IN THORACIC AND LUMBAR SPINE

    Institute of Scientific and Technical Information of China (English)

    戴力扬

    1996-01-01

    Radiographic measurements was performed on 124 normal adults for anterior, posterior and middle heights of the vertebral bodies in thoracic and lumbar spine. The normal ratios of vertebral height in one vertebral body and one with the adjacent bodies were presented. The method for measurement and its diagnostic value to osteoporodc vertebral fractures were discussed.

  16. Molecular signatures that are distinctive characteristics of the vertebrates and chordates and supporting a grouping of vertebrates with the tunicates.

    Science.gov (United States)

    Gupta, Radhey S

    2016-01-01

    Members of the phylum Chordata and the subphylum Vertebrata are presently distinguished solely on the basis of morphological characteristics. The relationship of the vertebrates to the two non-vertebrate chordate subphyla is also a subject of debate. Analyses of protein sequences have identified multiple conserved signature indels (CSIs) that are specific for Chordata or for Vertebrata. Five CSIs in 4 important proteins are specific for the Vertebrata, whereas two other CSIs are uniquely found in all sequenced chordate species including Ciona intestinalis and Oikapleura dioica (Tunicates) as well as Branchiostoma floridae (Cephalochordates). The shared presence of these molecular signatures by all vertebrates/chordate species, but in no other animal taxa, strongly indicates that the genetic changes represented by the identified CSIs diagnose monophyletic groups. Two other discovered CSIs are uniquely shared by different vertebrate species and by either one (Ciona intestinalis) or both tunicate (Ciona and Oikapleura) species, but they are not found in Branchiostoma or other animal species. Specific presence of these CSIs in different vertebrates and either one or both tunicate species provides strong independent evidence that the vertebrate species are more closely related to the urochordates (tunicates) than to the cephalochordates.

  17. Under-reporting of osteoporotic vertebral fractures on computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Williams, Alexandra L. [Department of Radiology, Manchester Royal Infirmary, Oxford Road, Manchester (United Kingdom)], E-mail: alexandra.firth@virgin.net; Al-Busaidi, Aisha [Department of Radiology, Manchester Royal Infirmary, Oxford Road, Manchester (United Kingdom)], E-mail: albusaidi@doctors.org.uk; Sparrow, Patrick J. [Department of Radiology, Manchester Royal Infirmary, Oxford Road, Manchester (United Kingdom)], E-mail: patsparrow@doctors.org.uk; Adams, Judith E. [Department of Radiology, Manchester Royal Infirmary, Oxford Road, Manchester (United Kingdom); Department of Clinical Radiology, Imaging Science and Biomedical Engineering, Stopford Building, , University of Manchester, Oxford Road, Manchester M13 9PT (United Kingdom)], E-mail: judith.adams@manchester.ac.uk; Whitehouse, Richard W. [Department of Radiology, Manchester Royal Infirmary, Oxford Road, Manchester (United Kingdom)], E-mail: Richard.Whitehouse@cmmc.nhs.uk

    2009-01-15

    Purpose: Osteoporotic vertebral fractures are frequently asymptomatic. They are often not diagnosed clinically or radiologically. Despite this, prevalent osteoporotic vertebral fractures predict future osteoporotic fractures and are associated with increased mortality and morbidity. Appropriate management of osteoporosis can reduce future fracture risk. Fractures on lateral chest radiographs taken for other conditions are frequently overlooked by radiologists. Our aim was to assess the value of computed tomography (CT) in the diagnosis of vertebral fracture and identify the frequency with which significant fractures are missed. Materials and methods: The thoracic CT scans of 100 consecutive male and 100 consecutive female patients over 55 years were reviewed. CT images were acquired on General Electric Lightspeed multi-detector (MD) CT scanners (16 or 32 row) using 1.25 mm slice thickness. Midline sagittal images were reconstructed from the 3D volume images. The presence of moderate (25-40% height loss) or severe (>40% height loss) vertebral fractures between T1 and L1 was determined using an established semi-quantitative method and confirmed by morphological measurement. Results were compared with the formal CT report. Results: Scans of 192 patients were analysed (95 female; 97 male); mean age 70.1 years. Thirty-eight (19.8%) patients had one or more moderate to severe vertebral fractures. Only 5 (13%) were correctly reported as having osteoporotic fractures in the official report. The sensitivity of axial CT images to vertebral fracture was 0.35. Conclusion: Incidental osteoporotic vertebral fractures are under-reported on CT. The sensitivity of axial images in detecting these fractures is poor. Sagittal reformations are strongly recommended to improve the detection rate.

  18. Intraoperative ultrasonography of the vertebral canal in dogs

    Directory of Open Access Journals (Sweden)

    M.A. Bonelli

    2015-06-01

    Full Text Available Intraoperative ultrasound (IOS can provide details on various conditions of the spinal cord and vertebral canal. The aim of the present study was to evaluate the feasibility of using IOS in dogs undergoing spinal surgery and to describe the main findings. The vertebral canal of 21 dogs was examined with intraoperative ultrasonography: 13 underwent spinal surgery for removal of herniated intervertebral disc material, three for stabilization of vertebral fracture/luxation, two for removal of vertebral neoplasia, and three for cauda equina decompression. Particular attention was given to signs of cord compression. Intraoperative ultrasonography was feasible and useful in dogs undergoing surgery for spinal cord or cauda equina decompression and fracture stabilization. It was not paramount for locating the compression when this had been done via computed tomography (CT, but it showed alterations in spinal cord parenchyma not observed on CT and also confirmed adequate decompression of the spinal cord. The main advantages of intraoperative ultrasonography were estimation of vascularization and extent of spinal cord lesion. Most importantly, it allowed real time evaluation of the spinal cord and vertebral canal, which permits the modification of the surgical procedure.

  19. An interactive tutorial-based training technique for vertebral morphometry.

    Science.gov (United States)

    Gardner, J C; von Ingersleben, G; Heyano, S L; Chesnut, C H

    2001-01-01

    The purpose of this work was to develop a computer-based procedure for training technologists in vertebral morphometry. The utility of the resulting interactive, tutorial based training method was evaluated in this study. The training program was composed of four steps: (1) review of an online tutorial, (2) review of analyzed spine images, (3) practice in fiducial point placement and (4) testing. During testing, vertebral heights were measured from digital, lateral spine images containing osteoporotic fractures. Inter-observer measurement precision was compared between research technicians, and between technologists and radiologist. The technologists participating in this study had no prior experience in vertebral morphometry. Following completion of the online training program, good inter-observer measurement precision was seen between technologists, showing mean coefficients of variation of 2.33% for anterior, 2.87% for central and 2.65% for posterior vertebral heights. Comparisons between the technicians and radiologist ranged from 2.19% to 3.18%. Slightly better precision values were seen with height measurements compared with height ratios, and with unfractured compared with fractured vertebral bodies. The findings of this study indicate that self-directed, tutorial-based training for spine image analyses is effective, resulting in good inter-observer measurement precision. The interactive tutorial-based approach provides standardized training methods and assures consistency of instructional technique over time.

  20. A checklist of the vertebrates of Kerala State, India

    Directory of Open Access Journals (Sweden)

    P. O. Nameer

    2015-11-01

    Full Text Available Following the first publication on vertebrates of India (Blanford 1888–1890, a huge wealth of information has been compiled on the vertebrate fauna of various biogeographic zones of the country, especially the Western Ghats.  The state of Kerala comprising of a land area of 38,863km2, 590km coastline, an intricate system of backwaters along the coast, tropical moist forests of the Western Ghats, the highly undulating terrain, and the tropical monsoon is a unique geographical and environmental entity rich in biodiversity.  A region-specific checklist that summarises and documents the current status of vertebrate diversity provides benchmark data for documentation and appreciation of biodiversity at regional level.  Further, with the current rate of global biodiversity loss and concordant conservation efforts, the taxonomic community has a greater responsibility to make scientific information available to scientists, policy makers, politicians, research students and all relevant stakeholders, an attempt that has been made in the present paper.  The State of Kerala has 1847 species of vertebrates in 330 families and 81 orders, of which 386 are endemic to the Western Ghats region (of the Western Ghats - Sri Lanka Hotspot, and 205 species as threatened. Six hundred and eighty species of vertebrates of Kerala have been listed in the various schedules of the Indian Wildlife (Protection Act, while 148 are listed in the different appendices of CITES.  

  1. Insights from amphioxus into the evolution of vertebrate cartilage.

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    Daniel Meulemans

    Full Text Available Central to the story of vertebrate evolution is the origin of the vertebrate head, a problem difficult to approach using paleontology and comparative morphology due to a lack of unambiguous intermediate forms. Embryologically, much of the vertebrate head is derived from two ectodermal tissues, the neural crest and cranial placodes. Recent work in protochordates suggests the first chordates possessed migratory neural tube cells with some features of neural crest cells. However, it is unclear how and when these cells acquired the ability to form cellular cartilage, a cell type unique to vertebrates. It has been variously proposed that the neural crest acquired chondrogenic ability by recruiting proto-chondrogenic gene programs deployed in the neural tube, pharynx, and notochord. To test these hypotheses we examined the expression of 11 amphioxus orthologs of genes involved in neural crest chondrogenesis. Consistent with cellular cartilage as a vertebrate novelty, we find that no single amphioxus tissue co-expresses all or most of these genes. However, most are variously co-expressed in mesodermal derivatives. Our results suggest that neural crest-derived cartilage evolved by serial cooption of genes which functioned primitively in mesoderm.

  2. Vertebrate extinctions and survival across the Cretaceous-Tertiary boundary

    Science.gov (United States)

    Buffetaut, Eric

    1990-01-01

    A critical analysis of the fossil vertebrate record across the Cretaceous-Tertiary boundary shows that the available evidence is far less accurate than that concerning invertebrates and microfossils. Far-reaching conclusions have been drawn from generalisations about vertebrate extinctions in the continental realm based on the local record from western North America, but little is known about patterns of terminal Cretaceous vertebrate extinctions in other parts of the world, and even the western North American record is ambiguous. Despite this unsatisfactory record, it clearly appears that terminal Cretaceous vertebrate extinctions were highly selective, with some groups (e.g. dinosaurs) becoming completely extinct, whereas others seem to be virtually unaffected. This argues against devastating catastrophes of the kind postulated by some recent impact scenarios. However, the survival of groups known to be sensitive to climatic deterioration (such as crocodilians and other non-dinosaurian reptiles) indicates that alternative hypotheses involving gradual but fairly important climatic changes on a world-wide scale are not convincing either. The pattern of extinction and survival among vertebrates across the Cretaceous-Tertiary boundary may be explained as a consequence of the disruption of some food chains following a crisis in the plant kingdom, which itself may have been the result of the atmospheric consequences of unusual extraterrestrial or internal events.

  3. Vegetation change (1988–2010 in Camdeboo National Park (South Africa, using fixed-point photo monitoring: The role of herbivory and climate

    Directory of Open Access Journals (Sweden)

    Mmoto L. Masubelele

    2013-02-01

    Full Text Available Fixed-point photo monitoring supplemented by animal census data and climate monitoring potential has never been explored as a long-term monitoring tool for studying vegetation change in the arid and semi-arid national parks of South Africa. The long-term (1988–2010, fixed-point monitoring dataset developed for the Camdeboo National Park, therefore, provides an important opportunity to do this. Using a quantitative estimate of the change in vegetation and growth form cover in 1152 fixed-point photographs, as well as series of step-point vegetation surveys at each photo monitoring site, this study documented the extent of vegetation change in the park in response to key climate drivers, such as rainfall, as well as land use drivers such as herbivory by indigenous ungulates. We demonstrated the varied response of vegetation cover within three main growth forms (grasses, dwarf shrubs [< 1 m] and tall shrubs [> 1 m] in three different vegetation units and landforms (slopes, plains, rivers within the Camdeboo National Park since 1988. Sites within Albany Thicket and Dwarf Shrublands showed the least change in vegetation cover, whilst Azonal vegetation and Grassy Dwarf Shrublands were more dynamic. Abiotic factors such as drought and flooding, total annual rainfall and rainfall seasonality appeared to have the greatest influence on growth form cover as assessed from the fixed-point photographs. Herbivory appeared not to have had a noticeable impact on the vegetation of the Camdeboo National Park as far as could be determined from the rather coarse approach used in this analysis and herbivore densities remained relatively low over the study duration.Conservation implications: We provided an historical assessment of the pattern of vegetation and climatic trends that can help evaluate many of South African National Parks’ biodiversity monitoring programmes, especially relating to habitat change. It will help arid parks in assessing the trajectories of

  4. Effect of nitrogen and water treatment on leaf chemistry in horsenettle (Solanum carolinense), and relationship to herbivory by flea beetles (Epitrix spp.) and tobacco hornworm (Manduca sexta).

    Science.gov (United States)

    Cipollini, Martin L; Paulk, Eric; Cipollini, Donald F

    2002-12-01

    We studied the interaction between plants (horsenettle; Solanum carolinense) and herbivorous insects (flea beetles; Epitrix spp., and tobacco hornworm; Manduca sexta) by focusing on three questions: (1) Does variation in nitrogen availability affect leaf chemistry as predicted by the carbon-nutrient balance (CNB) hypothesis? (2) Does variation in plant treatment and leaf chemistry affect insect feeding? (3) Is there an interaction between the insect herbivores that is mediated by variation in leaf chemistry? For three successive years (1998-2001), we grew a set of clones of 10 maternal plants under two nitrogen treatments and two water treatments. For each plant in the summer of 2000, we assayed herbivory by hornworms in both indoor (detached leaf) and outdoor (attached leaf) assays, as well as ambient flea beetle damage. Estimates of leaf material consumed were made via analysis of digitized leaf images. We also assayed leaves for total protein, phenolic, and glycoalkaloid content, and for trypsin inhibitor, polyphenol oxidase, and peroxidase activity. Despite strong effects of nitrogen treatment on growth and reproduction, only total protein responded as predicted by CNB. Leaf phenolic levels were increased by nitrogen treatment, polyphenol oxidase activity was decreased, and other leaf parameters were unaffected. Neither hornworm nor flea beetle herbivory could be related to plant treatment or genotype or to variation in any of the six leaf chemical parameters. A negative relationship between flea beetle and hornworm herbivory was found, but was not apparently mediated by any of the measured leaf chemicals. Because leaf resistance was maintained in low nitrogen plants at the apparent expense of growth and reproduction, our results support the concept of a fitness cost of defense, as predicted by the optimal defense hypothesis.

  5. The Arabidopsis immune regulator SRFR1 dampens defences against herbivory by Spodoptera exigua and parasitism by Heterodera schachtii.

    Science.gov (United States)

    Nguyen, Phuong Dung T; Pike, Sharon; Wang, Jianying; Nepal Poudel, Arati; Heinz, Robert; Schultz, Jack C; Koo, Abraham J; Mitchum, Melissa G; Appel, Heidi M; Gassmann, Walter

    2016-05-01

    Plants have developed diverse mechanisms to fine tune defence responses to different types of enemy. Cross-regulation between signalling pathways may allow the prioritization of one response over another. Previously, we identified SUPPRESSOR OF rps4-RLD1 (SRFR1) as a negative regulator of ENHANCED DISEASE SUSCEPTIBILITY1 (EDS1)-dependent effector-triggered immunity against the bacterial pathogen Pseudomonas syringae pv. tomato strain DC3000 expressing avrRps4. The use of multiple stresses is a powerful tool to further define gene function. Here, we examined whether SRFR1 also impacts resistance to a herbivorous insect in leaves and to a cyst nematode in roots. Interestingly, srfr1-1 plants showed increased resistance to herbivory by the beet army worm Spodoptera exigua and to parasitism by the cyst nematode Heterodera schachtii compared with the corresponding wild-type Arabidopsis accession RLD. Using quantitative real-time PCR (qRT-PCR) to measure the transcript levels of salicylic acid (SA) and jasmonate/ethylene (JA/ET) pathway genes, we found that enhanced resistance of srfr1-1 plants to S. exigua correlated with specific upregulation of the MYC2 branch of the JA pathway concurrent with suppression of the SA pathway. In contrast, the greater susceptibility of RLD was accompanied by simultaneously increased transcript levels of SA, JA and JA/ET signalling pathway genes. Surprisingly, mutation of either SRFR1 or EDS1 increased resistance to H. schachtii, indicating that the concurrent presence of both wild-type genes promotes susceptibility. This finding suggests a novel form of resistance in Arabidopsis to the biotrophic pathogen H. schachtii or a root-specific regulation of the SA pathway by EDS1, and places SRFR1 at an intersection between multiple defence pathways.

  6. Herbivory and Competition of Tibetan Steppe Vegetation in Winter Pasture: Effects of Livestock Exclosure and Plateau Pika Reduction.

    Directory of Open Access Journals (Sweden)

    Richard B Harris

    Full Text Available Rangeland degradation has been identified as a serious concern in alpine regions of western China on the Qinghai-Tibetan plateau (QTP. Numerous government-sponsored programs have been initiated, including many that feature long-term grazing prohibitions and some that call for eliminating pastoralism altogether. As well, government programs have long favored eliminating plateau pikas (Ochotona curzoniae, assumed to contribute to degraded conditions. However, vegetation on the QTP evolved in the presence of herbivory, suggesting that deleterious effects from grazing are, to some extent, compensated for by reduced plant-plant competition. We examined the dynamics of common steppe ecosystem species as well as physical indicators of rangeland stress by excluding livestock and reducing pika abundance on experimental plots, and following responses for 4 years. We established 12 fenced livestock exclosures within pastures grazed during winter by local pastoralists, and removed pikas on half of these. We established paired, permanent vegetation plots within and outside exclosures and measured indices of erosion and biomass of common plant species. We observed modest restoration of physical site conditions (reduced bare soil, erosion, greater vegetation cover with both livestock exclusion and pika reduction. As expected in areas protected from grazing, we observed a reduction in annual productivity of plant species avoided by livestock and assumed to compete poorly when protected from grazing. Contrary to expectation, we observed similar reductions in annual productivity among palatable, perennial graminoids under livestock exclusion. The dominant grass, Stipa purpurea, displayed evidence of density-dependent growth, suggesting that intra-specific competition exerted a regulatory effect on annual production in the absence of grazing. Complete grazing bans on winter pastures in steppe habitats on the QTP may assist in the recovery of highly eroded pastures

  7. The effects of herbivory by a mega- and mesoherbivore on tree recruitment in sand forest, South Africa.

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    D D Georgette Lagendijk

    Full Text Available Herbivory by megaherbivores on woody vegetation in general is well documented; however studies focusing on the individual browsing effects of both mega- and mesoherbivore species on recruitment are scarce. We determined these effects for elephant Loxodonta africana and nyala Tragelaphus angasii in the critically endangered Sand Forest, which is restricted to east southern Africa, and is conserved mainly in small reserves with high herbivore densities. Replicated experimental treatments (400 m(2 in a single forest patch were used to exclude elephant, or both elephant and nyala. In each treatment, all woody individuals were identified to species and number of stems, diameter and height were recorded. Results of changes after two years are presented. Individual tree and stem densities had increased in absence of nyala and elephant. Seedling recruitment (based on height and diameter was inhibited by nyala, and by elephant and nyala in combination, thereby preventing recruitment into the sapling stage. Neither nyala or elephant significantly reduced sapling densities. Excluding both elephant and nyala in combination enhanced recruitment of woody species, as seedling densities increased, indicating that forest regeneration is impacted by both mega- and mesoherbivores. The Sand Forest tree community approached an inverse J-shaped curve, with the highest abundance in the smaller size classes. However, the larger characteristic tree species in particular, such as Newtonia hildebrandtii, were missing cohorts in the middle size classes. When setting management goals to conserve habitats of key importance, conservation management plans need to consider the total herbivore assemblage present and the resulting browsing effects on vegetation. Especially in Africa, where the broadest suite of megaherbivores still persists, and which is currently dealing with the 'elephant problem', the individual effects of different herbivore species on recruitment and

  8. Beneficial effects of solar UV-B radiation on soybean yield mediated by reduced insect herbivory under field conditions.

    Science.gov (United States)

    Mazza, Carlos A; Giménez, Patricia I; Kantolic, Adriana G; Ballaré, Carlos L

    2013-03-01

    Ultraviolet-B radiation (UV-B: 280-315 nm) has damaging effects on cellular components and macromolecules. In plants, natural levels of UV-B can reduce leaf area expansion and growth, which can lead to reduced productivity and yield. UV-B can also have important effects on herbivorous insects. Owing to the successful implementation of the Montreal Protocol, current models predict that clear-sky levels of UV-B radiation will decline during this century in response to ozone recovery. However, because of climate change and changes in land use practices, future trends in UV doses are difficult to predict. In the experiments reported here, we used an exclusion approach to study the effects of solar UV-B radiation on soybean crops, which are extensively grown in many areas of the world that may be affected by future variations in UV-B radiation. In a first experiment, performed under normal management practices (which included chemical pest control), we found that natural levels of UV-B radiation reduced soybean yield. In a second experiment, where no pesticides were applied, we found that solar UV-B significantly reduced insect herbivory and, surprisingly, caused a concomitant increase in crop yield. Our data support the idea that UV-B effects on agroecosystems are the result of complex interactions involving multiple trophic levels. A better understanding of the mechanisms that mediate the anti-herbivore effect of UV-B radiation may be used to design crop varieties with improved adaptation to the cropping systems that are likely to prevail in the coming decades in response to agricultural intensification.

  9. A contained ruptured abdominal aortic aneurysm presenting with vertebral erosion.

    Science.gov (United States)

    Li, Yongqi; Li, Lei; Zhang, Dongming; Wang, Xiaomei; Sun, Weidong; Wang, Han

    2017-02-24

    Chronic contained rupture (CCR) of abdominal aortic aneurysm (AAA) with vertebral erosion is a rare condition. Although it has been reported previously, it is still liable to be misdiagnosed. We present a case of CCR of AAA with vertebral erosion. A brief analysis of similar cases reported in the last five years is presented. A 71-year-old male was admitted to our hospital because of severe prickling pain in his left thigh. Computerized tomography angiography revealed an AAA which had caused erosion of L3 vertebral body and the left psoas muscle. An aortotomy was performed and the excised aortic aneurysm replaced with a Dacron graft. Postoperative CT angiography indicated a normal aortic graft. The patient was discharged 13 days after the surgery.

  10. Unusual cause of generalized osteolytic vertebral lesions: a case report

    Directory of Open Access Journals (Sweden)

    Nanda Sudip

    2007-06-01

    Full Text Available Abstract Background Vertebral sarcoidosis is an extremely rare form of osseous sarcoidosis. Although osseous sarcoidosis is almost always an incidental finding of sarcoidosis elsewhere in the body, vertebrae may be the primary disease site. Involvement of vertebrae is usually localized and sclerotic or lytic. Case presentation We describe a case of extensive asymptomatic vertebral involvement by sarcoid with osteolytic lesions. Making the diagnosis requires biopsy and ruling out other commoner causes of osteolytic vertebral lesions. Conclusion We report this case in the hope of expanding the knowledge of osseous sarcoidosis. Our patient was unique in that all involvement was axial with sparing of the peripheral skeleton, near absence of any other organ involvement, diffuse involvement of the whole spine and osteolytic bone lesions.

  11. Evolution of a vertebrate social decision-making network.

    Science.gov (United States)

    O'Connell, Lauren A; Hofmann, Hans A

    2012-06-01

    Animals evaluate and respond to their social environment with adaptive decisions. Revealing the neural mechanisms of such decisions is a major goal in biology. We analyzed expression profiles for 10 neurochemical genes across 12 brain regions important for decision-making in 88 species representing five vertebrate lineages. We found that behaviorally relevant brain regions are remarkably conserved over 450 million years of evolution. We also find evidence that different brain regions have experienced different selection pressures, because spatial distribution of neuroendocrine ligands are more flexible than their receptors across vertebrates. Our analysis suggests that the diversity of social behavior in vertebrates can be explained, in part, by variations on a theme of conserved neural and gene expression networks.

  12. Early Chordate Origins of the Vertebrate Second Heart Field

    Science.gov (United States)

    Stolfi, Alberto; Gainous, T. Blair; Young, John J.; Mori, Alessandro; Levine, Michael; Christiaen, Lionel

    2016-01-01

    The vertebrate heart is formed from diverse embryonic territories, including the first and second heart fields. The second heart field (SHF) gives rise to the right ventricle and outflow tract, yet its evolutionary origins are unclear. We found that heart progenitor cells of the simple chordate Ciona intestinalis also generate precursors of the atrial siphon muscles (ASMs). These precursors express Islet and Tbx1/10, evocative of the splanchnic mesoderm that produces the lower jaw muscles and SHF of vertebrates. Evidence is presented that the transcription factor COE is a critical determinant of ASM fate. We propose that the last common ancestor of tunicates and vertebrates possessed multipotent cardiopharyngeal muscle precursors, and that their reallocation might have contributed to the emergence of the SHF. PMID:20671188

  13. Congenital malformations of the vertebral column in ancient amphibians.

    Science.gov (United States)

    Witzmann, F; Rothschild, B M; Hampe, O; Sobral, G; Gubin, Y M; Asbach, P

    2014-04-01

    Temnospondyls, the largest group of Palaeozoic and Mesozoic amphibians, primitively possess rhachitomous vertebrae with multipartite centra (consisting of one horse-shoe-shaped inter- and paired pleurocentra). In a group of temnospondyls, the stereospondyls, the intercentra became pronounced and disc-like, whereas the pleurocentra were reduced. We report the presence of congenital vertebral malformations (hemi, wedge and block vertebrae) in Permian and Triassic temnospondyls, showing that defects of formation and segmentation in the tetrapod vertebral column represent a fundamental failure of somitogenesis that can be followed throughout tetrapod evolution. This is irrespective of the type of affected vertebra, that is, rhachitomous or stereospondylous, and all components of the vertebra can be involved (intercentrum, pleurocentrum and neural arch), either together or independently on their own. This is the oldest known occurrence of wedge vertebra and congenital block vertebra described in fossil tetrapods. The frequency of vertebral congenital malformations in amphibians appears unchanged from the Holocene.

  14. Diagnosis by images of vertebral tuberculosis. A case report

    Directory of Open Access Journals (Sweden)

    Aimara de la Caridad Vergara Santos

    2015-04-01

    Full Text Available Vertebral tuberculosis, also known like espondilitis tuberculous, disease of Pott or Pott's disease, is a presentation of extra-pulmonary tuberculosis. A case of a 35 year old female Venezuelan patient was presented with a history of sacrum lumbar pain. A study of magnetic resonance in a high-technology center was accomplished and Pott's disease was diagnosed. The tuberculosis constitutes a heath problem in Venezuela as well as in many other countries. Pott's disease is not common in adults, but it should be taken into account on persistent or chronic lumbar pain. It is important to diagnose the disease timely to administrate the specific treatment during the first manifestations and avoid vertebral instability, neurological compromise or xiphotic vertebral deformity.

  15. Anatomia do sulco da artéria vertebral

    OpenAIRE

    CARVALHO, Max Franco de; Rocha,Roberta Teixeira; Monteiro,João Tiago Silva; Pereira, Carlos Umberto; Defino,Helton Luiz Aparecido

    2009-01-01

    INTRODUÇÃO: Diversas técnicas cirúrgicas têm sido realizadas na região craniocervical devido a diversas patologias. Durante o acesso cirúrgico a essa região existe um risco potencial de lesão iatrogênica da artéria vertebral, relacionado ao acesso lateral amplo e à avaliação inadequada da anatomia local. Variações no trajeto da artéria vertebral ocasionam maior risco de lesão vascular. O estudo pré-operatório por imagem da anatomia da artéria vertebral e do seu sulco tem sido realizado para a...

  16. Evolutionary perspectives on clonal reproduction in vertebrate animals.

    Science.gov (United States)

    Avise, John C

    2015-07-21

    A synopsis is provided of different expressions of whole-animal vertebrate clonality (asexual organismal-level reproduction), both in the laboratory and in nature. For vertebrate taxa, such clonal phenomena include the following: human-mediated cloning via artificial nuclear transfer; intergenerational clonality in nature via parthenogenesis and gynogenesis; intergenerational hemiclonality via hybridogenesis and kleptogenesis; intragenerational clonality via polyembryony; and what in effect qualifies as clonal replication via self-fertilization and intense inbreeding by simultaneous hermaphrodites. Each of these clonal or quasi-clonal mechanisms is described, and its evolutionary genetic ramifications are addressed. By affording an atypical vantage on standard vertebrate reproduction, clonality offers fresh perspectives on the evolutionary and ecological significance of recombination-derived genetic variety.

  17. Vertebral split fractures: Technical feasibility of percutaneous vertebroplasty

    Energy Technology Data Exchange (ETDEWEB)

    Huwart, Laurent, E-mail: huwart.laurent@wanadoo.fr [Department of Radiology, Hôpital Archet 2, Centre Hospitalo-Universitaire de Nice, Nice (France); Foti, Pauline, E-mail: pfoti@hotmail.fr [Department of Biostatistics, Hôpital Archet 2, Centre Hospitalo-Universitaire de Nice, Nice (France); Andreani, Olivier, E-mail: andreani.olivier@gmail.com [Department of Radiology, Hôpital Archet 2, Centre Hospitalo-Universitaire de Nice, Nice (France); Hauger, Olivier, E-mail: olivier.hauger@chubordeaux.fr [Department of Radiology, Hôpital Pellegrin, Centre Hospitalo-Universitaire de Bordeaux, Bordeaux (France); Cervantes, Elodie, E-mail: elodie.cervantes@live.fr [Department of Radiology, Hôpital Archet 2, Centre Hospitalo-Universitaire de Nice, Nice (France); Brunner, Philippe, E-mail: pbrunner@chpg.mc [Department of Radiology, Hôpital Princesse Grasse de Monaco (Monaco); Boileau, Pascal, E-mail: boileau.p@chu-nice.fr [Department of Orthopedic Surgery, Hôpital Archet 2, Centre Hospitalo-Universitaire de Nice, Nice (France); Amoretti, Nicolas, E-mail: amorettinicolas@yahoo.fr [Department of Radiology, Hôpital Archet 2, Centre Hospitalo-Universitaire de Nice, Nice (France)

    2014-01-15

    Objective: The treatment of vertebral split fractures remains controversial, consisting of either corset or internal fixation. The aim of this study was to evaluate the technical feasibility of CT- and fluoroscopy-guided percutaneous vertebroplasty in the treatment of vertebral split fractures. Materials and methods: Institutional review board approval and informed consent were obtained for this study. Sixty-two consecutive adult patients who had post-traumatic vertebral split fractures (A2 according to the AO classification) without neurological symptoms were prospectively treated by percutaneous vertebroplasty. All these procedures were performed by an interventional radiologist under computed tomography (CT) and fluoroscopy guidance by using only local anaesthesia. Postoperative outcome was assessed using the visual analogue scale (VAS) and Oswestry disability index (ODI) scores. Results: Vertebroplasty was performed on thoracic and lumbar vertebrae, creating a cement bridge between the displaced fragment and the rest of the vertebral body. Seven discal cement leakages (11%) were observed, without occurrence of adjacent vertebral compression fractures. The mean VAS measurements ± standard deviation (SD) significantly decreased from 7.9 ± 1.5 preoperatively to 3.3 ± 2.1 at 1 day, 2.2 ± 2.0 at 1 month, and 1.8 ± 1.4 at 6 months (P < 0.001). The mean ODI scores ± SD had also a significant improvement: 62.3 ± 17.2 preoperatively and 15.1 ± 6.0 at the 6-month follow-up (P < 0.001). Conclusion: This study suggests that type A2 vertebral fractures could be successfully treated by CT- and fluoroscopy-guided percutaneous vertebroplasty.

  18. Do global diversity patterns of vertebrates reflect those of monocots?

    Directory of Open Access Journals (Sweden)

    Lynsey McInnes

    Full Text Available Few studies of global diversity gradients in plants exist, largely because the data are not available for all species involved. Instead, most global studies have focussed on vertebrates, as these taxa have historically been associated with the most complete data. Here, we address this shortfall by first investigating global diversity gradients in monocots, a morphologically and functionally diverse clade representing a quarter of flowering plant diversity, and then assessing congruence between monocot and vertebrate diversity patterns. To do this, we create a new dataset that merges biome-level associations for all monocot genera with country-level associations for almost all ∼70,000 species. We then assess the evidence for direct versus indirect effects of this plant diversity on vertebrate diversity using a combination of linear regression and structural equation modelling (SEM. Finally, we also calculate overlap of diversity hotspots for monocots and each vertebrate taxon. Monocots follow a latitudinal gradient although with pockets of extra-tropical diversity, mirroring patterns in vertebrates. Monocot diversity is positively associated with vertebrate diversity, but the strength of correlation varies depending on the clades being compared. Monocot diversity explains marginal amounts of variance (<10% after environmental factors have been accounted for. However, correlations remain among model residuals, and SEMs apparently reveal some direct effects of monocot richness. Our results suggest that collinear responses to environmental gradients are behind much of the congruence observed, but that there is some evidence for direct effects of producer diversity on consumer diversity. Much remains to be done before broad-scale diversity gradients among taxa are fully explained. Our dataset of monocot distributions will aid in this endeavour.

  19. Uniextrapedicular kyphoplasty for the treatment of thoracic osteoporotic vertebral fractures.

    Science.gov (United States)

    Ge, Zhaohui; Ma, Rong; Chen, Zhen; Zhang, Huiyong; Ding, Huiqiang; Liang, Siming; Suo, Zhigang

    2013-08-01

    Osteoporotic vertebral compression fractures are common and cause pain and disability. Most osteoporotic vertebral compression fractures occur in the lower thoracic and thoracolumbar spine. Percutaneous balloon kyphoplasty through a transpedicular approach is a classic procedure performed to treat osteoporotic vertebral compression fractures. However, due to the slender morphology of the pedicles, small pedicle size, and the angular severity of thoracic kyphosis, performing kyphoplasty in middle and high thoracic levels is technically challenging. The purpose of this retrospective study was to evaluate the clinical outcomes of single-balloon kyphoplasty for the treatment of thoracic osteoporotic vertebral compression fractures via an extrapedicular approach. Between July 2004 and May 2008, thirty-eight patients with thoracic osteoporotic vertebral compression fractures underwent percutaneous kyphoplasty via a unilateral extrapedicular approach. Average patient age was 60.3 years. Symptomatic levels ranged from T4 to T12. All affected vertebrae were identified via physical examination, magnetic resonance imaging, and radiographs. Pain relief, vertebral height restoration, and kyphosis correction were compared pre- and postoperatively using the visual analog scale and radiographs. The operation was successful in all patients. Average injected bone cement volume was 3.2±1.4 mL. Mean follow-up was 9.5 months. Visual analog scale pain score improved in 36 of 38 patients postoperatively. Mean visual analog scale pain score was 8.92±0.682 preoperatively and 2.40±0.31 postoperatively and remained at 2.80±0.34 until last follow-up. Mean middle body height correction ratio was 50.9%±34.6%. No lateral wedging was found in the coronal alignment of the treated vertebrae. Three (7.9%) patients sustained cement extravasation with no adverse events. Kyphoplasty through a unilateral extrapedicular approach can achieve convergent and proper cement filling in the affected

  20. Hox cluster organization in the jawless vertebrate Petromyzon marinus.

    Science.gov (United States)

    Force, Allan; Amores, Angel; Postlethwait, John H

    2002-04-15

    Large-scale gene amplifications may have facilitated the evolution of morphological innovations that accompanied the origin of vertebrates. This hypothesis predicts that the genomes of extant jawless fish, scions of deeply branching vertebrate lineages, should bear a record of these events. Previous work suggests that nonvertebrate chordates have a single Hox cluster, but that gnathostome vertebrates have four or more Hox clusters. Did the duplication events that produced multiple vertebrate Hox clusters occur before or after the divergence of agnathan and gnathostome lineages? Can investigation of lamprey Hox clusters illuminate the origins of the four gnathostome Hox clusters? To approach these questions, we cloned and sequenced 13 Hox cluster genes from cDNA and genomic libraries in the lamprey, Petromyzon marinus. The results suggest that the lamprey has at least four Hox clusters and support the model that gnathostome Hox clusters arose by a two-round-no-cluster-loss mechanism, with tree topology [(AB)(CD)]. A three-round model, however, is not rigorously excluded by the data and, for this model, the tree topologies [(D(C(AB))] and [(C(D(AB))] are most parsimonious. Gene phylogenies suggest that at least one Hox cluster duplication occurred in the lamprey lineage after it diverged from the gnathostome lineage. The results argue against two or more rounds of duplication before the divergence of agnathan and gnathostome vertebrates. If Hox clusters were duplicated in whole-genome duplication events, then these data suggest that, at most, one whole genome duplication occurred before the evolution of vertebrate developmental innovations.

  1. Prevalent morphometric vertebral fractures in professional male rugby players.

    Directory of Open Access Journals (Sweden)

    Karen Hind

    Full Text Available There is an ongoing concern about the risk of injury to the spine in professional rugby players. The objective of this study was to investigate the prevalence of vertebral fracture using vertebral fracture assessment (VFA dual energy X-ray absorptiometry (DXA imaging in professional male rugby players. Ninety five professional rugby league (n = 52 and union (n = 43 players (n = 95; age 25.9 (SD 4.3 years; BMI: 29.5 (SD 2.9 kg.m2 participated in the research. Each participant received one VFA, and one total body and lumbar spine DXA scan (GE Lunar iDXA. One hundred and twenty vertebral fractures were identified in over half of the sample by VFA. Seventy four were graded mild (grade 1, 40 moderate (grade 2 and 6 severe (grade 3. Multiple vertebral fractures (≥2 were found in 37 players (39%. There were no differences in prevalence between codes, or between forwards and backs (both 1.2 v 1.4; p>0.05. The most common sites of fracture were T8 (n = 23, T9 (n = 18 and T10 (n = 21. The mean (SD lumbar spine bone mineral density Z-score was 2.7 (1.3 indicating high player bone mass in comparison with age- and sex-matched norms. We observed a high number of vertebral fractures using DXA VFA in professional rugby players of both codes. The incidence, aetiology and consequences of vertebral fractures in professional rugby players are unclear, and warrant timely, prospective investigation.

  2. Vertebral Fractures and Spondylosis in Men - Original Investigation

    Directory of Open Access Journals (Sweden)

    Selmin Gülbahar

    2008-04-01

    Full Text Available Aim: The aim of this study was to investigate the relationship between vertebral fractures and spondylosis and bone mineral density in men older than 60 years. Material and Method: Thirty-two men with back and low back pain aged over 60 years were included into the study. Thoracic and lumbar spine radiographs were taken and, anterior, central and posterior heights of each vertebral body from T4 to L5 was measured and than the number of vertebral fractures was assessed. Osteophyte and disc scores were used for evaluation of spondylosis. Bone mineral density was measured by dual-energy-X-ray absorptiometry. Measurements were obtained from lumbar vertebrae and proximal femoral region. Results: Significant positive correlations were found between vertebral fracture and osteophyte score and bone mineral density of total femoral region. When osteophyte score and total femoral bone mineral density were taken into consideration, there were no significant correlations between other parameters and vertebral fracture. Significant positive correlations were observed between osteophyte score and bone mineral density and t scores of L1-4. Also there were significant positive correlations between disc score and both bone mineral density and t scores of L1-4. Significant positive correlation was also found between femoral bone density and body weight. Conclusion: Finally, lumbar bone mineral density increases with spinal degenerative changes, but the increase in bone mineral density can not prevent sub clinic vertebral fractures. Especially, in the men who have intensive spinal degenerative changes, the measurement of lumbar bone mineral density is not enough for determining the fracture risk. Measurement of femoral bone mineral density and evaluation of clinic risk factors are more important for determining the fracture risk. (From the World of Osteoporosis 2008;14:1-6

  3. Unexpected multiplicity of QRFP receptors in early vertebrate evolution.

    Science.gov (United States)

    Larhammar, Dan; Xu, Bo; Bergqvist, Christina A

    2014-01-01

    The neuropeptide QRFP, also called 26RFa, and its G protein-coupled receptor GPR103 have been identified in all vertebrates investigated. In mammals, this peptide-receptor pair has been found to have several effects including stimulation of appetite. Recently, we reported that a QRFP peptide is present in amphioxus, Branchiostoma floridae, and we also identified a QRFP receptor (QRFPR) that mediates a functional response to sub-nanomolar concentrations of the amphioxus peptide as well as short and long human QRFP (Xu et al., submitted). Because the ancestral vertebrate underwent two tetraploidizations, it might be expected that duplicates of the QRFP gene and its receptor gene may exist. Indeed, we report here the identification of multiple vertebrate QRFPR genes. Three QRFPR genes are present in the coelacanth Latimeria chalumnae, representing an early diverging sarcopterygian lineage. Three QRFPR genes are present in the basal actinopterygian fish, the spotted gar. Phylogenetic and chromosomal analyses show that only two of these receptor genes are orthologous between the two species, thus demonstrating a total of four distinct vertebrate genes. Three of the QRFPR genes resulted from the early vertebrate tetraploidizations and were copied along with syntenic neuropeptide Y receptor genes. The fourth QRFPR gene may be an even older and distinct lineage. Because mammals and birds have only a single QRFPR gene, this means that three genes have been lost in these lineages, and at least one of these was lost independently in mammals and birds because it is still present in a turtle. In conclusion, these results show that the QRFP system gained considerable complexity in the early stages of vertebrate evolution and still maintains much of this in some lineages, and that it has been secondarily reduced in mammals.

  4. Unexpected multiplicity of QRFP receptors in early vertebrate evolution

    Directory of Open Access Journals (Sweden)

    Dan eLarhammar

    2014-10-01

    Full Text Available The neuropeptide QRFP, also called 26RFa, and its G protein-coupled receptor GPR103 have been identified in all vertebrates investigated. In mammals, this peptide-receptor pair has been found to have several effects including stimulation of appetite. Recently, we reported that a QRFP peptide is present in amphioxus, Branchiostoma floridae, and we also identified a QRFP receptor (QRFPR that mediates a functional response to sub-nanomolar concentrations of the amphioxus peptide as well as short and long human QRFP (Xu et al., submitted. Because the ancestral vertebrate underwent two tetraploidizations, it might be expected that duplicates of the QRFP gene and its receptor gene may exist. Indeed, we report here the identification of multiple vertebrate QRFPR genes. Three QRFPR genes are present in the coelacanth Latimeria chalumnae, representing an early diverging sarcopterygian lineage. Three QRFP receptor genes are present in the basal actinopterygian fish, the spotted gar. Phylogenetic and chromosomal analyses show that only two of these receptor genes are orthologous between the two species, thus demonstrating a total of four distinct vertebrate genes. Three of the QRFPR genes resulted from the early vertebrate tetraploidizations and were copied along with syntenic neuropeptide Y receptor genes. The fourth QRFPR gene may be an even older and distinct lineage. Because mammals and birds have only a single QRFP receptor gene, this means that three genes have been lost in these lineages, and at least one of these was lost independently in mammals and birds because it is still present in a turtle. In conclusion, these results show that the QRFP system gained considerable complexity in the early stages of vertebrate evolution and still does so in some lineages, and that it has been secondarily reduced in mammals.

  5. Lumbo-costo-vertebral syndrome with congenital lumbar hernia.

    Science.gov (United States)

    Gupta, Lucky; Mala, Tariq Ahmed; Gupta, Rahul; Malla, Shahid Amin

    2014-01-01

    Lumbo-costo-vertebral syndrome (LCVS) is a set of rare abnormalities involving vertebral bodies, ribs, and abdominal wall. We present a case of LCVS in a 2-year-old girl who had a progressive swelling over left lumbar area noted for the last 12 months. Clinical examination revealed a reducible swelling with positive cough impulse. Ultrasonography showed a defect containing bowel loops in the left lumbar region. Chest x-ray showed scoliosis and hemivertebrae with absent lower ribs on left side. Meshplasty was done.

  6. Molecular genetics and the evolution of ultraviolet vision in vertebrates

    Science.gov (United States)

    Shi, Yongsheng; Radlwimmer, F. Bernhard; Yokoyama, Shozo

    2001-01-01

    Despite the biological importance of UV vision, its molecular bases are not well understood. Here, we present evidence that UV vision in vertebrates is determined by eight specific amino acids in the UV pigments. Amino acid sequence analyses show that contemporary UV pigments inherited their UV sensitivities from the vertebrate ancestor by retaining most of these eight amino acids. In the avian lineage, the ancestral pigment lost UV sensitivity, but some descendants regained it by one amino acid change. Our results also strongly support the hypothesis that UV pigments have an unprotonated Schiff base-linked chromophore. PMID:11573008

  7. Gout and the Risk of Non-vertebral Fracture.

    Science.gov (United States)

    Kim, Seoyoung C; Paik, Julie M; Liu, Jun; Curhan, Gary C; Solomon, Daniel H

    2017-02-01

    Prior studies suggest an association between osteoporosis, systemic inflammation, and pro-inflammatory cytokines such as interleukin (IL)-1 and IL-6. Conflicting findings exist on the association between hyperuricemia and osteoporosis. Furthermore, it remains unknown whether gout, a common inflammatory arthritis, affects fracture risk. Using data from a US commercial health plan (2004-2013), we evaluated the risk of non-vertebral fracture (ie, forearm, wrist, hip, and pelvis) in patients with gout versus those without. Gout patients were identified with ≥2 diagnosis codes and ≥1 dispensing for a gout-related drug. Non-gout patients, identified with ≥2 visits coded for any diagnosis and ≥1 dispensing for any prescription drugs, were free of gout diagnosis and received no gout-related drugs. Hip fracture was the secondary outcome. Fractures were identified with a combination of diagnosis and procedure codes. Cox proportional hazards models compared the risk of non-vertebral fracture in gout patients versus non-gout, adjusting for more than 40 risk factors for osteoporotic fracture. Among gout patients with baseline serum uric acid (sUA) measurements available, we assessed the risk of non-vertebral fracture associated with sUA. We identified 73,202 gout and 219,606 non-gout patients, matched on age, sex, and the date of study entry. The mean age was 60 years and 82% were men. Over the mean 2-year follow-up, the incidence rate of non-vertebral fracture per 1,000 person-years was 2.92 in gout and 2.66 in non-gout. The adjusted hazard ratio (HR) was 0.98 (95% confidence interval [CI] 0.85-1.12) for non-vertebral fracture and 0.83 (95% CI 0.65-1.07) for hip fracture in gout versus non-gout. Subgroup analysis (n = 15,079) showed no association between baseline sUA and non-vertebral fracture (HR = 1.03, 95% CI 0.93-1.15), adjusted for age, sex, comorbidity score, and number of any prescription drugs. Gout was not associated with a risk of non-vertebral

  8. Lumbo-Costo-Vertebral Syndrome with Congenital Lumbar Hernia

    Directory of Open Access Journals (Sweden)

    Lucky Gupta

    2014-02-01

    Full Text Available Lumbo-costo-vertebral syndrome (LCVS is a set of rare abnormalities involving vertebral bodies, ribs, and abdominal wall. We present a case of LCVS in a 2-year-old girl who had a progressive swelling over left lumbar area noted for the last 12 months. Clinical examination revealed a reducible swelling with positive cough impulse. Ultrasonography showed a defect containing bowel loops in the left lumbar region. Chest x-ray showed scoliosis and hemivertebrae with absent lower ribs on left side. Meshplasty was done.

  9. FULL SCIENTIFIC REPORTS - Complex vertebral malformation in Holstein calves

    DEFF Research Database (Denmark)

    Agerholm, Jørgen S.; Bendixen, Christian; Andersen, Ole;

    2001-01-01

    was characterized by shortening of the cervical and thoracic parts of the vertebral column due to multiple hemivertebrae, fused and misshaped vertebrae, and scoliosis. Symmetrical flexures of the carpal joints and the metacarpophalangeal joint in combination with a slight lateral rotation of the phalanges also were...... present. Similar low-grade arthrogryposis was present in the posterior limbs. Fifty percent of the calves had heart malformation. Other malformations occurred in a few calves. Complex vertebral malformation (CVM) is proposed as the designation for this defect. A genetic etiology is indicated because cases...

  10. The origin and early phylogenetic history of jawed vertebrates.

    Science.gov (United States)

    Brazeau, Martin D; Friedman, Matt

    2015-04-23

    Fossils of early gnathostomes (or jawed vertebrates) have been the focus of study for nearly two centuries. They yield key clues about the evolutionary assembly of the group's common body plan, as well the divergence of the two living gnathostome lineages: the cartilaginous and bony vertebrates. A series of remarkable new palaeontological discoveries, analytical advances and innovative reinterpretations of existing fossil archives have fundamentally altered a decades-old consensus on the relationships of extinct gnathostomes, delivering a new evolutionary framework for exploring major questions that remain unanswered, including the origin of jaws.

  11. Noncanonical Wnt/PCP signaling during vertebrate gastrulation.

    Science.gov (United States)

    Tada, Masazumi; Kai, Masatake

    2009-03-01

    The branch of the Wnt pathway, related to planar cell polarity signaling in Drosophila, is fundamental not only to the establishment of tissue polarity but also to a variety of morphogenetic processes in vertebrates. The genetic pathway has been noted for its similarity as well as divergence of between vertebrates and Drosophila. This review focuses on issues related to the complexity of the output of the planar cell polarity pathway during gastrulation in zebrafish and Xenopus and, to a lesser extent, during gastrulation/neurulation in mice.

  12. Facio-auricular vertebral syndrome-a case report

    Directory of Open Access Journals (Sweden)

    Reddy M

    2005-01-01

    Full Text Available Facio Auricular Vertebral (FAV or Goldenhar syndrome is a very rare kind of syndromic deafness and is inherited as autosomal dominant. A study was taken up to understand the prevalence of this syndrome in children below the age of 14 years with hearing loss. Out of 1073 children with hearing impairment, Goldenhar syndrome was observed only in 1 (0.09% case. The child suffered severe hearing loss. Facial paralysis and hemifacial microsomia were prominent features observed in the child. Facio-Auricular-Vertebral syndrome is therefore synonymously used with Goldenhar syndrome.

  13. Transient cortical blindness following vertebral angiography: a case report.

    Science.gov (United States)

    Lo, Lai Wan; Chan, Ho Fung; Ma, Ka Fai; Cheng, Lik Fai; Chan, Tony Kt

    2015-02-01

    Transient cortical blindness (TCB) is a rare but well-known complication of cerebral angiography. Its pathophysiology remains uncertain. We would like to report a case of TCB in a patient during a follow up vertebral angiogram for post-coil embolization of left posterior inferior cerebellar artery aneurysm. Patient's vision was resumed spontaneously within 24 hours after angiography, with no residual neurological deficit in subsequent clinical follow up. Multi-modality imaging evaluation including vertebral angiography, brain CT and MRI performed on same day are presented.

  14. An invertebrate stomach's view on vertebrate ecology: certain invertebrates could be used as "vertebrate samplers" and deliver DNA-based information on many aspects of vertebrate ecology.

    Science.gov (United States)

    Calvignac-Spencer, Sébastien; Leendertz, Fabian H; Gilbert, M Thomas P; Schubert, Grit

    2013-11-01

    Recent studies suggest that vertebrate genetic material ingested by invertebrates (iDNA) can be used to investigate vertebrate ecology. Given the ubiquity of invertebrates that feed on vertebrates across the globe, iDNA might qualify as a very powerful tool for 21st century population and conservation biologists. Here, we identify some invertebrate characteristics that will likely influence iDNA retrieval and elaborate on the potential uses of invertebrate-derived information. We hypothesize that beyond inventorying local faunal diversity, iDNA should allow for more profound insights into wildlife population density, size, mortality, and infectious agents. Based on the similarities of iDNA with other low-quality sources of DNA, a general technical framework for iDNA analyses is proposed. As it is likely that no such thing as a single ideal iDNA sampler exists, forthcoming research efforts should aim at cataloguing invertebrate properties relevant to iDNA retrieval so as to guide future usage of the invertebrate tool box.

  15. Does inter-plant variation in sprouting time affect the growth/reproduction trade-off and herbivory in a tropical tree species?

    Directory of Open Access Journals (Sweden)

    Marcilio Fagundes

    Full Text Available ABSTRACT The timing of phenological events varies within and among populations, affecting the performance of individual plants differently. We evaluated the effects of relative variation in sprouting time on the display of reproductive events, vegetative growth and herbivory in Copaifera langsdorffii (Fabaceae. A total of 93 trees of C. langsdorffii was monitored daily to determine their sprouting time. We collected ten terminal branches of each plant to evaluate vegetative growth, production of defense compounds and insect herbivore damage. The sprouting time for the studied population lasted 67 days. Variation in sprouting time did not affect the probability of plants to enter the reproductive stage. Plants that entered the reproductive stage showed greater vegetative biomass. Variation in sprouting time had a negative relationship with branch growth and a positive relationship with the number of leaflets. Leaf phenol concentration did not vary in relation to sprouting time or plant phenology, but herbivory was higher in plants that sprouted later. The relationships among plant sprouting time, vegetative development and display of reproductive stage in C. langsdorffii are discussed. The results of this study also suggest that early sprouting prior to the rainy season is a strategy used by C. langsdorffii to escape herbivores attacks.

  16. Response of Rice to Insect Elicitors and the Role of OsJAR1 in Wound and Herbivory-Induced JA-IIe Accumulation

    Institute of Scientific and Technical Information of China (English)

    Kaori Fukumoto; Kabir Md Alamgir; Yuko Yamashita; Izumi C.Mori; Hideyuki Matsuura; Ivan Galis

    2013-01-01

    Plants produce jasmonic acid (JA) and its amino acid conjugate,jasmonoyI-L-isoleucine (JA-IIe) as major defense signals in response to wounding and herbivory.In rice (Oryza sativa),JA and JA-IIe rapidly increased after mechanical damage,and this increase was further amplified when the wounds were treated with oral secretions from generalist herbivore larvae,lawn armyworms (Spodoptera mauritia),revealing for the first time active perception mechanisms of herbivore-associated elicitor(s) in rice.In the rice genome,two OsJAR genes can conjugate JA and IIe and form JA-IIe in vitro; however,their function in herbivoryinduced accumulation of JA-IIe has not been investigated.By functional characterization of TOS17 retrotrensposon-tagged Osjar1 plants and their response to simulated herbivory,we show that OsJAR1 is essential for JA-IIe production in herbivore-attacked,field-grown plants.In addition,OsJAR1 was required for normal seed development in rice under field conditions.Our results suggest that OsJAR1 possesses at least two major functions in rice defense and development that cannot be complemented by the additional OsJAR2 gene function,although this gene previously showed overlapping enzyme activity in vitro.

  17. Embolization for vertebral metastases of follicular thyroid carcinoma.

    Science.gov (United States)

    Smit, J W; Vielvoye, G J; Goslings, B M

    2000-03-01

    The technique of selective embolization has been applied for years in the treatment of vascular anomalies, severe hemorrhage and benign or malignant tumors, notably vertebral metastases of renal cell carcinoma. Because this technique is relatively easy to perform and offers immediate relief of symptoms, it is an attractive option for patients with vertebral metastases of thyroid carcinoma with signs of spinal cord compression. In these patients, other treatment modalities like radioactive iodine, external irradiation, or surgery are more cumbersome or less effective in the short term. We describe four patients with metastasized follicular thyroid carcinoma, presenting with neurological symptoms due to vertebral metastases. All patients had undergone total thyroidectomy, ranging from 1 month to 4 yr before embolization. Embolization was combined with iodine-131 therapy when appropriate. Selective catheterization of the arteries feeding the metastases was performed, followed by infusion of polyvinyl alcohol particles (Ivalon). The procedure was technically successful in all patients without adverse effects. In the patients described, embolization resulted in rapid resolution of neurological symptoms, sometimes within hours. The therapeutic effect lasted from months to years. We conclude that embolization of vertebral metastases of follicular thyroid carcinoma is an attractive palliative therapeutic option that may offer rapid relief of symptoms.

  18. FGF signalling: diverse roles during early vertebrate embryogenesis.

    Science.gov (United States)

    Dorey, Karel; Amaya, Enrique

    2010-11-01

    Fibroblast growth factor (FGF) signalling has been implicated during several phases of early embryogenesis, including the patterning of the embryonic axes, the induction and/or maintenance of several cell lineages and the coordination of morphogenetic movements. Here, we summarise our current understanding of the regulation and roles of FGF signalling during early vertebrate development.

  19. A Rare Case: Gastric Cancer; Involving Primery Thoracal Vertebral Metastases

    Directory of Open Access Journals (Sweden)

    Harun Arslan

    2013-06-01

    Full Text Available Primery bone metastases rarely occur in gastric cancer. Bone metastases indicate that the prognosis is bad. In that article we present a case that is diagnosed as a gastric cancer with primary bone metasteses that caused pathologic thoracal vertebral fracture seenby computer ised tomography.

  20. Vertebrate predator-prey interactions in a seasonal environment

    DEFF Research Database (Denmark)

    Schmidt, Niels Martin; Berg, Thomas B; Forchhammer, Mads;

    2008-01-01

    The High Arctic, with its low number of species, is characterised by a relatively simple ecosystem, and the vertebrate predator-prey interactions in the valley Zackenbergdalen in Northeast Greenland are centred around the collared lemming Dicrostonyx groenlandicus and its multiple predators......, hence, affect not only the seasonal but also the inter-annual dynamics of the collared lemming population in Zackenbergdalen...

  1. [Simultaneous carotid and vertebral revascularization in the aged].

    Science.gov (United States)

    Illuminati, G; Caliò, F G; Bertagni, A; Piermattei, A; Vietri, F; Martinelli, V

    1997-09-01

    Five patients of a mean age of 76, have been submitted to combined vertebral and carotid artery revascularization for a severe vertebro-basilar insufficiency. Vertebral artery revascularization consisted of a transposition to the common carotid artery in one case and of a carotid-distal vertebral artery saphenous bypass graft. The associated carotid artery revascularization consisted of a carotid endarterectomy with patch in 4 cases and without patch in one case. There were no postoperative mortality and no postoperative stroke. Postoperative morbidity included a transitory revascularization syndrome, a myocardial ischemia and a Horner's syndrome. Complete relief of vertebrobasilar symptoms was obtained in 4 patients whereas in one patient only a mild positional vertigo persisted. All vascular reconstructions have been assessed with postoperative arteriography and duplex-scan every six months. At 11 months mean follow-up, all revascularizations are patent. Combined carotid and vertebral artery surgery is effective in well selected cases, and it does not enhance the risk of the two operations performed separately. It also eliminate the possibility of failure of isolated carotid revascularization for vertebrobasilar symptoms.

  2. Vertebral column deformities in farmed rainbow trout ( Oncorhynchus mykiss )

    DEFF Research Database (Denmark)

    Madsen, Lone; Dalsgaard, Inger

    1999-01-01

    of deformities (4.8%). In all groups examined, the deformities were spread over the whole vertebral column. The deformities in the group fed the low vitamin C diet were more severe than those found in the other groups. An outbreak of the disease rainbow trout fry syndrome (RTFS) caused by the bacterium...

  3. Roles of vertebrate aquaglyceroporins in arsenic transport and detoxification.

    Science.gov (United States)

    Liu, Zijuan

    2010-01-01

    Aquaporins are important channel proteins that are responsible for the balance of cellular osmolarity and nutrient transport in vertebrates. Recently, new functions of these ancient channels have been found in the conduction of metalloid arsenic (As). Chronic As exposure through contaminated water and food sources is associated with multiple human diseases and endangers millions of people's health worldwide. Therefore, identification of the As transport pathways is necessary to elucidate the mechanisms of As carcinogenesis. Arsenic detoxification systems have been studied in multiple vertebrates such as mammalian mouse, rat, humans and nonmammalian vertebrates. Multiple transporters and enzymes have been shown to be involved in As translocation and cellular transformation. In these vertebrates, members ofaquaglyceroporins, which include AQP7 in kidney and AQP9 in liver, catalyze uptake of inorganic trivalent arsenite [As(III)]. AQP9, the major liver aquaglyceroporin, conducts both inorganic As(III) and organic monomethylarsonous acid [MMA(III)], an intermediate that is generated during the cellular methylation. As a channel that facilitates a downhill movement of substances dependent on the concentration gradient, AQP9 may play an important role in the simultaneous influx of inorganic As(III) from blood to liver and efflux of As metabolite MMA(III) from liver to blood. In this chapter, we will discuss the function ofaquaglyceroporins ofvertebrates in uptake and detoxification of the metalloid As.

  4. Vertebral artery dissection associated with generalized convulsive seizures

    DEFF Research Database (Denmark)

    Amin, Faisal Mohammad; Larsen, Vibeke Andrée; Tfelt-Hansen, Peer

    2013-01-01

    showed a left-sided pontine infarction, an infarct in the left cerebellar hemisphere and a right vertebral artery dissection (VAD). The patient was treated with heparin and an oral anticoagulant for 6 months. Recovery of neurologic function was excellent. In patients with symptoms of disturbances...

  5. LncRNAs in vertebrates: advances and challenges.

    Science.gov (United States)

    Mallory, Allison C; Shkumatava, Alena

    2015-10-01

    Beyond the handful of classic and well-characterized long noncoding RNAs (lncRNAs), more recently, hundreds of thousands of lncRNAs have been identified in multiple species including bacteria, plants and vertebrates, and the number of newly annotated lncRNAs continues to increase as more transcriptomes are analyzed. In vertebrates, the expression of many lncRNAs is highly regulated, displaying discrete temporal and spatial expression patterns, suggesting roles in a wide range of developmental processes and setting them apart from classic housekeeping ncRNAs. In addition, the deregulation of a subset of these lncRNAs has been linked to the development of several diseases, including cancers, as well as developmental anomalies. However, the majority of vertebrate lncRNA functions remain enigmatic. As such, a major task at hand is to decipher the biological roles of lncRNAs and uncover the regulatory networks upon which they impinge. This review focuses on our emerging understanding of lncRNAs in vertebrate animals, highlighting some recent advances in their functional analyses across several species and emphasizing the current challenges researchers face to characterize lncRNAs and identify their in vivo functions.

  6. The Characterization and Manipulation of the Reticulated Microbiome in Vertebrates

    DEFF Research Database (Denmark)

    Roggenbuck, Michael

    the tissue and easies the birds to feed large carrions. However, feeding on carcass is associated to the potential exposure of bacterial toxins, with severe outcome such as avian botulism. As Ley et al (2008) described – diet is the key driver of microbial composition of the digestive system in vertebrates...

  7. Testing the evolutionary conservation of vocal motoneurons in vertebrates.

    Science.gov (United States)

    Albersheim-Carter, Jacob; Blubaum, Aleksandar; Ballagh, Irene H; Missaghi, Kianoush; Siuda, Edward R; McMurray, George; Bass, Andrew H; Dubuc, Réjean; Kelley, Darcy B; Schmidt, Marc F; Wilson, Richard J A; Gray, Paul A

    2016-04-01

    Medullary motoneurons drive vocalization in many vertebrate lineages including fish, amphibians, birds, and mammals. The developmental history of vocal motoneuron populations in each of these lineages remains largely unknown. The highly conserved transcription factor Paired-like Homeobox 2b (Phox2b) is presumed to be expressed in all vertebrate hindbrain branchial motoneurons, including laryngeal motoneurons essential for vocalization in humans. We used immunohistochemistry and in situ hybridization to examine Phox2b protein and mRNA expression in caudal hindbrain and rostral spinal cord motoneuron populations in seven species across five chordate classes. Phox2b was present in motoneurons dedicated to sound production in mice and frogs (bullfrog, African clawed frog), but not those in bird (zebra finch) or bony fish (midshipman, channel catfish). Overall, the pattern of caudal medullary motoneuron Phox2b expression was conserved across vertebrates and similar to expression in sea lamprey. These observations suggest that motoneurons dedicated to sound production in vertebrates are not derived from a single developmentally or evolutionarily conserved progenitor pool.

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

    Science.gov (United States)

    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.

  9. Sensors and signal transduction pathways in vertebrate cell volume regulation

    DEFF Research Database (Denmark)

    Hoffmann, Else K; Pedersen, Stine F

    2006-01-01

    will be discussed. In contrast to the simple pathway of osmosensing in yeast, cells from vertebrate organisms appear to exhibit multiple volume sensing systems, the specific mechanism(s) activated being cell type- and stimulus-dependent. Candidate sensors include integrins and growth factor receptors, while other...

  10. Osteoimmunological Insight in to Vertebral Fractures in Osteoporosis

    Directory of Open Access Journals (Sweden)

    H Saghafi

    2008-11-01

    Full Text Available Background: The aim of this study was to investigate the relationship among circulating levels of OPG, RANKL, cytokine profiles, bone mineral density (BMD and vertebral fractures in pre and postmenopausal women and comparing these find­ing in three groups including osteoporotic patients with and without fracture and healthy women."nMethods: In a cross-sectional study, 215 women who attended the BMD unit of Endocrinology & Metabolism Research Center (EMRC of Tehran University of medical sciences were recruited. Serum Osteoporotegerin and sRANKL were measured. In addition, cytokines profile evaluated. Lumbar radiographs in the antero-posterior and left lateral projections were acquired following a standardized protocol and bone mineral densitometry was performed."nResults: In X-ray study, 65.2% of postmenopausal women and 34.8% of pre menopausal women had at least one vertebral fracture (P= 0.04. Serum OPG and TNFα concentration significantly correlated with age (OPG: P= 0.001, r= 0.22, TNFα: P=0.04, r= 0.15. In logistic regression model, RANKL/OPG ratio independent of age and BMD was predicted vertebral fractures."nConclusion: Osteoimmunological insight in to vertebral fracture indicated that important role of proinflammatory cytokines and RANKL/OPG pathway in bone remodeling.

  11. Facultative parthenogenesis in a critically endangered wild vertebrate.

    Science.gov (United States)

    Fields, Andrew T; Feldheim, Kevin A; Poulakis, Gregg R; Chapman, Demian D

    2015-06-01

    Facultative parthenogenesis - the ability of sexually reproducing species to sometimes produce offspring asexually - is known from a wide range of ordinarily sexually reproducing vertebrates in captivity, including some birds, reptiles and sharks [1-3]. Despite this, free-living parthenogens have never been observed in any of these taxa in the wild, although two free-living snakes were recently discovered each gestating a single parthenogen - one copperhead (Agkistrodon contortrix) and one cottonmouth (Agkistrodon piscivorus) [1]. Vertebrate parthenogens are characterized as being of the homogametic sex (e.g., females in sharks, males in birds) and by having elevated homozygosity compared to their mother [1-3], which may reduce their viability [4]. Although it is unknown if either of the parthenogenetic snakes would have been carried to term or survived in the wild, facultative parthenogenesis might have adaptive significance [1]. If this is true, it is reasonable to hypothesize that parthenogenesis would be found most often at low population density, when females risk reproductive failure because finding mates is difficult [5]. Here, we document the first examples of viable parthenogens living in a normally sexually reproducing wild vertebrate, the smalltooth sawfish (Pristis pectinata). We also provide a simple approach to screen any microsatellite DNA database for parthenogens, which will enable hypothesis-driven research on the significance of vertebrate parthenogenesis in the wild.

  12. Bilobate anterior epidural extension of vertebral lesion : MRI features

    Energy Technology Data Exchange (ETDEWEB)

    Park, Dong Woo; Lee, Chae Guk [Pusan Paik Hospital, Pusan (Korea, Republic of)

    1994-11-15

    To determine the value of bilobate anterior epidrual extension(AEE) on MRI in differential diagnosis of tuberculous spondylitis, pyogenic spondylitis and malignant tumor. SE T1-, T2- and Gd-DTPA enhanced T1-weighted, sagittal and axial MR images of 39 patients(40 vertebral lesions), including 16 tuberculous spondylitis, 7 pyogenic spondylitis(8 lesions, consisting of 2 separate lesion of 1 patient), and 16 malignant vertebral tumors(15 metastases, 1 lymphoma) with an AEE were reviewed. The frequency of bilobate AEE shown as double-convexity in the anterior epidural space on axial scans was evaluated in the above vertebral diseases. The bilobate AEE on the axial scans was seen in 12 out of the 16 tuberculous spondylitis(75%) and 1 out of 8 pyogenic spondylitis(13%), and 10 out of the 16 malignant tumor including 15 metastasis and 1 lymphoma(63%). The bilobate AEE of vertebral lesions is suggestive of tuberculous spondylitis or malignant tumor rather than pyogenic spondylitis. This pattern seems to be related with the preservation of the structures, including midline septum, PLL(Posterior longitudinal ligament), lateral membrane and fibrous membrane, limiting and surrounding the extension of the tuberculous spondylitis and malignant tumor, and with the early penetration or disruption of PLL, midline septum, lateral and fibrous membranes in the pyogenic spondylitis.

  13. DNA Methylation, Epigenetics, and Evolution in Vertebrates: Facts and Challenges

    Directory of Open Access Journals (Sweden)

    Annalisa Varriale

    2014-01-01

    Full Text Available DNA methylation is a key epigenetic modification in the vertebrate genomes known to be involved in biological processes such as regulation of gene expression, DNA structure and control of transposable elements. Despite increasing knowledge about DNA methylation, we still lack a complete understanding of its specific functions and correlation with environment and gene expression in diverse organisms. To understand how global DNA methylation levels changed under environmental influence during vertebrate evolution, we analyzed its distribution pattern along the whole genome in mammals, reptiles and fishes showing that it is correlated with temperature, independently on phylogenetic inheritance. Other studies in mammals and plants have evidenced that environmental stimuli can promote epigenetic changes that, in turn, might generate localized changes in DNA sequence resulting in phenotypic effects. All these observations suggest that environment can affect the epigenome of vertebrates by generating hugely different methylation patterns that could, possibly, reflect in phenotypic differences. We are at the first steps towards the understanding of mechanisms that underlie the role of environment in molding the entire genome over evolutionary times. The next challenge will be to map similarities and differences of DNA methylation in vertebrates and to associate them with environmental adaptation and evolution.

  14. Vertebral osteomyelitis associated with cat-scratch disease

    NARCIS (Netherlands)

    Hulzebos, CV; Koetse, HA; Kimpen, JLL; Wolfs, TFW

    1999-01-01

    We describe a patient with vertebral osteomyelitis and paravertebral soft-tissue collections associated with cat-scratch disease (CSD). Diagnosis was established on the basis of histologic examination and serological and polymerase chain reaction (PCR) tests. Treatment consisted of administration of

  15. The MRI appearances of early vertebral osteomyelitis and discitis

    Energy Technology Data Exchange (ETDEWEB)

    Dunbar, J.A.T.; Sandoe, J.A.T. [Department of Microbiology, Leeds General Infirmary, Leeds LS1 3EX (United Kingdom); Rao, A.S. [Department of Orthopaedics, Leeds General Infirmary, Leeds LS1 3EX (United Kingdom); Crimmins, D.W. [Department of Neurosurgery, Leeds General Infirmary, Leeds LS1 3EX (United Kingdom); Baig, W. [Department of Cardiology, Leeds General Infirmary, Leeds LS1 3EX (United Kingdom); Rankine, J.J., E-mail: james.rankine@leedsth.nhs.u [Department of Radiology, Leeds General Infirmary, Leeds LS1 3EX (United Kingdom); Leeds Musculoskeletal Biomedical Research Unit, Leeds (United Kingdom)

    2010-12-15

    Aim: To describe the magnetic resonance imaging (MRI) appearances in patients with a clinical history suggestive of vertebral osteomyelitis and discitis who underwent MRI very early in their clinical course. Materials and methods: A retrospective review of the database of spinal infections from a spinal microbiological liaison team was performed over a 2 year period to identify cases with clinical features suggestive of spinal infection and an MRI that did not show features typical of vertebral osteomyelitis and discitis. All patients had positive microbiology and a follow up MRI showing typical features of spinal infection. Results: In four cases the features typical of spinal infection were not evident at the initial MRI. In three cases there was very subtle endplate oedema associated with disc degeneration, which was interpreted as Modic type I degenerative endplate change. Intravenous antibiotic therapy was continued prior to repeat MRI examinations. The mean time to the repeat examination was 17 days with a range of 8-22 days. The second examinations clearly demonstrated vertebral osteomyelitis and discitis. Conclusion: Although MRI is the imaging method of choice for vertebral osteomyelitis and discitis in the early stages, it may show subtle, non-specific endplate subchondral changes; a repeat examination may be required to show the typical features.

  16. Trends in Children's Concepts of Vertebrate and Invertebrate.

    Science.gov (United States)

    Braund, Martin

    1998-01-01

    Presents the results of a cross-age study of 7- to 15-year-old children on their thinking about vertebrate and invertebrate animals. Suggests experiences that could be included in the school science curriculum and argues for more classroom work relating structure with function in order to address students' conceptual difficulties. (Contains 18…

  17. Case report on vertebral artery dissection in mixed martial arts.

    Science.gov (United States)

    Slowey, Michael; Maw, Graeme; Furyk, Jeremy

    2012-04-01

    A 41-year-old man presented to the ED with severe vertigo 2 days after a grappling injury while training in mixed martial arts. Imaging revealed a cerebellar infarct with complete occlusion of the right vertebral artery secondary to dissection. Management options are discussed as is the ongoing controversy regarding the safety of the sport.

  18. Cell to cell signalling during vertebrate limb bud development

    NARCIS (Netherlands)

    Panman, Lia

    2004-01-01

    Communication between cells is essential during embryonic development. The vertebrate limb bud provides us a model to study signalling interactions between cells during patterning of embryonic tissues and organogenesis. In chapter 1 I give an introduction about limb bud development that is focussed

  19. The Evolution and Ecology of Cooperative Breeding in Vertebrates

    NARCIS (Netherlands)

    Komdeur, Jan; Eikenaar, Cas; Brouwer, Lyanne; Richardson, David S.

    2008-01-01

    Cooperative breeding – in which some adults forgo independent breeding and remain as subordinates within a group helping to raise the offspring of others – occurs in between 3% and 10% of vertebrates. The structure of such systems varies greatly, from pairs with helpers-at-the-nest to communal breed