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Sample records for rare hemiparasitic plant

  1. Interactions between hemiparasitic plants and their hosts

    PubMed Central

    Plavcová, Lenka; Cameron, Duncan D

    2010-01-01

    Hemiparasitic plants display a unique strategy of resource acquisition combining parasitism of other species and own photosynthetic activity. Despite the active photoassimilation and green habit, they acquire substantial amount of carbon from their hosts. The organic carbon transfer has a crucial influence on the nature of the interaction between hemiparasites and their hosts which can oscillate between parasitism and competition for light. In this minireview, we summarize methodical approaches and results of various studies dealing with carbon budget of hemiparasites and the ecological implications of carbon heterotrophy in hemiparasites. PMID:20729638

  2. Using Small-Scale Studies to Prioritize Threats and Guide Recovery of a Rare Hemiparasitic Plant: Cordylanthus rigidus ssp. littoralis

    PubMed Central

    Watts, Sean M.; Uhl, Melissa M.; Maurano, Stephen P.; Nuccio, Erin E.

    2010-01-01

    Background Recovering endangered species would benefit from identifying and ranking of the factors that threaten them. Simply managing for multiple positive influences will often aid in recovery; however, the relative impacts of multiple threats and/or interactions among them are not always predictable. We used a series of experiments and quantitative observational studies to examine the importance of five potential limiting factors to the abundance of a state-listed endangered hemiparasitic annual forb, Cordylanthus rigidus ssp. littoralis (C.r.l., California, USA): host availability, mammalian herbivores, insect seed predators, fire suppression, and exotic species. While this initial assessment is certainly not a complete list, these factors stem from direct observation and can inform provisional recommendations for management and further research. Methodology and Principal Findings Studies were conducted at five sites and included assessments of the influence of host availability, exotic species, exclusion of mammalian herbivores and insect seed predators on C.r.l. productivity, and simulated effects of fire on seed germination. C.r.l. was limited by multiple threats: individuals with access to host species produced up to three times more inflorescences than those lacking hosts, mammalian herbivory reduced C.r.l. size and fecundity by more than 50% and moth larvae reduced seed production by up to 40%. Litter deposition and competition from exotic plant species also appears to work in conjunction with other factors to limit C.r.l. throughout its life cycle. Conclusions and Significance The work reported here highlights the contribution that a series of small-scale studies can make to conservation and restoration. Taken as a whole, the results can be used immediately to inform current management and species recovery strategies. Recovery of C.r.l. will require management that addresses competition with exotic plant species, herbivore pressure, and availability of

  3. Using small-scale studies to prioritize threats and guide recovery of a rare hemiparasitic plant: Cordylanthus rigidus ssp. littoralis.

    PubMed

    Watts, Sean M; Uhl, Melissa M; Maurano, Stephen P; Nuccio, Erin E

    2010-01-26

    Recovering endangered species would benefit from identifying and ranking of the factors that threaten them. Simply managing for multiple positive influences will often aid in recovery; however, the relative impacts of multiple threats and/or interactions among them are not always predictable. We used a series of experiments and quantitative observational studies to examine the importance of five potential limiting factors to the abundance of a state-listed endangered hemiparasitic annual forb, Cordylanthus rigidus ssp. littoralis (C.r.l., California, USA): host availability, mammalian herbivores, insect seed predators, fire suppression, and exotic species. While this initial assessment is certainly not a complete list, these factors stem from direct observation and can inform provisional recommendations for management and further research. Studies were conducted at five sites and included assessments of the influence of host availability, exotic species, exclusion of mammalian herbivores and insect seed predators on C.r.l. productivity, and simulated effects of fire on seed germination. C.r.l. was limited by multiple threats: individuals with access to host species produced up to three times more inflorescences than those lacking hosts, mammalian herbivory reduced C.r.l. size and fecundity by more than 50% and moth larvae reduced seed production by up to 40%. Litter deposition and competition from exotic plant species also appears to work in conjunction with other factors to limit C.r.l. throughout its life cycle. The work reported here highlights the contribution that a series of small-scale studies can make to conservation and restoration. Taken as a whole, the results can be used immediately to inform current management and species recovery strategies. Recovery of C.r.l. will require management that addresses competition with exotic plant species, herbivore pressure, and availability of preferred host species.

  4. Interactive effects of mycorrhizae and a root hemiparasite on plant community productivity and diversity.

    PubMed

    Stein, Claudia; Rissmann, Cornelia; Hempel, Stefan; Renker, Carsten; Buscot, François; Prati, Daniel; Auge, Harald

    2009-02-01

    Plant communities can be affected both by arbuscular mycorrhizal fungi (AMF) and hemiparasitic plants. However, little is known about the interactive effects of these two biotic factors on the productivity and diversity of plant communities. To address this question, we set up a greenhouse study in which different AMF inocula and a hemiparasitic plant (Rhinanthus minor) were added to experimental grassland communities in a fully factorial design. In addition, single plants of each species in the grassland community were grown with the same treatments to distinguish direct AMF effects from indirect effects via plant competition. We found that AMF changed plant community structure by influencing the plant species differently. At the community level, AMF decreased the productivity by 15-24%, depending on the particular AMF treatment, mainly because two dominant species, Holcus lanatus and Plantago lanceolata, showed a negative mycorrhizal dependency. Concomitantly, plant diversity increased due to AMF inoculation and was highest in the treatment with a combination of two commercial AM strains. AMF had a positive effect on growth of the hemiparasite, and thereby induced a negative impact of the hemiparasite on host plant biomass which was not found in non-inoculated communities. However, the hemiparasite did not increase plant diversity. Our results highlight the importance of interactions with soil microbes for plant community structure and that these indirect effects can vary among AMF treatments. We conclude that mutualistic interactions with AMF, but not antagonistic interactions with a root hemiparasite, promote plant diversity in this grassland community.

  5. Hemiparasitic plant impacts animal and plant communities across four trophic levels.

    PubMed

    Hartley, S E; Green, P; Massey, F P; Press, M C P; Stewart, J A; John, E A

    2015-09-01

    Understanding the impact of species on community structure is a fundamental question in ecology. There is a growing body of evidence that suggests that both subdominant species and parasites can have disproportionately large effects on other organisms. Here we report those impacts for a species that is both subdominant and parasitic, the hemiparasite Rhinanthus minor. While the impact of parasitic angiosperms on their hosts and, to a lesser degree, coexisting plant species, has been well characterized, much less is known about their effects on higher trophic levels: We experimentally manipulated field densities of the hemiparasite Rhinanthus minor in a species-rich grassland, comparing the plant and invertebrate communities in plots where it was removed, present at natural densities, or present at enhanced densities. Plots with natural and enhanced densities of R. minor had lower plant biomass than plots without the hemiparasite, but enhanced densities almost doubled the abundance of invertebrates within the plots across all trophic levels, with effects evident in herbivores, predators, and detritivores. The hemiparasite R. minor, despite being a subdominant and transient component within plant communities that it inhabits, has profound effects on four different trophic levels. These effects persist beyond the life of the hemiparasite, emphasizing its role as a keystone species in grassland communities.

  6. Effects of two contrasting hemiparasitic plant species on biomass production and nitrogen availability.

    PubMed

    Demey, Andreas; Ameloot, Els; Staelens, Jeroen; De Schrijver, An; Verstraeten, Gorik; Boeckx, Pascal; Hermy, Martin; Verheyen, Kris

    2013-09-01

    Hemiparasitic plants can substantially change plant community structure; the drainage of host resources has a direct negative effect on host biomass and, as a consequence, promotes non-host biomass production (parasitism pathway); on the other hand, hemiparasitic litter inputs can enhance nutrient cycling which may have an indirect positive effect on both host and non-host biomass production (litter pathway). We evaluated the net effect of both pathways on total shoot biomass (with and without the hemiparasite) and shoot biomass of graminoids, forbs and ericaceous shrubs using a removal experiment in three sites infested with the annual Rhinanthus angustifolius, and three sites infested with the biennial Pedicularis sylvatica. We addressed the potential importance of litter effects by determination of litter quantity and quality, as well as modeling N release during decomposition. In the second year after removing the hemiparasites, total plant biomass at Rhinanthus sites was 24 % higher in weeded plots than in control plots, while weeding had no significant effect at Pedicularis sites. The increase in total biomass following Rhinanthus removal was mainly due to a higher biomass of graminoids. The amount of litter produced by Rhinanthus was only half of that produced by Pedicularis; N contents were similar. The amount of N in the litter was 9 and 30 % of the amount removed by mowing for Rhinanthus and Pedicularis sites, respectively. Within 2 months, about 45 % of the N in both hemiparasitic litter types was released by decomposition. Our results suggest that in addition to the suppression of host biomass due to parasitism, positive litter feedbacks on host and non-host biomass-via an increase in nutrient availability-also affect plant community structure. We propose that, depending on the particular hemiparasite and/or site conditions, these positive litter feedbacks on shoot biomass can compensate for the negative effect of parasitism.

  7. Host Range and Selectivity of the Hemiparasitic Plant Thesium chinense (Santalaceae)

    PubMed Central

    Suetsugu, Kenji; Kawakita, Atsushi; Kato, Makoto

    2008-01-01

    Background and Aims Thesium chinense is a hemiparasitic plant that is common in grassland habitats of eastern Asia. Although the physiology of Thesium has been well studied in attempts to control its weedy habit, there have been few ecological investigations of its parasitic life history. Thesium chinense is thought to parasitize species of Poaceae, but evidence remains circumstantial. Methods A vegetation survey was conducted to test whether any plant species occurs significantly more often in plots with T. chinense than expected. In addition, haustorial connections were examined directly by excavating the roots and post-attachment host selectivity was evaluated by comparing the observed numbers of haustoria on different hosts against those expected according to the relative below-ground biomass. Haustorium sizes were also compared among host species. Key Results Only two of the 38 species recorded, Lespedeza juncea and Eragrostis curvula, occurred more often in plots with Thesium than expected. In contrast to this, T. chinense parasitized 22 plant species in 11 families, corresponding to 57·9 % of plant species found at the study site. Haustoria were non-randomly distributed among host species, suggesting that there is some post-attachment host selectivity. Thesium chinense generally preferred the Poaceae, although haustoria formed on the Fabaceae were larger than those on other hosts. Conclusions This is the first quantitative investigation of the host range and selectivity of hemiparasitic plants of the Santalales. The preference for Fabaceae as hosts may be linked to the greater nutrient availability in these nitrogen-fixing plants. PMID:18492736

  8. Hemiparasite--host plant interactions in a fragmented landscape assessed via imaging spectroscopy and LiDAR.

    PubMed

    Barbosa, Jomar M; Sebástian-González, Esther; Asner, Gregory P; Knapp, David E; Anderson, Christopher; Martin, Roberta E; Dirzo, Rodolfo

    2016-01-01

    Species interactions are susceptible to anthropogenic changes in ecosystems, but this has been poorly investigated in a spatially explicit manner in the case of plant parasitism, such as the omnipresent hemiparasitic mistletoe-host plant interactions. Analyzing such interactions at a large spatial scale may advance our understanding of parasitism patterns over complex landscapes. Combining high-resolution airborne imaging spectroscopy and LiDAR, we studied hemiparasite incidence within and among tree host stands to examine the prevalence and spatial distribution of hemiparasite load in ecosystems. Specifically, we aimed to assess: (1) detection accuracy of mistletoes on their oak hosts; (2) hemiparasitism prevalence within host tree canopies depending on tree height, and (3) spatial variation in hemiparasitism across fragmented woodlands, in a low-diversity mediterranean oak woodland in California, USA. We identified mistletoe infestations with 55-96% accuracy, and detected significant differences in remote-sensed spectra between oak trees with and without mistletoe infestation. We also found that host canopy height had little influence on infestation degree, whereas landscape-level variation showed consistent; non-random patterns: isolated host trees had twice the infestation load than did trees located at the core of forest fragments. Overall, we found that canopy exposure (i.e., lower canopy density or proximity to forest edge) is more important than canopy height for mistletoe infestation, and that by changing landscape structure, parasitic prevalence increased with woodland fragmentation. We conclude that reducing fragmentation in oak woodlands will minimize anthropogenic impact on mistletoe infestation at the landscape level. We argue that advanced remote sensing technology can provide baselines to quantitatively analyze and monitor parasite-host trajectories in light of global environmental change, and that this is a promising approach to be further tested

  9. Nutrient requirements differ in two Pedicularis species in the absence of a host plant: implication for driving forces in the evolution of host preference of root hemiparasitic plants.

    PubMed

    Li, Ai-Rong; Li, Yun-Ju; Smith, Sally E; Smith, F Andrew; Guan, Kai-Yun

    2013-10-01

    Facultative root hemiparasitic plants generally have a wide host range, but in most cases show an obvious host preference. The reasons for the marked difference in growth performance of hemiparasites when attached to different hosts are not fully understood. In this study, the hypothesis was tested that hemiparasites showing a preference for different hosts have different nutrient requirements. Two facultative root hemiparasitic Pedicularis species (P. rex and P. tricolor) with a different host dependency and preference were used to test their responses to inorganic solutes. The effects of nitrogen, phosphorus and potassium on growth of the hemiparasitic plants not attached to a host were determined, using an orthogonal design in pot cultivation under greenhouse conditions. Variables including biomass, shoot nutrient concentration, root:shoot (R:S) ratios and the number of haustoria were measured. As in autotrophic plants, nutrient deficiency reduced dry weight (DW) and nutrient concentrations in the root hemiparasites. Nitrogen and phosphorus significantly influenced growth of both Pedicularis species, while potassium availability influenced only shoot DW of P. rex. Nitrogen had far more effect on growth of P. rex than on P. tricolor, while phosphorus deficiency caused more marked growth depression in P. tricolor than in P. rex. Pedicularis rex grew faster than P. tricolor in a range of nutrient supplies. Different patterns of biomass allocation between the two Pedicularis species were observed. While P. rex invested more into roots (particularly fine rootlets) than P. tricolor, the number of haustoria produced by P. rex was relatively much lower than that produced by P. tricolor, which had a much smaller root system. The two Pedicularis species differ in nutrient requirements and biomass allocation. Distinct interspecific traits in growth and nutrient requirements can be driving forces for the differential interactions between hemiparasites and their hosts.

  10. Nutrient requirements differ in two Pedicularis species in the absence of a host plant: implication for driving forces in the evolution of host preference of root hemiparasitic plants

    PubMed Central

    Li, Ai-Rong; Li, Yun-Ju; Smith, Sally E.; Smith, F. Andrew; Guan, Kai-Yun

    2013-01-01

    Background and Aims Facultative root hemiparasitic plants generally have a wide host range, but in most cases show an obvious host preference. The reasons for the marked difference in growth performance of hemiparasites when attached to different hosts are not fully understood. In this study, the hypothesis was tested that hemiparasites showing a preference for different hosts have different nutrient requirements. Methods Two facultative root hemiparasitic Pedicularis species (P. rex and P. tricolor) with a different host dependency and preference were used to test their responses to inorganic solutes. The effects of nitrogen, phosphorus and potassium on growth of the hemiparasitic plants not attached to a host were determined, using an orthogonal design in pot cultivation under greenhouse conditions. Variables including biomass, shoot nutrient concentration, root:shoot (R:S) ratios and the number of haustoria were measured. Key Results As in autotrophic plants, nutrient deficiency reduced dry weight (DW) and nutrient concentrations in the root hemiparasites. Nitrogen and phosphorus significantly influenced growth of both Pedicularis species, while potassium availability influenced only shoot DW of P. rex. Nitrogen had far more effect on growth of P. rex than on P. tricolor, while phosphorus deficiency caused more marked growth depression in P. tricolor than in P. rex. Pedicularis rex grew faster than P. tricolor in a range of nutrient supplies. Different patterns of biomass allocation between the two Pedicularis species were observed. While P. rex invested more into roots (particularly fine rootlets) than P. tricolor, the number of haustoria produced by P. rex was relatively much lower than that produced by P. tricolor, which had a much smaller root system. Conclusions The two Pedicularis species differ in nutrient requirements and biomass allocation. Distinct interspecific traits in growth and nutrient requirements can be driving forces for the differential

  11. Localized Hormone Fluxes and Early Haustorium Development in the Hemiparasitic Plant Triphysaria versicolor1

    PubMed Central

    Tomilov, Alexey A.; Tomilova, Natalia B.; Abdallah, Ibrahim; Yoder, John I.

    2005-01-01

    Perhaps the most obvious phenotypes associated with chemical signaling between plants are manifested by parasitic species of Orobanchaceae. The development of haustoria, invasive root structures that allow hemiparasitic plants to transition from autotrophic to heterotrophic growth, is rapid, highly synchronous, and readily observed in vitro. Haustorium development is initiated in aseptic roots of the facultative parasite Triphysaria versicolor when exposed to phenolic molecules associated with host root exudates and rhizosphere bioactivity. Morphological features of early haustorium ontogeny include rapid cessation of root elongation, expansion, and differentiation of epidermal cells into haustorial hairs, and cortical cell expansion. These developmental processes were stimulated in aseptic T. versicolor seedlings by the application of exogenous phytohormones and inhibited by the application of hormone antagonists. Surgically dissected root tips formed haustoria if the root was exposed to haustorial-inducing factors prior to dissection. In contrast, root tips that were dissected prior to inducing-factor treatment were unable to form haustoria unless supplemented with indole-3-acetic acid. A transient transformation assay demonstrated that auxin and ethylene-responsive promoters were up-regulated when T. versicolor was exposed to either exogenous hormones or purified haustoria-inducing factors. These experiments demonstrate that localized auxin and ethylene accumulation are early events in haustorium development and that parasitic plants recruit established plant developmental mechanisms to realize parasite-specific functions. PMID:15965023

  12. Diversity of endophytic fungi associated with the foliar tissue of a hemi-parasitic plant Macrosolen cochinchinensis.

    PubMed

    Zhou, Sheng-Liang; Yan, Shu-Zhen; Liu, Qi-Sha; Chen, Shuang-Lin

    2015-01-01

    Foliar fungal endophytes are an important plant-associated fungal group. However, little is known about these fungi in hemi-parasitic plants, a unique plant group which derive nutrients from living plants of its hosts by haustoria while are photosynthetic to some degree. In this paper, the endophytic fungi in the leaves of a species of hemi-parasitic plant, Macrosolen cochinchinensis, were studied by both culture-dependent and culture-independent methods. By culture-dependent method, a total of 511 isolates were recovered from 452 of 600 leaf fragments (colonization rate = 75.3 %) and were identified to be 51 taxa. Valsa sp. was the most abundant (relative abundance = 38.4 %), followed by Cladosporium sp. 1 (13.5 %), Ulocladium sp. (4.3 %), Phomopsis sp. 2 (3.7 %), Hendersonia sp. (3.5 %), and Diaporthe sp. 4 (3.5 %). The Shannon index (H') of the isolated endophytic fungi was 2.628, indicating a moderate diversity. By culture-independent method, Aspergillus spp., Cladosporium sp., Mycosphaerella sp., Acremonium strictum, and Tremella sp. were detected. To our knowledge, the Tremella species have never been detected as endophytes so far. In addition, a cloned sequence was not similar with any current sequence in the Genbank, which may represent a novel species. Altogether, this study documented endophytic fungal assemble in the leaves of M. cochinchinensis which was worthy of our attention, and may expand our knowledge about endophytic fungi within the photosynthetic tissues of plants.

  13. Where are you sucking from? Using Stable Isotopes to understand Host Specificity in two Hemiparasitic plants above the tree line in Northern Sweden

    NASA Astrophysics Data System (ADS)

    Macias Sevde, A. S.

    2012-12-01

    By Alejandro Macias, Erik Hobbie, Ruth Varner, Kaitlyn Steele Hemiparasites are known to suck nutrients from nearby plants but their host specificity is not well understood. Hemiparasites are ecosystem engineers, limiting surrounding plant's growth, and decreasing local biodiversity. To better understand this phenomenon, the host specificities of two hemiparasitic angiosperms, Bartsia alpina , and Pedicularis lapponica were studied above the tree line along an elevational gradient in Sweden. B. alpina specialized in wetter environments, as indicated by their higher δ13C signature, and their growth among Salixsp.Betula nana, Bistorta vivipara, Viola biflora, Geranium sp., and Trollious europaeus. P. lapponica was common in drier, less species rich environments, known as heaths, where B. nana, Empetrum negrum, Phyllodoce coeruela, Vaccinium myrtillus and Vaccinium vitis-idaea are the most common species. P. lapponica had higher foliage δ13C due to its better water-use efficiency in a dry environment. Field survey data and δN15 values of both the foliage of the parasitic plants and their potential hosts were used to determine host specificity. Since the δN15 value of the hemiparasitic plant and its host are similar due to parasitism, it was determined that P. lapponica had a preference for plants with an ericoid mycorrhizal association, such as Vaccinium sp, and E. negrum, but not for the common P. coeruela. This does not support the idea found in the literature that P. lapponica has a preference for grasses. B. alpina was less host specific, associating with non-mycorrhizal, ericoid, and ectomycorhizal plants, such as Carex sp, Vaccinium sp., and S. lapponum. The ectomycorrhizal species, Salix sp., and B. nana, were both potential hosts for B. alpina and P. lapponica due to their presence among them. However, the isotopic data revealed that B. alpina had a preference for Salix sp., and P. lapponica had a preference for B. nana.

  14. Sea change under climate change: case studies in rare plant conservation from the dynamic San Francisco Estuary

    USDA-ARS?s Scientific Manuscript database

    We present case studies supporting management of two rare plant species in tidal wetlands of the San Francisco Estuary. For an annual hemiparasite, we used demographic analyses to identify factors to enhance population establishment, survivorship and fitness, and to compare reintroduced with natura...

  15. Hemiparasites generate environmental heterogeneity and enhance species coexistence in salt marshes.

    PubMed

    Grewell, Brenda J

    2008-07-01

    Tidal inundation and salinity are considered to be controlling factors in salt marsh species distributions. Parasitic plants may also influence community organization as parasite-host interactions may play a functional role in stress amelioration due to physiological mechanisms for salinity tolerance and resource acquisition. Endangered root hemiparasites (Cordylanthus maritimus ssp. palustris and Cordylanthus mollis ssp. mollis) occupy unique habitat within fragmented northern California tidal wetlands. My objective was to examine the effects of these root hemiparasites on soil salinity, aeration, and community composition. I compared experimentally established bare patches, shaded and unshaded, and parasite removal patches to controls with hemiparasites across intertidal elevation gradients. Plant community composition, soil salinity, and redox potential were measured as response variables. In this field removal experiment, I demonstrated that parasite-host associations can enhance the amelioration of physical stress conditions in the salt marsh exceeding the passive role of shading by vegetation. Consumer-driven reduction of physical stress resulted in increased plant species richness, and the effect was most pronounced with elevated salinity and hypoxia stress. Although previous studies have demonstrated that removal of dominant plant biomass by herbivores can increase physical stress in salt marshes, this is one of the first examples of a positive indirect effect of a consumer on community diversity through physical stress relief. Greater understanding of biological interactions coupled with abiotic factors may improve rare plant conservation and salt marsh restoration success.

  16. Evolution of plastid gene rps2 in a lineage of hemiparasitic and holoparasitic plants: Many losses of photosynthesis and complex patterns of rate variation

    PubMed Central

    dePamphilis, Claude W.; Young, Nelson D.; Wolfe, Andrea D.

    1997-01-01

    The plastid genomes of some nonphotosynthetic parasitic plants have experienced an extreme reduction in gene content and an increase in evolutionary rate of remaining genes. Nothing is known of the dynamics of these events or whether either is a direct outcome of the loss of photosynthesis. The parasitic Scrophulariaceae and Orobanchaceae, representing a continuum of heterotrophic ability ranging from photosynthetic hemiparasites to nonphotosynthetic holoparasites, are used to investigate these issues. We present a phylogenetic hypothesis for parasitic Scrophulariaceae and Orobanchaceae based on sequences of the plastid gene rps2, encoding the S2 subunit of the plastid ribosome. Parasitic Scrophulariaceae and Orobanchaceae form a monophyletic group in which parasitism can be inferred to have evolved once. Holoparasitism has evolved independently at least five times, with certain holoparasitic lineages representing single species, genera, and collections of nonphotosynthetic genera. Evolutionary loss of the photosynthetic gene rbcL is limited to a subset of holoparasitic lineages, with several holoparasites retaining a full length rbcL sequence. In contrast, the translational gene rps2 is retained in all plants investigated but has experienced rate accelerations in several hemi- as well as holoparasitic lineages, suggesting that there may be substantial molecular evolutionary changes to the plastid genome of parasites before the loss of photosynthesis. Independent patterns of synonymous and nonsynonymous rate acceleration in rps2 point to distinct mechanisms underlying rate variation in different lineages. Parasitic Scrophulariaceae (including the traditional Orobanchaceae) provide a rich platform for the investigation of molecular evolutionary process, gene function, and the evolution of parasitism. PMID:9207097

  17. Resource limitation and the role of a hemiparasite on a restored prairie.

    PubMed

    Borowicz, Victoria A; Armstrong, Joseph E

    2012-07-01

    Hemiparasitic plants tend to thrive in and significantly affect plant communities in low-nutrient, high-light environments. Hemiparasites are assumed to be weak competitors for light but strong parasites, leading to the prediction that effects on hosts and communities should be a function of resource supply. We investigated the effects of light and mineral nutrients on hemiparasite-host relations in two experiments. Removal of the hemiparasite, addition of fertilizer, and full sun significantly increased total aboveground dry mass in small plots on a restored tallgrass prairie. After 3 years, removal of Pedicularis canadensis almost doubled the mass of grasses and had smaller effects on forb species, but the impact of the parasite was independent of resource level. Fertilizer increased grass growth only in full sun, increased non-legume forb growth only when shade was applied, and tended to depress legume growth when shaded. Light manipulation did not affect the hemiparasite across 4 years of manipulation but fertilizer increased P. canadensis shoot mass. A complementary greenhouse experiment with Andropogon gerardii as host produced qualitatively similar effects and showed that shade reduced root growth of both the host and the parasite. These results do not support common assumptions regarding hemiparasite-host relations under field conditions but indicate that a small hemiparasite can significantly affect prairie productivity regardless of resource supply.

  18. Integrating ecology and physiology of root-hemiparasitic interaction: interactive effects of abiotic resources shape the interplay between parasitism and autotrophy.

    PubMed

    Těšitel, Jakub; Těšitelová, Tamara; Fisher, James P; Lepš, Jan; Cameron, Duncan D

    2015-01-01

    Root hemiparasites are green photosynthetic plants, which parasitically acquire resources from host xylem. Mineral nutrients and water, two principal below-ground abiotic resources, were assumed to affect the interaction between hemiparasites and their hosts. The shape of these effects and the underlying physiological mechanisms have, however, remained unclear. We conducted a glasshouse experiment with root-hemiparasitic Rhinanthus alectorolophus, in which we manipulated the availability of mineral nutrients and water. Biomass production and Chl fluorescence of the hemiparasites and hosts were recorded, together with proportion of host-derived carbon in hemiparasite biomass. The abiotic resources had profound interactive effects on the performance of both the hemiparasite and the hosts, as well as the balance of above-ground biomass between them. These effects were mainly based on an increase of growth and photosynthetic efficiency under high nutrient concentrations, on the hemiparasite's ability to induce strong water stress on the hosts if water is limiting, and on release of the host from parasitism by simultaneous abundance of both resources. Hemiparasitism is a highly variable interaction, in which environmental conditions affect both the parasitic and autotrophic (and thus competitive) components. A hemiparasite's own photosynthesis plays a crucial role in the assimilation of parasitized mineral resources and their transformation into growth and fitness.

  19. Ultrastructure of hydathode trichomes of hemiparasitic Rhinanthus alectorolophus and Odontites vernus: how important is their role in physiology and evolution of parasitism in Orobanchaceae?

    PubMed

    Těšitel, J; Tesařová, M

    2013-01-01

    The Rhinanthoid clade of the family Orobanchaceae comprises plants displaying a hemiparasitic or holoparasitic strategy of resource acquisition. Some of its species (mainly Rhinanthus spp.) are often used as models for studies of hemiparasite physiology. Although there is a well-developed concept covering their physiological processes, most recent studies have neglected the existence of hydathode trichomes present on leaves of these hemiparasitic plants. As a first step for the proposed integration of these structures in the theory of physiological processes of the hemiparasites, we described the outer micromorphology and ultrastructure of the hydathode trichomes on leaves of hemiparasitic Rhinanthus alectorolophus and Odontites vernus with scanning and transmission electron microscopy (SEM and TEM, respectively). The TEM inspections of both types of trichome revealed typical ultrastructural features: labyrinthine cell wall, high content of cytoplasm in cells with numerous mitochondria and presence of plasmodesmata. All these features indicate high metabolic activity complying with their function as glandular trichomes actively secreting water. The active secretion of water by the hydathode trichomes (evidence for which is summarised here) also presents a possible mechanism explaining results of previous gas exchange measurements detecting high dark respiration and transpiration rates and a tight inter-correlation between them in hemiparasitic Orobanchaceae. In addition, this process is hypothesised to have allowed multiple evolutionary transitions from facultative to obligate hemiparasitism and unique xylem-feeding holoparasitism of Lathraea with a long-lived underground stage featuring a rhizome covered by scales of leaf origin.

  20. Heterotrophic carbon gain by the root hemiparasites, Rhinanthus minor and Euphrasia rostkoviana (Orobanchaceae).

    PubMed

    Tesitel, Jakub; Plavcová, Lenka; Cameron, Duncan D

    2010-04-01

    Hemiparasitic plants gain virtually all mineral nutrients and water from their host plant whilst organic carbon is provided, at least in part, by their own photosynthetic activity, although their rates of assimilation are substantially lower than that found in non-parasitic plants. Hence, hemiparasites must gain at least some of their organic carbon heterotrophically from the host plant. Despite this, heterotrophic carbon gain by root hemiparasites has been investigated only for a few genera. We investigated heterotrophic carbon gain by two root hemiparasites, Rhinanthus minor L. and Euphrasia rostkoviana Hayne (Orobanchaceae), using natural abundance stable isotope (delta(13)C) profiles of both parasites attached to C(3) (wheat) and C(4) (maize) hosts coupled to a linear two-source isotope-mixing model to estimate the percentage of carbon in the parasite that was derived from the host. Both R. minor and E. rostkoviana attached to maize hosts were significantly more enriched in (13)C than those attached to wheat hosts with R. minor becoming more enriched in (13)C than E. rostkoviana. The natural abundance (13)C profiles of both parasites were not significantly different from their wheat hosts, but were less enriched in (13)C than maize hosts. Using a linear two-source isotope-mixing model, we estimated that R. minor and E. rostkoviana adult plants derive c. 50 and 25% of their carbon from their hosts, respectively. In light of these results, we hypothesise that repeatedly observed negative effect of competition for light on hemiparasites acts predominantly in early ontogenetic stages when parasites grow unattached or the abstraction of host nutrients is less effective.

  1. High mountain origin, phylogenetics, evolution, and niche conservatism of arctic lineages in the hemiparasitic genus Pedicularis (Orobanchaceae).

    PubMed

    Tkach, Natalia; Ree, Richard H; Kuss, Patrick; Röser, Martin; Hoffmann, Matthias H

    2014-07-01

    The origin of the arctic flora covering the northernmost treeless areas is still poorly understood. Arctic plants may have evolved in situ or immigrated from the adjacent ecosystems. Frequently arctic species have disjunctive distributions between the Arctic and high mountain systems of the temperate zone. This pattern may result from long distance dispersal or from glacial plant migrations and extinctions of intermediate populations. The hemiparasitic genus Pedicularis is represented in the Arctic by c. 28 taxa and ranks among the six most species-rich vascular plant genera of this region. In this study, we test the hypothesis that these lineages evolved from predecessors occurring in northern temperate mountain ranges, many of which are current centers of diversity for the genus. We generated a nuclear ribosomal and chloroplast DNA phylogeny including almost all of the arctic taxa and nearly half of the genus as a whole. The arctic taxa of Pedicularis evolved 12-14 times independently and are mostly nested in lineages that otherwise occur in the high mountains of Eurasia and North America. It appears that only three arctic lineages arose from the present-day center of diversity of the genus, in the Hengduan Mountains and Himalayas. Two lineages are probably of lowland origin. Arctic taxa of Pedicularis show considerable niche conservatism with respect to soil moisture and grow predominantly in moist to wet soils. The studied characteristics of ecology, morphology, and chromosome numbers of arctic Pedicularis show a heterogeneous pattern of evolution. The directions of morphological changes among the arctic lineages show opposing trends. Arctic taxa are chiefly diploid, the few tetraploid chromosome numbers of the genus were recorded only for arctic taxa. Five arctic Pedicularis are annuals or biennials, life forms otherwise rare in the Arctic. Other genera of the Orobanchaceae consist also of an elevated number of short-lived species, thus hemiparasitism may

  2. Plastome Evolution in Hemiparasitic Mistletoes

    PubMed Central

    Petersen, Gitte; Cuenca, Argelia; Seberg, Ole

    2015-01-01

    Santalales is an order of plants consisting almost entirely of parasites. Some, such as Osyris, are facultative root parasites whereas others, such as Viscum, are obligate stem parasitic mistletoes. Here, we report the complete plastome sequences of one species of Osyris and three species of Viscum, and we investigate the evolutionary aspects of structural changes and changes in gene content in relation to parasitism. Compared with typical angiosperms plastomes, the four Santalales plastomes are all reduced in size (10–22% compared with Vitis), and they have experienced rearrangements, mostly but not exclusively in the border areas of the inverted repeats. Additionally, a number of protein-coding genes (matK, infA, ccsA, rpl33, and all 11 ndh genes) as well as two transfer RNA genes (trnG-UCC and trnV-UAC) have been pseudogenized or completely lost. Most of the remaining plastid genes have a significantly changed selection pattern compared with other dicots, and the relaxed selection of photosynthesis genes is noteworthy. Although gene loss obviously reduces plastome size, intergenic regions were also shortened. As plastome modifications are generally most prominent in Viscum, they are most likely correlated with the increased nutritional dependence on the host compared with Osyris. PMID:26319577

  3. Response of a root hemiparasite to elevated CO2 depends on host type and soil nutrients.

    PubMed

    Matthies, Diethart; Egli, Philipp

    1999-07-01

    Although elevated CO2 may affect various forms of ecological interactions, the effect of elevated CO2 on interactions between parasitic plants and their hosts has received little attention. We examined the effect of elevated CO2 (590 μl l(-1)) at two nutrient (NPK) levels on the interactions of the facultative root hemiparasite Rhinanthus alectorolophus with two of its hosts, the grass Lolium perenne and the legume Medicago sativa. To study possible effects on parasite mediation of competition between hosts, the parasite was grown with each host separately and with both hosts simultaneously. In addition, all combinations of hosts were grown without the parasite. Both the parasite and the host plants responded to elevated CO2 with increased growth, but only at high nutrient levels. The CO2 response of the hemiparasite was stronger than that of the hosts, but depended on the host species available. With L. perenne and M. sativa simultaneously available as hosts, the biomass of the parasite grown at elevated CO2 was 5.7 times that of parasites grown at ambient CO2. Nitrogen concentration in the parasites was not influenced by the treatments and was not related to parasite biomass. The presence of the parasite strongly reduced both the biomass of the hosts and total productivity of the system. This effect was much stronger at low than at high nutrient levels, but was not influenced by CO2 level. Elevated CO2 did not influence the competitive balance between the two different hosts grown in mixture. The results of this study support the hypothesis that hemiparasites may influence community structure and suggest that these effects are robust to changes in CO2 concentration.

  4. Does light influence the relationship between a native stem hemiparasite and a native or introduced host?

    PubMed

    Cirocco, Robert Michael; Facelli, José Maria; Watling, Jennifer Robyn

    2016-03-01

    There have been very few studies investigating the influence of light on the effects of hemiparasitic plants on their hosts, despite the fact that hemiparasites are capable of photosynthesis but also access carbon (C) from their host. In this study we manipulated light availability to limit photosynthesis in an established hemiparasite and its hosts, and determined whether this affected the parasite's impact on growth and performance of two different hosts. We expected that limiting light and reducing autotrophic C gain in the parasite (and possibly increasing its heterotrophic C gain) would lead to an increased impact on host growth and/or host photosynthesis in plants grown in low (LL) relative to high light (HL). The Australian native host Leptospermum myrsinoides and the introduced host Ulex europaeus were either infected or not infected with the native stem hemiparasite Cassytha pubescens and grown in either HL or LL. Photosynthetic performance, nitrogen status and growth of hosts and parasite were quantified. Host water potentials were also measured. In situ midday electron transport rates (ETRs) of C. pubescens on both hosts were significantly lower in LL compared with HL, enabling us to investigate the impact of the reduced level of parasite autotrophy on growth of hosts. Despite the lower levels of photosynthesis in the parasite, the relative impact of infection on host biomass was the same in both LL and HL. In fact, biomass of L. myrsinoides was unaffected by infection in either HL or LL, while biomass of U. europaeus was negatively affected by infection in both treatments. This suggests that although photosynthesis of the parasite was lower in LL, there was no additional impact on host biomass in LL. In addition, light did not affect the amount of parasite biomass supported per unit host biomass in either host, although this parameter was slightly lower in LL than HL for U. europaeus (P = 0·073). We also found no significant enhancement of host

  5. Does light influence the relationship between a native stem hemiparasite and a native or introduced host?

    PubMed Central

    Cirocco, Robert Michael; Facelli, José Maria; Watling, Jennifer Robyn

    2016-01-01

    Background and Aims There have been very few studies investigating the influence of light on the effects of hemiparasitic plants on their hosts, despite the fact that hemiparasites are capable of photosynthesis but also access carbon (C) from their host. In this study we manipulated light availability to limit photosynthesis in an established hemiparasite and its hosts, and determined whether this affected the parasite’s impact on growth and performance of two different hosts. We expected that limiting light and reducing autotrophic C gain in the parasite (and possibly increasing its heterotrophic C gain) would lead to an increased impact on host growth and/or host photosynthesis in plants grown in low (LL) relative to high light (HL). Methods The Australian native host Leptospermum myrsinoides and the introduced host Ulex europaeus were either infected or not infected with the native stem hemiparasite Cassytha pubescens and grown in either HL or LL. Photosynthetic performance, nitrogen status and growth of hosts and parasite were quantified. Host water potentials were also measured. Key Results In situ midday electron transport rates (ETRs) of C. pubescens on both hosts were significantly lower in LL compared with HL, enabling us to investigate the impact of the reduced level of parasite autotrophy on growth of hosts. Despite the lower levels of photosynthesis in the parasite, the relative impact of infection on host biomass was the same in both LL and HL. In fact, biomass of L. myrsinoides was unaffected by infection in either HL or LL, while biomass of U. europaeus was negatively affected by infection in both treatments. This suggests that although photosynthesis of the parasite was lower in LL, there was no additional impact on host biomass in LL. In addition, light did not affect the amount of parasite biomass supported per unit host biomass in either host, although this parameter was slightly lower in LL than HL for U. europaeus (P = 0·073). We also

  6. Contrasting effects of hemiparasites on ecosystem processes: can positive litter effects offset the negative effects of parasitism?

    PubMed Central

    Suding, Katharine N.

    2010-01-01

    Hemiparasites are known to influence community structure and ecosystem functioning, but the underlying mechanisms are not well studied. Variation in the impacts of hemiparasites on diversity and production could be due to the difference in the relative strength of two interacting pathways: direct negative effects of parasitism and positive effects on N availability via litter. Strong effects of parasitism should result in substantial changes in diversity and declines in productivity. Conversely, strong litter effects should result in minor changes in diversity and increased productivity. We conducted field-based surveys to determine the association of Castillejaoccidentalis with diversity and productivity in the alpine tundra. To examine litter effects, we compared the decomposition of Castilleja litter with litter of four other abundant plant species, and examined the decomposition of those four species when mixed with Castilleja. Castilleja was associated with minor changes in diversity but almost a twofold increase in productivity and greater foliar N in co-occurring species. Our decomposition trials suggest litter effects are due to both the rapid N loss of Castilleja litter and the effects of mixing Castilleja litter with co-occurring species. Castilleja produces litter that accelerates decomposition in the alpine tundra, which could accelerate the slow N cycle and boost productivity. We speculate that these positive effects of litter outweigh the effects of parasitism in nutrient-poor systems with long-lived hemiparasites. Determining the relative importance of parasitism and litter effects of this functional group is crucial to understand the strong but variable roles hemiparasites play in affecting community structure and ecosystem processes. PMID:20658151

  7. Rare Plants of the Redwood Forest and Forest Management Effects

    Treesearch

    Teresa Sholars; Clare Golec

    2007-01-01

    Coast redwood forests are predominantly a timber managed habitat type, subjected to repeated disturbances and short rotation periods. What does this repeated disturbance mean for rare plants associated with the redwood forests? Rare plant persistence through forest management activities is influenced by many factors. Persistence of rare plants in a managed landscape is...

  8. [Rare plant species: floristic, phytocoenotic and population approach].

    PubMed

    Zlobin, Iu A

    2011-01-01

    The system of concepts used when estimating the rarity of plants is analyzed and the basic categories of rarity are defined, namely: true, diffuse, peripheral and temporal. The insufficiency of scientific information on ecological and coenotic relationships of rare plants is demonstrated and the necessity of a complex assessment of population system of a rare plant species is substantiated. The importance and limitations of the information on rare plants contained in the Red Books and the Red Lists for phytosozological practice is discussed.

  9. Rainfall effects on rare annual plants

    USGS Publications Warehouse

    Levine, J.M.; McEachern, A.K.; Cowan, C.

    2008-01-01

    Variation in climate is predicted to increase over much of the planet this century. Forecasting species persistence with climate change thus requires understanding of how populations respond to climate variability, and the mechanisms underlying this response. Variable rainfall is well known to drive fluctuations in annual plant populations, yet the degree to which population response is driven by between-year variation in germination cueing, water limitation or competitive suppression is poorly understood.We used demographic monitoring and population models to examine how three seed banking, rare annual plants of the California Channel Islands respond to natural variation in precipitation and their competitive environments. Island plants are particularly threatened by climate change because their current ranges are unlikely to overlap regions that are climatically favourable in the future.Species showed 9 to 100-fold between-year variation in plant density over the 5–12 years of censusing, including a severe drought and a wet El Niño year. During the drought, population sizes were low for all species. However, even in non-drought years, population sizes and per capita growth rates showed considerable temporal variation, variation that was uncorrelated with total rainfall. These population fluctuations were instead correlated with the temperature after the first major storm event of the season, a germination cue for annual plants.Temporal variation in the density of the focal species was uncorrelated with the total vegetative cover in the surrounding community, suggesting that variation in competitive environments does not strongly determine population fluctuations. At the same time, the uncorrelated responses of the focal species and their competitors to environmental variation may favour persistence via the storage effect.Population growth rate analyses suggested differential endangerment of the focal annuals. Elasticity analyses and life table response

  10. RNA-Seq analysis identifies key genes associated with haustorial development in the root hemiparasite Santalum album

    PubMed Central

    Zhang, Xinhua; Berkowitz, Oliver; Teixeira da Silva, Jaime A.; Zhang, Muhan; Ma, Guohua; Whelan, James; Duan, Jun

    2015-01-01

    Santalum album (sandalwood) is one of the economically important plant species in the Santalaceae for its production of highly valued perfume oils. Sandalwood is also a hemiparasitic tree that obtains some of its water and simple nutrients by tapping into other plants through haustoria which are highly specialized organs in parasitic angiosperms. However, an understanding of the molecular mechanisms involved in haustorium development is limited. In this study, RNA sequencing (RNA-seq) analyses were performed to identify changes in gene expression and metabolic pathways associated with the development of the S. album haustorium. A total of 56,011 non-redundant contigs with a mean contig size of 618 bp were obtained by de novo assembly of the transcriptome of haustoria and non-haustorial seedling roots. A substantial number of the identified differentially expressed genes were involved in cell wall metabolism and protein metabolism, as well as mitochondrial electron transport functions. Phytohormone-mediated regulation might play an important role during haustorial development. Especially, auxin signaling is likely to be essential for haustorial initiation, and genes related to cytokinin and gibberellin biosynthesis and metabolism are involved in haustorial development. Our results suggest that genes encoding nodulin-like proteins may be important for haustorial morphogenesis in S. album. The obtained sequence data will become a rich resource for future research in this interesting species. This information improves our understanding of haustorium development in root hemiparasitic species and will allow further exploration of the detailed molecular mechanisms underlying plant parasitism. PMID:26388878

  11. Transfer of selected mineral nutrients and trace elements in the host-hemiparasite association, Cistus-Odontites lutea, growing on and off metal-polluted sites.

    PubMed

    Llugany, M; Lombini, A; Dinelli, E; Poschenrieder, C; Barceló, J

    2009-03-01

    The role of a hemiparasitic life-style in plant resistance to toxic trace elements in polluted soils is unclear. Restriction of metal uptake by the host, restriction of metal transfer from host to parasite, or transformation of metals into a less toxic form may play a role. This study analysed the transfer of selected mineral elements from soil to host (Cistus spp.) and from host to hemiparasite (Odontites lutea) at locations with different metal burdens: a Cu-rich serpentine site, Pb-Ba mine spoil and an unpolluted soil. Highest soil-to-host transfer factors for K, Mg, Ca, Zn, Cu and Pb were observed on the unpolluted soil. Statistically significant differences among locations of host-to-parasite transfer factors were only found for Ca and Pb. Restriction of transfer of unfavourable Ca/Mg ratios, characteristic at the serpentine site, and of high Pb and Zn concentrations at the Pb-Ba mine occurred mainly at the soil-host, and not at the host-parasite, level. Odontites lutea was able to withstand enhanced Zn and Pb concentrations and low Fe/Cu ratios in shoot tissue without developing toxicity symptoms. This could be caused by specific metal resistance mechanisms in this hemiparasite and/or the transformation and transfer of these metals into a less toxic form by the metal-tolerant host.

  12. Ecological and population genetics of locally rare plants: A review

    Treesearch

    Simon A. Lei

    2001-01-01

    Plant species with limited dispersal ability, narrow geographical and physiological tolerance ranges, as well as with specific habitat and ecological requirements are likely to be rare. Small and isolated populations and species contain low levels of within-population genetic variation in many plant species. The gene pool of plants is a product of phenotype-environment...

  13. Two-way transfer of nitrogen between Dalbergia odorifera and its hemiparasite Santalum album is enhanced when the host is effectively nodulated and fixing nitrogen.

    PubMed

    Lu, J K; Kang, L H; Sprent, J I; Xu, D P; He, X H

    2013-05-01

    Nutrient translocation from a host plant is vital to the growth and survival of its root parasitic plant, but few studies have investigated whether a parasitic plant is also able to transfer nutrients to its host. The role of N2-fixation in nitrogen (N) transfer between 7-month-old Dalbergia odorifera T. Chen nodulated with Bradyrhizobium elkanii DG and its hemiparasite Santalum album Linn. was examined by external (15)N labeling in a pot study. Four paired treatments were used, with (15)N given to either host or hemiparasite and the host either nodulated or grown on combined N. N2-fixation supplied 41-44% of total N in D. odorifera. Biomass, N and (15)N contents were significantly greater in both nodulated D. odorifera and S. album grown with paired nodulated D. odorifera. Significantly higher total plant (15)N recovery was in N donor D. odorifera (68-72%) than in N donor S. album (42-44%), regardless of the nodulation status in D. odorifera. Nitrogen transfer to S. album was significantly greater (27.8-67.8 mg plant(-1)) than to D. odorifera (2.0-8.9 mg plant(-1)) and 2.4-4.5 times greater in the nodulated pair than in the non-nodulated pair. Irrespective of the nodulation status, S. album was always the N-sink plant. The amount of two-way N transfer was increased by the presence of effective nodules, resulting in a greater net N transfer (22.6 mg plant(-1)) from host D. odorifera to hemiparasite S. album. Our results may provide N management strategies for D. odorifera/S. album mixed plantations in the field.

  14. Interagency Rare Plant Team inventory results - 1998 through 2003

    Treesearch

    Deborah J. Clark; David A. Tait

    2007-01-01

    Fishlake National Forest, Dixie National Forest, Bureau of Land Management - Richfield Field Office, and Capitol Reef National Park became partners in an Interagency Agreement to inventory and monitor threatened, endangered, and sensitive plant species shared by these agencies. From 1998 to 2003, the Interagency Rare Plant Team surveyed and recorded over 650 new...

  15. Rareness and specialization in plant-pollinator networks.

    PubMed

    Dorado, Jimena; Vázquez, Diego P; Stevani, Erica L; Chacoff, Natacha P

    2011-01-01

    Most rare species appear to be specialists in plant-pollinator networks. This observation could result either from real ecological processes or from sampling artifacts. Several methods have been proposed to overcome these artifacts, but they have the limitation of being based on visitation data, causing interactions involving rare visitor species to remain undersampled. We propose the analysis of food composition in bee trap nests to assess the reliability of network specialization estimates. We compared data from a plant-pollinator network in the Monte Desert of Villavicencio Nature Reserve, Argentina, sampled by visit observation, and data from trap nests sampled at the same time and location. Our study shows that trap nest sampling was good for estimating rare species degree. The rare species in the networks appear to be more specialized than they really are, and the bias in the estimation of the species degree increases with the rareness. The low species degree of these rare species in the visitation networks results from insufficient sampling of the rare interactions, which could have important consequences for network structure.

  16. Microsites Matter: Improving the Success of Rare Species Reintroductions

    PubMed Central

    Dunwiddie, Peter W.; Martin, R. Adam

    2016-01-01

    Our study was undertaken to better understand how to increase the success rates of recovery plantings of a rare hemiparasite, golden paintbrush (Castilleja levisecta—Orobanchaceae). This species is endemic to western Washington and Oregon, USA, and southwestern British Columbia, Canada. Over 5000 golden paintbrush plants were outplanted as plugs in 2007 at six different native prairie sites that were considered to be suitable habitat, based on general evaluations of vegetation and soil conditions. Outplantings were installed at regular intervals along transects up to 1 km long to include a range of conditions occurring at each site. All plantings were re-examined five years later. The patchy distribution of surviving plugs and new recruits within each reintroduction site suggested success is strongly influenced by microsite characteristics. Indicator species analysis of taxa growing in microsites around outplanted golden paintbrush identified species that were positively or negatively associated with paintbrush survival. Species such as Festuca roemeri, Eriophyllum lanatum, and Viola adunca were strong indicators at some sites; non-natives such as Hypochaeris radicata and Teesdalia nudicaulis tended to be frequent negative indicators. Overall, higher richness of native perennial forbs was strongly correlated with both survival and flowering of golden paintbrush, a pattern that may reflect interactions of this hemiparasite with the immediately surrounding plant community. Topographic position also influenced outcomes, with greater survival occurring on mounds and in swales, where soils generally were deeper. Our findings suggest that assessments of site suitability based on vegetation alone, and coarser, site-level assessments that do not characterize heterogeneity at the microsite scale, may not be strong predictors of restoration success over the longer term and in sites with variability in vegetation and soils. By identifying suitable microsites to focus rare

  17. Microsites Matter: Improving the Success of Rare Species Reintroductions.

    PubMed

    Dunwiddie, Peter W; Martin, R Adam

    2016-01-01

    Our study was undertaken to better understand how to increase the success rates of recovery plantings of a rare hemiparasite, golden paintbrush (Castilleja levisecta-Orobanchaceae). This species is endemic to western Washington and Oregon, USA, and southwestern British Columbia, Canada. Over 5000 golden paintbrush plants were outplanted as plugs in 2007 at six different native prairie sites that were considered to be suitable habitat, based on general evaluations of vegetation and soil conditions. Outplantings were installed at regular intervals along transects up to 1 km long to include a range of conditions occurring at each site. All plantings were re-examined five years later. The patchy distribution of surviving plugs and new recruits within each reintroduction site suggested success is strongly influenced by microsite characteristics. Indicator species analysis of taxa growing in microsites around outplanted golden paintbrush identified species that were positively or negatively associated with paintbrush survival. Species such as Festuca roemeri, Eriophyllum lanatum, and Viola adunca were strong indicators at some sites; non-natives such as Hypochaeris radicata and Teesdalia nudicaulis tended to be frequent negative indicators. Overall, higher richness of native perennial forbs was strongly correlated with both survival and flowering of golden paintbrush, a pattern that may reflect interactions of this hemiparasite with the immediately surrounding plant community. Topographic position also influenced outcomes, with greater survival occurring on mounds and in swales, where soils generally were deeper. Our findings suggest that assessments of site suitability based on vegetation alone, and coarser, site-level assessments that do not characterize heterogeneity at the microsite scale, may not be strong predictors of restoration success over the longer term and in sites with variability in vegetation and soils. By identifying suitable microsites to focus rare

  18. High water availability increases the negative impact of a native hemiparasite on its non-native host.

    PubMed

    Cirocco, Robert M; Facelli, José M; Watling, Jennifer R

    2016-03-01

    Environmental factors alter the impacts of parasitic plants on their hosts. However, there have been no controlled studies on how water availability modulates stem hemiparasites' effects on hosts. A glasshouse experiment was conducted to investigate the association between the Australian native stem hemiparasite Cassytha pubescens and the introduced host Ulex europaeus under high (HW) and low (LW) water supply. Cassytha pubescens had a significant, negative effect on the total biomass of U. europaeus, which was more severe in HW than LW. Regardless of watering treatment, infection significantly decreased shoot and root biomass, nodule biomass, nodule biomass per unit root biomass, F v/F m, and nitrogen concentration of U. europaeus. Host spine sodium concentration significantly increased in response to infection in LW but not HW conditions. Host water potential was significantly higher in HW than in LW, which may have allowed the parasite to maintain higher stomatal conductances in HW. In support of this, the δ(13)C of the parasite was significantly lower in HW than in LW (and significantly higher than the host). C. pubescens also had significantly higher F v/F m and 66% higher biomass per unit host in the HW compared with the LW treatment. The data suggest that the enhanced performance of C. pubescens in HW resulted in higher parasite growth rates and thus a larger demand for resources from the host, leading to poorer host performance in HW compared with LW. C. pubescens should more negatively affect U. europaeus growth under wet conditions rather than under dry conditions in the field.

  19. Rare earth elements activate endocytosis in plant cells

    PubMed Central

    Wang, Lihong; Li, Jigang; Zhou, Qing; Yang, Guangmei; Ding, Xiao Lan; Li, Xiaodong; Cai, Chen Xin; Zhang, Zhao; Wei, Hai Yan; Lu, Tian Hong; Deng, Xing Wang; Huang, Xiao Hua

    2014-01-01

    It has long been observed that rare earth elements (REEs) regulate multiple facets of plant growth and development. However, the underlying mechanisms remain largely unclear. Here, using electron microscopic autoradiography, we show the life cycle of a light REE (lanthanum) and a heavy REE (terbium) in horseradish leaf cells. Our data indicate that REEs were first anchored on the plasma membrane in the form of nanoscale particles, and then entered the cells by endocytosis. Consistently, REEs activated endocytosis in plant cells, which may be the cellular basis of REE actions in plants. Moreover, we discovered that a portion of REEs was successively released into the cytoplasm, self-assembled to form nanoscale clusters, and finally deposited in horseradish leaf cells. Taken together, our data reveal the life cycle of REEs and their cellular behaviors in plant cells, which shed light on the cellular mechanisms of REE actions in living organisms. PMID:25114214

  20. [Research advance in rare and endemic plant Tetraena mongolica Maxim].

    PubMed

    Zhen, Jiang-Hong; Liu, Guo-Hou

    2008-02-01

    In this paper, the research advance in rare and endemic plant Tetraena mongolica Maxim. was summarized from the aspects of morphology, anatomy, palynology, cytology, seed-coat micro-morphology, embryology, physiology, biology, ecology, genetic diversity, chemical constituents, endangered causes, and conservation approaches, and the further research directions were prospected. It was considered that population viability, idioplasm conservation and artificial renewal, molecular biology of ecological adaptability, and assessment of habitat suitability should be the main aspects for the future study of T. mongolica.

  1. Wildlife-friendly farming benefits rare birds, bees and plants

    PubMed Central

    Pywell, Richard F.; Heard, Matthew S.; Bradbury, Richard B.; Hinsley, Shelley; Nowakowski, Marek; Walker, Kevin J.; Bullock, James M.

    2012-01-01

    Agricultural intensification is a leading cause of global biodiversity loss, especially for threatened and near-threatened species. One widely implemented response is ‘wildlife-friendly farming’, involving the close integration of conservation and extensive farming practices within agricultural landscapes. However, the putative benefits from this controversial policy are currently either unknown or thought unlikely to extend to rare and declining species. Here, we show that new, evidence-based approaches to habitat creation on intensively managed farmland in England can achieve large increases in plant, bee and bird species. In particular, we found that habitat enhancement methods designed to provide the requirements of sensitive target biota consistently increased the richness and abundance of both rare and common species, with 10-fold to greater than 100-fold more rare species per sample area than generalized conventional conservation measures. Furthermore, targeting landscapes of high species richness amplified beneficial effects on the least mobile taxa: plants and bees. Our results provide the first unequivocal support for a national wildlife-friendly farming policy and suggest that this approach should be implemented much more extensively to address global biodiversity loss. However, to be effective, these conservation measures must be evidence-based, and developed using sound knowledge of the ecological requirements of key species. PMID:22675140

  2. Wildlife-friendly farming benefits rare birds, bees and plants.

    PubMed

    Pywell, Richard F; Heard, Matthew S; Bradbury, Richard B; Hinsley, Shelley; Nowakowski, Marek; Walker, Kevin J; Bullock, James M

    2012-10-23

    Agricultural intensification is a leading cause of global biodiversity loss, especially for threatened and near-threatened species. One widely implemented response is 'wildlife-friendly farming', involving the close integration of conservation and extensive farming practices within agricultural landscapes. However, the putative benefits from this controversial policy are currently either unknown or thought unlikely to extend to rare and declining species. Here, we show that new, evidence-based approaches to habitat creation on intensively managed farmland in England can achieve large increases in plant, bee and bird species. In particular, we found that habitat enhancement methods designed to provide the requirements of sensitive target biota consistently increased the richness and abundance of both rare and common species, with 10-fold to greater than 100-fold more rare species per sample area than generalized conventional conservation measures. Furthermore, targeting landscapes of high species richness amplified beneficial effects on the least mobile taxa: plants and bees. Our results provide the first unequivocal support for a national wildlife-friendly farming policy and suggest that this approach should be implemented much more extensively to address global biodiversity loss. However, to be effective, these conservation measures must be evidence-based, and developed using sound knowledge of the ecological requirements of key species.

  3. Population and community ecology of the rare plant amsinckia grandiflora

    SciTech Connect

    Carlsen, T.M.

    1996-11-01

    Research was conducted between the fall of 1992 and the spring on the population and community ecology of the rare annual plant, Amsinckia glandiflora (Gray) Kleeb. ex Greene (Boraginaceae). The research goal was to investigate the causes of the species rarity, data useful to restorative efforts. The work focused on the examination of competitive suppression by exotic annual grasses; comparisons with common, weedy congener; and the role of litter cover and seed germination and seedling establishment. Annual exotic grasses reduced A. grandiflora reproductive output to a greater extent than did the native perennial bunch grass.

  4. Conservation investment for rare plants in urban environments.

    PubMed

    Schwartz, Mark W; Smith, Lacy M; Steel, Zachary L

    2013-01-01

    Budgets for species conservation limit actions. Expending resources in areas of high human density is costly and generally considered less likely to succeed. Yet, coastal California contains both a large fraction of narrowly endemic at-risk plant species as well as the state's three largest metropolitan regions. Hence understanding the capacity to protect species along the highly urbanized coast is a conservation priority. We examine at-risk plant populations along California's coastline from San Diego to north of San Francisco to better understand whether there is a relationship between human population density and: i) performance of at-risk plant populations; and ii) conservation spending. Answering these questions can help focus appropriate strategic conservation investment. Rare plant performance was measured using the annualized growth rate estimate between census periods using the California Natural Diversity Database. Human density was estimated using Census Bureau statistics from the year 2000. We found strong evidence for a lack of a relationship between human population density and plant population performance in California's coastal counties. Analyzing US Endangered Species expenditure reports, we found large differences in expenditures among counties, with plants in San Diego County receiving much higher expenditures than other locations. We found a slight positive relationship between expenditures on behalf of endangered species and human density. Together these data support the argument that conservation efforts by protecting habitats within urban environments are not less likely to be successful than in rural areas. Expenditures on behalf of federally listed endangered and threatened plants do not appear to be related to proximity to human populations. Given the evidence of sufficient performance in urban environments, along with a high potential to leverage public support for nature in urban environments, expenditures in these areas appear to be an

  5. Conservation Investment for Rare Plants in Urban Environments

    PubMed Central

    Schwartz, Mark W.; Smith, Lacy M.; Steel, Zachary L.

    2013-01-01

    Budgets for species conservation limit actions. Expending resources in areas of high human density is costly and generally considered less likely to succeed. Yet, coastal California contains both a large fraction of narrowly endemic at-risk plant species as well as the state's three largest metropolitan regions. Hence understanding the capacity to protect species along the highly urbanized coast is a conservation priority. We examine at-risk plant populations along California's coastline from San Diego to north of San Francisco to better understand whether there is a relationship between human population density and: i) performance of at-risk plant populations; and ii) conservation spending. Answering these questions can help focus appropriate strategic conservation investment. Rare plant performance was measured using the annualized growth rate estimate between census periods using the California Natural Diversity Database. Human density was estimated using Census Bureau statistics from the year 2000. We found strong evidence for a lack of a relationship between human population density and plant population performance in California's coastal counties. Analyzing US Endangered Species expenditure reports, we found large differences in expenditures among counties, with plants in San Diego County receiving much higher expenditures than other locations. We found a slight positive relationship between expenditures on behalf of endangered species and human density. Together these data support the argument that conservation efforts by protecting habitats within urban environments are not less likely to be successful than in rural areas. Expenditures on behalf of federally listed endangered and threatened plants do not appear to be related to proximity to human populations. Given the evidence of sufficient performance in urban environments, along with a high potential to leverage public support for nature in urban environments, expenditures in these areas appear to be an

  6. Revisiting the plant hyperaccumulation criteria to rare plants and earth abundant elements.

    PubMed

    Branquinho, Cristina; Serrano, Helena Cristina; Pinto, Manuel João; Martins-Loução, Maria Amélia

    2007-03-01

    The several established criteria to define a hyperaccumulator plant were applied to a rare and endangered species, Plantago almogravensis, and to the 3rd most abundant element in the earth crust, Al. Using the most common criteria, P. almogravensis undoubtedly is an Al hyperaccumulator plant. If the recent proposed requirements were considered, most of them matching those for a plant to be used in phytoextraction, it can only be considered an unusual accumulator of Al. A discussion is made concerning the several criteria of a hyperaccumulator plant in order to include rare and endemic ones and abundant elements. In ecological terms, the enrichment in Al and Fe observed may account for the differences in the vegetation pattern. Due to the rarity and endangered nature of this plant, the contribution of this work is also relevant for the ecological understanding and the development of conservation options of this endemic species.

  7. Direct and indirect influences of arbuscular mycorrhizal fungi on phosphorus uptake by two root hemiparasitic Pedicularis species: do the fungal partners matter at low colonization levels?

    PubMed Central

    Li, Ai-Rong; Guan, Kai-Yun; Stonor, Rebecca; Smith, Sally E.; Smith, F. Andrew

    2013-01-01

    Background and Aims Because most parasitic plants do not form mycorrhizal associations, the nutritional roles of arbuscular mycorrhizal (AM) fungi in them have hardly been tested. Some facultative root hemiparasitic Pedicularis species form AM associations and hence are ideal for testing both direct and indirect effects of AM fungi on their nutrient acquisition. The aim of this study was to test the influence of AM inoculation on phosphorus (P) uptake by Pedicularis rex and P. tricolor. Methods 32P labelling was used in compartmented pots to assess the contribution of the AM pathway and the influence of AM inoculation on P uptake from a host plant into the root hemiparasites. Laboratory isolates of fungal species (Glomus mosseae and G. intraradices) and the host species (Hordeum vulgare ‘Fleet’) to which the two Pedicularis species showed obvious responses in haustorium formation and growth in previous studies were used. Key Results The AM colonization of both Pedicularis spp. was low (<15 % root length) and only a very small proportion of total plant P (<1 %) was delivered from the soil via the AM fungus. In a separate experiment, inoculation with AM fungi strongly interfered with P acquisition by both Pedicularis species from their host barley, almost certainly because the numbers of haustoria formed by the parasite were significantly reduced in AM plants. Conclusions Roles of AM fungi in nutrient acquisition by root parasitic plants were quantitatively demonstrated for the first time. Evidence was obtained for a novel mechanism of preventing root parasitic plants from overexploiting host resources through AM fungal-induced suppression of the absorptive structures in the parasites. PMID:23946322

  8. Boron toxicity in the rare serpentine plant, Streptanthus morrisonii.

    PubMed

    Sage, R F; Ustin, S L; Manning, S J

    1989-01-01

    The release of boron-laden mist from the cooling towers of some geothermal power stations in northern California potentially threatens nearby populations of the rare serpentine plant, Streptanthus morrisonii F. W. Hoffm. To assess the tolerance of S. morrisonii to high levels of boron, the effect of boron on leaf condition, life history, germination rate, growth rate, allocation and photosynthesis was measured on plants grown in a greenhouse. Relative to other species, S. morrisonii was tolerant of excess boron. On serpentine soil, mild to moderate toxicity symptoms (older leaves exhibiting chlorosis and necrosis, but few leaves killed) were apparent when the boron concentration in applied nutrient solutions was 240-650 microm. Severe toxicity symptoms (significant leaf loss, young leaves with toxicity symptoms) were apparent when the applied solution was over 1000 microm boron. Above 1000 microm boron, S. morrisonii appeared unable to complete its life cycle. On a tissue basis, boron toxicity was first observed when leaf boron content was 40-90 micromol g(-1) dry weight. In leaves with severe boron toxicity (> 35% injury), the boron content was generally above 130 micromol g(-1) dry weight. These levels were an order of magnitude above the tissue boron content of plants in the field. Prior to the onset of pronounced boron toxicity symptoms, growth rate, allocation patterns, and photosynthesis were unaffected by high boron. These results indicate that inhibition of growth and photosynthesis occurred because of a loss of viable tissue due to boron injury, rather than a progressive decline as leaf boron levels increased.

  9. 7 CFR 650.22 - Rare, threatened, and endangered species of plants and animals.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 6 2011-01-01 2011-01-01 false Rare, threatened, and endangered species of plants and... Related Environmental Concerns § 650.22 Rare, threatened, and endangered species of plants and animals. (a... endangered species is the destruction or deterioration of their habitats by human activities such as...

  10. 7 CFR 650.22 - Rare, threatened, and endangered species of plants and animals.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 6 2013-01-01 2013-01-01 false Rare, threatened, and endangered species of plants and... Related Environmental Concerns § 650.22 Rare, threatened, and endangered species of plants and animals. (a... endangered species is the destruction or deterioration of their habitats by human activities such as...

  11. 7 CFR 650.22 - Rare, threatened, and endangered species of plants and animals.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 6 2010-01-01 2010-01-01 false Rare, threatened, and endangered species of plants and... Related Environmental Concerns § 650.22 Rare, threatened, and endangered species of plants and animals. (a... endangered species is the destruction or deterioration of their habitats by human activities such as...

  12. 7 CFR 650.22 - Rare, threatened, and endangered species of plants and animals.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 6 2012-01-01 2012-01-01 false Rare, threatened, and endangered species of plants and... Related Environmental Concerns § 650.22 Rare, threatened, and endangered species of plants and animals. (a... endangered species is the destruction or deterioration of their habitats by human activities such as...

  13. 7 CFR 650.22 - Rare, threatened, and endangered species of plants and animals.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 6 2014-01-01 2014-01-01 false Rare, threatened, and endangered species of plants and... Related Environmental Concerns § 650.22 Rare, threatened, and endangered species of plants and animals. (a... endangered species is the destruction or deterioration of their habitats by human activities such as...

  14. Do competitors modulate rare plant response to precipitation change?

    USGS Publications Warehouse

    Levine, J.M.; Kathryn, Mceachern A.; Cowan, C.

    2010-01-01

    Ecologists increasingly suspect that climate change will directly impact species physiology, demography, and phenology, but also indirectly affect these measures via changes to the surrounding community. Unfortunately, few studies examine both the direct and indirect pathways of impact. Doing so is important because altered competitive pressures can reduce or magnify the direct responses of a focal species to climate change. Here, we examine the effects of changing rainfall on three rare annual plant species in the presence and absence of competition on the California Channel Islands. We used rain-out shelters and hand watering to exclude and augment early, late, and season-long rainfall, spanning the wide range of precipitation change forecast for the region. In the absence of competition, droughts reduced the population growth rates of two of three focal annuals, while increased rainfall was only sometimes beneficial, As compared to the focal species, the dominant competitors were more sensitive to the precipitation treatments, benefiting from increased season-long precipitation and harmed by droughts. Importantly, the response of two of three competitors to the precipitation treatments tended to be positively correlated with those of the focal annuals. Although this leads to the expectation that increased competition will counter the direct benefits of favorable conditions, such indirect effects of precipitation change proved weak to nonexistent in our experiment. Competitors had little influence on the precipitation response of two focal species, due to their low sensitivity to competition and highly variable precipitation responses. Competition did affect how our third focal species responded to precipitation change, but this effect only approached significance, and whether it truly resulted from competitor response to precipitation change was unclear. Our work suggests that even when competitors respond to climate change, these responses may have little

  15. Rare and endangered species of Hawai`i Volcanoes National Park; endangered, threatened, and rare animal, plant, and community handbook

    USGS Publications Warehouse

    Pratt, Linda W.; Pratt, Thane K.; Foote, David; Marcos Gorresen, mgorresen@usgs.gov

    2011-01-01

    In some cases, HAVO offers the best opportunity to save these species and communities from extinction. Increasingly, the park has attempted to restore rare populations by conducting surveys to locate them, controlling threats such as feral livestock, and bolstering existing populations or creating new ones by planting nursery stock. To aid such efforts, our original intent was to publish an identification guide for researchers and field management personnel. Particularly, we wanted to familiarize the reader with the many rare plant species which otherwise are known mainly from the technical literature. Because we soon came to realize that this handbook would be useful to a much larger, general readership, our aim is to make this information available to anyone interested in endangered animals and plants at Hawai`i Volcanoes National Park.

  16. Ontogenetic shifts in plant-plant interactions in a rare cycad within angiosperm communities.

    PubMed

    Álvarez-Yépiz, Juan C; Búrquez, Alberto; Dovčiak, Martin

    2014-06-01

    Gymnosperms and angiosperms can co-occur within the same habitats but key plant traits are thought to give angiosperms an evolutionary competitive advantage in many ecological settings. We studied ontogenetic changes in competitive and facilitative interactions between a rare gymnosperm (Dioon sonorense, our target species) and different plant and abiotic neighbours (conspecific-cycads, heterospecific-angiosperms, or abiotic-rocks) from 2007 to 2010 in an arid environment of northwestern Mexico. We monitored survival and growth of seedlings, juveniles, and adults of the cycad Dioon sonorense to evaluate how cycad survival and relative height growth rate (RHGR) responded to intra- and interspecific competition, canopy openness, and nearest neighbour. We tested spatial associations among D. sonorense life stages and angiosperm species and measured ontogenetic shifts in cycad shade tolerance. Canopy openness decreased cycad survival while intraspecific competition decreased survival and RHGR during early ontogeny. Seedling survival was higher in association with rocks and heterospecific neighbours where intraspecific competition was lower. Shade tolerance decreased with cycad ontogeny reflecting the spatial association of advanced stages with more open canopies. Interspecific facilitation during early ontogeny of our target species may promote its persistence in spite of increasing interspecific competition in later stages. We provide empirical support to the long-standing assumption that marginal rocky habitats serve as refugia from angiosperm competition for slow-growing gymnosperms such as cycads. The lack of knowledge of plant-plant interactions in rare or endangered species may hinder developing efficient conservation strategies (e.g. managing for sustained canopy cover), especially under the ongoing land use and climatic changes.

  17. Long-term shifts in the phenology of rare and endemic Rocky Mountain plants

    USGS Publications Warehouse

    Munson, Seth M.; Sher, Anna A

    2015-01-01

    CONCLUSIONS: These results provide evidence for large shifts in the phenology of rare Rocky Mountain plants related to climate, which can have strong effects on plant fitness, the abundance of associated wildlife, and the future of plant conservation in mountainous regions.                   

  18. High water availability increases the negative impact of a native hemiparasite on its non-native host

    PubMed Central

    Cirocco, Robert M.; Facelli, José M.; Watling, Jennifer R.

    2016-01-01

    Environmental factors alter the impacts of parasitic plants on their hosts. However, there have been no controlled studies on how water availability modulates stem hemiparasites’ effects on hosts. A glasshouse experiment was conducted to investigate the association between the Australian native stem hemiparasite Cassytha pubescens and the introduced host Ulex europaeus under high (HW) and low (LW) water supply. Cassytha pubescens had a significant, negative effect on the total biomass of U. europaeus, which was more severe in HW than LW. Regardless of watering treatment, infection significantly decreased shoot and root biomass, nodule biomass, nodule biomass per unit root biomass, F v/F m, and nitrogen concentration of U. europaeus. Host spine sodium concentration significantly increased in response to infection in LW but not HW conditions. Host water potential was significantly higher in HW than in LW, which may have allowed the parasite to maintain higher stomatal conductances in HW. In support of this, the δ13C of the parasite was significantly lower in HW than in LW (and significantly higher than the host). C. pubescens also had significantly higher F v/F m and 66% higher biomass per unit host in the HW compared with the LW treatment. The data suggest that the enhanced performance of C. pubescens in HW resulted in higher parasite growth rates and thus a larger demand for resources from the host, leading to poorer host performance in HW compared with LW. C. pubescens should more negatively affect U. europaeus growth under wet conditions rather than under dry conditions in the field. PMID:26703920

  19. Rare earths: atmospheric signatures for oil-fired power plants and refineries.

    PubMed

    Olmez, I; Gordon, G E

    1985-09-06

    The concentration pattern of rare earth elements on fine airborne particles (less than 2.5 micrometers in diameter) is distorted from the crustal abundance pattern in areas influenced by emissions from oil-fired plants and refineries. For example, the ratio of lanthanum to samarium is often greater than 20 compared to a crustal ratio less than 6. The unusual pattern apparently results from the distribution of rare earths in zeolite catalysts used in refining oil. Oil industry emissions perturb the rare earth pattern even at remote locations such as the Mauna Loa Observatory in Hawaii. Rare earth ratios are probably better for long-range tracing of oil emissions than vanadium and nickel concentrations because the ratios of rare earths on fine particles are probably not influenced by deposition and other fractionating processes. Emissions from oil-fired plants can be differentiated from those of refineries on an urban scale by the much smaller amounts of vanadium in the latter.

  20. Long-term shifts in the phenology of rare and endemic Rocky Mountain plants.

    PubMed

    Munson, Seth M; Sher, Anna A

    2015-08-01

    • Mountainous regions support high plant productivity, diversity, and endemism, yet are highly vulnerable to climate change. Historical records and model predictions show increasing temperatures across high elevation regions including the Southern Rocky Mountains, which can have a strong influence on the performance and distribution of montane plant species. Rare plant species can be particularly vulnerable to climate change because of their limited abundance and distribution.• We tracked the phenology of rare and endemic species, which are identified as imperiled, across three different habitat types with herbarium records to determine if flowering time has changed over the last century, and if phenological change was related to shifts in climate.• We found that the flowering date of rare species has accelerated 3.1 d every decade (42 d total) since the late 1800s, with plants in sagebrush interbasins showing the strongest accelerations in phenology. High winter temperatures were associated with the acceleration of phenology in low elevation sagebrush and barren river habitats, whereas high spring temperatures explained accelerated phenology in the high elevation alpine habitat. In contrast, high spring temperatures delayed the phenology of plant species in the two low-elevation habitats and precipitation had mixed effects depending on the season.• These results provide evidence for large shifts in the phenology of rare Rocky Mountain plants related to climate, which can have strong effects on plant fitness, the abundance of associated wildlife, and the future of plant conservation in mountainous regions. © 2015 Botanical Society of America, Inc.

  1. Research of the entry of rare earth elements Eu3+ and La3+ into plant cell.

    PubMed

    Gao, Yongsheng; Zeng, Fuli; Yi, An; Ping, Shi; Jing, Lanhua

    2003-03-01

    Whether rare earth elements can enter into plant cells remains controversial. This article discusses the ultracellular structural localization of lanthanum (La(3+)) and europium (Eu(3+)) in the intact plant cells fed by rare earth elements Eu(3+) and La(3+). Eu-TTA fluorescence analysis of the plasmalemma, cytoplast, and mitochondria showed that Eu(3+) fluorescence intensities in such structures significantly increased. Eu(3+) can directly enter or be carried by the artificial ion carrier A23187 into plant cells through the calcium ion (Ca(2+)) channel and then partially resume the synthesis of amaranthin in the Amaranthus caudatus growing in the dark. Locations of rare earth elements La(3+) and Eu(3+) in all kinds of components of cytoplasmatic organelles were determined with transmission electron microscope, scanning electron microscope, and energy-dispersive X-ray microanalysis. The results of energy-dispersive X-ray microanalysis indicated that Eu(3+) and La(3+) can be absorbed into plant cells and bind to the membranes of protoplasm, chloroplast, mitochondrion, cytoplast, and karyon. These results provide experimental evidence that rare earth elements can be absorbed into plant cells, which would be the basis for interpreting physiological and biochemical effects of rare earth elements on plant cells.

  2. Advances in the reintroduction of rare and endangered wild plant species.

    PubMed

    Ren, Hai; Jian, ShuGuang; Liu, HongXiao; Zhang, QianMei; Lu, HongFang

    2014-06-01

    Human disturbance and climate change have increased the risk of extinction for rare and endangered wild plant species. One effective way to conserve these rare and endangered species is through reintroduction. In this review, we summarize the advances in wild plant reintroduction from five perspectives: the establishment of reintroduction biology as an important tool for biodiversity conservation; the importance of genetic diversity in reintroduction; reintroduction under global climate change; recruitment limitation in reintroduction; and reintroduction and ecological restoration. In addition, we consider the future of plant reintroduction strategies.

  3. Rare and endangered species of plants--the soviet side.

    PubMed

    Elias, T S

    1983-01-07

    In late 1972, the Soviet Union embarked on a program to identify and document plant species that are threatened with extinction. Perhaps 2000 species in the Soviet Union are in need of monitoring or protective measures, while nearly 200 may be in immediate danger of extinction. Currently, the Soviet Union has an official, national list of endangered species, and each of the 15 republics has prepared a regional list. Once a revised national list is prepared, Soviet scientists hope that the Supreme Soviet will pass a law protecting those species. A corresponding law for endangered animals was passed in 1980.

  4. A comparison of the herbicide tolerances of rare and common plants in an agricultural landscape.

    PubMed

    Egan, J Franklin; Graham, Ian M; Mortensen, David A

    2014-03-01

    Declining plant biodiversity in agroecosystems has often been attributed to escalating use of chemical herbicides, but other changes in farming systems, including the clearing of seminatural habitat fragments, confound the influence of herbicides. The present study introduces a new approach to evaluate the impacts of herbicide pollution on plant communities at landscape or regional scales. If herbicides are in fact a key factor shaping agricultural plant diversity, one would expect to see the signal of past herbicide impacts in the current plant community composition of an intensively farmed region, with common, successful species more tolerant to widely used herbicides than rare or declining species. Data from an extensive field survey of plant diversity in Lancaster County, Pennsylvania, USA, were compared with herbicide bioassay experiments in a greenhouse to test the hypothesis that common species possess higher herbicide tolerances than rare species. Five congeneric pairs of rare and common species were treated with 3 commonly used herbicide modes of action in bioassay experiments, and few significant differences were found in the tolerances of rare species relative to common species. These preliminary results suggest that other factors beyond herbicide exposure may be more important in shaping the distribution and abundance of plant species diversity across an agricultural landscape. © 2014 SETAC.

  5. Intraspecific chromosome number variation: a neglected threat to the conservation of rare plants.

    PubMed

    Severns, Paul M; Liston, Aaron

    2008-12-01

    The effectiveness of rare plant conservation will increase when life history, demographic, and genetic data are considered simultaneously. Inbreeding depression is a widely recognized genetic concern in rare plant conservation, and the mixing of genetically diverse populations in restoration efforts is a common remedy. Nevertheless, if populations with unrecognized intraspecific chromosome variation are crossed, progeny fitness losses will range from partial to complete sterility, and reintroductions and population augmentation of rare plants may fail. To assess the current state of cytological knowledge of threatened and endangered plants in the continental United States, we searched available resources for chromosome counts. We also reviewed recovery plans to discern whether recovery criteria potentially place listed species at risk by requiring reintroductions or population augmentation in the absence of cytological information. Over half the plants lacked a chromosome count, and when a taxon did have a count it generally originated from a sampling intensity too limited to detect intraspecific chromosome variation. Despite limited past cytological sampling, we found 11 plants with documented intraspecific cytological variation, while 8 others were ambiguous for intraspecific chromosome variation. Nevertheless, only one recovery plan addressed the chromosome differences. Inadequate within-species cytological characterization, incomplete sampling among listed taxa, and the prevalence of interspecific and intraspecific chromosome variation in listed genera, suggests that other rare plants are likely to have intraspecific chromosome variation. Nearly 90% of all recovery plans called for reintroductions or population augmentation as part of recovery criteria despite the dearth of cytological knowledge. We recommend screening rare plants for intraspecific chromosome variation before reintroductions or population augmentation projects are undertaken to safeguard

  6. Hanford Site Rare Plant Monitoring Report for Calendar Year 2012

    SciTech Connect

    Salstrom, D; Easterly, R; Lindsey, Cole T.; Nugent, John J.

    2013-03-21

    Two patches of Columbian yellowcress on the Hanford Reach were visited in both 2011 and 2012 to compare ramet counts between years: near Allerd Pumphouse (Rkm 615.4) and near White Bluffs Boat Launch (Rkm 593.3) (Figure 3). In 2012, the population near Allerd Pumphouse had 45 ramets present within a 5x3 m area. At the same population in 2011, there were 60 ramets. In 2012, the population near White Bluffs Boat Launch had 105 ramets in a 2x2 m area. At the same population in 2011, there were 100 ramets. This data shows that while annual variability does exist, ramet counts were relatively similar from 2011 to 2012. This is likely due to the similar flow regimes of 2011 and 2012, which both had above average snowpack, high flows, and extended spring flooding seasons. A total of 19.6 miles (31.5 km) of the Hanford shoreline were surveyed in 2012, with ten patches identified and approximately 1,250 ramets counted. It is not known how many individual plants this count represents due to the rhizomatous nature of the species. Two of these sites were identified previously in the WNHP database, and the remaining eight were newly identified locations. Eleven of the ramets had flowers and/or buds in the patches located during 2012, but no fruits were found

  7. [The application of DNA molecular markers in conservation of the rare and endangered medicinal plants].

    PubMed

    Yan, Zhi-Feng; Zhang, Ben-Gang; Zhang, Zhao; Xia, Tian-Rui

    2005-12-01

    In this paper, the advance in DNA molecular markers techniques in recent years was reviewed. The application of DNA markers in conservation of the rare and endangered medicinal plants was explicated, of which included identification of germ-plasm resource, determination of the habitats unite which should be protected in situ, sampling strategies of ex-situ conservation, evaluation of the conservation effects of the rare and endangered medicinal plants, as well as elucidation of their endangered mechanism etc. The information could help drawing up conservation strategies and conservation measures for references.

  8. Soil microbial communities influence seedling growth of a rare conifer independent of plant-soil feedback.

    PubMed

    Rigg, Jessica L; Offord, Cathy A; Singh, Brajesh K; Anderson, Ian; Clarke, Steve; Powell, Jeff R

    2016-12-01

    Plant-soil feedback, the reciprocal relationship between a plant and its associated microbial communities, has been proposed to be an important driver of plant populations and community dynamics. While rarely considered, understanding how plant-soil feedback contributes to plant rarity may have implications for conservation and management of rare species. Wollemi pine (Wollemia nobilis) is a critically endangered species, of which fewer than 100 trees are known to exist in the wild. Seedling survival within the first year after germination and subsequent recruitment of Wollemi pine is limited in the wild. We used a plant-soil feedback approach to investigate the functional effect of species-specific differences previously observed in the microbial communities underneath adult Wollemi pine and a neighboring species, coachwood (Ceratopetalum apetalum), and also whether additional variation in microbial communities in the wild could impact seedling growth. There was no evidence for seedling growth being affected by tree species associated with soil inocula, suggesting that plant-soil feedbacks are not limiting recruitment in the natural population. However, there was evidence of fungal, but not bacterial, community variation impacting seedling growth independently of plant-soil feedbacks. Chemical (pH) and physical (porosity) soil characteristics were identified as potential drivers of the functional outcomes of these fungal communities. The empirical approach described here may provide opportunities to identify the importance of soil microbes to conservation efforts targeting other rare plant species and is also relevant to understanding the importance of soil microbes and plant-soil feedbacks for plant community dynamics more broadly. © 2016 by the Ecological Society of America.

  9. Biotechnological approaches for conservation and improvement of rare and endangered plants of Saudi Arabia

    PubMed Central

    Khan, Salim; Al-Qurainy, Fahad; Nadeem, Mohammad

    2011-01-01

    Genetic variation is believed to be a prerequisite for the short-and long-term survival of the plant species in their natural habitat. It depends on many environmental factors which determine the number of alleles on various loci in the genome. Therefore, it is important to understand the genetic composition and structure of the rare and endangered plant species from their natural habitat to develop successful management strategies for their conservation. However, rare and endangered plant species have low genetic diversity due to which their survival rate is decreasing in the wilds. The evaluation of genetic diversity of such species is very important for their conservation and gene manipulation. However, plant species can be conserved by in situ and in vitro methods and each has advantages and disadvantages. DNA banking can be considered as a means of complimentary method for the conservation of plant species by preserving their genomic DNA at low temperatures. Such approach of preservation of biological information provides opportunity for researchers to search novel genes and its products. Therefore, in this review we are describing some potential biotechnological approaches for the conservation and further manipulation of these rare and endangered plant species to enhance their yield and quality traits. PMID:23961155

  10. Biotechnological approaches for conservation and improvement of rare and endangered plants of Saudi Arabia.

    PubMed

    Khan, Salim; Al-Qurainy, Fahad; Nadeem, Mohammad

    2012-01-01

    Genetic variation is believed to be a prerequisite for the short-and long-term survival of the plant species in their natural habitat. It depends on many environmental factors which determine the number of alleles on various loci in the genome. Therefore, it is important to understand the genetic composition and structure of the rare and endangered plant species from their natural habitat to develop successful management strategies for their conservation. However, rare and endangered plant species have low genetic diversity due to which their survival rate is decreasing in the wilds. The evaluation of genetic diversity of such species is very important for their conservation and gene manipulation. However, plant species can be conserved by in situ and in vitro methods and each has advantages and disadvantages. DNA banking can be considered as a means of complimentary method for the conservation of plant species by preserving their genomic DNA at low temperatures. Such approach of preservation of biological information provides opportunity for researchers to search novel genes and its products. Therefore, in this review we are describing some potential biotechnological approaches for the conservation and further manipulation of these rare and endangered plant species to enhance their yield and quality traits.

  11. Effects of rare earth elements and REE-binding proteins on physiological responses in plants.

    PubMed

    Liu, Dongwu; Wang, Xue; Chen, Zhiwei

    2012-02-01

    Rare earth elements (REEs), which include 17 elements in the periodic table, share chemical properties related to a similar external electronic configuration. REEs enriched fertilizers have been used in China since the 1980s. REEs could enter the cell and cell organelles, influence plant growth, and mainly be bound with the biological macromolecules. REE-binding proteins have been found in some plants. In addition, the chlorophyll activities and photosynthetic rate can be regulated by REEs. REEs could promote the protective function of cell membrane and enhance the plant resistance capability to stress produced by environmental factors, and affect the plant physiological mechanism by regulating the Ca²⁺ level in the plant cells. The focus of present review is to describe how REEs and REE-binding proteins participate in the physiological responses in plants.

  12. Generalist birds promote tropical forest regeneration and increase plant diversity via rare-biased seed dispersal.

    PubMed

    Carlo, Tomás A; Morales, Juan M

    2016-07-01

    Regenerated forests now compose over half of the world's tropical forest cover and are increasingly important as providers of ecosystem services, freshwater, and biodiversity conservation. Much of the value and functionality of regenerating forests depends on the plant diversity they contain. Tropical forest diversity is strongly shaped by mutualistic interactions between plants and fruit-eating animals (frugivores) that disperse seeds. Here we show how seed dispersal by birds can influence the speed and diversity of early successional forests in Puerto Rico. For two years, we monitored the monthly fruit production of bird-dispersed plants on a fragmented landscape, and measured seed dispersal activity of birds and plant establishment in experimental plots located in deforested areas. Two predominantly omnivorous bird species, the Northern Mockingbird (Mimus polyglottos) and the Gray Kingbird (Tyrannus dominicensis), proved critical for speeding up the establishment of woody plants and increasing the species richness and diversity of the seed rain in deforested areas. Seed dispersal by these generalists increased the odds for rare plant species to disperse and establish in experimental forest-regeneration plots. Results indicate that birds that mix fruit and insects in their diets and actively forage across open and forested habitats can play keystone roles in the regeneration of mutualistic plant-animal communities. Furthermore, our analyses reveal that rare-biased (antiapostatic) frugivory and seed dispersal is the mechanism responsible for increasing plant diversity in the early-regenerating community. © 2016 by the Ecological Society of America.

  13. Rare Plants and Animals of the Texas Hill Country: Educator's Guide.

    ERIC Educational Resources Information Center

    Texas State Dept. of Parks and Wildlife, Austin.

    Texas Hill Country is a land of fresh water springs, stony hills, and steep canyons and home to many rare plants and animals. Six activities for grades 3-5 and six activities for grades 6-12 are contained in this guide. Elementary activity highlights include using "The Lorax" by Dr. Seuss to stimulate critical thinking about…

  14. Development of protocols to inventory or monitor wildlife, fish, or rare plants

    Treesearch

    David Vesely; Brenda C. McComb; Christina D. Vojta; Lowell H. Suring; Jurai Halaj; Richard S. Holthausen; Benjamin Zuckerberg; Patricia M. Manley

    2006-01-01

    The purpose of this technical guide (hereafter referred to as the Species Protocol Technical Guide) is to provide guidelines for developing inventory and monitoring (I&M) protocols for wildlife, fish, and rare plants (WFRP) using the U.S. Department of Agriculture (USDA) Forest Service technical guide format.

  15. Climate change as an ecosystem architect: implications to rare plant ecology, conservation, and restoration

    Treesearch

    Constance I. Millar

    2003-01-01

    Recent advances in earth system sciences have revealed significant new information relevant to rare plant ecology and conservation. Analysis of climate change at high resolution with new and precise proxies of paleotemperatures reveals a picture over the past two million years of oscillatory climate change operating simultaneously at multiple timescales. Low-frequency...

  16. Managing Natural and Reintroduced Rare Plant Populations within a Large Government Reservation

    SciTech Connect

    Carlsen, T M; Paterson, L E; Alfaro, T M

    2009-07-15

    California is home to many large government reservations that have been in existence for decades. Many of these reservations were formed to support various Department of Defense and Department of Energy national defense activities. Often, only a very small percentage of the reservation is actively used for programmatic activities, resulting in large areas of intact habitat. In some cases, this has benefited rare plant populations, as surrounding lands have been developed for residential or industrial use. However, land management activities such as the suppression or active use of fire and other disturbance (such as fire trail grading) can also work to either the detriment or benefit of rare plant populations at these sites. A management regime that is beneficial to the rare plant populations of interest and is at best consistent with existing site programmatic activities, and at a minimum does not impact such activities, has the best potential for a positive outcome. As a result, some species may be 'difficult' while others may be 'easy' to manage in this context, depending on how closely the species biological requirements match the programmatic activities on the reservation. To illustrate, we compare and contrast two rare annual plant species found at Lawrence Livermore National Laboratory's Site 300. Although several populations of Amsinckia grandiflora have been restored on the site, and all populations are intensively managed, this species continues to decline. In contrast, Blepharizonia plumosa appears to take advantage of the annual controlled burns conducted on the site, and is thriving.

  17. Response of smooth rock skullcap (Scutellaria saxatilis), a globally rare plant, to fire

    Treesearch

    Cynthia D. Huebner; Kent. Karriker

    2015-01-01

    Scutellaria saxatilis Riddell (smooth rock skullcap or rock skullcap, hereafter abbreviated as SRS), a herbaceous perennial in the mint family, is a globally rare (G3) plant. In West Virginia, SRS is categorized as an S2 species (imperiled and at high risk of extinction due to a very restricted range, very few [

  18. Determining habitat potential and surveying for nine rare plant species in south-central Utah

    Treesearch

    Deborah J. Clark; Christine M. Groebner

    2001-01-01

    In south-central Utah, lands within and adjacent to Capitol Reef National Park contain populations of nine rare plant species. In an effort to enhance the combined knowledge about these species, the Bureau of Land Management, the USDA Forest Service, and the National Park Service signed an Interagency Agreement and hired an interagency biologist and field crew to...

  19. Parasite facilitates plant species coexistence in a coastal wetland.

    PubMed

    Grewell, Brenda J

    2008-06-01

    Outbreaks of infectious agents in natural ecosystems are on the rise. Understanding host-pathogen interactions and their impact on community composition may be central to the conservation of biological diversity. Infectious agents can convey both exploitive and facilitative effects that regulate host populations and community structure. Parasitic angiosperms are highly conspicuous in many plant communities, and they provide a tractable model for understanding parasite effects in multispecies communities. I examined host identity and variation in host infectivity of a holoparasitic vine (Cuscuta salina) within a California salt marsh. In a two-year parasite removal experiment, I measured the effect of C. salina on its most frequent host, a rare hemiparasite, and the plant community. C. salina clearly suppressed the dominant host, but rare plant fitness and plant species diversity were enhanced through indirect effects. Priority effects played a role in the strength of the outcome due to the timing of life history characteristics. The differential influence of parasites on the fecundity of multiple hosts can change population dynamics, benefit rare species, and alter community structure. The continuum of negative to positive consequences of parasitic interactions deserves more attention if we are to understand community dynamics and successfully restore tidal wetlands.

  20. From Agrobacterium to viral vectors: genome modification of plant cells by rare cutting restriction enzymes.

    PubMed

    Marton, Ira; Honig, Arik; Omid, Ayelet; De Costa, Noam; Marhevka, Elena; Cohen, Barry; Zuker, Amir; Vainstein, Alexander

    2013-01-01

    Researchers and biotechnologists require methods to accurately modify the genome of higher eukaryotic cells. Such modifications include, but are not limited to, site-specific mutagenesis, site-specific insertion of foreign DNA, and replacement and deletion of native sequences. Accurate genome modifications in plant species have been rather limited, with only a handful of plant species and genes being modified through the use of early genome-editing techniques. The development of rare-cutting restriction enzymes as a tool for the induction of site-specific genomic double-strand breaks and their introduction as a reliable tool for genome modification in animals, animal cells and human cell lines have paved the way for the adaptation of rare-cutting restriction enzymes to genome editing in plant cells. Indeed, the number of plant species and genes which have been successfully edited using zinc finger nucleases (ZFNs), transcription activator-like effector nucleases (TALENs) and engineered homing endonucleases is on the rise. In our review, we discuss the basics of rare-cutting restriction enzyme-mediated genome-editing technology with an emphasis on its application in plant species.

  1. Context dependency and saturating effects of loss of rare soil microbes on plant productivity.

    PubMed

    Hol, W H Gera; de Boer, Wietse; de Hollander, Mattias; Kuramae, Eiko E; Meisner, Annelein; van der Putten, Wim H

    2015-01-01

    Land use intensification is associated with loss of biodiversity and altered ecosystem functioning. Until now most studies on the relationship between biodiversity and ecosystem functioning focused on random loss of species, while loss of rare species that usually are the first to disappear received less attention. Here we test if the effect of rare microbial species loss on plant productivity depends on the origin of the microbial soil community. Soils were sampled from three land use types at two farms. Microbial communities with increasing loss of rare species were created by inoculating sterilized soils with serially diluted soil suspensions. After 8 months of incubation, the effects of the different soil communities on abiotic soil properties, soil processes, microbial community composition, and plant productivity was measured. Dilution treatments resulted in increasing species loss, which was in relation to abundance of bacteria in the original field soil, without affecting most of the other soil parameters and processes. Microbial species loss affected plant biomass positively, negatively or not at all, depending on soil origin, but not on land use history. Even within fields the effects of dilution on plant biomass varied between replicates, suggesting heterogeneity in microbial community composition. The effects of medium and severe species loss on plant biomass were similar, pointing toward a saturating effect of species loss. We conclude that changes in the composition of the soil microbial community, including rare species loss, can affect plant productivity, depending on the composition of the initial microbial community. Future work on the relation between function and species loss effects should address this variation by including multiple sampling origins.

  2. Context dependency and saturating effects of loss of rare soil microbes on plant productivity

    PubMed Central

    Hol, W. H. Gera; de Boer, Wietse; de Hollander, Mattias; Kuramae, Eiko E.; Meisner, Annelein; van der Putten, Wim H.

    2015-01-01

    Land use intensification is associated with loss of biodiversity and altered ecosystem functioning. Until now most studies on the relationship between biodiversity and ecosystem functioning focused on random loss of species, while loss of rare species that usually are the first to disappear received less attention. Here we test if the effect of rare microbial species loss on plant productivity depends on the origin of the microbial soil community. Soils were sampled from three land use types at two farms. Microbial communities with increasing loss of rare species were created by inoculating sterilized soils with serially diluted soil suspensions. After 8 months of incubation, the effects of the different soil communities on abiotic soil properties, soil processes, microbial community composition, and plant productivity was measured. Dilution treatments resulted in increasing species loss, which was in relation to abundance of bacteria in the original field soil, without affecting most of the other soil parameters and processes. Microbial species loss affected plant biomass positively, negatively or not at all, depending on soil origin, but not on land use history. Even within fields the effects of dilution on plant biomass varied between replicates, suggesting heterogeneity in microbial community composition. The effects of medium and severe species loss on plant biomass were similar, pointing toward a saturating effect of species loss. We conclude that changes in the composition of the soil microbial community, including rare species loss, can affect plant productivity, depending on the composition of the initial microbial community. Future work on the relation between function and species loss effects should address this variation by including multiple sampling origins. PMID:26175749

  3. Rare earths: atmospheric signatures for oil-fired power plants and refineries

    SciTech Connect

    Olmez, I.; Gordon, G.E.

    1985-09-06

    The concentration pattern of rare earth elements on fine airborne particles (less than 2.5 micrometers in diameter) is distorted from the crustal abundance pattern in areas influenced by emissions from oil-fired plants and refineries. For example, the ratio of lanthanum to samarium is often greater than 20 compared to a crustal ratio less than 6. The unusual pattern apparently results from the distribution of rare earths in zeolite catalysts used in refining oil. Oil industry emissions perturb the rare earth pattern even at remote locations such as the Mauna Loa Observatory in Hawaii. Rare earth ratios are probably better for long-range tracing of oil emissions than vanadium and nickel concentrations because the ratios of rare earths on fine particles are probably not influenced by deposition and other fractionating processes. Emissions from oil-fired plants can be differentiated from those of refineries on an urban scale by the much smaller amounts of vanadium in the latter. 30 references, 1 figure, 3 tables.

  4. Mobility of boron-polyol complexes in the hemiparasitic association between Rhinanthus minor and Hordeum vulgare: the effects of nitrogen nutrition.

    PubMed

    Jiang, Fan; Jeschke, W Dieter; Hartung, Wolfram; Cameron, Duncan D

    2008-09-01

    Boron (B) is an essential nutrient required for plant growth and physiological processes. Long-distance B transport is facilitated by the formation of B-polyol complexes. We investigated B uptake and distribution in response to differing levels of exogenous nitrogen supply in the hemiparasitic association between Rhinanthus minor and Hordeum vulgare (barley) and in unparasitised barley and single Rhinanthus plants. In this system, the polyol mannitol is the major assimilate in Rhinanthus, whereas polyols are not detectable in barley. Furthermore, previous studies have shown that the accumulation of polyols within Rhinanthus is negatively affected by the application of exogenous nitrogen. Within the association, the strongest accumulation of B was detected in lateral buds and inflorescences of Rhinanthus, consistent with the greatest B demand in strong sink organs supplied through the phloem that contain high concentrations of mannitol. In the host, the strongest B accumulation was found in xylem-supported leaf lamellae. Roots and sheaths did not accumulate substantial amounts of B, while re-circulation of B through the phloem vessels accounted for only 10% (unparasitised) and 8% (parasitised) of the xylem sap-imported B in the mannitol-free barley hosts. In contrast, 53% (attached) and 39% (in the absence of a host) of the xylem sap-imported B was re-circulated in the phloem in the mannitol-rich Rhinanthus. We therefore present the first quantitative uptake and flow models of long-distance B transport in polyol-rich and polyol-free plants. Our findings are consistent with a close relationship between B re-translocation and mannitol concentrations in phloem vessels.

  5. Selective Foraging by Pogonomyrmex salinus (Hymenoptera: Formicidae) in Semiarid Grassland: Implications for a Rare Plant.

    PubMed

    Schmasow, Matthew S; Robertson, Ian C

    2016-08-01

    Selective foraging by granivores can have important consequences for the structure and composition of plant communities, and potentially severe consequences for rare plant species. To understand how granivore foraging behavior affects common and rare plant species, diet selection should be viewed relative to the availability of alternative seed options, and with consideration of the individual attributes of those seeds (e.g., morphology, nutrient content). We examined the foraging decisions of Owyhee harvester ants, Pogonomyrmex salinus (Olsen), in semiarid grassland dominated by two species of grass, Poa secunda and Bromus tectorum, and two species of mustard, Sisymbrium altissimum and Lepidium papilliferum The latter is a rare plant endemic to southwestern Idaho, and its seeds are readily consumed by P. salinus We examined the diets of P. salinus colonies in June and July over three years and compared these values to the weekly availability of seeds on the ground in a 3-12 -m radius around individual ant colonies. Small-seeded species (P. secunda, S. altissimum, and L. papilliferum) were usually overrepresented in the diet of ants relative to their availability, whereas the large seeds of B. tectorum were largely avoided despite being abundant and nutritious. The reduced travel time associated with carrying small seeds may overshadow differences in nutritional content among seed types, except in times when small seeds are in short supply. Lepidium papilliferum appears particularly vulnerable to seed predation, likely in part because it grows in dense patches that are easily exploited by foragers.

  6. Topography- and management-mediated resource gradients maintain rare and common plant diversity around paddy terraces.

    PubMed

    Uematsu, Yuta; Ushimaru, Atushi

    2013-09-01

    Examining the causes of interspecific differences in susceptibility to bidirectional land-use changes (land abandonment and use-intensification) is important for understanding the mechanisms of global biodiversity loss in agricultural landscapes. We tested the hypothesis that rare (endangered) plant species prefer wet and oligotrophic areas within topography- and management-mediated resource (soil water content, nutrient, and aboveground biomass) gradients, making them more susceptible to both abandonment and use-intensification of agricultural lands. We demonstrated that topography and management practices generated resource gradients in seminatural grasslands around traditional paddy terraces. Terraced topography and management practices produced a soil moisture gradient within levees and a nutrient gradient within paddy terraces. Both total and rare species diversity increased with soil water content. Total species diversity increased in more eutrophied areas with low aboveground biomass, whereas rare species diversity was high under oligotrophic conditions. Rare and common species were differentially distributed along the human-induced nutrient gradient, with rare species preferring wet, nutrient-poor environments in the agricultural landscapes studied. We suggest that conservation efforts should concentrate on wet, nutrient-poor areas within such landscapes, which can be located easily using land-use and topography maps. This strategy would reduce the costs of finding and conserving rare grassland species in a given agricultural landscape.

  7. Trait space of rare plants in a fire-dependent ecosystem.

    PubMed

    Ames, Gregory M; Wall, Wade A; Hohmann, Matthew G; Wright, Justin P

    2016-11-21

    The causes of species rarity are of critical concern because of the high extinction risk associated with rarity. Studies examining individual rare species have limited generality, whereas trait-based approaches offer a means to identify functional causes of rarity that can be applied to communities with disparate species pools. Differences in functional traits between rare and common species may be indicative of the functional causes of species rarity and may therefore be useful in crafting species conservation strategies. However, there is a conspicuous lack of studies comparing the functional traits of rare species and co-occurring common species. We measured 18 important functional traits for 19 rare and 134 common understory plant species from North Carolina's Sandhills region and compared their trait distributions to determine whether there are significant functional differences that may explain species rarity. Flowering, fire, and tissue-chemistry traits differed significantly between rare and common, co-occurring species. Differences in specific traits suggest that fire suppression has driven rarity in this system and that changes to the timing and severity of prescribed fire may improve conservation success. Our method provides a useful tool to prioritize conservation efforts in other systems based on the likelihood that rare species are functionally capable of persisting.

  8. Screening of some rare endemic Italian plants for inhibitory activity on 5-lipoxygenase.

    PubMed

    Prieto, José-María; Bader, Ammar; Martini, Francesca; Ríos, José-Luis; Morelli, Ivano

    2005-12-01

    The extracts of four rare plants found on the islands of Sicily, Vulcano and Marettimo, Southern Italy, were screened for their inhibitory effect on the production of leukotriene B4 by 5-lipoxygenase in intact cells. The methanol extracts of pods of Cytisus aeolicus and aerial parts of Thymus richardii were the most active extracts, inhibiting almost completely the leukotriene B4 production at 200 and 50 microg/ml, respectively.

  9. Rare Earth Element Concentrations from Wells at the Don A. Campbell Geothermal Plant, Nevada

    DOE Data Explorer

    Fowler, Andrew; Zierenberg, Robert

    2016-12-09

    * Requires permission of originators for use. Rare earth element concentrations in thermal springs from the wells at the Don A. Campbell geothermal plant, Nevada. Samples taken from geothermal wells 85-11, 65-11, 54-11, and 64-11. Includes pH and concentrations for Cerium, Dysprosium, Erbium, Europium, Gadolinium, Holmium, Lanthanum, Lutetium, Neodymium, Praseodymium, Samarium, Terbium, Thulium, Yttrium, and Ytterbium. Samples from Don A. Campbell, Nevada collected on October 14, 2016.

  10. Multiplex single-cell quantification of rare RNA transcripts from protoplasts in a model plant system.

    PubMed

    Kadam, Ulhas S; Schulz, Burkhard; Irudayaraj, Joseph M K

    2017-06-01

    Here we demonstrate multiplex and simultaneous detection of four different rare RNA species from plant, Arabidopsis thaliana, using surface-enhanced Raman spectroscopy (SERS) and gold nanoprobes at single-cell resolution. We show the applicability of nanoparticle-based Raman spectroscopic sensor to study intracellular RNA copies. First, we demonstrate that gold-nanoparticles decorated with Raman probes and carrying specific nucleic acid probe sequences can be uptaken by the protoplasts. We confirm the internalization of gold nanoprobes by transmission electron microscopy, inductively-coupled plasma-mass spectrometry and fluorescence imaging. Second, we show the utility of a SERS platform to monitor individual alternatively spliced (AS) variants and miRNA copies within single cells. Finally, the distinctive spectral features of Raman-active dyes were exploited for multiplex analysis of AtPTB2, AtDCL2, miR156a and miR172a. Furthermore, single-cell studies were validated by in vitro quantification and evaluation of nanotoxicity of gold probes. Raman tag functionalized gold nanosensors yielded an approach for the tracking of rare RNAs within the protoplasts. The SERS-based approach for quantification of RNAs has the capability to be a highly sensitive, accurate and discerning method for single-cell studies including AS variants quantification and rare miRNA detection in specific plant species. © 2017 The Authors The Plant Journal © 2017 John Wiley & Sons Ltd.

  11. Reduced fecundity in small populations of the rare plant Gentianopsis ciliate (Gentianaceae)

    USGS Publications Warehouse

    Robbins, C.S.

    1983-01-01

    Habitat destruction is the main cause for the biodiversity crisis. Surviving populations are often fragmented, i.e., small and isolated from each other. Reproduction of plants in small populations is often reduced, and this has been attributed to inbreeding depression, reduced attractiveness for pollinators, and reduced habitat quality in small populations. Here we present data on the effects of fragmentation on the rare, self-compatible perennial herb Gentianopsis ciliata (Gentianaceae), a species with very small and presumably well-dispersed seeds. We studied the relationship between population size, plant size, and the number of flowers produced in 63 populations from 1996-1998. In one of the years, leaf and flower size and the number of seeds produced per fruit was studied in a subset of 25 populations. Plant size, flower size, and the number of seeds per fruit and per plant increased with population size, whereas leaf length and the number of flowers per plant did not. The effects of population size on reproduction and on flower size remained significant if the effects were adjusted for differences in plant size, indicating that they could not be explained by differences in habitat quality. The strongly reduced reproduction in small populations may be due to pollination limitation, while the reduced flower size could indicate genetic effects.

  12. Reduced fecundity in small populations of the rare plant Gentianopsis ciliate (Gentianaceae)

    USGS Publications Warehouse

    Kery, M.; Matthies, D.

    2004-01-01

    Habitat destruction is the main cause for the biodiversity crisis. Surviving populations are often fragmented, i.e., small and isolated from each other. Reproduction of plants in small populations is often reduced, and this has been attributed to inbreeding depression, reduced attractiveness for pollinators, and reduced habitat quality in small populations. Here we present data on the effects of fragmentation on the rare, self-compatible perennial herb Gentianopsis ciliata (Gentianaceae), a species with very small and presumably well-dispersed seeds. We studied the relationship between population size, plant size, and the number of flowers produced in 63 populations from 1996-1998. In one of the years, leaf and flower size and the number of seeds produced per fruit was studied in a subset of 25 populations. Plant size, flower size, and the number of seeds per fruit and per plant increased with population size, whereas leaf length and the number of flowers per plant did not. The effects of population size on reproduction and on flower size remained significant if the effects were adjusted for differences in plant size, indicating that they could not be explained by differences in habitat quality. The strongly reduced reproduction in small populations may be due to pollination limitation, while the reduced flower size could indicate genetic effects.

  13. Reintroduction of rare arable plants by seed transfer. What are the optimal sowing rates?

    PubMed

    Lang, Marion; Prestele, Julia; Fischer, Christina; Kollmann, Johannes; Albrecht, Harald

    2016-08-01

    During the past decades, agro-biodiversity has markedly declined and some species are close to extinction in large parts of Europe. Reintroduction of rare arable plant species in suitable habitats could counteract this negative trend. The study investigates optimal sowing rates of three endangered species (Legousia speculum-veneris (L.) Chaix, Consolida regalis Gray, and Lithospermum arvense L.), in terms of establishment success, seed production, and crop yield losses.A field experiment with partial additive design was performed in an organically managed winter rye stand with study species added in ten sowing rates of 5-10,000 seeds m(-2). They were sown as a single species or as a three-species mixture (pure vs. mixed sowing) and with vs. without removal of spontaneous weeds. Winter rye was sown at a fixed rate of 350 grains m(-2). Performance of the study species was assessed as plant establishment and seed production. Crop response was determined as grain yield.Plant numbers and seed production were significantly affected by the sowing rate, but not by sowing type (pure vs. mixed sowing of the three study species), and weed removal. All rare arable plant species established and reproduced at sowing rates >25 seeds m(-2), with best performance of L. speculum-veneris. Negative density effects occurred to some extent for plant establishment and more markedly for seed production.The impact of the three study species on crop yield followed sigmoidal functions. Depending on the species, a yield loss of 10% occurred at >100 seeds m(-2). Synthesis and applications: The study shows that reintroduction of rare arable plants by seed transfer is a suitable method to establish them on extensively managed fields, for example, in organic farms with low nutrient level and without mechanical weed control. Sowing rates of 100 seeds m(-2) for C. regalis and L. arvense, and 50 seeds m(-2) for L. speculum-veneris are recommended, to achieve successful establishment

  14. Impacts of invasive nonnative plant species on the rare forest herb Scutellaria montana

    NASA Astrophysics Data System (ADS)

    Sikkema, Jordan J.; Boyd, Jennifer N.

    2015-11-01

    Invasive plant species and overabundant herbivore populations have the potential to significantly impact rare plant species given their increased risk for local extirpation and extinction. We used interacting invasive species removal and grazer exclusion treatments replicated across two locations in an occurrence of rare Scutellaria montana (large-flowered skullcap) in Chattanooga, Tennessee, USA, to assess: 1) competition by invasive Ligustrum sinense (Chinese privet) and Lonicera japonica (Japanese honeysuckle) and 2) the role of invasive species in mediating Oedocoilus virginianus (white-tailed deer) grazing of S. montana. Contrary to our hypothesis that invasive species presence would suppress S. montana directly via competition, S. montana individuals experienced a seasonal increase in stem height when invasive species were intact but not when invasive species were removed. Marginally significant results indicated that invasive species may afford S. montana protection from grazers, and we suggest that invasive species also could protect S. montana from smaller herbivores and/or positively influence abiotic conditions. In contrast to growth responses, S. montana individuals protected from O. virginianus exhibited a decrease in flowering between seasons relative to unprotected plants, but invasive species did not affect this variable. Although it has been suggested that invasive plant species may negatively influence S. montana growth and fecundity, our findings do not support related concerns. As such, we suggest that invasive species eradication efforts in S. montana habitat could be more detrimental than positive due to associated disturbance. However, the low level of invasion of our study site may not be representative of potential interference in more heavily infested habitat.

  15. [Study on species and distribution of flora of national rare and endangered medicinal plant in the Three Gorges area].

    PubMed

    Chen, Shao-Cheng

    2013-04-01

    According to the China Plant Red Data Book and National Key Protected Wild Plants, the distribution of the rare and endangered plants and national conservative plants in the Three Gorges area were investigated and statistically analyzed. Its floristic composition and characteristics of geographical distribution were explored. As a result, a total of 97 species of medicinal flora belonging to rare and endangered national protection plants were found in the Three Gorges area. They come from 81 genera of 46 families. Their vertical distribution is obvious and horizontal distribution has discontinuous overlap. There are many ancient relict medicinal plants in the Three Gorges area. These medicinal plants have obvious temperate characteristics, and are easily found at warm and moist ravines and hillsides; The proportion of tree is much higher than that of herb, vine, shrub and fern. Most of them belong to specific and monotypic genera.

  16. Towards a more holistic research approach to plant conservation: the case of rare plants on oceanic islands.

    PubMed

    Silva, Luís; Dias, Elisabete Furtado; Sardos, Julie; Azevedo, Eduardo Brito; Schaefer, Hanno; Moura, Mónica

    2015-06-11

    Research dedicated to rare endemic plants is usually focused on one given aspect. However, holistic studies, addressing several key issues, might be more useful, supporting management programmes while unravelling basic knowledge about ecological and population-level processes. A more comprehensive approach to research is proposed, encompassing: phylogenetics/systematics, pollination biology and seed dispersal, propagation, population genetics, species distribution models (SDMs), threats and monitoring. We present a holistic study dedicated to Veronica dabneyi Hochst. ex Seub., an endangered chamaephyte endemic to the Azores. Veronica dabneyi was mainly found associated with other endemic taxa; however, invasive plants were also present and together with introduced cattle, goats and rabbits are a major threat. Most populations grow at somewhat rocky and steep locations that appeared to work as refuges. Seed set in the wild was generally high and recruitment of young plants from seed seemed to be frequent. In the laboratory, it was possible to germinate and fully develop V. dabneyi seedlings, which were planted at their site of origin. No dormancy was detected and time for 50 % germination was affected by incubation temperature. Eight new microsatellite markers were applied to 72 individuals from 7 sites. A considerable degree of admixture was found between samples from the two islands Flores and Corvo, with 98 % of the genetic variability allocated within populations. Levels of heterozygosity were high and no evidence of inbreeding was found. Species distribution models based on climatic and topographic variables allowed the estimation of the potential distribution of V. dabneyi on Flores and Corvo using ecological niche factor analysis and Maxent. The inclusion of land-use variables only slightly increased the information explained by the models. Projection of the expected habitat in Faial largely coincided with the only historic record of V. dabneyi on that island

  17. Towards a more holistic research approach to plant conservation: the case of rare plants on oceanic islands

    PubMed Central

    Silva, Luís; Dias, Elisabete Furtado; Sardos, Julie; Azevedo, Eduardo Brito; Schaefer, Hanno; Moura, Mónica

    2015-01-01

    Research dedicated to rare endemic plants is usually focused on one given aspect. However, holistic studies, addressing several key issues, might be more useful, supporting management programmes while unravelling basic knowledge about ecological and population-level processes. A more comprehensive approach to research is proposed, encompassing: phylogenetics/systematics, pollination biology and seed dispersal, propagation, population genetics, species distribution models (SDMs), threats and monitoring. We present a holistic study dedicated to Veronica dabneyi Hochst. ex Seub., an endangered chamaephyte endemic to the Azores. Veronica dabneyi was mainly found associated with other endemic taxa; however, invasive plants were also present and together with introduced cattle, goats and rabbits are a major threat. Most populations grow at somewhat rocky and steep locations that appeared to work as refuges. Seed set in the wild was generally high and recruitment of young plants from seed seemed to be frequent. In the laboratory, it was possible to germinate and fully develop V. dabneyi seedlings, which were planted at their site of origin. No dormancy was detected and time for 50 % germination was affected by incubation temperature. Eight new microsatellite markers were applied to 72 individuals from 7 sites. A considerable degree of admixture was found between samples from the two islands Flores and Corvo, with 98 % of the genetic variability allocated within populations. Levels of heterozygosity were high and no evidence of inbreeding was found. Species distribution models based on climatic and topographic variables allowed the estimation of the potential distribution of V. dabneyi on Flores and Corvo using ecological niche factor analysis and Maxent. The inclusion of land-use variables only slightly increased the information explained by the models. Projection of the expected habitat in Faial largely coincided with the only historic record of V. dabneyi on that island

  18. Phytoextraction of rare earth elements in herbaceous plant species growing close to roads.

    PubMed

    Mikołajczak, Patrycja; Borowiak, Klaudia; Niedzielski, Przemysław

    2017-06-01

    The aim of study was to determine the phytoextraction of rare earth elements (REEs) to roots, stems and leaves of five herbaceous plant species (Achillea millefolium L., Artemisia vulgaris L., Papaver rhoeas L., Taraxacum officinale AND Tripleurospermum inodorum), growing in four areas located in close proximity to a road with varied traffic intensity. Additionally, the relationship between road traffic intensity, REE concentration in soil and the content of these elements in plant organs was estimated. A. vulgaris and P. rhoeas were able to effectively transport REEs in their leaves, independently of area collection. The highest content of REEs was observed in P. rhoeas leaves and T. inodorum roots. Generally, HREEs were accumulated in P. rhoeas roots and leaves and also in the stems of T. inodorum and T. officinale, whereas LREEs were accumulated in T. inodorum roots and T. officinale stems. It is worth underlining that there was a clear relationship between road traffic intensity and REE, HREE and LREE concentration in soil. No positive correlation was found between the concentration of these elements in soil and their content in plants, with the exception of T. officinale. An effective transport of REEs from the root system to leaves was observed, what points to the possible ability of some of the tested plant species to remove REEs from soils near roads.

  19. Effective prey attraction in the rare Drosophyllum lusitanicum, a flypaper-trap carnivorous plant.

    PubMed

    Bertol, Nils; Paniw, Maria; Ojeda, Fernando

    2015-05-01

    Carnivorous plants have unusually modified leaves to trap insects as an adaptation to low-nutrient environments. Disparate mechanisms have been suggested as luring traits to attract prey insects into their deadly leaves, ranging from very elaborate to none at all. Drosophyllum lusitanicum is a rare carnivorous plant with a common flypaper-trap mechanism. Here we tested whether Drosophyllum plants lure prey insects into their leaves or they act just as passive traps. We compared prey capture between live, potted plants and Drosophyllum-shaped artificial mimics coated with odorless glue. Since this species is insect-pollinated, we also explored the possible existence of a pollinator-prey conflict by quantifying the similarity between the pollination and prey guilds in a natural population. All experiments were done in southern Spain. The sticky leaves of Drosophyllum captured significantly more prey than mimics, particularly small dipterans. Prey attraction, likely exerted by scent or visual cues, seems to be unrelated to pollinator attraction by flowers, as inferred from the low similarity between pollinator and prey insect faunas found in this species. Our results illustrate the effectiveness of this carnivorous species at attracting insects to their flypaper-trap leaves. © 2015 Botanical Society of America, Inc.

  20. Abundantly and rarely expressed Lhc protein genes exhibit distinct regulation patterns in plants.

    PubMed

    Klimmek, Frank; Sjödin, Andreas; Noutsos, Christos; Leister, Dario; Jansson, Stefan

    2006-03-01

    We have analyzed gene regulation of the Lhc supergene family in poplar (Populus spp.) and Arabidopsis (Arabidopsis thaliana) using digital expression profiling. Multivariate analysis of the tissue-specific, environmental, and developmental Lhc expression patterns in Arabidopsis and poplar was employed to characterize four rarely expressed Lhc genes, Lhca5, Lhca6, Lhcb7, and Lhcb4.3. Those genes have high expression levels under different conditions and in different tissues than the abundantly expressed Lhca1 to 4 and Lhcb1 to 6 genes that code for the 10 major types of higher plant light-harvesting proteins. However, in some of the datasets analyzed, the Lhcb4 and Lhcb6 genes as well as an Arabidopsis gene not present in poplar (Lhcb2.3) exhibited minor differences to the main cooperative Lhc gene expression pattern. The pattern of the rarely expressed Lhc genes was always found to be more similar to that of PsbS and the various light-harvesting-like genes, which might indicate distinct physiological functions for the rarely and abundantly expressed Lhc proteins. The previously undetected Lhcb7 gene encodes a novel plant Lhcb-type protein that possibly contains an additional, fourth, transmembrane N-terminal helix with a highly conserved motif. As the Lhcb4.3 gene seems to be present only in Eurosid species and as its regulation pattern varies significantly from that of Lhcb4.1 and Lhcb4.2, we conclude it to encode a distinct Lhc protein type, Lhcb8.

  1. Post-mortem ecosystem engineering by oysters creates habitat for a rare marsh plant.

    PubMed

    Guo, Hongyu; Pennings, Steven C

    2012-11-01

    Oysters are ecosystem engineers in marine ecosystems, but the functions of oyster shell deposits in intertidal salt marshes are not well understood. The annual plant Suaeda linearis is associated with oyster shell deposits in Georgia salt marshes. We hypothesized that oyster shell deposits promoted the distribution of Suaeda linearis by engineering soil conditions unfavorable to dominant salt marsh plants of the region (the shrub Borrichia frutescens, the rush Juncus roemerianus, and the grass Spartina alterniflora). We tested this hypothesis using common garden pot experiments and field transplant experiments. Suaeda linearis thrived in Borrichia frutescens stands in the absence of neighbors, but was suppressed by Borrichia frutescens in the with-neighbor treatment, suggesting that Suaeda linearis was excluded from Borrichia frutescens stands by interspecific competition. Suaeda linearis plants all died in Juncus roemerianus and Spartina alterniflora stands, regardless of neighbor treatments, indicating that Suaeda linearis is excluded from these habitats by physical stress (likely water-logging). In contrast, Borrichia frutescens, Juncus roemerianus, and Spartina alterniflora all performed poorly in Suaeda linearis stands regardless of neighbor treatments, probably due to physical stresses such as low soil water content and low organic matter content. Thus, oyster shell deposits play an important ecosystem engineering role in influencing salt marsh plant communities by providing a unique niche for Suaeda linearis, which otherwise would be rare or absent in salt marshes in the southeastern US. Since the success of Suaeda linearis is linked to the success of oysters, efforts to protect and restore oyster reefs may also benefit salt marsh plant communities.

  2. Biogeography and decline of rare plants in New England: historical evidence and contemporary monitoring.

    PubMed

    Farnsworth, Elizabeth J; Ogurcak, Danielle E

    2006-08-01

    Detecting range shifts and contractions is critical for determining the conservation priority of rare and declining taxa. However, data on rare species occurrences frequently lack precise information on locations and habitats and may present a biased picture of biogeographic distributions and presumed habitat preferences. Herbarium or museum specimen data, which otherwise could be useful proxies for detecting temporal trends and spatial patterns in species distributions, pose particular challenges. Using data from herbaria and Natural Heritage Programs on numbers of occurrences within individual municipalities (towns, cities, or townships), we quantified temporal changes in the estimated distributions of 110 rare plant species in the six New England (USA) states. We used the partial Solow equation and a nonparametric test to estimate the probability of observing multiple absences (gaps in the collection record) if a given population was actually still extant. Bayes' Theorem was used to estimate the probability that occurrences were misclassified as extinct. Using the probabilities obtained from these three methods, we eliminated taxa with high probabilities of pseudo-absence (that would yield an inaccurate profile of species distributions), narrowing the set for final analysis to 71 taxa. We then expressed occurrences as centroids of town polygons and estimated current and historical range areas (extents of occurrence as defined by alpha-hulls inscribing occurrences), mean distances between occurrences, and latitudinal and longitudinal range boundaries. Using a geographic information system, we modeled first, second, and third circular standard deviational polygons around the mean center of the historical range. Examining the distribution of current occurrences within each standard deviational polygon, we asked whether ranges were collapsing to a center, expanding, fragmenting, or contracting to a margin of the former range. Extant ranges of the species were, on

  3. Responses of plant calmodulin to endocytosis induced by rare earth elements.

    PubMed

    Wang, Lihong; Cheng, Mengzhu; Chu, Yunxia; Li, Xiaodong; Chen, David D Y; Huang, Xiaohua; Zhou, Qing

    2016-07-01

    The wide application of rare earth elements (REEs) have led to their diffusion and accumulation in the environment. The activation of endocytosis is the primary response of plant cells to REEs. Calmodulin (CaM), as an important substance in calcium (Ca) signaling systems, regulating almost all of the physiological activities in plants, such as cellular metabolism, cell growth and division. However, the response of CaM to endocytosis activated by REEs remains unknown. By using immunofluorescence labeling and a confocal laser scanning microscope, we found that trivalent lanthanum [La(III)], an REE ion, affected the expression of CaM in endocytosis. Using circular dichroism, X-ray photoelectron spectroscopy and computer simulations, we demonstrated that a low concentration of La(III) could interact with extracellular CaM by electrostatic attraction and was then bound to two Ca-binding sites of CaM, making the molecular structure more compact and orderly, whereas a high concentration of La(III) could be coordinated with cytoplasmic CaM or bound to other Ca-binding sites, making the molecular structure more loose and disorderly. Our results provide a reference for revealing the action mechanisms of REEs in plant cells.

  4. Geographic profiling to assess the risk of rare plant poaching in natural areas.

    PubMed

    Young, John A; van Manen, Frank T; Thatcher, Cindy A

    2011-09-01

    We demonstrate the use of an expert-assisted spatial model to examine geographic factors influencing the poaching risk of a rare plant (American ginseng, Panax quinquefolius L.) in Shenandoah National Park, Virginia, USA. Following principles of the analytic hierarchy process (AHP), we identified a hierarchy of 11 geographic factors deemed important to poaching risk and requested law enforcement personnel of the National Park Service to rank those factors in a series of pair-wise comparisons. We used those comparisons to determine statistical weightings of each factor and combined them into a spatial model predicting poaching risk. We tested the model using 69 locations of previous poaching incidents recorded by law enforcement personnel. These locations occurred more frequently in areas predicted by the model to have a higher risk of poaching than random locations. The results of our study can be used to evaluate resource protection strategies and to target law enforcement activities.

  5. Geographic Profiling to Assess the Risk of Rare Plant Poaching in Natural Areas

    NASA Astrophysics Data System (ADS)

    Young, John A.; van Manen, Frank T.; Thatcher, Cindy A.

    2011-09-01

    We demonstrate the use of an expert-assisted spatial model to examine geographic factors influencing the poaching risk of a rare plant (American ginseng, Panax quinquefolius L.) in Shenandoah National Park, Virginia, USA. Following principles of the analytic hierarchy process (AHP), we identified a hierarchy of 11 geographic factors deemed important to poaching risk and requested law enforcement personnel of the National Park Service to rank those factors in a series of pair-wise comparisons. We used those comparisons to determine statistical weightings of each factor and combined them into a spatial model predicting poaching risk. We tested the model using 69 locations of previous poaching incidents recorded by law enforcement personnel. These locations occurred more frequently in areas predicted by the model to have a higher risk of poaching than random locations. The results of our study can be used to evaluate resource protection strategies and to target law enforcement activities.

  6. Effects of Some Rare Elements on Nicotine Content of the Tobacco Plant

    PubMed Central

    Tso, T. C.; Sorokin, T. P.; Engelhaupt, M. E.

    1973-01-01

    Fifty-four rare elements were tested for their effects on the nicotine level of tobacco (Nicotiana tabacum L.) plants grown in solution culture. Be, Cu, Pd, Pt, and Sm definitely increased nicotine yield (over 25%), whereas Bi, Co, Ho, Pb, Ni, Rb, Ag, Tl, Sn, U. V. and Zr definitely decreased nicotine yield. Cs, Er, Li, Rh, Ru, Se, Sr, Ti, and Yb possibly increased (less than 25%) nicotine yield, whereas As, Ce, Cr, Dy, Gd, I, Mo, Nd, Re, Ta, and Th possibly decreased nicotine yield. Other elements including Al, Ge, Au, Hf, In, Ir, La, Lu, Hg, Os, Pr, Sc, Te, Tb, Tm, W, and Zn showed no significant effects. PMID:16658414

  7. Resource management plan for the Oak Ridge Reservation. Volume 29, Rare plants on the Oak Ridge Reservation

    SciTech Connect

    Cunningham, M.; Pounds, L.; Oberholster, S.; Parr, P.; Mann, L.; Edwards, L.; Rosensteel, B.

    1993-08-01

    Rare plant species listed by state or federal agencies and found on or near the Department of Energy`s Oak Ridge Reservation (ORR) are identified. Seventeen species present on the ORR are listed by the Tennessee Department of Environment and Conservation as either endangered, threatened, or of special concern. Four of these are under review by the US Fish and Wildlife Service for possible listing as threatened or endangered species. Ten species listed by the state occur near and may be present on the ORR; four are endangered in Tennessee, and one is a candidate for federal listing. A range of habitats supports the rare taxa on the ORR: River bluffs, calcareous barrens, wetlands, and deciduous forest. Sites for listed rare species on the ORR have been designated as Research Park Natural Areas. Consideration of rare plant habitats is an important component of resource management and land-use planning; protection of rare species in their natural habitat is the best method of ensuring their long-term survival. In addition, the National Environmental Policy Act requires that federally funded projects avoid or mitigate impacts to listed species. The list of rare plant species and their location on the ORR should be considered provisional because the entire ORR has not been surveyed, and state and federal status of all species continues to be updated.

  8. Predicting rare plant occurrence in Great Smoky Mountains National Park, USA

    USGS Publications Warehouse

    Boetsch, J.R.; van Manen, Frank T.; Clark, Joseph D.

    2003-01-01

    We investigated the applicability of biometric habitat modeling to rare plant inventory and conservation by developing and field testing a geographically explicit model for Cardamine clematitis Shuttleworth ex A. Gray (mountain bittercress), an endemic plant of the southern Blue Ridge Mountains, USA. For each of 187 confirmed coordinates for C. clematitis in Great Smoky Mountains National Park, 13 habitat variables were measured with a geographic information system. These data were used to calculate Mahalanobis distances for each 30-m x 30-m pixel within the study area; small values of Mahalanobis distance represented site conditions similar to those of known locations of C. clematitis, whereas larger distance values represented dissimilar conditions. Following model development, we tested model performance by sampling 120 randomly distributed plots for C. clematitis presence. Logistic regression showed that Mahalanobis distance values were strongly related to C. clematitis occurrence (P = 0.039). Overall, 75% of all known occurrences of C. clematitis had associated Mahalanobis distance values below 17.7, and 95% of all occurrences were below 33.8; the median Mahalanobis distance value for the study area as a whole was 40.0. A habitat suitability cutoff value was defined which identified roughly 23,640 ha (19.5% of the study area) as suitable habitat. Although the model successfully predicted species absence in test plots with high Mahalanobis distance values, many sites with low values did not contain C. clematitis. Only 16.2% of test plots below the habitat suitability cutoff contained C. clematitis. The absence of C. clematitis from sites with low Mahalanobis distance values (low specificity) is not necessarily indicative of a poor model; metapopulation processes (e.g., recolonizations, local extinctions) have been shown to play a major role in presence or absence of many plant species. That may be partially the case with our model as evidenced by a relationship

  9. Modeling Spatial Distribution of a Rare and Endangered Plant Species (Brainea insignis) in Central Taiwan

    NASA Astrophysics Data System (ADS)

    Wang, W.-C.; Lo, N.-J.; Chang, W.-I.; Huang, K.-Y.

    2012-07-01

    With an increase in the rate of species extinction, we should choose right methods that are sustainable on the basis of appropriate science and human needs to conserve ecosystems and rare species. Species distribution modeling (SDM) uses 3S technology and statistics and becomes increasingly important in ecology. Brainea insignis (cycad-fern, CF) has been categorized a rare, endangered plant species, and thus was chosen as a target for the study. Five sampling schemes were created with different combinations of CF samples collected from three sites in Huisun forest station and one site, 10 km farther north from Huisun. Four models, MAXENT, GARP, generalized linear models (GLM), and discriminant analysis (DA), were developed based on topographic variables, and were evaluated by five sampling schemes. The accuracy of MAXENT was the highest, followed by GLM and GARP, and DA was the lowest. More importantly, they can identify the potential habitat less than 10% of the study area in the first round of SDM, thereby prioritizing either the field-survey area where microclimatic, edaphic or biotic data can be collected for refining predictions of potential habitat in the later rounds of SDM or search areas for new population discovery. However, it was shown unlikely to extend spatial patterns of CFs from one area to another with a big separation or to a larger area by predictive models merely based on topographic variables. Follow-up studies will attempt to incorporate proxy indicators that can be extracted from hyperspectral images or LIDAR DEM and substitute for direct parameters to make predictive models applicable on a broader scale.

  10. Predicting habitat suitability for rare plants at local spatial scales using a species distribution model.

    PubMed

    Gogol-Prokurat, Melanie

    2011-01-01

    If species distribution models (SDMs) can rank habitat suitability at a local scale, they may be a valuable conservation planning tool for rare, patchily distributed species. This study assessed the ability of Maxent, an SDM reported to be appropriate for modeling rare species, to rank habitat suitability at a local scale for four edaphic endemic rare plants of gabbroic soils in El Dorado County, California, and examined the effects of grain size, spatial extent, and fine-grain environmental predictors on local-scale model accuracy. Models were developed using species occurrence data mapped on public lands and were evaluated using an independent data set of presence and absence locations on surrounding lands, mimicking a typical conservation-planning scenario that prioritizes potential habitat on unsurveyed lands surrounding known occurrences. Maxent produced models that were successful at discriminating between suitable and unsuitable habitat at the local scale for all four species, and predicted habitat suitability values were proportional to likelihood of occurrence or population abundance for three of four species. Unfortunately, models with the best discrimination (i.e., AUC) were not always the most useful for ranking habitat suitability. The use of independent test data showed metrics that were valuable for evaluating which variables and model choices (e.g., grain, extent) to use in guiding habitat prioritization for conservation of these species. A goodness-of-fit test was used to determine whether habitat suitability values ranked habitat suitability on a continuous scale. If they did not, a minimum acceptable error predicted area criterion was used to determine the threshold for classifying habitat as suitable or unsuitable. I found a trade-off between model extent and the use of fine-grain environmental variables: goodness of fit was improved at larger extents, and fine-grain environmental variables improved local-scale accuracy, but fine-grain variables

  11. Rare earth elements (REEs): effects on germination and growth of selected crop and native plant species.

    PubMed

    Thomas, Philippe J; Carpenter, David; Boutin, Céline; Allison, Jane E

    2014-02-01

    The phytotoxicity of rare earth elements (REEs) is still poorly understood. The exposure-response relationships of three native Canadian plant species (common milkweed, Asclepias syriaca L., showy ticktrefoil, Desmodium canadense (L.) DC. and switchgrass, Panicum virgatum L.) and two commonly used crop species (radish, Raphanus sativus L., and tomato, Solanum lycopersicum L.) to the REEs lanthanum (La), yttrium (Y) and cerium (Ce) were tested. In separate experiments, seven to eight doses of each element were added to the soil prior to sowing seeds. Effects of REE dose on germination were established through measures of total percent germination and speed of germination; effects on growth were established through determination of above ground biomass. Ce was also tested at two pH levels and plant tissue analysis was conducted on pooled samples. Effects on germination were mostly observed with Ce at low pH. However, effects on growth were more pronounced, with detectable inhibition concentrations causing 10% and 25% reductions in biomass for the two native forb species (A. syriaca and D. canadense) with all REEs and on all species tested with Ce in both soil pH treatments. Concentration of Ce in aboveground biomass was lower than root Ce content, and followed the dose-response trend. From values measured in natural soils around the world, our results continue to support the notion that REEs are of limited toxicity and not considered extremely hazardous to the environment. However, in areas where REE contamination is likely, the slow accumulation of these elements in the environment could become problematic. Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.

  12. Survey and assessment of the rare vascular plants of the Idaho National Engineering Laboratory Site

    SciTech Connect

    Cholewa, A.F.; Henderson, D.M.

    1984-01-31

    A two-year study of the rare vascular plants of the Idaho National Engineering Laboratory generated new data on the abundance, distribution, and habitat features of eight taxa presently under review at either the federal or state level, or recently proposed for such review. Astragalus ceramicus Sheld. var. apus Barneby is common on the INEL and adjacent areas and will be recommended for removal from further consideration at the federal level and placed on Idaho's Federal Watch List. Coryphanta missouriensis (Sweet) Britt and Rose is common throughout east central Idaho, but will be recommended for retainment on the State Watch List. Gymnosteris nudicaulis (H. and A.) Greene and Oxytheca dendroidea Nutt. are also recommended for retention on the State Watch List. Four taxa not previously known to occur in Idaho or not known from the southeastern part of the state (Astragalus gilviflorus Sheld., Astragalus kentrophyta Gray var. jessiae (Peck) Barneby, Gilia polycladon Torr., and Lesquerella kingii S. Watts. var. cobrensis Roll. and Shaw) were encountered and evaluated with reference to current or potential threats, and are recommended for placement on Idaho's State Watch List. 14 references, 1 figure.

  13. Genetic rescue persists beyond first-generation outbreeding in small populations of a rare plant.

    PubMed

    Willi, Yvonne; van Kleunen, Mark; Dietrich, Stefan; Fischer, Markus

    2007-09-22

    Habitat fragmentation commonly causes genetic problems and reduced fitness when populations become small. Stocking small populations with individuals from other populations may enrich genetic variation and alleviate inbreeding, but such artificial gene flow is not commonly used in conservation owing to potential outbreeding depression. We addressed the role of long-term population size, genetic distance between populations and test environment for the performance of two generations of offspring from between-population crosses of the locally rare plant Ranunculus reptans L. Interpopulation outbreeding positively affected an aggregate measure of fitness, and the fitness superiority of interpopulation hybrids was maintained in the second offspring (F2) generation. Small populations benefited more strongly from interpopulation outbreeding. Genetic distance between crossed populations in neutral markers or quantitative characters was not important. These results were consistent under near-natural competition-free and competitive conditions. We conclude that the benefits of interpopulation outbreeding are likely to outweigh potential drawbacks, especially for populations that suffer from inbreeding.

  14. Geographic profiling to assess the risk of rare plant poaching in natural areas

    USGS Publications Warehouse

    Young, J.A.; Van Manen, F.T.; Thatcher, C.A.

    2011-01-01

    We demonstrate the use of an expert-assisted spatial model to examine geographic factors influencing the poaching risk of a rare plant (American ginseng, Panax quinquefolius L.) in Shenandoah National Park, Virginia, USA. Following principles of the analytic hierarchy process (AHP), we identified a hierarchy of 11 geographic factors deemed important to poaching risk and requested law enforcement personnel of the National Park Service to rank those factors in a series of pair-wise comparisons. We used those comparisons to determine statistical weightings of each factor and combined them into a spatial model predicting poaching risk. We tested the model using 69 locations of previous poaching incidents recorded by law enforcement personnel. These locations occurred more frequently in areas predicted by the model to have a higher risk of poaching than random locations. The results of our study can be used to evaluate resource protection strategies and to target law enforcement activities. ?? Springer Science+Business Media, LLC (outside the USA) 2011.

  15. Seasonal timing of first rain storms affects rare plant population dynamics.

    PubMed

    Levine, Jonathan M; McEachern, A Kathryn; Cowan, Clark

    2011-12-01

    A major challenge in forecasting the ecological consequences of climate change is understanding the relative importance of changes to mean conditions vs. changes to discrete climatic events, such as storms, frosts, or droughts. Here we show that the first major storm of the growing season strongly influences the population dynamics of three rare and endangered annual plant species in a coastal California (USA) ecosystem. In a field experiment we used moisture barriers and water addition to manipulate the timing and temperature associated with first major rains of the season. The three focal species showed two- to fivefold variation in per capita population growth rates between the different storm treatments, comparable to variation found in a prior experiment imposing eightfold differences in season-long precipitation. Variation in germination was a major demographic driver of how two of three species responded to the first rains. For one of these species, the timing of the storm was the most critical determinant of its germination, while the other showed enhanced germination with colder storm temperatures. The role of temperature was further supported by laboratory trials showing enhanced germination in cooler treatments. Our work suggests that, because of species-specific cues for demographic transitions such as germination, changes to discrete climate events may be as, if not more, important than changes to season-long variables.

  16. Herbicides do not ensure for higher wheat yield, but eliminate rare plant species.

    PubMed

    Gaba, Sabrina; Gabriel, Edith; Chadœuf, Joël; Bonneu, Florent; Bretagnolle, Vincent

    2016-07-25

    Weed control is generally considered to be essential for crop production and herbicides have become the main method used for weed control in developed countries. However, concerns about harmful environmental consequences have led to strong pressure on farmers to reduce the use of herbicides. As food demand is forecast to increase by 50% over the next century, an in-depth quantitative analysis of crop yields, weeds and herbicides is required to balance economic and environmental issues. This study analysed the relationship between weeds, herbicides and winter wheat yields using data from 150 winter wheat fields in western France. A Bayesian hierarchical model was built to take account of farmers' behaviour, including implicitly their perception of weeds and weed control practices, on the effectiveness of treatment. No relationship was detected between crop yields and herbicide use. Herbicides were found to be more effective at controlling rare plant species than abundant weed species. These results suggest that reducing the use of herbicides by up to 50% could maintain crop production, a result confirmed by previous studies, while encouraging weed biodiversity. Food security and biodiversity conservation may, therefore, be achieved simultaneously in intensive agriculture simply by reducing the use of herbicides.

  17. Herbicides do not ensure for higher wheat yield, but eliminate rare plant species

    PubMed Central

    Gaba, Sabrina; Gabriel, Edith; Chadœuf, Joël; Bonneu, Florent; Bretagnolle, Vincent

    2016-01-01

    Weed control is generally considered to be essential for crop production and herbicides have become the main method used for weed control in developed countries. However, concerns about harmful environmental consequences have led to strong pressure on farmers to reduce the use of herbicides. As food demand is forecast to increase by 50% over the next century, an in-depth quantitative analysis of crop yields, weeds and herbicides is required to balance economic and environmental issues. This study analysed the relationship between weeds, herbicides and winter wheat yields using data from 150 winter wheat fields in western France. A Bayesian hierarchical model was built to take account of farmers’ behaviour, including implicitly their perception of weeds and weed control practices, on the effectiveness of treatment. No relationship was detected between crop yields and herbicide use. Herbicides were found to be more effective at controlling rare plant species than abundant weed species. These results suggest that reducing the use of herbicides by up to 50% could maintain crop production, a result confirmed by previous studies, while encouraging weed biodiversity. Food security and biodiversity conservation may, therefore, be achieved simultaneously in intensive agriculture simply by reducing the use of herbicides. PMID:27453451

  18. Effects of seed cryopreservation, stratification and scarification on germination for five rare species of pitcher plants.

    PubMed

    Khanna, Sruti; Jenkins, Heather; Bucalo, Kylie; Determann, Ron O; Cruse-Sanders, Jennifer M; Pullman, Gerald S

    2014-01-01

    Habitat loss and over collection have caused North American pitcher plants to become rare, including U.S. federally endangered Sarracenia alabamensis and S. oreophila, and S. leucophylla, S. psittacina and S. purpurea spp. venosa, endangered in several states. To develop reliable seed cryopreservation protocols for endangered Sarracenia species enabling similar germination percentages before and after storage in liquid nitrogen (LN) either in vivo or using in vitro tools. Seed germination pre- and post-cryopreservation were compared following seed drying with germination in soil, aseptic environment with wet filter paper or enriched medium, and using scarification or stratification for dormancy removal. After cryostorage, germination in vitro (1/6- or 1/3-strength MS medium) increased compared to germination on peat moss. Germination pre- and post-cryopreservation was similar for S. alabamensis and S. oreophila when seeds were stratified and grown in vitro. S. leucophylla and S. psittacina also showed high germination after cryopreservation when germinated on medium following stratification. Rapid liquid nitrogen exposure and rewarming induced seed coat cracking that damaged seeds, likely allowing internal damage during acid scarification and microbial entry during germination in non-sterile environments.

  19. Seasonal timing of first rain storms affects rare plant population dynamics

    USGS Publications Warehouse

    Levine, J.M.; McEachern, A.K.; Cowan, C.

    2011-01-01

    A major challenge in forecasting the ecological consequences of climate change is understanding the relative importance of changes to mean conditions vs. changes to discrete climatic events, such as storms, frosts, or droughts. Here we show that the first major storm of the growing season strongly influences the population dynamics of three rare and endangered annual plant species in a coastal California (USA) ecosystem. In a field experiment we used moisture barriers and water addition to manipulate the timing and temperature associated with first major rains of the season. The three focal species showed two- to fivefold variation in per capita population growth rates between the different storm treatments, comparable to variation found in a prior experiment imposing eightfold differences in season-long precipitation. Variation in germination was a major demographic driver of how two of three species responded to the first rains. For one of these species, the timing of the storm was the most critical determinant of its germination, while the other showed enhanced germination with colder storm temperatures. The role of temperature was further supported by laboratory trials showing enhanced germination in cooler treatments. Our work suggests that, because of species-specific cues for demographic transitions such as germination, changes to discrete climate events may be as, if not more, important than changes to season-long variables.

  20. Considerations for preserve design based on the distribution of rare plants in Great Smoky Mountains National Park, USA

    NASA Astrophysics Data System (ADS)

    Miller, Ronald I.; White, Peter S.

    1986-01-01

    Park design principles are proposed on the basis of consideration and analysis of rare plant species in Great Smoky Mountains National Park, USA. Rare species richness can be used as a simple measure of preservation success. A semilogartihmic species-area model for the Smokies was used in this analysis. Species richness would increase logarathmically with expansion of the national park area. An analysis of the relationship between species richness and the distribution of geologic and topographic features in the national park was also reported. An asymptotic relation was documented for the accumulation of newly recorded rare and endangered vascular plant species in the Smokies region up to 1978. Several multiple regression linear models predicted rare vascular plant species richness in Great Smoky Mountains National Park from area and topographic variates. Preserve design criteria can be based upon species-area, environmental gradient, and natural features distribution patterns for the specific taxa and biogeographic region under consideration. In addition, natural history characteristics for particular vulnerable species must be assessed. Rather than concentrating on the preservation of undocumented immigration and extinction processes, preserve design should be directed towards protecting geographic components and gradient patterns characteristic of a region.

  1. Impact of plant species, substrate types and porosity on the fractionation of rare-earth elements in plants

    NASA Astrophysics Data System (ADS)

    Semhi, K.; Clauer, N.; Chaudhuri, S.

    2009-04-01

    The distribution and content of rare-earth elements (REEs) were determined in two radish species (Raphanus sativus and Raphanus raphanistrum) that were grown under laboratory-controlled conditions, in three substrates consisting in illite for one and in smectite for the two others, the two latter being of the same type but with different porosities. The plants were split into two segments: the leaves and the stems+roots. The results indicate that both species pick up systematically higher amounts of REEs when grown in the illite substrate, considering that the smectite contains about 3 times more REEs. In R. sativus, the REE concentration of the leaves and of the stems+roots, whatever the substrate, ranges from 1.4 to 1.9 g/g. After normalization to the substrate in which they grew, the distribution patterns for the leaves of those from illite substrate are nearly flat, but irregular with a positive Eu anomaly. Those for the stems+roots are similar, but enriched in heavy REEs, also with a positive Eu anomaly. The REE concentrations of the leaves and the stems+roots of R. sativus grown in smectite are analytically similar at 1.6 and 1.4 g/g, respectively. The REE distribution patterns for the two organs, normalized again to those of the substrate, are very similar, flat with a distinct Eu anomaly. The heavy REE of the stems+roots of R. sativus grown on illite are enriched relative to those of the leaves, and a distinct positive Eu anomaly is observed in both the leaves and stems+roots from species grown on both illite and smectite. In the case of R. raphanistrum, the REE concentrations of the leaves and the stems+roots for those grown in the illite substrate were found to be significantly different at 11.0 and 6.6 g/g, respectively. The REE distribution patterns for the two different plant organs normalized to those of the substrates were found to be quite similar, all being quite flat, with a more or less pronounced Ce negative anomaly, and a prominent

  2. San Diego Multiple Species Conservation Program (MSCP) Rare Plant Monitoring Review and Revision

    USGS Publications Warehouse

    McEachern, Kathryn; Pavlik, Bruce M.; Rebman, Jon; Sutter, Rob

    2007-01-01

    Introduction The San Diego Multiple Species Conservation Program (MSCP) was developed for the conservation of plants and animals in the south part of San Diego County, under the California Natural Community Conservation Planning Act of 1991 (California Department of Fish and Game) and the Federal Endangered Species Act of 1973, as amended (16 U.S. Code 1531-1544.) The Program is on the leading edge of conservation, as it seeks to both guide development and conserve at-risk species with the oversight of both State and Federal agencies. Lands were identified for inclusion in the MSCP based on their value as habitat for at-risk plants or plant communities (Natural Community Conservation Planning, 2005). Since its inception in the mid-1990s the Program has protected over 100,000 acres, involving 15 jurisdictions and the U.S. Fish and Wildlife Service (USFWS) and California Department of Fish and Game (CDFG) in the conservation of 87 taxa. Surveys for covered species have been conducted, and management and monitoring have been implemented at some high priority sites. Each jurisdiction or agency manages and monitors their conservation areas independently, while collaborating regionally for long-term protection. The San Diego MSCP is on the forefront of conservation, in one of the most rapidly growing urban areas of the country. The planning effort that developed the MSCP was state-of-the-art, using expert knowledge, spatial habitat modeling, and principles of preserve design to identify and prioritize areas for protection. Land acquisition and protection are ahead of schedule for most jurisdictions. Surveys have verified the locations of many rare plant populations known from earlier collections, and they provide general information on population size and health useful for further conservation planning. Management plans have been written or are in development for most MSCP parcels under jurisdictional control. Several agencies are developing databases for implementation

  3. Vegetation Description, Rare Plant Inventory, and Vegetation Monitoring for Craig Mountain, Idaho.

    SciTech Connect

    Mancuso, Michael; Moseley, Robert

    1994-12-01

    The Craig Mountain Wildlife Mitigation Area was purchased by Bonneville Power Administration (BPA) as partial mitigation for wildlife losses incurred with the inundation of Dworshak Reservoir on the North Fork Clearwater River. Upon completion of the National Environmental Protection Act (NEPA) process, it is proposed that title to mitigation lands will be given to the Idaho Department of Fish and Game (IDFG). Craig Mountain is located at the northern end of the Hells Canyon Ecosystem. It encompasses the plateau and steep canyon slopes extending from the confluence of the Snake and Salmon rivers, northward to near Waha, south of Lewiston, Idaho. The forested summit of Craig Mountain is characterized by gently rolling terrain. The highlands dramatically break into the canyons of the Snake and Salmon rivers at approximately the 4,700 foot contour. The highly dissected canyons are dominated by grassland slopes containing a mosaic of shrubfield, riparian, and woodland habitats. During the 1993 and 1994 field seasons, wildlife, habitat/vegetation, timber, and other resources were systematically inventoried at Craig Mountain to provide Fish and Game managers with information needed to draft an ecologically-based management plan. The results of the habitat/vegetation portion of the inventory are contained in this report. The responsibilities for the Craig Mountain project included: (1) vegetation data collection, and vegetation classification, to help produce a GIS-generated Craig Mountain vegetation map, (2) to determine the distribution and abundance of rare plants populations and make recommendations concerning their management, and (3) to establish a vegetation monitoring program to evaluate the effects of Fish and Game management actions, and to assess progress towards meeting habitat mitigation goals.

  4. Using experiments and demographic models to assess rare plant vulnerability to utlity-scale solar energy development

    NASA Astrophysics Data System (ADS)

    Moore, K. A.

    2015-12-01

    Pressing challenges for the implementation of solar energy are the effects of construction and operation on protected animal and plant species. Siting and mitigation of solar energy often requires understanding of basic biology and distributions of rare species that are unknown. How can we rapidly collect the information necessary on species- and site-specific population dynamics to effectively design mitigation and conservation measures? We have developed an integrated approach to assessing the vulnerability of a suite of representative rare plant species in the region. We implemented a prioritized series of demographic and experimental studies over the past four years to identify the types of species, populations, and life stages most vulnerable to impact or prone to conservation efforts. We have found substantial variation in vegetative and sexual reproduction between study populations for several rare plants, including between populations that vary in putative impact by development and/or effects of experimental solar arrays. For a subset of species, we designed population viability analysis and applied them to identify sensitive vital rates and compare quasi-extinction probabilities under different climate and impact scenarios. By utilizing practical experiments to test for the effects of real or simulated impacts, we found differences in vital rates between natural and disturbed populations adjacent to and within solar installations. We draw conclusions from our work to guide the analysis of benefits, permitting, and design of utility-scale solar energy facilities.

  5. Anomalies in Trace Metal and Rare-Earth Loads below a Waste-Water Treatment Plant

    NASA Astrophysics Data System (ADS)

    Antweiler, R.; Writer, J. H.; Murphy, S.

    2013-12-01

    The changes in chemical loads were examined for 54 inorganic elements and compounds in a 5.4-km reach of Boulder Creek, Colorado downstream of a waste water treatment plant (WWTP) outfall. Elements were partitioned into three categories: those showing a decrease in loading downstream, those showing an increase, and those which were conservative, at least over the length of the study reach. Dissolved loads which declined - generally indicative of in-stream loss via precipitation or sorption - were typically rapid (occurring largely before the first sampling site, 2.3 km downstream); elements showing this behavior were Bi, Cr, Cs, Ga, Ge, Hg, Se and Sn. These results were as expected before the experiment was performed. However, a large group (28 elements, including all the rare-earth elements, REE, except Gd) exhibited dissolved load increases indicating in-stream gains. These gains may be due to particulate matter dissolving or disaggregating, or that desorption is occurring below the WWTP. As with the in-stream loss group, the processes tended to be rapid, typically occurring before the first sampling site. Whole-water samples collected concurrently also had a large group of elements which showed an increase in load downstream of the WWTP. Among these were most of the group which had increases in the dissolved load, including all the REE (except Gd). Because whole-water samples include both dissolved and suspended particulates within them, increases in loads cannot be accounted for by invoking desorption or disaggregation mechanisms; thus, the only source for these increases is from the bed load of the stream. Further, the difference between the whole-water and dissolved loads is a measure of the particulate load, and calculations show that not only did the dissolved and whole-water loads increase, but so did the particulate loads. This implies that at the time of sampling the bed sediment was supplying a significant contribution to the suspended load. In general

  6. A rare SNP mutation in Brachytic2 moderately reduces plant height and increases yield potential in maize

    PubMed Central

    Xing, Anqi; Gao, Yufeng; Ye, Lingfeng; Zhang, Weiping; Cai, Lichun; Ching, Ada; Llaca, Victor; Johnson, Blaine; Liu, Lin; Yang, Xiaohong; Kang, Dingming; Yan, Jianbing; Li, Jiansheng

    2015-01-01

    Plant height has long been an important agronomic trait in maize breeding. Many plant height QTLs have been reported, but few of these have been cloned. In this study, a major plant height QTL, qph1, was mapped to a 1.6kb interval in Brachytic2 (Br2) coding sequence on maize chromosome 1. A naturally occurring rare SNP in qph1, which resulted in an amino acid substitution, was validated as the causative mutation. QPH1 protein is located in the plasma membrane and polar auxin transport is impaired in the short near-isogenic line RIL88(qph1). Allelism testing showed that the SNP variant in qph1 reduces longitudinal cell number and decreases plant height by 20% in RIL88 (qph1) compared to RIL88 (QPH1), and is milder than known br2 mutant alleles. The effect of qph1 on plant height is significant and has no or a slight influence on yield in four F2 backgrounds and in six pairs of single-cross hybrids. Moreover, qph1 could reduce plant height when heterozygous, allowing it to be easily employed in maize breeding. Thus, a less-severe allele of a known dwarf mutant explains part of the quantitative variation for plant height and has great potential in maize improvement. PMID:25922491

  7. A rare SNP mutation in Brachytic2 moderately reduces plant height and increases yield potential in maize.

    PubMed

    Xing, Anqi; Gao, Yufeng; Ye, Lingfeng; Zhang, Weiping; Cai, Lichun; Ching, Ada; Llaca, Victor; Johnson, Blaine; Liu, Lin; Yang, Xiaohong; Kang, Dingming; Yan, Jianbing; Li, Jiansheng

    2015-07-01

    Plant height has long been an important agronomic trait in maize breeding. Many plant height QTLs have been reported, but few of these have been cloned. In this study, a major plant height QTL, qph1, was mapped to a 1.6kb interval in Brachytic2 (Br2) coding sequence on maize chromosome 1. A naturally occurring rare SNP in qph1, which resulted in an amino acid substitution, was validated as the causative mutation. QPH1 protein is located in the plasma membrane and polar auxin transport is impaired in the short near-isogenic line RIL88(qph1). Allelism testing showed that the SNP variant in qph1 reduces longitudinal cell number and decreases plant height by 20% in RIL88(qph1) compared to RIL88(QPH1), and is milder than known br2 mutant alleles. The effect of qph1 on plant height is significant and has no or a slight influence on yield in four F2 backgrounds and in six pairs of single-cross hybrids. Moreover, qph1 could reduce plant height when heterozygous, allowing it to be easily employed in maize breeding. Thus, a less-severe allele of a known dwarf mutant explains part of the quantitative variation for plant height and has great potential in maize improvement.

  8. Who’s eating the flowers of a rare western Nevada range plant?

    USDA-ARS?s Scientific Manuscript database

    Churchill Narrows buckwheat (Eriogonum diatomaceum) is an edaphic endemic plant that occurs only on diatomaceous soils on the northeastern flanks of the Pine Nut Mountains, Lyon Co., NV. The plant is listed by the State of Nevada as a sensitive species, and is on a priority list for listing under th...

  9. Limiting factors of four rare plant species in `Ōla`A Forest of Hawai'i Volcanoes National Park

    USGS Publications Warehouse

    VanDeMark, Joshua R.; Pratt, Linda W.; Euaparadorn, Melody

    2010-01-01

    In conclusion, 2 of the 3 regularly-monitored rare plant species of `Ōla`a Forest appeared to have more than 1 limiting factor inhibiting the natural increase in their populations, while for P. floribunda the most important factor was high seedling mortality. Most plants of the monitored C. giffardii population appeared to be hybrids, probably with the more common species C. lysiosepala. Seed germination rates were low, and natural seedlings were not observed. Pollinators were not seen in many hours of observation, indicating that cross pollination is a rare or uncommon event. The re-introduced population of P. floribunda had relatively low mortality, and reproduction was successful with high rates of fruit formation from abundant flowers. Seed germination rates were high, and a soil seed bank was detected. Natural seedling recruitment was observed, but high seedling mortality indicated that this life stage was the most vulnerable in the species. The population of S. alba was small and the vine life form precluded an accurate estimate of the number of adult plants in `Ōla`a Forest. Natural dormancy was likely a factor in the observed low rate of seed germination. No soil seed bank was detected, and alien rodents were implicated as seed predators. Natural recruitment was observed at multiple sites in `Ōla`a, but seedling mortality was high. The cause of seedling mortality was not identified.

  10. Transcriptomes of the parasitic plant family Orobanchaceae reveal surprising conservation of chlorophyll synthesis.

    PubMed

    Wickett, Norman J; Honaas, Loren A; Wafula, Eric K; Das, Malay; Huang, Kan; Wu, Biao; Landherr, Lena; Timko, Michael P; Yoder, John; Westwood, James H; dePamphilis, Claude W

    2011-12-20

    Parasitism in flowering plants has evolved at least 11 times [1]. Only one family, Orobanchaceae, comprises all major nutritional types of parasites: facultative, hemiparasitic (partially photosynthetic), and holoparasitic (nonphotosynthetic) [2]. Additionally, the family includes Lindenbergia, a nonparasitic genus sister to all parasitic Orobanchaceae [3-6]. Parasitic Orobanchaceae include species with severe economic impacts: Striga (witchweed), for example, affects over 50 million hectares of crops in sub-Saharan Africa, causing more than $3 billion in damage annually [7]. Although gene losses and increased substitution rates have been characterized for parasitic plant plastid genomes [5, 8-11], the nuclear genome and transcriptome remain largely unexplored. The Parasitic Plant Genome Project (PPGP; http://ppgp.huck.psu.edu/) [2] is leveraging the natural variation in Orobanchaceae to explore the evolution and genomic consequences of parasitism in plants through a massive transcriptome and gene discovery project involving Triphysaria versicolor (facultative hemiparasite), Striga hermonthica (obligate hemiparasite), and Phelipanche aegyptiaca (Orobanche [12]; holoparasite). Here we present the first set of large-scale genomic resources for parasitic plant comparative biology. Transcriptomes of above-ground tissues reveal that, in addition to the predictable loss of photosynthesis-related gene expression in P. aegyptiaca, the nonphotosynthetic parasite retains an intact, expressed, and selectively constrained chlorophyll synthesis pathway.

  11. Assessment of phylogenetic relationship of rare plant species collected from Saudi Arabia using internal transcribed spacer sequences of nuclear ribosomal DNA.

    PubMed

    Al-Qurainy, F; Khan, S; Nadeem, M; Tarroum, M; Alaklabi, A

    2013-03-11

    The rare and endangered plants of any country are important genetic resources that often require urgent conservation measures. Assessment of phylogenetic relationships and evaluation of genetic diversity is very important prior to implementation of conservation strategies for saving rare and endangered plant species. We used internal transcribed spacer sequences of nuclear ribosomal DNA for the evaluation of sequence identity from the available taxa in the GenBank database by using the Basic Local Alignment Search Tool (BLAST). Two rare plant species viz, Heliotropium strigosum claded with H. pilosum (98% branch support) and Pancratium tortuosum claded with P. tenuifolium (61% branch support) clearly. However, some species, viz Scadoxus multiflorus, Commiphora myrrha and Senecio hadiensis showed close relationships with more than one species. We conclude that nuclear ribosomal internal transcribed spacer sequences are useful markers for phylogenetic study of these rare plant species in Saudi Arabia.

  12. In vitro propagation and withaferin A production in Withania ashwagandha, a rare medicinal plant of India.

    PubMed

    Mir, Bilal Ahmad; Mir, Shabir Ahmad; Koul, Sushma

    2014-07-01

    Withania ashwagandha, belonging to the family Solanaceae, is an important medicinal herb of India with restricted geographic distribution. It is a rich source of withaferin A (WA) and other bioactive withanolides. In the present study a rapid in vitro mass propagation protocol of W. ashwagandha was developed from nodal explants. Nodal explants were cultured on MS medium supplemented with various concentrations and combinations of plant growth regulators (PGRs). The highest number of regenerated shoots per ex-plant (33 ± 2.7) and highest WA (13.4 ± 1.15 mg/g of DW) production was obtained on MS medium supplemented with 5.0 μM 6-benzyladenine (BA) and 1.0 μM Kinetin (Kn). In vitro raised shoots were further rooted on half-strength MS medium containing 2.0 μM Indole-3-butyric acid (IBA) and analyzed for WA production. The rooted plantlets when transferred to poly bags in the greenhouse showed 90 % survival frequency. Levels of WA were higher in the in vitro and ex vitro derived shoot and root tissues as compared to field grown mother plants. In an attempt to further maximize WA production, shoot cultures were further grown in liquid MS medium supplemented with 5.0 μM 6-benzyladenine (BA) and 1.0 μM Kinetin (Kn). Root cultures were grown on half strength MS liquid medium fortified with 2.0 μM of IBA. WA production in the liquid cultures was significantly higher compared to the static composition of the same media. This protocol, first of its kind in this plant, can be successfully employed for conservation, proliferation and large-scale production of WA. The regenerated plants can also be used in traditional medicine as an alternative to naturally collected plants.

  13. Portfolio effects, climate change, and the persistence of small populations: analyses on the rare plant Saussurea weberi.

    PubMed

    Abbott, Ronald E; Doak, Daniel F; Peterson, Megan L

    2017-01-23

    The mechanisms that stabilize small populations in the face of environmental variation are crucial to their long-term persistence. Building from diversity-stability concepts in community ecology, within-population diversity is gaining attention as an important component of population stability. Genetic and microhabitat variation within populations can generate diverse responses to common environmental fluctuations, dampening temporal variability across the population as a whole through portfolio effects. Yet, the potential for portfolio effects to operate at small scales within populations or to change with systematic environmental shifts, such as climate change, remain largely unexplored. We tracked the abundance of a rare alpine perennial plant, Saussurea weberi, in 49 1 m(2) plots within a single population over 20 years. We estimated among-plot correlations in log annual growth rate to test for population-level synchrony and quantify portfolio effects across the 20-year study period and also in 5-year subsets based on June temperature quartiles. Asynchrony among plots, due to different plot-level responses to June temperature, reduced overall fluctuations in abundance and the probability of decline in population models, even when accounting for the effects of density dependence on dynamics. However, plots became more synchronous and portfolio effects decreased during the warmest years of the study, suggesting that future climate warming may erode stabilizing mechanisms in populations of this rare plant. This article is protected by copyright. All rights reserved.

  14. Baseline survey for rare plant species and native plant communities within the Kamehameha Schools 'Lupea Safe Harbor Planning Project Area, North Kona District, Island of Hawai'i

    USGS Publications Warehouse

    Jacobi, James; F. R. Warshauer, frwvolcano@hotmail.com; Jonathan Price, jpprice@hawaii.edu

    2010-01-01

    Non-zero baseline values are proposed for the one listed plant species found within the Lupea Project area, one species that is a candidate for listing, and the four other rare species we found that may be considered for listing in the future. Additionally, a zero baseline is proposed for 23 other species that were predicted, but not found within the project area. These include 14 Endangered species, one Threatened species, two candidates for listing, and six species of concern. Subsequent monitoring of the site will be necessary to determine if the populations of these species have increased or decreased relative to their baseline values. It is presumed that the management activities Kamehameha Schools has proposed for this area, particularly removal of the ungulates and weed control, will provide a benefit to the habitat as a whole and allow for natural regeneration and maintenance of the all elements of the plant communities found there.

  15. Limited mate availability decreases reproductive success of fragmented populations of Linnaea borealis, a rare, clonal self-incompatible plant

    PubMed Central

    Scobie, A. R.; Wilcock, C. C.

    2009-01-01

    Background and Aims Small populations of rare plant species are increasingly reported to have high levels of reproductive failure. The objective of this study was to understand the principal constraints on sexual reproduction in small fragmented populations of a rare clonal self-incompatible plant. Methods The pollinator spectrum, diversity of flower colour, natural pollination and fruit-set levels of L. borealis were examined in Scotland. Artificially crossed seed production was compared within and between different flower colour types and patches. Key Results Linnaea borealis was pollinated by a diverse spectrum of insect species and the principal pollinators were muscid, syrphid and empid flies which mostly moved only small distances (<0·25 m) between flowers when foraging. Natural pollination levels were high, indicating high pollinator effectiveness, but fruit set was very low in most patches. Flower colour diversity was low in most patches and only those with a diversity of flower colour types had high fruiting success. Pollination experiments showed L. borealis to be highly self-incompatible and artificial crosses within and between patches and flower colour types confirmed that low fruit success was the result of a lack of compatible mates and limited pollen movement between them. Evidence of isolation from pollen exchange was apparent at as little as 6 m and severe at 30 m and beyond. Conclusions Limited mate availability and isolation from pollen exchange compromise the reproductive success of fragmented populations of L. borealis in Scotland. A diversity of compatible mates situated within close proximity (<6 m) is the key requirement to ensure high natural fruiting success. This study emphasizes that an understanding of the breeding system, pollinator spectrum and potential for interconnectivity via pollinator movement are fundamental to identify isolation distances and to establish when conservation intervention is necessary for rare species. PMID

  16. Limited mate availability decreases reproductive success of fragmented populations of Linnaea borealis, a rare, clonal self-incompatible plant.

    PubMed

    Scobie, A R; Wilcock, C C

    2009-04-01

    Small populations of rare plant species are increasingly reported to have high levels of reproductive failure. The objective of this study was to understand the principal constraints on sexual reproduction in small fragmented populations of a rare clonal self-incompatible plant. The pollinator spectrum, diversity of flower colour, natural pollination and fruit-set levels of L. borealis were examined in Scotland. Artificially crossed seed production was compared within and between different flower colour types and patches. Linnaea borealis was pollinated by a diverse spectrum of insect species and the principal pollinators were muscid, syrphid and empid flies which mostly moved only small distances (<0.25 m) between flowers when foraging. Natural pollination levels were high, indicating high pollinator effectiveness, but fruit set was very low in most patches. Flower colour diversity was low in most patches and only those with a diversity of flower colour types had high fruiting success. Pollination experiments showed L. borealis to be highly self-incompatible and artificial crosses within and between patches and flower colour types confirmed that low fruit success was the result of a lack of compatible mates and limited pollen movement between them. Evidence of isolation from pollen exchange was apparent at as little as 6 m and severe at 30 m and beyond. Limited mate availability and isolation from pollen exchange compromise the reproductive success of fragmented populations of L. borealis in Scotland. A diversity of compatible mates situated within close proximity (<6 m) is the key requirement to ensure high natural fruiting success. This study emphasizes that an understanding of the breeding system, pollinator spectrum and potential for interconnectivity via pollinator movement are fundamental to identify isolation distances and to establish when conservation intervention is necessary for rare species.

  17. A comparison of the herbicide tolerances of rare and common plants in an agricultural landscape

    USDA-ARS?s Scientific Manuscript database

    Declining plant biodiversity in agroecosystems has often been attributed to escalating use of chemical herbicides, but other changes in farming practice including the clearing of semi-natural habitat fragments confound the influence of herbicides. In this paper, we introduce a new approach to evalua...

  18. Rare & Endangered Species: Understanding Our Disappearing Plants and Animals. Activities Guide.

    ERIC Educational Resources Information Center

    American Gas Association, Arlington, VA. Educational Services.

    About 464 plants and animals found in the United States and its territories are listed by the U.S. Fish and Wildlife Service as threatened or endangered. Another 3900 are candidates for protection. The activities in this guide are designed to help teachers and students understand the issue of endangered species. It includes ideas for several…

  19. Insect Pollinators of Three Rare Plants in a Florida Longleaf Pine Forest

    Treesearch

    Theresa Pitts-Singer; James L. Hanula; Joan L. Walker

    2002-01-01

    As a result of human activity, longleaf pine (Pinus palustris Miller) forests in the southern United States have been lost or drastically altered. Many of the plant species that historically occupied those forests now persist only as remnants and are classified as threatened or endangered. In order to safeguard such species, a better understanding of...

  20. Rare & Endangered Species: Understanding Our Disappearing Plants and Animals. Activities Guide.

    ERIC Educational Resources Information Center

    American Gas Association, Arlington, VA. Educational Services.

    About 464 plants and animals found in the United States and its territories are listed by the U.S. Fish and Wildlife Service as threatened or endangered. Another 3900 are candidates for protection. The activities in this guide are designed to help teachers and students understand the issue of endangered species. It includes ideas for several…

  1. Using a network modularity analysis to inform management of a rare endemic plant in the northern Great Plains, USA

    USGS Publications Warehouse

    Larson, Diane L.; Droege, Sam; Rabie, Paul A.; Larson, Jennifer L.; Devalez, Jelle; Haar, Milton; McDermott-Kubeczko, Margaret

    2014-01-01

    1. Analyses of flower-visitor interaction networks allow application of community-level information to conservation problems, but management recommendations that ensue from such analyses are not well characterized. Results of modularity analyses, which detect groups of species (modules) that interact more with each other than with species outside their module, may be particularly applicable to management concerns. 2. We conducted modularity analyses of networks surrounding a rare endemic annual plant, Eriogonum visheri, at Badlands National Park, USA, in 2010 and 2011. Plant species visited were determined by pollen on insect bodies and by flower species upon which insects were captured. Roles within modules (network hub, module hub, connector and peripheral, in decreasing order of network structural importance) were determined for each species. 3. Relationships demonstrated by the modularity analysis, in concert with knowledge of pollen species carried by insects, allowed us to infer effects of two invasive species on E. visheri. Sharing a module increased risk of interspecific pollen transfer to E. visheri. Control of invasive Salsola tragus, which shared a module with E. visheri, is therefore a prudent management objective, but lack of control of invasive Melilotus officinalis, which occupied a different module, is unlikely to negatively affect pollination of E. visheri. Eriogonum pauciflorum may occupy a key position in this network, supporting insects from the E. visheri module when E. visheri is less abundant. 4. Year-to-year variation in species' roles suggests management decisions must be based on observations over several years. Information on pollen deposition on stigmas would greatly strengthen inferences made from the modularity analysis. 5. Synthesis and applications: Assessing the consequences of pollination, whether at the community or individual level, is inherently time-consuming. A trade-off exists: rather than an estimate of fitness effects, the

  2. Conservation value of sites of hybridization in peripheral populations of rare plant species.

    PubMed

    Thompson, John D; Gaudeul, Myriam; Debussche, Max

    2010-02-01

    Populations at the periphery of a species' range are of interest to conservation biologists because they can show marked genetic differentiation from populations at the center of a range and because of potential hybridization among rare and common species. We examined two closely related Cyclamen species. One is a narrow endemic, and the other is more geographically widespread (both protected by law in continental southern France). We used floral traits and genetic variability to test for hybridization among the species in peripheral populations of the rare species. The species co-occurred on Corsica in a disjunct, peripheral part of the distribution of the endemic species and in an ecologically marginal area for the widespread species. The two species have hybridized and the endemic species showed high levels of introgression with its widespread congener. Genetic and floral variability in sites with both species was markedly higher than in sites with a single species. Our results highlight the need for a conservation strategy that integrates hybrid populations because they represent a source of novel diversity that may have adaptive potential.

  3. Identification and Management of Multiple Threats to Rare and Endangered Plant Species

    DTIC Science & Technology

    2013-07-30

    Proportion of A. rostellata (A), A. serpentaria (B) and T. erectum (C) plants attacked by herbivores in one open and fenced plot per species from 2009...by the angular cut of stems. These three species also showed frequent attack by a variety of invertebrate herbivores . Population growth rate (λ) of... herbivores . These effects are most likely species-specific as has been demonstrated in Minnesota where foliar nitrogen content for Carex pensylvanica

  4. Biological assessment for rare and endangered plant species: Related to CERCLA characterization activities

    SciTech Connect

    Sackschewsky, M.R.

    1992-04-01

    Environmental characterization in support of hazardous, radioactive, and mixed waste cleanup (in accordance with the Comprehensive Environmental Response, Compensation, and Liability Act of 1980) can involve a large number of both nonintrusive and intrusive activities. Many of these activities could have a detrimental impact on listed plant species. These impacts can be minimized by following simple conservation policies while conducting the various field activities. For instance, frequent off-road vehicular traffic and have a severe impact on native habitats and, therefore, should be kept to a minimum. Personnel performing the field activities should be trained to preserve, respect, and minimize their impact on native habitat while performing work in the field. In addition, areas where sampling is planned should be surveyed for the presence of listed plant species before the initiation of the field activities. Extremely distributed areas could be exempted from this requirement provided adequate habitat assessments have been performed by qualified personnel. Twelve special status plant species are known to survive on or very near the Hanford Site. None of these species currently are listed as Federal Threatened or Endangered Species. However, four local species currently are candidates for federal protection. These species are the Northern Wormwood (Artemisia campestris ssp. borealis var. wormskioldii), Persistantsepal Yellowcress (Rorippa columbiae), Hoover's Desert Parsley (Lomatium tuberosum), and Columbia Milkvetch (Astragalus columbianus).

  5. Biological assessment for rare and endangered plant species: Related to CERCLA characterization activities

    SciTech Connect

    Sackschewsky, M.R.

    1992-04-01

    Environmental characterization in support of hazardous, radioactive, and mixed waste cleanup (in accordance with the Comprehensive Environmental Response, Compensation, and Liability Act of 1980) can involve a large number of both nonintrusive and intrusive activities. Many of these activities could have a detrimental impact on listed plant species. These impacts can be minimized by following simple conservation policies while conducting the various field activities. For instance, frequent off-road vehicular traffic and have a severe impact on native habitats and, therefore, should be kept to a minimum. Personnel performing the field activities should be trained to preserve, respect, and minimize their impact on native habitat while performing work in the field. In addition, areas where sampling is planned should be surveyed for the presence of listed plant species before the initiation of the field activities. Extremely distributed areas could be exempted from this requirement provided adequate habitat assessments have been performed by qualified personnel. Twelve special status plant species are known to survive on or very near the Hanford Site. None of these species currently are listed as Federal Threatened or Endangered Species. However, four local species currently are candidates for federal protection. These species are the Northern Wormwood (Artemisia campestris ssp. borealis var. wormskioldii), Persistantsepal Yellowcress (Rorippa columbiae), Hoover`s Desert Parsley (Lomatium tuberosum), and Columbia Milkvetch (Astragalus columbianus).

  6. Apoptosis-inducing effects of distichamine and narciprimine, rare alkaloids of the plant family Amaryllidaceae.

    PubMed

    Nair, Jerald J; Rárová, Lucie; Strnad, Miroslav; Bastida, Jaume; van Staden, Johannes

    2012-10-01

    Several of the Amaryllidaceae alkaloids are known for their cytotoxic properties, of which the lycorine group representatives are prominent for potent and cell line specific antiproliferative activities. As a distinct niche within the lycorine group, the phenanthridones, exemplified by narciclasine and pancratistatin, have shown much promise as remarkably selective cytotoxic agents and are presently at various stages of development, with a clinical candidate likely to appear on the market within the next decade. The crinane group of the Amaryllidaceae has also spawned several molecules, such as crinamine and haemanthamine, with promising cytotoxic activities. In the present study, the β-crinane distichamine as well as the phenanthridone narciprimine, both rare constituents of the Amaryllidaceae, are revealed as novel antiproliferative agents. Apoptosis-inducing effects are demonstrated for distichamine in human acute lymphoblastic leukemia (CEM) cells. These findings provide further insights to the structural details of the apoptosis-inducing pharmacophores resident within both series of alkaloids.

  7. Remedial actions at the former Vitro Rare Metals plant site, Canonsburg, Washington County, Pennsylvania. Final Environmental Impact Statement. Volume I

    SciTech Connect

    Not Available

    1983-07-01

    The environmental impacts associated with remedial actions in connection with residual radioactive materials remaining at the inactive uranium processing site located in Canonsburg, Washington County, Pennsylvania are evaluated. The Canonsburg site is an 18.5-acre property that was formerly owned by the Vitro Rare Metals Company. The expanded Canonsburg site would be 30-acre property that would include the Canonsburg site (the former Vitro Rare Metals plant), seven adjacent private houses, and the former Georges Pottery property. During the period 1942 through 1957 the Vitro Manufacturing Company and its successor, the Vitro Corporation of America, processed onsite residues and ores, and government-owned ores, concentrates, and scraps to extract uranium and other rare metals. The Canonsburg site is now the Canon Industrial Park. In addition to storing the residual radioactive materials of this process at the Canonsburg site, about 12,000 tons of radioactively contaminated materials were transferred to a railroad landfill in Burrell Township, Indiana County, Pennsylvania. This Canonsburg FEIS evaluates five alternatives for removing the potential public health hazard associated with the radioactively contaminated materials. In addition to no action, these alternatives involve various combinations of stabilization of the radioactively contaminated materials in place or decontamination of the Canonsburg and Burrell sites by removing the radioactively contaminated materials to another location. In addition to the two sites mentioned, a third site located in Hanover Township, Washington County, Pennsylvania has been considered as a disposal site to which the radioactively contaminated materials presently located at either of the other two sites might be moved.

  8. Lawrence Livermore National Laboratory Pre-project Rare Plant and Wildlife Surveys For the Pit 7 Drainage Diversion and Groundwater Extraction and Treatment Facility

    SciTech Connect

    Paterson, L; Woollett, J

    2007-07-17

    In January 2007, the Department of Energy (DOE) released the final Environmental Assessment for the Proposed Environmental Remediation at the Lawrence Livermore National Laboratory (LLNL) Site 300 Pit 7 Complex. At the same time, the Department of Toxic Substances Control (DTSC) released the final Negative Declaration and Initial Study covering the Pit 7 remediation. No substantial adverse effect on wildlife species of concern was anticipated from the project. However, it was proposed that wildlife surveys should be conducted prior to construction because species locations and breeding areas could potentially change by the time construction activities began. Although no known populations of rare or endangered/threatened plant species were known to occur within the project impact area at the time these documents were released, rare plants listed by the California Native Plant Society had been observed in the vicinity. As such, both DOE and DTSC proposed that plant surveys would be undertaken at the appropriate time of year to determine if rare plants would be impacted by project construction. This document provides the results of wildlife and rare plant surveys taken prior to the start of construction at the Pit 7 Complex.

  9. Field Surveys of Rare Plants on Santa Cruz Island, California, 2003-2006: Historical Records and Current Distributions

    USGS Publications Warehouse

    McEachern, A. Kathryn; Chess, Katherine A.; Niessen, Ken

    2010-01-01

    Santa Cruz Island is the largest of the northern Channel Islands located off the coast of California. It is owned and managed as a conservation reserve by The Nature Conservancy and the Channel Islands National Park. The island is home to nine plant taxa listed in 1997 as threatened or endangered under the federal Endangered Species Act, because of declines related to nearly 150 years of ranching on the island. Feral livestock were removed from the island as a major conservation step, which was part of a program completed in early 2007 with the eradication of pigs and turkeys. For the first time in more than a century, the rare plants of Santa Cruz Island have a chance to recover in the wild. This study provides survey information and living plant materials needed for recovery management of the listed taxa. We developed a database containing information about historical collections of the nine taxa and used it to plan a survey strategy. Our objectives were to relocate as many of the previously known populations as possible, with emphasis on documenting sites not visited in several decades, sites that were poorly documented in the historical record, and sites spanning the range of environmental conditions inhabited by the taxa. From 2003 through 2006, we searched for and found 39 populations of the taxa, indicating that nearly 80 percent of the populations known earlier in the 1900s still existed. Most populations are small and isolated, occupying native-dominated habitat patches in a highly fragmented and invaded landscape; they are still at risk of declining through population losses. Most are not expanding beyond the edges of their habitat patches. However, most taxa appeared to have good seed production and a range of size classes in populations, indicating a good capacity for plant recruitment and population growth in these restricted sites. For these taxa, seed collection and outplanting might be a good strategy to increase numbers of populations for species

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

    PubMed Central

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

    2016-01-01

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

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

    PubMed

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

    2016-01-01

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

  12. Occurrence of morphological and anatomical adaptive traits in young and adult plants of the rare Mediterranean cliff species Primula palinuri Petagna.

    PubMed

    De Micco, Veronica; Aronne, Giovanna

    2012-01-01

    Cliffs worldwide are known to be reservoirs of relict biodiversity. Despite the presence of harsh abiotic conditions, large endemic floras live in such environments. Primula palinuri Petagna is a rare endemic plant species, surviving on cliff sites along a few kilometres of the Tyrrhenian coast in southern Italy. This species is declared at risk of extinction due to human impact on the coastal areas in question. Population surveys have shown that most of the plants are old individuals, while seedlings and plants at early stages of development are rare. We followed the growth of P. palinuri plants from seed germination to the adult phase and analysed the morphoanatomical traits of plants at all stages of development. Our results showed that the pressure of cliff environmental factors has been selected for seasonal habitus and structural adaptive traits in this species. The main morphoanatomical modifications are suberized cell layers and accumulation of phenolic compounds in cell structures. These features are strictly related to regulation of water uptake and storage as well as defence from predation. However, we found them well established only in adult plants and not in juvenile individuals. These findings contribute to explain the rare recruitment of the present relict populations, identifying some of the biological traits which result in species vulnerability.

  13. Occurrence of Morphological and Anatomical Adaptive Traits in Young and Adult Plants of the Rare Mediterranean Cliff Species Primula palinuri Petagna

    PubMed Central

    De Micco, Veronica; Aronne, Giovanna

    2012-01-01

    Cliffs worldwide are known to be reservoirs of relict biodiversity. Despite the presence of harsh abiotic conditions, large endemic floras live in such environments. Primula palinuri Petagna is a rare endemic plant species, surviving on cliff sites along a few kilometres of the Tyrrhenian coast in southern Italy. This species is declared at risk of extinction due to human impact on the coastal areas in question. Population surveys have shown that most of the plants are old individuals, while seedlings and plants at early stages of development are rare. We followed the growth of P. palinuri plants from seed germination to the adult phase and analysed the morphoanatomical traits of plants at all stages of development. Our results showed that the pressure of cliff environmental factors has been selected for seasonal habitus and structural adaptive traits in this species. The main morphoanatomical modifications are suberized cell layers and accumulation of phenolic compounds in cell structures. These features are strictly related to regulation of water uptake and storage as well as defence from predation. However, we found them well established only in adult plants and not in juvenile individuals. These findings contribute to explain the rare recruitment of the present relict populations, identifying some of the biological traits which result in species vulnerability. PMID:22666127

  14. [Rare earth elements content in farmland soils and crops of the surrounding copper mining and smelting plant in Jiangxi province and evaluation of its ecological risk].

    PubMed

    Jin, Shu-Lan; Huang, Yi-Zong; Wang, Fei; Xu, Feng; Wang, Xiao-Ling; Gao, Zhu; Hu, Ying; Qiao Min; Li, Jin; Xiang, Meng

    2015-03-01

    Rare earth elements content in farmland soils and crops of the surrounding copper mining and smelting plant in Jiangxi province was studied. The results showed that copper mining and smelting could increase the content of rare earth elements in soils and crops. Rare earth elements content in farmland soils of the surrounding Yinshan Lead Zinc Copper Mine and Guixi Smelting Plant varied from 112.42 to 397.02 mg x kg(-1) and 48.81 to 250.06 mg x kg(-1), and the average content was 254.84 mg x kg(-1) and 144.21 mg x kg(-1), respectively. The average contents of rare earth elements in soils in these two areas were 1.21 times and 0.68 times of the background value in Jiangxi province, 1.36 times and 0.77 times of the domestic background value, 3.59 times and 2.03 times of the control samples, respectively. Rare earth elements content in 10 crops of the surrounding Guixi Smelting Plant varied from 0.35 to 2.87 mg x kg(-1). The contents of rare earth elements in the leaves of crops were higher than those in stem and root. The contents of rare earth elements in Tomato, lettuce leaves and radish leaves were respectively 2.87 mg x kg(-1), 1.58 mg x kg(-1) and 0.80 mg x kg(-1), which were well above the hygienic standard limit of rare earth elements in vegetables and fruits (0.70 mg x kg(-1)). According to the health risk assessment method recommended by America Environmental Protection Bureau (USEPA), we found that the residents' lifelong average daily intake of rare earth elements was 17.72 mg x (kg x d)(-1), lower than the critical value of rare earth elements damage to human health. The results suggested that people must pay attention to the impact of rare earth elements on the surrounding environment when they mine and smelt copper ore in Jiangxi.

  15. Rare allele of a previously unidentified histone H4 acetyltransferase enhances grain weight, yield, and plant biomass in rice.

    PubMed

    Song, Xian Jun; Kuroha, Takeshi; Ayano, Madoka; Furuta, Tomoyuki; Nagai, Keisuke; Komeda, Norio; Segami, Shuhei; Miura, Kotaro; Ogawa, Daisuke; Kamura, Takumi; Suzuki, Takamasa; Higashiyama, Tetsuya; Yamasaki, Masanori; Mori, Hitoshi; Inukai, Yoshiaki; Wu, Jianzhong; Kitano, Hidemi; Sakakibara, Hitoshi; Jacobsen, Steven E; Ashikari, Motoyuki

    2015-01-06

    Grain weight is an important crop yield component; however, its underlying regulatory mechanisms are largely unknown. Here, we identify a grain-weight quantitative trait locus (QTL) encoding a new-type GNAT-like protein that harbors intrinsic histone acetyltransferase activity (OsglHAT1). Our genetic and molecular evidences pinpointed the QTL-OsglHAT1's allelic variations to a 1.2-kb region upstream of the gene body, which is consistent with its function as a positive regulator of the traits. Elevated OsglHAT1 expression enhances grain weight and yield by enlarging spikelet hulls via increasing cell number and accelerating grain filling, and increases global acetylation levels of histone H4. OsglHAT1 localizes to the nucleus, where it likely functions through the regulation of transcription. Despite its positive agronomical effects on grain weight, yield, and plant biomass, the rare allele elevating OsglHAT1 expression has so far escaped human selection. Our findings reveal the first example, to our knowledge, of a QTL for a yield component trait being due to a chromatin modifier that has the potential to improve crop high-yield breeding.

  16. Rare allele of a previously unidentified histone H4 acetyltransferase enhances grain weight, yield, and plant biomass in rice

    PubMed Central

    Song, Xian Jun; Kuroha, Takeshi; Ayano, Madoka; Furuta, Tomoyuki; Nagai, Keisuke; Komeda, Norio; Segami, Shuhei; Miura, Kotaro; Ogawa, Daisuke; Kamura, Takumi; Suzuki, Takamasa; Higashiyama, Tetsuya; Yamasaki, Masanori; Mori, Hitoshi; Inukai, Yoshiaki; Wu, Jianzhong; Kitano, Hidemi; Sakakibara, Hitoshi; Jacobsen, Steven E.; Ashikari, Motoyuki

    2015-01-01

    Grain weight is an important crop yield component; however, its underlying regulatory mechanisms are largely unknown. Here, we identify a grain-weight quantitative trait locus (QTL) encoding a new-type GNAT-like protein that harbors intrinsic histone acetyltransferase activity (OsglHAT1). Our genetic and molecular evidences pinpointed the QTL-OsglHAT1’s allelic variations to a 1.2-kb region upstream of the gene body, which is consistent with its function as a positive regulator of the traits. Elevated OsglHAT1 expression enhances grain weight and yield by enlarging spikelet hulls via increasing cell number and accelerating grain filling, and increases global acetylation levels of histone H4. OsglHAT1 localizes to the nucleus, where it likely functions through the regulation of transcription. Despite its positive agronomical effects on grain weight, yield, and plant biomass, the rare allele elevating OsglHAT1 expression has so far escaped human selection. Our findings reveal the first example, to our knowledge, of a QTL for a yield component trait being due to a chromatin modifier that has the potential to improve crop high-yield breeding. PMID:25535376

  17. Rare Species (RS)

    Treesearch

    Steve Sutherland

    2006-01-01

    The FIREMON Rare Species (RS) method is used to assess changes in uncommon, perennial plant species when other monitoring methods are not effective. This method monitors individual plants and statistically quantifies changes in plant survivorship, growth, and reproduction over time. Plants are spatially located using distance along and from a permanent baseline, and...

  18. Population size and identity influence the reaction norm of the rare, endemic plant Cochlearia bavarica across a gradient of environmental stress.

    PubMed

    Paschke, Melanie; Bernasconi, Giorgina; Schmid, Bernhard

    2003-03-01

    Habitat degradation and loss can result in population decline and genetic erosion, limiting the ability of organisms to cope with environmental change, whether this is through evolutionary genetic response (requiring genetic variation) or through phenotypic plasticity (i.e., the ability of a given genotype to express a variable phenotype across environments). Here we address the question whether plants from small populations are less plastic or more susceptible to environmental stress than plants from large populations. We collected seed families from small (<100) versus large natural populations (>1,000 flowering plants) of the rare, endemic plant Cochlearia bavarica (Brassicaceae). We exposed the seedlings to a range of environments, created by manipulating water supply and light intensity in a 2 x 2 factorial design in the greenhouse. We monitored plant growth and survival for 300 days. Significant effects of offspring environment on offspring characters demonstrated that there is phenotypic plasticity in the responses to environmental stress in this species. Significant effects of population size group, but mainly of population identity within the population size groups, and of maternal plant identity within populations indicated variation due to genetic (plus potentially maternal) variation for offspring traits. The environment x maternal plant identity interaction was rarely significant, providing little evidence for genetically- (plus potentially maternally-) based variation in plasticity within populations. However, significant environment x population-size-group and environment x population-identity interactions suggested that populations differed in the amount of plasticity, the mean amount being smaller in small populations than in large populations. Whereas on day 210 the differences between small and large populations were largest in the environment in which plants grew biggest (i.e., under benign conditions), on day 270 the difference was largest in

  19. Transfer of rare earth elements from natural metalliferous (copper and cobalt rich) soils into plant shoot biomass of metallophytes from Katanga (Democratic Republic of Congo)

    NASA Astrophysics Data System (ADS)

    Pourret, Olivier; Lange, Bastien; Jitaru, Petru; Mahy, Grégory; Faucon, Michel-Pierre

    2014-05-01

    The geochemical behavior of rare earth elements (REE) is generally assessed for the characterization of the geological systems where these elements represent the best proxies of processes involving the occurrence of an interface between different media. REE behavior is investigated according to their concentrations normalized with respect to the upper continental crust. In this study, the geochemical fingerprint of REE in plant shoot biomass of an unique metallicolous flora (i.e., Crepidorhopalon tenuis and Anisopappus chinensis) was investigated. The plants originate from extremely copper and cobalt rich soils, deriving from Cu and Co outcrops in Katanga, Democratic Republic of Congo. Some of the species investigated in this study are able to accumulate high amounts of Cu and Co in shoot hence being considered as Cu and Co hyperaccumulators. Therefore, assessing the behavior of REE may lead to a better understanding of the mechanisms of metal accumulation by this flora. The data obtained in this study indicate that REE uptake by plants is not primarily controlled by their concentration and speciation in the soil as previously shown in the literature (Brioschi et al. 2013). Indeed, the REE patterns in shoots are relatively flat whereas soils patterns are Middle REE enriched. In addition, it is worth noting that Eu enrichments occur in aerial parts of the plants. These positive Eu anomalies suggest that Eu3 + can form stable organic complexes replacing Ca2 + in several biological processes as in xylem fluids associated with the general nutrient flux. Therefore, is is possible that the Eu mobility in these fluids is enhanced by its reductive speciation as Eu2 +. Eventually, the geochemical behavior of REE illustrates that metals accumulation in aerial parts of C. tenuis and A. chinensis is mainly driven by dissolved complexation. Brioschi, L., Steinmann, M., Lucot, E., Pierret, M., Stille, P., Prunier, J., Badot, P., 2013. Transfer of rare earth elements (REE) from

  20. An Inventory of Rare and Endangered Plant Species Found in the St. Louis, Missouri, Corps of Engineers District.

    DTIC Science & Technology

    1976-06-01

    8217n no Icand (Al eventh o t s p ec 1o un 113 incni o ccur w! t Porn t ho bunodari Co i:h s;{ Lou Ls v! s C c c L-In thle Stv. Loo 1) Dis tI-i c C1 ;t...it. compe t it 1 , d i sea . A(I cjd apCrod Rare. A rare spc cci" or subspr

  1. Childhood leukemia near nuclear plants in the United Kingdom: The evolution of a systematic approach to studying rare disease in small geographic areas

    SciTech Connect

    Beral, V. )

    1990-07-01

    A cluster of childhood leukemia in a village near a nuclear plant in northern England prompted further studies of cancer in the vicinity of other nuclear plants in the United Kingdom. These studies demonstrated that the risk of childhood leukemia was increased near certain other nuclear plants. Although the reasons for the increase are still unclear, the scientific debate stimulated by these findings has clarified some of the special methodological problems encountered when studying rare diseases in small areas. Firstly, unless a specific hypothesis is defined in advance, the relevance of a single geographic cluster of disease can rarely be interpreted. Even when a prior hypothesis exists, the small number of cases which generally occur in a small area make the findings highly sensitive to reporting, diagnostic, or classification errors. The statistical power of such investigations is also usually low and only marked increases in risk can be detected. Furthermore, conventional statistical tests may be inappropriate if the underlying spatial distribution of the disease is not random; and little is known about the background distribution of disease in small areas. Investigations of specific hypotheses about defined sources of environmental contamination, especially if they can be replicated, are more likely to result in conclusive findings that are in-depth studies of individual clusters.

  2. Genetic structure and AFLP variation of remnant populations in the rare plant Pedicularis palustris (Scrophulariaceae) and its relation to population size and reproductive components.

    PubMed

    Schmidt, K; Jensen, K

    2000-05-01

    We investigated plant reproduction in relation to genetic structure, population size, and habitat quality in 13 populations of the rare biennial plant Pedicularis palustris with 3-28500 flowering individuals. We used AFLP (amplified fragment length polymorphism) profiles to analyze genetic similarities among 129 individuals (3-15 per population). In a cluster analysis of genetic similarities most individuals (67%) were arranged in population-specific clusters. Analysis of molecular variance indicated significant genetic differentiation among populations and among and within subpopulations (P < 0.001). Gene flow (N(e) m) was low (0.298). On average, plants produced 55 capsules, 17 seeds per fruit, and 42 seedlings in the following growing season. The number of seeds per capsule was independent of population size and of genetic variability. In contrast, the number of capsules per plant (P < 0.05) and the number of seedlings per plant (P < 0.05) were positively correlated with population size. The relation between population size and the number of seeds per plant was not significant (P = 0.075). The number of capsules and of seeds and seedlings per plant (P < 0.01) were positively correlated with genetic variability. Genetic variability was independent of actual population size, suggesting that historical population processes have to be taken into account, too. Stepwise multiple regressions revealed additional significant relationships of habitat parameters (soil pH, C:N ratio), vegetation composition, and standing crop on reproductive components. We conclude that populations of P. palustris are genetically isolated and that reproductive success most likely is influenced by population size, genetic variability, and habitat quality. Management strategies such as moderate grazing, mowing, and artificial gene flow should endeavor to increase population size as well as genetic variation.

  3. Post-Disturbance Plant Community Dynamics following a Rare Natural-Origin Fire in a Tsuga canadensis Forest

    PubMed Central

    Murray, Bryan D.; Holmes, Stacie A.; Webster, Christopher R.; Witt, Jill C.

    2012-01-01

    Opportunities to directly study infrequent forest disturbance events often lead to valuable information about vegetation dynamics. In mesic temperate forests of North America, stand-replacing crown fire occurs infrequently, with a return interval of 2000–3000 years. Rare chance events, however, may have profound impacts on the developmental trajectories of forest ecosystems. For example, it has been postulated that stand-replacing fire may have been an important factor in the establishment of eastern hemlock (Tsuga canadensis) stands in the northern Great Lakes region. Nevertheless, experimental evidence linking hemlock regeneration to non-anthropogenic fire is limited. To clarify this potential relationship, we monitored vegetation dynamics following a rare lightning-origin crown fire in a Wisconsin hemlock-hardwood forest. We also studied vegetation in bulldozer-created fire breaks and adjacent undisturbed forest. Our results indicate that hemlock establishment was rare in the burned area but moderately common in the scarified bulldozer lines compared to the reference area. Early-successional, non-arboreal species including Rubus spp., Vaccinium angustifolium, sedges (Carex spp.), grasses, Epilobium ciliatum, and Pteridium aquilinium were the most abundant post-fire species. Collectively, our results suggest that competing vegetation and moisture stress resulting from drought may reduce the efficacy of scarification treatments as well as the usefulness of fire for preparing a suitable seedbed for hemlock. The increasing prevalence of growing-season drought suggests that silvicultural strategies based on historic disturbance regimes may need to be reevaluated for mesic species. PMID:22928044

  4. Post-disturbance plant community dynamics following a rare natural-origin fire in a Tsuga canadensis forest.

    PubMed

    Murray, Bryan D; Holmes, Stacie A; Webster, Christopher R; Witt, Jill C

    2012-01-01

    Opportunities to directly study infrequent forest disturbance events often lead to valuable information about vegetation dynamics. In mesic temperate forests of North America, stand-replacing crown fire occurs infrequently, with a return interval of 2000-3000 years. Rare chance events, however, may have profound impacts on the developmental trajectories of forest ecosystems. For example, it has been postulated that stand-replacing fire may have been an important factor in the establishment of eastern hemlock (Tsuga canadensis) stands in the northern Great Lakes region. Nevertheless, experimental evidence linking hemlock regeneration to non-anthropogenic fire is limited. To clarify this potential relationship, we monitored vegetation dynamics following a rare lightning-origin crown fire in a Wisconsin hemlock-hardwood forest. We also studied vegetation in bulldozer-created fire breaks and adjacent undisturbed forest. Our results indicate that hemlock establishment was rare in the burned area but moderately common in the scarified bulldozer lines compared to the reference area. Early-successional, non-arboreal species including Rubus spp., Vaccinium angustifolium, sedges (Carex spp.), grasses, Epilobium ciliatum, and Pteridium aquilinium were the most abundant post-fire species. Collectively, our results suggest that competing vegetation and moisture stress resulting from drought may reduce the efficacy of scarification treatments as well as the usefulness of fire for preparing a suitable seedbed for hemlock. The increasing prevalence of growing-season drought suggests that silvicultural strategies based on historic disturbance regimes may need to be reevaluated for mesic species.

  5. Relationships between rare plants of the White Mountains and the late Cenozoic geology of the Colorado Plateau

    Treesearch

    Jonathan W. Long

    2007-01-01

    A complex geologic history has shaped the distribution of Arizona willow (Salix arizonica Dorn) and the Mogollon paintbrush (Castilleja mogollonica Pennell). These subalpine plants do not appear to be strict substrate specialists, but they do seem to favor coarse-textured and well-watered soils. Most of their occupied habitats were...

  6. Status and limiting factors of two rare plant species in dry montane communities of Hawai`i Volcanoes National Park.

    USGS Publications Warehouse

    Pratt, Linda W.; VanDeMark, Joshua R.; Euaparadorn, Melody

    2012-01-01

    Silene hawaiiensis had a stable population structure at the Mauna Loa study area, but its population structure at the Kīlauea study site was flat to declining. Mortality of adult plants was low on Mauna Loa (6.5%), but was greater than 30% at the Kīlauea Crater Rim site. Among regularly monitored plants at the Kīlauea site, losses were observed in all size classes between 2006 and 2008. Natural seedling recruitment was observed in stand structure plots at both sites between 2006 and 2007, but numbers of seedlings were low and did not compensate for losses of adult plants. Reproductive phenology was annual with buds and flowers observed in summer and fall, and fruit formed in the fall and winter. The production of immature fruit capsules from buds and flowers was high (51.2%) and tagged immature fruit became mature fruit at a high rate of 66.7%. Floral visitation rates were very low in timed observations and only three insect species were identified visiting S. hawaiiensis flowers: native yellow-faced bees Hylaeus difficilis and H. volcanicus, and the alien hover fly Allograpta exotica. A seed dispersal experiment at the Kīlauea Crater Rim site demonstrated that wind dispersed seeds could travel at least 40 m from S. hawaiiensis plants with mature open capsules. Seed germination rates varied from 7.0 to 73.0% in greenhouse trials. Mortality of planted seedlings at Kahuku was not significantly greater outside ungulate exclosures than inside, but growth in height and production of reproductive structures was significantly greater in protected areas inside exclosures. In the current study, the seedling stage was the most vulnerable part of the life cycle for both P. stachyoides and S. hawaiiensis, and low seedling recruitment appeared to be the most important limiting factor for these species

  7. Isolation, Diversity, and Antimicrobial Activity of Rare Actinobacteria from Medicinal Plants of Tropical Rain Forests in Xishuangbanna, China▿ †

    PubMed Central

    Qin, Sheng; Li, Jie; Chen, Hua-Hong; Zhao, Guo-Zhen; Zhu, Wen-Yong; Jiang, Cheng-Lin; Xu, Li-Hua; Li, Wen-Jun

    2009-01-01

    Endophytic actinobacteria are relatively unexplored as potential sources of novel species and novel natural products for medical and commercial exploitation. Xishuangbanna is recognized throughout the world for its diverse flora, especially the rain forest plants, many of which have indigenous pharmaceutical histories. However, little is known about the endophytic actinobacteria of this tropical area. In this work, we studied the diversity of actinobacteria isolated from medicinal plants collected from tropical rain forests in Xishuangbanna. By the use of different selective isolation media and methods, a total of 2,174 actinobacteria were isolated. Forty-six isolates were selected on the basis of their morphologies on different media and were further characterized by 16S rRNA gene sequencing. The results showed an unexpected level of diversity, with 32 different genera. To our knowledge, this is the first report describing the isolation of Saccharopolyspora, Dietzia, Blastococcus, Dactylosporangium, Promicromonospora, Oerskovia, Actinocorallia, and Jiangella species from endophytic environments. At least 19 isolates are considered novel taxa by our current research. In addition, all 46 isolates were tested for antimicrobial activity and were screened for the presence of genes encoding polyketide synthetases and nonribosomal peptide synthetases. The results confirm that the medicinal plants of Xishuangbanna represent an extremely rich reservoir for the isolation of a significant diversity of actinobacteria, including novel species, that are potential sources for the discovery of biologically active compounds. PMID:19648362

  8. Phosphoenol Pyruvate Carboxylase in Parasitic Plants: Further Characterization in Various Species and Localization at the Level of Cells and Tissues in Lathraea clandestina L.

    PubMed

    Renaudin, S; Thalouarn, P; Rey, L; Vidal, J; Larher, F

    1984-11-01

    Phosphoenolpyruvate carboxylase (PEP carboxylase, EC 4.1.1.31) activity was demonstrated in a range of holo and hemiparasitic phanerogams. Lathraea clandestina was used as a model for a more detailed study. Enzyme activity levels were determined in the various plant parts. Great changes in enzyme capacity were observed in the shoots according to the time of measurement during a 24 hr cycle. PEP carboxylase characterized at the cellular level by using an indirect immunofluorescence method was found to be mainly located in the cytosol. The possible functions of PEP carboxylase in parasitic plants are discussed. Copyright © 1984 Gustav Fischer Verlag, Stuttgart. Published by Elsevier GmbH.. All rights reserved.

  9. Thorium, uranium and rare earth elements content in lanthanide concentrate (LC) and water leach purification (WLP) residue of Lynas advanced materials plant (LAMP)

    SciTech Connect

    AL-Areqi, Wadeeah M. Majid, Amran Ab. Sarmani, Sukiman

    2014-02-12

    Lynas Advanced Materials Plant (LAMP) has been licensed to produce the rare earths elements since early 2013 in Malaysia. LAMP processes lanthanide concentrate (LC) to extract rare earth elements and subsequently produce large volumes of water leach purification (WLP) residue containing naturally occurring radioactive material (NORM). This residue has been rising up the environmental issue because it was suspected to accumulate thorium with significant activity concentration and has been classified as radioactive residue. The aim of this study is to determine Th-232, U-238 and rare earth elements in lanthanide concentrate (LC) and water leach purification (WLP) residue collected from LAMP and to evaluate the potential radiological impacts of the WLP residue on the environment. Instrumental Neutron Activation Analysis and γ-spectrometry were used for determination of Th, U and rare earth elements concentrations. The results of this study found that the concentration of Th in LC was 1289.7 ± 129 ppm (5274.9 ± 527.6Bq/kg) whereas the Th and U concentrations in WLP were determined to be 1952.9±17.6 ppm (7987.4 ± 71.9 Bq/kg) and 17.2 ± 2.4 ppm respectively. The concentrations of Th and U in LC and WLP samples determined by γ- spectrometry were 1156 ppm (4728 ± 22 Bq/kg) and 18.8 ppm and 1763.2 ppm (7211.4 Bq/kg) and 29.97 ppm respectively. This study showed that thorium concentrations were higher in WLP compare to LC. This study also indicate that WLP residue has high radioactivity of {sup 232}Th compared to Malaysian soil natural background (63 - 110 Bq/kg) and come under preview of Act 304 and regulations. In LC, the Ce and Nd concentrations determined by INAA were 13.2 ± 0.6% and 4.7 ± 0.1% respectively whereas the concentrations of La, Ce, Nd and Sm in WLP were 0.36 ± 0.04%, 1.6%, 0.22% and 0.06% respectively. This result showed that some amount of rare earth had not been extracted and remained in the WLP and may be considered to be reextracted.

  10. Thorium, uranium and rare earth elements content in lanthanide concentrate (LC) and water leach purification (WLP) residue of Lynas advanced materials plant (LAMP)

    NASA Astrophysics Data System (ADS)

    AL-Areqi, Wadeeah M.; Majid, Amran Ab.; Sarmani, Sukiman

    2014-02-01

    Lynas Advanced Materials Plant (LAMP) has been licensed to produce the rare earths elements since early 2013 in Malaysia. LAMP processes lanthanide concentrate (LC) to extract rare earth elements and subsequently produce large volumes of water leach purification (WLP) residue containing naturally occurring radioactive material (NORM). This residue has been rising up the environmental issue because it was suspected to accumulate thorium with significant activity concentration and has been classified as radioactive residue. The aim of this study is to determine Th-232, U-238 and rare earth elements in lanthanide concentrate (LC) and water leach purification (WLP) residue collected from LAMP and to evaluate the potential radiological impacts of the WLP residue on the environment. Instrumental Neutron Activation Analysis and γ-spectrometry were used for determination of Th, U and rare earth elements concentrations. The results of this study found that the concentration of Th in LC was 1289.7 ± 129 ppm (5274.9 ± 527.6Bq/kg) whereas the Th and U concentrations in WLP were determined to be 1952.9±17.6 ppm (7987.4 ± 71.9 Bq/kg) and 17.2 ± 2.4 ppm respectively. The concentrations of Th and U in LC and WLP samples determined by γ- spectrometry were 1156 ppm (4728 ± 22 Bq/kg) & 18.8 ppm and 1763.2 ppm (7211.4 Bq/kg) &29.97 ppm respectively. This study showed that thorium concentrations were higher in WLP compare to LC. This study also indicate that WLP residue has high radioactivity of 232Th compared to Malaysian soil natural background (63 - 110 Bq/kg) and come under preview of Act 304 and regulations. In LC, the Ce and Nd concentrations determined by INAA were 13.2 ± 0.6% and 4.7 ± 0.1% respectively whereas the concentrations of La, Ce, Nd and Sm in WLP were 0.36 ± 0.04%, 1.6%, 0.22% and 0.06% respectively. This result showed that some amount of rare earth had not been extracted and remained in the WLP and may be considered to be reextracted.

  11. [Molecular characterization of a HMG-CoA reductase gene from a rare and endangered medicinal plant, Dendrobium officinale].

    PubMed

    Zhang, Lin; Wang, Ji-Tao; Zhang, Da-Wei; Zhang, Gang; Guo, Shun-Xing

    2014-03-01

    The 3-hydroxy-3-methylglutaryl-CoA reductase (HMGR) catalyzes the conversion of HMG-CoA to mevalonate in mavalonic acid pathway, which is the first committed step for isoprenoid biosynthesis in plants. However, it still remains unclear whether HGMR gene plays a role in the isoprenoid biosynthesis in Dendrobium officinale, an endangered epiphytic orchid species. In the present study, a HMGR encoding gene, designed as DoHMGR1 (GenBank accession JX272632), was identified from D. officinale using the reverse transcription polymerase chain reaction (RT-PCR) and rapid amplification of cDNA ends (RACE) methods, for the first time. The full length cDNA of DoHMGR1 was 2 071 bp in length and encoded a 562-aa protein with a molecular weight of 59.73 kD and an isoelectric point (pI) of 6.18. The deduced DoHMGR1 protein, like other HMGR proteins, constituted four conserved domains (63-561, 147-551, 268-383 and 124-541) and two transmembrane motifs (42-64 and 85-107). Multiple sequence alignment and phylogenetic analyses demonstrated that DoHMGR1 had high identity (67%-89%) to a number of HMGR genes from various plants and was closely related to Vanda hybrid cultivar, rice and maize monocots. Real time quantitative PCR (qPCR) analysis revealed that DoHMGR1 was expressed in the three included organs. The transcripts were the most abundant in the roots with 2.13 fold over that in the leaves, followed by that in the stems with 1.98 fold. Molecular characterization of DoHMGR1 will be useful for further functional elucidation of the gene involving in isoprenoid biosynthesis pathway in D. officinale.

  12. Precious metals and rare earth elements in municipal solid waste--sources and fate in a Swiss incineration plant.

    PubMed

    Morf, Leo S; Gloor, Rolf; Haag, Olaf; Haupt, Melanie; Skutan, Stefan; Di Lorenzo, Fabian; Böni, Daniel

    2013-03-01

    In Switzerland many kinds of waste, e.g. paper, metals, electrical and electronic equipment are separately collected and recycled to a large extent. The residual amount of municipal solid waste (MSW) has to be thermally treated before final disposal. Efforts to recover valuable metals from incineration residues have recently increased. However, the resource potential of critical elements in the waste input (sources) and their partitioning into recyclable fractions and residues (fate) is unknown. Therefore, a substance flow analysis (SFA) for 31 elements including precious metals (Au, Ag), platinum metal group elements (Pt, Rh) and rare earth elements (La, Ce, etc.) has been conducted in a solid waste incinerator (SWI) with a state-of-the-art bottom ash treatment according to the Thermo-Re® concept. The SFA allowed the determination of the element partitioning in the SWI, as well as the elemental composition of the MSW by indirect analysis. The results show that the waste-input contains substantial quantities of precious metals, such as 0.4 ± 0.2mg/kg Au and 5.3 ± 0.7 mg/kg Ag. Many of the valuable substances, such as Au and Ag are enriched in specific outputs (e.g. non-ferrous metal fractions) and are therefore recoverable. As the precious metal content in MSW is expected to rise due to its increasing application in complex consumer products, the results of this study are essential for the improvement of resource recovery in the Thermo-Re® process.

  13. Role of ligands in accumulation and fractionation of rare Earth elements in plants: examples of phosphate and citrate.

    PubMed

    Ding, Shiming; Liang, Tao; Zhang, Chaosheng; Yan, Juncai; Zhang, Zili; Sun, Qin

    2005-10-01

    Few studies have been carried out on the effects of ligands on rare earth element (REE) bioaccumulation processes. In this study, the effects of phosphate (Pi, an inorganic ligand) and citrate (an organic ligand) on accumulation and fractionation of REEs in wheat were investigated using aqueous culture with extraneous mixed REEs (MRE). The results show that initial Pi solution culture at various levels followed by exposure to a fixed-MRE solution did not significantly change the total concentrations of REEs (SigmaREE) in roots, whereas the SigmaREE in leaves dramatically decreased with increasing levels of Pi applied. Simultaneous culture of wheat with mixture of MRE and citrate solutions caused obvious decreases of the SigmaREE in both roots and leaves. Compared with MRE, significant fractionations of REEs were found in wheat organs when no ligand was applied. Notable middle REE (MREE) enrichment and M-type tetrad effect were observed in the roots, and heavy REE (HREE) enrichment and W-type tetrad effect existed in the leaves. Pi treatments did not significantly affect the fractionations of REEs in the roots, but enrichment of HREEs in the leaves slightly increased at the highest level of Pi applied. Fractionations of REEs in both roots and leaves decreased with increasing levels of citrate applied; at higher levels of citrate (> or =150 microM), no above fractionation features were observed in wheat, but light REE (LREE) enrichment existed in the roots and leaves. The results indicate that ligands might play important roles in accumulation and fractionation of REEs during bioaccumulation processes.

  14. Precious metals and rare earth elements in municipal solid waste – Sources and fate in a Swiss incineration plant

    SciTech Connect

    Morf, Leo S.; Gloor, Rolf; Haag, Olaf; Haupt, Melanie; Skutan, Stefan; Lorenzo, Fabian Di; Böni, Daniel

    2013-03-15

    Highlights: ► We carefully addressed all the very valuable comments and suggestions of the reviewers. ► We also have shortened the size of the paper and tried simplify it substantially, as requested by the reviewers (introduction 25% reduced!). ► We have decided to take the chance and have replaced the data for the “additional” elements (Cu, Cd, Zn, Pb, Sn, Cr, Ni, Fe, Al) of the earlier MFA (Morf, 2011) with data that belong to the samples of this study. ► We are convinced that with the revision the paper has significantly improved in quality and attractiveness. - Abstract: In Switzerland many kinds of waste, e.g. paper, metals, electrical and electronic equipment are separately collected and recycled to a large extent. The residual amount of municipal solid waste (MSW) has to be thermally treated before final disposal. Efforts to recover valuable metals from incineration residues have recently increased. However, the resource potential of critical elements in the waste input (sources) and their partitioning into recyclable fractions and residues (fate) is unknown. Therefore, a substance flow analysis (SFA) for 31 elements including precious metals (Au, Ag), platinum metal group elements (Pt, Rh) and rare earth elements (La, Ce, etc.) has been conducted in a solid waste incinerator (SWI) with a state-of-the-art bottom ash treatment according to the Thermo-Re® concept. The SFA allowed the determination of the element partitioning in the SWI, as well as the elemental composition of the MSW by indirect analysis. The results show that the waste-input contains substantial quantities of precious metals, such as 0.4 ± 0.2 mg/kg Au and 5.3 ± 0.7 mg/kg Ag. Many of the valuable substances, such as Au and Ag are enriched in specific outputs (e.g. non-ferrous metal fractions) and are therefore recoverable. As the precious metal content in MSW is expected to rise due to its increasing application in complex consumer products, the results of this study are

  15. An efficient plant regeneration system through callus for Pseudarthria viscida (L.) Wright and Arn., a rare ethnomedicinal herb.

    PubMed

    Cheruvathur, Meena K; Thomas, T Dennis

    2011-10-01

    The purpose of this study was to develop a protocol to induce high frequency of callus and subsequent plantlet regeneration for Pseudarthria viscida; an important medicinal plant. The cotyledonary node and young leaf pieces (1 × 0.5 cm, length × breadth) were used as explants for callus induction and subsequent shoot regeneration and adventitious roots induction from the shoots. The best results were achieved on the following media: (1) 96 % callus induction from cotyledonary node explants on MS medium supplemented with 1.5 mgl(-1) 2, 4 dichlorophenoxyacetic acid (2, 4-D) and 0.5 mgl(-1) 1-naphthalene acetic acid (NAA), (2) 97 % shoot regeneration from cotyledonary node derived calli with an average of 44.9 shoots per explant on MS medium fortified with 3.0 mgl(-1) N6-benzylaminopurine (BA) and 1 mgl(-1) NAA,37 (3) 98 % rooting with an average number of 3.3 roots per shoot on MS medium containing indole-3-butyric acid (IBA) or NAA (0.5-4 mgl(-1)) after 45 days. The plantlets were transferred to the field after acclimatization. Of the 40 plantlets transplanted to the soil, 29 survived (72.5 %).

  16. Genetic Diversity and Population Structure of the Rare and Endangered Plant Species Pulsatilla patens (L.) Mill in East Central Europe.

    PubMed

    Szczecińska, Monika; Sramko, Gabor; Wołosz, Katarzyna; Sawicki, Jakub

    2016-01-01

    Pulsatilla patens s.s. is a one of the most endangered plant species in Europe. The present range of this species in Europe is highly fragmented and the size of the populations has been dramatically reduced in the past 50 years. The rapid disappearance of P. patens localities in Europe has prompted the European Commission to initiate active protection of this critically endangered species. The aim of this study was to estimate the degree and distribution of genetic diversity within European populations of this endangered species. We screened 29 populations of P. patens using a set of six microsatellite primers. The results of our study indicate that the analyzed populations are characterized by low levels of genetic diversity (Ho = 0.005) and very high levels of inbreeding (FIS = 0.90). These results suggest that genetic erosion could be partially responsible for the lower fitness in smaller populations of this species. Private allelic richness was very low, being as low as 0.00 for most populations. Average genetic diversity over loci and mean number of alleles in P. patens populations were significantly correlated with population size, suggesting severe genetic drift. The results of AMOVA point to higher levels of variation within populations than between populations.The results of Structure and PCoA analyses suggest that the genetic structure of the studied P. patens populations fall into three clusters corresponding to geographical regions. The most isolated populations (mostly from Romania) formed a separate group with a homogeneous gene pool located at the southern, steppic part of the distribution range. Baltic, mostly Polish, populations fall into two genetic groups which were not fully compatible with their geographic distribution.Our results indicate the serious genetic depauperation of P. patens in the western part of its range, even hinting at an ongoing extinction vortex. Therefore, special conservation attention is required to maintain the populations

  17. Genetic Diversity and Population Structure of the Rare and Endangered Plant Species Pulsatilla patens (L.) Mill in East Central Europe

    PubMed Central

    Szczecińska, Monika; Sramko, Gabor; Wołosz, Katarzyna; Sawicki, Jakub

    2016-01-01

    Pulsatilla patens s.s. is a one of the most endangered plant species in Europe. The present range of this species in Europe is highly fragmented and the size of the populations has been dramatically reduced in the past 50 years. The rapid disappearance of P. patens localities in Europe has prompted the European Commission to initiate active protection of this critically endangered species. The aim of this study was to estimate the degree and distribution of genetic diversity within European populations of this endangered species. We screened 29 populations of P. patens using a set of six microsatellite primers. The results of our study indicate that the analyzed populations are characterized by low levels of genetic diversity (Ho = 0.005) and very high levels of inbreeding (FIS = 0.90). These results suggest that genetic erosion could be partially responsible for the lower fitness in smaller populations of this species. Private allelic richness was very low, being as low as 0.00 for most populations. Average genetic diversity over loci and mean number of alleles in P. patens populations were significantly correlated with population size, suggesting severe genetic drift. The results of AMOVA point to higher levels of variation within populations than between populations.The results of Structure and PCoA analyses suggest that the genetic structure of the studied P. patens populations fall into three clusters corresponding to geographical regions. The most isolated populations (mostly from Romania) formed a separate group with a homogeneous gene pool located at the southern, steppic part of the distribution range. Baltic, mostly Polish, populations fall into two genetic groups which were not fully compatible with their geographic distribution.Our results indicate the serious genetic depauperation of P. patens in the western part of its range, even hinting at an ongoing extinction vortex. Therefore, special conservation attention is required to maintain the populations

  18. Metal contamination status of the soil-plant system and effects on the soil microbial community near a rare metal recycling smelter.

    PubMed

    Li, Zhu; Ma, Tingting; Yuan, Cheng; Hou, Jinyu; Wang, Qingling; Wu, Longhua; Christie, Peter; Luo, Yongming

    2016-09-01

    Four heavy metals (Cd, Cu, Pb and Zn), two metalloids (As and Sb) and two rare metals (In and Tl) were selected as target elements to ascertain their concentrations and accumulation in the soil-plant system and their effects on the structure of the soil microbial community in a typical area of rare metal smelting in south China. Twenty-seven soil samples 100, 500, 1000, 1500 and 3000 m from the smelter and 42 vegetable samples were collected to determine the concentrations of the target elements. Changes in soil micro-organisms were investigated using the Biolog test and 454 pyrosequencing. The concentrations of the eight target elements (especially As and Cd) were especially high in the topsoil 100 m from the smelter and decreased markedly with increasing distance from the smelter and with increasing soil depth. Cadmium bio-concentration factors in the vegetables were the highest followed by Tl, Cu, Zn, In, Sb, Pb, and then As. The concentrations of As, Cd and Pb in vegetables were 86.7, 100 and 80.0 %, respectively, over the permissible limits and possible contamination by Tl may also be of concern. Changes in soil microbial counts and average well colour development were also significantly different at different sampling distances from the smelter. The degree of tolerance to heavy metals appears to be fungi > bacteria > actinomycetes. The 454 pyrosequencing indicates that long-term metal contamination from the smelting activities has resulted in shifts in the composition of the soil bacterial community.

  19. Concerning the preliminary results of space experiment with the seeds of rare plants (on the boad of BION-M No.1)

    NASA Astrophysics Data System (ADS)

    Gorelov, Yury; Kurganskaya, Lubov; Ilyin, Vyacheslav; Ruzaeva, Irina; Rozno, Svetlana; Kavelenova, Ludmila

    The problem of native flora plants conservation appears today as one of the most actual for humanity. The wide spreading natural ecosystems degradation results in the status changes for formerly common species to rare, endangered or extincted ones. That is why the complex of biological diversity conservation measures must be used including ex situ and in situ forms. Last years the seed banks (special seed collections in controlled conditions, including temperature below zero) and field banks (special alive plants collections) were created in many countries taking in mind the future of humanity. The seed banks as long-term depositories can be placed on the space stations where the threat of earth catastrophes is removed. But we must make it clear how the complex of space flight factors effects upon the seed quality and germination and plants development from “cosmic” seeds. For instance, the action of residual ionizing radiation into space apparatus on plant seeds can alter its vitality maybe by the growth of free radicals pool in molecular and subcellular level. The unknown level of such action permits us to propose wide diapason of effects from the absence of any changes to the stimulation of vital activity, decrease of it, mutagenesis and maybe the death of seeds. Only the experiments that begin in space and continue on the Earth can show us the effect of space flight factors complex on plant seeds. Here we describe the first results of experiment held on the board of space apparatus “Bion-M” No1. Totally 79 experiments were included to the program of “Bion-M”, among them the experiment “Biocont-BS”. The equipment for it was prepared by Central Scientific Research Institute of Machine-building; the seed material was selected and prepared by the Botanical Garden of Samara State University. The equipment with seeds was into space apparatus, which working orbit was average 575 km and the flight lasted for 30 days. The seed samples of 9 rare plants

  20. Behavior and distribution of heavy metals including rare Earth elements, thorium, and uranium in sludge from industry water treatment plant and recovery method of metals by biosurfactants application.

    PubMed

    Gao, Lidi; Kano, Naoki; Sato, Yuichi; Li, Chong; Zhang, Shuang; Imaizumi, Hiroshi

    2012-01-01

    In order to investigate the behavior, distribution, and characteristics of heavy metals including rare earth elements (REEs), thorium (Th), and uranium (U) in sludge, the total and fractional concentrations of these elements in sludge collected from an industry water treatment plant were determined and compared with those in natural soil. In addition, the removal/recovery process of heavy metals (Pb, Cr, and Ni) from the polluted sludge was studied with biosurfactant (saponin and sophorolipid) elution by batch and column experiments to evaluate the efficiency of biosurfactant for the removal of heavy metals. Consequently, the following matters have been largely clarified. (1) Heavy metallic elements in sludge have generally larger concentrations and exist as more unstable fraction than those in natural soil. (2) Nonionic saponin including carboxyl group is more efficient than sophorolipid for the removal of heavy metals in polluted sludge. Saponin has selectivity for the mobilization of heavy metals and mainly reacts with heavy metals in F3 (the fraction bound to carbonates) and F5 (the fraction bound to Fe-Mn oxides). (3) The recovery efficiency of heavy metals (Pb, Ni, and Cr) reached about 90-100% using a precipitation method with alkaline solution.

  1. Studies of transport pathways of Th, rare earths, Ra-228, and Ra-226 from soil to plants and farm animals. Progress report, April 1, 1985-February 28, 1986

    SciTech Connect

    Linsalata, P.

    1986-02-01

    The field study is to assess the soil-to-plant and soil-to-animal concentration factors of the naturally occurring radionuclides /sup 226/Ra, /sup 228/Ra, /sup 232/Th, /sup 230/Th, and /sup 228/Th, as well as of the light rare earth elements (REE), La, Ce and Nd. Farms situated near the center of a deeply weathered alkalic intrusive known as the Pocos de Caldas (PC) plateau were selected for study because of their proximity (i.e., within a few kilometers) to what may be the largest single near-surface deposit of Th (approx.30,000 tonnes) and REE's (>100,000 tonnes) situated near the summit of a hill (the Morro do Ferro (MF)). An ancillary field study is being conducted in Orange County, New York, where a local cattleman has permitted sampling members of the herd as well as soil and feeds which are all grown on the premises. Vegetable samples and soil have also been analyzed from five additional farms in Orange County, NY. 64 refs., 25 figs., 45 tabs.

  2. Behavior and Distribution of Heavy Metals Including Rare Earth Elements, Thorium, and Uranium in Sludge from Industry Water Treatment Plant and Recovery Method of Metals by Biosurfactants Application

    PubMed Central

    Gao, Lidi; Kano, Naoki; Sato, Yuichi; Li, Chong; Zhang, Shuang; Imaizumi, Hiroshi

    2012-01-01

    In order to investigate the behavior, distribution, and characteristics of heavy metals including rare earth elements (REEs), thorium (Th), and uranium (U) in sludge, the total and fractional concentrations of these elements in sludge collected from an industry water treatment plant were determined and compared with those in natural soil. In addition, the removal/recovery process of heavy metals (Pb, Cr, and Ni) from the polluted sludge was studied with biosurfactant (saponin and sophorolipid) elution by batch and column experiments to evaluate the efficiency of biosurfactant for the removal of heavy metals. Consequently, the following matters have been largely clarified. (1) Heavy metallic elements in sludge have generally larger concentrations and exist as more unstable fraction than those in natural soil. (2) Nonionic saponin including carboxyl group is more efficient than sophorolipid for the removal of heavy metals in polluted sludge. Saponin has selectivity for the mobilization of heavy metals and mainly reacts with heavy metals in F3 (the fraction bound to carbonates) and F5 (the fraction bound to Fe-Mn oxides). (3) The recovery efficiency of heavy metals (Pb, Ni, and Cr) reached about 90–100% using a precipitation method with alkaline solution. PMID:22693485

  3. Effects of organic ligands on fractionation of rare earth elements (REEs) in hydroponic plants: an application to the determination of binding capacities by humic acid for modeling.

    PubMed

    Ding, ShiMing; Liang, Tao; Zhang, ChaoSheng; Yan, JunCai; Zhang, ZiLi

    2006-12-01

    Previous studies have revealed the fractionation processes of rare earth elements (REEs) in hydroponic plants, with a heavy REE (HREE, the elements from Gd to Lu) enrichment in leaves. In this study, effects on the HREE enrichment in soybean leaves with additions of carboxylic acids (acetate, malate, citrate, NTA, EDTA and DTPA) and two soil humic acids (HAs) were investigated. REE speciation in carboxylic acid and HA solutions was simulated using Visual MINTEQ and Model V, respectively. The results showed that the effects caused by carboxylic acids were strongly dependent on the differences between their binding strengths for light REEs (LREEs, the elements from La to Eu) and those for HREEs. A good correlation existed between these effects and the changes of free REE ions in solutions. This relationship was also observed for the HA treatments, provided that the intrinsic equilibrium constants of REEs for cation-proton exchange with HA (i.e., pK(MHA)) in Model V were estimated using a free-energy relationship with the stability constants for REE complexation with lactic acid. It is suggested that this set of pK(MHA) values is more suitable for use in Model V for the simulation of REE complexation with HA.

  4. Quantifying the discrepancy between regional climate and climate in the micro-habitats of a rare, endemic plant of the Alps

    NASA Astrophysics Data System (ADS)

    Patsiou, Theofania-Sotiria; Conti, Elena; Theodoridis, Spyros; Körner, Christian; Randin, Christophe-François

    2014-05-01

    Alpine vegetation is predicted to be extremely vulnerable to climate change. Effects of ongoing climate warming on plant species have already been reported in the Alps, such as upward shift of species distribution, range contraction or changes in species composition in the form of thermophilisation. Extrinsic factors such as land-area reduction occurring at high elevations in a mountain range and species' intrinsic properties (e.g., their growth form, reproductive strategy or dispersal capacity) are both affecting the response of alpine species to rapid climate change. However, recent studies have shown that the topographic complexity usually found in the alpine zones creates a variety of microclimate conditions that counteract the effect of warming climate. Here we aimed at characterising the microclimate conditions that alpine plant species experience. We used a rare endemic plant of the Maritime Alps, Saxifraga florulenta, as a model taxon because of its specific topographic and edaphic requirements. We hypothesized that temperature conditions at sites where populations of S. florulenta are located are decoupled from the local and regional climate. We also hypothesised topographic-related factors are better predictors than other proxies constrained by elevation only to explain the variation of water stress. To test these hypotheses, we recorded temperature conditions at the microsite where individual grow and reconstructed 30-year time series. We used stable isotopes signal (13C) as the best proxies for water availability. We then compared our recorded temperature data to temperature produced by coarse scale geographic climate layers that are commonly used for predicting species distribution under current and changing climate. We found that the reconstructed extreme temperatures were significantly different from the temperatures of the coarse scale geographic climate layers. In particular, the reconstructed maximum temperatures were lower than the ones of the

  5. Rare earths

    SciTech Connect

    Vijayan, S.; Melnyk, A.J.; Singh, R.D.; Nuttall, K.

    1989-01-01

    For conventional applications, there is limited demand for rare earth elements as well as yttrium and scandium. But the emergence of new high technology applications such as supermagnets, lasers, and superconductors should result in significant demand for some of these elements. This article examines the anticipated applications and demands for rare earth elements over the next decade. It also looks at the implications on the use of available resources. In the context of a growing demand, process methods are reviewed for the recovery of rare earth elements from conventional and unconventional resources. And the article also discusses the challenges facing the mining industry in meeting this opportunity.

  6. Rare earths

    USGS Publications Warehouse

    Gambogi, J.

    2013-01-01

    Global mine production of rare earths was estimated to have declined slightly in 2012 relative to 2011 (Fig. 1). Production in China was estimated to have decreased to 95 from 105 kt (104,700 from 115,700 st) in 2011, while new mine production in the United States and Australia increased.

  7. Rare events: a state of the art

    SciTech Connect

    Uppuluri, V.R.R.

    1980-12-01

    The study of rare events has become increasingly important in the context of nuclear safety. Some philosophical considerations, such as the framework for the definition of a rare event, rare events and science, rare events and trans-science, and rare events and public perception, are discussed. The technical work of the Task Force on problems of Rare Events in the Reliability Analysis of Nuclear Plants (1976-1978), sponsored by OECD, is reviewed. Some recent technical considerations are discussed, and conclusions are drawn. The appendix contains an essay written by Anne E. Beachey, under the title: A Study of Rare Events - Problems and Promises.

  8. Not so Rare, Rare Diseases

    ERIC Educational Resources Information Center

    Waldman, H. Barry; Perlman, Steven P.; Munter, Beverly L.; Chaudhry, Ramiz A.

    2008-01-01

    A rare disease or condition is defined by federal legislation such that it: (1) affects less than 200,000 persons in the U.S.; or (2) affects more than 200,000 persons in the U.S. but for which there is no reasonable expectation that the cost of developing and making available in the U.S. a drug for such disease or condition will be recovered from…

  9. Not so Rare, Rare Diseases

    ERIC Educational Resources Information Center

    Waldman, H. Barry; Perlman, Steven P.; Munter, Beverly L.; Chaudhry, Ramiz A.

    2008-01-01

    A rare disease or condition is defined by federal legislation such that it: (1) affects less than 200,000 persons in the U.S.; or (2) affects more than 200,000 persons in the U.S. but for which there is no reasonable expectation that the cost of developing and making available in the U.S. a drug for such disease or condition will be recovered from…

  10. Validity of specifically applied rare earth elements and compartmental models for estimating flux of undigested plant tissue residues through the gastrointestinal tract of ruminants.

    PubMed

    Ellis, W C; Wylie, M J; Matis, J H

    2002-10-01

    The validity of using rare earth elements as flow markers of undigested residues was evaluated by comparing mean gastrointestinal residence time (GMRT) of rare earths specifically applied to cottonseed hulls (CSH) to that of the indigestible fiber of CSH. Feces were collected from five lambs fed a mineral supplemented diet of CSH containing 52 g CP/kg DM and five lambs fed a CSH plus cottonseed meal diet (CSH+CSM) containing 123 g CP/kg DM. Rare earth elements (La, Yb, and Tb) specifically bound to CSH were included in the diet for a 5-d period and then deleted from the diet for a 3-d period. Following the last fecal collection, lambs were slaughtered for collection of digesta from segments of the gastrointestinal tract. Potentially indigestible NDF (PIF) was determined in diets and digesta from each segment of the gastrointestinal tract. Mean turnover rate, time delay, and GMRT for each rare earth element was estimated by fitting an age-dependent compartment model to profiles of markers appearing in the feces (compartmental model-marker method, CMM). The GMRT also was computed by the indigestible entity pool dilution method (IEPD) as grams of PIF in sampled segment/mean intake rate of PIF proceeding slaughter, g/h. The GMRT computed by the CMM and the IEPD methods did not significantly (P < 0.05) differ (99.6 vs 94.8 h and 58.9 vs 59.5 h for CMM vs IEPD and CSH and CSH+CSM diets, respectively). Regression of GMRT estimated for rare earths vs PIF yielded a highly significant regression (P = 0.001) with a regression coefficient of 0.94 +/- 0.016. It was concluded that rare earth elements applied to specific feeds are valid flow markers for the undigested residues derived from such marked feeds.

  11. [Severe contact-allergy dermatitis due to poison ivy--a plant that is rarely encountered in The Netherlands; a family history].

    PubMed

    Leclercq, R M F M

    2005-07-23

    In successive years, three members of the same family (a man and woman aged 46 years and their son, aged 20) constantly developed severe pruritic, erythematous, vesicular and bullous dermatitis in the spring and summer after working in the garden. Although the findings were consistent with a photophytotoxic dermatitis, the causative plant remained unclear. Oral therapy with high doses ofprednisolone was necessary. When the man travelled to the USA and visited a doctor there, he recognised the symptoms as those of contact dermatitis caused by poison ivy (Toxicodendron radicans), a plant that is found sporadically in the wild state in Europe. Their grandparents had brought the plant back from a trip to the USA and planted it in the garden because of the beautiful fall colours. The family identified the plant via a search on Internet and eliminated it from the garden completely. Since then, the family has no longer suffered from contact-allergy dermatitis.

  12. Status and limiting factors of three rare plant species in the coastal lowlands and mid-elevation woodlands of Hawai`i Volcanoes National Park

    USGS Publications Warehouse

    Pratt, Linda W.; VanDeMark, Joshua R.; Euaparadorn, Melody

    2011-01-01

    Two endangered plant species (Portulaca sclerocarpa, `ihi mākole, and Sesbania tomentosa, `ōhai) and a species of concern (Bobea timonioides, `ahakea) native to the coastal lowlands and dry mid-elevation woodlands of Hawai`i Volcanoes National Park were studied for more than two years to determine their stand structure, short-term mortality rates, patterns of reproductive phenology, success of fruit production, seed germination rates in the greenhouse, presence of soil seed bank, and survival of both natural and planted seedlings. The role of rodents as fruit and seed predators was evaluated using exclosures and seed offerings in open and closed stations or cages. Rodents were excluded from randomly selected plants of P. sclerocarpa and from branches of S. tomentosa, and flower and fruit production were compared to that of adjacent unprotected plants. Tagged S. tomentosa fruit were also monitored monthly to detect rodent predation.

  13. [Poisonous plants].

    PubMed

    Hoppu, Kalle; Mustonen, Harriet; Pohjalainen, Tiina

    2011-01-01

    Approximately ten species of dangerously poisonous plants are found in Finland. Severe plant poisonings are very rare. Edible plants eaten raw or wrongly processed may cause severe symptoms. As first aid, activated charcoal should be given to the person who has eaten a plant causing a risk of significant poisoning. In case of exposure to topically irritating plant fluids, the exposed person's eyes must be irrigated and mouth or skin washed with copious amounts of water. In combination with solar UV radiation, light-sensitizing plants cause local burns. The diagnosis of plant poisoning is usually based on incidental information; the plant should be identified in order to make the correct treatment decisions.

  14. Stable C & N isotopes in 2100 Year-B.P. human bone collagen indicate rare dietary dominance of C4 plants in NE-Italy

    NASA Astrophysics Data System (ADS)

    Laffranchi, Zita; Huertas, Antonio Delgado; Jiménez Brobeil, Sylvia A.; Torres, Arsenio Granados; Riquelme Cantal, Jose A.

    2016-12-01

    C4 plants (e.g. maize, millet), part of our current diet, are only endemic of reduced areas in South-Europe due to their need of warm climates. Since the first vestiges of agriculture in Europe remains of C4 plants were recorded but their overall proportion in the human diet remains unknown. Therefore, isotopic (δ13C and δ15N) composition of bone collagen from the skeletal remains (human and animals) of a Celtic population, Cenomani Gauls, from Verona (3rd to 1st century BC) in the NE Italy provide a new perspective on this matter. The δ13C collagen values of 90 human skeletal individuals range between ‑20.2‰ and ‑9.7‰ (V-PDB) with a mean value of ‑15.3‰. As present day C4 plants have δ13C values around ‑11‰, which is equivalent to ‑9.5‰ for samples of preindustrial age, the less negative δ13C values in these individuals indicate a diet dominated by C4 plants. This palaeodietary study indicates that some European populations predominantly consumed cultivated C4 plants 2100 year B.P. This is supported by the paleobotanical records and ancient Roman sources (e.g. Pliny the Elder), which indicate that millet was a staple food in South-Europe.

  15. Stable C & N isotopes in 2100 Year-B.P. human bone collagen indicate rare dietary dominance of C4 plants in NE-Italy

    PubMed Central

    Laffranchi, Zita; Huertas, Antonio Delgado; Jiménez Brobeil, Sylvia A.; Torres, Arsenio Granados; Riquelme Cantal, Jose A.

    2016-01-01

    C4 plants (e.g. maize, millet), part of our current diet, are only endemic of reduced areas in South-Europe due to their need of warm climates. Since the first vestiges of agriculture in Europe remains of C4 plants were recorded but their overall proportion in the human diet remains unknown. Therefore, isotopic (δ13C and δ15N) composition of bone collagen from the skeletal remains (human and animals) of a Celtic population, Cenomani Gauls, from Verona (3rd to 1st century BC) in the NE Italy provide a new perspective on this matter. The δ13C collagen values of 90 human skeletal individuals range between −20.2‰ and −9.7‰ (V-PDB) with a mean value of −15.3‰. As present day C4 plants have δ13C values around −11‰, which is equivalent to −9.5‰ for samples of preindustrial age, the less negative δ13C values in these individuals indicate a diet dominated by C4 plants. This palaeodietary study indicates that some European populations predominantly consumed cultivated C4 plants 2100 year B.P. This is supported by the paleobotanical records and ancient Roman sources (e.g. Pliny the Elder), which indicate that millet was a staple food in South-Europe. PMID:27934943

  16. Stable C &N isotopes in 2100 Year-B.P. human bone collagen indicate rare dietary dominance of C4 plants in NE-Italy.

    PubMed

    Laffranchi, Zita; Huertas, Antonio Delgado; Jiménez Brobeil, Sylvia A; Torres, Arsenio Granados; Riquelme Cantal, Jose A

    2016-12-09

    C4 plants (e.g. maize, millet), part of our current diet, are only endemic of reduced areas in South-Europe due to their need of warm climates. Since the first vestiges of agriculture in Europe remains of C4 plants were recorded but their overall proportion in the human diet remains unknown. Therefore, isotopic (δ(13)C and δ(15)N) composition of bone collagen from the skeletal remains (human and animals) of a Celtic population, Cenomani Gauls, from Verona (3(rd) to 1(st) century BC) in the NE Italy provide a new perspective on this matter. The δ(13)C collagen values of 90 human skeletal individuals range between -20.2‰ and -9.7‰ (V-PDB) with a mean value of -15.3‰. As present day C4 plants have δ(13)C values around -11‰, which is equivalent to -9.5‰ for samples of preindustrial age, the less negative δ(13)C values in these individuals indicate a diet dominated by C4 plants. This palaeodietary study indicates that some European populations predominantly consumed cultivated C4 plants 2100 year B.P. This is supported by the paleobotanical records and ancient Roman sources (e.g. Pliny the Elder), which indicate that millet was a staple food in South-Europe.

  17. Background levels of some major, trace, and rare earth elements in indigenous plant species growing in Norway and the influence of soil acidification, soil parent material, and seasonal variation on these levels.

    PubMed

    Gjengedal, Elin; Martinsen, Thomas; Steinnes, Eiliv

    2015-06-01

    Baseline levels of 43 elements, including major, trace, and rare earth elements (REEs) in several native plant species growing in boreal and alpine areas, are presented. Focus is placed on species metal levels at different soil conditions, temporal variations in plant tissue metal concentrations, and interspecies variation in metal concentrations. Vegetation samples were collected at Sogndal, a pristine site in western Norway, and at Risdalsheia, an acidified site in southernmost Norway. Metal concentrations in the different species sampled in western Norway are compared with relevant literature data from Norway, Finland, and northwest Russia, assumed to represent natural conditions. Except for aluminium (Al) and macronutrients, the levels of metals were generally lower in western Norway than in southern Norway and may be considered close to natural background levels. In southern Norway, the levels of cadmium (Cd) and lead (Pb) in particular appear to be affected by air pollution, either by direct atmospheric supply or through soil acidification. Levels of some elements show considerable variability between as well as within plant species. Calcium (Ca), magnesium (Mg), and potassium (K) are higher in most species at Sogndal compared to Risdalsheia, despite increased extractable concentrations in surface soil in the south, probably attributed to different buffer mechanisms in surface soil. Antagonism on plant uptake is suggested between Ca, Mg, and K on one hand and Al on the other. Tolerance among calcifuges to acid conditions and a particular ability to detoxify or avoid uptake of Al ions are noticeable for Vaccinium vitis-idaea.

  18. Isolation of microsatellite primers for Melampyrum sylvaticum (Orobanchaceae), an endangered plant in the United Kingdom.

    PubMed

    Crichton, Rhiannon J; Squirrell, Jane; Woodin, Sarah J; Dalrymple, Sarah E; Hollingsworth, Peter M

    2012-11-01

    Microsatellite markers were developed for the hemiparasitic plant Melampyrum sylvaticum to investigate the breeding system, genetic diversity, and structure of populations in the United Kingdom, Sweden, and Norway. Microsatellites were isolated from genomic DNA using an enrichment protocol. Twenty-nine loci were characterized in two individuals from each of 15 geographically disparate populations ("global"). Seven polymorphic loci were further characterized in one population ("local"). The number of alleles per locus ranged from two to 12 in the global sample and one to seven in the local sample. The expected heterozygosity ranged from 0-0.75, the observed heterozygosity from 0-0.1, and the inbreeding coefficient from 0.84-1 in the local sample. The results show the utility of these novel polymorphic microsatellite markers for further conservation genetic analyses. The strong deficit of heterozygosity across all loci in the local sample suggests the species may be inbreeding.

  19. Studies of transport pathways of Th, U, rare earths, Ra-228, and Ra-226 from soil to plants and farm animals: Final progress report, 1983-1988

    SciTech Connect

    Linsalata, P

    1988-07-01

    This report consists of three parts. Part 1 discusses a field study conducted in an area of enhanced, natural radioactivity to assess the soil to edible vegetable concentration ratios (CR = concentration in dry vegetable/concentration in dry soil) of Th-232, Th-230, Ra-226, Ra-228, and the light rare earth elements (REE's), La, Ce, and Nd. Twenty-eight soil, and approximately 42 vegetable samples consisting of relatively equal numbers of seven varieties, were obtained from 11 farms on the Pocos de Caldas Plateau in the state of Minas Gerais, Brazil. This region is the site of a major natural analogue study to assess the mobilization and retardation processes affecting thorium and the REE's at the Morro do Ferro ore body, and uranium series radionuclides at the Osamu Utsumi open pit uranium mine. Thorium (IV) serves as a chemical analogue for quadrivalent plutonium, the light REE's (III) as chemical analogues for trivalent americium and curium, and uranium (VI) as an analogue for transuranics with stable oxidation states above IV, e.g., Pu(VI). Part 2 includes our final measurement results for naturally occurring light rare earth elements (REE's include La, Ce, Nd, and SM), U-series and Th-series radionuclides in adult farm animal tissues, feeds and soils. Our findings on soil-to-tissue concentration ratios (CR's) and the comparative behavior of these elements in farm animals raised under natural conditions by local farmers are presented. Part 3 summarizes our findings to date on the distribution and mobilization of Th-232, light rare earth elements (LREE), U-238 and Ra-228 in the MF basin. Estimates of first order, present day, mobilization rate constants resulting from ground water solubilization and seepage/stream transport are calculated using revised inventory estimates for the occurrence of these elements in the ore body and annual flux estimates for the transport of these elements away from the ore body. 151 refs., 20 figs., 40 tabs.

  20. Rapid in vitro production of cloned plants of Uraria picta (Jacq.) DC-A rare medicinal herb in long-term culture.

    PubMed

    Rai, Santosh Kumar; Sharma, Meena; Jain, Madhu; Awasthi, Abhishek; Purshottam, Dharmendra Kumar; Nair, Narayanan Kuttanpillai; Sharma, Ashok Kumar

    2010-11-01

    An efficient in vitro process for rapid production of cloned plants of Uraria picta has been developed employing nodal stem segments taken from field-grown plants. Explants showed bud-break followed by regeneration of shoots with restricted growth within 12 days on modified Murashige and Skoog's medium supplemented with 0.25 mg l(-1) each of 6-benzylaminopurine and indole-3-acetic acid and 25 mg l(-1) adenine sulfate. Normal growth of shoots with good proliferation rate was achieved by reducing the concentrations of 6-benzylaminopurine and indole-3-acetic acid to 0.1 mg l(-1) each and incorporating 0.5 mg l(-1) gibberellic acid in the medium in which, on an average, 19.6 shoots per explant were produced. Further, during successive subcultures, increased concentrations of adenine sulfate (50 mg l(-l)) and gibberellic acid (2 mg l(-l)) along with the addition of 20 mg l(-l)  DL: -tryptophan were found conducive to control the problem of necrosis of shoots. In this treatment, several "crops" of shoots were obtained from single culture by repeated subculturing of basal portion of stalk in long-term. Isolated shoots rooted 100% in 0.25 mg l(-1) indole-3-butyric acid. In vitro-raised plants after hardening in inorganic salt solution grew normally in soil and came to flowering. Genetic fidelity of in vitro-raised plants was ascertained by rapid amplified polymorphic DNA (RAPD) markers. Also, quantitative estimation of two isoflavonones in their root extracts further confirmed true-to-type nature of plantlets.

  1. Benefits to rare plants and highway safety from annual population reductions of a "native invader," white-tailed deer, in a Chicago-area woodland.

    PubMed

    Engeman, Richard M; Guerrant, Travis; Dunn, Glen; Beckerman, Scott F; Anchor, Chris

    2014-01-01

    Overabundant white-tailed deer are one of the most serious threats to woodland plant communities in the Chicago area. Moreover, the abundant deer in a highly populated area causes economic harm and poses hazards to human safety through collisions with vehicles. The artificial conditions causing the overabundance and resulting consequences qualify the white-tailed deer in the Chicago area to be considered as "native invaders". We examined the benefits of culling deer at a Chicago-area woodland preserve by comparing browse rates on four endangered plant species from years before culling began with years with culling. We also examined deer-vehicle collision and traffic flow rates on area roads from years before culling began and years with culling to assess whether population reductions may have benefited road safety in the area. All four endangered plant species (three orchid species and sweet fern) had lower browse rates in years with culls, although the decreased browsing rates were statistically distinguishable for only two of the species (grass pink orchid and sweet fern). After first verifying that traffic flow rates did not decrease from pre-cull years to years with culls, we analyzed the Illinois Department of Transportation data from area roads based on deer-vehicle collisions causing >US$500 in damage and showed a one-third reduction in deer-vehicle collisions. An economic analysis showed a cost savings during the cull years of US$0.6 million for reducing browsing to just these four monitored plant species and the reduction in deer-vehicle collisions.

  2. Vulgarisin A, a new diterpenoid with a rare 5/6/4/5 ring skeleton from the Chinese medicinal plant Prunella vulgaris.

    PubMed

    Lou, Huayong; Zheng, Shan; Li, Tianlei; Zhang, Jianxin; Fei, Yue; Hao, Xiaojiang; Liang, Guangyi; Pan, Weidong

    2014-05-16

    Vulgarisin A (1), a new diterpenoid with an unprecedented 5/6/4/5 fused tetracyclic ring skeleton, has been isolated from the medicinal plant Prunella vulgaris Linn. Its structure was characterized by extensive spectroscopic methods, and the absolute configuration was secured by single crystal X-ray diffraction analysis. Compound 1 showed weak cytotoxicity against human lung carcinoma A549 cells with an IC50 value of 57.0 μM.

  3. Dispersal and disturbance as factors limiting the distribution of rare plant species at the Savannah River Site and the Carolina Sandhills National Wildlife Refuge.

    SciTech Connect

    Primack, Richard; Walker, Joan.

    2003-12-10

    An experiment was conducted to identify effective methods of creating new populations of herbaceous species in managed upland longleaf pine forest at two locations in the Fall-line Sandhills of South Carolina. We included thirteen species and a variety of site treatments. All sites were burned and lightly raked prior to planting. Sowing seeds on untreated or fertilized treatments resulted in the lowest establishment of all treatments. Digging the planting area to remove belowground plant structures and using hardware cloth cages to exclude potential mammalian seed predators and herbivores led to increased establishment of target species. Establishment was higher using seedling transplants compared to seeds. Success rate was highly variable among sites so population establishment efforts should try to incorporate many sites initially to find the sites that give the greatest chance of success, or increase efforts to carefully identify species, habitat requirements and screen potential sites accordingly. Some species showed very low rates of success despite the variety of methods used; for such species additional work is required on their basic ecology, in particular germination biology and site requirements, as part of a restoration project. The overall low rate of establishment success emphasizes the need to protect and manage existing populations of uncommon Sandhills species, and to recognize that establishing large, long-term, reproducing populations of such species will be difficult.

  4. Suitability of Cryopreservation for the Long‐term Storage of Rare and Endangered Plant Species: a Case History for Cosmos atrosanguineus

    PubMed Central

    WILKINSON, TIM; WETTEN, ANDREW; PRYCHID, CHRISSIE; FAY, MICHAEL F.

    2003-01-01

    The suitability of cryopreservation for the secure, long‐term storage of the rare and endangered species Cosmos atrosanguineus was investigated. Using encapsulation/dehydration of shoot tips in alginate strips, survival rates of up to 100 % and shoot regeneration of up to 35 % were achieved. Light and electron microscopy studies indicated that cellular damage to some regions of the shoot tip during the freeze/thaw procedure was high, although cell survival in and around the meristematic region allowed shoot tip regeneration. The genetic fingerprinting technique, amplified fragment length polymorphisms (AFLPs), showed that no detectable genetic variation was present between material of C. atrosanguineus at the time of initiation into tissue culture and that which had been cryopreserved, stored in liquid nitrogen for 12 months and regenerated. Weaned plantlets that were grown under glasshouse conditions exhibited no morphological variation from non‐frozen controls. PMID:12495921

  5. Suitability of cryopreservation for the long-term storage of rare and endangered plant species: a case history for Cosmos atrosanguineus.

    PubMed

    Wilkinson, Tom; Wetten, Andrew; Prychid, Chrissie; Fay, Michael F

    2003-01-01

    The suitability of cryopreservation for the secure, long-term storage of the rare and endangered species Cosmos atrosanguineus was investigated. Using encapsulation/dehydration of shoot tips in alginate strips, survival rates of up to 100 % and shoot regeneration of up to 35 % were achieved. Light and electron microscopy studies indicated that cellular damage to some regions of the shoot tip during the freeze/thaw procedure was high, although cell survival in and around the meristematic region allowed shoot tip regeneration. The genetic fingerprinting technique, amplified fragment length polymorphisms (AFLPs), showed that no detectable genetic variation was present between material of C. atrosanguineus at the time of initiation into tissue culture and that which had been cryopreserved, stored in liquid nitrogen for 12 months and regenerated. Weaned plantlets that were grown under glasshouse conditions exhibited no morphological variation from non-frozen controls. Copyright 2003 Annals of Botany Company

  6. Evolution of larval host plant associations and adaptive radiation in pierid butterflies.

    PubMed

    Braby, M F; Trueman, J W H

    2006-09-01

    Butterflies in the family Pieridae (Lepidoptera: Papilionoidea) feed as larvae on plants belonging primarily to three distantly related angiosperm orders: Fabales (legumes and allied plants), Brassicales (crucifers and related plants containing mustard oil glucosides), and Santalales ('mistletoes'). However, some utilize plants from 13 other families in a further eight orders. We investigated the evolutionary history of host plant use of the Pieridae in the context of a recent phylogenetic hypothesis of the family, using simple character optimization. Although there is a close association between host plant and butterfly higher classification, we find no evidence for cospeciation but a pattern of repeated colonization and specialization. The ancestral host of the family appears to be Fabaceae or Fabales, with multiple independent shifts to other orders, including three to Santalales. The shift to Brassicales, which contain secondary compounds (glucosinolates), promoted diversification and adaptive radiation within the subfamily Pierinae. Subsequent shifts from crucifers to mistletoes (aerial-stem hemiparasites) facilitated further diversification, and more recent shifts from mistletoes to mistletoe host trees led to exploitation of novel host plants outside the conventional three orders. Possible mechanisms underlying these host shifts are briefly discussed. In the Pierinae, a striking association between host plant, larval and adult behaviour, adult phenotype, and mimicry calls for further research into possible relationships between host specialization, plant chemistry and butterfly palatability.

  7. Promoting role of an endophyte on the growth and contents of kinsenosides and flavonoids of Anoectochilus formosanus Hayata, a rare and threatened medicinal Orchidaceae plant*

    PubMed Central

    Zhang, Fu-sheng; Lv, Ya-li; Zhao, Yue; Guo, Shun-xing

    2013-01-01

    Anoectochilus formosanus, commonly known as “Jewel Orchid”, is a Chinese folk medicine used to treat hypertension, diabetes, and heart disease. The existence of A. formosanus is currently threatened by habitat loss, human and animal consumption, etc. The highly potent medicinal activity of A. formosanus is due to its secondary metabolites, especially kinsenosides and flavonoids. This orchid also has a unique mycorrhizal relationship. Most adult orchids rely on endophytes for mineral nutrition and have complex interactions with them, which are related to plant growth, yield and changes in secondary metabolites. This study investigated the promoting role of F-23 fungus (genus Mycena) on the biomass and contents of kinsenosides and flavonoids of A. formosanus in pot culture. The following were observed after 10 weeks of symbiotic cultivation: increased shoot height, shoot dry weight, and leaf numbers by 16.6%, 31.3%, and 22.5%, respectively; increased contents of kinsenosides, isorhamnetin-3-O-β-D-rutinoside, and isorhamnetin-3-O-β-D-glucopyranoside by 85.5%, 226.1%, and 196.0%, respectively; some hyphae in epidermal cells dyed red and/or reddish brown by safranine; and, significantly reduced number of starch grains in cortical cells. Moreover, F-23 fungus significantly improved the kinsenoside and flavonoid contents of A. formosanus. These findings supported the reports that endophytes can alter the production of secondary metabolites in their plant hosts, although further physiological, genetic and ecological analyses are warranted. PMID:24009198

  8. Promoting role of an endophyte on the growth and contents of kinsenosides and flavonoids of Anoectochilus formosanus Hayata, a rare and threatened medicinal Orchidaceae plant.

    PubMed

    Zhang, Fu-sheng; Lv, Ya-li; Zhao, Yue; Guo, Shun-xing

    2013-09-01

    Anoectochilus formosanus, commonly known as "Jewel Orchid", is a Chinese folk medicine used to treat hypertension, diabetes, and heart disease. The existence of A. formosanus is currently threatened by habitat loss, human and animal consumption, etc. The highly potent medicinal activity of A. formosanus is due to its secondary metabolites, especially kinsenosides and flavonoids. This orchid also has a unique mycorrhizal relationship. Most adult orchids rely on endophytes for mineral nutrition and have complex interactions with them, which are related to plant growth, yield and changes in secondary metabolites. This study investigated the promoting role of F-23 fungus (genus Mycena) on the biomass and contents of kinsenosides and flavonoids of A. formosanus in pot culture. The following were observed after 10 weeks of symbiotic cultivation: increased shoot height, shoot dry weight, and leaf numbers by 16.6%, 31.3%, and 22.5%, respectively; increased contents of kinsenosides, isorhamnetin-3-O-β-D-rutinoside, and isorhamnetin-3-O-β-D-glucopyranoside by 85.5%, 226.1%, and 196.0%, respectively; some hyphae in epidermal cells dyed red and/or reddish brown by safranine; and, significantly reduced number of starch grains in cortical cells. Moreover, F-23 fungus significantly improved the kinsenoside and flavonoid contents of A. formosanus. These findings supported the reports that endophytes can alter the production of secondary metabolites in their plant hosts, although further physiological, genetic and ecological analyses are warranted.

  9. Rare species occupy uncommon niches

    NASA Astrophysics Data System (ADS)

    Markham, John

    2014-08-01

    The fact that temperate grasslands often contain upwards of 30 vascular plant species per m2 yet these species seem to have relatively similar life histories and resource requirements has made explaining species coexistence in these communities a major focus of research. While the reduction of competition by disturbance has been a popular explanation for species coexistence, in tallgrass prairies any level of disturbance either has no effect, or decreases diversity, since it favors the dominant plants. Although there has long been speculation that grassland species could coexist by niche partitioning the concept received renewed interest when it was shown that soil hydrology could explain species coexistence. One aspect of community structure that has not been explained by niche partitioning is the rareness and commonness of species within communities. There are three classes of explanations for rareness: narrow habitat requirements, low competitive ability combined with frequency dependent fitness and, dispersal ability. However, evidence for these explanations tend to be anecdotal, focusing on particular species. Here I show that in tallgrass prairies common and rare species consistently occupy different parts of niche space, with rare species being restricted by the cover of common species and occupying the rare available niches.

  10. Rare species occupy uncommon niches

    PubMed Central

    Markham, John

    2014-01-01

    The fact that temperate grasslands often contain upwards of 30 vascular plant species per m2 yet these species seem to have relatively similar life histories and resource requirements has made explaining species coexistence in these communities a major focus of research. While the reduction of competition by disturbance has been a popular explanation for species coexistence, in tallgrass prairies any level of disturbance either has no effect, or decreases diversity, since it favors the dominant plants. Although there has long been speculation that grassland species could coexist by niche partitioning the concept received renewed interest when it was shown that soil hydrology could explain species coexistence. One aspect of community structure that has not been explained by niche partitioning is the rareness and commonness of species within communities. There are three classes of explanations for rareness: narrow habitat requirements, low competitive ability combined with frequency dependent fitness and, dispersal ability. However, evidence for these explanations tend to be anecdotal, focusing on particular species. Here I show that in tallgrass prairies common and rare species consistently occupy different parts of niche space, with rare species being restricted by the cover of common species and occupying the rare available niches. PMID:25110113

  11. Rare arctic-alpine plants of the European Alps have different immigration histories: the snow bed species Minuartia biflora and Ranunculus pygmaeus.

    PubMed

    Schönswetter, P; Popp, M; Brochmann, C

    2006-03-01

    Minuartia biflora and Ranunculus pygmaeus are circumarctic plants with a few isolated occurrences in the European Alps. We analysed amplified fragment length polymorphism (AFLP) and chloroplast DNA sequence data to unravel the history of their immigration into the Alps and to provide data on their circumpolar phylogeography. In spite of the similar ecological requirements of the two species, they exhibit strikingly different immigration histories into the Alps. In M. biflora, the Alpine populations are most probably derived from source populations located between the Alpine and Scandinavian ice sheets, in accordance with the traditional biogeographic hypothesis. In contrast, the Alpine populations of R. pygmaeus cluster with those from the Tatra Mountains and the Taymyr region in northern Siberia, indicating that the distant Taymyr area served as source for the Alpine populations. Both species showed different levels of genetic diversity in formerly glaciated areas. In contrast to the considerable AFLP diversity observed in M. biflora, R. pygmaeus was virtually nonvariable over vast areas, with a single phenotype dominating all over the Alps and another, distantly related one dominating the North Atlantic area from Greenland over Svalbard to Scandinavia. The same pattern was observed in chloroplast DNA sequence data. Thus, postglacial colonization of R. pygmaeus was accompanied by extreme founder events.

  12. Simple additive effects are rare: a quantitative review of plant biomass and soil process responses to combined manipulations of CO2 and temperature.

    PubMed

    Dieleman, Wouter I J; Vicca, Sara; Dijkstra, Feike A; Hagedorn, Frank; Hovenden, Mark J; Larsen, Klaus S; Morgan, Jack A; Volder, Astrid; Beier, Claus; Dukes, Jeffrey S; King, John; Leuzinger, Sebastian; Linder, Sune; Luo, Yiqi; Oren, Ram; De Angelis, Paolo; Tingey, David; Hoosbeek, Marcel R; Janssens, Ivan A

    2012-09-01

    In recent years, increased awareness of the potential interactions between rising atmospheric CO2 concentrations ([ CO2 ]) and temperature has illustrated the importance of multifactorial ecosystem manipulation experiments for validating Earth System models. To address the urgent need for increased understanding of responses in multifactorial experiments, this article synthesizes how ecosystem productivity and soil processes respond to combined warming and [ CO2 ] manipulation, and compares it with those obtained in single factor [ CO2 ] and temperature manipulation experiments. Across all combined elevated [ CO2 ] and warming experiments, biomass production and soil respiration were typically enhanced. Responses to the combined treatment were more similar to those in the [ CO2 ]-only treatment than to those in the warming-only treatment. In contrast to warming-only experiments, both the combined and the [ CO2 ]-only treatments elicited larger stimulation of fine root biomass than of aboveground biomass, consistently stimulated soil respiration, and decreased foliar nitrogen (N) concentration. Nonetheless, mineral N availability declined less in the combined treatment than in the [ CO2 ]-only treatment, possibly due to the warming-induced acceleration of decomposition, implying that progressive nitrogen limitation (PNL) may not occur as commonly as anticipated from single factor [ CO2 ] treatment studies. Responses of total plant biomass, especially of aboveground biomass, revealed antagonistic interactions between elevated [ CO2 ] and warming, i.e. the response to the combined treatment was usually less-than-additive. This implies that productivity projections might be overestimated when models are parameterized based on single factor responses. Our results highlight the need for more (and especially more long-term) multifactor manipulation experiments. Because single factor CO2 responses often dominated over warming responses in the combined treatments, our

  13. Is the extremely rare Iberian endemic plant species Castrilanthemum debeauxii (Compositae, Anthemideae) a 'living fossil'? Evidence from a multi-locus species tree reconstruction.

    PubMed

    Tomasello, Salvatore; Álvarez, Inés; Vargas, Pablo; Oberprieler, Christoph

    2015-01-01

    The present study provides results of multi-species coalescent species tree analyses of DNA sequences sampled from multiple nuclear and plastid regions to infer the phylogenetic relationships among the members of the subtribe Leucanthemopsidinae (Compositae, Anthemideae), to which besides the annual Castrilanthemum debeauxii (Degen, Hervier & É.Rev.) Vogt & Oberp., one of the rarest flowering plant species of the Iberian Peninsula, two other unispecific genera (Hymenostemma, Prolongoa), and the polyploidy complex of the genus Leucanthemopsis belong. Based on sequence information from two single- to low-copy nuclear regions (C16, D35, characterised by Chapman et al. (2007)), the multi-copy region of the nrDNA internal transcribed spacer regions ITS1 and ITS2, and two intergenic spacer regions of the cpDNA gene trees were reconstructed using Bayesian inference methods. For the reconstruction of a multi-locus species tree we applied three different methods: (a) analysis of concatenated sequences using Bayesian inference (MrBayes), (b) a tree reconciliation approach by minimizing the number of deep coalescences (PhyloNet), and (c) a coalescent-based species-tree method in a Bayesian framework ((∗)BEAST). All three species tree reconstruction methods unequivocally support the close relationship of the subtribe with the hitherto unclassified genus Phalacrocarpum, the sister-group relationship of Castrilanthemum with the three remaining genera of the subtribe, and the further sister-group relationship of the clade of Hymenostemma+Prolongoa with a monophyletic genus Leucanthemopsis. Dating of the (∗)BEAST phylogeny supports the long-lasting (Early Miocene, 15-22Ma) taxonomical independence and the switch from the plesiomorphic perennial to the apomorphic annual life-form assumed for the Castrilanthemum lineage that may have occurred not earlier than in the Pliocene (3Ma) when the establishment of a Mediterranean climate with summer droughts triggered evolution towards

  14. Chemical traits of hemiparasitism in Odontites luteus.

    PubMed

    Venditti, Alessandro; Frezza, Claudio; Foddai, Sebastiano; Serafini, Mauro; Nicoletti, Marcello; Bianco, Armandodoriano

    2016-12-20

    The study of the monoterpene glycosides content of Odontites luteus has shown the presence of a total of fifteen iridoid glucosides. The presence of compounds (1-5) and (7-10) is perfectly on-line with both the biogenetic pathway for iridoids biosynthesis in Lamiales and the current botanical classification of the species. On the other side, the presence of compounds like agnuside (6), adoxosidic acid (11), monotropein (12), 6,7-dihydromonotropein (13), methyl oleoside (14) and methyl gluco-oleoside (15) is of high interest because, first of all, they have never been reported before in Lamiales. In second instance, the majority of the last compounds are formally derived from a different biogenetic pathway which involves desoxyloganic acid/loganin and led to the formation of decarboxylated iridoid showing the 8β-stereochemistry. Furthermore, a second abnormality was found during our study and this regards compounds (14) and (15) which are seco-iriodids and thus not typical for this family. The presence of these unusual compounds, biogenetically not related to species belonging to Lamiales, is a clear evidence of the metabolites transfer from the hosts. In fact, the collection area is also populated by species belonging to Oleaceae and Ericaceae which could be the possible hosts since the biosynthesis of seco-iridoids and or iridoids related to deoxyloganic acid/loganin pathway, with the 8β-stereochemistry, is well documented in these species. This article is protected by copyright. All rights reserved.

  15. Messages from the Other Side: Parasites Receive Damage Cues from their Host Plants.

    PubMed

    Tjiurutue, Muvari Connie; Stevenson, Philip C; Adler, Lynn S

    2016-08-01

    As sessile organisms, plants rely on their environment for cues indicating imminent herbivory. These cues can originate from tissues on the same plant or from different individuals. Since parasitic plants form vascular connections with their host, parasites have the potential to receive cues from hosts that allow them to adjust defenses against future herbivory. However, the role of plant communication between hosts and parasites for herbivore defense remains poorly investigated. Here, we examined the effects of damage to lupine hosts (Lupinus texensis) on responses of the attached hemiparasite (Castilleja indivisa), and indirectly, on a specialist herbivore of the parasite, buckeyes (Junonia coenia). Lupines produce alkaloids that act as defenses against herbivores that can be taken up by the parasite. We found that damage to lupine host plants by beet armyworm (Spodoptera exigua) significantly increased jasmonic acid (JA) levels in both the lupine host and parasite, suggesting uptake of phytohormones or priming of parasite defenses by using host cues. However, lupine host damage did not induce changes in alkaloid levels in the hosts or parasites. Interestingly, the parasite had substantially higher concentrations of JA and alkaloids compared to lupine host plants. Buckeye herbivores consumed more parasite tissue when attached to damaged compared to undamaged hosts. We hypothesize that increased JA due to lupine host damage induced higher iridoid glycosides in the parasite, which are feeding stimulants for this specialist herbivore. Our results demonstrate that damage to hosts may affect both parasites and associated herbivores, indicating cascading effects of host damage on multiple trophic levels.

  16. Surface Disturbance Analysis in Rare Earth Mining

    NASA Astrophysics Data System (ADS)

    Li, H. K.; Yang, L.; Liu, Z. W.

    2017-02-01

    Mining ion-type rare-earth ore made the landscape and ecological environment degraded in mining area, and the tailing produced by rare-earth mining also led large areas land desertification, which resulted in surface temperature variations and significant differences in other types of mining disturbances. In order to analyse surface disturbance of rare-earth mining area, this paper applied the methods based on Normalized Difference Vegetation Index (NDVI) and Temperature different Coefficient (TDC) as the ecological disturbance indicator, compared and validated their applicability in Lingbei rare-earth mining area of Southern China. The results illustrated that, compared to NDVI, the TDC which reflected the characteristic of rare-earth mining technology has better discrimination of disturbance, especially for in-situ leach mining area. The places of tailing and the in-situ leach mining plants were the most dramatic mining disturbance. They had the biggest TDC value, followed by orchards and farmlands, reclamation plants, they had relatively small disturbance. And the last was the plant with the smallest TDC value. TDC in rare-earth mining could better correspond to the level of surface ecological disturbance. Therefore, TDC as the indicator of ecological disturbance factor had better performance than NDVI in rare-earth mining area.

  17. Rare Disorders and Diseases

    ERIC Educational Resources Information Center

    Umlauf, Mary; Monaco, Jana; FitzZaland, Mary; FitzZaland, Richard; Novitsky, Scott

    2008-01-01

    According to the National Organization for Rare Disorders (NORD), a rare or "orphan" disease affects fewer than 200,000 people in the United States. There are more than 6,000 rare disorders that, taken together, affect approximately 25 million Americans. "Exceptional Parent" ("EP") recognizes that when a disorder affects a child or adult, it…

  18. Rare Disorders and Diseases

    ERIC Educational Resources Information Center

    Umlauf, Mary; Monaco, Jana; FitzZaland, Mary; FitzZaland, Richard; Novitsky, Scott

    2008-01-01

    According to the National Organization for Rare Disorders (NORD), a rare or "orphan" disease affects fewer than 200,000 people in the United States. There are more than 6,000 rare disorders that, taken together, affect approximately 25 million Americans. "Exceptional Parent" ("EP") recognizes that when a disorder affects a child or adult, it…

  19. Forecasting climate change impacts to plant community composition in the Sonoran Desert region

    USGS Publications Warehouse

    Munson, Seth M.; Webb, Robert H.; Belnap, Jayne; Hubbard, J. Andrew; Swann, Don E.; Rutman, Sue

    2012-01-01

    Hotter and drier conditions projected for the southwestern United States can have a large impact on the abundance and composition of long-lived desert plant species. We used long-term vegetation monitoring results from 39 large plots across four protected sites in the Sonoran Desert region to determine how plant species have responded to past climate variability. This cross-site analysis identified the plant species and functional types susceptible to climate change, the magnitude of their responses, and potential climate thresholds. In the relatively mesic mesquite savanna communities, perennial grasses declined with a decrease in annual precipitation, cacti increased, and there was a reversal of the Prosopis velutina expansion experienced in the 20th century in response to increasing mean annual temperature (MAT). In the more xeric Arizona Upland communities, the dominant leguminous tree, Cercidium microphyllum, declined on hillslopes, and the shrub Fouquieria splendens decreased, especially on south- and west-facing slopes in response to increasing MAT. In the most xeric shrublands, the codominant species Larrea tridentata and its hemiparasite Krameria grayi decreased with a decrease in cool season precipitation and increased aridity, respectively. This regional-scale assessment of plant species response to recent climate variability is critical for forecasting future shifts in plant community composition, structure, and productivity.

  20. Rare earth lasers

    SciTech Connect

    Weber, M.J.

    1985-01-01

    In this brief survey, some of the key spectroscopic properties of rare earths are reviewed that account for their versatility, examine recent research trends and developments, and comment upon future projects for rare earth lasers. For gaseous and liquid lasers, other elements and molecules have thus far demonstrated lasing properties more attractive than those available using rare earths. Therefore, remarks shall be limited to solid state lasers.

  1. Inventory of Rare of Endangered Vascular Plants Occurring in the Floodplain of the Mississippi River between Cairo, Illinois, and St. Paul, Minnesota, and in the Floodplain of the Illinois River between Grafton, Illinois, and Chicago,

    DTIC Science & Technology

    1975-01-01

    disturbed areas. It flowers from May to August. -:. :i5 1 53 Sesbania exaltata (Raf.) Cory Sesbania Family Leguminosae Status: Rare (Illinois). This is... Leguminosae Statuae Rare (T11inois). UttJt ts recent discovery in 1974 in a sandy prairie near Lock- pot, n .Will County, along the Illinois and Michigan

  2. Rare Parotid Gland Diseases.

    PubMed

    Sanan, Akshay; Cognetti, David M

    2016-04-01

    The differential diagnosis for "rare" parotid gland diseases is broad and encompasses infectious, neoplastic, autoimmune, metabolic, and iatrogenic etiologies. The body of knowledge of parotid gland diseases has grown owing to advances in imaging and pathologic analysis and molecular technology. This article reviews rare parotid diseases, discussing the respective disease's clinical presentation, diagnosis, imaging, pathogenesis, treatment, and prognosis.

  3. Is schizophrenia rare if grain is rare?

    PubMed

    Dohan, F C; Harper, E H; Clark, M H; Rodrigue, R B; Zigas, V

    1984-03-01

    If, as hypothesized, neuroactive peptides from grain glutens are the major agents evoking schizophrenia in those with the genotype(s), it should be rare if grain is rare. To test this, we analyzed the results of our clinical examinations (e.g., kuru) and observations of anthropologists on peoples consuming little or no grain. Only two overtly insane chronic schizophrenics were found among over 65,000 examined or closely observed adults in remote regions of Papua New Guinea (PNG, 1950-1967) and Malaita , Solomon Islands (1980-1981), and on Yap , Micronesia (1947-1948). In preneuroleptic Europe over 130 would have been expected. When these peoples became partially westernized and consumed wheat, barley beer, and rice, the prevalence reached European levels. Our findings agree with previous epidemiologic and experimental results indicating that grain glutens are harmful to schizophrenics.

  4. Rare cancers: Challenges & issues.

    PubMed

    Pillai, Raveendran K; Jayasree, K

    2017-01-01

    Rare cancers account for about 22 per cent of all cancers diagnosed worldwide, disproportionately affecting some demographic groups, with an occurrence of less than 6 per 100,000 individuals annually. Many rare cancers in adults, adolescents and children are not curable, and patients and care providers have little option to take therapeutic decisions. The epidemiology of rare cancers is a challenging area of study but is inadequately addressed. Despite efforts mainly in some European nations, a few improvements have been observed in the management of rare cancers. Reasons for this obvious stagnation are multifactorial and are mainly inherent to logistical difficulties in carrying out clinical trials in very small patient populations, hesitation of the pharmaceutical industry to spend in small markets and complexity in creating adequate information for the development of cost-effective drugs. Rare cancers also face specific challenges that include late and incorrect diagnosis, lack of clinical expertise and lack of research interest and development of new therapies. The utilization of nationally representative study findings for the patients' evaluation may possibly offer chances to find out pathogenesis and prevalence, and this will eventually lead to control and prevention. Currently, advancing targeted therapies offer a great opportunity for the better management of rare cancers. Conducting clinical trials with small patient population, innovative clinical trial approach, prevailing controlling obstacles for international cooperation and financial support for research are the present challenges for rare cancers. The International Rare Cancers Initiative functions as a main platform for achieving new international clinical trials in rare tumours. This review delineates the current challenges and issues in the interpretation, management and research scenarios of rare cancers.

  5. Why trees and shrubs but rarely trubs?

    PubMed

    Scheffer, Marten; Vergnon, Remi; Cornelissen, J Hans C; Hantson, Stijn; Holmgren, Milena; van Nes, Egbert H; Xu, Chi

    2014-08-01

    An analysis of the maximum height of woody plant species across the globe reveals that an intermediate size is remarkably rare. We speculate that this may be due to intrinsic suboptimality or to ecosystem bistability with open landscapes favouring shrubs, and closed canopies propelling trees to excessive tallness.

  6. Rare Diseases Research

    PubMed Central

    2013-01-01

    Extensive public-private partnerships, including the National Institutes of Health (NIH) and the rare diseases community, which is seeing a renewed industry interest in smaller niche markets, have resulted in an increase of interventions for rare diseases. Significant collaborative efforts are required among the pharmaceutical industry, foundations, patient-advocacy groups, academic and government investigators and funding programs, regulatory scientists, and reimbursement agencies to meet the unmet diagnostic and treatment needs for approximately 25 million people in the United States with 7,000 rare diseases. The expanding role and outreach activities of patient-advocacy groups have increased public awareness. In the United States, a rare disease is defined as a disorder or condition with a prevalence of < 200,000 people. In 2011, the NIH provided > $3.5 billion for rare diseases research, including $750 million for orphan product development activities, nearly 11.4% of the NIH research budget. Several research institutes and centers of the NIH, including the National Center for Advancing Translational Sciences, have initiated varied translational research efforts to address the absence of preclinical and clinical data required for regulatory review purposes. Clinicians can expect to see significant increases in requests from patients and their families to participate in patient registries and natural history or observational studies to gather specific information from a larger pool of patients on the progression of the disease or response to treatments. An expanding emphasis on rare diseases provides hope for the millions of patients with rare diseases. PMID:23880676

  7. Distributions of rare earths and heavy metals in field-grown maize after application of rare earth-containing fertilizer.

    PubMed

    Xu, Xingkai; Zhu, Wangzhao; Wang, Zijian; Witkamp, Geert-Jan

    2002-07-03

    Rare earths are widely applied in Chinese agriculture to improve crop nutrition through the use of fertilizers, yet little is known of their accumulation in field-grown crops. We have studied the distribution of 16 rare earths (Sc, Y and 14 lanthanide elements) in field-grown maize and the concentration of heavy metals in the grains after application of rare earth-containing fertilizer. When maize entered the vigorous vegetation growth stage (e.g. early stem-elongation stage), rare earth-containing fertilizer was applied to the soil with irrigation water. At 10 days after application of the rare earths, significantly dose-dependent accumulative effects of individual rare earth concentrations in the roots and the plant tops of maize were observed, with the exception of Sc and Lu. At the level of 2 kg rare earths ha(-1), accumulative concentrations of most light rare earths (e.g. La, Ce, Pr and Nd) and Gd in the plant tops were much larger than those in the control. Concentrations of individual rare earths in a field-grown maize after application of rare earths decreased in the order of root>leaf>stem>grain. During the maize growth period, selective accumulation of individual rare earths (e.g. La, Ce) in the roots seemed to be in dynamic equilibrium, and the distribution of these elements in the plant tops was variable. At a dosage of less than 10 kg rare earths ha(-1), no apparent accumulative concentrations of individual rare earths appeared in the maize grains. Under the experimental conditions, application of rare earth-containing fertilizer did not induce an increase in the concentrations of heavy metals in the grains. We conclude that the present dosage of rare earths (<0.23 kg ha(-1) year(-1)) currently applied in China can hardly affect the safety of maize grains in arable soil, even over a long period.

  8. A rare opportunity beckons

    SciTech Connect

    Gschneidner, K

    2011-02-01

    There is a great deal of uncertainty for the future of rare-earth production. Rare-earths are a collection of 17 chemical elements in the periodic table, which include scandium and yttrium as well as the 15 lanthanides, such as dysprosium and ytterbium. China has a stranglehold on today's rare-earth market, which was worth about $3bn in 2010, with the country accounting for about 95% of worldwide production. Yet China's future actions can only be guessed at best. In September it halted shipments of rare-earth elements to Japan over a diplomatic spat concerning the detention of a Chinese trawler captain. Although the ban was later lifted, the episode raised concerns around the world about China's rare-earth monopoly and its use in diplomacy. China has already warned that it will not export any rare-earth material in the coming years as it expects its own consumption of rare-earth metals to increase. The country has introduced export taxes as well as production and export quotas, and also refused to grant any new rare-earth mining licences. Furthermore, because its reserves are limited and China's internal markets are growing so rapidly, the country has suggested it will no longer export products that require rare-earth elements, especially those that need heavy rare-earth elements, such as terbium and dysprosium. China's actions have led to huge rises in the cost of rare-earth materials and products. Dysprosium oxide, for example, has shot up from $36 per kilogram in 2005 to a massive $305 per kilogram by late last year. This could have a huge impact on much of today's electronics industry, given that rare-earth elements are ubiquitous in electric motors, computers, batteries, liquid-crystal displays (LCDs) and mobile phones. Neodymium-iron-boron permanent magnets, for example, are used as computer spindle drives. The question is: what can be done to ensure that China's dominance of the rare-earth industry does not affect the military and energy security of the US

  9. Rare earth gas laser

    DOEpatents

    Krupke, W.F.

    1975-10-31

    A high energy gas laser with light output in the infrared or visible region of the spectrum is described. Laser action is obtained by generating vapors of rare earth halides, particularly neodymium iodide or, to a lesser extent, neodymium bromide, and disposing the rare earth vapor medium in a resonant cavity at elevated temperatures; e.g., approximately 1200/sup 0/ to 1400/sup 0/K. A particularly preferred gaseous medium is one involving a complex of aluminum chloride and neodymium chloride, which exhibits tremendously enhanced vapor pressure compared to the rare earth halides per se, and provides comparable increases in stored energy densities.

  10. Medical rare book provenance.

    PubMed Central

    Overmier, J A; Sentz, L

    1987-01-01

    Provenance is defined as the record of a book's ownership history. Its value and uses are explored. A survey of provenance practices in medical school rare book libraries found that only 21% of the reporting libraries maintain this important file. Examples of the uses and value of a provenance file in a medical rare book collection are presented. Decisions necessary to institute and maintain such a file are outlined and discussed. PMID:3828606

  11. Striga parasitizes transgenic hairy roots of Zea mays and provides a tool for studying plant-plant interactions

    PubMed Central

    2012-01-01

    Background Striga species are noxious root hemi-parasitic weeds that debilitate cereal production in sub-Saharan Africa (SSA). Control options for Striga are limited and developing Striga resistant crop germplasm is regarded as the best and most sustainable control measure. Efforts to improve germplasm for Striga resistance by a non-Genetic Modification (GM) approach, for example by exploiting natural resistance, or by a GM approach are constrained by limited information on the biological processes underpinning host-parasite associations. Additionaly, a GM approach is stymied by lack of availability of candidate resistance genes for introduction into hosts and robust transformation methods to validate gene functions. Indeed, a majority of Striga hosts, the world’s most cultivated cereals, are recalcitrant to genetic transformation. In maize, the existing protocols for transformation and regeneration are tedious, lengthy, and highly genotype-specific with low efficiency of transformation. Results We used Agrobacterium rhizogenes strain K599 carrying a reporter gene construct, Green Fluorescent Protein (GFP), to generate transgenic composite maize plants that were challenged with the parasitic plant Striga hermonthica. Eighty five percent of maize plants produced transgenic hairy roots expressing GFP. Consistent with most hairy roots produced in other species, transformed maize roots exhibited a hairy root phenotype, the hallmark of A. rhizogenes mediated transformation. Transgenic hairy roots resulting from A. rhizogenes transformation were readily infected by S. hermonthica. There were no significant differences in the number and size of S. hermonthica individuals recovered from either transgenic or wild type roots. Conclusions This rapid, high throughput, transformation technique will advance our understanding of gene function in parasitic plant-host interactions. PMID:22720750

  12. Striga parasitizes transgenic hairy roots of Zea mays and provides a tool for studying plant-plant interactions.

    PubMed

    Runo, Steven; Macharia, Sarah; Alakonya, Amos; Machuka, Jesse; Sinha, Neelima; Scholes, Julie

    2012-06-21

    Striga species are noxious root hemi-parasitic weeds that debilitate cereal production in sub-Saharan Africa (SSA). Control options for Striga are limited and developing Striga resistant crop germplasm is regarded as the best and most sustainable control measure. Efforts to improve germplasm for Striga resistance by a non-Genetic Modification (GM) approach, for example by exploiting natural resistance, or by a GM approach are constrained by limited information on the biological processes underpinning host-parasite associations. Additionaly, a GM approach is stymied by lack of availability of candidate resistance genes for introduction into hosts and robust transformation methods to validate gene functions. Indeed, a majority of Striga hosts, the world's most cultivated cereals, are recalcitrant to genetic transformation. In maize, the existing protocols for transformation and regeneration are tedious, lengthy, and highly genotype-specific with low efficiency of transformation. We used Agrobacterium rhizogenes strain K599 carrying a reporter gene construct, Green Fluorescent Protein (GFP), to generate transgenic composite maize plants that were challenged with the parasitic plant Striga hermonthica. Eighty five percent of maize plants produced transgenic hairy roots expressing GFP. Consistent with most hairy roots produced in other species, transformed maize roots exhibited a hairy root phenotype, the hallmark of A. rhizogenes mediated transformation. Transgenic hairy roots resulting from A. rhizogenes transformation were readily infected by S. hermonthica. There were no significant differences in the number and size of S. hermonthica individuals recovered from either transgenic or wild type roots. This rapid, high throughput, transformation technique will advance our understanding of gene function in parasitic plant-host interactions.

  13. How rare are diffusive rare events?

    NASA Astrophysics Data System (ADS)

    Sanders, D. P.; Larralde, H.

    2008-05-01

    We study the time until first occurrence, the first-passage time, of rare density fluctuations in diffusive systems. We approach the problem using a model consisting of many independent random walkers on a lattice. The existence of spatial correlations makes this problem analytically intractable. However, for a mean-field approximation in which the walkers can jump anywhere in the system, we obtain a simple asymptotic form for the mean first-passage time to have a given number k of particles at a distinguished site. We show numerically, and argue heuristically, that for large enough k, the mean-field results give a good approximation for first-passage times for systems with nearest-neighbour dynamics, especially for two and higher spatial dimensions. Finally, we show how the results change when density fluctuations anywhere in the system, rather than at a specific distinguished site, are considered.

  14. A rare splenic pseudocyst

    PubMed Central

    Verma, Ankit; Yadav, Amit; Sharma, Sourabh; Saini, Devender; Om, Prabha; Khoja, Hanuman; Banerjee, Kinjal; NL, Harish

    2013-01-01

    Pseudocysts of the spleen are very rare, found in <1% of the splenectomies done and usually develop secondary to trauma. Pseudocysts of spleen rarely grow to large size and most of these remain asymptomatic, they require exploration only in symptomatic cases and chances for spleen preservation in these cases are usually less. Here, we present two cases of this rare entity developing secondary to abdominal trauma in the past, both presented with complaints of pain and lump in the abdomen. After thorough investigations, laparotomy was done preserving spleen in one case and doing splenectomy in the other. On histopathological examination, diagnosis of splenic pseudocysts was confirmed by the absence of lining epithelium. We would like to report these two cases because of their rarity and as diagnostic dilemmas. PMID:24963908

  15. Inventory of Rare or Endangered Non-Vascular Plants and Ferns Occurring in the Floodplain of the Mississippi River between Cairo, Illinois, and St. Paul, Minnesota, and in the Floodplain of the Illinois River between Grafton, Illinois, and Chicago,

    DTIC Science & Technology

    1975-02-03

    3 Liverworts and Horworts ------------------ 4 Lichens -------------------------------- 4 Ferns ------------------------------- 5 Algae of the...Mississippi River and Illinois River Floodplains ----- 6 Mosses of the Mississippi River and Illinois River Floodplains--- 35 Liverworts and Hornworts...any alga, hornwort, liverwort , moss, or lichen in the study area. Missouri (1974) lists some mosses which are designated 0 rare or endangered, but

  16. Endangered Species: Wild & Rare.

    ERIC Educational Resources Information Center

    Braus, Judy, Ed.

    1987-01-01

    Ranger Rick's NatureScope is a creative education series dedicated to inspiring in children an understanding and appreciation of the natural world while developing the skills they will need to make responsible decisions about the environment. The topic of this issue is "Endangered Species: Wild and Rare." Contents are organized into the…

  17. Rare Jejunal Diverticular Bleeding

    PubMed Central

    Christman, Emily; Hassell, Lewis A.; Kastens, Donald

    2016-01-01

    Severe gastrointestinal bleeding (GIB) secondary to jejunal diverticulosis (JD) is very rare. Delay in establishing a diagnosis is common and GIB from JD is associated with significant morbidity and mortality. We report an illustrative case diagnosed by push enteroscopy and managed with surgery. PMID:27800518

  18. A Rare Opportunity.

    ERIC Educational Resources Information Center

    Bennett, Dean B.

    1986-01-01

    Reviews programs in the state of Maine that are designed to inventory the natural heritage of critical areas, rare species, and exemplary natural features. Discusses how the information acquired by these programs is being used for public information efforts and educational programs in the schools. (ML)

  19. Endangered Species: Wild & Rare.

    ERIC Educational Resources Information Center

    Braus, Judy, Ed.

    1987-01-01

    Ranger Rick's NatureScope is a creative education series dedicated to inspiring in children an understanding and appreciation of the natural world while developing the skills they will need to make responsible decisions about the environment. The topic of this issue is "Endangered Species: Wild and Rare." Contents are organized into the…

  20. Rare earth thermoelectrics

    SciTech Connect

    Mahan, G.D.

    1997-09-01

    The author reviews the thermoelectric properties of metallic compounds which contain rare-earth atoms. They are the group of metals with the largest value ever reported of the Seebeck coefficient. An increase by 50% of the Seebeck would make these compounds useful for thermoelectric devices. The largest Seebeck coefficient is found for compounds of cerium (e.g., CePd{sub 3}) and ytterbium (e.g., YbAl{sub 3}). Theoretical predictions are in agreement with the maximum observed Seebeck. The author discusses the theoretical model which has been used to calculate the Seebeck coefficient. He is solving this model for other configurations (4f){sup n} of rare-earth ground states.

  1. Rare causes of osteoporosis

    PubMed Central

    Marcucci, Gemma; Brandi, Maria Luisa

    2015-01-01

    Summary Osteoporosis is a metabolic bone disease characterized by loss of bone mass and strength, resulting in increased risk of fractures. It is classically divided into primary (post-menopausal or senile), secondary and idiopathic forms. There are many rare diseases, that cause directly or indirectly osteoporosis. The identification and classification of most of these rare causes of osteoporosis is crucial for the specialists in endocrinology and not, in order to prevent this bone complication and to provide for an early therapy. Several pathogenic mechanisms are involved, including various aspects of bone metabolism such as: decreased bone formation, increased bone resorption, altered calcium, phosphorus and/or vitamin D homeostasis, and abnormal collagen synthesis. In this review, less common forms of primary and secondary osteoporosis are described, specifying, if applicable: genetic causes, epidemiology, clinical features, and pathogenic mechanisms causing osteoporosis. A greater awareness of all rare causes of osteoporosis could reduce the number of cases classified as idiopathic osteoporosis and allow the introduction of appropriate and timely treatments. PMID:26604941

  2. Genetic variation changes the interactions between the parasitic plant-ecosystem engineer Rhinanthus and its hosts

    PubMed Central

    Rowntree, Jennifer K.; Cameron, Duncan D.; Preziosi, Richard F.

    2011-01-01

    Within-species genetic variation is a potent factor influencing between-species interactions and community-level structure. Species of the hemi-parasitic plant genus Rhinanthus act as ecosystem engineers, significantly altering above- and below-ground community structure in grasslands. Here, we show the importance of genotypic variation within a single host species (barley—Hordeum vulgare), and population-level variation among two species of parasite (Rhinanthus minor and Rhinanthus angustifolius) on the outcome of parasite infection for both partners. We measured host fitness (number of seeds) and calculated parasite virulence as the difference in seed set between infected and uninfected hosts (the inverse of host tolerance). Virulence was determined by genetic variation within the host species and among the parasite species, but R. angustifolius was consistently more virulent than R. minor. The most tolerant host had the lowest inherent fitness and did not gain a fitness advantage over other infected hosts. We measured parasite size as a proxy for transmission ability (ability to infect further hosts) and host resistance. Parasite size depended on the specific combination of host genotype, parasite species and parasite population, and no species was consistently larger. We demonstrate that the outcome of infection by Rhinanthus depends not only on the host species, but also on the underlying genetics of both host and parasite. Thus, genetic variations within host and parasite are probably essential components of the ecosystem-altering effects of Rhinanthus. PMID:21444312

  3. Genetic variation changes the interactions between the parasitic plant-ecosystem engineer Rhinanthus and its hosts.

    PubMed

    Rowntree, Jennifer K; Cameron, Duncan D; Preziosi, Richard F

    2011-05-12

    Within-species genetic variation is a potent factor influencing between-species interactions and community-level structure. Species of the hemi-parasitic plant genus Rhinanthus act as ecosystem engineers, significantly altering above- and below-ground community structure in grasslands. Here, we show the importance of genotypic variation within a single host species (barley-Hordeum vulgare), and population-level variation among two species of parasite (Rhinanthus minor and Rhinanthus angustifolius) on the outcome of parasite infection for both partners. We measured host fitness (number of seeds) and calculated parasite virulence as the difference in seed set between infected and uninfected hosts (the inverse of host tolerance). Virulence was determined by genetic variation within the host species and among the parasite species, but R. angustifolius was consistently more virulent than R. minor. The most tolerant host had the lowest inherent fitness and did not gain a fitness advantage over other infected hosts. We measured parasite size as a proxy for transmission ability (ability to infect further hosts) and host resistance. Parasite size depended on the specific combination of host genotype, parasite species and parasite population, and no species was consistently larger. We demonstrate that the outcome of infection by Rhinanthus depends not only on the host species, but also on the underlying genetics of both host and parasite. Thus, genetic variations within host and parasite are probably essential components of the ecosystem-altering effects of Rhinanthus.

  4. Ecology of plant volatiles: taking a plant community perspective.

    PubMed

    Pierik, Ronald; Ballaré, Carlos L; Dicke, Marcel

    2014-08-01

    Although plants are sessile organisms, they can modulate their phenotype so as to cope with environmental stresses such as herbivore attack and competition with neighbouring plants. Plant-produced volatile compounds mediate various aspects of plant defence. The emission of volatiles has costs and benefits. Research on the role of plant volatiles in defence has focused primarily on the responses of individual plants. However, in nature, plants rarely occur as isolated individuals but are members of plant communities where they compete for resources and exchange information with other plants. In this review, we address the effects of neighbouring plants on plant volatile-mediated defences. We will outline the various roles of volatile compounds in the interactions between plants and other organisms, address the mechanisms of plant neighbour perception in plant communities, and discuss how neighbour detection and volatile signalling are interconnected. Finally, we will outline the most urgent questions to be addressed in the future. © 2014 John Wiley & Sons Ltd.

  5. Rare Earth Polyoxometalates.

    PubMed

    Boskovic, Colette

    2017-09-05

    Longstanding and important applications make use of the chemical and physical properties of both rare earth metals and polyoxometalates of early transition metals. The catalytic, optical, and magnetic features of rare earth metal ions are well-known, as are the reversible multielectron redox and photoredox capabilities of polyoxomolybdates and polyoxotungstates. The combination of rare earth ions and polyoxometalates in discrete molecules and coordination polymers is of interest for the unique combination of chemical and physical properties that can arise. This Account surveys our efforts to synthesize and investigate compounds with rare earth ions and polyoxometalates (RE-POMs), sometimes with carboxylate-based organic coligands. Our general synthetic approach is "bottom-up", which affords well-defined nanoscale molecules, typically in crystalline form and amenable to single-crystal X-ray diffraction for structure determination. Our particular focus is on elucidation of the physical properties conferred by the different structural components with a view to ultimately being able to tune these properties chemically. For this purpose, we employ a variety of spectroscopic, magnetochemical, electrochemical, and scattering techniques in concert with theoretical modeling and computation. Studies of RE-POM single-molecule magnets (SMMs) have utilized magnetic susceptibility, inelastic neutron scattering, and ab initio calculations. These investigations have allowed characterization of the crystal field splitting of the rare earth(III) ions that is responsible for the SMM properties of slow magnetic relaxation and magnetization quantum tunneling. Such SMMs are promising for applications in quantum computing and molecular spintronics. Photophysical measurements of a family of hybrid RE-POMs with organic ligands have afforded insights into sensitization of Tb(III) and Eu(III) emission through both organic and polyoxometalate chromophores in the same molecule. Detailed

  6. Rare B Decays

    SciTech Connect

    Jackson, P.D.; /Victoria U.

    2006-02-24

    Recent results from Belle and BaBar on rare B decays involving flavor-changing neutral currents or purely leptonic final states are presented. Measurements of the CP asymmetries in B {yields} K*{gamma} and b {yields} s{gamma} are reported. Also reported are updated limits on B{sup +} {yields} K{sup +}{nu}{bar {nu}}, B{sup +} {yields} {tau}{sup +}{nu}, B{sup +} {yields} {mu}{sup +}{nu} and the recent measurement of B {yields} X{sub s}{ell}{sup +}{ell}{sup -}.

  7. [Rarely seen fractures].

    PubMed

    Subaşi, M; Kapukaya, A; Kesemenli, C; Coban, V

    2001-10-01

    Rarely seen fractures are presented in this study. One case was a calcaneal spur, 2 cases osteochondroma pedicule fractures and talus posteromedial tubercle fracture due to direct trauma. Calcaneal spur and osteochondromas were removed surgically and posteromedial tubercle was treated by short-leg cast immobilization. In conclusion, we think that fractures of osteochondroma and calcaneal spur may be treated by surgical removal which do not cause any functional disorders after this operation, but fractures like the talus posteromedial tubercle should be treated conservatively by short-leg immobilization in the early period.

  8. Predispersal seed predation is higher in a rare species than in its widespread sympatric congeners (Astragalus, Fabaceae).

    PubMed

    Combs, Julie K; Lambert, Amy M; Reichard, Sarah H

    2013-11-01

    Rare plants may be rare, in part, because they are more susceptible to damage by predispersal insect seed predators than widespread congeneric species; thus, seed predation may be an important determinant of plant rarity. Scant evidence exists to either support or reject this hypothesis, limiting our ability to predict herbivore effects on plant rarity. We used a comparative framework to test this hypothesis in rare-common, sympatric congeners. We compared seed consumption by insect type and seed production among a rare Astragalus (Fabaceae) species and two sympatric, widespread congeners. We measured plant traits and tested whether traits were correlated with seed damage within and among rare-common species. Seed predation was significantly higher in a rare species than in common congeners over 2 yr. Seed production per pod was significantly lower in the rare species. Seed weevils exclusively consumed seeds of the rare species. Higher seed predation in the rare species is related to a combination of factors: plant phenology, dispersal ability, and vigor; seed predator identity; and insect phenology. Our results support the hypothesis that a rare plant is more susceptible to seed predators than two common, sympatric congeners. Seed predator reduction is a promising management tool to increase seed-set, recruitment, and survival of the rare species. Further studies that compare rare-common, sympatric congeners are greatly needed to broadly evaluate the hypothesis concerning rarity and susceptibility to seed predators and to inform conservation plans for rare species.

  9. Ames Lab 101: Rare Earths

    ScienceCinema

    Gschneidner, Karl

    2016-07-12

    "Mr. Rare Earth," Ames Laboratory scientist Karl Gschneidner Jr., explains the importance of rare-earth materials in many of the technologies we use today -- ranging from computers to hybrid cars to wind turbines. Gschneidner is a world renowned rare-earths expert at the U.S. Department of Energy's Ames Laboratory.

  10. Ames Lab 101: Rare Earths

    SciTech Connect

    Gschneidner, Karl

    2010-01-01

    "Mr. Rare Earth," Ames Laboratory scientist Karl Gschneidner Jr., explains the importance of rare-earth materials in many of the technologies we use today -- ranging from computers to hybrid cars to wind turbines. Gschneidner is a world renowned rare-earths expert at the U.S. Department of Energy's Ames Laboratory.

  11. Analysis of endophytic fungi in roots of Santalum album Linn. and its host plant Kuhnia rosmarinifolia Vent.*

    PubMed Central

    Sun, Si-sheng; Chen, Xiao-mei; Guo, Shun-xing

    2014-01-01

    Santalum album Linn. is an evergreen and hemi-parasitic tree, the heartwood-sandalwood of which was used during a long history in traditional Chinese medicine. Kuhnia rosmarinifolia Vent. is a good host for 1- or 2-year-old growing S. album. The interaction between S. album and K. rosmarinifolia is still little known. Many studies have been carried out on a number of plants for identification and diversity of endophytes. In this study, in total 25 taxa of endophytic fungi were isolated from the roots of S. album and the roots of K. rosmarinifolia. The most frequently isolated genera were Penicillium sp. 1 and Fusarium sp. 1 in the roots of S. album and K. rosmarinifolia, respectively. S. album is a root parasite of K. rosmarinifolia. The interesting result is that they apparently do not share the same endophytic fungi isolates. This study for the first time explored the content of endophytic fungi from S. album and K. rosmarinifolia, which provides important information for further studies. PMID:24510703

  12. Rare times rare: The hyponatremia, rhabdomyolysis, anterior compartment syndrome sequence.

    PubMed

    Dubin, Ina; Gelber, Moshe; Schattner, Ami

    2016-05-01

    Primary polydipsia occurs in up to 25% of patients with chronic psychiatric disorders (especially schizophrenia), related to the disease, its treatment or both. Urine output fails to match intake >10 L/day and water intoxication may develop. Rhabdomyolysis is a rare complication of hyponatremia, and an acute anterior compartment syndrome of the leg, an emergency, may be very rarely associated.

  13. China's rare-earth industry

    USGS Publications Warehouse

    Tse, Pui-Kwan

    2011-01-01

    Introduction China's dominant position as the producer of over 95 percent of the world output of rare-earth minerals and rapid increases in the consumption of rare earths owing to the emergence of new clean-energy and defense-related technologies, combined with China's decisions to restrict exports of rare earths, have resulted in heightened concerns about the future availability of rare earths. As a result, industrial countries such as Japan, the United States, and countries of the European Union face tighter supplies and higher prices for rare earths. This paper briefly reviews China's rare-earth production, consumption, and reserves and the important policies and regulations regarding the production and trade of rare earths, including recently announced export quotas. The 15 lanthanide elements-lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, and lutetium (atomic numbers 57-71)-were originally known as the rare earths from their occurrence in oxides mixtures. Recently, some researchers have included two other elements-scandium and yttrium-in their discussion of rare earths. Yttrium (atomic number 39), which lies above lanthanum in transition group III of the periodic table and has a similar 3+ ion with a noble gas core, has both atomic and ionic radii similar in size to those of terbium and dysprosium and is generally found in nature with lanthanides. Scandium (atomic number 21) has a smaller ionic radius than yttrium and the lanthanides, and its chemical behavior is intermediate between that of aluminum and the lanthanides. It is found in nature with the lanthanides and yttrium. Rare earths are used widely in high-technology and clean-energy products because they impart special properties of magnetism, luminescence, and strength. Rare earths are also used in weapon systems to obtain the same properties.

  14. Is heterostyly rare on oceanic islands?

    PubMed Central

    Watanabe, Kenta; Sugawara, Takashi

    2015-01-01

    Heterostyly has been considered rare or absent on oceanic islands. However, there has been no comprehensive review on this issue. Is heterostyly truly rare on oceanic islands? What makes heterostyly rare on such islands? To answer these questions, we review the reproductive studies on heterostyly on oceanic islands, with special emphasis on the heterostylous genus Psychotria in the Pacific Ocean as a model system. Overall, not many reproductive studies have been performed on heterostylous species on oceanic islands. In Hawaiian Psychotria, all 11 species are thought to have evolved dioecy from distyly. In the West Pacific, three species on the oceanic Bonin and Lanyu Islands are distylous (Psychotria homalosperma, P. boninensis and P. cephalophora), whereas three species on the continental Ryukyu Islands show various breeding systems, such as distyly (P. serpens), dioecy (P. rubra) and monoecy (P. manillensis). On some other Pacific oceanic islands, possibilities of monomorphy have been reported. For many Psychotria species, breeding systems are unknown, although recent studies indicate that heterostylous species may occur on some oceanic islands. A shift from heterostyly to other sexual systems may occur on some oceanic islands. This tendency may also contribute to the rarity of heterostyly, in addition to the difficulty in colonization/autochthonous evolution of heterostylous species on oceanic islands. Further investigation of reproductive systems of Psychotria on oceanic islands using robust phylogenetic frameworks would provide new insights into plant reproduction on oceanic islands. PMID:26199401

  15. Is heterostyly rare on oceanic islands?

    PubMed

    Watanabe, Kenta; Sugawara, Takashi

    2015-07-21

    Heterostyly has been considered rare or absent on oceanic islands. However, there has been no comprehensive review on this issue. Is heterostyly truly rare on oceanic islands? What makes heterostyly rare on such islands? To answer these questions, we review the reproductive studies on heterostyly on oceanic islands, with special emphasis on the heterostylous genus Psychotria in the Pacific Ocean as a model system. Overall, not many reproductive studies have been performed on heterostylous species on oceanic islands. In Hawaiian Psychotria, all 11 species are thought to have evolved dioecy from distyly. In the West Pacific, three species on the oceanic Bonin and Lanyu Islands are distylous (Psychotria homalosperma, P. boninensis and P. cephalophora), whereas three species on the continental Ryukyu Islands show various breeding systems, such as distyly (P. serpens), dioecy (P. rubra) and monoecy (P. manillensis). On some other Pacific oceanic islands, possibilities of monomorphy have been reported. For many Psychotria species, breeding systems are unknown, although recent studies indicate that heterostylous species may occur on some oceanic islands. A shift from heterostyly to other sexual systems may occur on some oceanic islands. This tendency may also contribute to the rarity of heterostyly, in addition to the difficulty in colonization/autochthonous evolution of heterostylous species on oceanic islands. Further investigation of reproductive systems of Psychotria on oceanic islands using robust phylogenetic frameworks would provide new insights into plant reproduction on oceanic islands.

  16. Phase stable rare earth garnets

    DOEpatents

    Kuntz, Joshua D.; Cherepy, Nerine J.; Roberts, Jeffery J.; Payne, Stephen A.

    2013-06-11

    A transparent ceramic according to one embodiment includes a rare earth garnet comprising A.sub.hB.sub.iC.sub.jO.sub.12, where h is 3.+-.10%, i is 2.+-.10%, and j is 3.+-.10%. A includes a rare earth element or a mixture of rare earth elements, B includes at least one of aluminum, gallium and scandium, and C includes at least one of aluminum, gallium and scandium, where A is at a dodecahedral site of the garnet, B is at an octahedral site of the garnet, and C is at a tetrahedral site of the garnet. In one embodiment, the rare earth garment has scintillation properties. A radiation detector in one embodiment includes a transparent ceramic as described above and a photo detector optically coupled to the rare earth garnet.

  17. Effect of global climate change on rare trees and shrubs

    Treesearch

    Margaret S. Devall

    2008-01-01

    In the past, climate has fluctuated with periodsof cooler, warmer, drier or wetter weather thanat present. Plants have been able to adapt,but widespread, rapid warming could be disastrousfor rare trees and shrubs – i.e. thosenative species that are among an area’s most

  18. Using micropropagation to conserve threatened rare species in sustainable forests.

    Treesearch

    J.L. Edson; David L. Wenny; A.D. Leege-Brusven; R.L. Everett

    1997-01-01

    For forests to be sustainable, viable populations of rare plants should be maintained. Where habitat management alone cannot conserve species threatened by human activity, micropropagation may advance species recovery. Micropropagation protocols were developed for Pacific Northwest endemics; Hackelia venusta, Douglasia idahoensis, Astragalus species, and Cornus...

  19. Rare times rare: The hyponatremia, rhabdomyolysis, anterior compartment syndrome sequence

    PubMed Central

    Dubin, Ina; Gelber, Moshe

    2016-01-01

    Lesson Primary polydipsia occurs in up to 25% of patients with chronic psychiatric disorders (especially schizophrenia), related to the disease, its treatment or both. Urine output fails to match intake >10 L/day and water intoxication may develop. Rhabdomyolysis is a rare complication of hyponatremia, and an acute anterior compartment syndrome of the leg, an emergency, may be very rarely associated. PMID:27186379

  20. Rare earth speciality inorganic compounds

    SciTech Connect

    Gschneidner, K.A. Jr.

    1981-01-01

    This paper is a comprehensive review of the rare earth elements which include the Group IIIA elements Sc, Y and the lanthanide elements La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu. It covers their abundances, electronic structure, ionic radii, energy levels, thermodynamic properties, optical applications, separation chemistry, markets and statistics, electronic and magnetic applications, as well as mineral ores that contain rare earths, mixed rare earth chemical, and special uses of Y/sub 2/O/sub 3/. 30 references.

  1. Effects of spraying rare earths on contents of rare Earth elements and effective components in tea.

    PubMed

    Wang, Dongfeng; Wang, Changhong; Ye, Sheng; Qi, Hongtao; Zhao, Guiwen

    2003-11-05

    Rare earth (RE) fertilizer is widely applied in China to increase the yield and the quality of crops including tea. However, the effects of spraying RE fertilizer on the contents of rare earth elements (REE) and effective components in tea are unknown. The results from basin and field experiments show that the values of the REE concentrations in new shoots of tea plants and the concentration of REE in the soil (REE/REEs) either from control basins or from treatment basins were smaller than those in other parts of tea plant and similar between control and treatment. The longer the interval between spraying RE fertilizer and picking the shoots of tea plants, the less the effects from spraying. About 80% summation operator REE (the sum of the concentrations of 15 REE) in tea, whether it came from spraying or not, was insoluble in the infusion. About 10% the soluble REE of summation operator REE in tea infusion was bound to polysaccharide, and the amount of REE bound polysaccharide decreased over time. At least a 25 day safety interval is needed between spraying and picking if the microelement fertilizer is used, in order to enhance tea output and to ensure tea safety.

  2. Rare Earth Optical Temperature Sensor

    NASA Technical Reports Server (NTRS)

    Chubb, Donald L. (Inventor); Jenkins, Phillip (Inventor)

    2004-01-01

    A rare earth optical temperature sensor is disclosed for measuring high temperatures. Optical temperature sensors exist that channel emissions from a sensor to a detector using a light pipe. The invention uses a rare earth emitter to transform the sensed thermal energy into a narrow band width optical signal that travels to a detector using a light pipe. An optical bandpass filter at the detector removes any noise signal outside of the band width of the signal from the emitter.

  3. Rare beauty and charm decays

    NASA Astrophysics Data System (ADS)

    Blake, T.; LHCb Collaboration

    2017-07-01

    Rare beauty and charm decays can provide powerful probes of physics beyond the Standard Model. These proceedings summarise the latest measurements of rare beauty and charm decays from the LHCb experiment at the end of Run 1 of the LHC. Whilst the majority of the measurements are consistent with SM predictions, small differences are seen in the rate and angular distribution of ℓ- decay processes.

  4. [Adult-onset rare diseases].

    PubMed

    Pfliegler, György; Kovács, Erzsébet; Kovács, György; Urbán, Krisztián; Nagy, Valéria; Brúgós, Boglárka

    2014-03-02

    The present paper is focusing on rare diseases manifesting in late childhood or adulthood. A part of these syndromes are not of genetic origin, such as relatively or absolutely rare infections, autoimmune diseases, tumours, or diseases due to rare environmental toxic agents. In addition, even a large proportion of genetic disorders may develop in adulthood or may have adult forms as well, affecting are almost each medical specialization. Examples are storage disorders (e.g. adult form of Tay-Sachs disease, Gaucher-disease), enzyme deficiencies (e.g. ornithin-transcarbamylase deficiency of the urea cycle disorders), rare thrombophilias (e.g. homozygous factor V. Leiden mutation, antithrombin deficiency), or some rare monogenic disorders such as Huntington-chorea and many others. It is now generally accepted that at least half of the 6-8000 "rare diseases" belong either to the scope of adult-care (e.g. internal medicine, neurology), or to "age-neutral" specialities such as ophtalmology, dermatology etc.).

  5. The Not-So-Rare Earths.

    ERIC Educational Resources Information Center

    Muecke, Gunter K.; Moller, Peter

    1988-01-01

    Describes the characteristics of rare earth elements. Details the physical chemistry of rare earths. Reviews the history of rare earth chemistry and mineralogy. Discusses the mineralogy and crystallography of the formation of rare earth laden minerals found in the earth's crust. Characterizes the geologic history of rare earth elements. (CW)

  6. The Not-So-Rare Earths.

    ERIC Educational Resources Information Center

    Muecke, Gunter K.; Moller, Peter

    1988-01-01

    Describes the characteristics of rare earth elements. Details the physical chemistry of rare earths. Reviews the history of rare earth chemistry and mineralogy. Discusses the mineralogy and crystallography of the formation of rare earth laden minerals found in the earth's crust. Characterizes the geologic history of rare earth elements. (CW)

  7. Using multiple trait associations to define hydraulic functional types in plant communities of south-western Australia.

    PubMed

    Mitchell, Patrick J; Veneklaas, Erik J; Lambers, Hans; Burgess, Stephen S O

    2008-12-01

    Assessing the hydrological imbalance and associated land degradation issues facing much of southern Australia and other parts of the world requires a better understanding of the defining features of ecosystem water use and the design of sustainable agroecosystems. Thus, by grouping species with similar water-use strategies into 'hydraulic functional types' (HFTs), we investigated the characteristics of water use in species-rich plant communities of south-western Australia. HFTs were determined using multiple-trait associations between morphological and physiological traits relating to water transport, water-use efficiency and response to water deficit. Sixteen traits were assessed from a subset of 21 species from three plant communities located along a topographically determined soil- and water-availability gradient. Multivariate analyses showed that trait variation was least at sites with shallower soils and putatively lower water availability, suggesting a convergence of water-use strategies at sites where plants are exposed to large seasonal water deficits. Stem hydraulic parameters, including stem-specific hydraulic conductivity, conduit diameter and maximum percentage embolism, were positively correlated, indicating the generality that larger conduit diameter permits greater hydraulic efficiency and is associated with greater seasonal reductions in hydraulic conductivity in this ecosystem. Wood density was not correlated with these traits, but closely associated with species' ability to withstand more negative water potentials during summer. Long-term integrated water-use efficiency was lower in shallow-rooted species that exhibited more negative summer water potentials. Specific leaf area and minimum leaf water potential were correlated with a number of separate traits, and appear to represent key axes of trait variation that describe the water-use strategies of different HFTs along the topographic gradient. Five HFTs were classified using a resemblance

  8. The Lombardy Rare Donor Programme.

    PubMed

    Revelli, Nicoletta; Villa, Maria Antonietta; Paccapelo, Cinzia; Manera, Maria Cristina; Rebulla, Paolo; Migliaccio, Anna Rita; Marconi, Maurizio

    2014-01-01

    In 2005, the government of Lombardy, an Italian region with an ethnically varied population of approximately 9.8 million inhabitants including 250,000 blood donors, founded the Lombardy Rare Donor Programme, a regional network of 15 blood transfusion departments coordinated by the Immunohaematology Reference Laboratory of the Ca' Granda Ospedale Maggiore Policlinico in Milan. During 2005 to 2012, Lombardy funded LORD-P with 14.1 million euros. During 2005-2012 the Lombardy Rare Donor Programme members developed a registry of blood donors and a bank of red blood cell units with either rare blood group phenotypes or IgA deficiency. To do this, the Immunohaematology Reference Laboratory performed extensive serological and molecular red blood cell typing in 59,738 group O or A, Rh CCDee, ccdee, ccDEE, ccDee, K- or k- donors aged 18-55 with a record of two or more blood donations, including both Caucasians and ethnic minorities. In parallel, the Immunohaematology Reference Laboratory implemented a 24/7 service of consultation, testing and distribution of rare units for anticipated or emergent transfusion needs in patients developing complex red blood cell alloimmunisation and lacking local compatible red blood cell or showing IgA deficiency. Red blood cell typing identified 8,747, 538 and 33 donors rare for a combination of common antigens, negative for high-frequency antigens and with a rare Rh phenotype, respectively. In June 2012, the Lombardy Rare Donor Programme frozen inventory included 1,157 red blood cell units. From March 2010 to June 2012 one IgA-deficient donor was detected among 1,941 screened donors and IgA deficiency was confirmed in four previously identified donors. From 2005 to June 2012, the Immunohaematology Reference Laboratory provided 281 complex red blood cell alloimmunisation consultations and distributed 8,008 Lombardy Rare Donor Programme red blood cell units within and outside the region, which were transfused to 2,365 patients with no

  9. A tale of two rare wild buckwheats (Eriogonum subgenus Eucycla (Polygonaceae)) from Southeastern Arizona

    Treesearch

    John L. Anderson

    2007-01-01

    Unusual soils, compared to surrounding common soils, act as edaphic habitat islands and often harbor rare plants. These edaphic elements can be disjuncts or endemics. Two rare wild buckwheats from southeastern Arizona that grow on Tertiary lacustrine lakebed deposits have been found to be a disjunct, and an endemic. Eriogonum apachense from the Bylas...

  10. Bayesian analysis of rare events

    NASA Astrophysics Data System (ADS)

    Straub, Daniel; Papaioannou, Iason; Betz, Wolfgang

    2016-06-01

    In many areas of engineering and science there is an interest in predicting the probability of rare events, in particular in applications related to safety and security. Increasingly, such predictions are made through computer models of physical systems in an uncertainty quantification framework. Additionally, with advances in IT, monitoring and sensor technology, an increasing amount of data on the performance of the systems is collected. This data can be used to reduce uncertainty, improve the probability estimates and consequently enhance the management of rare events and associated risks. Bayesian analysis is the ideal method to include the data into the probabilistic model. It ensures a consistent probabilistic treatment of uncertainty, which is central in the prediction of rare events, where extrapolation from the domain of observation is common. We present a framework for performing Bayesian updating of rare event probabilities, termed BUS. It is based on a reinterpretation of the classical rejection-sampling approach to Bayesian analysis, which enables the use of established methods for estimating probabilities of rare events. By drawing upon these methods, the framework makes use of their computational efficiency. These methods include the First-Order Reliability Method (FORM), tailored importance sampling (IS) methods and Subset Simulation (SuS). In this contribution, we briefly review these methods in the context of the BUS framework and investigate their applicability to Bayesian analysis of rare events in different settings. We find that, for some applications, FORM can be highly efficient and is surprisingly accurate, enabling Bayesian analysis of rare events with just a few model evaluations. In a general setting, BUS implemented through IS and SuS is more robust and flexible.

  11. Building treasures for rare disorders.

    PubMed

    Baas, Melanie; Huisman, Sylvia; van Heukelingen, John; Koekkoek, Gerritjan; Laan, Henk-Willem; Hennekam, Raoul C

    2015-01-01

    The internet pre-eminently marks an era with unprecedented chances for patient care. Especially individuals with rare disorders and their families can benefit. Their handicap of low numbers vanishes and can become a strength, as small, motivated and well-organized international support groups allow easily fruitful collaborations with physicians and researchers. Jointly setting research agendas and building wikipedias has eventually led to building of multi-lingual databases of longitudinal data on physical and behavioural characteristics of individuals with several rare disorders which we call waihonapedias (waihona meaning treasure in Hawaiian). There are hurdles to take, like online security and reliability of diagnoses, but sharing experiences and true collaborations will allow better research and patient care for fewer costs to patients with rare disorders. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  12. Upconversion of rare Earth nanomaterials.

    PubMed

    Sun, Ling-Dong; Dong, Hao; Zhang, Pei-Zhi; Yan, Chun-Hua

    2015-04-01

    Rare earth nanomaterials, which feature long-lived intermediate energy levels and intraconfigurational 4f-4f transitions, are promising supporters for photon upconversion. Owing to their unique optical properties, rare earth upconversion nanomaterials have found applications in bioimaging, theranostics, photovoltaic devices, and photochemical reactions. Here, we review recent advances in the photon upconversion processes of these nanomaterials. We start by considering energy transfer models involved in the study of upconversion emissions, as well as well-established synthesis strategies to control the size and shape of rare earth upconversion nanomaterials. Progress in engineering energy transfer pathways, which play a dominant role in determining upconversion emission outputs, is then discussed. Lastly, representative optical applications of these materials are considered. The aim of this review is to provide inspiration for researchers to explore novel upconversion nanomaterials and extended optical applications.

  13. Angiomatous Hamartoma - A Rare Presentation

    PubMed Central

    Wadhera, Raman; Kaintura, Madhuri; Bhukar, Sandeep; Pillai, Dheeraj Shashikumar

    2016-01-01

    Eccrine Angiomatous Hamartoma (EAH) is a benign rare skin neoplasm characterised histologically by abnormal proliferation of sweat glands and surrounding capillaries and other dermal elements like fatty lobules and hair. It usually presents at birth or in early childhood in the form of solitary nodules mostly affecting the extremities. Here, we report a case of angiomatous hamartoma over the face which presented as a cystic swelling in preauricular region in a 55-year-old man. The late onset and a rare site for presentation of EAH prompted us to report the case. There is not even a single case of EAH arising in the “preauricular” region, reported. PMID:27790478

  14. Metacomprehension during Rare Word Comprehension

    ERIC Educational Resources Information Center

    Mcginnis, Debra; Saunders, Nikola N.; Burns, Ryan J.

    2007-01-01

    To examine metacomprehension during comprehension, undergraduates (n = 133) were asked to provide descriptions of how they determined the meaning of four rare words presented in short passages. Content analysis of these written descriptions revealed task-specific metacomprehension reflecting lexical, textbase, and situation model processes.…

  15. Metacomprehension during Rare Word Comprehension

    ERIC Educational Resources Information Center

    Mcginnis, Debra; Saunders, Nikola N.; Burns, Ryan J.

    2007-01-01

    To examine metacomprehension during comprehension, undergraduates (n = 133) were asked to provide descriptions of how they determined the meaning of four rare words presented in short passages. Content analysis of these written descriptions revealed task-specific metacomprehension reflecting lexical, textbase, and situation model processes.…

  16. Rare B decays at CDF

    SciTech Connect

    Farrington, Sinead M.; /Liverpool U.

    2006-10-01

    The confidence level limits of the CDF search for the B{sub s}{sup 0} and B{sub d}{sup 0} {yields} {mu}{sup +}{mu}{sup -} rare decays and the branching ratio measurement of B{sub s}{sup 0} {yields} D{sub s}{sup +} D{sub s}{sup -} are presented.

  17. Cherubism: A rare case report

    PubMed Central

    Kaur, Manpreet; Shah, Sonali; Babaji, Prashant; Singh, Jaideep; Nair, Divya; Kamble, Suresh S

    2014-01-01

    Cherubism is a rare congenital disease resulting in malformation of the jaw. It occurs before the age of 5 years and regress spontaneously after puberty. It can result into enlargement of the jaw bone, tooth displacement, facial disfigurement and psychological trauma to patient. Hence, the understanding about the condition, its progression and management is necessary. PMID:25097445

  18. RARE II: The Administration's View

    ERIC Educational Resources Information Center

    Cutler, M. Rupert

    1977-01-01

    RARE II is a new Roadless Area Review and Evaluation of the National Forest system. Administrators are attempting to inventory existing wilderness areas and to determine criteria for setting aside additional ones. This information will be used for the required 1980 update of the national assessment of forests and rangelands. (MA)

  19. Treatable inherited rare movement disorders.

    PubMed

    Jinnah, H A; Albanese, Alberto; Bhatia, Kailash P; Cardoso, Francisco; Da Prat, Gustavo; de Koning, Tom J; Espay, Alberto J; Fung, Victor; Garcia-Ruiz, Pedro J; Gershanik, Oscar; Jankovic, Joseph; Kaji, Ryuji; Kotschet, Katya; Marras, Connie; Miyasaki, Janis M; Morgante, Francesca; Munchau, Alexander; Pal, Pramod Kumar; Rodriguez Oroz, Maria C; Rodríguez-Violante, Mayela; Schöls, Ludger; Stamelou, Maria; Tijssen, Marina; Uribe Roca, Claudia; de la Cerda, Andres; Gatto, Emilia M

    2017-09-01

    There are many rare movement disorders, and new ones are described every year. Because they are not well recognized, they often go undiagnosed for long periods of time. However, early diagnosis is becoming increasingly important. Rapid advances in our understanding of the biological mechanisms responsible for many rare disorders have enabled the development of specific treatments for some of them. Well-known historical examples include Wilson disease and dopa-responsive dystonia, for which specific and highly effective treatments have life-altering effects. In recent years, similarly specific and effective treatments have been developed for more than 30 rare inherited movement disorders. These treatments include specific medications, dietary changes, avoidance or management of certain triggers, enzyme replacement therapy, and others. This list of treatable rare movement disorders is likely to grow during the next few years because a number of additional promising treatments are actively being developed or evaluated in clinical trials. © 2017 International Parkinson and Movement Disorder Society. © 2017 International Parkinson and Movement Disorder Society.

  20. Rare decays at the Tevatron

    SciTech Connect

    Farrington, S.M.; /Liverpool U.

    2006-01-01

    The confidence level limits of the CDF and D0 searches for the B{sub s}{sup 0}, B{sub d}{sup 0} {yields} {mu}{sup +}{mu}{sup -} and B{sub s}{sup 0} {yields} {mu}{sup +}{mu}{sup -}{phi} rare decays are presented.

  1. Exome sequencing deciphers rare diseases.

    PubMed

    Maxmen, Amy

    2011-03-04

    Two years ago, NIH's Undiagnosed Diseases Program began delivering genomics to the clinic on an unprecedented scale. Now, with 128 exomes sequenced and 39 rare diseases diagnosed, the program's success is paving the way for widespread personal genomics while pioneering new techniques for reigning in the "tsunami" of genomics data.

  2. Selective Emitter Pumped Rare Earth Laser

    NASA Technical Reports Server (NTRS)

    Chubb, Donald L. (Inventor); Patton, Martin O. (Inventor)

    2001-01-01

    A selective emitter pumped rare earth laser provides an additional type of laser for use in many laser applications. Rare earth doped lasers exist which are pumped with flashtubes or laser diodes. The invention uses a rare earth emitter to transform thermal energy input to a spectral band matching the absorption band of a rare earth in the laser in order to produce lasing.

  3. [Adamantinoma of the clavicle: rare tumor for rare location].

    PubMed

    Rifi, M; Mahfoud, M; Zouaidia, F; El Yaacoubi, M

    2013-06-01

    Adamantinoma is a rare primary low-grade malignant tumor composed of cells with epithelial and fibrous characteristics. It represents 0.4% of all primitive malignant bone tumours. It is predominantly located in the mid-shaft of tibia. We report an adamantinoma of the clavicle, occurring in a 19-year-old female patient. The lateral half of the clavicle was excised. After a period of 3 years, she is still remaining free of local recurrence and metastatic disease.

  4. Rare essentials: drugs for rare diseases as essential medicines.

    PubMed

    Stolk, Pieter; Willemen, Marjolein J C; Leufkens, Hubert G M

    2006-09-01

    Since 1977, the WHO Model List of Essential Medicines (EML), published by WHO, has provided advice for Member States that struggle to decide which pharmaceutical technologies should be provided to patients within their public health systems. Originating from outside WHO, an incentive system has been put in place by various governments for the development of medicines for rare diseases ("orphan drugs"). With progress in pharmaceutical research (e.g. drugs targeted for narrower indications), these medicines will feature more often on future public health agendas. However, when current definitions for selecting essential medicines are applied strictly, orphan drugs cannot be part of the WHO Essential Medicines Programme, creating the risk that WHO may lose touch with this field. In our opinion WHO should explicitly include orphan drugs in its policy sphere by composing a complementary Orphan Medicines Model List as an addition to the EML. This complementary list of "rare essentials" could aid policy-makers and patients in, for example, emerging countries to improve access to these drugs and stimulate relevant policies. Furthermore, inconsistencies in the current EML with regard to medicines for rare diseases can be resolved. In this paper we propose selection criteria for an Orphan Medicines Model List that could form a departure point for future work towards an extensive WHO Orphan Medicines Programme.

  5. Rare essentials: drugs for rare diseases as essential medicines.

    PubMed Central

    Stolk, Pieter; Willemen, Marjolein J. C.; Leufkens, Hubert G. M.

    2006-01-01

    Since 1977, the WHO Model List of Essential Medicines (EML), published by WHO, has provided advice for Member States that struggle to decide which pharmaceutical technologies should be provided to patients within their public health systems. Originating from outside WHO, an incentive system has been put in place by various governments for the development of medicines for rare diseases ("orphan drugs"). With progress in pharmaceutical research (e.g. drugs targeted for narrower indications), these medicines will feature more often on future public health agendas. However, when current definitions for selecting essential medicines are applied strictly, orphan drugs cannot be part of the WHO Essential Medicines Programme, creating the risk that WHO may lose touch with this field. In our opinion WHO should explicitly include orphan drugs in its policy sphere by composing a complementary Orphan Medicines Model List as an addition to the EML. This complementary list of "rare essentials" could aid policy-makers and patients in, for example, emerging countries to improve access to these drugs and stimulate relevant policies. Furthermore, inconsistencies in the current EML with regard to medicines for rare diseases can be resolved. In this paper we propose selection criteria for an Orphan Medicines Model List that could form a departure point for future work towards an extensive WHO Orphan Medicines Programme. PMID:17128345

  6. [Intoxications with plants].

    PubMed

    Kupper, Jacqueline; Reichert, Cornelia

    2009-05-01

    Ingestions of plants rarely lead to life-threatening intoxications. Highly toxic plants, which can cause death, are monkshood (Aconitum sp.), yew (Taxus sp.) and autumn crocus (Colchicum autumnale). Lethal ingestions of monkshood and yew are usually suicides, intoxications with autumn crocus are mostly accidental ingestions of the leaves mistaken for wild garlic (Allium ursinum). Severe intoxications can occur with plants of the nightshade family like deadly nightshade (Atropa belladonna), angel's trumpet (Datura suaveolens) or jimsonweed (Datura stramonium). These plants are ingested for their psychoactive effects. Ingestion of plant material by children most often only causes minor symptoms or no symptoms at all, as children usually do not eat great quantities of the plants. They are especially attracted by the colorful berries. There are plants with mostly cardiovascular effects like monkshood, yew and Digitalis sp. Some of the most dangerous plants belong to this group. Plants of the nightshade family cause an anticholinergic syndrome. With golden chain (Laburnum anagyroides), castor bean (Ricinus communis) and raw beans (Phaseolus vulgaris) we see severe gastrointestinal effects. Autumn crocus contains a cell toxin, colchicine, which leads to multiorgan failure. Different plants are irritative or even caustic to the skin. Treatment is usually symptomatic. Activated charcoal is administered within one hour after ingestion (1 g/kg). Endoscopic removal of plant material can be considered with ingestions of great quantities of highly toxic plants. Administration of repeated doses of charcoal (1-2 g/h every 2-4 hours) may be effective in case of oleander poisoning. There exist only two antidotes: Anti-digoxin Fab fragments can be used with cardenolide glycoside-containing plants (Digitalis sp., Oleander). Physostigmine is the antidote for severe anticholinergic symptoms of the CNS. Antibodies against colchicine, having been developed in France, are not available at

  7. Rare Earth Garnet Selective Emitter

    NASA Technical Reports Server (NTRS)

    Lowe, Roland A.; Chubb, Donald L.; Farmer, Serene C.; Good, Brian S.

    1994-01-01

    Thin film Ho-YAG and Er-YAG emitters with a platinum substrate exhibit high spectral emittance in the emission band (epsilon(sub lambda) approx. = 0.75, sup 4)|(sub 15/2) - (sup 4)|(sub 13/2),for Er-YAG and epsilon(sub lambda) approx. = 0.65, (sup 5)|(sub 7) - (sup 5)|(sub 8) for Ho-YAG) at 1500 K. In addition, low out-of-band spectral emittance, epsilon(sub lambda) less than 0.2, suggest these materials would be excellent candidates for high efficiency selective emitters in thermophotovoltaic (TPV) systems operating at moderate temperatures (1200-1500 K). Spectral emittance measurements of the thin films were made (1.2 less than lambda less than 3.0 microns) and compared to the theoretical emittances calculated using measured values of the spectral extinction coefficient. In this paper we present the results for a new class of rare earth ion selective emitters. These emitters are thin sections (less than 1 mm) of yttrium aluminum garnet (YAG) single crystal with a rare earth substitutional impurity. Selective emitters in the near IR are of special interest for thermophotovoltaic (TPV) energy conversion. The most promising solid selective emitters for use in a TPV system are rare earth oxides. Early spectral emittance work on rare earth oxides showed strong emission bands in the infrared (0.9 - 3 microns). However, the emittance outside the emission band was also significant and the efficiency of these emitters was low. Recent improvements in efficiency have been made with emitters fabricated from fine (5 - 10 microns) rare earth oxide fibers similar to the Welsbach mantle used in gas lanterns. However, the rare earth garnet emitters are more rugged than the mantle type emitters. A thin film selective emitter on a low emissivity substrate such as gold, platinum etc., is rugged and easily adapted to a wide variety of thermal sources. The garnet structure and its many subgroups have been successfully used as hosts for rare earth ions, introduced as substitutional

  8. [Care for patients with rare diseases].

    PubMed

    Smetsers, Stephanie E; Takkenberg, J J M Hanneke; Bierings, Marc B

    2014-01-01

    A rare disease usually concerns only a handful of patients, but all patients with a rare disease combined represent a significant health burden. Due to limited knowledge and the absence of treatment guidelines, patients with rare diseases usually experience delayed diagnosis and suboptimal treatment. Historically, rare diseases have never been considered a major health problem. However, rare diseases have recently been receiving increased attention. In the Netherlands, a national plan for rare diseases was published in late 2013, with recommendations on how to improve the organisation of healthcare for people with rare diseases. Using the example of the rare disease Fanconi anemia, this paper describes the challenges and opportunities in organising healthcare for rare diseases. Two critical steps in optimising healthcare for rare diseases are developing multidisciplinary healthcare teams and stimulating patient empowerment. Optimal cooperation between patients, patient organisations, multidisciplinary healthcare teams and scientists is of great importance. In this respect, transition to adult healthcare requires special attention.

  9. Neonatal Hemophilia: A Rare Presentation

    PubMed Central

    Proença, Elisa; Godinho, Cristina; Oliveira, Dulce; Guedes, Ana; Morais, Sara; Carvalho, Carmen

    2015-01-01

    Hemophilia A is a X-linked hereditary condition that lead to decreased factor VIII activity, occurs mainly in males. Decreased factor VIII activity leads to increased risk of bleeding events. During neonatal period, diagnosis is made after post-partum bleeding complication or unexpected bleeding after medical procedures. Subgaleal hemorrhage during neonatal period is a rare, severe extracranial bleeding with high mortality and usually related to traumatic labor or coagulation disorders. Subgaleal hemorrhage complications result from massive bleeding. We present a neonate with unremarkable family history and uneventful pregnancy with a vaginal delivery with no instrumentation, presenting with severe subgaleal bleeding at 52 hours of life. Aggressive support measures were implemented and bleeding managed. The unexpected bleeding lead to a coagulation study and the diagnosis of severe hemophilia A. There were no known sequelae. This case shows a rare hemophilia presentation reflecting the importance of coagulation studies when faced with unexplained severe bleeding. PMID:26734126

  10. Replica trick for rare samples

    NASA Astrophysics Data System (ADS)

    Rizzo, Tommaso

    2014-05-01

    In the context of disordered systems with quenched Hamiltonians I address the problem of characterizing rare samples where the thermal average of a specific observable has a value different from the typical one. These rare samples can be selected through a variation of the replica trick which amounts to replicating the system and dividing the replicas intwo two groups containing, respectively, M and -M replicas. Replicas in the first (second) group experience a positive (negative) small field O (1/M) conjugate to the observable considered and the M →∞ limit is to be taken in the end. Applications to the random-field Ising model and to the Sherrington-Kirkpatrick model are discussed.

  11. Ectopic testis: a rare case.

    PubMed

    Ebrahimi, Ali

    2010-01-01

    Congenital undescending testis is a common anomaly of testis, but we had a rare case of ectopic testis. A 15-month-old infant was operated emergently because of left incarcerate inguinal hernia. Intraoperative exploration of hernial sac revealed two ectopic testes with one spermatic cord proximally but in the middle divided to two spermatic cords in a 8 shape. There was an important point about vas deferens as it was single proximal to the chord, but divided into two in the middle of the chord. Vessels showed a similar condition about. We released both testes and brought down both of them into scrotum. This is a rare case of ectopic testis transectopia with partially common vas and vessels.

  12. Chondroectodermal Dysplasia: A Rare Syndrome

    PubMed Central

    Tahririan, Dana; Eshghi, Alireza; Givehchian, Pirooz; Tahririan, Mohammad Ali

    2014-01-01

    Chondroectodermal dysplasia (Ellis-Van Creveld syndrome) is a rare autosomal recessive congenital abnormality. This syndrome is characterized by a spectrum of clinical findings, among which chondrodystrophy, polydactyly, ectodermal dysplasia, and congenital cardiac anomalies are the most common. It is imperative to not overlook the cardiac complications in patients with this syndrome during dental procedures. The case presented here, although quite rare, was detected under normal conditions and can be alarming for dental care providers. Clinical reports outline the classical and unusual oral and dental manifestations, which help health care providers diagnose chondroectodermal dysplasia, and refer patients with this syndrome to appropriate health care professionals to receive treatment to prevent further cardiac complications and bone deformities. PMID:25628672

  13. Rare Earth Optical Temperature Sensor

    NASA Technical Reports Server (NTRS)

    Chubb, Donald L.; Wolford, David S.

    2000-01-01

    A new optical temperature sensor suitable for high temperatures (greater than 1700 K) and harsh environments is introduced. The key component of the sensor is the rare earth material contained at the end of a sensor that is in contact with the sample being measured. The measured narrow wavelength band emission from the rare earth is used to deduce the sample temperature. A simplified relation between the temperature and measured radiation was verified experimentally. The upper temperature limit of the sensor is determined by material limits to be approximately 2000 C. The lower limit, determined by the minimum detectable radiation, is found to be approximately 700 K. At high temperatures 1 K resolution is predicted. Also, millisecond response times are calculated.

  14. Erythromelalgia: a rare microvascular disease.

    PubMed

    Latessa, Victoria

    2010-06-01

    Erythromelalgia (EM) is a rare condition of unknown etiology that results in intense, burning pain and redness primarily of the feet, and, even more rarely, in the hands. Most cases are idiopathic (primary EM); others occur secondary to medical conditions, such as autoimmune diseases, and neurological or hematological disorders. Symptoms are episodic and can result in severe disability. Triggers, such as exposure to warmth, pressure or exercise, become apparent to those afflicted with this condition; however, triggers may be unavoidable during the course of daily living. There are no diagnostic tests for EM. Diagnosis is based on history, physical examination during symptomatic episode and the exclusion of other probable causes for the syndrome. Early recognition of the signs and symptoms as well as early treatment offer patients the best hope of remissions and improved quality of life. (c) 2010 Society for Vascular Nursing, Inc. Published by Mosby, Inc. All rights reserved.

  15. Testicular calculus: A rare case.

    PubMed

    Sen, Volkan; Bozkurt, Ozan; Demır, Omer; Tuna, Burcin; Yorukoglu, Kutsal; Esen, Adil

    2015-01-01

    Testicular calculus is an extremely rare case with unknown etiology and pathogenesis. To our knowledge, here we report the third case of testicular calculus. A 31-year-old man was admitted to our clinic with painful solid mass in left testis. After diagnostic work-up for a possible testicular tumour, he underwent inguinal orchiectomy and histopathologic examination showed a testicular calculus. Case hypothesis: Solid testicular lesions in young adults generally correspond to testicular cancer. Differential diagnosis should be done carefully. Future implications: In young adults with painful and solid testicular mass with hyperechogenic appearance on scrotal ultrasonography, testicular calculus must be kept in mind in differential diagnosis. Further reports on this topic may let us do more clear recommendations about the etiology and treatment of this rare disease.

  16. Sirenomelia apus: a rare deformity.

    PubMed

    Kshirsagar, Vinayak Y; Ahmed, Minhajuddin; Colaco, Sylvia M

    2012-07-01

    Sirenomelia also known as the mermaid syndrome, is a rare congenital malformation of uncertain etiology. It is characterized by fusion of the lower limbs and commonly associated with severe urogenital and gastrointestinal malformations. There are approximately 300 cases reported in the literature, 15% of which are associated with twinning, most often monozygotic. The syndrome of caudal regression is thought to be the result of injury to the caudal mesoderm early in gestation.

  17. Intracranial chondroma: a rare entity.

    PubMed

    Maheshwari, Veena; Mehdi, Ghazala; Varshney, Manoranjan; Jain, Anshu; Vashishtha, Sonal; Gaur, Kavita; Srivastava, Vinod Kumar

    2011-05-12

    Intracranial chondroma is a rare benign cartilaginous tumour with an incidence of less than 1% of all primary intracranial tumours. The authors are reporting here a case of intracranial chondroma in a 40-year-old man who presented with 5-month history of headache and gradual diminution of vision. A tentative diagnosis of chondroma was made on imprint cytology which was confirmed on histopathological examination.

  18. Rare mutations in evolutionary dynamics

    NASA Astrophysics Data System (ADS)

    Amadori, Anna Lisa; Calzolari, Antonella; Natalini, Roberto; Torti, Barbara

    2015-12-01

    In this paper we study the effect of rare mutations, driven by a marked point process, on the evolutionary behavior of a population. We derive a Kolmogorov equation describing the expected values of the different frequencies and prove some rigorous analytical results about their behavior. Finally, in a simple case of two different quasispecies, we are able to prove that the rarity of mutations increases the survival opportunity of the low fitness species.

  19. Os Odontoideum: Rare Cervical Lesion

    DTIC Science & Technology

    2011-11-01

    the articulation between C1 and the os odontoideum on flexion imaging. The remainder of his cervical vertebral bodies had normal alignment with no...appears normal. Figure 3. Flexion view of plain cervical spine. This image shows abnormal translation of the articulation between C1 and the C2 os...worldwide. Peer Reviewed Title: Os Odontoideum: Rare Cervical Lesion Journal Issue: Western Journal of Emergency Medicine, 12(4) Author: Robson

  20. A rare case modafinil dependence.

    PubMed

    Krishnan, Raman; Chary, Krishnan Vengadaragava

    2015-01-01

    Modafinil, a non-amphetamine psychostimulant, is indicated for narcolepsy, shift work sleep disorder and severe obstructive sleep apnea syndrome. Modafinil is prescribed at the dose of 100 mg once in a day or as two doses, 12 h apart in a day. It has also been found that it reduces cocaine dependence and withdrawal phenomenon. Modafinil is claimed to have very low liability for abuse and dependence. Here we report a rare case of modafinil dependence.

  1. Os Odontoideum: Rare Cervical Lesion

    PubMed Central

    Robson, Kristie A

    2011-01-01

    We report the case of a 22-year-old Marine who presented to the emergency department, after a martial arts exercise, with transient weakness and numbness in all extremities. Computed tomography cervical spine radiographs revealed os odontoideum. Lateral flexion–extension radiographs identified atlanto-axillary instability. This abnormality is rare and can be career ending for military members who do not undergo surgical fusion. PMID:22224150

  2. Hepatic cysticercosis: a rare entity.

    PubMed

    Chaudhary, Vikas; Bano, Shahina; Kumar, Praveen; Narula, Mahender Kaur; Anand, Rama

    2014-12-01

    Hepatic cysticercosis is a very rare entity; only four cases have been reported to date. High-resolution ultrasonography of the abdomen is the initial and most reliable modality for evaluation of hepatic cysticercosis. Medical therapy is the mainstay of treatment. We report a case of hepatic cysticercosis in a 28-year-old male who presented with right upper quadrant pain, fever, and jaundice. The article also describes the imaging patterns of hepatic cysticercosis based on different stages of evolution.

  3. Microbial community assembly, theory and rare functions.

    PubMed

    Pholchan, Mujalin K; Baptista, Joana de C; Davenport, Russell J; Sloan, William T; Curtis, Thomas P

    2013-01-01

    Views of community assembly have traditionally been based on the contrasting perspectives of the deterministic niche paradigm and stochastic neutral models. This study sought to determine if we could use empirical interventions conceived from a niche and neutral perspective to change the diversity and evenness of the microbial community within a reactor treating wastewater and to see if there was any associated change in the removal of endocrine disrupting compounds (EDCs). The systematic removal of EDCs and micropollutants from biological treatment systems is a major challenge for environmental engineers. We manipulated pairs of bioreactors in an experiment in which "niche" (temporal variation in resource concentration and resource complexity) and "neutral" (community size and immigration) attributes were changed and the effect on the detectable diversity and the removal of steroidal estrogens was evaluated. The effects of manipulations on diversity suggested that both niche and neutral processes are important in community assembly. We found that temporal variation in environmental conditions increased diversity but resource complexity did not. Larger communities had greater diversity but attempting to increase immigration by adding soil had the opposite effect. The effects of the manipulations on EDC removal efficiency were complex. Decreases in diversity, which were associated with a decrease in evenness, were associated with an increase in EDC removal. A simple generalized neutral model (calibrated with parameters typical of wastewater treatment plants) showed that decreases in diversity should lead to the increase in abundance of some ostensibly taxa rare. We conclude that neither niche and neutral perspectives nor the effect of diversity on putative rare functions can be properly understood by naïve qualitative observations. Instead, the relative importance of the key microbial mechanisms must be determined and, ideally, expressed mathematically.

  4. Microbial community assembly, theory and rare functions

    PubMed Central

    Pholchan, Mujalin K.; Baptista, Joana de C.; Davenport, Russell J.; Sloan, William T.; Curtis, Thomas P.

    2013-01-01

    Views of community assembly have traditionally been based on the contrasting perspectives of the deterministic niche paradigm and stochastic neutral models. This study sought to determine if we could use empirical interventions conceived from a niche and neutral perspective to change the diversity and evenness of the microbial community within a reactor treating wastewater and to see if there was any associated change in the removal of endocrine disrupting compounds (EDCs). The systematic removal of EDCs and micropollutants from biological treatment systems is a major challenge for environmental engineers. We manipulated pairs of bioreactors in an experiment in which “niche” (temporal variation in resource concentration and resource complexity) and “neutral” (community size and immigration) attributes were changed and the effect on the detectable diversity and the removal of steroidal estrogens was evaluated. The effects of manipulations on diversity suggested that both niche and neutral processes are important in community assembly. We found that temporal variation in environmental conditions increased diversity but resource complexity did not. Larger communities had greater diversity but attempting to increase immigration by adding soil had the opposite effect. The effects of the manipulations on EDC removal efficiency were complex. Decreases in diversity, which were associated with a decrease in evenness, were associated with an increase in EDC removal. A simple generalized neutral model (calibrated with parameters typical of wastewater treatment plants) showed that decreases in diversity should lead to the increase in abundance of some ostensibly taxa rare. We conclude that neither niche and neutral perspectives nor the effect of diversity on putative rare functions can be properly understood by naïve qualitative observations. Instead, the relative importance of the key microbial mechanisms must be determined and, ideally, expressed mathematically

  5. Rare Species Support Vulnerable Functions in High-Diversity Ecosystems

    PubMed Central

    Mouillot, David; Bellwood, David R.; Baraloto, Christopher; Chave, Jerome; Galzin, Rene; Harmelin-Vivien, Mireille; Kulbicki, Michel; Lavergne, Sebastien; Lavorel, Sandra; Mouquet, Nicolas; Paine, C. E. Timothy; Renaud, Julien; Thuiller, Wilfried

    2013-01-01

    Around the world, the human-induced collapses of populations and species have triggered a sixth mass extinction crisis, with rare species often being the first to disappear. Although the role of species diversity in the maintenance of ecosystem processes has been widely investigated, the role of rare species remains controversial. A critical issue is whether common species insure against the loss of functions supported by rare species. This issue is even more critical in species-rich ecosystems where high functional redundancy among species is likely and where it is thus often assumed that ecosystem functioning is buffered against species loss. Here, using extensive datasets of species occurrences and functional traits from three highly diverse ecosystems (846 coral reef fishes, 2,979 alpine plants, and 662 tropical trees), we demonstrate that the most distinct combinations of traits are supported predominantly by rare species both in terms of local abundance and regional occupancy. Moreover, species that have low functional redundancy and are likely to support the most vulnerable functions, with no other species carrying similar combinations of traits, are rarer than expected by chance in all three ecosystems. For instance, 63% and 98% of fish species that are likely to support highly vulnerable functions in coral reef ecosystems are locally and regionally rare, respectively. For alpine plants, 32% and 89% of such species are locally and regionally rare, respectively. Remarkably, 47% of fish species and 55% of tropical tree species that are likely to support highly vulnerable functions have only one individual per sample on average. Our results emphasize the importance of rare species conservation, even in highly diverse ecosystems, which are thought to exhibit high functional redundancy. Rare species offer more than aesthetic, cultural, or taxonomic diversity value; they disproportionately increase the potential breadth of functions provided by ecosystems across

  6. Rare species support vulnerable functions in high-diversity ecosystems.

    PubMed

    Mouillot, David; Bellwood, David R; Baraloto, Christopher; Chave, Jerome; Galzin, Rene; Harmelin-Vivien, Mireille; Kulbicki, Michel; Lavergne, Sebastien; Lavorel, Sandra; Mouquet, Nicolas; Paine, C E Timothy; Renaud, Julien; Thuiller, Wilfried

    2013-01-01

    Around the world, the human-induced collapses of populations and species have triggered a sixth mass extinction crisis, with rare species often being the first to disappear. Although the role of species diversity in the maintenance of ecosystem processes has been widely investigated, the role of rare species remains controversial. A critical issue is whether common species insure against the loss of functions supported by rare species. This issue is even more critical in species-rich ecosystems where high functional redundancy among species is likely and where it is thus often assumed that ecosystem functioning is buffered against species loss. Here, using extensive datasets of species occurrences and functional traits from three highly diverse ecosystems (846 coral reef fishes, 2,979 alpine plants, and 662 tropical trees), we demonstrate that the most distinct combinations of traits are supported predominantly by rare species both in terms of local abundance and regional occupancy. Moreover, species that have low functional redundancy and are likely to support the most vulnerable functions, with no other species carrying similar combinations of traits, are rarer than expected by chance in all three ecosystems. For instance, 63% and 98% of fish species that are likely to support highly vulnerable functions in coral reef ecosystems are locally and regionally rare, respectively. For alpine plants, 32% and 89% of such species are locally and regionally rare, respectively. Remarkably, 47% of fish species and 55% of tropical tree species that are likely to support highly vulnerable functions have only one individual per sample on average. Our results emphasize the importance of rare species conservation, even in highly diverse ecosystems, which are thought to exhibit high functional redundancy. Rare species offer more than aesthetic, cultural, or taxonomic diversity value; they disproportionately increase the potential breadth of functions provided by ecosystems across

  7. Antibiotic use in plant agriculture.

    PubMed

    McManus, Patricia S; Stockwell, Virginia O; Sundin, George W; Jones, Alan L

    2002-01-01

    Antibiotics have been used since the 1950s to control certain bacterial diseases of high-value fruit, vegetable, and ornamental plants. Today, the antibiotics most commonly used on plants are oxytetracycline and streptomycin. In the USA, antibiotics applied to plants account for less than 0.5% of total antibiotic use. Resistance of plant pathogens to oxytetracycline is rare, but the emergence of streptomycin-resistant strains of Erwinia amylovora, Pseudomonas spp., and Xanthomonas campestris has impeded the control of several important diseases. A fraction of streptomycin-resistance genes in plant-associated bacteria are similar to those found in bacteria isolated from humans, animals, and soil, and are associated with transfer-proficient elements. However, the most common vehicles of streptomycin-resistance genes in human and plant pathogens are genetically distinct. Nonetheless, the role of antibiotic use on plants in the antibiotic-resistance crisis in human medicine is the subject of debate.

  8. A subcontinental view of forest plant invasions

    Treesearch

    Christopher M. Oswalt; Songlin Fei; Qinfeng Guo; Basil V. Iannone III; Sonja N. Oswalt; Bryan C. Pijanowski; Kevin M. Potter

    2015-01-01

    Over the last few decades, considerable attention has focused on small-scale studies of invasive plants and invaded systems. Unfortunately, small scale studies rarely provide comprehensive insight into the complexities of biological invasions at macroscales. Systematic and repeated monitoring of biological invasions at broad scales are rare. In this report, we...

  9. Covariation of soil bacterial composition with plant rarity.

    PubMed

    Huguet, Valérie; Rudgers, Jennifer A

    2010-11-01

    Rare and common plants are predicted to host different rhizospheric microbes. To evaluate this prediction, we used terminal restriction fragment length polymorphism (T-RFLP) analysis to compare rhizospheric bacteria from eight native grass species whose local abundances in their natural ecosystem spanned a 15-fold range. We observed that locally rare versus common plants are associated with divergent bacterial communities.

  10. Covariation of Soil Bacterial Composition with Plant Rarity ▿ †

    PubMed Central

    Huguet, Valérie; Rudgers, Jennifer A.

    2010-01-01

    Rare and common plants are predicted to host different rhizospheric microbes. To evaluate this prediction, we used terminal restriction fragment length polymorphism (T-RFLP) analysis to compare rhizospheric bacteria from eight native grass species whose local abundances in their natural ecosystem spanned a 15-fold range. We observed that locally rare versus common plants are associated with divergent bacterial communities. PMID:20851959

  11. Esophageal Lipoma: A Rare Tumor

    PubMed Central

    Feldman, Jeremy; Tejerina, Manfred; Hallowell, Michael

    2012-01-01

    Esophageal lipomas are rare tumors, making up 0.4% of all digestive tract benign neoplasms. Most of these lesions are clinically silent as a result of their small size, however, the majority of lesions over 4 cm have been reported to cause dysphagia, regurgitation and/or epigastralgia. We report a case of a 53 year-old African American female who presented with dysphagia. Computed tomography of the chest and esophagram confirmed esophageal lipoma as the cause of the patient’s symptoms. Accurately diagnosing an esophageal lipoma is crucial in order to rule out potential malignant lesions, relieve patient symptoms and plan the appropriate treatment. PMID:23365708

  12. Rare Gas Halide (RGH) Kinetics.

    DTIC Science & Technology

    1988-02-01

    Technolog , Inc.. 2755 Northup Way, Bellevue, Washington 98004-1495 (Received Il August 1987; accepted for publication 12 October 1987) Time-dependent density...8217 - Z ¢L --- ;-; Z¢ < : 2 2 2 e - 2 l ¢ - -- - P-2 -V, 2 " ’ ’’’ 2.,..’ * -x ’ ,’* - SSpectra Technology flT U Fr CoPY CContract N00014-85-C-084 3...RARE GAS HALIDE (RGH) in KINETICS FINAL REPORT< S Submitted to OFFICE OF NAVAL RESEARCH DEPARTMENT OF THE NAVY Submitted by SPECTRA TECHNOLOGY , INC

  13. Rare B Decays at Babar

    SciTech Connect

    Palombo, Fernando; Collaboration, for the BABAR

    2009-01-12

    The author presents some of the most recent BABAR measurements for rare B decays. These include rate asymmetries in the B decays to K{sup (*)}l{sup +}l{sup -} and K{sup +}{pi}{sup -} and branching fractions in the B decays to l{sup +}{nu}{sub l}, K{sub 1}(1270){sup +}{pi}{sup -} and K{sub 1}(1400){sup +}{pi}{sup -}. The author also reports a search for the B{sup +} decay to K{sub S}{sup 0}K{sub S}{sup 0}{pi}{sup +}.

  14. [Rare renal anomalies in childhood].

    PubMed

    Arambasić, Jadranka; Puseljić, Silvija; Angebrandt, Snjezana; Puseljić, Ivo

    2003-01-01

    Three patients with megacalycosis, a rare ren anomaly which includes dilatation of all ren calices, are presented. The symptoms of acute uroinfection were present in all three patients. The patients underwent clinical observation, laboratory testing, and renal ultrasound. Ultrasound revealed unilateral hydronephrosis in all three patients. Additional examinations included static and dynamic renal scintigraphy, voiding cystourethrography, and intravenous urography which pointed to unilateral megacalycosis. The symptoms of acute uroinfection were probably triggered by urinary stasis in dilated calices. Surgical intervention is not indicated in megacalycosis. The increasing incidence of uroinfection, urolithiasis and hematuria imposed the need of continuous follow-up in these patients.

  15. Pseudohypoparathyroidism, Rare Cause of Hypocalcaemia!

    PubMed Central

    Dosi, Rupal V.; Ambaliya, Annirudh P.; Joshi, Harshal K.; Patell, Rushad D.

    2013-01-01

    Pseudohypoparathyroidism is a rare disorder which is characterized by end organ parathormone resistance, which causes hypocalcaemia, hyperphosphataemia and high parathormone levels. We are reporting here case of a young male who had symptoms of chronic hypocalcaemia, with a positive Trousseau’s and Chvostek’s sign on examination, without any features of Albright’s hereditary osteodystrophy. Lab investigations revealed low calcium, high phosphate and high PTH levels. The patient was diagnosed as having Pseudohypoparathyroidism and he was treated successfully with Calcium and Vitamin D supplements. PMID:24298504

  16. Rare B Decays in BABAR

    SciTech Connect

    Hicheur, A

    2004-08-25

    Measurements and searches for rare B decays have been performed with the BaBar detector at the PEP-II e{sup +}e{sup -} asymmetric B Factory, operating at the {Upsilon}(4S) resonance. The authors report some recent branching fraction measurements on hadronic and radiative B decays, occurring from b --> s/d and b --> u transitions. Most of the results presented here are based on a data sample corresponding to a luminosity of 81.9 fb{sup -1}.

  17. Consumer preference for seeds and seedlings of rare species impacts tree diversity at multiple scales.

    PubMed

    Young, Hillary S; McCauley, Douglas J; Guevara, Roger; Dirzo, Rodolfo

    2013-07-01

    Positive density-dependent seed and seedling predation, where herbivores selectively eat seeds or seedlings of common species, is thought to play a major role in creating and maintaining plant community diversity. However, many herbivores and seed predators are known to exhibit preferences for rare foods, which could lead to negative density-dependent predation. In this study, we first demonstrate the occurrence of increased predation of locally rare tree species by a widespread group of insular seed and seedling predators, land crabs. We then build computer simulations based on these empirical data to examine the effects of such predation on diversity patterns. Simulations show that herbivore preferences for locally rare species are likely to drive scale-dependent effects on plant community diversity: at small scales these foraging patterns decrease plant community diversity via the selective consumption of rare plant species, while at the landscape level they should increase diversity, at least for short periods, by promoting clustered local dominance of a variety of species. Finally, we compared observed patterns of plant diversity at the site to those obtained via computer simulations, and found that diversity patterns generated under simulations were highly consistent with observed diversity patterns. We posit that preference for rare species by herbivores may be prevalent in low- or moderate-diversity systems, and that these effects may help explain diversity patterns across different spatial scales in such ecosystems.

  18. Rare Tumors in Children: Progress Through Collaboration

    PubMed Central

    Furman, Wayne L.; Schultz, Kris A.; Ferrari, Andrea; Helman, Lee; Krailo, Mark D.

    2015-01-01

    Rare pediatric tumors account for approximately 10% of all childhood cancers, which in themselves are a rare entity. The diverse histologies and clinical behaviors of rare pediatric tumors pose challenges to the investigation of their biologic and clinical features. National and international cooperative groups such as the Rare Tumor Committee of the Children's Oncology Group, Rare Tumors in Pediatric Age Project, and European Cooperative Study Group for Pediatric Rare Tumors have developed several initiatives to advance knowledge about rare pediatric cancers. However, these programs have been only partially effective, necessitating the development of alternative mechanisms to study these challenging diseases. In this article, we review the current national and international collaborative strategies to study rare pediatric cancers and alternative methods under exploration to enhance those efforts, such as independent registries and disease-specific, National Cancer Institute–sponsored clinics. PMID:26304909

  19. Miniaturized mitogenome of the parasitic plant Viscum scurruloideum is extremely divergent and dynamic and has lost all nad genes

    PubMed Central

    Skippington, Elizabeth; Barkman, Todd J.; Rice, Danny W.; Palmer, Jeffrey D.

    2015-01-01

    Despite the enormous diversity among parasitic angiosperms in form and structure, life-history strategies, and plastid genomes, little is known about the diversity of their mitogenomes. We report the sequence of the wonderfully bizarre mitogenome of the hemiparasitic aerial mistletoe Viscum scurruloideum. This genome is only 66 kb in size, making it the smallest known angiosperm mitogenome by a factor of more than three and the smallest land plant mitogenome. Accompanying this size reduction is exceptional reduction of gene content. Much of this reduction arises from the unexpected loss of respiratory complex I (NADH dehydrogenase), universally present in all 300+ other angiosperms examined, where it is encoded by nine mitochondrial and many nuclear nad genes. Loss of complex I in a multicellular organism is unprecedented. We explore the potential relationship between this loss in Viscum and its parasitic lifestyle. Despite its small size, the Viscum mitogenome is unusually rich in recombinationally active repeats, possessing unparalleled levels of predicted sublimons resulting from recombination across short repeats. Many mitochondrial gene products exhibit extraordinary levels of divergence in Viscum, indicative of highly relaxed if not positive selection. In addition, all Viscum mitochondrial protein genes have experienced a dramatic acceleration in synonymous substitution rates, consistent with the hypothesis of genomic streamlining in response to a high mutation rate but completely opposite to the pattern seen for the high-rate but enormous mitogenomes of Silene. In sum, the Viscum mitogenome possesses a unique constellation of extremely unusual features, a subset of which may be related to its parasitic lifestyle. PMID:26100885

  20. Ethical aspects on rare diseases.

    PubMed

    Barrera, Luis A; Galindo, Gilberto Cely

    2010-01-01

    In this chapter we discuss several of the most relevant subjects related to ethics on Rare Diseases. Some general aspects are discussed such as the socio-psychological problems that confront the patients and their families that finally lead to marginalization and exclusion of patients affected by these diseases from the health programs, even in wealthy countries. Then we address problems related to diagnosis and some ethical aspects of newborn screening, prenatal, pre-implantation diagnosis and reference centers, as well as some conditions that should be met by the persons and institutions performing such tasks. Alternatives of solutions for the most critical situations are proposed. Subsequently the orphan drugs subject is discussed not only from the availability point of view, prizes, industrial practices, and purchasing power in developed and developing societies. The research related to rare disease in children and other especially vulnerable conditions, the need for informed consent, review boards or ethics comities, confidentiality of the information, biobanks and pharmacogenetics are discussed.

  1. Rare earth garnet selective emitter

    NASA Technical Reports Server (NTRS)

    Lowe, Roland A.; Chubb, Donald L.; Farmer, Serene C.; Good, Brian S.

    1994-01-01

    Thin film Ho-YAG and Er-YAG emitters with a platinum substrate exhibit high spectral emittance in the emission band (epsilon(sub lambda) approximately equal to 0.74, ((4)l(sub 15/2)) - ( (4)l(sub13/2)), for Er-YAG and epsilon(sub lambda) approximately equal to 0.65, ((5)l(sub 7))-((5)l(sub 8)) for Ho-YAG) at excellent candidates for high efficiency selective emitters in the thermophotovoltaics (TPV) systems operating at moderate temperatures (1200-1500K). Spectral emittance measurements of the thin films were made (1.2 less than lambda less than 3.0 microns) and compared to the theoretical emittances calculated using measured values of the spectral extinction coefficient. In this paper we present the results for a new class of rare earth ion selective emitters. These emitters are thin sections (less than 1 mm) of yttrium aluminum garnet (YAG) single crystal with a rare earth substitutional impurity. This paper presents normal spectral emittance, epsilon(sub lambda), measurements of holmium (Ho), and erbium (Er) doped YAG thin film selective emitters at 1500 K, and compares those results with the theoretical spectral emittance.

  2. Scarcity of rare earth elements.

    PubMed

    de Boer, M A; Lammertsma, K

    2013-11-01

    Rare earth elements (REEs) are important for green and a large variety of high-tech technologies and are, therefore, in high demand. As a result, supply with REEs is likely to be disrupted (the degree of depends on the REE) in the near future. The 17 REEs are divided into heavy and light REEs. Other critical elements besides REEs, identified by the European Commission, are also becoming less easily available. Although there is no deficiency in the earth's crust of rare earth oxides, the economic accessibility is limited. The increased demand for REEs, the decreasing export from China, and geopolitical concerns on availability contributed to the (re)opening of mines in Australia and the USA and other mines are slow to follow. As a result, short supply of particularly terbium, dysprosium, praseodymium, and neodymium is expected to be problematic for at least the short term, also because they cannot be substituted. Recycling REEs from electronic waste would be a solution, but so far there are hardly any established REE recycling methods. Decreasing the dependency on REEs, for example, by identifying possible replacements or increasing their efficient use, represents another possibility.

  3. Purdue Rare Isotope Measurement Laboratory

    NASA Astrophysics Data System (ADS)

    Caffee, M.; Elmore, D.; Granger, D.; Muzikar, P.

    2002-12-01

    The Purdue Rare Isotope Measurement Laboratory (PRIME Lab) is a dedicated research and service facility for accelerator mass spectrometry. AMS is an ultra-sensitive analytical technique used to measure low levels of long-lived cosmic-ray-produced and anthropogenic radionuclides, and rare trace elements. We measure 10Be (T1/2 = 1.5 My), 26Al (.702 My), 36Cl (.301 My), and 129I (16 My), in geologic samples. Applications include dating the cosmic-ray-exposure time of rocks on Earth's surface, determining rock and sediment burial ages, measuring the erosion rates of rocks and soils, and tracing and dating ground water. We perform sample preparation and separation chemistries for these radio-nuclides for our internal research activities and for those external researchers not possessing this capability. Our chemical preparation laboratories also serve as training sites for members of the geoscience community developing these techniques at their institutions. Research at Purdue involves collaborators among members of the Purdue Departments of Physics, Earth and Atmospheric Sciences, Chemistry, Agronomy, and Anthropology. We also collaborate and serve numerous scientists from other institutions. We are currently in the process of modernizing the facility with the goals of higher precision for routinely measured radio-nuclides, increased sample throughput, and the development of new measurement capabilities for the geoscience community.

  4. 75 FR 47458 - TRICARE; Rare Diseases Definition

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-06

    ... Office of the Secretary 32 CFR Part 199 RIN 0720-AB26 TRICARE; Rare Diseases Definition AGENCY: Office of... diseases to adopt the definition of a rare disease as promulgated by the National Institutes of Health, Office of Rare Diseases. The rule modification will result in the definition used by the TRICARE...

  5. Rare Z decays and new physics

    SciTech Connect

    Glover, E.W.N.

    1990-04-01

    Although the signatures for rare Z decays are often spectacular, the predicted standard model rates are usually extremely small. In many cases, however, rare decays are very sensitive to new phenomena and may lead to an observable rate. In this talk, I select some interesting rare decays and discuss how new physics might be identified. 25 refs., 4 figs., 2 tabs.

  6. Restoration of rare earth mine areas: organic amendments and phytoremediation.

    PubMed

    Zhou, Lingyan; Li, Zhaolong; Liu, Wen; Liu, Shenghong; Zhang, Limin; Zhong, Liyan; Luo, Ximei; Liang, Hong

    2015-11-01

    Overexploitation of rare earth mine has caused serious desertification and various environmental issues, and ecological restoration of a mining area is an important concern in China. In this study, experiments involving dry grass landfilling, chicken manure broadcasting, and plant cultivation were carried out to reclaim a rare earth mine area located in Heping County, Guangdong Province, China. The prime focus was to improve soil quality in terms of nutrients, microbial community, enzyme activity, and physicochemical properties so as to reclaim the land. After 2 years of restoration, an increase of organic matter (OM), available potassium (K), available phosphorus (P) levels, and acid phosphatase (ACP) activity and a reduction of the available nitrogen (N) level and urease (URE) activity in soil were achieved compared to the original mined land. The nutrients and enzyme activities in soil with 5 years of restoration were close to or surpass those in the unexploited land as control. The bulk density, total porosity, water holding capacity, pH, and electrical conductivity (EC) of soil were improved, and the number of cultivable microorganisms and the bacterial diversity in soil were greatly increased with time during ecological restoration, especially for surface soil. Furthermore, the artificial vegetation stably grew at the restored mining sites. The results indicated that organic amendments and phytoremediation could ecologically restore the rare earth mining sites and the mined land could finally be planted as farmland.

  7. Rare earths, the lanthanides, yttrium and scandium

    USGS Publications Warehouse

    Hedrick, J.B.

    2006-01-01

    In 2005, rare earths were not mined in the United States. The major supplier, Molycorp, continued to maintain a large stockpile of rare-earth concentrates and compounds. Consumption decreased of refined rare-earth products. The United States remained a major importer and exporter of rare earths in 2005. During the same period, yttrium was not mined or refined in the US. Hence, supply of yttrium compounds for refined yttrium products came from China, France and Japan. Scandium was not also mined. World production was primarily in China, Russia and Ukraine. Demand for rare earths in 2006 is expected to be closely tied to economic conditions in the US.

  8. Mineral resource of the month: rare earths

    USGS Publications Warehouse

    Hedrick, James B.

    2004-01-01

    As if classified as a top-secret project, the rare earths have been shrouded in secrecy. The principal ore mineral of the group, bastnäsite, rarely appears in the leading mineralogy texts. The long names of the rare-earth elements and some unusual arrangements of letters, many Scandinavian in origin, may have intimidated even those skilled in phonics. Somewhat obscurely labeled, the rare earths are neither rare nor earths (the historical term for oxides). They are a relatively abundant group of metallic elements that occur in nature as nonmetallic compounds and have hundreds of commercial applications.

  9. Pollen limitation and inbreeding depression in an 'old rare' bumblebee-pollinated grassland herb.

    PubMed

    Becker, T; Voss, N; Durka, W

    2011-11-01

    Habitat fragmentation and reduction of population size have been found to negatively affect plant reproduction in 'new rare' species that were formerly common. This has been attributed primarily to effects of increased inbreeding but also to pollen limitation. In contrast, little is known about the reproduction of 'old rare' species that are naturally restricted to small and isolated habitats and thus may have developed strategies to cope with long-term isolation and small population size. Here we study the effects of pollen source and quantity on reproduction of the 'old rare' bumblebee-pollinated herb, Astragalus exscapus. In two populations of this species, we tested for pollen autodeposition, inbreeding depression and outbreeding depression. Caged plants were left unpollinated or were pollinated with pollen from the same plant, from the same population or from a distant population (50 km). Additionally, we tested for pollen limitation by pollen supplementation in four populations of different size and density. In the absence of pollinators, plants did not produce seed whereas self-pollinated plants did. This indicates a self-compatible breeding system dependent on insect pollination. Both self-pollination and, in one of the two populations, cross-pollination with pollen from plants from the distant population resulted in a lower number of seeds per flower than cross-pollination with pollen from plants from the resident population, indicating inbreeding and outbreeding depression. Pollen addition enhanced fruit set and number of seeds per flower in three of the four populations, indicating pollen limitation. The degree of pollen limitation was lowest in the smallest but densest population. Our results suggest that, similar to 'new rare' plant species, also 'old rare' species may be at risk of inbreeding depression and pollen limitation.

  10. Developments in rare earth intermetallics

    SciTech Connect

    Kirchmayr, H.R.

    1984-09-01

    The magnetic properties of rare earth intermetallics have been the subject of numerous investigations in recent years. However, while the preparation of new intermetallic compounds and the determination of their properties have been the prime concern in former years, more recently the analysis and theoretical explanation of the available data has become most important. Furthermore single crystals have now become available, which permit new experiments. Also many investigations on pseudo-binary systems have permitted the systematic determination of the primary magnetic properties. After a summary of the magnetic properties of intermetallics where the B-moment is zero and nonzero, some examples of pseudobinary systems and especially applications of R-3d multicomponent systems as the basis for advanced permanent magnets are discussed. Finally RE-3d alloys with metalloids and non-metals are discussed with emphasis on the newly developed R-Fe-B permanent magnets.

  11. Rare and radiative kaon decays

    NASA Astrophysics Data System (ADS)

    D’Ambrosio, Giancarlo

    2017-01-01

    We discuss theoretical issues in radiative rare kaon decays. The interest is twofold: to extract useful short-distance information and understand the underlying dynamics. We emphasize channels where either we can understand non-perturbative aspects of QCD or there is a chance to test the Standard Model. An interesting channel, K + → π + π 0 e + e ‑, is studied also in connection with the recent experimental NA48 results. Motivated by LHCB results on KS → μ + μ ‑ we discuss other channels like KS,L → l + l ‑ l + l ‑. Motivated by recent theoretical work by Buras and collaborators we study also the K ± → π±l + l ‑ form factor.

  12. Liposarcome dorsal: aspect clinique rare

    PubMed Central

    Agbessi, Odry; Arrob, Adil; Fiqhi, Kamal; Khalfi, Lahcen; Nassih, Mohammed; El Khatib, Karim

    2015-01-01

    Décrit la première fois par Virchow en 1860, le liposarcome est une tumeur mésenchymateuse rare. Cette rareté est relative car les liposarcomes représentent quand même 14 à 18% de l'ensemble des tumeurs malignes des parties molles et ils constituent le plus fréquent des sarcomes des parties molles. Pour la majorité des auteurs, il ne se développerait jamais sur un lipome ou une lipomatose préexistant. Nous rapportons un cas de volumineux liposarcome de la face dorsale du tronc. L'histoire de la maladie, l'aspect clinique inhabituel « de tumeur dans tumeur », l'aspect de la pièce opératoire nous fait évoquer la possibilité de la transformation maligne d'un lipome bénin préexistant. PMID:26113914

  13. Why are Pulsar Planets Rare?

    NASA Astrophysics Data System (ADS)

    Martin, Rebecca G.; Livio, Mario; Palaniswamy, Divya

    2016-12-01

    Pulsar timing observations have revealed planets around only a few pulsars. We suggest that the rarity of these planets is due mainly to two effects. First, we show that the most likely formation mechanism requires the destruction of a companion star. Only pulsars with a suitable companion (with an extreme mass ratio) are able to form planets. Second, while a dead zone (a region of low turbulence) in the disk is generally thought to be essential for planet formation, it is most probably rare in disks around pulsars, because of the irradiation from the pulsar. The irradiation strongly heats the inner parts of the disk, thus pushing the inner boundary of the dead zone out. We suggest that the rarity of pulsar planets can be explained by the low probability for these two requirements to be satisfied: a very low-mass companion and a dead zone.

  14. Epidemiological analysis of rare polydactylies

    SciTech Connect

    Castilla, E.E.; Fonseca, R.L. da; Dutra, M.G. da

    1996-11-11

    This work includes all cases with extra digits (polydactyly) registered from a birth sample of over four million births aggregated from two comparable birth series: the Latin-American Collaborative Study of Congenital Malformations: ECLAMC (3,128,957 live and still births from the 1967 to 1993 period), and the Spanish Collaborative Study of Congenital Malformations: ECEMC. All but 2 of 6,912 registered polydactyly cases fit well into one of the following 11 preestablished polydactyly types (observed number of cases in parentheses): Postaxial hexadactyly (5,345), Preaxial-I hexadactyly (1,018), Seven or more digits (57), synpolydactyly (15), crossed polydactyly (45), 1st digit triphalangism (33), 2nd digit duplication (39), 3rd digit duplication (18), 4th digit duplication (22), Haas polysyndactyly (3), and high degree of duplication (4). The birth prevalence rates observed in both series were similar except for postaxial polydactyly, which was more frequent in the ECLAMC (150.2/100,000) than in the ECEMC (67.4/100,000), as expected due to the higher African Black ethnic extraction of the South-American than of the Spanish populations. This similar frequency for the rare polydactylies (5.4 per 100,000 in South America and 5.7 in Spain), and for each one of the 9 categories, suggests that the values reported here are valid for most populations. The rare polydactylies are frequently syndromal: one third of them (77/236) were found in association with other congenital anomalies, 11.0% (26/236) in MCA cases and 21.6% (51/236) in recognized syndromes. 19 refs., 7 tabs.

  15. Rare Earth Element Mines, Deposits, and Occurrences

    USGS Publications Warehouse

    Orris, Greta J.; Grauch, Richard I.

    2002-01-01

    Data on rare earth (including yttrium) mines, deposits, and occurrences were compiled as part of an effort by the USGS and the University of Arizona Center for Mineral Resources to summarize current knowledge on the supply and demand outlook and related topics for this group of elements. Economic competition and environmental concerns are increasingly constraining the mining and processing of rare earths from the Mountain Pass mine in California. For many years, the deposit at Mountain Pass was the world's dominant source of rare earth elements and the United States was essentially self-sufficient. Starting approximately 10 years ago, the U.S. has become increasingly dependent (> 90 percent of separated rare earths) upon imports from China, now the dominant source of rare earths. A knowledge of the known economic and noneconomic sources of rare earths is basic to evaluating the outlook for rare earth supply and associated issues.

  16. Production method for making rare earth compounds

    DOEpatents

    McCallum, R.W.; Ellis, T.W.; Dennis, K.W.; Hofer, R.J.; Branagan, D.J.

    1997-11-25

    A method of making a rare earth compound, such as a earth-transition metal permanent magnet compound, without the need for producing rare earth metal as a process step, comprises carbothermically reacting a rare earth oxide to form a rare earth carbide and heating the rare earth carbide, a compound-forming reactant (e.g., a transition metal and optional boron), and a carbide-forming element (e.g., a refractory metal) that forms a carbide that is more thermodynamically favorable than the rare earth carbide whereby the rare earth compound (e.g., Nd{sub 2}Fe{sub 14}B or LaNi{sub 5}) and a carbide of the carbide-forming element are formed.

  17. Production method for making rare earth compounds

    DOEpatents

    McCallum, R. William; Ellis, Timothy W.; Dennis, Kevin W.; Hofer, Robert J.; Branagan, Daniel J.

    1997-11-25

    A method of making a rare earth compound, such as a earth-transition metal permanent magnet compound, without the need for producing rare earth metal as a process step, comprises carbothermically reacting a rare earth oxide to form a rare earth carbide and heating the rare earth carbide, a compound-forming reactant (e.g. a transition metal and optional boron), and a carbide-forming element (e.g. a refractory metal) that forms a carbide that is more thermodynamically favorable than the rare earth carbide whereby the rare earth compound (e.g. Nd.sub.2 Fe.sub.14 B or LaNi.sub.5) and a carbide of the carbide-forming element are formed.

  18. Rare earth elements: end use and recyclability

    USGS Publications Warehouse

    Goonan, Thomas G.

    2011-01-01

    Rare earth elements are used in mature markets (such as catalysts, glassmaking, lighting, and metallurgy), which account for 59 percent of the total worldwide consumption of rare earth elements, and in newer, high-growth markets (such as battery alloys, ceramics, and permanent magnets), which account for 41 percent of the total worldwide consumption of rare earth elements. In mature market segments, lanthanum and cerium constitute about 80 percent of rare earth elements used, and in new market segments, dysprosium, neodymium, and praseodymium account for about 85 percent of rare earth elements used. Regardless of the end use, rare earth elements are not recycled in large quantities, but could be if recycling became mandated or very high prices of rare earth elements made recycling feasible.

  19. Considering Plants.

    ERIC Educational Resources Information Center

    Flannery, Maura C.

    1991-01-01

    Examples from research that incorporate plants to illustrate biological principles are presented. Topics include dried pea shape, homeotic genes, gene transcription in plants that are touched or wounded, production of grasslands, seaweed defenses, migrating plants, camouflage, and family rivalry. (KR)

  20. Considering Plants.

    ERIC Educational Resources Information Center

    Flannery, Maura C.

    1991-01-01

    Examples from research that incorporate plants to illustrate biological principles are presented. Topics include dried pea shape, homeotic genes, gene transcription in plants that are touched or wounded, production of grasslands, seaweed defenses, migrating plants, camouflage, and family rivalry. (KR)

  1. Plant reproduction is altered by simulated herbicide drift toconstructed plant communities

    EPA Science Inventory

    Herbicide drift may have unintended impacts on native vegetation, adversely affecting structure and function of plant communities. However, these potential effects have been rarely studied or quantified. To determine potential ecological effects of herbicide drift, we construct...

  2. Tungsten Toxicity in Plants

    PubMed Central

    Adamakis, Ioannis-Dimosthenis S.; Panteris, Emmanuel; Eleftheriou, Eleftherios P.

    2012-01-01

    Tungsten (W) is a rare heavy metal, widely used in a range of industrial, military and household applications due to its unique physical properties. These activities inevitably have accounted for local W accumulation at high concentrations, raising concerns about its effects for living organisms. In plants, W has primarily been used as an inhibitor of the molybdoenzymes, since it antagonizes molybdenum (Mo) for the Mo-cofactor (MoCo) of these enzymes. However, recent advances indicate that, beyond Mo-enzyme inhibition, W has toxic attributes similar with those of other heavy metals. These include hindering of seedling growth, reduction of root and shoot biomass, ultrastructural malformations of cell components, aberration of cell cycle, disruption of the cytoskeleton and deregulation of gene expression related with programmed cell death (PCD). In this article, the recent available information on W toxicity in plants and plant cells is reviewed, and the knowledge gaps and the most pertinent research directions are outlined. PMID:27137642

  3. Plant conservation progress in the United States

    Treesearch

    Kayri Havens; Andrea Kramer; Ed. Guerrant

    2017-01-01

    Effective national plant conservation has several basic needs, including: 1) accessible, up-to-date information on species distribution and rarity; 2) research and management capacity to mitigate the impact of threats that make plants rare; 3) effective networks for conserving species in situ and ex situ; 4) education and training to make sure the right people are...

  4. Poisonous Plants. LC Science Tracer Bullet.

    ERIC Educational Resources Information Center

    Carter, Constance, Comp.

    There are a number of sources of information on the more than 700 species of plants, ferns, horsetails, and fungi that can cause toxic, though rarely fatal, reactions in humans and animals. This guide is intended for those who wish to review published materials on poisonous plants in the collections of the Library of Congress. It is not intended…

  5. Negative plant-soil feedbacks increase with plant abundance, and are unchanged by competition.

    PubMed

    Maron, John L; Laney Smith, Alyssa; Ortega, Yvette K; Pearson, Dean E; Callaway, Ragan M

    2016-08-01

    Plant-soil feedbacks and interspecific competition are ubiquitous interactions that strongly influence the performance of plants. Yet few studies have examined whether the strength of these interactions corresponds with the abundance of plant species in the field, or whether feedbacks and competition interact in ways that either ameliorate or exacerbate their effects in isolation. We sampled soil from two intermountain grassland communities where we also measured the relative abundance of plant species. In greenhouse experiments, we quantified the direction and magnitude of plant-soil feedbacks for 10 target species that spanned a range of abundances in the field. In soil from both sites, plant-soil feedbacks were mostly negative, with more abundant species suffering greater negative feedbacks than rare species. In contrast, the average response to competition for each species was unrelated with its abundance in the field. We also determined how competitive response varied among our target species when plants competed in live vs. sterile soil. Interspecific competition reduced plant size, but the strength of this negative effect was unchanged by plant-soil feedbacks. Finally, when plants competed interspecifically, we asked how conspecific-trained, heterospecific-trained, and sterile soil influenced the competitive responses of our target species and how this varied depending on whether target species were abundant or rare in the field. Here, we found that both abundant and rare species were not as harmed by competition when they grew in heterospecific-trained soil compared to when they grew in conspecific-cultured soil. Abundant species were also not as harmed by competition when growing in sterile vs. conspecific-trained soil, but this was not the case for rare species. Our results suggest that abundant plants accrue species-specific soil pathogens to a greater extent than rare species. Thus, negative feedbacks may be critical for preventing abundant species from

  6. Decline of a Rare Moth at Its Last Known English Site: Causes and Lessons for Conservation

    PubMed Central

    Baker, David; Barrett, Sinead; Beale, Colin M.; Crawford, Terry J.; Ellis, Sam; Gullett, Tallulah; Parsons, Mark S.; Relf, Penny; Robertson, Paul; Small, Julian; Wainwright, Dave

    2016-01-01

    The conditions required by rare species are often only approximately known. Monitoring such species over time can help refine management of their protected areas. We report population trends of a rare moth, the Dark Bordered Beauty Epione vespertaria (Linnaeus, 1767) (Lepidoptera: Geometridae) at its last known English site on a protected lowland heath, and those of its host-plant, Salix repens (L.) (Malpighiales: Salicaceae). Between 2007 and 2014, adult moth density reduced by an average of 30–35% annually over the monitored area, and its range over the monitored area contracted in concert. By comparing data from before this decline (2005) with data taken in 2013, we show that the density of host-plants over the monitored area reduced three-fold overall, and ten-fold in the areas of highest host-plant density. In addition, plants were significantly smaller in 2013. In 2005, moth larvae tended to be found on plants that were significantly larger than average at the time. By 2013, far fewer plants were of an equivalent size. This suggests that the rapid decline of the moth population coincides with, and is likely driven by, changes in the host-plant population. Why the host-plant population has changed remains less certain, but fire, frost damage and grazing damage have probably contributed. It is likely that a reduction in grazing pressure in parts of the site would aid host-plant recovery, although grazing remains an important site management activity. Our work confirms the value of constant monitoring of rare or priority insect species, of the risks posed to species with few populations even when their populations are large, of the potential conflict between bespoke management for species and generic management of habitats, and hence the value of refining our knowledge of rare species’ requirements so that their needs can be incorporated into the management of protected areas. PMID:27333285

  7. How to model rare events?

    NASA Astrophysics Data System (ADS)

    Grieser, J.; Jewson, S.

    2009-04-01

    The risk of extreme meteorological events is often estimated using extreme value theory (EVT). However, EVT can't be expected to work well in all cases. Two examples are (a) very rare events which are not adequately captured in short observational records and (b) nonstationary situations where observations alone cannot provide risk estimates for the future. For these reasons Risk Management Solutions (RMS) develops models of extreme weather risks that are based on a combination of both, physics and statistics, rather than just statistics. One example is the RMS TC-Rain model. In addition to wind and storm surge, tropical cyclones (TCs) can lead to torrential rain that may cause widespread flooding and landslides. The most prominent recent historical example is tropical storm Alison (2001) which inundated Houston and caused roughly US 5bn of damage. Since Alison was only tropical storm, rather than a hurricane, no damage due to wind and storm surge was expected and no serious warnings were issued. RMS now has developed a TC-Rain Model which is based on a combination of observations, experience and physical parameterizations. It is an example on how the use of physical principles helps to estimate the risk of rare and devastating events. Based on an event set of TC tracks it allows the calculation of several hundred thousand TC rain footprints which can then be used for the estimation of flood levels and their return periods via a complex dynamical hydrological model. The TC-Rain Model takes a number of physical mechanisms into account, including (a) the effect of surface roughness change at land fall, (b) orographic rain enhancement, (c) drift of rain due to strong horizontal winds, (d) asymmetry, (e) outer rain bands and (f) the dependence on sea surface temperature. It is calibrated using 35 US-landfalling tropical cyclones from 1998 to the 2008, and verified against all US-landfalling TCs since 1948. The model is not designed as a forecasting tool, but rather a

  8. Recycling of Rare Earth Elements

    NASA Astrophysics Data System (ADS)

    Lorenz, Tom; Bertau, Martin

    2017-01-01

    Any development of an effective process for rare earth (RE) recycling has become more and more challenging, especially in recent years. Since 2011, when commodity prices of REs had met their all-time maximum, prices have dropped rapidly by more than 90 %. An economic process able to offset these fluctuations has to take unconventional methods into account beside well-known strategies like acid/basic leaching or solvent extraction. The solid-state chlorination provides such an unconventional method for mobilizing RE elements from waste streams. Instead of hydrochloric acid this kind of chlorination decomposes NH4Cl thermally to release up to 400 °C hot HCl gas. After cooling the resulting solid metal chlorides may be easily dissolved in pH-adjusted water. Without producing strongly acidic wastes and with NH4Cl as cheap source for hydrogen chloride, solid-state chlorination provides various advantages in terms of costs and disposal. In the course of the SepSELSA project this method was examined, adjusted and optimized for RE recycling from fluorescent lamp scraps as well as Fe14Nd2B magnets. Thereby many surprising influences and trends required various analytic methods to examine the reasons and special mechanisms behind them.

  9. Pachyonychia congenita: A rare genodermatosis.

    PubMed

    Agarwal, Puneet; Chhaperwal, Mahendra K; Singh, Apurva; Verma, Arvind; Nijhawan, Manisha; Singh, Kishore; Mathur, Dinesh

    2013-07-01

    Pachyonychia congenita (PC) is a rare genodermatosis with only 450 cases reported since 1906. It is of two types, type I due to mutation in genes 6a and 16, and 6b and 17 in type II with an autosomal dominant inheritance in both types. A 22 yr old female patient presented in our OPD with hypertrophy of finger and toe nails, palmoplantar keratoderma, oral punctuate leukokeratosis, hyperhidrosis in palms and soles with maceration and malodour since childhood. She had a positive family history with father and grandfather affected but less severely. Microscopy and culture of nail clippings and scrapping were done to rule out fungal infection. On biopsy acanthotic epidermis, parakeratosis, orthokeratosis were seen. No evidence of any associated malignancy was found after thorough workup. She was diagnosed as PC Type 1. She was put on topical steroids and orally on acetretin 25 mg OD. Paring of the nails was done too reduce the thickness of nails & to provide symptomatic relief. She was on a regular treatment for 3-4 months and showed some improvement in the form of reduced palmoplantar hyperkeratosis and reduced oral punctate keratosis but was later lost on followup. She showed no adverse effect to therapy during this period. This case is being reported because of its rarity.

  10. Rare types of diabetes mellitus.

    PubMed

    Mihai, B; Mihai, Cătălina; Cijevschi-Prelipcean, Cristina; Lăcătuşu, Cristina

    2012-01-01

    Diabetes mellitus is a heterogenous disorder characterized by chronic hyperglycemia and induced by a large number of etiopathogenic conditions. Beside type 1 and type 2 diabetes, which account for almost 90% of all cases, practitioners may encounter patients with more infrequent forms of diabetes, as those induced by mutations of a single gene, atypical immune disorders or neonatal diabetes. Monogenic diabetes is represented by genetic disorders in the structure of the beta-cell (the MODY syndromes and the mutations of mitochondrial DNA) or in the insulin's action (type A insulin resistance syndrome, Rabson-Mendenhall syndrome, leprechaunism, lipodystrophies). The rare forms of immune diabetes are determined by antibodies against insulin or insulin receptor or appear as a component of the "stiff man syndrome". Neonatal diabetes is induced by mutations in genes that control beta-cell development and function and may have a transient or permanent nature. Knowledge of the uncommon forms of diabetes mellitus enables physicians to apply the optimal treatment, to estimate the evolution of the patient and to apply a complete family screening in order to diagnose all other blood relatives as soon as possible.

  11. Tale of two rare diseases

    PubMed Central

    Shukla, Ravindra; Basu, Asish Kumar; Mandal, Biplab; Mukhopadhyay, Pradip; Maity, Animesh; Sinha, Anirban

    2013-01-01

    Idiopathic Hypogonadotropic hypogonadism (IHH) phenotype is variable &various genes have been decribed in association with IHH. We describe association of IHH with mosaic trisomy 13. A 20 year old male presented with lack of development of secondary sexual characters, normal height, micropenis, small testes, gynaecomastia, absence of axillary and pubic hairs, hyposmia, synkinesis, bilateral horizontal nystagmus and high arched palate. Investigations showed low gonadotropin, low total testosterone, LH after stimulation with 100 mcg tryptorelin sc was 11.42 mU/mL at 40 min. MRI of hypothalamo-pituitary region showed normal olfactory bulb and tract but shallow olfactory sulcus. Karyotype showed homologous Robertsonian translocation of chromosome 13. This case fits classical IHH except for LH rise on stimulation. Features of Patau syndrome which is associated with trisomy 13 are absent in our case. Mosaic trisomy 13, which can otherwise be rare incidental finding, has not been described in association with IHH. Causal association of novel mutation on chromosome 13 leading to aforementioned phenotype cannot be rule out. PMID:24251138

  12. Rare adrenal tumors in children.

    PubMed

    Mihai, Radu

    2014-04-01

    Apart from neuroblastomas, adrenal tumors are exceedingly rare in children and young adults. In this age group, the vast majority of patients present with clinical signs associated with excess hormone production. The most common tumor to arise from the adrenal cortex is an adrenocortical carcinoma (ACC). Similar to the situation in adults, this tumor is frequently diagnosed at a late stage and carries a very poor prognosis. ACCs require extensive/aggressive local resection followed by mitotane chemotherapy. A multidisciplinary approach is essential, and these children should be referred to units that have previous experience in managing ACCs. International registries are an invaluable source for evidence-based care, and such collaborations should be further developed in the future. Pheochromocytomas are derived from the adrenal medulla and present with symptoms caused by high secretion of catecholamines. At least one-third of these children will be found to carry genetic mutations, most commonly the RET gene (MEN2 syndrome) or the VHL gene. Open radical adrenalectomy should be offered to children with adrenocortical cancers. For all other cases, laparoscopic adrenalectomy is the treatment of choice. It is possible that the retroperitoneoscopic approach will gain increasing favor. The role of robotic adrenalectomy remains controversial.

  13. Minimum memory for generating rare events

    NASA Astrophysics Data System (ADS)

    Aghamohammadi, Cina; Crutchfield, James P.

    2017-03-01

    We classify the rare events of structured, memoryful stochastic processes and use this to analyze sequential and parallel generators for these events. Given a stochastic process, we introduce a method to construct a process whose typical realizations are a given process' rare events. This leads to an expression for the minimum memory required to generate rare events. We then show that the recently discovered classical-quantum ambiguity of simplicity also occurs when comparing the structure of process fluctuations.

  14. Rare earths, the lanthanides, yttrium and scandium

    USGS Publications Warehouse

    Bedinger, G.; Bleiwas, D.

    2012-01-01

    In 2011, rare earths were recovered from bastnasite concentrates at the Mountain Pass Mine in California. Consumption of refined rare-earth products decreased in 2011 from 2010. U.S. rare-earth imports originated primarily from China, with lesser amounts from Austria, Estonia, France and Japan. The United States imported all of its demand for yttrium metal and yttrium compounds, with most of it originating from China. Scandium was imported in various forms and processed domestically.

  15. Improved method for preparing rare earth sesquichalcogenides

    DOEpatents

    Takeshita, T.; Beaudry, B.J.; Gschneidner, K.A. Jr.

    1982-04-14

    An improved method for the preparation of high purity rare earth sesquichalcogenides is described. The rare earth, as one or more pieces of the metal, is sealed under a vacuum with a stoichiometric amount of sulfur or selenium and a small amount of iodine into a quartz reaction vessel. The sealed vessel is then heated to above the vaporization temperature of the chalcogen and below the melting temperature of the rare earth metal and maintained until the product has been formed. The iodine is then vaporized off leaving a pure product. The rare earth sulfides and selenides thus formed are useful as semiconductors and as thermoelectric generators. 3 tables.

  16. Alaska's rare earth deposits and resource potential

    USGS Publications Warehouse

    Barker, James C.; Van Gosen, Bradley S.

    2012-01-01

    Alaska’s known mineral endowment includes some of the largest and highest grade deposits of various metals, including gold, copper and zinc. Recently, Alaska has also been active in the worldwide search for sources of rare earth elements (REE) to replace exports now being limitedby China. Driven by limited supply of the rare earths, combined with their increasing use in new ‘green’ energy, lighting, transportation, and many other technological applications, the rare earth metals neodymium, europium and, in particular, the heavy rare earth elements terbium, dysprosium and yttrium are forecast to soon be in critical short supply (U.S. Department of Energy, 2010).

  17. Mass Measurement with Rare-RI Rin

    NASA Astrophysics Data System (ADS)

    Ozawa, Akira

    2014-09-01

    Mass measurement with Rare-RI Ring in RIKEN RI Beam Factory (RIBF) will be presented. The main purpose of Rare-RI Ring is to measure the mass for very neutron-rich nuclei, the production rate of which is very small (rare RI) and the life-time of which is predicted to be very short (less than 10 ms). In Rare-RI Ring, mass measurements will be performed based on isochronous mass spectrometry. There are two innovative apparatus in Rare-RI Ring: individual injection, which can realize the injection of 200 A MeV rare RI one-by-one, and a cyclotron-like storage ring, which allows high isochronous magnetic fields with large angular and momentum acceptances (~1%). By these apparatus, we will achieve a 10-6 mass resolution, and will be able to access rare RI, the production rate of which is down to 1 event/day/pnA in RIBF. Construction of Rare-RI Ring has started from the 2012 fiscal year. Construction of the storage ring itself was almost completed. In this fiscal year, we succeeded to store alphas from 241Am source and to check the production of isochronous fields in the storage ring. In this talk, present status of Rare-RI Ring and the possible mass measurement there will be presented.

  18. [Rare diseases from a life insurance perspective].

    PubMed

    Senn, A; Filzmaier, K

    2015-12-01

    A rare disease is defined as a disease that affects a maximum of 5 in 10,000 people. As of today there are roughly 7000 different rare diseases known. On account of this one can say that "rare diseases are rare, but people affected by them are common". For Germany this amounts to: 4 million people that are affected by a rare disease. Diagnosis, therapeutic options and prognosis have substantially improved for some of the rare diseases. Besides the general medical advances--especially in the area of genetics--this is also due to networking and sharing information by so-called Centres of Competence on a national and international scale. This results in a better medical care for the corresponding group of patients. Against this backdrop, the number of people applying for life assurance who are suffering from a complex or rare disease has risen steadily in the last years. Due to the scarce availability of data regarding long-term prognosis of many rare diseases, a biomathematical, medical and actuarial expertise on the part of the insurer is necessary in order to adequately assess the risk of mortality and morbidity. Furthermore there is quite a focus on the issue of rare diseases from not only politics but society as well. Therefore evidence based medical assessment by insurers is especially important in this group of applicants--thinking of legal compliance and reputational risk.

  19. Rare Books As Teaching Tools

    NASA Astrophysics Data System (ADS)

    Gino, M. C.; Wise, G.

    2003-05-01

    The use of historic science illustrations in the classroom offers unique opportunities to meet the National Science Standard that "students should develop understanding of science as a human endeavor, of the nature of scientific knowledge, and of historical perspectives" (Content Standard G, Science Education Standards, 1996, National Academy Press, Washington, DC). The Dudley Observatory has launched an effort to use its outstanding collection of rare astronomy books to meet this challenge. The example featured here is the illustration "Systema Solare et Planetarium" from the book Atlas novus coelestis (1742) by Johann Gabriel Doppelmayr (1671-1750). This illustration is significant in the evolution of astronomy because it is one of the first popular depictions of the solar system picturing the planets in their accurate relative sizes and providing numerical estimates of planetary and solar dimensions and distances. Perhaps at least as important, from the educational viewpoint, it is visually appealing, culturally intriguing and filled with puzzling items that might serve as the basis for inquiry-based learning. For example, why is the page sprinkled with what appear to be appeals to theology ("Ex His Creatorem") and expressions of wonder or even horror ("perceptum horridem")? Why does its map of the world depict California as an island? A structure for using this and other historic illustrations in the classroom might be based on the following general questions: What is the purpose of the illustration? What is included that a modern scientist might leave out, or left out that a modern scientist might include? How accurate are the quantitative results presented? How does the conceptual treatment resemble and differ from modern treatments? Viewing the heavens as an 18th century astronomer wanted his public to see them is an excellent approach to achieving the humanistic and historical perspective that the educational standard seeks.

  20. A stochastic population model for Lepidium papilliferum (Brassicaceae), a rare desert ephemeral with a persistent seed bank

    Treesearch

    Susan E. Meyer; Dana Quinney; Jay Weaver

    2006-01-01

    Population viability analysis (PVA) is a valuable tool for rare plant conservation, but PVA for plants with persistent seed banks is difficult without reliable information on seed bank processes. We modeled the population dynamics of the Snake River Plains ephemeral Lepidium papilliferum using data from an 11-yr artificial seed bank experiment to estimate age-specific...

  1. [Research progress on plant diversity conservation in sand dune areas].

    PubMed

    Liu, Zhi-min; Ma, Jun-ling

    2008-01-01

    The landscape in sand dune areas is characterized by the alternate distribution of sand dune and interdune lowland, and the unique floras in these areas are some endemic or rare plant species. In recent years, the decrease in plant species richness and the disappearance of some endemic or rare plant species in these areas have been received special attention, which were listed in the Program of International Biodiversity Conservation, and studied in many countries and districts. In this paper, the research progress in these fields was summarized from the aspects of significance of plant diversity conservation, formation mechanisms of plant diversity, ways of plant diversity conservation, roles of plant diversity research in the development of ecological theories, and important issues in operating plant diversity conservation project. To conserve plant diversity in sand dune areas, attentions should be paid to the differences in conservation goals (to maintain high species richness or to conserve endemic or rare species) among different regions, and the balances between the stabilization of active sand and the conservation of endemic or rare species, and the maintenance of high species richness and the conservation of endemic or rare species. It needed also to consider the sand dune and the interdune lowland as a unified landscape unit to explore the impacts of disturbances and habitat fragment on plant diversity.

  2. Endangered, threatened, and rare vascular flora of the Savannah River Site

    SciTech Connect

    Knox, J.N.; Sharitz, R.R.

    1990-01-01

    This report summarizes information on the 30 endangered, threatened, or rare plants found on the Savannah River Site, Aiken, South Carolina. Of these 30 species, eight are under review by the US Fish and Wildlife Service as possible candidates for the proposed threatened and endangered list. Twenty-seven of the species are on the state of South Carolina's list prepared by the South Carolina Advisory Committee on Rare, Threatened, and Endangered Vascular Plants. These 27 plants include regionally threatened species, statewide threatened species, and rare species. Approximately two-thirds of these plants are found in wetland habitats. Also included in this report are summaries of 29 plant species that are likely to occur on the SRS, but have not been found there. Fourteen of these plants are on the federal list and range in status from endangered to possible candidates for deletion from the list. Twenty-eight are on the state of South Carolina list; approximately two-thirds of these also occur in wetland habitats. 31 refs., 45 figs., 2 tabs.

  3. Photoionization of rare gas clusters

    NASA Astrophysics Data System (ADS)

    Zhang, Huaizhen

    This thesis concentrates on the study of photoionization of van der Waals clusters with different cluster sizes. The goal of the experimental investigation is to understand the electronic structure of van der Waals clusters and the electronic dynamics. These studies are fundamental to understand the interaction between UV-X rays and clusters. The experiments were performed at the Advanced Light Source at Lawrence Berkeley National Laboratory. The experimental method employs angle-resolved time-of-flight photoelectron spectrometry, one of the most powerful methods for probing the electronic structure of atoms, molecules, clusters and solids. The van der Waals cluster photoionization studies are focused on probing the evolution of the photoelectron angular distribution parameter as a function of photon energy and cluster size. The angular distribution has been known to be a sensitive probe of the electronic structure in atoms and molecules. However, it has not been used in the case of van der Waals clusters. We carried out outer-valence levels, inner-valence levels and core-levels cluster photoionization experiments. Specifically, this work reports on the first quantitative measurements of the angular distribution parameters of rare gas clusters as a function of average cluster sizes. Our findings for xenon clusters is that the overall photon-energy-dependent behavior of the photoelectrons from the clusters is very similar to that of the corresponding free atoms. However, distinct differences in the angular distribution point at cluster-size-dependent effects were found. For krypton clusters, in the photon energy range where atomic photoelectrons have a high angular anisotropy, our measurements show considerably more isotropic angular distributions for the cluster photoelectrons, especially right above the 3d and 4p thresholds. For the valence electrons, a surprising difference between the two spin-orbit components was found. For argon clusters, we found that the

  4. Discovery of rare variants for complex phenotypes.

    PubMed

    Kosmicki, Jack A; Churchhouse, Claire L; Rivas, Manuel A; Neale, Benjamin M

    2016-06-01

    With the rise of sequencing technologies, it is now feasible to assess the role rare variants play in the genetic contribution to complex trait variation. While some of the earlier targeted sequencing studies successfully identified rare variants of large effect, unbiased gene discovery using exome sequencing has experienced limited success for complex traits. Nevertheless, rare variant association studies have demonstrated that rare variants do contribute to phenotypic variability, but sample sizes will likely have to be even larger than those of common variant association studies to be powered for the detection of genes and loci. Large-scale sequencing efforts of tens of thousands of individuals, such as the UK10K Project and aggregation efforts such as the Exome Aggregation Consortium, have made great strides in advancing our knowledge of the landscape of rare variation, but there remain many considerations when studying rare variation in the context of complex traits. We discuss these considerations in this review, presenting a broad range of topics at a high level as an introduction to rare variant analysis in complex traits including the issues of power, study design, sample ascertainment, de novo variation, and statistical testing approaches. Ultimately, as sequencing costs continue to decline, larger sequencing studies will yield clearer insights into the biological consequence of rare mutations and may reveal which genes play a role in the etiology of complex traits.

  5. [The observatory of rare malignant gynecologic tumors].

    PubMed

    Devouassoux-Shisheboran, Mojgan; Vacher-Lavenu, Marie-Cécile

    2014-02-01

    The observatory of gynecological rare tumors (TMRG) has been initially created for ovarian rare neoplasms (TMRO). Because of the similarities between ovarian and other gynecological tumors, this observatory has been then extended to all gynecological rare tumors. The recognition by INCa of three national expert centers (centre Léon-Bérard, hôpitaux de Paris, institut Gustave-Roussy) in rare gynecological cancers and a network of regional expert centers in 2010, expend the experience of the website "Observatoire francophone des tumeurs rares de l'ovaire". The major goals of this gynecology rare tumors experts network, are to promote systematic second opinion for initial diagnostic by experts in gynecopathology, systematic multidisciplinary advice by surgeons and medical oncologist experts, to disseminate clinical guidelines dedicated to rare gynecological tumors, to promote specific fundamental and translational research within clinical trials dedicated to rare tumors. At the end, we would like to improve benefit in term of survival and/or fertility for all these potential young patients.

  6. Rare Malignant Tumors of the Breast

    PubMed Central

    Miller, Trevor; Albarracin, Constance; Carkaci, Selin; Whitman, Gary J; Adrada, Beatriz E

    2015-01-01

    While the more common forms of breast cancer are well understood and recognized, there are many important rare malignancies that are less appreciated. Many of these cancers have imaging findings that, when understood, help to formulate a more educated differential diagnosis. In this article, the clinical features, imaging, and pathologic findings of rare breast malignancies will be discussed. PMID:26664775

  7. Rare Malignant Tumors of the Breast.

    PubMed

    Miller, Trevor; Albarracin, Constance; Carkaci, Selin; Whitman, Gary J; Adrada, Beatriz E

    2015-01-01

    While the more common forms of breast cancer are well understood and recognized, there are many important rare malignancies that are less appreciated. Many of these cancers have imaging findings that, when understood, help to formulate a more educated differential diagnosis. In this article, the clinical features, imaging, and pathologic findings of rare breast malignancies will be discussed.

  8. Ames Lab 101: Rare-Earth Recycling

    ScienceCinema

    Ryan Ott

    2016-07-12

    Recycling keeps paper, plastics, and even jeans out of landfills. Could recycling rare-earth magnets do the same? Perhaps, if the recycling process can be improved. Scientists at the U.S. Department of Energy's Ames Laboratory are working to more effectively remove the neodymium, a rare earth, from the mix of other materials in a magnet.

  9. Ames Lab 101: Rare-Earth Recycling

    SciTech Connect

    Ryan Ott

    2012-09-05

    Recycling keeps paper, plastics, and even jeans out of landfills. Could recycling rare-earth magnets do the same? Perhaps, if the recycling process can be improved. Scientists at the U.S. Department of Energy's Ames Laboratory are working to more effectively remove the neodymium, a rare earth, from the mix of other materials in a magnet.

  10. Ternary rare earth-lanthanide sulfides

    DOEpatents

    Takeshita, Takuo; Gschneidner JR., Karl A.; Beaudry, Bernard J.

    1987-01-06

    A new ternary rare earth sulfur compound having the formula: where M is a rare earth element selected from the group europium, samarium and ytterbium and x=0.15 to 0.8. The compound has good high-temperature thermoelectric properties and exhibits long-term structural stability up to 1000.degree. C.

  11. Advances in rare earth spectroscopy and applications.

    PubMed

    Dwivedi, Y; Zilio, S C

    2014-02-01

    Rare earth (RE) elements are prime constituents in a large amount of innovative materials and several technological advances would not be possible without their contribution. In this review, recent progress in the field of rare earth spectroscopy is highlighted, with a special emphasis on clean energy, sensors and telecommunications, providing a broad view on past and recent developments.

  12. [RARE DISEASES DTC: DIAGNOSIS, TREATMENT AND CARE].

    PubMed

    Mendlovic, Joseph; Barash, Hila; Yardeni, Hadar; Banet-Levi, Yonit; Yonath, Hagith; Raas-Rothschild, Annick

    2016-04-01

    Rare diseases are chronic, progressive genetic disorders, which affect around 6-8% of the general population, mainly children. Therefore, in Israel approximately 500,000 people are probably affected by a rare disease. In this article, we review some of the issues pertaining to rare diseases, such as the need for accurate diagnosis which is necessary not only for specific care and treatment but also for informed family planning. In addition, we review the impact of the activities of patients' organizations on the awareness of rare diseases and their involvement in the creation of the Orphan Drug Act, which was the leading point on the way to drug development worldwide. During the last few years networks for reaching leading specialists' opinions on the way to proper diagnosis were created. Thereafter, the next generation genetic technologies, such as exome sequencing, have been a revolution in terms of options and hope for patients with rare undiagnosed diseases. Patients with rare diseases and their families are a challenge to the health care system, not only in terms of diagnosis and therapy, but also in terms of special needs. In addition, deciphering molecular pathways of rare diseases might be the key for understanding molecular events involved in common disorders. We emphasize the duty to ensure appropriate capacity and equal access to follow-up and clinical management of patients with rare diseases in Israel.

  13. RARE EARTH ELEMENT IMPACTS ON BIOLOGICAL WASTEWATER TREATMENT

    SciTech Connect

    Fujita, Y.; Barnes, J.; Fox, S.

    2016-09-01

    Increasing demand for rare earth elements (REE) is expected to lead to new development and expansion in industries processing and or recycling REE. For some industrial operators, sending aqueous waste streams to a municipal wastewater treatment plant, or publicly owned treatment works (POTW), may be a cost effective disposal option. However, wastewaters that adversely affect the performance of biological wastewater treatment at the POTW will not be accepted. The objective of our research is to assess the effects of wastewaters that might be generated by new rare earth element (REE) beneficiation or recycling processes on biological wastewater treatment systems. We have been investigating the impact of yttrium and europium on the biological activity of activated sludge collected from an operating municipal wastewater treatment plant. We have also examined the effect of an organic complexant that is commonly used in REE extraction and separations; similar compounds may be a component of newly developed REE recycling processes. Our preliminary results indicate that in the presence of Eu, respiration rates for the activated sludge decrease relative to the no-Eu controls, at Eu concentrations ranging from <10 to 660 µM. Yttrium appears to inhibit respiration as well, although negative impacts have been observed only at the highest Y amendment level tested (660 µM). The organic complexant appears to have a negative impact on activated sludge activity as well, although results are variable. Ultimately the intent of this research is to help REE industries to develop environmentally friendly and economically sustainable beneficiation and recycling processes.

  14. Rare Earth Metals: Resourcefulness and Recovery

    NASA Astrophysics Data System (ADS)

    Wang, Shijie

    2013-10-01

    When we appreciate the digital revolution carried over from the twentieth century with mobile communication and the Internet, and when we enjoy our high-tech lifestyle filled with iDevices, hybrid cars, wind turbines, and solar cells in this new century, we should also appreciate that all of these advanced products depend on rare earth metals to function. Although there are only 136,000 tons of annual worldwide demand, (Cho, Rare Earth Metals, Will We Have Enough?)1 rare earth metals are becoming such hot commodities on international markets, due to not only to their increasing uses, including in most critical military hardware, but also to Chinese growth, which accounts for 95% of global rare earth metal production. Hence, the 2013 technical calendar topic, planned by the TMS/Hydrometallurgy and Electrometallurgy Committee, is particularly relevant, with four articles (including this commentary) contributed to the JOM October Issue discussing rare earth metals' resourcefulness and recovery.

  15. Projections of suitable habitat for rare species under global warming scenarios

    Treesearch

    F. Thomas Ledig; Gerald E. Rehfeldt; Cuauhtemoc Saenz-Romero; Flores-Lopez Celestino

    2010-01-01

    Premise of the study: Modeling the contemporary and future climate niche for rare plants is a major hurdle in conservation, yet such projections are necessary to prevent extinctions that may result from climate change. Methods: We used recently developed spline climatic models and modifi ed Random Forests...

  16. Distributions of rare mollusks relative to reserved lands in northern California

    Treesearch

    Jeffrey Dunk; William Zielinski; Karen West; Kristin Schmidt; Jim Baldwin; Julie Perrochet; Kary Schlick; Jan. Ford

    2002-01-01

    In 1994 the Northwest Forest Plan identified several hundred relatively rare plant and animal species  as "Survey and Manage" based in part on their presumed association with late-succesional/old-growth forests. Other such species were given protection from grazing. However, broad-scale surveys for few of these species existed at that time....

  17. Poisonous Plants

    MedlinePlus

    ... Publications and Products Programs Contact NIOSH NIOSH POISONOUS PLANTS Recommend on Facebook Tweet Share Compartir Photo courtesy ... U.S. Department of Agriculture Many native and exotic plants are poisonous to humans when ingested or if ...

  18. Nature plants.

    PubMed

    2014-06-01

    We welcome our new sister journal Nature Plants and the increased commitment to the plant science community that it represents. This is an opportunity for Nature Genetics to emphasize the use of genetic and genomic tools and resources in discovering new plant biology and solving major agricultural challenges.

  19. Medicinal Plants.

    ERIC Educational Resources Information Center

    Phillipson, J. David

    1997-01-01

    Highlights the demand for medicinal plants as pharmaceuticals and the demand for health care treatments worldwide and the issues that arise from this. Discusses new drugs from plants, anticancer drugs, antiviral drugs, antimalarial drugs, herbal remedies, quality, safety, efficacy, and conservation of plants. Contains 30 references. (JRH)

  20. Hardwood planting

    Treesearch

    Richard M. Godman

    1992-01-01

    Hardwood planting used to be most common on private land. Now more and more hardwoods are being planted on public land. Not much hardwood planting research is going on but recent summaries of earlier trials allow us to give you the following guidelines.

  1. Medicinal Plants.

    ERIC Educational Resources Information Center

    Phillipson, J. David

    1997-01-01

    Highlights the demand for medicinal plants as pharmaceuticals and the demand for health care treatments worldwide and the issues that arise from this. Discusses new drugs from plants, anticancer drugs, antiviral drugs, antimalarial drugs, herbal remedies, quality, safety, efficacy, and conservation of plants. Contains 30 references. (JRH)

  2. Mouse Models of Rare Craniofacial Disorders.

    PubMed

    Achilleos, Annita; Trainor, Paul A

    2015-01-01

    A rare disease is defined as a condition that affects less than 1 in 2000 individuals. Currently more than 7000 rare diseases have been documented, and most are thought to be of genetic origin. Rare diseases primarily affect children, and congenital craniofacial syndromes and disorders constitute a significant proportion of rare diseases, with over 700 having been described to date. Modeling craniofacial disorders in animal models has been instrumental in uncovering the etiology and pathogenesis of numerous conditions and in some cases has even led to potential therapeutic avenues for their prevention. In this chapter, we focus primarily on two general classes of rare disorders, ribosomopathies and ciliopathies, and the surprising finding that the disruption of fundamental, global processes can result in tissue-specific craniofacial defects. In addition, we discuss recent advances in understanding the pathogenesis of an extremely rare and specific craniofacial condition known as syngnathia, based on the first mouse models for this condition. Approximately 1% of all babies are born with a minor or major developmental anomaly, and individuals suffering from rare diseases deserve the same quality of treatment and care and attention to their disease as other patients. © 2015 Elsevier Inc. All rights reserved.

  3. [Global strategy for rare and intractable diseases].

    PubMed

    Kawashima Kodama, Tomoko

    2013-01-01

    The progress has been made in research on rare and intractable diseases, for which new drug development has long been limited due to rarity, by establishing a global network in recent years. In Japan, the countermeasure of rare and intractable diseases has been implemented under national policy outline as an integrated strategy since 1972, including surveys and research, construction of medical facilities, reducing burden of medical expenses for patients, and enhancement of welfare and improving QOL of patients. Along with legislation or regulation of orphan drugs development, treatment and care for rare diseases have been emphasized in each national healthcare system globally. In the US, the Office of Rare Diseases was established under NIH in 1989 and European countries also started collaboration for rare disease projects with their own national plans in 1999. As a platform of rare diseases patients, healthcare professionals, researchers, pharmaceutical industry, and policy makers, Orphanet has a well-designed website which networks them. In Japan, there are urgent needs for global standard patient registration system and strengthening global collaboration for developing treatment and care for the patients of rare and intractable diseases, which needs more cooperative relations with patient organizations and pharmaceutical industry within country.

  4. Taxonomy of rare genetic metabolic bone disorders.

    PubMed

    Masi, L; Agnusdei, D; Bilezikian, J; Chappard, D; Chapurlat, R; Cianferotti, L; Devolgelaer, J-P; El Maghraoui, A; Ferrari, S; Javaid, M K; Kaufman, J-M; Liberman, U A; Lyritis, G; Miller, P; Napoli, N; Roldan, E; Papapoulos, S; Watts, N B; Brandi, M L

    2015-10-01

    This article reports a taxonomic classification of rare skeletal diseases based on metabolic phenotypes. It was prepared by The Skeletal Rare Diseases Working Group of the International Osteoporosis Foundation (IOF) and includes 116 OMIM phenotypes with 86 affected genes. Rare skeletal metabolic diseases comprise a group of diseases commonly associated with severe clinical consequences. In recent years, the description of the clinical phenotypes and radiographic features of several genetic bone disorders was paralleled by the discovery of key molecular pathways involved in the regulation of bone and mineral metabolism. Including this information in the description and classification of rare skeletal diseases may improve the recognition and management of affected patients. IOF recognized this need and formed a Skeletal Rare Diseases Working Group (SRD-WG) of basic and clinical scientists who developed a taxonomy of rare skeletal diseases based on their metabolic pathogenesis. This taxonomy of rare genetic metabolic bone disorders (RGMBDs) comprises 116 OMIM phenotypes, with 86 affected genes related to bone and mineral homeostasis. The diseases were divided into four major groups, namely, disorders due to altered osteoclast, osteoblast, or osteocyte activity; disorders due to altered bone matrix proteins; disorders due to altered bone microenvironmental regulators; and disorders due to deranged calciotropic hormonal activity. This article provides the first comprehensive taxonomy of rare metabolic skeletal diseases based on deranged metabolic activity. This classification will help in the development of common and shared diagnostic and therapeutic pathways for these patients and also in the creation of international registries of rare skeletal diseases, the first step for the development of genetic tests based on next generation sequencing and for performing large intervention trials to assess efficacy of orphan drugs.

  5. Novel Fiber Preforms: Rare Earth Doping.

    DTIC Science & Technology

    1988-01-21

    measurements were made on a Digilab FTS-15B as KBr While there are many complex multicomponent rare pellets from 3800-4(0cm and as low density poivethvene...earth glasses, phosphates hold special interest as binary pellets t50-500cm ). Spectral resolution was 2 cm- cr rare earth glasses of variable composition...SiO- the glasses have compositions in the range x = 0.009 to 0052. w.hich corresponds to 0.9 to 5.2 molo or up to 23 wt% rare earth oxide as determruned

  6. Cardiac Plasmacytoma: A Rare Clinical Entity

    PubMed Central

    Vrettou, Agathi-Rosa; Heffner, L. Thompson; Rossi, Peter J.

    2014-01-01

    Primary malignant cardiac tumors are rare. Among these tumors, cardiac plasmacytoma is extremely rare and is the subject of few case reports. We present the case of a 73-year-old man who had isolated cardiac plasmacytoma 26 years after successful treatment of an axillary plasmacytoma. Multiple imaging methods—including echocardiography, cardiac magnetic resonance, and positron-emission tomography/computed tomography—were valuable and complementary to each other in this patient's diagnosis and optimal management. His case illustrates the use of these techniques in the successful diagnosis and treatment of a rare clinical entity, cardiac plasmacytoma. PMID:25425995

  7. Cardiac plasmacytoma: a rare clinical entity.

    PubMed

    Vrettou, Agathi-Rosa; Heffner, L Thompson; Rossi, Peter J; Clements, Stephen D

    2014-10-01

    Primary malignant cardiac tumors are rare. Among these tumors, cardiac plasmacytoma is extremely rare and is the subject of few case reports. We present the case of a 73-year-old man who had isolated cardiac plasmacytoma 26 years after successful treatment of an axillary plasmacytoma. Multiple imaging methods-including echocardiography, cardiac magnetic resonance, and positron-emission tomography/computed tomography-were valuable and complementary to each other in this patient's diagnosis and optimal management. His case illustrates the use of these techniques in the successful diagnosis and treatment of a rare clinical entity, cardiac plasmacytoma.

  8. Ecology and exploration of the rare biosphere.

    PubMed

    Lynch, Michael D J; Neufeld, Josh D

    2015-04-01

    The profound influence of microorganisms on human life and global biogeochemical cycles underlines the value of studying the biogeography of microorganisms, exploring microbial genomes and expanding our understanding of most microbial species on Earth: that is, those present at low relative abundance. The detection and subsequent analysis of low-abundance microbial populations—the 'rare biosphere'—have demonstrated the persistence, population dynamics, dispersion and predation of these microbial species. We discuss the ecology of rare microbial populations, and highlight molecular and computational methods for targeting taxonomic 'blind spots' within the rare biosphere of complex microbial communities.

  9. Autoluminescent Plants

    PubMed Central

    Krichevsky, Alexander; Meyers, Benjamin; Vainstein, Alexander; Maliga, Pal; Citovsky, Vitaly

    2010-01-01

    Prospects of obtaining plants glowing in the dark have captivated the imagination of scientists and layman alike. While light emission has been developed into a useful marker of gene expression, bioluminescence in plants remained dependent on externally supplied substrate. Evolutionary conservation of the prokaryotic gene expression machinery enabled expression of the six genes of the lux operon in chloroplasts yielding plants that are capable of autonomous light emission. This work demonstrates that complex metabolic pathways of prokaryotes can be reconstructed and function in plant chloroplasts and that transplastomic plants can emit light that is visible by naked eye. PMID:21103397

  10. Plant nanotoxicology.

    PubMed

    Dietz, Karl-Josef; Herth, Simone

    2011-11-01

    The anthropogenic release of nanoparticles (NPs) to the environment poses a potential hazard to human health and life. The interplay between NPs and biological processes is receiving increasing attention. Plants expose huge interfaces to the air and soil environment. Thus, NPs are adsorbed to the plant surfaces, taken up through nano- or micrometer-scale openings of plants and are translocated within the plant body. Persistent NPs associated with plants enter the human food chain. In this Opinion, we document the occurrence and character of NPs in the environment and evaluate the need for future research on toxicological effects. Plant nanotoxicology is introduced as a discipline that explores the effects and toxicity mechanisms of NPs in plants, including transport, surface interactions and material-specific responses. Copyright © 2011 Elsevier Ltd. All rights reserved.

  11. Rarely reported fungal spores and structures: An overlooked source of probative trace evidence in criminal investigations.

    PubMed

    Hawksworth, David L; Wiltshire, Patricia E J; Webb, Judith A

    2016-07-01

    The value of pollen and plant spores as trace evidence has long been established, but it is only in the last eight years that fungal spores have been analysed routinely from the same palynological samples. They have greatly enhanced the specificity of links between people, objects, and places. Most fungal species occupy restricted ecological niches and their distributions can be limited both spatially and geographically. Spores may be dispersed over very short distances from the fungal sporophore,(1) and their presence in any palynological assemblage may indicate a restricted area of ground, or the presence of particular plants (even specific dead plant material). Fungal spores can represent primary, secondary, or even tertiary proxy evidence of a location, and can indicate the presence of a plant even though the plant is not obvious at a crime scene. In some cases, spores from fungi which have rarely been reported, and are considered to be rare, have been of particular value in providing intelligence or evidence of contact. Ten examples are given from case work in which rarely reported or unusual fungi have proved to be important in criminal investigations.

  12. Rare-earth isotopes as tracers of particulate emissions: An urban scale test. Final report

    SciTech Connect

    Ondov, J.M.; Kelly, W.R.; Holland, J.Z.; Lin, Z.C.; Wight, S.A.

    1991-01-01

    The particulate emissions of a 100 MW(e) coal-fired power plant were successfully tagged with enriched rare-earth isotopes on three occasions during the month of August, 1988. On 28 August, an 8-hour release was made using 94% isotopically pure 148Nd injected at a rate of 61 mg/hr and 14 ambient aerosol samples collected along a 72 degree arc 20-km distant from the plant were analyzed by pulse-counting thermal-ionization mass spectrometry for excess 148Nd and naturally-occurring (total) Nd background. The results were in good agreement with Gaussian plume model predictions. We conclude that the experiment and preliminary results successfully demonstrate the feasibility of using an enriched rare-earth isotopes as tracers of emissions from coal-fired power plants. The large signal-to-noise ratios achieved here are sufficient for tracing particles over much larger distances.

  13. Assessing and Mitigating the Effects of Windblown Soil on Rare and Common Vegetation

    NASA Astrophysics Data System (ADS)

    Gleason, Sean M.; Faucette, Dave T.; Toyofuku, Mai M.; Torres, Carlos A.; Bagley, Calvin F.

    2007-12-01

    Acting under the auspices of the US Endangered Species Act, we quantified wind erosion and its effects on rare and common plant species on a semi-arid military installation in Hawaii. Our goal was to develop management strategies, based on local data, to aid the conservation of rare and common indigenous plants and their habitats. We collected windblown soil coming off of roads and other disturbed soils to assess likely impacts to plants occurring at certain heights and distances from disturbed surfaces. We then subjected plants in a glasshouse to windblown dust treatments, designed from our field data to simulate erosion events, and evaluated the effect of these treatments on photosynthesis and survival. We also designed several field experiments to examine the in-situ effects of windblown soil and soil substrate on germination, growth rate, and survival of indigenous and nonindigenous plants. We conclude from these experiments that most direct effects of windblown soil to plants can be effectively mitigated by locating roads and training areas at least 40 m from sensitive plant habitats and through vegetation management to maintain at least 11% aerial cover on disturbed surfaces. Effects of soil type on germination, growth, and survival was species-specific, emphasizing the importance of species trials prior to, or during, rehabilitation efforts.

  14. [Selective Isolation of Rare Actinomycetes from Soil].

    PubMed

    Sineva, O N; Terekhova, L P

    2015-01-01

    Many diverse methods for selective isolation of actinomycetes are used in discovery of organisms producing biologically active substances, as well as in ecological studies. Methods for isolation of rare actinomycetes from soil are reviewed.

  15. Urolithiasis with penile erection: a rare presentation.

    PubMed

    Wu, Bing; Xing, Yue

    2012-06-01

    Urinary stones are rarely seen in the urethra and are usually encountered in men with urethral stricture or infection. We describe a unique case of giant impacted stones in a 20-year-old man with unreal penile erection.

  16. International Rare Histiocytic Disorders Registry (IRHDR)

    ClinicalTrials.gov

    2016-04-25

    Rare Histiocytic Disorders (RHDs); Juvenile Xanthogranuloma (JXG); Reticulohistiocytoma (Epithelioid Histiocytoma); Xanthoma Disseminatum (XD); Multicentric Reticulohistiocytosis (MRH); Systemic Juvenile Xanthogranuloma; Erdheim-Chester Disease (ECD); Multi-system Rosai-Dorfman Disease (RDD)

  17. Sirenomelia with oesophageal atresia: a rare association.

    PubMed

    Sathe, Pragati Aditya; Ghodke, Ratnaprabha Kundlikrao; Kandalkar, Bhuvaneshwari Mahendra

    2014-02-01

    We are reporting a rare case of sirenomelia with oesophageal atresia. Sirenomelia is a lethal sporadic defect of which lower gastrointestinal tract anomalies are characteristic findings. Respiratory and upper gastrointestinal tract malformations like oesophageal atresia occur in about 20-35% of cases. Though its occurrence has been described, it has been reported only rarely. This report aims at describing this uncommon association along with its histological features.

  18. Ternary rare earth-lanthanide sulfides

    DOEpatents

    Takeshita, Takuo; Gschneidner, Jr., Karl A.; Beaudry, Bernard J.

    1987-01-06

    A new ternary rare earth sulfur compound having the formula: La.sub.3-x M.sub.x S.sub.4 where M is a rare earth element selected from the group europium, samarium and ytterbium and x=0.15 to 0.8. The compound has good high-temperature thermoelectric properties and exhibits long-term structural stability up to 1000.degree. C.

  19. A rare presentation of an acute appendicitis

    PubMed Central

    Kordzadeh, Ali; Lorenzi, Bruno; Kalyan, Jiten P.; Hanif, Muhammad A.; Charalabopoulos, Alexandros

    2017-01-01

    Paraumbilical hernia sac usually contains omentum, bowel loop and rarely appendicular epiploicae, metastatic deposits and vermiform appendix. Presentation of acute appendicitis in a paraumbilical hernia is rare and limited to few case reports in the literature. Herein, we would like to report a case of a successfully treated acute appendicitis presenting in a paraumbilical hernia in an 84-year-old lady with 6-month follow-up. PMID:28096326

  20. Pediatric vasitis: A rare complication of epididymitis

    PubMed Central

    Schurr, Efrat; Cytter-Kuint, Ruth; Ehrlichman, Matityahu; Weiser, Giora

    2014-01-01

    Vasitis represents an inflammation of the vas deferens. This is a rare entity seen mostly in adult males following local surgery (e.g., vasectomy, hernia repair). Children with groin masses have a wide differential diagnosis. We describe a child with a groin mass following epididymitis diagnosed with vasitis and review the known literature regarding diagnostic tools and treatment. Vasitis in children, although rare, can be seen as a complication of epididymitis. PMID:25024800

  1. Hemorrhagic sarcoid pleural effusion: A rare entity

    PubMed Central

    Jha, Onkar; Nair, Vidya; Talwar, Deepak

    2016-01-01

    Involvement of pleura by sarcoidosis remains a rare manifestation and varies from pleural effusion, pneumothorax, pleural thickening, hydropneumothorax, trapped lung, hemothorax, or chylothorax. Sarcoid pleural effusions presenting as hemorrhagic effusions are even more rare. We report a case of active pulmonary sarcoidosis presenting as hemorrhagic pleural effusion requiring tissue diagnosis to rule out malignancy. The rarity of the presentation prompted us to report this case. PMID:27625449

  2. Rare thyroid non-neoplastic diseases.

    PubMed

    Lacka, Katarzyna; Maciejewski, Adam

    2015-01-01

    Rare diseases are usually defined as entities affecting less than 1 person per 2,000. About 7,000 different rare entities are distinguished and, among them, rare diseases of the thyroid gland. Although not frequent, they can be found in the everyday practice of endocrinologists and should be considered in differential diagnosis. Rare non-neoplastic thyroid diseases will be discussed. Congenital hypothyroidism's frequency is relatively high and its early treatment is of vital importance for neonatal psychomotor development; CH is caused primarily by thyroid dysgenesis (85%) or dyshormonogenesis (10-15%), although secondary defects - hypothalamic and pituitary - can also be found; up to 40% of cases diagnosed on neonatal screening are transient. Inherited abnormalities of thyroid hormone binding proteins (TBG, TBP and albumin) include alterations in their concentration or affinity for iodothyronines, this leads to laboratory test abnormalities, although usually with normal free hormones and clinical euthyroidism. Thyroid hormone resistance is most commonly found in THRB gene mutations and more rarely in THRA mutations; in some cases both genes are unchanged (non-TR RTH). Recently the term 'reduced sensitivity to thyroid hormones' was introduced, which encompass not only iodothyronine receptor defects but also their defective transmembrane transport or metabolism. Rare causes of hyperthyroidism are: activating mutations in TSHR or GNAS genes, pituitary adenomas, differentiated thyroid cancer or gestational trophoblastic disease; congenital hyperthyroidism cases are also seen, although less frequently than CH. Like other organs and tissues, the thyroid can be affected by different inflammatory and infectious processes, including tuberculosis and sarcoidosis. In most of the rare thyroid diseases genetic factors play a key role, many of them can be classified as monogenic disorders. Although there are still some limitations, progress has been made in our understanding of

  3. Floral double mesiodentes: A rare case report

    PubMed Central

    Singaraju, Gowri Sankar; Reddy, B. Rama Mohan; Supraja, G.; Reddy, K. Narayana

    2015-01-01

    Mesiodens is the most commonly erupting supernumerary in the midline between two maxillary central incisors. Mesiodentes is a rare condition when mesiodens erupt in multiples, which may present as either labial or palatal to permanent central incisors. We report a rare case of double mesiodentes (non-syndromic mesiodentes) with floret like appearance. The presence of mesiodens has functional and esthetic implications. Careful radiographic evaluation should be done to prevent complications during their extraction. PMID:25810670

  4. Floral double mesiodentes: A rare case report.

    PubMed

    Singaraju, Gowri Sankar; Reddy, B Rama Mohan; Supraja, G; Reddy, K Narayana

    2015-01-01

    Mesiodens is the most commonly erupting supernumerary in the midline between two maxillary central incisors. Mesiodentes is a rare condition when mesiodens erupt in multiples, which may present as either labial or palatal to permanent central incisors. We report a rare case of double mesiodentes (non-syndromic mesiodentes) with floret like appearance. The presence of mesiodens has functional and esthetic implications. Careful radiographic evaluation should be done to prevent complications during their extraction.

  5. A rare complication of tracheal intubation

    PubMed Central

    Shukeri, Wan Fadzlina Wan Muhd; Hassan, Wan Mohd Nazaruddin Wan; Nadarajan, Chandran

    2016-01-01

    Accidental endobronchial intubation is a frequent complication in critically ill patients requiring tracheal intubation (TI). If such complication occurs, it is more often the right main bronchus that is intubated due to anatomical reasons. Left main bronchus (LMB) intubation is rare. Here, we report a case with auscultatory, bronchoscopic, and radiographic evidence of accidental LMB intubation in a pregnant woman with dengue shock syndrome. We highlight this case to increase awareness about this possible-but-rare complication of TI. PMID:27275080

  6. Rare Z decays and neutrino flavor universality

    NASA Astrophysics Data System (ADS)

    Durieux, Gauthier; Grossman, Yuval; König, Matthias; Kuflik, Eric; Ray, Shamayita

    2016-05-01

    We study rare four-body decays of the Z -boson involving at least one neutrino and one charged lepton. Large destructive interferences make these decays very sensitive to the Z couplings to neutrinos. As the identified charged leptons can determine the neutrino flavors, these decays probe the universality of the Z couplings to neutrinos. The rare four-body processes could be accurately measured at future lepton colliders, leading to percent level precision.

  7. Fatal attraction: rare species in the spotlight

    PubMed Central

    Angulo, Elena; Deves, Anne-Laure; Saint Jalmes, Michel; Courchamp, Franck

    2009-01-01

    The exploitation of rare and endangered species can end in the species's extinction because the increased value people associate with rarity increases the economic incentive to exploit the last individuals, creating a positive feedback loop. This recently proposed concept, called the anthropogenic Allee effect (AAE), relies on the assumption that people do value rarity, but this remains to be established. Moreover, it also remains to be determined whether attraction to rarity is a trait confined to a minority of hobbyists (e.g. wildlife collectors, exotic pet owners) or characteristic of the general public. We estimated how much the general public valued rare species compared with common ones, using five different metrics related to personal investment: time spent, physical effort, unpleasantness, economic investment and risk. We surveyed the visitors of a zoo. To see the rare species, the visitors to the zoo invested more time in searching and contemplation, they were ready to expend more physical effort, they tolerated more unpleasant conditions, they were willing to pay more and, finally, they risked more to obtain (steal) a rare species. Our results provide substantial evidence of how the general public places more value on rare species, compared with common species. This confirms the AAE as an actual process, which in addition concerns a large part of the population. This has important consequences for the conservation of species that are rare now, or that could become so in the future. PMID:19141425

  8. California Rare Endemics and Climate Change

    NASA Astrophysics Data System (ADS)

    Espinoza, M.

    2010-12-01

    California is known for its wide variety of endemic flora, from its annuals such as the Eschscholzia californica (California poppy) to the perennials like the Arctostaphylos pallida (Alameda manzanita), which happens to be a rare species. Each species plays an important role in the biodiversity of California, yet there are species that are threatened, not only by human interaction and urbanization, but by climate change. Species that we seldom see are now on the verge of becoming eradicated; rare endemics similar to Arctostaphylos pallida are now facing a new challenge that may severely impair their survival. The climate has changed significantly over the twentieth century and it has affected the distribution of rare endemics in California, both geographically as well as within their climatic and edaphic niches. Lilaeopsis masonii is just one rare endemic, however it serves as a representative of the other 23 species that were studied. Using Maxent, a climate-modeling program, it was viable to construct two climate envelopes of the masonii species: the early century envelope (1930-1959) and the later century envelope (1990-2009). When these two climate envelopes were compared, it became clear that the later century climate envelope had contracted radically, reshaping the climate niche of all rare endemics in California due to an increase in temperature. It is possible to conclude that the future of rare endemics hangs in the balance, where one degree higher in temperature is enough to topple the scale.

  9. Rare cell isolation and analysis in microfluidics

    PubMed Central

    Chen, Yuchao; Li, Peng; Huang, Po-Hsun; Xie, Yuliang; Mai, John D.; Wang, Lin; Nguyen, Nam-Trung; Huang, Tony Jun

    2014-01-01

    Rare cells are low-abundance cells in a much larger population of background cells. Conventional benchtop techniques have limited capabilities to isolate and analyze rare cells because of their generally low selectivity and significant sample loss. Recent rapid advances in microfluidics have been providing robust solutions to the challenges in the isolation and analysis of rare cells. In addition to the apparent performance enhancements resulting in higher efficiencies and sensitivity levels, microfluidics provides other advanced features such as simpler handling of small sample volumes and multiplexing capabilities for high-throughput processing. All of these advantages make microfluidics an excellent platform to deal with the transport, isolation, and analysis of rare cells. Various cellular biomarkers, including physical properties, dielectric properties, as well as immunoaffinities, have been explored for isolating rare cells. In this Focus article, we discuss the design considerations of representative microfluidic devices for rare cell isolation and analysis. Examples from recently published works are discussed to highlight the advantages and limitations of the different techniques. Various applications of these techniques are then introduced. Finally, a perspective on the development trends and promising research directions in this field are proposed. PMID:24406985

  10. Limitation of distribution of two rare ferns in fragmented landscape

    NASA Astrophysics Data System (ADS)

    Tájek, Přemysl; Bucharová, Anna; Münzbergová, Zuzana

    2011-09-01

    Species distribution in the landscape is limited either by 1. diaspore production, dispersal and establishment abilities or 2. by availability of suitable habitats; 3. or by a combination of both factors. The relative importance of these factors is species-dependent and has mainly been studied for seed plants. We studied the importance of habitat and dispersal limitation for distribution of two rare fern species, Asplenium adulterinum and Asplenium cuneifolium, restricted to serpentine rocks, using analysis of their distribution on a regional scale (several kilometers). Within the model region, all 98 serpentine rocks were mapped. We used data on abiotic characteristics and on the presence of all vascular plant species on the rocks to predict which of the rocks were suitable for the two Asplenium species. Suitable habitats were positively defined mainly by the presence of appropriate microhabitats and the height of the highest rock, which represents the size of space with lowered concurrence. Other determinants of habitat suitability differed between species. Neither species occupied all suitable localities, indicating dispersal limitation. Locality isolation significantly affected one of the species but not the other. Overall, the results suggest that both fern species have suitable but unoccupied localities in the region and demonstrates that ferns, similar to seed plants, are limited by their dispersal ability in the landscape.

  11. [Plant hormones, plant growth regulators].

    PubMed

    Végvári, György; Vidéki, Edina

    2014-06-29

    Plants seem to be rather defenceless, they are unable to do motion, have no nervous system or immune system unlike animals. Besides this, plants do have hormones, though these substances are produced not in glands. In view of their complexity they lagged behind animals, however, plant organisms show large scale integration in their structure and function. In higher plants, such as in animals, the intercellular communication is fulfilled through chemical messengers. These specific compounds in plants are called phytohormones, or in a wide sense, bioregulators. Even a small quantity of these endogenous organic compounds are able to regulate the operation, growth and development of higher plants, and keep the connection between cells, tissues and synergy between organs. Since they do not have nervous and immume systems, phytohormones play essential role in plants' life.

  12. Electronic plants

    PubMed Central

    Stavrinidou, Eleni; Gabrielsson, Roger; Gomez, Eliot; Crispin, Xavier; Nilsson, Ove; Simon, Daniel T.; Berggren, Magnus

    2015-01-01

    The roots, stems, leaves, and vascular circuitry of higher plants are responsible for conveying the chemical signals that regulate growth and functions. From a certain perspective, these features are analogous to the contacts, interconnections, devices, and wires of discrete and integrated electronic circuits. Although many attempts have been made to augment plant function with electroactive materials, plants’ “circuitry” has never been directly merged with electronics. We report analog and digital organic electronic circuits and devices manufactured in living plants. The four key components of a circuit have been achieved using the xylem, leaves, veins, and signals of the plant as the template and integral part of the circuit elements and functions. With integrated and distributed electronics in plants, one can envisage a range of applications including precision recording and regulation of physiology, energy harvesting from photosynthesis, and alternatives to genetic modification for plant optimization. PMID:26702448

  13. Biogeochemistry of the rare-earth elements with particular reference to hickory trees

    USGS Publications Warehouse

    Robinson, W.O.; Bastron, H.; Murata, K.J.

    1958-01-01

    Hickory trees concentrate the rare-earth elements in their leaves to a phenomenal degree and may contain as much as 2300 p.p.m. of total rare earths based on the dry weight of the leaves. The average proportions of the individual elements (atomic percent of the total rare-earth elements) in the leaves are: Y 36, La 16, Ce 14, Pr 2, Nd 20, Sm 1, Eu 0.7, Gd 3, Tb 0.6, Dy 3, Ho 0.7, Er 2, Tm 0.2, Yb 1, and Lu 0.2. The similarity in the proportions of the rare-earth elements in the leaves and in the exchange complex of the soil on which the hickory trees grow indicates that the trees do not fractionate the rare earths appreciably. The variation of the rare-earth elements in the leaves and soils can be explained generally in terms of the relative abundance of the cerium group and the yttrium group, except for the element cerium. The large fluctuations in the proportion of cerium [Ce/(La + Nd) atomic ratios of 0.16 to 0.86] correlate with oxidation-reduction conditions in the soil profile. The substitution of dilute H2SO3 for dilute HC1 in the determination of available rare-earth elements brings about a large increase in the proportion of cerium that is extracted from an oxygenated subsoil. These relationships strongly suggest that quadrivalent cerium is present in oxygenated subsoil and is less available to plants than the other rare-earth elements that do not undergo such a change in valence. A few parts per billion of rare-earth elements have been detected in two samples of ground water. ?? 1958.

  14. Plant Factory

    NASA Astrophysics Data System (ADS)

    Ikeda, Hideo

    Recently, much attention is paid on the plant factory, as it enable to grow plants stably under extraordinary climate condition such as high and/or low air temperature and less rain. Lots of questions such as decreasing investing cost, realizing stable plant production and developing new growing technique should be solved for making popular this growing system. However, I think that we can introduce a highly developed Japanese industrial now-how to plant factory system and can produce a business chance to the world market.

  15. Plant Minders

    NASA Technical Reports Server (NTRS)

    1988-01-01

    Indoor plants are automatically watered by the Aqua Trends watering system. System draws water from building outlets or from pump/reservoir module and distributes it to the plants via a network of tubes and adjustable nozzles. Key element of system is electronic controller programmed to dispense water according to the needs of various plants in an installation. Adjustable nozzle meters out exactly right amount of water at proper time to the plant it's serving. More than 100 Aqua/Trends systems are in service in the USA, from a simple residential system to a large Mirage III system integrated to water all greenery in a large office or apartment building.

  16. A virus-induced gene silencing (VIGS) system for functional genomics in the parasitic plant Striga hermonthica

    PubMed Central

    2014-01-01

    Background Striga hermonthica is a hemiparasitic weed that infects cereals in Sub Sahara Africa (SSA) resulting in up to 100% grain yield loss. This significant loss in grain yields is a major contributor to food insecurity and poverty in the region. Current strategies to control the parasite are costly, unavailable and remain unpracticed by small-scale farmers, underscoring the need for more economical and sustainable control strategies. Development of resistant germplasm is the most sustainable strategy in the control of S. hermonthica, but is constrained by paucity of resistance genes for introduction into crop germplasm. RNA interference (RNAi) has potential for developing host-derived resistance against S. hermonthica by transformation of host crops with RNAi sequences targeted at critical Striga genes. The application of RNAi in management of S. hermonthica is however constrained by lack of efficient high throughput screening protocols for the candidate genes for silencing, as well as sub optimal delivery of siRNAs into the parasite. In comparison to stable transformation, viral induced gene silencing (VIGS) is a rapid and powerful tool for plant functional genomics and provides an easy and effective strategy in screening for putative candidate genes to target through RNAi. In addition, VIGS allows for a secondary amplification of the RNAi signal increasing the siRNA threshold and facilitates siRNA transport through viral movement proteins. We tested the efficiency of the Tobacco rattle virus (TRV1 and TRV2) VIGS vectors in silencing S. hermonthica phytoene desaturase (PDS) gene through agrodrench and agro-infiltration. Results We report the validation of VIGS in S. hermonthica using a silencing cassette generated from TRV with a PDS gene insert. Agro-infiltrated and agro-drenched S. hermonthica leaves showed photo-bleaching phenotypes typical for PDS silencing within 7 and 14 days post infection respectively. In both cases S. hermonthica plants recovered

  17. Refined potentials for rare gas atom adsorption on rare gas and alkali-halide surfaces

    NASA Technical Reports Server (NTRS)

    Wilson, J. W.; Heinbockel, J. H.; Outlaw, R. A.

    1985-01-01

    The utilization of models of interatomic potential for physical interaction to estimate the long range attractive potential for rare gases and ions is discussed. The long range attractive force is calculated in terms of the atomic dispersion properties. A data base of atomic dispersion parameters for rare gas atoms, alkali ion, and halogen ions is applied to the study of the repulsive core; the procedure for evaluating the repulsive core of ion interactions is described. The interaction of rare gas atoms on ideal rare gas solid and alkali-halide surfaces is analyzed; zero coverage absorption potentials are derived.

  18. [Effects of arbuscular mycorrhizal fungi on the growth and rare earth elements uptake of soybean grown in rare earth mine tailings].

    PubMed

    Guo, Wei; Zhao, Ren-xin; Zhao, Wen-jing; Fu, Rui-ying; Guo, Jiang-yuan; Zhang, Jun

    2013-05-01

    A greenhouse pot experiment was conducted to investigate the influence of arbuscular mycorrhizal (AM) fungi Glomus versiforme on the plant growth, nutrient uptake, C: N: P stoichiometric, uptake of heavy metals and rare earth elements by soybean (Glycine max) grown in rare earth mine tailings. The aim was to provide a basis for the revegetation of rare earth mine tailings. The results indicated that soybean had a high mycorrhizal colonization and symbiotic associations were successfully established with G. versiforme, with an average rate of approximately 67%. The colonization of G. versiforme significantly promoted the growth of soybean, increased P, K contents, and decreased C: N: P ratios, supporting the growth rate hypothesis. Inoculation with G. versiforme significantly decreased shoots and roots La, Ce, Pr and Nd concentrations of soybean compared to the control treatment. However, inoculation with G. versiforme had no significant effect on the heavy metal concentrations, except for significantly decreased shoot Fe and Cr concentrations and increased root Cd concentrations. The experiment demonstrates that AM fungi have a potential role for soybean to adapt the composite adversity of rare earth tailings and play a positive role in revegetation of rare earth mine tailings. Further studies on the role of AM fungi under natural conditions should be conducted.

  19. Separation of rare gases and chiral molecules by selective binding in porous organic cages

    SciTech Connect

    Chen, Linjiang; Reiss, Paul S.; Chong, Samantha Y.; Holden, Daniel; Jelfs, Kim E.; Hasell, Tom; Little, Marc A.; Kewley, Adam; Briggs, Michael E.; Stephenson, Andrew; Thomas, K. M.; Armstrong, Jayne A.; Bell, Jon; Busto, Jose; Noel, Raymond; Liu, Jian; Strachan, Denis M.; Thallapally, Praveen K.; Cooper, Andrew I.

    2014-10-31

    Abstract: The rare gases krypton, xenon, and radon pose both an economic opportunity and a potential environmental hazard. Xenon is used in commercial lighting, medical imaging, and anesthesia, and can sell for $5,000 per kilogram. Radon, by contrast, Is naturally radioactive and the second largest cause of lung cancer, and radioactive xenon, 133Xe, was a major pollutant released In the Fukushima Daiichi Nuclear Power Plant disaster. We describe an organic cage molecule that can capture xenon and radon with unprecedented selectivity, suggesting new technologies for environmental monitoring, removal of pollutants, or the recovery of rare, valuable elements from air.

  20. Rare earth elements and permanent magnets (invited)

    NASA Astrophysics Data System (ADS)

    Dent, Peter C.

    2012-04-01

    Rare earth (RE) magnets have become virtually indispensible in a wide variety of industries such as aerospace, automotive, electronics, medical, and military. RE elements are essential ingredients in these high performance magnets based on intermetallic compounds RECo5, RE2TM17 (TM: transition metal), and RE2TM14B. Rare earth magnets are known for their superior magnetic properties—high induction, and coercive force. These properties arise due to the extremely high magnetocrystalline anisotropy made possible by unique 3d-4f interactions between transition metals and rare earths. For more than 40 years, these magnets remain the number one choice in applications that require high magnetic fields in extreme operating conditions—high demagnetization forces and high temperature. EEC produces and specializes in RECo5 and RE2TM17 type sintered magnets. Samarium and gadolinium are key RE ingredients in the powder metallurgical magnet production processes which include melting, crushing, jet milling, pressing, sintering, and heat treating. The magnetic properties and applications of these magnets will be discussed. We will also briefly discuss the past, current, and future of the permanent magnet business. Currently, over 95% of all pure rare earth oxides are sourced from China, which currently controls the market. We will provide insights regarding current and potential new magnet technologies and designer choices, which may mitigate rare earth supply chain issues now and into the future.

  1. Locally rare species influence grassland ecosystem multifunctionality.

    PubMed

    Soliveres, Santiago; Manning, Peter; Prati, Daniel; Gossner, Martin M; Alt, Fabian; Arndt, Hartmut; Baumgartner, Vanessa; Binkenstein, Julia; Birkhofer, Klaus; Blaser, Stefan; Blüthgen, Nico; Boch, Steffen; Böhm, Stefan; Börschig, Carmen; Buscot, Francois; Diekötter, Tim; Heinze, Johannes; Hölzel, Norbert; Jung, Kirsten; Klaus, Valentin H; Klein, Alexandra-Maria; Kleinebecker, Till; Klemmer, Sandra; Krauss, Jochen; Lange, Markus; Morris, E Kathryn; Müller, Jörg; Oelmann, Yvonne; Overmann, Jörg; Pašalić, Esther; Renner, Swen C; Rillig, Matthias C; Schaefer, H Martin; Schloter, Michael; Schmitt, Barbara; Schöning, Ingo; Schrumpf, Marion; Sikorski, Johannes; Socher, Stephanie A; Solly, Emily F; Sonnemann, Ilja; Sorkau, Elisabeth; Steckel, Juliane; Steffan-Dewenter, Ingolf; Stempfhuber, Barbara; Tschapka, Marco; Türke, Manfred; Venter, Paul; Weiner, Christiane N; Weisser, Wolfgang W; Werner, Michael; Westphal, Catrin; Wilcke, Wolfgang; Wolters, Volkmar; Wubet, Tesfaye; Wurst, Susanne; Fischer, Markus; Allan, Eric

    2016-05-19

    Species diversity promotes the delivery of multiple ecosystem functions (multifunctionality). However, the relative functional importance of rare and common species in driving the biodiversity-multifunctionality relationship remains unknown. We studied the relationship between the diversity of rare and common species (according to their local abundances and across nine different trophic groups), and multifunctionality indices derived from 14 ecosystem functions on 150 grasslands across a land-use intensity (LUI) gradient. The diversity of above- and below-ground rare species had opposite effects, with rare above-ground species being associated with high levels of multifunctionality, probably because their effects on different functions did not trade off against each other. Conversely, common species were only related to average, not high, levels of multifunctionality, and their functional effects declined with LUI. Apart from the community-level effects of diversity, we found significant positive associations between the abundance of individual species and multifunctionality in 6% of the species tested. Species-specific functional effects were best predicted by their response to LUI: species that declined in abundance with land use intensification were those associated with higher levels of multifunctionality. Our results highlight the importance of rare species for ecosystem multifunctionality and help guiding future conservation priorities.

  2. Rare earth element scavenging in seawater

    NASA Astrophysics Data System (ADS)

    Byrne, Robert H.; Kim, Ki-Hyun

    1990-10-01

    Examinations of rare earth element (REE) adsorption in seawater, using a variety of surface-types, indicated that, for most surfaces, light rare earth elements (LREEs) are preferentially adsorbed compared to the heavy rare earths (HREEs). Exceptions to this behavior were observed only for silica phases (glass surfaces, acid-cleaned diatomaceous earth, and synthetic SiO 2). The affinity of the rare earths for surfaces can be strongly affected by thin organic coatings. Glass surfaces which acquired an organic coating through immersion in Tampa Bay exhibited adsorptive behavior typical of organic-rich, rather than glass, surfaces. Models of rare earth distributions between seawater and carboxylate-rich surfaces indicate that scavenging processes which involve such surfaces should exhibit a strong dependence on pH and carbonate complexation. Scavenging models involving carboxylate surfaces produce relative REE abundance patterns in good general agreement with observed shale-normalized REE abundances in seawater. Scavenging by carboxylate-rich surfaces should produce HREE enrichments in seawater relative to the LREEs and may produce enrichments of lanthanum relative to its immediate trivalent neighbors. Due to the origin of distribution coefficients as a difference between REE solution complexation (which increases strongly with atomic number) and surface complexation (which apparently also increases with atomic number) the relative solution abundance patterns of the REEs produced by scavenging reactions can be quite complex.

  3. Locally rare species influence grassland ecosystem multifunctionality

    PubMed Central

    Manning, Peter; Prati, Daniel; Gossner, Martin M.; Alt, Fabian; Arndt, Hartmut; Baumgartner, Vanessa; Binkenstein, Julia; Birkhofer, Klaus; Blaser, Stefan; Blüthgen, Nico; Boch, Steffen; Böhm, Stefan; Börschig, Carmen; Buscot, Francois; Diekötter, Tim; Heinze, Johannes; Hölzel, Norbert; Jung, Kirsten; Klaus, Valentin H.; Klein, Alexandra-Maria; Kleinebecker, Till; Klemmer, Sandra; Krauss, Jochen; Lange, Markus; Morris, E. Kathryn; Müller, Jörg; Oelmann, Yvonne; Overmann, Jörg; Pašalić, Esther; Renner, Swen C.; Rillig, Matthias C.; Schaefer, H. Martin; Schloter, Michael; Schmitt, Barbara; Schöning, Ingo; Schrumpf, Marion; Sikorski, Johannes; Socher, Stephanie A.; Solly, Emily F.; Sonnemann, Ilja; Sorkau, Elisabeth; Steckel, Juliane; Steffan-Dewenter, Ingolf; Stempfhuber, Barbara; Tschapka, Marco; Türke, Manfred; Venter, Paul; Weiner, Christiane N.; Weisser, Wolfgang W.; Werner, Michael; Westphal, Catrin; Wilcke, Wolfgang; Wolters, Volkmar; Wubet, Tesfaye; Wurst, Susanne; Fischer, Markus; Allan, Eric

    2016-01-01

    Species diversity promotes the delivery of multiple ecosystem functions (multifunctionality). However, the relative functional importance of rare and common species in driving the biodiversity–multifunctionality relationship remains unknown. We studied the relationship between the diversity of rare and common species (according to their local abundances and across nine different trophic groups), and multifunctionality indices derived from 14 ecosystem functions on 150 grasslands across a land-use intensity (LUI) gradient. The diversity of above- and below-ground rare species had opposite effects, with rare above-ground species being associated with high levels of multifunctionality, probably because their effects on different functions did not trade off against each other. Conversely, common species were only related to average, not high, levels of multifunctionality, and their functional effects declined with LUI. Apart from the community-level effects of diversity, we found significant positive associations between the abundance of individual species and multifunctionality in 6% of the species tested. Species-specific functional effects were best predicted by their response to LUI: species that declined in abundance with land use intensification were those associated with higher levels of multifunctionality. Our results highlight the importance of rare species for ecosystem multifunctionality and help guiding future conservation priorities. PMID:27114572

  4. Urban plants as genetic reservoirs or threats to the integrity of bushland plant populations.

    PubMed

    Roberts, David G; Ayre, David J; Whelan, Robert J

    2007-06-01

    Remnant plants in urban fringes and native plants in gardens have the potential to contribute to the conservation of threatened plants by increasing genetic diversity, effective size of populations, and levels of genetic connectedness. But they also pose a threat through the disruption of locally adapted gene pools. At Hyams Beach, New South Wales, Australia, four bushland stands of the rare shrub, Grevillea macleayana McGillivray, surround an urban area containing remnant and cultivated specimens of this species. Numbers of inflorescences per plant, fruits per plant, and visits by pollinators were similar for plants in urban gardens and bushland. Urban plants represented a substantial but complex genetic resource, displaying more genetic diversity than bushland plants judged byH(e), numbers of alleles per locus, and number of private alleles. Of 27 private alleles in urban plants, 17 occurred in a set of 19 exotic plants. Excluding the exotic plants, all five stands displayed a moderate differentiation (F(ST)= 0.14 +/- 0.02), although the urban remnants clustered with two of the bushland stands. These patterns may be explained by high levels of selfing and inbreeding in this species and by long-distance dispersal (several seeds in the urban stand were fathered by plants in other stands). Genetic leakage (gene flow) from exotic plants to 321 seeds on surrounding remnant or bushland plants has not occurred. Our results demonstrate the conservation value of this group of urban plants, which are viable, productive, genetically diverse, and interconnected with bushland plants. Gene flow has apparently not yet led to genetic contamination of bushland populations, but high levels of inbreeding would make this a rare event and difficult to detect.

  5. Plant Behavior

    ERIC Educational Resources Information Center

    Liu, Dennis W. C.

    2014-01-01

    Plants are a huge and diverse group of organisms, ranging from microscopic marine phytoplankton to enormous terrestrial trees epitomized by the giant sequoia: 300 feet tall, living 3000 years, and weighing as much as 3000 tons. For this plant issue of "CBE-Life Sciences Education," the author focuses on a botanical topic that most…

  6. Plant Immunity

    USDA-ARS?s Scientific Manuscript database

    Plants are faced with defending themselves against a multitude of pathogens, including bacteria, fungi, viruses, nematodes, etc. Immunity is multi-layered and complex. Plants can induce defenses when they recognize small peptides, proteins or double-stranded RNA associated with pathogens. Recognitio...

  7. Plant Identification.

    ERIC Educational Resources Information Center

    National Audubon Society, New York, NY.

    This set of teaching aids consists of 12 Audubon Nature Bulletins, providing teachers and students with informational reading on plants. The bulletins include these titles: The Parade of Spring Wild Flowers, Wild Flowers of Our Prairies, Seeds and How They Travel, Poison Ivy and Other Poisonous Plants, The Forest Community, Common Trees and Their…

  8. Plant Behavior

    ERIC Educational Resources Information Center

    Liu, Dennis W. C.

    2014-01-01

    Plants are a huge and diverse group of organisms, ranging from microscopic marine phytoplankton to enormous terrestrial trees epitomized by the giant sequoia: 300 feet tall, living 3000 years, and weighing as much as 3000 tons. For this plant issue of "CBE-Life Sciences Education," the author focuses on a botanical topic that most…

  9. Carnivorous Plants.

    ERIC Educational Resources Information Center

    Canipe, Stephen

    This biology lesson on carnivorous (insectivorous) plants is designed to supplement the textbook in the areas of plant diversity, ecology, and distribution. An introduction provides general background information for use as lecture material by the teacher or as reading and/or study material for students. The introduction also includes…

  10. Carnivorous Plants.

    ERIC Educational Resources Information Center

    Canipe, Stephen

    This biology lesson on carnivorous (insectivorous) plants is designed to supplement the textbook in the areas of plant diversity, ecology, and distribution. An introduction provides general background information for use as lecture material by the teacher or as reading and/or study material for students. The introduction also includes…

  11. Plant Identification.

    ERIC Educational Resources Information Center

    National Audubon Society, New York, NY.

    This set of teaching aids consists of 12 Audubon Nature Bulletins, providing teachers and students with informational reading on plants. The bulletins include these titles: The Parade of Spring Wild Flowers, Wild Flowers of Our Prairies, Seeds and How They Travel, Poison Ivy and Other Poisonous Plants, The Forest Community, Common Trees and Their…

  12. Indigenous actinorhizal plants of Australia.

    PubMed

    Ganguli, Nishath K; Kennedy, Ivan R

    2013-11-01

    Indigenous species of actinorhizal plants of Casuarinaceae, Elaeagnaceae and Rhamnaceae are found in specific regions of Australia. Most of these plants belong to Casuarinaceae, the dominant actinorhizal family in Australia. Many of them have significant environmental and economical value. The other two families with their indigenous actinorhizal plants have only a minor presence in Australia. Most Australian actinorhizal plants have their native range only in Australia, whereas two of these plants are also found indigenously elsewhere. The nitrogen-fixing ability of these plants varies between species. This ability needs to be investigated in some of these plants. Casuarinas form a distinctive but declining part of the Australian landscape. Their potential has rarely been applied in forestry in Australia despite their well-known uses, which are being judiciously exploited elsewhere. To remedy this oversight, a programme has been proposed for increasing and improving casuarinas that would aid in greening more regions of Australia, increasing the soil fertility and the area of wild life habitat (including endangered species). Whether these improved clones would be productive with local strains of Frankia or they need an external inoculum of Frankia should be determined and the influence of mycorrhizal fungi on these clones also should be investigated.

  13. Mineral resource of the month: rare earth elements

    USGS Publications Warehouse

    ,

    2011-01-01

    The article provides information on rare earth elements, which are group of 17 natural metallic elements. The rare earth elements are scandium, yttrium and lanthanides and classified into light rare earth elements (LREE) and heavy rate earth elements (HREE). The principal ores of the rare earth elements are identified. An overview of China's production of 97 percent of the rare earths in the world is provided. Commercial applications of rare earths are described.

  14. Recovering heavy rare earth metals from magnet scrap

    DOEpatents

    Ott, Ryan T.; McCallum, Ralph W.; Jones, Lawrence L.

    2017-08-08

    A method of treating rare earth metal-bearing permanent magnet scrap, waste or other material in a manner to recover the heavy rare earth metal content separately from the light rare earth metal content. The heavy rare earth metal content can be recovered either as a heavy rare earth metal-enriched iron based alloy or as a heavy rare earth metal based alloy.

  15. Coal fly ash as a resource for rare earth elements.

    PubMed

    Franus, Wojciech; Wiatros-Motyka, Małgorzata M; Wdowin, Magdalena

    2015-06-01

    Rare earth elements (REE) have been recognised as critical raw materials, crucial for many clean technologies. As the gap between their global demand and supply increases, the search for their alternative resources becomes more and more important, especially for the countries which depend highly on their import. Coal fly ash (CFA), which when not utilised is considered waste, has been regarded as the possible source of many elements, including REE. Due to the increase in the energy demand, CFA production is expected to grow, making research into the use of this material a necessity. As Poland is the second biggest coal consumer in the European Union, the authors have studied different coal fly ashes from ten Polish power plants for their rare earth element content. All the fly ashes have a broadly similar distribution of rear earth elements, with light REE being dominant. Most of the samples have REE content relatively high and according to Seredin and Dai (Int J Coal Geol 94: 67-93, 2012) classification can be considered promising REE raw materials.

  16. Black-spot poison ivy: a rare phenomenon.

    PubMed

    Paniagua, Carmen T; Bean, Ashley S

    2011-06-01

    To provide an overview of the clinical presentation, diagnosis, management, and treatment with advanced practice nursing implications of black-spot poison ivy phenomenon. Case presentation and comprehensive literature review on black-spot poison ivy. Black-spot poison ivy is a rare phenomenon and usually poses a diagnostic challenge. It usually presents after exposure to a higher concentration of uroshiol on Toxicodendron plants. Patients present with black-spot deposits on the epidermis with underlying poison ivy dermatitis. The black deposits cannot be washed off the skin and are followed by itchy blisters. They eventually peel off and the skin heals without scarring. An understanding of the pathophysiology, clinical presentation, treatment, and management of this rare phenomenon is important for the nurse practitioner (NP) to be able to make an accurate diagnosis and initiate appropriate treatment without delay. The NP's recognition and differentiation of it from other skin disorders including melanoma is paramount. ©2011 The Author(s) Journal compilation ©2011 American Academy of Nurse Practitioners.

  17. Plant conservation in temple yards of orissa.

    PubMed

    Mohanty, R B; Mohapatra, B K; Padhy, S N

    1997-10-01

    This paper is a brief survey of the role of temples and holy places in nurturing the surrounding flora and its habitat. Eightysix kinds of plants in temple yards and gardens of orissa have been enlisted where they are cultivated and preserved for different temple rituals. These plants are seen rarely in wild but are saved from extinction by their association with temple rituals and ceremonies.

  18. PLANT CONSERVATION IN TEMPLE YARDS OF ORISSA

    PubMed Central

    Mohanty, R.B; Mohapatra, B.K; Padhy, S.N

    1997-01-01

    This paper is a brief survey of the role of temples and holy places in nurturing the surrounding flora and its habitat. Eightysix kinds of plants in temple yards and gardens of orissa have been enlisted where they are cultivated and preserved for different temple rituals. These plants are seen rarely in wild but are saved from extinction by their association with temple rituals and ceremonies. PMID:22556826

  19. Plant minichromosomes.

    PubMed

    Birchler, James A; Graham, Nathaniel D; Swyers, Nathan C; Cody, Jon P; McCaw, Morgan E

    2016-02-01

    Plant minichromosomes have the potential for stacking multiple traits on a separate entity from the remainder of the genome. Transgenes carried on an independent chromosome would facilitate conferring many new properties to plants and using minichromosomes as genetic tools. The favored method for producing plant minichromosomes is telomere-mediated chromosomal truncation because the epigenetic nature of centromere function prevents using centromere sequences to confer the ability to organize a kinetochore when reintroduced into plant cells. Because haploid induction procedures are not always complete in eliminating one parental genome, chromosomes from the inducer lines are often present in plants that are otherwise haploid. This fact suggests that minichromosomes could be combined with doubled haploid breeding to transfer stacked traits more easily to multiple lines and to use minichromosomes for massive scale genome editing.

  20. Nuclear Astrophysics with rare isotopes at FRIB

    NASA Astrophysics Data System (ADS)

    Schatz, Hendrik

    2011-05-01

    The Facility for Rare Isotope Beams (FRIB) currently under construction at Michigan State University will be one of the worlds’ most powerful accelerators to produce rare isotopes. These isotopes live only fractions of seconds, but their properties are imprinted onto the composition of the visible universe and the nature of stellar explosions. FRIB will produce for the first time many of the rare isotopes that are part of the rapid neutron capture process, responsible for the origin of heavy elements; it will measure reaction rates that govern stellar explosions such as supernovae, novae, and X-ray bursts; and it will produce the same exotic nuclei that form the crust of neutron stars. I will discuss how data from FRIB, together with new observational data, promise to address many open questions at the intersection of nuclear physics and astronomy, including the chemical evolution of our Galaxy, the nuclear energy sources of stellar explosions, and the nature of neutron stars.

  1. Rare gases in cyclosilicates and cogenetic minerals

    NASA Technical Reports Server (NTRS)

    Saito, K.; Alexander, E. C., Jr.; Dragon, J. C.; Zashu, S.

    1984-01-01

    The cyclosilicate minerals, beryl, tourmaline, and cordierite, typically contain large amounts of He-4 and Ar-40 which are not in situ radiogenic products. In the study of excess rare gases in cyclosilicates, one of the most enigmatic observations is the age effect, a qualitative tendency for geologically older samples to contain more excess He-4 and Ar-40 than younger samples. The present investigation is concerned with measurements regarding the abundance and isotopic composition of all five rare gases in a number of cyclosilicates as well as in their cogenetic minerals. The significance of the obtained data is discussed. The data indicate that cyclosilicates sample the rare gases present in the environment in which they crystallize. This 'sampling' involves major elemental fractionations which are variable but mineral specific. Cyclosilicates can, therefore, be used to probe the isotopic ratios and elemental compositions.

  2. An Erupted Dilated Odontoma: A Rare Presentation

    PubMed Central

    Sharma, Gaurav; Nagra, Amritpreet; Singh, Gurkeerat; Nagpal, Archna; Soin, Atul; Bhardwaj, Vishal

    2016-01-01

    A dilated odontoma is an extremely rare developmental anomaly represented as a dilatation of the crown and root as a consequence of a deep, enamel-lined invagination and is considered a severe variant of dens invaginatus. An oval shape of the tooth lacking morphological characteristics of a crown or root implies that the invagination happened in the initial stages of morphodifferentiation. Spontaneous eruption of an odontoma is a rare occurrence and the occurrence of a dilated odontoma in a supernumerary tooth is even rarer with only a few case reports documented in the English literature. We present an extremely rare case of erupted dilated odontoma occurring in the supernumerary tooth in anterior maxillary region in an 18-year-old male, which, to the best of our knowledge, is the first ever case reported in English literature. PMID:26989523

  3. Rare earth phosphors and phosphor screens

    DOEpatents

    Buchanan, Robert A.; Maple, T. Grant; Sklensky, Alden F.

    1981-01-01

    This invention relates to rare earth phosphor screens for converting image carrying incident radiation to image carrying visible or near-visible radiation and to the rare earth phosphor materials utilized in such screens. The invention further relates to methods for converting image carrying charged particles to image carrying radiation principally in the blue and near-ultraviolet region of the spectrum and to stabilized rare earth phosphors characterized by having a continuous surface layer of the phosphors of the invention. More particularly, the phosphors of the invention are oxychlorides and oxybromides of yttrium, lanthanum and gadolinium activated with trivalent cerium and the conversion screens are of the type illustratively including x-ray conversion screens, image amplifier tube screens, neutron imaging screens, cathode ray tube screens, high energy gamma ray screens, scintillation detector screens and screens for real-time translation of image carrying high energy radiation to image carrying visible or near-visible radiation.

  4. Material efficiency: rare and critical metals.

    PubMed

    Ayres, Robert U; Peiró, Laura Talens

    2013-03-13

    In the last few decades, progress in electronics, especially, has resulted in important new uses for a number of geologically rare metals, some of which were mere curiosities in the past. Most of them are not mined for their own sake (gold, the platinum group metals and the rare Earth elements are exceptions) but are found mainly in the ores of the major industrial metals, such as aluminium, copper, zinc and nickel. We call these major metals 'attractors' and the rare accompanying metals 'hitch-hikers'. The key implication is that rising prices do not necessarily call forth greater output because that would normally require greater output of the attractor metal. We trace the geological relationships and the functional uses of these metals. Some of these metals appear to be irreplaceable in the sense that there are no known substitutes for them in their current functional uses. Recycling is going to be increasingly important, notwithstanding a number of barriers.

  5. Preparation and processing of rare earth chalcogenides

    NASA Astrophysics Data System (ADS)

    Gschneidner, K. A.

    1998-10-01

    Rare earth chalcogenides are initially prepared by a direct combination of the pure rare earth metal and the pure chalogen element with or without a catalyst. The use of iodine (10 to 100 mg) as a fluxing agent (catalyst), especially to prepare heavy lanthanide chalcogenides, greatly speeds up the formation of the rare earth chalcogenide. The resultant powders are consolidated by melting, pressure assisted sintering (PAS), or pressure assisted reaction sintering (PARS) to obtain near theoretical density solids. Mechanical alloying is a useful technique for preparing ternary alloys. In addition, mechanical alloying and mechanical milling can be used to form metastable allotropic forms of the yttrium and heavy lanthanide sulfides. Chemical analysis techniques are also described because it is strongly recommended that samples prepared by melting should have their chemical compositions verified because of chalogen losses in the melting step.

  6. Kinetic Global Modeling of Rare Gas Lasers

    NASA Astrophysics Data System (ADS)

    Parsey, Guy; Verboncoeur, John; Christlieb, Andrew

    2016-10-01

    Akin to diode-pumped alkali metal lasers, electronically excited states of rare gases (e.g. Ar and Kr) have been shown to operate as chemically inert three-level gain media for an optically pumped laser system. As opposed to vaporization heating, these systems rely on electric discharge to efficiently maintain a population of metastable states acting as the bottom laser level. We propose that a modified electron energy distribution (EEDF) in the electric heating can tune optically pumped rare gas laser (OPRGL) efficiencies. The EEDF factors into all plasma phase chemistry within the underlying reaction network, and is assumed to be maintained by discharge and electron sources. Using parameter scanning methods within the kinetic global modeling framework (KGMf), optimized EEDFs are found for metastable production and increasing OPRGL operational efficiencies. Finally, we investigate the feasibility of using a modified EEDF to drive a rare gas laser system without optical pumping. Supported by AFOSR and an MSU SPG.

  7. Rare Endobronchial metastasis from uterine leiomyosarcoma

    PubMed Central

    Ghosh, Saswata; Kundu, Susmita; Pal, Amitava; Paul, Suman

    2015-01-01

    Uterine sarcomas are rare and represent approximately 3.2% of all invasive uterine cancers. The annual incidence rate is less than two per 100,000 women. The median age at which uterine sarcoma diagnosed is 56 years. The most common histologic pattern is leiomyosarcoma (LMS) which originates from the myometrium or myometrial vessels. Uterine LMSs are aggressive tumors with high rates of recurrence. The most common mode of spread is hematogenous, with lymphatic spread being rare. Recurrences of up to 70% are reported in stage I and II disease with the site of recurrence being distal, most commonly the lungs or the upper abdomen. But the intra bronchial spread is extremely rare. Here we are reporting a case of uterine LMS with endobronchial metastasis causing whole lung collapse. PMID:25814801

  8. Collaboration for rare disease drug discovery research

    PubMed Central

    Litterman, Nadia K.; Rhee, Michele; Swinney, David C.; Ekins, Sean

    2014-01-01

    Rare disease research has reached a tipping point, with the confluence of scientific and technologic developments that if appropriately harnessed, could lead to key breakthroughs and treatments for this set of devastating disorders. Industry-wide trends have revealed that the traditional drug discovery research and development (R&D) model is no longer viable, and drug companies are evolving their approach. Rather than only pursue blockbuster therapeutics for heterogeneous, common diseases, drug companies have increasingly begun to shift their focus to rare diseases. In academia, advances in genetics analyses and disease mechanisms have allowed scientific understanding to mature, but the lack of funding and translational capability severely limits the rare disease research that leads to clinical trials. Simultaneously, there is a movement towards increased research collaboration, more data sharing, and heightened engagement and active involvement by patients, advocates, and foundations. The growth in networks and social networking tools presents an opportunity to help reach other patients but also find researchers and build collaborations. The growth of collaborative software that can enable researchers to share their data could also enable rare disease patients and foundations to manage their portfolio of funded projects for developing new therapeutics and suggest drug repurposing opportunities. Still there are many thousands of diseases without treatments and with only fragmented research efforts. We will describe some recent progress in several rare diseases used as examples and propose how collaborations could be facilitated. We propose that the development of a center of excellence that integrates and shares informatics resources for rare diseases sponsored by all of the stakeholders would help foster these initiatives. PMID:25685324

  9. Rare variant association test with multiple phenotypes.

    PubMed

    Lee, Selyeong; Won, Sungho; Kim, Young Jin; Kim, Yongkang; Kim, Bong-Jo; Park, Taesung

    2017-04-01

    Although genome-wide association studies (GWAS) have now discovered thousands of genetic variants associated with common traits, such variants cannot explain the large degree of "missing heritability," likely due to rare variants. The advent of next generation sequencing technology has allowed rare variant detection and association with common traits, often by investigating specific genomic regions for rare variant effects on a trait. Although multiple correlated phenotypes are often concurrently observed in GWAS, most studies analyze only single phenotypes, which may lessen statistical power. To increase power, multivariate analyses, which consider correlations between multiple phenotypes, can be used. However, few existing multivariant analyses can identify rare variants for assessing multiple phenotypes. Here, we propose Multivariate Association Analysis using Score Statistics (MAAUSS), to identify rare variants associated with multiple phenotypes, based on the widely used sequence kernel association test (SKAT) for a single phenotype. We applied MAAUSS to whole exome sequencing (WES) data from a Korean population of 1,058 subjects to discover genes associated with multiple traits of liver function. We then assessed validation of those genes by a replication study, using an independent dataset of 3,445 individuals. Notably, we detected the gene ZNF620 among five significant genes. We then performed a simulation study to compare MAAUSS's performance with existing methods. Overall, MAAUSS successfully conserved type 1 error rates and in many cases had a higher power than the existing methods. This study illustrates a feasible and straightforward approach for identifying rare variants correlated with multiple phenotypes, with likely relevance to missing heritability.

  10. Collaboration for rare disease drug discovery research.

    PubMed

    Litterman, Nadia K; Rhee, Michele; Swinney, David C; Ekins, Sean

    2014-01-01

    Rare disease research has reached a tipping point, with the confluence of scientific and technologic developments that if appropriately harnessed, could lead to key breakthroughs and treatments for this set of devastating disorders. Industry-wide trends have revealed that the traditional drug discovery research and development (R&D) model is no longer viable, and drug companies are evolving their approach. Rather than only pursue blockbuster therapeutics for heterogeneous, common diseases, drug companies have increasingly begun to shift their focus to rare diseases. In academia, advances in genetics analyses and disease mechanisms have allowed scientific understanding to mature, but the lack of funding and translational capability severely limits the rare disease research that leads to clinical trials. Simultaneously, there is a movement towards increased research collaboration, more data sharing, and heightened engagement and active involvement by patients, advocates, and foundations. The growth in networks and social networking tools presents an opportunity to help reach other patients but also find researchers and build collaborations. The growth of collaborative software that can enable researchers to share their data could also enable rare disease patients and foundations to manage their portfolio of funded projects for developing new therapeutics and suggest drug repurposing opportunities. Still there are many thousands of diseases without treatments and with only fragmented research efforts. We will describe some recent progress in several rare diseases used as examples and propose how collaborations could be facilitated. We propose that the development of a center of excellence that integrates and shares informatics resources for rare diseases sponsored by all of the stakeholders would help foster these initiatives.

  11. Endangered and threatened plant species on the Department of Energy Oak Ridge Reservation: an update

    SciTech Connect

    Parr, P.D.

    1984-10-01

    Plant species considered endangered or threatened on the Department of Energy-Oak Ridge Reservation (DOE-ORR) were identified through a review of pertinent literature and evaluation of herbarium voucher specimens. Thirteen plant species are on the official Tennessee list of endangered and threatened plants. Three of those species have been proposed for inclusion on the Federal list as rare in Tennessee. These rare plants will be given careful consideration in land-use planning. Protection of endangered and threatened species in their native habitat is considered the best method of ensuring their survival. In addition to habitat preservation, natural history studies of the rare species is important in determ

  12. Rare decays in quark flavour physics

    NASA Astrophysics Data System (ADS)

    Albrecht, Johannes; LHCb Collaboration

    2016-04-01

    Rare heavy-flavour decays are an ideal place to search for the effects of potential new particles that modify the decay rates or the Lorentz structure of the decay vertices. Recent results on Flavour Changing Neutral Current decays from the LHC are reviewed. An emphasis is put on the very rare decay Bs0 →μ+μ-, which was recently observed by the CMS and LHCb experiments, on a recent test of lepton universality in loop processes and on the analysis of the angular distributions of the B0 →K*0μ+μ- decays, both by the LHCb collaboration.

  13. Bilateral kidney matrix stones: a rare case

    PubMed Central

    Lahyani, Mounir; Rhannam, Yassine; Slaoui, Amine; Touzani, Alae; Karmouni, Tarik; Elkhader, Khalid; Koutani, Abdellatif; Andaloussi, Ahmed Ibn attya

    2016-01-01

    Kedney matrix stones are a rare form of calculi. Flank pain and urinary tract infections (UTI) are the most common presentations of matrix calculi. The diagnosis is usually made at surgery, but some preoperative radiographic findings might be suggestive. Open surgery was the method of choice for treatment. However, combination of ureterorenoscopy and percutaneous nephrolithotomy (PCNL) was found to be safe and effective. We report a rare case of renal and ureteral matrix stones that were diagnosed and treated by open surgery. We also describe its clinical, radiological and therapeutic features through a review of the literature. PMID:28292065

  14. Poland syndrome with a rare association.

    PubMed

    Gude, Dilip; Rayudu, Batta Ramasubba; Bansa, Dharam; Sashidhar, Chennamsetty

    2012-09-01

    Poland syndrome is a rare congenital anomaly typically characterized by unilateral chest wall hypoplasia and ipsilateral hand abnormalities. Occasionally functionally debilitating, the disorder is mostly benign in nature with the severe deformities requiring surgical correction. A need to watch for possible malignant associations is also warranted. We present a case of a young female with the quintessential features of Poland syndrome with a relatively rare association of ipsilateral renal hypoplasia. We review the literature and discuss the possible renal complications that may arise and their management.

  15. Mediastinal granuloma: a rare cause of dysphagia.

    PubMed

    Micic, Dejan; Hogarth, Douglas Kyle; Kavitt, Robert T

    2016-06-14

    Dysphagia is commonly attributed to disorders arising from dysfunction of the oesophageal mucosa or oesophageal motility. Mediastinal structures causing compression of the oesophagus remain a rare presenting cause of dysphagia. We report a case of a woman presenting with dysphagia to solid foods and associated symptoms of weight loss. Traditional evaluation for dysphagia was unrevealing until cross-sectional imaging suggested a mediastinal obstructive process. The finding of a mediastinal granuloma, distinct from mediastinal fibrosis, as the aetiology of dysphagia is a rare finding, with specific treatment implications. The patient was treated with itraconazole antifungal therapy with an improvement in her symptoms.

  16. Intermultiplet transitions in rare-earth metals

    SciTech Connect

    Stirling, W.G.; McEwen, K.A.; Loong, C.K.

    1985-01-01

    We report here on direct observations of intermultiplet (IM) transitions in the rare-earth metals, Pr, Nd and Tb, made using the chopper spectrometers at the Intense Pulsed Neutron Source of Argonne National Laboratory. Despite hydrogen contamination of the polycrystalline samples, we have observed inelastic peaks at small Q arising from IM transitions in Pr (approx.260 MeV), Nd (approx.242 MeV) and Tb (approx.256 MeV) although the latter has not yet been observed unambiguously. Future work will investigate the energy level structure and dynamical properties of rare-earth ions in stoichiometric metallic systems. 5 refs., 3 figs.

  17. Forward flux sampling for rare event simulations.

    PubMed

    Allen, Rosalind J; Valeriani, Chantal; Rein Ten Wolde, Pieter

    2009-11-18

    Rare events are ubiquitous in many different fields, yet they are notoriously difficult to simulate because few, if any, events are observed in a conventional simulation run. Over the past several decades, specialized simulation methods have been developed to overcome this problem. We review one recently developed class of such methods, known as forward flux sampling. Forward flux sampling uses a series of interfaces between the initial and final states to calculate rate constants and generate transition paths for rare events in equilibrium or nonequilibrium systems with stochastic dynamics. This review draws together a number of recent advances, summarizes several applications of the method and highlights challenges that remain to be overcome.

  18. Sampling rare switching events in biochemical networks.

    PubMed

    Allen, Rosalind J; Warren, Patrick B; Ten Wolde, Pieter Rein

    2005-01-14

    Bistable biochemical switches are widely found in gene regulatory networks and signal transduction pathways. Their switching dynamics are difficult to study, however, because switching events are rare, and the systems are out of equilibrium. We present a simulation method for predicting the rate and mechanism of the flipping of these switches. We apply it to a genetic switch and find that it is highly efficient. The path ensembles for the forward and reverse processes do not coincide. The method is widely applicable to rare events and nonequilibrium processes.

  19. Xanthogranulomatous Prostatitis, a Rare Prostatic Entity.

    PubMed

    Noyola, Alejandro; Gil, José Fernando; Lujano, Heriberto; Piñon, Omar; Muñoz, Gabriel; Michel, José Manuel; Garcia, Jorge; Valdez, Jorge; Morales, Omar

    2017-01-01

    There are several benign prostatic pathologies that can clinically mimic a prostate adenocarcinoma. Xanthogranulomatous prostatitis is a benign inflammatory condition of the prostate and a rare entity. A 47-year old male, with 3 years of lower urinary tract symptoms, with a palpable hypogastric tumor, digital rectal examination: solid prostate, of approximately 60 g. Initial PSA was 0.90 ng/mL. He underwent surgical excision of the lower abdominal nodule and prostatectomy. Histopathology showed xanthogranulomatous prostatitis, without malignancy. Xanthogranulomatous prostatitis is an extremely rare entity that can simulate prostate adenocarcinoma, therefore having a correct histopathological diagnosis is essential.

  20. Ciliates and the rare biosphere: a review.

    PubMed

    Dunthorn, Micah; Stoeck, Thorsten; Clamp, John; Warren, Alan; Mahé, Frédéric

    2014-01-01

    Here we provide a brief review of the rare biosphere from the perspective of ciliates and other microbial eukaryotes. We trace research on rarity from its lack of much in-depth focus in morphological and Sanger sequencing projects, to its central importance in analyses using high throughput sequencing strategies. The problem that the rare biosphere is potentially comprised of mostly errors is then discussed in the light of asking community-comparative, novel-diversity, and ecosystem-functioning questions. © 2014 The Author(s) Journal of Eukaryotic Microbiology © 2014 International Society of Protistologists.

  1. Physics of a Rare Isotope Accelerator

    NASA Astrophysics Data System (ADS)

    Geesaman, D. F.; Gelbke, C. K.; Janssens, R. V. F.; Sherrill, B. M.

    2006-11-01

    Major progress in nuclear research and in observations of the cosmos has made it clear that critical issues in understanding the nucleus and astrophysical processes require abundant new sources of exotic nuclei, away from the realm of the stable ones. Recent advances in accelerator and isotope-production technology make access to these rare isotopes possible. This review examines the impact of the new reach in physics provided by a rare isotope accelerator in nuclear structure, astrophysics, and searches for physics beyond the standard model. We also touch briefly on some of the benefits of these isotopes for other important societal needs.

  2. Replacing the Rare Earth Intellectual Capital

    SciTech Connect

    Gschneidner, Jr., Karl

    2011-04-01

    The rare earth crisis slowly evolved during a 10 to 15 year period beginning in the mid-1980s, when the Chinese began to export mixed rare earth concentrates. In the early 1990s, they started to move up the supply chain and began to export the individual rare earth oxides and metals. By the late 1990s the Chinese exported higher value products, such as magnets, phosphors, polishing compounds, catalysts; and in the 21st century they supplied finished products including electric motors, computers, batteries, liquid-crystal displays (LCDs), TVs and monitors, mobile phones, iPods and compact fluorescent lamp (CFL) light bulbs. As they moved to higher value products, the Chinese slowly drove the various industrial producers and commercial enterprises in the US, Europe and Japan out of business by manipulating the rare earth commodity prices. Because of this, the technically trained rare earth engineers and scientists who worked in areas from mining to separations, to processing to production, to manufacturing of semifinished and final products, were laid-off and moved to other fields or they retired. However, in the past year the Chinese have changed their philosophy of the 1970s and 1980s of forming a rare earth cartel to control the rare earth markets to one in which they will no longer supply the rest of the world (ROW) with their precious rare earths, but instead will use them internally to meet the growing demand as the Chinese standard of living increases. To this end, they have implemented and occasionally increased export restrictions and added an export tariff on many of the high demand rare earth elements. Now the ROW is quickly trying to start up rare earth mines, e.g. Molycorp Minerals in the US and Lynas Corp. in Australia, to cover this shortfall in the worldwide market, but it will take about five years for the supply to meet the demand, even as other mines in the ROW become productive. Unfortunately, today there is a serious lack of technically trained

  3. Endangered Plants in Oregon and Washington.

    ERIC Educational Resources Information Center

    Love, Rhoda M.

    1985-01-01

    Presents a partial list of the 132 Oregon and Washington plants which have been proposed for federal protection under the Endangered Species Act. Suggestions for student/citizen involvement in preserving these species and a description of a videotape about rare/endangered species of the Willamette Valley (Oregon) are included. (DH)

  4. Endangered Plants in Oregon and Washington.

    ERIC Educational Resources Information Center

    Love, Rhoda M.

    1985-01-01

    Presents a partial list of the 132 Oregon and Washington plants which have been proposed for federal protection under the Endangered Species Act. Suggestions for student/citizen involvement in preserving these species and a description of a videotape about rare/endangered species of the Willamette Valley (Oregon) are included. (DH)

  5. Functional rare males in diploid parthenogenetic Artemia.

    PubMed

    Maccari, M; Gómez, A; Hontoria, F; Amat, F

    2013-09-01

    Functional males that are produced occasionally in some asexual taxa - called 'rare males' - raise considerable evolutionary interest, as they might be involved in the origin of new parthenogenetic lineages. Diploid parthenogenetic Artemia produce rare males, which may retain the ability to mate with females of related sexual lineages. Here, we (i) describe the frequency of male progeny in populations of diploid parthenogenetic Artemia, (ii) characterize rare males morphologically, (iii) assess their reproductive role, using cross-mating experiments with sexual females of related species from Central Asia and characterize the F1 hybrid offspring viability and (iv) confirm genetically both the identity and functionality of rare males using DNA barcoding and microsatellite loci. Our result suggests that these males may have an evolutionary role through genetic exchange with related sexual species and that diploid parthenogenetic Artemia is a good model system to investigate the evolutionary transitions between sexual species and parthenogenetic strains. © 2013 The Authors. Journal of Evolutionary Biology © 2013 European Society For Evolutionary Biology.

  6. [Meckel Gruber syndrome: about a rare case].

    PubMed

    Itchimouh, Sanaa; Khabtou, Karima; Mahdaoui, Sakher; Boufettal, Houssine; Samouh, Naima

    2016-01-01

    Meckel Gruber syndrome is a rare autosomal recessive polymalformation syndrome characterized by occipital encephalocele, polydactyly and cystic renal dysplasia. Ultrasound is, at present, the best tool for prenatal screening of this lethal polymalformation and diagnosys is confirmed by karyotyping. We here report a case of Meckel Gruber syndrome detected by ultrasound. Abortion was performed at 25 weeks of amenorrhoea.

  7. Sporotrichoid lupus vulgaris: A rare presentation.

    PubMed

    Maheshwari, Anshul; Tiwari, Siddhi; Mathur, Deepak K; Bhargava, Puneet

    2015-01-01

    Lupus vulgaris is the most common presentation of cutaneous tuberculosis in India and can present as papular, nodular, plaque, ulcerative, vegetating, and tumid forms. Unusual variants include the frambesiform, gangrenous, ulcerovegetating, lichen simplex chronicus, myxomatous, and sporotrichoid types. We describe a rare sporotrichoid presentation of lupus vulgaris on the leg of a 28-year-old female of 12 years duration.

  8. Sporotrichoid lupus vulgaris: A rare presentation

    PubMed Central

    Maheshwari, Anshul; Tiwari, Siddhi; Mathur, Deepak K.; Bhargava, Puneet

    2015-01-01

    Lupus vulgaris is the most common presentation of cutaneous tuberculosis in India and can present as papular, nodular, plaque, ulcerative, vegetating, and tumid forms. Unusual variants include the frambesiform, gangrenous, ulcerovegetating, lichen simplex chronicus, myxomatous, and sporotrichoid types. We describe a rare sporotrichoid presentation of lupus vulgaris on the leg of a 28-year-old female of 12 years duration. PMID:25821736

  9. Histoid leprosy: a rare exuberant case*

    PubMed Central

    de Andrade, Pedro Jose Secchin; Messias, Sulamita dos Santos Nascimento Dutra; Ferreira, Paola Cristina Brandão Oliveira; Sales, Anna Maria; Machado, Alice de Miranda; Nery, José Augusto da Costa

    2015-01-01

    Leprosy is a neglected disease. We point up the need of recognizing the unusual clinical presentations of the disease in order to make early diagnosis and proper treatment possible, and break the transmission chain. The authors report a rare type of multibacillary leprosy: histoid leprosy and present images of numerous well-circumscribed indurated papules and nodules distributed throughout the entire body. PMID:26560226

  10. Progress in methods for rare variant association.

    PubMed

    Santorico, Stephanie A; Hendricks, Audrey E

    2016-02-03

    Empirical studies and evolutionary theory support a role for rare variants in the etiology of complex traits. Given this motivation and increasing affordability of whole-exome and whole-genome sequencing, methods for rare variant association have been an active area of research for the past decade. Here, we provide a survey of the current literature and developments from the Genetics Analysis Workshop 19 (GAW19) Collapsing Rare Variants working group. In particular, we present the generalized linear regression framework and associated score statistic for the 2 major types of methods: burden and variance components methods. We further show that by simply modifying weights within these frameworks we arrive at many of the popular existing methods, for example, the cohort allelic sums test and sequence kernel association test. Meta-analysis techniques are also described. Next, we describe the 6 contributions from the GAW19 Collapsing Rare Variants working group. These included development of new methods, such as a retrospective likelihood for family data, a method using genomic structure to compare cases and controls, a haplotype-based meta-analysis, and a permutation-based method for combining different statistical tests. In addition, one contribution compared a mega-analysis of family-based and population-based data to meta-analysis. Finally, the power of existing family-based methods for binary traits was compared. We conclude with suggestions for open research questions.

  11. Neurofibromatosis type II: a rare neurocutaneous syndrome.

    PubMed

    Sultan, Tipu; Khan, Ashfa Ameer; Malik, Muhammad Akbar; Nadeem, Malik Muhammad; Rahman, Mahfooz-Ur-; Khan, Malik Muhammad Nazir

    2007-06-01

    Neurocutaneous syndromes are heterogeneous group of disorders with abnormalities of central as well as peripheral nervous system. Neurofibromatosis type II (NF-II) is an autosomal dominant neurocutaneous syndrome rarely diagnosed in pediatric population. Diagnosis is based on clinical history and radioimaging. We present a 14 years old boy with headache and decreased hearing, who turned to be a case of neurofibromatosis type II.

  12. CEMARA an information system for rare diseases.

    PubMed

    Landais, Paul; Messiaen, Claude; Rath, Ana; Le Mignot, Loïc; Dufour, Eric; Ben Said, Mohamed; Jais, Jean-Philippe; Toubiana, Laurent; Baujat, Geneviève; Bourdon-Lanoy, Eva; Gérard-Blanluet, Marion; Bodemer, Christine; Salomon, Rémi; Aymé, Ségolène; Le Merrer, Martine; Verloes, Alain

    2010-01-01

    Rare diseases cover a group of conditions characterized by a low prevalence, affecting less than 1 in 2,000 people; 5000 to 7000 rare diseases have been currently identified in Europe. Most diseases do not have any curative treatment. They represent thus an important public health concern. CEMARA is based on a n-tier architecture. Its main objective is to collect continuous and complete records of patients with rare diseases, and their follow-up through a web-based Information System, and to analyse the epidemiological patterns. In France, 41 out of 131 labelled Reference Centres (RC) are sharing CEMARA. Presently 56,593 cases have been registered by more than 850 health care professionals belonging to 171 clinical sites. The national demand of care was explored in relation with the offer of care in order to reach an improved match. Within 2 years, CEMARA stimulated sharing a common platform, a common ontology with Orphanet and initiating new cohorts of rare diseases for improving patient care and research.

  13. Aging in Rare Intellectual Disability Syndromes

    ERIC Educational Resources Information Center

    Dykens, Elisabeth M.

    2013-01-01

    This review highlights several methodological challenges involved in research on aging, health, and mortality in adults with rare intellectual disability syndromes. Few studies have been performed in this area, with research obstacles that include: the ascertainment of older adults with genetic versus clinical diagnoses; likelihood that adults…

  14. Crystalline rare-earth activated oxyorthosilicate phosphor

    DOEpatents

    McClellan, Kenneth J.; Cooke, D. Wayne

    2004-02-10

    Crystalline, transparent, rare-earth activated lutetium oxyorthosilicate phosphor. The phosphor consists essentially of lutetium yttrium oxyorthosilicate activated with a rare-earth metal dopant M and having the general formula Lu(.sub.2-x-z)Y.sub.x M.sub.z SiO.sub.5, wherein 0.00.ltoreq.x.ltoreq.1.95, wherein 0.001.ltoreq.z.ltoreq.0.02, and wherein M is selected from Sm, Tb, Tm, Eu, Yb, and Pr. The phosphor also consists essentially of lutetium gadolinium oxyorthosilicate activated with a rare-earth metal dopant M and having the general formula Lu(.sub.2-x-z)Gd.sub.x M.sub.z SiO.sub.5, wherein 0.00.ltoreq.x.ltoreq.1.95, wherein 0.001.ltoreq.z.ltoreq.0.02, and wherein M is selected from Sm, Tb, Tm, Eu, Yb, and Pr. The phosphor also consists essentially of gadolinium yttrium oxyorthosilicate activated with a rare-earth metal dopant M and having the general formula Gd(.sub.2-x-z)Y.sub.x M.sub.z SiO.sub.5, wherein 0.00.ltoreq.x.ltoreq.1.95, wherein 0.001.ltoreq.z.ltoreq.0.02, and wherein M is selected from Sm, Tb, Tm, Eu, Yb, and Pr. The phosphor may be optically coupled to a photodetector to provide a radiation detector.

  15. Investing in Rare Books and Manuscripts

    PubMed Central

    Liebert, Herman W.

    1981-01-01

    The lecture treats the rapidly escalating values of rare books and manuscripts both as financial and as scholarly investments. The text suggests new areas for collecting which may be pursued in today's market with an eye to an increasing intellectual and monetary return. PMID:7324508

  16. Rare prenylated flavonoids from Tephrosia purpurea.

    PubMed

    Hegazy, Mohamed-Elamir F; Abd el-Razek, Mohamed H; Nagashima, Fumihiro; Asakawa, Yoshinori; Paré, Paul W

    2009-01-01

    Chemical investigations of aerial parts of Tephrosia purpurea yielded the rare prenylated flavonoids, tephropurpulin A (1) and isoglabratephrin (2), in addition to a previously identified flavonoid, glabratephrin (3). Structures were established by 1D and 2D NMR spectroscopy, as well as by HR-MS analysis; for compounds 2 and 3, structures were confirmed by X-ray analysis.

  17. Non-rare earth magnetic nanoparticles

    DOEpatents

    Carpenter, Everett E.; Huba, Zachary J.; Carroll, Kyler J.; Farghaly, Ahmed; Khanna, Shiv N.; Qian, Meichun; Bertino, Massimo

    2017-09-26

    Continuous flow synthetic methods are used to make single phase magnetic metal alloy nanoparticles that do not contain rare earth metals. Soft and hard magnets made from the magnetic nanoparticles are used for a variety of purposes, e.g. in electric motors, communication devices, etc.

  18. Rare earth chemical and physical metallurgy

    SciTech Connect

    Gschneidner, K.A. Jr.

    1985-01-01

    The current state of the rare earth field is reviewed in the areas of basic research, applied research and technology, and commercial utilization. The role of China and its influence, as viewed by an outsider, is briefly summarized. The final third of the paper deals with one aspect of the author's research interests - the quenching of spin fluctuations in exchange enhanced paramagnets.

  19. Selected rare earth sulfides in thermoelectric applications

    SciTech Connect

    Raag, V.; Borodovsky, Y.

    1981-01-01

    This paper discusses preliminary results on the preparation and the measurement of thermoelectric properties of various rare earth sulfides of the stoichiometry R/sub 2/S/sub 3/. A preparation method that enables the rapid and predictable preparation of the sulfides has been discussed, along with some preliminary results on the measurement of thermoelectric properties of these sulfides.

  20. [Inverted papiloma and its rare forms].

    PubMed

    Bugová, G; Jeseňák, M; Wallenfels, P; Ondrušová, B; Hajtman, A

    2014-01-01

    Authors address the issue of a frequent benign tumour of the nasal cavity and paranasal sinuses -  inverted papilloma. They analyse the available diagnostic methods and treatment options. On the background of selected case reports of a rare malignant transformation they emphasize the need for longterm dispensarization as a part of management plan for patients with this oncological disease.

  1. Megaloblastic anemia--a rare cause.

    PubMed

    Debnath, Sanjib Kr; Aggarwal, Anju; Mittal, Hema

    2011-10-01

    A 2- year- old boy presented with non responsive megaloblastic anemia, growth failure and developmental delay. Blood levels of B(12), folic acid and iron were normal. Tandem mass spectroscopy for common inborn errors of metabolism did not reveal any abnormality. There was an increased excretion of orotic acid in urine. The authors report this as a rare cause of megaloblastic anemia.

  2. Sylvian Fissure Dermoid Cyst - A Rare case

    PubMed Central

    Anand, Deepak; Soin, Divya; Garg, Ravinder

    2014-01-01

    Intracranial dermoid cysts are rare tumours which usually occur in the midline. Sylvian fissure is a very unusual site for this lesion. This case presents a patient with unruptured dermoid cyst in the left sylvian fissure who was operated successfully without any residual deficit. PMID:25386502

  3. Rare Books for Research: Separately Housed Collections.

    ERIC Educational Resources Information Center

    Bidwell, John

    1983-01-01

    This discussion of America's outstanding rare book libraries notes the inception of collections, library facilities, technical difficulties, reference services, publicity efforts, and research. The John Carter Brown Library at Brown University, Clark Library of the University of California, and the Folger Shakespeare Library in Washington, D.C.…

  4. Imaging in the diagnosis of rare diseases.

    PubMed

    Bekiesińska-Figatowska, Monika

    2015-01-01

    A disease is considered rare if it affects no more than 5 in 10,000 people. More than six thousand rare diseases have been detected so far and they affect 6-8% of the population which equals 2.3-3 million people in Poland. Some of the rare diseases are already diagnosed in utero, e.g. skeletal dysplasias on ultrasonography or central nervous system diseases on magnetic resonance imaging (MRI). Many cases are finally diagnosed after radiologist's suggestion in a radiological report. Although diagnostic imaging cannot be considered as a basis for diagnosis of most of rare diseases, these studies represent an important element in the diagnostic chain. The complicated and long process of diagnosis may be significantly shortened by suggestions of the radiologist, based on the observation of these elements of radiological appearance of the lesions that are characteristic for a particular group of diseases, or even for a particular disease entity. However, the absolute condition for success is the close clinical-radiological cooperation, with clinicians providing the radiologists with their knowledge of patient's history, clinical manifestations, and the results of other investigations.

  5. Rare Cell Capture in Microfluidic Devices

    PubMed Central

    Pratt, Erica D.; Huang, Chao; Hawkins, Benjamin G.; Gleghorn, Jason P.; Kirby, Brian J.

    2010-01-01

    This article reviews existing methods for the isolation, fractionation, or capture of rare cells in microfluidic devices. Rare cell capture devices face the challenge of maintaining the efficiency standard of traditional bulk separation methods such as flow cytometers and immunomagnetic separators while requiring very high purity of the target cell population, which is typically already at very low starting concentrations. Two major classifications of rare cell capture approaches are covered: (1) non-electrokinetic methods (e.g., immobilization via antibody or aptamer chemistry, size-based sorting, and sheath flow and streamline sorting) are discussed for applications using blood cells, cancer cells, and other mammalian cells, and (2) electrokinetic (primarily dielectrophoretic) methods using both electrode-based and insulative geometries are presented with a view towards pathogen detection, blood fractionation, and cancer cell isolation. The included methods were evaluated based on performance criteria including cell type modeled and used, number of steps/stages, cell viability, and enrichment, efficiency, and/or purity. Major areas for improvement are increasing viability and capture efficiency/purity of directly processed biological samples, as a majority of current studies only process spiked cell lines or pre-diluted/lysed samples. Despite these current challenges, multiple advances have been made in the development of devices for rare cell capture and the subsequent elucidation of new biological phenomena; this article serves to highlight this progress as well as the electrokinetic and non-electrokinetic methods that can potentially be combined to improve performance in future studies. PMID:21532971

  6. [Basal cell carcinoma and rare form variants].

    PubMed

    Liersch, J; Schaller, J

    2014-09-01

    Basal cell carcinomas are the most common primary cutaneous malignant neoplasms. The diagnosis of basal cell carcinoma represents a common and routine task for pathologists and dermatopathologists. The aim of this review is the clinical and histopathological presentation of the most common subtypes of basal cell carcinoma. Furthermore, the rare variants of basal cell carcinoma and their differential diagnoses are also discussed.

  7. A rare case of NUT midline carcinoma.

    PubMed

    Ball, Allison; Bromley, Amy; Glaze, Sarah; French, Christopher A; Ghatage, Prafull; Köbel, Martin

    2012-01-01

    ► NUT midline carcinoma is a rare and aggressive cancer arising in midline structures and is of squamous cell lineage. ► Diagnosis by use of molecular tests is possible with clinical suspicion. ► NUT midline carcinoma is refractory to conventional treatments, but understanding of molecular alterations may lead to an effective therapy.

  8. Limits on rare D-meson decays

    SciTech Connect

    Grab, C.

    1987-07-01

    The latest results from a number of experiments on searches for rare decays of the charmed D-mesons are summarized. This talk reports on upper limits on flavor changing weak neutral current reactions and on processes that do not conserve the lepton family number.

  9. Aging in Rare Intellectual Disability Syndromes

    ERIC Educational Resources Information Center

    Dykens, Elisabeth M.

    2013-01-01

    This review highlights several methodological challenges involved in research on aging, health, and mortality in adults with rare intellectual disability syndromes. Few studies have been performed in this area, with research obstacles that include: the ascertainment of older adults with genetic versus clinical diagnoses; likelihood that adults…

  10. [Epithelioid hemangioendothelioma: a rare hepatic tumor].

    PubMed

    Botella, M T; Cabrera, T; Sebastián, J J; Navarro, M J; Alvarez, R; Uribarrena, R

    1995-10-01

    We present a case of epithelioid hemangioendothelioma of the liver (EHL). The imaging techniques did not permit the diagnosis. A liver biopsy was done under laparoscopy. One year later, the patient remains without symptoms in spite of the presence of lung metastases and the therapeutic abstention. The most outstanding aspects of this rare hepatic tumor are discussed.

  11. What about the rare-earth elements

    USDA-ARS?s Scientific Manuscript database

    There is insufficient understanding of the nutritional physiology of pecan trees and orchards; thus, affecting nutmeat yield and quality, disease resistance and alternate bearing. An analysis of the rare-earth element composition of pecan and related hickory cousins found that they hyperaccumulate ...

  12. Melorheostosis: a rare entity: a case report.

    PubMed

    Kherfani, Abdelhakim; Mahjoub, Hachem

    2014-01-01

    Melorheostosis is a rare entity belonging to the group of sclerotic bone dysplasias. Described for the first time in 1922 by Leri, it remains imperfectly known as clinical presentations are highly variable, and the etiological diagnosis is not fully elucidated. We report a case of polyostoticmelorheostosis for which radiological investigations were complete, in order to study this disease.

  13. Melorheostosis: a rare entity: a case report

    PubMed Central

    Kherfani, Abdelhakim; Mahjoub, Hachem

    2014-01-01

    Melorheostosis is a rare entity belonging to the group of sclerotic bone dysplasias. Described for the first time in 1922 by Leri, it remains imperfectly known as clinical presentations are highly variable, and the etiological diagnosis is not fully elucidated. We report a case of polyostoticmelorheostosis for which radiological investigations were complete, in order to study this disease. PMID:25489356

  14. Prioritizing Rare Variants with Conditional Likelihood Ratios

    PubMed Central

    Li, Weili; Dobbins, Sara; Tomlinson, Ian; Houlston, Richard; Pal, Deb K.; Strug, Lisa J.

    2016-01-01

    Background Prioritizing individual rare variants within associated genes or regions often consists of an ad hoc combination of statistical and biological considerations. From the statistical perspective, rare variants are often ranked using Fisher’s exact p values, which can lead to different rankings of the same set of variants depending on whether 1- or 2-sided p values are used. Results We propose a likelihood ratio-based measure, maxLRc, for the statistical component of ranking rare variants under a case-control study design that avoids the hypothesis-testing paradigm. We prove analytically that the maxLRc is always well-defined, even when the data has zero cell counts in the 2×2 disease-variant table. Via simulation, we show that the maxLRc outperforms Fisher’s exact p values in most practical scenarios considered. Using next-generation sequence data from 27 rolandic epilepsy cases and 200 controls in a region previously shown to be linked to and associated with rolandic epilepsy, we demonstrate that rankings assigned by the maxLRc and exact p values can differ substantially. Conclusion The maxLRc provides reliable statistical prioritization of rare variants using only the observed data, avoiding the need to specify parameters associated with hypothesis testing that can result in ranking discrepancies across p value procedures; and it is applicable to common variant prioritization. PMID:25659987

  15. Other rare processes with DAMA/LIBRA

    NASA Astrophysics Data System (ADS)

    di Marco, A.; Cappella, F.; Cerulli, R.

    2016-10-01

    DAMA/NaI and DAMA/LIBRA data have allowed the study of several rare processes. In this paper, the results obtained for internal pair production in 241Am α decay, charge not conserving electron capture in 127I and possible processes violating the Pauli Exclusion Principle are briefly discussed.

  16. Fournier gangrene: rare complication of rectal cancer.

    PubMed

    Ossibi, Pierlesky Elion; Souiki, Tarik; Ibn Majdoub, Karim; Toughrai, Imane; Laalim, Said Ait; Mazaz, Khalid; Tenkorang, Somuah; Farih, My Hassan

    2015-01-01

    Fournier's Gangrene is a rare complication of rectal cancer. Its discovery is often delayed. It's incidence is about 0.3/100,000 populations in Western countries. We report a patient with peritoneal perforation of rectal cancer revealed by scrotal and perineal necrotizing fasciitis.

  17. Tracking rare orchids (Orchidaceae) in Arizona

    Treesearch

    Ronald A. Coleman

    2001-01-01

    Twenty-six native orchid species occur in Arizona, and 14 are considered rare with fewer than 100 occurrences in the state. The author is conducting three studies covering four of the wild orchids: Stenorrhynchos michuacanum, Hexalectris revoluta, Malaxis porphyry, and M. tenuis. The studies are ongoing so only interim results are available. Interim results indicate...

  18. Congenital epulis: A rare benign tumour.

    PubMed

    Wong, D K C; Ramli, R; Muhaizan, W M; Primuharsa Putra, S H A

    2016-10-01

    Congenital epulis is a rare benign pedunculated tumour of the oral cavity arising from the alveolar ridges. It is usually detected in newborns and can be successfully resected surgically. We report a case of a newborn baby who had a 5x3x3cm pedunculated lobar mass arising from the upper alveolar ridge.

  19. Rare tumors of the rectum. Narrative review.

    PubMed

    Errasti Alustiza, José; Espín Basany, Eloy; Reina Duarte, Angel

    2014-11-01

    Most rectal neoplasms are adenocarcinomas, but there is a small percentage of tumors which are of other histological cell lines such as neuroendocrine tumors, sarcomas, lymphomas and squamous cell carcinomas, which have special characteristics and different treatments. We have reviewed these rare tumors of the rectum from a clinical and surgical point of view.

  20. Investigating rare events by transition interface sampling

    NASA Astrophysics Data System (ADS)

    Moroni, Daniele; van Erp, Titus S.; Bolhuis, Peter G.

    2004-09-01

    We briefly review simulation schemes for the investigation of rare transitions and resume the recently introduced transition interface sampling, a method in which the computation of rate constants is recast into the computation of fluxes through interfaces dividing the reactant and product state.