99 research outputs found

    Phylogeny of the carolinense clade of solanum (Solanaceae) inferred from nuclear and plastid DNA sequences

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    pre-printThe large and economically important genus Solanum contains ca. 1,400 species distributed worldwide. One of the 12-14 major clades identified in the genus is the Leptostemonum clade, or the "spiny solanums." Previous molecular phylogenetic studies have identified 14 major clades in the spiny solanums. Among these is the Carolinense clade, which contains Solanum carolinense, the type species of S. subsect. Lathyrocarpum. However, previous results have suggested that the species composition of the Carolinense clade is only partially congruent with taxonomic circumscriptions of S. subsect. Lathyrocarpum. The main goal of this study was to increase taxon sampling over previous molecular phylogenies in order to better understand the composition of the Carolinense clade. We newly sequenced 31 accessions of 17 taxa putatively belonging to the clade for two nuclear (ITS, waxy) and one plastid gene region (trnT-trnF) and combined these with previously generated molecular data. Phylogenetic analyses of separate and combined DNA matrices were done using maximum parsimony and Bayesian methods. Results from analyses of the combined nuclear and plastid data set showed 10 taxa to be resolved within a wellsupported Carolinense clade. However, three species, Solanum dimidiatum, S. perplexum, and S. hieronymi, showed conflicting placements in phylogenies based on analyses of nuclear vs. plastid data sets, suggesting a history of allopolyploidy or introgression. Within the Carolinense clade, the North and South American species were both recovered as well-supported clades, implying a single dispersal event from South to North America

    A hard x ray split and delay unit for the HED experiment at the European XFEL

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    For the High Energy Density HED experiment [1] at the European XFEL [2] an x ray split and delay unit SDU is built covering photon energies from 5 keV up to 20 keV [3]. This SDU will enable time resolved x ray pump x ray probe experiments [4,5] as well as sequential diffractive imaging [6] on a femtosecond to picosecond time scale. Further, direct measurements of the temporal coherence properties will be possible by making use of a linear autocorrelation [7,8]. The set up is based on geometric wavefront beam splitting, which has successfully been implemented at an autocorrelator at FLASH [9]. The x ray FEL pulses are split by a sharp edge of a silicon mirror coated with multilayers. Both partial beams will then pass variable delay lines. For different photon energies the angle of incidence onto the multilayer mirrors will be adjusted in order to match the Bragg condition. For a photon energy of h amp; 957; 20 keV a grazing angle of amp; 952; 0.57 has to be set, which results in a footprint of the beam 6 amp; 963; on the mirror of l 98 mm. At this photon energy the reflectance of a Mo B4C multi layer coating with a multilayer period of d 3.2 nm and N 200 layers amounts to R 0.92. In order to enhance the maximum transmission for photon energies of h amp; 957; 8 keV and below, a Ni B4C multilayer coating can be applied beside the Mo B4C coating for this spectral region. Because of the different incidence angles, the path lengths of the beams will differ as a function of wavelength. Hence, maximum delays between 2.5 ps at h amp; 957; 20 keV and up to 23 ps at h amp; 957; 5 keV will be possibl

    Glial cell type-specific changes in spinal dipeptidyl peptidase 4 expression and effects of its inhibitors in inflammatory and neuropatic pain

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    Altered pain sensations such as hyperalgesia and allodynia are characteristic features of various pain states, and remain difficult to treat. We have shown previously that spinal application of dipeptidyl peptidase 4 (DPP4) inhibitors induces strong antihyperalgesic effect during inflammatory pain. In this study we observed low level of DPP4 mRNA in the rat spinal dorsal horn in physiological conditions, which did not change significantly either in carrageenan-induced inflammatory or partial nerve ligation-generated neuropathic states. In naive animals, microglia and astrocytes expressed DPP4 protein with one and two orders of magnitude higher than neurons, respectively. DPP4 significantly increased in astrocytes during inflammation and in microglia in neuropathy. Intrathecal application of two DPP4 inhibitors tripeptide isoleucin-prolin-isoleucin (IPI) and the antidiabetic drug vildagliptin resulted in robust opioid-dependent antihyperalgesic effect during inflammation, and milder but significant opioid-independent antihyperalgesic action in the neuropathic model. The opioid-mediated antihyperalgesic effect of IPI was exclusively related to mu-opioid receptors, while vildagliptin affected mainly delta-receptor activity, although mu- and kappa-receptors were also involved. None of the inhibitors influenced allodynia. Our results suggest pathology and glia-type specific changes of DPP4 activity in the spinal cord, which contribute to the development and maintenance of hyperalgesia and interact with endogenous opioid systems

    Mosaic Convergence of Rodent Dentitions

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    BACKGROUND:Understanding mechanisms responsible for changes in tooth morphology in the course of evolution is an area of investigation common to both paleontology and developmental biology. Detailed analyses of molar tooth crown shape have shown frequent homoplasia in mammalian evolution, which requires accurate investigation of the evolutionary pathways provided by the fossil record. The necessity of preservation of an effective occlusion has been hypothesized to functionally constrain crown morphological changes and to also facilitate convergent evolution. The Muroidea superfamily constitutes a relevant model for the study of molar crown diversification because it encompasses one third of the extant mammalian biodiversity. METHODOLOGY/PRINCIPAL FINDINGS:Combined microwear and 3D-topographic analyses performed on fossil and extant muroid molars allow for a first quantification of the relationships between changes in crown morphology and functionality of occlusion. Based on an abundant fossil record and on a well resolved phylogeny, our results show that the most derived functional condition associates longitudinal chewing and non interlocking of cusps. This condition has been reached at least 7 times within muroids via two main types of evolutionary pathways each respecting functional continuity. In the first type, the flattening of tooth crown which induces the removal of cusp interlocking occurs before the rotation of the chewing movement. In the second type however, flattening is subsequent to rotation of the chewing movement which can be associated with certain changes in cusp morphology. CONCLUSION/SIGNIFICANCE:The reverse orders of the changes involved in these different pathways reveal a mosaic evolution of mammalian dentition in which direction of chewing and crown shape seem to be partly decoupled. Either can change in respect to strong functional constraints affecting occlusion which thereby limit the number of the possible pathways. Because convergent pathways imply distinct ontogenetic trajectories, new Evo/Devo comparative studies on cusp morphogenesis are necessary

    Contributions in honor of Guy G. Musser.

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    450 p. : ill. (some col.), maps ; 26 cm. "Issued December 15, 2009." Includes bibliographical references.Contents: They sort out like nuts and bolts : a scientific biography of Guy G. Musser / Michael D. Carleton -- Taxonomy, distribution, and natural history of the genus Heteromys ‪(‬Rodentia: Heteromyidae‪)‬ in central and eastern Venezuela, with the description of a new species from the Cordillera de la Costa / Robert P. Anderson and Eliécer E. Gutiérrez -- Review of the Oryzomys couesi complex ‪(‬Rodentia: Cricetidae: Sigmodontinae‪)‬ in western Mexico / Michael D. Carleton and Joaquin Arroyo-Cabrales -- The antiquity of Rhizomys and independent acquisition of fossorial traits in subterranean muroids / Lawrence J. Flynn -- A new species of Reithrodontomys, subgenus Aporodon ‪(‬Cricetidae: Neotominae‪)‬, from the highlands of Costa Rica, with comments on Costa Rican and Panamanian Reithrodontomys / Alfred L. Gardner and Michael D. Carleton -- Phylogenetic relationships of harpyionycterine megabats ‪(‬Chiroptera: Pteropodidae‪)‬ / Norberto P. Giannini, Francisca Cunha Almeida, and Nancy B. Simmons -- A new genus and species of small ‪"‬tree-mouse‪"‬ ‪(‬Rodentia, Muridae‪)‬ related to the Philippine giant cloud rats / Lawrence R. Heaney, Danilo S. Balete, Eric A. Rickart, M. Josefa Veluz, and Sharon A. Jansa -- Biodiversity and biogeography of the moss-mice of New Guinea : a taxonomic revision of Pseudohydromys ‪(‬Muridae: Murinae‪)‬ / Kristofer M. Helgen and Lauren E. Helgen -- Systematic revision of sub-Saharan African dormice ‪(‬Rodentia: Gliridae‪)‬. Part 2, Description of a new species of Graphiurus from the central Congo Basin, including morphological and ecological niche comparisons with G. crassicaudatus and G. lorraineus / Mary Ellen Holden and Rebecca S. Levine -- Descriptions of new species of Crocidura ‪(‬Soricomorpha: Soricidae‪)‬ from mainland Southeast Asia, with synopses of previously described species and remarks on biogeography / Paulina D. Jenkins, Darrin P. Lunde, and Clive B. Moncrieff -- The six opossums of Félix de Azara : identification, taxonomic history, neotype designations, and nomenclatural recommendations / Robert S. Voss, Philip Myers, François Catzeflis, Ana Paula Carmignotto, and Josefina Barreiro -- Skull and dentition of Willeumys korthi, nov. gen. et sp., a cricetid rodent from the Oligocene ‪(‬Orellan‪)‬ of Wyoming / John H. Wahlert

    Les espèces lianescentes de <i>Grewia</i> L. (Malvaceae <i>s.l.</i>, anciennement Tiliaceae) de Madagascar

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    Trois espèces lianescentes de Grewia L. sont décrites de Madagascar, portant à cinq le nombre de représentants du genre sur l’île caractérisés par ce port. Grewia manomboensis G.E. Schatz, Randrian. &amp; Lowry, sp. nov., G. rabehevitrae Randrian., Lowry &amp; G.E. Schatz, sp. nov. et G. rufostellata Randrian., Lowry &amp; G.E. Schatz, sp. nov., qui croissent toutes les trois dans les forêts orientales de basse à moyenne altitude, peuvent être distinguées les unes des autres par plusieurs caractères, dont des différences foliaires (taille, marge et proéminence de la nervation tertiaire), pédicellaires (longueur, diamètre, densité de trichomes), la taille des sépales, le type et la couleur de l’indument, ainsi que par la forme des pétales. Des illustrations sont fournies pour chacun des nouveaux taxons et des photographies pour deux d’entre eux, ainsi qu’une carte de répartition, une première évaluation du statut de conservation pour chaque espèce et une clé d’identification en anglais et en français.Three liana species of Grewia L. are described from Madagascar, bringing to five the members of the genus on the island to exhibit this habit. Grewia manomboensis G.E. Schatz, Randrian. &amp; Lowry, sp. nov., G. rabehevitrae Randrian., Lowry &amp; G.E. Schatz, sp. nov. and G. rufostellata Randrian., Lowry &amp; G.E. Schatz, sp. nov., all three of which occur in low- to mid-elevation humid eastern forest, can be distinguished from one another by several features, including differences in the leaves (size, margin and prominence of the tertiary venation), pedicels (length, diameter and trichome density), sepal size, indument type and color, and petal shape. Illustrations are provided for each new taxon and photographs for two of them, along with a range map, preliminary assessments of the conservation status of each species, and an identification key in English and French.</p

    Skull morphology of Gregorymys and relationships of the Entoptychinae (Rodentia, Geomyidae). American Museum novitates ; ; no. 2922.

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    13 p. : ill. ; 26 cm.Bibliography: p. 12-13

    A New Zygomorphic-Flowered Rinorea (Violaceae) from the Neotropics

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    Volume: 19Start Page: 416End Page: 42
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