548 research outputs found

    The rissaga of 15 June 2006 in Ciutadella (Menorca), a meteorological tsunami

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    An extraordinary "rissaga" event (the local name for high-amplitude sea level oscillations) with 4–5 m of amplitude occurred on 15 June 2006 at Ciutadella (Menorca, Spain). In this paper we describe the rissaga event and propose that the meteorological mechanism responsible for it was an unusual pressure jump, associated with a convective squall line

    Genetic variation for nutrient use efficiency in maize under different tillage and fertilization regimes with special emphasis to plant microbe interaction

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    Conservation tillage (no-till and reduced tillage) brings many benefits with respect to soil fertility and energy use, but it also has drawbacks regarding the need for synthetic fertilizers and herbicides. To promote conversation tillage in organic farming systems, crop rotation, fertilization and weed control have to be optimized. In addition, crop varieties are needed with improved nutrient use efficiency (NUE) and high weed competitiveness or tolerance

    Marsupials (Didelphimorphia).

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    87 pages : illustrations (some color), maps ; 26 cm.This report is the third in our monographic series on mammalian diversity and Matses ethnomammalogy in the Yavarí-Ucayali interfluvial region of northeastern Peru. Based on taxonomic analysis of specimens collected in the region, we document the occurrence of 19 species of marsupials in the genera Caluromys, Glironia, Hyladelphys, Marmosa, Monodelphis, Metachirus, Chironectes, Didelphis, Philander, Gracilinanus, and Marmosops. Our principal taxonomic results include the following: (1) we provide a phylogenetic analysis of previously unpublished mitochondrial DNA (mtDNA) sequence data for Caluromys that supports the reciprocal monophyly of all currently recognized species in the genus but reveals substantial heterogeneity in one extralimital taxon; (2) we explain why Marmosa constantiae is the correct name for the southwestern Amazonian taxon previously known as Mar. demerarae, and we diagnose Mar. constantiae from Mar. rapposa, a superficially similar species from southern Peru, eastern Bolivia, and central Brazil; (3) we explain why Mar. rutteri is the correct name for one of the Amazonian species currently known as Mar. regina, and we restrict the latter name to the transAndean holotype; (4) we recognize Metachirus myosuros as a species distinct from Met. nudicaudatus based on morphological comparisons and a phylogenetic analysis of new mtDNA sequence data; and (5) we name a new species of Marmosops to honor the late Finnish-Peruvian naturalist Pekka Soini. Of the 19 marsupial species known to occur in the Yavarí-Ucayali interfluve, 16 have been recorded in sympatry at Nuevo San Juan, the Matses village where we based most of our fieldwork from 1995 to 1999. We explain why we believe the marsupial species list from Nuevo San Juan to be complete (or nearly so), and we compare it with a species list obtained by similarly intensive fieldwork at Paracou (French Guiana). Although Nuevo San Juan and Paracou are 2500 km apart on opposite sides of Amazonia, the same opossum genera are present at both sites, the lists differing only in the species represented in each fauna. We briefly discuss current explanations for spatial turnover in species of terrestrial vertebrates across Amazonian landscapes and provide evidence that the upper Amazon is a significant dispersal barrier for marsupials. Marsupials are not important to the Matses in any way. In keeping with their cultural inattention to mammals that are inconspicuous, harmless, and too small to be of dietary significance, the Matses lexically distinguish only a few kinds of opossums, and they are not close observers of opossum morphology or behavior

    A new approach to sensitivity climatologies: the DTS-MEDEX-2009 campaign

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    Adaptive observation is an approach to improving the quality of numerical weather forecasts through the optimization of observing networks. It is sometimes referred to as Data Targeting (DT). This approach has been applied to high impact weather during specific field campaigns in the past decade. Adaptive observations may involve various types of observations, including either specific research observing platforms or routine observing platforms employed in an adaptive way. The North-Atlantic TReC 2003 and the EURORISK-PREVIEW 2008 exercises focused on the North-Atlantic and Western Europe areas using mainly routine observing systems. These campaigns also included Mediterranean cases. <br><br> The most recent campaign, DTS-MEDEX-2009, is the first campaign in which the DT method has been used to address exclusively Mediterranean high impact weather events. In this campaign, which is an important stage in the MEDEX development, only operational radiosonde stations and commercial aircraft data (AMDAR) have provided additional observations. Although specific diagnostic studies are needed to assess the impact of the extra-observations on forecast skill and demonstrate the effectiveness of DTS-MEDEX-2009, some preliminary findings can be deduced from a survey of this targeting exercise. <br><br> After a description of the data targeting system and some illustrations of particular cases, this paper attempts some comparisons of additional observation needs (through effectively deployed radio-soundings) with sensitivity climatologies in the Mediterranean. The first step towards a sensitivity climatology for Mediterranean cases of high impact weather is indirectly given by the frequency of extra-soundings launched from the network of radiosonde stations involved in the DTS-MEDEX-2009 campaign

    Riociguat for the treatment of chronic thromboembolic pulmonary hypertension.

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    BACKGROUND: Riociguat, a member of a new class of compounds (soluble guanylate cyclase stimulators), has been shown in previous clinical studies to be beneficial in the treatment of chronic thromboembolic pulmonary hypertension. METHODS: In this phase 3, multicenter, randomized, double-blind, placebo-controlled study, we randomly assigned 261 patients with inoperable chronic thromboembolic pulmonary hypertension or persistent or recurrent pulmonary hypertension after pulmonary endarterectomy to receive placebo or riociguat. The primary end point was the change from baseline to the end of week 16 in the distance walked in 6 minutes. Secondary end points included changes from baseline in pulmonary vascular resistance, N-terminal pro-brain natriuretic peptide (NT-proBNP) level, World Health Organization (WHO) functional class, time to clinical worsening, Borg dyspnea score, quality-of-life variables, and safety. RESULTS: By week 16, the 6-minute walk distance had increased by a mean of 39 m in the riociguat group, as compared with a mean decrease of 6 m in the placebo group (least-squares mean difference, 46 m; 95% confidence interval [CI], 25 to 67; P<0.001). Pulmonary vascular resistance decreased by 226 dyn · sec · cm-5in the riociguat group and increased by 23 dyn · sec · cm-5in the placebo group (least-squares mean difference, -246 dyn · sec · cm-5; 95% CI, -303 to -190; P<0.001). Riociguat was also associated with significant improvements in the NT-proBNP level (P<0.001) and WHO functional class (P = 0.003). The most common serious adverse events were right ventricular failure (in 3% of patients in each group) and syncope (in 2% of the riociguat group and in 3% of the placebo group). CONCLUSIONS: Riociguat significantly improved exercise capacity and pulmonary vascular resistance in patients with chronic thromboembolic pulmonary hypertension. (Funded by Bayer HealthCare; CHEST-1 and CHEST-2 ClinicalTrials.gov numbers, NCT00855465 and NCT00910429, respectively.) Copyright © 2013 Massachusetts Medical Society

    Didelphid marsupials.

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    177 p. : ill. (some col.) ; 26 cm. "Issued June 30, 2009." Includes bibliographical references (p. 142-156).This report summarizes a decade of morphological and molecular research on the phylogenetic relationships of didelphid marsupials (opossums), a substantially intact radiation of New World metatherian mammals. We review the comparative morphology of Recent opossums, emphasizing those anatomical systems from which taxonomically useful information is available for the majority of living genera and species, namely the integument, cranium, and dentition. Morphological similarities and differences among didelphids and other plesiomorphic marsupials (caenolestids, microbiotheriids, dasyurids, and peramelids) are also described. These observations, representing evolved differences in diverse functional-morphological systems, together with karyotypic information gleaned from the literature, provide the basis for coding 129 phylogenetic characters that we scored for 44 ingroup and seven outgroup taxa. Published information about the size, internal organization, chromosomal location, and physiological properties of five nuclear genes (BRCA1, DMP1, IRBP, RAG1, vWF) sequenced for this study suggest that these loci are unlinked, exist as single copies, are active in different tissues, and encode protein products with widely divergent functions. All of the sequenced fragments are long (>900 bp), free of ingroup alignment ambiguities, and translate to open reading frame. Nucleotide data from a total of 7320 aligned sites were obtained from 43 ingroup and seven outgroup taxa. Separate parsimony, likelihood, and Bayesian analyses of these six data partitions (morphology + karyotypes, five genes) resulted in highly congruent estimates of didelphid phylogeny with few examples of conflict among strongly supported nodes. Analyses of concatenated sequences and combined (nonmolecular + sequence) datasets effectively summarize all of the common signal recovered from separate analyses: a completely resolved ingroup phylogeny with high support statistics at most nodes. Remaining problems (not conclusively resolved in this study) include the position of the ingroup root and the relationships of three genera (Chacodelphys, Cryptonanus, Tlacuatzin) within their respective suprageneric clades. The history of didelphid classification is reviewed, and all previous systems are found to contain nonmonophyletic groups. A revised phylogenetic classification consistent with our analytic results includes the following higher taxa: Glironiinae (for Glironia), Caluromyinae (Caluromys and Caluromysiops), Hyladelphinae (Hyladelphys), Didelphinae (Marmosini, Metachirini, Didelphini, and Thylamyini), Marmosini (Marmosa, Monodelphis, and Tlacuatzin), Metachirini (Metachirus), Didelphini (Chironectes, Didelphis, Lutreolina, and Philander), and Thylamyini (Chacodelphys, Cryptonanus, Gracilinanus, Lestodelphys, Marmosops, and Thylamys). The probable relationships of several Neogene fossil genera are also discussed. To facilitate identifications, all Recent genera are redescribed, representative crania are illustrated, and a key is provided.American Museum of Natural History

    Root cap is an important determinant of rhizosphere microbiome assembly

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    Plants impact the development of their rhizosphere microbial communities. It is yet unclear to what extent the root cap and specific root zones contribute to microbial community assembly. To test the roles of root caps and root hairs in the establishment of microbiomes along maize roots (Zea mays), we compared the composition of prokaryote (archaea and bacteria) and protist (Cercozoa and Endomyxa) microbiomes of intact or decapped primary roots of maize inbred line B73 with its isogenic root hairless (rth3) mutant. In addition, we tracked gene expression along the root axis to identify molecular control points for an active microbiome assembly by roots. Absence of root caps had stronger effects on microbiome composition than the absence of root hairs and affected microbial community composition also at older root zones and at higher trophic levels (protists). Specific bacterial and cercozoan taxa correlated with root genes involved in immune response. Our results indicate a central role of root caps in microbiome assembly with ripple-on effects affecting higher trophic levels and microbiome composition on older root zones

    Relationships of New World porcupines.

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    36 p. : ill. (some col.), map ; 26 cm.Phylogenetic analyses of cytochrome-b sequence data from 13 of the 15 currently recognized species of New World porcupines were used to test competing taxonomic hypotheses and to explore scenarios of morphological evolution and biogeography. Consistent with previous studies, the monophyly of Erethizontidae (Chaetomys + Erethizon + Coendou) and the monophyly of Erethizontinae (Erethizon + Coendou) were both strongly supported. However, cytochrome-b sequence data provide no support for the reciprocal monophyly of Coendou, "Echinoprocta," and "Sphiggurus" as those taxa were previously recognized by authors. All of the erethizontid species recognized in recent revisionary work and represented by multiple sequences in this study were recovered as monophyletic groups. Maximum-likelihood (ML) analyses of these data recovered the following phylogeny for 11 species of Coendou: ((melanurus (ichillus (pruinosus + vestitus))) ((spinosus (bicolor + nycthemera)) (prehensilis (mexicanus (quichua + rufescens))))). Ancestral-state reconstructions based on the ML topology suggest that several morphological characters emphasized in past erethizontid classifications (size, nasofrontal sinus inflation, and long fur) have evolved homoplasiously. Maximum-likelihood inference of geographic range evolution suggests that the last common ancestor of living erethizontids was a cis-Andean species, and that most subsequent cladogenesis was also cis-Andean; however, at least two trans-Andean dispersal events are plausibly indicated, as well as two separate invasions of Andean landscapes. Among the most remarkable results of this study are almost-identical sequences of Coendou prehensilis from localities spanning 27° of latitude and 25° of longitude; we speculate that a trophic-niche shift might have allowed rapid range expansion of this species, which accounts for almost all known cases of geographic range overlap and sympatry in the genus Coendou

    Contents of Gracilinanus

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    34 p. : ill. (some col.), map ; 26 cm.Includes bibliographical references (p. 29-30).Five nominal species of small didelphid marsupials previously referred to Gracilinanus differ conspicuously from the type species (G. microtarsus) and from all of the other valid taxa that we recognize as members of that genus (G. aceramarcae, G. agilis, G. dryas, G. emiliae, G. marica). These anomalous forms can be distinguished morphologically from Gracilinanus (in the strict sense just defined) by lacking maxillary palatal vacuities, a secondary foramen ovale, and a rostral process of the premaxillae; in addition, P3 is taller than P2, and accessory cusps are often present on C1. A new genus, Cryptonanus, is described to contain these forms, all of which are provisionally recognized as valid species: C. agricolai, C. chacoensis, C. guahybae, C. ignitus, and C. unduaviensis. Separate and combined phylogenetic analyses of nonmolecular data and nuclear gene sequences suggest that Cryptonanus and Gracilinanus (sensu stricto) are reciprocally monophyletic and closely related, although they were not consistently recovered as sister taxa in any analysis. Available specimen records document that Cryptonanus is widely distributed in mostly unforested tropical, subtropical, and temperate biomes south of the Amazon River (from ca. 7°S in the Brazilian state of Ceará to ca. 34°S in the Argentinian province of Buenos Aires), but significant range extensions could be expected from pitfall trapping in extralimital savanna landscapes. Scant field data suggest that species of Cryptonanus may often be associated with wet or seasonally inundated grasslands, an unusual habitat for small didelphids

    Tests for Positive Selection on Immune and Reproductive Genes in Closely Related Species of the Murine Genus Mus

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    AbstractPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/42372/1/30560294.pd
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