176 research outputs found

    Additions, combinations, and synonyms for the Bolivian moss flora

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    Fifty-five mosses are newly recorded for Bolivia. Additional collection data are given for twelve mosses considered little known or rare in the country. Six new synonyms are recognized, five from Bolivia, one from Brazil: Hookeria scabripes Müll. Hal. [Callicostella scabripes (Müll. Hal.) Broth.] = Callicostella pallida (Hornsch.) Ångstr.; Leucobryum fragile Herzog = Leucobryum subobtusifolium (Broth.) B.H. Allen; Macromitrium pinnulatum Herzog = Macromitrium microstomum (Hook. & Grev.) Schwägr.; Schlotheimia vesiculata Herzog [Macromitrium vesiculatum (Herzog) Herzog] = Macromitrium stellulatum (Hornsch.) Brid.; Cyclodictyon breve Herzog = Cyclodictyon albicans (Hedw.) Kuntze; and from Brazil: Callicostella paludicola Broth. = Callicostella merkelii (Hornsch.) A. Jaeger. Three new combinations are proposed: Entosthodon subaloma (Herzog) S.P. Churchill (Goniobryum subaloma Herzog), Syntrichia xerophila (Herzog) S.P. Churchill (Tortula xerophila Herzog), Thamniopsis lepidopiloides (Herzog) S.P. Churchill (Hookeriopsis lepidopiloides Herzog)

    Bryologia novo granatensis : estudios de los musgos de colombia IV ; catalogo nuevo de los musgos de colombia

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    A revised moss checklist for Colombia recognizes 877 species distributed among 242 genera and 65 families. Departmental distribution is provided for all species. This paper is based on the previous checklist by Florschütz-de Waard & Florschütz (1979), publications since that time, on the extensive holdings of the New York Botanical Garden, the Institute of Systematic Botany, Utrecht, and other herbaria, and on recent field work. Included in this list are a number of the collections made by Aguirre C., Cleef, Griffin, Killip, Schultes, Steere, van der Hammen and van Reenen, among others, which have not previously been incorporated into the Colombian moss literature. Comparison of the number of species reported for each of the departments based on the 1979 and the present checklist both suggest that over half of the departments are poorly known. Forty new additions to Colombia are provided in this catalogue: Amblystegium serpens, Anoectangium aestivum, Astomiopsis amblycalyx, Breutelia brevifolia, Brymela parkeriana, Bryohaplocladium praelongum, Bryum coloratum, B. perlimbatum, Chorisodontium setaceum, Dicranum peruvianum, Drepanocladus uncinatus, Encalypta asperifolia, Entodon hampeanus, Epipterygium immarginatum, Fissidens allionii, F. diplodus, F. intermedius, Groutiella obtusa, Gymnostomum recurvirostrum, Hymenodon reggaeus, Leiomela ecuadorensis, Lepidopilum affine, L. cuspidans, L. cubense, Leptodontium stellaticuspis, Leskea plumaria, Leskeadelphus bolivianus, Neckera urnigera, Potamium deceptivum, P. pacimonense, Pseudotaxiphyllum distichaceum, Rhegmatodon polycarpa, Schistidium apocarpum, S. rivulare ssp. latifolium, Scorpidium scorpioides, Syrrhopodon steyermarkii, Tortula caroliniana, Zygodon ehrenbergii, Z. fragilis, Z. stenocarpus. Approximately 560 new departmental records are included. Several new combinations are made: Calyptrochaeta deflexa (C. Muell.) comb. nov., C. nutans (Hampe) comb. nov., Pleuridium subenervis (Hampe) comb. nov., Rhodobryum perspinidens (Broth.) comb. nov., R. roseodens (C. Muell.) comb. nov., Schizymenium brevicaulis (Hornsch.) comb. nov., S. dolichothecum (Herz.) comb. nov., S. pectinatum (C. Muell.) comb. nov., S. subobliquum (Hampe) comb. nov., Sematophyllum sticticola (C. Muell.) comb. nov. and, S. turgidulum (Herz.) comb. nov. Several further species are reduced to synonymy: Aulacomnium venezuelanum Mitt. (=A. palustre), Grimmia bogotense (Hampe) Jaeg. (=G. longirostris), Mielichhoferia elegans Herz. (=Schizymenium bogotense), Pohlia integridens (C. Muell.) Broth. (=P. elongata), and P. paucifolia (Jaeg.) Broth. (=P. elongata)

    Las briofitas del departamento de Nariño, Colombia : 1., musgos

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    A moss inventory for Departamento de Nariño, Colombia records 392 species distributed among 169 genera and 51 families. Taxa newly recorded for Colombia include: Daltonia jamesonii Taylor, Dicranella varia (Hedw.) Schimp., Isopterygium subbrevisetum (Hampe) Broth., Lepyrodontopsis trichophylla (Hedw.) Broth., Macromitrium trichophyllum Mitt., Philonotis incana (Taylor) H. Rob., Racomitrium lamprocarpum (Müll. Hal.) A. Jaeger, Rauiella lagoensis (Hampe) W. R. Buck, Sphagnum cuculliformes H. A. Crum, Stenodesmus tenuicuspis (Mitt.) A. Jaeger, Syrrhopodon isthmi W. D. Reese, Taxithelium pluripunctatum (Renauld & Cardot) W. R. Buck; Lepyrodontopsis and Stenodesmus represent genera new to the country

    Diets of Young King and Spanish Mackerel Off the Southeast United States

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    The diet of larval and post-larval (n = 95 and 307), and juvenile (n = 489 and 508) king (Scomberomorus cavalia) and Spanish mackerel (S. maculatus) from the Gulf of Mexico and southeastern Atlantic coastal waters of the U.S. consisted principally of fishes. Carangids, clupeids, and engraulids occurred in 23, 7 and 9% of larval and post-larval king mackerel stomachs and in 20, 40 and 7% of larval and post-larval Spanish mackerel stomachs, respectively. Sciaenids were also common in king mackerel, occurring in 21% of the stomachs. Prey fishes included the genera Cynoscion, Caranx, and Anchoa, and the species Opisthonema oglinum. Invertebrates, principally small crustaceans and nudibranch larvae, occurred infrequently in the diets of both species, but more so in Spanish mackerel than king mackerel. The dominant prey items for juvenile mackerels from the Atlantic were engraulids, clupeids, balistids, and squids, collectively accounting for 73.3% by volume of the diet of king mackerel and 88.8% of Spanish mackerel. More invertebrates occurred in the diet of juvenile Spanish mackerel than king mackerel, but they accounted for a smaller volume, i.e., 2.1% as compared to 5.4% for the Atlantic fish. Chi-square tests indicated significant differences between the diets of juvenile mackerel from the Gulf of Mexico and the Atlantic coast

    New Records of Native and Introduced Plants from Nebraska

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    Recent field work in Nebraska by staff of the University of Nebraska Herbarium has produced a number of records of previously uncollected specimens and has confirmed the presence of species collected only a few times long ago. Some of the records are of American species which are indigenous to Nebraska or which have recently spread to the state, while other records are of foreign species which are thoroughly established in the wild. Some of these are potentially serious weeds, though none have reached that stage yet. All specimens cited are deposited in the University Herbarium in Nebraska Hall, Lincoln, except that those marked with an asterisk are at the University of Nebraska at Omaha. Typha domingensis Pers. Typhaceae. Lancaster Co., Pawnee Lake, in extensive Typha marsh on west side, 18 September 1974, Kaul 2426. This extends the range north from Kansas. Potamogeton crispus L. Potamogetonaceae. Dodge Co., Fremont State Lakes, 22 June 1969, Sutherland 2383*. Morrill Co., Bridgeport State Lake, in shallow water along shore, 7 July 1974, Churchill 3848. Pawnee Co., Burchard Lake, submerged along inlet, 28 July 1973, Churchill 2039. Sherman Co., Beaver Creek State Wayside, shallow water, 31 May 1973, Churchill 777. This species is thoroughly established in the northeastern. states and in California, and it appears to be spreading rapidly in Nebraska man-made lakes. Vallisneria americana Michx. Hydrocharitaceae. Cherry Co., east end of Ballard\u27s Marsh, 9 July 1973, Churchill 1652. This is our second record for the state, the first being Kiener 27528, 21 Lake, Cherry Co., 27 August 1951. This submerged aquatic is abundant in eastern and northern states but in Nebraska, where it is at the western edge of its range, it is rare. It is an important duck food. Aegilops cylindrica Host. Poaceae. Douglas Co., Omaha, at 44th & Cass St., along tracks, 17 June 1971, Sutherland 2983. Lancaster Co., at 19th & Vine St. along tracks, Lincoln, 29 June 1972, Churchill 249. This plant was introduced from Europe and is becoming a bad weed in some states, though not in Nebraska

    Brymela antioquiana S.P. Churchill & J.J. Atwood (Pilotrichaceae) a new species from Colombia

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    A new species, Brymelaantioquiana S.P. Churchill & J.J. Atwood, is described and illustrated from Colombia. The new species is superficially similar to B. parkeriana (Hook. & Grev.) W.R. Buck - a species from northern Amazonia, the Guianas and Lesser Antilles - in its weakly complanate habit and straight, oblong-lanceolate leaves. Brymelaantioquiana differs from B. parkeriana inhaving: longer leaves (3.6-4.0 versus 2.1-3.2 mm); long-acuminate versus obtuse to acute leaf apices; more strongly undulate upper laminae; and entire to weakly serrulate leaf margins with simple teeth versus serrulate to moderately serrate leaf margins with occasionally bifid teeth. A key to the 13 species of Brymelais provided

    The Population of Weak Mg II Absorbers I. A Survey of 26 QSO HIRES/Keck Spectra

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    We present a search for "weak" MgII absorbers [those with W_r(2796) < 0.3 A in the HIRES/Keck spectra of 26 QSOs. We found 30, of which 23 are newly discovered. The spectra are 80% complete to W_r(2796) = 0.02 A and have a cumulative redshift path of ~17.2 for the redshift range 0.4 < z < 1.4. The number of absorbers per unit redshift, dN/dz, is seen to increase as the equivalent width threshold is decreased; we obtained dN/dz = 1.74+/-0.10 for our 0.02 <= W_r(2796) < 0.3 A sample. The equivalent width distribution follows a power law with slope -1.0; there is no turnover down to W_r(2796) = 0.02 A at = 0.9. Weak absorbers comprise at least 65% of the total MgII absorption population, which outnumbers Lyman limit systems (LLS) by a factor of 3.8+/-1.1; the majority of weak MgII absorbers must arise in sub-LLS environments. Tentatively, we predict that ~5% of the Lyman-alpha forest clouds with W_r(1215) > 0.1 A will have detectable MgII absorption to W_r,min(2796) = 0.02 A and that this is primarily a high-metallicity selection effect (Z/Z_sun] > -1). This implies that MgII absorbing structures figure prominently as tracers of sub-LLS environments where gas has been processed by stars. We compare the number density of W_r(2796) > 0.02 A absorbers with that of both high and low surface brightness galaxies and find a fiducial absorber size of 35h^-1 to 63h^-1 kpc, depending upon the assumed galaxy population and their absorption properties. The individual absorbing "clouds" have W_r(2796) <= 0.15 A and their narrow (often unresolved) line widths imply temperatures of ~25,000 K. We measured W_r(1548) from CIV in FOS/HST archival spectra and, based upon comparisons with FeII, found a range of ionization conditions (low, high, and multi-phase) in absorbers selected by weak MgII.Comment: Accepted Version: 43 pages, PostScript figures embedded; accepted to ApJ; updated version includes analysis of CIV absorptio

    Genome-wide transcript and protein analysis highlights the role of protein homeostasis in the aging mouse heart.

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    Investigation of the molecular mechanisms of aging in the human heart is challenging because of confounding factors, such as diet and medications, as well as limited access to tissues from healthy aging individuals. The laboratory mouse provides an ideal model to study aging in healthy individuals in a controlled environment. However, previous mouse studies have examined only a narrow range of the genetic variation that shapes individual differences during aging. Here, we analyze transcriptome and proteome data from 185 genetically diverse male and female mice at ages 6, 12, and 18 mo to characterize molecular changes that occur in the aging heart. Transcripts and proteins reveal activation of pathways related to exocytosis and cellular transport with age, whereas processes involved in protein folding decrease with age. Additional changes are apparent only in the protein data including reduced fatty acid oxidation and increased autophagy. For proteins that form complexes, we see a decline in correlation between their component subunits with age, suggesting age-related loss of stoichiometry. The most affected complexes are themselves involved in protein homeostasis, which potentially contributes to a cycle of progressive breakdown in protein quality control with age. Our findings highlight the important role of post-transcriptional regulation in aging. In addition, we identify genetic loci that modulate age-related changes in protein homeostasis, suggesting that genetic variation can alter the molecular aging process

    The Physical Conditions of Intermediate Redshift MgII Absorbing Clouds from Voigt Profile Analysis

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    [Slightly Abridged] We present a detailed statistical analysis of the column densities, N, and Doppler parameters, b, of MgII absorbing clouds at redshifts 0.4<z<1.2. We use the HIRES/Keck data and Voigt profile (VP) fitting results presented by Churchill & Vogt (Paper I). The sample is comprised of 175 clouds from 23 systems along 18 quasar lines of sight. In order to understand whether inferred conditions could be "false", we performed extensive simulations of our VP analyses. In brief, we find: (1) N(FeII) and N(MgII) are correlated at the 9-sigma level. There is a 5-sigma anti-correlation between N(MgI)/N(MgII) and N(MgII). (2) Power-law fits to the distributions of N(MgII), N(FeII), and N(MgI) yielded power-law slopes of -1.6, -1.7, and -2.0. (3) The modes of the Doppler parameter distributions were ~5 km/s for MgII and FeII and ~7 km/s for MgI. The clouds are consistent with being thermally broadened, with temperatures in the 30-40,000K range. (4) A two-component Gaussian model to the velocity two-point correlation function yielded velocity dispersions of 54 km/s and 166 km/s. The narrow component has roughly twice the amplitude of the broader component. The width and amplitude of the broader component decreases as equivalent width increases. (5) From photoionization models we find that the column density ratios are most consistent with photoionization by the extragalactic background, as opposed to stars. Based upon N(MgI)/N(MgII), it appears that at least two-phase ionization models are required to explain the data.Comment: Accepted to the Astronomical Journal (January 2003

    The Spatial, Ionization, and Kinematic Conditions of the z=1.39 Damped Ly-alpha Absorber in Q0957+561 A,B

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    We examined the sizes of the absorption clouds in a z=1.3911 damped Ly-alpha absorber (DLA) in the double image lensed quasar Q0957+561 A,B (separation 135 pc at the absorber redshift). Using HIRES/Keck spectra, we studied the MgII 2796,2803 doublet, FeII multiplet, and MgI 2853 transition in absorption. We defined six "clouds" in the system of sightline A and seven clouds in the system of sightline B. An examination of the N(v) profiles, using the apparent optical depth method, reveals no clear physical connection between the clouds in A and those in B. The observed column density ratios of all clouds is log[N(MgI)/N(FeII)] ~ -2 across the full velocity range in both systems and also spatially (in both sightlines). This is a remarkable uniformity not seen in Lyman limit systems. The uniformity of the cloud properties suggests that the multiple clouds are not part of a "halo". Based upon photoionization modeling, we constrain the ionization parameters in the range -6.2 < log(U) < -5.1, where the range brackets known abundance ratio and dust depletion patterns. The inferred cloud properties are densities of 2 < n_H < 20 cm^-3, and line of sight sizes of 1 < D < 25 pc. The masses of the clouds in system A are 10 < M/M_sun < 1000 and in system B are 1 < M/M_sun < 60 for spherical clouds. For planar clouds, the upper limits are 400 M_sun and 160 M_sun for A and B, respectively. We favor a model of the absorber in which the DLA region itself is a single cloud in thiscomplex, which could be a parcel of gas in a galactic ISM. A spherical cloud of ~10 pc would be limited to one of the sightlines (A) and imply a covering factor less than 0.1 for the DLA complex. We infer that the DLA cloud properties are consistent with those of lower density, cold clouds in the Galactic interstellar medium.Comment: Accepted for publication in the Astrophysical Journal; final versio
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