8,977 research outputs found

    On the type species of Aubignyna and a description of A. hamblensis, a new microforaminifer from temperate shallow waters

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    The genus Aubignyna Margerel, 1970 (type A. mariei) was originally described from the upper Pliocene of NW France. Examination and re-illustration of topotypes of A. mariei Margerel, 1970, the holotype of Buccella planidorso Atkinson, 1969 (from the Recent of Cardigan Bay, Wales) and syntypes of Rotalia perlucida Heron-Allen and Earland, 1913 (from the Clare Island Survey, western Ireland) shows them to be conspecific. Consequently, the type-species of Aubignyna becomes R. perlucida, for which a lectotype is chosen. A new species of microforaminifera formally described here is assigned to Aubignyna and shown to occur in a wide range of intertidal - shallow subtidal, brackish - normal marine estuaries and lagoons in Europe and North America

    An empirical calibration to estimate cool dwarf fundamental parameters from H-band spectra

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    Interferometric radius measurements provide a direct probe of the fundamental parameters of M dwarfs, but is within reach for only a limited sample of nearby, bright stars. We use interferometrically-measured radii, bolometric luminosities, and effective temperatures to develop new empirical calibrations based on low-resolution, near-infrared spectra. We use H-band Mg and Al features to derive calibrations for effective temperature, radius and log luminosity; the standard deviations in the residuals of our best fits are, respectively, 73K, 0.027Rsun, and 0.049 dex (11% error on luminosity). These relationships are valid for mid K to mid M dwarf stars, roughly corresponding to temperatures between 3100 and 4800K. We apply our calibrations to M dwarfs targeted by the MEarth transiting planet survey and to the cool Kepler Objects of Interest (KOIs). We independently validate our calibrations by demonstrating a clear relationship between our inferred parameters and the absolute K magnitudes of the MEarth stars, and we identify objects with magnitudes too bright for their estimated luminosities as candidate multiple systems. We also use our inferred luminosities to address the applicability of near-infrared metallicity calibrations to mid and late M dwarfs. The temperatures we infer for the KOIs agree remarkably well with those from the literature; however, our stellar radii are systematically larger than those presented in previous works that derive radii from model isochrones. This results in a mean planet radius that is 15% larger than one would infer using the stellar properties from recent catalogs. Our results confirm those of previous in-depth studies of Kepler-42, Kepler-45, and Kepler-186.Comment: Accepted to ApJ. Tables 4 and 5, and machine readable versions of Tables 5 and 7 are available in the ApJ journal articl

    Allelic variation in HLA-B and HLA-C sequences and the evolution of the HLA-B alleles

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    Several new HLA-B (B8, B51, Bw62)- and HLA-C (Cw6, Cw7)-specific genes were isolated either as genomic cosmid or cDNA clones to study the diversity of HLA antigens. The allele specificities were identified by sequence analysis in comparison with published HLAB and -C sequences, by transfection experiments, and Southern and northern blot analysis using oligonucleotide probes. Comparison of the classical HLA-A, -B, and -C sequences reveals that allele-specific substitutions seem to be rare events. HLA-B51 codes only for one allelespecific residue: arginine at position 81 located on the cd helix, pointing toward the antigen binding site. HLA-B8 contains an acidic substitution in amino acid position 9 on the first central/3 sheet which might affect antigen binding capacity, perhaps in combination with the rare replacement at position 67 (F) on the Alpha-l helix. HLA-B8 shows greatest homology to HLA-Bw42, -Bw41, -B7, and -Bw60 antigens, all of which lack the conserved restriction sites Pst I at position 180 and Sac I at position 131. Both sites associated with amino acid replacements seem to be genetic markers of an evolutionary split of the HLA-B alleles, which is also observed in the leader sequences. HLA-Cw7 shows 98% sequence identity to the JY328 gene. In general, the HLA-C alleles display lower levels of variability in the highly polymorphic regions of the Alpha 1 and Alpha 2 domains, and have more distinct patterns of locusspecific residues in the transmembrane and cytoplasmic domains. Thus we propose a more recent origin for the HLA-C locus

    The origins of radial fracture systems and associated large lava flows on Venus

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    Magellan images have revealed the existence of systems of radial fractures on venus that are very similar in form to terrestrial dike swarms such as the Mackenzie swarm in Northern Canada. The association of many of the fracture systems with lava flows, calderas, and volcanic edifices further support the idea of a dike emplacement origin. A global survey of the Magellan images has allowed the location of 300 such fracture systems. Two types of fracture systems are defined. A series of models were developed to simulate the emplacement of dikes on Venus. Observations of fracture lengths and widths were then used to constrain the emplacement conditions. The model results show that the great length and relatively large width of the fractures can only be explained if the dikes that produce them were emplaced in high driving pressure (pressure buffered) conditions. Such conditions imply high rates of melt production, which is consistent with the melt being derived directly from a plume head. We have recently modeled the vertical emplacement of a dike from the top of a mantle plume and calculated the eruption rates such a dike would produce on reaching the surface. This modeling shows that eruption rates of approximately 0.1 cu km/hr can readily be generated by such a dike, consistent with the above results. However, the sensitivity of the model to dike width and therefore driving pressure means that eruption rates from dikes emplaced from the base of the crust or the head of a mantle plume could be orders of magnitude higher than this. Clearly, therefore, the model needs to be refined in order to better constrain eruption conditions. However, it is worth noting here that the initial results do show that even for moderate dike widths, eruption rates could be at least on the order of those estimated for terrestrial flood basalts

    CLONING OF THE 1.4-kb mRNA SPECIES OF HUMAN COMPLEMENT FACTOR H REVEALS A NOVEL MEMBER OF THE SHORT CONSENSUS REPEAT FAMILY RELATED TO THE CARBOXY TERMINAL OF THE CLASSICAL 150-kDa MOLECULE

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    Three factor H mRNA species of 4.3 kb, 1.8 kb, and 1.4 kb are constitutively expressed in human liver. Having previously characterized full-length cDNA clones derived from the 4.3-kb and 1.8-kb factor mRNA, we report here the isolation and eucaryotic expression of full-length cDNA clones coding for the 1.4-kbm RNA species. The 1266-bp cDNA codes for a polypeptide of 330 amino acids and contains two polyadenylation signals and a short poly(A)+tailT. he protein is composed of a leader peptide followed by five short consensus repeat domains. It shows a hybrid structure with the last three domains being almost identical to the carboxy- terminal of thcel assical 1 BO-kDa factor H molecule and the two first domains representing unique short consensus repeat structures. Eucaryotic expression in COS7 cells revealed two polypeptides derived from one cDNA clone that area lso found in human serum. Differences between the cDcNloAn es within the last three domains indicate two distinct, possibly allelic sequences that, in addition, differ from the authentic 150-kDa factor H sequence. Southern blot results support the notion that the 4.3-kb factor H and the 1.4-kb factor H-related mRNA are transcribed from two separate but highly homologous genes. Factor H, a glycoprotein of 150,00

    Serving Two Masters: Moravian Brethren in Germany and North Carolina, 1727-1801

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    The eighteenth century was a time of significant change in the perception of marriage and family relations, the emphasis of reason over revelation, and the spread of political consciousness. The Unity of the Brethren, known in America as Moravians, experienced the resulting tensions firsthand as they organized their protective religious settlements in Germany. A group of the Brethren who later settled in Salem, North Carolina, experienced the stresses of cultural and generational conflict when its younger members came to think of themselves as Americans. The Moravians who first immigrated to America actively maintained their connections to those who remained in Europe and gave them the authority for deciding religious, social, and governmental issues. But, as the children born in Salem became acclimated to more freedoms, particularly in the wake of the American Revolution, a series of disputes intensified the problems of transatlantic governance. While the group\u27s leadership usually associated Enlightenment principles with rebellion and religious skepticism, the younger Brethren were drawn to its message of individual autonomy and creative expression. Elisabeth Sommer traces the impact of this generational and cultural change among Moravians on both sides of the Atlantic and examines the resulting debate over the definition of freedom and faith. An important contribution to an expanding literature whose base in archival work on both sides of the Atlantic reveals the Moravian struggles to be faithful to their deepest commitments. —A.G. Roeber, Pennsylvania State University The international Moravian story is charming and powerful. . . . We are indebted to Sommer for arduous and skillful work in passing on their story to us. —American Historical Review Provides a more profound understanding of what the Moravians believed, why they came, and the process by which they increasingly accommodated to the American world. —Appalachian Quarterly A detailed and thought-provoking narrative of declension and the formation of new political identities. —Georgia Historical Quarterly Creative and well-researched. . . . Will interest a variety of scholars. —H-Net Reviews A good book that tells us much about the development of American sensibilities in an immigrant religious group and does so with a helpful transatlantic perspective. —Journal of American History Contributes significantly to our understanding of the evolution of Moravian communities and of the forces that influenced their future direction. —Journal of Southern History Gives additional depth to our comparative understanding of the social as well as the religious experience of people on two sides of the Atlantic in the eighteenth century. —Journal of the Early Republic Should prove beneficial not only to those primarily interested in Moravian studies but also to those whose field includes wider social history concerns. —North Carolina Historical Review A valuable contribution not only to the field of early American religious history, but also to the sociology of religion and Moravian and Pietist studies. —Religious Studies Review Represents the best trends in transatlantic history. . . . Invites us to search for other religious cables binding early America to a wider world. —William and Mary Quarterlyhttps://uknowledge.uky.edu/upk_history_of_religion/1004/thumbnail.jp

    A Comparison of Vertical Ground Reaction Forces in Single-leg Jump Take-offs and Double-leg Jump Take-offs in Indoor Collegiate Volleyball Players

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    The purpose of this study was to determine if differences in vertical ground reaction forces (vGRFs) exist between single-leg take-off approaches (SL) and double-leg take-off approaches (DL) and if sex or positional differences existed in vGRFs in SL- or DL-style approaches. It was hypothesized that DL jumps would generate greater vGRFs, males would generate greater vGRFs in both styles, and middle blockers would have higher SL vGRFs while pin hitters would have higher DL vGRFs. Nine collegiate volleyball players (4 female; 5 male) (age: 20.44 ± 1.42 years; height: 186.02 ± 6.44 cm; body mass: 78.21 ± 10.63kg; body fat: 11.66 ±5.62%) were tested. An AMTI force plate collected vGRFs with three recorded trials per approach style per subject with randomization of jump-style order. The level of significance was set at p\u3c 0.05. No significant differences were found between vGRFs and position or SL and DL vGRFs. Males had significantly higher vGRFs overall compared to females (p=0.007). Male SL vGRFs were significantly larger than females (p=0.017). DL, relative SL, and relative DL vGRFs were not significantly different between genders. Height, mass, and body fat percentage had at least moderate correlations to combined vGRFs, and height moderately correlated to DL vGRFs. These results suggest that both takeoffs have similar enough force load to be interchangeable. Strength coaches may use both styles to train their athletes and improve neural integration. Positional jump loads during practice or games may be tracked interchangeably in style regarding the take-off phase
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