1,721,078 research outputs found
Drainage anomalies as indicators of soft-linked deformation zones between neotectonic structural highs in the Precordillera, Central Andes of Argentina
Full text linkBetween 31°45'-32°15' S, the western piedmont of the Ansilta block in the Precordillera of Argentina has been uplifted in Quaternary times through folds, blind faults and faulted blocks that form discrete and evident areas of neotectonic deformation (structural highs). In between, subtle tectonic perturbations of the fluvial landforms (drainage anomalies), such as diverted and entrenched streams, asymmetric basins, incision anomalies, convex-upward longitudinal stream profiles, dammed rivers and broom-shaped patterns allow the recognition of areas of incipient deformation. We combined the analyses of both the structural highs and the drainage anomalies areas to investigate the role of the latest as an expression of soft-linkage areas in fault systems. The structural highs would be interpreted as isolated features without the consideration of the drainage anomalies areas between them. Moreover, linking the structural highs using the drainage anomalies reveals the extent of major Quaternary deformation belts in their initial development stages.Fil: Terrizzano, Carla Marina. Swiss Federal Institute of Technology Zurich; Suiza. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Geociencias Básicas, Aplicadas y Ambientales de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Geociencias Básicas, Aplicadas y Ambientales de Buenos Aires; ArgentinaFil: Cortes, Jose Maria. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Geociencias Básicas, Aplicadas y Ambientales de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Geociencias Básicas, Aplicadas y Ambientales de Buenos Aires; ArgentinaFil: Zech, Roland. Swiss Federal Institute of Technology Zurich; SuizaFil: Garcia Morabito, Ezequiel. Swiss Federal Institute of Technology Zurich; Suiza. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Estudios Andinos "Don Pablo Groeber". Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Estudios Andinos "Don Pablo Groeber"; Argentin
Surface exposure dating of moraines in Bolivia: unrecognized uncertainties and paleoclimatic implications
No full text
A 16-ka delta O-18 record of lacustrine sugar biomarkers from the High Himalaya reflects Indian Summer Monsoon variability
No full textWe investigated a late glacial-Holocene lacustrine sediment archive located at 4,050 m a.s.l. in the small carbonate-free catchment of Lake Panch Pokhari, Helambu Himal, Nepal. A delta O-18 sugar biomarker record was established by applying novel compound-specific delta O-18 analysis of plant sugar biomarkers (Zech and Glaser in Rapid Commun Mass Spectrom 23:3522-3532, 2009). This method overcomes analytical challenges such as extraction and purification faced by previous methods aimed at using delta O-18 of aquatic cellulose as a paleoclimate proxy. The delta O-18 results for sugar biomarkers arabinose, xylose and fucose agree well and reveal a pronounced trend towards lower delta O-18 values during the deglaciation and the onset of the Bolling/Allerod interstadial. By contrast, the period of the Younger Dryas is characterized by higher delta O-18 values. The early Holocene again reveals lower delta O-18 values. We suggest that our lacustrine delta O-18 record reflects coupled hydrological and thermal control. It is strongly related to changes in the oxygen isotopic composition of paleo-precipitation and resembles the delta O-18 records of Asian speleothems. With respect to the 'amount effect,' the record is interpreted as reflecting the Indian Summer Monsoon intensity. The precipitation signal is, however, amplified in our record by evaporative O-18 enrichment that is controlled by the ratio of precipitation to evaporation. We suggest that our delta O-18 record reflects the variability of the Indian Summer Monsoon, which was strong during the Bolling/Allerod interstadial and early Holocene, but weak during the Younger Dryas stadial. This interpretation is corroborated by a pollen-based index for Lake Panch Pokhari that estimated the strength of the Indian Summer Monsoon versus the strength of the Westerlies. Millennial-scale synchronicity with the Greenland delta O-18 temperature records highlights the previously suggested strong teleconnections between the Asian Monsoon system and North Atlantic climate variability
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Surface exposure dating on moraines in the Valle Rucachoroi (39°S, Argentina) and on Cerro Fredes Plateau (31°S, Chile)
No full text- …
