The geomorphology and morphometry of the banded terrain in Hellas basin, Mars

Hellas basin is a large impact basin situated in the southern highlands of Mars. The north-western part of the basin has the lowest elevation (-7.5 km) on the planet and contains a possibly unique terrain type, which we informally call “banded terrain”. The banded terrain is made up of smooth-looking banded deposits that display signs of viscous behavior and a paucity of superimposed impact craters. In this study, we use newly acquired high spatial resolution images from the High Resolution Imaging Science Experiment (HiRISE) in addition to existing datasets to characterize the geomorphology, the morphometry and the architecture of the banded terrain. The banded terrain is generally confined to the NW edge of the Alpheus Colles plateau. The individual bands are ~3–15 km-long, ~0.3 km-wide and are separated by narrow inter-band depressions, which are ~65 m-wide and ~10 m-deep. The bands display several morphologies that vary from linear to concentric forms. Morphometric analysis reveals that the slopes along a given linear or lobate band ranges from 0.5° to 15° (average~6°), whereas the concentric bands are located on flatter terrain (average slope~2–3°). Crater-size frequency analysis yields an Amazonian-Hesperian boundary crater retention age for the terrain (~3 Gyr), which together, with the presence of very few degraded craters, either implies a recent emplacement, resurfacing, or intense erosion. The apparent sensitivity to local topography and preference for concentrating in localized depressions is compatible with deformation as a viscous fluid. In addition, the bands display clear signs of degradation and slumping at their margins along with a suite of other features that include fractured mounds, polygonal cracks at variable size-scales, and knobby/hummocky textures. Together, these features suggest an ice-rich composition for at least the upper layers of the terrain, which is currently being heavily modified through loss of ice and intense weathering, possibly by wind.

The role of climate-driven chemical weathering on soil production

Climate plays an important role in controlling rates of weathering and weathered regolith production. Regolith production functions, however, seldom take climate parameters into account. Based on a climate-dependent weathered regolith production model, at low denudation rates, relative regolith thicknesses are less sensitive to changes in precipitation rates, while at high denudation rates, small changes in climatic parameters can result in complete stripping of hillslopes. This pattern is compounded by the long residence times and system response times associated with low denudation rates, and vice versa. As others have shown, the transition between regolith-mantled and bedrock slopes is dependent on the ratio of denudation to production. Here, we further suggest that this is itself a function of precipitation rate and temperature. We suggest that climatic parameters can be easily incorporated into existing soil production models and that such additions improve the predictive power of soil production models. (C) 2013 Elsevier B.V. All rights reserved.

Sulfate and Nitrate Assimilation in Leaves of Quercus ilex and Quercus pubescens Grown Near Natural CO2 Springs in Central Italy

The effect of long-term exposure to elevated pCO2 concentrations on sulfate and nitrate assimilation was studied under field conditions using leaves from Quercus ilex and Quercus pubescens trees growing with ambient or elevated CO2 concentrations in the vicinity of three natural CO2 springs, Bossoleto, Laiatico and Sulfatara, in Tuscany, Italy. The activity of the key enzymes of sulfate assimilation, adenosine 5′-phosphosulfate reductase (APR) and nitrate assimilation, nitrate reductase (NR), were measured together with the levels of acid soluble thiols, and soluble non-proteinogenic nitrogen compounds. Whereas NR activity remained unaffected in Q. ilex or increased Q. pubescence, APR activity decreased in the area of CO2 springs. The latter changes were often accompanied by increased GSH concentrations, apparently synthesized from H2S and SO2 present in the gas mixture emitted from the CO2 springs. Thus, the diminished APR activity in leaves of Q. ilex and Q. pubescence from spring areas can best be explained by the exposure to gaseous sulfur compounds. Although the concentrations of H2S and SO2 in the gas mixture emitted from the vents at the CO2 springs were low at the Bossoleto and Laiatico spring, these sulfur gases pose physiological effects, which may override consequences of elevated pCO2.

Accumulation rates and predominant atmospheric sources of natural and anthropogenic Hg and Pb on the Faroe Islands

A monolith representing 5420 14C yr of peat accumulation was collected from a blanket bog at Myrarnar, Faroe Islands. The maximum Hg concentration (498 ng/g at a depth of 4.5 cm) coincides with the maximum concentration of anthropogenic Pb (111 μg/g). Age dating of recent peat accumulation using 210Pb (CRS model) shows that the maxima in Hg and Pb concentrations occur at AD 1954 ± 2. These results, combined with the isotopic composition of Pb in that sample (206Pb/207Pb = 1.1720 ± 0.0017), suggest that coal burning was the dominant source of both elements. From the onset of peat accumulation (ca. 4286 BC) until AD 1385, the ratios Hg/Br and Hg/Se were constant (2.2 ± 0.5 × 10-4 and 8.5 ± 1.8 × 10-3, respectively). Since then, Hg/Br and Hg/Se values have increased, also reaching their maxima in AD 1954. The age date of the maximum concentrations of anthropogenic Hg and Pb in the Faroe Islands is consistent with a previous study of peat cores from Greenland and Denmark (dated using the atmospheric bomb pulse curve of 14C), which showed maximum concentrations in AD 1953. The average rate of atmospheric Hg accumulation from 1520 BC to AD 1385 was 1.27 ± 0.38 μg/m2/yr. The Br and Se concentrations and the background Hg/Br and Hg/Se ratios were used to calculate the average rate of natural Hg accumulation for the same period, 1.32 ± 0.36 μg/m2/yr and 1.34 ± 0.29 μg/m2/yr, respectively. These fluxes are similar to the preanthropogenic rates obtained using peat cores from Switzerland, southern Greenland, southern Ontario, Canada, and the northeastern United States. Episodic volcanic emissions and the continual supply of marine aerosols to the Faroe Islands, therefore, have not contributed significantly to the Hg inventory or the Hg accumulation rates, relative to these other areas. The maximum rate of Hg accumulation was 34 μg/m2/yr. The greatest fluxes of anthropogenic Hg accumulation calculated using Br and Se, respectively, were 26 and 31 μg/m2/yr. The rate of atmospheric Hg accumulation in 1998 (16 μg/m2/yr) is comparable to the values recently obtained by atmospheric transport modeling for Denmark, the Faroe Islands, and Greenland.

An ice-rich flow origin for the banded terrain in the Hellas basin, Mars

The interior of Hellas Basin displays a complex landscape and a variety of geomorphological domains. One of these domains, the enigmatic banded terrain covers much of the northwestern part of the basin. We use high-resolution (CTX and HiRISE) Digital Terrain Models to show that most of the complex viscous flowing behavior exhibited by the banded terrain is controlled by topography and flow-like interactions between neighboring banded terrain. Furthermore, the interior of the basin hosts several landforms suggestive of the presence of near-surface ice, which include polygonal patterns with elongated pits, scalloped depressions, isolated mounds and collapse structures. We suggest that thermal contraction cracking and sublimation of near-surface ice are responsible for the formation and the development of most of the ice-related landforms documented in Hellas. The relatively pristine form, lack of superposed craters, and strong association with the banded terrain, suggest an Amazonian (<3 Ga) age of formation for these landforms. Finally, relatively high surface pressures (above the triple point of water) expected in Hellas and summer-time temperatures often exceeding the melting point of water ice suggest that the basin may have recorded relatively “temperate” climatic conditions compared to other places on Mars. Therefore, the potentially ice-rich banded terrain may have deformed with lower viscosity and stresses compared to other locations on Mars, which may account for its unique morphology.

Complex geomorphologic assemblage of terrains in association with the banded terrain in Hellas basin, Mars

Hellas basin acts as a major sink for the southern highlands of Mars and is likely to have recorded several episodes of sedimentation and erosion. The north-western part of the basin displays a potentially unique Amazonian landscape domain in the deepest part of Hellas, called “banded terrain”, which is a deposit characterized by an alternation of narrow band shapes and inter-bands displaying a sinuous and relatively smooth surface texture suggesting a viscous flow origin. Here we use high-resolution (HiRISE and CTX) images to assess the geomorphological interaction of the banded terrain with the surrounding geomorphologic domains in the NW interior of Hellas to gain a better understanding of the geological evolution of the region as a whole. Our analysis reveals that the banded terrain is associated with six geomorphologic domains: a central plateau named Alpheus Colles, plain deposits (P1 and P2), reticulate (RT1 and RT2) and honeycomb terrains. Based on the analysis of the geomorphology of these domains and their cross-cutting relationships, we show that no widespread deposition post-dates the formation of the banded terrain, which implies that this domain is the youngest and latest deposit of the interior of Hellas. Therefore, the level of geologic activity in the NW Hellas during the Amazonian appears to have been relatively low and restricted to modification of the landscape through mechanical weathering, aeolian and periglacial processes. Thermophysical data and cross-cutting relationships support hypotheses of modification of the honeycomb terrain via vertical rise of diapirs such as ice diapirism, and the formation of the plain deposits through deposition and remobilization of an ice-rich mantle deposit. Finally, the observed gradual transition between honeycomb and banded terrain suggests that the banded terrain may have covered a larger area of the NW interior of Hellas in the past than previously thought. This has implications on the understanding of the evolution of the deepest part of Hellas.

Report of the Second European Zebrafish Principal Investigator Meeting in Karlsruhe, Germany, March 21-24, 2012.

The second European Zebrafish Principal Investigator (PI) Meeting was held in March, 2012, in Karlsruhe, Germany. It brought together PIs from all over Europe who work with fish models such as zebrafish and medaka to discuss their latest results, as well as to resolve strategic issues faced by this research community. Scientific discussion ranged from the development of new technologies for working with fish models to progress in various fields of research such as injury and repair, disease models, and cell polarity and dynamics. This meeting also marked the establishment of the European Zebrafish Resource Centre (EZRC) at Karlsruhe that in the future will serve as an important focus and community resource for zebrafish- and medaka-based research.

Na 1 Nachlass Max Horkheimer, 600 - Korrespondenzen u.a. mit Friedrich Pollock (p. VI 42, 211-386)

Briefwechsel zwischen Max Horkheimer, Frederick Pollock und Karl August und Olga Wittfogel; 2 Briefe zwischen Edith B. Bernett und Max Horkheimer, April 1940; 2 Briefe zwischen Max Horkheimer und Philip Vaudrin, Juli 1939; 3 Briefe an David H. Stevens von Max Horkheimer, 26.03.1938; 1 Brief von A. Radcliffe an Frederick Pollock, 18.11.1937; 3 Briefe an Max Horkheimer von der Columbia University Faculty of Political Science (New York), November 1937; 2 Briefe von der Columbia University Department of History (New York) an Max Horkheimer, November 1937; 1 Brief an Max Horkheimer von Sharon Beard, 27.11.1937; 1 Brief von Ruth Benedict an Max Horkheimer, 19.11.1937; 1 Brief an Max Horkheimer von Franz Boas, 19.11.1937; 1 Brief von R. E. Chaddock an Max Horkheimer, 21.11.1937; 1 Brief an Max Horkheimer von Ch'ao-ting Chi, 19.11.1937; 1 Brief von J. M. Clark an Max Horkheimer, 22.11.1937; 1 Brief an Dr. Wertheimer von Morris R. Cohen, 29.11.1937; 1 Brief von Alfred E. Cohn an Max Horkheimer, 26.11.1937; 1 Brief an Max Horkheimer von John J. Coss, 22.11.1937; 1 Brief von George S. Counts an Max Horkheimer, 24.11.1937; 1 Brief an Max Horkheimer von A. P. Evans, 22.11.1937; 3 Briefe von Gertrude Stewart an Max Horkheimer, 20. - 24.11.1937; 1 Brief an Max Horkheimer von L. C. Goodrich, 22.11.1937; 1 Brief von John W. Innes an Max Horkheimer, 20.11.1937; 1 Brief an Max Horkheimer von Philip C. Jessup, 24.11.1937; 1 Brief von John A. Krout an Max Horkheimer, 23.11.1937; 1 Brief an Max Horkheimer von Bruno Lasker, 20.11.1937; 1 Brief von Samuel McCune Lindsay an Max Horkheimer, 24.11.1937; 1 Brief an Max Horkheimer von K. N. Llewellyn, 26.11.1937; 1 Brief von R. S. Lynd an Max Horkheimer, [November 1937]; 1 Brief an Max Horkheimer von R. M. MacIver, 19.11.1937; 1 Brief von Julian W. Mack an Max Horkheimer, 24.11.1937; 1 Brief an Max Horkheimer von Arthur Maxmahon, 20.11.1937; 1 Brief von Jerome Michael an Max Horkheimer, 26.11.1937; 1 Brief an Max Horkheimer von Wesley C. Mitchell, 22.11.1937; 1 Brief von der Columbia University School of Business (New York) an Max Horkheimer, 22.11.1937; 2 Briefe zwischen Max Horkheimer und der John Simon Guggenheim Memorial Foundation (New York), November 1937; 2 Briefe von der Columbia University Department of Psychology (New York) an Max Horkheimer, November 1937; 1 Brief an Max Horkheimer von Goodwin Watson, 23.11.1937; 1 Brief von Otto Nathan an Max Horkheimer, 26.11.937; 1 Brief an Max Horkheimer von John K. Norton, 23.11.1937; 1 Brief von der Columbia University Department of Chinese (New York) an Max Horkheimer, 23.11.1937; 1 Brief an Max Horkheimer von Gerold Tanquary Robinson, 19.11.1937; 1 Brief von der Columbia University Department of Public Law and Government (New York) an Max Horkheimer, 22.11.1937; 1 Brief an Max Horkheimer von R. C. Sailer, 20.11.1937; 1 Brief von Herbert W. Schneider an Max Horkheimer, 22.11.1937; 1 Brief an Max Horkheimer von R. L. Schuyler, 20.11.1937; 1 Brief von Pauline Steorns an Max Horkheimer, 22.11.1937; 1 Brief an Max Horkheimer von Frank Tannenbaum, 19.11.1937; 1 Brief von Alfred Vagés an Max Horkheimer, 26.11.1937;

The assumptions and effects of conservative procedures in low -dose risk assessment for setting safety standards

Conservative procedures in low-dose risk assessment are used to set safety standards for known or suspected carcinogens. However, the assumptions upon which the methods are based and the effects of these methods are not well understood.^ To minimize the number of false-negatives and to reduce the cost of bioassays, animals are given very high doses of potential carcinogens. Results must then be extrapolated to much smaller doses to set safety standards for risks such as one per million. There are a number of competing methods that add a conservative safety factor into these calculations.^ A method of quantifying the conservatism of these methods was described and tested on eight procedures used in setting low-dose safety standards. The results using these procedures were compared by computer simulation and by the use of data from a large scale animal study.^ The method consisted of determining a "true safe dose" (tsd) according to an assumed underlying model. If one assumed that Y = the probability of cancer = P(d), a known mathematical function of the dose, then by setting Y to some predetermined acceptable risk, one can solve for d, the model's "true safe dose".^ Simulations were generated, assuming a binomial distribution, for an artificial bioassay. The eight procedures were then used to determine a "virtual safe dose" (vsd) that estimates the tsd, assuming a risk of one per million. A ratio R = ((tsd-vsd)/vsd) was calculated for each "experiment" (simulation). The mean R of 500 simulations and the probability R $<$ 0 was used to measure the over and under conservatism of each procedure.^ The eight procedures included Weil's method, Hoel's method, the Mantel-Byran method, the improved Mantel-Byran, Gross's method, fitting a one-hit model, Crump's procedure, and applying Rai and Van Ryzin's method to a Weibull model.^ None of the procedures performed uniformly well for all types of dose-response curves. When the data were linear, the one-hit model, Hoel's method, or the Gross-Mantel method worked reasonably well. However, when the data were non-linear, these same methods were overly conservative. Crump's procedure and the Weibull model performed better in these situations. ^

Enfoque cambiario de la competitividad internacional de la vitivinicultura argentina entre 2000 y 2012

La vitivinicultura argentina se enfrenta a una situación externa dura por primera vez en más de una década, poniéndose en riesgo numerosas fuentes de trabajo y el porvenir de una industria que logró destacarse y hacerse un lugar en un mercado mundial extremadamente competitivo y donde el país no tenía presencia previa. Por otro lado, la apreciación real del peso argentino es señalada como la principal razón de esta crisis que vive el sector. Es necesario saber en profundidad la dinámica del cambio y la interacción de la Argentina tanto con compradores como con competidores para lograr hacer una evaluación certera de la situación actual y una proyección a futuro. Por lo dicho anteriormente, se pretende realizar un trabajo de naturaleza descriptiva y analítica, basado en las estadísticas disponibles en el país y en el mundo sobre la situación de las exportaciones vitivinícolas argentinas entre 2000 y 2012 a partir de un enfoque cambiario.

Complejo Santa Clara del Atuel

La finalidad de este trabajo de investigación es elaborar un plan de Marketing para el complejo Santa Clara del Atuel, ubicado en el Valle Grande, San Rafael, perteneciente a la Orden Franciscana. El objetivo principal es proporcionar un estudio de mercado, que defina en mejor medida la situación de la organización y sus estrategias de marketing, preparar a modo general, una buena fuente de datos a la cual se pueda recurrir. Existe también la intención de abarcar el estudio para la nueva residencia de habitaciones que se está desarrollando, brindando a la organización las herramientas necesarias con las cual empezar a trabajar. El análisis FODA generó una serie de estrategias de acción para llevar a cabo, que proponen distintos cursos de acción con la intención de maximizar las oportunidades y las fortalezas con la que se cuentan, fomentando el uso del internet como medio principal del contacto con el cliente, e incursionando en nuevos mercados como el chileno o el de la tercera edad; minimizar las amenazas y debilidades, a través de una adecuada estructuración de la organización, y la incorporación de las redes sociales al sistema de comunicación. Se proponen dos herramientas sumamente eficaces para dotar a Santa Clara de un sistema de planificación y control, estas son el círculo de calidad de Deming (o mejora continua) y el cuadro de mando integral, de Kaplan y Norton. La implementación de estos métodos dotará a la organización de un importante sistema de indicadores, objetivos, estrategias, planes de acción, etc., logrando así una comunicación en toda la empresa y un feedback estratégico con los empleados; la calidad plena en el servicio y la satisfacción de los clientes, tanto interno como externos; y el cumplimiento de los objetivos estratégicos y la misión de la organización.

El nudo coronado : Estudio de Cuatro cuartetos

Tabla de contenidos: Burnt Norton. East Coker. The Dry Salvages. Little Gidding.