1,442 research outputs found
La conexión discursiva en textos escritos descriptivos
En este trabajo se estudia, a partir de un corpus de 383 textos, la función de los conectores discursivos en la construcción de escritos redactados sobre la base de una secuencia dominante de naturaleza descriptiva. En primer lugar, se valora cómo afecta al uso de los enlaces la naturaleza conceptual de la descripción según se fije esta en seres humanos o en espacios físicos tales como viviendas. A continuación, se centra en la función de los enlaces temporales y los ordenadores discursivos en la confi guración de perspectivas dinámicas de descripción. En tercer término, se evalúa el uso de los relacionantes locativos como enlaces textuales que establecen un tipo de relación entre un objeto base y un objeto figura ubicados en unidades textuales distintas. Por último, se clasifican los conectores espaciales identificados sobre siete ejes básicos de organización y se analiza la coaparición de enlaces correspondientes a ejes distintos.This study analyzes a corpus of 383 texts in order to study the function of discourse connectors in the creation of written texts with a fundamentally descriptive structure. Firstly, this study assesses the extent to which the conceptual nature of description affects the use of discourse connectors depending on whether it deals with humans or with physical spaces such as houses. Next, the study focuses on the function of discourse and temporal connectors in the configuration of dynamic description perspectives. The third part of the study analyzes the use of locative connectors as linking elements which establish a relationship between a concrete object and a figurative one which are located in different text units. Finally, the spatial connectors found during the study are classified into seven basic organizational categories and the instances of connectors which appear in more than one category are analyzed
Catodoluminiscencia de carbonatos lacustres pérmicos de los Pirineos Occidentales: un modelo de cementación temprana en paleoacuíferos meteóricos asociados a lagos
Cathodoluminescence of Permian lacustrine carbonates from the Westem Pyrenees: a model for early cementation in meteoric aquifers associated with lakes. We present here a case-study of early diagenetic cementation in Permian lacustrine lithofacies (Aragón-Béarn and Basque Country Basins, western Pyrenees). Cathodoluminescence zoning in calcite cements shows a general non-luminescent-bright luminescent-dull luminescent sequence which we interpret as a result of the transition from the vadose and oxic phreatic environments to the progressively reducing phreatic ground waters. Vadose features and non-lumines-cent cements predominate in the more pedogenically altered andlor subaerially exposed facies. The very early timing of the whole sequence and the differences in cementation among lacustrine, palustrine and alluvial plain facies emphasize the dependence of the aquifers on sedimentary subenvironments and lake level changes. The Permian model here described is applicable to early cementation in meteoric aquifers related to shallow, carbonate lakes. Our data agree with the well-known control of Fe and Mn contents on the cathodolurninescence of calcites and dolomites and the uncertainties of a quantitative relationship between chernical composition and luminescence. The proposed sensitizer role for Mg needs further testing
Coordinated regulation of chromatophore differentiation and melanogenesis during the ontogeny of skin pigmentation of Solea senegalensis (Kaup, 1858)
Abnormal pigmentation of Senegalese sole has been described as one problem facing the full exploitation of its commercial production. To improve our understanding of flatfish pigmentation of this commercially important species we have evaluated eleven genes related to two different processes of pigmentation: melanophore differentiation, and melanin production. The temporal distribution of gene expression peaks corresponds well with changes in pigmentation patterns and the intensity of skin melanization. Several gene ratios were also examined to put in perspective possible genetic markers for the different stages of normal pigmentation development. Further, the phenotypic changes that occur during morphogenesis correspond well with the main transitions in gene expression that occur. Given the dramatic phenotypic alterations which flatfish undergo, including the asymmetric coloration that occurs between the ocular and the blind side, and the synchrony of the two processes of morphogenesis and pigmentation ontogenesis, these species constitute an interesting model for the study of pigmentation. In this study we present a first approximation towards explaining the genetic mechanisms for regulating pigmentation ontogeny in Senegalese sole, Solea senegalensis.Ministry of Science and Innovation (MICIIN) of the Spanish Government [AGL2008-03897-C04-01/ACU]; European Community [FP7/2007-2013-222719-LIFECYCLE]; Spanish Governmentinfo:eu-repo/semantics/publishedVersio
Geodemography: Land cover, geographical information systems and population distribution
This paper examines the recent application of the Geographical Information Systems (GIS) to the analysis of population distribution. We mention the efforts of the National Statistical Institutes in this direction boosted by the last census 2011.The stating point is a growing need to have available population figures for areas not related to administrative boundaries, either user defined zones or in grid format.This allows a convenient zonal system to combine demographic characteristics with environmental and pure geographic data, so the relation between the man and the environment can be analyzed in a unified way.Eventually, we offer a practical illustration of the interactions between GIS techniques and administrative population data in the study of spatial population distribution: We build a density grid for Spain by dasymetric methods from census tracts population data and Land Cover and Use Information System of Spain (SIOSE).The analysis is done within the spatial reference framework of the European Union
Síndrome uña-rótula
Presentamos el estudio de 3 casos afectos de un síndrome "uña-rótula",
con historia familiar positiva en uno de ellos. Este síndrome es un transtorno hereditario
de transmisión autosómica dominante, caracterizado por displasia ungueal y de articulacione
s y formación de una s excrecencia s óseas características a nive l del ilíaco
(cuernos ilíacos). El síndrome completo se define por los cambios esqueléticos asociados
a una nefropatía. Describimos las anomalías clínico-radiográficas de tres paciente s
y realizamos una revisión de la literatura sobre esta displasia poco frecuente.The author s showed thre e patients affected by "nail patella" syndrome
with positive familiar history in one case. The "nail patella" syndrome is an autosomal
dominant condition, characterized by nail and joint dysplasia and extra bone formation
at the os ilium. The complet e syndrome is characterized by a serie s of skeletal disorders
and specific nephropathy. This article reports the clinical and roentgenographi c
findings of three patients and the results of the study of their families. A review of the
literature is done
Pumping seawater from coastal aquifers for supplying desalination plants
The lack of water in the coastal areas demands an onerous search for an appropriate solution. One solution is that of water transfer from areas of surplus, but this is itself problematical. Technological developments have introduced the possibility of utilizing desalinated seawater as a drinking water source at a competitive price. Abstraction from coastal aquifers that are connected to the sea appears to be the cheapest means of supply. However, pumping poses some problems due to the corrosiveness of seawater. These problems include the difficulties of choosing suitable sites for the abstractions, drilling method, casing, filter pack, as well as the design of a monitoring system to assess aquifer behaviour as a result of the generally high exploitation rate. The 31 boreholes that have been drilled in the Andarax Delta near the city of Almeria are cited as an example of a real application
Projection-Based Local and Global Lipschitz Moduli of the Optimal Value in Linear Programming
In this paper, we use a geometrical approach to sharpen a lower bound given in [5] for the Lipschitz modulus of the optimal value of (finite) linear programs under tilt perturbations of the objective function. The key geometrical idea comes from orthogonally projecting general balls on linear subspaces. Our new lower bound provides a computable expression for the exact modulus (as far as it only depends on the nominal data) in two important cases: when the feasible set has extreme points and when we deal with the Euclidean norm. In these two cases, we are able to compute or estimate the global Lipschitz modulus of the optimal value function in different perturbations frameworks
Dynamical measurements of deviations from Newton's law
In a previous work (arXiv:1609.05654v2), an experimental setup aiming at the
measurement of deviations from the Newtonian distance dependence of
gravitational interactions was proposed. The theoretical idea behind this setup
was to study the trajectories of a "Satellite" with a mass around a "Planet" with mass , looking for precession of the orbit. The
observation of such feature induced by gravitational interactions would be an
unambiguous indication of a gravitational potential with terms different from
and, thus, a powerful tool to detect deviations from Newton's
law. In this paper we optimize the proposed setup in order to achieve maximal
sensitivity to look for {\em Beyond-Newtonian} corrections. We study in detail
possible background sources that could induce precession and quantify their
impact on the achievable sensitivity. We conclude that a dynamical measurement
of deviations from newtonianity can test Yukawa-like corrections to the
potential with strength as low as for distances as small
as .Comment: Two-column format (26 pages), 18 figure
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