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J Neurol Neurosurg Psychiatry 2004;75:560-566. doi: 10.1136/jnnp.2003.015107 Objectives: Although stroke associated with small vessel disease (SSVD) can induce both motor and cognitive impairment, the latter has received less attention. We [...]

The dynamic behavior of polymerization in liquid crystal polymer films is examined.

The Late Ordovician Pingliang Formation accumulated along the southern margin of the Ordos Basin in China. The convergence of the Yangtze Plate and Sino-Korean Plate led to a trench--arc--basin system during the Middle Ordovician, with a platform- and slope-dominated setting in the east where a graben complicated the overall simple paleogeographical picture, relatively parallel zones of a platform and a slope setting in the middle, and a change from platform to slope to deep marine to a trench setting in the west. This configuration resulted in various types of gravity flow deposits and contourites with different compositions and pathways. The present study focuses on the typical characteristics of contourites in the geological record and the relationships between contour currents and gravity flows. The Pingliang Formation contains eleven lithofacies grouped into five facies associations. These facies associations represent deep sea autochthonous deposits, several types of debrites, turbidites, and contourites, as well as turbidites within which the fine-grained top portion was reworked by a contour current. The various lithofacies are concentrated in different parts of the study area: micritic contourites and debrites are concentrated in the eastern part; debrites, and sandstone and siltstone turbidites are concentrated in the middle part; and calcarenitic turbidites, contourites, and reworked turbidites occur in the western part. The main contour current ran parallel to the contour lines from east to west. Although most of the contour current continually moved westward in the eastern part of the study area, a minor part split off and followed a semicircular pathway through the Fuping Graben; its velocity became reduced here so that micritic contourites were deposited. The velocity of the contour current was increased locally when it entered a confined trough in the western part of the study area. The relatively high energy of the contour current here resulted in calcarenitic contourites. The velocity of the contour current was low where it ran through an open environment, resulting in fine-grained, thin contourites in the middle part of the study area. Large turbidity currents and debris flows occurred here, and their high energy destroyed almost all earlier deposited contourites. This explains why traces of contour currents in the middle part of the study are very scarce, although the east--west-running contour current must have passed through this area. Key words: contourites, gravity flow deposits, Ordos Basin, Ordovician, Pingliang Formation. La Formation de Pingliang d'âge ordovicien tardif s'est accumulée le long de la bordure sud du bassin d'Ordos, en Chine. La convergence de la plaque du Yangtze et de la plaque sino-coréenne a produit un système de fosse--arc--bassin durant l'Ordovicien moyen, avec un milieu à dominance de plateforme et talus à l'est, où un graben a compliqué le portrait paléogéographique généralement simple, des zones assez parallèles d'un milieu de plateforme et talus dans sa partie médiane et une transition de milieu de plateforme à des milieux de talus, de bassin marin profond, puis de fosse à l'ouest. Cette configuration a donné divers types de dépôts d'écoulement gravitaire et de contourites de compositions et de voies de transport variées. L'étude s'intéresse aux caractéristiques typiques des contourites dans le registre géologique et aux relations entre des courants de contour et les écoulements gravitaires. La Formation de Pingliang contient onze lithofaciès regroupés en cinq associations de faciès. Ces associations représentent des dépôts autochtones marins d'eau profonde, plusieurs types de débrites, turbidites et contourites, ainsi que des turbidites dans lesquelles la partie supérieure à grains fins a été remaniée par un courant de contour. Ces différents lithofaciès sont concentrés dans différentes parties de la région à l'étude; des contourites et débrites micritiques sont concentrées dans la partie est, des débrites et des turbidites de grès et de siltstone sont concentrées dans la partie centrale et des turbidites calcarénitique, des contourites et des turbidites remaniées se trouvent dans la partie ouest. Le courant de contour principal s'écoulait parallèlement aux courbes de niveau, d'est en ouest. Si la majeure partie du courant de contour se déplaçait continuellement vers l'ouest dans la partie est de la région à l'étude, une petite partie s'en détachait pour suivre une voie semicirculaire à travers le graben de Fuping, où sa vitesse diminuait, menant au dépôt de contourites micritiques. La vitesse du courant de contour augmentait localement là où il passait par une fosse confinée dans la partie ouest de la région à l'étude. Le caractère relativement énergique du courant de contour à cet endroit a produit des contourites calcarénitiques. La vitesse du courant de contour était faible là où il passait par un milieu ouvert, produisant de minces contourites à grains fins dans la partie médiane de la région à l'étude. De grands courants de turbidité et coulées de débris s'y sont aussi produits, et leur caractère hautement dynamique a entraîné la destruction de presque toutes les contourites déposées antérieurement. Cela explique la rareté de traces de courant de contour dans la partie centrale de la région à l'étude, malgré le fait qu'un courant de contour d'écoulement est--ouest doit être passé par ce secteur. [Traduit par la Rédaction] Mots-clés : contourites, dépôts d'écoulement gravitaire, bassin d'Ordos, Ordovicien, Formation de Pingliang., Introduction A variety of complex hydrodynamic agents can act in deep marine environments, including gravity flows, contour currents, and internal waves (Hernandez-Molina et al. 2014; Mulder et al. 2012). Contour [...]

The creep behavior of a high density polyethylene (HDPE), currently used as raw material for pipe manufacture, was evaluated before and after exposure to oil derivates using transient rheometry. The creep behavior of the original HDPE was satisfactorily described using a generalized Kelvin-Voigt model based on two retardation times. The values of these critical times were quite different from each other, indicating a large distribution of macromolecular weight. The aging procedure was performed by immersing the polymer in two model fluids chosen to discriminate and understand the action of aromatic and paraffinic fractions of fuel derivatives (white oil, gas-oil). The batch operation was also carried out at two different temperatures to investigate the thermal activation of plausible degrading mechanisms. In the case of the aging performed in the paraffinic fluid, the polymer compliance continuously increased with the immersion duration. This behavior was attributed to a plasticization induced by the diffusion of the liquid in the polymer matrix. The same phenomenon was observed in the early stage of the HDPE aging carried out with the aromatic fluid. However, for longer aging times, the extraction of low molecular weight species produced the stiffening of the thermoplastic. POLYM. ENG. SCI., 50:2122-2130, 2010. [C] 2010 Society of Plastics Engineers, INTRODUCTION Carbon steel is the main material used to manufacture pipelines used for transportation of gas, oil and its derivatives. However, this material has at least two main drawbacks, namely: [...]

PTEN is a tumor suppressor gene mutated in many human cancers. We generated a bronchioalveolar epithelium-specific null mutation of Pten in mice [SP-C-rtTA/[(tetO).sub.7]-Cre/[Pten.sup.flox/flox] [(SOPten.sup.flox/flox) mice that was under the control [...]

Since 2000, the soybean aphid (Aphis glycines Matsumura) has become a major pest of soybean [Glycine max (L.) Merr.] in North America. In the USA, there are currently no commercial soybean cultivars with aphid resistance and there are no reported resistance sources in early maturing soybean germplasm. The objectives of this study were to identify sources and types of resistance to soybean aphid from early maturing soybean germplasm. Over a 2-yr period, 2147 soybean accessions from maturity group (MG) 0 to III, originally from northern China, were evaluated for aphid resistance in a greenhouse and in field cages. The plants were hand-inoculated and aphid populations were evaluated 10 d after inoculation. A damage index (0-100%) was calculated for each accession. After 2 yr of evaluation and confirmation in choice tests, four MG III accessions from Shandong province, PI 567543C, PI 567597C, PI 567541B, and PI 567598B, were found to be resistant to the soybean aphid. Two of these accessions, PI 567541B and PI 567598B, possessed antibiosis resistance, preventing the aphids from reproducing on the plants in a no-choice study. PI 567543C and PI 567597C possessed antixenosis resistance. These resistant sources can be used to develop commercial cultivars with aphid resistance for the North Central states., SOYBEAN is the leading oilseed crop produced and consumed worldwide (Wilcox, 2004). In the past half century, the USA has been the world's leading producer. In 2003, the USA produced [...]