170 resultados para Sylvian fissure
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OBJECT: Preliminary experience with the C-Port Flex-A Anastomosis System (Cardica, Inc.) to enable rapid automated anastomosis has been reported in coronary artery bypass surgery. The goal of the current study was to define the feasibility and safety of this method for high-flow extracranial-intracranial (EC-IC) bypass surgery in a clinical series. METHODS: In a prospective study design, patients with symptomatic carotid artery (CA) occlusion were selected for C-Port-assisted high-flow EC-IC bypass surgery if they met the following criteria: 1) transient or moderate permanent symptoms of focal ischemia; 2) CA occlusion; 3) hemodynamic instability; and 4) had provided informed consent. Bypasses were done using a radial artery graft that was proximally anastomosed to the superficial temporal artery trunk, the cervical external, or common CA. All distal cerebral anastomoses were performed on M2 branches using the C-Port Flex-A system. RESULTS: Within 6 months, 10 patients were enrolled in the study. The distal automated anastomosis could be accomplished in all patients; the median temporary occlusion time was 16.6+/-3.4 minutes. Intraoperative digital subtraction angiography (DSA) confirmed good bypass function in 9 patients, and in 1 the anastomosis was classified as fair. There was 1 major perioperative complication that consisted of the creation of a pseudoaneurysm due to a hardware problem. In all but 1 case the bypass was shown to be patent on DSA after 7 days; furthermore, in 1 patient a late occlusion developed due to vasospasm after a sylvian hemorrhage. One-week follow-up DSA revealed transient asymptomatic extracranial spasm of the donor artery and the radial artery graft in 1 case. Two patients developed a limited zone of infarction on CT scanning during the follow-up course. CONCLUSIONS: In patients with symptomatic CA occlusion, C-Port Flex-A-assisted high-flow EC-IC bypass surgery is a technically feasible procedure. The system needs further modification to achieve a faster and safer anastomosis to enable a conclusive comparison with standard and laser-assisted methods for high-flow bypass surgery.
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BACKGROUND Rubber dam is recommended for isolating the working field during adhesive dentistry procedures; however, dentists often omit rubber dam, particularly in paediatric dentistry, supposing that it would stress the patient. AIM The aim of this study was to evaluate stress parameters during a standardized dental treatment procedure performed with or without rubber dam. The treatment time was measured as a secondary outcome variable. DESIGN This study was designed as a randomized, controlled, clinical study with 72 patients (6-16 years; mean age, 11.1). During standardized fissure sealing procedures, objective parameters of stress (e.g., skin resistance, breath rate) were recorded. The operator's stress level was measured by pulse rate. Subjective pain (patients) and stress perception (operator) were evaluated by an interview. RESULTS The breath rate was significantly (P<0.05) lower and the skin resistance level was significantly higher during treatment with rubber dam compared to the control group. Subjective pain perception was significantly lower for the test group. The treatment time needed for the fissure sealing procedure was 12.4% less in the test group. CONCLUSION Isolation with rubber dam caused less stress in children and adolescents compared to relative isolation with cotton rolls if applied by an experienced dentist.
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[1] Two millimeter-sized hydrothermal monazites from an open fissure (cleft) that developed late during a dextral transpressional deformation event in the Aar Massif, Switzerland, have been investigated using electron microprobe and ion probe. The monazites are characterized by high Th/U ratios typical of other hydrothermal monazites. Deformation events in the area have been subdivided into three phases: (D1) main thrusting including formation of a new schistosity, (D2) dextral transpression, and (D3) local crenulation including development of a new schistosity. The two younger deformational structures are related to a subvertically oriented intermediate stress axis, which is characteristic for strike slip deformation. The inferred stress environment is consistent with observed kinematics and the opening of such clefts. Therefore, the investigated monazite-bearing cleft formed at the end of D2 and/or D3, and during dextral movements along NNW dipping planes. Interaction of cleft-filling hydrothermal fluid with wall rock results in rare earth element (REE) mineral formation and alteration of the wall rock. The main newly formed REE minerals are Y-Si, Y-Nb-Ti minerals, and monazite. Despite these mineralogical changes, the bulk chemistry of the system remains constant and thus these mineralogical changes require redistribution of elements via a fluid over short distances (centimeter). Low-grade alteration enables local redistribution of REE, related to the stability of the accessory phases. This allows high precision isotope dating of cleft monazite. 232Th/208Pb ages are not affected by excess Pb and yield growth domain ages between 8.03 ± 0.22 and 6.25 ± 0.60 Ma. Monazite crystallization in brittle structures is coeval or younger than 8 Ma zircon fission track data and hence occurred below 280°C.
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We used micro-infusions during eyelid conditioning in rabbits to investigate the relative contributions of cerebellar cortex and the underlying deep nuclei (DCN) to the expression of cerebellar learning. These tests were conducted using two forms of cerebellum-dependent eyelid conditioning for which the relative roles of cerebellar cortex and DCN are controversial: delay conditioning, which is largely unaffected by forebrain lesions, and trace conditioning, which involves interactions between forebrain and cerebellum. For rabbits trained with delay conditioning, silencing cerebellar cortex by micro-infusions of the local anesthetic lidocaine unmasked stereotyped short-latency responses. This was also the case after extinction as observed previously with reversible blockade of cerebellar cortex output. Conversely, increasing cerebellar cortex activity by micro-infusions of the GABA(A) antagonist picrotoxin reversibly abolished conditioned responses. Effective cannula placements were clustered around the primary fissure and deeper in lobules hemispheric lobule IV (HIV) and hemispheric lobule V (HV) of anterior lobe. In well-trained trace conditioned rabbits, silencing this same area of cerebellar cortex or reversibly blocking cerebellar cortex output also unmasked short-latency responses. Because Purkinje cells are the sole output of cerebellar cortex, these results provide evidence that the expression of well-timed conditioned responses requires a well-timed decrease in the activity of Purkinje cells in anterior lobe. The parallels between results from delay and trace conditioning suggest similar contributions of plasticity in cerebellar cortex and DCN in both instances.
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Présentation du numéro de La Revue des sciences humaines no 317: Robert Pinget. Inédits (textes réunis par Clothilde Roullier et Patrick Suter). L’œuvre de Robert Pinget s’est étoffée depuis quelques années de nombreux inédits, dont La Fissure, publiée en 2009 par Clothilde Roullier dans la collection «Le métier à tisser», dirigée par Patrick Suter chez MētisPresses. Ce numéro de la RSH revient sur ces inédits à travers un dossier critique (contributions de C. Roullier, J. Kaempfer, M. Mégevand & P. Suter), tout en en proposant d’autres : Le Couloir, adapté à partir de 3 manuscrits de Pinget par L. Koechlin ; la correspondance Pinget – Robbe-Grillet, ainsi que de nombreux documents inédits).
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L’œuvre de Robert Pinget s’est étoffée depuis quelques années de nombreux inédits, dont La Fissure, publiée en 2009 par Clothilde Roullier dans la collection «Le métier à tisser», dirigée par Patrick Suter chez MētisPresses. Ce numéro de la RSH revient sur ces inédits à travers un dossier critique (contributions de C. Roullier, J. Kaempfer, M. Mégevand & P. Suter), tout en en proposant d’autres : Le Couloir, adapté à partir de 3 manuscrits de Pinget par L. Koechlin ; la correspondance Pinget – Robbe-Grillet, ainsi que de nombreux documents inédits).
Chemical composition and isotopic ratios of basic lavas from Iceland and the surrounding ocean floor
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Major and trace dement data are used to establish the nature and extent of spatial and temporal chemical variations in basalts erupted in the Iceland region of the North Atlantic Ocean. The ocean floor samples are those recovered by legs 38 and 49 of the Deep Sea Drilling Project. Within each of the active zones on Iceland there are small scale variations in the light rare earth elements and ratios such as K/Y: several central complexes and their associated fissure swarms erupt basalts with values of K/Y distinct from those erupted at adjacent centres; also basalts showing a wide range of immobile trace element ratios occur together within single vertical sections and ocean floor drill holes. Although such variations can be explained in terms of the magmatic processes operating on Iceland they make extrapolations from single basalt samples to mantle sources underlying the outcrop of the sample highly tenuous. 87Sr/86Sr ratios measured for 25 of the samples indicate a total range from 0.7028 in a tholeiite from the Reykjanes Ridge to 0.7034 in an alkali basalt from Iceland and are consistent with other published ratios from the region. A positive correlation between 87Sr/86Sr and Ce/Yb ratios indicates the existence of systematic isotopic and elemental variations in the mantle source region. An approximately fivefold variation in Ce/Yb ratio observed in basalts with the same 87Sr/86Sr ratio implies that different degrees and types of partial melting have been involved in magma genesis from a single mantle composition. 87Sr/86Sr ratios above 0.7028, Th/U ratios close to 4 and La/Ta ratios close to 10 distinguish most basalts erupted in this part of the North Atlantic Ocean from normal mid-ocean ridge basalt (N-type MORB) - although N-type MORB has been erupted at extinct spreading axes just to the north and northeast of Iceland as well as the presently active Iceland-Jan Mayen Ridge. Comparisons with the hygromagmatophile element and radiogenic isotope ratios of MORB and the estimated primordial mantle indicate that the mantle sources producing Iceland basalts have undergone previous depletion followed by more recent enrichment events. A veined mantle source region is proposed in preference to the mantle plume model to explain the chemical variations.
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En el presente trabajo se evaluaron 4 casos clínicos de pacientes con riesgo de caries pero que poseían molares sin lesiones, a los cuales se les colocó selladores de fosas y fisuras: en dos pacientes con resina y en dos pacientes con ionómero de vidrio. Los mismos fueron controlados en su permanencia en boca, los de resina en 6 meses y los de ionómero en 2 años, no encontrándose diferencias clínicas entre los materiales utilizados, debido a la diferencia en el tiempo de control de los mismos. Paralelamente, se realizó un trabajo in vitro con dos grupos de 10 molares cada uno, tratados el grupo 1 con sellador a base de resina y el grupo 2 con sellador de ionómero de vidrio. Luego de someter las muestras a la acción de un colorante (azul de metileno) se seccionaron longitudinalmente y se observaron en una lupa estereoscópica para ver si el colorante había penetrado o no por la interfase sellador/esmalte. No se encontraron diferencias estadísticamente significativas (a>0.05) entre los grupos analizados.
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Desde una constelación de poemas clave -"Caupolicán" (1888) de Rubén Darío, "Amor de ciudad grande" (1882) de José Martí y "En el campo" (1893) de Julián del Casal-, el análisis traza las diferencias en la articulación de una categoría fundante del siglo XIX latinoamericano en lo que va del romanticismo al modernismo. Si el concepto de "civilización" es el soporte del orden emergente que define roles sociales y nacionales en la nueva distribución global del XIX, su carácter intrínsecamente antinómico produce un racimo de oposiciones binarias -igualmente jerárquicas y valorativas- como cultura-naturaleza y ciudad-campo. Bajo estas condiciones, el romanticismo latinoamericano encontró en la nueva relación de la subjetividad con el entorno un camino para ensayar su estética, al re-culturizar el espacio natural para integrarlo al proceso de construcción de identidades nacionales. Desde las coordenadas de una fractura en esta tradición, los poemas del modernismo reconfiguran la antinomia entre naturaleza y cultura en una nueva inflexión que termina afectando los resortes de legitimación de un proyecto estético. En particular, nuestra hipótesis se aproxima al ritmo poético entendiéndolo como una fisura en la "ciudad letrada", el elemento propulsor de una nueva institución literaria que -mientras transforma el paradigma opositivo civilización-barbarie, original-copia, local-universal- contribuye a deslindar la autoridad del poeta modernista respecto del modelo del letrado tradicional
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Desde una constelación de poemas clave -"Caupolicán" (1888) de Rubén Darío, "Amor de ciudad grande" (1882) de José Martí y "En el campo" (1893) de Julián del Casal-, el análisis traza las diferencias en la articulación de una categoría fundante del siglo XIX latinoamericano en lo que va del romanticismo al modernismo. Si el concepto de "civilización" es el soporte del orden emergente que define roles sociales y nacionales en la nueva distribución global del XIX, su carácter intrínsecamente antinómico produce un racimo de oposiciones binarias -igualmente jerárquicas y valorativas- como cultura-naturaleza y ciudad-campo. Bajo estas condiciones, el romanticismo latinoamericano encontró en la nueva relación de la subjetividad con el entorno un camino para ensayar su estética, al re-culturizar el espacio natural para integrarlo al proceso de construcción de identidades nacionales. Desde las coordenadas de una fractura en esta tradición, los poemas del modernismo reconfiguran la antinomia entre naturaleza y cultura en una nueva inflexión que termina afectando los resortes de legitimación de un proyecto estético. En particular, nuestra hipótesis se aproxima al ritmo poético entendiéndolo como una fisura en la "ciudad letrada", el elemento propulsor de una nueva institución literaria que -mientras transforma el paradigma opositivo civilización-barbarie, original-copia, local-universal- contribuye a deslindar la autoridad del poeta modernista respecto del modelo del letrado tradicional
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Drilling at Ocean Drilling Program Site 802 in the central Mariana Basin, northwest Pacific Ocean, revealed an unexpected 222-m-thick sequence of well-cemented tuff of Miocene age. The deposits are unusual in that their source is presumably an unmapped seamount and they exhibit several peculiar petrological and mineralogical features. The well-developed secondary mineral sequence which includes analcime is rare in such relatively young, unburied deposits, in an area where there is little other evidence of hydrothermal activity. The massive tuff section also contains abundant fissure veins made of a rare silicate carbonate sulfate hydroxide hydrate of calcium, called thaumasite, which has not before been described in deep submarine deposits. The smectite-zeolite-thaumasite paragenesis coincides with the presence of chloride and calcium-enriched interstitial waters. The diagenetic evolution of the deposit appears to have been largely controlled by the depositional mode. The discharges of disaggregated and rejuvenated volcaniclasts seem to have been abrupt and repeated. The Miocene tuff at Site 802 thus provides new insights on the interactions between basaltic glass, biogenic phases, and seawater, in a specific deep-sea environment.
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Desde una constelación de poemas clave -"Caupolicán" (1888) de Rubén Darío, "Amor de ciudad grande" (1882) de José Martí y "En el campo" (1893) de Julián del Casal-, el análisis traza las diferencias en la articulación de una categoría fundante del siglo XIX latinoamericano en lo que va del romanticismo al modernismo. Si el concepto de "civilización" es el soporte del orden emergente que define roles sociales y nacionales en la nueva distribución global del XIX, su carácter intrínsecamente antinómico produce un racimo de oposiciones binarias -igualmente jerárquicas y valorativas- como cultura-naturaleza y ciudad-campo. Bajo estas condiciones, el romanticismo latinoamericano encontró en la nueva relación de la subjetividad con el entorno un camino para ensayar su estética, al re-culturizar el espacio natural para integrarlo al proceso de construcción de identidades nacionales. Desde las coordenadas de una fractura en esta tradición, los poemas del modernismo reconfiguran la antinomia entre naturaleza y cultura en una nueva inflexión que termina afectando los resortes de legitimación de un proyecto estético. En particular, nuestra hipótesis se aproxima al ritmo poético entendiéndolo como una fisura en la "ciudad letrada", el elemento propulsor de una nueva institución literaria que -mientras transforma el paradigma opositivo civilización-barbarie, original-copia, local-universal- contribuye a deslindar la autoridad del poeta modernista respecto del modelo del letrado tradicional
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Stockwork-like metal sulfide mineralizations were found at 910-928 m below seafloor (BSF) in the pillow/dike transition zone of Hole 504B. This is the same interval where most physical properties of the 5.9-m.y.-old crust of the Costa Rica Rift change from those characteristic of Layer 2B to those of Layer 2C. The pillow lavas, breccias, and veins of the stockwork-like zone were studied by transmitted and reflected light microscopy, X-ray diffraction, and electron microprobe analysis. Bulk rock oxygen isotopic analyses as well as isolated mineral oxygen and sulfur isotopic analyses and fluid inclusion measurements were carried out. A complex alteration history was reconstructed that includes three generations of fissures, each followed by precipitation of characteristic hydrothermal mineral parageneses: (1) Minor and local deposition of quartz occurred on fissure walls; adjacent wall rocks were silicified, followed by formation of chlorite and minor pyrite I in the veins, whereas albite, sphene, chlorite and chlorite-expandable clay mixtures, actinolite, and pyrite replaced igneous phases in the host rocks. The hydrothermal fluids responsible for this first stage were probably partially reacted seawater, and their temperatures were at least 200-250° C. (2) Fissures filled during the first stage were reopened and new cracks formed. They were filled with quartz, minor chlorite and chlorite-expandable clay mixtures, traces of epidote, common pyrite, sphalerite, chalcopyrite, and minor galena. During the second stage, hydrothermal fluids were relatively evolved metal- and Si-rich solutions whose temperatures ranged from 230 to 340° C. The fluctuating chemical composition and temperature of the solutions produced a complex depositional sequence of sulfides in the veins: chalcopyrite I, ± Fe-rich sphalerite, chalcopyrite II ("disease"), Fe-poor sphalerite, chalcopyrite III, galena, and pyrite II. (3) During the last stage, zeolites and Mg-poor calcite filled up the remaining spaces and newly formed cracks and replaced the host rock plagioclase. Analcite and stilbite were first to form in veins, possibly at temperatures below 200°C; analcite and earlier quartz were replaced by laumontite at 250°C, whereas calcite formation temperature ranged from 135 to 220°C. The last stage hydrothermal fluids were depleted in Mg and enriched in Ca and 18O compared to seawater and contained a mantle carbon component. This complex alteration history paralleling a complex mineral paragenesis can be interpreted as the result of a relatively long-term evolution of a hydrothermal system with superimposed shorter term fluctuations in solution temperature and composition. Hydrothermal activity probably began close to the axis of the Costa Rica Rift with the overall cooling of the system and multiple fracturing stages due to movement of the crust away from the axis and/or cooling of a magmatic heat source.
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It is the author’s position that the framework for WID/GAD, as academic field and practice concerned primarily with developing countries should be broadened so as to incorporate Japan’s own gender and development issues in its scope. Unlike other developed countries, activists and scholars in Japan rarely connected, as was also the case with the fields of women’s/gender studies and WID/GAD. However, this was not due to any lack of interest among Japanese women regarding the lives of women in developing countries. Rather the points of fissure were the notions of ‘difference’ and ‘development’ held by Japanese women. These analytical concepts were narrowly defined, which resulted in limited interaction between discourse on women’s issues in Japan and WID/GAD related to ‘other’ women. By re-examining these notions and looking more deeply into perceived differences in the local context of ‘development’, not only can we strategize on ‘differences’ in such a way that we draw strength from the very fact of being different, but also prevent ‘differences’ from being used as grounds for discrimination. As a whole, we could gain substantially by broadening the field of Gender and Development and, as such, it is imperative that this field be broadened with urgency as development itself changes in this ever-interconnected world
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In nature, several types of landforms have simple shapes: as they evolve they tend to take on an ideal, simple geometric form such as a cone, an ellipsoid or a paraboloid. Volcanic landforms are possibly the best examples of this ?ideal? geometry, since they develop as regular surface features due to the point-like (circular) or fissure-like (linear) manifestation of volcanic activity. In this paper, we present a geomorphometric method of fitting the ?ideal? surface onto the real surface of regular-shaped volcanoes through a number of case studies (Mt. Mayon, Mt. Somma, Mt. Semeru, and Mt. Cameroon). Volcanoes with circular, as well as elliptical, symmetry are addressed. For the best surface fit, we use the minimization library MINUIT which is made freely available by the CERN (European Organization for Nuclear Research). This library enables us to handle all the available surface data (every point of the digital elevation model) in a one-step, half-automated way regardless of the size of the dataset, and to consider simultaneously all the relevant parameters of the selected problem, such as the position of the center of the edifice, apex height, and cone slope, thanks to the highly performing adopted procedure. Fitting the geometric surface, along with calculating the related error, demonstrates the twofold advantage of the method. Firstly, we can determine quantitatively to what extent a given volcanic landform is regular, i.e. how much it follows an expected regular shape. Deviations from the ideal shape due to degradation (e.g. sector collapse and normal erosion) can be used in erosion rate calculations. Secondly, if we have a degraded volcanic landform, whose geometry is not clear, this method of surface fitting reconstructs the original shape with the maximum precision. Obviously, in addition to volcanic landforms, this method is also capable of constraining the shapes of other regular surface features such as aeolian, glacial or periglacial landforms.