873 research outputs found

    Palaeogene to Early Miocene sedimentary history of the Sierra Espuña (Malaguide complex, internal zone of the Betic cordilleras, SE Spain). Evidence for extra-Malaguide (Sardinian?) provenance of oligocene conglomerates: Palaeogeographic implications

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    The Sierra Espuña is situated at the northern edge of the Internal Zone in the eastern Betic Cordilleras and is part of the unmetamorphosed Malaguide Complex. Palaeontological and sedimentological analysis of the Eocene to Aquitanian sediments on the northwest side of the Espuña yielded unexpected new information of importance for the reconstruction of the history of the Espuña itself and the Malaguides in general. The socalled Upper Eocene (Auversian) rocks are of Early Oligocene (P20) age and contain supermature detritus derived from outside the Malaguide realm. The hundreds of meters thick limestone conglomerate formation of the Espuña is of Middle Oligocene (P21) age and represents a backstepping fan delta complex at the margin of a carbonate platform situated to the northeast of the Espuña. Analysis of the clasts suggests that this platform was a part of the north Sardinian block given the majority of fragments of Upper Jurassic sheltered inner platform (Clypeina-Trocholina limestones and dolomites). Contrary to former views (Paquet, 1966; Lonergan, 1993), the conglomerates cannot be considered to be the erosional products of Malaguide imbricated units. Therefore, one of the main arguments for early (Late Eocene to Oligocene) thrusting and nappe emplacement in the Espuña area is not valido Other arguments for early kinematics are discussed, among others the allegedly continuous sedimentation from the Late Eocene until the Langhian northwest of the Espuña. Our data indicate the existence of a stratigraphic gap, comprising the middle Aquitanian to middle Burdigalian. A new model for the development of the Espuña within the Malaguide realm during the Palaeogene to Early Miocene is presented. Main thrusting and nappe emplacement is thought to have been taken place during the late Aquitanian. Finally, the recently proposed 2000 clockwise rotation of the Espuña as a coherent block during the Early to Middle Miocene (AlIerton el al., 1993) is discussed. It is shown that this large figure is at variance with geological data and partly due to erroneous field observations.La Sierra Espuña está situada al margen norte de la Zona Interna en la parte oriental de las Cordilleras Béticas y forma parte del Complejo Maláguide no metamórfico. Análisis paleontológico y sedimentológico de sedimentos de edad Eoceno al Aquitaniense del lado noroeste del Espuña han producido información nueva y de inesperada importancia respecto a la reconstrucción de la historia de la misma Sierra Espuña y del Maláguide en general. Los depósitos considerados del Eoceno superior (Auversiall) son de edad Oligoceno inferior (P20) y contienen materiales supermaduros procedentes de fuera del dominio Maláguide. Los conglomerados con cantos calizos de Sierra Espuña (cientos de metros de espesor) son de edad Oligoceno medio (P21) y representan un complejo de «fan deltas» en retroceso en el margen de una plataforma calcárea situada al nordeste de Sierra Espuña. Análisis de cantos podrían indicar que esta plataforma haya sido formada por parte del bloque del Norte de Cerdeña dado el predominio de fragmentos procedentes de una plataforma interior de edad Jurásico superior (calizas y dolomías con Clypeina y Trocholinu). Al contrario de los puntos de vista anteriores (Paquet, 1966; Lonergan, 1993), los conglomerados no pueden ser considerados como productos de erosión de unidades maláguides imbricadas. Por lo cual, uno de los argumentos más importantes en favor de una imbricación y colocación de mantos de corrimiento temprano (Eoceno superior-Oligoceno) en Espuña es inválido. Se discuten otros argumentos en favor de movimientos tempranos, entre otros la sedimentación supuestamente continua del Eoceno hasta el Langhiense al noroeste de Sierra Espuña. Nuestros datos han demostrado la existencia de una interrupción estratigráfica desde el Aquitaniense medio hasta el Burdigaliense medio. Se presenta un modelo nuevo para la historia de Sierra Espuña dentro del dominio Maláguide durante el Palaeogeno hasta el Mioceno inferior. Se supone que imbricaciones importantes y colocación de mantos tuvieron lugar en el Aquitaniense superior. Al final, se discute la rotación de Espuña como bloque coherente de 200σ en sentido horario durante el Mioceno inferior y medio (Allerton et al., 1993). Se ve demostrado que esta gran rotación está en contradicción con datos geológicos y en parte resulta de observaciones erróneas en el campo

    Regge phenomenology of pion photoproduction off the nucleon at forward angles

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    We present a Regge model for pion photoproduction which is basically free of parameters within the framework of the s-channel helicity amplitude. We use coupling constants of all exchanged mesons determined from empirical decay widths or from the SU(3) relations together with consistency check with existing estimates that are widely accepted in other reaction processes. Cross sections and spin polarization asymmetries at various photon energies are analyzed and results are obtained in better agreement with experimental data without referring to any fitting procedure.Comment: 19 pages, 20 figures, two column, revtex

    Reliability and validity of the vitiligo signs of activity score (VSAS)

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    Background The associations between disease activity and several clinical signs in vitiligo have been described, but a widely accepted and validated scoring system is lacking. Objectives To validate the Vitiligo Signs of Activity Score (VSAS) for physicians. Methods Three visible clinical signs were scored on 15 body locations: confetti-like depigmentation (c), Koebner phenomenon (k) and hypochromic areas/borders (h). The inter- and intrarater reliability of the global VSAS and VSAS subscores (c-VSAS, k-VSAS and h-VSAS) were tested by four and three raters (physicians), respectively. Construct validity and feasibility were evaluated. Results The VSAS demonstrated good inter-rater reliability, with an intraclass correlation coefficient (ICC) of 0 center dot 87 in the first round and 0 center dot 90 in the second round. The intrarater reliability ICCs were all >= 0 center dot 86. The inter-rater reliabilities of the subscores were excellent for c-VSAS and fair for k-VSAS and h-VSAS (ICC 0 center dot 83, 0 center dot 51 and 0 center dot 53, respectively, in the first round). Evidence for construct validity was provided. The completion time by the raters (median 2 center dot 18 min per patient) improved during the second round (median 1 center dot 33 min per patient). A limitation of the study is the low number of patients, mainly of skin phototypes II-III, from a single tertiary centre. Conclusions The VSAS appears to be a valid and reliable instrument to score visible clinical signs linked to disease activity in a standardized way. What is already known about this topic? Evidence exists for a possible link between several visible clinical signs in vitiligo and disease activity. A widely accepted and validated scoring system to quantify these clinical signs is lacking. What does this study add? The Vitiligo Signs of Activity Score (VSAS) underwent preliminary validation and may assist quantification of visible clinical signs linked to disease activity in a standardized way in clinical practice and trials

    The composition of serous fluid after axillary dissection

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    Objective: To analyse the composition of the serous fluid formed after axillary dissection Design: Descriptive study Setting: University hospital and teaching hospital, The Netherlands Subjects: 16 patients whose axillas were dissected as part of a modified radical mastectomy for stage I or II breast cancer. Main outcome measures: Chemical and cellular composition of axillary drainage fluid on the first, fifth, and tenth postoperative days compared with the same constituents in blood and with reported data on the composition of peripheral lymph. Results and conclusion: On the first postoperative day the drainage fluid contained blood contents and a high concentration of creatine phosphokinase (CPK). After day one it changed to a peripheral lymph-like fluid but containing different cells, more protein, and no fibrinogen, making coagulation impossible. The reduction in the fluid production must be caused by other wound healing processes, such as formation of scars and connective tissue

    Assessment of insertion techniques and complication rates of dual lumen central venous catheters in patients with hematological malignancies

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    One hundred and twenty-three dual lumen silicone rubber central venous catheters were inserted into 101 patients with hematological malignancies undergoing intensive treatment. There was a perioperative complication rate of 13%. Open and closed techniques for inserting the catheter were compared. The operating time needed for introducing the catheter by the closed technique (average, 51 minutes) was significantly shorter (p< 0.001) than the time needed for the open technique (70 minutes), whereas complication rates were equal in both techniques. On average, the catheters functioned for 149 days. Complications leading to removal were observed in 29.3% of patients, most of which were catheter-related infections (20.4%). Thromboembolic complications leading to removal were less frequent (4.1%) and appeared significantly earlier (p<0.001). These data indicate that introduction of the catheter by direct puncture of the subclavian vein is a quick and safe technique, and that this type of catheter is suitable for long-term use, both for infusion and for blood sampling

    The pedicled omentoplasty and split skin graft (POSSG) for reconstruction of large chest wall defects. A validity study of 34 patients

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    The aim of this study was to evaluate retrospectively the results of pedicled omentoplasty and split skin graft (POSSG) in reconstructing (full thickness) chest wall defects, and to define its role as a palliative procedure for local symptom control. Thirty-four patients with recurrent breast cancer (n = 25), radiation-induced necrosis (n = 5) or sarcoma (n = 4) of the chest wall were selected for the study. All patients underwent curative or palliative chest wall resection with reconstruction by pedicled omentoplasty and split skin graft (POSSG), between 1986 and 1994. Reconstructive outcome, complications, local tumour and symptom control following surgery was measured. The most common complication was shown to be partial necrosis of the omental flap (35%), followed by respiratory problems (26%), facial hernia (26%) and thoracic wound problems (15%), which were mostly treated in a conservative way (68%). The 3-year local tumour-free interval after POSSG in patients curatively treated for breast cancer is 16%. Seventy per cent of the patients who underwent palliative resection had longstanding relief of local pain, bleeding or foetor due to local tumour growth. It can be concluded that large (full thickness) chest wall defects after resection of local recurrence, primary malignancy or osteoradionecrosis of the chest wall can successfully be reconstructed by POSSG. Chest wall resection in patients treated with palliative intention is effective in local symptom control

    Structure-function relationships of glucansucrase and fructansucrase enzymes from lactic acid bacteria

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    Lactic acid bacteria (LAB) employ sucrase-type enzymes to convert sucrose into homopolysaccharides consisting of either glucosyl units (glucans) or fructosyl units (fructans). The enzymes involved are labeled glucansucrases (GS) and fructansucrases (FS), respectively. The available molecular, biochemical, and structural information on sucrase genes and enzymes from various LAB and their fructan and α-glucan products is reviewed. The GS and FS enzymes are both glycoside hydrolase enzymes that act on the same substrate (sucrose) and catalyze (retaining) transglycosylation reactions that result in polysaccharide formation, but they possess completely different protein structures. GS enzymes (family GH70) are large multidomain proteins that occur exclusively in LAB. Their catalytic domain displays clear secondary-structure similarity with α-amylase enzymes (family GH13), with a predicted permuted (β/α)8 barrel structure for which detailed structural and mechanistic information is available. Emphasis now is on identification of residues and regions important for GS enzyme activity and product specificity (synthesis of α-glucans differing in glycosidic linkage type, degree and type of branching, glucan molecular mass, and solubility). FS enzymes (family GH68) occur in both gram-negative and gram-positive bacteria and synthesize β-fructan polymers with either β-(2→6) (inulin) or β-(2→1) (levan) glycosidic bonds. Recently, the first high-resolution three-dimensional structures have become available for FS (levansucrase) proteins, revealing a rare five-bladed β-propeller structure with a deep, negatively charged central pocket. Although these structures have provided detailed mechanistic insights, the structural features in FS enzymes dictating the synthesis of either β-(2→6) or β-(2→1) linkages, degree and type of branching, and fructan molecular mass remain to be identified

    Modern and fossil non-pollen palynomorphs from the Basque mountains (western Pyrenees, France): the use of coprophilous fungi to reconstruct pastoral activity

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    International audienceThis paper presents results from a modern dataset of non-pollen palynomorphs and its application to aca. 2,000 year peat record from the same area in the western Pyrenees (Basque Country, France). The modern dataset is composed of 35 surface samples (moss polsters) from a mountainous pasture-woodland landscape. Airborne fungal spores (ascospores and conidia), found dominant in the dataset, are linked to the degree of landscape openness and grazing pressure. The complete spectrum of 13 selected spore-types of dung-related Ascomycetes is positively linked with grazing pressure. However, different dung affinities between the spore-types have been identified. These are types clearly related to high grazing pressure and types with no or unclear dung indicative value. The modern dataset is used to aid interpretation of the local fossil pollen record as an independent 'proxy' to assess past pastoral dynamics. This study confirms the utility of modern nonpollen palynomorphs from terrestrial ecosystems in the reconstruction of historical local pastoral activities but also shows their limitation. It may be necessary to extend such study to wetland ecosystems and to investigate the spatial dimension of some fungal spores

    Unpolarized fragmentation function for the pion and kaon via the nonlocal chiral-quark model

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    In this talk we present our recent studies for the unpolarized fragmentation functions for the pion and kaon, employing the nonlocal chiral quark model, which manifests the nonlocal interaction between the quarks and pseudoscalar mesons, in the light-cone frame. It turns out that the nonlocal interaction produces considerable differences in comparison to typical local-interaction models.Comment: 4 pages, 2 figures, Talk given at the international conference The Fifth Asia-Pacific Conference on Few-Body Systems in Physics 2011 (APFB2011), Seoul, Republic of Korea, 22-26 August 201

    Does experience influence the forces exerted on maxillary incisors during laryngoscopy? A manikin study using the Macintosh laryngoscope

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    The influence of the level of experience of the laryngoscopist on the duration of laryngoscopy, the forces exerted on the tongue and on the maxillary incisors during laryngoscopy, were investigated. Five groups (anaesthetists, residents in anaesthesia, nurse anaesthetists, surgeons and medical students), each consisting of 15 individuals, participated in the study. An intubation manikin was used with a laryngoscope modified so that the forces applied during laryngoscopy could be measured. The mean duration of laryngoscopy in these groups was 23.4 sec, 17.6 sec, 27.1 sec, 26.8 sec and 42.7 sec, respectively. The maximally applied forces on the tongue were 71.7 N, 60.5 N, 65.9 N, 74.2 N and 69.7 N, respectively. The maximally applied forces on the maxillary incisors were 49.9 N, 36.3 N, 41.1 N, 58.3 N and 53.9 N, respectively. These results indicate the level of experience has a significant influence on the duration of laryngoscopy but seems to have little influence on the forces applied to the tongue and the maxillary incisors
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