172 research outputs found

    Morphometric analysis of the submarine landslides in the central Great Barrier Reef margin, north-eastern Australia

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    The morphometric characterization of the submarine landslides on a mixed siliciclastic-carbonate margin, the Great Barrier Reef (NE Australia), is presented in this study. The landslides cover about the 27% of the slope in the study region, removing in some examples up to 33 km 3 of sediment. Spearman rank correlation coefficients show meaningful correlations among landslide size parameters. However, there is no relationship between the unfailed slope in the source area and the size of the landslide. The mobility of the landslides is within the normal range observed in other submarine landslides worldwide. The results of this study represent a preliminary step to understand the sedimentary processes, preconditioning factors and triggering mechanisms for submarine landslide generation in mixed marginse presentan los resultados de la caracterización morfométrica de los deslizamientos submarinos en un margen continental mixto siliciclástico-carbonatado, el margen de la Gran Barrera de Arrecifes (NE Australia). Los deslizamientos abarcan aproximadamente el 27% de la superficie del talud en la zona de estudio, removilizando en algunos casos volúmenes de sedimento de hasta 33 km3. El análisis de correlación de Spearman indica que existe buena correlación entre los parámetros relacionados con las dimensiones del deslizamiento. Sin embargo, no se observa relación directa entre la pendiente del talud y las dimensiones de los deslizamientos. La movilidad de los deslizamientos se encuentra dentro del rango observado en otros deslizamientos submarinos. Los resultados de este trabajo constituyen un primer paso para entender los procesos sedimentarios y mecanismos de generación de deslizamientos en los márgenes de tipo mixt

    Pulmonary atresia with ventricular septal defect: Preoperative and postoperative responses to exercise

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    Between April 1982 and June 1984, maximal exercise testing was performed 35 times in 34 consecutive patients with pulmonary atresia and ventricular septal defect (14 studies in patients without repair, 11 studies in patients with partial repair [insertion of a right ventricle to pulmonary artery conduit without ventricular septal defect closure] and 10 studies in patients with complete repair [insertion of a conduit with septal defect closure]). Total work performed, maximal power achieved, exercise time and maximal oxygen uptake were significantly greater in patients after partial or complete repair than in patients without repair. Systemic arterial blood oxygen saturations at rest and during exercise were directly related to the degree of repair. Although heart rate at rest in the three study groups was similar to that in a separate group of normal control subjects, patients in all three study groups had a blunted heart rate response to exercise. The ventilatory equivalent for oxygen was increased both at rest and during exercise for patients without conduit repair and those with a right ventricle to pulmonary artery conduit without ventricular septal defect closure but was similar to that of control subjects in the group with conduit insertion and septal defect closure.This study indicates that patients with pulmonary atresia and ventricular septal defect have decreased exercise tolerance both before and after corrective surgery. Exercise tolerance improves significantly after placement of a conduit from the right ventricle to the pulmonary artery with or without ventricular septa) defect closure. Although no further improvement in exercise tolerance occurs with closure of the septal defect, ventilatory function and systemic arterial blood oxygen saturation are improved

    Deformaciones pliocenas y cuaternarias en la plataforma continental oriental del Algarve, Golfo de Cádiz

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    The eastern Algarve continental shelf in the northern margin of the Gulf of Cadiz has been investigated by analysing a set of high-resolution seismic reflection profiles. We examine the major structural elements affecting the upper sedimentary units. A seismo-stratigraphic interpretation and regional correlation allowed the identification of a major discontinuity that separates two main intervals, pre-Middle Pleistocene (MP) and post-MP. In addition, a number of deformation features such as ENE-WSW to NE-SW thrusts, kilometric-scale N-S to NW-SE folds and NNE-SSW to NNW-SSE sub-vertical normal faults were identified affecting the Pliocene-Quaternary sedimentary record, indicating neotectonic activity. The structures pre-dating MP are in agreement with a dominant transpressive regime along the continental shelf, under the Late Cenozoic NW-SE oblique convergence and related to the reactivation of Mesozoic diapiric structures. The structures post-dating MP induce a lower deformation of the sedimentary cover but were still active during the last glacial maximum, in agreement with the low uplift recognized in the Portuguese mainlandLa plataforma continental del Algarve en el margen septentrional del Golfo de Cádiz ha sido investigada mediante el análisis de una red de perfiles sísmicos de alta resolución. Se presentan las principales estructuras que afectan a la cobertera sedimentaria superficial. Una interpretación sismoestratigráfica y correlaciones a nivel regional han permitido diferenciar dos intervalos separados por una discontinuidad principal, anterior y posterior al Pleistoceno Medio (PM). Los depósitos del Plioceno y Cuaternario están deformados por estructuras de deformación tales como cabalgamientos ENEOSO a NE-SO, pliegues N-S a NO-SE de escala kilométrica y fallas subverticales NNE-SSO a NNO-SSE, que indican actividad neotectónica. Las estructuras anteriores al PM se generan en relación con el régimen transpresivo (NO-SE) dominante a fInales del Cenozoico en esta región y la reactivación de las estructuras diapíricas mesozoicas observadas en el margen. En cambio, las estructuras posteriores al PM producen una ligera deformación de la cobertera sedimentaria y actividad durante el último máximo glaciar, lo que concuerda con un moderado levantamiento tectónico observado en la zona continental del margen portugué

    Training in Values as an Incubator for Sustainability Attitudes

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    Following the proposals arising from the Schwartz model on the cognitive representationsof human needs expressed in his Theory of Values, instrumental values and terminalvalues, which are vital for understanding and entrepreneurship behavior, we have engagedin a critical review of this model and the types of values. We go on to examine the academiccurriculum of ethical and moral profiles as promoters of sustainable attitude values in orderto contribute an integrated and updated option to the academic world

    Protein-losing enteropathy after the Fontan operation

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    AbstractPatients were observed after the Fontan operation to determine the frequency and severity of protein-losing enteropathy. A total of 427 patients who survived for 30 days after the Fontan operation, performed between 1973 and January 1987, were analyzed and, thus far, protein-losing enteropathy has developed in 47 of 427. The cumulative risk for the development of protein-losing enteropathy by 10 years was 13.4% among 30-day survivors, and 5-year survival after the diagnosis was 46%. Hemodynamic studies done coincident with the diagnosis of protein-losing enteropathy have shown increased systemic venous pressure, decreased cardiac index, increased pulmonary vascular resistance, and increased ventricular end-diastolic pressure. Medical management of protein-losing enteropathy was only partially successful. Statistical analysis has shown that factors related to protein-losing enteropathy were ventricular anatomy, increased preoperative ventricular end-diastolic pressure, longer operative bypass time, increased length of hospital stay, and postoperative renal failure. This study suggests that scrupulous selection of cases for the Fontan operation is mandatory and that certain perioperative factors may predispose to this serious complication of the Fontan procedure. (J THORAC CARDIOVASC SURG 1996;112:672-80

    Resultados del tratamiento quirúrgico del dolor lumbar con instrumentación diapasón

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    Se presenta un estudio sobre 23 pacientes con patología lumbosacra tratados quirúrgicamente mediante artrodesis e instrumentación vertebral transpedicular tipo diapasón. El promedio de seguimiento ha sido de 25 meses (18-38). El dolor lumbar estaba relacionado en 10 casos con estenosis de canal, en 6 con espondilolistesis y en 7 con hernia discal y artrosis secundaria. Todos fueron instrumentados por vía posterior mediante fijación transpedicular y artrodesados posterolateralmente con injerto autólogo. Se consiguió una artrodesis sólida en un 96%. No se han presentado complicaciones preoperatorias. Ocho pacientes presentaron complicaciones en el postoperatorio inmediato. Observamos un desplazamiento de barra y un desanclaje del tornillo fuera del pedículo. Siguiendo los criterios de valoración de Henderson se ha conseguido un 96% de excelentes y buenos resultados.A series of 23 patient with lumbosacral pathology, surgically treated by posterior arthrodesis and vertebral diapason transpedicular fixation was retrospectively review. The average follow-up period was 25 months (18-38). The diagnosis was spinal stenosis in 10 cases, spondylolisthesis in 6, and disc herniation with secondary osteoartrhitis in 7 cases. Apart from transpedicular fixation all cases underwent posterolateral fusion with autogenous bone graft. A solid arthrodesis was achieved in a 96% of patients. There were no per-operative complication. Eight cases showed complications in the immediate postoperative period. We observed displacement of a bar and detachement of a screw out off the pedicle. According to Henderson's assessment criteria we obtained 96% of excellent and good results

    Intraoperative transesophageal echocardiography during surgery for congenital heart defects

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    AbstractObjective: This study was undertaken to further define the impact of intraoperative transesophageal echocardiography during surgery for congenital heart disease and to determine appropriate indications. Methods: The impact of transesophageal echocardiography on patient care was assessed in 1002 patients who underwent this procedure during surgery for congenital heart defects. It had major impact when new information altered the planned procedure or led to a revision of the initial repair. The safety of intraoperative transesophageal echocardiography was evaluated by review of the prospective data sheets and the medical record. A simple relative cost analysis was also performed. Results: Patient median age was 9.9 years (range 2 days to 85 years). Transesophageal echocardiography had prebypass or postbypass major impact in 13.8% of cases (n = 138/1002). Major impact was more frequent during reoperations (P <.03). Procedures that benefited most from the additional information were valve repairs (aortic or atrioventricular) and complex outflow tract reconstructions. Partial anomalous pulmonary venous connection, tricuspid valve repair (other than of Ebstein anomaly), simple atrioventricular discordance, aortic arch anomalies, and secundum atrial septal defects had major impact rates less than 5%. No major complications occurred. Minor complications occurred in 1% of patients and were most often observed in infants smaller than 4 kg. Routine use of transesophageal echocardiography for all patients with congenital heart defects proved cost-effective. Conclusions: On the combined basis of the observed rates of major impact, the minimal complications, and the relative cost advantage, we believe that routine use of transesophageal echocardiography during most intracardiac repairs of congenital heart defects is justified, particularly for patients undergoing repeat operations for congenital cardiac malformations.J Thorac Cardiovasc Surg 2002;124:1176-8

    Trends in adult asthma hospitalization: gender-age effect

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    BACKGROUND: Hospital admissions due to asthma are a reliable source of information on the morbidity of the disease which, after the increase observed in the last quarter of the last century, shows a declining trend in the last few years. The aim of this study was to look at hospital admission trends due to asthma in our community and analyze some of its associated factors. METHODS: Retrospective analysis of all hospital admissions involving adults aged 15 years and older with asthma as the primary or secondary diagnosis (if the first diagnosis was respiratory failure or respiratory infection) in Public Health Service hospitals in the Galician region of Spain between the years 1995-2009 (total 24,766 admissions). RESULTS: The majority of patients admitted were female (71%), over 60 years of age (64%), and admission occurred predominantly in the winter months. The hospitalization rate due to asthma tripled over the period studied, this being mainly accounted for by women aged over 60 years. Mean hospital stay was 9.2 days, longer in older patients or those admitted over the weekend. CONCLUSIONS: A significant increase in hospital admissions due to asthma over the last few years has been observed in our community, mainly involving older women. The mean stay seems long, increasing with patients' age and admission over the weekend

    Late Quaternary multi-genetic processes and products on the northern Gulf of Cadiz upper continental slope (SW Iberian Peninsula)

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    On continental margins, the upper slope to shelf break environment forms a critical region where sediment supply, hydrographic activity and gravitational processes determine how and when sediments are partitioned between the shallow- and deep-marine realm. On the SW Iberian margin, relatively few studies have addressed the dynamics of this region, although it holds key information regarding the link between the sedimentary evolution of the continental shelf and the contourite depositional system on the middle slope. This work therefore presents a high-resolution analysis of the morphological and stratigraphic expressions of late Quaternary (dominantly last glacial and present-day interglacial) sedimentary processes on the upper slope and shelf margin sector between 7° and 7°30’ W. The integration of seismic, bathymetric and hydrographic data reveals the presence of alongslope processes and products (a bottom current-related plastered drift, moat, erosional surface and terrace, an internal wave-/tide-controlled sediment wave field), downslope (gravitational) processes and products (an upper slope – shelf margin valley system, slumps, debrites, gullies), neotectonic elements (diapirs) and fluid flow features (pockmarks, bright spots). The spatial distribution of these features indicates that the study area becomes increasingly alongslope-dominated towards the W, and oppositely, more downslope-dominated towards the E, because sediment supply to the latter area is enhanced under the dominant eastward dispersal of fluvially supplied sediments on the shelf. In addition, glacial-interglacial variations in the amount of sediments supplied to the shelf edge and the intensity of oceanographic processes in the study area also generate a distinct temporal variability, with glacial and interglacial intervals respectively recording principally downslope- and alongslope-controlled morphological elements. Finally, regardless of these overall spatial and temporal patterns, diapirism and fluid flow are inferred to locally destabilize sediments and induce small-scale mass wasting in the study area. These findings are not only relevant to the northern Gulf of Cadiz, but also to the general understanding of sedimentary dynamics and controls in mixed downslope- and alongslope-controlled upper slope to shelf margin settings worldwide.T. Mestdagh is funded through a doctoral scholarship of the Ghent University Special Research Fund (BOF). We would like to thank the captains, crews and scientists involved in research campaigns COMIC 2013 on board of RV Belgica and LASEA 2013 on board of RV Ramón Margalef. Ship time on RV Belgica was provided by BELSPO and RBINS-OD Nature. This research was performed in collaboration with ”The Drifters” Research Group of the Royal Holloway University of London (UK), and is associated to projects CTM 2012-39599-C03 , CGL2016-80445-R ‘SCORE’ ( AEI/FEDER , UE), CTM2016-75129-C3-1-R , CGL2011-30302-C02-02 and CTM2017-88237-P . Editor Michele Rebesco and two anonymous reviewers are kindly acknowledged for providing constructive feedback
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