34 research outputs found

    Cordgrass canopy elicits weak effects on sediment properties and microphytobenthic abundance in a harsh environment

    Get PDF
    The magnitude of the outcome of ecosystem engineering is context-dependent; asenvironmental stresses increase, habitat amelioration by ecosystem engineers becomes more relevant. Moreover, the individual- and population-level traits of ecosystem engineers can affect their ability to reduce environmental stress. On the Patagonian shores of Argentina (SW Atlantic,41° S), the intertidal community is exposed to harsh conditions. We predicted that in this severe environment, variation in the above-ground structure of the smooth cordgrass Spartina alterniflora should buffer the physical stress on the substrate through shading and reduction of wind and water flow energy, ultimately affecting the sediment properties and microphytobenthic biomass. To test this hypothesis, we experimentally manipulated cordgrass density at the edge and inner marsh of a S. alterniflora meadow during both summer and winter. In summer, evaporation andtemperature were higher in clipped plots, while in winter, evaporation varied across densities and location treatments, with higher sediment water content in the inner marsh. No effect of S. alterniflora density or location were observed on sediment organic matter or chl a concentration, and mean sediment grain size was always smaller inside the marsh. In summer, extracellular polymeric substance (EPS) content was higher in clipped plots inside the marsh, however this did not differ from the other density treatments at this location. Overall, shading had weak effects on sediment properties and microphytobenthic biomass, and most observed differences were attributable to grain size. We speculate that the harsh conditions of this system overwhelm the ecosystem engineering effects of S. alterniflora, probably because of its relatively small aboveground biomass.Fil: Firstater, Fausto Nahuel. Universidad Nacional del Comahue. Instituto de Biología Marina y Pesquera Almirante Storni; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Narvarte, Maite Andrea. Universidad Nacional del Comahue. Instituto de Biología Marina y Pesquera Almirante Storni; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Alvarez, María Fernanda. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Limnología "Dr. Raúl A. Ringuelet". Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Instituto de Limnología; ArgentinaFil: Fanjul, Maria Eugenia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencia Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Iribarne, Oscar Osvaldo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencia Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentin

    Predictive analysis of optical ablation in several dermatological tumoral tissues

    Get PDF
    Optical techniques for treatment and characterization of biological tissues are revolutionizing several branches of medical praxis, for example in ophthalmology or dermatology. The non-invasive, non-contact and non-ionizing character of optical radiation makes it specially suitable for these applications. Optical radiation can be employed in medical ablation applications, either for tissue resection or surgery. Optical ablation may provide a controlled and clean cut on a biological tissue. This is particularly relevant in tumoral tissue resection, where a small amount of cancerous cells could make the tumor appear again. A very important aspect of tissue optical ablation is then the estimation of the affected volume. In this work we propose a complete predictive model of tissue ablation that provides an estimation of the resected volume. The model is based on a Monte Carlo approach for the optical propagation of radiation inside the tissue, and a blow-off model for tissue ablation. This model is applied to several types of dermatological tumoral tissues, specifically squamous cells, basocellular and infiltrative carcinomas. The parameters of the optical source are varied and the estimated resected volume is calculated. The results for the different tumor types are presented and compared. This model can be used for surgical planning, in order to assure the complete resection of the tumoral tissue.This work has been partially supported by the project MAT2012-38664-C02-01 of the Spanish Ministery of Economy and Competitiveness, and by the San Cándido Foundation

    In-situ testing of innovative marine instrumentation for nutrients, heavy metals and pH in Kongsfjorden, Svalbard Islands

    Get PDF
    Marine ecosystems are integral part of fundamental environmental functions that support life on Earth like climate control, erosion prevention and absorption of carbon dioxide. Oceans contribute to economical activities too with the following prosperity, social welfare, and increase in life quality. Nevertheless, several marine environments also in the European framework show increasing challenges to tackle like the loss of biodiversity and habitats, pollution and impacts due to climate change. For Italy and for Europe a growing environmental interest and awareness in both the public and private sectors is combined with a common strategic goal to ensure sustainable development and the continuity of economic activities. In order to achieve this goal and to improve the competitiveness of Italy and the EU, new technologies and methods for monitoring the marine environment are required

    Tidal action and macroalgal photosynthetic activity prevent coastal acidification in an eutrophic system within a semi-desert region

    Get PDF
    Nutrient input drive macroalgal blooms and increases in photosynthetic activity in coastal ecosystems. An intense macroalgal photosynthetic activity can increase the surrounding pH and it could prevent the acidification that often follows an eutrophication process. We tested this hypothesis with field sampling and experiments in a macrotidal (up to 9 m in amplitude) coastal system within a semi-desert region with contrasting eutrophic conditions and Ulva lactuca blooms in the northern Argentinean Patagonia (San Antonio Bay). Our results indicate that daily pH variability during low tide could be controlled by the photosynthetic activity of Ulva lactuca under eutrophic conditions. At seasonal scale, the pH variations were related to environmental features, particularly seawater temperature. Both environmental (i.e. high solar radiation, negligible freshwater inputs and large tidal action) and anthropogenic nutrient inputs into the studied area promote the Ulva lactuca blooms, which in turn increases the surrounding pH in well oxygenated seawater through the intense photosynthetic activity. Our study shows that eutrophication instead of being a driver of acidification, could contribute to its prevention in well oxygenated marine coastal systems located within semi-desert regions.Fil: Becherucci, Maria Eugenia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Pereyra, Patricio Javier. Universidad Nacional del Comahue. Centro de Investigación Aplicada y Transferencia Tecnológica en Recursos Marinos "Almirante Storni". - Provincia de Río Negro. Ministerio de Agricultura, Ganadería y Pesca. Centro de Investigación Aplicada y Transferencia Tecnológica en Recursos Marinos "Almirante Storni". Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet Centro Nacional Patagónico. Centro de Investigación Aplicada y Transferencia Tecnológica en Recursos Marinos "Almirante Storni"; ArgentinaFil: Narvarte, Maite Andrea. Universidad Nacional del Comahue. Centro de Investigación Aplicada y Transferencia Tecnológica en Recursos Marinos "Almirante Storni". - Provincia de Río Negro. Ministerio de Agricultura, Ganadería y Pesca. Centro de Investigación Aplicada y Transferencia Tecnológica en Recursos Marinos "Almirante Storni". Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet Centro Nacional Patagónico. Centro de Investigación Aplicada y Transferencia Tecnológica en Recursos Marinos "Almirante Storni"; ArgentinaFil: Fanjul, Maria Eugenia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Iribarne, Oscar Osvaldo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Martinetto, Paulina Maria del Rosario. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentin

    Copernicus Ocean State Report, issue 6

    Get PDF
    The 6th issue of the Copernicus OSR incorporates a large range of topics for the blue, white and green ocean for all European regional seas, and the global ocean over 1993–2020 with a special focus on 2020

    Mortality and pulmonary complications in patients undergoing surgery with perioperative SARS-CoV-2 infection: an international cohort study

    Get PDF
    Background: The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on postoperative recovery needs to be understood to inform clinical decision making during and after the COVID-19 pandemic. This study reports 30-day mortality and pulmonary complication rates in patients with perioperative SARS-CoV-2 infection. Methods: This international, multicentre, cohort study at 235 hospitals in 24 countries included all patients undergoing surgery who had SARS-CoV-2 infection confirmed within 7 days before or 30 days after surgery. The primary outcome measure was 30-day postoperative mortality and was assessed in all enrolled patients. The main secondary outcome measure was pulmonary complications, defined as pneumonia, acute respiratory distress syndrome, or unexpected postoperative ventilation. Findings: This analysis includes 1128 patients who had surgery between Jan 1 and March 31, 2020, of whom 835 (74·0%) had emergency surgery and 280 (24·8%) had elective surgery. SARS-CoV-2 infection was confirmed preoperatively in 294 (26·1%) patients. 30-day mortality was 23·8% (268 of 1128). Pulmonary complications occurred in 577 (51·2%) of 1128 patients; 30-day mortality in these patients was 38·0% (219 of 577), accounting for 81·7% (219 of 268) of all deaths. In adjusted analyses, 30-day mortality was associated with male sex (odds ratio 1·75 [95% CI 1·28–2·40], p\textless0·0001), age 70 years or older versus younger than 70 years (2·30 [1·65–3·22], p\textless0·0001), American Society of Anesthesiologists grades 3–5 versus grades 1–2 (2·35 [1·57–3·53], p\textless0·0001), malignant versus benign or obstetric diagnosis (1·55 [1·01–2·39], p=0·046), emergency versus elective surgery (1·67 [1·06–2·63], p=0·026), and major versus minor surgery (1·52 [1·01–2·31], p=0·047). Interpretation: Postoperative pulmonary complications occur in half of patients with perioperative SARS-CoV-2 infection and are associated with high mortality. Thresholds for surgery during the COVID-19 pandemic should be higher than during normal practice, particularly in men aged 70 years and older. Consideration should be given for postponing non-urgent procedures and promoting non-operative treatment to delay or avoid the need for surgery. Funding: National Institute for Health Research (NIHR), Association of Coloproctology of Great Britain and Ireland, Bowel and Cancer Research, Bowel Disease Research Foundation, Association of Upper Gastrointestinal Surgeons, British Association of Surgical Oncology, British Gynaecological Cancer Society, European Society of Coloproctology, NIHR Academy, Sarcoma UK, Vascular Society for Great Britain and Ireland, and Yorkshire Cancer Research

    Análisis de propiedades espectroscópicas de fluoróforos utilizados en el diagnóstico clínico

    No full text
    Las técnicas ópticas se emplean habitualmente en la práctica médica para el tratamiento y diagnóstico de patologías, incluyendo aplicaciones de cirugía. Entre sus ventajas frente a técnicas que emplean radiaciones en otras bandas del espectro electromagnético u ondas acústicas, se encuentran su carácter no ionizante, no invasivo o mínimamente invasivo, la capacidad de localización precisa y la ausencia de contacto. Una de las técnicas diagnósticas más relevantes utiliza el fenómeno de la fluorescencia aplicada al ámbito biomédico. La fluorescencia es un fenómeno producido por la interacción entre un material y la radiación óptica, de tal forma que es capaz de reemitir radiación a longitudes de onda distintas, habitualmente superiores. Las características diagnósticas dependen fuertemente del tipo de fluoróforo empleado, que debe también cumplir restricciones de biocompatibilidad para su aplicabilidad biomédica. Este trabajo se focaliza en dos fluoróforos aprobados para uso clínico: azul de metileno y verde de indocianina. El objetivo consiste en analizar experimentalmente las características espectrales, fundamentalmente de excitación, lo que resulta imprescindible para su uso eficiente en la práctica clínica. Se analiza esta dependencia espectral con diferentes disolventes y a diferentes concentraciones. De esta forma es posible conocer los rangos de longitudes de onda óptimos para su aplicación clínica diagnóstica.Este trabajo ha sido parcialmente financiado por los proyectos del Plan Nacional de I+D+i “Nuevas fases activas en nano-óxidos de metales de transición y tierras raras estabilizadas a alta presión” (MAT2015-69508-P), y Acción Estratégica en Salud ”Electroencefalografía intracortical en pacientes con daño cerebral agudo” (PI17/00156), cofinanciados con fondos FEDER, y por la Fundación San Cándido
    corecore