On the onset of surface wind drift at short fetches as observed in a wind wave flume

International audienceOcean surface drift is of great relevance to properly model wind waves and specially the early stages of surfacewaves development and ocean-atmosphere fluxes during incipient wind events and storms. In particular, wavemodels are not so accurate predicting wave behaviour at short fetches, where wind drift onset might be veryimportant. The onset of surface drift induced by wind and waves is being studied through detailed laboratorymeasurements in a large wind-wave flume. Wind stress over the water surface, waves and surface drift aremeasured in the 40m long wind-wave tank at IRPHE, Marseille. While momentum fluxes are estimated directlythrough the eddy correlation method in a station about the middle of the tank, they provide reference informationto the corresponding surface drift onset recorded at rather short non-dimensional fetches. At each experimentalrun very low wind was on (about 1m/s) for a certain period and suddenly it was constantly accelerated to reachabout 13 m/s (as well as 8 and 5 m/s during different runs) in about 15 sec to as long as 600 sec. The windwas kept constant at that high speed for 2 to 10 min, and then suddenly and constantly decelerate to 0. Surfacedrift values were up to 0.5 cm/s for the highest wind while very distinctive shear was detected in the upper 1.5cm. Rather linear variation of surface drift was observed with depth. Evolution of the surface drift velocity isanalysed and onset behaviour is addressed with particular emphasis in accelerated winds. This work representsa RugDiSMar Project (CONACYT 155793) contribution. The support from ANUIES-ECOS M09-U01 project,CONACYT-187112 Estancia Sabática, and Institute Carnot, is greatly acknowledged

El coeficiente de arrastre sobre la superficie del mar como función de las características del oleaje

An analysis of the performance of parameterizations for the drag coefficient CD over the ocean is presented. The results were obtained by considering detailed observations from the recent IntOA experiment in which a co-existence of wind sea and swell provides characteristic mixed sea conditions in a wide range of wind speeds. Recent research has advanced our understanding of air-sea fluxes, proposing new functional forms for the drag coefficient, as well as applying wavelength scaling and determining dimensionally consistent expressions for the drag coefficient. Nevertheless, a detailed analysis of the influence of wind sea parameters confirms the need to include the sea state dependence on parameterizing CD for mixed sea conditions. It is also shown that better results are obtained when aerodynamic roughness is considered as a function of wave age and wave steepness, or equivalently if CD is expressed as a function of a characteristic peak frequency defined through the wave momentum spectrum.Se presenta un análisis del desempeño de algunas parametrizaciones del coeficiente de arrastre CD sobre la superficie del mar. Los resultados se obtienen a partir de observaciones detalladas durante el experimento IntOA. En ese experimento la existencia simultánea de oleaje generado localmente y oleaje que proviene de tormentas lejanas, nos brinda características únicas del estado del mar con constituyentes mixtas de oleaje en una gama amplia de velocidades del viento. A través de investigaciones recientes se ha avanzado en el conocimiento de los flujos entre el océano y la atmósfera, al proponer nuevas formas funcionales del coeficiente de arrastre, así como al utilizar expresiones dimensionalmente consistentes que se basan en escalas asociadas a la longitud de onda de las olas. Los resultados de este trabajo confirman la necesidad de incluir la influencia del estado del mar en las parametrizaciones del coeficiente de arrastre, especialmente bajo condiciones mixtas de oleaje. También se demuestra que se obtienen mejores resultados cuando la escala de rugosidad aerodinámica se considera como una función de la edad de la ola y de la pendiente del oleaje local o de forma equivalente, cuando CD se expresa como función de una frecuencia característica asociada al pico espectral que se determina mediante el espectro del momento del oleaje

On the early stages of wind-wave generation under accelerated wind conditions

International audienceWhen wind starts to blow, a momentum transfer initiates through the air-water interface generating ocean wave. This transfer is usually characterized in terms of the drag coefficient, CD, but its dependency with wind speed still presents remarkable scatter in the experimental studies. Besides, Babanin and Makin (2008) found that gustiness were responsible to the most distant outliers in drag coefficient values. Also, several studies showed the influence of the sea state and wave age in the roughness and drag coefficient behavior (Smith et al. 1992; Donelan et al. 1993; Drennan 2003). Most of the past studies of wind-waves generation considered uniform and stationary wind speeds. However, in open field it is common to have conditions of wind blowing with a certain acceleration before the constant wind condition is reached. In order to study the early stages of the generation of waves under accelerated wind conditions, a total of five experiments with a characteristic wind speed acceleration were conducted in a large wind-wave facility at the Institut Pytheas (Marseille-France). Momentum fluxes were estimated from hot wire anemometry and, the free surface displacement was measured along the channel tank by resistance and capacitance wire probes. High resolution wind speed and water elevation measurements were acquired at a high resolution rate. During experiments the wind speed was increased with a constant acceleration over time, reaching a constant maximum intensity of 13 m/s. It was observed that during accelerated wind conditions, drag coefficient values depends on the degree of development of the flow regime in the air section and on wave field generation and evolution. The acceleration of wind speed has a direct influence on water surface roughness and water wave evolution in time and in space

Use of medications on the elderly

The elderly constitute a growing world population group, with more than 200 million people over 60 years of age. This fact has increased the detection of chronic-degenerative diseases, as well as the prescription and consumption of medicines. The elderly are particularly susceptible to adverse drug events or interactions with other drugs due to their physiological changes, genetic predisposition and environmental exposure. It becomes necessary to adapt the health systems with integral and multidisciplinary approaches suitable to this demographic change, as the knowledge about appropriate prescription, clinical pharmacology and medication use in the elderly has become essential. It has been shown that about two thirds of elderly patients receive inappropriate drug doses, and a substantial percentage of their hospital admissions are associated with potentially preventable toxic effects of drugs. To date, expert criteria, error detection tools and educational prescription plans have been developed by expert consensus for the safe use of drugs in the geriatric population. The objective of this study is a brief review of the principal physiological changes in an older adult, and summarize the contributions of the consensuses on prescription

Seasonal and interannual variability of satellite-derived chlorophyll pigment, surface height, and temperature off Baja California

Mean fields, seasonal cycles, and interannual variability are examined for fields of satellite-derived chlorophyll pigment concentrations (CHL), sea surface height (SSH), and sea surface temperature (SST) during 1997–2002. The analyses help to identify three dynamic regions: an upwelling zone next to the coast, the Ensenada Front in the north, and regions of repeated meanders and/or eddy variability west and southwest of Point Eugenia. High values of CHL are found in the upwelling zone, diminishing offshore. The exception is the area north of 31°N (the Ensenada Front), where higher CHL are found about 150 km offshore. South of 31°N, the long-term mean dynamic topography decreases next to the coast, creating isopleths of height parallel to the coastline, consistent with southward geostrophic flow. North of 31°N the mean flow is toward the east, consistent with the presence of the Ensenada Front. The mean SST reveals a more north-south gradient, reflecting latitudinal differences in surface heating due to solar radiation. Harmonic analyses and EOFs reveal the seasonal and interannual patterns, including the region of repeated eddy activity to the west and southwest of Point Eugenia. A maximum CHL occurs in spring in most of the inshore regions, reflecting the growth of phytoplankton in response to the seasonal maximum in upwelling-favorable winds. SST and SSH anomalies are negative in the coastal upwelling zone in spring, also consistent with a response to the seasonal maximum in upwelling. When the seasonal cycle is removed, the strongest signal in the EOF time series is the response to the strong 1997– 1998 El Niño, with a weaker signal representing La Niña (1998–1999) conditions. El Niño conditions consist of low chlorophyll, high SSH, and high SST, with opposite conditions during La Niña

Nutrient concentrations, in vitro digestibility and rumen fermentation of agro-industrial residues of Cannabis sativa L. as a potential forage source for ruminants

Este estudio tuvo como objetivo determinar la concentración de PC, EE, CNS, fibras, CFT, TC, CBD, THC, digestibilidad in vitro de materia seca y parámetros de fermentación ruminal de residuos agroindustriales de Cannabis sativa L. de dos procesos extractivos de cannabinoides, como fuente potencial de forraje en la alimentación de rumiantes. La flor de Cannabis sativa se expuso al proceso de extracción por prensado en frío (CPF) y extracción alcohólica (CEA); los residuos vegetativos obtenidos después de las extracciones se compararon con la flor cruda como testigo (FCC) utilizando un diseño completamente al azar y la prueba de Tukey para la comparación de medias. Los procesos extractivos disminuyeron el EE, CFT y cannabinoides (CBD y THC). En contraste, las fibras, CNS y digestibilidad, aumentaron después de los procesos extractivos en CPF y CEA. Del mismo modo, la degradabilidad  in vitro aumentó después  de ambos procesos  extractivos  por encima del 120 %, así como el período de latencia. Además, los protozoos aumentaron con CPF, pero no se observaron cambios en CEA. Asimismo, no se observaron cambios en las bacterias celulolíticas en CPF y CEA. Sin embargo, las bacterias totales se redujeron después de ambas extracciones. Además, el N-amoníaco en las fermentaciones ruminales disminuyó con CPF y CEA, mientras que los ácidos grasos volátiles totales aumentaron. Además, la producción de gas aumentó por encima del 75 % en CPF y CEA; sin embargo, no se observaron cambios en el período de latencia. Además, la producción de metano y CO2 aumentó por encima del 80 y 60 %, respectivamente, para CPF y CEA; estos aumentos se asocian positivamente con mejoras en las fermentaciones ruminales. En conclusión, el residuo agroindustrial de Cannabis sativa L. obtenido después de los procesos extractivos analizados puede surgir como una fuente potencial de forraje en la alimentación de rumiantes.This study aimed to determine the concentration of CP, EE, NSC, fibers, TPC, CT, CBD, THC, in vitro digestibility of dry matter and rumen fermentation parameters of agroindustrial residues of Cannabis sativa L. from two extractive processes of cannabinoids, as a potential source of forage in ruminants feeding. The flower of Cannabis sativa was exposed to cold-press extraction (CPC) and alcoholic extraction (AEC) process; vegetative residues obtained after extractions were compared to raw flower as a control (RFC) using a completely randomized design and Tukey’s test for means comparison. Extractive processes decreased EE, TPC and cannabinoids (CBD and THC). Otherwise, fibers, NSC and digestibility, increased after the extractive processes in CPC and AEC. Similarly, in vitro degradability increased after both extractive processes above 120 % as well as latency period. Additionally, protozoa increased with CPC but no changes were observed in AEC. Likewise, no changes were observed in cellulolytic bacteria in CPC and AEC. However, total bacteria were reduced after both extractions. Moreover, N-ammonia in ruminal fermentations decreased with CPC and AEC whereas total volatile fatty acids increased. In addition, gas production increased above 75 % in CPC and AEC; however, no changes were observed in latency period. Furthermore, methane and CO2 production increased above 80 and 60 %, respectively for CPC and AEC; these augmentations are positively associated with improvements in the ruminal fermentations. In conclusions, the agroindustrial residue of Cannabis sativa L. obtained after the analyzed extractive processes may arise as a potential forage source in ruminants feeding

Venoarterial Extracorporeal Membrane Oxygenation with or without Simultaneous Intra-Aortic Balloon Pump Support as a Direct Bridge to Heart Transplantation: Results from a Nationwide Spanish Registry

[Abstract] OBJECTIVES To investigate the potential clinical benefit of an intra-aortic balloon pump (IABP) in patients supported with venoarterial extracorporeal membrane oxygenation (VA-ECMO) as a bridge to heart transplantation (HT). METHODS We studied 169 patients who were listed for urgent HT under VA-ECMO support at 16 Spanish institutions from 2010 to 2015. The clinical outcomes of patients under simultaneous IABP support (n = 73) were compared to a control group of patients without IABP support (n = 96). RESULTS There were no statistically significant differences between the IABP and control groups with regard to the cumulative rates of transplantation (71.2% vs 81.2%, P = 0.17), death during VA-ECMO support (20.6% vs 14.6%, P = 0.31), transition to a different mechanical circulatory support device (5.5% vs 5.2%, P = 0.94) or weaning from VA-ECMO support due to recovery (2.7% vs 0%, P = 0.10). There was a higher incidence of bleeding events in the IABP group (45.2% vs 25%, P = 0.006; adjusted odds ratio 2.18, 95% confidence interval 1.02–4.67). In-hospital postoperative mortality after HT was 34.6% in the IABP group and 32.5% in the control group (P = 0.80). One-year survival after listing for urgent HT was 53.3% in the IABP group and 52.2% in the control group (log rank P = 0.75). Multivariate adjustment for potential confounders did not change this result (adjusted hazard ratio 0.94, 95% confidence interval 0.56–1.58). CONCLUSIONS In our study, simultaneous IABP therapy in transplant candidates under VA-ECMO support did not significantly reduce morbidity or mortality

Ocean monitoring, observation network and modelling of the Gulf of Mexico by CIGOM

The tragic accident of the Macondo platform operated by British Petroleum (BP) unleashed in 2010 one of the largest oil spills in history, lasting over three months, spilling nearly 500 million liters of oil in one of the most biodiverse ocean regions. This accident revealed the technological deficiencies for the control of a spill in deep waters of the hydrocarbon industry. Simultaneously it showed important gaps in knowledge to predict the propagation and fate of the large volumes of hydrocarbons at depth and on the surface ocean and, more importantly, on their impact on the great ecosystem of the Gulf of Mexico. The necessity to understand and predict the transport, fate and ecosystem-level impacts of large oil spills in the southern Gulf of Mexico, a key region for oil exploration and extraction, led policymakers, scientists, and industry representatives from PEMEX (the Mexican oil company) to jointly launch an ocean observation project (2015-22) aimed to provide a multi-layered environmental baseline, develop a modern monitoring and computational modeling capacity and promote scientific understanding of the marine environment throughout the Mexican Exclusive Economic Zone (EEZ). The initiative, led by the Research Consortium for the Gulf of Mexico (CIGoM), brought together more than 300 multidisciplinary researchers from more than a two dozen institutions in Mexico and abroad, including the Centre for Scientific Research and Higher Education of Ensenada (CICESE) as the leading institution, the National Autonomous University of Mexico (UNAM), the Centre for Research and Advanced Studies of the National Polytechnic Institute (CINVESTAV) in Mérida, the Autonomous University of Baja California (UABC), and the Centre for Engineering and Industrial Development (CIDESI). Financial support was provided by the National Council for Science and Technology and the Ministry of Energy Hydrocarbon Fund