2,204 research outputs found
INTERANNUAL VARIABILITY OF MIXED LAYER DYNAMICS IN THE ECUADORIAN OCEAN
Long time series spanning up to 22 years of monthly CTD profiles are used to examine upper water column ocean temperature interannual variability near the Ecuador coastline along the equator. The sampling program instituted by Ecuador’s National Institute of Oceanography of the Navy (INOCAR) began in 1992 occupying two stations about 8 nm from the coast, and then expanding to an additional 3 stations in 2004 by Ecuador’s National Fisheries Institute (INP) and National Institute of Meteorology and Hydrology (INAMHI). The stations are located near 80-81° W and extend from 2° S to 1° N. Climatological (seasonal) signals are removed from the data to focus on the interannual variability. Characterizations of the anomaly time series include the 20°C isotherm depth, mixed layer depth (greater than 5 m depth), heat content (above 100 m), and an EOF decomposition of the temperature profile data set. The data show marked interannual variations with distinct characteristics associated with ENSO indices that delineate periods of El Niño, La Niña, and “normal” conditions. Heat content and the 20°C isotherm depth are both largest during El Niño periods, and weakest during La Niña periods. Mixed layer depths are largely invariant during the various periods, likely due to the dependence of the characterization on details of individual temperature profile. The first mode EOF decomposition of the anomaly long record coastal station data represents bulk variations (71%) of the thermocline depth, and has temporal variability coupled (R = 0.65) to ENSO 3.4 and 1+2 indices. Coastal observations are compared with temperature observations obtained over the same time period from the offshore TAO/Triton buoys located along 95° W from 2° S to 2° N, to the west of the Galápagos Islands outside the geologic delineations of the Ecuadorian Sea. The EOF decomposition of TAO buoy anomaly time series shows similar spatial EOF structure, with the first mode representing bulk changes to the thermocline (about 71% of the variance). The first mode EOF amplitude time series from coastal and TAO station decomposition is correlated (R = 0.86), showing that the dominant variability of the upper water column thermal structure near the coast is coupled to variations along the equator and seaward of the Galápagos Islands. Comparisons of wind fields derived from ECMWF reanalysis in the regions shows that upwelling favorable winds to the north (in the Colombian basin) and to the south (along the coast of Perú) but away from the equator (where earth rotation impacts are minimal), produces a surface convergence at the equator close to shore that has variations that are strongly correlated with ENSO indices. The surface convergences are stronger during ENSO periods, and result in an increase in upper water column heating synchronous with the larger-scale ENSO variability
Simulación de un derrame de hidrocarburos en el puerto pesquero de santa rosa del canton salinas
Muchas naciones, que toman decisiones respecto al uso de energía, invierten mucho tiempo revisando las regulaciones que afectan la extracción, transportación, y consumo de petróleo. Estas políticas requieren balancear consideraciones económicas con las consecuencias ambientales del uso de petróleo. Como ha sido reconocido por algún tiempo, el petróleo puede presentar un riesgo significante para la vida marina, aún una pequeña cantidad liberada puede representar un impacto severo, sin embargo es una necesidad en nuestra sociedad industrial, y mantiene nuestro estilo de vida.
Nuevas estimaciones indican que el petróleo vertido en el medio ambiente marino puede ser menor de lo que antes se pensaba. Se piensa que esto refleja, en parte, los avances en la última década en el transporte marítimo de petróleo y gas, y las técnicas de producción. Además de que las medidas de prevención impuestas, uno de los factores más importantes para la elaboración de planes de Contingencia para derrames, están proveyendo los beneficios esperados3. Sin embargo, es necesario continuar con la simulación de la dinámica de derrames para reducir el riesgo de derrames de petróleo, y respaldar la introducción de nuevas legislaciones y códigos de operación. Los modelos numéricos de simulación son una de las herramientas principales, que hacen que los trabajos de prevención sean más precisos. El modelaje en este caso, ha tenido grandes avances durante los últimos años, resultando en una gran cantidad de programas computarizados comerciales que permiten la simulación de derrame de hidrocarburos. Para su ejecución se requiere de las características del derrame y las condiciones meteorológicas durante y las horas después del derrame, entre otras. Como resultado, el modelo ofrece una serie de datos relacionados a la trayectoria del derrame, el tiempo de impacto mínimo, el punto de impacto y la fracción evaporada, emulsionada y dispersada, al igual que la cantidad remanente de hidrocarburo que impactará la costa.
El objetivo general de esta tesis es simular un derrame de hidrocarburo en el Puerto de Santa Rosa, Bahía de Libertad, en distintas condiciones meteorológicas y oceanográficas, en el momento del derrame y las siguientes horas.
Los objetivos específicos son:
1. Comparar distintos modelos de simulación computarizada de derrame de hidrocarburos en océano abierto.
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2. Escoger el modelo más apropiado para simular el derrame de un hidrocarburo en el puerto de Santa Rosa, en la Bahía de Libertad, según los criterios de trayectoria del derrame más probable, y, la variación de las propiedades físicas y químicas de la mezcla de hidrocarburo.
3. Simular el movimiento de una mancha de hidrocarburo dadas distintas condiciones meteorológicas en la zona de estudio
Caracterización hidroquímica preliminar del acuífero Niebla-Posadas o Mioceno transgresivo de base en el tramo de la MASb de Guillena-Cantillana (provincia de Sevilla)
El objetivo del presente trabajo es contribuir a la caracterización hidroquímica preliminar de este sector del acuífero. Para ello, se han recogido y analizado un total de 90 muestras de agua subterránea, provenientes de sondeos, entre septiembre de 2020 y junio de 2021. Los análisis realizados incluyen la determinación de la alcalinidad total (HCO3- y CO32-) y de la concentración de iones mayoritarios (Cl-, SO42-, Na+, Ca2+, Mg2+, NO3-) y algunos minoritarios (Br-, K+, NH4+ y Li+).
Los resultados preliminares muestran una composición química y mineralización muy diversa, que varía desde facies bicarbonatadas cálcicas, en la zona libre, a cloruradas sódicas en el tramo confinado, pasando por facies mixtas sin un predominio claro de algún ion. De igual forma, la conductividad eléctrica del agua aumenta en el sentido del flujo subterráneo (de N a S), entre 400 y 1500 µS/cm. Las concentraciones de NO3‐ determinadas alcanzan valores superiores a 100 mg/l en el área de recarga, provocados por la elevada presión agrícola, y disminuyen hasta valores por debajo del límite de detección en la zona confinada. Esta atenuación gradual coincide con un aumento en el contenido de NH4+ y NO2-. El patrón de distribución espacial descrito parece estar muy influenciado por la geometría del acuífero. Las aguas de reserva de la zona confinada tendrían una tasa de renovación muy baja y, por tanto, un tiempo de residencia muy alto, lo que favorecería la disolución de minerales y la incorporación de iones al agua poco abundantes en el medio, como es el caso de Na+ y K+. Además, la variación en la concentración de las especies químicas del nitrógeno podría indicar la existencia de reacciones redox en el acuífero, aunque ello deberá ser comprobado mediante determinaciones isotópicas.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec
Learning contract, co-operative and flipped learning as useful tools for studying metabolism
Es el Abstract de una comunicación a un congreso internacional sobre educaciónUndergraduate students in Biology identify Metabolic Biochemistry as a particularly difficult subject. This is due to the fact that students need to interconnect properly all the contents of its syllabus throughout their study of the subject in order to get a global insight of the complex regulatory features controlling metabolic pathways within the metabolic network under different physiologic and pathologic conditions, as well as metabolism as a whole. Due to these objective difficulties, a high percentage of our students face the study of this subject as a very hard task beyond their forces and capacities. This perception leads to high rates of premature dropout. In previous years, less than 40% of all the registered students attended the examinations of Metabolic Biochemistry (a subject in the second year of the Degree of Biology at our University). Even worse, less than 25% of our students passed the exams.
From the academic year 2015/16 on, we are developing innovative teaching projects (PIE15-163 and PIE17-145, funded by University of Malaga) aimed to increase our student loyalty to the subject (and hence to increase their attendance to exams) and to help them to learn more effectively metabolism and its regulation. These innovative teaching projects are based on the use of several powerful tools: a learning contract and problem-based learning within the framework of group tasks promoting an actual collaborative learning in a flipped classroom.
The present communication will show the implementation of the PIE15-163 and PIE17-145 projects and some results obtained from them.This work was supported by Malaga University funds granted to the educational innovation project PIE17-145. The attendance to the END2018 International Conference on Education and New Developments (June 2018, Budapest, Hungary) has received a grant from "I Plan Propio Integral de Docencia. Universidad de Málaga"]
Sensitivity of bile acid transport by organic anion-transporting polypeptides to intracellular pH
AbstractWe investigated the influence of intracellular pH (pHi) on [14C]-glycocholate (GC) uptake by human hepatoblastoma HepG2 cells that express sodium-independent (mainly OATP-A and OATP-8), but not sodium-dependent, GC transporters. Replacement of extracellular sodium by choline (Chol) stimulated GC uptake but did not affect GC efflux from loaded cells. Amiloride or NaCl replacement by tetraethylammonium chloride (TeACl) or sucrose also increased GC uptake. All stimulating circumstances decreased pHi. By contrast, adding to the medium ammonium or imidazole, which increased pHi, had no effect on GC uptake. In Chinese hamster ovary (CHO) cells expressing rat Oatp1, acidification of pHi had the opposite effect on GC uptake, that is, this was reduced. Changes in extracellular pH (pHo) between 7.40 and 7.00 had no effect on GC uptake at pHi 7.30 or 7.45 when pHo<pHi. However, GC uptake was inhibited at pHo 7.40 and 7.80 when pHo>pHi. Inhibition was not proportional to the pHo−pHi difference. Intracellular acidification decreased Vmax, but had no effect on Km. In sum, sodium-independent GC transport can be affected by intracellular acidification, possibly due both to modifications in the driving forces and to the particular response to protonation of carrier proteins involved in this process
Evaluating the efficacy of the digital commons for scaling data-driven learning
This chapter presents the open-source FLAX project (Flexible Language Acquisition, flax.nzdl.org), an automated digital library scheme, which has developed and tested an extraction method that identifies typical lexico-grammatical features of any word or phrase in a corpus for data-driven learning. Here in this study, FLAX will be described and discussed in relation to the reuse of openly licensed content available in the digital commons. Typically, the digital commons involves the creation and distribution of informational resources and technologies that have been designed to stay in the digital commons using various open licenses, including the GNU Public License and the Creative Commons suite of licenses (Wikipedia, 2016; see also the chapter by Stranger-Johannessen, this volume). One of the most widely used informational resources developed by and for the digital commons is Wikipedia. In response to the growing digital commons, we will provide insights into design considerations for the reuse of transcribed video lectures from Massive Open Online Courses (MOOCs) that have been licensed with Creative Commons as Open Educational Resources (OERs). We will demonstrate how OERs can be remixed with open corpora and tools in the FLAX system to support English for Specific Academic Purposes (ESAP) in classroom-based language education contexts
A recurrent translocation, t(3;11)(q21;q13), found in two distinct cases of acute myeloid leukemia
We report two cases of acute myeloid leukemia (M1 and M5B subtypes) with a similar translocation, t(3;11)(q21;q13). We discuss the involvement of these breakpoints in acute leukemia and their putative clinical implications
A variant t(14;17) in acute promyelocytic leukemia. Positive response to retinoic acid treatment
We present a case of acute promyelocytic leukemia (APL) carrying an atypical translocation involving chromosomes 14 and 17. This translocation could be considered a variant of the APL-specific t(15;17). Positive response to retinoic acid treatment suggests molecular rearrangement of retinoic acid receptor alpha
Water temperature variability in the Coos Estuary and its potential link to eelgrass loss
20 pagesSubtidal water temperatures in estuaries influence where organisms can survive
and are determined by oceanic, atmospheric and riverine heat fluxes,modulated
by the distinct geometry and bathymetry of the system. Here, we use 14 years of
data from the Coos Estuary, in southwest Oregon, USA, to explore the impact of
anomalously warm oceanic and atmospheric conditions during 2014-2016 on
the estuary temperature. The arrival of a marine heatwave in September 2014
increased water temperature in the greater Pacific Northwest region until March
2015, and again from July to August 2015. Additionally, in 2014-2016, the
Equatorial Pacific showed increased temperatures due to El Niño events. In the
Coos Estuary, this warming was observed at all the water quality stations,
producing more than 100 days with temperatures at least 1.5°C warmer than
normal, and notably, a higher prevalence during Fall and Winter seasons. Larger
temperature variations occurred at shallower stations located further away from
the mouth of the estuary, changing the along-estuary temperature gradient and
potentially the advection of heat through the estuary. After the onset of these
increased temperatures, eelgrass declined sharply, but only in certain stations in
the shallow estuary South Slough and has not yet returned to long term average
values. As global temperatures continue rising due to climate change, increased
numbers ofmarine heatwaves and El Niño events are expected, leading to higher
temperature stress on the marine ecosystem within estuaries
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