55 research outputs found

    Surface circulation in the Alborn Sea (western Mediterranean) inferred from remotely sensed data

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    In this study, for the first time at regional scale, the combined use of remote sensing data (altimetry and sea surface temperature records) provides a description of the persistent, recurrent and transient circulation regimes of the Alborn Sea circulation. The analysis of 936 altimeter-derived weekly absolute dynamic topography (ADT) and surface geostrophic current maps for 1993-2010 reveals the presence of a dominant annual signal and of two interannual modes of variability. The winter-spring phase is characterized by two stable gyral scale features; the well-known Western Anticyclonic Gyre within the western area and the Central Cyclonic Gyre, a new structure not identified in former studies, occupying the central and eastern parts of the Alborn Sea. A double anticyclonic gyre regime constitutes the stable circulation system of the summer-autumn period when the Eastern Anticyclonic Gyre is formed within the eastern Alborn basin. In this case, the Central Cyclonic Gyre is narrower and located closer to the Western Anticyclonic Gyre. They represent two stable states of the system, robust at the decadal time scale, whereas transient changes reflect perturbations on these stable states and are mainly observed at an interannual scale. The circulation variability and the gyral features development may be dynamically linked to the corresponding changes of the Gibraltar transport rates. © 2012. American Geophysical Union. All Rights Reserved.Partial support from EU funded projects MyOcean and PERSEUS is gratefully acknowledgedPeer Reviewe

    Toward the predictability of meteotsunamis in the Balearic Sea using regional nested atmosphere and ocean models

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    Meteotsunamis are oceanic waves that possess tsunami‐like characteristics but are meteorological in origin. In the western Mediterranean, travelling atmospheric pressure oscillations generate these long oceanic surface waves that can become amplified and produce strong seiche oscillations inside harbors. We analyze a June 2006 meteotsunami event in Ciutadella harbor (Menorca Island, Spain), studying numerically the phenomenon during its full life cycle, from the early atmospheric stages to the atmosphere‐ocean resonant phase and the final highly amplified harbor oscillation. The Weather Research Forecast (WRF) atmospheric model adequately reproduces the development of a convective nucleus and also reproduces the induced atmospheric pressure oscillations moving at a speed of 27 m/s. The oceanic response is studied using the Regional Ocean Modeling System (ROMS), forced by the WRF pressure field. It shows an inverse barometer wave front in the open ocean progressively amplified through resonant interactions in the different shelf and coastal regions. The predictive capability of this new WRF/ROMS modeling approach is then discussed.This work has been partially funded by COOL (CTM2006‐12072/MAR), ECOOP (CTM2007‐31006E) and SOCIB Modeling Facility whose support is gratefully acknowledged

    Coupled atmosphere-ocean-wave simulations of a storm event over the Gulf of Lion and Balearic Sea

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    Author Posting. © American Geophysical Union, 2012. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research 117 (2012): C09019, doi:10.1029/2012JC007924.The coastal areas of the North-Western Mediterranean Sea are one of the most challenging places for ocean forecasting. This region is exposed to severe storms events that are of short duration. During these events, significant air-sea interactions, strong winds and large sea-state can have catastrophic consequences in the coastal areas. To investigate these air-sea interactions and the oceanic response to such events, we implemented the Coupled Ocean-Atmosphere-Wave-Sediment Transport Modeling System simulating a severe storm in the Mediterranean Sea that occurred in May 2010. During this event, wind speed reached up to 25 m.s−1 inducing significant sea surface cooling (up to 2°C) over the Gulf of Lion (GoL) and along the storm track, and generating surface waves with a significant height of 6 m. It is shown that the event, associated with a cyclogenesis between the Balearic Islands and the GoL, is relatively well reproduced by the coupled system. A surface heat budget analysis showed that ocean vertical mixing was a major contributor to the cooling tendency along the storm track and in the GoL where turbulent heat fluxes also played an important role. Sensitivity experiments on the ocean-atmosphere coupling suggested that the coupled system is sensitive to the momentum flux parameterization as well as air-sea and air-wave coupling. Comparisons with available atmospheric and oceanic observations showed that the use of the fully coupled system provides the most skillful simulation, illustrating the benefit of using a fully coupled ocean-atmosphere–wave model for the assessment of these storm events.This work has been partially supported by MyOcean2 EU funded project 283367 whose support is gratefully acknowledged.2013-03-1

    Antifungal Activity of the Human Uterine Cervical Stem Cells Conditioned Medium (hUCESC-CM) Against Candida albicans and Other Medically Relevant Species of Candida

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    Background: Candidiasis is a major cause of human morbidity and mortality. Human uterine cervical stem cells conditioned medium (hUCESC-CM) is obtained from stromal stem cells of the cervical transformation zone, which are in permanent contact with a wide array of potential vaginal pathogens. In previous reports we have found that hUCESC-CM has antitumor and antibacterial potential. Since Candida is the most prevalent yeast in the human vagina, it seems plausible that hUCESC-CM might also show activity against it. Methods: In a preliminary step, to evaluate if hUCESC-CM showed any activity at all on Candida growth, in vitro activities of hUCESC-CM against fluconazole-susceptible reference strains of Candida albicans, Candida glabrata, Candida krusei, and Candida parapsilosis were studied with a microdilution method on RPMI 1640, using the BioScreen C microbiological incubator. Each measurement was repeated five times. The same methodology was used subsequently on fluconazole-susceptible and fluconazole-resistant Candida isolates from blood and vagina of those species corresponding to the reference strains of Candida against which activity had been detected in the previous study. Moreover, two fluconazole-resistant clinical isolates of Candida auris from blood and urine were also included. Findings: In vitro inhibitory activity of hUCESC-CM ranged from 57.5 to 96.6% growth-reduction against fluconazole-susceptible reference strains of Candida albicans, Candida glabrata, and Candida parapsilosis. hUCESC-CM also reduced the growth of all fluconazole-susceptible tested vaginal isolates by more than 50%. For fluconazole-resistant isolates, growth-reduction was higher than 67% for Candida albicans, regardless of its origin (vagina or blood). The isolate of Candida auris from urine with a MIC > 128 μ/ml for fluconazole was also significantly inhibited. However, hUCESC-CM was almost inactive against any of the fluconazole-resistant blood isolates of Candida glabrata, Candida parapsilosis, and Candida auris tested. Interpretation: This is the first report about the growth-inhibiting properties of conditioned medium from human stromal stem cells against different species of Candida. Antifungal activity of stromal stem cells depends on their site of origin, being most effective against Candida species most prevalent at that particular location. If confirmed in further studies, these findings might result in a completely new therapeutic approach against superficial and invasive candidiasisCM-A was a recipient of a grant from Fundación Once (Oportunidad al Talento). EM, CM-A, EE, and GQ have received grant support from Consejería de Educación, Universidades e Investigación (GIC15 IT-990-16), Fondo de Investigación Sanitaria (FIS PI11/00203), and UPV/EHU (UFI 11/25)S

    Antifungal Activity of the Human Uterine Cervical Stem Cells Conditioned Medium (hUCESC-CM) Against Candida albicans and Other Medically Relevant Species of Candida

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    Background: Candidiasis is a major cause of human morbidity and mortality. Human uterine cervical stem cells conditioned medium (hUCESC-CM) is obtained from stromal stem cells of the cervical transformation zone, which are in permanent contact with a wide array of potential vaginal pathogens. In previous reports we have found that hUCESC-CM has antitumor and antibacterial potential. Since Candida is the most prevalent yeast in the human vagina, it seems plausible that hUCESC-CM might also show activity against it.Methods: In a preliminary step, to evaluate if hUCESC-CM showed any activity at all on Candida growth, in vitro activities of hUCESC-CM against fluconazole-susceptible reference strains of Candida albicans, Candida glabrata, Candida krusei, and Candida parapsilosis were studied with a microdilution method on RPMI 1640, using the BioScreen C microbiological incubator. Each measurement was repeated five times. The same methodology was used subsequently on fluconazole-susceptible and fluconazole-resistant Candida isolates from blood and vagina of those species corresponding to the reference strains of Candida against which activity had been detected in the previous study. Moreover, two fluconazole-resistant clinical isolates of Candida auris from blood and urine were also included.Findings:In vitro inhibitory activity of hUCESC-CM ranged from 57.5 to 96.6% growth-reduction against fluconazole-susceptible reference strains of Candida albicans, Candida glabrata, and Candida parapsilosis. hUCESC-CM also reduced the growth of all fluconazole-susceptible tested vaginal isolates by more than 50%. For fluconazole-resistant isolates, growth-reduction was higher than 67% for Candida albicans, regardless of its origin (vagina or blood). The isolate of Candida auris from urine with a MIC > 128 μ/ml for fluconazole was also significantly inhibited. However, hUCESC-CM was almost inactive against any of the fluconazole-resistant blood isolates of Candida glabrata, Candida parapsilosis, and Candida auris tested.Interpretation: This is the first report about the growth-inhibiting properties of conditioned medium from human stromal stem cells against different species of Candida. Antifungal activity of stromal stem cells depends on their site of origin, being most effective against Candida species most prevalent at that particular location. If confirmed in further studies, these findings might result in a completely new therapeutic approach against superficial and invasive candidiasis

    Aberrant DNA methylation in non-small cell lung cancer-associated fibroblasts

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    Epigenetic changes through altered DNA methylation have been implicated in critical aspects of tumor progression, and have been extensively studied in a variety of cancer types. In contrast, our current knowledge of the aberrant genomic DNA methylation in tumor-associated fibroblasts (TAFs) or other stromal cells that act as critical coconspirators of tumor progression is very scarce. To address this gap of knowledge, we conducted genome-wide DNA methylation profiling on lung TAFs and paired control fibroblasts (CFs) from non-small cell lung cancer patients using the HumanMethylation450 microarray. We found widespread DNA hypomethylation concomitant with focal gain of DNA methylation in TAFs compared to CFs. The aberrant DNA methylation landscape of TAFs had a global impact on gene expression and a selective impact on the TGF-β pathway. The latter included promoter hypermethylation-associated SMAD3 silencing, which was associated with hyperresponsiveness to exogenous TGF-β1 in terms of contractility and extracellular matrix deposition. In turn, activation of CFs with exogenous TGF-β1 partially mimicked the epigenetic alterations observed in TAFs, suggesting that TGF-β1 may be necessary but not sufficient to elicit such alterations. Moreover, integrated pathway-enrichment analyses of the DNA methylation alterations revealed that a fraction of TAFs may be bone marrow-derived fibrocytes. Finally, survival analyses using DNA methylation and gene expression datasets identified aberrant DNA methylation on the EDARADD promoter sequence as a prognostic factor in non-small cell lung cancer patients. Our findings shed light on the unique origin and molecular alterations underlying the aberrant phenotype of lung TAFs, and identify a stromal biomarker with potential clinical relevance

    Automatic detection and classification of coastal Mediterranean fish from underwater images: Good practices for robust training

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    11 pages, 3 figures, 5 tables, supplementary material https://www.frontiersin.org/articles/10.3389/fmars.2023.1151758/full#supplementary-material.-- Data availability statement: The datasets presented in this study can be found in online repositories. The names of the repository/repositories and accession number(s) can be found in the article/Supplementary MaterialFurther investigation is needed to improve the identification and classification of fish in underwater images using artificial intelligence, specifically deep learning. Questions that need to be explored include the importance of using diverse backgrounds, the effect of (not) labeling small fish on precision, the number of images needed for successful classification, and whether they should be randomly selected. To address these questions, a new labeled dataset was created with over 18,400 recorded Mediterranean fish from 20 species from over 1,600 underwater images with different backgrounds. Two state-of-the-art object detectors/classifiers, YOLOv5m and Faster RCNN, were compared for the detection of the ‘fish’ category in different datasets. YOLOv5m performed better and was thus selected for classifying an increasing number of species in six combinations of labeled datasets varying in background types, balanced or unbalanced number of fishes per background, number of labeled fish, and quality of labeling. Results showed that i) it is cost-efficient to work with a reduced labeled set (a few hundred labeled objects per category) if images are carefully selected, ii) the usefulness of the trained model for classifying unseen datasets improves with the use of different backgrounds in the training dataset, and iii) avoiding training with low-quality labels (e.g., small relative size or incomplete silhouettes) yields better classification metrics. These results and dataset will help select and label images in the most effective way to improve the use of deep learning in studying underwater organismsProject DEEP-ECOMAR. 10.13039/100018685-Comunitat Autonoma de les Illes Balears through the Direcció General de Política Universitària i Recerca with funds from the Tourist Stay Tax law ITS 2017-006 (Grant Number: PRD2018/26). [...] The present research was carried out within the framework of the activities of the Spanish Government through the “María de Maeztu Centre of Excellence” accreditation to IMEDEA (CSIC-UIB) (CEX2021-001198-M) and the “Severo Ochoa Centre Excellence” accreditation to ICM-CSIC (CEX2019-000928-S) and the Research Unit Tecnoterra (ICM-CSIC/UPC)Peer reviewe

    Scientific management of Mediterranean coastal zone: A hybrid ocean forecasting system for oil spill and search and rescue operations

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    Jordi, Antoni et al.The oil spill from Prestige tanker showed the importance of scientifically based protocols to minimize the impacts on the environment. In this work, we describe a new forecasting system to predict oil spill trajectories and their potential impacts on the coastal zone. The system is formed of three main interconnected modules that address different capabilities: (1) an operational circulation sub-system that includes nested models at different scales, data collection with near-real time assimilation, new tools for initialization or assimilation based on genetic algorithms and feature-oriented strategic sampling; (2) an oil spill coastal sub-system that allows simulation of the trajectories and fate of spilled oil together with evaluation of coastal zone vulnerability using environmental sensitivity indexes; (3) a risk management sub-system for decision support based on GIS technology. The system is applied to the Mediterranean Sea where surface currents are highly variable in space and time, and interactions between local, sub-basin and basin scale increase the non-linear interactions effects which need to be adequately resolved at each one of the intervening scales. Besides the Mediterranean Sea is a complex reduced scale ocean representing a real scientific and technological challenge for operational oceanography and particularly for oil spill response and search and rescue operations. © 2005 Elsevier Ltd. All rights reserved.Peer Reviewe

    SOCIB: the impact of new marine infrastructures in understanding and forecasting the coastal oceans: some examples from the Balearic Islands in the Mediterranean Sea

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    New monitoring technologies are being progressively implemented in coastal ocean observatories. As an example, gliders allow high resolution sampling, showing the existence of new features, such as submesoscale eddies with intense vertical motions that significantly affect upper ocean biogeochemical exchanges, an issue of worldwide relevance in a climate change context. SOCIB, is one of such systems, a new facility of facilities (covering from the coast to the open sea, and including among others a nearshore beach monitoring facility, HF radar, gliders and AUV’s, moorings, satellite, drifters and ARGO profilers, modelling), a scientific and technological infrastructure which is providing free, open, quality controlled and timely streams of oceanographic and coastal data and also modelling services. SOCIB takes profit of the strategic position of the Balearic Island at the Atlantic/Mediterranean transition area, one of the ‘hot spots’ of biodiversity in the world’s oceans. As an example of on-going SOCIB operations, since January 2011 sustained glider operations are in place in the Ibiza and Mallorca channels. The data centre is the core of SOCIB. The data management system created for gliders is an example of the new informatics capabilities for real time definition of mission planning, including adaptive sampling and real time monitoring using a Web tool that allows quick visualization and download. This type of new infrastructures, combined with new technologies and careful scientific analysis will allow new ways of international cooperation leading to major science breakthroughs in the very near future and new ways of science based coastal and ocean management.Peer Reviewe
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