10 research outputs found

    Characterization of Gelidium corneum's (Florideophyceae, Rhodophyta) vegetative propagation process under increasing levels of temperature and irradiance

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    Climate change is affecting Gelidium corneum (Hudson) J.V. Lamouroux fields in the Bay of Biscay by reducing its cover and biomass. Understanding those changes requires a good characterization of the responses of this species to different stressors, particularly the effects on key processes such as the vegetative propagation. Here, we aimed to characterize the interactive effect of temperature (15, 20 and 25◦C) and irradiance (5-10, 55-60 and 95-100 μmol*m2*s- 1) on two phases of the vegetative propagation process: the re-attachment capacity and the survival of re-attached fragments. The study findings revealed significant effects of both temperature and irradiance in the re-attachment capacity of the species, with higher rates of attachment registered at 20 ◦C and 5-10 μmol*m- 2*s-1 after 10, 20 and 30 days of culture. However, the interaction effects were not significant at any time interval. At higher or lower temperatures and increasing irradiances, the attachment capacity was reduced. On the other hand, irradiance was demonstrated to be the main factor controlling the survival of rhizoids. In fact, higher levels of irradiance generated severe damage on rhizoids, and thus, conditioned the development of new plants. According to this, it seems clear that the vegetative propagation process of this species is expected to become more vulnerable as both variables are expected to rise due to climate change. An increased vulnerability of this species may have several implications from an ecological and economic perspective, so we encourage to continue exploring the factors and processes controlling its distribution in order to adopt better management actions in the future.This work was funded by the National Plan for Research in Science and Technological Innovation from the Spanish Government 2017–2020 [grant number C3N-pro project PID2019-105503RB-I00] and co-funded by the European Regional Development’s funds. Samuel Sainz-Villegas and Begoña Sánchez-Astráin acknowledge the financial support received under predoctoral grants from the Spanish Ministry of Science, Innovation and Universities [grant numbers: FPU18/03573 and PRE2020-096255, respectively]. This work is part of the PhD project of Samuel Sainz-Villegas

    Predicting non-native seaweeds global distributions: The importance of tuning individual algorithms in ensembles to obtain biologically meaningful results

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    ABSTRACT: Modelling non-native marine species distributions is still a challenging activity. This study aims to predict the global distribution of five widespread introduced seaweed species by focusing on two mains aspects of the ensemble modeling process: (1) Does the enforcement of less complex models (in terms of number of predictors) help in obtaining better predictions? (2) What are the implications of tuning the configuration of individual algorithms in terms of ecological realism? Regarding the first aspect, two datasets with different number of predictors were created. Regarding the second aspect, four algorithms and three configurations were tested. Models were evaluated using common evaluation metrics (AUC, TSS, Boyce index and TSS-derived sensitivity) and ecological realism. Finally, a stepwise procedure for model selection was applied to build the ensembles. Models trained with the large predictor dataset generally performed better than models trained with the reduced dataset, but with some exceptions. Regarding algorithms and configurations, Random Forest (RF) and Generalized Boosting Models (GBM) scored the highest metric values in average, even though, RF response curves were the most unrealistic and non-smooth and GBM showed overfitting for some species. Generalized Linear Models (GLM) and MAXENT, despite their lower scores, fitted smoother curves (especially at intermediate complexity levels). Reliable and biologically meaningful predictions were achieved. Inspecting the number of predictors to include in final ensembles and the selection of algorithms and its complexity have been demonstrated to be crucial for this purpose. Additionally, we highlight the importance of combining quantitative (based on multiple evaluation metrics) and qualitative (based on ecological realism) methods for selecting optimal configurations.This work was funded by the National Plan for Research in Science and Technological Innovation from the Spanish Government 2017-2020 [grant number C3N-pro project PID2019-105503RB-I00] and co-funded by the European Regional Development’s funds. SS-V acknowledges financial support under a predoctoral grant from the Spanish Ministry of Education andVocational Training [grantnumber:FPU18/03573]. CH acknowledges the financial support from the Government of Cantabria through the Fénix Programme and under a postdoctoral grant from the University of Cantabria [grant number: POS-UC- 2020-07]. This work is part of the PhD project of SS-V

    Rainfall characteristics in León in 2016 and 2017

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    Ponencia presentada en: XXXV Jornadas Científicas de la AME y el XIX Encuentro Hispano Luso de Meteorología celebrado en León, del 5 al 7 de marzo de 2018.Nowadays, air pollution is one of the principal risk to human health and rain is the main sink of aerosol particles in the atmosphere, since it is the main process to mitigate pollution. Furthermore, the study of rainfall characteristics is crucial because it can provide information about present and future risks in an area, related to rain amount or intensity. In order to know the characteristics of the precipitation in the city of León, rain was sampled during 2016 and 2017 using a Laser Precipitation Monitor (LPM) of Thies Clima which registered drops between 0.125 and 8 mm in 22 channels. Furthermore, a Circulation Weather Types (CWTs) classification was carried out based on Lamb (1972), to identify the weather type related to a peculiar synoptic situation in days with rain. Focusing on rain characteristics in the city of León, 3.23·109 drops m-2 have fallen in 2016 with a mean size of 0.36±0.20 mm and 1.06·109 drops m-2 in 2017 with a mean size of 0.35±0.19 mm. The rain characteristic according to Lamb Weather Types during rain events will be analyzed.This work was partially supported by the Spanish Ministry of Economy and Competitiveness (Grant TEC2014-57821-R), the University of Leon (Programa Propio 2015/00054/001) and the AERORAIN project (Ministry of Economy and Competitiveness, Grant CGL2014-52556-R, ERDF co-financed)

    Tipos de tiempo y calidad del aire en tres estaciones de fondo del NW peninsular

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    Ponencia presentada en: XXXV Jornadas Científicas de la AME y el XIX Encuentro Hispano Luso de Meteorología celebrado en León, del 5 al 7 de marzo de 2018.La contaminación atmosférica se ha incrementado principalmente por el desarrollo de actividades industriales y económicas. Además, hay que tener en cuenta no sólo la contaminación atmosférica generada cerca de las fuentes, sino también la que se ha transportado hacia zonas alejadas, conocidas como regiones de fondo. En este trabajo se estudia la evolución de las concentraciones de los contaminantes atmosféricos en tres estaciones de fondo de la Península Ibérica y se buscan las posibles relaciones entre la concentración de contaminantes atmosféricos y las condiciones meteorológicas en dichas estaciones.Este trabajo ha sido parcialmente financiado por el Ministerio de Economía y Competitividad (TEC2014-57821-R), la Universidad de León (Programa Propio 2015/00054/001) y el proyecto AERORAIN (Ministerio de Economía y Competitividad, CGL2014-52556-R, cofinanciado con fondos FEDER)

    Influencia de los parámetros meteorológicos en la contaminación del aire en la ciudad de Santander

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    Ponencia presentada en: XXXV Jornadas Científicas de la AME y el XIX Encuentro Hispano Luso de Meteorología celebrado en León, del 5 al 7 de marzo de 2018.Con este trabajo se pretende calcular, para cada tipo de tiempo, la concentración media de contaminantes presentes en la atmósfera y buscar las correlaciones significativas entre la concentración de dichos contaminantes y algunos parámetros meteorológicos en la ciudad de Santander. Para analizar las posibles diferencias significativas, se han aplicado tests no paramétricos.Este trabajo ha sido parcialmente financiado por el Ministerio de Economía y Competitividad (TEC2014-57821-R), la Universidad de León (Programa Propio 2015/00054/001) y el proyecto AERORAIN (Ministerio de Economía y Competitividad, CGL2014-52556-R, cofinanciado con fondos FEDER)

    Inter-Rater Variability in the Evaluation of Lung Ultrasound in Videos Acquired from COVID-19 Patients

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    12 páginas, 7 figuras, 1 tablaLung ultrasound (LUS) allows for the detection of a series of manifestations of COVID-19, such as B-lines and consolidations. The objective of this work was to study the inter-rater reliability (IRR) when detecting signs associated with COVID-19 in the LUS, as well as the performance of the test in a longitudinal or transverse orientation. Thirty-three physicians with advanced experience in LUS independently evaluated ultrasound videos previously acquired using the ULTRACOV system on 20 patients with confirmed COVID-19. For each patient, 24 videos of 3 s were acquired (using 12 positions with the probe in longitudinal and transverse orientations). The physicians had no information about the patients or other previous evaluations. The score assigned to each acquisition followed the convention applied in previous studies. A substantial IRR was found in the cases of normal LUS (κ = 0.74), with only a fair IRR for the presence of individual B-lines (κ = 0.36) and for confluent B-lines occupying 50% (κ = 0.50). No statistically significant differences between the longitudinal and transverse scans were found. The IRR for LUS of COVID-19 patients may benefit from more standardized clinical protocols.This research was partially funded by CDTI (Spanish acronym: Centre for Industrial Tech- nological Development), funding number COI-20201153. Partially supported by the Google Cloud Research Credits program with the funding number GCP19980904, by the project RTI2018-099118- A-I00 founded by MCIU/AEI/FEDER UE and by the European Commission–NextGenerationEU, through CSIC’s Global Health Platform (PTI Salud Global)

    Connection between Weather Types and Air Pollution Levels: A 19-Year Study in Nine EMEP Stations in Spain

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    This study focuses on the analysis of the distribution, both spatial and temporal, of the PM10 (particulate matter with a diameter of 10 µm or less) concentrations recorded in nine EMEP (European Monitoring and Evaluation Programme) background stations distributed throughout mainland Spain between 2001 and 2019. A study of hierarchical clusters was used to classify the stations into three main groups with similarities in yearly concentrations: GC (coastal location), GNC (north–central location), and GSE (southeastern location). The highest PM10 concentrations were registered in summer. Annual evolution showed statistically significant decreasing trends in PM10 concentration in all the stations covering a range from −0.21 to −0.50 µg m−3/year for Barcarrota and Víznar, respectively. Through the Lamb classification, the weather types were defined during the study period, and those associated with high levels of pollution were identified. Finally, the values exceeding the limits established by the legislation were analyzed for every station assessed in the study

    Connection between Weather Types and Air Pollution Levels: A 19-Year Study in Nine EMEP Stations in Spain

    Get PDF
    This study focuses on the analysis of the distribution, both spatial and temporal, of the PM10 (particulate matter with a diameter of 10 µm or less) concentrations recorded in nine EMEP (European Monitoring and Evaluation Programme) background stations distributed throughout mainland Spain between 2001 and 2019. A study of hierarchical clusters was used to classify the stations into three main groups with similarities in yearly concentrations: GC (coastal location), GNC (north–central location), and GSE (southeastern location). The highest PM10 concentrations were registered in summer. Annual evolution showed statistically significant decreasing trends in PM10 concentration in all the stations covering a range from −0.21 to −0.50 µg m−3/year for Barcarrota and Víznar, respectively. Through the Lamb classification, the weather types were defined during the study period, and those associated with high levels of pollution were identified. Finally, the values exceeding the limits established by the legislation were analyzed for every station assessed in the study

    Inter-Rater Variability in the Evaluation of Lung Ultrasound in Videos Acquired from COVID-19 Patients

    No full text
    Lung ultrasound (LUS) allows for the detection of a series of manifestations of COVID-19, such as B-lines and consolidations. The objective of this work was to study the inter-rater reliability (IRR) when detecting signs associated with COVID-19 in the LUS, as well as the performance of the test in a longitudinal or transverse orientation. Thirty-three physicians with advanced experience in LUS independently evaluated ultrasound videos previously acquired using the ULTRACOV system on 20 patients with confirmed COVID-19. For each patient, 24 videos of 3 s were acquired (using 12 positions with the probe in longitudinal and transverse orientations). The physicians had no information about the patients or other previous evaluations. The score assigned to each acquisition followed the convention applied in previous studies. A substantial IRR was found in the cases of normal LUS (κ = 0.74), with only a fair IRR for the presence of individual B-lines (κ = 0.36) and for confluent B-lines occupying < 50% (κ = 0.26) and a moderate IRR in consolidations and B-lines > 50% (κ = 0.50). No statistically significant differences between the longitudinal and transverse scans were found. The IRR for LUS of COVID-19 patients may benefit from more standardized clinical protocols
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