27 research outputs found

    Genetic characteristics influence the phenotype of marine macroalga Fucus vesiculosus (Phaeophyceae)

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    Intraspecific variation is an important component of heterogeneity in biological systems that can manifest at the genotypic and phenotypic level. This study investigates the influence of genetic characteristics on the phenotype of free-living Fucus vesiculosus using traditional morphological measures and microsatellite genotyping. Two sympatric morphotypes were observed to be significantly genetically and morphologically differentiated despite experiencing analogous local environmental conditions; indicating a genetic element to F. vesiculosus morphology. Additionally, the observed intraclonal variation established divergent morphology within some genets. This demonstrated that clonal lineages have the ability to alter morphological traits by either a plastic response or somatic mutations. We provide support for the potential occurrence of the Gigas effect (cellular/organ enlargement through genome duplication) in the Fucus genus, with polyploidization appearing to correlate with a general increase in the size of morphological features. Phenotypic traits, as designated by morphology within the study, of F. vesiculosus are partially controlled by the genetic characteristics of the thalli. This study suggests that largely asexually reproducing algal populations may have the potential to adapt to changing environmental conditions through genome changes or phenotypic plasticity.Peer reviewe

    Seasonal Variability in Benthic-Pelagic Coupling : Quantifying Organic Matter Inputs to the Seafloor and Benthic Macrofauna Using a Multi-Marker Approach

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    The exchange between the water column and the seafloor is a complex process, and is particularly intensive in the shallow waters of highly productive coastal areas, where the temporal variability in the inputs of pelagic organic matter will determine many aspects of the benthic community structure. However, few studies have focused on the seasonality of inputs of organic matter to the seafloor, and on the consequent dynamics and time scales of response of benthic consumers. We conducted a 1-year study where we repeatedly sampled multiple organic compounds traditionally used as markers to study the link between the pelagic organic matter inputs and the seafloor, and the potential response of benthic macrofauna to seasonal trends in phytoplankton biomass. We simultaneously quantified the particulate organic matter in the water column, the sinking material and different seafloor compartments, and analyzed it for pigments, organic carbon and nitrogen content, C/N ratio, and stable isotopes. Seafloor sediment was also analyzed for total lipids, and the dominant macrobenthic species for isotopic signatures. Results showed a major deposition of fresh organic matter during the spring bloom followed by more degraded organic matter inputs during the late summer bloom and even lower quality of the organic matter reaching the seafloor during winter. Strong positive relationships between water column and sedimentary pigments suggest that phytoplankton was the main source of carbon to the seafloor. The isotopic signatures of the dominant macrobenthic species suggest a fast response to the organic matter inputs from the water column. However, different species responded differently to the deposition of organic matter. Macoma balthica and Marenzelleria spp. fed on more reworked and degraded sedimentary material, while Monoporeia affinis showed a shift in the feeding habits according to its life stage, with adult individuals feeding on fresher material than juveniles did. Our study highlights the seasonal variability of the benthic-pelagic coupling and the utility of a multi-marker approach to follow the temporal inputs of organic matter from the water column to the seafloor and benthic organisms.Peer reviewe

    Interaction strength between different grazers and macroalgae mediated by ocean acidification over warming gradients

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    Since the past century, rising CO2 levels have led to global changes (ocean warming and acidification) with subsequent effects on marine ecosystems and organisms. Macroalgae-herbivore interactions have a main role in the regulation of marine community structure (top-down control). Gradients of warming prompt complex non-linear effects on organism metabolism, cascading into altered trophic interactions and community dynamics. However, not much is known on how will acidification and grazer assemblage composition shape these effects. Within this context, we aimed to assess the combined effects of warming gradients and acidification on macroalgae-herbivore interactions, using three cosmopolitan species, abundant in the Iberian Peninsula and closely associated in nature: the amphipod Melita palmata, the gastropod Gibbula umbilicalis, and the green macroalga Ulva rigida. Under two CO2 treatments (triangle CO2 similar or equal to 450 mu atm) across a temperature gradient (13.5, 16.6, 19.9 and 22.1 degrees C), two mesocosm experiments were performed to assess grazer consumption rates and macroalgae-herbivore interaction, respectively. Warming (Experiment I and II) and acidification (Experiment II) prompted negative effects in grazer's survival and species-specific differences in consumption rates. M. palmata was shown to be the stronger grazer per biomass (but not per capita), and also the most affected by climate stressors. Macroalgae-herbivore interaction strength was markedly shaped by the temperature gradient, while simultaneous acidification lowered thermal optimal threshold. In the near future, warming and acidification are likely to strengthen top-down control, but further increases in disturbances may lead to bottom-up regulated communities. Finally, our results suggest that grazer assemblage composition may modulate future macroalgae-herbivore interactions. (C) 2017 Elsevier Ltd. All rights reserved.Peer reviewe

    Uso de diseños jerárquicos en la detección de escalas de heterogeneidad en la especie invasora Sargassum muticum

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    Invasion of alien species poses serious threats to many ecosystems. Despite the potential of Sargassum muticum to spread and invade new areas, no attention has been given to the study of variability of structural or morphological features across different spatial scales. We employed a hierarchical sampling design to examine patterns of spatial variability of fertility and morphological variables of S. muticum over different spatial scales (quadrats, sites, locations, rias) ranging from metres to tens of kilometres We repeated the sampling in March, April and July to test for the consistency of patterns through time. There was no variability between rias (tens of kilometres apart), but substantial differences occurred at the other scales examined. Fertility and percent cover varied between locations (1.5-3 km apart), whereas morphological variables varied between sites (tens of metres apart) and quadrats (metres apart). Furthermore, patterns of variation were not consistent over time. The study demonstrated the importance of a multi-scale sampling programme for monitoring seaweed invasion.Las especies invasoras representan una seria amenaza para muchos ecosistemas. A pesar del potencial de Sargassum muticum para extenderse e invadir nuevas áreas, no se ha dedicado ninguna atención al estudio de la variabilidad de las características estructurales o morfológicas a diferentes escalas espaciales. Hemos usado un diseño de muestreo jerárquico para examinar patrones de variabilidad espacial de las variables fenológicas y morfológicas de S. muticum a diferentes escalas espaciales (cuadrantes, sitios, localidades, rías) que van desde unos pocos metros a decenas de kilómetros. Repetimos el muestreo en marzo, abril y julio para comprobar la consistencia de los patrones a lo largo del tiempo. No hubo variabilidad entre rías (decenas de kilómetros de separación), pero se encontraron diferencias sustanciales a otras escalas. La fertilidad y el porcentaje de cobertura variaron entre localidades (1.5-3 km) y tiempo, mientras que las variables morfológicas variaron entre sitios (decenas de metros) y cuadrantes (metros). Asimismo, los patrones de variabilidad no fueron consistentes en el tiempo. El estudio demostró la importancia de los programas de muestreo utilizando múltiples escalas espaciales para el seguimiento de algas invasoras

    Towards a sampling design for characterizing habitat-specific benthic biodiversity related to oxygen flux dynamics using Aquatic Eddy Covariance

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    The Aquatic Eddy Covariance (AEC) technique has emerged as an important method to quantify in situ seafloor metabolism over large areas of heterogeneous benthic communities, enabling cross-habitat comparisons of seafloor productivity. However, the lack of a corresponding sampling protocol to perform biodiversity comparisons across habitats is impeding a full assessment of marine ecosystem metabolism. Here, we study a range of coastal benthic habitats, from rocky-bed communities defined by either perennial macroalgae or blue mussel beds to soft-sediment communities comprised of either seagrass, patches of different macrophyte species or bare sand. We estimated that the maximum contribution to the AEC metabolic flux can be found for a seafloor area of approximately 80 m(2) with a 5 meter upstream distance of the instrument across all the habitats. We conducted a sampling approach to characterize and quantify the dominant features of biodiversity (i.e., community biomass) within the main seafloor area of maximum metabolic contribution (i.e., gross primary production and community respiration) measured by the AEC. We documented a high biomass contribution of the macroalgal Fucus vesiculosus, the seagrass Zostera marina and the macroinvertebrate Mytilus edulis to the net ecosystem metabolism of the habitats. We also documented a significant role of the bare sediments for primary productivity compared to vegetated canopies of the soft sediments. The AEC also provided insight into dynamic short-term drivers of productivity such as PAR availability and water flow velocity for the productivity estimate. We regard this study as an important step forward, setting a framework for upcoming research focusing on linking biodiversity metrics and AEC flux measurements across habitats.Peer reviewe

    Seasonal metabolism and carbon export potential of a key coastal habitat : The perennial canopy-forming macroalga Fucus vesiculosus

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    The important role of macroalgal canopies in the oceanic carbon (C) cycle is increasingly being recognized, but direct assessments of community productivity remain scarce. We conducted a seasonal study on a sublittoral Baltic Sea canopy of the brown alga Fucus vesiculosus, a prominent species in temperate and Arctic waters. We investigated community production on hourly, daily, and seasonal timescales. Aquatic eddy covariance (AEC) oxygen flux measurements integrated ~ 40 m2 of the seabed surface area and documented considerable oxygen production by the canopy year‐round. High net oxygen production rates of up to 35 ± 9 mmol m−2 h−1 were measured under peak irradiance of ~ 1200 μmol photosynthetically active radiation (PAR) m−2 s−1 in summer. However, high rates > 15 mmol m−2 h−1 were also measured in late winter (March) under low light intensities < 250 μmol PAR m−2 s−1 and water temperatures of ~ 1°C. In some cases, hourly AEC fluxes documented an apparent release of oxygen by the canopy under dark conditions, which may be due to gas storage dynamics within internal air spaces of F. vesiculosus. Daily net ecosystem metabolism (NEM) was positive (net autotrophic) in all but one of the five measurement campaigns (December). A simple regression model predicted a net autotrophic canopy for two‐thirds of the year, and annual canopy NEM amounted to 25 mol O2 m−2 yr−1, approximately six‐fold higher than net phytoplankton production. Canopy C export was ~ 0.3 kg C m−2 yr−1, comparable to canopy standing biomass in summer. Macroalgal canopies thus represent regions of intensified C assimilation and export in coastal waters.Peer reviewe

    Sandy beaches as biogeochemical hotspots : the metabolic role of macroalgal wrack on low-productive shores

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    Sandy beaches, which represent the most common type of land-sea interface, harbor distinctive biotic communities and regulate the flow of energy between marine and terrestrial ecosystems. Accumulations of sea wrack on sandy beaches are of crucial importance for recycling beach nutrients and for regulating trophic connectivity and coastal functioning. We investigated the role of beaches as biogeochemical hotspots by examining the metabolic activity in accumulations of different species of wrack on two exposed beaches affected by different levels of human pressure. Experimental wrack patches provided large amounts of different sedimentary nutrients over time due to remineralization of the algae. Unsurprisingly, the variation in the nutrients present in the beach sediments was related to the species of wrack considered. Macroalgal wrack was metabolically very active and supported high respiration rates represented by intense CO2 fluxes. Importantly, we demonstrated that the wrack metabolic rate differed significantly depending on the algal species considered. Different macrofauna and bacterial assemblages were identified in the different wrack patches and on the different beaches. We suggest that human activities such as beach grooming can modify the wrack-associated communities, thus contributing to the variability in the biogeochemical processes and metabolic rates. Significant changes in the type and amount of wrack deposited on beaches can change fundamental processes related to the marine-terrestrial transfer of nutrients and energy and to the marine-atmospheric transfer of CO2 emissions, with ecological consequences for nearshore environments.Peer reviewe

    Movimiento Popular de Resistencia Doce de Octubre en El Salvador contra las políticas neoliberales y propuestas de lucha hacia la transformación, (2003-2007)

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    En El Salvador, se han dado diferentes acontecimientos dejando huella y haciendo historia; pero en nuestra investigación se ha considerado hacer énfasis en las décadas más recientes, es decir de los años 70’s hasta el momento. Un periodo marcado por la represión, fraudes en las elecciones, el militarismo en toda su expresión; la violación continua de los Derechos Humanos, principalmente de las personas más pobres y vulnerables. En este contexto surgen las organizaciones Populares de Masas, integradas por sectores, entre estos los estudiantes, tanto universitarios como de secundaria, los campesinos, obreros, el sector sindical; todos estos integraron la Coordinadora Revolucionaria de Masas, una agrupación unitaria salvadoreña fundada el 11 de enero de 1980 para coordinar los esfuerzos de las organizaciones de masas, sus integrantes fueron el Frente de Acción Popular Unificada(FAPU, 1974), el Bloque Popular Revolucionario(BPR, 1975) y las Ligas Populares "28 de Febrero"(LP-28, 1977), a las que se sumó el frente abierto del Partido Comunista Salvadoreño, la Unión Democrática Nacionalista, hasta entonces un partido electoral que, con los socialdemócratas del Movimiento Nacional Revolucionario y el Partido Demócrata Cristiano (El Salvador), formaba la Unión Nacional Opositora. Posteriormente se sumaría a la CRM el Movimiento de Liberación Popular. Durante la década de los 80’s se desarrolló la guerra civil, una guerra entre la guerrilla y el ejército salvadoreño; dejando cantidad de asesinatos, capturas, torturas, desaparecidos y destrucción en casi todo el territorio, afectando principalmente a las personas de menos recursos y de las zonas rurales, teniendo estas que buscar refugio fuera del país. En este mismo periodo de los años 80.s se inicia la implementación del modelo neoliberal con una serie de medidas que solo han beneficiado a los empresarios y grupos empresarios; aumentado la pobreza y la exclusión social. Este fenómeno también generó el aumento de personas emigrantes principalmente hacia Estados Unidos. En 1992, se firman los Acuerdos de Paz, y se pone fin al conflicto armado, no así al conflicto existente: la desigualdad y la mala distribución de la riqueza del país. En este mismo periodo se van configurando una serie de ONG’s, que buscan a través de esta continuar la lucha, pero desde una nueva visión; inician un trabajo de asistencia a la población menos favorecida. Ya en el año 2000, comienzan a configurarse movimientos sociales de Resistencia, con un objetivo de lucha contra las políticas neoliberales y la puesta en marcha de tratados de libre comercio, que en ningún sentido han beneficiado a la población salvadoreña; entre estos el Movimiento Popular de Resistencia doce de octubre(MPR-12),objeto de estudio en esta investigación, conformado por una serie de sectores y ONG’s.Es a ese movimiento al cual hemos tomado como objeto de estudio, conocer su surgimiento, organización y la lucha que desarrollan contra las políticas del modelo neoliberal. Cumpliendo con las Etapas del Proceso de Graduación y en base al “Reglamento de Procesos de Graduación de la Universidad de El Salvador”, se presenta en este documento como anexo la etapa de: planificación de la investigación y comprende el plan de investigación social sobre las Fuerzas Sociales en El Salvador 1992-2007, que ha servido para definir tiempo y objetivos de todo el proceso de la investigación diagnóstico del presente sobre Las fuerzas sociales en El Salvador 1992 –2007, que permite un análisis previo de la problemática de la sociedad civil y política para hacer la identificación de las incompatibilidades entre ambas y dar lugar al surgimiento de los movimientos sociales, proyecto de investigación sobre Movimiento popular de resistencia doce de octubre en El Salvador contra las políticas neoliberales y propuestas de lucha hacia la transformación, 1992-2007, que permite conocer y analizar las motivaciones que han permitido el surgimiento en El Salvador del Movimiento Popular de Resistencia orientar el análisis de la realidad además permite orientar el proceso de construcción del objeto de estudio; en le proceso de investigación se realizó una aprehensión sobre los momentos históricos sobre la política neoliberal y la lucha de los Movimientos sociales ante estas; también problematizar sobre los momentos en que se ha desarrollado el MPR-12, y la presentación de una propuesta al movimiento para su fortalecimiento. Estos son algunos elementos que se toman en cuenta en parte 2 que es el informe final de la investigación que da a conocer el producto obtenido, de todo el proceso de investigación y análisis, un proceso presentado en tres capítulos y que tienen una relación con los objetivos planteados en el proyecto de Investigación Social

    Technological solutions for older people with Alzheimer’s disease : Review

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    Funding Information: The authors would like to acknowledge networking support from COST Action CA16226: Indoor living space improvement: Smart Habitat for the Elderly. COST (European Cooperation in Science and Technol-ogy) is a funding agency for research and innovation networks. Our Actions help connect research initiatives across Europe and enable scientists to grow their ideas by sharing them with their peers. This boosts their research, career and innovation. www.cost.eu. Furthermore, authors acknowledge the internal research project Excellence 2018, Faculty of Informatics and Management, University of Hradec Kralove, Czech Republic. Authors acknowledge the funding provided by FCT through the scholarship SFRH/BPD/115112/2016 (Joana Madureira) as well as to Solange Costa and João Paulo Teixeira, both from EPIUnit – Instituto de Saúde Pública da Universidade do Porto and National Institute of Heath, Environmental Health Department. Authors also acknowledge the funding from the University of Sts. Cyril and Methodius in Skopje, Faculty of Computer Science and Engineering. Publisher Copyright: © 2018 Bentham Science Publishers.In the nineties, numerous studies began to highlight the problem of the increasing number of people with Alzheimer’s disease in developed countries, especially in the context of demographic progress. At the same time, the 21st century is typical of the development of advanced technologies that penetrate all areas of human life. Digital devices, sensors, and intelligent applications are tools that can help seniors and allow better communication and control of their caregivers. The aim of the paper is to provide an up-to-date summary of the use of technological solutions for improving health and safety for people with Alzheimer’s disease. Firstly, the problems and needs of senior citizens with Alzheimer’s disease (AD) and their caregivers are specified. Secondly, a scoping review is performed regarding the technological solutions suggested to assist this specific group of patients. Works obtained from the following libraries are used in this scoping review: Web of Science, PubMed, Springer, ACM and IEEE Xplore. Four independent reviewers screened the identified records and selected relevant articles which were published in the period from 2007 to 2018. A total of 6,705 publications were selected. In all, 128 full papers were screened. Results obtained from the relevant studies were furthermore divided into the following categories according to the type and use of technologies: devices, processing, and activity recognition. The leading technological solution in the category of devices are wearables and ambient non-invasive sensors. The introduction and utilization of these technologies, however, bring about challenges in acceptability, durability, ease of use, communication, and power requirements. Furthermore, it needs to be pointed out that these technological solutions should be based on open standards.publishersversionPeer reviewe
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