968 research outputs found

    Gene expression of endangered coral (Orbicella spp.) in flower garden banks National Marine Sanctuary after Hurricane Harvey

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    About 190 km south of the Texas–Louisiana border, the East and West Flower Garden Banks (FGB) have maintained > 50% coral cover with infrequent and minor incidents of disease or bleaching since monitoring began in the 1970s. However, a mortality event, affecting 5.6 ha (2.6% of the area) of the East FGB, occurred in late July 2016 and coincided with storm-generated freshwater runoff extending offshore and over the reef system. To capture the immediate effects of storm-driven freshwater runoff on coral and symbiont physiology, we leveraged the heavy rainfall associated with Hurricane Harvey in late August 2017 by sampling FGB corals at two time points: September 2017, when surface water salinity was reduced (∼34 ppt); and 1 month later when salinity had returned to typical levels (∼36 ppt in October 2017). Tissue samples (N = 47) collected midday were immediately preserved for gene expression profiling from two congeneric coral species (Orbicella faveolata and Orbicella franksi) from the East and West FGB to determine the physiological consequences of storm-derived runoff. In the coral, differences between host species and sampling time points accounted for the majority of differentially expressed genes. Gene ontology enrichment for genes differentially expressed immediately after Hurricane Harvey indicated increases in cellular oxidative stress responses. Although tissue loss was not observed on FGB reefs following Hurricane Harvey, our results suggest that poor water quality following this storm caused FGB corals to experience sub-lethal stress. We also found dramatic expression differences across sampling time points in the coral’s algal symbiont, Breviolum minutum. Some of these differentially expressed genes may be involved in the symbionts’ response to changing environments, including a group of differentially expressed post-transcriptional RNA modification genes. In this study, we cannot disentangle the effects of reduced salinity from the collection time point, so these expression patterns could also be related to seasonality. These findings highlight the urgent need for continued monitoring of these reef systems to establish a baseline for gene expression of healthy corals in the FGB system across seasons, as well as the need for integrated solutions to manage stormwater runoff in the Gulf of Mexico.https://www.frontiersin.org/articles/10.3389/fmars.2019.00672/fullPublished versionPublished versio

    Integration of genetic data on fisheries management models. The European hake case.

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    The European hake is one of the major commercially important species in Western Europe fisheries. Currently its management is divided into different functional units in the Mediterranean (GFCM, General Fisheries Commission for the Mediterranean) and two stocks in the Atlantic: the Southern and the Northern Stock. The basis for the definition of this management stock structure is under permanent discussion and in the latest years there were an increased amount of genetic studies addressing this topic. Integrated ecosystem assessment requires an improved understanding of the marine ecosystem to provide an effective advice. To this end we have gathered hake genetic information from different studies with the aim of developing a spatial assessment model that links the current stocks. These studies show a restricted gene flow between Southern hake and Mediterranean hake, although a smaller genetic distance between Southern and Northern stocks than one expected from two independent populations, suggesting the presence of a major gene flow from northern grounds core stock (Porcupine and Great Sole Banks) towards the Bay of Biscay and the northwest coast of the Iberian Peninsula. However the quantitative implementation of genetic metrics (such as Fst, migration rates, etc) into population dynamic models is not straightforward given the different nature and assumptions behind these different approaches. In this work we discuss the problems to link these different disciplines suggesting ways to overcome them. These include ways to improve future genetic sampling and developing plausible scenarios for genetic connectivity in population dynamic models

    From imaging to simulation: a framework applied to simulate the blood flow in the carotids

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    In this work we present a methodology to extract information from medical imaging and use it for hemodynamical simulation in arteries. Based on in-vivo magnetic resonance images (MRI), the velocity of the blood flow has been measured at different positions and times. Also, the anatomy of the vessel has been converted into a volume mesh suitable for numerical modeling. This data has been used to solve computationally the dynamics of the fluid inside the artery in healthy and pathologic cases. As an application, we have developed a computational model within the carotids. The next step in the pipeline will be to extend the simulation to fluidstructure interaction (FSI) to find the parameters in an atherosclerotic plaque that could lead to rupture.Peer Reviewe

    From imaging to simulation: a framework applied to simulate the blood flow in the carotids

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    In this work we present a methodology to extract information from medical imaging and use it for hemodynamical simulation in arteries. Based on in-vivo magnetic resonance images (MRI), the velocity of the blood flow has been measured at different positions and times. Also, the anatomy of the vessel has been converted into a volume mesh suitable for numerical modeling. This data has been used to solve computationally the dynamics of the fluid inside the artery in healthy and pathologic cases. As an application, we have developed a computational model within the carotids. The next step in the pipeline will be to extend the simulation to fluidstructure interaction (FSI) to find the parameters in an atherosclerotic plaque that could lead to rupture.Peer Reviewe

    The effects of cocaine self-administration on dendritic spine density in the rat hippocampus are dependent on genetic background

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    Chronic exposure to cocaine induces modifications to neurons in the brain regions involved in addiction. Hence, we evaluated cocaine-induced changes in the hippocampal CA1 field in Fischer 344 (F344) and Lewis (LEW) rats, 2 strains that have been widely used to study genetic predisposition to drug addiction, by combining intracellular Lucifer yellow injection with confocal microscopy reconstruction of labeled neurons. Specifically, we examined the effects of cocaine self-administration on the structure, size, and branching complexity of the apical dendrites of CA1 pyramidal neurons. In addition, we quantified spine density in the collaterals of the apical dendritic arbors of these neurons. We found differences between these strains in several morphological parameters. For example, CA1 apical dendrites were more branched and complex in LEW than in F344 rats, while the spine density in the collateral dendrites of the apical dendritic arbors was greater in F344 rats. Interestingly, cocaine self-administration in LEW rats augmented the spine density, an effect that was not observed in the F344 strain. These results reveal significant structural differences in CA1 pyramidal cells between these strains and indicate that cocaine self-administration has a distinct effect on neuron morphology in the hippocampus of rats with different genetic backgrounds

    Experimental data on SOA formation from mixtures of anthropogenic and biogenic organic compounds

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    AbstractSecondary organic aerosols (SOA) constitute a significant fraction of the atmospheric particulate matter. Theses particles are formed as a consequence of the oxidation reaction of certain organic gases that leads to the formation of low-volatility compounds. As for other pollutants, air quality models allow the simulation of particle levels and thus models constitute a powerful tool in air quality management. Nevertheless, the accepted use of models must be based on the validation of its capacity to reproduce observed concentrations. Air monitoring sites provide measured information of a large variety of ambient pollutants. Unfortunately, measurements on SOA are not normally available, as current monitoring networks do not include instrumentation to distinguish primary from secondary sources of organic carbonaceous aerosol. This paper presents a set of photooxidation experiments performed in the European Photorreactor (EUPHORE) smog chamber (CEAM, Spain) under different experimental conditions to investigate SOA formation. The use of chambers allows the isolation of atmospheric chemistry and aerosol formation processes. Thus, although these measurements were obtained at initial precursor concentrations higher than those in atmospheric conditions, they constitute a valuable set of information for SOA model evaluation purposes

    On-Chip Solar Energy Harvester and PMU With Cold Start-Up and Regulated Output Voltage for Biomedical Applications

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    This paper presents experimental results from a system that comprises a fully autonomous energy harvester with a solar cell of 1 mm 2 as energy transducer and a Power Management Unit (PMU) on the same silicon substrate, and an output voltage regulator. Both chips are implemented in standard 0.18 μm CMOS technology with total layout areas of 1.575 mm 2 and 0.0126 mm 2 , respectively. The system also contains an off-the-shelf 3.2 mm × 2.5 mm × 0.9 mm supercapacitor working as an off-chip battery or energy reservoir between the PMU and the voltage regulator. Experimental results show that the fast energy recovery of the on-chip solar cell and PMU permits the system to replenish the supercapacitor with enough charge as to sustain Bluetooth Low Energy (BLE) communications even with input light powers of 510 nW. The whole system is able to self-start-up without external mechanisms at 340 nW. This work is the first step towards a self-supplied sensor node with processing and communication capabilities. The small form factor and ultra-low power consumption of the system components is in compliance with biomedical applications requirementsThis work was supported in part by the Spanish Government (Ministerio de Ciencia, Innovación y Universidades) under Project RTI2018-097088-B-C32 and Project RTI2018-095994-B-I00 (MICINN/FEDER), in part by the Xunta de Galicia, in part by the Consellería de Cultura, Educación e Ordenación Universitaria (accreditation 2016-2019, ED431G/08 and reference competitive group 2017-2020, ED431C 2017/69) and European Regional Development Fund (ERDF), and in part by the Junta de Extremadura and the ERDF, under Grant IB 18079S

    Comparison of chemical compounds associated with sclerites from healthy and diseased sea fan corals (Gorgonia ventalina)

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    © The Author(s), 2017. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in PeerJ 5 (2017): e3677, doi:10.7717/peerj.3677.The roles of gorgonian sclerites as structural components and predator deterrents have been widely studied. Yet their role as barriers against microbes has only recently been investigated, and even less is known about the diversity and roles of the chemical compounds associated with sclerites. Here, we examine the semi-volatile organic compound fraction (SVOCs) associated with sclerites from healthy and diseased Gorgonia ventalina sea fan corals to understand their possible role as a stress response or in defense of infection. We also measured the oxidative potential of compounds from diseased and healthy G. ventalina colonies. The results showed that sclerites harbor a great diversity of SVOCs. Overall, 70 compounds were identified, the majority of which are novel with unknown biological roles. The majority of SVOCs identified exhibit multiple immune-related roles including antimicrobial and radical scavenging functions. The free radical activity assays further confirmed the anti-oxidative potential of some these compounds. The anti-oxidative activity was, nonetheless, similar across sclerites regardless of the health condition of the colony, although sclerites from diseased sea fans display slightly higher anti-oxidative activity than the healthy ones. Sclerites harbor great SVOCs diversity, the majority of which are novel to sea fans or any other corals. Yet the scientific literature consulted showed that the roles of compounds found in sclerites vary from antioxidant to antimicrobial compounds. However, this study fell short in determine the origin of the SVOCs identified, undermining our capacity to determine the biological roles of the SVOCs on sclerites and sea fans.This work was supported by the Puerto Rico Center for Environmental Neuroscience (PRCEN) through an NSF Centers of Research Excellent in Science and Technology (CREST) award, number HRD-1137725
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