200 research outputs found

    Identifying cold-water coral ecosystem by using benthic foraminiferal indicators: from active reefs to the geological record

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    Cold-water coral ecosystems dominated by the species Lophelia pertusa and Madrepora oculata, as well as cold-water coral carbonate mounds (fossils and/or active) occur worldwide and are especially developed along the European margin, from northern Norway to the Gulf of Cadiz and into the Alboran Sea. Their discovery is a major achievement of the last few decades and their widespread occurrence presents a challenge to understand their development, preservation and possible importance in the geologic record.On the Norwegian shelf active/living reefs are developed on elevated hard substrata. Along the Irish margin L. pertusa builds large fossil and/or active carbonate mounds. In the Gulf of Cadiz and in the Alboran Sea buried reefs and patch reefs are generally found in association with mud volcanoes.In modern oceans, they provide important ecological niches for the marine benthic fauna in the deep-sea. In comparison to the macrofauna the microfauna, particularly the foraminifera associated to these systems, are poorly known. We present here a detailed study based on quantitative analyses of benthic and planktonic foraminifera together with the statistical treatment of assemblage data collected along the Norwegian margin, in the Porcupine-Rockall region and in the Alboran Sea.The three regions were and/or are site of cold-water coral ecosystems settlements. Our study reveals that in the Porcupine/Rockall region benthic foraminiferal assemblages are strictly related to the distribution of facies. On the Norwegian margin, benthic foraminiferal habitats are weakly defined and grade one into the other preventing the sharp facies separation observed along the Irish margin (Margreth et al., 2009). In the Alboran Sea cold-water coral ecosystems and cold-water carbonate mounds are presently buried and corals are generally fragmented. However, benthic assemblages from coral-rich layers in the Alboran Sea and those from Porcupine/Rockall and Norway show remarkable similarities. In particular, epifaunal-attached species such as Discanomalina coronata, Cibicides refulgens, and Lobatula lobatula dominate the assemblages with D. coronata restricted to living cold-water coral reefs facies only and/or in co-occurrence with coral fragments. In conclusion, our data suggest that although cold-water coral ecosystems occur at different latitudes, the associated foraminiferal assemblages are consistent from Norway to the Western Mediterranean. Thus they can be used to identify these ecosystems even in the geologic record, when the corals are often strongly dissolved like in the Alboran Sea

    The R.V. Pelagia pre-drilling site survey at the Rockall and Porcupine cold water coral mounds provinces, European Atlantic margin. The CARBONATE project, ESF EuroMARC program

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    From 30 September to 22 October 2007 a cruise with the Royal NIOZ research vessel Pelagia was carried out within the framework of the ESF (EuroMARC) project CARBONATE. The goal of this cruise was to complete the existing data set of carbonate mounds present at the European Atlantic margin in order to be able to choose suitable coring sites to drill complete top to base sections through the carbonate mounds with the MeBo drilling device. This is a remotely operated drill that is placed at the sea floor and capable of drilling sediment cores with a maximum length of 85 metres. The drilling cruise, with the Irish research vessel Celtic Explorer, is planned to take place in the summer of 2008.During the Pelagia cruise 5 carbonate mound provinces were visited. The mounds were selected based on two main criteria:the mound provinces should represent different stages in mound developmentit must be possible to penetrate the mounds from top to base with the MeBo (expected maximum sequence thickness in the order of 75 m)The first area that was visited is located at the SE Rockall Bank margin. These mounds are characterised by abundant living cold water corals at their top. The second mound province that was visited is located at the SW Rockall Bank. Initially a large mound cluster known as Franken Mound was chosen for detailed studies. This mound, as well as smaller mounds in the vicinity, is dominated by dead corals and it is considered to be in what is often called the retirement stage. At theWand N margin of the Porcupine Bank two areas were visited. Most of the mounds occur as isolated structures. Only limited amounts of living cold water corals are present. The mounds in the last area that was visited are also referred to as the Magellan Mounds. This is a group of small (<100 m) mounds located in the Porcupine Seabight. These mounds are mostly fully buried and thus represent the final stage of mound development.At all sites a multibeam bathymetric survey was carried out. Subsequently a benthic lander was deployed which was equipped for a period of 2 to 4 days to measure near bed hydrography and sediment transport. This was followed by seismic and video surveys.The initial results of the cruise indicate that at all proposed drilling sites carbonate mounds with a total thickness that can be penetrated by the MeBo are present. The video observations did not reveal the presence of any rough terrain that may hamper the positioning of the MeBo at the seabed

    Calcium Homeostasis in Myogenic Differentiation Factor 1 (MyoD)-Transformed, Virally-Transduced, Skin-Derived Equine Myotubes

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    Dysfunctional skeletal muscle calcium homeostasis plays a central role in the pathophysiology of several human and animal skeletal muscle disorders, in particular, genetic disorders associated with ryanodine receptor 1 (RYR1) mutations, such as malignant hyperthermia, central core disease, multiminicore disease and certain centronuclear myopathies. In addition, aberrant skeletal muscle calcium handling is believed to play a pivotal role in the highly prevalent disorder of Thoroughbred racehorses, known as Recurrent Exertional Rhabdomyolysis. Traditionally, such defects were studied in human and equine subjects by examining the contractile responses of biopsied muscle strips exposed to caffeine, a potent RYR1 agonist. However, this test is not widely available and, due to its invasive nature, is potentially less suitable for valuable animals in training or in the human paediatric setting. Furthermore, increasingly, RYR1 gene polymorphisms (of unknown pathogenicity and significance) are being identified through next generation sequencing projects. Consequently, we have investigated a less invasive test that can be used to study calcium homeostasis in cultured, skin-derived fibroblasts that are converted to the muscle lineage by viral transduction with a MyoD (myogenic differentiation 1) transgene. Similar models have been utilised to examine calcium homeostasis in human patient cells, however, to date, there has been no detailed assessment of the cells’ calcium homeostasis, and in particular, the responses to agonists and antagonists of RYR1. Here we describe experiments conducted to assess calcium handling of the cells and examine responses to treatment with dantrolene, a drug commonly used for prophylaxis of recurrent exertional rhabdomyolysis in horses and malignant hyperthermia in humans

    External validation of a prediction model for disability and pain after lumbar disc herniation surgery:a prospective international registry-based cohort study

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    Background and purpose — We aimed to externally validate machine learning models developed in Norway by evaluating their predictive outcome of disability and pain 12 months after lumbar disc herniation surgery in a Swedish and Danish cohort. Methods — Data was extracted for patients undergoing microdiscectomy or open discectomy for lumbar disc herniation in the NORspine, SweSpine and DaneSpine national registries. Outcome of interest was changes in Oswestry disability index (ODI) (≥ 22 points), Numeric Rating Scale (NRS) for back pain (≥ 2 points), and NRS for leg pain (≥ 4 points). Model performance was evaluated by discrimination (C-statistic), calibration, overall fit, and net benefit. Results — For the ODI model, the NORspine cohort included 22,529 patients, the SweSpine cohort included 10,129 patients, and DaneSpine 5,670 patients. The ODI model’s C-statistic varied between 0.76 and 0.81 and calibration slope point estimates varied between 0.84 and 0.99. The C-statistic for NRS back pain varied between 0.70 and 0.76, and calibration slopes varied between 0.79 and 1.03. The C-statistic for NRS leg pain varied between 0.71 and 0.74, and calibration slopes varied between 0.90 and 1.02. There was acceptable overall fit and calibration metrics with minor–modest but explainable heterogeneity observed in the calibration plots. Decision curve analyses displayed clear potential net benefit in treatment in accordance with the prediction models compared with treating all patients or none. Conclusion — Predictive performance of machine learning models for treatment success/non-success in disability and pain at 12 months post-surgery for lumbar disc herniation showed acceptable discrimination ability, calibration, overall fit, and net benefit reproducible in similar international contexts. Future clinical impact studies are required.</p

    Framing vulnerability, risk and societal responses: the MOVE framework

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    The paper deals with the development of a general as well as integrative and holistic framework to systematize and assess vulnerability, risk and adaptation. The framework is a thinking tool meant as a heuristic that outlines key factors and different dimensions that need to be addressed when assessing vulnerability in the context of natural hazards and climate change. The approach underlines that the key factors of such a common framework are related to the exposure of a society or system to a hazard or stressor, the susceptibility of the system or community exposed, and its resilience and adaptive capacity. Additionally, it underlines the necessity to consider key factors and multiple thematic dimensions when assessing vulnerability in the context of natural and socio-natural hazards. In this regard, it shows key linkages between the different concepts used within the disaster risk management (DRM) and climate change adaptation (CCA) research. Further, it helps to illustrate the strong relationships between different concepts used in DRM and CCA. The framework is also a tool for communicating complexity and stresses the need for societal change in order to reduce risk and to promote adaptation. With regard to this, the policy relevance of the framework and first results of its application are outlined. Overall, the framework presented enhances the discussion on how to frame and link vulnerability, disaster risk, risk management and adaptation concepts

    Data splitting as a countermeasure against hypothesis fishing: with a case study of predictors for low back pain

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    There is growing concern in the scientific community that many published scientific findings may represent spurious patterns that are not reproducible in independent data sets. A reason for this is that significance levels or confidence intervals are often applied to secondary variables or sub-samples within the trial, in addition to the primary hypotheses (multiple hypotheses). This problem is likely to be extensive for population-based surveys, in which epidemiological hypotheses are derived after seeing the data set (hypothesis fishing). We recommend a data-splitting procedure to counteract this methodological problem, in which one part of the data set is used for identifying hypotheses, and the other is used for hypothesis testing. The procedure is similar to two-stage analysis of microarray data. We illustrate the process using a real data set related to predictors of low back pain at 14-year follow-up in a population initially free of low back pain. “Widespreadness” of pain (pain reported in several other places than the low back) was a statistically significant predictor, while smoking was not, despite its strong association with low back pain in the first half of the data set. We argue that the application of data splitting, in which an independent party handles the data set, will achieve for epidemiological surveys what pre-registration has done for clinical studies

    Prediction of hysteretic matric potential dynamics using artificial intelligence: application of autoencoder neural networks

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    Information on soil water potential is essential to assessing the soil moisture state, to prevent soil compaction in weak soils, and to optimize crop management. When there is a lack of direct measurements, the soil water potential values must be deduced from soil water content dynamics that can be monitored at the plot scale or obtained at a larger scale from remote sensing information. Because the relationship between water content and soil water potential in natural field soils is highly ambiguous, the prediction of soil water potential from water content data is a big challenge. The hysteretic relationship observed in nine soil profiles in the region of Solothurn (Switzerland) is not a simple function of texture or wetting–drainage cycles but depends on seasonal patterns that may be related to soil structural dynamics. Because the physical mechanisms governing seasonal hysteresis are unclear, we developed a deep neural network model that predicts water potential changes using rainfall, potential evapotranspiration, and water content time series as inputs. To adapt the model for multiple locations, we incorporated a deep autoencoder neural network as a classifier. The autoencoder compresses the water content time series into a site-specific feature that is highly representative of the underlying water content dynamics of each site and quantifies the similarity of dynamic patterns. By adding the autoencoder's output as an additional input and training the neural network model with three stations located in three major classes established by the autoencoder, we predict matric potential for other sites. This method has the potential to deduce the dynamics of matric potential from water content data (including satellite data) despite strong seasonal effects that cannot be captured by standard methods.</p
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