Nurses' perceptions of aids and obstacles to the provision of optimal end of life care in ICU

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Acceleration of Quantitative Semisolid MT/CEST Imaging using a Generative Adversarial Network (GAN-CEST)

Quantitative metabolite concentration and pH biomarker maps, as provided by semisolid MT/CEST-MR-Fingerprinting (MRF), constitute a useful means for determining the molecular origin of pathology. However, the lengthy dictionary generation time and the prolonged 3D acquisition time may hinder clinical dissemination. Here, we developed a generative adversarial network (GAN), aimed to drastically shorten the 3D semisolid MT/CEST-MRF acquisition time and circumvent the need for dictionary generation. In-vitro and in-vivo experiments in 4 volunteers and a patient were conducted at 3 different sites using 3 different scanner models, showing substantial reduction in scan time, while retaining a good agreement with ground-truth referenc

The effects of marine protected areas on ecosystem recovery and fisheries using a comparative modelling approach

The overexploitation of many marine resources and ecosystems calls for the development and implementation of measures to support their recovery and conservation. The potential contributions to support fisheries and ecosystem recovery were assessed at the local level of the three multiple-use marine protected areas (MPAs) of Cerbère-Banyuls, Medes Islands, and Cap de Creus, located in the north-western Mediterranean Sea. For each MPA, a food-web model accounting for each protection level (PL) was developed: the fully protected area (FPA), the partially protected area (PPA) and the unprotected area (UPA) surrounding the MPA. Using the resulting nine food-web models, the ecosystem structure and functioning of each PL were compared and characterized, differences and similarities within and among the three MPAs were assessed, and ecosystem response to full protection was evaluated for the three MPAs. Differences in terms of ecosystem structure and functioning were found among PLs. Overall, FPAs presented the most positive effect of protection in terms of ecosystem structure and functioning, followed by PPAs. However, the effects of protection on neighbouring UPAs were hardly noticeable. Similarities between Cerbère-Banyuls and Medes Islands MPAs were observed, while Cap de Creus MPA showed the least benefits from protection overall. These results are likely to be due to similarities in the configuration of the protected areas, the levels of enforcement and compliance, and the impact of recreational and small-scale fisheries allowed in the PPAs and UPAs. This study illustrates that well-enforced Mediterranean MPAs, even when small, can yield local positive impacts on the structure and functioning of marine ecosystems that can contribute to support local fisheries

Reduction of Effects of Noise on the Inverse Problem of Electrocardiography with Bayesian Estimation

To overcome the ill-posed nature of the inverse problem of electrocardiography (ECG) and stabilize the solutions, regularization is used. Despite several studies on noise, effect of prefiltering of ECG signals on the regularized inverse solutions has not been explored. We used Bayesian estimation for solving the inverse ECG problem with and without applying various prefiltering methods, and evaluated our results using experimental data that came from a Langendorff-perfused pig heart suspended in a human-shaped torso-tank. Epicardial electrograms were recorded during RV pacing using a 108-electrode array, simultaneously with ECGs from 128 electrodes embedded in the tank surface. Leave-one-beat-out protocol was used to obtain the prior probability density function (pdf) of electrograms and noise statistics. Noise pdf was assumed to be zero mean-Gaussian, with covariance assumptions: a) independent and identically distributed (noi-iid), b) correlated (noi-corr). Reconstructed electrograms and activation times were compared to those directly recorded by the sock for 3 beats selected from the recording. Noi-corr is superior to noi-iid when the training set is a good match to data, but for applications requiring activation time derivation, careful selection of preprocessing methods, in particular to adequately remove high frequency noise, and an appropriate noise model is needed

Accelerated and quantitative three-dimensional molecular MRI using a generative adversarial network

Purpose: To substantially shorten the acquisition time required for quantitative three-dimensional (3D) chemical exchange saturation transfer (CEST) and semisolid magnetization transfer (MT) imaging and allow for rapid chemical exchange parameter map reconstruction.Methods: Three-dimensional CEST and MT magnetic resonance fingerprinting (MRF) datasets of L-arginine phantoms, whole-brains, and calf muscles from healthy volunteers, cancer patients, and cardiac patients were acquired using 3T clinical scanners at three different sites, using three different scanner models and coils. A saturation transfer-oriented generative adversarial network (GAN-ST) supervised framework was then designed and trained to learn the mapping from a reduced input data space to the quantitative exchange parameter space, while preserving perceptual and quantitative content.Results: The GAN-ST 3D acquisition time was 42-52 s, 70% shorter than CEST-MRF. The quantitative reconstruction of the entire brain took 0.8 s. An excellent agreement was observed between the ground truth and GAN-based L-arginine concentration and pH values (Pearson's r > 0.95, ICC > 0.88, NRMSE and 4.6±1.3% , respectively, and SSIM of 96.3±1.6% and 95.0±2.4%, respectively. The mapping of the calf-muscle exchange parameters in a cardiac patient, yielded NRMSE 94% for the semi-solid exchange parameters. In regions with large susceptibility artifacts, GAN-ST has demonstrated improved performance and reduced noise compared to MRF.Conclusion: GAN-ST can substantially reduce the acquisition time for quantitative semi-solid MT/CEST mapping, while retaining performance even when facing pathologies and scanner models that were not available during training

The educational landscape of the digital age: Communication practices pushing (us) forward

En aquest article, s’identificaran alguns models i tendències emergents en la producció de coneixement. Es farà èmfasi especialment en com els individus implicats en els processos de consum i de distribució de la informació expressen diferents nivells de solidaritat i de compromís, i se suggerirà que és crucial que les persones no només coneguin aquests processos, sinó que també estiguin obertes a altres models, oportunitats i possibilitats que, donades les condicions sociotecnològiques i comunicatives actuals, encara s’han de desenvolupar. S’abordarà amb especial interès l’àmbit de l’educació, ja que s’entén que els educadors estan participant de forma compromesa en una profunda renovació pedagògica a través de projectes compartits cimentats en interaccions professionals i personals facilitades per les xarxes. Aquestes interaccions afavoreixen l’emergència de models pedagògics que permeten a professors i a alumnes convertir-se en experts al mateix temps que trenquen amb moltes convencions epistemològiques clàssiques. Aquestes pedagogies generades d’avall cap amunt no només fomenten la creativitat i la col·laboració i se sustenten en l’ús de noves eines digitals, sinó que les promouen i impulsen els interessos de l’alumnat, i per això, tenen el potencial suficient per tornar l’alegria al procés d’aprenentatge. Per acabar, s’argumentarà que els models emergents en la construcció del coneixement a través de les TIC ofereixen nous paisatges culturals i ecologies d’aprenentatge que trastoquen les inscripcions tradicionals de les identitats individuals i les afinitats racials i culturals.This paper identifies trends in the emerging models of knowledge production available in our society. We suggest it is crucial not only to be aware of these emerging models but also to be open to opportunities and possibilities that may still develop. We consider how people may express different levels of solidarity and commitment to these trends and models in their information consumption and distribution processes. We discuss how educators are now engaging in profound pedagogical renewal by expressing deeper levels of solidarity and commitment to knowledge production and educational projects through professional and personal interactions. These interactions are producing pedagogical models that allow both teachers and learners to become knowledgeable while simultaneously breaking away from domain conventions. These bottom-up pedagogies foster creativity, collaboration and the use of new digital tools. They are driven by learner interests and, as such, have the potential to bring the joy back into the learning process. Finally, we argue that emerging models of knowledge construction mediated by ICT provide new cultural landscapes and ecologies of learning that disrupt traditional inscriptions of individual identities and racial-cultural affinities.En este artículo, se identificarán algunos modelos y tendencias emergentes en la producción de conocimiento. Se hará hincapié especialmente en cómo los individuos implicados en los procesos de consumo y de distribución de la información expresan diferentes niveles de solidaridad y de compromiso, y se sugerirá que es crucial que las personas no solo conozcan estos procesos, sino que también estén abiertas a otros modelos, oportunidades y posibilidades que, dadas las condiciones sociotecnológicas y comunicativas actuales, aún deben desarrollarse. Se abordará con especial interés el ámbito de la educación, puesto que se entiende que los educadores están participando de forma comprometida en una profunda renovación pedagógica a través de proyectos compartidos cimentados en interacciones profesionales y personales facilitadas por las redes. Estas interacciones favorecen la emergencia de modelos pedagógicos que permiten a profesores y a alumnos convertirse en expertos al mismo tiempo que rompen con muchas convenciones epistemológicas clásicas. Estas pedagogías generadas de abajo arriba no solo fomentan la creatividad y la colaboración, y se sustentan en el uso de nuevas herramientas digitales, sino que las promueven e impulsan los intereses del alumnado, y por ello, tienen el potencial suficiente para devolverle la alegría al proceso de aprendizaje. Por último, se argumentará que los modelos emergentes en la construcción del conocimiento a través de las TIC ofrecen nuevos paisajes culturales y ecologías de aprendizaje que trastocan las inscripciones tradicionales de las identidades individuales y las afinidades raciales y culturales