A guide to avoid method bias of chromium(III, VI) chemiluminescence determination by luminol-hydrogen peroxide reaction. Application to unknown water samples

This is an Author's Accepted Manuscript of an article published in International Journal of Environmental & Analytical Chemistry, 83, 5, 405-416. DOI: 10.1080/0306731031000101383 © Taylor & Francis, available online at: http://doi.org/10.1080/0306731031000101383[EN] Cr(III) and/or Cr(VI) determinations based on light emission produced by luminol oxidation by hydrogen peroxide in basic aqueous solution catalyzed by Cr(III) were studied in order to diagnose and/or avoid method bias. The calibration step was optimized, and the usefulness of the method for speciating chromium was tested. The use of the standard addition method in the linear interval concentration range made it possible to diagnose the accuracy of the method for real samples. Good results were obtained for several real water samples containing chromium at different concentrations. The proposed protocol made the method traceable with an appropriate certified reference material and with the reference method.The authors are grateful to the DGICYT (Project n PB 97-1387) and to the Generalitat Valenciana (GR-0036) for financial support.Meseguer-Lloret, S.; Campins-Falcó, P.; Tortajada-Genaro, LA.; Blasco-Gómez, F. (2003). A guide to avoid method bias of chromium(III, VI) chemiluminescence determination by luminol-hydrogen peroxide reaction. Application to unknown water samples. International Journal of Environmental & Analytical Chemistry. 83(5):405-416. https://doi.org/10.1080/0306731031000101383S40541683

Moral Distress in Critical Care Nursing: The State of the Science

Background: Moral distress is a complex phenomenon frequently experienced by critical care nurses. Ethical conflicts in this practice area are related to technological advancement, high intensity work environments, and end-of-life decisions. Objectives: An exploration of contemporary moral distress literature was undertaken to determine measurement, contributing factors, impact, and interventions. Review Methods: This state of the science review focused on moral distress research in critical care nursing from 2009 to 2015, and included 12 qualitative, 24 quantitative, and 6 mixed methods studies. Results: Synthesis of the scientific literature revealed inconsistencies in measurement, conflicting findings of moral distress and nurse demographics, problems with the professional practice environment, difficulties with communication during end-of-life decisions, compromised nursing care as a consequence of moral distress, and few effective interventions. Conclusion: Providing compassionate care is a professional nursing value and an inability to meet this goal due to moral distress may have devastating effects on care quality. Further study of patient and family outcomes related to nurse moral distress is recommended

Multivariate calibration applied to simultaneous chemiluminiscence determination of Cobalt and Chromium

The final publication is available at http://doi.org/ 10.1007/s00216-002-1637-8[EN] The simultaneous determination of chromium and cobalt in water samples has been studied. Chemiluminescence registers based on the luminol-hydrogen peroxide reaction have obtained by a batch procedure. PLS algorithms have employed to model the time-response (formation and destruction of emitter). The influence of the presence of two metals and the non-linearity relationship between response and concentration have been evaluated in the signal. Different experimental designs and the selection of variables have been tested. The calibration set has been selected based on two criteria: unicomponent and/or bicomponent standard solutions and the slope calculated from linear univariate calibration. The response has been modelled providing high percentages of explained variance, robust models and low prediction errors. The proposed methodology has been validated using test standard solutions and a standard reference material of fresh water. Accurate results have proved the advantages of this method for the simultaneous determination of chromium and cobalt in water samples.The authors are grateful to the DGICYT (Project no PB 97–1387) for financial support. S.M.Ll. and L.A.T.G. express their gratitude to Ministerio de Educación y Cultura (Spain) for the predoctoral grant.Campins-Falcó, P.; Tortajada-Genaro, LA.; Meseguer-Lloret, S.; Bosch-Reig, F. (2002). Multivariate calibration applied to simultaneous chemiluminiscence determination of Cobalt and Chromium. Analytical and Bioanalytical Chemistry. 374(7-8):1223-1229. https://doi.org/10.1007/s00216-002-1637-8S122312293747-

Multi-Hop Synchronization at the Application Layer of Wireless and Satellite Networks

Time synchronization is a key issue in wireless and satellite networks; time-stamping collected data, tasks scheduling or efficient communications are just some applications. From all the existing techniques to achieve synchronization, those that work at the MAC layer and can precisely timestamp sync messages are the most accurate. However, working with standard protocols, usually prevents the user from accessing lower layers and consequently reduces accuracy. Receiver—receiver schema improves time-stamping performance because it eliminates the biggest non-deterministic error at the sender side; the medium access time. Nevertheless, utilization of these methods in multihop networks usually requires an extra amount of traffic. In this paper we present a method which allows accurate synchronization of large multi-hop networks such as satellite networks working at the application layer while keeping the message exchange to the minimum. Through an exhaustive experimentation, we show the protocol’s performance and analyze the factors that influence synchronization accuracy the most.Ministerio de Ciencia y Tecnología TIN2006-15617-C03-0

Mytilus galloprovincialis Myticin C: A Chemotactic Molecule with Antiviral Activity and Immunoregulatory Properties

Previous research has shown that an antimicrobial peptide (AMP) of the myticin class C (Myt C) is the most abundantly expressed gene in cDNA and suppressive subtractive hybridization (SSH) libraries after immune stimulation of mussel Mytilus galloprovincialis. However, to date, the expression pattern, the antimicrobial activities and the immunomodulatory properties of the Myt C peptide have not been determined. In contrast, it is known that Myt C mRNA presents an unusual and high level of polymorphism of unidentified biological significance. Therefore, to provide a better understanding of the features of this interesting molecule, we have investigated its function using four different cloned and expressed variants of Myt C cDNA and polyclonal anti-Myt C sera. The in vivo results suggest that this AMP, mainly present in hemocytes, could be acting as an immune system modulator molecule because its overexpression was able to alter the expression of mussel immune-related genes (as the antimicrobial peptides Myticin B and Mytilin B, the C1q domain-containing protein MgC1q, and lysozyme). Moreover, the in vitro results indicate that Myt C peptides have antimicrobial and chemotactic properties. Their recombinant expression in a fish cell line conferred protection against two different fish viruses (enveloped and non-enveloped). Cell extracts from Myt C expressing fish cells were also able to attract hemocytes. All together, these results suggest that Myt C should be considered not only as an AMP but also as the first chemokine/cytokine-like molecule identified in bivalves and one of the few examples in all of the invertebrates

Tensor completion in hierarchical tensor representations

Compressed sensing extends from the recovery of sparse vectors from undersampled measurements via efficient algorithms to the recovery of matrices of low rank from incomplete information. Here we consider a further extension to the reconstruction of tensors of low multi-linear rank in recently introduced hierarchical tensor formats from a small number of measurements. Hierarchical tensors are a flexible generalization of the well-known Tucker representation, which have the advantage that the number of degrees of freedom of a low rank tensor does not scale exponentially with the order of the tensor. While corresponding tensor decompositions can be computed efficiently via successive applications of (matrix) singular value decompositions, some important properties of the singular value decomposition do not extend from the matrix to the tensor case. This results in major computational and theoretical difficulties in designing and analyzing algorithms for low rank tensor recovery. For instance, a canonical analogue of the tensor nuclear norm is NP-hard to compute in general, which is in stark contrast to the matrix case. In this book chapter we consider versions of iterative hard thresholding schemes adapted to hierarchical tensor formats. A variant builds on methods from Riemannian optimization and uses a retraction mapping from the tangent space of the manifold of low rank tensors back to this manifold. We provide first partial convergence results based on a tensor version of the restricted isometry property (TRIP) of the measurement map. Moreover, an estimate of the number of measurements is provided that ensures the TRIP of a given tensor rank with high probability for Gaussian measurement maps.Comment: revised version, to be published in Compressed Sensing and Its Applications (edited by H. Boche, R. Calderbank, G. Kutyniok, J. Vybiral

Medición de parámetros fisicos, biológicos y químicos en el tramo estuarino del río Ebro

En este artículo se describen las campañas de campo CYTMAR I y II realizadas en la primavera y el verano de 1997, con el fin de estudiar los procesos y los flujos físicos, biológicos y químicos en la zona del Delta del Ebro, tanto en el tramo estuarino del río como en la pluma de agua dulce que se forma en las cercanías de la desembocadura. Aquí el estudio se ha centrado en la zona estuarina, presentando algunos resultados preliminares y analizando las diferencias estacionales observadas

On the compact operators case of the Bishop-Phelps-Bollobás property for numerical radius

The authors would like to thank Bill Johnson for kindly answering several inquiries.We study the Bishop–Phelps–Bollobás property for numerical radius restricted to the case of compact operators (BPBp-nu for compact operators in short). We show that C0(L) spaces have the BPBp-nu for compact operators for every Hausdorff topological locally compact space L. To this end, on the one hand, we provide some techniques allowing to pass the BPBp-nu for compact operators from subspaces to the whole space and, on the other hand, we prove some strong approximation property of C0(L) spaces and their duals. Besides, we also show that real Hilbert spaces and isometric preduals of ℓ1 have the BPBp-nu for compact operators

Baseline chronic comorbidity and mortality in laboratory-confirmed COVID-19 cases: Results from the PRECOVID study in Spain

We aimed to analyze baseline socio-demographic and clinical factors associated with an increased likelihood of mortality in men and women with coronavirus disease (COVID-19). We conducted a retrospective cohort study (PRECOVID Study) on all 4412 individuals with laboratory-confirmed COVID-19 in Aragon, Spain, and followed them for at least 30 days from cohort entry. We described the socio-demographic and clinical characteristics of all patients of the cohort. Age-adjusted logistic regressions models were performed to analyze the likelihood of mortality based on demographic and clinical variables. All analyses were stratified by sex. Old age, specific diseases such as diabetes, acute myocardial infarction, or congestive heart failure, and dispensation of drugs like vasodilators, antipsychotics, and potassium-sparing agents were associated with an increased likelihood of mortality. Our findings suggest that specific comorbidities, mainly of cardiovascular nature, and medications at the time of infection could explain around one quarter of the mortality in COVID-19 disease, and that women and men probably share similar but not identical risk factors. Nonetheless, the great part of mortality seems to be explained by other patient-and/or health-system-related factors. More research is needed in this field to provide the necessary evidence for the development of early identification strategies for patients at higher risk of adverse outcomes