Uncertainty in Hyperspectral Remote Sensing: Analysis of the Potential and Limitation of Shallow Water Bathymetry and Benthic Classification

Propagating the inherent uncertainty in hyperspectral remote sensing is key in understanding the limitation and potential of derived bathymetry and benthic classification. Using an improved optimisation algorithm, the potential of detecting temporal bathymetric changes above uncertainty was quantified from a time series of hyperspectral imagery. A new processing approach was also developed that assessed the limitations and potential of benthic classification by analysing optical separability of substrates above total system uncertainty and attenuating water column

Caracterización y análisis de modelos de evaluación económica de proyectos de inversión bajo incertidumbre

Este articulo presenta los métodos  actualmente disponibles para la evaluación de proyectos, dejando de manifiesto las falencias de los métodos tradicionales como el Método de Flujos de Caja Descontados, cuando son usados para evaluar proyectos con alta incertidumbre, donde además los administrativos cuentan con la flexibilidad suficiente para cambiar su planificación y adaptarse a variaciones en las condiciones iniciales del mercado. Se caracterizan y comparan aquellos modelos que logran entregar una evaluación más realista de esta clase de proyectos, al considerar dentro de la misma la incertidumbre y la flexibilidad como factores determinantes en la toma de decisiones. Como solución se propone la utilización del análisis de opciones reales para evaluar los proyectos donde las herramientas tradicionales son insuficientes por sí solas. Esta teoría nace en la evaluación de opciones de activos financieros, y actualmente se está utilizando de forma similar en la evaluación de proyectos de inversión, haciendo un símil con los activos financieros. Para llegar a la selección del análisis de opciones reales como modelo a utilizar, se realizó una recopilación bibliográfica extensa de las publicaciones relacionadas con la teoría de opciones reales escritas por distintos investigadores a lo largo de los últimos años. La metodología de opciones reales se somete a un análisis comparativo frente a los modelos basados en los Flujos de Caja Descontados y el Análisis de Árboles de Decisión. Se presenta la evaluación de un proyecto utilizando tres métodos para evaluar el proyecto bajo el enfoque de opciones reales: la ecuación de Black-Scholes, Simulación Monte Carlo y los Árboles Binomiales, efectuando un análisis de los resultados de la evaluación del proyectos según los diferentes modelos empleados.This present paper introduces those methods that are currently available for project assessment. It emphasises the limitations of the traditional methods, such as the Discounted Cash Flow Method, when being used to evaluate highly uncertain projects, where decision makers have the flexibility enough to change the course of the project to meet those changes that had taken place at the market early stages. Those models that are able to provide a more level-headed assessment for this kind of project – where uncertainty and flexibility have become key factors in the decision making process – have been distinguished and compared. As a solution to this, the application of Real Option Analysis procedure has been suggested to valuate projects, since traditional tools are not enough by themselves. This theory arises from the evaluation of financial assets and is currently being used for the assessment of investment related projects, the same way as it can be used in the case of financial assets. Decision about using the real option analysis as the model to be applied was reached after carrying out an extensive bibliographical compilation regarding this real option analysis theory, in turn written by several researchers during the last few years. This methodology is subjected to comparative analysis with respect to those Discounted Cash Flow and Decision Tree Analysis based models. The evaluation of a given project – by applying the three project evaluation methods: Black-Scholes, Monte Carlo Simulation and Binomial Trees - is introduced. Finally, an analysis of the project evaluation outcomes under the different models being applied, is carried out

Computational Evolution Protocol for Peptide Design

Computational peptide design is useful for therapeutics, diagnostics, and vaccine development. To select the most promising peptide candidates, the key is describing accurately the peptide-target interactions at the molecular level. We here review a computational peptide design protocol whose key feature is the use of all-atom explicit solvent molecular dynamics for describing the different peptide-target complexes explored during the optimization. We describe the milestones behind the development of this protocol, which is now implemented in an open-source code called PARCE. We provide a basic tutorial to run the code for an antibody fragment design example. Finally, we describe three additional applications of the method to design peptides for different targets, illustrating the broad scope of the proposed approach

Dexamethasone as risk-factor for ICU-acquired respiratory tract infections in severe COVID-19

COVID-19; Critical care; DexamethasoneCOVID-19; Cuidados intensivos; DexametasonaCOVID-19; Cures crítiques; DexametasonaPurpose Dexamethasone is the only drug that has consistently reduced mortality in patients with COVID-19, especially in patients needing oxygen or invasive mechanical ventilation. However, there is a growing concern about the relation of dexamethasone with the unprecedented rates of ICU-acquired respiratory tract infections (ICU-RTI) observed in patients with severe COVID-19. Methods This was a multicenter, prospective cohort study; conducted in ten countries in Latin America and Europe. We included patients older than 18 with confirmed SARS-CoV-2 requiring ICU admission. A multivariate logistic regression and propensity score matching (PSM) analysis was conducted to determine the relation between dexamethasone treatment and ICU-RTI. Results A total of 3777 patients were included. 2065 (54.7%) were treated with dexamethasone within the first 24 h of admission. After performing the PSM, patients treated with dexamethasone showed significantly higher proportions of VAP (282/1652 [17.1%] Vs. 218/1652 [13.2%], p = 0.014). Also, dexamethasone treatment was identified as an adjusted risk factor of ICU-RTI in the multivariate logistic regression model (OR 1.64; 95%CI: 1.37–1.97; p < 0.001). Conclusion Patients treated with dexamethasone for severe COVID-19 had a higher risk of developing ICU-acquired respiratory tract infections after adjusting for days of invasive mechanical ventilation and ICU length of stay, suggesting a cautious use of this treatment.This work was supported by Universidad de La Sabana (LFR) and the Spanish Society of Intensive and Critical Care Medicine and Coronary Units (SEMICYUC)

A large accumulation of avian eggs from the Late Cretaceous of Patagonia (Argentina) reveals a novel nesting strategy in Mesozoic birds

We report the first evidence for a nesting colony of Mesozoic birds on Gondwana: a fossil accumulation in Late Cretaceous rocks mapped and collected from within the campus of the National University of Comahue, Neuquén City, Patagonia (Argentina). Here, Cretaceous ornithothoracine birds, almost certainly Enanthiornithes, nested in an arid, shallow basinal environment among sand dunes close to an ephemeral water-course. We mapped and collected 65 complete, near-complete, and broken eggs across an area of more than 55 m2. These eggs were laid either singly, or occasionally in pairs, onto a sandy substrate. All eggs were found apparently in, or close to, their original nest site; they all occur within the same bedding plane and may represent the product of a single nesting season or a short series of nesting attempts. Although there is no evidence for nesting structures, all but one of the Comahue eggs were half-buried upright in the sand with their pointed end downwards, a position that would have exposed the pole containing the air cell and precluded egg turning. This egg position is not seen in living birds, with the exception of the basal galliform megapodes who place their eggs within mounds of vegetation or burrows. This accumulation reveals a novel nesting behaviour in Mesozoic Aves that was perhaps shared with the non-avian and phylogenetically more basal troodontid theropods.Fil: Fernández, Mariela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Patagonia Norte. Instituto de Investigación en Biodiversidad y Medioambiente; ArgentinaFil: Garcia, Rodolfo Andres. Universidad Nacional de Rio Negro. Sede Alto Valle. Instituto de Investigaciones En Paleobiologia y Geologia; ArgentinaFil: Fiorelli, Lucas Ernesto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Regional de Investigaciones Cientificas y Transferencia Tecnológica de Anillaco; ArgentinaFil: Scolaro, Jose Alejandro. Universidad Nacional de la Patagonia "san Juan Bosco"; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; ArgentinaFil: Salvador, Rodrigo B.. Universidade de Sao Paulo. Instituto Quã­mica de Sao Carlos; BrasilFil: Cotaro, Carlos N.. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; ArgentinaFil: Kaiser, Gary W.. Royal British Columbia Museum; CanadáFil: Dyke, Gareth J.. University Of Southampton; Reino Unid

Valorización de las empresas: Unión de Cervecerías Peruanas Backus y Johnston, Molson Coors Beverage Co. y Compañía de Cervecerías Unidas

El presente trabajo de investigación desarrolla la valorización de tres empresas de diferentes países, Unión de Cervecerías Peruana Backus y Johnston de Perú (en adelante “Backus”), Molson Coors Beverage Co. De los Estados Unidos (en adelante “Molson”) y Compañía de Cervecerías Unidas de Chile (en adelante “CCU”). Para realizar la valorización se ha considerado la situación macroeconómica y tendencias de especialistas que han sido marcadas por la modificación significativa del entorno global por la pandemia del COVID-19, así mismo, el tamaño y composición del mercado cervecero de cada uno de los países y sus aspectos globales, y la información financiera de cada una de las empresas. Para el cálculo del valor fundamental, aplicamos el método del flujo de caja descontado ya que este método recoge de mejor forma las expectativas de crecimiento y generación de valor por parte de las empresas, estos flujos fueron descontados a una tasa promedio ponderado de capital aplicando el modelo CAPM y se añadió el valor terminal de la empresa considerando flujos a perpetuidad. Como resultado, el valor por acción de Backus es de 7.32 USD, que se encuentra 34.3% por encima del precio de mercado de 5.6 USD al 13 de mayo 2021, el caso de las acciones de CCU el valor por acción es de 9.20 USD, el cual se encuentra 13.9% por encima del precio de mercado de 8.0 USD al 13 de mayo 2021, por último el valor de acción de Molson es de 69.75 USD, que se encuentra 19.8% por encima del precio de mercado de 58.2 USD al 13 de mayo 2021, por lo tanto la recomendación para las tres empresas es comprar o mantener las acciones debido a que el valor de estas se encuentran subvaluadas con respecto al mercado con un potencial de crecimiento. En cuanto a resultados financieros y el análisis realizado en base a estos se concluye que Backus y Molson mantienen un ciclo de conversión de efectivo negativo, logrando cobrar antes de cumplir con sus obligaciones, luego en cuanto a cobertura de intereses y servicio de deuda, Backus tiene un indicador saludable (>35x en promedio) desde el 2015. Respecto a CCU y Molson Coors, el ratio de cobertura de intereses del último año es de 21x y 1.9x, respectivamente, lo cual los hace menos solventes comparativamente. Finalmente, un escenario de recompra de acciones de Backus tendría un mayor impacto a mediano plazo, ya que se incrementaría los niveles de retorno al accionista y el valor de acción, sin embargo, la alternativa de una recompra de acciones para Molson tiene una ganancia marginal, mientras que en CCU el impacto sobre la valorización y ROE es mínimo y cambiarla no generaría valor al negocio

The Impact of Postnatal Systemic Steroids on the Growth of Preterm Infants: A Multicenter Cohort Study

Postnatal steroids, often used to prevent and treat bronchopulmonary dysplasia, may influence the growth of preterm infants, although data are scarce in the literature. This is a multicenter cohort study including surviving preterm infants <32 weeks at birth (n = 17,621) from the Spanish Neonatal Network SEN1500 database, without major congenital malformations. Linear regression models were adjusted for postnatal steroids, respiratory severity course (invasive mechanical ventilation at 28 days), progression to moderate-severe bronchopulmonary dysplasia (O2 at 36 weeks), length of stay, sex, gestational age and z-scores at birth. A subgroup analysis depending on the timing of administration, ventilation status at 28 days and moderate-severe BPD diagnosis was also performed. Overall, systemic postnatal steroids were not independently associated with poorer weight gain (0.1; 95% CI: -0.05 to 0.2 g/kg/day), linear growth (0; 95% CI: -0.03 to 0.01 cm/week) or head circumference growth (-0.01; 95% CI: -0.02 to 0 cm/week). Patients who received steroids after 28 days or who were not O2 dependent at 36 weeks after having received steroids gained more weight (0.22; 95% CI: 0.04 to 0.4 and 0.2; 95% CI: 0.004 to 0.5 g/kg/day, respectively). Globally, systemic postnatal steroids had no significant adjusted effect on postnatal growth

Predicting risk of cardiovascular disease using retinal OCT imaging

We investigated the potential of optical coherence tomography (OCT) as an additional imaging technique to predict future cardiovascular disease (CVD). We utilised a self-supervised deep learning approach based on Variational Autoencoders (VAE) to learn low-dimensional representations of high-dimensional 3D OCT images and to capture distinct characteristics of different retinal layers within the OCT image. A Random Forest (RF) classifier was subsequently trained using the learned latent features and participant demographic and clinical data, to differentiate between patients at risk of CVD events (MI or stroke) and non-CVD cases. Our predictive model, trained on multimodal data, was assessed based on its ability to correctly identify individuals likely to suffer from a CVD event(MI or stroke), within a 5-year interval after image acquisition. Our self-supervised VAE feature selection and multimodal Random Forest classifier differentiate between patients at risk of future CVD events and the control group with an AUC of 0.75, outperforming the clinically established QRISK3 score (AUC= 0.597). The choroidal layer visible in OCT images was identified as an important predictor of future CVD events using a novel approach to model explanability. Retinal OCT imaging provides a cost-effective and non-invasive alternative to predict the risk of cardiovascular disease and is readily accessible in optometry practices and hospitals

The Deubiquitinating Enzyme Ataxin-3 Regulates Ciliogenesis and Phagocytosis in the Retina

Expansion of a CAG repeat in ATXN3 causes the dominant polyglutamine disease spinocerebellar ataxia type 3 (SCA3), yet the physiological role of ATXN3 remains unclear. Here, we focus on unveiling the function of Ataxin-3 (ATXN3) in the retina, a neurological organ amenable to morphological and physiological studies. Depletion of Atxn3 in zebrafish and mice causes morphological and functional retinal alterations and, more precisely, photoreceptor cilium and outer segment elongation, cone opsin mislocalization, and cone hyperexcitation. ATXN3 localizes at the basal body and axoneme of the cilium, supporting its role in regulating ciliary length. Abrogation of Atxn3 expression causes decreased levels of the regulatory protein KEAP1 in the retina and delayed phagosome maturation in the retinal pigment epithelium. We propose that ATXN3 regulates two relevant biological processes in the retina, namely, ciliogenesis and phagocytosis, by modulating microtubule polymerization and microtubule-dependent retrograde transport, thus positing ATXN3 as a causative or modifier gene in retinal/macular dystrophies

Desarrollo de un benchmark para bases de datos de grafos orientado a consultas de caminos

154 p.A continuación se muestra el desarrollo de un benchmark para bases datos de grafos, el cual se enfoca en la evaluación de consultas de camino. La principal contribución de este trabajo es el estudio y definición de un método que permite una selección adecuada de datos de entrada para la generación de las instancias de consulta ejecutadas por el benchmark. Esto permite que los resultados de desempeño entregados por el benchmark sean comparables, es decir, que los tiempos de ejecución sean similares. De manera específica, primero se estudian diversas consultas de camino, esto con la finalidad de comprender el motivo de su complejidad. Luego, se definen y evalúan de manera empírica diversos métodos de selección de datos de entrada, esto con el objetivo de identificar el método más adecuado. El método seleccionado es comparado con un método tradicional basado en una selección aleatoria de datos de prueba. El método propuesto fue usado para extender un benchmark existente, lo cual implicó una modificación del generador de datos, el generador de operaciones y el evaluador de operaciones. Finalmente, el nuevo benchmark fue evaluado en dos sistemas de gestión de bases de datos de grafos