Integration of biophysical connectivity in the spatial optimization of coastal ecosystem services

Ecological connectivity in coastal oceanic waters is mediated by dispersion of the early life stages of marine organisms and conditions the structure of biological communities and the provision of ecosystem services. Integrated management strategies aimed at ensuring long-term service provision to society do not currently consider the importance of dispersal and larval connectivity. A spatial optimization model is introduced to maximise the potential provision of ecosystem services in coastal areas by accounting for the role of dispersal and larval connectivity. The approach combines a validated coastal circulation model that reproduces realistic patterns of larval transport along the coast, which ultimately conditions the biological connectivity and productivity of an area, with additional spatial layers describing potential ecosystem services. The spatial optimization exercise was tested along the coast of Central Chile, a highly productive area dominated by the Humboldt Current. Results show it is unnecessary to relocate existing management areas, as increasing no-take areas by 10% could maximise ecosystem service provision, while improving the spatial representativeness of protected areas and minimizing social conflicts. The location of protected areas was underrepresented in some sections of the study domain, principally due to the restriction of the model to rocky subtidal habitats. Future model developments should encompass the diversity of coastal ecosystems and human activities to inform integrative spatial management. Nevertheless, the spatial optimization model is innovative not only for its integrated ecosystem perspective, but also because it demonstrates that it is possible to incorporate time-varying biophysical connectivity within the optimization problem, thereby linking the dynamics of exploited populations produced by the spatial management regime.Comment: 30 pages, 5 figures, 2 tables; 1 graphical abstract. In this version: numbering of figures corrected, updated figure 2, typos corrected and references fixe

Effects of beaver (Castor canadensis) on the nutrient dynamics of the Southern Beech forest of Tierra del Fuego (Argentina)

Las alteraciones provocadas por las actividades del castor (Castor canadensis) resultan un ejemplo claro de cómo los animales influencian el ecosistema forestal. Los castores modifican la morfología e hidrología de las cursos de agua por la remoción de árboles, construcción de diques y retención de sedimento y materia orgánica en la cuenca. Nosotros estudiamos el efecto de los endicamientos producidos por el castor sobre la dinámica de nutrientes del bosque de Nothofagus de Tierra del Fuego (Argentina) comparando sedimentos y agua de estanques de sitios alterados por castor y no alterados (controles) durante un periodo de 3 años. Las concentraciones de carbono, nitrógeno orgánico e inorgánico (N--nitrato y N--nitrito) y fósforo fueron significativamente mayores en los sedimentos de sitios alterados. Tambien las concentraciones de nitratos y nitritos fueron significativamente más altas en aguas de estanques de castor.Alterations induced by beaver (Castor canadensis) provide a striking example of how the animals influence forest ecosystems. Beavers modify stream morphology and hydrology by removing trees, building dams and retaining sediment and organic material in the stream channel. We studied the effect of beaver impoundments on nutrient dynamics of the native forest (Nothofagus sp.) of Isla Grande of Tierra del Fuego (Argentina), by comparing sediments and pond waters of beaver altered and unaltered sites (controls) over a 3 year period. Concentration of organic carbon, nitrogen, phosphorous, and inorganic nitrogen (nitrate --N and nitrite--N) were significantly greater in sediments of beaver sites. Also nitrites and nitrates were higher in beaver pond waters

Measuring Organization and Asymmetry in Bihemispheric Topographic Maps

We address the problem of measuring the degree of hemispheric organization and asymmetry of organization in a computational model of a bihemispheric cerebral cortex. A theoretical framework for such measures is developed and used to produce algorithms for measuring the degree of organization, symmetry, and lateralization in topographic map formation. The performance of the resulting measures is tested for several topographic maps obtained by self--organization of an initially random network, and the results are compared with subjective assessments made by humans. It is found that the closest agreement with the human assessments is obtained by using organization measures based on sigmoid--type error averaging. Measures are developed which correct for large constant displacements as well as curving of the hemispheric topographic maps. (Also cross-referenced as UMIACS-TR-96-51

Towards convergence of turbulent dynamo amplification in cosmological simulations of galaxies

Our understanding of the process through which magnetic fields reached their observed strengths in present-day galaxies remains incomplete. One of the advocated solutions is a turbulent dynamo mechanism that rapidly amplifies weak magnetic field seeds to the order of ${\sim}\mu$G. However, simulating the turbulent dynamo is a very challenging computational task due to the demanding span of spatial scales and the complexity of the required numerical methods. In particular, turbulent velocity and magnetic fields are extremely sensitive to the spatial discretisation of simulated domains. To explore how refinement schemes affect galactic turbulence and amplification of magnetic fields in cosmological simulations, we compare two refinement strategies. A traditional quasi-Lagrangian adaptive mesh refinement approach focusing spatial resolution on dense regions, and a new refinement method that resolves the entire galaxy with a high resolution quasi-uniform grid. Our new refinement strategy yields much faster magnetic energy amplification than the quasi-Lagrangian method, which is also significantly greater than the adiabatic compressional estimate indicating that the extra amplification is produced through stretching of magnetic field lines. Furthermore, with our new refinement the magnetic energy growth factor scales with resolution following \propto \Dres^{-1/2}, in much better agreement with small-scale turbulent box simulations. Finally, we find evidence suggesting most magnetic amplification in our simulated galaxies occurs in the warm phase of their interstellar medium, which has a better developed turbulent field with our new refinement strategy.Comment: Replaced to match version accepted for publication in MNRAS. 20 pages, 17 figures and 2 appendice

Study of the effects of thermally thin and thermally thick particle approaches on the Eulerian modeling of a biomass combustor operating with wood chips

Two particle treatments, thermally thin and thick, are applied to Eulerian combustion modeling for biomass packed beds and tested through the simulation of an experimental plant. The paper shows the efficiency of the Eulerian approach for large packed beds and tests the behavior of both particle treatments, tested with in-bed and flame temperatures and released volatiles measurements at different locations, which is not common in the literature for a full size boiler. Both approaches are implemented in a model with a comprehensive framework that includes several submodels for the thermal conversion kinetics, bed motion, heat and mass transfer with the gas phase, and gas flow and reaction. Two experiments are performed with wood chips fuels with different moisture contents. The simulations of the two cases result in reasonably good predictions for both particle treatments. The results are similar for higher moisture content and, for the low-moisture test, the bed temperature distribution and reaction fronts are slightly different due to the different predictions of the drying and devolatilization fronts. The volatile measurements show that the T. Thin model results in slightly more accurate predictions than the T. Thick, possibly because the wood chips have a more thermally thin behaviorMinisterio de Ciencia, Innovación y Universidades | Ref. PID2021-126569OB-I00Universidade de Vigo/CISU

Patrones de producción y consumo responsable: La carrera por el logro de los Objetivos de Desarrollo Sostenible (ODS) en mercados emergentes

Since the end of the 20th century, the role of private multinational enterprises (MNEs) has been recognized as critical in implementing increased sustainable production and consumption atterns. Particularly after the creation of the Sustainable Development Goals (SDGs) and the Agenda 2030, this role has increased. In this sense, this paper aims to analyze the measures and actions taken by companies in their contribution to the achievement of the SDG 12. Through the identification of more than 52 metrics in sustainability reports of 854 firms, findings suggest that direct greenhouse gas emissions and indirect greenhouse gas emissions are the most often reported corporate metrics to measure their impact on specific SDGs. This reveals the importance of sustainability actions in emerging market firms as a mechanism to gain legitimacy when operating in foreign markets and as an opportunity to create more sustainable production models.Desde finales del siglo XX, se ha reconocido que el papel de las empresas multinacionales (EMN) privadas es fundamental en el proceso de implementación de patrones de producción y consumo más sostenibles. Especialmente, tras la creación de los Objetivos de Desarrollo Sostenible (ODS) y la Agenda 2030, este papel ha aumentado. En este sentido, este trabajo tiene como objetivo analizar las medidas y acciones tomadas por las empresas en su contribución al logro del ODS 12. Mediante la identificación de más de 52 métricas en los informes de sostenibilidad de 854 empresas, los hallazgos sugieren que las emisiones directas de gases de efecto invernadero y las emisiones indirectas de gases de efecto invernadero son las métricas corporativas con más información para medir su impacto en ODS específicos. Esto revela la importancia de las acciones de sostenibilidad en las empresas de mercados emergentes como mecanismo para ganar legitimidad al operar en mercados externos y como oportunidad para la creación de modelos de producción más sostenibles

Minimal irreversible quantum mechanics. The decay of unstable states

Brownian motion is modelled by a harmonic oscillator (Brownian particle) interacting with a continuous set of uncoupled harmonic oscillators. The interaction is linear in the coordinates and the momenta. The model has an analytical solution that is used to study the time evolution of the reduced density operator. It is derived in a closed form, in the one-particle sector of the model. The irreversible behavior of the Brownian particle is described by a reduced density matrix.Comment: 39 pages, 2 figure

Experiencia de la enseñanza de la tecnología BIM a nivel posgrado en ingeniería

BIM es una tecnología promisoria desde el punto de vista de que contribuye a mejorar el desempeño de los participantes y del proyecto en todas las etapas del ciclo de vida. Sin embargo, uno de los principales impedimentos para su adopción es la falta de un entrenamiento adecuado para desarrollar las habilidades necesarias para explotar la tecnología. En el presente trabajo se expone la experiencia de la enseñanza BIM en un curso de verano (teórico-práctico) de nivel Posgrado en ingeniería, cuyo objetivo fue aprender a crear y utilizar modelos BIM para la planeación, seguimiento y control de proyectos de construcción. La dinámica de la clase consistió en presentaciones teóricas, donde se incluyeron temas acerca de la fragmentación de los proyectos de construcción, usos y estándares BIM, definición del nivel de desarrollo (LOD) y estrategias de implementación de BIM entre otros; además, se utilizaron tutoriales (creados por los profesores), para la generación y uso de los modelos BIM, donde los alumnos aplicaron dichas herramientas en un proyecto final de aproximadamente 3,500 metros cuadrados de construcción. Como conclusión los estudiantes argumentaron que a pesar del corto tiempo con el que se contaba para aprender la metodología BIM, se logró el aprendizaje de la utilización de los principales softwares para la implementación de BIM, además se logró entender los beneficios de estas nuevas tecnologías para la industria de la construcción.BIM is a promising technology from the point of view of improving the performance of the project stakeholders teams and the project itself at all stages of the project´s lifecycle. However, one of the major inhibitors for implementing BIM is the lack of adequate training and skills to take advantage of the technology. This paper describes the experience of teaching the BIM technology in a summer course (theory and practice) at the graduate program of construction engineering, whose goal was to learn how to create and use BIM models for planning, monitoring and control of construction projects. The dynamics of the class consisted of theoretical presentations on topics such as the fragmentation of construction projects, BIM applications and standards, defining the level of development (LOD) and BIM implementation strategies among others; in addition, tutorials for off-class self-learning were created to support the theory exposed in class, then the new skills developed by the students were applied to a capstone project, where students modeled a building approximately 3,500 square meters, including the cost estimation and schedule simulation. At the end of the course the student’s opinion on the course was that despite the short time in which they had to learn the BIM theory and the software for modeling, a successful implementation of BIM was achieved, and they we were able to clearly understand through experience the benefits of the BIM technology for the construction industry

Análise psicométrica e dados normativos da UWES em adolescentes peruanos

Academic engagement is a relevant characteristic to predict successful academic trajectories and school performance; however, there is a lack of validated instruments in Peru for its evaluation. Therefore, the objective of this study was to analyze the psychometric properties of the Utrecht Work Engagement Scale – 9S (UWES-9S) in Peruvian adolescents: internal structure, measurement invariance, association with academic self-efficacy, reliability, and norms. A total of 868 school adolescents (51.728% women; Mage = 14.263; SDage = 1.430) from six schools in the Constitutional Province of Callao (central coast of Peru) were evaluated. In addition to the UWES-9S, the Specific Perceived Self-Efficacy Scale for Academic Situations was used as a measure of self-efficacy. The results show that the UWES-9S is unidimensional and invariant between men and women, although three items were eliminated, resulting in a new version: UWES-6S. Likewise, the association with academic self-efficacy was moderate (r > .50) and norms were obtained for men and women separately. In addition, the reliability indices were satisfactory for both the scores (alpha coefficient and average inter-item correlation) and the construct (omega coefficient > .80). It is concluded that the UWES-6S has adequate psychometric properties for its application in Peruvian adolescents.El engagement académico es una característica relevante para predecir las trayectorias académicas exitosas y el rendimiento escolar; sin embargo, existe una carencia de instrumentos validados en Perú para su evaluación. Por ello, el objetivo de esta investigación fue analizar las propiedades psicométricas de la Utrech Work Engagement Scale – 9S (UWES-9S) en adolescentes peruanos: estructura interna, invarianza de medición, asociación con la autoeficacia académica, confiabilidad y normas. Fueron evaluados 868 adolescentes escolares (51.728% mujeres; Medad = 14.263; DEedad = 1.430) procedentes de seis colegios de la Provincia Constitucional del Callao (costa central del Perú). Además de la UWES-9S se utilizó la Escala de Autoeficacia Percibida Específica para Situaciones Académicas como medida de autoeficacia. Los resultados indican que la UWES-9S es unidimensional e invariante entre hombres y mujeres, aunque se eliminaron tres ítems derivando en una nueva versión: UWES-6S. Asimismo, la asociación con la medida de autoeficacia académica fue moderada (r > .50) y se obtuvo normas para hombres y mujeres por separado. Los indicadores de confiabilidad fueron satisfactorios tanto para las puntuaciones (coeficiente alfa y correlación inter-ítem promedio) como para el constructo (coeficiente omega > .80). Se concluye que la UWES-6S cuenta con propiedades psicométricas adecuadas para su aplicación en adolescentes peruanos.O engagement académico é uma característica relevante para prever trajetórias académicas bem-sucedidas e o desempenho escolar, no entanto, faltam instrumentos validados no Perú para a sua avaliação. Portanto, o objetivo deste estudo foi analisar as propriedades psicométricas da Utrecht Work Engagement Scale – 9S (UWES-9S) em adolescentes peruanos: estrutura interna, invariância de medidas, associação com a autoeficácia académica, confiabilidade e normas. Foram avaliados 868 adolescentes escolares (51.728% mulheres; Midade = 14.263; DPidade = 1.430) de seis colégios da Província Constitucional de Callao (costa central do Perú). Além da UWES-9S, foi utilizada a Escala de Autoeficácia Percebida Específica para Situações Académicas como medida de autoeficácia. Os resultados mostram que a UWES-9S é unidimensional e invariável entre homens e mulheres, embora três itens tenham sido eliminados, resultando numa nova versão: UWES-6S. A associação com a autoeficácia académica foi moderada (r > 0,50) e as normas foram obtidas para homens e mulheres separadamente. Além disso, os índices de confiabilidade foram satisfatórios tanto para as pontuações (coeficiente alfa e correlação média entre itens) quanto para o constructo (coeficiente ómega > .80). Conclui-se que a UWES-6S possui propriedades psicométricas adequadas para sua aplicação em adolescentes peruanos