Linear or Nonlinear Modeling for ENSO Dynamics?

The observed ENSO statistics exhibits a non-Gaussian behavior, which is indicative of the presence of nonlinear processes. In this paper, we use the Recharge Oscillator Model (ROM), a largely used Low-Order Model (LOM) of ENSO, as well as methodologies borrowed from the field of statistical mechanics to identify which aspects of the system may give rise to nonlinearities that are consistent with the observed ENSO statistics. In particular, we are interested in understanding whether the nonlinearities reside in the system dynamics or in the fast atmospheric forcing. Our results indicate that one important dynamical nonlinearity often introduced in the ROM cannot justify a non-Gaussian system behavior, while the nonlinearity in the atmospheric forcing can instead produce a statistics similar to the observed. The implications of the non-Gaussian character of ENSO statistics for the frequency of extreme El Nino events is then examined

Unmanned Aerial Vehicles for Debris Survey in Coastal Areas: Long-Term Monitoring Programme to Study Spatial and Temporal Accumulation of the Dynamics of Beached Marine Litter

Unmanned aerial vehicles (UAVs) are becoming increasingly accessible tools with widespread use as environmental monitoring systems. They can be used for anthropogenic marine debris survey, a recently growing research field. In fact, while the increasing efforts for offshore investigations lead to a considerable collection of data on this type of pollution in the open sea, there is still little knowledge of the materials deposited along the coasts and the mechanism that leads to their accumulation pattern. UAVs can be effective in bridging this gap by increasing the amount of data acquired to study coastal deposits, while also limiting the anthropogenic impact in protected areas. In this study, UAVs have been used to acquire geo-referenced RGB images in a selected zone of a protected marine area (the Migliarino, Massacciuccoli, and San Rossore park near Pisa, Italy), during a long-term (ten months) monitoring programme. A post processing system based on visual interpretation of the images allows the localization and identification of the anthropogenic marine debris within the scanned area, and the estimation of their spatial and temporal distribution in different zones of the beach. These results provide an opportunity to investigate the dynamics of accumulation over time, suggesting that our approach might be appropriate for monitoring and collecting such data in isolated, and especially in protected, areas with significant benefits for different types of stakeholders

Application of a Duration Model in Programs for Prevention of University Attrition

Las prácticas institucionales vinculadas con la prevención de la deserción de una carrera universitaria requieren cada vez más de instrumentos validados que permitan anticipar tal comportamiento. En este sentido han demostrado utilidad decisiva distintos modelos estadísticos generados a partir de información referida a los propios estudiantes, sus hogares y su desempeño académico, entre otros determinantes. Este estudio pretende mostrar la importancia de una serie de determinantes exploradas en otros estudios: el objetivo principal es aplicar un modelo predictivo del riesgo de deserción de estudiantes universitarios a fin de generar resultados de manera temprana y progresivamente más eficaces. El trabajo exhibe la utilidad de los modelos de duración en una muestra de estudiantes presenciales, y la capacidad anticipatoria de los comportamientos de permanencia/deserción en el tiempo, a través de estimaciones de riesgo con un modelo de Cox en cuatro momentos de los primeros meses de universidad.Institutional practices related to the prevention of desertion of university students increasingly require validated instruments in order to anticipate such behavior. In this regard, different statistical models generated from information related to the students themselves, their homes, their academic performance, among other determinants have demonstrated to be of crucial value. This study aims to demonstrate the importance of a series of determinants explored in other studies. The main objective is to apply a dropout rate predictive model with at risk university students in order to generate early and progressively more effective results. The research demonstrates the usefulness of the duration models in a sample of classroom students and the capacity to anticipate behavior of permanence/attrition across time. This was done with risk estimates using the Cox model.Fil: Herrero, Verónica. Universidad Empresarial Siglo Xxi; ArgentinaFil: Merlino, Aldo. Universidad Empresarial Siglo Xxi; ArgentinaFil: Ayllón, Silvia. Universidad Empresarial Siglo Xxi; ArgentinaFil: Escanés, Gabriel Adrián. Universidad Empresarial Siglo Xxi; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones y Estudio sobre Cultura y Sociedad; Argentin

Innovating approaches for scientific education and research in environmental and marine sciences

[EN] Citizen-science can give a valid help to scientific investigation, and this is especially true for environment monitoring programs. However, motivate and enable volunteers in a long-term commitment to a scientific problem represents an essential problem. The presented project is an example on how this long-term commitment can be guaranteed trough an educational path that involves students, not only in data collection but also in problem definition and data analysis. We tried to identify and harmonizing the existing educational plans for improving STEM teaching and learning (STEM is a curriculum for educate students in Science, Technology, Engineering and Mathematics in an interdisciplinary and applied approach, integrating the four disciplines into a cohesive learning path based on real-world applications), prioritizing hands-on learning to increase student interest and engagement. In particular, we describe an example of how two different approaches for educate students on marine sciences can interact in the context of environmental monitoring, applied to problems such as biodiversity, pollution from marine litters, and the the impact of this problem on the marine environmentMioni, E.; Merlino, S. (2015). Innovating approaches for scientific education and research in environmental and marine sciences. En 1ST INTERNATIONAL CONFERENCE ON HIGHER EDUCATION ADVANCES (HEAD' 15). Editorial Universitat Politècnica de València. 401-408. https://doi.org/10.4995/HEAd15.2015.29240140

Mapping of Yucca gloriosa invasion along Mediterranean coastal dunes using unmanned aerial vehicles (UAVs)

Invasive Alien Plants (IAPs) are defined as those species whose introduction and/or spread outside their natural distribution can threaten the biological diversity of an ecosystem. They represent a severe threat to biodiversity and can severely alter the performance of crucial ecosystems such as coastal dunes. Coastal dunes are composed of specialized fauna and flora, converting them into strategic ecosystems due to their unique ecological functions. Coastal dunes are one of the most invaded European environments, with a total flora composed of up to 7% of IAPs. One of these IAPs is Yucca gloriosa L. (Asparagaceae), a homoploid hybrid native plant from the United States of America introduced to Europe for ornamental purposes. For Italy, Y. gloriosa is a typical invasive species related to fixed dunes dominated by Juniperus sp. pl. (with which it competes). Concerning biological invasions, maybe the most effective management strategy is early detection and mapping. In that sense, this work explores and tests the potential of unmanned aerial vehicles (UAVs) for detecting, mapping, and managing the Y. gloriosa invasion along the Mediterranean coastal dunes of a protected area located in Tuscany (Italy). In detail, this work focuses on four aspects: i) determine the suitability of RGB images to map Y. gloriosa, ii) identify the best time of data acquisition, iii) detect changes affecting the occurrence and cover of Y. gloriosa, and iv) propose a set of management actions to preserve a coastal dune ecosystem subjected to plant invasion. The UAV images allowed the generation of ultra-high spatial resolution maps to assess the Y. gloriosa invasion and distribution along the surveyed sandy dunes. The morphological characteristics of this plant – especially at the foliar level – make the invasion of Y. gloriosa particularly suitable for being evaluated and managed using UAV mapping, especially in coastal dunes vegetation that can be a mosaic of different plant communities hard to identify when airborne or satellite images are used. According to the obtained results, the spring season is the perfect time to collect data because light conditions are ideal, with minimal shading effects. Also, due to the peculiar morphology of Y. gloriosa leaves, the timing of data collection seems not crucial for mapping this IAP on coastal dune habitats. Despite the massive eradication action funded by a LIFE project during the period 2005-2009, Y. gloriosa is still present in the protected area and affects the priority habitat of juniper. This might be linked to the fact that Y. gloriosa is a perennial rhizomatous shrub capable of switching its photosynthesis from the C3 to CAM pathway and, therefore, withstand the harsh environmental conditions of dune ecosystems. The early detection using UAVs is the first line of defense against IAPs colonization over any ecosystem. From a conservation and management point of view, this work suggests the development of annual biomonitoring of Y. gloriosa to check its distribution over time and control its spread where it becomes particularly invasive. In this case, one possible strategy will be to keep the IAP in isolated nuclei of plants that are easier to remove with mechanical methods. In a broader view, the study area and the Mediterranean coast must include the ban on introducing non-native species as a strategy, adopting a short-term non-native Management Plan as urgent action

Medición del riesgo de abandono de ingresantes universitarios en educación a distancia

Este trabajo describe cómo se construyeron dos índices de riesgo de abandono desarrollados para prevenir la deserción en Educación Distribuida (modalidad a distancia que incluye algunas instancias de presencialidad).Los índices se denominan IRAP (Índice de Riesgo de Abandono Provisorio) e IRAD (Índice de Riesgo de Abandono Definitivo). El primero se obtiene en base a la medición de tres variables: habilidades verbales, responsabilidad y condición laboral, y se mide antes de que el alumno comience su ciclo lectivo. El segundo índice se obtiene en base a la medición de cinco variables: rendimiento académico, autopercepción como alumno, satisfacción con la Universidad, satisfacción de instancias específicas y compatibilidad trabajo/estudio, que se registran luego del primer semestre de cursado.Los objetivos de este trabajo son:a) describir el comportamiento de las variables que componen el IRAP e IRAD; y b) medir el grado de asociación de cada una con el abandono, a través del seguimiento de una cohorte de alumnos a lo largo de 6 semestres.La metodología desarrollada es cuantitativa. La investigación se llevó a cabo sobre los ingresantes del año 2010, administrándose, vía web, todos los instrumentos de recolección de información.Los principales resultados permiten concluir que la capacidad predictiva de ambos índices aumenta significativamente a lo largo del tiempo. De los alumnos tipificados con IRAP muy alto, abandonó el 70,6% al cabo del sexto período medido. A su vez de quienes estaban tipificados con un IRAD muy alto, abandonó el 88,5% en el mismo período

Deserción en educación a distancia: factores asociados a la elección de modalidad como desencadenantes del abandono universitario

The university distance education emerges as a palliative of inequality of opportunities   overcoming exclusion from access or as a second chance to avoid collage dropouts in traditional face to face programs. The study of the causes of college dropout has been developed from a basic set of theoretical explanatory models, predominantly applied to face to face programs. This work aims to particularly describe the factors that produce dropouts in distance education. This paper summarizes the main theoretical aspects related to college dropout in distance education in order to guide subsequent empirical approaches where the relative importance of each factor is applied to individual cases Among the factors associated with college dropout at distance education are of singular interest those aspects that this model attempts to mitigate in the traditional face to face models.La educación universitaria a distancia emerge como un paliativo frente a la desigualdad de oportunidades, superando la exclusión en el acceso u operando como una segunda oportunidad para casos de abandono de las modalidades universitarias tradicionales. El estudio de las causas de la deserción universitaria se ha desarrollado a partir de un conjunto básico de modelos explicativos teóricos, aplicados predominantemente al ámbito de la educación presencial. Este trabajo está orientado a particularizar los factores que inciden en la deserción en la educación universitaria a distancia. El trabajo se ocupa de sintetizar las principales vertiente teóricas del estudio de la deserción universitaria en educación a distancia, de modo de orientar subsiguientes abordajes empíricos donde se compute la importancia relativa de cada factor en casos concretos. Entre los factores asociados a la deserción universitaria a distancia son de singular interés aquellos aspectos que este modelo intenta mitigar en los modelos presenciales tradicionales

Asociación de variables cognitivas y actitudinales con la deserción en alumnos ingresantes universitarios

La deserción en primer año de la Universidad es el resultado de un proceso complejo en el que participan numerosas variables. En este estudio se toman algunas de las variables más determinantes del abandono de estudios, las cuales se miden en alumnos ingresantes a la UE, desde el año 1998, hasta la fecha. Estas variables son: las habilidades cognitivas verbales, variables referentes a la personalidad, tales como la responsabilidad; un tercer grupo referido a las características sociodemográficas y, como variable conductual, el rendimiento académico de los alumnos en el primer semestre de cursado.El objetivo general de la investigación es relacionar estadísticamente estas variables con la deserción, construir un Índice de Abandono provisorio, para luego poder generar estrategias de retención preventivas, prematuras y eficientes. Para la medición de las variables mencionadas se aplica un test de habilidades cognitivas verbales (DAT), se ha desarrollado y aplicado un nuevo instrumento (CPA), y se ha construido un indicador de rendimiento académico.Por último, en función del perfil de respuestas de los alumnos, agrupándolos por análisis estadísticos multivariados, se obtuvieron clusters o grupos de alumnos que responden de modo similar a los cuestionarios e instrumentos administrados. Estos grupos de alumnos tienen características comunes que permiten identificarlos y atender a su perfil para generar estrategias de retención grupales. Se identificaron cuatro clusters y se describieron sus características distintivas

Urotensin-II Receptor: A Double Identity Receptor Involved in Vasoconstriction and in the Development of Digestive Tract Cancers and other Tumors

Urotensin II and Urotensin-II receptors are important molecular factors that regulate vasoconstriction and all the diseases that are linked to abnormalities in blood pressure regulation (i.e.: hypertension, kidney diseases, cirrhosis etc.). Recently, Urotensin II and its receptor have also been involved in metabolic syndrome, diabetes and schizophrenia. Recent strong findings suggest that Urotensin II and its receptor are involved in the onset and development of different epithelial cancers. Indeed, it was reported that cell growth, motility and invasion in human breast, bladder, prostate, colorectal and glioblastoma cancer cells were regulated by Urotensin II and Urotensin-II receptor axis. This axis also regulated focal adhesion kinase and small Guanosine-5'-triphosphate binding proteins that likely had a role in motility and invasion mediated by Urotensin-II receptor. Additionally, its expression on tumour tissues is variably associated to the prediction of the clinical outcome of the patients and it can be considered an alternative molecular marker to be used as prognostic factor in human cancers. In conclusion, a new weapon in the treatment of human cancers is highlighting a new scenario for the future

The occurrence of paraffin and other petroleum waxes in the marine environment: A review of the current legislative framework and shipping operational practices

Among the various materials that make up marine debris, lumps of petroleum waxes such as paraffin and microcrystalline wax, are regularly found on beaches worldwide, although not included in the current definition of marine litter. Ingestion by marine organisms is occasionally documented in the scientific literature and mass beaching events are frequently reported along the European coasts, with obvious detrimental consequences to the local communities that have to manage the clean-up and disposal of this substance. According to Annex II of the MARPOL regulation, petroleum waxes are classified as "high viscosity, solidifying, and persistent floating products," whose discharge at sea of tank-washing residues is strictly regulated, but currently permitted within certain limits. Starting from the description of a large stranding event occurred along the Italian coasts in 2017, we review the existing knowledge and regulatory framework and urge the relevant authorities to address this issue, showing that wax pollution is creating evident damages to the European coastal municipalities. Pending further investigations on the potential hazard that this kind of pollution is posing to marine ecosystems, we suggest a careful and more stringent revision of the policies regulating discharges of these products at sea