355 research outputs found

    Redefining Roles, Responsibilities, and Authority of School Leaders

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    Addresses the core challenges faced by principals and other school leaders faced with high expectations and accountability and inconsistent or limited support, based on current research literature in the field

    Civically Engaged and Inclusive Pedagogy: Facilitating a multidisciplinary course on human trafficking

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    For university instructors who teach human trafficking as a comprehensive course, design decisions often begin with determining scope, disciplinary orientation, and learning goals. Further decisions involve pedagogical approaches and how to best support and sustain student learning. With civic engagement principles, universities can situate themselves within local anti-trafficking initiatives by offering courses to expand organisational capacities to end human trafficking. Using Human Trafficking 4160 at Metropolitan State University of Denver as an example, this paper provides key design questions to create a civically-engaged multidisciplinary course, partnered with agencies statewide, and equipped to support students primed for social justice and systems change. It offers suggestions for community partnerships to deliver content and co-create learning activities. It also provides pedagogical techniques to facilitate inclusive, trauma-informed learning spaces

    Allocating Resources and Creating Incentives to Improve Teaching and Learning

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    Offers insights from scholarly literature, related theory, and practical activities to inform the efforts of policymakers, researchers and practitioners to allocate resources and create incentives that result in powerful, equitable learning for all

    Additional insights to EC7 from the application of reliability-based design methods: the case of debris flow protection structures

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    Debris flows are dangerous natural processes that cause extensive damages to infrastructures and urbanized areas and can lead to loss of human lives. Their unpredictability, their extremely high motion and their magnitude are the main causes of these harms. Mitigation measures are fundamental for reducing the associated risk and protecting infrastructures in mountainous areas. Their design is still an open issue: there are many formulations to evaluating impact pressure. Moreover, the uncertainties in the determination of flow characteristics (velocity and thickness) are significantly high and difficult to quantify. In the European Union, the design of any type of structures involved in rock mechanics field must comply with EN-1997 Geotechnical Design (CEN 2004) (EC7). For debris flow countermeasures, EC7 requirements are very difficult to apply in practice since partial safety factors are not provided for these phenomena. However, the basic philosophy of reliability-based design (RBD), as defined in EN1990 (CEN 2002) may be a suitable and complementary approach to provide geotechnical structures with a uniform probability of failure. Reliability Based Design (RBD) can provide additional insights to EC7 design and can be applied when partial factors have still to be proposed (by EC7) to cover uncertainties of less common parameters, as in case of debris flow countermeasures. This paper presents an analysis of the advantages and limitations on the applicability of RBD approach to debris flow countermeasures, by using the first-order reliability method (FORM). In particular, data availability, the possibilities for analysing data in a statistical framework and the choice of performance function are the main limitation of the method, which force to make assumptions regarding statistical distribution of the considered parameters. A sensitivity analyses, comparing different equations, commonly used for debris flow impact pressure estimation, were performed for quantifying the effect of the selected performance function on the RBD results

    Reliability-based design for debris flow barriers

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    In the European Union since 2010, the design of any type of structures must comply with EN-1997 Geotechnical Design (CEN 2004) (EC7) referring to engineering projects in the rock mechanics field. However, the design of debris flow countermeasures in compliance with EC7 requirements is not feasible: EC7 uses partial safety factors for design calculations, but safety factors are not provided for phenomena such as debris flows and rock falls. Consequently, how EC7 can be applied to the design of debris flow barriers is not clear, although the basic philosophy of reliability-based design (RBD), as defined in EN1990 (CEN 2002) and applicable to geotechnical applications, may be a suitable approach. However, there is insufficient understanding of interactions between debris flows and structures to support RBD application to debris flow barrier design, as full-scale experimental data are very limited and difficult to obtain. Laboratory data are available but they are governed by scale effects that limit their usefulness for full-scale problems. The article describes an analysis, using the first-order reliability method (FORM), of two different datasets, one obtained through laboratory experiments and the other reflecting historical debris flow events in the Jiangjia Ravine (China). Statistical analysis of laboratory data enabled a definition of the statistical distributions of the parameters that primarily influence debris flow and barrier interactions. These statistical distributions were then compared to the field data to explore the links between flume experiments and full-scale problems. This paper reports a first attempt to apply RBD to debris flow countermeasures, showing how the choice of the target probability of failure influences the barrier design resistance value. An analysis of the factors governing debris flows highlights the applicability and limitations of EN1990 and EN1997 in the design of these rock engineering structures

    SilvAdapt.Net: A Site-Based Network of Adaptive Forest Management Related to Climate Change in Spain

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    Adaptive forest management (AFM) is an urgent need because of the uncertainty regarding how changes in the climate will affect the structure, composition and function of forests during the next decades. Current research initiatives for the long-term monitoring of impacts of silviculture are scattered and not integrated into research networks, with the consequent losses of opportunities and capacity for action. To increase the scientific and practical impacts of these experiences, it is necessary to establish logical frameworks that harmonize the information and help us to define the most appropriate treatments. In this context, a number of research groups in Spain have produced research achievements and know-how during the last decades that can allow for the improvement in AFM. These groups address the issue of AFM from different fields, such as ecophysiology, ecohydrology and forest ecology, thus resulting in valuable but dispersed expertise. The main objective of this work is to introduce a comprehensive strategy aimed to study the implementation of AFM in Spain. As a first step, a network of 34 experimental sites managed by 14 different research groups is proposed and justified. As a second step, the most important AFM impacts on Mediterranean pines, as one of the most extended natural and planted forest types in Spain, are presented. Finally, open questions dealing with key aspects when attempting to implement an AFM framework are discussed. This study is expected to contribute to better outlining the procedures and steps needed to implement regional frameworks for AFMA.J. Molina is beneficiary of an “APOSTD” fellowship (APOSTD/2019/111) funded by the Generalitat Valenciana. M. Moreno-de las Heras is beneficiary of a Serra Hunter fellowship (UB-LE-9055) funded by the Generalitat de Catalunya. F.J. Ruiz-Gómez is supported by a postdoctoral fellowship of the Junta de Andalucía (Sevilla, Spain), and the European Social Fund 2014–2020 Program (DOC_0055). The authors received national and international funding through the following projects: SILVADAPT.NET (RED2018-102719-T), ESPECTRAMED (CGL2017-86161-R), Life-FOREST CO2 (LIFE14 CCM/ES/001271), ALTERACLIM (CGL2015-69773-C2-1-P), INERTIA (PID2019-111332RB-C22-BDV), CEHYRFO-MED (CGL2017-86839-C3-2-R), DEHESACLIM (IB16185), RESILIENTFORESTS (LIFE17 CCA/ES/000063), Rhysotto (PID2019-106583RB-I00), AGL2017-83828- C2-2-R, RTI2018-096884-B-C31, ESPAS (CGL2015-65569-R), and caRRRascal (RTI2018-095037-B-I00) : We thank the financial support from the “Ministerio de Ciencia e Innovación -Redes de Investigación 2018, Programa Estatal de Generación de Conocimiento y Fortalecimiento Científico y Tecnológico del Sistema de I + D + I

    Growth trends and sensitivity to climate of declining Mediterranean open woodlands exhibiting widespread mortality in Southern Spain

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    We present two chronologies of dead and weakened Quercus ilex trees from declining open woodlands of Southern Andalusia and discuss climate's implication in the current widespread mortality in these ecosystems. Basal area increments were used to find out periods of growth decline preceding death. Absent rings became frequent since the 1970s, coinciding with increasing drought. Negative pointer years matched dry years and became more pronounced in the last decades. Growth was correlated with the annual Palmer Drought Severity Index and precipitations from previous October to May. Mean sensitivity increased recently, ranging between high values (0.35-0.5). Correlations with spring temperatures turned from positive to negative, positive correlations with current autumn precipitation arose whereas significant positive correlations with summer precipitations were no longer observed. These changes could suggest modifications on tree phenology. Intensively-used Mediterranean open woodlands of Southern Andalusia are vulnerable and the current dying process suggests that they are unlikely to overcome increasing stress climatic conditions

    Análisis de vigas con materiales piezoeléctricos

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    Una de las aplicaciones más importantes de las estructuras inteligentes es la modelar el comportamiento. El objetivo de este Trabajo Fin de Grado es analizar la capacidad de control que tienen los materiales inteligentes con respecto a una estructura sometida a requerimientos externos. Se va a realizar un estudio analítico del comportamiento de una viga de material compuesto, de tipo laminado, en el que además habrá láminas de material piezoeléctrico. Se estudiará la capacidad de control que tienen estas láminas sobre el conjunto, introduciendo un campo eléctrico variable a lo largo del espesor del laminado, que estará siendo a su vez sometido a cargas externas. Se probarán también distintos laminados para ver la influencia de la posición de estas láminas en el resultado final. Además, se introducirá una variación de temperaturas entre la cara superior y la inferior para analizar los efectos térmicos a los que la viga dará lugar. También se ha llevado a cabo un estudio del efecto de ambos campos a la vez. Estos campos podrán tener una distribución lineal o cúbica a lo largo del espesor. El objetivo fundamental de este trabajo era el de alcanzar las expresiones más generales posibles de este problema, para ello se han utilizado las hipótesis de Kirchhoff combinas con la Teoría Clásica del Laminado.Ingeniería en Tecnologías Industriale

    Evaluation of Strength and Deformability of Soft Sedimentary Rocks in Dry and Saturated Conditions Through Needle Penetration and Point Load Tests: A Comparative Study

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    The preparation of standardized soft rock specimens to perform unconfined compressive strength (UCS) tests is typically difficult, expensive and time-consuming. Needle penetration test (NPT) was originally developed in Japan as an alternative for the indirect estimation of UCS of soft rocks. The needle penetrometer is a simple, portable and non-destructive testing device that measures applied load and penetration depth for the rock to calculate the needle penetration index (NPI). A complimentary, portable and widely used destructive test is the point load test (PLT), which measures regular and irregular specimens by the application of a concentrated load using two coaxial conical platens that yield the point load strength index (IS(50)). We investigated and compared the NPT and PLT in terms of measuring changes induced by water saturation and obtaining UCS and the static Young’s modulus (Est) for dry and saturated soft sedimentary rocks. The results point to significant correlation functions from which to infer UCS and Est in terms of NPI and IS(50) in dry and saturated soft rocks. Furthermore, both NPT and PLT are suitable tests for evaluating changes in strength and deformability induced by water saturation. We also found a good correlation between the NPI and Is(50).This research was supported by the Vice-rector of Research and Knowledge Transfer of the University of Alicante through predoctoral grant FPUUA53-2018 and projects UAUSTI18-21 and UAEEBB2018-09

    Anti-inflammatory and anti-arthritic activities of glycosylated flavonoids from syzygium jambos in edematogenic agent-induced paw edema in mice

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    Two glycosylated flavonoids, the quercetin-3-O-β-D-xylofuranosyl-(1 → 2)-α-l-rhamnopyranoside and myricetin-3-O-β-d-xylofuranosyl-(1 → 2)-α-l-rhamnopyranoside, were isolated from the CH2Cl2/MeOH fraction of Syzygium jambos (L.) Alston, Myrtaceae. The structures of these compounds were elucidated by spectroscopic means. The cytotoxicity of the compounds was evaluated against the RAW 264.7 cell lines by the lactate dehydrogenase assay. All analyzed compounds were less cytotoxic than the positive control (actinomycin D, CC50 = 0.008 μM). The anti-inflammatory and anti-arthritic activities were evaluated by measuring inflammatory parameters in murine models. The two glycosylated flavonoids inhibited the production of tumor necrosis factor-α in RAW 264.7 cell line with IC50 of 1.68 and 1.11 μM, respectively. In addition, all flavonoids decreased the levels of tumor necrosis factor-α, C-reactive protein, and fibrinogen at a dose of 5 mg/kg in murine modelsThis work was supported by the National Herbarium of Bolivia and the Fundación de la Universidad Autónoma de Madrid (FUAM
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