860 research outputs found

    Precolonial institutions and deforestation in Africa

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    We find that local institutions inherited from the precolonial era continue to play an important role in natural resource governance in Africa. Using satellite image data, we find a significant and robust relationship between deforestation and precolonial succession rules of local leaders (local chiefs). In particular, we find that those precolonial areas where local leaders were appointed by ‘social standing’ have higher rates of deforestation compared to the base case of hereditary rule and where local leaders were appointed from above (by paramount chiefs). While the transmission mechanisms behind these results are complex, we suggest that areas where local leaders were appointed by social standing are more likely to have poorer institutions governing local leadership and forest management.This is the author accepted manuscript. The final version is available from Elsevier via http://dx.doi.org/10.1016/j.landusepol.2015.10.03

    On the Use of the Theory of Critical Distances with Mesh Control for Fretting Fatigue Lifetime Assessment

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    This work analyses the viability of the theory of critical distances (TCD) using mesh control for fretting fatigue lifetime assessment. More than seven hundred sets of simulations were performed by taking seventy different experimental tests reported previously in the literature. The outcome of the present study suggests that the TCD mesh control method can be extended to fretting fatigue problems by the reasonable assumption of setting the right element size proportional to critical distance. In this study, a significant computational time reduction of up to 97% was obtained. Thus, this study provides a simple method to design complex 3D industrial components subjected to fretting fatigue phenomena using finite element analysis efficiently without requiring complex remeshing techniques

    Spontaneous magnetization of aluminum nanowires deposited on the NaCl(100) surface

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    We investigate electronic structures of Al quantum wires, both unsupported and supported on the (100) NaCl surface, using the density-functional theory. We confirm that unsupported nanowires, constrained to be linear, show magnetization when elongated beyond the equilibrium length. Allowing ions to relax, the wires deform to zig-zag structures with lower magnetization but no dimerization occurs. When an Al wire is deposited on the NaCl surface, a zig-zag geometry emerges again. The magnetization changes moderately from that for the corresponding unsupported wire. We analyse the findings using electron band structures and simple model wires.Comment: submitted to PHys. Rev.

    Dise?o del complejo eco tur?stico "La Holgazana" el Espinal, vereda la Caimanera

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    153 p. Recurso Electr?nicoEl trabajo de grado ?Dise?o del complejo eco tur?stico ?La Holgazana?, en la vereda la Caimanera, Espinal, Tolima?; es la respuesta a las insuficiencias del municipio aportando a la creaci?n de empleo, as? mejorando la econom?a del lugar; la preservaci?n del rio magdalena y sus alrededores en el punto del Malec?n de la Caimanera, importantes para el desarrollo tur?stico y medio ambiental ; finalmente el rescate de las tradiciones por medio de espacios dedicados a recordar la memoria de la cultura de la regi?n. Se estudi? la poblaci?n del Espinal desde los diferentes ?mbitos, logrando como resultado una lista de necesidades y cualidades del municipio, por medio de encuestas, entrevistas y an?lisis de planes del lugar. En conclusi?n el complejo eco tur?stico se plante? bajo el concepto de la Identidad, destacando las costumbres y pr?cticas Espinalunas, desarrollando desde todas las perspectivas la condici?n del ?eco? cumpliendo cada uno de los objetivos propuestos.The work of project "Design of the ecotourism complex" La Holgazana ", in the Caimanera town, Espinal, Tolima"; Is the answer to the inadequacies of the borough, contributing to the creation of employment, thus improving the economy of the place; the preservation of the Magdalena River and its surroundings at the point of the Caimanera?s pier. This is important for tourism and environmental development. Finally, it contributes to the rescue of the traditions by means of spaces dedicated to remember the memory of the culture of the region. The Espinal?s people was studied from different scopes. The result was a list of needs and qualities of the township, through surveys, interviews and analysis of local plans. In conclusion, the eco-tourism complex was raised under the concept of Identity, highlighting the customs and Espinal?s practices, developing from all perspectives of the ?eco? fulfilling each of the goals proposed. Keywords: Ecotourism, Identity, Customs, Traditions, Culture

    Spontaneous Magnetization and Electron Momentum Density in 3D Quantum Dots

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    We discuss an exactly solvable model Hamiltonian for describing the interacting electron gas in a quantum dot. Results for a spherical square well confining potential are presented. The ground state is found to exhibit striking oscillations in spin polarization with dot radius at a fixed electron density. These oscillations are shown to induce characteristic signatures in the momentum density of the electron gas, providing a novel route for direct experimental observation of the dot magnetization via spectroscopies sensitive to the electron momentum density.Comment: 5 pages (Revtex4), 4 (eps) figure

    Colchicine blocks tubulin heterodimer recycling by tubulin cofactors TBCA, TBCB and TBCE

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    Research Areas: Cell Biology ; Developmental BiologyColchicine has been used to treat gout and, more recently, to effectively prevent autoinflammatory diseases and both primary and recurrent episodes of pericarditis. The anti-inflammatory action of colchicine seems to result from irreversible inhibition of tubulin polymerization and microtubule (MT) assembly by binding to the tubulin heterodimer, avoiding the signal transduction required to the activation of the entire NLRP3 inflammasome. Emerging results show that the MT network is a potential regulator of cardiac mechanics. Here, we investigated how colchicine impacts in tubulin folding cofactors TBCA, TBCB, and TBCE activities. We show that TBCA is abundant in mouse heart insoluble protein extracts. Also, a decrease of the TBCA/β-tubulin complex followed by an increase of free TBCA is observed in human cells treated with colchicine. The presence of free TBCA is not observed in cells treated with other antimitotic agents such as nocodazole or cold shock, neither after translation inhibition by cycloheximide. In vitro assays show that colchicine inhibits tubulin heterodimer dissociation by TBCE/TBCB, probably by interfering with interactions of TBCE with tubulin dimers, leading to free TBCA. Manipulation of TBCA levels, either by RNAi or overexpression results in decreased levels of tubulin heterodimers. Together, these data strongly suggest that TBCA is mainly receiving β-tubulin from the dissociation of preexisting heterodimers instead of newly synthesized tubulins. The TBCE/TBCB+TBCA system is crucial for controlling the critical concentration of free tubulin heterodimers and MT dynamics in the cells by recycling the tubulin heterodimers. It is conceivable that colchicine affects tubulin heterodimer recycling through the TBCE/TBCB+TBCA system producing the known benefits in the treatment of pericardium inflammation.info:eu-repo/semantics/publishedVersio

    Amaranthus kloosianus Hunz.

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    MaimarápublishedVersio

    Plantas arom?ticas que vivifican mi ser, la yerbabuena, limoncillo, cidr?n, or?gano y manzanilla

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    63 P?ginasRecurso Electr?nicoLa sociedad actual frecuentemente se desvincula de los conocimientos te?rico-pr?cticos referentes al empleo de las plantas arom?ticas, olvidando los beneficios en los ?mbitos educativos, familiar y social; como objetivo central se definen estrategias pedag?gicas que favorezcan el reconocimiento y comprensi?n del beneficio con la utilizaci?n de cinco plantas arom?ticas: yerba buena, limoncillo, cidr?n, or?gano y manzanilla, en los estudiantes del CER Socorro de Sabanas del Municipio de Santa Fe de Antioquia y de la I.E. Atanasio Girardot del Municipio de Bello; con Metodolog?a de Investigaci?n Acci?n (IA) considerando los intereses del colectivo frente a la utilizaci?n y beneficios de las plantas arom?ticas, sus efectos curativos, y su empleo en emplastos, bebidas, ba?os, laxantes, entre otros usos. Se cumple con el perfil de la Licenciatura en Educaci?n B?sica establecido por la Universidad del Tolima; se aprecian hallazgos referidos a un grado de concientizaci?n respecto al empleo y uso de las plantas arom?ticas. Result? gratificante para la poblaci?n beneficiaria la adquisici?n de las nociones impartidas, la distribuci?n de macetas y el disfrute de tisanas en cada encuentro para la recolecci?n de informaci?n y socializaci?n final de los resultados. Es gratificante, como evidencia del trabajo y para afianzar los saberes tradicionales, enriquecidos con el enfoque te?rico-pr?ctico de la propuesta, la elaboraci?n y distribuci?n del M?dulo Sembramos la salud. Amerita resaltar la recuperaci?n del patrimonio generado a trav?s de los conversatorios con la comunidad adulta y los educadores de ambas instituciones educativas vinculadas.ABSTRACT. Today's society often split with the theoretical and practical knowledge regarding the use of herbs , forgetting the benefits in education , family and social spheres; like the central objective of teaching strategies that encourage the recognition and understanding of the benefit with the use of five aromatic plants: good grass, lemongrass, Cidr?n , oregano and chamomile in CER students Relief Sheets Municipality of Santa Fe de Antioquia and EI Atanasio Girardot Municipality of Bello ; Research Methodology in Action ( IA ) considering the interests of the collective over the use and benefits of herbs , their healing effects , and their use in plasters, drinks, bathrooms, laxatives, among other uses. It complies with the profile of the Bachelor of Primary Education established by the University of Tolima; findings related to a degree of awareness regarding the employment and use of aromatic plants are appreciated. Gratifying for the acquisition target population received notions, the distribution of pots and enjoys teas at each meeting for the collection of information and socialization of end results. It is gratifying, as evidence of the work and to strengthen traditional knowledge, enriched with theoretical and practical approach of the proposal, development and distribution of sow health module. Amerita highlight the recovery of assets generated through community conversations with adult educators and educational institutions both linked.INTRODUCCI?N 15 1. ANTECEDENTES DEL PROBLEMA 16 1.1. T?TULO DEL TRABAJO 16 2. JUSTIFICACI?N 19 3. FORMULACION DEL PROBLEMA 20 3.1 PREGUNTA MOVILIZADORA 20 3.2 PROBLEMA 20 4. OBJETIVOS 22 4.1 OBJETIVO GENERAL 22 4.2 OBJETIVOS ESPEC?FICOS 22 5. MARCO GENERAL 23 5.2 MARCO CONTEXTUAL 24 5.2.1 Contexto comunitario 24 5.3 COMPONENTE PEDAG?GICO 27 5.3.1 Categor?as generales cultura 27 5.4 COMPONENTE ESPEC?FICO DE ESTUDIO 29 5.4.1 Categor?as espec?ficas 29 5.4.2 Plantas arom?ticas 29 5.4.3 Formas de uso 31 5.4.4 Beneficios 32 5.5 CONSOLIDADO DE LAS PLANTAS OBJETO DE ESTUDIO 32 6. DISE?O METODOL?GICO DEL PROCESO INVESTIGATIVO 40 6.1 POBLACI?N BENEFICIARIA 40 6.2 METODOLOG?A DE TRABAJO 41 6.3 UNIVERSO Y MUESTRA 41 6.4 TIPO DE ESTUDIO 41 6.5 ?REA DE ESTUDIO 42 6.6 PROCEDIMIENTOS DEL DISE?O METODOL?GICO 43 6.7 ESTRATEGIAS DE TRABAJO 43 6.8 INSTRUMENTOS PARA LA RECOLECCI?N DE LA INFORMACI?N 44 7. AN?LISIS DE LA INFORMACI?N 45 7.1 ACTIVIDADES POR DESARROLLAR 45 7.1.1 Etapa inicial 45 7.1.2 Etapa de ejecuci?n 46 7.1.3 Etapa de finalizaci?n 46 8. CRONOGRAMA 47 9. PRESUPUESTO GLOBAL DE LA PROPUESTA 50 10. RECURSOS 53 11. CONCLUSIONES 54 RECOMENDACIONES 55 REFERENCIAS 5
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