686 resultados para 13200-073
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Using the one-loop Coleman-Weinberg effective potential, we derive a general analytic expression for all the derivatives of the effective potential with respect to any number of classical scalar fields. The result is valid for a renormalisable theory in four dimensions with any number of scalars, fermions or gauge bosons. This result corresponds to the zero-external momentum contribution to a general one-loop diagram with N scalar external legs. We illustrate the use of the general result in two simple scalar singlet extensions of the Standard Model, to obtain the dominant contributions to the triple couplings of light scalar particles under the zero external momentum approximation.
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Portugal, no intuito de alcançar metas ambientais e económicas a que se propôs, e de reduzir a dependência das importações de energia, tem aumentado o investimento em eletricidade produzida a partir de energias renováveis (FER-E). Apesar do consenso em torno da sua utilização, as energias renováveis deparam-se com barreiras de várias ordens que dificultam a sua difusão no mercado. A atuação do Estado neste enquadramento passa por criar modelos de promoção da FER-E. A maioria dos países da União Europeia, incluindo Portugal, aplica as tarifas feed-in (FIT) como instrumento central de suporte à FER-E, inserido num modelo de apoio que contempla outros parâmetros de construção considerados críticos para o seu sucesso. No seguimento do estágio realizado na empresa Senvion Portugal a presente tese explora os programas e modelos de apoio às FER-E em Portugal, nomeadamente as que se referem à energia eólica. Bem como os trabalhos realizados com as equipas de O&M e a realização de um estudo de viabilidade económica da substituição de aerogeradores no parque eólico de Picos Verdes II.
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Kepa Fernández de Larrinoa (ed.)
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Background: Passive smokers are involuntarily exposed to cigarette or tobacco smoke and as known, inhalation of environmental tobacco smoke is a serious threat. There is little information about the effect of passive smoking on salivary markers and periodontal indices. Objectives: This study investigated the effect of passive smoking on lactoferrin and AST in 12 - 15 years old children and adolescents. Patients and Methods: This case-control analytic correlation type study with no-convenience random sampling method was performed on 160 children aged 12 - 15 who had smokers in their families. The eligible children were divided into two equal groups; 80 cot+ children as case group and 80 cot– children as control group, matched according to age, sex and plaque index. Plaque index was obtained from all subjects. 2 cc unstimulated salivary samples were collected by spitting method. The collected specimens were tested by lactoferrin and AST kits in biochemistry were measured on the day of sampling laboratory. Gingival index Loe and Silness (GI) and Probing Pocket Depth (PPD). Results: Mean and Standard Deviation of PPD and GI was 2.01 ± 0.077 and 1.53 ± 0.055 in experimental group and 1.93 ± 0.073 and 1.49 ± 0.046 in control group respectively (P < 0.001). The Mean and Standard Deviation parameters of lactoferrin and AST, in the experimental group was 38.66 ± 25.15 and 13.45 ± 6.33 and in the control group 10.18 ± 6.82 and 6.53 ± 2.65 group, respectively (P < 0.001). Conclusions: Passive smoking can be effective on inflammatory process of periodontal and salivary biomarkers related to inflammation. Lactoferrin was 11 - 104 in case group and 0.5 - 38 in control group. Aspartat aminotransferase in case group was 2.64 - 30.43 and in control group it was 2.16 - 12.02.
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The response regulator RpaB (regulator of phycobilisome associated B), part of an essential two-component system conserved in cyanobacteria that responds to multiple environmental signals, has recently been implicated in the control of cell dimensions and of circadian rhythms of gene expression in the model cyanobacterium Synechococcus elongatus PCC 7942. However, little is known of the molecular mechanisms that underlie RpaB functions. In this study we show that the regulation of phenotypes by RpaB is intimately connected with the activity of RpaA (regulator of phycobilisome associated A), the master regulator of circadian transcription patterns. RpaB affects RpaA activity both through control of gene expression, a function requiring an intact effector domain, and via altering RpaA phosphorylation, a function mediated through the N-terminal receiver domain of RpaB. Thus, both phosphorylation cross-talk and coregulation of target genes play a role in the genetic interactions between the RpaA and RpaB pathways. In addition, RpaB∼P levels appear critical for survival under light:dark cycles, conditions in which RpaB phosphorylation is environmentally driven independent of the circadian clock. We propose that the complex regulatory interactions between the essential and environmentally sensitive NblS-RpaB system and the SasA-RpaA clock output system integrate relevant extra- and intracellular signals to the circadian clock.
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n decentralised rural electrification through solar home systems, private companies and promoting institutions are faced with the problem of deploying maintenance structures to operate and guarantee the service of the solar systems for long periods (ten years or more). The problems linked to decentralisation, such as the dispersion of dwellings, difficult access and maintenance needs, makes it an arduous task. This paper proposes an innovative design tool created ad hoc for photovoltaic rural electrification based on a real photovoltaic rural electrification program in Morocco as a special case study. The tool is developed from a mathematical model comprising a set of decision variables (location, transport, etc.) that must meet certain constraints and whose optimisation criterion is the minimum cost of the operation and maintenance activity assuming an established quality of service. The main output of the model is the overall cost of the maintenance structure. The best location for the local maintenance headquarters and warehouses in a given region is established, as are the number of maintenance technicians and vehicles required.
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8 documentos : ilustraciones, fotografías.
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Este trabajo de grado tiene por objetivo realizar una revisión de literatura que dé cuenta de las características conceptuales del duelo que viven los familiares de los desaparecidos, en un contexto de desaparición forzada de personas como ilícito internacional de los derechos humanos. Para ello se exploraron libros de consulta reconocidos en el tema, artículos de revistas indexadas de los últimos diez años, y jurisprudencia de la Corte Interamericana de Derechos Humanos de casos de desapariciones forzada. Se presenta la definición de la desaparición forzada como ilícito internacional en DDHH, una categorización de víctimas, el desarrollo del concepto de duelo general y para estos casos y su aplicabilidad a los casos de la Corte IDH. Se encontró que los hallazgos dados por la teoría son aplicados en los dictámenes de esta corte, con un discurso de reivindicación de derechos y reparación integral. Se recomiendan futuras investigaciones en propuestas terapéuticas.
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Colombia atraviesa un proceso de desmovilización y una de las metas es la reintegración laboral, entendida como el proceso a través del cual las personas que han hecho parte de un grupo armado ilegal obtienen un empleo y se insertan definitivamente a la sociedad. El presente estudio tiene como objetivo fundamental comprender las actitudes de un grupo de tres directivos hacia la vinculación laboral de las personas en proceso de reintegración laboral (PPR), mediante un diseño cualitativo. Para ello, se llevó a cabo una serie de entrevistas semiestructuradas a una muestra de tres directivos del sector público y privado. La información obtenida se analizó mediante un proceso de codificación axial. Los resultados obtenidos evidencian que las actitudes de los tres empresarios frente a la contratación de personas en proceso de reintegración laboral, pueden ser positivas o negativas. Así mismo, una de las actitudes predominantes, son la evaluación de creencias y prejuicios de los empresarios frente al proceso de integración laboral, estos son: la incertidumbre frente al desempeño laboral del PPR, la falta de dedicación por parte del PPR, los posibles conflictos laborales y la dificultad de relacionamiento del PPR. En conclusión, el modelo del comportamiento organizacional juega un papel muy importante, dado que abarca los elementos que influyen y determinan la construcción de las actitudes. Estas guían la evaluación de conductas que pueden ser a favor o en contra, de diversos ámbitos del proceso de contratación de personas desmovilizadas.
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Background Entrepreneurship has been considered essential to create value, being a powerful driver of economic and social development. Academy must invest in the development of entrepreneurial skills in students ("Entrepreneurial Academy"). Objective: To analyse the psychometric proprieties of the EMQ-Entrepreneurial Motivations Questionnaire. Methods Sample: 6,532 students from 17 polytechnic Institutes of Portugal. Measure: EMQ, composed by measures of Entrepreneurial motives for the business, Entrepreneurial influences, and Support Services. Results Exploratory factor analysis (EFA) for Entrepreneurial-Motives-for-thebusiness (KMO = .921, X2 = 54387.94, p < .001) extracted 4 factors, explaining 53.81 % of variance (EV): F1-Family security (19.92 % EV; M= 4.07, SD = 0.67), F2-Prestige (14.60 % EV; M= 3.25, SD = 0.75), F3- Independence (13.13 % EV; M= 3.33, SD = 0.75), and F4-Realization of an opportunity (11.15 % EV; M= 4.08, SD = 0.56). This factorial structure was supported by Confirmatory factor analysis (CFA), with an acceptable fit: RMSEA = .084. EFA of Entrepreneurial-Influences (KMO = .916, X2 = 60584.93, p < .001), extracted 4 factors, EV 60.08 %: F1-Resources availability (21.25 % EV; M= 3.86, SD = 0.68), F2-Stable customers and incentives (19.70 % EV; M= 3.82, SD = 0.65), F3-Social and economic instability (11.11 % EV; M= 2.96, SD = 1.06), and F4-Opportunities in the sector and residence area (8.03 % EV; M= 3.29, SD = 0.95). This factorial structure was supported by CFA, with an acceptable fit: RMSEA = .073. EFA of Support-Services (KMO = .995, X2 = 57311.43, p < .001) extracted 2 factors, EV 58.43 %: F1-Financial support (32.59 % EV; M= 3.93, SD = 0.69) and F2-Prestige (25.84 % EV; M= 3.95, SD = 0.65). This factorial structure was supported by CFA, with an acceptable fit: RMSEA = .090. The health group showed scores mostly above global average in factors. Conclusions EMQ showed adequate psychometric properties. The instrument is useful for measuring entrepreneurships motivations in health.
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O fator cobertura e manejo do solo (fator C da Equação Universal de Perda de Solo- EUPS) é um dos mais importantes na redução das perdas de solo por erosão hídrica. Com objetivo de avaliar as razões de perda de solo (RPS) e o fator C, conduziu-se um experimento sob chuva natural em um Cambissolo Húmico alumínico léptico, com declividade média de 0,102 m m-1, em Lages, SC, no período de novembro de 2002 a outubro de 2005, compreendendo seis ciclos culturais. Os parâmetros foram avaliados em cinco estádios, com base na cobertura do solo pelo dossel das plantas. Foram estudados três sistemas de manejo do solo: aração + duas gradagens (PC), escarificação + uma gradagem (CM) e semeadura direta (SD), submetidos a sucessão soja (Glycine max) e trigo (Triticum aestivum L.), além de um tratamento adicional, com aração + duas gradagens sem culturas (SC). As RPS e os fatores C, variaram quanto aos ciclos, estádios das culturas e sistemas de manejo do solo. A SD reduziu as RPS, em 85% e 48% em relação ao PC e CM, respectivamente, durante os cultivos de soja e em 60% e 55% nos cultivos de trigo. Na média dos três anos de estudo, os valores do fator C, foram de 0,073 (PC), 0,016 (CM) e 0,007 (SD) Mg ha Mg-1 ha-1 durante os cultivos de soja e 0,126 (PC), 0,083 (CM) e 0,035 (SD) Mg ha Mg-1 ha-1 durante os cultivos de trigo. Para a sucessão de culturas soja-trigo, os valores do fator C foram de 0,198, 0,099 e 0,042 Mg ha Mg-1 ha-1, para PC, CM e SD, respectivamente.