886 resultados para Other areas of applied and interdisciplinary physics


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Este estudo tem como objetivo descrever o método de história de vida, bem como a história de vida através da oralidade como importantes métodos a serem utilizados nas investigações em Relações Públicas. O método de história de vida é parte da abordagem biográfica, apresentando os conceitos-chave que fazem parte dos métodos e pontos de partida para uma investigação com o profissional de Relações Públicas decorrentes da aplicação dos métodos. O estudo incide sobre a análise das narrativas contadas pelos profissionais de Relações Públicas tendo por base a sua própria “História de Vida”. Centra-se inicialmente no “como”, no “porquê” e no “quando” de uma profissão vistos através da “História Oral de Vida” dos seus profissionais. Está assente em “Como os profissionais chegaram ao exercício da atividade de Relações Públicas?”, “O porquê de seguirem esta escolha?” e “Quando seguiram esta escolha?”. A História Oral de Vida tem sido aplicada noutras áreas, agora sendo relevante para trazer à tona as narrativas dos profissionais de Relações Públicas. A valorização da narrativa pessoal/profissional dos praticantes de Relações Públicas na constituição do profissional, para que se possa estudá-lo para além das organizações. Um dos objetivos relevantes é a possível caracterização da escolha profissional e até que ponto pode contribuir-se para a formação de outros profissionais da área. O papel central do profissional de Relações Públicas que habitualmente fala em nome de uma organização, passa a ser posto à parte para que o profissional seja o sujeito-narrador da sua própria história. O estudo salienta a importância dos profissionais de Relações Públicas através da relevância dada às narrativas. Ao fazer-se a “História Oral de Vida” estamos a trazer à área um novo contributo para aprofundar o conhecimento sobre a atividade.

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In the present work, we studied a common outbreaking Lepidoptera species in Portuguese pine stands – Thaumetopoea pityocampa (Den. & Schiff.) - and one of its potential predators – Parus major (L.). The population dynamics of the immature stages of the Lepidoptera was studied in several types of Pinus pinaster (Aiton) plantations in three different areas: Setúbal Peninsula, Abrantes and National Pine Forest of Leiria. Location and plantation structure was the most important factors determining population density of T. pityocampa. Setubal and Abrantes was highly susceptible to attacks by the Lepidoptera, whereas Leiria had lower densities. Young and homogeneous pine stands was more susceptible to attacks than older and more heterogeneous pines stands. However, a desynchronized population of T. pityocampa, in which the larvae develops during summer instead of during winter, reached high densities also in Leiria. The impact of several mortality factors and climatic conditions on the immature stages of the insect (eggs and larvae), in normal and desynchronized populations are discussed, as well as possible evolutionary implications of the sudden appearance of the new version of T. pityocampa. The break of the pupa diapause and adult emergence times the annual life cycle of this insect. Adults from the desynchronized population emerged earlier than adults from the normal population, which in turn determined the change in the larvae development period. Different factors, potentially affecting the timing of adult emergence in both normal and abnormal populations are also discussed. To study P. Major, nest-boxes were placed in the areas of Setúbal and Leiria and they were monitored during three seasons. The nest-boxes increased the density of breeding and wintering birds in the studied pine plantations, indicating that a lack of natural holes are in fact a limiting factor for this populations. The earliest breeding start for this species was recorded in my study area, indicating that Portuguese coastal pines provide good breeding conditions earlier than in other areas of Europe and North Africa. This leads to an overlap between the end of the larvae stage of T. pityocampa and the beginning of the breeding season of P. major. Key-words: Thaumetopoea pityocampa, Parus major, Pinus pinaster, population dynamics, Portugal.

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Fractional calculus (FC) is widely used in most areas of science and engineering, being recognized its ability to yield a superior modeling and control in many dynamical systems. In this perspective, this article illustrates two applications of FC in the area of control systems. Firstly, is presented a methodology of tuning PID controllers that gives closed-loop systems robust to gain variations. After, a fractional-order PID controller is proposed for the control of an hexapod robot with three dof legs. In both cases, it is demonstrated the system's superior performance by using the FC concepts.

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This chapter appears in Innovations of Knowledge Management edited by Montano, D. Copyright 2004, IGI Global, www.igi-global.com. Posted by permission of the publisher.

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Nutrient recycling in the forest is linked to the production and decomposition of litter, which are essential processes for forest maintenance, especially in regions of nutritionally poor soils. Human interventions in forest such as selecttive logging may have strong impacts on these processes. The objectives of this study were to estimate litterfall production and evaluate the influence of environmental factors (basal area of vegetation, plant density, canopy cover, and soil physicochemical properties) and anthropogenic factors (post-management age and exploited basal area) on this production, in areas of intact and exploited forest in southern Amazonia, located in the northern parts of Mato Grosso state. This study was conducted at five locations and the average annual production of litterfall was 10.6 Mg ha-1 year-1, higher than the values for the Amazon rainforest. There were differences in litterfall productions between study locations. Effects of historical logging intensity on litterfall production were not significant. Effects of basal area of vegetation and tree density on litterfall production were observed, highlighting the importance of local vegetation characteristics in litterfall production. This study demonstrated areas of transition between the Amazonia-Cerrado tend to have a higher litterfall production than Cerrado and Amazonia regions, and this information is important for a better understanding of the dynamics of nutrient and carbon cycling in these transition regions.

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Aim  We test for the congruence between allele-based range boundaries (break zones) in silicicolous alpine plants and species-based break zones in the silicicolous flora of the European Alps. We also ask whether such break zones coincide with areas of large elevational variation.Location  The European Alps.Methods  On a regular grid laid across the entire Alps, we determined areas of allele- and species-based break zones using respective clustering algorithms, identifying discontinuities in cluster distributions (breaks), and quantifying integrated break densities (break zones). Discontinuities were identified based on the intra-specific genetic variation of 12 species and on the floristic distribution data from 239 species, respectively. Coincidence between the two types of break zones was tested using Spearman's correlation. Break zone densities were also regressed on topographical complexity to test for the effect of elevational variation.Results  We found that two main break zones in the distribution of alleles and species were significantly correlated. Furthermore, we show that these break zones are in topographically complex regions, characterized by massive elevational ranges owing to high mountains and deep glacial valleys. We detected a third break zone in the distribution of species in the eastern Alps, which is not correlated with topographic complexity, and which is also not evident from allelic distribution patterns. Species with the potential for long-distance dispersal tended to show larger distribution ranges than short-distance dispersers.Main conclusions  We suggest that the history of Pleistocene glaciations is the main driver of the congruence between allele-based and species-based distribution patterns, because occurrences of both species and alleles were subject to the same processes (such as extinction, migration and drift) that shaped the distributions of species and genetic lineages. Large elevational ranges have had a profound effect as a dispersal barrier for alleles during post-glacial immigration. Because plant species, unlike alleles, cannot spread via pollen but only via seed, and thus disperse less effectively, we conclude that species break zones are maintained over longer time spans and reflect more ancient patterns than allele break zones.Conny Thiel-Egenter and Nadir Alvarez contributed equally to this paper and are considered joint first authors.

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Healthy Ireland is a new national framework for action to improve the health and wellbeing of our country over the coming generation. Based on international evidence, it outlines a new commitment to public health with a considerable emphasis on prevention, while at the same time advocating for stronger health systems. It provides for new arrangements to ensure effective co-operation between the health sector and other areas of Government and public services, concerned with social protection, children, business, food safety, education, housing, transport and the environment. It also invites the private and voluntary sector to participate through well-supported and mutually beneficial partnerships. It sets out four central goals and outlines actions under 6 thematic areas, in which all people and all parts of society can participate to achieve these goals. Click here to download PDF 4.72MB

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BACKGROUND: Food allergy has reached an epidemic level in westernized countries and although central mechanisms have been described, the variability associated with genetic diversity underscores the still unresolved complexity of these disorders. OBJECTIVE: To develop models of food allergy and oral tolerance, both strictly induced by the intestinal route, and to compare antigen-specific responses. METHODS: BALB/c mice were mucosally sensitized to ovalbumin (OVA) in the presence of the mucosal adjuvant cholera toxin, or tolerized by intra-gastric administrations of OVA alone. Antibody titres and cytokines were determined by ELISA, and allergic status was determined through several physiologic parameters including decline in temperature, diarrhoea, mast cell degranulation and intestinal permeability. RESULTS: OVA-specific antibodies (IgE, IgGs and IgA in serum and feces) were produced in sensitized mice exclusively. Upon intra-gastric challenge with OVA, sensitized mice developed anaphylactic reactions associated with a decline of temperature, diarrhoea, degranulation of mast cells, which were only moderately recruited in the small intestine, and increased intestinal permeability. Cytokines produced by immune cells from sensitized mice included T-helper type 2 cytokines (IL-5, IL-13), but also IL-10, IFN-gamma and IL-17. In contrast, all markers of allergy were totally absent in tolerized animals, and yet the latter were protected from subsequent sensitization, demonstrating that oral tolerance took place efficiently. CONCLUSION: This work allows for the first time an appropriate comparison between sensitized and tolerized BALB/c mice towards OVA. It highlights important differences from other models of allergy, and thus questions some of the generally accepted notions of allergic reactions, such as the protective role of IFN-gamma, the importance of antigen-specific secretory IgA and the role of mucosal mast cells in intestinal anaphylaxis. In addition, it suggests that IL-17 might be an effector cytokine in food allergy. Finally, it demonstrates that intestinal permeability towards the allergen is increased during challenge.

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BACKGROUND: Food allergy has reached an epidemic level in westernized countries and although central mechanisms have been described, the variability associated with genetic diversity underscores the still unresolved complexity of these disorders. OBJECTIVE: To develop models of food allergy and oral tolerance, both strictly induced by the intestinal route, and to compare antigen-specific responses. METHODS: BALB/c mice were mucosally sensitized to ovalbumin (OVA) in the presence of the mucosal adjuvant cholera toxin, or tolerized by intra-gastric administrations of OVA alone. Antibody titres and cytokines were determined by ELISA, and allergic status was determined through several physiologic parameters including decline in temperature, diarrhoea, mast cell degranulation and intestinal permeability. RESULTS: OVA-specific antibodies (IgE, IgGs and IgA in serum and feces) were produced in sensitized mice exclusively. Upon intra-gastric challenge with OVA, sensitized mice developed anaphylactic reactions associated with a decline of temperature, diarrhoea, degranulation of mast cells, which were only moderately recruited in the small intestine, and increased intestinal permeability. Cytokines produced by immune cells from sensitized mice included T-helper type 2 cytokines (IL-5, IL-13), but also IL-10, IFN-gamma and IL-17. In contrast, all markers of allergy were totally absent in tolerized animals, and yet the latter were protected from subsequent sensitization, demonstrating that oral tolerance took place efficiently. CONCLUSION: This work allows for the first time an appropriate comparison between sensitized and tolerized BALB/c mice towards OVA. It highlights important differences from other models of allergy, and thus questions some of the generally accepted notions of allergic reactions, such as the protective role of IFN-gamma, the importance of antigen-specific secretory IgA and the role of mucosal mast cells in intestinal anaphylaxis. In addition, it suggests that IL-17 might be an effector cytokine in food allergy. Finally, it demonstrates that intestinal permeability towards the allergen is increased during challenge.

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AIM: The study aimed to analyse the currently available national and international guidelines for areas of consensus and contrasting recommendations in the treatment of diverticulitis and thereby to design questions for future research. METHOD: MEDLINE, EMBASE and PubMed were systematically searched for guidelines on diverticular disease and diverticulitis. Inclusion was confined to papers in English and those < 10 years old. The included topics were classified as consensus or controversy between guidelines, and the highest level of evidence was scored as sufficient (Oxford Centre of Evidence-Based Medicine Level of Evidence of 3a or higher) or insufficient. RESULTS: Six guidelines were included and all topics with recommendations were compared. Overall, in 13 topics consensus was reached and 10 topics were regarded as controversial. In five topics, consensus was reached without sufficient evidence and in three topics there was no evidence and no consensus. Clinical staging, the need for intraluminal imaging, dietary restriction, duration of antibiotic treatment, the protocol for abscess treatment, the need for elective surgery in subgroups of patients, the need for surgery after abscess treatment and the level of the proximal resection margin all lack consensus or evidence. CONCLUSION: Evidence on the diagnosis and treatment of diverticular disease and diverticulitis ranged from nonexistent to strong, regardless of consensus. The most relevant research questions were identified and proposed as topics for future research.

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To determine the morphological differences in the epithelium of the airways of recovered and susceptible pigs after Mycoplasma hyopneumoniae challenge, twenty-four 4-week-old M. hyopneumoniae-free pigs were intratracheally inoculated with 107ccu/ml of a pure low-passaged culture of the P5722-3 strain of M. hyopneumoniae challenge material. Eight pigs (group I) were challenged at the beginning of the experiment and rechallenged 3 months later. Group II pigs were also challenged at the beginning of the experiment and necropsied 3 months later. Group III pigs were challenged at the same time as the rechallenge of group I pigs. Eight nonchallenged pigs served as controls (group IV). Three days after the second challenge of group I and the first challenge of group III, and every 3 and 4 days thereafter, two pigs from each group were euthanatized by electrocution and necropsied. Samples of bronchi and lung tissue were examined using light and electron microscopy (SEM and TEM). Macroscopic lesions were observed in the lungs of all group III pigs (average = 4.74%) and were characterized by purple-red areas of discoloration and increased firmness affecting the cranioventral aspect of the lungs. Macroscopic lesions of pneumonia in groups I and II were minimal (less than 1%). There were no gross lesions of pneumonia in control (group IV) pigs. Microscopic lesions were characterized by hyperplasia of the peribronchial lymphoid tissue and mild neutrophilic infiltrates in alveoli. Electron microscopy showed patchy areas with loss of cilia and presence of leukocytes and mycoplasmas in bronchi of susceptible pigs (group III). The bronchial epithelium of rechallenged (group I), recovered (group II), and control (group IV) pigs was ultrastructurally similar indicating recovery of the former two groups. Although mycoplasmas were seen among cilia, a second challenge on pigs of group I did not produce another episode of the disease nor did it enhance morphological changes, suggesting that those pigs could become carriers of M. hyopneumoniae.

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Different patterns of granulomas have been observed in 6- to 8-week-old mice after ip inoculation with 5 x 10(6) yeast cells of Paracoccidioides brasiliensis. Transforming growth factor-ß (TGF-ß) is a cytokine that has been shown to participate in fibrosis and granuloma formation; its activities seem to be modulated by the small proteoglycan decorin. In the present study, TGF-ß and decorin expression in epiploon granulomas was assessed by immunohistochemistry in susceptible (B10.A) and resistant (A/J) mice after 15, 30, 120 and 150 days of P. brasiliensis ip infection. The epiploon was collected, fixed in Methacarn solution and embedded in paraffin, and 5-µm thick sections were used for immunohistochemical analysis employing the streptavidin-biotin-peroxidase technique. The former mouse strain developed fatal disease with many disseminated lesions increasing in size and number during the infection and the latter developed mild disease with the presence of encapsulated granulomas. In the epiploon, TGF-ß was present on macrophages, giant cells, lymphocytes and fibroblasts, and absent on neutrophils. It was also detected in areas of fibrosis and necrosis, as well as disperse in amorphous extracellular matrix, mostly in resistant mice. Decorin was present circumscribing macrophages and giant cells containing fungi, but absent on these cells. In both mouse strains, decorin was found at the periphery of the lesions, and markedly in milky spot granulomas. In resistant mice, positivity was found around fibrotic and necrotic areas of encapsulated and residual lesions containing lysed fungi. Decorin was found associated with thick fibers around encapsulated lesions. In susceptible mice, the size and number of lesions increased with the progression of the disease and were correlated with the weaker expression of decorin. We suggest an association of decorin with the fibrogenic process observed in paracoccidioidal granulomas.

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This qualitative study examined resilience factors of eight university and college students with learning disabilities as revealed through retrospective interviews. This study has added to the existing literature surrounding resilience especially as it relates to individuals with learning disabilities. This study may provide additional insight into the emotional impacts of repeated and chronic risks on students with learning disabilities. The major themes that emerged using the interpretive phenomenological analysis method (Smith & Osborn, 2003) were organized under these four major headings: Challenges and Obstacles, Surviving Challenges, Supportive Conditions, and A Journey of Discovery and Hope. An adaptation of the listening guide analytical method (Gilligan, Spencer, Weinberg, & Bertsch, 2003) was also utilized and offered a more personal depiction of the participants and an exploration of the unique contributions their stories made to this study. Specifically, a theme of feeling trapped/wanting to escape emerged as a reaction to adversity faced during elementary school years. Furthennore, this study has demonstrated that for several of the participants, the benefits of positive outlets extended beyond nurturing areas of strength and self-esteem to also include the provision of a short respite from their challenges and enhanced feelings of overall well-being. Additionally, this study may add to the existing literature surrounding character traits evident in resilient students, specifically highlighting the significance of optimism and selfacceptance.

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Objective: There were two aims to this study: first to examine whether emotional abuse and neglect are significant predictors of psychological and somatic symptoms, and lifetime trauma exposure in women presenting to a primary care practice, and second to examine the strength of these relationships after controlling for the effects of other types of childhood abuse and trauma. Method: Two-hundred and five women completed the Childhood Trauma Questionnaire (Bernstein et al., 1994), Trauma History Questionnaire (Green, 1996), the Symptom Checklist-revised (Derogatis, 1997), and the Revised Civilian Mississippi Scale for posttraumatic stress disorder (Norris & Perilla, 1996) when presenting to their primary care physician for a visit. Hierarchical multiple regression analyses were conducted to examine unique contributions of emotional abuse and neglect variables on symptom measures while controlling for childhood sexual and physical abuse and lifetime trauma exposure. Results: A history of emotional abuse and neglect was associated with increased anxiety, depression, posttraumatic stress and physical symptoms, as well as lifetime trauma exposure. Physical and sexual abuse and lifetime trauma were also significant predictors of physical and psychological symptoms. Hierarchical multiple regressions demonstrated that emotional abuse and neglect predicted symptomatology in these women even when controlling for other types of abuse and lifetime trauma exposure. Conclusions: Long-standing behavioral consequences may arise as a result of childhood emotional abuse and neglect, specifically, poorer emotional and physical functioning, and vulnerability to further trauma exposure. (C) 2003 Elsevier Ltd. All rights reserved.

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This article is a position paper which examines the political and public discourse around the areas of diversity and social cohesion, and history teaching. It examines the nature of these discourses and shows how they are in tension. Although discourse around diversity often has a focus on mutual understanding and finding areas of commonality, the discourse around history often focuses on the need to provide a sense of identity through a national story. By focusing on a discussion about the purposes of history, rather than merely on debates about content, it is suggested that these discourses can be brought more closely into line and produce a more productive line of policy debate.