917 resultados para Generalist and specialists


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Mode of access: Internet.

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The response of generalist egg parasitoids to alternative natural hosts that are present simultaneously is not well known. We investigated the behavior of Trichogramma pretiosum Riley (Hymenoptera: Trichogrammatidae) in relation to two field hosts Helicoverpa armigera Hubner and Spodoptera litura Fabricius, in choice and no choice tests. We quantified the effects of natal host species and post-emergence adult age on the oviposition preference of the parasitoids. H. armigera eggs were consistently preferred over S. litura eggs, regardless of the natal host and adult age. When only S. litura eggs were available as hosts, they were parasitized at statistically similar rates to H. armigera eggs (average of 17 +/- 2.7 vs. 13 +/- 3.0, H. armigera to S. litura). The adult lifespan and lifetime fecundity of T. pretiosum were variable but were affected by natal host species and/or host species to which they were exposed. Mean lifespan and fecundity of parasitoids that had developed in H. armigera eggs and were exposed to H. armigera eggs for oviposition were 13.9 +/- 1.8 days and 98.7 +/- 11.0 adult offspring. By contrast, those that developed in S. litura eggs and were exposed to S. litura eggs for oviposition lived for 7 +/- 0.9 days and produced 53.8 +/- 8.0 adult offspring. The ovigeny index (OI) was significantly lower in the parasitoids exposed to H. armigera eggs than in those exposed to S. litura eggs, regardless of the natal host, indicating that H. armigera eggs sustain the adult parasitoids better than S. litura eggs. These results are used to predict parasitoid behavior in the field when both hosts are available. (c) 2006 Elsevier Inc. All rights reserved.

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Following an introductory chapter, I examine (i) typologies which have differentiated the literature on organisational culture and symbolism (Chapter 2), (ii) the contribution of organisation theory to organisation culture (Chapter 3), and (iii) recent literature on organisational culture and symbolism (Chapter 4). Within these chapters, I adopt Habermas' (1972) notion of knowledge-constitutive interests, assessing the contrubutions to understanding organisational culture made by literature guided by technical, practical and emancipatory cognitive interests. In doing so, I suggest that more critical studies on organisational culture and symbolism have been comparatively neglected. Lamenting this neglect, I suggest that Giddens' theory of structuration can be employed to advance the development of a critical, emancipatory conceptualisation of organisational culture. In particular, I argue that this Giddensian analysis, by penetrating the existential, poltical and material processes of cultural reproduction (Chapter 5), is able to disclose some of the more contradictory features of organisation culture. The remainder of the thesis comprises of a critical ethnography of the work cultures of public relations and personnel specialists located in a state bureaucracy. I begin the ethnography with a dicussion of my research methods (Chapter 6) and an overview of the departments studied (Chapter 7): I then examine (i) the work cultures of the specialists (Chapter 8), (ii) the specialists' management of the relationships with the hosts bureaucracy (Chapter 9); and, (iii) opportunities the specialists had for developing an emancipatory praxis (Chapter 10). Finally, in a concluding section, I offer some critical reflections on the contributions of the thesis and suggest areas for future research.

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From educational, communications, psychological, and technical points of view, the renovation of pedagogy in media education is based upon the promotion of "educational technology." The promotion of educational technology relies upon the appropriate availability and knowledge of different educational media made available by the trained media personnel.^ In the past three decades most of the junior colleges in Taiwan set up educational media centers to help students learn through the use of media which enables them to obtain optimum benefits in a short time. What are the roles the media personnel play in the media center? What responsibilities have they to bear in the center? What differences are there when a trained and untrained media personnel are presented in junior colleges media center in Taiwan? What do the trained and untrained media personnel feel toward the importance of each media service in the area of media center's administration, media production, specialized media duties, and the training of staff in media use? These are the questions addressed in this study.^ Through the study of the related literature and a survey conducted in the junior colleges in Taiwan, recommendations are offered to provide improvement of the services and training of media specialists in Taiwan that are appropriate for a changing work and environment. These recommendations are for media specialists to be formally trained to effectively serve the changing needs of school library media so as to make optimal use of media in the junior colleges. ^

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For the first time in more than fifty years, the domestic and external conflicts in Latin America and the Caribbean (LAC) are not primarily ideological in nature. Democracy continues to thrive and its promise still inspires hope. In contrast, the illegal production, consumption, and trading of drugs – and its links to criminal gangs and organizations – represent major challenges to the region, undermining several States’ already weak capacity to govern. While LAC macroeconomic stability has remained resilient, illegal economies fill the region, often offering what some States have not historically been able to provide – elements of human security, opportunities for social mobility, and basic survival. Areas controlled by drug trafficking organizations (DTOs) are now found in Central America, Mexico, and the favelas of Rio de Janeiro and São Paulo, reflecting their competition for land routes and production areas. Cartels such as La Familia, Los Zetas, and Primeiro Comando da Capital (PCC-Brazil), among others, operate like trade and financial enterprises that manage millions of dollars and resources, demonstrating significant business skills in adapting to changing circumstances. They are also merciless in their application of violence to preserve their lucrative enterprises. The El Salvador-Guatemala-Honduras triangle in Central America is now the most violent region in the world, surpassing regions in Africa that have been torn by civil strife for years. In Brazil’s favelas and Guatemala’s Petén region, the military is leaving the barracks again; not to rule, however, but to supplement and even replace the law enforcement capacity of weak and discredited police forces. This will challenge the military to apply lessons learned during the course of their experience in government, or from the civil wars that plagued the region for nearly 50 years during the Cold War. Will they be able to conduct themselves according to the professional ethics that have been inculcated over the past 20 years without incurring violations of human rights? Belief in their potential to do good is high according to many polls as the Armed Forces still enjoy a favorable perception in most societies, despite frequent involvement in corruption. Calling them to fight DTOs, however, may bring them too close to the illegal activities they are being asked to resist, or even rekindle the view that only a “strong hand” can resolve national troubles. The challenge of governance is occurring as contrasts within the region are becoming sharper. There is an increasing gap between nations positioned to surpass their “developing nation” status and those that are practically imploding as the judicial, political and enforcement institutions fall further into the quagmire of illicit activities. Several South American nations are advancing their political and economic development. Brazil in particular has realized macro-economic stability, made impressive gains in poverty reduction, and is on track to potentially become a significant oil producer. It is also an increasingly influential power, much closer to the heralded “emerging power” category that it aspired to for most of the 20th century. In contrast, several Central American States have become so structurally deficient, and have garnered such limited legitimacy, that their countries have devolved into patches of State controlled and non-State-controlled territory, becoming increasingly vulnerable to DTO entrenchment. In the Caribbean, the drug and human trafficking business also thrives. Small and larger countries are experiencing the growing impact of illicit economies and accompanying crime and violence. Among these, Guyana and Suriname face greater uncertainty, as they juggle both their internal affairs and their relations with Brazil and Venezuela. Cuba also faces new challenges as it continues focusing on internal rather than external affairs and attempts to ensure a stable leadership succession while simultaneously trying to reform its economy. Loosening the regime’s tight grip on the economy while continuing to curtail citizen’s civil rights will test the leadership’s ability to manage change and prevent a potential socio-economic crisis from turning into an existential threat. Cuba’s past ideological zest is now in the hands of Venezuela’s President Hugo Chavez, who continues his attempts to bring the region together under Venezuelan leadership ideologically based on a “Bolivarian” anti-U.S. banner, without much success. The environment and natural disasters will merit more attention in the coming years. Natural events will produce increasing scales of destruction as the States in the region fail to maintain and expand existing infrastructure to withstand such calamities and respond to their effects. Prospects for earthquakes, tsunamis, and hurricanes are high, particularly in the Caribbean. In addition, there are growing rates of deforestation in nearly every country, along with a potential increase in cross-sector competition for resources. The losers might be small farmers, due to their inability to produce quantities commensurate to larger conglomerates. Regulations that could mitigate these types of situations are lacking or openly violated with near impunity. Indigenous and other vulnerable populations, including African descendants, in several Andean countries, are particularly affected by the increasing extraction of natural resources taking place amongst their terrain. This has led to protests against extraction activities that negatively affect their livelihoods, and in the process, these historically underprivileged groups have transitioned from agenda-based organization to one that is bringing its claims and grievances to the national political agenda, becoming more politically engaged. Symptomatic of these social issues is the region’s chronically poor quality of education that has consistently failed to reduce inequality and prepare new generations for jobs in the competitive global economy, particularly the more vulnerable populations. Simultaneously, the educational deficit is also exacerbated by the erosion of access to information and freedom of the press. The international panorama is also in flux. New security entities are challenging the old establishment. The Union of South American Nations, The South American Defense Council, the socialist Bolivarian Alliance, and other entities seem to be defying the Organization of American States and its own defense mechanisms, and excluding the U.S. And the U.S.’s attention to areas in conflict, namely Iraq, Afghanistan, and Pakistan – rather than to the more stable Latin America and Caribbean – has left ample room for other actors to elbow in. China is now the top trading partner for Brazil. Russian and Iran are also finding new partnerships in the region, yet their links appear more politically inclined than those of China. Finally, the aforementioned increasing commercial ties by LAC States with China have accelerated a return to the preponderance of commodities as sources of income for their economies. The increased extraction of raw material for export will produce greater concern over the environmental impact that is created by the exploitation of natural resources. These expanded trade opportunities may prove counterproductive economically for countries in the region, particularly for Brazil and Chile, two countries whose economic policies have long sought diversification from dependence on commodities to the development of service and technology based industries.

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Efforts to ‘modernize’ the clinical workforce of the English National Health Service have sought to reconfigure the responsibilities of professional groups in pursuit of more effective, joined-up service provision. Such efforts have met resistance from professions eager to protect their jurisdictions, deploying legitimacy claims familiar from the insights of the sociology of professions. Yet to date few studies of professional boundaries have grounded these insights in the specific context of policy challenges to the inter- and intra-professional division of labour, in relation the medical profession and other health-related occupations. In this paper we address this gap by considering the experience of newly instituted general practitioners (family physicians) with a special interest (GPSIs) in genetics, introduced to improve genetics knowledge and practice in primary care. Using qualitative data from four comparative case studies, we discuss how an established intra-professional division of labour within medicine—between clinical geneticists and GPs—was opened, negotiated and reclosed in these sites. We discuss the contrasting attitudes towards the nature of genetics knowledge and its application of GPSIs and geneticists, and how these were used to advance conflicting visions of what the nascent GPSI role should involve. In particular, we show how the claims to knowledge of geneticists and GPSIs interacted with wider policy pressures to produce a rather more conservative redistribution of power and responsibility across the intra-professional boundary than the rhetoric of modernization might suggest.

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Harmony is one of the main objectives in surgical and orthodontic treatment and this harmony must be present in the smile, as well as in the face. The aim of the present study was to assess the perceptions of professionals and laypersons in relation to the harmony of the smile of patients with or without vertical maxillary alterations. Sixty observers (oral and maxillofacial surgeons, orthodontists and laypersons) reported the degree of harmony of six smiles using an objective questionnaire and the participants indicated if there was a need for corrective surgery or not. The classification of observers was recorded on a Likert scale from 1 to 5. Mixed regression was used to determine differences between the three groups. Statistically significant differences were found only for the harmony of the smile between the oral and maxillofacial surgeons and laypersons, with laypersons being more critical when assessing the smile. There was no statistical difference between the other groups for the harmony of the smile or the indication of corrective surgery. The patterns of greater or lesser harmony determined by observers during the smile were similar to those found in the literature as the ideal standard in relation to vertical maxillary positioning. Laypersons had a tendency to be more critical in relation to facial harmony than surgeons, although no statistical differences were found in the other groups in relation to the harmony of the smile or indication for the corrective surgery. In addition, the patterns of greater or lesser harmony of the smile determined by the participants were similar to those found in the literature as the ideal standard in relation to vertical maxillary positioning. Overall, the present study demonstrates that adequate interaction between surgeons, orthodontists and laypersons is essential in order to achieve facial harmony with orthodontic and/or surgical treatment. Opinion of specialists and laypersons about the smile in relation to the vertical positioning of the maxilla.

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Universidade Estadual de Campinas . Faculdade de Educação Física

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Secondary forests and exotic tree plantations are expanding across tropical landscapes. However, our current understanding of the value of these human-dominated forest landscapes for invertebrate biodiversity conservation is still very poor. In this paper, we use the leaf-litter ant fauna to assess invertebrate diversity in one commercially managed Eucalyptus plantation (four years old), two abandoned plantations of different regeneration ages (16 and 31 years), and one neighboring secondary Atlantic Forest in Southeastern Brazil. There was a clear gradient in species richness from the secondary forest to the managed Eucalyptus plantation; richness and diversity peaked in secondary forest and in the older regenerating Eucalyptus plantation. Significantly more species were recorded in secondary forest samples than in Eucalyptus plantations, but Eucalyptus plantations had a similar level of richness. Furthermore, a non-metric multidimensional scaling analysis revealed clear differences in species composition between the younger managed Eucalyptus plantation (understory absent) and habitats with sub-developed or developed understory. Eucalyptus plantations were characterized by an assemblage of widespread, generalist species very different from those known to occur in core forest habitats of southeastern Brazil. Our results indicate that while older regenerating Eucalyptus plantations can provide habitat to facilitate the persistence of generalist ant species, it is unlikely to conserve most of the primary forest species, such as specialized predators, Dacetini predators, and nomadic species.

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Background: There is growing demand for the adoption of qualification systems for health care practices. This study is aimed at describing the development and validation of indicators for evaluation of biologic occupational risk control programs. Methods: The study involved 3 stages: (1) setting up a research team, (2) development of indicators, and (3) validation of the indicators by a team of specialists recruited to validate each attribute of the developed indicators. The content validation method was used for the validation, and a psychometric scale was developed for the specialists` assessment. A consensus technique was used, and every attribute that obtained a Content Validity Index of at least 0.75 was approved. Results: Eight indicators were developed for the evaluation of the biologic occupational risk prevention program, with emphasis on accidents caused by sharp instruments and occupational tuberculosis prevention. The indicators included evaluation of the structure, process, and results at the prevention and biologic risk control levels. The majority of indicators achieved a favorable consensus regarding all validated attributes. Conclusion: The developed indicators were considered validated, and the method used for construction and validation proved to be effective.

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Generalist pathogens frequently exist as a complex of genetically differentiated strains, which can differ in virulence and transmissibility. A description of the extent to which strain variability mediates host species competence is needed to understand disease dynamics for systems with both host and pathogen strain diversity. This study tested the hypothesis that strain-specific variation of a generalist vector-borne plant pathogen, Xylella fastidiosa, affects disease severity in alfalfa (Medicago sativa) and competence of this crop as a reservoir host. Alfalfa seedlings were inoculated with one of 23 X. fastidiosa isolates collected from different hosts, eight identified as belonging to an almond strain, and the remainder from a grape strain. Pathogen population, symptom severity and infection incidence were compared over five successive harvests. Infected plant size, measured mainly by plant height, internode length and above ground biomass, was reduced up to 50% compared to buffer-inoculated controls, and more severe symptoms were observed at later harvests and for higher pathogen populations. Grape isolates had higher bacterial populations within alfalfa than almond isolates. In addition, infection with grape isolates resulted in more severe alfalfa stunting than that caused by almond isolates. Moreover, there was a strong positive relationship between isolate multiplication rate and both symptom severity and infection persistence (i.e. maintenance of chronic infection within host). Isolates with low initial populations had low incidence at the final harvest, with one isolate dying out altogether. The results showed that X. fastidiosa-genetic diversity contributed to variation in alfalfa disease severity. The results also suggest that pathogen strain may mediate host competence via differences in bacterial population density and persistence.