945 resultados para Life Histories
Resumo:
It is generally acknowledged that population-level assessments provide,I better measure of response to toxicants than assessments of individual-level effects. population-level assessments generally require the use of models to integrate potentially complex data about the effects of toxicants on life-history traits, and to provide a relevant measure of ecological impact. Building on excellent earlier reviews we here briefly outline the modelling options in population-level risk assessment. Modelling is used to calculate population endpoints from available data, which is often about Individual life histories, the ways that individuals interact with each other, the environment and other species, and the ways individuals are affected by pesticides. As population endpoints, we recommend the use of population abundance, population growth rate, and the chance of population persistence. We recommend two types of model: simple life-history models distinguishing two life-history stages, juveniles and adults; and spatially-explicit individual-based landscape models. Life-history models are very quick to set up and run, and they provide a great deal or insight. At the other extreme, individual-based landscape models provide the greatest verisimilitude, albeit at the cost of greatly increased complexity. We conclude with a discussion of the cations of the severe problems of parameterising models.
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Over many millions of years of independent evolution, placental, marsupial and monotreme mammals have diverged conspicuously in physiology, life history and reproductive ecology. The differences in life histories are particularly striking. Compared with placentals, marsupials exhibit shorter pregnancy, smaller size of offspring at birth and longer period of lactation in the pouch. Monotremes also exhibit short pregnancy, but incubate embryos in eggs, followed by a long period of post-hatching lactation. Using a large sample of mammalian species, we show that, remarkably, despite their very different life histories, the scaling of production rates is statistically indistinguishable across mammalian lineages. Apparently all mammals are subject to the same fundamental metabolic constraints on productivity, because they share similar body designs, vascular systems and costs of producing new tissue.
Resumo:
Pontryagin's maximum principle from optimal control theory is used to find the optimal allocation of energy between growth and reproduction when lifespan may be finite and the trade-off between growth and reproduction is linear. Analyses of the optimal allocation problem to date have generally yielded bang-bang solutions, i.e. determinate growth: life-histories in which growth is followed by reproduction, with no intermediate phase of simultaneous reproduction and growth. Here we show that an intermediate strategy (indeterminate growth) can be selected for if the rates of production and mortality either both increase or both decrease with increasing body size, this arises as a singular solution to the problem. Our conclusion is that indeterminate growth is optimal in more cases than was previously realized. The relevance of our results to natural situations is discussed.
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The fungal family Clavicipitaceae includes plant symbionts and parasites that produce several psychoactive and bioprotective alkaloids. The family includes grass symbionts in the epichloae clade (Epichloë and Neotyphodium species), which are extraordinarily diverse both in their host interactions and in their alkaloid profiles. Epichloae produce alkaloids of four distinct classes, all of which deter insects, and some—including the infamous ergot alkaloids—have potent effects on mammals. The exceptional chemotypic diversity of the epichloae may relate to their broad range of host interactions, whereby some are pathogenic and contagious, others are mutualistic and vertically transmitted (seed-borne), and still others vary in pathogenic or mutualistic behavior. We profiled the alkaloids and sequenced the genomes of 10 epichloae, three ergot fungi (Claviceps species), a morning-glory symbiont (Periglandula ipomoeae), and a bamboo pathogen (Aciculosporium take), and compared the gene clusters for four classes of alkaloids. Results indicated a strong tendency for alkaloid loci to have conserved cores that specify the skeleton structures and peripheral genes that determine chemical variations that are known to affect their pharmacological specificities. Generally, gene locations in cluster peripheries positioned them near to transposon-derived, AT-rich repeat blocks, which were probably involved in gene losses, duplications, and neofunctionalizations. The alkaloid loci in the epichloae had unusual structures riddled with large, complex, and dynamic repeat blocks. This feature was not reflective of overall differences in repeat contents in the genomes, nor was it characteristic of most other specialized metabolism loci. The organization and dynamics of alkaloid loci and abundant repeat blocks in the epichloae suggested that these fungi are under selection for alkaloid diversification. We suggest that such selection is related to the variable life histories of the epichloae, their protective roles as symbionts, and their associations with the highly speciose and ecologically diverse cool-season grasses.
Resumo:
Individual-based models (IBMs) can simulate the actions of individual animals as they interact with one another and the landscape in which they live. When used in spatially-explicit landscapes IBMs can show how populations change over time in response to management actions. For instance, IBMs are being used to design strategies of conservation and of the exploitation of fisheries, and for assessing the effects on populations of major construction projects and of novel agricultural chemicals. In such real world contexts, it becomes especially important to build IBMs in a principled fashion, and to approach calibration and evaluation systematically. We argue that insights from physiological and behavioural ecology offer a recipe for building realistic models, and that Approximate Bayesian Computation (ABC) is a promising technique for the calibration and evaluation of IBMs. IBMs are constructed primarily from knowledge about individuals. In ecological applications the relevant knowledge is found in physiological and behavioural ecology, and we approach these from an evolutionary perspective by taking into account how physiological and behavioural processes contribute to life histories, and how those life histories evolve. Evolutionary life history theory shows that, other things being equal, organisms should grow to sexual maturity as fast as possible, and then reproduce as fast as possible, while minimising per capita death rate. Physiological and behavioural ecology are largely built on these principles together with the laws of conservation of matter and energy. To complete construction of an IBM information is also needed on the effects of competitors, conspecifics and food scarcity; the maximum rates of ingestion, growth and reproduction, and life-history parameters. Using this knowledge about physiological and behavioural processes provides a principled way to build IBMs, but model parameters vary between species and are often difficult to measure. A common solution is to manually compare model outputs with observations from real landscapes and so to obtain parameters which produce acceptable fits of model to data. However, this procedure can be convoluted and lead to over-calibrated and thus inflexible models. Many formal statistical techniques are unsuitable for use with IBMs, but we argue that ABC offers a potential way forward. It can be used to calibrate and compare complex stochastic models and to assess the uncertainty in their predictions. We describe methods used to implement ABC in an accessible way and illustrate them with examples and discussion of recent studies. Although much progress has been made, theoretical issues remain, and some of these are outlined and discussed.
Resumo:
Most amphibian species have biphasic life histories and undergo an ontogenetic shift from aquatic to terrestrial habitats. In deforested landscapes, streams and forest fragments are frequently disjunct, jeopardizing the life cycle of forest-associated amphibians with aquatic larvae. We tested the impact of habitat split-defined as human-induced disconnection between habitats used by different life-history stages of a species-on four forest-associated amphibian species in a severely fragmented landscape of the Brazilian Atlantic Forest. We surveyed amphibians in forest fragments with and without streams (referred to as wet and dry fragments, respectively), including the adjacent grass-field matrix. Our comparison of capture rates in dry fragments and nearby streams in the matrix allowed us to evaluate the number of individuals that engaged in high-risk migrations through nonforested habitats. Adult amphibians moved from dry fragments to matrix streams at the beginning of the rainy season, reproduced, and returned at the end of the breeding period. Juveniles of the year moved to dry fragments along with adults. These risky reproductive migrations through nonforested habitats that expose individuals to dehydration, predation, and other hazards may cause population declines in dry fragments. Indeed, capture rates were significantly lower in dry fragments compared with wet fragments. Declining amphibians would strongly benefit from investments in the conservation and restoration of riparian vegetation and corridors linking breeding and nonbreeding areas.
Resumo:
O objetivo desta pesquisa foi investigar a vida cotidiana de mulheres rotuladas como deficientes mentais, através de seus relatos biográficos pessoais. As entrevistadas descreveram sua rotina em casa e na instituição, falaram sobre suas famílias, relacionamentos, dificuldades em integração social, e sobre seus problemas físicos e de aprendizagem. Ficou clara no discurso deste grupo a dicotomia entre o mundo “de dentro", compreendendo os espaços protegidos da casa e da instituição, e o mundo ameaçador e violento “de fora", representado pela rua. Seus relacionamentos sociais restringem-se aos personagens do mundo “de dentro": a família, os profissionais, e os colegas da instituição, e muitas entrevistadas disseram se· sentir discriminadas pelas pessoas “de fora". Embora várias mulheres tenham exprimido o desejo de ser independentes (trabalhar fora, sair sozinhas, etc), na prática mantém urna relação de extrema dependência familiar. A pesar de dois terços das entrevistadas terem mais de 20 anos, elas não parecem ter nenhuma perspectiva concreta de morar sozinhas, casar, ou vir a formar sua própria família. Um dos pressupostos deste estudo era de que o estigma da deficiência mental, seria o terna central nas histórias de vida. Entretanto, mais da metade dos sujeitos não abordou esta questão, e muito poucas se autodenominaram deficientes. Foi postulado que os efeitos do estigma talvez sejam minimizados neste grupo devido à superproteção familiar e institucional por um lado, e a evitação do mundo "de fora" (onde esta condição seria denunciada mais abertamente) por outro. Assim sendo, em sua prática diária, a maioria dessas mulheres têm poucas oportunidades de se confrontar com a situação de marginalização. Deficiência mental foi analisada como um fenômeno socialmente construído, e acredita-se que estas pessoas funcionem em um nível mais dependente do que sua condição orgânica exigiria, por terem sido reforçadas por representar o papel social de deficientes. Apesar das características comuns, cada história de vida provou ser original e única, mostrando o erro em se considerar as pessoas portadoras de deficiência mental como um grupo homogêneo e bem definido. Além disso, a não ser pela dependência familiar, falta de participação autônoma e integrada na comunidade, e relacionamento amoroso e sexual restrito, a ideia dessas mulheres não é qualitativamente diferente do resto da população.
Resumo:
Este trabalho teve por objetivo identificar as vivências femininas no decorrer de seu primeiro parto normal. Pressupondo-se uma abordagem baseada nos ensinamentos fenomenológicos, foi planejada uma pesquisa exploratória de campo em que 30 puérperas de parto normal, poucas horas após terem dado à luz. As entrevistas seguiram o modelo metodológico da técnica de histórias de vida e, através destas, as puérperas contribuíram com um relato acerca de seu parto. Os relatos serviram para nos dar informes a respeito de quatro aspectos básicos acerca da parturiente no processar do seu parto normal: a) vivências físicas; b) vivências emocionais; c) significado da experiência e d) percepção da conduta médica. A experiência de gerar um filho para praticamente todas as mulheres entrevistadas mostrou-se altamente importante e plena de gratificações. Apenas um pequeno número de mulheres apresentou considerações negativas à chegada da criança.
Resumo:
This work is an analysis about the teacher's formation starting from certain aspects of its culture. It is supposed that the teacher is constituted in an individual that acts starting from singular aspects, in an individual point of view, but at the same time it interacts with other individuals in an environment strongly marked by the culture. Those two dimensions are representatives of the socio-cultural characteristics and they can be seen in the perspective of the individual and collective identity. Based on those presuppositions we chose, as reference, four environment of formation: the family, the school, the work and the Movement of the Rural Workers Without-Soil/MST (MST: The without-soil-ones in Portuguese) observing as the teachers refers to those environment highlighting, mostly, the formative aspects stood out. The individuals researched are teachers involved in the education of settled communities, who are students of the Earth Pedagogy course of the Universidade Federal do Rio Grande do Norte/UFFRN. For our analyses, we used narrative texts, written by the teachers, as conclusion of the discipline History of the Brazilian Education in which they tell their life histories. The speeches show as the environments of reference influence in their world conceptions, attitudes and values that not just mix in an individual dimension, but also collective. The research make us reflect about the possibility to think on the educational action starting from that understanding of wide formation considering the present elements in the courses of teacher's life
Resumo:
We make many journeys during our lifetime. In each of them we accumulate experiences that result in an amount of knowledge that constitutes our history. The dissertation presents one of these journeys: that one I took along with students of Pedagogia da Terra project from Universidade do Estado do Rio Grande do Norte UERN to think about the knowledge within their memories in their way from countryside to city seeking for education. I used as main references to this task the ideas of Edgar Morin about Method as Strategy, implication of the subject in knowledge, pertinent knowledge, and knowledge reconnection. And from Paulo Freire I used the concepts of cultural identity assumption and dialog. I built as resource of method the metaphor of the suitcase, called by me the trunk of memory treasures . The use of this cognitive operator makes possible for those students bring their memories to the surface and share them collectively, by the process I name as auto-social- biographical narratives. The explicitness of the memories they choose to reveal by means of these narratives permitted me to understand the metamorphosis of these knowledge since their childhood to nowadays. In order to present an archeology of knowledge within these life histories I chose a narrative writing style concerned with simplicity and lightness, where I use the description of facts and discussions occurred during this journey. My main arguments in systematizing this experience are: scientific production can and should be grounded on knowledge diversity and on a more sensible approach to phenomena; education and pedagogy need to take as starting point and fuel for their practices the singularities of the subjects, their life history, educational background and knowledge resulting from both. Teacher s formation programs which students have mixed, rural and urban, background should value cognitive experiences built in the interaction with that knowledge closer of a sensible logic, deeper grounded in land and nature. Doing so, education can contribute to join diverse knowledge against monocutural forms of thinking and educational practices
Resumo:
This thesis describes and analyzes the trajectory of education of an educator-teacher group to become tutor of memorials (final work of the course Normal Superior in Instituto de Educação superior President Kennedy IFESP-Natal-RN). The writing of memorials (self-biographical writing) propitiates to the pupil that writes a reflection on his/her student and professional life, and to whom guides an evolution in his/her professional education. From the methodological point of view, we adopt an etnomethodological perspective of qualitative approach which describes the reality of real citizens inserted in a real situation of education. It is constituted of participants of the research of 32 educator-teachers, deriving of three different areas of academic formation. The instruments of data collection consist of eight life histories, 32 contextualization applications of the participants of the research, interviews with two consultants of the project, as well as some documents. The results of the analyses put in evidence that the education of the educator-teacher goes for two parallel ways: the first deals with the experiences, interactions and elements of daily practice; the second with the academy experiences where the educator-teacher searches the post-graduation courses. The integration of these two ways defines the educator-teacher identity with foundation in knowings that constitute in the exercise of guidance of memorials. The teachers knowings are considered insufficient by the majority and others knowings are mobilized to the knowing to be educator-teacher, memorial tutor. The thesis concludes that the trajectory of the educator-teacher constitutes an educator experience, in the direction of that implies an articulation among the learnings, abilities and knowings, to support the pupil in self-discovery, and that these multiple experiences favor the education of these teachers
Resumo:
Reconstruct, from listening, the life histories of a chronic renal patient, submitted to hemodialysis, is the objective of this investigation. How methodological procedure,we worked with oral history of life, ,according Meihy, within a qualitative approach. For this, we had the approval of the Ethics Committee in Research of Hospital Universitário Onofre Lopes (HUOL), under protocol no 591/2011. As instrument to approach the patient, we did interviews with open questions, conducted in the patient's house. There were five meetings, in which we hear his story, experiences and ways of coping during their course of illness and treatment. The analysis was based on the collaborator's narratives, anchored in studies dealing with oral history, of human subjectivity, highlighting the resilience, as indicated Cyrulnik. Her story leads us to conclude that despite the adversities of life and suffering, there is in humans, the strength to navigate the streams and be happy. This is the lesson that leaves us the collaborator this study.
Resumo:
The studies paths in the maze: life story of individuals with oncological diseases into use of blood transfusion in Natal has the hemotherapy as a primordial procedure to review the relationship between users of oncological health and the due ramifications. The hemotherapy looks for supply the organic needs through blood transfusion, which acquires vital function to the ones that have cancer, because it might reestablish the functionality of the organism throughout the raising of blood components. The impact over the transfusion affects emotionally and physically the users life. Aiming to reflect on these impacts, this study tried, through narratives of lives, rescue their experience since their knowledge of the disease until the time of blood transfusion using. It s about an exploratory-descriptive study, where the qualitative approach uses the theoretical-methodological reference of the oral life history to analyze a colony consisting of five users of health diagnosed with cancer, with achievement of at least three blood transfusions, the clinic Núcleo de Hematologia e Hemoterapia - UFRN, in Natal-RN. The network, in turn, was composed by employees of both sexes, regardless of age, who voluntarily agreed to participate in the study. The data collection, with approval of the Ethics Committee in Research, Liga Norte Riograndense Contra o Cancer, on the number 001/001/2012, occurred through semi-structured interviews, recorded individually in the home context that was previously chosen by employees. The methodological procedure occurred with the transcription of the interviews and their transcreations, and analysis of reports by thematic content analysis. At the reading orientation and interpretation of the employees stories, were discussed three categories of analysis: the impact on psychological REVIEW; impact on socialization and group membership, the environment and the impact of blood transfusion on treatment. Based on the narrative of the life histories of employees, we conclude that the experiences and feelings, hope and sorrow, pain and faith, even when facing a disease like cancer, bring lots of teaching and learning to health professional that deposits humanization health and reinstate hemotherapy forms of clinical critical
Resumo:
Several epidemics marked the lives of individuals and communities in all historical periods, and a prime example is leprosy, infectious disease marked by stigma, prejudice and social exclusion. In the past, the compulsory isolation of patients with leprosy caused serious social and psychological problems, resulting in the separation and the partial or total disruption of the family relationship. Children deprived of this living, removed often inhumanely, were kept and bred in preventoriums / educational establishments. This study aimed to: rescue the oral history of life of the children of leprosy patients that were built in preventorium Osvaldo Cruz, Natal, Rio Grande do Norte; develop a contextual analysis about these children; know the life trajectory of children of leprosy patients institutionalized in preventoriums / educational establishments; produce a documentary on the history of life of children of parents separated by leprosy; forming MORHAN of Rio Grande do Norte state; and implement the I Meeting of MORHAN of Rio Grande do Norte state. This is an exploratory and descriptive study, with a qualitative approach, approved by the ERC No. 024/024/2012 Liga Norteriograndense Contra o Câncer. We used the contributions of the method and technique of oral history of life as methodological reference. We interviewed 10 individuals egress from preventorium Osvaldo Cruz in Natal/RN, sons of former patients proven to be residents in the city, of both sexes, older than 18, with cognitive, intellectual and emotional conditions preserved. The analysis of the histories obtained from collaborators was performed in the light of Thematic Content Analysis. The results and discussions are presented through two articles which meet the proposed objectives. The first, called Contextual Analysis on the children of leprosy patients in preventoriums aimed to record the phenomenon of children of leprosy patients in preventorium through four contextual levels, which identified the need to broaden the debate on public policy in the field of leprosy as a way to enable more effective measures to propagate in the search for harm reduction and direct consequences resulting from stigma and marginalization around patients and their healthy children, egress from preventoriums. The second, Leprosy and the denial of history: the story of separated children , aimed to know the life trajectory of children of leprosy patients who were institutionalized in preventoriums / educational establishments. In this article, we discuss the research question through the establishment of three main themes: 1. Losses and damages: disintegration and reintegration into the family and denied childhood; 2. Unforgettable: remarkable things you do not forget; and 3. Expectancy in living new situations: in search of other paths and destinations. These thematic axis highlighted the negative implications for the lives of the subjects, arising from the separation of their parents, leprosy patients at the time of compulsory isolation; however, has also been shown that this separation was not decisive in their life histories, once they have succeeded in providing a new sense of these experiences and lead their lives with dignity and fortitude. It was concluded that these children demonstrated resilience as form of defense and fighting stigma and prejudice, being able to reinvent themselves and build new paths and destinations