286 research outputs found
The conceptual structure of evolutionary biology: A framework from phenotypic plasticity
In this review, I approach the role of phenotypic plasticity as a key aspect of the conceptual framework of evolutionary biology. The concept of phenotypic plasticity is related to other relevant concepts of contemporary research in evolutionary biology, such as assimilation, genetic accommodation and canalization, evolutionary robustness, evolvability, evolutionary capacitance and niche construction. Although not always adaptive, phenotypic plasticity can promote the integration of these concepts to represent some of the dynamics of evolution, which can be visualized through the use of a conceptual map. Although the use of conceptual maps is common in areas of knowledge such as psychology and education, their application in evolutionary biology can lead to a better understanding of the processes and conceptual interactions of the complex dynamics of evolution. The conceptual map I present here includes environmental variability and variation, phenotypic plasticity and natural selection as key concepts in evolutionary biology. The evolution of phenotypic plasticity is important to ecology at all levels of organization, from morphological, physiological and behavioral adaptations that influence the distribution and abundance of populations to the structuring of assemblages and communities and the flow of energy through trophic levels. Consequently, phenotypic plasticity is important for maintaining ecological processes and interactions that influence the complexity of biological diversity. In addition, because it is a typical occurrence and manifests itself through environmental variation in conditions and resources, plasticity must be taken into account in the development of management and conservation strategies at local and global levels
The evolutionary ecology of interactive synchronism: The illusion of the optimal phenotype
In this article, we discuss some ecological-evolutionary strategies that allow synchronization of organisms, resources, and conditions. Survival and reproduction require synchronization of life cycles of organisms with favourable environmental and ecological features and conditions. This interactive synchronization can occur directly, through pairwise or diffuse co-evolution, or indirectly, for example, as a result of actions of ecosystem engineers and facilitator species. Observations of specific interactions, especially those which have coevolved, may give the false impression that evolution results in optimal genotypes or phenotypes. However, some phenotypes may arise under evolutionary constraints, such as simultaneous evolution of multiple traits, lack of a chain of fit transitional forms leading to an optimal phenotype, or by limits inherent in the process of selection, set by the number of selective deaths and by interference between linked variants. Although there are no optimal phenotypes, optimization models applied to particular species may be useful for a better understanding of the nature of adaptations. The evolution of adaptive strategies results in variable life histories. These strategies can minimize adverse impacts on the fitness of extreme or severe environmental conditions on survival and reproduction, and may include reproductive strategies such as semelparity and iteroparity, or morphological, physiological, or behavioural traits such as diapause, seasonal polyphenism, migration, or bet-hedging. However, natural selection cannot indefinitely maintain intra-population variation, and lack of variation can ultimately extinguish populations
Quality of life as a prognostic marker in pulmonary arterial hypertension
Background: Improvement in quality of life together with better survival are the ultimate goals in the treatment of pulmonary arterial hypertension (PAH) patients. the objective of this study was to evaluate the health-related quality of life (HRQL) of pulmonary arterial hypertension (PAH) patients with the SF-36 generic questionnaire and to identify the prognostic implication of this assessment.Methods: Fifty-four consecutive newly diagnosed PAH patients (WHO classification group I) in a single PAH reference center were included. Patients were evaluated at baseline for clinical and hemodynamic parameters, and they subsequently received first-line therapy with either an endothelin receptor antagonist or a phosphodiesterase-5 inhibitor. After 16 weeks of specific PAH therapy, all patients were re-evaluated using a 6MWT and a SF 36 questionnaire, and then they were followed up for at least 36 months.Results: After treatment, the patients demonstrated an improved 6MWT (414 +/- 124 m vs. 440 +/- 113 m, p = 0.001). Specific PAH therapy also improved the HRQL scores.Patients with a baseline Physical Component Score (PCS) higher than 32 had a better survival rate than those who had a score under 32 (p = 0.04). Similarly, patients with a PCS of at least a 38 after the 16 week therapy period had a better survival rate when compared with those who did not achieve this value (p = 0.016). Unlike the absolute PCS values, the post-treatment PCS variability was unable to predict better survival rates (p = 0.58).Conclusions: Our findings suggest that HRQL is associated with prognosis in PAH. Furthermore, achieving pre-determined PCS scores might represent a specific goal to be reached in treatment-to-target strategies.Univ São Paulo, Sch Med, Pulm Dept, Inst Heart, BR-05403000 São Paulo, BrazilUniversidade Federal de São Paulo, Rheumatol Dept, São Paulo, BrazilUniversidade Federal de São Paulo, Rheumatol Dept, São Paulo, BrazilWeb of Scienc
Avaliação econômica da estação de monta em caprinos utilizando protocolo de sincronização do estro e ração flushing.
Resumo: O objetivo deste estudo foi realizar uma análise econômica do protocolo de sincronização do estro mais a ração flushing oferecida as cabras durante a estação de monta. Foram selecionadas 12 cabras da raça Saanen e um reprodutor, recebendo ração flushing. Utilizou-se esponjas análogas a progesterona, Prostaglandina e Gonadotrofina Coriônica Equina. O custo total foi de R 46,17/animal. The use of protocol of sychronization of estrous is more economically viable the sum natural
Avaliação econômica de dietas formuladas conforme o NRC (2007) com e sem restrição de energia e proteína na terminação de cordeiros em confinamento.
O ovinocultor para realizar sua tomada de decisão, deve ficar atento aos itens envolvidos com a alimentação, que é a chave do sucesso para que sua atividade seja produtiva e lucrativa. Portanto, estudos que avaliem a eficiência do uso de diferentes dietas poderão contribuir com a busca da eficiência produtiva e econômica da terminação de cordeiros em confinamento. Dessa forma, objetivou-se avaliar o custo de diferentes dietas utilizadas na alimentação de ovinos terminados em confinamento.Edición de las Memorias de la 25a. Reunión de la Asociación Latinoamericana de Producción Animal (ALPA), 2016, Recife, Brasil
Fertilidade e prolificidade de ovinos criados em diferentes sistemas de produção na região Norte do Ceará.
Resumo: Na região semi-árida do Nordeste brasileiro, a exploração de ovinos deslanados é efetuada para produção de carne e pele, porém o desempenho reprodutivo é baixo, principalmente pelas práticas de manejo deficientes, aliadas às limitações de ordem nutricional impostas pelas condições climáticas no semi-árido nordestino. Objetivou-se produzir informações que permitam subsidiar a tomada de decisão para criação de ovinos no Estado do Ceará. Foram estimados no presente trabalho indicadores zootécnicos relacionados com reprodução de ovinos de três Fazendas criados em diferentes sistemas de produção. As características reprodutivas estudadas foram: fertilidade (o número de ovelhas paridas por matrizes expostas), prolificidade (o número de crias por matriz por parto). A fertilidade e prolificidade média das três Fazendas foram iguais a 82,10 e 1,28, respectivamente. A fertilidade para as Fazendas foram iguais a 74,71 (Fazenda 1), 89,56 (Fazenda 2) e 82,04 (Fazenda 3) e prolificidade de 1,14 (Fazenda 1), 1,27 (Fazenda 2) e 1,45 (Fazenda 3). O sistema de produção foi fator determinante para fertilidade e prolificidade. [Fertility and prolificacy of sheep created in different production systems in the North Region of Ceara]. Abstract: In semi-arid northeast region of Brazil, the sheep exploitation is for production of meat and skin, but the reproductive performance is low, mainly by poor management practices, combined with nutritional limitations of order imposed by weather conditions in the northeast semi-arid. The aimed of this study was to produce information to make decision about how breeding system should be used in the North region of Ceara State. Zootechnical index of sheep production of three herds breeded in different production systems was studied. The reproductive traits were the number of sheep calved by matrices exposed (fertility), the number of lamb per ewe per calving (litter size/prolificacy) and the interval between births. The mean fertility and prolificacy for the three herds were equal to 82.10 and 1.28. The average fertility for the herds 1, 2 and 3 respectively was equal to 74.71, 89.56 and 82.04 and the average of prolificacy was the same order of 1.14, 1.27 and 1.45. The production system was determining factor for fertility and prolificacy
Economic-financial analysis of the use of the detoxified castor by alkaline solutions I: production of arrays of dairy goats.
Abstract: We evaluated the influence of totally substituting soybean meal (SM) with detoxified castor cake (DCC) and two alkaline products on the economic and financial viability of producing Saanen and Anglo-Nubian goat dairy breeds with initial body weights of 16.22 ± 0.67 kg that had been confined until they were capable of reproduction (70% of total body weight). The goats were subjected to six simulated production systems (PS). These were PS1, rearing Saanen goats that were fed with a standard diet based on SM; PS2, rearing Anglo-Nubian goats that were fed with a standard diet based on SM; PS3, rearing Saanen goats that where fed with a standard diet based on DCC Ca(OH)2; PS4, rearing Anglo-Nubian goats that were fed with a standard diet based on DCC Ca(OH)2; PS5, rearing Saanen goats fed with a standard diet based on DCC NaOH; and PS6, rearing Anglo-Nubian goats that were fed with a standard diet based on DCC NaOH. A descriptive economic and financial evaluation of the data was carried out using AVETEC® software. The SM based diets cost approximately 58.70% and 66.22% more for the Saanen and the Anglo-Nubian goats than the other diets, respectively. The results showed that all the scenarios had a point of leveling (PL) values of less than 144 goats, which is the number of animals that can be produced annually by each system simulated in this research. The net revenue for all the systems was greater than zero, which indicated that their activities were stable and that the internal rates of return were high. The profitability indices were also very good, especially the systems that used Saanen goats, because the NPV were higher than 1 million reais. Sensitivity analyzes showed that the indicators of performance were only economically unviable under the least favorable situations, such as 30% reductions in both production and market price. The use of the DCC does not compromise the economic viability of the systems and produces higher returns than the systems that used the standard (SM) diet. [Análise econômico-financeira do uso da torta de mamona destoxificada por soluções alcalinas I: produção de matrizes de cabras leiteiras]. Resumo: Avaliou-se a influência da total substituição do farelo de soja (FS) pela torta de mamona destoxificada (TMD) por dois produtos alcalinos sobre a viabilidade econômico-financeira na produção de matrizes leiteiras das raças Saanen e Anglo Nubiana, com peso corporal inicial de 16,22 ± 0,67 kg confinadas até a formação de matrizes aptas a reprodução (70% do peso vivo corporal). Foram simulados seis sistemas de produção (SP), sendo: SP1, criação de cabritas Saanen alimentadas com dieta padrão à base de FS; SP2, criação de cabritas Anglo Nubianas alimentadas com dieta padrão à base de FS; SP3, criação de cabritas Saanen alimentadas com dieta à base de TMD Ca(OH)2; SP4, criação de cabritas Anglo Nubianas alimentadas com dieta à base de TMD Ca(OH)2; SP5, criação de cabritas Saanen alimentadas com dieta à base de TMD NaOH; SP6, criação de cabritas Anglo Nubianas alimentadas com dieta à base de TMD NaOH. A avaliação econômico-financeira dos dados foi realizada de forma descritiva, utilizando-se o software AVETEC®. Os maiores custos com alimentação foram observados nos sistemas que utilizaram as dietas a base de FS, cerca de 58,70% para as cabras Saanen e 66,22% para as Anglo Nubianas. A simulação para produção de 144 matrizes leiteiras proporcionou receita superior aos custos de produção, resultando em indicadores econômicos positivos para todos os cenários avaliados. Observou-se que todos os cenários tiveram ponto de nivelamento (PN) inferior a 144 cabras que é a quantidade de animais que podem ser produzidas anualmente para cada sistema simulado nesta pesquisa. A receita líquida de todos os sistemas foi maior que zero, o que indica que a atividade é estável, apresentando altas taxas internas de retorno. Da mesma forma, os índices de lucratividade são bem atrativos, principalmente os sistemas que optarem pela cria de cabras da raça Saanen, onde os VPLs são superiores há um milhão de reais. As análises de sensibilidade mostraram que apenas nas situações mais desfavoráveis, tais como a redução de 30% tanto na produção quanto no preço de mercado, os indicadores são economicamente inviáveis. O uso das TMD não compromete a viabilidade econômica dos sistemas, porém quando comparados aos sistemas que utiliza a dieta padrão, apresentam menor rentabilidade
Estimating the global conservation status of more than 15,000 Amazonian tree species
Estimates of extinction risk for Amazonian plant and animal species are rare and not often incorporated into land-use policy and conservation planning. We overlay spatial distribution models with historical and projected deforestation to show that at least 36% and up to 57% of all Amazonian tree species are likely to qualify as globally threatened under International Union for Conservation of Nature (IUCN) Red List criteria. If confirmed, these results would increase the number of threatened plant species on Earth by 22%. We show that the trends observed in Amazonia apply to trees throughout the tropics, and we predict thatmost of the world’s >40,000 tropical tree species now qualify as globally threatened. A gap analysis suggests that existing Amazonian protected areas and indigenous territories will protect viable populations of most threatened species if these areas suffer no further degradation, highlighting the key roles that protected areas, indigenous peoples, and improved governance can play in preventing large-scale extinctions in the tropics in this century
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