Natural dispersion of seeds: importance, classification and dynamics

The plant propagation by seed dispersion is recognized as one of the fundamental factors that affect the recruitment of the plants and is an important step of the reproductive cycle of most of them. The dispersion reduces the predation levels in the proximities of adult plants of the same species, increases the chance of seed germination and establishes new habitats favorable to the colonization. Besides, the dispersion of seeds also generates wider spacial distribution of adult plants population. The importance of natural seeding in the renewal and persistence of species in pastures is recognized, but it is a little known subject, the understanding of the dispersion process under a new perspective from the point of view of modern, sustainability based, production models, where wild animals are compatible with agricultural production based on pastures. With this revision, it was aimed to trace the path of the studies on dispersion of seeds, with emphasis in the classification systems, the types, the dispersers, the seeds dispersion processes among habitats, the evaluation of the dispersion potential of vegetable species through ruminant, and the applications and current limitations of seeds dispersion, and contribute for construction of a new development conception based in sustainability of the agricultural production systems.A propagação de plantas pela dispersão de sementes é reconhecida como um dos fatores fundamentais que afetam o recrutamento das plantas e é um importante passo do ciclo reprodutivo da maioria delas. A dispersão reduz os níveis de predação nas proximidades dos adultos da mesma espécie, aumenta as chances de germinação das sementes e estabelece novos habitats favoráveis a colonização. Além disso, a dispersão de sementes também gera a distribuição espacial dos indivíduos adultos da população. Embora seja reconhecida a importância da ressemeadura natural na renovação e persistência de espécies em pastagens, o entendimento do processo de dispersão sob nova perspectiva dentro dos modernos modelos de produção, que se pautam na sustentabilidade, onde temos, lado a lado, animais silvestres e produção pecuária baseada em pastagens é um assunto pouco conhecido. Com essa revisão, objetivou-se traçar a trajetória dos estudos sobre dispersão de sementes, com ênfase nos sistemas de classificação, os tipos, os dispersores, o processo de dispersão de sementes entre habitats, avaliação do potencial de dispersão de espécies vegetais através de ruminantes e as aplicações e limitações atuais da dispersão de sementes, e assim contribuir para a construção dessa nova concepção de desenvolvimento baseada na sustentabilidade dos sistemas de produção agropecuários

Mastigação simulada e digestão ácido-enzimática de sementes de leguminosas forrageiras tropicais #

This study aimed to evaluate the effect of simulated chewing in the laboratory on the survival of seeds of four tropical forage legumes (butterfly pea, Clitorea ternatea; estilosantes, Stylosanthes capitata/S. macrocephala 'Campo Grande; archer, Macrotyloma axillare and perennial soybean, Neonotonia wightii) submitted to different periods of acid enzymatic digestion in vitro. Three trials were conducted to observe the percentage of destroyed seeds by the mastication; to compare the germination of the seeds (intact seeds, simulated mastication, scarification with sand- paper, mastication and scarification with sandpaper). And, finally the seeds were incubated at 39oC with hydrochloric acid and pepsin for: 0, 2, 4, 8, 12 and 24 hours. The percentages of not destroyed seeds in mastication (archer, 91,5; perennial soybean, 88.0; butterfly pea, 82.1, and estilo, 81.1), associated with the beneficial effects of scarification on germination (64.7, 60.0, 92.0 e 87.3%, respectively) and the effects of time of acid-enzymatic digestion (75% higher if they stay 24 hours in HCl + pepsin) associated to the hard and not permeable coats of legume seeds, allow a high potential for resistance, and to pass intact through the digestive tract of cattle, being able to germinate when defecated in the pastures. However, estilo should not be included in the feeding of cattle for this purpose, because it do not resists the acid-enzyme digestionEste trabalho teve por objetivo verificar o efeito da mastigação simulada em laboratório so- bre a sobrevivência de sementes de quatro legu- minosas forrageiras tropicais submetidas a dife- rentes períodos de digestão ácido-enzimática in vitro (cunha, Clitorea ternatea; estilosantes, Stylosanthes capitata/S. macrocephala 'Campo Grande'; macrotiloma, Macrotyloma axillare e soja perene, Neonotonia wightii). Foram conduzidos três ensaios: o primeiro, para observar o percentual de sementes destruídas pela mastigação; o se- gundo, para comparar o comportamento germinativo das sementes após mastigação, escarificação com lixa, mastigação com posterior escarificação com lixa e sementes integras (con- trole). No terceiro ensaio as sementes foram incubadas a 39°C com ácido clorídrico mais pepsina por: 0, 2, 4, 8, 12 e 24 horas. As percentagens de sementes não destruídas na mastigação (91,5 de macrotiloma; 88,0 de soja perene; 82,1 de cunhã e 81,1 de estilosantes), associadas aos efeitos benéficos da escarificação (verificados pela porcentagem de germinação, 64,7; 60,0; 92,0 e 87,3%), e aos efeitos do tempo de digestão ácida- enzimatica (75% maior quando permanecem 24 horas em HCl + pepsina) permitem observar que as sementes de leguminosas, por possuírem tegumentos duros e impermeáveis, quando submetidas à mastigação e à digestão ácido- enzimática, ainda tem um elevado potencial de resistência e, portanto, susceptível de passar intacta pelo aparelho digestivo dos bovinos, sendo capazes de germinar quando defecadas nas pastagens. Contudo, o estilosantes não deve ser inserido na alimentação de bovinos com este fim, pois não resiste à digestão ácido-enzimática

Mastigação simulada e digestão ácido-enzimática de sementes de leguminosas forrageiras tropicais

This study aimed to evaluate the effect of simulated chewing in the laboratory on the survival of seeds of four tropical forage legumes (butterfly pea, Clitorea ternatea; estilosantes, Stylosanthes capitata/S. macrocephala 'Campo Grande; archer, Macrotyloma axillare and perennial soybean, Neonotonia wightii) submitted to different periods of acid enzymatic digestion in vitro. Three trials were conducted to observe the percentage of destroyed seeds by the mastication; to compare the germination of the seeds (intact seeds, simulated mastication, scarification with sandpaper, mastication and scarification with sandpaper). And, finally the seeds were incubated at 39oC with hydrochloric acid and pepsin for: 0, 2, 4, 8, 12 and 24 hours. The percentages of not destroyed seeds in mastication (archer, 91,5; perennial soybean, 88.0; butterfly pea, 82.1, and estilo, 81.1), associated with the beneficial effects of scarification on germination (64.7, 60.0, 92.0 e 87.3%, respectively) and the effects of time of acid-enzymatic digestion (75% higher if they stay 24 hours in HCl + pepsin) associated to the hard and not permeable coats of legume seeds, allow a high potential for resistance, and to pass intact through the digestive tract of cattle, being able to germinate when defecated in the pastures. However, estilo should not be included in the feeding of cattle for this purpose, because it do not resists the acid-enzyme digestion

Impact of pharmaceutical care on the quality of life of patients with Chagas disease and heart failure: randomized clinical trial

<p>Abstract</p> <p>Background</p> <p>Pharmaceutical care is the direct interaction between pharmacist and patient, in order to improve therapeutic compliance, promote adequate pharmacotherapeutic follow-up, and improve quality of life. Pharmaceutical care may be effective in reducing complications and in improving the quality of life of patients with chronic diseases, like Chagas heart disease, while bringing a positive impact on health system costs. The morbidity and mortality indexes for patients with Chagas heart disease are high, especially if this heart disease is complicated by heart failure. In this setting, we hypothesize that pharmaceutical care might be an important tool for the clinical management of these patients by improving their quality of life, as a better compliance to their treatment and the avoidance and prompt correction of drug-related problems will minimize their symptoms, improve their functional class, and decrease the number of hospital admissions. Therefore, the aim of this trial is to evaluate the contribution of pharmaceutical care to clinical treatment of patients with Chagas heart disease complicated by heart failure.</p> <p>Methods/design</p> <p>A prospective, single-center randomized clinical trial will be conducted in patients with Chagas heart disease complicated by heart failure. A total of 88 patients will be randomly assigned into two parallel groups: an intervention group will receive standard care and pharmaceutical care, and a control group will receive only standard care. Both groups will be subjected to a follow-up period of 12 months. The primary outcome of this trial is the evaluation of quality of life, measured by the 36-item short-form and the Minnesota Living with Heart Failure Questionnaire. Secondary outcomes include drug-related problems, exercise tolerance as measured by the standard six-minute-walk test, and compliance.</p> <p>Discussion</p> <p>Patients with Chagas heart disease complicated by heart failure under pharmaceutical care are expected to improve their quality of life, present with a lower incidence of drug-related problems, improve their functional capacity, and improve in their compliance to treatment.</p> <p>Trial registration</p> <p>ClinicalTrials.gov Identifier: NCT01566617</p