Effect of simulated extreme rainfall on the vegetative phenology of perennial and annual herbaceous plants from a Brazilian dry forest.

Detecting changes in the phenological responses of herbaceous species as a function of predicted climate change is important for forecasting future scenarios for the functioning of dry tropical forests, especially when predicting an increase in the frequency and intensity of extreme droughts. Because of the sensitivity of plants to water availability, our study hypothesizes that if years become drier or wetter, herbaceous plants will synchronously change the onset, duration, and intensity of their vegetative phenophases. We used a historical series of 60 years of precipitation observations for the Caatinga vegetation to define daily average of precipitation for rainy (Twet), median (Tcontrol), and dry (Tdry) years. We simulated past average daily rainfall (Twet, Tcontrol, and Tdry) while growing two herbaceous perennials and two herbaceous annuals. We monitored plant growth and measured the activity (absence or presence) and intensity of vegetative phenophases. We used circular statistical analysis to assess differences between treatments. Our results revealed that leaf production was seasonal but relatively uniform for perennial species and highly seasonal (wet season) for annual species. Simulated dry years induced lower leaf emergence concentrated over a few months in annual species, but this effect was more strongly significant in one of the two perennial species. Both annual and perennial species can experience delayed and less intense leaf abscission during the rainy season in years with below-average precipitation. In contrast, large voluminous rains in years with above-average precipitation can accelerate and intensify the process of leaf renewal. If future precipitation reductions occur, the changes in phenological response indicate that the cover of annual and perennial herbaceous species in this study will likely decrease, altering the landscape and functioning of dry tropical forests. However, the potential trade-offs observed may help populations of these species to persist during years of severe drought in the Caatinga.

Refluxo gastroesofágico na criança: tratamento cirúrgico pela técnica de Nissen / Gastroesophageal reflux in children: surgical treatment by Nissen's technique

Objetivo. Analisar os resultados da fundoclipatura de Nissen no tratamento do refluxo gastroesofágico (RGE) na criança. Material e Métodos. Foi realizado um estudo retrospectivo de 185 crianças portadoras de RGE, diagnosticado através de seriografia esofagogastroduodenal (SEGD), e internadas no Hospital Infantil Joana de Gusmao, Florianópolis, SC, no período de fevereiro de 1981 a junho de 1989. Foram revisados os seguintes dados dos prontuários: idade, sexo, quadro clínico, exames complementares, indicaçoes cirúrgicas, tratamento pré-operatório, tratamento cirúrgico pela tecnica de Nissen, complicaçoes trans e pós-operatórias e resultados divididos em bom (ausência de RGE), mau (recidiva), desconhecido (sem acompanhamento) e óbitos. Resultados. A idade variou de trinta dias a 7 anos e houve prevalência do sexo masculino (2:1). As manifestaçoes clínicas mais frequentes foram vômitos (85,40 por cento), distúrbios respiratórios (64,32 por cento) e desnutriçao (55,13 por cento). A SEGD demonstrou refluxo isolado (40 por cento), associado hérnia hiatal (18,91 por cento) e complicado com esofagite (29,18 por cento) e estenose (11,89 por cento). No transoperatório houve perfuraçao inadvertida do esôfago terminal em um caso (0,54 por cento). As complicaçoes pós-operatórias mais frequentes foram a síndrome da bolha gasosa (7,02 por cento) e o edema do esôfago terminal (5,94 por cento). O resultado foi bom para 159 crianças (85,94 por cento), mau em sete (3,78 por cento) e desconhecido em 11 (5,94 por cento). Ocorreram oito óbitos (4,32 por cento): um (0,54 por cento) relacionado a afecçao, um (0,54 por cento) com a cirurgia e seis (3,24) atribuidos a causas clínicas.