Seasonal cambial activity was investigated in one-to three-year-old branch modules (branch constructional units) of ten woody species from cerrado sensu stricto, a savanna-like ecosystem, of southern Brazil. Relationships between cambial activity and environmental factors (precipitation, temperature, day length) and leaf production were tested using GLMM. Regardless the plant habit and leaf shedding patterns, cambial activity (about 5 months) corresponded to the core of the rainy season (when at least 66% of the annual precipitation had been reached), even though there was some delay or advance in the timing of cambial activity depending on the branch age or species. Cambial activity began in the dry season and ceased before the end of rainy season. Although cambial activity has been positively correlated with day length, precipitation, temperature, and budding for all species, day length, among the assessed factors, seems to be the best predictor of onset and cessation of cambial activity in the branch modules of cerrado species.
The Mediterranean fruit fly (Medfly), Ceratitis capitata (Wiedemann) is one of the major pests of fruit crops in Argentina and it is a phytosanitary barrier to the export of fresh fruits. In the Province of San Juan, located in the central-eastern region of Argentina known as Cuyo, control strategies against Medfly in fruit-producing irrigated-valleys have been implemented by the National Fruit Fly Control and Eradication Program (ProCEM) jointly with the provincial government and the producers. This program uses an area-wide integrated pest management approach that includes the use of environment-friendly strategies to suppress or eradicate Medfly, such as the use
Key message Cambial dormancy in a tropical evergreen species is long lasting, and the initiation of cambial activity is related to day length. Abstract Studies on cambial activity allow us to understand the growth dynamics of plants. In this study, we investigate cambial activity and the conducting phloem in a population of an evergreen shrubby species from a semideciduous tropical forest with distinct wet and dry seasons. Stem samples from Cordiera concolor were collected bimonthly in 2010 and prepared according to the standard methods for plant anatomy. The relationship between cambial activity and climate factors as well as phenology was investigated using Spearman's correlation. The cambium is dormant during the rainy season and dormancy lasted up to 9 months. Cambial activity was positively related to day length, and although it occurred in the rainy season, the period of its onset and termination was not concurrent with the beginning and end of the rainy season. The conducting phloem corresponded most to the noncollapsed phloem and was present year-round, ranging in width (in transverse section) from 62 lm in the rainy season to 112 lm in the dry season. Together, these results illustrate that cambial activity in an evergreen species of a seasonal tropical forest is seasonal with long-lasting cambial dormancy, and that at least some conducting phloem is present year-round.
A B S T R A C TExperimental manipulations are essential for understanding the causal factors of plant growth and cambial activity. Here, we studied the potential effect of water availability and natural variation of day length and temperature on cambial activity in Cordiera concolor (Cham.) Kuntze, an evergreen tropical species. Experiments were conducted in a greenhouse using ninety one-year-old plants divided into two groups. Each group was observed for five weeks during two different times of the year (early spring and late summer). Plants were subjected to three distinct water regimes (waterlogging, field capacity and water deficit). Temperature and day length were recorded daily and stem samples were taken weekly during both sampling intervals. Anatomical procedures were used to describe the cambial activity per stem. Our results suggest that soil water content and its influence on cambial activity depend on the time of year, while cambial stimulus was positively related to day length, independent of the time of year. In early spring, cambial activity was stimulated by an increase of day length, regardless of water supply. In contrast, in late summer, cambial dormancy was delayed in waterlogged plants and advanced in plants subjected to a water deficit, followed by decreasing day length. Analyses of the wood anatomy showed that the marginal bands of axial parenchyma were initial. Our study highlights a more complex scenario of plant functioning and its causal factors in tropical systems.
análise parasitológica. De 82 peixes analisados, todos apresentaram pelo menos uma espécie de parasito. Durante as amostragens foram medidos o pH, o oxigênio dissolvido, a condutividade elétrica e a temperatura da água, bem como a temperatura ambiente e as condições do tempo nos dois dias que precederam a coleta. Os maiores valores de prevalência e intensidade média de infecção foram observados por Monogenoidea (
Background:
Little is known about the burden of Kawasaki disease (KD) in Latin America (LA). The LA KD network (REKAMLATINA) was established in 2013 and has 120 physicians in over 85 hospitals in 20 countries. It’s goal is to characterize the epidemiology of KD in LA children, to understand the disease impact, and plan for studies that address the specific needs of LA children with KD.
Methods:
Retrospective review of 437 children 1 echo, worst CA status was evaluated for either the RCA or LAD. IVIG therapy response was classified as resistant (fever ≥38C more than 36 hrs after completion of IVIG), responsive or unknown.
Conclusions:
This is the first multicenter report describing the clinical course and treatment of KD in LA. Differences in the care of KD patients were observed among participating countries, specially regarding obtaining echos at baseline and follow up. Also, KD could be an important cause of antibiotic misuse in LA. More research is needed to describe how KD care in LA is influenced by local and economical factors, the available resources, and to standardize treatment in resource- limited settings.
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