Isolation of a new Mexican strain of Bacillus subtilis with antifungal and antibacterial activities.

Although several strains of B. subtilis with antifungal activity have been isolated worldwide, to date there are no published reports regarding the isolation of a native B. subtilis strain from strawberry plants in Mexico. A native bacterium (Bacillus subtilis 21) demonstrated in vitro antagonistic activity against different plant pathogenic fungi. Under greenhouse conditions, it was shown that plants infected with Rhizoctonia solani and Fusarium verticillioides and treated with B. subtilis 21 produced augment in the number of leaves per plant and an increment in the length of healthy leaves in comparison with untreated plants. In addition, B. subtilis 21 showed activity against pathogenic bacteria. Secreted proteins by B. subtilis 21 were studied, detecting the presence of proteases and bacteriocin-like inhibitor substances that could be implicated in its antagonistic activity. Chitinases and zwittermicin production could not be detected. Then, B. subtilis 21 could potentially be used to control phytopathogenic fungi that infect strawberry plants.

[Factors associated with delayed hospital treatment for patients with acute cerebrovascular disease]. / Factores asociados a la demora del tratamiento hospitalario de los pacientes con enfermedad cerebrovascular aguda.

INTRODUCTION: Cerebrovascular diseases are an important cause of morbidity and mortality in the world and the effectiveness of thrombolytic therapy depends on early intervention. AIMS: To determine the time taken for patients with acute cerebrovascular events to reach hospital and to observe the variables associated to a longer delay. PATIENTS AND METHODS: We conducted a retrospective, descriptive study of 151 patients treated for acute cerebrovascular events between September 2003 and September 2004 at the Hospital Nacional Cayetano Heredia (Lima, Peru). We searched the records for the time taken to reach hospital, demographic variables and cerebrovascular risk factors, and we observed whether they exerted a significant effect on the arrival time. RESULTS: It was found that 29.8% of patients with an acute cerebrovascular event go to hospital within the first three hours; the mean arrival time is 51.11 hours. In contrast, 51% of patients go to hospital after more than 12 hours. Taking three and six hours as the cut-off points, uni and multivariate analyses showed ischemic stroke to be linked to a longer delay; a diagnosis of atrial fibrillation is associated to a shorter delay in arrival time in the multivariate analysis if a cut-off time of three hours is taken into account. CONCLUSIONS: Despite the high percentage of patients who take a long time to visit hospital following a cerebrovascular event, approximately a third of the patients would benefit from early treatment with thrombolytic therapy.

Polyembryony and apomixis in Eriotheca pubescens (Malvaceae - Bombacoideae).

Apomixis and adventitious polyembryony have been reported for several species of Bombacoideae, including Eriotheca pubescens, a tree species of the Neotropical savanna (Cerrado) areas in Brazil. However, the origin of polyembryonic seeds and their importance for the reproduction of the species remained to be shown. Here, we analyzed the early embryology of this species to establish the apomictic origin of extranumerary embryos. We also observed the geographic distribution of polyembryony in E. pubescens, and tested if apomixis was related to the source of pollen (self or cross) and population density. Moreover, we tested if polyembryonic apomictic embryos would develop normally into seedlings. In the observed seed primordia, after a relatively long quiescent period, the zygote developed into a sexual embryo concurrently with adventitious apomictic embryos which developed from nucellus cells. Adventitious embryos develop faster than sexual ones and are morphologically similar, so that 44 days after anthesis it was virtually impossible to distinguish and trace the fate of the sexual embryo. Polyembryony is widely distributed in populations some 400 km distant, and only one strictly monoembryonic individual was observed during the study. The number of embryos per seed varied between fruits and individuals but was significantly higher in seeds from cross-pollinations than from selfs, although fruit and seed set after crosses were much lower than after selfs. Embryo development into seedlings depended on their weight at germination, but polyembryonic seeds germinated and produced up to seven seedlings per seed in greenhouse conditions. Adventitious embryony and apomictic seedlings would explain the mostly clonal populations suggested by molecular studies.

Use of plastic films in grain stores.

A laboratory study of wheat stored at two different levels of moisture content with and without presence of Sitophilus zeamais Motschulsky was performed. Flexible PVC and polythene films as seals were used in order to examine their effectiveness to maintain the wheat quality by comparing changes in moisture content, germination and weight loss. The PVC film showed a high water vapor permeability and it behaved as the permeable muslin control, keeping the grain quality in all tested conditions. The polythene film showed a low water vapor permeability and it allowed the insects development. It seems that plastic films may be useful in grain stores bearing in mind their properties, adequate sealing and protecting them from insect damage, besides they should be selected according to environmental conditions.

Use of plastic films in grain stores

A laboratory study of wheat stored at two different levels of moisture content with and without presence of Sitophilus zeamais Motschulsky was performed. Flexible PVC and polythene films as seals were used in order to examine their effectiveness to maintain the wheat quality by comparing changes in moisture content, germination and weight loss. The PVC film showed a high water vapor permeability and it behaved as the permeable muslin control, keeping the grain quality in all tested conditions. The polythene film showed a low water vapor permeability and it allowed the insects development. It seems that plastic films may be useful in grain stores bearing in mind their properties, adequate sealing and protecting them from insect damage, besides they should be selected according to environmental conditions