Effect of yeast and essential oil-enriched diets on critical determinants of health and immune function in Africanized Apis mellifera.

Nutrition is vital for health and immune function in honey bees (Apis mellifera). The effect of diets enriched with bee-associated yeasts and essential oils of Mexican oregano (Lippia graveolens) was tested on survival, food intake, accumulated fat body tissue, and gene expression of vitellogenin (Vg), prophenoloxidase (proPO) and glucose oxidase (GOx) in newly emerged worker bees. The enriched diets were provided to bees under the premise that supplementation with yeasts or essential oils can enhance health variables and the expression of genes related to immune function in worker bees. Based on a standard pollen substitute, used as a control diet, enriched diets were formulated, five with added bee-associated yeasts (Starmerella bombicola, Starmerella etchellsii, Starmerella bombicola 2, Zygosaccharomyces mellis, and the brewers' yeast Saccharomyces cerevisiae) and three with added essential oils from L. graveolens (carvacrol, thymol, and sesquiterpenes). Groups of bees were fed one of the diets for 9 or 12 days. Survival probability was similar in the yeast and essential oils treatments in relation to the control, but median survival was lower in the carvacrol and sesquiterpenes treatments. Food intake was higher in all the yeast treatments than in the control. Fat body percentage in individual bees was slightly lower in all treatments than in the control, with significant decreases in the thymol and carvacrol treatments. Expression of the genes Vg, proPO, and GOx was minimally affected by the yeast treatments but was adversely affected by the carvacrol and thymol treatments.

Nectar-living yeasts of a tropical host plant community: diversity and effects on community-wide floral nectar traits.

We characterize the diversity of nectar-living yeasts of a tropical host plant community at different hierarchical sampling levels, measure the associations between yeasts and nectariferous plants, and measure the effect of yeasts on nectar traits. Using a series of hierarchically nested sampling units, we extracted nectar from an assemblage of host plants that were representative of the diversity of life forms, flower shapes, and pollinator types in the tropical area of Yucatan, Mexico. Yeasts were isolated from single nectar samples; their DNA was identified, the yeast cell density was estimated, and the sugar composition and concentration of nectar were quantified using HPLC. In contrast to previous studies from temperate regions, the diversity of nectar-living yeasts in the plant community was characterized by a relatively high number of equally common species with low dominance. Analyses predict highly diverse nectar yeast communities in a relatively narrow range of tropical vegetation, suggesting that the diversity of yeasts will increase as the number of sampling units increases at the level of the species, genera, and botanical families of the hosts. Significant associations between specific yeast species and host plants were also detected; the interaction between yeasts and host plants impacted the effect of yeast cell density on nectar sugars. This study provides an overall picture of the diversity of nectar-living yeasts in tropical host plants and suggests that the key factor that affects the community-wide patterns of nectar traits is not nectar chemistry, but rather the type of yeasts interacting with host plants.

[The family: the support for the elderly with cerebral-vascular accident]. / La familia, el bastón del anciar con accidente cerebro-vascular.

This project had these objectives: 1) understand the reality of the family care system for an elderly person suffering from cerebral-vascular accident (CVA), 2) implement an aid to the family care system for an elderly person suffering from cerebral-vascular accident (CVA) from a holistic perspective on health. The sample for this investigation was composed by five families which were intentionally selected, with whom the authors shared the care of an elderly person suffering from CVA in their homes over a six month period. Based on concepts having a holistic reference about health formulated by Capra, the authors drew up the development of a methodology for research and action which has a participatory observation and a Drawing-Record procedural technique for the production of data. These data were subjected to a thematic analysis which made it possible to identify three main themes: 1) the main caretaker as the focus of the family care system; 2) the family care system as a context which has complexities and singularities, 3) the holistic nature of the family care system for an eldely person suffering from cerebral-vascular accident (CVA).