Uncovered Ones Research Articles

Polinização em cultura de laranja (Citrus sinensis L. Osbeck, var. Pera-Rio)

Pollination in sweet orange crop, Citrus sinensis L. Osbeck, var. Pera-Rio. The present experiment was performed to study the frequency and behaviour of insects on sweet orange flowers, Citrus sinensis (L.) Osbeck, the effect these insects on fruit production (quantity and quality) besides measurements of the collection type of more frequent bees. During three consecutive years the more frequent insect visiting the flower was Apis mellifera (africanized). The flowers visited by few or neither honey bees (until 9 visits) showed minor percentage of fruition. The fruit production was 35.30% greater in uncovered flowers. The mean weight of fruits was too greater in uncovered flowers (180.2g) than covered ones (168.5g). The fruits from the covered treatments were more acids (1.411g citric acid/100ml of juice) than uncovered ones (1.164g citric acid/100ml of juice). The number of seeds per bud was higher in uncovered treatment (1 seed/bud) than covered one (0.8 seed/bud).

In vivo and in vitro evaluation of vitreous coatings on cobalt base alloys for prosthetic devices

This work describes the electrochemical and biological response of wires of CrCoMo surgical alloys (F75) covered by two layers of SiO 2 coating prepared by sol–gel to evaluate their properties in simulated body fluids and implanted in Lew rats for the in vivo evaluation. Wires were coated by a single layer of hybrid silica (that means that the coating contains Si–CH 3 groups) covered by another similar layer containing a suspension of bioactive glass-ceramic particles in the system CaO–SiO 2–P 2O 5 to provide fixation to bone. Standard electrochemical tests were conducted for the in vitro measurements and showed smaller current density for the covered samples than for the uncovered ones after 30 days of immersion. For the in vivo tests the coated wires were inserted in the tibia cortical bone by a press fit technique in Lew rats and analysed after 53 days of being implanted. We observed that none of the wires created an inflammatory response. Moreover the covered wires developed neo formed bone in the surroundings of the samples made of collagen with a vascular development. Uncovered wires did not develop new histionic structure.

Guided bone regeneration using osteopatite granules and polytetrafluoroethylene membranes.

Granules of a modified hydroxyapatite, Osteopatite, were implanted in the right posterior tibiae of adult rabbits. We studied the extent of bone regeneration in bone holes. In the right tibiae, that were filled with granules of this biomaterial covered with a polytetrafluoro-ethylene (PTFE) membrane using, as a control, uncovered granules. In the left tibia, an empty hole was covered with PTFE membrane and a second hole was left empty to be used as a control. A histomorphometric study was carried out using light microscopy, four and eight weeks after the surgery. The covered granules presented a higher percentage of bone contact than the uncovered ones, and it was also possible to observe a better bone tissue organization, mainly produced by the immobilization action of the PTFE membrane. Empty bone defects covered with PTFE membranes, two months after implantation, presented large areas of Haversian bone and direct bone contact to the PTFE membrane.

Manejo del racimo y los retoños para rendimientos rentables y frutos de alta calidad en guineos (Musa acuminata, AAA)

Se llevaron a cabo dos experimentos para estudiar los efectos de enfundar los racimos, remover las manos inferiores del racimo y seleccionar los hijuelos sobre las características del fruto, el racimo y en el rendimiento total. En ambos experimentos se obtuvieron datos por 40 meses. La producción media de los racimos cubiertos con bolsas de polietileno perforadas tratadas con el insecticida Dursban al 1% y sin tratar fue de 10,539 kg/ha más que en los racimos sin enfundar. Considerando el precio que se paga por el guineo de alta calidad empacado en la finca y el costo de cubrir el racimo (materiales y mano de obra), el uso de esta práctica resulta en una ganancia neta de $3,329.25/ha. La remoción de las tres manos inferiores del racimo inmaduro redujo significativamente el peso medio final de los racimos y el rendimiento total. Sin embargo, el eliminar manos y el enfundar los racimos aumentaron substancialmente el tamaño y el peso de las frutas individuales en la mano distal, con lo que mejoró la calidad de los frutos. Ambas prácticas, además, acortaron el tiempo entre la floración y la cosecha. La selección de un hijuelo de "lanza" vigoroso inmediatamente después de la siembra seguido de la poda continua de otros hijuelos competidores produjo el mayor rendimiento equivalente a 183,744 kg/ha de frutos.

Factors Influencing Mortality and Nesting in Managed Populations of the Sunflower Leafcutter Bee (Hymenoptera: Megachilidae)

Modified nesting units were field tested to determine effect on egg and larval mortality of Eumegachile pugnata (Say). Units covered with aluminum foil to reflect sunlight reduced within-nest temperatures. Mortality in foil-covered units was significantly lower (6.5%) than in uncovered ones (14.2%).