Cutting Ability of Nickel-titanium rotary systems protaper, mtwo and k3

Nickel-titanium rotatory systems should remove dentin during the root canal preparation to promote the enlargement and tapered shape with continuously narrowing towards the apex. Objective: The aim of this study was to analyze the cutting ability of three NiTi rotatory systems (n = 12): ProTaper (group 1), Mtwo (group 2), and K3 (group 3). Material and methods: Thirty six maxillary molar teeth were weighted on an analytical balance before and after the rotatory preparation of the mesio-buccal root canal. Data was statistically analyzed by ANOVA and Tukey s test with a significance level of 5%. Results: The results revealed the following mass differences (g) before and after the root canal preparation: ProTaper (group 1 – 0.0159 ± 0.004), Mtwo (group 2 – 0.0125 ± 0.002), and K3 (group 3 – 0.007 ± 0.003). Conclusion: ProTaper showed the highest cutting ability among the three tested nickel-titanium rotatory systems followed by Mtwo and K3.

Human teeth versus bovine teeth: cutting effectiviness of diamond burs

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Comportamento fenológico da liana Pyrostegia venusta (Ker Gawl.) Miers (Bignoniaceae) em área de cerradão na Estação Ecológica de Assis, SP.

Brazilian cerrado is characterized by an evident seasonality with distinct dry and wet seasons. Pyrostegia venusta is a common vine found in different physiognomies of the Cerrado. The species may present characteristics that allow its adjustment to the seasonal cycles. The phenology of vegetative and reproductive events was studied for this species in 2004 and 2005. The objective was to verify which climatic factors determine the phenological patterns observed in the species. Flowering was inversely related to mean temperatures and to the length of the day, while fruiting was inversely related to the photoperiod and directly related to the mean wind velocity. Seed dispersal was directly related to wind speed. As a consequence, flowering occurred at the end of the rainy season, close to the winter, and was prolonged until the end of the dry season. Fruiting and fruit maturation occurred during the dry period, with the seeds being dispersed at the end of this period. The seed dispersal at the end of the dry season, common to other anemochoric species of cerrado, allows a rapid germination at the beginning of the wet season, favoring the species propagation in this environment.

Mitochondrial and peroxisomal population in post-pharyngeal glands of leaf-cutting ants after lipid supplementation

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

What is the stimulus for the excavation of fungus chamber in leaf-cutting ants?

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Comparative study of resistance to heat in two species of leaf-cutting ants

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Acromyrmex charruanus: a new inquiline social parasite species of leaf-cutting ants

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Prospection of genomic regions divergently selected in cutting line of quarter horses in relation to racing line

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

First-year nest growth in the leaf-cutting ants Atta bisphaerica and Atta sexdens rubropilosa

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

The influence of temperature on oxygen consumption rates of workers of two leaf cutting ants, Atta laevigata (F. Smith, 1858) and Atta sexdens rubropilosa (Forel, 1908)

1. 1. The oxygen consumption in workers of two simpatric leaf cutting ants, Atta laevigata and Atta sexdens rubropilosa was measured at different temperatures. 2. 2. In the temperature range between 5-35°C, with 5°C increments, the respiratory rates increased with temperature, but the R-T curves of both ants showed neither a marked drop at the low end nor a break at the high end; except between 30 and 35°C. 3. 3. The respiratory rates of A. s. rubropilosa were higher than those of A. laevigata and in the midrange of temperatures, the rates of A. laevigata increased faster than those of A. s. rubropilosa. 4. 4. Q10 values did not indicate regions of compensation for temperature in both ants, but suggested that adjustments may occur at high temperatures (25-35°C), as expected for tropical ants. 5. 5. Temperature variations did not alter significantly the slope of the curve relating oxygen consumption and body weight in both species. © 1982.

The respiratory metabolism of the castes of two leaf cutting ants, Atta laevigata (F. Smith, 1858) and Atta sexdens rubropilosa forel, 1908

1. 1. The respiration of the different castes of two species of leaf-cutting ants, Atta laevigata and Atta sexdens rubropilosa was measured in both workers and sexed forms. 2. 2. The respiratory rates (μl O2/mg(live)/hr) were, in A. laevigata, 0.644 (gardeners), 0.594 (cutters), 0.354 (soldiers), 0.233 (males) and 0.085 (females); in A. s. rubropilosa, 0.803 (gardeners), 0.748 (cutters), 0.510 (soldiers), 0.375 (males) and 0.274 (females), significantly higher than A. laevigata. 3. 3. All castes considered, the b-values of the equation relating oxygen consumption and weight in A. laevigata (0.53) were significantly different from that in A. s. rubropilosa (0.73). © 1981.

Shared Escovopsis parasites between leaf-cutting and non-leaf-cutting ants in the higher attine fungus-growing ant symbiosis

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Comparative morpho-physiology of the metapleural glands of two Atta leaf-cutting ant queens nesting in clayish and organic soils

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Respiratory regulation in workers of the leaf cutting ant Atta sexdens rubropilosa Forel, 1908

1. Respiratory rates of workers of the leaf cutting ant Atta sexdens rubropilosa were measured at different oxygen pressures, at 25°C. 2. In experiments where different ants were used at each of the oxygen pressures, respiration was regulated down to 70.8 mmHg. 3. When the same ants were submitted in sequence to declining pO2, the 'oxygen dependence indexes' (Tang P.S. (1933) Quart. Rev. Biol. 8, 260-274) also suggested a good regulatory capacity. 4. The results are discussed in terms of the variation of the partial pressures of O2 and CO2 that the ants probably encounter when wandering to and from the nest to forage, and when performing their heavy tasks (leaf transport, offspring and fungus care). 5. CO2 rise and O2 fall, from ants' respiration inside the ant hill, may act as the factors that, in a reflex way, keep the spiracles open and increase ventilation and the frequency of CO2 emission to keep the oxygen supply adequate to face the energetic demand of the routine level of activity of the workers, when passing from normoxia (air) to hypoxia (in nest galleries).

Growth Control of Microbial in Miscible Cutting Fluids Using Ultraviolet Radiation

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)