Fases da germinação de sementes de Annona emarginata (Schltdl.) H. Rainer em diferentes temperaturas

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Astylus variegatus (Coleoptera, Melyridae): Cytogenetic study of a population exposed to agrochemical products

In this work we describe the cytogenetic analyses performed in specimens of Astylus variegatus (Germar, 1824) collected in two localities: one area of natural vegetation and one of agricultural crops, where agrochemical products were used. Astylus variegatus had karyotypes with 2n(male) = 16+Xy p and 2n (female) = 16+XXp, with exclusively metacentric chromosomes. Pachytene spermatocytes showed synapsed autosomal bivalents and non-associated sex chromosomes. In diplotene, the autosomal bivalents exhibited one or two terminal chiasmata and the Xy p had a typical parachute configuration. In meiotic cells of some specimens, an extra chromosome, interpreted as a B chromosome, was observed. C-banding showed constitutive heterochromatin in the pericentromeric region of all chromosomes, with the exception of the y p. Silver nitrate staining revealed one nucleolus organizer region (NOR) on the terminal region of the short arm of the second autosome pair. Silver staining of meiotic cells confirmed the NOR pattern detected in mitotic cells and revealed an argentophilous material on the Xy p. A cytogenetic comparison between the two populations of A. variegatus showed a statistically significant divergence (chi2 = 117.10; df = 1) in the number of aneuploid cells and a higher frequency of B chromosome in the population exposed to agrochemicals.

Morphogenetic and tillering dynamics in Tanzania grass fertilized and non-fertilized with nitrogen according to season

The objectives of this study were to evaluate morphogenetic characteristics and tillering dynamics in Tanzania grass fertilized and non-fertilized with nitrogen, under intermittent grazing, in the spring and the summer. The main plots were composed of four nitrogen rates (0, 100, 200 and 300 kg/ha) and the subplots were growth seasons: spring (October, November and December) and summer (January, February and March). The experimental design was of randomized block with plots subdivided by time (seasons of the year) and four replications. Urea was used as nitrogen supply and was divided into two applications: one in the spring and another in the summer. The experimental units fertilized with N rates of 200 and 300 kg/ha showed six cycles of pasture, with an average of 27 days of pasture interval, while the treatments with no fertilization and 100 kg/ha of N showed only four and five cycles of pasture, respectively. Leaf elongation rate (LER) and the leaf appearance rate (LAR) increased linearly with increasing of N rates. The greatest population density occurred in summer with the higher nitrogen rates. The treatment without N fertilization showed the lowest growth of tiller population, while the other treatments exhibited growth rates above 50% when compared with non-fertilized samples. Nitrogen rates significantly affect the leaf appearance rate and the leaf elongation rate, as well as the number of live leaves in plants of Tanzania grass in both spring and summer.

Drinking patterns between men and women in two distinct Brazilian communities

OBJETIVO: Realizou-se um inquérito para comparar diferenças de gênero nos padrões de consumo de álcool em duas amostras urbanas, estratificadas e representativas de duas comunidades (B e RJr). MÉTODO: O questionário Genacis (Gênero, Álcool e Cultura: Um Estudo Internacional Gender, Alcohol, and Culture: An Internacional Study) foi utilizado. RESULTADOS: Houve várias diferenças significativas em dados sociodemográficos e de padrões de uso de álcool entre essas duas amostras. Uma delas tinha população mais velha, educada, católica, branca e mais mulheres na força de trabalho. Dados da comunidade B mostraram que mulheres e homens tiveram padrões similares de consumo de álcool. RJr teve uso de álcool mais alto entre homens e 22% dos homens abaixo de 49 anos de idade tinham padrão de uso do tipo binge. DISCUSSÃO: O acesso, tabagismo, renda e ter um parceiro com consumo pesado de álcool foram fatores de risco importantes para o consumo das mulheres. CONCLUSÕES: Este estudo mostra que quando os papéis das mulheres se tornam similares aos dos homens, modificam seu padrão de consumo de álcool.

A MODEL OF THE DEUTERON BASED ON A BREIT TYPE EQUATION

A relativistic treatment of the deuteron and its observables based on a two-body Dirac (Breit) equation, with phenomenological interactions, associated to one-boson exchanges with cutoff masses, is presented. The 16-component wave function for the deuteron (J(pi) = 1+) solution contains four independent radial functions which obey a system of four coupled differential equations of first order. This radial system is numerically integrated, from infinity to the origin, by fixing the value of the deuteron binding energy and using appropriate boundary conditions at infinity. Specific examples of mixtures containing scalar, pseudoscalar and vector like terms are discussed in some detail and several observables of the deuteron are calculated. Our treatment differs from more conventional ones in that nonrelativistic reductions of the order c-2 are not used.

Effect of surface conditioning methods on the microtensile bond strength of resin composite to composite after aging conditions

Objectives. This study evaluated the effect of two different surface conditioning methods on the repair bond strength of a bis-GMA-adduct/bis-EMA/TEGDMA based resin composite after three aging conditions.Methods. Thirty-six composite resin blocks (Esthet X, Dentsply) were prepared (5 mm x 6 mm x 6 mm) and randomly assigned into three groups for aging process: (a) immersion in citric acid (pH 3.0 at 37 degrees C, 1 week) (CA); (b) boiling in water for 8h (BW) and (c) thermocycling (x5000, 5-55 degrees C, dwell time: 30s) (TC). After aging, the blocks were assigned to one of the following surface conditioning methods: (1) silica coating (30 mu m SiOx) (CoJet, 3M ESPE) + silane (ESPE-Sil) (CJ), (2) phosphoric acid + adhesive resin (Single Bond, 3M ESPE) (PA). Resin composite (Esthet.X (R)) was bonded to the conditioned substrates incrementally and light polymerized. The experimental groups formed were as follows: Gr1:CA + PA; Gr2:CA + CJ Gr3:BW + PA; Gr4: BW + CJ; Gr5:TC + PA; Gr6: TC + CJ. The specimens were sectioned in two axes (x and y) with a diamond disc under coolant irrigation in order to obtain non-trimmed bar specimens (sticks, 10 mm x 1 mm x 1 mm) with 1 mm(2) of bonding area. The microtensile test was accomplished in a universal testing machine (crosshead speed: 0.5 mm min(-1)).Results. The means and standard deviations of bond strength (MPa +/- S.D.) per group were as follows: Gr1: 25.5 +/- 10.3; Gr2: 46.3 +/- 10.1; Gr3: 21.7 +/- 7.1; Gr4: 52.3 +/- 15.1; GrS: 16.1 +/- 5.1; Gr6, 49.6 +/- 13.5. The silica coated groups showed significantly higher mean bond values after all three aging conditions (p < 0.0001) (two-way ANOVA and Tukey tests, alpha = 0.05). The interaction effect revealed significant influence of TC aging on both silica coated and acid etched groups compared to the other aging methods (p < 0.032). Citric acid was the least aggressive aging medium.Significance. Chairside silica coating and silanization provided higher resin-resin bond strength values compared to acid etching with phosphoric acid followed by adhesive resin applications. Thermocycling the composite substrates resulted in the lowest repair bond strength compared to citric acid challenge or boiling in water. (C) 2006 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Periosteum-Derived Cells as an Alternative to Bone Marrow Cells for Bone Tissue Engineering Around Dental Implants. A Histomorphometric Study in Beagle Dogs

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

Estimates of covariance functions for growth of Nelore cattle applying a parametric correlation structure to model within-animal correlations

A total of 20,065 weights recorded on 3016 Nelore animals were used to estimate covariance functions for growth from birth to 630 days of age, assuming a parametric correlation structure to model within-animal correlations. The model of analysis included fixed effects of contemporary groups and age of dam as quadratic covariable. Mean trends were taken into account by a cubic regression on orthogonal polynomials of animal age. Genetic effects of the animal and its dam and maternal permanent environmental effects were modelled by random regressions on Legendre polynomials of age at recording. Changes in direct permanent environmental effect variances were modelled by a polynomial variance function, together with a parametric correlation function to account for correlations between ages. Stationary and nonstationary models were used to model within-animal correlations between different ages. Residual variances were considered homogeneous or heterogeneous, with changes modelled by a step or polynomial function of age at recording. Based on Bayesian information criterion, a model with a cubic variance function combined with a nonstationary correlation function for permanent environmental effects, with 49 parameters to be estimated, fitted best. Modelling within-animal correlations through a parametric correlation structure can describe the variation pattern adequately. Moreover, the number of parameters to be estimated can be decreased substantially compared to a model fitting random regression on Legendre polynomial of age. © 2004 Elsevier B.V. All rights reserved.

Bond strength of a resin cement to high-alumina and zirconia-reinforced ceramics: The effect of surface conditioning

Purpose: The aim of this study was to evaluate the effect of two surface conditioning methods on the microtensile bond strength of a resin cement to three high-strength core ceramics: high alumina-based (In-Ceram Alumina, Procera AllCeram) and zirconia-reinforced alumina-based (In-Ceram Zirconia) ceramics. Materials and Methods: Ten blocks (5 ×6 × 8 mm) of In-Ceram Alumina (AL), In-Ceram Zirconia (ZR), and Procera (PR) ceramics were fabricated according to each manufacturer's instructions and duplicated in composite. The specimens were assigned to one of the two following treatment conditions: (1) airborne particle abrasion with 110-μm Al2O3 particles + silanization, (2) silica coating with 30 μm SiOx particles (CoJet, 3M ESPE) + silanization. Each ceramic block was duplicated in composite resin (W3D-Master, Wilcos, Petrópolis, RJ, Brazil) using a mold made out of silicon impression material. Composite resin layers were incrementally condensed into the mold to fill up the mold and each layer was light polymerized for 40 s. The composite blocks were bonded to the surface-conditioned ceramic blocks using a resin cement system (Panavia F, Kuraray, Okayama, Japan). One composite resin block was fabricated for each ceramic block. The ceramic-composite was stored at 37°C in distilled water for 7 days prior to bond tests. The blocks were cut under water cooling to produce bar specimens (n = 30) with a bonding area of approximately 0.6 mm2. The bond strength tests were performed in a universal testing machine (crosshead speed: 1 mm/min). Bond strength values were statistically analyzed using two-way ANOVA and Tukey's test (≤ 0.05). Results: Silica coating with silanization increased the bond strength significantly for all three high-strength ceramics (18.5 to 31.2 MPa) compared to that of airborne particle abrasion with 110-μm Al2O3 (12.7-17.3 MPa) (ANOVA, p < 0.05). PR exhibited the lowest bond strengths after both Al2O3 and silica coating (12.7 and 18.5 MPa, respectively). Conclusion: Conditioning the high-strength ceramic surfaces with silica coating and silanization provided higher bond strengths of the resin cement than with airborne particle abrasion with 110-μm Al2O3 and silanization.

A comparative study of health care policy in the United States and Canada: what policymakers in Latin America might and might not learn from their neighbors to the North

Includes bibliography

Recent advances in brain physiology and cognitive processing

The discovery of participation of astrocytes as active elements in glutamatergic tripartite synapses (composed by functional units of two neurons and one astrocyte) has led to the construction of models of cognitive functioning in the human brain, focusing on associative learning, sensory integration, conscious processing and memory formation/retrieval. We have modelled human cognitive functions by means of an ensemble of functional units (tripartite synapses) connected by gap junctions that link distributed astrocytes, allowing the formation of intra- and intercellular calcium waves that putatively mediate large-scale cognitive information processing. The model contains a diagram of molecular mechanisms present in tripartite synapses and contributes to explain the physiological bases of cognitive functions. It can be potentially expanded to explain emotional functions and psychiatric phenomena. © MSM 2011.

Liouville's theorem and power series for quaternionic functions

In recent years quaternionic functions have been an intense and prosperous object of research, and important results were determined [1]-[6]. Some of these results are similar to well known cases in one complex variable, op. cit. [5], [6]. In this paper the hypercomplex expansion of a function in a power series as well as determination of a Liouville's type theorem have been investigated to the quaternionic functions. In this case, it is observed that the Liouville's type theorem is true for second order derivatives, which differs from its classical version. © 2011 Academic Publications, Ltd.

Use of cooled bull semen as a strategy to increase the pregnancy rate in fixed-time artificial insemination programs-case report

Semen cryopreservation is still considered suboptimal due to lower fertility when compared to fresh semen. The reasons for the loss of fertility are various and related to irreversible damage caused to the cells during the freeze-thaw process. An alternative to conventional cryopreservation represents the use of chilled bull semen, preventing the damage associated with freezing, thereby guaranteeing greater sperm viability. The aim of this study was to describe the use of cooled bull semen as a strategy to increase the pregnancy for Fixed-Time Artificial Insemination (FTAI) of Nellore (Bos indicus) cows. One ejaculate of a select Nellore bull obtained by electroejaculation was used; the semen sample was fractioned into two aliquots: one diluted in Botu-Bov® extender containing 6.4% glycerol for cryopreservation (BB-F, frozen group) and one diluted in the same extender, free from cryoprotectants and used for cooling (BB-C, cooled semen group). The samples in the BB-C group were chilled to 5°C using an isothermic box and maintained for 24 h prior to use. A total of 349 lactating Nellore cows (70-90 days after birth) were synchronized by the insertion of a progesterone releasing device (1.0 g) and estradiol benzoate (2.0 mg i.m.) on a random day of the estrous cycle (Day 0); FTAI was performed 44-48 h after the removal of the device. The pregnancy rates were 45.71 and 61.49% (P<0.05), respectively, for the cryopreserved or chilled bovine semen groups. In conclusion, the use of bull semen cooled for 24 h represents an alternative to conventionally cryopreserved semen, as determined by the increase the pregnancy per artificial insemination in bovine herds. © 2012 Science Publication.

A Comparative Genotoxicity Study of a Supraphysiological Dose of Triiodothyronine (T3) in Obese Rats Subjected to Either Calorie-Restricted Diet or Hyperthyroidism

This study was designed to determine the genotoxicity of a supraphysiological dose of triiodothyronine (T3) in both obese and calorie-restricted obese animals. Fifty male Wistar rats were randomly assigned to one of the two following groups: control (C; n = 10) and obese (OB; n = 40). The C group received standard food, whereas the OB group was fed a hypercaloric diet for 20 weeks. After this period, half of the OB animals (n = 20) were subjected to a 25%-calorie restriction of standard diet for 8 weeks forming thus a new group (OR), whereas the remaining OB animals were kept on the initial hypercaloric diet. During the following two weeks, 10 OR animals continued on the calorie restriction diet, whereas the remaining 10 rats of this group formed a new group (ORS) given a supraphysiological dose of T3 (25 μg/100 g body weight) along with the calorie restriction diet. Similarly, the remaining OB animals were divided into two groups, one that continued on the hypercaloric diet (OB, n = 10), and one that received the supraphysiological dose of T3 (25 μg/100 g body weight) along with the hypercaloric diet (OS, n = 10) for two weeks. The OB group showed weight gain, increased adiposity, insulin resistance, increased leptin levels and genotoxicity; T3 administration in OS animals led to an increase in genotoxicity and oxidative stress when compared with the OB group. The OR group showed weight loss and normalized levels of adiposity, insulin resistance, serum leptin and genotoxicity, thus having features similar to those of the C group. On the other hand, the ORS group, compared to OR animals, showed higher genotoxicity. Our results indicate that regardless of diet, a supraphysiological dose of T3 causes genotoxicity and potentiates oxidative stress. © 2013 de Sibio et al.

Characterization of esterase patterns in hepatopancreas of three species of Macrobrachium (Palaemonidae)

The genus Macrobrachium (Bate, 1868) belongs to the Palaemonidae family. These species are commonly found in lakes, floodplains and rivers in tropical and subtropical regions of South America. The Macrobrachium genus encompasses nearly 210 species of ecological and economic importance. In this study, three species of Macrobrachium (M acrobrachium jelskii, M acrobrachium amazonicum and M acrobrachium brasiliense) were studied in order to characterize the esterase patterns in the hepatopancreas, which were still unknown. Esterases are enzymes which catalyze the hydrolysis of esters. In the hepatopancreas, these enzymes play important roles in several metabolic processes involved in some functions of this organ, such as detoxification and digestion. Twelve esterase bands (EST1 to EST12) were detected in these species, and a comparison among them showed no qualitative differences in interspecific bands, or between males and females. Inhibitors were used to classify the esterase bands. The results indicated seven acetylesterases, two carboxylesterases, one arylesterase, and one cholinesterase. The EST11 band was not detected in these procedures because of its lower frequency. Statistical analyses showed no variability among the species, in either interspecific or intraspecific assays. These results support the hypothesis of a high evolutionary conservation of esterases in the hepatopancreas of these crustaceans. The data enabled us to assess the genetic structure of these species through the use of esterasic enzymes. It also contributes to our knowledge about the biology of these poorly studied species. Knowledge on the genetic structure of populations and species are essential when defining priorities for their management and conservation. © 2012 Elsevier Ltd.