Morphological modifications induced by an artificial diet on the hypopharyngeal glands of Apis mellifera (Hymenoptera, apidae) during their degenerative process

The morphological aspects of the hypopharyngeal glands were analyzed in worker bees of Apis mellifera of 15 and 30 days of age. The individuals were kept in a room with controlled temperature at 32degreesC where they received water and either a protein or a high energy food. Nurse and foraging workers were used as a control for the experiment. The morphological results showed that the different diets modified the cell death characteristics and intensified its occurrence. Both diets caused precocious glandular degeneration. However, this anticipation of cell death was more pronounced in the glandular tissue of the workers who received the high energy diet when compared to the glands of the bees fed with the protein meal.The degenerative signs observed were an intense cytoplasmic vacuolization, with a loss of cytoplasm and of the cell boundaries, dilation or condensation of the cells and nuclei, and nuclear fragmentation. At the end of the degenerative process, we observed the extrusion of nuclei and, finally, the dissolution of the glands. The hypopharyngeal glands' remains were found in the haemolymph.

The germination of seeds of Epiphyllum phyllanthus (L.) Haw. (Cactaceae) is controlled by phytochrome and by nonphytochrome related process

As sementes de Epiphyllum phyllanthus apresentam alta sensibilidade à luz e a sua germinação pode ser promovida pela luz verde de segurança por meio da resposta de fluência muito baixa mediada pelo fitocromo A. Parte da população de sementes tem fitocromo B na forma ativa (Fve) suficiente para promover a germinação no escuro. Sementes de Epiphyllum phyllanthus germinam em uma ampla faixa de temperatura de 10 a 40°C, atingindo germinação completa na faixa de 15 a 30°C. Acima de 35°C a velocidade de germinação aumenta indicando o controle por um processo não relacionado com o fitocromo. A análise da cinética da germinação de sementes indicou que o controle pelo fitocromo A é menos dependente da temperatura do que o processo controlado pelo fitocromo B.

Measurement of the relative branching ratio of B-s(0) -> J/psi f(0)(980) to B-s(0) -> J/psi phi

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Effect of broiler chicken age on ileal digestibility of corn germ meal

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Influence of age on the behavior of dental pulp of dog teeth after capping with an adhesive system or calcium hydroxide

This study evaluated histomorphologically the influence of chronological age of the dog on the dental pulp-healing process after capping with the All Bond 2 system or with calcium hydroxide paste. The animals were divided according to age into young and adult groups. Class 5-type cavities were prepared, and the pulp was submitted to an exposure of a diameter of 0.5 mm. The pulp of the teeth was then protected with the adhesive system or with a calcium hydroxide paste. Sixty days after treatment, the results obtained with the adhesive system in the young group were significantly better than those in the adult group. With calcium hydroxide, the results were similar for both groups. The pulp treated with calcium hydroxide exhibited a complete hard tissue bridge and a pulp without inflammatory reaction, a fact not observed when the adhesive system was used. In conclusion, the chronological age of the pulp influenced the comparative results only for the adhesive system (P = 0.1), and the total results were better with calcium hydroxide than with the All Bond 2 system (P = 0.01).

CHEMICAL SYMPATHECTOMY BLOCKS ANDROGEN BIOSYNTHESIS DURING PREPUBERTY

Twenty-one-day old male Wistar rats were injected subcutaneously with guanethidine (GUA) at doses of 5 and 10 mg kg(-1) day(-1) for 20 days. Animals were sacrificed by decapitation during the prepubertal (41 days of age) and early-pubertal (51 days of age) periods of sexual development. The testes were collected, frozen in liquid N-2 and stored at -70 degrees C until determination of testicular progesterone (P): androstenedione (A) and testosterone (T). Higher levels of P (2.18 +/- 0.24 ng/g. control = 1.24 +/- 0.16 ng/g) associated with decreased levels of androgens (A = 0.26 +/- 0.06 ng/g and T = 2.05 +/- 0.19 ng/g; control = 1.86 +/- 0.76 ng/g and 8.48 +/- 1.16 ng/g, respectively) were observed in 10 mg GUA-treated rats of prepubertal age, while only P levels (3.12 +/- 0.51 ng/g control = 1.73 +/- 0.27 ng/g) were increased in rats of early pubertal age. It is important to note that in 41-day old male rats both 5 and 10 mg were effective in decreasing testicular concentration of testosterone. These results suggest that the sympathetic innervation of the testis is involved in the modulation of androgen biosynthesis, acting through a selective step in the steroid biochemical pathway during the pubertal process and that under the conditions employed the blockage in androgen biosynthesis in the prepubertal stage of sexual maturation is dependent on the dose of GUA.

AGE-RELATED-CHANGES OF GLUTATHIONE CONTENT, GLUTATHIONE-REDUCTASE AND GLUTATHIONE-PEROXIDASE ACTIVITY OF HUMAN ERYTHROCYTES

1. In order to investigate the effect of aging on the erythrocyte glutathione system, total glutathione (GSH), glutathione reductase (GSH-red) and glutathione peroxidase (GSH-px) levels were measured in erythrocytes from 33 young (mean age = 30.5 +/- 9.7 years) and 28 aged (mean age = 68.9 +/- 11.4 years) healthy individuals.2. GSH was 3.5 +/- 1.8-mu-M/g Hb for the young group, a value significantly greater (P < 0.01) than 2.3 +/- 0.9-mu-M/g Hb found for the aged group. Similarly, GSH-red activity, 5.5 +/- 1.8 IU/g Hb, was higher (P < 0.05) for the young group than 3.4 +/- 0.9 IU/g Hb found for the aged group. The GSH-px activity levels for the young group, 21.1 +/- 5.9 IU/g Hb, were significantly greater (P < 0.01) than 12.0 +/- 3.3 IU/g Hb for the aged group. The lower activity detected in the aged group for all of these parameters of the glutathione redox system was not related to low levels of hematocrit or hemoglobin.3. There was no statistical difference in the activation coefficient (AC) of reductase (+FAD/-FAD) between groups, which seems to indicate that the lower activity of glutathione reductase observed in the aged group was not due to riboflavin deficiency.4. Additional information is required to determine the mechanisms controlling the glutathione redox system and its role in the aging process.

Heme-Dependent and Independent Soluble Guanylate Cyclase Activators and Vasodilation

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

Double optical monitoring of time-dependent film formation

A brief overview of optical monitoring for vacuum and wet bench film deposition processes is presented. Interferometric and polarimetric measurements are combined with regard to simultaneous real-time monitoring of refractive index and physical thickness. Monitor stability and accuracy are verified with transparent oil standards. This double optical technique is applied to dip coating with a multi-component Zirconyl Chloride aqueous solution, whose time varying refractive index and physical thickness curves indicate significant sensitivity to changes of film flow properties during the process.

An alternative procedure to decrease the dimension of the frequency dependent modal transformation matrices: Application in three-phase transmission lines with a vertical symmetry plane

The objective of this paper is to show an alternative representation in time domain of a non-transposed three-phase transmission line decomposed in its exact modes by using two transformation matrices. The first matrix is Clarke's matrix that is real, frequency independent, easily represented in computational transient programs (EMTP) and separates the line into Quasi-modes α, β and zero. After that, Quasi-modes α and zero are decomposed into their exact modes by using a modal transformation matrix whose elements can be synthesized in time domain through standard curve-fitting techniques. The main advantage of this alternative representation is to reduce the processing time because a frequency dependent modal transformation matrix of a three-phase line has nine elements to be represented in time domain while a modal transformation matrix of a two-phase line has only four elements. This paper shows modal decomposition process and eigenvectors of a non-transposed three-phase line with a vertical symmetry plane whose nominal voltage is 440 kV and line length is 500 km. © 2006 IEEE.

Using state-space techniques to represent frequency dependent single-phase lines directly in time domain

This paper proposes to use a state-space technique to represent a frequency dependent line for simulating electromagnetic transients directly in time domain. The distributed nature of the line is represented by a multiple 1t section network made up of the lumped parameters and the frequency dependence of the per unit longitudinal parameters is matched by using a rational function. The rational function is represented by its equivalent circuit with passive elements. This passive circuit is then inserted in each 1t circuit of the cascade that represents the line. Because the system is very sparse, it is possible to use a sparsity technique to store only nonzero elements of this matrix for saving space and running time. The model was used to simulate the energization process of a 10 km length single-phase line. ©2008 IEEE.

Savings, investment and growth in the global age: analytical and policy issues

Includes bibliography

Cooperative RNA Polymerase Molecules Behavior on a Stochastic Sequence-Dependent Model for Transcription Elongation

The transcription process is crucial to life and the enzyme RNA polymerase (RNAP) is the major component of the transcription machinery. The development of single-molecule techniques, such as magnetic and optical tweezers, atomic-force microscopy and single-molecule fluorescence, increased our understanding of the transcription process and complements traditional biochemical studies. Based on these studies, theoretical models have been proposed to explain and predict the kinetics of the RNAP during the polymerization, highlighting the results achieved by models based on the thermodynamic stability of the transcription elongation complex. However, experiments showed that if more than one RNAP initiates from the same promoter, the transcription behavior slightly changes and new phenomenona are observed. We proposed and implemented a theoretical model that considers collisions between RNAPs and predicts their cooperative behavior during multi-round transcription generalizing the Bai et al. stochastic sequence-dependent model. In our approach, collisions between elongating enzymes modify their transcription rate values. We performed the simulations in Mathematica® and compared the results of the single and the multiple-molecule transcription with experimental results and other theoretical models. Our multi-round approach can recover several expected behaviors, showing that the transcription process for the studied sequences can be accelerated up to 48% when collisions are allowed: the dwell times on pause sites are reduced as well as the distance that the RNAPs backtracked from backtracking sites. © 2013 Costa et al.

Characterization of the variable cow's age at last calving as a measurement of longevity by using the Kaplan-Meier estimator and the Cox model

In most studies on beef cattle longevity, only the cows reaching a given number of calvings by a specific age are considered in the analyses. With the aim of evaluating all cows with productive life in herds, taking into consideration the different forms of management on each farm, it was proposed to measure cow longevity from age at last calving (ALC), that is, the most recent calving registered in the files. The objective was to characterize this trait in order to study the longevity of Nellore cattle, using the Kaplan-Meier estimators and the Cox model. The covariables and class effects considered in the models were age at first calving (AFC), year and season of birth of the cow and farm. The variable studied (ALC) was classified as presenting complete information (uncensored = 1) or incomplete information (censored = 0), using the criterion of the difference between the date of each cow's last calving and the date of the latest calving at each farm. If this difference was >36 months, the cow was considered to have failed. If not, this cow was censored, thus indicating that future calving remained possible for this cow. The records of 11 791 animals from 22 farms within the Nellore Breed Genetic Improvement Program ('Nellore Brazil') were used. In the estimation process using the Kaplan-Meier model, the variable of AFC was classified into three age groups. In individual analyses, the log-rank test and the Wilcoxon test in the Kaplan-Meier model showed that all covariables and class effects had significant effects (P < 0.05) on ALC. In the analysis considering all covariables and class effects, using the Wald test in the Cox model, only the season of birth of the cow was not significant for ALC (P > 0.05). This analysis indicated that each month added to AFC diminished the risk of the cow's failure in the herd by 2%. Nonetheless, this does not imply that animals with younger AFC had less profitability. Cows with greater numbers of calvings were more precocious than those with fewer calvings. Copyright © The Animal Consortium 2012.

Deposition and photo-induced electrical resistivity of dip-coated NiO thin films from a precipitation process

Thin films of the semiconductor NiO are deposited using a straightforward combination of simple and versatile techniques: the co-precipitation in aqueous media along with the dip- coating process. The obtained material is characterized by gravimetric/differential thermal analysis (TG-DTA) and X-ray diffraction technique. TG curve shows 30 % of total mass loss, whereas DTA indicates the formation of the NiO phase about 578 K (305 C). X-ray diffraction (XRD) data confirms the FCC crystalline phase of NiO, whose crystallinity increases with thermal annealing temperature. UV-Vis optical absorption measurements are carried out for films deposited on quartz substrate in order to avoid the masking of bandgap evaluation by substrate spectra overlapping. The evaluated bandgap is about 3.0 eV. Current-voltage (I-V) curves measured for different temperatures as well as the temperature-dependent resistivity data show typical semiconductor behavior with the resistivity increasing with the decreasing of temperature. The Arrhenius plot reveals a level 233 meV above the conduction band top, which was attributed to Ni2+ vacancy level, responsible for the p-type electrical nature of NiO, even in undoped samples. Light irradiation on the films leads to a remarkable behavior, because above bandgap light induced a resistivity increase, despite the electron-hole generation. This performance was associated with excitation of the Ni 2+ vacancy level, due to the proximity between energy levels. © 2012 Springer Science+Business Media New York.