RNA reallocation during initial spermatic meiosis of Pseudonannolene tocaiensis Fontanetti, 1996

Toluidine Blue dye containing increasing concentrations of Mg2+ or Ca2+ can show loss of metachromacy at a certain concentration of the inorganic cation when staining DNA-protein complexes in vitro and in vivo. This process has been named Critical Electrolyte Concentration (CEC) and is applied to the study of protein-nucleic acid complexes at different stages of chromatin supra-organization. Male gametocytes of the species Pseudonannolene tocaiensis were studied, observing a large amount of ribonucleoproteins in the gametocytes cytoplasm throughout prophase I. The nucleolus is maintained during most of the prophase. The highly condensed region showing the bouquet formation appeared stained with the typical tonality for chromatin; this region corresponds to the constitutive heterochromatin. We also observed the presence of RNA all through the chromosomes in prophase I. The permanence of this material surrounding the chromosomes during male meiosis is difficult to explain, since a great reduction of the products of spermatogenesis occurs due to the fact that most of the material of the spermatozoids is not used during fecundation. However, in P. tocaiensis this material is remains even at the spermatids. It is known that during the spermiogenesis of certain insects, RNA synthesis continues at the spermatid, being subsequently eliminated from the nucleus and then from the cell due to the elongation of the nucleus. Therefore, we could suggest that permanence of this material (RNA) during meiosis has a function in the process of cell division.

Initial concentration profile influence on migration measurements from plastic packaging: A simulation study

Migration of components from plastic packaging into foodstuffs or into medicines is a very important issue, concerning public health. Using experimental techniques, like gas chromatography-mass spectrometry, these essays measure total migration and specific migration of components from plastic packaging. This work presents an explanation and applications of a numerical technique tool for this measurement, allowing the comprehension of the diffusion process and the estimate of component migration in difficult or impractical measurements. As an application example, the non-uniform influence of initial concentration profile on the migration is presented, demonstrating the necessity of this profile determination for high quality considerations on involved metrology.

Abordagem initial do paciente com mielopatia aguda não compressiva

Acute myelopathy are characterized by spinal cord dysfunction, developing sensitive, motor and autonomic signs and symptons. Since they are relatively rare, there are some difficulties to early diagnosis and to the beginning of the treatment. So, literature was reviewed to describe the main aetiologies of acute non compressive myelopathy: 1) demyelinating diseases; 2) systemic disease; 3) parainfectious; 4) delayed radiation myelopathy; 5) vascular myelopathy; 6) idiopatic and 7) vitamin B12 deficiency. Besides, we suggest an algorithm to initial approach of these patients and further aethiologic investigation. © Copyright Morelra Jr. Editora.

Hindlimb unloading producing effects on bone biomechanical properties in mature male rats

Aging is associated with decline in muscle mass and strength and reduced bone density. Age-related bone loss is a primary factor in osteoporosis and all individuals are potential candidates for osteoporosis because bone loss with aging occurs in men and women, but less studied in men. To examine the appropriateness of hindlimb elevation, by tail suspension as a model for diminished mechanical loading, and to determine the influence of age on bone responsiveness to skeletal unloading, we use dual X ray absorptiometry (DXA) and digital radiographic images to analyze the response of the femur from mature rats to biomechanical loads. Femurs from male Wistar rats (9-mo-old) were scanned using DXA and DIGORA and measures obtained in ephipyseal and diaphyseal regions of interest. The mechanical testing was divided into compression load to fracture the head and a three-point bending load to fracture the femur middiaphysis. In femoral epiphysis from hindlimb unload (HU), animals presented significant differences between mineral bone content and density assessed by DXA. Detailed regions of femoral epiphysis (head, throcanteric fossa, throcanter and metaphysis) presented significant lower values from radiographic density. Only compressive load necessary to fracture the femoral head neck was also significantly diminished in HU animals. Disuse induced, as in elderly patients, deterioration of the trabecular bone architecture with critical effect on bone fragility. Rats with 21 days of hindlimb unloading can simulate disuse, suggesting that certain sub-regions of their aging bones are more susceptible to fracture, while other, i.e. diaphyses, are not.

A 2-D delaunay refinement algorithm using an initial prerefinement from the boundary mesh

An improvement to the quality bidimensional Delaunay mesh generation algorithm, which combines the mesh refinement algorithms strategy of Ruppert and Shewchuk is proposed in this research. The developed technique uses diametral lenses criterion, introduced by L. P. Chew, with the purpose of eliminating the extremely obtuse triangles in the boundary mesh. This method splits the boundary segment and obtains an initial prerefinement, and thus reducing the number of necessary iterations to generate a high quality sequential triangulation. Moreover, it decreases the intensity of the communication and synchronization between subdomains in parallel mesh refinement. © 2008 IEEE.

Effect of the density and of the distance of Brachiaria decumbens staff on the initial growth of Coffea arabica L. Seedligns

The aim of this work was to evaluate the interference of three densities (4, 8 and 16 plants/m 2) of Brachiaria decumbens Stapf distributed at three different distances (0, 10 and 20 cm from coffee plants) on the initial growth of Coffea arabica L. seedlings. Dark red Latosoil was used as substrate to fill up 70 liters cement boxes. Coffee seedlings at 15 cm height and 8 leaves stage were planted in each box. B. decumbens seedlings were transplanted when they reached two to four leaves stage. The experimental design was a randomized blocks with ten treatments and three replications. At the end of the experiment were measured, height, leaf number, leaf area, chlorophyll content and dry weight of coffee plants. Dry weight of B. decumbens leaves was also evaluated. The leaf area and leaf dry weight was shown to be more sensitive parameters to the interference of Brachiaria plants. Dry weight of coffee plants were reduced from 60% to 88% when the B. decumbens were transplanted 0 cm from the coffee plant. With distance of 10 cm the reduction of dry weight increased with the increase of the density of the B. decumbens. In the coexistence of the coffee plants with 16 plants/m 2 of B. decumbens, there was a reduction in the dry weight of about 80% at the distances of 0 and 20 cm. Regarding leaf area, the reduction was 47% on the average in the density of 4 plants/m 2 of B. decumbens The reduction in leaf area at other densities was higher at the distance of 0 and 20 cm, and 55% reduction was obtained at the distance of 10 cm.

Bone structure, strength and microhardness resulting after hindlimb unloading in rats

Introduction: Bone strength is influenced by a number of different determinants, such as mass, size, geometry and also by the intrinsic material properties of the tissue. Aims: The structure and mechanical properties of the femur were analyzed in aged (14 mo-old) animals submitted to hindlimb unloading (HU) for 21 days. Methods: Twenty Wistar rats were randomly divided into Control and HU groups and the femur was submitted to dual X ray absorptiometry (DXA), DIGORA radiographic density, mechanical compression testing and Knoop microhardness analyse in cortical and cancellous bone. Results: Femurs from HU group presented significantly lower failure load, decreased bone mineral density (BMD)/bone mineral content (BMC) in whole bone; proximal/distal epiphysis and middiaphyseal cortical bone measured by DXA were similar in the two groups; radiographic density from areas in proximal epiphysis was significantly lower in HU group, and microhardness measured at periosteal and endosteal levels were also signifcantly diminished in HU compared with Control group. Conclusion: Disuse induced damage in the trabecular femoral bone architecture with decisive effect on the head and trochanteric fossa, which became weaker. Bone diaphyseal cortical hardness also suffered effect of unloading, probably related to osteocyte/osteoblast activity.

Aplicação da espirometria durante teste padrão de exercício progressivo em esteira para avaliação da troca gasosa respiratória de equinos da raça árabe

The current study evaluated equine gas exchange responses through spirometry, by measuring oxygen uptake (VO2), carbon dioxide production (VCO2), respiratory exchange ratio (R) and maximum oxygen uptake (VO2max) of Arabian horses during a standard incremental exercise test performed on a high-speed treadmill. Six clinically healthy Arabian horses were submitted to a standard incremental exercise test, performed on a high-speed treadmill at a 6% slope, and initial speed of 1,8 m.s-1 for 5 minutes, then 4,0 m.s-1 for 3 minutes, 6,0 m.s-1 for 2 minutes and 8,0 m.s-1, 9,0 m.s-1, 10,0 m.s-1 and 11,0 m.s-1 for one minute for each of these speed. The end of the exercise test was defined as the point in which the horse was no longer able to keep pace with the treadmill. Gas exchange was measured through respiratory analyses horse mask on the last 10 seconds at the end of each speed transition and at 1, 2 and 3 minutes after the end of the exercise, defined as experiment moments. During exercise, it was noticed an increase on both VO2 and VCO2 with linear relationship between exercise and speed. Arabian horses VO2max was 114,9 mL.kg-1.min-1. The respiratory exchange ratio increased over 1,0 by the speed of 9,0 m.s-1, indicating the preponderance of the anaerobic metabolism, and remains at a high level on the post-exercise period.

SEM-EDS and biomechanical evaluation of implants with different surface treatments: An initial study

Aim: Alterations in implant surfaces can affect periimplant bone formation and shorten the healing time. The goal of the present study was a comparative scanning electron microscopy (SEM)/energy dispersive spectrometry (EDS) and biomechanical evaluation of implants subjected to different surface treatments. Materials and Methods: Four implant surfaces were analyzed in the present study: machined commercial implants (TU); porous-surfaced commercial implants blasted with Al2O3 microspheres and acid-etched (TJA); laser beam-irradiated experimental implants (Laser) and laser beam-irradiated experimental implants with hydroxyapatite coating (HA). One sample for each surface underwent pre-surgery SEM/EDS analysis. Thirty-two implants (8 for each surface treatment) were then inserted into the tibia of 4 rabbits. After 8 weeks, the animals were euthanized and the implants retrieved by reverse torque and processed for post-surgery SEM/EDS analysis. Results: HA implants presented higher removal torque values when compared to Laser, TJA and TU groups. Post-surgery SEM micrographs clearly showed bone formation on all the examined surfaces; however, in the TU group bone covered only some areas of the implant surface, while in TJA, Laser and HA groups the entire implant surfaces were overlaid by newly formed bone. EDS analysis supported the results obtained by SEM and removal torque, showing that concentration of Ca and P increased from TU to TJA, Laser and HA implants. Conclusions: Implants with surfaces modified by laser beam with or without apatite coating showed more promising results.

Automatic segmentation of digital images applied in cardiac medical images

The digital image processing has been applied in several areas, especially where it is necessary use tools for feature extraction and to get patterns of the studied images. In an initial stage, the segmentation is used to separate the image in parts that represents a interest object, that may be used in a specific study. There are several methods that intends to perform such task, but is difficult to find a method that can easily adapt to different type of images, that often are very complex or specific. To resolve this problem, this project aims to presents a adaptable segmentation method, that can be applied to different type of images, providing an better segmentation. The proposed method is based in a model of automatic multilevel thresholding and considers techniques of group histogram quantization, analysis of the histogram slope percentage and calculation of maximum entropy to define the threshold. The technique was applied to segment the cell core and potential rejection of tissue in myocardial images of biopsies from cardiac transplant. The results are significant in comparison with those provided by one of the best known segmentation methods available in the literature. © 2010 IEEE.

Initial analysis from a Lidar observation campaign of sugar cane fires in the central and western portion of the S̃ao Paulo State - Brazil

The central and western portion of the S̃ao Paulo State has large areas of sugar cane plantations, and due to the growing demand for biofuels, the production is increasing every year. During the harvest period some plantation areas are burnt a few hours before the manual cutting, causing significant quantities of biomass burning aerosol to be injected into the atmosphere. During August 2010, a field campaign has been carried out in Ourinhos, situated in the south-western region of S̃ao Paulo State. A 2-channel Raman Lidar system and two meteorological S-Band Doppler Radars are used to indentify and quantify the biomass burning plumes. In addiction, CALIPSO Satellite observations were used to compare the aerosol optical properties detected in that region with those retrieved by Raman Lidar system. Although the campaign yielded 30 days of measurements, this paper will be focusing only one case study, when aerosols released from nearby sugar cane fires were detected by the Lidar system during a CALIPSO overpass. The meteorological radar, installed in Bauru, approximately 110 km northeast from the experimental site, had recorded echoes (dense smoke comprising aerosols) from several fires occurring close to the Raman Lidar system, which also detected an intense load of aerosol in the atmosphere. HYSPLIT model forward trajectories presented a strong indication that both instruments have measured the same air masss parcels, corroborated with the Lidar Ratio values from the 532 nm elastic and 607 nm Raman N2 channel analyses and data retrieved from CALIPSO have indicated the predominance of aerosol from biomass burning sources. © 2011 SPIE.

Restauração florestal visando à conservação de recursos hídricos por meio da combinação linear ponderada

This study evaluated using of Multicriteria Evaluation in a GIS, specifically by Weighted Linear Combination Method for generation of map of priority areas for forest restoration in the initial part of River Pardo Basin, SP, in order to water resources conservation. Aiming to define criteria and restrictions it was used Participatory Techniques, and the following factors had been selected: proximity of the hydrographic network, proximity of forest cover, slope and erodibility of soil. To calculate the weight to each factor it was used the decision-making process, known as Analytic Hierarchy Analysis, this method consists of a paired comparison of factors to determine the relative importance of each. According to Weighted Linear Combination, the very high priority areas have a more limited spatial distribution, with an apparent concentration around the water bodies, outlining a buffer to the river system. The proximity factor of the hydrographic network, and enables the connection forestry, contributed, along with the factor of proximity to forest cover, so there would be the definition of most of the areas with the highest priority in the basin, which concentrate the largest areas of forest and native riparian areas along the hydrographic.

Relationship between citrus productivity and indicators of uniformity in trickle irrigation system

In trickle irrigation systems, the design is based on the pre-established emission uniformity (EU) which is the combined result of the equipment characteristics and its hydraulic configuration. However, this desired value of the EU may not be confirmed by the final project (in field conditions) and neither by the yield uniformity. The hypotheses of this research were: a) the EU of a trickle irrigation system at field conditions is equal to the emission uniformity pre-established in the its design; b) EU has always the lowest value when compared with other indicators of uniformity; c) the discharge variation coefficient (VC) is not equal to production variation coefficient in the operational unit; d) the difference between the discharge variation coefficient and the productivity variation coefficient depends on the water depth applied. This study aimed to evaluate the relationship between EU used in the irrigation system design and the final yield uniformity. The uniformity indicators evaluated were: EU, distribution uniformity (UD) and the index proposed by Barragan & Wu (2005). They were compared estimating the performance of a trickle irrigation system applied in a citrus orchard with dimensions of 400m x 600m. The design of the irrigation system was optimized by a Linear Programming model. The tree rows were leveled in the larger direction and the spacing adopted in the orchard was 7m x 4m. The manifold line was always operating on a slope condition. The sensitivity analysis involved different slopes, 0, 3, 6, 9 and 12%, and different values of emission uniformity, 60, 70, 75, 80, 85, 90 and 94%. The citrus yield uniformity was evaluated by the variation coefficient. The emission uniformity (EU) after design differed from the EU pre-established, more sharply in the initial values lower than 90%. Comparing the uniformity indexes, the EU always generated lower values when compared with the UD and with the index proposed by Barragan. The emitter variation coefficient was always lower than the productivity variation coefficient. To obtain uniformity of production, it is necessary to consider the irrigation system uniformity and mainly the water depth to be applied.

Model to increase the lateral line length of drip irrigation systems

Non-pressure compensating drip hose is widely used for irrigation of vegetables and orchards. One limitation is that the lateral line length must be short to maintain uniformity due to head loss and slope. Any procedure to increase the length is appropriate because it represents low initial cost of the irrigation system. The hypothesis of this research is that it is possible to increase the lateral line length combining two points: using a larger spacing between emitters at the beginning of the lateral line and a smaller one after a certain distance; and allowing a higher pressure variation along the lateral line under an acceptable value of distribution uniformity. To evaluate this hypothesis, a nonlinear programming model (NLP) was developed. The input data are: diameter, roughness coefficient, pressure variation, emitter operational pressure, relationship between emitter discharge and pressure. The output data are: line length, discharge and length of the each section with different spacing between drippers, total discharge in the lateral line, multiple outlet adjustment coefficient, head losses, localized head loss, pressure variation, number of emitters, spacing between emitters, discharge in each emitter, and discharge per linear meter. The mathematical model developed was compared with the lateral line length obtained with the algebraic solution generated by the Darcy-Weisbach equation. The NLP model showed the best results since it generated the greater gain in the lateral line length, maintaining the uniformity and the flow variation under acceptable standards. It had also the lower flow variation, so its adoption is feasible and recommended.

Existence of solutions for the 3D-micropolar fluid system with initial data in Besov-Morrey spaces

In this paper, we show a local-in-time existence result for the 3D micropolar fluid system in the framework of Besov-Morrey spaces. The initial data class is larger than the previous ones and contains strongly singular functions and measures. © 2013 Springer Basel.