Testis morphology and dichotomic spermatogenesis in the sugarcane borer Diatraea saccharalis (F.) (Lepidoptera: Crambidae)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Location, morphology and function of nephrocytes in termites

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Otimização dos parâmetros para obtenção de nanotubos em Ti-Cp por anodização eletroquímica e aplicação na liga experimental Ti-35Nb-7Zr

Pós-graduação em Engenharia Mecânica - FEG

Influence of lineage of oocyte donor on the yield and morphology of oocytes recovered by ultrasound-guided follicular aspiration in nellore cows

The objective of this study was to investigate the influence of lineage of oocytes donors on the number and quality of oocytes obtained through ultrasound-guided follicular aspiration in Nellore breed cows derived from two lineages of bulls (Karvadi; K and Taj-Mahal; T). Both maternal (Km and Tm) and paternal (Kp and Tp) lineages, as well as their combinations were investigated. Oocyte aspirations were repeatedly performed with an aspiration interval of 15 days in 56 donor females. Recovered cumulus oocyte-complexes (COCs) were counted, morphologically examined and classified into seven categories (grades from I to VII) according to the number of layers of the cumulus oocyte and cytoplasm appearance. The mean number of oocytes retrieved from donors of lineage Tp-Tm was significantly higher (28.23±1.92, P<0.05) than those obtained from lineages Kp-Tm, Kp-Km, and Tp-Km (21.34±1.32, 21.28±1.73, and 16.72±1.31, respectively). There was no significant difference in the mean number of recovered oocytes between donors of lineages Kp-Km and Kp-Tm, whereas animals of lineage Tp-Km yielded the lowest number of oocytes. Higher mean number of grade III oocytes was recovered from donors of lineage Kp than lineage Tp (10.11±0.66 versus 8.79±0.58, respectively), with more grade III oocytes being obtained in both lineages as compared to the others. Paternal lineage did not influence the quality of recovered oocytes in any other category, but both Kp and Tp yielded a great mean number of oocytes graded as I, II, and III (3.14±0.21; 4.93±0.33, and 10.11±0.66 versus 3.19±0.21, 5.59±0.44, and 8.79±0.58, respectively) than those classified as IV, V, VI, and VII. However, when considering the data from the maternal lineage significantly more oocytes (P<0.05) of grade I, II and III were obtained from Taj-Mahal (11.67 ± 0.67, 5.9±0.42 and 3.64±0.25, respectively) than for lineage Karvadi, with similar results for oocytes of grades IV, V, VI, and VII. Similarly to the paternal lineage, the number of oocytes of grade III was superior (P<0.05) when compared to other categories for both lineages. In conclusion, we demonstrate here a direct influence of lineage of oocyte donor on the production and quality of oocytes obtained through ultrasound-guided follicular aspiration in Nellore cows.

Relationship between the morphology of the maxillary central incisor and horizontal and vertical measurements of the face

Purpose: In order to assist in the selection of artificial teeth for complete dentures, this study aimed to assess the relationship between horizontal and vertical measurements of the face and the morphology of the maxillary central incisor. Materials and Methods: This was a study of 50 plaster casts and 100 teleradiographs - 50 in lateral norm and 50 in frontal norm, belonging to 50 individuals, Caucasian, with a naturally optimal occlusion, matching at least four of the six keys of Andrews. Images of the upper central incisors were obtained by scanning the plaster casts (three-dimensional) and subjectively classified by three examiners as oval, triangular or quadrangular. Facial measures (vertical and horizontal) were defined by means of teleradiographs. In order to check inter-examiner agreement on the classification of central incisor, the Kappa test was used. To verify whether data had normal distribution, the Kolmogorov-Smirnov test was used ( P > 0.2) was used. One-way analysis of variance was employed to assess the association between variables (P > 0.05). Results: When vertical measurements were compared with the three incisor shapes, there was no statistically significant difference (P > 0.05): Triangular (0.54), oval (0.63) and quadrangular (0.51). Similarly, no difference (P > 0.05) was found for facial width (139.08, 143.37, 141.65), maxillary width (76.68, 78.99, 76.91) and mandibular width (103.47, 105.50, 103.11). Conclusions: The majority of cases showed that horizontal and vertical measurements of the face cannot be used as a reference for determining the morphology of the maxillary central incisor crown. It is relevant to analyze and compare other morphological structures to improve the oral health-related quality of life for the conventional denture wearer.

Morphology and properties of (Ba, Sr, Ca) titanates synthesized by microwave-assisted hydrothermal method

Ba1-xCaxTiO3, Ba1-xSrxTiO3 and Sr1-xCaxTiO3 (x = 0, 0.25, 0.50, 0.75 and 1) nanoparticles were synthesized using the microwave-assisted hydrothermal method. Samples were prepared for 40 minutes at 140°C under a pressure of 3 MPa using an adapted domestic microwave oven. The samples were characterized by X-Ray diffraction (XRD), scanning electron microscopy (FE-SEM), and Raman, photoluminescence (PL) and ultraviolet-visible (UV-Vis) spectroscopies. XRD data show that ceramic powders have crystalline phases associated with a short-range structural disorder. This structural disorder is confirmed by Raman spectral bands indicating multi-phonon processes and the presence of defects or impurities. Such defects account for a broad band in the photoluminescence spectrum in the green light (460 nm) region for all samples. Gap energy variation, obtained from UV-Vis spectra, suggest a non-uniform band structure of these titanates in accordance with the PL results. The morphology of each sample is changed with doping and varies from a spherical to cubic appearance for energy minimization.

Al-doping effect on the surface morphology of zno films grown by reactive rf magnetron sputtering

Zinc oxide (ZnO) and aluminum-doped zinc oxide (ZnO:Al) thin films were deposited onto glass and silicon substrates by RF magnetron sputtering using a zinc-aluminum target. Both films were deposited at a growth rate of 12.5 nm/min to a thickness of around 750 nm. In the visible region, the films exhibit optical transmittances which are greater than 80%. The optical energy gap of ZnO films increased from 3.28 eV to 3.36 eV upon doping with Al. This increase is related to the increase in carrier density from 5.9 × 1018 cm−3 to 2.6 × 1019 cm−3 . The RMS surface roughness of ZnO films grown on glass increased from 14 to 28 nm even with only 0.9% at Al content. XRD analysis revealed that the ZnO films are polycrystalline with preferential growth parallel to the (002) plane, which corresponds to the wurtzite structure of ZnO.

A New Species of Myxidium (Myxosporea: Myxidiidae), from the Western Chorus Frog, Pseudacris triseriata triseriata, and Blanchard's Cricket Frog, Acris crepitans blanchardi (Hylidae), from Eastern Nebraska: Morphology, Phylogeny, and Critical Comments on Amphibian Myxidium Taxonomy

During March 2001-April 2004, 164 adult anurans of 6 species (47 Rana blairi, 35 Rana catesbeiana, 31 Hyla chrysoscelis, 31 Pseudacris triseriata triseriata, 11 Bufo woodhousii, and 9 Acris crepitans blanchardi) from Pawnee Lake, Lancaster County, Nebraska, were surveyed for myxozoan parasites. Of these, 20 of 31 (65%) P. triseriata triseriata and 1 of 9 (11%) A. crepitans blanchardi were infected with a new species of Myxidium. Myxidium melleni n. sp. (Myxosporea) is described from the gallbladder of the western chorus frog, P. triseriata triseriata (Hylidae). This is the second species of Myxidium described from North American amphibians. Mature plasmodia are disc-shaped or elliptical 691 (400-1,375) × 499 (230-1,200) × 23 (16-35) μm, polysporic, producing many disporic pansporoblasts. The mature spores, 12.3 (12.0-13.5) × 7.6 (7.0-9.0) × 6.6 (6.0-8.0) μm, containing a single binucleated sporoplasm, are broadly elliptical, with 2-5 transverse grooves on each valve, and contain two equal polar capsules 5.2 (4.8-5.5) × 4.2 (3.8-4.5) μm positioned at opposite ends of the spore. Myxidium melleni n. sp. is morphologically consistent with other members of Myxidium. However, M. melleni n. sp. was phylogenetically distinct from other Myxidium species for which DNA sequences are available. Only with improved morphological analyses, accompanied by molecular data, and the deposit of type specimens, can the ambiguous nature of Myxidium be resolved. Guidelines for descriptions of new species of Myxidium are provided.

Morphology and Deformation Mechanisms and Tensile Properties of Tetrafunctional Multigraft Copolymers

Morphology and deformation mechanisms and tensile properties of tetrafunctional multigraft (MG) polystrene-g-polyisoprene (PS-g-PI) copolymers were investigated dependent on PS volume fraction and number of branch points. The combination of various methods such as TEM, real time synchrotron SAXS, rheo-optical FTIR, and tensile tests provides comprehensive information at different dimension levels.TEMand SAXS studies revealed that the number of branch points has no obvious influence on the microphase-separated morphology of tetrafunction MG copolymers with 16 wt % PS. But for tetrafunctional MG copolymers with 25 wt % PS, the size and integrity of PS microdomains decrease with increasing number of branch point. The deformation mechanisms ofMGcopolymers are highly related to the morphology. Dependent on the microphase-separated morphology and integrity of the PS phase, the strain-induced orientation of the PS phase is at different size scales. Polarized FT-IR spectra analysis reveals that, for all investigated MG copolymers, the PI phase shows strain-induced orientation along SD at molecular scale. The proportion of the PI block effectively bridging PS domains controls the tensile properties of the MGcopolymers at high strain, while the stress-strain behavior in the low-mediate strain region is controlled by the continuity of PS microdomains. The special molecular architecture, which leads to the higher effective functionality of PS domains and the higher possibility for an individual PI backbone being tethered with a large number of PS domains, is proposed to be the origin of the superelasticity for MG copolymers.

Influence of the deposition parameters on the morphology and electrical conductivity of PANI/PSS self-assembled films

The influence of deposition parameters, namely polymer concentration and pH of the deposition solution, cleaning, and drying steps on the morphology and electrical characteristics of polyaniline and sulfonated polystyrene (PANI/PSS) nanostructured films deposited by the self-assembly technique is evaluated by UV-Vis spectroscopy, optical and atomic force microscopy, and electrical resistance measurements. It is found that stirring the cleaning solution during the cleaning step is crucial for obtaining homogenous films. Stirring of the cleaning solution also influences the amount of PANI adsorbed in the films. In this regard, the drying process seems to be less critical since PANI amount and film thickness are similar in films dried with N-2 flow or with an absorbent tissue. It is observed, however, that drying with N-2 flow results in rougher films. As an additional point, an assessment of the influence of the deposition method (manual versus mechanical) on the film characteristics was carried out. A significant difference on the amount of PANI and film thickness between films prepared by different human operators and by a homemade mechanical device was observed. The variability in film thickness and PANI adsorbed amount is smaller in films mechanically assembled. (c) 2007 Elsevier B.V. All rights reserved.

Influence of a narrow depth gradient and season on the morphology, phenology, and epibiosis of the brown alga Sargassum cymosum

Temporal and spatial fluctuations of environmental parameters are normally assigned as causes of variations in morpho-phenological characters of seaweeds and in their epibionts, but formal tests of such hypotheses are lacking, especially in narrow gradients. The present study evaluated the influence of a very small depth gradient (1 to 3 m) and of subtle seasonality characteristic of tropical areas on morpho-phenological traits and on the occurrence of sessile epiphytic organisms using a controlled orthogonal sampling design in a sublittoral population of the tropical brown alga Sargassum cymosum. Four temporal samples were obtained over a one-year period at three depths using nine replicates. The wet weight, maximum length, number of primary and secondary branches, and proportion of secondary branches with receptacles were recorded. Epibiosis was estimated by visual evaluation of percentage cover on secondary branches. Algal morphology varied as a function of the period of the year (weaker effect) and depth (stronger effect) but in different ways for each variable analysed. In general, fronds tended to be shorter, heavier, and more ramified in shallower areas. In relation to time, the morphological characters tended mostly to present higher values in January (summer) and/or April (autumn). Frequency of receptacles did not depend on algal morphology and depth at all but varied in time, although only in the deepest area. Epibiosis also did not depend on algal morphology but varied in relation to time (stronger effect) and, to a lesser extent, depth (weaker effect). The effect of time upon epibiosis also depended on the biological group analysed. These data support the hypothesis that algal morphology varies in relation to period of the year and depth, even under small temporal and spatial environmenal gradients.

Morphology of the Gas Bladder in Sea Catfishes (Siluriformes: Ariidae)

The morphology of the gas bladder and associated structures in sea catfishes (Siluriformes: Ariidae) is studied. The most simple gas bladder, exclusive to Galeichthys Valenciennes, is apple-shaped with weakly developed internal trabeculae, has smooth walls externally and a short Mullerian window associated with a broad, short Mullerian ramus that is firmly attached to Baudelot`s ligament and supracleithrum. Most genera of Ariidae have a cordiform bladder with well-developed trabeculae, smooth walls externally, an elongate Mullerian window and an elongate Mullerian ramus with an acute tip that is free from the Baudelot`s ligament and supracleithrum. Sciades proops (Valenciennes) and S. parkeri (Traill) have a similar gas bladder but with a well-developed secondary chamber. Other genera of Ariidae also have a cordiform bladder with well-developed trabeculae and elongate Mullerian window, but with lateral diverticula present as shallow rounded bulges or blister-like swellings along the peripheral margins of the bladder. The degree of development of lateral diverticula varies among and within species, with Osteogeneiosus Bleeker having the most highly-developed diverticula. Bagre pinnimaculatus (Steindachner) and Bagre bagre (Linnaeus) have unusual depressed gas bladders with complex network of internal trabeculae. The implications of gas bladder morphology for the taxonomy and phylogenetic relationships of the family are discussed.

Morphology of the gas bladder in thorny catfishes (Siluriformes: Doradidae)

The gross morphology of the gas bladder is described, illustrated, compared and categorized among 86 of 88 nominal valid and six undescribed species representing all 31 genera of Doradidae with comments on ontogenetic and taxonomic variation when observed. The putatively basal-most doradids exhibit an unmodified cordiform gas bladder. Derived taxa exhibit an impressive suite of modifications including the addition of a secondary bladder, pronounced reduction of the posterolateral chambers, internal trabeculae, associations with bony capsule-like expansions of the anterior (Weberian) vertebrae, and accessory diverticula varying widely in size, shape, abundance, and distribution. Intra-specific differences are minor, most often reflective of ontogenetic changes especially in large-size species, whereas inter-specific and inter-generic differences are significant, in many cases diagnostic, and suggestive of phylogenetic signal excepting instances of evident convergence such as gas bladder reduction in Rhynchodoras and all but one species of Leptodoras.

Morphology of the Gas Bladder in Bumblebee Catfishes (Siluriformes, Pseudopimelodidae)

The gross morphology of the gas bladder is described and compared for representatives of all valid genera of Pseudopimelodidae (Siluriformes). Cephalosilurus albomarginatus and species of Batrochoglanis, and Microglanis have the most basic form: a large, cordiform gas bladder with a simple internal T-shaped septum. Cephalosilurus apurensis, C. fowleri, and C. nigricauda also have a large, cordiform gas bladder, but they have well-developed trabeculae associated with the internal T-shaped septum, and a pair of well-developed constrictor muscles inserted on the external wall; the latter feature is present in most species of Pimelodidae, but absent in all other catfishes. The monotypic Lophiosilurus alexandri also has well-developed constrictor muscles, and its gas bladder is moderately sized. The species of Pseudopimelodus and Cruciglanis have a diminutive gas bladder partially divided into two lateral sacs without internal communication, and lack constrictor muscles. The parapophysis of the fourth vertebra is a wide and long shelf connected to the dorsal surface of the gas bladder in most pseudopimelodid genera. However, in the species of Pseudopimelodus and Cruciglanis the parapophysis of the fourth vertebra is shorter and has its anterior ramus folded back, partially covering the gas bladder anteroventrally; and the tympanic opening is smaller than in species of the other genera. Five phylogenetic characters are proposed based on the morphology of the gas bladder and associated structures in species of Pseudopimelodidae, and the evolution of those characters in the family is discussed. J. Morphol. 272:890-896, 2011. (C) 2011 Wiley-Liss, Inc.

Chromatin Structure of Ribosomal RNA Genes in Dipterans and Its Relationship to the Location of Nucleolar Organizers

Nucleoli, nuclear organelles in which ribosomal RNA is synthesized and processed, emerge from nucleolar organizers (NORs) located in distinct chromosomal regions. In polytene nuclei of dipterans, nucleoli of some species can be observed under light microscopy exhibiting distinctive morphology: Drosophila and chironomid species display well-formed nucleoli in contrast to the fragmented and dispersed nucleoli seen in sciarid flies. The available data show no apparent relationship between nucleolar morphology and location of NORs in Diptera. The regulation of rRNA transcription involves controlling both the transcription rate per gene as well as the proportion of rRNA genes adopting a proper chromatin structure for transcription, since active and inactive rRNA gene copies coexist in NORs. Transcription units organized in nucleosomes and those lacking canonical nucleosomes can be analyzed by the method termed psoralen gel retarding assay (PGRA), allowing inferences on the ratio of active to inactive rRNA gene copies. In this work, possible connections between chromosomal location of NORs and proportion of active rRNA genes were studied in Drosophila melanogaster, and in chironomid and sciarid species. The data suggested a link between location of NORs and proportion of active rRNA genes since the copy number showing nucleosomal organization predominates when NORs are located in the pericentric heterochromatin. The results presented in this work are in agreement with previous data on the chromatin structure of rRNA genes from distantly related eukaryotes, as assessed by the PGRA.