941 resultados para Brill, Paulus, 1554-1625.


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Detailed characterizations of the karyotypes of the Brazilian leptodactylid frogs Pleurodema diplolistris, the only species of Pleurodema not studied cytogenetically so far, and Physalaemus nattereri, a species in the Ph. biligonigerus group, are presented. Both karyotypes had 2n = 22 and their chromosomes had a very similar morphology, except for pair 11, which was metacentric in Pl. diplolistris and telocentric in Ph. nattereri. The localization of nucleolar organizer regions (NORs) and heterochromatic bands allowed the differentiation of chromosomes that were morphologically indistinguishable between these species, such as pairs 1, 3 and 10, which showed interstitial C-bands in Ph. nattereri, and pair 8, that had an NOR and an adjacent C-band in Pl. diplolistris. Pair 8 also has NOR-bearing chromosomes in many other Pleurodema species. However, in these species, the NOR is located proximal to the centromere on the short arm, while in Pl. diplolistris it occurred distally on the long arm, a condition that may be considered a derived state. In Ph. nattereri, the NOR occurred on chromosome I 1 and differed from the other species of the Ph. biligonigerus group. In contrast, C-banding revealed a heterochromatic block near the centromere on the short arm of pair 3, a characteristic common to all members of this group of Physalaemus.

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The adsorption isotherms of MCl(2) (M = Mn, Ni, Cu, Zn and Cd) and FeCl3 by silica gel chemically modified with benzimidazole molecules (= SI(CH2)(3)-NC7H5N) were studied in ethanol solution at 298 K. A column made of modified silica was used to adsorb and preconcentrate the above metal ions from ethanol solution. Elution was done with 0.1 M hydrochloric acid in an ethanol/water mixture having a mole fraction of water of 0.8. The material was applied in the preconcentration of metal ions from commercial ethanol normally used as engine fuel.

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The objective of the present study was to characterize the fecundity of Callinectes ornatus from the northern coast of São Paulo, Brazil. To study the fecundity and its relationships to size, brood weight, and egg size, the ovigerous females were collected at 2-month intervals for two consecutive years (January, 1991 to November, 1992) in the Ubatuba region using a fishing boat equipped with an otter-trawl type of net. After collecting, the animals were screened, bagged, labeled, and stored frozen. Only data from 38 females carrying early stage eggs were considered. In the laboratory, the specimens were thawed at room temperature, the pleopod structure with the egg mass was removed and the eggs were carefully removed from the pleopods. The samples were then fixed in 10% formalin and stored in 70% ethanol, until the time for processing. Processing followed the method of Hines (1982, 1988). Following the frequency determination of carapace width and fecundity, mean egg number, mean volume and mean dry weight of brooded egg mass were determined for each class obtained. Data were analyzed by regressions of log-log transformations for allometric plots (Y = aX(b)) of reproductive variables versus carapace width. Carapace width was one of the main factors for the determination of fecundity, which ranged 171 570 +/- 94 634 eggs, with females of the same size class presenting a wide amplitude of variation. This supports the hypothesis that portunid females present staggered spawning, possibly presenting more than one period of reproduction within one year. The present species showed lower fecundity than the remaining portunids studied, but they did show a rapid and efficient embryonic development, presumably capable of assuring reproductive success.

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Arenaeus cribrarius is a mainly tropical crab that occurs in the Western Atlantic Ocean, Brazil being its type-locality. The species ranges from Vinevard Sound, Massachusetts, USA to La Paloma, Uruguay. Information about this species is scarce. The relative growth of A. cribrarius was analyzed, based on some morphometric relations, where the carapace width, excluding lateral spines (CW), was used as an independent variable. A total of 403 specimens (189 males and 214 females), was collected in Ubatuba, State of São Paulo, Brazil, with otter-trawls. The animals were sexed and sorted to maturation phase (juvenile or adult). Some measurements were made: carapace (length and width excluding lateral spines), abdomen (greatest width of the fifth somite in females and the sixth in males) and major chela (greatest length, width and height, dactylus length). This study was made by the application of the power function (y=a.x(b)) which was fitted to the data and the pattern of growth established for each parameter by the ''b''-value (constant of allometry), as positive allometry (b>1), negative allometry (b<1) or isometry (b=1). The morphometric relations of the carapace showed a tendency to isometry. In females, the abdominal width grew in positive allometry, higher in juveniles (b=1.33) than in adults (b=1.18). In this case, an overlap and discontinuity was noticed between the phases over a carapace width range of 55 to 70 mm, where the puberty molt occurs. The majority of relationships showed that the major chela of the males grew in positive allometry, however, the greatest allometric difference between the phases was observed towards the propodus length with 1.09 as juvenile and 1.26 as adult ''b''values. In the males, this variable showed an inflection between the CW range of 45' to 55 mm, where the transition to the maturation phase occurs. The relative growth of this species is similar to those of previously studied species. This indicates, that the propodus length and the abdominal width are the morphometric variables most appropriate to estimate the size of the beginning of the sexual maturity for males and females of this species, respectively.

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Dissection of 286 specimens of the Bothrops neuwiedi pubescens, combined with data on captive individuals, provided information on the reproductive biology of this viperid snake from southern Brazil. Females attained larger body sizes than males, and reproduction was seasonal with mating taking place in autumn when males were more frequently encountered. Vitellogenesis occurred from summer to spring (January-September), sperm storage during autumn and winter (May-September), ovulation and fertilization in early spring (September), embryonic development during middle spring and summer (October-March), and parturition in the summer (January-March). Embryonic development was estimated to last from three to five months, a shorter time than was previously reported. The number of offspring of Bothrops neuwiedi pubescens born in one litter can vary from four to 25 ((x) over bar = 11). Fecundity is correlated with maternal body size. Neonates measure 17-25 cm SVL. Inferred growth rate of juveniles was low (10 mm/month in first year), with males attaining sexual maturity at about 16 months, but maturity is delayed in females for at least two additional years.

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Mineral concretions in the digestive cells of bees were examined under transmission electron microscope and histochemically. Ultrastructure shows two types of mineral deposits: 1) mineral concretions which are organized in granules with a striking concentrically layered organization of opaque and clear zones and 2) electron dense granules which appear inside small vacuoles (0.4-0.7 mu m). These two structures are present in the apex of the digestive cells of the posterior midgut. Histochemical data reveal that mineral concretions are composed of calcium, iron and uric acid or its salts while calcium determination gives a positive reaction for electron dense granules. Morphological and chemical similarities between the mineral concretions of bees and those described for other insects suggest that they have an important physiological role regulating the composition of the internal environment and to avoid intoxication. Since concretions and granules are structurally distinct, it is suggested that they are functionally different.

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In insects the antennal lobes (AL) constitute the brain deutocerebrum. In bees they consist of two neuropil regions, each associated with one antenna, delimited by a layer of glial cells and somata of neurons. The neuropil is organized in distinct globular structures of dense synaptic axons coming from the olfactory organs of the antennae, known as glomeruli. In Apis mellifera, as in other eusocial species of bees, queens, workers, and drones perform different functions in the colony and consequently the organs associated with these functions undergo a differential development. In this paper we analyzed the structure and size of the differentiating AL of queens, workers, and drones during metamorphosis using light microscopy. During metamorphosis the neuropil enlarge and differentiates into concentric structures known as glomeruli. The results showed size, structural and temporal differences in the glomeruli development among the classes of individuals of the colony. The neuropil differentiation starts early and is faster in drones and newly emerged worker is the colony individual class with greater neuropil area in AL. These results are discussed taking in account the functions of the individuals in the colony. (C) Koninklijke Brill NV, Leiden, 2011.

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Food searching activity by subterranean termites involves workers, soldiers and nymphs. The present study was carried out for elucidating aspects of nymph foraging behavior in Brazil where the species Coptotermes gestroi (Wasmann, 1896) is exotic. Monitoring was conducted through making regular collections from seven different colonies for a period of 22 months, which exhibited the production of forager nymphs all year round. A biometric study was conducted to determine the instars of the forager nymphs collected. The identification of male and female nymphs was also conducted for establishing the sex proportion, which was slightly male-biased. From the 533 forager nymphs collected, 34 were from the 3rd instar, 280 from the 4th instar and 219 from 5th instar. The results suggest that 3rd instar nymphs were not too active in the foraging activities because they were collected only in one colony and in an insignificant quantity. (C) Koninklijke Brill NV, Leiden, 2011.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Methods developed since 1976 for harvesting, preparing and banding fish chromosomes are now commonly used for taxonomic and phylogenetic studies, genetic control and chromosome manipulations in fish breeding and in monitoring aquatic pollutants by examining chromosomal aberrations. These studies have chiefly concerned common temperate freshwater species; the same procedures, when applied to marine and coldwater fish, often provide unsatisfactory results, especially in cell culture. A concerted effort should be made in marine fish, and to develop molecular cytogenetic methods to provide a more powerful tool to study chromosomal evolution. © 1991 BRILL.

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The aim of this study was to evaluate the effect of delaying ovulation subsequent to superstimulation of follicular growth in beef cows (Bos indicus) on embryo recovery rates and the capacity of embryos to establish pregnancies. Ovulation was delayed by three treatments using either progesterone (CIDR-B®) or a GnRH agonist (deslorelin). Multiparous Nelore cows (n = 24) received three of four superstimulation treatments in an incomplete block design (n = 18 per group). Cows in Groups CTRL, P48 and P60 were treated with a CIDR-B device plus estradiol benzoate (EB, 4 mg, i.m.) on Day-5, while cows in Group D60 were implanted with deslorelin on Day-7. Cows were superstimulated with FSH (Folltropin-V® 200 mg), from Day 0 to 3, using twice daily injections in decreasing amounts. All cows were treated with a luteolytic dose of prostaglandin on Day 2 (08:00 h). CIDR-B devices were removed as follows: Group CTRL, Day 2 (20:00 h); Group P48, Day 4 (08:00 h); Group P60, Day 4 (20:00 h). Cows in Group CTRL were inseminated at 10, 20 and 30 h after first detected estrus. Ovulation was induced for cows in Group P48 (Day 4, 08:00 h) and Groups P60 and D60 (Day 4, 20:00 h) by injection of LH (Lutropin®, 25 mg, i.m.), and these cows were inseminated 10 and 20 h after treatment with LH. Embryos were recovered on Days 11 or 12, graded and transferred to synchronized recipients. Pregnancies were determined by ultrasonography around Day 100. Data were analyzed by mixed procedure, Kruskal-Wallis and Chi-square tests. The number of ova/embryos, transferable embryos (mean ± S.E.M.) and pregnancy rates (%) were as follows, respectively: Group CTRL (10.8 ± 1.8, 6.1 ± 1.3, 51.5), P48 (12.6 ± 1.9, 7.1 ± 1.0, 52.3), P60 (10.5 ± 1.6, 5.7 ± 1.3, 40.0) and D60 (10.3 ± 1.7, 5.0 ± 1.2, 50.0). There were no significant differences among the groups (P > 0.05). It was concluded that fixed time AI in association with induced ovulation did not influence embryo recovery. Furthermore, pregnancy rates in embryos recovered from cows with delayed ovulation were similar to those in embryos obtained from cows treated with a conventional superstimulation protocol. © 2002 Elsevier B.V. All rights reserved.

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Human papillomavirus (HPV) is believed to promote the oncogenic process, and the correlation between viral oncoproteins and dysfunction of p16 INK4A tumor suppressor protein in oral lesions is controversial. To test the hypothesis that anogenital HPV types participate in disruption of the regulation of p16INK4A suppressor protein in oral lesions, we analyzed 46 oral biopsy specimens for the presence of HPV 6/11 and 16/18 by in situ hybridization (ISH) and for p16INK4A expression by immunohistochemistry (IHC). Eighteen (39%) of the 46 oral lesions were HPV-positive and 28 (61%) were HPV-negative. HPV 6/11 DNA was found in 5 (11%) and HPV 16/18 in 13 (28%) of 46 biopsies. Nine of the 18 HPV-positive oral lesions (50%), assessed by catalyzed signal amplification coupled to ISH (CSA-ISH), gave high-intensity p16INK4A immunostaining. Focal and diffuse patterns were observed in 11/13 (77%) lesions with HPV 16/18, focal immunopositivity in 3/5 (80%) with HPV 6/11, and negative or sporadic p16-labeling in 18/28 (64%) without the presence of HPV DNA. These results showed a strong association between overexpression of p16 protein and malignant oral lesions, mainly those infected by HPV 16/18. We can conclude that high-risk HPV types are associated with p16 overexpression, and p16 may serve as a biomarker in oral cancer related to high-risk HPV infection.

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We investigated reproductive activity, courtship behavior, call structure, body size, clutch size, oviposition site, and reproductive mode of Hyla sp. (aff. ehrhardti). Males called in all months, but showed a peak of activity during the rainy season. Three pair formations were observed and courtship involved stereotyped behavioral sequences, including visual signaling. Males emitted three different vocalization types: advertisement calls, courtship calls, and a vocalization of unknown function. Females attained larger body sizes than males and deposited an average of 74.5 unpigmented eggs per clutch. Early larval stages are aquatic but restricted to water in constructed subterranean nests; subsequent to flooding of nests, exotrophic tadpoles live in ponds or streams. Courtship behavior in Hyla sp. (aff. ehrhardti) is complex and the diverse repertoire of limb movements, exhibited by males, probably provide visual stimuli to females in this nocturnal treefrog. Hyla sp. (aff. ehrhardti) belongs to the H. albomarginata group. Considering the reproductive modes in this group, the complexes of H. albosignata and of H. albofrenata can be considered more close related to each other than to the H. albomarginata complex. © Koninklijke Brill NV, Leiden, 2004.