EISCAT observations of plasma convection and the high-latitude, winter F-region during substorm activity

A 24 h period of observations by the EISCAT radar and other ground-based instrumentation is used to study the role of plasma convection in determining the morphology of the high-latitude F-region during winter. It is suggested that, in the afternoon sector of the polar convection pattern, rapid zonal (westward) flows caused low F-region electron densities due to an extension of the mid-latitude trough far into the sunlit hemisphere. Low densities on the dawn side prior to 0600 UT may also have been due to a trough-like feature. Although the generation mechanism is unclear, the trough may be the fossil remnant of a substorm. Around midnight, high F-region densities were seen, probably due to plasma flow emerging from the cap through soft particle precipitation in the auroral oval. Two substorms occurred at times when the radar was south of the auroral oval. Both caused enhanced convection speeds, a swing to equatorward flow, enhanced E-region densities and a depleted F-region. The first was seen as a Westward Travelling Surge, and the swing to purely southward flow which followed the surge front did not return to westward flows until 80–110 min later. The Harang discontinuity was observed co-rotating eastwards between the substorms, 65 ± 30 min before the separatrix between the dawn and dusk convection cells.

SEM Study of Apical Morphological Alterations in Primary Teeth with Vital and Necrotic Pulps

This study evaluated, by SEM, the morphology of human primary teeth roots. Twenty-four teeth were divided into 3 groups: pulp vitality (group I) and pulp necrosis without (group II) and with apical periodontitis (group III). Roots were analyzed by the presence of periodontal ligament (PDL) fibers and resorption areas. In groups I and II, presence of PDL fibers and absence of resorption were observed in all cases (100%), while all specimens (100%) of group III showed no PDL fibers and resorption areas. In conclusion, there are morphological differences in the apical region of primary teeth with different pulpal and periapical pathologies.

Chemical and Morphological Features of Dental Composite Resin: Influence of Light Curing Units and Immersion Media

Aims: The study evaluated the influence of light curing units and immersion media on superficial morphology and chemistry of the nanofilled composite resin Supreme XT (3M) through the EDX analysis and SEM evaluation. Light curing units with different power densities and mode of application used were XL 3000 (480 mW/cm(2)), Jet Lite 4000 Plus (1230mW/cm(2)), and Ultralume Led 5 (790 mW/cm(2)) and immersion media were artificial saliva, Coke(R), tea and coffee, totaling 12 experimental groups. Specimens (10 mm X 2 mm) were immersed in each respective Solution for 5 min, three times a day, during 60 days and stored in artificial saliva at 37 degrees C +/- 1 degrees C between immersion periods. Topography and chemical analysis was qualitative. Findings: Groups immersed in artificial saliva, showed homogeneous degradation of matrix and deposition of calcium at the material surface. Regarding coffee, there was a reasonable chemical degradation with loss of load particles and deposition of ions. For tea, superficial degradation occurred in specific areas with deposition of calcium, carbon. potassium and phosphorus. For Coke(R), excessive matrix degradation and loss of load particles with deposition of calcium, sodium, and potassium. Conclusion: Light curing units did not influence the superficial morphology of composite resin tested, but the immersion beverages did. Coke(R) affected material`s surface more than did the other tested drinks. Microsc. Res. Tech. 73:176-181, 2010. (c) 2009 Wiley-Liss Inc.

Effect of different bleaching systems on the ultrastructure of bovine dentin

The aim of this study was to evaluate in vitro the effect of different in-office bleaching systems on the surface morphology of bovine dentin. Thirty tooth fragments measuring 4 x 4mm, containing enamel and dentin, were obtained from the crowns of extracted bovine incisors. Samples were subjected to simulated intracoronal bleaching techniques using conventional (Opalescence Endo (R) and Whiteness Super Endo (R)) and light-activated systems (Opalescence Xtra (R) and Whiteness HP Maxx (R)). Controls were treated with either sodium perborate mixed with 10% hydrogen peroxide or no bleaching agent. The samples were observed under SEM and the recorded images were evaluated for topographic alterations. The ultrastructural alterations of dentin observed in this study varied greatly between groups according to the products used. Higher pH products (Whiteness HP Maxx (R) and Opalescence Xtra (R)) associated with in-office techniques yielded better maintenance of dentin ultrastructure. Apparently, both low pH and hydrogen peroxide oxidation play a role in altering the ultrastructure of dentin during internal dental bleaching. The use of alkaline products with reduced time of application (in-office techniques) may decrease such morphological alterations.

Redescription of Anopheles (Nyssorhynchus) lutzii, and Resurrection of Anopheles guarani From Synonymy With An. lutzii (Diptera: Culicidae)

Anopheles lutzii Cruz (Diptera: Culicidae) is redescribed using specimens collected in Pariquera-Acu, Vale do Ribeira, state of Sao Paulo, southeastern Mata Atlantica, Brazil. Specimens of An. lutzii from Vale do Ribeira and two females from Nova Friburgo, Rio de Janeiro, are compared with three syntypes of An. lutzii, deposited in the Instituto Oswaldo Cruz, Rio de Janeiro. Comparisons of external morphology of specimens from the type locality of Anopheles guarani Shannon demonstrate it is a valid species, and that Anopheles niger Theobald is conspecific with Anopheles guarani stat. rev. The adult male, male terminalia, fourth-instar larva, and pupa of An. guarani stat. rev. are described for the first time. Diagnostic characters of the male and female, male terminalia, fourth-instar larva and pupa of An. lutzii and An. guarani stat. rev. are illustrated. An. guarani stat. rev. is herein resurrected from the synonymy with An. lutzii, and Anopheles niger comb. nov. is transferred from the synonymy with An. lutzii to the synonymy of An. guarani stat. rev.

In Vitro Propagation of Heliconia bihai (L.) L. from Zygotic Embryos

(In vitro Propagation of Heliconia bihai L. from Zygotic Embryos). The internal morphology of embryos from immature and mature fruits of Hcliconia bihai (L.) L. cv. Lobster Claw Two was examined. Embryos were inoculated into MS media (full MS and 1/2 MS) and GA(1) (0.2.5 and 5 mg L(-1)) with either sucrose or glucose. These plantlets were then replicated and transferred to MS medium (full MS or 1/2 MS) with 0 or 2.5 mg L(-1) BAP and their multiplication was evaluated 30 and 45 days after inoculation. The genetic variability of the multiplied plants was estimated using isoenzyme analyses. The internal morphology of the mature embryos revealed their tissues to be in more advanced stages of differentiation than immature embryos. In the conversion phase, 85% of the inoculated embryos developed into plants in the 1/2 MS medium with sucrose, in contrast to only 41% of the embryos that were cultivated with glucose. In the multiplication phase, plants cultivated in 1/2 MS medium with 2.5 mg L(-1) BAP demonstrated more buds. Isoenzyme analyses showed pattern changes in terms of the color intensity and the migration of some of the bands. These results may be associated with differences in the ages of the mother plants and of the plantlets obtained in vitro.

Comparative Cranial Osteology of Fossorial Lizards From the Tribe Gymnophthalmini (Squamata, Gymnophthalmidae)

Squamates (lizards, snakes and amphisbaenians) are represented by a large number of species distributed among a wide variety of habitats. Changes in body plan related to a fossorial habit are a frequent trend within the group and many morphological adaptations to this particular lifestyle evolved convergently in nonrelated species, reflecting adaptations to a similar habitat. The fossorial lifestyle requires an optimal morphological organization for an effective use of the available resources. Skeleton arrangement in fossorial squamates reflects adaptations to the burrowing activity, and different degrees of fossoriality can be inferred through an analysis of skull morphology. Here, we provide a detailed description of the skull morphology of three fossorial gymnophthalmid species: Calyptommatus nicterus, Scriptosaura catimbau, and Nothobachia ablephara. J. Morphol. 271: 1352-1365, 2010. (C) 2010 Wiley-Liss, Inc.

A new species of Potamotrygonocestus Brooks & Thorson, 1976 (Eucestoda : Tetraphyllidea) from Plesiotrygon iwamae Rosa, Castello & Thorson (Mylliobatoidea : Potamotrygonidae) and a redescription of Potamotrygonocestus chaoi Marques, Brooks & Araujo, 2003

Potamotrygonocestus Brooks & Thorson, 1976 is currently represented by six recognised species of tetraphyllidean cestodes inhabiting Neotropical freshwater stingrays. Potamotrygonid stingrays examined to date have included only a single specimen of Plesiotrygon iwamae. Only one species of tetraphyllidean, Potamotrygonocestus chaoi Marques, Brooks & Araujo, 2003, has been described from this host, and this description was based on limited material. New efforts to document the diversity in this host species resulted in the collection of eight additional specimens of P. iwamae, one of these from the upper Rio Solimoes, at Sao Paulo de Olivenca Amazonas during September, 2003, and seven from the Baia do Marajo, Para, during November, 2003. The specimen from the upper Solimoees was found to be infected with P. chaoi. Voucher material from this stingray was used for the redescription of this cestode, which is characterized by strobila 8.78-22.83 mm long and a great number of proglottides, 58-93; the new material provided strobilar length and proglottis counts for complete worms. Potamotrygonocestus marajoara n. sp. is the second species of this genus reported from Plesiotrygon iwamae, although it appears to be restricted to the lower Amazon. This new species resembles P. chaoi in possessing filitriches and blade-like spinitriches on the scolex, cephalic peduncle and cirrus, but differs from other species of the genus in the number of testes, which is 44 on average per proglottis, and by having apical sucker measuring 95-175 mu m in length. Additional data on the distribution and morphology of the microtriches and a detailed description of the female reproductive system are also provided in this study.

Comparative Internal Structure of Dorsal Lips and Radiolar Appendages in Sabellidae (Polychaeta) and Phylogenetic Implications

Fan worms (Sabellidae) possess paired modified prostomial structures at the base of the radiolar crown, dorso-lateral to the mouth, called dorsal lips. The dorsal lips are involved in the sorting of particles collected by the radiolar crown. The range of variation in the morphology of dorsal lips is extensive, and probably this is not only due to adaptations to different environments and feeding preferences but also due to phylogenetic constraints. In this study, we describe and compare the morphology of dorsal lips in a range of sabellid taxa based on histological cross-sections of these structures, and compare our data and terminology with those of previous studies. Dorsal lips are maintained erect in most taxa by a modified radiole fused to them known as dorsal radiolar appendage. We suggest that dorsal radiolar appendages with an internal supporting axis (cellular or acellular) and probably also the ventral lips are synapomorphies of the family. J. Morphol. 272: 302-319, 2011. (C) 2010 Wiley-Liss, Inc.

Two new species of Loricariidae (Teleostei: Siluriformes) from main channels of the upper and middle Amazon Basin, with discussion of deep water specialization in loricariids

Hemiancistrus pankimpuju, new species, and Panaque bathyphilus, new species, are described from the main channel of the upper (Maranon) and middle (Solimoes)Amazon River, respectively. Both species are diagnosed by having a nearly white body, long filamentous extensions of both simple caudal-fin rays, small eyes, absence of an iris operculum and unique combinations of morphometrics. The coloration and morphology of these species, unique within Loricariidae, are hypothesized to be apomorphies associated with life in the dark, turbid depths of the Amazon mainstem. Extreme elongation of the caudal filaments in these and a variety of other main channel catfishes is hypothesized to have a mechanosensory function associated with predator detection.

On the Generic Identity of Siagonodon brasiliensis, with the Description of a New Leptotyphlopid from Central Brazil (Serpentes: Leptotyphlopidae)

The geographic variation and hemipenial morphology of Siagonodon brasiliensis are described based on a comprehensive sample, allowing the reappraisal of its generic identity, and the proposal of a new nomenclatural combination. We suggest that the presence of two supralabials, as mentioned in the original description of S. brasiliensis, is not a common feature for this species, occurring at low frequencies throughout its geographic distribution. Based on a diagnosis presented in a recently published paper, as well as on additional external traits and on hemipenial characters, we recognize Siagonodon brasiliensis as a species of the genus Tricheilostoma. In addition, a new species of worm snake of the genus Siagonodon is described from the savannas of the state of Tocantins, Brazil. The new species differs from other congeners by having a slightly acuminate snout in lateral and ventral views, subcircular rostral in dorsal view, and 12 scale rows around middle of tail. The diagnosis of the genus Siagonodon is revised and expanded based on direct observation of morphological characters.

Contributions to the taxonomy of the Normanellidae (Copepoda, Harpacticoida): description of a new genus from the Brazilian continental shelf and re-assignment of Pseudocletodes vararensis Scott & Scott, 1893 (ex Nannopodidae)

A new genus and species of Normanellidae (Copepoda, Harpacticoida), Paranaiara inajae gen. et sp. nov., is described from the continental shelf off the northern coast of Sao Paulo State, Brazil. The new genus differs from the type genus Normanella Brady, 1880 and Sagamiella Lee & Huys, 1999 in its presence of lamelliform caudal rami, a maxillulary endopod represented by 2 setae, an unarmed maxillipedal syncoxa, and reduced setation on P2 enp-2 (without outer spine) and P3 enp-2 (with only 2 inner setae). All these apomorphic character states are shared with the genus Pseudocletodes Scott & Scott, 1893, formerly placed in the family Nannopodidae (ex Huntemanniidae) and here assigned to the Normanellidae. Pseudocletodes can be differentiated from Paranaiara by the loss of the P1 endopod and of the inner seta on P2-P4 enp-1, the presence of only 2 inner setae on P2 enp-2 (instead of 3) and only 1 inner seta on P4 exp-3 (instead of 2), the presence of a second inner seta on P4 enp-2 (instead of 1), the morphology of the fifth pair of legs which are not medially fused and have only 3 endopodal elements (instead of 4) in the male, and the well developed caudal ramus seta V (instead of rudimentary). It is postulated that prehensility of the P1 endopod was secondarily lost in the common ancestor of Paranaiara and Pseudocletodes. An updated family diagnosis of the Normanellidae and a dichotomous identification key to the 22 currently valid species are presented.

Postnatal fluoxetine treatment affects the development of serotonergic neurons in rats

The goal of the present study was to investigate morphological changes in the serotonergic neurons/terminals in the dorsal (DR) and median (MnR) raphe nuclei and on the hippocampal dentate gyrus (DG) in neonatal rats treated from the 1st to the 21st postnatal day with fluoxetine (10 mg/kg sc, daily) or drug vehicle (0 9% saline 1 ml/kg). The results show that postnatal chronic treatment with fluoxetine promoted. (1) a smaller body weight increase during the pre-weaning period; (2) smaller number of 5-HT neurons in the DR, (3) smaller 5-HT neuronal cell bodies (area, perimeter and diameter) in the DR and the MnR and (4) diminished serotonergic terminals in the DG. These data suggest that the development of the serotonergic system was impaired and that early exposure to fluoxetine damaged the morphology of 5-HT neurons in young adult rats While these findings are consistent with other work, more studies are needed to better clarify the effects of postnatal chronic treatment with fluoxetine on the serotonergic system and, consequently, on the functions modulated by serotonin (C) 2010 Elsevier Ireland Ltd All rights reserved

A study of the catecholaminergic inputs to the dorsal premammillary nucleus

The dorsal premammillary nucleus (PMd) is one of the most responsive hypothalamic sites during exposure to a predator or its odor, and to a context previously associated with a predatory threat; and lesions or pharmacological inactivation centered therein severely reduced the anti-predatory defensive responses. Previous studies have shown that beta adrenergic transmission in the PMd seems critical to the expression of fear responses to predatory threats. In the present study, we have investigated the putative sources of catecholaminergic inputs to the PMd. To this end, we have first described the general pattern of catecholaminergic innervation of the PMd by examining the distribution and morphology of the tyrosine hydroxylase (TH) immunoreactive fibers in the nucleus; and next, combining Fluoro Gold (FG) tracing experiments and TH immunostaining, we determined the putative sources of catecholaminergic inputs to the nucleus. Our results revealed that the PMd presents a moderately dense plexus of catecholaminergic fibers that seems to encompass the rostral pole and ventral border of the nucleus. Combining the results of the FG tract-tracing and TH immunostaining, we observed that the locus coeruleus was the sole brain site that contained double FG and TH immunostained cells. In summary, the evidence suggests that the locus coeruleus is seemingly a part of the circuit responding to predatory threats, and, as shown by the present results, is the sole source of catecholaminergic inputs to the PMd, providing noradrenergic inputs to the nucleus, which, by acting via beta adrenoceptor, seems to be critical for the expression of anti-predatory responses. (C) 2011 Elsevier Ireland Ltd. All rights reserved.

Rod bipolar cells in the retina of the capuchin monkey (Cebus apella): Characterization and distribution

Rod bipolar cells in Cebus apella monkey retina were identified by an antibody against the alpha isoform of protein kinase C (PKC alpha). which has been shown to selectively identify rod bipolars in two other primates and various mammals. Vertical sections were used to confirm the identity of these cells by their characteristic morphology of dendrites and axons. Their topographic distribution was assessed in horizontal sections; counts taken along the dorsal, ventral, nasal, and temporal quadrants. The density of rod bipolar cells increased from 500 to 2900 cells/mm(2) at 1 mm from the fovea to reach a peak of 10,000-12,000 cellss/mm(2) at 4 mm, approximately 5 deg of eccentricity, and then gradually decreased toward retinal periphery to values of 5000 cells/mm(2) or less. Rod to rod bipolar density ratio remained between 10 and 20 across most of the retinal extension. The number of rod bipolar cells per retina was 6,360,000 +/- 387,433 (mean +/- S.D., n = 6). The anti-PKC alpha antibody has shown to be a good marker of rod bipolar cells of Cebus, and the cell distribution is similar to that described for other primates. In spite of the difference in the central retina, the density variation of rod bipolar cells in the Cebus and Macaca as well as the convergence from rod to rod bipolar cells are Generally similar, suggesting that both retinae stabilize similar sensitivity (as measured by rod density) and convergence.