First isolation and molecular characterization of Ehrlichia canis in Costa Rica, Central America

The present study investigated Ehrlichia species in blood samples from dogs suspected of clinical ehrlichiosis, using molecular and isolation techniques in cell culture. From a total of 310 canine blood samples analyzed by 16S rRNA nested PCR, 148 (47.7%) were positive for Ehrlichia canis. DNA from Ehrlichia chaffeensis or Ehrlichia ewingii was not detected in any sample using species-specific primers in separated reactions. Leukocytes from five PCR-positive dogs were inoculated into DH82 cells; successful isolation of E. canis was obtained in four samples. Partial sequence of the dsb gene of eight canine blood samples (including the five samples for in vitro isolation) was obtained by PCR and their analyses through BLAST showed 100% of identity with the corresponding sequence of E. canis in GenBank. This study represents the first molecular diagnosis, isolation, and molecular characterization of E. canis in dogs from Costa Rica. (C) 2010 Elsevier Ltd. All rights reserved.

Relation of genetic phylogeny and geographical distance of tick-borne encephalitis virus in central Europe

Tick-borne encephalitis virus (TBEV) is the most important arboviral agent causing disease of the central nervous system in central Europe. In this study, 61 TBEV E gene sequences derived from 48 isolates from the Czech Republic, and four isolates and nine TBEV strains detected in ticks from Germany, covering more than half a century from 1954 to 2009, were sequenced and subjected to phylogenetic and Bayesian phylodynamic analysis to determine the phylogeography of TBEV in central Europe. The general Eurasian continental east-to-west pattern of the spread of TBEV was confirmed at the regional level but is interlaced with spreading that arises because of local geography and anthropogenic influence. This spread is reflected by the disease pattern in the Czech Republic that has been observed since 1991. The overall evolutionary rate was estimated to be approximately 8x10(-4) substitutions per nucleotide per year. The analysis of the TBEV E genes of 11 strains isolated at one natural focus in Zd`ar Kaplice proved for the first time that TBEV is indeed subject to local evolution.

Bonding agent underneath sealant: shear bond strength to oil-contaminated

This study evaluated in vitro the shear bond strength of a resin-based pit-and-fissure sealant (Fluroshield - F) associated with either an ethanol-based (Adper Single Bond 2 - SB) or an acetone-based (Prime & Bond - PB) adhesive system under conditions of oil contamination. Mesial and distal enamel surfaces from 30 sound third molars were randomly assigned to 2 groups (n=30): I - no oil contamination; II - oil contamination. Contamination (0.25 mL during 10 s) was performed after 37% phosphoric acid etching with an air/oil spray. The specimens were randomly assigned to subgroups, according to the bonding protocol adopted: subgroup A - F was applied to enamel without an intermediate bonding agent layer; In subgroups B and C, SB and PB, respectively, were applied, light-cured, and then F was applied and light-cured. Shear bond strength was tested at a crosshead speed of 0.5 mm/min in a universal testing machine. Means (± SD) in MPa were: IA-11.28 (±1.84); IIA-12.02 (±1.15); IB-9.73 (±2.38); IIB-9.62 (±2.29); IC-28.30 (±1.63); and IIC-25.50 (±1.91). It may be concluded that the oil contamination affected negatively the sealant bonding to enamel and the acetone-based adhesive system (PB) layer applied underneath the sealant was able to prevent its deleterious effects to adhesion.

Permeability of different groups of maxillary teeth after 38% hydrogen peroxide internal bleaching

This study evaluated the influence of internal tooth bleaching with 38% hydrogen peroxide (H2O2) on the permeability of the coronal dentin in maxillary anterior teeth and premolars. Seventy teeth (14 per group) were used: central incisors (CI), lateral incisor (LI), canines (C), first premolars (1PM) and second premolars (2PM). Pulp chamber access and transversal sectioning at 2 mm from the cementoenamel junction were performed and the specimens were divided into 2 groups (n= 7): a) no treatment and b) bleaching with 38% H2O2. The bleaching agent was applied to the buccal surface and to the pulp chamber for 10 min. This procedure was repeated 3 times. The specimens were processed histochemically with copper sulfate and rubeanic acid, sectioned longitudinally, and digitalized in a scanner. The area of stained dentin was measured using Image Tool software. Data were analyzed statistically by ANOVA and Tukey's HSD test (?=0.05). There was statistically significant difference (p<0.001) among the untreated groups, CI (0.23 ± 0.26) having the lowest permeability and LI (10.14 ± 1.89) the highest permeability. Among the bleached groups, dentin permeability was increased in all groups of teeth except for 2PM. It may be concluded that bleaching with 38% H2O2 affected dentin permeability near the pulp chamber in maxillary anterior teeth and in first and second premolars.

Fire management and the nesting of Athene cunicularia (Aves, Strigidae) in grasslands in central Cerrado, Brazil

Fire management is a common practice in several reserves in the Cerrado, but its influences on bird reproduction remain unknown. In addition, the nesting biology of the Burrowing Owl (Athene cunicularia) has been studied in numerous environments, but not in tropical grasslands managed by fire. This study examined the effects of fire management on the nesting biology of A. cunicularia in Emas National Park, State of Goias, central Brazilian Cerrado. We compared the number of breeding pairs and their burrows in October and November 2009 at 15 study sites in grasslands managed by fire (firebreaks) and unmanaged grasslands adjacent to and distant from firebreaks. We visited active burrows two-four times and described the burrow entrances and sentinel sites and counted and observed adults and young. A total of 19 burrows were found at firebreaks. One and two burrows were found in grasslands adjacent to and distant from firebreaks, respectively. For all burrows found, one to three young reached the adult size, being able to fly and/or run in early November. The 22 burrows found were in the ground, associated or not with termite and ant nests. Most (86.4%) burrows had only one entrance. Only three burrows had two or three entrances. Structures used as sentinel perches by adults were mounds in front of the burrow entrances, termite nests, shrubs and trees. Most of these sentinel sites were shorter than 2 m high and located less than 10 m from the burrow entrance. At Emas National Park, firebreaks appear to provide more attractive conditions to the nesting of A. cunicularia than unmanaged grasslands, likely because of the short herbaceous stratum due to frequent burning of firebreaks. This study suggests that fire management provides suitable conditions for the successful reproduction of A. cunicularia in firebreaks at Emas National Park.

Trichomycterus dali: a new highly troglomorphic catfish (Silurifomes: Trichomycteridae) from Serra da Bodoquena, Mato Grosso do Sul State, Central Brazil

Trichomycterus dali, new species, is described from flooded limestone caves in Serra da Bodoquena karst area, State of Mato Grosso do Sul, Central Brazil. The new species is diagnosed by a unique character in the genus, the presence of conspicuous, ridge-like adipose folds lining dorsally throughout the body. Trichomycterus dali can be further distinguished readily from epigean congeners by the reduction of eyes and skin pigmentation (except for T. gorgona), and from remaining congeners (i.e., all hypogean plus T. gorgona) by the total loss of eyes, not visible externally (except for T. sandovali and T. spelaeus). Other diagnostic features includes very long barbels, especially the nasal (99.3-143.5% HL) and the maxillary (97.0-131.3% HL), pectoral-fin ray count reaching I,9 and a unique cranial fontanel with a conspicuous constriction on the meeting point of supraoccipital and the two frontal bones. The troglobitic status of the species is suggested by the presence of troglomorphisms on an advanced degree, especially the reduction of skin pigmentation, the total loss of eyes and the enlarged barbels. In addition, the presence of a well developed adipose fold in adults may indicate a distinctive adaptation acquired by neoteny to withstand the food scarce conditions of its hypogean habitat.

Ituglanis mambai, a new subterranean catfish from a karst area of Central Brazil, rio Tocantins basin (Siluriformes: Trichomycteridae)

Ituglanis mambai, new species, is described from a cave in the Mambaí karst area, State of Goiás, Central Brazil. The new species distinguishes from epigean and cave congeners by the combination of the following characteristics: posterior supraoccipital fontanel absent; pectoral-fin rays usually i,7; six pleural ribs; total vertebrae 37-38 behind Weberian apparatus; shorter predorsal length (65.1-70.8% SL); shorter caudal peduncle length (8.4-11.9% SL); shorter dorsal-fin base length (7.7-11.3% SL); wider interobital width (29.2-36.5% HL); larger mouth width (43.4-64.0% HL); intermediate between epigean and other cave Ituglanis species as regards to both eyes (diameter varying from 0.5 to1.0 mm in adults, 7.8-10.1 % HL) and pigmentation, composed by irregular light brown spots along the body. The latter indicate the troglobitic status for I. mambai. In addition, this species has the maxillae with a discrete medial-posterior projection; fronto-lacrimal one half-length of the maxillae and pointed backwards; posterior process of palatine half its length, with a tenuous medial concavity; 14 dorsal and 12 ventral procurrent rays. In the natural habitat, I. mambai displayed cryptobiotic habits, trying to hide in the graveled bottom or under boulders when disturbed, apparently showing a negative response to light. It was observed a preference to slow-moving waters. Recent flood marks were observed in the stream conduit in March/April 2007 (end of the rainy season) when less individuals were observed on 300 m of the subterranean stream compared to September 2004 (end of the dry season).

Répteis da Estação Ecológica Serra Geral do Tocantins, Brasil Central

Os Cerrados sul-americanos abrigam alta diversidade de répteis, incluindo elevado número de endemismos. No entanto, o conhecimento desta diversidade é ainda incompleto frente à acelerada transformação das paisagens naturais no Brasil central. Constituem, portanto, uma das regiões prioritárias para estudo e conservação da biodiversidade mundial. Estudos intensivos sobre a fauna de répteis do Cerrado são necessários e urgentes para melhor compreensão dos processos que levaram à sua origem e distribuição e para subsidiar ações de conservação. Por meio de métodos padronizados, amostramos duas regiões ainda inexploradas da Estação Ecológica Serra Geral do Tocantins, situada na região do Jalapão. Registramos 45 espécies de répteis para a EESGT e entorno, o que representa uma riqueza alta e comparável à de outras regiões bem amostradas do Cerrado. Curvas de acumulação e estimadores indicam que a riqueza local de lagartos e anfisbenídeos aproxima-se da riqueza real enquanto a de serpentes é subestimada. A distribuição não-aleatória das espécies na paisagem concorda com evidências anteriores sugerindo utilização diferencial dos hábitats pelos répteis. Reunindo os resultados do presente estudo com os de levantamentos prévios realizados na região, registramos 88 espécies de répteis para o Jalapão sendo oito registros novos que incluem Bachia oxyrhina uma espécie recém descrita da região. As espécies da área apresentam três padrões gerais de distribuição: (1) espécies endêmicas do Cerrado, (2) espécies compartilhadas com domínios da diagonal de formações abertas sul-americanas, e (3) espécies de ampla ocorrência, compartilhadas também com ecossistemas florestais. Prevalecem espécies de ampla distribuição, porém é grande o número de espécies típicas do Cerrado, incluindo cinco possivelmente endêmicas do Jalapão, e há contribuição importante da fauna da Caatinga. A distribuição dos répteis em escala local e regional demonstra a necessidade de considerar a heterogeneidade paisagística para o planejamento de diretrizes visando à conservação em regiões do Cerrado. Por sua grande extensão, posição biogeográfica e complexidade de relevo e tipos de hábitat, a EESGT tem papel fundamental para a preservação e conhecimento da diversidade de répteis do Cerrado.

Central chemoreceptors and neural mechanisms of cardiorespiratory control

The arterial partial pressure (P CO2) of carbon dioxide is virtually constant because of the close match between the metabolic production of this gas and its excretion via breathing. Blood gas homeostasis does not rely solely on changes in lung ventilation, but also to a considerable extent on circulatory adjustments that regulate the transport of CO2 from its sites of production to the lungs. The neural mechanisms that coordinate circulatory and ventilatory changes to achieve blood gas homeostasis are the subject of this review. Emphasis will be placed on the control of sympathetic outflow by central chemoreceptors. High levels of CO2 exert an excitatory effect on sympathetic outflow that is mediated by specialized chemoreceptors such as the neurons located in the retrotrapezoid region. In addition, high CO2 causes an aversive awareness in conscious animals, activating wake-promoting pathways such as the noradrenergic neurons. These neuronal groups, which may also be directly activated by brain acidification, have projections that contribute to the CO2-induced rise in breathing and sympathetic outflow. However, since the level of activity of the retrotrapezoid nucleus is regulated by converging inputs from wake-promoting systems, behavior-specific inputs from higher centers and by chemical drive, the main focus of the present manuscript is to review the contribution of central chemoreceptors to the control of autonomic and respiratory mechanisms.

Stress distribution in the cervical region of an upper central incisor in a 3D finite element model

The aim of this study was to evaluate the stress distribution in the cervical region of a sound upper central incisor in two clinical situations, standard and maximum masticatory forces, by means of a 3D model with the highest possible level of fidelity to the anatomic dimensions. Two models with 331,887 linear tetrahedral elements that represent a sound upper central incisor with periodontal ligament, cortical and trabecular bones were loaded at 45º in relation to the tooth's long axis. All structures were considered to be homogeneous and isotropic, with the exception of the enamel (anisotropic). A standard masticatory force (100 N) was simulated on one of the models, while on the other one a maximum masticatory force was simulated (235.9 N). The software used were: PATRAN for pre- and post-processing and Nastran for processing. In the cementoenamel junction area, tensile forces reached 14.7 MPa in the 100 N model, and 40.2 MPa in the 235.9 N model, exceeding the enamel's tensile strength (16.7 MPa). The fact that the stress concentration in the amelodentinal junction exceeded the enamel's tensile strength under simulated conditions of maximum masticatory force suggests the possibility of the occurrence of non-carious cervical lesions such as abfractions.

OSL age determinations of Pleistocene fluvial deposits in Central Amazonia

Absolute dating methods have been used in chronological studies of geological processes and sedimentary units of Quaternary age in Central Amazonia, Brazil. Although radiocarbon dating has been very useful in archaeological research and soil studies, the temporal interval of this method is inefficient in evaluating the sedimentation aspects and geological events from the beginning of the Quaternary in the Amazon basin. The use of crystal luminescence dating has been one of the most promising tool for determining the absolute dating of Quaternary deposits in the Amazonian region. Optically stimulated luminescence (OSL) dating, following the MAR and SAR protocols, in a tectonic-sedimentary study of Quaternary fluvial deposits in the confluence area of the Negro and Solimões rivers, indicated ages from 1.3 (Holocene) to about 67.4 kyears (Late Pleistocene) for these sediments. Low radioactive isotope concentrations were found about 2ppm for 235U and 238U; 5ppm for 232Th; and the 40K concentrations were almost zero. A comparison was made between MAR and SAR protocols taking into account the fluvial depositional process.

New data on the natural history and description of the immatures of Fulgeochlizus bruchi, a bioluminescent beetle from Central Brazil (Elateridae, Pyrophorini)

The mature larva and pupa of Fulgeochlizus bruchi (Candèze, 1896) are described and illustrated. Bioluminescent patterns are also given. Comments, new data on the first instar larva and natural history data are presented. The first instar larvae differ from the mature larvae mainly in their chaetotaxy, which is sparse and more symmetrically distributed.

Revision of the species of the genus Cathorops (Siluriformes: Ariidae) from Mesoamerica and the Central American Caribbean, with description of three new species

The ariid genus Cathorops includes species that occur mainly in estuarine and freshwater habitats of the eastern and western coasts of southern Mexico, Central and South America. The species of Cathorops from the Mesoamerica (Atlantic slope) and Caribbean Central America are revised, and three new species are described: C. belizensis from mangrove areas in Belize; C. higuchii from shallow coastal areas and coastal rivers in the Central American Caribbean, from Honduras to Panama; and C. kailolae from río Usumacinta and lago Izabal basins in Mexico and Guatemala. Additionally, C. aguadulce, from the río Papaloapan basin in Mexico, and C. melanopus from the río Motagua basin in Guatemala and Honduras, are redescribed and their geographic distributions are revised.

A new pale-spotted species of Hypostomus Lacépède (Siluriformes: Loricariidae) from the rio Tocantins and rio Xingu basins in central Brazil

A new species of the genus Hypostomus Lacépède (Siluriformes, Loricariidae) from rio Tocantins and rio Xingu basins in central Brazil, is described. The new species is distinguished from its congeners by a unique combination of pale blotches over a darker background on head, body and fins, and conspicuous keels on head, predorsal region and lateral plates. Comments on the pale-spotted species of Hypostomus are provided.

Estudo de flebotomíneos (Diptera, Psychodidae) em área urbana do município de Bonito, Mato Grosso do Sul, Brasil

O objetivo do trabalho foi identificar a fauna flebotomínea em áreas do perímetro urbano do município de Bonito, Mato Grosso do Sul, Brasil. O estudo foi desenvolvido de março de 2005 a fevereiro de 2006, em 17 ecótopos distribuídos em 12 locais, três no Centro e nove em diferentes bairros. As capturas foram realizadas quinzenalmente com armadilhas automáticas luminosas. Capturou-se 2.680 espécimes, 2.283 machos e 397 fêmeas, de 12 espécies, Brumptomyia avellari, Brumptomyia brumpti, Bichromomyia flaviscutellata, Evandromyia corumbaensis, Evandromyia sallesi, Lutzomyia longipalpis, Micropygomyia acanthopharynx, Micropygomyia quinquefer, Nyssomyia whitmani, Psathyromyia aragaoi, Psathyromyia punctigeniculata e Psathyromyia shannoni. Lutzomyia longipalpis, vetora do agente da leishmaniose visceral americana, foi a espécie mais freqüente e a mais abundante, representando 93,5% dos flebotomíneos capturados e índice de abundância padronizado de 0,85. Com freqüência mais expressiva nos ecótopos próximos de galinheiro e de pocilga, esta espécie foi capturada em todos os meses do ano, com picos no verão, inverno e primavera. As demais espécies foram pouco freqüentes. Ressalta-se que a captura de Bichromomyia flaviscutellata, no intradomicilio e peridomicílio, nas proximidade de mata remanescente, tem grande significado epidemiológico uma vez que essa espécie é a principal vetora da Leishmania (Leishmania) amazonensis, agente etiológico da leishmaniose cutânea difusa anérgica. Portanto, na área urbana de Bonito foram encontradas duas espécies que comprovadamente participam da transmissão de leishmanioses, Lutzomyia longipalpis e Bichromomyia flaviscutellata, ambas encontradas naturalmente infectadas pelos respectivos agentes.