1-(2-furoyl)-3-(1-naphthyl)thiourea

In the title compound, C(16)H(12)N(2)O(2)S, the carbonylthiourea group forms dihedral angles of 75.4 (1) and 13.1 (2)degrees, respectively, with the naphthalene ring system and furan ring. The molecule adopts a trans-cis configuration with respect to the positions of the furoyl and naphthyl groups relative to the S atom across the thiourea C-N bonds. This geometry is stabilized by an N-H center dot center dot center dot center dot O intramolecular hydrogen bond. In the crystal structure, molecules are linked by N-H center dot center dot center dot S hydrogen bonds, forming centrosymmetric dimers which are interlinked through C-H center dot center dot center dot pi interactions.

TAXONOMIC POSITION OF GUIRATINGIA MENDESI (MEGADESMIDAE) AND THE EVOLUTION OF PERMIAN ENDEMIC BIVALVE FAUNA OF THE PARANA BASIN, BRAZIL

The unusual bivalve Guiratingia mendesi is redescribed from the original material. Detailed analysis of hinge and muscle scars allows more refined designation of its taxonomic position and affinities to other Permian bivalves from the Parana Basin. Guiratingia mendesi is characterized by very small, anteriorly expanded shells, with a great number of muscle striae within the area delimited by the pallial line. A flattened area is noted alongside the commissure of shell. The presence of a triangular blunt tooth in the right valve allows its designation to Megadesmidae. The absence of accessory muscle scars ""a"" and ""b"" and pedal elevator indicate that the genus belongs to the Plesiocyprinellinae, a group of bivalves considered endemic to the Passa Dois Group. Guiratingia mendesi is found, however, in limestones of the Palermo Formation (Middle Artinskian), nearly 100 in below the base of the Irati Formation (Late Artinskian). Until now, it was believed that within the Permian succession of Parana Basin, pre-Irati bivalves were all gondwanic or cosmopolitan. Guiratingia mendesi was an endemic, active burrower that resembles Runnegariella fragilis from the Permian Teresina Formation. This indicates that during Palermo times restricted paleogeographic conditions have existed within the huge Parana epeiric sea, favoring endemicity, probably in marine bayments close to its margins. The presence of an anteriorly expanded shell in G mendesi is a condition also seen in other Mesozoic and Cenozoic anomalodesmatans, demonstrating the recurrence of shell forms in distinct lineages of this interesting group of bivalves.

Studies on the Electrocatalytic Reduction of Hydrogen Peroxide on a Glassy Carbon Electrode Modified With a Ruthenium Oxide Hexacyanoferrate Film

The electrocatalytic reduction of hydrogen peroxide on a glassy carbon (GC) electrode modified with a ruthenium oxide hexacyanoferrate (RuOHCF) was investigated using rotating disc electrode (RDE) voltammetry aiming to improve the performance of the sensor for hydrogen peroxide detection. The influence of parameters such as rotation speed, film thickness and hydrogen peroxide concentration indicated that the rate of the cross-chemical reaction between Ru(II) centres immobilized into the film and hydrogen peroxide controls the overall process. The kinetic regime could be classified as LSk mechanism, according to the diagnostic table proposed by Albery and Hillman, and the kinetic constant of the mediated process was found to be 706 mol(-1) cm(3) s(-1). In the LSk case the reaction layer is located at a finite layer close to the modifier layer/solution interface

Chemiluminescence-based uphill energy conversion

The conversion of red excitation light into blue emission light (uphill energy conversion) using unstable 1,2-dioxetanes is described. The method is based on 1,2-dioxetane formation by red-light sensitized photooxygenation of adequate alkenes and subsequent blue-light emission due to thermal 1,2-dioxetane cleavage. The energy gain resulting from the chemical energy obtained in the transformation of an alkene into two carbonyl compounds transforms a red-light excitation laser beam into a blue-light chemiluminescence emission, producing thereby a formal anti-Stokes shift of 200-250 nm, opening up a whole spectrum of possible applications.

2-(4-Methoxyphenylsulfinyl)cyclohexan-1-one

The cyclohexanone ring in the title compound, C(13)H(16)O(3)S, is in a distorted chair conformation. The intramolecular S center dot center dot center dot O(carbonyl) distance is 2.814 (2) angstrom. Molecules are connected into a two-dimensional array via C-H center dot center dot center dot O contacts involving the carbonyl and sulfinyl O atoms.

2-(2-Nitroanilino)-5,6,7,8-tetrahydro-4H-cyclohepta[b]thiophene-3-carbonitrile

The title compound, C(16)H(15)N(3)O(2)S, was synthesized by the reaction of 2-amino-5,6,7,8-tetrahydro-4H-cyclohepta[b]thiophene-3-carbonitrile and o-fluoronitrobenzene. The thiophene and nitrophenyl rings and amino and carbonitrile groups are coplanar with a maximum deviation of 0.046 (2) angstrom and a dihedral angle of 0.92 (6)degrees between the rings. The cyclohepta ring adopts a chair conformation. Intramolecular N-H center dot center dot center dot O and C-H center dot center dot center dot S interactions occur. In the crystal, the molecules form layers that are linked by pi-pi stacking interactions between the thiophene and benzene rings [centroid-centroid distances = 3.7089 (12) and 3.6170 (12) angstrom].

Meiobenthic communities of seagrass beds (Zostera capricorni) and unvegetated sediments along the coast of New South Wales, Australia

Seagrass beds have higher biomass, abundance, diversity and productivity of benthic organisms than unvegetated sediments. However, to date most studies have analysed only the macrofaunal component and ignored the abundant meiofauna present in seagrass meadows. This study was designed to test if meiobenthic communities, especially the free-living nematodes, differed between seagrass beds and unvegetated sediments. Sediment samples from beds of the eelgrass Zostera capricorni and nearby unvegetated sediments were collected in three estuaries along the coast of New South Wales, Australia. Results showed that sediments below the seagrass were finer, with a higher content of organic material and were less oxygenated than sediments without seagrass. Univariate measures of the fauna (i.e. abundance, diversity and taxa richness of total meiofauna and nematode assemblages) did not differ between vegetated and unvegetated sediments. However multivariate analysis of meiofaunal higher taxa showed significant differences between the two habitats, largely due to the presence and absence of certain taxa. Amphipods, tanaidacea, ostracods, hydrozoans and isopods occurred mainly in unvegetated sediments, while kinorhyncs, polychaetes, gastrotrichs and turbellarians were more abundant in vegetated sediments. Regarding the nematode assemblages, 32.4% of the species were restricted to Z. capricorni and 25% only occurred in unvegetated sediments, this suggests that each habitat is characterized by a particular suite of species. Epistrate feeding nematodes were more abundant in seagrass beds, and it is suggested that they graze on the microphytobenthos which accumulates underneath the seagrass. Most of the genera that characterized these estuarine unvegetated sediments are also commonly found on exposed sandy beaches. This may be explained by the fact that Australian estuaries have very little input of freshwater and experience marine conditions for most of the year. This study demonstrates that the seagrass and unvegetated sediments have discrete meiofaunal communities, with little overlap in species composition. (C) 2010 Elsevier Ltd. All rights reserved.

Cryptic species, life cycles, and the phylogeny of Clytia (Cnidaria: Hydrozoa: Campanulariidae)

Medusae and polyps of Clytia are abundantly found in coastal marine environments and one species in the genus-Clytia hemisphaerica (Linnaeus, 1767)-has become an important experimental model. Yet, only 10 species in the genus have had their life cycle investigated. Most species of Clytia are also poorly described, and detailed life cycle and morphological studies are needed for accurate species-level identifications. Here, we investigated the life cycle of Clytia elsaeoswaldae Stechow, 1914, a species described for the tropical western Atlantic and subsequently considered conspecific to the nearly-cosmopolitan species Clytia gracilis (Sars, 1850) and Clytia hemisphaerica, originally described for the temperate North Atlantic. Based on observations of mature medusae and multiple colonies from southeastern Brazil and the U. S. Virgin Islands (type locality), our results show that C. elsaeoswaldae is morphologically distinct from C. gracilis and C. hemisphaerica. The morphological results are corroborated by a multigene phylogenetic analysis of the genus Clytia, which shows that C. gracilis-like species form a polyphyletic group of several species. These results suggest that the nearly-cosmopolitan distribution attributed to some species of Clytia may be due to the non-recognition of morphologically similar species with more restricted ranges.

Changes in soil organic carbon storage under different agricultural management systems in the Southwest Amazon Region of Brazil

The Cerrado and Amazon regions of Brazil are probably the largest agricultural frontier of the world, and Could be a sink or source for C depending on the net effect of land use change and subsequent management on soil organic C pools. We evaluated the effects of agricultural management systems on soil organic C (SOC) stocks in the Brazilian states of Rondonia and Mato Grosso, and derived regional specific factors for soil C stock change associated with different management systems. We used 50 observations (data points) in this study, including 42 dealing with annual cropping practices and 8 dealing with perennial cropping, and analyzed the data in linear mixed-effect models. No tillage (NT) systems in Cerrado areas increased SOC Storage by 1.08 +/- 0.06 relative to SOC stocks under native conditions, while SOC storage increased by a modest factor of 1.01 +/- 0.17 in Cerradao and Amazon Forest conditions. Full tillage (FT) had negative effect on SOC storage relative to NT, decreasing SOC stocks by a factor of 0.94 +/- 0.04. but did not significantly reduce SOC stocks relative to native levels when adopted in the Cerrado region. Perennial cropping had a minimal impact on SOC stocks, estimated at a factor Value of 0.98 +/- 0.14, suggesting these systems maintain about 98% of the SOC stock found under native vegetation. The results Suggest that NT adoption may be increasing SOC with land use change from native vegetation to cropland management in the Cerrado region of Brazil. (C) 2009 Elsevier B.V. All rights reserved.

Individual-level diet variation in four species of Brazilian frogs

Many natural populations exploiting a wide range of resources are actually composed of relatively specialized individuals. This interindividual variation is thought to be a consequence of the invasion of `empty` niches in depauperate communities, generally in temperate regions. If individual niches are constrained by functional trade-offs, the expansion of the population niche is only achieved by an increase in interindividual variation, consistent with the `niche variation hypothesis`. According to this hypothesis, we should not expect interindividual variation in species belonging to highly diverse, packed communities. In the present study, we measured the degree of interindividual diet variation in four species of frogs of the highly diverse Brazilian Cerrado, using both gut contents and delta(13)C stable isotopes. We found evidence of significant diet variation in the four species, indicating that this phenomenon is not restricted to depauperate communities in temperate regions. The lack of correlations between the frogs` morphology and diet indicate that trade-offs do not depend on the morphological characters measured here and are probably not biomechanical. The nature of the trade-offs remains unknown, but are likely to be cognitive or physiological. Finally, we found a positive correlation between the population niche width and the degree of diet variation, but a null model showed that this correlation can be generated by individuals sampling randomly from a common set of resources. Therefore, albeit consistent with, our results cannot be taken as evidence in favour of the niche variation hypothesis.

A flow-based analytical procedure for salbutamol determination exploiting chemiluminescence in a liquid-core waveguide

Salbutamol is a bronchodilator whose use is restricted due to its anabolic effects. A flow-based procedure for salbutamol determination based on the inhibition of chemiluminescence of the luminol/hypochlorite system was developed. A flow cell constructed with a liquid-core waveguide was employed to constrain the emitted radiation, minimizing losses during transport to detector. Linear response was observed within 2.5 x 10(-6) and 1.0 x 10(-5) mol L-1 with a detection limit estimated as 1 x 10(-7) mol L-1 at the 99.7% confidence level. The coefficient of variation (n = 20), sampling rate, and luminol consumption per determination were estimated as 2.8%, 164 determinations h(-1), and 50 mu g, respectively. Results for pharmaceutical samples were in agreement with those obtained by reference procedures at the 95% confidence level.

Rare canopy species in communities within the Atlantic Coastal Forest in Rio de Janeiro State, Brazil

Rare species are one of the principal components of the species richness and diversity encountered in Dense Ombrophilous Tropical Forests. This study sought to analyze the rare canopy species within the Atlantic Coastal Forest in Rio de Janeiro State, Brazil. Six different communities were examined: Dense Ombrophilous alluvial Forest; Dense sub-montane Ombrophilous Forest; Dense Montane Ombrophilous in Serra do Mar and Serra da Mantiqueira. In each area the vegetation was sampled within forty 10 x 25 m plots alternately distributed along a linear transect. All trees with DBH (1.3 m above ground level) a parts per thousand yen5 cm were sampled. The canopy was characterized using the allometric relationship between diameter and height, and included all trees with BDH a parts per thousand yen10 cm and height a parts per thousand yen10 m. A total of 64 families, 206 genera, and 542 species were sampled, of which 297 (54.8%) represented rare species (less than one individual per hectare). The percentage of rare species varied from 34 to 50% in each of the different communities sampled. A majority of these rare trees belonged to the Rosidae, and a smaller proportion to the Dilleniidae. It was concluded that there was no apparent pattern to rarity among families, that rarity was probably derived from a number of processes (such as gap formation), and that a great majority of the rare species sampled were consistently rare. This indicates that the restricted geographic distribution and high degree of endemism of many arboreal taxa justifies the conservation of even small fragments of Atlantic Forest.

Facial sensibility of patients with trigeminal neuralgias

Objectives: Idiopathic trigeminal neuralgia (ITN) is an excruciating shock-like paroxysmal pain restricted to the trigeminal area of innervation, with discrete loss of sensibility (thermal, tactile and painful). Trigeminal postherpetic neuralgia (PHN) is a neuropathic pain at the trigeminal territory that persists after Herpes zoster infection, which also is associated to sensorial compromise. The objective of this study was to evaluate the somesthetic facial sensibility (pain, thermal and tactile) and to compare the findings between PHN and ITN. Methods: 18 patients with PHN and 26 patients with ITN were diagnosed by the IASP criteria. They were evaluated with a systematic approach, which included mechanical, thermal (cold and warm) and painful stimuli. Results: We found statistical significance at the ophthalmic branch of PHN in pain (p=0.001), tactile (p=0.002), cold (p=0.016) and warm (p=0.013); in ITN, the maxillary branch had higher threshold with pinpricks (p=0.016) and the mandibular branch had higher tactile threshold. Conclusions: The trigeminal area affected by the disease had the higher sensorial losses (ophthalmic branch in PHN and maxillary/mandibular branches in ITN). PHN patients had losses in large and small fibers; therefore, ITN patients had the losses mostly in large fibers, which support different peripheral neural mechanisms for these neuropathic diseases. (C) 2010 Elsevier B.V. All rights reserved.

Deep weathering and landscape evolution in a tropical plateau

The thick weathering profiles of humid tropical areas are an important, yet generally neglected, source of information on landscape evolution. Six complete profiles of the weathering mantle were sampled by drilling on the three stepped levels of the Campos do Jordao Plateau, on the NW flank of the Continental Rift of Southeastern Brazil. Mineralogical and micromorphological analyses of drill core samples, complemented by geochemical interpretations and by previous data on the upper saprolite, indicate continuity of a general lateritic trend during the entire process of mantle formation. Lateritization phases of different intensity were defined and considered to reflect adjustment to changes in environmental conditions created by the gradual uplift of the plateau to its present position. Older and more superficial materials related to intense lateritic weathering are characterized by allitization with direct formation of gibbsite from silicates, probably related to tropical climates existing immediately before the formation of the continental rift, during the Paleogene, and also before any significant increase in altitude. Monosialitization phase with general kaolinitization and restricted indirect formation of gibbsite from silicates could be associated to less aggressive climates that followed the Neogene (Miocene?) accentuation of uplift rates along the continental rift. The changes produced by uplift in the tropical climate eventually favored the development of a podzolization trend in soils above 1800m. (C) 2011 Elsevier BM. All rights reserved.

Exercise prevents the effects of experimental arthritis on the metabolism and function of immune cells

Active lymphocytes (LY) and macrophages (M Phi) are involved in the pathophysiology of rheumatoid arthritis (RA) Due to its anti-inflammatory effect. physical exercise may be beneficial in RA by acting on the immune system (IS) Thus, female Wistar rats with type II collagen-induced arthritis (CIA) were submitted to swimming training (6 weeks. 5 days/week. 60 min/day) and some biochemical and immune parameters, such as the metabolism of glucose and glutamine and function of LY and M. were evaluated In addition, plasma levels of some hormones and of interleukin-2 (IL-2) were also determined Results demonstrate that CIA increased lymphocyte proliferation (1.9- and 1 7-fold, respectively, in response to concanavalin A (ConA) and lipopolysaccharide (LPS)), as well as macrophage H(2)O(2) production (1 6-fold), in comparison to control Exercise training prevented the activation of immune cells, induced by CIA. and established a pattern of substrate utilization similar to that described as normal for these cells. Exercise also promoted an elevation of plasma levels of corticosterone (22 2%), progesterone (1 7-fold) and IL-2 (2 6-fold) Our data suggest that chronic exercise is able to counterbalance the effects of CIA on cells of the IS. reinforcing the proposal that the benefits of exercise may not be restricted to aerobic capacity and/or strength improvement Copyright (C) 2010 John Wiley & Sons, Ltd