Ultrastructure of the Interface between Periodontal Tissues and Titanium Mini-Implants

Objective: To describe the ultrastructure of the interface between periodontal tissues and titanium mini-implants in rat mandibles. Materials and Methods: A titanium mini-implant was placed between the buccal roots of the mandibular first molar of 24 adult rats. After 21, 30, 45, 60, 90, and 120 days of implantation, the mandibular portion was removed and fixed in cacodylate-buffered 2% glutaraldehyde + 2.5% formaldehyde. The material was decalcified and processed for scanning and transmission electron microscopy. Results: Ultrastructural analysis revealed a thin cementum-like layer at longer times after implantation at the areas in which the periodontal ligament was in contact with the implant. Conclusions: The alveolar bone and the periodontal ligament reorganized their constituents around the implant, and a thin cementum-like layer was formed at longer times after implantation at the areas in which the periodontal ligament was in contact with the implant. (Angle Orthod. 2010;80:459-435.)

The metal content of bulge field stars from FLAMES-GIRAFFE spectra - I. Stellar parameters and iron abundances

Aims. We determine the iron distribution function (IDF) for bulge field stars, in three different fields along the Galactic minor axis and at latitudes b = -4 degrees, b = -6 degrees, and b = -12 degrees. A fourth field including NGC 6553 is also included in the discussion. Methods. About 800 bulge field K giants were observed with the GIRAFFE spectrograph of FLAMES@VLT at spectral resolution R similar to 20 000. Several of them were observed again with UVES at R similar to 45 000 to insure the accuracy of the measurements. The LTE abundance analysis yielded stellar parameters and iron abundances that allowed us to construct an IDF for the bulge that, for the first time, is based on high-resolution spectroscopy for each individual star. Results. The IDF derived here is centered on solar metallicity, and extends from [Fe/H] similar to -1.5 to [Fe/H] similar to + 0.5. The distribution is asymmetric, with a sharper cutoff on the high-metallicity side, and it is narrower than previously measured. A variation in the mean metallicity along the bulge minor axis is clearly between b = -4 degrees and b = -6 degrees ([Fe/H] decreasing similar to by 0.6 dex per kpc). The field at b = -12 degrees. is consistent with the presence of a gradient, but its quantification is complicated by the higher disk/bulge fraction in this field. Conclusions. Our findings support a scenario in which both infall and outflow were important during the bulge formation, and then suggest the presence of a radial gradient, which poses some challenges to the scenario in which the bulge would result solely from the vertical heating of the bar.

Alpha element abundances and gradients in the Milky Way bulge from FLAMES-GIRAFFE spectra of 650 K giants

Aims. We present the analysis of the [alpha/Fe] abundance ratios for a large number of stars at several locations in the Milky Way bulge with the aim of constraining its formation scenario. Methods. We obtained FLAMES-GIRAFFE spectra (R = 22 500) at the ESO Very Large Telescope for 650 bulge red giant branch (RGB) stars and performed spectral synthesis to measure Mg, Ca, Ti, and Si abundances. This sample is composed of 474 giant stars observed in 3 fields along the minor axis of the Galactic bulge and at latitudes b = -4 degrees, b = -6 degrees, b = -12 degrees. Another 176 stars belong to a field containing the globular cluster NGC 6553, located at b = -3 degrees and 5 degrees away from the other three fields along the major axis. Stellar parameters and metallicities for these stars were presented in Zoccali et al. (2008, A&A, 486, 177). We have also re-derived stellar parameters and abundances for the sample of thick and thin disk red giants analyzed in Alves-Brito et al. (2010, A&A, 513, A35). Therefore using a homogeneous abundance database for the bulge, thick and thin disk, we have performed a differential analysis minimizing systematic errors, to compare the formation scenarios of these Galactic components. Results. Our results confirm, with large number statistics, the chemical similarity between the Galactic bulge and thick disk, which are both enhanced in alpha elements when compared to the thin disk. In the same context, we analyze [alpha/Fe] vs. [Fe/H] trends across different bulge regions. The most metal rich stars, showing low [alpha/Fe] ratios at b = -4 degrees disappear at higher Galactic latitudes in agreement with the observed metallicity gradient in the bulge. Metal-poor stars ([Fe/H] < -0.2) show a remarkable homogeneity at different bulge locations. Conclusions. We have obtained further constrains for the formation scenario of the Galactic bulge. A metal-poor component chemically indistinguishable from the thick disk hints for a fast and early formation for both the bulge and the thick disk. Such a component shows no variation, neither in abundances nor kinematics, among different bulge regions. A metal-rich component showing low [alpha/Fe] similar to those of the thin disk disappears at larger latitudes. This allows us to trace a component formed through fast early mergers (classical bulge) and a disk/bar component formed on a more extended timescale.

PARALLAXES OF SOUTHERN EXTREMELY COOL OBJECTS. I. TARGETS, PROPER MOTIONS, AND FIRST RESULTS

We present results from the PARallaxes of Southern Extremely Cool objects ( PARSEC) program, an observational program begun in 2007 April to determine parallaxes for 122 L and 28 T southern hemisphere dwarfs using the Wide Field Imager on the ESO 2.2 m telescope. The results presented here include parallaxes of 10 targets from observations over 18 months and a first version proper motion catalog. The proper motions were obtained by combining PARSEC observations astrometrically reduced with respect to the Second US Naval Observatory CCD Astrograph Catalog, and the Two Micron All Sky Survey Point Source Catalog. The resulting median proper motion precision is 5 mas yr(-1) for 195,700 sources. The 140 0.3 deg(2) fields sample the southern hemisphere in an unbiased fashion with the exception of the galactic plane due to the small number of targets in that region. The proper motion distributions are shown to be statistically well behaved. External comparisons are also fully consistent. We will continue to update this catalog until the end of the program, and we plan to improve it including also observations from the GSC2.3 database. We present preliminary parallaxes with a 4.2 mas median precision for 10 brown dwarfs, two of which are within 10 pc. These increase the present number of L dwarfs by 20% with published parallaxes. Of the 10 targets, seven have been previously discussed in the literature: two were thought to be binary, but the PARSEC observations show them to be single; one has been confirmed as a binary companion and another has been found to be part of a binary system, both of which will make good benchmark systems. These results confirm that the foreseen precision of PARSEC can be achieved and that the large field of view will allow us to identify wide binary systems. Observations for the PARSEC program will end in early 2011 providing three to four years of coverage for all targets. The main expected outputs are: more than a 100% increase in the number of L dwarfs with parallaxes, increment in the number of objects per spectral subclass up to L9-in conjunction with published results-to at least 10, and to put sensible limits on the general binary fraction of brown dwarfs. We aim to contribute significantly to the understanding of the faint end of the H-R diagram and of the L/T transition region.

Insights on the Milky Way bulge formation from the correlations between kinematics and metallicity

Context. Two main scenarios for the formation of the Galactic bulge are invoked, the first one through gravitational collapse or hierarchical merging of subclumps, the second through secular evolution of the Galactic disc. Aims. We aim to constrain the formation of the Galactic bulge through studies of the correlation between kinematics and metallicities in Baade's Window (l = 1 degrees, b = -4 degrees) and two other fields along the bulge minor axis (l = 0 degrees, b = -6 degrees and b = -12 degrees). Methods. We combine the radial velocity and the [Fe/H] measurements obtained with FLAMES/GIRAFFE at the VLT with a spectral resolution of R = 20 000, plus for the Baade's Window field the OGLE-II proper motions, and compare these with published N-body simulations of the Galactic bulge. Results. We confirm the presence of two distinct populations in Baade's Window found in Hill et al. (2010, A&A, submitted): the metal-rich population presents bar-like kinematics while the metal-poor population shows kinematics corresponding to an old spheroid or a thick disc. In this context the metallicity gradient along the bulge minor axis observed by Zoccali et al. (2008, A&A, 486, 177), visible also in the kinematics, can be related to a varying mix of these two populations as one moves away from the Galactic plane, alleviating the apparent contradiction between the kinematic evidence of a bar and the existence of a metallicity gradient. Conclusions. We show evidence that the two main scenarios for the bulge formation co-exist within the Milky Way bulge.

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.

Effects of different levels of protein intake and physical training on growth and nutritional status of young rats

This study aimed to investigate the effects of physical training, and different levels of protein intake in the diet, on the growth and nutritional status of growing rats. Newly-weaned Wistar rats (n=48) were distributed into six experimental groups: three of them were subjected to physical swim training (1 h per day. 5 d per week, for 4 wk, after 2 wk of familiarization) and the other three were considered as controls (non-trained). Each pair of groups, trained and non-trained, received diets with a different level of protein in their composition: 14%. 21% or 28%. The animals were euthanized at the end of the training period and the following analyses were performed: proteoglycan synthesis as a biomarker of bone and cartilage growth, IGF-I (insulin-like growth factor-I) assay as a biomarker of growth and nutritional status. total RNA and protein concentration and protein synthesis measured in vivo using a large-dose phenylalanine method. As a main finding, increased dietary protein, combined with physical training, was able to improve neither tissue protein synthesis nor muscle growth. In addition, cartilage and bone growth seem to be deteriorated by the lower and the higher levels of protein intake. Our data allow us to conclude that protein enhancement in the diet, combined with physical exercise, does not stimulate tissue protein synthesis or muscle mass growth. Furthermore, physical training, combined with low protein intake, was not favorable to bone development in growing animals.

Radicicol improves regeneration of skeletal muscle previously damaged by crotoxin in mice

This work investigates the influence of heat shock proteins (HSPs) on necrosis and subsequent skeletal muscle regeneration induced by crotoxin (CTX), the major component of Crotalus durissus terrificus venom. Mice were treated with radicicol, a HSP inductor, followed by an intramuscular injection of CTX into the gastrocnemius muscle. Treated groups were sacrificed 1, 10 and 21 days after CTX injection. Muscle histological sections were stained with toluidine blue and assayed for acid phosphatase or immunostained with either neuronal cell adhesion molecule (NCAM) or neonatal myosin heavy chain (MHCn). Muscle samples were also submitted to Western blotting analysis. The results show that CTX alone and CTX combined with radicicol induced a similar degree of myofiber necrosis. CTX-injured muscles treated with radicicol had increased cross-sectional areas at 10 and 21 days post-lesion compared with untreated CTX-injured muscles. Additionally, radicicol significantly increased the number of NCAM-positive satellite cells in the gastrocnemius at one day post-CTX injury. CTX-injured Muscles treated with radicicol contained more MHCn-positive regenerating myofibers compared with untreated CTX-injured muscles. These results suggest that HSPs contribute to the regeneration of myofibers damaged by CTX. Additionally, further studies should investigate the potential therapeutic effects of radicicol in skeletal muscles affected by Crotalus venom. (C) 2008 Elsevier Ltd. All rights reserved.

Robot measuring form errors

This work presents an automated system for the measurement of form errors of mechanical components using an industrial robot. A three-probe error separation technique was employed to allow decoupling between the measured form error and errors introduced by the robotic system. A mathematical model of the measuring system was developed to provide inspection results by means of the solution of a system of linear equations. A new self-calibration procedure, which employs redundant data from several runs, minimizes the influence of probes zero-adjustment on the final result. Experimental tests applied to the measurement of straightness errors of mechanical components were accomplished and demonstrated the effectiveness of the employed methodology. (C) 2007 Elsevier Ltd. All rights reserved.

Hybrid Reinforcement of Sisal and Polypropylene Fibers in Cement-Based Composites

Several studies using vegetable fibers as the exclusive reinforcement in fiber-cement composites have shown acceptable mechanical performance at the first ages. However, after the exposure to accelerated aging tests, these composites have shown significant reduction in the toughness or increase in embrittlement. This was mainly attributed to the improved fiber-matrix adhesion and fiber mineralization after aging process. The objective of the present research was to evaluate composites produced by the slurry dewatering technique followed by pressing and air curing, reinforced with combinations of polypropylene fibers and sisal kraft pulp at different pulp freeness. The physical properties, mechanical performance, and microstructural characteristics of the composites were evaluated before and after accelerated and natural aging. Results showed the great contribution of pulp refinement on the improvement of the mechanical strength in the composites. Higher intensities of refinement resulted in higher modulus of rupture for the composites with hybrid reinforcement after accelerated and natural aging. The more compact microstructure was due to the improved packing of the mineral particles with refined sisal pulp. The toughness of the composites after aging was maintained in relation to the composites at 28 days of cure.

Evaluation of Adaptive Genetic Algorithm to Environmental Modeling of Peponapis and Cucurbita

This paper presents a free software tool that supports the next-generation Mobile Communications, through the automatic generation of models of components and electronic devices based on neural networks. This tool enables the creation, training, validation and simulation of the model directly from measurements made on devices of interest, using an interface totally oriented to non-experts in neural models. The resulting model can be exported automatically to a traditional circuit simulator to test different scenarios.

Prior and concomitant dehydroepiandrosterone treatment affects immunologic response of cultured macrophages infected with Trypanosoma cruzi in vitro?

DHEA, a steroid hormone synthesized from cholesterol by cells of the adrenal cortex, plays an essential role in enhancing the host`s resistance to different experimental infections. Receptors for this hormone can be found in distinct immune cells (especially macrophages) that are known to be the first line defense against Trypanosoma cruzi infection. These cells operate through an indirect pathway releasing nitric oxide (NO) and cytokines such TNF-alpha and IL-12 which in turn trigger an enhancement of natural killer cells and lymphocytes which finally secrete pro and anti-inflammatory cytokines. The effects of pre- and post-infection DHEA treatment on production of IL-12, TNF alpha and NO were evaluated. T. cruzi infected macrophages post treated with DHEA displayed enhanced concentrations of TNF-alpha, IL-12 and NO. Probably, the mechanisms that induced the production of cytokines by infected cells are more efficient when the immune system has been stimulated first by parasite invasion, suggesting that the protective role of DHEA is greater when administered post infection. (C) 2011 Elsevier B.V. All rights reserved.

Structural analysis and molecular model of a self-incompatibility RNase from wild tomato

Self-incompatibility RNases (S-RNases) are an allelic series of style glycoproteins associated with rejection of self-pollen in solanaceous plants. The nucleotide sequences of S-RNase alleles from several genera have been determined, but the structure of the gene products has only been described for those from Nicotiana alata. We report on the N-glycan structures and the disulfide bonding of the S-3-RNase from wild tomato (Lycopersicon peruvianum) and use this and other information to construct a model of this molecule. The S-3-RNase has a single N-glycosylation site (Asn-28) to which one of three N-glycans is attached. S-3-RNase has seven Cys residues; six are involved in disulfide linkages (Cys-16-Cys-21, Cys-46-Cys-91, and Cys-166-Cys-177), and one has a free thiol group (Cys-150). The disulfide-bonding pattern is consistent with that observed in RNase Rh, a related RNase for which radiographic-crystallographic information is available. A molecular model of the S-3-RNase shows that four of the most variable regions of the S-RNases are clustered on one surface of the molecule. This is discussed in the context of recent experiments that set out to determine the regions of the S-RNase important for recognition during the self-incompatibility response.

Extended delayed recall of AVLT word lists: Effects of age and sex on adult performance

An extension of a previous study of age and sex effects on verbal recall (Geffen, Moar, O'Hanlon, lark, & Geffen, 1990) examined forgetting of words over extended delays. The AVLT was administered to 201 normal adults (99 males, 102 females) ranging in age between 20 and 59 years. Recall was tested at intervals of 30 minutes, 24 hours, and 7 days after acquisition. Testing of the latter two intervals was conducted by telephone (Experiment 1, N = 177). After 30 minutes there was no significant loss of the 10 to 11 words retained from five acquisition trials. However, an overall mean of about one word was forgotten after 1 day and a further word after 7 days. The oldest age group (50-59 years) acquired fewer words and forgot more words than the younger groups. Females of all age groups performed slightly better than males at acquisition, at retention, and at recall after longer delays. A second experiment showed that telephone testing at the longer delay intervals was equivalent to testing face to face. These results extend the use of the AVLT by assessing memory decay beyond the immediate testing period. Telephone follow-up is a convenient and economical method of testing delayed recall.

Catecholamine release in heat-stressed Antarctic fish causes proton extrusion by the red cells

Two species of Antarctic fish were stressed by moving them from seawater at -1 degrees C to seawater at 10 degrees C and holding them for a period of 10 min. The active cryopelagic species Pagothenia borchgrevinki maintained heart rate while in the benthic species Trematomus bernacchii there was an increase in heart rate. Blood pressure did not change in either species. Both species released catecholamines into the circulation as a consequence of the stress. P. borchgrevinki released the greater amounts, having mean plasma concentrations of 177 +/- 54 nmol.l(-1) noradrenaline and 263 +/- 131 nmol.l(-1) adrenaline at 10 min. Pla.sma noradrenaline concentrations rose to 47 +/- 14 nmol.l(-1) and adrenaline to 73 +/- 28 nmol.l(-1) in T. bernacchii. Blood from P. borchgrevinki was tonometered in the presence of isoprenaline. A fall in extracellular pH suggests the presence of a Na+/H+ antiporter on the red cell membrane, the first demonstration of this in an Antarctic fish. Treatment with the beta-adrenergic antagonist drug sotalol inhibited swelling of red blood cells taken from temperature-stressed P. borchgrevinki, suggesting that the antiporter responds to endogenous catecholamines.