Hydrogen isotopic composition of the Tagish Lake meteorite: comparison with other carbonaceous chondrites

A study into the hydrogen isotopic characteristics of whole rock samples of carbonaceous chondrites and their comparison with a whole rock sample of the Tagish Lake meteorite

Regional muscle features and their association with knee extensors force production at a single joint angle

This study aimed (i) to investigate the role of regional characteristics of the knee extensors muscles (vastus lateralis: VL, vastus intermedius: VI and rectus femoris: RF) in determining maximum-voluntary force (MVF); and (ii) to understand which regional parameter of muscle structure would best predict MVF. Muscle architecture (e.g., pennation angle and fascicle length), muscle volume (Vol), anatomical (ACSA) and physiological cross-sectional-area (PCSA) were measured in the proximal (0-33% of the muscle length), middle (33-66% of the muscle length) and distal (66-100% of the muscle length) portions of each muscle in fifteen healthy males using ultrasound and Magnetic Resonance Imaging (MRI). Knee extensors force was calculated in isometric condition at a single knee joint angle of 90 degrees. Regional ACSA, Vol and PCSA were correlated with MVF production. Regional muscle geometry showed no significant correlations with MVF. Among regions, the middle portion of each muscle was largely correlated with MVF compared to all the other regions (distal and proximal). To understand which regional structural parameter best predicted MVF, a stepwise multiple linear regression was performed. This model showed a significant explanatory power (P < 0.001, R-2 = 0.76, adjusted R-2 = 0.71), including muscle Vol collected in the mid portions of VL and RF. Even if no significant differences were reported between Vol, PCSA and ACSA in determining MVF, our results showed that the RF and VL volume collected in the middle portion of the muscle length are strong determinants of MVF produced by the knee extensors at 90 degrees joint angle

The association between organic matter and clay minerals in carbonaceous chondrites

There is an established relationship between organic matter content and aqueous alteration processes [1,2]. However, the relationship between meteoritic organic matter and individual aqueously generated mineral matrix phases is poorly understood. Meteoritic organic matter is primarily composed of C, H and N and therefore their bulk abundances in chondrites are strongly controlled by the organic matter content. Mössbauer Spectroscopy can characterise the ferric iron bearing matrix minerals associated with aqueous alteration, such as Fe- bearing clays and magnetite. A combination of these two parameters may indicate the presence of any organic-mineral interactions

Approximations of Sobolev norms in Carnot groups

This paper deals with a notion of Sobolev space $W^{1,p}$ introduced by J.Bourgain, H.Brezis and P.Mironescu by means of a seminorm involving local averages of finite differences. This seminorm was subsequently used by A.Ponce to obtain a Poincar\'e-type inequality. The main results that we present are a generalization of these two works to a non-Euclidean setting, namely that of Carnot groups. We show that the seminorm expressd in terms of the intrinsic distance is equivalent to the $L^p$ norm of the intrinsic gradient, and provide a Poincar\'e-type inequality on Carnot groups by means of a constructive approach which relies on one-dimensional estimates. Self-improving properties are also studied for some cases of interest

Tricalcium phosphate endosseous implants in dentistry: ultrastructural findings

β-Tricalcium phosphate magnesium substitued (β-TCMP), consisting of one part small unsintered and one part large sintered granules was placed in upper and lower jaw surgical cavities of monkeys. At light and transmission electron microscope the biopsies taken at 2, 4, 8 and 24 weeks showed that both sintered and unsintered granules were well tolerated by the host tissue and result biodegradable over time.β-TCMP may stimulate the direction of bone growth enhancing osteoblasts activity and new bone deposition in direct contact and in the micropores of the biomaterial. β-TCMP containing Mg ions reabsorbs slowly when in sintered granules form and rapidly as unsintered granules. When it is placed in bone cavities, if bone reabsorption is biologically necessary, the biomaterial can be reabsorbed with bone, while if osteogenesis is required β-TCMP provides a more durable matrix to support new bone growth.Le β-phosphate tricalcique contenant à ions Mg (β-TCMP) et constitué à parts égales de fins granules non frittés et de larges granules frittés, est introduit dans des cavités chirurgicales pratiquées dans les maxillaires supérieurs et inférieurs de singes.Des biopsies pratiquées à 2, 4, 8 et 24 semaines ont été examinées au microscope optique et électronique à transmission.Les granules frittés et non frittés sont bien tolérés par les tissus hôtes et sont biodégradés avec le temps.Les observations histologiques montrent aussi que le β-TCMP peut orienter la direction de la croissance osseuse en stimulant l’activité des ostéoblastes et le dépôt d’os nouveau aussi bien autour des biomatériaux que dans leur micropores. Le β-TCMP contenant les ions Mg est réabsorbé lentement lorsqu’il se présente sous la forme de granules frittés, et rapidement lorsqu’il est sous la forme de granules non frittés.Lorsqu’il est introduit dans les cavités osseuses, si la réabsorption osseuse est biologiquement nécessaire, le biomatériau peut être réabsorbé avec l’os, tandis que si c’est l’ostéogenèse qui est sollicitée, β-TCMP fournit une matrice durable comme support à la croissance d’os nouveau

Remote colorimetric measurements by hyperspectral lidar compared to contact conventional colorimetry

Lidars have many applications in different fields, including the field of Cultural Heritage. The purpose of this study is to evaluate a scanning hyperspectral lidar prototype developed at ENEA Center of Frascati as a useful tool for colorimetric analysis when samples cannot be studied with standard contact instruments. A certified X-Rite Color-checker sample, consisting of 24 colored blocks with a coordinated colorimetric certificate, was analyzed. In order to obtain colorimetric data from the reflectance spectra, the precepts of the Commission de l'Éclairage were followed and an algorithm was developed to calculate the color difference between the certified values of the Color-checker and commercial and non-commercial spectrophotometers and those obtained by the lidar, confirming this latter as a useful tool for remote colorimetry

Postpubertal effects of the rapid maxillary expansion and facial mask versus the removable mandibular retractor for the early treatment of class iii malocclusion: A study on lateral cephalograms

The aim of this study was to compare the efficacy of early treatment of Class III malocclusions with rapid maxillary expansion (RME) and facial mask (FM) versus the removable mandibular retractor (RMR) re-evaluated at a postpubertal observation on lateral cephalograms. All prepubertal patients with Class III malocclusion treated consecutively from 1986 to 2013 by means of RME/FM or RMR were analyzed. Twenty-nine patients treated with RME/FM therapy and 23 patients treated with RMR were selected. Lateral cephalograms were available at 3 time points, before treatment (T1), at the end of active treatment (T2), and at a postpubertal observation (T3). Statistical comparisons were performed with independent sample t tests or Mann–Whitney tests. During the T1–T3 interval, a significantly greater maxillary protraction (SNA +1.5 mm, p = 0.031) and significantly greater improvements in ANB and Wits appraisal (+1.9 degrees, p = 0.002, and +2.2 mm, p = 0.012, respectively) were recorded in the RME/FM group. No statistically significant changes could be found in vertical skeletal measurements. In the dentoalveolar region, the RME/FM group showed a significantly greater correction of the molar relationship (−1.5 mm, p = 0.021). Early treatment of Class III malocclusion with RME/FM protocol in comparison with RMR protocol showed a greater maxillary advancement and greater improvements in sagittal skeletal Class III relationships