Bone microarchitecture in human foetuses

articleBone microarchitecture is receiving increasing attention in theassessment of the biomechanical properties of bone. While it iswell characterized in normal and pathologic human subjects,few quantitative data are available in human fetal development.In this paper, quantitative parameters of bone microarchitecturein developing human bone are reviewed from the literature andsupplemented by new data from the femoral metaphysis of hu-man fetuses. The samples were imaged using synchrotron radi-ation 3D micro-CT and processed using customized analysismethods. This technique provides 3D model independent mor-phometric parameters, anisotropy, connectivity and geometrycharacteristics, as well as information on mineralization.The morphometric parameters obtained on fetal vertebrae andfemurs evidenced a dense trabecular structure as comparedto that of young adults. The histomorphometric and the 3D mi-cro-CT analysis were consistent to show a significant in-crease of trabecular bone volume with gestational age. Tra-becular bone was found isotropic in vertebral bodies andanisotropic in femoral metaphysis, demonstrating a radialgrowth in vertebrae, and a longitudinal spreading out in longbones such as the femurs. Trabecular thickness in the maturebone of vertebral body and femoral metaphysis was around100 μm, which was in agreement with histomorphometric eval-uation. In the femoral metaphysis, three-dimensional analysisconfirmed the thickening of trabeculae with the distance tothe growth plate, and an estimated rate of thickening around 3μm/day previously obtained in histomorphometry. The 3D net-work was highly connected, and our new geometrical analysistechnique showed a strong prevalence of rod structure ascompared to the plate structure in cancellous bone

Subthreshold K+ production in deuteron and alpha induced nuclear reactions

Double differential cross sections have been measured for pi+ and K+ emitted around midraidity in d+A and He+A collisions at a beam kinetic energy of 1.15 GeV/nucleon. The total pi+ yield increases by a factor of about 2 when using an alpha projectile instead of a deuteron whereas the K+ yield increases by a factor of about 4. According to transport calculations, the K+ enhancement depends both on the number of hadron-hadron collisions and on the energy available in those collisions: their center-of-mass energy increases with increasing number of projectile nucleons

\pi N and \eta p deexcitation channels of the N^* and \Delta baryonic resonances between 1470 and 1680 MeV

Two reactions, pp->ppX and pp->p\pi^+X, are used to study the 1.47<M<1.68 GeV baryonic mass range. Three different final states are considered in the invariant masses: N^* or \Delta^+, p\pi^0, and p\eta. The last two channels are defined by software cuts applied to the missing mass of the first reaction. Several narrow structures are extracted with widths \sigma(\Gamma) varying between 3 and 9 MeV. Some structures are observed in one channel but not in others. Such nonobservation may be due either to the spectrometer momenta limits or to the physics (e.g. no such disintegration channel is allowed from the narrow state considered). We tentatively conclude that the broad Particle Data Group (PDG) baryonic resonances N(1520)D13, N(1535)S11, Delta(1600)P33, and N(1675)D15 are collective states built from several narrow and weakly excited resonances, each having a (much) smaller width than the one reported by PDG.Comment: 29 pages, plus 50 (.png) figures Will be published in a slightly reduced size in Phys. Rev.

Comparison of eta and eta' production in the pp -> pp eta(eta') reactions near threshold

The total cross section of the pp -> pp eta' reaction has been measured at two energies near threshold by detecting the final protons in a magnetic spectrometer. The values obtained are about a factor of 70 less than for the corresponding eta production, in good agreement with the predictions of a one-pion-exchange model.Comment: 10 pages, Latex with 3 eps figure

Role of picornaviruses in flu-like illnesses of adults enrolled in an oseltamivir treatment study who had no evidence of influenza virus infection

The primary objective of this study was to determine the role of picornavirus in flu-like episodes (temperature of > or =38.0 degrees C plus one respiratory and one constitutional symptom) among otherwise healthy adults enrolled in a placebo-controlled, double-blind, randomized oseltamivir treatment study. Combined nasal and pharyngeal swabs were collected at baseline for influenza cultures and picornavirus reverse transcription (RT)-PCR. In addition, acute- and convalescent-serum samples were obtained for serological studies of common respiratory pathogens. From a total of 719 subjects enrolled in the clinical trial within 36 h of the onset of symptoms, 475 (66%) had evidence of recent influenza A or B virus infections by means of culture and/or serological testing. Of the 244 remaining patients, 36 (15%) presented a seroconv

An imagined past?: Nomadic narratives in Central Asian archaeology

Nomads, or highly specialized mobile pastoralists, are prominent features in Central Asian archaeology, and they are often depicted in direct conflict with neighboring sedentary peoples. However, new archaeological findings are showing that the people who many scholars have called nomads engaged in a mixed economic system of farming and herding. Additionally, not all of these peoples were as mobile as previously assumed, and current data suggest that a portion of these purported mobile populations remained sedentary for much or all of the year, with localized ecological factors directing economic choices. In this article, we pull together nine complementary lines of evidence from the second through the first millennia BC to illustrate that in eastern Central Asia, a complex economy existed. While many scholars working in Eurasian archaeology now acknowledge how dynamic paleoeconomies were, broader arguments are still tied into assumptions regarding specialized economies. The formation of empires or polities, changes in social orders, greater political hierarchy, craft specialization?notably, advanced metallurgy?mobility and migration, social relations, and exchange have all been central to the often circular arguments made concerning so-called nomads in ancient Central Asia. The new interpretations of mixed and complex economies more effectively situate Central Asia into a broader global study of food production and social complexity.- Geographic Focus of This Discussion - The Nomadic Bias Macrobotanical Data Microbotanical Data Isotope Studies Ethnographic and Ethnohistoric Analogies Sedentary Occupation Structures - Villages and Fortified Sites - Farmsteads (Homesteads) Material Culture Evidence for Economy Nonportable Material Culture Zooarchaeology Written Sources Discussion - Two Millennia of Political Agendas - Arguments Used to Support Nomadic Models Conclusion Comments Repl

Socioeconomic Predictors of Cognition in Ugandan Children: Implications for Community Interventions

Background: Several interventions to improve cognition in at risk children have been suggested. Identification of key variables predicting cognition is necessary to guide these interventions. This study was conducted to identify these variables in Ugandan children and guide such interventions. Methods: A cohort of 89 healthy children (45 females) aged 5 to 12 years old were followed over 24 months and had cognitive tests measuring visual spatial processing, memory, attention and spatial learning administered at baseline, 6 months and 24 months. Nutritional status, child’s educational level, maternal education, socioeconomic status and quality of the home environment were also measured at baseline. A multivariate, longitudinal model was then used to identify predictors of cognition over the 24 months. Results: A higher child’s education level was associated with better memory (p = 0.03), attention (p = 0.005) and spatial learning scores over the 24 months (p = 0.05); higher nutrition scores predicted better visual spatial processing (p = 0.002) and spatial learning scores (p = 0.008); and a higher home environment score predicted a better memory score (p = 0.03). Conclusion: Cognition in Ugandan children is predicted by child’s education, nutritional status and the home environment

SEARCH FOR NARROW ISOVECTOR DIBARYONS CLOSE TO LOW MASSES THRESHOLD

For masses larger than 2 MN + Mπ, narrow peaks in two proton invariant (missing) masses spectra : Mpp (Mx) are now well established. The existence of such narrow peaks is not so unquestionable below 2 MN + Mπ. Tensor analyzing power T20 of the invariant mass Mpp has been studied using the p ([MATH], pp) reaction. Depending on the assumption done for background substraction -a hole or an oscillation may appear at Mpp = 1941 MeV. Additional data are under analysis and will improve the statistics

Near-Threshold Production of omega Mesons in the pp -> pp omega Reaction

The total cross section for omega production in the pp -> pp omega reaction has been measured at five c.m. excess energies from 3.8 to 30 MeV. The energy dependence is easily understood in terms of a strong proton-proton final state interaction combined with a smearing over the width of the state. The ratio of near-threshold phi and omega production is consistent with the predictions of a one-pion-exchange model and the degree of violation of the OZI rule is similar to that found in the pi-p -> n omega/phi reactions.Comment: Report in LaTeX2e. 12 pages with 2 eps figure