On the shape of the mass-function of dense clumps in the Hi-GAL fields. II. Using Bayesian inference to study the clump mass function

Context. Stars form in dense, dusty clumps of molecular clouds, but little is known about their origin, their evolution and their detailed physical properties. In particular, the relationship between the mass distribution of these clumps (also known as the "clump mass function", or CMF) and the stellar initial mass function (IMF), is still poorly understood. Aims. In order to better understand how the CMF evolve toward the IMF, and to discern the "true" shape of the CMF, large samples of bona-fide pre- and proto-stellar clumps are required. Two such datasets obtained from the Herschel infrared GALactic Plane Survey (Hi-GAL) have been described in paper I. Robust statistical methods are needed in order to infer the parameters describing the models used to fit the CMF, and to compare the competing models themselves. Methods. In this paper we apply Bayesian inference to the analysis of the CMF of the two regions discussed in Paper I. First, we determine the Bayesian posterior probability distribution for each of the fitted parameters. Then, we carry out a quantitative comparison of the models used to fit the CMF. Results. We have compared the results from several methods implementing Bayesian inference, and we have also analyzed the impact of the choice of priors and the influence of various constraints on the statistical conclusions for the preferred values of the parameters. We find that both parameter estimation and model comparison depend on the choice of parameter priors. Conclusions. Our results confirm our earlier conclusion that the CMFs of the two Hi-GAL regions studied here have very similar shapes but different mass scales. Furthermore, the lognormal model appears to better describe the CMF measured in the two Hi-GAL regions studied here. However, this preliminary conclusion is dependent on the choice of parameters priors.Comment: Submitted for publication to A&A on November 12, 2013. This paper contains 11 pages and 7 figure

Equivalent layered models for functionally graded plates

Functionally graded plates whose material properties vary continuously through the thickness are modelled as exactly equivalent plates composed of up to four isotropic layers. Separate models are derived for analysis using classical plate theory, first-order and higher-order shear deformation theory. For cases where Poisson’s ratio varies through the thickness, the integrations required to obtain the membrane, coupling and out-of-plane stiffness matrices are performed accurately using a series solution. The model is verified by comparison with well converged solutions from approximate models in which the plate is divided into many isotropic layers. Critical buckling loads and undamped natural frequencies are found for a range of illustrative examples

Assessment of cyst content using mean gray value for discriminating endometrioma from other unilocular cysts in premenopausal women

Objective To assess whether the analysis of cyst content using mean gray value (MGV) can discriminate ovarian endometriomas from other unilocular ovarian cysts in premenopausal women. Methods Stored three-dimensional (3D) volumes from 54 unilocular ovarian cysts diagnosed in 50 premenopausal women (mean age, 37 (range, 22–50) years) were analyzed to calculate the MGV from cyst content. Cysts with solid components or septations were excluded. MGV was calculated in all cases with the Virtual Organ Computer-aided AnaLysisTM technique. The Bmode presumptive diagnosis based on the examiner’s subjective impression was also recorded. Results Sixteen of the cysts resolved spontaneously and were given a final clinical diagnosis of hemorrhagic functional cyst, while 38 cysts were removed surgically (diagnosed histologically as seven simple cysts, three hemorrhagic cysts, 20 endometriomas, five mucinous cysts and three paraovarian cysts). B-mode diagnoses were as follows: seven simple cysts, 18 hemorrhagic cysts, 24 endometriomas, three mucinous cysts and two paraovarian cysts. MGV was significantly higher in ovarian endometrioma when compared with all other kinds of cyst. The receiver–operating characteristics curve showed that using an MGV cut-off ≥15.560 had a sensitivity of 85% and a specificity of 76.5% for diagnosing ovarian endometrioma (area under the curve, 0.831; 95% CI, 0.718–0.944). These figures were similar to those for B-mode diagnosis (sensitivity, 90%; specificity, 82%) (McNemar test, P = 1.000). Combining B-mode and MGV gave a sensitivity of 80% and a specificity of 91%. Conclusion Cyst content MGV is higher in ovarian endometrioma than it is in other unilocular ovarian cysts. The diagnostic performance of MGV is similar to that of the examiner’s subjective impression. The combination of both criteria achieves the highest specificit

Phytochemical characterization of Tabernanthe iboga root bark and its effects on dysfunctional metabolism and cognitive performance in high-fat-fed C57BL/6J mice

Preparations of the root bark of Tabernanthe iboga have long been used in Central and West African traditional medicine to combat fatigue, as a neuro-stimulant in rituals, and for treatment of diabetes. The principal alkaloid of T. iboga, ibogaine, has attracted attention in many countries around the world for providing relief for opioid craving in drug addicts. Using a plant metabolomics approach, we detected five phenolic compounds, including 3- O-caffeoylquinic acid, and 30 alkaloids, seven of which were previously reported from T. iboga root bark. Following a report that iboga extracts contain insulinotropic agents, we aimed to determine the potential alleviating effects of the water extract of iboga root bark on high-fat diet (HFD)-induced hyperglycemia as well as its effects on cognitive function in male C57BL/6J mice. Feeding a HFD to mice for 10 weeks produced manifestations of metabolic syndrome such as increased body weight and increased plasma levels of glucose, triacylglycerols, total cholesterol, LDL-cholesterol, insulin, leptin, and pro-inflammatory mediators (IL-6, MCP-1, ICAM-1), as compared to mice fed a low-fat diet (LFD). Supplementation of HFD with iboga extract at ibogaine doses of 0.83 (low) and 2.07 (high) mg/kg/day did not improve these HFD-induced metabolic effects except for a reduction of plasma MCP-1 in the low dose group, indicative of an anti-inflammatory effect. When the HFD mice were tested in the water maze, the high-dose iboga extract caused hippocampus-dependent impairments in spatial learning and memory, as compared to mice receiving only a HFD.Peer reviewedFinal Published versio

Assessing myometrial infiltration by endometrial cancer: uterine virtual navigation with three-dimensional US

To describe and analyze the diagnostic performance of uterine virtual navigation with three-dimensional (3D) ultrasonography (US) for the assessment of the depth of myometrial infiltration by endometrial cancer. MATERIALS AND METHODS: Institutional review board approval was obtained; patients gave oral informed consent. Women with endometrial cancer were evaluated by using 3D US prior to surgical staging. A 3D volume of the whole uterus was obtained and analyzed by using software. Virtual navigation through three orthogonal planes was performed to identify the shortest myometrial tumor-free distance to serosa (TDS) by analyzing the lateral, anterior, posterior, and fundal portions of the myometrium. Myometrial infiltration was also assessed by subjective impression of an examiner. Histologic findings of myometrial infiltration and TDS measured by a pathologist were used as the reference standard. A receiver operating characteristic curve was plotted to identify the best cutoff for TDS for identifying myometrial infiltration of 50% or more. RESULTS: Ninety-six women (mean age, 61.8 years; range, 31-86 years) with endometrial cancer were included in the study. At histologic analysis, myometrial invasion was found to be less than 50% in 69 (72%) cases and 50% or more in 27 (28%) cases. TDS measured with US was positively correlated with histologically measured TDS (r = 0.649; 95% confidence interval: 0.52, 0.76). The best cutoff for US-measured TDS was 9.0 mm (sensitivity, 100%; specificity, 61%; negative predictive value, 100%; positive predictive value, 50%). Subjective impression had a sensitivity of 92.6%, a specificity of 82.3%, a negative predictive value of 96.6%, and a positive predictive value of 67.7%. CONCLUSION: Uterine virtual navigation with 3D US is a reliable method for the assessment of myometrial infiltration in patients with endometrial cancer

Microstructural characterization of Y₂O₃ ODS-Fe-Cr model alloys

Proceedings of the: Thirteenth International Conference on Fusion Reactor Materials. Nice (France), 10-14/12/2007.Two Fe-12 wt% Cr alloys, one containing 0.4 wt% Y₂O₃ and the other Y₂O₃ free, have been produced by mechanical alloying followed by hot isostatic pressing. These oxide dispersion strengthened and reference alloys were characterized both in the as-HIPed state and after tempering by transmission electron microscopy and atom-probe tomography. The as-HIPed alloys exhibited the characteristic microstructure of lath martensite and contained a high density of dislocations. Small voids with sizes <10 nm were also observed. Both alloys also contained M₃C and M₂₃C₆ carbides (M = Cr, Fe) probably as a result of C ingress during milling. After tempering at 1023 K for 4 h the microstructures had partially recovered. In the recovered regions, martensite laths were replaced by equiaxed grains in which M₂₃C₆ carbides decorated the grain boundaries. In the ODS alloy nanoparticles containing Y were commonly observed within grains, although they were also present at grain boundaries and adjacent to large carbides.This research has been supported by FP6 Euratom Research and Training Programme on Nuclear Energy. The financial support from the Comunidad de Madrid, through the program ESTRUMAT CM,Grant S 0505/MAT/0077.Publicad

Brazil and the framework convention on tobacco control: global health diplomacy as soft power.

As part of the PLoS Medicine series on Global Health Diplomacy, Kelley Lee and colleagues provide a case study of Brazil's growing influence in international relations and global health, using as an example that country's role and use of “soft power” in the negotiation of the Framework Convention on Tobacco Control

TRY plant trait database - enhanced coverage and open access

Plant traits-the morphological, anatomical, physiological, biochemical and phenological characteristics of plants-determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait-based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits-almost complete coverage for 'plant growth form'. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait-environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives