A Multi-Membership Catalogue for 1876 Open Clusters using UCAC4 data

The main objective of this work is to determine the cluster members of 1876 open clusters, using positions and proper motions of the astrometric catalogue UCAC4. For this purpose we apply three different methods, all them based on a Bayesian approach, but with different formulations: a purely parametric method, another completely non-parametric algorithm, and a third, recently developed by Sampedro & Alfaro, using both formulations at different steps of the whole process. The first and second statistical moments of the members phase-space subspace, obtained after applying the three methods, are compared for every cluster. Although, on average, the three methods yield similar results, specific differences between them, as well as for some particular clusters, are also present. The comparison with other published catalogues shows good agreement. We have also estimated for the first time the mean proper motion for a sample of 18 clusters. The results are organized in a single catalogue formed by two main files, one with the most relevant information for each cluster, partially including that in UCAC4, and the other showing the individual membership probabilities for each star in the cluster area. The final catalogue, with an interface design that enables an easy interaction with the user, is available in electronic format at SSG-IAA (http://ssg.iaa.es/en/content/sampedro-cluster-catalog) website.Comment: Accepted for publication in MNRAS. 9 pages, 3 figures, 6 table

Direct observations of the Antarctic Slope Current transport at 113°E

Author Posting. © American Geophysical Union, 2016. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research: Oceans 121 (2016): 7390–7407, doi:10.1002/2015JC011594.The Antarctic Slope Current (ASC), defined here as the region of westward flow along the continental slope off Antarctica, forms the southern limb of the subpolar gyres. It regulates the exchange of water across the shelf break and provides a path for interbasin westward transport. Despite its significance, the ASC remains largely unobserved around most of the Antarctic continent. Here we present direct velocity observations from a 17 month current meter moored array deployed across the continental slope between the 1000 and the 4200 m isobaths, in the southeastern Indian Ocean near 113°E. The observed time-mean flow consists of a surface-intensified jet associated with the Antarctic Slope Front (ASF) and a broader bottom-intensified westward flow that extends out to approximately the 4000 m isobath and is strongest along the upper slope. The time-mean transport of the ASC is −29.2 Sv. Fluctuations in the transport are large, typically exceeding the mean by a factor of 2. They are mainly due to changes in the northward extent of the current over the lower slope. However, seasonal changes in the wind also drive variations in the transport of the ASF and the flow in the upper slope. Both mean and variability are largely barotropic, thus invisible to traditional geostrophic methodsM.S.M. and the current meter array were supported by the National Science Foundation grant 0727045 ‘‘Measuring Westward Recirculation in the Subpolar Gyre of the Southeastern Indian Ocean.’’ B.P.M. and S.R.R. were supported by the Cooperative Research Centre program of the Australian Government, through the Antarctic Climate and Ecosystems Cooperative Research Centre. S.R.R. was also supported by the Australian Government Department of the Environment, the Bureau of Meteorology and CSIRO through the Australian Climate Change Science Program.2017-04-1

Endothelial Cell Thrombin Receptors and PAR-2 TWO PROTEASE-ACTIVATED RECEPTORS LOCATED IN A SINGLE CELLULAR ENVIRONMENT

Human endothelial cells express thrombin receptors and PAR-2, the two known members of the family of protease-activated G protein-coupled receptors. Because previous studies have shown that the biology of the human thrombin receptor varies according to the cell in which it is expressed, we have taken advantage of the presence of both receptors in endothelial cells to examine the enabling and disabling interactions with candidate proteases likely to be encountered in and around the vascular space to compare the responses elicited by the two receptors when they are present in the same cell and to compare the mechanisms of thrombin receptor and PAR-2 clearance and replacement in a common cellular environment. Of the proteases that were tested, only trypsin activated both receptors. Cathepsin G, which disables thrombin receptors, had no effect on PAR-2, while urokinase, kallikrein, and coagulation factors IXa, Xa, XIa, and XIIa neither substantially activated nor noticeably disabled either receptor. Like thrombin receptors, activation of PAR-2 caused pertussis toxin-sensitive phospholipase C activation as well as activation of phospholipase A2, leading to the release of PGI2. Concurrent activation of both receptors caused a greater response than activation of either alone. It also abolished a subsequent response to the PAR-2 agonist peptide, SLIGRL, while only partially inhibiting the response to the agonist peptide, SFLLRN, which activates both receptors. After proteolytic or nonproteolytic activation, PAR-2, like thrombin receptors, was cleared from the endothelial cell surface and then rapidly replaced with new receptors by a process that does not require protein synthesis. Selective activation of either receptor had no effect on the clearance of the other. These results suggest that the expression of both thrombin receptors and PAR-2 on endothelial cells serves more to extend the range of proteases to which the cells can respond than it does to extend the range of potential responses. The results also show that proteases that can disable these receptors can distinguish between them, just as do most of the proteases that activate them. Finally, the residual response to SFLLRN after activation of thrombin receptors and PAR-2 raises the possibility that a third, as yet unidentified member of this family is expressed on endothelial cells, one that is activated by neither thrombin nor trypsin

Shear-melting of a hexagonal columnar crystal by proliferation of dislocations

A hexagonal columnar crystal undergoes a shear-melting transition above a critical shear rate or stress. We combine the analysis of the shear-thinning regime below the melting with that of synchrotron X-ray scattering data under shear and propose the melting to be due to a proliferation of dislocations, whose density is determined by both techniques to vary as a power law of the shear rate with a 2/3 exponent, as expected for a creep model of crystalline solids. Moreover, our data suggest the existence under shear of a line hexatic phase, between the columnar crystal and the liquid phase

Electrophoretic deposition of Sr-containing mesoporous bioactive glass particles produced by spray-drying

Introduction Mesoporous bioactive glasses (MBGs) are gaining increasing interest in the biomedical field thanks to their exceptional textural characteristics (high surface area, high pore volume and highly ordered mesoporosity). These properties lead to an improved apatite kinetics formation, which allow these glasses to be successfully applied in bone tissue regeneration [1]. In this work we adopted an aerosol-based spray drying process in order to have high control and reproducibility over the morphology of particles. In order to increase their regenerative potential, the particles have been doped with strontium, element known for its osteogenic and bone antiresorptive properties [2]. Later the particles have been deposed by electrophoretic deposition (EPD) on glass-ceramic scaffolds fabricated by the polymer sponge replication method. EPD is a versatile technique which allows an easy control of the thickness of the deposited film through simple adjustment of the applied voltage and the deposition time. The scaffolds, based on a quaternary silicate glass (SCNA, SiO2–CaO–Na2O–Al2O3 oxide system), have good mechanical properties but low bioactivity [3]. Thanks to MBG particle deposition, they acquire a pronounced bioactive behaviour, thus becoming an excellent solution for bone tissue regeneration. Results and Discussion MBGs synthesized with the aerosol-based spray-drying process have a basic composition on the SiO2-CaO system and have been doped with the 1% molar of strontium (SD_Sr1). FESEM image of particles shows micro-sized spherical particles, with size mostly ranging between 500 nm and 5 µm. N2 adsorption analysis gives back a high specific surface area value, 160 m2/g, and a pore size distribution between 5 and 9 nm, which confirms the mesoporosity of the sample. Strontium incorporation inside the binary composition does not modify the bioactive behaviour of the glass: after 14 days in SBF nanoparticles are completely covered by a layer of hydroxyapatite.The EDS quantitative analysis shows that the amount of strontium effectively incorporated in the microparticles was 70% of the theoretical one, probably because of the high dimension of the ion which hinders its entrance into the glass network. Nevertheless, most of the Sr incorporated has been released after 14 days of immersion in SBF, as the coupled plasma-atomic emission spectrometry (ICP-AES) reveals. On the basis of literature data, the released concentrations are suitable for inducing osteogenesis [4]. EPD has been performed in ethanol, applying a voltage of 120 V for 5 minutes. The scaffolds, being not conductive, have been suspended between two stainless steel electrodes through a clamp. A dispersant (TEA, triethanolamine) has been used to keep the particles in suspension during the whole deposition time. The deposited layer was abundant but not uniform on the scaffold surface. After immersion for 7 days in SBF, hydroxyapatite formation has been observed on the surface of the microparticles deposited on the scaffold struts. This demonstrates that MBGs not only maintain their bioactivity after deposition but also transfer this property to scaffolds. Conclusions MBGs synthetized with aerosol-based spray-drying process and doped with strontium have excellent textural properties and a bioactive behaviour. After electrophoretic deposition, they maintain these properties and consequently they improve the bioactivity of SCNA scaffolds, which initially are almost biologically inert. In this way we demonstrate that it is possible to obtain a successful construct for bone tissue engineering with both excellent regenerative and mechanical properties

A performance prediction model for pumps as turbines (PATs)

In recent years, the interest towards the use of pumps operating as turbines (PATs) for the generation of electrical energy has increased, due to the low cost of implementation and maintenance. The main issue that inhibits a wider use of PATs is the lack of corresponding characteristic curves, because manufacturers usually provide only the pump-mode performance characteristics. In the PAT selection phase, the lack of turbine-mode characteristic curves forces users to expend expensive and time-consuming efforts in laboratory testing. In the technical literature, numerous methods are available for the prediction of PAT turbine-mode performance based on the pump-mode characteristics, but these models are usually calibrated making use of few devices. To overcome this limit, a performance database called Redawn is presented and the data collected are used to calibrate novel PAT performance models

Assessing Driver Fitness to Participate in FHWA Field Experimentation at Night

A Driving Fitness Form was developed to ensure that drivers areready to participate in field driving experiments at night. The form was tested in afield experiment conducted in Delta, Pennsylvania, during August 2004. The fieldexperiment was part of a cooperative research program conducted by the FederalHighway Administration and the Pennsylvania Department of Transportation.Sixteen research participants drove a curvy stretch of rural two-lane highway eachnight for 8 nights with different pavement markings and markers on the roadway.Partly due to the Driving Fitness Form, the experiment was completedsuccessfully by all participants without any incidents or crashes. The DrivingFitness Form performed well, and summary data were collected on the sample of16 drivers

Finitness of the basic intersection cohomology of a Killing foliation

We prove that the basic intersection cohomology ${I H}^{^{*}}_{_{\bar{p}}}{(M/\mathcal{F})},$ where $\mathcal{F}$ is the singular foliation determined by an isometric action of a Lie group $G$ on the compact manifold $M$, is finite dimensional

Photometric type Ia supernova surveys in narrow band filters

We study the characteristics of a narrow band type Ia supernova survey through simulations based on the upcoming Javalambre Physics of the accelerating universe Astrophysical Survey (J-PAS). This unique survey has the capabilities of obtaining distances, redshifts, and the SN type from a single experiment thereby circumventing the challenges faced by the resource-intensive spectroscopic follow-up observations. We analyse the flux measurements signal-to-noise ratio and bias, the supernova typing performance, the ability to recover light curve parameters given by the SALT2 model, the photometric redshift precision from type Ia supernova light curves and the effects of systematic errors on the data. We show that such a survey is not only feasible but may yield large type Ia supernova samples (up to 250 supernovae at $z<0.5$ per month of search) with low core collapse contamination ($\sim 1.5$ per cent), good precision on the SALT2 parameters (average $\sigma_{m_B}=0.063$, $\sigma_{x_1}=0.47$ and $\sigma_c=0.040$) and on the distance modulus (average $\sigma_{\mu}=0.16$, assuming an intrinsic scatter $\sigma_{\mathrm{int}}=0.14$), with identified systematic uncertainties $\sigma_{\mathrm{sys}}\lesssim 0.10 \sigma_{\mathrm{stat}}$. Moreover, the filters are narrow enough to detect most spectral features and obtain excellent photometric redshift precision of $\sigma_z=0.005$, apart from $\sim$ 2 per cent of outliers. We also present a few strategies for optimising the survey's outcome. Together with the detailed host galaxy information, narrow band surveys can be very valuable for the study of supernova rates, spectral feature relations, intrinsic colour variations and correlations between supernova and host galaxy properties, all of which are important information for supernova cosmological applications.Comment: 20 pages, 12 tables and 26 figures. Version accepted by MNRAS, with results slightly different from previous on