A ringed pole-on outflow from DO Tauri revealed by ALMA

We present new ALMA Band 6 observations including the CO (2-1) line and 1.3 mmcontinuum emission from the surroundings of the young stellar object DO Tauri. TheALMA CO molecular data show three different series of rings at different radial ve-locities. These rings have radii around 220 au and 800 au. We make individual fits tothe rings and note that their centers are aligned with DO Tauri and its optical high-velocity jet. In addition, we notice that the velocity of these structures increases withthe separation from the young star. We discuss the data under the hypothesis that therings represent velocity cuts through three outflowing shells that are possibly drivenby a wide-angle wind, dragging the environment material along a direction close to theline of sight (i= 19◦). We estimate the dynamical ages, the mass, the momentum andthe energy of each individual outflow shell and those of the whole outflow. The resultsare in agreement with those found in outflows from Class II sources. We make a roughestimate for the size of the jet/wind launching region, which needs to be of.15 au.We report the physical characteristics of DO Tauri?s disk continuum emission (almostface-on and with a projected major axis in the north-south direction) and its velocitygradient orientation (north-south), indicative of disk rotation for a 1-2 Mcentral star.Finally we show an HST [SII] image of the optical jet and report a measurement of itsorientation in the plane of the sky.Fil: Fernandez Lopez, Manuel. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Argentino de Radioastronomía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Argentino de Radioastronomía; ArgentinaFil: Zapata Gonzalez, Luis Alberto. Universidad Nacional Autonoma de Mexico. Instituto de Astronomia; MéxicoFil: Rodríguez, Luis F.. Universidad Nacional Autonoma de Mexico. Instituto de Astronomia; MéxicoFil: Vazzano, María Mercedes. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Argentino de Radioastronomía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Argentino de Radioastronomía; ArgentinaFil: Guzman, Andrés E.. National Astronomical Observatory Of Japan; JapónFil: López, Rosario. Universidad Autónoma de Barcelona. Facultad de Física. Departamento Astronomía y Meteorología; Españ

Microstructure Evolution During Powder Compaction

The process of powder compaction consists of the synthesis of loose powders into a solid material. The applications of compaction of granular systems extend to pharmaceuticals, detergents, food, ceramic and metallurgical processes. It is indispensable to have a thorough understanding of the behavior of confined granular systems during compaction because the performance of the final desired product is related to the microstructural features that develop during the compaction process. To have a more realistic description of the compaction, it is also important to include the packing process of granular systems. However, there are different particle packing algorithms that account for the particle filling process. The Discrete Element Method (DEM) had been used to obtain a dynamic solution to this problem but requires high computational power. As an alternative to the computationally expensive DEM approach, a static based algorithm has recently been developed for the modelling and simulation of the particle packing process. The algorithm allows for the modelling of the packing process by placing spheres inside different shapes and sizes of containers. In this study, we present a new version of the nanoHUB Powder Compaction tool. It currently simulates the microstructure evolution of monodisperse, compressible granular systems up to high relative densities. The tool also models the plastic and elastic deformation of single particles described by different contact mechanics models. The new features use a general particle packing algorithm and thus allow the user to choose a particle size distribution in a specified range for the mean, standard deviation and number of particles to fill the die. The information is passed to the solver that in turn simulates the compaction in Purdue’s high-performance computer cluster

Monitoring falls in gastric cancer mortality in Europe

We have considered trends in age-standardized mortality from gastric cancer in 25 individual European countries, as well as in the European Union (EU) as a whole, in six selected central-eastern European countries and in the Russian Federation over the period 1950-1999. Steady and persisting falls in rates were observed, and the fall between 1980 and 1999 was ∼50% in the EU, 45% in eastern Europe and 40% in Russia. However, the declines were greater in Russia and eastern Europe, since rates were much higher, in absolute terms. Joinpoint regression analysis indicated that the falls were proportionally greater in the last decade for men (-3.83% per year in the EU) and in the last 25 years for women (-3.67% per year in the EU) than in previous calendar years. Moreover, steady declines in gastric cancer mortality were observed in the middle-aged and the young population as well, suggesting that they are likely to persist in the near future. In terms of number of deaths avoided, however, the impact of the decline in gastric cancer mortality will be smaller, particularly in the E

Clustering Improves the Goemans–Williamson Approximation for the Max-Cut Problem

MAX−CUT is one of the well-studied NP-hard combinatorial optimization problems. It can be formulated as an Integer Quadratic Programming problem and admits a simple relaxation obtained by replacing the integer “spin” variables xi by unitary vectors v⃗ i. The Goemans–Williamson rounding algorithm assigns the solution vectors of the relaxed quadratic program to a corresponding integer spin depending on the sign of the scalar product v⃗ i⋅r⃗ with a random vector r⃗ . Here, we investigate whether better graph cuts can be obtained by instead using a more sophisticated clustering algorithm. We answer this question affirmatively. Different initializations of k-means and k-medoids clustering produce better cuts for the graph instances of the most well known benchmark for MAX−CUT. In particular, we found a strong correlation of cluster quality and cut weights during the evolution of the clustering algorithms. Finally, since in general the maximal cut weight of a graph is not known beforehand, we derived instance-specific lower bounds for the approximation ratio, which give information of how close a solution is to the global optima for a particular instance. For the graphs in our benchmark, the instance specific lower bounds significantly exceed the Goemans–Williamson guarantee

An equatorial ultra iron-poor star identified in BOSS

We report the discovery of SDSS J131326.89-001941.4, an ultra iron-poor red giant star ([Fe/H] ~ -4.3) with a very high carbon abundance ([C/Fe]~ +2.5). This object is the fifth star in this rare class, and the combination of a fairly low effective temperature (Teff ~ 5300 K), which enhances line absorption, with its brightness (g=16.9), makes it possible to measure the abundances of calcium, carbon and iron using a low-resolution spectrum from the Sloan Digital Sky Survey. We examine the carbon and iron abundance ratios in this star and other similar objects in the light of predicted yields from metal-free massive stars, and conclude that they are consistent. By way of comparison, stars with similarly low iron abundances but lower carbon-to-iron ratios deviate from the theoretical predictions.Comment: 6 pages, 4 figures, accepted for publication in A&

Lung cancer mortality in European regions (1955-1997)

Background: The different spread of tobacco smoking across European countries has caused a substantial variability in lung cancer mortality. The objective of this investigation was to analyse the trends in lung cancer mortality rates in three broad European regions (Northern and Western countries, Eastern countries, and Mediterranean countries) during the second half of the 20th century. Patients and methods: Mortality data were obtained from the World Health Organisation database. Lung cancer mortality rates were age-standardised by the direct method to the world standard population. Trends from 1955 to 1997 were assessed by means of joinpoint regression analysis. Results: In men, rates in Eastern Europe increased to reach in the 1990s the highest values ever registered, while downward trends were observed in Northern and Western Europe since 1979, and in Mediterranean countries since the 1990s. In women, upward trends were observed in the three regions considered for the whole period. Conclusions: Different smoking prevalences over time explain the shift of almost one decade in the trends in Mediterranean men as compared with Northern and other Western European men. The persisting upward trends in women in the three regions are of concer

Septate junction proteins are required for cell shape changes, actomyosin reorganization and cell adhesion during dorsal closure in Drosophila

Septate junctions (SJs) serve as occluding barriers in invertebrate epithelia. In Drosophila, at least 30 genes are required for the formation or maintenance of SJs. Interestingly, loss-of-function mutations in core SJ components are embryonic lethal, with defects in developmental events such as head involution and dorsal closure (DC) that occur prior to the formation of a mature SJ, indicating a role for these proteins in mid-embryogenesis independent of their occluding function. To understand this novel function in development, we examined loss-of-function mutations in three core SJ proteins during the process of DC. DC occurs during mid-embryogenesis to seal a dorsal gap in the epidermis following germ band retraction. Closure is driven by contraction of the extraembryonic amnioserosa cells that temporarily cover the dorsal surface and by cell shape changes (elongation) of lateral epidermal cells that bring the contralateral sheets together at the dorsal midline. Using live imaging and examination of fixed tissues, we show that early events in DC occur normally in SJ mutant embryos, but during later closure, coracle, Macroglobulin complement-related and Neurexin-IV mutant embryos exhibit slower rates of closure and display aberrant cells shapes in the dorsolateral epidermis, including dorsoventral length and apical surface area. SJ mutant embryos also show mild defects in actomyosin structures along the leading edge, but laser cutting experiments suggest similar tension and viscoelastic properties in SJ mutant versus wild type epidermis. In a high percentage of SJ mutant embryos, the epidermis tears free from the amnioserosa near the end of DC and live imaging and immunostaining reveal reduced levels of E-cadherin, suggesting that defective adhesion may be responsible for these tears. Supporting this notion, reducing E-cadherin by half significantly enhances the penetrance of DC defects in coracle mutant embryos