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We have used the Hydra fiber positioner and the bench spectrograph on the KPNO 4 m telescope to measure radial velocities for giants in the Draco (Dra) and Ursa Minor (UMi) dwarf spheroidal galaxies. The measurement uncertainties are 1–10 km s−1 per observation, with the median uncertainty being 3.6 km s−1. To date, we have reduced the data from two of our three runs. In UMi these have yielded 150 velocities for 85 member giants; 52 stars have two or more measurements. In Dra we have 108 velocities for 84 member giants and 20 stars have two or more measurements. There is good agreement between the repeat observations and with the Olszewski, Aaronson, & Hill (1995) MMT echelle velocities.
The WFPC2 aboard the Hubble Space Telescope has been used to obtain deep images in three fields at different radial positions in the nearest Globular cluster, M4 (NGC 6121). In this paper, we discuss the white dwarf cooling sequence and show how the dynamical structure of the cluster will affect their cumulative distribution function. We also present the first discussion of our observations of the faint cluster main sequence stars.
Primordial binaries in globular clusters are important both because their properties are an integral part of the description of the stellar population and because they can strongly influence the dynamical evolution of the cluster (see Hut, this volume).
Though the US civilian trauma care system plays a critical role in disaster response, there is currently no systems-based strategy that enables hospital emergency management and local and regional emergency planners to quantify, and potentially prepare for, surges in trauma care demand that accompany mass-casualty disasters.
A proof-of-concept model that estimates the geographic distributions of patients, trauma center resource usage, and mortality rates for varying disaster sizes, in and around the 25 largest US cities, is presented. The model was designed to be scalable, and its inputs can be modified depending on the planning assumptions of different locales and for different types of mass-casualty events.
To demonstrate the model’s potential application to real-life planning scenarios, sample disaster responses for 25 major US cities were investigated using a hybrid of geographic information systems and dynamic simulation-optimization. In each city, a simulated, fast-onset disaster epicenter, such as might occur with a bombing, was located randomly within one mile of its population center. Patients then were assigned and transported, in simulation, via the new model to Level 1, 2, and 3 trauma centers, in and around each city, over a 48-hour period for disaster scenario sizes of 100, 500, 5000, and 10,000 casualties.
Across all 25 cities, total mean mortality rates ranged from 26.3% in the smallest disaster scenario to 41.9% in the largest. Out-of-hospital mortality rates increased (from 21.3% to 38.5%) while in-hospital mortality rates decreased (from 5.0% to 3.4%) as disaster scenario sizes increased. The mean number of trauma centers involved ranged from 3.0 in the smallest disaster scenario to 63.4 in the largest. Cities that were less geographically isolated with more concentrated trauma centers in their surrounding regions had lower total and out-of-hospital mortality rates. The nine US cities listed as being the most likely targets of terrorist attacks involved, on average, more trauma centers and had lower mortality rates compared with the remaining 16 cities.
The disaster response simulation model discussed here may offer insights to emergency planners and health systems in more realistically planning for mass-casualty events. Longer wait and transport times needed to distribute high numbers of patients to distant trauma centers in fast-onset disasters may create predictable increases in mortality and trauma center resource consumption. The results of the modeled scenarios indicate the need for a systems-based approach to trauma care management during disasters, since the local trauma center network was often too small to provide adequate care for the projected patient surge. Simulation of out-of-hospital resources that might be called upon during disasters, as well as guidance in the appropriate execution of mutual aid agreements and prevention of over-response, could be of value to preparedness planners and emergency response leaders. Study assumptions and limitations are discussed.
A Geographic Simulation Model for the Treatment of Trauma Patients in Disasters. Prehosp Disaster Med.2016;31(4):413–421.
Kuhn & Miller (1989, KM hereafter) proposed that a small stellar system in orbit around a large galaxy could be heated through resonant coupling between the orbital motion and internal modes of oscillation of the satellite. They further argued that the apparently large mass-to-light (M/L) ratios of dwarf spheroidal (dSph) galaxies around the Milky Way (e.g., Armandroff, Olszewski & Pryor 1995) could be illusory because the satellites are far from virial equilibrium as a consequence of such resonant heating. We note that if the true M/Ls are small, some dSphs have much more kinetic energy than is required to unbind them; a resonant pumping mechanism which adds a modest amount of energy each cycle could not achieve this (Pryor 1996).
Binary stars in a globular cluster (hereafter, GC) may be primordial (i.e. formed along with the cluster), or the result of cluster dynamics. “Dynamical” binaries can result from conservative three-body encounters (e.g. Spitzer, 1987) if a third star can carry away enough kinetic energy to leave two others bound, or from dissipative two-body encounters, if two stars happen to pass within a few stellar radii of one other (Fabian, Pringle, & Rees, 1975). Such non-primordial systems are likely to be found primarily in evolved GC cores, both because conditions are more favorable for making them there, and because of mass segregation. Knowledge of the formation process allows reasonable estimates to be made of their mass and energy distributions. The initial spatial, mass, and energy distributions of primordial binaries, on the other hand, are largely unknown.
Natural law has made a comeback in legal philosophy. The revival of natural law thinking in the legal academy began about thirty years ago and has managed to gain a seat at the table in current jurisprudential discussions. Defining natural law, Brian Bix declares that it “claims that there are fundamental and evaluative connections between the universe, human nature, and morality.” These connections need not have a Christian or even a theistic foundation. A belief in moral realism, that is, the propositions that “(1) there is an objective reality, (2) human beings can know something about it, and (3) there are some things that everyone can, and some things that everyone ought to, do in response to what they know,” ties together theistic and non-theistic versions of natural law. Yet many prominent contemporary natural law theorists—J. Budziszewski, John Finnis, Robert George, and Russell Hittinger —are Roman Catholic. Despite the fact that Finnis and George develop their natural law arguments without reference to any metaphysical states of affairs or transcendent truth claims, natural law continues to be associated with Thomas Aquinas and the subsequent scholastic tradition. Thus, even standards that Finnis and George derive from the internal rationality of law strike some as disguised theology.
We use Raman scattering to study the spatially-resolved strain and stress in a complex zinc blende GaAs/GaP heterostructured nanowire which contains both axial and radial interfaces. The nanowires are grown by metal-organic chemical vapor deposition in the  direction with Au nano particles as catalysts, High spatial resolution Raman scans along the nanowires show the GaAs/GaP interface is clearly identifiable. We interpret the phonon energy shifts in each material as one approaches the interface.
The discovery and initial excavation of an unenclosed, timber platform settlement site of Late Bronze Age date is described. The site is located in open Fen just off the Fen-edge at Fengate in an area of well-known prehistoric activity. The site includes the remains of a remarkably well-preserved three-aisled rectangular building, with at least two floor levels still intact. Finds include items of pottery, flint and wood. Current environmental research is outlined and the report concludes with a discussion of the site's role and status.
In this paper, we present our recent work on the evolution of abundance gradients along the Milky Way disk based on the Geneva Copenhagen Survey (GCS) and Radial Velocity Experiment (RAVE) data. We will also discuss the role of the LAMOST Milky Way disk survey in clarifying the properties of metallicity breaks observed through open clusters and young tracers along the Milky Way disk. It is believed that the Galactic disk forms inside-out, in which the stellar population at increasing radii is younger and more metal poor. This picture is consistent with most Galactic Chemical Evolution (GCE) models which also predict a tight correlation between the metallicity and age of stars at a given radius. However, it is only a result of “steady state" and no dynamical evolution effects were taken into account. We have selected two stellar samples from GCS and RAVE, each sample contains about 10,000 local thin-disk, main-sequence stars. We use the guiding radius which is determined by the conservation of z-direction angular momentum, to eliminate the blurring effects. And also use the effective temperature of the main sequence stars as a proxy of stellar age. It is shown that the metallicity gradient flattens as the age increases. This is not consistent with our previous GCE prediction, but can be explained by radial mixing effects. In order to further demonstrate the abundance breaks observed in the Galactic disk we have proposed, and have been carrying out, an open cluster survey project based on LAMOST. We plan to observe at least 400 open clusters in the northern Galactic sky. From the observations, we will get uniform parameters for those clusters with radial velocity and metallicities. We anticipate that this uniform open cluster sample could clarify the observed abundance break around the Milky Way disk corotation radius and also give a more robust result concerning the evolution of the abundance gradient.
New observations are presented on the emission of electrons from n-type boron nitride (BN) cold cathode films. These carbon-doped BN films demonstrate a significant improvement in the electron emission current, on the order of 1 to 3 orders of magnitude, as a function of the extraction field for many different materials and morphologies.
These BN cold cathodes have yielded stable DC currents in excess of 4 mA at an extraction field of approximately 30 V/μm.