Quantified HI Morphology VII: star-formation and tidal influence on local dwarf HI morphology

Scale-invariant morphology parameters applied to atomic hydrogen maps (HI) of galaxies can be used to quantify the effects of tidal interaction or star-formation on the ISM. Here we apply these parameters, Concentration, Asymmetry, Smoothness, Gini, M20, and the GM parameter, to two public surveys of nearby dwarf galaxies, the VLA-ANGST and LITTLE-THINGS survey, to explore whether tidal interaction or the ongoing or past star-formation is a dominant force shaping the HI disk of these dwarfs. Previously, HI morphological criteria were identified for ongoing spiral-spiral interactions. When we apply these to the Irregular dwarf population, they either select almost all or none of the population. We find that only the Asymmetry-based criteria can be used to identify very isolated dwarfs (i.e., these have a low tidal indication). Otherwise, there is little or no relation between the level of tidal interaction and the HI morphology. We compare the HI morphology to three star-formation rates based on either Halpha, FUV or the resolved stellar population, probing different star-formation time-scales. The HI morphology parameters that trace the inequality of the distribution, the Gini, GM, and M20 parameters, correlate weakly with all these star-formation rates. This is in line with the picture that local physics dominates the ISM appearance and not tidal effects. Finally, we compare the SDSS measures of star-formation and stellar mass to the HI morphological parameters for all four HI surveys. In the two lower-resolution HI surveys (12"), there is no relation between star-formation measures and HI morphology. The morphology of the two high-resolution HI surveys (6"), the Asymmetry, Smoothness, Gini, M20, and GM, do show a link to the total star-formation, but a weak one.Comment: 26 figures, 4 tables, two appendices. Third appendix (HI maps of all galaxies) omitted. Accepted by MNRA

Conceptualizing new forms of volunteering in urban governance

This article argues that developments in the spheres of the state, the market, and the community have changed their boundaries, affecting volunteering in urban governance. Shifts in the division of tasks between the state and community have led to a new form of manufactured volunteering, while technological developments have made it easier to bridge trust gaps, resulting in platform volunteering. Moreover, business organizations pursuing public goals and using public resources have created a new form of economic volunteering. Thus, three illustrative cases are used to explore these new forms of volunteering and their main strengths and weaknesses. These new forms challenge traditional conceptions of volunteering work and the ideal-typical role model of “the volunteer.”</p

Testing the Hypothesis of Modified Dynamics with Low Surface Brightness Galaxies and Other Evidence

The rotation curves of low surface brightness galaxies provide a unique data set with which to test alternative theories of gravitation over a large dynamic range in size, mass, surface density, and acceleration. Many clearly fail, including any in which the mass discrepancy appears at a particular length-scale. One hypothesis, MOND [Milgrom 1983, ApJ, 270, 371], is consistent with the data. Indeed, it accurately predicts the observed behavior. We find no evidence on any scale which clearly contradicts MOND, and a good deal which supports it.Comment: Accepted for publication in the Astrophysical Journal. 35 pages AAStex + 9 figures. This result surprised the bejeepers out of us, to

Calculation of 1/m^3 terms in the total semileptonic width of D mesons.

We calculate the 1/$m^3_c$ corrections in the inclusive semileptonic widths of $D$ mesons. We show that these are due to the novel penguin type operators that appear at this level in the transition operator. Taking into account the nonperturbative corrections leads to the predicted value of the semileptonic width significantly lower than the experimental value. The $1/m^3_c$ worsen the situation or at the very least, within uncertainty, give small contribution. We indicate possible ways out. It seems most probable that violations of duality are noticeable in the energy range characteristic to the inclusive decays in the charm family. Theoretically these deviations are related to divergence of the high-order terms in the power expansion in the inverse heavy quark mass.Comment: Final version accepted for publication in Physical Review D (19 pages, 5 figures appended as two PS files at the end of the LATEX file

Invariant structure of the hierarchy theory of fractional quantum Hall states with spin

We describe the invariant structure common to abelian fractional quantum Hall systems with spin. It appears in a generalization of the lattice description of the polarized hierarchy that encompasses both partially polarized and unpolarized ground state systems. We formulate, using the spin-charge decomposition, conditions that should be satisfied so that the description is SU(2) invariant. In the case of the spin- singlet hierarchy construction, we find that there are as many SU(2) symmetries as there are levels in the construction. We show the existence of a spin and charge lattice for the systems with spin. The ``gluing'' of the charge and spin degrees of freedom in their bulk is described by the gluing theory of lattices.Comment: 21 pages, LaTex, Submitted to Phys. Rev.

Quantified Morphology of HI Disks in the Universe

he upcoming new perspective of the high redshift Universe in the 21 cm line of atomic hydrogen opens possibilities to explore topics of spiral disk evolution, hitherto reserved for the optical regime. The growth of spiral gas disks over Cosmic time can be explored with the new generation of radio telescopes, notably the SKA, and its precursors, as accurately as with the Hubble Space Telescope for stellar disks. Since the atomic hydrogen gas is the building block of these disks, it should trace their formation accurately. Morphology of HI disks can now equally be quantified over Cosmic time. In studies of HST deep fields, the optical or UV morphology of high-redshift galaxy disks have been characterized using a few quantities: concentration (C), asymmetry (A), smoothness (S), second-order-moment (M20), the GINI coefficient (G), and Ellipticity (E). We have applied these parameters across wavelengths and compared them to the HI morphology over the THINGS sample. NGC 3184, an unperturbed disk, and NGC 5194, the canonical 3:1 interaction, serve as examples for quantified morphology. We find that morphology parameters determined in HI are as good or better a tracer of interaction compared to those in any other wavelength, notably in Asymmetry, Gini and M20. This opens the possibility of using them in the parameterization pipeline for SKA precursor catalogues to select interacting or harassed galaxies from their HI morphology. Asymmetry, Gini and M20 may be redefined for use on data-cubes rather than HI column density image.Comment: 6 pages, 3 figures, proceeding of the conference "Panoramic Radio Astronomy: Wide-field 1-2 GHz research on galaxy evolution", June 02 - 05 2009, Groningen, update after small edit

Quantified HI Morphology II : Lopsidedness and Interaction in WHISP Column Density Maps

Lopsidedness of the gaseous disk of spiral galaxies is a common phenomenon in disk morphology, profile and kinematics. Simultaneously, the asymmetry of a galaxy's stellar disk, in combination with other morphological parameters, has seen extensive use as an indication of recent merger or interaction in galaxy samples. Quantified morphology of stellar spiral disks is one avenue to determine the merger rate over much of the age of the Universe. In this paper, we measure the quantitative morphology parameters for the HI column density maps from the Westerbork observations of neutral Hydrogen in Irregular and SPiral galaxies (WHISP). These are Concentration, Asymmetry, Smoothness, Gini, M20, and one addition of our own, the Gini parameter of the second order moment (GM). Our aim is to determine if lopsided or interacting disks can be identified with these parameters. Our sample of 141 HI maps have all previous classifications on their lopsidedness and interaction. We find that the Asymmetry, M20, and our new GM parameter correlate only weakly with the previous morphological lopsidedness quantification. These three parameters may be used to compute a probability that an HI disk is morphologically lopsided but not unequivocally to determine it. However, we do find that that the question whether or not an HI disk is interacting can be settled well using morphological parameters. Parameter cuts from the literature do not translate from ultraviolet to HI directly but new selection criteria using combinations of Asymmetry and M20 or Concentration and M20, work very well. We suggest that future all-sky HI surveys may use these parameters of the column density maps to determine the merger fraction and hence rate in the local Universe with a high degree of accuracy.Comment: 12 pages, 5 figures, 1 table, accepted by MNRAS, appendix not include

Virtual Patient Technology: Engaging Primary Care in Quality Improvement Innovations

BACKGROUND: Engaging health care staff in new quality improvement programs is challenging. OBJECTIVE: We developed 2 virtual patient (VP) avatars in the context of a clinic-level quality improvement program. We sought to determine differences in preferences for VPs and the perceived influence of interacting with the VP on clinical staff engagement with the quality improvement program. METHODS: Using a participatory design approach, we developed an older male smoker VP and a younger female smoker VP. The older male smoker was described as a patient with cardiovascular disease and was ethnically ambiguous. The female patient was younger and was worried about the impact of smoking on her pregnancy. Clinical staff were allowed to choose the VP they preferred, and the more they engaged with the VP, the more likely the VP was to quit smoking and become healthier. We deployed the VP within the context of a quality improvement program designed to encourage clinical staff to refer their patients who smoke to a patient-centered Web-assisted tobacco intervention. To evaluate the VPs, we used quantitative analyses using multivariate models of provider and practice characteristics and VP characteristic preference and analyses of a brief survey of positive deviants (clinical staff in practices with high rates of encouraging patients to use the quit smoking innovation). RESULTS: A total of 146 clinical staff from 76 primary care practices interacted with the VPs. Clinic staff included medical providers (35/146, 24.0%), nurse professionals (19/146, 13.0%), primary care technicians (5/146, 3.4%), managerial staff (67/146, 45.9%), and receptionists (20/146, 13.7%). Medical staff were mostly male, and other roles were mostly female. Medical providers (OR 0.031; CI 0.003-0.281; P=.002) and younger staff (OR 0.411; CI 0.177-0.952; P=.038) were less likely to choose the younger, female VP when controlling for all other characteristics. VP preference did not influence online patient referrals by staff. In high-performing practices that referred 20 or more smokers to the ePortal (13/76), the majority of clinic staff were motivated by or liked the virtual patient (20/26, 77%). CONCLUSIONS: Medical providers are more likely motivated by VPs that are similar to their patient population, while nurses and other staff may prefer avatars that are more similar to them

Higher Order Power Corrections in Inclusive B Decays

We discuss order 1/m_b^4 and 1/m_b^5 corrections in inclusive semileptonic decay of a $B$ meson. We identify relevant hadronic matrix elements of dimension seven and eight and estimate them using the ground-state saturation approximation. Within this approach the effects on the integrated rate and on kinematic moments are estimated. The overall relative shift in V_{cb} turns out about +0.4% as applied to the existing fits. Similar estimates are presented for B -> X_s+\gamma decays.Comment: 30 pages, 16 figure

Map or Gantt? Which Diagram Helps Viewers Best in Spatio-Temporal Data Exploration Tasks?

In this paper we investigate the effectiveness and efficiency of two two-dimensional static visual representations of spatio-temporal data, a map-based and a Gantt-based diagram, in their support of various information retrieval tasks. The map-based diagram is characterized by a natural spatial arrangement of locations on a schematic map. The Gantt-based one represents time naturally as a linearly ordered set of time intervals from left to right. A within-subject empirical experiment has been conducted, in which participants were asked to verify queries about persons, locations, and time intervals. The formulation of the queries was based on (i) Bertin’s three reading levels, (ii) certain cognitive operations, and (iii) different syntactic orders of expressions denoting persons, locations and times. Response correctness and response time were recorded. With respect to response accuracy, both diagrams support viewers well in nearly all information retrieval tasks. Regarding efficiency, the map-based diagram elicited significantly faster response times than the Gantt-based one, except for queries with time in focus. The results suggest that map-based diagrams require less search and reasoning effort of viewers to retrieve the information asked for in the task types used in this study.</p