The Intrinsically X-ray Weak Quasar PHL 1811. II. Optical and UV Spectra and Analysis

This is the second of two papers reporting observations and analysis of the unusually bright (m_b=14.4), luminous (M_B=-25.5), nearby (z=0.192) narrow-line quasar PHL 1811. The first paper reported that PHL 1811 is intrinsically X-ray weak, and presented a spectral energy distribution (SED). Here we present HST STIS optical and UV spectra, and ground-based optical spectra. The optical and UV line emission is very unusual. There is no evidence for forbidden or semiforbidden lines. The near-UV spectrum is dominated by very strong FeII and FeIII, and unusual low-ionization lines such as NaID and CaII H&K are observed. High-ionization lines are very weak; CIV has an equivalent width of 6.6A, a factor of ~5 smaller than measured from quasar composite spectra. An unusual feature near 1200A can be deblended in terms of Ly\alpha, NV, SiII, and CIII* using the blueshifted CIV profile as a template. Photoionization modeling shows that the unusual line emission can be explained qualitatively by the unusually soft SED. Principally, a low gas temperature results in inefficient emission of collisionally excited lines, including the semiforbidden lines generally used as density diagnostics. The emission resembles that of high-density gas; in both cases this is a consequence of inefficient cooling. PHL 1811 is very unusual, but we note that quasar surveys are generally biased against finding similar objects.Comment: Accepted for publication in ApJS. Full resolution figures available here: http://www.nhn.ou.edu/~leighly/phl1811_paper1.pd

Knowledge and attitudes of primary care physicians in the management of patients at risk for cardiovascular events

<p>Abstract</p> <p>Background</p> <p>Adherence to clinical practice guidelines for management of cardiovascular disease (CVD) is suboptimal. The purposes of this study were to identify practice patterns and barriers among U.S. general internists and family physicians in regard to cardiovascular risk management, and examine the association between physician characteristics and cardiovascular risk management.</p> <p>Methods</p> <p>A case vignette survey focused on cardiovascular disease risk management was distributed to a random sample of 12,000 U.S. family physicians and general internists between November and December 2006.</p> <p>Results</p> <p>Responses from a total of 888 practicing primary care physicians who see 60 patients per week were used for analysis. In an asymptomatic patient at low risk for cardiovascular event, 28% of family physicians and 37% of general internists made guideline-based preventive choices for no antiplatelet therapy (p < .01). In a patient at high risk for cardiovascular event, 59% of family physicians and 56% of general internists identified the guideline-based goal for serum fasting LDL level (< 100 mg/dl). Guideline adherence was inversely related to years in practice and volume of patients seen. Cost of medications (87.7%), adherence to medications (74.1%), adequate time for counseling (55.7%), patient education tools (47.1%), knowledge and skills to recommend dietary changes (47.8%) and facilitate patient adherence (52.0%) were cited as significant barriers to CVD risk management.</p> <p>Conclusion</p> <p>Despite the benefits demonstrated for managing cardiovascular risks, gaps remain in primary care practitioners' management of risks according to guideline recommendations. Innovative educational approaches that address barriers may facilitate the implementation of guideline-based recommendations in CVD risk management.</p

Agent-based Social Psychology: from Neurocognitive Processes to Social Data

Moral Foundation Theory states that groups of different observers may rely on partially dissimilar sets of moral foundations, thereby reaching different moral valuations. The use of functional imaging techniques has revealed a spectrum of cognitive styles with respect to the differential handling of novel or corroborating information that is correlated to political affiliation. Here we characterize the collective behavior of an agent-based model whose inter individual interactions due to information exchange in the form of opinions are in qualitative agreement with experimental neuroscience data. The main conclusion derived connects the existence of diversity in the cognitive strategies and statistics of the sets of moral foundations and suggests that this connection arises from interactions between agents. Thus a simple interacting agent model, whose interactions are in accord with empirical data on conformity and learning processes, presents statistical signatures consistent with moral judgment patterns of conservatives and liberals as obtained by survey studies of social psychology.Comment: 11 pages, 4 figures, 2 C codes, to appear in Advances in Complex System

A Comparative Study of the Absolute-Magnitude Distributions of Supernovae

The Asiago Supernova Catalog is used to carry out a comparative study of supernova absolute-magnitude distributions. An overview of the absolute magnitudes of the supernovae in the current observational sample is presented, and the evidence for subluminous and overluminous events is examined. The fraction of supernovae that are underluminous (M_B > -15) appears to be higher (perhaps much higher) than one fifth but it remains very uncertain. The fraction that are overluminous (M_B < -20) is lower (probably much lower) than 0.01. The absolute-magnitude distributions for each supernova type, restricted to events within 1 Gpc, are compared. Although these distributions are affected by observational bias in favor of the more luminous events, they are useful for comparative studies. We find mean absolute blue magnitudes (for H_0=60) of -19.46 for normal Type Ia supernovae (SNe Ia), -18.04 for SNe Ibc, -17.61 and -20.26 for normal and bright SNe Ibc considered separately, -18.03 for SNe II-L, -17.56 and -19.27 for normal and bright SNe II-L considered separately, -17.00 for SNe II-P, and -19.15 for SNe IIn.Comment: 27 pages, accepted for publication by the Astronomical Journal (Feb. 2002

Direct Analysis of Spectra of the Unusual Type Ib Supernova 2005bf

Synthetic spectra generated with the parameterized supernova synthetic-spectrum code SYNOW are compared to spectra of the unusual Type Ib supernova 2005bf. We confirm the discovery by Folatelli et al. (2006) that very early spectra (about 30 days before maximum light) contain both photospheric-velocity (8000 km/s) features of He I, Ca II, and Fe II, and detached high-velocity (14,000 km/s) features of H-alpha, Ca II, and Fe II. An early spectrum of SN 2005bf is an almost perfect match to a near-maximum-light spectrum of the Type Ib SN 1999ex. Although these two spectra were at very different times with respect to maximum light (20 days before maximum for SN 2005bf and five days after for SN 1999ex), they were for similar times after explosion - about 20 days for SN 2005bf and 24 days for SN 1999ex. The almost perfect match clinches the previously suggested identification of H-alpha in SN 1999ex and supports the proposition that many if not all Type Ib supernovae eject a small amount of hydrogen. The earliest available spectrum of SN 2005bf resembles a near-maximum-light spectrum of the Type Ic SN 1994I. These two spectra also were at different times with respect to maximum light (32 days before maximum for SN 2005bf and four days before for SN 1994I) but at similar times after explosion - about eight days for SN 2005bf and 10 days for SN 1994I. The resemblance motivates us to consider a reinterpretation of the spectra of Type Ic supernovae, involving coexisting photospheric-velocity and high-velocity features. The implications of our results for the geometry of the SN 2005bf ejecta, which has been suggested to be grossly asymmetric, are briefly discussed.Comment: Accepted by PAS

FUSE Observation of the Narrow-line Seyfert 1 Galaxy RE 1034+39

We present analysis from simultaneous FUSE, ASCA, and EUVE observations, as well as a reanalysis of archival HST spectra, from the extreme Narrow-line Seyfert 1 Galaxy RE 1034+39 (KUG 1031+398). RE 1034+39 has an unusually hard spectral energy distribution (SED) that peaks in the soft X-rays. Its emission lines are unusual in that they can all be modelled as a Lorentzian centered at the rest wavelength with only a small range in velocity widths. In order to investigate whether the unusual SED influences the emission line ratios and equivalent widths, we present three complementary types of photoionization analysis. The FUSE spectrum was particularly important because it includes the high-ionization line OVI. First, we use the photoionization code Cloudy and the SED developed from the coordinated observations to confirm that the emission lines are consistent with observed hard SED. The best model parameters were an ionization parameter log(U) ~ -2 and a hydrogen number density log(n_H)=9.75 [cm^-2]. Second, we present a Locally Optimally-emitting Cloud model. This model produced enhanced OVI as observed, but also yielded far too strong MgII. Third, we develop a series of semi-empirical SEDs, run Cloudy models, and compare the results with the measured values using a figure of merit (FOM). The FOM minimum indicates similar SED and gas properties as were inferred from the one-zone model using the RE 1034+39 continuum. Furthermore, the FOM increases sharply toward softer continua, indicating that a hard SED is required by the data in the context of a one-zone model.Comment: 65 pages 20 figure

An Interactive Internet-Based Continuing Education Course on Sexually Transmitted Diseases for Physicians and Midwives in Peru

Clinicians in developing countries have had limited access to continuing education (CE) outside major cities, and CE strategies have had limited impact on sustainable change in performance. New educational tools could improve CE accessibility and effectiveness.The objective of this study was to evaluate an interactive Internet-based CE course on Sexually Transmitted Diseases (STDs) management for clinicians in Peru. Participants included physicians and midwives in private practice drawn from a census of 10 Peruvian cities. The CE included a three-hour workshop for improving Internet skills, followed by a 22-hour online course on STD-syndrome-management, with subsequent educational support. The course used case-based clinical vignettes tailored to local STD problems. Knowledge and reported practices on STD management were assessed before, immediately after and at four months after completion of the course. Statistical analysis included parametric tests-linear regression multivariate analysis, paired t-test and repeated measures ANOVA using SPSS 14.0. Of 1,071 eligible clinicians, 510 agreed to participate, as did an additional 132 public sector clinicians. Of these 642 participants, 619 (96.4%) completed the course, and 596 (96.3%) took the four-month follow-up evaluation. Physician and midwife scores improved from 64.2% correct answers on the pre-test to 77.9% correct on the four-month follow-up test (p<0.001). Most participants (95%) found the online course useful for their work needs. Self reported STD management practices did not change.Among physicians and midwives in Peru, an Internet-based CE course was feasible, acceptable with high participation rates, and led to sustained improvement in knowledge at four months. Further studies are needed to test it as a model for improving the training of physicians, midwives, and other health care providers