The Spectral Correlation Function -- A New Tool for Analyzing Spectral-Line Maps

The "spectral correlation function" analysis we introduce in this paper is a new tool for analyzing spectral-line data cubes. Our initial tests, carried out on a suite of observed and simulated data cubes, indicate that the spectral correlation function [SCF] is likely to be a more discriminating statistic than other statistical methods normally applied. The SCF is a measure of similarity between neighboring spectra in the data cube. When the SCF is used to compare a data cube consisting of spectral-line observations of the ISM with a data cube derived from MHD simulations of molecular clouds, it can find differences that are not found by other analyses. The initial results presented here suggest that the inclusion of self-gravity in numerical simulations is critical for reproducing the correlation behavior of spectra in star-forming molecular clouds.Comment: 29 pages, including 4 figures (tar file submitted as source) See also: http://cfa-www.harvard.edu/~agoodman/scf/velocity_methods.htm

Back to the Future: Hybrid Co-operative Pensions and the TIAA-CREF System

Hybrid retirement plans that combine the best features of defined benefit and defined contribution plans can provide an efficient and equitable method of ensuring retirement security for workers. Co-operative pension structures also enhance retirement security through risk pooling and leveraging economies of scale. Yet most U.S. private sector workers are not covered by these types of plan design. The TIAA-CREF system, which began in 1918 and covers millions of workers in the non-profit sector, provides an example of a plan design with features of a hybrid co-operative pension. We examine the historical performance of the core components, TIAA (a guaranteed fixed annuity) and CREF (a variable annuity), discuss key design features, and analyze data on contributions, investment returns, risk pooling, and retirement distribution characteristics

Judicial Review of Federal Administrative Action: Quest for the Optimum Forum

Professors Currie and Goodman present a comprehensive analysis of the variables that must be isolated and weighed in determining the optimum forum for judicial review of administrative action. While the backdrop for this study is the caseload crisis presently confronting the federal courts of appeals, their discussion illuminates the requisites for optimum judicial review generally. Failing to perceive any compelling reason to single out administrative cases for review in separate courts, the authors argue against the creation of special administrative appeals courts. Even if such courts were to enjoy broad subject matter jurisdiction over the most demanding aspects of the agency review caseload, countervailing considerations, such as the danger of improper influence on the appointment process and the loss of the judges\u27 generalist perspective, outweigh the perceived benefits of uniformity, expertise and relief for the regional courts of appeals. As to the optimal forum within the present system of district courts and courts of appeals, the authors divide their discussion into three categories of agency action. With respect to formal agency determinations, the authors generally favor direct appellate court review, except where diversion to the district courts in the first instance is necessary to reduce an appellate workload which has grown to such proportions that it threatens the collegial nature of circuit court decisionmaking; and among two-tier systems, the authors suggest that discretionary appellate review be limited to areas generating a burdensome volume of appeals, involving issues or interests of relative insignificance and not bearing a potential for biased or misguided trial court decisions. Informal rulemaking, generally involving issues of legal importance which are likely to ultimately reach the courts of appeals in any event, is presumptively appropriate for direct appellate review. Despite the absence of a trial-type record, the courts of appeals will not have to engage in extensive factfinding, for any factual issues will increasingly be determined on the basis of materials before the agency, and any need for new factual information will be rare and obtainable by methods short of a judicial trial. In the case of informal .adjudication, however, the absence of a formal adjudicative record justifies a presumption in favor of initial district court review. Informal rulemaking is distinguished, for the issues arising from informal adjudication are likely to involve questions of specific fact, there is little guarantee of any meaningful record for review, and a larger proportion of such determinations are relatively unimportant and unlikely to be taken to the courts of appeals. The authors recognize that direct circuit court review may be appropriate if review is limited to reconstruction of the record before the agency and there is therefore no significant factfinding burden

Judicial Review of Federal Administrative Action: Quest for the Optimum Forum

Professors Currie and Goodman present a comprehensive analysis of the variables that must be isolated and weighed in determining the optimum forum for judicial review of administrative action. While the backdrop for this study is the caseload crisis presently confronting the federal courts of appeals, their discussion illuminates the requsites for optimum judicial review generally. Failing to perceive any compelling reason to single out administrative cases for review (in separate courts, the authors argue against the creation of special administrative appeals courts. Even if such courts were to enjoy broad subject matter jurisdiction over the most demanding aspects of the agency review caseload, countervailing considerations, such as the danger of improper influence on the appointment process and the loss of the judges\u27 generalist perspective, outweigh the perceived benefits of uniformity, expertise and relief for the regional courts of appeals. As to the optimal forum within the present system of district courts and courts of appeals, the authors divide their discussion into three categories of agency action. With respect to formal agency determinations, the authors generally favor direct appellate court , except where diversion to the district courts in the first instance ·is necessary to reduce an appellate workload which has grown to such proportions that threatens the collegial nature of circuit court decision making; and among two-tier systems, the authors suggest that discretionary appellate review be limited to areas generating a burdensome volume of appeals, involving issues or interests of relative insignificance and not bearing a potential for biased or misguided trial court decisions. Informal rule making , generally involving; issues of legal importance which are likely to ultimately reach the courts of appeals in any event, is presumptively appropriate for direct appellate review. Despite the absence of a trial-type record, the courts of appeals will not have to engage in extensive fact finding, for any factual issues ·will increasingly be determined on the basis of materials before the agency, and any need for new factual information will be rare and obtainable b;; methods short of a judicial trial. In the case of informal adjudication, however, the absence of a formal adjudicative record justifies a presumption in favor of initial district court review. Informal rule making is distinguished, for the issues arising from informal adjudication are likely to involve questions of specific fact, there is little guarantee of any meaningful record for review, and a larger pro portion of such determinations are relatively unimportant and unlikely to be taken to the courts of appeals. The authors recognize that direct circuit court review may be appropriate if review is limited to reconstruction of the record before the agency and there is therefore no significant fact finding burden

Improving Patient Decision-Making in Health Care

Outlines regional variations within Minnesota in rates of patients with similar conditions receiving elective surgery, the concept of shared decision making, treatment choices for eight conditions, and steps for ensuring patients make informed decisions

Interferometric weak value deflections: quantum and classical treatments

We derive the weak value deflection given in a paper by Dixon et al. (Phys. Rev. Lett. 102, 173601 (2009)) both quantum mechanically and classically. This paper is meant to cover some of the mathematical details omitted in that paper owing to space constraints

Blue horizontal branch stars in the Sloan Digital Sky Survey: II. Kinematics of the Galactic halo

We carry out a maximum-likelihood kinematic analysis of a sample of 1170 blue horizontal branch (BHB) stars from the Sloan Digital Sky Survey presented in Sirko et al. (2003) (Paper I). Monte Carlo simulations and resampling show that the results are robust to distance and velocity errors at least as large as the estimated errors from Paper I. The best-fit velocities of the Sun (circular) and halo (rotational) are 245.9 +/- 13.5 km/s and 23.8 +/- 20.1 km/s but are strongly covariant, so that v_0 - v_halo = 222.1 +/- 7.7 km/s. If one adopts standard values for the local standard of rest and solar motion, then the halo scarcely rotates. The velocity ellipsoid inferred for our sample is much more isotropic [(sigma_r,sigma_theta,sigma_phi) = (101.4 +/- 2.8, 97.7 +/- 16.4, 107.4 +/- 16.6) km/s] than that of halo stars in the solar neighborhood, in agreement with a recent study of the distant halo by Sommer-Larsen et al. (1997). The line-of-sight velocity distribution of the entire sample, corrected for the Sun's motion, is accurately gaussian with a dispersion of 101.6 +/- 3.0 km/s.Comment: 23 pages including 4 figures, 1 color; submitted to A

Truthmakers and modality

This paper attempts to locate, within an actualist ontology, truthmakers for modal truths: truths of the form or . In section 1 I motivate the demand for substantial truthmakers for modal truths. In section 2 I criticise Armstrong’s account of truthmakers for modal truths. In section 3 I examine essentialism and defend an account of what makes essentialist attributions true, but I argue that this does not solve the problem of modal truth in general. In section 4 I discuss, and dismiss, a theistic account of the source of modal truth proposed by Alexander Pruss. In section 5 I offer a means of (dis)solving the problem

A New Technique for Detecting Supersymmetric Dark Matter

We estimate the event rate for excitation of atomic transition by photino-like dark matter. For excitations of several eV, this event rate can exceed naive cross-section by many orders of magnitude. Although the event rate for these atomic excitation is smaller than that of nuclear recoil off of non-zero spin nuclei, the photons emitted by the deexcitation are easier to detect than low-energy nuclear recoils. For many elements, there are several low-lying states with comparable excitation rates, thus, spectral ratios could be used to distinguish signal from background.Comment: 6 pages plain te