Historical Statistics of the United States Chapter on Voluntary, Nonprofit, and Religious Entities and Activities: Underlying Concepts, Concerns, and Opportunities

This paper is a draft of the introduction to the chapter on voluntary, nonprofit, and religious entities and activities slated to appear in the Millennial Edition of Historical Statistics of the United States (forthcoming, Cambridge University Press). Conceding the various problematic definitions of the "nonprofit sector," the essay offers a rationale for the broadly inclusive approach to the selection of historical statistics of institutions and activities presented in the chapter. In addition, it reviews the challenges and opportunities for researchers working on the statistical aspects of nonprofit, voluntary, and religious organizations. The essay includes samples of the statistical series that will appear in HSUS.This publication is Hauser Center Working Paper No. 14. The Hauser Center Working Paper Series was launched during the summer of 2000. The Series enables the Hauser Center to share with a broad audience important works-in-progress written by Hauser Center scholars and researchers

The variational slope of quasar light curves is not a distance indicator

When the time difference quotients, or \emph{variational slopes}, of quasar light curves are plotted against their absolute magnitudes, there is a tight positive correlation of $\sim 0.16$ dex in the variational slope direction or $\sim 0.5$ dex in the absolute magnitude direction. This finding resulted in suggestions that a variational slope -- luminosity relation could be used as a distance indicator. However, I show that this relation can be explained almost entirely from self-correlation with luminosity. After properly accounting for the self-correlation component, the relation has a true scatter of $\sim 1.5$ dex in luminosity, consistent with established correlations for quasar variability amplitudes. Given this large scatter, correlation with variational slope or variability amplitude and luminosity is not by itself a suitable distance indicator for quasars.Comment: 3 pages, 1 figure. Accepted for publication in MNRA

Giant Cell Tumor of Bone: Documented Progression over 4 Years from Its Origin at the Metaphysis to the Articular Surface.

The exact location of origin for giant cell tumors of bone (GCTB) remains controversial, as lesions are not routinely imaged early but rather late when the tumor is large and clinically symptomatic. At the time of diagnosis, GCTB are classically described as lucent, eccentric lesions with nonsclerotic margins, located within the epiphysis to a greater extent than the metaphysis. Here we present a case of a biopsy proven GCTB initially incidentally seen on MRI as a small strictly metaphyseal lesion, which over the course of several years expanded across a closed physis to involve the epiphysis and abut the articular surface/subchondral bone plate

Enhancing electrochemical intermediate solvation through electrolyte anion selection to increase nonaqueous Li-O2_2 battery capacity

Among the 'beyond Li-ion' battery chemistries, nonaqueous Li-O$_2$ batteries have the highest theoretical specific energy and as a result have attracted significant research attention over the past decade. A critical scientific challenge facing nonaqueous Li-O$_2$ batteries is the electronically insulating nature of the primary discharge product, lithium peroxide, which passivates the battery cathode as it is formed, leading to low ultimate cell capacities. Recently, strategies to enhance solubility to circumvent this issue have been reported, but rely upon electrolyte formulations that further decrease the overall electrochemical stability of the system, thereby deleteriously affecting battery rechargeability. In this study, we report that a significant enhancement (greater than four-fold) in Li-O$_2$ cell capacity is possible by appropriately selecting the salt anion in the electrolyte solution. Using $^7$Li nuclear magnetic resonance and modeling, we confirm that this improvement is a result of enhanced Li$^+$ stability in solution, which in turn induces solubility of the intermediate to Li$_2$O$_2$ formation. Using this strategy, the challenging task of identifying an electrolyte solvent that possesses the anti-correlated properties of high intermediate solubility and solvent stability is alleviated, potentially providing a pathway to develop an electrolyte that affords both high capacity and rechargeability. We believe the model and strategy presented here will be generally useful to enhance Coulombic efficiency in many electrochemical systems (e.g. Li-S batteries) where improving intermediate stability in solution could induce desired mechanisms of product formation.Comment: 22 pages, 5 figures and Supporting Informatio

PhoSim-NIRCam: Photon-by-photon image simulations of the James Webb Space Telescope's Near-Infrared Camera

Recent instrumentation projects have allocated resources to develop codes for simulating astronomical images. Novel physics-based models are essential for understanding telescope, instrument, and environmental systematics in observations. A deep understanding of these systematics is especially important in the context of weak gravitational lensing, galaxy morphology, and other sensitive measurements. In this work, we present an adaptation of a physics-based ab initio image simulator: The Photon Simulator (PhoSim). We modify PhoSim for use with the Near-Infrared Camera (NIRCam) -- the primary imaging instrument aboard the James Webb Space Telescope (JWST). This photon Monte Carlo code replicates the observational catalog, telescope and camera optics, detector physics, and readout modes/electronics. Importantly, PhoSim-NIRCam simulates both geometric aberration and diffraction across the field of view. Full field- and wavelength-dependent point spread functions are presented. Simulated images of an extragalactic field are presented. Extensive validation is planned during in-orbit commissioning

The Curious Case of PHL 293B : a long-lived transient in a Metal-poor Blue Compact Dwarf Galaxy

We report on small-amplitude optical variability and recent dissipation of the unusually persistent broad emission lines in the blue compact dwarf galaxy PHL 293B. The galaxy's unusual spectral features (P Cygni-like profiles with ~800 km s−1 blueshifted absorption lines) have resulted in conflicting interpretations of the nature of this source in the literature. However, analysis of new Gemini spectroscopy reveals the broad emission has begun to fade after being persistent for over a decade prior. Precise difference imaging light curves constructed with the Sloan Digital Sky Survey and the Dark Energy Survey reveal small-amplitude optical variability of ~0.1 mag in the g band offset by 100 ± 21 pc from the brightest pixel of the host. The light curve is well-described by an active galactic nuclei (AGN)-like damped random walk process. However, we conclude that the origin of the optical variability and spectral features of PHL 293B is due to a long-lived stellar transient, likely a Type IIn supernova or nonterminal outburst, mimicking long-term AGN-like variability. This work highlights the challenges of discriminating between scenarios in such extreme environments, relevant to searches for AGNs in dwarf galaxies. This is the second long-lived transient discovered in a blue compact dwarf, after SDSS1133. Our result implies such long-lived stellar transients may be more common in metal-deficient galaxies. Systematic searches for low-level variability in dwarf galaxies will be possible with the upcoming Legacy Survey of Space and Time at the Vera C. Rubin Observatory

The effect of music on tibial accelerations in recreationally active runners

The purpose of this study was to examine the effects of music on the peak tibial acceleration (PTA) and loading rate (LR) during running, along with other secondary physiological stresses. Thirty college-aged recreationally active subjects completed one continuous 30-minute treadmill bout at a self-selected intensity, with 15 minutes spent listening to music. The music order was counterbalanced. PTA, LR, heart rate (HR), rating of perceived exertion (RPE), and feeling score (FS) were assessed every 3 minutes. Salivary cortisol was assessed before, during, and post-exercise. There was no difference between music and no music conditions for PTA, LR, HR, RPE, or cortisol (p>0.05). FS was significantly greater when listening to music (p<0.005), indicating more enjoyment. In conclusion, listening to music increases feelings of wellbeing but is not enough of a distracting stimulus to alter the biomechanics or physiological stress of running, indicating no heightened risk of injury.Master of Art

Dwarf AGNs from Variability for the Origins of Seeds (DAVOS): Optical Variability of Broad-line Dwarf AGNs from the Zwicky Transient Facility

We study the optical variability of a sample of candidate low-mass (dwarf ang Seyfert) active galactic nuclei (AGNs) using Zwicky Transient Facility g-band light curves. Our sample is compiled from broad-line AGNs in dwarf galaxies reported in the literature with single-epoch virial black hole (BH) masses in the range $M_{\rm{BH}} \sim 10^{4}$--$10^{8}\ M_{\odot}$. We measure the characteristic ``damping'' timescale of the optical variability $\tau_{\rm{DRW}}$, beyond which the power spectral density flattens, of a final sample of 79 candidate low-mass AGNs with high-quality light curves. Our results provide further confirmation of the $M_{\rm{BH}} - \tau_{\rm{DRW}}$ relation from Burke et al. 2022 within $1\sigma$ agreement, adding 78 new low-mass AGNs to the relation. The agreement suggests that the virial BH mass estimates for these AGNs are generally reasonable. We expect that the optical light curve of an accreting intermediate-mass black hole (IMBH) to vary with a rest-frame damping timescale of $\sim$ tens of hours, which could enable detection and direct mass estimation of accreting IMBHs in wide-field time-domain imaging surveys with sufficient cadence like with the Vera C. Rubin Observatory.Comment: 9 pages plus 6 appendix, 7 figure