Parsimony in model selection: tools for assessing fit propensity

Theories can be represented as statistical models for empirical testing. There is a vast literature on model selection and multimodel inference that focuses on how to assess which statistical model, and therefore which theory, best fits the available data. For example, given some data, one can compare models on various information criterion or other fit statistics. However, what these indices fail to capture is the full range of counterfactuals. That is, some models may fit the given data better not because they represent a more correct theory, but simply because these models have more fit propensity - a tendency to fit a wider range of data, even nonsensical data, better. Current approaches fall short in considering the principle of parsimony (Occam’s Razor), often equating it with the number of model parameters. Here we offer a toolkit for researchers to better study and understand parsimony through the fit propensity of Structural Equation Models. We provide an R package (ockhamSEM) built on the popular lavaan package. To illustrate the importance of evaluating fit propensity, we use ockhamSEM to investigate the factor structure of the Rosenberg Self-Esteem Scale

Historical Observations and Identifications of Plants and Animals in the Vicinity of Engineer Cantonment in 1819-1820

Historical observations and identifications of plants and animals in the vicinity of Engineer Cantonment in 1819–1820 (James 1822) are shown below in Roman and Roman italic print. Specimens identified through phytoarcheological and zooarcheological analysis of materials and believed to be reasonably associated or contemporaneous with the Long Expedition use of the site (AU4) are shown in boldface. Species present in both the historical and archeological data are marked by an asterisk (*). References used in this compilation include Benedict (1996), Brewer (1970 [1840]), Conant and Collins (1991), Ducey (2000), Evans (1997), Falk et al. (this volume), Genoways et al. (2008), Goodman and Lawson (1995), Jones (1964), Kaul et al. (2011), Lynch (1985), Nepstad-Thornberry and Bozell (this volume), Ord (1815), Page et al. (2013), Peyton (2000), Picha (this volume), Rhoads (1894), Sharpe et al. (2001), Turgeon et al. (1998), and Wilson and Reeder (2005). Modifi ed and revised from Genoways and Ratcliffe (2008). Includes scientific names, common names, comments, and references cited

Unpacking Cultural Differences in Alexithymia: The Role of Cultural Values Among Euro-Canadian and Chinese-Canadian Students

The current study provides a cultural examination of alexithymia, a multifaceted personality construct that refers to a general deficit in the ability to identify and describe emotional states, and that has been linked to a number of psychiatric illnesses. Though this construct has been critiqued as heavily rooted in “Western” norms of emotional expression, it has not received much empirical attention from a cultural perspective. Recently, Ryder et al. (2008) found that higher levels of alexithymia among Chinese versus Euro-Canadian outpatients were explained by group differences in one component of alexithymia, externally oriented thinking (EOT); they proposed that Chinese cultural contexts may encourage EOT due to a greater emphasis on social relationships and interpersonal harmony rather than inner emotional experience. The current study examined the hypothesis that EOT is more strongly shaped by cultural values than are two other components of alexithymia, difficulty identifying feelings (DIF) and difficulty describing feelings (DDF). Euro-Canadian (n = 271) and Chinese-Canadian (n = 237) undergraduates completed measures of alexithymia and cultural values. Chinese-Canadians showed higher levels of EOT than Euro-Canadians (p < .001). EOT, and not DIF or DDF, was predicted by Modernization and Euro-American values in both groups. Furthermore, cultural values mediated the effect of group membership on levels of EOT. These results suggest that cultural differences in alexithymia may be explained by culturally based variations in the importance placed on emotions, rather than deficits in emotional processing. The study also raises questions about the measurement and meaning of EOT, particularly from a cross-cultural perspective

Exploring Endotypes in Chronic Rhinosinusitis (ExpRess): Protocol for a cohort study

BACKGROUND: Chronic Rhinosinusitis (CRS) affects approximately 1 in 10 UK adults and impacts quality of life quality of life significantly. Response to treatment may be driven by individual CRS endotypes and therefore work to delineate biomarker clusters that may separate responders from non-responders is needed. The ongoing MACRO three-arm parallel-group trial randomises adult CRS patients to endoscopic sinus surgery, macrolide therapy or placebo. AIM: This study aims to correlate CRS endotypes with clinical parameters from the ongoing MACRO trial, including olfactory function and outcomes in terms of response to treatment using core biomarkers sets. METHODS: Adult CRS patients enrolled into the MACRO trial will be recruited from participating UK otorhinolaryngology departments. Nasal tissue samples and swabs will be obtained in theatre or clinic from patients randomised to all three trial arms. Nasal tissue will be analysed with multiplex electrochemiluminescence for 32 cytokines including IL-5, IL-13, IgE and periostin. Bacterial swabs will be analysed using illumina miSeq 16S amplicon sequencing. Mean expression for each biomarker will be reported for treatment responder and non-responder groups. Correlation of biomarkers with MACRO trial outcome data such as endoscopic evaluation scores and quality-of-life improvement scores will be reported. DISCUSSION: Defining clear endotypes in CRS will contribute to refining patient pathways for the efficient use of clinical resources. This work may lay the groundwork for future studies to predict which patients might respond to medical or surgical therapy

The pd <--> pi+ t reaction around the Delta resonance

The pd pi+ t process has been calculated in the energy region around the Delta-resonance with elementary production/absorption mechanisms involving one and two nucleons. The isobar degrees of freedom have been explicitly included in the two-nucleon mechanism via pi-- and rho-exchange diagrams. No free parameters have been employed in the analysis since all the parameters have been fixed in previous studies on the simpler pp pi+ d process. The treatment of the few-nucleon dynamics entailed a Faddeev-based calculation of the reaction, with continuum calculations for the initial p-d state and accurate solutions of the three-nucleon bound-state equation. The integral cross-section was found to be quite sensitive to the NN interaction employed while the angular dependence showed less sensitivity. Approximately a 4% effect was found for the one-body mechanism, for the three-nucleon dynamics in the p-d channel, and for the inclusion of a large, possibly converged, number of three-body partial states, indicating that these different aspects are of comparable importance in the calculation of the spin-averaged observables.Comment: 40 Pages, RevTex, plus 5 PostScript figure

Catching Element Formation In The Act

Gamma-ray astronomy explores the most energetic photons in nature to address some of the most pressing puzzles in contemporary astrophysics. It encompasses a wide range of objects and phenomena: stars, supernovae, novae, neutron stars, stellar-mass black holes, nucleosynthesis, the interstellar medium, cosmic rays and relativistic-particle acceleration, and the evolution of galaxies. MeV gamma-rays provide a unique probe of nuclear processes in astronomy, directly measuring radioactive decay, nuclear de-excitation, and positron annihilation. The substantial information carried by gamma-ray photons allows us to see deeper into these objects, the bulk of the power is often emitted at gamma-ray energies, and radioactivity provides a natural physical clock that adds unique information. New science will be driven by time-domain population studies at gamma-ray energies. This science is enabled by next-generation gamma-ray instruments with one to two orders of magnitude better sensitivity, larger sky coverage, and faster cadence than all previous gamma-ray instruments. This transformative capability permits: (a) the accurate identification of the gamma-ray emitting objects and correlations with observations taken at other wavelengths and with other messengers; (b) construction of new gamma-ray maps of the Milky Way and other nearby galaxies where extended regions are distinguished from point sources; and (c) considerable serendipitous science of scarce events -- nearby neutron star mergers, for example. Advances in technology push the performance of new gamma-ray instruments to address a wide set of astrophysical questions.Comment: 14 pages including 3 figure

The Long-Baseline Neutrino Experiment: Exploring Fundamental Symmetries of the Universe

The preponderance of matter over antimatter in the early Universe, the dynamics of the supernova bursts that produced the heavy elements necessary for life and whether protons eventually decay --- these mysteries at the forefront of particle physics and astrophysics are key to understanding the early evolution of our Universe, its current state and its eventual fate. The Long-Baseline Neutrino Experiment (LBNE) represents an extensively developed plan for a world-class experiment dedicated to addressing these questions. LBNE is conceived around three central components: (1) a new, high-intensity neutrino source generated from a megawatt-class proton accelerator at Fermi National Accelerator Laboratory, (2) a near neutrino detector just downstream of the source, and (3) a massive liquid argon time-projection chamber deployed as a far detector deep underground at the Sanford Underground Research Facility. This facility, located at the site of the former Homestake Mine in Lead, South Dakota, is approximately 1,300 km from the neutrino source at Fermilab -- a distance (baseline) that delivers optimal sensitivity to neutrino charge-parity symmetry violation and mass ordering effects. This ambitious yet cost-effective design incorporates scalability and flexibility and can accommodate a variety of upgrades and contributions. With its exceptional combination of experimental configuration, technical capabilities, and potential for transformative discoveries, LBNE promises to be a vital facility for the field of particle physics worldwide, providing physicists from around the globe with opportunities to collaborate in a twenty to thirty year program of exciting science. In this document we provide a comprehensive overview of LBNE's scientific objectives, its place in the landscape of neutrino physics worldwide, the technologies it will incorporate and the capabilities it will possess.Comment: Major update of previous version. This is the reference document for LBNE science program and current status. Chapters 1, 3, and 9 provide a comprehensive overview of LBNE's scientific objectives, its place in the landscape of neutrino physics worldwide, the technologies it will incorporate and the capabilities it will possess. 288 pages, 116 figure

Three Warm Jupiters around Solar-analog Stars Detected with TESS*

We report the discovery and characterization of three giant exoplanets orbiting solar-analog stars, detected by the TESS space mission and confirmed through ground-based photometry and radial velocity measurements taken at La Silla observatory with FEROS. TOI-2373 b is a warm Jupiter orbiting its host star every ∼13.3 days, and is one of the most massive known exoplanet with a precisely determined mass and radius around a star similar to the Sun, with an estimated mass of m _p = ${9.3}_{-0.2}^{+0.2}\,{M}_{\mathrm{jup}}$ and a radius of r _p = ${0.93}_{-0.2}^{+0.2}\,{R}_{\mathrm{jup}}$ . With a mean density of $\rho ={14.4}_{-1.0}^{+0.9}\,{\rm{g}}\,{\mathrm{cm}}^{-3}$ , TOI-2373 b is among the densest planets discovered so far. TOI-2416 b orbits its host star on a moderately eccentric orbit with a period of ∼8.3 days and an eccentricity of e = ${0.32}_{-0.02}^{+0.02}$ . TOI-2416 b is more massive than Jupiter with m _p = ${3.0}_{-0.09}^{+0.10}\,{M}_{\mathrm{jup}}$ , however is significantly smaller with a radius of r _p = ${0.88}_{-0.02}^{+0.02},{R}_{\mathrm{jup}}$ , leading to a high mean density of $\rho ={5.4}_{-0.3}^{+0.3}\,{\rm{g}}\,{\mathrm{cm}}^{-3}$ . TOI-2524 b is a warm Jupiter near the hot Jupiter transition region, orbiting its star every ∼7.2 days on a circular orbit. It is less massive than Jupiter with a mass of m _p = ${0.64}_{-0.04}^{+0.04}\,{M}_{\mathrm{jup}}$ , and is consistent with an inflated radius of r _p = ${1.00}_{-0.03}^{+0.02}\,{R}_{\mathrm{jup}}$ , leading to a low mean density of $\rho ={0.79}_{-0.08}^{+0.08}\,{\rm{g}}\,{\mathrm{cm}}^{-3}$ . The newly discovered exoplanets TOI-2373 b, TOI-2416 b, and TOI-2524 b have estimated equilibrium temperatures of ${860}_{-10}^{+10}$ K, ${1080}_{-10}^{+10}$ K, and ${1100}_{-20}^{+20}$ K, respectively, placing them in the sparsely populated transition zone between hot and warm Jupiters

White paper on nuclear astrophysics and low energy nuclear physics Part 1: Nuclear astrophysics

This white paper informs the nuclear astrophysics community and funding agencies about the scientific directions and priorities of the field and provides input from this community for the 2015 Nuclear Science Long Range Plan. It summarizes the outcome of the nuclear astrophysics town meeting that was held on August 21–23, 2014 in College Station at the campus of Texas A&M University in preparation of the NSAC Nuclear Science Long Range Plan. It also reflects the outcome of an earlier town meeting of the nuclear astrophysics community organized by the Joint Institute for Nuclear Astrophysics (JINA) on October 9–10, 2012 Detroit, Michigan, with the purpose of developing a vision for nuclear astrophysics in light of the recent NRC decadal surveys in nuclear physics (NP2010) and astronomy (ASTRO2010). The white paper is furthermore informed by the town meeting of the Association of Research at University Nuclear Accelerators (ARUNA) that took place at the University of Notre Dame on June 12–13, 2014. In summary we find that nuclear astrophysics is a modern and vibrant field addressing fundamental science questions at the intersection of nuclear physics and astrophysics. These questions relate to the origin of the elements, the nuclear engines that drive life and death of stars, and the properties of dense matter. A broad range of nuclear accelerator facilities, astronomical observatories, theory efforts, and computational capabilities are needed. With the developments outlined in this white paper, answers to long standing key questions are well within reach in the coming decade