Exploring the origins of the Dzyalloshinski-Moria interaction in MnSi

By using magnetization and small-angle neutron scattering (SANS) measurements, we have investigated the magnetic behavior of Mn_{1-x}Ir_{x}Si system to explore the effect of increased carrier density and spin-orbit interaction on the magnetic properties of MnSi. We determine estimates of the spin wave stiffness and the Dzyalloshinski-Moria, DM, interaction strength and compare with Mn_{1-x}Co_{x}Si and Mn_{1-x}Fe_{x}Si. Despite the large differences in atomic mass and size of the substituted elements, Mn_{1-x}Co_{x}Si and Mn_{1-x}Ir_{x}Si show nearly identical variations in their magnetic properties with substitution. We find a systematic dependence of the transition temperature, the ordered moment, the helix period and the DM interaction strength with electron count for Mn{1-x}Ir{x}Si, Mn_{1-x}Co_{x}Si, and Mn_{1-x}Fe_{x}Si indicating that the magnetic behavior is primarily dependent upon the additional carrier density rather than on the mass or size of the substituting species. This indicates that the variation in magnetic properties, including the DM interaction strength, are primarily controlled by the electronic structure as Co and Ir are isovalent. Our work suggests that although the rigid band model of electronic structure along with Moira's model of weak itinerant magnetism describe this system surprisingly well, phenomenological models for the DM interaction strength are not adequate to describe this system.Comment: 17 pages, 7 Figure

Probing Λ\LambdaCDM cosmology with the Evolutionary Map of the Universe survey

The Evolutionary Map of the Universe (EMU) is an all-sky survey in radio-continuum which uses the Australian SKA Pathfinder (ASKAP). Using galaxy angular power spectrum and the integrated Sachs-Wolfe effect, we study the potential of EMU to constrain models beyond $\Lambda$CDM (i.e., local primordial non-Gaussianity, dynamical dark energy, spatial curvature and deviations from general relativity), for different design sensitivities. We also include a multi-tracer analysis, distinguishing between star-forming galaxies and galaxies with an active galactic nucleus, to further improve EMU's potential. We find that EMU could measure the dark energy equation of state parameters around 35\% more precisely than existing constraints, and that the constraints on $f_{\rm NL}$ and modified gravity parameters will improve up to a factor $\sim2$ with respect to Planck and redshift space distortions measurements. With this work we demonstrate the promising potential of EMU to contribute to our understanding of the Universe.Comment: 15 pages (29 with references and appendices), 6 figures and 10 tables. Matches the published version. Minimal changes from previous versio

Evaluation of a Vivo-Morpholino Delivery Method to the Brain and the Affect on Physical Activity

Evaluation of a Vivo-Morpholino Delivery Method to the Brain and the Affect on Physical Activity *David P. Ferguson MS, Emily E. Schmitt MS, J. Timothy Lightfoot PhD FACSM Biology of Physical Activity Lab, Texas A&M University, College Station, TX, 77843 *To be judged in the doctoral category Physical inactivity has been shown to be correlated to various disease and conditions. Therefore, there is interest in the genetic mechanisms that control daily physical activity. Vivo-morpholinos are a new molecular biology tool that allows for the transient silencing of specific genes in an animal model, thereby allowing for a systematic method to turn off potential candidate genes involved in the regulation of physical activity. Vivo-morpholinos have not been shown to be effective at silencing genes in the brain due to the fact that the vivo-morpholino cannot cross the blood brain barrier. To counteract this, a tail vein injection (55 ul total volume; 11mg/kg vivo-morpholino; 6.5ug/kg RMP7) was given on three consecutive days containing the bradykinin analog RMP7 and a vivo-morpholino targeting Vmat2 to male C57/LJ mice (n=6). RMP7 has been shown to increase blood brain barrier permeability while Vmat2 is a dopamine transporter and is thought to be involved in the regulation of voluntary physical activity. Control animals received either RMP7 plus saline (n=6) or RMP7 plus a vivo-morpholino “scramble” control (n=6). Physical activity was measured by wheel running. Results showed there was not a significant (p=0.24) knockdown in Vmat2 in the brain with RMP7 administration as compared to control animals. Interestingly there was a significant (p=0.001) knockdown in daily physical activity in the Vmat2 treated animals compared to the control group. RMP7 may still be a viable option for vivo-morpholino delivery in the brain; however an increased dosage may be required

Mosaic Brains? A Methodological Critique of Joel et al. (2015)

(no abstract

Probing Λ\LambdaCDM cosmology with the Evolutionary Map of the Universe survey

The Evolutionary Map of the Universe (EMU) is an all-sky survey in radio-continuum which uses the Australian SKA Pathfinder (ASKAP). Using galaxy angular power spectrum and the integrated Sachs-Wolfe effect, we study the potential of EMU to constrain models beyond $\Lambda$CDM (i.e., local primordial non-Gaussianity, dynamical dark energy, spatial curvature and deviations from general relativity), for different design sensitivities. We also include a multi-tracer analysis, distinguishing between star-forming galaxies and galaxies with an active galactic nucleus, to further improve EMU's potential. We find that EMU could measure the dark energy equation of state parameters around 35\% more precisely than existing constraints, and that the constraints on $f_{\rm NL}$ and modified gravity parameters will improve up to a factor $\sim2$ with respect to Planck and redshift space distortions measurements. With this work we demonstrate the promising potential of EMU to contribute to our understanding of the Universe.Comment: 15 pages (29 with references and appendices), 6 figures and 10 tables. Matches the published version. Minimal changes from previous versio

Universal sex differences in the desire for sexual variety: tests from 52 nations, 6 Continents, and 13 Islands

Evolutionary psychologists have hypothesized that men and women possess both long-term and short-term mating strategies, with men's short-term strategy differentially rooted in the desire for sexual variety. In this article, findings from a cross-cultural survey of 16,288 people across 10 major world regions (including North America, South America, Western Europe, Eastern Europe, Southern Europe, Middle East, Africa, Oceania, South/Southeast Asia, and East Asia) demonstrate that sex differences in the desire for sexual variety are culturally universal throughout these world regions. Sex differences were evident regardless of whether mean, median, distributional, or categorical indexes of sexual differentiation were evaluated. Sex differences were evident regardless of the measures used to evaluate them. Among contemporary theories of human mating, pluralistic approaches that hypothesize sex differences in the evolved design of short-term mating provide the most compelling account of these robust empirical findings

The Antihero in Popular Culture: A Life History Theory of the Dark Triad

The Dark Triad of personality is composed of narcissism, psychopathy, and Machiavellianism. Despite the common belief that these traits are undesirable, the media is awash with characters that embody the Dark Triad. Characters like Gregory House, M.D., Batman (a.k.a. the Dark Knight), and James Bond all embody these traits and are some of the most popular media franchises today. As entertaining as these characters are, they provide us with a window into the dark side of human nature. Instead of treating the dark side of human nature as inherently maladaptive, we provide an alternative view that, despite their costs, traits like these can confer reproductive and survival benefits for the individual. In so doing, we review the research on the Dark Triad traits and provide a theoretical account for how these traits can confer some positive benefits. To facilitate comprehension, we provide examples taken from the media to show how evolutionary psychology and popular culture intersect