Geomagnetic activity and polar surface air temperature variability

Here we use the ERA-40 and ECMWF operational surface level air temperature data sets from 1957 to 2006 to examine polar temperature variations during years with different levels of geomagnetic activity, as defined by the A(p) index. Previous modeling work has suggested that NOx produced at high latitudes by energetic particle precipitation can eventually lead to detectable changes in surface air temperatures (SATs). We find that during winter months, polar SATs in years with high A(p) index are different than in years with low A(p) index; the differences are statistically significant at the 2-sigma level and range up to about +/- 4.5 K, depending on location. The temperature differences are larger when years with wintertime Sudden Stratospheric Warmings (SSWs) are excluded. We take into account solar irradiance variations, unlike previous analyses of geomagnetic effects in ERA-40 and operational data. Although we cannot conclusively show that the polar SAT patterns are physically linked by geomagnetic activity, we conclude that geomagnetic activity likely plays a role in modulating wintertime surface air temperatures. We tested our SAT results against variation in the Quasi Biennial Oscillation, the El Nino Southern Oscillation and the Southern Annular Mode. The results suggested that these were not driving the observed polar SAT variability. However, significant uncertainty is introduced by the Northern Annular Mode, and we cannot robustly exclude a chance linkage between sea surface temperature variability and geomagnetic activity

Self-Assembly of Amphiphilic Nanoparticle-Coil “Tadpole” Macromolecules

This document is the Accepted Manuscript version of a Published Work that appeared in final form in Macromolecules, copyright © American Chemical Society after peer review and technical editing by publisher. To access the final edited and published work see https://doi.org/10.1021/ma035542qNone

Atherosclerosis in Indigenous Tsimane: A Contemporary Perspective

The Horus and other research teams have found that atherosclerosis is not uncommon in ancient people through the study of their mummified remains (Murphy et al., 2003; Allam et al., 2009, 2011; Thompson et al., 2013, 2014). However, some have postulated that traditional hunter-gatherers are in some ways healthier than modern people and that they had very little atherosclerotic disease (O’Keefe et al., 2010). The aim of this study was to evaluate the burden of atherosclerosis in a population alive today but living a traditional lifestyle similar to that experienced by past populations. This led to the Tsimane Health and Life History Project Team (THLHP) (Gurven et al., 2017) and the Horus Study Team combining efforts to evaluate the prevalence and extent of coronary atherosclerosis in the Tsimane of Bolivia (Kaplan et al., 2017)

Kalb-Ramond excitations in a thick-brane scenario with dilaton

We compute the full spectrum and eigenstates of the Kalb-Ramond field in a warped non-compact Randall-Sundrum -type five-dimensional spacetime in which the ordinary four-dimensional braneworld is represented by a sine-Gordon soliton. This 3-brane solution is fully consistent with both the warped gravitational field and bulk dilaton configurations. In such a background we embed a bulk antisymmetric tensor field and obtain, after reduction, an infinite tower of normalizable Kaluza-Klein massive components along with a zero-mode. The low lying mass eigenstates of the Kalb-Ramond field may be related to the axion pseudoscalar. This yields phenomenological implications on the space of parameters, particularly on the dilaton coupling constant. Both analytical and numerical results are given.Comment: 10 pages, 13 figures, and 2 tables. Final version to appear in The European Physical Journal

Effects of early dark energy on strong cluster lensing

We use the semi-analytic method developed by Fedeli et al. for computing strong-lensing optical depths to study the statistics of gravitational arcs in four dark-energy cosmologies. Specifically, we focus on models with early dark energy and compare them to more conventional models. Merger trees are constructed for the cluster population because strong cluster lensing is amplified by factors of two to three during mergers. We find that the optical depth for gravitational arcs in the early dark-energy models is increased by up to a factor of about 3 compared to the other models because of the modified dynamics of cluster formation. In particular, the probability for gravitational arcs in high-redshift clusters is considerably increased, which may offer an explanation for the unexpectedly high lensing efficiency of distant clusters.Comment: 10 pages, 9 figures, accepted for publication on A&

Petition for Rulemaking on Short and Distort

Today, some hedge funds attack public companies for the sole purpose of inducing a short-lived panic which they can exploit for profit. This sort of market manipulation harms average investors who entrust financial markets with their retirement savings. While short selling serves a critical function in the capital markets, some short sellers disseminate negative opinion about a company, inducing a panic and sharp decline in the stock price, and rapidly close that position for a profit prior to the price partially or fully rebounding. We urge the SEC to enact two rules which will discourage manipulative short selling. The petition for rule-making on short and distort has been jointly signed by twelve securities law professors nationwide

Chemical data assimilation estimates of continental U.S. ozone and nitrogen budgets during the Intercontinental Chemical Transport Experiment-North America

Global ozone analyses, based on assimilation of stratospheric profile and ozone column measurements, and NOy predictions from the Real-time Air Quality Modeling System (RAQMS) are used to estimate the ozone and NOy budget over the continental United States during the July-August 2004 Intercontinental Chemical Transport Experiment-North America (INTEX-A). Comparison with aircraft, satellite, surface, and ozonesonde measurements collected during INTEX-A show that RAQMS captures the main features of the global and continental U.S. distribution of tropospheric ozone, carbon monoxide, and NOy with reasonable fidelity. Assimilation of stratospheric profile and column ozone measurements is shown to have a positive impact on the RAQMS upper tropospheric/lower stratosphere ozone analyses, particularly during the period when SAGE III limb scattering measurements were available. Eulerian ozone and NOy budgets during INTEX-A show that the majority of the continental U.S. export occurs in the upper troposphere/lower stratosphere poleward of the tropopause break, a consequence of convergence of tropospheric and stratospheric air in this region. Continental U.S. photochemically produced ozone was found to be a minor component of the total ozone export, which was dominated by stratospheric ozone during INTEX-A. The unusually low photochemical ozone export is attributed to anomalously cold surface temperatures during the latter half of the INTEX-A mission, which resulted in net ozone loss during the first 2 weeks of August. Eulerian NOy budgets are shown to be very consistent with previously published estimates. The NOy export efficiency was estimated to be 24%, with NOx + PAN accounting for 54% of the total NOy export during INTEX-A. Copyright 2007 by the American Geophysical Union

Assessment of Diversity of Antimicrobial Resistance Phenotypes and Genotypes of \u3ci\u3eMannheimia haemolytica\u3c/i\u3e Isolates from Bovine Nasopharyngeal Swabs

The threat of bovine respiratory disease (BRD) for cattle operations is exacerbated by increasing prevalence of antimicrobial resistance (AMR) in Mannheimia haemolytica, a leading cause of BRD. Characterization of AMR in M. haemolytica by culture and susceptibility testing is complicated by uncertainty regarding the number of colonies that must be selected to accurately characterize AMR phenotypes (antibiograms) and genotypes in a culture. The study objective was to assess phenotypic and genotypic diversity of M. haemolytica isolates on nasopharyngeal swabs (NPS) from 28 cattle at risk for BRD or with BRD. NPS were swabbed onto five consecutive blood agar plates; after incubation up to 20 M. haemolytica colonies were selected per plate (up to 100 colonies per NPS). Phenotype was determined by measuring minimum inhibitory concentrations (MIC) for 11 antimicrobials and classifying isolates as resistant or not. Genotype was indirectly determined by matrix-assisted laser desorption/ionization time of flight mass spectroscopy (MALDI-TOF MS). NPS from 11 of 28 cattle yielded at least one M. haemolytica isolate; median (range) of isolates per NPS was 48 (1–94). NPS from seven cattle yielded one phenotype, 3 NPS yielded two, and 1 NPS yielded three; however, within a sample all phenotypic differences were due to only oneMIC dilution. On each NPS all M. haemolytica isolated were the same genotype; genotype 1 was isolated from three NPS and genotype two was isolated from eight. Diversity of M. haemolytica on bovine NPS was limited, suggesting that selection of few colonies might adequately identify relevant phenotypes and genotypes