The Role of Cold Flows in the Assembly of Galaxy Disks

We use high resolution cosmological hydrodynamical simulations to demonstrate that cold flow gas accretion, particularly along filaments, modifies the standard picture of gas accretion and cooling onto galaxy disks. In the standard picture, all gas is initially heated to the virial temperature of the galaxy as it enters the virial radius. Low mass galaxies are instead dominated by accretion of gas that stays well below the virial temperature, and even when a hot halo is able to develop in more massive galaxies there exist dense filaments that penetrate inside of the virial radius and deliver cold gas to the central galaxy. For galaxies up to ~L*, this cold accretion gas is responsible for the star formation in the disk at all times to the present. Even for galaxies at higher masses, cold flows dominate the growth of the disk at early times. Within this modified picture, galaxies are able to accrete a large mass of cold gas, with lower initial gas temperatures leading to shorter cooling times to reach the disk. Although star formation in the disk is mitigated by supernovae feedback, the short cooling times allow for the growth of stellar disks at higher redshifts than predicted by the standard model.Comment: accepted to Ap

Comparison of Risk of Recrudescent Fever in Children With Kawasaki Disease Treated With Intravenous Immunoglobulin and Low-Dose vs High-Dose Aspirin

Importance: Timely initiation of intravenous immunoglobulin plus aspirin is necessary for decreasing the risk of recrudescent fever and coronary artery abnormalities in children with Kawasaki disease (KD). The optimal dose of aspirin, however, remains unclear. Objective: To evaluate whether initial treatment with low-dose compared with high-dose aspirin in children with KD is associated with an increase in fever recrudescence. Design, Setting, and Participants: A retrospective cohort study of 260 children with KD at Riley Hospital for Children, Indianapolis, Indiana, between January 1, 2007, and December 31, 2018, was conducted. Children aged 0 to 18 years with a first episode of KD, identified by International Classification of Diseases, Ninth Revision and International Statistical Classification of Diseases and Related Health Problems, Tenth Revision diagnosis codes treated within 10 days of symptom onset with high-dose intravenous immunoglobulin plus aspirin were eligible. Patients who received an alternative diagnosis, experienced a second episode of KD, did not receive intravenous immunoglobulin plus aspirin for initial treatment, were not treated within 10 days of symptoms, or had incomplete records were excluded. Exposures: High-dose (≥10 mg/kg/d) or low-dose (<10 mg/kg/d) aspirin therapy. Main Outcomes and Measures: The primary outcome was recrudescent fever necessitating retreatment of KD. The secondary outcomes were coronary artery abnormalities and hospital length of stay. Results: Among the 260 patients included, the median (interquartile range) age was 2.5 (1.6-4.3) years, 103 (39.6%) were girls, 166 (63.8%) were non-Hispanic white, 57 (21.9%) were African American, 22 (8.5%) were Asian, 11 (4.2%) were Hispanic, and 4 (1.5%) were of unknown race/ethnicity. One hundred-forty-two patients (54.6%) were treated with low-dose aspirin. There was no association between recrudescent fever and aspirin dose, with 39 children (27.5%) having recrudescent fever in the low-dose group compared with 26 children (22.0%) in the high-dose group (odds ratio [OR], 1.34; 95% CI, 0.76-2.37; P = .31), with similar results after adjusting for potential confounding variables (OR, 1.63; 95% CI, 0.89-2.97; P = .11). In a subset analysis of 167 children with complete KD, however, there was nearly a 2-fold difference in the odds of recrudescent fever with low-dose aspirin (OR, 1.87; 95% CI, 0.82-4.23; P = .14), although this difference did not reach statistical significance. In addition, no association was identified between treatment group and coronary artery abnormalities (low-dose, 7.4% vs high-dose, 9.4%; OR, 0.86; 95% CI, 0.48-1.55; P = .62) or median (interquartile range) length of stay (3 [3-5] days for both groups; P = .27). Conclusions and Relevance: In this study, low-dose aspirin for the initial treatment of children with KD was not associated with fever recrudescence or coronary artery abnormalities. Given the potential benefits, further study of low-dose aspirin to detect potentially clinically relevant outcome differences is warranted to inform treatment decisions and guideline development

Keeping up with the Times: Improving the Modern Counselor through Professional Identity Development, Technological Policy, and Positive Risk Taking

Awareness of ‘best practices’ and ‘critical issues’ assists counselors-in-training as they attempt to navigate the expectations of their programs and prepare for their future careers. This article identified the development of a professional identity as a significant goal for counselors-in-training and a curriculum responsibility for counselor educators. The authors also identified two critical issues that counselors-in-training and working professionals face currently. The first critical issue addressed is how technologies fit into counseling practices and their impact on the counseling process. The second critical issue is the potential impact of counselor-client willingness to take a risk with therapeutic options. New and seasoned counselors alike will be met with challenges as they develop and grow in their professional identity. Counselors can support their own professional development by understanding ‘critical issues’ that have the potential to impact professional identity as well as gleaning the knowledge of ‘best practices’ for ethical decision-making

Electron density and collision frequency of microwave‐resonant‐cavity‐produced discharges

A review of perturbation diagnostics applied to microwave resonant cavity discharges is presented. The classical microwave perturbation technique examines the shift in the resonant frequency and cavity quality factor of the resonant cavity caused by low‐electron density discharges. However, the modifications presented allow the analysis to be applied to discharges with electron densities beyond the limit predicted by perturbation theory. An ‘‘exact’’ perturbation analysis is presented which models the discharge as a separate dielectric, thereby removing the restrictions on electron density imposed by the classical technique. The ‘‘exact’’ method also uses measurements of the shifts in the resonant conditions of the cavity. Third, an electromagnetic analysis is presented which uses a characteristic equation, based upon Maxwell’s laws, and predicts the discharge conductivity based upon measurements of a complex axial wave number. By allowing the axial wave number of the electromagnetic fields to be complex, the fields are experimentally and theoretically shown to be spatially attenuated. The diagnostics are applied to continuous‐wave microwave (2.45 GHz) discharges produced in an Asmussen resonant cavity. Double Langmuir probes, placed directly in the discharge at the point where the radial electric field is zero, act as a comparison with the analytic diagnostics. Microwave powers ranging from 30 to 100 W produce helium and nitrogen discharges with pressures ranging from 0.5 to 6 Torr. Analysis of the data predicts electron temperatures from 5 to 20 eV, electron densities from 1011 to 3×1012 cm−3, and collision frequencies from 109 to 1011 s−1.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/69731/2/JAPIAU-74-6-3724-1.pd

Functional modes of proteins are among the most robust ones

It is shown that a small subset of modes which are likely to be involved in protein functional motions of large amplitude can be determined by retaining the most robust normal modes obtained using different protein models. This result should prove helpful in the context of several applications proposed recently, like for solving difficult molecular replacement problems or for fitting atomic structures into low-resolution electron density maps. Moreover, it may also pave the way for the development of methods allowing to predict such motions accurately.Comment: 4 pages, 5 figure

Towards the Refinement of Von Neumann Machines

Mathematicians agree that certifiable configurations are an interesting new topic in the field of programming languages, and scholars concur. Given the current status of atomic modalities, programmers dubiously desire the synthesis of replication. In or- der to accomplish this intent, we describe a distributed tool for analyzing context-free grammar (Tor), verifying that the little- known collaborative algorithm for the em- ulation of the Internet by M. Garey et al. [3] is in Co-NP

Slow Proton Production in Semi-Inclusive Deep Inelastic Scattering off Deuteron and Complex Nuclei: Hadronization and Final State Interaction Effects

The effects of the final state interaction in slow proton production in semi inclusive deep inelastic scattering processes off nuclei, A(e,e'p)X, are investigated in details within the spectator and target fragmentation mechanisms; in the former mechanism, the hard interaction on a nucleon of a correlated pair leads, by recoil, to the emission of the partner nucleon, whereas in the latter mechanism proton is produced when the diquark, which is formed right after the visrtual photon-quark interaction, captures a quark from the vacuum. Unlike previous papers on the subject, particular attention is paid on the effects of the final state interaction of the hadronizing quark with the nuclear medium within an approach based upon an effective time-dependent cross section which combines the soft and hard parts of hadronization dynamics in terms of the string model and perturbative QCD, respectively. It is shown that the final state interaction of the hadronizing quark with the medium plays a relevant role both in deuteron and complex nuclei; nonetheless, kinematical regions where final state interaction effects are minimized can experimentally be selected, which would allow one to investigate the structure functions of nucleons embedded in the nuclear medium; likewise, regions where the interaction of the struck hadronizing quark with the nuclear medium is maximized can be found, which would make it possible to study non perturbative hadronization mechanisms.Comment: 35 pages, 12 figures, accepted for pubblication in Phys. Rev.

Tunable Cavity Optomechanics with Ultracold Atoms

We present an atom-chip-based realization of quantum cavity optomechanics with cold atoms localized within a Fabry-Perot cavity. Effective sub-wavelength positioning of the atomic ensemble allows for tuning the linear and quadratic optomechanical coupling parameters, varying the sensitivity to the displacement and strain of a compressible gaseous cantilever. We observe effects of such tuning on cavity optical nonlinearity and optomechanical frequency shifts, providing their first characterization in the quadratic-coupling regime.Comment: 4 pages, 5 figure

A Comparison of Faculty and Undergraduate Students\u27 Perceptions of Online Courses and Degree Programs

Many colleges and universities are currently offering online courses and even complete online degree programs, and many others are developing or considering plans to do so. The perceptions of those who are potential subscribers to these programs as well as those who will deliver these programs will be critical to their success. This paper investigates the perceptions of current undergraduate students and college business professors toward online courses and degree programs along several dimensions. Perceptions of college professors toward these programs are significantly less favorable than are the perceptions of college students. The dimensions of these perceptions are explored to provide guidance regarding delivery of online programs