Effective Rheology of Bubbles Moving in a Capillary Tube

We calculate the average volumetric flux versus pressure drop of bubbles moving in a single capillary tube with varying diameter, finding a square-root relation from mapping the flow equations onto that of a driven overdamped pendulum. The calculation is based on a derivation of the equation of motion of a bubble train from considering the capillary forces and the entropy production associated with the viscous flow. We also calculate the configurational probability of the positions of the bubbles.Comment: 4 pages, 1 figur

Performance of the CMS Cathode Strip Chambers with Cosmic Rays

The Cathode Strip Chambers (CSCs) constitute the primary muon tracking device in the CMS endcaps. Their performance has been evaluated using data taken during a cosmic ray run in fall 2008. Measured noise levels are low, with the number of noisy channels well below 1%. Coordinate resolution was measured for all types of chambers, and fall in the range 47 microns to 243 microns. The efficiencies for local charged track triggers, for hit and for segments reconstruction were measured, and are above 99%. The timing resolution per layer is approximately 5 ns

New Pharmacological Agents to Aid Smoking Cessation and Tobacco Harm Reduction: What has been Investigated and What is in the Pipeline?

A wide range of support is available to help smokers to quit and aid attempts at harm reduction, including three first-line smoking cessation medications: nicotine replacement therapy, varenicline and bupropion. Despite the efficacy of these, there is a continual need to diversify the range of medications so that the needs of tobacco users are met. This paper compares the first-line smoking cessation medications to: 1) two variants of these existing products: new galenic formulations of varenicline and novel nicotine delivery devices; and 2) twenty-four alternative products: cytisine (novel outside of central and eastern Europe), nortriptyline, other tricyclic antidepressants, electronic cigarettes, clonidine (an anxiolytic), other anxiolytics (e.g. buspirone), selective 5-hydroxytryptamine (5-HT) reuptake inhibitors, supplements (e.g. St John’s wort), silver acetate, nicobrevin, modafinil, venlafaxine, monoamine oxidase inhibitors (MAOI), opioid antagonist, nicotinic acetylcholine receptors (nAChR) antagonists, glucose tablets, selective cannabinoid type 1 receptor antagonists, nicotine vaccines, drugs that affect gamma-aminobutyric acid (GABA) transmission, drugs that affect N-methyl-D-aspartate receptors (NMDA), dopamine agonists (e.g. levodopa), pioglitazone (Actos; OMS405), noradrenaline reuptake inhibitors, and the weight management drug lorcaserin. Six criteria are used: relative efficacy, relative safety, relative cost, relative use (overall impact of effective medication use), relative scope (ability to serve new groups of patients), and relative ease of use (ESCUSE). Many of these products are in the early stages of clinical trials, however, cytisine looks most promising in having established efficacy and safety and being of low cost. Electronic cigarettes have become very popular, appear to be efficacious and are safer than smoking, but issues of continued dependence and possible harms need to be considered

Search for new physics in the multijet and missing transverse momentum final state in proton-proton collisions at √s=8 Tev

Peer reviewe

Multi-messenger observations of a binary neutron star merger

On 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of ~1.7 s with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg2 at a luminosity distance of 40+8-8 Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 Mo. An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at ~40 Mpc) less than 11 hours after the merger by the One- Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ~10 days. Following early non-detections, X-ray and radio emission were discovered at the transient’s position ~9 and ~16 days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta

Policy Coherence in US Tobacco Control: Beyond FDA Regulation

Joshua Yang and Thomas Novotny explore whether the US government can develop and implement a coherent policy agenda to reduce tobacco-related morbidity and mortality

Measurement of Higgs boson production and properties in the WW decay channel with leptonic final states

Peer reviewe

Study of hadronic event-shape variables in multijet final states in pp collisions at √s=7 TeV

Peer reviewe

Long-term outcomes of sutureless and rapid-deployment aortic valve replacement: A systematic review and meta-analysis

Background: Sutureless and rapid-deployment aortic valve replacement (SURD-AVR) has become a prominent area of research as the medical community evaluate its place amongst other aortic valve interventions. The main advantages of SURD-AVR established to date are the reduced cross-clamp and cardiopulmonary bypass (CPB) times, as well as facilitating minimally invasive surgery in high-risk surgical patients. This current systematic review and meta-analysis, to our knowledge, is the first focusing on long-term outcomes regarding safety, efficacy and durability of SURD-AVR from available current literature. Methods: A literature search via six electronic databases was performed from their inception to November 2019. Inclusion criteria for this systematic review included survival and postoperative echocardiographic outcomes greater than five years in patients who underwent SURD-AVR with either Perceval or Intuity valves. Studies were identified and data extracted by two independent reviewers. Long-term survival outcomes were aggregated using digitized Kaplan-Meier curves where available. Results: After applying predefined inclusion and exclusion criteria, four studies were identified for review. All four studies were observational and in total reported data for 1,998 patients. Almost half (42.4%) of patients underwent SURD-AVR via full sternotomy, with almost one third (30.1%) also undergoing concomitant cardiac procedures. Aggregate overall survival rates at 1-, 2-, 3-, and 5-year follow-up were 94.9%, 91.2%, 89.0%, and 84.2%, respectively. Incidence of strokes (4.8%), severe paravalvular leaks (PVLs) (1.5%) and permanent pacemaker (PPM) insertion (8.2%) at up to 5-year follow-up were acceptable. At 5-year follow-up hemodynamic outcomes were also acceptable for mean pressure gradient (MPG) (range, 8.8-13.6 mmHg), peak pressure gradient (PPG) (range, 18.9-21.1 mmHg) and effective orifice area (EOA) (range, 1.5-1.8 cm2). Conclusions: Evaluation of the evidence reporting long-term outcomes of SURD-AVR suggests that it is a safe procedure for AVR with low rates of complications. Long-term outcomes presented in this review show that not only does SURD-AVR have acceptable survival rates, but also good hemodynamic performance at 5-year follow-up

Constraints on parton distribution functions and extraction of the strong coupling constant from the inclusive jet cross section in pp collisions at √s=7 TeV

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