Coexistence and Phase Separation in Sheared Complex Fluids

We demonstrate how to construct dynamic phase diagrams for complex fluids that undergo transitions under flow, in which the conserved composition variable and the broken-symmetry order parameter (nematic, smectic, crystalline, etc.) are coupled to shear rate. Our construction relies on a selection criterion, the existence of a steady interface connecting two stable homogeneous states. We use the (generalized) Doi model of lyotropic nematic liquid crystals as a model system, but the method can be easily applied to other systems, provided non-local effects are included.Comment: 4 pages REVTEX, 5 figures using epsf macros. To appear in Physical Review E (Rapid Communications

Stress transmission in wet granular materials

We analyze stress transmission in wet granular media in the pendular state by means of three-dimensional molecular dynamics simulations. We show that the tensile action of capillary bonds induces a self-stressed particle network organized in two percolating "phases" of positive and negative particle pressures. Various statistical descriptors of the microstructure and bond force network are used to characterize this partition. Two basic properties emerge: 1) The highest particle pressure is located in the bulk of each phase; 2) The lowest pressure level occurs at the interface between the two phases, involving also the largest connectivity of the particles via tensile and compressive bonds. When a confining pressure is applied, the number of tensile bonds falls off and the negative phase breaks into aggregates and isolated sites

Phase Separation of Rigid-Rod Suspensions in Shear Flow

We analyze the behavior of a suspension of rigid rod-like particles in shear flow using a modified version of the Doi model, and construct diagrams for phase coexistence under conditions of constant imposed stress and constant imposed strain rate, among paranematic, flow-aligning nematic, and log-rolling nematic states. We calculate the effective constitutive relations that would be measured through the regime of phase separation into shear bands. We calculate phase coexistence by examining the stability of interfacial steady states and find a wide range of possible ``phase'' behaviors.Comment: 23 pages 19 figures, revised version to be published in Physical Review

Experimental Study of the Behavior of the Bjorken Sum at Very Low Q²

We present new data on the Bjorken sum -Γ p-n1 (Q2) at 4-momentum transfer 0.021 ≤ Q2 ≤ 0.496 GeV2. The data were obtained in two experiments performed at Jefferson Lab: EG4 on polarized protons and deuterons, and E97110 on polarized 3He from which neutron data were extracted. The data cover the domain where chiral effective field theory (χEFT), the leading effective theory of the Strong Force at large distances, is expected to be applicable. We find that our data and the predictions from χEFT are only in marginal agreement. This is somewhat surprising as the contribution from the Δ(1232) resonance is suppressed in this observable, which should make it more reliably predicted by χEFT than quantities in which the Δ contribution is important. The data are also compared to a number of phenomenological models with various degrees of agreement

Experimental Study of the Behavior of the Bjorken Sum at Very Low Q²

We present new data on the Bjorken sum -Γ p-n1 (Q2) at 4-momentum transfer 0.021 ≤ Q2 ≤ 0.496 GeV2. The data were obtained in two experiments performed at Jefferson Lab: EG4 on polarized protons and deuterons, and E97110 on polarized 3He from which neutron data were extracted. The data cover the domain where chiral effective field theory (χEFT), the leading effective theory of the Strong Force at large distances, is expected to be applicable. We find that our data and the predictions from χEFT are only in marginal agreement. This is somewhat surprising as the contribution from the Δ(1232) resonance is suppressed in this observable, which should make it more reliably predicted by χEFT than quantities in which the Δ contribution is important. The data are also compared to a number of phenomenological models with various degrees of agreement

Family Planning and the Millennium Development Goals

The United Nations' (UN's) eight Millennium Development Goals (MDGs) (1) are widely accepted as the primary path to alleviating poverty worldwide. This month, world leaders convene to assess progress toward these goals (2). In the countdown to the MDG 2015 deadline and amid protracted economic recession, we need the most efficient, effective, and evidence-based means to accelerate progress toward all MDGs. Challenges must be considered in concert, and solutions must provide multidimensional dividends for the world's poor, or we risk unwisely dividing limited resources and diluting their impact. As authors from diverse communities, we emphasize here the influence that investments in rights-based family planning can have on achieving the MDGs

Microbial ligand costimulation drives neutrophilic steroid-refractory asthma

Funding: The authors thank the Wellcome Trust (102705) and the Universities of Aberdeen and Cape Town for funding. This research was also supported, in part, by National Institutes of Health GM53522 and GM083016 to DLW. KF and BNL are funded by the Fonds Wetenschappelijk Onderzoek, BNL is the recipient of an European Research Commission consolidator grant and participates in the European Union FP7 programs EUBIOPRED and MedALL. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer reviewedPublisher PD

Delayed antibiotics for respiratory infections

Background: Concerns exist regarding antibiotic prescribing for acute respiratory tract infections (ARTIs) owing to adverse reactions, cost and antibacterial resistance. One strategy to reduce antibiotic prescribing is to provide prescriptions but to advise delay in the hope symptoms will resolve first. This is an update of a Cochrane Review originally published in 2007 and updated in 2010. Objectives: To evaluate the use of delayed antibiotics compared to immediate or no antibiotics as a prescribing strategy for ARTIs. We evaluated clinical outcomes including duration and severity measures for pain, malaise, fever, cough and rhinorrhoea in sore throat, acute otitis media, bronchitis (cough) and the common cold. We also evaluated the outcomes of antibiotic use, patient satisfaction, antibiotic resistance and re-consultation rates and use of alternative therapies. Search methods: We searched CENTRAL (The Cochrane Library 2013, Issue 2), which includes the Acute Respiratory Infection Group's Specialised Register; Ovid MEDLINE (January 1966 to February Week 3 2013); Ovid MEDLINE In-Process & Other Non-Indexed Citations (28 February 2013); EMBASE (1990 to 2013 Week 08); Science Citation Index - Web of Science (2007 to May 2012) and EBSCO CINAHL (1982 to 28 February 2013). Selection criteria: Randomised controlled trials (RCTs) involving participants of all ages defined as having an ARTI, where delayed antibiotics were compared to antibiotics used immediately or no antibiotics. Data collection and analysis: Three review authors independently extracted and collected data. Important adverse effects, including adverse effects of antibiotics and complications of disease, were included as secondary outcomes. We assessed the risk of bias of all included trials. We contacted trial authors to obtain missing information where available. Main results: Ten studies, with a total of 3157 participants, were included in this review. Heterogeneity of the 10 included studies and their results generally precluded meta-analysis with patient satisfaction being an exception. There was no difference between delayed, immediate and no prescribed antibiotics for the clinical outcomes evaluated in cough and common cold. In patients with acute otitis media (AOM) and sore throat immediate antibiotics were more effective than delayed for fever, pain and malaise in some studies. There were only minor differences in adverse effects with no significant difference in complication rates. Delayed antibiotics resulted in a significant reduction in antibiotic use compared to immediate antibiotics. A strategy of no antibiotics resulted in least antibiotic use. Patient satisfaction favoured immediate antibiotics over delayed (odds ratio (OR) 0.52; 95% confidence interval (CI) 0.35 to 0.76). Delayed and no antibiotics had similar satisfaction rates with both strategies achieving over 80% satisfaction (OR 1.44; 95% CI 0.99 to 2.10). There was no difference in re-consultation rates for immediate and delayed groups. None of the included studies evaluated antibiotic resistance. Authors' conclusions: Most clinical outcomes show no difference between strategies. Delay slightly reduces patient satisfaction compared to immediate antibiotics (87% versus 92%) but not compared to none (87% versus 83%). In patients with respiratory infections where clinicians feel it is safe not to prescribe antibiotics immediately, no antibiotics with advice to return if symptoms do not resolve is likely to result in the least antibiotic use, while maintaining similar patient satisfaction and clinical outcomes to delayed antibiotics

A Precision Measurement of the Neutron Twist-3 Matrix Element d2nd_2^n: Probing Color Forces

Double-spin asymmetries and absolute cross sections were measured at large Bjorken $x$ (0.25 $\le x \le$ 0.90), in both the deep-inelastic and resonance regions, by scattering longitudinally polarized electrons at beam energies of 4.7 and 5.9 GeV from a transversely and longitudinally polarized $^3$He target. In this dedicated experiment, the spin structure function $g_2$ on $^3$He was determined with precision at large $x$, and the neutron twist-three matrix element $d_2^n$ was measured at \left of 3.21 and 4.32 GeV$^2$/$c^2$, with an absolute precision of about $10^{-5}$. Our results are found to be in agreement with lattice QCD calculations and resolve the disagreement found with previous data at \left = 5 GeV$^2$/$c^2$. Combining $d_2^n$ and a newly extracted twist-four matrix element, $f_2^n$, the average neutron color electric and magnetic forces were extracted and found to be of opposite sign and about 30 MeV/fm in magnitude.Comment: Corrected a typo in the author list and Figure 1 legend. 6 pages, 2 figures, 2 table