Partisan Asymmetries in Online Political Activity

We examine partisan differences in the behavior, communication patterns and social interactions of more than 18,000 politically-active Twitter users to produce evidence that points to changing levels of partisan engagement with the American online political landscape. Analysis of a network defined by the communication activity of these users in proximity to the 2010 midterm congressional elections reveals a highly segregated, well clustered partisan community structure. Using cluster membership as a high-fidelity (87% accuracy) proxy for political affiliation, we characterize a wide range of differences in the behavior, communication and social connectivity of left- and right-leaning Twitter users. We find that in contrast to the online political dynamics of the 2008 campaign, right-leaning Twitter users exhibit greater levels of political activity, a more tightly interconnected social structure, and a communication network topology that facilitates the rapid and broad dissemination of political information.Comment: 17 pages, 10 figures, 6 table

Local correlations in a strongly interacting 1D Bose gas

We develop an analytical method for calculating local correlations in strongly interacting 1D Bose gases, based on the exactly solvable Lieb-Liniger model. The results are obtained at zero and finite temperatures. They describe the interaction-induced reduction of local many-body correlation functions and can be used for achieving and identifying the strong-coupling Tonks-Girardeau regime in experiments with cold Bose gases in the 1D regime.Comment: 8 pages, REVTeX4, published in the New Journal of Physic

Spontaneous symmetry breaking in the non-linear Schrodinger hierarchy with defect

We introduce and solve the one-dimensional quantum non-linear Schrodinger (NLS) equation for an N-component field defined on the real line with a defect sitting at the origin. The quantum solution is constructed using the quantum inverse scattering method based on the concept of Reflection-Transmission (RT) algebras recently introduced. The symmetry of the model is generated by the reflection and transmission defect generators defining a defect subalgebra. We classify all the corresponding reflection and transmission matrices. This provides the possible boundary conditions obeyed by the canonical field and we compute these boundary conditions explicitly. Finally, we exhibit a phenomenon of spontaneous symmetry breaking induced by the defect and identify the unbroken generators as well as the exact remaining symmetry.Comment: discussion on symmetry breaking has been improved and examples adde

The quantum non-linear Schrodinger model with point-like defect

We establish a family of point-like impurities which preserve the quantum integrability of the non-linear Schrodinger model in 1+1 space-time dimensions. We briefly describe the construction of the exact second quantized solution of this model in terms of an appropriate reflection-transmission algebra. The basic physical properties of the solution, including the space-time symmetry of the bulk scattering matrix, are also discussed.Comment: Comments on the integrability and the impurity free limit adde

Universal correlations of trapped one-dimensional impenetrable bosons

We calculate the asymptotic behaviour of the one body density matrix of one-dimensional impenetrable bosons in finite size geometries. Our approach is based on a modification of the Replica Method from the theory of disordered systems. We obtain explicit expressions for oscillating terms, similar to fermionic Friedel oscillations. These terms are universal and originate from the strong short-range correlations between bosons in one dimension.Comment: 18 pages, 3 figures. Published versio

Core components for effective infection prevention and control programmes: new WHO evidence-based recommendations

Abstract Health care-associated infections (HAI) are a major public health problem with a significant impact on morbidity, mortality and quality of life. They represent also an important economic burden to health systems worldwide. However, a large proportion of HAI are preventable through effective infection prevention and control (IPC) measures. Improvements in IPC at the national and facility level are critical for the successful containment of antimicrobial resistance and the prevention of HAI, including outbreaks of highly transmissible diseases through high quality care within the context of universal health coverage. Given the limited availability of IPC evidence-based guidance and standards, the World Health Organization (WHO) decided to prioritize the development of global recommendations on the core components of effective IPC programmes both at the national and acute health care facility level, based on systematic literature reviews and expert consensus. The aim of the guideline development process was to identify the evidence and evaluate its quality, consider patient values and preferences, resource implications, and the feasibility and acceptability of the recommendations. As a result, 11 recommendations and three good practice statements are presented here, including a summary of the supporting evidence, and form the substance of a new WHO IPC guideline

Increased function of pronociceptive TRPV1 at the level of the joint in a rat model of osteoarthritis pain

Objectives Blockade of transient receptor potential vanilloid 1 (TRPV1) with systemic antagonists attenuates osteoarthritis (OA) pain behaviour in rat models, but on-target-mediated hyperthermia has halted clinical trials. The present study investigated the potential for targeting TRPV1 receptors within the OA joint in order to produce analgesia. Methods The presence of TRPV1 receptors in human synovium was detected using western blotting and immunohistochemistry. In a rat model of OA, joint levels of an endogenous ligand for TRPV1, 12- ydroxyeicosatetraenoic acid (12-HETE), were quantified using liquid chromatography-tandem mass spectrometry (LCMS/MS). Effects of peripheral administration of the TRPV1 receptor antagonist JNJ-17203212 on afferent fibre activity, pain behaviour and core body temperature were investigated. Effects of a spinal administration of JNJ-17203212 on dorsal horn neuronal responses were studied. Results We demonstrate increased TRPV1 immunoreactivity in human OA synovium, confirming the diseased joint as a potential therapeutic target for TRPV1-mediated analgesia. In a model of OA pain, we report increased joint levels of 12-HETE, and the sensitisation of joint afferent neurones to mechanical stimulation of the knee. Local administration of JNJ- 17203212 reversed this sensitisation of joint afferents and inhibited pain behaviour (weight-bearing asymmetry), to a comparable extent as systemic JNJ- 17203212, in this model of OA pain, but did not alter core body temperature. There was no evidence for increased TRPV1 function in the spinal cord in this model of OA pain. Conclusions Our data provide a clinical and mechanistic rationale for the future investigation of the therapeutic benefits of intra-articular administration of TRPV1 antagonists for the treatment of OA pain

Internet-based prevention of posttraumatic stress symptoms in injured trauma patients: design of a randomized controlled trial.

Background: Injured trauma victims are at risk of developing Posttraumatic Stress Disorder (PTSD) and other post-trauma psychopathology. So far, interventions using cognitive behavioral techniques (CBT) have proven most efficacious in treating early PTSD in highly symptomatic individuals. No early intervention for the prevention of PTSD for all victims has yet proven effective. In the acute psychosocial care for trauma victims, there is a clear need for easily applicable, accessible, cost-efficient early interventions. Objective: To describe the design of a randomized controlled trial (RCT) evaluating the effectiveness of a brief Internet-based early intervention that incorporates CBT techniques with the aim of reducing acute psychological distress and preventing long-term PTSD symptoms in injured trauma victims. Method: In a two armed RCT, 300 injured trauma victims from two Level-1 trauma centers in Amsterdam, the Netherlands, will be assigned to an intervention or a control group. Inclusion criteria are: being 18 years of age or older, having experienced a traumatic event according to the diagnostic criteria of the DSM-IV and understanding the Dutch language. The intervention group will be given access to the intervention's website (www.traumatips.nl), and are specifically requested to login within the first month postinjury. The primary clinical study outcome is PTSD symptom severity. Secondary outcomes include symptoms of depression and anxiety, quality of life, and social support. In addition, a cost-effectiveness analysis of the intervention will be performed. Data are collected at one week post-injury, prior to first login (baseline), and at 1, 3, 6 and 12 months. Analyses will be on an intention-to-treat basis. Discussion: The results will provide more insight into the effects of preventive interventions in general, and Internet-based early interventions specifically, on acute stress reactions and PTSD, in an injured population, during the acute phase after trauma. We will discuss possible strengths and limitations

Temperature Dependence of Backbone Dynamics in Human Ileal Bile Acid-Binding Protein: Implications for the Mechanism of Ligand Binding

Human ileal bile acid-binding protein (I-BABP), a member of the family of intracellular lipid binding proteins plays a key role in the cellular trafficking and metabolic regulation of bile salts. The protein has two internal and, according to a recent study, an additional superficial binding site and binds di- and trihydroxy bile salts with positive cooperativity and a high degree of site-selectivity. Previously, in the apo form, we have identified an extensive network of conformational fluctuations on the millisecond time scale, which cease upon ligation. Additionally, ligand binding at room temperature was found to be accompanied by a slight rigidification of picosecond-nanosecond (ps-ns) backbone flexibility. In the current study, temperature-dependent N-15 NMR spin relaxation measurements were used to gain more insight into the role of dynamics in human I-BABP-bile salt recognition. According to our analysis, residues sensing a conformational exchange in the apo state can be grouped into two clusters with slightly different exchange rates. The entropy-enthalpy compensation observed for both clusters suggests a disorder-order transition between a ground and a sparsely populated higher energy state in the absence of ligands. Analysis of the faster, ps-ns motion of N-15-H-1 bond vectors indicates an unusual nonlinear temperature-dependence for both ligation states. Intriguingly, while bile salt binding results in a more uniform response to temperature change throughout the protein, the temperature derivative of the generalized order parameter shows different responses to temperature increase for the two forms of the protein in the investigated temperature range. Analysis of both slow and fast motions in human I-BABP indicates largely different energy landscapes for the apo and halo states suggesting that optimization of binding interactions might be achieved by altering the dynamic behavior of specific segments in the protein

Structural basis for activation of calcineurin by calmodulin

The highly conserved phosphatase calcineurin plays vital roles in numerous processes including T-cell activation, development and function of the central nervous system, and cardiac growth. It is activated by the calcium sensor calmodulin. Calmodulin binds to a regulatory domain within calcineurin, causing a conformational change that displaces an autoinhibitory domain from the active site, resulting in activation of the phosphatase. This is the same general mechanism by which calmodulin activates calmodulin-dependent protein kinases. Previously published data has hinted that the regulatory domain of calcineurin is intrinsically disordered. In this work we demonstrate that the regulatory domain is unstructured and that it folds upon binding calmodulin, ousting the autoinhibitory domain from the catalytic site. The regulatory domain is 95 residues long, with the autoinhibitory domain attached to its C-terminal end and the 24 residue calmodulin binding region towards the N-terminal end. This is unlike the calmodulin-dependent protein kinases which have calmodulin binding sites and autoinhibitory domains immediately adjacent in sequence. Our data demonstrate that not only does the calmodulin binding region fold, but that an ~25-30 residue region between it and the autoinhibitory domain also folds, resulting in over half of the regulatory domain adopting α-helical structure. This appears to be the first observation of calmodulin inducing folding of this scale outside of its binding site on a target protein