Cholesterol-Induced Buckling in Physisorbed Polymer-Tethered Lipid Monolayers

The influence of cholesterol concentration on the formation of buckling structures is studied in a physisorbed polymer-tethered lipid monolayer system using epifluorescence microscopy (EPI) and atomic force microscopy (AFM). The monolayer system, built using the Langmuir-Blodgett (LB) technique, consists of 3 mol % poly(ethylene glycol) (PEG) lipopolymers and various concentrations of the phospholipid, 1-stearoyl-2-oleoyl-sn-glycero-3-phosphocholine (SOPC), and cholesterol (CHOL). In the absence of CHOL, AFM micrographs show only occasional buckling structures, which is caused by the presence of the lipopolymers in the monolayer. In contrast, a gradual increase of CHOL concentration in the range of 0–40 mol % leads to fascinating film stress relaxation phenomena in the form of enhanced membrane buckling. Buckling structures are moderately deficient in CHOL, but do not cause any notable phospholipid-lipopolymer phase separation. Our experiments demonstrate that membrane buckling in physisorbed polymer-tethered membranes can be controlled through CHOL-mediated adjustment of membrane elastic properties. They further show that CHOL may have a notable impact on molecular confinement in the presence of crowding agents, such as lipopolymers. Our results are significant, because they offer an intriguing prospective on the role of CHOL on the material properties in complex membrane architecture

A flood damage allowance framework for coastal protection with deep uncertainty in sea-level rise

Future projections of Antarctic ice sheet (AIS) mass loss remain characterized by deep uncertainty (i.e., behavior is not well understood or widely agreed upon by experts). This complicates decisions on long-lived projects involving the height of coastal flood protection strategies that seek to reduce damages from rising sea levels. If a prescribed margin of safety does not properly account for sea-level rise and its uncertainties, the effectiveness of flood protection will decrease over time, potentially putting lives and property at greater risk. We develop a flood damage allowance framework for calculating the height of a flood protection strategy needed to ensure that a given level of financial risk is maintained (i.e., the average flood damage in a given year). The damage allowance framework considers decision-maker preferences such as planning horizons, preferred protection strategies (storm surge barrier, levee, elevation, and coastal retreat), and subjective views of AIS stability. We use Manhattan (New York City)\textemdash with the distribution of buildings, populations, and infrastructure fixed in time\textemdash as an example to show how our framework could be used to calculate a range of damage allowances based on multiple plausible AIS outcomes. Assumptions regarding future AIS stability more strongly influence damage allowances under high greenhouse gas emissions (Representative Concentration Pathway [RCP] 8.5) compared to those that assume strong emissions reductions (RCP2.6). Design tools that specify financial risk targets, such as the average flood damage in a given year, allow for the calculation of avoided flood damages (i.e., benefits) that can be combined with estimates of construction cost and then integrated into existing financial decision-making tools, like benefit-cost or cost-effectiveness analyses

Evaluating the Psychometric Quality of Social Skills Measures: A Systematic Review

Introduction - Impairments in social functioning are associated with an array of adverse outcomes. Social skills measures are commonly used by health professionals to assess and plan the treatment of social skills difficulties. There is a need to comprehensively evaluate the quality of psychometric properties reported across these measures to guide assessment and treatment planning. Objective - To conduct a systematic review of the literature on the psychometric properties of social skills and behaviours measures for both children and adults. Methods - A systematic search was performed using four electronic databases: CINAHL, PsycINFO, Embase and Pubmed; the Health and Psychosocial Instruments database; and grey literature using PsycExtra and Google Scholar. The psychometric properties of the social skills measures were evaluated against the COSMIN taxonomy of measurement properties using pre-set psychometric criteria. Results - Thirty-Six studies and nine manuals were included to assess the psychometric properties of thirteen social skills measures that met the inclusion criteria. Most measures obtained excellent overall methodological quality scores for internal consistency and reliability. However, eight measures did not report measurement error, nine measures did not report cross-cultural validity and eleven measures did not report criterion validity. Conclusions - The overall quality of the psychometric properties of most measures was satisfactory. The SSBS-2, HCSBS and PKBS-2 were the three measures with the most robust evidence of sound psychometric quality in at least seven of the eight psychometric properties that were appraised. A universal working definition of social functioning as an overarching construct is recommended. There is a need for ongoing research in the area of the psychometric properties of social skills and behaviours instruments

Agri-Food Globalisation and Rural Transformation in Chile: Smallholder Livelihoods in the Global Value Chain for Raspberries

As transnational capital continues to penetrate the agricultural sectors of developing countries, agri-food production-consumption is increasingly organised at the global scale. This has profound implications for small-scale farmers in the global South, who are being integrated into a globalising agri-food system geared towards the provision of agricultural commodities to meet the demands of wealthy consumers in Northern markets. Chile is one country that has purposefully inserted itself into the world trading system as an agri-exporter - a strategy that has fundamentally transformed Chilean agriculture. Framed within an examination of agrarian transformations in Chile and a world-historical account of agri-food globalisation, this thesis critically examines local-global linkages engendered by agri-food globalisation through a case study of export-oriented Chilean smallholder raspberry growers. The study aims to understand the structure and dynamics of the global value chain for raspberries, and to determine the livelihood implications of smallholder growers' participation in it. A detailed, locality case study was conducted in Yerbas Buenas - an important site of raspberry production within Chile - combining analysis of the raspberry value chain, and an in-depth survey of grower livelihoods. The value chain component focuses on key chain actors and functions within Chile, examining the role of public and private sector organisations governing and coordinating activities along the chain. The livelihoods component examines the significance of raspberry production within diversified household livelihood strategies, considering key assets, capabilities and mediating factors shaping smallholders' access to the value chain. Additionally, the research seeks to explore synergies and tensions between global value chain and sustainable rural livelihoods approaches, and to consider their integrative potential. The thesis finds that increasing competitive pressures, particularly arising from the evolving quality requirements of key overseas buyers, are seriously undermining the capacity of smallholder growers to participate in the chain. While existing private and public sector support is necessary for the participation of the smallest growers, it is not sufficient to secure their survival. It is argued that the neoliberal macroeconomic model represents a major barrier to smallholder participation, as the modernising agri-export-led growth strategy that it underpins can not accommodate the degree of intervention or the redistribution of resources required to address socio-economic inequality in the Chilean countryside

Semichiral fields on S^2 and generalized Kahler geometry

Abstract: We study a class of two-dimensional N=(2,2) supersymmetric gauge theories, given by semichiral multiplets coupled to the usual vector multiplet. In the UV, these theories are traditional gauge theories deformed by a gauged Wess-Zumino term. In the IR, they give rise to nonlinear sigma models on noncompact generalized K\ue4hler manifolds, which contain a three-form field H and whose metric is not K\ue4hler. We place these theories on S2 and compute their partition function exactly with localization techniques. We find that the contribution of instantons to the partition function that we define is insensitive to the deformation, and discuss our results from the point of view of the generalized K\ue4hler target space. \ua9 2016, The Author(s)

Efficacy of a Single Image-Guided Corticosteroid Injection for Glenohumeral Arthritis

Background There is limited data available on the efficacy of cortisone injection for glenohumeral osteoarthritis (GHOA). The amount and longevity of pain relief provided by a single cortisone injection is unclear. Additionally, it remains uncertain how the severity of radiographic GHOA and patient reported function and pain levels impact the efficacy of injection. Therefore, we sought to describe relief provided by a single, image guided glenohumeral injection for patients with GHOA. Additionally, we hypothesized that patients with more severe radiographic GHOA and poorer baseline shoulder function would require earlier secondary intervention. Methods Patients with symptomatic GHOA who elected to receive a corticosteroid injection for pain relief were prospectively enrolled. A phone interview was conducted to record baseline OSS and VAS scores prior to the injection, as well as at months 1, 2, 3, 4, 6, 9, and 12. Endpoints were designated when patients required a second injection, progressed to surgery, or reached month 12. Patients were grouped by their respective baseline OSS (mild, moderate/severe) and Samilson-Prieto radiographic classification (mild, moderate, severe) for analysis. Results Thirty shoulders (29 patients) were analyzed. 52% of patients were male. The average age of 66.1 years. No significant difference was seen in overall survival (defined as no additional intervention) between groups based on either OSS or Samilson-Prieto grades. Additionally, OSS and VAS scores at each follow-up were compared to baseline. For the entire cohort, a clinically significant difference was seen between baseline and months 1-4 for OSS and between baseline and months 1-4, 6,9, and 12 for VAS. Discussion This study aimed to determine the efficacy of corticosteroid injections for GHOA. There were no differences in the need for secondary interventions in this population based on severity of either the OSS or the Samilson-Prieto radiographic classification. However, patients with more severe shoulder dysfunction based on OSS did experience a statistically significant greater symptomatic relief compared with patients with milder dysfunction. Additionally, following a single injection, patients in this cohort experienced statistically and clinically relevant improvements in shoulder function and pain up to 4 months post-injection

Gauging the Poisson sigma model

We show how to carry out the gauging of the Poisson sigma model in an AKSZ inspired formulation by coupling it to the a generalization of the Weil model worked out in ref. arXiv:0706.1289 [hep-th]. We call the resulting gauged field theory, Poisson--Weil sigma model. We study the BV cohomology of the model and show its relation to Hamiltonian basic and equivariant Poisson cohomology. As an application, we carry out the gauge fixing of the pure Weil model and of the Poisson--Weil model. In the first case, we obtain the 2--dimensional version of Donaldson--Witten topological gauge theory, describing the moduli space of flat connections on a closed surface. In the second case, we recover the gauged A topological sigma model worked out by Baptista describing the moduli space of solutions of the so--called vortex equations.Comment: 49 pages, no figures. Typos corrected. Presentation improve

Individuals with Le(a+b−) Blood Group Have Increased Susceptibility to Symptomatic Vibrio cholerae O1 Infection

Cholera remains a severe diarrheal disease, capable of causing extensive outbreaks and high mortality. Blood group is one of the genetic factors determining predisposition to disease, including infectious diseases. Expression of different Lewis or ABO blood group types has been shown to be associated with risk of different enteric infections. For example, individuals of blood group O have a higher risk of severe illness due to V. cholerae compared to those with non-blood group O antigens. In this study, we have determined the relationship of the Lewis blood group antigen phenotypes with the risk of symptomatic cholera as well as the severity of disease and immune responses following infection. We show that individuals expressing the Le(a+b−) phenotype were more susceptible to symptomatic cholera, while Le(a–b+) expressing individuals were less susceptible. Individuals with the Le(a–b−) blood group had a longer duration of diarrhea when infected, required more intravenous fluid replacement, and had lower plasma IgA antibody responses to V. cholerae LPS on day 7 following infection. We conclude that there is an association between the Lewis blood group and the risk of cholera, and that this risk may affect the outcome of infection as well as possibly the efficacy of vaccination