3,681 research outputs found
Local tunneling spectroscopy of the electron-doped cuprate Sm1.85Ce0.15CuO4
We present local tunneling spectroscopy in the optimally electron-doped
cuprate Sm2-xCexCuO4 x=0.15. A clear signature of the superconducting gap is
observed with an amplitude ranging from place to place and from sample to
sample (Delta~3.5-6meV). Another spectroscopic feature is simultaneously
observed at high energy above \pm 50meV. Its energy scale and temperature
evolution is found to be compatible with previous photoemission and optical
experiments. If interpreted as the signature of antiferromagnetic order in the
samples, these results could suggest the coexistence on the local scale of
antiferromagnetism and superconductivity on the electron-doped side of cuprate
superconductors
Nodal liquid and s-wave superconductivity in transition metal dichalcogenides
We explore the physical properties of a unified microscopic theory for the
coexistence of superconductivity and charge density waves in two-dimensional
transition metal dichalcogenides. In the case of particle-hole symmetry the
elementary particles are Dirac fermions at the nodes of the charge density wave
gap. When particle-hole symmetry is broken electron (hole) pockets are formed
around the Fermi surface. The superconducting ground state emerges from the
pairing of nodal quasi-particles mediated by acoustic phonons via a
piezoelectric coupling. We calculate several properties in the s-wave
superconducting phase, including specific heat, ultra-sound absorption, nuclear
magnetic relaxation, thermal, and optical conductivities. In the case with
particle-hole symmetry, the specific heat jump at the transition deviates
strongly from ordinary superconductors. The nuclear magnetic response shows an
anomalous anisotropy due to the broken time-reversal symmetry of the
superconducting gap, induced by the triple charge density wave state. The loss
of lattice inversion symmetry in the charge density wave phase leads to
anomalous coherence factors in the optical conductivity and to the appearance
of an absorption edge at the optical gap energy. Furthermore, optical and
thermal conductivities display anomalous peaks in the infrared when
particle-hole symmetry is broken.Comment: 23 pages, 16 figures. Published versio
Size Acceptance: A Discursive Analysis of Online Blogs
This document is an Accepted Manuscript of an article published by Taylor & Francis Group in Fat Studies on 25 May 2018, available online at: https://doi.org/10.1080/21604851.2018.1473704. Under embargo until 25 May 2019.Dominant discourses of “fatness” and “fat people” have implications for physical and mental health. Although alternative discourses such as “size acceptance” exist, there has been little consideration of the ways in which these alternative arguments (and speakers) may be positioned to be heard. Using a discursive thematic analysis, the authors demonstrate that size acceptance online bloggers have created a community online that enables them to persuasively provide alternative claims to “expertise,” which positions their views as credible and legitimate alternatives to those of more established authority figures—such as health professionals. This has implications not only for the lived experience of fat people, but also for researchers by emphasizing the importance of exploring not just what is said, but how, if we are to understand how different articulated positions are to be persuasive.Peer reviewe
Racial differences between African-American and white women in insulin resistance and visceral adiposity are associated with differences in apoCIII containing apoAI and apoB lipoproteins
Background: African-Americans have higher HDL, less visceral adipose tissue (VAT) and lower triglyceride (TG) and apoCIII concentrations than whites, despite being more insulin-resistant. We studied in African-American and white women the influences of insulin resistance and VAT on the apoAI concentrations of two HDL subspecies, one that contains apoCIII that is associated with increased risk of coronary heart disease (CHD) and one that does not have apoCIII that is associated with decreased CHD; and on the apoCIII concentrations of HDL and of the apoB lipoproteins. Methods: The participants were 32 women (14 African-Americans, 18 white) of similar age (39 ± 12 vs. 42 ± 11y). Mean BMI was 34 kg/m2 in the African-Americans compared to 30 in the whites. A standard diet (33% fat, 52% carbohydrate, 15% protein) was provided for 7 days followed by a test meal (40% fat, 40% carbohydrate, 20% protein) on Day 8. Insulin sensitivity index (SI) was calculated from the minimal model. Results: After controlling for SI, African-Americans have a higher mean apoAI level in HDL with apoCIII compared with whites (12.9 ± 2.8 and 10.9 ± 2.9 mg/dL, respectively, P = 0.05). SI was associated with higher apoAI in HDL with apoCIII, whereas VAT was not associated with this HDL subspecies. This pattern of results was reversed for apoCIII concentrations in apoB lipoproteins. After adjusting for SI, African-Americans had lower apoCIII in apoB lipoproteins. SI was associated with lower apoCIII in total apoB lipoproteins, whereas VAT was associated with higher apoCIII in all the apoB lipoproteins. Additional adjustment for VAT tended to reduce the difference in apoCIII between the groups. Conclusions: African-American women have a higher HDL with apoCIII level than whites when controlled for insulin sensitivity. African-Americans have lower insulin sensitivity. Insulin sensitivity is associated with higher levels of HDL with apoCIII. ApoCIII levels in VLDL are lower in African-American women than whites, also affected by insulin sensitivity which is associated with low apoCIII in VLDL. VAT has a strong association with apoCIII in apoB lipoproteins but not with apoAI in HDL with apoCIII. Trial registration ClinicalTrials.gov Identifier: NCT0048486
Monitoring the impacts of trade agreements on food environments
The liberalization of international trade and foreign direct investment through
multilateral, regional and bilateral agreements has had profound implications
for the structure and nature of food systems, and therefore, for the availability,
nutritional quality, accessibility, price and promotion of foods in different
locations. Public health attention has only relatively recently turned to the links
between trade and investment agreements, diets and health, and there is currently
no systematic monitoring of this area. This paper reviews the available evidence on the links between trade agreements, food environments and diets from an obesity and non-communicable disease (NCD) perspective. Based on the key issues identified through the review, the paper outlines an approach for monitoring the potential impact of trade agreements on food environments and
obesity/NCD risks. The proposed monitoring approach encompasses a set of guiding principles, recommended procedures for data collection and analysis, and quantifiable ‘minimal’, ‘expanded’ and ‘optimal’ measurement indicators to be tailored to national priorities, capacity and resources. Formal risk assessment processes of existing and evolving trade and investment agreements,
which focus on their impacts on food environments will help inform the development of healthy trade policy, strengthen domestic nutrition and health
policy space and ultimately protect population nutrition.The following organizations provided funding support for the travel of participants
to Italy for this meeting and the preparation of background research papers: The Rockefeller Foundation, International Obesity Taskforce (IOTF), University of
Auckland, Deakin University, The George Institute, University of Sydney, Queensland University of Technology, University
of Oxford, University of Pennsylvania Perelman School of Medicine, World Cancer Research Fund International, University of Toronto, and The Australian National
University. The Faculty of Health at Deakin University kindly supported the costs for open access availability of this paper,
and the Australian National Health and Medical Research Council Centre for Research Excellence in Obesity Policy and Food Systems (APP1041020) supported the coordination and finalizing of INFORMAS manuscripts
A proposed approach to monitor private-sector policies and practices related to food environments, obesity and non-communicable disease prevention
Private-sector organizations play a critical role in shaping the food environments
of individuals and populations. However, there is currently
very limited independent monitoring of private-sector actions related to
food environments. This paper reviews previous efforts to monitor the
private sector in this area, and outlines a proposed approach to monitor
private-sector policies and practices related to food environments, and
their influence on obesity and non-communicable disease (NCD) prevention.
A step-wise approach to data collection is recommended, in which
the first (‘minimal’) step is the collation of publicly available food and
nutrition-related policies of selected private-sector organizations. The
second (‘expanded’) step assesses the nutritional composition of each
organization’s products, their promotions to children, their labelling
practices, and the accessibility, availability and affordability of their
products. The third (‘optimal’) step includes data on other commercial
activities that may influence food environments, such as political lobbying
and corporate philanthropy. The proposed approach will be further
developed and piloted in countries of varying size and income levels.
There is potential for this approach to enable national and international
benchmarking of private-sector policies and practices, and to inform
efforts to hold the private sector to account for their role in obesity and
NCD prevention
Recommended from our members
IQGAP1 and IQGAP2 are Reciprocally Altered in Hepatocellular Carcinoma
<p>Abstract</p> <p>Background</p> <p>IQGAP1 and IQGAP2 are homologous members of the IQGAP family of scaffold proteins. Accumulating evidence implicates IQGAPs in tumorigenesis. We recently reported that IQGAP2 deficiency leads to the development of hepatocellular carcinoma (HCC) in mice. In the current study we extend these findings, and investigate IQGAP1 and IQGAP2 expression in human HCC.</p> <p>Methods</p> <p>IQGAP1 and IQGAP2 protein expression was assessed by Western blotting and immunohistochemistry. IQGAP mRNA was measured by quantitative RT-PCR. The methylation status of the <it>Iqgap2 </it>promoter was determined by pyrosequencing of bisulfite-treated genomic DNA.</p> <p>Results</p> <p>IQGAP1 and IQGAP2 expression was reciprocally altered in 6/6 liver cancer cell lines. Similarly, immunohistochemical staining of 82 HCC samples showed that IQGAP2 protein expression was reduced in 64/82 (78.0%), while IQGAP1 was present in 69/82 (84.1%). No IQGAP1 staining was detected in 23/28 (82.1%) normal livers, 4/4 (100.0%) hepatic adenomas and 23/23 (100.0%) cirrhosis cases, while IQGAP2 was increased in 22/28 (78.6%), 4/4 (100.0%) and 23/23 (100.0%), respectively. Although the <it>Iqgap2 </it>promoter was not hypermethylated in HCC at any of the 25 CpG sites studied (N = 17), IQGAP2 mRNA levels were significantly lower in HCC specimens (N = 23) than normal livers (N = 6).</p> <p>Conclusions</p> <p>We conclude that increased IQGAP1 and/or decreased IQGAP2 contribute to the pathogenesis of human HCC. Furthermore, downregulation of IQGAP2 in HCC occurs independently of hypermethylation of the <it>Iqgap2 </it>promoter. Immunostaining of IQGAP1 and IQGAP2 may aid in the diagnosis of HCC, and their pharmacologic modulation may represent a novel therapeutic strategy for the treatment of liver cancer.</p
Quasiparticle spectrum of the cuprate BiSrCaCuO: Possible connection to the phase diagram
We previously introduced [T. Cren et al., Europhys. Lett. 52, 203 (2000)] an
energy-dependant gap function, , that fits the unusual shape of the
quasiparticle (QP) spectrum for both BiSrCaCuO and YBaCuO. A simple
anti-resonance in accounts for the pronounced QP peaks in the
density of states, at an energy , and the dip feature at a higher
energy, . Here we go a step further : our gap function is consistent
with the () phase diagram, where is the carrier density. For large QP
energies (), the total spectral gap is , where is tied to the condensation
energy. From the available data, a simple -dependance of and
is found, in particular .
These two distinct energy scales of the superconducting state are interpreted
by comparing with the normal and pseudogap states. The various forms of the QP
density of states, as well as the spectral function , are discussed
Story in health and social care
This paper offers a brief consideration of how narrative, in the form of people‟s own stories, potentially figures in health and social care provision as part of the impulse towards patient-centred care. The rise of the epistemological legitimacy of patients‟ stories is sketched here. The paper draws upon relevant literature and original writing to consider the ways in which stories can mislead as well as illuminate the process of making individual treatment care plans
Does updating improve the methodological and reporting quality of systematic reviews?
BACKGROUND: Systematic reviews (SRs) must be of high quality. The purpose of our research was to compare the methodological and reporting quality of original versus updated Cochrane SRs to determine whether updating had improved these two quality dimensions. METHODS: We identifed updated Cochrane SRs published in issue 4, 2002 of the Cochrane Library. We assessed the updated and original versions of the SRs using two instruments: the 10 item enhanced Overview Quality Assessment Questionnaire (OQAQ), and an 18-item reporting quality checklist and flow chart based upon the Quality of Reporting of Meta-analyses (QUOROM) statement. At least two reviewers extracted data and assessed quality. We calculated the percentage (with a 95% confidence interval) of 'yes' answers to each question. We calculated mean differences in percentage, 95% confidence intervals and p-values for each of the individual items and the overall methodological quality score of the updated and pre-updated versions using OQAQ. RESULTS: We assessed 53 SRs. There was no significant improvement in the global quality score of the OQAQ (mean difference 0.11 (-0.28; 0.70 p = 0.52)). Updated reviews showed a significant improvement of 18.9 (7.2; 30.6 p < .01) on the OQAQ item assessing whether the conclusions drawn by the author(s) were supported by the data and/or analysis presented in the SR. The QUOROM statement showed that the quality of reporting of Cochrane reviews improved in some areas with updating. Improvements were seen on the items relating to data sources reported in the abstract, with a significant difference of 17.0 (9.8; 28.7 p = 0.01), review methods, reported in the abstract 35 (24.1; 49.1 p = 0.00), searching methods 18.9 (9.7; 31.6 p = 0.01), and data abstraction 18.9 (11.7; 30.9 p = 0.00). CONCLUSION: The overall quality of Cochrane SRs is fair-to-good. Although reporting quality improved on certain individual items there was no overall improvement seen with updating and methodological quality remained unchanged. Further improvement of quality of reporting is possible. There is room for improvement of methodological quality as well. Authors updating reviews should address identified methodological or reporting weaknesses. We recommend to give full attention to both quality domains when updating SRs
- …