632 research outputs found

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

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    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

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

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    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

    Polyglutamine Disruption of the Huntingtin Exon 1 N Terminus Triggers a Complex Aggregation Mechanism

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    Simple polyglutamine (polyQ) peptides aggregate in vitro via a nucleated growth pathway directly yielding amyloid-like aggregates. We show here that the 17-amino-acid flanking sequence (HTTNT) N-terminal to the polyQ in the toxic huntingtin exon 1 fragment imparts onto this peptide a complex alternative aggregation mechanism. In isolation, the HTTNT peptide is a compact coil that resists aggregation. When polyQ is fused to this sequence, it induces in HTTNT, in a repeat-length dependent fashion, a more extended conformation that greatly enhances its aggregation into globular oligomers with HTTNT cores and exposed polyQ. In a second step, a new, amyloid-like aggregate is formed with a core composed of both HTTNT and polyQ. The results indicate unprecedented complexity in how primary sequence controls aggregation within a substantially disordered peptide and have implications for the molecular mechanism of Huntington\u27s disease

    The role of citizen science in addressing grand challenges in food and agriculture research

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    The power of citizen science to contribute to both science and society is gaining increased recognition, particularly in physics and biology. Although there is a long history of public engagement in agriculture and food science, the term ‘citizen science’ has rarely been applied to these efforts. Similarly, in the emerging field of citizen science, most new citizen science projects do not focus on food or agriculture. Here, we convened thought leaders from a broad range of fields related to citizen science, agriculture, and food science to highlight key opportunities for bridging these overlapping yet disconnected communities/fields and identify ways to leverage their respective strengths. Specifically, we show that (i) citizen science projects are addressing many grand challenges facing our food systems, as outlined by the United States National Institute of Food and Agriculture, as well as broader Sustainable Development Goals set by the United Nations Development Programme, (ii) there exist emerging opportunities and unique challenges for citizen science in agriculture/food research, and (iii) the greatest opportunities for the development of citizen science projects in agriculture and food science will be gained by using the existing infrastructure and tools of Extension programmes and through the engagement of urban communities. Further, we argue there is no better time to foster greater collaboration between these fields given the trend of shrinking Extension programmes, the increasing need to apply innovative solutions to address rising demands on agricultural systems, and the exponential growth of the field of citizen science.This working group was partially funded from the NCSU Plant Sciences Initiative, College of Agriculture and Life Sciences ‘Big Ideas’ grant, National Science Foundation grant to R.R.D. (NSF no. 1319293), and a United States Department of Food and Agriculture-National Institute of Food and Agriculture grant to S.F.R., USDA-NIFA Post Doctoral Fellowships grant no. 2017-67012-26999.http://rspb.royalsocietypublishing.orghj2018Forestry and Agricultural Biotechnology Institute (FABI

    IL-9 Induces VEGF Secretion from Human Mast Cells and IL-9/IL-9 Receptor Genes Are Overexpressed in Atopic Dermatitis

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    Interleukin 9 (IL-9) has been implicated in mast cell-related inflammatory diseases, such as asthma, where vascular endothelial growth factor (VEGF) is involved. Here we report that IL-9 (10–20 ng/ml) induces gene expression and secretion of VEGF from human LAD2. IL-9 does not induce mast cell degranulation or the release of other mediators (IL-1, IL-8, or TNF). VEGF production in response to IL-9 involves STAT-3 activation. The effect is inhibited (about 80%) by the STAT-3 inhibitor, Stattic. Gene-expression of IL-9 and IL-9 receptor is significantly increased in lesional skin areas of atopic dermatitis (AD) patients as compared to normal control skin, while serum IL-9 is not different from controls. These results imply that functional interactions between IL-9 and mast cells leading to VEGF release contribute to the initiation/propagation of the pathogenesis of AD, a skin inflammatory disease

    Abo1, a conserved bromodomain AAA-ATPase, maintains global nucleosome occupancy and organisation.

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    Maintenance of the correct level and organisation of nucleosomes is crucial for genome function. Here, we uncover a role for a conserved bromodomain AAA-ATPase, Abo1, in the maintenance of nucleosome architecture in fission yeast. Cells lacking abo1(+) experience both a reduction and mis-positioning of nucleosomes at transcribed sequences in addition to increased intragenic transcription, phenotypes that are hallmarks of defective chromatin re-establishment behind RNA polymerase II. Abo1 is recruited to gene sequences and associates with histone H3 and the histone chaperone FACT. Furthermore, the distribution of Abo1 on chromatin is disturbed by impaired FACT function. The role of Abo1 extends to some promoters and also to silent heterochromatin. Abo1 is recruited to pericentromeric heterochromatin independently of the HP1 ortholog, Swi6, where it enforces proper nucleosome occupancy. Consequently, loss of Abo1 alleviates silencing and causes elevated chromosome mis-segregation. We suggest that Abo1 provides a histone chaperone function that maintains nucleosome architecture genome-wide.BBSRC (Doctoral Training Grants) Medical Research Council National Institute for Health Research (NIHR) Newcastle Biomedical Research Centre based at Newcastle Upon Tyne Hospitals NHS Foundation Trust and Newcastle University Marie Curie International Incoming FellowshipIIF275280 EMBO Long Term FellowshipALTF 1491‐2010 The Wellcome Trust095021 Wellcome Trust core funding092076 NIA fellowshipNRSA F31‐AG038153 NIH R01GM084045 Cancer CenterCCSG 2 P30 CA21765; American Lebanese Syrian Associated Charities of St. Jude Children's Research Hospital; Wellcome Trust Senior Investigator Award; Wellcome Trust Institutional Strategic Support FundWT097835MF; Newcastle UniversityWT 097823/Z/11/

    Conflict in the Indian Kashmir Valley II: psychosocial impact

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    ABSTRACT: BACKGROUND: India and Pakistan have disputed ownership of the Kashmir Valley region for many years, resulting in high level of exposure to violence among the civilian population of Kashmir (India). A survey was done as part of routine programme evaluation to assess confrontation with violence and its consequences on mental health, health service usage, and socio-economic functioning. METHODS: We undertook a two-stage cluster household survey in two districts of Kashmir (India) using questionnaires adapted from other conflict areas. Analysis was stratified for gender. RESULTS: Over one-third of respondents (n=510) were found to have symptoms of psychological distress (33.3%, CI: 28.3-38.4); women scored significantly higher (OR 2.5; CI: 1.7-3.6). A third of respondents had contemplated suicide (33.3%, CI: 28.3-38.4). Feelings of insecurity were associated with higher levels of psychological distress for both genders (males: OR 2.4, CI: 1.3-4.4; females: OR 1.9, CI: 1.1-3.3). Among males, violation of modesty, (OR 3.3, CI: 1.6-6.8), forced displacement, (OR 3.5, CI: 1.7-7.1), and physical disability resulting from violence (OR 2.7, CI: 1.2-5.9) were associated with greater levels of psychological distress; for women, risk factors for psychological distress included dependency on others for daily living (OR 2.4, CI: 1.3-4.8), the witnessing of killing (OR 1.9, CI: 1.1-3.4), and torture (OR 2.1, CI: 1.2-3.7). Self-rated poor health (male: OR 4.4, CI: 2.4-8.1; female: OR 3.4, CI: 2.0-5.8) and being unable to work (male: OR 6.7, CI: 3.5-13.0; female: OR 2.6, CI: 1.5-4.4) were associated with mental distress. CONCLUSIONS: The ongoing conflict exacts a huge toll on the communities' mental well-being. We found high levels of psychological distress that impacts on daily life and places a burden on the health system. Ongoing feelings of personal vulnerability (not feeling safe) were associated with high levels of psychological distress. Community mental health programmes should be considered as a way reduce the pressure on the health system and improve socio-economic functioning of those suffering from mental health problems

    Transdermal fentanyl for the treatment of pain caused by osteoarthritis of the knee or hip: an open, multicentre study

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    BACKGROUND: This study was designed to evaluate the utility of transdermal fentanyl (TDF, Durogesic(®)) for the treatment of pain due to osteoarthritis (OA) of the knee or hip, which was not adequately controlled by non-opioid analgesics or weak opioids. The second part of the trial, investigating TDF in patients with rheumatoid arthritis (RA) is reported separately. METHODS: Current analgesia was optimised during a 1-week run-in. Patients then received 28 days treatment with TDF starting at 25 μg/hr, with the option to increase the dose until adequate pain control was achieved. Metoclopramide was taken during the first week and then as needed. RESULTS: Of the 159 patients recruited, 75 with OA knee and 44 with OA hip completed the treatment phase, 30 knee and 18 hip patients entered the one-week taper-off phase. The most frequently used maximum dose of TDF was 25 μg/hr. The number of patients with adequate pain control increased during the run-in period from 4% to 27%, and further increased during TDF treatment to 88% on day 28. From baseline to endpoint, there were significant reductions in pain (p < 0.001) and improvements in functioning (p < 0.001) and physical (p < 0.001) and mental (p < 0.05) health. Scores for 'pain right now' decreased significantly within 24 hours of starting TDF treatment. TDF was assessed favourably and 84% of patients would recommend it for OA-related pain. Nausea and vomiting were the most common adverse events (reported by 32% and 26% of patients respectively), despite prophylaxis with metoclopramide, which showed limited efficacy in this setting. CONCLUSION: TDF significantly increased pain control, and improved functioning and quality of life. Metoclopramide appeared to be of limited value in preventing nausea and vomiting; more effective anti-emetic treatment may enable more people to benefit from strong opioids such as TDF. This study suggests that four weeks is a reasonable period to test the benefit of adding TDF to improve pain control in OA patients and that discontinuing therapy in cases of limited benefit creates no major obstacles
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