295 research outputs found

    Multiorder coherent Raman scattering of a quantum probe field

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    We study the multiorder coherent Raman scattering of a quantum probe field in a far-off-resonance medium with a prepared coherence. Under the conditions of negligible dispersion and limited bandwidth, we derive a Bessel-function solution for the sideband field operators. We analytically and numerically calculate various quantum statistical characteristics of the sideband fields. We show that the multiorder coherent Raman process can replicate the statistical properties of a single-mode quantum probe field into a broad comb of generated Raman sidebands. We also study the mixing and modulation of photon statistical properties in the case of two-mode input. We show that the prepared Raman coherence and the medium length can be used as control parameters to switch a sideband field from one type of photon statistics to another type, or from a non-squeezed state to a squeezed state and vice versa.Comment: 12 pages, 7 figures, to be published in Phys. Rev.

    The Current State of Climate Change Perceptions and Policies in Vietnam: 2014 Report

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    This report was constructed to assess the current perceptions and policies regarding climate change in Vietnam. The report comprises a country report, outlining current policies relating to climate change, stakeholder mapping regarding climate change locally and nationally, and results from two stakeholder perception surveys conducted locally and nationally in Vietnam. A total of 50 stakeholders were interviewed, 25 locally and 25 nationally. The stakeholders in the survey represented government offices, universities, research institutions, NGOs, and farmers’ groups. Concerns about climate change impacts included drought, flooding, rainfall variation, and salinity intrusion. These concerns, as well as the methods in which stakeholders would like to receive climate information, varied between local and national stakeholders as well as by the type of institution that the stakeholder represented. This emphasizes a need for location- and user-specific responses to climate change

    Enhanced insulin sensitivity associated with provision of mono and polyunsaturated fatty acids in skeletal muscle cells involves counter modulation of PP2A

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    International audienceAims/Hypothesis: Reduced skeletal muscle insulin sensitivity is a feature associated with sustained exposure to excess saturated fatty acids (SFA), whereas mono and polyunsaturated fatty acids (MUFA and PUFA) not only improve insulin sensitivity but blunt SFA-induced insulin resistance. The mechanisms by which MUFAs and PUFAs institute these favourable changes remain unclear, but may involve stimulating insulin signalling by counter-modulation/repression of protein phosphatase 2A (PP2A). This study investigated the effects of oleic acid (OA; a MUFA), linoleic acid (LOA; a PUFA) and palmitate (PA; a SFA) in cultured myotubes and determined whether changes in insulin signalling can be attributed to PP2A regulation. Principal Findings: We treated cultured skeletal myotubes with unsaturated and saturated fatty acids and evaluated insulin signalling, phosphorylation and methylation status of the catalytic subunit of PP2A. Unlike PA, sustained incubation of rat or human myotubes with OA or LOA significantly enhanced Akt-and ERK1/2-directed insulin signalling. This was not due to heightened upstream IRS1 or PI3K signalling nor to changes in expression of proteins involved in proximal insulin signalling, but was associated with reduced dephosphorylation/inactivation of Akt and ERK1/2. Consistent with this, PA reduced PP2Ac demethylation and tyrosine 307 phosphorylation-events associated with PP2A activation. In contrast, OA and LOA strongly opposed these PA-induced changes in PP2Ac thus exerting a repressive effect on PP2A.Conclusions/Interpretation: Beneficial gains in insulin sensitivity and the ability of unsaturated fatty acids to oppose palmitate-induced insulin resistance in muscle cells may partly be accounted for by counter-modulation of PP2A

    Gender Differences in Climate Change Perception and Adaptation Strategies: The Case of Three Provinces in Vietnam’s Mekong River Delta

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    The Policy Information and Response Platform on Climate Change and Rice in ASEAN and its Member Countries Project (PIRCCA) is one of the trial projects funded under Flagship 4. PIRCCA has an overarching goal to enable policymakers in ASEAN countries to make informed decisions on (1) food security policies focusing on the supply and availability of rice, (2) climate change adaptation policies, and (3) gender action plans

    Necessary Conditions for Multiobjective Optimal Control Problems with Free End-Time

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    Differential maturation and subcellular localization of severe acute respiratory syndrome coronavirus surface proteins S, M and E

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    Post-translational modifications and correct subcellular localization of viral structural proteins are prerequisites for assembly and budding of enveloped viruses. Coronaviruses, like the severe acute respiratory syndrome-associated virus (SARS-CoV), bud from the endoplasmic reticulum-Golgi intermediate compartment. In this study, the subcellular distribution and maturation of SARS-CoV surface proteins S, M and E were analysed by using C-terminally tagged proteins. As early as 30 min post-entry into the endoplasmic reticulum, high-mannosylated S assembles into trimers prior to acquisition of complex N-glycans in the Golgi. Like S, M acquires high-mannose N-glycans that are subsequently modified into complex N-glycans in the Golgi. The N-glycosylation profile and the absence of O-glycosylation on M protein relate SARS-CoV to the previously described group 1 and 3 coronaviruses. Immunofluorescence analysis shows that S is detected in several compartments along the secretory pathway from the endoplasmic reticulum to the plasma membrane while M predominantly localizes in the Golgi, where it accumulates, and in trafficking vesicles. The E protein is not glycosylated. Pulse-chase labelling and confocal microscopy in the presence of protein translation inhibitor cycloheximide revealed that the E protein has a short half-life of 30 min. E protein is found in bright perinuclear patches colocalizing with endoplasmic reticulum markers. In conclusion, SARS-CoV surface proteins S, M and E show differential subcellular localizations when expressed alone suggesting that additional cellular or viral factors might be required for coordinated trafficking to the virus assembly site in the endoplasmic reticulum-Golgi intermediate compartment. © 2005 SGM.postprin

    Ezrin interacts with the SARS coronavirus spike protein and restrains infection at the entry stage

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    © 2012 Millet et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Background: Entry of Severe Acute Respiratory Syndrome coronavirus (SARS-CoV) and its envelope fusion with host cell membrane are controlled by a series of complex molecular mechanisms, largely dependent on the viral envelope glycoprotein Spike (S). There are still many unknowns on the implication of cellular factors that regulate the entry process. Methodology/Principal Findings: We performed a yeast two-hybrid screen using as bait the carboxy-terminal endodomain of S, which faces the cytosol during and after opening of the fusion pore at early stages of the virus life cycle. Here we show that the ezrin membrane-actin linker interacts with S endodomain through the F1 lobe of its FERM domain and that both the eight carboxy-terminal amino-acids and a membrane-proximal cysteine cluster of S endodomain are important for this interaction in vitro. Interestingly, we found that ezrin is present at the site of entry of S-pseudotyped lentiviral particles in Vero E6 cells. Targeting ezrin function by small interfering RNA increased S-mediated entry of pseudotyped particles in epithelial cells. Furthermore, deletion of the eight carboxy-terminal amino acids of S enhanced S-pseudotyped particles infection. Expression of the ezrin dominant negative FERM domain enhanced cell susceptibility to infection by SARS-CoV and S pseudotyped particles and potentiated S-dependent membrane fusion. Conclusions/Significance: Ezrin interacts with SARS-CoV S endodomain and limits virus entry and fusion. Our data present a novel mechanism involving a cellular factor in the regulation of S-dependent early events of infection.This work was supported by the Research Grant Council of Hong Kong (RGC#760208)and the RESPARI project of the International Network of Pasteur Institutes

    S.11.1 Influence of digital ulcer healing on disability and daily activity limitations in SSc

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    Objective. We previously showed that DU significantly increased global and hand disability with a significant impact on activities of daily living (ADLs) and work disability. This study aims to evaluate the impact of digital ulcer (DU) healing on disability and daily activity limitations in SSc. Methods. From January 2008 and June 2009, we prospectively evaluated 189 SSc patients for DU history, disability, employment and occupational status during meetings of the French SSc Patient Association (n = 86, 45.5%) or during hospitalization (n = 103, 54.5%)1. Among the 60 patients with at least one active DU at baseline (M0), 40 patients were followed longitudinally over 6 (3) months. These patients were evaluated for DU history, global and hand disability, health-related quality of life (HRQoL), daily activity limitation and employment status. Results. The median (IQR) age was 57.5 (43.5-68) years and the median (IQR) disease duration was 8.3 (3-16.5) years. Twenty-two (55%) patients had diffuse SSc and 34 (85%) were females. At baseline, a mean of 2.9 (2.8) DU per patient was reported. Thirty-three (82.5%) patients had ischaemic DU, 7 (17.5%) patients had >1 DU associated with calcinosis and 13 (32.5%) patients had mechanical DU. Thirteen (32.5%) patients had >4 DU at baseline. Among the 40 patients, 16 (40%) patients showed complete ulcer healing. In these patients with DU, the presence of calcinosis was associated with a lower probability of healing (P = 0.03). Comparison between healed and no-healed DU patients showed an improvement of hand disability provided by an improvement of the Cochin Hand Function score (P = 0.05)) and a trend towards HAQ domain dressing and grooming (P = 0.06) between M0 and M6 (3) visit in healed patients but not in no-healed patients. Concerning HRQoL, there were no difference for Mental and Physical component Scores of SF-36 but significant improvement of Bodily Pain score (P = 0.04) and Physical Role score (P = 0.05) between M0 and M6 (3) visit in patients with healed DU. The absence of healing was associated with significantly decreased work productivity (P = 0.05), whereas the performance in ADL was not significantly decreased (P = 0.15). Patients who were on sick-leave and who received some help for household tasks at the time of active DU were more likely to heal. Conclusion. For the first time, we provide prospective data with evidence that DU healing is associated with an improvement in hand function. Sick leave was associated with better healing of D

    Combination of inflammatory and vascular markers in the febrile phase of dengue is associated with more severe outcomes

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    Background: Early identification of severe dengue patients is important regarding patient management and resource allocation. We investigated the association of 10 biomarkers (VCAM-1, SDC-1, Ang-2, IL-8, IP-10, IL-1RA, sCD163, sTREM-1, ferritin, CRP) with the development of severe/moderate dengue (S/MD). Methods: We performed a nested case-control study from a multi-country study. A total of 281 S/MD and 556 uncomplicated dengue cases were included. Results: On days 1–3 from symptom onset, higher levels of any biomarker increased the risk of developing S/MD. When assessing together, SDC-1 and IL-1RA were stable, while IP-10 changed the association from positive to negative; others showed weaker associations. The best combinations associated with S/MD comprised IL-1RA, Ang-2, IL-8, ferritin, IP-10, and SDC-1 for children, and SDC-1, IL-8, ferritin, sTREM-1, IL-1RA, IP-10, and sCD163 for adults. Conclusions: Our findings assist the development of biomarker panels for clinical use and could improve triage and risk prediction in dengue patients. Funding: This study was supported by the EU's Seventh Framework Programme (FP7-281803 IDAMS), the WHO, and the Bill and Melinda Gates Foundation
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