48 research outputs found

    Imaging zero-offset 3D P-cable data with CRS method

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    Standard seismic acquisition and processing require appropriate source-receiver offsets. P-cable technology represents the opposite, namely, very short source-receiver offsets at the price of increased spatial and lateral resolution with a high-frequency source. To use this advantage, a processing flow excluding offset information is required. This aim can be achieved with a processing tuned to diffractions because point diffractions scatter the same information in offset and midpoint direction. Usually, diffractions are small amplitude events and a careful diffraction separation is required as a first step. We suggest the strategy to use a multiparameter stacking operator, e.g, common-reflection surface, and stack along the midpoint direction. The obtained kinematic wavefront attributes are used to calculate time-migration velocities. A diffractivity map serves as filter to refine the velocities. This strategy is applied to a 3D P-cable data set to obtain a time-migrated image

    Prevalence of vaccine-derived polioviruses in sewage and river water in South Africa

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    Polioviruses (PVs) are not associated with waterborne transmission to the same extent as many other enteric viruses. However, they are typically transmitted by the faecal-oral route, which implies that the risk of infection by exposure to the viruses in water cannot be underestimated. The risk appears particularly high for rural communities, which use sewage-polluted river water for domestic purposes. Thus, the presence in the environment of highly evolved, neurovirulent vaccine-derived poliovirus (VDPV) strains in the absence of polio cases would have important implications for strategies to terminate immunisation with oral poliovirus vaccine (OPV) following global polio eradication. The aim of the current study was to determine the prevalence of VDPVs in selected sewage and river water samples collected from 2001 to 2003, and to construct phylogenetic trees of the partially sequenced 5′untranslated region (5′UTR) and the VP1 region of the genomes to deduce the genetic relatedness between the PV strains. Using the monolayer plaque assay, 703 plaques from sewage and 157 plaques from river water samples were analysed. Application of a RT-multiplex PCR revealed that 176 of these plaques were non-polio enteroviruses, and 49 were PV isolates. The Sabin-specific RT-triplex PCR revealed the presence of 29 Sabin PV type 1, 8 Sabin PV type 2 and 12 Sabin PV type 3 isolates. The 5′UTR and the VP1 region of 13 PV type 1, 7 PV type 3 and 6 PV type 2 isolates were partially sequenced. The majority of the OPV isolates (24 out of 26) displayed close sequence relationships (>99% VP1 sequence identity) to the parental Sabin PV vaccine strains and were classified as “OPV-like viruses”. Two isolates (D1 08/28 and OF1 05/21) were found to be highly divergent and were classified as “suspected” VDPVs. Isolate OF1 05/21 (a “suspected” VDPV type 1) showed more than 0.9% divergence in VP1, whereas isolate D1 08/28 (a “suspected” VDPV type 2) showed 1.4% divergence in VP1 from the parental Sabin PV vaccine strains. As with most of the other OPV-like isolates, these “suspected” VDPVs were carrying mutations, which have previously been associated with reversion of the attenuated Sabin PV strains to increased neurovirulence. It was estimated that the total period of replication for the two “suspected” VDPVs was between 12 and 16 months. In conclusion, this study provided new and relevant information on the prevalence of “suspected” VDPVs in sewage andMedical Virolog

    Quercetin prevents progression of disease in elastase/LPS-exposed mice by negatively regulating MMP expression

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    Abstract Background Chronic obstructive pulmonary disease (COPD) is characterized by chronic bronchitis, emphysema and irreversible airflow limitation. These changes are thought to be due to oxidative stress and an imbalance of proteases and antiproteases. Quercetin, a plant flavonoid, is a potent antioxidant and anti-inflammatory agent. We hypothesized that quercetin reduces lung inflammation and improves lung function in elastase/lipopolysaccharide (LPS)-exposed mice which show typical features of COPD, including airways inflammation, goblet cell metaplasia, and emphysema. Methods Mice treated with elastase and LPS once a week for 4 weeks were subsequently administered 0.5 mg of quercetin dihydrate or 50% propylene glycol (vehicle) by gavage for 10 days. Lungs were examined for elastance, oxidative stress, inflammation, and matrix metalloproteinase (MMP) activity. Effects of quercetin on MMP transcription and activity were examined in LPS-exposed murine macrophages. Results Quercetin-treated, elastase/LPS-exposed mice showed improved elastic recoil and decreased alveolar chord length compared to vehicle-treated controls. Quercetin-treated mice showed decreased levels of thiobarbituric acid reactive substances, a measure of lipid peroxidation caused by oxidative stress. Quercetin also reduced lung inflammation, goblet cell metaplasia, and mRNA expression of pro-inflammatory cytokines and muc5AC. Quercetin treatment decreased the expression and activity of MMP9 and MMP12 in vivo and in vitro, while increasing expression of the histone deacetylase Sirt-1 and suppressing MMP promoter H4 acetylation. Finally, co-treatment with the Sirt-1 inhibitor sirtinol blocked the effects of quercetin on the lung phenotype. Conclusions Quercetin prevents progression of emphysema in elastase/LPS-treated mice by reducing oxidative stress, lung inflammation and expression of MMP9 and MMP12.http://deepblue.lib.umich.edu/bitstream/2027.42/78260/1/1465-9921-11-131.xmlhttp://deepblue.lib.umich.edu/bitstream/2027.42/78260/2/1465-9921-11-131.pdfPeer Reviewe

    A systematic review of the role of vitamin insufficiencies and supplementation in COPD

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    <p>Abstract</p> <p>Background</p> <p>Pulmonary inflammation, oxidants-antioxidants imbalance, as well as innate and adaptive immunity have been proposed as playing a key role in the development of COPD. The role of vitamins, as assessed either by food frequency questionnaires or measured in serum levels, have been reported to improve pulmonary function, reduce exacerbations and improve symptoms. Vitamin supplements have therefore been proposed to be a potentially useful additive to COPD therapy.</p> <p>Methods</p> <p>A systematic literature review was performed on the association of vitamins and COPD. The role of vitamin supplements in COPD was then evaluated.</p> <p>Conclusions</p> <p>The results of this review showed that various vitamins (vitamin C, D, E, A, beta and alpha carotene) are associated with improvement in features of COPD such as symptoms, exacerbations and pulmonary function. High vitamin intake would probably reduce the annual decline of FEV1. There were no studies that showed benefit from vitamin supplementation in improved symptoms, decreased hospitalization or pulmonary function.</p

    Behavioural Risk Factors in Mid-Life Associated with Successful Ageing, Disability, Dementia and Frailty in Later Life: A Rapid Systematic Review.

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    BACKGROUND: Smoking, alcohol consumption, poor diet and low levels of physical activity significantly contribute to the burden of illness in developed countries. Whilst the links between specific and multiple risk behaviours and individual chronic conditions are well documented, the impact of these behaviours in mid-life across a range of later life outcomes has yet to be comprehensively assessed. This review aimed to provide an overview of behavioural risk factors in mid-life that are associated with successful ageing and the primary prevention or delay of disability, dementia, frailty and non-communicable chronic conditions. METHODS: A literature search was conducted to identify cohort studies published in English since 2000 up to Dec 2014. Multivariate analyses and a minimum follow-up of five years were required for inclusion. Two reviewers screened titles, abstracts and papers independently. Studies were assessed for quality. Evidence was synthesised by mid-life behavioural risk for a range of late life outcomes. FINDINGS: This search located 10,338 individual references, of which 164 are included in this review. Follow-up data ranged from five years to 36 years. Outcomes include dementia, frailty, disability and cardiovascular disease. There is consistent evidence of beneficial associations between mid-life physical activity, healthy ageing and disease outcomes. Across all populations studied there is consistent evidence that mid-life smoking has a detrimental effect on health. Evidence specific to alcohol consumption was mixed. Limited, but supportive, evidence was available relating specifically to mid-life diet, leisure and social activities or health inequalities. CONCLUSIONS: There is consistent evidence of associations between mid-life behaviours and a range of late life outcomes. The promotion of physical activity, healthy diet and smoking cessation in all mid-life populations should be encouraged for successful ageing and the prevention of disability and chronic disease.This work was funded by the National Institute for Health and Care Excellence (NICE), invitation to tender reference DDER 42013, and supported by the National Institute for Health Research School for Public Health Research. The scope of the work was defined by NICE and the protocol was agreed with NICE prior to the start of work. The funders had no role in data analysis, preparation of the manuscript or decision to publish.This is the final version of the article. It first appeared from PLOS via http://dx.doi.org/10.1371/journal.pone.014440

    Fruit and vegetable intake and the risk of cardiovascular disease, total cancer and all-cause mortality – a systematic review and dose-response meta-analysis of prospective studies

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    Background: Questions remain about the strength and shape of the dose-response relationship between fruit and vegetable intake and risk of cardiovascular disease, cancer and mortality, and the effects of specific types of fruit and vegetables. We conducted a systematic review and meta-analysis to clarify these associations. Methods: PubMed and Embase were searched up to 29 September 2016. Prospective studies of fruit and vegetable intake and cardiovascular disease, total cancer and all-cause mortality were included. Summary relative risks (RRs) were calculated using a random effects model, and the mortality burden globally was estimated; 95 studies (142 publications) were included. Results: For fruits and vegetables combined, the summary RR per 200 g/day was 0.92 [95% confidence interval (CI): 0.90–0.94, I2 = 0%, n = 15] for coronary heart disease, 0.84 (95% CI: 0.76–0.92, I2 = 73%, n = 10) for stroke, 0.92 (95% CI: 0.90–0.95, I2 = 31%, n = 13) for cardiovascular disease, 0.97 (95% CI: 0.95–0.99, I2 = 49%, n = 12) for total cancer and 0.90 (95% CI: 0.87–0.93, I2 = 83%, n = 15) for all-cause mortality. Similar associations were observed for fruits and vegetables separately. Reductions in risk were observed up to 800 g/day for all outcomes except cancer (600 g/day). Inverse associations were observed between the intake of apples and pears, citrus fruits, green leafy vegetables, cruciferous vegetables, and salads and cardiovascular disease and all-cause mortality, and between the intake of green-yellow vegetables and cruciferous vegetables and total cancer risk. An estimated 5.6 and 7.8 million premature deaths worldwide in 2013 may be attributable to a fruit and vegetable intake below 500 and 800 g/day, respectively, if the observed associations are causal. Conclusions: Fruit and vegetable intakes were associated with reduced risk of cardiovascular disease, cancer and all-cause mortality. These results support public health recommendations to increase fruit and vegetable intake for the prevention of cardiovascular disease, cancer, and premature mortality

    General framework: urban farming and ruralisation

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    A competitive comparison of multiparameter stacking operators

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    The classic common-midpoint (CMP) stack, which sums along offsets, suffers in challenging environments in which the acquisition is sparse. In the past, several multiparameter stacking techniques were introduced that incorporate many neighboring CMPs during summation. This increases data redundancy and reduces noise. Multiparameter methods that can be parameterized by the same wavefront attributes are multifocusing (MF), the common-reflection-surface (CRS), implicit CRS, and nonhyperbolic CRS (nCRS). The CRS-type operators use a velocity-shift mechanism to account for heterogeneity by changing the slope of the asymptote. On the other hand, MF uses a different mechanism: a shift of reference time while preserving the slope of the asymptote. We have formulated MF such that it uses the same mechanism as the CRS-type operators and compare them on a marine data set. In turn, we investigate the behavior of time-shifted versions of the CRS-type approximations. To provide a fair comparison, we use a global optimization technique, differential evolution, which allows to accurately estimate a solution without an initial guess solution. Our results indicate that the velocity-shift mechanism performs, in general, better than the one incorporating a time shift. The double-square-root operators are also less sensitive to the choice of aperture. They perform better in the case of diffractions than conventional hyperbolic CRS, and this fact is in good agreement with previous works. In our work the nCRS is of almost the same computational cost as that of conventional hyperbolic CRS, but it generally leads to a superior fit; therefore, we recommend its use in the future

    A competitive comparison of multiparameter stacking operators

    No full text
    The classic common-midpoint (CMP) stack, which sums along offsets, suffers in challenging environments in which the acquisition is sparse. In the past, several multiparameter stacking techniques were introduced that incorporate many neighboring CMPs during summation. This increases data redundancy and reduces noise. Multiparameter methods that can be parameterized by the same wavefront attributes are multifocusing (MF), the common-reflection-surface (CRS), implicit CRS, and nonhyperbolic CRS (nCRS). The CRS-type operators use a velocity-shift mechanism to account for heterogeneity by changing the slope of the asymptote. On the other hand, MF uses a different mechanism: a shift of reference time while preserving the slope of the asymptote. We have formulated MF such that it uses the same mechanism as the CRS-type operators and compare them on a marine data set. In turn, we investigate the behavior of time-shifted versions of the CRS-type approximations. To provide a fair comparison, we use a global optimization technique, differential evolution, which allows to accurately estimate a solution without an initial guess solution. Our results indicate that the velocity-shift mechanism performs, in general, better than the one incorporating a time shift. The double-square-root operators are also less sensitive to the choice of aperture. They perform better in the case of diffractions than conventional hyperbolic CRS, and this fact is in good agreement with previous works. In our work the nCRS is of almost the same computational cost as that of conventional hyperbolic CRS, but it generally leads to a superior fit; therefore, we recommend its use in the future

    Civil-Military Assessment Mission for Libyan Heritage by Blue Shield and IMCuRWG, September 28 to 30, 2011: mission report

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    Report of the 1st cultural emergency mission to Libya September 2011 by Blue Shield and IMCURWG
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