954 resultados para Two-component systems PhoBR and PhoPQ


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BACKGROUND: In the light of sub-optimal uptake of the measles, mumps, and rubella (MMR) vaccination, we investigated the factors that influence the intentions of mothers to vaccinate. METHOD: A cross-sectional survey of 300 mothers in Birmingham with children approaching a routine MMR vaccination was conducted using a postal questionnaire to measure: intention to vaccinate, psychological variables, knowledge of the vaccine, and socioeconomic status. The vaccination status of the children was obtained from South Birmingham Child Health Surveillance Unit. RESULTS: The response rate was 59%. Fewer mothers approaching the second MMR vaccination (Group 2) intended to take their children for this vaccination than Group 1 (mothers approaching the first MMR vaccination) (Mann-Whitney U = 2180, P < 0.0001). Group 2 expressed more negative beliefs about the outcome of having the MMR vaccine ('vaccine outcome beliefs') (Mann-Whitney U = 2155, P < 0.0001), were more likely to believe it was 'unsafe' (chi 2 = 9.114, P = 0.004) and that it rarely protected (chi 2 = 6.882, P = 0.014) than Group 1. The commonest side-effect cited was general malaise, but 29.8% cited autism. The most trusted source of information was the general practitioner but the most common source of information on side-effects was television (34.6%). Multiple linear regression revealed that, in Group 1, only 'vaccine outcome beliefs' significantly predicted intention (77.1% of the variance). In Group 2 'vaccine outcome beliefs', attitude to the MMR vaccine, and prior MMR status all predicted intention (93% of the variance). CONCLUSION: A major reason for the low uptake of the MMR vaccination is that it is not perceived to be important for children's health, particularly the second dose. Health education from GPs is likely to have a considerable impact.

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Introduction: Lower back pain treatment and compensation costs >$80 billion overall in the US. 75% of back pain is due to disc degeneration in the lumbar region of the spine. Current treatment comprises of painkillers and bed rest or as a more radical solution – interbody cage fusion. In the early stages of disc degeneration the patient would benefit from addition of an injectable gel which polymerises in situ to support the degenerated nucleus pulposus. This involves a material which is an analogue of the natural tissue capable of restoring the biomechanical properties of the natural disc. The nucleus pulposus of the intervertebral disc is an example of a natural proteoglycan consisting of a protein core with negatively charged keratin and chondroitin sulphate attached. As a result of the high fixed charge density of the proteoglycan, the matrix exerts an osmotic swelling pressure drawing sufficient water into support the spinal system. Materials and Methods: NaAMPs (sodium 2- acrylamido 2-methyl propane sulphonic acid) and KSPA (potassium 3- sulphopropyl acrylate) were selected as monomers, the sulphonate group being used to mimic the natural sulphate group. These are used in dermal applications involving chronic wounds and have acceptably low cytotoxicity. Other hydrophilic carboxyl, amide and hydroxyl monomers such as 2-hydroxyethyl acrylamide, ß-carboxyethyl acrylate, acryloyl morpholine, and polyethylene glycol (meth)acrylate were used as diluents together with polyethyleneglycol di(meth)acrylate and hydrophilic multifunctional macromers as cross-linker. Redox was the chosen method of polymerisation and a range of initiators were investigated. Components were packaged in two solutions each containing a redox pair. A dual syringe method of injection into the cavity was used, the required time for polymerisation is circa 3-7 minutes. The final materials were tested using a Bohlin CVO Rheometer cycling from 0.5-25Hz at 37oC to measure the modulus. An in-house compression testing method was developed, using dialysis tubing to mimic the cavity, the gels were swelled in solutions of various osmolarity and compressed to ~ 20%. The pre-gel has also been injected into sheep spinal segments for mechanical compression testing to demonstrate the restoration of properties upon use of the gel. Results and Discussion: Two systems resulted using similar monomer compositions but different initiation and crosslinking agents. NaAMPs and KSPA were used together at a ratio of ~1:1 in both systems with 0.25-2% crosslinking agent, diacrylate or methacrylate. The two initiation systems were ascorbic acid/oxone, and N,N,N,N - tetramethylethylenediamine (TEMED)/ potassium persulphate. These systems produced gelation within 3-7 and 3-5 minutes respectively. Storage of the two component systems was shown to be stable for approximately one month after mixing, in the dark, refrigerated at 1-4oC. The gelation was carried out at 37oC. Literature values for the natural disc give elastic constants ranging from 3-8kPa. The properties of the polymer can be tailored by altering crosslink density and monomer composition and are able to match those of the natural disc. It is possible to incorporate a radio-opaque (histodenz) to enable x-ray luminescence during and after injection. At an inclusion level of 5% the gel is clearly visible and polymerisation and mechanical properties are not altered. Conclusion: A two-pac injection system which will polymerise in situ, that can incorporate a radio-opaque, has been developed. This will reinforce the damaged nucleus pulposus in degenerative disc disease restoring adequate hydration and thus biomechanical properties. Tests on sheep spine segments are currently being carried out to demonstrate that a disc containing the gel has similar properties to an intact disc in comparison to one with a damaged nucleus.

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The paper discusses facilities of computer systems for editing scientific and technical texts, which partially automate functions of human editor and thus help the writer to improve text quality. Two experimental systems LINAR and CONUT developed in 90s to control the quality of Russian scientific and technical texts are briefly described; and general principles for designing more powerful editing systems are pointed out. Features of an editing system being now under development are outlined, primarily the underlying linguistic knowledge base and procedures controlling the text.

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A novel framework for modelling biomolecular systems at multiple scales in space and time simultaneously is described. The atomistic molecular dynamics representation is smoothly connected with a statistical continuum hydrodynamics description. The system behaves correctly at the limits of pure molecular dynamics (hydrodynamics) and at the intermediate regimes when the atoms move partly as atomistic particles, and at the same time follow the hydrodynamic flows. The corresponding contributions are controlled by a parameter, which is defined as an arbitrary function of space and time, thus, allowing an effective separation of the atomistic 'core' and continuum 'environment'. To fill the scale gap between the atomistic and the continuum representations our special purpose computer for molecular dynamics, MDGRAPE-4, as well as GPU-based computing were used for developing the framework. These hardware developments also include interactive molecular dynamics simulations that allow intervention of the modelling through force-feedback devices.

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Long-lived light bullets fully localized in both space and time can be generated in novel photonic media such as multicore optical fiber or waveguide arrays. In this paper we present detailed theoretical analysis on the existence and stability of the discrete-continuous light bullets using a very generic model that occurs in a number of applications.

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The uncertainty of measurements must be quantified and considered in order to prove conformance with specifications and make other meaningful comparisons based on measurements. While there is a consistent methodology for the evaluation and expression of uncertainty within the metrology community industry frequently uses the alternative Measurement Systems Analysis methodology. This paper sets out to clarify the differences between uncertainty evaluation and MSA and presents a novel hybrid methodology for industrial measurement which enables a correct evaluation of measurement uncertainty while utilising the practical tools of MSA. In particular the use of Gage R&R ANOVA and Attribute Gage studies within a wider uncertainty evaluation framework is described. This enables in-line measurement data to be used to establish repeatability and reproducibility, without time consuming repeatability studies being carried out, while maintaining a complete consideration of all sources of uncertainty and therefore enabling conformance to be proven with a stated level of confidence. Such a rigorous approach to product verification will become increasingly important in the era of the Light Controlled Factory with metrology acting as the driving force to achieve the right first time and highly automated manufacture of high value large scale products such as aircraft, spacecraft and renewable power generation structures.

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Personalized recommender systems aim to assist users in retrieving and accessing interesting items by automatically acquiring user preferences from the historical data and matching items with the preferences. In the last decade, recommendation services have gained great attention due to the problem of information overload. However, despite recent advances of personalization techniques, several critical issues in modern recommender systems have not been well studied. These issues include: (1) understanding the accessing patterns of users (i.e., how to effectively model users' accessing behaviors); (2) understanding the relations between users and other objects (i.e., how to comprehensively assess the complex correlations between users and entities in recommender systems); and (3) understanding the interest change of users (i.e., how to adaptively capture users' preference drift over time). To meet the needs of users in modern recommender systems, it is imperative to provide solutions to address the aforementioned issues and apply the solutions to real-world applications. ^ The major goal of this dissertation is to provide integrated recommendation approaches to tackle the challenges of the current generation of recommender systems. In particular, three user-oriented aspects of recommendation techniques were studied, including understanding accessing patterns, understanding complex relations and understanding temporal dynamics. To this end, we made three research contributions. First, we presented various personalized user profiling algorithms to capture click behaviors of users from both coarse- and fine-grained granularities; second, we proposed graph-based recommendation models to describe the complex correlations in a recommender system; third, we studied temporal recommendation approaches in order to capture the preference changes of users, by considering both long-term and short-term user profiles. In addition, a versatile recommendation framework was proposed, in which the proposed recommendation techniques were seamlessly integrated. Different evaluation criteria were implemented in this framework for evaluating recommendation techniques in real-world recommendation applications. ^ In summary, the frequent changes of user interests and item repository lead to a series of user-centric challenges that are not well addressed in the current generation of recommender systems. My work proposed reasonable solutions to these challenges and provided insights on how to address these challenges using a simple yet effective recommendation framework.^

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Flavonoids are a class of over 6,500 plant metabolites that have been associated with reduced mortality from cardiovascular disease. A cross-sectional analysis of dietary flavonoids and serum cholesterol in 507 Blacks with and without type 2 diabetes (258 Haitian-Americans and 249 African-Americans) showed differences by ethnicity and diabetes status. Haitian-Americans consumed more of most flavonoids as compared to African-Americans. Individuals with type 2 diabetes consumed less of most flavonoids as compared to those without diabetes. Flavonoids were differentially associated with low-density lipoprotein cholesterol (LDL) and high-density lipoprotein cholesterol (HDL) by diabetes status. Flavanones were associated with lower LDL for participants without diabetes and higher LDL for those with diabetes, independent of ethnicity and adjusted for age, gender, cholesterol medications, daily energy, dietary fat, body mass index (BMI), and smoking. Flavan-3-ols were positively related to LDL while polyflavonoids (theaflavin and polymers, proanthocyanidins) were inversely related to LDL for the group without diabetes only. Higher anthocyanidins and flavan-3-ols and lower polyflavonoids were associated with higher HDL (same adjustments) for those without diabetes, whereas no flavonoids were associated with HDL for individuals with type 2 diabetes.

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The lead author, Nimai Senapati (Post doc), was funded by the European community’s Seventh Framework programme (FP2012-2015) under grant agreement no. 262060 (ExpeER). The research leading to these results has received funding principally from the ANR (ANR-11-INBS-0001), AllEnvi, CNRS-INSU. We would like to thank the National Research Infrastructure ‘Agro-écosystèmes, Cycles Biogéochimique et Biodiversité (SOERE-ACBB http://www.soere-acbb.com/fr/) for their support in field experiment. We are deeply indebted to Christophe deBerranger, Xavier Charrier for their substantial technical assistance and Patricia Laville for her valuables suggestion regarding N2O flux estimation.

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Acknowledgements This work was supported by University of Delhi, Department of Science and Technology- Promotion of University Research and Scientific Excellence (DST-PURSE). V.G., S.H. and U.S. gratefully acknowledge the Council for Scientific and Industrial Research (CSIR), University Grant Commission (UGC) and Department of Biotechnology (DBT) for providing research fellowship.

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Data on age, total length, total weight, gonad weight, gonadosomatic index (GSI), sex and reproductive stage for ice fish specimens collected along the sea ice gradient in McMurdo Sound, Antarctica. Species on which data are provided are; Trematomus bernacchii, Trematomus bernacchii, Pagothenia borchgrevinki and Trematomus newnesi. Location and year of collection is also included for each fish.

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Human-mediated dispersal interplays with natural processes and complicates understanding of the biogeographical history of species. This is exemplified by two invasive tunicates, Ciona robusta (formerly Ciona intestinalis type A) and C. intestinalis (formerly Ciona intestinalis type B), globally distributed and sympatric in Europe. By gathering new mitochondrial sequences that were merged with published datasets, we analysed genetic patterns in different regions, with a focus on 1) their sympatric range and 2) allopatric populations in N and S America and southern Europe. In the sympatric range, the two species display contrasting genetic diversity patterns, with low polymorphism in C. robusta supporting the prevalent view of its recent introduction. In the E Pacific, several genetic traits support the non-native status of C. robusta. However, in the NE Pacific, this appraisal requires a complex scenario of introduction and should be further examined supported by extensive sampling efforts in the NW Pacific (putative native range). For C. intestinalis, Bayesian analysis suggested a natural amphi-North Atlantic distribution, casting doubt on its non-native status in the NW Atlantic. This study shows that both natural and human-mediated dispersal have influenced genetic patterns at broad scales; this interaction lessens our ability to confidently ascertain native vs. non-native status of populations, particularly of those species that are globally distributed.

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Human-mediated dispersal interplays with natural processes and complicates understanding of the biogeographical history of species. This is exemplified by two invasive tunicates, Ciona robusta (formerly Ciona intestinalis type A) and C. intestinalis (formerly Ciona intestinalis type B), globally distributed and sympatric in Europe. By gathering new mitochondrial sequences that were merged with published datasets, we analysed genetic patterns in different regions, with a focus on 1) their sympatric range and 2) allopatric populations in N and S America and southern Europe. In the sympatric range, the two species display contrasting genetic diversity patterns, with low polymorphism in C. robusta supporting the prevalent view of its recent introduction. In the E Pacific, several genetic traits support the non-native status of C. robusta. However, in the NE Pacific, this appraisal requires a complex scenario of introduction and should be further examined supported by extensive sampling efforts in the NW Pacific (putative native range). For C. intestinalis, Bayesian analysis suggested a natural amphi-North Atlantic distribution, casting doubt on its non-native status in the NW Atlantic. This study shows that both natural and human-mediated dispersal have influenced genetic patterns at broad scales; this interaction lessens our ability to confidently ascertain native vs. non-native status of populations, particularly of those species that are globally distributed.