972 resultados para Essential services
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The essential oil in purple magnolia leaves was extracted by steam distillation approaches. The oil obtained was dried with anhydrous magnesium sulfate. According to the analysis of gas chromatography/mass spectrometry, more than 40 peaks were separated and 32 compounds were identified. The identified constituents represent 95% of the peak area of the essential oil. The main compounds were germacrene-D, santolina triene, caryophyllene, 1,3,7-octatriene, 3,7-dimethyl, and camphene, etc.
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本论文主要研究两种重要的调节蜕皮过程的基因—蜕皮激素效应基因E75和RXR在中国明对虾蜕皮中的作用。利用RT-PCR和RACE技术获得了编码FcE75和FcRXR的全长cDNA序列。FcRXR包含7个内含子,在对虾中存在不同的异形体,命名为RXR-1和RXR-2。应用荧光实时定量PCR分析表明FcE75和FcRXR基因在中国明对虾蜕皮前期(D3)其转录表达量明显上调。另外,FcE75和FcRXR基因在不同组织中的转录表达存在明显的差异。利用FcE75和FcRXR基因的双链RNA注射对虾能有效降低FcE75和FcRXR的表达水平。FcE75和FcRXR的体内沉默完全抑制了对虾的蜕皮过程,并且引起对虾的死亡。对不能正常蜕皮个体进行观察的结果表明,FcE75沉默的对虾,其上皮的收缩、新的刚毛及新表皮的形成均收到限制。在FcE75双链RNA沉默后的对虾中,我们检测了与蜕皮相关的一些效应因子,如chitinase等的转录,发现这些效应因子的转录明显受到抑制,说明FcE75和FcRXR在蜕皮过程中起到非常重要的作用。本论文首次阐明了这些基因在十足目甲壳动物蜕皮过程中的功能。
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The composition of the leaf oils from seven populations of J. sabina L., one population of Juniperus sabina var. arenaria (E. H. Wilson) Farjon were examined for their geographic variation. In addition, the leaf oils of J. chinensis L. and J. davurica Pall. were compared to J. sabina. Juniperus sabina var. arenarla, the sand loving juniper, oil was found to be very similar to that of J. davurica, Mongolia, and J. sabina, on sand dunes in Mongolia. This suggests that J. sabina var. arenaria might be conspecific with J. davurica. Farjon's move (2001) of J. sabina var. arenaria out of J. chinensis is supported. Considerable differentiation was found in populations of J. sabina from the Iberian peninsula. Cedrol, citronellol, safrole, trans-sabinyl acetate, terpinen-4-ol and beta-thujone were found to be polymorphic in several populations.
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The effects of hypoxia on the levels of essential macroelements and trace elements (K, Na, Ca, Mg, Cu, Zn, Fe, and Mn) in the heart muscles of Wistar rats and plateau pikas (Ochotona curzoniae) were studied by atomic absorption spectrometry. Unlike the rat, the plateau pika is tolerant to hypoxia. The levels of K, Na, and the trace element Mn were not significantly changed in rat or pika hearts after exposure to hypoxia for 1, 10, or 25 d at simulated altitudes of 5000 and 7000 m. Other minerals (Ca, Mg, Cu, Zn, and Fe) were significantly affected by hypoxia and the levels followed different time-courses under different hypoxic regimes in these two animals. There were marked differences between the rat and pika in myocardial accumulation of essential elements such as Ca, which was increased to high levels in the rat but not affected in the pika. The results suggest that hypoxia affects animal physiological mechanisms by regulating the levels of essential elements.
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随着网络技术、特别是Internet技术的发展,分布式系统的高睦能、高可靠性、高灵敏度、可扩展性和系统透明性使得基于分布式系统的应用越来越广泛。在分布式坏境下,信息系统的集成是必须认真考虑的问题。研究如何集成和统一访问分布的、异构的数据资源,实现各种数据的转换、交流与共享;以及如何建立一个开放、可扩展和异构兼容的新一代信息管理系统成为当今网络应用的重要研究方向。本文针对建立月球探测数据管理和集成系统的数据集成与操作集成两方面的内容,重点分析和研究了数据存储管理和系统集成技术,结合月球探测数据管理的应用集成需求与特点提出了基于XML技术的数据存储与管理和基于Web Service技术的系统集成方案。并利用XML/WebService技术基于Net平台开发了一个月球探测数据管理与集成系统实例。研究内容主要包括以下四个方面: (1)基于XML的数据模型与数据库存储。利用XML的自描述性、独立于平台和应用、半结构化,机器可处理、可扩展性以及便于网络传输和广泛支持的特性,实现了基于关系数据库的XML数据存储。对系统中的结构化和非结构化数据信息、都进行了XML标记定义,实现了信息存储和查询的小粒度,增强了数据的表示、查询、插入和删除等数据处理能力和效率。同时,利用XML作为月球探测数据交换和信息传输的格式,也为实现与异构系统数据的互操作提供了理想的角军决方案。(2)基于WebServices的分布式信息系统集成的体系结构。在对XML、SOAP、WSDL和UDDI关键技术和标准规范进行研究与探讨基础上,针对绕月探测数据管理的需求提出了基于XML/Web Service的三层分布式结构模型。分别是表示层、应用逻辑层、服务端数据层。实现了系统功能的可迁移性和可装配性、各层间传输过程中数据流的XML化、接口定义的动态性。与传统技术开发的耦合的分布式应用系统相比,系统在跨平台性、可配置性、可伸缩性、可维护性等方面都有了大幅度的提高。(3)基于,NET平台系统的开发与实现。深入分析和研究了Mic1’osoft.NET平台的核心技术与整体技术框架,在VisLla1Sttldio.NET开发环境中利用C#、ASP.NET、ADO.NET基于关系型数据库Oracle9i开发实现了统一身份认证系统和月球探测数据管理与集成系统。统一身份认证系统是一个通用的统一用户身份认证管理系统,包括用户管理、身份验证、实体管理、日志监控和消息、管理等功能,达到了一次登录,所有系统共用的目的。月球探测数据管理与集成系统包括数据管理、信息发布、系统管理、综合查询和应用集成五大功能模块,相对于原来的紧祸合的应用系统而言,系统的开发效率、重用性、祸合度、灵活性和自适 应性都有了很大的提高。(4)基于XML/WebServices的动态系统集成。分析了传统分布式对象模型在异构环境集成的弊端,基于XML、SOAP和WSDL等技术规范基础上,实现了统一身份认证系统、月球探测数据管理与集成系统、小空间碎片数据库系统以及其它语言开发的应用系统的信息集成、实现了资源时空的有效整合。通过这些集成应用实例,充分体现和说明了Web Services技术在应用系统集成方面的优越性。本研究的成果,也将为地球化学研究领域涉及海量数据的处理、管理和系统集成提供示范实例,推动地球化学数据的融合和综合应用。
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This paper presents a novel algorithm for learning in a class of stochastic Markov decision processes (MDPs) with continuous state and action spaces that trades speed for accuracy. A transform of the stochastic MDP into a deterministic one is presented which captures the essence of the original dynamics, in a sense made precise. In this transformed MDP, the calculation of values is greatly simplified. The online algorithm estimates the model of the transformed MDP and simultaneously does policy search against it. Bounds on the error of this approximation are proven, and experimental results in a bicycle riding domain are presented. The algorithm learns near optimal policies in orders of magnitude fewer interactions with the stochastic MDP, using less domain knowledge. All code used in the experiments is available on the project's web site.
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A sample of tobacco essential oil was analyzed using gas chromatography-mass spectrometry (GUMS)and comprehensive two-dimensional gas chromatography coupled to a time-of-flight mass spectrometry (GC x GC/TOFMS), respectively. In the GUMS analysis, serially coupled columns were used. By comparing the GUMS results with GC x GC/TOFMS result,,, many more components in the essential oil could be found within the two-dimensional separation space of GC x GC. The quantitative determination of components in the essential oil was performed by GC x GC with flame ionization detection (FID), using a method of multiple internal standards calibration, (c) 2005 Elsevier B.V. All rights reserved.
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A quantitative analysis of the individual compounds in tobacco essential oils is performed by comprehensive two-dimensional gas chromatography (GC x GC) combined with flame ionization detector (FID). A time-of-flight mass spectrometer (TOF/MS) was coupled to GC x GC for the identification of the resolved peaks. The response of a flame ionization detector to different compound classes was calibrated using multiple internal standards. In total, 172 compounds were identified with good match and 61 compounds with high probability value were reliably quantified. For comparative purposes, the essential oil sample was also quantified by one-dimensional gas chromatography-mass spectrometry (GC/MS) with multiple internal standards method. The results showed that there was close agreement between the two analysis methods when the peak purity and match quality in one-dimensional GC/MS are high enough. (c) 2005 Elsevier B.V. All rights reserved.
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Aims. To explore parents and professionals’ experience of family assessment in health visiting (public health nursing), with a focus on the Lothian Child Concern Model (LCCM). Background. Health visitors (HVs) currently assess families as requiring core, additional or intensive support, and offer support at a corresponding level. The majority of families are assessed as core and receive no pro-active support beyond the early days. Previous assessment tools, consisting of checklists, have been criticised as being ineffective in identifying a range of health needs and unacceptable to parents and HVs. The LCCM model was developed and introduced in the study area to promote a partnership approach with parents and assess strengths as well as difficulties in parents’ capacity to care for their child. Methods. Qualitative methods were used. Ten mothers and twelve HVs took part in individual semi-structured interviews. Results. Most mothers were aware of the assessment process but some felt that they were not involved in the decision making process. Explaining the assessment process to parents is problematic and not all HVs do so. The assessment process was stressful for some mothers. HVs find the model useful for structuring and documenting the assessment process. Many believe that most families benefit from some support, using public health approaches. Families are often assessed as core because there are insufficient resources to support all those who meet the criteria of the additional category, and managers assess caseloads in terms of families with child protection concerns. Conclusions. The study findings support the concept of “progressive universalism” which provides a continuum of intensity of support to families, depending on need. Mothers would like better partnership working with HVs. Relevance to clinical practice. The study endorses proposed policy changes to re-establish the public health role of HVs and to lower the threshold for families to qualify for support.
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The aim of this study is to investigate the impact of interconnectedness between a long-term savings and investments provider, Independent Financial Advisers (IFAs) and customers. Ritter’s (2000) framework of the effect of interconnectedness was used to analyse this triadic relationship. Conceptual studies of triadic business relationships are scarce in marketing and organisational research (Blakenburg & Johanson, 1992; Havila, Johnson & Thilenius, 2004; Ritter, 2000). However, the applicability of a triadic relationship has been tested in a number of case studies (Andersson & Mattsson, 2004; Cunningham & Pyatt, 1989; Jaaskelainen, Kuivalainen & Saarenketo, 2000; Narayandas, 2002; Odorici & Corrado, 2004; Pardo & Salle, 1994; Trimachi, 2002). This study was conducted in collaboration with one of the UK’s largest long-term savings and investments providers. A substantial proportion of the provider’s business is conducted through IFAs and thus their significance as a major stakeholder. Indeed, the majority of sales in the long-term savings and investments industry in the UK are realised through IFAs. Academic studies (Gough, 2005; Gough & Nurullah, 2009) have indicated that IFAs are the strongest distribution channel in the industry. Thus, by analysing the impact of the interconnectedness in this relationship, a strategy that can increase the relationship performance can be proposed. However, to the best of the authors’ knowledge, a study that investigates the effect of the interconnectedness in this triadic relationship has not been established. In addition, the regulatory environment which continues to face change such as the recent implementation of Retail Distribution Review (RDR) on 1st January 2013 will make the relationship more rather than less complex.
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Urquhart, C., Lonsdale, R.,Thomas, R., Spink, S., Yeoman, A., Armstrong, C. & Fenton, R. (2003). Uptake and use of electronic information services: trends in UK higher education from the JUSTEIS project. Program, 37(3), 167-180. Sponsorship: JISC
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Urquhart,C., Thomas, R., Spink, S., Fenton, R., Yeoman, A., Lonsdale, R., Armstrong, C., Banwell, L., Ray, K., Coulson, G. & Rowley, J. (2005). Student use of electronic information services in further education. International Journal of Information Management, 25(4), 347-362. Sponsorship: JISC
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Urquhart, C., Spink, S., Thomas, R., Yeoman, A., Durbin, J., Turner, J., Fenton, R. & Armstrong, C. (2004). JUSTEIS: JISC Usage Surveys: Trends in Electronic Information Services Final report 2003/2004 Cycle Five. Aberystwyth: Department of Information Studies, University of Wales Aberystwyth. Sponsorship: JISC
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Yeoman, A. J., Cooper, J. M., Urquhart, C. J. & Tyler, A. (2003). The management of health library outreach services: evaluation and reflection on lessons learned on the VIVOS project. Journal of the Medical Library Association, 91(4), 426-433. Sponsorship: Resource