804 resultados para video as a research tool


Relevância:

80.00% 80.00%

Publicador:

Resumo:

1. Introduction The success of self-regulation, in terms of enhancing older drivers’ safety and maintaining their mobility, depends largely upon older drivers’ awareness of the declines in their driving abilities. Therefore, interventions targeted at increasing older drivers’ safety should aim to enhance their awareness of their physical, sensory and cognitive limitations. Moreover, previous research suggests that driving behaviour change may occur through stages and that interventions and feedback may be perceived differently at each stage. 2. Study aims To further understand the process of driving self-regulation among older adults by exploring their perceptions and experiences of self-regulation, using the PAPM as a framework. To investigate the possible impact of feedback on their driving on their decision making process. 3. Methodology Research tool: Qualitative focus groups (n=5 sessions) Recruitment: Posters, media, newspaper advertisement and emails Inclusion criteria: Aged 70 or more, English-speaking, current drivers Participants: Convenience sample of 27 men and women aged 74 to 90 in the Sunshine Coast and Brisbane city, Queensland, Australia. 4. Analysis Thematic analysis was conducted following the process outlined by Braun and Clarke (2006) to identify, analyse and report themes within the data. Four main themes were identified.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

Successful project management depends upon forming and maintaining relationships between and among project team members and stakeholder groups. The nature of these relationships and the patterns that they form affect communication, collaboration and resource flows. Networks affect us directly, and we use them to influence people and processes. Social Network Analysis (SNA) can be an extremely valuable research tool to better understand how critical social networks develop and influence work processes, particularly as projects become larger and more complex. This chapter introduces foundational network concepts, helps you determine if SNA could help you answer your research questions, and explains how to design and implement a social network study. At the end of this chapter, the reader can: understand foundational concepts about social networks; decide if SNA is an appropriate research methodology to address particular questions or problems; design and implement a basic social network study.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

This thesis presents an interdisciplinary analysis of how models and simulations function in the production of scientific knowledge. The work is informed by three scholarly traditions: studies on models and simulations in philosophy of science, so-called micro-sociological laboratory studies within science and technology studies, and cultural-historical activity theory. Methodologically, I adopt a naturalist epistemology and combine philosophical analysis with a qualitative, empirical case study of infectious-disease modelling. This study has a dual perspective throughout the analysis: it specifies the modelling practices and examines the models as objects of research. The research questions addressed in this study are: 1) How are models constructed and what functions do they have in the production of scientific knowledge? 2) What is interdisciplinarity in model construction? 3) How do models become a general research tool and why is this process problematic? The core argument is that the mediating models as investigative instruments (cf. Morgan and Morrison 1999) take questions as a starting point, and hence their construction is intentionally guided. This argument applies the interrogative model of inquiry (e.g., Sintonen 2005; Hintikka 1981), which conceives of all knowledge acquisition as process of seeking answers to questions. The first question addresses simulation models as Artificial Nature, which is manipulated in order to answer questions that initiated the model building. This account develops further the "epistemology of simulation" (cf. Winsberg 2003) by showing the interrelatedness of researchers and their objects in the process of modelling. The second question clarifies why interdisciplinary research collaboration is demanding and difficult to maintain. The nature of the impediments to disciplinary interaction are examined by introducing the idea of object-oriented interdisciplinarity, which provides an analytical framework to study the changes in the degree of interdisciplinarity, the tools and research practices developed to support the collaboration, and the mode of collaboration in relation to the historically mutable object of research. As my interest is in the models as interdisciplinary objects, the third research problem seeks to answer my question of how we might characterise these objects, what is typical for them, and what kind of changes happen in the process of modelling. Here I examine the tension between specified, question-oriented models and more general models, and suggest that the specified models form a group of their own. I call these Tailor-made models, in opposition to the process of building a simulation platform that aims at generalisability and utility for health-policy. This tension also underlines the challenge of applying research results (or methods and tools) to discuss and solve problems in decision-making processes.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

Context: Pheochromocytomas and paragangliomas (PPGLs) are heritable neoplasms that can be classified into gene-expression subtypes corresponding to their underlying specific genetic drivers. Objective: This study aimed to develop a diagnostic and research tool (Pheo-type) capable of classifying PPGL tumors into gene-expression subtypes that could be used to guide and interpret genetic testing, determine surveillance programs, and aid in elucidation of PPGL biology. Design: A compendium of published microarray data representing 205 PPGL tumors was used for the selection of subtype-specific genes that were then translated to the Nanostring gene-expression platform. A support vector machine was trained on the microarray dataset and then tested on an independent Nanostring dataset representing 38 familial and sporadic cases of PPGL of known genotype (RET, NF1, TMEM127, MAX, HRAS, VHL, and SDHx). Different classifier models involving between three and six subtypes were compared for their discrimination potential. Results: A gene set of 46 genes and six endogenous controls was selected representing six known PPGL subtypes; RTK1–3 (RET, NF1, TMEM127, and HRAS), MAX-like, VHL, and SDHx. Of 38 test cases, 34 (90%) were correctly predicted to six subtypes based on the known genotype to gene-expression subtype association. Removal of the RTK2 subtype from training, characterized by an admixture of tumor and normal adrenal cortex, improved the classification accuracy (35/38). Consolidation of RTK and pseudohypoxic PPGL subtypes to four- and then three-class architectures improved the classification accuracy for clinical application. Conclusions: The Pheo-type gene-expression assay is a reliable method for predicting PPGL genotype using routine diagnostic tumor samples.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

The starting point of this study was to find out how the historical consciousness manifest in conceptions and experiences of Chilean refugees and their descendants. The previous research of historical consciousness has shown that powerful experiences such as the revolution and being a refugee may have an effect on historical consciousness. The purpose of this study is to solve how those experiences in the past have influenced Chilean refugees and their descendant s interpretations of the present and expectations for the future. The research material was collected by interviewing four Chilean refugees that escaped to Finland in years 1973 1976 and four young adults who represent the second generation. All second generation interviewees were born in Finland and their other parent or both parents were Chilean refugees. The two groups were not in a family relation to each other. The empirical part of the research was made by qualitative methods. The research material was collected by the method of focused interview and it was analysed by the qualitative data analysis software Atlas.ti 6.0. Content analysis was the main research tool. The previous theory of historical consciousness and the study questions was used to create the seven categories that manifest historical consciousness. The seven categories were biographical memory, collective memory, experiences of living between two cultures, idea of man, the essence of history and the reason for living, value conceptions and expectations of the future. Content analysis was based on those categories. Subcategories were based on the research material and were created during the analysis. The results of this study were made up of categories. The study revealed that experiences of revolution and of being a refugee has a significant role in the historical consciousness of the Chilean refugees. It became evident in their biographical memory being separated in three parts, in their values and in the belief of possibility of an individual to govern her own life. The second generation was also exposed to their parent s experiences in the past. The collective trauma in their parent s past has been part of their life indirectly and has affected the way they think of themselves, their concepts and their place in the present world. The active and regular retrospection in Finland by Chilean adults and special Gabriela Mistral club activities has played a big part in the construction of their historical consciousness.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

Cyclic di-GMP (c-di-GMP), a ubiquitous bacterial second messenger, has emerged as a key controller of several biological processes. Numbers of reports that deal with the mechanistic aspects of this second messenger have appeared in the literature. However, the lack of a reporter tag attached to the c-di-GMP at times limits the understanding of further details. In this study, we have chemically coupled N-methylisatoic anhydride (MANT) with c-di-GMP, giving rise to Mant-(c-di-GMP) or MANT-CDG. We have characterized the chemical and physical properties and spectral behavior of MANT-CDG. The fluorescence of MANT-CDG is sensitive to changes in the microenvironment, which helped us study its interaction with three different c-di-GMP binding proteins (a diguanylate cyclase, a phosphodiesterase, and a PilZ domain-containing protein). In addition, we have shown here that MANT-CDG can inhibit diguanylate cyclase activity; however, it is hydrolyzed by c-di-GMP specific phosphodiesterase. Taken together, our data suggest that MANT-CDG behaves like native c-di-GMP, and this study raises the possibility that MANT-CDG will be a valuable research tool for the in vitro characterization of c-di-GMP signaling factors.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

Highlights of PICES VI The state of the eastern North Pacific in the first half of 1997 The state of the western North Pacific in the first half of 1997 The status of the Bering Sea in the first eight month of 1997 Organization of fisheries, environmental and ocean science in Canada Richard James Beamish PICES-GLOBEC Climate Change and Carrying Capacity Program Epipelagic fish production in the open Subarctic Pacific: bottom up or self-regulating control? Activity Report of SCOR Working Group 105 Establishment of Marine Information Research Center: new strategy on oceanographic data management in Japan Bering Sea Ecosystem Biophysical Metadatabase: a collaborative research tool for fisheries-oceanography and ecosystem investigations

Relevância:

80.00% 80.00%

Publicador:

Resumo:

Point-particle based direct numerical simulation (PPDNS) has been a productive research tool for studying both single-particle and particle-pair statistics of inertial particles suspended in a turbulent carrier flow. Here we focus on its use in addressing particle-pair statistics relevant to the quantification of turbulent collision rate of inertial particles. PPDNS is particularly useful as the interaction of particles with small-scale (dissipative) turbulent motion of the carrier flow is mostly relevant. Furthermore, since the particle size may be much smaller than the Kolmogorov length of the background fluid turbulence, a large number of particles are needed to accumulate meaningful pair statistics. Starting from the relative simple Lagrangian tracking of so-called ghost particles, PPDNS has significantly advanced our theoretical understanding of the kinematic formulation of the turbulent geometric collision kernel by providing essential data on dynamic collision kernel, radial relative velocity, and radial distribution function. A recent extension of PPDNS is a hybrid direct numerical simulation (HDNS) approach in which the effect of local hydrodynamic interactions of particles is considered, allowing quantitative assessment of the enhancement of collision efficiency by fluid turbulence. Limitations and open issues in PPDNS and HDNS are discussed. Finally, on-going studies of turbulent collision of inertial particles using large-eddy simulations and particle- resolved simulations are briefly discussed.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

A dissertação trata de recente fenômeno juvenil urbano marcado pela identificação com um estilo musical chamado emo; os jovens que fazem parte dessa cultura juvenil se consideram mais emotivos que as outras pessoas em geral. Os emos caracterizam se também pela negação, tanto de uma identidade de grupo quanto da associação estigmatizada com um estilo específico de se vestir, se comportar e se expressar. As questões teóricas presentes nesse trabalho discutem como emos se utilizam das categorias nativas, emoções e expressões de sentimentos para representar a música, os indivíduos e o próprio grupo. A abordagem analítica central é sobre esta articulação entre música e emoção como um recurso identitário. A Internet é uma importante referência para os sujeitos pesquisados, e como ferramenta de investigação está acompanhada de considerações metodológicas sobre a etnografia virtual.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

Tomando as favelas do Rio de Janeiro como campo privilegiado de análise, esta dissertação busca trazer para o centro da discussão a forma a partir do qual os moradores destes territórios da cidade vivenciam e externalizam sua percepção da injustiça e lidam com a frustração de seus desejos e aspirações, quando confrontados com a ação policial. Partindo da observação das possíveis interferências de uma ação de policiamento, as Unidades de Polícia Pacificadora (UPPs), na esfera pública local do Morro do Andaraí, buscou-se entender como agem seus moradores diante do contexto sócio-político atual de reconfiguração do pensamento estatal em relação à atuação da segurança pública na cidade. Quais representações sociais os moradores organizam para formular uma rede de relações entre seus membros e como estas representações estabelecem objetivos e procedimentos específicos para interpretar e pensar a realidade cotidiana. E, em que medida a ação do Estado interfere, efetivamente, de modo a reconfigurar a esfera pública local, são questões que foram abordadas ao longo do trabalho teórico e empírico. Partindo de uma abordagem holística, que considerou observar os fatos humanos como totalidades, adotou-se uma postura reflexiva diante do objeto de estudo e dos sujeitos que o constroem em seu cotidiano no desenrolar da esfera pública local. Desta forma, junto a uma extensa pesquisa bibliográfica foram associados um trabalho de campo exploratório e a aplicação de um instrumento de investigação não diretivo a um conjunto de moradores, posteriormente as falas recolhidas dos moradores foram tratadas segundo a técnica de Análise de Conteúdo. Percebe-se nas representações sociais dos moradores, o entendimento de que as ordens ideológica, política e econômica que compõem o Estado continuam a olhar para as favelas como o espaço onde identificam a desordem e a causa dos problemas sociais enfrentados pelo conjunto da cidade. Espaço que por isso precisa ser reordenado, pacificado para acabar com ideia da cidade partida em frações marginais. Por fim, relacionando a conjuntura atual vivenciada nas favelas ocupadas com os conceitos de policiamento comunitário, busca-se compreender em que medida as UPPs podem ou não contribuir para as mudanças tão esperadas nas ações de policiamento das favelas. O momento atual é de observação atenta e discussão constante para a constituição de uma cidade de mais direitos, pacífica não apenas para os moradores do asfalto

Relevância:

80.00% 80.00%

Publicador:

Resumo:

在视频会议系统中,服务器端多媒体数据流的存储转发有其特殊的背景和要求,因而需要一个高性能的多媒体数据流的缓冲机制,该机制的高效与否是制约视频会议系统性能的关键因素之一。在传统的生产者/消费者模型的基础上,结合多媒体业务的特殊环境,提出了一个新的数据流的缓冲机制模型,并在此基础上实现了一套集中式的多点视频会议系统。

Relevância:

80.00% 80.00%

Publicador:

Resumo:

信息技术的不断进步使得软件产品的应用领域不断扩大,同时软件产品的规模也在迅速膨胀。软件产品的开发模式已由最初的手工作坊式开发逐渐转变为大规模的工程化软件开发。这使得资源调度问题逐渐成为软件项目管理的核心研究内容之一。 软件项目与传统工业项目相比具有如下两个显著特点:其一是软件项目对人力资源能力的依赖性非常高;其二是软件项目在开发过程中具有的不确定性因素较多,也就是风险较高。这两个特点决定了传统工业调度方法不能很好地适用于软件项目管理,同时也为软件项目资源优化调度问题研究提出了新的挑战。需要根据软件项目的特点研究适合的资源调度方法为软件项目管理工作提供支持。 本文的研究工作旨在通过对软件项目的结构进行分析和描述,在建立软件项目核心要素模型的基础上,考虑软件项目高人力资源能力依赖性和高风险性两大特征,由人力资源能力和风险作为驱动因素,对软件项目中人力资源和项目缓冲两大核心资源进行优化分配和调度,以提高软件项目的资源利用效率和软件项目执行的稳定性。本文的主要贡献有: (1)建立了软件项目资源优化调度研究框架QMMT和项目核心要素模型PTHR。 QMMT研究框架由问题驱动(Question Driven),模型描述(Model Description),方法研究(Method Research)和工具验证(Tool Validation)四个模块构成。四个模块之间既存在顺序关系也存在信息反馈机制,框架具有良好的适应性和可扩展性。实践表明,QMMT研究框架对研究软件项目资源优化调度问题具有良好的指导作用。本文中涉及软件项目资源优化调度的多个研究问题均遵循QMMT研究框架。 通过对软件项目所包含的各个要素及要素之间的关系进行定义和描述,我们建立了软件项目核心要素模型PTHR。模型对软件项目的四个要素:项目(Project)、任务(Task)、人力资源(Human Resource)、风险(Risk)以及四个要素之间的关系进行了形式化定义和描述。PTHR模型涵盖了软件项目的核心要素并具有良好的可扩展性,可以为资源优化调度中具体问题的分析、算法的设计、流程的安排以及工具开发提供底层支持。PTHR模型是本文后续方法中相关系列子模型的基础模型。 (2) 提出了软件项目中任务-人员匹配的三维匹配模型3D-THM和基于3D-THM模型的任务人员优化分配方法。 任务人员匹配是人力资源调度的基础。3D-THM(3 Dimensional model for Task Human Matching)模型通过对人力资源的技术能力、性格能力和职业规划进行描述,以及对任务的技术能力需求、性格能力需求和职业规划需求进行描述,设定相应的多因素匹配算法,为任务-人员的全面优化匹配提供支持。实验表明,3D-THM模型较好的描绘了软件项目中任务-人员优化匹配问题,能够体现软件项目的高人力资源能力依赖性。模型实例化后所得到的匹配方法和相应的原型工具可为软件项目资源优化调度以及软件过程建模提供人员优化匹配支持,能够提高项目管理人员的工作效率,提升项目人员对任务分配的满意度。 (3) 提出了基于人员可用性的人力资源调度方法。 在对任务人员进行优化匹配的基础上,通过综合考虑人力资源能力和工作时间实现了基于人员可用性的人力资源调度方法。方法结合软件项目的结构特征,建立了任务人员可用性约束模型THACM(Task Human resources Availability Constraints Model)。基于THACM模型实现了在给定资源集合、任务集合下的人力资源自动分配和项目进度的自动安排。方法可有效解决采用矩阵组织结构的企业所面临的低资源可见性问题,协助其提高人力资源的利用效率。 (4)提出了基于任务优先级的抢占式人力资源调度方法PP-HAS。 在对人力资源可用性进行考虑的基础上,为了解决多项目环境下常见的资源冲突问题,我们提出了基于任务优先级的抢占式人力资源调度方法PP-HAS(Task Priority Based Preemptive Human Resource Scheduling Method)。方法首先建立了综合考虑进度、成本、质量三方面因素的基于价值的任务优先级模型VBTPM(Value Based Task Priority Model),将该任务优先级模型与过程Agent技术结合,通过设计支持抢占的人力资源调度流程,实现了多过程Agent协商下的人力资源优化调度。方法通过抢占和再计划实现了人力资源的动态高效利用,能够为资源冲突的解决以及项目的再计划工作提供决策支持。 (5)提出了风险驱动的软件项目缓冲资源分配方法。 项目缓冲的合理分配是降低风险对项目进度造成影响的重要手段。我们在软件项目资源调度方法中加入对风险因素的考量,基于软件项目中风险的特征,建立了简化的风险模型RRM(Reduced Risk Model)。基于RRM模型提出了风险驱动的项目缓冲分配方法,旨在软件项目的执行效率和稳定性二者之间进行权衡。模拟实验的结果表明,相对于传统关键链项目管理理论中尾部集中的项目缓冲分配方法,风险驱动的项目缓冲分配方法能够在确保对项目平均执行工期产生较小影响的同时,显著降低项目执行时计划变更的发生频率。该缓冲分配方法与项目模拟工具可以帮助项目经理确定合适的项目缓冲时间长度以及缓冲分配方案,进而提高软件项目计划的可信性和执行的稳定性。

Relevância:

80.00% 80.00%

Publicador:

Resumo:

栉孔扇贝是我国北方一种重要的贝类养殖品种。自1997年以来爆发的栉孔扇贝大规模死亡,给地区经济造成了重大损失并且已经严重威胁着扇贝养殖业的健康发展。然而,到目前为止,对扇贝免疫防御分子机理的了解还很少,深入研究扇贝免疫应答的分子机制是认识和了解病害发生和实现病害控制的重要途径。本研究采用了EST大规模测序和3’RACE的方法,从栉孔扇贝cDNA文库中克隆到一个凝集素基因CfLec-2,并对功能进行了研究。 CfLec-2 cDNA全长708bp,5’非翻译区(Untranslated Region, UTR)含有59bp,3’非翻译区含有163bp,具有典型的多聚腺苷酸加尾信号序列AATAAA和多聚腺苷酸尾巴,开放阅读框(Open Reading Frame, ORF )含有486bp,编码162个氨基酸残基,该多肽的理论分子量为16.8 kDa,等电点为4.54。利用SignalP分析,发现其信号肽的剪切位置在VEA-QSL之间。经BLASTP比对分析可知,CfLec-2基因编码的蛋白与人的Brevican,Anguilla japonica的C-type lectin-1和C-type lectin-2, Rattus norvegicus的CD23有较高的相似性,其中与Brevican的一致性有37%。Clustal W多序列比对发现该多肽具有标准长型C型凝集素所必须的6个保守半胱氨酸和相对保守的糖识别位点。用SMART(Small Modular Architecture Research Tool)软件分析发现其具有一个保守的糖识别结构域(Carbohydrate-recognition Domain, CRD),氨基酸序列上第49、125、141、149位置上的半胱氨酸参与形成糖识别结构域,而位于N末端的第21和32位上的两个半胱胺酸形成额外的一个二硫键,位于115、116和117上的Glu、Pro、Asp则构成了糖识别位点。 将编码CfLec-2成熟肽段的cDNA序列克隆进pET32a(+)载体中,并在大肠杆菌Rosetta-gami(DE3)中重组表达CfLec-2。重组蛋白利用其具有的His tag纯化并复性后发现CfLec-2可以凝集溶血葡萄球菌,且凝集过程不需要钙离子的参与。并且,CfLec-2对大肠杆菌TOP10F’有微弱的抑菌活性,对溶壁微球菌、溶血葡萄球菌和鳗弧菌则没有抑菌活性。这一结果说明,CfLec-2可能不仅参与对入侵微生物的识别过程,而且可能作为效应分子起到了直接杀灭入侵微生物的作用。 本研究发现CfLec-2具有和以前在栉孔扇贝报道的CFLec-1完全不同的功 能,说明栉孔扇贝利用不同的凝集素来识别不同的病原,同时也暗示栉孔扇贝中可能有更多不同功能的凝集素有待发现。研究结果丰富和发展了海水无脊椎动物免疫学的内容,对进一步了解扇贝固有免疫的机制,实现养殖扇贝疾病防治具有重要参考价值。

Relevância:

80.00% 80.00%

Publicador:

Resumo:

扇贝是我国海水养殖的重要品种,但自1994年以来,养殖扇贝陆续爆发的大规模死亡,不但造成了巨大的经济损失,而且直接威胁到现有产业的生存和发展。引起扇贝大规模死亡原因是多方面的,其主要原因是养殖环境恶化、扇贝种质衰退和抗病力下降。因此,深入研究扇贝免疫防御机制,探讨提高机体抗病力的有效途径和方法,改良种质和培育抗病品系,无疑是解决目前困扰扇贝养殖业健康可持续发展的必经之路。 Toll样受体(TLRs)家族是新近发现的模式识别受体(PRRs),参与识别病原体相关的分子模式(PAMPs),在天然免疫系统中起着非常重要的作用。哺乳动物中Toll样受体信号通路还参与诱导树枝状细胞成熟、参与免疫耐受、参与凋亡发生发展、介导非感染性因素的识别等,被视为联系天然免疫和获得性免疫的桥梁。同时果蝇的Toll信号通路也是不具备获得性免疫的果蝇赖以抵御病毒、细菌和真菌感染,介导天然免疫反应的重要信号通路。 本研究采用大规模EST测序方法,结合Genome Walker库的构建和cDNA末端快速扩增技术,从栉孔扇贝克隆得到CfToll-1、CfMyd88、CfTRAF6和CfCactus这四个Toll样受体信号通路基因的全长cDNA,同时用荧光实时定量PCR技术检测了这些基因的组织分布及在脂多糖(LPS)和肽聚糖(PGN)刺激下的表达规律。 栉孔扇贝Toll样受体(CfToll-1)的cDNA序列全长4308 bp,包含5’非翻译区(UTR)211 bp,3597 bp的开放阅读框,500 bp的3’UTR,最后为18个腺嘌呤的ploy A 尾巴。开放阅读框编码1198个氨基酸的多肽,该多肽的估计分子量为137.41kd,估计的等电点为5.62,该多肽有信号肽,具有一个预测的跨膜区,因此是一种跨膜蛋白。经BLAST比对,CfToll-1基因与节肢动物多种Toll蛋白高度的相似性。SMART(Simple Modular Architecture Research Tool)软件分析,CfToll-1包含典型的Toll样受体的结构:富含亮氨酸的重复序列的胞外区(leucine-rich repeats, LRR),一段跨膜结构域,以及胞内区的TIR结构域(Toll/IL-1 receptor homologous region)。利用Real-time RT-PCR发现CfToll-1mRNA在扇贝体内普遍存在于血细胞、肌肉、外套膜、心、性腺和鳃组织中。利用体外培养的原代血细胞系研究不同浓度LPS刺激后CfToll-1的表达变化,结果显示低剂量(100ng.mL-1 )LPS 使CfToll-1 mRNA表达量减小,该变化在1.5h、3h 和9h组差异显著,虽然在6h组表达量稍有恢复,但尚未达到对照水平;用1μg.mL-1LPS处理细胞时, 6h组CfToll-1表达量明显上调,约为对照水平的2倍。证实细菌结构脂多糖对CfToll-1基因的表达有影响,且这种影响有剂量依赖效应。 栉孔扇贝Myd88同源基因(CfMyd88)的cDNA序列全长1554bp,包含5’UTR 427 bp,1101bp的开放阅读框,最后为18个腺嘌呤的ploy A 尾。CfMyd88的开放阅读框可编码367个氨基酸的多肽,该多肽的估计分子量为42.37kD,估计的等电点为5.71。利用SMART程序分析发现CfMyd88编码了Death和TIR结构域, 这两个结构域是Myd88特征结构。BLAST程序发现扇贝的序列与数据库哺乳动物的Myd88基因高度同源。原代培养的扇贝血细胞在受到PGN刺激后,CfMyd88 mRNA表达在1.5小时开始下调,直到9小时下调至对照表达量的1/10,证实肽聚糖结构对CfMyd88基因的表达有影响。 栉孔扇贝TRAF6同源基因(CfTRAF6)的cDNA序列全长2510bp,包含5’UTR 337 bp,1965bp的开放阅读框,3’UTR 208bp,最后为21 个腺嘌呤的ploy A 尾巴。CfTRAF6开放阅读框编码655个氨基酸的多肽,该多肽的估计分子量为74.09kD,估计的等电点为6.01。InterPro Scan在线分析发现CfTRAF6有典型的TRAF蛋白家族的特征结构,包括的一个指环结构,两个锌指结构,一个MATH (the meprin and TRAF homology)结构域以及Coiled-coil区域。CfTRAF6的序列与数据库多物种的TRAF6高度同源,同源性最高的是乌贼序列(Identity=68)和鼠类(Identity=45%)。利用Real-time RT-PCR,发现CfTRAF6在各组织普遍存在,在性腺中的表达最高。原代培养的扇贝血细胞在受到不同浓度PGN刺激后,与CfMyd88的情况一样,CfTRAF6的表达量变化减少,且这种变化随剂量的增加更加明显。 栉孔扇贝Cactus同源基因(CfCactus)的cDNA序列全长2488bp,包含5’UTR 181 bp,840bp的开放阅读框, 3’UTR 1467bp,最后为19个腺嘌呤的ploy A 尾巴。CfCactus的开放阅读框编码279个氨基酸的多肽,该多肽的估计分子量为31.37 kD;估计的等电点为4.74,与果蝇的Cactus基因的等电点相近(4.5)。利用SMART程序分析发现CfCactus主要编码了ANK结构域(ankyrin repeats)。Cactus基因为哺乳动物NF-κB抑制蛋白IκB的同源分子,BLAST 程序发现扇贝的序列与数据库多物种的Cactus或IκB基因高度同源。同源性最高的是太平洋牡蛎(Identity=35%)和圆尾鲎(Identities = 44%)。对CfTCactus mRNA在扇贝的血细胞、性腺、 肠的组织表达进行分析,并同时与CfTRAF6和CfMyd88的表达量进行了对比,发现CfCactus的表达水平明显高于这两个基因,而且CfTRAF6的基因表达量也高于CfMyd88,表现出级联放大效应。正常情况下,三个基因在性腺的表达量最高,推测这条通路可能和发育等功能密切相关。 通过本研究我们首次在双壳类软体动物找得到与果蝇Toll蛋白家族高度同源的CfToll-1基因,同时发现其他三个在Toll样受体信号传递过程中起重要作用的基因,其中包括在软体动物中获得的第一个Toll样受体的接头分子-CfMyd88基因,该结果直接证明软体动物具有与哺乳动物和节肢动物高度类似Myd88依赖的Toll样受体信号通路。同时通过这些基因组织分布的研究以及细菌结构LPS和PGN对这条通路上基因表达的影响,证明扇贝Toll信号通路可能与在果蝇中一样,参与扇贝的发育和免疫防御等多种功能。

Relevância:

80.00% 80.00%

Publicador:

Resumo:

香烟小包装在线实时检测系统是一种烟草行业产品包装检测设备,具有广阔的应用前景。在现代生产过程中,生产速度越来越快,对产品质量的要求也越来越高。烟草企业在香烟的生产过程中,从烟叶制丝到卷、接、包装都已经实现了自动化。香烟小包装的外观质量,反映了烟厂的技术装备水平,涉及到企业的形象、信誉问题,同时,有质量缺陷的香烟小包装被市场反馈回企业,也会带来企业成本的增加。 随着计算机软件、硬件技术的发展,以及机器视觉理论的完善,采用机器视觉的方法来检测香烟小包装的外观质量,已经开始应用。机器视觉在检测方面具有先天优势检测速度快、分辨能力高、规范化程度高、可重复性好。采用现代机器视觉技术来进行香烟小包装外观质量的检测,可以大大降低检验人员的劳动强度,提高产品的质量,减少烟厂的人力成本和管理成本,改善企业形象。 本文分析了国内外烟包包装质量检测的许多方法,设计了一套基于DSP的香烟小包装外观质量检测系统,可以对香烟小包装进行实时检测,达到实时剔除有包装质量缺陷的香烟小包装的目的。 从机器视觉的角度出发,本文阐述了视觉检测系统的工作原理、总体机构及系统的工作流程,同时对比各种硬件特性,进行了光源、传感器、相机、镜头及DSP芯片的选型,着重介绍了图像处理算法,尤其是本系统中用到的图像配准、模板匹配以及各种缺陷的识别进行了详细的描述,并给出了程序在DSP中的优化方法。 本文对设计的系统进行了一系列的实验和测试,结果表明,本系统具有速度快,总体检测效果好,稳定性好的特点,可以达到香烟小包装实时检测的要求。