活細胞成像

內(nèi)容概要

《活細胞成像（第二版）》旨在探討英語冠詞語義特征和相關(guān)的語境因素如何交互作用并影響英語冠詞二語習(xí)得。作者從語言涌現(xiàn)論角度出發(fā)，提出英語冠詞習(xí)得過程是一個復(fù)雜適應(yīng)系統(tǒng)，由含有眾多因素和主體的子系統(tǒng)組成，冠詞習(xí)得是各類主客體因素相互影響和共同作用的結(jié)果。研究主要關(guān)注語義子系統(tǒng)和語境子系統(tǒng)在不同層面的交互作用及其對二語學(xué)習(xí)者冠詞習(xí)得的影響，揭示了英語冠詞替代型誤用產(chǎn)生的原因，對英語冠詞教學(xué)具有一定的現(xiàn)實意義?！痘罴毎上瘢ǖ诙妫肥状卧谟楷F(xiàn)論框架下研究英語冠詞二語習(xí)得，為涌現(xiàn)理論在語言和語言習(xí)得領(lǐng)域的應(yīng)用提供了實證基礎(chǔ)，有利于促進語言涌現(xiàn)理論的進一步發(fā)展。

作者簡介

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書籍目錄

Contents序前言AbstractvAcknowledgementsChapter 1 Introduction1.1 Goals of research1.2 Research background1.3 Key research questions1.4 Organization of the bookChapter 2 Semantic and Pragmatic Analysis of English Articles:An Overview2.1 Introduction2.2 Semantic analysis of English articles2.2.1 Definiteness and English articles2.2.2 Specificity and English articles2.2.3 Semantic complexity of English articles2.3 Pragmatic analysis of English articles2.3.1 The context-driven nature of semantic features2.3.2 P-sets(Hawkins,1978,1991)2.3.3 Relationship between semantic features and contextual factors2.4 SummaryChapter 3 L1 and L2 Acquisition of English Articles:A Critical Review3.1 Introduction3.2 Tasks facilitating the acquisition of English articles3.3 L1 developmental studies3.3.1 Maratsos's(1976)egocentricity account3.3.2 Wexler's Lack of Maximality Presupposition account3.3.3 The specific/non-specific effect account3.4 Studies of L2-English article acquisition3.4.1 Semantic Wheel and the classification of NP types3.4.2 L2 article acquisition studies under the Bickertonian framework3.4.3 Jarvis's(2002)study from a discourse perspective3.4.4 Fluctuation Hypothesis and Syntactic Misanalysis Account3.5 Comments on previous research3.6 SummaryChapter 4 Interaction and L2-English Article Acquisition:Questions and Hypotheses4.1 Introduction4.2 Interaction under the emergentist framework4.2.1 Emergentism in SLA4.2.2 Interaction:importance and ignorance4.2.3 Outlining the interactions to be studied4.3 Exploring interaction in detail4.3.1 Interaction of different semantic features4.3.2 Interaction of different contextual factors4.3.3 Interaction of semantic features with contextual factors4.4 Research questions and hypotheses4.5 SummaryChapter 5 Study 1:Elicited Production5.1 Introduction5.2 Predictions5.3 Methodology5.3.1 Participants5.3.2 Materials and procedures5.3.3 Data coding procedures5.4 Results5.4.1 The forced elicitation task5.4.2 The written interview5.5 Discussion5.5.1 The role of specificity in L2 article choices5.5.2 Different effects of contextual factors5.5.3 Interaction of semantic features with contextual factors5.6 SummaryChapter 6 Study 2:Acceptability Judgment6.1 Introduction6.2 Background and predictions6.2.1 Background6.2.2 Predictions about uniqueness6.2.3 Predictions about hearer knowledge6.2.4 Predictions about specificity6.3 Methodology6.3.1 Participants6.3.2 Task and materials6.3.3 Procedure6.4 Results6.4.1 Computing uniqueness6.4.2 Uniqueness vs.existence6.4.3 Hearer knowledge6.4.4 Specific vs.non-specific6.5 Discussion6.5.1 The asymmetry of performance in different contexts6.5.2 The influence of partitivity6.5.3 Influence of specificity in article comprehension6.5.4 Semantic knowledge contributes to context sensitivity6.6 SummaryChapter 7 General Discussion and Conclusions7.1 Introduction7.2 Major findings7.3 General discussion7.3.1 Effects of specificity and partitivity on L2 learners' knowledge of definiteness7.3.2 Factors influencing L2 learners' context-sensitivity7.3.3 Interaction of semantic features with contextual factors7.4 Conclusions7.4.1 The Interaction Account:a summary of the study7.4.2 Implications of the present study7.4.3 Limitations and suggestions for further research7.5 SummaryReferencesAppendixesAppendix A Article-choice Test(Version 1)Appendix B Article-choice Test(Version 2)Appendix C The Answer Sheet of Article-choice TestAppendix D The Consent Form for Study 2Appendix E Test Items of Study 2Appendix F L2 Learners' Mean Rating of Items in Study 2Appendix G Native Speakers' Mean Rating of Items in Study 2List of Tables2.1 Semantic complexity of English articles3.1 The classification of NP types under the Semantic Wheel Model3.2 Predicted article choices in L2-English(the Fluctuation Hypothesis)3.3 Predicted article choices in L2-English(based on the Fluctuation Hypothesis)3.4 Predicted article choices in L2-English(Trenkic's view)5.1 Predicted article choices in L2-English(the present study)5.2 Biodata of participants of Study 15.3 Reason types and examples5.4 Native speaker results for Test Version 1(N=7)5.5 Native speaker results for Test Version 2(N=7)5.6 L2-learner results for Test Version 1(N=27)5.7 L2-learner results for Test Version 2(N=28)5.8 Article choices in [+definite,+spec,-ESK] contexts5.9 Descriptive data of a-overuse in [+definite,+spec,-ESK] contexts5.10 Reasons provided by L2 learners and native speakers5.11 First mention as reasons provided for L2 article choices6.1 Biodata of the participants of Study 26.2 Features of each category6.3 Mean ratings by category(1=unacceptable,4=acceptable)6.4 Mean ratings of Categories 1 and 6(with or without hearer knowledge)6.5 Mean ratings in Categories 6 and 76.6 Low proficiency L2 learners' mean rating in Categories 6 and 77.1 The distinction of the and a(Translated from Zhang,2007:67)List of Figures3.1 Article grouping cross-linguistically(Two articles)5.1 Difference of a-overuse between L2 learners and native speakers in [+definite,+spec,-ESK] context(Version 1)5.2 Difference of a-overuse between L2 learners taking version 1 and version 2 in [+definite,+spec,-ESK] context(target:the)5.3 Differences between L2 learners and native speakers concerning three major reasons5.4 Categories of reasons provided by L2 learners and native speakers5.5 Reasons provided for correct article choices5.6 Reasons provided for substitution errors of English articles5.7 Detailed results of reasons associated with definiteness5.8 Detailed results of reasons associated with specificity6.1 Comparing performance across Categories 1,2,and 36.2 Comparing performance across Categories 1 and 2 vs. 4 and 56.3 Comparing performance across Category 1 vs. 6

章節(jié)摘錄

版權(quán)頁：   插圖：    活細胞的二維結(jié)構(gòu)照明 OMX系統(tǒng)的3D-SIM能夠?qū)鹘y(tǒng)熒光顯微鏡的分辨率提高一倍。但是，整套技術(shù)仍然有兩個比較大的缺陷。①在3D- SIM中，為了獲取一張照片，需要在3個角度上改變5個照明相位，一共拍攝15張照片。因此在拍攝過程中，光漂白比較嚴重，獲取最終照片的速度也比較慢。由于采用旋轉(zhuǎn)的光柵以提供不同角度上的結(jié)構(gòu)照明，整個系統(tǒng)的成像速度更加緩慢，光柵旋轉(zhuǎn)一個角度大致需要2s。為了保證圖像重建的準確性，在成像過程中，樣品的移動范圍不能超出100nm，因此，目前的OMX系統(tǒng)，獲取一個z軸光學(xué)切片系列的最短時間為lOs，在這段時間內(nèi)，細胞內(nèi)容物的移動范圍往往超出100nm。這個缺陷可以使用兩個方法解決，一個方法是使用全內(nèi)反射熒光（TIRF）的方法以獲取單層的圖像，在這種情況下，獲得一張最終照片只需要在3個角度3個相位上拍攝9張照片。另一個方法是使用光線調(diào)制器，衍射光柵角度的改變可以不依賴于光學(xué)部件的物理旋轉(zhuǎn)。結(jié)合這兩種方法，獲取一張二維TIRF超高分辨率照片的時間可以低于100ms （Kner et al.2009）。 TIRF TIRF可以實現(xiàn)100nm的z軸分辨率，同時大幅度減少背景的干擾。它通過光線在蓋玻片和樣品之間發(fā)生全反射時，照射全反射界面上樣品。在全反射發(fā)生的界面上，會在與蓋玻片平行的方向上產(chǎn)生消逝波，而且消逝波的強度隨著離開界面距離指數(shù)衰減（第36章）。多波長TIRF系統(tǒng)已經(jīng)在Sedat實驗室的OMX系統(tǒng)上安裝，它將傳統(tǒng)的寬場照明導(dǎo)人多波長單模光纖實現(xiàn)照明。通過改變聚焦平面的位置，它可以快速改變?nèi)肷浣且詫崿F(xiàn)不同波長的激發(fā)光在同一焦平面上實現(xiàn)全內(nèi)反射成像。 3D TIRF 由于OMX系統(tǒng)可以非常精確地控制發(fā)生全反射時的臨界角，因此使用OMX系統(tǒng)可以在大于臨界角的一系列角度上獲得TIRF圖像。使用這種方法，逐漸照射離界面較遠的樣品，獲得一系列z軸光學(xué)切片的圖像。后期的圖像處理使得圖像的z軸分辨率可以達到很高。目前，使用該技術(shù)可以獲得z軸分辨100nm，厚度1μm的樣品圖像。 活細胞成像中的圖像處理 OMX系統(tǒng)的首要設(shè)計目標就是在快速觀察活細胞的過程中，在有限的照明強度和很短的曝光時間下，仍然能夠收集到足夠的信號以獲得最大的信噪比。分析快速成像過程中產(chǎn)生的數(shù)據(jù)則需要物體識別和跟蹤，以跟蹤快速運動而且信噪比有限的顆粒（Jaqaman et al.2008）。這些識別和定量分析工具對活細胞成像至關(guān)重要（第13、15、16章）。 另外一個未來極有前途的改進方向是使用圖像處理工具改善活細胞成像中信號的信噪比和隨后的分析。OMX系統(tǒng)獲得的三維圖像信息，利用去卷積技術(shù)，根據(jù)點擴散函數(shù)計算樣品中焦平面信號的位置，進一步提高信噪比（Swedlow et al.1997; Wal-lace et al.2001; Parton and Davis 2006）。此外，采用去噪聲的算法也可以極大的改善圖像的質(zhì)量。去噪聲的算法依據(jù)樣品信號在二維或者三維空間有規(guī)律的分布，而噪聲信號則無規(guī)律的分布這一特性，從而過濾掉無規(guī)律的信號。對于二維信號，去噪聲相對簡單，常用高斯或者中值濾波加以處理。對于三維信號，由于其本身具有的空間位置的信息，則可以進一步提高信噪比。最近，更加先進的算法也陸續(xù)被開發(fā)出來。將去噪聲技術(shù)應(yīng)用于四維成像中，圖像的信噪比可以得到進一步提高。

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《生命科學(xué)實驗指南系列:活細胞成像(第2版)》可以作為活細胞成像的入門讀物，也可以作為一線科研人員的理論基礎(chǔ)讀物和具體實驗步驟指南。同時，《生命科學(xué)實驗指南系列:活細胞成像(第2版)》還可以作為活細胞成像課程的教科書。

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