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[转载]Linux系统学习笔记3:grep用法
zhenghui2915 2012-9-9 20:44
转载地址: http://bbs.chinaunix.net/thread-1687220-1-1.html 关于Linux Grep命令使用的详细介绍 1. grep简介 grep (global search regular expression(RE) and print out the line,全面搜索正则表达式并把行打印出来)是一种强大的文本搜索工具,它能使用正则表达式搜索文本,并把匹配的行打印出来。Unix的grep家族包括grep、egrep和fgrep。egrep和fgrep的命令只跟grep有很小不同。egrep是grep的扩展,支持更多的re元字符, fgrep就是fixed grep或fast grep,它们把所有的字母都看作单词,也就是说,正则表达式中的元字符表示回其自身的字面意义,不再特殊。Linux使用GNU版本的grep。它功能更强,可以通过-G、-E、-F命令行选项来使用egrep和fgrep的功能。 grep的工作方式是这样的,它在一个或多个文件中搜索字符串模板。如果模板包括空格,则必须被引用,模板后的所有字符串被看作文件名。搜索的结果被送到屏幕,不影响原文件内容。 grep可用于shell脚本,因为grep通过返回一个状态值来说明搜索的状态,如果模板搜索成功,则返回0,如果搜索不成功,则返回1,如果搜索的文件不存在,则返回2。我们利用这些返回值就可进行一些自动化的文本处理工作。 2. grep正则表达式元字符集(基本集) ^ 锚定行的开始 如:'^grep'匹配所有以grep开头的行。 $ 锚定行的结束 如:'grep$'匹配所有以grep结尾的行。 匹配一个非换行符的字符 如:'gr.p'匹配gr后接一个任意字符,然后是p。 * 匹配零个或多个先前字符 如:'*grep'匹配所有一个或多个空格后紧跟grep的行。 .*一起用代表任意字符。 rep'匹配Grep和grep。 匹配一个不在指定范围内的字符,如:' rep'匹配不包含A-R和T-Z的一个字母开头,紧跟rep的行。 (..) 标记匹配字符,如'(love)',love被标记为1。 锚定单词的开始,如:' 锚定单词的结束,如'grep'匹配包含以grep结尾的单词的行。 x 重复字符x,m次,如:'0'匹配包含5个o的行。 x 重复字符x,至少m次,如:'o'匹配至少有5个o的行。 x 重复字符x,至少m次,不多于n次,如:'o'匹配5--10个o的行。 w 匹配文字和数字字符,也就是 ,如:'Gw*p'匹配以G后跟零个或多个文字或数字字符,然后是p。 W w的反置形式,匹配一个或多个非单词字符,如点号句号等。 b 单词锁定符,如: 'bgrepb'只匹配grep。 3. 用于egrep和 grep -E的元字符扩展集 + 匹配一个或多个先前的字符。如:' +able',匹配一个或多个小写字母后跟able的串,如loveable,enable,disable等。 ? 匹配零个或多个先前的字符。如:'gr?p'匹配gr后跟一个或没有字符,然后是p的行。 a|b|c 匹配a或b或c。如:grep|sed匹配grep或sed () 分组符号,如:love(able|rs)ov+匹配loveable或lovers,匹配一个或多个ov。 x,x,x 作用同x,x,x 4. POSIX字符类 为了在不同国家的字符编码中保持一至,POSIX(The Portable Operating System Interface)增加了特殊的字符类,如 是A-Za-z0-9的另一个写法。要把它们放到 或 ]。在Linux下的grep除fgrep外,都支持POSIX的字符类。 文字数字字符 文字字符 数字字符 非空字符(非空格、控制字符) 小写字符 控制字符 非空字符(包括空格) 标点符号 所有空白字符(新行,空格,制表符) 大写字符 十六进制数字(0-9,a-f,A-F) 5. Grep命令选项 -? 同时显示匹配行上下的?行,如:grep -2 pattern filename同时显示匹配行的上下2行。 -b,--byte-offset 打印匹配行前面打印该行所在的块号码。 -c,--count 只打印匹配的行数,不显示匹配的内容。 -f File,--file=File 从文件中提取模板。空文件中包含0个模板,所以什么都不匹配。 -h,--no-filename 当搜索多个文件时,不显示匹配文件名前缀。 -i,--ignore-case 忽略大小写差别。 -q,--quiet 取消显示,只返回退出状态。0则表示找到了匹配的行。 -l,--files-with-matches 打印匹配模板的文件清单。 -L,--files-without-match 打印不匹配模板的文件清单。 -n,--line-number 在匹配的行前面打印行号。 -s,--silent 不显示关于不存在或者无法读取文件的错误信息。 -v,--revert-match 反检索,只显示不匹配的行。 -w,--word-regexp 如果被和引用,就把表达式做为一个单词搜索。 -V,--version 显示软件版本信息。 6. 实例 要用好grep这个工具,其实就是要写好正则表达式,所以这里不对grep的所有功能进行实例讲解,只列几个例子,讲解一个正则表达式的写法。 $ ls -l | grep '^a' 通过管道过滤ls -l输出的内容,只显示以a开头的行。 $ grep 'test' d* 显示所有以d开头的文件中包含test的行。 $ grep 'test' aa bb cc 显示在aa,bb,cc文件中匹配test的行。 $ grep ' ' aa 显示所有包含每个字符串至少有5个连续小写字符的字符串的行。 $ grep 'w(es)t.*' aa 如果west被匹配,则es就被存储到内存中,并标记为1,然后搜索任意个字符(.*),这些字符后面紧跟着另外一个es(),找到就显示该行。如果用egrep或grep -E,就不用""号进行转义,直接写成'w(es)t.*'就可以了。
个人分类: Linux|1893 次阅读|0 个评论
Editors and reviewers are NOT gods
热度 1 zuojun 2012-9-8 14:37
Fight when you can, against the journal editor or reviewers. Don't always assume they are right and you are wrong, even when it's about English expression. ps. Why should I care? Here is the background info. A reviewer said "topography is not a driving mechanism," and asked the authors to use "topographic-induced xxx." Ok, I may also prefer "topographically-induced xxx," BUT it is NOT wrong to use "topographically-driven xxx." Don't argue with me, just google and see 15+ million citations are out there.
个人分类: Scientific Writing|2656 次阅读|2 个评论
时钟基因研究的信息分析与知识发现
xupeiyang 2012-8-27 13:35
最新研究进展: 瑞士日内瓦大学的Ueli Schibler教授揭示了一个身体体温节律影响“时钟基因”表达和同步局部振荡器的分子机制。该研究是与洛桑联邦理工学院(EPFL)的一个研究小组合作完成,还揭示了一种参与解毒和药物代谢的蛋白DBP生成是如何受到每日温度变化的调节的。这一研究发布在最新一期(8月23日)的《科学》(Science)杂志上。 http://www.ebiotrade.com/newsf/2012-8/2012824115655755.htm circadian gene expression 时钟基因表达 Important words Topics Authors Affiliations Journals Year Clustered by topic 分析平台 http://arrowsmith.psych.uic.edu/cgi-bin/arrowsmith_uic/AnneOTate_summarize.cgi?ID=22294t=fw=ch 前20名 Important words重要词汇 文献量Frq 1 clock 3251 2 circadian 4619 3 bmal1 499 4 per2 495 5 per1 457 6 suprachiasmatic 1121 7 cry1 215 8 scn 821 9 rhythm 2806 10 oscillator 794 11 clockwork 165 12 mper1 164 13 mper2 158 14 cryptochrome 189 15 cry2 140 16 erbalpha 121 17 cca1 108 18 period1 99 19 toc1 97 20 period2 97 Filtered Important words 过滤重要词汇(知识发现) 文献量Frq 1 clock 3251 2 bmal1 499 3 per2 495 4 per1 457 5 cry1 215 6 scn 821 7 oscillator 794 8 mper1 164 9 mper2 158 10 cryptochrome 189 11 cry2 140 12 cca1 108 13 toc1 97 14 timeless 158 15 per3 93 16 lhy 86 17 constan 69 18 frq 80 19 kaic 61 20 npas2 55 Topics 研究主题 文献量 Frq 1 Circadian Rhythm 3783 2 Gene Expression Regulation 1511 3 RNA, Messenger 1313 4 Transcription Factors 971 5 Biological Clocks 964 6 Period Circadian Proteins 917 7 Nuclear Proteins 877 8 Light 874 9 Suprachiasmatic Nucleus 797 10 Transcription, Genetic 705 11 Gene Expression 641 12 Cell Cycle Proteins 541 13 CLOCK Proteins 528 14 Gene Expression Regulation, Plant 495 15 Trans-Activators 467 16 Drosophila Proteins 442 17 Amino Acid Sequence 432 18 Mutation 423 19 Base Sequence 421 20 Photoperiod 416 Journals 期刊 文献量 frq 1 Proc Natl Acad Sci U S A 209 2 J Biol Rhythms 177 3 PLoS One 143 4 Chronobiol Int 130 5 Plant Physiol 130 6 J Neurosci 129 7 Science 126 8 J Biol Chem 119 9 Eur J Neurosci 115 10 Brain Res Mol Brain Res 97 11 Endocrinology 97 12 Brain Res 88 13 Curr Biol 87 14 Nature 83 15 Neuroscience 80 16 Biochem Biophys Res Commun 79 17 Plant Cell 69 18 Plant Mol Biol 69 19 Cell 63 20 Neurosci Lett 61 其他分析结果 circadian gene expression.docx
个人分类: 知识发现|5985 次阅读|0 个评论
蛋白质和基因的命名规则
热度 4 liwenbianji 2012-6-28 12:42
在 描述基因、基因mRNAs或由其编码的蛋白质水平的变化时,经常会因错误使用命名规则而引发混淆。如果作者一会儿提及基因表达水平,一会儿转至蛋白质水 平,再过一会又回到基因,这只会乱上加乱,尤其是当基因和蛋白质同名时。因此,作者应确切地告知读者你提及的到底是基因还是蛋白质。不同物种有不同的命名 规则,但一般来说,基因名称应写成斜体,蛋白质则采用正体。大小写常用于区分不同物种:一般地,对于小鼠、大鼠和鸡,基因名称首字大写,其余小写;对于 人、灵长类和某些家禽/家畜,基因名称均使用大写字母。在描述mRNA时一般使用基因名称(如,“levels of p53 mRNA”),也可用“for”来加以连接(如,“levels of the mRNA for p53”)。“表达”(expression)一词通常用于描述基因表达,如果用于描述蛋白质和mRNA水平,就会引发混乱;因此,在提及蛋白质时,建议 不用“表达”一词,而是直接改用“level”(或“levels”)。应高度注意所提及物种的适用命名规则;在文章中只要提及蛋白质、基因或mRNA的 名称,应确保其是明白无误的。 • “Expression of the Igf1 gene was increased in our transgenic mice” (这里在提及基因时使用了斜体并加上“gene”一词,读者能够一目了然) • “The levels of IGF1 mRNA were elevated in our patient group” (这是人类基因的正确命名规则) • “The serum IGF1 levels were elevated in the transgenic mice” (这里很显然提及的是蛋白质,使用大写字母是适宜的,尽管物种是小鼠,因为这是小鼠蛋白质的正确命名规则) Protein and gene nomenclature One very common cause of confusion is use of the incorrect nomenclature to describe changes in the levels of genes, their mRNAs or the proteins that they encode. Constant changing from describing gene expression levels to protein levels and back again can also add to the confusion, especially because the names are often the same. Therefore, it needs to be completely clear to the reader exactly what level you are talking about. Nomenclature differs among species, but generally gene names should be described in italics and protein names in normal font. Case (upper vs lower) is often used to distinguish between species: generally, for mouse, rat and chicken, gene names are spelt with an upper case first letter and the rest in lower case; for humans, primates and some domestic species, gene names are spelt with all capital letters. Descriptions of mRNAs generally use the gene name (for example, “levels of p53 mRNA”) or you can refer to the mRNA “for” a given protein (for example “levels of the mRNA for p53”). The word “expression” is usually used to describe gene expression and can induce confusion when used to describe protein and mRNA levels; in most cases referring to proteins the word “expression” can simply be replaced with the word “level” (or “levels”). Be aware of the correct nomenclature for your species of subject and ensure that everywhere you refer to a protein, gene or mRNA by name in the text it is completely clear which of those you are referring to. • “Expression of the Igf1 gene was increased in our transgenic mice” (use of italics and the word “gene” ensure that no confusion is possible here). • “The levels of IGF1 mRNA were elevated in our patient group” (correct nomenclature for human genes). • “The serum IGF1 levels were elevated in the transgenic mice” (here, it is clear that the protein is being referred to; capitals are appropriate in this case, even though the species is mouse, because it is the correct nomenclature for the mouse protein). Dr Daniel McGowan 分子神经学博士 理文编辑学术总监
29469 次阅读|4 个评论
[转载]The context of gene expression regulation
wilber983046 2012-6-1 11:42
[转载]The context of gene expression regulation
转自: http://f1000.com/reports/b/4/8
1652 次阅读|0 个评论
Do you know how to use "Excuse me" in five different ways?
zuojun 2012-4-23 05:44
I was updating my Blog on my experience on MU572 from HNL to PVG. I realized that I used "Excuse me" in a way that most of us never learned in class (in China). My blog is at http://blog.sciencenet.cn/home.php?mod=spaceuid=306792do=blogid=562351 So, I decided to google the phrase. Here is the result from http://en.wiktionary.org/wiki/excuse_me excuse me ( US ) Said as a request to repeat information. (Mandarin: 請再説一遍 ) Said as a request for an individual's attention. (Mandarin: 請問 ) Said as a request to pass. ( Mandarin: trad. 借過 , simpl. 借 过 ) Sorry , as an apology. (Mandarin: 對不起 ) Said as a request for an apology. (There is no translation, but I hope you know what it means from the way I used it to express myself on MU572. I don't think it's the language, but my tone, that expressed myself so well that the person immediately said: 對不起 , 對不起 , which is Chinese for sorry--in case you don't know any Chinese. )
个人分类: From the U.S.|3313 次阅读|0 个评论
基因表达调控的绝缘体元件
bioysy 2012-3-21 23:58
第一次看到这个名词:insulator element(金山词霸把它译成绝缘体) A role for insulator elements in the regulation of gene expression response to hypoxia Nucl. Acids Res. (2012) 40(5): 1916-1927 first published online November 8, 2011 doi:10.1093/nar/gkr842 摘要:Hypoxia inducible factor (HIF) up-regulates the transcription of a few hundred genes required for the adaptation to hypoxia. This restricted set of targets is in sharp contrast with the widespread distribution of the HIF binding motif throughout the genome.(提出问题:HIF binding motif多,target少;顺式作用元件多,调节的目标蛋白少) Here, we investigated the transcriptional response of GYS1 and RUVBL2 genes to hypoxia to understand the mechanisms that restrict HIF activity toward specific genes(以两个具体的基因为研究模型). GYS1 and RUVBL2 genes are encoded by opposite DNA strands and separated by a short intergenic region (~1 kb) that contains a functional hypoxia response element equidistant to both genes. However, hypoxia induced the expression of GYS1 gene only(特殊情况出现) . Analysis of the transcriptional response of chimeric constructs derived from the intergenic region revealed an inhibitory sequence whose deletion allowed RUVBL2 induction by HIF(发现inhibitory sequence,这个就是绝缘子). Enhancer blocking assays, performed in cell culture and transgenic zebrafish, confirmed the existence of an insulator element within this inhibitory region that could explain the differential regulation of GYS1 and RUVBL2 by hypoxia(进一步实验). Hence, in this model, the selective response to HIF is achieved with the aid of insulator elements(为什么调节靶蛋白少了?因为顺式作用元件后面接了个绝缘子,呵呵有点意思) . This is the first report suggesting a role for insulators in the regulation of differential gene expression in response to environmental signals. 启示: 根据这个例子基因间序列也可能是有功能的,所以图位克隆的时候如果预测基因区无多态性,可以暂缓考虑跳楼.这个绝缘子估计目前用任何软件都预测不出来.
个人分类: 基因表达|3306 次阅读|0 个评论
journal of diabetes and its complications
wjs2000 2012-2-23 18:12
简介:J DIABETES COMPLICAT杂志属于医学行业,“内分泌学与代谢”子行业的偏低级别杂志。 投稿难度评价:影响因子不高,影响力也比较小,审稿时间也偏长,但容易投中。 审稿速度:较慢,6周-12周 级别/热度:黑 Medsci评语:冷门杂志,关注人极少。 journal of diabetes and its complications 期刊发表中国人的SCI文章列表,共计 7 篇文章 Guo QH; Lu JM; Pan CY; Lu ZH; Zou XM; Mu YM The kidney expression of matrix metalloproteinase-9 in the diabetic nephropathy of Kkay mice 2008 摘要 | google Wong J; Molyneaux L; Zhao DM; Constantino M; Gray RS; Twigg SM; Xu ZR; Yue DK Different accelerators to early-onset Type 2 diabetes: a comparison of Anglo-Celtic and Chinese patients 2008 摘要 | google Ren XY; Li YN; Qi JS; Niu T Peroxynitrite-induced protein nitration contributes to liver mitochondrial damage in diabetic rats 2008 摘要 | google Heng XP; Chen KJ; Hong ZF; He WD; Chu KD; Chen WL; Chen XZ; Zheng HX; Chen L; Yang LQ; Guo F; Lin ML Glucose endothelial cytotoxicity and protection by Dan Gua-Fang, a Chinese herb prescription in huVEC in hyperglycemia medium 2009 摘要 | google Xie XS; Wang YJ; Zuo C; Fan JM; Li XJ A case report of an effective treatment for diabetic foot ulcers with integration of traditional Chinese medicine and Western medicine 2009 摘要 | google Tam VHK; Lam EPK; Chu BCY; Tse KK; Fung LM Incidence and progression of diabetic retinopathy in Hong Kong Chinese with type 2 diabetes mellitus 2009 摘要 | google Lin Y; Ye SD; Chen Y; Li XC; Yang GW; Fan AH; Wang YX The effect of simvastatin on the serum monocyte chemoattractant protein-1 and intracellular adhesion molecule-1 levels in diabetic rats 2009 摘要 | google
4163 次阅读|0 个评论
方法:你所做的工作
热度 1 liwenbianji 2012-2-2 10:44
“方法” 部分应包含足够的信息以供其他研究者准确重复你描述的试验;如果其中有关键信息遗漏,别人就无法完全重复你的实验条件;这会引起结果不一致,有可能造成误会,甚至还会被人指责造假。所以“方法”部分要力求全面。 “ 方法”部分应该使用过去时态,例如:“sections were stained with…” and “data were analyzed using…”。但是在提及图表时应使用现在时,例如:“The patients’ clinical characteristics are listed in Table 1”。 此外,当你在叙述某个事物的定义或当前对它公认的看法时也要用现在时,例如:“the cells were subjected to hypoxia, which induces HIF-1 expression…”。这句话中,虽然实验部分是用的过去时,但由于缺氧(hypoxia) 导致HIF-1是一个普遍现象而不是限定于本文的结果,因此后面半句应该用现在时。 要列出所有试剂的供应商以及设备的厂家;有的期刊还要求列出其地址,即国家、州(如为美国)和市。叙述设备、试剂盒、试剂的时候应该用常用术语来具体描述,不要只用厂商的专门术语或只写型号。比如,不要写成:“Absorbance in each well was measured at a wavelength of 492 nm using a Beckman Coulter AD 340C”,因为大多数人都对Beckman Coulter AD 340C没有任何概念;应该写成:“Absorbance in each well was measured at a wavelength of 492 nm using a multi-well plate reader (AD 340C, Beckman Coulter)”,或者“Absorbance in each well was measured at a wavelength of 492 nm using an AD 340C multi-well plate reader (Beckman Coulter Inc, Fullerton, CA, USA)”。 “方法”部分只能包括最终得出结果的实验方法。如果某个试验失败了或者没能提供你需要的结果,而且你已经决定论文中不提这些结果,那么也没有必要去谈其试验方法。用适当的子标题把各种不同目的的材料和方法分类。如果期刊设有“补充方法 ”(Supplementary Methods)部分,则可用这部分来详述细节,并让纸面刊出的“方法”部分保持简短。新方法应该详细叙述以便他人重复;标准和常用技术只须引用文献即可,但如果你的方法和文献有差异之处应予说明。尤其要保证所有单位都正确,实验条件(如时间、温度)都清楚。最后,如果开展了统计学分析来评价研究结果的意义,则应在“方法”的最后一段叙述你的统计学方法,包括所选择的显著性阈值。 实例 “…homogenates were spun at 10,000 × g and 4 °C for 12 min” 这句话包含了时间、温度两个重要细节。而: “…homogenates were spun at 10,000 × g” 和更简化的 “homogenates were centrifuged” 两个句子中就遗漏这些细节。这些细节有可能对得到你的结果很重要,所以应该给出。 同理,不要只写:“Then, 10 μl of a propidium iodide solution was added to the cells”,因为这对读者毫无意义,除非他们知道该溶液的浓度。应该写成:“Propidium iodide was added to the wells to a final concentration of 0.5 μg/ml”。 下图节选自《The Journal of Clinical Investigation》所发表的一篇论文(doi:10.1172/JCI37155;经同意转载)的方法部分。它显示了“方法”部分的各种要素以及他们如何组合的。 核查清单 1. 用清楚的子标题列出用于不同目的的方法和材料。 2. 研究方法用过去时。 3. 新方法给出充足的细节以便他人重复。 4. 已有方法可用参考文献。 5. 写明厂家/供应商,必要时应提供地址。 6. 说明所采用的统计学方法。 英文原文 Methods: what you did The methods section of your manuscript should contain sufficient information for a capable researcher to accurately repeat the experiments you describe; if essential information is left out, the exact conditions might not be replicated, leading to different results, potential misunderstandings, or worse, accusations of falsification. Thus, the methods section needs to be comprehensive. The methods section should be written in the past tense; for example, “sections were stained with…” and “data were analyzed using…”. An exception to this is references to tables or figures in the manuscript, for example “The patients’ clinical characteristics are listed in Table 1”. Another exception is when providing a definition or describing the current consensus on something: for example, “the cells were subjected to hypoxia, which induces HIF-1 expression…”. Here, although what was done is described in the past tense, the fact that hypoxia induces HIF-1 is described in the present tense because it is a general phenomenon not limited to the present paper. The suppliers of all reagents and the manufacturers of all equipment used should be listed; some journals also request that the locations, that is, city, state (if in the USA) and country, of these companies are provided. When describing equipment, kits, or reagents, you should use familiar terms to define the particular item you are describing, rather than just a manufacturer-specific term or model number. For example rather than writing “Absorbance in each well was measured at a wavelength of 492 nm using a Beckman Coulter AD 340C”, which would be meaningless to the majority of readers, you should write “Absorbance in each well was measured at a wavelength of 492 nm using a multi-well plate reader (AD 340C, Beckman Coulter)” or perhaps “Absorbance in each well was measured at a wavelength of 492 nm using an AD 340C multi-well plate reader (Beckman Coulter Inc, Fullerton, CA, USA)”. Methods should only be included if the results of the described experiments are provided; if an experiment you performed didn’t work, or didn’t provide the results you needed, and you have opted to leave the results out of your paper, then there is no need to describe the associated methods. Use appropriate subheadings to separate materials and methods with different purposes. If available, use a Supplementary Methods section to provide detailed information so that the printed methods section can be kept brief. Novel techniques need to be described in detail so that they can easily be replicated, but established and commonly used techniques can be referenced as long as any variations between the method used in the present study and that described in the cited study are clearly described. Above all, be precise and ensure that all units are correct and all conditions (for example, times and temperatures) are clear. Finally, if any statistical analysis was performed to assess the significance of your data, describe the statistical methods used, including the threshold(s) selected for significance, at the end of the methods section. Examples The sentence “…homogenates were spun at 10,000 × g and 4 °C for 12 min” includes the important details of time and temperature that would have been missing if the author simply wrote “…homogenates were spun at 10,000 × g”, or even more simply “homogenates were centrifuged”. These details could have been essential to obtaining the result you did, and so should be explained. Similarly, rather than saying “Then, 10 μl of a propidium iodide solution was added to the cells”, which is meaningless unless the reader knows the concentration of the propidium iodide solution, you should write “Propidium iodide was added to the wells to a final concentration of 0.5 μg/ml”. The figure below, showing a couple of excerpts from the methods section of paper published in The Journal of Clinical Investigation (doi:10.1172/JCI37155; reproduced with permission), indicates the important components of a methods section and how these fit together. Checklist 1. Clear subheadings for methods/materials with different purposes, with materials described first 2. Methods described in past tense 3. Novel methods described in full detail, sufficient for a capable researcher to reproduce 4. Established methods referenced to previous literature 5. Suppliers/manufacturers provided, including locations if requested 6. Statistical methods described Dr Daniel McGowan 分子神经学博士 理文编辑学术总监
2613 次阅读|1 个评论
[转载]Epigenetics
syfox 2012-1-5 11:48
Laboratory Head Professor Emma Whitelaw Summary Epigenetics is the study of mechanisms which modify DNA structure in subtle ways, and thus change gene expression, without influencing the DNA base sequence. Characteristics like physical appearance and personality traits are commonly considered to be the result of interactions between genetic and environmental factors alone. However, genetically identical individuals, raised in similar environments, for example identical twins, show variation in some phenotypes. These variations may be the result of epigenetic differences between these individuals. At this stage, the research is best carried out using mouse models but, in the near future, Professor Whitelaw hopes to be able to study humans directly. A successful grant application has resulted in the establishment of the Australian Centre for Cancer Epigenetics at the Institute. The centre has expanded the DNA sequencing and imaging capacities available at QIMR, not only in cancer research, but also for scientists working in other areas. The laboratory has been developing a mouse model of fetal alcohol syndrome and anticipate that this will inform the community of the effects of maternal consumption of alcohol during pregnancy. http://www.qimr.edu.au/page/Lab/Epigenetics/Epigenetics_student_projects/
个人分类: 学习|1825 次阅读|0 个评论
与金陵十三钗无关的十三个问题
热度 30 考槃在涧 2011-12-30 19:50
问一:为什么日本兵那么残暴? 战争中的人性都是如此。德军也好不到哪里去,而美军英军也屡有虐囚强奸事件,往前推,屠城在这个星球上每个国家都曾经发生过。 几千年人性本身基本没什么变化,进步的是观念和制度。制度包含日内瓦公约在内的一系列共识和惩罚措施,如武器禁运乃至联合出兵。 很多年前我认为贵党宣传的不干涉内政正确,现在觉得这是一个看似正确实则没有底限的观点。没错,大多数时候大家应该谁也别管谁,但如果你的邻居正在暴打他老婆,就算你不去劝架,起码也该报个警。当某些行为明显超越了人类当下共识时,别人来揍你活该。 什么是共识?共识不是所有人都认可,只要多数人认可即算共识,至于是过半还是 2/3 ,应该不需要那么精准。一言堂不会也不可能产生共识,所以天天在 AV 里讲统一思想,讲了 60 年,还是统一不了。 这些事情也说明人性的相通性。 问二:国军和 G 军,到底谁抗日更多? 三大类事实:一、国军参战的部队,很多都是当时和后来的精锐。比如 74 军和参加滇缅抗战的部队。打仗的是张灵甫、杜聿明、郑洞国等人。 二、国军阵亡的部队经常成建制,比如守常德的 57 师。 三、国军打了八年之后没有变强,而 G 军越来越强。 如果你知道这三个事实,相信得出答案并不难。 事情过去七十年了,也许争个是非曲直没有多大意义,但是请不要忘记那些在抗战中死去的国军士兵,他们比打内战的更值得怀念。 中华民族真正的纪念日应该是日军投降那一天,而不是每年放七天那个假,那个节日应该只是某些人的节日。 问三:妓女代替处女,是否不公平? 没有处女也没有妓女,我看到的是姐姐代替妹妹,男孩代替女孩。 女人只有在卖身的时候才是妓女,走进教堂她们就是普通人。 换个角度,是风霜保护了纯真。 那些学生甚至并不完全清楚要发生什么,而妓女们 ---- 这个词在这里是褒义 ---- 她们起码对一切有心理准备。 问四:为什么妓院要富丽堂皇,而教堂要高大肃穆? 因为程序本身能让人获得认同和归属感。一系列的程序能让人发生根本变化,心理学称为行为内化。 你在妓院,每天看着春宫图,你会觉得两腿一张也没什么大不了,你在教堂,每天看着十字架,你会觉得自己渺小、有罪。 中国古代有一系列的程序,比如婚礼、皇家礼节、拜师礼等等。这些礼节其实等同于现代的制度。你每月去祭天,心里就会尊重天;同样,如果你能参与到民主的每一个环节,程序能够让你明白什么是真正的民主。 说中国人现有素质不适合民主是不正确的。中国人现有素质是体制造成的。你在不民主体制里看到的行为和态度,然后推导出这些人不适合民主,显然是错误的。人的“素质”是可塑的,证据之一就是中国人到了国外可以变得守规矩而外国人在中国也会变得狡猾。 制度不是万能,祭天的也有不敬天的,但是如果没有这一整套的制度去影响人,你又能指望什么? 都说佛在心中座,但如果天下的寺庙都关门,还会有佛吗?程序和制度远比所谓的国民性和素质重要。 道德失范的根本原因在于,古老的礼节(制度)完全打破了,而又不采纳新的制度。 摸着石头过河这样的话纯属搪塞,人家明明用得好的制度你不用,对你有利的就说学习西方先进经验,对你不利的就说不适合中国人民,口才真好! 问五:妓女和总统的共同点是? 为了和谐,我把切尔曼( Chairman )换成了总统。 共同点是她们都能让嫖客爽。 问六:妓女和总统的不同点是? 1、 妓女可满足不同阶层嫖客需求,而总统主要满足萌牛铁的部之类嫖客的需求; 2、 妓女用自己的身体满足嫖客,而总统用别人的身体满足萌牛铁的部。 问七:妓女和女学生的共同点是? 她们都曾经善良、纯真、“干净”过。是妓院让女孩成为妓女,教堂让女孩成为学生。没有那个女孩适合做妓女,妓院会帮助他们成为花魁;没有哪个女孩不适合成为学生,她们只需要一个还算合格的神父。 民主也是如此,没有哪个人生来就适合民主,也没有哪种文化不适合民主。骗人的最高境界就是,你本来不瘸,但一番忽悠就把你拐卖了。赵本山真是个大哲学家。 在电影里,妓女们在教堂焕发出人性的光辉。 问八:妓女和女大学生的不同点是? 一些人已经饱经风霜,一些人依然纯真。纯真的人,总会经风霜,而经过风霜的,还有没有找回纯真的机会? 电影的回答是可以。当这些女人换了造型,她们不论是外表还是心态都发生了变化。你曾是什么人并不重要,大部分时候大部分人只是尽心尽力地演好了自己的角色;花个花脸就是丑角,穿上蟒袍就是王侯,没那么神秘。 在独裁体制里,你就是奴才,不想做奴才的,要么在监狱,要么在海外。在民主体制里,你会成为公民,也没什么神秘。不想做公民?拜托,要不你移民别移美国,移朝鲜行不? 问九:妓院和坏制度的共同点是? 他们都强迫或引诱女人出卖身体,同时还努力让她们习惯这种生活甚至以之为乐;他们都鼓吹赚钱第一有钱可以赎身,他们都可以“搞”活经济。妓院和坏制度都可以把女学生变为妓女,在这件事上,贵党干得很成功。 妓院里老鸨很可能也曾是妓女,坏制度里的老鸨也如此。 问十:妓院和坏制度的不同点是? 妓院只强迫或诱使一部分女人出卖身体,而坏制度裹挟所有人。 问十一:妓院换个老板会不会不同? 不会有本质的不同,可能有些老鸨不打骂姑娘,起码她们爱护自己的摇钱树。 但是,你既然能取缔妓院,问什么不能取缔坏的制度呢? 你把妓院烧了不是为了换老板,是为了不要有妓院这样的坏制度存在。 至于老鸨,她可以改行做化妆品代理 ---- 如果她愿意在你烧妓院之前就改行的话,妓院可以作为她的私产。 问十二: 凭什么相信妓院烧了,老鸨改行就不会有新的妓院? 在封闭社会里很容易如此。但是在开放系统里也许会有反复,但总的方向是确定的。前面说过,有公约,有共识,有制裁。 制裁受苦的是普通人,还不如太平过日子? 嗯,看来萌牛奶还不够毒。 问十三:汉奸是否都罪大恶极? 中学以前痛恨汉奸,大学后知道了很多事实逐渐改变了看法。至少不是所有汉奸都该死该被判刑。电影里也有类似思想。 相对于战争年代的汉奸,和平年代窃取国家资源并转移海外的人更可恶。在战争年代很多时候人没有选择,而在和平年代: You can make money without evil 可惜的是,和平年代的罪恶远比战争来得隐蔽, 而往往,正是和平年代隐蔽的罪恶和对罪恶的姑息, 带来了战争。 而每一个姑息的背后都有千万个好的理由和借口。
个人分类: 求道|4794 次阅读|33 个评论
[转载]i.e.,etc., 和 e.g.的用法和区别
flyada 2011-11-12 16:11
i.e. 是拉丁文 id est 的缩写,它的意思就是“那就是说,换句话说”,等同于“that is,in other words” ,目的是用来 进一步 解释前面所说的观点。 e.g. 是拉丁文 exempli gratia 的缩写,它的意思是“举个例子,比如”,等同与“for example”,目的就是用几个例子来说明前面的观点。 etc.就比较好理解了,它是 etcetera 的缩写,意思是“等等”,相当于“and so on” e.g. 和 etc. 不能出现在同一句话中,因为 e.g. 是表示泛泛的举几个例子,并没有囊括所有的实例,其中就已经包含“等等”,如果再加一个 etc. 就画蛇添足了,例如下面这句话就是错的: Writing instructors focus on a number of complex skills that require extensive practice (e.g., organization, clear expression, logical thinking, etc.)
个人分类: 授业解惑|1916 次阅读|0 个评论
祝贺陈生弟校友取得重要研究成果
xupeiyang 2011-8-30 08:19
上海交通大学瑞金医院神经科,中科院健康科学研究所神经变性疾病研究组的研究人员发表了题为“DJ-1 modulates the expression of Cu/Zn-superoxide dismutase-1 through the Erk1/2–Elk1 pathway in neuroprotection”的文章,揭示了DJ-1在神经保护中抗氧化应激作用的新机制。 这一研究成果发表在Annals of Neurology杂志上。 http://onlinelibrary.wiley.com/journal/10.1002/(ISSN)1531-8249 Annals of Neurology Country : United States Subject Area : Neuroscience Subject Category : Neuroscience (miscellaneous) Publisher : John Wiley Sons Inc. . Publication type : Journals. ISSN : 03645134, 15318249 Coverage: 1977-2010 H Index : 182 Scope: Annals of Neurology publishes articles of broad interest with potential for high impact in understanding the mechanisms and treatment of Annals of Neurology publishes articles of broad interest with potential for high impact in understanding the mechanisms and treatment of diseases of the human nervous system. All areas of clinical and basic neuroscience, including new technologies, cellular and molecular neurobiology, population sciences, and studies of behavior, addiction, and psychiatric diseases are of interest to the journal. ( source ) 陈生弟,男,1955年出生,教授、主任医师、医学博士、博士生导师,附属瑞金医院党委副书记、神经科主任、神经病学教研室主任,研究所所长。1978年毕业于原上海第二医科大学,1986年获得原上海第二医科大学神经病学硕士学位,1991年获得原上海第二医科大学神经病学博士学位。 陈教授在以帕金森病和老年性痴呆为代表性的神经变性疾病的基础及临床研究领域取得了丰硕的成果和业绩,为我国神经病学科的快速发展和在国内外学术地位的迅速提升做出了重要贡献,8次应邀在国外学术会议上作大会报告及担任会议主席,在国际上尤其是在帕金森病及运动障碍性疾病研究领域已具有相当的知名度。先后主持、参加完成了包括国家“973”、“863”计划在内的科研基金40项,获得国家及省部级科技进步奖项19项。 陈教授发表学术论文300余篇,其中SCI收录近40篇;主编(译)7部以及参编近30部专著;当选“百千万人才工程”国家级人选,获得包括国家有突出贡献中青年专家、全国中青年医学科技之星、首批上海市医学领军人才、第六、八届市科技精英提名奖、市十佳优秀启明星、十佳医师、首届和第二届高校优秀青年教师、卫生系统青年最高奖“银蛇奖”二等奖,上海交通大学医学院高尚师德奖等在内的许多项荣誉称号。
个人分类: 神经科学|2863 次阅读|0 个评论
English expression: pay it forward
热度 3 zuojun 2011-5-26 03:56
Many people tell me: "Thank you for your help (with English editing). I hope I can help other people some day." This makes me very happy. I am sure there is a Chinese expression for such a kind thought. In English, it is called "pay it forward." (Clearly, I don't expect these people to edit my English writing, though they may point out the mistakes and typos I have in my Blog.) If we can all help others without expecting payback and people pay it forward, what a wonderful world we can all live in! Note: The expression " pay it forward " is used to describe the concept of asking that a good turn be repaid by having it done to others instead.
个人分类: Thoughts of Mine|3590 次阅读|6 个评论
Useful English expressions: beyond love and hate
zuojun 2011-4-28 03:03
What is the "opposite" of “I love you”? You can start with “I hate you.” If you don’t want to sound like a 5-year-old child, you can try: I dislike that guy. I can’t stand that idiot. I can’t bear looking at him.
个人分类: From the U.S.|2314 次阅读|0 个评论
It’s the tone (that matters), stupid!
zuojun 2010-11-4 05:56
I dont mean to be rude; I am just borrowing a phrase I heard often in the past. Ms. LI Xia is correct about the way What a shame is used normally. Of course, one might say What a shame in a VERY COLD tone, and think privately: Hell, you deserve it! Or one may say: Shame on you with a big smile on her face, just to tease you Note: It's the economy, stupid was a phrase in American politics widely used during Bill Clinton 's successful 1992 presidential campaign against George H. W. Bush .
个人分类: From the U.S.|3785 次阅读|2 个评论
"Multiword expressions"在汉语中的研究
jhx0129 2010-4-16 11:05
我本只是个工科的,要做的只是算法研究亦或是应用系统的研究。想不到在"Multiword expressions"这个问题上却不得不让我补上基础一直不行的语文知识。"Multiword"中的"word"对应到汉语中应该是什么?词吗?字吗?语素吗?小句吗? 先看看我们借用这个外来概念我们都把什么看作MWE."习语,成语,固定短语,命名实体等整体意义不是简单的局部意义之和的非组合性单元,(如:惊弓之鸟,翘辫子,江泽民,九江),和"胡温新政","陈江会","科学网","新华社","地震灾区"等组合性单元"。 再来看看"词"的定义"最小的意义单位"『王力』,
个人分类: 未分类|8 次阅读|0 个评论
时间序列表达数据分析工具
anny424 2009-9-11 18:30
参考文献: Microarray data analysis and mining approaches Francesca Cordero , Marco Botta and Raffaele A. Calogero Corresponding author: Raffaele A. Calogero, Department of Clinical and Biological Sciences, University of Torino, Italy. Briefings in Functional Genomics and Proteomics 2008 6(4):265-281; doi:10.1093/bfgp/elm034 Although two-sample differential expression analysis is probably the most common experiment, multi-series time-course microarray experiments are useful approaches for exploring biological processes. In these types of experiments, the researcher is frequently interested in studying gene expression changes over time and in evaluating trend differences between the various experimental groups . The large amount of data, multiplicity of experimental conditions and the dynamic nature of the experiments pose great challenges to data analysis. A comprehensive review of research in time series expression data analysis was published by Bar-Joseph in 2004 . Recently, maSigPro Conesa has published two methods for time-course microarray data analysis . One is maSigPro , and is part of Bioconductor packages. ...This will ultimately be used to find what are the profile differences between experimental groups. ANOVA-SCA The other is ANOVA-SCA and combines ANOVA-modeling and a dimension reduction technique to extract targeted signals from data bypassing structural noise. ANOVA-SCA basically applies PCA to the estimated parameters in each source of variation of an ANOVA model. ANOVASCA seems an effective approach for separating the data variability present in a complex time course experiment to extract the signal of interest from noisy data . fully Bayesian approach Angelini and coworkers have recently described a fully Bayesian approach to detect differentially expressed genes in time-course experiments. Their approach allows to explicitly use biological prior information and deals with various technical difficulties that arise in microarray timecourse experiments such as a small number of observations, non-uniform sampling intervals, missing or multiple data and temporal dependence between observations for each gene. Authors compared their method with that implemented in R-package time course and in the EDGE software claiming that their algorithm provides results which are much closer to a biologists choice and delivers a lower percentage of false positive and negative answers than other algorithms . Fischer and coworkers have compared methods for identifying differentially expressed genes on time-series microarray data simulated from artificial gene networks. They suggest the use of ANOVA variants of Cui and Churchill on the bases of simulated data and Efron and Tibshiranis empirical Bayes Wilcoxon rank sum test in the case experimental background cannot be effectively corrected. CHPM Shi has instead proposed an approach, based on a probabilistic continuous hidden process model ( CHPM ), to identify the various biological processes involved in a specific biological experiment. This method integrates time series expression data with GO biological processes , modelling the observed gene expression levels as being generated by a combination of multiple GO biological processes whose activity levels vary over time. OTHER TOOLs: STEM Short Time-series Expression Miner (STEM) (~8 time points or fewer). STEM allows researchers to identify significant temporal expression profiles and the genes associated with these profiles and to compare the behavior of these genes across multiple conditions. STEM is fully integrated with the Gene Ontology (GO) database supporting GO category gene enrichment analyses for sets of genes having the same temporal expression pattern. STEM also supports the ability to easily determine and visualize the behavior of genes belonging to a given GO category or user defined gene set, identifying which temporal expression profiles were enriched for these genes. DREM Dynamic Regulatory Events Miner (DREM) takes as input time series gene expression data and input that associates transcription factors with the genes they regulate . This regulatory information could come from Chromatin Immunoprecipitation (ChIP)-chip experiments or transcription factor binding site motif information. The transcription-factor gene regulation input does not need to be associated with specific time points. DREM after executing a computational method described in outputs an annotated dynamic regulatory map based on the data that can be interactively explored. The dynamic regulatory map highlights bifurcation events in the time series, that is places in the time series where sets of genes which previously had roughly similar expression level diverge. Often these bifurcation events can be explained by transcription factors selectively regulation a certain subset of genes. DREM annotates these events with transcription factors potentially responsible for them. DREM is related to another time series expression analysis software the Short Time-series Expression Miner ( STEM ) . While STEM focuses on identifying independent significant patterns in short time series data , DREM provides a global map of the gene regulation of the time series . The DREM method also incorporates in transcription factor-gene regulation information. DREM also is not limited to analyzing short time series data as STEM is. Some of the input file formats and options are the same in DREM as in STEM, in particular options related to gene filtering and the Gene Ontology analysis. For these aspects of DREM which are the same as in STEM, the relevant portions of the STEM manual have been incorporated into this manual. BiGGEsTS An integrated environment for the biclustering ( Madeira and Oliveira, 2004 ) analysis of time series gene expression data . Biclusters may be analyzed with Gene Ontology annotations to find out which contain statistically relevant biological information or even filtered or sorted according to several numerical and statistical criteria. 应用举例: STEM Comprehensive transcriptional profiling of NaCl-stressed Arabidopsis roots reveals novel classes of responsive genes Yuanqing Jiang and Michael K Deyholos* Address: Department of Biological Sciences, University of Alberta, Edmonton, Canada BMC Plant Biology 2006, 6:25 doi:10.1186/1471-2229-6-25 用STEM做了聚类,然后以GOTerm为层次标注各term中包含哪些cluster,有几个。 Combined analysis reveals a core set of cycling genes Yong Lu 1 , Shaun Mahony 2 , Panayiotis V Benos 2 , Roni Rosenfeld 3 , Itamar Simon 4 , Linda L Breeden 5 and Ziv Bar-Joseph 1 ,3 1 Department of Computer Science, Carnegie Mellon University, Forbes Avenue, Pittsburgh, Pennsylvania 15213, USA 2 Department of Computational Biology, University of Pittsburgh Medical School, Lothrop Street, Pittsburgh, Pennsylvania 15213, USA 3 Machine Learning Department, Carnegie Mellon University, Forbes Avenue, Pittsburgh, Pennsylvania 15213, USA 4 Department of Molecular Biology, Hebrew University Medical School, Jerusalem, Israel 91120 5 Basic Sciences Division, Fred Hutchinson Cancer Center, Fairview Avenue N, Seattle, Washington 98109, USA Genome Biology 2007, 8 : R146 doi:10.1186/gb-2007-8-7-r146 用STEM做了GO的显著性检验,P值,似乎大材小用 实战 STEM,总结如下: 1.用已经筛出来的差异基因做为输入,另外,用gene symbol来去除冗余(多个探针组对应同一蛋白,可以用UniRef);GO注释文件也以Gene symbol为ID(GO注释本来就是 注释 蛋白的,而非基因本身),但不可带有基因列表以外的Gene symbol。 2.可选STEM Cluster Method和K-means,设定Cluster数,进行GO Term富集分析。
个人分类: bioinformatics笔记|5106 次阅读|0 个评论
多词表达的定义
jhx0129 2009-3-3 15:14
multi-word expression,自2003年第一届aclMWEsworkshop来,几乎每年都有这样的一个workshop.关注焦点有identification,interpretation,disambiguation and applications。07年主要讨论抽取方法,08年则侧重评测,语料库的建设。 但中文的多次表达定义应如何?thinking...
个人分类: 未分类|4251 次阅读|3 个评论

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