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全部话题 - 话题: variation
1 2 3 4 5 6 7 8 9 10 下页 末页 (共10页)
t*d
发帖数: 1290
1
biological replicates 不一定比 technical replicates 更有意义。有些时候我们就
是希望知道technical replicates 的variation。
比如有人想做基因表达普,找差异表达的基因。一般现在第一个问题就是用microarray
还是 RNA-seq。如果目的是找差异表达基因,那么variation between technical
replicates 直接影响到 statistical power。如果同样两份细胞,通过 RNA-seq 流程
做出来(包括建库)的variation 比通过 microarray 流程做出来的variation 大,那
就是用microarray 做更好了。
那种之比较不同 lane 之间的 variation 对生物学家来说,没有什么现实指导意义。
另外,现在不少人认为 RNA-seq 成本已经将下来,和microarray 差不多了。可是这个
成本的下降是通过barcode multiplex 来实现的的。所以要比较 RNA-seq 和
microarray,最好能在同成本的条件下比。
M****i
发帖数: 58
2
If I am not missing somthing here, the sufficiency is not correct. For
example, choose the function sigma(y,t) to be the constant 1, then clearly
we have sigma(X,t) is deterministic (identically 1). But the corresponding
SDE becomes dX(t)=dW(t), so that the solution is X(t)=X(0)+W(t), whose
quadratic variation [X](t)=t, this is not a constant.
Maybe the question should be changed into:
If dX(t)=sigma(X(t),t)dW(t), then the following are equivalent:
1)the quadratic variation of X is a constant;
2... 阅读全帖
y*****w
发帖数: 1350
3
假设下面一个crossover design:
subject, random effect
renal site, fixed effect
drug treatment, fixed effect
SAS linear mixed model is as follows (no interaction effect of site and drug
):
proc mixed data=tmp cl;
class subject site drug;
model diff=site drug / ddfm=kr cl;
random subject;
run;
在crossover design的情况下,作linear mixed model后,如何计算inter-subject
and intra-subject coefficient of variation? 我看到下面这个blog提到intra-
subject coefficient of variation的计算:
http://onbiostatistics.blogspot.com/2014/03/in... 阅读全帖
d******u
发帖数: 178
4
我知道有一种算法,是求两个population的Mean相除之后相应的Coefficient of
Variation,是sqrt(CV1^2+CV2^2)。
现在有两个population,各自有Mean和Coefficient of Variation。现在要把这两个
population再合起来求Mean和Coefficient of Variation,请问如何计算?是简单的把
两个population pool起来还是有更高级的算法?
w****g
发帖数: 1143
5
照做了,结果是:
You cannot create a listing with variations in this category. If you
continue, the item specifics and variations you created will be deleted.
v*****r
发帖数: 2325
6
来自主题: Weightlifting版 - weight lifting variation (home version)
almost can find variation for all major exercise at gym (bench press and etc.)
bench press ----> push up
did a bit search, so many variation/difficulty levels
so many ways to use your body weight
one-arm, plyometrics push up, planche push up
for the most difficult, check this out, it'a quiet amazing do push up like
this:
http://www.youtube.com/watch?v=YvbLSgWMJec
and
http://www.youtube.com/watch?v=neN_uDYeQTA&feature=related
bruce lee finger push up
http://www.youtube.com/watch?v=T1I_
y****e
发帖数: 107
7
09/25/1932 - 10/04/1982
Glenn Gould: Variations on an Artist
http://archives.radio-canada.ca/IDD-0-18-309/personnalites/glenn_gould/
http://archives.cbc.ca/IDD-1-68-320/arts_entertainment/glenn_gould/
don't forget to click "10 Additional Clips about Glenn Gould: Variations on an Artist" to view more great audio/vedio archives about gould
u*********1
发帖数: 2518
8
如题。尤其是和disease相关的;研究strcutural variation/copy number variation在disease(尤其是
neurological disease)相关的牛人有哪些?
我知道的一个是UW的Evan Eichler;一个是BCM的James Lupski
不晓得还有什么牛人?
另外不晓得大家对这个方向(medical genomics)的前景如何看的
谢谢!
c******e
发帖数: 350
9
我几次读到报道,说用next generation sequencing 进行copy number variant的检测
技术还不成熟,因此,high throughput 的copy number variation检测还是用
microarray. 然而,报道的只是个结论,并没有说原因。
版上都是生物技术前沿的斗士们,一定有人会有一些经验和前瞻性的建议。所以,我特
来请教:
1) how microassay is better than next generation sequencing on copy number
detection.
2) If we have a sequencing assay for a targeted gene panel by next
generation sequencing, and want to further detect the copy number variation
on the same genes, what improvement is needed before using the NGS data for
co... 阅读全帖
G******2
发帖数: 579
10
【 以下文字转载自 Statistics 讨论区 】
发信人: Gigi2012 (Gigi), 信区: Statistics
标 题: 请问multi variate linear regression 选择risk factor 问题
发信站: BBS 未名空间站 (Thu Apr 9 23:51:47 2015, 美东)
问大牛一个basic 的问题。
在evaluate 一个 multi variate linear regression.
几个factor 同时被研究,individual correlation coefficient 都不大,只有0.3左
右,不知道为什么被选进了model.
然后每个factor 的coefficient 的R square 都小于0.5。
这个 model 是个好model 吗?
还是我看错地方了?
我的问题1。 不是应该选correlation coefficient 大的factor to enter the model?
还是p value 更重要?
R square 低于0.5 应该留在model 里吗?
选择factor ... 阅读全帖
l*y
发帖数: 21010
11
按照科学规定室内温度是不得高于72的 否则会有人生病
Owing to variations in humidity and likely clothing, recommendations for
summer and winter may vary; a suggested typical range for summer is 23 °C (
73 °F) to 25.5 °C (78 °F), with that for winter being 20 °C (68 °F) to
23.5 °C (74 °F).[2] Although by other considerations the maximum should be
below 24 °C (75 °F) – and for sick building syndrome avoidance, below 22
°C (72 °F).[2]
n****c
发帖数: 659
12
Amazon上明确说了Electronics里面不能列Variation,却偏偏有人这么列了。咋整的?
M***J
发帖数: 252
13
我可以把Variation列到Office Product里面,然后加一个Electronics的Category, 但
是产品点进去后,还是算Office Product,我需要点进去后是Electronics。我知道有
人这么做了。
请神医指点。
d**0
发帖数: 660
14
来自主题: ebiz版 - Amazon电子类如何列Variation?
seller客服说这个category不可以,但是我看到好多seller(非Amazon)都有
variation的。是不是有什么work around?能帮忙的包子伺候。
z**********3
发帖数: 11979
15

那你就多分别list吧
dailysteal卖nexus5还又variation又dailydeal
s*****t
发帖数: 19
16
前段时间申请macy's信用卡,结果被拒,理由是
SSN Variation between application and credit bureau,
我怀疑是前段时间本地小银行开始associate SSN到信用卡时,没有在First Name两个
字的拼音之间加空格,而我的SSN卡上是有空格的。当然也不是很确定。
请教高人两个问题:
(1)这种情况会影响去银行比如BOA开check帐户吗? 过两天就要去BOA,没车去一次
不容易,先来版上打听打听。
(2)该如何解决这个问题。 打Experian的电话,因为不知道report number,没法
dispute。。(Macy's给我寄的文件只有他家自己的Ref Number,不是Report Number.)
谢谢~!
y****e
发帖数: 107
17
来自主题: ClassicalMusic版 - Another Bach Variation: 2 Keyboards, 1 Pianist (ZZ)
video: http://video.on.nytimes.com/?fr_story=51447a22df4808817b10c4ec7f31af913673f701
http://www.nytimes.com/2007/07/17/arts/music/17tayl.html
Another Bach Variation: 2 Keyboards, 1 Pianist
KATONAH, N.Y., July 15 — For musical instruments, and a lot of other
industrial tools, the 18th century was an age of inventions. Restless
tinkerers looked for new shapes and functions, building and designing in a
spirit that we today have more or less turned over to electronic composers.
Mozart’s famous clar
s********y
发帖数: 979
18
来自主题: PhotoGear版 - 同一种相机的variation大不?
自己整S95和朋友的拍同样的场景感觉是有差别的。同样的设置。
这是因为同一种相机的variation造成的吗?
谢谢。
D*****r
发帖数: 6791
19
Stephen C Stearns在耶鲁的进化论与生态学课程的第6讲
http://www.youtube.com/watch?v=ZzkLYZCzHXk
The Origin and Maintenance of Genetic Variation
Overview:
Mutations are the origin of genetic diversity. Mutations introduce new
traits, while selection eliminates most of the reproductively unsuccessful
traits. Sexual recombination of alleles can also account for much of the
genetic diversity in sexual species. In some instances, population size can
affect diversity and rates of evolution and fixation, but in other ca... 阅读全帖
p*****r
发帖数: 2
20
那我就不提TCP了,就说sequence巴:
I'm calculating the QoS-delay variation(jitter):
I think for a transport Protocol for Real-Time Applications, like
audio/video, the sequence of data should be considered when
you calculate jitter. for example:
sender sends data out with sequence 0, 1, ...9.
Receiver A may receive the data with sequence 0,1,...9 while
Receiver B may receive the data with sequence 1,...9, 0.
Suppose the arrival interval time of the data is the same,
then, without considering the sequence, th
x****i
发帖数: 3
21
不是生物专业,想了解一些关于copy number variation and gene expression data
processing 的基本的知识,不知大家有没有知道的。先谢谢了!
u*********1
发帖数: 2518
22
来自主题: Biology版 - About copy number variation
Anyone in the field of genome structural variation?
Do people mainly use NGS than microarray for such study nowadays? (But I see
still someone uses microarray...Can sb. give a comparison?)
Btw, I'm a beginner in genomics, do we have some bioinformatics tutorial
DIRECTLY for NGS study?
Just confused at beginner!
Thanks!
d*******e
发帖数: 1649
23
来自主题: Biology版 - About copy number variation
现在的NGS对copy number variation的处理还有一些问题,整个方法还没有成型。传统
上array CGH还是可以的,但你一定要看NGS的东西的话自己找paper看吧,或者找做这
个的人直接问。

see
l*****a
发帖数: 1431
24
来自主题: Biology版 - About copy number variation
Genome structural variation discovery and genotyping. Nature Review Genetics
, May 2011
t*d
发帖数: 1290
25
看了几篇文献,没搞懂他们的technical replicates 是怎么定义的。
引用比较多的那篇“Marioni JC, Mason CE, Mane SM, Stephens M, Gilad Y: RNA-
seq: an assessment of technical reproducibility and comparison with gene
expression arrays. Genome Res 2008, 18:1509-1517.”他们的technical
replicates 是把构建好的短片段放在不同lanes,然后比较不同lane 出来的读数。
因为RNA-seq 很大一部分工作在如何构建最后测序的短片段库,而且这个建库的过程相
当繁琐,可能会带来很多的variation。我觉得更严格的technical replicates 应该从
RNA 抽提开始。比如,一份细胞分两管,分别进行建库和测序,然后再比较读数,看看
varation 有多大。
那位同学能不能推荐几篇比较这种更严格的 technical replicates 的文章?多谢了先!
n***w
发帖数: 2405
26
乍一看还以为是choroidal neovascularization.
心想,这咋和genome structural variation联系上。。。lol
m****c
发帖数: 244
27
+1: matt hurles @ sanger

variation在disease(尤其是
a***e
发帖数: 1010
28
来自主题: Biology版 - copy number variation
如果想用deep sequencing 检测 copy number variation,20 倍的覆盖度够吗?
谢谢
r**********e
发帖数: 587
29
来自主题: Biology版 - copy number variation
还有,
如果是deep seq,那么可以做各种各样的structural variation
CNV只是SV的一种而已
r**********e
发帖数: 587
30
看到一堆whole-genome sequencing寻找structural variation的文章,但大部分的都
是methodology;然后1000genome测了几千个正常人的SV
但我搜了半天都几乎没看到有什么具体的disease(貌似有几个cancer tumor的),说
某个病通过WGS寻找到新的SV的。(已知SV然后验证的不算)
或许是我搜索能力太差?
谢谢
a***n
发帖数: 3633
31
一个函数,是由初等函数+四则运算构成的,但是有的常数是以符号的形式给出的。
请问如何计算它的total variation?
l*********o
发帖数: 88
32
给一个随机过程 X(t), 随机微分方程:
dS = sigma(X,t) dW.
证明:the quadratic variation of X up to T 是一个常数的必要且充分条件是
sigma(X,t) = sigma(t)。也就是说sigma不是随机的。
谢谢。
c**********e
发帖数: 2007
33
What is the quadratic variation of X up to T? Could you clarify it?
是一个常数 with respect to T or with respect to randomization?
l******i
发帖数: 1404
34
Proof:
dX(t) = sigma(X(t),t)*dW(t)
With quadratic variation of X(t)=M(X)
=integration from 0 to t of (sigma(X(s),s)^2)*ds
which is a distribution if sigma is stochastic.
So M(X) is constant if and only if Var(M(X))=0.
Var(M(X))=0 iff sigma is a deterministic function of t.
x***c
发帖数: 17
35
The coefficient of variation (abbreviated CV) is a way to quantify scatter.
It is defined as the standard deviation of a group of values divided by
their mean.
In terms of CV of the incidence rate, can anybody help me with the
explaination? what is the formula of that?
In order to explain it to medical doctors, is there a good way to explain?
Thanks a lot!
G******2
发帖数: 579
36
问大牛一个basic 的问题。
在evaluate 一个 multi variate linear regression.
几个factor 同时被研究,individual correlation coefficient 都不大,只有0.3左
右,不知道为什么被选进了model.
然后每个factor 的coefficient 的R square 都小于0.5。
这个 model 是个好model 吗?
还是我看错地方了?
我的问题1。 不是应该选correlation coefficient 大的factor to enter the model?
还是p value 更重要?
R square 低于0.5 应该留在model 里吗?
选择factor 的原则是什么?
我只有一点biostats 背景。不是很清楚这个问题是我自己不懂呢还是他们错了。请大
家解释一下。谢谢。
G******2
发帖数: 579
37
【 以下文字转载自 Quant 讨论区 】
发信人: Gigi2012 (Gigi), 信区: Quant
标 题: Re: 请问multi variate linear regression 选择risk factor 问题 (
发信站: BBS 未名空间站 (Fri Apr 10 01:32:27 2015, 美东)
他们没有report p value 和t statistics .我还在想是我不懂的原因,一般来说我先
看p value. 不过我可以要求report
R square 看起来是model 的。
给我的sad code 打不丶开。我家电脑没有sas.
说是用的Bayesian schawz criteria selection. 跟我平常用的stepwise 和backwards
selection 不一样。不懂呀。
最小的SBC 和最大的RSQ的variable 被淘汰了,说intuitive judgement 不make
sense 是个dummy variable
用了两个variable 说 SBC 最小值,然后rsq 也最大。然后multivara... 阅读全帖
G******2
发帖数: 579
38
发信人: Gigi2012 (Gigi), 信区: Quant
标 题: Re: 请问multi variate linear regression 选择risk factor 问题 (
发信站: BBS 未名空间站 (Fri Apr 10 01:50:02 2015, 美东)
继续问,怎么要求report 有无colineality 。我觉得这些tested variable 长得都太
相似了。
k********k
发帖数: 5617
39
来自主题: ClassicalMusic版 - 芭蕾舞課鋼琴伴奏 1,2,3
Ballet music pieces transcripted for Piano - 1/3
Published on Sep 18, 2012
In this videos you can find some of ballet world's most famous music pieces.
These melodies are often used for ballet classes. The pianist is Igor
Zapravadin.
This is the list of the pieces who you can listen in this first video:
-Léo Delibes - Sylvia (Pizzicato Variation from 3rd Act) -- 0:00
-Aleksandr Glazunov - Raymonda (Pizzicato Variation from 1st Act) -- 1:25
-Charles Gounod - Faust (Ballet Music excerpt) -- 2:52
-... 阅读全帖
k********k
发帖数: 5617
40
Ballet music pieces transcripted for Piano - 1/3
Published on Sep 18, 2012
In this videos you can find some of ballet world's most famous music pieces.
These melodies are often used for ballet classes. The pianist is Igor
Zapravadin.
This is the list of the pieces who you can listen in this first video:
-Léo Delibes - Sylvia (Pizzicato Variation from 3rd Act) -- 0:00
-Aleksandr Glazunov - Raymonda (Pizzicato Variation from 1st Act) -- 1:25
-Charles Gounod - Faust (Ballet Music excerpt) -- 2:52
-... 阅读全帖
m****i
发帖数: 1076
41
来自主题: MusicPlayer版 - Blues Lesson (1)[转载]
Lesson: 1
Title: BASIC BLUES
Level: Beginner (+Intermediate)
Style: 12-bar Blues, theory
Instructor: Olav Torvund
[Editor's note - Olav is sending us this lesson for Norway. Some of
the musical terms he is using are spelled slightly differently from the
way they are spelled in the U.S. (they are probably closer to the Latin
than English allows) Wherever these spelling differences occur, I
have added the U.S. English equivalent initially, but have left them
in their original spelling thro... 阅读全帖
f**d
发帖数: 768
42
来自主题: Neuroscience版 - eBook: From computer to brain
这是一本计算神经科学的优秀著作,全文拷贝这里(图和公式缺),有兴趣的同学可以
阅读
如需要,我可以分享PDF文件(--仅供个人学习,无商业用途)
From Computer to Brain
William W. Lytton
From Computer to Brain
Foundations of Computational Neuroscience
Springer
William W. Lytton, M.D.
Associate Professor, State University of New York, Downstato, Brooklyn, NY
Visiting Associate Professor, University of Wisconsin, Madison
Visiting Associate Professor, Polytechnic University, Brooklyn, NY
Staff Neurologist., Kings County Hospital, Brooklyn, NY
In From Computer to Brain: ... 阅读全帖
a*******u
发帖数: 6324
43
嗐!轩哥,那不就是叫做Vibrato嘛。
就抖啊,就震啊,就一个词根啊。
http://en.wikipedia.org/wiki/Vibrato
http://zh.wikipedia.org/wiki/%E9%A1%AB%E9%9F%B3_(%E9%9F%B3%E6%A
颤音 (音乐)
维基百科,自由的百科全书
颤音是一种乐器技巧。
Vibrato
From Wikipedia, the free encyclopedia
Vibrato is a musical effect consisting of a regular, pulsating change of
pitch. It is used to add expression to vocal and instrumental music. Vibrato
is typically characterised in terms of two factors: the amount of pitch
variation ("extent of vibrato") and the speed with which the p... 阅读全帖
j*p
发帖数: 411
44
本人在wet lab里面做纯数据分析,for NGS data analysis, 简单介绍一些自己接触过
,并且觉得挺有用的工具,说的有点杂,权作抛砖引玉,还请不吝赐教。
Next-Gen sequencing(NGS)和现在正在发展的3rd-gen sequencing将会在生物学研究中
被越来越广泛应用。不管你信不信,反正我信了。一是基于实验成本的降低($1k
whole-genome sequencing is coming),越来越多的实验室可以操作;二是可以提供
相对low throughput experiment多的多的数据和信息,可以看到很多从前看不到的东
西;三是sequencer本身对测序的准确性正在逐渐提高,所以实验固有错误率降低;四
是各种算法的成熟应用,这使得很多由于实验产生的误差在出数据后通过对数据的分析
得以过滤。按照library preparation来分,NGS主要有DNA-seq和RNA-seq
DNA-seq is usually used as ChIP-seq to study transcription factor(TF)-DNA
bi... 阅读全帖
j*p
发帖数: 411
45
本人在wet lab里面做纯数据分析,for NGS data analysis, 简单介绍一些自己接触过
,并且觉得挺有用的工具,说的有点杂,权作抛砖引玉,还请不吝赐教。
Next-Gen sequencing(NGS)和现在正在发展的3rd-gen sequencing将会在生物学研究中
被越来越广泛应用。不管你信不信,反正我信了。一是基于实验成本的降低($1k
whole-genome sequencing is coming),越来越多的实验室可以操作;二是可以提供
相对low throughput experiment多的多的数据和信息,可以看到很多从前看不到的东
西;三是sequencer本身对测序的准确性正在逐渐提高,所以实验固有错误率降低;四
是各种算法的成熟应用,这使得很多由于实验产生的误差在出数据后通过对数据的分析
得以过滤。按照library preparation来分,NGS主要有DNA-seq和RNA-seq
DNA-seq is usually used as ChIP-seq to study transcription factor(TF)-DNA
bi... 阅读全帖
l**d
发帖数: 472
46
Why Do Women Live Longer Than Men?
http://www.time.com/time/printout/0,8816,1827162,00.html
Across the industrialized world, women still live 5 to 10 years longer than
men. Among people over 100 years old, 85% are women, according to Tom Perls,
founder of the New England Centenarian Study at Boston University and
creator of the website LivingTo100.com. Time.com asks him why.
Q: Why do women live longer than men?
A: One important reason is the big delay — and advantage — women have over
men in te... 阅读全帖
t******l
发帖数: 10908
47
来自主题: Go版 - 猜测一下阿发狗的原理
具体算法不知道。但所有的人类下棋这种快速而简单的思维,都是基于心理学上的
schema,也就是 prior knowledge。在这些 schema 基础上做 variation。
跟深蓝不同的是,现代计算机的发展,阿尔法狗可以把全世界所有已知的下过的棋局
都装在机器里。这样阿尔法狗可以计算出基本上人类在给定时间里可以想出来的所有
根据过去 schema 的 variation,以及各种 variation 的概率。
这样在机器训练的时候,阿尔法狗可以自己跟自己的克隆下,创建更多的 variation,
产生更多的 schema。
如果不在所有的 schema 的 variation 里,多半是无理棋。那阿尔法狗硬算也
不会吃亏。
外加跟石头下的时候,石头过去下的棋的所有 schema 都存在。而且比赛前阿尔法狗
还可以克隆一个石头风格阿尔法狗,事前把石头所有大概率的 schema variation
都跑一遍。
等等等等。
a****s
发帖数: 11
48
肖邦全集Chopin Complete Edition 17CD
Executan: Krystian Zimerman,Claudio Arrau,Stefan Askenase,Anatol Ugorski,
Maurizio Pollini,Jean-Marc Luisada,Lilya Zilberstein,Daniel Barenboim,Martha
Argerich,Stanislav Bunin,Mikhail Pletnev,Heidi Bung,Kurt Bauer,Mstislav
Rostropovich,Malcolm Martineau,Elzbieta Szmytka,Vladimir Ashkenazy,Lambert
Orkis,Anner Bylsma,Kyrill Kondrashin,Carlo Maria Giulini,Willem van Otterloo
Conductor: Kyrill Kondrashin、 Carlo Maria Giulini、 Willem van Otterloo
Commander commander... 阅读全帖
E*****m
发帖数: 25615
49
要反進化論好歹要反人家相信的東西,自己樹立個稻草人打得不亦樂乎
做什麼?
拜託讀點書,讓別人有理由尊重你。
http://www.pbs.org/wgbh/evolution/library/faq/cat01.html
7. Is evolution a random process?
Evolution is not a random process. The genetic variation on which
natural selection acts may occur randomly, but natural selection itself is
not random at all. The survival and reproductive success of an individual is
directly related to the ways its inherited traits function in the context
of its local environment. Whether or not an individu... 阅读全帖
z**********g
发帖数: 16
50
bout “Repulsive particle” hypothesis
Zhuang Yilong
Shanghai Institute of Science and Technology Managemen
Jiading 201800
“Repulsive particle” hypothesis is a new theory of material
action. Contrary to Newton law of universal gravitation, which explains why
an apple on the three falls to the ground, it can be called law of universal
repulsion which explains why an apple grows on the tree. It regards a plank
quantum as a material particle, which is a epulsive particle”
counter... 阅读全帖
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