There were small pieces of plastic in every sample.
VOA: special.2009.09.22
There's also another variance measure, which we use in the sample-- There's also another variance measure, which is for the sample.
还有另一个离散指标,我们用以考察样本,这是另一个离散指标,用于考察样本
There's another sample which is in Russia, part of the former Soviet Union, where there are samples that were stored.
另一个样本在俄罗斯,前苏联的一部分,那也有储存的样本
The guest list for the dinner provided a sample. Among those seated in the State Dining Room were the first two Muslims elected to the U.S.Congress Keith Ellison and Andre Carson.
VOA: standard.2009.09.02
We can define it in a couple of different ways depending on whether we're talking about sample mean or population mean.
我们有几种不同的方式去定义这个概念,取决于我们指的是,样本均值还是总体均值
So what researchers do is they hope to get enough people in a sample, where overall, you hope to be capturing normal intake.
所以研究者做的是,让尽可能多的人群进入样本,总体上你就可以得到正常的摄入量了
in both groups: the 250 here versus 250 here, which is significant sample size.
在这两组之间,样本规模相同的两组间。
And I say if you took a random sample of the Americans: "When you woke up in the middle of the night" and said: "What does the America stand for?"
我觉得如果给美国人做个抽样调查:,半夜醒来的时候“,被问到,美国人主张什么“
Do they get sample bottles coming in?
他们一开始就得到了样本瓶了吗?
One is in the U.S.at the Centers for Disease Control, where there is a sample of variola, which is kept, you know, frozen on ice in a heavily guarded facility.
一个在美国的疾病控制中心,那有一支天花病毒的样本,冰冻后置于重重保护之下
The danger is that it's being purified from patients that have a disease and so you want to make sure that there's not other diseases that are present in that sample at the same time.
危险在于,这是从带有疾病的病人,身上纯化出来,因此你想确保,在那个样本中不会同时,携带其它疾病
Also today, one of the teaching fellows will be sending out a sample concept sheet, although you may have already seen it from the website, but in addition to that, a series of instructions.
会有一位助教给大家发一篇论文模板,可能你们都在网站上看过了,不过除此之外,还有几项说明
Well let's talk about some mechanisms for using this and I'll start with a simple example of how one can detect a gene in a fluid, in a blood sample for example, where that gene is unknown.
我们来说说这项技术在实际应用中的机制,先从一个简单例子着手,如何在一个血样中,侦测是否存在某段基因序列,某段未知基因序列
Suppose that in a given year--and say this is minus five and this is plus five, this is minus five and this is plus five-- suppose that in the first year in our sample, the company Shiller, Inc. and the market both did 5%.
假设某一年...这里设为-5,这里+5,这是-5,这是+5,我们假设第一年中,希勒公司.和市场都获利5%
And the other thing you can do is take self reports like the ones you're doing, hopefully do enough of them, and a random enough sample of the population, that you can extrapolate from that sample to the whole population, and try to estimate what people are eating in that way.
还有其他可以做的,比如大家正在做的这种个体调查,希望能把它做的充分些,如果有充足的随机样本,就可以从样本推断出,整个总体,从而推断哪类人有这样的饮食习惯
Covariance is--we'll call it--now we have two random variables, so cov... I'll just talk about it in a sample term.
协方差是...我们有两个随机变量,x和y的协方差是,从样本的角度来说
You can also use PCR to identify specific genes that are present in a biological sample.
你也可以利用PCR技术去识别,一个生物样本中的某段特定基因
How could I identify in a chromosomal DNA sample whether the sickle gene is present?
那我该怎么确定某染色体DNA样本中,是否存在这种致病基因呢
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