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Minerals like calcium and phosphate keep your bones tough and rigid,
像钙和磷酸盐这样的矿物质使你的骨骼保持坚硬，
so your limbs can be attached properly, and your body's not just a squishy mess of tissue.
这样你的四肢才能正常地活动,你的躯体，不至于成为一堆软乎乎的组织。
But sometimes minerals can build up where they're not supposed to.
但有时矿物质能够在意料之外的地方起作用。
In fact, after a heart attack, some of your heart tissue could effectively turn into bone.
事实上，心脏病发作后,你的部分心肌组织能有效的转化为骨。
This might sound kind of like a mutant superpower, but it's actually really dangerous,
这可能听起来像是一种超强突变，但实际上这相当危险
and has perplexed scientists for a while.
并且曾经困扰了科学家一段时间。
But a new study published in the journal Cell Stem Cell suggests that these bony calcium deposits
但发表在Cell Stem Cell杂志上的最新研究表明，这些骨钙沉积
are just an unfortunate byproduct of the heart trying to heal itself.
仅仅是心脏试图治愈自身的不良副产物。
It's no surprise that heart tissue and bone tissue have really different jobs.
心肌组织和骨组织具有完全不同的功能，这并不奇怪。
Heart muscle has to be flexible and beat in a rhythm to keep your blood circulating.
心肌必须灵活，以一定的节律跳动从而保持血液循环。
Your heartbeat is controlled by electrical signals that spread through the muscle cells
你的心跳受到心肌细胞中传递的电信号的控制
that make up different heart chambers.
这些心肌细胞构成不同的心脏室。
So when heart tissue turns all stiff and mineralized, it can't conduct those signals as well,
因此当心脏组织变得僵硬和矿化时，它也就不能执行这些电信号了，
and your heart can't keep that smooth, steady beat – a condition called heart block.
心脏不能保持平稳的心跳，这种情况叫做心肌梗死。
And there's currently no medical treatment to break down these calcium deposits if they form.
并且这些钙沉积物一旦形成目前没有医疗手段能够分解它们。
This bone-like tissue can form after a heart attack, where blood flow gets blocked
这些类骨组织会在心脏病发作后形成，它们会阻碍血液流动
so the cells get deprived of oxygen and start to die.
因此细胞会缺氧并开始坏死。
We know that the heart can kind of repair itself when it gets injured.
我们知道心脏受伤时会自我修复。
In fact, in an earlier paper, this team of researchers showed
事实上，在更早的文献中这个团队的研究显示
that some heart cells can even switch jobs to try and patch things up.
一些心脏细胞甚至能够转而承担修补工作。
See, usually, all mature cells take on a specific function and stay that way forever.
通常，所有成熟细胞都有其特定功能并且一直保持这样。
But rarely, with the right signal from the body, certain cells can change forms.
但罕见地，在接收到来自身体的正确信号时某些细胞可以改变形态。
In this case, the turncoats are called cardiac fibroblasts, a type of connective cell,
这种情况下，这些“变节者”被称为心脏成纤维细胞，它是一种连接细胞
which can become blood vessel cells after an injury.
能够在机体受伤之后成为血管细胞。
And in the study published this week, these researchers found that cardiac fibroblasts
在本周发表的研究中，这些研究者发现心脏成纤维细胞
can also become cells that act just like osteoblasts,
也能够表现成骨细胞的特性成骨细胞，
the cells responsible for depositing minerals in your bones.
负责在骨骼中储存矿物质。
To figure this out, they took heart fibroblasts from mice with calcified hearts
为了弄清楚，他们从心脏钙化的老鼠身上获取成纤维细胞
and put them in healthy mice hearts.
然后放到正常老鼠心脏里。
They observed that these osteoblast-like cells started depositing calcium,
他们观察到这些类成骨细胞开始储存钙质，
and mineralizing other cells.
并矿化其他细胞。
They're still not completely sure why heart cells would start spewing out minerals,
他们仍然不能完全确定心脏细胞为何会大量释放矿物质
but it's probably an accident.
但那可能是一个意外。
Maybe the fibroblasts are trying to switch jobs one way to be helpful, they mess up,
可能成纤维细胞试图通过转变功能来变的更有用，但它们搞砸了
and go down a different developmental path.
走上了一条不同的发展道路。
The researchers hope that by understanding how heart cells can make this mistake,
研究者希望通过理解心脏细胞的犯错机制
they'll be able to develop drugs that block this sort of calcium buildup in patients.
他们能够开发出阻断病人体内这种钙沉积的药物。
Lots of scientists are researching really small things
许多科学家在研究很不起眼但是可能在人体中
that can go wrong in human bodies, but plenty are also looking at planet-wide issues.
出错的过程，但是还有很多科学家关注的是全球的问题。
For example, some fish populations are plummeting because of things like commercial fishing and climate change.
比如，一些鱼类种群数量由于商业捕鱼和气候变化的原因而骤降。
And it's not like you can just stick your head underwater and count them to check on the damage.
并不是你把头伸到水下数数就能核实危害的程度。
So, in a new paper, a team of Danish researchers think a soda bottle full of seawater
因此，在一项新研究中一个丹麦的研究团队认为一苏打水瓶的海水
might have the power to tell us how many and what kinds of fish are in the ocean.
可能能够告诉我们海里有多少鱼、是什么种类的。
One strategy to keep tabs on fish populations is trawling,
监视鱼类种群数量的一种方法是拖网作业，
or dragging a big net across the seafloor and seeing what you scoop up.
即在海底撒一张大网看看能捞上来什么。
But it has its problems: only part of the ocean floor is flat enough to drag a net across,
但是这种方法存在问题：不是所有的海底都平坦到适合撒网，
some bigger animals can easily avoid the nets, it's pretty invasive, and it's not all that fast.
一些大型的动物能轻易地避开网，这种方法太具侵略性并且没有那么快。
Researchers can also ask commercial fishing companies how much they've caught,
研究者也可以了解渔业公司捕到的鱼数量，
and try to estimate fish populations that way.
以此来推断鱼类种群的数量。
But this is the twenty-first century, and we have cool sciencey toys now,
但现在是二十一世纪了如今我们有更酷的科学玩具，
like quick, cheap, accurate DNA sequencing.
比如快速、廉价、精确的DNA测序。
Fish shed DNA in the water all the time,
鱼类在水中会一直脱落DNA，
just like we humans leave bits and pieces of ourselves wherever we go.
就像我们人类到哪都会留下我们自身的皮屑毛发一样。
So instead of scooping up the fish, a team of Danish researchers figured
所以一个丹麦的研究者团队认为他们可以
they could just scoop up a bunch of environmental DNA, or eDNA, from the water,
从水中取得一些环境DNA或eDNA来取代捕鱼，
and match it to known tissue samples and sequences.
然后将得到的DNA和已有的组织样本和序列进行比对。
They ran a traditional trawling study side-by-side with this eDNA study,
他们同时进行了拖网作业研究和这个eDNA研究，
pulling up two liters of water – a soda-bottle sized amount – everywhere they dropped a net.
在每个撒网的地方取两升水样--一瓶苏打水的量。
And, for the most part, the eDNA was able to tell them what was in that part of the ocean.
在大多数情况下eDNA能够告诉他们在那片海里有哪些动物。
eDNA sequencing did miss some rare fish that trawling caught,
eDNA测序确实漏掉了一些拖网作业捕到的稀有鱼，
suggesting that two liters of water just didn't have enough of their DNA in it.
说明两升水里这些鱼DNA的含量不够多。
Plus, the scientists are still figuring out how the amount of DNA can be used
另外，科学家仍然在研究如何用DNA的含量
to estimate the actual number of fish in the water.
估计海里鱼的数量。
But in the case of one species, the Greenland shark,
但对其中一个物种格陵兰鲨鱼来说，
the eDNA method may actually have done a better job than trawling.
eDNA方法实际上已经比拖网作业得到了更好的结果。
The researchers say that Greenland sharks are big enough to avoid trawling nets.
研究者说格陵兰鲨鱼大到能够避开拖网。
But this issue doesn't apply to their DNA, so it might provide a better estimate of their numbers.
但这个问题不适用于它们的DNA，所以eDNA方法可能提供了更好的方法估计它们的数量。
Mostly, because eDNA sequencing is much less invasive than trawling,
主要是因为eDNA测序对环境的破坏性比拖网作业小得多，
these scientists think it's a promising option for future fish studies, even though it still needs some refining.
这些科学家认为这是未来鱼类研究一个很有前途的方向，即使它仍需改善
Thanks for watching this episode of SciShow News, brought to you by our President of Space,
谢谢观看由我们的President of Space带来的本期科学秀,
you guessed it…. SR Foxley! Thanks SR!
你一定猜到了。SR Foxley！谢谢SR！
And if you want to help support this show, you can go to patreon.com/scishow.
如果你想赞助本节目,请访问patreon.com/scishow。
And don't forget to go to youtube.com/scishow and subscribe!
别忘了登录youtube.com/scishow订阅我们！
