A Great Discovery, 25 Years in the Understanding
Carol W. Greider is the Daniel Nathans Professor & Director of Molecular Biology & Genetics at Johns Hopkins University. Her research on telomerase (an enzyme she helped discover) and telomere function won her a 2009 Nobel Prize in Medicine. Prior to joining the Johns Hopkins faculty, she obtained a Ph.D. in Molecular Biology from the University of California, Berkeley, in 1997, and was a faculty member at the Cold Spring Harbor Laboratory. She is a member of the National Academy of Sciences and a recipient of the 1998 Gairdner Foundation International Award.
Question: What was the telomere problem and how did you solve it?
Carol Greider: Well, at the basic level it has to do with how cells can divide many times. What was known in the late 1970s was that when you copy a chromosome, the way that the mechanism copies a chromosome, every time a cell divides, the very, very end bit can't be completely copied. And so then the idea was that the chromosomes, or the telomeres, which are the chromosome ends, would get shorter and shorter and shorter every time a cell divides. And that can't happen indefinitely; there has to be some mechanism which will balance that shortening. And that's where the discovery of telomerase comes in. And so for any cell that has to divide many times, they need to have a way to balance so that there's some shortening and some lengthening and some shortening and some lengthening, and an equilibrium is then maintained so that the cells can then go on and divide.
Question: What was your methodology in making the discovery?
Carol Greider: We were very interested in, as I said, telomeres and chromosomes and how they functioned. And so we really went to the source where there are a lot of telomeres. And this was something that Liz Blackburn had done a number of years before, when she had discovered the DNA sequence that telomeres is made up of. And it's a very, very simple repeated DNA sequence that is sort of a monotonous many, many, many repeats. And she had discovered the telomere DNA sequence in this organism called tetrahymena; it's a single-celled organism very much like the paramecium that high school students might go out to a pond and bring back some pond water and see the paramecium floating around. The thing about tetrahymena is that they have 40,000 chromosomes. And so it was a very good source to be able to understand what the ends of the chromosomes were. So when we set out to ask, is there an enzyme that can lengthen the chromosomes to balance the shortening, we went again to tetrahymena, and you can just get these organisms and grow them up in the laboratory. So we would grow up a large batch of the cells, and then you spin the cells down in a centrifuge so you make a very compact collection of them, and then break them open to get the insides of the cells out so that you can understand what is going on inside the cells.
Question: Was the 25-year delay in recognizing your discovery unusual?
Carol Greider: I think it's more that the discovery was made in 1984, and it was clear that it was important at the time. But it was important as a very basic cellular mechanism. And there wasn't a lot of questions; I didn't get a lot of people doubting what the conclusion was. But instead, it wasn't clear what the implications were. In the 25 years that have intervened, my lab and Liz's lab and a number of other labs throughout the world have contributed all kinds of different ideas from different avenues that have made it very clear now what the medical implications are. And so there are clear medical implications that we didn't know at all at the beginning. We were just solving a puzzle because we were curious about how cells worked, although we knew that it was a fundamental mechanism. We weren't just doing experiments just to find out anything, but rather to really understand how a cell works. And the 25 years in between really has allowed it to be clear what the implications of that discovery were.
Recorded November 10th, 2009
Interviewed by Austin Allen
What is telomerase? How was it identified? And why did the discovery take 25 years to win the Nobel? Biologist Carol Greider shares the inside story.
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What is human dignity? Here's a primer, told through 200 years of great essays, lectures, and novels.
- Human dignity means that each of our lives have an unimpeachable value simply because we are human, and therefore we are deserving of a baseline level of respect.
- That baseline requires more than the absence of violence, discrimination, and authoritarianism. It means giving individuals the freedom to pursue their own happiness and purpose.
- We look at incredible writings from the last 200 years that illustrate the push for human dignity in regards to slavery, equality, communism, free speech and education.
The inherent worth of all human beings<p>Human dignity is the inherent worth of each individual human being. Recognizing human dignity means respecting human beings' special value—value that sets us apart from other animals; value that is intrinsic and cannot be lost.</p> <p>Liberalism—the broad political philosophy that organizes society around liberty, justice, and equality—is rooted in the idea of human dignity. Liberalism assumes each of our lives, plans, and preferences have some unimpeachable value, not because of any objective evaluation or contribution to a greater good, but simply because they belong to a human being. We are human, and therefore deserving of a baseline level of respect. </p> <p>Because so many of us take human dignity for granted—just a fact of our humanness—it's usually only when someone's dignity is ignored or violated that we feel compelled to talk about it. </p> <p>But human dignity means more than the absence of violence, discrimination, and authoritarianism. It means giving individuals the freedom to pursue their own happiness and purpose—a freedom that can be hampered by restrictive social institutions or the tyranny of the majority. The liberal ideal of the good society is not just peaceful but also pluralistic: It is a society in which we respect others' right to think and live differently than we do.</p>
From the 19th century to today<p>With <a href="https://books.google.com/ngrams/graph?year_start=1800&year_end=2019&content=human+dignity&corpus=26&smoothing=3&direct_url=t1%3B%2Chuman%20dignity%3B%2Cc0" target="_blank" rel="noopener noreferrer">Google Books Ngram Viewer</a>, we can chart mentions of human dignity from 1800-2019.</p><img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNDg0ODU0My9vcmlnaW4ucG5nIiwiZXhwaXJlc19hdCI6MTY1MTUwMzE4MX0.bu0D_0uQuyNLyJjfRESNhu7twkJ5nxu8pQtfa1w3hZs/img.png?width=980" id="7ef38" class="rm-shortcode" data-rm-shortcode-id="9974c7bef3812fcb36858f325889e3c6" data-rm-shortcode-name="rebelmouse-image" />
American novelist, writer, playwright, poet, essayist and civil rights activist James Baldwin at his home in Saint-Paul-de-Vence, southern France, on November 6, 1979.
Credit: Ralph Gatti/AFP via Getty Images
The future of dignity<p>Around the world, people are still working toward the full and equal recognition of human dignity. Every year, new speeches and writings help us understand what dignity is—not only what it looks like when dignity is violated but also what it looks like when dignity is honored. In his posthumous essay, Congressman Lewis wrote, "When historians pick up their pens to write the story of the 21st century, let them say that it was your generation who laid down the heavy burdens of hate at last and that peace finally triumphed over violence, aggression and war."</p> <p>The more we talk about human dignity, the better we understand it. And the sooner we can make progress toward a shared vision of peace, freedom, and mutual respect for all. </p>
Is Bitcoin akin to 'digital gold'?
- In October, PayPal announced that it would begin allowing users to buy, sell, and hold cryptocurrencies.
- Other major fintech companies—Square, Fidelity, SoFi—have also recently begun investing heavily in cryptocurrencies.
- While prices are volatile, many investors believe cryptocurrencies are a relatively safe bet because blockchain technology will prove itself over the long term.
Presentation slide from Sanja Kon's presentation on the evolution of money at 2020 Web Summit
Credit: Sanja Kon<p>The move came shortly after the payments company Square invested $50 million into Bitcoin, and after Fidelity announced that it was opening a Bitcoin fund into which qualified purchasers could invest <a href="https://www.bloomberg.com/news/articles/2020-08-26/fidelity-launches-inaugural-bitcoin-fund-for-wealthy-investors" target="_blank">(minimum investment: $100,000)</a>. Together, this institutional backing might have something to do with Bitcoin's recent surge back to near its 2017 price peak of $19,783. (Bitcoin is listed at 19,384.30 as of Dec. 3.)<br></p>
Presentation slide from Sanja Kon's presentation on the evolution of money at 2020 Web Summit
Credit: Sanja Kon<p>But more importantly, it suggests cryptocurrencies might soon have the opportunity to prove themselves in real-world use cases. After all, skeptics have long doubted the ability of cryptocurrencies to go mainstream as a form of everyday payment. But people seem increasingly comfortable with digital payment systems.</p><p style="margin-left: 20px;">"The entire world is going to come into digital first," Schulman said at Web Summit, adding that PayPal's services already go hand-in-hand with cryptocurrencies. "As we thought about it, digital wallets are a natural complement to digital currencies. We've got over 360 million digital wallets and we need to embrace cryptocurrencies."</p><p>Sanja Kon, vice president of global partnerships at the cryptocurrency payments processor company UTRUST, also spoke at Web Summit about the increasing adoption of digital payments:</p><p style="margin-left: 20px;">"Physical cash is becoming more and more obsolete. And the next step in the evolution is digital currency."</p><p>Kon noted some of the inherent advantages of cryptocurrencies, namely ownership. </p><p style="margin-left: 20px;">"For many people, this is really the main benefit of cryptocurrency: Users owning cryptocurrencies are able to control how they spend their money without dealing with any intermediary authority like a bank or a government, for example," Kon said, adding that there are no bank fees associated with cryptocurrencies, and that international transaction fees are significantly lower than wire transfers of fiat currency.</p><p>Kon said cryptocurrencies have unique growth opportunities in areas where people aren't integrated into modern banking systems:</p><p style="margin-left: 20px;">"With cryptocurrencies and blockchain, with the use of just a smartphone and access to internet, Bitcoin and cryptocurrencies can be available to populations of people and users without access to the traditional banking system."</p>
Bitcoin as 'digital gold'<p>Still, it could take years for people to start using cryptocurrencies for everyday purchases on a large scale. Despite this, many cryptocurrency advocates see digital currencies, particularly Bitcoin, as a way to store value—digital gold, essentially.</p><p style="margin-left: 20px;">"I don't think Bitcoin is going to be used as a transactional currency anytime in the next five years," billionaire investor Mike Novogratz recently told <a href="https://www.bloomberg.com/news/articles/2020-10-23/novogratz-says-bitcoin-is-digital-gold-not-a-currency-for-now?srnd=markets-vp" target="_blank">Bloomberg</a>. "Bitcoin is being used as a store of value. [...] "Bitcoin as a gold, as digital gold, is just going to keep going higher. More and more people are going to want it as some portion of their portfolio."</p><p>There are obvious parallels between gold and Bitcoin: Both are mined, do not degrade over time, are finite in supply, and aren't directly tied to the value of fiat currency, making them <a href="https://www.reuters.com/article/us-gold-inflation/gold-as-an-inflation-hedge-well-sort-of-idUSKCN1GD516" target="_blank" rel="noopener noreferrer">relatively invulnerable to inflation</a>. The obvious objection is that the price of Bitcoin, and cryptocurrencies in general, is far more volatile than gold.</p><p>But for investors who believe the inherent value of cryptocurrency technology will prove itself over the long term, these price fluctuations are just bumps on the long road to the future of currency. </p><p style="margin-left: 20px;">"It's no longer a debate if crypto is a thing, if Bitcoin is an asset, if the blockchain is going to be part of the financial infrastructure," Novogratz said. "It's not if, it's when, and so every single company has to have a plan now."</p>
Singapore has approved the sale of a lab-grown meat product in an effort to secure its food supplies against disease and climate change.
Approve for your dining pleasure<span style="display:block;position:relative;padding-top:56.25%;" class="rm-shortcode" data-rm-shortcode-id="dd3f57f8baf14e654812d30a309d1f17"><iframe type="lazy-iframe" data-runner-src="https://www.youtube.com/embed/307gysA18_E?rel=0" width="100%" height="auto" frameborder="0" scrolling="no" style="position:absolute;top:0;left:0;width:100%;height:100%;"></iframe></span><p><a href="https://www.ju.st/en-us" target="_blank" rel="noopener noreferrer">Eat Just</a>, a company that produces animal-alternative food products, announced the news earlier this week. In what the company is calling a world first, Singapore has given it permission for a small-scale commercial launch of their GOOD Meat brand product line. For the initial run, the cultured chicken meat will be sold as an ingredient in "chicken bites."</p><p>"Singapore has long been a leader in innovation of all kinds, from information technology to biologics to now leading the world in building a healthier, safer food system. I'm sure that our regulatory approval for cultured meat will be the first of many in Singapore and in countries around the globe," Josh Tetrick, co-founder and CEO of Eat Just, <a href="https://www.businesswire.com/news/home/20201201006251/en/Eat-Just-Granted-World%E2%80%99s-First-Regulatory-Approval-for-Cultured-Meat" target="_blank" rel="noopener noreferrer">said in a release</a>.</p><p>According to the release, Eat Just underwent an extensive safety review by the Singapore Food Agency. It provided officials "details on the purity, identity and stability of chicken cells during the manufacturing process, as well as a detailed description of the manufacturing process which demonstrated that harvested cultured chicken met quality controls and a rigorous food safety monitoring system." It also demonstrated the consistency of its production by running more than 20 cycles in its 1,200-liter bioreactors.</p><p>While Eat Just did not offer details on its propriety process, it likely follows <a href="https://www.newscientist.com/article/mg24032080-400-accelerating-the-cultured-meat-revolution/" target="_blank" rel="noopener noreferrer">one similar to other lab-grown meats</a>. It starts with muscle cell samples drawn from a living animal. Technicians then isolate stem cells from the sample and culture them <em>in vitro</em>. These cultured stem cells are then placed in a bioreactor, essentially a fermenter for fleshy cells. The bioreactor contains scaffolding materials to keep the growing tissue from falling apart as well as a growth material—the sugars, salts, and other nutrients the tissue needs to grow. As the cells grow, they begin to differentiate into the muscle, fat, and other cells of meat tissue. Once grown, the tissues are formed into a meat product to be shipped to restaurants and supermarkets.</p>
An abattoir abatement?<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNDg2Mjg5OS9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYyODg1NDI3N30.AYmFJfWQbPjK-o1IatyFHL-OLjcfXBMmQKYyvz4oT3s/img.jpg?width=980" id="8a82d" class="rm-shortcode" data-rm-shortcode-id="93f824fe4c6f397ab2b65e4665847e71" data-rm-shortcode-name="rebelmouse-image" />
A graph showing the number of animals slaughtered in the United States per year from 1961–2018.
Credit: Our World in Data<p>Singapore's approval is an important step in support for clean meats—so-called because they don't require animal slaughter and would likely leave a reduced carbon footprint—but hurdles remain before widespread adoption is possible.</p><p>The most glaring is the price. The first lab-grown hamburger was eaten in London in 2013. <a href="https://www.bbc.com/news/science-environment-23576143" target="_blank" rel="noopener noreferrer">It cost roughly $330,000</a>. As with any new technology, investment, iteration, and improved manufacturing will see the price drop substantially and quickly. For comparison, Eat Just's chicken will be priced equivalent to premium chicken.</p><p>Other hurdles include up-scaling production, <a href="https://www.nature.com/articles/d41586-019-00373-w" target="_blank" rel="noopener noreferrer">the need for further research</a>, and developing techniques to reliably produce in-demand meats such as fish and beef. Finally, not all countries may be as receptive as Singapore. Countries with large, entrenched meat industries may protect this legacy industry through a protracted and difficult regulatory process. Though, the meat industry itself is investing in lab-grown meat. Tyson Foods, for example, has <a href="https://euromeatnews.com/Article-Tyson-Foods-announces-investment-in-clean-meat/697" target="_blank" rel="noopener noreferrer">invested in the food-tech startup Memphis Meats</a>, the company that debuted the world's first beef meatball.</p><p>"I would imagine what will happen is the U.S., Western Europe and others will see what Singapore has been able to do, the rigours of the framework that they put together. And I would imagine that they will try to use it as a template to put their own framework together," <a href="https://www.reuters.com/article/us-eat-just-singapore/singapore-approves-sale-of-lab-grown-meat-in-world-first-idUSKBN28C06Z" target="_blank" rel="noopener noreferrer">Tetrick told Reuter's during an interview</a>.</p><p>Regardless of the challenges, the demand for meat substitutes is present and growing. In 2020, plant-based substitutes like Beyond Meat and Impossible foods <a href="https://bigthink.com/coronavirus/plant-based-meat" target="_self">gained a significant foothold in supermarkets</a> as meat-packing factories became coronavirus hotspots. The looming threat of climate change has also turned people away from meat as animal products. Livestock production is environmentally taxing and leaves <a href="http://css.umich.edu/factsheets/carbon-footprint-factsheet" target="_blank" rel="noopener noreferrer">a much larger carbon footprint</a> than grain and vegetable production. </p><p>Then there's the moral concern of animal cruelty. In 2018 alone, 302 million cows, 656 million turkeys, 1.48 billion pigs, and a gob-smacking 68 billion chickens were <a href="https://ourworldindata.org/grapher/animals-slaughtered-for-meat" target="_blank" rel="noopener noreferrer">slaughtered for meat worldwide</a>. And those figures do not include chickens killed in dairy or egg production.</p><p>If brought to scale and widely available, clean meats could become serious competitors to traditional meat. <a href="https://bigthink.com/technology-innovation/meat-alternatives" target="_self">One report has even predicted</a> that 60 percent of the meat people eat by 2040 won't come from slaughtered animals. It could be just the thing for people looking for a meat substitute but who find tofurkey as distasteful as, well tofurkey.</p>
Researchers dramatically improve the accuracy of a number that connects fundamental forces.
- A team of physicists carried out experiments to determine the precise value of the fine-structure constant.
- This pure number describes the strength of the electromagnetic forces between elementary particles.
- The scientists improved the accuracy of this measurement by 2.5 times.
The process for measuring the fine-structure constant involved a beam of light from a laser that caused an atom to recoil. The red and blue colors indicate the light wave's peaks and troughs, respectively.
A new study finds that some people just want privacy.
- Despite its reputation as a tool for criminals, only a small percentage of Tor users were actually going to the dark web.
- The rate was higher in free countries and lower in countries with censored internet access.
- The findings are controversial, and may be limited by their methodology to be general assumptions.