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Scientists create precursor to life in thermal vent experiment
Scientists speculate that if life were to have spontaneously developed on Earth, the first thing there would need to be are vesicles.
- The findings also suggest that life may have formed in the deep oceans of other celestial bodies in our solar system as well.
- These are a lot like cell membranes, only they don't contain any of the complicated machinery that real, living cells do.
- Researchers recently demonstrated that these vesicles form frequently in environments similar to the hydrothermal vents of early Earth.
One of the hallmarks of life is homeostasis, or the ability for life to maintain a consistent internal state regardless of external conditions. Think of how you sweat to cool down, or how you need to drink water every now and again to maintain fluid levels.
This need to maintain homeostasis is present in all forms of life by definition. But in order for there to be homeostasis, there needs to be an inside and an outside. Now, a new study published in Nature Ecology & Evolution on November 4, may have identified how life first developed the barriers between cells' insides and their outsides.
What are vesicles?
Examples of a lipid bilayer, a liposome (a.k.a., a vesicle, or a protocell), and a micelle, which is a type of structure composed of only one layer of lipids.
Image source: Wikimedia Commons
Biologists believe that before life could develop on Earth, the first thing that needed to occur was the development of protocells. You can think of this like a cell minus all of the machinery that makes a cell work. Instead, a protocell is just composed of a membrane that defines inside and outside.
Nearly every organism's cell membrane is composed of a lipid bilayer, meaning that it's likely that life started out with these bilayers. A lipid is what's known as an amphiphilic molecules, which are molecules that have one side attracted to water and one side repelled by it. When there are two "sheets" of these molecules, they can form a barrier where the water-loving heads of the molecules face outward while the water-hating tails face inward. Sometimes, these sheets also form a sphere, or vesicle. These vesicles are essentially cell membranes.
Many scientists believe that the formation of vesicles was the first step toward life. Vesicles keep certain material out of the protocell while protecting an internal solution — homeostasis. But the question of where and how they formed is less clear.
Could vesicles have formed around hydrothermal vents?
An artists depiction of the water vapor plumes found on Enceladus, which are believed to caused by subsurface hydrothermal vents.
Image source: NASA / JPL-Caltech
The earliest direct evidence of life dates back to 3.5 billion years ago in the form of fossilized microorganisms, but life clearly existed before then. A 2017 study claims to have identified fossilized microorganisms dating back to 4.28 billion years ago, a mere 400 million years after the formation of the Earth itself. But this finding is contested, not just because it implies life sprang into action as soon as it could but because of where it was found: in the precipitate of hydrothermal vents.
The interesting chemistry and energy source that characterized hydrothermal vents has long made them a candidate for the origin of life, but experiments have failed to demonstrate that vesicles can form there. The environment around hydrothermal vents in the Hadean/early Archaean period when life began was highly alkaline, or basic, and extremely salty, even saltier than today's oceans are. When scientists attempted to create vesicles under such conditions, they simply fell apart, leading some scientists to argue that life probably began in freshwater pools, away from the highly alkaline and salty environment of hydrothermal vents.
However, this new study indicates that not only can protocells develop in this environment, it actually encourages their development. One of the study's authors, Dr. Sean Jordan, explains why their results were different: "Other experiments had all used a small number of molecule types, mostly with fatty acids of the same size, whereas in natural environments, you would expect to see a wider array of molecules."
Then and now.
Prior experiments were extremely precise, failing to replicate that messier nature of the hydrothermal vent environment — Jordan's experiment, however, featured numerous amphiphilic molecules. In fact, molecules with longer carbon chains required the heat of a hydrothermal vent to form vesicles, the alkalinity helped the vesicles keep their electrical charge, and the salt in the solution ensured helped the molecules pack together more tightly.
Not only does this suggest that life on Earth may have started in the deep oceans by hydrothermal vents, it also points to places in our solar system where life may develop or have developed as well. Celestial objects such as Europa, one of Jupiter's moons, may harbor life despite the miles-deep shell of ice that encases it. The moon's orbit constantly squeezes and unsqueezes it, providing heat for a liquid subsurface ocean that observations suggest may be salty and alkaline as well. Saturn's moon Enceladus is covered in geysers shooting water vapor, thought to be caused by hydrothermal vents, that contain salts and organic compounds.
Together, these facts paint a picture about the formation of life; not only might life first develop deep in the ocean near hydrothermal vents, but it might develop as soon as its able, and often. If this finding is backed up by further evidence, and if we find that life began nearly as soon as the oceans formed on Earth, we may have a very good shot at finding life in our solar system on the moons of Jupiter and Saturn.
Andy Samberg and Cristin Milioti get stuck in an infinite wedding time loop.
- Two wedding guests discover they're trapped in an infinite time loop, waking up in Palm Springs over and over and over.
- As the reality of their situation sets in, Nyles and Sarah decide to enjoy the repetitive awakenings.
- The film is perfectly timed for a world sheltering at home during a pandemic.
Richard Feynman once asked a silly question. Two MIT students just answered it.
Here's a fun experiment to try. Go to your pantry and see if you have a box of spaghetti. If you do, take out a noodle. Grab both ends of it and bend it until it breaks in half. How many pieces did it break into? If you got two large pieces and at least one small piece you're not alone.
But science loves a good challenge<p>The mystery remained unsolved until 2005, when French scientists <a href="http://www.lmm.jussieu.fr/~audoly/" target="_blank">Basile Audoly</a> and <a href="http://www.lmm.jussieu.fr/~neukirch/" target="_blank">Sebastien Neukirch </a>won an <a href="https://www.improbable.com/ig/" target="_blank">Ig Nobel Prize</a>, an award given to scientists for real work which is of a less serious nature than the discoveries that win Nobel prizes, for finally determining why this happens. <a href="http://www.lmm.jussieu.fr/spaghetti/audoly_neukirch_fragmentation.pdf" target="_blank">Their paper describing the effect is wonderfully funny to read</a>, as it takes such a banal issue so seriously. </p><p>They demonstrated that when a rod is bent past a certain point, such as when spaghetti is snapped in half by bending it at the ends, a "snapback effect" is created. This causes energy to reverberate from the initial break to other parts of the rod, often leading to a second break elsewhere.</p><p>While this settled the issue of <em>why </em>spaghetti noodles break into three or more pieces, it didn't establish if they always had to break this way. The question of if the snapback could be regulated remained unsettled.</p>
Physicists, being themselves, immediately wanted to try and break pasta into two pieces using this info<p><a href="https://roheiss.wordpress.com/fun/" target="_blank">Ronald Heisser</a> and <a href="https://math.mit.edu/directory/profile.php?pid=1787" target="_blank">Vishal Patil</a>, two graduate students currently at Cornell and MIT respectively, read about Feynman's night of noodle snapping in class and were inspired to try and find what could be done to make sure the pasta always broke in two.</p><p><a href="http://news.mit.edu/2018/mit-mathematicians-solve-age-old-spaghetti-mystery-0813" target="_blank">By placing the noodles in a special machine</a> built for the task and recording the bending with a high-powered camera, the young scientists were able to observe in extreme detail exactly what each change in their snapping method did to the pasta. After breaking more than 500 noodles, they found the solution.</p>
The apparatus the MIT researchers built specifically for the task of snapping hundreds of spaghetti sticks.
(Courtesy of the researchers)
What possible application could this have?<p>The snapback effect is not limited to uncooked pasta noodles and can be applied to rods of all sorts. The discovery of how to cleanly break them in two could be applied to future engineering projects.</p><p>Likewise, knowing how things fragment and fail is always handy to know when you're trying to build things. Carbon Nanotubes, <a href="https://bigthink.com/ideafeed/carbon-nanotube-space-elevator" target="_self">super strong cylinders often hailed as the building material of the future</a>, are also rods which can be better understood thanks to this odd experiment.</p><p>Sometimes big discoveries can be inspired by silly questions. If it hadn't been for Richard Feynman bending noodles seventy years ago, we wouldn't know what we know now about how energy is dispersed through rods and how to control their fracturing. While not all silly questions will lead to such a significant discovery, they can all help us learn.</p>
What happens if we consider welfare programs as investments?
- A recently published study suggests that some welfare programs more than pay for themselves.
- It is one of the first major reviews of welfare programs to measure so many by a single metric.
- The findings will likely inform future welfare reform and encourage debate on how to grade success.
Welfare as an investment<p>The <a href="https://scholar.harvard.edu/files/hendren/files/welfare_vnber.pdf" target="_blank">study</a>, carried out by Nathaniel Hendren and Ben Sprung-Keyser of Harvard University, reviews 133 welfare programs through a single lens. The authors measured these programs' "Marginal Value of Public Funds" (MVPF), which is defined as the ratio of the recipients' willingness to pay for a program over its cost.</p><p>A program with an MVPF of one provides precisely as much in net benefits as it costs to deliver those benefits. For an illustration, imagine a program that hands someone a dollar. If getting that dollar doesn't alter their behavior, then the MVPF of that program is one. If it discourages them from working, then the program's cost goes up, as the program causes government tax revenues to fall in addition to costing money upfront. The MVPF goes below one in this case. <br> <br> Lastly, it is possible that getting the dollar causes the recipient to further their education and get a job that pays more taxes in the future, lowering the cost of the program in the long run and raising the MVPF. The value ratio can even hit infinity when a program fully "pays for itself."</p><p> While these are only a few examples, many others exist, and they do work to show you that a high MVPF means that a program "pays for itself," a value of one indicates a program "breaks even," and a value below one shows a program costs more money than the direct cost of the benefits would suggest.</p> After determining the programs' costs using existing literature and the willingness to pay through statistical analysis, 133 programs focusing on social insurance, education and job training, tax and cash transfers, and in-kind transfers were analyzed. The results show that some programs turn a "profit" for the government, mainly when they are focused on children:
This figure shows the MVPF for a variety of polices alongside the typical age of the beneficiaries. Clearly, programs targeted at children have a higher payoff.
Nathaniel Hendren and Ben Sprung-Keyser<p>Programs like child health services and K-12 education spending have infinite MVPF values. The authors argue this is because the programs allow children to live healthier, more productive lives and earn more money, which enables them to pay more taxes later. Programs like the preschool initiatives examined don't manage to do this as well and have a lower "profit" rate despite having decent MVPF ratios.</p><p>On the other hand, things like tuition deductions for older adults don't make back the money they cost. This is likely for several reasons, not the least of which is that there is less time for the benefactor to pay the government back in taxes. Disability insurance was likewise "unprofitable," as those collecting it have a reduced need to work and pay less back in taxes. </p>
What are the implications of all this?<div class="rm-shortcode" data-media_id="ceXv4XLv" data-player_id="FvQKszTI" data-rm-shortcode-id="3b407f5aa043eeb84f2b7ff82f97dc35"> <div id="botr_ceXv4XLv_FvQKszTI_div" class="jwplayer-media" data-jwplayer-video-src="https://content.jwplatform.com/players/ceXv4XLv-FvQKszTI.js"> <img src="https://cdn.jwplayer.com/thumbs/ceXv4XLv-1920.jpg" class="jwplayer-media-preview" /> </div> <script src="https://content.jwplatform.com/players/ceXv4XLv-FvQKszTI.js"></script> </div> <p>Firstly, it shows that direct investments in children in a variety of areas generate very high MVPFs. Likewise, the above chart shows that a large number of the programs considered pay for themselves, particularly ones that "invest in human capital" by promoting education, health, or similar things. While programs that focus on adults tend to have lower MVPF values, this isn't a hard and fast rule.</p><p>It also shows us that very many programs don't "pay for themselves" or even go below an MVPF of one. However, this study and its authors do not suggest that we abolish programs like disability payments just because they don't turn a profit.</p><p>Different motivations exist behind various programs, and just because something doesn't pay for itself isn't a definitive reason to abolish it. The returns on investment for a welfare program are diverse and often challenging to reckon in terms of money gained or lost. The point of this study was merely to provide a comprehensive review of a wide range of programs from a single perspective, one of dollars and cents. </p><p>The authors suggest that this study can be used as a starting point for further analysis of other programs not necessarily related to welfare. </p><p>It can be difficult to measure the success or failure of a government program with how many metrics you have to choose from and how many different stakeholders there are fighting for their metric to be used. This study provides us a comprehensive look through one possible lens at how some of our largest welfare programs are doing. </p><p>As America debates whether we should expand or contract our welfare state, the findings of this study offer an essential insight into how much we spend and how much we gain from these programs. </p>
Finding a balance between job satisfaction, money, and lifestyle is not easy.
- When most of your life is spent doing one thing, it matters if that thing is unfulfilling or if it makes you unhappy. According to research, most people are not thrilled with their jobs. However, there are ways to find purpose in your work and to reduce the negative impact that the daily grind has on your mental health.
- "The evidence is that about 70 percent of people are not engaged in what they do all day long, and about 18 percent of people are repulsed," London Business School professor Dan Cable says, calling the current state of work unhappiness an epidemic. In this video, he and other big thinkers consider what it means to find meaning in your work, discuss the parts of the brain that fuel creativity, and share strategies for reassessing your relationship to your job.
- Author James Citrin offers a career triangle model that sees work as a balance of three forces: job satisfaction, money, and lifestyle. While it is possible to have all three, Citrin says that they are not always possible at the same time, especially not early on in your career.