In plants, the protein is called Luminidependens (LD), and it is normally involved in responding to daylight and controlling flowering time. When a part of the LD gene is inserted into yeast, it produces a protein that does not fold up normally, and which spreads this misfolded state to proteins around it in a domino effect that causes aggregates or clumps. Later generations of yeast cells inherit the effect: their versions of the protein also misfold.
Cougars and other cats have a need for protein that restricts them to a diet that’s primarily meat, gaining them the badass term “hypercarnivore.” Obviously, they don’t set out to eat plants, but they do wind up consuming a lot of seeds when they eat other animals that do.
Biologist José Hernán Sarasola has seen this first hand. He and his research team spent months collecting and picking through cougar scats in Argentina’s Parque Luro Natural Reserve, where the cats’ diet is mainly made up of eared doves. In just 123 scats, they found nearly 32,000 seeds from different plants that the doves feed on, the bulk of which came from three grasses. When they planted some of these seeds, they sprouted just fine, and passage through the cougars’ guts doesn’t seem to hurt them.
The three minute thesis competition - have final-year PhD students explain their research to a non-specialist audience in three minutes. A nice idea to encourage better science communication. Started in Australia, here's a report on a Caltech event.
General relativity tells us that as you get closer to a mass clocks run a bit more slowly. The effect can be observed on Earth with precise clocks at different distances from the center of the Earth and is pronounced enough that you have to correct for it to get the precise timing signals from GPS satellites right.
It follows that time runs more slowly at the center of a mass like the Earth. Apparently Feynman mentioned that, over the life of the Earth, the center of the Earth would be a day or two younger than its surface. The calculation is quite easy and one might expect it assigned as an undergrad physics problem.
It turns out that when you do a back of the envelop calculation you get about a year and a half. Feynman may have made a simple mistake or perhaps he was incorrectly quoted - apparently he never wrote the result down. I was unaware of his result, but I would have probably accepted it even though I had worked it out for distances from the earth (tall buildings, mountains, orbiting satellites).
The paper paper works out the result at the level of an undergrad physics class.
The young center of the Earth
U.I. Uggerhøj,1 R.E. Mikkelsen,1 and J. Faye2
1Department of Physics and Astronomy, Aarhus University, Denmark 2Department of Media, Cognition and Communication, University of Copenhagen, Denmark (Dated: April 20, 2016)
We treat, as an illustrative example of gravitational time dilation in relativity, the observation that the center of the Earth is younger than the surface by an appreciable amount. Richard Feynman first made this insightful point and presented an estimate of the size of the effect in a talk; a transcription was later published in which the time difference is quoted as ’one or two days’. However, a back- of-the-envelope calculation shows that the result is in fact a few years. In this paper we present this estimate alongside a more elaborate analysis yielding a difference of two and a half years. The aim is to provide a fairly complete solution to the relativity of the ’aging’ of an object due to differences in the gravitational potential. This solution - accessible at the undergraduate level - can be used for educational purposes, as an example in the classroom. Finally, we also briefly discuss why exchanging ’years’ for ’days’ - which in retrospect is a quite simple, but significant, mistake - has been repeated seemingly uncritically, albeit in a few cases only. The pedagogical value of this discussion is to show students that any number or observation, no matter who brought it forward, must be critically examined.
This research shows us that contrary to the previous belief that evolution is a very slow process, evolutionary changes can happen extremely rapidly. Thanks to recent advances in the technology of genetic sequencing, we can now watch genetic changes in populations as they evolve and adapt, as we did in this study. This approach opens up new windows onto evolution, showing us the details of this powerful and important process that constantly shapes life on earth. For any that doubt climate change or evolution, this study and many others provide key evidence of the reality and effects of these processes.
The field mustard plants in our study were able to rapidly adapt to climate change, and we could pinpoint the genetic changes that occurred that allowed this to happen. However, this does not mean that we don’t need to worry about climate change because species will just evolve. The rapid pace of current climate change and reduced population sizes due to habitat loss and fragmentation means that many species will not be able to adapt fast enough. A recent analysis concluded that 1 in 6 species could face extinction if climate change continues unabated. To avoid this massive and irretrievable loss of biological diversity, we need to take concrete steps to reduce our environmental impact and use energy and resources in a more sustainable way.
“We’re seeing evidence, on multiple levels, of accelerated aging among very young veterans—people in their early 30s,” says Erika Wolf, a MED assistant professor of psychiatry and a clinical research psychologist at the VA’s National Center for PTSD, who is lead author on the two studies. “These could snowball into major health problems down the road.”
“The idea that traumatic events can have a physical effect on people has been around for a long time,” says Mark Miller, a MED associate professor of psychiatry and the studies’ senior author. “Observations suggest that traumatic stress starts a cascade of biological consequences that can produce visible signs of aging. More recent research shows how this is happening on a cellular level, and for the first time we have the methods to actually see it in a person’s DNA.”
This one comes from Down Under, and it’s about a 22 year old woman named Carissa Gleeson, who hales from Western Australia and, as is so often the case, is portrayed as the picture of health. (Actually, before getting cancer, she was the She and her partner own a farm; she does lots of outdoorsy things. Before her cancer was diagnosed, she did a lot of farm work. Now she has a GoFundMe page to raise money for the quackery she has chosen to use. Meanwhile, I learned of her story in—where else?—The Daily Mail, although subsequently I found a more in-depth story on in Sunshine Coast Daily, a local paper, entitled Cowgirl chooses alternative therapies to treat cancer, complete with a photo of Gleeson and her partner looking like, well, a cowboy and cowgirl.
Over the last decade-plus, in assessing these alternative medicine cancer cure testimonials, I’ve learned what to look for and how to read between the lines. Those skills came in handy looking at Gleeson’s testimonial as told in these two sources and her GoFundMe page, as you will see. First, let’s take a look at how the Daily Fail presents her story: