The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike protein enables viral entry into host cells by binding to the angiotensin-converting enzyme 2 (ACE2) receptor and is a major target for neutralizing antibodies. About 20 to 40 spikes decorate the surface of virions. Turoňová et al. now show that the spike is flexibly connected to the viral surface by three hinges that are well protected by glycosylation sites. The flexibility imparted by these hinges may explain how multiple spikes act in concert to engage onto the flat surface of a host cell.
Science, this issue p. 203.
By Beata Turoňová, Mateusz Sikora, Christoph Schürmann, Wim J. H. Hagen, Sonja Welsch, Florian E. C. Blanc, Sören von Bülow, Michael Gecht, Katrin Bagola, Cindy Hörner, Ger van Zandbergen, Jonathan Landry, Nayara Trevisan Doimo de Azevedo, Shyamal Mosalaganti, Andre Schwarz, Roberto Covino, Michael D. Mühlebach, Gerhard Hummer, Jacomine Krijnse Locker, Martin Beck.
If Dr. Ken Berry actually meant to say that you need to eat saturated fat for your nerves and brain, he flunks Biochem 101. First of all, your body can make all the saturated fat you need out of carbs and proteins. You don’t need to eat ANY saturated fat. Second, the most common fatty acid in your brain is the polyunsaturated fatty acid (PUFA) called DHA, which you DO need to eat, because you can’t make it from non-fats (you need to eat it or EPA in things like seafood, or at least the precursor omega-3 PUFA called ALA in cold-climate plants.) Ironically enough, ALA is common in Canola oil, which Dr. Berry deprecates, but not in the tropical plant oils that he likes. More on that later.
A diet with a lot of saturated fat is NOT the best for the heart. The American Heart Association continues to recommend low saturated fat diets (with the missing sat-fat replaced by mono and polyunsaturated fat, not by carbohydrates) because the evidence from animal and human trials and even properly controlled epidemiology, shows these the best diets (see reference below—an extensive review of meta analyses [1]). Examples are the DASH hypertension diet and the closely-related Mediterranean diet (which has lots of olive oil for monounsaturated fatty acid, and seafood for DHA). If Dr. Berry thinks he has something better than the Mediterranean diet for longevity, what is his direct evidence?
Saturated fat, of course, is used by the body to make cholesterol (you don’t need to eat any cholesterol for this reason), and it does raise cholesterol levels and it does increase atherosclerosis in nearly every controlled prospective experimental model in animals and humans. This is the gold standard of evidence in medicine.
One can go only so far with epidemiology, because occasionally when one bad thing (saturated fat) is heavily replaced for calories by another bad thing (certain carbohydrates) one detects no epidemiologic effect from changing just the first thing.
That happens with various high and low saturated fat diets around the world enough to make saturated fat look benign as a single input variable. It is not. Rather, what these studies really show is that replacing butter with sugar or high glycemic carbs gives you a diet equally bad for the arteries. One cannot see how bad that is, until one compares these with low-carbohydrate, low-saturated-fat diets, which are less common, but better. The double-negative tradeoff of carbs and saturated fats (where carbs are a statistical “confounder”) is one of those occasional cruel misdirectional things that happen with imperfectly controlled past-observations, but (again) it’s why biomedical knowledge consists of more than just epidemiology.
An Amazon Prime-like service to deliver weapons? Well, that is what Elon Musk is working on. Yes, rockets that can deliver weapons to US Armed Forces stationed anywhere in the world.
That prompted the researchers, who are part of the Human Brain Project, to look at two features that have become clear in experimental neuroscience data: each neuron retains a memory of previous activity in the form of molecular markers that slowly fade with time; and the brain provides top-down learning signals using things like the neurotransmitter dopamine that modulates the behavior of groups of neurons.
In a paper in Nature Communications, the Austrian team describes how they created artificial analogues of these two features to create a new learning paradigm they call e-prop. While the approach learns slower than backpropagation-based methods, it achieves comparable performance.
More importantly, it allows online learning. That means that rather than processing big batches of data at once, which requires constant transfer to and from memory that contributes significantly to machine learning’s energy bills, the approach simply learns from data as it becomes available. That dramatically cuts the amount of memory and energy it requires, which makes it far more practical to use for on-chip learning in smaller mobile devices.
The Solar Mapper uses artificial intelligence algorithms that compile data extracted from satellite images. It can estimate site solar potential and indicate the most suitable technology.
The top U.S. carrier has launched a blanket layer of 5G coverage, guaranteeing that more users will see a 5G logo on new phones, but not faster speeds.
If Dr. Ken Berry actually meant to say that you need to eat saturated fat for your nerves and brain, he flunks Biochem 101. First of all, your body can make all the saturated fat you need out of carbs and proteins. You don’t need to eat ANY saturated fat. Second, the most common fatty acid in your brain is the polyunsaturated fatty acid (PUFA) called DHA, which you DO need to eat, because you can’t make it from non-fats (you need to eat it in things like seafood, or at least the precursor omega-3 PUFA called ALA in cold-climate plants.) Ironically enough ALAis common in Canola oil, which Dr. Berry deprecates, but not in the tropical plant oils he likes. More on that later. A diet with a lot of saturated fat is NOT the best for the heart. The American Heart Association continues to recommend low saturated fat diets (with the missing sat-fat replaced by mono and polyunsaturated fat, not by carbohydrates) because the evidence from animal and human trials and even properly controlled epidemiology, shows these the best diets (see reference below–an extensive review of meta analyses [1]). Examples are the DASH hypertension diet and the closely-related Mediterranean diet (which has lots of olive oil for monounsaturated fatty acid, and seafood for DHA). If Dr. Berrythinks he has something better than the Mediterranean diet for longevity, what is his direct evidence? Saturated fat, of course, is used by the body to make cholesterol (you don’t need to eat any cholesterol for this reason), and it does raise cholesterol levels and it does increase atherosclerosis in nearly every controlled prospective experimental model in animals and humans. This is the gold standard of evidence in medicine.
One can go only so far with epidemiology, because occasionally when one bad thing (saturated fat) is heavily replaced for calories by another bad thing (certain carbohydrates) one detects no epidemiologic effect from changing just the first thing.
That happens with various high and low saturated fat diets around the world enough to make saturated fat look benign as a single input variable. It is not. Rather, what these studies really show is that replacing butter with sugar or high glycemic carbs gives you a diet equally bad for the arteries. One cannot see how bad that is, until one compares these with low-carbohydrate, low-saturated-fat diets, which are less common, but better. The double-negative tradeoff of carbs and saturated fats (where carbs are a statistical “confounder”) is one of those occasional cruel misdirectional things that happen with imperfectly controlled past-observations, but (again) it’s why biomedical knowledge consists of more than just epidemiology. The saturated oils Dr. Berryrecommends are by themselves on the edge of PUFA deficiency. This can be dramatic: for example the only way I know to give dogs atherosclerosis nutritionally, is to feed them just coconut oil for fat, and NO monounsaturates or PUFA. Apparently a little PUFA is extremely important for the heart, and larger amounts do no harm. There are hints that high PUFA diets are risks for certain cancers, but that merely underscores the need to get monounsaturates like olive and Canola where one can, and some PUFA foods. I know of no civilization that eats a lot of coconut oil that doesn’t eat seafood as well, so that combination is safe. Canola oil is merely rapeseed oil bred to remove erucic acid and other potential toxins. It is high in monounsaturates and ALAand of all the plant oils is probably closest to optimal for human nutrition. Olive oil is probably better than Canola for frying, since ALAwill oxidize, but Canola’s ALA is very important for vegans who need an omega-3 PUFA plant oil to convert to brain DHA. Seafood and olive oil are a fine replacement for Canola, but the person who cannot eat meat or seafood had better look for a baking and salad oil with ALA in it, and Canola oil is the best for this. Linseed oil is hard to digest and hard to work with, so that leaves Canola as the best omega-3 alternative for vegans. Dr. Berry never mentions his problem with Canola beyond saying it is GMO. But he is wrong there, as it doesn’t have to be. Canola as a product (1970’s) was created with hybrid not GMO techniques, and although GMO Canolas exist now, there also exist certified non-GMO and “organic” Canola oils which are labeled with a butterfly and tested to make sure no GMO Canola has crept in (there are tests available for this too complicated to go into here, but you can be sure).
In short, the ONLY part of Dr. Berry’s piece I agree with is dumping your hydrogenated shortening products (Crisco, etc.) in the garbage. That’s why I give this segment a D, rather than the F it otherwise deserves.
SpaceX disclosed the benchmarks in a presentation the company sent to the FCC last Friday. It also revealed the public beta for Starlink is coming to multiple US states.
The 2 Gig service is targeting households with heavy internet users who are now forced to work from home due to COVID-19. “So we’re more than a little excited to announce 2 Gig today—bringing even more bandwidth and speed to customers in internet-intensive households who may need more than a gig to do their thing, whatever that may be,” wrote Amalia O’Sullivan, Google Fiber’s director of product management, in the announcement. (That said, upload speeds will remain at 1Gbps.)
Google Fiber is currently looking for subscribers in Nashville, Tennessee, and Huntsville, Alabama, to sign up as testers for the 2 Gig service. The beta will then roll out to other Google Fiber cities in the fall before the official launch. Interested customers can also go to the Google Fiber website to sign up for email updates on the 2Gbps service’s availability.
