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Science is real fucking annoying. This should not exist in my life:
Originally Posted by :
When is a blue bird not blue? The answer to this question is always. There actually is no such thing as a blue bird. To find out why, Smithsonian Insider asked Scott Sillett, a wildlife biologist at the Smithsonian Migratory Bird Center.
“Red and yellow feathers get their color from actual pigments, called carotenoids, that are in the foods birds eat,” Sillett explains. “Blue is different―no bird species can make blue from pigments. The color blue that we see on a bird is created by the way light waves interact with the feathers and their arrangement of protein molecules, called keratin. In other words, blue is a structural color. Different keratin structures reflect light in subtly different ways to produce different shades of what our eyes perceive as the color blue. A blue feather under ultraviolet light might look uniformly gray to human eyes.”
Human semen, If you separated it out, would on average hold a 50/50 mix of sex chromosomes - half of the sperm bearing the Y chromosome, and half the X chromosome.
Despite all the myths about choosing the sex of your baby through superstitious rituals, there's not a lot we can do about changing those odds. And current techniques to separate out X and Y sperm outside the body are expensive and can damage the DNA within the cells.
But now, Japanese researchers have accidentally discovered an uncomfortably simple method to separate out the X-carrying sperm from the Y in mice – and this could have huge implications for humans-to-be in the future.
To understand the importance, let's back up to some biology basics for a second. In all mammals (and a number of other animals) females have XX chromosomes, and males have XY.
When a female produces an egg (aka ovum), it will only ever have one of the two X chromosomes – never a Y.
But the male sperm has an equal proportion of X-carrying and Y-carrying swimmers. Hypothetically, if there was something slightly different between the X and Y sperm, you could separate them out if you only wanted either females or males.
Until now we thought that the sperm were pretty much identical, except for the DNA that they carry.
But while studying the differences between X and Y sperm in mice, the Hiroshima University team found that there were around 500 genes active in X sperm that aren't in Y.
That's not super important by itself, but 18 of those genes code for proteins that stick out on the surface of the cell. They homed in on two particular receptors – called Toll-like receptors 7 and 8 on the surface of X sperm.
Using a chemical called resiquimod to bind to the receptors and slow the swimming of the X sperm, they were then able to separate the Y and X sperm with surprising accuracy.
When the researchers used resiquimod, and then used the fastest swimmers to fertilise some mice, the litters ended up being 90 percent male; when the slowest swimmers were used, the mouse babies were 81 percent female.
Although that's not perfect sex separation, it's really high, especially for such a simple and cheap method.
"The differential expression of receptor genes by the two sex chromosomes provides the basis for a novel and potentially highly useful method for separating X and Y sperm and we have already succeeded the selectively production of male or female in cattle and pig by this method," said one of the researchers, Masayuki Shimada, a reproductive biologist from Hiroshima University.
"Nonetheless, use of this method in human reproductive technology is speculative at the moment, and involves significant ethical issues unaffected by the utility of this new technique."
There can be some really good reasons to use sex selection in animals. For example, male cattle are not used in dairy production, and neither are male chickens in egg production. Being able to limit the conception of males in these sorts of situations has the potential to create more ethical farming.
But in humans, things get considerably messier.
Women currently account for 49.6 percent of the world's humans, but in some regions, couples can have strong preferences for a male child. Sex-selective practices have already led to some "alarming" demographic trends in some countries, which can have unintended social and economical effects.
As Michael Le Page at New Scientist explains, allowing for this discovery to be used in people could lead to gels or other home-use items that could significantly change the likelihood of a couple conceiving a girl.
"I am concerned about the social impact of this," genomics researcher Alireza Fazeli of Tartu University in Estonia told Le Page.
"It's so simple. You could start to do it in your bedroom. Nobody would be able to stop you from doing it."
BETHEL, Alaska (AP) - Record high temperatures in Alaska are believed to be the culprit behind salmon deaths in western Alaska.
Bethel-based KYUK reports water temperatures near the town broke into the low 70s earlier this week. That's the highest river temperature ever recorded there.
Ben Gray, a biologist with the state Department of Fish and Game, says that what could occur is that salmon metabolism speeds up to the point they are having heart attacks.
Residents along the lower Kuskokwim River have reported dead salmon floating downstream.
Gray and his colleagues counted about 20 dead salmon when they boated between Bethel and Akiak.
The warm water temperatures also are suspected to be the cause of parasites infesting salmon in the river.
Norton Sound residents have reported large numbers of dead pink salmon. [Reply]
80s/90s kids? Remember the creepy animated movie The Secret of NIMH? Ever wonder why the "NIMH" part was capitalized? Here's the creepy ass reason for that. It was based on a pretty nasty rat/mouse population experiment in the 50s/60s that was actually pretty terrifying. If you have 30 minutes to kill, this video is pretty crazy:
In The Secret of NIMH there are no musical interludes or tween heroines to lighten the mood—just the desperate struggle for survival of a mama mouse against her invariable predation. And it's based on a true story.
Don Bluth's The Secret of NIMH traces its roots back to the novel, Mrs. Frisby and the Rats of NIMH. And in both cases, NIMH stands for the National Institute of Mental Health. It's a division of the National Institutes of Health and is the single largest scientific organization dedicated to the study of mental health on Earth. And from the 1940s to 1960s, it was the site of some of the worst, most egregious atrocities against an animal population in the modern scientific era.
According to Edmund Ramsden of the WHO, author of The urban animal: population density and social pathology in rodents and humans:
In a 1962 edition of Scientific American, the ecologist John B Calhoun presented the results of a macabre series of experiments conducted at the National Institute of Mental Health (NIMH).1 He had placed several rats in a laboratory in a converted barn where – protected from disease and predation and supplied with food, water and bedding – they bred rapidly. The one thing they were lacking was space, a fact that became increasingly problematic as what he liked to describe as his "rat city" and "rodent utopia" teemed with animals. Unwanted social contact occurred with increasing frequency, leading to increased stress and aggression. Following the work of the physiologist, Hans Selye, it seemed that the adrenal system offered the standard binary solution: fight or flight.2 But in the sealed enclosure, flight was impossible. Violence quickly spiralled out of control. Cannibalism and infanticide followed. Males became hypersexual, pansexual and, an increasing proportion, homosexual. Calhoun called this vortex "a behavioural sink". Their numbers fell into terminal decline and the population tailed off to extinction. At the experiments' end, the only animals still alive had survived at an immense psychological cost: asexual and utterly withdrawn, they clustered in a vacant huddled mass. Even when reintroduced to normal rodent communities, these "socially autistic" animals remained isolated until death. In the words of one of Calhoun's collaborators, rodent "utopia" had descended into "hell".
NASA announced 19 new partnerships with 10 US companies to help bring more cutting-edge technologies closer to production use in spaceflight. There were a lot of useful engineering ideas here, such as precision landing systems and robotic plant farms, but perhaps the most intriguing one involved the rocket company SpaceX and two of NASA's field centers—the Glenn Research Center in Ohio and the Marshall Space Flight Center in Alabama.
"SpaceX will work with Glenn and Marshall to advance technology needed to transfer propellant in orbit, an important step in the development of the company’s Starship space vehicle," the NASA news release states. This is a significant announcement for reasons both technical and political.
For its part, SpaceX welcomed the opportunity to help advance NASA's Artemis Program, which NASA hopes will send humans to the Moon by 2024 (and, later on, to Mars). “We believe SpaceX’s fleet of advanced rockets and spacecraft, including Falcon Heavy and Starship, are integral to accelerating NASA’s lunar and Mars plans," a company spokesperson told Ars.
Technical
One of SpaceX's principal engineers behind the Starship project, Paul Wooster, has identified orbital refueling as one of most difficult technology challenges the company will have to overcome in order to realize its Mars ambitions.
Under some scenarios by which the company aims to send humans to Mars, a Super Heavy rocket would launch a Mars-bound Starship to low-Earth orbit. At that point, the spacecraft would need to top its fuel tanks back up in order to get its payload all the way to the Red Planet. It's estimated that five Starship launches' worth of fuel (as payload) would be required to refuel a single Mars-bound Starship in low-Earth orbit, and this would involve the transfer of hundreds of tons of methane and liquid oxygen.
Such refueling technology would also be useful for others besides NASA. "I’ve got a stack of studies that go from the floor to the ceiling that list the critical technologies needed for humans to become long-term explorers in deep space, and in-space refueling is always on the list," said Bobby Braun, a former chief technologist at NASA who is now dean of the College of Engineering and Applied Sciences at the University of Colorado Boulder. "It's the key for sustainability."
The new partnership recognizes SpaceX's maturity as a leading space transportation company, Braun said. And Glenn and Marshall are the right centers for SpaceX to partner with, even if there simultaneously exists a strong rivalry between SpaceX's low-cost rockets and Marshall's lead development of NASA's Space Launch System rocket.
NASA has previously done considerable work studying the handling, transfer of, and storage of rocket fuels such as liquid oxygen, hydrogen, and methane in space—they are difficult to work with and susceptible to boil off in the space environment (hydrogen atoms can even migrate directly through metal fuel tanks). Under the new Space Act Agreement, NASA's Space Technology program will fund the time the agency's people spend working on these problems and any agency test facilities used. In effect, teams from the company and agency will work together to solve the problem, each paying for its own part of the effort.
"The civil servants at Marshall and at Glenn are very talented in this area," Braun said. "The people at SpaceX clearly know their system, both the capabilities and the needs of the Starship architecture. The fact that they’re all going to get together in the same room, and work on the same problem, that’s tremendous."
Originally Posted by idrapethat:
So the weight of all the spiders in the world is like 5x that of humans...that's horrifying
The more you look, the scarier it gets. We weigh less than 1/3 of the world's viruses. And viruses are really, really small. I looked up the terms I didn't know, and we humans are the odd guests in a distinctly alien world. [Reply]
Originally Posted by idrapethat:
So the weight of all the spiders in the world is like 5x that of humans...that's horrifying
Originally Posted by Rain Man:
The more you look, the scarier it gets. We weigh less than 1/3 of the world's viruses. And viruses are really, really small. I looked up the terms I didn't know, and we humans are the odd guests in a distinctly alien world.
Originally Posted by idrapethat:
So the weight of all the spiders in the world is like 5x that of humans...that's horrifying
Also:
The world’s spiders consume somewhere between 400 million and 800 million tons of prey in any given year. That means that spiders eat at least as much meat as all 7 billion humans on the planet combined.
