I am asking for input on the best and most practical check valve for a duplex sewage ejector.
The existing System has a ball check made from schedule 80 PVC (GRAY) they seem to work OK but have problems with toys and you can imagine what else getting into the seats and keeping them from shutt
Pathologist, Train Thyself (in Genomics)! RNAi News ... significant shifts in medical education in decades," Saffitz, who is chief of Pathology at BIDMC and a professor of Pathology at Harvard Medical School, ... Pathologists call for new training program to support personalized medicinePhysOrg.com |
Is mulitcellular life like us just the new kid on the biological block, a latecomer to a world dominated by single-celled organisms like bacteria? Perhaps not—multicellular life could be nearly half as old as the Earth itself.
A new study out today in Nature identifies fossils from Gabon in Africa that date back 2.1 billion years. The organic material is long gone, but the scientists say these are the oldest multicellular organisms ever found. That date takes them way back before the Cambrian explosion 500 million years ago that made multiple-celled life widespread on the planet.
“We have these macrofossils turning up in a world that was purely microbial,” says Stefan Bengtson, a palaeozoologist at the Swedish Museum of Natural History in Stockholm and a co-author on the report. “That’s a big deal because when you finally get big organisms, it changes the way the biosphere works, as they interact with microbes and each other” [Nature].
It’s hard to know for sure that these specimens—which don’t have a name yet and grew up to five inches across—are truly multicellular, because no organic material remains. Sometimes bacteria live in larger sheets, and those aren’t true multicellular organisms. But in this case, study author Abderrazak El Albani says, the complex structure shown by the fossil remains show signs of communication between cells.
And, he says, the timing of these fossils suggests why the organism was able to become more complex: There was suddenly lots of oxygen back then.
Just a few million years before … the newly discovered fossils appear in the fossil record, Earth experienced what’s called the Great Oxidation Event. The sudden evolution of photosynthesizing bacteria radically changed Earth’s atmosphere, kick-starting its transformation from nearly oxygen-free into today’s breathable air [Wired.com].
With all that oxygen just waiting to be breathed, this was probably just one of many times multicellular life took off independently, according to paleontologist Philip Donoghue.
Importantly, even if these fossils are the oldest-known multicellular organisms, that doesn’t mean they were the ancestors of all multicellular life, Donoghue said. “Multicellularity hasn’t evolved just once; it’s evolved almost 20 times even amongst living lineages,” he said. “This is probably one of a great number of extinct lineages that experimented with [increased] organismal complexity” [The Scientist].
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Image: Abderrazak El Albani and Arnaud Mazurier
Alright guys, this might be kind of fun to ping around in your heads. I need a hanger to hold a piece of 9"x12" corrugated plastic on a standard chain link fence. Here's the rub, there are going to be lots of them and small children 2-5 years old have to be able to remove and rehang them easily and
Redefining the First Freedom: More than Worship Crosswalk.com We've talked about the so-called health care reform bill, which does not protect the freedom of conscience of medical practitioners. ... |
Of medical specialties, demand for psychiatrists growing fastest USA Today ... Association Council on Medical Education and Lifelong Learning and co-director of Medical Student Education in Psychiatry at Harvard Medical School. ... |
Twelve million years ago, one sperm whale was king. Between 40 and 60 feet in length the beast scientists named Leviathan melvillei wasn’t any bigger than today’s sperm whales, but look at those teeth!
As described in a paper published in Nature today, Olivier Lambert discovered the whale’s fossils in a Peruvian desert. The creature’s name says it all:
[It] combines the Hebrew word ‘Livyatan’, which refers to large mythological sea monsters, with the name of American novelist Herman Melville, who penned Moby-Dick — “one of my favourite sea books”, says lead author Olivier Lambert of the National Museum of Natural History in Paris. [Nature News]
The prehistoric sperm whale may have eaten baleen whales, and its largest chompers are a foot long and some four inches wide. For all the details, check out Ed Yong’s post on Not Exactly Rocket Science.
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Image: Nature
78 F-150 now has power climbing hills, thanks to all of your help.
Hey everyone, I have found the problem. The thick gasket under the carb has a crack through the gasket from overtightening, my fault. But thanks to you guys I discovered that I had two vac hoses switched and the fuel cap was n
Hi
I thought I will bring up this topic as my first post here. There don't seem to be many engineering degrees offered in instrumentation (not in Canada at least). So far I have seen engineers from different background (education wise) in this field. I myself am an electrical engineer by degree
A Spitzer Space Telescope image of a Brown Dwarf (?), Click for larger. Credit: NASA/JPL-Caltech/P. Eisenhardt (JPL)
This image shows what astronomers think is one of the coldest brown dwarfs discovered so far (red dot in middle of frame). The object, called SDWFS J143524.44+335334.6, is one of 14 such brown dwarfs found by NASA’s Spitzer Space Telescope using infrared light. Follow-up observations are required to nail down this “failed” star’s temperature, but rough estimates put this particular object at about 700 Kelvin (800 degrees Fahrenheit).
In this image, infrared light with a wavelength of 3.6 microns is color-coded blue; 4.5-micron light is red. The brown dwarf shows up prominently in red because methane is absorbing the 3.6-micron, or blue-coded, light.
The Spitzer Space telescope has found 14 brown dwarfs using its infrared vision. The image shows (they think) one of coldest found so far, it’s the red star in the center of the image. Cool in this case is only about 800 degrees, certainly no where near a true star. It has a name too: SDWFS J143524.44+335334.6, catchy eh? To be sure more observations will be necessary.
Brown dwarfs you will recall are essentially failed stars, they are small in terms of stellar mass and not hot enough to trigger the required thermonuclear reactions in their cores or if they manage a reaction they cannot sustain them. Why? Again they are too small and the heating creating by gravitational contraction just doesn’t make it.
Brown dwarfs are quite interesting objects. They are pretty much invisible because they are cool and just don’t give off much light. There is speculation that a brown dwarf might even be closer than the closest star to our sun, Proxima Centauri at 4.2 light-years. If there is one, the WISE spacecraft will hopefully find it.
The nation’s political focus this week is on the plodding confirmation hearings for Elena Kagan to become a Supreme Court justice. But if you need a break from choreographed political spectacle, it’s a good time to remember that the man she would replace, Justice John Paul Stevens, casts a long shadow over science and tech.
Ars Technica revisits Justice Stevens’ legacy—he was a onetime Navy cryptographer who helped Internet freedom by ruling against parts of the Communications Decency Act and opposing software patents. And if you still have drawers full of Star Trek: The Next Generation episodes you taped off TV, you have Stevens’ decision in Sony v. Universal to thank for that (as well as setting the precedent that stopped the music industry from suppressing mp3 players).
In that 1984 case, the Supreme Court came just one vote short of banning the Betamax VCR on the grounds that taping television shows off the air was an infringement of copyright. Justice Stevens wrote for a 5-4 majority that “time shifting”—the practice of recording shows for later viewing—was a fair use under copyright law. Stevens concluded that manufacturers were not liable for their customers’ infringement if their devices were capable of “substantial non-infringing use.” He noted that Congress was free to amend copyright law to give Hollywood control over VCR technology, but concluded that the courts shouldn’t do so unilaterally [Ars Technica].
You, sir, shall be missed.
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Image: Library of Congress
Once reserved for those who couldn’t pay their electricity bills or wanted to grow weed inside, snagging some free power via grappling hook is now a military operation. As described on the National Defense Education Network website, the Air Force has designed a “Bat Hook” which soldiers can heave into the air — action-hero style — to steal some juice from suspended power lines.
“We work very closely with Special Operations,” says Dave Coates, lead engineer on the project at Wright-Patterson Air Force Base (in the video below, and as shown by Popular Science). Their request? “Is there a way that you could possibly give us something like Batman?”
The Bat Hook system, technically called Remote Auxiliary Power System (RAPS), pierces the power line’s insulation to draw current directly where it’s needed, to charge batteries on the ground, for example.
Surprisingly this isn’t the only power line research ongoing at Wright-Patterson Air Force Base, and RASP isn’t the only comic book gadget that can perform on high wires. Air Force engineers are also in the midst of designing robotic flying cameras that can perch on the power lines. The parasitic cameras get their power from currents induced by the alternating magnetic fields surrounding the lines. Once they finish surveying, and charging their batteries (also from the stolen electricity), they can fly to another location.
Note: As warned in the film and suggested in our man-with-meat-hook vs. power line story, trying to Batman your own power line is just plain stupid.
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Image: Department of Defense
I'm a ME major at UCF and I could use some advice on selecting the right motor for a senior design project. For simplicity we would like a AC reversible motor able to run off of 120vac. The motor needs to have at least 20in-lbs torque but the kicker is we need it to run between 200-350 rpms which
NASA's Last Two Space Shuttle External Tanks Are Being Built at Michoud, Ken Kremer
"The last two Space Shuttle External Tanks (ET's) likely to be produced in history are entering their final closeout assembly operations at the NASA-owned Michoud Assembly Facility (MAF) in New Orleans as the shuttle program draws ever closer to its looming retirement date, now reset to early 2011. These two final tanks are destined for the last scheduled flight of the shuttle program - STS 134 - and what's currently base lined as the Launch-On-Need (LON) rescue mission (STS 335), respectively. They are designated as tanks ET-138 and ET-122. STS 134 is currently scheduled to lift off on Feb. 28, 2011."
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I would like to know what does SA stands for? fr e.g. SA 210 GrA
What is a floor sink? I cannot find any on the web. I assume a typical one is on the order of 6" x 6" x 6", with a 2" diameter outlet, to which you connect a trap, and route to the sewer pipe. One is being specified for almost every plumbing appliance in the kitchen.
It makes sense for an i
This is one of the first of our shiny new Discover galleries, loaded with great Leviathan pics. The full article is below.
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In today’s oceans, killer whales hunt other species of whales, working in packs to take down their much bigger prey. But living whales have it easy. Those that swam off the coast of Peru around 12 million years ago were hunted by a far bigger predator, a recently discovered animal with a very appropriate name: Leviathan.
Leviathan melvillei, named after the Biblical sea monster and the author of Moby Dick, was a giant sperm whale that has just been discovered by Belgian scientist Olivier Lambert. At between 13.5 and 18.5 metres in length, it was no bigger than the modern sperm whale, but it was clearly far more formidable.
Today’s sperm whale has no functional teeth in its upper jaw and only small ones in its lower jaw (which are mostly used in fights). It feeds through suction, relying on a rush of water to carry its prey into its open mouth. But Leviathan’s mouth was full of huge teeth, the largest of which were a foot long and around 4 inches wide. This was no suction feeder! Leviathan clearly grabbed its prey with a powerful bite, inflicting deep wounds and tearing off flesh as killer whales do, but with a skull three times bigger.
Leviathan was at the very top of the food chain and it must have needed a lot of food. While modern sperm whales mainly eat squid, Lambert thinks that Leviathan used its fearsome teeth to kill its own kind – the giant baleen whales. At the same point in prehistory, baleen whales started becoming much bigger and they were certainly the most common large animals in the area that Leviathan lived in. Lambert thinks that the giant predator evolved to take advantage of this rich source of energy. He says, “We think that medium-size baleen whales, rich in fat, would have been very convenient prey for Leviathan.”
It’s perhaps no coincidence that the biggest shark in history – the mighty Megalodon – also appeared at the same time in the same part of the world. It too was thought to have hunted whales and many of its teeth have also been found at Cerro Colorado. For the moment, it’s hard to say if the two predators were direct competitors, since they may have swum in different parts of the Peruvian seas. Lambert speculates that the adults of either species could have eaten the young of the other but there’s no evidence for this yet.
In the last few years, other smaller prehistoric sperm whales have been found in Peru and Italy. Their powerful teeth told us that these predators bit their prey in the manner of killer whales. The teeth were generally quite small but, as early as 1877, fossil hunters have found much larger teeth that looked very much like those of a sperm whale. The teeth provided tantalising hints of a much bigger animal but they were never accompanied by an actual skull. Their owner remained an enigma.
Lambert set out to find that skull in 2006, leading several expeditions into Peru’s Pisco-Ica desert. The digs weren’t fruitful but the team’s luck took a turn for the amazing at the very end. “In November 2008, on the last day of the field trip, my Dutch colleague Klaas Post discovered a very large cetacean skull,” says Lambert. “Usually large skulls belong to baleen whales, but Klaas immediately noted enormous teeth, both on the upper and lower jaw.” They had found Leviathan.
The skull is beautifully adapted to capture large, powerful prey. The snout was short and wide, allowing it to bite more strongly with its front teeth and resist the struggles of its prey. Its temporal fossa – the shallow depression on the side of the skull – was enormous and could old huge jaw-closing muscles. The bite would have been the largest of any tetrapod (the animal group that includes mammals, birds, reptiles and amphibians). And the teeth were deeply embedded in the jaw bones for each support, and interlocked to give the animal a shearing, meat-carving bite. They were also angled forwards, giving Leviathan a better grip on prey with curved bodies.
The skull also creates a mystery. Sperm whales have a unique organ in their heads called the spermaceti, and Leviathan’s was particularly large. The spermaceti is full of a waxy substance that was originally thought to be the animal’s sperm (hence the name). Its purpose isn’t clear although there are many theories, all of which must now be considered in the light of Leviathan’s very different lifestyle.
The sperm whale might use it to control its buoyancy during a dive by pumping in cold water, solidifying the wax and increasing the density of its head. At the depths, the energy expended during a hunt heats up the wax and melts it again. But Leviathan probably didn’t hunt for squid and probably wasn’t a deep-diver like the modern sperm whale. In light of this, other explanations become more intriguing. The case containing the spermaceti could be used as a battering ram during fights. It could also boost the sperm whale’s echolocation, allowing it to stun its prey with sound, or woo females (the male’s organ is particularly big).
Reference: Nature http://dx.doi.org/10.1038/nature09067
More on ancient whales:
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From VentureBeat: Interpreting Innovation:
Online maps are extremely useful, but not very innovative in their present form, as most maps we use today merely mirror paper maps. The road map serves most of our everyday needs, but as more and more data with a location component to it
