The Invention of Recombinant DNA Technology
> In the early 1970s, a momentous series of events in the history of science unfolded at points around the San Francisco Bay. Lines of inquiry pursued at the Stanford University School of Medicine and the University of California, San Francisco converged on a set of discoveries that vastly expanded the productive capabilities of molecular genetics, disrupted the customary rhythms and routines of the scientific community, sparked bitter disputes about risks and responsibilities in scientific experimentation, and generated a tsunami of technological change that spread rapidly across multiple domains of productive activity and all around the globe.
> The first recombinant molecule containing DNA from different organisms was assembled late in 1971, in Paul Berg’s laboratory at Stanford. Berg hoped to transduce bacterial and mammalian cells with a recombinant virus in order to study gene expression systems, but subsequently chose not to carry out the planned experiments. He was persuaded by scientific colleagues to consider potential biohazard risks before moving ahead.
> The technology for propagating and expressing recombinant genes was invented by Stanley Cohen and Herbert Boyer in 1973. It enabled the transformation of bacterial cells into living factories for the directed manufacture of select proteins. The technology was immediately recognized as a tool without parallel in genetics research, and was soon applied to practical ends in a wide variety of fields including medicine, pharmaceuticals, agriculture, chemicals, and energy. It has since transformed the world in which we live.
> The history is complicated.
> A whole mangrove forest, lighting up all at once, plunging into darkness, then lighting up all again – in near-perfect synchrony. How do thousands of fireflies coordinate with each other? Who is the conductor of this silent symphony?
If you’re looking for gold, look in trees
> Prospecting for gold by looking for it in leaves has finally proved itself commercially in Australia
> The quantities are minuscule. In areas where there is no gold, leaves may have a background level of 0.15 parts per billion (ppb) of gold; on gold-rich sites that can rise to 4ppb.
Forced rhubarb – a vegetable deprived of sunlight for extra sweetness
> A notoriously fickle vegetable to harvest, Yorkshire forced rhubarb is anything but easy to grow. It thrives in the county’s cold winters, but if the soil is too wet, it can’t be planted. If the temperature is too hot, it won’t grow; and 10 or more frosts are needed before a farmer can even think about forcing it. Only then can horticulturalists remove the heavy roots from the field, then clean and replant them inside the forcing sheds where photosynthesis is limited, encouraging glucose stored in the roots to stimulate growth. It demands patience, expertise and good fortune, and, ultimately, it is engineered for maximum taste: once deprived of light, the vegetable is forced to use the energy stored in its roots, making it far sweeter than the normal variety.
X-ray imaging reveals the secrets of termite mounds
> Turner found that the assumptions of Pearce and others that the mounds’ complex tunnel systems serve to circulate air and remove heat to regulate interior temperatures isn’t accurate. The air mixing isn’t the result of the colony’s internal heat but air pressure from outside the mound. The termites build the mounds so tall to catch the wind, and their porous outer surface is what allows the air to move into and through the colony. Turner likens the effect to the alveoli in human lungs: the mound almost “breathes.”
The Plague Killing Frogs Everywhere Is Far Worse Than Scientists Thought
> Writing in the journal Science, the researchers conclude that populations of more than 500 species of amphibians have declined significantly because of the outbreak — including at least 90 species presumed to have gone extinct. The figure is more than twice as large as earlier estimates.
When Snails Attack: The Epic Discovery Of An Ecological Phenomenon
> The pair quickly realized that the ravenous whelks—an animal normally on the lobster’s menu—were why Marcus Island had no lobsters. “That was absolutely shattering, because here was a complete reversal of a normal predator-prey relationship,” said Branch—and the paper that resulted, published in Science in 1988, was the first study to document such a reversal.
Mammalian Near-Infrared Image Vision through Injectable and Self-Powered Retinal Nanoantennae
> Vision is an essential sensory modality for humans. Our visual system detects light between 400 and 700 nm (Dubois, 2009, Wyszecki and Stiles, 1982, Schnapf et al., 1988), so called visible light. In mammalian photoreceptor cells, light absorbing pigments, consisting of opsins and their covalently linked retinals, are known as intrinsic photon detectors. However, the detection of longer wavelength light, such as near-infrared (NIR) light, though a desirable ability, is a formidable challenge for mammals. This is because detecting longer wavelength light, with lower energy photons, requires opsins (e.g., human red cone opsins) to have much lower energy barriers. Consequently, this results in unendurable high thermal noise, thus making NIR visual pigments impractical (Ala-Laurila et al., 2003, Baylor et al., 1980, Luo et al., 2011, St George, 1952). This physical limitation means that no mammalian photoreceptor can effectively detect NIR light that exceeds 700 nm, and mammals are unable to see NIR light and to project a NIR image to the brain.
> To this end, the successful integration of nanoparticles with biological systems has accelerated basic scientific discoveries and their translation into biomedical applications (Desai, 2012, Mitragotri et al., 2015). To develop abilities that do not exist naturally, miniature nanoscale devices and sensors designed to intimately interface with mammals including humans are of growing interest. Here, we report on an ocular injectable, self-powered, built-in NIR light nanoantenna that can extend the mammalian visual spectrum to the NIR range. These retinal photoreceptor-binding upconversion nanoparticles (pbUCNPs) act as miniature energy transducers that can transform mammalian invisible NIR light in vivo into short wavelength visible emissions (Liu et al., 2017, Wu et al., 2009). As sub-retinal injections are a commonly used ophthalmological practice in animals and humans (Hauswirth et al., 2008, Peng et al., 2017), our pbUCNPs were dissolved in PBS and then injected into the sub-retinal space in the eyes of mice. These nanoparticles were then anchored and bound to the photoreceptors in the mouse retina.
Fixing photosynthesis by engineering it to recycle a toxic mistake
> And photosynthesis depends on an enzyme called RuBisCO, which uses carbon dioxide from the atmosphere to build sugars. So, by extension, RuBisCO may be the most important catalyst on the planet.
> Unfortunately, RuBisCO is, well, terrible at its job. It might not be obvious based on the plant growth around us, but the enzyme is not especially efficient at catalyzing the carbon dioxide reaction. And, worse still, it often uses oxygen instead. This produces a useless byproduct that, if allowed to build up, will eventually shut down photosynthesis entirely.
What is thoracic outlet syndrome, and what does it mean for Markelle Fultz?
In today’s edition of things to diagnose your friends with.
> Thoracic outlet syndrome (TOS) refers to a collection of signs and symptoms resulting from neurovascular compression at the thoracic outlet. The word neurovascular denotes the structures -- both nerve (neuro) and artery/vein (vascular) -- that might be compromised.
> The thoracic outlet is an anatomical region between the neck and the shoulder where key blood vessels and nerves travel en route to supply the upper extremity. Compression or abnormal pressure of structures in the thoracic outlet can be due to soft tissue (such as muscle or ligament) or bone (such as a normal rib, an extra rib or the collarbone) anomalies.
A better way to calculate pitch range
> Today’s topic is a simple solution to a complicated problem. The complicated problem is how to estimate “pitch range” in recordings of human speakers. As for the simple solution — wait and see.
> You might think that the many differences between the perceptual variable of pitch and the physical variable of fundamental frequency (“f0“) arise because perception is complicated and physics is simple. But if so, you’d be mostly wrong. The biggest problem is that physical f0 is a complex and often fundamentally incoherent concept. And even in the areas where f0 is well defined, f0 estimation (usually called “pitch tracking“) is prone to errors.
Myth of the Brown Recluse
> The next “spider” most familiar to Californians-the brown recluse-is a myth. There are no populations of brown recluse spiders living in California. In case, this upsets your applecart, I repeat, there are no populations of brown recluse spiders living in California.
Shawn Bradley Is Really, Really Tall. But Why?
> Bradley was not tall because of any genetic disorders. He was tall because of an uncommon blend of common genes.
> “Shawn had this incredibly unique combination of genetic variants,” Kauwe said. “Any one of them can be carried by any one of us. But he happens to have a whole lot of the ones that make you taller and very few of the ones that make you shorter.”
> What made it especially remarkable, though, was how unremarkable it was. There are thousands of SNPs, and every one of them has a small effect on height. Bradley was unusual because he had lots of little mutations that added up. It was like he’d been given a million dollars in pennies.
You See Less Than You Think
> The apparent richness of our perception is an illusion. The flow of our conscious experience is, in fact, remarkably sparse—not a fully detailed 3-D cinematic extravaganza, but a wonderfully evocative and continually evolving sketch, drawn in rapidly fading ink.
> The researchers modified the display so that, outside a moving 15-letter window around where the reader’s eye was looking, all the other words were replaced with strings of the letter “x.” Someone looking over the participant’s shoulder would see a small window of English text moving along the screen amid a sea of meaningless letters. But the reader noticed absolutely nothing unusual.
> Mr. Chater is a professor of behavioral science at Warwick Business School. This is adapted from his book “The Mind is Flat: The Remarkable Shallowness of the Improvising Brain,” being published Aug. 11 by Yale University Press.
The Obsessive Search for the Tasmanian Tiger
> The photos were part of Orchard’s arsenal of evidence against a skeptical world—proof of his fervent belief, shared with many in Tasmania, that the island’s apex predator, an animal most famous for being extinct, is still alive. The Tasmanian tiger, known to science as the thylacine, was the only member of its genus of marsupial carnivores to live to modern times.
> “Every other group is believers, and we’re skeptics, so we’re heretics,” Bill Flowers, one of the group’s three members, told me one day in a café in Devonport, on the northern coast. Since Flowers began investigating thylacine sightings, he has been reading about false memories, false confessions, and the psychology of perception—examples, he told me, of the way “the mind fills in gaps” that reality leaves open.
The True Story Of A Man-Eating Tiger's 'Vengeance'
> At the center of the story is Vladimir Markov, a poacher who met a grisly end in the winter of 1997 after he shot and wounded a tiger, and then stole part of the tiger’s kill. The injured tiger hunted Markov down in a way that appears to be chillingly premeditated. The tiger staked out Markov’s cabin, systematically destroyed anything that had Markov’s scent on it, and then waited by the front door for Markov to come home.
Better or worse fate than bowl of petunias?
Berserk leprosy bacteria are wildly mutating to become extremely drug resistant
> Strains of Mycobacterium leprae—the main bacterium behind leprosy*—are hypermutating and becoming extremely drug resistant. Researchers made the alarming discovery in a survey of 154 M. leprae genomes collected from 25 countries. The survey, published recently in Nature Communications, offers a rare genetic glimpse of the ancient, yet cryptic, bacterium, which still manages to cause 200,000 new cases worldwide each year.
Super-Black Is the New Black
> Feathers on birds of paradise contain light-trapping nanotechnology that makes some of the deepest blacks in the world.
> After the fall of the Roman Empire, elephants virtually disappeared from Western Europe. Since there was no real knowledge of how this animal actually looked, illustrators had to rely on oral and written transmissions to morphologically reconstruct the elephant, thus reinventing an actual existing creature. This tree diagram traces the evolution of the elephant depiction throughout the middle ages up to the age of enlightenment.