PHOTOACTIVATION LOCALIZATION MICROSCOPY
Photomicrography by Harald Hess, Janelia Farms Research Institute, HHMI
Images and text reprinted here in abbreviated form.
Three images illustrating the limitation of traditional light microscopy and the power of a super-resolution technique called Photoactivation Localization Microscopy.
- When a microscope lens collects light from a molecule and reimages it onto a camera, the light forms a “blurry” spot that reflects the size of the light’s wavelength instead of the molecule’s size.
- This is called “diffraction,” and it restricts the resolution of light microscopy to ~1/2 the light’s wavelength (~250 nm) or approximately the size of a small mitochondrion.
- Thus, imaging with traditional light microscopy is like painting with a “blurry” brush. Individual molecules closer in space than ~250 nm will appear as one.
 Here a U2OS [human osteosarcoma] cell is labeled with fluorescent proteins and imaged with traditional microscopy using TIRF (total internal reflection) microscopy, with a resolution of ~250 nanometers.
 The same cell is now imaged with Photoactivation Localization Microscopy, shrinking the resolution from ~250 nm to 20 nm. Individual molecules of the membrane protein farnesyl labeled with a photoactivable fluorescent protein are distinguishable.
 The same cell is rendered using a high-speed version of the super-resolution technique. This allows real-time imaging in live cells. 3D images can be created by finding the axial position of each molecule with methods such as interferometry.
SOURCE: Zeiss Cell Picture Show
As in any conflict, “know your enemy” is a familiar mantra in cybersecurity. Many professionals aim to get into the hacking mind-set to defend against …
Hubble Sees a Star Set to Explode
Floating at the center of this new Hubble image is a lidless purple eye, staring back at us through space. This ethereal object, known officially as [SBW2007] 1 but sometimes nicknamed SBW1, is a nebula with a giant star at its center. The star was originally twenty times more massive than our sun, and is now encased in a swirling ring of purple gas, the remains of the distant era when it cast off its outer layers via violent pulsations and winds.
But the star is not just any star; scientists say that it is destined to go supernova. Twenty-six years ago, another star with striking similarities went supernova — SN 1987A. Early Hubble images of SN 1987A show eerie similarities to SBW1. Both stars had identical rings of the same size and age, which were travelling at similar speeds; both were located in similar HII regions; and they had the same brightness. In this way SBW1 is a snapshot of SN1987a’s appearance before it exploded, and unsurprisingly, astronomers love studying them together.
At a distance of more than 20 000 light-years it will be safe to watch when the supernova goes off. If we are very lucky it may happen in our own lifetimes.
Credit: ESA/NASA, acknowledgement: Nick Rose.
Bear’s Head Tooth Mushroom – Hericium americanum
It tastes like lobster or crab if prepared in butter, but can be bitter if old. It is also a great medical mushroom sort of a mental stimulant. It grows on living and dead deciduous trees. It can grow quite high in the tree. So you may have to climb to get one. Happy Hunting
I have only found 2 small Hericium’s this year.. both old and not edible. :(
Nova in Centaurus by Alex Cherney
Brightest stellar beacons of the constellation Centaurus, Alpha and Beta Centauri are easy to spot in southern sky scene from Victoria, Australia. However there is a “guest” new star, a nova, in this view, shining in the naked-eye visibility, next to Beta Centauri (the second brightest in the view).
Known as Nova Centauri 2013 this erupting star is an interacting binary system composed of a dense, hot white dwarf and cool, giant companion star. Material from the companion star builds up as it falls onto the white dwarf’s surface triggering a thermonuclear event. The cataclysmic blast results in a drastic increase in brightness and an expanding shell of debris. The stars are not destroyed and the nova can repeat in future.
How and Why did Newton Develop Such a Complicated Math?
To many people, there’s a certain four letter word that strikes great fear into their hearts: math. Mathematics has a reputation for being a subject of the elite—a terrible, confusing, jumbled mess of illogical expressions and rules, which many people just give up trying to decipher at some point. Nevertheless, many students of mathematics (formal and informal), persevere through years of algebra and arithmetic to find themselves facing a very different beast – Calculus.
In truth, mathematics IS complicated and advanced, and it took hundreds of years to develop this language—the language that can accurately describe the universe we live in. Initially, math arose to solve problems and predict outcomes in everyday life, and as humans became more interested in how the world worked, they were faced with limitations of their current mathematical theories – which is why many people throughout history worked to create new and better models of nature, leading to advanced mathematics – here is how Newton (among others) created some of the most dreaded mathematical equations that we know today.
Find out how here: http://www.fromquarkstoquasars.com/how-and-why-did-newton-develop-such-a-complicated-math/
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