The Incredible Eye
The eye stands as a testament to the effectiveness and magnitude of what can be achieved through natural selection. These extraordinary false-colour SEM images of the human eye were the brainchild of Professor Pietro Motta at the Institute of Human Anatomy of the University La Sapienza in Rome.
Top Left: Surface cells on the iris of the eye. Pigment cells (melanocytes, blue and brown) can be seen here, joined loosely together by connective tissue fibres (white). Smaller macrophage cells dot the surface.
Top Right: Lens of the eye. Lens cells run diagonally (dark green) across this field of view. The transparency of the lens (width 4 millimetres) is due to the absence of nuclei in these cells, and to the crystalline precision of their arrangement.
Centre: The inner surfaces of the iris and adjoining structures in the human eye. At far right (blue) is the edge of the pupil, the hole that allows light into the eye. Coloured mauve is the iris which controls the size of the pupil and therefore how much light will enter. The band of folds down the centre (red) are the ciliary processes.
Bottom left: The surface of the cornea. The matrix- like pattern (seen here) consists of individual flattened transparent cells. This is a stratified squamous epithelium which is 5 cell layers deep. Although full of nerves, there are no blood vessels in the cornea.
Bottom right: The human retina featuring the central fovea, a crater-like depression in the photosensitive layer of the eye. The foveal retina is the area of greatest visual acuity and contains only cone receptor cells. When an eye looks at an object, that part focused on the fovea is the portion most accurately registered by the brain.
All image credit goes to Professor Pietro Motta and Science Photo Library.
Jumping in the Timeriver
Time is essential for the human mind and for anyone's flow of ideas. Consequently you'll find in the mesmerizing grid and flow of time the sparkles and the flashes of what makes us human and thus unique.
This negative stained transmission electron micrograph (TEM) depicts a number of filamentous Marburg virions, which had been cultured on Vero cell cultures, and purified on sucrose, rate-zonal gradients. Note the virus’s morphologic appearance with its characteristic “Shepherd’s Crook” shape; Magnified approximately 100,000x.
Marburg hemorrhagic fever is a rare, severe type of hemorrhagic fever which affects both humans and non-human primates. Caused by a genetically unique zoonotic (that is, animal-borne) RNA virus of the filovirus family, its recognition led to the creation of this virus family. The four species of Ebola virus are the only other known members of the filovirus family. Marburg virus was first recognized in 1967, when outbreaks of hemorrhagic fever occurred simultaneously in laboratories in Marburg and Frankfurt, Germany and in Belgrade, Yugoslavia (now Serbia).
Personal comment : I’ve first heard of this family of viruses in an excellent Canadian tv series ReGenesis.
Legal highs making the drug war obsolete
If you want any evidence that drugs have won the drug war,
you just need to read the scientific studies on legal highs.
If you’re not keeping track of the ‘legal high’ scene it’s important to remember that the first examples, synthetic cannabinoids sold as ‘Spice’ and ‘K2′ incense, were only detected in 2009.
Shortly after amphetamine-a-like stimulant drugs, largely based on variations on pipradrol and the cathinones appeared, and now ketamine-like drugs such as methoxetamine have become widespread.
(Source: sociologic, via cosmicrevolutionary)
One’s character is hidden behind one’s tongue.
Imam Ali (a.s.)
(Source: thelittlephilosopher, via cosmicrevolutionary)
91
DRUGS DRUGS DRUGS!
Let’s talk about Phencyclidine a.k.a PCP.
It is a dissociative drug formerly used as an anesthetic agent, exhibiting hallucinogenic and neurotoxic effects. Although the primary psychoactive effects of the drug only last hours, total elimination from the body is prolonged, typically extending over weeks.
PCP works primarily as an NMDA receptor antagonist, which blocks the activity of the NMDA receptor and, like most antiglutamatergic hallucinogens, is significantly more dangerous than other categories of hallucinogens.
Behavioral effects can vary by dosage. Low doses produce a numbness in the extremities and intoxication, characterized by staggering, unsteady gait, slurred speech, bloodshot eyes, and loss of balance. Moderate doses (5–10 mg intranasal, or 0.01–0.02 mg/kg intramuscular or intravenous) will produce analgesia and anesthesia. High doses may lead to convulsions.
This is a really dangerous drug. It is addictive and causes brain damage.
29Mustafa’s Space Drive: An Egyptian Student’s Quantum Physics Invention
BY KIT EATON |
Remember the name, because you might see it again: Aisha Mustafa, a 19-year-old Egyptian physics student, patented a new type of propulsion system for spacecraft that uses cutting edge quantum physics instead of thrusters.
First, a little background: One of the strange quantum facts at work in Mustafa’s engine idea is that there’s no such thing as a vacuum, devoid of particles, waves, and energy. Instead the universe’s supposedly empty spaces are filled with a roiling sea of particles and anti-particles that pop into existence, then annihilate each other in such a short space of time that you can’t readily detect them.
Mustafa invented a way of tapping this quantum effect via what’s known as the dynamic Casimir effect. This uses a “moving mirror” cavity, where two very reflective very flat plates are held close together, and then moved slightly to interact with the quantum particle sea. It’s horribly technical, but the end result is that Mustafa’s use of shaped silicon plates similar to those used in solar power cells results in a net force being delivered. A force, of course, means a push or a pull and in space this equates to a drive or engine.
In terms of space propulsion, this is amazing. Most forms of spacecraft rely on the rocket principle to work: Some fuel is made energetic and then thrust out of an engine, pushing the rocket forward. It’s tricky stuff to get right, particularly on Earth, which is why we shouldn’t be surprised SpaceX’s recent launch stopped at the critical moment due to a problem with one of its chemical rocket engines. For in-space maneuvering, many different types of rocket are used, but even exotic ones like ion drives need fuel. The only space drive that doesn’t involve hauling fuel and complex systems into orbit is a solar sail. And Mustafa’s invention can, rudimentarily, be compared to a solar sail…because it doesn’t need “fuel” as such, and exerts just the tiniest push compared to the thundery flames of SpaceX’s rockets. It’s potential is enormous—because of its mechanical simplicity and reliability it could make satellite propulsion lighter, cheaper, and thus indirectly lower the cost of space missions of all sorts.
And if you want proof that the tiniest of pushes can propel a spacecraft, check this out: Two Pioneer space probes, launched in the 1970s, are the farthest manmade objects from Earth…but they’re not as far away as they should be. Over the course of a year they deviate by hundreds of kilometers from where all our science says they must be in orbit, and it’s been found that it’s down to the tiniest of pushes coming from radiators on-board that radiate heatwaves out slghtly more in one direction than another.
Aisha’s invention is so promising that her university’s staff aided with a patent application. She intends to study the design further in the hope of testing it out for real in space, but as theOnIslam.net site points out she notes that there’s no funding for a department of space science and this prevents important research being carried out in strife-ridden Egypt.
12 A star-gazer has come a little bit closer to the final frontier - after spending 18 months photographing the night sky.
With just an ordinary digital camera, Alex Cherney turned thousands of snaps into an incredible time-lapse video of the cosmos.
Using long exposures to allow more light in, these breath-taking pictures from the southern tip of Australia demonstrate how he captured the dramatic way the sky changes at night.
(via abcstarstuff)
Dopamine has been recognized as an important modulator of central as well as peripheral physiologic functions in both humans and animals. Dopamine receptors have been identified in a number of organs and tissues, which include several regions within the central nervous system, sympathetic ganglia and postganglionic nerve terminals, various vascular beds, the heart, the gastrointestinal tract, and the kidney. The peripheral dopamine receptors influence cardiovascular and renal function by decreasing afterload and vascular resistance and promoting sodium excretion. Within the kidney, dopamine receptors are present along the nephron, with highest density on proximal tubule epithelial cells. It has been reported that there is a defective dopamine receptor, especially D1 receptor function, in the proximal tubule of various animal models of hypertension as well as in humans with essential hypertension. Recent reports have revealed the site of and the molecular mechanisms responsible for the defect in D1 receptors in hypertension. Moreover, recent studies have also demonstrated that the disruption of various dopamine receptor subtypes and their function produces hypertension in rodents. In this review, we present evidence that dopamine and dopamine receptors play an important role in regulating renal sodium excretion and that defective renal dopamine production and/or dopamine receptor function may contribute to the development of various forms of hypertension.
Since the discovery in 1964 that dopamine produces natriuresis and diuresis (12), a tremendous amount of progress has been made in understanding dopamine-mediated effects on renal and cardiovascular function
Dopamine Deficiency in Human Hypertension.
Deficiency in renal dopamine synthesis and/or secretion has been reported in various forms of human hypertension. Urinary dopamine excretion is lower in salt-sensitive hypertensive patients than in normal subjects or non-salt-sensitive patients on high sodium intake . Suppressed dopaminergic activity has also been shown in the prehypertensive stage of primary hypertension . Reduced dopaminergic activity has also been observed in young normotensive subjects with an apparent family history of hypertension before any evidence of hypertension emerged . The exact mechanism for the renal dopaminergic deficiency in the human primary hypertension is not known. However, a defect in L-dopa-decarboxylase, the enzyme that catalyzes the conversion of L-dopa to dopamine, has been reported in a subject with a family history of hypertension . Other studies have shown a decrease in both the renal tubular uptake of L-dopa and the conversion of L-dopa to dopamine in a subgroup of salt-sensitive hypertensive patients . Because the suppression of renal dopaminergic activity has been observed in young normotensives with a family history of hypertension before any manifestation of the disease, it has been suggested that renal dopaminergic deficiency may contribute to the development of hypertension
Neuroscience: Synchronized Brains: Feeling Strong Emotions Makes People's Brains 'Tick Together'
ScienceDaily (May 24, 2012) — Experiencing strong emotions synchronizes brain activity across individuals, a research team at Aalto University and Turku PET Centre in Finland has revealed.
Experiencing strong emotions synchronizes brain activity across individuals. (Credit: Image courtesy…
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(Source: wolf-teeth, via wendyard)
Riding the Subway with Stanley Kubrick
As most New Yorkers know, the subway system is the lifeline of New York City. In 1946 Stanley Kubrick set out as a staff photographer for LOOK Magazine to capture the story of New York City’s subway commuters.
(Source: tobwaylan, via leopoldgursky)
