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How Green Fluorescent Proteins Bioluminesce: “
Berkeley researchers have identified the mechanism that makes green fluorescent protein (GFP) light up the way it does. They used femtosecond lasers to image the molecules as they undergo structural changes that cause them to fluoresce.
The transfer of a positively-charged hydrogen atom – a bare proton – along a reaction chain in GFP generates a green flash of light. The laser snapshots show that when the light absorber, or chromophore, nestled in the middle of the protein barrel absorbs an incoming photon of blue light, it starts vibrating, and the electrons start sloshing around the chromophore until it is aligned just right for the proton to hop via a water molecule to a nearby amino acid in the protein. From there, it continues down the reaction chain, creating a state with a negatively charged chromophore that emits green light.
Previous studies had shown that after the chromophore absorbs blue light, it undergoes proton transfer, and green light is emitted. In the current study, Mathies, Fang and their colleagues could actually resolve the early stage of this proton transfer reaction, taking snapshots of the vibrational wagging of the chromophore skeleton in sync with the electron cloud in the chromophore sloshing back and forth. However, the wagging oscillation might have stopped after a few picoseconds, when the chromophore and its vicinity are aligned just right for the proton to hop off down the reaction chain, and the whole protein shines bright green – which it does in its own good time, in about 3 nanoseconds.
Femtosecond stimulated Raman spectroscopy on GFP involves hitting the protein molecule with an approximately 80 femtosecond pulse of ultraviolet light, which excites many vibrational modes in the molecule, and then a one-two punch of picosecond red and femtosecond white light to stimulate Raman emission. The spectrum of emitted signals tells researchers the vibrational modes of various parts of the molecule. If the molecule is in the middle of a reaction, the emitted light at different time delays tells the researcher the various steps the molecule goes through during the reaction.
Berkeley Lab press release: Vibrations key to efficiency of green fluorescent protein …
Abstract in Nature: Mapping GFP structure evolution during proton transfer with femtosecond Raman spectroscopy
(Via Medgadget.)
2 Online Guides to Check Your Illness Symptoms Online: “
There are times when we want to check certain illness symptoms we or our loved ones are experiencing. We may not be sure if the symptoms warrant further investigation or we might just want to satisfy our curiosity about health and fitness in general.
In this article, let us look at two online guides to check your illness symptoms online, which are extremely easy to use and provide information about probable causes.
Before we proceed, it is necessary to stress that these guides should not be used as a substitute for professional medical advice. It is better that you use these tools as a supplementary resource to get more information, while you may be waiting for your doctor’s appointment, or to learn more about certain illnesses.
Check Symptoms Online With WebMD Symptom Checker
Web MD Symptom Checker is an easy to use interactive tool, where you select specific symptoms and it identifies possible causes.
You start by selecting your gender and age, after which you can specify the symptoms in three ways in the left panel:
- You can identify the symptom by zooming in on the affected body part in the interactive map of the human body on the left.
- You can select from a list of 76 possible symptoms organized in an alphabetical list and a common symptoms list.
- You can search for symptoms using the search box.
If applicable, you can select and add more symptoms. Once you identify the symptoms, the Symptom Checker shows you a list of possible conditions that may be the cause of them. You can check more about any possible condition right within the Symptom Checker.
For each condition, Symptom Checker provides you with an overview, a list of all symptoms associated with that condition, and related articles and videos on the WebMD website.
Mayo Clinic Symptom Checker
Use this guide to discover the most common causes of the most common symptoms. The Mayo Clinic Symptom Checker takes a different approach to isolating possible conditions than the WebMD version.
You first select between Adult and Child symptoms on the first page. For Adults, there are 28 common symptoms listed. After you choose one kind of symptom, the next page lets you select related factors depending upon the selected symptom:
- Details such as persistent/intermittent, started suddenly/gradually, etc.
- Whether it affects both pairs of hands/legs/etc.
- Details of the pain – duration, pattern, severity, location
- Trigger factors such as injury, repetitive use, stress, change in sleeping pattern, etc.
- Relieving factors such as medication, rest
- Accompanying symptoms associated with the selected symptom
Note that this page is specific and different for each of the 28 symptoms listed in the first page. The questions on this page are similar to what a doctor would ask you after you tell him about a symptom. So the process actually feels similar to an actual diagnosis!
After you make the appropriate selections on this page, the next one gives you possible causes of the symptoms. Here, you can see all associated factors or symptoms related to this condition.
Clicking on the condition takes you to the main page for it on the Mayo Clinic website. Here, you will find a wealth of information and resources such as description, causes, risk factors, tests and diagnosis, treatment and drugs, home and alternative remedies, prevention, etc.
For more health-related articles, check out our health category.
Did you find these tools useful? Any other online illness guide that you prefer? Tell us in the comments!
Did you like the post? Please do share your thoughts in the comments section!
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(Via MakeUseOf.com.)
Hubble’s New Camera Delivers Another Stunner: “
The Hubble Space Telescope’s new camera is returning incredibly detailed, stunning images of space. This close-up view of an area near the core of the iconic Southern Pinwheel galaxy, or M83, shows very rapid star birth.
The image to the right of the entire galaxy, taken from the ground by the European Southern Observatory’s 2.2-meter telescope at La Silla, Chile, shows the location of the image above. Hubble’s detailed view reveals that the spiral arms of the galaxy, about 15 million light-years from Earth, are lousy with clusters of infant stars, only a few million years old. The clusters show up as red because of the hydrogen gas they emit, and they have blown holes in the brownish dust tracks of the arms.
The image also reveals around 60 supernova remnants, around five times more than had previously been seen. the different wavelengths of light captured by Hubble’s camera, from ultraviolet to near-infrared, gives scientists a look at stars in all stages of formation, which will help them understand the evolution of the Pinwheel galaxy, and give them insight into galaxy formation in general.
Images: 1) NASA, ESA, STScI/AURA. High-Def Version. 2) ESO.
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(Via Wired Science.)
How many people did the man-eating lions of Tsavo actually eat? [Not Exactly Rocket Science]: “
In 1898, railway workers in Tsavo, Kenya were terrorised by a pair of man-eating lions, who killed at least 28 people during a 10-month reign of terror. It ended in December when a British officer called Lt. Col. John H. Patterson killed both beasts. The man-eaters’ notorious exploits have been immortalised in no less than three Hollywood films, including most recently The Ghost and the Darkness. But despite their fame, no one is quite sure how many people they killed. The Ugandan Railway Company said 28; Patterson claimed it was 135.
Both parties had reasons to lie, either playing down or exaggerating the figures for the sake of reputation. But Justin Yeake from the University of California decided to find the truth by going straight to the source – the remains of the man-eaters, currently on display in Chicago’s Field Museum of Natural History. By studying the chemical composition of the lions’ hair and bones, Yeake estimated that they killed around 35 people, with a possible range of 4 to 72. Either way, Patterson’s claim was wildly exaggerated.
The Tsavo man-eaters at the Chicago Field Museum, taken by Jeffrey Jung
Yeake took samples of the lions’ bone collagen and hair keratin, and measured the ratio of carbon and nitrogen isotopes. Both can tell you about the items on a lion’s menu – bone collagen grows slowly and reflects the lion’s lifetime eating habits, while keratin from fast-growing hairs reveals the nature of its meals over the past three months.
Yeake compared these ratios to those of modern Tsavo lions, and matched them against those form various prey animals including giraffe, kudu, impala, zebra, buffalo and humans. The human samples came from remains collected by anthropologist Louis Leakey during his East African Archaeological Expedition of 1929.
The results showed that the diet of Tsavo’s modern lions consists almost entirely of grazing animals such as zebra, waterbuck and buffalo. The man-eaters were different. Yeake calculated that one of them probably ate around 11 people in its nine-month hunting spree, but focused mainly on expanding its tastes in herbivores.
His partner switched menus even more dramatically, moving to a diet of browsers (giraffe, kudu and the like) and humans. By winter, a third of his food came from freshly killed humans. This was the animal that caused the lion’s share of deaths among the railway workers, and Yeake estimates that he ate around 24, giving a total kill count of 35. Of course, these are only estimates, but there’s a 95% chance that the true figure falls within the range of 4-72.
These disparate diets make the cooperation between the two males even more astounding. Both specialised on different rare prey and, if anything, their tastes diverged even further from one another over time. And yet, they frequently exposed themselves to danger to kill animals that only one ate. That sort of behaviour had never been seen before or since. Perhaps by working together, they could scatter both humans and game, so that both could be fed? For the moment, we just don’t know.
Nor is it clear why the lions starting eating people in the first place, although Yeake has two theories. For a start, the lion that killed the most people had severe injuries, including diseases of the skull and teeth, skull evinced craniodental, poorly aligned jaws and a fractured tooth. It wasn’t exactly a king among beasts, and it supports the idea that big cats are more likely to prey on humans if they’re ill or impaired.
The Tsavo killings took place against a backdrop of intense environmental changes. Elephant populations had plummeted and as a result, woodlands were expanding and the savannah’s grazers were being driven away. The remaining herds were thinned by a 13-year drought and a pair of viral epidemics in 1889 and 1898. And just as these walking sirloins dwindled away and the lions started to hunger, a new type of prey arrived in the region – humans, charged with building the Uganda Railway. The rest is history.
The two lions, Lieutenant Patterson (in top-left) and a Taita ancestral shrine.
Reference: PNAS: doi:10.1073/pnas.0905309106
La Brancaia Il Blu 2006: “La Brancaia Il Blu 2006
La Brancaia Il Blu 2006 is one of the best Super Tuscan wines around and with a growing reputation it won’t stay on my QPR doozy list for long. The 2006 vintage is sumptuous. A fantastic year for Merlot in Italy, that supple little grape has provided the knock out punch to the other great red of La Brancaia’s, Ilatraia. Usually, vintage after vintage these two wines can barely be separated both excellent though with very different flavour profiles. However, this year Il Blu is a baby giraffes neck ahead and with 96 points from Galloni and a Tre Bicchiere award, I had to get hold of this years vintage and see if the wine justified this stonking rating.
Swiss owned La Brancaia are foremostly fine exponents of Chianti Classico, and, like many other Tuscan estates with Chianti holdings, soon turned their attention to the cheaper and Bordeaux-esque Maremma to begin producing Super Tuscan wines. Still today these wines are wowing the critics. A little out of fashion in the noughties those in the know still swear by the Super Tuscan often rivalling, sometimes surpassing, the quality of Bordeaux and often for a fraction of the price. The interesting thing about Il Blu, a 50% Sangiovese, 45% Merlot and 5% Cabernet Sauvignon wine is that it’s not actually from Maremma but grown within the Chianti jurisdiction.
The excellent thing about it, is that this wine can still be found for under £40. 96 Point wines at £40 are very few and far between especially from such a famous region. Although I wasn’t quite as impressed, to me 96 represents a unique barrier to push through, I happily award this wine 95 Points and a rubber stamped BUY.
As frequent readers of this blog will know, I spent 3 of the last 4 years living in Italy and one of the most beautiful things about it, excluding the people, countryside, food and wine, was the way these 4 qualities were often married. We spent many Friday evenings drinking and eating at the local Agriturismo’s, where you ate the produce from the working farms, many of these were not just farms and restaurants but also hotels too. At La Brancaia you can also take a vacation with a stunning location, great food and wine of course, and set yourself right in the heart of a gorgeous Italian wine holiday. Check it out here.
Back to the wine. I popped and poured the La Brancaia Il Blu 2006 on Sunday which, to be honest, was a good 5 years too early. The wines of La Brancaia, apart from the Chianti Classico which is surprisingly accessible young, should all be given at least 5 years in the cellar. Despite this it was very clear to see that this was a very special wine and after some time to breath I can say that, for 2009 so far, this is the best QPR wine of the year. If you love Italian wines you have to seek this out, if you are into Bordeaux you have to seek this out, if you collect wine to sell for profit… you have to seek this out. If an alien were to come down from Mars, point a gun to my head and forced me to choose just one wine to attempt to please his palate…I’d choose this wine.
Food Match: Duck, Pigeon or Venison.
Best Wines from this Producer: Consistently excellent within their varietal.
Chianti Classico
Brancia Il Blu
Tre
Ilatraia
La Brancaia Il Blu 2006 – BUY – £39
Deep dark ruby red edging on purple, the wine sits thick in the glass. On the nose you are taken on a power tour of fruit with cherries, plum and spicy vanilla oak. The wine is full bodied with the aromas carrying through to the attack. The mid palate is powerful and tannic at the moment but still enjoyable with the finish almost endless. Brilliantly structured, the wine hides the alcohol brilliantly and is sure to improve with age. 95 Points
Where can I buy this wine?
Europeans – Chicago WC – $47.50
Americans – Divine Golosita Toscane – €40
Brits – WineDirect – £39
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Which wine would you give to an alien to showcase the best planet earth had to offer?
Italian Wine Blog – Wine90
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(Via Italian Wine Blog – Wine90.)
Mary’s Monday Metazoan: Mighty Moose [Pharyngula]: “
Reader Lindsay sent along this pair of photos of a moose taking a stroll along a dirt road near Elliot Lake, near Sault Ste. Marie in Michigan ‘s Upper Peninsula.
That’s not a footpath, by the way. It’s a single lane dirt road for cars, just to give some sense of how big this beast is.
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