Sunday, December 30, 2007
Friday, December 14, 2007
RSC: Scientists trap light in nano-soup
See this page from the Royal Society of Chemistry website:
Scientists trap light in nano-soup - http://www.rsc.org/chemistryworld/News/2007/December/10120701.asp
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Can light be stopped and trapped ? read on...
Thursday, December 13, 2007
Tuesday, December 11, 2007
Fwd: HUMANS CARRY MORE BACTERIAL CELLS THAN HUMAN ONES (fwd)
Subject: HUMANS CARRY MORE BACTERIAL CELLS THAN HUMAN ONES
Humans Carry More Bacterial Cells than Human Ones
You are more bacteria than you are you, according
to the latest body census
By Melinda Wenner
Scientific American
We compulsively wash our hands, spray our countertops and
grimace when someone sneezes near us-in fact, we do
everything we can to avoid unnecessary encounters with the
germ world. But the truth is we are practically walking
petri dishes, rife with bacterial colonies from our skin to
the deepest recesses of our guts.
All the bacteria living inside you would fill a half-gallon
jug; there are 10 times more bacterial cells in your body
than human cells, according to Carolyn Bohach, a
microbiologist at the University of Idaho (U.I .), along
with other estimates from scientific studies. (Despite
their vast numbers, bacteria don't take up that much space
because bacteria are far smaller than human cells.)
Although that sounds pretty gross, it's actually a very
good thing.
The infestation begins at birth: Babies ingest mouthfuls of
bacteria during birthing and pick up plenty more from their
mother's skin and milk-during breast-feeding, the mammary
glands become colonized with bacteria. "Our interaction
with our mother is the biggest burst of microbes that we
get," says Gary Huffnagle, a microbiologist and internist
at the University of Michigan at Ann Arbor. And that's just
for starters: Throughout our lives, we consume bacteria in
our food and water "and who knows where else," Huffnagle
says.
Starting in the mouth, nose or other orifices, these
microbes travel through the esophagus, stomach and / or
intestines-locations where most of them set up camp.
Although there are estimated to be more than 500 species
living at any one time in an adult intestine, the majority
belong to two phyla, the Firmicutes (which include
Streptococcus, Clostridium and Staphylococcus), and the
Bacteroidetes (which include Flavobacterium).
For a long time, scientists assumed that these bacteria,
despite their numbers, neither did us much harm nor much
good. But in the past decade or so, researchers have
changed their tune.
For one thing, bacteria produce chemicals that help us
harness energy and nutrients from our food, Huffnagle
explains. Germ-free rodents have to consume nearly a third
more calories than normal rodents to maintain their body
weight, and when the same animals were later given a dose
of bacteria, their body fat levels spiked, even if they
didn't eat any more than they had before.
Intestinal bacteria also appear to keep our immune systems
healthy. Several studies suggest that microbes regulate the
population and density of intestinal immune cells by aiding
in the development of gut-associated lymphoid tissues that
mediate a variety of immune functions.
The bacteria also appear to influence the function of
immune cells like dendritic cells, T cells and B cells,
although scientists don't know the precise mechanisms yet.
And one chemical released by the bacterium Bacteroides
fragilis is capable of directing how the developing immune
system matures.
Further, probiotics-dietary supplements containing
potentially beneficial microbes-have been shown to boost
immunity. Not only do gut bacteria "help protect against
other disease-causing bacteria that might come from your
food and water," Huffnagle says, "they truly represent
another arm of the immune system."
Of course, they can't protect against every onslaught,
which is why we still have to depend on antibiotics to rid
us of some disease-causing infections. But antibiotics
don't just kill off the "bad" microbes, they wipe out the
"good" ones, too. That's why antibiotic use can cause
diarrhea and upset stomach: The drugs interfere with the
balance of our bacterial flora, making us sick, Huffnagle
explains.
But the bacterial body has made another contribution to our
humanity-genes. Soon after the Human Genome Project
published its preliminary results in 2001, a group of
scientists announced that a handful of human genes-the
consensus today is around 40-appear to be bacterial in
origin.
The question that remains, however, is how exactly they got
there. Some scientists argue that the genes must have been
transferred to humans from bacteria fairly recently in
evolutionary history, because the genes aren't found in our
closest animal ancestors. Others argue that they may be
ancient relics from evolutionary events that took place
early in our species's history and, for reasons unknown,
the genes were lost in these ancestors. It's impossible to
know for sure at this point.
"There remain to my knowledge no clear cases of human genes
recently acquired from bacteria," says Cédric Feschotte, a
biologist at the University of Texas at Arlington. "It
doesn't mean there are none, but they are not well
documented."
One thing is for sure: our lives and even our identities
are more closely linked to the microbial world than we may
think. Bacteria do a lot to keep us healthy, and scientists
are just beginning to uncover their valuable secrets. As
U.I.'s Bohach says: "We do not completely understand the
full impact of our bacterial flora on our health and
physiology."
More at:
http://www.sciam.com/article.cfm?id=strange-but-true-humans-carry-more-bacterial-cells-than-human-ones&sc=WR_20071204
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Thursday, December 6, 2007
Can a turtle breathe through its bottom?
Text message trivia: Answers in minutes
In three years, the trivia experts at Any Question Answered have tackled nine million queries sent in by mobile phone. So what exactly have they learnt? Well, where shall we begin?
Published: 28 November 2007
In three years, the trivia experts at Any Question Answered have tackled nine million queries sent in by mobile phone. So what exactly have they learnt? Well, where shall we begin?
Published: 28 November 2007
It's a simple idea: send a question via text message to 63336, and one of 1,000 researchers will text you the answer in minutes. That's the simple idea behind AQA (or Any Question Answered, to give it its full title). The service launched three years ago and now its crack trivia team answers 16,000 questions a day, including these. And yes, someone really did
send in each and every one...
How come mother hedgehogs aren't stabbed during labour?
Baby hedgehogs are born with very soft, pliable spikes, which are aligned to allow easy birth. These quickly harden to provide protection for the hoglet.
What creature in the animal kingdom has the biggest heart in relation to
the size of its body?
The hummingbird has the biggest heart of all, for the size of the animal.
In flight, it pumps 1,000 times a minute so it can hover like a helicopter.
What country has killed the most extinct animals?
The World Conservation Union (IUCN) documents 784 extinctions since
AD1500 (when historical scientific records began). Mauritius has lost the most
(44), followed by Australia (35).
Are there more cows than cars in the world?
Yes, there are more cows in the world than cars: an estimated 1.4 billion
cows compared to about 1 billion cars. Cows produce 20 per cent of all
methane.
Can a turtle breathe through its bottom?
Yes. Many species of turtle have special sacs opening off the cloaca
(anal chamber) permitting take-up of oxygen. Sea-cucumbers also "buttbreathe".
Do cats dream?
Most mammals dream, including cats. Dreaming helps brains to grow, by
exciting the neurons. Newborn babies dream about eight hours per day.
Are sheep more tolerant of loud noise from music festivals than, say,
cows and horses?
Sheep appear to acclimatise to noise more easily than other animals.
This has been tested through their body and behavioural responses to aircraft
noise.
What is the biggest living thing?
The biggest living thing in the world is an underground honey mushroom fungus in Oregon, USA. The entire organism covers 890 hectares b - almost 1,665 football pitches.
How old was the oldest goldfish?
The oldest known goldfish was Goldie, and was owned by Pauline Evans of Devon. Goldie lived for 45 years after being won in 1960 at a fairground.
Who would win in a fight between a sperm whale and a giant squid?
A sperm whale would have a giant squid for breakfast bSarnath
literally. Giant squid form 80 per cent of its diet; the rest
being octopus, fish, shrimp, crab and shark.
What is the smallest bird in the world?
The world's smallest bird is the Cuban zunzun (Mellisuga helenae).
Also known as a bee hummingbird, it measures a mere 6cm in length
and is the weight of four paperclips.
How do bats give birth?
Baby bats (called "pups") are born upside down and are caught by
their mother's wings. They hang on to the mother bat's nipples
using hooked milk teeth.
What is the speed of acceleration of a chameleon's tongue?
The chameleon's tongue whips out faster than the eye can follow,
speeding at 26 body lengths per second. It hits the prey in about
0.03 seconds.
From what animal does injected insulin come?
Insulin is now manufactured for widespread clinical use using
genetic engineering techniques. In the past it has come from cows,
horses, pigs and fish.
Who has the world's biggest TV set?
The biggest television in the world is owned by the Japan Racing
Association. The new Mitsubishi Diamond Vision HD LED display is
over 8,000 square feet.
How many oranges would need to be placed end to end to make it to
the Moon?
The Earth is 238,900 miles from the Moon. You would need 13,411
oranges to cover a mile, so to the Moon you would need
3,203,935,680 oranges balanced end to end.
Why does alcohol make you drunk?
Alcohol makes you drunk because it slows the function of the brain
and increases the release of the neurotransmitter dopamine, which
is related to pleasure.
In which town or city in the UK do people have the highest life
expectancy, and what is that age?
The London borough of Kensington & Chelsea, at 80.8 years (men) and
85.8 (women), has the highest life expectancy. Glasgow, at 69.3 and
76.4 years, has the lowest.
What is the world's oldest tree?
At more than 4,800 years old, the oldest living tree is "Methu-selah" , a bristlecone pine in the White Mountains, California. Its exact location is a secret.
How much does an elephant poo in its life?
An elephant would produce around 2,492,000kg of excrement over its
lifetime. On an average day, the average elephant produces around
100kg. For a human, the daily amount is around 250g.
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