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Sensor to detect early tumours

2012-12-28T23:32:00.000+07:00

Researchers at Swinburne are developing a leading-edge sensor that will help detect and diagnose cancers early, potentially saving many more lives.

The new technology is the vision of PhD researcher Emma Carland. Inspired by her experience helping sick children in intensive care at The Royal Children’s Hospital in Melbourne, Emma decided to use her biomedical engineering skills to give people a better chance against illnesses.

“I maintained and tested life-support medical equipment such as drug pumps and respirators, and saw how the kids rely on these tools in their day-to-day struggle for life,” Carland says. “This was a powerful motivation for me to embark on this research.”

Her work is based on an optical-fibre touch sensor as fine as a human hair built by her supervisors, Dr Paul Stoddart and Dr Scott Wade, last year to prevent injuring delicate ear tissues during cochlear implant insertion.

The sensor is built into an optical fibre – a technology that has revolutionised communications – that sends light between its two ends. Due to its tiny size and fast transmission of signals, optical fibres are often used in medicine, including endoscopies and ‘keyhole’ surgeries.

“In our touch sensor, light either passes through or is reflected by two sets of parallel ‘lines’, or gratings, in the fibre,” says Dr Stoddart, who is an associate professor in biomedical engineering and also involved in Swinburne’s bionic-eye project.

“When the sensor is untouched, the light that reflects from the first grating matches the second one, resulting in a ‘low’ signal.

“When you apply pressure to the sensor, the light reflected by the first grating will shift, and now that it no longer matches the second grating, the detector picks this up and emits a ‘high’ signal. The difference between these two signals will tell you how much pressure the sensor experiences.”

Now, the researchers propose to use the device for early detection of tumours by vibrating the sensor against a particular tissue: as the sensor nudges and withdraws from the area, the detected signals will alternate between being either high or low.

“A tumour is stiffer than cells from a healthy area,” says Emma. “So, the difference between the sensor’s signals tells you how stiff the tissue is – a diseased tissue, being firmer, will push back at the sensor with more force, resulting in a larger difference.”

Dr Stoddart continues, “Once we test the tissues at different vibrating frequencies, we can find out that at this particular frequency, for a healthy tissue, the signal should be at this range. Larger signal differences mean the tissue is firmer and indicate that they’re more cancerous.

“This allows us to make an accurate assessment of the tumour’s stage – and the best way to treat it. This is something many tumour tests can’t provide, as they only tell you whether the tissue is diseased or not. We can then build a database with the information and embed it into software,” he says.

The long, thin and flexible structure of the fibre sensor will also allow it to be inserted into endoscopes that explore small tissue regions, such as ear, nose, throat cavities and the colon.

“Endoscopies usually take tissue samples and send them to the laboratory for analysis, which could take a while,” Dr Stoddart says. “With the sensor, we can judge the area to see how the tissues respond, which gives us quicker results.

“This means we can obtain very precise measurements of small tissue regions, which allows for the early identification of any abnormal tissues.”

Via: http://www.sciencealert.com/news/20121012-23905.html

Android-Based Network Built to Study Cyber Disruptions and Help Secure Hand-Held Devices

2012-12-21T14:32:00.001+07:00

Sandia cyber researchers linked together 300,000 virtual hand-held computing devices running the Android operating system so they can study large networks of smartphones and find ways to make them more reliable and secure. Android dominates the smartphone industry and runs on a range of computing gadgets.

The work is expected to result in a software tool that will allow others in the cyber research community to model similar environments and study the behaviors of smartphone networks. Ultimately, the tool will enable the computing industry to better protect hand-held devices from malicious intent. The project builds on the success of earlier work in which Sandia focused on virtual Linux and Windows desktop systems.

"Smartphones are now ubiquitous and used as general-purpose computing devices as much as desktop or laptop computers," said Sandia's David Fritz. "But even though they are easy targets, no one appears to be studying them at the scale we're attempting."

The Android project, dubbed MegaDroid, is expected to help researchers at Sandia and elsewhere who struggle to understand large scale networks. Soon, Sandia expects to complete a sophisticated demonstration of the MegaDroid project that could be presented to potential industry or government collaborators.

The virtual Android network at Sandia, said computer scientist John Floren, is carefully insulated from other networks at the Labs and the outside world, but can be built up into a realistic computing environment. That environment might include a full domain name service (DNS), an Internet relay chat (IRC) server, a web server and multiple subnets.

A key element of the Android project, Floren said, is a "spoof" Global Positioning System (GPS). He and his colleagues created simulated GPS data of a smartphone user in an urban environment, an important experiment since smartphones and such key features as Bluetooth and Wi-Fi capabilities are highly location-dependent and thus could easily be controlled and manipulated by rogue actors.

The researchers then fed that data into the GPS input of an Android virtual machine. Software on the virtual machine treats the location data as indistinguishable from real GPS data, which offers researchers a much richer and more accurate emulation environment from which to analyze and study what hackers can do to smartphone networks, Floren said.

This latest development by Sandia cyber researchers represents a significant steppingstone for those hoping to understand and limit the damage from network disruptions due to glitches in software or protocols, natural disasters, acts of terrorism, or other causes. These disruptions can cause significant economic and other losses for individual consumers, companies and governments.

"You can't defend against something you don't understand," Floren said. The larger the scale the better, he said, since more computer nodes offer more data for researchers to observe and study. The research builds upon the Megatux project that started in 2009, in which Sandia scientists ran a million virtual Linux machines, and on a later project that focused on the Windows operating system, called MegaWin. Sandia researchers created those virtual networks at large scale using real Linux and Windows instances in virtual machines.

The main challenge in studying Android-based machines, the researchers say, is the sheer complexity of the software. Google, which developed the Android operating system, wrote some 14 million lines of code into the software, and the system runs on top of a Linux kernel, which more than doubles the amount of code. "It's possible for something to go wrong on the scale of a big wireless network because of a coding mistake in an operating system or an application, and it's very hard to diagnose and fix," said Fritz. "You can't possibly read through 15 million lines of code and understand every possible interaction between all these devices and the network." Much of Sandia's work on virtual computing environments will soon be available for other cyber researchers via open source. Floren and Fritz believe Sandia should continue to work on tools that industry leaders and developers can use to better diagnose and fix problems in computer networks.
"Tools are only useful if they're used," said Fritz. MegaDroid primarily will be useful as a tool to ferret out problems that would manifest themselves when large numbers of smartphones interact, said Keith Vanderveen, manager of Sandia's Scalable and Secure Systems Research department. "You could also extend the technology to other platforms besides Android," said Vanderveen. "Apple's iOS, for instance, could take advantage of our body of knowledge and the toolkit we're developing." He said Sandia also plans to use MegaDroid to explore issues of data protection and data leakage, which he said concern government agencies such as the departments of Defense and Homeland Security.

Original Story: http://www.sciencedaily.com/releases/2012/10/121002091753.htm

Some tips to Memorize Fast and Remember More

2012-08-11T23:15:00.000+07:00

You will be able to remember names, facts, dates, history, story lines, outlines, speeches, and more.

You memorize fast and remember more just follow some tips below.

Connect it - make connections with what you already know to memorize fast.
See it - visualize the concept to memorize fast and remember more. Chant it - (Re) Produce the material out loud to memorize faster.
Write it - reproduce the material in writing to remember
Mock it - use catchy puns and phrases to memorize faster.

Top 10 Highly Effective Brain Foods that Improve Your Memory

2011-12-13T13:16:00.000+07:00

Hi all friends, now I want to show you about the foods that improve our memory. All of this so YUMMY...

There are...

1. Blueberries—Blueberries serve a wide range of functions for improving mental function. Most notably, regular blueberry consumption has been shown to improve memory function. Furthermore, blueberries are rich in antioxidants, helping to prevent free radical damage. Still not convinced? Research has found that blueberries can also reverse age related declines in motor function, balance, and coordination.
2. Salmon—Rich in Omega-3 fatty acids, salmon helps your brain develop tissue for increasing your brain power. Furthermore, salmon also plays a key role in fighting Alzheimer’s and other age-related cognitive disorders.
3. Flax seeds—Flax seeds are crammed with ALA- a healthy fat that aids the cerebral cortex in functioning better. This is the portion of the brain responsible for processing sensory information. Keeping it sharp is vital.
4. Coffee—Regular coffee drinking has been shown to reduce the risk of Alzheimer’s, Dementia, and other mental disorders. That’s because caffeine is good for the brain (in moderation), and it contains antioxidants. The important thing to note is you shouldn’t add in all the other junk to your coffee (the ridiculous Starbucks drinks crammed with sweeteners and fatty products).
5. Mixed nuts—Peanuts, walnuts, pecans, and other nuts contain properties that help with everything from fighting insomnia to promoting mental clarity and strong memory. Walnuts are rich in Omega-3 fatty acids while almonds contain natural mood-enhancing neurotransmitters.
6. Avocados—Don’t let the avocado’s fat content fool you. It’s a healthy fat that promotes blood flow, keeping your mind functioning at its peak. That’s not all: Avocados have also been shown to reduce blood pressure.
7. Eggs—Egg yolks are rich in choline, an essential nutrient to improving memory function.
8. Whole grains—From oatmeal to whole grain bread, whole grains are excellent brain foods as they improve circulation and contain essential fibers, vitamins, and even some Omega-3. Just make your sandwiches from whole grain breads to enjoy the benefits.
9. Chocolate—Dark chocolate is antioxidant-rich, and it also improves focus and concentration. Milk chocolate, on the other hand, improves memory and reaction time.
10. Broccoli—Broccoli has been shown to improve memory function as well as slow the aging process. This means a broccoli-rich diet will keep you young and sharp.

Now I would like invite you to eat together.
YUMMY!

Source: Health Journal

Beginning Programming with C++ For Dummies 2010

2011-12-07T10:20:00.001+07:00

Beginning Programming with C++ For Dummies by Stephen R. Davis

Publisher: For Dummies | 2010 | ISBN 0470617977 | PDF | 456 pages | 15 MB

An ideal starting point to get a strong grasp of the fundamentals of C++
C++ is an object-oriented programming language commonly adopted by would-be programmers. This book explores the basic development concepts and techniques of C++ and explains the "how" and "why" of C++ programming from the ground up.

You'll discover what goes into creating a program, as well as how to put the various pieces together, deal with standard programming challenges, handle debugging, and make it all work.
* Details the basics of C++ programming and explores the "how" and "why" of this object-oriented language
* Addresses the various components that go into creating a program with C++
* Walks you through common challenges of C++ programming
Assuming no prior experience, Beginning Programming with C++ For Dummies is a fun and friendly guide to learning the C++ language.

55 Tips to Instantly Make Your Brain Stronger and Faster

2011-08-11T10:08:00.002+07:00

Hello friends...
We can do everything by our brain.
Do you want to have a strong brain? If you can think fast, well and remember everything quickly, you'll always on top...
Here are 55 tips that can make your brain stronger and faster:

Knowledge Boost

Increase your knowledge base, and continue learning. An interest in the world around you, and the never ending quest for knowledge, can actually boost your brain power. Here are some ways to experience a knowledge boost — and keep your brain strong:

Discover your learning style: In order to accumulate knowledge, you need to understand how you learn best. Figure out your learning style, and then use that knowledge to boost your brain power.
Rediscover the encyclopedia: You can get a great overview on a number of different subjects when you read an encyclopedia. Do it online or offline, but you can learn about something new each day when you read the encyclopedia.
Revisit tough school subjects: You can give your brain a workout when you revisit tough school subjects. Had a hard time with math? Go back and do a refresher online. Was English your Achilles heel? Review sentence diagramming.
Stay up to date: Know what’s happening in the news. Keep track of current events by watching the nightly news, reading the newspaper or looking online.
Look at things from the other side: If you have an opinion about a certain subject or issue, look at it from the other side. Learn the merits of the opposing opinion, and try to understand another point of view. This type of critical thinking will boost your knowledge base and your brain power.
Consider philosophy: There are few things that can give your brain a good workout like trying to answer philosophical questions like “What is truth?” and “Why are we here?”
Take community education classes: If possible, take a class in something you find interesting. You can audit a class at a university or enroll in community education. A great way to continue building knowledge and strengthening your brain.
Enjoy open courseware: Even if you can’t attend a class in the “real” world, you can do so online. Many universities offer open courseware that allows you to learn for free. MIT has especially expansive open courseware offerings.
Read scientific journals: Whether you read online or off, getting information from scientific journals and other publications can boost your knowledge and brain power.
Look for new experiences: Few things can increase your brain power like new experiences. Look to experience new things every so often.
Pay attention to your environment: The way your environment is arranged can help you focus better and absorb knowledge better. A tidy environment, and one that is cool, can actually help enhance your study skills.

Creative Boost

Creativity can help improve your brain function. Here are some tips for using creativity to build your brain’s strength and agility.

Explore your creative side: Try writing, art or performance to see whether you enjoy. You don’t even have to be good at it; just working at your creativity can help you increase your brain power and speed.
Read for fun: Don’t just read for knowledge; read for fun as well. Even if you enjoy reading novels, you can boost your brain power by working your imagination as you journey to new places using your mind.
Don’t forget to laugh: Laughing relieves stress and releases chemicals that help you feel positive. Humor can be a good way to release tension and let your brain get a little relaxation.
Learn a musical instrument: The learning processes that go into music can benefit you. Learn a musical instrument to increase your brain power and enhance personal enjoyment.
Listen to music: The creative processes in music can benefit you, even if you just listen. Classical music is especially beneficial for the brain.
Volunteer: Use your talents and skills to help others. Volunteering can be a good way to build brain power as you meet new people and learn new things.
Learn about other cultures: Understanding other cultures can be an interesting and creative exercise that can help you gain new perspective while making your brain stronger.
Keep a dream journal: A dream journal can encourage you to examine your subconscious, and you may find new answers in creative ways in your dreams.
Develop a hobby: Find something you enjoy doing and develop that skill through a hobby.
Interact with others: Socializing can be a to learn new ideas and share your own. Creative sharing — or just relaxing with others — can boost creativity and make your brain stronger.
Consider a child’s perspective: Look at things as a child would. This is a great creative exercise that can help make your brain stronger

Memory Tricks

If you want to improve your memory and make your brain faster at recall, here are some tricks you can practice:

Use an organizer: Organizing your thoughts and appointments can help you recall needed information faster.
Get adequate sleep: You remember things better when you are properly rested.
Use more senses: As you learn, focus on smell, taste and touch as well as sight and sound. This will help you with recall.
Linking: Link a new concept somehow to something you already know. This will help you organize the information in your brain.
Practice: Just like anything else, if you want a good memory, you have to practice. Practice recalling information you have learned.
Mind mapping: You can use mind mapping to learn how to visualize what you have you learned, and then recall it earlier.
Try to avoid distractions: Concentrate on what you are doing, and try to avoid distractions when possible.
Mnemonic devices: You can use a number of mnemonic devices to improve your memory function, including systems of letters, grouping and even rhymes.
Take notes: When learning something, take notes. Writing it down can help you commit things
Use your non-dominant hand: You can increase your brain power and your memory by exercising your brain with the use of your non-dominant hand.
Make a to-do list: Sometimes you need external reminders to help you keep your memory sharp. A to-do list can help you stay focused throughout the day.

Stay Sharp

Once you have begun building your brain power, you want to stay sharp. Here are some tips that can help you keep your brain strong and fast.

Physical exercise: You can enhance your brain function by staying physically active.
Meditation: You can sharpen your mind powers with some meditation. Give your brain a charge, and keep it focused.
Relaxation: De-stress yourself in order to give your brain time to process and rest a little. This will help it stay sharp and learn better in the future.
Sudoku: You can exercise your mind skills, and keep them sharp, with the number game Sudoku.
Crossword puzzles: Simple and fun crossword puzzles can help exercise your mind to keep it fast and sharp.
Trivia games: Played online or with a group of friends in person, trivia games can be great ways to exercise your memory and your brain.
Video games: Some video games are designed with education and brain function in mind. Games that require you to think things through and solve puzzles to advance can be helpful in maintaining your brain power.
Strategic board games: Games like chess, Risk and even checkers can help you analyze situations and think strategically, boosting your brain power.
Some card games: Some card games, like bridge, can keep your mind sharp by encouraging thought about strategy. Even poker can test your ability to determine probabilities.
Teach: One way you can keep your mind sharp is to teach others. You can teach as an adjunct, offer community classes or tutor in order to keep your mind sharp.
Learn sign language: Sign language connects motor skills to the brain, and brings more mental effort to communication.

Brain Food

If you want to boost your brain power and quickness, you need to eat the right things. There are some nutritional guidelines that can help you improve braing strength.

Omega-3 fatty acids: The oils found in fish and some plants, like flaxseed, can improve brain function.
Red wine: In very moderate amounts, red wine can help your brain.
Blueberries: These delicious berries can help neurons in your brain.
Strawberries: Antioxidants in strawberries can help your brain, and the vitamin C and potassium have other benefits.
Folic acid: This nutrient can help you avoid memory loss. Folic acid supplements can be a good addition to your brain food regimen.
Fiber: Keep your body and mind functioning properly and in balance with fiber.
Water: Dehydration can be detrimental to the brain. Drink lots of water to avoid this.
Eat breakfast: Get off to the right start every day with proper nutrition, and your brain will be more active.
Beware of caffeine: While moderate amounts of caffeine can be helpful (one cup of tea or coffee), too much can overstimulate the brain, and the following crash can cause problems.
Watch out for alcohol and drugs: Substance abuse is very detrimental to brain function.
Limit junk food: Junk food drains your brain power and slows it down. In order to make your brain stronger and faster, you need to limit your intake of junk.

iOS 5 beta 5 download lands on weekend, hints at iPad 3 release date

2011-08-11T09:08:00.000+07:00

Apple has served up the download of the fifth beta test version of its upcoming iOS 5 operating system to developers today, and for once, it arrives on a Saturday. The move bypasses the typical business-hours release schedule of the beta, and suggests that the arrival of the official finished iOS 5 for end-users of iPad, iPhone, and iPod touch devices is imminent. More than the mere fact that this beta 5, meaning that Apple and developers have put it through significant paces, the fact that this one pops up on Saturday points to the final release date being sooner than later. The “5″ number means little, as Apple could theoretically release as many beta versions as it wants or needs to; iOS 4.2 for instance went through so many paces that would-be waiters lost count. The key difference here is that once beta 5 was ready, Apple opted not to wait til Monday to post the download, even though it would only have meant holding it back another forty-eight hours. And that means the clock is ticking.

Apple’s procedure of launching new hardware (in this case the new iPhone, probably the iPod touch 5, and perhaps the iPad 3) with the brand-new version of iOS installed and also pushing the installable version of the new iOS out to existing users in the same week means that the timing of it all is tricky. iOS 5 must be ready to go at the same time as the new hardware. And while the latter is simply a matter of finalizing the design and getting enough units manufactured ahead of the designated release date, an operating system is a more fluid thing. iOS 5 is ready when Apple decides it’s ready, with super-late-stage beta testing often a luxury only afforded if there’s enough time before launch. Any obscure bugs not found in iOS 5 before release can be cleaned up in iOS 5.0.1 a week or two later, and any features which aren’t quite perfected enough to make it into iOS 5 can always be rolled into iOS 5.1 once they’re ready (look at how AirPlay and AirPrint were scaled back a bit in the iOS 4 era for the sake of getting that particular release out the door, for instance). But after releasing the first four betas in mozey mode, Apple is now suddenly in a rush with the fifth one. And that’s a good thing…

What it means is that somewhere along the Apple food chain, the signal has been given that the new hardware expected to debut alongside iOS 5 has been locked in for release date. Now, Apple’s software team is suddenly dealing with a finite timeframe for accomplishing whatever else it needs to before launch. As such, iOS 5 beta 5 has been pushed out out a weekend so Apple can get feedback from workaholic third party developers immediately rather than losing another two days simply for the sake of a tidier-sounding Monday release. And now the game is afoot, because the clock is ticking on the iOS 5 release date, which means the clock is also ticking for the iPhone 5, the iPod touch 5, the iPad 3 and/or whatever else Apple is planning to shove out the door that same week.

$999 iMac for education

2011-08-08T22:33:00.001+07:00

Apple has launched a lower cost $999 iMac for educational institutions. This is not available for individuals it's mean for education only.

The 21.5 inch model, with a 3.1GHz Intel Core i3 Dual-Core processor, AMD Radeon HD 6750 graphics with 512MB of memory, 2GB of RAM, a 250GB Hard Drive, a 'Superdrive', OSX Lion, and all the iLife stuff you get with any new Mac.

(See picture below)

Geometric Transformations II

2011-08-08T20:22:00.007+07:00

* Author: I. M. Yaglom * Publisher: Mathematical Association of America * Publish Date: 1968 * ISBN: 0883856212 * Pages: 189 New Mathematical Library This book is the sequel to Geometric Transformations I which appeared in this series in 1962. Part I treas length-preserving transformations, this volume treats shape-preserving transformations; and Part III treats affine and protective transformations. These classes of transformations play a fundamental role in the group-theoretic approach to geometry. As in the previous volume, the treatment is direct and simple. The introduction of each new idea is supplemented by problems whose solutions employ the idea just presented, and whose detailed solutions are given in the second half of the book.

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How to Make an Atomic Bomb

2011-08-07T19:12:00.000+07:00

Diagram of Nuclear bomb

We will look today at what you need in order to make a nuclear fission bomb. You need some money, as it would really help
if you were the prince, sultan or other royalty of a small, but rich state. If not, you need to know on a first name basis some evil leader with lots of cash, oil, diamonds and so on, of a small but ambitious country, with a need for revenge on the world.

Step 1 - What is a nuclear fission bomb?

Fission bombs derive their power from nuclear fission, where heavy nuclei (uranium or plutonium) are bombarded by neutrons and split into lighter elements, more neutrons and energy. These newly liberated neutrons then bombard other nuclei, which then split and bombard other nuclei, and so on, creating a nuclear chain reaction which releases large amounts of energy. These are historically called atomic bombs, atom bombs, or A-bombs, though this name is not precise due to the fact that chemical reactions release energy from atomic bonds (excluding bonds between nuclei) and fusion is no less atomic than fission. Despite this possible confusion, the term atom bomb has still been generally accepted to refer specifically to nuclear weapons and most commonly to pure fission devices.

Step 2 - What do you need?

a. The fissionable material

Plutonium239 isotope. Around 25 pounds (10 kg) would be enough. If you could find some Uranium235, that would be good, but not great. You would need to refine it using a gas centrifuge. The uranium hexafluoride gas is piped in a cylinder, which is then spun at high speed. The rotation causes a centrifugal force that leaves the heavier U-238 isotopes at the outside of the cylinder, while the lighter U-235 isotopes are left at the center. The process is repeated many times over through a cascade of centrifuges to create uranium of the desired level of enrichment. To be used as the fissile core of a nuclear weapon, the uranium has to be enriched to more than 90 per cent and be produced in large quantities.

You could try buying it from a former Soviet Republic, or from Iran, since they're trying so hard to produce it. North Korea is not ready yet, and unfortunately, Iraqi dealers retired from the business.

b. The explosive to start the nuclear chain reaction

100 pounds (44 kg) of trinitrotoluene (TNT). Gelignite (an explosive material consisting of collodion-cotton (a type of nitrocellulose or gun cotton) dissolved in nitroglycerine and mixed with wood pulp and sodium or potassium nitrate) would be better. Semtex would be good too, but it's a bit hard to get, these days.

c. The detonator

To fabricate a detonator for the device, get a radio controlled (RC) servo mechanism, as found in RC model airplanes and cars. With a modicum of effort, a remote plunger can be made that will strike a detonator cap to effect a small explosion. These detonation caps can be found in the electrical supply section of your local supermarket. If you're an electronics wiz, you should be able to make it using a cellphone.

d. The pusher

The explosion shock wave might be of such short duration that only a fraction of the pit is compressed at any instant as it passes through it. A pusher shell made out of low density metal such as aluminium, beryllium, or an alloy of the two metals (aluminium being easier and safer to shape but beryllium reflecting neutrons back into the core) may be needed and is located between the explosive lens and the tamper. It works by reflecting some of the shock wave backwards which has the effect of lengthening it. The tamper or reflector might be designed to work as the pusher too, although a low density material is best for the pusher but a high density one for the tamper. To maximize efficiency of energy transfer, the density difference between layers should be minimized.

Step 3 - How to build the nuke?

You will need to get the fissile material to the critical mass in order to start the chain reaction, which depends upon the size, shape and purity of the material as well as what surrounds the material. Your weapons-grade uranium will have to be in subcritical configuration.

First, you must arrange the uranium into two hemispherical shapes, separated by about 4 cm. Since it's highly radioactive, the best way do it is to ask the friend owning the small country to let you use one his facilities. You could use a nuclear plant, a steel factory or even a well equipped pharmaceutical installation as a disguise for your plans.

It is not sufficient to pack explosive into a spherical shell around the tamper and detonate it simultaneously at several places because the tamper and plutonium pit will simply squeeze out between the gaps in the detonation front. Instead, the shock wave must be carefully shaped into a perfect sphere centered on the pit and traveling inwards. This is achieved by using a spherical shell of closely fitting and accurately shaped bodies of explosives of different propagation speeds to form explosive lenses.

After a few careful calculations, all you need now is to carefully pack and transport your nuclear bomb to the targeted location. If you happen to be an Al-Qaeda fan, you should try to infiltrate a military facility, for the psychological effect. Watch it, though, they are usually well guarded!

Step 4 - Disguising the bomb and placing it for detonation

The smallest nuclear warhead deployed by the United States was the W54, which was used in the Davy Crockett recoilless rifle; warheads in this weapon weighed about 23 kg and had yields of 0.01 to 0.25 kilotons. This is small in comparison to thermonuclear weapons, but remains a very large explosion with lethal acute radiation effects and potential for substantial fallout. It is generally believed that the W54 may be nearly the smallest possible nuclear weapon, though this may be only smallest by weight or volume, not simply smallest diameter.

The best way to disguise it would be in the form of an ordinary appliance, like a copier, a widescreen TV set, or any other inconspicuous electronic device.

Now, all you have to do is transport it to the selected location and get to a safe distance of a few tens of miles, but not far enough to get out of the range of the remote detonator. That is why a cellphone is strongly recommended for its wide range capabilities.

The IMO Compendium: A Collection of Problems Suggested for The International Mathematical Olympiads: 1959-2009

2011-08-07T15:02:00.003+07:00

Duan Djuki, Vladimir Jankovi, Ivan Mati and Nikola Petrovi, "The IMO Compendium: A Collection of Problems Suggested for The International Mathematical Olympiads: 1959-2009 Second Edition"

Sp inger | 2011 | ISBN: 1441998535 | 823 pages | PDF | 6,2 MB

"The IMO Compendium" is the ultimate collection of challenging high-school-level mathematics problems and is an invaluable resource not only for high-school students preparing for mathematics competitions, but for anyone who loves and appreciates mathematics.

The International Mathematical Olympiad (IMO), nearing its 50th anniversary, has become the most popular and prestigious competition for high-school students interested in mathematics. Only six students from each participating country are given the honor of participating in this competition every year. The IMO represents not only a great opportunity to tackle interesting and challenging mathematics problems, it also offers a way for high school students to measure up with students from the rest of the world.

Until the first edition of this book appearing in 2006, it has been almost impossible to obtain a complete collection of the problems proposed at the IMO in book form. "The IMO Compendium" is the result of a collaboration between four former IMO participants from Yugoslavia, now Serbia and Montenegro, to rescue these problems from old and scattered manuscripts, and produce the ultimate source of IMO practice problems. This book attempts to gather all the problems and solutions appearing on the IMO through 2009. This second edition contains 143 new problems, picking up where the 1959-2004 edition has left off.

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What Steers Vampire Bats to Blood: Heat-Detecting Molecules On Noses Discovered

2011-08-06T20:21:00.001+07:00

The vampire bat

Scientists have known for years that when vampire bats tear through an animal's skin with their razor-sharp teeth, their noses guide them to the best spots -- where a precise bite will strike a vein and spill forth nourishing blood. But nobody knew exactly how bats knew where to bite.
By investigating wild vampire bats in South America, researchers at the University of California, San Francisco and Instituto Venezolano de Investigaciones Científicas in Caracas, Venezuela have discovered their secret: a sensitive, heat-detecting molecule covering nerve endings on their noses called TRPV1. A number of pharmaceutical and biotech companies are working on developing new pain medications that target molecules like TRPV1.
"Vampire bats feed on blood, and it's useful for them to have an infrared detector to be able to find the circulation," said David Julius, PhD, the Morris Herzstein Chair in Molecular Biology & Medicine at UCSF, who led the research.
Similar TRPV1 molecules can be found on pain sensing nerve fibers in human tongue, skin or eyes. They allow people to detect the chemical capsaicin in chili peppers and experience the burning tinge of spicy food.
Described in the journal Nature, the discovery highlights how small changes to genes in the genome of a species can contribute to major evolutionary adaptations over time -- in this case, allowing the vampire bat to detect infrared heat from their prey, helping them efficiently find and feed on blood.
The work also adds a piece to a larger puzzle related to human health and drug design because these same molecules are involved in pain sensation, such as that associated with touching a hot object, or hypersensitivity to heat after injury and inflammation -- as occurs with sunburn.
"There is a double-edged sword with pain," Julius said. "Pain is necessary as a warning system to let us know when we are in danger of injury but, at the same time, pain can outlive its usefulness as a warning system when it fails to resolve and becomes chronic and debilitating."

Sensory Nerves -- How the Brain Experiences the World

The human brain does not connect directly with the world but instead floats secluded in a protective bubble of cerebrospinal fluid within the skull. All the information the brain receives about Earthly sights, smells, textures, and tastes comes through long nerve fibers that make up the body's sensory system, which connect the brain with our eyes, noses, fingers and tongues.
At the ends of these nerve fibers, cues that give life to our perception of the world are collected. Tiny molecular channels covering these nerve endings can alternatively open or close if they perceive the proper stimulus from a chemical, heat, cold or the pressure of touch. When they do, and when the right balance of openings and closings occurs all over a nerve ending, that nerve will fire, sending a signal to the brain that says "hot" or "cold" or "hard" or "bitter" or "pretty"? (something for taste and sight) depending on the type of stimulus.
This basic physiology informs our awareness and also warns our brains about noxious dangers of the world. Painful stimuli signal danger to the brain and cause us to wince, squint, gasp or otherwise pull away to protect ourselves.
"There is a lot of stuff in our environment that we want to stay away from," Julius said.
TRPV1, one of these sensory system channels, does belong to a large family of similar molecules common to many types of animals but they differ slightly from animal to animal -- both in terms of their DNA and in terms of where they appear in the body.
Subtle changes to these molecules contribute to highly specialized physiologies for sensing the world. Many animals have highly specialized adaptations allowing them to see, feel, hear or taste in special ways. The heat-sensing molecules within vampire bat noses is one example.
Vampire Bats Run like Horses and Feed on Cows
In appearance, the furry, bean-shaped bat with its rodent-like face resembles a rat with wings, but bats are actually more closely related in evolution to dogs and horses. In fact, vampire bats in the wild will gallop and leap across the ground much in the same way that horses do.
In South American where they are common, vampire bats approach their prey on the ground, galloping quickly and quietly as they sneak up on, bite, and drink the blood from sleeping cows, goats and birds.
Vampire bats are the only known mammal that survives solely on blood, and they need to drink it pretty much every day to survive. They support this need through a number of evolutionary adaptations.
Like other bats, they feed only at night, and they have excellent eyesight enhanced by acute hearing and an ability to emit high-pitched sounds that help them navigate. Their teeth lack enamel, which keeps them constantly razor sharp and allows them to delicately tear through the hide of a sleeping animal without waking it. Grooves in their tongue draw up the blood seeping through the open wound through capillary action, and they have anticoagulation chemicals inside their saliva to keep it flowing.
Within minutes of sinking its teeth in an animal's flesh, an adult vampire bat can drink half its body weight in blood. But first they must find a vein, helped by it's a major adaptations: heat-sensing ability, which allows them to "see" a vein at night.
Researchers have known for years that pits on vampire bats' noses allow them to detect blood vessels because they radiate heat. But no one knew exactly how this occurred.
Working with three researchers in South America, Julius' postdoctoral fellows Elena Gracheva, PhD and Julio Cordero-Morales, PhD, together with UCSF colleagues Nicholas Ingolia, PhD and Jonathan Weissman, PhD, sequenced genes from samples of nose tissue from wild vampire bats in Venezuela, determining that TRPV1 is the molecule responsible for their ability to detect heat.
They also determined that it was not just TRPV1 but an evolutionary genetic variation of it that allows vampire bats to detect low temperature heat. Through a mechanism known as "alternative splicing" a special form of the molecule emerged in the noses of the bats, becoming a sensitive detector for finding the hottest spots.
This work was supported by funding from the National Institutes of Health and the Howard Hughes Medical Institute. Additional support was provided by a Ruth L. Kirschstein National Research Service Award and a Pathway to Independence Fellowship from the UCSF Cardiovascular Research Institute. David Julius is on the advisory board of Hydra Biosciences, Inc., which is investigating potential drugs that target molecules like TRPV1.

Natural Solutions for Bladder Control

2011-08-05T21:35:00.001+07:00

Because the incidence of minor bladder leakage and some sense of loss of control of urinary function is so prevalent in women after age 40, some physicians consider it a fairly normal part of the ageing process in women. In fact the incidence of a leaky bladder and weakness in controlling the stream of urination is fundamentally tied to a woman's age and reproductive history and health.
Promoting Health to Improve Kidney and Bladder Function
The process of childbirth, weight gain and loss, sedentary lifestyle and other factors all play a role in contributing to the problem of occasional incontinence.
Physicians seeking non-invasive methods of helping women regain good bladder control and a sense of confidence and actually taking proactive steps to improve their bladder control have many lines of defense to offer. Although the methods of healing offered by most naturopaths may not be an overnight solution there are products to help women overcome their sense of embarrassment at minor leakage problems that can be used while the problem is approached from several avenues.
All of these may take time and effort but they do not require invasive surgery neither do they require a woman to weigh pros and cons of prescription drug therapy or the unpredictable outcome of surgical interventions.
Since the aging process and hormonal levels are key to diagnosing the root of a urinary incontinence problem, the first place a naturopathic physician will start is to look at the hormonal levels of the woman who is seeking help.
Getting to the Root of the Bladder Problem
The tissue making up the urethra is prone to thinning and stretching based upon hormonal health and the functioning of this tissue is absolutely related to its health. Correction of a problem stemming from hormonal and nutritional deficiencies may take some time but are certainly worth a try. Correction of the problem at the root makes for a long term solution. Dietary additions and supplements can turn this trend around for many women. Basically eating a diet rich in phytoestrogens and isoflavones and adding soy containing foods to the diet may be all that is necessary.
Long Term Solutions to Minor Incontinence Take Time
Chronic bladder inflammation often contributes to deeper bladder problems and can be linked often to sensitivities and allergies that may have been undetected. Once these are pinpointed, steps to eliminate dietary problems can be taken. This may include elimination of dairy, soy, egg, wheat (gluten) and or other potential allergens. In fact permanent elimination is not always necessary. But tissues need time to heal.
Don't Underestimate Nutrition's Role in Bladder Problems
Other nutrients and foods that are often found culprit include sugar, caffeine, fatty and fried foods, junk foods and refined foods in general. Basically the system can often do without many of these non-nutrients. Whole body healing can occur and urinary bladder health can return to normal.

The simple act of eliminating caffeine and drinking more water can restore bladder function and health. Caffeine often has the effect of causing undue distress to the bladder, making it more active than normal and irritating the tissues and lining of the bladder. The addition of cranberry juice to the diet, especially in the case of a woman who suffers from repeated urinary tract infections can make a huge difference in bladder health.

It is also often discovered that not having the appropriate intestinal and vaginal bacteria present can exacerbate the problem of incontinence and contributes heavily to yeast infections and pelvic discomfort.

The addition of vitamins B, C, and D and flaxseed oil and bromelain have been suggested by some naturopaths to aid bladder health. Yogurt and /or probiotics have also been seen to make a huge difference.
Herbal Medicines Used to Heal the Bladder
Herbal medicines are also used to aid healing and fight inflammation of the urinary tract include those with diuretic action, also those with astringent, antiseptic and soothing actions. Some of the more frequently mentioned herbal supplements include: horsetail, buchu, usnea, cornsilk, marshmallow root and cleavers.

Interestingly enough when a naturopath studies health problems she or he can often link seemingly unrelated health issues to the same factor and what is good for the bladder is often good for the stomach, the nerves and other systems of the body.
Therapeutic Physical Exercise to Improve Bladder Function
Naturopathic doctors will also often suggest proactive physical exercises and other health inducing activities. Exercises to strengthen the sphincter action of the bladder's openings and the pelvic floor can be very important to helping a woman regain strength and bladder health. Kegels exercises are well known to increase a woman's ability to control her bladder function as well as being good for the strengthening of genital muscles used for sexual activity.

Basically it's all connected, according to the doctor looking for more natural means to help your healing and keep you healthy.

Data Traveling by Light

2011-08-04T16:01:00.000+07:00

Regular LEDs can be turned into optical WLAN with only a few additional components thanks to visible light communication (in short, VLC). The lights are then not just lighting up, they also transfer data. They send films in HD quality to your iPhone or laptop, with no loss in quality, quickly and safely.

Just imagine the following scenario: four people are comfortably ensconced in a room. Each one of them can watch a film from the Internet on his or her laptop, in HD quality. This is made possible thanks to optical WLAN. Light from the LEDs in the overhead lights serves as the transfer medium. For a long time, this was just a vision for the future. However, since scientists from the Fraunhofer Institute for Telecommunications, Heinrich Hertz Institute HHI in Berlin, Germany, have developed a new transfer technology for video data within the scope of the OMEGA project of the EU, its implementation in real life is getting markedly closer.
At the end of May, the scientists were able to present the results of the project in Rennes, France. They were able to transfer data at a rate of 100 megabits per second (Mbit/s) without any losses, using LEDs in the ceiling that light up more than ten square meters (90 square feet). The receiver can be placed anywhere within this radius, which is currently the maximum range. "This means that we transferred four videos in HD quality to four different laptops at the same time," says Dr. Anagnostis Paraskevopoulos from the HHI.
"The fundamentals of visible light communication (VLC) were developed together with the industry partners Siemens and France Telecom Orange Labs," said the expert. At HHI, the team of project manager Klaus-Dieter Langer is now further developing the new technology. "For VLC the sources of light -- in this case, white-light LEDs -- provide lighting for the room at the same time they transfer information. With the aid of a special component, the modulator, we turn the LEDs off and on in very rapid succession and transfer the information as ones and zeros. The modulation of the light is imperceptible to the human eye. A simple photo diode on the laptop acts as a receiver.
As Klaus-Dieter Langer explains, "The diode catches the light, electronics decode the information and translate it into electrical impulses, meaning the language of the computer." One advantage is that it takes only a few components to prepare the LEDs so that they function as transfer media. One disadvantage is that as soon as something gets between the light and the photo diode (for example, when someone holds his hand over the diode) the transfer is impaired. Laptops, Palm devices or mobile telephones are all potential end devices.
The scientists emphasize that VLC is not intended to replace regular WLAN, PowerLAN or UMTS. It is best suited as an additional option for data transfer where radio transmission networks are not desired or not possible -- without needing new cables or equipment in the house. Combinations are also possible, such as optical WLAN in one direction and PowerLAN for the return channel. Films can be transferred to the PC like this and also played there, or they can be sent on to another computer.
The new transmission technology is suitable for hospitals, for example, because radio transmissions are not allowed there. Despite this fact, high data rates must be transmitted without losses and unzipped, according to the experts. If part of the communication occurs via the light in the surgical room, this would make it possible to control wireless surgical robots or transmit x-ray images. In airplanes, each passenger could view his own entertainment program on a display, saving aircraft manufacturers miles of cables. Another possible venue for the application of this technology are production facilities, where radio transmissions very often interfere with the processes.
Currently the scientists are developing their systems toward higher bit rates. "Using red-blue-green-white light LEDs, we were able to transmit 800 Mbit/s in the lab," said Klaus-Dieter Langer. "That is a world record for the VLC method."

Stem Cells Restore Cognitive Abilities Impaired by Brain Cancer Treatment

2011-08-04T15:55:00.000+07:00

Human neural stem cells are capable of helping people regain learning and memory abilities lost due to radiation treatment for brain tumors, a UC Irvine study suggests.

Research with rats found that stem cells transplanted two days after cranial irradiation restored cognitive function, as measured in one- and four-month assessments. In contrast, irradiated rats not treated with stem cells showed no cognitive improvement.
"Our findings provide solid evidence that such cells can be used to reverse radiation-induced damage of healthy tissue in the brain," said Charles Limoli, a UCI radiation oncology professor.
Study results appear in the July 15 issue of Cancer Research, a journal of the American Association for Cancer Research.
Radiotherapy for brain tumors is limited by how well the surrounding tissue tolerates it. Patients receiving radiation at effective levels suffer varying degrees of learning and memory loss that can adversely affect their quality of life.
"In almost every instance, people experience severe cognitive impairment that's progressive and debilitating," Limoli said. "Pediatric cancer patients can experience a drop of up to three IQ points per year."
For the UCI study, multipotent human neural stem cells were transplanted into the brains of rats that had undergone radiation treatment. They migrated throughout the hippocampus -- a region known for the growth of new neurons -- and developed into brain cells.
Researchers assessed the rats one month and four months after transplantation, noting enhanced learning and memory abilities at both intervals.
Additionally, they found that transplanting as few as 100,000 human neural stem cells was sufficient to improve cognition after cranial irradiation. Of cells surviving the process, about 15 percent turned into new neurons, while another 45 percent became astrocytes and oligodendrocytes -- cells that support cerebral neurons.
Most notably, Limoli said, he and his colleagues discovered that about 11 percent of the engrafted cells expressed a behaviorally induced marker of learning, indicating the functional integration of those cells into memory circuits in the hippocampus.
"This research suggests that stem cell therapies may one day be implemented in the clinic to provide relief to patients suffering from cognitive impairments incurred as a result of their cancer treatments," Limoli said. "While much work remains, a clinical trial analyzing the safety of such approaches may be possible within a few years, most likely with patients afflicted with glioblastoma multiforme, a particularly aggressive and deadly form of brain cancer."
Munjal Acharya, Lori-Ann Christie, Mary Lan and Erich Giedzinski of UCI and John Fike and Susanna Rosi of UC San Francisco contributed to the study, which was funded by the California Institute for Regenerative Medicine, the National Institutes of Health and the U.S. Department of Energy.

Natural Cold Treatment

2011-08-03T09:29:00.003+07:00

Chicken Soup May Be the Answer

Chicken Soup

Having a cold is miserable. No one likes suffering what seems to be a yearly winter ritual as the latest cold bug makes the rounds. Until someone finds a cure from the common cold, we're stuck with stuffy noses and chest-rattling coughs. Fortunately, natural cold treatment is often as effective as over the counter medications, and surprisingly, grandma had it right in a lot of ways.
Natural Ways to Care for a Cold
The age old cold cure, chicken soup isn't that far off the mark. Mom's steamy bowl of warm broth, meat, and vegetables is actually a great way to help reduce the symptoms of a cold. A steaming bowl of soup helps to loosen mucous and clear out nasal passages. The warm liquid soothes an irritated throat and can reduce inflammation. Best of all, the nutrients commonly found in a good chicken soup include antioxidants, protein, and minerals that can help strengthen your body as it fights off a cold virus.
Of course, chicken soup can't really cure a cold. Sadly, there isn't anything yet known to humankind that can do that. However, there are plenty of ways to reduce cold symptoms and make a cold victim more comfortable.
* If congestion is an issue, moist heat is the best treatment. A hot shower or a steaming cup of tea will loosen mucous and ease inflamed bronchial tubes.
* Coughing can be eased with a spoonful of honey. This is a good treatment for young children over 1 year of age that shouldn't take cold medicine.
* Use a cool mist humidifier, especially at night, to ease coughing and congestion.
* Treat a sore throat by gargling with a cup of warm water with 1 teaspoon of salt dissolved in it 2 to 3 times a day.
* Vitamin C can't cure or prevent a cold, but studies show it may shorten the duration of a cold, so try taking a supplement and eating foods high in vitamin C.
In general, your body will combat any sickness more effectively if it is healthy before the infection. Perhaps the best defense against a cold is to eat a wide variety of healthy foods that are mostly plant based. Regular exercise will also result in a strong cardio-vascular system which means a respiratory infection may be less severe. It goes without saying that plenty of hand washing will help prevent colds and protect others if you are infected.
Hydration is essential to combating colds or most other illnesses. Although regular fluid intake is important in general, it can be a vital element in combating a cold. Aim for eight 10 ounce glasses of fluid each day. Water is the best fluid for the body, but juice, sports drinks and herbal tea are also good choices in moderation. Avoid drinks like cola and coffee that are high in caffeine because they will hamper your ability to rest and act as a diuretic that will make you have to go to the bathroom more often and can lead to dehydration. Of course, grandma's chicken soup is not only a great fluid for treating colds, but a great way to lift your spirits too.

Power Up Your Mind: Learn Faster, Work Smarter

2011-08-02T15:42:00.000+07:00

Author: Bill Lucas

Publisher: Nicholas Brealey Publishing (2001)

Binding: Paperback, 272 pages

ISBN-10: 185788275X
Will revolutionize our understanding of how our brains are pre-wired to learn and the practical steps we can take to prepare ourselves--emotionally and physically--to participate fully in the process.

Chemists Transform Acids Into Bases: Research Offers Vast Family of New Catalysts for Use in Drug Discovery, Biotechnology

2011-08-02T09:34:00.001+07:00

Chemists at the University of California, Riverside have accomplished in the lab what until now was considered impossible: transform a family of compounds which are acids into bases.

Guy Bertrand is a distinguished professor of chemistry at UC Riverside

As our chemistry lab sessions have taught us, acids are substances that taste sour and react with metals and bases (bases are the chemical opposite of acids). For example, compounds of the element boron are acidic while nitrogen and phosphorus compounds are basic.
The research, reported in the July 29 issue of Science, makes possible a vast array of chemical reactions -- such as those used in the pharmaceutical and biotechnology industries, manufacturing new materials, and research academic institutions.
"The result is totally counterintuitive," said Guy Bertrand, a distinguished professor of chemistry, who led the research. "When I presented preliminary results from this research at a conference recently, the audience was incredulous, saying this was simply unachievable. But we have achieved it. We have transformed boron compounds into nitrogen-like compounds. In other words, we have made acids behave like bases."
Bertrand's lab at UC Riverside specializes on catalysts. A catalyst is a substance -- usually a metal to which ions or compounds are bound -- that facilitates or allows a chemical reaction, but is neither consumed nor altered by the reaction itself. Crucial to the reaction's success, a catalyst is like the car engine enabling an uphill drive. While only about 30 metals are used to form catalysts, the binding ions or molecules, called ligands, can number in the millions, allowing for numerous catalysts. Currently, the majority of these ligands are nitrogen- or phosphorus-based.
"The trouble with using phosphorus-based catalysts is that phosphorus is toxic and it can contaminate the end products," Bertrand said. "Our work shows that it is now possible to replace phosphorus ligands in catalysts with boron ligands. And boron is not toxic. Catalysis research has advanced in small, incremental steps since the first catalytic reaction took place in 1902 in France. Our work is a quantum leap in catalysis research because a vast family of new catalysts can now be added to the mix. What kind of reactions these new boron-based catalysts are capable of facilitating is as yet unknown. What is known, though, is that they are potentially numerous."
Bertrand explained that acids cannot be used as ligands to form a catalyst. Instead, bases must be used. While all boron compounds are acids, his lab has succeeded in making these compounds behave like bases. His lab achieved the result by modifying the number of electrons in boron, with no change to the atom's nucleus.
"It's almost like changing one atom into another atom," Bertrand said.
His research group stumbled upon the idea during one of its regular brainstorming meetings.
"I encourage my students and postdoctoral researchers to think outside the box and not be inhibited or intimidated about sharing ideas with the group," he said. "The smaller these brainstorming groups are, the freer the participants feel about bringing new and unconventional ideas to the table, I have found. About 90 percent of the time, the ideas are ultimately not useful. But then, about 10 percent of the time we have something to work with."
The research was supported by grants to Bertrand from the National Science Foundation and the U.S. Department of Energy.
An internationally renowned scientist, Bertrand came to UCR in 2001 from France's national research agency, the Centre National de la Recherche Scientifique (CNRS). He is the director of the UCR-CNRS Joint Research Chemistry Laboratory.
A recipient of numerous awards and honors, most recently he won the 2009-2010 Sir Ronald Nyholm Prize for his seminal research on the chemistry of phosphorus-phosphorus bonds and the chemistry of stable carbenes and their complexes.
He is a recipient of the Japanese Society for Promotion of Science Award, the Humboldt Award, the International Council on Main Group Chemistry Award, and the Grand Prix Le Bel of the French Chemical Society. He is a fellow of the American Association for the Advancement of Sciences, and a member of the French Academy of Sciences, the European Academy of Sciences, Academia Europea, and Academies des Technologies.
He has authored more than 300 scholarly papers and holds 35 patents.
Bertrand was joined in the research by Rei Kinjo and Bruno Donnadieu of UCR; and Mehmet Ali Celik and Gernot Frenking of Philipps-Universitat Marburg, Germany.
UCR's Office of Technology Commercialization has filed a provisional patent application on the boron-based ligands developed in Bertrand's lab.

Problems and Solutions in Engineering Chemistry

2011-08-01T20:41:00.000+07:00

Problems and Solutions in Engineering Chemistry Laxmi Publications | 2008 | ISBN: 8131803260 | 337 pages | PDF | 10,3 MB

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Mathematical Olympiad in China: Problems and Solutions

2011-08-01T20:36:00.000+07:00

Bin Xiong, Yee Lee Peng, "Mathematical Olympiad in China: Problems and Solutions" World Scientific Publishing Company | 2007 | ISBN: 9812707891 | 276 pages | PDF | 6,3 MB

The International Mathematical Olympiad (IMO) is a competition for high school students. China has taken part in IMO twenty times since 1985 and has won the top ranking for countries thirteen times, with a multitude of golds for individual students. The 6 students China sent every year were selected from 20 to 30 students among approximately 130 students who take part in the China Mathematical Competition during the winter months. This volume comprises a collection of original problems with solutions that China used to train their Olympiad team in the years from 2003 to 2006.

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Problems in Real Analysis: Advanced Calculus on the Real Axis

2011-08-01T20:30:00.001+07:00

Teodora-Liliana Radulescu, Vincentiu D. Radulescu, Titu Andreescu "Problems in Real Analysis: Advanced Calculus on the Real Axis" Springer | English | 2009-05-29 | ISBN: 0387773789 | 452 pages | PDF | 3,7 MB

Problems in Real Analysis: Advanced Calculus on the Real Axis features a comprehensive collection of challenging problems in mathematical analysis that aim to promote creative, non-standard techniques for solving problems. This self-contained text offers a host of new mathematical tools and strategies which develop a connection between analysis and other mathematical disciplines, such as physics and engineering. A broad view of mathematics is presented throughout; the text is excellent for the classroom or self-study. It is intended for undergraduate and graduate students in mathematics, as well as for researchers engaged in the interplay between applied analysis, mathematical physics, and numerical analysis. Key features: *Uses competition-inspired problems as a platform for training typical inventive skills; *Develops basic valuable techniques for solving problems in mathematical analysis on the real axis and provides solid preparation for deeper study of real analysis; *Includes numerous examples and interesting, valuable historical accounts of ideas and methods in analysis; *Offers a systematic path to organizing a natural transition that bridges elementary problem-solving activity to independent exploration of new results and properties.

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When to Use Cold Medicine

2011-08-01T16:51:00.002+07:00

How to Safely Use Cold Medicine

It's easy to reach for cold medicine when you aren't feeling well, and, generally speaking, there isn't any reason why a healthy adult shouldn't. However, there are some medicines that should only be used for a short time and others that are not appropriate for certain people.

Cold Medicine 101

There has been a lot of press about cold medicine over the past few years. Some doctors have come out saying that cold medicine is not only unhelpful, it can even be harmful. However, the majority of medical professionals still feel that the right medications can be helpful in treating cold symptoms.
In general, problems with cold medicines come in two areas: accidental overdose and previous health conditions. Many people choose combination cold medicines because they are convenient and treat a wide array of symptoms. However, combinations medicines can be dangerous because people often don't realize what drugs the medicines contain and may double dose themselves by taking more than one type of medicine.
Another common problem associated with cold medicines occurs when a person has a previous medical condition and takes a cold medication that aggravates that condition. People with asthma, certain allergies, high blood pressure, heart disease or who are pregnant or take certain prescription medications should be especially careful when taking cold medicines. If you suffer from any pre-existing medical condition, ask your doctor for a list of safe medications.
In general, the following tips can help in the proper use of over the counter cold medicines. If you have any doubts about whether or not a medication is right for you, consult your doctor or a pharmacist.
* Treat only the symptoms that are present. If you have congestion but no cough, don't take a combination runny nose/cough medicine.
* Carefully follow the dosage instructions on a medication and know what is in it.
* People with asthma should avoid medications that contain antihistamines because they thicken mucous secretions and can cause difficulty breathing.
* People with uncontrolled high blood pressure should avoid decongestants or take medications designed specifically for those with high blood pressure.
* Nasal sprays can actually increase congestion if used for more than three consecutive days. Non-medicated saline sprays are a good alternative.
* Many doctors feel cough medicines are ineffective and should be avoided. If you have a serious cough, contact your doctor for a medical opinion.

Cold Medicine for Kids

In 2007, the FDA released a statement recommending that cold medicines not be used in children under the age of 6. The age has recently been reduced to 4, but it's best to consult a pediatrician before administering cold medicine to young children. As with adults, many of the problems with children's cold medicine arose because of combination medicines. Parents often didn't realize that a cold medicine contained a fever reducer like acetaminophen or ibuprofen and gave their children a second dose of those medicines. These overdoses resulted in dangerous medical complications and even deaths. While it is tempting to give cold medicine to an uncomfortable child, you should always consult a pediatrician first. Often, a doctor will okay the use of medication but may have specific guidelines or suggestions for your child.

IMO problems from 1959 to 2011

2011-07-31T17:24:00.000+07:00

IMO problems from 1959 to 2011.

English language

Common Cold vs the Flu

2011-07-30T20:59:00.002+07:00

Is it the Flu?
Flu season is upon us, and it's likely that you or someone in your family is going to get sick if they aren't already! But is the congestion and body aches the result of influenza or just a nasty cold? Our handy primer will help you tell the difference between the potentially dangerous flu and a common cold.

What is the Flu?

Part of the confusion that surrounds influenza stems from the fact that people use the term "flu" to describe several different illnesses that range from stomach viruses to sinus infections. The "stomach flu," is not an actual medical diagnosis. Instead, it's a common name used for gastroenteritis. Likewise, some people refer to a severe cold as the flu when it is actually a rhinovirus or similar respiratory infection.

True influenza is a specific virus (with three variations known as influenza A, B, and C) and is the only virus that can cause an honest case of the flu. On the other hand, the common cold can be caused by over a thousand different viruses. Unfortunately, many cold viruses can have symptoms quite similar to those seen in influenza. Knowing if you have influenza can be important because the flu can lead to more serious problems like pneumonia.
The Difference Between Colds and Flu

It can be difficult to distinguish between a common cold vs. the flu, especially if you've never had the flu before. If you still aren't sure after reading this article, you may want to call your doctor who can conduct a test to determine if you have influenza.
Common Cold Symptoms

The common cold can be cause by a wide variety of viruses, so it's rare to have two colds that present in exactly the same way. That being said, most colds do have some common features.

* A cold usually begins with a sore throat that goes away after 1 to 2 days.
* Most colds begin gradually and get worse over the course of 7 to 10 days.
* After a sore throat, most colds cause a runny nose or congestion.
* About five days after the first symptoms, many colds result in a cough.
* Fevers are rare in adults with common colds and usually remain low grade (under 102° F).
* If cold symptoms last beyond ten days, you may have developed a secondary bacterial infection and should see a doctor.

Flu Symptoms

Those who have had the flu often say that they would never mistake it for a cold. Influenza is a serious viral infection that often strikes without warning leaving victims feeling as if they were hit by a ton of bricks. The following are signs of the flu.

* The flu is almost always accompanied by a fever, often reaching temperatures of 102° F or more.
* The flu comes on quite suddenly over a period of 24 to 48 hours and initially manifests as sever body aches, headache, congestion, and cough.
* The flu causes extreme exhaustion, especially in the early stages. Many people feel as if they can't get out of bed.
* The flu often causes moderate to severe chest pain.
* Coughing, sneezing, and congestion may come with flu but are usually less pronounced than in a cold.

If you suspect that you or a member of your family has the flu, you should contact a doctor immediately. There are anti-viral medications that can dramatically reduce the symptoms and length of the influenza infection, but they are only affective if given within the first day or two of infection. Most healthy adults recover from the flu within 1 to 2 weeks. Young children, the elderly, pregnant women and those with compromised immune systems are especially vulnerable to the flu and should be watched carefully throughout the duration of the illness.

Day 1 problem

2011-07-30T16:52:00.001+07:00

How many zero are the end of

Solution

The formula of permutation is . Then
so we'll find zero the end of 10000! and 9987!.

there are integers less than which are multiples of ,
and which are multiples of ,
and which are multiples of ,
and which are multiples of ,
and which are multiples of ,

so we get zero are the end of

By the same way we get zero are the end of

So there are are the end of .

Please correct me! by leave your comment . Thanks