Dental Jobs - Bestowing People With Shining and Healthy Teeth

The rise in number of hospitals, private clinics and awareness among people to take care of their health, has led to an increase in jobs for paramedical staff like dental assistants, nurses, technicians, dental hygienists etc. who provide proper care and maintenance of teeth. Dental assistants or nurses and dental technicians work closely with dentists to bestow people with shiny white and healthy teeth.

Dental assistant jobs are multidimensional and most of the assistants work in clinics or hospitals taking care of patients, office or laboratory duties and other specialised duties. nurse jobs profile includes the responsibilities given by the dentist; surgery preparation and assistance, sterilizing all dental tools and equipment after the patients have been treated. The assistants or nurses may also maintain records of patients. Although there is not any specialisation required to work as an assistant but some training is preferable.

Those with a science background can pursue a Diploma or Bachelor's Course in Nursing. Many government and private colleges offer such courses that can be pursued after Class 12. The remuneration for dental assistants and nurses is quite decent but the field requires arduous work. With experience a dental assistant can climb the ladder of success and become office manager,assisting instructor or dental product sales representative. Dental nurses can establish as dental hygienist, oral health practitioner or orthodontic therapist.

Dental technicians or technologists also work as part of the dental team. Their job responsibilities include making dentures, crowns, bridges and dental braces as per requirements. The job profile is to design, construct, modify and repair dental appliances for patients as recommended by the dentist. Prosthodontic technicians, conservation technicians, orthodontic technicians and maxillo-facial technicians/prosthetics are the areas of specialisation for dental technicians.

Most dental technicians get training on the job itself and can become accomplished technologists in four to five years. Students who want to pursue a career as a dental technician can join a good dental college after 10+2 and pursue a Diploma in Dental Technology offered by any recognised institute. The starting salary of a technician is quite decent but with experience the salary increases and so does the post. Technicians can become supervisors and managers. dental jobs be taken up at hospitals, clinics or laboratories. Those who want to be their own boss can even start their own labs or become dental suppliers. Teaching at an institute or Dental college is also option available for a technician.

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Career Planning - Rules of Engagement?

What the heck's that about you might be thinking. Well, for those wishing to take their career to the next level come hell or high water, here is a helpful plan of action. It is not for the lazy, hazy, or coasters of this world, so if that is you - look away now. I wouldn't want to catapult you out of your comfort zone. If, however, you are happy to be catapulted - read on.

Rules of engagement, as used by the police or military, have both general and specific applications, and are only known by the people who will implement them. They are a helpful pattern to consider in career planning for their useful framework and application. For instance:

• they provide consistent and repeatable standards of behaviour
• are well thought-out, detailed actions considered well in advance
• decide when, where and how actions should be used to achieve desired results

As you know, career planning needs to have a balanced strategy to be successful. In combat, if the rules of engagement are unbalanced, it can result in a person being too restrained to fulfil his mission, or too lax to comply with the commands.

So, how do rules of engagement work in career planning? Career planning has a few simple steps that will keep you in step with your goals - once you have produced your first one, simply rinse and repeat until you finally hang up your work boots. These steps are:

1) Take a roll call: where is the real you? Investigate what makes you get out of bed in the morning, what makes you throw the towel in and give up, and what really makes you tick. In other words, what are your strengths, weaknesses and interests?

2) Take an inventory: what are your options? Given your background, education and gifting, what is open to you now? What is the next step up? How can you get there? Be as specific as possible.

3) Have a reality check: Who or what is holding you back? What are the issues that prevent you from progressing? If it's education, can you take an online course? If it's family, can you work out a better solution? If it's health, can you diversify into an equally absorbing career?

Once you have your plan, you will be able to see the consistent behaviour patterns needed to work your detailed action plan, that will help you decide when, where and how you achieve your desired results. Rules of engagement complete!

Don't forget to include regular mentoring and training in your particular niche. This helps keeps you focused as you work your plan and has the added bonus of someone giving you continued support and expert knowledge to keep you on track.

Check out the following link now for more ideas on career planning and to see one of the best centres on the net, I hope this review on career planning and the rules of engagement has been helpful. source

Two Technology Trends in High-Frequency Trading

It was great to get back to the office after the Christmas break, no more cold turkey! Setting out plans for the coming year is a great opportunity to look at what the commentators are saying will be the trends of the New Year. The buzz in the High Frequency Trading space is all about the coming regulation and European Union MiFID 2 (Market in Financial Instruments Directive) in particular. I normally perceive regulation as a bad thing, more work with no gain, but we would not have the market fragmentation in Europe without MiFID; which broke the monopoly of country stock exchanges. 45% of the FTSE 100 stocks are now traded off the London Stock Exchange. The Tabb Group, a consultancy, reckons HFT accounts for 56% of all equities trades in the US and 38% in Europe. The trend can only go one way with more market players getting into the HFT style of trading.

Two technology trends to watch this quarter

Growth in the market is great news for us in the technology space but we are also seeing developments in the Low Latency Networking space that will affect the infrastructure designs we are providing. The first is Precision Time Protocol (IEEE 1588, PTP) in silicon on network cards and the second is purchase of Voltaire, subject to approvals.

What PTP means for the Low Latency market.

• Accurate measurement of latency arbitrage. Traders will know to micro-second how long their position changes are taking and will be able to see arbitrage opportunities. The losers will have to get smarter which is good for market efficiency.
• Consultants who have built a business on deploying estimated trade times by inserting probes and parallel processing runs will have to amend their approach because the network side will be producing accurate results, at last!
• The providers of network kernel by-pass acceleration will be able to quickly and simply demonstrate the benefits of their technology, making it easier to sell the concept. Who can argue with figures that trustworthy that so a drop from 20ms to 9ms.

The other news at the end of last year was the purchase of Voltaire, the Infiniband infrastructure vendor, by silicon manufacturer Mellanox, the only other major player in the Infiniband tech space. This consolidation of the market will focus the attention on the furious Infiniband verses 10 Gigbait Ethernet (10GbitE) debate. Watching the vendors throwing stones at one another will be fun but the High Performance Computing market is big enough to support both technologies and I think the High Frequency Trading market will do the same.

It's going to be a great year to be building out Low Latency solutions this year, can't wait!

Article Source: http://EzineArticles.com/?expert=Anito_O'Malley

Discover The Uniqueness And Dynamic Nature Of These LED Flashlights

Nothing can be more frustrating than an electricity cut and you are left without any other source of illumination in the house. It even gets worse when you are trying to do something urgent and there goes the lighting. That is why the Ultrafire C2 Flashlight was introduced. With its very unique features you do not have to worry too much when such a situation arises. Why is it the best choice for such a situation? It gives great light illumination and it is strongly constructed such that it can be handled by anyone without the risk of breakage. Additionally, they are water resistant, which is the one main source of damage to electric devices.

What are some of the features of these LED flashlights? First, it produces bright illumination that will brighten up your room almost as much as electricity would. Secondly, it is a long lasting flashlight and strong at the same time. It has been constructed in a way to avoid easy breakage and also the fact that it is water resistant makes it even more durable. Finally, its casing is mane of a strong form of aluminum alloy that enhances the flashlight's durability.

What are some of the advantages of these flashlights? They are very convenient for particular purposes such as hunting, patrolling etc. The reason why it would be used for such purposes is the fact that they give very bright light that is necessary for such activities. Secondly, they can be used by some families that are not well-off and may find it necessary to cut down on electricity costs. In the long run it may be a useful alternative since the only costs you get to incur are purchase costs and once in a while you may need to replace either the battery or the bulb. Generally it is a flashlight that is useful for any household needs. In complex settings then it can be used in research institutions such as in the process of mineral testing or the identification of bacteria.

The following are some of the precaution rules given so as to use it effectively without harm or damages.

Make sure that you are sure when to re-charge the flashlight so as to avoid any damages to the bulb and the battery as well. It is important that you only re-charge it when you start noticing that the bulb has started dimming. This prolongs the life span of your battery as well as that of your bulb.

Its brightness can easily cause harm to one's eyes. It is therefore necessary that you avoid having it pointed directly to one's eyes and most importantly those of children. If possible keep the flashlight away from children to avoid these risky situations

The above will go a long way to ensure that you give your LED flashlight maximum life and at the same time ensure that you enjoy its benefits tot eh maximum. It is not only a good source of light but a cost saver as well for those who are trying to cut down on electricity costs.

Article Source: http://EzineArticles.com/?expert=Kayla_Jeong

Study Skills Guide For Students

Have you read about some standard memorization techniques? (Can you even remember those memory techniques?) Here are a couple of studies habits that help you retain information— and recall it when you need it. The information sticks! These study techniques also help you improve your overall memory function. 

First, Timing is everything. 

Choosing the right timing will be the first step to improving your grades. Believe it! It turns out that your memory is geared to work better by using certain intervals of study and rest. Once you understand this timing—and use it--you'll put your brain in the best position to learn. Super memory, here you come! 

Here's the deal. If you follow the time table below, success will follow: · Review a small chunk of your test information . Don't tackle more than a page or two, and don't review for more than half an hour—even if you're tempted. · Take a break, but come back to the task in five minutes. · Review for another half an hour. · Take another break. · Come back to studying an hour later. Yes, rest that brain for an hour. · Come back to the information after an hour and review it for 15 minutes. · Repeat the 15 minute review for the next 24 hours. 

Congratulations! When you use this routine, you make a transformation. Your short term memory has become long term memory! Your reward will be better grades. 

Second, Tell Yourself a Story 

Oh, you know how boring it is to memorize lists! You feel sleepy even though it's the middle of the day. Surely there's a better way. 

There is! If you turn the information into a story, things change. This study technique helps you stay awake and interested in the information. It helps you get better grades because it's easier to recall the information during the actual test. 

Here's an example. Say you've got a list of vocabulary words. Instead of staring at those words until you zone out, try using the words to make up a story. Write the story down. Use the words appropriately, with their meanings. Don't worry if the story seems silly or doesn't make a lot of sense. It will take some work, and you'll laugh because the story will probably be goofy. 

But guess what? Come exam time, you'll be surprised how well you remember the words' meaning and spelling. This is a study tip that works on your memory and pays off with better grades.

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What Online Postcard Printers Can Do For You?

People usually ask a lot of questions related to the web based printing companies that prints and creates postcards. How does the process usually works? What must they do on their part? Is it very easy as they say it is, and many more. Most people have thought of dipping into their past experiences when you have worked with a couple of online printing companies that designs and prints these cards and usually offer this overview. 

It is for a fact that almost all online printing companies that prints post cards operate in a slightly different method. However, most of them stick on the process that is commonly practiced these days. At the very least, this will usually aid you and especially your business to better understand the process of online printing companies that prints postcards and how will they benefit you and especially your business establishment in the market. 

The online postcard printing companies. Printing these very crucial cards are nothing new to the business industry. These printing companies have been around for a very long time, in fact, they have been around as long as the post cards. However, in the recent years, there has been a new and refreshed trend among these printing companies and it is the so called web based printing process. Nowadays, different online printing companies offer varied online printing services. 

Printing post cards online. Have you ever thought of how you can print your cards online? In the past years, printing these cards is usually done through a digital printer or an offset printing service. The difference here is that the creation and submission of the design and the mailing list is done through the ordering process. Before, it is a must for you to make your own design and then bring it to your chosen printing service that will scan your created design or also convert your design into a printing plate. But, with the aid of the internet, the usual process of printing your cards has changed a lot and has been much better and more convenient. Nowadays, you can submit your own created design through the printer’s website and have them printed for your convenience. There are even some online printing companies that will allow you to create your own card design through their website. 

The real convenience of online postcard printing. It is for a fact that there are usually different benefits that you and your business can get from an online printing company. One of these is convenience for you and all other persons who utilize the service. You can only have to interact with the printer online compared to hiring a traditional printing company which you have to talk to in person. And if the website is well created and is user friendly, the process of making a transaction with an online printing company can even be more enjoyable. All the difficult things or process that is related to printing will be done by the online printing company. Therefore, it leaves you with an easy and effortless time in making your cards for your business. 

The benefits of online printing cannot be underestimated. If you want to experience a quick and easy printing of your post card, then find a reliable online printer today. 

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Meteorites may have sparked life on Earth

Extraterrestrial objects colliding with Earth's ancient oceans may have sparked the molecules necessary for life.

duuuna / iStockphoto

Thoughts of meteors hurtling toward Earth usually generate visions of mass extinctions. But some recent studies paint a new picture: Large rocks hurtling in from space may have actually helped spark life on Earth.

Nobody would call early Earth a friendly place. Billions of years ago, it started as a red-hot sea of molten rock. But then the surface cooled enough for oceans to form. During that era meteorites slammed into Earth about 1,000 times more frequently than they do today.

While these conditions might not seem conducive to life, scientists say they may have been just the recipe needed to jump-start a few life-producing chemical reactions.

Geochemist Yoshihiro Furukawa at Tohoku University in Sendai, Japan had a theory about how this could happen. When large extraterrestrial objects crashed into Earth’s ancient oceans, they produced enormous heat and pressure that caused objects to vaporize, or turn into gas. Furukawa thought such powerful events may have triggered chemical reactions that generated organic molecules from basic ingredients. To test this theory, he and his colleagues designed a study.

To simulate the power of a collision between an extraterrestrial object and an ancient ocean, the scientists used a propellant gun. It keeps objects under high pressure, and when the pressure is released, the gun’s contents are expelled at high speeds.

To get the right recipe for such a collision, the scientists combined ingredients commonly found in meteorites and in Earth’s ancient oceans and atmosphere. The scientists mixed carbon, iron and nickel — elements found in the most common type of meteorites — with water, ammonia and nitrogen, which were present in early Earth.

The team placed these ingredients inside stainless steel canisters and used the gun to fire them at solid targets. The canisters reached speeds of more than 1 kilometer per second.

The researchers hoped to see how a high-temperature, high-velocity impact affected various mixtures of the ingredients. When canisters were fired at the target, the temperatures inside became scorching. They briefly rose to about 4,700 degrees Celsius (nearly 8500 degrees Fahrenheit). The pressure generated inside the canisters by the impact was about 60,000 times that of ordinary atmospheric pressure at sea level.

Afterward, the scientists analyzed the contents of the canisters. They recovered a variety of organic molecules, including fatty acids such as those found in cell membranes. The team also found a variety of amines, which are used to create amino acids, the building blocks of life. One test even generated a type of amino acid, called glycine, which is commonly found in proteins.

The study shows how conditions on the Earth 4 billion years ago may have spurred amino acid synthesis, or production. Scientists say the study sheds new light on how and when organic molecules appeared on the young Earth. Previous studies have hinted that lightning striking Earth’s ancient atmosphere could have generated organic molecules necessary for life as well. And such studies have also suggested that the chemical reactions around deep-sea hydrothermal vents — where water heated inside the Earth is expelled from cracks in the sea floor — could have produced these molecules.

source : http://www.sciencenewsforkids.org

Earth from the inside out

Originally used to detect elusive particles from space called neutrinos, the four-story detector at the Sudbury Neutrino Observatory could be retrofitted to detect antinutrinos produced by natural radioactivity inside Earth.

Courtesy of Lawrence Berkeley National Laboratory

Scientists have long known this strange fact: It’s easier to look deep into space than into the center of Earth. Light can pass through most of space, so the light from distant stars can easily be seen with the naked eye. But Earth is opaque, which means that light cannot pass through it.

If light cannot pass through it, then we cannot see what’s on the inside of our planet. So if we can’t use light to see inside our own planet, what can we use?

Recently, some scientists have been trying to use neutrinos — tiny particles smaller than an atom that zip through space. Neutrinos come from the sun or other distant stars, and astronomers have studied them for years. Now, a team of geoscientists — “geo” means Earth — think a kind of neutrino may have something to say about the Earth, too.

Not all neutrinos come from outer space. Special neutrinos called geoneutrinos are generated from within the Earth. (Remember that “geo” means Earth.) Most of these local neutrinos come from either the crust or the mantle. The crust is Earth’s outermost shell, what we stand on, and the mantle is five to 25 miles below the crust. Certain elements within the Earth can send off geoneutrinos when undergoing a process called radioactive decay.

During radioactive decay, a material loses some of its energy by sending out particles and radiation. An element that goes through this process is said to be radioactive, and radioactive elements occur naturally in the Earth. Some radioactive elements produce geoneutrinos.

After they are produced, geoneutrinos pass straight through the solid Earth without being absorbed or bouncing around. If they’re not stopped, they go straight into outer space — and keep going, and going and going. Geoscientists hope to catch a few of these particles on their way out, but it’s not going to be easy.

There are two big problems: There aren’t that many geoneutrinos, and they’re hard to find. To catch these elusive particles, scientists have designed special geoneutrino detectors. These strange-looking scientific instruments are giant, metal spheres buried deep underground.

In an abandoned mine in Canada, for example, scientists are preparing a geoneutrino detector that is four stories tall and more than a mile underground. The detector will be filled with a special liquid that flashes when a geoneutrino passes through. The liquid “produces a lot of light, and it’s very transparent,” says Mark Chen, the director of the project. When it’s up and running, probably in 2010, the detector will find only about 50 geoneutrinos per year. Other detectors are being planned all over Earth — one of them is even supposed to sit on the bottom of the ocean!

The geoscientists who study geoneutrinos hope that the particles will help answer an old question about the Earth. The interior of the Earth is blistering hot, but where does the heat come from? They know that part of the heat — maybe as much as 60 percent — comes from radioactive decay, but researchers want to know for sure. By measuring geoneutrinos, scientists hope to figure out how radioactive decay helps heat Earth.

source : http://www.sciencenewsforkids.org

Invisible fossils of the first animals

This stone core was drilled from an ancient seabed that now lies nearly 3 miles underground. The dark color comes from oil left behind by bacteria and animals that lived over 500 million years ago. The white color comes from salt left behind by the sea.

Petroleum Development Oman

Gordon Love walked past the warm waters of the Arabian Sea as they lapped on a white sandy beach in the country of Oman. He entered a metal warehouse and walked past row after row of hallways lined with sliding metal doors. Some of these doors concealed an important piece of history.
Love, a geochemist now at the University of California, Riverside, had come to the Middle East to work for an oil company for a couple of weeks. But this trip would also give him a rare chance to look at rocks from deep inside the Earth. It would lead him and his partners to a major new discovery about early life on our planet.
Behind each one of the warehouse’s metal doors lay a cylinder of stone about the width and length of a baseball bat. You might call this warehouse a library of both rocks and history. These cylinders of stone — called cores — were drilled from the flat and dusty deserts of Oman by people looking for oil. The stone cores were lifted out of drill holes that reach three miles underground. Those drill holes pierced through layer after layer of petrified mud, which contained once-living material that turned into rock over time. This mud collected over millions of years on an ancient sea bed. You can see the layers as stripes of gray, white and brown stone in the cores. If you stacked these cores end to end they would run for miles — and they would tell the history of this ancient sea now buried beneath the desert.
Love entered a room where dozens of sections of core were laid out on tables. He could tell from the brown color of the stone that it still contained tiny bits of oil. That brown stone was just what he was looking for.

Scientist Gordon Love looked at molecular fossils in rocks as deep as 3 miles underground, similar to the dark ones shown here in the desert of Oman.

David Fike, Washington University

Molecular fossils
Oil doesn’t just fuel cars, trucks and airplanes. It also contains a record of the past. Oil contains chemical traces of things that lived hundreds of millions of years ago. Scientists call these chemicals “molecular fossils.” They can exist even when more obvious fossils, like the imprints of leaves or seashells pressed into rocks, do not survive the extreme heat and pressure of being buried deep in the Earth.
By studying the molecular fossils in the cores lifted from drill holes, Love and his colleague, Roger Summons of the Massachusetts Institute of Technology (MIT), have found evidence of animals that lived as long as 751 million years ago.
“At present it’s the oldest fossil evidence for animals,” says Love. In fact, it’s up to 176 million years older than any other animal fossils that scientists have found.

This 550 million-year-old fossil from Australia may be the oldest fossil imprint of a sponge.

James Gehling, South Australia Museum in Adelaide

The animals that Love found may have been some of the first on Earth. Human eyes have never seen these animals and have never even seen the faint shapes that they left pressed between rocks. The tortures of the deep Earth have long since erased those shapes. But by studying the invisible molecular fossils left behind by these animals, Love and Summons can not only tell that these creatures lived — they can actually make some guesses about what they looked like.
Greasy black tar
Oil forms over millions of years as dead plants, animals and bacteria are buried beneath sand or mud and decompose deep underground. Most of the grease seeps out of rocks and drains into spaces underground where it collects in large pools — the places where oil companies like to aim their drills. This oil in Oman is the oldest oil that companies have ever tried to drill out of the ground and turn into gasoline. This oil came from bacteria, algae and other critters that lived in an ocean over 500 million years ago.
The kind of molecular fossil left behind depends on the kind of organism decomposing. Bacterial molecular fossils look different from those fossils left behind by animals, for example. By studying such fossils, Summons and Love hoped to find out what kinds of things were living in the ocean when the rocks formed.

This adult sponge, about the size of a fist, was found in ankle-deep water in the Great Barrier Reef off Australia's coast.

Sally Leys, University of Alberta, Edmonton)

In the warehouse that day, Love sawed some marble-sized chunks of rock out of the cores. The rock was as hard as cement. He took his little pieces of rock back to Summons’ lab in Cambridge, and crushed them into dust. He cooked the dust in acid until he was left with a glob of greasy black tar — the remains of ancient dead things.
Love spent another two weeks purifying, or removing unwanted material from, this tar until he held in his hand a test tube of colorless liquid. That liquid contained the molecular fossils that he and Summons wanted to analyze. The molecular fossils were invisible to the eye. A person might not even taste the small amounts of them in the tube. But Love could detect the fossils using a refrigerator-sized machine called a GC-MS, or gas chromatograph mass spectrometer.
Love loaded a few drops of the liquid into the GC-MS and watched the computer screen as the machine analyzed the dozens of chemicals.

Shown is the larva, or young, of the same species of sponge pictured as an adult. About the size of a grain of salt, this tiny creature was seen through an electron microscope.

Sally Leys, University of Alberta, Edmonton)

Blobby sponges
If you’ve ever been in a hospital or seen a hospital show on TV, then maybe you’ve seen the bright line that moves across a heart monitor, tracing out jagged peaks and dips every time a person’s heart beats. Love saw something like this as he watched the GC-MS analyze the molecular fossils. A line running across the computer screen traced out a sharp spike every time the machine detected another chemical.
As Love sat and watched, one of those spikes grabbed his attention: It stood for a chemical called 24-isopropylcholestane, or 24-ipc. Love had seen 24-ipc in rocks before — it’s a well-known chemical — but seeing it in these old rocks from Oman was a big deal.
Scientists consider 24-ipc to be a molecular fossil that comes from animals called sea sponges. Scientists have looked at various animals, fungi and bacteria that live on Earth today to see which chemicals they produce. Researchers have found that sponges produce large amounts of a chemical closely related to 24-ipc. During heating, such as that deep inside the Earth, this chemical slowly changes into 24-ipc. “Sponges are the only organisms that produce it in any significant quantities,” says Love.
Sea sponges are cigar- or balloon-shaped animals that sit on the seafloor. They eat by filtering bacteria and other tiny organisms out of the water. You wouldn’t exactly call sea sponges smart. They have no brains, no eyes, no legs and no fins. They’re some of the simplest animals on Earth. Some biologists think sponges were the first animals to evolve, or develop from simpler, single-celled organisms through a process of gradual change over millions of years. So when Love saw 24-ipc in the oil from these old rocks, he knew it was important.
The oldest known sea sponge fossils that you can see with the naked eye are cup-shaped imprints found in 550-million-year-old rocks. Scientists have also seen blobby imprints, like round, quilted pillows, in rocks as old as 575 million years. (Though some scientists believe that many of these older animal fossils aren't related to modern animals.) Researchers think these imprints were probably made by some kind of animal — although the blobs are so strange, they don’t know what kind of animal. But the molecular sponge fossils that Love had just found were much older than any of those shapes in the rocks. Judging from the age of the rocks from Oman he tested, these sea sponges are at least 635 million years old, and maybe as much as 751 million years old.
A big disagreement
These findings by Love, Summons, David Fike of Washington University in St. Louis, and nine other scientists will be published on February 5 in a major scientific journal called Nature. Their discovery has a lot of people excited. These new molecular fossils may help to solve a big disagreement about the earliest animals on Earth.
In other studies, biologists have compared the DNA, a molecule that holds an organism’s genetic information, of different animals alive today, such as sponges, clams, insects, worms, mice and humans. Scientists have done this in order to estimate how long ago the first animals lived. These “molecular clock” calculations say that the first animals evolved somewhere between 650 and 950 million years ago. And yet the oldest fossil imprints of animals are only 575 million years old.
That disagreement between the dates from the fossil imprints and the dates from the molecular clocks caused some scientists to wonder whether the molecular clock calculations were wrong. But by showing molecular fossils of animals maybe as old as 751 million years, Summons and Love’s new findings have something to say about that disagreement. “I think this new work is both important and believable,” says Andrew Knoll, a paleontologist who studies early fossils at Harvard University. “This goes a long way toward reconciling the geologic record with molecular clock estimates.”
Swimming in the early oceans
It makes sense that the first animals might have been sponges or something like them. All animals, whether they live in water or on land, need to breathe oxygen; without it, they suffocate. But 600 or 700 million years ago the Earth hadn’t yet filled up with oxygen the way it has today. The oceans probably contained oxygen in their shallowest parts, but the deeper waters likely contained hardly any oxygen.
This is one reason why it makes sense that sponges are the first animals, says Kevin Peterson of Dartmouth College in Hanover, N.H. “Sponges have exceedingly low metabolism,” he says, meaning that some kinds of sponges consume oxygen slowly compared to other animals, and so such sponges can tolerate lower levels of oxygen.
Even if these ancient animals were closely related to modern-day sponges, Knoll isn’t willing to say whether these early animals actually looked like the same big cigar-shaped sponges that we see in our oceans today.
It’s true that adult sponges are big balloons which sit on the sea floor and suck food out of the water. But young sponges, called larvae, look very different. They are tiny — about the size of a grain of sand. And rather than sitting on the ocean bottom, they swim through the water by whipping around tiny oars on their body that look like hairs.
The animals that Love detected could have looked more like tiny larvae than big adult sponges. “If you had been swimming in the same ocean, you might not have noticed them,” says Knoll.


source : http://www.sciencenewsforkids.org

Science loses out when ice caps melt

At left is Peru’s Qori Kalis glacier in 1978, when it was still healthy. At right is the much-reduced glacier in 2000. A lake of meltwater now occupies what 22 years earlier had been a deep field of flowing ice.

Ohio State Univ.

It’s hard to imagine a mountain range without snow-covered peaks. But that may soon be the case in countries in or near the tropics. Studies show that the ice that sits atop the world’s highest mountains is vanishing at an alarming rate, threatening to leave the summits bare.

The accelerated melting of these glacial caps is visible evidence that Earth is getting warmer, scientists say. Most of Earth's glaciers have been shrinking for decades as our climate has been warming from natural causes and human activity.

Although Earth’s atmosphere is warming nearly everywhere, the greatest warming has been taking place at high elevations and in tropical portions of the world, says Lonnie Thompson, a glaciologist — or scientist who studies glaciers — at Ohio State University. In very high tropical glaciers, temperatures have been warming at three times the speed of increases at ground level.

Most mountain peaks are high enough that the snow that falls onto them will stay frozen year-round. That’s because air at high altitudes is less dense and holds less heat. As the snow piles higher and higher, the bottom layers become compressed into ice, forming a glacier — a slowly moving river of ice.

For scientists, the real beauty of glaciers is that there’s so little melting. A year’s worth of snow can be crunched down to form an annual layer that normally survives hundreds — if not thousands — of years. Essentially the deeper you probe down into a glacier’s ice, the farther back in time you get.

The black line in this glacial core collected atop Mt. Kilimanjaro corresponds to a prolonged deposition of dust 4,200 years ago that likely represents 300 years of drought.

J. Raloff

Those annual ice layers — “they’re like tree rings,” says Thompson, who has traveled the world, measuring the shriveling snowcaps atop some of the world’s highest mountains. His studies show that the huge Quelccaya (kal KI’ yah) Ice Cap, a tropical glacier that stretches across the Peruvian Andes, is shriveling by about 18 inches a day.

“You can almost sit there and watch it lose ground,” Thompson says.

Another glacier — one that sits atop Mount Kilimanjaro in Tanzania — has been melting steadily for nearly 100 years and has lost 84 percent of its ice.

Like tree rings, the layers found in glaciers also have an important story to tell. Because snowpacks absorb chemicals, pollen and dust from the atmosphere, the ice masses that sit atop mountains have been collecting data about the climate for centuries or more.

As these ice caps rapidly disappear, they are taking their historical records with them. Losing data of this type means losing some important history about the long-lasting impacts of natural climate, Thompson says.

He and his colleagues have been busy drilling into the snow-covered mountain tops to obtain ice cores before the rate of melting causes these records to vanish. To date they have preserved some 7,000 ice cores. One ice core from Mount Kilimanjaro contains climate data going back 11,700 years. That’s longer than any documented history.

These ice cores can tell scientists about the role that climate played in the rise and fall of cultures throughout history. The core sampled atop Mt. Kilimanjaro, for example, shows a three-millimeter-thick band of black dust. It initially settled onto the snowpack some 4,200 years ago. This date corresponds to archaeological records showing a 300-year drought in Egypt.

Thompson and others believe that the history preserved in the ice cores may also help foretell Earth’s future climate. For example, data from the glaciers offers clues as to how past temperature changes affected El Niños, the atmospheric-oceanic disturbances that hit the central West Pacific every few years. Studies of these data may help scientists predict how droughts and floods caused by an El Niño might grow as the world warms in decades to come.

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Going Deeper:

Polar Ice Feels the Heat http://www.sciencenewsforkids.org/articles/20080423/Feature1.asp

Earth's Poles in Peril http://www.sciencenewsforkids.org/articles/20070530/Feature1.asp

Life trapped under a glacier

Iron in water seeping from an underground ecosystem takes on a rusty color as it is exposed to air. Surprisingly hearty life forms use iron and sulfates, instead of oxygen, to live in their long-isolated, dark and salty home.

B. Urmston

Ever heard of Blood Falls? It’s freezing cold, far away and hard to reach — probably not where you’re headed on your family vacation this summer.
Blood Falls is at the tip of a giant glacier in Antarctica. As its name suggests, the icy face of Blood Falls is red — but not from blood. Instead the water gets its hue because it’s rich in iron. When the water trickles out from its underground beginnings, the iron is exposed to oxygen in the air and quickly forms the red rust.
It may not be a tourist hot spot, but Blood Falls is very interesting to scientists who study living creatures. A geomicrobiologist — someone who studies how tiny organisms affect or use minerals — recently studied the rusty water and came up with some surprising results.
The water that feeds Blood Falls probably comes from a salty underground lake. It’s home to microbes that surprisingly don’t need oxygen to survive. Microbes are tiny organisms, usually invisible to the naked eye. The microbes found in Blood Falls are similar to other microbes that live in the ocean.

“This briny pond is a unique sort of time capsule,” says Jill Mikucki, the Dartmouth University geomicrobiologist who led the study of the water seeping from Blood Falls. “I don’t know of any other environment quite like this on earth.”
When she and her team studied the water, they found no oxygen but lots of dissolved iron. They suspect that the underwater reservoir formed when a giant glacier, now 1,300 feet thick, moved over the salty lake at least 1.5 million years ago. This trapped the water and everything in it in an oxygen-free, or anoxic, environment.
Unlike human beings and most other forms of life, the microbes from Blood Falls don’t need oxygen to live. Instead, they are able to exist using the iron and sulfates, chemical salts also found in the water. The microbes transfer particles called electrons from the sulfates to the iron.
The microbes at Blood Falls show that life can exist in even the harshest environments. In addition to giving us more information about our own planet, the study of these “extremophiles” may be useful in other scientific areas — like the search for life on other planets! If scientists find organisms on Earth that live on sulfur and iron, instead of oxygen, researchers might gain a better idea of where to look for life elsewhere in the universe.

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Power words: (Yahoo! Kids Dictionary and WordNet)
microbe: A tiny life form; a microorganism, especially a bacterium that causes disease.
iron: A silvery-white, magnetic, metallic element occurring abundantly in combined forms. Used in a wide range of important structural materials.
sulfate: A chemical compound made from sulfur.
anoxic: A severe lack of oxygen

source : http://www.sciencenewsforkids.org

Flower family knows its roots

Yellow jewelweeds, wildflowers that grow along shady watersides in eastern North America, apparently can recognize their siblings as long as roots share soil.

pellaea/Flickr

Jewelweeds, or Impatiens, are pretty flowers that grow in wet, shady spots all over the Northern Hemisphere. According to a recent experiment, they seem to know their own flower family.
The experiment suggests that these flowers can recognize each other—or at least, recognize whether or not they came from the same mother plant. Together with other experiments, these results show that if the plants are recognizing their kin, it’s not through their leaves, it’s through the roots.
Guillermo P. Murphy and Susan Dudley are a pair of botanists, or scientists who study plants, from McMaster University in Hamilton, Canada. In this experiment, they planted jewelweeds in pots with either siblings or strangers. Sibling plants were grown from seeds that came from the same mother plant. Stranger plantswere grown from seeds from different plants.
If people were plants, then this experiment would be like showing that a person behaves differently if he grows up next to his brother than if he grows up next to a stranger.
When jewelweeds were planted in pots with strangers, the plants started to grow more leaves than if they had been planted alone. This response suggests that plants are competing with strangers for sunlight, since a plant with more leaves can receive more light—and make more food. Impatiens normally grow in the shade, where sunlight is scarce.

Researchers grow jewelweed seedlings in tall pots to test for effects of growing near siblings or non-siblings. Plants react mildly to siblings but start shifting their resources to leaf warfare when surrounded by strangers, researchers found.

G. Murphy

When jewelweed seedlings were planted with siblings, they grew a few more branches than they normally would if they were alone — but they did not start growing lots of extra leaves. This behavior suggests the plants are more likely to share resources, rather than compete.
The plants only responded this way when they shared soil. If stranger seedlings were planted in different pots and placed next to each other, for example, they did not grow more leaves. This difference shows that the plants must use their roots to detect sibling plants in the same soil.     
“This is the first paper that shows that plants are responding above ground to sibling roots,” Murphy told Science News.           
Impatiens plants are not the first plants that botanists have studied for family recognition. In 2007, Dudley and her team studied the Great Lakes sea rocket, a plant that grows on the beach—where it may be hard to get fresh water. In that experiment, the botanists observed that when sea rockets were planted with siblings, they tolerated each other. But when they were planted with strangers, the sea rockets reacted by working extra hard to grow lots of roots, but not extra leaves. Dudley says this behavior makes sense because sea rockets, on the beach, get plenty of sun but struggle for water—so when they’re threatened, they compete for water. Impatiens, on the other hand, have plenty of water but have to compete for sunshine.
The different types of plants may react in different ways, but they have one thing in common: the roots. In both experiments, on Impatiens and sea rockets, the key was the shared soil—and other plant species may turn out to show similar behavior. These experiments, as well as earlier experiments, suggest “the phenomenon is quite common," says Hans de Kroonof, an ecologist in the Netherlands.

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POWER WORDS (from the Yahoo! Kids Dictionary)
seedling A young plant that is grown from a seed
botany The science or study of plants
ecology The science of the relationships between organisms and their environments
impatiens   Any of various plants of the genus Impatiens, which includes the jewelweed.

source : http://www.sciencenewsforkids.org

A global warming flap

Two butterfly species, the small heath (left) and common blue (right), are among those in Central Europe that have become more likely in the last 30 years to have an extra generation in the same year. Since 1980, average temperatures there have also risen.

F. Altermatt

Florian Altermatt likes to chase butterflies, but he’s also a scientist who thinks that butterflies might have something to tell us about the effects of global warming.

Altermatt is an ecologist — a scientist who studies how creatures interact with their environment — who works at the University of California, Davis. In a new study, he and other researchers looked at changes in the reproduction patterns of butterflies and moths in Central Europe.

Over the last 30 years, the average temperature in Central Europe has gone up about 1.5 degrees Celsius. During that same time, 44 species of moths and butterflies in an area around Basel, Switzerland, have added an extra generation to their numbers during some years, Altermatt found. That means that if butterflies of one of these species used to reproduce once per year, they now sometimes reproduce twice. And if they used to reproduce twice, they now sometimes reproduce three times. These extra generations didn’t show up in this location before 1980.

The temperature increase, 1.5 degrees, may not seem like much, but it’s about the difference between the body temperature of a healthy person and someone with a low-grade fever. Altermatt suspects that in Central Europe, that extra degree and a half is changing the internal clocks of many kinds of butterflies and moths. Because it’s warmer outside, their breeding season begins earlier, for example, giving the insects more time to mate. Altermatt also says that the increase in temperature speeds up the development of the insects, so they’re ready to reproduce earlier in their lives.

This was no small study: He and his colleagues watched butterflies and moths outdoors and also looked at historical records for more than 1,100 types of the creatures. Of those species, 263 are known to produce one or two extra generations in the location studied — but not always; only when the temperatures heat up. Altermatt found, however, that since 1980, a majority of those species started adding generations more often.

These added insects might mix things up in the ecosystem of Central Europe, says Patrick Tobin, an ecologist who works for the U.S. Forest Service in Morgantown, W.Va. An extra generation of insects provides more food to the animals that feed on them. Those predators, in turn, might start to increase their numbers, which would make life tougher on the other species the predators eat, Tobin told Science News. On the other hand, with an extra generation, an endangered insect species might have a better chance of recovering.

Altermatt also does research in evolution, which is the study of how species, or groups of the same creature, change over time. Every time an insect — or animal, plant or other organism — reproduces, the offspring might be slightly different from its parent. These differences could give the offspring a better chance of survival in the world. In this case, Altermatt thinks the additional butterfly generations may speed up evolution — and perhaps give them a better chance of survival in the face of climate change. On the other hand, maybe these changes won’t make a difference: Altermatt doesn’t know whether the extra generations of butterflies and moths survived.

Scientists who study the effects of climate change like to look at patterns such as insect populations because they are easy to track — and easy to connect to a warming world. And by studying such visible effects of climate change, scientists might be able to better predict the changes ahead for other populations — like humans.

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POWER WORDS (adapted from the Yahoo! Kids Dictionary and the Yale-New Haven Teachers Institute)

biological evolution The process of physical change in living things across generations.

ecology The science of the relationships between organisms and their environments.

global warming An increase in the average temperature of the Earth’s atmosphere, especially a continued increase sufficient to cause climate change.

species A category of classification of living things, ranking below a genus or subgenus in standard biological classification, and consisting of related organisms capable of interbreeding.

reproduce To generate offspring by sexual or asexual means.

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Going Deeper:

Milius, Susan. 2009. “Warming has already boosted insect breeding,” Science News, Dec. 24. Link

Visit Florian Altermatt’s website to see pictures of butterflies and learn more about his work with butterflies here.

Sohn, Emily. 2005. “A butterfly’s electric glow,” Science News for Kids, Nov. 30. Available online here.

Surprise Visitor

Réunion is an island of surprises. It is French, but it’s nowhere near France — it’s off the east coast of southern Africa. After dark on this island, scientists use night-vision cameras to spy on the flowers. They want to learn more about pollination, which is how many plants reproduce. A plant becomes pollinated when pollen, which looks like powder, is moved from the male to the female part of the plant.
And now for the strange part: While watching an orchid at night, these researchers recently filmed a new kind of cricket — one never before reported by scientists. Not only was the cricket new, but it was doing something never observed in any kind of cricket: It was pollinating the orchid. The scientists, who are from France and England, reported on the new cricket — and its new behavior — in a recent paper.

View video | This cricket species is the first insect of its kind known to pollinate flowers.

Sylvain Hugel

Claire Micheneau, who worked on the study, is finishing her Ph.D. at a university on Réunion. (A Ph.D., also known as a doctorate, is an advanced academic degree. University professors in the sciences usually have earned a Ph.D.) “This was very unexpected,” says Micheneau, who worked with scientists from the Royal Botanic Gardens, Kew in England. “The answer to a question brings us further questions.” Scientists would like to know, for example if cricket pollination is more common than they thought.
Micheneau and her colleagues weren’t looking for crickets. They wanted to know how an orchid called Angraecum cadetii becomes pollinated, so they aimed their night-vision cameras at the flowers and hit the “record” button. For a flower to make seeds that can grow into new plants, the flower needs to be pollinated: Pollen from the male part of a flower has to land on the female part of the flower, the stigma. Wind might help the pollen get there—or bugs like bees and butterflies, or birds, might. Surprisingly, in recent years scientists have even seen lizards and cockroaches carrying pollen from flower to flower. But never have they seen crickets doing so — until now.
When the scientists watched the movies they recorded, they saw a cricket moving away from an orchid with pollen on its head. They considered that maybe this was one strange cricket, so they set up the experiment again and recorded that type of orchid for many hours. Over and over, they saw the same thing: Crickets were pollinating the flowers.
W. Scott Armbruster, a scientist at the University of Alaska in Fairbanks, says if flowers are growing far from where they originated, they might attract strange pollinators — like crickets or lizards. (Armbruster did not work on the orchid study.) This orchid, for example, probably originated on the nearby island of Madagascar but at some point migrated across the water.
The orchid and this type of cricket seem made for each other. The orchid gives off its sweet smell at night, when the crickets are out — and can snack on the orchid’s delicious nectar. This cricket is particularly good at finding its way around every night, so it could easily find the orchids in the dark and remember where to find them later. “It was the right orchid and the right cricket,” Armbruster told Science News.
Armbruster notes that the word biodiversity usually refers to a list of all the different kinds, or species, of organisms that exist in a place — so the biodiversity of Réunion would include both the orchids and the crickets. He says that should change: “We tend to think of biodiversity in terms of lists of species, but it is actually lists of interactions”—meaning the relationships between different species like the orchid and the cricket.
The French word reunion means “meeting” — which seems fitting for this pair. The meeting of the cricket and the orchid may be a surprise, but it’s no surprise to scientists that different species are so strongly connected and depend on each other for survival.

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POWER WORDS (adapted from the Yahoo! Kids Dictionary)
pollinate To transfer pollen from an anther to the stigma of a flower.
orchids The largest family of flowering plants, found chiefly in the tropics and subtropics and characterized by showy flowers, strong relationships with pollinators and dustlike seeds.
biodiversity The number and variety of organisms found within a geographic region; also, arguably, the number of interactions among organisms.
species A fundamental group of organisms capable of interbreeding.
anther The pollen-bearing part of the stamen (the organ that produces the pollen).
stigma The receptive portion of a flower where pollen is deposited at pollination.
pollen The fine, powderlike material consisting of pollen grains, which is produced by the anthers of seed plants.

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Cricket Takes Plunge? from Science News on Vimeo.
A new species of raspy cricket is caught on film pollinating the Réunion island orchid Angraecum cadetii. It is the first documented instance of flower pollination by a cricket.

Video credit: Claire Michenau and Jacques Fournel

source : http://www.sciencenewsforkids.org