WILL HEATING A JAWBREAKER MAKE IT EXPLODE?

Finding: BUSTED

Explanation: As part of their crime movie experiment extravaganza, the MythBusters unlocked the answer to whether you could open a safe simply by listening to it, as seen in so many spy flicks. Supposedly, the key to cracking a safe by sound is in listening closely for the combination that causes the lock wheels to click into place. So, equipped with an amplifying stethoscope to help detect any internal noises, Adam Savage took a crack at cracking a safe. With his ear pressed to the souped-up stethoscope, Adam turned the safe's lock to find the combination that clicks the lock wheels into place. But after 20 minutes of trying, Adam didn't hear a single peep from the safe. Since he was able to open the safe only after drilling a hole into the safe's locking mechanism to see how the gears turned, the only facade Adam really broke through (without the help of a power tool) was that of the busted movie myth.

As seen in "MythBusters: Crimes and Myth-Demeanors."

IS IT POSSIBLE TO PICK A SAFE BY LISTENING TO THE LOCK CLICKS?

Finding: CONFIRMED

Explanation: Jawbreaker candies have a not-so-sweet reputation for inflicting bodily harm. Around the country, police reports detail incidents of the gobstoppers exploding in — and on — kids' faces, leaving severe burns. But why would these confections turn so sour? MythBusters Jamie Hyneman and Adam Savage noticed that many of the injured kids first heated their jawbreakers in the microwave, and when they bit or licked them afterward, the candy blasted open. Slicing a jawbreaker opens reveals why the microwave might aggravate that cement-like sugar. The candies are formed from multiple layers of sugary syrup surrounding a solid candy core encased in a hard outer shell. That jawbreaker architecture can cause a temperature differential, meaning that the internal layers can heat up faster than the outer ones. For that reason, when the MythBusters tossed some jawbreakers into a microwave, then crunched the hot candy in a pair of steel jaws, the molten insides spewed out. As a painful confirmation to the myth, the 225-degree gobstopper goop scorched Jamie's unprotected arm.

As seen in "MythBusters: Exploding Jawbreaker"

How Our Brains See Men as People and Women as Body Parts: Both Genders Process Images of Men, Women DifferentlyScienceDaily (July 25, 2012) — When casting our eyes upon an object, our brains either perceive it in its entirety or as a collection of its parts. Consider, for instance, photo mosaics consisting of hundreds of tiny pictures that when arranged a certain way form a larger overall image: In fact, it takes two separate mental functions to see the mosaic from both perspectives.

A new study suggests that these two distinct cognitive processes also are in play with our basic physical perceptions of men and women -- and, importantly, provides clues as to why women are often the targets of sexual objectification.The research, published in the European Journal of Social Psychology, found in a series of experiments that participants processed images of men and women in very different ways. When presented with images of men, perceivers tended to rely more on "global" cognitive processing, the mental method in which a person is perceived as a whole. Meanwhile, images of women were more often the subject of "local" cognitive processing, or the objectifying perception of something as an assemblage of its various parts.The study is the first to link such cognitive processes to objectification theory, said Sarah Gervais, assistant professor of psychology at the University of Nebraska-Lincoln and the study's lead author.

"Local processing underlies the way we think about objects: houses, cars and so on. But global processing should prevent us from that when it comes to people," Gervais said. "We don't break people down to their parts -- except when it comes to women, which is really striking. Women were perceived in the same ways that objects are viewed."In the study, participants were randomly presented with dozens of images of fully clothed, average-looking men and women. Each person was shown from head to knee, standing, with eyes focused on the camera.After a brief pause, participants then saw two new images on their screen: One was unmodified and contained the original image, while the other was a slightly modified version of the original

image that comprised a sexual body part. Participants then quickly indicated which of the two images they had previously seen.The results were consistent: Women's sexual body parts were more easily recognized when presented in isolation than when they were presented in the context of their entire bodies. But men's sexual body parts were recognized better when presented in the context of their entire bodies than they were in isolation.

"We always hear that women are reduced to their sexual body parts; you hear about examples in the media all the time. This research takes it a step further and finds that this perception spills over to everyday women, too," Gervais said. "The subjects in the study's images were everyday, ordinary men and women … the fact that people are looking at ordinary men and women and remembering women's body parts better than their entire bodies was very interesting."Also notable is that the gender of participants doing the observing had no effect on the outcome. The participant pool was evenly divided between men and women, who processed each gender's bodies similarly: Regardless of their gender, perceivers saw men more "globally" and women more "locally.""We can't just pin this on the men. Women are perceiving women this way, too," Gervais said. "It could be related to different motives. Men might be doing it because they're interested in potential mates, while women may do it as more of a comparison with themselves. But what we do know is that they're both doing it."

Would there be an antidote to a perceiver's basic cognitive processes that lead women to be reduced and objectified? Researchers said some of the study's results suggested so. When the experiment was adjusted to create a condition where it was easier for participants to employ "global" processing, the sexual body part recognition bias appeared to be alleviated. Women were more easily recognizable in the context of their whole bodies instead of their various sexual body parts.Because the research presents the first direct evidence of the basic "global" vs. "local" framework, the authors said it could provide a theoretical path forward for more specific objectification work."Our findings suggest people fundamentally process women and men differently, but we are also showing that a very simple manipulation counteracts this effect, and perceivers can be prompted to see women globally, just as they do men," Gervais said. "Based on these findings, there are several new avenues to explore."

Story Source:The above story is reprinted from materials provided by University of Nebraska-Lincoln, via EurekAlert!, a service of AAAS.Note: Materials may be edited for content and length. For further information, please contact the source cited above.Journal Reference:Sarah J. Gervais, Theresa K. Vescio, Jens Förster, Anne Maass, Caterina Suitner. Seeing women as objects: The sexual body part recognition bias. European Journal of Social Psychology, 2012; DOI: 10.1002/ejsp.1890

http://www.sciencedaily.com/releases/2012/07/120725150215.htm

In a new study that examined our cognitive process in how we perceive men and women, participants saw a fully clothed person from head to knee. After a brief pause, they then saw two new images on their screen: One that was unmodified and contained the original image, the other a slightly modified version of the original image with a sexual body part changed. Participants then quickly indicated which of the two images they had previously seen. They made decisions about entire bodies in some trials and body parts in other trials. (Credit: University of Nebraska-Lincoln)

This may put a damper on warm-weather grilling, but a new study suggests a daily serving of processed red meat was associated with a 20 percent increased risk of dying during the study period.

Red Meat a Ticket to Early Grave, Harvard SaysBy: Christopher Wanjek, LiveScience Bad Medicine Columnist

12 March 2012-Just in time to spoil the promise of warm-weather picnics, Harvard scientists have found that daily consumption of red meat — particularly the kind you might like to grill — may significantly increase your risk of premature death.

While this much has long been suspected, perhaps even by you, the Harvard-led study is the first nuanced analysis to calculate the risk that a serving of red meat can have on your longevity compared with other protein sources.

The study measures, for example, how much one could expect to lower their risk of early death by replacing pork and beef with poultry, fish, nuts or beans can lower the risk of early death; they found chicken was at least as healthy an alternative to red meat as beans and whole grains.

"This paper does not give a green light to a low-fat, high-carb diet," senior author Frank Hu of Harvard School of Public Health (HSPH) told LiveScience. "Instead, it underscores the importance of types or quality of protein."

The study was published today (March 12) online in the journal Archives of Internal Medicine.

120,000 people can't be wrongThe researchers, led by An Pan at HSPH, tapped into two longitudinal health studies — the Health Professionals Follow-Up Study, and the Nurses' Health Study — which capture health and dietary information from approximately 120,000 adults who were free of cardiovascular disease and cancer at the onset of the study and followed for up to 28 years.

For these subjects, 20 percent of whom died during the study, one daily serving of unprocessed red meat such as steak or pork chops was associated with a 13 percent increased risk of dying during the study. One daily serving of processed red meat, such as a hot dog or bacon, was associated with a 20 percent increased risk.

Conversely, replacing one serving of red meat with one serving of a healthy protein source was associated with a lower mortality risk: 19 percent lower when the meat was replaced with nuts; 14 percent for poultry; 14 percent for whole grains; 10 percent for legumes; 10 percent for low-fat dairy products; and 7 percent for fish.

"This study provides clear evidence that regular consumption of red meat, especially processed meat, contributes substantially to premature death," said Hu.

Low-carb vs. low-fat?

This same group of researchers reported last year that a daily serving of cold cuts or hot dogs was associated with a 50 percent increased risk of developing diabetes. Yet the researchers are not anti-meat, per se.

Missing entirely from the new Harvard study is the word "carbohydrate." The study merely looked at different forms of protein sources and found beef and pork to be unhealthier compared with other sources. Both Hu and co-author HSPH colleague Walter Willett have said that added sugar in drinks and in snack foods as well as the simple carbohydrates found in potatoes, white flour and processed foods are the primary causes of obesity and diabetes.

Also, their previous studies have found that a moderately low-carbohydrate diet that includes healthy sources of fat and protein — such as olive oil, nuts, poultry, fish, whole grains and legumes — can better lower the risk of premature death from cardiovascular disease than low-fat, high-carb diets.

Therefore, if you go (or stay) in the low-carb direction, Hu advises that you choose your fats and proteins carefully. "All low-carb diets are not created equal," nor are high-carb diets, he said.

Ornish vs. Atkins?Nevertheless, Dean Ornish, a leading supporter for a low-fat, plant-based diet naturally high in complex carbohydrates, was thrilled with the Harvard study results and wrote an adjoining commentary.

"What we include in our diet is as important as what we exclude, so substituting healthier foods for red meat provides a double benefit to our health," Ornish wrote in the commentary. "We have a spectrum of choices; it's not all or nothing."

For Ornish, those choices would be everything he has advocated for years: the complex, "good" carbs found in whole grains, beans and other vegetables; the "good" omega-3 fats found in some fish and in flaxseed; and protein from beans, nuts, whole grains and fish.

Ornish's gleeful commentary aside, the new Harvard study isn't a complete assault on the Atkins' diet and similar meat-heavy, low-carb diets. Any diet loaded with hamburger, bacon and sausage can lead to premature death, the study reveals, but poultry appears to be at least as healthy an alternative as beans and whole grains.

So what is it about red meat that makes it unhealthier than other protein sources? The Harvard scientists aren't sure. The saturated fat in red meat might not be the sole culprit, as long suspected, they said. The deleterious effects might be a result of the combination of heme iron (iron that comes from hemoglobin, the protein in red blood cells that delivers oxygen to our cells), sodium, nitrates and other chemicals that are created when cooking red meat ... in addition to, of course, all that delicious saturated fat.

Christopher Wanjek is the author of the books "Bad Medicine" and "Food At Work." His column, Bad Medicine, appears regularly on LiveScience.

http://www.livescience.com/18996-red-meat-premature-death.html

Milky Way Struck 100 Million Years Ago, Still Rings Like a BellScienceDaily (June 28, 2012) — An international team of astronomers have discovered evidence that our Milky Way had an encounter with a small galaxy or massive dark matter structure perhaps as recently as 100 million years ago, and as a result of that encounter it is still ringing like a bell.

The discovery is based on observations of 300,000 nearby Milky Way stars by the Sloan Digital Sky Survey (SDSS). Stars in the disk of the Milky Way move up and down at a speed of about 20-30 kilometers per second while orbiting the center of the galaxy at a brisk 220 kilometers per second. The positions and motions of these nearby stars weren't quite as regular as previously thought, according to the study results.

"We clearly observe unexpected differences in the Milky Way's stellar distribution above and below the Galaxy's mid-plane having the appearance of a vertical wave -- something that nobody has seen before," says Queen's University physicist Larry Widrow, lead researcher on the project.

The researchers have not been able to identify the celestial object that passed through the Milky Way. It could have been one of the small satellite galaxies that move around the center of our galaxy, or an invisible structure such as a dark matter halo. It might not have been a single isolated event in the past, and it may even be ongoing.

The researchers discovered a small but statistically significant difference in the distribution of stars north and south of the Milky Way's midplane when analyzing SDSS data. For more than a year, they explored various explanations of this north-south asymmetry but were unable to solve the mystery. So they began exploring whether the data was telling them something about recent events in the Galaxy's history.

Scientists know of more than 20 visible satellite galaxies that circle the center of the Milky Way, with masses ranging from one million to one billion solar masses. There may also be invisible satellites made of dark matter. There is six times as much dark matter in the universe as ordinary, visible matter. Astronomers' computer simulations have found that this invisible matter formed hundreds of massive structures that move around our Milky Way.

These dark matter satellites, because of their abundance, are more likely than the visible satellite galaxies to cut through the Milky Way's mid-plane and cause vertical waves.

Computer simulations indicate that over the next 100 million years or so, our galaxy will "stop ringing." The north-south asymmetry will disappear and the vertical motions of stars in the solar neighborhood will revert back to their equilibrium orbits unless we get hit again.

Collaborators on the project include Brian Yanny and Scott Dodelson (US Department of Energy's Fermilab), Susan Gardner, (University of Kentucky) and Hsin-Yu Chen (University of Chicago).Story Source:The above story is reprinted from materials provided by Queen's University. Note: Materials may be edited for content and length. For further information, please contact the source cited above.

Journal Reference:

1. Lawrence M. Widrow, Susan Gardner, Brian Yanny, Scott Dodelson, Hsin-Yu Chen. Galactoseismology: Discovery Of Vertical Waves In The Galactic Disk. The Astrophysical Journal, 2012; 750 (2): L41 DOI: 10.1088/2041-8205/750/2/L41

http://www.sciencedaily.com/releases/2012/06/120628174538.htm

Milky Way. An international team of astronomers have discovered evidence that our Milky Way had an encounter with a small galaxy or massive dark matter structure perhaps as recently as 100 million years ago, and as a result of that encounter it is still ringing like a bell. (Credit: NASA/JPL-Caltech).

Ions, Not Particles, Make Silver Toxic to Bacteria: Too Small a Dose May Enhance Microbes' ImmunityScienceDaily (July 11, 2012) — Rice University researchers have settled a long-standing controversy over the mechanism by which silver nanoparticles, the most widely used nanomaterial in the world, kill bacteria. Their work comes with a Nietzsche-esque warning: Use enough. If you don't kill them, you make them stronger.

Scientists have long known that silver ions, which flow from nanoparticles when oxidized, are deadly to bacteria. Silver nanoparticles are used just about everywhere, including in cosmetics, socks, food containers, detergents, sprays and a wide range of other products to stop the spread of germs. But scientists have also suspected silver nanoparticles themselves may be toxic to bacteria, particularly the smallest of them at about 3 nanometers. Not so, according to the Rice team that reported its results this month in the American Chemical Society journal Nano Letters.

In fact, when the possibility of ionization is taken away from silver, the nanoparticles are practically benign in the presence of microbes, said Pedro Alvarez, George R. Brown Professor and chair of Rice's Civil and Environmental Engineering Department. "You would be surprised how often people market things without a full mechanistic understanding of their function," said Alvarez, who studies the fate of nanoparticles in the environment and their potential toxicity, particularly to humans. "The prefix 'nano' can be a double-edged sword. It can help you sell a product, and in other cases it might elicit concerns about potential unintended consequences."

He said the straightforward answer to the decade-old question is that the insoluble silver nanoparticles do not kill cells by direct contact. But soluble ions, when activated via oxidation in the vicinity of bacteria, do the job nicely.

To figure that out, the researchers had to strip the particles of their powers. "Our original expectation was that the smaller a particle is, the greater the toxicity," said Zongming Xiu, a Rice postdoctoral researcher and lead author of the paper. Xiu set out to test nanoparticles, both commercially available and custom-synthesized from 3 to 11 nanometers, to see whether there was a correlation between size and toxicity. "We could not get consistent results," he said. "It was very frustrating and really weird."

Xiu decided to test nanoparticle toxicity in an anaerobic environment -- that is, sealed inside a chamber with no exposure to oxygen -- to control the silver ions' release. He found that the filtered particles were a lot less toxic to microbes than silver ions. Working with the lab of Rice chemist Vicki Colvin, the team then synthesized silver nanoparticles inside the anaerobic chamber to eliminate any chance of oxidation. "We found the particles, even up to a concentration of 195 parts per million, were still not toxic to bacteria," Xiu said. "But for the ionic silver, a concentration of about 15 parts per billion would kill all the bacteria present. That told us the particle is 7,665 times less toxic than the silver ions, indicating a negligible toxicity."

"The point of that experiment," Alvarez said, "was to show that a lot of people were obtaining data that was confounded by a release of ions, which was occurring during exposure they perhaps weren't aware of." Alvarez suggested the team's anaerobic method may be used to test many other kinds of metallic nanoparticles for toxicity and could help fine-tune the antibacterial qualities of silver particles. In their tests, the Rice researchers also found evidence of hormesis; E. coli became stimulated by silver ions when they encountered doses too small to kill them.

"Ultimately, we want to control the rate of (ion) release to obtain the desired concentrations that just do the job," Alvarez said. "You don't want to overshoot and overload the environment with toxic ions while depleting silver, which is a noble metal, a valuable resource -- and a somewhat expensive disinfectant. But you don't want to undershoot, either." He said the finding should shift the debate over the size, shape and coating of silver nanoparticles. "Of course they matter," Alvarez said, "but only indirectly, as far as these variables affect the dissolution rate of the ions. The key determinant of toxicity is the silver ions. So the focus should be on mass-transfer processes and controlled-release mechanisms."

"These findings suggest that the antibacterial application of silver nanoparticles could be enhanced and environmental impacts could be mitigated by modulating the ion release rate, for example, through responsive polymer coatings," Xiu said. Co-authors of the paper are postdoctoral researcher Qingbo Zhang and graduate student Hema Puppala, both in the lab of Colvin, Rice's Kenneth S. Pitzer-Schlumberger Professor of Chemistry, a professor of chemical and biomolecular engineering and vice provost for research.

The work was supported by a joint U.S.-U.K. research program administered by the Environmental Protection Agency and the U.K.'s Natural Environment Research CouncilStory Source:The above story is reprinted from materials provided by Rice University. The original article was written by Mike Williams.Note: Materials may be edited for content and length. For further information, please contact the source cited above.Journal Reference:

1. Zong-ming Xiu, Qing-bo Zhang, Hema L. Puppala, Vicki L. Colvin, Pedro J. J. Alvarez. Negligible Particle-Specific Antibacterial Activity of Silver Nanoparticles. Nano Letters, 2012; : 120709145707008 DOI: 10.1021/nl301934w

http://www.sciencedaily.com/releases/2012/07/120711123016.htm

Silver ions delivered by nanoparticles to bacteria promote lysis, the process by which cells break down and ultimately die, which makes silver nanoparticles a superior and widely used antibacterial agent. New research by Rice University found that silver ions, not the particles themselves, are toxic to bacteria. They also found that ligands in the vicinity of a bacteria can bind silver ions and prevent them from reaching their target. (Credit: Zongming Xiu/Rice University)

Animals that Harnessed

Nanotechnology before Humans

http://discovermagazine.com/photos/07-animals-harnessed-nanotechnologyMara Grunbaum; published April 3, 2012

Photo Credit: Thomas Shahan, Flickr / S. Foletti

INVISIBLE EYESThe animal kingdom boasts many an impressive form, from arching giraffe necks to spoon-shaped bird beaks to gigantic beetle claws. But evolution has worked on much smaller scales too, producing finely honed nanostructures--parts less than a millionth of a meter across, or smaller than 1/20th of the width of a human hair--that help animals climb, slither, camouflage, flirt, and thrive.

Consider an insect's compound eye, which has anywhere from 50 to 10,000 individual facets, each with its own set of optical machinery. Zoom in on the seemingly smooth curves of those facets and, in many insects--like the robber fly seen here--you'll find they're studded with an array of nanoscale protuberances called "corneal nipples." The tiny bumps, which range in diameter from 50 to 300 nanometers, help the insects camouflage: by breaking up the cornea's even surface, they cut down the glare that reflects off the eye, which could potentially alert a predator to the bug's presence. The nanoscale nipple pattern on moth eyes has inspired new anti-reflective coatings for solar cells.

In 2010, German scientists discovered another useful function of corneal nipples: they help keep pollen grains, dust particles, and other microscopic crud out of the insects' eyes. The bumpy texture means less contact area for a small particle to cling onto, so even when the rest of the bugs' bodies get grimy, the eyes stay clean.

Credit: MattiPaavola, Wikimedia Commons/Credit: Marian Plotkin

SOLAR-POWERED BUGSMost wasps are most active in the morning and slow down considerably at midday, when the sun's heat is most oppressive. Not so oriental hornets, who build nests underground: their workers do more digging the more they're bombarded with sunlight. That's probably because, as researchers at Tel Aviv University revealed, nanostructures in the insect's exoskeleton form a kind of solar cell, harvesting light energy that could power the hornet's work.

In the brown section of the hornet's abdomen, the layers of cuticle that make up the exoskeleton are embossed with grooves about 160 nanometers high. The grooves are arranged into a sort of grating, which helps trap the light that hits the hornet and bounce it around within the cuticle. The yellow section, which has small, interlocking protrusions about 50 nanometers high, also absorbs light--and the researchers showed that xanthoperin, the pigment that gives it its yellow color, can be used to convert light into electricity. It's likely doing just that inside the insect, which would explain why they're busiest when it's sunniest--and why, as a previous study found, anesthetized Oriental hornets wake up faster when they're pounded with UV light.

Credit: Nick Seeger, Flickr

SLIPPERY SKINSnakes like the ball python seem to slither effortlessly, but their movement is a actually a complex interaction of muscle movement and small-scale physics. On a nanoscale level, the scales on a snake's belly are covered in minuscule hairs, called microfibrils, which are less than 400 nanometers wide. They all point in the same direction--toward the tail end of the snake--and their ends are raised about 200 nanometers off the skin, allowing for a smooth glide forward but stopping any backward motion, like a row of one-way traffic spikes. The extra friction in only one direction helps prevent sideways slipping, even if the snake is inclined on a plane.

Credit: Credit: Liliana D'Alba/Peter Gaylard, Flickr

FLASHY FEATHERSButterflies aren't the only animals who harness nanotech for cosmetic purposes; so do birds, whose dazzling array of colors comes from a combination of pigment-producing cells and nanoscale design.

In Australia and New Zealand, the little penguin Eudyptula minor sports a tuxedo of dark blue feathers instead of the more traditional (and formal) black. Last year, scientists at the University of Akron in Ohio used X-ray imaging and other techniques to discover that the penguins produce the blue color in an entirely new way: with bundles of parallel nanofibers, like handfuls of uncooked spaghetti, that scatter light so as to produce the rich blue. The 180-nanometer-wide fibers are made of beta-keratin, a protein similar to the one in human hair. Similar fibers had previously been found in some birds' blue skin, where they are made of collagen rather than keratin, but never before in blue feathers.

Credit: David Goehring, Flickr

DAZZLING WINGSMany of the shimmering colors in a butterfly's wings are produced not with pigments, like the melanin that tints our skin, but with nanostructures (pdf). The scales on their wings are patterned with nanoscale channels, ridges, and cavities made of a protein called chitin. Unlike pigments, which create color by absorbing some wavelengths of light and reflecting the rest, the nanostructures are shaped so that they physically bend and scatter light in different directions, sending particular colors back to our eyes. That scattering can also make the wing scales iridescent--meaning the color changes with the angle you see it from.

When heat, in the form of invisible infrared radiation, hits the chitin nanostructures, they expand, changing their shape and therefore the colors they display. Scientists at GE are working to harness this property to make hypersensitive thermal imaging sensors, useful for night vision. By coating the wings of a Blue Morpho butterfly with carbon nanotubes that magnify the effect, researchers there made an insect into a sensor that changes color when its temperature changes a mere 1/25th of a degree.

Credit: Nick Hobgood, Flickr/Credit: Travis Hagey

NANOTECH TOESThe tokay gecko uses nanotechnology to stick itself to trees, walls, windows, and even ceilings. The gecko's feet are covered in microscopic hairs, called setae, which branch into thousands of smaller hairs with paddle-shaped ends. Those branches, or spatulae, are a mere 200 nanometers wide at the tip.

The extra surface area of the spatulae maximizes the effect of van der Waals forces, the weak electrical pull between every molecule in the gecko and every molecule in whatever it's sticking to. The combined force is so strong that a gecko can hang its whole weight from a single toe, even on a sheer piece of glass. Engineers have used carbon nanotubes mimicking gecko setae to create super-sticky tapes, glues, and even a wall-climbing gecko robot.

Dental Hygienist

Wikimedia Commons

SUPER-TOUGH SILKSpider silks are some of the toughest materials known to man--pound for pound, they're stronger than steel, and their webs can stand up to gusts of wind and catch hurtling insects without falling to pieces.

The silks get their strength from thin crystal proteins only nanometers wide, which are stacked together like pancakes. On the atomic level, the layers are joined together by hydrogen bonds. Those bonds actually aren't particularly strong, but that turns out to be an advantage, because they can easily pull apart and reform, allowing the silk to stretch and flex under pressure instead of snapping like a twig.

In February, Italian scientists found what they think is the stretchiest silk yet in the egg sac of the European cave spider, Meta menardi--which also just so happens to be the European Society of Arachnology's 2012 Spider of the Year. Call that one a win for animal nanotechnology.

Nature of the WorkDental hygienists remove soft and hard deposits from teeth, teach patients how to practice good oral hygiene, and provide other preventive dental care. They examine patients' teeth and gums, recording the presence of diseases or abnormalities.

Dental hygienists use an assortment of tools to complete their tasks. Hand and rotary instruments, as well as ultrasonic devices, are used to clean and polish teeth, including removing tartar, stains, and plaque. Hygienists use x-ray machines to take dental pictures, and sometimes develop the film. They might use models of teeth to explain oral hygiene, perform root planning as a periodontal therapy, or apply cavity-preventive agents, such as fluorides and pit and fissure sealants.

Other tasks hygienists might perform vary by state. In some states, hygienists are allowed to administer anesthetics, while in others they administer local anesthetics using syringes. Some states also allow hygienists to place and carve filling materials, temporary fillings, and periodontal dressings; remove sutures; and smooth and polish metal restorations.

Dental hygienists also help patients develop and maintain good oral health. For example, they might explain the relationship between diet and oral health or inform patients about how to select toothbrushes and show them how to brush and floss their teeth.

Hygienists sometimes make a diagnosis, and other times, prepare clinical and laboratory diagnostic tests for the dentist to interpret. Hygienists sometimes work chair-side with the dentist during treatment.

Work EnvironmentDental hygienists work in clean, well-lit offices. Important health safeguards include strict adherence to proper radiological procedures and the use of appropriate protective devices when administering anesthetic gas. Dental hygienists also wear safety glasses, surgical masks, and gloves to protect themselves and patients from infectious diseases. Dental hygienists also should be careful to avoid possible shoulder and neck injury from sitting for long periods of time while working with patients.

Flexible scheduling is a distinctive feature of this job. Full-time, part-time, evening, and weekend schedules are common. Dentists frequently hire hygienists to work only two or three days a week, so hygienists might hold jobs in more than one dental office. In 2008, about half of all dental hygienists worked part-time—less than 35 hours a week.

Training, Other QualificationsA degree from an accredited dental hygiene school and a state license are required for this job.

Education and TrainingA high school diploma and college entrance test scores are usually required for admission to a dental hygiene program. High school students interested in becoming dental hygienists should take courses in biology, chemistry, and mathematics. Some dental hygiene programs also require applicants to have completed at least one year of college. Specific entrance requirements typically vary from one school to another.

In 2008, there were 301 dental hygiene programs accredited by the Commission on Dental Accreditation. Most dental hygiene programs grant an associate degree, although some also offer a certificate, a bachelor's degree, or a master's degree. A minimum of an associate's degree or certificate in dental hygiene is generally required for practice in a private dental office. A bachelor's or master's degree usually is required for research, teaching, or clinical practice in public or school health programs.

Schools offer laboratory, clinical, and classroom instruction in subjects such as anatomy, physiology, chemistry, microbiology, pharmacology, nutrition, radiography, histology (the study of tissue structure), periodontology (the study of gum diseases), pathology, dental materials, clinical dental hygiene, and social and behavioral sciences.

Other QualificationsDental hygienists should work well with others because they work closely with dentists and dental assistants, as well as deal directly with patients. Hygienists also need good manual dexterity, because they use dental instruments within patients’ mouths, with little room for error.

On the Job• Clean calcareous deposits, accretions, and stains from teeth and beneath margins of gums,

using dental instruments.• Record and review patient medical histories.• Examine gums, using probes, to locate periodontal recessed gums and signs of gum disease.• Provide clinical services and health education to improve and maintain the oral health of

patients and the general public.• Feel and visually examine gums for sores and signs of disease.• Expose and develop x-ray film.• Chart conditions of decay and disease for diagnosis and treatment by dentist.• Maintain dental equipment and sharpen and sterilize dental instruments.• Apply fluorides and other cavity preventing agents to arrest dental decay.• Feel lymph nodes under patient's chin to detect swelling or tenderness that could indicate

presence of oral cancer.• Maintain patient recall system.• Remove excess cement from coronal surfaces of teeth.• Administer local anesthetic agents.• Conduct dental health clinics for community groups to augment services of dentist.• Remove sutures and dressings.• Make impressions for study casts.• Place and remove rubber dams, matrices, and temporary restorations.Source: BLS

Companies That Hire Dental Hygienists

• Bright Now! Dental • ETS Dental • U.S. Army Ask QuestionsDo you have a specific question about a career in Human Biology & Health that isn't answered

on this page? Post your question on Science Buddies Ask an Expert Forum.

Additional Information• American Dental Hygienists' Association • Commission on Dental Accreditation, American Dental Association Sources• O*Net Online. (2009). National Center for O*Net Development. Retrieved May 1, 2009, from

http://online.onetcenter.org/• Commonwealth of Massachusetts Department of Public Health. (n.d.). So You Want to Be a

Public Health Dental Hygienist? Working In The Schools. Retrieved August 24, 2010, from http://www.youtube.com/watch?v=_H5TMEeOlJo

• National Institutes of Health. (2006, June 12). Meet a real Dental Hygienist, Sherri Gollins. Retrieved May 20, 2010, from http://science.education.nih.gov/lifeworks.nsf/Interviews/Sherri+Gollins#Q1

http://www.sciencebuddies.org/science-fair-projects/science-engineering-careers/HumBio_dentalhygienist_c001.shtml?From=testb