CAN YOU REALLY HOLD ONTO THE ROOF OF A SPEEDING CAR?

Finding: PLAUSIBLEExplanation: Swimmers have pondered the ills of poor water quality and its role in speed-reduction for years. In 2003, researchers at the University of Minnesota finally put this mystery to the test, finding that swimming in syrup wouldn't really slow a swimmer's progress. But the MythBusters decided to "go for the goo" themselves.Jamie Hyneman and Adam Savage compared the time it took to paddle from one end of the pool to the other, both in water and a syrup-like guar gum mixture. While the tests went swimmingly, the results were surprising. Slogging through a pool of sticky stuff would add only a small amount of time to your personal best. Turns out, the physical energy a swimmer uses actually matters more than the thickness of the "water." This phenomenon, called theoretical square law, means a swimmer's motion is determined more by the speed of arm and leg movements than by the fluid he's moving through.So, even if you're swimming in syrup, you could move your arms faster to make up for the drag. You aren't likely to break any speed records simply because you'll tire faster, but you can still get the job done.As seen in "MythBusters: Swimming in Syrup."

IS IT POSSIBLE TO SWIM JUST AS FAST IN SYRUP AS YOU DO IN WATER?

Finding: BUSTEDExplanation: When you see a movie scene where a guy is clinging to the roof of a moving car, there's a good chance the stuntman in question is safely harnessed to the vehicle. Otherwise, it would be pretty much impossible to hang on for the ride.Unless a car's windows are down, there's little to hold on to when you're on the roof. Even at speeds under 45 miles per hour, the MythBusters demonstrated that a person can't grip tightly enough to stay atop a car while it's moving. Any turning or stopping only makes matters worse, since Newton's laws of motion won't work in your favor. For example, if the car turns, an invisible nemesis called centrifugal force — a kind of inertia that keeps you flying away from the center of rotation — will literally shove you off the roof.And when the driver slams on the brakes, your forward-moving body will keep right on sailing into the air. With the windows lowered — or if you hop on the car's slightly easier-to-grip hood — there's a better chance that you could hang on for dear life, but the odds still aren't in your favor.Sorry, did we just ruin that summer blockbuster for you?As seen in "MythBusters: Prison Escape."

Tackling Obesity by Manipulating Gut Floraby Will Parker

(27 August 2012) Antibiotics could one day be the standard treatment for regulating weight, suggests a new study in Nature Immunology that examines the interactions between diet, the bacteria in our gut, and our immune systems.

The 500 different types of bacteria present in our gut provide the enzymes necessary for the uptake of nutrients, synthesize certain vitamins and boost absorption of energy from food. Last century, farmers learned that by tweaking the microbial mix in their livestock with low-dose oral antibiotics, they could accelerate weight gain.

In the new study, researchers at the University of Chicago found they were able to manipulate some of the mechanisms that regulate weight gain. They focused on the relationship between the immune system, gut bacteria, digestion and obesity. Their findings show how weight gain requires not just caloric overload but also a delicate, adjustable - and transmissible - interplay between intestinal microbes and the immune response.

"Diet-induced obesity depends not just on calories ingested but also on the host's microbiome," said the study's senior author Yang-Xin Fu, professor of pathology at the University of Chicago Medical Center. "For most people, host digestion is not completely efficient, but changes in the gut flora can raise or lower digestive efficiency."

In one experiment, the researchers compared normal mice with mice that have a genetic defect that renders them unable to produce lymphotoxin, a molecule that helps to regulate interactions between the immune system and bacteria in the bowel. On a standard diet, both groups of mice maintained a steady weight. But after nine weeks on a high-fat diet, the normal mice increased their weight by one-third, most of it fat. Mice lacking lymphotoxin ate just as much, but did not gain weight.

According to Fu, the high-fat diet triggered changes in gut microbes for both groups. The normal mice had a substantial increase in a class of bacteria (Erysopelotrichi) that has previously been associated with obesity.

The role of gut microbes was confirmed when the researchers transplanted bowel contents from the study mice to normal mice raised in a germ-free environment - and thus lacking their own microbiome. Mice who received commensal bacteria from donors that made lymphotoxin gained weight rapidly. Those that got the bacteria from mice lacking lymphotoxin gained much less weight for about three weeks, until their own intact immune system began to normalize their bacterial mix.

When housed together, the mice performed their own microbial transplants (mice are coprophagic, eating each other's droppings). In this way, the authors note, mice housed together "colonize one another with their own microbial communities." After weeks together, even mice with the immune defect began to gain weight.

Fu says moving from normal chow to the high-fat diet initiated a series of related changes. First, it altered the balance of microbes in the digestive system. These changes in the microbiome altered the immune response, which then introduced further changes to the intestinal microbial community. These changes "provide inertia for the obese state," the authors claim, facilitating more efficient use of scarce food resources.

"Our results suggest that it may be possible to learn how to regulate these microbes in ways that could help prevent diseases associated with obesity," said co-researcher Vaibhav Upadhyay. "We now think we could inhibit the negative side effects of obesity by regulating the microbiota and perhaps manipulating the immune response."

Or, 20 years from now, "when there are 10 billion people living on earth and competing for food, we may want to tilt digestive efficiency in the other direction," Fu added.

http://www.sciencedaily.com/releases/2012/08/120824103020.htm

Helicobacter pylori bacteria in stomachCredit: DAVID MCCARTHY/SCIENCE PHOTO LIBRARYCaption: Helicobacter pylori bacteria. Coloured scanning electron micrograph (SEM) of Helicobacter pylori bacteria (pink), a cause of gastritis (stomach lining inflammation). These Gram- negative, rod- shaped, bacteria are commonly found in the mucosal lining of the stomach in middle-aged people. Their presence is also associated with the formation of ulcers in the duodenum (part of the small intestine). Magnification: x3100 at 6x7cm size.

http://www.sciencephoto.com/media/11851/enlarge

Most Mutations Come from Dad: New Insights Into Age, Height and Sex Reshape Views of Human Evolution(Aug. 23, 2012) — Humans inherit more than three times as many mutations from their fathers as from their mothers, and mutation rates increase with the father's age but not the mother's, researchers have found in the largest study of human genetic mutations to date.The study, based on the DNA of around 85,000 Icelanders, also calculates the rate of human mutation at high resolution, providing estimates of when human ancestors diverged from nonhuman primates. It is one of two papers published this week by the journal Nature Genetics as well as one published at Nature that shed dramatic new light on human evolution."Most mutations come from dad," said David Reich, professor of genetics at Harvard Medical School and a co-leader of the study. In addition to finding 3.3 paternal germline mutations for each maternal mutation, the study also found that the mutation rate in fathers doubles from age 20 to 58 but that there is no association with age in mothers -- a finding that may shed light on conditions, such as autism, that correlate with the father's age.The study's first author is James Sun, a graduate student in Reich's lab who worked with researchers from deCODE Genetics, a biopharma company based in Reykjavik, Iceland, to analyze about 2,500 short sequences of DNA taken from 85,289 Icelanders in 24,832 father-mother-child trios. The sequences, called microsatellites, vary in the number of times that they repeat, and are known to mutate at a higher rate than average places in the genome.Reich's team identified 2,058 mutational changes, yielding a rate of mutation that suggests human and chimpanzee ancestral populations diverged between 3.7 million and 6.6 million years ago.A second team, also based at deCODE Genetics (but not involving HMS researchers), published a paper this week in Nature on a large-scale direct estimate of the rate of single nucleotide substitutions in human genomes (a different type of mutation process), and came to largely consistent findings.The finding complicates theories drawn from the fossil evidence. The upper bound, 6.6 million years, is less than the published date of Sahelanthropus tchadensis, a fossil that has been interpreted to be a human ancestor since the separation of chimpanzees, but is dated to around 7 million years old. The new study suggests that this fossil may be incorrectly interpreted.Great Heights - A second study led by HMS researchers, also published in Nature Genetics this

week, adds to the picture of human evolution, describing a newly observable form of recent genetic adaptation.The team led by Joel Hirschhorn, Concordia Professor of Pediatrics and professor of genetics at Boston Children's Hospital and HMS, first asked why closely-related populations can have noticeably different average heights. David Reich also contributed to this study.They examined genome-wide association data and found that average differences in height across Europe are partly due to genetic factors. They then showed that these genetic differences are the result of an evolutionary process that acts on variation in many genes at once. This type of evolution had been proposed to exist but had not previously been detected in humans.Although recent human evolution is difficult to observe directly, some of its impact can be inferred by studying the human genome. In recent years, genetic studies have uncovered many examples where recent evolution has left a distinctive signature on the human genome. The clearest "footprints" of evolution have been seen in regions of DNA surrounding mutations that occurred fairly recently (typically in the last several thousand years) and confer an advantageous trait, such as resistance to malaria. Hirschhorn's team observed, for the first time in humans, a different signature of recent evolution: widespread small but consistent changes at many different places in the genome, all affecting the same trait, adult height."This paper offers the first proof and clear example of a new kind of human evolution for a specific trait," said Hirschhorn, who is also a senior associate member of the Broad Institute. "We provide a demonstration of how humans have been able to adapt rapidly without needing to wait for new mutations to happen, by drawing instead on the existing genetic diversity within the human population."Average heights can differ between populations, even populations that are genetically very similar, which suggests that human height might have been evolving differently across these populations. Hirschhorn's team studied variants in the genome that are known to have small but consistent effects on height: people inheriting the "tall" version of these variants are known to be slightly taller on average than people inheriting the "short" versions of the same variants.The researchers discovered that, in northern Europe, the "tall" versions of these variants are consistently a little more common than they are in southern Europe. The combined effects of the "tall" versions being more common can partly explain why northern Europeans are on average taller than southern Europeans. The researchers then showed that these slight differences have arisen as a result of evolution acting at many variants, and acting differently in northern than in southern Europe."This paper explains -- at least in part -- why some European populations, such as people from Sweden, are taller on average than others, such as people from Italy," Hirschhorn said.The researchers were only able to detect this signature of evolution by using the results of recent genome-wide association studies by the GIANT consortium, which identified hundreds of different genetic variants that influence height.

Story Source: The above story is reprinted from materials provided by Harvard Medical School. The original article was written by R. Alan Leo.Note: Materials may be edited for content and length. For further information, please contact the source cited above.

Journal References:1. James X Sun, Agnar Helgason, Gisli Masson, Sigríður Sunna Ebenesersdóttir, Heng Li,

Swapan Mallick, Sante Gnerre, Nick Patterson, Augustine Kong, David Reich & Kari Stefansson. A direct characterization of human mutation based on microsatellites. Nature, August 23, 2012 DOI: 10.1038/ng.2398

Michael C Turchin, Charleston WK Chiang, Cameron D Palmer, Sriram Sankararaman, David Reich, Joel N Hirschhorn. Evidence of widespread selection on standing variation in Europe at height-associated SNPs. Nature Genetics, 2012; DOI: 10.1038/ng.2368

http://www.sciencedaily.com/releases/2012/08/120824103020.htm

Nerves innervate color-changing structures called iridophores in squid skin. CREDIT: Wardill, Gonzalez-Bellido, Crook & Hanlon, Proceedings of the Royal Society B: Biological Sciences

The Physics of Loudmouths: Why Some Voices CarryBy: Natalie Wolchover, Life's Little Mysteries Staff Writer

(07 August 2012) - You know that guy with the voice heard 'round the world? The one who — no matter how far away he is — sounds as if he is shrieking directly into your ear? He seems to show up at every party, restaurant and (worst of all) office.Voices that "carry" contain a pitch of sound that strongly resonates with both the human vocal tract and the human ear, said acoustics expert John Smith, a biophysicist at the University of New South Wales in New Zealand. This piercing pitch, dubbed the "speaker's formant," has a frequency around 3,000 hertz, or 3,000 beats per second: about the same frequency as that of fingernails scraping a chalkboard.

By comparison, most human speech falls in the gentler 80- to 250-hertz (Hz) range.

How do loudmouthed people generate that much faster and much more earsplitting frequency? Understanding their method requires a short lesson on how speech works.

We generate sound by rapidly vibrating two small flaps of mucous membrane called vocal folds in our voice boxes, Smith said. The back-and-forth motions of these folds interrupt the flow of air from our lungs to create "puffs" of sound. If our vocal folds wiggle back and forth 100 times each second, they produce puffs with a frequency of 100 beats per second (Hz). However, additional motions of the vocal folds, such as collisions with each other, can generate additional frequencies that are multiples of that fundamental frequency: "harmonics" at 200 Hz, 300 Hz, 400 Hz and so on.

All these frequencies travel together through the vocal tract — the tubelike cavity leading from the voice box up through the throat and mouth to the outside world. Depending on its shape, this tract resonates at certain frequencies, meaning it vibrates in time with them. In the same way that an organ pipe increases the amplitude of the sound waves that travel through it, the resonance of the vocal tract amplifies those resonant frequencies, making them louder.

And that's the trick: Whether done subconsciously or on purpose, loud talkers have learned to harness the natural resonances of their vocal tracts to pump up the volume of their voices. First, they manipulate their vocal folds to generate a harmonic frequency up around 3,000 Hz. "This could involve using a stronger flow of air from the lungs and controlling the folds so they undergo a motion that results in a sound that is intrinsically richer in harmonics," Smith told Life's Little Mysteries. Most people mainly produce harmonics at lower frequencies. 

Second, they alter the shape of their vocal tract, often narrowing or restricting the tract just above the vocal folds, so that it will resonate at that high frequency, making the high frequency louder. "This increase in sound level occurs in a frequency range where the ear is more sensitive and where background noise is usually reduced," Smith said. "Coupled with any increased harmonic content from the vocal folds, it can produce a large increase in subjective loudness."

Recent and ongoing research by Smith and his colleagues shows that singers make similar adjustments to their vocal tracts in order to project their voices. The scientists have managed to characterize how this is done at different pitches. In a report published in January in the Journal of the Acoustic Society of America, they showed that even trumpet players seem to control their own vocal resonances in order to play very high notes.

The difference is, singers and musicians are paid to project their sounds. Loudmouths do it voluntarily.

http://www.lifeslittlemysteries.com/2752-loudmouth-voices-carry.html

http://www.randallmorton.com/Voice.htm

Secret to Squid's Iridescent Rainbow Skin DiscoveredStephanie Pappas, LiveScience Senior Writer

(14 August 2012) - For squid looking to sparkle, extra bling is only seconds away, thanks to a nerve network in the skin that allows these cephalopods to alter their iridescence — the first invertebrate creatures found to have this ability.A new study finds that electrical stimulation of the nerves in squid skin changes the color and reflectance of tiny platelike structures called iridophores in the skin, allowing changes in hue from red all the way through the color spectrum to blue.

Oddly enough, despite their bright displays, these squid see only in black-and-white, deepening the mystery of why and how they pick a color from their array.

"The cool thing about it is that these animals are colorblind and yet they are producing a color signal," said study researcher Paloma Gonzalez Bellido of the Marine Biological Laboratory (MBL) at Woods Hole, Mass. "It's puzzling to us — even if it isn't for [squid to see], if it is for camouflage, how do you know you're doing this right? You can't see color."

Creating iridescenceSquid, octopus and other cephalopods have amazing color-changing abilities thanks to specialized structures in their skin called chromatophores. But most squid species also have another set of specialized structures called iridophores, said study researcher Trevor Wardill, a research associate at MBL.

Unlike most colors we see, which are caused by pigments absorbing and reflecting certain wavelengths of light, iridescence is caused by structures interfering with the reflectance of light, causing the wavelengths to interact with one another and creating intense, almost metallic hues. Iridophores are made of complex stacked plates that cause this interference, Wardill told LiveScience.

What wasn't clear is how the iridophores worked. By definition, iridescent color appears slightly different when viewed from different angles, Wardill said, so measuring iridescence changes is tricky.

To figure out the iridophores' secrets, the researchers carefully dissected the skin of dead longfin inshore squid (Doryteuthis pealeii). They traced the nerves of the skin and stimulated them electrically, finding that they could instigate progressive changes in skin color from the at-rest reddish state all the way through the color spectrum to blue.

Unlike the very fast changes seen in chromatophores, the alteration in iridophores moves more slowly, Wardill said, cycling through the rainbow from red to orange to yellow to green to blue over a period of about 15 seconds.

Color-changing mysteryThe neural control for the color changes isn't a local reflex, Gonzalez Bellido said; it comes from the central nervous system. The next mystery to solve is how precisely the squid can pick and hold any given color, Wardill said. In the end, the researchers hope to understand how these cephalopods decide without the benefit of color vision what hues they need to display.

"The animals are actually developing color on the skin and they're doing it without pigments, and they potentially have the chance to be picking a certain color," Wardill said. "That would be very exciting, because there are not many examples from any animals that could pick a color and put it on so quickly."

The researchers report their work today (Aug. 14) in the journal Biological Sciences.Follow Stephanie Pappas on Twitter @sipappas or LiveScience @livescience. We're also on Facebook & Google+. 

http://www.livescience.com/22365-squid-iridescent-rainbow-skin-changes.html

http://evolution.berkeley.edu/evosite/evo101/IIIC3Causes.shtml

Dietitian/NutritionistDietitians and nutritionists are experts in food and nutrition. They advise people on what to eat in order to lead a healthy lifestyle or achieve a specific health-related goal.

DutiesDietitians and nutritionists typically do the following:

Explain nutrition issues Assess patients’ and clients’ health needs and diet Develop meal plans, taking both cost and clients’ preferences into account Evaluate the effects of meal plans and change the plans as needed Promote better nutrition by giving talks to groups about diet, nutrition, and the

relationship between good eating habits and preventing or managing specific diseases Keep up with the latest nutritional science research

Some dietitians and nutritionists provide customized information for specific individuals. For example, a dietitian or nutritionist might teach a patient with high blood pressure how to use less salt when preparing meals. Others work with groups of people who have similar needs. A dietitian or nutritionist might, for example, plan a diet with reduced fat and sugar to help overweight people lose weight.

Although all dietitians and nutritionists do similar tasks, there are several specialties within the occupations. The following are examples of types of dietitians and nutritionists:

Clinical dietitians provide medical nutrition therapy. They work in hospitals, long-term care facilities, and other institutions. They create both individualized and group nutritional programs based on the health needs of patients or residents. Clinical dietitians may further specialize, such as working only with patients with kidney diseases. They may work with other healthcare professionals.

Management dietitians plan meal programs. They work in food service settings such as cafeterias, hospitals, and food corporations. They may be responsible for buying food and for carrying out other business-related tasks. Management dietitians may oversee kitchen staff or other dietitians.

Community dietitians educate the public on topics related to food and nutrition. They often work with specific groups of people, such as pregnant women. They work in public health clinics, government and non-profit agencies, health maintenance organizations (HMOs), and other settings.

Work EnvironmentDietitians and nutritionists held about 64,400 jobs in 2010. 

Dietitians and nutritionists work in hospitals, cafeterias, nursing homes, and schools. Some dietitians and nutritionists are self-employed and maintain their own practice. They work as consultants, providing advice to individual clients, or they work for healthcare establishments on a contract basis.    

Work Schedules - Most dietitians and nutritionists work full time, although about 20 percent work part time. Self-employed, consultant dietitians have more flexibility in setting their schedules.

How to Become a Dietitian or NutritionistMost dietitians and nutritionists have earned a bachelor’s degree and receive supervised training through an internship or as a part of their coursework. Also, many states require dietitians and nutritionists to be licensed.Education - Most dietitians and nutritionists have earned a bachelor’s degree in dietetics, foods and nutrition, food service systems management, or a related area. Programs include courses in nutrition, physiology, chemistry, and biology. Training - Dietitians and nutritionists typically participate in several hundred hours of supervised training, usually in the form of an internship following graduation from college. However, some programs in dietetics include this training as part of the coursework.Many dietitians and nutritionists have advanced degrees. Licenses and Certification - Most states require licensure of dietitians and nutritionists. Other states require only state registration or certification, and a few have no state regulations.

Most states have enacted state licensure or certification for dietitians or nutritionists or both. The requirements for state licensure and state certification include having a bachelor’s degree in food and nutrition or a related area, supervised practice, and passing an exam.

One way to become licensed is to earn the Registered Dietitian (RD) credential. While the RD is not always required, the qualifications necessary to become an RD are parallel to the qualifications necessary to become a licensed dietitian in all states that require a license. Many employers prefer or require the RD, which is administered by the Commission on Dietetic Registration, the credentialing agency for the Academy of Nutrition and Dietetics.

The requirements for the RD credential are similar, but not identical to the licensing requirements in many states. The RD requires dietitians to complete education and supervised practice programs. These programs are accredited by the Accreditation Council for Education in Nutrition and Dietetics (ACEND). In order to maintain the RD credential, Registered Dietitians must complete continuing professional education courses. 

Important QualitiesAnalytical skills. Dietitians must keep up to date with the latest nutrition research. They should be able to interpret scientific studies and translate nutrition science into practical eating advice.

Organizational skills. Because there are many aspects to the work of dietitians and nutritionists, they should have the ability to stay organized. Management dietitians, for example, must consider both the nutritional needs of their customers and the costs of meals.

People skills. Dietitians and nutritionists must listen carefully to understand clients’ goals and concerns. They also have to be emphatic to help clients confront and overcome dietary struggles.

Speaking skills. Dietitians and nutritionists must explain complicated topics in a way that people with less technical knowledge understand. For example, a clinical dietitian must be able to clearly tell clients about what to eat and why eating the recommended foods is important.

PayThe median annual wage of dietitians and nutritionists was $53,250 in May 2010. The median annual wage is the wage at which half the workers in an occupation earned more than that amount and half earned less. The lowest 10 percent earned less than $33,330, and the top 10 percent earned more than $75,480.

Most dietitians and nutritionists work full time, although about 20 percent work part time. Self-employed, consultant dietitians have more flexibility in setting their schedules.

Job OutlookEmployment of dietitians and nutritionists is expected to increase 20 percent from 2010 to 2020, faster than average for all occupations.

In recent years, there has been increased interest in the role of food in promoting health and wellness, particularly as a part of preventative healthcare in medical settings. The importance of diet in preventing and treating illnesses such as diabetes and heart disease is now well known. More dietitians and nutritionists will be needed to provide care for people with these conditions.  

An aging population also will increase the need for dietitians and nutritionists in nursing homes.

Contacts for More InformationFor a list of academic programs, scholarships, and other information about dietitians, visit Academy of Nutrition and Dietetics

For information on the Registered Dietitian (RD) exam and other specialty credentials, visitCommission on Dietetic Registration

http://www.bls.gov/ooh/Healthcare/Dietitians-and-nutritionists.htm#tab-1

Photo Gallery: Animal Record

Breakershttp://animals.nationalgeographic.com/animals/photos/animal-records-gallery/

African ElephantPhotograph by Beverly Joubert

For thousands of years, humans have utilized the brute strength of African and Asian elephants for everything from war to transportation. An elephant's trunk alone contains around 100,000 muscles and can lift up to 600 pounds (270 kilograms).

Rhinoceros BeetlePhotograph by Jupiterimages

Compared to an elephant, the rhinoceros beetle looks minuscule. But ounce for ounce, this insect is considered the world's strongest creature. Rhinoceros beetles, which get their name from the hornlike structure on a male's head, are capable of carrying up to 850 times their own body weight. A human with this relative strength would be able to lift some 65 tons (59 metric tons).

FroghopperPhotograph by Jupiterimages

The froghopper, or spittle bug, leaps into the record books as the insect world's greatest jumper. This tiny insect reaches a mere 0.2 inches (6 millimeters) in length but can catapult itself up to 28 inches (70 centimeters) into the air. A human with this ability would be able to clear a 690-foot-tall (210-meter-tall) skyscraper.

ImpalaPhotograph by Chris Johns

The impala, an African antelope with long, slender legs and muscular thighs, also gets high marks for its leaping abilities. When frightened, an impala will spring into action, bounding up to 33 feet (10 meters) and soaring some 10 feet (3 meters) in the air. This skill is apparently more than just defensive. Impalas have been observed jumping around just to amuse themselves.

Bar-Tailed GodwitPhotograph courtesy USFWS

In 2007, a bar-tailed godwit made the longest nonstop bird migration ever recorded. In nine days, it flew 7,145 miles (11,500 kilometers) from its breeding ground in Alaska to New Zealand without stopping for food or drink. By the end of the epic journey, the bird had lost more than 50 percent of its body weight.

Sooty ShearwaterPhotograph by Terry Whittaker / Alamy

The annual journey of the sooty shearwater bird rivals that of the bar-tailed godwit. These marathon migrators traverse nearly 40,000 miles (64,000 kilometers) each year, from New Zealand to the Northern Hemisphere, in search of food.

Great White SharkPhotograph by Mike Parry/Minden Pictures

In 2005, a great white shark entered the record books by completing the longest shark migration ever recorded. Named Nicole by researchers, the shark made a 12,400-mile (20,000-kilometer) marathon circuit from Africa to Australia. The journey, which lasted nine months, also included the fastest return migration of any known marine animal.

Tracking systems showed that Nicole spent a lot of the time near the surface, leading some scientists to believe that sharks use celestial cues to navigate.

SailfishPhotograph by John Lewis, National Geographic My Shot

Officially the world's fastest fish, sailfish can reach speeds of 68 miles an hour (109 kilometers an hour) in short bursts. They often hunt in groups and use their quickness and impressive dorsal fins to herd schools of sardines or anchovies.

CheetahPhotograph by Chris Johns

The cheetah, holder of the animal kingdom's land speed record, can run at more than 60 miles an hour (96 kilometers an hour) and can reach its top speed in just three seconds. These champion sprinters rely on long, muscular legs to propel their lithe bodies. But cheetahs expend a tremendous amount of energy during a chase and can only run all out for about 900 feet (274 meters).

T. RexIllustration by Michael Skrepnick

Scientists have long debated the speed and agility of this prehistoric giant. While some propose that T rex. was capable of nothing more than a leisurely jog, other investigations have shown that the six-ton (5.4-metric-ton) predator could possibly have outrun an Olympic sprinter, reaching a top speed of 18 miles an hour (29 kilometers an hour).

Peregrine FalconPhotograph by Tim Fitzharris / Minden Pictures

The peregrine falcon holds the title of the animal kingdom's fastest flier. Using a dive-bomb hunting technique called a stoop, this raptor attacks prey—usually a pigeon or dove—at speeds of up to 200 miles an hour (322 kilometers an hour).

It seizes its victim in midair with its sharp talons, then takes it to the ground to eat.