Tree squirrels are the members of the squirrel family (Sciuridae) commonly just referred to as "squirrels". They include more than 100 arboreal species native to all continents except Antarctica and Oceania .
96-441: They do not form a single natural, or monophyletic , group; they are variously related to others in the squirrel family, including ground squirrels , flying squirrels , marmots , and chipmunks . The defining characteristic used to determine which species of Sciuridae are tree squirrels is dependent on their habitat rather than their physiology . Tree squirrels live mostly among trees, as opposed to those that live in burrows in
192-618: A health risk to humans. In 2007 in the northern New Jersey community of Ringwood , the New Jersey Department of Health and Senior Services issued a warning to anyone who eats squirrel (especially children and those who are pregnant) to limit their consumption after a lead -contaminated squirrel was found near the Ringwood Mines Landfill . Toxic waste had been illegally dumped at this location for many years, before authorities cracked down on this practice in
288-439: A 3 GHz sound wave could produce resolution comparable to an optical image, was recognized by Sergei Sokolov in 1939. Such frequencies were not possible at the time, and what technology did exist produced relatively low-contrast images with poor sensitivity. Ultrasonic imaging uses frequencies of 2 megahertz and higher; the shorter wavelength allows resolution of small internal details in structures and tissues. The power density
384-606: A World Championship Squirrel cook-off each year in Bentonville, Arkansas . For most of the history of the United Kingdom , squirrel has been a meat not commonly eaten, and even scorned by many. In the early 21st century however, the wild squirrel has become a more popular meat to cook with, showing up in restaurants and shops more often in Britain as a fashionable alternative meat. Specifically, Britons are cooking with
480-412: A bat, some insects will make evasive manoeuvres to escape being caught. Ultrasonic frequencies trigger a reflex action in the noctuid moth that causes it to drop slightly in its flight to evade attack. Tiger moths also emit clicks which may disturb bats' echolocation, and in other cases may advertise the fact that they are poisonous by emitting sound. Dogs and cats' hearing range extends into
576-424: A college campus or parks, somebody brought them in because they thought it would be neat to have white squirrels around." Albert Meier, another biology professor at Western Kentucky University, added that: "... white squirrels rarely survive in the wild because they can't easily hide. But on a college campus, they are less likely to be consumed by other animals." Monophyly In biological cladistics for
672-511: A contagious prion agent in squirrels. Nonetheless, the Lancet article generated substantial media coverage, including articles in the New Yorker and New York Times . A 2015 case of CJD in a Pittsburgh man who had eaten squirrel brains played out similarly: the media seized on the patient's unconventional food choice, positing squirrel brains as the source of his disease. The doctor who made
768-516: A cylindrical, mica condenser by a high-frequency Poulsen arc at approximately 100 kHz and thus to generate an ultrasound beam for detecting submerged objects. The idea of locating underwater obstacles had been suggested prior by L. F. Richardson, following the Titanic disaster. Richardson had proposed to position a high-frequency hydraulic whistle at the focus of a mirror and use the beam for locating submerged navigational hazards. A prototype
864-475: A direct attempt to help the native red squirrel , which has been dwindling since the 19th-century introduction of the gray squirrel, resulting in dramatic habitat loss for the indigenous red squirrels. This factor was marketed by a national "Save Our Squirrels" campaign that used the slogan, "Save a red, eat a grey!" As with other wild game and fish species, the consumption of squirrels that have been exposed to high levels of pollution or toxic waste poses
960-427: A large grain size that produces a high level of background noise in measurements. Ultrasonic thickness measurement is one technique used to monitor quality of welds. A common use of ultrasound is in underwater range finding ; this use is also called sonar . An ultrasonic pulse is generated in a particular direction. If there is an object in the path of this pulse, part or all of the pulse will be reflected back to
1056-430: A newly hired policeman in trying to remove a frantic squirrel from a homeowner's living room, which results in personal injury and a small fire. First aired in 1998, this episode turned out to be one of the most popular ones of the series, prompting rebroadcasts and a lead position on the two-CD compilation Crimebusters + Crossed Wires: Stories from This American Life . One of the ways that squirrels affect human society
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#17327875162001152-461: A polyphyletic grouping are not inherited from a common ancestor, but evolved independently. Monophyletic groups are typically characterised by shared derived characteristics ( synapomorphies ), which distinguish organisms in the clade from other organisms. An equivalent term is holophyly . The word "mono-phyly" means "one-tribe" in Greek. These definitions have taken some time to be accepted. When
1248-500: A population of albino squirrels since the 1960s), and Youngstown State University in Youngstown, Ohio . Michael Stokes, a biology professor at Western Kentucky University, commented that the probable cause for the abundance of white squirrels on university campuses was because they were originally introduced by someone: "We're not sure how they got here, but I'll tell you how it usually happens...When you see them, especially around
1344-417: A pulsed-ultrasonic technology is that the transmit signal consists of short bursts of ultrasonic energy. After each burst, the electronics looks for a return signal within a small window of time corresponding to the time it takes for the energy to pass through the vessel. Only a signal received during this window will qualify for additional signal processing. A popular consumer application of ultrasonic ranging
1440-462: A single stash (a midden ) that tends to dry out, so the seeds don't take root. Fox squirrels and gray squirrels bury nuts over a widespread area ( scatterhoarding ), and often forget them, resulting in new trees ( mutualism ). In the Ramayana , an ancient Sanskrit epic poem , a squirrel assists in constructing a bridge from India to Sri Lanka to help Rama rescue his wife Sita . Rama rewards
1536-532: A squirrel on the other, serving as her messengers to the sky and the earth respectively. In Europe during the Middle Ages , squirrels were sometimes used in bestiaries as symbols of greed and avarice on account of their storing of nuts, but, in the nineteenth century, British natural history books often praised them as thrifty for this same reason. A myth told by the Ainu people of Japan holds that squirrels are
1632-451: A substantial reduction in the reaction time, like in the transesterification of oil into biodiesel . Substantial ultrasonic intensity and high ultrasonic vibration amplitudes are required for many processing applications, such as nano-crystallization, nano-emulsification, deagglomeration, extraction, cell disruption, as well as many others. Commonly, a process is first tested on a laboratory scale to prove feasibility and establish some of
1728-657: A substantial time commitment for continuous data collection and operator training. Nevertheless, this technology has proven useful in managing and running a cattle breeding operation. High-power applications of ultrasound often use frequencies between 20 kHz and a few hundred kHz. Intensities can be very high; above 10 watts per square centimeter, cavitation can be inducted in liquid media, and some applications use up to 1000 watts per square centimeter. Such high intensities can induce chemical changes or produce significant effects by direct mechanical action, and can inactivate harmful microorganisms. Ultrasound has been used since
1824-470: A very fine spray), is a popular type of humidifier. It works by vibrating a metal plate at ultrasonic frequencies to nebulize (sometimes incorrectly called "atomize") the water. Because the water is not heated for evaporation, it produces a cool mist. The ultrasonic pressure waves nebulize not only the water but also materials in the water including calcium, other minerals, viruses, fungi, bacteria, and other impurities. Illness caused by impurities that reside in
1920-486: Is sound with frequencies greater than 20 kilohertz . This frequency is the approximate upper audible limit of human hearing in healthy young adults. The physical principles of acoustic waves apply to any frequency range, including ultrasound. Ultrasonic devices operate with frequencies from 20 kHz up to several gigahertz. Ultrasound is used in many different fields. Ultrasonic devices are used to detect objects and measure distances. Ultrasound imaging or sonography
2016-413: Is a Real-Time Locating System (RTLS) or Indoor Positioning System (IPS) technology used to automatically track and identify the location of objects in real time using simple, inexpensive nodes (badges/tags) attached to or embedded in objects and devices, which then transmit an ultrasound signal to communicate their location to microphone sensors. The potential for ultrasonic imaging of objects, in which
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#17327875162002112-609: Is also increasingly being used in trauma and first aid cases, with emergency ultrasound being used by some EMT response teams. Furthermore, ultrasound is used in remote diagnosis cases where teleconsultation is required, such as scientific experiments in space or mobile sports team diagnosis. According to RadiologyInfo, ultrasounds are useful in the detection of pelvic abnormalities and can involve techniques known as abdominal (transabdominal) ultrasound, vaginal (transvaginal or endovaginal) ultrasound in women, and also rectal (transrectal) ultrasound in men. Diagnostic ultrasound
2208-449: Is also used to visualize fetuses during routine and emergency prenatal care . Such diagnostic applications used during pregnancy are referred to as obstetric sonography . As currently applied in the medical field, properly performed ultrasound poses no known risks to the patient. Sonography does not use ionizing radiation , and the power levels used for imaging are too low to cause adverse heating or pressure effects in tissue. Although
2304-565: Is an ultrasound-based diagnostic medical imaging technique used to visualize muscles, tendons, and many internal organs to capture their size, structure and any pathological lesions with real time tomographic images. Ultrasound has been used by radiologists and sonographers to image the human body for at least 50 years and has become a widely used diagnostic tool. The technology is relatively inexpensive and portable, especially when compared with other techniques, such as magnetic resonance imaging (MRI) and computed tomography (CT). Ultrasound
2400-494: Is applied. These frequencies range between 25 and 55 kHz, with the displacement amplitude of the resonant body of between 22 and 50 μm (0.00087 and 0.0020 in). UIT devices rely on magnetostrictive transducers. Ultrasonication offers great potential in the processing of liquids and slurries, by improving the mixing and chemical reactions in various applications and industries. Ultrasonication generates alternating low-pressure and high-pressure waves in liquids, leading to
2496-399: Is available because they cache the surplus. Squirrels living in parks and campuses in cities have learned that humans are typically a ready source of food, either deliberately or from careless disposal of surplus. Some people do " squirrel fishing " as a way of simultaneously playing with and feeding squirrels. Humans commonly offer various nuts and seeds; however, wildlife rehabilitators in
2592-420: Is called "direct scalability". It is important to point out that increasing the power of the ultrasonic processor alone does not result in direct scalability, since it may be (and frequently is) accompanied by a reduction in the ultrasonic amplitude and cavitation intensity. During direct scale-up, all processing conditions must be maintained, while the power rating of the equipment is increased in order to enable
2688-623: Is called a " drey ". Squirrels are a serious fire hazard when they break into buildings. They often treat exposed power cables as tree branches, and gnaw on the electrical insulation . The resulting exposed conductors can short out, causing a fire. For this reason alone, squirrel nests inside buildings cannot be safely ignored. A squirrel nest will also cause problems with noise, excreta , unpleasant odors, and eventual structural damage. Some homeowners resort to more interesting ways of dealing with this problem, such as collecting and placing fur from pets such as domestic cats and dogs in attics. It
2784-419: Is exposed to the weather. Poisoning squirrels can be problematic because of the risks to other animals or children in the building, and because the odor of a dead squirrel in an attic or wall cavity is very unpleasant and persistent. Trapping is often used to remove squirrels from residential structures. Effective baits include fruit, peanut butter , nuts, seeds and vanilla extract . An alternative method
2880-442: Is fed directly into the human skull and reaches the cochlea through bone conduction , without passing through the middle ear. Children can hear some high-pitched sounds that older adults cannot hear, because in humans the upper limit pitch of hearing tends to decrease with age. An American cell phone company has used this to create ring signals that supposedly are only audible to younger humans, but many older people can hear
2976-598: Is generally less than 1 watt per square centimetre to avoid heating and cavitation effects in the object under examination. Ultrasonic imaging applications include industrial nondestructive testing, quality control and medical uses. Acoustic microscopy is the technique of using sound waves to visualize structures too small to be resolved by the human eye. High and ultra high frequencies up to several gigahertz are used in acoustic microscopes. The reflection and diffraction of sound waves from microscopic structures can yield information not available with light. Medical ultrasound
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3072-497: Is home to a white squirrel population which has spurred the myth of the albino squirrel as a good luck charm. There are many versions of the tale; one of the more popular versions is if one spots the albino squirrel before an exam, they will ace it. The University of North Texas founded the Albino Squirrel Preservation Society in 2001, which has since acquired several "worldwide" chapters. In 2006,
3168-450: Is hoped that this fur would indicate to nesting squirrels that a potential predator roams, and will encourage evacuation. Odoriferous repellents, including mothballs and ammonia , are generally ineffective in expelling squirrels from buildings. Once established in a nest, squirrels ignore fake owls and scarecrows , along with bright flashing lights, loud noises, and ultrasonic or electromagnetic devices. However, squirrels must leave
3264-414: Is ineffective unless steps are taken to prevent them from immediately breaking in again. Squirrels are often the cause of power outages . They can readily climb a power pole and crawl or run along a power cable. The animals will climb onto power transformers or capacitors looking for food, or a place to cache acorns . If they touch a high voltage conductor and a grounded portion of the enclosure at
3360-422: Is inspired by the fascination that people seem to have over local populations of white squirrels (often misidentified as being albino). This manifests itself by the creation of social group communities that form from a commonly shared interest in these rare animals. Other impacts on human society inspired by white squirrels include the creation of organizations that seek to protect them from human predation , and
3456-496: Is no tracking system to determine the total extent of the losses. In regions where squirrels are plentiful, tire-flattened roadkill is a common sight on roadways, especially in the spring and fall, when there is a fresh crop of young rodents. Motorists have caused serious accidents by attempting to swerve or stop to avoid a squirrel in the road. Evasive maneuvers are difficult since squirrels are much more agile and have much quicker reaction times than motorists in heavy vehicles;
3552-422: Is often used in medicine. In the nondestructive testing of products and structures, ultrasound is used to detect invisible flaws. Industrially, ultrasound is used for cleaning, mixing, and accelerating chemical processes. Animals such as bats and porpoises use ultrasound for locating prey and obstacles. Acoustics , the science of sound , starts as far back as Pythagoras in the 6th century BC, who wrote on
3648-480: Is seeking to report and document the occurrence of both white squirrels, albinos, and other piebald morphs. Users are encouraged to submit their sightings. Olney, Illinois , known as the "White Squirrel Capital of the World", is home of the world's largest known white squirrel colony. These squirrels have the right of way on all streets in the town, with a $ 500 fine for hitting one. The Olney Police Department features
3744-425: Is to wait until squirrels have left in search of food, and then close up all their access openings, or to install one-way trap doors or a carefully angled pipe. Attempting to get rid of all squirrels in a neighborhood is generally a futile goal; the focus instead should be on physically excluding them from places where they can do damage. There are other humane techniques to remove squirrels from buildings, but removal
3840-455: Is used externally in horses for evaluation of soft tissue and tendon injuries, and internally in particular for reproductive work – evaluation of the reproductive tract of the mare and pregnancy detection. It may also be used in an external manner in stallions for evaluation of testicular condition and diameter as well as internally for reproductive evaluation (deferent duct etc.). By 2005, ultrasound technology began to be used by
3936-533: The Western , Central and Finger Lakes regions of New York State ( Buffalo , Rochester , Ithaca and Syracuse ). The Trinity Bellwoods neighborhood of Toronto , Ontario is locally known for white squirrel sightings. In addition to the various towns that boast of their white squirrel populations, a number of university campuses in North America have white squirrels. The University of Texas at Austin
Tree squirrel - Misplaced Pages Continue
4032-584: The red squirrel was hunted for its blue-gray winter coat, traditionally called vair , which now lends its name to a heraldic fur . The hairs from squirrel tails are prized in fly fishing when tying fishing flies . In many areas of the US, squirrels are still hunted for food, as they were historically. Recipes calling for squirrel even appear in cookbooks, including James Beard's American Cookery and pre-1997 copies of The Joy of Cooking . Squirrel meat can be substituted for rabbit or chicken in many recipes and
4128-953: The 1870s), the red squirrel of Eurasia, and the North American fox squirrel , among many others. Many tree squirrel species have adapted to human-altered environments such as rural farms , suburban backyards and urban parks . Current taxonomy , based on genetic data, splits the tree squirrels into several subfamilies. The following genera of the squirrel family are classified as tree squirrels. Squirrels are generally inquisitive and persistent animals. In residential neighborhoods, they are notorious for tenaciously trying to circumvent obstacles in order to eat from bird feeders . Although they are expert climbers, and primarily arboreal , some species of squirrels also thrive in urban environments, where they have adapted to humans. Squirrels have been kept as pets in Western society at least until
4224-581: The 1940s by physical and occupational therapists for treating connective tissue : ligaments , tendons , and fascia (and also scar tissue ). Conditions for which ultrasound may be used for treatment include the follow examples: ligament sprains , muscle strains , tendonitis , joint inflammation, plantar fasciitis , metatarsalgia , facet irritation, impingement syndrome , bursitis , rheumatoid arthritis , osteoarthritis , and scar tissue adhesion. Relatively high power ultrasound can break up stony deposits or tissue, increase skin permeability , accelerate
4320-528: The 1960s. Ultrasonic inspection eliminates the use of ionizing radiation, with safety and cost benefits. Ultrasound can also provide additional information such as the depth of flaws in a welded joint. Ultrasonic inspection has progressed from manual methods to computerized systems that automate much of the process. An ultrasonic test of a joint can identify the existence of flaws, measure their size, and identify their location. Not all welded materials are equally amenable to ultrasonic inspection; some materials have
4416-514: The 1980s. In 1997, doctors in Kentucky published a paper in the Lancet that considered a possible association between the local tradition of consuming squirrel brains and five cases of Creutzfeldt–Jakob disease , a rare but serious prion -based disorder. The authors posed this as a mere possibility, unconfirmed by either post-mortem analysis of the patients' brain tissue , or identification of
4512-526: The 19th century. Because of their small size and tame nature, they were especially popular with women and the clergy. Squirrels are sometimes considered pests because of their propensity to chew on various edible and inedible objects, and their stubborn persistence in trying to get what they want. Their characteristic gnawing trait also aids in maintaining sharp teeth , and because their teeth grow continuously, prevents their over-growth. On occasion, squirrels will chew through plastic and even metal to get to
4608-765: The Albino Squirrel Preservation Society, which maintains contact with its members and interested parties through a Facebook group by that name. The university has an open policy to give away a free t-shirt to anyone who takes a photograph of a white squirrel on campus grounds and brings it to the administration offices. Other university campuses that have albino squirrel populations include Oberlin College in Ohio, Ohio State University in Columbus, Ohio , Western Kentucky University in Bowling Green, Kentucky (which has had
4704-458: The MHz range. UHF ultrasound waves have been generated as high as the gigahertz range. Characterizing extremely high-frequency ultrasound poses challenges, as such rapid movement causes waveforms to steepen and form shock waves . The upper frequency limit in humans (approximately 20 kHz) is due to limitations of the middle ear . Auditory sensation can occur if high‐intensity ultrasound
4800-469: The UIT tool, made up of the ultrasonic transducer, pins and other components, comes into contact with the work piece it acoustically couples with the work piece, creating harmonic resonance. This harmonic resonance is performed at a carefully calibrated frequency, to which metals respond very favorably. Depending on the desired effects of treatment a combination of different frequencies and displacement amplitude
4896-572: The University of North Texas held a student referendum to name their white squirrel as the university's secondary mascot, but the vote was narrowly defeated by the student body. University of Wisconsin - Eau Claire has a significant white squirrel population both on the campus and in other areas of the city of Eau Claire . Michigan Technological University in Houghton, Michigan is home to frequently sighted white squirrels that live on and around
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#17327875162004992-466: The beef cattle industry to improve animal health and the yield of cattle operations. Ultrasound is used to evaluate fat thickness, rib eye area, and intramuscular fat in living animals. It is also used to evaluate the health and characteristics of unborn calves. Ultrasound technology provides a means for cattle producers to obtain information that can be used to improve the breeding and husbandry of cattle. The technology can be expensive, and it requires
5088-605: The campus. A Facebook group dedicated to these squirrels, called I've Seen the Albino Squirrel of Michigan Tech , was created for people to post photographs and anecdotes of their encounters with the white squirrels, and includes some stories from Michigan Tech alumni that recall seeing white squirrels in Houghton dating back to the 1930s. In Kentucky, the University of Louisville has established its own chapter of
5184-404: The cladistics school of thought became mainstream in the 1960s, several alternative definitions were in use. Indeed, taxonomists sometimes used terms without defining them, leading to confusion in the early literature, a confusion which persists. The first diagram shows a phylogenetic tree with two monophyletic groups. The several groups and subgroups are particularly situated as branches of
5280-689: The classification of organisms , monophyly is the condition of a taxonomic grouping being a clade – that is, a grouping of taxa which meets these criteria: Monophyly is contrasted with paraphyly and polyphyly as shown in the second diagram. A paraphyletic grouping meets 1. but not 2., thus consisting of the descendants of a common ancestor, excepting one or more monophyletic subgroups. A polyphyletic grouping meets neither criterion, and instead serves to characterize convergent relationships of biological features rather than genetic relationships – for example, night-active primates, fruit trees, or aquatic insects. As such, these characteristic features of
5376-759: The collapse of millions of microscopic cavitation bubbles near the dirty surface. The collapsing bubbles form tiny shockwaves that break up and disperse contaminants on the object's surface. Similar to ultrasonic cleaning, biological cells including bacteria can be disintegrated. High power ultrasound produces cavitation that facilitates particle disintegration or reactions. This has uses in biological science for analytical or chemical purposes ( sonication and sonoporation ) and in killing bacteria in sewage. High power ultrasound can disintegrate corn slurry and enhance liquefaction and saccharification for higher ethanol yield in dry corn milling plants. The ultrasonic humidifier, one type of nebulizer (a device that creates
5472-613: The discarded sandals of the ancestral deity Aioina, possibly because squirrels move in spurts like footsteps. The Kalevala , a Finnish epic poem collected in the nineteenth century but rooted in much older oral tradition , contains references to squirrels, including mention of a white squirrel being born of a virgin. Literary references to squirrels include the works of Beatrix Potter , Brian Jacques ' Redwall series (including Jess Squirrel and numerous other squirrels), Pattertwig in C. S. Lewis ' Prince Caspian , Michael Tod's Woodstock Saga of novels featuring squirrel communities in
5568-763: The effect of drugs in a targeted area, assist in the measurement of the elastic properties of tissue, and can be used to sort cells or small particles for research. Ultrasonic impact treatment (UIT) uses ultrasound to enhance the mechanical and physical properties of metals. It is a metallurgical processing technique in which ultrasonic energy is applied to a metal object. Ultrasonic treatment can result in controlled residual compressive stress, grain refinement and grain size reduction. Low and high cycle fatigue are enhanced and have been documented to provide increases up to ten times greater than non-UIT specimens. Additionally, UIT has proven effective in addressing stress corrosion cracking , corrosion fatigue and related issues. When
5664-413: The fact that a monophyletic group includes organisms (e.g., genera, species) consisting of all the descendants of a unique common ancestor. Conversely, the term polyphyly , or polyphyletic , builds on the ancient Greek prefix πολύς ( polús ), meaning "many, a lot of", and refers to the fact that a polyphyletic group includes organisms arising from multiple ancestral sources. By comparison,
5760-407: The field have noted that neither raw nor roasted peanuts nor sunflower seeds are healthy for squirrels, because they are deficient in several essential nutrients. This type of deficiency has been found to cause metabolic bone disease , a somewhat common ailment found in malnourished squirrels. Squirrels are sometimes hunted as game animals , whether for their fur or as food. In the Middle Ages
5856-515: The food. Tree squirrels may bury food in the ground for later retrieval. Squirrels use their keen sense of smell to search for buried food, but can dig numerous holes in the process. This may become an annoyance to gardeners with strict landscape requirements, especially when the garden contains edibles. Homeowners in areas with a heavy squirrel population must be vigilant in keeping attics , basements , and sheds carefully sealed to prevent property damage caused by nesting squirrels. A squirrel nest
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#17327875162005952-474: The formation and violent collapse of small vacuum bubbles. This phenomenon is termed cavitation and causes high speed impinging liquid jets and strong hydrodynamic shear-forces. These effects are used for the deagglomeration and milling of micrometre and nanometre-size materials as well as for the disintegration of cells or the mixing of reactants. In this aspect, ultrasonication is an alternative to high-speed mixers and agitator bead mills. Ultrasonic foils under
6048-428: The ground or among rocks. An exception is the flying squirrel that also makes its home in trees, but has a physiological distinction separating it from its tree squirrel cousins: special flaps of skin called patagia , acting as glider wings, which allow gliding flight . The best-known genus of tree squirrels is Sciurus , which includes the eastern gray squirrel of North America ( introduced to Great Britain in
6144-401: The hawk Veðrfölnir , who sits at the top of the tree keeping watch. According to Richard W. Thorington, Jr. and Katie E. Ferrell, this legend may have originated from the red squirrel's habit of giving a "scolding alarm call in response to danger", which some Norsemen may have imagined as insults. In Irish mythology , the goddess Medb is said to always have a bird perched on one shoulder and
6240-644: The hearing range of humans. The first article on the history of ultrasound was written in 1948. According to its author, during the First World War , a Russian engineer named Chilowski submitted an idea for submarine detection to the French Government. The latter invited Paul Langevin , then Director of the School of Physics and Chemistry in Paris, to evaluate it. Chilowski's proposal was to excite
6336-570: The highest known upper hearing limit at around 160 kHz. Several types of fish can detect ultrasound. In the order Clupeiformes , members of the subfamily Alosinae ( shad ) have been shown to be able to detect sounds up to 180 kHz, while the other subfamilies (e.g. herrings ) can hear only up to 4 kHz. No bird species have been reported to be sensitive to ultrasound. Commercial ultrasonic systems have been sold for supposed indoors electronic pest control and outdoors ultrasonic algae control . However, no scientific evidence exists on
6432-623: The image of a white squirrel on its officers' uniform patches. Along with Olney, there are four other towns in North America that avidly compete with each other to be the official "Home of the White Squirrel", namely: Marionville, Missouri ; Brevard, North Carolina ; Exeter, Ontario ; and Kenton, Tennessee , each of which holds an annual white squirrel festival, among other things designed to promote their claim of "White Squirrel Capital". A list of white squirrel sightings around
6528-442: The initial report later clarified that he had not meant to assert the squirrel meat was the cause. Analysis of the patient's brain tissue ruled out the possibility of CJD acquired from food. As of 2018, Creutzfeldt–Jakob disease had never been identified in squirrels, and the association between squirrel consumption and CJD remained speculative. The biggest source of food for tree squirrels is tree nuts . Red squirrels store nuts in
6624-505: The invasive gray squirrel , which is praised for its low fat content and the fact that it comes from free range sources. Additionally, the novelty of a meat considered unusual or special has contributed to the spread of squirrel consumption. Due to the difficulty of a clean kill and other factors, the majority of squirrel eaten in the UK is acquired from professional hunters , trappers and gamekeepers . Some Britons are eating gray squirrel as
6720-571: The layout of rooms. Although range finding underwater is performed at both sub-audible and audible frequencies for great distances (1 to several kilometers), ultrasonic range finding is used when distances are shorter and the accuracy of the distance measurement is desired to be finer. Ultrasonic measurements may be limited through barrier layers with large salinity, temperature or vortex differentials. Ranging in water varies from about hundreds to thousands of meters, but can be performed with centimeters to meters accuracy Ultrasound Identification (USID)
6816-545: The long-term effects due to ultrasound exposure at diagnostic intensity are still unknown, currently most doctors feel that the benefits to patients outweigh the risks. The ALARA (As Low As Reasonably Achievable) principle has been advocated for an ultrasound examination – that is, keeping the scanning time and power settings as low as possible but consistent with diagnostic imaging – and that by that principle nonmedical uses, which by definition are not necessary, are actively discouraged. Ultrasound
6912-626: The majority of vehicular encounters end with no harm to either party. An effort to mitigate these hazards to both squirrels and humans is the Nutty Narrows Bridge in Longview, Washington , listed on the National Register of Historic Places . It provides a way for squirrels to cross a busy street safely. Tree squirrels are a common type of urban wildlife . They can be trained to be hand-fed, and will take as much food as
7008-496: The mathematical properties of stringed instruments . Echolocation in bats was discovered by Lazzaro Spallanzani in 1794, when he demonstrated that bats hunted and navigated by inaudible sound, not vision. Francis Galton in 1893 invented the Galton whistle , an adjustable whistle that produced ultrasound, which he used to measure the hearing range of humans and other animals, demonstrating that many animals could hear sounds above
7104-470: The moving wire in a paper machine will use the shock waves from the imploding bubbles to distribute the cellulose fibres more uniformly in the produced paper web, which will make a stronger paper with more even surfaces. Furthermore, chemical reactions benefit from the free radicals created by the cavitation as well as from the energy input and the material transfer through boundary layers. For many processes, this sonochemical (see sonochemistry ) effect leads to
7200-452: The nest to obtain food and water (usually daily, except in bad weather), affording an opportunity to trap them or exclude them from re-entering. To discourage chewing on an object, it can be coated or covered with something to make it distasteful: for instance a soft cloth doused with chili pepper paste or powder. Capsaicin and Ro-pel are other forms of repellent. To remain effective, the coating must be reapplied regularly, especially if it
7296-546: The operation of a larger ultrasonic horn. A researcher at the Industrial Materials Research Institute, Alessandro Malutta, devised an experiment that demonstrated the trapping action of ultrasonic standing waves on wood pulp fibers diluted in water and their parallel orienting into the equidistant pressure planes. The time to orient the fibers in equidistant planes is measured with a laser and an electro-optical sensor. This could provide
7392-778: The paper industry a quick on-line fiber size measurement system. A somewhat different implementation was demonstrated at Pennsylvania State University using a microchip which generated a pair of perpendicular standing surface acoustic waves allowing to position particles equidistant to each other on a grid. This experiment, called acoustic tweezers , can be used for applications in material sciences, biology, physics, chemistry and nanotechnology. Ultrasonic cleaners , sometimes mistakenly called supersonic cleaners , are used at frequencies from 20 to 40 kHz for jewellery, lenses and other optical parts, watches, dental instruments , surgical instruments , diving regulators and industrial parts. An ultrasonic cleaner works mostly by energy released from
7488-423: The required ultrasonic exposure parameters. After this phase is complete, the process is transferred to a pilot (bench) scale for flow-through pre-production optimization and then to an industrial scale for continuous production. During these scale-up steps, it is essential to make sure that all local exposure conditions (ultrasonic amplitude, cavitation intensity, time spent in the active cavitation zone, etc.) stay
7584-903: The same time, they are electrocuted , and often cause a short circuit that shuts down equipment. Squirrels have brought down the high-tech NASDAQ stock market twice and were responsible for a spate of power outages at the University of Alabama . To sharpen their teeth, squirrels will often chew on tree branches or even the occasional live power line. Rubber or plastic plates, or freely rotating sleeves ("squirrel guards") are sometimes used to discourage access to these facilities. Squirrels otherwise appear to be safe and pose almost zero risk of transmitting rabies . Squirrels cause economic losses to homeowners, nut growers, and forest managers in addition to damage to electric transmission lines. These losses include direct damage to property, repairs, lost revenue and public relations. While dollar costs of these losses are sometimes calculated for isolated incidents, there
7680-480: The same. If this condition is met, the quality of the final product remains at the optimized level, while the productivity is increased by a predictable "scale-up factor". The productivity increase results from the fact that laboratory, bench and industrial-scale ultrasonic processor systems incorporate progressively larger ultrasonic horns , able to generate progressively larger high-intensity cavitation zones and, therefore, to process more material per unit of time. This
7776-518: The signals, which may be because of the considerable variation of age-related deterioration in the upper hearing threshold. Bats use a variety of ultrasonic ranging ( echolocation ) techniques to detect their prey. They can detect frequencies beyond 100 kHz, possibly up to 200 kHz. Many insects have good ultrasonic hearing, and most of these are nocturnal insects listening for echolocating bats. These include many groups of moths , beetles , praying mantises and lacewings . Upon hearing
7872-477: The squirrel by stroking his back with his three middle fingers, thus giving the Indian palm squirrel the three white stripes that appear on its back. In Norse mythology , the squirrel Ratatoskr is a messenger who scurries up and down the trunk of the world-tree Yggdrasil , carrying malicious gossip and insults back and forth between the dragon Níðhöggr , who sits at the bottom of the tree gnawing on its roots, and
7968-657: The style of Watership Down , and the Starwife and her subjects from Robin Jarvis 's Deptford novels. The title character in Miriam Young 's 1964 children's book Miss Suzy is a squirrel. Anthropomorphic red squirrels were used in British road safety campaigns between the 1950s and 1980s. An episode of the radio program This American Life called "Squirrel Cop" describes the unintentionally humorous misadventure of
8064-421: The success of such devices for these purposes. An ultrasonic level or sensing system requires no contact with the target. For many processes in the medical, pharmaceutical, military and general industries this is an advantage over inline sensors that may contaminate the liquids inside a vessel or tube or that may be clogged by the product. Both continuous wave and pulsed systems are used. The principle behind
8160-593: The term paraphyly , or paraphyletic , uses the ancient Greek prefix παρά ( pará ), meaning "beside, near", and refers to the situation in which one or several monophyletic subgroups are left apart from all other descendants of a unique common ancestor. That is, a paraphyletic group is nearly monophyletic, hence the prefix pará . On the broadest scale, definitions fall into two groups. The concepts of monophyly, paraphyly , and polyphyly have been used in deducing key genes for barcoding of diverse group of species. Ultrasonic Ultrasound
8256-547: The thickness of objects. Frequencies of 2 to 10 MHz are common, but for special purposes other frequencies are used. Inspection may be manual or automated and is an essential part of modern manufacturing processes. Most metals can be inspected as well as plastics and aerospace composites . Lower frequency ultrasound (50–500 kHz) can also be used to inspect less dense materials such as wood, concrete and cement . Ultrasound inspection of welded joints has been an alternative to radiography for nondestructive testing since
8352-495: The transmitter as an echo and can be detected through the receiver path. By measuring the difference in time between the pulse being transmitted and the echo being received, it is possible to determine the distance. The measured travel time of Sonar pulses in water is strongly dependent on the temperature and the salinity of the water. Ultrasonic ranging is also applied for measurement in air and for short distances. For example, hand-held ultrasonic measuring tools can rapidly measure
8448-493: The tree to indicate ordered lineal relationships between all the organisms shown. Further, any group may (or may not) be considered a taxon by modern systematics , depending upon the selection of its members in relation to their common ancestor(s); see second and third diagrams. The term monophyly , or monophyletic , derives from the two Ancient Greek words μόνος ( mónos ), meaning "alone, only, unique", and φῦλον ( phûlon ), meaning "genus, species", and refers to
8544-467: The ultrasound can cover a wide area from a single point. The flow in pipes or open channels can be measured by ultrasonic flowmeters, which measure the average velocity of flowing liquid. In rheology , an acoustic rheometer relies on the principle of ultrasound. In fluid mechanics , fluid flow can be measured using an ultrasonic flow meter . Ultrasonic testing is a type of nondestructive testing commonly used to find flaws in materials and to measure
8640-594: The ultrasound; the top end of a dog's hearing range is about 45 kHz, while a cat's is 64 kHz. The wild ancestors of cats and dogs evolved this higher hearing range to hear high-frequency sounds made by their preferred prey, small rodents. A dog whistle is a whistle that emits ultrasound, used for training and calling dogs. The frequency of most dog whistles is within the range of 23 to 54 kHz. Toothed whales , including dolphins , can hear ultrasound and use such sounds in their navigational system ( biosonar ) to orient and to capture prey. Porpoises have
8736-475: The use of the white squirrel image as a cultural icon . Although these squirrels are commonly referred to as "albinos", most of them are likely non-albino squirrels that exhibit a rare white fur coloration known as leucism that is as a result of a recessive gene found within certain eastern gray squirrel ( Sciurus carolinensis ) populations, and so technically they ought to be referred to as white squirrels, instead of albino . A project run by Untamed Science
8832-555: The world is maintained by the White Squirrel Research Institute, a group based in Brevard, North Carolina. Other towns that have reported white squirrel populations in North America (although not necessarily competing to be the "official" white squirrel capital) include Bowling Green, Kentucky ; Columbia, Mississippi ; DeForest, Wisconsin ; Stratford, Connecticut ; and some of the snowbelt cities in
8928-539: Was an ingredient in the original recipe for Brunswick stew , a popular dish in various parts of the Southern US. Other similar stews were also based on squirrel meat, including burgoo and Southern Illinois chowder . Although squirrel meat is low in fat content, unlike most game meat it has been found by the American Heart Association to be high in cholesterol . Squirrels Unlimited host
9024-435: Was built by Sir Charles Parsons , the inventor of the vapour turbine , but the device was found not to be suitable for this purpose. Langevin's device made use of the piezoelectric effect , which he had been acquainted with whilst a student at the laboratory of Jacques and Pierre Curie . Langevin calculated and built an ultrasound transducer comprising a thin sheet of quartz sandwiched between two steel plates. Langevin
9120-481: Was the Polaroid SX-70 camera, which included a lightweight transducer system to focus the camera automatically. Polaroid later licensed this ultrasound technology and it became the basis of a variety of ultrasonic products. A common ultrasound application is an automatic door opener, where an ultrasonic sensor detects a person's approach and opens the door. Ultrasonic sensors are also used to detect intruders;
9216-581: Was the first to report cavitation -related bioeffects from ultrasound. Ultrasound is defined by the American National Standards Institute as " sound at frequencies greater than 20 kHz". In air at atmospheric pressure, ultrasonic waves have wavelengths of 1.9 cm or less. Ultrasound can be generated at very high frequencies; ultrasound is used for sonochemistry at frequencies up to multiple hundreds of kilohertz. Medical imaging equipment uses frequencies in
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