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À l'intérieur des valves vides, on peut voir une ligne brillante parallèle au bord extérieur de la coquille et qui relie souvent les muscles adducteurs. Dans un premier temps ils étaient utilisés plus dans un but décoratif que pour attacher les vêtements, et le plus ancien exemple connu a été retrouvé à Mohenjo-daro dans la vallée de l' Indus [ ]. La tribu des Winnebagos dans le Wisconsin utilisait les moules d'eau douce de différentes espèces, et s'en servait notamment de cuillères ou de tasses. Les bivalves Bivalvia sont une classe de mollusques d'eau douce et d'eau de mer, nommée également Pelecypoda les pélécypodes ou Lamellibranchia les lamellibranches. Axe on Pinterest
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The ULs do not apply to individuals receiving zinc for medical treatment, but such individuals should be under the care of a physician who monitors them for adverse health effects. Zinc supplements have the potential to interact with several types of medications. A few examples are provided below. Individuals taking these medications on a regular basis should discuss their zinc intakes with their healthcare providers. Taking the antibiotic at least 2 hours before or 4—6 hours after taking a zinc supplement minimizes this interaction [ 86 ].
Zinc can reduce the absorption and action of penicillamine, a drug used to treat rheumatoid arthritis [ 87 ].
To minimize this interaction, individuals should take zinc supplements at least 2 hours before or after taking penicillamine [ 85 ]. Prolonged use of thiazide diuretics could deplete zinc tissue levels, so clinicians should monitor zinc status in patients taking these medications.
The federal government's Dietary Guidelines for Americans notes that "Nutritional needs should be met primarily from foods. Foods in nutrient-dense forms contain essential vitamins and minerals and also dietary fiber and other naturally occurring substances that may have positive health effects.
In some cases, fortified foods and dietary supplements may be useful in providing one or more nutrients that otherwise may be consumed in less-than-recommended amounts. For more information about building a healthy diet, refer to the Dietary Guidelines for Americans and the U. Department of Agriculture's MyPlate. This fact sheet by the Office of Dietary Supplements ODS provides information that should not take the place of medical advice. We encourage you to talk to your healthcare providers doctor, registered dietitian, pharmacist, etc.
Any mention in this publication of a specific product or service, or recommendation from an organization or professional society, does not represent an endorsement by ODS of that product, service, or expert advice. March 2, History of changes to this fact sheet. Strengthening Knowledge and Understanding of Dietary Supplements. Zinc Fact Sheet for Health Professionals. J Lab Clin Med ; National Academy Press, Mild human zinc deficiency produces an imbalance between cell-mediated and humoral immunity.
Zinc deficiency and taste disorders. Zinc in the fetus and newborn. Acta Paediatr Scand Suppl ; Zinc, human diseases and aging. Zinc requirements and the risks and benefits of zinc supplementation. J Trace Elem Med Biol ; Proc Assoc Am Physicians ; Zinc and the immune system. Proc Nutr Soc ; Department of Agriculture, Agricultural Research Service.
Nutrient Data Laboratory Home Page, http: Eur J Clin Nutr ;51 1 Suppl: Phytate and zinc bioavailability. Int J Food Sci Nutr ; Anosmia after intranasal zinc gluconate use. Am J Rhinol ; Intranasal zinc and anosmia: Food and Drug Administration. Nat Clin Pract Neurol. Dietary intake of vitamins, minerals, and fiber of persons ages 2 months and over in the United States: Advance data from vital and health statistics no National Center for Health Statistics.
Government Printing Office, Mineral intakes of elderly adult supplement and non-supplement users in the third national health and nutrition examination survey. Dynamics of Poverty and Food Sufficiency.
Food Assistance and Nutrition Report Number 36, Department of Agriculture, Economic Research Service. Dietary intakes and serum nutrients differ between adults from food-insufficient and food-sufficient families: Met Ions Biol Syst ; Images in clinical medicine. N Engl J Med ; Zinc in Human Biology. Modern Nutrition in Health and Disease, 10th ed. Krasovec M, Frenk E. Acrodermatitis enteropathica secondary to Crohn's disease. Effect of marginal zinc deficiency on human growth and development.
J Trop Pediatr ; J Am Coll Nutr ; Bioavailability of iron, zinc, and other trace minerals from vegetarian diets. Am J Clin Nutr ;78 3 Suppl: Clinical and laboratory assessment of zinc deficiency in Dutch children. Biol Trace Elem Res ; Zinc deficiency in women, infants and children. The value of methods to determine zinc deficiency in patients with Crohn's disease.
Scand J Gastroenterol ; Zinc absorption in inflammatory bowel disease. J Am Diet Assoc ; Potential contribution of maternal zinc supplementation during pregnancy to maternal and child survival. Am J Clin Nutr ;68 2 Suppl: Zinc supplementation during lactation. Zinc supplementation and children's growth: Bibl Nutr Dieta ; Plasma zinc status, growth, and maturation in children with sickle cell disease. Effect of zinc supplementation on growth and body composition in children with sickle cell disease.
Am J Clin Nutr ; Zinc deficiency in patients with sickle cell disease. Zinc prevention and treatment of alcoholic liver disease. Mol Aspects Med ; Zinc deficiency and corticosteroids in the pathogenesis of alcoholic brain dysfunction—a review. Alcohol Clin Exp Res ; Role of zinc in the process of pancreatic fibrosis in chronic alcoholic pancreatitis.
Zinc and immune function: Contribution of selected vitamins and trace elements to immune function. In science, metric use is essentially universal, though additional specialized units are often used for specific purposes in various disciplines such as the parsec and light year in astronomy , consistent with worldwide use.
Earth sciences, such as hydrology and geology , continue to use customary units for field surveying , due both to the legacy of many decades of data collection and to the need to work with the construction industry, which has not adopted the metric system. Meteorology extensively uses both metric and customary units. The METAR reporting system in use in the United States differs from the one used by the World Meteorological Organization WMO in that wind speeds are delivered in knots instead of meters per second , water-equivalent precipitation in hundredths of an inch, and altimeter setting in the customary inches of mercury instead of hectopascals.
Most synoptic observation charts are expressed in SI units, except for the aforementioned wind speeds, which must be converted for the purposes of calculation. Upper-air temperature charts typically use the Celsius scale the freezing line is of great importance at lower levels of the atmosphere in determining precipitation type while potential temperature charts use the kelvin ; both of these are in line with international usage. Atmospheric vorticity is typically measured in full rotations per , seconds a rough metrication of the day but does not use the SI-recommended radian.
Actual sleet and snowfall and their depths on the ground are measured in tenths of an inch, with actual rainfall in hundredths, and ice accretion in either fractions or decimals. Hailstone sizes are typically reported without a fixed unit of measure; they are instead compared to familiar round or spherical items e.
Barometer readings for hurricanes are usually given in millibars mb , which are equal to hectopascals hPa , or ten times the kilopascals kPa used in neighboring Canada; the use of inches of mercury in such applications is rapidly declining. In early , NASA announced that it would use metric units for all operations on the lunar surface upon its return to the Moon, then projected for The medical field uses predominantly metric units.
When interacting with patients certain data, such as their height and weight, is presented in customary units. Both prescription and non-prescription dosages of pills are always measured in the SI system with the most common unit being the milligram. Smaller dosages use micrograms. For vitamins, nutrient amounts are given in gram denominations or WHO standardized international units , known as IU.
The sizes of pill containers, when occasionally spoken of, are predominantly discussed in terms of fluid drams , although most also contain cubic centimeters and sometimes fluid ounces on the specifications. For a long time, liquid dosages of medication were displayed in terms of both milliliters and the customary units of teaspoons and tablespoons, which are standardized as equal to 5 and 15 mL respectively.
However, many people colloquially refer to the small spoon in a utensil set as the teaspoon and the big spoon as the tablespoon. To assist in this transition, drug makers and pharmacies are encouraged to include a disposable measuring cup with liquid medications.
Medicine dosage guidelines are specified in terms of milligrams per kilogram. American blood glucose meters have the ability to switch between the two.
Blood and urine samples are taken by the milliliter. To avoid confusion, a 1-liter bag is noted as mL. Anthropometric data such as height may be recorded in centimeters. Even if the medical practice takes height and weight data in terms of SI units, it is almost always discussed with the patient in terms of customary units. Exercise is commonly discussed with patients in terms of miles walked.
Intake of sugar, sodium, and other nutrients is usually discussed in terms of grams and milligrams. Use among veterinarians varies, but because of the heavy emphasis on public interaction, animal weights e. Usage at veterinary teaching hospitals , by contrast, favors the SI units. Accurate sound level measurement devices were not invented until after the microphone  or for that matter after the proliferation of the SI system in physics and internationally.
Hence, although certain information on sound pressure can theoretically be evaluated in terms of pounds per square inch PSI , this is virtually never done. Instead, the internationally used decibel dB scale is most common. For example, appliance noise level is usually rated in terms of sone output. While the track and field Olympic Trials have always been conducted in metric distances, in order to duplicate the competition the selected athletes are destined for, the National Championships changed to metric in In the Olympics, athletes run meters, not meters.
Running races in the U. But even 5 and 10 kilometer races most often have mile markers on the course, and no kilometer markers. The marathon is referred to as a Ultramarathons are measured in either miles or kilometers, with little standardization either way.
Although the Olympics and U. Measured distances as used in events such as shot put , high jump , and discus throw are, however, often in feet and inches, except at the national and international levels.
In , the Florida High School Athletic Association became the first to buck this trend and use metric measures for field events.
This is reflected in American football , in which the playing field is divided into yards, and many important statistics are measured in yards.
Similarly, the dimensions for all baseball parks, basketball courts, tennis courts and ice hockey rinks are given in feet, golf courses in yards, auto racing tracks in miles or fractions thereof , and horse racing in furlongs. The lengths of automobile races in the U. On the other hand, some sporting equipment, such as skis and poles , is sold in metric units. A novelty American football game was attempted in metric units in Bicycles, especially at the high end, are increasingly being sold and sized in metric units.
Common swimming pool dimensions are yard, meter, and meter. The Olympic-size swimming pool is specified solely in meters. High schools and the NCAA conduct yard competitions. In the game of Ultimate Frisbee , the g flying disc is seen as a standard of the sport. The long-distance trail Mid State Trail has used metric units exclusively in its trail guide since USA Weightlifting uses metric units to measure weight. Signage on this road is, however, being converted back to customary units as it is replaced.
Another exception is the turnpike section of Delaware Route 1 , which uses a kilometer-based system, in anticipation of the mids conversion in the U. The exit numbers have remained metric starting at the Dover Air Force Base northward to Interstate Metric signs, including speed signs in kilometers per hour, were displayed in the manual even though they were not normally used on the roads and there was no definite plan to go metric.
Metric signs and metric measurements were removed for the edition and replaced with an appendix of metric conversion tables. This is in marked contrast to the position in the largely metric United Kingdom , where metric road signs are prohibited by law except for those denoting widths and height restrictions, which include both metric and imperial units.
The Maine Turnpike has metric measurements on its highway signs in addition to customary measurements, partly to assist the large numbers of Canadian tourists who visit Maine's beaches. The first signs in metric in the United States were posted on February 12, , on Interstate 71 in Ohio.
Gasoline and diesel fuel are sold by the U. Gasoline is dispensed in liters in Puerto Rico. Automobile crankcase oil is sold by the quart, antifreeze by the gallon, brake fluid by the ounce fluid , and air conditioning refrigerant by the ounce mass. Windshield wiper replacement blades are measured in inches. Domestic airline flights are assigned altitudes in feet and measure speed in knots. Nautical charts show depth in fathoms and use the nautical mile for distance.
One minute of arc of latitude at the radius of the earth at sea level was the standard for one nautical mile until about The nautical mile is now defined as exactly 1, meters.
Odometers are permitted to record miles or kilometers, but must be clearly labeled as to which unit they record. Tire inflation for passenger cars is typically about 30 pounds per square inch psi or kilopascals kPa. This is displayed on tires beside its metric equivalent.
Post model year regulations also mandate an internationally standard "Tire and Loading Information" sticker which gives capacities in SI units followed by customary equivalents. Some measurements are reported in units derived from both customary and metric units. For properties understood more recently, such as those related to electricity, there is no traditional unit; international units are always used, often in combination with U.
Other units are based on customary units, but use power-of-ten factors and metric prefixes. For example, distance to target for a U. Telephone transmission line length and loop distances are measured in kilofeet. The continuing use of U. Many authors have assumed that the United States and the human race in general will use metric units; however, others have assumed the continued use of U.
Writers sometimes use customary units simply because American readers and watchers will understand the measurements; other times, they are simply used by accident. The show Star Trek , for instance, initially used U.
Later, starting with " The Changeling ", metric measures were used, albeit inconsistently. Later sequels of the show, such as Star Trek: The Next Generation , and Star Trek: Enterprise set in the 22nd century , used the metric system exclusively. Both the metric system and attitudes in the U. Jackson that "Europe is a little different", because for example in Paris , they don't call it a " Quarter Pounder with Cheese" but a "Royale with Cheese" as "they've got the metric system, they don't know what the fuck a Quarter Pounder is".
Later, Jules compliments the intelligence of one of their victims, after he correctly surmises that French use of the metric system is what precludes the term "Quarter Pounder. From Wikipedia, the free encyclopedia. United States customary units. This article needs additional citations for verification. Please help improve this article by adding citations to reliable sources.
Unsourced material may be challenged and removed. January Learn how and when to remove this template message. United States Department of Commerce. Hassler's legacy A lasting live's work for surveying the world". Government of Utah archives. Retrieved 20 September Meter Stick for American Metric Bureau". The National Museum of American History. A Dictionary of Units of Measurement. The United States system of units is similar to the British imperial system. The customary system was championed by the U.
Advocates of the customary system saw the French Revolutionary, or metric, system as atheistic. The legislation states that the federal government has a responsibility to assist industry as it voluntarily converts to the metric system, i. This is most evident in U. According to the CIA Factbook , the United States is one of three nations along with Liberia and Burma that have not adopted the metric system as their official system of weights and measures.
Metric units are standard in science, medicine, as well as many sectors of industry and government, including the military. The metric system also lacks a parallel to the foot. For measuring length, the U. The SPCSs were also updated, but the National Geodetic Survey left the decision of which if any definition of the foot to use to the individual states.
Twenty-four states have legislated that surveying measures should be based on the US survey foot, eight have legislated that they be made on the basis of the international foot, and eighteen have not specified the conversion factor from metric units. The most widely used area unit with a name unrelated to any length unit is the acre. The National Institute of Standards and Technology contends that customary area units are defined in terms of the square survey foot, not the square international foot.
The cubic inch , cubic foot and cubic yard are commonly used for measuring volume. In addition, there is one group of units for measuring volumes of liquids, and one for measuring volumes of dry material. Other than the cubic inch, cubic foot and cubic yard, these units are differently sized from the units in the imperial system , although the names of the units are similar. Also, while the U. Consequently, a fluid ounce of water weighs about 1.
There are varying standards for barrel for some specific commodities, including 31 gal for beer, 40 gal for whiskey or kerosene, and 42 gal for petroleum. The general standard for liquids is The common 55 gallon size of drum for storing and transporting various products and wastes is sometimes confused with a barrel, though it is not a standard measure. Milk is usually sold in half pints 8 fluid ounces , pints, quarts, half gallons, and gallons.
Water volume for sinks, bathtubs, ponds, swimming pools, etc. Quantities of gases are usually given in cubic feet at one atmosphere. Dry volume is measured on a separate system, although many of the names remain the same. Small fruits and vegetables are often sold in dry pints and dry quarts.
The US dry gallon is less commonly used, and was not included in the handbook that many states recognize as the authority on measurement law. There have historically been five different English systems of mass: Of these, the avoirdupois weight is the most common system used in the U. Apothecaries weight—once used by pharmacies—has been largely replaced by metric measurements. Tower weight fell out of use in England due to legal prohibition in centuries ago, and was never used in the U.
The imperial system, which is still used for some measures in the United Kingdom and other Commonwealth countries, is based on avoirdupois, with variations from U. The pound avoirdupois, which forms the basis of the U. Other units of mass are defined in terms of it.