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Wednesday, February 13, 2019

Beer (updated)

From Wikipedia, the free encyclopedia

Beer
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Schlenkerla Rauchbier, a traditional smoked beer, being poured from a cask
Main ingredientscereal grains, Alcohol, water

Beer is one of the oldest and most widely consumed alcoholic drinks in the world, and the third most popular drink overall after water and tea. Beer is brewed from cereal grains—most commonly from malted barley, though wheat, maize (corn), and rice are also used. During the brewing process, fermentation of the starch sugars in the wort produces ethanol and carbonation in the resulting beer. Most modern beer is brewed with hops, which add bitterness and other flavors and act as a natural preservative and stabilizing agent. Other flavoring agents such as gruit, herbs, or fruits may be included or used instead of hops. In commercial brewing, the natural carbonation effect is often removed during processing and replaced with forced carbonation.

Some of humanity's earliest known writings refer to the production and distribution of beer: the Code of Hammurabi included laws regulating beer and beer parlors, and "The Hymn to Ninkasi", a prayer to the Mesopotamian goddess of beer, served as both a prayer and as a method of remembering the recipe for beer in a culture with few literate people.

Beer is distributed in bottles and cans and is also commonly available on draught, particularly in pubs and bars. The brewing industry is a global business, consisting of several dominant multinational companies and many thousands of smaller producers ranging from brewpubs to regional breweries. The strength of modern beer is usually around 4% to 6% alcohol by volume (ABV), although it may vary between 0.5% and 20%, with some breweries creating examples of 40% ABV and above.

Beer forms part of the culture of many nations and is associated with social traditions such as beer festivals, as well as a rich pub culture involving activities like pub crawling and pub games.

History

Egyptian wooden model of beer making in ancient Egypt, Rosicrucian Egyptian Museum, San Jose, California
 
Beer is one of the world's oldest prepared drinks. The earliest archaeological evidence of fermentation consists of 13,000 year old residues of a beer with the consistency of gruel, used by the semi-nomadic Natufians for ritual feasting, at the Raqefet Cave in the Carmel Mountains near Haifa in Israel. There is evidence that beer was produced at Göbekli Tepe during the Pre-Pottery Neolithic (around 8500 BC to 5500 BC). The earliest clear chemical evidence of beer produced from barley dates to about 3500–3100 BC, from the site of Godin Tepe in the Zagros Mountains of western Iran. It is possible, but not proven, that it dates back even further — to about 10,000 BC, when cereal was first farmed. Beer is recorded in the written history of ancient Iraq and ancient Egypt, and archaeologists speculate that beer was instrumental in the formation of civilizations. Approximately 5000 years ago, workers in the city of Uruk (modern day Iraq) were paid by their employers in beer. During the building of the Great Pyramids in Giza, Egypt, each worker got a daily ration of four to five liters of beer, which served as both nutrition and refreshment that was crucial to the pyramids' construction.

Some of the earliest Sumerian writings contain references to beer; examples include a prayer to the goddess Ninkasi, known as "The Hymn to Ninkasi", which served as both a prayer as well as a method of remembering the recipe for beer in a culture with few literate people, and the ancient advice (Fill your belly. Day and night make merry) to Gilgamesh, recorded in the Epic of Gilgamesh, by the ale-wife Siduri may, at least in part, have referred to the consumption of beer. The Ebla tablets, discovered in 1974 in Ebla, Syria, show that beer was produced in the city in 2500 BC. A fermented drink using rice and fruit was made in China around 7000 BC. Unlike sake, mold was not used to saccharify the rice (amylolytic fermentation); the rice was probably prepared for fermentation by chewing or malting.

Almost any substance containing sugar can naturally undergo alcoholic fermentation. It is likely that many cultures, on observing that a sweet liquid could be obtained from a source of starch, independently invented beer. Bread and beer increased prosperity to a level that allowed time for development of other technologies and contributed to the building of civilizations.

Xenophon noted that during his travels, beer was being produced in Armenia.

François Jaques: Peasants Enjoying Beer at Pub in Fribourg (Switzerland, 1923)
 
Beer was spread through Europe by Germanic and Celtic tribes as far back as 3000 BC, and it was mainly brewed on a domestic scale. The product that the early Europeans drank might not be recognized as beer by most people today. Alongside the basic starch source, the early European beers might contain fruits, honey, numerous types of plants, spices and other substances such as narcotic herbs. What they did not contain was hops, as that was a later addition, first mentioned in Europe around 822 by a Carolingian Abbot and again in 1067 by abbess Hildegard of Bingen.

In 1516, William IV, Duke of Bavaria, adopted the Reinheitsgebot (purity law), perhaps the oldest food-quality regulation still in use in the 21st century, according to which the only allowed ingredients of beer are water, hops and barley-malt. Beer produced before the Industrial Revolution continued to be made and sold on a domestic scale, although by the 7th century AD, beer was also being produced and sold by European monasteries. During the Industrial Revolution, the production of beer moved from artisanal manufacture to industrial manufacture, and domestic manufacture ceased to be significant by the end of the 19th century. The development of hydrometers and thermometers changed brewing by allowing the brewer more control of the process and greater knowledge of the results. 

As of 2007, the brewing industry is a global business, consisting of several dominant multinational companies and many thousands of smaller producers ranging from brewpubs to regional breweries. As of 2006, more than 133 billion liters (35 billion gallons), the equivalent of a cube 510 meters on a side, of beer are sold per year, producing total global revenues of $294.5 billion (£147.7 billion). In 2010, China's beer consumption hit 450 million hectoliters (45 billion liters), or nearly twice that of the United States, but only 5 per cent sold were premium draught beers, compared with 50 per cent in France and Germany.

A recent and widely publicized study suggests that sudden decreases in barley production due to extreme drought and heat could in the future cause substantial volatility in the availability and price of beer.

Brewing

The process of making beer is known as brewing. A dedicated building for the making of beer is called a brewery, though beer can be made in the home and has been for much of its history. A company that makes beer is called either a brewery or a brewing company. Beer made on a domestic scale for non-commercial reasons is classified as home brewing regardless of where it is made, though most home brewed beer is made in the home. Brewing beer is subject to legislation and taxation in developed countries, which from the late 19th century largely restricted brewing to a commercial operation only. However, the UK government relaxed legislation in 1963, followed by Australia in 1972 and the US in 1978, allowing home brewing to become a popular hobby. 

The purpose of brewing is to convert the starch source into a sugary liquid called wort and to convert the wort into the alcoholic drink known as beer in a fermentation process effected by yeast

The first step, where the wort is prepared by mixing the starch source (normally malted barley) with hot water, is known as "mashing". Hot water (known as "liquor" in brewing terms) is mixed with crushed malt or malts (known as "grist") in a mash tun. The mashing process takes around 1 to 2 hours, during which the starches are converted to sugars, and then the sweet wort is drained off the grains. The grains are now washed in a process known as "sparging". This washing allows the brewer to gather as much of the fermentable liquid from the grains as possible. The process of filtering the spent grain from the wort and sparge water is called wort separation. The traditional process for wort separation is lautering, in which the grain bed itself serves as the filter medium. Some modern breweries prefer the use of filter frames which allow a more finely ground grist.

A 16th-century brewery
 
Most modern breweries use a continuous sparge, collecting the original wort and the sparge water together. However, it is possible to collect a second or even third wash with the not quite spent grains as separate batches. Each run would produce a weaker wort and thus a weaker beer. This process is known as second (and third) runnings. Brewing with several runnings is called parti gyle brewing.

The sweet wort collected from sparging is put into a kettle, or "copper" (so called because these vessels were traditionally made from copper), and boiled, usually for about one hour. During boiling, water in the wort evaporates, but the sugars and other components of the wort remain; this allows more efficient use of the starch sources in the beer. Boiling also destroys any remaining enzymes left over from the mashing stage. Hops are added during boiling as a source of bitterness, flavour and aroma. Hops may be added at more than one point during the boil. The longer the hops are boiled, the more bitterness they contribute, but the less hop flavour and aroma remains in the beer.

After boiling, the hopped wort is now cooled, ready for the yeast. In some breweries, the hopped wort may pass through a hopback, which is a small vat filled with hops, to add aromatic hop flavouring and to act as a filter; but usually the hopped wort is simply cooled for the fermenter, where the yeast is added. During fermentation, the wort becomes beer in a process which requires a week to months depending on the type of yeast and strength of the beer. In addition to producing ethanol, fine particulate matter suspended in the wort settles during fermentation. Once fermentation is complete, the yeast also settles, leaving the beer clear.

During fermentation most of the carbon dioxide is allowed to escape through a trap and the beer is left with carbonation of only about one atmosphere of pressure. The carbonation is often increased either by transferring the beer to a pressure vessel such as a keg and introducing pressurized carbon dioxide, or by transferring it before the fermentation is finished so that carbon dioxide pressure builds up inside the container as the fermentation finishes. Sometimes the beer is put unfiltered (so it still contains yeast) into bottles with some added sugar, which then produces the desired amount of carbon dioxide inside the bottle.

Fermentation is sometimes carried out in two stages, primary and secondary. Once most of the alcohol has been produced during primary fermentation, the beer is transferred to a new vessel and allowed a period of secondary fermentation. Secondary fermentation is used when the beer requires long storage before packaging or greater clarity. When the beer has fermented, it is packaged either into casks for cask ale or kegs, aluminium cans, or bottles for other sorts of beer.

Ingredients

Malted barley before roasting
 
The basic ingredients of beer are water; a starch source, such as malted barley, able to be saccharified (converted to sugars) then fermented (converted into ethanol and carbon dioxide); a brewer's yeast to produce the fermentation; and a flavoring such as hops. A mixture of starch sources may be used, with a secondary starch source, such as maize (corn), rice or sugar, often being termed an adjunct, especially when used as a lower-cost substitute for malted barley. Less widely used starch sources include millet, sorghum and cassava root in Africa, and potato in Brazil, and agave in Mexico, among others. The amount of each starch source in a beer recipe is collectively called the grain bill.

Water is the main ingredient of beer, accounting for 93% of its weight. Though water itself is, ideally, flavorless, its level of dissolved minerals, specifically, bicarbonate ion, does influence beer's finished taste. Due to the mineral properties of each region's water, specific areas were originally the sole producers of certain types of beer, each identifiable by regional characteristics. Regional geology accords that Dublin's hard water is well-suited to making stout, such as Guinness, while the Plzeň Region's soft water is ideal for brewing Pilsner (pale lager), such as Pilsner Urquell. The waters of Burton in England contain gypsum, which benefits making pale ale to such a degree that brewers of pale ales will add gypsum to the local water in a process known as Burtonisation.

The starch source, termed as the "mash ingredients", in a beer provides the fermentable material and is a key determinant of the strength and flavor of the beer. The most common starch source used in beer is malted grain. Grain is malted by soaking it in water, allowing it to begin germination, and then drying the partially germinated grain in a kiln. Malting grain produces enzymes that convert starches in the grain into fermentable sugars. Different roasting times and temperatures are used to produce different colors of malt from the same grain. Darker malts will produce darker beers. Nearly all beer includes barley malt as the majority of the starch. This is because its fibrous hull remains attached to the grain during threshing. After malting, barley is milled, which finally removes the hull, breaking it into large pieces. These pieces remain with the grain during the mash, and act as a filter bed during lautering, when sweet wort is separated from insoluble grain material. Other malted and unmalted grains (including wheat, rice, oats, and rye, and less frequently, corn and sorghum) may be used. Some brewers have produced gluten-free beer, made with sorghum with no barley malt, for those who cannot consume gluten-containing grains like wheat, barley, and rye.

Hop cone in a Hallertau, Germany, hop yard
 
Flavoring beer is the sole major commercial use of hops. The flower of the hop vine is used as a flavouring and preservative agent in nearly all beer made today. The flowers themselves are often called "hops". The first historical mention of the use of hops in beer was from 822 AD in monastery rules written by Adalhard the Elder, also known as Adalard of Corbie, though the date normally given for widespread cultivation of hops for use in beer is the thirteenth century. Before the thirteenth century, and until the sixteenth century, during which hops took over as the dominant flavoring, beer was flavored with other plants; for instance, grains of paradise or alehoof. Combinations of various aromatic herbs, berries, and even ingredients like wormwood would be combined into a mixture known as gruit and used as hops are now used. Some beers today, such as Fraoch' by the Scottish Heather Ales company and Cervoise Lancelot by the French Brasserie-Lancelot company, use plants other than hops for flavoring. 

Hops contain several characteristics that brewers desire in beer. Hops contribute a bitterness that balances the sweetness of the malt; the bitterness of beers is measured on the International Bitterness Units scale. Hops contribute floral, citrus, and herbal aromas and flavors to beer. Hops have an antibiotic effect that favors the activity of brewer's yeast over less desirable microorganisms and aids in "head retention", the length of time that a foamy head created by carbonation will last. The acidity of hops is a preservative.

Yeast is the microorganism that is responsible for fermentation in beer. Yeast metabolizes the sugars extracted from grains, which produces alcohol and carbon dioxide, and thereby turns wort into beer. In addition to fermenting the beer, yeast influences the character and flavor. The dominant types of yeast used to make beer are the top-fermenting Saccharomyces cerevisiae and bottom-fermenting Saccharomyces pastorianus. Brettanomyces ferments lambics, and Torulaspora delbrueckii ferments Bavarian weissbier. Before the role of yeast in fermentation was understood, fermentation involved wild or airborne yeasts. A few styles such as lambics rely on this method today, but most modern fermentation adds pure yeast cultures.

Some brewers add one or more clarifying agents or finings to beer, which typically precipitate (collect as a solid) out of the beer along with protein solids and are found only in trace amounts in the finished product. This process makes the beer appear bright and clean, rather than the cloudy appearance of ethnic and older styles of beer such as wheat beers. Examples of clarifying agents include isinglass, obtained from swimbladders of fish; Irish moss, a seaweed; kappa carrageenan, from the seaweed Kappaphycus cottonii; Polyclar (artificial); and gelatin. If a beer is marked "suitable for vegans", it was clarified either with seaweed or with artificial agents.

Brewing industry

Annual beer consumption per capita by country
 
Beer Exports by Country (2014) from Harvard Atlas of Economic Complexity
 
The history of breweries in the 21st century has been one of larger breweries absorbing smaller breweries in order to ensure economy of scale. In 2002 South African Breweries bought the North American Miller Brewing Company to found SABMiller, becoming the second largest brewery, after North American Anheuser-Bush. In 2004 the Belgian Interbrew was the third largest brewery by volume and the Brazilian AmBev was the fifth largest. They merged into InBev, becoming the largest brewery. In 2007, SABMiller surpassed InBev and Anheuser-Bush when it acquired Royal Grolsch, brewer of Dutch premium beer brand Grolsch in 2007. In 2008, when InBev (the second-largest) bought Anheuser-Busch (the third largest), the new Anheuser-Busch InBev company became again the largest brewer in the world. As of 2015 AB InBev remains the largest brewery, with SABMiller second, and Heineken International third.

A microbrewery, or craft brewery, produces a limited amount of beer. The maximum amount of beer a brewery can produce and still be classed as a microbrewery varies by region and by authority, though is usually around 15,000 barrels (1.8 megalitres, 396 thousand imperial gallons or 475 thousand US gallons) a year. A brewpub is a type of microbrewery that incorporates a pub or other drinking establishment. The highest density of breweries in the world, most of them microbreweries, exists in the German Region of Franconia, especially in the district of Upper Franconia, which has about 200 breweries. The Benedictine Weihenstephan brewery in Bavaria, Germany, can trace its roots to the year 768, as a document from that year refers to a hop garden in the area paying a tithe to the monastery. The brewery was licensed by the City of Freising in 1040, and therefore is the oldest working brewery in the world.

Brewing at home is subject to regulation and prohibition in many countries. Restrictions on homebrewing were lifted in the UK in 1963, Australia followed suit in 1972, and the US in 1978, though individual states were allowed to pass their own laws limiting production.

Etymology

An Old English word for beer
 
The word ale comes from Old English ealu (plural ealoþ), in turn from Proto-Germanic *alu (plural *aluþ), ultimately from the Proto-Indo-European base *h₂elut-, which holds connotations of "sorcery, magic, possession, intoxication". The word beer comes from Old English bēor, from Proto-Germanic *beuzą, probably from Proto-Indo-European *bʰeusóm, originally "brewer's yeast, beer dregs", although other theories have been provided connecting the word with Old English bēow, "barley", or Latin bibere, "to drink". On the currency of two words for the same thing in the Germanic languages, the 12th-century Old Icelandic poem Alvíssmál says, "Ale it is called among men, but among the gods, beer."

Varieties

Cask ale hand pumps with pump clips detailing the beers and their breweries
 
While there are many types of beer brewed, the basics of brewing beer are shared across national and cultural boundaries. The traditional European brewing regions—Germany, Belgium, England and the Czech Republic—have local varieties of beer.

English writer Michael Jackson, in his 1977 book The World Guide To Beer, categorized beers from around the world in local style groups suggested by local customs and names. Fred Eckhardt furthered Jackson's work in The Essentials of Beer Style in 1989. 

Top-fermented beers are most commonly produced with Saccharomyces cerevisiae, a top-fermenting yeast which clumps and rises to the surface, typically between 15 and 25 °C (59 and 77 °F). At these temperatures, yeast produces significant amounts of esters and other secondary flavor and aroma products, and the result is often a beer with slightly "fruity" compounds resembling apple, pear, pineapple, banana, plum, or prune, among others.

After the introduction of hops into England from Flanders in the 15th century, "ale" referred to an unhopped fermented drink, "beer" being used to describe a brew with an infusion of hops.

Real ale is the term coined by the Campaign for Real Ale (CAMRA) in 1973 for "beer brewed from traditional ingredients, matured by secondary fermentation in the container from which it is dispensed, and served without the use of extraneous carbon dioxide". It is applied to bottle conditioned and cask conditioned beers. 

Pale ale is a beer which uses a top-fermenting yeast and predominantly pale malt. It is one of the world's major beer styles. 

Stout and porter are dark beers made using roasted malts or roast barley, and typically brewed with slow fermenting yeast. There are a number of variations including Baltic porter, dry stout, and Imperial stout. The name "porter" was first used in 1721 to describe a dark brown beer popular with the street and river porters of London. This same beer later also became known as stout, though the word stout had been used as early as 1677. The history and development of stout and porter are intertwined.

Mild ale has a predominantly malty palate. It is usually dark coloured with an abv of 3% to 3.6%, although there are lighter hued milds as well as stronger examples reaching 6% abv and higher.

Wheat beer is brewed with a large proportion of wheat although it often also contains a significant proportion of malted barley. Wheat beers are usually top-fermented. The flavour of wheat beers varies considerably, depending upon the specific style. 

Kriek, a variety of beer brewed with cherries
 
Lambic, a beer of Belgium, is naturally fermented using wild yeasts, rather than cultivated. Many of these are not strains of brewer's yeast (Saccharomyces cerevisiae) and may have significant differences in aroma and sourness. Yeast varieties such as Brettanomyces bruxellensis and Brettanomyces lambicus are common in lambics. In addition, other organisms such as Lactobacillus bacteria produce acids which contribute to the sourness.

A marzen style lager
 
Lager is cool fermented beer. Pale lagers are the most commonly consumed beers in the world. Many are of the “pilsner” type. The name "lager" comes from the German "lagern" for "to store", as brewers around Bavaria stored beer in cool cellars and caves during the warm summer months. These brewers noticed that the beers continued to ferment, and to also clear of sediment, when stored in cool conditions.

Lager yeast is a cool bottom-fermenting yeast (Saccharomyces pastorianus) and typically undergoes primary fermentation at 7–12 °C (45–54 °F) (the fermentation phase), and then is given a long secondary fermentation at 0–4 °C (32–39 °F) (the lagering phase). During the secondary stage, the lager clears and mellows. The cooler conditions also inhibit the natural production of esters and other byproducts, resulting in a "cleaner"-tasting beer.

With improved modern yeast strains, most lager breweries use only short periods of cold storage, typically 1–3 weeks.

Measurement

Beer is measured and assessed by bitterness, by strength and by color. The perceived bitterness is measured by the International Bitterness Units scale (IBU), defined in co-operation between the American Society of Brewing Chemists and the European Brewery Convention. The international scale was a development of the European Bitterness Units scale, often abbreviated as EBU, and the bitterness values should be identical.

Color

Paulaner dunkel – a dark lager
 
Beer color is determined by the malt. The most common color is a pale amber produced from using pale malts. Pale lager and pale ale are terms used for beers made from malt dried with the fuel coke. Coke was first used for roasting malt in 1642, but it was not until around 1703 that the term pale ale was used.

In terms of sales volume, most of today's beer is based on the pale lager brewed in 1842 in the town of Pilsen in the present-day Czech Republic. The modern pale lager is light in color with a noticeable carbonation (fizzy bubbles) and a typical alcohol by volume content of around 5%. The Pilsner Urquell, Bitburger, and Heineken brands of beer are typical examples of pale lager, as are the American brands Budweiser, Coors, and Miller.

Dark beers are usually brewed from a pale malt or lager malt base with a small proportion of darker malt added to achieve the desired shade. Other colorants—such as caramel—are also widely used to darken beers. Very dark beers, such as stout, use dark or patent malts that have been roasted longer. Some have roasted unmalted barley.

Strength

Beer ranges from less than 3% alcohol by volume (abv) to around 14% abv, though this strength can be increased to around 20% by re-pitching with champagne yeast, and to 55% abv by the freeze-distilling process. The alcohol content of beer varies by local practice or beer style. The pale lagers that most consumers are familiar with fall in the range of 4–6%, with a typical abv of 5%. The customary strength of British ales is quite low, with many session beers being around 4% abv. Some beers, such as table beer are of such low alcohol content (1%–4%) that they are served instead of soft drinks in some schools.

The alcohol in beer comes primarily from the metabolism of sugars that are produced during fermentation. The quantity of fermentable sugars in the wort and the variety of yeast used to ferment the wort are the primary factors that determine the amount of alcohol in the final beer. Additional fermentable sugars are sometimes added to increase alcohol content, and enzymes are often added to the wort for certain styles of beer (primarily "light" beers) to convert more complex carbohydrates (starches) to fermentable sugars. Alcohol is a by-product of yeast metabolism and is toxic to the yeast in higher concentrations; typical brewing yeast cannot survive at alcohol concentrations above 12% by volume. Low temperatures and too little fermentation time decreases the effectiveness of yeasts and consequently decreases the alcohol content.

The weakest beers are dealcoholized beers, which typically have less than 0.05% alcohol (also called "near beer") and light beers, which usually have 4% alcohol. 

The strength of beers has climbed during the later years of the 20th century. Vetter 33, a 10.5% abv (33 degrees Plato, hence Vetter "33") doppelbock, was listed in the 1994 Guinness Book of World Records as the strongest beer at that time, though Samichlaus, by the Swiss brewer Hürlimann, had also been listed by the Guinness Book of World Records as the strongest at 14% abv. Since then, some brewers have used champagne yeasts to increase the alcohol content of their beers. Samuel Adams reached 20% abv with Millennium, and then surpassed that amount to 25.6% abv with Utopias. The strongest beer brewed in Britain was Baz's Super Brew by Parish Brewery, a 23% abv beer. In September 2011, the Scottish brewery BrewDog produced Ghost Deer, which, at 28%, they claim to be the world's strongest beer produced by fermentation alone.

The product claimed to be the strongest beer made is Schorschbräu's 2011 Schorschbock 57 with 57,5%. It was preceded by The End of History, a 55% Belgian ale, made by BrewDog in 2010. The same company had previously made Sink The Bismarck!, a 41% abv IPA, and Tactical Nuclear Penguin, a 32% abv Imperial stout. Each of these beers are made using the eisbock method of fractional freezing, in which a strong ale is partially frozen and the ice is repeatedly removed, until the desired strength is reached, a process that may class the product as spirits rather than beer. The German brewery Schorschbräu's Schorschbock, a 31% abv eisbock, and Hair of the Dog's Dave, a 29% abv barley wine made in 1994, used the same fractional freezing method. A 60% abv blend of beer with whiskey was jokingly claimed as the strongest beer by a Dutch brewery in July 2010.

Serving

Draught

A selection of cask beers
 
Draught (also spelled "draft") beer from a pressurized keg using a lever-style dispenser and a spout is the most common method of dispensing in bars around the world. A metal keg is pressurized with carbon dioxide (CO2) gas which drives the beer to the dispensing tap or faucet. Some beers may be served with a nitrogen/carbon dioxide mixture. Nitrogen produces fine bubbles, resulting in a dense head and a creamy mouthfeel. Some types of beer can also be found in smaller, disposable kegs called beer balls. In traditional pubs, the pull levers for major beer brands may include the beer's logo and trademark. 

In the 1980s, Guinness introduced the beer widget, a nitrogen-pressurized ball inside a can which creates a dense, tight head, similar to beer served from a nitrogen system. The words draft and draught can be used as marketing terms to describe canned or bottled beers containing a beer widget, or which are cold-filtered rather than pasteurized. 

Cask-conditioned ales (or cask ales) are unfiltered and unpasteurized beers. These beers are termed "real ale" by the CAMRA organization. Typically, when a cask arrives in a pub, it is placed horizontally on a frame called a "stillage" which is designed to hold it steady and at the right angle, and then allowed to cool to cellar temperature (typically between 11–13 °C or 52–55 °F), before being tapped and vented—a tap is driven through a (usually rubber) bung at the bottom of one end, and a hard spile or other implement is used to open a hole in the side of the cask, which is now uppermost. The act of stillaging and then venting a beer in this manner typically disturbs all the sediment, so it must be left for a suitable period to "drop" (clear) again, as well as to fully condition — this period can take anywhere from several hours to several days. At this point the beer is ready to sell, either being pulled through a beer line with a hand pump, or simply being "gravity-fed" directly into the glass. 

Draught beer's environmental impact can be 68% lower than bottled beer due to packaging differences. A life cycle study of one beer brand, including grain production, brewing, bottling, distribution and waste management, shows that the CO2 emissions from a 6-pack of micro-brew beer is about 3 kilograms (6.6 pounds). The loss of natural habitat potential from the 6-pack of micro-brew beer is estimated to be 2.5 square meters (26 square feet). Downstream emissions from distribution, retail, storage and disposal of waste can be over 45% of a bottled micro-brew beer's CO2 emissions. Where legal, the use of a refillable jug, reusable bottle or other reusable containers to transport draught beer from a store or a bar, rather than buying pre-bottled beer, can reduce the environmental impact of beer consumption.

Packaging

Assortment of beer bottles
 
Most beers are cleared of yeast by filtering when packaged in bottles and cans. However, bottle conditioned beers retain some yeast—either by being unfiltered, or by being filtered and then reseeded with fresh yeast. It is usually recommended that the beer be poured slowly, leaving any yeast sediment at the bottom of the bottle. However, some drinkers prefer to pour in the yeast; this practice is customary with wheat beers. Typically, when serving a hefeweizen wheat beer, 90% of the contents are poured, and the remainder is swirled to suspend the sediment before pouring it into the glass. Alternatively, the bottle may be inverted prior to opening. Glass bottles are always used for bottle conditioned beers. 

Many beers are sold in cans, though there is considerable variation in the proportion between different countries. In Sweden in 2001, 63.9% of beer was sold in cans. People either drink from the can or pour the beer into a glass. A technology developed by Crown Holdings for the 2010 FIFA World Cup is the 'full aperture' can, so named because the entire lid is removed during the opening process, turning the can into a drinking cup. Cans protect the beer from light (thereby preventing "skunked" beer) and have a seal less prone to leaking over time than bottles. Cans were initially viewed as a technological breakthrough for maintaining the quality of a beer, then became commonly associated with less expensive, mass-produced beers, even though the quality of storage in cans is much like bottles. Plastic (PET) bottles are used by some breweries.

Temperature

The temperature of a beer has an influence on a drinker's experience; warmer temperatures reveal the range of flavours in a beer but cooler temperatures are more refreshing. Most drinkers prefer pale lager to be served chilled, a low- or medium-strength pale ale to be served cool, while a strong barley wine or imperial stout to be served at room temperature.

Beer writer Michael Jackson proposed a five-level scale for serving temperatures: well chilled (7 °C or 45 °F) for "light" beers (pale lagers); chilled (8 °C or 46 °F) for Berliner Weisse and other wheat beers; lightly chilled (9 °C or 48 °F) for all dark lagers, altbier and German wheat beers; cellar temperature (13 °C or 55 °F) for regular British ale, stout and most Belgian specialities; and room temperature (15.5 °C or 60 °F for strong dark ales (especially trappist beer) and barley wine.

Drinking chilled beer began with the development of artificial refrigeration and by the 1870s, was spread in those countries that concentrated on brewing pale lager. Chilling beer makes it more refreshing, though below 15.5 °C (60 °F) the chilling starts to reduce taste awareness and reduces it significantly below 10 °C (50 °F). Beer served unchilled—either cool or at room temperature—reveal more of their flavours. Cask Marque, a non-profit UK beer organization, has set a temperature standard range of 12°–14 °C (53°–57 °F) for cask ales to be served.

Vessels

Beer is consumed out of a variety of vessels, such as a glass, a beer stein, a mug, a pewter tankard, a beer bottle or a can; or at music festivals and some bars and nightclubs, from a plastic cup. The shape of the glass from which beer is consumed can influence the perception of the beer and can define and accent the character of the style. Breweries offer branded glassware intended only for their own beers as a marketing promotion, as this increases sales of their product.

The pouring process has an influence on a beer's presentation. The rate of flow from the tap or other serving vessel, tilt of the glass, and position of the pour (in the center or down the side) into the glass all influence the end result, such as the size and longevity of the head, lacing (the pattern left by the head as it moves down the glass as the beer is drunk), and the release of carbonation. A beer tower is a beer dispensing device, usually found in bars and pubs, that consists of a cylinder attached to a beer cooling device at the bottom. Beer is dispensed from the beer tower into a drinking vessel.

Health effects

Beer contains ethanol, an alcohol, which has short and long-term effects on the user when consumed. Different concentrations of alcohol in the human body have different effects on a person. The effects of alcohol depend on the amount an individual has drunk, the percentage of alcohol in the beer and the time span over which the consumption has taken place, the amount of food eaten and whether an individual has taken other prescription, over-the-counter or street drugs, among other factors. Drinking enough to cause a blood alcohol concentration (BAC) of 0.03%–0.12% typically causes an overall improvement in mood and possible euphoria, increased self-confidence and sociability, decreased anxiety, a flushed, red appearance in the face and impaired judgement and fine muscle coordination. A BAC of 0.09% to 0.25% causes lethargy, sedation, balance problems and blurred vision. A BAC from 0.18% to 0.30% causes profound confusion, impaired speech (e.g., slurred speech), staggering, dizziness and vomiting. A BAC from 0.25% to 0.40% causes stupor, unconsciousness, anterograde amnesia, vomiting (death may occur due to inhalation of vomit (pulmonary aspiration) while unconscious) and respiratory depression (potentially life-threatening). A BAC from 0.35% to 0.80% causes a coma (unconsciousness), life-threatening respiratory depression and possibly fatal alcohol poisoning. As with all alcoholic drinks, drinking while driving, operating an aircraft or heavy machinery increases the risk of an accident; many countries have severe criminal penalties against drunk driving. 

A 2016 systematic review and meta-analysis found that moderate ethanol consumption brought no mortality benefit compared with lifetime abstention from ethanol consumption. Some studies have concluded that drinking small quantities of alcohol (less than one drink in women and two in men) is associated with a decreased risk of heart disease, stroke, diabetes mellitus, and early death. Some of these studies combined former ethanol drinkers and life-long abstainers into a single group of nondrinkers, which hides the health benefits of life-long abstention from ethanol. The long term health effects of continuous, moderate or heavy alcohol consumption include the risk of developing alcoholism and alcoholic liver disease. Alcoholism, also known as "alcohol use disorder", is a broad term for any drinking of alcohol that results in problems. It was previously divided into two types: alcohol abuse and alcohol dependence. In a medical context, alcoholism is said to exist when two or more of the following conditions is present: a person drinks large amounts over a long time period, has difficulty cutting down, acquiring and drinking alcohol takes up a great deal of time, alcohol is strongly desired, usage results in not fulfilling responsibilities, usage results in social problems, usage results in health problems, usage results in risky situations, withdrawal occurs when stopping, and alcohol tolerance has occurred with use. Alcoholism reduces a person's life expectancy by around ten years and alcohol use is the third leading cause of early death in the United States. No professional medical association recommends that people who are nondrinkers should start drinking wine. A total of 3.3 million deaths (5.9% of all deaths) are believed to be due to alcohol.

It is considered that overeating and lack of muscle tone is the main cause of a beer belly, rather than beer consumption. A 2004 study, however, found a link between binge drinking and a beer belly. But with most overconsumption, it is more a problem of improper exercise and over consumption of carbohydrates than the product itself. Several diet books quote beer as having an undesirably high glycemic index of 110, the same as maltose; however, the maltose in beer undergoes metabolism by yeast during fermentation so that beer consists mostly of water, hop oils and only trace amounts of sugars, including maltose.

Nutritional information

Beers vary in their nutritional content. The ingredients used to make beer, including the yeast, provide a rich source of nutrients; therefore beer may contain nutrients including magnesium, selenium, potassium, phosphorus, biotin, chromium and B vitamins. Beer is sometimes referred to as "liquid bread", though beer is not a meal in itself.

NUTRITION INFORMATION OF DIFFERENT BEERS (SERVING SIZE 12 OZ./355ml)
 Beer Brand   Carbs (g)   Alcohol   Calories 
 Budweiser Select 55   1.8  2.4%  55
 Coors Light   5  4.2%  102
 Guinness Draught   10  4%  126
 Sierra Nevada Bigfoot   30.3  9.6%  330

Society and culture

A tent at Munich's Oktoberfest—the world's largest beer festival
 
In many societies, beer is the most popular alcoholic drink. Various social traditions and activities are associated with beer drinking, such as playing cards, darts, or other pub games; attending beer festivals; engaging in zythology (the study of beer); visiting a series of pubs in one evening; visiting breweries; beer-oriented tourism; or rating beer. Drinking games, such as beer pong, are also popular. A relatively new profession is that of the beer sommelier, who informs restaurant patrons about beers and food pairings. 

Beer is considered to be a social lubricant in many societies and is consumed in countries all over the world. There are breweries in Middle Eastern countries such as Syria, and in some African countries. Sales of beer are four times those of wine, which is the second most popular alcoholic drink.

A study published in the Neuropsychopharmacology journal in 2013 revealed the finding that the flavour of beer alone could provoke dopamine activity in the brain of the male participants, who wanted to drink more as a result. The 49 men in the study were subject to positron emission tomography scans, while a computer-controlled device sprayed minute amounts of beer, water and a sports drink onto their tongues. Compared with the taste of the sports drink, the taste of beer significantly increased the participants desire to drink. Test results indicated that the flavor of the beer triggered a dopamine release, even though alcohol content in the spray was insufficient for the purpose of becoming intoxicated.

Some breweries have developed beers to pair with food. Wine writer Malcolm Gluck disputed the need to pair beer with food, while beer writers Roger Protz and Melissa Cole contested that claim.

Related drinks

Around the world, there are many traditional and ancient starch-based drinks classed as beer. In Africa, there are various ethnic beers made from sorghum or millet, such as Oshikundu in Namibia and Tella in Ethiopia. Kyrgyzstan also has a beer made from millet; it is a low alcohol, somewhat porridge-like drink called "Bozo". Bhutan, Nepal, Tibet and Sikkim also use millet in Chhaang, a popular semi-fermented rice/millet drink in the eastern Himalayas. Further east in China are found Huangjiu and Choujiu—traditional rice-based drinks related to beer. 

The Andes in South America has Chicha, made from germinated maize (corn); while the indigenous peoples in Brazil have Cauim, a traditional drink made since pre-Columbian times by chewing manioc so that an enzyme (amylase) present in human saliva can break down the starch into fermentable sugars; this is similar to Masato in Peru.

Some beers which are made from bread, which is linked to the earliest forms of beer, are Sahti in Finland, Kvass in Russia and Ukraine, and Bouza in Sudan.

Chemistry

Beer contains the phenolic acids 4-hydroxyphenylacetic acid, vanillic acid, caffeic acid, syringic acid, p-coumaric acid, ferulic acid, and sinapic acid. Alkaline hydrolysis experiments show that most of the phenolic acids are present as bound forms and only a small portion can be detected as free compounds. Hops, and beer made with it, contain 8-prenylnaringenin which is a potent phytoestrogen. Hop also contains myrcene, humulene, xanthohumol, isoxanthohumol, myrcenol, linalool, tannins, and resin. The alcohol 2M2B is a component of hops brewing.

Barley, in the form of malt, brings the condensed tannins prodelphinidins B3, B9 and C2 into beer. Tryptophol, tyrosol, and phenylethanol are aromatic higher alcohols found in beer as secondary products of alcoholic fermentation (products also known as congeners) by Saccharomyces cerevisiae.

Biosafety

From Wikipedia, the free encyclopedia

Biosafety is the prevention of large-scale loss of biological integrity, focusing both on ecology and human health. These prevention mechanisms include conduction of regular reviews of the biosafety in laboratory settings, as well as strict guidelines to follow. Biosafety is used to protect from harmful incidents. Many laboratories handling biohazards employ an ongoing risk management assessment and enforcement process for biosafety. Failures to follow such protocols can lead to increased risk of exposure to biohazards or pathogens. Human error and poor technique contribute to unnecessary exposure and compromise the best safeguards set into place for protection.

Positive-pressure biosafety suit
 
The international Cartagena Protocol on Biosafety deals primarily with the agricultural definition but many advocacy groups seek to expand it to include post-genetic threats: new molecules, artificial life forms, and even robots which may compete directly in the natural food chain. 

Biosafety in agriculture, chemistry, medicine, exobiology and beyond will likely require the application of the precautionary principle, and a new definition focused on the biological nature of the threatened organism rather than the nature of the threat. 

When biological warfare or new, currently hypothetical, threats (i.e., robots, new artificial bacteria) are considered, biosafety precautions are generally not sufficient. (link to incident report, i.e. such as problems with CDC research labs in 2014)The new field of biosecurity addresses these complex threats. 

Biosafety level refers to the stringency of biocontainment precautions deemed necessary by the Centers for Disease Control and Prevention (CDC) for laboratory work with infectious materials. 

Typically, institutions that experiment with or create potentially harmful biological material will have a committee or board of supervisors that is in charge of the institution's biosafety. They create and monitor the biosafety standards that must be met by labs in order to prevent the accidental release of potentially destructive biological material. (note that in the US, several groups are involved, and efforts are being made to improve processes for government run labs, but there is no unifying regulatory authority for all labs. 

Biosafety is related to several fields:

In synthetic biology

A complete understanding of experimental risks associated with synthetic biology is helping to enforce the knowledge and effectiveness of biosafety. With the potential future creation of man-made unicellular organisms, some are beginning to consider the effect that these organisms will have on biomass already present. Scientists estimate that within the next few decades, organism design will be sophisticated enough to accomplish tasks such as creating biofuels and lowering the levels of harmful substances in the atmosphere. Scientist that favor the development of synthetic biology claim that the use of biosafety mechanisms such as suicide genes and nutrient dependencies will ensure the organisms cannot survive outside of the lab setting in which they were originally created. Organizations like the ETC Group argue that regulations should control the creation of organisms that could potentially harm existing life. They also argue that the development of these organisms will simply shift the consumption of petroleum to the utilization of biomass in order to create energy. These organisms can harm existing life by affecting the prey/predator food chain, reproduction between species, as well as competition against other species (species at risk, or act as an invasive species). Synthetic vaccines are now being produced in the lab. These have caused a lot of excitement in the pharmaceutical industry as they will be cheaper to produce, allow quicker production, as well enhance the knowledge of virology and immunology.

In medicine, healthcare settings and laboratories

Biosafety, in medicine and health care settings, specifically refers to proper handling of organs or tissues from biological origin, or genetic therapy products, viruses with respect to the environment, to ensure the safety of health care workers, researchers, lab staff, patients, and the general public. Laboratories are assigned a biosafety level numbered 1 through 4 based on their potential biohazard risk level. The employing authority, through the laboratory director, is responsible for ensuring that there is adequate surveillance of the health of laboratory personnel. The objective of such surveillance is to monitor for occupationally acquired diseases. The World Health Organization attributes human error and poor technique as the primary cause of mishandling of biohazardous materials. 

Biosafety is also becoming a global concern and requires multilevel resources and international collaboration to monitor, prevent and correct accidents from unintended and malicious release and also to prevent that bioterrorists get their hands-on biologics sample to create biologic weapons of mass destruction. Even people outside of the health sector needs to be involved as in the case of the Ebola outbreak the impact that it had on businesses and travel required that private sectors, international banks together pledged more than $2 billion to combat the epidemic. The bureau of international Security and nonproliferation (ISN) is responsible for managing a broad range of U.S. nonproliferation policies, programs, agreements, and initiatives, and biological weapon is one their concerns Biosafety has its risks and benefits. All stakeholders must try to find a balance between cost-effectiveness of safety measures and use evidence-based safety practices and recommendations, measure the outcomes and consistently reevaluate the potential benefits that biosafety represents for human health. Biosafety level designations are based on a composite of the design features, construction, containment facilities, equipment, practices and operational procedures required for working with agents from the various risk groups.

Classification of biohazardous materials is subjective and the risk assessment is determined by the individuals most familiar with the specific characteristics of the organism. There are several factors taken into account when assessing an organism and the classification process.
  1. Risk Group 1: (no or low individual and community risk) A microorganism that is unlikely to cause human or animal disease.
  2. Risk Group 2 : (moderate individual risk, low community risk) A pathogen that can cause human or animal disease but is unlikely to be a serious hazard to laboratory workers, the community, livestock or the environment. Laboratory exposures may cause serious infection, but effective treatment and preventive measures are available and the risk of spread of infection is limited.
  3. Risk Group 3 : (high individual risk, low community risk) A pathogen that usually causes serious human or animal disease but does not ordinarily spread from one infected individual to another. Effective treatment and preventive measures are available.
  4. Risk Group 4 : (high individual and community risk) A pathogen that usually causes serious human or animal disease and that can be readily transmitted from one individual to another, directly or indirectly. Effective treatment and preventive measures are not usually available.
Investigations have shown that there are hundreds of unreported biosafety accidents, with laboratories self-policing the handling of biohazardous materials and lack of reporting. Poor record keeping, improper disposal, and mishandling biohazardous materials result in increased risks of biochemical contamination for both the public and environment.

Along with the precautions taken during the handling process of biohazardous materials, the World Health Organization recommends: Staff training should always include information on safe methods for highly hazardous procedures that are commonly encountered by all laboratory personnel and which involve:
  • Inhalation risks (i.e. aerosol production) when using loops, streaking agar plates,
  • pipetting, making smears, opening cultures, taking blood/serum samples, centrifuging, etc.
  • Ingestion risks when handling specimens, smears and cultures
  • Risks of percutaneous exposures when using syringes and needles
  • Bites and scratches when handling animals
  • Handling of blood and other potentially hazardous pathological materials
  • Decontamination and disposal of infectious material.

Policy and practice in the United States

Legal information

In June 2009, the Trans-Federal Task Force On Optimizing Biosafety and Biocontainment Oversight recommended the formation of an agency to coordinate high safety risk level labs (3 and 4), and voluntary, non-punitive measures for incident reporting. However, it is unclear as to what changes may or may not have been implemented following their recommendations.

United States Code of Federal Regulations

The United States Code of Federal Regulations is the codification (law), or collection of laws specific to a specific to a jurisdiction that represent broad areas subject to federal regulation. Title 42 of the Code of Federal Regulations addresses laws concerning Public Health issues including biosafety which can be found under the citation 42 CFR 73 to 42 CFR 73.21 by accessing the US Code of Federal Regulations (CFR) website.

International Biohazard Warning Symbol

Title 42 Section 73 of the CFR addresses specific aspects of biosafety including Occupational safety and health, transportation of biohazardous materials and safety plans for laboratories using potential biohazards. While biocontainment, as defined in the Biosafety in Microbiological and Biomedical Laboratories and Primary Containment for Biohazards: Selection, Installation and Use of Biosafety Cabinets manuals available at the Centers for Disease Control and Prevention website much of the design, implementation and monitoring of protocols are left up to state and local authorities.

The United States CFR states "An individual or entity required to register [as a user of biological agents] must develop and implement a written biosafety plan that is commensurate with the risk of the select agent or toxin" which is followed by 3 recommended sources for laboratory reference.
  1. The CDC/NIH publication, "Biosafety in Microbiological and Biomedical Laboratories."
  2. The Occupational Safety and Health Administration (OSHA) regulations in 29 CFR parts 1910.1200 and 1910.1450.
  3. The "NIH Guidelines for Research Involving Recombinant DNA Molecules," (NIH Guidelines).
While clearly the needs of biocontainment and biosafety measures vary across government, academic and private industry laboratories, biological agents pose similar risks independent of their locale. Laws relating to biosafety are not easily accessible and there are few federal regulations that are readily available for a potential trainee to reference outside of the publications recommended in 42 CFR 73.12. Therefore, training is the responsibility of lab employers and is not consistent across various laboratory types thereby increasing the risk of accidental release of biological hazards that pose serious health threats to the humans, animals and the ecosystem as a whole.

Agency guidance

Many government agencies have made guidelines and recommendations in an effort to increase biosafety measures across laboratories in the United States. Agencies involved in producing policies surrounding biosafety within a hospital, pharmacy or clinical research laboratory include: the CDC, FDA, USDA, DHHS, DoT, EPA and potentially other local organizations including public health departments. The federal government does set some standards and recommendations for States to meet their standards, most of which fall under the Occupational Safety and Health Act of 1970, but currently, there is no single federal regulating agency directly responsible for ensuring the safety of biohazardous handling, storage, identification, clean-up and disposal. In addition to the CDC, the Environmental Protection Agency has some of the most accessible information on ecological impacts of biohazards, how to handle spills, reporting guidelines and proper disposal of agents dangerous to the environment. Many of these agencies have their own manuals and guidance documents relating to training and certain aspects of biosafety directly tied to their agency's scope, including transportation, storage and handling of blood borne pathogens. (OSHA, IATA). The American Biological Safety Association (ABSA) has a list of such agencies and links to their websites, along with links to publications and guidance documents to assist in risk assessment, lab design and adherence to laboratory exposure control plans. Many of these agencies were members of the 2009 Task Force on BioSafety. There was also a formation of a Blue Ribbon Study Panel on Biodefense, but this is more concernend with national defense programs and biosecurity.

Ultimately states and local governments, as well as private industry labs, are left to make the final determinants for their own biosafety programs, which vary widely in scope and enforcement across the United States. Not all state programs address biosafety from all necessary perspectives, which should not just include personal safety, but also emphasize an full understanding among laboratory personnel of quality control and assurance, exposure potential impacts on the environment, and general public safety.

State occupational safety plans are often focused on transportation, disposal, and risk assessment, allowing caveats for safety audits, but ultimately leaves the training in the hands of the employer. 22 states have approved Occupational Safety plans by OSHA that are audited annually for effectiveness. These plans apply to private and public sector workers, and not necessarily state/ government workers, and not all specifically have a comprehensive program for all aspects of biohazard management from start to finish. Sometimes biohazard management plans are limited only to workers in transportation specific job titles. The enforcement and training on such regulations can vary from lab to lab based on the State's plans for occupational health and safety. With the exception of DoD lab personnel, CDC lab personnel, First responders, and DoT employees, enforcement of training is inconsistent, and while training is required to be done, specifics on the breadth and frequency of refresher training does not seem consistent from state to state; penalties may never be assessed without larger regulating bodies being aware of non-compliance, and enforcement is limited.

Medical waste management in the United States

Medical waste management was identified as an issue in the 1980s; with the Medical Waste Tracking Act of 1988 becoming the new standard in biohazard waste disposal.

Although the Federal Government, EPA & DOT provide some oversight of regulated medical waste storage, transportation, and disposal the majority of biohazard medical waste is regulated at the state level. Each state is responsible for regulation and management of their own bioharzardous waste with each state varying in their regulatory process. Record keeping of biohazardous waste also varies between states.

Medical healthcare centers, hospitals veterinary clinics, clinical laboratories and other facilities generate over one million tons of waste each year. Although the majority of this waste is as harmless as common household waste, as much as 15 percent of this waste poses a potential infection hazard, according to the Environmental Protection Agency (EPA). Medical waste is required to be rendered non-infectious before it can be disposed of. There are several different methods to treat and dispose of biohazardous waste. In the United States, the primary methods for treatment and disposal of biohazard, medical and sharps waste may include:
Different forms of biohazardous wasted required different treatments for their proper waste management. This is determined largely be each states regulations. Currently, there are several contracted companies that focus on medical, sharps and biological hazard disposal. Stericycle is one of the leaders in medical waste and pharmaceutical disposal in the United States.

Incidents of non-compliance and reform efforts

The United States Government has made it clear that biosafety is to be taken very seriously. In 2014, incidents with Anthrax and Ebola pathogens in CDC laboratories, prompted the CDC director Tom Frieden to issue a moratorium for research with these types of select agents. An investigation concluded that there was a lack of adherence to safety protocols and "inadequate safeguards" in place. This indicated a lack of proper training or reinforcement of training and supervision on regular basis for lab personnel. 

Following these incidents, the CDC established an External Laboratory Safety Workgroup (ELSW), and suggestions have been made to reform effectiveness of the Federal Select Agent Program. The White house issued a report on national biosafety priorities in 2015, outlining next steps for a national biosafety and security program, and addressed biological safety needs for health research, national defense, and public safety.

In 2016, the Association of Public Health Laboratories (APHL) had a presentation at their annual meeting focused on improving biosafety culture. This same year, The UPMC Center for Health Security issued a case study report including reviews of ten different nations' current biosafety regulations, including the United States. Their goal was to "provide a foundation for identifying national‐level biosafety norms and enable initial assessment of biosafety priorities necessary for developing effective national biosafety regulation and oversight."

For Museums, Augmented Reality Is the Next Frontier

Microsoft
Mae Jemison, the first woman of color to go into space, stood in the center of the room and prepared to become digital. Around her, 106 cameras captured her image in 3-D, which would later render her as a life-sized hologram when viewed through a HoloLens headset.

Jemison was recording what would become the introduction for a new exhibit at the Intrepid Sea, Air, and Space Museum, which opens tomorrow as part of the Smithsonian’s annual Museum Day. In the exhibit, visitors will wear HoloLens headsets and watch Jemison materialize before their eyes, taking them on a tour of the Space Shuttle Enterprise—and through space history. They’re invited to explore artifacts both physical (like the Enterprise) and digital (like a galaxy of AR stars) while Jemison introduces women throughout history who have made important contributions to space exploration.

Interactive museum exhibits like this are becoming more common as augmented reality tech becomes cheaper, lighter, and easier to create. A few years ago, the gear alone—a dozen HoloLens headsets, which visitors can wear as they file through the exhibit—would have been out of reach. Now, as the technology becomes easier to use and the experiences easier to create, museums are increasingly turning to them as a way to engage visitors—whether that's fleshing out the skeletons on view at the Smithsonian's National Museum of Natural History, or taking a tour of Mars with astronaut Buzz Aldrin (as a hologram, naturally).
'There’s a tremendous opportunity, especially around technology like augmented reality, to engage visitors.'
Chris Barr, director of innovation at the Knight Foundation

At the Intrepid, the holographic Jemison isn't just the docent of the future. She's also a part of the exhibit, a chance for visitors to come face-to-face with an important figure from space history. “I hope that me taking them on this tour, that it makes it a little bit more real,” she says.

State of the Art

Museums have long relied on technology to give context to their exhibits—whether through informational videos, audio guides, or smartphone apps. Augmented reality, in some ways, is just the next iteration of that. It gives curators a chance to layer more information on top of existing exhibits, and to get visitors more involved with what's on view.
Microsoft
"Cultural institutions are asking, ‘How do we ensure our relevancy in the future?’" says Chris Barr, the director of arts and technology innovation at the Knight Foundation, which gave over $1 million this year to support museums using new forms of technology. "We’re looking at tech as part of the toolset that they use to do that. There’s a tremendous opportunity, especially around technology like augmented reality, to engage visitors."

Some museums have experimented with AR to bring damaged or broken artifacts back into their collections, or to remix the collections on view. This year, the San Francisco Museum of Modern Art worked with the design agency frog to create an “augmented reality gallery” to showcase some of René Magritte’s works, currently on view. The Smithsonian National Museum of Natural History put on an exhibit, called Skin and Bones, which lets visitors animate the museum’s collection of skeletons with an AR app on their phones. Even the U.S. Holocaust Memorial Museum has brought one of its exhibits to life, allowing visitors to learn more about the Lithuanian villagers featured in its Tower of Faces display with a companion AR tool.

"Museums are starting to get smarter and smarter about how do we personalize [the experience of visiting a museum], and how do we make those experiences just as magical as the art that you’re seeing," says Barr.

The Intrepid’s exhibit takes it one step further, using HoloLens headsets to bring Jemison alongside visitors as she guides them through the space shuttle. “We want to make sure that while our artifacts create this exciting and tactile opportunity, we want to make sure we’re capturing our current generation in the language they’re speaking,” says Susan Marenoff-Zausner, President of the Intrepid Sea, Air, and Space Museum.

Behind the Scenes

The Intrepid collaborated with Microsoft, which filmed Jemison at its Mixed Reality Capture Studio in San Francisco. The studio space holds a combination of RGB and infrared cameras that capture scenes in 360 degrees, then render a mesh map in 3-D. “The infrared camera see a very densely speckled version of what’s in that scene, which the computer vision algorithms eat for lunch,” says Steve Sullivan, who heads up Microsoft’s Mixed Reality Capture Studios program.
Microsoft
When Microsoft first started licensing its mixed reality capture tech, it expected most of its business to come from celebrities, sports figures, and the entertainment sector in general. But Sullivan says educational and instructional institutions have become another fast-growing part of what the studio creates. “It’s way richer than video, but not radically more expensive,” he says.

Earlier this year, Microsoft worked with London's Natural History Museum to create a "behind-the-scenes" museum tour. The experience involves a holographic David Attenborough, who shepherds visitors around the museum and shares stories about some of the artifacts on display—some of which are real, and some of which are digital renderings. Microsoft also worked with the Kyoto National Museum to create an immersive exhibit showcasing the art of Kennin-ji, the oldest Zen temple in Japan. Wearing a HoloLens headset, visitors could see 400-year-old artifacts fill the walls and ceiling of the museum, while a life-sized hologram of a Zen Buddhist monk toured them around.

“It’s getting museums to think outside of their physical confines,” says Sullivan. “They can have hosts and guides showing you more.”

Other tech companies have partnered with museums to bring their products into the gallery space. In 2017, shortly after introducing its AR platform Tango, Google teamed up with the Detroit Institute of Arts to show off what it could do. Museum visitors could borrow a Tango-enabled smartphone to discover hidden features, like an augmented reality skeleton inside the sarcophagi on view. The Perez Art Museum Miami leveraged Apple's AR Kit to build augmented reality installations in surprising spaces, like the museum's terrace. (Visitors could see the works through their own iPhones, or could borrow one from the museum.) Earlier this year, Intel worked with the Smithsonian to translate an exhibit in its Renwick Gallery to smartphones everywhere, using Snapchat’s augmented reality tech.

Of course, none of these exhibits rely on augmented reality alone. They still point visitors toward real-world objects and make use of the physical space in museums to create exhibitions. But museum curators hope they can engage visitors on a new level, and bring in new audiences altogether. For Jemison, who discovered her love of science on childhood visitors to Chicago's Museum of Science and Industry, using HoloLens headsets is just one more way for museums to "engage curiosity and foster it." If that gets one more kid curious about science and space, then it's all worth it.

Microbiology (updated)

From Wikipedia, the free encyclopedia

An agar plate streaked with microorganisms

Microbiology (from Greek μῑκρος, mīkros, "small"; βίος, bios, "life"; and -λογία, -logia) is the study of microorganisms, those being unicellular (single cell), multicellular (cell colony), or acellular (lacking cells). Microbiology encompasses numerous sub-disciplines including virology, parasitology, mycology and bacteriology

Eukaryotic microorganisms possess membrane-bound cell organelles and include fungi and protists, whereas prokaryotic organisms—all of which are microorganisms—are conventionally classified as lacking membrane-bound organelles and include Bacteria and Archaea. Microbiologists traditionally relied on culture, staining, and microscopy. However, less than 1% of the microorganisms present in common environments can be cultured in isolation using current means. Microbiologists often rely on molecular biology tools such as DNA sequence based identification, for example 16s rRNA gene sequence used for bacteria identification. 

Viruses have been variably classified as organisms, as they have been considered either as very simple microorganisms or very complex molecules. Prions, never considered as microorganisms, have been investigated by virologists, however, as the clinical effects traced to them were originally presumed due to chronic viral infections, and virologists took search—discovering "infectious proteins". 

The existence of microorganisms was predicted many centuries before they were first observed, for example by the Jains in India and by Marcus Terentius Varro in ancient Rome. The first recorded microscope observation was of the fruiting bodies of moulds, by Robert Hooke in 1666, but the Jesuit priest Athanasius Kircher was likely the first to see microbes, which he mentioned observing in milk and putrid material in 1658. Antonie van Leeuwenhoek is considered a father of microbiology as he observed and experimented with microscopic organisms in 1676, using simple microscopes of his own design. Scientific microbiology developed in the 19th century through the work of Louis Pasteur and in medical microbiology Robert Koch.

History

Avicenna hypothesized the existence of microorganisms.

The existence of microorganisms was hypothesized for many centuries before their actual discovery. The existence of unseen microbiological life was postulated by Jainism which is based on Mahavira’s teachings as early as 6th century BCE. Paul Dundas notes that Mahavira asserted the existence of unseen microbiological creatures living in earth, water, air and fire. Jain scriptures describe nigodas which are sub-microscopic creatures living in large clusters and having a very short life, said to pervade every part of the universe, even in tissues of plants and flesh of animals. The Roman Marcus Terentius Varro made references to microbes when he warned against locating a homestead in the vicinity of swamps "because there are bred certain minute creatures which cannot be seen by the eyes, which float in the air and enter the body through the mouth and nose and thereby cause serious diseases."

In the golden age of Islamic civilization, Iranian scientists hypothesized the existence of microorganisms, such as Avicenna in his book The Canon of Medicine, Ibn Zuhr (also known as Avenzoar) who discovered scabies mites, and Al-Razi who gave the earliest known description of smallpox in his book The Virtuous Life (al-Hawi).

In 1546, Girolamo Fracastoro proposed that epidemic diseases were caused by transferable seedlike entities that could transmit infection by direct or indirect contact, or vehicle transmission.

Antonie van Leeuwenhoek, often cited as the first to experiment with microorganisms.
 
Schematic drawings
Van Leeuwenhoek's microscopes by Henry Baker
]
Martinus Beijerinck, the founding father of the Delft School of Microbiology, in his laboratory. Beijerinck is often considered as a founder of virology, environmental microbiology, and industrial microbiology.
 
In 1676, Antonie van Leeuwenhoek, who lived most of his life in Delft, Holland, observed bacteria and other microorganisms using a single-lens microscope of his own design. He is considered a father of microbiology as he pioneered the use of simple single-lensed microscopes of his own design. While Van Leeuwenhoek is often cited as the first to observe microbes, Robert Hooke made his first recorded microscopic observation, of the fruiting bodies of moulds, in 1665. It has, however, been suggested that a Jesuit priest called Athanasius Kircher was the first to observe microorganisms.

Kircher was among the first to design magic lanterns for projection purposes, so he must have been well acquainted with the properties of lenses. He wrote "Concerning the wonderful structure of things in nature, investigated by Microscope" in 1646, stating "who would believe that vinegar and milk abound with an innumerable multitude of worms." He also noted that putrid material is full of innumerable creeping animalcules. He published his Scrutinium Pestis (Examination of the Plague) in 1658, stating correctly that the disease was caused by microbes, though what he saw was most likely red or white blood cells rather than the plague agent itself.

The birth of bacteriology

Innovative laboratory glassware and experimental methods developed by Louis Pasteur and other biologists contributed to the young field of bacteriology in the late 19th century.
 
The field of bacteriology (later a subdiscipline of microbiology) was founded in the 19th century by Ferdinand Cohn, a botanist whose studies on algae and photosynthetic bacteria led him to describe several bacteria including Bacillus and Beggiatoa. Cohn was also the first to formulate a scheme for the taxonomic classification of bacteria, and to discover endospores. Louis Pasteur and Robert Koch were contemporaries of Cohn, and are often considered to be the father of microbiology and medical microbiology, respectively. Pasteur is most famous for his series of experiments designed to disprove the then widely held theory of spontaneous generation, thereby solidifying microbiology’s identity as a biological science. One of his students, Adrien Certes, is considered the founder of marine microbiology. Pasteur also designed methods for food preservation (pasteurization) and vaccines against several diseases such as anthrax, fowl cholera and rabies. Koch is best known for his contributions to the germ theory of disease, proving that specific diseases were caused by specific pathogenic microorganisms. He developed a series of criteria that have become known as the Koch's postulates. Koch was one of the first scientists to focus on the isolation of bacteria in pure culture resulting in his description of several novel bacteria including Mycobacterium tuberculosis, the causative agent of tuberculosis.

While Pasteur and Koch are often considered the founders of microbiology, their work did not accurately reflect the true diversity of the microbial world because of their exclusive focus on microorganisms having direct medical relevance. It was not until the late 19th century and the work of Martinus Beijerinck and Sergei Winogradsky that the true breadth of microbiology was revealed. Beijerinck made two major contributions to microbiology: the discovery of viruses and the development of enrichment culture techniques. While his work on the tobacco mosaic virus established the basic principles of virology, it was his development of enrichment culturing that had the most immediate impact on microbiology by allowing for the cultivation of a wide range of microbes with wildly different physiologies. Winogradsky was the first to develop the concept of chemolithotrophy and to thereby reveal the essential role played by microorganisms in geochemical processes. He was responsible for the first isolation and description of both nitrifying and nitrogen-fixing bacteria. French-Canadian microbiologist Felix d'Herelle co-discovered bacteriophages in 1917 and was one of the earliest applied microbiologists.

Joseph Lister was the first to use phenol disinfectant on the open wounds of patients.

Branches

A university food microbiology laboratory

The branches of microbiology can be classified into pure and applied sciences, or divided according to taxonomy, as is the case with bacteriology, mycology, protozoology, and phycology. There is considerable overlap between the specific branches of microbiology with each other and with other disciplines, and certain aspects of these branches can extend beyond the traditional scope of microbiology A pure research branch of microbiology is termed cellular microbiology.

Applications

Fermenting tanks with yeast being used to brew beer
 
While some fear microbes due to the association of some microbes with various human diseases, many microbes are also responsible for numerous beneficial processes such as industrial fermentation (e.g. the production of alcohol, vinegar and dairy products), antibiotic production and act as molecular vehicles to transfer DNA to complex organisms such as plants and animals. Scientists have also exploited their knowledge of microbes to produce biotechnologically important enzymes such as Taq polymerase, reporter genes for use in other genetic systems and novel molecular biology techniques such as the yeast two-hybrid system.

Bacteria can be used for the industrial production of amino acids. Corynebacterium glutamicum is one of the most important bacterial species with an annual production of more than two million tons of amino acids, mainly L-glutamate and L-lysine. Since some bacteria have the ability to synthesize antibiotics, they are used for medicinal purposes, such as Streptomyces to make aminoglycoside antibiotics.

A variety of biopolymers, such as polysaccharides, polyesters, and polyamides, are produced by microorganisms. Microorganisms are used for the biotechnological production of biopolymers with tailored properties suitable for high-value medical application such as tissue engineering and drug delivery. Microorganisms are for example used for the biosynthesis of xanthan, alginate, cellulose, cyanophycin, poly(gamma-glutamic acid), levan, hyaluronic acid, organic acids, oligosaccharides polysaccharide and polyhydroxyalkanoates.

Microorganisms are beneficial for microbial biodegradation or bioremediation of domestic, agricultural and industrial wastes and subsurface pollution in soils, sediments and marine environments. The ability of each microorganism to degrade toxic waste depends on the nature of each contaminant. Since sites typically have multiple pollutant types, the most effective approach to microbial biodegradation is to use a mixture of bacterial and fungal species and strains, each specific to the biodegradation of one or more types of contaminants.

Symbiotic microbial communities confer benefits to their human and animal hosts health including aiding digestion, producing beneficial vitamins and amino acids, and suppressing pathogenic microbes. Some benefit may be conferred by eating fermented foods, probiotics (bacteria potentially beneficial to the digestive system) or prebiotics (substances consumed to promote the growth of probiotic microorganisms). The ways the microbiome influences human and animal health, as well as methods to influence the microbiome are active areas of research.

Research has suggested that microorganisms could be useful in the treatment of cancer. Various strains of non-pathogenic clostridia can infiltrate and replicate within solid tumors. Clostridial vectors can be safely administered and their potential to deliver therapeutic proteins has been demonstrated in a variety of preclinical models.

Introduction to entropy

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