Parabens are a class of used preservatives in cosmetic and pharmaceutical products. Chemically, they are a series of esters of parahydroxybenzoic acid. Parabens are effective preservatives in many types of formulas; these compounds, their salts, are used for their bactericidal and fungicidal properties. They are found in shampoos, commercial moisturizers, shaving gels, personal lubricants, topical/parenteral pharmaceuticals, suntan products and toothpaste, they are used as food preservatives. No effective direct links between parabens and cancer have been established. Parabens are active against a broad spectrum of microorganisms. However, their antibacterial mode of action is not well understood, they are thought to act by disrupting membrane transport processes or by inhibiting synthesis of DNA and RNA or of some key enzymes, such as ATPases and phosphotransferases, in some bacterial species. Propylparaben is considered more active against most bacteria than methylparaben; the stronger antibacterial action of propylparaben may be due to its greater solubility in the bacterial membrane, which may allow it to reach cytoplasmic targets in greater concentrations.
However, since a majority of the studies on the mechanism of action of parabens suggest that their antibacterial action is linked to the membrane, it is possible that its greater lipid solubility disrupts the lipid bilayer, thereby interfering with bacterial membrane transport processes and causing the leakage of intracellular constituents. Parabens are esters of para-hydroxybenzoic acid. Common parabens include methylparaben, propylparaben and heptylparaben. Less common parabens include isobutylparaben, isopropylparaben and their sodium salts; the general chemical structure of a paraben is shown at the top right of this page, where R symbolizes an alkyl group such as methyl, propyl or butyl. All commercially used parabens are synthetically produced, although some are identical to those found in nature, they are produced by the esterification of para-hydroxybenzoic acid with the appropriate alcohol, such as methanol, ethanol, or n-propanol. Para-Hydroxybenzoic acid is in turn produced industrially from a modification of the Kolbe-Schmitt reaction, using potassium phenoxide and carbon dioxide.
Most of the available paraben toxicity data are from single-exposure studies, meaning one type of paraben in one type of product. According to paraben research this is safe, posing only a negligible risk to the endocrine system. However, since many types of parabens in many types of products are used further assessment of the additive and cumulative risk of multiple paraben exposure from daily use of multiple cosmetic and/or personal care products is needed. FDA states, they continue to consider certain questions and evaluate data about parabens' possible health effects. In individuals with normal skin, parabens are, for the most part, non-irritating and non-sensitizing. Parabens can, cause skin irritation and contact dermatitis and rosacea in individuals with paraben allergies, a small percentage of the general population; the American Cancer Society mentioned a 2004 study that found parabens in the breast tissue of mastectomy patients but did not find parabens to be a cause of the cancers. Michael Thun of ACS stated that the effects of parabens would be miniscule compared to other risks "such as taking hormones after menopause and being overweight".
A 2005 review concluded "it is biologically implausible that parabens could increase the risk of any estrogen-mediated endpoint, including effects on the male reproductive tract or breast cancer" and that "worst-case daily exposure to parabens would present less risk relative to exposure to occurring endocrine active chemicals in the diet such as the phytoestrogen daidzein." Animal experiments have shown. In an in vivo study, the effect of butylparaben was determined to be about 1/100,000th that of estradiol, was only observed at a dose level around 25,000 times higher than the level used to preserve products; the study found that the in vivo estrogenic activity of parabens is reduced by about three orders of magnitude compared to in vitro activity. The estrogenic activity of parabens increases with the length of the alkyl group, it is believed that propylparaben is estrogenic to a certain degree as well, though this is expected to be less than butylparaben by virtue of its less lipophilic nature.
Since it can be concluded that the estrogenic activity of butylparaben is negligible under normal use, the same should be concluded for shorter analogs due to estrogenic activity of parabens increasing with the length of the alkyl group. Studies indicate that methylparaben applied on the skin may react with UVB leading to increased skin aging, skin cancer and DNA damage; the European Scientific Committee on Consumer Safety reiterated in 2013 that methylparaben and ethylparaben are safe at the maximum authorized concentrations. The SCCS concluded that the use of butylparaben and propylparaben as preservatives in finished cosmetic products is safe to the consumer, as long as the sum of their individual concentrations does not exceed 0,19 %. Isopropylparaben, phenylparaben and pentylparaben were banned by Commission Regulation No 358/2014. A 2004 paper led to discussion over possible carcinogenicity and estrogenic effects being expressed over the
Medieval Latin was the form of Latin used in Roman Catholic Western Europe during the Middle Ages. In this region it served as the primary written language, though local languages were written to varying degrees. Latin functioned as the main medium of scholarly exchange, as the liturgical language of the Church, as the working language of science, literature and administration. Medieval Latin represented, in essence, a continuation of Classical Latin and Late Latin, with enhancements for new concepts as well as for the increasing integration of Christianity. Despite some meaningful differences from Classical Latin, Medieval writers did not regard it as a fundamentally different language. There is no real consensus on the exact boundary where Late Latin Medieval Latin begins; some scholarly surveys begin with the rise of early Ecclesiastical Latin in the middle of the 4th century, others around 500, still others with the replacement of written Late Latin by written Romance languages starting around the year 900.
The terms Medieval Latin and Ecclesiastical Latin are used synonymously, though some scholars draw distinctions. Ecclesiastical Latin refers to the form, used by the Roman Catholic Church, whereas Medieval Latin refers more broadly to all of the forms of Latin used in the Middle Ages; the Romance languages spoken in the Middle Ages were referred to as Latin, since the Romance languages were all descended from Classical, or Roman, Latin itself. Medieval Latin had an enlarged vocabulary, which borrowed from other sources, it was influenced by the language of the Vulgate, which contained many peculiarities alien to Classical Latin that resulted from a more or less direct translation from Greek and Hebrew. Greek provided much of the technical vocabulary of Christianity; the various Germanic languages spoken by the Germanic tribes, who invaded southern Europe, were major sources of new words. Germanic leaders became the rulers of parts of the Roman Empire that they conquered, words from their languages were imported into the vocabulary of law.
Other more ordinary words were replaced by coinages from Vulgar Latin or Germanic sources because the classical words had fallen into disuse. Latin was spread to areas such as Ireland and Germany, where Romance languages were not spoken, which had never known Roman rule. Works written in those lands where Latin was a learned language, having no relation to the local vernacular influenced the vocabulary and syntax of medieval Latin. Since subjects like science and philosophy, including Argumentation theory and Ethics, were communicated in Latin, the Latin vocabulary that developed for them became the source of a great many technical words in modern languages. English words like abstract, communicate, matter and their cognates in other European languages have the meanings given to them in medieval Latin; the influence of Vulgar Latin was apparent in the syntax of some medieval Latin writers, although Classical Latin continued to be held in high esteem and studied as models for literary compositions.
The high point of the development of medieval Latin as a literary language came with the Carolingian renaissance, a rebirth of learning kindled under the patronage of Charlemagne, king of the Franks. Alcuin was an important writer in his own right. Although it was developing into the Romance languages, Latin itself remained conservative, as it was no longer a native language and there were many ancient and medieval grammar books to give one standard form. On the other hand speaking there was no single form of "medieval Latin"; every Latin author in the medieval period spoke Latin as a second language, with varying degrees of fluency and syntax. Grammar and vocabulary, were influenced by an author's native language; this was true beginning around the 12th century, after which the language became adulterated: late medieval Latin documents written by French speakers tend to show similarities to medieval French grammar and vocabulary. For instance, rather than following the classical Latin practice of placing the verb at the end, medieval writers would follow the conventions of their own native language instead.
Whereas Latin had no definite or indefinite articles, medieval writers sometimes used forms of unus as an indefinite article, forms of ille as a definite article or quidam as something like an article. Unlike classical Latin, where esse was the only auxiliary verb, medieval Latin writers might use habere as an auxiliary, similar to constructions in Germanic and Romance languages; the accusative and infinitive construction in classical Latin was replaced by a subordinate clause introduced by quod or quia. This is identical, for example, to the use of que in similar constructions in French. In every age from the late 8th century onwards, there were learned writers who were familiar enough with classical syntax to be aware that these forms and usages were "wrong" and resisted their use, thus the Latin of a theologian like St Thomas Aquinas or of an erudite clerical historian such as William of Tyre tends to avoid most of the characteristics described above, showing its p
Encyclopædia Britannica, Eleventh Edition
The Encyclopædia Britannica, Eleventh Edition is a 29-volume reference work, an edition of the Encyclopædia Britannica. It was developed during the encyclopaedia's transition from a British to an American publication; some of its articles were written by the best-known scholars of the time. This edition of the encyclopedia, containing 40,000 entries, is now in the public domain, many of its articles have been used as a basis for articles in Wikipedia. However, the outdated nature of some of its content makes its use as a source for modern scholarship problematic; some articles have special value and interest to modern scholars as cultural artifacts of the 19th and early 20th centuries. The 1911 eleventh edition was assembled with the management of American publisher Horace Everett Hooper. Hugh Chisholm, who had edited the previous edition, was appointed editor in chief, with Walter Alison Phillips as his principal assistant editor. Hooper bought the rights to the 25-volume 9th edition and persuaded the British newspaper The Times to issue its reprint, with eleven additional volumes as the tenth edition, published in 1902.
Hooper's association with The Times ceased in 1909, he negotiated with the Cambridge University Press to publish the 29-volume eleventh edition. Though it is perceived as a quintessentially British work, the eleventh edition had substantial American influences, not only in the increased amount of American and Canadian content, but in the efforts made to make it more popular. American marketing methods assisted sales; some 14% of the contributors were from North America, a New York office was established to coordinate their work. The initials of the encyclopedia's contributors appear at the end of selected articles or at the end of a section in the case of longer articles, such as that on China, a key is given in each volume to these initials; some articles were written by the best-known scholars of the time, such as Edmund Gosse, J. B. Bury, Algernon Charles Swinburne, John Muir, Peter Kropotkin, T. H. Huxley, James Hopwood Jeans and William Michael Rossetti. Among the lesser-known contributors were some who would become distinguished, such as Ernest Rutherford and Bertrand Russell.
Many articles were carried over from some with minimal updating. Some of the book-length articles were divided into smaller parts for easier reference, yet others much abridged; the best-known authors contributed only a single article or part of an article. Most of the work was done by British Museum scholars and other scholars; the 1911 edition was the first edition of the encyclopædia to include more than just a handful of female contributors, with 34 women contributing articles to the edition. The eleventh edition introduced a number of changes of the format of the Britannica, it was the first to be published complete, instead of the previous method of volumes being released as they were ready. The print type was subject to continual updating until publication, it was the first edition of Britannica to be issued with a comprehensive index volume in, added a categorical index, where like topics were listed. It was the first not to include long treatise-length articles. Though the overall length of the work was about the same as that of its predecessor, the number of articles had increased from 17,000 to 40,000.
It was the first edition of Britannica to include biographies of living people. Sixteen maps of the famous 9th edition of Stielers Handatlas were translated to English, converted to Imperial units, printed in Gotha, Germany by Justus Perthes and became part this edition. Editions only included Perthes' great maps as low quality reproductions. According to Coleman and Simmons, the content of the encyclopedia was distributed as follows: Hooper sold the rights to Sears Roebuck of Chicago in 1920, completing the Britannica's transition to becoming a American publication. In 1922, an additional three volumes, were published, covering the events of the intervening years, including World War I. These, together with a reprint of the eleventh edition, formed the twelfth edition of the work. A similar thirteenth edition, consisting of three volumes plus a reprint of the twelfth edition, was published in 1926, so the twelfth and thirteenth editions were related to the eleventh edition and shared much of the same content.
However, it became apparent that a more thorough update of the work was required. The fourteenth edition, published in 1929, was revised, with much text eliminated or abridged to make room for new topics; the eleventh edition was the basis of every version of the Encyclopædia Britannica until the new fifteenth edition was published in 1974, using modern information presentation. The eleventh edition's articles are still of value and interest to modern readers and scholars as a cultural artifact: the British Empire was at its maximum, imperialism was unchallenged, much of the world was still ruled by monarchs, the tragedy of the modern world wars was still in the future, they are an invaluable resource for topics omitted from modern encyclopedias for biography and the history of science and technology. As a literary text, the encyclopedia has value as an example of early 20th-century prose. For example, it employs literary devices, such as pathetic fallacy, which are not as common in modern reference texts.
In 1917, using the pseudonym of S. S. Van Dine, the US art critic and author Willard Huntington Wright published Misinforming a Nation, a 200+
Arabic is a Central Semitic language that first emerged in Iron Age northwestern Arabia and is now the lingua franca of the Arab world. It is named after the Arabs, a term used to describe peoples living in the area bounded by Mesopotamia in the east and the Anti-Lebanon mountains in the west, in northwestern Arabia, in the Sinai Peninsula. Arabic is classified as a macrolanguage comprising 30 modern varieties, including its standard form, Modern Standard Arabic, derived from Classical Arabic; as the modern written language, Modern Standard Arabic is taught in schools and universities, is used to varying degrees in workplaces and the media. The two formal varieties are grouped together as Literary Arabic, the official language of 26 states, the liturgical language of the religion of Islam, since the Quran and Hadith were written in Arabic. Modern Standard Arabic follows the grammatical standards of Classical Arabic, uses much of the same vocabulary. However, it has discarded some grammatical constructions and vocabulary that no longer have any counterpart in the spoken varieties, has adopted certain new constructions and vocabulary from the spoken varieties.
Much of the new vocabulary is used to denote concepts that have arisen in the post-classical era in modern times. Due to its grounding in Classical Arabic, Modern Standard Arabic is removed over a millennium from everyday speech, construed as a multitude of dialects of this language; these dialects and Modern Standard Arabic are described by some scholars as not mutually comprehensible. The former are acquired in families, while the latter is taught in formal education settings. However, there have been studies reporting some degree of comprehension of stories told in the standard variety among preschool-aged children; the relation between Modern Standard Arabic and these dialects is sometimes compared to that of Latin and vernaculars in medieval and early modern Europe. This view though does not take into account the widespread use of Modern Standard Arabic as a medium of audiovisual communication in today's mass media—a function Latin has never performed. During the Middle Ages, Literary Arabic was a major vehicle of culture in Europe in science and philosophy.
As a result, many European languages have borrowed many words from it. Arabic influence in vocabulary, is seen in European languages Spanish and to a lesser extent Portuguese, Catalan, owing to both the proximity of Christian European and Muslim Arab civilizations and 800 years of Arabic culture and language in the Iberian Peninsula, referred to in Arabic as al-Andalus. Sicilian has about 500 Arabic words as result of Sicily being progressively conquered by Arabs from North Africa, from the mid-9th to mid-10th centuries. Many of these words relate to related activities; the Balkan languages, including Greek and Bulgarian, have acquired a significant number of Arabic words through contact with Ottoman Turkish. Arabic has influenced many languages around the globe throughout its history; some of the most influenced languages are Persian, Spanish, Kashmiri, Bosnian, Bengali, Malay, Indonesian, Punjabi, Assamese, Sindhi and Hausa, some languages in parts of Africa. Conversely, Arabic has borrowed words from other languages, including Greek and Persian in medieval times, contemporary European languages such as English and French in modern times.
Classical Arabic is the liturgical language of 1.8 billion Muslims, Modern Standard Arabic is one of six official languages of the United Nations. All varieties of Arabic combined are spoken by as many as 422 million speakers in the Arab world, making it the fifth most spoken language in the world. Arabic is written with the Arabic alphabet, an abjad script and is written from right to left, although the spoken varieties are sometimes written in ASCII Latin from left to right with no standardized orthography. Arabic is a Central Semitic language related to the Northwest Semitic languages, the Ancient South Arabian languages, various other Semitic languages of Arabia such as Dadanitic; the Semitic languages changed a great deal between Proto-Semitic and the establishment of the Central Semitic languages in grammar. Innovations of the Central Semitic languages—all maintained in Arabic—include: The conversion of the suffix-conjugated stative formation into a past tense; the conversion of the prefix-conjugated preterite-tense formation into a present tense.
The elimination of other prefix-conjugated mood/aspect forms in favor of new moods formed by endings attached to the prefix-conjugation forms. The development of an internal passive. There are several features which Classical Arabic, the modern Arabic varieties, as well as the Safaitic and Hismaic inscriptions share which are unattested in any other Central Semitic language variety, including the Dadanitic and Taymanitic languages of the northern Hejaz; these features are evidence of common descent from Proto-Arabic. The following features can be reconstructed with confidence for Proto-Arabic: negative particles m *mā.
Effervescent or carbon tablets are tablets which are designed to dissolve in water, release carbon dioxide. They are products of compression of component ingredients in the form of powders into a dense mass, packaged in blister pack, or with a hermetically sealed package with incorporated desiccant in the cap. To use them, they are dropped into water to make a solution; the powdered ingredients are packaged and sold as effervescent powders or may be granulated and sold as effervescent granules. Powdered ingredients are first granularized before being made into tablets. Effervescent medicinal beverages date back to the late 1800s and arose to mask the taste of bitter waters taken as curatives, during the water cure craze of that era. In the 17th and 18th centuries, scientists began uncovering the chemical make-up and physiological benefits of various salts such as Glauber's salt and Epsom salts; these salts were found in mineral springs, since the Roman Empire, had been used as health spas, where people would go to bathe in, drink, mineral-rich waters for their health.
These developments led to attempts to replicate the salt mixtures found in these occurring mineral waters using off-the-shelf ingredients. Mixing these kinds of salts — carbonates and tartrates — with flavorings like lemon into an effervescent compound with citric or tartaric acid proved popular and set off a craze for the new "fruit salts". Effervescent tablets have been used as products of the pharmaceutical and dietary industries for over two centuries. Vitamin tablets may be sold as effervescent tablets. Alka-selzer is an pain reliever sold as an effervescent powder. There are several categories of active ingredients that may be best administered in the form of effervescent preparations: Those that are difficult to digest or disruptive to the stomach or esophagus Those that are pH–sensitive, such as amino acids and antibiotics; those requiring a large dose. Those that are susceptible to oxygen, or moisture. Other Cleaning tablets may be filled tubs of water; some tablets used for dying eggs for Easter are effervescent.
Baynes, T. S. ed. "Baden", Encyclopædia Britannica, 3, New York: Charles Scribner's Sons, pp. 226–227 Chisholm, Hugh, ed. "Baden", Encyclopædia Britannica, 3, Cambridge University Press, p. 184 "Baden-Baden", Encyclopædia Britannica Online, 2015, retrieved 8 October 2015
Decoction is a method of extraction by boiling herbal or plant material to dissolve the chemicals of the material, which may include stems, roots and rhizomes. Decoction involves first mashing the plant material to allow for maximum dissolution, boiling in water to extract oils, volatile organic compounds and other various chemical substances. Decoction can be used to make herbal teas, leaf teas, coffees and similar solutions. Decoctions and infusions may produce liquids with differing chemical properties as the temperature and/or preparation difference may result in more oil-soluble chemicals in decoctions versus infusions; the process can be applied to meats and vegetables to prepare bouillon or stock, though the term is only used to describe boiled plant extracts for medicinal or scientific purposes. Decoction is the name for the resulting liquid. Although this method of extraction differs from infusion and percolation, the resultant liquids can sometimes be similar in their effects, or general appearance and taste.
The term dates back to 1350–1400 from present participle stem of Latin decoquere, de "from" + coquere "to cook". In brewing, decoction mashing is the traditional method where a portion of the mash is removed to a separate vessel, boiled for a time and returned to the main mash, raising the mash to the next temperature step. In herbalism, decoctions are made to extract fluids from hard plant materials such as roots and bark. To achieve this, the plant material is boiled for 1–2 hours in 1-5 liters of water, it is strained. Ayurveda utilizes this method to create Kashayam type of herbal medicines. For teas, decoction involves boiling the same amount of the herb and water that would be used for an infusion for about five to ten minutes. Concoction Percolation Infusion Maceration Tincture Herbalism How To Make a Herbal Decoction from unexplainable.net
Color, or colour, is the characteristic of human visual perception described through color categories, with names such as red, yellow, blue, or purple. This perception of color derives from the stimulation of cone cells in the human eye by electromagnetic radiation in the visible spectrum. Color categories and physical specifications of color are associated with objects through the wavelength of the light, reflected from them; this reflection is governed by the object's physical properties such as light absorption, emission spectra, etc. By defining a color space, colors can be identified numerically by coordinates, which in 1931 were named in global agreement with internationally agreed color names like mentioned above by the International Commission on Illumination; the RGB color space for instance is a color space corresponding to human trichromacy and to the three cone cell types that respond to three bands of light: long wavelengths, peaking near 564–580 nm. There may be more than three color dimensions in other color spaces, such as in the CMYK color model, wherein one of the dimensions relates to a color's colorfulness).
The photo-receptivity of the "eyes" of other species varies from that of humans and so results in correspondingly different color perceptions that cannot be compared to one another. Honeybees and bumblebees for instance have trichromatic color vision sensitive to ultraviolet but is insensitive to red. Papilio butterflies may have pentachromatic vision; the most complex color vision system in the animal kingdom has been found in stomatopods with up to 12 spectral receptor types thought to work as multiple dichromatic units. The science of color is sometimes called chromatics, colorimetry, or color science, it includes the study of the perception of color by the human eye and brain, the origin of color in materials, color theory in art, the physics of electromagnetic radiation in the visible range. Electromagnetic radiation is characterized by its intensity; when the wavelength is within the visible spectrum, it is known as "visible light". Most light sources emit light at many different wavelengths.
Although the spectrum of light arriving at the eye from a given direction determines the color sensation in that direction, there are many more possible spectral combinations than color sensations. In fact, one may formally define a color as a class of spectra that give rise to the same color sensation, although such classes would vary among different species, to a lesser extent among individuals within the same species. In each such class the members are called metamers of the color in question; the familiar colors of the rainbow in the spectrum—named using the Latin word for appearance or apparition by Isaac Newton in 1671—include all those colors that can be produced by visible light of a single wavelength only, the pure spectral or monochromatic colors. The table at right shows approximate wavelengths for various pure spectral colors; the wavelengths listed are as measured in vacuum. The color table should not be interpreted as a definitive list—the pure spectral colors form a continuous spectrum, how it is divided into distinct colors linguistically is a matter of culture and historical contingency.
A common list identifies six main bands: red, yellow, green and violet. Newton's conception included a seventh color, between blue and violet, it is possible that what Newton referred to as blue is nearer to what today is known as cyan, that indigo was the dark blue of the indigo dye, being imported at the time. The intensity of a spectral color, relative to the context in which it is viewed, may alter its perception considerably; the color of an object depends on both the physics of the object in its environment and the characteristics of the perceiving eye and brain. Physically, objects can be said to have the color of the light leaving their surfaces, which depends on the spectrum of the incident illumination and the reflectance properties of the surface, as well as on the angles of illumination and viewing; some objects not only reflect light, but transmit light or emit light themselves, which contributes to the color. A viewer's perception of the object's color depends not only on the spectrum of the light leaving its surface, but on a host of contextual cues, so that color differences between objects can be discerned independent of the lighting spectrum, viewing angle, etc.
This effect is known as color constancy. Some generalizations of the physics can be drawn, neglecting perceptual effects for now: Light arriving at an opaque surface is either reflected "specularly", scattered, or absorbed – or some combination of these. Opaque objects that do not reflect specularly have their color determined by which wavelengths of light they scatter strongly. If objects scatter all wavelengths with r