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Spectrum Of A Boolean Algebra
A spectrum (plural ''spectra'' or ''spectrums'') is a condition that is not limited to a specific set of values but can vary, without gaps, across a continuum. The word was first used scientifically in optics to describe the rainbow of colors in visible light after passing through a prism. As scientific understanding of light advanced, it came to apply to the entire electromagnetic spectrum. It thereby became a mapping of a range of magnitudes (wavelengths) to a range of qualities, which are the perceived "colors of the rainbow" and other properties which correspond to wavelengths that lie outside of the visible light spectrum. Spectrum has since been applied by analogy to topics outside optics. Thus, one might talk about the " spectrum of political opinion", or the "spectrum of activity" of a drug, or the "autism spectrum". In these uses, values within a spectrum may not be associated with precisely quantifiable numbers or definitions. Such uses imply a broad range of conditio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rainbow Above Kaviskis Lake, Lithuania
A rainbow is a meteorological phenomenon that is caused by reflection, refraction and dispersion of light in water droplets resulting in a spectrum of light appearing in the sky. It takes the form of a multicoloured circular arc. Rainbows caused by sunlight always appear in the section of sky directly opposite the Sun. Rainbows can be full circles. However, the observer normally sees only an arc formed by illuminated droplets above the ground, and centered on a line from the Sun to the observer's eye. In a primary rainbow, the arc shows red on the outer part and violet on the inner side. This rainbow is caused by light being refracted when entering a droplet of water, then reflected inside on the back of the droplet and refracted again when leaving it. In a double rainbow, a second arc is seen outside the primary arc, and has the order of its colours reversed, with red on the inner side of the arc. This is caused by the light being reflected twice on the inside of the dropl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Salem, Massachusetts
Salem ( ) is a historic coastal city in Essex County, Massachusetts, located on the North Shore of Greater Boston. Continuous settlement by Europeans began in 1626 with English colonists. Salem would become one of the most significant seaports trading commodities in early American history. It is a suburb of Boston. Today Salem is a residential and tourist area that is home to the House of Seven Gables, Salem State University, Pioneer Village, the Salem Maritime National Historic Site, Salem Willows Park, and the Peabody Essex Museum. It features historic residential neighborhoods in the Federal Street District and the Charter Street Historic District.Peabody Essex announces $650 million campaign WickedLocal.com, November 14, 2011 [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dicloxacillin
Dicloxacillin is a narrow-spectrum β-lactam antibiotic of the penicillin class. It is used to treat infections caused by susceptible (non-resistant) Gram-positive bacteria.Product Information: DICLOXACILLIN SODIUM-dicloxacillin sodium capsule. Teva Pharmaceuticals USA Inc, Revised 8/2015 It is active against beta-lactamase-producing organisms such as ''Staphylococcus aureus'', which would otherwise be resistant to most penicillins. Dicloxacillin is available under a variety of trade names including Diclocil ( BMS). It was patented in 1961 and approved for medical use in 1968. Medical uses Dicloxacillin is used to treat mild-to-moderate staphylococcal infections. To decrease the development of resistance, dicloxacillin is recommended to treat infections that are suspected or proven to be caused by beta-lactamase-producing bacteria. Dicloxacillin is similar in pharmacokinetics, antibacterial activity, and indications to flucloxacillin, and the two agents are considered interchan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ampicillin
Ampicillin is an antibiotic used to prevent and treat a number of bacterial infections, such as respiratory tract infections, urinary tract infections, meningitis, salmonellosis, and endocarditis. It may also be used to prevent group B streptococcal infection in newborns. It is used by mouth, by injection into a muscle, or intravenously. Common side effects include rash, nausea, and diarrhea. It should not be used in people who are allergic to penicillin. Serious side effects may include ''Clostridium difficile'' colitis or anaphylaxis. While usable in those with kidney problems, the dose may need to be decreased. Its use during pregnancy and breastfeeding appears to be generally safe. Ampicillin was discovered in 1958 and came into commercial use in 1961. It is on the World Health Organization's List of Essential Medicines. The World Health Organization classifies ampicillin as critically important for human medicine. It is available as a generic medication. Medical u ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Narrow-spectrum Antibiotic
A narrow-spectrum antibiotic is an antibiotic that is only able to kill or inhibit limited species of bacteria. Examples of narrow-spectrum antibiotics include fidaxomicin and sarecycline. Advantages * Narrow-spectrum antibiotic allow to kill or inhibit only those bacteria species that are unwanted (i.e. causing disease). As such, it leaves most of the beneficial bacteria unaffected, hence minimizing the collateral damage on the microbiota. *Low propensity for bacterial resistance development. Disadvantages Often, the exact species of bacteria causing the illness is unknown, in which case narrow-spectrum antibiotics can't be used, and broad-spectrum antibiotics are used instead. To know the exact species of bacteria causing the illness, clinical specimens need to be taken for antimicrobial susceptibility testing in a clinical microbiology laboratory. See also * Broad-spectrum antibiotic A broad-spectrum antibiotic is an antibiotic that acts on the two major bacterial groups, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Broad-spectrum Antibiotic
A broad-spectrum antibiotic is an antibiotic that acts on the two major bacterial groups, Gram-positive and Gram-negative, or any antibiotic that acts against a wide range of disease-causing bacteria. These medications are used when a bacterial infection is suspected but the group of bacteria is unknown (also called empiric therapy) or when infection with multiple groups of bacteria is suspected. This is in contrast to a narrow-spectrum antibiotic, which is effective against only a specific group of bacteria. Although powerful, broad-spectrum antibiotics pose specific risks, particularly the disruption of native, normal bacteria and the development of antimicrobial resistance. An example of a commonly used broad-spectrum antibiotic is ampicillin. Bacterial targets Antibiotics are often grouped by their ability to act on different bacterial groups. Although bacteria are biologically classified using taxonomy, disease-causing bacteria have historically been classified by their ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antibiotic
An antibiotic is a type of antimicrobial substance active against bacteria. It is the most important type of antibacterial agent for fighting bacterial infections, and antibiotic medications are widely used in the treatment and prevention of such infections. They may either kill or inhibit the growth of bacteria. A limited number of antibiotics also possess antiprotozoal activity. Antibiotics are not effective against viruses such as the common cold or influenza; drugs which inhibit viruses are termed antiviral drugs or antivirals rather than antibiotics. Sometimes, the term ''antibiotic''—literally "opposing life", from the Greek roots ἀντι ''anti'', "against" and βίος ''bios'', "life"—is broadly used to refer to any substance used against microbes, but in the usual medical usage, antibiotics (such as penicillin) are those produced naturally (by one microorganism fighting another), whereas non-antibiotic antibacterials (such as sulfonamides and antise ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemical Analysis
Analytical chemistry studies and uses instruments and methods to separate, identify, and quantify matter. In practice, separation, identification or quantification may constitute the entire analysis or be combined with another method. Separation isolates analytes. Qualitative analysis identifies analytes, while quantitative analysis determines the numerical amount or concentration. Analytical chemistry consists of classical, wet chemical methods and modern, instrumental methods. Classical qualitative methods use separations such as precipitation, extraction, and distillation. Identification may be based on differences in color, odor, melting point, boiling point, solubility, radioactivity or reactivity. Classical quantitative analysis uses mass or volume changes to quantify amount. Instrumental methods may be used to separate samples using chromatography, electrophoresis or field flow fractionation. Then qualitative and quantitative analysis can be performed, often with t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spectroscopy
Spectroscopy is the field of study that measures and interprets the electromagnetic spectra that result from the interaction between electromagnetic radiation and matter as a function of the wavelength or frequency of the radiation. Matter waves and acoustic waves can also be considered forms of radiative energy, and recently gravitational waves have been associated with a spectral signature in the context of the Laser Interferometer Gravitational-Wave Observatory (LIGO) In simpler terms, spectroscopy is the precise study of color as generalized from visible light to all bands of the electromagnetic spectrum. Historically, spectroscopy originated as the study of the wavelength dependence of the absorption by gas phase matter of visible light dispersed by a prism. Spectroscopy, primarily in the electromagnetic spectrum, is a fundamental exploratory tool in the fields of astronomy, chemistry, materials science, and physics, allowing the composition, physical structure an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spectrometer
A spectrometer () is a scientific instrument used to separate and measure spectral components of a physical phenomenon. Spectrometer is a broad term often used to describe instruments that measure a continuous variable of a phenomenon where the spectral components are somehow mixed. In visible light a spectrometer can separate white light and measure individual narrow bands of color, called a spectrum. A mass spectrometer measures the spectrum of the masses of the atoms or molecules present in a gas. The first spectrometers were used to split light into an array of separate colors. Spectrometers were developed in early studies of physics, astronomy, and chemistry. The capability of spectroscopy to determine chemical composition drove its advancement and continues to be one of its primary uses. Spectrometers are used in astronomy to analyze the chemical composition of stars and planets, and spectrometers gather data on the origin of the universe. Examples of spectrometers are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
On Vision And Colors
''On Vision and Colors'' (originally translated as ''On Vision and Colours''; german: Ueber das Sehn und die Farben) is a treatise by Arthur Schopenhauer that was published in May 1816 when the author was 28 years old. Schopenhauer had extensive discussions with Johann Wolfgang von Goethe about the poet's '' Theory of Colours'' of 1810, in the months around the turn of the years 1813 and 1814, and initially shared Goethe's views.Karl Robert Mandelkow, Bodo Morawe: Goethes Briefe (''Goethe's Letters''). 1. edition. Vol. 3: Briefe der Jahre 1805-1821 (''Letters of the years 1805-1821''). ''Christian Wegner'' publishers, Hamburg 1965, p. 639. "Vom November 1813 bis zum Mai 1814 sind sie in Weimar sehr häufig zusammengewesen. (...) In den Mittelpunkt der Diskussionen rückte schließlich die Goethesche ''Farbenlehre''. Schopenhauer teilte prinzipiell die Ansichten des Dichters, wich jedoch in gewissen Einzelheiten von ihnen ab." (''"From November 1813 till May 1814, they ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arthur Schopenhauer
Arthur Schopenhauer ( , ; 22 February 1788 – 21 September 1860) was a German philosopher. He is best known for his 1818 work ''The World as Will and Representation'' (expanded in 1844), which characterizes the phenomenal world as the product of a blind noumenal will. Building on the transcendental idealism of Immanuel Kant (1724–1804), Schopenhauer developed an atheistic metaphysical and ethical system that rejected the contemporaneous ideas of German idealism. He was among the first thinkers in Western philosophy to share and affirm significant tenets of Indian philosophy, such as asceticism, denial of the self, and the notion of the world-as-appearance. His work has been described as an exemplary manifestation of philosophical pessimism. Though his work failed to garner substantial attention during his lifetime, Schopenhauer had a posthumous impact across various disciplines, including philosophy, literature, and science. His writing on aesthetics, morality, and ps ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
