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Topic Review
The Tryptophan-Kynurenine Metabolic Pathway
Tryptophan (TRP) is one of the essential amino acids, which participates in protein synthesis. The tryptophan’s main metabolic route is the kynurenine pathway (KP) through which approximately 90-95% of TRP degrades into nicotinamide adenine dinucleotide (NAD+) and other bioactive metabolites. The appropriate amount of NAD+ is essential to maintain the operation and the viability of cells. The other molecules are neurotoxic, neuroprotective, oxidant, antioxidant, and/or immune modifiers. They play an important role in the function of the brain and the peripheral tissues. The change in the levels of the bioactive molecules is considered to contribute to the development of a wide range of illnesses from cancer to immunologic, neurodegenerative, and psychiatric diseases.
  • 13.5K
  • 10 Aug 2021
Topic Review
Puruṣārtha
Puruṣārtha (Sanskrit: पुरुषार्थ) literally means an "object of human pursuit". It is a key concept in Hinduism, and refers to the four proper goals or aims of a human life. The four puruṣārthas are Dharma (righteousness, moral values), Artha (prosperity, economic values), Kama (pleasure, love, psychological values) and Moksha (liberation, spiritual values). All four Purusarthas are important, but in cases of conflict, Dharma is considered more important than Artha or Kama in Hindu philosophy. Moksha is considered the ultimate ideal of human life. At the same time, this is not a consensus among all Hindus, and many have different interpretations of the hierarchy, and even as to whether one should exist. Historical Indian scholars recognized and debated the inherent tension between active pursuit of wealth (Artha purusartha) and pleasure (Kama), and renunciation of all wealth and pleasure for the sake of spiritual liberation (Moksha). They proposed "action with renunciation" or "craving-free, dharma-driven action", also called Nishkam Karma as a possible solution to the tension.
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  • 14 Oct 2022
Topic Review
Internet Archive
Coordinates: 37°46′56″N 122°28′18″W / 37.782321°N 122.47161137°W / 37.782321; -122.47161137 The Internet Archive is an American digital library with the stated mission of "universal access to all knowledge".[notes 2][notes 3] It provides free public access to collections of digitized materials, including websites, software applications/games, music, movies/videos, moving images, and millions of books. In addition to its archiving function, the Archive is an activist organization, advocating a free and open Internet. As of April 2021, the Internet Archive holds over 30 million books and texts, 8.9 million movies, videos and TV shows, 649,000 software programs, 13,225,000 audio files, 3.8 million images, and 580 billion web pages in the Wayback Machine. The Internet Archive allows the public to upload and download digital material to its data cluster, but the bulk of its data is collected automatically by its web crawlers, which work to preserve as much of the public web as possible. Its web archive, the Wayback Machine, contains hundreds of billions of web captures.[notes 4] The Archive also oversees one of the world's largest book digitization projects.
  • 13.4K
  • 18 Oct 2022
Topic Review
Dialysis (Biochemistry)
In biochemistry, dialysis is the process of separating molecules in solution by the difference in their rates of diffusion through a semipermeable membrane, such as dialysis tubing. Dialysis is a common laboratory technique that operates on the same principle as medical dialysis. In the context of life science research, the most common application of dialysis is for the removal of unwanted small molecules such as salts, reducing agents, or dyes from larger macromolecules such as proteins, DNA, or polysaccharides. Dialysis is also commonly used for buffer exchange and drug binding studies. The concept of dialysis was introduced in 1861 by the Scottish chemist Thomas Graham. He used this technique to separate sucrose (small molecule) and gum Arabic solutes (large molecule) in aqueous solution. He called the diffusible solutes crystalloids and those that would not pass the membrane colloids. From this concept dialysis can be defined as a spontaneous separation process of suspended colloidal particles from dissolved ions or molecules of small dimensions through a semi permeable membrane. Most common dialysis membrane are made of cellulose, modified cellulose or synthetic polymer (cellulose acetate or nitrocellulose).
  • 13.4K
  • 07 Nov 2022
Topic Review
Data Envelopment Analysis (DEA)
Data Envelopment Analysis (DEA) is a non-parametric methodology for measuring the efficiency of Decision Making Units (DMUs) using multiple inputs to outputs configurations. This is the most commonly used tool for frontier estimations in assessments of productivity and efficiency applied to all fields of economic activities.
  • 13.4K
  • 28 Jan 2022
Biography
Krist Novoselic
Krist Anthony Novoselic (Croatian: Krist Novoselić; born May 16, 1965) is an American musician and political activist, and was the bassist and founding member of the grunge band Nirvana alongside guitarist and lead singer Kurt Cobain.[1][2] Nirvana achieved massive success, earning multiple gold and platinum awards and touring around the world at sold-out shows.[3] After Nirvana disbanded foll
  • 13.4K
  • 22 Nov 2022
Topic Review
Generations of Glucose Biosensors
Electrochemical glucose biosensors are widely applied for glucose monitoring due to their unbeatable sensitivity, selectivity, and simplicity. In general, there are four primary generations of glucose biosensor, which are classified according to the electron transfer mechanism. Three generations represent the enzymatic glucose biosensor, and one generation represents the non-enzymatic glucose biosensor.
  • 13.4K
  • 14 Dec 2022
Topic Review
Doubling Time
The doubling time is time it takes for a population to double in size/value. It is applied to population growth, inflation, resource extraction, consumption of goods, compound interest, the volume of malignant tumours, and many other things that tend to grow over time. When the relative growth rate (not the absolute growth rate) is constant, the quantity undergoes exponential growth and has a constant doubling time or period, which can be calculated directly from the growth rate. This time can be calculated by dividing the natural logarithm of 2 by the exponent of growth, or approximated by dividing 70 by the percentage growth rate (more roughly but roundly, dividing 72; see the rule of 72 for details and derivatiatives of this formula). The doubling time is a characteristic unit (a natural unit of scale) for the exponential growth equation, and its converse for exponential decay is the half-life. For example, given Canada's net population growth of 0.9% in the year 2006, dividing 70 by 0.9 gives an approximate doubling time of 78 years. Thus if the growth rate remains constant, Canada's population would double from its 2006 figure of 33 million to 66 million by 2084.
  • 13.4K
  • 28 Nov 2022
Topic Review
Toxic Ingredients in Skin Lightening Cosmetics
Skin lightening is defined as "the practice of using chemicals or any other product with depigmenting potential in an attempt to lighten skin tone or improve the complexion; these goals are achieved by decreasing the concentration of melanin to achieve a reduction in the physiological pigmentation of the skin". Products used to achieve this purpose are known as depigmenting, skin-lightening, skin-bleaching, skin-brightening or skin-evening agents. Skin-whitening products containing highly toxic active ingredients (in particular mercury derivatives, hydroquinone and corticosteroids) are easily found on the market; the use of these depigmenting agents can be followed by a variety of adverse effects, with very serious and sometimes fatal complications, and is currently an emerging health concern in many countries. 
  • 13.4K
  • 26 May 2022
Topic Review
List of Seaplanes and Amphibious Aircraft
The following is a list of seaplanes and amphibious aircraft, which includes floatplanes and flying boats, by country of origin. Seaplanes are any aircraft that has the capability of landing on water while amphibious aircraft are equipped with wheels to alight on land, as well as being able to land on the water. Flying boats rely on the fuselage or hull for buoyancy, while floatplanes rely on external pontoons or floats. Some experimental aircraft used specially designed skis to skim across the water but did not always have a corresponding ability to float. This list does not include ekranoplans, 'Wing-In-Ground-effect' (WIG), water-skimmers, wingships or similar vehicles reliant on ground effect.
  • 13.4K
  • 07 Nov 2022
Topic Review
Whataboutism
Whataboutism, also known as whataboutery, is a variant of the tu quoque logical fallacy that attempts to discredit an opponent's position by charging them with hypocrisy without directly refuting or disproving their argument. According to Russian writer, chess grandmaster and political activist Garry Kasparov, "whataboutism" is a word that was coined to describe the frequent use of a rhetorical diversion by Soviet apologists and dictators, who would counter charges of their oppression, "massacres, gulags, and forced deportations" by invoking American slavery, racism, lynchings, etc. Whataboutism has been used by other politicians and countries as well. Whataboutism is particularly associated with Soviet and Russian propaganda. When criticisms were leveled at the Soviet Union during the Cold War, the Soviet response would often use "and what about you?" style by instancing of an event or situation in the Western world. The idea can be found in Russian language: while it utilizes phrase "Sam takoi" for direct tu quoque-like "you too"; it also has "Sam ne lutche" ("not better") phrase.
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  • 18 Nov 2022
Topic Review
God in Catholicism
God in Catholicism is the God of Abraham, Isaac, and Jacob. The Catholic Church believes that there is one true and living God, the Creator and Lord of Heaven and Earth. Despite other opinions, God is All-Perfect; this infinite Perfection is viewed, successively, under various aspects, each of which is treated as a separate perfection and characteristic inherent to the Divine Substance, or Essence. A certain group of these, of paramount import, is called the Divine Attributes. The position of the Catholic Church declared in the Fourth Lateran Council (1215), is again stated in the following pronouncement of the Vatican Council: "The Holy, Catholic, Apostolic, Roman Church believes and confesses that there is one, true, living God, Creator and Lord of heaven and earth, omnipotent, eternal, immense, incomprehensible, infinite in intellect and will, and in every perfection; who, although He is one, singular, altogether simple and unchangeable spiritual substance, must be proclaimed distinct in reality and essence from the world; most blessed in Himself and of Himself, and ineffably most high above all things which are or can be conceived outside Himself."
  • 13.4K
  • 09 Oct 2022
Topic Review
Pashtun Tahafuz Movement
The Pashtun Tahafuz Movement (Pashto: پښتون ژغورنې غورځنګ‎, Urdu: پشتون تحفظ تحریک‎; abbreviated PTM), or the Pashtun Protection Movement, is a social movement for Pashtun human rights based in Khyber Pakhtunkhwa and Balochistan. Formerly called the Mahsud Tahafuz (or Protection) Movement, it was founded in May 2014 by eight students at Gomal University, Dera Ismail Khan as an initiative for removing landmines from Waziristan and other parts of the former Federally Administered Tribal Areas, affected by the war in North-West Pakistan.
  • 13.4K
  • 24 Oct 2022
Topic Review
Doctor of Engineering
The Doctor of Engineering, or Engineering Doctorate, (abbreviated Eng.D., D.Eng., D.Engr., Dr.Eng., or Dr.-Ing.) is a degree awarded on the basis of advanced study and research in engineering and applied sciences. In most countries, it is a terminal research doctorate. A DEng/EngD is equivalent to a PhD in engineering, but different in that it has a solid industrial base and an additional taught element. The DEng/EngD along with the PhD represents the highest academic qualification in engineering, and the successful completion of either in engineering is generally required to gain employment as a full-time, tenure-track university professor or postdoctoral researcher in the field. Individuals can use the academic title doctor, which is often represented via the English honorific "Dr”. DEng/EngD candidates submit a significant project, typically referred to as a thesis or praxis, consisting of a body of original applied research that may be in principle worthy of publication in a peer-reviewed journal. Candidates must defend this work before a panel of expert examiners called a thesis or dissertation committee.
  • 13.4K
  • 20 Oct 2022
Topic Review
Exonym and Endonym
An exonym (from Greek: éxō, 'outer' + ónuma, 'name'; also known as xenonym) is a common, external name for a geographical place, group of people, individual person, or a language/dialect, that is used only outside that particular place, group, or linguistic community. Exonyms not only exist for historico-geographical reasons, but also in consideration of difficulties when pronouncing foreign words. An endonym (from Greek: éndon, 'inner'; also known as autonym) is a common, internal name for a geographical place, group of people, or a language/dialect, that is used only inside the place, group, or linguistic community in question; it is their self-designated name for themselves, their homeland, or their language.
  • 13.4K
  • 18 Oct 2022
Topic Review
HepG2 Cell Line
HepG2 is a hepatoblastoma cell line. It is used in a wide range of studies: a model of hepatoblastoma (HB) and hepatocellular carcinoma (HCC), cytotoxicity testing and the identification of drug metabolic pathways on the liver. 
  • 13.4K
  • 20 Dec 2021
Topic Review
Underwater Wireless Sensor Networks
The underwater wireless sensor network (UWSN) is a network used to perform monitoring of tasks over a specific region; it is equipped with smart sensors and vehicles that are adapted to communicate cooperatively through wireless connections [1]. The surface sink retrieves the data from sensor nodes. The sink node has a transceiver that can control acoustic signals received from underwater nodes. The transceiver also can transmit and receive long-range radio frequency signals for communication with the onshore station. The collected data are used locally or connected to another network for a particular purpose [2].
  • 13.3K
  • 26 Oct 2020
Topic Review
Chemical Affinity
In chemical physics and physical chemistry, chemical affinity is the electronic property by which dissimilar chemical species are capable of forming chemical compounds. Chemical affinity can also refer to the tendency of an atom or compound to combine by chemical reaction with atoms or compounds of unlike composition.
  • 13.3K
  • 20 Oct 2022
Topic Review
Cigarette Lighter Receptacle
The cigarette lighter receptacle (also called a cigar lighter receptacle or cigar lighter socket) in an automobile was initially designed to power an electrically heated cigarette lighter, but became a de facto standard DC connector to supply electrical power for portable accessories used in or near an automobile. While the cigarette lighter receptacle is a common feature of automobiles and trucks, as a DC power connector it has the disadvantages of bulkiness, relatively low current rating, and poor contact reliability. Examples of devices that can be operated from a cigarette lighter receptacle include lights, fans, beverage heating devices, and small motorized tools such as air compressors for inflating tires. Many portable electronic devices such as music players or mobile telephones use a cigarette lighter receptacle to recharge their internal batteries or to directly operate from the vehicle electrical system. Adapters for electronic devices may change voltage to be compatible with the supplied device. Devices that require alternating-current mains electricity can be operated with a plug-in inverter. Automobiles may provide several 12 V receptacles that are intended only to operate electrical accessories, and which cannot be used with a cigarette lighter. Car manufacturers may offer a cigarette lighter only as an optional extra-cost accessory. Usually, only one 12 V receptacle near the driver will be able to accommodate an actual cigarette lighter, with other receptacles designated as "12 V auxiliary power outlets" which are not physically able to power a lighter.
  • 13.3K
  • 24 Oct 2022
Topic Review
Essential Trace Elements
Trace elements produce double-edged effects on the lives of animals and particularly of humans. On one hand, these elements represent potentially toxic agents; on the other hand, they are essentially needed to support growth and development and confer protection against disease. The amount taken up and the accumulation in human tissues decisively control whether the exerted effects are toxic or beneficial. This entry provides a brief description of some toxic, likely essential and essential elements and their influence on human health.
  • 13.3K
  • 20 Aug 2020
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