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Topic Review
Aero L-159 Alca
The Aero L-159 ALCA[nb 1] is a subsonic light combat aircraft and advanced trainer developed in the single-seat L-159A and two-seat L-159B versions respectively, produced in the Czech Republic by Aero Vodochody. In 2003, the Czech Air Force fleet of 72 L-159A aircraft was reduced to 24 due to budget constraints. After several years of storage, the government has re-sold most of the redundant aircraft to both military and civilian operators, namely the Iraqi Air Force and Draken International. The L-159 has seen active combat use by the Iraqi Air Force against ISIS. In Draken's service, the L-159 (colloquially known as "Honey Badger") has been employed as an aggressor aircraft. Since 2007, six L-159A aircraft have been rebuilt into T1 trainer derivatives. In 2017, Aero Vodochody unveiled a newly built L-159T1 for the Iraqi Air Force while the Czech Air Force is set to acquire L-159T2 two-seaters.
  • 6.7K
  • 29 Nov 2022
Topic Review
Eurostar
Eurostar is an international high-speed rail service connecting the United Kingdom with France , Belgium and the Netherlands. Most Eurostar trains travel through the Channel Tunnel between the United Kingdom and France, owned and operated separately by Getlink. The London terminus is London St Pancras International; the other British calling points are Ebbsfleet International and Ashford International in Kent. Intermediate calling points in France are Calais-Fréthun and Lille-Europe. Trains to Paris terminate at Gare du Nord. Trains to Belgium and the Netherlands serve Brussels-South and Rotterdam Centraal, before terminating at Amsterdam Centraal. Additionally, in France there are direct services from London to Marne-la-Vallée–Chessy (Disneyland Paris) and seasonal direct services to southern France (Lyon, Avignon and Marseille) in summer, and to the French Alps in winter. The service is operated by 11 Class 373/1 trainsets, each with 18 coaches, and 17 Class 374 trainsets, each with 16 coaches. The trains run at up to 320 kilometers per hour (200 mph) on high-speed lines. The LGV Nord high-speed line in France opened before Eurostar services began in 1994, and newer lines enabling faster journeys were added later: HSL 1 in Belgium and High Speed 1 in south-east England. The French and Belgian parts of the network are shared with Paris–Brussels Thalys services and TGV trains. Eurostar is operated by Eurostar International Limited (EIL), jointly owned by SNCF, the national railway of France (55%), investment firms (40%), and the National Railway Company of Belgium (5%).
  • 6.7K
  • 20 Nov 2022
Topic Review
Convolutional Neural Network in the Medical Imaging
Convolutional Neural Networks (CNN), commonly known as ConvNet, is one of the common types of Artificial Neural Network (ANN) that comes under the supervised method category. This method is known for its ability to discover and interpret patterns. This pattern detection brings up the usefulness of CNN for image analysis. 
  • 6.7K
  • 10 Apr 2023
Topic Review
Artificial Intelligence in Archaeology
Artificial Intelligence (AI), due to its increasingly powerful predictive capabilities, is showing an increasing trend in attracting widespread interest in many sciences. Archaeologists now can more fully exploit the knowledge from an extensive amount of archaeological data with the use of artificial intelligence in such a way as to make decisions related to appropriate strategies for the preservation and protection of archaeological elements, as well as to decide on the most ideal point excavation in a complex cultural landscape. 
  • 6.7K
  • 30 Nov 2022
Topic Review
List of Mergers and Acquisitions by IBM
IBM has undergone a large number of mergers and acquisitions during a corporate history lasting over a century; the company has also produced a number of spinoffs during that time. The acquisition date listed is the date of the agreement between IBM and the subject of the acquisition. The value of each acquisition is listed in USD because IBM is based in the United States . If the value of an acquisition is not listed, then it is undisclosed. Many of the companies listed in this article had subsidiaries of their own who had subsidiaries who ... For examples, see Pugh's book Building IBM, page 26.
  • 6.7K
  • 17 Oct 2022
Topic Review
Starship (Spacecraft)
Starship is the fully reusable second stage and space vehicle of the SpaceX BFR "Super Heavy" rocket currently under development by SpaceX. It is a long-duration cargo- and passenger-carrying spacecraft that also serves as the BFR launch vehicle second stage and integrated payload section. Three 9-meter (30 ft)-diameter stainless steel Starship test articles are being built, and one had already begun integrated system testing by March 2019. The Starship test flight rocket—Starhopper—will be used for initial integrated testing of the Raptor rocket engine with a flight-capable propellant structure as well as for low-altitude, low-velocity flight testing of launches and landings. It began hotfire testing in April 2019. Two additional test articles, Starship orbital prototypes, are being built by competing teams in South Texas and along the space coast of Florida. They are planned to be used after mid-2019 for high-altitude, high-velocity testing. Integrated system testing of Starhopper, including the first flight test, began in April 2019. SpaceX is planning to launch commercial payloads using Starship no earlier than 2021.
  • 6.7K
  • 21 Oct 2022
Topic Review
Support Needs in Intellectual Disability
“Support needs” is a psychological construct referring to the pattern and intensity of supports necessary for a person to participate in activities linked with normative human functioning.
  • 6.7K
  • 11 Jan 2021
Topic Review
Word Lists by Frequency
Word lists by frequency are lists of a language's words grouped by frequency of occurrence within some given text corpus, either by levels or as a ranked list, serving the purpose of vocabulary acquisition. A word list by frequency "provides a rational basis for making sure that learners get the best return for their vocabulary learning effort" (Nation 1997), but is mainly intended for course writers, not directly for learners. Frequency lists are also made for lexicographical purposes, serving as a sort of checklist to ensure that common words are not left out. Some major pitfalls are the corpus content, the corpus register, and the definition of "word". While word counting is a thousand years old, with still gigantic analysis done by hand in the mid-20th century, natural language electronic processing of large corpora such as movie subtitles (SUBTLEX megastudy) has accelerated the research field. In computational linguistics, a frequency list is a sorted list of words (word types) together with their frequency, where frequency here usually means the number of occurrences in a given corpus, from which the rank can be derived as the position in the list.
  • 6.6K
  • 29 Nov 2022
Topic Review
First Generation of Intellectual Movements in Iran
First Generation of Intellectual movements in Iran (Persian: نسل اول جنبش های روشنفکری در ایران‎, romanized: Nasl-e Aval-e Jonbesh Hay-e Roshan Fekri dar Iran) or Iranian Enlightenment (Persian: روشنگری ایرانی‎, romanized: Roshangari-e Irani) was a period in the mid-19th- to early-20th- century in Iran, which was accompanied by new ideas in the traditional Iranian society. During the rule of the Qajar dynasty, and especially after the defeat of Iran, in the war with the Russian Empire, due to cultural exchanges, new ideas were formed among the educated class of Iran. This military defeat also encouraged the Qajar commanders to overcome the backwardness. The establishment of Dar ul-Fonun, the first modern university in Iran and the arrival of foreign professors, caused the thoughts of European thinkers to enter Iran, followed by the first signs of enlightenment and intellectual movements in Iran. During this period, intellectual groups were formed in Secret societies and secret associations. Among these Secret societies, we can mention Mirza Malkam Khan's "Faramosh Khaneh" (based on Masonic lodges), Anjoman-e Bagh-e Meykadeh, Society of Humanity and Mokhadarat Vatan Association. These groups spread their ideas by distributing leaflets and newspapers. These secret societies stressed the need to reform the land and administrative system and reduce the role of the clergy in society, as well as to limit the rulers within the framework of the law. Iranian thinkers based their work on confronting religious traditions, they were confronted with Shia Islam, which on the one hand was mixed with superstitions, and on the other hand, the strictness and intellectual prejudice of some religious people caused intellectual-scientific decline. Among the thinkers of this period were Mirza Malkam Khan, Mirza Abdul'Rahim Talibov, Mirza Fatali Akhundov, Iraj Mirza, Mirzadeh Eshghi, Aref Qazvini, Mirza Hassan Roshdieh, Mirza Aqa Khan Kermani, Hassan Taqizadeh, Amir Kabir and Haydar Khan Amo-oghli. Most of these intellectuals expressed their thoughts through poetry and fiction, simple stories and parables that were easier for people to understand helped to spread Enlightenment throughout Iran. The first generation of intellectuals in Iran went beyond the borders of this country and influenced neighboring countries such as Afghanistan and the Arab world such as Egypt. People like Jamāl al-Dīn al-Afghānī collaborated with most of the great thinkers of this period from Iran.
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  • 05 Dec 2022
Topic Review
Role of Chloroplast Gene Expression
 Chloroplasts are plant organelles that carry out photosynthesis, produce various metabolites, and sense changes in the external environment. Given their endosymbiotic origin, chloroplasts have retained independent genomes and gene-expression machinery. Most genes from the prokaryotic ancestors of chloroplasts were transferred into the nucleus over the course of evolution. However, the importance of chloroplast gene expression in environmental stress responses have recently become more apparent. Here, we discuss the emerging roles of the distinct chloroplast gene expression processes in plant responses to environmental stresses. For example, the transcription and translation of psbA play an important role in high-light stress responses. A better understanding of the connection between chloroplast gene expression and environmental stress responses is crucial for breeding stress-tolerant crops better able to cope with the rapidly changing environment. Chloroplasts are plant organelles that carry out photosynthesis, produce various metabolites, and sense changes in the external environment. Given their endosymbiotic origin, chloroplasts have retained independent genomes and gene-expression machinery. Most genes from the prokaryotic ancestors of chloroplasts were transferred into the nucleus over the course of evolution. However, the importance of chloroplast gene expression in environmental stress responses have recently become more apparent.
  • 6.6K
  • 02 Sep 2020
Topic Review
Social Inertia
Social inertia refers to the tendency of social systems to resist change and maintain their existing state of equilibrium. It encompasses the collective reluctance or resistance within a society to adopt new ideas, practices, or norms, even in the face of external pressures or opportunities for change. Social inertia can arise from various factors, including cultural traditions, institutional structures, and psychological biases, and it often presents challenges for efforts to enact social reform or innovation.
  • 6.6K
  • 08 Feb 2024
Topic Review
Colorectal Cancer Development
Colorectal cancer (CRC) is a disorder that occurs exclusively in the colon or rectum and is caused by the colon’s aberrant proliferation of glandular epithelial cells.
  • 6.6K
  • 19 Apr 2022
Topic Review
Vectors in Gene Therapy for Pulmonary Diseases
Over the past decades, a better understanding of the genetic and molecular alterations underlying several respiratory diseases has encouraged the development of new therapeutic strategies. Gene therapy offers new therapeutic alternatives for inherited and acquired diseases by delivering exogenous genetic materials into cells or tissues to restore physiological protein expression and/or activity.
  • 6.6K
  • 16 Mar 2022
Topic Review
Reverse Water Gas Shift Reaction
The catalytic conversion of CO2 to CO by the reverse water gas shift (RWGS) reaction followed by well-established synthesis gas conversion technologies could be a practical technique to convert CO2 to valuable chemicals and fuels in industrial settings. For catalyst developers, prevention of side reactions like methanation, low-temperature activity, and selectivity enhancements for the RWGS reaction are crucial concerns. Cerium oxide (ceria, CeO2) has received considerable attention due to its exceptional physical and chemical properties. 
  • 6.6K
  • 09 Oct 2022
Topic Review
Supercritical Water Gasification (SCWG)
Gasification with supercritical water (SCWG) is a thermochemical process which, exploiting the properties of supercritical water (374.1 °C and 22.1 MPa ), allows to obtain a syngas rich in hydrogen. Both biomass and waste plastic can be used as feedstock.
  • 6.6K
  • 18 Sep 2020
Topic Review
Citrus limon (Lemon) Phenomenon
Citrus limon (lemon) is a species with valuable pharmaceutical, cosmetic and culinary (healthy food) properties. The valuable biological activity of C. limon is determined by its high content of phenolic compounds, mainly flavonoids (e.g., diosmin, hesperidin, limocitrin) and phenolic acids (e.g., ferulic, synapic, p-hydroxybenzoic acids). The essential oil is rich in bioactive monoterpenoids such as D-limonene, β-pinene, γ-terpinene. Recently scientifically proven therapeutic activities of C. limon include anti-inflammatory, antimicrobial, anticancer and antiparasitic activities. In view of beneficial properties C. limon  is also used in the food industry and cosmetology. Attention should be pay on safety of use and potential phototoxicity of this raw materials.
  • 6.6K
  • 30 Oct 2020
Topic Review
Instability of Peptide and Possible Causes of Degradation
Peptides are different from proteins. Although both are composed of amino acids, peptides are smaller molecules comprised of two or more amino acids linked by peptide bonds, while proteins are long chains of amino acids that may have a much larger number of amino acids. Peptide stability in aqueous solutions is critical when developing parenteral formulations, as the potency of a peptide is often compromised due to chemical or physical degradation pathways.
  • 6.6K
  • 29 Mar 2023
Topic Review
Frost Diagram
A Frost diagram or Frost–Ebsworth diagram is a type of graph used by inorganic chemists in electrochemistry to illustrate the relative stability of a number of different oxidation states of a particular substance. The graph illustrates the free energy vs oxidation state of a chemical species. This effect is dependent on pH, so this parameter also must be included. The free energy is determined by the oxidation–reduction half-reactions. The Frost diagram allows easier comprehension of these reduction potentials than the earlier-designed Latimer diagram, because the “lack of additivity of potentials” was confusing. The free energy ΔG° is related to reduction potential E in the graph by given formula: ΔG° = −nFE° or nE° = −ΔG°/F, where n is the number of transferred electrons, and F is Faraday constant (F = 96,485 J/(V·mol)). The Frost diagram is named after Arthur Atwater Frost (de), who originally created it as a way to "show both free energy and oxidation potential data conveniently" in a 1951 paper.
  • 6.6K
  • 01 Dec 2022
Topic Review
Different Types of Adipocytes
Adipose tissue resides in specific depots scattered in peripheral or deeper locations all over the body and it enwraps most of the organs. This tissue is always in a dynamic evolution as it must adapt to the metabolic demand and constraints. It exhibits also endocrine functions important to regulate energy homeostasis. This complex organ is composed of depots able to produce opposite functions to monitor energy: the so called white adipose tissue acts to store energy as triglycerides preventing ectopic fat deposition while the brown adipose depots dissipate it. It is composed of many cell types. Different types of adipocytes constitute the mature cells specialized to store or burn energy. Immature adipose progenitors (AP) presenting stem cells properties contribute not only to the maintenance but also to the expansion of this tissue as observed in overweight or obese individuals.
  • 6.6K
  • 28 Apr 2021
Topic Review
Amen
Amen (/ˌɑːˈmɛn/, /ˌeɪˈmɛn/)[lower-alpha 1] (Hebrew אָמֵן, Greek ἀμήν, Arabic آمِينَ, Amharic አሜን) is a declaration of affirmation first found in the Hebrew Bible and subsequently in the New Testament. It is used in Jewish, Christian and Muslim worship as a concluding word or response to prayers. Common English translations of the word amen include "verily", "truly", and “so be it”. It can also be used colloquially to express strong agreement, as in, amen to that.
  • 6.6K
  • 27 Oct 2022
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