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Gottlob Frege
Friedrich Ludwig Gottlob Frege (/ˈfreɪɡə/; German: [ˈɡɔtloːp ˈfreːɡə]; 8 November 1848 – 26 July 1925) was a German philosopher, logician, and mathematician. He worked as a mathematics professor at the University of Jena, and is understood by many to be the father of analytic philosophy, concentrating on the philosophy of language, logic, and mathematics. Though he was largely ignored during his lifetime, Giuseppe Peano (1858–1932) and Bertrand Russell (1872–1970) introduced his work to later generations of philosophers. His contributions include the development of modern logic in the Begriffsschrift and work in the foundations of mathematics. His book the Foundations of Arithmetic is the seminal text of the logicist project, and is cited by Michael Dummett as where to pinpoint the linguistic turn. His philosophical papers "On Sense and Reference" and "The Thought" are also widely cited. The former argues for two different types of meaning and descriptivism. In Foundations and "The Thought", Frege argues for Platonism against psychologism or formalism, concerning numbers and propositions respectively. Russell's paradox undermined the logicist project by showing Frege's Basic Law V in the Foundations to be false.
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  • 29 Sep 2022
Topic Review
Secure Shell Protocol
The Secure Shell Protocol (SSH) is a cryptographic network protocol for operating network services securely over an unsecured network. Typical applications include remote command-line, login, and remote command execution, but any network service can be secured with SSH. SSH provides a secure channel over an unsecured network by using a client–server architecture, connecting an SSH client application with an SSH server. The protocol specification distinguishes between two major versions, referred to as SSH-1 and SSH-2. The standard TCP port for SSH is 22. SSH is generally used to access Unix-like operating systems, but it can also be used on Microsoft Windows. Windows 10 uses OpenSSH as its default SSH client and SSH server. SSH was designed as a replacement for Telnet and for unsecured remote shell protocols such as the Berkeley rsh and the related rlogin and rexec protocols. Those protocols send information, notably passwords, in plaintext, rendering them susceptible to interception and disclosure using packet analysis. The encryption used by SSH is intended to provide confidentiality and integrity of data over an unsecured network, such as the Internet.
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  • 29 Sep 2022
Topic Review
Chital
The chital (/tʃiːtəl/; Axis axis), also known as spotted deer, chital deer, and axis deer, is a species of deer that is native to the Indian subcontinent. It was first described by German naturalist Johann Christian Polycarp Erxleben in 1777. A moderate-sized deer, male chital reach nearly 90 cm (35 in) and females 70 cm (28 in) at the shoulder. While males weigh 30–75 kg (66–165 lb), the lighter females weigh 25–45 kg (55–99 lb). It is sexually dimorphic; males are larger than females, and antlers are present only on males. The upper parts are golden to rufous, completely covered in white spots. The abdomen, rump, throat, insides of legs, ears, and tail are all white. The antlers, three-pronged, are nearly 1 m (3.3 ft) long.
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  • 29 Sep 2022
Topic Review
Seismic Array
A seismic array is a system of linked seismometers arranged in a regular geometric pattern (cross, circle, rectangular etc.) to increase sensitivity to earthquake and explosion detection. A seismic array differs from a local network of seismic stations mainly by the techniques used for data analysis. The data from a seismic array is obtained using special digital signal processing techniques such as beamforming, which suppress noises and thus enhance the signal-to-noise ratio (SNR). The earliest seismic arrays were built in the 1950s in order to improve the detection of nuclear tests worldwide. Many of these deployed arrays were classified until the 1990s. Today they become part of the IMS as primary or auxiliary stations. Seismic arrays are not only used to monitor earthquakes and nuclear tests, but also used as a tool for investigating nature and source regions of microseisms as well as locating and tracking volcanic tremor and analyzing complex seismic wave-field properties in volcanic areas.
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Topic Review
SARS-related Coronavirus
Severe acute respiratory syndrome–related coronavirus (SARS-CoV or SARSr-CoV)[note 1] is a species of coronavirus that infects humans, bats and certain other mammals. It is an enveloped positive-sense single-stranded RNA virus that enters its host cell by binding to the angiotensin-converting enzyme 2 (ACE2) receptor. It is a member of the genus Betacoronavirus and subgenus Sarbecovirus. Two strains of the virus have caused outbreaks of severe respiratory diseases in humans: severe acute respiratory syndrome coronavirus (SARS-CoV or SARS-CoV-1), which caused the 2002–2004 outbreak of severe acute respiratory syndrome (SARS), and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which is causing the 2019–20 pandemic of coronavirus disease 2019 (COVID-19). There are hundreds of other strains of SARS-CoV, all of which are only known to infect non-human species: bats are a major reservoir of many strains of SARS-related coronaviruses, and several strains have been identified in palm civets, which were likely ancestors of SARS-CoV. The SARS-related coronavirus was one of several viruses identified by the World Health Organization (WHO) in 2016 as a likely cause of a future epidemic in a new plan developed after the Ebola epidemic for urgent research and development before and during an epidemic towards diagnostic tests, vaccines and medicines. The prediction came to pass with the COVID-19 pandemic.
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  • 29 Sep 2022
Topic Review
Tier-Scalable Reconnaissance
Tier-Scalable Reconnaissance is the term for an approach to deploying and controlling vehicles in multiple areas of interest, such as in the exploration of planets or diverse regions on Earth. It is not a rigid or fixed paradigm, but is infinitely extensible. It uses hierarchical levels of oversight called tiers, each tier commanding or controlling the vehicles within the tier beneath it. The size of each tier can be scaled from one to many vehicles.
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  • 09 Oct 2022
Topic Review
Tumor Necrosis Factor Alpha
Tumor necrosis factor (TNF, cachexin, or cachectin; once named as tumor necrosis factor alpha or TNFα) is a cell signaling protein (cytokine) involved in systemic inflammation and is one of the cytokines that make up the acute phase reaction. It is produced chiefly by activated macrophages, although it can be produced by many other cell types such as CD4+ lymphocytes, NK cells, neutrophils, mast cells, eosinophils, and neurons. TNF is a member of the TNF superfamily, consisting of various transmembrane proteins with a homologous TNF domain. The primary role of TNF is in the regulation of immune cells. TNF, being an endogenous pyrogen, is able to induce fever, apoptotic cell death, cachexia, inflammation and to inhibit tumorigenesis and viral replication and respond to sepsis via IL1- & IL6-producing cells. Dysregulation of TNF production has been implicated in a variety of human diseases including Alzheimer's disease, cancer, major depression, psoriasis and inflammatory bowel disease (IBD). Though controversial, studies of depression and IBD are currently being linked to increased levels of TNF. Recombinant TNF is used as an immunostimulant under the INN tasonermin. TNF can be produced ectopically in the setting of malignancy and parallels parathyroid hormone both in causing secondary hypercalcemia and in the cancers with which excessive production is associated.
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  • 10 Oct 2022
Topic Review
Alpha Thalassemia Abnormal Morphogenesis
Alpha Thalassemia-Abnormal Morphogensis is a group of blood disorders that affect the way the body makes hemoglobin. Hemoglobin is a protein found in red blood cells that carries oxygen throughout the body. It's made up of alpha globin and beta globin. Normally each person has four genes for alpha globin, Alpha thalassemia happens when one or more of the genes that control the making of alpha globin is absent or defective. It can cause anemia ranging from mild to severe. Also causing Genital abnormalities and terminal transverse limb defectiveness which is why it is called abnormal morphogenesis. This is most commonly found in people of African, Middle Eastern, Chinese, Southeast Asian and occasionally, Mediterranean descent.
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Topic Review
X Display Manager (Program Type)
In the X Window System, an X display manager is a graphical login manager which starts a session on an X server from the same or another computer. A display manager presents the user with a login screen. A session starts when a user successfully enters a valid combination of username and password. When the display manager runs on the user's computer, it starts the X server before presenting the user the login screen, optionally repeating when the user logs out. In this condition, the DM realizes in the X Window System the functionality of getty and login on character-mode terminals. When the display manager runs on a remote computer, it acts like a telnet server, requesting username and password and starting a remote session. X11 Release 3 introduced display managers in October 1988 with the aim of supporting the standalone X terminals, just coming onto the market. Various display managers continue in routine use to provide a graphical login prompt on standalone computer workstations running X. X11R4 introduced the X Display Manager Control Protocol (XDMCP) in December 1989 to fix problems in the X11R3 implementation.
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Topic Review
Proto-Hlai
Proto-Hlai is the reconstructed ancestor of the Hlai languages. Proto-Hlai reconstructions include those of Matisoff (1988), Thurgood (1991), Wu (2000), Ostapirat (2004), and Norquest (2007).
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