In toxicology, the median lethal dose, LD50 (abbreviation for "lethal dose, 50%"), LC50 (lethal concentration, 50%) or LCt50 is a toxic unit that measures the lethal dose of a given substance. The value of LD50 for a substance is the dose required to kill half the members of a tested population after a specified test duration. LD50 figures are frequently used as a general indicator of a substance's acute toxicity. A lower LD50 is indicative of higher toxicity.
Air Canada is the flag carrier and the largest airline of Canada, by size and passengers carried. Air Canada is headquartered in the borough of Saint-Laurent, Montreal, Quebec. The airline, founded in 1937, provides scheduled and charter air transport for passengers and cargo to 222 destinations worldwide. It is a founding member of the Star Alliance. Air Canada's major hubs are at Toronto Pearson International Airport (YYZ), Montréal–Trudeau International Airport (YUL), and Vancouver International Airport (YVR).
Vueling S.A. is a Spanish low-cost airline based at Viladecans in Greater Barcelona with hubs at Barcelona–El Prat Airport (main), Paris-Orly Airport in Paris, France, Amsterdam Schiphol Airport in Amsterdam, The Netherlands and Leonardo da Vinci–Fiumicino Airport in Rome, Italy (secondary). It is the largest airline in Spain, measured by fleet size and number of destinations. As of 2021, Vueling serves 122 destinations in Africa, Asia, Europe and the Middle East, and carried more than 34 million passengers in 2019. Since 2013, it has been an operating company of International Airlines Group, the parent company of British Airways, Iberia and Aer Lingus.
Google Scholar is a freely accessible web search engine that indexes the full text or metadata of scholarly literature across an array of publishing formats and disciplines. Released in beta in November 2004, the Google Scholar index includes peer-reviewed online academic journals and books, conference papers, theses and dissertations, preprints, abstracts, technical reports, and other scholarly literature, including court opinions and patents.
PrimeGrid is a volunteer computing project that searches for very large prime numbers whilst also aiming to solve long-standing mathematical conjectures. It uses the Berkeley Open Infrastructure for Network Computing (BOINC) platform. PrimeGrid offers a number of subprojects for prime-number sieving and discovery. Some of these are available through the BOINC client, others through the PRPNet client. Some of the work is manual, i.e. it requires manually starting work units and uploading results. Different subprojects may run on different operating systems, and may have executables for CPUs, GPUs, or both; while running the Lucas–Lehmer–Riesel test, CPUs with Advanced Vector Extensions and Fused Multiply-Add instruction sets will yield the fastest results for non-GPU accelerated workloads.
As of the year 2023, Christianity had approximately 2.4 billion adherents and is the largest religion by population. According to a PEW estimation in 2020, Christians made up to 2.38 billion of the worldwide population of about 8 billion people. It represents nearly one-third of the world's population and is the largest religion in the world, with the three largest groups of Christians being the Catholic Church, Protestantism, and the Eastern Orthodox Church. The largest Christian denomination is the Catholic Church, with 1.3 billion baptized members. The second largest Christian branch is either Protestantism, or the Eastern Orthodox Church.
The 5000 metres or 5000-metre run is a common long-distance running event in track and field, approximately equivalent to 3 miles 188 yards or 16,404 feet 2 inches. It is one of the track events in the Olympic Games and the World Championships in Athletics, run over 12+1⁄2 laps of a standard 400 m track, or 25 laps on an indoor 200 m track. The same distance in road running is called a 5K run; referring to the distance in metres rather than kilometres serves to disambiguate the two events. The 5000 m has been present on the Olympic programme since 1912 for men and since 1996 for women. Prior to 1996, women had competed in an Olympic 3000 metres race since 1984. The 5000 m has been held at each of the World Championships in Athletics in men's competition and since 1995 in women's.
The IBSA World Games or World Blind Games are an international multi-sport event, occurring every four years, organized by the International Blind Sports Federation (IBSA). The events enable blind and partially sighted athletes to compete in a number of sports. The first event took place at Madrid, Spain in 1998.
C++20 is a version of the ISO/IEC 14882 standard for the C++ programming language. C++20 replaced the prior version of the C++ standard, called C++17, and was later replaced by C++23. The standard was technically finalized by WG21 at the meeting in Prague in February 2020, had its final draft version announced in March 2020, was approved on 4 September 2020, and published in December 2020.
The men's high jump event at the 2017 Summer Universiade was held on 23 and 25 August in Taipei City.
