click links in text for more info
SUMMARY / RELATED TOPICS

Astrometry

Astrometry is the branch of astronomy that involves precise measurements of the positions and movements of stars and other celestial bodies. The information obtained by astrometric measurements provides information on the kinematics and physical origin of the Solar System and our galaxy, the Milky Way; the history of astrometry is linked to the history of star catalogues, which gave astronomers reference points for objects in the sky so they could track their movements. This can be dated back to Hipparchus, who around 190 BC used the catalogue of his predecessors Timocharis and Aristillus to discover Earth's precession. In doing so, he developed the brightness scale still in use today. Hipparchus compiled a catalogue with their positions. Hipparchus's successor, included a catalogue of 1,022 stars in his work the Almagest, giving their location and brightness. In the 10th century, Abd al-Rahman al-Sufi carried out observations on the stars and described their positions and star color. Ibn Yunus observed more than 10,000 entries for the Sun's position for many years using a large astrolabe with a diameter of nearly 1.4 metres.

His observations on eclipses were still used centuries in Simon Newcomb's investigations on the motion of the Moon, while his other observations of the motions of the planets Jupiter and Saturn inspired Laplace's Obliquity of the Ecliptic and Inequalities of Jupiter and Saturn. In the 15th century, the Timurid astronomer Ulugh Beg compiled the Zij-i-Sultani, in which he catalogued 1,019 stars. Like the earlier catalogs of Hipparchus and Ptolemy, Ulugh Beg's catalogue is estimated to have been precise to within 20 minutes of arc. In the 16th century, Tycho Brahe used improved instruments, including large mural instruments, to measure star positions more than with a precision of 15–35 arcsec. Taqi al-Din measured the right ascension of the stars at the Constantinople Observatory of Taqi ad-Din using the "observational clock" he invented; when telescopes became commonplace, setting circles sped measurements James Bradley first tried to measure stellar parallaxes in 1729. The stellar movement proved too insignificant for his telescope, but he instead discovered the aberration of light and the nutation of the Earth's axis.

His cataloguing of 3222 stars was refined in 1807 by Friedrich Bessel, the father of modern astrometry. He made the first measurement of stellar parallax: 0.3 arcsec for the binary star 61 Cygni. Being difficult to measure, only about 60 stellar parallaxes had been obtained by the end of the 19th century by use of the filar micrometer. Astrographs using astronomical photographic plates sped the process in the early 20th century. Automated plate-measuring machines and more sophisticated computer technology of the 1960s allowed more efficient compilation of star catalogues. In the 1980s, charge-coupled devices replaced photographic plates and reduced optical uncertainties to one milliarcsecond; this technology made astrometry less expensive. In 1989, the European Space Agency's Hipparcos satellite took astrometry into orbit, where it could be less affected by mechanical forces of the Earth and optical distortions from its atmosphere. Operated from 1989 to 1993, Hipparcos measured large and small angles on the sky with much greater precision than any previous optical telescopes.

During its 4-year run, the positions and proper motions of 118,218 stars were determined with an unprecedented degree of accuracy. A new "Tycho catalog" drew together a database of 1,058,332 to within 20-30 mas. Additional catalogues were compiled for the 23,882 double/multiple stars and 11,597 variable stars analyzed during the Hipparcos mission. Today, the catalogue most used is USNO-B1.0, an all-sky catalogue that tracks proper motions, positions and other characteristics for over one billion stellar objects. During the past 50 years, 7,435 Schmidt camera plates were used to complete several sky surveys that make the data in USNO-B1.0 accurate to within 0.2 arcsec. Apart from the fundamental function of providing astronomers with a reference frame to report their observations in, astrometry is fundamental for fields like celestial mechanics, stellar dynamics and galactic astronomy. In observational astronomy, astrometric techniques help identify stellar objects by their unique motions, it is instrumental for keeping time, in that UTC is the atomic time synchronized to Earth's rotation by means of exact astronomical observations.

Astrometry is an important step in the cosmic distance ladder because it establishes parallax distance estimates for stars in the Milky Way. Astrometry has been used to support claims of extrasolar planet detection by measuring the displacement the proposed planets cause in their parent star's apparent position on the sky, due to their mutual orbit around the center of mass of the system. Astrometry is more accurate in space missions that are not affected by the distorting effects of the Earth's atmosphere. NASA's planned Space Interferometry Mission was to utilize astrometric techniques to detect terrestrial planets orbiting 200 or so of the nearest solar-type stars; the European Space Agency's Gaia Mission, launched in 2013, applies astrometric techniques in its stellar census. In addition to the detection of exoplanets, it can be used to determine their mass. Astrometric measurements are used by astrophysicists to constrain certain models in celestial mechanics. By measuring the velocities of pulsars, it is possible to put a limit on the asymmetry of supernova explosions.

A

Eryngium maritimum

Eryngium maritimum, the sea holly or seaside eryngo, is a species of Eryngium in the plant family Apiaceae and native to most European coastlines. It resembles a plume thistle in that its flower is burr-shaped, but the flowers are metallic blue rather than mauve. Protected from winds this dune plant grows to a height of 20 to 60 cm. Although widespread, it is considered endangered in many areas, such as Germany where its occurrence has been reduced throughout and has become locally extinct in several districts. In Elizabethan times in England, these plants were believed to be a strong aphrodisiac, they are named in a speech by Falstaff: Sea holly was nominated the 2002 County flower for the city of Liverpool. Asteroid 199194 Calcatreppola was named after this plant; the official naming citation was published by the Minor Planet Center on 25 September 2018. This article is based on a translation of an article from the German Wikipedia Plants for a Future—PFAF Plant Database: Eryngium maritimum Schutzstation-wattenmeer.de: Further information and images— Linnaeus.nrm.se.

Loraine Felix

Loraine Felix is a Swiss singer-songwriter. She was born in 1983, in Liege, where her parents were working at that moment; the family moved back to Geneva soon after that. Her educational background is in Arts, she attended different courses and workshops on music composition and lyricism in Paris with the famous songwriter Claude Lemesle. Since 2006, she has worked with the pianist from Tim Haller. Over her career she has performed in different regions in Switzerland and France and Canada, her first album, "Mine de rien" was released in 2009. It had a great reception by the media and public in the French-Swiss region, her second album "Au coin de l´oeil" was released in 2014. In 2007, she was awarded the public´s choice award in the "Voix de Fête" festival. In 2009, she represented Switzerland in the Canadian Festival « Du haut des airs » In 2010, she was part of the "rencontres d'Astaffort" created by Francis Cabrel She was awarded the 3rd price in the 2010 edition of the « La médaille d'or de la chanson » in Saignelégier, Switzerland.

In 2013, she took part in the "Pause Guitare" Festival, which included artists like Mika and Iggy Pop. In 2019, she released on youtube one of her new songs, "Autant de Prenoms" telling the story of the names that have marked her life in different ways. Https://www.lorainefelix.ch/

John Kessel

John Kessel is an American author of science fiction and fantasy. He is a prolific short story writer, the author of four solo novels, Good News From Outer Space, Corrupting Dr. Nice, The Moon and the Other, Pride and Prometheus, one novel, Freedom Beach in collaboration with his friend James Patrick Kelly. Kessel is married to author Therese Anne Fowler. Kessel obtained a B. A. in Physics and English from the University of Rochester in 1972, followed by a M. A. in English from University of Kansas in 1974, a Ph. D. in English from the University of Kansas in 1981, where he studied under science fiction writer and scholar James Gunn. Since 1982 Kessel has taught classes in American literature, science fiction and fiction writing at North Carolina State University, helped organize the MFA Creative Writing program at NCSU, serving as its first director. Kessel won a Nebula Award in 1982 for his novella "Another Orphan", in which the protagonist finds himself living inside the novel Moby-Dick, a second for his 2008 novelette "Pride and Prometheus", a story melding the tales of Jane Austen's Pride and Prejudice and Mary Shelley's Frankenstein.

This novelette won a 2009 Shirley Jackson Award. The intervening 26 years was the longest gap between competitive awards in Nebula history, his short story "Buffalo" won the Theodore Sturgeon Memorial Award and the Locus poll in 1992. His novella "Stories for Men" shared the 2002 James Tiptree, Jr. Award for science fiction dealing with gender issues with M. John Harrison's novel Light, he has been nominated three times for a World Fantasy Award: 1993 for the Meeting in Infinity collection, 1999 for the short fiction "Every Angel is Terrifying", 2009 for the short story "Pride and Prometheus". Kessel is a published science fiction and fantasy critic, his works of criticism include the 2004 essay on Orson Scott Card's novel Ender's Game, "Creating the Innocent Killer: Ender's Game and Morality". With Mark L. Van Name, Kessel created the Sycamore Hill Writer's Workshop. Kessel has edited, with Kelly, three collections of contemporary sf short stories, Feeling Very Strange: The Slipstream Anthology, Rewired: The Post-Cyberpunk Anthology, The Secret History of Science Fiction.

In 1994 his play Faustfeathers received the Paul Green Playwrights' Prize. In 2007 his story "A Clean Escape" was adapted by Sam Egan for ABC's science fiction anthology series Masters of Science Fiction. 1985 Freedom Beach 1989 Good News From Outer Space 1997 Corrupting Dr. Nice 2017 The Moon and the Other 2018 Pride and Prometheus 1989 Another Orphan 1986 A Clean Escape 1994 Faustfeathers 1992 Meeting in Infinity 1997 The Pure Product 2008 The Baum Plan for Financial Independence and Other Stories 1996 Intersections: The Sycamore Hill Anthology 2006 Feeling Very Strange: The Slipstream Anthology Features stories by Aimee Bender, Michael Chabon, Ted Chiang, Carol Emshwiller, Jeffrey Ford, Karen Joy Fowler, Theodora Goss, Jonathan Lethem, Kelly Link, M. Rickert, Benjamin Rosenbaum, George Saunders, Bruce Sterling, Jeff VanderMeer, Howard Waldrop 2007 Rewired: The Post-Cyberpunk Anthology 2009 The Secret History of Science Fiction 2011 Kafkaesque: Stories Inspired by Franz Kafka 2012 Nebula Awards Showcase 2012 (coedited with James Patrick Kelly 2012 Digital Rapture: The Singularity Anthology (coedited with James Patrick Kelly 1982 "Another Orphan" - Nebula Award Winner 1988 "Mrs. Shummel Exits a Winner" - Nebula Award Nominee 1991 "Buffalo" - Sturgeon Award Winner, Locus Award Winner, Hugo Award Nominee, Nebula Award Nominee 1993 "The Franchise" - Nebula Award nominee, Hugo Award nominee, novelette 1996 "The Miracle of Ivar Avenue" - Nebula Award nominee, novelette 1998 "Every Angel is Terrifying" - World Fantasy Award nominee 1999 "Ninety Percent of Everything" with Jonathan Lethem and James Patrick Kelly - Nebula Award nominee, novella 2002 "Stories for Men" - James Tiptree, Jr. Award Winner, Nebula Award Nominee 2008 "Pride and Prometheus" - Nebula Award winner, Shirley Jackson Award winner, Hugo Award nominee, novelette.

1998 Memory's Tailor 2006 Feeling Very Strange: The Slipstream Anthology Features stories by Aimee Bender, Michael Chabon, Ted Chiang, Jeffrey Ford, Karen Joy Fowler, Theodora Goss, Jonathan Lethem, Kelly Link, M. Rickert, Benjamin Rosenbaum, George Saunders, Bruce Sterling, Jeff VanderMeer, Howard Waldrop 2007 Rewired: The Post-Cyberpunk Anthology 2009 The Secret History of Science Fiction 2011 Kafkaesque (Tachyon Publicatio

Poland–Tanzania relations

Poland–Tanzania relations refers to the diplomatic relations between the Republic of Poland and the United Republic of Tanzania. Both nations are members of the World Trade Organization. Between 1942–1944, 18,000 Polish refugees arrived to the Kenyan port city of Mombasa and taken to the territory of Tanganyika; the refugees were part of a larger exodus of between 320,000 to a million Polish evacuees who were forced out of Poland by the Soviet Union during World War II and sent to the eastern parts of the Soviet Union and Siberia. With the assistance of Anders' Army 110,000 Polish evacuees left the Soviet Union to Persia and 18,000 of those refugees were sent to East Africa. While in Tanganyika, the refugees were sent to settlement camps in Ifunda, Kidugala, Kondoa and Tengeru; the refugees would remain in Tanganyika until 1949 when many were resettled to Australia and the United Kingdom. Diplomatic relations between Poland and Tanzania were established in 1961. In 1962, Poland opened a resident embassy in Dar es Salaam.

In 1987, Tanzanian Foreign Minister Benjamin Mkapa paid an official visit to Poland. The Polish embassy was closed in 2008, Poland was accredited to Tanzania from its embassy in Nairobi, Kenya. In 2003, Benjamin Mkapa returned to Poland as President of Tanzania. In 2012, Poland opened an honorary consulate in Tanzania and in 2018, Poland re-opened its embassy in Dar es Salaam, nine years since its closure; the re-opening of the embassy was presided by Polish Foreign Minister Jacek Czaputowicz and Tanzanian Foreign Minister Augustine Mahiga. Tanzania is one of the main beneficiaries of Polish development aid and Tanzania is one of Poland's priority partners in Sub-Saharan Africa. High-level visits from Poland to Tanzania Undersecretary for Foreign Affairs Bogusław Zaleski Foreign Minister Jacek Czaputowicz High-level visits from Tanzania to Poland Foreign Minister Benjamin Mkapa President Benjamin Mkapa Both nations have signed a few bilateral agreements such as an Agreement on Scientific and Technical Cooperation.

In 2017, 10,000 Polish citizens visited Tanzania. There are direct flights between Tanzania with Smartwings Poland. In 2017, trade between Poland and Tanzania totaled $108.5 million USD. Poland's main exports to Tanzania include: grain. Tanzania's main exports to Poland are coffee. Poland's foreign direct investment in Tanzania reached $110 million in 2017, much of it in support of the agricultural sector through loans. Poland has an embassy in Dar es Salaam. Tanzania is accredited to Poland from its embassy in Germany. Evacuation of Polish civilians from the USSR in World War II List of Polish refugees cemeteries in Africa

Biological therapy for inflammatory bowel disease

Biological therapy, the use of medications called biopharmaceuticals or biologics that are tailored to target an immune or genetic mediator of disease, plays a major role in the treatment of inflammatory bowel disease. For diseases of unknown cause, molecules that are involved in the disease process have been identified, can be targeted for biological therapy. Many of these molecules, which are cytokines, are directly involved in the immune system. Biological therapy has found a niche in the management of cancer, autoimmune diseases, diseases of unknown cause that result in symptoms due to immune related mechanisms. Inflammatory bowel disease, a collection of systemic diseases involving inflammation of the gastrointestinal tract, includes two diseases of unknown causation: ulcerative colitis, which affects only the large bowel. Although the causes of these diseases are unknown, environmental and other mechanisms have been proposed. Of these, the immune system plays a large role in the development of symptoms.

Given this, a variety of biological therapies have been developed for the treatment of these diseases. Although the use of antibodies to treat diseases can be dated back to the 1800s, biologic therapy as we know it today is a new concept for the treatment of inflammatory bowel disease; the previous treatment options had many shortcomings, the introduction of biological therapy changed the way physicians treat Crohn's disease and ulcerative colitis. So, biologic therapy still has its faults such as high cost and risk of side effects. A lot of research is being done in fields like biosimilars and oral delivery to address these concerns; the use of antibodies to treat diseases can be traced all the way back to the late 1800s with the advent of diphtheria antitoxin for the treatment of diphtheria. It wasn't until the 1900s that the newly emerging class of derived medications such as sera and antitoxins began to be referred to as biologics; the definition for biologics and biological therapy has changed a lot since.

The development of recombinant DNA technology in the 1970s shaped the modern understanding of what constitutes as biological therapy, which does not include traditional biological substances like vaccines. Today, biological therapy most refers to the use of proteins, such as monoclonal antibodies, to regulate the immune system in the treatment of disease. In 1975, Georges J. F. Köhler and César Milstein generated the first monoclonal antibodies using their own hybridoma technology, they started the field of monoclonal antibody development and won the Nobel Prize for Medicine in 1984 for their work. Soon after, muromonab-CD3 became the first licensed monoclonal antibody in 1986 for its use in treating kidney transplant rejection. Since over 70 monoclonal antibodies have been approved by the FDA; the advancements in biological therapy changed how IBD is treated. Patients with Crohn's disease and ulcerative colitis show an increase in proinflammatory cytokines such as IL-1, IL-6, IL-8, IL-23, TNF.

In 1988, a monoclonal antibody called infliximab was discovered at New York University's School of Medicine. Infliximab works by binding to TNF, it was used for the treatment of Crohn's disease and it became the first FDA approved TNF inhibitor in 1998. Infliximab as well as other TNF inhibitors like adalimumab and golimumab are the most common biologics used in the treatment of both Crohn's disease and ulcerative colitis; the other main categories of biologics that treat IBD are integrin receptor antagonists such as vedolizumab and natalizumab and interleukin antagonists like ustekinumab. Prior to the development of biological therapy as a modality to treat IBD, other medications that modulate the immune system—including 5-aminosalicylates, steroids and other immunosuppressants—were used in treatment. Corticosteroids are effective in inducing clinical remission in patients with active IBD, but they can't be used long term due to the risk of steroid-dependence and harsh side effects; the other medications like 5-aminosalicylates and azathioprine are used to reduce steroid use while maintaining remission, but their actual effect on the state of the disease and the need for surgery remains unknown.

Patients with Crohn's disease that developed complications, including fistulae were treated with surgery. Patients with ulcerative colitis who do not respond to medications are still treated with colectomy. However, basic science research showed that many cytokines were elevated in both Crohn's disease and ulcerative colitis. Crohn's disease cytokines are of the type 1 cytokines, which include TNF-α, interleukin-2, interferon γ. Ulcerative colitis was less conclusively linked to the production of Th2 cytokines. TNF inhibiting biological therapies were used in IBD patients who weren't responding to conventional therapy, they proved to be effective in some patients, shifting treatment goals from improving symptoms to changing the course of the disease by reversing mucosal inflammation and preventing long-term complications and surgery. Although there are strong initial responses in some patients, biologic therapies have their downsides, there is still a debate as to what the most effective treatment strategy is.

TNF inhibitors are the first drug prescribed when