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72,267,085 | https://en.wikipedia.org/wiki/Weather%20drone | A weather drone, or weather-sensing uncrewed aerial vehicle (UAV), – is a remotely piloted aircraft weighing less than 25 kg and carrying sensors that collect thermodynamic and kinematic data from the mid and lower atmosphere (e.g. up to 6 km).
Weather drones are not yet used to support National Meteorological and Hydrological Services (NMHS) due to ongoing negotiations on UAVs’ access to airspace and compliance with airspace regulations and technological development needed to meet the World Meteorological Organization's requirements.
Mostly, weather drones are deployed to support scientific research missions and industry-specific operations.
History
Early proposals
The first recorded UAV for measuring atmospheric parameters was in 1970, when a “small radio-controlled aircraft [was used] as a measuring platform” for sharing meteorological measurement results. The study was supported by the Air Force Cambridge Research Laboratory and NASA, Wallops Station. The authors pointed out the need for “a simple, economical, controllable, and recoverable platform to carry meteorological sensors and instrumentation” and demonstrated that using a small, radio-controlled aircraft to collect weather data was both feasible and useful.
The second milestone in the development of weather drones was the prototype built by a group of researchers at the University of Colorado, sponsored by the U.S. Office of Naval Research (ONR) in 1993. The goal of the fixed-wing drone called Aerosonde was to enable weather data collection in remote and inaccessible regions of the globe. In 1995, further developments were conducted in Australia by Environmental Systems and Services (ES&S) Pty Ltd. having the Australian Bureau of Meteorology and Insitu Group as subcontractors. In 1999, all operations and development started to be undertaken by Australian-based Aerosonde Ltd. Since 2007, Aerosonde Ltd. has been part of the American industrial conglomerate Textron Inc. By 2016, the Aerosonde had become an intelligence, surveillance and reconnaissance (ISR) aircraft for military operations and its weather data collection feature, secondary.
Later development
In 2009, the American National Research Council published the report “Observing Weather and Climate from the Ground Up: A Nationwide Network of Networks”, emphasizing the need for more adequate vertical mesoscale observation methods than radiosondes launched by weather balloons – the major system used to collect data from that atmospheric layer.
Since then, research programs focusing on weather drones have been increasing. The Center for Autonomous Sensing and Sampling at the University of Oklahoma is the most active group in this domain. Its researchers have been developing the CopterSonde and created the 3D Mesonet concept, a network of stations from which weather drones are launched every hour or two to collect data from the mesoscale.
In 2022, the US National Oceanic and Atmospheric Administration (NOAA) deployed a weather drone, the Area-I Altius-600, into a hurricane (Hurricane Ian) for the first time. The fixed-wing drone flew at lower heights (900 m - 1.3 km) inside the eye of the hurricane and into the eyewall to collect temperature, pressure, and moisture values.
Commercially available weather drones are scarce, with most of the market being supplied by Swiss company Meteomatics AG, developer and manufacturer of Meteodrones since 2013. In 2020, British company Menapia entered the market with MetSprite.
Types
Fixed-wing
The first weather drones used fixed-wings as it allowed researchers to implement technological advances from the piloted aircraft domain and to cover a larger area owing to its capacity to fly for long hours.
Rotary-wing
Rotary-wing weather drones are more popular because they are more versatile, easier to operate, and more suitable for vertical profiles than radiosondes which drift away.
Advantages and limitations
In 2019, in cooperation with the French national meteorology service Météo-France, the World Meteorological Organization (WMO) organized the “WMO Workshop on Use of Unmanned Aerial Vehicles (UAV) for Operational Meteorology Report”, the first workshop to discuss the application of weather drones. Amongst the participants, there were members of national meteorological centers, university research groups, and private companies.
The workshop discussions concluded that weather drones were useful to collect in-situ measurements from the boundary layer, closing the data gap and improving the numerical weather prediction accuracy. But a list of barriers needed to be addressed before weather drones could support national meteorological services, including:
Lack of drone-specific regulations in national or region wide airspace regulation
Limited level of automation of flight, refueling, and maintenance of fuel levels
Furthermore, resolving in-flight atmospheric icing and excessive wind resistance was also needed to ensure weather drones' safety and prevent loss. Since the development of the first Aerosonde, in the 1990s, research has been conducted to solve the issue of icing, which has caused the loss of many aircraft. In 2016, Swiss company Meteomatics was the first organization to develop a deicing system that heats the rotor blades whenever icing risk is detected.
References
Meteorological instrumentation and equipment
Unmanned aerial vehicles | Weather drone | [
"Technology",
"Engineering"
] | 1,024 | [
"Meteorological instrumentation and equipment",
"Measuring instruments"
] |
72,268,199 | https://en.wikipedia.org/wiki/Johnny%20Jordaanplein | The Johnny Jordaanplein, also known as Johnny Jordaan Square is a public square in the center of the Dutch city of Amsterdam which features outdoor sculptures. The square was named for musician Johnny Jordaan and it was dedicated in 1991.
History
The square was named for a popular musician in the mid-1900s: Johnny Jordaan which was the stage name of Johannes Hendricus van Musscher. There is a colorful hut in the small square and bronze sculptures of Jordaan musical hall of fame. The English name for the square is "Johnny Jordaan Square". Jordaan died in died in 1989 and shortly after his death there were proposals to dedicate the square. A statue of Johnny Jordaan was unveiled in 1991. There are sculptures of other performers: Tante Leen, Johnny Meijer, Manke Nelis and Jan & Mien in the square.
Design
The square is located on the end of the Elandsgracht next to the De Land Cafe. The exact location is where the Elandsgracht meets the Prinsengracht. The location is a popular meeting place for the residents of Jordaan. Two Separate locations competed for the title Johnny Jordaanplein. The singer lived in Staatsliedenbuurt in his final years but the location selected was on the Elandsgracht in the Jordaan neighborhood.
See also
List of outdoor sculptures in the Netherlands
References
Urban planning
Garden squares
Squares in Amsterdam
Outdoor sculptures in Amsterdam | Johnny Jordaanplein | [
"Engineering"
] | 307 | [
"Urban planning",
"Architecture"
] |
72,270,279 | https://en.wikipedia.org/wiki/Cubical%20bipyramid | In 4-dimensional geometry, the cubical bipyramid is the direct sum of a cube and a segment, {4,3} + { }. Each face of a central cube is attached with two square pyramids, creating 12 square pyramidal cells, 30 triangular faces, 28 edges, and 10 vertices. A cubical bipyramid can be seen as two cubic pyramids augmented together at their base.
It is the dual of a octahedral prism.
Being convex and regular-faced, it is a CRF polytope.
Coordinates
It is a Hanner polytope with coordinates:
[2] (0, 0, 0; ±1)
[8] (±1, ±1, ±1; 0)
See also
Tetrahedral bipyramid
Dodecahedral bipyramid
Icosahedral bipyramid
References
External links
Cubic tegum
4-polytopes | Cubical bipyramid | [
"Mathematics"
] | 190 | [
"Geometry",
"Geometry stubs"
] |
72,270,499 | https://en.wikipedia.org/wiki/Catie%20Cuan | Catie Cuan is an artist and innovator in the field of choreorobotics. She graduated with a Ph.D., focusing in robotics, from Stanford University in the Department of Mechanical Engineering.
Early life and education
She earned a bachelor’s degree from the University of California, Berkeley. As a ballet dancer and choreographer, she has performed with the Metropolitan Opera Ballet and the Lyric Opera of Chicago.
Career
Cuan credits her work in robotics to the experience after her father had experienced a stroke, and was surrounded by medical machines, and how people might, "feel empowered and hopeful rather than afraid."
In 2020, she was the dancer and choreographer of the show, “Output,” which was part of a collaboration with ThoughtWorks Arts and the Pratt Institute. In the production, she danced with an ABB IRB 6700 industrial robot.
In 2022, she was named as an IF/THEN ambassador for the American Association for the Advancement of Science. She was the Futurist-in-Residence at the Smithsonian Arts and Industries Building and performed at the closing ceremonies of the FUTURES exhibit on July 6, 2022.
Cuan has also contributed to product designs, working with IDEO and Dutch interior design firm moooi on their Piro project which is dancing scent diffuser robot launched for Milan Design Week in June 2022.
References
External links
American choreographers
Robotics
American roboticists
University of California, Berkeley alumni
Living people
Year of birth missing (living people) | Catie Cuan | [
"Engineering"
] | 303 | [
"Robotics",
"Automation"
] |
72,270,705 | https://en.wikipedia.org/wiki/Gabriela%20Araujo-Pardo | Martha Gabriela Araujo-Pardo is a Mexican mathematician specializing in graph theory, including work on graph coloring, Kneser graphs, cages, and finite geometry. She is a researcher at the National Autonomous University of Mexico in the Mathematics Institute, Juriquilla Campus, and the 2024–2026 president of the Mexican Mathematical Society.
Education and career
Araujo studied mathematics at the National Autonomous University of Mexico (UNAM), where she completed her Ph.D. in 2000. Her dissertation, Daisy Structure in Desarguesian Projective Planes, was supervised by Luis Montejano Peimbert. She has worked for the UNAM Mathematics Institute since 2000, with a postdoctoral research visit to the Polytechnic University of Catalonia in Spain.
She is the president of the Mexican Mathematical Society (SMM) for the term 2024–2026.
Recognition
In 2004, Araujo was awarded the Sofía-Kovalevskaia grant. In 2013, Araujo won UNAM's Sor Juana Inés de la Cruz 2013 award, and was elected to the Mexican Academy of Sciences. In 2024, Araujo was named Fellow of The World Academy of Sciences (TWAS).
Service
In 2012, Araujo served as the spokesperson of the board of Trustees of the Mexican Mathematical Society. In collaboration with other members, they funded the Equity and Gender Commission of the SMM in 2013, "to promote the inclusion of underrepresented groups, in particular women, in the mathematical activity of the country". She was part of the Commission from 2014 to 2018. She was a member of the Directive Commission and the Diversity and Gender Commission of the Union of Mathematical Societies in Latin America and the Caribbean (UMALCA) from 2021 to 2024.
Araujo is the ambassador for Mexico in the Committee of Women of Mathematics of the International Mathematical Union. She was president of the Mexican Mathematical Society (SMM) for the term 2022–2024 and has been reelected for 2024–2026.
References
External links
Home page
Year of birth missing (living people)
Living people
Mexican mathematicians
Mexican women mathematicians
Graph theorists
National Autonomous University of Mexico alumni
Members of the Mexican Academy of Sciences | Gabriela Araujo-Pardo | [
"Mathematics"
] | 451 | [
"Mathematical relations",
"Graph theory",
"Graph theorists"
] |
72,272,631 | https://en.wikipedia.org/wiki/Dmitry%20Bandura | Dmitry Bandura is a Soviet-born Canadian scientist, notable for being one of the co-inventors of the Mass cytometry technology. Bandura co-founded DVS Sciences in 2004 (acquired by Fluidigm in 2014 and then renamed to Standard BioTools in 2022) along with Drs Vladimir Baranov, Scott D. Tanner, and Olga Ornatsky.
Biography
Bandura grew up in Chernivtsi, Ukraine, where he graduated from school #35 with distinction. He received an MSc in engineering physics in 1985 and a PhD in technical sciences, both supervised by Professor Alexander A. Sysoev at Moscow Engineering Physics Institute. His PhD thesis research focused on elemental analysis of hypervelocity microparticles via time-of-flight mass spectrometry (TOF-MS) of their impact-induced plasma.
Bandura emigrated to Australia in 1992, where he worked as a Research Physicist at GBC Scientific Equipment. There, he worked on the development of inductively coupled plasma mass spectrometry (ICP-MS), contributing to the release of the award-winning Optimass 8000 ICP-TOF-MS in 1998. Bandura then relocated to Toronto, Canada, where he joined MDS SCIEX (now Sciex) to continue working on the development of new ICP-MS instrumentation methods, particularly in the area of collision and reaction cells.
In 2005, together with Scott D. Tanner and Vladimir Baranov, Bandura began independently developing an ICP-TOF-MS based cytometer and became a researcher at the University of Toronto in March 2005. After securing ample funding by 2010 from various sources, including National Institutes of Health, Ontario Institute for Cancer Research (OICR), the Ministry of Research and Innovation, Ontario Centres of Excellence, Health Technology Exchange, and Genome Canada via the Ontario Genomics Institute, and venture capital from 5 AM Ventures, Bandura and the DVS Sciences team successfully commercialized their technology, leading to the acquisition of DVS Sciences by Fluidigm in 2014
Bandura headed R&D and Canadian operations at Fluidigm Canada following the merger and Standard BioTools Canada (formerly DVS Sciences) following a capital infusion in 2022, stewarding the development of the next generation of mass cytometry and imaging mass cytometry instruments and reagents.
Awards and honors
2019 HUPO Award (Human Proteome Organization) for “development of a unique high-parameter mass cytometry technology that brings unprecedented understanding of single cell proteomics”, together with the co-inventors Scott D. Tanner, Vladimir Baranov and Olga Ornatsky.
The Analytical Scientist Innovation Award 2017: #1 New Product of 2017 for the Fluidigm Hyperion Imaging System, as a leader of the development team
2004 Elsevier / Spectrochimica Acta Atomic Spectroscopy Award for the most important paper published in Spectrochimica Acta Part B in 2002 (Title: Reaction cells and collision cells for ICP-MS: a tutorial review) in co-authorship with Scott D. Tanner and Vladimir Baranov
1998 R&D World 100 Winners in Analytical instrumentation for the GBC Optimass 8000
Fellow of the Royal Society of Chemistry (UK)
Publications
Sept 2010 - Highly Multiparametric Analysis by Mass Cytometry
Aug 2009 - Mass Cytometry: Technique for Real Time Single Cell Multitarget Immunoassay Based on Inductively Coupled Plasma Time-Of-Flight Mass Spectrometry (1148 citations as of January 28, 2023)
Sept 2002 - Reaction Cells and Collision Cells for ICP-MS: A Tutorial Review
Feb 2002 - A Sensitive and Quantitative Element-Tagged Immunoassay with ICPMS Detection
Feb 2002 - Detection of Ultratrace Phosphorus and Sulfur by Quadrupole ICPMS with Dynamic Reaction Cell
July 2001 - Reaction Chemistry and Collisional Processes in Multipole Ddevices for Resolving Isobaric Interferences in ICP–MS
A more complete listing of his publications can be found on Google scholar
Book
References
External links
Standard BioTools Corporate website (Formerly Fluidigm, Formerly DVS Sciences)
Living people
Canadian physicists
Mass spectrometrists
Moscow Engineering Physics Institute alumni
Scientists from Chernivtsi
Year of birth missing (living people) | Dmitry Bandura | [
"Physics",
"Chemistry"
] | 896 | [
"Biochemists",
"Mass spectrometry",
"Spectrum (physical sciences)",
"Mass spectrometrists"
] |
72,272,643 | https://en.wikipedia.org/wiki/Vladimir%20Baranov | Vladimir Baranov is a Soviet born Canadian scientist and one of the original co-inventors of Mass cytometry technology...
He co-founded DVS Sciences in 2004 (acquired by Fluidigm in 2014 and then renamed to Standard BioTools in 2022) along with Dmitry Bandura,Scott D. Tanner and Olga Ornatsky.
Biography
In 1993, he immigrated to Canada. Prior to the formation of DVS Sciences. Dr. Baranov, a senior scientist at MDS SCIEX, was a key member of the research team that developed and promoted the Dynamic Reaction Cell®, which remains today at the pinnacle of quadrupole ICP-MS technology.
In 2005, together with Scott D. Tanner and Dmitry Bandura, he began independently developing an ICP-TOF-MS based cytometer and became a researcher at the University of Toronto in March 2005. After securing ample funding by 2010 from various sources, including National Institutes of Health, Ontario Institute for Cancer Research (OICR), the Ministry of Research and Innovation, Ontario Centres of Excellence, Health Technology Exchange, and Genome Canada via the Ontario Genomics Institute, and venture capital from 5 AM Ventures, Vladimir and the DVS Sciences team successfully commercialized their technology, leading to the acquisition of DVS Sciences by Fluidigm in 2014
Baranov was a principal scientist at DVS Sciences (and then Fluidigm) developing instrumental concepts and algorithmics that advance the CyTOF® line of products. He also and played a fundamental role in the development of the MaxPar line of metal-labeling reagents until his retirement in 2019.
Education
M.Sc. at Moscow State University
PhD in physical chemistry at Moscow State University - 1987
Career
Assistant to the chair of physical chemistry at Moscow State University.
Research associate at York University
Senior scientist at MDS SCIEX
Associate professor at UofT in IBBME (2005–2008) and chemistry (2008–2011).
Adjunct professor at York University.
Principal scientist at DVS Sciences - 2005–2019 (acquired by Fluidigm in 2014 and then Standard BioTools in 2022)
Research
Quadrupole theory (stability, acceptance and transmission of multipole RF and electrostatic driven devises), molecular gas dynamics, and supersonic beam expansion into vacuum.
Development of the DRC Collision/reaction cell.
Development of mass spectrometry (CyTOF), including fundamentals of operation and design of different MS instrumentation.
Awards and honors
2019 HUPO Award (Human Proteome Organization)
2004 Elsevier / Spectrochimica Acta Atomic Spectroscopy Award for the most important paper published in Spectrochimica Acta Part B in 2002 (Title: Reaction cells and collision cells for ICP-MS: a tutorial review) in co-authorship with Scott D. Tanner and Dmitry Bandura
2001 Manning Innovation Award, Award of Distinction Dr. Vladimir Baranov, together with Scott D. Tanner, received the Manning Award of Distinction from the Manning Innovation Awards Foundation for the remarkable invention of the ICP-MS Dynamic Reaction Cell (Collision/reaction cell).
1999 Pittcon Editors' Awards Perkin-Elmer Sciex for their ELAN 6100 DRC (Dynamic Reaction Cell) ICP-MS system.
Publications
Feb 2017 - Imaging Mass Cytometry.
Sept 2010 - Highly Multiparametric Analysis by Mass Cytometry.
July 2009 - Mass Cytometry: Technique for Real Time Single Cell Multitarget Immunoassay based on Inductively Coupled Plasma Time-Of-Flight Mass Spectrometry
Aug 2007 - Polymer‐Based Elemental Tags for Sensitive Bioassays.
Sept 2002 - Reaction Cells and Collision Cells for ICP-MS: a tutorial review.
May 2002 - A Sensitive and Quantitative Element-Tagged Immunoassay with ICPMS Detection.
Feb 2002 - Detection of Ultratrace Phosphorus and Sulfur by Quadrupole ICPMS with Dynamic Reaction Cell.
July 2001 - Reaction Chemistry and Collisional Processes in Multipole Devices for Resolving Isobaric Interferences in ICP–MS.
Jan 2000 - A Dynamic Reaction Cell for Inductively Coupled Plasma Mass Spectrometry (ICP-DRC-MS). Part III. Optimization and Analytical Performance.
Nov 1999 - A Dynamic Reaction Cell for Inductively Coupled Plasma Mass Spectrometry (ICP-DRC-MS). Part II. Reduction of Interferences Produced within the Cell.
March 1999 - Theory, Design, and Operation of a Dynamic Reaction Cell for ICP-MS.
Feb 1997 - Activation of Hydrogen and Methane by Thermalized FeO+ in the Gas Phase as Studied by Multiple Mass Spectrometric Techniques.
A more complete listing of his publications can be found on Google Scholar
References
External links
Standard BioTools Corporate website (Formerly Fluidigm, Formerly DVS Sciences)
Mass spectrometrists
Canadian chemists
Moscow State University alumni
Living people
Year of birth missing (living people) | Vladimir Baranov | [
"Physics",
"Chemistry"
] | 1,016 | [
"Biochemists",
"Mass spectrometry",
"Spectrum (physical sciences)",
"Mass spectrometrists"
] |
72,272,651 | https://en.wikipedia.org/wiki/Scott%20D.%20Tanner | Scott Tanner is a Canadian scientist, inventor, and entrepreneur. His areas of expertise include mass spectroscopy, especially inductively coupled plasma mass spectrometry (ICP-MS), and mass cytometry.
Tanner is best known for his work on the fundamentals of inductively coupled plasma mass spectrometry, for the invention of mass cytometry, and co-founding (with Dmitry Bandura, Vladimir Baranov and Olga Ornatsky) DVS Sciences in 2004,(acquired by Fluidigm in 2014 and then renamed to Standard BioTools in 2022) the company that first commercialized the instrument and reagents of mass cytometry.
Early life and education
Tanner was born and raised in St. Catharines, Ontario Canada. He bought his first chemistry set, from his brother, at age 6. Through his early teenage years, he was provided with laboratory space at Brock University, under the guidance of Dr. E.A. Cherniak and Dr. F.P. Koffyberg, where he attempted to replicate Geiger–Marsden experiments also known as Rutherford's experiment (scattering of alpha particles by gold foil) using various home-built instruments, including cloud chambers.
Tanner graduated with a BSc in chemistry from York University in 1976. During his undergraduate years, he became a nationally ranked gymnast. An injury at the Olympic trials ended his competitive gymnastics career, and he took up marathon running during graduate school (best time 2:47:13). He received a Doctor of Philosophy (Chemistry) from York University in 1980, having studied ion-molecule reaction kinetics and flame ion chemistry with Drs. D.K Bohme and J.M. Goodings.
Biography
Tanner joined SCIEX, which later became MDS SCIEX, in 1980 as a research scientist. He became principal scientist in 2000. In his 25 years at SCIEX, Tanner developed and helped to commercialize a string of mass spectrometry products.
Tanner published over 74 peer-reviewed scientific articles, and holds 22 US patents (with corresponding filings in other countries), including 13 patents on Mass Cytometry technology
Tanner was a co-founder of DVS Sciences and, as the president and CEO, saw the company through the development and commercial launch of its first products.
The products that DVS Sciences brought to the global market were originally developed at the University of Toronto where Tanner was a professor in the Institute of Biomaterials and Biomedical Engineering and then in chemistry.
Career
Principal Scientist SCIEX - 1980-2005
Associate Professor (CLTA) at the University of Toronto, first in the Institute of Biomaterials and Biomedical Engineering (2005–2008) and then in Chemistry 2008–2013.
President DVS Sciences 2004 - 2015 (acquired by Fluidigm in 2014)
Adjunct Professor at York University in the Department of Chemistry 2015–2018
Volunteer Work
Chair of the Three Churches Heritage Foundation in Mahone Bay - 2020–Present
Books
2003 - Plasma Source Mass Spectrometry: Applications and Emerging Technologies
2001 - Plasma Source Mass Spectrometry: The New Millennium
1999 - Plasma Source Mass Spectrometry: New Developments and Applications
1997 - Plasma Source Mass Spectrometry: Developments and Applications
Research
Detection of TCDD (dioxin) in soil and water, explosives, chemical agents.
Development of the ELAN 6000 ICP-MS
Development of the DRC Collision/reaction cell
Development of Mass cytometry see also CyTOF
Awards and honors
2024 York U Alumni Award for Outstanding Achievement
2020 Lifetime Achievement Award in Plasma Spectrochemistry
2019 HUPO Award (Human Proteome Organization)
2014 Fellow of the American Institute for Medical and Biological Engineering
2011 University of Toronto Inventor of the Year Award for Biomedical and Life Sciences
2011 Thermo Fisher Scientific Spectroscopy Award
2004 Elsevier / Spectrochimica Acta Atomic Spectroscopy Award for the most important paper published in Spectrochimica Acta Part B in 2002 (Title: Reaction cells and collision cells for ICP-MS: a tutorial review) in co-authorship with Dmitry Bandura and Vladimir Baranov
2003 W.A.E. McBryde medal from the Canadian Chemical Society of the Chemical Institute of Canada
2001 Manning Innovation Award, Award of Distinction Dr. Scott Tanner, together with Dr. Vladimir Baranov, received the Manning Award of Distinction from the Manning Innovation Awards Foundation for the remarkable invention of the ICP-MS Dynamic Reaction Cell (Collision/reaction cell).
1999 Pittcon Editors' Awards Perkin-Elmer Sciex for their ELAN 6100 DRC (Dynamic Reaction Cell) ICP-MS system.
Fellow of the Royal Society of Chemistry (UK)
Fellow of the American Institute for Medical and Biological Engineering (AIMBE)
Publications
Scott has published more than 75 peer-reviewed articles. The 13 most cited (more than 200 citations each) include:
May 2011 - Single-Cell Mass Cytometry of Differential Immune and Drug Responses Across a Human Hematopoietic Continuum )
Sept 2010 - Highly Multiparametric Analysis by Mass Cytometry
Aug 2009 - Mass Cytometry: Technique for Real Time Single Cell Multitarget Immunoassay Based on Inductively Coupled Plasma Time-Of-Flight Mass Spectrometry
Sept 2002 - Reaction Cells and Collision Cells for ICP-MS: A Tutorial Review
April 2002 - A Sensitive and Quantitative Element-Tagged Immunoassay with ICPMS Detection
April 2002 - Detection of Ultratrace Phosphorus and Sulfur by Quadrupole ICPMS with Dynamic Reaction Cell
July 2001 - Reaction Chemistry and Collisional Processes in Multipole Devices for Resolving Isobaric Interferences in ICP–MS
Aug 2000 - A Dynamic Reaction Cell for Inductively Coupled Plasma Mass Spectrometry (ICP-DRC-MS). Part III.
Nov 1999 - A Dynamic Reaction Cell for Inductively Coupled Plasma Mass Spectrometry (ICP-DRC-MS). Part II. Reduction of Interferences Produced within the Cell
March 1999 - Theory, Design, and Operation of a Dynamic Reaction Cell for ICP-MS
Jan 1995 - Characterization of Ionization and Matrix Suppression in Inductively Coupled ‘Cold’ Plasma Mass Spectrometry
June 1992 - Space Charge in ICP-MS: Calculation and Implications
July 1988 - Nonspectroscopic Interelement Interferences in Inductively Coupled Plasma Mass Spectrometry
A more complete listing of his publications can be found on Google Scholar
References
External links
Standard BioTools Corporate website (Formerly Fluidigm, Formerly DVS Sciences)
Mass spectrometrists
Canadian chemists
Fellows of the American Institute for Medical and Biological Engineering
Fellows of the Royal Society of Chemistry
York University alumni
Living people
Year of birth missing (living people) | Scott D. Tanner | [
"Physics",
"Chemistry"
] | 1,387 | [
"Biochemists",
"Mass spectrometry",
"Spectrum (physical sciences)",
"Mass spectrometrists"
] |
72,272,657 | https://en.wikipedia.org/wiki/Olga%20Ornatsky | Olga Ornatsky is a Soviet born, Canadian scientist. Ornatsky co-founded DVS Sciences in 2004 (acquired by Fluidigm in 2014 and then renamed to Standard BioTools in 2022) along with Dmitry Bandura, Vladimir Baranov and Scott D. Tanner.
Biography
Ornatsky graduated from the Moscow State University, Department of Biology. In 1989, she completed her Ph.D. in cell and molecular biology, and worked as a research scientist at the Cardiology Centre studying vascular smooth muscle involvement in atherosclerosis. In 1993, she immigrated to Canada, and became a postdoctoral research fellow at York University. She quickly progressed to become senior research associate in the Laboratory of Vascular Biology and Cardiac Surgery at St. Michael's Hospital (Toronto). Her achievements brought her to MDS Proteomics Inc. (now Protana Inc), where she led her research group as a senior scientist for four years.
In 2005, she left MDS to pursue a different direction. Together with the co-founders of DVS Sciences Inc. Scott D. Tanner, Vladimir Baranov and Dmitry Bandura, she helped develop the CyTOF™ Mass Cytometer, for highly multi-parametric single cell analysis at the Department of Chemistry, University of Toronto. Olga held the position of director of Bioassay Development at DVS Sciences, Inc. After the merger with Fluidigm Inc in 2014, she transitioned to principal scientist, Proteomics division, and led a group of biology and chemistry researchers involved in developing new metal-tagged affinity reagents, as well as methods and applications for Mass cytometry until her retirement in 2019.
Education
M.Sc. in biology Moscow State University
Ph.D. in cell and molecular biology Moscow State University- In 1989
Career
Research scientist in cardiology at Moscow State University
Postdoctoral research fellow at York University - 1993
Senior research associate, Laboratory of Vascular Biology and Cardiac Surgery at St. Michael's Hospital (Toronto)
Senior scientist MDS Proteomics, Inc. - 2001- 2005
Research associate, Institute of Biomaterials and Biomedical Engineering (IBBME), University of Toronto
Principal scientist, biology DVS Sciences - 2005 - 2019 (acquired by Fluidigm in 2014 and then Standard BioTools in 2022)
Research
Ornatsky has more than fifteen years of experience in the commercial environment as a senior strategic product application developer and in providing advanced customer/collaborator support. Her primary field of expertise is in cellular and molecular biology, with the objective of developing bioanalytical assays for mass cytometry(CyTOF). Olga is a principal inventor on several patents.
Awards and honors
2019 HUPO Award (Human Proteome Organization)
Publications
Mar 2021 Establishing CD19 B-cell reference control materials for comparable and quantitative cytometric expression analysis
April 2020 Enabling Indium Channels for Mass Cytometry by Using Reinforced Cyclambased Chelating Polylysine
April 2020 Tantalum Oxide Nanoparticle-Based Mass Tag for Mass Cytometry
Dec 2019 Tumor Platinum Concentrations and Pathological Responses Following Cisplatin-Containing Chemotherapy in Gastric Cancer Patients
Dec 2019 Skin platinum deposition in colorectal cancer patients following oxaliplatin-based therapy
Nov 2019 Automated Data Cleanup for Mass Cytometry
Aug 2019 A Metal-Chelating Polymer for Chelating Zirconium and its Use in Mass Cytometry
June 2019 Multidimensional profiling of drug-treated cells by Imaging Mass Cytometry
July 2019 Human lymphoid organ cDC2 and macrophages play complementary roles in T follicular helper responses
Feb 2019 Multidimensional Profiling of Drug-Treated Cells by Imaging Mass Cytometry
July 2019 Human lymphoid organ cDC2 and macrophages play complementary roles in T follicular helper responses
Jan 2019 Lanthanide nanoparticles for high sensitivity multiparameter single cell analysis
Mar 2018 Aptamer-facilitated mass cytometry
Feb 2018 Tumor platinum concentrations and pathological responses following preoperative cisplatin-containing chemotherapy in gastric or gastroesophageal junction cancer patients.
Feb 2018 Platinum deposition in skin as a possible mechanism for peripheral sensory neuropathy (PSN) in patients (pts) with colorectal cancer (CRC) following oxaliplatin-based therapy.
Nov 2017 Simultaneous Detection of Protein and mRNA in Jurkat and KG‐1a Cells by Mass Cytometry
July 2017 Abstract 2104: In vitro drug effects on cancer cell morphology and functional state revealed by multiparameter imaging mass cytometry
June 2017 Liposome-Encapsulated NaLnF 4 Nanoparticles for Mass Cytometry: Evaluating Nonspecific Binding to Cells
Aug 2014 Metal-chelating polymers developed for mass cytometry as a potential route to high activity radioimmunotherapeutic agents
July 2014 Single cell measurement of the uptake, intratumoral distribution, and cell cycle effects of cisplatin using mass cytometry
Nov 2013 Dual-Purpose Polymer Labels Majonis Biomacromolecules 2013
May 2013 The Means: Cytometry and Mass Spectrometry Converge in a Single Cell Deep Profiling Platform
April 2013 Dual-Purpose Polymer Labels for Fluorescent and Mass Cytometric Affinity Bioassays
April 2013 An introduction to mass cytometry: Fundamentals and applications
July 2012 Metal-Chelating Polymers by Anionic Ring-Opening Polymerization and Their Use in Quantitative Mass Cytometry
July 2012 Human CD4+ lymphocytes for antigen quantification: Characterization using conventional flow cytometry and mass cytometry
Nov 2011 MASSIVELY MULTIPARAMETER SINGLE CELL ANALYSIS BY MASS CYTOMETRY
Sept 2011 Curious Results with Palladium- and Platinum-Carrying Polymers in Mass Cytometry Bioassays and an Unexpected Application as a Dead Cell Stain
Aug 2011 Development of mass cytometry methods for bacterial discrimination
June 2011 Surface Functionalization Methods To Enhance Bioconjugation in Metal-Labeled Polystyrene Particles
June 2011 Surface Functionalization Methods To Enhance Bioconjugation in Metal-Labeled Polystyrene Particles
May 2011 Single-Cell Mass Cytometry of Differential Immune and Drug Responses Across a Human Hematopoietic Continuum
Jan 2011 Multiplexed protease assays using element-tagged substrates
Oct 2010 Synthesis of a Functional Metal-Chelating Polymer and Steps toward Quantitative Mass Cytometry Bioassays
Sept 2010 Highly multiparametric analysis by mass cytometry
Aug 2010 A Distinctive DNA Damage Response in Human Hematopoietic Stem Cells Reveals an Apoptosis-Independent Role for p53 in Self-Renewal
June 2010 Hybrid nanogels by encapsulation of lanthanide-doped LaF3 nanoparticles as elemental tags for detection by atomic mass spectrometry
Feb 2010 Metal-Containing Polystyrene Beads as Standards for Mass Cytometry
Feb 2010 Bio-Functional, Lanthanide-Labeled Polymer Particles by Seeded Emulsion Polymerization and their Characterization by Novel ICP-MS Detection
Feb 2010 Lanthanide-Containing Polymer Microspheres by Multiple-Stage Dispersion Polymerization for Highly Multiplexed Bioassays
Nov 2009 Development of inductively coupled plasma-mass spectrometry-based protease assays
July 2009 Mass Cytometry: Technique for Real Time Single Cell Multitarget Immunoassay Based on Inductively Coupled Plasma Time-of-Flight Mass Spectrometry
Mar 2009 The influence of PEG macromonomers on the size and properties of thermosensitive aqueous microgels
Feb 2009 ICP-MS-Based Multiplex Profiling of Glycoproteins Using Lectins Conjugated to Lanthanide-Chelating Polymers
Dec 2008 Flow cytometer with mass spectrometer detection for massively multiplexed single-cell biomarker assay
Dec 2008 Biocompatible Hybrid Nanogels
Aug 2008 Element-tagged immunoassay with ICP-MS detection: Evaluation and comparison to conventional immunoassays
May 2008 Study of Cell Antigens and Intracellular DNA by Identification of Element-Containing Labels and Metallointercalators Using Inductively Coupled Plasma Mass Spectrometry
Feb 2008 Development of analytical methods for multiplex bio-assay with inductively coupled plasma mass spectrometry
Dec 2007 Lanthanide-Containing Polymer Nanoparticles for Biological Tagging Applications: Nonspecific Endocytosis and Cell Adhesion
Aug 2007 Polymer-Based Elemental Tags for Sensitive Bioassays
Mar 2007 Multiplex bio-assay with inductively coupled plasma mass spectrometry: Towards a massively multivariate single-cell technology
Mar 2007 Large-scale mapping of human protein-protein interactions by mass spectrometry
Sept 2006 Messenger RNA Detection in Leukemia Cell lines by Novel Metal-Tagged in situ Hybridization using Inductively Coupled Plasma Mass Spectrometry
Feb 2006 Multiple cellular antigen detection by ICP-MS
Jan 2006 Phosphoproteomics in Drug Discovery and Development
Aug 2004 The Reproducible Acquisition of Comparative Liquid Chromatography/Tandem Mass Spectrometry Data from Complex Biological Samples
Mar 2004 Differential Phosphoprofiles of EGF and EGFR Kinase Inhibitor-Treated Human Tumor Cells and Mouse Xenografts
Jan 2004 Characterization of phosphorus content of biological samples by ICP-DRC-MS: Potential tool for cancer research
Jan 2002 Administration of exogenous endothelin-1 following vascular balloon injury: early and late effects on intimal hyperplasia
Jan 2001 Effects of Estrogen Replacement on Infarct Size, Cardiac Remodeling, and the Endothelin System After Myocardial Infarction in Ovariectomized Rats
Aug 1999 Post-translational control of the MEF2A transcriptional regulatory protein
Nov 1998 (MEF2) with a mitogen-activated protein kinase, ERK5/BMK1
Jan 1998 A Dominant-Negative Form of Transcription Factor MEF2 Inhibits Myogenesis
Aug 1997 Molecular cloning of up-regulated cytoskeletal genes from regenerating skeletal muscle: Potential role of myocyte enhancer factor 2 proteins in the activation of muscle-regeneration-associated genes
Nov 1996 MEF2 Protein Expression, DNA Binding Specificity and Complex Composition, and Transcriptional Activity in Muscle and Non-muscle Cells
Feb 1996 Dystrophin, vinculin, and aciculin in skeletal muscle subject to chronic use and disuse
Nov 1995 Effects of hypothyroidism and aortic constriction on mitochondria during cardiac hypertrophy
Nov 1995 Expression of stress proteins and mitochondrial chaperones in chronically stimulated skeletal muscle
June 1995 Mitochondrial biogenesis during pressure overload induced cardiac hypertrophy in adult rats
Mar 1989 Identification and immunolocalization of a new component of human cardiac muscle intercalated disc
Jan 1989 Modulation of human aorta smooth muscle cell phenotype: A study of muscle-specific variants of vinculin, caldesmon, and actin expression
Sept 1988 Immunolocalization of meta-vinculin in human smooth and cardiac muscles
June 1988 Diversity of vinculin/meta-vinculin in human tissues and cultivated cells. Expression of muscle specific variants of vinculin in human aorta smooth muscle cells
July 1987 Immunoreactive forms of caldesmon in cultivated human vascular smooth muscle cells
Feb 1987 Identification of smooth muscle-derived foam cells in the atherosclerotic plaque of human aorta with monoclonal antibody IIG10
Nov 1986 Metavinculin distribution in adult human tissues and cultuED cells
April 1986 Red blood cell targeting to smooth muscle cells
Oct 1985 Monoclonal antibodies that distinguish between human aorta smooth muscle and endothelial cells
Systems immunology (WS-086) WS/PP-086-01 What is “Systems Immunology” for? WS/PP-086-02 Cholinergic stimulation modulates T cell-independent humoral immune responses in the spleenWS/PP-086-03 Next-generation 31-parameter flow cytometry reveals systems-level relationships in human bone marrow signaling and homeostasisWS/PP-086-04 Organization of the autoantibody repertoire in healthy newborns and adults revealed by system level informatics of antigen microarray dataWS/PP-086-05 Methods for develo
Systems immunology (WS-086) WS/PP-086-01 What is âSystems Immunologyâ for? WS/PP-086-02 Cholinergic stimulation modulates T cell-independent humoral immune responses in the spleenWS/PP-086-03 Next-generation 31-parameter flow cytometry reveals systems-level relationships in human bone marrow signaling and homeostasisWS/PP-086-04 Organization of the autoantibody repertoire in healthy newborns and adults revealed by system level informatics of antigen microarray dataWS/PP-086-05 Methods for de
Novel polymer-based elemental tags for sensitive bio-assays
References
External links
Standard BioTools Corporate website (Formerly Fluidigm, Formerly DVS Sciences)
Mass spectrometrists
21st-century Canadian biologists
Canadian women scientists
Moscow State University alumni
Living people
Year of birth missing (living people) | Olga Ornatsky | [
"Physics",
"Chemistry"
] | 2,786 | [
"Biochemists",
"Mass spectrometry",
"Spectrum (physical sciences)",
"Mass spectrometrists"
] |
72,272,771 | https://en.wikipedia.org/wiki/Pseudescherichia | Pseudescherichia is a Gram-negative genus of non-spore-forming, facultatively anaerobic rod-shaped bacteria from the family Enterobacteriaceae. Based on conserved signature indels (CSIs) differentiating it from other members of this family, this genus and its sole species P. vulneris were divided from Escherichia, the genus of E. coli, in 2017.
A November 2022 preprint article has identified another member species from a Oryza sativa rice seedling growing in Arkansas, proposing the name P. oryzae.
References
Enterobacteriaceae
Bacteria described in 2017 | Pseudescherichia | [
"Biology"
] | 139 | [
"Bacteria stubs",
"Bacteria"
] |
72,272,864 | https://en.wikipedia.org/wiki/Yellow.ai | Yellow.ai, formerly Yellow Messenger, is a multinational company headquartered in San Mateo, California focused on customer service automation. It was founded in 2016 and provides an AI platform for automating customer support experiences across chat and voice. The platform supports more than 135 languages across more than 35 channels.
History
Yellow.ai was founded in 2016 by Raghu Ravinutala, Jaya Kishore Reddy Gollareddy, and Rashid Khan in Bangalore, India. Raghavendra Ravinutala and Jaya Kishore Reddy Gollareddy left their full-time jobs to establish Yellow.ai, and they met Rashid Khan at a college hackathon, where he began working with them. By January 2016, Yellow.ai had acquired 50,000 customers. The same year, the company rolled out a model of the application for B2B companies. This version of the software and platform was intended to support voice and chat interactions for enterprises. In 2016, the company joined Microsoft's accelerator program and SAP Startup Studio.
In April 2021, amid the COVID-19 pandemic, the company developed chatbots to assist governments with vaccinations. It launched Yellow Messenger Care to create omnichannel chatbots related to COVID-19 assistance, which helped NGOs and hospitals in their crisis management efforts. In June 2021, the company rebranded itself from Yellow Messenger to Yellow.ai. In 2022, Yellow.ai launched DynamicNLP, which was designed to eliminate the necessity for NLP model training. In 2023, Yellow.ai announced the launch of its Dynamic Automation Platform (DAP) and revealed a new logo as part of a larger rebranding strategy. In May 2023, the company also launched a proprietary small language model called as YellowG, a generative AI platform for automation workflows. The company deployed over 120 generative AI bots for businesses in 2023.
Partnership and client base
In January 2019, the company collaborated with Microsoft to work on transforming its voice automation using Azure Al Speech Services and Natural language processing (NLP) tools. In February 2022, the company partnered with Tech Mahindra to develop enterprise AI technology. It partnered with the e-commerce company Unicommerce in July 2020. In February 2022, Edelweiss General Insurance launched its AI Voice Bot, using Yellow.ai's technology. Yellow.ai implemented its AI-based customer service technology in Urja, a virtual assistant launched by the public sector company BPCL. The company has also formed partnerships with Accenture, Infosys, TCS, and Wipro.
Its clients include Sony, Flipkart, Grab, Skoda, Honda, Domino's Pizza, Bajaj Finance, Volkswagen, HDFC Bank, Ferrellgas, Indigo, Adani Capital, Haldiram, Lulu Group, Bharat Petroleum Corporation Limited, Dr. Reddy's Laboratories and Concentrix.
Funding
In June 2019, Yellow.ai completed a series A funding of $4 million led by Lightspeed Venture Partners and angel investors such as Phanindra Sama, founder of RedBus, Anand Swaminathan, senior partner, McKinsey & Company, Limeroad founder Prashant Malik, and Snapdeal founder Kunal Bahl.
In April 2020, it raised $20 million in a series B round led by Lightspeed Ventures Partners and Lightspeed India Partners. In August 2021, the company raised $78.15 million in its Series C funding round led by WestBridge Capital, Sapphire Ventures, Salesforce Ventures, and Lightspeed Venture Partners. The company has raised a total of $102 million so far.
Awards
The company won the Frost & Sullivan Technology Innovation Leadership Award in 2021. Entrepreneur magazine named Yellow.ai the Best AI Startup of the Year at the Entrepreneur India Startup Awards 2022. It was awarded Best Chat/Conversational Bot/Tool during the MarTech Leadership Summit 2022. The Financial Express awarded it the Best Use of Conversational AI – Gold at the Financial Express FuTech Awards in 2022. The company received an honorable mention in the automation solution of the Year category at the CCW Excellence Awards 2022.
Forbes magazine added Yellow.ai's co-founder Rashid Khan to Forbes India 30 Under 30 2022 and Forbes Asia 30 Under 30 2022 lists, as one of the young gamechangers disrupting the Enterprise Technology industry. Hurun Research Institute listed the company in its 'Future Unicorn Index 2022' list for India. In 2023, co-founder & CEO, Raghu Ravinutala was recognized as one of the top 50 SaaS CEOs by The Software Report. Yellow.ai ranked 13th in the Bay Area and 88th nationally on the 2023 Deloitte Technology Fast 500 for North America.
See also
Amazon Alexa
Bixby (virtual assistant)
Cortana (software)
Google Assistant
Apple Siri
Viv (software)
References
Virtual assistants
Internet properties established in 2016
Natural language processing software
2016 establishments in Karnataka
2016 software
Instant messaging
Indian companies established in 2016
Indian brands | Yellow.ai | [
"Technology"
] | 1,027 | [
"Instant messaging"
] |
63,556,609 | https://en.wikipedia.org/wiki/Ursescu%20theorem | In mathematics, particularly in functional analysis and convex analysis, the Ursescu theorem is a theorem that generalizes the closed graph theorem, the open mapping theorem, and the uniform boundedness principle.
Ursescu theorem
The following notation and notions are used, where is a set-valued function and is a non-empty subset of a topological vector space :
the affine span of is denoted by and the linear span is denoted by
denotes the algebraic interior of in
denotes the relative algebraic interior of (i.e. the algebraic interior of in ).
if is barreled for some/every while otherwise.
If is convex then it can be shown that for any if and only if the cone generated by is a barreled linear subspace of or equivalently, if and only if is a barreled linear subspace of
The domain of is
The image of is For any subset
The graph of is
is closed (respectively, convex) if the graph of is closed (resp. convex) in
Note that is convex if and only if for all and all
The inverse of is the set-valued function defined by For any subset
If is a function, then its inverse is the set-valued function obtained from canonically identifying with the set-valued function defined by
is the topological interior of with respect to where
is the interior of with respect to
Statement
Corollaries
Closed graph theorem
Uniform boundedness principle
Open mapping theorem
Additional corollaries
The following notation and notions are used for these corollaries, where is a set-valued function, is a non-empty subset of a topological vector space :
a convex series with elements of is a series of the form where all and is a series of non-negative numbers. If converges then the series is called convergent while if is bounded then the series is called bounded and b-convex.
is ideally convex if any convergent b-convex series of elements of has its sum in
is lower ideally convex if there exists a Fréchet space such that is equal to the projection onto of some ideally convex subset B of Every ideally convex set is lower ideally convex.
Related theorems
Simons' theorem
Robinson–Ursescu theorem
The implication (1) (2) in the following theorem is known as the Robinson–Ursescu theorem.
See also
Notes
References
Theorems involving convexity
Theorems in functional analysis | Ursescu theorem | [
"Mathematics"
] | 474 | [
"Theorems in mathematical analysis",
"Theorems in functional analysis"
] |
63,557,168 | https://en.wikipedia.org/wiki/Human%20factors%20in%20diving%20equipment%20design | Human factors in diving equipment design are the influences of the interactions between the user and equipment in the design of diving equipment and diving support equipment. The underwater diver relies on various items of diving and support equipment to stay alive, healthy and reasonably comfortable and to perform planned tasks during a dive.
Divers vary considerably in anthropometric dimensions, physical strength, joint flexibility, and other factors. Diving equipment should be versatile and chosen to fit the diver, the environment, and the task. How well the overall design achieves a fit between equipment and diver can strongly influence its functionality. Diving support equipment is usually shared by a wide range of divers and must work for them all. When correct operation of equipment is critical to diver safety, it is desirable that different makes and models should work similarly to facilitate rapid familiarisation with new equipment. When this is not possible, additional training for the required skills may be necessary.
The most difficult stages for recreational divers are out of water activities and transitions between the water and the surface site, such as carrying equipment on shore, exiting from water to boat and shore, swimming on the surface, and putting on equipment. Safety and reliability, adjustability to fit the individual, performance, and simplicity were rated the most important features for diving equipment by recreational divers.
The professional diver is supported by a surface team, who are available to assist with the out-of-water activities to the extent necessary, to reduce the risk associated with them to a level acceptable in terms of the governing occupational safety and health regulations and codes of practice. This tends to make professional diving more expensive, and the cost tends to be passed on to the client.
Human factors engineering (HFE), also known as human factors and ergonomics, is the application of psychological and physiological principles to the engineering and design of equipment, procedures, processes, and systems. Primary goals of human factors engineering are to reduce human error, increase productivity and system availability, and enhance safety, health and comfort with a specific focus on the interaction between the human and equipment.
General principles
Diving equipment is used to facilitate underwater activity by the diver. The primary requirements are to keep the diver alive and healthy, while secondary requirements include providing comfort and the capacity to perform required tasks. Safe operation requires correct equipment function as well as diver competence.
Fault tolerance is the property that enables a system to continue operating properly in the event of the failure of some of its components. If its operating quality decreases at all, the decrease is proportional to the severity of the failure. Diving equipment, especially those pieces which are high availability or safety-critical systems, must have a high fault tolerance. The ability to maintain functionality when portions of a system break down is referred to as 'graceful degradation', as opposed to a small failure causing total breakdown. The diver must also be fault tolerant, a state that is achieved by competence, situational awareness and fitness to dive, .
Physiological variables
Task loading, nitrogen narcosis, fatigue, and cold can lead to loss of concentration and focus, reducing situation awareness. Reduced situation awareness can increase the risk of a situation that should be manageable developing into an incident where damage, injury or death may occur.
A diver must be able to survive any reasonably foreseeable single equipment failure long enough to reach a place where longer-term correction can be made. The solo diver can not rely on team redundancy, and must provide all the necessary emergency equipment indicated as necessary by the risk assessment. On the other hand, a team can reduce risk to an acceptable level in most cases by distributing redundancy among its members. However, the effectiveness of this strategy is tied to team cohesion and good communication.
No gender-specific traits have been identified which require design of tasks and tools exclusively for female divers. Fit of diving suits must be tailored to suit the range of human shapes and sizes, and most other equipment fits all sizes, is adjustable to suit all sizes, or is available in several sizes. A few items are designed specifically for female use, but this is often more a fine tuning for comfort or cosmetic styling than an ergonomically functional difference. Female divers are reported, on average, to experience greater difficulty in performing five tasks of recreational diving: carrying heavy equipment on shore, putting on the scuba set, underwater orientation, underwater balance, and trim and descent. The first two are related to lifting large, heavy and bulky equipment. Balance and trim could be related to buoyancy and weight distribution, but insufficient data is available to specify a remedy.
There is a relative growth in the older sector of recreational diver demographics. Some are newcomers to the activity and others are veterans continuing a long career of diving activity. They include older female divers. More research is needed to establish the implications of age and sex-related variations on human factors and safety issues.
Breathing apparatus
The breathing apparatus must allow the diver to breathe with minimal added work of breathing, and minimum additional dead space. It should be comfortable to wear, and not cause stress injury or allergic reactions to its materials. It must be reliable and not require constant attention or adjustment during a dive, and performance should degrade gradually in the event of malfunctions, allowing time for corrective action to be taken with minimum risk. When more than one breathing gas mixture is available, the risk of selecting a gas unsuitable for the current depth must be minimised.
Demand valves
Holding the scuba mouthpiece between the teeth can cause jaw fatigue on a long dive. The loads that cause this fatigue can be reduced by using smaller second stages, different hose lengths and routing, angled swivels, and improved mouthpiece design, which may include customised bite grips. Allergic reactions to mouthpiece materials are less common with silicone rubber and other hypoallergenic materials than with natural rubber, which was commonly used in older equipment. Some divers experience a gag reflex with mouthpieces that contact the roof of the mouth, but this can be corrected by fitting a different style of mouthpiece.
Purging the second stage is a useful function to clear water from the interior. The purge button should function only when pressed, and should be powerful enough to sufficiently clear the chamber while not blowing its contents down the diver's throat. Cracking pressure is the pressure difference over the diaphragm needed to open the second stage valve. This should be low but not excessively sensitive to water movement or orientation. Once open with gas flowing, the gas flow often produces a slight increase in the pressure drop in the demand valve. This helps hold the demand valve open during inhalation, effectively reducing the work of breathing, but making the regulator more susceptible to free-flow. In high performance models, the user can adjust these sensitivity settings.
The exhaust valve should offer the minimum resistance to exhalation, including a minimum opening pressure difference, and low resistance to flow through the opening. It should not easily block or leak due to foreign matter such as vomit. Exhaust gas flow should not be too distracting or annoying to the diver in a normal diving posture. Flow should be directed away from the faceplate of the mask and bubbles should not flow directly over the ears.
Work of breathing
Breathing effort should be reasonable in all diver attitudes. The diver can rotate in three axes, and may need to do so for a significant period including several breaths from any arbitrary orientation. The DV should continue to function correctly throughout the maneuvers, though some variation in breathing effort is inevitable. Breathing performance testing for compliance to standards is generally done facing forward and facing down. Manual adjustment of the inhalation valve spring may be available, and can help if an unusual orientation must be maintained for a long period.
Hose routing
Scuba divers must be able to easily provide emergency gas to other scuba divers who are diving as part of the same group, which can be made easier or more difficult by the handedness of the regulator, the hose length, and the hose routing. Different configurations are used for specific circumstances. For example, the "long hose" arrangement is used to facilitate gas sharing when swimming in single file through a restriction. There are hose routings that have been standardised to a reliable system.
Rebreathers
Rebreather equipment removes carbon dioxide from exhaled gas and replaces it with oxygen, allowing the diver to breathe the gas again. This can be done in a self-contained system carried by the diver, in a system where the scrubber is carried by the diver and gas is supplied from the surface, or where the gas is returned to the surface for recycling. The power to circulate gas in the loop can be the lung power of the diver, energy from the supply gas pressure, or externally powered booster pumps. Scuba rebreathers tend to circulate by lung power, and the work of breathing can make up a significant part of diver effort at depth; in extreme circumstances it may exceed the capacity of the diver without additional workload. The position of the counterlungs and the orientation of the diver in the water, can have a significant effect on work of breathing, as can the restriction of flow between the diver's teeth.
Using two scrubber canisters in series can provide a level of redundancy in that a fault in one that allows carbon dioxide breakthrough will not necessarily directly affect the other. It is also possible to repack just the first scrubber after a short dive, and may be possible to also change the order so that the freshest scrubber is last in the circuit. Mounting the counterlung across the diver between the scrubbers can eliminate transverse shifts in the centre of buoyancy during the breathing cycle, and also mounting it longitudinally in line with the lungs eliminates longitudinal buoyancy shifts during the breathing cycle. The counterlung could be mounted across the back or across the chest.
A wide variety of rebreather types are used in diving because of the highly variable requirements in different situations. A diving rebreather is safety-critical life-support equipment – some modes of failure can kill the diver without warning, some others require immediate appropriate response for survival.
Some rebreathers have control systems which will lock out if they do not complete a satisfactory pre-dive test, but others which may be used for cave diving, where the inability to start a dive may prevent the diver from exiting from a cave in which they have surfaced in a space isolated from the exit by a water-filled passage, will not prevent the diver from starting a return dive, but will warn them of the problems detected, as it may be possible to escape by operating the rebreather manually.
Mouthpiece retaining straps
Rebreather diving incidents commonly involve an inappropriate breathing gas, which can result in loss of consciousness, water aspiration and drowning. Water aspiration may be delayed by use of a full-face mask or a mouthpeice retaining strap. According to a study of military rebreather accidents, the number of fatalities was low where mouthpiece retaining straps were used. The availability of a tethered dive buddy also helped ensure timely rescue.
Snorkels
A separate snorkel, or tube snorkel, used for freediving and swimming at the surface on scuba, typically comprises a curved tube for breathing and a means of attaching the tube to the head of the wearer. The tube has an opening at the top and a mouthpiece at the bottom. Snorkels are classified by their dimensions and by their orientation and shape. The length and the inner diameter (or inner volume) of the tube are important ergonomic considerations when matching a snorkel to the requirements of its user. The orientation and shape of the tube must also be taken into account when matching a snorkel to its use while seeking to optimise ergonomic factors such as low drag through the water, airflow, water retention, interrupting the field of vision, work of breathing, and dead space. The collapsible snorkel is intended for scuba divers who do not need a snorkel on every dive, but may find it occasionally useful. It can be folded up and stored in a pocket until it is needed.
Some snorkels have a sump and drain valve at the lowest point to help clear the snorkel and drain the remnant volume of water in the snorkel out of the direct air passage. The effectiveness of these has not been clearly established. These valves have a tendency to fail if infrequently used, stored for long periods, through environmental fouling, or owing to lack of maintenance. Many also slightly increase the flow resistance of the snorkel, retain a small amount of water in the tube after clearing, or both.
Dead space
Mechanical dead space of diving breathing apparatus is the volume in which the exhaled breathing gas is immediately inhaled on the next breath, increasing the necessary tidal volume and respiratory effort to get the same amount of usable breathing gas, increasing the accumulation of carbon dioxide from shallow breaths, and limiting the maximum volume of fresh or recycled gas in a breath. It is in effect an external extension of the physiological dead space.
The importance of minimising dead space volume is greater when the work of breathing is large, as work of breathing can also be a limiting factor in gas exchange. This becomes critical at high ambient pressures when the density of the breathing gas is high. Lower density breathing gas diluents help mitigate this problem.
Masks and helmets
Diving masks and helmets provide air space between the eyes and a transparent window to allow the diver a clear view underwater.
Internal volume
The internal volume of masks and helmets affects buoyancy and trim, and dead space, which affects gas exchange and work of breathing.
The volume of dead space is important for full-face masks and helmets, but not relevant to half masks as they are not part of the breathing passage. For breathhold diving, the mask internal volume must be equalised from the single breath in the diver's lungs, so a small volume is highly desirable, but scuba divers have sufficient air available that this is not a problem.
Large internal volume half-masks tend to float up against the nose, which is uncomfortable and becomes painful over time. The trend is towards low volumes and wide fields of vision, which requires the viewport to be close to the face. This makes it difficult to design a frame and nose pocket that will accommodate the full range of face shapes and sizes. Wide and high-bridged noses and very narrow faces are a particular problem. The clearance between the viewport and eyes should account for the eyelashes when blinking.
Full-face masks have larger internal volumes, but they are strapped on more securely and the load is carried by the neck. This load is small enough to be easily accommodated by most divers, though it may take some time to get used to it, and a lower volume is more comfortable. A large volume may adversely affect diver trim and necessitate moving or adding ballast weight to compensate.
Helmet buoyancy
The weight of a lightweight demand helmet in air is about 15 kg. Underwater it is nearly neutrally buoyant so it is not an excessive static load on the neck. The helmet is a close fit to the head and moves with the head, allowing the diver to aim the viewport using head movement to compensate for the restricted field of vision.
Free-flow helmets compensate for a potentially large dead space by a high gas flow rate, so that exhaled gas is flushed away before it can be rebreathed. They tend to have a large internal volume, and be heavier than demand helmets, and usually rest on the shoulders, so do not move with the head. As there is no need for an oro-nasal inner mask, they usually have a large viewport or several viewports to compensate for the fixed position. The diver can move the head inside the helmet to a limited extent, but to look around further, the diver must rotate the torso. The view downwards is particularly restricted, and requires the diver to bend over to see the area near the feet. Buoyancy may be compensated by direct weighting of the helmet and corselet, or by a jocking harness and indirect weighting.
Seal
The mask must form a watertight seal around the edges to keep water out, regardless of the attitude of the diver in the water. This seal is between the elastomer skirt of the mask and the skin of the face. The fit of a mask affects the seal and comfort and must account for the variability of face shapes and sizes. For half masks, this is achieved by the very wide range of models available, but in spite of this some faces are too narrow or noses too large to fit comfortably. This is less of a problem with full-face masks and less again with helmets. However, these are affected by other factors like overall head size and neck length and circumference, so there is still a need for adjustment and different size options.
Face and neck seals may be compromised by hair passing under the seal between the rubber and skin, and the amount of leakage will depend on the amount of hair and the position of the compromised part of the seal. Divers with large amounts of facial hair can usually compensate adequately on open circuit by occasional exhalation through the nose to clear the mask, but with a rebreather the gas used for mask clearing is lost from the circuit.
Equalising
Two aspects of equalising the pressure in gas spaces are influenced by mask and helmet design. These are equalising the internal space of the mask or helmet itself, and equalising the ears. Equalising the internal space of a half mask is normally achieved through the nose, and equalising the ears requires a method to block the nostrils. This is relatively easy to do with half-masks, where the diver can usually pinch the nostrils closed through the rubber of the mask skirt.
Helmets and most full-face masks do not allow the diver finger access to the nose, and various mechanical aids have been tried with varying levels of comfort and convenience.
Vision
The field of vision of the diver is reduced by opaque parts of the helmet or mask. Peripheral vision is more reduced in the lower areas due to the size of the demand valve. Helmet design is a compromise between low mass and inertia (with a smaller interior volume and restricted field of vision), and large viewports that lead to a larger interior volume. A viewport close to the eyes provides a better view for the same area, but this is complicated because of the varying nose sizes of divers and the need for clearance for the oro-nasal mask. Curved viewports can introduce visual distortions that reduce the ability to judge distance, and almost all viewports are made flat. Even a flat viewport causes some distortion, but it takes relatively little time to get used to this, as it is constant. Spherical port surfaces are generally used in newer atmospheric suits for structural reasons, and work well when the interior volume is large enough. They can be made wide enough for adequate peripheral vision. Field of vision in helmets is affected by the mobility of the helmet. A helmet directly supported by the head can rotate with the head, allowing the diver to aim the viewport at the target. In this case, however, peripheral vision is constrained by the dimensions of the viewport, the weight in air and unbalanced buoyancy forces when immersed must be carried by the neck, and inertial and hydrodynamic loads must also be carried by the neck. A helmet fixed to a breastplate is supported by the torso, which can safely support much greater loads, but it cannot rotate with the head. The entire upper body must rotate to direct the field of vision. This makes it necessary to use larger viewports so the diver has an acceptable field of vision at times when rotating the body is impractical. The need to rotate the head inside the non-rotatable helmet requires internal clearance, therefore a larger volume, and consequently a greater mass of ballast.
Optical correction is another factor that is considered in mask and helmet design. Contact lenses can be worn under all types of masks and helmets. Regular spectacles can be worn in most helmets, but cannot be adjusted during the dive. Corrective lenses can be glued to the inside of half-masks and some full-face masks, but the distance from the eyes to the lenses may not be optimal, and some correction may be needed to compensate for the increased distance from the cornea to the lens. Bifocal arrangements are available, mostly for far-sightedness, and may be necessary with older divers to allow them to read their instruments. Defogging of bonded lenses is the same as for plain glass. Some dive computers have relatively large font displays, and adjustable brightness to suit the ambient lighting.
An open circuit breathing apparatus produces exhalation gas bubbles at the exhaust ports. Free-flow systems produce the largest volumes, but the outlet can be behind the viewports so it does not obscure the diver's vision. Demand systems must have the second stage diaphragm and exhaust ports at approximately the same depth as the mouth and lungs to minimise work of breathing. To get consistent breathing effort for the range of postures the diver may need to assume, this is most practicable when the exhaust ports and valves are close to the mouth, so some form of ducting is required to direct the bubbles away from the viewports of helmet or mask. This generally diverts exhaust gases around the sides of the head, where they tend to be rather noisy as the bubbles rise past the ears. Closed circuit systems vent far less gas, which can be released behind the diver, and are significantly quieter. Diffuser systems have been tried, but have not been successful for open circuit equipment, though they have been used on rebreathers, where they improve stealth characteristics.
The inside surface of the viewport of a mask or helmet tends to be prone to fogging, where tiny droplets of condensed water disperse light passing through the transparent material, blurring the view. Treating the inside surface with a defogging surfactant before the dive can reduce fogging. Fogging may occur anyway, and it must be possible to actively defog, either by rinsing with water or by blowing dry air over it until it is clear. There is no supply of dry air to a half-mask, but rinsing is easy and only momentarily interrupts breathing. A spitcock may be provided on standard helmets for rinsing. Demand helmets generally have a free-flow supply valve that directs dry air over the inside of the faceplate. Full-face masks may use either rinsing or free-flow, depending on whether they are intended primarily for scuba or surface-supply diving.
Security
Masks held in place by adjustable straps can be knocked off or moved from the correct position, allowing water to flood in. Half masks are more susceptible to this, but because the diver can still breathe with a flooded half mask this is not considered a major issue unless the mask is lost. Full-face masks are part of the breathing passage, and need to be more securely supported, usually by four or five adjustable straps connected at the back of the head. It is still possible for these to be dislodged, so it must be possible for the diver to refit them sufficiently to continue breathing with their hands in cold-water gloves. On the other hand, the regulator is fixed to the mask so the mask is not easily lost and can be retrieved in the same way as a regulator second stage. Helmets are much more securely attached, and it is considered an emergency if they come off the head, as it is difficult for the diver to rectify the problem underwater, though it is usually still possible to breathe carefully if the free-flow valve is opened and the helmet held over the head with the bottom opening level.
Cylinders
When using multiple gas sources and mixtures it is important to avoid confusing the gas mix in use and the pressure remaining in the various cylinders. The cylinder arrangement must allow access to cylinder valves when in the water. Use of the wrong gas for the depth can have fatal consequences with no warning. High task loading for technical divers can distract from checking the mix when switching gas. It is important to check that each cylinder is the correct gas and is mounted in the right place, to positively identify the new gas at each gas switch, and to adjust the decompression computer to allow for each change in gas for correct decompression. Some computers automatically change based on data from integrated pressure transducers, but still require correct pre-dive setting of gas mixes.
A back-mounted single cylinder configuration is stable on the diver in and out of the water, and is compact and acceptably balanced. However, some divers have difficulty reaching the valve knob, which is behind the back, particularly when the cylinder is mounted relatively low on the harness, or the suit is thick or tight. Back-mounted twin cylinders with an isolation manifold are also stable in and out of the water. They are compact, heavy, and acceptably balanced for most divers. Some divers have difficulty reaching the valve knobs behind the back. This can be a problem in a free-flow or leak emergency, where a large volume of gas can be lost due to inability to access knobs quickly to shut down the cylinder. The weight and buoyancy distribution may be top heavy for some divers. In back-mounted independent doubles, gas is not available if a cylinder valve must be shut down. The side-mount emergency options of and are also not available. Flexible valve knob extensions on back mount sets are not very satisfactory and not very reliable, and are an additional snag risk. Pony cylinders for bailout or decompression gas clamped to the main gas supply put the valve where it cannot be seen, and may be difficult to reach. They are reasonably compact and manageable out of the water. Sling mount bailout and decompression cylinders allow easy access to the valve and allow the visual checking of labels during gas switching. Up to four sling cylinders are reasonably manageable with some practice.
Alternative configurations include an inverted single or manifolded twin cylinders. These have valves at the bottom which are more reachable, but are more vulnerable to impact damage. Custom hose lengths are needed, and hose routing will be different. This arrangement is used by firefighters, and has also been used by military divers. Weight and buoyancy distribution may be bottom heavy for some divers, and may adversely affect trim. This arrangement is also used for the gas cylinders on some rebreather models. Side mounts provide much easier valve access, and it is possible to see the top of each cylinder to check the label when switching gas, which allows confirmation of correct gas. It is possible to hand off a cylinder when donating gas to another diver, so a long hose is not needed.
Cylinder buoyancy
The material and pressure rating of cylinders affects convenience, ergonomics, and safety. Aluminum alloy and steel are the two commonly available materials that are most often used for scuba cylinders. Their strength to weight ratio allows the manufacture of scuba cylinders that are near neutral buoyancy when empty. Cylinders that require a buoyancy compensator for support when they are empty can be unsafe, since it could be necessary to ditch breathing gas to regain buoyancy in the event of a buoyancy compensator failure. Cylinders that are buoyant when full require ballasting to make them manageable underwater. This kind of cylinder is usually a fibre wound composite cylinder, which are expensive, relatively easy to damage, and usually have a shorter service life. They tend to be used for cave diving when they must be carried through a difficult route to get to the water. Buoyancy control is easier, more stable, and safer when the gas volume needed to achieve neutral buoyancy is minimised, particularly at the end of a dive during ascent and decompression. The need for a large volume of gas in the buoyancy compensator during ascent increases risk of an uncontrolled buoyant ascent during decompression.
For stage drops, sidemount diving where the cylinders will be pushed ahead of the diver for long distances, and where a cylinder may be handed off to another diver, it is particularly convenient if the cylinder has nearly neutral buoyancy during these maneuvers, as this has the least immediate impact on the buoyancy and trim of the diver. This convenience reduces task loading and improves safety.
Diving suits
Diving suits are worn for protection from the environment. In most cases this is to keep the diver warm, as heat loss to water is rapid. There is a trade-off between insulation, comfort, and mobility. When diving in the presence of hazardous materials, the diving suit also serves as personal protective equipment to limit exposure to those materials.
Wetsuits
Wetsuits rely on a good fit to work effectively. They rely on the low heat conductivity of the gas bubbles in the neoprene foam of the suit, which slows heat loss. If the water inside the suit can be flushed out and replaced by cold water, this insulating function is bypassed. Movement of the diver tends to move the water in the suit around mostly where it is present in thick layers, and if this water is forced out it will be replaced by cold water from outside. A close fit reduces the thickness of the layer of water and makes it more resistant to flushing. A suit that is too tight can also cause problems. It could restrict movement and increase the diver's work of breathing. The gas bubbles in the neoprene foam will compress at depth, reducing insulation as the diver gets deeper. Semi-dry suits attempt to address this issue by making it more difficult for water to enter and leave the suit, but are still most effective when they are close-fitting.
Dry suits
Dry suits rely on staying dry inside and maintaining a limited volume of gas distributed through the thermal undergarments. The volume of gas needed is fairly constant, but it expands and contracts due to pressure variations as the diver changes depth. Suit squeeze is caused by insufficient gas in the suit, and will reduce flexibility of the suit and restrict the diver's freedom of motion. This could prevent the diver from reaching critical equipment in an emergency. Gas is added manually by pressing a button to open the inflation valve, which is normally in the central chest area where it can easily be reached by both hands and is clear of the harness and buoyancy compensator. High flow rates are neither necessary nor desirable, as they could lead to over-inflation, particularly if the valve sticks open due to freezing. Over-inflation causes an uncontrollable rapid ascent if not corrected. Dumping of suit gas is only possible when the dump valve is above the gas to be dumped. During ascent, the diver has several things to monitor, so an adjustable automatic exhaust valve which provides hands-free operation helps reduce this task loading.
If the dry suit is flooded, thermal insulation is lost which may make it necessary to abort the dive. Buoyancy can also be lost, a problem that can countered by ditching ballast, inflating the buoyancy compensator if it is large enough, or deploying a DSMB or small lifting bag. The extra weight of the water can make it difficult to exit the water, but this can be mitigated by having ankle dumps or cutting the suit to allow water drainage.
The ability of the diver to reach the cylinder valve can be constrained by the suit and personal joint flexibility of the diver. Back-mount configurations with valves up are particularly difficult to reach. This can cause delays in reacting effectively to some emergencies. This is partly a suit issue and partly a cylinder configuration issue.
The combination of suit and helmet can further constrain movement. Considerable effort may be necessary to overcome the encumbrance of the suit so it can take longer to complete complex tasks, in an environment that is already non-conducive to dexterity or heavy labour. This was particularly noticeable on the standard diving suit. Wrist and neck seals are commonly available in latex rubber, silicone rubber, and expanded neoprene. Some divers are allergic to latex, and should avoid latex seals.
Dry suits can be effective for protection against exposure to a wide range of hazardous materials, and the choice of suit material should take into account its resistance to the known contaminants. Hazmat diving often requires complete isolation of the diver from the environment, necessitating the use of dry glove systems and helmets sealed directly to the suit.
The suit should allow sufficient freedom of movement to swim, work, and reach all necessary accessories and controls when worn over undergarments suitable for the water temperature, without having excess internal volume, particularly in the legs. Excess leg length and loose fit can cause the boots to float off the feet, followed by a loss of ability to swim, and orientate correctly, which can be dangerous. The seals should be tight enough to be reliable without restricting blood flow, particularly at the neck.
The operation and skill requirements for the safe use of dry suits has become fairly standardised, so although initial training is considered essential, switching between makes and models does not usually require retraining.
Hot water suits
Hot water suits are often used for deep dives when breathing mixes containing helium are used. Helium has a higher heat conductivity than air, but has a lower specific heat. The expansion of gas in the diving regulator causes intense cooling, and the chilled gas is heated to body temperature and humidified in the alveoli, which causes rapid heat loss from the body by conduction and evaporation. The amount of heat loss is proportional to the mass of gas breathed, which is proportional to ambient pressure at depth. This compounds the risk of hypothermia already present in the cold temperatures found at these depths.
Hot water suits are usually one piece suits made of foamed neoprene with a zipper on the front of the torso and on the lower part of each leg. They are similar to wetsuits in construction and appearance, but do not fit as closely by design; they are not as thick because they only need to temporarily retain and guide the flow of the heating water. The wrists and ankles of the suit must allow water to flush out of the suit as it is replenished with fresh hot water from the surface. Gloves and boots are worn which receive hot water from the ends of the arm and leg hoses. If a full-face mask is worn, the hood may be supplied by a tube at the neck of the suit. Helmets do not require heating. Breathing gas can be heated at the helmet by using a hot water shroud over the helmet inlet piping between the valve block and the regulator, which reduces heat loss to the breathing gas.
Heated water in the suit forms an active insulation barrier to heat loss, but the temperature must be regulated within fairly close limits. If the temperature falls below about 32 °C, hypothermia can result, and temperatures above 45 °C can cause burn injury to the diver. The diver may not notice a gradual change in temperature, and could enter the early stages of hypo- or hyperthermia without noticing. The suit must be loose fitting to allow unimpeded water flow, but this causes a large transient volume of water (13 to 22 litres) to be held in the suit, which can impede swimming due to the added inertia in the legs.
Hot water suits are an active heating system; they are very effective while they are working correctly, but if they fail, they are very ineffective. Loss of heated water supply for hot water suits can be a life-threatening emergency with a high risk of debilitating hypothermia. Just as an emergency backup source of breathing gas is required, a backup water heater is also an essential precaution whenever dive conditions warrant a hot water suit. If the heater fails and a backup unit cannot be immediately brought online, a diver in the coldest conditions can die within minutes. Depending on decompression obligations, bringing the diver directly to the surface could be equally deadly.
The diver will usually wear something under a hot water suit for protection against scalding, chafe and for personal hygiene, as hot water suits may be shared by divers on different shifts, and the interior of the suit may transmit fungal infections if not sufficiently cleaned. Wetsuits can prevent scalding of the parts of the body they cover, and thermal underwear can protect against chafe and keep the standby diver warm at the surface before the dive.
The hot water supply hose of the umbilical is connected to a supply manifold at the right hip of the suit, which has a set of valves to allow the diver to control flow to the front and back of the torso and the arms and legs, and to dump the supply to the environment if the water is too hot or too cold. The manifold distributes the water through the suit via perforated tubes.
Some initial training in the safe and effective use of hot water suits is considered necessary, but the skills are quickly learned and easily transferable between makes and the arrangement is fairly standard.
Atmospheric suits
The physiological problems of ambient pressure diving are largely eliminated by isolating the diver from the water and hydrostatic pressure in an atmospheric suit. However, dexterity problems with manipulators on atmospheric diving suits reduce their effectiveness for many tasks. The joints of atmospheric suits allow walking but are not suitable for swimming.
The suit must maintain constant volume during articulation, as a variable volume would require additional effort to move from a lower volume geometry to higher volume due to the large pressure difference. A range of user sizes can be accommodated by adding spacers between components, but the extra joints increase the likelihood of leaks. Alternative parts with different lengths that require moving high-pressure seals to be split and reconnected may need to be pressure tested before each use.
The work required to overcome friction in the pressure-resistant joint seals, inertia of the limb armour, and drag of the bulky limbs moving through the water are major constraints on agility and limit the ways the diver can move. However, buoyancy control is relatively simple, as the suit is mostly incompressible and the life support system is closed so there is no weight change due to gas consumption.
Although the pressure hull of the suit is often made from metals with high heat conductivity, insulating the diver is largely a matter of wearing clothing suitable for the internal air temperature, and insulating the shell away from the moving parts of joints is fairly straightforward. The air is recycled through the scrubber, which will heat it slightly through the exothermic chemical reaction that removes carbon dioxide.
The helmet is rigidly connected to the torso of the suit, which limits the field of vision. This can be partly compensated by using a nearly hemispherical dome viewport.
Atmospheric diving suits are still an emerging technology, and differ considerably, so specialist training is required for each model.
Harness
The surface-supplied diver's harness is an item of strong webbing, and sometimes cloth, which is fastened around a diver over the exposure suit. It must allow the diver to be lifted without risk of falling out of the harness. It also provides support for the bailout gas cylinder, and may carry the ballast weights, a buoyancy compensator, the cutting tool, and other equipment. Several types are in use. Recreational scuba harnesses are mainly used to support the gas cylinders, buoyancy compensator and often the weights and small accessories, but are not normally required to function as a lifting harness. In professional diving, when the harness may also be used to lift the diver, it must be strong enough to support the diver and equipment without causing injury. Some discomfort is considered acceptable when lifting out of the water, as this is an emergency procedure.
Improper distribution of weight carried by the harness can cause discomfort and nerve pressure injury out of the water, and the weight of the harness including cylinders can be problematic for putting the set on for some divers.
Buoyancy control equipment
Because pressure varies rapidly with depth, buoyancy is inherently unstable and controlling it requires continuous monitoring and input from the diver. The instability is proportional to the volume of the gas required for neutral buoyancy, so the volume of gas required for neutral buoyancy should be kept as low as possible over the course of the dive.
Most of the weight change in a dive is due to gas use. Unless equipment is lost or abandoned, the maximum weight change is the consumption of all the gas in all the cylinders carried. The diver needs enough buoyancy volume to remain comfortably afloat before the dive starts. At the end of the dive there will be more buoyancy in reserve as a result of the gas consumption. However, too much reserve volume in the buoyancy compensator has the potential for contributing to an uncontrolled buoyant ascent.
In dry suits, gas is primarily intended for thermal insulation, and the additional buoyancy it creates is undesirable. Removing excess gas is only possible when there is an upward path from the gas to the venting point.
Automatic dump valve position is conventionally on the upper left sleeve, clear of the harness, but in easy reach of the diver at all times and at a natural high point for the most useful and likely trim positions for swimming, work, and particularly ascents. The gas will expand as a diver ascends, increasing the need to vent it. However, a body orientation that allows for sufficient venting during an ascent is inefficient for horizontal propulsion. On the other hand, maintaining an orientation with the feet kept higher means the diver loses the ability to vent and risks losing control of buoyancy. Ankle venting points can mitigate this, but they are not fitted as standard equipment as they have proven to be a common leak point. Diving suits should not be excessively baggy, to reduce the amount of trapped gas, but must be loose enough to allow freedom of movement and access for the feet to the boots. The problem can be exacerbated if the legs are baggy at the ankles and the boots are loose, as if they slip off the feet, all control of the fins, and transfer of power to the fins, is lost. Gaiters and ankle straps can reduce the volume of this part of a suit, and may also reduce hydrodynamic drag, while ankle weights require acceleration with every fin stroke.
Female divers are reported to have more difficulties with buoyancy and trim. This may be a consequence of a buoyancy distribution not well catered for by most harness, buoyancy compensator and weighting systems, possibly exacerbated by dry suit buoyancy distribution. Many manage with available equipment, but it may take longer to learn to effectively use less ergonomically matched equipment. A similar problem is reported with unusually small divers.
The operating skills for most types of single bladder buoyancy compensator are standardised and portable between models. Familiarisation is rapid and straightforward, and retraining is generally not required, though additional training is provided for adapting to sidemount because of the associated changes in breathing apparatus management. Twin bladder units require more adaptation of procedures, and are associated with more accidents due to human error, as there are more kinds of operator errors that can be made.
Weights
Weighting systems are needed to compensate for the buoyancy of the diver and buoyant equipment. The distribution of buoyancy and ballast affect diver trim, which influences propulsion efficiency breathing gas consumption.
Weight-belts of conventional design are fastened around the waist and load the lower back when the diver is trimmed horizontal. This can cause lower back pain, particularly when the weights are heavy to compensate for the buoyancy of a dry suit with thick undergarments. Weights supported by the harness distribute the load more evenly.
Ankle weights, used to improve trim, add inertia to the feet, which must be accelerated and decelerated with every fin stroke, requiring additional power input for finning and reducing propulsive efficiency. The ability to shed ballast weight is considered a safety feature for scuba diving. It allows the diver to achieve positive buoyancy in an emergency, but the inadvertent loss of ballast when the diver needs to control ascent rate is itself an emergency that can cause decompression illness.
The need to pull weights clear of other equipment when ditching in some orientations is additional task loading in an emergency. The weight belt can become caught in the harness and compound the diver's problems if the need to establish positive buoyancy is urgent.
Fins
Fin design is a compromise between propulsive efficiency and maneuverability. Monofins are the equipment of choice for deep apnea diving and for speed and endurance competitions. Breath hold spearfishers need more maneuverability while retaining the best reasonably practicable efficiency, and they mostly choose long bifins. Professional and recreational scuba and surface-supplied divers will sacrifice more efficiency for better maneuverability. Comfort issues and muscle or joint stress, particularly among less physically fit divers, may bias the choice towards softer fins that produce less thrust and maneuverability. Divers needing maximum maneuverability will usually choose stiff paddle fins which can be effective for reversing out of a tight spot but are inefficient for cruising using flutter kick. These fins work well with the frog kick, which is also less likely to shed vortices downward and disturb silty bottoms, so this style of fin is popular for cave and wreck penetration diving.
Experimental work suggests that larger fin blades are more efficient in converting diver effort to thrust, and are more economical in breathing gas for similar propulsive effect. Larger fins were perceived by the participating divers to be less fatiguing than smaller fins. For each kick stroke the mass of the fin must be accelerated once in each direction, so producing more thrust per stroke will waste less work on accelerations. Inertial effects increasing the work of finning are also caused by heavier fins, boots and ankle weights.
Attachment to the foot follows two basic options: an integral foot pocket enclosing the heel or an open heeled foot pocket with an elastic heel strap. Both systems allow full mobility of the ankle joint for bi-fins, but limit the motion for monofins. Full foot-pockets are softer and more comfortable on bare feet, and spread the loads more evenly, but are often unsuited to wearing over a thick or hard-soled boot capable of crossing rough rocky shores. Fin retainers may be necessary for security if the fit is loose. Open heel foot pockets can be matched with foot width when wearing a boot, and the heel-strap is selected or adjusted to fit. Fin straps may be of fixed or adjustable length. Fixed length straps are always the right length for a single user, and have fewer snag points, moving parts, and other components that can fail. Adjustable straps are quickly adaptable to the feet of different users, a major advantage for rental equipment.
Gloves
Glove fit is important for several reasons. Gloves that are too tight or thick restrict movement and require more effort to grip, which causes early fatigue. Reduced blood flow may cause cramping. Loose gloves may be ineffective against heat loss due to flushing, and may reduce dexterity due to excess bulk.
There is a conflict between insulation and dexterity, and the reduction of tactile sense, grip strength, and early fatigue due to thick gloves or chilled hands. The diver can tolerate greater heat loss through the hands if the rest of the diver is warm, but in some cases such as diving in near-freezing water or where the air temperature at the surface is below freezing, the risk of frostbite or non-freezing cold injury necessitates the use of gloves most of the time. For safety-critical equipment, dexterity can be the difference between managing a problem adequately, or a situation deteriorating beyond recovery. Simple, large control interfaces such as oversize knobs and buttons, large clips, and tools that can be gripped by a heavily gloved hand can reduce risk significantly.
In very cold water there are two problems causing loss of dexterity. The chilling of hands and fingers directly causes loss of feeling and strength of the hands, and thick gloves needed to reduce chilling also reduce the sensitivity of the fingertips, making it more difficult to feel what the fingers are doing. Thick gloves also make the fingertips wider and thicker and a poorer fit to components designed to be used by gloveless hands. This is less of a problem with gloves where the fingertips have a reduced thickness of cover over the contact surface, but few neoprene gloves have this feature. The fingertips of the thumbs and forefingers are most affected, and also wear out faster than the rest of the glove. Some divers wear a thinner, tougher, work glove under the neoprene insulating glove, and cut the tips off the thumbs and forefingers of the neoprene gloves to expose the inner gloves as a workable compromise. Dry gloves allow the diver to tailor the inner insulating glove to suit the task. Insulation can be thicker where it affects dexterity least, and thinner where more sensitivity is needed.
Long term grip strength is reduced by fatigue. If the glove requires effort to close the hand to hold an object, this will eventually tire the hand, and grip will weaken sooner than when affected by cold alone. This is mitigated by gloves with a preform to fit a partly closed hand, and by more flexible glove materials.
Lifting bags
Surface-supplied gas panels
Breathing gas supplied to divers from the surface is routed through a surface control manifold and the gas panel, and may also pass through a manifold in an open or closed diving bell. The surface gas panel may be operated by the diving supervisor or a designated gas man, and the bell panel is the responsibility of the bellman. The gas panels are arranged so that it is clear to the operator which valves and gauges serve each diver. The surface standby diver may be supplied from an independent panel with independent gas supplies, so the standby diver is isolated from gas supply problems that may affect the working divers. Gas panels may be integrated with voice communication equipment.
The gas panel should monitor the depth of each diver in order to provide the right supply pressure. This is done using the pneumofathometer gauge for each diver. It should control the flow rate for free-flow helmets, monitor the supply pressure of connected gasses, make it clear which supply is in use when changing between main and secondary, and confirm that the gas is breathable at the current depth of each diver. Additionally, it should display which part of the system is supplying which diver. Safe and reliable gas provision to the divers depends on the panel operator having a clear and accurate knowledge of the status of the valves and pressures at the panel. This is helped by arranging the components of the panel so that it is immediately obvious which components are dedicated to each diver, what the function of each component is, and the status of each valve. Quarter turn ball valves are generally used because it is immediately obvious from the handle position whether they are open or closed. The spatial arrangement of valves and gauges on the panel is usually either the same for each diver, or mirrored. All operable valves and gauges should be labeled, and colour or shape coding may be useful.
Communication systems
Diver communications are the methods used by divers to communicate with each other or with surface members of the dive team. In professional diving, diver communication is usually voice communications between a single working diver and the diving supervisor at the surface control point, and with the bell for bell operations. This is considered important both for managing the diving work, and as a safety measure for monitoring the condition of the diver. The traditional method of communication by line signals is now used in emergencies when voice communications have failed. Surface supplied divers also often carry a closed circuit video camera on the helmet which allows the surface team to see what the diver is doing and to be involved in inspection tasks. This can also be used to transmit hand signals to the surface if voice communications fails. Underwater slates may be used to write text messages which can be shown to other divers, Voice communication is the most generally useful format underwater, as visual forms are more affected by visibility, and written communication and signing are relatively slow and restricted by diving equipment.
Diver voice communication equipment does not work with a standard scuba demand valve mouthpiece, so scuba divers generally use hand signals are when visibility allows, and there are a range of commonly used signals, with some variations. These signals are often also used by professional divers to communicate with other divers. There is also a range of other special purpose non-verbal signals, mostly used for safety and emergency communications.
The interface between air and water is an effective barrier to direct sound transmission, and the natural water surface is a barrier to visual communication across the interface due to internal reflection. Hyperbaric speech distortion also hinders sound-based communication.
The process of talking underwater is influenced by the internal geometry of the life support equipment and constraints on the communications systems as well as the physical and physiological influences of the environment on the processes of speaking and vocal sound production. The use of breathing gases under pressure or containing helium causes problems in intelligibility of diver speech due to distortion caused by the different speed of sound in the gas and the different density of the gas compared to air at surface pressure. These parameters induce changes in the vocal tract formants, which affect the timbre, and a slight change of pitch. Several studies indicate that the loss in intelligibility is mainly due to the change in the formants.
The difference in density of the breathing gas causes a non-linear shift of low-pitch vocal resonance, due to resonance shifts in the vocal cavities, giving a nasal effect, and a linear shift of vocal resonances which is a function of the velocity of sound in the gas, known as the Donald Duck effect. Another effect of higher density is the relative increase in intensity of voiced sounds relative to unvoiced sounds. The contrast between closed and open voiced sounds and the contrast between voiced consonants and adjacent vowels decrease with increased pressure. Change of the speed of sound is relatively large in relation to depth increase at shallower depths, but this effect reduces as the pressure increases, and at greater depths a change in depth makes a smaller difference.
Helium speech unscramblers are a partial technical solution. They improve intelligibility of transmitted speech to surface personnel.
Instrumentation and displays
Diving instrumentation may be for safety or to facilitate the task being performed. Safety-critical information such as gas pressure and decompression status should be presented clearly and unambiguously.
A lack of standardised dive computer user-interfaces can cause confusion under stress. Computer lock-out at times of great need is a potentially fatal design flaw. The meaning of alarms and warnings should be immediately obvious. The diver should be dealing with the problem, not trying to work out what it is. Displays should allow for variations in visual acuity, and be readable with colour-blindness. Ideally, critical displays should be readable without a mask, or allow safe surfacing without a mask. There should not be too much distracting information on the main screen, and returning to the main screen should be automatic by default, or auxiliary screens should continue to display critical decompression data.
Dive computers are safety critical equipment, but there is very little formal training provided for their use. Models also vary considerably in operation, and are often not intuitive, so skills are not transferable when a new unit is used. The user manual is usually all that is available to learn from, and it cannot be taken underwater for convenient reference. Instrument consoles represent a concentrated source of information, and a large potential for operator error.
Dive computers provide a variety of visual dive information to the diver, usually on a LCD or OLED display. More than one screen arrangement may be selectable during a dive, and the primary screen will display by default and contain the safety critical data. Secondary screens are usually selected by pressing one or two buttons one or more times, and may be transient or remain visible until another screen is selected. All safety critical information should be visible on any screen that will not automatically revert within a short period, as the diver may forget how to get back to it and this may put them as significant risk. Some computers use a scroll through system which tends to require more button pushes, but is easier to remember, as eventually the right screen will turn up, others may use a wider selection of buttons, which is quicker when the sequence is known, but easier to forget or become confused, and may demand more of the diver's attention, :
Display and control units for electronically controlled closed circuit rebreathers have very similar requirements and problems to dive computers. This may be reduced when the rebreather controllers and backup dive computer are produced by the same manufacturer.
Head-up displays can be used to provide the diver with a view of critical information which is always visible. These can be mounted on the mask, or on the mouthpiece assembly. Head-up displays require special near-eye 0ptics to allow correct focus on the display. In conditions of very low visibility, a head-up display has the advantage that the diver's ability to see the display is not affected by turbidity. It also lets the diver monitor all displayed dive data without interrupting their work.
Cutting tools
The primary function of diver cutting tools is to deal with entanglement by lines or nets. The tool should be accessible to both hands, and should be capable of cutting the diver free from any entanglement hazard predicted at the dive site. Many divers carry a cutting tool as standard equipment, and it may be required by code of practice as default procedure. When entanglement risk is high, backup cutting tools may be required.
Dive lights
Dive lights may be needed to compensate for insufficient natural illumination or to restore colour. They may be carried in several ways depending on their purpose. Head mount lights are used by divers who need to use both hands for other purposes. With a head mount there is a greater risk of dazzling other divers in the vicinity, as the lights move with the diver's head. As such, this arrangement is more appropriate for divers who work or explore alone. Helmet mounts are appropriate for illuminating work which is monitored via a helmet-mounted closed circuit video camera. Hand-held lights can be directed by the diver independently of the direction the diver is facing and do not require any special mounting equipment. However, they occupy a hand and are at risk of being dropped unless they are clipped on. They are most suitable for incidental lighting, and where precise direction is useful. Glove or Goodman handle mount allows precise direction and allows the hand to perform some other tasks. Canister lights allow the light head to be held in either hand, on a Goodman handle, or looed over the neck to free both hands, and the cable prevents the light from falling far if dropped. It is possible and fairly common to carry more than one of these options. Where light is important for safety, the diver will carry backup lights.
Buddy lines
A buddy line is a line or strap physically tethering two scuba divers together underwater to prevent separation. They can also serve as a means of communication in low visibility conditions. It is usually a short length and may be buoyant to reduce the risk of snagging on the bottom. It does not need to be particularly strong or secure, but should not pull free under moderate loads, such as when used for line signals. Divers may communicate by rope signals, but may just use the line to attract attention before moving closer and communicating by hand signals. The disadvantage of a buddy line is an increased risk of snagging and entanglement, and the risk is increased with a longer or thinner line. Divers may need to disconnect the line quickly at either end in an emergency, which can be done via a quick-release mechanism or by cutting the line, both of which require at least one free hand. A velcro strap requires no tools for release and can be released under tension.
Clips and attachment points
Clips and attachment points should be reliable and must generally be operable by one hand with gloves suitable for the water temperature, without needing to see what is being done, as it may be dark, low visibility, or out of view. Single-hand operation is necessary where only one hand can reach. This is always preferable, as the other hand may be in use for something important. While unlikely, it is possible for most types of clip to become jammed closed, and if this may endanger the diver it should be possible to use an alternative method to disconnect, which does not involve special tools. Cutting loose using the diver's cutting tool is the standard.
A reliable clip is one that does not allow connection or disconnection by accident, instead requiring specific action by the operator to clip or unclip. Unreliable clips may cause loss of equipment or entanglement. Bolt snaps and screw-gate carabiners are examples of clips with a reputation for reliability. The carabiners are more secure, and may be load rated, but are less convenient to operate. Carabiners are approved for attaching the umbilical to a surface supplied diver's harness.
There are usually several attachment points provided on the diving harness or buoyancy compensator for securing accessories and additional diving cylinders. On technical harnesses these are often in the form of stainless steel D-rings or sliders with integral rings, and may be adjustable for position. Plastic D-rings are common on bulk-produced recreational buoyancy compensators, and are usually in fixed positions, held on by bar-tacked webbing straps or tabs, and are not replaceable. Professional harness is usually required to have at least one attachment point capable of lifting the diver out of the water. Attachment rings that are free to swing are less prone to snagging on the surroundings in tight spaces but are more difficult to clip onto one-handed when out of view.
Diver propulsion vehicles
A diver propulsion vehicle (DPV) is a powered device with an integral thruster used by scuba divers to increase their range underwater. Range is restricted by the amount of breathing gas that can be carried, the rate at which that breathing gas is consumed, and the power endurance and speed of the DPV. Time limits imposed on the diver by decompression requirements may also limit safe range in practice. DPVs have recreational, scientific and military applications. They have been produced in a range of configurations from small, easily portable scooter units with a small range and low speed, to faired or enclosed units capable of carrying several divers longer distances at higher speeds.
The most efficient position for towing behind is when the wake of the thruster bypasses the diver. This is usually achieved by using a tow leash from the DPV to a D-ring on the lower front of the diver's harness. The diver also holds a handle on top of the DPV with a dead-man switch that turns off power to the DPV as soon as the diver lets go of the handle. The DPV is commonly steered by one hand, leaving the other hand free for other tasks. This requires good static and dynamic balance of the DPV and diver to avoid excessive diver fatigue. Lights, cameras, navigation, and other instruments may be mounted on a DPV for convenience, but the diver should also carry backups for essential instruments in case the DPV must be abandoned in an emergency. Control of the DPV is additional task loading and can distract the diver. A DPV can increase the risk of a silt-out if the thrust is allowed to wash over the bottom.
DPV operation requires greater situational awareness than simply swimming, as some changes can happen much faster. Operating a DPV requires simultaneous depth control, buoyancy adjustment, monitoring of breathing gas, and navigation. Buoyancy control is vital for diver safety. The DPV has the capacity to dynamically compensate for poor buoyancy control by thrust vectoring while moving, but once it stops the diver may turn out to be dangerously positively or negatively buoyant if adjustments were not made to suit the changes in depth while moving. If the diver does not control the DPV properly, a rapid ascent or descent under power can result in barotrauma or decompression sickness.
Cameras
Underwater cameras are usually popular models encased in a watertight pressure housing. There are a few notable exceptions, such as the Nikonos and Sea & Sea ranges, in which the camera body was the pressure housing. Controls are generally operated by movable links penetrating the watertight case, each requiring reliable seals because they represent a possible leak. Compact and lightweight camera bodies with multiple controls packed into a small space tend to transform into bulky, heavy and expensive units when housed for moderately deep diving. The camera's controls must be operable using thick gloves in cold water. For most underwater photography, a camera that is close to neutral buoyancy will be easier to handle and have less disruptive effect on diver trim. Strobe arms incorporating incompressible buoyancy compartments are the preferred system, as they do not need to be adjusted for changes of depth.
Internal flash is problematic at anything except very close range, as it can cause backscatter in cloudy water, and is the major consumer of battery power at full power. External flash using optical coupling avoids hull penetrations and potential leaks, and video lights give a good preview of exposure, and also provide the diver with a high-power dive light that is already pointing in the right direction to record the scene. With more powerful video lights and low-light sensitivity cameras, flash may not be necessary.
Surface marker buoys
A surface marker buoy is towed to indicate the position of the diver. It should have sufficient buoyancy to reliably remain at the surface so it can be seen. If it is actively towed, it should not develop so much drag that the diver is unable to manage it effectively. The tow line may be a major source of drag (roughly proportional to its diameter); as such, a smaller, smooth line is preferable, and also fits on a more compact reel or spool. Smaller line may need to be of stronger and more abrasion-resistant material like ultra-high-molecular-weight polyethylene for acceptable durability.
A decompression buoy is deployed towards the end of the dive as a signal to the surface that the diver has started to ascend.This kind of buoy is not usually towed, so drag is not a problem. Visibility to a surface observer depends on colour, reflectivity, length above the water, and diameter. A low waterplane area has the advantage of reducing the variation of line tension as waves pass overhead, making it easier to maintain accurate depth under large swells during decompression stops. A larger buoy is more visible at the surface but will pull upward harder if the reel jams during deployment.
Distance lines and line markers, reels and spools
Distance lines are used for underwater navigation where it is either essential to mark the route out of the overhead environment, or necessary or desirable to return to a specific point. Lines are deployed from reels or spools, and may be left in place or recovered on the return. The design and construction of the reel have a large influence on handling during both deployment and recovery of line, which are major parts of the task loading of one of the divers in a wreck or cave penetration team. Good design can minimise effort of winding in the line, and an adjustable brake reduces risk of overruns and loose line in the water while laying the line, which is an entanglement hazard. Highly visible line helps reduce the risk of losing the line in bad visibility, and a near neutral buoyancy of the reel minimises the fatigue caused by carrying it in the hand for long periods. Matching the size of a reel or spool to its intended use allows easy recognition by feel and efficient storage.
Line markers are generally used on permanent guidelines to provide critical information to divers following the line. Slots and notches are used to wrap the line and secure the marker in place. Passing the line through the enlarged area at the base of the two slots allows the marker to slide along the line, or even fall off if brushed by a diver. To more securely fasten the marker, an extra wrap may be added at each slot. It must be possible to fit, interpret, and remove a line marker by feel in total darkness with the line under moderate tension. All of this must happen without dislodging the line. The basic function of these markers is fairly consistent internationally, but procedures may differ by region or team. The protocol for placement and removal should be well understood by the members of a specific team.
A dive reel comprises a spool to hold the line. It is coupled with a winding knob which rotates on an axle attached to a frame, with a handle to hold the assembly in position while in use. A line guide is almost always present to prevent line from unwinding unintentionally, and there is usually a method of clipping the reel to the diver's harness when not in use. Reels may be made from a wide variety of materials, but near neutral buoyancy and resistance to impact damage are desirable features. Reels may also be open or closed. This refers to the presence of a cover around the spool, which is intended to reduce the risk of line tangles on the spool, or line flipping over the side and causing a jam. To some extent this works, but if there is a jam the cover effectively prevents the diver from correcting it. Open reels allow easy access to free jams caused by overwinds or line getting caught between spool and handle, and allow visual checks on the line while winding it in. Reels should be easy to use and lockable to prevent unintentionally unrolling, and have sufficient friction to prevent overruns. Reels used for deploying DSMBs usually have a thumb release ratchet to allow free running deployment and to prevent unwinding when there is tension on the line at other times. A reel with a closed handle is less tiring to hold for long periods, particularly when wearing thick or stiff gloves.
Finger spools are a simple, compact, and low tech alternative to reels that are best suited to relatively short lengths of line. They are a pair of circular flanges with a hole in the middle, connected by a tubular hub, which is sized to use a finger as an axle when unrolling the line. The line is secured by clipping a bolt snap through a hole on one of the flanges and over the line as it leaves the reel. It is reeled in by holding the spool with one hand and simply winding the line onto the spool by hand. Spools are most suitable for reasonably short lines, up to about 50 m, as it becomes tedious to roll up longer lengths. The double end bolt snap for locking the line may also be used as an aid for winding it in, to avoid line abrasion of the fingers or gloves.
Equipment storage
While it is possible for a diver to put on and take off some items of equipment in the water, there is a greater risk of fitting them incorrectly or losing them, particularly when the water is a bit rough. Doing this in the surf is even more risky, and delays at the surface on a boat dive can let the divers drift off site. When possible, kit-up and pre-dive checks should be completed on shore or on the boat, and the kit-up area should facilitate this, or at least make it possible. For recreational diving charter boats, this gives preference to arrangements where each diver can safely and securely stow all their personal dive gear at the same place where they will be putting it on, and where it is not necessary for it to be handled by anyone else except at the diver's request, as unauthorised handling of another person's life-support equipment could have legal consequences if something goes wrong.
Boarding the boat after a dive may require equipment to be removed in the water, and this presents another set of hazards, and the associated risks of injury and damage to or loss of equipment, some of which may be avoided if the diver does not have to take off equipment in the water, and heavy equipment does not have to be lifted over the side of the boat with fragile dangling components exposed to snagging, impact, and crushing hazards by crew or passengers. The necessity to remove fins before climbing some ladders reduces the diver's ability to swim back to the boat if they drift away. When boarding an anchored boat, some way of keeping within reach of the boarding area while removing equipment is required, and it may be necessary to use both hands to ensure secure removal and hand-over of some equipment. Suitable handholds, clip-off points and trailing lines can facilitate this activity.
Diving chambers
Design and construction of pressure vessels for human occupancy are regulated by law, safety standards, and codes of practice. These specify safety and ergonomic requirements, airlock opening sizes, internal dimensions, valve types and arrangement, safety interlocks, pressure gauge types and arrangements, gas inlet silencers, outlet safety covers, seating, illumination, breathing gas supply and monitoring, climate control and communications systems. Other requirements are also specified for structural strength, permitted materials, over-pressure relief, testing, fire suppression and periodical inspection.
A closed bell design must allow access by divers wearing bulky diving suits and bailout sets appropriate for the depth. The amount of gas in the bailout set is calculated for a return rate of 10 metres per minute from the reach of the excursion umbilical. At greater depths, this may require twin sets of high pressure cylinders. It must also be possible for the bellman to hoist an unconscious diver through the lock. A flood-up valve may be provided to allow partial flooding of the bell, so that an unresponsive diver is partially supported by buoyancy while being maneuvered through the opening. Once suspended inside the bell, the water can be blown back down by adding gas. The internal volume must include enough space for divers and equipment including racks for the excursion umbilicals and the bell gas panel. On-board gas cylinders, emergency power packs, tools and hydraulic power supply lines do not have to be stored inside. Access while underwater is through a lock at the bottom, so that the internal gas pressure can keep the water out. This lock can be used for transfer to the saturation habitat, or a side lock can be provided. The side lock does not need to allow passage with harness and bailout cylinders as these are not carried into the habitat area and are serviced at atmospheric pressure.
The splash zone is the region where the bell passes through the surface of the water and where wave action and platform movement can cause the bell to swing around, which can be uncomfortable and dangerous to the occupants. To limit this motion a bell cursor may be used. This is a device used to guide and control the motion of the bell through the air and the splash zone near the surface, where waves can move the bell significantly. It can either be a passive system that relies on additional ballast weight or an active system that uses a controlled drive system to provide vertical motion. The cursor has a cradle which locks onto the bell and moves vertically on rails to constrain lateral movement. The bell is released and locked onto the cursor in the relatively still water below the splash zone.
A bell stage is a rigid frame that may be fitted below a closed bell to ensure that even if the bell is lowered so far as to contact the clump weight or the seabed, there is enough space under the bell for the divers to get in and out through the bottom lock. If all the lifting arrangements fail, the divers must be able to shelter inside the bell while awaiting rescue, and must be able to get out if the rescue is to another bell when the bell is resting on the seabed.
Each compartment of a hyperbaric system for human occupation has an independent externally mounted pressure gauge so that it is not possible to confuse which compartment pressure is being displayed. Where physically practicable, lock doors open towards the side where pressure is normally higher, so that a higher internal pressure will hold them closed and sealed.
Medical and supply lock outer doors generally open outwards due to space constraints, and therefore are fitted with safety interlock systems which prevent them from being opened with internal pressure above atmospheric. This helps avoid the possibility of human error allowing them to be opened while the inner lock is not sealed, as the uncontrolled decompression that would ensue would probably kill the occupants, and possibly also the lock operator.
Internal diameter of hyperbaric living compartments and deck decompression chambers is constrained by codes of practice for reasonable comfort for the occupants. For emergency transfer chambers, there may be overriding logistical constraints on size and mass.
Hyperbaric stretchers
A hyperbaric stretcher is a lightweight pressure vessel for human occupancy (PVHO) designed to accommodate one person undergoing initial hyperbaric treatment during or while awaiting transport or transfer to a treatment chamber. The stretcher should accommodate most divers without being excessively claustrophobic, be conveniently portable by a reasonable number of bearers, should fit into the available space in the transport likely to be used, and fit through the entry opening of the treatment chamber or lock onto the chamber for transfer under pressure. It should be possible to see and communicate with the person in the chamber, and the occupant should be able to breathe oxygen which is vented to the exterior to keep a constant internal pressure and limit the fire hazard. Breathing gas supplies should also be portable, and it should be possible to disconnect them for a short period when maneuvering in tight spaces.
A saturated diver who needs to be evacuated should be transported without a significant change in ambient pressure. Hyperbaric evacuation requires pressurised transportation equipment, and could be required in a range of situations. The pressure rating and locking mechanism of the evacuation chamber must be compatible with the saturation system it is to serve and the reception facility. This is because both transfers must be under pressure, and it may not be safe to start decompression during the evacuation.
Access equipment
Access equipment is the gear needed to get into and out of the water. In most cases, it refers to diving from a floating platform, but also applies to shore dives where access requires equipment.
Diving stages and wet bells
Diving stages and wet bells are open platforms used to lower the divers to the work site and to control the ascent and in-water decompression, and to provide safe and easy entry and exit from the water. Design must provide space for the working diver and possibly the bellman. They must be in positions where they are protected from impact during transit and prevented from falling out when above the water. The divers may be seated, but standing during transit is more common.
A stage must have a way to guide the umbilical from the surface tending point to the diver so the diver can be sure of finding the right way back to the stage. This can be provided by having the diver exit the stage on the opposite side to boarding, with the umbilical passing through the frame, but this is not infallible in bad visibility, and a closed fairlead is more reliable. Running the umbilical via the stage may also be needed to ensure the diver cannot approach known hazards, such as the thrusters of a dynamically positioned vessel.
A wet bell has an open-bottomed air space at the top, large enough for the diver and bellman's heads. This space can be used as a place of refuge in an emergency, where some breathing problems can be managed. The air space must be large enough for an unresponsive diver to be suspended by their harness with their head in the air space, as it may be necessary to remove an unresponsive diver's helmet or full-face mask to provide first aid. The bell is also provided with an on-board emergency gas supply, sufficient for any planned or reasonably foreseeable decompression, and a means of safely switching between surface and on-board gas supply. This necessitates an on-board gas distribution manifold and divers' umbilicals that are deployed from and stored on the bell, and someone to operate the panel and tend the working diver's excursion umbilical. The bellman does this, and also serves as standby diver. The buoyancy of the air space may have to be compensated by ballast, as the bell must be negatively buoyant during normal operation.
Diver ladders
For some applications, dive boat ladders that allow the diver to ascend without removing the fins are preferred. When there is a lot of relative motion between the diver and ladder, it can become difficult to safely remove fins, then get onto the ladder, and not lose the fins. A ladder that can be climbed with fins on the feet avoids this problem. A ladder that slopes at an angle of about 15° from the vertical reduces the load on the arms.
If a ladder must be climbed in full equipment, suitable handholds to brace the diver while climbing are necessary for safety. This also applies if the divers need to climb down a ladder wearing dive gear, and they may need to turn around at the top of the ladder. In the general case, the vessel will be moving in a seaway while the diver is boarding.
Dive platforms and diver lifts
A dive platform, or swim platform, is a near horizontal surface on a dive boat that gives more convenient access to the water than the deck. It may be large enough for several divers to use simultaneously, or just enough for a single diver. The platform may be fixed, folding, or arranged to lower divers into the water and lift them out again, in which case it is known as a diver lift. Most dive platforms are mounted at the stern, usually on the transom, at a height a short distance above the waterline. They are easily flooded by a following sea, and are self-draining.
Fixed and folding platforms are generally provided with ladders which can be folded or lifted out of the water when not in use. They are also equipped with steps or ladders from the platform to the deck, while lifting platforms may be sufficiently immersible for the divers to swim directly over the platform and stand up to be lifted to a level where they can walk off onto the deck. Lifts are commonly mounted on the transom, or on the side of the boat. Handrails while using steps, ladders and lifts, when crossing or waiting on the platform, or making adjustments to equipment are a valuable safety adjunct as the platform will often be moving when in use, and the divers will usually be encumbered by heavy and bulky diving equipment. Barriers to protect occupants from pinch point hazards may be necessary when there are moving parts. The utility of a lift is enhanced if the diver can use it without having to remove any equipment in the water or on the platform, so an upper position level with the working deck and sufficient space to walk onto the deck fully kitted is preferable.
Recovery of an incapacitated diver
Professional divers may be required to wear a harness suitable for lifting the diver out of the water in an emergency, and there will usually be an emergency recovery plan and the necessary extraction equipment and personnel available. Recreational divers are not usually required to make any special provisions for an emergency, but recreational diving service providers may have a duty of care to their customers to provide for reasonably foreseeable emergencies with practicable facilities. There may be a regional or membership organisation standard or code of practice. Recovering an incapacitated diver from the water and providing first aid on the boat would usually be considered an expected level of care from a professional service provider.
Recreational divers are not required to wear lifting rated harness, so other plans should be in place. These often necessitate removing equipment from the diver, and the risk of losing the equipment. Details of methods to recover a diver into a boat will vary depending on the geometry of the boat. Simply dragging a diver over the pontoon of an inflatable hull may work in many cases. Larger boats with higher freeboard may have lifting gear that can be used with a rescue sling.
Tools
Tools that are intended for use by divers should take into account the handicaps of the underwater environment on operator stability, mobility, and control, within the full range of conditions in which they are likely to be used. Buoyancy effects on tool and operator, water movement, and reduced sensory input can complicate underwater tool use. Use with gloves is common, and can be a problem when controls are small and clustered.
Tool bags, pockets and lanyards
Lanyards and clipping points can prevent the loss of tools and equipment like cameras, lights and cutting tools in mid-water or poor visibility, but can increase entanglement risk. Carrying heavy tools can compromise the diver's ability to accurately control ascent and descent rates, so it is common practice for professional divers to have their tools delivered in a bag lowered from the surface, or to transport them in a basket on the stage or bell which transports the diver to the underwater workplace. Tools do not have to be carried inside the pressurised volume of a closed bell, so the basket or rack can be on the bell stage or clump weight.
Pockets for small accessories are common on jacket-style buoyancy compensators. Wing buoyancy compensators generally do not have pockets, as the wing is behind the diver and the harness is usually fairly minimal, but pockets can be added to the waistbelt if there is space. They are supported by the webbing at the top and may be strapped around the thigh to prevent flapping. Cargo pockets on the diving suit are more popular with technical divers, and may be glued to the front or side of the thighs of the suit, or attached in similar positions to wetsuit shorts or a tunic worn over the main suit. Occasionally a chest pocket or internal key pocket may be provided. Sidemount divers may use a butt-pack, a clip-on bag worn behind the diver below the harness and buoyancy comprnsator, that is unclipped and brought forward for access. Position, size, shape, closures, and accessibility are important for the function of carrying equipment, and possible interference with other equipment should also be considered.
Tool bags serve a similar purpose and are available in forms which can be clipped to the diver's harness in a position where access is relatively convenient. Tool bags are used by technical divers for similar purposes to pockets, and professional divers use them to carry small sets of relatively light tools and components in clip-on bags, and heavier tools and components in independent bags which are set down when not being used for the carrying function. Lifting bags of appropriate size may be used to support part of the weight of a bag, heavy tool or installation component.
Checklists
Checklists for preparation of the dive and diving equipment are regarded as important safety tools, and are mandatory in some circumstances. There are several design factors which affect the effectiveness of checklists.
The design of a checklist should fit the purpose of the list. If a checklist is perceived as a top-down means to control behaviour by the organisational hierarchy it is more likely to be rejected and fail in its purpose. A checklist perceived as helping the operator to save time and reduce error is likely to be better accepted. This is more likely to happen when the user is involved in the development of the checklist.
Rae et al. (2018) define safety clutter as "the accumulation and persistence of 'safety' work that does not contribute to operational safety", and state that "when 'safety' rules impose a significant and unnecessary burden on the performance of everyday activities, both work and safety suffer".
An objective in checklist design that it should promote a positive attitude towards the use of the checklist by the operators. For this to happen it must be realistic, convenient and not be regarded as a nuisance. A checklist should be designed to describe and facilitate a physical procedure that is accepted by the operators as necessary, effective, efficient and convenient.
See also
Notes
References
Underwater diving equipment
Design
Ergonomics | Human factors in diving equipment design | [
"Engineering"
] | 18,174 | [
"Design"
] |
63,557,743 | https://en.wikipedia.org/wiki/Eyes%20of%20Sibiu | The Eyes of Sibiu (, ) are the iconic eyebrow dormers on the roofs of Sibiu's houses. Sibiu lies in Transylvania, a historical region of Romania. The eyes, which are a symbol and a tourist attraction of the city, have given Sibiu the nicknames of The City with Eyes, The City Where Houses Don't Sleep and the portmanteau Seebiu. They vary in shape – most of them are trapezoid-shaped, others having rounded or elongated forms.
In Romanian, they are called Ochii Sibiului, while in German they are known as die Augen von Hermannstadt, Hermannstadt being the German name of Sibiu.
History
Although the eyes originate from as early as the 15th century, most of them were built in the 19th century. They were most likely invented by a local of Sibiu, because they are widespread in the city and its surroundings. They are an element of Baroque architecture. Some of them were even built as late as the 20th century, after Sibiu became part of the Kingdom of Romania.
Purpose
There are legends, according to which the eyes were built to frighten the people, making them believe they are being watched. Their real purpose was to act as a ventilation system for the houses' attics. Nowadays, the eyes have become one of Sibiu's most famous symbols, making them a tourist attraction.
In 2017, the eyes became a symbol of Romania's anti-corruption fight, being used by the organisation Vă vedem din Sibiu ("We see you from Sibiu").
Spread
Apart from Sibiu itself, the eyes have also been built in the city's surroundings. Most of them are found in the Sibiu County. Some of them can also be found in other nearby places, like the cities of Brașov and Făgăraș, both located in the Brașov County.
Additionally, some examples which are probably unrelated can also be found in the city of Timișoara in western Romania. Similar eyebrow dormers can also be found on traditional rural Romanian houses or on cule in the historical region of Oltenia.
Gallery
See also
Council Tower of Sibiu
Sibiu Lutheran Cathedral
Pareidolia
References
Buildings and structures in Sibiu
Baroque architecture in Romania
Windows
Roofs | Eyes of Sibiu | [
"Technology",
"Engineering"
] | 481 | [
"Structural system",
"Structural engineering",
"Roofs"
] |
63,557,745 | https://en.wikipedia.org/wiki/NGC%203006 | NGC 3006 is an edge-on spiral galaxy in the constellation Ursa Major. It has an apparent magnitude of 15. It was discovered by the astronomer Bindon Stoney on January 25, 1851.
It is part of a small group of galaxies including NGC 2998, NGC 3002, NGC 3005, NGC 3008, and MCG+07-20-052.
References
Ursa Major
3006
Spiral galaxies
028235 | NGC 3006 | [
"Astronomy"
] | 92 | [
"Ursa Major",
"Constellations"
] |
63,557,748 | https://en.wikipedia.org/wiki/NGC%203302 | NGC 3302 is an unbarred lenticular galaxy in the constellation Antlia. It was discovered by the astronomer John Herschel on January 28, 1835.
References
Antlia
3302
Unbarred lenticular galaxies
031391 | NGC 3302 | [
"Astronomy"
] | 49 | [
"Antlia",
"Constellations"
] |
63,557,998 | https://en.wikipedia.org/wiki/NGC%202803 | NGC 2803, also known as PCG 26181, is an elliptical or lenticular galaxy in the zodiac constellation Cancer. It was discovered March 21, 1784, by William Herschel. It is interacting with NGC 2802.
One supernova has been observed in NGC 2803: SN 2017ilf (type Ia, mag. 18).
References
External links
Barred lenticular galaxies
2803
Cancer (constellation)
026181
Interacting galaxies | NGC 2803 | [
"Astronomy"
] | 93 | [
"Cancer (constellation)",
"Constellations"
] |
63,558,794 | https://en.wikipedia.org/wiki/Convex%20series | In mathematics, particularly in functional analysis and convex analysis, a is a series of the form where are all elements of a topological vector space , and all are non-negative real numbers that sum to (that is, such that ).
Types of Convex series
Suppose that is a subset of and is a convex series in
If all belong to then the convex series is called a with elements of .
If the set is a (von Neumann) bounded set then the series called a .
The convex series is said to be a if the sequence of partial sums converges in to some element of which is called the .
The convex series is called if is a Cauchy series, which by definition means that the sequence of partial sums is a Cauchy sequence.
Types of subsets
Convex series allow for the definition of special types of subsets that are well-behaved and useful with very good stability properties.
If is a subset of a topological vector space then is said to be a:
if any convergent convex series with elements of has its (each) sum in
In this definition, is not required to be Hausdorff, in which case the sum may not be unique. In any such case we require that every sum belong to
or a if there exists a Fréchet space such that is equal to the projection onto (via the canonical projection) of some cs-closed subset of Every cs-closed set is lower cs-closed and every lower cs-closed set is lower ideally convex and convex (the converses are not true in general).
if any convergent b-series with elements of has its sum in
or a if there exists a Fréchet space such that is equal to the projection onto (via the canonical projection) of some ideally convex subset of Every ideally convex set is lower ideally convex. Every lower ideally convex set is convex but the converse is in general not true.
if any Cauchy convex series with elements of is convergent and its sum is in
if any Cauchy b-convex series with elements of is convergent and its sum is in
The empty set is convex, ideally convex, bcs-complete, cs-complete, and cs-closed.
Conditions (Hx) and (Hwx)
If and are topological vector spaces, is a subset of and then is said to satisfy:
: Whenever is a with elements of such that is convergent in with sum and is Cauchy, then is convergent in and its sum is such that
: Whenever is a with elements of such that is convergent in with sum and is Cauchy, then is convergent in and its sum is such that
If X is locally convex then the statement "and is Cauchy" may be removed from the definition of condition (Hwx).
Multifunctions
The following notation and notions are used, where and are multifunctions and is a non-empty subset of a topological vector space
The of is the set
is (respectively, , , , , , , ) if the same is true of the graph of in
The multifunction is convex if and only if for all and all
The is the multifunction defined by For any subset
The is
The is For any subset
The is defined by for each
Relationships
Let be topological vector spaces, and The following implications hold:
complete cs-complete cs-closed lower cs-closed (lcs-closed) ideally convex.
lower cs-closed (lcs-closed) ideally convex lower ideally convex (li-convex) convex.
(Hx) (Hwx) convex.
The converse implications do not hold in general.
If is complete then,
is cs-complete (respectively, bcs-complete) if and only if is cs-closed (respectively, ideally convex).
satisfies (Hx) if and only if is cs-closed.
satisfies (Hwx) if and only if is ideally convex.
If is complete then,
satisfies (Hx) if and only if is cs-complete.
satisfies (Hwx) if and only if is bcs-complete.
If and then:
satisfies (H(x, y)) if and only if satisfies (Hx).
satisfies (Hw(x, y)) if and only if satisfies (Hwx).
If is locally convex and is bounded then,
If satisfies (Hx) then is cs-closed.
If satisfies (Hwx) then is ideally convex.
Preserved properties
Let be a linear subspace of Let and be multifunctions.
If is a cs-closed (resp. ideally convex) subset of then is also a cs-closed (resp. ideally convex) subset of
If is first countable then is cs-closed (resp. cs-complete) if and only if is closed (resp. complete); moreover, if is locally convex then is closed if and only if is ideally convex.
is cs-closed (resp. cs-complete, ideally convex, bcs-complete) in if and only if the same is true of both in and of in
The properties of being cs-closed, lower cs-closed, ideally convex, lower ideally convex, cs-complete, and bcs-complete are all preserved under isomorphisms of topological vector spaces.
The intersection of arbitrarily many cs-closed (resp. ideally convex) subsets of has the same property.
The Cartesian product of cs-closed (resp. ideally convex) subsets of arbitrarily many topological vector spaces has that same property (in the product space endowed with the product topology).
The intersection of countably many lower ideally convex (resp. lower cs-closed) subsets of has the same property.
The Cartesian product of lower ideally convex (resp. lower cs-closed) subsets of countably many topological vector spaces has that same property (in the product space endowed with the product topology).
Suppose is a Fréchet space and the and are subsets. If and are lower ideally convex (resp. lower cs-closed) then so is
Suppose is a Fréchet space and is a subset of If and are lower ideally convex (resp. lower cs-closed) then so is
Suppose is a Fréchet space and is a multifunction. If are all lower ideally convex (resp. lower cs-closed) then so are and
Properties
If be a non-empty convex subset of a topological vector space then,
If is closed or open then is cs-closed.
If is Hausdorff and finite dimensional then is cs-closed.
If is first countable and is ideally convex then
Let be a Fréchet space, be a topological vector spaces, and be the canonical projection. If is lower ideally convex (resp. lower cs-closed) then the same is true of
If is a barreled first countable space and if then:
If is lower ideally convex then where denotes the algebraic interior of in
If is ideally convex then
See also
Notes
References
Theorems in functional analysis | Convex series | [
"Mathematics"
] | 1,461 | [
"Theorems in mathematical analysis",
"Theorems in functional analysis"
] |
63,559,978 | https://en.wikipedia.org/wiki/NGC%20623 | NGC 623 is a large elliptical galaxy located in the Sculptor constellation at a distance of about 400 million light-years away from the Milky Way. It was discovered by British astronomer John Herschel on 30 November 1837.
See also
List of NGC objects (1–1000)
References
{{Sculptor (constellation)}
Elliptical galaxies
Sculptor (constellation)
0623
005898
18371130
Discoveries by John Herschel
353-023
-06-04-052 | NGC 623 | [
"Astronomy"
] | 96 | [
"Constellations",
"Sculptor (constellation)"
] |
63,560,008 | https://en.wikipedia.org/wiki/NGC%20624 | NGC 624 is a barred spiral galaxy in the constellation of Cetus, which is about 264 million light years from the Milky Way. It was discovered on November 28, 1785, by the German-British astronomer William Herschel.
See also
List of NGC objects (1–1000)
References
External links
Barred spiral galaxies
0624
Cetus
005932 | NGC 624 | [
"Astronomy"
] | 72 | [
"Cetus",
"Constellations"
] |
63,560,704 | https://en.wikipedia.org/wiki/Lippmann%20diagram | A Lippmann diagram is a graphical plot showing the solidus/solutus equilibrium states for a given binary solid solution (e.g., , barite/celestite) in equilibrium with an aqueous solution containing the two substituting ions: and (solid solution – aqueous solution system, or SS-AS). It was proposed in the 1970s by F. Lippmann to determine excess Gibbs functions. This diagram summarizes the thermodynamic basis of solid-solution aqueous-solution systems (SS-AS) equilibria and helps to predict the nucleation kinetics for solid solutions crystallizing from an aqueous solution.
In the diagram, the abscissa (horizontal axis) represents two variables with different scales to represent both the solid phase mole fraction and the aqueous activity fraction. The ordinate (vertical axis) represents the solid phase.
There are two variants of Lippmann diagrams:
Ion-activity Lippmann diagram
Total-scale Lippmann diagram
References
Solutions
Phase transitions
Diagrams | Lippmann diagram | [
"Physics",
"Chemistry"
] | 220 | [
"Physical phenomena",
"Phase transitions",
"Materials stubs",
"Phases of matter",
"Critical phenomena",
"Homogeneous chemical mixtures",
"Materials",
"Solutions",
"Statistical mechanics",
"Matter"
] |
63,561,238 | https://en.wikipedia.org/wiki/Piet%20Hartman | Piet Hartman (11 April 1922 – 26 March 2021) was a Dutch crystallographer, who worked as professor at Leiden University and Utrecht University between 1973 and 1987.
Career
Hartman was born in Veendam on 11 April 1922. He studied physical chemistry at the University of Groningen. Hartman subsequently obtained his title of doctor under professor P. Terpstra at the same university on 18 December 1953, with a dissertation titled: "Relations between structure and morphology of crystals". He became a lector of crystallography at Leiden University in 1959. In 1973 he was named full professor and he continued to work at Leiden University until 1980. In 1978 he was named professor of crystallography at Utrecht University, where he would work until his retirement in 1987.
Hartman was elected a member of the Royal Netherlands Academy of Arts and Sciences in 1982. He died on 26 March 2021, shortly before his 99th birthday.
References
1922 births
2021 deaths
Crystallographers
20th-century Dutch scientists
Academic staff of Leiden University
Members of the Royal Netherlands Academy of Arts and Sciences
People from Veendam
University of Groningen alumni
Academic staff of Utrecht University | Piet Hartman | [
"Chemistry",
"Materials_science"
] | 229 | [
"Crystallographers",
"Crystallography"
] |
63,562,105 | https://en.wikipedia.org/wiki/Surjection%20of%20Fr%C3%A9chet%20spaces | The theorem on the surjection of Fréchet spaces is an important theorem, due to Stefan Banach, that characterizes when a continuous linear operator between Fréchet spaces is surjective.
The importance of this theorem is related to the open mapping theorem, which states that a continuous linear surjection between Fréchet spaces is an open map. Often in practice, one knows that they have a continuous linear map between Fréchet spaces and wishes to show that it is surjective in order to use the open mapping theorem to deduce that it is also an open mapping. This theorem may help reach that goal.
Preliminaries, definitions, and notation
Let be a continuous linear map between topological vector spaces.
The continuous dual space of is denoted by
The transpose of is the map defined by If is surjective then will be injective, but the converse is not true in general.
The weak topology on (resp. ) is denoted by (resp. ). The set endowed with this topology is denoted by The topology is the weakest topology on making all linear functionals in continuous.
If then the polar of in is denoted by
If is a seminorm on , then will denoted the vector space endowed with the weakest TVS topology making continuous. A neighborhood basis of at the origin consists of the sets as ranges over the positive reals. If is not a norm then is not Hausdorff and is a linear subspace of .
If is continuous then the identity map is continuous so we may identify the continuous dual space of as a subset of via the transpose of the identity map which is injective.
Surjection of Fréchet spaces
Extensions of the theorem
Lemmas
The following lemmas are used to prove the theorems on the surjectivity of Fréchet spaces. They are useful even on their own.
Applications
Borel's theorem on power series expansions
Linear partial differential operators
being means that for every relatively compact open subset of , the following condition holds:
to every there is some such that in .
being means that for every compact subset and every integer there is a compact subset of such that for every distribution with compact support in , the following condition holds:
if is of order and if then
See also
References
Bibliography
Theorems in functional analysis | Surjection of Fréchet spaces | [
"Mathematics"
] | 473 | [
"Theorems in mathematical analysis",
"Theorems in functional analysis"
] |
63,562,828 | https://en.wikipedia.org/wiki/French-Azerbaijani%20University | The French-Azerbaijani University (, , UFAZ) was created in 2016 on the initiative of Azerbaijani President Ilham Aliyev and French President François Hollande as a joint project led by the University of Strasbourg and the Azerbaijan State Oil and Industry University (ASOIU).
History
On May 12, 2014, during the visit of the French President François Hollande to Azerbaijan, the Ministers of Education of France and Azerbaijan signed a Letter of intent focusing on cooperation between universities in order to strengthen educational ties between France and Azerbaijan.
Another Letter of intent was also signed by the Education Ministers of both countries on April 25, 2015 during the second official visit of François Hollande to Azerbaijan. On May 15 of the same year, the proposal for cooperation was approved by the President of the Republic of Azerbaijan by decree No. 1242, and on June 9, 2016, Ilham Aliyev signed an order about the implementation of the French-Azerbaijani University (UFAZ) project.
On September 15, 2016, the UFAZ inauguration ceremony was attended by the Minister of Education of Azerbaijan Mikayil Jabbarov and the French Ambassador to Azerbaijan Aurélia Bouchez. The first academic year of the UFAZ was housed in the main building of the Azerbaijan State Oil and Industry University (ASOIU).
On January 11, 2017, the UFAZ was visited by the French Secretary of State for Development and Francophonie Jean-Marie Le Guen, hosted by the Minister of Education of Azerbaijan, Mikayil Jabbarov, as well as the Presidents of the Universities of Strasbourg and Rennes 1.
The new premises of the UFAZ, located in a historical building at Nizami Street 183 and entirely renovated by the Ministry of Education of the Republic of Azerbaijan, were officially inaugurated on September 15, 2017. The ceremony was attended amongst others by the Minister of Education of the Republic of Azerbaijan, Mikail Jabbarov, the Rector of the Azerbaijan State Oil and Industry University Mustafa Babanli, the State Secretary under the Minister for Europe and Foreign Affairs of the French Republic, Jean-Baptiste Lemoyne, the Director General of Research and Innovation Department under the Ministry of Higher Education and Research of the French Republic Alain Beretz, the French Ambassador to Azerbaijan Aurélia Bouchez, the Vice-President of the University of Strasbourg Irène Jacoberger, and the President of the Foundation for Research in Chemistry of Strasbourg University, Bernard Meunier.
Education
To be admitted to UFAZ, applicants at the Bachelor level must pass the national centralized entrance exam conducted by the State Examination Center of the Republic of Azerbaijan. Those who score at least 500 out of 700 (from the group 1) are allowed to register to the UFAZ-held entrance exam, organized annually in July in Baku, by the University of Strasbourg.
Teaching at UFAZ is conducted in the English language, and the academic content followed is one of the University of Strasbourg, and the University of Rennes 1 for the oil and gas engineering bachelor program.
To harmonize the 3-year undergraduate course in France with the 4-year bachelor program in Azerbaijan, the first year at UFAZ is a foundation year. The teaching staff consists of both French and Azerbaijani professors. Upon graduation, UFAZ graduates receive Azerbaijani (ASOIU) and French (University of Strasbourg or University of Rennes 1) national diplomas.
At present, the UFAZ counts 4 specialties at the Bachelor level: chemical engineering, geophysical engineering, computer science, and oil and gas engineering.
Most UFAZ students, more than 80%, are scholarship holders who receive free education based on Azerbaijani government's financial support.
UFAZ will open new master's programs for the 2020/2021 academic year in the following areas: chemical engineering / physical chemistry, geosciences and applied computer sciences (big data and artificial intelligence).
References
University of Strasbourg
Universities in Baku
Azerbaijan State Oil and Industry University
Science and technology in Azerbaijan
Petroleum engineering schools
Universities and colleges established in 2016
2016 establishments in Azerbaijan
Azerbaijan–France relations | French-Azerbaijani University | [
"Engineering"
] | 831 | [
"Petroleum engineering",
"Petroleum engineering schools",
"Engineering universities and colleges"
] |
63,565,815 | https://en.wikipedia.org/wiki/Natalie%20Roe | Natalie Ann Roe is an experimental particle physicist and observational cosmologist, and the Associate Laboratory Director for the Physical Sciences Area at Lawrence Berkeley National Laboratory (LBNL) since 2020. Previously, she was the Physics Division Director for eight years. She has been awarded as the Fellow of American Physical Society (APS) and American Association for the Advancement of Science (AAAS) for her exceptional scientific career and contributions.
Education
Roe earned her undergraduate degree in physics from Harvard University in 1981, and her doctoral degree from Stanford University in 1989. She joined the Lawrence Berkeley National Laboratory as a postdoc in 1989, where she is currently the Associate Laboratory Director for the Physical Sciences Area.
Research career and collaborations
Roe particle physics research career has included the analysis of subatomic particle properties in accelerator-based experiments at SLAC and Fermi National Accelerator laboratories, and her cosmology research has involved surveys using telescopes based in Arizona, New Mexico, and Chile to study the mystery of dark energy including the Baryon Oscillation Spectroscopic Survey (BOSS), the Dark Energy Survey (DES) and the Dark Energy Spectroscopic Instrument (DESI).
She started her career in high energy physics with Professor Carlo Rubbia during her undergrad, which leads her to get a job at CERN for a year on the UA1 experiment. This experience at CERN plays a big impact on her ultimate career path in particle physics. During her PhD, she searched for Anomalous Single Photon at SLAC.
She started as a postdoc at Lawrence Berkeley National Laboratory in 1989 on the D0 experiment at Fermilab. She has a strong interest in instrumentation and has built the electromagnetic calorimeter on the D0 and analyised the production and decay of W and Z bosons at the Fermilab Tevatron, led the design and construction of the Silicon Vertex Tracker for the BaBar experiment at SLAC from 1993 to 2005, and was the Instrument Scientist for the BOSS experiment designed to study the mystery of dark energy. As group leader for the LBNL MicroSystems Laboratory for almost 10 years, she was responsible for the fabrication of the science CCDs for both DES and BOSS.
She has served on many community panels including High Energy Physics Advisory Panel (HEPAP), the National Science Foundation Physics Division Committee of Visitors, the FNAL Physics Advisory Committee (PAC), and the Neutrino Science Advisory Group, and she is a past Chair of the American Physical Society (APS) Division of Particles and Fields. She has also been a member of the International Committee on Future Accelerators (ICFA) from 2007 to 2009 and the DESY Scientific Council, and served on the CERN Scientific Policy Committee and several other national and international councils.
Natalie is also a founding member of the Berkeley Lab Women Scientists and Engineers Council and is co-leading a laboratory-wide initiative to improve diversity and inclusion at the Lab.
Honors and awards
Roe has been awarded as American Physical Society Fellow in 2001 for her leadership in the design and construction of the BaBar silicon vertex detector, and her studies of BB mixing, oscillations, and CP violation in B meson decays. In honor of her invaluable contributions to science and technology, she has been awarded as the Fellow of the American Association for the Advancement of Science in 2020.
References
External links
Berkeley Lab Women Scientists and Engineers Council
CERN Scientific Policy Committee
DESY Scientific Council
FNAL Physics Advisory Committee
International Committee on Future Accelerators
Stanford University alumni
Harvard College alumni
American cosmologists
Lawrence Berkeley National Laboratory people
Living people
Year of birth missing (living people)
Fellows of the American Physical Society
Particle physicists
20th-century American women scientists
Fellows of the American Association for the Advancement of Science
People associated with CERN
21st-century American women scientists | Natalie Roe | [
"Physics"
] | 770 | [
"Particle physicists",
"Particle physics"
] |
75,048,791 | https://en.wikipedia.org/wiki/Tremella%20samoensis | Tremella samoensis is a species of fungus in the family Tremellaceae. It produces red to orange-yellow, lobed to firmly foliaceous, gelatinous basidiocarps (fruit bodies) and is parasitic on other fungi on dead branches of broad-leaved trees. It was originally described from Samoa and the Philippines, but is widely distributed in the region.
Taxonomy
Tremella samoensis was first published in 1919 by American mycologist Curtis Gates Lloyd, based on a collection he made in Samoa together with material he received from the Philippines. Reviewing the species, Robert Bandoni considered it synonymous with the earlier Naematelia cinnabarina Mont., described from Tahiti in 1848. The combination in Tremella, as T. cinnabarina (Mont.) Pat., is however illegitimate since the name had already been used for a different species.
Description
Fruit bodies are firm, gelatinous, partly bright red, partly orange to yellow, up to 5 cm (2 in) across, and lobed to frondose, the lobes sometimes horn-like. Microscopically, the basidia are tremelloid (ellipsoid, with oblique to vertical septa), 4-celled, 12 to 18 by 8 to 12 μm. The basidiospores are ellipsoid, smooth, 6 to 8 by 4 to 6 μm.
Similar species
Tremella flammea, described from Japan by Yosio Kobayasi, is similarly coloured (scarlet to orange) but is said to be effused-lobate and have slightly smaller spores (5 to 5.5 by 4 to 5 μm). It is not clear if it is a distinct species. Kobayasi later made a collection in New Britain which he identified as T. cinnabarina and considered synonymous with Tremella dahliana, which German mycologist Paul Hennings had originally described from the same location.
Other Tremella species with scarlet to orange colours include Tremella dysenterica, originally described from Brazil, Tremella rubromaculata, originally described from Guatemala, and Tremella erythrina, originally described from China.
Habitat and distribution
Tremella samoensis is a parasite on lignicolous fungi, but its host species is unknown, though the original collection is associated with pyrenomycetes. It is found on dead, attached or fallen branches of broad-leaved trees.
The species was described from Samoa and has been reported from the Philippines, Tahiti, New Britain (as T. cinnabarina), China, Japan, and the Russian Far East.
References
samoensis
Fungi described in 1919
Taxa named by Curtis Gates Lloyd
Fungi of Oceania
Fungus species | Tremella samoensis | [
"Biology"
] | 577 | [
"Fungi",
"Fungus species"
] |
75,049,006 | https://en.wikipedia.org/wiki/Christopher%20B.%20Murray | Christopher Bruce Murray is the Richard Perry University Professor of Chemistry and Materials Science and Engineering at the University of Pennsylvania. He is a member of the National Academy of Engineering and a Fellow of the Materials Research Society. He was a Clarivate Citation Laureate in 2020. He is known for his contributions to quantum dots and other nanoscale materials.
Early life and education
Murray studied chemistry at St. Mary's University in Halifax, Nova Scotia, Canada from 1985, graduating with a Bachelor's Degree with Honors in Chemistry in 1988. He spent a year as a Rotary International Fellow at the University of Auckland in 1989. From 1990 he studied at the Massachusetts Institute of Technology (MIT), where he received his doctorate in chemistry in 1995.
Career
From 1995 Murray worked at the Thomas J. Watson Research Center at IBM. From 2000 to 2006 he headed their Nanoscale Materials and Devices Department. In 2006 the University of Pennsylvania announced his appointment as the Richard Perry University Professor, with appointments in Chemistry and Materials Science, in the schools of Arts and Sciences, and Engineering and Applied Science.
Research
Murray, David Norris and Manoj Nirmal were the first graduate students to work with Moungi Bawendi at MIT. As part of his thesis work, Murray helped to develop synthetic methods for making quantum dots, including identifying a longer chain version of trioctylphosphine oxide as being cheaper and having additional benefits when used in synthesis. In 1993, Murray, Norris and Bawendi published a breakthrough paper describing the hot injection synthesis method for making quantum dots. Both Murray's and Bawendi's contributions to the synthesis and characterization of semiconductor quantum dots were recognized by the American Chemical Society with its 1997 Nobel Laureate Signature Award.
Their method was both adaptable and reproducible, making it possible to consistently synthesise monodisperse nanoparticles and develop large-scale applications using quantum dots. Bawendi received the 2023 Nobel Prize in Chemistry for the development of this method.
Much of Murray's has work focused on the synthesis and characterization of nanoscale materials, including nanoscale magnets, semiconductor nanocrystals, and nanocrystal superlattices. Murray was recognized at IBM as a Master Inventor and patent evaluator. He holds at least 26 nanascale patents.
Murray is concerned with the synthesis and self-assembly properties of nanocrystals and the potential to create new mesoscopic materials with interesting properties and potential applications in energy, environmental sustainability, health, and information processing.
Murray is the Founding Chair of the World Economic Forum’s Global Councils on Nanotechnology (2008-2009) and Global Council on Emerging Technologies (2009-2010).
Awards and honors
1997 Nobel Laureate Signature Award of the American Chemical Society (with Moungi Bawendi)
2000, one of the most influential innovators younger than 35, Technology Review
2011, honorary doctorate, Utrecht University
2012 Fellow, Materials Research Society, for "innovations in the synthesis of nanomaterials with precisely controlled dimensions by chemical approaches; outstanding contributions in nanoparticle self-assembly; and pioneering research in the design of nanoparticle-based devices."
2019, Member, National Academy of Engineering for the "invention and development of solvothermal synthesis of monodisperse nanocrystal quantum dots for displays, photovoltaics and memory."
2020, Clarivate Citation Laureate with Moungi G. Bawendi and Taeghwan Hyeon "For synthesis of nanocrystals with precise attributes for a wide range of applications in physical, biological, and medical systems."
Selected publications
References
21st-century American chemists
American chemists
Living people
Massachusetts Institute of Technology School of Science alumni
Physical chemists
Nanotechnologists
Scientists at Bell Labs
University of Pennsylvania faculty
Members of the United States National Academy of Engineering
Year of birth missing (living people) | Christopher B. Murray | [
"Materials_science"
] | 794 | [
"Nanotechnology",
"Nanotechnologists"
] |
75,049,414 | https://en.wikipedia.org/wiki/Tremella%20olens | Tremella olens is a species of fungus in the family Tremellaceae. It produces soft, whitish, lobed to frondose, gelatinous basidiocarps (fruit bodies) and is parasitic on other fungi on dead branches of broad-leaved trees. It was originally described from Tasmania.
Taxonomy
Tremella olens was first published in 1860 by British mycologist Miles Joseph Berkeley based on a collection made in Tasmania.
Description
Fruit bodies are soft, gelatinous, whitish, and lobed. Microscopically, the basidia are tremelloid (ellipsoid, with oblique to vertical septa), 4-celled. The basidiospores are ellipsoid, smooth, 7.5 to 8.5 by 5.5 to 6.5 μm.
Similar species
Tremella olens belongs to a complex of similar species that have been differentiated by DNA sequencing and minor microscopic features. Tremella fibulifera and T. subfibulifera were both originally described from Brazil; Tremella neofibulifera and T. lloydiae-candidae were originally described from Japan; Tremella australe, T. cheejenii, T. guangxiensis, and T. latispora were originally described from China.
Tremella fuciformis is a white species also recorded from Australia, but fruit bodies have thin, erect fronds, often crisped at the edges.
Habitat and distribution
Tremella olens is a parasite on lignicolous fungi, but its host species is unknown. It is found on dead, attached or fallen branches of broad-leaved trees.
The species was originally described from Tasmania and has also been reported from Christmas Island. Reports from Venezuela and Jamaica refer to the South American species T. fibulifera or T. subfibulifera. Reports from Cameroon and Sabah belong to the species complex, but which species is uncertain.
References
olens
Fungi described in 1860
Fungi of Australia
Taxa named by Miles Joseph Berkeley
Fungus species
Parasitic fungi | Tremella olens | [
"Biology"
] | 431 | [
"Fungi",
"Fungus species"
] |
75,049,975 | https://en.wikipedia.org/wiki/Compound%202f%20%28SARM%29 | Compound 2f (SARM) is a drug which acts as a selective androgen receptor modulator (SARM), originally developed by Takeda Pharmaceutical for the treatment of prostate cancer. It is a potent but tissue specific androgen agonist with an EC50 of 4.7nM, producing anabolic effects on muscles and in the central nervous system but with little effect on the prostate gland, and inducing sexual behaviour in animal studies.
See also
LY305
References
Selective androgen receptor modulators
Anilines
Nitriles | Compound 2f (SARM) | [
"Chemistry"
] | 111 | [
"Nitriles",
"Functional groups"
] |
75,050,943 | https://en.wikipedia.org/wiki/Serum%20vitamin%20B12 | Serum vitamin B12 is a medical laboratory test that measure vitamin B12 only in the blood binding to both transcobalamins. Most of the time, 80–94% of vitamin B12 in the blood binds to haptocorrin, while only 6–20% is binds to transcobalamin ll. Only transcobalamin ll is "active" and can be used by the body. Normal total body vitamin B12 is between 2 and 5 mg with 50% of that stored in the liver. Total serum vitamin B12 may not be a reliable biomarker for reflecting what the body stores inside cells. Vitamin B12 levels can be falsely high or low and data for sensitivity and specificity vary widely. There is no gold standard human assay to confirm a vitamin B12 deficiency.
Healthcare providers use this test when a vitamin B12 deficiency is suspected, which can cause anemia and irreversible nerve damage. The cutoff between normal vitamin B12 levels and deficiency varies by country and region. A diagnosis of vitamin B12 deficiency is determined by blood levels lower than 200 or 250 picograms per ml (148 or 185 picomoles per liter). Some people can have symptoms with their normal levels of the vitamin, or may have low levels despite having no symptoms. Other tests may be done to ensure individuals status. Measuring vitamin B12 values in individuals during or after treatment, in order to measure the effectiveness of treatment, is useless.
Normal range
A blood test shows vitamin B12 levels in the blood. Vitamin B12 deficiency can be determined, but not always. This means it measures forms of vitamin B12 that are "active" and can be used by the body, as well as the "inactive" forms, which cannot. However, also normal or supraphysiological vitamin B12 levels should be carefully assessed in the context of the individual state of health. Elevated or normal serum vitamin B12 levels may also be associated with a functional vitamin deficiency. Functional deficiency has been described despite high B12 concentrations and is due to a failure of cellular uptake, intracellular processing, trafficking, or utilization. However, low vitamin B12 levels may occur other than the true deficiency for various reasons and circumstances. High or supraphysiological serum levels are usually not of concern, although without supplementation they have been associated with many pathological conditions.
Reference range for vitamin B12:
200 to 1000 picograms per ml (148 to 748 picomoles per liter)
Laboratories often use different units and "normal" may vary by population and the lab techniques used. Some researchers have suggested that current standards for vitamin B12 levels are too low.
References
Blood tests | Serum vitamin B12 | [
"Chemistry"
] | 552 | [
"Blood tests",
"Chemical pathology"
] |
75,051,375 | https://en.wikipedia.org/wiki/274%20%28number%29 | 274 (two hundred [and] seventy-four) is the natural number following 273 and preceding 275.
In mathematics
274 is an even composite number.
274's sum of its proper divisors is 140.
The number 274 is the 13th tribonacci number. This is defined by the equations P(0)=P(1)=0 P(2)=1 and P(n)=P(n-1)+P(n-2)+P(n-3).
274 is the sum of 5 perfect cubes. It is the sum of 2³+2³+2³+5³+5³.
274 is a Stirling number of the first kind which counts the number of permutations and their number of cycles.
References
Integers | 274 (number) | [
"Mathematics"
] | 162 | [
"Elementary mathematics",
"Integers",
"Mathematical objects",
"Numbers"
] |
75,051,930 | https://en.wikipedia.org/wiki/ZGN-1061 | ZGN-1061 is an experimental drug that was developed by Zafgen for treatment of obesity and type 2 diabetes. It has a similar mechanism of action as the discontinued drug Beloranib but was considered safer; however, its development was also halted because of safety concerns.
References
METAP2 inhibitors
Epoxides
Azetidines
4-Morpholinyl compounds
Esters
Methoxy compounds
Spiro compounds | ZGN-1061 | [
"Chemistry"
] | 86 | [
"Organic compounds",
"Esters",
"Functional groups",
"Spiro compounds"
] |
75,052,034 | https://en.wikipedia.org/wiki/TNP-470 | TNP-470 is an methionine aminopeptidase 2 inhibitor. Although it was one of the first angiogenesis inhibitor tested in clinical trials, its potential was hampered by neurotoxic effects and lack of effectiveness.
References
METAP2 inhibitors
Epoxides
Spiro compounds
Carbamates
Methoxy compounds | TNP-470 | [
"Chemistry"
] | 70 | [
"Organic compounds",
"Spiro compounds"
] |
75,052,755 | https://en.wikipedia.org/wiki/Land%20Information%20and%20Management%20System | The Land Information and Management System (LIMS) is a system introduced in Pakistan to improve contemporary agricultural practices. The former Prime Minister, Shehbaz Sharif and Chief of Army Staff (COAS) General Asim Munir, inaugurated the system. Headed by Maj Gen Muhammad Ayub Ahsan Bhatti, it’s goal is to boost the agriculture sector, which accounts for nearly 25% of the country's GDP.
LIMS is based on a geographic information system (GIS), and aims to streamline the digitization of farming processes. It gives farmers online access to data on climate shifts, satellite-based crop monitoring, water usage, fertilizer application, and targeted spray zones. Its developers believe that LIMS will create jobs for the youth and rejuvenate unused and underutilized land.
Background
LIMS offers real-time updates to farmers regarding soil conditions, crops, weather, water availability, and pest monitoring using remote sensing and geospatial technologies. Additionally, the system is designed to reduce the reliance on intermediaries through an effective marketing framework.
LIMS has main goals centered around bolstering food security, advancing agricultural exports, and alleviating the financial burden caused by imports on the nation's treasury. It is designed to convert underutilized or low-yield land within the country, and reduce food insecurity, malnutrition, and the escalating costs associated with agricultural imports.
Collaborations
LIMS collaborates with several countries including Saudi Arabia, the United Arab Emirates, Qatar, Bahrain, and China for multiple agricultural ventures aimed at boosting Pakistan's exports. In 2023, Saudi Arabia made a $500 million investment to establish the facility.
References
External links
Agriculture in Pakistan
Information systems
2023 establishments in Pakistan | Land Information and Management System | [
"Technology"
] | 365 | [
"Information systems",
"Information technology"
] |
75,053,435 | https://en.wikipedia.org/wiki/OnePlus%20Open | The OnePlus Open is a foldable smartphone manufactured by OnePlus. The phone was co-developed with its parent company Oppo which markets the phone as the Oppo Find N3. The product was revealed on 19 October 2023.
History
In early October 2023, OnePlus' co-founder and CEO Pete Lau confirmed that the OnePlus Open was designed by both OnePlus and Oppo, and that it would be released under both brands with different names. It was rumoured that Oppo's name would be the Oppo Find N3.
Hardware
The OnePlus Open has a 6.31-inch front screen. When it is folded out, the screen is 7.82 inches. It is 11.7 millimetres thick when folded. It has 120hz AMOLED screens on both the front and inside. It has 16 GB of RAM and 512 GB of internal storage. It has a 4,805-mAh battery and the Qualcomm Snapdragon 8 Gen 2 chipset. The phone has no wireless charging. The phone comes in 2 finishes depending on color the Black model has a leatherette back while the Emerald Dusk model has a glass back. On the back it has a triple camera setup, in partnership with Hasselblad. The main camera is a 48MP SONY LYT-T808 “Pixel Stacked” Sensor, 1/1.43” sensor, 1.12 μm, ƒ/1.7, AF. The telephoto is a 64MP OV64B Sensor with 3X Optical Zoom, 6X in-sensor zoom, 1/2” sensor, 0.7 μm, ƒ/2.6, AF. The ultrawide camera is a 48MP Sony IMX581 with 114° FOV, 1/2” sensor, ƒ/2.2, AF.
Software Improvements
The OnePlus Open runs OxygenOS 13.2, which the company says it will support with four years of OS upgrades for the Open and five years of security updates. This iteration of OxygenOS comes with some thoughtful multitasking features to make use of the large inner screen. You can open two apps in a split view, as you’d expect, but you can also add a third app that sort of hovers on the side of the display so it’s partially visible and you can tab over to it quickly. App pairs and trios can be saved as home screen shortcuts, too.
There’s a taskbar that you can display and hide easily, and it includes recent apps as well as a folder of recent documents. There’s also support for floating windows, which you can position anywhere on the screen, resize to your taste, and minimize to a tab at the side of the screen so you can easily fetch them again.
By default, when you open an app on the inner display, it will expand to fill the whole screen. Opening a second app in split screen view doesn’t automatically resize the first app to display on half the screen, though. The first app kind of scoots over, and your view of it is cut off.
You can work around this in settings by dictating how each individual app should display on the main screen — in 16:9, 4:3, or full screen. Switching to 16:9 makes room for another app on the unoccupied portion of the screen without cutting off the first one.
Pricing
The Oneplus Open starts at $1600. At launch, trade-in discounts of $200 or more are available, including a $200 trade-in discount on any smartphone of any condition.
Issues
An early reviewer of the phone, Marques Brownlee, stated that while the phone was great in hardware, his display had dead pixels within barely a week of using the phone. OnePlus has not yet commented on this.
References
OnePlus mobile phones
Foldable smartphones
Mobile phones introduced in 2023
Mobile phones with multiple rear cameras
Mobile phones with 4K video recording | OnePlus Open | [
"Technology"
] | 833 | [
"Crossover devices",
"Foldable smartphones"
] |
75,053,741 | https://en.wikipedia.org/wiki/Yordanka%20Mincheva%20-%20Stefanova | Yordanka Hristova Mincheva - Stefanova (Bulgarian: Йорданка Христова Минчева - Стефанова) (29 August 1923 – 28 April 2007), Aka Jordanka Mincheva - Stefanova, Jordanka Minčeva - Stefanova, was a Bulgarian geologist, mineralogist and crystallographer. Her scientific interests were in sulphide mineralogy, crystal chemistry and genesis of minerals - sulphides, carbonates, arsenates, silicates etc.
Selected publications
References
External links
1923 births
2007 deaths
Mineralogists
Crystallographers
Bulgarian geologists
Sofia University alumni
20th-century geologists
20th-century Bulgarian scientists
People from Stara Zagora | Yordanka Mincheva - Stefanova | [
"Chemistry",
"Materials_science"
] | 161 | [
"Crystallographers",
"Crystallography"
] |
75,054,010 | https://en.wikipedia.org/wiki/Keel%20block | In marine terms, a keel block, is a concrete or dense wood cuboid that rests under a ship during a time of repair, construction, or in the event of a dock being drained. The block rests under the keel of a ship.
Purpose
The purpose of a keel block is to prevent the ship from sitting directly on the ground and to prevent damage or instability that sitting on the ground may cause.
References
Nautical terminology
Shipbuilding | Keel block | [
"Engineering"
] | 87 | [
"Shipbuilding",
"Marine engineering"
] |
75,054,207 | https://en.wikipedia.org/wiki/X%20Puppis | The Bayer designations X Puppis and x Puppis are distinct and refer to three different stars in the constellation Puppis:
X Puppis, a δ Cephei variable
X Puppis, (HR 2548, 38 G. Puppis) an F-type main-sequence star
x Puppis, (HR 2518, HD 49591, 31 G. Puppis), a B-type main-sequence star
See also
Xi Puppis
χ Puppis
Puppis, x
Puppis | X Puppis | [
"Astronomy"
] | 102 | [
"Puppis",
"Constellations"
] |
75,055,566 | https://en.wikipedia.org/wiki/HD%20196917 | HD 196917 (HR 7909; 17 G. Microscopii; NSV 25227) is a solitary star located in the southern constellation Microscopium. It is faintly visible to the naked eye as a red-hued point of light with an apparent magnitude of 5.74. Gaia DR3 parallax measurements imply a distance of 426 light-years and it is rapidly approaching the Solar System with a heliocentric radial velocity of . At its current distance, HD 196917's brightness is diminished by 0.13 magnitudes due to interstellar extinction and it has an absolute magnitude of +0.04.
HD 196917 has a stellar classification of either M1 III or M0 III, indicating that it is an evolved M-type giant. It is currently on the asymptotic giant branch, fusing hydrogen and helium shells around an inert carbon core. It has 1.27 times the mass of the Sun but it has expanded to 44.2 times the radius of the Sun. It radiates 620 times the luminosity of the Sun from its enlarged photosphere at an effective temperature of . HD 196917 is metal deficient with an iron abundance of [Fe/H] = −0.28 or 52.5% of the Sun's.
The variability of the star was first detected in 1997 by the Hipparcos mission. It found variations between 5.82 and 5.86 in the Hipparcos passband. Koen & Lyer (2002) observed visual variations from the star and found that HD 196917 varies by 0.009 magnitudes within 21.01 hours. As of 2004, its variability has not been confirmed.
References
M-type giants
Asymptotic-giant-branch stars
Suspected variables
Microscopium
Microscopii, 17
CD-32 16130
196917
102092
7909
00441396067 | HD 196917 | [
"Astronomy"
] | 398 | [
"Microscopium",
"Constellations"
] |
75,056,172 | https://en.wikipedia.org/wiki/Bettina%20Richmond | Martha Bettina Richmond (née Zoeller, January 30, 1958 – November 22, 2009) was a German-American mathematician, mathematics textbook author, professor at Western Kentucky University, and murder victim.
Life
Richmond was born in Dresden on January 30, 1958, earned a vordiplom (the German equivalent of a bachelor's degree) from the University of Würzburg, and completed her Ph.D. at Florida State University in 1985. Her doctoral dissertation, Freeness of Hopf algebras over grouplike subalgebras, was supervised by Warren Nichols, a student of Irving Kaplansky.
She became a professor at Western Kentucky University, teaching there for 23 years. Topics in her mathematical research included abstract algebra, transformation semigroups, ring theory, and Hopf algebra, including the proof of the Nichols–Zoeller freeness theorem in Hopf algebra. With her husband, Thomas Richmond, she was the author of a mathematics textbook, A Discrete Transition to Advanced Mathematics. She also published works in recreational mathematics.
Murder
Richmond was stabbed to death on November 22, 2009, in the parking lot of a racquetball facility in downtown Bowling Green, Kentucky. According to the FBI, her murder was likely an opportunistic crime motivated by armed robbery. At the time of her death, she had been on leave from her faculty position to assist her father in Germany. The murder is still unsolved.
Selected publications
References
1958 births
2009 deaths
2009 murders in the United States
German emigrants to the United States
Scientists from Dresden
American mathematicians
American women mathematicians
Algebraists
University of Würzburg alumni
Florida State University alumni
Western Kentucky University faculty
People murdered in Kentucky
Female murder victims
Unsolved murders in the United States
Deaths by stabbing in the United States | Bettina Richmond | [
"Mathematics"
] | 356 | [
"Algebra",
"Algebraists"
] |
75,057,181 | https://en.wikipedia.org/wiki/289%20%28number%29 | 289 is the natural number following 288 and preceding 290.
In mathematics
289 is an odd composite number with only one prime factor.
289 is the 9th Friedman number. Friedman numbers are numbers that can be written by using its own digits the exact number of times they show up in the number. This one can be expressed as (8+9)².
289 is a perfect square being equal to 17². It is also the 7th number to only have 3 factors because it is a square of a prime number.
289 is the sum of perfect cubes. It is the sum of 1³+2³+4³+6³.
289 is equivalent to the sum of the first 5 whole numbers to their respective powers. It is equal to 0⁰+1¹+2²+3³+4⁴.
References
External links
Integers | 289 (number) | [
"Mathematics"
] | 170 | [
"Elementary mathematics",
"Integers",
"Mathematical objects",
"Numbers"
] |
75,058,075 | https://en.wikipedia.org/wiki/B%20Hydrae | The Bayer designation b Hydrae refers to three different stars in the constellation Hydra:
b1 Hydrae, (3 Crateris, HD 93397), an F-type main-sequence star
b2 Hydrae, (5 Crateris, 249 G. Hydrae, HD 94046), an A-type main-sequence star
b3 Hydrae, (6 Crateris, 257 G. Hydrae, HD 94388), a F-type main-sequence star
Hydrae, b
Hydra (constellation) | B Hydrae | [
"Astronomy"
] | 109 | [
"Hydra (constellation)",
"Constellations"
] |
75,058,414 | https://en.wikipedia.org/wiki/293%20%28number%29 | 293 is the natural number following 292 and preceding 294.
In mathematics
293 is:
a prime number,
a Pythagorean prime,
a Sophie Germain prime
a Chen prime
strictly trivially polygonal (number n that is polygonal in only 2 ways: 2-gonal and n-gonal)
equivalent to the sum of the first three tetradic primes. Tetradic numbers are numbers that are the same if written backwards, flipped upside-down, or mirrored upside-down and tetradic primes are tetradic numbers that are also prime. It is the sum of 11 + 101 + 181.
the sum of perfect cubes 2³+2³+3³+5³+5³
References
Integers | 293 (number) | [
"Mathematics"
] | 151 | [
"Elementary mathematics",
"Integers",
"Mathematical objects",
"Numbers"
] |
75,058,467 | https://en.wikipedia.org/wiki/Z%20Puppis | The Bayer designations Z Puppis and z Puppis are distinct and refer to two different stars in the constellation Puppis:
Z Puppis, a variable star
z Puppis, (OW Puppis, HD 60606, 115 G. Puppis), a γ Cas variable
See also
Zeta Puppis
Puppis, z
Puppis | Z Puppis | [
"Astronomy"
] | 69 | [
"Puppis",
"Constellations"
] |
75,058,584 | https://en.wikipedia.org/wiki/N%20Puppis | The Bayer designations N Puppis and n Puppis are distinct and refer to three different stars in the constellation Puppis:
N Puppis, (HD 65551, 228 G. Puppis), a B-type main-sequence star
n Puppis (a binary star system, refers to two stars)
n Puppis A, (HR 2909, HD 60584, 111 G. Puppis), an F-type main-sequence star
n Puppis B, (HR 2910, HD 60585, 112 G. Puppis), an unknown-type star
See also
Nu Puppis
Puppis, n
Puppis | N Puppis | [
"Astronomy"
] | 133 | [
"Puppis",
"Constellations"
] |
75,059,246 | https://en.wikipedia.org/wiki/Energy%20expenditure | Energy expenditure, often estimated as the total daily energy expenditure (TDEE), is the amount of energy burned by the human body.
Causes of energy expenditure
Resting metabolic rate
Resting metabolic rate generally composes 60 to 75 percent of TDEE. Because adipose tissue does not use much energy to maintain, fat free mass is a better predictor of metabolic rate. A taller person will typically have less fat mass than a shorter person at the same weight and therefore burn more energy. Men also carry more skeletal muscle tissue on average than women, and other sex differences in organ size account for sex differences in metabolic rate. Obese individuals burn more energy than lean individuals due to increase in the amount of calories needed to maintain adipose tissue and other organs that grow in size in response to obesity. At rest, the largest fractions of energy are burned by the skeletal muscles, brain, and liver; around 20 percent each. Increasing skeletal muscle tissue can increase metabolic rate.
Activity
Energy burned during physical activity includes the exercise activity thermogenesis (EAT) and non-exercise activity thermogenesis (NEAT).
Thermic effect of food
Thermic effect of food is the amount of energy burned digesting food, around 10 percent of TDEE. Proteins are the component of food requiring the most energy to digest.
Changing energy expenditure
Weight change
Losing or gaining weight affects the energy expenditure. Reduced energy expenditure after weight loss can be a major challenge for people seeking to avoid weight regain after weight loss. It is controversial whether losing weight causes a decrease in energy expenditure greater than expected by the loss of adipose tissue and fat-free mass during weight loss. This excess reduction is termed adaptive thermogenesis and it is estimated that it might compose 50 to 100 kcal/day in people actively losing weight. Some studies have reported that it disappears after a short period of weight stability, while others report longer-lasting effects.
Changing the activity level
Increasing exercise is recommended as a way to increase energy expenditure in individuals seeking to lose weight.
Drugs
Some drugs used for weight loss work by increasing energy expenditure. Two of the earliest weight loss drugs, 2,4-dinitrophenol and thyroid hormone, increase energy expenditure, but both were withdrawn from use due to risks. Adrenergic agonists, especially those that work on the beta-2 adrenergic receptor, increase energy expenditure. Although some such as clenbuterol are used without medical approval for weight loss, none have achieved approval for this indication due to cardiac risks.
Other drugs such as atypical antipsychotics are believed to reduce energy expenditure.
Effects
Energy expenditure is a leading factor in regulating appetite and energy intake in humans.
Measurement
Formulas have been devised to estimate energy expenditure in humans, but they may not be accurate for people with certain illnesses or the elderly. Not all formula are accurate in overweight or obese individuals.
Wearable devices can help estimate energy expenditure from physical activity but their accuracy varies.
References
Human physiology
Metabolism | Energy expenditure | [
"Chemistry",
"Biology"
] | 608 | [
"Cellular processes",
"Biochemistry",
"Metabolism"
] |
75,059,247 | https://en.wikipedia.org/wiki/Thandi%20%28rhinoceros%29 | Thandi is a female Southern white rhinoceros living in Kariega Game Reserve in the Eastern Cape, South Africa. She is the first known rhinoceros to have survived being poached.
Background
Thandi grew up in Kariega Game Reserve with several other rhinoceroses. After the poaching incident, she was named Thandi, a isiXhosa word which translates to "courage".
Poaching incident
On 2 March 2012, Thandi and two other rhinoceroses were poached in Kariega Game Reserve. One died overnight, but Thandi and another rhinoceros were found by wildlife conservationists. With the help of the other conservationists, Dr. William Fowlds treated the rhinoceroses for their injuries. The other rhinoceros was named Themba and survived for another month before succumbing to his injuries, but the conservationists managed to save Thandi. It is suspected that the poachers tranquilized the rhinoceroses and used a machete to dehorn them.
Breeding
Nearly three years after being poached, Thandi gave birth to a calf on 13 January 2015.
References
Individual rhinoceroses
Wildlife conservation
Individual animals in South Africa | Thandi (rhinoceros) | [
"Biology"
] | 248 | [
"Wildlife conservation",
"Biodiversity"
] |
75,059,706 | https://en.wikipedia.org/wiki/Fire%20sign%20%28address%29 | A fire sign is an address sign or similar placard placed in some rural areas where driveways connect to roads. They are usually bolted on to steel fence posts that are driven into the ground. Each town or county sets the standard as to how the address sign shall look, such as vertical or horizontal numbers and letters, dual or single sided, town/community name or road displayed.
Well placed visible signs are essential to help people find specific locations in a timely manner as well as emergency services such as police, fire department, or ambulance and also delivery workers such as United States Postal Service, UPS, FedEx, and more.
See also
Postal system
Parcel delivery
License plate
References
Human geography
Postal systems
Address (geography)
Identifiers | Fire sign (address) | [
"Technology",
"Environmental_science"
] | 149 | [
"Transport systems",
"Environmental social science",
"Human geography",
"Postal systems"
] |
75,060,288 | https://en.wikipedia.org/wiki/Analytic%20combinatorics | Analytic combinatorics uses techniques from complex analysis to solve problems in enumerative combinatorics, specifically to find asymptotic estimates for the coefficients of generating functions.
History
One of the earliest uses of analytic techniques for an enumeration problem came from Srinivasa Ramanujan and G. H. Hardy's work on integer partitions, starting in 1918, first using a Tauberian theorem and later the circle method.
Walter Hayman's 1956 paper "A Generalisation of Stirling's Formula" is considered one of the earliest examples of the saddle-point method.
In 1990, Philippe Flajolet and Andrew Odlyzko developed the theory of singularity analysis.
In 2009, Philippe Flajolet and Robert Sedgewick wrote the book Analytic Combinatorics, which presents analytic combinatorics with their viewpoint and notation.
Some of the earliest work on multivariate generating functions started in the 1970s using probabilistic methods.
Development of further multivariate techniques started in the early 2000s.
Techniques
Meromorphic functions
If is a meromorphic function and is its pole closest to the origin with order , then
as
Tauberian theorem
If
as
where and is a slowly varying function, then
as
See also the Hardy–Littlewood Tauberian theorem.
Circle Method
For generating functions with logarithms or roots, which have branch singularities.
Darboux's method
If we have a function where and has a radius of convergence greater than and a Taylor expansion near 1 of , then
See Szegő (1975) for a similar theorem dealing with multiple singularities.
Singularity analysis
If has a singularity at and
as
where then
as
Saddle-point method
For generating functions including entire functions which have no singularities.
Intuitively, the biggest contribution to the contour integral is around the saddle point and estimating near the saddle-point gives us an estimate for the whole contour.
If is an admissible function, then
as
where .
See also the method of steepest descent.
Notes
References
Further reading
External links
Analytic Combinatorics online course
An Introduction to the Analysis of Algorithms online course
Analytic Combinatorics in Several Variables projects
An Invitation to Analytic Combinatorics
See also
Symbolic method (combinatorics)
Analytic Combinatorics (book)
Enumerative combinatorics | Analytic combinatorics | [
"Mathematics"
] | 470 | [
"Enumerative combinatorics",
"Combinatorics"
] |
75,060,509 | https://en.wikipedia.org/wiki/IDN%20Times | IDN Times is a digital multi-platform media outlet that provides news and entertainment for Millennials and Gen Z in Indonesia. IDN Times is one of IDN’s business units under the Digital Media pillar, founded by Winston Utomo and William Utomo on June 8, 2014. Currently, senior journalist Uni Zulfiani Lubis serves as the Editor-in-Chief of IDN Times.
History
IDN Times was initially known as Indonesian Times, a blog featuring articles written by Winston Utomo while he was working at Google Singapore. As interest and readership grew, Indonesian Times evolved into IDN Times, a digital multi-platform media company focused on delivering relevant content for Indonesia’s younger generations.
Bureau
IDN Times has a representative bureau that has spread over 12 provinces in Indonesia:
Events
Indonesia Millennial and Gen Z Summit
The Indonesia Millennial and Gen-Z Summit (IMGS) is an annual event organized by IDN. This event aims to empower Indonesia’s younger generations through discussions and interdisciplinary collaborations. IMGS features inspirational figures, professionals, and leaders from various fields who share insights and drive positive change.
The event hosts dozens of discussion sessions in collaboration with eight prominent communities. Topics covered include politics, economics, technology, and pop culture.
Indonesia Writers Festival
The Indonesia Writers Festival is an independent writing festival organized by IDN Times. The event seeks to empower Indonesians through writing by inviting experts and literacy activists from various backgrounds.
Duniaku.com
Duniaku.com is a multi-platform digital media part of IDN Times which presents content about geek culture ranging from video games, anime, comics, films, technology and gadgets. Duniaku.com was officially launched on September 6, 2019 by the Minister of Communication and Informatics Rudiantara together with CEO of IDN Media Winston Utomo and IDN Times and Editor-in-Chief of Duniaku.com Uni Lubis.
Awards
2019 IDN won WAN-IFRA Asia Digital Media Awards 2019 as the Best Digital Project to Engage Younger and/or Millennial Audiences for IDN Times’ #MillennialsMemilih program
2020 IDN Times (IDN Times Community) won WAN-IFRA Asia Digital Media Awards 2019 in The Best in Audience Engagement category.
2021 IDN Times journalists won awards at the Subroto Award, Ministry of Energy and Mineral Resources (ESDM) on 28 September 2021.
2024 IDN Times won WAN-IFRA event at both the Asia and Global levels in Best Use of AI in Revenue Strategy.
#Interconnected22 by Pulitzer Center
One of the IDN Times journalists, Dhana Kencana, was the speaker at the #Interconnected22 conference held from June 9 to June 10, 2022, in Washington DC, United States of America. Dhana Kencana is also a grant recipient Pulitzer Center through the Rainforest Journalism Fund (RJF) program, a funding program for journalists that makes a number of coverage of the rainforest.
References
External links
Digital media
Indonesian news websites
Indonesian press
Mass media in Jakarta
Internet properties established in 2014
IDN (company) | IDN Times | [
"Technology"
] | 632 | [
"Multimedia",
"Digital media"
] |
75,061,101 | https://en.wikipedia.org/wiki/International%20Association%20for%20Soaps%2C%20Detergents%20and%20Maintenance%20Products | The International Association for Soaps, Detergents and Maintenance Products (AISE) is a trade association representing over 900 European producers of household and professional cleaning products. It was founded in 1995 as a merger of the International Association of the Soap and Detergent Industry and the International Federation of Associations of Cleaning Products Manufacturers, the former being founded in 1952.
See also
UK Cleaning Products Industry Association
American Cleaning Institute
References
Organisations based in Brussels
Trade associations based in Belgium
Cleaning products
1995 establishments in Belgium | International Association for Soaps, Detergents and Maintenance Products | [
"Chemistry"
] | 98 | [
"Cleaning products",
"Products of chemical industry"
] |
75,061,263 | https://en.wikipedia.org/wiki/Tetraiodoethylene | Tetraiodoethylene (TIE), or diiodoform, is the periodinated analogue of ethylene with the chemical formula . It is a decomposition product of carbon tetraiodide and diiodoacetylene. It is an odourless yellow crystalline solid that is soluble in benzene and chloroform, and insoluble in water. It has been used as an antiseptic and a component in pesticide and fungicide formulations.
Tetraiodoethylene reacts with ethylamine to give ethylamine di-tetraiodoethylene, EtNH2.(C2I4)2,
and ethylaminetetraiodoethylene. Tetraiodoethylene and iodine pentafluoride yield iodopentafluoroethane.
Tetraiodoethylene turns brown and emits a "characteristic" odour due to decomposition when exposed to light.
History
Tetraiodoethylene was discovered by Baeyer in 1885. It was proposed as an antiseptic under the name Diiodoform, in 1893 by M. L. Maquenne and Taine. It was an alternative to iodoform which has a strong and persistent odour that caused difficulties for physicians in private practices.
Synthesis
Tetraiodoethylene can be made by the iodination of calcium carbide:
Diiodoacetylene is a byproduct of the reaction which can later be iodinated to TIE.
The action of aqueous solution of potassium hydroxide and iodine on barium carbide in chloroform or benzene can also give TIE. Another synthesis involves mixing separate solutions of diiodoacetylene and iodine in carbon disulphide. Tetraiodoethylene would be left as a residue after carbon disulphide was evaporated.
See also
1,2-Diiodoethylene
Triiodoethylene
Tetrafluoroethylene
Tetrachloroethylene
Tetrabromoethylene
References
Iodoalkenes
Pesticides
Fungicides
Antiseptics | Tetraiodoethylene | [
"Biology",
"Environmental_science"
] | 462 | [
"Fungicides",
"Biocides",
"Toxicology",
"Pesticides"
] |
75,061,492 | https://en.wikipedia.org/wiki/Gasping%20syndrome | Gasping syndrome is a life-threatening condition characterized by multi-system failure, death and other symptoms resulting from benzyl alcohol poisoning.
Symptoms
The symptoms caused by benzyl alcohol exposure include respiratory failure, hypotension, renal failure, severe metabolic acidosis, hematologic abnormalities, convulsions, paralysis gradual neurologic deterioration, cardiovascular collapse, sudden onset of gasping respiration, skin changes and vasodilation.
See also
Benzyl alcohol
References
Poisons | Gasping syndrome | [
"Chemistry",
"Environmental_science"
] | 98 | [
"Pharmacology",
"Toxicology",
"Medicinal chemistry stubs",
"Poisons",
"Pharmacology stubs"
] |
75,061,811 | https://en.wikipedia.org/wiki/Monument%20to%20the%20Polish%20Endeavor | The Monument to the Polish Endeavor (Polish: Pomnik Czynu Polaków), also known as the Monument of the Three Eagles (Polish: Pomnik Trzech Orłów), and the Eagles' Nest (Polish: Gniazdo Orłów), is a monument in the city of Szczecin, Poland, located at the Bright Meadows Square, at the boundary with the Jan Kasprowicz Park. It was designed by Gustaw Zemła, and unveiled in 1979.
The monument consists of three bronze sculptures of eagles with spread wings, each placed on a steel column with a square base. The three birds are meant to symbolize three generations of Polish inhabitants of the city. That includes the Polish people who lived in the city prior to the end of the Second World War in 1945, people who moved to, and rebuilt the city after the end of the conflict, in place of mostly German population, who left or were deported, and the children of the new population, who further developed the city.
Name
The monument is officially known as the Monument to the Polish Endeavor (Polish: Pomnik Czynu Polaków). Its author, Gustaw Zemła, titled it Eagles' Nest (Polish: Gniazdo Orłów). The sculpture, which is the main element of the monument, is known as the Three Eagles (Polish: Trzy Orły), and as such, the monument is also sometimes colloquially known as the Monument of the Three Eagles (Polish: Pomnik Trzech Orłów).
History
On 6 September 1972, the Szczecin Voivodeship Committee of the Polish United Workers' Party decided to build a monument in Szczecin, Poland. It was proposed by Janusz Brych, the general secretary of the voivodeship committee. The monument was meant to be a sign of respect and gratitude for the inhabitants of the city of Szczecin, for their efforts in rebuilding and expanding the city since the end of the Second World War. The efforts of the monument construction were taken on by the Friends of Szczecin Society (Polish: Towarzystwo Przyjaciół Szczecina), which was led by Jan Stopyra, the mayor of Szczecin. The monument was originally meant to be unveiled for the 30th anniversary of the end of the Second World War, however, due to delays and prolonged discussions, it was ultimately decided to unveil it on the 35th anniversary instead. On 29 December 1976, was established the Organization of Monument Construction Committee, with Jan Stopyra as its leader. It was decided that the monument would be built at the Bright Meadows Square, at the boundary with the Jan Kasprowicz Park.
The monument was designed by Gustaw Zemła, in cooperation with Eugeniusz Kozak. The steel pedestal of the monument was designed by Jerzy Piskorz-Nałęcki, in cooperation with Jerzy Podesławski and Edward Pianko. The construction of the monument was overseen by Kazimierz Szulc. It was decided to name it the Monument to the Polish Endeavor (Polish: Pomnik Czynu Polaków), though Zemła titled it the Eagles' Nest (Polish: Gniazdo Orłów). The monument would consist of the bronze sculpture of three eagles, placed on the steel pedestal. The three birds were meant to symbolize three generations of Polish inhabitants of the city. That included the Polish people who lived in the city prior to the end of the Second World War in 1945, people who moved to, and rebuilt the city after the end of the conflict, in place of mostly German population, who left or were deported, and the children of the new population, who further developed the city.
The bronze sculptures of the moment were manufactured in Marcel Nowotka Mechanical Factories (now PZL-Wola) in Warsaw, and the metal steel pedestal of the monument, in the Szczecin Shipyard. The sculptures were transported from Warsaw with barges of the Żegluga Szczecińska (Szczecin Shipping), by the Vistula river to the sea port in Gdańsk, and from there to the port in Świnoujście via the Baltic Sea, and then to the port in Szczecin, via the Szczecin Lagoon and the Oder river. The transportation was overseen by the deputy mayor of Szczecin, Zdzisław Pacała.
The monument was unveiled on 3 September 1979, near the 40th anniversary of the beginning of the Second World War, which would be on 1 September which was Saturday. The monument was unveiled by Stanisław Kowalczyk, Minister of Interior. At the same time, the Council of State of the Republic of Poland awarded the city with the First Class Order of the Banner of Labour, in recognition of its population's contribution to the development of the country.
Characteristics
The monument is located in the city of Szczecin, Poland, located at the Bright Meadows Square, at the boundary with the Jan Kasprowicz Park. It consists of three bronze sculptures of eagles with spread wings, each placed on a steel column with a square base. The three birds are meant to symbolize three generations of Polish inhabitants of the city. That includes the Polish people who lived in the city prior to the end of the Second World War in 1945, people who moved to, and rebuilt the city after the end of the conflict, in place of mostly German population, who left or were deported, and the children of the new population, who further developed the city.
The monument has a total height of 22.5 m (73.82 ft.). The lowest eagle is placed 7.7 m (25.26 ft.) from the ground, and each eagle has a wingspan of 6.5 m (21.33 ft.), and together they weigh 60 tonnes. The columns are embedded 4 m (13.12 ft.) deep into the ground and in the 150-tonne concrete block. The outer layer of the collums is covered in the stainless steel. In total, the columns weigh 83 tonnes, of which 10 tons are the stainless steel. Underground, below the monument is located a room from which can be accessed two ladders hidden within the columns, which lead to the inside of the eagle sculptures, which can be accessed by conservators.
Around the monument are placed plaques with the names of the people involved in its creation.
References
1979 establishments in Poland
1979 sculptures
Buildings and structures completed in 1979
Monuments and memorials in Szczecin
Outdoor sculptures in Szczecin
Sculptures of eagles
Animal sculptures in Poland
Colossal statues
Bronze sculptures in Poland
Steel sculptures | Monument to the Polish Endeavor | [
"Physics",
"Mathematics"
] | 1,373 | [
"Quantity",
"Colossal statues",
"Physical quantities",
"Size"
] |
75,062,192 | https://en.wikipedia.org/wiki/Cardiovascular%E2%80%93kidney%E2%80%93metabolic%20syndrome | Cardiovascular–kidney–metabolic syndrome (CKM syndrome) is a multisystem disorder of the metabolic, renal and cardiovascular systems. The interactions between metabolic risk factors, such as type 2 diabetes and obesity, with chronic kidney disease and cardiovascular disorders lead to an increased mortality risk and significant impact on morbidity.
See also
Cardiorenal syndrome
References
Syndromes affecting the cardiovascular system
Syndromes affecting the kidneys
Metabolic disorders | Cardiovascular–kidney–metabolic syndrome | [
"Chemistry"
] | 87 | [
"Metabolic disorders",
"Metabolism"
] |
75,063,298 | https://en.wikipedia.org/wiki/List%20of%20earliest%20tools | The following table attempts to list the oldest-known Paleolithic and Paleo-Indian sites where hominin tools have been found. It includes sites where compelling evidence of hominin tool use has been found, even if no actual tools have been found.
Stone tools preserve more readily than tools of many other materials. So the oldest tools that we can find in many areas are going to be stone tools. It could be that these tools were once accompanied by, or even preceded by, non-stone tools that we cannot find because they did not preserve.
Similarly, hard materials like bone or shell are more likely than softer materials to leave discernible cut marks on bone. Bamboo has been shown to leave cut marks on bone that are harder to see than cut marks by stone. So the earliest evidence of tool use that we are likely to find are often cut marks made on bone by stone or shell tools.
Therefore the reader should not assume that the items on this list represent the earliest uses of tools in each area, but rather the earliest uses of tools that have been found.
Because it focuses on only the earliest evidence of tools, and since the earliest evidence is biased towards stone by stone's increased likelihood of preservation, this page necessarily omits mention of many significant ancient tools of non-stone materials simply because those cases are not among the earliest found within their geographic area. See Timeline of historic inventions for other noteworthy tools and other inventions.
With its focus on tools, this list also omits some sites with the earliest evidence for the existence of hominins, but without evidence for tools. Many such sites have hominin bones, teeth, or footprints, but unless they also include evidence for tools or tool use, they are omitted here.
This list excludes tools and tool use attributed to non-hominin species. See Tool use by non-humans.
Since there are far too many hominin tool sites to list on a single page, this page attempts to list the 6 or fewer top candidates for oldest tool site within each significant geographic area.
Geographic areas covered
Africa
East Africa
North Africa
Southern Africa
West Africa
Americas
North America
South America
Asia
East Asia
Island Southeast Asia - Islands between Sunda Shelf and Sahul, not connected to either one during the Last Glacial Maximum
South Asia
Sunda Shelf
West Asia
Europe
Eastern Europe
Western Europe
Sahul - Australia and New Guinea
Indian Ocean
For much of the 20th century, a "Clovis first" idea dominated American archeology. Many sites with dates too old to be compatible with "Clovis first" were published, but these were mostly dismissed under the hegemony of "Clovis first." Meanwhile some indigenous archeologists insisted throughout the "Clovis first" era that the peopling of the Americas was much older than Clovis. Recent publications with very strong evidence for pre-Clovis sites seem to have ended the hegemony of "Clovis first."
List of tools
See also
Hominini
List of human evolution fossils
Stone Age
Stone tool
Timeline of historic inventions
Tool use by non-humans
References
Tools
Hand tools
Archaeology-related lists
Archaeological sites | List of earliest tools | [
"Engineering"
] | 639 | [
"Human–machine interaction",
"Hand tools"
] |
61,366,529 | https://en.wikipedia.org/wiki/Let%20Nature%20Sing | "Let Nature Sing" is a single released by the Royal Society for the Protection of Birds on 26 April 2019, consisting of 2 minutes 32 seconds of British birdsong. The track was mixed by Adrian Thomas, Sam Lee and Bill Barclay, and released by the RSPB through Horus Music. The single was created to raise awareness of threats to birds and its release was timed to coincide with International Dawn Chorus Day on 5 May 2019. It reached number 18 on the UK Singles Chart, marking the first time a recording solely of birds had entered the charts, and reached number 1 on the UK Singles Sales Chart.
Production
To raise awareness of the decline in birds over the last 50 years, the RSPB recruited the creative agency Glimpse to create a campaign to bring nature into popular culture. Part of the campaign was for a single to be released and enter the charts for International Dawn Chorus Day on 5 May 2019.
While producing the RSPB Guide to Birdsong, the author Adrian Thomas recorded samples of many different British bird songs between 2016 and 2019. Thomas then mixed some of these recordings together into a demo. Thomas then recruited the help of Bill Barclay, the musical director at the Globe Theatre, and the folk musician Sam Lee to arrange the recordings into a track. The final mix was produced by Andrew Mellor, recording engineer of the Philadelphia Orchestra.
To coincide with the release of the track, the RSPB organised a panel on "the musicality of nature" hosted by BBC Radio 6 presenter Shaun Keaveny, with Eliza Doolittle, Chrissie Rhodes of The Shires, and Sam Lee. The track was remixed by Diplo for the Nick Grimshaw drivetime show, creating a "donk" version.
Featured birds
The song features the songs of many different species, ranging from very common garden birds such as the blackbird and robin to endangered and rare species such as cranes, of which only a few pairs are found in the UK. These include:
Cuckoo
Nightingale
Wren
Blackbird
Great spotted woodpecker
Robin
Collared dove
Crane
Curlew
Lapwing
Swift
Bittern
Turtle dove
Chiffchaff
Snipe
Blackcap
Swallow
Great tit
Sedge warbler
Grasshopper warbler
Skylark
Song thrush
Nightjar
Tawny owl
Music video
The video, performed by Drew Colby, uses shadowgraphy or "hand shadow puppetry" to show two birds struggling to find food for their chicks. Colby used hand shadows to produce the images of birds, spiders and landscapes, which were there composited together digitally. Text at the end of the video explains that since 1966, the UK has lost over 40 million birds and that "time is running out to save the rest". The RSPB also created a subtitled video, highlighting the name of each bird as it sings.
Reception
Andy Welch, writing for The Guardian, called "Let Nature Sing" "strangely comforting and a welcome sound for anyone who has ever enjoyed a dawn chorus". Joe Shute in the Daily Telegraph described its appearance during The Official Chart Show as "rather magical".
Chart performance
"Let Nature Sing" debuted at number 11 in the mid-week chart, and reached number 3 in the Official Trending Chart, with a final position of 18 in the full weekly chart. The single was the best-selling of the week, with 23,500 units sold.
Weekly charts
See also
Birdsong (radio channel)
References
External links
Let Nature Sing campaign page
"Let Nature Sing" on YouTube
Bird sounds
Songs about birds
Environmental songs
Music videos featuring puppetry
Royal Society for the Protection of Birds
2019 singles
Visual arts by animals
2019 songs | Let Nature Sing | [
"Biology"
] | 728 | [
"Ethology",
"Behavior",
"Animals",
"Visual arts by animals"
] |
61,366,790 | https://en.wikipedia.org/wiki/Deriaz%20turbine | The Deriaz turbine, presented by engineer Paul Deriaz, was the first diagonal hydraulic pump-turbine to be designed. In contrast to most hydraulic machines, the flow in a Deriaz turbine does not follow a full axial nor radial direction but is a diagonal mixture of the two. Deriaz turbines, like Kaplan turbines, can also have adjustable runner blades to reach highest efficiencies at variable discharge (double regulation). Deriaz turbines are installed at the Sir Adam Beck Pump Generating Station at Niagara Falls.
The combined use of adjustable runner blades with moving guide vanes allows Deriaz pump-turbine to reach high performance under a large range of working conditions. This makes the Deriaz pump-turbine an extremely suitable turbomachine solution for high variable load. Recent investigation supported by experimental data and computational fluid dynamics (CFD) simulations, shows clearly how a downsized prototype preserves versatility over a wide range of partial load for pumping and generating modes.
As the adjustment of runner blades is mechanically complex, Deriaz turbines with fixed blades have been developed. The adjustment to variable discharge is realized by variable runner speed based on modern inverter technology.
References
Turbines | Deriaz turbine | [
"Chemistry"
] | 242 | [
"Turbines",
"Turbomachinery"
] |
61,368,721 | https://en.wikipedia.org/wiki/Molly%20Wright%20Steenson | Molly Wright Steenson (born 1971) is an American professor of design and a historian of architecture and technology. Currently, Molly is the president and CEO of the American Swedish Institute. Previously, she was the Carnegie Mellon University Vice Provost for Faculty, K&L Gates Associate Professor of Ethics and Computational Technologies, and Senior Associate Dean for Research in the College of Fine Arts at Carnegie Mellon University.
Life and career
Steenson is a historian of design, architecture, and the history of those concepts alongside cybernetics and artificial intelligence. Her current research focuses on the idea of artificial intelligence and how it's viewed and portrayed in contemporary media and culture. She argues that our ideas of artificial intelligence are outdated and this inhibits peoples' ability to understand what it really is. Her book Architectural Intelligence: How Designers & Architects Created the Digital Landscape, published with Graham Foundation support, combines "an architectural history of interactivity and an interactive history of architecture."
Steenson holds a PhD in architecture from Princeton University, a Master's in Environmental Design from Yale School of Architecture, and a BA in German from the University of Wisconsin–Madison.
Publications
Books
Architectural Intelligence: How Designers & Architects Created the Digital Landscape (MIT Press, 2017)
Bauhaus Futures (MIT Press, 2019), co-edited with Laura Forlano & Mike Ananny.
Articles
"Beyond the Personal and Private: Modes of Mobile Phone Sharing in India," The Reconstruction of Space and Time: Mobile Communication Practices (2008)
"Interfaces to the Subterranean," Cabinet 41 (summer 2011) - about postal services and pneumatic tube systems
References
External links
Personal website
1971 births
Living people
Architectural design
Carnegie Mellon University faculty
Princeton University alumni
Yale School of Architecture alumni
University of Wisconsin–Madison College of Letters and Science alumni
American women historians
American architectural historians
Historians of technology
21st-century American historians
21st-century American women writers | Molly Wright Steenson | [
"Engineering"
] | 382 | [
"Design",
"Architectural design",
"Architecture"
] |
61,369,588 | https://en.wikipedia.org/wiki/Topswops | Topswops (and the variants Topdrops, Bottomswops and Bottomdrops) are mathematical problems devised and analysed by the British mathematician John Conway in 1973. Contrary to other games and problems introduced by Conway, these problems have not received much attention from the scientific community. Two famous mathematicians who have contributed to the problem are Martin Gardner and Donald Knuth.
Formulation
In each variant of the problem, Conway uses a deck of playing cards. Since the numerical values of the deck are only relevant, only one suit is used. This is mathematically equivalent to a row of integers from to . A shuffled pile of cards is written as .
Topswops
For topswops the following algorithm is applied:
Consider the first card from the pile (which is )
Take the first cards from the pile
Swap these cards and place them back on the pile
Repeat step 1, 2 and 3 until the top card is
The final configuration of the row always starts with . The topswops problem is occasionally named differently, with naming including deterministic pancake problem, topswops, topswaps, reverse card shuffle and fannkuch.
The problem formulated by Conway is the following:
Which initial configuration leads to the maximum number of 'swops' before the algorithm terminates?
In literature there are some attempts to find lower and upper bounds for the number of iterations .
Theorem: is bounded by .
Proof by Herbert S. Wilf: Consider a permutation to of the row to . As an example, we consider . We are specifically interested in numbers which are at 'the correct position'. These are: 2, 5, 9, 10, 12. We define the Wilf number as .
Claim: after each iteration of the algorithm, the Wilf number increases.
Proof: We perform one iteration of the algorithm. Every number at 'the correct position' and larger than , leaves the Wilf number unchanged. The remaining numbers at 'the correct position' will in general not be at 'the correct position' anymore. Nevertheless, the 's number is at the correct position. And since the sum of the first Wilf numbers is always smaller than the Wilf number of , the total Wilf number always increases (with at least 1 per iteration of the algorithm).
The maximal Wilf number is found when each number is at the correct position. So the maximal Wilf number is . By refining the proof, the given upper bound can be proven to be a real upper bound for the number of iterations.
Theorem: is bounded by the th Fibonacci number.
Proof by Murray S. Klamkin: Suppose that during the algorithm, the first number takes on in total distinct values.
Claim: .
Proof: We prove the claim by mathematical induction. For , the algorithm directly terminates, hence, . Thus and since the claim is proven.
We now take some . All values that takes on, are ordered and can be written as: . Suppose that the largest value of these values, which is , occurs for the first time at position during iteration of the algorithm. Denote . During the 'th iteration, we know and . The remaining iterations will always retain . Hence can now take on at most values. Using induction for , it follows that and also that .
Suppose we would exchange and in iteration Then and the algorithm terminates; . During the algorithm, we are sure that both and have never been at position , unless .
Suppose . Then since takes on at most distinct values. So it follows that .
Suppose . Then since takes on at most distinct values. Using the claim, it follows that . This proves the theorem.
Besides these results, Morales and Sudborough have recently proven that the lower bound for is a quadratic function in . The optimal values are, however, still unknown. There have been several attempts to find the optimal values, for example by A. Pepperdine. For rows with 19 or fewer numbers, the exact solution is known. Larger rows only have lower bounds, which is shown on the right.
It is yet unknown whether this problem is NP-hard.
Topdrops
A similar problem is topdrops, where the same playing cards are used. In this problem, the first card of the pile is shown (and has value ). Take the first cards of the pile, change the order and place them back on the bottom of the pile (which contrasts topswops, where the cards are placed at the top). This problem allows for infinite loops. As an example, we consider the row 2,1,3,4. By applying the algorithm, the following sequence is obtained:
2 1 3 4
3 4 1 2
2 1 4 3
4 3 1 2
2 1 3 4
whereafter the original row is found again.
Botswops
In this variant, the bottom card of the pile is taken (and again named ). Then the first cards of the pile are swapped. Unless the bottom card is the highest card in the pile, nothing happens. This makes the problem uninteresting due to the limited behaviour.
Botdrops
The final variant is botdrops where the bottom card of the pile is taken (again ). In this variant, the bottom cards are swapped.
References
External links
OEIS: page 375 (topswops)
OEIS: page 376 (topswops which ends up sorted)
Rosetta code: Computing Topswops in multiple programming languages
Topswops competition to compute the maximal number of iterations
John Horton Conway
Recreational mathematics | Topswops | [
"Mathematics"
] | 1,118 | [
"Recreational mathematics"
] |
61,369,995 | https://en.wikipedia.org/wiki/List%20of%20reptile%20genera | List of reptile genera lists the vertebrate class of reptiles by living genus, spanning two subclasses.
Subclass Anapsida
Order Testudinata (turtles)
Turtles are reptiles of the order Testudines characterized by a special bony or cartilaginous shell developed from their ribs and acting as a shield.
Suborder Pleurodira
Source:
Superfamily Cheloides
Family Chelidae
Genus Acanthochelys
Genus Chelodina
Genus Chelus - mata mata
Genus Elseya
Genus Elusor - Mary River turtle
Genus Emydura
Genus Flaviemys - Manning River snapping turtle
Genus Hydromedusa
Genus Mesoclemmys
Genus Myuchelys
Genus Phrynops
Genus Platemys - twist-necked turtle
Genus Pseudemydura - western swamp turtle
Genus Ranacephala - Hoge's side-necked turtle
Genus Rheodytes
Genus Rhinemys - red side-necked turtle
Superfamily Pelomedusoides
Family Pelomedusidae
Genus Pelomedusa - African helmeted turtle
Genus Pelusios
Family Podocnemididae
Genus Erymnochelys - Madagascan big-headed turtle
Genus Peltocephalus - big-headed Amazon River turtle
Genus Podocnemis
Suborder Cryptodira
Source:
Clade Americhelydia
Family Chelydridae
Genus Chelydra
Genus Macrochelys
Superfamily Chelonioidea
Family Cheloniidae
Genus Caretta - loggerhead sea turtle
Genus Chelonia - green sea turtle
Genus Eretmochelys - hawksbill sea turtle
Genus Lepidochelys - ridley sea turtle
Genus Natator - flatback sea turtle
Family Dermochelyidae
Genus Dermochelys - leatherback sea turtle
Superfamily Kinosternoidea
Family Dermatemydidae
Genus Dermatemys - Central American river turtle
Family Kinosternidae
Genus Claudius - narrow-bridged musk turtle
Genus Kinosternon
Genus Staurotypus
Genus Sternotherus
Superfamily Testudinoidea
Family Emydidae
Genus Actinemys
Genus Clemmys - spotted turtle
Genus Chrysemys
Genus Deirochelys - chicken turtle
Genus Emydoidea - Blanding's turtle
Genus Emys
Genus Glyptemys
Genus Graptemys
Genus Malaclemys - diamondback terrapin
Genus Pseudemys
Genus Terrapene - box turtle
Genus Trachemys
Family Geoemydidae
Genus Batagur - including part of Kachuga
Genus Cuora - Asian box turtle
Genus Cyclemys
Genus Geoclemys - black pond turtle
Genus Geoemyda
Genus Hardella - brahminy river turtle
Genus Heosemys - formerly in Geoemyda
Genus Leucocephalon - Sulawesi forest turtle, formerly in Geoemyda and Heosemys
Genus Malayemys
Genus Mauremys - including Annamemys, Cathaiemys and Emmenia
Genus Melanochelys
Genus Morenia
Genus Notochelys - Malayan flat-shelled turtle
Genus Orlitia - Malaysian giant turtle
Genus Pangshura - formerly in Kachuga
Genus Rhinoclemmys
Genus Sacalia
Genus Siebenrockiella - formerly under Heosemys
Genus Vijayachelys - cane turtle, formerly in Geoemyda and Heosemys
FamilyPlatysternidae
Genus Platysternon
Family Testudinidae - tortoise
Genus Aldabrachelys
Genus Astrochelys
Genus Centrochelys
Genus Chelonoidis
Genus Chersina - angulate tortoise
Genus Chersobius
Genus Geochelone
Genus Gopherus
Genus Homopus
Genus Indotestudo
Genus Kinixys
Genus Malacochersus - pancake tortoise
Genus Manouria
Genus Psammobates
Genus Pyxis
Genus Stigmochelys - leopard tortoise
Genus Testudo
Superfamily Trionychia
Family Carettochelyidae
Genus Carettochelys - pig-nosed turtle
Family Trionychidae
Genus Amyda
Genus Apalone
Genus Chitra
Genus Cyclanorbis
Genus Cycloderma
Genus Dogania - Malayan softshell turtle
Genus Lissemys
Genus Nilssonia
Genus Palea - wattle-necked softshell turtle
Genus Pelochelys
Genus Pelodiscus
Genus Rafetus
Genus Trionyx
Subclass Diapsida
Superorder Lepidosauria
The Lepidosauria (from Greek meaning scaled lizards) are reptiles with overlapping scales. This subclass includes Squamata and Rhynchocephalia. It is a monophyletic group and therefore contains all descendants of a common ancestor.
Order Rhynchocephalia
Rhynchocephalia is an order of lizard-like reptiles that includes only one living species of tuatara, which in turn has two subspecies (Sphenodon punctatus punctatus and Sphenodon punctatus guntheri), which only inhabit parts of New Zealand.
Family Sphenodontidae
Genus Sphenodon - tuatara
Order Squamata
Squamata is the largest order of reptiles, comprising lizards, snakes and amphisbaenians (worm lizards), which are collectively known as squamates or scaled reptiles. With over 10,000 species,
Suborder Anguimorpha
Family Anguidae
Genus Abronia
Genus Anguis
Genus Dopasia
Genus Elgaria
Genus Gerrhonotus
Genus Hyalosaurus - Koelliker's glass lizard
Genus Ophisaurus
Genus Pseudopus
Family Anniellidae
Genus Anniella - American legless lizard
Family Diploglossidae
Genus Celestus
Genus Diploglossus
Genus Ophiodes
Family Helodermatidae
Genus Heloderma
Family Lanthanotidae
Genus Lanthanotus
Family Shinisauridae
Genus Shinisaurus
Family Varanidae
Genus Varanus - monitor lizard
Family Xenosauridae.
Genus Xenosaurus
Infraorder Gekkota
Family Dibamidae
Genus Anelytropsis
Genus Dibamus
Family Gekkonidae
Genus Afroedura
Genus Afrogecko
Genus Agamura
Genus Ailuronyx
Genus Alsophylax
Genus Altiphylax
Genus Ancylodactylus
Genus Bauerius
Genus Blaesodactylus
Genus Bunopus
Genus Calodactylodes
Genus Chondrodactylus
Genus Christinus
Genus Cnemaspis
Genus Crossobamon
Genus Cryptactites - Peringuey's leaf-toed gecko
Genus Cyrtodactylus
Genus Cyrtopodion
Genus Dixonius
Genus Dravidogecko
Genus Ebenavia
Genus Elasmodactylus
Genus Geckolepis
Genus Gehyra
Genus Gekko
Genus Goggia
Genus Hemidactylus
Genus Hemiphyllodactylus
Genus Heteronotia
Genus Homopholis
Genus Kolekanos
Genus Lakigecko
Genus Lepidodactylus
Genus Luperosaurus
Genus Lygodactylus
Genus Matoatoa
Genus Mediodactylus
Genus Microgecko
Genus Nactus
Genus Narudasia
Genus Pachydactylus
Genus Paragehyra
Genus Paroedura
Genus Parsigecko - Ziaie's Pars-gecko
Genus Perochirus
Genus Phelsuma
Genus Pseudoceramodactylus - Gulf short-fingered gecko
Genus Pseudogekko
Genus Ptenopus
Genus Ptychozoon
Genus Ramigekko - Swartberg African leaf-toed gecko
Genus Rhinogekko
Genus Rhoptropella - Namaqua day gecko
Genus Rhoptropus
Genus Stenodactylus
Genus Tenuidactylus
Genus Trachydactylus
Genus Trigonodactylus
Genus Tropiocolotes
Genus Urocotyledon
Genus Uroplatus
Family Pygopodidae
Genus Aprasia
Genus Delma
Genus Lialis
Genus Ophidiocephalus - bronzeback snake-lizard
Genus Paradelma - brigalow scaly-foot
Genus Pletholax - slender slider
Genus Pygopus
Suborder Iguania
Family Agamidae
Genus Acanthocercus
Genus Acanthosaura - mountain horned dragons
Genus Agama
Genus Amphibolurus - lashtail dragons
Genus Aphaniotis
Genus Bronchocela
Genus Bufoniceps - Laungwala long-headed lizard
Genus Calotes
Genus Ceratophora
Genus Chelosania - ring-tailed dragon
Genus Chlamydosaurus - frilled-neck lizard
Genus Complicitus - blackthroated bloodsucker
Genus Cophotis
Genus Coryphophylax
Genus Cristidorsa
Genus Cryptagama - gravel dragon
Genus Ctenophorus - comb-bearing dragons
Genus Dendragama
Genus Diploderma
Genus Diporiphora - two-lined dragons
Genus Draco - 'flying' lizards or gliding lizards
Genus Gonocephalus
Genus Gowidon
Genus Harpesaurus
Genus Hydrosaurus
Genus Hypsicalotes
Genus Hypsilurus - rainforest dragons
Genus Intellagama - Australian water dragon, formerly placed in Physignathus
Genus Japalura
Genus Laudakia
Genus Leiolepis
Genus Lophocalotes
Genus Lophognathus - sometimes placed in Amphibolurus
Genus Lophosaurus - forest dragons
Genus Lyriocephalus - hump-nosed lizard, lyreshead lizard
Genus Malayodracon
Genus Mantheyus
Genus Microauris
Genus Mictopholis - see Pseudocalotes
Genus Moloch - thorny devil
Genus Monilesaurus
Genus Otocryptis
Genus Paralaudakia - sometimes included in Laudakia
Genus Pelturagonia
Genus Phoxophrys
Genus Phrynocephalus
Genus Physignathus - water dragons
Genus Pogona - bearded dragons
Genus Psammophilus
Genus Pseudocalotes
Genus Pseudocophotis
Genus Pseudotrapelus
Genus Ptyctolaemus
Genus Rankinia - heath dragon
Genus Saara
Genus Salea
Genus Sarada - large fan-throated lizards
Genus Sitana - fan-throated lizards
Genus Trapelus
Genus Tropicagama
Genus Tympanocryptis - earless dragons
Genus Uromastyx
Genus Xenagama
Family Chamaeleonidae - chameleon
Genus Archaius
Genus Bradypodion
Genus Brookesia
Genus Calumma
Genus Chamaeleo
Genus Furcifer
Genus Kinyongia
Genus Nadzikambia
Genus Palleon
Genus Rieppeleon
Genus Rhampholeon
Genus Trioceros
Family Corytophanidae
Genus Basiliscus
Genus Corytophanes
Genus Laemanctus
Family Crotaphytidae
Genus Crotaphytus
Genus Gambelia
Family Hoplocercidae
Genus Enyalioides
Genus Hoplocercus - weapontail
Genus Morunasaurus
Family Iguanidae
Genus Amblyrhynchus - marine iguana
Genus Brachylophus
Genus Cachryx
Genus Conolophus
Genus Ctenosaura
Genus Cyclura
Genus Dipsosaurus - desert iguana
Genus Iguana
Genus Sauromalus - chuckwalla
Family Leiosauridae
Genus Anisolepis
Genus Diplolaemus
Genus Enyalius
Genus Leiosaurus
Genus Pristidactylus
Genus Urostrophus
Family Liolaemidae
Genus Ctenoblepharys
Genus Liolaemus
Genus Phymaturus
Family Opluridae
Genus Chalarodon
Genus Oplurus
Family Phrynosomatidae
Genus Callisaurus - zebra-tailed lizard
Genus Cophosaurus - greater earless lizard
Genus Holbrookia
Genus Petrosaurus - California rock lizard
Genus Phrynosoma - horned lizard
Genus Sceloporus - spiny lizard
Genus Uma - fringe-toed lizard
Genus Urosaurus
Genus Uta - side-blotched lizard
Family Polychrotidae
Genus Polychrus
Family Tropiduridae
Genus Eurolophosaurus
Genus Microlophus
Genus Plica
Genus Stenocercus
Genus Strobilurus
Genus Tropidurus
Genus Uracentron - sometimes in Tropidurus
Genus Uranoscodon
Superfamily Lacertoidea
Family Alopoglossidae - recently split from the Gymnophthalmidae
Genus Alopoglossus
Genus Ptychoglossus
Family Amphisbaenidae
Genus Amphisbaena - worm lizard
Genus Ancylocranium
Genus Baikia - West African worm lizard
Genus Chirindia
Genus Cynisca
Genus Dalophia
Genus Geocalamus
Genus Leposternon
Genus Loveridgea
Genus Mesobaena
Genus Monopeltis
Genus Zygaspis
Family Bipedidae
Genus Bipes
Family Blanidae
Genus Blanus
Family Cadeidae
Genus Cadea
Family Gymnophthalmidae
Genus Acratosaura
Genus Adercosaurus
Genus Alexandresaurus
Genus Amapasaurus - four-toed amapasaurus
Genus Anadia
Genus Andinosaura
Genus Anotosaura
Genus Arthrosaura
Genus Bachia
Genus Calyptommatus
Genus Caparaonia
Genus Centrosaura
Genus Cercosaura
Genus Colobodactylus
Genus Colobosaura
Genus Colobosauroides
Genus Dendrosauridion
Genus Dryadosaura
Genus Echinosaura
Genus Ecpleopus
Genus Euspondylus
Genus Gelanesaurus
Genus Gymnophthalmus
Genus Heterodactylus
Genus Iphisa
Genus Kaieteurosaurus
Genus Kataphraktosaurus
Genus Leposoma
Genus Loxopholis
Genus Macropholidus
Genus Magdalenasaura
Genus Marinussaurus
Genus Micrablepharus
Genus Neusticurus
Genus Nothobachia
Genus Oreosaurus
Genus Pantepuisaurus
Genus Petracola
Genus Pholidobolus
Genus Placosoma
Genus Potamites
Genus Procellosaurinus
Genus Proctoporus
Genus Psilops
Genus Rhachisaurus
Genus Rheosaurus
Genus Riama
Genus Riolama
Genus Rondonops
Genus Scriptosaura
Genus Selvasaura
Genus Stenolepis
Genus Tretioscincus
Genus Vanzosaura
Genus Wilsonosaura
Genus Yanomamia
Family Lacertidae
Genus Acanthodactylus
Genus Adolfus
Genus Algyroides
Genus Anatololacerta
Genus Apathya
Genus Archaeolacerta - Bedriaga's rock lizard
Genus Atlantolacerta - Atlas dwarf lizard
Genus Australolacerta - southern rock lizard
Genus Congolacerta
Genus Dalmatolacerta - sharp-snouted rock lizard
Genus Darevskia
Genus Dinarolacerta
Genus Eremias
Genus Gallotia
Genus Gastropholis
Genus Heliobolus
Genus Hellenolacerta - Greek rock lizard
Genus Holaspis
Genus Iberolacerta
Genus Ichnotropis
Genus Iranolacerta
Genus Lacerta
Genus Latastia
Genus Meroles
Genus Mesalina
Genus Nucras
Genus Omanosaura
Genus Ophisops
Genus Parvilacerta
Genus Pedioplanis
Genus Philochortus
Genus Phoenicolacerta
Genus Podarcis
Genus Poromera
Genus Psammodromus
Genus Pseuderemias
Genus Scelarcis - Moroccan rock lizard
Genus Takydromus
Genus Teira - Madeiran wall lizard
Genus Timon
Genus Tropidosaura
Genus Vhembelacerta - Soutpansberg rock lizard
Genus Zootoca - viviparous lizard
Family Rhineuridae
Genus Rhineura
Family Teiidae
Genus Ameiva
Genus Ameivula
Genus Aspidoscelis
Genus Aurivela
Genus Callopistes
Genus Cnemidophorus
Genus Contomastix
Genus Crocodilurus
Genus Dicrodon
Genus Dracaena
Genus Glaucomastix
Genus Holcosus
Genus Kentropyx
Genus Medopheos - Bocourt's ameiva
Genus Pholidoscelis
Genus Salvator
Genus Teius
Genus Tupinambis
Family Trogonophidae.
Genus Agamodon
Genus Diplometopon - Zarudny's worm lizard
Genus Pachycalamus - short worm lizard
Genus Trogonophis - checkerboard worm lizard
Infraorder Scincomorpha
Family Cordylidae
Genus Chamaesaura
Genus Cordylus
Genus Hemicordylus
Genus Karusasaurus
Genus Namazonurus
Genus Ninurta
Genus Ouroborus - armadillo girdled lizard
Genus Platysaurus
Genus Pseudocordylus
Genus Smaug
Family Gerrhosauridae
Genus Broadleysaurus - Sudan plated lizard
Genus Cordylosaurus - blue-black plated lizard
Genus Gerrhosaurus
Genus Matobosaurus
Genus Tetradactylus
Genus Tracheloptychus - keeled plated lizards
Genus Zonosaurus
Family Scincidae
Genus Egernia
Genus Lygosoma
Genus Parotosaurus - see Sphenomorphus
Genus Sphenomorphus
Genus Tiliqua - blue-tongued skink
Family Xantusiidae - night lizard
Genus Cricosaura - Cuban night lizard
Genus Lepidophyma
Genus Xantusia
Suborder Serpentes - snakes
Infraorder Alethinophidia
Family Acrochordidae
Genus Acrochordus
Family Aniliidae
Genus Anilius
Family Anomochilidae
Genus Anomochilus
Family Atractaspididae
Genus Amblyodipsas
Genus Aparallactus
Genus Atractaspis
Genus Brachyophis
Genus Chilorhinophis
Genus Homoroselaps
Genus Hypoptophis
Genus Macrelaps
Genus Micrelaps
Genus Poecilopholis
Genus Polemon
Genus Xenocalamus
Family Boidae
Genus Acrantophis
Genus Boa
Genus Calabaria - Calabar python
Genus Candoia
Genus Charina
Genus Chilabothrus
Genus Corallus
Genus Epicrates
Genus Eryx
Genus Eunectes
Genus Lichanura
Genus Sanzinia
Family Bolyeriidae,
Genus Bolyeria - Round Island burrowing boa
Genus Casarea - Round Island boa
Family Colubridae
Genus Adelophis
Genus Adelphicos
Genus Adelphostigma
Genus Aeluroglena
Genus Afronatrix - African brown water snake
Genus Ahaetulla
Genus Alsophis
Genus Amastridium
Genus Amnesteophis
Genus Amnisiophis
Genus Amphiesma - buff striped keelback
Genus Amphiesmoides
Genus Anoplohydrus
Genus Apographon
Genus Apostolepis
Genus Aprosdoketophis
Genus Arcanumophis
Genus Archelaphe
Genus Argyrogena
Genus Arizona
Genus Arrhyton
Genus Aspidura
Genus Atractus
Genus Atretium
Genus Baliodryas
Genus Bamanophis
Genus Blythia
Genus Bogertophis
Genus Boiga
Genus Boiruna
Genus Borikenophis
Genus Caaeteboia - Amaral's ground snake
Genus Calamaria
Genus Calamodontophis
Genus Calamorhabdium
Genus Caraiba
Genus Carphophis
Genus Cemophora
Genus Cenaspis
Genus Cercophis - Schlegel's golden snake
Genus Chapinophis
Genus Chersodromus
Genus Chironius
Genus Chlorosoma
Genus Chrysopelea
Genus Clelia - Mussurana
Genus Clonophis - Kirtland's snake
Genus Coelognathus
Genus Collorhabdium
Genus Coluber - eastern racer
Genus Colubroelaps - Nguyenvansang's snake
Genus Coniophanes
Genus Conophis
Genus Conopsis
Genus Contia
Genus Coronelaps
Genus Coronella
Genus Crisantophis - Dunn's road guarder
Genus Crotaphopeltis
Genus Cryophis - Hallberg's cloud forest snake
Genus Cubophis
Genus Dasypeltis
Genus Dendrelaphis
Genus Dendrophidion
Genus Diadophis - ring-necked snake
Genus Diaphorolepis
Genus Dipsadoboa
Genus Dipsas
Genus Dispholidus - boomslang
Genus Ditaxodon - Hensel's snake
Genus Dolichophis
Genus Drepanoides
Genus Drymarchon
Genus Drymobius
Genus Drymoluber
Genus Dryophiops
Genus Echinanthera
Genus Eirenis
Genus Elaphe
Genus Elapoidis
Genus Elapomorphus
Genus Emmochliophis
Genus Enuliophis - Colombian longtail snake
Genus Enulius
Genus Erythrolamprus
Genus Etheridgeum
Genus Euprepiophis
Genus Eutrachelophis
Genus Farancia
Genus Ficimia
Genus Fowlea
Genus Geagras - Tehuantepec striped snake
Genus Geophis
Genus Gomesophis - Brazilian burrowing snake
Genus Gongylosoma
Genus Gonyosoma
Genus Grayia
Genus Gyalopion
Genus Haitiophis - Hispaniola racer
Genus Haldea
Genus Hapsidophrys
Genus Hebius
Genus Helicops
Genus Helophis - Schouteden's sun snake
Genus Hemerophis
Genus Hemorrhois
Genus Herpetoreas
Genus Heterodon
Genus Hierophis
Genus Hydrablabes
Genus Hydraethiops
Genus Hydrodynastes
Genus Hydromorphus
Genus Hydrops
Genus Hypsiglena
Genus Hypsirhynchus
Genus Ialtris
Genus Iguanognathus - spatula-toothed snake
Genus Imantodes
Genus Incaspis
Genus Isanophis - Boonsong's stream snake
Genus Lampropeltis - kingsnake
Genus Leptodeira
Genus Leptodrymus
Genus Leptophis
Genus Limnophis
Genus Liodytes
Genus Lioheterophis - Ihering's snake
Genus Liopeltis
Genus Lycodon
Genus Lycognathophis - Seychelles wolf snake
Genus Lygophis
Genus Lytorhynchus
Genus Macrocalamus
Genus Macroprotodon
Genus Magliophis
Genus Manolepis - ridgehead snake
Genus Masticophis
Genus Mastigodryas
Genus Meizodon
Genus Mopanveldophis
Genus Muhtarophis
Genus Mussurana
Genus Natriciteres
Genus Natrix
Genus Nerodia
Genus Ninia
Genus Nothopsis - rough coffee snake
Genus Oligodon
Genus Omoadiphas
Genus Oocatochus
Genus Opheodrys
Genus Opisthotropis
Genus Oreocalamus
Genus Oreocryptophis
Genus Orientocoluber - slender racer
Genus Oxybelis
Genus Oxyrhopus
Genus Palusophis
Genus Pantherophis
Genus Paraphimophis
Genus Phalotris
Genus Philodryas
Genus Philothamnus
Genus Phimophis
Genus Phrynonax
Genus Phyllorhynchus
Genus Pituophis
Genus Plagiopholis
Genus Platyceps
Genus Plesiodipsas - Alemán's snail-eater
Genus Pliocercus
Genus Proahaetulla
Genus Pseudagkistrodon
Genus Pseudalsophis
Genus Pseudelaphe
Genus Pseudoboa
Genus Pseudoeryx
Genus Pseudoficimia
Genus Pseudoleptodeira - false cat-eyed snake
Genus Pseudorabdion
Genus Pseudotomodon - false tomodon snake
Genus Pseudoxenodon
Genus Psomophis
Genus Ptyas
Genus Ptychophis - fanged water snake
Genus Rabdion
Genus Regina
Genus Rhabdophis
Genus Rhabdops
Genus Rhachidelus
Genus Rhadinaea
Genus Rhadinella
Genus Rhadinophanes
Genus Rhamnophis
Genus Rhinobothryum
Genus Rhinocheilus
Genus Rhynchocalamus
Genus Rodriguesophis
Genus Salvadora
Genus Saphenophis
Genus Scaphiodontophis
Genus Scaphiophis
Genus Scolecophis
Genus Senticolis
Genus Sibon
Genus Sibynophis
Genus Simophis
Genus Siphlophis
Genus Smithophis
Genus Sonora
Genus Sordellina - dotted brown snake
Genus Spalerosophis
Genus Spilotes
Genus Stegonotus
Genus Stenorrhina
Genus Stichophanes
Genus Storeria
Genus Symphimus
Genus Sympholis
Genus Synophis
Genus Tachymenis
Genus Taeniophallus
Genus Tantalophis - Oaxacan cat-eyed snake
Genus Tantilla
Genus Tantillita
Genus Telescopus - Old World catsnakes
Genus Tetralepis - bluebelly Java snake
Genus Thamnodynastes
Genus Thamnophis - garter snake
Genus Thermophis
Genus Thelotornis - twig snake
Genus Thrasops
Genus Tomodon
Genus Toxicodryas
Genus Trachischium
Genus Tretanorhinus
Genus Trimerodytes
Genus Trimetopon
Genus Trimorphodon
Genus Tropidoclonion
Genus Tropidodipsas
Genus Tropidodryas
Genus Tropidonophis
Genus Uromacer
Genus Urotheca
Genus Virginia - smooth earth snake
Genus Wallaceophis
Genus Wallophis - Indian smooth snake
Genus Xenelaphis
Genus Xenochrophis
Genus Xenodon
Genus Xenopholis
Genus Xenoxybelis
Genus Xyelodontophis - dagger-tooth vine snake
Genus Zamenis
Family Cyclocoridae
Genus Cyclocorus
Genus Hologerrhum
Genus Levitonius
Genus Myersophis
Genus Oxyrhabdium
Family Cylindrophiidae
Genus Cylindrophis
Family Elapidae
Genus Acanthophis
Genus Aipysurus
Genus Antaioserpens
Genus Aspidelaps
Genus Aspidomorphus
Genus Austrelaps
Genus Boulengerina
Genus Brachyurophis
Genus Bungarus
Genus Cacophis
Genus Calliophis
Genus Cryptophis
Genus Demansia
Genus Dendroaspis - mamba
Genus Denisonia
Genus Drysdalia
Genus Echiopsis
Genus Elapognathus
Genus Elapsoidea
Genus Emydocephalus
Genus Enhydrina
Genus Ephalophis - Grey's mudsnake
Genus Furina
Genus Hemachatus - rinkhals
Genus Hemiaspis
Genus Hemibungarus
Genus Homoroselaps
Genus Hoplocephalus
Genus Hydrelaps
Genus Hydrophis
Genus Incongruelaps
Genus Laticauda - sea krait
Genus Loveridgelaps
Genus Micropechis
Genus Micruroides
Genus Micrurus
Genus Naja
Genus Neelaps
Genus Notechis - tiger snake
Genus Ogmodon - Fiji snake
Genus Ophiophagus - king cobra
Genus Oxyuranus - taipan
Genus Parahydrophis - northern mangrove seasnake
Genus Parapistocalamus
Genus Paroplocephalus
Genus Pseudechis
Genus Pseudohaje
Genus Pseudonaja
Genus Rhinoplocephalus
Genus Salomonelaps
Genus Simoselaps
Genus Sinomicrurus
Genus Suta
Genus Thalassophis - anomalous sea snake
Genus Toxicocalamus
Genus Tropidechis - rough-scaled snake
Genus Vermicella
Genus Walterinnesia
Family Homalopsidae
Genus Bitia - keel-bellied water snake
Genus Brachyorrhos
Genus Calamophis
Genus Cantoria
Genus Cerberus
Genus Dieurostus - Dussumier's water snake
Genus Djokoiskandarus
Genus Enhydris
Genus Erpeton
Genus Ferania - Siebold's water snake
Genus Fordonia
Genus Gerarda
Genus Gyiophis
Genus Heurnia
Genus Homalophis
Genus Homalopsis
Genus Hypsiscopus
Genus Karnsophis
Genus Kualatahan
Genus Mintonophis
Genus Miralia
Genus Myanophis
Genus Myron
Genus Myrrophis
Genus Phytolopsis
Genus Pseudoferania
Genus Raclitia
Genus Subsessor
Genus Sumatranus
Family Lamprophiidae
Genus Boaedon
Genus Bothrolycus - Günther's black snake
Genus Bothrophthalmus - red-black striped snake
Genus Buhoma
Genus Chamaelycus
Genus Dendrolycus - Cameroon rainforest snake
Genus Gonionotophis
Genus Gracililima - black file snake
Genus Hormonotus
Genus Inyoka
Genus Lamprophis
Genus Limaformosa
Genus Lycodonomorphus
Genus Lycophidion
Genus Mehelya
Genus Montaspis - cream-spotted mountain snake
Genus Pseudoboodon
Family Loxocemidae
Genus Loxocemus
Family Pareidae
Genus Aplopeltura
Genus Asthenodipsas
Genus Pareas
Genus Xylophis
Family Prosymnidae
Genus Prosymna
Family Psammophiidae
Genus Dipsina - Dwarf beaked snake
Genus Hemirhagerrhis
Genus Kladirostratus - Branch's beaked snak
Genus Malpolon
Genus Mimophis
Genus Psammophis
Genus Psammophylax
Genus Rhamphiophis
Family Pseudaspididae
Genus Psammodynastes
Genus Pseudaspis - Mole snake
Genus Pythonodipsas - western keeled snake
Family Pseudoxyrhophiidae
Genus Alluaudina
Genus Amplorhinus
Genus Brygophis
Genus Compsophis
Genus Ditypophis - Günther's racer
Genus Dromicodryas
Genus Duberria
Genus Elapotinus
Genus Heteroliodon
Genus Ithycyphus
Genus Langaha
Genus Leioheterodon
Genus Liophidium
Genus Liopholidophis
Genus Lycodryas
Genus Madagascarophis
Genus Micropisthodon
Genus Pararhadinaea
Genus Parastenophis
Genus Phisalixella
Genus Pseudoxyrhopus
Genus Thamnosophis
Family Pythonidae
Genus Antaresia
Genus Apodora
Genus Aspidites
Genus Bothrochilus - Bismarck ringed python
Genus Leiopython
Genus Liasis
Genus Malayopython
Genus Morelia
Genus Nyctophilopython - Oenpelli python
Genus Python
Genus Simalia
Family Tropidophiidae
Genus Trachyboa
Genus Tropidophis
Family Uropeltidae
Genus Melanophidium
Genus Platyplectrurus
Genus Pseudoplectrurus - Karnataka burrowing snake
Genus Plectrurus
Genus Rhinophis
Genus Teretrurus
Genus Uropeltis
Family Viperidae
Genus Agkistrodon - Moccasin
Genus Atheris - Bush viper
Genus Atropoides - Picado's jumping pitviper
Genus Azemiops - Fea's viper
Genus Bitis - Puff adder
Genus Bothriechis - Palm-pitviper
Genus Bothrocophias - Toadheaded pit viper
Genus Bothrops - Lanceheads
Genus Calloselasma - Malayan pitviper
Genus Causus - Night adder
Genus Cerastes - Horned viper
Genus Cerrophidion - Montane pitviper
Genus Craspedocephalus - Pit viper
Genus Crotalus - Rattlesnakes
Genus Daboia - Day adder
Genus Deinagkistrodon - Hundred-pace pitviper
Genus Echis - Saw-scaled viper
Genus Eristicophis - McMahon's viper
Genus Garthius
Genus Gloydius - Asian moccasin
Genus Hypnale - Hump-nosed pit viper
Genus Lachesis - Bushmaster
Genus Macrovipera
Genus Metlapilcoatlus - Jumping pitviper
Genus Mixcoatlus - Mexican pit viper
Genus Montatheris - Kenya mountain viper
Genus Montivipera - Upland viper
Genus Ophryacus - Mexican horned pitviper
Genus Ovophis - Mountain pit viper
Genus Porthidium - Hognose pit viper
Genus Proatheris - Lowland viper
Genus Protobothrops - Pit viper
Genus Pseudocerastes - False-horned viper
Genus Sistrurus - Ground rattlesnake
Genus Trimeresurus - Asian lancehead
Genus Tropidolaemus - Temple viper
Genus Vipera - Palearctic viper
Family Xenodermidae
Genus Achalinus
Genus Fimbrios
Genus Parafimbrios
Genus Paraxenodermus
Genus Stoliczkia
Genus Xenodermus
Family Xenopeltidae
Genus Xenopeltis
Family Xenophidiidae
Genus Xenophidion
Infraorder Scolecophidia
Family Anomalepidae
Genus Anomalepis
Genus Helminthophis
Genus Liotyphlops
Genus Typhlophis
Family Gerrhopilidae
Genus Gerrhopilus
Genus Cathetorhinus
Family Leptotyphlopidae
Genus Epacrophis
Genus Epictia
Genus Habrophallos - Collared blind snake
Genus Leptotyphlops
Genus Mitophis
Genus Myriopholis
Genus Namibiana
Genus Rena
Genus Rhinoguinea
Genus Rhinoleptus - Villiers's blind snake
Genus Siagonodon
Genus Tetracheilostoma
Genus Tricheilostoma
Genus Trilepida
Family Typhlopidae
Genus Acutotyphlops
Genus Afrotyphlops
Genus Amerotyphlops
Genus Anilios
Genus Antillotyphlops
Genus Argyrophis
Genus Cubatyphlops
Genus Cyclotyphlops - Deharveng's blind snake
Genus Grypotyphlops
Genus Indotyphlops
Genus Letheobia
Genus Madatyphlops
Genus Malayotyphlops
Genus Ramphotyphlops
Genus Rhinotyphlops
Genus Sundatyphlops
Genus Typhlops
Genus Xerotyphlops
Family Xenotyphlopidae.
Genus Xenotyphlops
Division Archosauria
Archosaurs are a group of diapsid amniotes whose living representatives consist of birds and crocodilians. This group also includes all extinct dinosaurs, extinct crocodilian relatives, and pterosaurs.
Order Crocodilia
Crocodilia (or Crocodylia) is an order of mostly large, predatory, semiaquatic archosaurian reptiles, known as crocodilians.
Family Gavialidae
Genus Gavialis - gharial
Genus Tomistoma - false gharial
Family Alligatoridae
Genus Alligator
Genus Caiman
Genus Melanosuchus - black caiman
Genus Paleosuchus
Family Crocodylidae
Genus Crocodylus
Genus Mecistops
Genus Osteolaemus - dwarf crocodile
Order Saurischia
Cladistically birds are considered reptiles, but according to traditional taxonomy they are listed separately. Saurischia includes extinct relatives of birds, the "lizard hipped" dinosaurs. See List of bird genera.
See also
Reptile
List of California amphibians and reptiles
List of regional reptiles lists
List of snakes
Herping
References
External links
Reptile Database
Reptiles
Reptiles
Genera
Reptiles | List of reptile genera | [
"Biology"
] | 7,123 | [
"Lists of biota",
"Lists of animals",
"Animals"
] |
61,373,032 | https://en.wikipedia.org/wiki/Machine%20learning%20in%20physics | Applying machine learning (ML) (including deep learning) methods to the study of quantum systems is an emergent area of physics research. A basic example of this is quantum state tomography, where a quantum state is learned from measurement. Other examples include learning Hamiltonians, learning quantum phase transitions, and automatically generating new quantum experiments. ML is effective at processing large amounts of experimental or calculated data in order to characterize an unknown quantum system, making its application useful in contexts including quantum information theory, quantum technology development, and computational materials design. In this context, for example, it can be used as a tool to interpolate pre-calculated interatomic potentials, or directly solving the Schrödinger equation with a variational method.
Applications of machine learning to physics
Noisy data
The ability to experimentally control and prepare increasingly complex quantum systems brings with it a growing need to turn large and noisy data sets into meaningful information. This is a problem that has already been studied extensively in the classical setting, and consequently, many existing machine learning techniques can be naturally adapted to more efficiently address experimentally relevant problems. For example, Bayesian methods and concepts of algorithmic learning can be fruitfully applied to tackle quantum state classification, Hamiltonian learning, and the characterization of an unknown unitary transformation. Other problems that have been addressed with this approach are given in the following list:
Identifying an accurate model for the dynamics of a quantum system, through the reconstruction of the Hamiltonian;
Extracting information on unknown states;
Learning unknown unitary transformations and measurements;
Engineering of quantum gates from qubit networks with pairwise interactions, using time dependent or independent Hamiltonians.
Improving the extraction accuracy of physical observables from absorption images of ultracold atoms (degenerate Fermi gas), by the generation of an ideal reference frame.
Calculated and noise-free data
Quantum machine learning can also be applied to dramatically accelerate the prediction of quantum properties of molecules and materials. This can be helpful for the computational design of new molecules or materials. Some examples include
Interpolating interatomic potentials;
Inferring molecular atomization energies throughout chemical compound space;
Accurate potential energy surfaces with restricted Boltzmann machines;
Automatic generation of new quantum experiments;
Solving the many-body, static and time-dependent Schrödinger equation;
Identifying phase transitions from entanglement spectra;
Generating adaptive feedback schemes for quantum metrology and quantum tomography.
Variational circuits
Variational circuits are a family of algorithms which utilize training based on circuit parameters and an objective function. Variational circuits are generally composed of a classical device communicating input parameters (random or pre-trained parameters) into a quantum device, along with a classical Mathematical optimization function. These circuits are very heavily dependent on the architecture of the proposed quantum device because parameter adjustments are adjusted based solely on the classical components within the device. Though the application is considerably infantile in the field of quantum machine learning, it has incredibly high promise for more efficiently generating efficient optimization functions.
Sign problem
Machine learning techniques can be used to find a better manifold of integration for path integrals in order to avoid the sign problem.
Fluid dynamics
Physics discovery and prediction
A deep learning system was reported to learn intuitive physics from visual data (of virtual 3D environments) based on an unpublished approach inspired by studies of visual cognition in infants. Other researchers have developed a machine learning algorithm that could discover sets of basic variables of various physical systems and predict the systems' future dynamics from video recordings of their behavior. In the future, it may be possible that such can be used to automate the discovery of physical laws of complex systems. Beyond discovery and prediction, "blank slate"-type of learning of fundamental aspects of the physical world may have further applications such as improving adaptive and broad artificial general intelligence. In specific, prior machine learning models were "highly specialised and lack a general understanding of the world".
See also
Quantum computing
Quantum machine learning
Quantum annealing
Quantum neural network
HHL Algorithm
References
Machine learning
Quantum information science
Theoretical computer science
Quantum programming | Machine learning in physics | [
"Mathematics",
"Engineering"
] | 809 | [
"Theoretical computer science",
"Applied mathematics",
"Artificial intelligence engineering",
"Machine learning"
] |
61,374,397 | https://en.wikipedia.org/wiki/UserLAnd%20Technologies | UserLAnd Technologies is a free and open-source compatibility layer mobile app that allows Linux distributions, computer programs, computer games and numerical computing programs to run on mobile devices without requiring a root account. UserLAnd also provides a program library of popular free and open-source Linux-based programs to which additional programs and different versions of programs can be added.
The name "UserLAnd" is a reference to the concept of userland in modern computer operating systems.
Overview
Unlike other Linux compatibility layer mobile apps, UserLAnd does not require a root account. UserLAnd's ability to function without root directories, also known as "rooting," avoids "bricking" or the non-functionality of the mobile device while the Linux program is in use, which in addition to making the mobile device non-functional may void the device's warranty. Furthermore, the requirement of programs other than UserLAnd to "root" your mobile device has proven a formidable challenge for inexperienced Linux users. A prior application, GNURoot Debian, attempted to similarly run Linux programs on mobile devices, but it has ceased to be maintained and, therefore, is no longer operational.
UserLAnd allows those with a mobile device to run Linux programs, many of which aren't available as mobile apps. Even for those Linux applications, e.g. Firefox, which have mobile versions available, people often find that their user experience with these mobile versions pales in comparison with their desktop. UserLAnd allows its users to recreate that desktop experience on their mobile device.
UserLAnd currently only operates on Android mobile devices. UserLAnd is available for download on Google Play and F-Droid.
Operation
To use UserLAnd, one must first download – typically from F-Droid or the Google Play Store – the application and then install it. Once installed, a user selects an app to open. When a program is selected, the user is prompted to enter login information and select a connection type. Following this, the user gains access to their selected program.
Program library
UserLAnd is pre-loaded with the distributions Alpine, Arch, Debian, Kali, and Ubuntu; the web browser Firefox; the desktop environments LXDE and Xfce; the deployment environments Git and IDLE; the text-based games Colossal Cave Adventure and Zork; the numerical computing programs gnuplot, GNU Octave and R; the office suite LibreOffice; and the graphics editors GIMP and Inkscape. Further Linux programs and different versions of programs may be added to this program library.
Reception
A review on Slant.co listed UserLAnd's "Pro's": support for VNC X sessions, no "rooting" required, easy setup, and that it's free and open-source; and "Con's": its lack of support for Lollipop and the difficulty of use for non-technical users. On the contrary, OS Journal found that the lack of a need to "root" your mobile device made using UserLAnd considerably easier than Linux compatibility layer applications, a position shared with SlashGear's review of UserLAnd. OS Journal went on to state that with UserLAnd one could do "almost anything" and "you’re (only) limited by your insanity" with respect to what you can do with the application. Linux Journal stated that "UserLAnd offers a quick and easy way to run an entire Linux distribution, or even just a Linux application or game, from your pocket." SlashGear stated that UserLAnd is "absolutely super simple to use and requires little to no technical knowledge to get off the ground running."
See also
OS virtualization and emulation on Android
References
2018 software
Android emulation software
Compatibility layers
Computing platforms
Cross-platform software
Free software programmed in Java (programming language)
Free system software
Linux APIs
Linux emulation software
Wine (software) | UserLAnd Technologies | [
"Technology"
] | 796 | [
"Computing platforms"
] |
61,374,561 | https://en.wikipedia.org/wiki/NGC%203001 | NGC 3001 is a magnitude 11.83 spiral galaxy in the constellation Antlia, discovered on 30 March 1835 by John Herschel. It has a recessional velocity of per second, and is located around 115 million light years away. NGC 3001 has an apparent size of 4.3 by 3.1 arcminutes and is about 145 thousand light years across.
One supernova has been observed in NGC 3001: SN2010hg (typeIa, mag. 15) was discovered by Berto Monard on 1 September 2010.
See also
List of NGC objects (3001–4000)
References
External links
Astronomical objects discovered in 1835
Discoveries by John Herschel
Galaxies discovered in 1835
3001
Barred spiral galaxies
Antlia
028027
UGCA objects
434-038 | NGC 3001 | [
"Astronomy"
] | 161 | [
"Antlia",
"Constellations"
] |
61,375,018 | https://en.wikipedia.org/wiki/Teegarden%27s%20Star%20c | Teegarden's Star c (also known as Teegarden c) is an exoplanet found orbiting in the habitable zone of Teegarden's Star, an M-type red dwarf star 12.5 light years away from the Solar System. It orbits in the conservative habitable zone around its star. Along with Teegarden's Star b, it is among the closest known potentially habitable exoplanets. It was discovered in June 2019.
Characteristics
Teegarden's Star c has an orbital period of 11.4 days. The minimum mass of the planet is one Earth mass, and its radius is probably Earth-like, suggesting an Earth-like composition, with an iron core and rocky crust. Teegarden's Star c could potentially have an ocean of water on its surface, or ice because of temperatures.
Habitability
Teegarden c orbits in the conservative habitable zone. The equilibrium temperature for the planet is −47 °C., but if the planet has a thick atmosphere, its surface could be much warmer. Earth's equilibrium temperature is −18 °C, but our atmosphere maintains temperatures well above that.
One positive factor for habitability is its star. Most red dwarfs emit strong flares, which can strip the atmosphere and eliminate habitability. A good example is Kepler-438b, which is likely uninhabitable because its sun is an active star. Another example is Proxima Centauri, the closest star to the sun. Teegarden's Star is inactive and quiet, making the planet possibly habitable. Other quiet red dwarfs with potentially habitable exoplanets are Ross 128 and Luyten's Star.
Host star
Teegarden's Star is an ultra-cool red dwarf at around 9 percent the mass of the Sun with a temperature of around 2,900 Kelvin (2,623 °C or 4,760 F). The inherent low temperatures of such objects explain why it was not discovered earlier, since it has an apparent magnitude of only 15.1 (and an absolute magnitude of 17.22). Like most red and brown dwarfs it emits most of its energy in the infrared spectrum. It is older than the Sun, with an age of 8 billion years.
It was discovered in 2003. Astronomers have long thought it was quite likely that many undiscovered dwarf stars exist within 20 light-years of Earth, because stellar-population surveys show the count of known nearby dwarf stars to be lower than otherwise expected and these stars are dim and easily overlooked. Teegarden's team thought that these dim stars might be found by data mining some of the huge optical sky survey data sets taken by various programs for other purposes in previous years. They reexamined the NEAT asteroid tracking data set and found this star. The star was then located on photographic plates from the Palomar Sky Survey taken in 1951. This discovery is significant as the team did not have direct access to any telescopes and did not include professional astronomers at the time of the discovery.
The parallax was initially measured as 0.43 ± 0.13 arcseconds. This would have placed its distance at only 7.50 light-years, making Teegarden's Star only the third star system in order of distance from the Sun, ranking between Barnard's Star and Wolf 359. However, even at that time the anomalous low luminosity (the absolute magnitude would have been 18.5) and high uncertainty in the parallax suggested that it was in fact somewhat farther away, still one of the Sun's nearest neighbors but not nearly as high in the ranking in order of distance. A more accurate parallax measurement of 0.2593 arcseconds was made by George Gatewood in 2009, yielding the now accepted distance of 12.578 light-years.
References
Exoplanets discovered in 2019
Aries (constellation)
Exoplanets detected by radial velocity
Near-Earth-sized exoplanets in the habitable zone | Teegarden's Star c | [
"Astronomy"
] | 830 | [
"Aries (constellation)",
"Constellations"
] |
61,376,224 | https://en.wikipedia.org/wiki/C30H42O7 | {{DISPLAYTITLE:C30H42O7}}
The molecular formula C30H42O7 (molar mass: 514.65 g/mol, exact mass: 514.2931 u) may refer to:
Angustifodilactone
Stigmatellin
Molecular formulas | C30H42O7 | [
"Physics",
"Chemistry"
] | 65 | [
"Molecules",
"Set index articles on molecular formulas",
"Isomerism",
"Molecular formulas",
"Matter"
] |
61,376,244 | https://en.wikipedia.org/wiki/C23H26O7 | {{DISPLAYTITLE:C23H26O7}}
The molecular formula C23H26O7 (molar mass : 414.454 g/mol) may refer to:
Grayanic acid, a depsidone
Neokadsuranin, a lignan | C23H26O7 | [
"Chemistry"
] | 63 | [
"Isomerism",
"Set index articles on molecular formulas"
] |
61,376,283 | https://en.wikipedia.org/wiki/Copper%28II%29%20glycinate | Copper(II) glycinate (IUPAC suggested name: bis(glycinato)copper(II)) refers to the coordination complex of copper(II) with two equivalents of glycinate, with the formula [Cu(glycinate)2(H2O)x] where x = 1 (monohydrate) or 0 (anhydrous form). The complex was first reported in 1841, and its chemistry has been revisited many times, particularly in relation to the isomerisation reaction between the cis and trans forms which was first reported in 1890.
All forms are blue solids, with varying degrees of water solubility. A practical application of the compound is as a source of dietary copper in animal feeds.
Synthesis
Bis(glycinato)copper(II) is typically prepared from the reaction of copper(II) acetate in aqueous ethanol with glycine:
Cu(OAc)2 + 2 H2NCH2COOH + x H2O → [Cu(H2NCH2COO)2(H2O)x] + 2 AcOH, x = 0 or 1
The reaction proceeds through a non-redox dissociative substitution mechanism and usually affords the cis isomer.
Structure
Like most amino acid complexes, the glycinate forms a 5-membered chelate ring, with the glycinato ligand serving as a bidentate (κ2Ο,Ν) species. The chelating ligands assume a square planar configuration around the copper atom as is common for tetracoordinate d9 complexes, calculated to be much lower in energy than the alternative tetrahedral arrangement.
Cis and trans isomerism
The unsymmetric nature of the ligand and square planar coordination thereof gives rise to two possible geometric isomers: a cis and a trans form.
Multiple ways of differentiating the geometric isomers exist, an easily accessible one being IR spectroscopy with the characteristic number of C–N, C–O, and CuII–N identifying the ligand configuration. Crystal appearance may also be of some value for isomer indication, though the ultimate diagnostic technique is X-ray crystallography.
All forms of the complex have been characterized crystallographically, the most commonly isolated one being the cis monohydrate (x = 1).
Isomerisation of the cis to the trans form occurs at high temperatures via a ring-twisting mechanism.
References
Coordination chemistry
Copper complexes
Glycinates
Metal-amino acid complexes | Copper(II) glycinate | [
"Chemistry"
] | 523 | [
"Coordination chemistry",
"Metal-amino acid complexes"
] |
61,377,527 | https://en.wikipedia.org/wiki/Life%20%28video%20games%29 | In video games, a life is a play-turn that a player character has, defined as the period between start and end of play. Lives refer to a finite number of tries before the game ends with a game over. Sometimes the euphemisms chance, try, rest and continue are used, particularly in all-ages games, to avoid the morbid insinuation of losing one's "life". Generally, if the player loses all their health, they lose a life. Losing all lives usually grants the player character "game over", forcing them to either restart or stop playing.
The number of lives a player is granted varies per game type. A finite number of lives became a common feature in arcade games and action games during the 1980s, and mechanics such as checkpoints and power-ups made the managing of lives a more strategic experience for players over time. Lives give novice players more chances to learn the mechanics of a video game, while allowing more advanced players to take more risks.
History
Lives may have originated from the pinball mechanic of having a limited number of balls. A finite number of lives (usually three) became a common feature in arcade games. The number of lives usually displayed on the screen (in arcade games, the character that is being played, is also counted as a "life"). Much like in pinball games, the player's goal was usually to score as many points as possible with their limited number of lives. Taito's classic arcade video game Space Invaders (1978) is usually credited with introducing multiple lives to video games. Lives were important in these games because the desire to avoid the finality of the player character's death compelled players to insert more quarters, making the maximum amount of profit.
Later, refinements of health, defense and other attributes, as well as power-ups, made managing the player character's life a more strategic experience and made lost health less of the handicap it was in early arcade games. Lives and game over screens became thought of as outmoded concepts and holdovers from arcade games that were unnecessary when players had already paid for the game. They also discouraged the player from playing the game fairly, with players in games such as Doom resorting to save scumming in order to preserve their lives rather than start from an in-game checkpoint with their lives depleted, and getting a game over can often cause players to permanently abandon a game instead of making another attempt at the level. Therefore, most modern games have completely abandoned the concept of player lives, instead simply restarting the player from the nearest checkpoint when they die, allowing them to undo or rewind their progress until such time as they are safe, as in Prince of Persia: The Sands of Time, or making saving the player from death contingent on successfully executing a QTE, as in Batman: Arkham Asylum.
Usage
It is common in action games for the player to have multiple lives and chances to earn more in-game. This way, a player can recover from making a disastrous mistake. Role-playing games and adventure games usually grant only one, but allow player-characters to reload a saved game.
Lives set up the situation where dying is not necessarily the end of the game, allowing the player to take risks they might not take otherwise, or experiment with different strategies to find one that works. Multiple lives also allow novice players a chance to learn a game's mechanics before the game is over. Another reason to implement lives is that the ability to earn extra lives provide an additional reward incentive for the player.
Many older video games feature cheat codes that allow you to gain extra lives without earning them throughout gameplay. One example is Contra, which added the option to input the Konami code to get 30 extra lives.
In modern times, some free-to-play games, such as the Candy Crush Saga trilogy, capitalize on the multiple life system to create an opportunity to earn more microtransactions. In such games, a life is lost when the player fails a level, but once all lives are lost, the player is prevented from continuing the game for a temporary amount of time, instead of receiving a game over that would entail total failure or require a new beginning, as lives will re-generate automatically after a number of minutes or hours. Players can either wait for lives, attempt alternate activities to recover lives (such as asking for friends online to donate lives), or purchase items that can fully replenish lives or grant unlimited lives for a limited time to continue playing immediately. This system works like an "energy" meter for other free-to-play games, however, lives do not deplete when a level is successfully completed, unlike energy.
Extra lives
An extra life or a 1-up is a video game item that increments the player character's number of lives. Because there are no universal game rules, the form 1-ups take varies from game to game, but are often rare and difficult items to acquire. The use of the term "1-up" to designate an extra life first appeared in Super Mario Bros., where a 1-Up could be obtained in several ways, including grabbing a green "1-Up Mushroom", collecting 100 coins, using a Koopa shell to kill 8 or more consecutive enemies, and jumping on 8 or more consecutive enemies without touching the ground. The term quickly caught on, seeing use in both home and arcade video games.
A number of games included an exploitable design flaw called a "1-up loop", in which it is possible to consistently acquire two or more 1-ups between a certain checkpoint and the following checkpoint. The player can thus acquire two 1-ups, make the character die, and restart from the first checkpoint with a net gain of one life; this procedure can then be repeated for as many lives as the player desires.
References
Video game terminology | Life (video games) | [
"Technology"
] | 1,200 | [
"Computing terminology",
"Video game terminology"
] |
59,999,226 | https://en.wikipedia.org/wiki/Seth%20G.%20Atwood | Seth Glanville Atwood (June 2, 1917 – February 21, 2010) was an American industrialist, community leader, and horological collector. He was the chairman and president of Atwood Vacuum Machine Company, one of the world's largest manufacturers of automobile body hardware, and a long-time leader of the Atwood family's business which involved in manufacturing, banking and hotel industries, with over 2,500 employees. In addition, Atwood was a director of the Illinois Manufacturers' Association, and had served in the Illinois Chamber of Commerce and the Graduate School of Business at the University of Chicago.
In 1971, Seth G. Atwood founded the Time Museum at the Clock Tower Resort in Rockford, Illinois, which later became one of the leading horological museums in the world with nearly 1,500 pieces of horological collection, including atomic clocks. The museum's notable collection included ancient Chinese sundials and water clocks, early pendulum clocks, a quarter-repeater by Thomas Tompion, Breguet Sympathique Clocks, and the Patek Philippe Henry Graves Supercomplication which currently holds the title of the most expensive watch ever sold at auction, fetching 24 million US dollars (23,237,000 CHF) in Geneva on November 11, 2014. However, the museum was shut down in 1999 and its collection was sent to auctions over the years.
Early life
Seth G. Atwood was born in Rockford, Illinois on June 2, 1917. He attended Carleton College, and graduated from Stanford University with a B.A. degree in 1938. He later studied at the University of Wisconsin for a year, and obtained an M.B.A. from Harvard University in 1940. From 1942-1946, he served as an officer in the United States Navy, achieving the rank of lieutenant commander.
Seth G. Atwood later returned to Rockford and joined in the Atwood Vacuum Machine Company, which was founded by his father, Seth B. Atwood, and his uncle, James T. Atwood in 1909 specializing in manufacturing vacuum cleaners.
Family business
By 1920, the Atwood Vacuum Machine Company had already shifted its focus from manufacturing vacuum cleaners to door silencers for cars. Eventually, the company began to manufacture a complete line of automobile body hardware. Seth G. Atwood became the president of the Atwood Vacuum Machine Company in 1953 when his father became chairman of the board.
In 1967, Seth G. Atwood became the chairman of the company, and under his leadership the company became the world's "largest independent manufacturer of internal auto body hardware" in 1968. In 1970, the company re-organized and established the Automotive and Contract Division and the Mobile Products Division, employing over 2,500 employees with five plants in Canada and the United States. In 1971, the annual sale of the company reached around US$50 million. In 1985, Atwood Vacuum Machine was sold to Anderson Industries in Rockford, Illinois; the annual sale of the company was US$138 million at the time of this acquisition.
Seth G. Atwood also managed other businesses of his family involving banking, venture capital, hotels and real estate properties.
Timepiece collection
Time Museum
In 1971, Seth G. Atwood founded the Time Museum at the Clock Tower Resort in Rockford, Illinois. The resort was originally built by the Atwood's family in 1968. In 1980s, the museum became one of the leading horological museums in the world, with nearly 1,500 pieces of horological collection, including atomic clocks. The museum's notable collection included ancient Chinese sundials and water clocks by Su Song, early pendulum clocks, a quarter-repeater by Thomas Tompion, an astronomical and world time clock by Christian Gebhard, the Harrison wooden regulator clock, the Richard Glynn mechanical equinoctial standing Ring-Dial, and so on. In 1990s, the museum attracted over 50,000 visitors each year.
However, the museum was shut down in March 1999 when United Realty Corp., a company owned by Atwood family interests, sold the Clock Tower Resort to Regency Hotel Management. As a result, the majority of the museum's collection went to the Museum of Science and Industry in Chicago, and was on display from January 2001 to February 2004. In 2004, a campaign to raise US$35 million to buy the collection for Time Museum failed, and the collection was broken up with its timepieces sent to auctions.
Over the years, hundreds of items from the museum's original collection went up for sale in Sotheby's auctions, and several pieces became the world's most expensive watches and clocks ever auctioned. These included the Patek Philippe Henry Graves Supercomplication and the Breguet Sympathique Clock No.128 & 5009 (Duc d'Orléans Breguet Sympathique, owned by Ferdinand Philippe, Duke of Orléans), which was originally restored by English watchmaker George Daniels at the request of Seth G. Atwood. The Patek Philippe pocket watch currently holds the title of the most expensive watch ever sold at auction, fetching US$24 million US dollars (CHF 23,237,000) in Sotheby's Geneva auction on November 11, 2014. The Breguet Sympathique Clock, on the other hand, currently ranks as one of the most expensive clocks ever sold at auction, fetching US$6.80 million in Sotheby's New York auction on December 4, 2012.
Coaxial escapement
During the quartz crisis in 1970s, Seth G. Atwood commissioned a mechanical timepiece from English watchmaker George Daniels to fundamentally improve the performance of mechanical watches. As a result, Daniels invented the revolutionary coaxial escapement in 1974 and patented it in 1980. The Atwood watch for Seth G. Atwood was completed in 1976.
The coaxial escapement was later used in the watches of watch manufacturers such as Omega SA.
See also
Patek Philippe Henry Graves Supercomplication
Coaxial escapement
References
Further reading
Masterpieces from the Time Museum. Volume I - III. Sotheby's. New York, 1999, 2002, 2004.
Masterpieces from the Time Museum. Volume IV. Sotheby's. New York, 2004.
External links
Time Museum
1917 births
2010 deaths
Carleton College alumni
Stanford University alumni
University of Wisconsin–Madison alumni
Harvard Business School alumni
People from Rockford, Illinois
United States Navy officers
Horology
Military personnel from Illinois | Seth G. Atwood | [
"Physics"
] | 1,334 | [
"Spacetime",
"Horology",
"Physical quantities",
"Time"
] |
60,000,338 | https://en.wikipedia.org/wiki/Tripod%20packing | In combinatorics, tripod packing is a problem of finding many disjoint tripods in a three-dimensional grid, where a tripod is an infinite polycube, the union of the grid cubes along three positive axis-aligned rays with a shared apex.
Several problems of tiling and packing tripods and related shapes were formulated in 1967 by Sherman K. Stein. Stein originally called the tripods of this problem "semicrosses", and they were also called Stein corners by Solomon W. Golomb. A collection of disjoint tripods can be represented compactly as a monotonic matrix, a square matrix whose nonzero entries increase along each row and column and whose equal nonzero entries are placed in a monotonic sequence of cells, and the problem can also be formulated in terms of finding sets of triples satisfying a compatibility condition called "2-comparability", or of finding compatible sets of triangles in a convex polygon.
The best lower bound known for the number of tripods that can have their apexes packed into an grid is , and the best upper bound is , both expressed in big Omega notation.
Equivalent problems
The coordinates of the apexes of a solution to the tripod problem form a 2-comparable sets of triples, where two triples are defined as being 2-comparable if there are either at least two coordinates where one triple is smaller than the other, or at least two coordinates where one triple is larger than the other. This condition ensures that the tripods defined from these triples do not have intersecting rays.
Another equivalent two-dimensional version of the question asks how many cells of an array of square cells (indexed from to ) can be filled in by the numbers from to in such a way that the non-empty cells of each row and each column of the array form strictly increasing sequences of numbers, and the positions holding each value form a monotonic chain within the array. An array with these properties is called a monotonic matrix. A collection of disjoint tripods with apexes can be transformed into a monotonic matrix by placing the number in array cell and vice versa.
The problem is also equivalent to finding as many triangles as possible among the vertices of a convex polygon, such that no two triangles that share a vertex have nested angles at that vertex. This triangle-counting problem was posed by Peter Braß and its equivalence to tripod packing was observed by Aronov et al.
Lower bounds
It is straightforward to find a solution to the tripod packing problem with tripods. For instance, for , the triples
are 2-comparable.
After several earlier improvements to this naïve bound, Gowers and Long found solutions to the tripod problem of cardinality .
Upper bounds
From any solution to the tripod packing problem, one can derive a balanced tripartite graph whose vertices are three copies of the numbers from to (one for each of the three coordinates) with a triangle of edges connecting the three vertices corresponding to the coordinates of the apex of each tripod. There are no other triangles in these graphs (they are locally linear graphs) because any other triangle would lead to a violation of 2-comparability. Therefore, by the known upper bounds to the Ruzsa–Szemerédi problem (one version of which is to find the maximum density of edges in a balanced tripartite locally linear graph), the maximum number of disjoint tripods that can be packed in an grid is , and more precisely . Although Tiskin writes that "tighter analysis of the parameters" can produce a bound that is less than quadratic by a polylogarithmic factor, he does not supply details and his proof that the number is uses only the same techniques that are known for the Ruzsa–Szemerédi problem, so this stronger claim appears to be a mistake.
An argument of Dean Hickerson shows that, because tripods cannot pack space with constant density, the same is true for analogous problems in higher dimensions.
Small instances
For small instances of the tripod problem, the exact solution is known. The numbers of tripods that can be packed into an cube, for , are:
For instance, the figure shows the 11 tripods that can be packed into a cube.
The number of distinct monotonic matrices of order , for is
References
Packing problems
Unsolved problems in geometry | Tripod packing | [
"Mathematics"
] | 899 | [
"Geometry problems",
"Unsolved problems in mathematics",
"Packing problems",
"Unsolved problems in geometry",
"Mathematical problems"
] |
60,000,341 | https://en.wikipedia.org/wiki/Elgin%20Bryce%20Holt | Elgin Bryce Holt (September 4, 1873 – October 6, 1945) was an American geologist, mine owner and engineer, amateur scientist, anthropologist and entrepreneur who reorganized and managed the Cerro de Plata Mining Company in Magdalena, Sonora, Mexico.
Biography
Holt was born in Harrison, Arkansas, the sixth of Lydia Elizabeth (née Ryan) and "Judge" Isham Right Holt's eight children. In 1879, the family moved to a homestead raising cattle along the San Francisco river near Alma, New Mexico. In 1892, the family moved to Las Cruces, New Mexico, allowing the four youngest children to attend the New Mexico Agricultural College. Very successful in mining silver in Mexico, he was known as the "Silver King of Sonora". A member of the American Institute of Mining Engineers and the American Association of Engineers, Holt died in Los Angeles, California and is buried in Forest Lawn Cemetery.
Education
In 1897, Holt was a member of the fourth graduating class of the New Mexico College of Agriculture and Mechanic Arts (now New Mexico State University) having completed the Mining Engineering course. He earned degrees in Geology and Mineralogy. His senior thesis was entitled "The Potassium Cyanide Method of the Determination of Copper".
During his senior year Holt was manager of the college football team and editor-in-chief of the New Mexico Collegian in 1897, the college student newspaper.
Early career
In 1903, Holt and a former classmate W. C. Mossman, left for the 1904 World's Fair in St. Louis, Missouri, to join Zach Mulhall's Congress of Rough Riders and Ropers in the show's "broncho riding act".
Holt began his career renting his father's cattle business, working the family herd with his brother Isham for six years. During that time, Holt completed a post-graduate course in assaying.
Holt's older brother Ernest had a number of mining interests in Sonora, Mexico but was killed in 1900 by a revolver that was said to have fallen from his cot and exploded. Holt sold his cattle and traveled to Sonora, Mexico in 1902 to investigate his brother's mining holdings, which had passed to the Yaqui Gold Company.
After serving as Deputy Sheriff of Cochise County, Arizona in 1903 and 1904, Holt traveled to Santa Ana, Sonora, Mexico in June, 1905.
Mining career
In 1909 Holt and his brother Walter formed the Holt Bros. Mining Engineers company in Magdalena. They also operated an assay office in the same location, allowing them to hear about developments in the mining regions of Sonora.
The brothers prospected for themselves. They made a rich strike of silver at the Compania mine west of Noria Station. The three inch vein of ore was said to be 30% silver.
They also managed mining operations at a number of area mines, including the Sierra Prieta copper mine in Magdalena. In 1909 Holt also served as superintendent and general manager of the Cabrillo Mining company, located 30 miles west of Estacion Llano in Sonora, Mexico. Holt had "discovered and taken charge" of the property in 1907. He ran a tunnel under the "antigua patio process" mine that had played out and discovered chloride silver ore that ran as high as 600 ounces per ton. The property had suffered from a lack of water necessary to mine. Holt sank a 50' well shaft, providing all necessary water for the project.
In 1911, Holt incorporated the Arizona-Sonora Mines Company in Nogales, Arizona to manage a high quality gold strike at the Juan Cabral mining property near Tucabe, Magdalena. Holt's listed address was Magdalena, Sonora, Mexico.
Silver mining success
The Holt brothers met James Campbell Besley, a mine broker from nearby Hermosillo. In 1909 Besley had sold the Cerro de Plata mine, located in Sonora, Mexico, 25 miles southwest of Nogales to a group of Kentucky investors. After two years of disappointing results, the investors had asked Besley to find a purchaser for the mine. Besley brokered a deal with the Holt brothers who purchased the 150 acre mine. Holt said he started the mine with an "absurdly small cash capital of $ 200", adding "we have made the mine literally pay its own way".
In July 1912, Holt made a deal with Roy & Titcomb, Inc. of Nogales, Arizona to build a mill and cyanide plant for treatment of silver ore from the Cerro de Plata mine. Acting as general manager of the mine, Holt claimed "five hundred thousand dollars of silver is in plain sight at the Cerro de Plata mine".
The mill was started November 5, 1912. Mine development and ore shipments continued until thirty one lots of high grade ore had been shipped, mostly in railcar loads, aggregating more than 1400 tons and averaging 117 ounces of silver to the ton. 26,000 ounces of fine silver in the form of bars and precipitates were shipped to the Selby Reduction & Refining Works, near San Francisco, California during the first five weeks' production. In one section the silver content of the ore was assayed as high as 150 ounces to the ton.
Holt was soon shipping 25,000 ounces of silver a month, then worth $ .61 per ounce for a total of $ 15,250 ( - adjusted for current inflation) per month. The success of Holt's operation resulted in his expanding the mine's processing capabilities, erecting a larger 100-ton mill and cyanide plant.
In 1913, Holt and his brother Walter reorganized the US Cerro de Plata Mining Company, combining it with the Mexican corporation Cerro de Plata Mining Company S.A.. James Campbell Besley, Roy & Titcomb, Inc. and Francis J. Hobson were named initial stockholders of the new corporation.
Mexican revolutionaries stopped Holt on March 10, 1913, while he was transporting silver bullion from the mine to Nogales, Arizona. Traveling in an automobile under heavy guard, Holt was held up by 250 men. Holt and his party "were relieved of all arms and ammunition but otherwise unmolested, as the leader stated they did not want the bullion, only arms".
A November 1913 newspaper article reported a 200% increase in net production receipts at the Cerro de Plata mine, growing from $7,000 realized in the month of October to an estimated monthly profit of $14,000 () from the production of "the little old dinky plant now in use". The article mentioned plans of doubling the production capacity at the mine.
In 1914, the Cerro de Plata mine was reported to be a "silver bonanza" and "one of the coming big bonanzas of Mexico". Holt was president and manager of the mine and his brother Walter was secretary and treasurer.
Holt displayed 16,000 ounces of silver bullion taken from the Cerro de Plata mine in December 1914. The bullion, estimated at the time being worth over $8,000 () was displayed in the window of the International drug store in Nogales, Arizona along with a silver "Savior on the cross" cast from the same refined silver ore. The display was taken to Phoenix, Arizona a week later, shown at the American Mining Congress. Holt was the delegate from Santa Cruz county, Arizona.
By 1915, Holt was referred to as the "Silver King of Sonora". Holt claimed "during these (past) three years we have had a total production of nearly 700,000 ounces of silver" and "we already have 1,000,000 ounces of silver blocked out above the 300 foot level and will begin further sinking soon".
In 1916, Holt was personally supervising the extraction of lead and silver ore from the Wandering Jew mine group in Santa Cruz County, Arizona. The ore was hauled by wagon to Patagonia, Arizona and shipped to El Paso, Texas for processing.
Bandits, said to be Yaqui insurgents burned the Cerro de Plata Mining Company store in October 1916. They destroyed the company assaying office and shot at the company caretaker, killing his mule. Holt estimated the loss at $1,000. The ore tailing mill and cyanide plant were not damaged.
It was reported Holt still owned silver mines in the Sonora area in 1920.
Later career
Mine engineering consultant
In 1921, Holt was developing mining properties in San Luis Gonzaga, Sinaloa, Mexico. Holt was a director of the Mexican Metals Recovery Co., incorporated in Arizona in 1922. The company was headquartered in El Paso, Texas. In 1937 Holt held an option to develop the Mowry mine, located in Santa Cruz County, Arizona.
Arizona State mining engineer
Holt worked as a district mine engineer for the Arizona State Department of Mineral Resources. His initial assignment was to compile and codify rules and regulations regarding mining on the various federal and state classifications of land in Arizona. His reports on state mining activity were often printed as news stories in prominent newspapers.
Holt was one of two of the state Department of Mineral Resources's four field engineers that lost funding in 1945 by a veto cast by Governor Sidney Preston Osborn during budget cuts.
Amateur scientist
Anthropology
Holt's article "Cliff Dwellers of the Mexican Sierra Madre" was published in the November, 1926 Bulletin of the Pan American Union. The article explored the greater part of the Sierra Madre from the Rio Aros, in the State of Chihuahua, to southwestern Durango, bordering the State of Nayarit.
Entomology
Holt reported two new types of ichneumon fly in 1895 and 1896. In September 1895, Holt found a female example of a new type of ichneumon fly at Ardmore, South Dakota which the US Department of Agriculture named Paniscus clypeatus. Deemed a new species, the insect was described as "distinct in the entire lack of scutellar carinae and its strongly transversely elevated clypeus".
Holt also reported another new type of ichneumon fly in the spring of 1896, a female example taken at Las Cruces, New Mexico. Named at the time Paniscus pulcher by the US Department of Agriculture, the insect was deemed a new species and described as being "very distinct in the entire lack of scutellar carinae and the highly contrasting color of the thorax".
Holt collected an example of Gorytes hamatus, a sand fly at Las Cruces, New Mexico in 1896. His collected insect is listed in Contributions to the Entomology of New Mexico: Volume 1.
Holt also provided the United States National Museum an example of a Dasymutilla Pseudopappas mutillidae wasp, taken in the Mesilla Valley of New Mexico in 1896.
Paleontology
Holt donated fossil and mineral specimens he had found in the Arizona and Mexican desert. Among them were "exceptionally choice samples of cassiterite (mineral tin oxide)" he found in Durango, Mexico and donated to the University of Nebraska Uni Museum in 1926.
He donated fossil crocodile and phytosaur specimens to the American Museum of Natural History in 1936. He also donated Temnospondyli fossils found at St. Johns, Apache County, Arizona to the American Museum of Natural History.
Death and burial
Apparently despondent due to a long bout of ill health, Holt attempted suicide on October 5, 1945, by repeatedly hitting himself in the head with a hammer. He was then a resident of Los Angeles, California. First treated at Georgia Street Receiving Hospital, Holt was later transferred to Los Angeles General Hospital where he was diagnosed with a skull fracture. He died the next day, October 6, 1945. His funeral rites were held on October 10, 1945, in Los Angeles.
Holt is buried in Forest Lawn Memorial Park in Glendale, Los Angeles County, California.
References
1873 births
1945 deaths
People from Harrison, Arkansas
American geologists
Silver mining
Mining engineering
Amateur paleontologists
19th-century American engineers
20th-century American engineers
New Mexico State University alumni
Suicides in California | Elgin Bryce Holt | [
"Engineering"
] | 2,450 | [
"Mining engineering"
] |
60,000,347 | https://en.wikipedia.org/wiki/Solvent%20bonding | Solvent bonding (also called solvent welding) is not a method of adhesive bonding (the final result does not rely on the adhesion of another substance [adhesive] and its cohesion between two substrates), but rather a method of fusing two thermoplastic plastics. Application of a solvent to a thermoplastic material softens the polymer, and with applied pressure this results in polymer chain interdiffusion at the bonding junction. When the solvent evaporates, this leaves a fully consolidated bond-line. An advantage to solvent bonding versus other polymer joining methods is that bonding generally occurs below the glass transition temperature of the polymer.
Solvent bonding differs from adhesive bonding, because the solvent does not become a permanent addition to the joined substrate. Solvent bonding differs from other plastic welding processes in that heating energy is generated by the chemical reaction between the solvent and thermoplastic, and cooling occurs during evaporation of the solvent.
Solvent bonding can be performed using a liquid or gaseous solvent. Liquid solvents are simpler and generally have lower manufacturing costs but are sensitive to surface imperfections that may cause inconsistent or unpredictable bonding. Some solvents available may not react with the thermoplastic at room temperature but will react at an elevated temperature resulting in a bond. Curing times are highly variable.
Applying solvent methods
Four common application methods are:
Brush-on method. The solvent is brushed onto the surfaces to be joined, with subsequent pressure being applied until full strength of the bond is formed after the solvent has fully evaporated.
Capillary action method. Commonly used with acrylic components, a consistent narrow gap between the parts allows the solvent to flow along the surfaces to be joined, via capillary action. Application is generally performed using a hypodermic needle to allow for precise application in the joint gap.
Dip-dab method. A surface to be joined is dipped into a vat of solvent, with the solvent depth being a controlled variable, for a set amount of time. Once the part has been removed from the vat, a screen mesh or foam pad is used to remove the excess solvent before the bonding surfaces are paired.
Solvent dispenser method. A dispenser is used to precisely control the amount of solvent applied on each surface.
Thermoplastic and solvent compatibility
The proper solvent choice for bonding is dependent on the solubility of the chosen thermoplastic in the solvent and the processing temperature. The table below provides a selection of solvents commonly used for bonding specific thermoplastics. Mutual solubility between a polymer and a solvent may be determined using the Hildebrand solubility parameter. Polymers will generally be more soluble in solvents with similar solubility parameters to their own in a given state (liquid or solid). The solubility parameters of polymers are not greatly affected by changes in temperature, however the solubility parameters for liquids are affected by temperature. Increasing the temperature lowers the free energy of mixing, promoting dissolution at the interface and interdiffusion bonding.
Testing solvent-bonded joints
There are three main mechanical testing methods for plastic bonding joints: tensile testing, tensile shear test, and peel test. Tensile testing using a butt joint configuration is not very conducive to polymers, particularly thin sheets, due to the challenges of mounting to the load frame. An epoxy may be used for mounting, but can lead to failure in the epoxy/polymer interface instead of in the bonded joint. The most common method for testing solvent bonds is the tensile shear test using a lap joint configuration. Specimens are tested in shear to failure at a given overlap cross section via tensile loading. This testing method is particularly conducive to thin specimens due to distortion mitigation distortion in the test specimens due to the loading mechanism. Guidance for tensile shear testing may be found in ASTM D1002-05.
Industrial applications
There are several industries that utilize solvent bonding for their applications. A few of these include microchip manufacturing, medical, and potable and sanitary plumbing systems.
See also
Plastic welding
Ultrasonic welding
References
Bonding
Adhesives
Plastics | Solvent bonding | [
"Physics"
] | 849 | [
"Amorphous solids",
"Unsolved problems in physics",
"Plastics"
] |
60,002,578 | https://en.wikipedia.org/wiki/Korean%20Astronomical%20Society | The Korean Astronomical Society () is a non-profit learned society in South Korea that aims to supporting astronomical scholarship, technological development, education, and the spread of astronomical knowledge. It operates the Journal of the Korean Astronomical Society.
The KAS was founded on 21 March 1965, and presently has over 700 members. It holds meetings in spring and autumn of each year. The KAS is a member organisation of the International Astronomical Union, which it joined in 1973, and hosted the IAU Asia-Pacific Regional Meeting in 1996 and 2014. It also co-hosted the International Astronomy Olympiad in 2012.
References
Astronomy societies
1965 establishments in Korea
Scientific organizations established in 1965
Scientific organizations based in South Korea | Korean Astronomical Society | [
"Astronomy"
] | 139 | [
"Astronomy societies",
"Astronomy organizations"
] |
60,007,722 | https://en.wikipedia.org/wiki/Edriss%20Titi | Edriss Saleh Titi (, ; born 22 March 1957 in Acre, Israel) is an Arab-Israeli mathematician. He is Professor of Nonlinear Mathematical Science at the University of Cambridge. He also holds the Arthur Owen Professorship of Mathematics at Texas A&M University, and serves as Professor of Computer Science and Applied Mathematics at the Weizmann Institute of Science and Professor Emeritus at the University of California, Irvine.
Selected works
References
External links
1957 births
Applied mathematicians
Arab citizens of Israel
Fellows of the Society for Industrial and Applied Mathematics
Indiana University Bloomington alumni
Israeli expatriates in the United States
Israeli mathematicians
People from Acre, Israel
Technion – Israel Institute of Technology alumni
Texas A&M University faculty
University of California, Irvine faculty
Academic staff of Weizmann Institute of Science
Living people
Cambridge mathematicians | Edriss Titi | [
"Mathematics"
] | 162 | [
"Applied mathematics",
"Applied mathematicians"
] |
60,008,192 | https://en.wikipedia.org/wiki/Ehud%20de%20Shalit | Ehud de Shalit (; born 16 March 1955) is an Israeli number theorist and professor at the Hebrew University of Jerusalem.
Biography
Ehud de Shalit was born in Rehovot. His father was Amos de-Shalit. He completed his B.Sc. at the Hebrew University in 1975, and his Ph.D. at Princeton University in 1984 under the supervision of Andrew Wiles.
Academic career
De Shalit joined the faculty of Hebrew University in 1987 and was promoted to full professor in 2001. He is an editor for the Israel Journal of Mathematics.
Published works
References
External links
1955 births
Living people
Hebrew University of Jerusalem alumni
Academic staff of the Hebrew University of Jerusalem
Israeli Jews
Israeli mathematicians
Number theorists
People from Rehovot
Princeton University alumni | Ehud de Shalit | [
"Mathematics"
] | 152 | [
"Number theorists",
"Number theory"
] |
60,008,412 | https://en.wikipedia.org/wiki/Greenberg%27s%20conjectures | Greenberg's conjecture is either of two conjectures in algebraic number theory proposed by Ralph Greenberg. Both are still unsolved as of 2021.
Invariants conjecture
The first conjecture was proposed in 1976 and concerns Iwasawa invariants. This conjecture is related to Vandiver's conjecture, Leopoldt's conjecture, Birch–Tate conjecture, all of which are also unsolved.
The conjecture, also referred to as Greenberg's invariants conjecture, firstly appeared in Greenberg's Princeton University thesis of 1971 and originally stated that, assuming that is a totally real number field and that is the cyclotomic -extension, , i.e. the power of dividing the class number of is bounded as . Note that if Leopoldt's conjecture holds for and , the only -extension of is the cyclotomic one (since it is totally real).
In 1976, Greenberg expanded the conjecture by providing more examples for it and slightly reformulated it as follows: given that is a finite extension of and that is a fixed prime, with consideration of subfields of cyclotomic extensions of , one can define a tower of number fields
such that is a cyclic extension of of degree . If is totally real, is the power of dividing the class number of bounded as ? Now, if is an arbitrary number field, then there exist integers , and such that the power of dividing the class number of is , where for all sufficiently large . The integers , , depend only on and . Then, we ask: is for totally real?
Simply speaking, the conjecture asks whether we have for any totally real number field and any prime number , or the conjecture can also be reformulated as asking whether both invariants λ and μ associated to the cyclotomic -extension of a totally real number field vanish.
In 2001, Greenberg generalized the conjecture (thus making it known as Greenberg's pseudo-null conjecture or, sometimes, as Greenberg's generalized conjecture):
Supposing that is a totally real number field and that is a prime, let denote the compositum of all -extensions of . (Recall that if Leopoldt's conjecture holds for and , then .) Let denote the pro- Hilbert class field of and let , regarded as a module over the ring . Then is a pseudo-null -module.
A possible reformulation: Let be the compositum of all the -extensions of and let , then is a pseudo-null -module.
Another related conjecture (also unsolved as of yet) exists:
We have for any number field and any prime number .
This related conjecture was justified by Bruce Ferrero and Larry Washington, both of whom proved (see: Ferrero–Washington theorem) that for any abelian extension of the rational number field and any prime number .
p-rationality conjecture
Another conjecture, which can be referred to as Greenberg's conjecture, was proposed by Greenberg in 2016, and is known as Greenberg's -rationality conjecture. It states that for any odd prime and for any , there exists a -rational field such that . This conjecture is related to the Inverse Galois problem.
Further reading
R. Greenberg, On some questions concerning the lwasawa invariants, Princeton University thesis (1971)
R. Greenberg, "On the lwasawa invariants of totally real number fields", American Journal of Mathematics, issue 98 (1976), pp. 263–284
R. Greenberg, "Iwasawa Theory — Past and Present", Advanced Studies in Pure Mathematics, issue 30 (2001), pp. 335–385
R. Greenberg, "Galois representations with open image", Annales mathématiques du Québec, volume 40, number 1 (2016), pp. 83–119
B. Ferrero and L. C. Washington, "The Iwasawa Invariant Vanishes for Abelian Number Fields", Annals of Mathematics (Second Series), volume 109, number 2 (May, 1979), pp. 377–395
Algebraic number theory
Conjectures
Unsolved problems in number theory | Greenberg's conjectures | [
"Mathematics"
] | 829 | [
"Unsolved problems in mathematics",
"Unsolved problems in number theory",
"Conjectures",
"Algebraic number theory",
"Mathematical problems",
"Number theory"
] |
60,009,183 | https://en.wikipedia.org/wiki/Alex%20Ma | Wan-Chun Alex Ma (; born 1978) is a Taiwanese software engineer.
Ma was born in 1978. Ma became interested in visual effects at a young age, influenced by the Star Wars film series and Wing Commander III: Heart of the Tiger, a video game released in 1994. He completed his bachelor's, master's, and doctoral degrees at National Taiwan University. With the help of the Graduate Student Study Abroad Program of Taiwan's National Science Council. Ma went to the University of Southern California in 2005, completing his studies under Paul Debevec at the Institute for Creative Technologies. Since obtaining his doctorate, Ma has worked for Activision and Google.
In 2019, Debevec's research team, including Ma, were jointly awarded an Academy Award for Technical Achievement for the development of the
Polarized Spherical Gradient Illumination, a facial appearance capture and modeling technology used in several films.
References
External links
Software engineers
21st-century engineers
Google employees
Taiwanese expatriates in the United States
Activision employees
National Taiwan University alumni
Taiwanese engineers
Academy Award for Technical Achievement winners
1978 births
Living people | Alex Ma | [
"Engineering"
] | 223 | [
"Software engineering",
"Software engineers"
] |
60,009,254 | https://en.wikipedia.org/wiki/Ilan%20Amit | Ilan Amit (; – ) was an Israeli mathematician, spiritual philosopher, and defence consultant. He worked as a strategist and senior advisor to Israel's defence establishment, including the Mossad.
Biography
Ilan Kroch (later Amit) was born in Haifa. His father, a mathematics teacher, was deputy principal of the Hebrew Reali School and a founder of the Hebrew Scouts Movement in Israel. Amit studied at the Reali School, where he was a student of Josef Schächter. In 1960, Amit was one of the founders of the moshav shitufi Yodfat, where he became a proponent of the teachings of mystic George Gurdjieff.
After completing his undergraduate studies in mathematics at the Technion, Amit worked at Mekorot, soon becoming head of the company's operations research department. He completed his Ph.D. in mathematics from the Technion in 1967, under the supervision of Elisha Netanyahu.
Amit joined the military research department at Rafael in the late 1970s, not long after which he became blind as the result of illness. In the late 1980s Amit joined a team in Mossad's intelligence division that aimed to engage in intelligence estimates and formulate recommendations in the area of policy and strategy.
In 2009, he became a member of the Prime Minister's National Security Council. He died at the age of 78 following a stroke, survived by his wife and four children.
Awards and commemoration
Presence: Ilan Amit's Journey, a film about Amit's life, was released in 2018.
Published works
Amit has translated Kierkegaard into Hebrew and published essays on Emily Dickinson and on therapy of the absurd, along with many classified research papers. His published books include:
External links
References
1935 births
2013 deaths
20th-century Israeli philosophers
Applied mathematicians
Israeli blind people
Israeli mathematicians
Israeli spiritual teachers
Israeli spiritual writers
People of the Mossad
Israeli political consultants
Technion – Israel Institute of Technology alumni
Burials at Kiryat Shaul Cemetery
Scientists with disabilities | Ilan Amit | [
"Mathematics"
] | 422 | [
"Applied mathematics",
"Applied mathematicians"
] |
60,009,563 | https://en.wikipedia.org/wiki/Theodore%20T.%20Munger | Theodore Thornton Munger (March 5, 1830 - January 11, 1910) was an American Congregational clergyman, theologian and writer.
Biography
Born on March 5, 1830, in Bainbridge, New York, Munger graduated from Yale University in 1851 and from Yale Divinity School in 1855. He studied under Horace Bushnell at Yale Divinity School. After graduating in 1855, Munger began preaching in Massachusetts. In 1885, he was appointed pastor of the United Church in New Haven, Connecticut.
Munger was an advocate of theistic evolution. He argued that "evolution not only perfects our conception of the unity of God, but... strengthens the argument from design". However, Munger rejected the concept of survival of the fittest. Munger promoted liberal theology and maintained that revelation was a product of evolution and that there are no a priori scriptural truths.
Munger was an early proponent of animal rights. He authored the book The Rights of Dumb Animals, published by the Connecticut Humane Society in 1896.
Munger's other publications include: On the Threshold (1880); The Freedom of Faith (1883); Lamps and Paths (1883); The Appeal to Life (1887); Horace Bushnell (1899) and Character Through Inspiration.
Munger received the degree of Doctor of Divinity from Illinois College (1883), Harvard University (1904) and Yale University (1908).
He died at his home in New Haven on January 11, 1910.
Famous quotation
Munger is well known for a famous quotation which is usually misattributed to others. In his 1884 book On the Threshold he wrote the following:
This is extracted from a larger quote in the book. This shortened version, with the word "persistence" replacing the word "purpose" is often misattributed to President Calvin Coolidge in 1929. But the true source was Munger.
Selected publications
The Freedom of Faith (1883)
On the Threshold (1884)
Lamps and Paths (1885)
The Rights of Dumb Animals (1896)
The Appeal to Life (1899)
Essays for the Day (1904)
References
Further reading
Benjamin Wisner Bacon. (1913). Theodore Thornton Munger New England Minister. Yale University Press.
External links
Theodore Thornton Munger papers (MS 362). Manuscripts and Archives, Yale University Library.
1830 births
1910 deaths
American animal rights scholars
American Christian theologians
American Congregationalists
Congregationalist writers
Doctors of Divinity
Theistic evolutionists
Writers from New York (state)
Yale Divinity School alumni
Yale University alumni | Theodore T. Munger | [
"Biology"
] | 509 | [
"Non-Darwinian evolution",
"Theistic evolutionists",
"Biology theories"
] |
60,010,424 | https://en.wikipedia.org/wiki/Electric%20bacteria | Electric bacteria are forms of bacteria that directly consume and excrete electrons at different energy potentials without requiring the metabolization of any sugars or other nutrients. This form of life appears to be especially adapted to low-oxygen environments. Most life forms require an oxygen environment in which to release the excess of electrons which are produced in metabolizing sugars. In a low oxygen environment, this pathway for releasing electrons is not available. Instead, electric bacteria "breathe" metals instead of oxygen, which effectively results in both an intake of and excretion of electrical charges.
Some electric bacteria:
Shewanella, which makes protein nanowires
Geobacter, which makes protein nanowires out of pilin
Methanobacterium palustre
Methanococcus maripaludis
Mycobacterium smegmatis
Modified Escherichia coli (with Geobacter nanowire genes)
A broad collection of 30 bacteria varieties from marine sediments
See also
Electron transport chain
References
Bacteria | Electric bacteria | [
"Biology"
] | 204 | [
"Bacteria stubs",
"Prokaryotes",
"Microorganisms",
"Bacteria"
] |
60,011,618 | https://en.wikipedia.org/wiki/Singing%20Sand%20Dunes%20%28Dunhuang%29 | The Singing Sand Dunes ( Ming Sha Shan) in Dunhuang, China, are the sand dunes that, when the wind blows, give out a singing or drumming sound. They are part of the Kumtag Desert.
The Singing Sand Dunes were originally known as the "Gods' Sand Dunes" (). In the Records of the Grand Historian, Sima Qian described the sound "as if listening to music when the weather is fine." During the Ming Dynasty, they came to be called by the current name.
There are four better-known singing sand dunes in China, that include those of Hami, which are usually said to give the best sound among the four, and those of Dunhuang.
The tourist area at the site offers various facilities and activities such as ATV riding, paragliding, camel rides and sandboarding.
See also
Singing sand
Mogao Caves: nearby
References
Physical phenomena
AAAAA-rated tourist attractions
Dunes of China
Dunhuang
Hami | Singing Sand Dunes (Dunhuang) | [
"Physics"
] | 199 | [
"Physical phenomena"
] |
60,012,784 | https://en.wikipedia.org/wiki/Phytoglobin-NO%20cycle | The phytoglobin-nitric oxide cycle is a metabolic pathway induced in plants under hypoxic conditions which involves nitric oxide (NO) and phytoglobin (Pgb). It provides an alternative type of respiration to mitochondrial electron transport under the conditions of limited oxygen supply. Phytoglobin in hypoxic plants acts as part of a soluble terminal nitric oxide dioxygenase system, yielding nitrate ion from the reaction of oxygenated phytoglobin with NO. Class 1 phytoglobins are induced in plants under hypoxia, bind oxygen very tightly at nanomolar concentrations, and can effectively scavenge NO at oxygen levels far below the saturation of cytochrome c oxidase. In the course of the reaction, phytoglobin is oxidized to metphytoglobin which has to be reduced for continuous operation of the cycle. Nitrate is reduced to nitrite by nitrate reductase, while NO is mainly formed due to anaerobic reduction of nitrite which may take place in mitochondria by complex III and complex IV in the absence of oxygen, in the side reaction of nitrate reductase, or by electron transport proteins on the plasma membrane. The overall reaction sequence of the cycle consumes NADH and can contribute to the maintenance of ATP level in highly hypoxic conditions.
References
Metabolism | Phytoglobin-NO cycle | [
"Chemistry",
"Biology"
] | 295 | [
"Biochemistry",
"Metabolism",
"Cellular processes"
] |
60,013,689 | https://en.wikipedia.org/wiki/Stanley%20sequence | In mathematics, a Stanley sequence is an integer sequence generated by a greedy algorithm that chooses the sequence members to avoid arithmetic progressions. If is a finite set of non-negative integers on which no three elements form an arithmetic progression (that is, a Salem–Spencer set), then the Stanley sequence generated from starts from the elements of , in sorted order, and then repeatedly chooses each successive element of the sequence to be a number that is larger than the already-chosen numbers and does not form any three-term arithmetic progression with them.
These sequences are named after Richard P. Stanley.
Binary–ternary sequence
The Stanley sequence starting from the empty set consists of those numbers whose ternary representations have only the digits 0 and 1. That is, when written in ternary, they look like binary numbers. These numbers are
0, 1, 3, 4, 9, 10, 12, 13, 27, 28, 30, 31, 36, 37, 39, 40, ...
By their construction as a Stanley sequence, this sequence is the lexicographically first arithmetic-progression-free sequence. Its elements are the sums of distinct powers of three, the numbers such that the th central binomial coefficient is 1 mod 3, and the numbers whose balanced ternary representation is the same as their ternary representation.
The construction of this sequence from the ternary numbers is analogous to the construction of the Moser–de Bruijn sequence, the sequence of numbers whose base-4 representations have only the digits 0 and 1, and the construction of the Cantor set as the subset of real numbers in the interval whose ternary representations use only the digits 0 and 2. More generally, they are a 2-regular sequence, one of a class of integer sequences defined by a linear recurrence relation with multiplier 2.
This sequence includes three powers of two: 1, 4, and 256 = 35 + 32 + 3 + 1. Paul Erdős conjectured that these are the only powers of two that it contains.
Growth rate
Andrew Odlyzko and Richard P. Stanley observed that the number of elements up to some threshold in the binary–ternary sequence, and in other Stanley sequences starting from or , grows proportionally to . For other starting sets the Stanley sequences that they considered appeared to grow more erratically but even more sparsely. For instance, the first irregular case is , which generates the sequence
0, 4, 5, 7, 11, 12, 16, 23, 26, 31, 33, 37, 38, 44, 49, 56, 73, 78, 80, 85, 95, 99, ...
Odlyzko and Stanley conjectured that in such cases the number of elements up to any threshold is . That is, there is a dichotomy in the growth rate of Stanley sequences between the ones with similar growth to the binary–ternary sequence and others with a much smaller growth rate; according to this conjecture, there should be no Stanley sequences with intermediate growth.
Moy proved that Stanley sequences cannot grow significantly more slowly than the conjectured bound for the sequences of slow growth. Every Stanley sequence has elements up to . More precisely Moy showed that, for every such sequence, every , and all sufficiently large , the number of elements is at least .
Later authors improved the constant factor in this bound,
and proved that for Stanley sequences that grow as the constant factor in their growth rates can be any rational number whose denominator is a power of three.
History
A variation of the binary–ternary sequence (with one added to each element)
was considered in 1936 by Paul Erdős and Pál Turán, who observed that it has no three-term arithmetic progression and conjectured (incorrectly) that it was the densest possible sequence with no arithmetic progression.
In unpublished work with Andrew Odlyzko in 1978, Richard P. Stanley experimented with the greedy algorithm to generate progression-free sequences.
The sequences they studied were exactly the Stanley sequences for the initial sets .
Stanley sequences were named, and generalized to other starting sets than , in a paper published in 1999 by Erdős (posthumously) with four other authors.
References
Further reading
Integer sequences | Stanley sequence | [
"Mathematics"
] | 848 | [
"Sequences and series",
"Integer sequences",
"Mathematical structures",
"Recreational mathematics",
"Mathematical objects",
"Combinatorics",
"Numbers",
"Number theory"
] |
60,014,170 | https://en.wikipedia.org/wiki/Artistic%20Foundry%20Battaglia | Artistic Foundry Battaglia (Fonderia Artistica Battaglia) is one of the oldest artistic bronze foundries in the world. It specializes in producing artistic sculptures using the lost-wax casting technique.
It was founded in 1913 by Ercole Battaglia, Giulio Pogliani and Riccardo Frigerio in Milan.
For more than 100 years the Battaglia Foundry have worked with artists, sculptors and designers including Giannino Castiglioni, Alighiero Boetti, Arnaldo Pomodoro, Narciso Cassino, Lucio Fontana, Giuseppe Penone, Kengiro Azuma, and many others.
The Foundry specializes in design and sculpture as well as restoration.
In 2016, the Artistic Foundry Battaglia has established its annual award – Battaglia Foundry Sculpture Prize (BFSP). The aim is to encourage young artists and promote the use of bronze and the lost-wax casting technique in contemporary art.
It was chosen as one of the Artistic Residencies by the Arte Laguna Prize.
Most Notable Works
The Monument to the Fallen in Magenta by Giannino Castiglioni (1925);
The bronze doors of the Milan Cathedral by Giannino Castiglioni (1945);
One of the four equestrian groups for Arlington Memorial Bridge (The Arts of War and The Arts of Peace) in Washington, D.C.;
The 14-meter statue of Madonna della Guardia, by Narciso Cassino (one of the largest bronze castings in existence) (1958);
The door of the Siena Cathedral by Enrico Manfrini (1958);
The replica of the bronze Byzantine horses for the Basilica of San Marco in Venice (1979);
Statue of Pope Paul VI by Floriano Bodini (1986);
Self-Portrait sculpture by Alighiero Boetti (1993);
Sphere within Sphere sculpture for the UN headquarters in New York by Arnaldo Pomodoro (1996).
References
Foundries
Bronze | Artistic Foundry Battaglia | [
"Chemistry"
] | 406 | [
"Foundries",
"Metallurgical facilities"
] |
60,014,820 | https://en.wikipedia.org/wiki/Center%20for%20Life%20Detection | The Center for Life Detection (CLD) is a collaboration among scientists and technologists from NASA’s Ames Research Center and Goddard Spaceflight Center, which formed in 2018 to support the planning and implementation of missions that will seek evidence of life beyond Earth. CLD is supported by NASA’s Planetary Science Division and is one of three core teams in the Network for Life Detection. CLD’s perspectives on life detection science and technology development are summarized in “Groundwork for Life Detection”, a white paper submitted to and cited in the 2023-2032 Planetary Science and Astrobiology Decadal Survey.
Activities
The search for life elsewhere is among the NASA Science Mission Directorate's high-level priorities (Science 2020-2024: A Vision for Scientific Excellence, Priority 1). The Center for Life Detection was founded to support this search by:
conducting research on biosignature “detectability” to help inform target/sample selection and measurement strategies/requirements;
developing tools and engagement activities that enable members of the broader astrobiology community to formulate their knowledge, research, and expertise in a way that facilitates use in mission planning;
supporting the instrument development community in mapping existing and emerging measurement technology to life detection science objectives, in order to establish science traceability and identify technology development needs.
Research
Multiple worlds within and beyond the Solar System are considered potentially habitable by virtue of the presence of liquid water, and mission concepts to seek evidence of life on these worlds are being developed. On Earth, the abundance distribution of life and its products ranges over many orders of magnitude, as a function of multiple environmental and ecological factors. Similar variability can be expected both within and among inhabited worlds beyond Earth, if any exist, and understanding it can inform target selection, observing strategies, and measurement requirements for missions that seek evidence of life. To build this understanding, scientists in CLD conduct research to assess how environmental factors affect “detectability” – the extent to which life, if present, would express itself in characteristic, observable features. This research is responsive to a recommendation in the National Academies Consensus Report on Astrobiology Strategy (NASEM ABS): “Detectability: NASA should support expanding biosignature research to address gaps in understanding biosignature preservation and the breadth of possible false positives and false negative signatures”. The research is conducted with applications to Mars, Ocean Worlds, and Exoplanets.
The Life Detection Forum Project
The astrobiology knowledge that will be required for life detection mission concept development and science definition is diverse, often taking forms that do not map clearly to mission design, and diffuse, in that it is spread across many scientific disciplines and a wide-ranging literature. The Life Detection Forum (LDF) project seeks to develop a ‘living’, community-driven suite of tools to centralize the requisite body of knowledge and organize it in a way that streamlines its use in program planning, mission concept development, and interpretation of findings. Researchers in CLD work actively to engage a diverse range of communities in the use of this tool in order to harness expertise that is not well represented in the traditional sphere of space science.
The LDF is being built as a web-based platform that can be populated and continually updated by a broad user base, in order to track the evolving state of knowledge regarding life detection science and technology. The core module of the system, released in early 2021, is the Life Detection Knowledge Base (LDKB). LDKB is a system for organizing user-provided knowledge about objects, patterns, or processes that might serve as evidence for life according to its bearing on the potential for false positive or false negative results. A technology-oriented counterpart to LDKB, the Measurement Technology Module (MTM) is currently in development. MTM will house user-contributed information regarding current and emerging technologies that could be used to support life detection objectives. When combined, LDKB and MTM will provide a basis for establishing science traceability and identifying technology development needs.
The Life Detection Forum Project is responsive to the NASEM ABS recommendation: “NASA should aid the community in developing a comprehensive framework [...] to guide testing and evaluation of in situ and remote biosignatures.
Workshops
CLD sought extensive community involvement in the development of LDF tools and early stages of LDKB content development, through a series of workshops and hands-on community engagement activities.
Introduction to the Life Detection Forum Project (Summer 2019)
Special session, approx. 130 participants
Introduction to, and feedback on, the LDF concept and a basic working model
Criteria for Life Detection Measurements (Fall 2020)
Two community workshops, 60+ participants
Establish & vet the evaluative organizing basis for LDKB
The Life Detection Knowledge Base (January 2021)
Rollout of LDKB at a community workshop of > 150 participants
LDKB Content Development Groups (Spring-Fall 2021)
CLD-facilitated, community-based user groups (100+ participants, active 6–8 months)
Content provision in 5 theme areas, beta testing of LDKB, build & train user base
Future of the Search for Life (Spring 2022)
2-weeks workshop, 100 participants
Engage scientists and technologists to discuss high-priority approaches to life detection, define measurement requirements, and identify corresponding measurement technology gaps
References
External links
Astrobiology.nasa.gov
https://www.nfold.org/
NASA
Astrobiology
Research institutes in California | Center for Life Detection | [
"Astronomy",
"Biology"
] | 1,104 | [
"Origin of life",
"Speculative evolution",
"Astrobiology",
"Biological hypotheses",
"Astronomical sub-disciplines"
] |
60,016,083 | https://en.wikipedia.org/wiki/Signaturen | Signaturen is a residential high-rise building in Tønsberg city, Norway. The building is situated in Kaldnes on the northernmost part of the island Nøtterøy in Tønsberg municipality. At tall, it is Vestfold county's tallest building.
The building is owned by the Norwegian residential property developer Selvaag Bolig and completed in early 2019, but was opened for new residents already in December 2018. The construction started in 2017.
The residential building has 13 floors and 23 apartments. The top floor can be reached by either stairs or a high-speed Kone traction elevator. The tower has a neo-futuristic architectural style.
References
External links
Signaturen on selvaagbolig.no
Residential skyscrapers
Buildings and structures completed in 2018
Buildings and structures completed in 2019
Residential buildings completed in 2019
Modernist architecture in Norway
Postmodern architecture
High-tech architecture
Neo-futurist architecture | Signaturen | [
"Engineering"
] | 188 | [
"Postmodern architecture",
"Architecture"
] |
63,566,617 | https://en.wikipedia.org/wiki/Projective%20tensor%20product | In functional analysis, an area of mathematics, the projective tensor product of two locally convex topological vector spaces is a natural topological vector space structure on their tensor product. Namely, given locally convex topological vector spaces and , the projective topology, or π-topology, on is the strongest topology which makes a locally convex topological vector space such that the canonical map (from to ) is continuous. When equipped with this topology, is denoted and called the projective tensor product of and .
Definitions
Let and be locally convex topological vector spaces. Their projective tensor product is the unique locally convex topological vector space with underlying vector space having the following universal property:
For any locally convex topological vector space , if is the canonical map from the vector space of bilinear maps to the vector space of linear maps , then the image of the restriction of to the continuous bilinear maps is the space of continuous linear maps .
When the topologies of and are induced by seminorms, the topology of is induced by seminorms constructed from those on and as follows. If is a seminorm on , and is a seminorm on , define their tensor product to be the seminorm on given by
for all in , where is the balanced convex hull of the set . The projective topology on is generated by the collection of such tensor products of the seminorms on and .
When and are normed spaces, this definition applied to the norms on and gives a norm, called the projective norm, on which generates the projective topology.
Properties
Throughout, all spaces are assumed to be locally convex. The symbol denotes the completion of the projective tensor product of and .
If and are both Hausdorff then so is ; if and are Fréchet spaces then is barelled.
For any two continuous linear operators and , their tensor product (as linear maps) is continuous.
In general, the projective tensor product does not respect subspaces (e.g. if is a vector subspace of then the TVS has in general a coarser topology than the subspace topology inherited from ).
If and are complemented subspaces of and respectively, then is a complemented vector subspace of and the projective norm on is equivalent to the projective norm on restricted to the subspace . Furthermore, if and are complemented by projections of norm 1, then is complemented by a projection of norm 1.
Let and be vector subspaces of the Banach spaces and , respectively. Then is a TVS-subspace of if and only if every bounded bilinear form on extends to a continuous bilinear form on with the same norm.
Completion
In general, the space is not complete, even if both and are complete (in fact, if and are both infinite-dimensional Banach spaces then is necessarily complete). However, can always be linearly embedded as a dense vector subspace of some complete locally convex TVS, which is generally denoted by .
The continuous dual space of is the same as that of , namely, the space of continuous bilinear forms .
Grothendieck's representation of elements in the completion
In a Hausdorff locally convex space a sequence in is absolutely convergent if for every continuous seminorm on We write if the sequence of partial sums converges to in
The following fundamental result in the theory of topological tensor products is due to Alexander Grothendieck.
The next theorem shows that it is possible to make the representation of independent of the sequences and
Topology of bi-bounded convergence
Let and denote the families of all bounded subsets of and respectively. Since the continuous dual space of is the space of continuous bilinear forms we can place on the topology of uniform convergence on sets in which is also called the topology of bi-bounded convergence. This topology is coarser than the strong topology on , and in , Alexander Grothendieck was interested in when these two topologies were identical. This is equivalent to the problem: Given a bounded subset do there exist bounded subsets and such that is a subset of the closed convex hull of ?
Grothendieck proved that these topologies are equal when and are both Banach spaces or both are DF-spaces (a class of spaces introduced by Grothendieck). They are also equal when both spaces are Fréchet with one of them being nuclear.
Strong dual and bidual
Let be a locally convex topological vector space and let be its continuous dual space. Alexander Grothendieck characterized the strong dual and bidual for certain situations:
Examples
For a measure space, let be the real Lebesgue space ; let be a real Banach space. Let be the completion of the space of simple functions , modulo the subspace of functions whose pointwise norms, considered as functions , have integral with respect to . Then is isometrically isomorphic to .
See also
Citations
References
Further reading
External links
Nuclear space at ncatlab
Functional analysis
Topological tensor products | Projective tensor product | [
"Mathematics",
"Engineering"
] | 1,003 | [
"Functions and mappings",
"Tensors",
"Functional analysis",
"Mathematical objects",
"Mathematical relations",
"Topological tensor products"
] |
63,566,619 | https://en.wikipedia.org/wiki/Injective%20tensor%20product | In mathematics, the injective tensor product is a particular topological tensor product, a topological vector space (TVS) formed by equipping the tensor product of the underlying vector spaces of two TVSs with a compatible topology. It was introduced by Alexander Grothendieck and used by him to define nuclear spaces. Injective tensor products have applications outside of nuclear spaces: as described below, many constructions of TVSs, and in particular Banach spaces, as spaces of functions or sequences amount to injective tensor products of simpler spaces.
Definition
Let and be locally convex topological vector spaces over , with continuous dual spaces and A subscript as in denotes the weak-* topology. Although written in terms of complex TVSs, results described generally also apply to the real case.
The vector space of continuous bilinear functionals is isomorphic to the (vector space) tensor product , as follows. For each simple tensor in , there is a bilinear map , given by . It can be shown that the map , extended linearly to , is an isomorphism.
Let denote the respective dual spaces with the topology of bounded convergence. If is a locally convex topological vector space, then . The topology of the injective tensor product is the topology induced from a certain topology on , whose basic open sets are constructed as follows. For any equicontinuous subsets and , and any neighborhood in , define
where every set is bounded in which is necessary and sufficient for the collection of all to form a locally convex TVS topology on
This topology is called the -topology or injective topology. In the special case where is the underlying scalar field, is the tensor product as above, and the topological vector space consisting of with the -topology is denoted by , and is not necessarily complete; its completion is the injective tensor product of and and denoted by .
If and are normed spaces then is normable. If and are Banach spaces, then is also. Its norm can be expressed in terms of the (continuous) duals of and . Denoting the unit balls of the dual spaces and by and , the injective norm of an element is defined as
where the supremum is taken over all expressions . Then the completion of under the injective norm is isomorphic as a topological vector space to .
Basic properties
The map is continuous.
Suppose that and are two linear maps between locally convex spaces. If both and are continuous then so is their tensor product . Moreover:
If and are both TVS-embeddings then so is
If (resp. ) is a linear subspace of (resp. ) then is canonically isomorphic to a linear subspace of and is canonically isomorphic to a linear subspace of
There are examples of and such that both and are surjective homomorphisms but is a homomorphism.
If all four spaces are normed then
Relation to projective tensor product
The projective topology or the -topology is the finest locally convex topology on that makes continuous the canonical map defined by sending to the bilinear form When is endowed with this topology then it will be denoted by and called the projective tensor product of and
The injective topology is always coarser than the projective topology, which is in turn coarser than the inductive topology (the finest locally convex TVS topology making separately continuous).
The space is Hausdorff if and only if both and are Hausdorff. If and are normed then for all , where is the projective norm.
The injective and projective topologies both figure in Grothendieck's definition of nuclear spaces.
Duals of injective tensor products
The continuous dual space of is a vector subspace of , denoted by The elements of are called integral forms on , a term justified by the following fact.
The dual of consists of exactly those continuous bilinear forms on for which
for some closed, equicontinuous subsets and of and respectively, and some Radon measure on the compact set with total mass . In the case where are Banach spaces, and can be taken to be the unit balls and .
Furthermore, if is an equicontinuous subset of then the elements can be represented with fixed and running through a norm bounded subset of the space of Radon measures on
Examples
For a Banach space, certain constructions related to in Banach space theory can be realized as injective tensor products. Let be the space of sequences of elements of converging to , equipped with the norm . Let be the space of unconditionally summable sequences in , equipped with the norm
Then and are Banach spaces, and isometrically and (where are the classical sequence spaces). These facts can be generalized to the case where is a locally convex TVS.
If and are compact Hausdorff spaces, then as Banach spaces, where denotes the Banach space of continuous functions on .
Spaces of differentiable functions
Let be an open subset of , let be a complete, Hausdorff, locally convex topological vector space, and let be the space of -times continuously differentiable -valued functions. Then .
The Schwartz spaces can also be generalized to TVSs, as follows: let be the space of all such that for all pairs of polynomials and in variables, is a bounded subset of
Topologize with the topology of uniform convergence over of the functions as and vary over all possible pairs of polynomials in variables. Then,
Notes
References
Further reading
External links
Nuclear space at ncatlab
Functional analysis
Topological tensor products | Injective tensor product | [
"Mathematics",
"Engineering"
] | 1,131 | [
"Functions and mappings",
"Tensors",
"Functional analysis",
"Mathematical objects",
"Mathematical relations",
"Topological tensor products"
] |
63,567,907 | https://en.wikipedia.org/wiki/Cloth%20face%20mask | A cloth face mask is a mask made of common textiles, usually cotton, worn over the mouth and nose. When more effective masks are not available, and when physical distancing is impossible, cloth face masks are recommended by public health agencies for disease "source control" in epidemic situations to protect others from virus laden droplets in infected mask wearers' breath, coughs, and sneezes. Because they are less effective than N95 masks, surgical masks, or physical distancing in protecting the wearer against viruses, they are not considered to be personal protective equipment by public health agencies.
Cloth face masks were routinely used by healthcare workers starting from the late 19th century. They fell out of use in the developed world in favor of disposable surgical masks with an electret (electrically charged) filter material, but cloth masks persisted in developing countries. During the COVID-19 pandemic, their use in developed countries was revived due to shortages, as well as for environmental concerns and practicality. Launderable cloth electret filters were also being developed.
Usage
Prior to the COVID-19 pandemic, reusable cloth face masks were predominantly used by healthcare workers in developing countries and were especially prominent in Asia. Cloth face masks contrast with surgical masks and respirators such as N95 masks, which are made of nonwoven fabric formed through a melt blowing process. In addition, respirators, unlike cloth face masks, are regulated for their effectiveness based upon efficiency of minimum particle size filtered and/or maximum penetrating particle (MPP) size, along with other criteria such as outer splash/spray protection, inner splash/spray absorption, contaminant accumulation and shedding, air flow, and inflammability. Like surgical masks, and unlike respirators, cloth face masks do not provide a seal around the face, and prior to the 2019 COVID-19 outbreak were generally not authorized by institutions for protection from sub-HEPA particle size (less than 0.3 um) Influenza Like Illness (ILI).
In healthcare settings, they are used on sick patients as source control to reduce disease transmission through respiratory droplets, and by healthcare workers when surgical masks and respirators are unavailable. Cloth face masks are only recommended for use by healthcare workers as a last resort if supplies of surgical masks and respirators are exhausted. They are also used by the general public in household and community settings as perceived protection against both infectious diseases and particulate air pollution and to contain the wearer's exhaled virus laden droplets.
Several types of cloth face masks are available commercially, especially in Asia. Homemade masks can also be improvised using bandanas, T-shirts, handkerchiefs, scarves, or towels. But depending on the situation, reusable cloth masks with incorporated filters can block particles nearly as well as medical-grade masks can, as long as they fit securely.
Recommendations
The World Health Organization (WHO) recommends that cloth face masks should be worn in public where social distancing is not possible to help stop the spread of coronavirus. It notes that wearing a cloth face mask is just one of a range of tools that can be used to reduce the risk of transmission. The US Center for Disease Control, along with Johns Hopkins University School of Medicine, The Mayo Clinic, and Cleveland Clinic all concur with this recommendation. The World Health Organization also recommended that those aged over 60 years old or with underlying health risks require more protection and should wear medical masks in areas where there is community transmission.
The World Health Organization recommends using masks with at least three layers of different materials. Two spunbond polypropylene layers are also believed to offer adequate filtration and breathability. When producing cloth face masks, two parameters should be considered: filtration efficiency of the material and breathability.
The filter quality factor known as "Q" is commonly used as an integrated filter quality indicator. It is a function of filtration efficiency and breathability, with higher values indicating better performance. Experts recommend Q-factor of three or higher.
A peer-reviewed summary of the filtration properties of cloth and cloth masks concluded that, pending further research, evidence is strongest for 2 to 4 layers of plain weave cotton or flannel, at least 100 thread count. A plain-language summary of this review is available.
Effectiveness
Cloth face masks can be used for source control to reduce disease transmission arising from the wearer's respiratory droplets, but are not considered personal protective equipment for the wearer as they typically have very low filter efficiency. There are no standards or regulation for self-made cloth face masks.
As of 2015, there had been no randomized clinical trials or guidance on the use of reusable cloth face masks. Most research had been performed in the early 20th century, before disposable surgical masks became prevalent. One 2010 study found that 40–90% of particles in the 20–1000 nm range penetrated a cloth mask and other fabric materials. The performance of cloth face masks varies greatly with the shape, fit, and type of fabric, as well as the fabric fineness and number of layers. As of 2006, no cloth face masks had been cleared by the U.S. Food and Drug Administration for use as surgical masks. A Vietnamese study of healthcare workers compared influenza-like illness outcome among those wearing cloth masks versus medical masks. They concluded that cloth masks were ineffective at preventing transmission in high-risk clinical settings. Although discouraged in clinical settings, cloth masks may still serve a useful role in reducing disease transmission in public settings according to a systematic review.
The primary role of masks worn by the general public is to "stop those who are already infected broadcasting the virus into the air around them". This is of particular importance with the COVID-19 pandemic, as silent transmission seems to be a key feature of its rapid spread. For example, of the people on board the Diamond Princess cruise ship, 634 people were found to be infected—52% had no symptoms at the time of testing, including 18% who never developed symptoms. It is important to note that mask wearers are more likely to engage in other hygiene measures such as hand washing and social distancing. Best practice is to implement multiple prevention techniques to reduce risk, as characterized by the Swiss cheese model.
Compared with bacteria recovery from unmasked volunteers, a mask made of muslin and flannel reduced bacteria recovered on agar sedimentation plates by 99%, total airborne microorganisms by 99%, and bacteria recovered from aerosols (<4 μm) by 88% to 99%. In 1975, 4 medical masks and 1 commercially produced reusable mask made of 4 layers of cotton muslin were compared. Filtration efficiency, assessed by bacterial counts, was 96% to 99% for the medical masks and 99% for the cloth mask; for aerosols (<3.3 μm), it was 72% to 89% and 89%, respectively.
An experiment carried out in 2013 by Public Health England, that country's health-protection agency, found that a commercially made surgical mask filtered 90% of virus particles from the air coughed out by participants, a vacuum cleaner bag filtered out 86%, a tea towel blocked 72% and a cotton t-shirt 51%—though fitting any DIY mask properly and ensuring a good seal around the mouth and nose is crucial. The use of common fabrics in making face masks has been tested. Filter efficiency can be improved with multiple layers, high weave density, and a mix of different types of fabrics. Cotton is the most commonly used material, and filter efficiencies can reach >80% for particles <300 nm with fabric combinations such as cotton-silk, cotton-chiffon, or cotton-flannel. The most protective cloth masks need at least three layers with a hydrophilic inner layer (e.g. cotton) to absorb moisture from the wearer's breathing and hydrophobic outer layers (e.g. polyester). Masks should be cleaned after each use. They can either be laundered or hand-washed in soapy hot water and dried with high heat.
History
In Roman times, Pliny the Elder recommended that miners use animal bladders to protect against inhaling lead oxides. Some followers of Jainism, which originated in India around 500 B.C.E, wear cloth masks to avoid accidentally inhaling insects as part of practicing ahimsa. In the 16th century, Leonardo da Vinci advised the use of a wet woven cloth to protect against toxic agents of chemical warfare. In the early modern period, the plague-doctor costume included a beaked face-mask worn to protect the wearer from infectious "miasma".
Conventional cowboy attire in the American West often included a bandanna, which could protect the face from blown dust and also potentially doubled as a means of obscuring identity.
In 1890 William Stewart Halsted pioneered the use of rubber gloves and surgical face masks, although some European surgeons such as Paul Berger and Jan Mikulicz-Radecki had worn cotton gloves and masks earlier. These masks became commonplace after World War I and the Spanish flu epidemic of 1918. Cloth face masks were promoted by Wu Lien-teh in the 1910–11 Manchurian pneumonic plague outbreak, although Western medics doubted their efficacy in preventing the spread of disease.
Cloth masks were largely supplanted by modern surgical masks made of nonwoven fabric in the 1960s, although their use continued in developing countries. They were used in Asia during the 2002–2004 SARS outbreak, and in West Africa during the 2013–2016 Ebola epidemic. Compared with bacteria recovery from unmasked volunteers, a mask made of muslin and flannel reduced bacteria recovered on agar sedimentation plates by 99%, total airborne microorganisms by 99%, and bacteria recovered from aerosols (<4 μm) by 88% to 99%. In 1975, 4 medical masks and 1 commercially produced reusable mask made of 4 layers of cotton muslin were compared. Filtration efficiency, assessed by bacterial counts, was 96% to 99% for the medical masks and 99% for the cloth mask; for aerosols (<3.3 μm), it was 72% to 89% and 89%, respectively.
COVID-19 pandemic
During the COVID-19 pandemic, most countries recommended the use of cloth masks to reduce the spread of the virus.
On June 5, 2020, WHO changed its advice on face masks, recommending that the general public should wear fabric masks where widespread COVID-19 transmission exists and physical distancing is not possible (for example, "on public transport, in shops or in other confined or crowded environments").
See also
N95 - a mask designed to stop the spread of tuberculosis
Nose filter
References
External links
CDC Mask Guidance – Help Slow the Spread
NPR: 3 Tips for Safer Face Masks (video on YouTube)
Mayo Clinic expert on nonmedical mask use to prevent public transmission (video on YouTube)
Cloth masks
History of medicine
Medical masks
Air filters
Infection-control measures
2020s fashion | Cloth face mask | [
"Chemistry"
] | 2,298 | [
"Air filters",
"Filters"
] |
63,567,957 | https://en.wikipedia.org/wiki/Living%20medicine | A living medicine is a type of biologic that consists of a living organism that is used to treat a disease. This usually takes the form of a cell (animal, bacterial, or fungal) or a virus that has been genetically engineered to possess therapeutic properties that is injected into a patient. Perhaps the oldest use of a living medicine is the use of leeches for bloodletting, though living medicines have advanced tremendously since that time.
Examples of living medicines include cellular therapeutics (including immunotherapeutics), phage therapeutics, and bacterial therapeutics, a subset of the latter being probiotics.
Development of living medicines
Development of living medicines is an extremely active research area in the fields of synthetic biology and microbiology. Currently, there is a large focus on: 1) identifying microbes that naturally produce therapeutic effects (for example, probiotic bacteria), and 2) genetically programming organisms to produce therapeutic effects.
Applications
Cancer therapy
There is tremendous interest in using bacteria as a therapy to treat tumors. In particular, tumor-homing bacteria that thrive in hypoxic environments are particularly attractive for this purpose, as they will tend to migrate to, invade (through the leaky vasculature in the tumor microenvironment) and colonize tumors. This property tends to increase their residence time in the tumor, giving them longer to exert their therapeutic effects, in contrast to other bacteria that would be quickly cleared by the immune system.
References
Bacteria and humans
Biological engineering
Biotechnology
Biotechnology products
Biopharmaceuticals
Pharmaceutical industry
Life sciences industry
Specialty drugs
Pharmacy | Living medicine | [
"Chemistry",
"Engineering",
"Biology"
] | 325 | [
"Pharmacology",
"Biological engineering",
"Specialty drugs",
"Life sciences industry",
"Biotechnology products",
"Pharmacy",
"Pharmaceutical industry",
"Biotechnology",
"Bacteria",
"nan",
"Bacteria and humans",
"Biopharmaceuticals"
] |
63,568,142 | https://en.wikipedia.org/wiki/Bacterial%20therapy | Bacterial therapy is the therapeutic use of bacteria to treat diseases. Bacterial therapeutics are living medicines, and may be wild type bacteria (often in the form of probiotics) or bacteria that have been genetically engineered to possess therapeutic properties that is injected into a patient.
Other examples of living medicines include cellular therapeutics (including immunotherapeutics), activators of anti-tumor immunity, or synergizing with existing tools and approaches. and phage therapeutics, or as delivery vehicles for treatment, diagnosis, or imaging, complementing or synergizing with existing tools and approaches.
Development
Development of bacterial therapeutics is an extremely active research area in the fields of synthetic biology and microbiology. Currently, there is a large focus on: 1) identifying bacteria that naturally produce therapeutic effects (for example, probiotic bacteria), and 2) genetically programming bacteria to produce therapeutic effects.
Design
Optimal strain design often requires a balance between strain suitability for function in the target microenvironment and concerns for feasibility of manufacturing and clinical development.
The development workflow should incorporate technologies for optimizing strain potency, as well as predictive in vitro and in vivo assays, as well quantitative pharmacology models, to maximize translational potential for patient populations.
Applications
Cancer therapy
There is tremendous interest in using bacteria as a therapy to treat tumors. In particular, tumor-homing bacteria that thrive in hypoxic environments are particularly attractive for this purpose, as they will tend to migrate to, invade (through the leaky vasculature in the tumor microenvironment) and colonize tumors. This property tends to increase their residence time in the tumor, giving them longer to exert their therapeutic effects, in contrast to other bacteria that would be quickly cleared by the immune system. In addition, colonized bacteria can lyze the tumor, activate anti-tumor immune response, can be engineered as a delivery vehicle for anti-cancer therapeutics and may have the potential as contrast agents for cancer imaging. Microbial-based cancer therapy may offer an opportunity to address the issue of global cancer therapy disparity and introduce more suitable cancer immunotherapy approach to low- and middle-income countries.
Mechanism
After systemic administration, bacteria localize to the tumor microenvironment. The interactions between bacteria, cancer cells, and the surrounding microenvironment cause various alterations in tumor-infiltrating immune cells, cytokines, and chemokines, which further facilitate tumor regression. ① Bacterial toxins from S. Typhimurium, Listeria, and Clostridium can kill tumor cells directly by inducing apoptosis or autophagy. Toxins delivered via Salmonella can upregulate Connexin 43 (Cx43), leading to bacteria-induced gap junctions between the tumor and dendritic cells (DCs), which allow cross-presentation of tumor antigens to the DCs. ② Upon exposure to tumor antigens and interaction with bacterial components, DCs secrete robust amounts of the proinflammatory cytokine IL-1β, which subsequently activates CD8+ T cells. ③ The antitumor response of the activated CD8+ T cells is further enhanced by bacterial flagellin (a protein subunit of the bacterial flagellum) via TLR5 activation. The perforin and granzyme proteins secreted by activated CD8+ T cells efficiently kill tumor cells in primary and metastatic tumors. ④ Flagellin and TLR5 signaling also decreases the abundance of CD4+ CD25+ regulatory T (Treg) cells, which subsequently improves the antitumor response of the activated CD8+ T cells. ⑤ S. Typhimurium flagellin stimulates NK cells to produce interferon-γ (IFN-γ), an important cytokine for both innate and adaptive immunity. ⑥ Listeria-infected MDSCs shift into an immune-stimulating phenotype characterized by increased IL-12 production, which further enhances the CD8+ T and NK cell responses. ⑦ Both S. Typhimurium and Clostridium infection can stimulate significant neutrophil accumulation. Elevated secretion of TNF-α and TNF-related apoptosis-inducing ligand (TRAIL) by neutrophils enhances the immune response and kills tumor cells by inducing apoptosis. ⑧ The macrophage inflammasome is activated through contact with bacterial components (LPS and flagellin) and Salmonella-damaged cancer cells, leading to elevated secretion of IL-1β and TNF-α into the tumor microenvironment. NK cell: natural killer cell. Treg cell: regulatory T cell. MDSCs: myeloid-derived suppressor cells. P2X7 receptor: purinoceptor 7-extracellular ATP receptor. LPS: lipopolysaccharide
Clostridioides difficile infection therapy
Alterations in the gut microbiome are thought to be associated with C. difficile infection and recurrence. Therapies include probiotics and fecal microbiota transplantation.
Microbiome engineering
There is considerable interest in using bacterial therapeutics to alter human gastrointestinal microbiota to help diseases like small intestinal bacterial overgrowth, gut dysbiosis associated with the pathogenesis of food allergy, and other forms of dysbiosis.
See also
Living medicine
References
Bacteria and humans
Biological engineering
Biotechnology
Biotechnology products
Biopharmaceuticals
Pharmaceutical industry
Life sciences industry
Specialty drugs
Pharmacy | Bacterial therapy | [
"Chemistry",
"Engineering",
"Biology"
] | 1,163 | [
"Pharmacology",
"Biological engineering",
"Specialty drugs",
"Life sciences industry",
"Biotechnology products",
"Pharmacy",
"Pharmaceutical industry",
"Biotechnology",
"Bacteria",
"nan",
"Bacteria and humans",
"Biopharmaceuticals"
] |
63,568,558 | https://en.wikipedia.org/wiki/Plectocomia%20pierreana | Plectocomia pierreana is a species of liana in the Arecaceae, or palm tree, family. It is a spiny climber, with either a single stem or a cluster of stems up to 35 m in length, stems are 1 to 9 cm in diameter. Its spines are up to 2 cm long.
The palm is native to Thailand, Cambodia, Laos, Vietnam and China.
It occurs in the dense forests and stunted forest of Cambodia, particularly in Kampot and Kampong Chhnang provinces.
Growing in Bokor National Park, in Kampot, it occurs in the stunted forest community, called forêt sempervirente basse de montagne by Pauline Dy Phon, that occurs around 920 m, though the plant possibly occurs up to 1014 m.
It has also been reported as very common in Phnom Kulen National Park, Siem Reap province, Cambodia, growing particularly in the Evergreen Forest community.
In Vietnam it has been identified in Lào Cai, Tuyên Quang and Vĩnh Phúc provinces.
Present in Yunnan, Guangxi and Guangdong provinces in China, it is found in lowland to montane rainforests below 1200 m, growing rapidly and abundantly.
In Cambodia, the plant is known as phdau traèhs, phdau ach moën or phdao sno, and the stalk/trunk is used to make ropes and in basketwork. Producing large rattan, between 20 and 40 mm in diameter, out of which furniture, baskets, fish-traps, e.t.c are made, wai teleuk (local name in Lao language, wai means rattan) is commercially exploited in Laos.
References
Biota of Cambodia
Flora of Cambodia
Flora of China
Flora of Indo-China
Flora of Vietnam
pierreana
Trees of Cambodia
Trees of China
Trees of Vietnam | Plectocomia pierreana | [
"Biology"
] | 379 | [
"Biota by country",
"Biota of Cambodia"
] |
63,568,758 | https://en.wikipedia.org/wiki/Late-acting%20self-incompatibility | Late-acting self-incompatibility (LSI) is the occurrence of self-incompatibility (SI) in flowering plants where pollen tubes from self-pollen successfully reach the ovary, but ovules fail to develop. Mechanisms that might cause late-acting self-incompatibility have yet to be elucidated. One hypothesis is that the occurrence of LSI is caused by early-acting inbreeding depression where the expression of genetic load causes self-fertilized embryos to abort.
Advantages and disadvantages of LSI
The proposed advantages of LSI compared to normal SI mechanisms is that LSI would allow the maternal parent to evaluate the paternal genetic material and allow ovule development depending on the vigor of developing embryos or amount of resources available.
On the other hand, plants with LSI may face a disadvantage from seed discounting, which results in a reduction in fecundity. When pollen tubes reach the ovule, they are no longer available to be fertilized by outcrossed pollen, meaning LSI still uses up ovules for potential outcrossing while other SI methods do not.
Evidence supporting LSI
Since LSI reactions are said to occur in the ovary and ovules, it is more difficult to researchers to determine where LSI reactions may occur to assess possible LSI mechanisms. Conventional SI reactions are much easier to observe, because they occur in the style or on the stigma. However, research has provided some evidence for the existence of late-acting self-incompatibility. Species noted to possibly have LSI form phylogenetic groupings in a similar fashion to how conventional SI is shared in other phylogenetic groups, suggesting that LSI may be derived from a common ancestor. A study by Lippow and Wyatt reported that species that have LSI create offspring that can be split into different groupings of compatibility and incompatibility based on Mendelian inheritance, which is something that can be demonstrated with plants that have typical SI mechanisms. It is also reported that some plants lack conventional SI mechanisms, yet ovules failed to develop at all, which is unexpected if the mechanism were to be due to lethal alleles.
Evidence against LSI and alternative explanations
Studies have reported evidence against LSI and have proposed alternative explanation. For example, some species that are expected to have LSI display abortion at various stages of seed development, indicating that the abortion was due to selective embryo abortion caused by early-acting inbreeding depression. Another explanation for LSI is that it is the occurrence of gametophytic self-incompatibility, but self-pollen tubes are slowed to the point where they do not achieve fertilization prior to ovule abortion.
References
Plant reproduction | Late-acting self-incompatibility | [
"Biology"
] | 563 | [
"Behavior",
"Plant reproduction",
"Plants",
"Reproduction"
] |
63,569,293 | https://en.wikipedia.org/wiki/Richard%20Kingsford%20%28ecologist%29 | Richard Kingsford is an environmental/biological expert and river ecologist. Much of his work has been undertaken with the Murray-Darling Basin wetlands and rivers covering approximately 70 percent of the Australian continent. He is the director of the Centre for Ecosystem Science at the University of New South Wales School of Biological, Earth and Environmental Sciences, a member of the Australian Government’s Environmental Flows Scientific Committee. He has received the following awards:
2001: Eureka Award for his research on ecological values of rivers and impact of Australia’s water resource aridity;
2007: Hoffman medal for his contribution to global wetland science;
2008: Eureka Award for Promoting Understanding of Science;
2015: Eureka Award (as a member of the IUCN Red List of Ecosystems team) for Environmental Research resulting in the establishment of a universal standard for assessing ecosystem risks;
2019: Society for Conservation Biology’s Distinguished Service Award also relating to contributions to freshwater/ecosystem conservation;
2020: Fellow of the Royal Society of New South Wales.
Kingsford presented "A Meander Down a River or Two: How Water Defines Our Continent and Its Future" for the second Eric Rolls Memorial Lecture in 2012.
In 2019 the Australian Regional Council (ARC) appointed Kingsford as chief investigator in a team to develop a new international standard for the appraisal and reporting of the status of the most crucial wetlands worldwide.
Publications
His most cited publication, Kingsford, Richard Tennant. "Ecological impacts of dams, water diversions and river management on floodplain wetlands in Australia." Australian Ecology 25.2 (2000): 109-127.m has been cited 985 times, according to Google Scholar.
References
Australian ecologists
Environmental scientists
Living people
Year of birth missing (living people)
Fellows of the Royal Society of New South Wales | Richard Kingsford (ecologist) | [
"Environmental_science"
] | 356 | [
"Environmental scientists",
"Australian environmental scientists"
] |
63,570,144 | https://en.wikipedia.org/wiki/Social%20stigma%20associated%20with%20COVID-19 | Due to the ongoing COVID-19 pandemic, people can sometimes be labelled, stereotyped, discriminated against, treated separately, or experience loss of status because of real or perceived links with the disease. As a result of such treatment, those who have or are perceived to have the disease, as well as their caregivers, family, friends, and communities, may be subjected to social stigma.
Due to the social stigma, individuals and groups have been subjected to racism, xenophobia, and hate crimes, including physical attacks. The groups shown to be most vulnerable to this social stigma are Asian people, in particular those of East Asian and Southeast Asian descent or appearance, people who have traveled abroad, people who have recently completed quarantine, healthcare professionals, and emergency service workers.
It has also been shown that wearing or refusing to wear a mask has become subject to stigma. The existence of such social stigma and their negative impacts have been documented by many organizations, including UNICEF, the WHO, and the CDC.
Reasons for and impact of social stigma
The level of stigma towards those affected with COVID-19 stems from multiple factors. Due to the novelty of the virus, there are many unknowns surrounding transmission and a possible cure. Many people cannot access tests and drug development for treatment is still in progress. Meanwhile, there is widespread misinformation regarding the disease, under which various online groups and activists have spread conspiracy theories and unproven claims, including: that the virus was created in a laboratory; the virus was "planned"; and that the virus was caused by 5G networks, among other theories.
In this cultural context, the disease itself is an unknown—and, according to many international health experts, people feel fearful when confronted with the unknown. In such circumstances, they may deal with this fear by assigning blame to the "other," which may include groups of people, governments, or institutions. This environment can fuel harmful stereotypes. As a result, social cohesion is undermined, and there may be increased social isolation of impacted groups. Due to this social isolation, people may be less likely to seek out medical help or services, take necessary precautions, or seek out social services, due to fear of discrimination. This can contribute to a situation in which the virus is more likely to spread, leading to severe health problems and difficulties in controlling disease outbreak. People could also be subjected to physical violence and hate crimes.
Addressing social stigma
Stigma related to COVID-19 can be countered by building trust in reliable health services and showing empathy to affected individuals.
Health organizations such as UNICEF and the Mayo Clinic recommend that media use people-first language when discussing the pandemic to avoid unnecessary negative tone. For instance, the official name 'COVID-19' or the colloquial term 'coronavirus' is preferred instead of 'Chinese virus', 'Wuhan virus' or 'Asian virus', which attach ethnicities or locations to the disease. UNICEF and the WHO also recommend the usage of 'people who have COVID-19' instead of 'COVID-19 cases' or 'COVID-19 victims'. Phrasing that implies malice is discouraged, so that 'acquiring' or 'contracting' COVID-19 is used rather than 'transmitting' or 'spreading' COVID-19. Advocates stated these recommendations reduce the negative connotations and subconscious dehumanization that could result from emphasizing disease status.
To counter misinformation, UNICEF advises public figures to share facts based on latest scientific evidence as opposed to unsubstantiated rumors. Social media users are encouraged to share sympathetic stories of recovery and treatment while maintaining cultural sensitivity. These recommendations are intended to diminish the panic that might result from fear-mongering and exaggerated terms such as 'plague' or 'apocalypse'. Public figures are encouraged to use simple language and correct misconceptions while acknowledging any individual feeling or reactions to the pandemic. According to UNICEF and the WHO, accurate information can reduce stigma caused by fear of the unknown.
References
Social stigma
Discrimination
Social impact of the COVID-19 pandemic | Social stigma associated with COVID-19 | [
"Biology"
] | 847 | [
"Behavior",
"Aggression",
"Discrimination"
] |
63,570,220 | https://en.wikipedia.org/wiki/Integrable%20algorithm | Integrable algorithms are numerical algorithms that rely on basic ideas from the mathematical theory of integrable systems.
Background
The theory of integrable systems has advanced with the connection between numerical analysis. For example, the discovery of solitons came from the numerical experiments to the KdV equation by Norman Zabusky and Martin David Kruskal. Today, various relations between numerical analysis and integrable systems have been found (Toda lattice and numerical linear algebra, discrete soliton equations and series acceleration), and studies to apply integrable systems to numerical computation are rapidly advancing.
Integrable difference schemes
Generally, it is hard to accurately compute the solutions of nonlinear differential equations due to its non-linearity. In order to overcome this difficulty, R. Hirota has made discrete versions of integrable systems with the viewpoint of "Preserve mathematical structures of integrable systems in the discrete versions".
At the same time, Mark J. Ablowitz and others have not only made discrete soliton equations with discrete Lax pair but also compared numerical results between integrable difference schemes and ordinary methods. As a result of their experiments, they have found that the accuracy can be improved with integrable difference schemes at some cases.
References
See also
Soliton
Integrable system
Numerical analysis
Computational science
Applied mathematics
Partial differential equations | Integrable algorithm | [
"Physics",
"Mathematics"
] | 275 | [
"Integrable systems",
"Applied mathematics",
"Theoretical physics",
"Computational mathematics",
"Computational science",
"Mathematical relations",
"Numerical analysis",
"Approximations"
] |
63,570,283 | https://en.wikipedia.org/wiki/NGC%20656 | NGC 656 is a barred lenticular galaxy located in the Pisces constellation about 175 million light-years from the Milky Way. It was discovered by the Prussian astronomer Heinrich d'Arrest in 1865.
See also
List of NGC objects (1–1000)
Heinrich d'Arrest
References
External links
Barred lenticular galaxies
0656
Pisces (constellation)
006293 | NGC 656 | [
"Astronomy"
] | 77 | [
"Pisces (constellation)",
"Constellations"
] |
63,570,288 | https://en.wikipedia.org/wiki/Tonk%20meteorite | Tonk is a small carbonaceous chondrite meteorite that fell near Tonk, India in 1911. Despite its small size, it is often included in studies due to its compositional similarity to the early solar system.
Composition and classification
The meteorite consists of fragments that together weigh and fell near the city of Tonk in India near midday on 22 January 1911. It is one of five known meteorites belonging to the CI chondrite group. This group is remarkable for having an elemental distribution that has the strongest similarity to that of the solar nebula. Except for certain volatile elements, like carbon, hydrogen, oxygen, nitrogen and the noble gases, which are not present in the meteorite, the ratios of the elements are very similar. Notably though, the meteor is highly enriched in volatile mercury which is undetectable in the solar photosphere, and this is a major driver of the "mercury paradox" that mercury abundances in meteors do not follow its volatile nature and isotopic ratios based expected behaviour in the solar nebula. These features mean that it is often, despite its small size, included in meteorological studies. The meteorite contains dolomite, magnesite, magnetite, pentlandite and pyrrhotite.
Alternative names
The meteorite is also known as Chhabra and Jhalrapatan.
See also
Glossary of meteoritics
References
Astrobiology
Meteorites found in India
Geology of Rajasthan | Tonk meteorite | [
"Astronomy",
"Biology"
] | 293 | [
"Origin of life",
"Speculative evolution",
"Astrobiology",
"Biological hypotheses",
"Astronomical sub-disciplines"
] |
63,570,310 | https://en.wikipedia.org/wiki/NGC%20657 | NGC 657 is an open cluster containing very few stars or a group of stars located in the constellation Cassiopeia. It was discovered by British astronomer John Herschel in 1831.
See also
List of NGC objects (1–1000)
References
External links
Open clusters
Cassiopeia (constellation)
0657 | NGC 657 | [
"Astronomy"
] | 64 | [
"Cassiopeia (constellation)",
"Constellations"
] |
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