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56,312,430 | https://en.wikipedia.org/wiki/Breath-figure%20self-assembly | Breath-figure self-assembly is the self-assembly process of the formation of honeycomb micro-scaled polymer patterns by the condensation of water droplets. "Breath-figure" refers to the fog that forms when water vapor contacts a cold surface. In the modern era systematic study of the process of breath-figures water condensation was carried out by Aitken and Rayleigh, among others. Half a century later the interest in the breath-figure formation was revived in a view of study of atmospheric processes, and in particular the extended study of a dew formation which turned out to be a complicated physical process. The experimental and theoretical study of dew formation has been carried out by Beysens. Thermodynamic and kinetic aspects of dew formation, which are crucial for understanding of formation of breath-figures inspired polymer patterns will be addressed further in detail.
Breakthrough in the application of the breath-figures patterns was achieved in 1994–1995 when Widawski, François and Pitois reported manufacturing of polymer films with a self-organized, micro-scaled, honeycomb morphology using the breath-figures condensation process. The reported process was based on the rapidly evaporated polymer solutions exerted to humidity. The introduction to experimental techniques involved in manufacturing of micropatterned surfaces is supplied in reference 1; image representing typical breath-figures-inspired honeycomb pattern is shown in Figure 1.
The main physical processes involved in the process are: 1) evaporation of the polymer solution; 2) nucleation of water droplets; 3) condensation of water droplets; 4) growth of droplets; 5) evaporation of water; 6) solidification of polymer giving rise to the eventual micro-porous pattern. This experimental technique allows obtaining well-ordered, hierarchical, honeycomb surface patterns. A variety of experimental techniques were successfully exploited for the formation of breath-figures self-assembly induced patterns including drop-casting, dip-coating and spin-coating. Adapted techniques to achieve varied pattern morphologies and hierarchical designs have also been developed. The characteristic dimension of pores is usually close to 1 μm, whereas the characteristic lateral dimension of the large-scale patterns is ca. 10–50 μm.
See also
Self-assembly
Marangoni effect
Droplet cluster
References
Physical phenomena
Self-organization | Breath-figure self-assembly | [
"Physics",
"Mathematics"
] | 472 | [
"Self-organization",
"Physical phenomena",
"Dynamical systems"
] |
56,312,690 | https://en.wikipedia.org/wiki/Eti%20Soda | The Eti Soda Inc. is a chemical industry company in Ankara
Province, Turkey, producing natural soda ash and baking soda from trona. It was founded in 1998, and the production started in 2009. The company's main shareholder is Ciner Group.
Background
Trona ore deposits were discovered at Beypazarı, around northwest of Ankara, during drilling operations for coal exploration in 1979. Exploration works for trona ore reserve continued until 1985. According to world's leading consulting firms, mining of the trona ore at Bypazarı was not feasible with known methods. The state-owned mining company Eti Maden and the privately held Ciner Holding jointly took a risk and developed solution mining method for extraction of trona ore. The method, which was new in the world, has been then patented. In 1998, the Eti Soda Inc. was established in Ankara. The building of the soda production and cogeneration plants were completed between 2007 and 2009.
The production of soda ash started with an official inauguration ceremony, which took place in presence of Prime minister Recep Tayyip Erdoğan and Minister of Energy and Natural Resources Hilmi Güler in March 2009.
The Eti Soda Inc. is jointly owned in majority by Ciner Holding with 74% and by Eti Maden with 26%.
Plant and production
Trona ore is extracted by solution mining method. Hot water is injected into the trona ore deposit underground through bore holes drilled, which dissolves trona ore. The trona solution is pumped up and is processed to soda products as soda ash (sodium carbonate, Na2CO3) and baking soda (sodium bicarbonate, NaHCO3). The soda ash is mainly used in the glass production. Products of Eti Soda are exported all over the world, especially to European countries. From 2009 to 2013, the value of soda ash exports to 53 countries reached US$1 billion.
The annual production capacity of the Eti Soda facilities is one million tons of soda ash and 100,000 tons of baking soda. In 2010, already in its first year of the operation, the company fulfilled its production capacity. For comparison the 2022 production for the whole country was estimate at 4 to 5 million tonnes.
Environmental impact
There is a 20 MW cogeneration coal-fired power station. Climate Trace estimated a 3570 million tonne source of greenhouse gas from soda ash in Turkey in 2022, but had low confidence in its estimate and had not been able to identify the company. ETI Soda aims to reduce its total scope 1 and 2 greenhouse gas emissions by almost 30% from 2021 to 480 million tonnes a year by 2028.
See also
Ciner Wyoming, United States
Kazan Soda Elektrik, Turkey
References
Ciner Glass and Chemicals Group
Mining companies of Turkey
Chemical companies of Turkey
Chemical plants
Industrial buildings in Turkey
Industrial buildings completed in 2009
Chemical companies established in 1998
Non-renewable resource companies established in 1998
Turkish companies established in 1998
Companies based in Ankara
Beypazarı District
21st-century architecture in Turkey | Eti Soda | [
"Chemistry"
] | 619 | [
"Chemical process engineering",
"Chemical plants"
] |
66,120,130 | https://en.wikipedia.org/wiki/NordLocker | NordLocker is a file encryption software integrated with end-to-end encrypted cloud storage. It is available on Windows and macOS. NordLocker is developed by Nord Security, the Lithuania-based company behind the NordVPN virtual private network.
NordLocker uses a freemium business model, where users are offered a free account with unlimited local file encryption and a set amount of cloud storage with sync and backup features. More cloud storage is available via a paid subscription.
History
In May 2019, NordVPN announced the upcoming launch of NordLocker, "an app with a zero-knowledge encryption process". Although the initial estimated time of arrival was summer 2019, the actual launch took place in November. The app was launched as a local file encryption tool with secure sharing. Users were able to encrypt up to 5 GB of data for free or pay for unlimited encryption.
In March 2020, NordLocker announced newly implemented cloud sharing integrations with Dropbox and Google Drive.
In August 2020, NordLocker launched a cloud storage add-on, a feature allowing users to back up their data and synchronize it across multiple devices.
Features
NordLocker is an encryption software with cloud integration. The software uses so called "lockers" - encrypted folders to encrypt and store user files. Users can create an unlimited number of lockers, drop files in to encrypt them, and transfer lockers separately.
The app uses client-side encryption to secure files on the user's device first. It's a zero-knowledge encryption system, where the developers have no data about users' files. After the encryption process, the user can decide whether to store data locally or sync it via NordLocker’s cloud. NordLocker syncs files via a private cloud, so they can be accessed from any computer with the NordLocker app installed.
The program uses AES-256 and 4096-bit RSA encryption algorithms as well as Argon2 and ECC (with XChaCha20, EdDSA, and Poly1305). NordLocker uses Libsodium to generate a random 256-bit key and encrypt lockers. To encrypt that key, the app then uses XChaCha20-Poly1305 and the user’s master password.
The local encryption is free as of December 2020 — the service monetizes cloud storage space beyond the 3 GB provided with the free plan.
Hacking contest
In April 2020, NordLocker launched the "NordLocker Bounty campaign", a hacking competition with the top prize of $10,000. To win, a person had to download an encrypted "locker" from the company's site, hack into it, and find the hidden message. Based on the NordLocker’s campaign page, there were over 600 attempts to break the locker but no one has claimed the bounty as of December 2020.
Reception
A June 2020 PCMagazine review noted that NordLocker was easy to use but lacked features like secure file deletion and two-factor authentication. In August 2020, ITPro called NordLocker’s cloud add-on a “critical feature for modern business, especially with the coronavirus outbreak forcing many companies’ workforces to remain remote.” Restore Privacy praised NordLocker for strong end-to-end encryption and the "new, lower price" but mentioned the fact that NordLocker is not open-source.
Boxcryptor, another encryption service, has compared NordLocker’s security to their own but noted that NordLocker does not have a mobile application.
See also
Encryption
Internet privacy
Secure communication
References
External links
Cryptographic software
Proprietary cross-platform software
Cloud storage
Internet properties established in 2019 | NordLocker | [
"Mathematics"
] | 787 | [
"Cryptographic software",
"Mathematical software"
] |
66,121,195 | https://en.wikipedia.org/wiki/Matrix%20%28composite%29 | In materials science, a matrix is a constituent of a composite material.
Functions
A matrix serves the following functions:
It binds the fiber reinforcement.
It provides the composite component its shape and directs its surface quality.
Organic Matrices
Traditional materials such as glues, muds have traditionally been used as matrices for adobe and papier-mâché.
The common matrices are polymers (mainly utilized for fibre reinforced plastics). The most common polymer-based composite materials which include carbon fibre, fibreglass and Kevlar, typically involve two parts at least, the resin and the substrate. Asphalt concrete, which is often used in the construction of roads, has a matrix called bitumen. Mud (wattle and daub) has observed considerable use.
Epoxy is utilized as a structural glue or structural matrix material in the aerospace industry. Epoxy resin is, when cured, nearly transparent.
Polyester resin is fit for most backyard projects. It tends to have a yellowish colour. It is often used in the construction of surfboards and for marine applications. They are usually coated as they can tend to deteriorate over time and sensitive to ultraviolet. Peroxide is considered as the hardener of polyester resin. Mostly, MEKP (methyl ethyl ketone peroxide) is considered for polyester resin. A curing reaction is initiated when the peroxide is combined with the resin, and decomposes to generate free radicals. In these systems, often hardeners are called catalysts. But they do not meet the strictest chemical definition of a catalyst as at the end of the reaction they do not re-appear unchanged.
Vinyl ester resin has a lower viscosity than polyester resin and is more transparent. It also tends to have a purplish to bluish to greenish tint. The price of the vinyl ester resin is similar to that of the polyester resin. It utilizes the same hardeners as polyester resin (at a similar mix ratio). It doesn't degrade much over time, when compared to polyester resin, and is more flexible. Generally, vinyl ester resin is considered as fuel resistant. However, it will melt when in contact with gasoline.
Shape memory polymer (SMP) resins are those materials that their shape and can be modified regularly by heating above their glass transition temperature (Tg). They become elastic and flexible when heated, allowing for easy configuration. They maintain their new shape when they are cooled. When they are reheated above their Tg, they will return to their original shape. The benefit of these resins is that without losing their material properties, they can be shaped and reshaped regularly. These resins can be utilized in making shape memory composites. Depending on their formulation, they have varying visual characteristics. These resins can be utilized in very cold temperature applications, such as for sensors that show whether perishable goods have warmed above a particular maximum temperature when they are acrylate-based; in space applications when they are cyanate-ester-based; in auto body and outdoor equipment repairs when they are epoxy-based.
Inorganic Matrices
Cement (concrete), ceramics, sometimes glasses and metals are employed. Unusual matrices such as ice are sometimes proposed as in pykecrete.
References
Composite materials | Matrix (composite) | [
"Physics"
] | 675 | [
"Materials",
"Composite materials",
"Matter"
] |
66,121,805 | https://en.wikipedia.org/wiki/Pam%20%26%20Tommy | Pam & Tommy is a 2022 American biographical drama television miniseries chronicling the marriage between actress and model Pamela Anderson and Mötley Crüe drummer Tommy Lee, played by Lily James and Sebastian Stan, respectively, during the period their unauthorised sex tape was made public. Based on the 2014 Rolling Stone article "Pam and Tommy: The Untold Story of the World's Most Infamous Sex Tape" by Amanda Chicago Lewis, the series was created for Hulu by Robert Siegel, and is produced by Point Grey Pictures and Annapurna Television.
The series development was announced in 2018, with James Franco attached to direct the miniseries and play Lee. It was given a series order in December 2020 by Hulu, announcing James to play Anderson and Stan to replace Franco following the latter's departure from the project. Casting announcements were made throughout 2021 and filming took place in Los Angeles between April and July 2021.
The first three episodes of Pam & Tommy premiered on Hulu on February 2, 2022, and were directed by Craig Gillespie, with the rest of the episodes debuting weekly. It received ten Primetime Emmy Award nominations, including Outstanding Limited Or Anthology Series and acting nominations for James, Stan, and Rogen.
Premise
Pam & Tommy depicts the turbulent 3-year marriage between Pamela Anderson and Tommy Lee, with particular emphasis on the theft and illegal distribution of an infamous sex tape the couple recorded privately during their honeymoon.
Cast and characters
Main
Lily James as Pamela Anderson
Sebastian Stan as Tommy Lee
Nick Offerman as Uncle Miltie
Seth Rogen as Rand Gauthier
Taylor Schilling as Erica Gauthier
Recurring
Pepi Sonuga as Melanie
Andrew Dice Clay as Butchie
Mozhan Marnò as Gail Chwatsky
Fred Hechinger as Seth Warshavsky
Paul Ben-Victor as Richard Alden, Pam and Tommy's lawyer
Mike Seely as Hugh Hefner
Medalion Rahimi as Danielle, Erica's girlfriend
Don Harvey as Anthony Pellicano, a private investigator
Adam Ray as Jay Leno
Guest
Jason Mantzoukas as the voice of Tommy's penis (in "I Love You, Tommy")
Maxwell Caulfield as Bob Guccione, the owner of Penthouse (in "Uncle Jim and Aunt Susie In Duluth")
John Billingsley as the Penthouse defense counsel (in "Pamela in Wonderland")
Brian Huskey as Gambler in Debt (in "Destroyer of Worlds")
Clint Howard as himself playing his character Schmitz in Barb Wire (in "Destroyer of Worlds")
Production
Development
The series is based on a 2014 Rolling Stone article about the theft of the tapes. Siegel found it hard to believe the events had not been the subject of a film or series previously, with the producers optioning the rights to the article to serve as the basis of the series. Co-showrunners Siegel and D.V. DeVincentis argue that most of the "basic plot beats" came from that article.
The series was first announced in 2018, with Seth Rogen and Evan Goldberg developing the project under their production company Point Grey Pictures and James Franco attached to direct the miniseries and play Tommy Lee. By December 2020, Franco had left the series and it was announced that Hulu had greenlit the project with an eight-episode limited series order. Craig Gillespie was set to direct with Robert D. Siegel writing and Rogen and Goldberg executive producing the miniseries. Tatiana S. Riegel, a frequent collaborator of Gillespie's, was attached as editor.
Casting
Alongside the series order announcement, Lily James and Sebastian Stan were cast to play the titular characters, with Rogen also cast in a main role. In April 2021, Nick Offerman and Taylor Schilling were announced as main cast members, with Pepi Sonuga, Andrew Dice Clay, Spenser Granese and Mozhan Marnò in recurring roles. In June 2021, Fred Hechinger was announced as a part of the cast in a recurring role. In January 2022, it was revealed that Jason Mantzoukas was voicing Tommy Lee's penis.
Filming
The series began filming on April 5, 2021, in Los Angeles and finished on July 30, 2021. The two main actors went through long make-up processes to closely resemble their characters. Lily James wore a prosthetic forehead, chest, dentures, blue contact lenses, and a blonde wig. Sebastian Stan spent hours getting up to 30 tattoos painted on him, grew out and dyed his hair, and wore brown contact lenses, a prosthetic penis, and pierced nipples. Their wardrobe was not custom made, but purchased second-hand based on the clothes Anderson and Lee wore during that period of 1995–1998.
Episodes
Release
Pam & Tommy premiered on February 2, 2022, on Hulu, with the first three episodes and the rest debuting on a weekly basis. The series was also released simultaneously internationally on Disney+ under the Star hub (including Hotstar in India), and on Star+ in Latin America.
Reception
Viewership
According to market research company Parrot Analytics, which looks at consumer engagement in consumer research, streaming, downloads, and on social media, Pam & Tommy reached second place among breakout shows, which are the most in-demand series that have premiered in the past 100 days, during its first full week of data from February 5-11, 2022, achieving 32.9 times the average series demand. It was the third most in-demand breakout series from February 26 - March 4, 2022. It and ranked as the fourth most in-demand new show during the week of March 12-18, 2022. Nielsen Media Research, which records streaming viewership on U.S. television screens, reported that the series was watched for 312 million minutes. Whip Media, which tracks viewership data for the more than 19 million worldwide users of its TV Time app, calculated that Pam & Tommy was the tenth most-watched original series across all platforms in the United States during the week of February 6, 2022. It later climbed to sixth place during the week of March 13, 2022.
Critical reception
The review aggregator website Rotten Tomatoes reports a 78% approval rating based on 102 reviews, with an average rating of 7.3/10. The site's critical consensus reads: "Pam & Tommy sometimes undercuts its own critique of cultural voyeurism with lurid stylization, but Lily James' performance gives this sleazy opus an undeniable heart." On Metacritic, the series has a score of 70 out of 100, based on 42 reviews, indicating "generally favorable reviews".
James Poniewozik of The New York Times found the show "consistently entertaining" and praised the performances of the actors, calling James' portrayal a "sneakily complex performance", and complimented the narrative alongside the practical effects. Alison Foreman of Mashable praised the performances of the whole cast, especially James and Stan, complimented the soundtrack and pace, and stated that the show keeps "the entertainment value high". Inkoo Kang of The Washington Post stated that the transformation of James and Stan is a "casting and makeup coup", while saying that the production is admirable due to its "madeleine-esque needle drops to its relish in the baggy tackiness of so much '90s fashion.," although claiming that the show exploits Anderson's story. Alec Bojalad of Den of Geek reviewed Pam & Tommy positively, stating that James as Anderson and Stan as Lee are "excellent choices", praising the development of the characters, and saying that "it transports viewers into the mind of a real woman enduring real internet-era trauma."
Lucy Mangan of The Guardian rated the miniseries 4 out of 5 stars, saying that Pam & Tommy is a "warm, funny, intelligent and rather moving drama," while calling the performances from Lily James as Anderson and Sebastian Stan as Lee "astonishing", stating that "each achieve the feat of uncannily resembling – aesthetically, vocally, and in every mannerism – the real-life people, without descending into mimicry." Abhishek Srivastava of The Times of India rated the series 4 out of 5 stars, praised the performances of the actors and Craig Gillespie's direction, and stated that the miniseries manages to provide a captivating story. Martin Brown of Common Sense Media rated the series 3 out of 5 stars, writing, "In real life, Anderson and Tommy Lee came off as slightly more sympathetic than they do in this version of the story, which focuses more on the sensational aspects of the story and characters than on why they might be relevant to viewers nearly 25 years later."
Clint Worthington of RogerEbert.com rated the series 2.5 out of 4 stars and said that the series is entertaining, called the performances of the actors "strong" and the direction "stylish", but found that the show is a violation of privacy that is "filtered through the glossy lens of prestige TV." Laura Martin of BBC rated the show 2 out of 5 stars, complimented the performances of James and Stan, and found some scenes amusing, but stated that the show exploits the traumatic personal life of Anderson.
Response from Pamela Anderson
In her 2023 Netflix documentary Pamela, a Love Story, Pamela Anderson said that she was not consulted about the production of the series. Critics, journalists, and academics posited that the series was profiting off of Anderson's trauma without her consent, and likely doing further harm to her. Pamela, a Love Story verified those claims, in Anderson's own words. Producers of the series were able to develop the series without her participation, permission, or consent by optioning the rights to an article published by Rolling Stone in 2014. Some critics felt that this was a similar violation of privacy that mirrored the tape originally being stolen and distributed without Anderson's and Lee's consent.
Accolades
Further reading
Fred J. Lincoln, Oral History Interview, Leather Archives & Museum
Notes
See also
Tabloid television
Dark Side of the 90s
References
External links
Amanda Chicago Lewis. (2014) "Pam and Tommy: The Untold Story of the World's Most Infamous Sex Tape", Rolling Stone article that was the basis for the series
2020s American drama television miniseries
2020s American romance television series
2020s romantic drama television series
2022 American television series debuts
2022 American television series endings
American biographical series
American romantic drama television series
Cultural depictions of Pamela Anderson
American English-language television shows
Hulu original programming
Mötley Crüe
Television duos
Television series about actors
Television series about marriage
Television series based on actual events
Television series by Lionsgate Television
Television series set in 1995
Television series set in 1996
Television shows filmed in Los Angeles
Television shows set in Los Angeles
Works about the Internet
Works based on periodical articles
Television series set in the 1990s
Primetime Emmy Award–winning television series
Television series about pornography | Pam & Tommy | [
"Technology"
] | 2,212 | [
"Works about the Internet",
"Works about computing"
] |
66,122,519 | https://en.wikipedia.org/wiki/Jiquan%20Chen | Jiquan Chen is a landscape ecologist, primarily focused on nutrient flux, carbon cycling, bioenergy, and grassland ecology. He currently leads the LEES lab at Michigan State University.
Early life and education
Chen was born in Shanxi, Northern China. His parents were farmers. He graduated Inner Mongolia University in 1983 with an undergraduate degree in grassland plant ecology, received his MS in forest ecology in 1986 from the Chinese Academy of Science, and his PhD in ecosystem analysis from the University of Washington in 1991. From 1992 to 1993 he completed postdoc training in stream ecology and ecosystem management also at the University of Washington.
Career and research
Chen has worked as an ecologist, professor, author, and editor. His research is focused on ecosystem nutrient flux, fragmented landscapes, agriculture, grasslands, hydrology, global change, and bioenergy. In 1999, he was a Bullard Fellow at Harvard University Forest. He is the chief scientist and founder of the US-China Carbon Consortium. From 1993 to 2001 he was a faculty member at Michigan Tech University, and from 2001 to 2014 he was a faculty member at the University of Toledo. In 2014, he became a professor of geography at Michigan State University, where he currently directs the Landscape Ecology and Ecosystem Science lab (LEES). This lab focuses on water and carbon cycles across ecosystems, bioenergy resources, and how human activities contribute to climate change feedback cycles. Chen is an Editor-in-Chief for Ecological Processes. He has been an author on over 300 papers, and 11 books. His research has been funded by NASA and the NSF
Awards and recognition
Chen was elected an AAAS Fellow in 2011 and an ESA Fellow in 2014
Notable publications
Books
Gutman, G., J. Chen,G., Henebry(Eds.). 2020. Landscape Dynamics of Drylands across Greater Central Asia: People, Societies, and Ecosystems.
Chen,J.2020. Biophysical Models and Applications in Ecosystem Analysis. HEP and MSU Press. (to be published in 2020).
Bhardwaj, A. K., Zenone, T., and Chen, J.(Eds.) 2015. Sustainable Biofuels: An Ecological Assessment of Future Energy. De Gruyter, 346pp.
Chen, J., Wan, S., Henebry, G., Qi, J., Gutman, G., Sun, G., and Kappas, M. (Eds.) 2013. Dryland East Asia (DEA): Land Dynamics Amid Social And Climate Change. HEP and De Gruyter, 470 pp.
Chen, J.and Yang, S. (Eds.) 2014. Methods for Terrestrial Ecosystem Studies. Higher Education Press 362 pp.
Li, C., Lafortezza, R., and Chen, J.(Eds.) 2010. Landscape Ecology in Forest Management and Conservation. HEP and Springer, 424pp.
Lafortezza, R., Chen, J., Sanesi, G., and Crow, T. R. (Eds.) 2008. Patterns and Processes in Forest Landscapes. Springer-Verlag. 425pp.
Chen, J., Liu, S., Lucas, R., Sun, P., Lafortezza, R., and Delp Taylor, L. (Eds.) 2008. Landscape Ecology and Forest Management: challenges and solutions. The Proceedings of the International Conference of IUFRO8.01.02. Chengdu, P.R. China. 192pp.
Gu, B., Wu, J., Wu, Y., Dong, Q., and Chen, J.(Eds.) 2008. Green Career –poem and essay collection written by Chinese Ecologists overseas. Higher Education Press, 171pp.
Papers
Disturbances and structural development of natural forest ecosystems with silvicultural implications, using Douglas-fir forests as an example. JF Franklin, TA Spies, R Van Pelt, AB Carey, DA Thornburgh, DR Berg, Forest ecology and management 155 (1–3), 399–423
Recent decline in the global land evapotranspiration trend due to limited moisture supply. M Jung, M Reichstein, P Ciais, SI Seneviratne, J Sheffield, ML Goulden, Nature 467 (7318), 951–954
Edge influence on forest structure and composition in fragmented landscapes. KA Harper, SE Macdonald, PJ Burton, J Chen, KD Brosofske, Conservation biology 19 (3), 768–782
Microclimate in forest ecosystem and landscape ecology: variations in local climate can be used to monitor and compare the effects of different management regimes. J Chen, SC Saunders, TR Crow, RJ Naiman, KD Brosofske, GD Mroz, BioScience 49 (4), 288–297
Global patterns of land‐atmosphere fluxes of carbon dioxide, latent heat, and sensible heat derived from eddy covariance, satellite, and meteorological observations, M Jung, M Reichstein, HA Margolis, A Cescatti, AD Richardson, MA Arain, Journal of Geophysical Research: Biogeosciences 116 (G3)
Growing‐season micro climatic gradients from clear cut edges into old‐growth Douglas‐fir forests, J Chen, JF Franklin, TA Spies Ecological Applications 5 (1), 74–86
Modeling and measuring the effects of disturbance history and climate on carbon and water budgets in evergreen needleaf forests, JPS Thornton, P.E., B.E. Law, H.L. Gholz, K.L. Clark, Agricultural and Forest Meteorology 113, 185–222
Vegetation responses to edge environments in old‐growth Douglas‐fir forests, J Chen, JF Franklin, TA Spies, Ecological applications 2 (4), 387–396
Contrasting micro climates among clearcut, edge, and interior of old-growth Douglas-fir forest, J Chen, JF Franklin, TA Spies, Agricultural and forest meteorology 63 (3–4), 219–237
Estimating above ground biomass using Landsat 7 ETM+ data across a managed landscape in northern Wisconsin, USA, D Zheng, J Rademacher, J Chen, T Crow, M Bresee, J Le Moine, SR Ryu, Remote sensing of environment 93 (3), 402–411
Harvesting effects on micro climatic gradients from small streams to uplands in western Washington, KD Brosofske, J Chen, RJ Naiman, JF Franklin, Ecological applications 7 (4), 1188–1200
Other interests
Chen enjoys practicing Tai Chi and Buddhist Meditation in his free time.
References
External links
Living people
Year of birth missing (living people)
University of Washington alumni
Michigan State University faculty
People from Shanxi
Inner Mongolia University alumni
Michigan Technological University faculty
University of Toledo faculty
Ecologists
Fellows of the American Association for the Advancement of Science
Chinese emigrants to the United States | Jiquan Chen | [
"Environmental_science"
] | 1,442 | [
"Ecologists",
"Environmental scientists"
] |
66,122,548 | https://en.wikipedia.org/wiki/Polymateria | Polymateria Ltd is a British technology company developing biodegradable plastic alternatives. In 2020, the privately owned company was the first to achieve certified biodegradation of the most commonly-littered forms of plastic packaging in real-world conditions, in less than a year without creating microplastics.
History
Polymateria was founded in 2015 at Imperial College London by Jonathan Sieff and Lee Davy-Martin. Between 2016 and 2017, it was based at the Imperial White City Incubator, and since 2017 has been headquartered at the nearby Translation & Innovation Hub (I-HUB). In January 2018, Niall Dunne became CEO, and in March 2018 the company brought its first product to market.
Prince Charles visited the Polymateria laboratories in March 2019.
In October 2019, Polymateria announced a partnership with specialty chemical company Clariant to bring its new Biotransformation technology to the Southeast Asian market.
A subsequent partnership agreement between Polymateria, Clariant and the Indian Ministry of Chemicals and Fertilizers announced in January 2020 aims to bring Biotransformation to India.
In July 2020, the impact investing platform Planet First Partners (PFP) invested £15 million in Polymateria. Alongside the investment, several people joined the Polymateria board, including PFP head Frédéric de Mévius and former Marks & Spencer CEO Marc Bolland as chairman. The same month, it was reported that Puma would be the first company to use Polymateria's technology in the 160 million plastic bags it used each year, starting September 2020 in Southeast Asian markets, and in Britain in 2021.
The family of Hong Kong billionaire Silas Chou, whose daughter Veronica Chou was said to be pushing for more sustainability in the fashion industry, invested in Polymateria in 2020.
Two years after Polymateria CEO Niall Dunne announced his company's intention to become the "Tesla of plastics",
in November 2020, former Tesla executive Steven Altmann-Richer joined Polymateria as head of public affairs and regulatory strategy. Also in November 2020, the company hinted that its product was already being tested in commercial food packaging in the UK, Spain, Portugal, Taiwan and Kenya, although it did not reveal which brands or products were involved.
In February 2021, clothing company Pour les Femmes announced that it would be using Polymateria's biodegradable plastic in its packaging. Electric racing series Extreme E revealed in March 2021 its partnership with Polymateria, which will supply cups and food packaging for the event, and later collect these for recycling.
In April 2021, FiberVisions and Avgol, two companies owned by Thai Indorama Ventures, partnered with Polymateria, planning to apply the technology to their nonwoven fabrics, which are used for products like face masks and diapers.
The company signed a deal in September 2021 with Taiwanese Formosa Plastics Corp, potentially worth US$100 million in license fees. By then, Polymateria's plastics were also used in some of the packaging of Taiwanese 7-Eleven stores.
The technology was demonstrated during the 2022 Chicago Marathon, on sugarcane-based recovery bags for the runners.
Since 2023, their technology has been branded as "Lyfecycle", and in that same year was applied to plastic bags from Indian fashion brand Doodlage.
In April 2023, Polymateria partnered with Toppan Specialty Films, an Indian plastic manufacturer based in the Punjab region. In May 2023, the company received another £20 million investment, while also signing a deal with a subsidiary of Lotte Chemical to develop products in Malaysia. After the £20 million investment, CEO Dunne announced expansion plans for the company, and also hinted that turnover was in the lower millions, and that the company had experienced growth of 300% between 2021 and 2022.
By January 2024 the company had introduced a biodegradeable baler twine which was produced by a Portuguese firm.
Biodegradable plastics
Biotransformation technology
The company has developed a technology called Biotransformation, which involves adding a masterbatch to plastics during production to aid their decomposition.
The technology is applicable to polyolefins, which include the most commonly littered types of plastics: polyethylene (e.g. plastic bags, packaging) and polypropylene (e.g. plastic cups, bottle caps).
Although these plastics can still be recycled, they will also decompose into a waxy substance in less than a year, provided they are exposed to environmental conditions such as sunlight, air and water. Ecotoxicity tests have shown that this intermediary wax is "non-harmful for contact with soil, plants and the aquatic environment". Bacteria and fungi will then digest the wax and break it down into carbon dioxide and water. It does not leave behind microplastics, a common problem of previous biodegradable products. According to Polymateria, this is achieved because the additives do not just break down the amorphous, but also the crystalline regions of the polymer. The resulting substance thus has a molecular weight of only around 6001000 daltons, compared to existing technologies which were unable to get below 5000 daltons. At these lower levels, the polymer is broken down enough to become a waxy substance biologically available to microbes.
Under sub-optimal conditions, degradation might take slightly longer, with an experimental flowerpot taking up to two years to dissolve if "tossed in a ditch".
The company claims that the onset of biodegradation can be precisely time-controlled, so plastics won't deteriorate before recycling can happen. CEO Dunne said it was looking to apply "terms consumers understand" to the new packaging, such as "recycle-by dates or where recycling isn’t an option dispose-by dates".
Production of the additive in form of a masterbatch was done at a factory in Clermont-Ferrand in 2020, but the company was in talks for a larger facility in India. The technology is expected to increase the cost of packaging by 10 to 15 percent.
A study of Polymateria's plastic biodegradation performance was published in Polymers in July 2021.
BSI standard
In 2020, a new British standard for biodegradability named PAS 9017 was adopted by the BSI Group. Polymateria had sponsored the standard, which was reviewed by the Waste & Resources Action Programme (WRAP), the Department for Environment, Food and Rural Affairs and the Department for Business, Energy and Industrial Strategy. Polymateria's product became the first to reach the new benchmark. Ecologist Dannielle Green of Anglia Ruskin University, who was involved in validating the standard, called it a "step in the right direction" and praised the "interdisciplinary collaborative approach" taken by the BSI.
Criticism and rebuttal
The BSI standard was criticised on 22 October 2020 in an open letter by a group of 40 organizations, including Tesco, Aldi and the Environmental Services Association. The letter called upon the UK government to "follow the lead" of the European Union in banning oxo-degradable plastics, warning of the dangers of "microplastics [...] entering the food chain" and claiming that "degradable plastic alternatives will disrupt [Britain]'s recycling facilities". WRAP, a registered charity that was on the steering committee for the standard, responded to inquiries by declaring that its involvement should not be mistaken as an endorsement of the standard. However, WRAP maintained that littering was a "real issue" and that it would continue to encourage "developments in plastics technologies which have no negative impact on the ability for plastic to be effectively recycled and have no negative impacts to the natural environment". After a "small but significant anomaly" was found in the BSI consultation process, WRAP said in December 2020 that the committee was due to meet in January the next year to discuss details of the testing process for microplastics.
However, Polymateria's Biotransformation technology does not involve the oxo-degradable plastics criticised by the open letter, which are often confused with biodegradable plastics. It also does not produce microplastics (as required by the PAS 9017 standard), and the company insists its chemical additive has "no adverse impact on recycling streams".
Environmental organizations that have criticized the BSI standard have included the WWF and Keep Britain Tidy, which voiced concerns that degradable plastics would increase littering.
Polymateria CEO Dunne countered by declaring that the main problem were exports to non-EU countries where the plastic waste was "not being recycled and is winding up in unmanaged waste systems." The BSI has responded by calling littering "illegal" and a "complex behavioural issue", voicing doubts that any standard would be able to "control how a member of the public acts". The "recycle-by" date stamped on Polymateria's plastics is also meant to encourage consumers to recycle the product, instead of throwing it away.
See also
Biodegradable polymer
Circular economy
Notes
References
External links
Video interview with Polymateria CEO Niall Dunne by Dr. Miniya Chatterji
2015 establishments in England
Privately held companies based in London
Biodegradable waste management | Polymateria | [
"Chemistry"
] | 1,910 | [
"Biodegradation",
"Biodegradable waste management"
] |
66,123,218 | https://en.wikipedia.org/wiki/ALC-0315 | ALC-0315 ([(4-hydroxybutyl)azanediyl]di(hexane-6,1-diyl) bis(2-hexyldecanoate)) is a synthetic lipid. A colorless oily material, it has attracted attention as a component of the SARS-CoV-2 vaccine, BNT162b2, from BioNTech and Pfizer. Specifically, it is one of four components that form lipid nanoparticles (LNPs), which encapsulate and protect the otherwise fragile mRNA that is the active ingredient in these drugs. These nanoparticles promote the uptake of therapeutically effective nucleic acids such as oligonucleotides or mRNA both in vitro and in vivo.
Below physiological pH, ALC-0315 becomes protonated at the nitrogen atom, yielding an ammonium cation that is attracted to the messenger RNA (mRNA), which is anionic.
Synthesis
The preparation of ALC-0315 was first described in a patent application to lipid nanoparticles by Acuitas Therapeutics in 2017. The final step is a reductive amination reaction in which 4-aminobutanol is condensed with a lipid aldehyde, using sodium triacetoxyborohydride as the reducing agent to convert the intermediate imines to the amine of the product.
2 (C8H17)(C6H13)CHCO2(CH2)5CHO + H2N(CH2)4OH + 2 NaBH(O2CCH3)3 → ALC-0315
Use
ALC-0315 is one of the components of the BNT162b2 vaccine (0.43 mg per dose). Its chemical properties as a tertiary amine mean that its cation can form an ionic bond to the messenger RNA which carries the genetic information for the SARS-CoV-2 spike protein formation in the human body. Importantly, once the lipid nanoparticle which encapsulates the mRNA has been absorbed into antigen-presenting cells (a process called receptor-mediated endocytosis) the more acidic environment within the endosome fully protonates the ALC-0315 as a result the nanoparticle releases its payload of mRNA. In December 2021 there were objections raised against the use of ALC-0315 and ALC-0159 (and some other solid lipid nanoparticles) in humans by critics of mRNA-COVID-19 vaccines in Germany but the German pharmaceutical trade journal Pharmazeutische Zeitung (de) and the German investigative collective Correctiv refuted this and stated as one important reason that the European Medicines Agency has approved the vaccine and this includes all its ingredients.
See also
Pfizer–BioNTech COVID-19 vaccine nanoparticle ingredients
ALC-0159
1,2-distearoyl-sn-glycero-3-phosphocholine
Cholesterol
References
Esters
Amines
Lipids
Primary alcohols | ALC-0315 | [
"Chemistry"
] | 649 | [
"Biomolecules by chemical classification",
"Esters",
"Functional groups",
"Organic compounds",
"Amines",
"Bases (chemistry)",
"Lipids"
] |
66,123,259 | https://en.wikipedia.org/wiki/Peter%20T.%20Ellison | Peter Thorpe Ellison (born 1951) is an American anthropologist who researches human reproductive ecology. His work has been recognized with a Guggenheim Fellowship and membership of the National Academy of Sciences, among other honors. He has also served as the editor-in-chief of the American Journal of Human Biology and American Journal of Physical Anthropology and editor of Annual Review of Anthropology.
Early life and education
Peter Thorpe Ellison was born in 1951 to parents John W. Ellison, an Episcopal reverend, and Mary . He initially went to St. John's College in Annapolis, Maryland, where he at first majored in humanities. Upon reading Darwin's On the Origin of Species, he became more interested in biology and transferred to the University of Vermont, finishing his undergraduate degree in 1975. He graduated from the University of Massachusetts with his master's degree in 1980. He later attended Harvard University for his PhD.
Career
Ellison researches how the human reproductive system interacts with external factors, which is known as human reproductive ecology. After finishing his PhD, he accepted a position in 1983 to remain at Harvard, where he currently works. He has served as the chair of Department of Anthropology and dean of the Graduate School of Arts and Sciences at different points.
He has been the editor-in-chief of several academic journals, including the American Journal of Human Biology, Annual Review of Anthropology, and American Journal of Physical Anthropology. He has authored or edited several books, including Reproductive Ecology and Human Evolution (2001), On Fertile Ground (2001), and Endocrinology of Social Relationships (2009).
Awards and honors
In 1998 he was awarded a Guggenheim Fellowship for his research. He was elected as a member of the National Academy of Sciences in 2006. In 2019 he received the Franz Boas Lifetime Achievement Award from the Human Biology Association. He is also a fellow of the American Association for the Advancement of Science.
Personal life
His wife, Priscilla "Pippi" , also attended St. John's, which is where they met as freshman.
They were married at age 21 and both transferred to the University of Vermont.
References
21st-century American anthropologists
1951 births
St. John's College (Annapolis/Santa Fe) alumni
University of Vermont alumni
University of Massachusetts Amherst alumni
Harvard University alumni
Harvard University faculty
Members of the United States National Academy of Sciences
Fellows of the American Association for the Advancement of Science
Living people
Annual Reviews (publisher) editors
Reproductive ecology | Peter T. Ellison | [
"Biology"
] | 487 | [
"Reproductive ecology",
"Behavior",
"Reproduction"
] |
66,124,572 | https://en.wikipedia.org/wiki/Maria%20Prandini | Maria Prandini (born 8 September 1969) is an Italian electrical engineer whose research topics have included control theory, pursuit–evasion, and air traffic control. She is a professor at the Polytechnic University of Milan.
Education and career
Prandini was born in Brescia, earned a laurea in electrical engineering in 1994 from the Polytechnic University of Milan, and completed her Ph.D. in 1998 at the University of Brescia, with Marco Claudio Campi as her doctoral supervisor.
After postdoctoral research with Shankar Sastry at the University of California, Berkeley, and visiting positions at Delft University of Technology and the University of Cambridge, she became an assistant professor at the Polytechnic University of Milan in 2002.
Recognition
In 2020, Prandini was named an IEEE Fellow, affiliated with the IEEE Control Systems Society, "for contributions to stochastic, hybrid and distributed control systems theory".
References
External links
Home page
1969 births
Living people
Italian electrical engineers
Italian women engineers
Control theorists
Polytechnic University of Milan alumni
University of Brescia alumni
Academic staff of the Polytechnic University of Milan
Fellows of the IEEE | Maria Prandini | [
"Engineering"
] | 223 | [
"Control engineering",
"Control theorists"
] |
66,125,058 | https://en.wikipedia.org/wiki/Glossary%20of%20the%20COVID-19%20pandemic | The COVID-19 pandemic has created and popularized many terms relating to disease and videoconferencing.
A
B
C
D
E
F
H
I
L
M
N
O
P
Q
R
S
T
V
Z
External links
Glossary on the COVID-19 pandemic - Government of Canada
Lang, Cady (December 14, 2020). "Social Distancing, Doomscroll and Defund: The Words That Defined 2020". Time.
Glossaries of biology
COVID-19 pandemic
Wikipedia glossaries using description lists | Glossary of the COVID-19 pandemic | [
"Biology"
] | 112 | [
"Glossaries of biology"
] |
66,125,330 | https://en.wikipedia.org/wiki/Quantum%20logic%20spectroscopy | Quantum logic spectroscopy (QLS) is an ion control scheme that maps quantum information between two co-trapped ion species. Quantum logic operations allow desirable properties of each ion species to be utilized simultaneously. This enables work with ions and molecular ions that have complex internal energy level structures which preclude laser cooling and direct manipulation of state. QLS was first demonstrated by NIST in 2005. QLS was first applied to state detection in diatomic molecules in 2016 by Wolf et al, and later applied to state manipulation and detection of diatomic molecules by the Liebfried group at NIST in 2017
Overview
Lasers are used to couple each ion's internal and external motional degrees of freedom. The Coulomb interaction between the two ions couples their motion. This allows the internal state of one ion to be transferred to the other. An auxiliary "logic ion" provides cooling, state preparation, and state detection for the co-trapped "spectroscopy ion," which has an electronic transition of interest. The logic ion is used to sense and control the internal and external state of the spectroscopy ion.
The logic ion is selected to have a simple energy level structure that can be directly laser cooled, often an alkaline earth ion. The laser cooled logic ion provides sympathetic cooling to the spectroscopy ion, which lacks an efficient laser cooling scheme. Cooling the spectroscopy ion reduces the number of rotational and vibrational states that it can occupy. The remaining states are then accessed by driving stimulated Raman spectroscopy transitions with a laser. The light used for driving these transitions is far off-resonant from any electronic transitions. This enables control over the spectroscopy ion's rotational and vibrational state.
Thus far, QLS is limited to diatomic molecules with a mass within 1 AMU of the laser cooled "logic" ion. This is largely due to poorer coupling of the motional states of the occupants of the ion trap as the mass mismatch becomes larger. Other techniques more tolerant of large mass mismatches are better suited to cases where the ultimate resolution of QLS is not needed, but single-molecule sensitivity is still desired.
State transfer protocol
The internal states of each ion can be treated as a two level system, with eigenstates denoted and . One of the ion's normal modes is chosen to be the transfer mode used for state mapping. This motional mode must be shared by both ions, which requires both ions be similar in mass. The normal mode has harmonic oscillator states denoted as , where n is the nth level of mode m. The wave function
denotes both ions and the transfer mode in the ground state. S and L represent the spectroscopy and logic ion. The spectroscopy ion's spectroscopy transition is then excited with a laser, producing the state:
A red sideband pi-pulse is then driven on the spectroscopy ion, resulting in the state:
At this stage, the spectroscopy ion's internal state has been mapped on to the transfer mode. The internal state of the ion has been coupled to its motional mode. The state is unaffected by the pulse of light carrying out this operation because the state does not exist. QLS takes advantage of this in order to map the spectroscopy ion's state onto the transfer mode. A final red sideband pi-pulse is applied to the logic ion, resulting in the state:
The spectroscopy ion's initial state has been mapped onto the logic ion, which can then be detected.
References
Spectroscopy | Quantum logic spectroscopy | [
"Physics",
"Chemistry"
] | 702 | [
"Instrumental analysis",
"Molecular physics",
"Spectroscopy",
"Spectrum (physical sciences)"
] |
66,125,374 | https://en.wikipedia.org/wiki/V705%20Cassiopeiae | V705 Cassiopeiae, also known as Nova Cassiopeiae 1993 was a nova which erupted in the constellation Cassiopeia during 1993. The nova was discovered at 11:17 UT on 7 December 1993 by amateur astronomer Kazuyoshi Kanatsu of Matsue, Japan, who photographed it using a 35mm camera with a 55mm f/2.8 lens. Asteroid 6976 Kanatsu was named after him in honor of this discovery. At the time of its discovery the nova had a photographic magnitude of 6.5. Around December 18, 1993, it flared briefly to magnitude 5.3 (making it visible to the naked eye), and then it returned rapidly to magnitude 6.5. It underwent a series of smaller flares until mid February 1993, after which it began a precipitous decline in brightness.
The light curve of V705 Cassiopeiae showed a very pronounced "dust dip", and its brightness fell to about 16th magnitude in mid March 1994, before rebounding to about magnitude 12.5 where it stayed for about two years, after which it declined further. This dust dip occurs when dust forms as the material ejected in the nova explosion expands and cools. The nova ultimately faded to a quiescent magnitude of 16.4.
All novae are binary stars, with a "donor" star orbiting a white dwarf. The two stars are so close to each other that material is passed from the donor star to the white dwarf. The orbital period for the binary that forms V705 Cassiopeiae is 5.472 hours. The white dwarf is estimated to have a mass of and to be receiving per year of material from the donor star.
References
Novae
Cassiopeia (constellation)
1993 in science
Cassiopeiae, V705 | V705 Cassiopeiae | [
"Astronomy"
] | 373 | [
"Novae",
"Cassiopeia (constellation)",
"Astronomical events",
"Constellations"
] |
66,125,656 | https://en.wikipedia.org/wiki/Enumeration%20reducibility | In computability theory, enumeration reducibility (or e-reducibility for short) is a specific type of reducibility. Roughly speaking, A is enumeration-reducible to B if an enumeration of B can be algorithmically converted to an enumeration of A. In particular, if B is computably enumerable, then A also is.
Introduction
In one of the possible formalizations of the concept, a Turing reduction from A to B is a Turing machine augmented with a special instruction "query the oracle". This instruction takes an integer x and instantly returns whether x belongs to B. The oracle machine should compute A, possibly using this special capability to decide B. Informally, the existence of a Turing reduction from A to B means that if it is possible to decide B, then this can be used to decide A.
Enumeration reducibility is a variant whose informal explanation is, instead, that if it is possible to enumerate B, then this can be used to enumerate A. The reduction can be defined by a Turing machine with a special oracle query instruction which takes no parameter, and either returns a new element of B, or returns no output. The oracle supplies the elements of B in any order. It can possibly return no output for some queries before resuming the enumeration. The machine should similarly the members of A, in any order and at any pace. Repetitions in the enumerations of A and B may be permitted or not; the concept is equivalent in both cases. Although this could be made precise, the definition given below is more common since it is formally simpler.
Enumeration reducibility is a form of positive reducibility, in the sense that the oracle machine receives information about which elements are in B (positive information), but no information about which elements are not in B (negative information). Indeed, if an element has not been listed yet, the oracle machine cannot know whether it will be listed later, or never.
The concept of enumeration reducibility was first introduced by the results of John Myhill, which concluded that "a set is many-one complete if and only if it is recursively enumerable and its complement is productive". This result extends to enumeration reducibility as well. Enumeration reducibility was later formally codified by Rogers and his collaborator Richard M. Friedberg in Zeitschrift für mathematische Logik und Grundlagen der Mathematik (the predecessor of Mathematical Logic Quarterly) in 1959.
Definition
Source:
Let be a standard numbering of finite subsets of , and let be a standard pairing function. A set is enumeration reducible to a set if there exists a computably enumerable set such that for all ,
When A is enumeration reducible to B, we write . The relation is a preorder. Its associated equivalence relation is denoted by .
Properties
The supremum (least upper bound, join) of sets and with respect to is given by the disjoint union
A is Turing reducible to B if and only if is enumeration reducible to , where the plus operator is defined as . Informally, this operator encodes the positive and negative information about A in a positive way. Likewise, A is computably enumerable with oracle B if and only if A is enumeration reducible to .
Furthermore, A is enumeration reducible to B if and only if, for all X such that B is computably enumerable with oracle X, it holds that A is also computably enumerable with oracle X. This is Selman's theorem.
Variants
Strong enumeration reducibilities
In addition to enumeration reducibility, there exist strong versions, the most important one being s-reducibility (named after Robert M. Solovay). S-reducibility states that a computably enumerable real set is s-reducible to another computably enumerable real set if is at least as difficult to be approximated as . This method shows similarity to e-reducibility in that it compares the elements of multiple sets. In addition, the structure of s-degrees have natural analogs in the enumeration degrees.
The reasoning for using s-reducibility is summarized by Omandaze and Sorbi as a result of positive reducibility models being unable to answer certain oracle questions (e.g. an answer to "Is ?" is only given if , and is not true for the inverse.) because they inherently model computational situations where incomplete oracle information is available. This is in contrast from the well-studied Turing reducibility, in which information is captured in both negative and positive values. In addition, T-reducibility uses information that is provided immediately and without delay. A strong reducibility is utilized in order to prevent problems occurring when incomplete information is supplied.
Partial functions
E-reducibility can be defined for partial functions as well. Writing graph , etc., we can define for partial functions :
graph graph
Kleene's recursion theorem introduces the notion of relative partial recursiveness, which, by means of systems of equations, can demonstrate equivalence through between graphs of partial functions. E-reducibility relates to relative partial recursiveness in the same way that T-reducibility relates to μ-recursiveness.
See also
Turing reduction
Many-one reduction
Truth-table reduction
Arithmetical hierarchy
References
Further reading
Introduction to Metamathematics
"Theory of Recursive Functions and Effective Computability"
Enumeration Reducibility and Polynomial Time
Reduction (complexity)
Computability theory
Mathematical logic | Enumeration reducibility | [
"Mathematics"
] | 1,194 | [
"Functions and mappings",
"Mathematical logic",
"Mathematical objects",
"Reduction (complexity)",
"Mathematical relations",
"Computability theory"
] |
66,127,146 | https://en.wikipedia.org/wiki/Simp | Simp () is an internet slang term describing someone who shows excessive sympathy and attention toward another person, typically to someone who does not reciprocate the same feelings, in pursuit of affection or a sexual relationship. This behavior, known as simping, is carried out toward a variety of targets, including celebrities, politicians, e-girls, and e-boys. The term had sporadic usage until gaining traction on social media in 2019.
Origins
Originally a shortening of "simpleton," the New Partridge Dictionary of Slang and Unconventional English traces usage of the noun simp to 1903. An article in the February 1917 edition of Motion Picture Magazine by Arthur Le Kaser has an animated drawing of a female director yelling at a male leading man through a megaphone "Kiss Her You Simp, Hurry Up Camera!" The shortening has appeared, for example, in The New York Times as early as 1923, when the paper reported on a letter by one Lillian Henderson criticizing the members of two clubs in Atlantic City for unmarried men:
Those bachelor simps are afraid to take a chance and too tight to share their earnings with a wife.
Simp began to have the connotation of someone being "soft" and "overly sympathetic" in the 1980s, when it was used by West Coast rappers such as Hugh E.M.C., Too Short, and E-40. Simp was referenced by Sir Mix-a-Lot in his 1992 hit "Baby Got Back" in the lyrics, "A lot of simps won't like this song". 2Pac also used the term in his song "If I Die 2Nite" on his 1995 album Me Against the World. In 1999, the term was used in the Three 6 Mafia song "Sippin' on Some Syrup" as an antonym for pimp; Too Short has described a "simp" as equivalent to "a knockoff pimp". The term has been expressed as a backronym for Sucker/Sucka Idolizing Mediocre Pussy, which according to Gizmodo Australia is "telling of its 20th century origins".
A definition of simp appeared on Urban Dictionary in 2003, and the word continued to be used by rappers into the 2010s, when it was adopted by members of the manosphere, incel, and MGTOW (Men Going Their Own Way) forums alongside similar derogatory terms such as cuck, beta, and white knight.The word became widely popular on TikTok in 2019, and soon also became popular on Twitch and Twitter. According to Google Trends, interest in the term doubled between late 2018 and late 2019.
The word has been used by some fan communities who call themselves "simps" for a celebrity figure. According to The Daily Dot, the term is often used ironically; similarly, Magdalene Taylor at MEL Magazine says the term is "used mostly as a joke". Nathan Grayson writes at Kotaku that it is "difficult to find breaks in the chain of the word's linguistic lineage".
Contemporary usage
In July 2020, the official Twitter account for Archie Comics said that it would permanently ban people from its YouTube channel for comments calling the comics' main character, Archie Andrews, a simp. The A.V. Club opined that, while it was "pretty safe to say that Archie Andrews is, quite simply, the simpiest of the simps," the Twitter post was likely an attempt at exploiting the Streisand effect for viral marketing. Contrary to the Twitter post, few, if any, comments on the Archie Comics YouTube channel accused the character of being a simp.
In August 2020, Australian politician Bill Shorten used the term on national television, saying on an ABC segment that Prime Minister Scott Morrison needed "to make sure he doesn't look like he's just a simp to Donald Trump".
In September 2020, users of Reddit created a pledge called "No Simp September", similar to No Nut November (a month-long abstention from masturbation). Participation in "No Simp September" required posters to abstain from upvoting women's photos, watching pornography, and "giving money to online sex workers", including "e-girls". In October, Mikael Thalen at The Daily Dot described Twitter users as "simping hard" over leaked photos of Hunter Biden.
A November 20 article in Vox about posting cringe on TikTok discussed the character of TikTok user Nate Varrone called "Mr. Simp Sexual", of the "biggest stars" of the genre. Varrone explained the character thus: He's from Michigan and he had a girlfriend named Melissa that he just wants back so fucking badly [...] He's just not in a good place right now, emotionally. I think he uses TikTok to fill the hole in his heart and find a new lover. The horniness this guy has, no human has ever felt that amount of horny in their entire life. It's like he has a curse. He thinks he has to hook up immediately or else he'll die.
In January 2021, Vogue reported on an "adoring" Instagram account of self-declared "simps" expressing affection toward then-Georgia Senate candidate Jon Ossoff. Ossoff won the election and was sworn in as a senator on January 20, 2021.
Reception
Upon achieving broad popularity, it began to be used more loosely. In April 2020, an opinion piece in Men's Health described the use of the term as "pretty messed up", and men who labeled others with the term as "entitled assholes", saying, "if you've ever complimented a woman, apparently you're a simp". Hayley Soen writes at The Tab that "the simp has come to take the place of the softboi", describing him as "a boy who is a romantic failure [...] definitely the type of boy you'd tell the girls is 'a little too nice, and "probably doesn't even have a lads' group chat"; Soen writes that the term is used "sometimes to describe even the bare minimum level of respect between a man and a woman".
According to the Evening Standard, while "the term could also have some value if it undermines a culture of stringing people along emotionally", it also had "potentially offensive connotations". In The New York Times, Ezra Marcus and Jonah Bromwich describe the term as a misogynist insult, one which "expresses discomfort with equality when it comes to gender, and offers a simple way to dismiss the people causing that discomfort".
Anna María of The Daily Dot writes that while the term is mostly used "ironically and without misogynistic undertones", "it doesn't take much to be called a simp" in some anti-feminist spaces, and that "everything from pining after a crush to actually respecting women could be considered simping". Taylor writes that the idea of the "simp" most often "seems to be a guy who simply treats women well, or just not like trash" and is "just another scapegoat for MGTOW misogyny".
Twitch ban
In May 2020, Kotaku reported that Twitch was "cracking down on" custom emotes using the word "simp", and had been "on a simp emote deleting spree" since late February. Twitch often requires its "partners" to submit custom emotes for approval prior to users being permitted to embed them; most of these emotes simply depicted a streamer or a fictional character holding up a sign with "SIMP" written on it, or were rasterizations of the text of the word itself. By December 2020, the word was described as a "favorite in the Twitch community" by The Verge.
Twitch announced in December 2020 that administrative action would be taken against the accounts of streamers and commentators who used the word, along with "incel" and "virgin", saying that those words were offensive; Twitch COO Sara Clemens said during a "town hall" live-stream that, while use of the words would be permitted under approved circumstances, Twitch would be "proactively denying" custom emotes that included the words. This ban was part of a broader expansion of Twitch's list of forbidden content; the policy, viewable on Twitch's website, also prohibited posting that "expresses inferiority" based on "moral deficiencies". At the time of the announcement, the policy was planned to take effect on January 22, 2021.
Reception to the announcement and proposed policy changes was largely negative; Bryan Rolli at The Daily Dot wrote that Twitch would "probably have a hell of a time enforcing the 'simp' ban", and Gizmodo said sarcastically that "actual simps and virgins [were] still welcome" on the streaming site. Screen Rant said that a blanket ban on "simp", "incel" and "virgin" contrasted unfavorably with a "context is needed" policy on the much more offensive racial slur "nigger". According to Ars Technica, Twitch had an "inconsistent history in responding to reports of problematic behavior".
In interviews with Kotaku, people affected by the ban described their channels' use of the term as mostly benign—one streamer said it was "mostly banter and, in some cases, a compliment". Another streamer, while acknowledging that the word was sometimes used to describe "quite creepy" behavior, said her use of a "simp" emote was "mainly just a joke within my community".
See also
List of Generation Z slang
Reply guy
Beta male
Nice guy
Soy boy
References
External links
1900s neologisms
1980s slang
1990s slang
2010s slang
2019 in Internet culture
2020s slang
African-American slang
Celebrity fandom
Hip-hop phrases
Human sexuality
Internet slang
Interpersonal attraction
Manosphere
Pejorative terms for people | Simp | [
"Biology"
] | 2,062 | [
"Human sexuality",
"Behavior",
"Sexuality",
"Human behavior"
] |
66,127,387 | https://en.wikipedia.org/wiki/Blichfeldt%27s%20theorem | Blichfeldt's theorem is a mathematical theorem in the geometry of numbers, stating that whenever a bounded set in the Euclidean plane has area , it can be translated so that it includes at least points of the integer lattice. Equivalently, every bounded set of area contains a set of points whose coordinates all differ by integers.
This theorem can be generalized to other lattices and to higher dimensions, and can be interpreted as a continuous version of the pigeonhole principle. It is named after Danish-American mathematician Hans Frederick Blichfeldt, who published it in 1914. Some sources call it Blichfeldt's principle or Blichfeldt's lemma.
Statement and proof
The theorem can be stated most simply for points in the Euclidean plane, and for the integer lattice in the plane. For this version of the theorem, let be any measurable set, let denote its area, and round this number up to the next integer value, . Then Blichfeldt's theorem states that can be translated so that its translated copy contains at least points with integer coordinates.
The basic idea of the proof is to cut into pieces according to the squares of the integer lattice, and to translate each of those pieces by an integer amount so that it lies within the unit square having the origin as its lower right corner. This translation may cause some pieces of the unit square to be covered more than once, but if the combined area of the translated pieces is counted with multiplicity it remains unchanged, equal to . On the other hand, if the whole unit square were covered with multiplicity its area would be , less than . Therefore, some point of the unit square must be covered with multiplicity at least . A translation that takes to the origin will also take all of the points of that covered to integer points, which is what was required.
More generally, the theorem applies to -dimensional sets , with -dimensional volume , and to an arbitrary -dimensional lattice (a set of points in -dimensional space that do not all lie in any lower dimensional subspace, are separated from each other by some minimum distance, and can be combined by adding or subtracting their coordinates to produce other points in the same set). Just as the integer lattice divides the plane into squares, an arbitrary lattice divides its space into fundamental regions (called parallelotopes) with the property that any one of these regions can be translated onto any other of them by adding the coordinates of a unique lattice point. If is the -dimensional volume of one of parallelotopes, then Blichfeldt's theorem states that can be translated to include at least points of . The proof is as before: cut up by parallelotopes, translate the pieces by translation vectors in onto a single parallelotope without changing the total volume (counted with multiplicity), observe that there must be a point of multiplicity at least , and use a translation that takes to the origin.
Instead of asking for a translation for which there are lattice points, an equivalent form of the theorem states that itself contains a set of points, all of whose pairwise differences belong to the lattice. A strengthened version of the theorem applies to compact sets, and states that they can be translated to contain at least points of the lattice. This number of points differs from only when is an integer, for which it is larger by one.
Applications
Minkowski's theorem
Minkowski's theorem, proved earlier than Blichfeldt's work by Hermann Minkowski, states that any convex set in the plane that is centrally symmetric around the origin, with area greater than four (or a compact symmetric set with area equal to four) contains a nonzero integer point. More generally, for a -dimensional lattice whose fundamental parallelotopes have volume , any set centrally symmetric around the origin with volume greater than contains a nonzero lattice point.
Although Minkowski's original proof was different, Blichfeldt's theorem can be used in a simple proof of Minkowski's theorem. Let be any centrally symmetric set with volume greater than (meeting the conditions of Minkowski's theorem), and scale it down by a factor of two to obtain a set of volume greater than . By Blichfeldt's theorem, has two points and whose coordinatewise difference belongs to . Reversing the shrinking operation, and belong to . By symmetry also belongs to , and by convexity the midpoint of and belongs to . But this midpoint is , a nonzero point of .
Other applications
Many applications of Blichfeldt's theorem, like the application to Minkowski's theorem, involve finding a nonzero lattice point in a large-enough set, but one that is not convex. For the proof of Minkowski's theorem, the key relation between the sets and that makes the proof work is that all differences of pairs of points in belong to . However, for a set that is not convex, might have pairs of points whose difference does not belong to , making it unusable in this technique. One could instead find the largest centrally symmetric convex subset , and then apply Minkowski's theorem to , or equivalently apply Blichfeldt's theorem to . However, in many cases a given non-convex set has a subset that is larger than , whose pairwise differences belong to . When this is the case, the larger size of relative to leads to tighter bounds on how big needs to be sure of containing a lattice point.
For a centrally symmetric star domain, it is possible to use the calculus of variations to find the largest set whose pairwise differences belong to . Applications of this method include simultaneous Diophantine approximation, the problem of approximating a given set of irrational numbers by rational numbers that all have the same denominators.
Generalizations
Analogues of Blichfeldt's theorem have been proven for other sets of points than lattices, showing that large enough regions contain many points from these sets. These include a theorem for Fuchsian groups, lattice-like subsets of matrices, and for the sets of vertices of Archimedean tilings.
Other generalizations allow the set to be a measurable function, proving that its sum over some set of translated lattice points is at least as large as its integral, or replace the single set with a family of sets.
Computational complexity
A computational problem related to Blichfeldt's theorem has been shown to be complete for the PPP complexity class, and therefore unlikely to be solvable in polynomial time. The problem takes as input a set of integer vectors forming the basis of a -dimensional lattice , and a set of integer vectors, represented implicitly by a Boolean circuit for testing whether a given vector belongs to . It is required that the cardinality of , divided by the volume of the fundamental parallelotope of , is at least one, from which a discrete version of Blichfeldt's theorem implies that includes a pair of points whose difference belongs to . The task is to find either such a pair, or a point of that itself belongs to . The computational hardness of this task motivates the construction of a candidate for a collision-resistant cryptographic hash function.
See also
Dot planimeter, a device for estimating the area of a shape by counting the lattice points that it contains
Pick's theorem, a more precise relationship between area and lattice points covered by a polygon with lattice-point vertices
References
External links
Geometry of numbers
Theorems in geometry | Blichfeldt's theorem | [
"Mathematics"
] | 1,527 | [
"Geometry of numbers",
"Geometry",
"Theorems in geometry",
"Mathematical problems",
"Mathematical theorems",
"Number theory"
] |
66,127,654 | https://en.wikipedia.org/wiki/NED-19 | Trans-NED-19 is a drug which acts as a potent and selective antagonist of the endogenous calcium channel opener nicotinic acid adenine dinucleotide phosphate (NAADP), thereby reducing the normal NAADP-mediated calcium flux without blocking calcium channels directly. It is used in research into the functions of NAADP signalling inside many different cell types.
References
Beta-Carbolines
Phenylpiperazines
Tryptamines | NED-19 | [
"Chemistry"
] | 95 | [
"Pharmacology",
"Pharmacology stubs",
"Medicinal chemistry stubs"
] |
66,128,381 | https://en.wikipedia.org/wiki/Reinforcement%20%28composite%29 | In materials science, reinforcement is a constituent of a composite material which increases the composite's stiffness and tensile strength.
Function
Following are the functions of the reinforcement in a composite:
It increases the mechanical properties of the composite.
It provides strength and stiffness to the composite in one direction as reinforcement carries the load along the length of the fibre.
Fiber reinforcement
Crack propagation is prevented considerably, while rigidity is added normally by the reinforcement. Thin fibers can have very high strength, and they can increase substantially the overall properties of the composite provided they are linked mechanically to the matrix.
Fiber-reinforced composites have two types, and they are short fibre-reinforced and continuous fiber-reinforced. Sheet moulding and compression moulding operations usually use the long and short fibers. These are available in the form of chips, flakes and random mate (which also can be produced from a continuous fibre laid randomly till the desired thickness of the laminate/ply is attained).
A laminated or layered structure is usually constituted in continuous reinforced materials. The continuous and woven fiber styles are usually available in various forms, being pre-impregnated with the given matrix (resin), dry, uni-directional tapes of different widths, plain weave, harness satins, braided, and stitched.
Reinforcement uses some of the common fibers such as carbon fibres, cellulose (wood/paper fibre and straw), glass fibers and high strength polymers, for example, aramid. For high-temperature applications, Silicon carbide fibers are used.
Particle reinforcement
Particle reinforcement adds a similar effect to precipitation hardening in metals and ceramics. Large particles prevent dislocation movement and crack propagation as well as contribute to the composite's Young's Modulus. In general, particle reinforcement effect on Young's Modulus lies between values predicted by
as a lower bound and
as an upper bound.
Therefore, it can be expressed as a linear combination of contribution from the matrix and some weighted contribution from the particles.
Where Kc is an experimentally derived constant between 0 and 1. This range of values for Kc reflects that particle reinforced composites are not characterized by the isostrain condition.
Similarly, the tensile strength can be modeled in an equation of similar construction where Ks is a similarly bounded constant not necessarily of the same value of Kc
The true value of Kc and Ks vary based on factors including particle shape, particle distribution, and particle/matrix interface. Knowing these parameters, the mechanical properties can be modeled based on effects from grain boundary strengthening, dislocation strengthening, and Orowan strengthening.
The most common particle reinforced composite is concrete, which is a mixture of gravel and sand usually strengthened by addition of small rocks or sand. Metals are often reinforced with ceramics to increase strength at the cost of ductility. Finally polymers and rubber are often reinforced with carbon black, commonly used in auto tires.
References
Composite materials | Reinforcement (composite) | [
"Physics"
] | 592 | [
"Materials",
"Composite materials",
"Matter"
] |
66,128,671 | https://en.wikipedia.org/wiki/Biphasic%20calcium%20sulfate | Biphasic calcium sulfate is a granulated powder composed of calcium sulfate hydrate (CaSO4•2H2O) and calcium sulfate hemihydrate (CaSO4•H2O). It is used primarily as a bone grafting material in dental augmentation procedures such as socket grafting, lateral augmentation, sinus lift, cyst enucleation and more.
The clinical use of calcium sulfate has been documented for over a century as a bone grafting material, and was first recorded in Germany in 1892 when it was used to fill bone defects in patients with tuberculous cavities. Calcium sulfate has not been widely available for dental uses due to its instability in the presence of blood and saliva. Studies have shown that it is a delivery vehicle for growth factors and that the calcium in calcium sulfate stimulates osteoblasts.
Biphasic calcium sulfate was invented in 2010 and has the same chemical structure as calcium sulfate. It is a biocompatible material that slowly dissolves as new bone is formed, over a period of 3 to 6 months. It is also used as a composite graft, for longer term use. The unique structure of biphasic calcium sulfate allows it to be moldable and stable in the presence of blood and saliva, making it effective for use in dental augmentation procedures. Biphasic calcium sulfate is well accepted by the body, and acts as a scaffold allowing for optimal bone growth as it slowly reabsorbs. Soft tissue is prevented from growing into the defect, but blood vessels are able to grow (angiogenesis), which brings osteogenic cells to the area.
References
Calcium compounds
Sulfates
21st-century inventions | Biphasic calcium sulfate | [
"Chemistry"
] | 352 | [
"Sulfates",
"Salts"
] |
66,129,222 | https://en.wikipedia.org/wiki/Fersah | Fersah was an Ottoman unit of distance.
It was based on the distance covered by a horse in normal gait per hour. Its modern definition (parasang) is . There were other definitions. According to Islam Encyclopaedia, ıt was sometimes or .
References
Ottoman units of measurement
Units of length | Fersah | [
"Mathematics"
] | 68 | [
"Quantity",
"Units of measurement",
"Units of length"
] |
66,129,362 | https://en.wikipedia.org/wiki/Merhale | Merhale was an Ottoman unit of length.
8 fersahs were equal to 1 merhale. Fersah was based on the distance covered by a horse in normal gait per hour. Exact definition was 5685 meters.
So 1 merhale can be converted to meters.
References
Ottoman units of measurement
Customary units of measurement | Merhale | [
"Mathematics"
] | 67 | [
"Quantity",
"Customary units of measurement",
"Units of measurement"
] |
66,129,411 | https://en.wikipedia.org/wiki/Identifier%20for%20Advertisers | Apple's Identifier for Advertisers (IDFA) is a unique random device identifier Apple generates and assigns to every device. It is intended to be used by advertisers to deliver personalized ads and attribute ad interactions for ad retargeting. Users can opt-out of IDFA via the "Limit Ad Tracking" (LAT) setting (and an estimated 20% do).
Starting in iOS 14.5, iPadOS 14.5, and tvOS 14.5, users are prompted to decide whether to opt-in or out of IDFA sharing before apps can query it. This choice can be altered in Settings. In May, 2021, Verizon-owned advertisement analytics company Flurry Analytics reported that 96% of US users opted out of IDFA sharing.
History
Limit Ad Tracking
In iOS 10, Apple introduced "Limit Ad Tracking" setting for users who do not wish to be tracked by advertising networks. If the setting is enabled the system returns a default all-zero id for that device. As of December 2020, it's estimated that approximately 20% of users turn on this setting.
App Tracking Transparency
On September 3, 2020, Apple announced plans to restrict access to IDFA and require websites and apps to obtain an explicit permission from users before being granted access to IDFA. Since January 2021, users and developers could test this change by installing iOS 14 beta release.
In July 2020, Facebook stated that this transparency requirement would likely hurt their advertising targeting. Facebook said that these changes "may render [their tracking] so ineffective on iOS 14 that it may not make sense to offer it on iOS 14" and Facebook apps on iOS 14, including Facebook, WhatsApp, Instagram, Messenger, and others will not collect IDFA on iOS 14.
In early September, Apple postponed these restrictions until early 2021.
In December 2020, the Mozilla Foundation expressed support for Apple restricting access to IDFA and asked users to sign a petition to "help strengthen [Apple's] resolve to protect consumer privacy".
On December 15, 2020, Facebook launched a "Speak Up for Small Businesses" campaign against Apple. In this campaign, Facebook purchased full-page advertisements in newspapers and created a web page claiming Facebook tries to help small businesses. This campaign became controversial even within Facebook itself, because some employees thought Facebook was "trying to justify doing a bad thing by hiding behind people with a sympathetic message."
On January 27, 2021, Google announced that when the new requirement goes into effect, a "handful" of Google apps will stop collecting IDFAs (and thus the apps will avoid displaying a prompt for allowing tracking user activity).
In February 2021, Post-IDFA alliance surveyed 600 customers and noted that 38.5% of them said they plan to allow tracking by tapping "yes" in the App Tracking Transparency prompt.
On March 18, 2021, Facebook changed its stance. Facebook CEO, Mark Zuckerberg, claimed that these changes might even strengthen Facebook's position "if Apple’s changes encourage more businesses to conduct more commerce on [Facebook's] platforms by making it harder for them to use their data in order to find the customers that would want to use their products outside of [Facebook's] platforms".
On April 1, 2021, the Apple App Store started rejecting apps which used Adjust SDK and attempted to circumvent App Tracking Transparency rules via device fingerprinting (collecting device and usage data to create a unique identifier in order to track the user). On April 2, Adjust removed the offending code and app developers might pass App Store review after updating to the new Adjust SDK version.
In May, 2021, Verizon-owned advertisement analytics company Flurry reported that 96% of US users opted out of IDFA sharing. Approximately 3% of US users restricted IDFA sharing system-wide.
Unconditional restrictions on Advertising ID sharing
Apple unconditionally disables Apple IDFA sharing for some Apple ID accounts. In this case apps do not display permission prompt and the Settings entry "Allow Apps to Request to Track" is grayed out. Restrictions apply if the Apple ID is:
classified as a child account (for example, user's calculated age is less than 18 years old), or
managed by an educational institution or organization which limits tracking, or
less than 3 days old.
Circumvention attempts
In March 2021, the China Advertising Association announced that it was backing a device fingerprinting system as a work-around for Apple's new IDFA restrictions called CAID. Companies testing the system reportedly include ByteDance and Tencent.
See also
Advertising ID
Ad-ID
References
Apple Inc. services
Adware
Mobile technology
Tracking
Mass surveillance
Privacy | Identifier for Advertisers | [
"Technology"
] | 970 | [
"Tracking",
"Wireless locating",
"nan"
] |
66,130,161 | https://en.wikipedia.org/wiki/Push%20feed%20and%20controlled%20feed | Push feed and controlled feed (or controlled round feed) are two main types of mechanisms used in firearms to describe how the bolt drives the cartridge into the chamber and extracts the spent casing after firing.
The push feed system does not grip the base of the cartridge before the cartridge has been fully entered into the chamber, and therefore under normal operation requires the cartridge to be fully chambered before it can be extracted.
The controlled feed system grips the base of the cartridge with the extractor claw before the cartridge is stripped from the magazine, and therefore makes it possible to extract the cartridge before it has been fully chambered.
The better of the two systems has been debated for over 50 years, with both systems having their own strengths and weaknesses. Some prefer the controlled round feed for hunting dangerous game, while others state that either of the systems can be reliable or unreliable, depending for example on the quality of the rifle and maintenance. There has been a trend that newer rifle models tend to have a push feed mechanism, while almost every modern semi-auto pistol has a controlled feed mechanism. A push feed system in most cases is cheaper to manufacture than the more complex controlled feed mechanism.
History
The first rifle with a controlled feeding mechanism was the M1885 Remington–Lee which first appeared in 1879. Lee applied for a patent, around the same time as Mauser applied for a patent on the same feature, DE51241 and US476290, which was introduced on the Mauser Model 1893.
Discussion
Double feed
The main disadvantage with a push feed system is the possibility for a double feed malfunction if the bolt is not fully closed when chambering a round, followed with pulling the bolt back to strip another round from the magazine, resulting in one chambered and one partially chambered round. A double feed in itself is somewhat uncommon as an independent malfunction, but it often manifests itself as a consequence of other firearm malfunctions. A controlled feed mechanism should in theory not be able to double feed if it is set up correctly. In practice, however, double feed malfunctions sometimes also occur with controlled feed mechanisms.
Safety during case rupture
Push feed mechanisms in theory give the opportunity to design a safer firearm when it comes to a case rupture (for example due to overpressure or excessive headspace) since the bolt head can be designed with a smaller extractor claw which in turn gives the rest of the bolt head a bigger surface area and therefore better support for the cartridge during firing.
Ejector types
Most push feed mechanisms use a spring loaded plunger type of ejector situated at the breech face, and this system ejects the spent casing as soon as the case mouth clears the ejection port. Most controlled feed mechanisms use a fixed mechanical ejector attached to the receiver, which results in the bolt having to be pulled all or almost all the way back to eject the spent casing. This can give a marginally quicker cyclic rate with a push feed action, since the bolt no longer has to be repeated as far or all the way back.
Hand feeding directly into the chamber
Most controlled feed mechanisms should not be closed on a chamber already containing a cartridge (similar to how a push feed mechanism would operate). On the short term, this can result in difficulties with closing the bolt, and therefore also difficulties with extracting the unfired cartridge from the chamber. On the long term, the extractor may be significantly worn out or damaged, since the extractor claw on most controlled feed mechanisms has not been designed to slip over the rim of a chambered round. As a result, controlled feed mechanisms should always be fed with cartridges which first have been filled into the magazine.
One notable exception to this principle is the line of rifles based on the Ruger M77. This includes the Ruger M77 Mark II and Ruger Hawkeye rifles. While possessing a claw extractor and operating on the controlled feed principle, the M77 rifles have a "Mauser-type" bolt which is also designed to be able to "jump" over a round already in the chamber. This means that it is possible to feed a round directly into the chamber, as is possible with push-feed designs.
Push feed mechanisms on the other hand have an extractor which is designed to move around the rim of an already chambered round, and the cartridges can therefore either be fed via the magazine or hand fed directly into the chamber (sometimes called "single loading").
Example firearms
Using controlled feed
Mauser M98
Kalashnikov rifle
Winchester Model 70 (pre-1964, post-1992)
Ruger M77 line
Sako 85
M1911 pistol
Using push feed
Mosin–Nagant
Weatherby Mark V
Colt AR-15
Winchester Model 70 (1964-1992)
Remington 700
Sako 75
Ruger American Rifle
See also
Extractor/Ejector
Pawl-type feeding mechanism, used on many belt fed firearms (such as MG 42, FN MAG, FN Minimi, etc.)
References
External links
How Does It Work: Push Feed vs Controlled Feed Forgotten Weapons
Firearm components | Push feed and controlled feed | [
"Technology"
] | 1,048 | [
"Firearm components",
"Components"
] |
76,321,982 | https://en.wikipedia.org/wiki/Scaritoxin | Scaritoxin, a potent toxic substance, is a ciguatoxin with molecular formula C60H84O16. Scaritoxin is also referred to as ciguaotoxin 4A, CTX4A. Like other ciguatoxins, CTX4A is produced by dinoflagellate Gambierdiscus toxicus and isolated from poisonous fish.
The name of scaritoxin is derived from the poisonous fish Scarus gibus, which is now known as the Chlorurus gibbus family of the Scaridae. Namely, ciguatoxins accumulate in various fish species via the food chain as a result of biotransformation of the precursor gambiertoxins produced by Gambierdiscus toxicus. Since CTX4A was identified in Gambierdiscus toxicus and in parrotfish, the first link in the food chain, it was concluded that Gambierdiscus toxicus is the biogenetic origin of ciguatera toxins found in fish. Ciguatoxins, CTX-group toxins, generally accumulate in the skin, head, viscera, and roe of big reef fish
Ingestion of these fish with accumulated CTX-group toxins, marine biotoxins, results in ciguatera fish poisoning (CFP). Poisoning with scaritoxin, however, is not well described.
Ciguatera poisoning
Ciguatera fish poisoning (CFP) is a clinical syndrome caused by eating fish containing accumulated ciguatoxins (CTXs), marine biotoxins, due to feeding on toxic microalgae. Traditional endemic regions for ciguatoxic fish include areas in the Caribbean sea and the Pacific and Indians oceans, but autochthonous outbreaks have also been reported in Europe. The accumulated ciguatoxins remain stable at various temperatures, meaning they are not eliminated through cooking or freezing fish. Additionally, these toxins lack color, odor, and flavor, making it impossible to detect them by taste or smell.
Fatality risks from CFP arise from cardio-respiratory failure. CFP stands as the most prevalent marine biotoxin food poisoning globally, affecting an estimated 10.000 to 50.000 individuals annually. Associated to ciguatera fish poisoning is primarily the consumption of large predator fish, which accumulate CTX-group toxins by preying on smaller contaminated coral reef fish. However, ciguatoxins rarely accumulate in fish at levels that are lethal to humans, so CFP comes along with a low mortality rate, but a significant high morbidity rate.
Metabolism
Generally, ciguatoxins produced by the causative Gambierdiscus toxicus exist in multiple forms as a result of biotransformation by passage through the food web. Through the biotransformation and the acid catalyzed Spiro isomerization of gambiertoxin, they arise in the fish. It is said that the toxins undergo varying extents of biotransformation, but very little is known about the specifics. The different digestive strategies among the herbivores and carnivores are possibly influencing the nature of the toxin biotransformation via the marine food chain.
Symptoms and side effects
Symptoms of ciguatera fish poisoning in humans include several effects which are mainly gastrointestinal, cardiovascular, and neurological. The symptoms of acute ciguatera fish poisoning can already start 30 minutes after eating contaminated fish. However, in milder cases the first symptoms arise 24 to 48 hours later. The initial symptoms may include itching, tingling, and numbness of the lips, tongue, hands, throat and/or feet. During the first 6 to 17 hours gastrointestinal symptoms like abdominal cramps, nausea, vomiting, diarrhea, and/or a red skin rash (pruritus), can occur. Accompanying these gastrointestinal symptoms, neurological symptoms become prominent 3 to 48 hours after eating of the contaminated fish. Moreover, chills, hot and cold temperature reversal, generalized weakness, restlessness, dizziness, wheezing, blurred vision, abnormal sensitivity to light (photophobia), muscle aches (myalgias), and joint pain (arthralgias) can also occur.
The severe symptoms of ciguatera fish poisoning disappear generally disappear after a few days, but the neurological symptoms can remain present for months. Abnormally low blood pressure upon standing from a seated position (orthostatic hypotension) is a symptom of CFP that can be experienced. Severe instances may proceed quickly to muscle paralysis and dyspnoea, which are breathing difficulties. Acute cases that progress to life-threatening consequences (irregularly slow heartbeat, respiratory arrest, convulsions, or coma) happen within 24 hours.
Poisoning with scaritoxin actually emerges in two stages. The first set of symptoms resemble typical ciguatera poisoning as described. The second stage, developing five to ten days after the initial symptoms, start with failure of equilibration and marked locomotor ataxia. There is no known antidote, medication or treatment for scaritoxin poisoning. Medical care towards CFP-patients consists of supportive care, varying with the symptoms a patient shows.
Structure
Scaritoxin is a rather large lipid soluble polycyclic polyether toxin with molecular formula C60H84O16. The compound contains 31 defined stereo-centres, one E/Z centre and its optical activity is unspecified. The structure contains 13 rings fused by ether linkages, which make the structure of scaritoxin into a rigid ladder like-structure. Because of its rigidity the structure is known not to be affected by heat and acidic or basic conditions.
Mechanism of action
Scaritoxin, recognized as a potent toxin, induces diverse effects across various biological systems through its interaction with specific cellular receptors or ion channels, thereby initiating notable physiological alterations. A guinea-pig vas deferens investigation characterizes a pronounced excitatory impact of scaritoxin, indicative of its engagement with receptors or ion channels within smooth muscle cells, precipitating muscle contraction and heightened excitability. Additionally, investigations into the autonomic effects of scaritoxin on animals suggest potential interactions with receptors or ion channels within the autonomic nervous system, utilizing influence over parameters such as heart rate, cardiac function, and other autonomic-controlled processes. Alternative mechanisms, including a hypothesized digitalis-like effect due to the cyclopentanone ring present in the scaritoxin molecule, validates consideration.
Notably, a separate inquiry observed that a medication employed for arrhythmia prevention could diminish scaritoxin-induced cardiac detriment, implying a tendency of scaritoxin to induce arrhythmias or other harmful cardiac manifestations, possibly through modulation of specific components within the cardiac electrical conduction system.
The mechanism of action for scaritoxin is not clearly defined, but knowing it is a ciguatoxin it is likely to follow the same mechanism. It is said that the toxin bind and modulate the activity of cell membrane voltage-gated sodium channels. Ciguatoxins bind on the alpha subunit at site 5, this induces the opening of the channels at resting membrane potential. This activation of voltage-gated sodium channels in cell membranes thus increases the sodium ion permeability, which causes membrane depolarization and thereby spontaneous action potentials. As a result the neuronal tissue has decreased conduction velocity and neurotransmission.
Toxicity
Since the feeding history of fish and the population of alga causing ciguatera fish poisoning, the toxicity of individual fish is very unpredictable. The fish that carry scaritoxin in their flesh do not seem to be harmed by it. Testing for scaritoxin in these fish is not a standard practice and it is really difficult to prevent scaritoxin poisoning since toxin is not harmed by heat, acid or basic conditions and cannot be detected with taste or smell.
The lethal dose fifty () of scaritoxin administered intraperitoneally in mice was determined to be 50 micrograms per kilogram. This denotes a pronounced toxicity of scaritoxin towards mice, presumably due to its disruptive effects on vital physiological mechanisms or harmful impacts on organ systems. This translates for an average human of around 70 kilograms to 3.5 milligrams, hence this shows that a small amount can potentially cause significant harm to humans. However, directly translation of the results from mice to humans is not a reliable source to draw specific conclusions from about the toxicity for humans.
References
Toxins | Scaritoxin | [
"Chemistry",
"Environmental_science"
] | 1,785 | [
"Toxins",
"Polyether toxins",
"Toxicology",
"Toxins by chemical classification"
] |
76,322,288 | https://en.wikipedia.org/wiki/Belly%20rub | A belly rub or tummy rub is the act of gently touching a dog's stomach area. Numerous dogs enjoy belly rubbing, but not all of them. When a dog rolls on their back, it may be an indication that the dog wants a belly rub, however it is not always the case. A dog’s stomach is an immensely vulnerable part of their body. Some body language that indicates that a dog wants a belly rub includes vocalization, tail waggling, open (or squinty) eyes, relaxed and open mouth, while their body is wiggly and loose. If the dog kicks their leg or both legs during belly rub, it is completely normal, and the phenomenon itself is called a scratch reflex.
See also
Emotion in dogs
References
Dogs | Belly rub | [
"Biology"
] | 156 | [
"Behavioural sciences",
"Ethology",
"Behavior"
] |
76,322,842 | https://en.wikipedia.org/wiki/C13H21NO4 | {{DISPLAYTITLE:C13H21NO4}}
The molecular formula C13H21NO4 may refer to:
Meteloidine
2,3,4,5-Tetramethoxyamphetamine | C13H21NO4 | [
"Chemistry"
] | 49 | [
"Isomerism",
"Set index articles on molecular formulas"
] |
76,323,410 | https://en.wikipedia.org/wiki/List%20of%20precious%20commemorative%20coins%20of%20Ukraine | This is a list of Commemorative and Jubilee coins issued by the Ukrainian government.
Since 1996, the National Bank of Ukraine has been issuing commemorative and commemorative coins made of precious metals. According to the material, they consist of silver, gold or bimetal, which consists of silver and gold.
A total of 433 commemorative and commemorative coins were issued during the independence of Ukraine.
Number of coins
Silver coins
Ukrainian karbovanets coins of 1996
Coins of 2, 5, 10, 20, 50, 100, 125, 200, 250, 500 hryvnias
1996-1999 years
2000-2004 years
2005-2009 years
2010-2014 years
2015-2019 years
2020-2024 years
Bimetallic coins of precious metals
Gold coins
Series of coins
2000 Years of Christmas
Ancient monuments of Ukraine
Airplanes of Ukraine
Ancient cities of Ukraine
Architectural monuments of Ukraine
Ukraine’s Armed Forces
On the edge of Millenniums
Children's Zodiac
Eastern calendar
Fauna in cultural monuments of Ukraine
Famous families of Ukraine
Flora and fauna
Folk crafts of Ukraine
Folk Musical Instruments
Heroes of Cossack Age
Hero-cities of Ukraine
Hetmans' capital cities
Higher educational establishments of Ukraine
Maritime history of Ukraine
Monuments of ancient cultures of Ukraine
My Immortal Ukraine
Oblasts of Ukraine
Outstanding Personalities of Ukraine
Other coins
Points of interest of ancient cultures of Ukraine
Princes of Ukraine
Rebirth of Christian spirituality in Ukraine
Rebirth of Ukrainian statehood
Ritual Festivals of Ukraine
Spiritual Treasures of Ukraine
Sports
The Smallest Golden Coin
To the heroes of the Maidan
Cosmic Ukraine
Ukrainian heritage
Ukrainian state
World War II
Signs of the zodiac
See also
List of commemorative coins of Ukraine
External links
Commemorative and Jubilee Coins by The National Bank of Ukraine
Монети України. XІХ видання, Київ, 2024, Видання 19-те, перероблене та доповнене, формат 165х235, 464 стр., UA, ISBN 978-617-95147-4-6, Максим Загреба.
References
Glassmaking companies
Commemorative coins
Ukraine
Commemorative coins | List of precious commemorative coins of Ukraine | [
"Materials_science",
"Engineering"
] | 449 | [
"Glass engineering and science",
"Glassmaking companies",
"Engineering companies"
] |
76,325,147 | https://en.wikipedia.org/wiki/Chung-Yun%20Hse | Chung-Yun Hse (February 19, 1935 – November 12, 2021) was a Taiwanese American research scientist in wood utilization, who was an elected fellow (FIAWS) of the International Academy of Wood Science. He served at the USDA Forest Service Southern Research Station in Pineville, Louisiana from 1967 through 2019.
Education and research career
Originally from Taiwan, Chung-Yun Hse obtained a master's degree in forest soil chemistry from Louisiana State University. In 1972, he received a PhD in wood science and technology from the University of Washington.
In 1963, a new research program was initiated at the Southern Forest Experiment Station in Pineville, Louisiana to address the lack of forest product utilization research in the Southern United States. A key component of that research was development of wood adhesives to bind resinous wood from southern pines for plywood production, and Hse was selected to address that area of research.
During his 50-year career with the US Forest Service, Hse produced three US patents, authored or coauthored more than 150 research publications, and hosted more than 40 scientists from research institutes and universities around the world. He retired in January 2020 as emeritus scientist.
Awards
Awards from USDA Forest Service:
1992 – Award for Technology Transfer from Station Director
2001 – Award for International Programs from Station Director
2003 – Award for Sustained Excellence in Science from Station Director
2004 – Honor Award for Distinguished Science from Forest Service Chief
National and international recognition:
1994 – Award for Excellence in International Forestry Cooperation and Exchange from Chinese Ministry of Forestry
1998 – Fellow of the International Academy of Wood Science
2001 – China's Friendship Award in appreciation of enthusiastic support for China's construction and friendly cooperation
2008 – Fred W. Gottschalk Memorial Award for outstanding service to the Forest Products Society
2012 – Distinguished Service Award Society of Wood Science and Technology
2013 – The International Scientific and Technological Cooperation Award of The People's Republic of China
Patents
Method of bonding particle board and the like using polyisocyanate/phenolic adhesive (1980).
Process for detoxification of CCA-treated wood (2007).
Process for rapid microwave-enhanced detoxification of CCA-treated wood (2011).
References
1935 births
2021 deaths
American people of Taiwanese descent
University of Washington alumni
Louisiana State University alumni
Wood scientists
20th-century American inventors
21st-century American inventors
Fellows of the International Academy of Wood Science
American technology writers | Chung-Yun Hse | [
"Materials_science"
] | 487 | [
"Wood sciences",
"Wood scientists"
] |
76,325,708 | https://en.wikipedia.org/wiki/Symmetries%20of%20Culture%3A%20Theory%20and%20Practice%20of%20Plane%20Pattern%20Analysis | Symmetries of Culture: Theory and Practice of Plane Pattern Analysis is a book by anthropologist Dorothy K. Washburn and mathematician Donald W. Crowe published in 1988 by the University of Washington Press. The book is about the identification of patterns on cultural objects.
Structure and topics
The book is divided into seven chapters. Chapter 1 reviews the historical application of symmetry analysis to the discovery and enumeration of patterns in the plane, otherwise known as tessellations or tilings, and the application of geometry to design and the decorative arts.
Chapters 2 to 6 describe how to identify and classify patterns on cultural objects such as ceramics, textiles and surface designs. Chapter 2 establishes the mathematical tools required to perform the symmetry analysis of patterns. Chapter 3 introduces the concept of color symmetry, for two-colored and multicolored patterns. Chapters 4 and 5 describe the one-dimensional (frieze) designs and the two-dimensional (plane) designs respectively; flow charts are used to help the reader to identify patterns. Chapter 6 describes finite designs, for example circular designs, which are those without translations or glide refections. Chapter 7 discusses problems that may arise in symmetry classification, for example pattern irregularities.
The benefit of the flow charts is that they allow the reader to analyse the design of any cultural object in order to assign it to a specific pattern. The number of distinct patterns in one or two dimensions, with one or two colors, is shown in the table.
The book, which was 10 years in development, has over 500 illustrations, and includes a mathematical appendix, a 270-entry bibliography, and an index.
Audience
The authors describe their book as a "handbook for the non-mathematician" of the theory and practice of plane pattern analysis.
Reviewers of the book identified the audience for the book in various ways. Roger Neich writing in Man said "[The authors'] aim is to make symmetry analysis accessible to all researchers, regardless of any mathematical training, and in this aim they succeed admirably, provided the reader is prepared to invest some considerable effort."
Doris Schattschneider writing in The American Mathematical Monthly commented: "[The book] was written for archaeologists, anthropologists, and art historians, but the authors have taken care in their presentation of the geometry of symmetry and color symmetry analysis." H.C. Williams reviewing the book for The Mathematical Gazette said: "This interesting book is written by a mathematician and an anthropologist and is aimed primarily at the non-mathematician. That said, it is well worth the attention of mathematicians, particularly teachers, who have an interest in pattern."
Reception
Contemporary reviews of the book were mostly positive. The book was reviewed by journals in the fields of anthropology, archaeology, the arts, and mathematics.
Mary Frame in African Arts said: "a solid and attractive book that takes the reader in logical stages toward an understanding of the symmetrical basis of pattern repeats." [...] "I believe that Symmetries of Culture is a landmark work that will furnish the impetus and method for many studies in this fertile area." Owen Lindauer in American Anthropologist commented: "Question-answer flowcharts enable the reader to correctly classify designs using a standard notation. The book is extensively illustrated with carvings, textiles, basketry, tiles, and pottery, which are used as examples of various symmetry patterns."
Dwight W. Read in Antiquity: "Symmetries of Culture is an impressive book - both in
terms of its physical appearance and its content. [...] will undoubtedly become the major reference on the analysis of patterns in terms of symmetry properties." Jon Muller writing in American Antiquity: " ... a fine book that achieves its goals in a straight-forward and clear fashion. It presents a set of methods that can be applied consistently and usefully in looking at symmetrical plane designs." and Roger Neich in Man: "... wide use of this book will certainly contribute to a great improvement in the systematic study of material culture."
Criticism
The reviewer in African Arts pointed out the existence of cultural patterns, such as in ancient Peruvian art, that are not included in the crystallographic symmetry approach to patterns used in the book. This criticism was echoed by the reviewer in American Antiquity who had some reservations about the potential dangers of limiting design analysis to certain convenient classes of design.
George Kubler, an art historian writing in Winterthur Portfolio criticised the book: "The authors' present method is non-historical. The objects illustrated are mostly undatable, and nowhere is concern shown for their seriation or place in time." Kubler criticises the authors' entire approach as being non-historical, because it analyses each object individually rather than considering them in chronological order.
Influence
In 2021 the book was praised by Palaguta and Starkova in Terra Artis. Art and Design. In their review, they stated that the problem of creating a basis for systematizing patterns on the principles of symmetry was solved in Symmetries of Culture. They give three reasons for continuing to value the book: firstly, despite the passage of time, the book is still valid and useful; secondly, since the release of the book, the authors have done a great deal to attract new workers into the field; and thirdly, in recent years, interdisciplinary research on symmetry and ornamentation has increased, and the interest in this topic has grown among both anthropologists and art historians, which greatly broadens the readership of the book.
Editions
The hardback original Symmetries of Culture: Theory and Practice of Plane Pattern Analysis was published in 1988.
A paperback reprint was published in 1992.
In 2020 a paperback reprint of the full text was published by Dover.
References
External links
at the Internet Archive
Patterns
Symmetry
Mathematics and art
1988 non-fiction books | Symmetries of Culture: Theory and Practice of Plane Pattern Analysis | [
"Physics",
"Mathematics"
] | 1,178 | [
"Geometry",
"Symmetry"
] |
76,328,505 | https://en.wikipedia.org/wiki/N1-Acetyl-5-methoxykynuramine | N1-Acetyl-5-methoxykynuramine (AMK) is a metabolite of melatonin that could improve memory by acting on the melatonin receptors. AMK is produced from the metabolization of melatonin by the kynuramine pathway in the brain. It significantly increased the phosphorylation of both ERK and CREB in the hippocampus. It also helps scavenge free radicals. AMK is highly reactive towards dioxygen (O2) radicals because of AMK's N2-amino group.
References
Melatonin
Methoxy compounds
Anilines
Metabolism | N1-Acetyl-5-methoxykynuramine | [
"Chemistry",
"Biology"
] | 139 | [
"Biotechnology stubs",
"Biochemistry stubs",
"Cellular processes",
"Biochemistry",
"Metabolism"
] |
76,331,749 | https://en.wikipedia.org/wiki/Human%20betaretrovirus | Human betaretrovirus (HBRV), also known as Human mammary tumor virus, or Mouse mammary tumor-like virus is the human homologue of the Mouse mammary tumor virus (MMTV). The nomenclature for Human betaretrovirus was introduced following characterization of infection in patient with autoimmune liver disease suggesting the virus is not solely found in mice nor exclusively implicated in the development of neoplastic disease. Evidence of HBRV has been documented in humans dating back at least 4500 years ago, and it stands as the only identified exogenous betaretrovirus affecting humans to date.
The existence of this virus was suspected for decades. Nucleotide sequences identifying a whole proviral betarerovirus were first reported in human breast cancer in 2001 and lymphoid tissues of patients with autoimmune liver disease in 2003. Viral particles were isolated several years later.
Virology
The HBRV encodes an approximately 9 kilobase single-stranded RNA genome, and shares significant virological similarities with MMTV. The human and mouse betaretrovirus are difficult to distinguish genetically, and structural proteins share 93% to 99% amino acid sequence similarity with each other and less than 35% with other betaretroviruses and the human endogenous betaretroviruses (HERV-K). By electron microscopy, both human betaretrovirus and MMTV have comparable morphological features and form 80-100 nm spherical and pleomorphic structures with eccentric nucleocapsid cores.
Previously, these betaretroviruses were considered simple retroviruses encoding gag, pol and env genes but are now considered complex with the characterization of the regulator of MMTV expression (Rem) protein that acts as a nuclear export of the unspliced RNA. The HBRV genome encodes five possible open reading frames (ORFs) that correspond with the Gag, protease (Pro), polymerase (Pol), envelope (Env), regulator of MMTV expression (Rem) and superantigen (Sag) proteins found in MMTV. The viral superantigen is the most variable region within the betaretrovirus genome. The viral superantigen mechanism is required to stimulate lymphocyte proliferation and enable viral replication within dividing cells; demonstration of superantigen activity is used to demonstrate MMTV infection in mice.
Transmission
Cross-species transmission
The similarity of MMTV with HBRV suggests a zoonosis from mice to humans. The discovery of HBRV in humans, dating back thousands of years, indicates an interspecies transmission of the virus between mice and humans coinciding with the development of agriculture. This transmission process may have resulted in the adaptation of MMTV to humans, ultimately evolving into HBRV. MMTV can infect human cells, as demonstrated in co-cultivation studies using 293 human kidney, and HeLa human cervical adenocarcinoma, and Hs578T breast epithelial cells.
HBRV transmission in humans
The route of HBRV transmission in humans remains unknown. However, some evidence suggests the possibility of microdroplet transmission, as viral sequences have been found in human saliva. It has been suggested that HBRV may be transmitted through saliva, as the virus can potentially reach the Waldeyer's ring structures in the throat. Similar to observations in mice, both betaretrovirus particles and nucleic acid have been documented in human breast milk. However, human milk has been shown to have a destructive effect on MMTV particles, and this route of transmission is not consistent with the epidemiological data concerning breast feeding.
Tropism
While contemporary understanding of tropism remains limited, recent studies have provided insights into HBRV's ability to infect biliary epithelial cells and replicate within lymphoid tissue.
Human betaretrovirus and linked diseases
Human betaretrovirus has been associated with various cancers and autoimmune conditions, such as primary biliary cholangitis. While HBRV may be a contributing factor, it is not the accepted cause at present, or the sole agent triggering these diseases. Other factors, such as genetic predisposition and other environmental exposures, are thought to play a contributary role in disease development. Nevertheless, several criteria used for linking environmental agents with disease have been firmly established for HBRV. The over-expression in human MCF7 cells of both WNT1 and FGF3 genes, main integration sites (INT) of MMTV in mouse, induces the synthesis of epithelial mesenchymal transition markers, mitochondrial proteins, glycolytic enzymes, and protein machinery synthesis. Many of these proteins are found transcriptionally overexpressed in human breast cancer cells in vivo.
Human betaretrovirus and cancer
The potential association between human mammary tumor virus (HBRV) and breast cancer has been a subject of interest for approximately 50 years since betaretrovirus particles resembling MMTV were observed in breast milk derived from close relatives of patients with breast cancer. Over the past three decades, numerous studies have provided substantial support to link a human mammary tumor virus with sporadic breast cancer and more recent research has identified viral sequences of HBRV in breast cancer samples from different regions, indicating the presence of the virus in breast cancer tissues.
Invasive sporadic carcinoma
More than 40 studies worldwide report evidence of HBRV infection in human sporadic breast cancer tissue ranging from ~30% to 40% of patients as compared to ~2% frequency in control samples.
Ductal carcinoma in situ
The rate of HBRV infection in DCIS has been found double than in invasive forms (80%). This finding indicates that HBRV plays a role in cancer initiation rather than in cancer progression, in line with what is known in the murine model.
Hereditary carcinoma
In contrast, hereditary breast carcinoma occurs as a result of etiopathogenetic factors unassociated with HBRV and this form of cancer has a very low frequency of HBRV ranging from 2-4%. The mounting evidence regarding the potential similarity in pathogenic mechanisms between HBRV and MMTV has further strengthened the hypothesis that the virus could be relevant in understanding sporadic breast cancer development and progression.
Human betaretrovirus and autoimmune diseases
Human betaretrovirus (HBRV) has been extensively studied in its connection to the autoimmune liver disease, primary biliary cholangitis (PBC). Various research approaches have been employed, including in vitro HBRV co-cultivation studies using biliary epithelium, the use of autoimmune biliary disease mouse models with MMTV infection and the study of patient samples. These studies have provided valuable insights into the link between HBRV and PBC. For example, HBRV infection leads to the expression of autoantigens linked with the development of the anti-mitochondrial antibodies used to diagnose PBC, and MMTV infection in mice is also linked with mitochondrial antigen expression and antimitochondrial antibody production.
Using PBC patient samples, researchers have isolated HBRV and identified up to 3000 viral integration sites within the human genome, providing strong evidence of a transmissible betaretrovirus infection in patients diagnosed with PBC. Furthermore, HBRV insertions and betaretrovirus RNA were commonly observed at the site of disease in the biliary epithelia of patients with PBC, and also in patients with autoimmune hepatitis.
Diagnosis of human betaretrovirus infection
The diagnosis of human betaretrovirus virus infection remains a challenging task due to the lack of widely available, sensitive, and reproducible diagnostic tests. One serological ELISA assay using the HBRV Env protein was positive in 10% of breast cancer and PBC patients as compared to ~2% of healthy subjects. Accordingly, this serological assay was less sensitive than the gold standard for demonstrating retroviral infection with proviral integrations. However, demonstration of genomic insertions is a research tool that is not readily adaptable for clinical use. HBRV is not readily detectable in blood by the polymerase chain reaction methodology and therefore a tissue diagnosis is required. However, this assay may be compromised by contamination. Further development of cellular immune assays using characterized HBRV Gag and Env peptides can be employed for diagnostic purposes by quantifying interferon-gamma production following stimulation of lymphocytes, providing a more sensitive assay than the ELISA.
Treatment of human betaretrovirus infection
Although there is currently no approved treatment specifically targeted for human betaretrovirus infection, some studies have demonstrated efficacy of repurposed HIV antiretroviral therapy. A randomized controlled trial using combination reverse transcriptase inhibitors, lamivudine and zidovudine, did not meet the study endpoints but showed a significant improvement in alkaline phosphatase, a biliary enzyme used to gauge disease activity in PBC patients. Another randomized controlled trial using the combination of tenofovir, emtricitabine, and lopinavir, was stopped early due to gastrointestinal side effects. However, patients able to tolerate long-term treatment demonstrated both biochemical and histological improvement.
The potential for immunotherapy of cancers exhibiting immunodominant betaretrovirus antigens has been studied in animal models. Using either a combination of monoclonal anti-MMTV p14 antibodies or adoptive T-cell transfer treatments, tumour growth was reduced in vivo. This may have translational relevance, as related p14 antigens can be detected in benign hyperplasia patient samples predating the development of breast cancer, and in a proportion of human breast cancer samples. Accordingly, the animal studies may provide a pathway for the future development of passive or active vaccination strategies to treat and possibly prevent human betaretrovirus-associated cancers.
References
Viruses
Betaretroviruses | Human betaretrovirus | [
"Biology"
] | 2,077 | [
"Viruses",
"Tree of life (biology)",
"Microorganisms"
] |
76,334,892 | https://en.wikipedia.org/wiki/Janus%20%28star%29 | Janus, also known by its name ZTF J203349.8+322901.1, is a transitioning white dwarf located more than away in the constellation Cygnus, discovered in 2019 by the Zwicky Transient Facility (ZTF), located at the Palomar Observatory, while looking for periodically variable white dwarfs. Subsequent observations using the Low-Resolution Imaging Spectrometer (LRIS) on the W. M. Keck Observatory discovered its two-faced nature, with one hemisphere dominated by hydrogen, and the other dominated by helium.
Properties
ZTF J203349.8+322901.1 is located more than away in the constellation Cygnus, with a mass between and (1.21 for an oxygen–neon core and 1.27 for a carbon–oxygen core), a radius of km and a surface temperature of approximately 35,000 Kelvin. It is rare in that it has two hemispheres of different gases, one dominated by hydrogen, and the other dominated by helium. Another star, GD 323, shares this feature, albeit much more subtle.
Janus' rotation period was observed by using CHIMERA, a high-speed imaging photometer, and HiPERCAM, a quintuple-beam imager (data collected on the nights of 6 and 9 September 2021 for a total of 2.1 hours), both located on the Gran Telescopio Canarias, which revealed a period of 14.97 minutes, which is much faster than what is usually observed in white dwarfs (hours to days). As it rotates, its spectrum transitions from only hydrogen lines to only helium lines at phases ≈ 0 and 0.5, respectively. There was no Zeeman splitting observed. The two hemispheres were measured to be at different temperatures, with the hydrogen side at K and the helium side at K.
Theories
There are some theories as to why ZTF J203349.8+322901.1's hemispheres are so starkly defined and of different compositions.
The first theory revolves around the belief that white dwarfs undergo an evolutionary phase, where helium sinks towards the bottom and hydrogen rises towards the top due to their masses. It is theorised that Janus was observed in an intermediate stage of this phase, and is exiting the DB gap on its way to becoming a DB white dwarf.
The second theory is based on asymmetric magnetic fields: If one hemisphere has a stronger magnetic field than the other, then the magnetic pressure at the pole will be higher, causing the hydrogen to diffuse towards the pole due to the ion pressure gradient, requiring a magnetic field of at least tens of kGs, and less than a few MG.
The third theory revolves around ZTF J203349.8+322901.1 being the result of a merger of two white dwarfs, due to its large mass and short rotation period.
References
White dwarfs
Cygnus (constellation) | Janus (star) | [
"Astronomy"
] | 606 | [
"Cygnus (constellation)",
"Constellations"
] |
76,335,740 | https://en.wikipedia.org/wiki/3%2C4-Toluenedithiol | 3,4-Toluenedithiol is an organosulfur compound with the formula . It is encountered as a colorless wax or oil. The compound is classified as an aromatic dithiol. It forms brightly colored derivatives with many metal ions. The compound is closely related to 1,2-benzenedithiol but is often more widely used because it is less expensive. 3,4-Toluenedithiol is prepared by reduction of the bis(sulfonyl chloride) with tin.
It has been investigated as a probe of thiol-disulfide reactions.
"Dithiol"
Under the name "dithiol", 3,4-toluenedithiol was popularized as a reagent in qualitative inorganic analysis. It was promoted as an alternative to hydrogen sulfide since it also forms colorful solid precipitates with a variety of metal ions.
References
Thiols | 3,4-Toluenedithiol | [
"Chemistry"
] | 190 | [
"Organic compounds",
"Thiols"
] |
76,337,114 | https://en.wikipedia.org/wiki/Marvin%20Marcus | Marvin David Marcus (July 31, 1927, Albuquerque, New Mexico – February 20, 2016, Santa Barbara, California) was an American mathematician, known as a leading expert on linear and multilinear algebra.
Education and career
From 1944 to 1946, Marvin Marcus served in the United States Navy. At the University of California, Berkeley, he graduated with a bachelor's degree in mathematics in 1950 and a Ph.D. in mathematics in 1953. His Ph.D. thesis The application of fixed-point theorems to the perturbation of ordinary differential equations was supervised by Stephen P. L. Diliberto.
At the University of British Columbia (UBC), Marcus was an instructor from 1954 to 1955, an assistant professor from 1955 to 1956, and an associate professor from 1957 to 1962. At UBC he became a friend of Henryk Minc and supervised the master's thesis of Robert Charles Thompson. For the academic year 1956–1957 Marcus was on sabbatical in Washington, D.C. at the National Bureau of Standards, where he worked with Morris Newman (1924–2007). At the University of California, Santa Barbara (UCSB), he was a full professor from 1962 to 1991, when he retired as professor emeritus. He chaired UCSB's mathematics department from 1963 and 1969 and created what gained an international reputation as the "Santa Barbara School of Linear Algebra". While chairing the department, he hired Henryk Minc, Robert Charles Thompson, and Ky Fan and brought many distinguished visiting mathematicians: Hans Heilbronn, Marshall Hall, Magnus Hestenes, Alan J. Hoffman, H. J. Ryser, Hans Schneider, Olga Taussky-Todd, John "Jack" Todd, and Hans Zassenhaus, as well as the then unknown Richard A. Brualdi. At UCSB, Marcus held an appointment in the mathematics department from 1962 to 1983, joint appointments in both the mathematics and computer science departments from 1983 to 1987, and an appointment solely in the computer science department from 1987 to 1991. He founded UCSB's Microcomputer Laboratory in 1979.
During the years 1963 to 1969, UCSB mathematicians did significant research on such topics as monotone matrix functions in the sense of Charles Loewner, linear operators on symmetry classes of tensors, and immanants and other generalized matrix functions. At UCSB Marcus established the semiautonomous Institute for Interdisciplinary Applications of Algebra and Combinatorics, which he directed from 1973 to 1979. Marcus was one of the founding editors of the journal Linear Algebra and Its Applications. With Robert Charles Thompson, he was the co-founder of the journal Linear and Multilinear Algebra, whose first issue was published in 1973. He was the section editor for linear algebra in Addison-Wesley's series Encyclopedia of mathematics and its applications.
According to Marcus's former doctoral student Robert Grone, Marcus did pioneering, fundamental research in "numerical ranges, matrix inequalities, linear preservers and multilinear algebra". Marcus was the author or co-author of more than 200 articles and problem solutions and more than 20 books. His three most important books might be Finite Dimensional Multilinear Algebra, Part I (1973, Marcel Dekker), Finite Dimensional Multilinear Algebra, Part II (1975, Marcel Dekker), and A Survey of Matrix Theory and Matrix Inequalities (1st edition 1964; reprint 1969; Dover reprint 1992).
In 1966, Marcus and Minc received the Mathematical Association of America's Lester R. Ford Award for their 1965 article Permanents.
Personal life
In 1951 in California, Marvin Marcus married Arlen Ingrid Sahlman (1923–2005). They became the parents of a son and a daughter, but later divorced. Marvin Marcus was predeceased by his second wife — there were no children from his second marriage. He enjoyed playing tennis and reading about science and narratives written by travelers.
Selected publications
Articles
Books
References
1927 births
2016 deaths
20th-century American mathematicians
21st-century American mathematicians
Combinatorialists
Linear algebraists
University of California, Berkeley alumni
University of California, Santa Barbara faculty
People from Albuquerque, New Mexico | Marvin Marcus | [
"Mathematics"
] | 853 | [
"Combinatorialists",
"Combinatorics"
] |
76,337,686 | https://en.wikipedia.org/wiki/Social%20media%27s%20influence%20on%20consumerism | Between 2020 and 2024 social media use has increased, with user engagement becoming normal for a variety of social media users. Platforms such as TikTok, YouTube, and Instagram are well-known forms of social media that provide platforms for users, and allow them to gain followers. Through this flow of followers, "influencers" are then able to promote products and services to their audiences. For general background, influencers make a name for themselves on social media through the content that they create and put out there. From their content, they begin to gather a following from social media users who tend to feel more connected to them through their mutual interests.
Defining social media
Social media is a social medium, in the form of technology, that moderates, initiates, or influences communicative processes. It not only allows users to build a page or platform on each specific website, but also encourages content creation of their choosing. Not only that, but social media is another relatively "new" wave of communication. Social media creates a sense of people coming together virtually and a way of communicating. Some popular social media applications consist of TikTok, YouTube, Instagram, and Facebook. However, there are also many others that are becoming more popular. When these social media sites were created, they were mainly used as a way to share information about one's life to friends, family, and other followers of the creator. The sites themselves were also competing with each other early on in their development, but have recently shifted their efforts toward capturing audiences' time and attention. With this push to engage their audiences, social media platforms have now started to pay those who have a large influence (follower count) on their platform, or those who promote sponsored products to viewers.
Influence of public figures
Those who have the ability to persuade potential buyers of a product by promoting these items on social media are known as influencers. These individuals often become popular due to their impacts on beauty standards or lifestyle content, as well as how these habits can apply to the general public. Additionally, their prevalence on mainstream media makes their faces more recognizable, and more likely to obtain a larger platform following. According to research on 2023 social media influencers, Cristiano Ronaldo, Charli D'amelio, and Kylie Jenner are among the top ten, seen promoting various products through their platforms. These content creators, on average, have over ten million active followers. They are also exposed to each of their paid promotions. Because of this exposure, over 54% of social media users utilize these platforms to research and validate online purchases, with 71% of these individuals being more likely to purchase a given product. Moreover, the exposure that influencers have on people all comes back to the sense of trust that has been built between the consumer and the influencer. In simpler terms, the more trust the consumer has in the influencer, the more of a role the influencer plays in consumerism. With that being said, there is a down side to all of this. Influencers may think that they are satisfying the brands needs for their influencer role, but they might not even realize that this may be the case. Things like humblebragging for example, may actually make the consumer think more negatively about the liking of a product. In simpler terms, the way an influencer goes about their business definitely has an effect on the consumer's point of view.
Trends and fads
Social media is known for having short-lived trends relating to topics such as beauty, lifestyle, physical fitness, fashion, and many more. Furthermore, many of these fads encourage consumptive behavior, which promotes various material items and making name-brand products desirable to the public. Some of the more recent trends in 2023 consist of hygiene and wellness products such as snail mucin, sea moss, stylish tote bags, insulated water bottles, as well as a myriad of eco-friendly products for those what are trying to take a more sustainable route to consumption. Because these trends don't last too long, they are often replaced by a newer trend, and often forgotten about within a short period of time.
Data behind the spending
In general, positive correlations have been found between materialism, consumption, and social media engagement. One of the main reasons for this is due to the fact that the process of shopping, from the introduction of a product to the point of purchase, happens in minutes. Social media has made it very easy for users to find new products on the market, and provide them with online options of payment and delivery. Additionally, because social media users usually follow the content of those who are similar to them, their opinions carry more weight for consumers, and make products more desirable. With the introduction of more influencers, comes more possible products to sell, reaching a larger audience and motivating viewers to purchase. Therefore, this whole process and way of using social media is just getting started.
Expert critiques on observed relationship
There has been found to be a generally negative relationship, which is shared between high levels of materialism and overall life satisfaction. Since high levels of consumptive behavior also have to do with social media use, this suggests that social media platforms and the influencers who use them, likely contribute to the rise in consumerist lifestyles. One critique of this observed relationship is that influencers should recognize the impact they have, and consider the ethical authenticity of the products they're promoting. If the content they are putting out is untrue to their brand and untrue to their audience, it may be morally and ethically wrong to engage in these paid promotions. If influencers recognize this conflict of interest, and only endorse those that are true to their values, social media users may think about their purchase intentions more, resulting in less compulsive purchases. Another critique made by experts in the field has to do with the idea of verification, which is essentially a social media term that refers to a person's account being certified or authentic by the platform itself. This verification often carries another meaning of high status when obtained, and is sought after by many influencers who are trying to gain a larger following. Critics argue that because verified users are viewed as more original, those who follow them are much more likely to purchase any products they promote through their page.
References
Consumer behaviour
Consumerism | Social media's influence on consumerism | [
"Biology"
] | 1,294 | [
"Behavior",
"Consumer behaviour",
"Human behavior"
] |
76,337,691 | https://en.wikipedia.org/wiki/Technoprobe | Technoprobe is a designer and manufacturer of probe cards and measurement technologies for integrated circuits headquartered in Italy.
History
Technoprobe was founded in Merate near Milan in 1996 by Giuseppe Crippa, who had developed a new and more rapid method to manufacture probe cards.
In 2007, Technoprobe marketed the first probe card with vertical MEMS.
By 2017, it was the world's third largest manufacturer of probe cards, and by 2020, it was second largest.
It became a public company in 2022, with shares available for trading at Milan's stock exchange.
In 2023, Technoprobe acquired Harbor Electronics, a company based in Santa Clara, California. Teradyne acquired a 10% equity stake and sold its device interface solutions division to Technoprobe
References
External links
Equipment semiconductor companies
Electronic test equipment manufacturers
2022 initial public offerings
Computer hardware companies
Italian companies established in 1996
Multinational companies headquartered in Italy | Technoprobe | [
"Technology",
"Engineering"
] | 186 | [
"Equipment semiconductor companies",
"Computer hardware companies",
"Semiconductor fabrication equipment",
"Computers"
] |
76,338,017 | https://en.wikipedia.org/wiki/25%20Sextantis | 25 Sextantis (HD 90044; HR 4082; 43 G. Sextantis), or simply 25 Sex, is a star located in the equatorial constellation Sextans; it also bears the variable star designation SS Sextantis (SS Sex). With an average apparent magnitude of 5.97, 25 Sex is barely visible to the naked eye, even under ideal conditions. Gaia DR3 parallax measurements imply a distance of 345 light-years, and it is currently drifting away with a heliocentric radial velocity of approximately . At its current distance, 25 Sex's average brightness is diminished by an interstellar extinction of 0.17 magnitudes and it has an absolute magnitude of +0.86.
The star was first discovered to be variable in 1980 by French astronomers P. Renson & J. Manfroid. They observed a 4.37 day period for 25 Sex and a flucation of 0.03 magnitudes in optical light. The next year, it was confirmed to be variable and it was given the variable star designation SS Sextantis. J. Manfroid and G. Mathys refined the period of 25 Sextantis to be slightly longer than previously measured; the period of SS Sextantis was measured at 4.39 days but with a larger uncertainty. In 1993, D. A. Bohlender and colleagues measured the magnetic field of the star and found that it varied between 650 and 1,200 gauss, although with some uncertainty about the variation. Subsequent observations provide a much wider range between 1 and -1,000 gauss.
25 Sex has a stellar classification of B9pSi(CrSr), indicating that it is a Bp star with abundance of silicon, chromium, and strontium in its spectrum. It has 2.48 times the mass of the Sun and 2.22 times the radius of the Sun. It radiates 45.7 times the luminosity of the Sun from its photosphere at an effective temperature of roughly , giving it a bluish-white hue when viewed in the night sky. 25 Sex is metal deficient with an iron abundance 64.6% of the Sun's and it is estimated to be 309 million years old. At that age, it has completed 56% of its main sequence lifetime. Like many chemically peculiar stars it spins modestly—having a projected rotational velocity of .
References
Alpha2 Canum Venaticorum variables
B-type main-sequence stars
Sextans
Sextantis, SS
Sextantis, 25
Sextantis, 43
BD-03 02911
090044
050885
4082
00001712781
Astronomical objects discovered in 1980 | 25 Sextantis | [
"Astronomy"
] | 558 | [
"Sextans",
"Constellations"
] |
73,382,085 | https://en.wikipedia.org/wiki/Glossary%20of%20developmental%20biology | This glossary of developmental biology is a list of definitions of terms and concepts commonly used in the study of developmental biology and related disciplines in biology, including embryology and reproductive biology, primarily as they pertain to vertebrate animals and particularly to humans and other mammals. The developmental biology of invertebrates, plants, fungi, and other organisms is treated in other articles; e.g terms relating to the reproduction and development of insects are listed in Glossary of entomology, and those relating to plants are listed in Glossary of botany.
This glossary is intended as introductory material for novices; for more specific and technical detail, see the article corresponding to each term. Additional terms relevant to vertebrate reproduction and development may also be found in Glossary of biology, Glossary of cell biology, Glossary of genetics, and Glossary of evolutionary biology.
A
B
C
D
E
F
G
H
I
J
K
L
M
N
O
P
Q
R
S
T
U
V
W
X
Y
Z
See also
Introduction to developmental biology
Outline of developmental biology
Outline of cell biology
Glossary of biology
Glossary of cell biology
Glossary of genetics
Glossary of evolutionary biology
References
External links
Developmental biology
Glossaries of biology
Wikipedia glossaries using description lists | Glossary of developmental biology | [
"Biology"
] | 248 | [
"Glossaries of biology",
"Behavior",
"Developmental biology",
"Reproduction"
] |
73,382,341 | https://en.wikipedia.org/wiki/Caliciopsis%20pinea | Caliciopsis pinea, or Caliciopsis pine canker, is a species of fungus in the family Coryneliaceae.
It is most often found on Pinus strobus in New England, New York, Virginia, West Virginia, Quebec and Ontario. It has also been found on Pinus rigida, Pinus pungens, Pinus echinata, Pinus resinosus, and Pinus virginiana in North America. It has also been reported in Europe on Pinus pinaster, Pinus radiata, Pinus pumilo, and Abies species.
The fungus forms an insect/disease complex with white pine bast scale (Matsucoccus macrocicatrices), which causes branch and sapling mortality in Pinus strobus.
References
Eurotiomycetes
Taxa named by Charles Horton Peck
Fungi described in 1883
Fungi of Europe
Fungi of North America
Fungus species | Caliciopsis pinea | [
"Biology"
] | 187 | [
"Fungi",
"Fungus species"
] |
73,384,479 | https://en.wikipedia.org/wiki/Common%20envelope%20jets%20supernova | Common envelope jets supernova (CEJSN) is a type of supernova, where the explosion is caused by the merger of a giant or supergiant star with a compact star such as a neutron star or a black hole. As the compact star plunges into the envelope of the giant/supergiant, it begins to accrete matter from the envelope and launches jets that can disrupt the envelope. Often, the compact star eventually merges with the core of the giant/supergiant; other times the infall stops before core merger.
This kind of supernova has been invoked to explain certain kinds of supernova-like phenomena, including iPTF14hls.
History and process
In order to explain the unusual supernova iPTF14hls, Soker and Gilkis 2018 proposed a model where astrophysical jets eject the common envelope of a merging star. They may constitute 10^-6 to 2*10^-5 of all core collapse supernovae.
In their model, iPTF14hls was a binary star consisting of a giant star and a neutron star. The latter plunged into the envelope of the former and began to accrete material, emitting neutrinos as it did so but without substantially deforming the giant. Eventually, it would have reached the core of the giant and accreted mass at a sufficient rate to produce jets. These jets emanate from the polar areas of the neutron star and can effectively eject matter in these directions, but do not effectively act on material accreting along the neutron star's equatorial plane, which thus continues to reach the neutron star. The jets impact the envelope, inflating it in the form of large bubbles ("cocoons") that remove material from the envelope at speeds approaching a tenth of the speed of light. This causes the envelope of the giant star to be ejected over a timespan of a few hundred days, before the core itself is consumed in about a day, producing gravitational waves. The exiting jets can interact with pre-existent gas clouds around the giant, which creates the luminosity of the supernova and which can last for timespans reaching years.
Depending on the original architecture of the stellar system, many variations on this general process are possible, such as when the incoming star is itself a binary such as a neutron star-neutron star binary or other combinations of a neutron star with a companion. In these cases, the binary may break up during the merger, with one of the binary objects ejected. The original core of the star may be tidally disrupted, forming an accretion disk around the neutron star. The incoming neutron star may instead be a black hole; these may be the source of cosmic ultra-high-energy neutrinos.
There are several processes that can cause the neutron star to penetrate the giant. Giant stars grow in size just at the end of their evolution, and can envelop a companion star in the process. When a star goes supernova and produces a neutron star, the neutron star receives a "kick" that causes it to penetrate the other star. Finally, interactions between the neutron star-giant binary with a third star, typically the third member star of the group, can cause the neutron star orbit to contract until it interacts with the envelope of the giant.
Concomitant processes
Already before the actual penetration, tidal acceleration of the giant's envelope by the neutron star causes it to expand, possibly clearing the polar regions of the giant of matter before the merger begins. This lets the jets exit the star from the poles before the neutron star merges with the core; otherwise they are only visible at the beginning of the envelope interaction or when the actual core interacts with the neutron star. The energy that the jets inject into the envelope can cause it to expand so that even when the orbit takes the neutron star out of the envelope, accretion and jet launching continue. These jets are weaker than the ones launched inside the original envelope, but are more efficient at creating radiation as they interact with already-emplaced gas.
A key requirement for the occurrence of a common envelope jets supernova is that the neutron star can form an accretion disk as it begins to absorb the material of the companion. Hydrodynamic simulations have offered contrasting results on whether this is possible and on the accretion rate resulting from the interaction, although there is empirical evidence that at least white dwarfs can generate such disks and jets; white dwarf properties resemble these of neutron stars. The process requires high accretion rates, which in turn require that large amounts of material and energy be removed from the proximity of the neutron star; this is accomplished through the emission of neutrinos, which carry energy away.
The conditions during a CEJSN may allow the r-process of nucleosynthesis to take place in the jets, in particular when a binary neutron star is involved, since unlike the core of a conventional supernova the CEJSN is not an effective neutrino source. Unlike regular neutron star mergers, the CEJSN is not delayed by the time it takes for the neutron star binary to shrink from gravitational wave emission and thus CEJSN can contribute r-process elements early in the history of the universe. The r-process element enrichment of the galaxy Reticulum II may be explained through a CEJSN, which efficiently distributed r-process elements across the galaxy.
Examples
Apart from iPTF14hls, other events such as the supernovae SN1979c, SN1998e, SN2019zrk, SN 2020faa and the radio transient VT J121001+495647 have been proposed to be CEJSNs. The gamma-ray burst GRB 101225A could have formed through a common envelope jets supernova-like interaction with a helium star. A CEJSN where the core of the companion star was disrupted may have given rise to the enigmatic supernova remnant W49B. Fast blue optical transients might constitute CEJSNs as well.
Impostors
This process does not always result in the immediate destruction of the giant; if the giant star survives, a supernova impostor can occur instead, possible examples are the supernova SN 2009ip and the transient AT2018cow. The mass loss the giant suffers during the interaction can cause the orbit of the neutron star to expand and thus to exit the giant's envelope again; that way repeating explosions can occur since the core isn't destroyed by the merger. Eventually, a stripped core can be left that itself will go supernova and form another neutron star; this may be a major source of binary neutron stars.
References
Sources
Supernovae
Stellar evolution
Binary stars | Common envelope jets supernova | [
"Physics",
"Chemistry",
"Astronomy"
] | 1,383 | [
"Supernovae",
"Astronomical events",
"Astrophysics",
"Stellar evolution",
"Explosions"
] |
73,384,654 | https://en.wikipedia.org/wiki/Chessboard%20complex | A chessboard complex is a particular kind of abstract simplicial complex, which has various applications in topological graph theory and algebraic topology. Informally, the (m, n)-chessboard complex contains all sets of positions on an m-by-n chessboard, where rooks can be placed without attacking each other. Equivalently, it is the matching complex of the (m, n)-complete bipartite graph, or the independence complex of the m-by-n rook's graph.
Definitions
For any two positive integers m and n, the (m, n)-chessboard complex is the abstract simplicial complex with vertex set that contains all subsets S such that, if and are two distinct elements of S, then both and . The vertex set can be viewed as a two-dimensional grid (a "chessboard"), and the complex contains all subsets S that do not contain two cells in the same row or in the same column. In other words, all subset S such that rooks can be placed on them without taking each other.
The chessboard complex can also be defined succinctly using deleted join. Let Dm be a set of m discrete points. Then the chessboard complex is the n-fold 2-wise deleted join of Dm, denoted by .
Another definition is the set of all matchings in the complete bipartite graph .
Examples
In any (m,n)-chessboard complex, the neighborhood of each vertex has the structure of a (m − 1,n − 1)-chessboard complex. In terms of chess rooks, placing one rook on the board eliminates the remaining squares in the same row and column, leaving a smaller set of rows and columns where additional rooks can be placed. This allows the topological structure of a chessboard to be studied hierarchically, based on its lower-dimensional structures. An example of this occurs with the (4,5)-chessboard complex, and the (3,4)- and (2,3)-chessboard complexes within it:
The (2,3)-chessboard complex is a hexagon, consisting of six vertices (the six squares of the chessboard) connected by six edges (pairs of non-attacking squares).
The (3,4)-chessboard complex is a triangulation of a torus, with 24 triangles (triples of non-attacking squares), 36 edges, and 12 vertices. Six triangles meet at each vertex, in the same hexagonal pattern as the (2,3)-chessboard complex.
The (4,5)-chessboard complex forms a three-dimensional pseudomanifold: in the neighborhood of each vertex, 24 tetrahedra meet, in the pattern of a torus, instead of the spherical pattern that would be required of a manifold. If the vertices are removed from this space, the result can be given a geometric structure as a cusped hyperbolic 3-manifold, topologically equivalent to the link complement of a 20-component link.
Properties
Every facet of contains elements. Therefore, the dimension of is .
The homotopical connectivity of the chessboard complex is at least (so ).
The Betti numbers of chessboard complexes are zero if and only if . The eigenvalues of the combinatorial Laplacians of the chessboard complex are integers.
The chessboard complex is -connected, where . The homology group is a 3-group of exponent at most 9, and is known to be exactly the cyclic group on 3 elements when .
The -skeleton of chessboard complex is vertex decomposable in the sense of Provan and Billera (and thus shellable), and the entire complex is vertex decomposable if . As a corollary, any position of k rooks on a m-by-n chessboard, where , can be transformed into any other position using at most single-rook moves (where each intermediate position is also not rook-taking).
Generalizations
The complex is a "chessboard complex" defined for a k-dimensional chessboard. Equivalently, it is the set of matchings in a complete k-partite hypergraph. This complex is at least -connected, for
References
Topological graph theory | Chessboard complex | [
"Mathematics"
] | 887 | [
"Topology",
"Mathematical relations",
"Topological graph theory",
"Graph theory"
] |
73,385,265 | https://en.wikipedia.org/wiki/CR%20Bo%C3%B6tis | CR Boötis is an interacting binary system in the northern constellation of Boötes, abbreviated CR Boo. It is one of the best-known AM Canum Venaticorum stars. The system varies widely in brightness, ranging in apparent visual magnitude from 13.6 down to 17.5. The distance to this system is approximately 1,150 light years from the Sun, based on parallax measurements.
The variable luminosity of this object was discovered in 1983 by M. A. Wood and associates, with a light curve that is very similar to that of AM Canum Venaticorum. It was found to have an ultraviolet excess by the Palomar-Green survey and assigned the identifier PG 1346+082 in 1986. The system varies in both its photometric and spectroscopic properties, with a photometric quasi-period of 4–5 days. The optical spectrum displays only lines of helium. It was given its variable star designation, CR Boötis, in 1987, in literature up until that time it was called PG 1346+082.
Rapid flickering suggests this is a close binary system undergoing mass transfer, while emission by neutral helium indicates there is a thick accretion disk orbiting a compact object. The lack of X-ray emission means this accreting object is a white dwarf, rather than something more massive. The lack of hydrogen in the spectrum demonstrates that the donor star is a helium white dwarf with a lower mass than the primary. The pair have a brief orbital period of with a mass ratio of 0.101. The orbital plane is inclined at an angle of about 30° to the line of sight from the Earth.
This system displays two different states. The first is a lower state of quiescence that displays regular superoutbursts similar to ER Ursae Majoris on a roughly 46 day cycle. The second state is brighter with frequent outbursts. The system becomes bluer during superoutbursts, with a higher temperature.
References
Further reading
AM CVn stars
White dwarfs
Binary stars
Boötes
Boötis, CR | CR Boötis | [
"Astronomy"
] | 423 | [
"Boötes",
"Constellations"
] |
73,385,311 | https://en.wikipedia.org/wiki/Barnard%201 | Barnard 1 (B1) is a dark nebula in the constellation of Perseus. It belongs to the Perseus molecular cloud complex and is located at a distance of 800 light-years from the Sun. The Perseus molecular cloud has several regions in the neighborhood of the Sun that are actively forming low- and intermediate-mass stars. The Barnard 1 or Perseus molecular cloud complex is at right ascension and declination .
Reflection Nebula Regions
Barnard 1 contains two reflection nebula regions: NGC 1333 and IC 348 are embedded in the Perseus molecular cloud complex.
References
Dark nebulae
Perseus (constellation)
Barnard objects | Barnard 1 | [
"Astronomy"
] | 131 | [
"Perseus (constellation)",
"Nebula stubs",
"Astronomy stubs",
"Constellations"
] |
73,386,024 | https://en.wikipedia.org/wiki/Barium%20chloride%20fluoride | Barium chloride fluoride is an inorganic chemical compound of barium, chlorine, and fluorine. Its chemical formula is . The compound naturally occurs as zhangpeishanite mineral of the matlockite group. One of the deposits where the mineral is mined is Bayan Obo in China.
Synthesis
Barium fluoride can be prepared by precipitating barium chloride and ammonium fluoride in a solution.
Physical properties
Barium chloride fluoride forms white crystals. The crystal structure of BaClF is a tetragonal distortion of that of fluoride type .
The compound is poorly soluble in water.
References
Barium compounds
Chlorine compounds
Fluorine compounds
Mixed anion compounds | Barium chloride fluoride | [
"Physics",
"Chemistry"
] | 150 | [
"Matter",
"Inorganic compounds",
"Mixed anion compounds",
"Inorganic compound stubs",
"Ions"
] |
73,387,060 | https://en.wikipedia.org/wiki/Lentinula%20ixodes | Lentinula ixodes is a species of edible agaric fungus in the family Marasmiaceae that is found in Amazon rainforest. Originally described as Agaricus ixodes from Guyana by Camille Montagne in 1854, it was then considered a synonym of Lentinula boryana and reestablished as an independent species by J.S. Oliveira, Tiara S. Cabral, Ruby Vargas-Isla & Noemia K. Ishikawa in 2022. It grows on wood such as Bertholletia excelsa. Phylogenetic research shows it is closely related (but still intersterile) to another Amazon species, Lentinula raphanica, but it can be visually distinguished by the deep orange-brown pileus eventually having fine scales and general similarity to L. boryana complex.
References
External links
Fungi described in 2022
Edible fungi
Marasmiaceae
Fungus species | Lentinula ixodes | [
"Biology"
] | 179 | [
"Fungi",
"Fungus species"
] |
73,387,374 | https://en.wikipedia.org/wiki/Lentinula%20madagasikarensis | Lentinula madagasikarensis is a species of edible agaric fungus in the family Marasmiaceae that is found in Madagascar. It was described by Buyck, Randrianjohany & Looney in 2021. It is "strikingly" similar to the shiitake mushroom in appearance, but phylogenetic research shows its closest relative is Costa Rican Lentinula aciculospora. It grows on various dead wood in forests dominated by Uapaca densifolia, Sarcolaenaceae and Eucalyptus robusta. Its description expands the known range of Lentinula genus transoceanically and by over 4000 miles (from the Asian locations of shiitake)
References
External links
Fungi described in 2021
Edible fungi
Marasmiaceae
Fungus species | Lentinula madagasikarensis | [
"Biology"
] | 154 | [
"Fungi",
"Fungus species"
] |
73,388,311 | https://en.wikipedia.org/wiki/Non%20B-DNA | Non-B DNA refers to DNA conformations that differ from the canonical B-DNA conformation, the most common form of DNA found in nature at neutral pH and physiological salt concentrations. Non-B DNA structures can arise due to various factors, including DNA sequence, length, supercoiling, and environmental conditions. Non-B DNA structures can have important biological roles, but they can also cause problems, such as genomic instability and disease.
Types of Non-B DNA
Non-B DNA can be classified into several types, including A-DNA, Z-DNA, H-DNA, G-quadruplexes, and Triplexes (Triple-stranded DNA).
A-DNA is a right-handed double helix structure for RNA-DNA duplexes and RNA-RNA duplexes that is less common than the more well-known B-DNA structure. A-DNA is a form of DNA that occurs when the DNA is in a dehydrated state or is bound to certain proteins, and it has a shorter and wider helix than B-DNA. The helix of A-DNA is also tilted and compressed compared to B-DNA. A-DNA is believed to play a role in certain biological processes, such as DNA replication and gene expression.
Z-DNA is a left-handed helix with a zigzag backbone, in contrast to the right-handed B-DNA helix. It is stabilized by the alternating purine-pyrimidine sequence and can form in regions of DNA with high GC-content, supercoiling, or negative superhelicity. Z-DNA has been implicated in gene regulation and immunity, but it can also induce DNA damage and inflammation.
H-DNA is a triple-stranded DNA structure that forms when two homologous DNA strands come together and one strand displaces the other. H-DNA is stabilized by Hoogsteen base pairing and can cause mutations, rearrangements, and genome instability. H-DNA is thought to be involved in DNA replication, recombination, and repair, but its precise biological functions remain unclear.
G-quadruplexes are four-stranded DNA structures formed by guanine-rich sequences. G-quadruplexes can form in telomeres, oncogene promoters, and other genomic regions and can affect gene expression, DNA replication, and telomere maintenance. G-quadruplexes are also potential targets for cancer therapy.
Triplexes are three-stranded DNA structures formed by the binding of a third strand to a DNA duplex. Triplexes can be formed by pyrimidine-rich or purine-rich third strands, and they can occur in genomic regions with inverted repeats, mirror repeats, or other special sequences. Triplexes can affect DNA replication, transcription, and recombination, but they can also cause DNA damage and mutagenesis.
Implications of Non-B DNA
Non-B DNA can have significant implications for DNA biology and human health. For example, Z-DNA has been implicated in immunity and autoimmune diseases, such as lupus and arthritis. H-DNA has been implicated in genomic instability and cancer, and G-quadruplexes have been linked to telomere maintenance, oncogene activation, and cancer. Triplexes have been associated with genetic diseases, such as fragile X syndrome and Huntington's disease.
References
DNA
Biochemistry terminology | Non B-DNA | [
"Chemistry",
"Biology"
] | 705 | [
"Biochemistry",
"Biochemistry terminology"
] |
73,389,069 | https://en.wikipedia.org/wiki/%C5%A0ilal%C4%97%20Event | The Šilalė Event was an extinction event affecting conodonts during the Přídolí, the final stage of the Silurian period.
Timing
The Šilalė Event, first identified in the Milaičiai-103 core in southwestern Lithuania, is marked by a negative carbon isotope excursion in carbonate rocks known as the Šilalė Negative Carbon Isotope Event. This isotopic excursion is also known from the Jočionys-299 borehole in eastern Lithuania, as well as in coeval deposits in the Appalachian Basin of North America and has also been termed the Šilalė Low. The amplitudes of the ~405 Ka long eccentricity cycle were at their lowest point of the entire Přídolí during the Šilalė Event. The end of the Šilalė Event corresponds to the beginning of the Delotaxis detorta conodont biozone, a conodont biozone once erroneously thought to have corresponded to the latest Přídolí.
Effects
The Šilalė Event resulted in a decline in conodont diversity and a corresponding increase not just in the diversity of brachiopods but in their absolute abundance as well. After the event, conodont abundance surged during the interval of biotic recovery from the Šilalė mass rarity.
See also
Ireviken Event
Lundgreni Event
Mulde Event
Lau Event
Kellwasser Event
Dasberg Event
Hangenberg Event
References
Extinction events
Silurian events | Šilalė Event | [
"Biology"
] | 292 | [
"Evolution of the biosphere",
"Extinction events"
] |
73,390,595 | https://en.wikipedia.org/wiki/Subdivision%20bifiltration | In topological data analysis, a subdivision bifiltration is a collection of filtered simplicial complexes, typically built upon a set of data points in a metric space, that captures shape and density information about the underlying data set. The subdivision bifiltration relies on a natural filtration of the barycentric subdivision of a simplicial complex by flags of minimum dimension, which encodes density information about the metric space upon which the complex is built. The subdivision bifiltration was first introduced by Donald Sheehy in 2011 as part of his doctoral thesis (later subsumed by a conference paper in 2012) as a discrete model of the multicover bifiltration, a continuous construction whose underlying framework dates back to the 1970s. In particular, Sheehy applied the construction to both the Vietoris-Rips and Čech filtrations, two common objects in the field of topological data analysis. Whereas single parameter filtrations are not robust with respect to outliers in the data, the subdivision-Rips and -Cech bifiltrations satisfy several desirable stability properties.
Definition
Let be a simplicial complex. Then a nested sequence of simplices of is called a flag or chain of . The set of all flags of comprises an abstract simplicial complex, known as the barycentric subdivision of , denoted by . The barycentric subdivision is naturally identified with a geometric subdivision of , created by starring the geometric realization of at the barycenter of each simplex.
There is a natural filtration on by considering for each natural number the maximal subcomplex of spanned by vertices of corresponding to simplices of of dimension at least , which is denoted . In particular, by this convention, then . Considering the sequence of nested subcomplexes given by varying the parameter , we obtain a filtration on known as the subdivision filtration. Since the complexes in the subdivision filtration shrink as increases, we can regard it as a functor from the opposite posetal category to the category of simplicial complexes and simplicial maps.
Let be a partially ordered set. Given a simplicial filtration , regarded as a functor from the posetal category of to the category , by applying the subdivision filtration object-wise on , we obtain a two-parameter filtration , called the subdivision bifiltration.
In particular, when we take to be the Rips or Čech filtration, we obtain bifiltrations and , respectively.
Properties
The subdivision-Čech bifiltration is weakly equivalent to the multicover bifiltration, implying that they have isomorphic persistent homology. A combinatorial proof of this statement was given in Sheehy's original conference paper, but a more algebraic version was presented in 2017 by Cavanna et al. The ideas from Cavanna's proof were later generalized by Blumberg and Lesnick in a 2022 paper on 2-parameter persistent homology.
By the size of a bifiltration, we mean the number of simplices in the largest complex. The subdivision-Čech bifiltration has exponential size as a function of the number of vertices. This implies that its homology cannot be directly computed in polynomial time. However, for points in Euclidean space, the homology of subdivision-Čech can be computed in polynomial time, up to weak equivalence, via a construction known as the rhomboid bifiltration. As a precursor to the rhomboid bifiltration, Edelsbrunner and Osang presented in 2021 a polyhedral cell complex called the rhomboid tiling, which they used to compute horizontal or vertices slices of the multicover bifiltration up to weak equivalence. This was extended a year later by Corbet et al. to the rhomboid bifiltration, which is weakly equivalent to the multicover bifiltration, but has polynomial size.
References
Applied mathematics
Computational topology
Data analysis | Subdivision bifiltration | [
"Mathematics"
] | 815 | [
"Topology",
"Applied mathematics",
"Computational topology",
"Computational mathematics"
] |
73,391,672 | https://en.wikipedia.org/wiki/K2-18b | K2-18b, also known as EPIC 201912552 b, is an exoplanet orbiting the red dwarf K2-18, located away from Earth. The planet is a sub-Neptune about 2.6 times the radius of Earth, with a 33-day orbit within the star's habitable zone. This means it receives about a similar amount of starlight as the Earth receives from the Sun. Initially discovered with the Kepler space telescope, it was later observed by the James Webb Space Telescope (JWST) in order to study the planet's atmosphere.
In 2019 the presence of water vapour in K2-18b's atmosphere was reported, drawing attention to this system. In 2023, the JWST detected carbon dioxide and methane in the atmosphere of K2-18b. JWST’s data has been variously interpreted as indicating a water ocean planet with a hydrogen-rich atmosphere, and a gas-rich mini-Neptune. K2-18b has been studied as a potential habitable world that, temperature aside, more closely resembles a gas planet like Uranus or Neptune than Earth.
Host star
K2-18 is an M dwarf of the spectral class M3V in the constellation Leo, away from the Sun. The star is colder and smaller than the Sun, having a temperature of and a radius 45% of the Sun's, and is not visible to the naked eye. The star is 2.4 ± 0.6 billion years old and displays moderate stellar activity, but whether it has star spots, which would tend to create false signals when a planet crosses them, is unclear. K2-18 has an additional planet inside of K2-18b's orbit, K2-18c, which may interact with K2-18b through tides.
It is estimated that up to 80% of all M dwarf stars have planets in their habitable zones, including the stars LHS 1140, Proxima Centauri and TRAPPIST-1. The small mass, size and low temperatures of these stars and frequent orbits of the planets make it easier to characterize the planets. On the other hand, the low luminosity of the stars can make spectroscopic analysis of planets difficult, and the stars are frequently active with flares and inhomogeneous stellar surfaces (faculae and starspots), which can produce erroneous spectral signals when investigating a planet.
Physical properties
K2-18b has a radius of , a mass of , and orbits its star in 33 days. From Earth, it can be seen passing in front of the star. The planet is most likely tidally locked to the star, although considering its orbital eccentricity, a spin-orbit resonance like Mercury is also possible.
The density of K2-18b is about intermediate between Earth and Neptune implying that the planet has a hydrogen-rich envelope. The planet may either be rocky with a thick envelope or have a Neptune-like composition. A pure water planet with a thin atmosphere is less likely. Planets with radii of about are unexpectedly rare relative to their expected occurrence rate, a phenomenon known as the radius valley. Presumably, planets with intermediary radii cannot hold their atmospheres against the tendency of their own energy output and the stellar radiation to drive atmospheric escape. Planets with even smaller radii are known as Super-Earths and those with larger radii as Sub-Neptunes.
The planet may have taken a few million years to form. Tidal heating is unlikely. Internal heating may increase temperatures at large depths, but is unlikely to significantly affect the surface temperature. If an ocean exists, it is probably underlaid by a high-pressure ice layer on top of a rocky core, which might destabilize the planet's climate by preventing material flows between the core and the ocean.
Possible ocean
At temperatures exceeding the critical point, liquids and gases stop being different phases and there is no longer a separation between an ocean and the atmosphere. It is unclear whether observations imply that a separate liquid ocean exists on K2-18b, and detecting such an ocean is difficult from the outside; its existence cannot be inferred or ruled out solely from the mass and radius of a planet.
The existence of a liquid water ocean is uncertain. Before the James Webb Space Telescope observations, a supercritical state of the water was believed to be more likely. JWST observations were initially considered to be more consistent with a fluid-gas interface and thus a liquid ocean - trace gases such as hydrocarbons and ammonia can be lost from an atmosphere to an ocean if it exists; their presence may thus imply the absence of an ocean-atmosphere separation. Subsequent work finds that a magma ocean may also capable of dissolving ammonia and explaining the observation results, but not to explain the observed carbon oxide concentrations. Whether the carbon oxide concentrations can be explained by a mini-Neptune/deep hydrogen atmosphere model is uncertain. Another paper suggests that a liquid water ocean model requires the presence of a biosphere in order to produce sufficient amount of methane.
Atmosphere and climate
Observations with the Hubble Space Telescope have found that K2-18b has an atmosphere consisting of hydrogen. The presence of water vapour is likely but with uncertainty, as James Webb Space Telescope observations indicating concentrations of less than 0.1%; this may be due to the JWST seeing a dry stratosphere as the atmosphere is thought to have an efficient cold trap. Ammonia concentrations appear to be unmeasurably low. JWST observations indicate that methane and carbon dioxide each make up about 1% of the atmosphere. Other carbon oxides were not reported; only an upper limit to their concentrations (a few percent) has been established. The atmosphere makes up at most 6.2% of the planet's mass, and its composition probably resembles that of Uranus and Neptune.
There is little evidence of hazes in the atmosphere, while evidence for water clouds, the only kind of clouds likely to form at K2-18b, is conflicting. If they exist, the clouds are most likely icy but liquid water is possible. Apart from water, ammonium chloride, sodium sulfide, potassium chloride and zinc sulfide could form clouds in the atmosphere of K2-18b, depending on the planet's properties. Most computer models expect that a temperature inversion will form at high elevation, yielding a stratosphere.
Evolution
High-energy radiation from the star, such as hard UV radiation and X-rays, is expected to heat the upper atmosphere and fill it with hydrogen formed through the photodissociation of water, thus forming an extended hydrogen-rich exosphere that can escape from the planet. The X-ray and UV fluxes that K2-18b receives from K2-18 are considerably higher than the equivalent fluxes from the Sun; the hard UV radiation flux provides enough energy to drive this exosphere to escape at a rate of about tons per second, too slow to remove the planet's atmosphere during its lifespan. Observations of decreases of Lyman alpha radiation emissions during transits of the planet may show the presence of such an exosphere; this discovery requires confirmation.
Alternative scenarios
Detecting atmospheres around planets is difficult, and several reported findings are controversial. Barclay et al. 2021 suggested that the water vapour signal may be due to stellar activity, rather than water in K2-18b's atmosphere. Bézard et al. 2020 proposed that methane may be a more significant component, making up about 3–10% while water may constitute about 5–11% of the atmosphere, and Bézard, Charnay and Blain 2022 proposed that the evidence of water is actually due to methane, although such a scenario is less probable.
Models
Climate models have been used to simulate the climate that K2-18b might have, and an intercomparison of their results for K2-18b is part of the CAMEMBERT project to simulate the climates of sub-Neptune planets. Among the climate modelling efforts made on K2-18b are:
Charnay et al. 2021, assuming that the planet is tidally locked, found an atmosphere with weak temperature gradients and a wind system with descending air on the night side and ascending air on the day side. In the upper atmosphere, radiation absorption by methane produced an inversion layer. Clouds could only form if the atmosphere had a high metallicity; their properties strongly depended on the size of cloud particles and the composition and circulation of the atmosphere. They formed mainly at the substellar point and the terminator. If there was rainfall, it could not reach the surface; instead it evaporated to form virga. Simulations with a spin-orbit resonance did not substantially alter the cloud distribution. They also simulated the appearance of the atmosphere during stellar transits.
Innes and Pierrehumbert 2022 conducted simulations assuming different rotation rates and concluded that except for high rotation rates, there is not a substantial temperature gradient between poles and equator. They found the existence of jet streams above the equator and at high latitudes, with weaker equatorial jets at the surface.
Hu 2021 conducted simulations of the planet's chemistry. They concluded that the photochemistry should not be able to completely remove ammonia from the outer atmosphere and that carbon oxides and cyanide would form in the middle atmosphere, where they could be detectable. The model predicts that a sulfur haze layer could form, extending through and above the water clouds. Such a haze layer would make investigations of the planet's atmosphere much more difficult.
Tsai et al. 2024 ran chemical and physical models. They found a prograde jet stream in the troposphere and a retrograde one above altitude, with thermally-driven circulation in-between the two. Tentative detection of dimethyl sulfide was reported. Several hydrocarbons can mask the dimethyl sulfide signal, and its production needs to exceed Earth's by a factor of 20 to be detectable. Such a rate is possible for a plausible ecosystem.
Habitability
Incoming stellar radiation amounts to , similar to the average insolation Earth receives. K2-18b is located within or just slightly inside the habitable zone of its star, – it may be close to but fall short of the runaway greenhouse threshold – and its temperature in the absence of a greenhouse is about to . Whether the planet is actually habitable depends on the nature of the atmosphere and the albedo of clouds and hazes; the deeper layers of the atmosphere may be too hot, while the water-containing layers might or might not have temperatures and pressures suitable for the development of life.
Microorganisms from Earth can survive in hydrogen-rich atmospheres, illustrating that hydrogen is no impediment to life. However, a number of biosignature gases used to identify the presence of life are not reliable indicators when found in a hydrogen-rich atmosphere, thus different markers would be needed to identify biological activity at K2-18b. According to Madhusudhan et al., several of these markers could be detected by the James Webb Space Telescope after a reasonable number of observations.
Discovery and research history
The planet was discovered in 2015 by the Kepler space telescope, and its existence was later confirmed with the Spitzer Space Telescope and through Doppler velocity techniques. Analyses of the transits ruled out that they were caused by unseen companion stars, by multiple planets or systematic errors of the observations. Early estimates of the star's radius had substantial errors, which led to incorrect planet radius estimates and the density of the planet being overestimated. The discovery of the spectroscopic signature of water vapour on K2-18b in 2019 was the first discovery of water vapour on an exoplanet that is not a Hot Jupiter and drew a lot of discussion.
K2-18b has been used as a test case for exoplanet studies. The properties of K2-18b have led to the definition of a "hycean planet", a type of planet that has both abundant liquid water and a hydrogen envelope. Planets with such compositions were previously thought to be too hot to be habitable; findings at K2-18b instead suggest that they might be cold enough to harbour liquid water oceans conducive to life. The strong greenhouse effect of the hydrogen envelope might allow them to remain habitable even at low instellation rates. K2-18b is probably the best known "hycean planet". Other, non-hycean compositions are possible, both habitable and uninhabitable.
There is some evidence of dimethyl sulfide (DMS) and methyl chloride being present in the atmosphere. The presence of DMS is a potential biosignature, as the bulk of the DMS in Earth's atmosphere is emitted from phytoplankton in marine environments, although further observation to confirm the presence of DMS and rule out a geological or chemical origin for the compound is required. Some scientists have voiced concerns about the statistical significance of the DMS signal at K2-18b, and how its putative detection might be understood in an environment different than Earth. In 2024, Wogan et al. suggested that the high methane concentrations might either imply the presence of methanogenic life or upwards mixing of gases from the deep interior, if the planet is too hot for life.
A podcast on the Planetary Society's website in January 2024 featured NASA astrophysicist Knicole Colón describing some of the scientific results from the observations of K2-18b by JWST. Data from JWST's MIRI instrument was expected to be gathered in January 2024 about which Colón said: "MIRI will be able to see additional features, absorption features from these molecules, and validate again, the presence of what we've seen and even the abundance." Colón also talks about the lack of evidence of water in the atmosphere: "The fact that the JWST data basically didn't find strong evidence of water in the atmosphere, that could indicate a couple things". Further, two observations using MIRI which lasted over 8 hours were taken on 25 & 26 April 2024 as part of JWST project 2722.
See also
Notes
References
Sources
External links
K2-18 b Confirmed Planet Overview Page, NASA Exoplanet Archive
NASA says distant planet could hold life after they spot signs of rare water ocean - MSN News
Exoplanets discovered in 2015
Transiting exoplanets
Super-Earths in the habitable zone
Exoplanets in the habitable zone
1
Leo (constellation)
Extraterrestrial water | K2-18b | [
"Astronomy"
] | 3,008 | [
"Leo (constellation)",
"Constellations"
] |
73,391,909 | https://en.wikipedia.org/wiki/Dicyclohexyl%20phosphorofluoridate | Dicyclohexyl phosphorofluoridate (DCFP), also known as TL-941 or T-1840, is an extremely toxic organophosphorus compound with powerful anticholinesterase action. It's a colorless liquid that is extremely resistant to hydrolysis. DCFP can be produced by reaction of cyclohexanol with phosphoryl dichloride fluoride.
See also
Diisopropyl phosphorofluoridate (DFP)
References
Acetylcholinesterase inhibitors
Phosphorofluoridates
Cyclohexyl compounds | Dicyclohexyl phosphorofluoridate | [
"Chemistry"
] | 137 | [
"Phosphorofluoridates",
"Functional groups"
] |
73,392,410 | https://en.wikipedia.org/wiki/Oxygen%20monofluoride | Oxygen monofluoride is an unstable binary inorganic compound radical of fluorine and oxygen with the chemical formula OF. This is the simplest of many oxygen fluorides.
Synthesis
OF is a radical that can be formed by thermal of photolytic decomposition of .
A reaction of fluorine and ozone:
Atmosphere
Oxygen- and fluorine-containing radicals like and OF occur in the atmosphere. These, along with other halogen radicals, have been implicated in the destruction of ozone in the atmosphere. However, the oxygen monofluoride radicals are assumed to not play as big a role in the ozone depletion because free fluorine atoms in the atmosphere are believed to react with methane to produce hydrofluoric acid which precipitates in rain.
References
Oxygen fluorides
Diatomic molecules
Free radicals | Oxygen monofluoride | [
"Physics",
"Chemistry",
"Biology"
] | 168 | [
"Oxygen fluorides",
"Molecules",
"Free radicals",
"Oxidizing agents",
"Senescence",
"Biomolecules",
"Diatomic molecules",
"Matter"
] |
73,392,987 | https://en.wikipedia.org/wiki/Iodine%20monoxide | Iodine monoxide is a binary inorganic compound of iodine and oxygen with the chemical formula IO•. A free radical, this compound is the simplest of many iodine oxides. It is similar to the oxygen monofluoride, chlorine monoxide and bromine monoxide radicals.
Synthesis
Iodine monoxide can be obtained by the reaction between iodine and oxygen:
Chemical properties
Iodine monoxide decomposes to its prime elements:
Iodine monoxide reacts with nitric oxide:
Atmosphere
Atmospheric iodine atoms (e.g. from iodomethane) can react with ozone to produce the iodine monoxide radical:
This process can contribute to ozone depletion.
References
Iodine compounds
Diatomic molecules
Oxides
Free radicals | Iodine monoxide | [
"Physics",
"Chemistry",
"Biology"
] | 154 | [
"Molecules",
"Free radicals",
"Oxides",
"Salts",
"Senescence",
"Biomolecules",
"Diatomic molecules",
"Matter"
] |
73,392,991 | https://en.wikipedia.org/wiki/Resilience%20%28power%20system%29 | Power resilience refers to a company's ability to adapt to power outages. Frequent outages have forced businesses to take into account the "cost of not having access to power" in addition to the traditional "cost of power". Climate-related issues have intensified the attention on energy sustainability and resilience. In the United States, electric utility firms have registered over 2500 significant power outages since 2002, with almost half of them (specifically 1172) attributed to weather events, including storms, hurricanes, and other unspecified severe weather occurrences. These incidents often lead to significant economic losses.
The Committee on Enhancing the Resilience of the Nation's Electric Power Transmission and Distribution System has developed strategies that seek to reduce the impact of large-scale, long-duration outages. Resilience is not just about preventing these outages from happening, but also limiting their scope and impact, restoring power quickly, and preparing for future events.
Some parts of the United States still rely on regulated, vertically integrated utilities, while others have adopted competitive markets. Efforts to improve resilience must take into account this institutional and policy heterogeneity.
The use of automation at the high-voltage level can improve grid reliability, but also introduces cybersecurity vulnerabilities. These "smart grids" use improved sensing, communication, automation technologies, and advanced metering infrastructure.
Distributed energy resources are rapidly growing in some states, but most U.S. customers will continue to depend on the large-scale, interconnected, and hierarchically structured electric grid. Therefore, strategies to enhance electric power resilience must consider a diverse set of technical and institutional arrangements and a wide variety of hazards. There is no single solution that fits all situations when it comes to avoiding, planning for, coping with, and recovering from major outages.
Definition
According to the US Department of Homeland Security (DHS), resilience is defined as "the ability to adapt to changing conditions and withstand and rapidly recover from disruption due to emergencies".
Causes
Power outages can be caused by various events, not just weather conditions. These events can be classified as either "low-frequency high-impact" or "high-frequency low-impact." Dealing with low-frequency high-impact events, also known as "large area long duration" events, is particularly challenging due to the significant devastation they cause over a vast area for an extended period. These events are generally unpredictable and occur unexpectedly, but advances in weather and disaster forecasting technology can offer some warning time to prepare for certain situations. Power outages can be caused by a wide range of factors, including natural disasters, cyberattacks, equipment failure, human error, and political instability. The impact of a disruptive event on the power system infrastructure can be significant, depending on the severity of the event and the condition of the infrastructure. For example, a severe storm can knock out power to a large geographical area, while a cyberattack on the communication systems can disrupt the entire power grid. Additionally, the interdependence of different infrastructures, such as energy, transportation, and communication, can exacerbate the impact of a disruptive event. Finally, the spatial and temporal impacts of a disruptive event can affect how quickly power can be restored, as well as the level of damage to the infrastructure. Overall, managing the risk of power outages requires a comprehensive approach that considers a range of potential disruptive events and their potential impact on the power system infrastructure.
Importance
Regardless of the reasons, one growing concern is that power outages result in economic losses and hardship for people who have become increasingly reliant on electricity for even basic comforts. So it is essential that electrical power systems (EPSs) around the world are resilient. A resilient EPS should ensure uninterrupted power supply, even in the face of minor faults and major disruptive events. It should be robust enough to be reliable and have the ability to predict and prepare for potential outages. Additionally, a resilient EPS should have a mechanism to quickly recover and restore power to critical establishments. However, while power system reliability is well-defined and has established metrics in the electricity sector, resiliency is often confused with reliability, despite some similarities.
According to the findings of National Academies report, the electric grid's smooth operation, which is organized in a hierarchical structure and tightly interconnected on a large scale, will remain crucial for ensuring dependable electric service to the majority of consumers over the next two decades.
Power disruptions are problematic for both consumers and the electric system itself. These disruptions are typically caused by physical damage to local parts of the system, such as lightning strikes, falling trees, or equipment failure. The majority of outages affecting customers in the United States are caused by events that occur in the distribution system, while larger storms, natural phenomena, and operator errors can cause outages across the high-voltage system. A variety of events, such as hurricanes, ice storms, droughts, earthquakes, wildfires, and vandalism, can lead to outages. When power goes out, life becomes more challenging, especially in terms of communication, business operations, and traffic control. Brief outages are usually manageable, but longer and wider outages result in greater costs and inconveniences. Critical services like medical care, emergency services, and communications can be disrupted, leading to potential loss of life. This report focuses on building a resilient electric system that minimizes adverse impacts of large outages, particularly blackouts that last several days or longer and extend over multiple areas or states, which are particularly problematic for a modern economy that depends on reliable electric supply.
Resilience vs reliability
Despite the efforts of utilities to prevent and mitigate large-scale power outages, they still occur and cannot be eliminated due to the numerous potential sources of disruption to the power system. It is somewhat surprising that such outages are not more frequent, considering the magnitude of the system and the potential for problems. However, the planners and operators of the system have made great efforts over many years to ensure that the electric system is engineered and operated with a high level of reliability. In recent times, there has been an increased emphasis on resilience as well. The North American Electric Reliability Corporation (NERC), which is responsible for developing reliability standards for the bulk power system, defines reliability in terms of two fundamental concepts.
Adequacy: Adequacy refers to the capability of the electricity system to meet the overall electricity demand and energy needs of end-users consistently, considering both planned and unexpected outages of system components that are reasonably anticipated.
Operating reliability: The capability of the overall electrical power system to endure unexpected disruptions, like electrical faults or unforeseen component failures due to credible emergencies, without experiencing unmanaged, widespread power outages or harm to machinery.
The system's reliability standards vary in practice, and while the bulk power system maintains a relatively high level of reliability throughout the United States, it cannot be made completely faultless due to its complexity as a "cyber-physical system." To ensure adequacy of electricity generation capability, a one-day-in-ten-years loss of load standard is commonly used, which means that the generation reserves must be sufficient to prevent voluntary load shedding due to inadequate supply from occurring more than once every ten years. However, with millions of intricate physical, communications, computational, and networked components and systems, the system is inherently complex and cannot attain perfect reliability.
Resilience and reliability are two different concepts. Resilience, as defined by the Random House Dictionary of the English Language, refers to the ability to return to the original state after being stretched, compressed, or bent. Moreover, resilience involves recovering from adversity, illness, depression, or other similar situations. It also encompasses the ability to rebound and cope with outages effectively by reducing their impacts, regrouping quickly and efficiently after the event ends, and learning to handle future events better.
See also
Resilient control systems
References
Engineering concepts | Resilience (power system) | [
"Engineering"
] | 1,662 | [
"nan"
] |
73,394,160 | https://en.wikipedia.org/wiki/Utah%20Social%20Media%20Regulation%20Act | S.B. 152 and H.B. 311, collectively known as the Utah Social Media Regulation Act, are social media bills that were passed by the Utah State Legislature in March 2023. The bills would collectively impose restrictions on how social networking services serve minors in the state of Utah, including mandatory age verification, and restrictions on data collection, algorithmic recommendations, and on when social networks may be accessible to minors.
The Act was intended to take effect in March 2024. However, following a lawsuit over the Act by NetChoice, the Utah attorney general stated in January 2024 that its implementation had been delayed to October 2024, but was likely to be repealed and amended. On September 10, 2024 Chief Judge Robert J. Shelby issued a written order granting a request from NetChoice, a tech industry group, for a preliminary injunction, meaning that Utah will be unable to enforce its social media law as litigation plays out. The law was appealed to the 10th Circuit on October 11, 2024 and is wanting a decision.
Provisions
The Act comprises two bills, S.B. 152 and H.B. 311, which respectively regulate access to social network accounts registered to minors, and impose obligations on social networking services to follow design practices that protect the privacy of minors. The bills would apply to social networks with more than 5 million active users in the United States.
Social networking services must verify the age of all users in the state of Utah, or else their account must be deleted. The Act does not specify a specific method of age verification. Users who are under 18 must have consent from a parent or guardian to open an account, and the parent must be able to have access to the account and its data for monitoring.
Unless required to comply with state or federal law, social networks are prohibited from collecting data based on the activity of minors, and may not display targeted advertising or algorithmic recommendations of content, users, or groups to minors. A social network must not allow minors to access the service between the hours of 10:30 p.m., and 6:30 a.m. without parental consent. H.B. 311 prohibits social networks from exposing features to minors that cause them to have an "addiction" to the platform; the service must perform quarterly audits, and may be sued by users for harms caused by providing "addictive" features; there is a rebuttable presumption of harm if the plaintiff is 16 or younger.
The bills prescribe fines of $2,500 per-violation for violations of the provisions of S.B. 152, and up to $250,000 in liabilities (plus fines of $2,500 per-user) for violations of the addiction rules.
History
The two bills were passed in early-March 2023, and signed by Governor Spencer Cox on March 23, 2023. Cox cited studies linking social media addiction to increases in depression and suicide among youth. They were originally intended to take effect on March 1, 2024. In the wake of a lawsuit in Arkansas by the trade association NetChoice over a similar bill, state senator and bill author Mike McKell stated that he planned to introduce amendments when the legislature resumed in 2024.
In December 2023, NetChoice filed a lawsuit in Utah seeking to block the Act, citing that its definition of a social network was too vague, and that it "restricts who can express themselves, what can be said, and when and how speech on covered websites can occur, down to the very hours of the day minors can use covered websites. The First Amendment, reinforced by decades of precedent, allows none of this." In regards to its age verification requirements, NetChoice argued that "it may not be enough to simply verify the age of whatever person may be listed on a form of identification (even if they have such a record) because that record may not accurately reflect who the individual actually is." The office of the attorney general stated that the state was "reviewing the lawsuit but remains intently focused on the goal of this legislation: Protecting young people from negative and harmful effects of social media use."
In January 2024, Attorney General Sean Reyes asked the court to delay a hearing over the bill, stating that its effective date had been delayed to October 2024, and that the legislature planned to repeal and replace the bills.
See also
Age appropriate design code
References
Internet law in the United States
Social media
Utah law
2023 in law
Child online safety laws | Utah Social Media Regulation Act | [
"Technology"
] | 911 | [
"Computing and society",
"Social media"
] |
73,394,958 | https://en.wikipedia.org/wiki/Tedral | Tedral, or theophylline/ephedrine/phenobarbital, is a medicine formerly used to treat respiratory diseases such as asthma, chronic obstructive lung disease (COPD), chronic bronchitis, and emphysema. It is a combination drug containing three active ingredients - theophylline, ephedrine, phenobarbital. This medication relaxes the smooth muscle of the airways, making breathing easier. The common side effects of Tedral include gastrointestinal disturbances, dizziness, headache and lightheadedness. However, at high dose, it may lead to cardiac arrhythmias, hypertension, seizures or other serious cardiovascular and/or central nervous system adverse effects. Tedral is contraindicated in individuals with hypersensitivity to theophylline, ephedrine and/or phenobarbital. It should be also used in caution in patients with cardiovascular complications, such as ischemic heart disease and heart failure and/or other disease conditions. It can cause a lot of drug–drug interactions. Therefore, before prescribing patient with Tedral, drug interactions profile should be carefully checked if the patient had other concurrent medication(s). Being used as a treatment option for respiratory diseases for decades, Tedral was withdrawn from the US market in 2006 due to safety concerns.
Medical uses
Tedral is an oral bronchodilator, which contains three active ingredients, including (1) theophylline, (2) ephedrine, and (3) phenobarbital. It was indicated for the symptomatic relief of asthmatic bronchitis, chronic bronchial asthma, COPD or other bronchospastic disorders. It was usually used as an added-on therapy in asthmatic patients with inadequate symptomatic control even with inhaled bronchodilators or inhaled corticosteroids. Besides, it could also be used as a prophylactic treatment for the prevention of asthmatic attacks.
Mechanism of action
There are three active ingredients in Tedral and they have different mechanisms of action.
Theophylline
Theophylline relaxes the bronchial smooth muscle and pulmonary artery smooth muscle. In addition, it also reduces the airway responsiveness to allergens, adenosine, methacholine, and histamine by two distinct mechanisms:
First, it acts as a competitive nonselective phosphodiesterase inhibitor to inhibit type III and type IV phosphodiesterase. The inhibition of type III and type IV phosphodiesterase leads to an increase in the concentration of intracellular cAMP, which then activates protein kinase A, and inhibits TNF-alpha, and leukotriene synthesis. Thereby, suppressing inflammation and innate immunity
Second, theophylline is also a nonselective adenosine receptor antagonist, which acts on A1, A2, and A3 receptors with almost the same affinity. This possibly explains theophylline's cardiac effects. Adenosine-mediated channels also enhance diaphragmatic muscle contractility by promoting calcium uptake.
Other mechanisms of action of theophylline have also been proposed. These include the inhibition of nuclear factor-kappaB prevents the translocation of the pro-inflammatory transcription factor (NF-kappaB) to the nucleus, thereby reducing the expression of known inflammatory genes in conditions such as COPD and asthma. Additionally, it increases the secretion of interleukin-10, which has broad anti-inflammatory effects. This process also decreases poly (ADP-ribose) polymerase-1 (PARP-1), promotes apoptosis of inflammatory cells, including T cells and neutrophils, and increases levels of histone deacetylase 2 by inhibiting phosphoinositide 3-kinase-delta.
Ephedrine
Ephedrine, a stereoisomer of pseudoephedrine, acts as a direct and indirect sympathomimetic amine. Its indirect mechanism makes it more unique than other sympathomimetic agents, for example, pseudoephedrine and phenylephrine.
It directly binds to both alpha and beta receptors. However, its primary mechanism of action is indirectly achieved by the inhibition of neuronal norepinephrine reuptake and displacement of more norepinephrine from storage vesicles. These actions prolong the presence of norepinephrine in the synapse for binding to postsynaptic alpha and beta receptors. Thereby, leading to alpha- and beta-adrenergic stimulation.
The stimulation of alpha-1-adrenergic receptors in vascular smooth muscle cells leads to an increase in systemic vascular resistance and, thus, systolic and diastolic blood pressure. Direct stimulation of beta-1 receptors by ephedrine and norepinephrine also increases cardiac chronotropy and inotropy. Lastly, stimulation of beta-2-adrenergic receptors in the lungs results in bronchodilation, however, the effect is less significant than those seen in the cardiovascular system.
Phenobarbital
Phenobarbital prolongs the time that chloride channels are open. Thereby, depressing the central nervous system. This is accomplished by acting on GABA-A receptor subunits. When phenobarbital binds to these receptors, the chloride ion gates open and remain open, allowing these ions to enter neuronal cells steadily. This action causes the cell membrane to hyperpolarize, leading to a raise in the action potential threshold.
Adverse effects
Theophylline
Due to the presence of theophylline in Tedral, the most common side effects of this drug include:
Gastrointestinal: nausea and vomiting, increased stomach acid secretion, and gastroesophageal reflux. These could be due to the inhibition of phosphodiesterase;
Central nervous system: headache, lightheadedness, dizziness, insomnia, restlessness, and irritability.
However, at high serum concentrations, some serious adverse effects may occur:
Cardiovascular: convulsions, cardiac arrhythmias. These could be to adenosine A1-receptor antagonism
Central nervous system: seizures, non-convulsive status epilepticus
Other adverse side effects include:
Neuromuscular and skeletal: tremor
Genitourinary: difficulty in micturition in males with prostatism, transient diuresis
Endocrine and metabolic: hypercalcemia in patients with concomitant hyperthyroid disease
Ephedrine
Ephedrine has both alpha- and beta-agonist effects. Owing to its sympathomimetic effect, the common side effects of Tedral include:
Gastrointestinal: nausea, vomiting
Cardiovascular: tachycardia, hypertension, irregular pulse, palpitations, bradycardia
Central nervous system: dizziness, anxiety, restlessness, and insomnia
Besides, ephedrine can cause cardiac arrhythmias. When ephedrine is used in long-term, the catecholamine excess can bring about contraction band necrosis of the myocardium, which predisposes the heart to ventricular arrhythmias.
Phenobarbital
Phenobarbital also results in the adverse effects of Tedral. The most common side effects caused by phenobarbital are dizziness, sedation, incoordination, and impaired balance. However, these adverse effects affect geriatric patients to a greater extent.
Concerning the adverse effects of phenobarbital after long-term usage, loss of appetite, depression, irritability, achiness in the bones, joints, or muscles, and liver damage may occur.
Other reported adverse reactions include:
Cardiovascular: hypotension, bradycardia, syncope
Central nervous system: confusion, agitation, somnolence, ataxia, hyperkinesia, hallucinations, anxiety, nightmares, thinking abnormality, psychiatric disturbance
Respiratory: hypoventilation, apnea
Gastrointestinal: nausea, vomiting, constipation
Dermatologic reactions: exfoliative dermatitis, toxic epidermic necrolysis, Stevens-Johnson syndrome (rare)
Contraindications
Theophylline
Because one of the active ingredients in Tedral is theophylline, Tedral is contraindicated if the patient has:
Hypersensitivity to xanthine derivatives
Coronary artery disease (cardiac stimulating effects of Theophylline may prove harmful)
Peptic ulcer
Concomitant use with ephedrine in children.
Ephedrine
Because Tedral also contains Ephedrine, Tedral is contraindicated for patients who have:
Acute hypertension
Tachycardia
Ephedrine raises both chronotropy and inotropy, increasing myocardial oxygen demand. Therefore, it has to be used in caution in patients with ischemic heart disease or heart failure. It should also be avoided in situations where tachycardia would be undesirable, for example aortic stenosis.
Ephedrine's alpha-adrenergic stimulation causes contraction of the smooth muscle at the base of the bladder, resulting in resistance to urine output. It is, therefore, the use of Tedral in patients with urinary retention and prostatic hyperplasia has to be cautious.
In addition, due to excessive norepinephrine availability at the synapse, which could induce a hypertensive crisis via the indirect sympathomimetic effect of ephedrine, Tedral should be avoided or used with caution within 14 days of monoamine oxidase inhibitor (MAOI) therapy.
Phenobarbital
Tedral is also composed of phenobarbital, therefore, it is contraindicated for individuals with:
Hypersensitivity to phenobarbital, barbiturates or any component of the formulation.
A history/manifest or latent porphyria
Liver impairment
Nephritic syndrome (at high dose)
A history of sedative-hypnotic drug addiction
Drug interactions
Theophylline
Due to the presence of theophylline, Tedral interacts with:
Adenosine
Allopurinol
Alcohol
Anti-psychotic agents
Antithyroid agents
Barbiturates
Benzodiazepines
Bupropion
Beta-2 agonists
Beta blockers
CYP1A2 inhibitors
CYP1A2 inducers
Cambendazole
Clarithromycin
Erythromycin
Interleukin-6 (IL-6) inhibiting therapies
Iohexol
Levothyroxine
Methotrexate
Quinine
Verapamil
Zafirlukast
Theophylline cause interactions of Tedral with the following diseases:
Peptic ulcer disease (PUD)
Renal dysfunction
Seizure disorders
Ephedrine
Because of the presence of ephedrine, Tedral interacts with:
Alkalinizing agents
Alpha-1 blockers
Beta blockers
Cannabinoid-containing products
Carbonic anhydrase inhibitors
Clonidine
Clozapine
Inhalation Anesthetics
Iobenguane radiopharmaceutical products
Monoamine oxidase inhibitors
Quinidine
Serotonin / norepinephrine reuptake inhibitors
Sympathomimetics
Tricyclic antidepressants
Urinary acidifying agents
Since ephedrine is one of the active ingredients in Tedral, Tedral interacts with the following disease:
Cardiovascular disease
Benign prostatic hyperplasia (BPH)
Diabetes
Phenobarbital
Since Tedral contains phenobarbital, it interacts with:
Acetaminophen
Blood pressure lowering agents
Cannabinoid-containing products
CNS depressants
Doxycycline
Local anesthetics
Magnesium Sulfate
Procarbazine
Quinine
With phenobarbital being one of the active ingredients in Tedral, Tedral interacts with the following disease:
Acute alcohol intoxication
Drug dependence
Liver disease
Porphyria
Rash
Respiratory depression
Cardiovascular
Prolonged hypotension
Renal dysfunction
History
The history of Tedral can be traced back to the early 20th century when theophylline was first isolated from tea leaves and later found to have bronchodilator properties. In the 1920s and 1930s, ephedrine was introduced as a treatment for asthma and other respiratory conditions due to its bronchodilating effect and ability to increase blood flow to the lungs.
The combination of theophylline and ephedrine was first used in the 1940s as a treatment for asthma, and the addition of a barbiturate such as pentobarbital or phenobarbital was later added to enhance the sedative effects of the medication and improve patient compliance.
Tedral was first marketed by the pharmaceutical company Eli Lilly and Company in the 1950s as a treatment for asthma and other respiratory conditions, and later sold to Novartis Pharmaceuticals Corporation. It was widely used throughout the 1960s and 1970s, but its popularity declined in the 1980s due to the development of newer, more effective medications for asthma and COPD, such as inhaled corticosteroids, long-acting beta-agonists, leukotriene modifiers and immunomodulators.
Tedral was withdrawn from the US market in 2006 due to safety concerns related to the use of ephedrine. The US Food and Drug Administration (FDA) had previously issued warnings about the use of ephedrine-containing products due to their potential for serious side effects, including heart attack, stroke, and death. In response, many pharmaceutical companies voluntarily removed their ephedrine-containing products from the market. In the case of Tedral, its manufacturer, Novartis Pharmaceuticals Corporation, voluntarily withdrew the medication from the market in 2006 after the FDA issued a warning letter to the company citing safety concerns related to the use of ephedrine.
See also
Theophylline/ephedrine
References
Bronchodilators
Combination asthma drugs
Combination COPD drugs
Withdrawn drugs | Tedral | [
"Chemistry"
] | 2,933 | [
"Drug safety",
"Withdrawn drugs"
] |
73,395,605 | https://en.wikipedia.org/wiki/Tecno%20Spark%2010 | Tecno Spark 10C, Tecno Spark 10, Tecno Spark 10 Pro and Tecno Spark 10 5G are Android-based smartphones manufactured, released and marketed by Tecno Mobile as part of Tecno Spark 10 series. The devices serve as successors to Tecno Spark 9 series.
The Spark 10C, Spark 10, Spark 10 Pro and Spark 10 5G is an upgraded version of Spark 9 series, coming with different features, including the processor and design. The phone has received generally favorable reviews, with critics mostly noting the design and the display. Critics, however, criticized the lack of stereo speakers and video stabilization.
Specifications
Hardware
The Spark 10C and Spark 10 feature a 720p resolution, while the Spark 10 Pro and Spark 10 5G feature a 1080p resolution. The Spark 10C, Spark 10 and Spark 10 5G phones feature a display size of 6.6-inches, while the Spark 10 Pro features a display size of 6.8-inches. The Spark 10C comes with a UNISOC T606 SoC, the Spark 10 comes with a MediaTek Helio G37 SoC, the Spark 10 Pro comes with a MediaTek Helio G86 SoC and the Spark 10 5G comes with a MediaTek Dimensity 6020 SoC. The Spark 10C comes with 4/8 GB of RAM, while the Spark 10, Spark 10 Pro and Spark 10 5G come with 8 GB of RAM. The Spark 10C and Spark 10 come with 128 GB of storage, the Spark 10 Pro comes with 128/256 GB of storage and the Spark 10 5G comes with 256 GB of storage. All of the devices feature the ability to use a microSD. All the devices come with a battery capacity of 5000 mAh, with the Spark 10, Spark 10 Pro and Spark 10 5G supporting fast charging at 18 watts. The Spark 10C features a 16-megapixel main camera, while the Spark 10, Spark 10 Pro and Spark 10 5G feature a 50-megapixel main camera. The Spark 10C, Spark 10 and Spark 10 5G feature an 8-megapixel front camera, while the Spark 10 Pro features a 32-megapixel front camera.
Software
The Spark 10C runs on Android 12 with HiOS 12, while the Spark 10, Spark 10 Pro and Spark 10 5G run on Android 13 with HiOS 12.6, different from the versions found on Spark 9 and Spark 9 Pro.
The HiOS 12 come bundled with a slew of apps like IDA Engine 3.0, Aurora Engine, Ella 2.0 and Welife, among others.
Reception
Mehedi Hasan from United News of Bangladesh praised the Spark 10 Pro for its display, selfie camera and processor compared to the Spark 9 Pro, while noting that "it's refreshing to see a phone that prioritizes the needs of selfie enthusiasts".
Sern Wen from Gizmochina praised the Spark 10 Pro for being a selfie focused device while noting that the phone "doesn’t lag behind other phones in every aspect of its specs".
Nikos Papanikolopoulos from Gizchina awarded the Spark 10 Pro 8.2 stars out of 10, noting that the device is a "selfie phone for those who are on a tight budget". Praise was directed towards the display and selfie camera. However, the lack of electronic image stabilization and the sound of the video recording were criticized.
Valor Reviews praised the Spark 10 Pro for its display and design, while noting that "the build quality is great and the design is eye-catching". However, the lack of stereo speakers and video stabilization were criticized.
References
Android (operating system) devices
Phablets
Mobile phones introduced in 2023
Tecno smartphones | Tecno Spark 10 | [
"Technology"
] | 786 | [
"Crossover devices",
"Phablets"
] |
73,396,228 | https://en.wikipedia.org/wiki/Computing%20in%20Science%20%26%20Engineering | Computing in Science & Engineering (CiSE) is a bimonthly technical magazine published by the IEEE Computer Society. It was founded in 1999 from the merger of two publications: Computational Science & Engineering (CS&E) and Computers in Physics (CIP), the first published by IEEE and the second by the American Institute of Physics (AIP). The founding editor-in-chief was George Cybenko, known for proving one of the first versions of the universal approximation theorem of neural networks.
The magazine is interdisciplinary and covers topics such as numerical simulation, modeling, and data analysis and visualization. CiSE aims to provide its readers with practical information on the latest developments in computational methods and their applications in science and engineering. Computing in Science & Engineering publishes peer-reviewed technical articles, special issues, editorials, and departments (regular columns).
Notable articles
One of the most notable articles published in CiSE is "Matplotlib: A 2D Graphics Environment," by the late John D. Hunter. It shows more than 22 thousand full-text views and more than 17 thousand citations in IEEE Xplore, and more than 27 thousand citations in Google Scholar (checked August 14, 2023). A very popular department article is "What is the Blockchain?" by member of the editorial board Massimo DiPierro. Other notable articles include "Python for Scientific Computing" by Travis Oliphant, which has more than 15 thousand views in Xplore, and "The NumPy Array: A Structure for Efficient Numerical Computation," by Stefan van der Walt et al., with nearly 7 thousand citations and 12 thousand views in Xplore.
The winner of the CiSE 2021 Best Paper Award was "Jupyter: Thinking and Storytelling With Code and Data," by Brian E. Granger and Fernando Pérez.
Notable editors
Among the editors emeritus, who served close to twenty years in the editorial board, is Jack Dongarra, Distinguished Professor of Computer Science at the University of Tennessee, and recipient of the IEEE Computer Society 2020 Computer Pioneer Award, and the 2021 ACM Alan Turing Award, among many other accolades. Cleve Moler, chairman and cofounder of MathWorks, was area editor for Software and a member of the editorial board from 1999. The precursor magazine, IEEE Computational Science & Engineering (CS&E), was founded by Ahmed Sameh, known for his contributions to parallel algorithms in numerical linear algebra, who remained in the CiSE board for several years. Dianne O'Leary, emeritus professor of computer science at the University of Maryland, was editor of the Your Homework Assignment column for several years starting on 2003. She compiled and expanded her columns into a book, "Scientific Computing with Case Studies," published by SIAM in 2009.
References
Academic journals of the United States
Electrical and electronic engineering journals
English-language journals | Computing in Science & Engineering | [
"Engineering"
] | 581 | [
"Electrical engineering",
"Electronic engineering",
"Electrical and electronic engineering journals"
] |
73,396,817 | https://en.wikipedia.org/wiki/Estradiol/raloxifene | Estradiol/raloxifene (E2/RLX) is a tissue-selective estrogen complex (TSEC) which was studied for potential use in menopausal hormone therapy but was never marketed. Today, E2/RLX is not generally used due to concerns of endometrial hyperplasia.
See also
List of combined sex-hormonal preparations
References
Abandoned drugs
Combination sex hormone drugs | Estradiol/raloxifene | [
"Chemistry"
] | 91 | [
"Drug safety",
"Abandoned drugs"
] |
73,397,196 | https://en.wikipedia.org/wiki/X%20Herculis | X Herculis is a star about 400 light years from the Earth in the constellation Hercules. It is a semiregular variable star, ranging in brightness from magnitude 5.8 to 7.0 over a period of about 102 days. It is rarely visible to the naked-eye, but can be seen easily with a small telescope, or binoculars.
X Herculis was discovered to be a variable star by John Gore, in 1890. Variability was quickly confirmed by two other observers. Although it was known by a variety of names at the time of the discovery of its variability, the star was immediately given the variable star designation X Herculis. Subsequent studies found periods of , and days in the light curve.
X Herculis is an oxygen-rich AGB star, losing mass at a rate of per year via a stellar wind. In 1986 Benjamin Zuckerman et al. detected the J=2→1 line of carbon monoxide (CO) in the stellar wind. The shape of the CO line profile shows that the wind has two components, one of which leaves the vicinity of the star at a speed of km/sec, and another which has a speed of km/sec. The slow wind appears to arise from a disk surrounding, and possibly orbiting X Herculis. The faster wind appears to arise from a bipolar outflow. The stellar winds have produced a large circumstellar shell. Studies of such a shell using molecular spectroscopy can only probe the inner region of the shell, because as the stellar wind expands and becomes less dense, the molecules in the gas are dissociated by the interstellar radiation field. Luckily, the high galactic latitude (48°) of X Herculis allows the 21 cm line of atomic hydrogen (HI) to be observed without contamination from unrelated material in the galactic plane. Lynn Matthews et al. mapped the HI shell, and found it to be at least 0.8 light years across, with a comet-like tail produced by the motion of the star through the interstellar medium (ISM). The mass of HI in the shell is about , but the total mass of the shell may be significantly larger, because much of the hydrogen may be in molecular form.
Near-infrared radiation from X Herculis was detected in the first Two-Micron Sky Survey, published in 1969. The stellar winds from AGB stars contain dust and that dust was detected in the far-infrared by the IRAS satellite. The dust emission was resolved by IRAS, showing the same large shell that is seen in HI observations. X Herculis is moving through the ISM at a speed of 108 km/sec. Herschel Space Observatory images show a bow shock in the region where the stellar wind collides with the ISM, but they show no evidence of the bipolar flow seen in high resolution maps of the molecular line emission.
References
Hercules (constellation)
Herculis, X
144205
78574
Semiregular variable stars
M-type giants | X Herculis | [
"Astronomy"
] | 615 | [
"Hercules (constellation)",
"Constellations"
] |
77,724,966 | https://en.wikipedia.org/wiki/Orgasmic%20epilepsy | Orgasmic epilepsy is a rare form of epilepsy that involves auras in which spontaneous orgasms occur. Due to their rarity and sensitive nature, they have mostly been reported as single cases and case series. A broader category is epilepsy with sexual auras generally. There are similarities and overlap of orgasmic epilepsy with ecstatic epilepsy and certain other forms of epilepsy. Orgasmic seizures were first reported in 1960 and a number of additional cases have been reported since then.
References
Epilepsy
Epilepsy types
Euphoriants
Human sexuality
Orgasm
Rare diseases
Symptoms and signs | Orgasmic epilepsy | [
"Biology"
] | 126 | [
"Human sexuality",
"Behavior",
"Sexuality",
"Human behavior"
] |
77,725,324 | https://en.wikipedia.org/wiki/CIA%20fake%20vaccination%20campaign%20in%20Pakistan | During the manhunt for Osama bin Laden, the CIA ran a covert operation utilizing a fake hepatitis vaccine program in Pakistan to illicitly collect blood samples to confirm the presence of bin Laden or his family. The CIA did not administer hepatitis vaccines, and instead planned to compare DNA samples collected from the program with the DNA of bin Laden's sister, who died in Boston in 2010.
The program was ultimately unsuccessful. It led to the arrest of a participating physician, Shakil Afridi, and was widely ridiculed as undermining public health. The program is credited with increasing vaccine hesitancy in Pakistan and a rise in violence against healthcare workers for being perceived as spies. The rise in vaccine hesitancy following the program led to the re-emergence of polio in Pakistan, with Pakistan having by far the largest number of polio cases in the world by 2014.
Aftermath
In September of 2012, after working for 30 years in Pakistan, Save the Children was expelled.
In 2011, the program was condemned by Doctors without Borders. In Feb 2012, the program was condemned by the non-governmental organization InterAction. On January 6, 2013, the deans of twelve American schools of public health sent a letter to Obama condemning the program.
On May 16, 2014, Lisa Monaco responded that vaccine programs would be excluded from espionage:
See also
CIA activities in Pakistan
CIA transnational health and economic activities
References
CIA activities in Pakistan
United States espionage scandals and incidents
Pakistan military scandals
Polio
Vaccine controversies
2011 scandals
Covert operations
Health disasters in Pakistan
2010s in Pakistan
Osama bin Laden
Pakistan–United States relations
Central Intelligence Agency controversies
Vaccine hesitancy | CIA fake vaccination campaign in Pakistan | [
"Chemistry",
"Biology"
] | 332 | [
"Vaccination",
"Drug safety",
"Vaccine controversies"
] |
77,725,717 | https://en.wikipedia.org/wiki/Garko%2C%20Gombe%20State | Garko is a ward located in Gombe State, Nigeria's Akko Local Government Area. About 12.7 kilometers, or 7.9 miles, from Garko. The distance is roughly 421 kilometers / 262 mi from Garko to Abuja, the capital of Nigeria.
The Postcode of the area is 771104.
Gallery
References
Town
Populated places in Gombe State
Climate and weather statistics
Environment articles by quality
Nigeria geography stubs
Gombe State
Climate of Africa | Garko, Gombe State | [
"Physics"
] | 101 | [
"Weather",
"Physical phenomena",
"Climate and weather statistics"
] |
77,727,630 | https://en.wikipedia.org/wiki/List%20of%20Wolf-Rayet%20stars | This is a list of Wolf-Rayet stars, in order of their distance from Earth.
List
Milky Way Galaxy
Magellanic Clouds
The Large Magellanic Cloud (LMC) is around 163 kly distant and the Small Magellanic Cloud (SMC) is around 204 kly distant.
Andromeda Galaxy and Triangulum Galaxy
The Andromeda Galaxy (M31) is 2.5 Mly distant and the Triangulum Galaxy is around 3.2 Mly distant
Other Galaxies
See also
List of luminous blue variable stars
List of O-type stars
References
Wolf–Rayet stars
Lists of stars
Star systems
Lists by distance
O-type stars
B-type stars | List of Wolf-Rayet stars | [
"Physics",
"Astronomy"
] | 140 | [
"Lists by distance",
"Physical quantities",
"Distance",
"Astronomical objects",
"Star systems"
] |
77,727,764 | https://en.wikipedia.org/wiki/4-HO-TMT | 4-HO-TMT, or 4-OH-TMT, also known as 4-hydroxy-N,N,N-trimethyltryptammonium or as dephosphorylated aeruginascin, is a substituted tryptamine derivative and the active form of aeruginascin (4-PO-TMT), analogously to how psilocin (4-HO-DMT) is the active form of psilocybin (4-PO-DMT). 4-HO-TMT is closely related to bufotenidine, the N-trimethyl analogue of serotonin.
Like psilocin, 4-HO-DMT shows affinity for the serotonin 5-HT1A, 5-HT2A, and 5-HT2B receptors. However, its affinities for these receptors are lower than those of psilocin (by 8-, 6-, and 26-fold, respectively). Additionally, in another study, the value of 4-HO-TMT in activating the serotonin 5-HT2A receptor was 324-fold lower than that of psilocin (6800 and 21nM, respectively). Similarly to psilocin, 4-HO-TMT does not bind to the serotonin 5-HT3 receptor. This was in contrast to predictions, as the related compound bufotenidine is a strong and selective serotonin 5-HT3 receptor agonist.
4-HO-TMT is a quaternary trimethyl ammonium compound, and as a result, is less likely to be able to cross the blood–brain barrier (BBB) and enter the central nervous system than other tryptamines. Accordingly, 4-HO-TMT showed no ability to cross an artificial BBB-like membrane in a study. In rodents, 4-HO-TMT showed no head-twitch response (a behavioral proxy of psychedelic effects), hypolocomotion, or hypothermia, in contrast to psilocin and norpsilocin, but similarly to aeruginascin.
A synthetic prodrug of 4-HO-TMT, 4-AcO-TMT, has been developed. It is analogous to psilacetin (4-AcO-DMT), a prodrug of psilocin.
References
External links
4-OH-TMT+ - isomer design
Dimethylamino compounds
Human drug metabolites
Hydroxyarenes
Mycotoxins
Non-hallucinogenic 5-HT2A receptor agonists
Peripherally selective drugs
Serotonin receptor agonists
Tryptamine alkaloids
Quaternary ammonium compounds | 4-HO-TMT | [
"Chemistry"
] | 579 | [
"Tryptamine alkaloids",
"Chemicals in medicine",
"Alkaloids by chemical classification",
"Human drug metabolites"
] |
77,728,654 | https://en.wikipedia.org/wiki/EFEDSJ0828%E2%80%930139 | Hyperluminous quasar discovered by a Japanese team of astronomers, led by Yoshiki Toba (NAOJ), among the sources identified by eROSITA instrument, on board the Spektr-RG spacecraft. This quasar, emitting from Radio to X-ray, would have a redshift z=1.62. The mass of SMBH in the core of the host galaxy, would be pair to 620 million solar masses. By the researchres, the IR luminosity of this object would be 68 trillion solar luminosity, with an Eddington ratio of 3.6. Tha SFR would be as high as a thousand solar masses/yr. Toba and colleagues have used facilities at Seimei Telescope, and at the James Clerk Maxwell Telescope (JCMT) for this study.
References
Quasars | EFEDSJ0828–0139 | [
"Astronomy"
] | 178 | [
"Galaxy stubs",
"Astronomy stubs"
] |
77,728,984 | https://en.wikipedia.org/wiki/List%20of%20luminous%20blue%20variable%20stars | This is a list of luminous blue variable stars in order of their distance from Earth.
List
Milky Way galaxy (confirmed LBVs)
Milky Way galaxy (candidate LBVs)
Magellanic Clouds
The Large Magellanic Cloud (LMC) is around 163 kly distant and the Small Magellanic Cloud (SMC) is around 204 kly distant
Andromeda Galaxy and Triangulum Galaxy
The Andromeda Galaxy (M31) is 2.5 Mly distant and the Triangulum Galaxy is around 3.2 Mly distant
Single LBV Galaxies
See also
List of Wolf-Rayet stars
List of O-type stars
References
Lists of stars
Star systems
Lists by distance | List of luminous blue variable stars | [
"Physics",
"Astronomy"
] | 140 | [
"Lists by distance",
"Physical quantities",
"Distance",
"Astronomical objects",
"Star systems"
] |
77,729,754 | https://en.wikipedia.org/wiki/Rodentology | Rodentology is a branch of mammalogy for the study of rodents by a rodentologist. The scientific group of rodents would include, but is not limited to, mice, rats, squirrels, etc. From the perspective of zoology, it investigates the behaviour, biology and classification of various rodent species. The study of rodents includes their genetics and their place in the ecosystem. Furthermore, research may be conducted into pest control, disease vector, disease management in agriculture, environmental degradation, globalization and disease, effects on human society and pathogen transmission.
Benefits to society
Rodentology may benefit human society with contributions to agriculture, balance of nature, food protection, global health, human health, infrastructure protection, integrated pest management, public health and scientific research.
References
External links
Biological pest control
Mammalogy
Pest control
Pest control techniques
Rodents
Rodents and humans | Rodentology | [
"Biology"
] | 169 | [
"Pests (organism)",
"Pest control"
] |
77,730,747 | https://en.wikipedia.org/wiki/Delorme%201 | Delorme 1 (2MASS J01033563-5515561) is a binary star with a planetary-mass companion (PMC) or protoplanet in a circumbinary orbit. The PMC is notable for showing signs of accretion, despite being 30-45 Myr old, making it similar to Peter Pan disks. These disks show characteristics of a gas-rich disk at unexpected high ages.
The binary system
The star was resolved in 2013 with the Very Large Telescope NACO instrument by Delorme et al. A spectrum of the binary was taken with GMOS at Gemini South, which showed a spectral type of M5.5/M6 and strong Hydrogen-alpha emission. The astrometry showed that this star belongs to the Tucana-Horologium association. The binary is separated by around 12 astronomical units (AU). In 2014 Riedel et al. found a better match with the Carina association, which has a similar age as Tuc-Hor. They also found the system to be over-luminous, which might either hint at a younger age or further multiplicity. Other searches do, however, find a better match with Tuc-Hor. Because the Washington Double Star Catalog named the binary ** DLR 1 after the first author of the discovery paper in 2013, Eriksson et al. suggested the name Delorme 1 for the binary. The binary is named after Philippe Delorme.
The circumstellar companion
The binary companion was discovered in 2013 as an object with a mass between 12 and 14 and a separation of 84 AU from the central binary. It had a spectrum similar to early L-dwarfs, but redder than field L-dwarfs. In 2020 Eriksson et al. discovered Hydrogen-alpha, -beta and Helium I lines from Delorme 1 (AB)b using MUSE. This is seen as a clear sign of accretion on a planetary-mass object. The spectral type of this object was determined to be L0 with very low gravity due to stronger than expected vanadium oxide absorption. H-alpha can be influenced by chromospheric activity, complicating its interpretation. Betti et al. discovered Paschen and Brackett lines in Delorme 1 (AB)b in the near-infrared, using TripleSpec at SOAR. These observations are in agreement with planetary-shock accretion. In 2023 Ringqvist et al. observed Delorme 1 (AB)b with the VLT UVES, detecting neutral hydrogen in the ultraviolet. Both near-infrared and ultraviolet observations show an accretion rate of about (about 1.2 to 2.3 the mass of 10 Hygiea per year). The circumplanetary disk that fuels this accretion around Delorme 1 (AB)b is not detected (as of August 2024). The planet and the star were observed with MIRI/IFU in August 2023, which should reveal any disk around the planet or star in a future work.
Delorme 1 (AB)b has been called a protoplanet candidate and a super-Jupiter. The researchers found that the high accretion is in better agreement with a formation via disk fragmentation, hinting that it might have formed from a circumstellar disk. Giant planets and brown dwarfs are thought to form via disk fragmentation in rare cases in the outer regions of a disk (r>50 AU). Teasdale et al. modelled three formation scenarios in which the planet could have formed. In the first two scenarios the planet forms in a massive disk via gravitational instability. The first two scenarios produce planets that have accretion and separation comparable to the observed ones, but the resulting planets are more massive than Delorme 1 (AB)b. In a third scenario the planet forms via core accretion in a less massive disk much closer to the binary. In this third scenario the mass and accretion are similar to the observed ones, but the separation is smaller.
References
Exoplanets discovered in 2013
Binary stars
Phoenix (constellation)
Protoplanets | Delorme 1 | [
"Astronomy"
] | 857 | [
"Phoenix (constellation)",
"Constellations"
] |
77,731,537 | https://en.wikipedia.org/wiki/Desh%20Pal%20S.%20Verma | Desh Pal S. Verma is a plant cell and molecular biologist and currently a Professor Emeritus at the Department of Molecular Genetics, Ohio State University. Verma graduated with Master' degree from Agra University in 1974 and completed his PhD in 1970 from University of Western Ontario Canada. Verma did postdoctoral work at the Fox Chase Cancer Center, Philadelphia 1970–1972 and then moved to McGill University and became an Assistant Professor in 1974.
He has been a member of several interdisciplinary graduate programs including molecular cellular and developmental biology, applied plant sciences, plant pathology, and biochemistry programs.
Career
Desh Pal S. Verma began his career at McGill University, Canada (1974–1987) where he received National Research Council's Steacie Award given by the Governor General of Canada Edward Schreyer in 1981. He was later elected as the Fellow of the Royal Society of Canada and the member of the Canadian Academy of Sciences in 1986. In 1987 Verma was a Senior Editor for the International Society of Molecular Plant-microbe Interactions (IS-MPI) which later developed into the Molecular Plant-Microbe Interactions Journal of which he was a co-editor. In 1988 he was appointed as a Professor and Associate Director of the Biotechnology Center at the Department of Molecular Genetics at The Ohio State University. In 1996, he received a Docteur Honoris Causa from the Universite de Picardie, France. In 2003, he was inducted as a Fellow of The World Academy of Sciences in Italy. During his tenure at The Ohio State University he was a member of several interdisciplinary graduate programs including molecular cellular and developmental biology, applied plant sciences, plant pathology, and biochemistry. In 2021 he became a Professor Emeritus.
Verma's work in the field of biotechnology includes isolation of the first plant mRNA, cloning the first plant gene, discovery of many new genes named as Nodulins including the one encoding Uricase based on which a similar enzyme was isolated from raspberry which is being used by a biotechnology company to make a recombinant enzyme for the treatment of hyperuricemia.
He has trained over 165 graduate students, postdoctoral fellows and visiting scientists in his labs both in Canada and USA. He is currently engaged with a biotechnology company in USA in developing Lectins as molecular tools to identify cancer biomarkers and building glycoGPT, an AI based platform for glycobiology.
Select publications
Verma has published over 220 research papers, edited 11 books and has been an international speaker for the last 50 years. He has consulted with many international companies and advised the Planning Commission of India (currently NITI Aayog) from 2006–2011 in the area of agriculture biotechnology.
Baulcombe, D. and D.P.S. Verma (1978). Preparation of a complementary DNA for leghemoglobin and direct demonstration that leghemoglobin is encoded by the soybean genome. Nucl. Acids Res. 5: 4141-4153.
References
Living people
Molecular biologists
Cell biologists
Ohio State University faculty
Year of birth missing (living people) | Desh Pal S. Verma | [
"Chemistry"
] | 628 | [
"Molecular biologists",
"Biochemists",
"Molecular biology"
] |
77,732,666 | https://en.wikipedia.org/wiki/Social%20conflict%20in%20ants | In ants, social conflicts, sex conflicts, or caste conflicts can exist. These conflicts occur within the same colony or supercolony at various levels: on an individual scale, between two or more specific ants; on the scale of sex, between males and females; or on the scale of different castes, between queens and workers. They should not be confused with ant wars, which involve different and opposing colonies or supercolonies. Even as larvae, ants can engage in conflicts, typically at the scale of the entire colony, against other individuals within the same colony. These social conflicts may involve the male-to-female ratio within the colony. For example, in some species, male and female larvae may engage in mutual cannibalism, often with males being more aggressive, to increase their chances of survival and growth. Conflicts can also arise between workers and queens over the management of the larvae produced; workers may favor female larvae, while queens increase the ratio of males they lay. These conflicts are generally more intense depending on the degree of relatedness between the ants involved. For instance, ants belonging to the same supercolony or a polygynous colony - meaning a colony with several queens - tend to engage more against workers or larvae from a queen different from their own. In species and colonies operating under the gamergate system, where each worker is a potential queen, ants engage in battles to become the sole or one of the few worker-queens capable of laying eggs.
The study of such conflicts tends to show that ants can act to favor their individual interests, and not just the colony or queen's interests. It also tends to shed in light, in some cases, the fact that ant colonies can be highly structured with hierarchies and power relationships between the various ants.
Terminology
The use of the term "social conflicts" or "caste conflicts" is documented in the scientific literature.
Background
Ant societies, being highly structured based on the sex of the individuals and their caste (males, workers, queens), generally see conflicts organized and developed around these aspects. While these conflicts often occur on an individual level, they are frequently shared by many members of the colonies, leading to broader dynamics. Thus, conflicts regularly revolve around determining the male-to-female ratio within the colonies. If those oppositions seem to involve genetical factors in a lot of occurrences, it doesn't seem to be always the case. This is also possible since ant colonies, in some cases, seem to be highly structured with hierarchies and power relationships between the different individuals.
Processes
Larva and worker-queen conflicts
In ants, conflicts exist even at the larval stage. In certain ant species, male and female larvae tend to cannibalize other larvae. This behavior increases their own chances of survival and is generally more prevalent among male larvae, who try to enhance their growth and survival prospects. This behavior is more common toward larvae originating from a different queen within the same colony or supercolony. Conflicts over larval management can also extend to adult ants. Queens may tend to aim for a male-to-female ratio of 0.5 when laying eggs, while workers seek to adjust this ratio toward a higher proportion of worker ants, which are more beneficial for the pragmatic management of the colony. This creates a constant power struggle between the queens and the workers over larval management. Typically, the queen responds to this conflict by laying a higher ratio of male eggs, while the workers either neglect or, to a lesser extent, cannibalize the male larvae, focusing more on caring for worker larvae. In studies conducted on colonies exhibiting such behaviors, workers seem to prevail in most cases, although this is not always the rule.
In some ant species, including in the genus Formica, larvae may attempt to become queens by gaining access to more significant nutritional resources, which explains why such individual conflicts can occur among larvae. These larvae engage in various strategies to increase their nutritional intake, including begging for food or cannibalizing other larvae. The queen or queens of the colony can also engage in pheromonal strategies to try to control the nutritional activities carried out by the workers and influence their choices regarding how to feed the larvae.
Individuality and hierarchies
In general, the issue of conflicts within ant communities challenges the notion that they lack individuality. Indeed, numerous conflicts, which can even escalate to violence and death, demonstrate a form of individuality among ants. This is clearly shown as ants seem to often follow their own respective interests in the advent of such oppositions or conflicts. They tend to show selfishness behavior in those cases. In some cases, such as in Temnothorax unifasciatus, where workers can lay eggs alongside the queen, it seems that ants policing other ants would be a selfish behavior taken by the workers to increase their own chances of becoming egg-laying workers afterwards. It tends to shed light on the hierarchical structures that can exist in ant colonies, where ants organize themselves into various ranks and exhibit complex power relationships.
Gamergates
In ant colonies using the gamergate system, where all workers have a spermatheca and thus the potential to become egg-laying individuals, conflicts are much more violent and are a regular part of colony management. Workers may engage in contests and confrontations to determine who will have the right or possibility to lay eggs. In these colonies, such disputes are common and are crucial for the survival of the community.
References
Conflict
Dispute resolution
Military ethics
Violence
Conflicts
Ants | Social conflict in ants | [
"Biology"
] | 1,124 | [
"Behavior",
"Aggression",
"Human behavior",
"Violence"
] |
77,733,110 | https://en.wikipedia.org/wiki/List%20of%20commercial%20failures%20in%20computing | Certain products related to computing, such as hardware, software, and smartphones, were mass-marketed and highly anticipated ahead of their launch, but are known to have failed commercially. Reasons for their failure include the products failing consumer expectations upon launch, the first round of units suffering defects, a controversy negatively affecting sales, or being the result of poor marketing, regardless of reception. In any case, these products failed to meet their companies' expectations needed to be considered successful, typically due to them failing on average to break even, resulting in the companies losing money. These high-profile items tend to appear on computer- and hardware-related "worst" lists or lists of failures (e.g., "tech fails").
Hardware
Components and peripherals
CueCat (2000–2001)
The CueCat is a cat-shaped barcode reader created by Dallas-based Digital Convergence Corporation amid the dot-com bubble and distributed from 2000 until the company's bankruptcy in 2001. Invented by Jovan Hutton Pulitzer (then named Jeffry Jovan Philyaw) intended to make accessing the websites of advertisers from newspapers, magazines, and catalogs easier, the device was plugged into a computer through its PS/2 port (later a USB port) and, along with regular barcodes, could read specialized barcodes on printed advertisements, which would then take the user to the target web page. The company heavily promoted the CueCat as it aimed to sell 50 million units by the end of 2001. The product's sponsors included The Coca-Cola Company, RadioShack, NBC, and Belo Corporation. It also mailed hundreds of thousands to subscribers of newspapers and magazines; Forbes distributed about 830,000 units and Wired about 500,000.
The CueCat's concept of replacing typing in a URL with scanning barcodes for convenience was met with criticism and derision. Walt Mossberg of The Wall Street Journal lampooned the need to have a computer nearby when scanning, calling it "unnatural and ridiculous". He also found that the majority of the special barcodes did not match the printed URLs, instead linking to general web pages, for which he asserted he could have typed them in faster. In addition, Digital Convergence received criticism for using the devices to send personally identifiable information of their users back to the company. The security concerns were amplified when, in late 2000, the CueCat website was subject to a breach that exposed the users' personal names and email addresses. Digital Convergence ended up giving out four million units in the United States—far short of its 50 million goal—with six million left unsold, and the company folded in 2001. The CueCat was ranked No. 20 on PC Worlds list of "The 25 Worst Tech Products of All Time". It also landed on Times list of "The 50 Worst Inventions", calling it "little more than a high-tech paperweight". Despite its poor showing, the CueCat has been viewed as a precursor to QR codes, which have become ubiquitous.
Itanium (2001–2020)
Itanium was a brand of 64-bit Intel microprocessors first announced in 1994 and released in 2001, after long delays. It was born in December 1988 as a secret Hewlett-Packard research project to succeed the company's PA-RISC instruction set architecture. Intel had its own processor in development, which would have extended its own x86 architecture to 64 bits while still retaining x86 compatibility, but dropped all work on the chip's design by June 8, 1994, when it announced a collaboration with Hewlett-Packard to develop a new 64-bit architecture called IA-64.
Intel announced the Itanium in 1997 with considerable fanfare, with International Data Group initially projecting sales to reach $38 billion by 2001. However, the first Itanium processor, codenamed Merced, suffered development delays, leading Silicon Graphics to cancel its first-generation Itanium system and Sun Microsystems to abandon the Itanium version of its Solaris operating system. Merced garnered a negative reception upon its May 2001 release for its sluggish performance and software incompatibility with x86-based processors. Meanwhile, in 2003, Advanced Micro Devices announced the first fully x86-compatible 64-bit processor, AMD64-based Opteron, and Intel faced a new challenger to its dominance in the office and home user markets. Intel was also forced to lower its ambitions for the struggling Itanium to being only a niche product for high-end systems, or what Pat Gelsinger called "the biggest iron". Further trouble was spelled in 2005, when Microsoft canceled Windows for Itanium-based workstations and IBM and Dell dropped dropped Itanium servers, with HP being the only top server manufacturer to sell them. When in 2019 Intel announced that it would accept orders up until January 30, 2020, and ship the last microprocessors by July 29, 2021, the only systems that were powered by a Itanium 9700-based chip, the last of the Itanium chips sold, were HPE Integrity Superdome computers. Far short of IDG's original projections, the Itanium line of processors generated sales worth only $1.4 billion, against an estimated billions invested into the project, and ultimately failed to replace the x86 architecture. The Itanium was soon recognized as a failure, for which the computer industry dubbed it "Itanic", after the ill-fated ocean liner.
Personal computers
TI-99/4 (1979–1981)
The TI-99/4 was the first mass-marketed home computer with a 16-bit microprocessor, which in this case was the TMS9900—the same processor used by TI-990 minicomputers. Manufactured by Texas Instruments, the TI-99/4 was born from two separate projects for a low-end video game console and a hobbyist-oriented personal computer, which were merged into one as a result of the two teams competing for the same company resources. The computer first retailed for $1,150 () in 1979 and, due to the Federal Communications Commission's strict RFI emissions regulations, shipped with a custom color TV monitor.
The TI-99/4, intended to serve both the video game and home computer markets, was received negatively. The chiclet keyboard was widely criticized, which, according to Joseph Nocera of Texas Monthly, "became the symbol for everything that was wrong" with the computer. A dearth of third-party software was also noted, due to both the hurdles of writing programs imposed by the TMS9900 processor and Texas Instruments' insistence that it make a profit from third-party software. The computer was referred to by The New York Times as "an embarrassing failure". The high cost of the TMS9900's nonstandard packaging precluded the company from earning a profit for each machine sold, and various reports estimate that only between 20,000 and 100,000 units were ever sold. Two editors for Creative Computing voted the TI-99/4 as one of the world's worst computers, ranked No. 6 on PC Magazines list of "The 12 Biggest PC Duds Ever", and PC World ranked the machine No. 6 on its list of "The 10 Worst PCs of All Time", both criticizing the chiclet keyboard and the latter magazine also citing the need to connect to the computer's own display as one of the reasons for its failure. The computer was supplanted in 1981 by an upgrade, the TI-99/4A, Texas Instruments' only other home computer before abandoning the market.
Apple III (1980–1984)
The Apple III, released in November 1980 as the successor to Apple II, was the first Apple computer not designed by Steve Wozniak, but rather by a committee of engineers led by Steve Jobs. The Apple III was sold as a business computer and housed a 1.8 MHz Synertek 6502A or 6502B processor and 128 KB of dynamic RAM. The Apple III was capable of resolutions of up to 560 × 192 pixels in black and white and up to 280 × 192 in up to 16 simultaneous colors, as well as displaying 80 columns and 24 rows of text, both capital and lowercase.
The Apple III failed commercially for multiple reasons. The computer, initially priced between $4,340 () and $7,800 depending on options, was deemed "absurdly" high even for professional users. In addition, the internal structure of the first batch of units, described as "a disaster" by The Daily Telegraph, used an aluminum enclosure inside the plastic case as the heat sink instead of a cooling fan, reputedly to meet Steve Jobs' demands for a silent computer and reduce RFI emissions, a severe problem affecting the Apple II. The result was that the Apple III would overheat, with the components lacking airflow, the motherboard being distorted by the heat and some chips slipping out of their sockets. 20 percent of the units failed to work as a result of the chips slipping during their shipment. Apple's public relations department later suggested that users lift the front of their units and drop them six inches off the desktop in hopes of re-seating the chips. A revised edition, launched in December 1981 for $3,495, addressed the overheating problem. Lastly, the Apple III shipped with an emulator mode that nominally ensured compatibility with Apple II software. However, many Apple II programs directly wrote on memory using PEEK and POKE commands, which did not align with the Apple III's memory structure. InfoCorp, a research firm, estimated that Apple sold only 75,000 units in December 1983, when the company was forced to redesign the Apple III to meet the Federal Communications Commission's requirements for low RFI emissions. The new computer, Apple III Plus, at a price of $2,995, brought the figure to an estimated 120,000 units sold, but the brand's reputation remained poor, and it was discontinued in April 1984. The original Apple III has been described as one of the worst computers of all time by PC World and Maximum PC, as well as one of the "20 spectacular failures" according to Byte and one of "the 10 greatest flops in computer history" according to The Daily Telegraph.
Apple Lisa (1983–1986)
Lisa is a home computer created and launched by Apple Computer on January 19, 1983, succeeding the company's best-selling computer, the Apple II. Lisa was the first commercialized personal computer with a graphical user interface, as opposed to a command-line interface. Lisa began development in 1978 and was to be a business computer with a built-in green phosphor display, keyboard, and command-line interface due to ship in March 1981 and retail for $2,000. However, it was discovered that designing a computer around a bit-slice microprocessor would be too expensive, so the idea was abandoned. Jef Raskin's visit to Xerox PARC, known among the American computer industry for the Xerox Alto, in the early 1970s also changed the course of Lisa's development. Raskin would have his student at University of California, San Diego, software engineer Bill Atkinson, convince Steve Jobs to visit PARC, and Jobs would recognize the value of GUIs in personal computers. Lisa's original project manager, Ken Rothmuller, who had complained that Trip Hawkins's market requirements document's specifications for a GUI, a mouse, a local area network, file servers, and innovative applications would take too long and be too costly to incorporate into the machine, was replaced with John Couch. The Lisa team demanded more than a computer with a Xerox Alto-inspired GUI, which it had reinvented to include novelties such as the menu bar, pull-down menus, the one-button mouse, cutting and pasting with the clipboard, and the Trash can. Ultimately, the computer's release date was pushed back to 1983, retailing for $9,995 () as it shipped with a Motorola 68000, 1 MB of RAM, two 5¼-inch floppy drives, a 5 MB hard disk drive, a built-in monochrome display, and seven applications.
Lisa struggled in the market for multiple reasons. The first was the price of the computer compared to its competitors, such as the popular IBM PC, which was introduced for $1,565. Secondly, its operating system, Lisa OS, supported preemptive multitasking, but it could not keep up with multiple programs running at the same time as it was paired with the Motorola 68000. The third reason was the unreliability of the hard drives, which were built in-house at Jobs' behest despite none at Apple having prior experience building one from scratch. The fourth reason was the lack of third-party software, which has been attributed to Lisa's bundled suite of applications that in turn discouraged developers from supporting it. Lastly, the press anticipation building up around what became Macintosh, further dimmed the machine's prospects. Apple took steps to reduce the cost of Lisa and lure back customers, eventually launching the Lisa 2 series with the base model now costing $3,495 and the high-end model, Lisa 2/10, having more memory and twice the capacity of the hard drive. However, Macintosh still outsold Lisa three to one. Apple rebranded Lisa 2/10 as Macintosh XL, also bundling it with a Macintosh emulator called MacWorks, and dropped the remaining Lisa models in January 1985 to consolidate the Macintosh line. Although the newly renamed computer's sales began to improve, it was officially discontinued on April 29, leaving an installed base of 60,000 units. Due to its price and the arrival of the much cheaper Macintosh, Lisa was named one of "20 spectacular failures" by Byte. It was also ranked No. 8 both on PC Magazines and Maximum PCs lists of "The 12 Biggest PC Duds Ever" and "The 16 Worst Failed Computers of All Time", respectively, and listed by The Daily Telegraph as one of "the 10 greatest flops in computer history".
Coleco Adam (1983–1985)
The Coleco Adam was Coleco's home computer released in October 1983, after the success of the company's video game console, ColecoVision, and against the backdrop of the ongoing video game crash. Initially retailed for less than $750 (), it was a complete low-cost system that shipped with a 75-key typewriter-style keyboard, a daisy-wheel printer, one drive for a class of proprietary data cassettes called Digital Data Packs with the option of a second, a Zilog Z80A as its main processor, and 80 KB of RAM expandable to 144 KB, with 16 KB dedicated to the video display. It was also fully backwards-compatible with all ColecoVision game cartridges and accessories via its cartridge and expansion slots and was packaged with a word processor, two ColecoVision joysticks, and three Digital Data Packs, one containing a version of BASIC called SmartBASIC, one preformatted to store programs and files, and a native copy of Buck Rogers: Planet of Zoom.
The Adam was sold in two versions: as a standalone unit and as Expansion Module No. #3 for the ColecoVision, which upgraded it to a home computer. Jules H. Gilder of Byte praised the high-speed tape system in general despite it not using floppy disks and wrote "three cheers" for the keyboard, but criticized the lack of a COPY command for creating backups, called the manual for SmartBASIC the worst he had ever seen, questioned Coleco's decision to limit the computer's technical information to licensed developers, and raised the Adam's aforementioned reliability record. He found the machine's potential to not be fully realized and, believing it could fail like the Mattel Aquarius before it, recommended holding off purchasing one until Coleco fixed all the problems and delivered its promises. Rushed into production ahead of Christmas 1983, the computer was plagued with numerous faults, with rates of returns of defective machines estimated to be as high as 60 percent. One dramatic fault was the system's ability to erase contents on a Digital Data Pack; this would result from a surge of electromagnetic energy emitted from the system's power supply on startup while the pack was left in the drive. The unusual daisy-chaining of the computer's components reduced the number of cables connected to the base, but also had the power supply located in the printer, and many Adams were rendered useless due to defective printers. The Adam was a marketing disaster for Coleco, which had spent $258 million repairing the computers, and price reductions down to $300 and even vouchers for a $500 college scholarship could not compensate for its continued poor sales. Only about 95,000 units were shipped by the end of 1983, a far cry from the original promise of 500,000, and Coleco discontinued the Adam in January 1985. The Adam was voted by three editors for Creative Computing as one of the world's worst computers, No. 3 on Maximum PCs list of "The 16 Worst Failed Computers of All Time", and as the third worst PC of all time by PC World.
Osborne Executive (1983)
The Osborne Executive is a self-named portable computer developed in 1983 by Osborne Computer Corporation, founded in 1981 by Adam Osborne, as the successor to its Osborne 1. The Osborne 1, credited as the world's first mass-marketed portable computer, was highly successful, but it had drawn criticism for its small screen size, meager memory, and a shortage of high-quality software. The Executive was released to address these issues, with a larger screen and more memory. However, it also cost more than the Osborne 1, at $2,495 (). As with the Osborne 1, the Executive was opened to reveal the built-in monitor, two floppy drives, and a detachable keyboard.
Before its announcement of the Executive, Osborne Computer Corporation was known to sell lightweight computers and for far less than its competitors, yet earn twice as much profit as the industry average. It was also one of the fastest growing companies in United States history, boasting yearly sales approaching $100 million. Nonetheless, it soon faced stiff competition from rivals such as IBM and Japanese computer manufacturers, who were producing more affordable machines with improved features. Seeking to stay ahead of the competition and vastly expand his company's operations to a $1 billion business in two years, Adam Osborne chose to invest in the development of three new products: the Executive 1, the more powerful IBM PC-compatible Executive 2, and the Vixen, which was to be sold at a lower price than the Osborne 1, and it became immediately apparent that their announcements was the company's liability. The announcement of the Executive's imminent release evaporated the 25-month backlog of orders for the Osborne 1, depriving the company of its major source of income, aggravated by a combination of repeated delays of the product, increasing consumer expectations for a computer, and IBM's unexpectedly aggressive endeavor in the portable market. The Executive was perceived as expensive compared to the competition and outdated due to its continued used of the CP/M when other manufacturers had adopted the IBM PC as the standard. In September 1983, Osborne Computer filed for bankruptcy, with only the first Executive model brought to fruition (although the Vixen was later revived and released). The Osborne effect refers to an upcoming product cannibalizing the sales of an existing product as a result of the company prematurely announcing the successor.
Commodore SX-64 (1984–1986)
The Commodore SX-64 is a portable computer based on Commodore International's most popular model, the Commodore 64, that debuted at the Winter Consumer Electronics Show of 1984, although it was first introduced at the same show a year earlier as a prototype. With a color screen, it is the first commercial portable computer with a color display. The SX-64 weighed , measured , and was almost fully compatible with software for the original Commodore 64, although it lacked a cassette tape port. The machine shipped with a built-in 1541 drive that sat below a compartment for storing disks and with enough space for a theoretical second drive. It was possible to connect the unit to a larger monitor, but it lacked an RF output, and it needed to be connected to an AC power outlet.
Sales of the SX-64 have been considered to be poor, disappointing Commodore as it had hoped that the portable would prove popular among business users, who instead viewed it as simply a portable version of the consumer-oriented Commodore 64. Along with a lack of focus on business software, the weight and small screen size were cited as factors contributing to the sluggish sales, as was the introductory price of $995 ()—nearly five times the price of a Commodore 64. The SX-64 was discontinued in 1986. Despite its lackluster sales, the computer has become a collector's item.
IBM PCjr (1984–1985)
In February 1982, after the launch of its highly successful IBM PC, IBM started three projects for the PC XT, PC AT, and PCjr. The PCjr would be the low-end home computer and become the first mass-marketed IBM product. Its original project manager, Bill Sydnes, sought a machine that would compete with the Apple II at a lower price, and, although its capabilities would be more limited than an IBM PC, they could be improved with hardware upgrades. However, six months into development, problems began to arise when Don Estridge, corporate vice president and head of the PC division, decided he disliked the concept of a consumer-oriented computer. The two disagreed over the PCjr's design and marketing. Particularly, Sydnes wanted it sold by general retail stores such as K Mart and J. C. Penney, but Estridge limited the vendors to conventional computer outlets, likely due to the tedium of stores applying for authorization. In addition, whereas Sydnes aimed for complete compatibility with the IBM PC, Estridge claimed that it would greatly cannibalize the PC's sales, although he agreed that the two computers ought to be compatible with spreadsheets and word processors. Sydnes resigned in the spring of 1983 and was replaced by Dave O'Connor. The design and production problems he inherited from his predecessor as a result of internal strife, along with what Dan Wilkie saw as a free hand for a team who lacked the competence to build the PCjr successfully, caused the team to miss engineering delays, ultimately pushing actual shipping to March 1984.
The PCjr was available in two models: a base model for $669 () and the higher-end Expanded Model for $1,269 (). The base model contains 64 KB of RAM and produces 40 columns for video output, while the Expanded Model, to which the base model can be upgraded, holds a total of 128 KB of RAM, supports 80-column video displays, and has a built-in floppy drive that loads 5¼-inch double-sided double-density disks with 360 KB of storage. Both models equipped with an Intel 8088 microprocessor, a keyboard that is connected with a detachable cord or wirelessly via the infrared link or, and PC DOS 2.1 as the operating system, but a display device had to be bought separately. Notably, the computer could display up to 16 colors and play up to three musical voices simultaneously—two clear advantages over the IBM PC—along with two slots for ROM cartridges, two joystick ports, and an unusual "user-friendly" design feature allowing for expansion modules called "sidecars" that could be daisy-chained, contributing significantly to the unit's width.
The PCjr's November 1983 debut drew a positive press reception. Several publishers briefly ran magazines dedicated to the PCjr, including Compute! for the PC and PCjr, the spinoff PCjr Magazine, and a supplement called PCjr World. Developers of add-ons for the original IBM PC viewed the PCjr as a lucrative investment, believing, according to PCjr Magazine, that the computer would be "a runaway success". The computer's reception upon launch was mixed, with computer magazines such as Byte praising the graphical and sound capabilities, the software base, and the documentation and customer service. However, its limited expandiblility, including beyond 128 of memory, and high price for a home computer received criticism. One widely maligned feature was the chiclet keyboard of the first models, which Byte called "a real loser" and which continued to draw the machine scorn that would persist even after IBM had shipped an advanced version of the PCjr at the end of July 1984 replacing it with a typewriter-style keyboard. The computer struggled to capture the home computer market, as customers expected a machine that would handle all the major software running on their office PCs flawlessly. IBM's July revision of the PCjr also allowed for expansion to 512 KB of memory, and the Enhanced Model now cost $999. However, the improvements and the price reduction did little to help the PCjr commercially. Finally, for Christmas 1984, in its last-ditch effort to save the PCjr, IBM pursued an aggressive, unprecedented marketing campaign and allowed vendors to sell a unit with a color monitor for $799. The holiday promotion significantly bolstered the PCjr's sales, with sources attributing 80 percent of a quarter of a million units sold in 1984. Nevertheless, at that price, the company failed to generate sufficient profit, and some industry experts believed that IBM was selling each unit at a loss. IBM ended the PCjr's production on March 19, 1985.
In adding the PCjr to its list of "20 spectacular failures", Byte deemed the computer a "cruelly crippled cousin of the IBM PC" that was overshadowed by Apple's Macintosh and "died a laughingstock" a year later. The PCjr topped PC Magazines list of "The 12 Biggest PC Duds Ever", was named the 13th worst tech product of all time by PC World, and the 16th worst failed computer by Maximum PC, and as one of "the 10 greatest flops in computer history" by The Daily Telegraph.
Macintosh Portable (1989–1991)
The Macintosh Portable is the first battery-powered Macintosh and Apple Computer's first portable computer, released in 1989 and featuring 1 MB of static random-access memory, a 16 MHz Motorola 68HC000, a black-and-white active matrix LCD display, a floppy disk drive, an SCSI mode allowing the unit to be used as a hard drive, and a removable trackball device. It weighed and measured up to thick, with lead-acid batteries contributing to the bulk of the weight. Reviews of the Portable were mixed, which tended to praise the LCD display, considered state-of-the-art technology at the time, but criticize the weight, size, and its high price, which ranged from $5,700 () to over $7,000 depending on which features were included. In comparison, a DOS-running portable could weigh lest than and cost under $3,000, and portables from Poqet and Atari—coincidentally released almost concurrently with the Macintosh Portable—would weigh under and fit inside a coat pocket. One analyst, David Cearly of Gartner Group, said, "One can only wonder how many people are willing to pay $8,000 for what essentially is a second computer." The editor of a personal computer newsletter in New York, Richard Shaffer, wrote, "This machine would have been OK 12 months or 18 months ago. But not today."
According to Tom Thompson of Byte, for the two years it was on the market, the Portable was the butt of jokes due to its size and weight compared to DOS portables. Sales of the Portable proved disappointing, with only 10,000 units sold in the first quarter of its availability, short of Apple's projection of 50,000 units in the first year, and the computer was superseded by three models of the PowerBook. The Portable has been ranked No. 17 of PC Worlds list of "The 25 Worst Tech Products of All Time" and No. 14 on Maximum PCs list of "The 16 Worst Failed Computers of All Time". Complex placed it No. 29 on its list of "The 50 Worst Fails In Tech History", and the Spanish magazine Computer Hoy also listed the Portable as the 4th worst computer, with both publications citing the weight, cost, and poor battery life and the latter calling it ugly.
3Com Audrey (2000–2001)
3Com was an American company known for developing modems and network interface controllers. 3Com conceived of a simple, low-cost Internet appliance that would keep a household wirelessly connected and virtually informed on Internet content, emails, and schedules from anywhere in the house, especially the kitchen. The result was the October 17, 2000, launch of the 3Com Audrey, a trapezoidal QNX-based tablet that had an touchscreen controlled with a stylus and was available in five kitchen colors. As well as with a bundled wireless keyboard, the user could write or draw with the stylus and send the handwritten messages by email. The Audrey also featured a built-in microphone used to record voicemail and a knob stylized like a television dial used to select websites formatted for the Audrey. Notably, as Palm, Inc. was a spinoff of 3Com, the tablet's HotSync technology allowed multiple Palm devices to synchronize with the unit's PIM.
PC Magazine became less skeptical of Internet appliances after testing the Audrey, ultimately recommending it. In contrast, David Pogue of The New York Times, while writing that the device "st[ood] head and shoulders" among the competition, criticized the small keyboard and the device's feminine design, which he viewed as patronizing. Like other Internet appliances, the Audrey failed to take off due to low consumer demand for a computer that cost as much as a full-fledged one, and was thus discontinued on June 1, 2001, although it gained popularity among hackers who reprogrammed the device for other purposes such as controlling household appliances. For its limited functionality and lack of broadband support, PC World added the Audrey as one of its "(Dis)Honorable Mentions" on its list of the worst tech products, deeming it "a symbol" of why Internet appliances failed. PC Magazine included the Audrey on its list of "The Biggest Hardware Flops of All Time", citing the price and the unfortunate timing of its release amid the dot-com crash.
Power Mac G4 Cube (2000–2001)
The Power Mac G4 Cube is a Mac developed by Apple Inc. between July 2000 and 2001. Conceived as a miniaturized but powerful computer by then-Apple CEO Steve Jobs, it was marketed as being between the consumer iMac G3 and the professional Power Mac G4 in the product range. The computer, designed by Jony Ive, was encased and suspended in acrylic glass measuring , with the transparent plastic intended to lend the impression of a floating machine.
While the Cube received positive reviews and awards for its design, reviewers noted that it was expensive compared to its power and lacked expandability. It was further criticized for its tendency to develop cracks in its case, significantly impacting sales of a computer favored by potential buyers for its aesthetics. The product was an immediate commercial failure, selling only about 150,000 units before it was discontinued just less than a year after its release. Macworlds Benj Edwards wrote that consumers regarded the Cube as "an underpowered, over-expensive toy or [...] an emotionally inaccessible, ultra-geometric gray box suspended in an untouchable glass prison". Maximum PC ranked the Cube No. 2 on its list of "The 16 Worst Failed Computers of All Time", citing its costs and cosmetic defects. Despite its commercial failure, the Cube influenced future Apple products; capacitive touch would reappear in Apple's iPod and iPhone lines, and the company's miniaturization efforts would benefit computers such as the iMac G4 and the Mac Mini, whose design was inspired by the Cube.
Mobile
JooJoo (2010)
The JooJoo was conceived by TechCrunch founder Michael Arrington, who in a 2008 blog post envisioned "dead simple Web tablet" that would cost about $200. Originally named the CrunchPad, the tablet was produced by Singapore-based Fusion Garage, headed by CEO Chandra Rathakrishnan. However, despite the prototypes' positive feedback from the media, the Arrington–Rathakrishnan partnership would hamper the device's development, with Arrington canceling plans for the tablet and Fusion Garage renaming it the JooJoo and raising the retail price to $499. While more expensive than a typical netbook, Rathakrishnan claimed that the original pricing was unrealistic. Eventually, the feud culminated in a lawsuit against Fusion Garage, further delaying the tablet's launch until March 29, 2010, as the official release date, although the legal battle hindered actual shipping for a few days. Meanwhile, Apple's widely anticipated iPad, formerly considered a competitor of the JooJoo, was launched on April 3 the same year for the same price, undercutting Fusion Garage's innovative edge over Apple.
The JooJoo was panned by reviewers upon release. PC Magazine called it a "woefully overpriced" "device that's essentially a Web browser trapped under a huge touch screen", and Engadget criticized the performance and short battery life as a result of the combination of the device's Intel Atom processor and Nvidia Ion chipset. Although its Adobe Flash support was seen as an advantage over the iPad, both publications criticized the device's poor responsiveness to user input and the generally frustrating user experience. A court document from the lawsuit revealed that only 90 preorders for the tablet were made, of which 15 were canceled. As of late April, the JooJoo reportedly sold only 64 units, and on November 19, it was discontinued. Due to its abysmal performance critically and in the marketplace, the JooJoo was named by PC Magazine as one of "The Biggest Hardware Flops of All Time".
Microsoft Kin (2010–2011)
Kin was a short-lived line of mobile phones created by Microsoft executive J Allard. Microsoft acquired Danger, Inc., known for the T-Mobile Sidekick, and its cloud computing intellectual property for $500 million in 2008 to kick-start its project. Kin's development was stunted by corporate politics between Allard and senior vice president Andy Lees, who was spearheading the development of what became Windows Phone 7. The two teams were separate, and Allard sought an original phone that would not share the same basis as Lees' project. However, Lees was reportedly jealous of Kin and probably concerned that it was distracting the Windows Phone team and diverting its resources. After enough pressure, Lees took the reins of Kin's development, and Allard's influence over the project dwindled considerably.
Under the auspices of its new leadership, Kin was redesigned from the ground up in keeping with Windows Phone. As a result, the phone was delayed a total of 18 months before being finally released on May 6, 2010, exclusively through Verizon Wireless. Marketed as a "chic" device toward teenagers and young adults, it was available in two models, Kin ONE for $50 and Kin TWO for $100, with 4 GB and 8 GB of storage, respectively, and data automatically backed up in the cloud—innovative for a phone at the time. While a desktop application called Kin Studio garnered unanimous praise, the devices themselves were criticized for the quality and quantity of built-in software and the mandatory $30 monthly data plan from Verizon, which PC World described as "appalling" and "hard to swallow". The devices were also seen as not true smartphones, given the inability to download third-party applications and games. Kin failed to take off commercially, with estimates of sales below 10,000 units, and Microsoft halted both models' production on June 30. Along with the negative reception, Microsoft's confusing attempts to distinguish the KIN OS from the platform of then-upcoming Windows Phone 7 and the company's mistake of not touting the device's automatic backup feature were cited as some of the factors for the poor sales. Later that year, Verizon relaunched the phones, now rebranded ONEm and TWOm, as feature phones, with a modified operating system and improved software, but they did nothing to recover the brand's sales, and in August 2011, the models were discontinued.
HP TouchPad (2011)
The HP TouchPad is a tablet computer designed by Hewlett-Packard. The TouchPad's development began after HP acquired Palm, Inc., known for its personal digital assistants, for about $1.2 billion in July 2010. The tablet was announced in February 2011, with HP insisting a March release, but Palm pushed back, citing that the TouchPad barely functioned, and it was ultimately launched on July 1 that year. The TouchPad was soon recognized as a commercial failure, with tablets reportedly piling up at Best Buy stores and the electronics chain sending some back and refusing new deliveries. Its introductory prices of $499 and $599 for models with 16- and 32 GB of storage, respectively, compared to those of the iPad 2 and the bugs found in the tablet's webOS 3.0 operating system were cited as reasons for the failure. HP attempted to lure customers with a rebate program, a weekend-only discount, and finally a permanent $100 price decrease in a single week in August, all of which proved fruitless. The company discontinued the TouchPad on August 18—just 48 days after it was launched, with Best Buy reporting only 25,000 of the 270,000 units in its stock. Hours later, a fire sale was held for the 16- and 32 GB models for $99 and $149, respectively. This resulted in the TouchPad quickly selling out, with 350,000 units reportedly sold in the first 24 hours. According to an NPD Group report published in November, the TouchPad became the best-selling non-iPad tablet in the United States in the first ten months of 2011, accounting for 17 percent of the 1.2 million tablets sold there. Nevertheless, for the fiscal year of 2011, HP wrote off $885 million in assets and another $755 million in costs of pulling out of the webOS market.
Google Glass (2012-2019)
Fire Phone (2014–2015)
The Fire Phone was Amazon's first smartphone. , it remains Amazon's only smartphone. The company touted the Fire Phone's Dynamic Perspective and Firefly features. Dynamic Perspective uses the phone's four cameras to detect where the user is looking to apply a 3D effect to perspectives and gestures, and Firefly is a virtual assistant that can identify around 100 million products, including those sold by Amazon, using the phone's sensors. Launched on July 25, 2014, the Fire Phone was available with 32 GB of storage for $649.99 () or 64 GB for $749.99, the prices of which were reduced by $450 if purchased with a two-year AT&T contract.
The Fire Phone received a lukewarm response from reviewers, who praised the free one-year subscription to Amazon Prime and the company's Mayday feature, which offers technical support, but criticized the phone's battery life, low amount of available software, and poor hardware design, which Farhad Manjoo, writing for The New York Times, described as "gimmicky". The phone was also seen as lacking incentive for iPhone and Samsung Galaxy users to buy one. The phone failed commercially, with Amazon writing down $170 million on unsold units and The Guardian estimating that only around 35,000 units were sold a month after it was launched, and the phone's price with the AT&T contract was reduced to just 99 cents by September. Amazon discontinued the Fire Phone on September 8, 2015.
Samsung Galaxy Note 7 (2016)
The Samsung Galaxy Note 7 was the sixth main device in Samsung's Galaxy Note line of Android phablets. A high-end smartphone, it featured a screen and a stylus. The Note 7 was unveiled to critical acclaim before its August 19, 2016, launch, with reviewers lauding the design and ergonomics and a screen that was larger and sharper than that of Apple's iPhone 6s. The device's retina scanner, waterproofing, and rear-facing dual cameras were also praised, as was the lithium-ion battery's capacity, which, at 3,500 mAh, allowed up to 36 hours of constant use without recharging.
However, the praise and enthusiasm soon dissipated in the wake of numerous reports of the phones catching fire, in some cases exploding. Samsung halted production on September 2 as the company scrambled to send replacements and the news of the incidents wiped $26 billion off of the company's stock value. The problem, as an internal investigation concluded in January 2017 determined, was a defect in the batteries of the first batch of phones, which had been manufactured by Samsung SDI. The upper right corner of the battery's casing left too little room for the negative electrodes, leading to the electrodes being bent in each of the 200,000 recalled devices tested and stressing the insulating separator placed between the positive and negative electrode foils. The negative electrodes were also found to be too long, and the batteries of some units had too thin separators. If the separator failed, the battery would short-circuit, causing catastrophic thermal runaway. By September 21, retail stores began exchanging replacement devices containing batteries now supplied by Amperex Technology, and sales of the Note 7 resumed, but reports of the devices also catching fire began to surface. The January investigation found that the replacements' batteries, due to poor welding, had burrs on the positive electrode that would scrape the insulation tape and the separator, and some units were missing insulation tape, both rendering the devices prone to the same catastrophic failure. On October 11, 53 days after the Note 7 was launched, Samsung recalled 2.5 million units—the largest in smartphone history—and permanently discontinued production.
The fiasco was estimated to cost Samsung $17 billion. Airlines across the United States, Asia, Europe, Australia, and New Zealand moved to ban the devices from flights. Due to a reputation for combusting that has overshadowed its popularity, PC Magazine names the Note 7 as one of "The Biggest Hardware Flops of All Time".
Software
Lotus Jazz (1985–1988)
Apple Computer's Macintosh debuted in January 1984 after a well-received introduction, but struggled to see widespread adoption by businesses. Apple sought a "killer application" that could boost the Macintosh's stagnant sales. When Lotus Development Corporation, known for its Lotus 1-2-3 spreadsheet application, itself considered the killer application for the IBM PC, announced Lotus Jazz in November, Apple CEO John Sculley, who was present at the product's introduction, hailed it as "strategically significant for Apple", calling it "a very important day for, obviously, Lotus—but also for Apple and the industry". Jazz is a productivity suite similar to Lotus Symphony for MS-DOS that was bundled with a word processor, a spreadsheet program, a database manager, a graphics editor, and telecommunications software. The software package was planned for a March 1985 release, but ended up shipping in August, selling for $595 ().
Unlike Lotus 1–2–3, Jazz's performance in the market was lackluster, capturing only 9 percent of the Macintosh software market compared to the top-selling software in February 1986, Microsoft Excel, with 36 percent of the share. By April, the company had sold only 42,000 copies. The sales were partly attributed to the high pricing and the failure of Lotus Development to use the 1-2-3 brand. The suite's reception was also poor. PC Magazine summed up the product as "a klutzy multifunction program that fell well short of Lotus's reputation for fast, innovative highly functional software". The software's use of copy protection was also criticized. Lotus Development co-founder Mitch Kapor admitted that Jazz was an "overly ambitious" project plagued with bugs that took the team longer to develop than expected. An update, called Lotus Modern Jazz, was planned for a 1988 release, but Lotus Development canceled it later that year. PC Magazine listed the original Jazz as one of "The 20 Biggest Software Flops of All Time".
Microsoft Bob (1995–1996)
Microsoft Bob was a Microsoft software package that provided a graphical interface for users of Windows 3.x. Designed to make using Windows simpler, the software replaced the Program Manager and its pull-down menus and icons with a house in which one of 11 cartoon characters, the default being Rover the dog, guided the user with instructions inside speech balloons. The rooms consisted of objects that could be clicked on to run one of eight programs. For example, clicking on a piece of paper would allow the user to type a letter.
Microsoft touted Bob as the first kind of a social interface, and many analysts predicted that the interface's style could supplant the desktop-and-folders one invented by the Macintosh. Despite early praise for its presentation, Bob received generally negative reviews, with reviewers criticizing the room style of the interface, the guides, the lack of customizability and manual, high system requirements, and practicality. Stephen Manes, writing for The New York Times, ended his review by referring to the product as a "toy". The apparent lack of an embargo on reviews between January and Bob's March 31 release negatively affected product sales; by early 1996, when Bob was discontinued, only about 58,000 copies were ever sold, compared to about 2.75 million licenses of Windows 95 sold in its first month, according to PC Data.
Microsoft Bob is remembered as the application that the Comic Sans font was designed for (but was ultimately left out of) and for the debut of the characters Clippy, an anthropomorphic paperclip, and Rover. Comic Sans would later be bundled with Windows, and Clippy and Rover would reappear as assistants for Microsoft Office versions 97 to 2003 and Windows XP's search feature, respectively. Time named Bob and Clippy as two of "The 50 Worst Inventions", calling the former an "expensive and overly cutesy" piece of software that was "designed around Clippy". PC World ranked the product No. 7 on its list of "The 25 Worst Tech Products of All Time" and Complex No. 27 on its list of "The 50 Worst Fails In Tech History".
Windows Phone (2010–2017)
Windows Phone is a discontinued mobile operating system that debuted in October 2010 as a major update for and succeeding Microsoft's earlier Windows Mobile, which itself has roots in the Windows CE-based Pocket PC. Appearing first as Windows Phone 7 after as much as about six years in the making, Windows Phone entered the market with stiff competition from Apple's iPhone and Google's Android. The operating system stood out from its rivals in its use of a simplified design language called Metro and also in grouping related applications into "hubs" intended to display and allow for important information and tasks without the need to switch between applications constantly. Reception of Windows Phone 7 was mixed, with reviewers praising the operating system's interface design, but criticizing the lack of basic features found in the iPhone and Android, such as copy-and-paste, custom ringtones, and tethering. Third-party applications were also limited by the available APIs and the multitasking extremely so, and the pace at which Microsoft added the missing features in updates further exacerbated user frustrations. However, Windows Phone's prospects were drastically improved a year later when Nokia, then the world's largest smartphone manufacturer, released the first of its Nokia Lumia phones, the 710 and the higher-end 800, both with the Windows Phone 7.5 update installed; the update and the devices were received more favorably compared to the original Windows Phone at launch, though there were concerns regarding the price of the phones. Even so, Windows Phone consistently trailed Android and iPhone in shares of the smartphone market, peaking in its lifetime at just 3.6 percent in the third quarter of 2013, according to Gartner.
In late 2012, Microsoft released an upgrade called Windows Phone 8, now based on the Windows NT kernel (the same as Windows 8 and Windows RT) supporting multi-core CPUs, near-field communication, microSD cards, and high-definition screens and making important software improvements such as a more customizable Start screen and the ability to capture screenshots. Notable devices using the new operating system include the Nokia Lumia 520, which remains the best-selling Windows Phone device, and the Nokia Lumia 1020, known for its 41-megapixel camera. As with its predecessor, Windows Phone 8 received mixed reviews upon release, with users again criticizing the lack of basic features such as a screen rotation lock and custom notification sounds and the pace at which said features would be added in updates—a common critique that the Windows Phone family had come to endure— as well as the dearth of third-party applications on launch and the incomplete feel of the operating system. A major update, Windows Phone 8.1, was released in April 2014, introducing a plethora of new features and improvements, among them a Swype-style keyboard, which briefly held a Guinness World Record for the fastest onscreen keyboard, and a widely anticipated virtual assistant called Cortana. Meanwhile, Nokia continued to expand its share of the Windows Phone market such that, by September 2013, the Lumia phones had overwhelmingly dominated Windows Phone sales. Nevertheless, the Finnish phone manufacturer was designing and selling the phones at a loss, and Nokia was planning the launch of low-cost phones running a forked version of Android, threatening Microsoft's mobile ambitions. Microsoft acquired Nokia's phone business later in April 2014 in a deal worth about $7.2 billion. However, in July, Microsoft announced the biggest layoffs in company history, affecting 18,000 people, of whom over two-thirds had just joined following the Nokia acquisition. The following year, Microsoft was also forced to write off $7.6 billion—more than the entire cost of the acquisition—and lay off a further 7,800.
The last major iteration of Windows Phone, Windows 10 Mobile, was released in early 2016, adding support for Universal Windows Platform apps, which are cross-compatible with Windows devices and Xbox One. It also featured Continuum, an application that provides a desktop-like interface for users who connect their devices to a keyboard and a mouse, and then to a display. Still, developers saw little incentive to support the mobile operating system, and the Windows Phone devices continued their downward trajectory. While Microsoft posted revenue of $1.397 billion for its hardware in the third quarter of fiscal year 2015, that figure plunged to $735 million the next year before collapsing to just $5 million the year after. On October 8, 2017, Microsoft vice president of operating systems Joe Belfiore tweeted that the company would end mainstream support for Windows Phone, due to its low user base. According to IDC, shares had dwindled to a mere 0.1 percent by March 2017. The last update, version 1709 for Windows 10 Mobile, arrived on December 10, 2019. Due to the operating system's eventual inability to eat into the iPhone's and Android's market dominance, The Verge considers Windows Phone overall to be a failure.
See also
List of commercial failures in video games
Osborne effect
References
Works cited
Failure
Lists of computer hardware
Lists of software | List of commercial failures in computing | [
"Technology"
] | 10,788 | [
"Computing-related lists",
"Lists of software",
"Lists of computer hardware"
] |
77,733,786 | https://en.wikipedia.org/wiki/Crew%20Dragon%20C213 | Crew Dragon C213 is the fifth and final Crew Dragon reusable spacecraft manufactured and operated by SpaceX. It is planned to make its maiden flight in March 2025 to the International Space Station (ISS) on the SpaceX Crew-10 mission.
History
Crew Dragon C213 is the fifth and final Crew Dragon spacecraft. It is planned to make its maiden flight in March 2025 to the International Space Station (ISS) on the SpaceX Crew-10 mission. As such, the astronauts assigned to the Crew-10 mission will have the honor of naming the capsule.
Flights
List includes only completed or currently manifested missions. Dates are listed in UTC, and for future events, they are the earliest possible opportunities (also known as dates) and may change.
References
SpaceX Dragon 2
Individual space vehicles
NASA spacecraft
Crewed spacecraft | Crew Dragon C213 | [
"Astronomy"
] | 167 | [
"Astronomy stubs",
"Spacecraft stubs"
] |
77,735,541 | https://en.wikipedia.org/wiki/Design%20principles | Design principles are propositions that, when applied to design elements, form a design.
Unity/harmony
According to Alex White, author of The Elements of Graphic Design, to achieve visual unity is a main goal of graphic design. When all elements are in agreement, a design is considered unified. No individual part is viewed as more important than the whole design. A good balance between unity and variety must be established to avoid a chaotic or a lifeless design.
Methods
Perspective: sense of distance between elements.
Similarity: ability to seem repeatable with other elements.
Continuation: the sense of having a line or pattern extend.
Repetition: elements being copied or mimicked numerous times.
Rhythm: is achieved when recurring position, size, color, and use of a graphic element has a focal point interruption.
Altering the basic theme achieves unity and helps keep interest.
Balance
It is a state of equalized tension and equilibrium, which may not always be calm.
Types of balance in visual design
Symmetry
Asymmetrical balance produces an informal balance that is attention attracting and dynamic.
Radial balance is arranged around a central element. The elements placed in a radial balance seem to 'radiate' out from a central point in a circular fashion.
Overall is a mosaic form of balance which normally arises from too many elements being put on a page. Due to the lack of hierarchy and contrast, this form of balance can look noisy but sometimes quiet.
Hierarchy/Dominance/Emphasis
A good design contains elements that lead the reader through each element in order of its significance. The type and images should be expressed starting from most important to the least important. Dominance is created by contrasting size, positioning, color, style, or shape. The focal point should dominate the design with scale and contrast without sacrificing the unity of the whole.
Scale/proportion
Using the relative size of elements against each other can attract attention to a focal point. When elements are designed larger than life, the scale is being used to show drama. Scale can be considered both objectively and subjectively. In terms of objective, scale refers to the exact literal physical dimensions of an object in the real world or the coloration between the representation and the real one. Printed maps can be good examples as they have an exact scale representing the real physical world. Subjectively, however, scale refers to one's impression of an object's size. A representation “lacks scale” when there is no exact cause linking it to lived experience, giving it a physical identity. As an example, a book may have a grand or intimate scale based on how it relates to our own body or our knowledge of other books.
Scale in design
A printed piece can be as small as a postage stamp or as large as a billboard. A logo should be legible both in tiny dimensions as well as from a distance on a screen. Some projects have their specified scale designed for a certain medium or site, while some others need to work in various sizes designed for reproduction in multiple scales. No matter what size the design work is, it should have its own sense of scale. Increasing an element's scale in a design piece increases its value in terms of hierarchy and makes it to be seen first compared to other elements while decreasing an element's scale reduces its value.
Similarity and contrast
Planning a consistent and similar design is an important aspect of a designer's work to make their focal point visible. Too much similarity is boring but without similarity important elements will not exist and an image without contrast is uneventful so the key is to find the balance between similarity and contrast.
Similar environment
There are several ways to develop a similar environment:
Build a unique internal organization structure.
Manipulate shapes of images and text to correlate together.
Express continuity from page to page in publications. Items to watch include headers, themes, borders, and spaces.
Develop a style manual and adhere to it.
Contrasts
Space
Filled / Empty
Near / Far
2-D / 3-D
Position
Left / Right
Isolated / Grouped
Centered / Off-Center
Top / Bottom
Form
Simple / Complex
Beauty / Ugly
Whole / Broken
Direction
Stability / Movement
Structure
Organized / Chaotic
Mechanical / Hand-Drawn
Size
Large / Small
Deep / Shallow
Fat / Thin
Color
Grey scale / Color
Black & White / Color
Light / Dark
Texture
Fine / Coarse
Smooth / Rough
Sharp / Dull
Density
Transparent / Opaque
Thick / Thin
Liquid / Solid
Gravity
Light / Heavy
Stable / Unstable
Movement is the path the viewer's eye takes through the artwork, often to focal areas. Such movement can be directed along lines edges, shape and color within the artwork, and more.
See also
Composition (visual arts)
Gestalt laws of grouping
Interior design
Landscape design
Pattern language
Elements of art
Principles of art
Color theory
Notes
References
Kilmer, R., & Kilmer, W. O. (1992). Designing Interiors. Orland, FL: Holt, Rinehart and Winston, Inc. .
Nielson, K. J., & Taylor, D. A. (2002). Interiors: An Introduction. New York: McGraw-Hill Companies, Inc.
Pile, J.F. (1995; fourth edition, 2007). Interior Design. New York: Harry N. Abrams, Inc.
Sully, Anthony (2012). Interior Design: Theory and Process. London: Bloomsbury. .
External links
Art, Design, and Visual Thinking. An online, interactive textbook by Charlotte Jirousek at Cornell University.
The 6 Principles of Design
Design
Composition in visual art | Design principles | [
"Engineering"
] | 1,109 | [
"Design"
] |
77,735,553 | https://en.wikipedia.org/wiki/Design%20elements | Design elements are the basic units of any visual design which form its structure and convey visual messages. Painter and design theorist Maitland E. Graves (1902–1978), who attempted to gestate the fundamental principles of aesthetic order in visual design, in his book, The Art of Color and Design (1941), defined the elements of design as line, direction, shape, size, texture, value, and color, concluding that "these elements are the materials from which all designs are built."
Color
Color is the result of light reflecting back from an object to our eyes. The color that our eyes perceive is determined by the pigment of the object itself. Color theory and the color wheel are often referred to when studying color combinations in visual design. Color is often deemed to be an important element of design as it is a universal language which presents the countless possibilities of visual communication. Color serves various purposes to contribute to the overall effectiveness of the design. It is used as an element to convey meaning and emotion, create visual hierarchy, enhance brand identity, improve readability and accessibility, create visual interest and appeal, differentiate information and elements, and make cultural and contextual significance.
Hue, saturation, and brightness are the three characteristics that describe color.
Hue can simply be referred to as "color" as in red, yellow, or green.
Saturation gives a color brightness or dullness, which impacts the vibrance of the color.
Values, tints and shades of colors are created by adding black to a color for a shade and white for a tint. Creating a tint or shade of color reduces the saturation.
Color theory in visual design
Color theory studies color mixing and color combinations. It is one of the first things that marked a progressive design approach. In visual design, designers refer to color theory as a body of practical guidance to achieving certain visual impacts with specific color combinations. Theoretical color knowledge is implemented in designs in order to achieve a successful color design.
Color harmony
Color harmony, often referred to as a "measure of aesthetics", studies which color combinations are harmonious and pleasing to the eye, and which color combinations are not. Color harmony is a main concern for designers given that colors always exist in the presence of other colors in form or space.
When a designer harmonizes colors, the relationships among a set of colors are enhanced to increase the way they complement one another. Colors are harmonized to achieve a balanced, unified, and aesthetically pleasing effect for the viewer.
Color harmony is achieved in a variety of ways, some of which consist of combining a set of colors that share the same hue, or a set of colors that share the same values for two of the three color characteristics (hue, saturation, brightness). Color harmony can also be achieved by simply combining colors that are considered compatible to one another as represented in the color wheel.
Color contrasts
Color contrasts are studied with a pair of colors, as opposed to color harmony, which studies a set of colors. In color contrasting, two colors with perceivable differences in aspects such as luminance, or saturation, are placed side by side to create contrast.
Johannes Itten presented seven kinds of color contrasts: contrast of light and dark, contrast of hue, contrast of temperature, contrast of saturation, simultaneous contrast, contrast of sizes, and contrast of complementary. These seven kinds of color contrasts have inspired past works involving color schemes in design.
Color schemes
Color schemes are defined as the set of colors chosen for a design. They are often made up of two or more colors that look appealing beside one another, and that create an aesthetic feeling when used together. Color schemes depend on color harmony as they point to which colors look pleasing beside one another.
A satisfactory design product is often accompanied by a successful color scheme. Over time, color design tools with the function of generating color schemes were developed to facilitate color harmonizing for designers.
Use of color in visual design
Color is used to create harmony, balance, and visual comfort in a design
Color is used to evoke the desired mood and emotion in the viewer
Color is used to create a theme in the design
Color holds meaning and can be symbolic. In certain cultures, different colors can have different meanings.
Color is used to put emphasis on desired elements and create visual hierarchy in a piece of art
Color can create identity for a certain brand or design product
Color allows viewers to have different interpretations of visual designs. The same color can evoke different emotions, or have various meanings to different individuals and cultures
Color strategies are used for organization and consistency in a design product
In the architectural design of a retail environment, colors affect decision-making, making which motivates consumers to buy particular products
Color strengthens narrative and storytelling in visual design.
Color can represent characters, themes, and symbolism.
Color is a tool that designers use to strategically add layers of meaning and subtext to their designs.
Colors can create recurring visual motifs in a design, strengthening ideas and fostering coherence.
Color is an effective tool for communication because it allows for complex interpretation and expression.
Line
The line is an element of art defined by a point moving in space. . More specifically, Line is defined as a series of points, or the connection between two points, or the path of a moving point. The importance of line comes from its versatility as its characteristics is significantly expressive. Lines can be vertical, horizontal, diagonal, or curved, they may also appear as linear shapes that take on a line-link quality, or as suggested line perceived from eyes as they follow a sequence related shapes. Line may be used either in two-dimensional forms with enclosing a space as an outline and creating shape, or in three-dimensional forms. They can be any width or texture, and can be continuous, implied, or broken. On top of that, there are different types of lines aside from the ones previously mentioned. For example, you could have a line that is horizontal and zigzagged or a line that is vertical and zigzagged. Different lines create different moods, it all depends on what mood you are using line to create and convey.
Point
A point is basically the beginning of “something” in “nothing”. It forces the mind to think upon its position and gives something to build upon in both imagination and space. Some abstract points in a group can provoke human imagination to link it with familiar shapes or forms.
Shape
A shape is defined as a two dimensional area that stands out from the space next to or around it due to a defined or implied boundary, or because of differences of value, color, or texture. Shapes are recognizable objects and forms and are usually composed of other elements of design.
For example, a square that is drawn on a piece of paper is considered a shape. It is created with a series of lines which serve as a boundary that shapes the square and separates it from the space around it that is not part of the square.
Types of shapes
Geometric shapes or mechanical shapes are shapes that can be drawn using a ruler or compass, such as squares, circles, triangles, ellipses, parallelograms, stars, and so on. Mechanical shapes, whether simple or complex, produce a feeling of control and order.
Organic shapes are irregular shapes that are often complex and resemble shapes that are found in nature. Organic shapes can be drawn by hand, which is why they are sometimes subjective and only exist in the imagination of the artist.
Curvilinear shapes are composed of curved lines and smooth edges. They give off a more natural feeling to the shape. In contrast, rectilinear shapes are composed of sharp edges and right angles, and give off a sense of order in the composition. They look more human-made, structured, and artificial. Artists can choose to create a composition that revolves mainly around one of these styles of shape, or they can choose to combine both.
Texture
Texture refers to the physical and visual qualities of a surface.
Definition of texture
Texture is the variation of data at a scale smaller than the scale of the main object. Taking a person wearing a Hawaiian shirt as an example, as long as we consider the person as the main object looking at, the patterns of their shirt are considered as texture. However, if we try to identify the pattern of the shirt, each flower or bird of the pattern is a non-textured object, as no smaller detail inside of it can be recognized. Texture in our environment helps us to better understand the nature of things, as a smooth paved road signals safe passage and thick fog creates a veil on our view.
Texture in design
Texture in design includes the literal physical surface employed in a printed piece as well as the optical appearance of the surface. Physical texture affects how the piece feels in hand and also how it conveys the design, as a glossy surface for example reflects the light differently than a soft or pebbly one. Many of the textures manipulated by graphic designers, however, cannot be physically experienced as it is utilized in the visual representation aspect of the design. Texture adds detail to an image in a way that conveys the overall quality of a surface. Graphic designers use texture to establish a mood, reinforce a point of view, or convey a sense of physical presence whether setting a type or drawing a tree.
Uses of texture in design
Texture can be used to attract or repel interest to an element, depending on how pleasant the texture is perceived to be.
Texture can also be used to add complex detail into the composition of a design.
In theatrical design, the surface qualities of a costume sculpt the look and feel of a character, which influences the way the audience reacts to the character.
Types of texture
Tactile texture, also known as "actual texture", refers to the physical three-dimensional texture of an object. Tactile texture can be perceived by the sense of touch. A person can feel the tactile texture of a sculpture by running their hand over its surface and feelings its ridges and dents.
Painters use impasto to build peaks and create texture in their painting.
Texture can be created through collage. This is when artists assemble three dimensional objects and apply them onto a two-dimensional surface, like a piece of paper or canvas, to create one final composition.
Papier collé is another collaging technique in which artists glue paper to a surface to create different textures on its surface.
Assemblage is a technique that consists of assembling various three-dimensional objects into a sculpture, which can also reveal textures to the viewer.
Visual texture, also referred to as "implied texture", is not detectable by our sense of touch, but by our sense of sight. Visual texture is the illusion of a real texture on a two-dimensional surface. Any texture perceived in an image or photograph is a visual texture. A photograph of rough tree bark is considered a visual texture. It creates the impression of a real texture on a two-dimensional surface which would remain smooth to the touch no matter how rough the represented texture is.
In painting, different paints are used to achieve different types of textures. Paints such as oil, acrylic, and encaustic are thicker and more opaque and are used to create three-dimensional impressions on the surface. Other paints, such as watercolor, tend to be used for visual textures, because they are thinner and have transparency, and do not leave much tactile texture on the surface.
Pattern
Many textures appear to repeat the same motif. When a motif is repeated over and over again in a surface, it results in a pattern. Patterns are frequently used in fashion design or textile design, where motifs are repeated to create decorative patterns on fabric or other textile materials. Patterns are also used in architectural design, where decorative structural elements such as windows, columns, or pediments, are incorporated into building design.
Space
In design, space is concerned with the area deep within the moment of designated design, the design will take place on. For a two-dimensional design, space concerns creating the illusion of a third dimension on a flat surface:
Overlap is the effect where objects appear to be on top of each other. This illusion makes the top element look closer to the observer. There is no way to determine the depth of the space, only the order of closeness.
Shading adds gradation marks to make an object of a two-dimensional surface seem three-dimensional.
Highlight, Transitional Light, Core of the Shadow, Reflected Light, and Cast Shadow give an object a three-dimensional look.
Linear Perspective is the concept relating to how an object seems smaller the farther away it gets.
Atmospheric Perspective is based on how air acts as a filter to change the appearance of distant objects.
Form
In visual design, form is described as the way an artist arranges elements in the entirety of a composition. It may also be described as any three-dimensional object. Form can be measured, from top to bottom (height), side to side (width), and from back to front (depth). Form is also defined by light and dark. It can be defined by the presence of shadows on surfaces or faces of an object. There are two types of form, geometric (artificial) and natural (organic form). Form may be created by the combining of two or more shapes. It may be enhanced by tone, texture or color. It can be illustrated or constructed.
See also
Composition (visual arts)
Interior design
Landscape design
Pattern language
Elements of art
Color theory
Notes
References
Kilmer, R., & Kilmer, W. O. (1992). Designing Interiors. Orland, FL: Holt, Rinehart and Winston, Inc. .
Nielson, K. J., & Taylor, D. A. (2002). Interiors: An Introduction. New York: McGraw-Hill Companies, Inc.
Pile, J.F. (1995; fourth edition, 2007). Interior Design. New York: Harry N. Abrams, Inc.
Sully, Anthony (2012). Interior Design: Theory and Process. London: Bloomsbury. .
External links
Art, Design, and Visual Thinking. An online, interactive textbook by Charlotte Jirousek at Cornell University.
The 6 Principles of Design
Design | Design elements | [
"Engineering"
] | 2,893 | [
"Design"
] |
77,737,062 | https://en.wikipedia.org/wiki/Airalo | Airalo is a company that sells eSIMs. It is headquartered in Delaware with its operational base in Singapore. As of May 2024, it had 10 million users. It offers eSIMs for use in over 200 countries.
eSIMs are a type of SIM card, particularly useful for international travel.
History
Airalo was founded in 2019 by Ahmet Bahadir Ozdemir, a serial entrepreneur, Abraham Burak, a Canadian businessman, and Duran Akcaylier, a web application designer and developer. Duran Akcaylier left the company in 2020.
In May 2024, the company reached 10 million users.
Financing
In 2019, Airalo secured $1.9 million in seed funding from Antler and Sequoia Capital.
In October 2021, it secured $5 million in Series A financing.
In July 2023, it received $60 million in a Series B financing round led by e& Capital, the venture arm of e&, with participation from Antler Elevate, Liberty Global, Rakuten Capital, Singtel Innov8, Surge, Orange, T Capital (the venture arm of Deutsche Telekom), KPN Ventures, Telefónica Ventures, and I2BF Global Ventures. At that time, it had 5.1 million customers.
See also
Nomad (eSIM company)
References
External links
Companies established in 2019
Mobile virtual network operators
Telecommunications companies established in 2019
Telecommunications companies of the United States
ESIM companies | Airalo | [
"Technology"
] | 302 | [
"ESIM companies",
"Mobile technology companies"
] |
77,737,408 | https://en.wikipedia.org/wiki/Surface%20Hub%203 | The Surface Hub 3 is an interactive whiteboard designed, developed, and marketed by Microsoft. It is part of the third-generation of the Surface Hub, succeeding the Surface Hub 2 and 2S.
Timeline
References
External links
– official website
Microsoft Surface
Tablet computers introduced in 2015
2-in-1 PCs | Surface Hub 3 | [
"Technology"
] | 62 | [
"Crossover devices",
"2-in-1 PCs",
"Computing stubs",
"Computer hardware stubs"
] |
63,278,681 | https://en.wikipedia.org/wiki/Scrcpy | scrcpy (short for "screen copy") is a free and open-source screen mirroring application that allows control of an Android device from a desktop computer. The software is developed by Genymobile SAS, a company which develops Android emulator Genymotion.
The application primarily uses the Android Debug Bridge (ADB) via a USB connection to communicate. The software functions by executing a server natively on the Android device, then communicating with the server via a socket over an ADB tunnel. The screen content is streamed as H.264 video, which the software then decodes and displays on the computer. The software pushes keyboard and mouse input to the Android device over the server.
Setup involves enabling USB debugging on the Android device, connecting the device to the computer, and running the scrcpy application on the computer. Additional configuration options, such as changing the stream bit rate or enabling screen recording, may be accessed via command line arguments. The software also supports a wireless connection over Wi-Fi, but that requires more steps to set up. A few features were added to scrcpy in its version 1.9 release in 2019, including the ability to turn the screen off while mirroring and to copy clipboard content between the two devices.
Chris Hoffman of How-To Geek compared scrcpy to AirMirror and Vysor, two other applications with a similar function. Hoffman also pointed to Miracast as an alternative, while noting that it is no longer widely supported among new Android devices, and that it does not support remotely controlling the device.
History
The first commit to the GitHub repository is on 12 December 2017 by Romain Vimont. scrcpy v1.0 was released 3 months later which included the support for basic screen mirroring and Android remote control. The first release packaged a Windows Executable and the server. The community took packaging forward and made scrcpy available for numerous Linux distributions.
Version v2.0, released on 12 March 2023, also added audio support, enabling real-time audio forwarding on Android 11 and above.
On v2.1, unveiled on June 22, 2023, significant enhancements have been made to the audio capabilities. Users can now select their device's microphone as the audio input, adjust the audio output buffer size, and benefit from a range of other updates. These updates include support for OpenGL 3.0+ on macOS, dynamic device folding, and the option to terminate adb upon closing.
Features
The official documentation of scrcpy gives the features and ideology to which it was built
lightness (native, displays only the device screen)
performance (30~60fps)
quality (1920×1080 or above)
low latency (35~70ms)
low startup time (~1 second to display the first image)
non-intrusiveness (nothing is left installed on the device)
user benefits no account, no ads, no internet required
freedom free and open source software
Graphical user interface
The command line interface of scrcpy was ported to a graphical user interface by open source developers.
Further reading
References
External links
GitHub repository
Cross-platform free software
Android (operating system) development software
Remote administration software
Command-line software | Scrcpy | [
"Technology"
] | 667 | [
"Command-line software",
"Computing commands"
] |
63,279,733 | https://en.wikipedia.org/wiki/Mirka%20Miller | Mirka Miller (née Koutova, 9 May 1949 – 2 January 2016) was a Czech-Australian mathematician and computer scientist interested in graph theory and data security. She was a professor of electrical engineering and computer science at the University of Newcastle.
Life
Miller was born on 9 May 1949 in Rumburk, then part of Czechoslovakia, as the oldest in a family of five children. After attempting to escape Czechoslovakia in 1968, stopped because of her companion's illness, she became a student at Charles University before successfully escaping in 1969 and becoming a refugee in Australia.
Miller earned a bachelor's degree from the University of Sydney in 1976, both in mathematics and computer science,
and as a student also played volleyball for the New South Wales team and then the Australia women's national volleyball team.
She married ornithologist Ben Miller, became a computer programmer working with the Sydney Morning Herald and for NSW Parks and Wildlife on Lord Howe Island, and began raising a son with Miller.
She separated from her husband and returned to graduate study, earning two master's degrees from the University of New England in 1983 and 1986; her mentors in these degrees were Ernie Bowen and Ivan Friš. She completed a PhD from the University of New South Wales in 1990. Her dissertation, Security of Statistical Databases, was supervised by Jennifer Seberry.
She held academic positions at the University of New England from 1982 to 1991, but after marrying graph theorist
Joe Ryan they both moved to the University of Newcastle. She was a faculty member at the University of Newcastle from 1992 to 2004, when she temporarily moved to the University of Ballarat, and returned to Newcastle as a research professor from 2008 until her retirement. At Newcastle, she spent many years as the only woman in the Faculty of Engineering. She retired as a professor emeritus in 2014.
She also held a position at the University of West Bohemia as Conjoint Professor since 2001.
She died of gastroesophageal cancer on 2 January 2016. A special issue of the Australasian Journal of Combinatorics was published in her honour in 2017, and special issues of the European Journal of Combinatorics and Journal of Discrete Algorithms followed in 2018.
Contributions
Miller was the author of two books on magic graphs, Super Edge-Antimagic Graphs: A Wealth of Problems and Some Solutions (with Martin Bača, BrownWalker Press, 2008), and (posthumously) Magic and Antimagic Graphs: Attributes, Observations and Challenges in Graph Labelings (with Bača, Joe Ryan, and Andrea Semaničová-Feňovčíková, Springer, 2019).
She wrote over 200 research publications, including a widely cited survey of the degree diameter problem, supervised 20 doctoral students before her death, was the supervisor of six more at the time of her death, and helped found four workshop series on algorithms, graph theory, and networks. She was also influential in the history of graph theory in Indonesia, where she visited twice and supervised six doctoral students.
An infinite family of vertex-transitive graphs with diameter two and a large number of vertices relative to their degree and diameter, the McKay–Miller–Širáň graphs, are named after Miller and her co-authors Brendan McKay and Jozef Širáň, who first constructed them in 1998. They include the Hoffman–Singleton graph as a special case.
References
External links
Home page
1949 births
2016 deaths
Australian women computer scientists
Australian mathematicians
Czech mathematicians
Czech women computer scientists
Women mathematicians
University of Sydney alumni
University of New England (Australia) alumni
University of New South Wales alumni
Academic staff of the University of New England (Australia)
Academic staff of the University of Newcastle (Australia)
Graph theorists | Mirka Miller | [
"Mathematics"
] | 739 | [
"Mathematical relations",
"Graph theory",
"Graph theorists"
] |
63,280,117 | https://en.wikipedia.org/wiki/Cel-Sci%20Corporation | Cel-Sci Corporation (NYSE American: CVM), is a biotechnology company that tests drugs for the treatment of cancer, autoimmune and infectious diseases through the research and development of immunotherapy products.
Cel-Sci's main product is the drug Multikine, an immunotherapeutic agent designed to fight cancer by stimulating the body's immune system. Multikine is currently in Phase III of Clinical Trials with the Food and Drug Administration (FDA). Multikine has also been referred to as Leukocyte Interleukin Injection (LI). Multikine was in Phase II testing of patients with head and neck cancer in the early 2000s, in which it demonstrated tumor-reducing ability. In January 2007, the US cleared the Phase 3 trial and Multikine was designated as an orphan drug by the FDA for neoadjuvant therapy of patients with squamous cell carcinoma of the head and neck. A total of 928 patients were enrolled in the head and neck cancer drug trial at that time. Subsequently, in June 2021, the company announced that the study missed its primary endpoint.
History
Cel-Sci Corporation was founded in 1983 in Germany by Maximilian de Clara of Switzerland, who was also the president of the company until his resignation in 2016. Geert Kersten, de Clara's stepson, has been the company's CEO since 1995. The company went public in the year of its founding. The investment firm that took the company public later folded.
The company's United States research and development operations were based in Baltimore, Maryland in the mid-1990s.
In May 1992, the U.S. Securities and Exchange Commission issued a cease and desist order against the company's then-President, Maximilian de Clara. This order stated that from August 1988 through June 1991, de Clara was 2–31 weeks late to file 16 forms documenting his sales of over $2.6 million of Cel-Sci stock.
CEO Geert Kersten confirmed that Cel-Sci paid an analyst from the brokerage firm of Honolulu Securities Inc. to write a research report on the company's stock, though the analyst claimed that being paid did not affect the conclusion that Cel-Sci's stock was undervalued.
In 1997, Cel-Sci bought a technology which enabled regulation of immune system responses that they had been licensing from the Dutch company Sittona.
Mysterious cash offer
The New York Times reported that in 1999, Cel-Sci received an unsolicited cash offer of $124 million from an unidentified person in Argentina.
Arbitration victory
In 2018, Cel-Sci won a 4.5-year-long arbitration suit filed in October 2013 against CRO InVentiv Health for breach of contract. The arbitrator awarded Cel-Sci $2.9 million in damages because the CRO failed to enroll the required number of patients over a period of 2 years, thus delaying the clinical development of Multikine. Later, the FDA lifted their clinical hold imposed on Cel-Sci in August 2017. This allowed the company to advance to Phase III of their head and neck cancer study.
2020 trading halt
On February 26, 2020, Cel-Sci's stock dropped 42.4% before a trading halt was issued for news pending. The company then released a letter to shareholders concerning the Phase III trial.
Multikine stage 3 study results
On June 28, 2021, Cel-Sci announced that the study missed its primary endpoint as the higher risk subgroup did not achieve a 10% improvement in overall survival even though the lower risk subgroup did. Kersten declared that the company would apply for FDA approval of the drug despite the study's missed endpoint. Following the announcement, Cel-Sci's stock lost between 40-50% of its value in one day as trading was halted at least 3 times.
Other products
Cel-Sci has also worked on LEAPS (Ligand Epitope Antigen Presentation System), a system of therapeutic vaccines for rheumatoid arthritis.
The company is also testing HGP-30 to determine if it is an effective treatment against the AIDS virus. In 1996, The Washington Post reported that the company was conducting its testing without the backing of the FDA because they couldn't agree on study details with said regulatory organization. Analysts were quoted as stating that this decision could cause the company delays in the event that it has to redo its research to meet FDA standards.
References
Pharmaceutical companies of the United States
Biotechnology companies established in 1983
Life sciences industry | Cel-Sci Corporation | [
"Biology"
] | 940 | [
"Life sciences industry"
] |
63,280,303 | https://en.wikipedia.org/wiki/Diphoterine | Diphoterine is a decontamination solution used in first aid for the emergency treatment of chemical spills to the eyes and body.
Mechanism of action
Diphoterine solution contains an amphoteric, chelating molecule: a substance which is capable of reacting with both acids and alkalis when applied to either type of chemical spill, stopping the aggressive action of a corrosive or irritant chemical, halting the reaction with the body.
However, it is not fully effective at halting the body's reaction with hydrofluoric acid. This is because hydrofluoric acid is poisonous as well as corrosive. Treatment with either Hexafluorine or calcium gluconate is required to deal with hydrofluoric acid contamination.
Like all of the emergency treatments, Diphoterine solution is not a substitute for professional medical attention, so immediate attention from emergency medical personnel should always be sought, especially if the chemical spill was to the eye.
Effectiveness
The efficacy of the Diphoterine solution has been shown to be effective in a two-year study on humans and also in a study on animals. Its effectiveness as compared to use of water alone, and therefore its necessity, has been questioned by some medical experts. On the other hand these statements do not provide any studies that compare the effectiveness of the Diphoterine solution compare to water.
The largest case series reported to date does compare the effectiveness of water and the Diphoterine solution. "One hundred eighty cases of alkali splashes to the skin were evaluated clinically. Two groups were compared; those who had applied Diphoterine first and those who had applied water first." Here are the results of this independent study: "There were no signs of chemical burn in 52.9% of the group who applied Diphoterine first compared with 21.4% of the group who applied water first. Only 7.9% of the group who applied Diphoterine first had blisters or more severe signs compared with 23.8% of the group who applied water first. The differences were statistically significant (P < 0.001). After implementation of Diphoterine the "first aid" injury rate for chemical burns fell 24.7% (95% CI 0.5–43.0%)."
See also
DeconGel
Eyewash
Amphoteric compounds
References | Diphoterine | [
"Chemistry"
] | 482 | [
"Acids",
"Amphoteric compounds",
"Bases (chemistry)",
"Physical chemistry stubs"
] |
63,280,688 | https://en.wikipedia.org/wiki/HH%20111 | HH 111 is a Herbig-Haro object in the L1617 dark cloud of the Orion B molecular cloud in the constellation of Orion. It is a prototype of a highly collimated optical jet sources. It shows several bow shocks and has a length of about 2.6 light-years (0.8 parsec).
HH 111 is about 1300 light years (400 parsec) distant from earth and the central source is IRAS 05491+0247, also called VLA 1. This source is the driving source of the jets and it is a class I protostar with a luminosity of about 25 . This protostar is embedded in a 30 cloud core. The dynamical age of the complex is only 800 years. Near the central source an ammonia feature called NH3-S was found, which is a starless core with a turbulent interior induced by HH 111.
The jets move with a speed of 300 - 600 km/s and consist of a blueshifted component, which is bright in optical wavelengths and a redshifted faint counterjet. A second pair of bipolar jets, called HH 121 was discovered in the near-infrared at an angle of 61° compared to the HH 111 pair. This was taken as evidence for a system with multiple protostars.
Gallery
References
External links
Animations of HH object jets from HST observations
Geometry of the multiple star system (from 2000)
Herbig–Haro objects
Orion (constellation)
Orion molecular cloud complex | HH 111 | [
"Astronomy"
] | 311 | [
"Constellations",
"Orion (constellation)"
] |
63,281,413 | https://en.wikipedia.org/wiki/Sug%20Woo%20Shin | Sug Woo Shin is a professor of mathematics at the University of California, Berkeley working in number theory, automorphic forms, and the Langlands program.
Education
From 1994 to 1996 when he was in Seoul Science High School, Shin won two gold medals (including a perfect score in 1995) and one bronze medal while representing South Korea at the International Mathematical Olympiad.
He graduated from Seoul National University with a Bachelor of Science degree in mathematics in 2000. He received his PhD in mathematics from Harvard University in 2007 under the supervision of Richard Taylor.
Career
Shin was a member of the Institute for Advanced Study from 2007 to 2008, a Dickson Instructor at the University of Chicago from 2008 to 2010, and again a member at the Institute for Advanced Study from 2010 to 2011. He was an assistant professor of mathematics at the Massachusetts Institute of Technology from 2011 to 2014. In 2014, Shin moved to the Department of Mathematics at the University of California, Berkeley as an associate professor. In 2020, Shin became a full professor of mathematics at the University of California, Berkeley.
Shin is a visiting KIAS scholar at the Korea Institute for Advanced Study and a visiting associate member of the Pohang Mathematics Institute.
Research
In 2011, Michael Harris and Shin resolved the dependencies on improved forms of the Arthur–Selberg trace formula in the conditional proofs of generalizations of the Sato–Tate conjecture by Harris (for products of non-isogenous elliptic curves) and Barnet-Lamb–Geraghty–Harris–Taylor (for arbitrary non-CM holomorphic modular forms of weight greater than or equal to two).
Awards
Shin received a Sloan Fellowship in 2013.
Selected publications
References
External links
20th-century South Korean mathematicians
21st-century South Korean mathematicians
Number theorists
Living people
Date of birth missing (living people)
Place of birth missing (living people)
University of California, Berkeley faculty
Harvard University alumni
Seoul National University alumni
Massachusetts Institute of Technology School of Science faculty
University of Chicago faculty
Sloan Research Fellows
Year of birth missing (living people)
International Mathematical Olympiad participants | Sug Woo Shin | [
"Mathematics"
] | 409 | [
"Number theorists",
"Number theory"
] |
63,281,547 | https://en.wikipedia.org/wiki/HH%2024-26 | HH 24-26 is a molecular cloud and star-forming region containing the Herbig-Haro objects HH 24, HH 25 and HH 26. This region contains the highest concentration of astrophysical jets known anywhere in the sky. The molecular cloud is located about 1400 light-years away in the L1630 dark cloud, which is part of the Orion B molecular cloud in the constellation of Orion.
The region contains multiple protostars (two class 0 and one class I) and four more evolved IRAS sources. The three protostars are driving the Herbig-Haro objects in this region.
Observation
The L1630 dark cloud also contains NGC 2071 and the Flame Nebula. HH 24-26 is located just a few arcminutes south of Messier 78.
HH 24
The image of HH 24 taken by the Hubble Space Telescope is probably the most well known image of this Herbig-Haro object. HH 24 resembles a lightsaber from the science fiction movies Star Wars and the Hubble image was published during the release of Star Wars Episode VII: The Force Awakens.
HH 24 contains a class 0 protostar, which might be a proto-binary system. The disks around these objects are highly misaligned, which is a sign of turbulent fragmentation.
See also
Astronomy Picture of the Day
References
External links
APOD: 2014 February 4 - A Particle Beam Jet forms HH 24
APOD: 2015 December 18 - Herbig-Haro 24
APOD: 2018 March 11 - Dual Particle Beams in Herbig-Haro 24
Herbig–Haro objects
Orion (constellation)
Orion molecular cloud complex
Reflection nebulae
Molecular clouds | HH 24-26 | [
"Astronomy"
] | 345 | [
"Constellations",
"Orion (constellation)"
] |
63,283,296 | https://en.wikipedia.org/wiki/Dawn%20Bonnell | Dawn Austin Bonnell is the Senior Vice Provost for Research at the University of Pennsylvania. She has previously served as the Founding Director of the National Science Foundation Nano–Bio Interface Center, Vice President of the American Ceramic Society and President of the American Vacuum Society. In 2024, she was elected to the American Philosophical Society.
Early life and education
Bonnell grew up in suburban Detroit. She was the eldest of four children. She deferred applying to college until she had started her own family, but, seven years later, found herself a single mother in need of more education to support her own children. At the time Bonnell lived next door to the University of Michigan, and eventually applied to study there. Bonnell specialized in materials science and engineering at the University of Michigan. Bonnell particularly enjoyed the chemistry aspects of her introductory science courses. She earned her bachelor's degree in 1983 and her PhD under the supervision of Tseng-Ying Tien in 1986. Her doctoral research involved identifying stable phases of silicon nitride systems, with a focus on improving the mechanical properties at high temperature. She spent a year at the Max Planck Institute for Solid State Research – with her two children – where she worked with Manfred Ruehle on electron microscopy. She was a postdoctoral scholar at the Thomas J. Watson Research Center. The research centre was home to the first scanning tunnelling microscope, and Bonnell appreciated the potential of scanning tunnelling microscopy as a means to accelerate our understanding of ceramics.
Research and career
In 1988 Bonnell joined the faculty of the University of Pennsylvania. Her research has involved investigations into the structure-property relations of ceramic materials as well as studies into how the surface morphology impacts chemical reactions. Her research group were the first to successfully image oxide surfaces with atomic resolution, which they achieved using scanning probe microscopy. She has also investigated ferroelectric compounds, synthetic proteins and quantum dots. The ability to visualize the atomic structure of surfaces and interfaces, and has applications in catalysis, biosensing and nanofabrication.
In 2004 Bonnell founded the University of Pennsylvania Nano/Bio Interface Center (NBIC), which supports collaboration between researchers working at the intersection of biology, chemistry and technology. As part of NBIC, Bonnell developed a new nanotechnology program for undergraduate students at the University of Pennsylvania. NBIC is home to several scanning probe-equipment facilities, and can support research in the life sciences as well as emerging technologies.
Bonnell was made Vice Provost for Research in 2013. She was also elected a member of the National Academy of Engineering in 2013 for the development of atomic-resolution surface probes, and for institutional leadership in nanoscience.
Awards and honours
National Science Foundation Presidential Young Investigator Award
American Ceramic Society Robert B. Sosman Award
American Ceramic Society Ross Coffin Purdy Award
University of Michigan Distinguished Alumni Award
American Ceramic Society Distinguished Member
George H. Heilmeier Award for Excellence in Faculty Research
Elected Fellow of the American Association for the Advancement of Science
Elected Fellow of the American Ceramic Society
Elected to the National Academy of Engineering
Elected Fellow of the Materials Research Society
ETH Zürich Staudinger-Durrer Medal
Selected publications
Imaging mechanism of piezoresponse force microscopy of ferroelectric surfaces (DOI:10.1103/PhysRevB.65.125408)
Local potential and polarization screening on ferroelectric surfaces (DOI:10.1103/PhysRevB.63.125411)
Local impedance imaging and spectroscopy of polycrystalline ZnO using contact atomic force microscopy (DOI:10.1063/1.1561168)
References
Living people
Year of birth missing (living people)
Women materials scientists and engineers
American materials scientists
American women engineers
University of Pennsylvania faculty
University of Michigan alumni
American women academics
21st-century American women
Members of the American Philosophical Society | Dawn Bonnell | [
"Materials_science",
"Technology"
] | 783 | [
"Women materials scientists and engineers",
"Materials scientists and engineers",
"Women in science and technology"
] |
63,283,325 | https://en.wikipedia.org/wiki/Ackermannviridae | Ackermannviridae is a family of viruses in the class Caudoviricetes. Gammaproteobacteria in the phylum Pseudomonadota serve as natural hosts. There are two subfamilies, ten genera, and 63 species in the family.
Etymology
The family's name, Ackerman is in honor of Hans-Wolfgang Ackermann (1936–2017), a German microbiologist, the suffix -viridae is the standard suffix for virus families.
Taxonomy
The following taxa are recognized (-virinae denotes subfamily and -virus denotes genus):
Aglimvirinae
Agtrevirus
Limestonevirus
Cvivirinae
Kuttervirus
incertae sedis genera:
Campanilevirus
Kujavirus
Miltonvirus
Nezavisimistyvirus
Taipeivirus
Tedavirus
Vapseptimavirus
References
External links
ViralZone
Virus families | Ackermannviridae | [
"Biology"
] | 181 | [
"Virus stubs",
"Viruses"
] |
63,284,639 | https://en.wikipedia.org/wiki/Gender%20digital%20divide | Gender digital divide is defined as gender biases coded into technology products, technology sector, and digital skills education. It can refer to women's and other gender identity's use of, and professional development in computing work. The gender digital divide has changed throughout history due to social roles, economics, and educational opportunities. As the gender spectrum continues to exist more prominently in social and professional spaces, the inclusion of other identities is an important area of concern in these types of conversations. These other identities can include any other than cis-gender male. Non-binary people make up a significant portion of the population and their existence is affected by the digital divide nonetheless.
Background
Education systems are increasingly trying to ensure equitable, inclusive, and high-quality digital skills, education, and training. Though digital skills open pathways to further learning and skills development, women and girls are still being left behind in digital skills education. Globally, digital skills gender gaps are growing, despite at least a decade of national and international efforts to close them. The economic and political interests of its indicators have also been questioned.
Digital skills gap
Women are less likely to know how to operate a smartphone, navigate the internet, use social media and understand how to safeguard information in digital mediums (abilities that underlie life and work tasks and are relevant to people of all ages) worldwide. There is a gap from the lowest skill proficiency levels, such as using apps on a mobile phone, to the most advanced skills like coding computer software to support the analysis of large data sets.
Women in numerous countries are 25% less likely than men to know how to leverage ICT for basic purposes, such as using simple arithmetic formulas in a spreadsheet. UNESCO estimates that men are around four times more likely than women to have advanced ICT skills such as the ability to programme computers. Across G20 countries 7% of ICT patents are generated by women, and the global average is at 2%. Recruiters for technology companies in Silicon Valley estimate that the applicant pool for technical jobs in artificial intelligence (AI) and data science is often less than 1% female. To highlight this difference, in 2009 there were 2.5 million college-educated women working in STEM compared to 6.7 million men. The total workforce at the time was 49% women and 51% men which highlights the evident gap.
While the gender gap in digital skills is evident across regional boundaries and income levels, it is more severe for women who are older, less educated, poor, or living in rural areas and developing countries. Making women much less likely to graduate in any field of STEM compared to their male counterpart. Digital skills gap intersects with issues of poverty and educational access.
Root causes
Women and girls who live in patriarchal cultures may struggle more than those who do not to access public ICT facilities. Due to the social challenges these cultures create as well reinforces the struggles and creates an overlap. They may struggle to access these facilities due to unsafe roads, limits on their freedom of movement, or because the facilities themselves are considered unsuitable for women. They may also lack financial freedom creating a large barrier to purchase any form of technology or have any type of internet connection. If they do have access to technology of the internet, it is usually controlled by the men in their households and limit their content selection to content focused on women's appearances, dating, or the role of motherhood. Fears concerning safety and harassment (both online and offline) also inhibit many women and girls from benefiting from or even wanting to use ICTs.
In many contexts, women and girls face concerns of physical violence if they own or borrow digital devices, which in some cases leads to their using the devices in secret, making them more vulnerable to online threats and making it difficult to gain digital skills.
The stereotype of technology as a male domain is common in many contexts and affect girls' confidence in their digital skills from a young age. In OECD countries, 0.5% of girls aspire towards ICT-related careers at age 15, versus 5% of boys. This was not always the case. Early decades of computing saw a much larger presence of women. Acting as programmers during World War II, they held highly valued positions. Women's contributions, however, have been largely obscured due to how the history is told. Focusing on the infrastructure and hardware of digital technologies development has placed men at the forefront of its history. Post war computer manufacturers sought to commercialize the machines and opened up a new form of labor market. This post war market utilized discriminatory criteria measures that women were no longer able to meet due to societal, educational, and labor expectations. Managers of early technology firms allowed women well-suited for programming because of stereotypes characterizing them as meticulous and good at following step-by-step directions. Women, including many women of color, flocked to jobs in the computer industry because it was seen as more meritocratic than other fields. As computers became integrated into people's daily life, it was noticed that programmers had influence. Consequently, women were pushed out and the field became more male-dominated.
In developed countries like Canada, the digital divide can exist due to factors of lacking digital literacy which prevents individuals from understanding how to use and what to do with technology. Other research on the gender divide in Canada has found contrasting results, showing a potential suggestion to the closing of the gap in more developed countries over the last couple years in relation to access to the internet and technology as a whole. However, the amount of activity online is found to be higher for men than women. When looking at issues regarding professional sectors the IT sector in Canada remains male-dominated. The presence of women in field with technology has increased significantly but in specific high-paying technological fields like computer science it is declining.
Access divide versus skills divide
Due to the declining price of connectivity and hardware, skills deficits have exceeded barriers of access as the primary contributor to the gender digital divide. For years, the divide was assumed to be symptomatic of technical challenges. It was thought that women would catch up with men when the world had cheaper devices and lower connectivity prices, due to the limited purchasing power and financial independence of women compared with men in countries with a patriarchal culture. The cost of ICT access remains an issue and is surpassed by educational gaps. For example, the gender gap in internet penetration is around 17% in the Arab States and the Asia and Pacific region, whereas the gender gap in ICT skills is as high as 25% in some Asian and Middle Eastern countries. In sub-Saharan Africa (SSA), the Internet penetration rate in 2019 was 33.8 percent for men and 22.6 percent for women. The Internet user gender gap was 20.7 percent in 2013 and up to 37 percent in 2019. The Internet penetration rate in 2019 was 33.8 percent for men and 22.6 percent for women.
Other research has shown more factors that contribute to access of the internet. In the United States, it was found that individuals who has lower than high school education and made less than $30k a year has the lowest access to the internet. They found that the most consistent results form various research is that individuals with the lowest education and lowest income had the lowest access to the internet. When looking at differences with gender, inconsistent results were found. When large divides were found between men and women' access to the internet, socioeconomic factors were the cause. Overall, the gender divide has found to be largely insignificant in countries like the United States and in Canada.
SSA has one of the widest mobile gender gaps in the world where over 74 million women are not connected. The gender gap in mobile ownership was 13 percent, a reduction from 14 percent in 2018; however, in low- and middle-income countries it remains substantial with fewer women than men accessing the Internet on a mobile device. Furthermore, women are less likely to use digital services or mobile Internet and tend to use different mobile services than men.
Many people have access to affordable devices and broadband networks, but do not have the requisite skills to take advantage of this technology to improve their lives. In Brazil, lack of skills (rather than cost of access) was found to be the primary reason low-income groups are not using the internet. In India, where lack of skills and lack of need for the internet were the primary limiting factors across all income groups.
Lack of understanding, interest or time is a bigger issue than affordability or availability as the reason for not using the internet. Even though skills deficits prevent both men and women from using digital technologies, they tend to be more severe for women. In a study conducted across 10 low- and middle-income countries, women were 1.6 times more likely than men to report lack of skills as a barrier to internet use. Women are also more likely to report that they do not see a reason to access and use ICT. Interest and perception of need are related to skills, as people who have little experience with or understanding of ICTs tend to underestimate their benefits and utility.
Relationship between digital skills and gender equality
In many societies, gender equality does not translate into digital realms and professions. The persistence of growing digital skills gender gaps, even in countries that rank at the top of the World Economic Forum's global gender gap index (reflecting strong gender equality), demonstrates a need for interventions that cultivate the digital skills of women and girls.
For most countries, the primary barriers for women regarding access to digital technology are cost/unaffordability followed by illiteracy and lack of digital skills. For instance, in Africa 65.4 percent of people aged 15 and older are illiterate, compared to the global average rate of 86.4 percent.
Gender digital divide and COVID-19
Africa
The COVID-19 pandemic and the measures taken by governments on social distancing and mobility restrictions have contributed to boosting the use of digital technology to bridge some of the physical access gaps. However, the rapid proliferation of digital tools and services stands in stark contrast to the many systemic and structural barriers to technology access and adoption that many people in rural Africa still face. Gender inequalities, intersecting with and compounded by other social differences such as class, race, age, (dis)ability, etc., shape the extent to which different rural women and men are able not only to access but also use and benefit from these new technologies and ways of delivering information and services.
Beside the potential of digital tools and applications, the COVID-19 crisis has evidenced the existing digital divide and especially the gender gap. It is estimated that 3.6 billion individuals are not connected to the Internet across the globe, including 900 million in Africa. Only 27 percent of women in Africa have access to the Internet and only 15 percent of them can afford to use it.
Gender-responsive digitalization in COVID-19 response
According to a study by FAO, gender-responsive digitalization in COVID-19 response and beyond could include:
Improve the availability of sex-disaggregated data and gender-related statistics that capture digital gender gaps in rural areas to better inform policy and business decisions
Promote an enabling environment that includes gender-responsive policies, strategies and initiatives
Leverage digital solutions to deliver COVID-19 relief measures targeted to rural women and girls and facilitate their access to social protection services and alternative income-generation opportunities.
Dedicate funds for digital acceleration to support women-led enterprises.
Improve the national broadband coverage to ensure affordable, accessible and reliable infrastructure for inclusive digital transformation
Invest in the protection of Internet users, especially illiterate and vulnerable ones, against frauds and abuses as cybercrime, including sexual harassment. According to UN Women, these crimes have reportedly increased during the COVID-19 pandemic, especially toward women and girls.
Benefits of digital empowerment
Helping women and girls develop digital skills means stronger women, stronger families, stronger communities, stronger economies and better technology. Digital skills are recognized to be essential life skills required for full participation in society. The main benefits for acquiring digital skills are they:
Facilitate entry into the labour market;
Assist women's safety both online and offline;
Enhance women's community and political engagement;
Bring economic benefits to women and society;
Empower women to help steer the future of technology and gender equality;
Accelerate progress towards international goals.
Digitalization can potentially pave the way for improving the efficiency and functioning of food systems, which in turn can have positive impacts on the livelihoods of women and men farmers and agripreneurs, for example, through the creation of digital job opportunities for young women and men in rural areas.
Closing the digital skills gender gap
The digital divide has begun at earlier ages as young adults have lived out their childhoods with personal computers. This has made intervention to prevent further gender divides in the digital realm needed in more early education. Increasing girls' and women's digital skills involves early, varied and sustained exposure to digital technologies. Interventions should not be limited to formal education settings, they should reflect a multifaceted approach, enabling women and girls to acquire skills in a variety of formal and informal contexts (at home, in school, in their communities and in the workplace). The digital divide cuts across age groups, therefore solutions need to assume a lifelong learning orientation. The technological changes adds impetus to the 'across life' perspective, as skills learned today will not necessarily be relevant in 5 or 10 years. Digital skills require regular updating, to prevent women and girls fall further behind.
Women and girls digital skills development are strengthened by:
Adopting sustained, varied and life-wide approaches;
Establishing incentives, targets and quotas;
Embedding ICT in formal education;
Supporting engaging experiences;
Emphasising meaningful use and tangible benefits;
Encouraging collaborative and peer learning;
Creating safe spaces and meet women where they are;
Examining exclusionary practices and language;
Recruiting and training gender-sensitive teachers;
Promoting role models and mentors;
Bringing parents on board;
Leveraging community connections and recruiting allies;
Supporting technology autonomy and women's digital rights.
According to the Food and Agriculture Organization (FAO), there are seven success factors to empowering rural women through ICTs:
Adapt content so that it is meaningful for them.
Create a safe environment for them to share and learn.
Be gender-sensitive.
Provide them with access and tools for sharing
Build partnerships.
Provide the right blend of technologies.
Ensure sustainability
The regulatory role of governments (at local, national, regional, and international levels) is crucial in addressing infrastructural barriers, harmonizing and making the regulatory environment inclusive and gender-responsive, and in protecting all stakeholders from fraud and crime.
Initiatives targeted at boosting women's representation in the technology industry are essential to closing the digital skills gender divide. Mentorship programs, networking chances, and scholarships for women seeking jobs in technology are examples of such initiatives. These efforts can help create more inclusive workplaces that respect diversity and promote creativity by boosting the presence of women in the technology industry.
Mentorship programs can be especially beneficial in assisting women in the technology industry. These initiatives allow women to network with experienced professionals who can give advice and support as they advance in their jobs. According to research, mentoring programs can help increase women's confidence and feeling of connection in the workplace, which can improve job happiness and professional growth opportunities.
Women in technology can benefit from networking chances as well. Women can benefit from networking by developing connections with other professionals in their industry, which can lead to new employment possibilities and collaborations. Networking can also assist women in staying current with the newest trends and technologies in their profession.
Scholarships can also be a good method to help women who want to work in technology. Scholarships can assist in covering the costs of education and training, making it simpler for women to gain the skills and knowledge required to thrive in the technology industry. Scholarships can also help to increase gender variety in the technology industry by encouraging more women to enter the profession.
Overall, initiatives targeted at boosting women's representation in the technology industry are essential to closing the digital skills gender divide. We can build more inclusive and innovative environments that help everyone if we assist women in technology.
Female gendering of AI technologies
Men continue to dominate the technology space, and the disparity serves to perpetuate gender inequalities, as unrecognized bias is replicated and built into algorithms and artificial intelligence (AI).
Limited participation of women and girls in the technology sector can stem outward replicating existing gender biases and creating new ones. Women's participation in the technology sector is constrained by unequal digital skills education and training. Learning and confidence gaps that arise as early as primary school amplify as girls move through education, therefore by the time they reach higher education only a fraction pursue advanced-level studies in computer science and related information and communication technology (ICT) fields. Divides grow greater in the transition from education to work. The International Telecommunication Union (ITU) estimates that only 6% of professional software developers are women.
Technologies generated by male-dominated teams and companies often reflect gender biases. Establishing balance between men and women in the technology sector will help lay foundations for the creation of technology products that better reflect and ultimately accommodate the rich diversity of human societies. For instance AI, which is a branch of the technology sector that wields influence over people's lives. Today, AI curates information shown by internet search engines, determines medical treatments, makes loan decisions, ranks job applications, translates languages, places ads, recommends prison sentences, influences parole decisions, calibrates lobbying and campaigning efforts, intuits tastes and preferences, and decides who qualifies for insurance, among other tasks. Despite the growing influence of this technology, women make up just 12% of AI researchers. Closing the gender divide begins with establishing more inclusive and gender-equal digital skills education and training.
Digital assistants
Digital assistants encompass a range of internet-connected technologies that support users in various ways. When interacting with digital assistants, users are not restricted to a narrow range of input commands, but are encouraged to make queries using whichever inputs seem most appropriate or natural, whether they are typed or spoken. Digital assistants seek to enable and sustain more human-like interactions with technology. Digital assistants can include: voice assistants, chatbots, and virtual agents.
Feminization of voice assistants
Voice assistants have become central to technology platforms and, in many countries, to day-to-day life. Between 2008 and 2018, the frequency of voice-based internet search queries increased 35 times and account for close to one fifth of mobile internet searches (a figure that is projected to increase to 50% by 2020). Voice assistants now manage upwards of 1 billion tasks per month, from the mundane (changing a song) to the essential (contacting emergency services).
Today, most leading voice assistants are exclusively female or female by default, both in name and in sound of voice. Amazon has Alexa (named for the ancient library in Alexandria), Microsoft has Cortana (named for a synthetic intelligence in the video game Halo that projects itself as a sensuous unclothed woman), and Apple has Siri (coined by the Norwegian co-creator of the iPhone 4S and meaning 'beautiful woman who leads you to victory' in Norse). While Google's voice assistant is simply Google Assistant and sometimes referred to as Google Home, its voice is female.
The trend to feminize assistants occurs in a context in which there is a growing gender imbalance in technology companies, such that men commonly represent two thirds to three quarters of a firm's total workforce. Companies like Amazon and Apple have cited academic work demonstrating that people prefer a female voice to a male voice, justifying the decision to make voice assistants female. Further research shows that consumers strongly dislike voice assistants without clear gender markers. Gender bias is thus "hard-coded" into technology. Companies often cite research showing that customers want their digital assistants to sound like women, justifying the choice with the profit motive. However, research on the topic is mixed, with studies showing that in some contexts male choices may be preferred. For example, BMW was forced to recall a female-voiced navigation system on its 5 Series cars in the late 1990s after being flooded with calls from German men who reportedly "refused to take directions from a woman".
Researchers who specialize in human–computer interaction have recognized that both men and women tend to characterize female voices as more helpful. The perception may have roots in traditional social norms around women as nurturers (mothers often take on – willingly or not – significantly more care than fathers) and other socially constructed gender biases that predate the digital era.
See also
AI alignment
Artificial intelligence detection software
Digital divide
Gender disparity in computing
Female education
Women's empowerment
Sources
References
Gender studies
Information technology
Artificial intelligence | Gender digital divide | [
"Technology"
] | 4,240 | [
"Information and communications technology",
"Information technology"
] |
63,286,746 | https://en.wikipedia.org/wiki/Symmetry%20in%20Mechanics | Symmetry in Mechanics: A Gentle, Modern Introduction is an undergraduate textbook on mathematics and mathematical physics, centered on the use of symplectic geometry to solve the Kepler problem. It was written by Stephanie Singer, and published by Birkhäuser in 2001.
Topics
The Kepler problem in classical mechanics is a special case of the two-body problem in which two point masses interact by Newton's law of universal gravitation (or by any central force obeying an inverse-square law). The book starts and ends with this problem, the first time in an ad hoc manner that represents the problem using a system of twelve variables for the positions and momentum vectors of the two bodies, uses the conservation laws of physics to set up a system of differential equations obeyed by these variables, and solves these equations. The second time through, it describes the positions and variables of the two bodies as a single point in a 12-dimensional phase space, describes the behavior of the bodies as a Hamiltonian system, and uses symplectic reductions to shrink the phase space to two dimensions before solving it to produce Kepler's laws of planetary motion in a more direct and principled way.
The middle portion of the book sets up the machinery of symplectic geometry needed to complete this tour. Topics covered in this part include manifolds, vector fields and differential forms, pushforwards and pullbacks, symplectic manifolds, Hamiltonian energy functions, the representation of finite and infinitesimal physical symmetries using Lie groups and Lie algebras, and the use of the moment map to relate symmetries to conserved quantities. In these topics, as well, concrete examples are central to the presentation.
Audience and reception
The book is written as a textbook for undergraduate mathematics and physics students, with many exercises, and it assumes that the students are already familiar with multivariable calculus and linear algebra, a significantly lower level of background material than other books on symplectic geometry in mechanics. It is not comprehensive in its coverage of symplectic geometry and mechanics, but could be used as auxiliary reading in a class that covers that material from other sources, such as Abraham and Marsden's Foundations of Mechanics or Arnold's Mathematical Methods of Classical Mechanics. Alternatively, on its own, it can provide a more accessible first course in this material, before presenting it more comprehensively in another course.
Reviewer William Satzer writes that this book "makes serious efforts to address real students and their potential difficulties" and shifts comfortably between mathematical and physical views of its problem. Similarly, reviewer J. R. Dorfman writes that it "removes some of the language barriers that divide the worlds of mathematics and physics", and reviewer Jiří Vanžura calls it "remarkable" in its dual ability to motivate mathematical methods for physics students and provide applications in physics for mathematics students, adding that "The book is perfectly written and serves very well its purpose." Reviewer Ivailo Mladenov notes with approval the book's attention to example-first exposition, and despite pointing to a minor inaccuracy regarding the nationality of Sophus Lie, recommends it to both undergraduate and graduate students. Reviewer Richard Montgomory writes that the book does "an excellent job of leading the reader from the Kepler problem to a view of the growing field of symplectic geometry".
References
Hamiltonian mechanics
Mathematics textbooks
2001 non-fiction books | Symmetry in Mechanics | [
"Physics",
"Mathematics"
] | 691 | [
"Hamiltonian mechanics",
"Theoretical physics",
"Classical mechanics",
"Dynamical systems"
] |
63,287,494 | https://en.wikipedia.org/wiki/Jim%20Browning%20%28YouTuber%29 | Jim Browning is the Internet alias of a software engineer and YouTuber from Northern Ireland whose content focuses on scam baiting and investigating call centres engaging in fraudulent activities. Browning cooperates with other YouTubers and law enforcement when they seek his expertise in investigating and infiltrating scam call centers. Browning has published several journalistic exposé videos highlighting the results of his investigations.
Scambaiting
A software engineer, Browning began researching scam operations after his relative lost money to a technical support scam. He started his YouTube channel to upload footage to send to authorities as evidence against scammers.
He has since carried out investigations into various scams, in which he infiltrates computer networks run by scammers who claim to be technical support experts or pose as US IRS agents and use remote desktop software or social engineering. Such scams have involved unsolicited calls offering computer services, or websites posing to be reputable companies such as Dell or Microsoft.
BBC Panorama investigation
Browning was featured in a March 2020 episode of British documentary series Panorama, in which a large-scale technical support scamming operation was infiltrated and extensively documented by Browning and fellow YouTuber Karl Rock. The duo recorded drone and CCTV footage of the facility in Gurugram, Haryana, India and gathered incriminating evidence linking alleged scammer Amit Chauhan, who also operated a fraudulent travel agency called "Faremart Travels", to a series of scams targeting computer-illiterate and elderly people in the United Kingdom and United States. During a private meeting with his associates, Chauhan was quoted as stating, "We don't give a shit about our customers". Some of his call centre agents were recorded scamming and laughing at a British man who admitted to being depressed. They were also recorded conning a blind woman with diabetes. Chauhan denied the allegations in a phone interview with the BBC, and he was arrested along with his accountant Sumit Kumar in a raid by Delhi Police. On 2 May 2022, Chauhan was acquitted of all charges at a court hearing in Gurugram and released.
Money-mule catching
In March 2021, Browning and fellow YouTuber Mark Rober collaborated to construct and distribute automated glitter bombs to identify and report money mules who were receiving their money via shipping services, such as FedEx, before sending it to scammers.
New York Times interview
Browning was covered in a 2021 New York Times article documenting their confrontation of a small-scale refund scam operation based in Kolkata, India. The journalist, Yudhijit Bhattacharjee, a native of Kolkata who moved to the United States, described a December 2019 scam-baiting operation by Browning, during which Browning intercepted a refund scam involving an elderly woman. Suspicious, the woman told the scammer that she would cease contact with him, only for the scammer to lock her computer. Browning was able to contact the woman and help her unlock the computer. Bhattacharjee later flew to India to check out call centers that Browning had identified as possible scammers and to confront the individual who had perpetrated the refund scam on the elderly woman.
AARP report
The April 2021 issue of the American Association of Retired Persons (AARP) Bulletin contains an 11-page article by the director of AARP's Washington state office, centering on Browning's work fighting cyber scams.
Temporary channel deletion
On 26 July 2021, Browning was targeted by scammers who pretended to be YouTube support staff and misled him into deleting his own channel. His channel was reinstated four days later. He explained in a video that the scammer used Google Chat to send an authenticated phishing email from the "google.com" domain and convinced Browning to delete his channel under the pretense of moving it to a new YouTube brand account.
Scam Interceptors
In 2022, BBC commissioned for a television series for BBC One, Scam Interceptors, presented by Rav Wilding. In the series, Browning and a team of white hat hackers attempt to intercept criminals and prevent fraudulent activity. The first series premiered on 4 April 2022, and the second on 1 May 2023.
Awards and nominations
Notes
References
External links
Activists from Northern Ireland
British computer specialists
British software engineers
English-language YouTube channels
Fraud in India
Hackers
Hacking in the 2010s
Hacking in the 2020s
Internet vigilantism
Living people
Social engineering (security)
Technology YouTubers
Unidentified people
Year of birth missing (living people)
YouTube channels launched in 2014
YouTubers from Northern Ireland | Jim Browning (YouTuber) | [
"Technology"
] | 942 | [
"Lists of people in STEM fields",
"Hackers"
] |
63,288,122 | https://en.wikipedia.org/wiki/2-Phosphoglycolate | 2-Phosphoglycolate (chemical formula C2H2O6P3-; also known as phosphoglycolate, 2-PG, or PG) is a natural metabolic product of the oxygenase reaction mediated by the enzyme ribulose 1,5-bisphosphate carboxylase (RuBisCo).
Synthesis
RuBisCo catalyzes the fixation of atmospheric carbon dioxide in the chloroplasts of plants. It uses ribulose 1,5-bisphosphate (RuBP) as substrate and facilitates carboxylation at the C2 carbon via an endiolate intermediate. The two three-carbon products (3-phosphoglycerate) are subsequently fed into the Calvin cycle. Atmospheric oxygen competes with this reaction. In a process called photorespiration RuBisCo can also catalyze addition of atmospheric oxygen to the C2 carbon of RuBP forming a high energy hydroperoxide intermediate that decomposes into 2-phosphoglycolate and 3-phosphoglycerate. Despite a higher energy barrier for the oxygenation reaction compared to carboxylation, photorespiration accounts for up to 25% of RuBisCo turnover in C3 plants.
Biological role
Plants
In plants, 2-phosphoglycolate has a potentially toxic effect as it inhibits a number of metabolic pathways. The activities of important enzymes in the central carbon metabolism of the chloroplast such as triose-phosphate isomerase, phosphofructokinase, or sedoheptulose 1,7-bisphosphate phosphatase show a significant decrease in the presence of 2-PG. Therefore, degradation of 2-PG during photorespiration is important for cellular homeostasis.
Photorespiration is the main way of chloroplasts to rid themselves of 2-PG. However, this pathway comes at a decreased return on investment ratio as 2-PG is transformed to 3-phosphoglycerate in an elaborate salvage pathway at the cost of one equivalent of NADH and ATP, respectively. In addition, this salvage pathway loses ½ equivalent of previously fixed carbon dioxide and releases ½ equivalent of toxic ammonia per molecule of 2-PG. This leads to a net loss of carbon in photorespiration, making it much less efficient than the Calvin cycle.
However, this salvage pathway can also act as a cellular energy sink, preventing the chloroplastidal electron transport chain from over reduction. It is believed that this pathway also plays a role in improving the abiotic stress response of plants.
Bacteria
2-PG is similarly a toxic product in bacteria. Bacteria remove this substance using a glycerate pathway. This shorter pathway branches out from photorespiration after the formation of glyoxylate, proceeding to use glycoxylate carboxylase and tartronic semialdehyde reductase to rejoin at the formation of glycerate. Some Cyanobacteria can use a combination of photorespiration and glycerate pathways.
Transferring the shorter glycerate pathway into plant chloroplasts, combined with stopping chloroplastic export of glycolate, results in higher photosynthetic efficiency. In tobacco, the biomass increases by 13%, not as good a result as a designed pathway.
Animals
Although mainly produced in plants, 2-PG also plays a role in mammalian metabolism, though the source of 2-PG in mammals remains incompletely understood. It is thought that the processing of breaks in the DNA-strand produces small amounts of 2-PG, but other processes may yield 2-PG as well. The phosphatase subunit of bisphosphoglycerate mutase, an enzyme found in red blood cells, shows an increase in activity by up three orders of magnitude in the presence of 2-PG, resulting in an increase of the oxygen affinity of hemoglobin.
Agricultural significance
RuBisCo has been a potential target for bioengineers for agricultural purposes. A decrease in the oxygenation of RuBP may result in a boost in the efficiency of carbon assimilation in crops such as rice or wheat and therefore increase their net biomass production. Attempts have been made to artificially alter the protein structure of RuBisCo to enhance its catalytic turnover rate. Mutations in the L-subunit of the enzyme, for example, have been shown to increase both the catalytic turnover rate and RuBisCos affinity for carbon dioxide
References
Organophosphates
Organic acids | 2-Phosphoglycolate | [
"Chemistry"
] | 944 | [
"Organic acids",
"Acids",
"Organic compounds"
] |
63,288,301 | https://en.wikipedia.org/wiki/Kathy%20Horadam | Kathryn Jennifer Horadam (born 1951) is an Australian mathematician known for her work on Hadamard matrices and related topics in mathematics and information security. She is an Emeritus Professor at the Royal Melbourne Institute of Technology (RMIT).
Life
Horadam is one of the three children of mathematicians Alwyn Horadam and Eleanor Mollie Horadam, and was born in 1951 in Armidale, New South Wales. She studied mathematics at Australian National University, earning a bachelor's degree in 1972 and completing her PhD in 1977. Her dissertation, The Homology of Groupnets, was supervised by Neville Smythe.
She worked for over 30 years at RMIT, becoming a professor of mathematics there in 1995. Additionally, she worked for three years in the Defence Science and Technology Group.
Book
Horadam is the author of the book Hadamard Matrices and Their Applications (Princeton University Press, 2007).
Recognition
Horadam became a fellow of the Institute of Combinatorics and its Applications in 1991 and of the Australian Mathematical Society in 2001. An international workshop on Hadamard matrices was held at RMIT in 2011 in honour of her 60th birthday, and papers from the workshop were published in 2013 as a special issue of the Australasian Journal of Combinatorics.
References
External links
1951 births
Living people
Australian mathematicians
Australian women mathematicians
Combinatorialists
Australian National University alumni
Academic staff of RMIT University | Kathy Horadam | [
"Mathematics"
] | 288 | [
"Combinatorialists",
"Combinatorics"
] |
63,288,302 | https://en.wikipedia.org/wiki/Eleanor%20Mollie%20Horadam | Eleanor Mollie Horadam (29 June 1921 – 5 May 2002) was an English-Australian mathematician specialising in the number theory of generalised integers.
Life
Horadam was born in Dewsbury, Yorkshire. She read mathematics at Girton College, Cambridge. Then, while doing wartime service by day for Rolls-Royce performing stress–strain analysis of jet engines, she took night classes in engineering at the University of London, earning first-class honours there.
She moved to Australia by herself in 1949, becoming a lecturer at the University of New England. There, she married mathematician Alwyn Horadam and raised three children, persuading the university to update their maternity policies so that (unusually for the time) she could keep her position as a lecturer. She completed a doctorate and became a senior lecturer in 1965, retired in 1983, and was named a fellow of the university in 1995.
Her daughter Kathy Horadam, also became a mathematician.
Mathematics
Horadam's research concerned generalised integers,
formed from a sequence of real numbers greater than one (called generalised prime numbers) as the products of finite multisets of generalised primes.
She was also the author of a textbook published by the University of New England, Principles of mathematics for economists (1982).
References
Further reading
1921 births
2002 deaths
British mathematicians
British women mathematicians
Australian mathematicians
Australian women mathematicians
Number theorists
Alumni of Girton College, Cambridge
Alumni of the University of London
Academic staff of the University of New England (Australia)
British emigrants to Australia | Eleanor Mollie Horadam | [
"Mathematics"
] | 311 | [
"Number theorists",
"Number theory"
] |
63,288,682 | https://en.wikipedia.org/wiki/Resatorvid | Resatorvid (TAK-242) is a cyclohexane derivative that was invented by scientists at Takeda in a drug discovery campaign to identify inhibitors of the receptor TLR4. It binds directly to cysteine residue 747 intracellularly, preventing TLR4 binding with TIRAP and thus preventing downstream signal transduction.
A randomized, double-blinded Phase III trial of resatorvid in sepsis was halted early due to lack of efficacy, and the compound has become a widely used tool compound in biological research.
It has antiinflammatory and neuroprotective effects in preclinical models. It has been explored in preclinical studies of several forms of cancer, including multiple myeloma, breast cancer, and ovarian cancer, and has been suggested for study in skin cancers.
Efforts have been made to improve resatorvid by making prodrugs and deuterated derivatives.<ref name=
See also
M62812
TLR4-IN-C34
References
Further reading
Receptor antagonists | Resatorvid | [
"Chemistry"
] | 219 | [
"Neurochemistry",
"Receptor antagonists"
] |
63,288,959 | https://en.wikipedia.org/wiki/Monobenzyl%20phthalate | Monobenzyl phthalate (MBzP) also known as 1,2-Benzenedicarboxylic acid, 1-(phenylmethyl) ester is an organic compound with the condensed structural formula C6H5CH2OOCC6H4COOH. It is the major metabolite of butyl benzyl phthalate(BBP), a common plasticizer. BBP can also be metabolized into monobutyl phthalate (MBP). Like many phthalates, BBP has attracted attention as a potential endocrine disruptor.
References
Phthalate esters
Endocrine disruptors | Monobenzyl phthalate | [
"Chemistry"
] | 141 | [
"Endocrine disruptors"
] |
63,289,994 | https://en.wikipedia.org/wiki/Glass%20Museum%20of%20Marinha%20Grande%20%28Portugal%29 | The Marinha Grande Glass Museum () is in the Marinha Grande () municipality in the Leiria District of Portugal. The museum is situated on the site of the first major glassworks in Portugal, established by the British Stephens family, and makes use of some of the original buildings, including the owners’ residence.
History
The glass industry in Marinha Grande began when an enterprise operated by John Beare, an Irishman, moved from the left bank of the river Tagus, to Leiria District in 1747 to take advantage of cheaper and better-quality raw materials there. Beare took all his workers with him. The attraction of the location was its proximity to sandy beaches and to a forest of 11,500 hectares of maritime pine trees, which had been planted in the 13th century, initially by King Afonso III and later by his son King Denis. Originally planted to act as a barrier to the invasion of farming areas by coastal sand, the pine trees proved ideal for powering glass factories. Beare experienced financial difficulties and, following the closure of the factory for two years, it was developed by an Englishman, William Stephens.
Stephens had been born in Exeter, England but made his way to Portugal at an early age, where, in 1746, he was apprenticed to a company in Lisbon operating lime kilns and, over time, had been very successful in the business. In 1769, fourteen years after the 1755 Lisbon earthquake Portugal was still desperate for glass to assist with rebuilding the country, much of which had been affected by the earthquake. This need for glass was clearly identified by the Marquis of Pombal, prime minister at the time, who played a major role in the reconstruction of Portugal after the earthquake. William Stephens had come to his attention as a competent businessman and Pombal persuaded King D. José to grant a Royal Charter to allow Stephens to re-open an existing glass factory, which became known as the Royal Glassworks (). Stephens was also given a large interest-free loan as well as permission to use the pine trees to fire the factory's kilns. He was nevertheless hesitant to take on the task, given his lack of experience with glass making, and is said to have taken two years to make up his mind to accept Pombal's offer.
Stephens was joined by his younger brother, John James, and by the end of the first year the Stephens brothers were employing 150 men in the glassworks, had manufactured 12,000 sheets of window glass and had sent over a hundred crates of glass to Lisbon. They recruited glass-making experts from both England and Genoa. In 1773, having petitioned the King to provide protection against imports from Bohemia, which, William Stephens argued, were being sold at low prices in order to drive the Marinha Grande factory out of business, they were granted a monopoly of glass supply within Portugal and its colonies. This monopoly and the tax exemptions William Stephens received as an English merchant in Lisbon enabled the brothers to become extremely rich.
The factory led to the rapid development of Marinha Grande, as many other companies were attracted to the area. It was a pioneer in the provision of social welfare by employers, providing medical care, sick benefits and pensions, as well as a school. The Stephens Brothers established a horticultural farm and a slaughterhouse, the latter to address a shortage of meat caused by the rapid increase in the number of workers at the factory. They followed the agricultural schemes of Thomas Coke of Holkham Hall and transformed agricultural productivity in the area. The factory also had its own theatre, in which the employees performed, on several occasions for visiting royalty. These enlightened ideas for the time were shared by the Marquis of Pombal and William Stephens was a member of a group advising him on social and educational reform.
On the death of William in 1802 the factory was continued by John James Stephens, who became the richest man in Lisbon, noted for his eccentricities. It was briefly taken over by the French during the Peninsular War but after the expulsion of the French the Royal Charter was renewed in May, 1810. On his death, John James bequeathed the factory to the Portuguese nation. For some time it was neglected. Its fortunes were gradually restored by the Portuguese industrialist, Manuel Joaquim Afonso, who introduced steam engines and new glass-making techniques. Then, between 1864 and 1894, another Englishman, George Croft, together with António Augusto Dias de Freitas, introduced new furnaces and technologies, with a particular emphasis on crystal production. Marinha Grande is now Portugal's biggest glass manufacturer and is known by the nickname of 'The Crystal City'.
The family fortune was inherited by Stephens Lyne-Stephens, an English Tory politician, who was reputed to be the richest commoner in England. On his death in 1860, his wife, a French ballerina, inherited the estate but there were numerous other claimants who went so far as to tamper with their family trees to bolster their claims. In the end most of the money seems to have ended up with lawyers and the British Government.
The museum
The idea for a museum was first proposed by a Government Decree in 1954, which established the Stephens Brothers School Factory. However, development of the museum did not begin until 1994, with architectural responsibility being given to José Fava. The museum opened in 1998 and presents both the history of the evolution of glass, as well technological aspects of glass production. Part of the museum is located in the former house of the Stephens, which was built within the factory perimeter. Built around 1770, the building is notable for its neoclassical style.
The Marinha Grande museum is the only museum in Portugal specifically dedicated to the study of the art and craft of the glass industry. As well, it offers a cultural programme and is considered one of the most important educational centres on the subject of glass. The collection of the museum has been developed over the years by the Portuguese Association of Industrial Archeology (APAI) (). Some of the pieces on display are on loan from other Government agencies and from the municipality of Marinha Grande. Displays show the art of glassmaking and explain the techniques used as well as displaying the most significant examples of glass art from Marinha Grande and from other Portuguese glassmaking areas, such as Vila Nova de Gaia.
The museum houses examples of glass from the 17th to the present century, which are divided into two collections. The first, situated in the former home of the Stephens Brothers, covers artistic glass as well as the technology of the production of different types of glass, such as decorative, utilitarian and scientific glass. In particular, the exhibition area reflects the evolution of the glass industry in Portugal. It shows examples of the machines and tools used in the manufacturing and decoration processes; documents from the factory; production catalogues and drawings; as well as the clothing and objects of daily use of the workers. The Contemporary Art Nucleus is located in a modern building of three floors that has been integrated into the former factory. With a collection dating from 1999, it presents about 25 years of contemporary glass art created in Portugal and elsewhere, seeking to represent the most varied artistic and design trends. The museum is a partner of the European Glass Experience.
References
Glass museums and galleries
Museums in Leiria District
Marinha Grande | Glass Museum of Marinha Grande (Portugal) | [
"Materials_science",
"Engineering"
] | 1,479 | [
"Glass engineering and science",
"Glass museums and galleries"
] |
61,125,567 | https://en.wikipedia.org/wiki/Estradiol%20hexahydrobenzoate/hydroxyprogesterone%20caproate/testosterone%20hexahydrobenzoate | Estradiol hexahydrobenzoate/hydroxyprogesterone caproate/testosterone hexahydrobenzoate (EHHB/OHPC/THHB), sold under the brand name Trinestril AP, is an injectable combination medication of estradiol hexahydrobenzoate (EHHB), an estrogen, hydroxyprogesterone caproate (OHPC), a progestogen, and testosterone hexahydrobenzoate (THHB), an androgen/anabolic steroid. It contained 3 mg EHHB, 75 mg OHPC, and 100 mg THHB and was administered by intramuscular injection once per month. The medication was marketed by 1957.
See also
List of combined sex-hormonal preparations § Estrogens, progestogens, and androgens
References
Abandoned drugs
Combined estrogen–progestogen–androgen formulations | Estradiol hexahydrobenzoate/hydroxyprogesterone caproate/testosterone hexahydrobenzoate | [
"Chemistry"
] | 206 | [
"Drug safety",
"Abandoned drugs"
] |
61,125,768 | https://en.wikipedia.org/wiki/Estrapronicate/hydroxyprogesterone%20heptanoate/nandrolone%20undecanoate | Estrapronicate/hydroxyprogesterone heptanoate/nandrolone undecanoate (EPC/OHPH/NU), tentative brand name Trophobolene or Trophoboline, is an injectable combination medication of estrapronicate (EPC; estradiol nicotinate propionate), an estrogen, hydroxyprogesterone heptanoate (OHPH), a progestogen, and nandrolone undecanoate (NU), an androgen/anabolic steroid, which was never marketed. It contained 1.3 mg EPC, 80 mg OHPH, and 50 mg NU in oil solution and was administered by intramuscular injection. The medication was developed by Théramex in the mid-to-late 1960s. It was studied for use for a variety of indications, including treatment of coronary insufficiency, growth deficiency, and osteoporosis, as well as hormonal disorders in gonadotropin deficiency.
In contrast to other anabolic steroid-containing preparations, EPC/OHPH/NU reportedly had no masculinizing effects, and its estrogenic component likewise reportedly had no feminizing effects. The nicotinic acid (niacin; vitamin B3) derived from estrapronicate was said to enhance the nutrient, relaxant, and antiadipose effects of the estrogenic component.
The pharmacokinetics of nandrolone undecanoate in this combination preparation have been studied as well as compared to nandrolone alone (Dynabolon).
See also
List of combined sex-hormonal preparations § Estrogens, progestogens, and androgens
References
Abandoned drugs
Combined estrogen–progestogen–androgen formulations | Estrapronicate/hydroxyprogesterone heptanoate/nandrolone undecanoate | [
"Chemistry"
] | 388 | [
"Drug safety",
"Abandoned drugs"
] |
61,126,242 | https://en.wikipedia.org/wiki/Confusional%20arousal | A confusional arousal (also known as sleep drunkenness or severe sleep inertia) is medical condition where a person awakened from sleep shows mental confusion for at least several minutes. Complete or partial amnesia of the episodes may be present.
Signs and symptoms
Confusional arousals are accompanied by mental confusion and disorientation, relative lack of response to environmental stimuli, and difficulty of awakening the subject. Vocalisation accompanied with coherent speech is common. Patients may appear upset, and some of them become aggressive or agitated. As well as for children, attempting to awaken or console an adult patient may increase agitation. Confusional arousals can occur during or following an arousal of deep sleep (see slow-wave sleep) and upon an attempt of awakening the subject from sleep in the morning.
In children, confusional arousals can often be reproduced artificially by awakening the child during deep sleep. However, it doesn't have any clinical significance without deeper investigation. Children living an episode of confusional arousal typically sit up in bed, whimper, cry, moan, and may utter words like “no” or “go away”. They remain distressed and inconsolable despite all parental efforts. Paradoxically, parental efforts can rather increase agitation of the child. The onset of symptoms is usually within 2 and 3 hours of sleep onset (at the time of transition from slow-wave sleep to a lighter sleep stage) and those events can last from 10 to 30 minutes. Patients generally wake up without any recollection of the event. It is necessary to distinguish confusional arousals in adults from children.
Neurological symptomatology
Confusional arousals are associated with behavioural awakening with persistent slow-wave electroencephalographic activity (see slow-wave sleep) during Non-rapid eye movement sleep (NREM). It suggests that sensorimotor network is activated while non sensorimotor areas are still "asleep". The altered state of consciousness may be explained by a hypersynchronous delta activity (see delta wave) in network involving the frontoparietal cortices (suggesting to be "asleep"), and higher frequency activities in sensorimotor, orbitofrontal, and temporal lateral cortices (suggesting an "awakening").
Sleep-related violence and abnormal sexual behaviours
Confusional arousals have often been linked to sleep-related violence (self-injury or injury to the bed partner). The latter highlights important medical and legal issues when such behaviours are suspected and purported to have caused a criminal offense. The first documented case of homicide as a result of confusional arousal was reported in medieval times by the case of the Silesian woodcutter Bernard Schedmaizig. Sleep-related abnormal sexual behaviours (also called sexsomnia or sleep sex) are mainly classified as confusional arousals and more rarely associated to sleepwalking (also known as somnambulism). Even if sleep-related violence may occur during an episode of confusional arousal, it remains extremely rare and there is no specific predisposition to aggression during these episodes.
Distinction between sleepwalking and night terrors
Violent behaviours in confusional arousals slightly differ from those in sleepwalking or night terrors. Above all, during an episode of confusional arousal the patient never leaves the bed, unlike sleepwalking. A bed partner or parent who tries to calm or restrain the patient by grabbing him or her may trigger a violent reaction as with sleepwalkers. In case of a confusional arousal triggered by an attempt of awakening the patient, violent behaviours may occur almost spontaneously. Unlike confusional arousals and sleep walking, patients experiencing night terrors seem to react to some type of frightening image. Therefore, the violent reaction may occur if another individual is encountered or is in proximity.
Classification
International Classification of Sleep Disorders (ICSD)
According to the 2nd edition of the International Classification of Sleep Disorders (ICSD-2), confusional arousals are classified in NREM parasomnias embedded in the non-epileptic paroxysmal motor events during sleep, which include (1) Parasomnia, (2) Sleep-related movement disorders and (3) Isolated symptoms, apparently normal variants and unresolved issues. NREM parasomnias (or disorders of arousal) also include sleep terrors (see night terror) and sleepwalking. Confusional arousals are characterised by more or less complex movements without leaving bed with whimpering, sitting up in bed and some articulation without walking or terror. In comparison, of other arousal parasomnias the age onset of sleep walking is generally between 5 and 10 years whereas confusional arousals and sleep terror may occur 3 years earlier. Sleep terrors are mainly characterised by screaming, agitation, flushed face, sweating and only share the inconsolability with confusional arousals. The current 3rd edition of the International Classification of Sleep Disorders (ICSD-3) added the sleep-related eating disorders in the disorders of arousal from NREM sleep.
Diagnostic and Statistical Manual of Mental Disorders (DSM)
Confusional arousals are at the time not considered as a disorder in the current 5th edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-V). This absence may be explained by the fact that confusional arousals have been understudied by the scientific community.
Diagnosis
The evaluation "should include a comprehensive medical history, a physical, neurological, and developmental examination, and a detailed description of the nocturnal events, sleep-wake schedules, and daytime behaviour”. However, the episodes have a long duration and a low rate of same-night recurrence. Even if amnesia usually follows episodes of confusional arousal, it is not a distinct trait related to severity.
A video-polysomnography (see polysomnography) might be required if life history is untypical. In case of suspicion parents are encouraged to use infrared camera to record the behaviour of their child during sleep. Association of video recordings of nocturnal episodes with historical features is an important tool for both understanding and correctly diagnosing the disorder differently from other episodes of parasomnia. Confusional arousals as well as arousal parasomnias in general must be distinguished from epileptic seizure on the basis of clinical and electroencephalographic features (see electroencephalography).
Management
Children mostly outgrow the condition by late adolescence if not sooner. Management includes mainly non-pharmacological treatments and daily behaviours guidelines, but may include safety measures and/or medications if the patient is in danger from his or her behaviour:
Ensure regular and adequate sleep routines in order to prevent sleep-wake cycle to be disrupted.
Use of safety measures for the patient and family by clearing the bedroom from obstacles, securing the windows, or installing locks or alarms.
Medications are necessary if the patient is in danger from his or her behaviour. In this case, Imipramine or low-dose Clonazepam is beneficial.
Epidemiology
The current prevalence of confusional arousals varies according to the year and the sample population and is approximately 4% (4.2% in 1999 in UK sample population, 6.1% (15–24 years old), 3.3% (25–34 y.o.) and 2% (35+ y.o.) in 2000 in UK, Germany and Italy sample population, 6.9% in 2010 in Norway sample population with a lifetime prevalence of 18.5%). The current prevalence of confusional arousals in children (3–13 y.o.) is higher and around 17.3%. Confusional arousals without a known cause or associated condition is uncommon (for about 1% of cases ).The contribution of genetics and family link is strong and episodes of confusional arousals can occur in several members of the same family.
Risk factors
Some independent risk factors associated with confusional arousals have been identified. According to studies, they are shift work, hypnagogic hallucinations (also known as hypnagogia), excessive daytime sleepiness, insomnia and hypersomnia disorder, circadian rhythm sleep disorder, restless legs syndrome, obstructive sleep apnea syndrome (OSAS), bipolar disorder, daily smoking, and age of 15–24 years. These risk factors of confusional arousals are somehow related to mental disorders and medical conditions and affecting mostly younger subjects regardless of gender. Precipitating factors include sleep deprivation, use of hypnotics or tranquilisers before bedtime, and sudden awakening from sleep (e.g., telephone ringing, alarm clock).
In the ICSD-2 alcohol intake had been considered as a precipitating factor of confusional arousals. In the ICSD-3 the relation between alcohol use and disorder or arousal have been excluded. Moreover, the alcohol blackout has been added as a differential diagnosis. These changes have important implications for forensic cases.
References
Parasomnias
Sleep disorders | Confusional arousal | [
"Biology"
] | 1,842 | [
"Behavior",
"Sleep",
"Sleep disorders"
] |
61,126,875 | https://en.wikipedia.org/wiki/Barbara%20M.%20Middlehurst | Barbara Mary Middlehurst (September 15, 1915 – March 6, 1995) was a Welsh astronomer.
Early life
Barbara Mary Middlehurst was born in Penarth, Glamorgan, Wales. She attended Penarth County School for Girls and Girton College, Cambridge, where she studied mathematics. She earned a bachelor's degree in 1936 and a master's degree in 1947. She built her astronomy credentials over several years of independent reading and practice.
Career
Middlehurst taught mathematics at Penarth as a young woman. During World War II she drove an ambulance in her hometown. In 1951, Middlehurst joined the staff of the observatory at the University of St. Andrews in Scotland. She moved to the United States in 1959, to join the staff at Yerkes Observatory in Wisconsin. She also worked at the Steward Observatory in Tucson, Arizona, and at the Lunar and Planetary Institute in Houston, Texas. Her research focused on Transient Lunar Phenomena (TLPs). She co-compiled a 1968 catalog of TLPs for NASA, with Jaylee Burley Mead, Patrick Moore, and Barbara Welther.
She was co-editor with Gerard Kuiper of Telescopes (1960), The Solar System III: Planets and Satellites (1961), and The Solar System IV: The Moon, Meteorites and Comets (1963). She was associate general editor of a nine-volume series, Stars and Stellar Systems (1968), again working with Kuiper, and co-edited the volume Nebulae and Interstellar Matter (with Lawrence H. Aller). She was astronomy editor for Encyclopedia Britannica.
She was active in the American Astronomical Society and in the International Astronomical Union, and served as secretary of the IAU's Commission on the Moon in 1970. She was elected a fellow of the American Geophysical Union in 1972; she was also a fellow of the Royal Astronomical Society, elected in 1949.
Personal life
Middlehurst retired to Clear Lake City, Houston, where she died in 1995, aged 79 years, after a stroke. In 2009, Astro-Cymru, a Welsh Heritage Lottery project, included Middlehurst on a short list of notable Welsh astronomers for school projects, programs, and exhibits, to "celebrate 400 years of Welsh astronomy".
References
1915 births
1995 deaths
Welsh astronomers
Women astronomers
People from Penarth
Alumni of Girton College, Cambridge | Barbara M. Middlehurst | [
"Astronomy"
] | 478 | [
"Women astronomers",
"Astronomers"
] |
61,126,980 | https://en.wikipedia.org/wiki/C28H42O3 | {{DISPLAYTITLE:C28H42O3}}
The molecular formula C28H42O3 (molar mass: 426.641 g/mol, exact mass: 426.3134 u) may refer to:
Estradiol decanoate (E2D)
Testosterone cyclohexylpropionate | C28H42O3 | [
"Chemistry"
] | 74 | [
"Isomerism",
"Set index articles on molecular formulas"
] |
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