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65,937,796 | https://en.wikipedia.org/wiki/Illustrative%20model%20of%20greenhouse%20effect%20on%20climate%20change | There is a strong scientific consensus that greenhouse effect due to carbon dioxide is a main driver of climate change. Following is an illustrative model meant for a pedagogical purpose, showing the main physical determinants of the effect.
Under this understanding, global warming is determined by a simple energy budget: In the long run, Earth emits radiation in the same amount as it receives from the sun. However, the amount emitted depends both on Earth's temperature and on its albedo: The more reflective the Earth in a certain wavelength, the less radiation it would both receive and emit in this wavelength; the warmer the Earth, the more radiation it emits. Thus changes in the albedo may have an effect on Earth's temperature, and the effect can be calculated by assuming a new steady state would be arrived at.
In most of the electromagnetic spectrum, atmospheric carbon dioxide either blocks the radiation emitted from the ground almost completely, or is almost transparent, so that increasing the amount of carbon dioxide in the atmosphere, e.g. doubling the amount, will have negligible effects. However, in some narrow parts of the spectrum this is not so; doubling the amount of atmospheric carbon dioxide will make Earth's atmosphere relatively opaque to in these wavelengths, which would result in Earth emitting light in these wavelengths from the upper layers of the atmosphere, rather from lower layers or from the ground. Since the upper layers are colder, the amount emitted would be lower, leading to warming of Earth until the reduction in emission is compensated by the rise in temperature.
Furthermore, such warming may cause a feedback mechanism due to other changes in Earth's albedo, e.g. due to ice melting.
Structure of the atmosphere
Most of the air—including ~88% of the CO2—is located in the lower part of the atmosphere known as troposphere. The troposphere is thicker in the equator and thinner at the poles, but the global mean of its thickness is around 11 km.
Inside the troposphere, the temperature drops approximately linearly at a rate of 6.5 Celsius degrees per km, from a global mean of 288 Kelvin (15 Celsius) on the ground to 220 K (-53 Celsius). At higher altitudes, up to 20 km, the temperature is approximately constant; this layer is called the tropopause.
The troposphere and tropopause together consist of ~99% of the atmospheric CO2. Inside the troposphere, the CO2 drops with altitude approximately exponentially, with a typical length of 6.3 km; this means that the density at height y is approximately proportional to exp(-y/6.3 km), and it goes down to 37% at 6.3 km, and to 17% at 11 km. Higher through the tropopause, density continues dropping exponentially, albeit faster, with a typical length of 4.2 km.
Effect of carbon dioxide on the Earth's energy budget
Earth constantly absorbs energy from sunlight and emits thermal radiation as infrared light.
In the long run, Earth radiates the same amount of energy per second as it absorbs, because the amount of thermal radiation emitted depends upon temperature: If Earth absorbs more energy per second than it radiates, Earth heats up and the thermal radiation will increase, until balance is restored; if Earth absorbs less energy than it radiates, it cools down and the thermal radiation will decrease, again until balance is restored.
Atmospheric CO2 absorbs some of the energy radiated by the ground, but it emits itself thermal radiation: For example, in some wavelengths the atmosphere is totally opaque due to absorption by CO2; at these wavelengths, looking at Earth from outer space one would not see the ground, but the atmospheric CO2, and hence its thermal radiation—rather than the ground's thermal radiation. Had the atmosphere been at the same temperature as the ground, this would not change Earth's energy budget; but since the radiation is emitted from atmosphere layers that are cooler than the ground, less radiation is emitted.
As CO2 content of the atmosphere increases due to human activity, this process intensifies, and the total radiation emitted by Earth diminishes; therefore, Earth heats up until the balance is restored.
Radiation absorption by carbon dioxide
CO2 absorbs the ground's thermal radiation mainly at wavelengths between 13 and 17 micron. At this wavelength range, it is almost solely responsible for the attenuation of radiation from the ground. The amount of ground radiation that is transmitted through the atmosphere in each wavelength is related to the optical depth of the atmosphere at this wavelength, OD, by:
The optical depth itself is given by Beer–Lambert law:
where σ is the absorption cross section of a single CO2 molecule, and n(y) is the
number density of these molecules at altitude y. Due to the high dependence of the cross section in wavelength, the OD changes from around 0.1 at 13 microns to ~10 at 14 microns and even higher beyond 100 at 15 microns, then dropping off to ~10 at 16 microns, ~1 at 17 microns and below 0.1 at 18 microns. Note that the OD depends on the total number of molecules per unit area in the atmosphere, and therefore rises linearly with its CO2 content.
Looked upon from outer space into the atmosphere at a specific wavelength, one would see to different degrees different layers of the atmosphere, but on average one would see down to an altitude such that the part of the atmosphere from this altitude and up has an optical depth of ~1. Earth will therefore radiate at this wavelength approximately according to the temperature of that altitude. The effect of increasing CO2 atmospheric content means that the optical depth increases, so that the altitude seen from outer space increases; as long as it increases within the troposphere, the radiation temperature drops and the radiation decreases. When it reaches the tropopause, any further increase in CO2 levels will have no noticeable effect, since the temperature no longer depends there on the altitude.
At wavelengths of 14 to 16 microns, even the tropopause, having ~0.12 of the amount of CO2 of the whole atmosphere, has OD>1. Therefore, at these wavelengths Earth radiates mainly in the tropopause temperature, and addition of CO2 does not change this. At wavelengths smaller than 13 microns or larger than 18 microns, the atmospheric absorption is negligible, and addition of CO2 hardly changes this. Therefore, the effect of CO2 increase on radiation is relevant in wavelengths 13–14 and 16–18 microns, and addition on CO2 mainly contributes to the opacity of the troposphere, changing the altitude that is effectively seen from outer space within the troposphere.
Calculating the effect on radiation
One layer model
We now turn to calculating the effect of CO2 on radiation, using a one-layer model, i.e. we treat the whole troposphere as a single layer:
Looking at a particular wavelength λ up to λ+dλ, the whole atmosphere has an optical depth OD, while the tropopause has an optical depth 0.12*OD; the troposphere has an optical depth of 0.88*OD.
Thus,
of the radiation from below the tropopause is transmitted out, but this includes of the radiation that originates from the ground.
Thus, the weight of the troposphere in determining the radiation that is emitted to outer space is:
A relative increase in the CO2 concentration means an equal relative increase in the total CO2 content of the atmosphere, dN/N where N is the number of CO2 molecules.
Adding a minute number of such molecules dN will increase the troposphere's weight in determining the radiation for the relevant wavelengths, approximately by the relative amount dN/N, and thus by:
Since CO2 hardly influences sunlight absorption by Earth, the radiative forcing due to an increase in CO2 content is equal to the difference in the flux radiated by Earth due to such an increase. To calculate this, one must multiply the above by the difference in radiation due to the difference in temperature. According to Planck's law, this is:
The ground is at temperature T0 = 288 K, and for the troposphere we will take a typical temperature, the one at the average height of molecules, 6.3 km, where the temperature is T1247 K.
Therefore, dI, the change in Earth's emitted radiation is, in a rough approximation, is:
Since dN/N = d(ln N), this can be written as:
The function is maximal for x = 2.41, with a maximal value of 0.66, and it drops to half this value at x=0.5 and x = 9.2. Thus we look at wavelengths for which the OD is between 0.5 and 9.2: This gives a wavelength band at the width of approximately 1 micron around 17 microns, and less than 1 micron around 13.5 microns. We therefore take:
λ = 13.5 microns and again 17 microns (summing contributions from both)
dλ = 0.5 micron for the 13.5 microns band, and 1 micron for the 17 microns band.
Which gives -2.3 W/m2 for the 13.5 microns band, and -2.7 W/m2 for the 17 microns band, for a total of 5 W/m2.
A 2-fold increase in CO2 content changes the wavelengths ranges only slightly, and so this derivative is approximately constant along such an increase. Thus, a 2-fold increase in CO2 content will reduce the radiation emitted by Earth by approximately:
ln(2)*5 W/m2 = 3.4 W/m2.
More generally, an increase by a factor c/c0 gives:
ln(c/c0)*5 W/m2
These results are close to the approximation of a more elaborate yet simplified model giving
ln(c/c0)*5.35 W/m2, and the radiative forcing due to CO2 doubling with much more complicated models giving 3.1 W/m2.
Emission Layer Displacement Model
We may make a more elaborate calculation by treating the atmosphere as compounded of many thin layers. For each such layer, at height y and thickness dy, the weight of this layer in determining the radiation temperature seen from outer space is a generalization of the expression arrived at earlier for the troposphere. It is:
where OD(y) is the optical depth of the part of the atmosphere from y upwards.
The total effect of CO2 on the radiation at wavelengths λ to λ+dλ is therefore:
where B is the expression for radiation according to Planck's law presented above:
and the infinity here can be taken actually as the top of the tropopause.
Thus the effect of a relative change in CO2 concentration, dN/N = dn0/n0 (where n0 is the density number near ground), would be (noting that dN/N = d(ln N) = d(ln n0):
where we have used integration by part.
Because B does not depend on N, and because , we have:
Now, is constant in the troposphere and zero in the tropopause. We denote the height of the border between them as U. So:
The optical depth is proportional to the integral of the number density over y, as does the pressure. Therefore, OD(y) is proportional to the pressure p(y), which within the troposphere (height 0 to U) falls exponentially with decay constant 1/Hp (Hp~5.6 km for CO2), thus:
Since + constant, viewed as a function of both y and N, we have:
And therefore differentiating with respect to ln N is the same as differentiating with respect to y, times a factor of .
We arrive at:
.
Since the temperature only changes by ~25% within the troposphere, one may take a (rough) linear approximation of B with T at the relevant wavelengths, and get:
Due to the linear approximation of B we have:
with T1 taken at Hp, so that totally:
giving the same result as in the one-layer model presented above, as well as the logarithmic dependence on N, except that now we see T1 is taken at 5.6 km (the pressure drop height scale), rather than 6.3 km (the density drop height scale).
Comparison to the total radiation emitted by Earth
The total average energy per unit time radiated by Earth is equal to the average energy flux j times the surface area 4πR2, where R is Earth's radius. On the other hand, the average energy flux absorbed from sunlight is the solar constant S0 times Earth's cross section of πR2, times the fraction absorbed by Earth, which is one minus Earth's albedo a.
The average energy per unit time radiated out is equal to the average energy per unit time absorbed from sunlight, so:
giving:
Based on the value of 3.1 W/m^2 obtained above in the section on the one layer model, the radiative forcing due to CO2 relative to the average radiated flux is therefore:
An exact calculation using the MODTRAN model, over all wavelengths and including methane and ozone greenhouse gasses, as shown in the plot above, gives, for tropical latitudes, an outgoing flux 298.645 W/m2 for current CO2 levels and 295.286 W/m2 after CO2 doubling, i.e. a radiative forcing of 1.1%, under clear sky conditions, as well as a ground temperature of 299.7o K (26.6o Celsius). The radiative forcing is largely similar in different latitudes and under different weather conditions.
Effect on global warming
On average, the total power of the thermal radiation emitted by Earth is equal to the power absorbed from sunlight. As CO2 levels rise, the emitted radiation can maintain this equilibrium only if the temperature increases, so that the total emitted radiation is unchanged (averaged over enough time, in the order of few years so that diurnal and annual periods are averaged upon).
According to Stefan–Boltzmann law, the total emitted power by Earth per unit area is:
where σB is Stefan–Boltzmann constant and ε is the emissivity in the relevant wavelengths. T is some average temperature representing the effective radiation temperature.
CO2 content changes the effective T, but instead one may treat T to be a typical ground or lower-atmosphere temperature (same as T0 or close to it) and consider CO2 content as changing the emissivity ε. We thus re-interpret ε in the above equation as an effective emissivity that includes the CO2 effect;, and take T=T0. A change in CO2 content thus causes a change dε in this effective emissivity, so that is the radiative forcing, divided by the total energy flux radiated by Earth.
The relative change in the total radiated energy flux due to changes in emissivity and temperature is:
Thus, if the total emitted power is to remain unchanged, a radiative forcing relative to the total energy flux radiated by Earth, causes a 1/4-fold relative change in temperature.
Thus:
Ice–albedo feedback
Since warming of Earth means less ice on the ground on average, it would cause lower albedo and more sunlight absorbed, hence further increasing Earth's temperature.
As a rough estimate, we note that the average temperature on most of Earth are between -20 and +30 Celsius degree, a good guess will be that 2% of its surface are between -1 and 0 °C, and thus an equivalent area of its surface will be changed from ice-covered (or snow-covered) to either ocean or forest.
For comparison, in the northern hemisphere, the arctic sea ice has shrunk between 1979 and 2015 by 1.43x1012 m2 at maxima and 2.52x1012 m2 at minima, for an average of almost 2x1012 m2, which is 0.4% of Earth's total surface of 510x1012 m2. At this time the global temperature rose by ~0.6 °C. The areas of inland glaciers combined (not including the antarctice ice sheet), the antarctic sea ice, and the arctic sea ice are all comparable, so one may expect the change in ice of the arctic sea ice is roughly a third of the total change, giving 1.2% of the Earth surface turned from ice to ocean or bare ground per 0.6 °C, or equivalently 2% per 1 °C. The antarctic ice cap size oscillates, and it is hard to predict its future course, with factors such as relative thermal insulated and constraints due to the Antarctic Circumpolar Current probably playing a part.
As the difference in albedo between ice and e.g. ocean is around 2/3, this means that due to a 1 °C rise, the albedo will drop by 2%*2/3 = 4/3%. However this will mainly happen in northern and southern latitudes, around 60 degrees off the equator, and so the effective area is actually 2% * cos(60o) = 1%, and the global albedo drop would be 2/3%.
Since a change in radiation of 1.3% causes a direct change of 1 degree Celsius (without feedback), as calculated above, and this causes another change of 2/3% in radiation due to positive feedback, whice is half the original change, this means the total factor caused by this feedback mechanism would be:
Thus, this feedback would double the effect of the change in radiation, causing a change of ~ 2 K in the global temperature, which is indeed the commonly accepted short-term value. For long-term value, including further feedback mechanisms, ~3K is considered more probable.
References
Climatology
Greenhouse gases
Carbon dioxide | Illustrative model of greenhouse effect on climate change | [
"Chemistry",
"Environmental_science"
] | 3,769 | [
"Greenhouse gases",
"Carbon dioxide",
"Environmental chemistry"
] |
65,939,210 | https://en.wikipedia.org/wiki/Xiaoyi%20%28robot%29 | Xiaoyi is a Chinese AI-powered robotic medical doctor developed by the iFlyTek, an AI company headquartered in China. The robot is developed to function as an assistant to human doctors to improve efficiency in the future treatments as in competition to IBM's Watson, Amazon's Echo and Google's DeepMind Health. Xiaoyi is known to be the first robot in the world which makes history by passing the China's National Medical Licensing Examination, the first assessment of its kind for any would-be doctor practicing in the country.
Overview
Chinese robot's name ‘Xiaoyi’ that means "Little Doctor" became the first AI robot to pass the Medical Licensing Exam, developed by iFlyTek in collaboration with Tsinghua University.
As per the Beijing News, it is clearly stated that before in the practice round, Xiaoyi hardly attained 100 out of 600 points in China's medical licensing exam which was quite unsatisfactory for the developers as the passing were 360 points. Xiaoyi prepared again, thus by thoroughly going through the dozens of medical textbooks’ materials, two million medical records and furthermore reviewed 400,000 articles in order to develop the kind of a reasoning ability needed to become a doctor. The robot took a fraction of allotted time required to complete the test when attempted real test, passing with a score of 456 which was 96 points higher than the passing marks afterwards.
Xiaoyi's development is a part of great efforts by China in accelerating the AI application in consumer electronics, healthcare and many other industries. An artificial intelligence-enabled robot can automatically capture and analyze the patient's information and can make initial diagnostics. Liu Qingfeng, chairman of iFlytek, said, "We will officially launch the robot in March 2018. It is not meant to replace doctors. Instead, it is to promote better people-machine cooperation so as to boost efficiency."
References
External links
Official website
Medical robots
Robots of China
Bipedal humanoid robots
2000 robots | Xiaoyi (robot) | [
"Biology"
] | 399 | [
"Biotechnology stubs",
"Medical technology stubs",
"Medical technology"
] |
65,939,595 | https://en.wikipedia.org/wiki/Maria%20Domenica%20Di%20Benedetto | Maria Domenica Di Benedetto (born 1953) is an Italian electrical engineer and control theorist whose interests include the control of hybrid systems, embedded control systems, automotive engine control, and aerospace flight control. She is Professor of Automatic Control at the University of L'Aquila, president of the European Embedded Control Institute, and the former president of the Italian Society of researchers in Automatic Control.
She should be distinguished from Maria-Gabriella Di Benedetto, another Italian electrical engineer with similar career details.
Education and career
Di Benedetto earned a master's degree (Dr. Ing.) at Sapienza University of Rome in 1976. She earned a French doctorate of engineering at Paris-Sud University in 1981 and a state doctorate there in 1987.
She worked as a research engineer for IBM in Paris and Rome from 1979 to 1983, as an assistant professor at Sapienza University from 1983 to 1987, as an associate professor at the Parthenope University of Naples (then called the Istituto Universitario Navale) from 1987 to 1990, and again at Sapienza University from 1990 to 1993. She joined the Department of Information Engineering at the University of L'Aquila as Professor of Automatic Control in 1994. At L'Aquila, she directs the Center of Excellence for Research in Design methodologies of Embedded controllers, Wireless interconnect and Systems-on-chip (DEWS).
She has headed the European Embedded Control Institute (EECI) since 2009, and served as president of the Italian Society of researchers in Automatic Control (SIDRA) from 2013 to 2019.
Book
With Elena De Santis, Di Benedetto is the coauthor of the book Observability of Hybrid Dynamical Systems (Now Publishers, 2016).
Recognition
Di Benedetto was named an IEEE Fellow in the class of 2002, affiliated with the IEEE Control Systems Society, "for contributions to the theory of nonlinear and hybrid control system design". She was named a Fellow of the International Federation of Automatic Control in 2019, "for contributions to nonlinear and hybrid system theory and leadership in control research and education".
References
External links
DEWS
1953 births
Living people
Italian electrical engineers
Italian women engineers
Control theorists
Sapienza University of Rome alumni
Academic staff of the Sapienza University of Rome
Academic staff of the Parthenope University of Naples
Fellows of the IEEE
Fellows of the International Federation of Automatic Control | Maria Domenica Di Benedetto | [
"Engineering"
] | 492 | [
"Control engineering",
"Control theorists"
] |
65,940,597 | https://en.wikipedia.org/wiki/Comparison%20of%20user%20features%20of%20messaging%20platforms | Comparison of user features of messaging platforms refers to a comparison of all the various user features of various electronic instant messaging platforms. This includes a wide variety of resources; it includes standalone apps, platforms within websites, computer software, and various internal functions available on specific devices, such as iMessage for iPhones.
This entry includes only the features and functions that shape the user experience for such apps. A comparison of the underlying system components, programming aspects, and other internal technical information, is outside the scope of this entry.
Overview and background
Instant messaging technology is a type of online chat that offers real-time text transmission over the Internet. A LAN messenger operates in a similar way over a local area network. Short messages are typically transmitted between two parties when each user chooses to complete a thought and select "send". Some IM applications can use push technology to provide real-time text, which transmits messages character by character, as they are composed. More advanced instant messaging can add file transfer, clickable hyperlinks, Voice over IP, or video chat.
Non-IM types of chat include multicast transmission, usually referred to as "chat rooms", where participants might be anonymous or might be previously known to each other (for example collaborators on a project that is using chat to facilitate communication). Instant messaging systems tend to facilitate connections between specified known users (often using a contact list also known as a "buddy list" or "friend list"). Depending on the IM protocol, the technical architecture can be peer-to-peer (direct point-to-point transmission) or client-server (an Instant message service center retransmits messages from the sender to the communication device).
By 2010, instant messaging over the Web was in sharp decline, in favor of messaging features on social networks. The most popular IM platforms were terminated, such as AIM which closed down and Windows Live Messenger which merged into Skype. Instant messaging has since seen a revival in popularity in the form of "messaging apps" (usually on mobile devices) which by 2014 had more users than social networks.
As of 2010, social networking providers often offer IM abilities. Facebook Chat is a form of instant messaging, and Twitter can be thought of as a Web 2.0 instant messaging system. Similar server-side chat features are part of most dating websites, such as OkCupid or PlentyofFish. The spread of smartphones and similar devices in the late 2000s also caused increased competition with conventional instant messaging, by making text messaging services still more ubiquitous.
Many instant messaging services offer video calling features, voice over IP and web conferencing services. Web conferencing services can integrate both video calling and instant messaging abilities. Some instant messaging companies are also offering desktop sharing, IP radio, and IPTV to the voice and video features.
The term "Instant Messenger" is a service mark of Time Warner and may not be used in software not affiliated with AOL in the United States. For this reason, in April 2007, the instant messaging client formerly named Gaim (or gaim) announced that they would be renamed "Pidgin".
In the 2010s, more people started to use messaging apps on modern computers and devices like WhatsApp, WeChat, Viber, Facebook Messenger, Telegram, Signal and Line rather than instant messaging on computers like AIM and Windows Live Messenger. For example, WhatsApp was founded in 2009, and Facebook acquired in 2014, by which time it already had half a billion users.
Concepts
Backchannel
Backchannel is the practice of using networked computers to maintain a real-time online conversation alongside the primary group activity or live spoken remarks. The term was coined in the field of linguistics to describe listeners' behaviours during verbal communication. (See Backchannel (linguistics).)
The term "backchannel" generally refers to online conversation about the conference topic or speaker. Occasionally backchannel provides audience members a chance to fact-check the presentation.
First growing in popularity at technology conferences, backchannel is increasingly a factor in education where WiFi connections and laptop computers allow participants to use ordinary chat like IRC or AIM to actively communicate during presentation. More recent research include works where the backchannel is brought publicly visible, such as the ClassCommons, backchan.nl and Fragmented Social Mirror.
Twitter is also widely used today by audiences to create backchannels during broadcasting of content or at conferences. For example, television drama, other forms of entertainment and magazine programs. This practice is often also called live tweeting. Many conferences nowadays also have a hashtag that can be used by the participants to share notes and experiences; furthermore such hashtags can be user generated.
Features
Various platforms and apps are distinguished by their strengths and features in regards to specific functions.
Group messaging
Official channels
Some apps include a feature known as "official channels" which allows companies, especially news media outlets, publications, and other mass media companies, to offer an official channel, which users can join, and thereby receive regular updates, published articles, or news updates from companies or news outlets. Two apps which have a large amount of such channels available are Line and Telegram.
Video group calls
Basic default platforms
Basic platforms which are common across entire categories of mobile devices, computers, or operating systems.
SMS
SMS (short message service) is a text messaging service component of most telephone, Internet, and mobile device systems. It uses standardized communication protocols to enable mobile devices to exchange short text messages. An intermediary service can facilitate a text-to-voice conversion to be sent to landlines.
SMS, as used on modern devices, originated from radio telegraphy in radio memo pagers that used standardized phone protocols. These were defined in 1985 as part of the Global System for Mobile Communications (GSM) series of standards. The first test SMS message was sent on December 3, 1992, when Neil Papwort, a test engineer for Sema Group, used a personal computer to send "Merry Christmas" to the phone of colleague Richard Jarvis. It commercially rolled out to many cellular networks that decade. SMS became hugely popular worldwide as a way of text communication. By the end of 2010, SMS was the most widely used data application, with an estimated 3.5 billion active users, or about 80% of all mobile phone subscribers.
The protocols allowed users to send and receive messages of up to 160 characters (when entirely alpha-numeric) to and from GSM mobiles. Although most SMS messages are sent from one mobile phone to another, support for the service has expanded to include other mobile technologies, such as ANSI CDMA networks and Digital AMPS.
Mobile marketing, a type of direct marketing, uses SMS. According to a 2018 market research report the global SMS messaging business was estimated to be worth over US$100 billion, accounting for almost 50 percent of all the revenue generated by mobile messaging.
A Flash SMS is a type of SMS that appears directly on the main screen without user interaction and is not automatically stored in the inbox. It can be useful in emergencies, such as a fire alarm or cases of confidentiality, as in delivering one-time passwords.
Threaded SMS format
Threaded SMS is a visual styling orientation of SMS message history that arranges messages to and from a contact in chronological order on a single screen.
It was first invented by a developer working to implement the SMS client for the BlackBerry, who was looking to make use of the blank screen left below the message on a device with a larger screen capable of displaying far more than the usual 160 characters, and was inspired by threaded Reply conversations in email.
Visually, this style of representation provides a back-and-forth chat-like history for each individual contact. Hierarchical-threading at the conversation-level (as typical in blogs and on-line messaging boards) is not widely supported by SMS messaging clients. This limitation is due to the fact that there is no session identifier or subject-line passed back and forth between sent and received messages in the header data (as specified by SMS protocol) from which the client device can properly thread an incoming message to a specific dialogue, or even to a specific message within a dialogue.
Most smart phone text-messaging-clients are able to create some contextual threading of "group messages" which narrows the context of the thread around the common interests shared by group members. On the other hand, advanced enterprise messaging applications that push messages from a remote server often display a dynamically changing reply number (multiple numbers used by the same sender), which is used along with the sender's phone number to create session-tracking capabilities analogous to the functionality that cookies provide for web-browsing. As one pervasive example, this technique is used to extend the functionality of many Instant Messenger (IM) applications such that they are able to communicate over two-way dialogues with the much larger SMS user-base. In cases where multiple reply numbers are used by the enterprise server to maintain the dialogue, the visual conversation threading on the client may be separated into multiple threads.
Multimedia Messaging Service
Multimedia Messaging Service (MMS) is a standard way to send messages that include multimedia content to and from a mobile phone over a cellular network. Users and providers may refer to such a message as a PXT, a picture message, or a multimedia message. The MMS standard extends the core SMS (Short Message Service) capability, allowing the exchange of text messages greater than 160 characters in length. Unlike text-only SMS, MMS can deliver a variety of media, including up to forty seconds of video, one image, a slideshow of multiple images, or audio.
The first MMS-capable phones were introduced around 2002 in conjunction with the first GSM network. The Sony Ericsson T68i is widely believed to be the first MMS-capable cell phone, while many more hit North American markets beginning in 2004 and 2005.
The most common use involves sending photographs from camera-equipped handsets. Media companies have utilized MMS on a commercial basis as a method of delivering news and entertainment content, and retailers have deployed it as a tool for delivering scannable coupon codes, product images, videos, and other information.
The 3GPP and WAP groups fostered the development of the MMS standard, which is now continued by the Open Mobile Alliance (OMA).
Content adaptation: Multimedia content created by one brand of MMS phone may not be entirely compatible with the capabilities of the recipient's MMS phone. In the MMS architecture, the recipient MMSC is responsible for providing for content adaptation (e.g., image resizing, audio codec transcoding, etc.), if this feature is enabled by the mobile network operator. When content adaptation is supported by a network operator, its MMS subscribers enjoy compatibility with a larger network of MMS users than would otherwise be available.
Rich Communication Services
Rich Communication Services (RCS) is a communication protocol standard between mobile telephone carriers, based on IP Multimedia Subsystem, developed and defined by the GSM Association (GSMA). It aims to be a replacement of SMS and MMS, with a text-message system that is richer and provides phonebook polling (for service discovery). It is also marketed as Advanced Messaging, and was previously marketed as chat features, joyn, SMSoIP, Message+, and SMS+.
RCS features include high-resolution photo and video sharing, file sharing, typing indicators, read receipts, operation over mobile data or Wi-Fi, and improved group chat functionality. End-to-end encryption is not a feature of RCS specified by GSMA, instead deferring to the individual messaging clients to establish encryption; Google has added support for this feature using RCS in their own text messaging app, Google Messages.
By November 2020, RCS was available globally in Google Messages on Android, provided directly by Google if the operator does not provide RCS. By 2023, there were 800 million active RCS users on Google's platform and 1.2 billion handsets worldwide supporting RCS. Apple added support for RCS in Messages with iOS 18 on September 16, 2024, adding RCS support to all major smartphone manufacturers.
Internet Relay Chat
Internet Relay Chat (IRC) is an application layer protocol that facilitates communication in the form of text. The chat process works on a client/server networking model. IRC clients are computer programs that users can install on their system or web based applications running either locally in the browser or on a third party server. These clients communicate with chat servers to transfer messages to other clients. IRC is mainly designed for group communication in discussion forums, called channels, but also allows one-on-one communication via private messages as well as chat and data transfer, including file sharing.
Client software is available for every major operating system that supports Internet access. As of April 2011, the top 100 IRC networks served more than half a million users at a time, with hundreds of thousands of channels operating on a total of roughly 1,500 servers out of roughly 3,200 servers worldwide. IRC usage has been declining steadily since 2003, losing 60% of its users (from 1 million to about 400,000 in 2012) and half of its channels (from half a million in 2003).
Modern IRC
IRC has changed much over its life on the Internet. New server software has added a multitude of new features.
Services: Network-operated bots to facilitate registration of nicknames and channels, sending messages for offline users and network operator functions.
Extra modes: While the original IRC system used a set of standard user and channel modes, new servers add many new modes for features such as removing color codes from text, or obscuring a user's hostmask ("cloaking") to protect from denial-of-service attacks.
Proxy detection: Most modern servers support detection of users attempting to connect through an insecure (misconfigured or exploited) proxy server, which can then be denied a connection. This proxy detection software is used by several networks, although that real-time list of proxies is defunct since early 2006.
Additional commands: New commands can be such things as shorthand commands to issue commands to Services, to network-operator-only commands to manipulate a user's hostmask.
Encryption: For the client-to-server leg of the connection TLS might be used (messages cease to be secure once they are relayed to other users on standard connections, but it makes eavesdropping on or wiretapping an individual's IRC sessions difficult). For client-to-client communication, SDCC (Secure DCC) can be used.
Connection protocol: IRC can be connected to via IPv4, the old version of the Internet Protocol, or by IPv6, the current standard of the protocol.
, a new standardization effort is under way under a working group called IRCv3, which focuses on more advanced client features like instant notifications, better history support and improved security. , no major IRC networks have fully adopted the proposed standard.
After its golden era during the 1990s and early 2000s (240,000 users on QuakeNet in 2004), IRC has seen a significant decline, losing around 60% of users between 2003 and 2012, with users moving to newer social media platforms like Facebook or Twitter, but also to open platforms like XMPP which was developed in 1999. Certain networks like Freenode have not followed the overall trend and have more than quadrupled in size during the same period. As of 2016, Freenode is the largest IRC network with around 90,000 users.
The largest IRC networks have traditionally been grouped as the "Big Four"—a designation for networks that top the statistics. The Big Four networks change periodically, but due to the community nature of IRC there are a large number of other networks for users to choose from.
Historically the "Big Four" were:
EFnet
IRCnet
Undernet
DALnet
IRC reached 6 million simultaneous users in 2001 and 10 million users in 2003, dropping to 371k in 2018.
, the largest IRC networks are:
freenode – around 90k users at peak hours
IRCnet – around 30k users at peak hours
EFnet – around 18k users at peak hours
Undernet – around 17k users at peak hours
QuakeNet – around 15k users at peak hours
Rizon – around 14k users at peak hours
OFTC – around 13k users at peak hours
DALnet – around 8k users at peak hours
Today, the top 100 IRC networks have around 370k users connected at peak hours.
XMPP
Extensible Messaging and Presence Protocol (XMPP) is a communication protocol for message-oriented middleware based on XML (Extensible Markup Language). It enables the near-real-time exchange of structured yet extensible data between any two or more network entities. Originally named Jabber, the protocol was developed by the eponymous open-source community in 1999 for near real-time instant messaging (IM), presence information, and contact list maintenance. Designed to be extensible, the protocol has been used also for publish-subscribe systems, signalling for VoIP, video, file transfer, gaming, the Internet of Things (IoT) applications such as the smart grid, and social networking services.
Unlike most instant messaging protocols, XMPP is defined in an open standard and uses an open systems approach of development and application, by which anyone may implement an XMPP service and interoperate with other organizations' implementations. Because XMPP is an open protocol, implementations can be developed using any software license and many server, client, and library implementations are distributed as free and open-source software. Numerous freeware and commercial software implementations also exist.
The Internet Engineering Task Force (IETF) formed an XMPP working group in 2002 to formalize the core protocols as an IETF instant messaging and presence technology. The XMPP Working group produced four specifications (RFC 3920, RFC 3921, RFC 3922, RFC 3923), which were approved as Proposed Standards in 2004. In 2011, RFC 3920 and RFC 3921 were superseded by RFC 6120 and RFC 6121 respectively, with RFC 6122 specifying the XMPP address format. In 2015, RFC 6122 was superseded by RFC 7622. In addition to these core protocols standardized at the IETF, the XMPP Standards Foundation (formerly the Jabber Software Foundation) is active in developing open XMPP extensions.
XMPP-based software is deployed widely across the Internet, and by 2003, was used by over ten million people worldwide, according to the XMPP Standards Foundation.
SMS texting apps
Below are apps that are used for texting via SMS. Generally, these apps offer various features for expanded messaging, or group texts; however, all messages are received by others as regular SMS text messages.
Textfree
Textfree (formerly Pinger) is an application made by Pinger that allows users to text and call over the internet for free or for a price. The application runs on iOS, Android, Microsoft Windows and Macintosh devices. Competitors include GOGII, Optini and WhatsApp.
Stand-alone messaging platforms
Below are stand-alone apps that are generally focused upon instant messaging as their core feature; however, almost all of these also include numerous distinct additional features such as group chats, video calls, emojis, etc.
These apps do not use SMS messaging; rather, users of this app receive messages through the app interface, not through SMS texting.
Tango
Tango is a third-party, cross platform messaging application software for smartphones developed by TangoME, Inc. in 2009. The app is free and began as one of the first provider of video calls, voice calls, texting, photo sharing, and games on a 3G network.
As of 2018, Tango has more than 400 million registered users. It was rated by PCMag as "the simplest mobile chat application out there, with a good range of support."
In 2017, Tango entered the live-streaming space, and has become a B2C platform for Live Video Broadcasts. Combining high-quality video streaming, a live messaging chat and a digital economy, Tango is a social community that allows content creators to share their talents and monetize their fans and followers.
Tango is available in many languages including Russian, Spanish, Turkish, Hindi and Vietnamese.
WhatsApp
WhatsApp provides the following features, as detailed below.
Group threads: up to 250 members
Groups and channels: no built-in search function to find official groups and channels. anyone can join groups, if they have the link.
Video calls: up to 3 members.
WhatsApp is an American freeware, cross-platform messaging and Voice over IP (VoIP) service owned by Facebook, Inc. It allows users to send text messages and voice messages, make voice and video calls, and share images, documents, user locations, and other media. WhatsApp's client application runs on mobile devices but is also accessible from desktop computers, as long as the user's mobile device remains connected to the Internet while they use the desktop app. The service requires users to provide a standard cellular mobile number for registering with the service. In January 2018, WhatsApp released a standalone business app targeted at small business owners, called WhatsApp Business, to allow companies to communicate with customers who use the standard WhatsApp client.
The client application was created by WhatsApp Inc. of Mountain View, California, which was acquired by Facebook in February 2014 for approximately US$19.3 billion. It became the world's most popular messaging application by 2015, and has over 2billion users worldwide . It has become the primary means of electronic communication in multiple countries and locations, including Latin America, the Indian subcontinent, and large parts of Europe and Africa.
Telegram
Telegram provides the following features, as detailed below.
Group threads: up to 200,000 members
Groups and channels: provides numerous official channels for various organizations. Has an internal search feature to enable searches to find various official outlets.
Telegram is a cross-platform cloud-based instant messaging, video calling, and VoIP service. It was initially launched for iOS on 14 August 2013 in Russia, and is currently based in Dubai. Telegram client apps are available for Android, iOS, Windows Phone, Windows, macOS and Linux, web interface is also available. As of April 2020, Telegram reached 400 million monthly active users.
Telegram provides end-to-end encrypted calls and optional end-to-end encrypted "secret" chats between two online users on smartphone clients, whereas cloud chats use client-server/ server-client encryption.
Users can send text and voice messages, animated stickers, make voice and video calls, and share an unlimited number of images, documents(2GB per file), user locations, contacts, music, links etc.
SInce March 2017, Telegram introduced its own voice calls. According to Telegram, there is a neural network working to learn various technical parameters about a call to provide better quality of the service for future uses. After a brief initial trial in Western Europe, voice calls are now available for use in most countries.
Telegram announced in April 2020 that they would include group video calls by the end of the year. On 15 August 2020, Telegram added video calling with end-to-end encryption like Signal and WhatsApp, which Zoom does not have yet. Currently offering one-to-one video calls, Telegram has plans to introduce secure group video calls later in 2020. Picture-in-picture mode is also available so that users have the option to simultaneously use the other functions of the app while still remaining on the call and are even able to turn their video off.
Telegram's video and voice calls are secure and end-to-end encrypted.
Google Voice
Google Voice is a telephone service that provides call forwarding and voicemail services, voice and text messaging.
Google Voice provides a U.S. telephone number, chosen by the user from available numbers in selected area codes, free of charge to each user account. Calls to this number are forwarded to telephone numbers that each user must configure in the account web portal. Multiple destinations may be specified that ring simultaneously for incoming calls. Service establishment requires a United States telephone number. A user may answer and receive calls on any of the ringing phones as configured in the web portal. During a received call the user may switch between the configured telephones.
Users may place outbound calls to domestic and international destinations. Calls may be initiated from any of the configured telephones, as well as from a mobile device app, or from the account portal. As of August 2011, users in many other countries also may place outbound calls from the web-based application to domestic and international phone numbers.
Many other Google Voice services—such as voicemail, free text messaging, call history, call screening, blocking of unwanted calls, and voice transcription to text of voicemail messages—are also available to . In terms of product integration, transcribed and audio voicemails, missed call notifications, and/or text messages can optionally be forwarded to an email account of the user's choice. Additionally, text messages can be sent and received via the familiar email or IM interface by reading and writing text messages in numbers in Google Talk respectively (PC-to-Phone texting). Google Voice multi-way videoconferencing (with support for document sharing) is now integrated with Google Hangouts.
The service is configured and maintained by the user in a web-based application, styled after Google's e-mail service, Gmail, or with Android and iOS apps on smart phones or tablets. Google Voice provides free PC-to-phone calling within the United States and Canada, and PC-to-PC voice and video calling worldwide between users of the Google+ Hangouts browser plugin (available for Windows, Intel-based Mac OS X, and Linux).
GroupMe
GroupMe works by downloading the app or accessing the service online, and then forming an account by providing your name, cell phone number and a password, or you can connect through your Facebook or Twitter account. The service then syncs with your contacts and from that point forward the user can make groups, limited to 500 members. An individual who is part of an active group has the ability to turn off notifications for the app; users will still receive the message, but will not be notified about it. Each group is given a label and assigned a unique number. Some of the features of the app include the ability to share photos, videos, locations, create events, and emojis from various packs.
GroupMe has a web client as well as apps for iOS, Android, Windows Phone, and Windows 10.
Those who do not wish to use the app can still send and receive GroupMe messages through SMS (only available in the United States).
Users begin by creating a "group" and adding contacts. When someone sends a message, everyone in the group can see and respond to it. The app allows users to easily attach and send pictures, documents, videos and web-links as well. Users can also send private messages, but only to users who are also active on the GroupMe app.
GroupMe has been used as a means for studying the usage of messaging clients in educational settings. Use cases include facilitating online course discussions, small group work, and other course communications for both in-person and online sections. Though unconventional, using GroupMe to facilitate discussion in an environment where students already interact has been found to encourage rhetorical thinking and overall engagement. Researchers have found alternatives for literacy learning as a "legitimate academic genre", given a student population that communicates in a variety of modes. Research around GroupMe furthers the argument that computer-mediated communication is a valuable space for learning in an increasingly globalized society.
Hike Messenger
Hike Messenger, also called Hike Sticker Chat, is an Indian freeware, cross-platform instant messaging (IM), Voice over IP (VoIP) application which was launched on 12 December 2012 by Kavin Bharti Mittal and is now owned by Hike Private Limited. Hike can work offline through SMS and has multi-platform support. The app registration uses standard one time password (OTP) based authentication process. With abundance of low-cost data, Hike decided to go from a single super app strategy to multiple app approach, so that it can focus more on the core messaging capabilities. It has numerous Hikemoji Stickers which can be customized accordingly.From version 6, the user-interface was revised and the app no longer supports features like news, mobile payment, games or jokes. As per CB Insights, $1.4 billion is the valuation of Hike with more than 100 million registered users until August 2016 and 350 employees working from Bengaluru and Delhi.
KakaoTalk
KakaoTalk, commonly referred to as "KaTalk" in South Korea, is a free mobile instant messaging application for smartphones with free text and free call features, operated by Kakao Corporation. It was launched on March 18, 2010, and is currently available on iOS, Android, Bada OS, BlackBerry, Windows Phone, Nokia Asha, Windows and macOS.
As of May 2017, KakaoTalk had 220 million registered and 49 million monthly active users. It is available in 15 languages. The app is also used by 93% of smartphone owners in South Korea, where it is the number one messaging app.
In addition to free calls and messages, users can share photos, videos, voice messages, location, URL links as well as contact information. Both one-on-one and group chats are available over Wi-Fi, 3G or LTE, and there are no limits to the number of people on a group chat.
Airlines such as Southwest which allow free WhatsApp in flight also have functionality for KaTalk, even though their literature omits to mention same.
The app automatically synchronizes the user's contact list on their smartphones with the contact list on the app to find friends who are on the service. Users can also search for friends by KakaoTalk ID without having to know their phone numbers. The KakaoTalk service also allows its users to export their messages and save them.
KakaoTalk began as a messenger service but has become a platform for the distribution of various third-party content and apps, including hundreds of games, which users can download and play with their friends through the messaging platform. Through the "Plus Friend" feature, users can follow brands, media and celebrities to receive exclusive messages, coupons and other real-time information through KakaoTalk chatrooms. Users can also purchase real-life goods through the messenger's "Gifting" platform.
Besides those listed above, the app has these additional features:
VoiceTalk, free calls and conference calls (with support for up to five people)
Photo, video, location, and contact information sharing
Polling and scheduling feature for members in the chatroom
K-pop & Local Star Friends (Plus Friends)
Walkie-talkie
Customizable themes (for iOS and Android)
Game platform
Stickers and animated emoticons
Plus Mate: You can add your favorite brand, star, or media as your friend to receive a variety of content and benefits.
Kik Messenger
Kik Messenger, commonly called Kik, is a freeware instant messaging mobile app from the Canadian company Kik Interactive, available free of charge on iOS and Android operating systems. It uses a smartphone's data plan or Wi-Fi to transmit and receive messages, photos, videos, sketches, mobile web pages, and other content after users register a username. Kik is known for its features preserving users' anonymity, such as allowing users to register without the need to provide a telephone number or valid email address. However, the application does not employ end-to-end encryption, and the company also logs user IP addresses, which could be used to determine the user's ISP and approximate location. This information, as well as "reported" conversations are regularly surrendered upon request by law enforcement organizations, sometimes without the need for a court order.
Kik was originally intended to be a music-sharing app before transitioning to messaging, briefly offering users the ability to send a limited number of SMS text messages directly from the application. During the first 15 days after Kik's re-release as a messaging app, over 1 million accounts were created. In May 2016, Kik Messenger announced that they had approximately 300 million registered users, and was used by approximately 40% of United States' teenagers.
Kik Messenger announced in October 2019 they had signed a letter of intent with MediaLab AI, followed by the announcement Kik Interactive would be reducing their staff from 100 to just 19. MediaLab owns several mobile apps, most notably Whisper.
A main attraction of Kik that differentiates it from other messaging apps is its anonymity. To register for the Kik service, a user must enter a first and last name, e-mail address, and birth date (which must show that the user is at least 13 years old), and select a username. The Kik registration process does not request or require the entry of a phone number (although the user has the option to enter one), unlike some other messaging services that require a user to provide a functioning mobile phone number.
The New York Times has reported that, according to law enforcement, Kik's anonymity features go beyond those of most widely used apps. As of February 2016, Kik's guide for law enforcement said that the company cannot locate user accounts based on first and last name, e-mail address and/or birth date; the exact username is required to locate a particular account. The guide further said that the company does not have access to content or "historical user data" such as photographs, videos, and the text of conversations, and that photographs and videos are automatically deleted shortly after they are sent. A limited amount of data from a particular account (identified by exact username), including first and last name, birthdate, e-mail address, link to a current profile picture, device-related information, and user location information such as the most recently used IP address, can be preserved for a period of 90 days pending receipt of a valid order from law enforcement. Kik's anonymity has also been cited as a protective safety measure for good faith users, in that "users have screennames; the app doesn't share phone numbers or email addresses."
Kik introduced several new user features in 2015, including a full-screen in-chat browser that allows users to find and share content from the web; a feature allowing users to send previously recorded videos in Kik Messenger for Android and iOS; and "Kik Codes", which assigns each user a unique code similar to a QR code, making it easier to connect and chat with other users. Kik joined the Virtual Global Taskforce, a global anti-child-abuse organization, in March 2015. Kik began using Microsoft's PhotoDNA in March 2015 to premoderate images added by users. That same month, Kik released native video capture allowing users to record up to 15 seconds in the chat window. In October 2015, Kik partnered with the Ad Council as part of an anti-bullying campaign. The campaign was featured on the app and Kik released stickers in collaboration with the campaign. Kik released a feature to send GIFs as emojis in November 2015. Kik added SafePhoto to its safety features in October 2016 which "detects, reports, and deletes known child exploitation images" sent through the platform. Kik partnered with ConnectSafely in 2016 to produce a "parents handbook" and joined The Technology Coalition, an anti-sexual exploitation group including Facebook, Google, Twitter and LinkedIn.
Line
Line (styled in all caps as LINE) is a freeware app for instant communications on electronic devices such as smartphones, tablet computers, and personal computers. Line users exchange texts, images, video and audio, and conduct free VoIP conversations and video conferences. In addition, Line is a platform providing various services including digital wallet as Line Pay, news stream as Line Today, video on demand as Line TV, and digital comic distribution as Line Manga and Line Webtoon. The service is operated by Line Corporation, a Tokyo-based subsidiary of South Korean internet search engine company Naver Corporation.
Line is an application that works on multiple platforms and has access via multiple personal computers (Windows or macOS). The application will also give an option of address book syncing. This application also has a feature to add friends through the use of QR codes, by Line ID, and by shaking phones simultaneously. The application has a direct pop-out message box for reading and replying to make it easy for users to communicate. It also can share photos, videos and music with other users, send the current or any specific location, voice audio, emojis, stickers and emoticons to friends. Users can see a real-time confirmation when messages are sent and received or use a hidden chat feature, which can hide and delete a chat history (from both involved devices and Line servers) after a time set by the user. The application also makes free voice and video calls.
Users can also chat and share media in a group by creating and joining groups that have up to 500 people. Chats also provide bulletin boards on which users can post, like, and comment. This application also has timeline and homepage features that allow users to post pictures, text and stickers on their homepages. Users can also change their Line theme to the theme Line provides in the theme shop for free or users can buy other famous cartoon characters they like. Line also has a feature, called a Snap movie, that users can use to record a stop-motion video and add in provided background music.
In January 2015, Line Taxi was released in Tokyo as a competitor to Uber. Line launched a new android app called "Popcorn buzz" in June 2015. The app facilitates group calls with up to 200 members. In June a new Emoji keyboard was also released for iOS devices, which provides a Line-like experience with the possibility to add stickers. In September 2015 a new Android launcher was released on the Play Store, helping the company to promote its own services through the new user interface.
Signal
Signal is a cross-platform encrypted messaging service developed by the Signal Foundation and Signal Messenger LLC. It uses the Internet to send one-to-one and group messages, which can include files, voice notes, images and videos. It can also be used to make one-to-one voice and video calls, and the Android version can optionally function as an SMS app.
Signal uses standard cellular telephone numbers as identifiers and secures all communications to other Signal users with end-to-end encryption. The apps include mechanisms by which users can independently verify the identity of their contacts and the integrity of the data channel.
Snapchat
Snapchat sends messages referred to as "snaps"; snaps can consist of a photo or a short video, and can be edited to include filters and effects, text captions, and drawings. Snaps can be directed privately to selected contacts, or to a semi-public "Story" or a public "Story" called "Our Story." The ability to send video snaps was added as a feature option in December 2012. By holding down on the photo button while inside the app, a video of up to ten seconds in length can be captured. Spiegel explained that this process allowed the video data to be compressed into the size of a photo. A later update allowed the ability to record up to 60 seconds, but are still segmented into 10 second intervals. After a single viewing, the video disappears by default. On May 1, 2014, the ability to communicate via video chat was added. Direct messaging features were also included in the update, allowing users to send ephemeral text messages to friends and family while saving any needed information by clicking on it. According to CIO, Snapchat uses real-time marketing concepts and temporality to make the app appealing to users. According to Marketing Pro, Snapchat attracts interest and potential customers by combining the AIDA (marketing) model with modern digital technology.
Private message photo snaps can be viewed for a user-specified length of time (1 to 10 seconds as determined by the sender) before they become inaccessible. Users were previously required to hold down on the screen in order to view a snap; this behavior was removed in July 2015 The requirement to hold on the screen was intended to frustrate the ability to take screenshots of snaps; the Snapchat app does not prevent screenshots from being taken but can notify the sender if it detects that it has been saved. However, these notifications can be bypassed through either unauthorized modifications to the app or by obtaining the image through external means. One snap per day can be replayed for free. In September 2015, Snapchat introduced the option to purchase additional replays through in-app purchases. The ability to purchase extra replays was removed in April 2016.
Friends can be added via usernames and phone contacts, using customizable "Snapcodes," or through the "Add Nearby" function, which scans for users near their location who are also in the Add Nearby menu. Spiegel explained that Snapchat is intended to counteract the trend of users being compelled to manage an idealized online identity of themselves, which he says has "taken all of the fun out of communicating."
Viber
Rakuten Viber, or simply Viber, is a cross-platform voice over IP (VoIP) and instant messaging (IM) software application operated by Japanese multinational company Rakuten, provided as freeware for the Android, iOS, Microsoft Windows, macOS and Linux platforms. Users are registered and identified through a cellular telephone number, although the service is accessible on desktop platforms without needing mobile connectivity. In addition to instant messaging it allows users to exchange media such as images and video records, and also provides a paid international landline and mobile calling service called Viber Out. As of 2018, there are over a billion registered users on the network.
Wonder video chat
Wonder is a new style of shared video chat, using a virtual space where users can move between virtual rooms and initiate conversations either with a large group, or within a spontaneous "circle." The chat platforms is entirely browser-based, and does not entail or require the use of any specific app.
Dingtone
Dingtone is an application made by Dingtone that allows users to text and call over the internet for free or for a price. The application runs on Android, IOS, Microsoft Windows and Macintosh devices.
WeChat
WeChat is a Chinese multi-purpose messaging, social media and mobile payment app developed by Tencent. First released in 2011, it became the world's largest standalone mobile app in 2018, with over 1 billion monthly active users. WeChat has been described as China's "app for everything" and a "super app" because of its wide range of functions. WeChat provides text messaging, hold-to-talk voice messaging, broadcast (one-to-many) messaging, video conferencing, video games, sharing of photographs and videos, and location sharing.
WeChat provides text messaging, hold-to-talk voice messaging, broadcast (one-to-many) messaging, video calls and conferencing, video games, photograph and video sharing, as well as location sharing. WeChat also allows users to exchange contacts with people nearby via Bluetooth, as well as providing various features for contacting people at random if desired (if people are open to it). It can also integrate with other social networking services such as Facebook and Tencent QQ. Photographs may also be embellished with filters and captions, and automatic translation service is available.
WeChat supports different instant messaging methods, including text message, voice message, walkie talkie, and stickers. Users can send previously saved or live pictures and videos, profiles of other users, coupons, lucky money packages, or current GPS locations with friends either individually or in a group chat. WeChat's character stickers, such as Tuzki, resemble and compete with those of LINE, a Japanese-South Korean messaging application.
WeChat users can register as a public account (), which enables them to push feeds to subscribers, interact with subscribers and provide them with services. Users can also create an official account, which fall under service, subscription, or enterprise accounts. Once users as individuals or organizations set up a type of account, they cannot change it to another type. By the end of 2014, the number of WeChat official accounts had reached 8 million. Official accounts of organizations can apply to be verified (cost 300 RMB or about US$45). Official accounts can be used as a platform for services such as hospital pre-registrations, visa renewal or credit card service. To create an official account, the applicant must register with Chinese authorities, which discourages "foreign companies".
"Moments" () is WeChat's brand name for its social feed of friends' updates. "Moments" is an interactive platform that allows users to post images, text, and short videos taken by users. It also allows users to share articles and music (associated with QQ Music or other web-based music services). Friends in the contact list can give thumbs up to the content and leave comments. Moments can be linked to Facebook and Twitter accounts, and can automatically post Moments content directly on these two platforms.
In 2017 WeChat had a policy of a maximum of two advertisements per day per Moments user.
Platforms for combining multiple apps
Platforms specifically designed to combined messages from multiple other mobile apps.
Trillian
Trillian is a proprietary multiprotocol instant messaging application created by Cerulean Studios. It is currently available for Microsoft Windows, Mac OS X, Linux, Android, iOS, BlackBerry OS, and the Web. It can connect to multiple IM services, such as AIM, Bonjour, Facebook Messenger, Google Talk (Hangouts), IRC, XMPP (Jabber), VZ, and Yahoo! Messenger networks; as well as social networking sites, such as Facebook, Foursquare, LinkedIn, and Twitter; and email services, such as POP3 and IMAP.
Trillian no longer supports Windows Live Messenger or Skype as these services have combined and Microsoft chose to discontinue Skypekit. They also no longer support connecting to Myspace, and no longer support a distinct connection for Gmail, Hotmail or Yahoo! Mail although these can still be connected to via POP3 or IMAP. Currently, Trillian supports Facebook, Google, Jabber (XMPP), and Olark.
Initially released July 1, 2000, as a freeware IRC client, the first commercial version (Trillian Pro 1.0) was published on September 10, 2002. The program was named after Trillian, a fictional character in The Hitchhiker's Guide to the Galaxy by Douglas Adams. A previous version of the official web site even had a tribute to Douglas Adams on its front page. On August 14, 2009, Trillian "Astra" (4.0) for Windows was released, along with its own Astra network. Trillian 5 for Windows was released in May 2011, and Trillian 6.0 was initially released in February 2017.
Trillian connects to multiple instant messaging services without the need of running multiple clients. Users can create multiple connections to the same service, and can also group connections under separate identities to prevent confusion. All contacts are gathered under the same contact list. Contacts are not bound to their own IM service groups, and can be dragged and dropped freely.
Trillian represents each service with a different-colored sphere. Prior versions used the corporate logos for each service, but these were removed to avoid copyright issues, although some skins still use the original icons. The Trillian designers chose a color-coding scheme based on the underground maps used by the London Underground that uses different colors to differentiate between different lines.
Platforms for specific operating systems
Empathy
Empathy is an instant messaging (IM) and voice over IP (VoIP) client which supports text, voice, video, file transfers, and inter-application communication over various IM communication protocols. It is specifically designed for use with the operating systems BSD, Linux, and other Unix-like systems. It was initially completely XMPP based (similar to Google Talk and Facebook's chat implementations), but others wanted it to use the Telepathy stack. This led to the forking and new name Empathy.
Empathy also provides a collection of reusable graphical user interface widgets for developing instant messaging clients for the GNOME desktop. It is written as extension to the Telepathy framework, for connecting to different instant messaging networks with a unified user interface.
Empathy has been included in the GNOME desktop since its version 2.24, in Ubuntu since version 9.10 (Karmic Koala), and in Fedora since version 12 (Constantine); Empathy has replaced Pidgin as their default messenger application.
Messages for MacOS
Messages (Apple) is an instant messaging software application developed by Apple Inc. for its macOS, iOS, iPadOS, and watchOS operating systems.
The mobile version of Messages on iOS used on iPhone and iPad also supports SMS and MMS due to replacing the older text messaging Text app since iPhone OS 3. Users can tell the difference between a message sent via SMS and one sent over iMessage as the bubbles will appear either green (SMS) or blue (iMessage).
The desktop Messages application replaced iChat as the native OS X instant messaging client with the release of OS X Mountain Lion in July 2012. While it inherits the majority of iChat's features, Messages also brings support for iMessage, Apple's messaging service for iOS, as well as FaceTime integration.
Messages was announced for OS X as a beta application on February 16, 2012 for Macs running Mac OS X 10.7 "Lion". The stable release of Messages was released on July 25, 2012 with OS X Mountain Lion, replacing iChat. In addition to supporting Apple's new iMessage protocol, Messages retained its support for AIM, Yahoo! Messenger, Google Talk and Jabber.
Messages unitizes the newly added Notification Center to notify of incoming messages. The introduction of a new Share button in applications like Safari, Finder and Preview gave users the ability to share links to webpages, photos, and files. Messages also supported dragging and dropping files and photos for sharing. It also supports video calling through Apple's FaceTime and the third-party IM services it supports. With the release of OS X Mountain Lion 10.8.2, Messages gained the ability to send and receive iMessages using an iPhone phone number.
Messages received a major redesign in OS X Yosemite, following the flat design aesthetic introduced in iOS 7. As a part of the new Continuity feature, users can send and receive SMS and MMS messages through paired iPhones running iOS 8 or later.
Social networking mobile apps
A social networking service (also social networking site or social media) is an online platform which people use to build social networks or social relationships with other people who share similar personal or career interests, activities, backgrounds or real-life connections.
Social networking services vary in format and the number of features. They can incorporate a range of new information and communication tools, operating on desktops and on laptops, on mobile devices such as tablet computers and smartphones. They may feature digital photo/video/sharing and diary entries online (blogging). Online community services are sometimes considered social-network services by developers and users, though in a broader sense, a social-network service usually provides an individual-centered service whereas online community services are group-centered. Defined as "websites that facilitate the building of a network of contacts in order to exchange various types of content online," social networking sites provide a space for interaction to continue beyond in person interactions. These computer mediated interactions link members of various networks and may help to both maintain and develop new social and professional relationships
Social networking sites allow users to share ideas, digital photos and videos, posts, and to inform others about online or real-world activities and events with people in their network. While in-person social networking – such as gathering in a village market to talk about events – has existed since the earliest development of towns, the web enables people to connect with others who live in different locations, ranging from across a city to across the world. Depending on the social media platform, members may be able to contact any other member. In other cases, members can contact anyone they have a connection to, and subsequently anyone that contact has a connection to, and so on. The success of social networking services can be seen in their dominance in society today, with Facebook having a massive 2.13 billion active monthly users and an average of 1.4 billion daily active users in 2017. LinkedIn, a career-oriented social-networking service, generally requires that a member personally know another member in real life before they contact them online. Some services require members to have a preexisting connection to contact other members.
MeWe
MeWe is an American alt-tech social media and social networking service owned by Sgrouples, a company based in Culver City, California. MeWe's light approach to content moderation has made it popular among conspiracy theorists, particularly the anti-vaccine movement, as well as American conservatives. The site's interface has been described as similar to that of Facebook, though the company describes MeWe as the "anti-Facebook" due to its focus on data privacy
By 2015, as MeWe neared the end of its beta testing cycle, the press called MeWe's software "not dissimilar to Facebook". Mashable described MeWe as replicating Facebook's features in 2020.
The MeWe site and application has features common to most social media and social networking sites: users can post text and images to a feed, react to others' posts using emoji, post animated GIFs, create specialized groups, post disappearing content, and chat.
Online chat may occur between two or more people or among members of a group. Person-to-person online chat is similar to that in most other social media and social networking sites, and supports text, video calling, and voice calling. "Secret Chat" is limited to the paid subscription tier of MeWe, and uses double ratchet encryption to ensure that chats are private and not visible even to MeWe employees.
MeWe reported in June 2018 that the site had 90,000 active groups, 60,000 of which were "public" and open to all users. Following the influx of Hong Kong users in 2020, MeWe CEO Weinstein announced that the website would provide a Traditional Chinese language version by the end of the year.
User base and content
Although MeWe has not intentionally positioned itself as a social network for conservatives, Mashable noted in November 2020 that its active userbase trends conservative.The platform's choice not to moderate misinformation on the platform has attracted conservatives who felt mainstream social networks were censoring their posts, and those who have been banned from those platforms.
MeetMe
The Meet Group (formerly MeetMe) owns several mobile social networking services including MeetMe, hi5, LOVOO, Growlr, Skout, and Tagged.
The company has millions of mobile daily active users. Its mobile apps are available on iOS, and Android in multiple languages. Through these apps, users can stream live video, send gifts, chat, and share photos. The Meet Group derives revenue from in-app purchases, subscriptions, and advertising. The company has offices in New Hope, Pennsylvania, Philadelphia, San Francisco, Dresden, and Berlin.
The Meet Group has transformed its business from being a predominantly advertising model to now generating the majority of revenue from user pay sources, which include subscriptions and in-app purchases for virtual gifts as part of its video live-streaming product. The company also derives revenue from advertising. In the second quarter of 2018, 60% of revenue was derived from user-pay, versus 26% in the second quarter of 2017. Livestreaming video revenue has become an increasingly important component of revenue and growth, and the product has been rolled out to all of the company's main apps.
myYearbook derives its revenue from three sources: advertising, virtual-currency sales, and monthly subscriptions. Advertising makes up two-thirds of its revenue, with the other sources making up the rest. It has an established sales office based in New York City and Los Angeles.
Nextdoor
Nextdoor is a hyperlocal social networking service for neighborhoods. The company was founded in 2008 and is based in San Francisco, California. Nextdoor launched in the United States in October 2011, and is currently available in 11 countries. Users of Nextdoor are required to submit their real names and addresses (or street without the exact number) to the website; posts made to the website are available only to other Nextdoor members living in the same neighborhood.
Typical platform uses include neighbors reporting on news and events in their "neighborhood" and members asking each other for local service-provider recommendations. "Neighborhood" borders were initially established with Maponics, a provider of geographical information. According to the platform's rules, members whose addresses fall outside the boundaries of existing neighborhoods can establish their own neighborhoods. "Founding" members of neighborhoods determine the name of the neighborhood and its boundaries, although Nextdoor retains the authority to change either of these. A member must attract a minimum of 10 households to establish a new "neighborhood", as of November 2016.
While allowing for "civil debate", the platform prohibits canvassing for votes on forums. The service does however allow separate forums just for political discussions. According to The New York Times, these discussions are "separated from [a user's regular] neighborhood feeds". The company had established these separate forums in 12 markets by 2018. The company has stated it "has no plans" to accept political advertising.
Special-use platforms
U-Report
U-Report is a social messaging tool and data collection system developed by UNICEF to improve citizen engagement, inform leaders, and foster positive change. The program sends SMS polls and alerts to its participants, collecting real-time responses, and subsequently publishes gathered data. Issues polled include health, education, water, sanitation and hygiene, youth unemployment, HIV/AIDS, and disease outbreaks. The program currently has three million participants in forty-one countries.
Platforms that are internal features within major websites
Facebook
Facebook Messenger is an instant messaging service and software application. It began as Facebook Chat in 2008, was revamped in 2010 and eventually became a standalone mobile app in August 2011, while remaining part of the user page on browsers.
Complementing regular conversations, Messenger lets users make one-to-one and group voice and video calls. Its Android app has integrated support for SMS and "Chat Heads", which are round profile photo icons appearing on-screen regardless of what app is open, while both apps support multiple accounts, conversations with optional end-to-end encryption and "Instant Games". Some features, including sending money and requesting transportation, are limited to the United States. In 2017, Facebook added "Messenger Day", a feature that lets users share photos and videos in a story-format with all their friends with the content disappearing after 24 hours; Reactions, which lets users tap and hold a message to add a reaction through an emoji; and Mentions, which lets users in group conversations type @ to give a particular user a notification.
Businesses and users can interact through Messenger with features such as tracking purchases and receiving notifications, and interacting with customer service representatives. Third-party developers can integrate apps into Messenger, letting users enter an app while inside Messenger and optionally share details from the app into a chat. Developers can build chatbots into Messenger, for uses such as news publishers building bots to distribute news. The M virtual assistant (U.S.) scans chats for keywords and suggests relevant actions, such as its payments system for users mentioning money. Group chatbots appear in Messenger as "Chat Extensions". A "Discovery" tab allows finding bots, and enabling special, branded QR codes that, when scanned, take the user to a specific bot.
Instagram
In December 2013, Instagram announced Instagram Direct, a feature that lets users interact through private messaging. Users who follow each other can send private messages with photos and videos, in contrast to the public-only requirement that was previously in place. When users receive a private message from someone they don't follow, the message is marked as pending and the user must accept to see it. Users can send a photo to a maximum of 15 people. The feature received a major update in September 2015, adding conversation threading and making it possible for users to share locations, hashtag pages, and profiles through private messages directly from the news feed. Additionally, users can now reply to private messages with text, emoji or by clicking on a heart icon. A camera inside Direct lets users take a photo and send it to the recipient without leaving the conversation. A new update in November 2016 let users make their private messages "disappear" after being viewed by the recipient, with the sender receiving a notification if the recipient takes a screenshot.
In April 2017, Instagram redesigned Direct to combine all private messages, both permanent and ephemeral, into the same message threads. In May, Instagram made it possible to send website links in messages, and also added support for sending photos in their original portrait or landscape orientation without cropping.
In April 2020, Direct became accessible from the Instagram website.
In August 2020, Facebook started merging Instagram Direct into Facebook Messenger. After the update (which is rolled out to a segment of the user base) the Instagram Direct icon transforms into Facebook Messenger icon.
LinkedIn
The LinkedIn website includes a feature that allows direct messaging by a user to any other user who is on their list of Connections. Additionally, users with Premium membership can send messages to anyone on LinkedIn.
Reddit
In 2017, Reddit developed its own real-time chat software for the site. While some established subreddits have used third-party software to chat about their communities, the company built chat functions that it hopes will become an integral part of Reddit. Individual chat rooms were rolled out in 2017 and community chat rooms for members of a given subreddit were rolled out in 2018.
Twitter
Tweets are publicly visible by default, but senders can restrict message delivery to only their followers. Users can mute users they do not wish to interact with and block accounts from viewing their tweets. Users can tweet via the Twitter website, compatible external applications (such as for smartphones), or by Short Message Service (SMS) available in certain countries. Users may subscribe to other users' tweets—this is known as "following" and subscribers are known as "followers" or "tweeps", a portmanteau of Twitter and peeps. Individual tweets can be forwarded by other users to their own feed, a process known as a "retweet". Users can also "like" (formerly "favorite") individual tweets. Twitter allows users to update their profile via their mobile phone either by text messaging or by apps released for certain smartphones and tablets. Twitter has been compared to a web-based Internet Relay Chat (IRC) client. In a 2009 Time magazine essay, technology author Steven Johnson described the basic mechanics of Twitter as "remarkably simple":
Video conference platforms
Jitsi
Jitsi is a collection of free and open-source multiplatform voice (VoIP), video conferencing and instant messaging applications for the web platform, Windows, Linux, macOS, iOS and Android. The Jitsi project began with the Jitsi Desktop (previously known as SIP Communicator). It is totally free to use, and to host on a business's own server.
With the growth of WebRTC, the project team focus shifted to the Jitsi Videobridge for allowing web-based multi-party video calling. Later the team added Jitsi Meet, a full video conferencing application that includes web, Android, and iOS clients. Jitsi also operates meet.jit.si, a version of Jitsi Meet hosted by Jitsi for free community use. Other projects include: Jigasi, lib-jitsi-meet, Jidesha, and Jitsi.
Jitsi has received support from various institutions such as the NLnet Foundation, the University of Strasbourg and the Region of Alsace and it has also had multiple participations in the Google Summer of Code program.
Jitsi Meet is an open source JavaScript WebRTC application used primarily for video conferencing. In addition to audio and video, screen sharing is available, and new members can be invited via a generated link. The interface is accessible via web browser or with a mobile app. The Jitsi Meet server software can be downloaded and installed on Linux-based computers. Jitsi owner 8x8 maintains a free public-use server for up to 50 participants at meet.jit.si.
Key features of Jitsi Meet
Encrypted communication (secure communication): As of April 2020, one-to-one calls use the P2P mode, which is end-to-end encrypted via DTLS-SRTP between the two participants. Group calls also use DTLS-SRTP encryption, but rely on the Jitsi Videobridge (JVB) as video router, where packets are decrypted temporarily. The Jitsi team emphasizes that "they are never stored to any persistent storage and only live in memory while being routed to other participants in the meeting", and that this measure is necessary due to current limitations of the underlying WebRTC technology.
No need of new client software installation.
Skype
Skype is a proprietary telecommunications application that specializes in providing video chat and voice calls between computers, tablets, mobile devices, the Xbox One console, and smartwatches over the Internet. Skype also provides instant messaging services. Users may transmit text, video, audio and images. Skype allows video conference calls.
In March 2020, Skype was used by 100 million people on a monthly basis and by 40 million people on a daily basis, which was a 70% increase in the number of daily users from the previous month, due to the COVID-19 pandemic.
Registered users of Skype are identified by a unique Skype ID and may be listed in the Skype directory under a Skype username. Skype allows these registered users to communicate through both instant messaging and voice chat. Voice chat allows telephone calls between pairs of users and conference calling and uses proprietary audio codec. Skype's text chat client allows group chats, emoticons, storing chat history, and editing of previous messages. Offline messages were implemented in a beta build of version 5 but removed after a few weeks without notification. The usual features familiar to instant messaging users—user profiles, online status indicators, and so on—are also included.
The Online Number, a.k.a. SkypeIn, service allows Skype users to receive calls on their computers dialed by conventional phone subscribers to a local Skype phone number; local numbers are available for Australia, Belgium, Brazil, Chile, Colombia, Denmark, the Dominican Republic, Estonia, Finland, France, Germany, Hong Kong, Hungary, India, Ireland, Japan, Mexico, Nepal, New Zealand, Poland, Romania, South Africa, South Korea, Sweden, Switzerland, Turkey, the Netherlands, the United Kingdom, and the United States. A Skype user can have local numbers in any of these countries, with calls to the number charged at the same rate as calls to fixed lines in the country.
Skype supports conference calls, video chats, and screen sharing between 25 people at a time for free, which then increased to 50 on 5 April 2019.
Skype does not provide the ability to call emergency numbers, such as 112 in Europe, 911 in North America, 999 in the UK or 100 in India and Nepal. However, as of December 2012, there is limited support for emergency calls in the United Kingdom, Australia, Denmark, and Finland. The U.S. Federal Communications Commission (FCC) has ruled that, for the purposes of section 255 of the Telecommunications Act, Skype is not an "interconnected VoIP provider". As a result, the U.S. National Emergency Number Association recommends that all VoIP users have an analog line available as a backup.
Skype allows users to send instant messages to other users in their contact list. Messages sent to offline users are stored on Skype servers and will be delivered to their recipients as soon as they come online on Skype. Chat history along with the message status will be synchronized across all user devices supported by Skype whenever the user signs in with the same Skype account.
Although Skype allows sending SMS messages, it is not possible to receive SMS messages on Skype so users need a different way to receive responses to the messages they send using Skype. This has been a cause of angst among user who purchase Skype as an alternative to a mobile phone because Microsoft will not refund any purchases even for users who discover this missing feature only after purchasing multi-year contracts. Other than in user complaints on the Microsoft Skype forums, there is no mention on Microsoft or Skype websites that when they say "Send SMS messages," that is just what they mean: users can send but they cannot receive SMS messages.
Skype keeps user instant messaging history on user's local computer, and on Skype's cloud for 30 days. Users cannot control how long their chat histories are stored on Skype's servers but can configure that option individually for every their device. Once user signs into Skype on a new device the conversation history is synced with Skype's cloud and stored locally. Skype allows users to remove or edit individual messages during one hour after sending; this affects messages already received by chat interlocutors as well as not delivered to them yet. Skype allows users to delete all saved conversation histories for the device.
FaceTime
FaceTime is a proprietary videotelephony product developed by Apple Inc. It is available on supported iOS mobile devices running iOS 4 and later and Mac computers that run and later. FaceTime supports any iOS device with a forward-facing camera and any Mac computer equipped with a FaceTime Camera. FaceTime Audio, an audio-only version, is available on any iOS device that supports iOS 7 or newer, and any Mac with a forward-facing camera running and later. FaceTime is included for free in iOS and in macOS from (10.7) onwards.
Apple bought the "FaceTime" name from FaceTime Communications, which changed its name to Actiance in January 2011. On June 7, 2010, Apple CEO Steve Jobs announced FaceTime in conjunction with the iPhone 4 in a keynote speech at the 2010 Apple Worldwide Developers Conference. Support for the fourth generation iPod Touch (the first model of iPod Touch equipped with cameras) was announced in conjunction with the device's release on September 8, 2010. FaceTime for was announced on October 20, 2010.
In May 2011, it was found that FaceTime would work seamlessly over 3G on all iPhone, iPad, and iPod Touch models that supported it. Even though FaceTime worked only over 3G at that time, it now supports 4G LTE calls on networks all over the world, availability being limited to operators' GSM plans.
In 2018, Apple added group video and audio support to FaceTime which can support up to 32 people in iOS 12 and macOS Mojave.
Zoom
Zoom is a videotelephony software program developed by Zoom Video Communications. The free version provides a video chatting service that allows up to 100 devices at once, with a 40-minute time restriction for free accounts having meetings of three or more participants. Users have the option to upgrade by subscribing to one of its plans, with the highest allowing up to 1,000 people concurrently, with no time restriction.
Zoom is compatible with Windows, macOS, iOS, Android, ChromeOS, and Linux. It is noted for its simple interface and usability, specifically for non-tech people. Features include one-on-one meetings, group video conferences, screen sharing, plugins, browser extensions, and the ability to record meetings and have them automatically transcribed. On some computers and operating systems, users are able to select a virtual background, which can be downloaded from different sites, to use as a backdrop behind themselves.
Use of the platform is free for video conferences of up to 100 participants at once, with a 40-minute time limit if there are more than two participants. For longer or larger conferences with more features, paid subscriptions are available, costing $15–20 per month. Features geared towards business conferences, such as Zoom Rooms, are available for $50–100 per month. Up to 49 people can be seen on a screen at once. Zoom has several tiers: Basic, Pro, Business, and Enterprise. Participants do not have to download the app if they are using Google Chrome or Firefox; they can click on a link and join from the browser. Zoom is not compatible with Safari for Macs.
Zoom security features include password-protected meetings, user authentication, waiting rooms, locked meetings, disabling participant screen sharing, randomly generated IDs, and the ability for the host to remove disruptive attendees. As of June 2020, Zoom began offering end-to-end encryption to business and enterprise users, with AES 256 GCM encryption enabled for all users. In October 2020, Zoom added end-to-end encryption for free and paid users. It's available on all platforms, except for the official Zoom web client.
Zoom also offers a transcription service using Otter.ai software that allows businesses to store transcriptions of the Zoom meetings online and search them, including separating and labeling different speakers.
As of July 2020, Zoom Rooms and Zoom Phone also became available as hardware as a service products. Zoom Phone is available for domestic telephone service in 40 countries as of August 2020. Zoom for Home, a category of products designed for home use, became available in August 2020.
Google Duo
Google Duo is a video chat mobile app developed by Google, available on the Android and iOS operating systems. It was announced at Google's developer conference on May 18, 2016, and began its worldwide release on August 16, 2016. It is also available to use via Google's Chrome web browser on desktop and laptop computers.
Google Duo lets users make video calls in high definition. It is optimized for low-bandwidth networks. End-to-end encryption is enabled by default. Duo is based on phone numbers, allowing users to call someone from their contact list. The app automatically switches between Wi-Fi and cellular networks. A "Knock Knock" feature lets users see a live preview of the caller before answering. An update in April 2017 lets users worldwide make audio-only calls.
As of December 1, 2016, Google Duo replaced Hangouts within the suite of Google apps device manufacturers must install in order to gain access to the Google Play Store, with Hangouts instead becoming optional.
In August 2020, it was reported that Google was planning to eventually replace Google Duo with Google Meet, but would continue to support Duo and "invest in building new features" in the long term.
Google Hangouts
Google Hangouts is a cross-platform messaging app developed by Google. Originally a feature of Google+, Hangouts became a stand-alone product in 2013, when Google also began integrating features from Google+ Messenger and Google Talk into Hangouts. In 2017, Google began developing Hangouts into a product aimed at enterprise communication, splitting into two products: Google Meet and Google Chat.
Google has also begun integrating features of Google Voice, its IP telephony product, into Hangouts, stating that Hangouts is designed to be "the future" of Voice. Google began transitioning users from the "classic" version of Hangouts to Meet and Chat in June 2020, and announced in October 2020 that Google Chat would eventually be made free to consumers and fully replace Hangouts, shortly after Google Meet became free as well. Google Hangouts will remain a consumer-level product for people using standard Google accounts.
Google Hangouts has a unique feature in that it allows video calls to be streamed live via YouTube.
Google Meet
Google Meet (formerly known as Hangouts Meet) is a video-communication service developed by Google. It is one of two apps that constitute the replacement for Google Hangouts, the other being Google Chat.
User features of Google Meet include:
Two-way and multi-way audio and video calls with a resolution up to 720p
An accompanying chat
Call encryption between all users
Noise cancelling audio filter
Low-light mode for video
Ability to join meetings through a web browser or through Android or iOS apps
Integration with Google Calendar and Google Contacts for one-click meeting calls
Screen-sharing to present documents, spreadsheets, presentations, or (if using a browser) other browser tabs
Ability to call into meetings using a dial-in number in the US
Hosts being able to deny entry and remove users during a call.
Google Meet uses proprietary protocols for video, audio and data transcoding. However, Google has partnered with the company Pexip to provide interoperability between Google Meet and SIP/H.323-based conferencing equipment and software.
Features for users who use Google Workspace accounts include:
Up to 100 members per call for Google Workspace Starter users, up to 150 for Google Workspace Business users, and up to 250 for Google Workspace Enterprise users
Ability to call into meetings with a dial-in number from selected countries
Password-protected dial-in numbers for Google Workspace Enterprise edition users
Real-time closed captioning based on speech recognition
Background blurring
In March 2020, Google temporarily extended advanced features present in the enterprise edition to anyone using Google Workspace or G Suite for Education editions.
In March 2020, Google rolled out Meet to personal (free) Google accounts.
Free Meet calls can only have a single host and up to 100 participants, compared to the 250-caller limit for Google Workspace users and the 25-participant limit for Hangouts. Unlike business calls with Meet, consumer calls are not recorded and stored, and Google states that consumer data from Meet will not be used for advertisement targeting. While call data is reportedly not being used for advertising purposes, based on an analysis of Meet's privacy policy, Google reserves the right to collect data on call duration, who is participating, and participants' IP addresses.
Users need a Google account to initiate calls and like Google Workspace users, anyone with a Google account is able to start a Meet call from within Gmail.
Marco Polo
Marco Polo (app) is a video messaging and video hosting service mobile app. The app was created in 2014 by Joya Communications, founded by Vlada Bortnik and Michael Bortnik. The app markets itself as a video walkie talkie.
Device-specific platforms
iMessage for iPhones
iMessage is an instant messaging service developed by Apple Inc. and launched in 2011. iMessage functions exclusively on Apple platforms: macOS, iOS, iPadOS, and watchOS.
Core features of iMessage, available on all supported platforms, include sending texts, images, videos, and documents; getting delivery and read statuses (read receipts); and end-to-end encryption (which means no one, including Apple itself, is able to intercept or tamper with sent messages). On all platforms except macOS, the service also allows sending location data and stickers. On iOS and iPadOS, third-party developers can extend iMessage capabilities with custom extensions (an example being quick sharing of recently played songs).
Launched on iOS in 2011, iMessage arrived on macOS (then called OS X) in 2012. In 2020, Apple announced an entirely redesigned version of the macOS Messages app which adds some of the features previously unavailable on the Mac, including location sharing and message effects.
Google Messages
Google Messages is an SMS and instant messaging application developed by Google for its Android mobile operating system. A web interface is also available. Launched in 2014, it has supported Rich Communication Services (RCS) messaging since 2018, marketed as "Chat" features. By April 2020, the app had more than a billion installs which was most likely due to Google's wider roll out of RCS to many different countries without carrier support.
Palringo
Palringo, or The World's Online Festival (WOLF), is a community-oriented messaging and gaming app for iOS and Android. The platform allows users to chat, entertain, and perform on a Stage—live microphone slots for up to 5 people, form and join large groups based on common interests, send instant messages and drop images and voice recordings into conversations. Launched under its original name of Palringo in 2006, the app has 80 million accounts worldwide and offers a range of games along with more than 380,000 groups, some of which have up to 2,500 members. Headquartered in London, WOLF has offices in Newcastle and London, UK, and Amman, Jordan.
Groupware
"Groupware" refers to a number of varied applications that are designed to enable communication amongst members of a team, either within a company, a project, or some other group effort. these applications may incorporate a vast range of features and functions, rather than a single specialized function. Such platforms may include instant messaging, document sharing, visual diagrams, voice conference, and many other team-oriented features.
Microsoft Yammer
Yammer is a freemium enterprise social networking service used for private communication within organizations. Access to a Yammer network is determined by a user's Internet domain so that only individuals with approved email addresses may join their respective networks.
The service began as an internal communication system for the genealogy website Geni.com, and was launched as an independent product in 2008. Microsoft later acquired Yammer in 2012 for US$1.2 billion. Currently Yammer is included in all enterprise plans of Office 365 and Microsoft 365.
Adobe Connect
Adobe Connect (formerly Presedia Publishing System, Macromedia Breeze, and Adobe Acrobat Connect Pro) is a suite of software for remote training, web conferencing, presentation, and desktop sharing. All meeting rooms are organized into 'pods'; with each pod performing a specific role (e.g. chat, whiteboard, note etc.) Adobe Connect was formerly part of the Adobe Acrobat family and has changed names several times.
Google Workspace
Google Workspace, formerly known as G Suite, is a collection of cloud computing, productivity and collaboration tools, software and products developed and marketed by Google. It was first launched in 2006 as Google Apps for Your Domain and rebranded as G Suite in 2016. Google Workspace consists of Gmail, Contacts, Calendar, Meet and Chat for communication; Currents for employee engagement; Drive for storage; and the Google Docs suite for content creation. An Admin Panel is provided for managing users and services. Depending on edition Google Workspace may also include the digital interactive whiteboard Jamboard and an option to purchase such add-ons as the telephony service Voice. The education edition adds a learning platform Google Classroom and as of October 2020 retains the name G Suite for Education.
While most of these services are individually available at no cost to consumers who use their free Google (Gmail) accounts, Google Workspace adds enterprise features such as custom email addresses at a domain (e.g. @yourcompany.com), an option for unlimited Drive storage, additional administrative tools and advanced settings, as well as 24/7 phone and email support.
Being based in Google's data centers, data and information are saved directly and then synchronized to other data centers for backup purposes. Unlike the free, consumer-facing services, Google Workspace users do not see advertisements while using the services, and information and data in Google Workspace accounts do not get used for advertisement purposes. Furthermore, Google Workspace administrators can fine-tune security and privacy settings.
Google Chat
Google Chat is a communication software developed by Google built for teams that provides direct messages and team chat rooms, similar to competitors Slack and Microsoft Teams, along with a group messaging function that allows Google Drive content sharing. It is one of two apps that constitute the replacement for Google Hangouts, the other being Google Meet. Google planned to begin retiring Google Hangouts in October 2019.
The current version is for Google Workspace, (formerly G Suite until October 2020) customers only, with identical features in all packages except a lack of Vault data retention in the Basic package. However, in October 2020, Google announced plans to open Google Chat up to consumers as early as 2021, once Hangouts has been officially retired.
Slack
Slack offers many IRC-style features, including persistent chat rooms (channels) organized by topic, private groups, and direct messaging. Content, including files, conversations, and people, is all searchable within Slack. Users can add emoji buttons to their messages, on which other users can then click to express their reactions to messages.
Slack's free plan allows only the 10,000 most recent messages to be viewed and searched. On March 18, 2020, Slack redesigned its platform to simplify and customize the user experience.
Slack teams allow communities, groups, or teams to join a "workspace" via a specific URL or invitation sent by a team admin or owner. Although Slack was developed for professional and organizational communication, it has been adopted as a community platform, replacing message boards or social media groups.
Public channels allow team members to communicate without the use of email or group SMS (texting). Public channels are open to everyone in the workspace. Private channels allow for private conversation between smaller sub-groups. These private channels can be used to organize large teams. Direct messages allow users to send private messages to specific users rather than a group of people. Direct messages can include up to nine people. Once started, a direct message group can be converted into a private channel.
Slack integrates with many third-party services and supports community-built integrations, including Google Drive, Trello, Dropbox, Box, Heroku, IBM Bluemix, Crashlytics, GitHub, Runscope, Zendesk and Zapier. In December 2015, Slack launched their software application ("app") directory, consisting of over 150 integrations that users can install.
In March 2018, Slack announced a partnership with financial and human capital management firm Workday. This integration allows Workday customers to access Workday features directly from the Slack interface.
Discord
Discord is built to create and manage private and public communities. It gives users access to tools focused around communication like voice and video calls, persistent chat rooms and integrations with other gamer-focused services.
Discord communities are organized into discrete collections of channels called servers. A user can create servers for free, manage their public visibility and create one or more channels within that server.
Starting October 2017, Discord allows game developers and publishers to verify their servers. Verified servers, like verified accounts on social media sites, have badge to mark them as official communities. Verified servers are moderated by the developer's or publisher's own moderation team. Verification was later extended in February 2018 to include esports teams and musical artists.
By the end of 2017, about 450 servers were verified. Approximately 1790 servers are verified as of December 2020.
Discord users can improve the quality of the servers they reside in via the "Server Boost" feature, which improves quality of audio channels, streaming channels, number of emoji slots and other perks in 3 levels. Users can buy boosts to support the servers they choose, for a monthly amount. Possession of "Discord Nitro", the platform's paid subscription, gives a user two extra boosts to use on any server they like.
Channels may be either used for voice chat and streaming or for instant messaging and file sharing. The visibility and access to channels can be customized to limit access from certain users, for example marking a channel "NSFW" (Not Safe For Work) requires that first-time viewers confirm they are over 18 years old and willing to see such content.
Kune
Kune is a free/open source distributed social network focused on collaboration rather than just on communication. That is, it focuses on online real-time collaborative editing, decentralized social networking and web publishing, while focusing on workgroups rather than just on individuals. It aims to allow for the creation of online spaces for collaborative work where organizations and individuals can build projects online, coordinate common agendas, set up virtual meetings, publish on the web, and join organizations with similar interests. It has a special focus on Free Culture and social movements needs. Kune is a project of the Comunes Collective.
All the functionalities of Apache Wave, that is collaborative federated real-time editing, plus
Communication
Chat and chatrooms compatible with Gmail and Jabber through XMPP (with several XEP extensions), as it integrates Emite
Social networking (federated)
Real-time collaboration for groups in:
Documents: as in Google Docs
Wikis
Lists: as in Google Groups but minimizing emails, through waves
Group Tasks
Group Calendar: as in Google Calendar, with ical export
Group Blogs
Web-creation: aiming to publish contents directly on the web (as in WordPress, with a dashboard and public view) (in development)
Bartering: aiming to decentralize bartering as in eBay
Advanced email
Waves: aims to replace most uses of email
Inbox: as in email, all your conversations and documents in all kunes are controlled from your inbox
Email notifications (Projected: replies from email)
Multimedia & Gadgets
Image or Video galleries integrated in any doc
Maps, mindmaps, Twitter streams, etc.
Polls, voting, events, etc.
and more via Apache Wave extensions, easy to program (as in Facebook apps, they run on top of Kune)
See also
Comparison of cross-platform instant messaging clients
Comparison of instant messaging protocols
Comparison of Internet Relay Chat clients
Comparison of LAN messengers
Comparison of VoIP software
List of SIP software
List of video telecommunication services and product brands
References
External links
Comparison articles and overviews
15 Group Messaging Mobile Apps, November 5, 2019, by Sig Ueland, practicalecommerce.com.
The Ultimate Group Text App Guide, Last updated February 17, 2020, snapdesk.app website.
Wikimedia pages
Wikimedia list of conference platforms
Social media
Android Auto software
VoIP software
Mobile applications
Android (operating system) software
IOS software
Instant messaging clients
Cross-platform software
Communication software
Computer-mediated communication
Groupware
Collaborative software
Network software comparisons
user features of messaging platforms
Messaging platforms | Comparison of user features of messaging platforms | [
"Technology"
] | 18,863 | [
"Online services comparisons",
"Computing comparisons",
"Instant messaging clients",
"Instant messaging",
"Information systems",
"Computing and society",
"Software comparisons",
"Computer-mediated communication",
"Social media"
] |
51,724,747 | https://en.wikipedia.org/wiki/Single%20pushout%20graph%20rewriting | In computer science, a single pushout graph rewriting or SPO graph rewriting refers to a mathematical framework for graph rewriting, and is used in contrast to the double-pushout approach of graph rewriting.
References
Further reading
Graph rewriting | Single pushout graph rewriting | [
"Mathematics",
"Technology"
] | 52 | [
"Graph theory stubs",
"Graph theory",
"Computer science stubs",
"Computer science",
"Mathematical relations",
"Computing stubs",
"Graph rewriting"
] |
51,725,104 | https://en.wikipedia.org/wiki/Attributed%20graph%20grammar | In computer science, an attributed graph grammar is a class of graph grammar that associates vertices with a set of attributes and rewrites with functions on attributes. In the algebraic approach to graph grammars, they are usually formulated using the double-pushout approach or the single-pushout approach.
Implementation
AGG, a rule-based visual language that directly expresses attributed graph grammars using the single-pushout approach has been developed at TU Berlin for many years.
Notes
References
.
Ehrig, Heckel, Korff, Lowe, Ribeiro, Wagner and Corradini, 1997. Algebraic Approaches to Graph Transformation - Part II: Single Pushout Approach and Comparison with Double Pushout Approach. Pp. 247-312 of (Rozenberg, 1997).
Graph rewriting | Attributed graph grammar | [
"Mathematics"
] | 160 | [
"Graph theory stubs",
"Mathematical relations",
"Graph theory",
"Graph rewriting"
] |
51,725,450 | https://en.wikipedia.org/wiki/NGC%20243 | NGC 243 is a lenticular galaxy located in the constellation Andromeda. It was discovered on October 18, 1881 by Édouard Stephan.
According to A.M. Garcia, NGC 243 is a member of the NGC 315 Group (also known as LGG 14). This group contains 42 galaxies, including NGC 226, NGC 262, NGC 266, NGC 311, NGC 315, NGC 338, IC 43, IC 66, AND IC 69, among others.
References
External links
0243
Lenticular galaxies
Andromeda (constellation)
002687
Discoveries by Édouard Stephan | NGC 243 | [
"Astronomy"
] | 116 | [
"Andromeda (constellation)",
"Constellations"
] |
51,725,711 | https://en.wikipedia.org/wiki/NGC%20244 | NGC 244 is a lenticular galaxy located in the constellation Cetus. It was discovered on December 30, 1785 by William Herschel.
See also
List of NGC objects (1–1000)
References
External links
0244
Lenticular galaxies
Cetus
002675
010
-03-03-003
F00432-1552
Discoveries by William Herschel
17851230 | NGC 244 | [
"Astronomy"
] | 77 | [
"Cetus",
"Constellations"
] |
51,725,745 | https://en.wikipedia.org/wiki/NGC%20245 | NGC 245 is a spiral galaxy located in the constellation Cetus. It was discovered on October 1, 1785 by William Herschel.
References
External links
0245
Spiral galaxies
Cetus
00476
Markarian galaxies
002691 | NGC 245 | [
"Astronomy"
] | 47 | [
"Cetus",
"Constellations"
] |
51,725,788 | https://en.wikipedia.org/wiki/Plankton%20net | A plankton net is equipment used for collecting samples of plankton in standing bodies of water. It consists of a towing line and bridles, nylon mesh net, and a cod end. Plankton nets are considered one of the oldest, simplest and least expensive methods of sampling plankton. The plankton net can be used for both vertical and horizontal sampling. It allows researchers to analyse plankton both quantitatively (cell density, cell colony or biomass) and qualitatively (e.g. Chlorophyll-a as a primary production of phytoplankton) in water samples from the environment.
Components
Towing line and bridle
The towing line and bridle is the upper part of a plankton net and used to hold it. The towing lines connected to the triangle bridles are made of nylon rope and can be adjust to a level suitable for the user.
Nylon mesh net
The nylon mesh net is the middle part of the plankton net and is used to filter the plankton in the water sample in accordance with the size of the mesh. In addition, its funnel shape makes it possible to effectively capture plankton of various sizes. There are various mesh sizes for nets, depending on the target microorganism to be collected and the condition of the water body. The narrower the mesh size, the smaller the plankton in the water sample. For example, in order to obtain small invertebrates measuring 50 to 1500 μm, a net mesh size between 25 and 50 μm diameter should be selected, which is sufficient to effectively filter only the target organism. However, in a eutrophic water condition, a plankton net with a mesh larger than 100 μm should be chosen to avoid clogging the net.
Cod end
The cod end is located in the lower part of the plankton net at the end of the funnel. It has a collecting cylinder and a valve for opening and closing it.
Use
One common method for collecting a plankton sample is to tow the net horizontally using a low-speed boat. Before collecting the plankton, the net should be rinsed with the sample water. The user should ensure that the cod end is completely closed by turning the valve into a vertical position. Then the plankton net is then lowered horizontal to the water surface at the side of the slowly moving boat. Sampling is done for 1.5 minutes. After this time, the plankton sample is collected in a sample bottle by opening the cod end above it by turning the valve horizontally.
When the sample is collected it can be analyzed using a microscope to identify the type of zooplankton or phytoplankton, or a cell count can be undertaken to determine the plankton cell density of the water source.
History
John Vaughan Thompson developed a plankton net during his return voyage from Mauritius, which reached the UK in 1816. Impressed by marine bioluminescence in small crustacea he later named Sapphirina, he felt "under great obligations to this beautiful little animal, which by its splendid appearance in the water induced me to commence the use of a muslin hoop-net, which when it failed to procure me a specimen, brought up such a profusion of other marine animals altogether invisible while in the sea, as to induce a continued use of it on every favourable opportunity." He published his research in a series of six memoirs from 1828 to 1834.
The second recorded use of a plankton net was by Charles Darwin on 10 January 1832, during the Beagle survey voyage. His diary included a sketch of the net, which appears to have been based on a trawl net described by John Coldstream in a letter to Darwin. It is possible that Thompson's idea had earlier been drawn to Darwin's attention by Robert Edmond Grant in Edinburgh. Darwin describes this "contrivance" as "a bag four feet deep, made of bunting, & attached to [a] semicircular bow this by lines is kept upright, & dragged behind the vessel". The next day he remarked that "The number of animals that the net collects is very great & fully explains the manner so many animals of a large size live so far from land. — Many of these creatures so low in the scale of nature are most exquisite in their forms & rich colours. — It creates a feeling of wonder that so much beauty should be apparently created for such little purpose."
See also
Ichthyoplankton sampling methods
Continuous Plankton Recorder
Video plankton recorder
References
Microbiology equipment
Planktology | Plankton net | [
"Biology"
] | 927 | [
"Microbiology equipment"
] |
51,725,805 | https://en.wikipedia.org/wiki/BOD%20bottle | BOD Bottle or an incubation bottle is a main apparatus used for the Biological Oxygen Demand (BOD) test. During the five-day BOD or BOD5 test process, the BOD bottle is used for incubating diluted samples under the 20 °C or 68 °F of temperature.
Structure
The bottle is normally designed to have a special shoulder radius to push out all air from the inside of the bottle when a sample solution is being filled. According to Method 5210 in Standard Methods for the Examination of Water and Wastewater, the BOD bottle should include a ground-glass stopper and a flared mouth which form a water seal preventing the air from the outside of the bottle coming in. Method 5210 also recommends to use a paper, a foil or a plastic cup to cap over the mouth of the bottle reducing the evaporation during the incubation. Generally, the side of the BOD bottle is permanently screened with white writing area, and is printed with a specific number; both for the aid of the sample identification.
Stopper
There are two kinds of stopper: the Glass Pennyhead and the Glass Robotic stopper.
Sizes
There are many BOD bottle sizes. The dose of the mixture of the solution (nutrient, mineral and buffer solution) is related to the size of the bottle. For the Standard Methods 5210, the BOD bottle “having 60 mL or greater capacity (300-mL)” is mentioned as one of the apparatus for the BOD test. A 60 mL BOD bottle is available and listed as "often convenient" by EPA (Environmental Protection Agency) Method 405.1. However, EPA Method 405.1 was written in 1974 and is no longer an EPA-approved method per 40CFR Part 136.
Materials
Glass is a material being specified in the Standard Methods 5210 of the BOD5 test. The glass bottles are manufactured from Type 1 borosilicate glass.
A black BOD bottle
A black BOD bottle is coated with PVC plastic that blocks visible light. Black bottles are used in marine photosynthesis projects which needs to compare oxygen levels in light and dark conditions.
Disposable BOD Bottle or Carbonaceous Biochemical Oxygen Demand (CBOD) Bottle
It is a carbon-coated polyethylene terephthalate (PET) bottle that is solely manufactured by Environmental Express in Charleston, SC. The bottle is lightweight, unbreakable, and recyclable. Since the bottle is designed for single-use, it eliminates any potential for cross-contamination between samples. The bottle does not require any resources nor energy for cleaning and rinsing as it is disposable. CBOD bottle is also claimed to be cheaper, and cause less contamination in the sample solution than the conventional- BOD bottle.
References
Measuring instruments
Liquid containers | BOD bottle | [
"Technology",
"Engineering"
] | 577 | [
"Measuring instruments"
] |
51,725,837 | https://en.wikipedia.org/wiki/Inoculation%20needle | An inoculation needle is a laboratory equipment used in the field of microbiology to transfer and inoculate living microorganisms. It is one of the most commonly implicated biological laboratory tools and can be disposable or re-usable. A standard reusable inoculation needle is made from nichrome or platinum wire affixed to a metallic handle. A disposable inoculation needle is often made from plastic resin. The base of the needle is dulled, resulting in a blunted end.
Uses
Inoculation needles are primarily applied in microbiology for studying bacteria and fungi on semi-solid media. Biotechnology, cell biology and immunology may also utilize needle-oriented culture methods.
The application of inoculation needles focuses on the inoculation and isolation of very defined regions of the cultures and the requirements of least disturbance between two closely crowded microbial colonies. It can also be used in harpooning under a low magnification microscope.
Streaking on streak plates, fish tail inoculation of slant cultures and the inoculation of stab cultures can be done with the inoculation needle. Stab cultures specifically require the inoculation needle and is used to study cell motility, microbial oxygen requirements using Thioglycolate cultures, and the gelatin liquefaction of bacteria.
Operation
Sterilization
The inoculation needle is sterilized using the aseptic technique. An open flame from an incinerator, a bunsen burner, or an alcohol burner is used to flame along the tip and the length of the needle that is to be in contact with the inoculum (or the propagule). For ease of manipulation it is common practice to hold the needle with the dominant hand as if handling a pencil. The needle will be flamed at a downward angle through the flame's inner cone until it is red-hot. The downward angle will minimize the amount of microbial aerosols created.
Inoculation needles must be sterilized prior and following contact with microbial life forms to ensure no contamination of the culture, the sterile mediums, and the surrounding environment.
Transfer
In inoculation the inoculation needle is first employed to transfer microbial life forms from a culture to the needle to be used in further inoculating procedures. Sources of inoculum include broth cultures, slant cultures, and plate cultures.
Broth culture
An inoculation needle is used in the transfer of microorganisms from a broth culture by first employing a vortex mixer to ensure a uniform suspension of the microorganisms within the broth. Aseptic technique is then applied to the needle. Once the needle is flamed and sterilized the culture broth cap will be removed by the needle hand. The open end of the broth culture will be flamed to reduce risk of contamination and the creation of aerosols.
While maintaining a fixed position of the needle, the culture broth will be moved up the needle until the needle tip is submerged. During the withdrawal of the broth culture the needle and the needle hand should not move in order to prevent springing action. The transfer from broth to needle concludes with flaming the open end of the broth culture and the closing of the lid while keeping the needle hand immobile.
Slant culture
In slant culture transfer, the inoculation needle will be first treated with the aseptic technique by flaming. The slant culture cap is then removed and secured using the needle hand. Flaming the open end of the slant culture will prevent contamination and the formation of aerosols.
Transfer happens once the tip of the inoculation needle comes into contact with the agar surface of the slant culture. The inoculation needle should not move in the process. The agar slant culture will be moved up to the needle to prevent jostling of the needle. Once the transfer is complete from slant culture to needle, the open end of the culture will be treated with flame and the cap will be replaced.
Plate culture
An inoculation needle is used in the transfer of microbial organisms from plate culture to needle by first sterilizing the needle to prevent contaminants. The lid of the agar plate culture is then removed to allow the needle access to the microorganisms cultured on the agar plate. The lid is held hovering above the culture plate to prevent contamination from the surrounding environment.
The inoculation needle after incineration is cooled down on an uninoculated region of the agar plate culture. Too much heat will kill off the inoculum during the direct contact of a flamed inoculation needle. The inoculation needle is withdrawn from the agar culture after obtaining a small colony and the agar plate lid is then replaced.
Inoculation
Inoculation of the microorganisms will be done directly after the transfer from culture to inoculation needle. The inoculum is commonly inoculated to broth cultures, slant cultures, plate cultures, and stab cultures.
Broth culture
An inoculation needle is used in inoculating a sterile broth culture. Flaming the open end of the broth will keep it sterile. The broth will be moved up to the needle so that the needle tip is submerged while maintaining the needle's original position. Careful swirling of the needle can help the inoculation of the microorganism from the needle to the sterile broth.
The inoculated broth culture is then removed from the needle. Aseptic technique is applied to the open end of the broth culture to prevent contaminants, and the needle is flamed for sterilization.
Slant culture
An inoculation needle is used to inoculate a slant culture in a fish tail inoculation technique. After the microorganisms transfer from the original microbial culture to the inoculation needle the sterile slant culture is uncapped. The open end of the uncapped slant culture is then flamed. The slant will be positioned to move up the needle until the inoculation needle tip lightly come into contact with the base surface of the sterile media. The inoculation needle inoculates the sterile agar by the manipulation of the media so that the needle tip grazes the agar surface in a zigzag pattern. Aseptic technique is then applied to the withdrawn inoculation needle.
Plate culture
Inoculation of a plate culture is done through the streaking technique to make a streak plate. After lifting the lid so that it hovers above the sterile agar plate, the inoculation needle will be streaked across the plate in controlled directions. Microbial aerosols can be created from the hitting of the inoculation tip to the sides of the agar plate. The inoculation needle is then withdrawn from the inoculated agar plate culture and flamed.
Stab culture
An inoculation needle is an essential tool in inoculating a stab culture. A sterile stab culture cap is removed and the open end is flamed. The needle tip and its length is then pushed into the stab media and stopped once the needle tip reaches 0.5 inches away from the bottom of the stab media. The inoculation needle is withdrawn from the media in the same direction and path that it was pushed into the stab media to prevent the wobbling effect that may disturb the culture. The needle is sterilized by flaming.
See also
Inoculation loop
Streaking (microbiology)
Microbiological culture
Gallery
References
Laboratory equipment
Microbiology equipment | Inoculation needle | [
"Biology"
] | 1,553 | [
"Microbiology equipment"
] |
51,726,020 | https://en.wikipedia.org/wiki/NATO%20Software%20Engineering%20Conferences | The NATO Software Engineering Conferences were held in 1968 and 1969. The conferences were attended by international experts on computer software who aimed to define best practices for software development grounded in the application of engineering principles. The result of the conferences were two reports, one for the 1968 conference and the other for the 1969 conference, that outlined how software should be developed. The conferences played a major role in gaining general acceptance for the term software engineering.
Background
In the 1960s, the computer industry was experiencing rapid growth, leading to increasing complexity in software development. This period saw the emergence of what was later termed the "software crisis", characterized by projects that were over budget, overdue, and unreliable. To address these challenges, the NATO Science Committee convened two conferences to explore ways to improve software development practices by applying engineering principles.
1968 Conference in Garmisch
The first conference took place in Garmisch, Germany, from 7 to 11 October 1968. It was attended by 50 leading computer scientists and practitioners from 11 countries, including Edsger Dijkstra, Friedrich L. Bauer, Alan Perlis, and Peter Naur. The term "software engineering" was deliberately chosen as the conference title to provoke thought regarding the need for disciplined approaches in software development.
During the conference, participants discussed issues such as software reliability, project management, and the challenges of large-scale software systems. The concept of the "software crisis" was a central theme, highlighting the difficulties in producing high-quality software on time and within budget. The conference emphasized the importance of adopting engineering principles in software development to improve reliability and efficiency.
The conference resulted in a report edited by Peter Naur and Brian Randell, which compiled the discussions and recommendations made during the event. The editors faced the challenge of capturing the dynamic discussions and diverse viewpoints, ultimately producing a document that emphasized the need for formal methodologies and better project management in software development.
1969 Conference in Rome
Following the success of the first conference, a second conference was held in Rome, Italy, from 27 to 31 October 1969. The goal was to delve deeper into the technical aspects of software engineering. However, the atmosphere differed from the first conference, with less consensus among participants and a lack of clear direction.
Discussions at the Rome conference focused on software design techniques, methodologies, and tools. The conference highlighted the communication gap between different groups involved in software development, emphasizing the need for better collaboration. There was also a proposal to establish an international software engineering institute, but it did not gain sufficient support. Additionally, the conference brought to light the differing opinions on how software engineering should evolve, with debates over the balance between theoretical approaches and practical applications.
The report from the second conference was edited by John Buxton and Brian Randell. The editors faced challenges due to the lack of clear consensus among participants, making the compilation of the report more difficult than the previous year. Despite these difficulties, the report provided insights into the state of software engineering at the time and highlighted areas needing further research and development.
Impact and legacy
The NATO Software Engineering Conferences were instrumental in establishing software engineering as a recognized discipline. The conferences popularized the term "software engineering" and brought attention to the critical issues facing the software industry at the time.
The reports from these conferences influenced academia and industry, leading to the development of new methodologies, tools, and educational programs. They prompted further discussions on software reliability, project management, and the application of engineering principles to software development. The conferences are considered seminal events in the history of software engineering, setting the foundation for the discipline and inspiring future conferences and research in the field.
See also
Software crisis
Software engineering
History of software engineering
References
External links
Software Engineering: Report of a conference sponsored by the NATO Science Committee, 1968
Software Engineering Techniques: Report on a conference sponsored by the NATO Science Committee, 1969
History of software
Information technology organizations based in Europe
History of NATO
Software engineering conferences | NATO Software Engineering Conferences | [
"Technology",
"Engineering"
] | 783 | [
"Software engineering",
"Software engineering conferences",
"History of software",
"History of computing"
] |
51,726,771 | https://en.wikipedia.org/wiki/Paper-ruling%20machine | A paper-ruling machine is a device for ruling paper. In 1770, John Tetlow was awarded a patent for a "machine for ruling paper for music and other purposes." William Orville Hickok invented an "improved ruling machine" in the mid-19th century. As the device is designed for drawing lines on paper, it can produce tables and ruled paper.
The functionality of the machine is based on pens manufactured especially for the device. The pens have multiple tips side by side, and water-based ink is led into them along threads. It is possible to program stop-lines on the equipment by mounting pens on shafts equipped with cams that lower and raise them at predetermined points.
The spread of computerized accounting between the 1960s and 1980s significantly decreased the demand for accounting tables and ruled paper. Nowadays, their demand is primarily filled by using offset printing.
References
External links
Hickok paper-ruling machines, automatic paper feeders, ruling pens and inks, Catalog No. 89
Machines
History of printing | Paper-ruling machine | [
"Physics",
"Technology",
"Engineering"
] | 210 | [
"Physical systems",
"Machines",
"Mechanical engineering"
] |
51,727,952 | https://en.wikipedia.org/wiki/Anna%20L.%20Peterson | Anna L. Peterson (born 1963) is an American scholar of religious studies who is currently a professor in the Department of Religion at the University of Florida, where she has worked since 1993. Her research variously concerns religion in Latin America and ethics—including religious ethics, Christian ethics, environmental ethics, animal ethics and social ethics. She is the sole or co-author of seven monographs: Martyrdom and the Politics of Religion (State University of New York Press, 1997); Being Human (University of California Press, 2001); Seeds of the Kingdom (Oxford University Press, 2001); Everyday Ethics and Social Change (Columbia University Press, 2009); Being Animal (Columbia University Press, 2013); Works Righteousness (Oxford University Press, 2020); and Cats and Conservationists (2020, Purdue University Press).
Career
Peterson studied at Williams College (1981–1983) before going on to receive a religious studies BA from the University of California at Berkeley (1983–1985). She then studied at the University of Chicago Divinity School from 1986 to 1991. She received an MA in 1987, and a PhD in Ethics and Society in 1991. Her doctoral thesis was supervised by Robin Lovin. She became an assistant professor in religious studies at St. Norbert College in 1991, where she remained until 1993, when she took up the position of assistant professor at the University of Florida Department of Religion. In 1997, her Martyrdom and the Politics of Religion was published with State University of New York Press. The book blends theology, social history and ethnographic anthropology to explore ideas of Catholic martyrdom in the Salvadoran Civil War. She became an associate professor in 1998, and spent two years as a visiting fellow at the Wesleyan University Department of Religion. 2001 saw the publication of her Being Human, a book about environmental ethics from the perspective of religious ethics. In 2002, she became a full professor.
Peterson has published a number of books while a full professor at Florida. Seeds of the Kingdom, a comparative study of United States Amish farming communities and of El Salvador's refugee communities, appeared in 2005. Both groups examined, Peterson argues, attempt to build utopian Christian communities. Everyday Ethics and Social Change was published in 2009. In this book, Peterson argues that humans should extend the ethical values dominant in interpersonal relationships, such as love, to differently structure currently instrumental societal and political relationships. 2011 saw the publication of Working Toward Sustainability: Ethical Decision-Making in a Technological World, a textbook which Peterson co-authored with Charles J. Kibert, Martha C. Monroe, Richard R. Plate and Leslie Paul Thiele. In 2013's Being Animal, Peterson critiques the separation of environmental and animal ethics. Though frequently thought irreconcilable, Peterson argues that the separation can be blamed on a weak understanding of nature, humans, and animals, as well as the relationships between them.
Selected bibliography
In addition to her books, Peterson has written over twenty articles published in peer reviewed academic journals and scholarly edited collections, as well as various review articles, book reviews and encyclopedia articles.
Peterson, Anna L. (1997). Martyrdom and the Politics of Religion: Progressive Catholocisim in El Salvador's Civil War. Albany, New York: State University of New York Press.
Peyerson, Anna L., Manuel A. Vásquez, and Philip J. Williams, eds. (2001). Christianity, Social Change, and Globalization in the Americas. New Brunswick, New Jersey: Rutgers University Press.
Peterson, Anna L. (2001). Being Human: Ethics, Environment, and Our Place in the World. Berkeley, California: University of California Press.
Peterson, Anna L. (2005). Seeds of the Kingdom: Utopian Communities in the Americas. Oxford: Oxford University Press.
Peterson, Anna L., and Manuel A. Vásquez, eds. (2008). Latin American Religions: Histories and Documents in Context. New York: New York University Press.
Peterson, Anna L. (2009). Everyday Ethics and Social Change: The Education of Desire. New York: Columbia University Press.
Kibert, Charles J., Martha C. Monroe, Anna L. Peterson, Richard R. Plate and Leslie Paul Thiele (2012). Working Toward Sustainability: Ethical Decision Making in a Technological World. Hoboken, New Jersey: John Wiley and Sons.
Peterson, Anna L. (2013). Being Animal: Beasts and Boundaries in Nature Ethics. New York: Columbia University Press.
LeVasseur, Todd, and Anna Peterson, eds. (2016). Religion and Ecological Crisis: The "Lynn White Thesis" at Fifty. New York: Routledge.
Peterson, Anna L. (2020). Works Righteousness: Material Practice in Ethical Theory. Oxford: Oxford University Press.
Wald, Dara M., and Anna L. Peterson (2020). Cats and Conservationists: The Debate over Who Owns the Outdoors. West Lafayette: Purdue University Press.
References
External links
Anna L. Peterson at the University of Florida
1963 births
Living people
Religious studies scholars
American ethicists
Animal ethicists
Environmental ethicists
University of Florida faculty
Williams College alumni
University of California, Berkeley alumni
University of Chicago Divinity School alumni
Women and religion
Philosophers from California
Philosophers from Florida | Anna L. Peterson | [
"Environmental_science"
] | 1,080 | [
"Environmental ethicists",
"Environmental ethics"
] |
51,728,137 | https://en.wikipedia.org/wiki/Monotone%20matrix | A real square matrix is monotone (in the sense of Collatz) if for all real vectors , implies , where is the element-wise order on .
Properties
A monotone matrix is nonsingular.
Proof: Let be a monotone matrix and assume there exists with . Then, by monotonicity, and , and hence .
Let be a real square matrix. is monotone if and only if .
Proof: Suppose is monotone. Denote by the -th column of . Then, is the -th standard basis vector, and hence by monotonicity. For the reverse direction, suppose admits an inverse such that . Then, if , , and hence is monotone.
Examples
The matrix is monotone, with inverse .
In fact, this matrix is an M-matrix (i.e., a monotone L-matrix).
Note, however, that not all monotone matrices are M-matrices. An example is , whose inverse is .
See also
M-matrix
Weakly chained diagonally dominant matrix
References
Matrices | Monotone matrix | [
"Mathematics"
] | 211 | [
"Matrices (mathematics)",
"Mathematical objects"
] |
51,728,633 | https://en.wikipedia.org/wiki/Nitrolic%20acid | Nitrolic acids are organic compounds with the functional group RC(NO2)=NOH. They are prepared by the reaction of nitroalkanes with base and nitrite sources:
RCH2NO2 + HNO2 → RC(NO2)=NOH + H2O
The conversion was first demonstrated by Victor Meyer using nitroethane. The reaction proceeds via the intermediacy of the nitronate anion.
Occurrence
Most nitrolic acids are laboratory curiosities. One exception is the compound HO2C(CH2)4C(NO2)=NOH, which is produced by the oxidation of cyclohexanone with nitric acid. This species decomposes to adipic acid and nitrous oxide:
HO2C(CH2)4C(NO2)=NOH → HO2C(CH2)4CO2H + N2O
This conversion is thought to be the largest anthropogenic route to N2O, which, on a molecule-to-molecule basis, has 298 times the atmospheric heat-trapping ability of carbon dioxide. Adipic acid is a precursor to many nylon polymers. In the end, nitrous oxide is produced in about one to one mole ratio to the adipic acid.
References
Functional groups
Organonitrogen compounds | Nitrolic acid | [
"Chemistry"
] | 277 | [
"Organic compounds",
"Organonitrogen compounds",
"Functional groups"
] |
51,729,450 | https://en.wikipedia.org/wiki/Snap%20Inc. | Snap Inc. is an American technology company, founded on September 16, 2011, by Evan Spiegel, Bobby Murphy, and Reggie Brown based in Santa Monica, California. The company developed and maintains technological products and services, namely Snapchat, Spectacles, and Bitmoji. The company was named Snapchat Inc. at its inception, but it was rebranded Snap Inc. on September 24, 2016, in order to include the Spectacles product under the company name. Snap is co-owned by Tencent (which holds a 45.43% stake) and NBCUniversal, a subsidiary of Comcast (whose stake is undisclosed).
History
The company was founded on September 16, 2011, by Evan Spiegel and Bobby Murphy upon the relaunch of the photo sharing app Picaboo as Snapchat. On December 31, 2013, the application was hacked and 4.6 million usernames and phone numbers were leaked to the Internet.
By January 2014, the company had refused offers of acquisition, including overtures from Mark Zuckerberg, with Spiegel commenting that "trading that for some short-term gain isn’t very interesting."
In May 2014, the company acquired the software company AddLive to provide needed technology to create a new video chat feature. In that same month, it settled U.S. Federal Trade Commission (FTC) charges over its having misled users regarding its collection of their address book data and transmission of their locations (without notice or consent), and regarding its claim that user messages disappeared after their expiration (rather than remaining accessible, as they had). In December, the company acquired Vergence Labs for $15 million in cash and stock, who were the developers of Epiphany Eyewear, and the mobile app Scan for $50 million, which was revealed during the 2014 Sony Pictures hack.
In May 2015, the company moved from its original headquarters to a 47,000 ft2 (4,366 m2) office complex near Venice Beach and signed a 10-year lease. They were one of the first prominent online platforms to establish themselves there, alongside others such as Whisper and Tinder, giving Venice the new title of "Silicon Beach." In February 2017, two weeks before the company's IPO, The New York Times published a feature about Snap's role in turning the area into a technology hub, noting that Snap, with a total of 1,900 employees, had "already changed the face of Venice."
In September 2015, Snapchat acquired Looksery to develop Lenses for its mobile app, a feature based on Looksery's facial recognition software.
In March, July, and August 2016, the company acquired Bitstrips for $100 million, Obvious Engineering, the developers of Seene, for an undisclosed amount and Vurb for $100 million. Vurb formerly developed the eponymous mobile search engine. The Vurb card-based engine removed the need to switch through multiple other applications on the device to perform a task.
In September 2016, the company officially named itself Snap Inc., and unveiled smartglasses known as Spectacles. In November 2016, the company filed documents for an initial public offering (IPO) with an estimated market value of $25–35 billion. In December 2016, the company opened research and development in Shenzhen and acquired advertising and technology company Flite and Israel-based augmented reality startup Cimagine Media for $30–40 million. A partnership issued in December 2016 with Turner Broadcasting System will allow integration of Turner properties on Snapchat, while cooperating with Snap Inc. to develop original content.
In January 2017, the company announced that it had established an international headquarters in Soho, London. In early February 2017, the company confirmed their plans for an IPO in 2017 and its expectation to raise $3 billion. In early March 2017, the company went public under the trading symbol SNAP, and raised almost $30 billion in market capitalization on the first day of trading.
In late May 2017, the company acquired the location sharing app Zenly in a cash and stock deal. The Zenly app will remain functional, but its concepts were incorporated into a Snapchat feature added in June 2017.
In August 2017, Business Insider reported that Google discussed an offer to buy the company for $30 billion in early 2016.
In October 2017, the company announced that it had formed a joint venture with NBCUniversal to produce content for Snap's platforms, and that it had signed Duplass Brothers Productions as its first partner.
In November 2017, Tencent acquired a 12% non-voting minority equity stake of the company in the open market.
On October 26, 2018, at TwitchCon, Snap launched a new desktop application for macOS and Windows known as Snap Camera. It allows users to utilize Snapchat filters via PC webcams in video chat and live streaming services such as Skype, Twitch, YouTube, and Zoom. Snap also announced additional integration with Twitch.
In August 2022, The Verge reported that Snap would be laying off 20% of its 6,400-person workforce. The layoffs primarily impacted the company's hardware division and the developer products including the separately run Zenly.
On 5 February 2024, Snap Inc. announced it would lay off 10% of its global workforce, approximately 500 employees, partly to enhance in-person collaboration, marking another significant reduction following a 20% staff cut in 2022.
On September 12, 2024, Snap appointed Yahoo CEO Jim Lanzone to its board of directors.
Products
The company develops and maintains the image messaging and multimedia mobile app Snapchat, as well as the Snapchat's Augmented Reality (AR) ad lens. The function was launched in September 2015. Specifically, the AR ad lens is one of the unique features of Snapchat, which allows advertisers to attract their target audience with various innovative lenses. Users can also use these lenses to change their faces, appearance, and even surroundings based on their preferences, and share those visual images or videos within their social networks. In addition, the company also develops and manufactures the wearable camera called Spectacles, a pair of smartglasses that connect to the user's Snapchat account and records videos in a circular video format adjustable in any orientation. On February 20, 2017, Snap Spectacles became available for purchase online. The company sold only 220,000 pairs of Snap Spectacles V1. The company developed and launched Spectacles V2 in April 2018 in the U.S., Canada, U.K. and France; and 13 more European countries in May 2018. On April 28, 2022, the company announced a mini drone called Pixy. Later that year in August, it was reported that future development of Pixy would be discontinued, while continuing to sell the current iteration of the drone.
Funding and shares
Snapchat app raised $485,000 in its seed round and an undisclosed amount of bridge funding from Lightspeed Venture Partners. By February 2013, Snapchat confirmed a $13.5 million Series A funding round led by Benchmark, which valued the company at between $60 million and $70 million. In June 2013, Snapchat raised $60 million in a Series B funding round led by venture capital firm Institutional Venture Partners. The firm also appointed a new high-profile board member, Michael Lynton of Sony's American division. By mid-July 2013, a media report valued the company at $860 million. On November 14, 2013, The Wall Street Journal reported that Facebook offered to acquire Snapchat for $3 billion, but Spiegel declined the cash offer. Tech writer Om Malik then claimed on November 15, 2013, that Google had offered $4 billion, but Spiegel again declined. On December 11, 2013, Snapchat confirmed $50 million in Series C funding from Coatue Management. Beyond 2014, the company had achieved a $10–$20 billion valuation, depending on the source, raising $100 million in Series D funding led by KPCB and $485 million in a Series E round led by Alibaba Group. Investors included General Catalyst, Kingdom Holding Company, SV Angel, Yahoo!, and Tencent. According to reports in May 2016, the company's estimated worth was said to be approaching $22.7 billion in the event of a new Series F round of investment of $1.8 billion from Spark Capital, General Atlantic, Sequoia Capital, T. Rowe Price, Meritech Capital Partners, Dragoneer Investment Group and others, led by Fidelity Investments. Later, the company got an additional $200 million in the following Series FP round. Further reports in 2016 suggested that funding was almost at $3 billion and that Snapchat was targeting yearly revenues of a billion dollars.
Google reportedly offered Snap $30 billion in 2016 for acquisition, which Snap turned down.
2017 initial public offering
In January 2017, The Wall Street Journal reported that "people familiar with the matter" stated that Snap Inc. would share 2.5% of the money raised in an upcoming initial public offering (IPO) with the banks managing the IPO. It also reported that after the predicted March 2017 IPO, the two Snap co-founders would hold over "70% of the voting power" in the company and own around 45% of the total stock. On January 29, 2017, it was reported that the Snap Inc. IPO would likely take place on the New York Stock Exchange. As both the NYSE and Nasdaq had been "aggressively courting the listing for more than a year," the Wall Street Journal called it "a big competitive victory for the Big Board." Snap's IPO was estimated to value the company at between $20 billion and $25 billion, the largest IPO on a US exchange since Alibaba debuted in 2014 at a value of $168 billion. Beyond the two founders, the two biggest shareholders for the planned early 2017 Snap IPO were Benchmark and Lightspeed Venture Partners, both prior investors and venture-capital firms from Silicon Valley. They held a combined stake of about 20%. On March 1, 2017, it was reported that Snap Inc. "values itself at nearly $24B with its IPO pricing." Snap Inc.'s stock started trading on March 2, 2017, under the symbol SNAP, on the New York Stock Exchange.
When Snap reported earnings for the first time in May 2017, they reported a $2.2 billion quarterly loss, and the stock fell more than 20%, erasing most of the gains since the IPO. Its market capitalization reached $100 billion for the first time on 22 February 2021.
In February 2024 stock fell 30% after earnings with disappointing profit guidance. Market capitalisation as of 3 March 2024 was $18B, below 2017 IPO level.
Controversy
Reggie Brown lawsuit
In February 2013, Reggie Brown sued Evan Spiegel and Bobby Murphy. Early investors were also eventually named in the lawsuit. Brown said that he had once been the chief marketing officer for the initial selfie app used to launch Snapchat, offering evidence of contacts with publications such as Cosmopolitan. He also claimed that he had come up with the original concept, which he had ultimately called Picaboo, and that he had created the mascot logo for the product while working with Spiegel to promote and market the idea. Originally titled "Toyopa Group, LLC," Brown said that he had named the newly formed company as well. Brown's lawyers offered documentation of a collaboration with Spiegel and Murphy, which included the filing of an original patent by the three Stanford classmates, but Snapchat described the lawsuit as meritless and called Brown's tactics a "shakedown". During April's depositions, Brown testified that he had believed he was an equal partner, and that he had agreed to share costs and profits. Spiegel instead described Brown as an unpaid intern who had been given an opportunity to earn valuable experience, and although Murphy claimed that he had not fully understood what Brown's role was supposed to have been, he too characterized Brown's involvement as having been that of an internship. Months later, Spiegel dismissed the lawsuit as an example of opportunists who seek out rapidly successful companies in an attempt "to also profit from the hard work of others."
On 9 September 2014, the company announced that they had settled the lawsuit for an initially undisclosed amount. The settlement amount was revealed on 2 February, 2017, in Snap's SEC public filing to be $157.5 million. As part of the settlement, they credited Brown with the conceptual idea for Snapchat.
The press release published by Snapchat's communication department quoted Spiegel:"We are pleased that we have been able to resolve this matter in a manner that is satisfactory to Mr. Brown and the Company. We acknowledge Reggie's contribution to the creation of Snapchat and appreciate his work in getting the application off the ground."
FTC settlement
The Federal Trade Commission alleged that the company had exaggerated to the public the degree to which mobile app images and photos could actually be made to disappear. Following a settlement in 2014, Snapchat was not fined, but the app service agreed to have its claims and policies monitored by an independent party for a period of 20 years.
2018 redesign
The redesign of the Snapchat app in early 2018 made changes for which many users were not happy. Around 1.2 million people petitioned Snap, Inc. to roll back the redesign. Snap, Inc's reply makes no concessions, other than noting, "We completely understand the new Snapchat has felt uncomfortable for many."
Due to the redesign and other market factors in 2018, such as the growth of Instagram Stories and WhatsApp Status, Daily Active Users (DAU) of the app only rose 2% from Q4 2017. Snap, Inc. stock fell more than 15% in after-hours trading following the earnings report release. Growth of daily active users slowed in Q1 2018, and the growth rate for Q2 2018 was "planned to decelerate rapidly from Q1 levels." Snap, Inc. has commented on the redesign, saying, "We have also started to realise some of the positive benefits [of the redesign], including increased new user retention for older users." Some publishers feel the turn towards the older demographic spells the end for the app.
Data storage
In a December 2020 announcement, Google Cloud confirmed the development of the memorandum of understanding (MoU) it signed with Saudi Aramco. The update stated the possibility of exploring options to establish cloud services in Saudi, where it confirmed storing Snapchat data. The decision was contested by Access Now, a non-profit organization, and CIPPIC, a Canadian public interest technology law clinic. The firms objected to Google's decision of choosing Saudi Arabia as its new Google Cloud region overlooking an alarming record of human rights abuse and longstanding surveillance accusations. The firms claimed that placing the personal information of millions of Snapchat users there would put it under the jurisdiction of the government of Saudi Arabia, jeopardizing the security of the data.
California civil rights lawsuit
In June 2024, Snap paid $15 million to settle a lawsuit brought by the California Civil Rights Department alleging that the company discriminated against female employees with respect to pay and promotions, failed to prevent workplace sexual harassment, and retaliated against women who complained.
References
External links
2011 establishments in California
2017 initial public offerings
Companies based in Los Angeles
Companies listed on the New York Stock Exchange
Holding companies established in 2016
Mass media companies established in 2011
Internet properties established in 2011
Mass media companies of the United States
Social media companies of the United States
Technology companies based in Greater Los Angeles
Technology companies established in 2011
Venice, Los Angeles | Snap Inc. | [
"Technology"
] | 3,249 | [
"Instant messaging",
"Snap Inc."
] |
51,729,682 | https://en.wikipedia.org/wiki/Nine%20Choucroun | Nine Choucroun, born Fortunée Schecroun (October 6, 1896 – December 10, 1978) was a French biochemist. She was director of research at the Institut de biologie physico-chimique in Paris. She developed, inter alia, the electrophoresis.
Collaborator of Jean Perrin, she became his partner after the death of his wife Henriette in 1938. She managed to board the ocean liner Massilia that allowed them to escape with part of the French government in June 1940 to Casablanca, boarding later the SS Excambion in December 1941, arriving in New York City on December 23, 1941.
Nine Choucroun Prize
Nine Choucroun wanted to encourage young researchers to research in the area, very wide, from the physico-chemical biology. The Nine Choucroun Prize, annual, was created in December 1980 by her heirs. The value of the prize until 2008 was €5,000 and has been raised to €8,000 in 2011. This prize, awarded under the auspices of the physico-chemical Biology Institute and the Edmond de Rothschild Foundation, is aimed at young researchers working in the field of physico-chemical biology.
External links
Prix Nine Choucroun
References
Micheline Charpentier-Morize, Perrin, savant et homme politique, Paris, Belin, 1997
Pieds-noirs
French biochemists
Women biochemists
20th-century American women scientists
1896 births
1978 deaths
Emigrants from French Algeria to France
French emigrants to the United States
20th-century American biochemists
20th-century French women scientists
People from Oran | Nine Choucroun | [
"Chemistry"
] | 340 | [
"Biochemists",
"Women biochemists"
] |
51,730,409 | https://en.wikipedia.org/wiki/Tetramethylurea | Tetramethylurea is the organic compound with the formula (Me2N)2CO. It is a substituted urea. This colorless liquid is used as an aprotic-polar solvent, especially for aromatic compounds and is used e. g. for Grignard reagents. Tetramethylurea is a colorless liquid with mild aromatic odor. Unusual for an urea is the liquid state of tetramethylurea in a range of > 170 °C.
Production
It is obtained by the reaction of dimethylamine with phosgene in the presence of sodium hydroxide solution. A closely related method combines dimethylcarbamoyl chloride with excess dimethylamine. This reactions is highly exothermic. The removal of the resulting dimethylamine hydrochloride requires some effort.
The reaction of diphenylcarbonate with dimethylamine in an autoclave is also effective.
Tetramethylurea is formed upon the oxygenation of tetrakis(dimethylamino)ethylene (TDAE).
Tetramethylurea is also a common by-product formed in amide bond forming reactions and peptide synthesis with uronium and guanadinium-based reagents such as HATU, HBTU ad TCFH.
Applications
Tetramethylurea is miscible with a variety of organic compounds, including acids such as acetic acid or bases such as pyridine and an excellent solvent for organic substances such as ε-caprolactam and benzoic acid. It dissolves even some inorganic salts such as silver nitrate and sodium iodide. Tetramethylurea is often used in place of hexamethylphosphoramide (HMPT), which is suspected of being carcinogenic.
Tetramethylurea is suitable as a reaction medium for the polymerization of aromatic diacid chlorides (such as isophthalic acid) and aromatic diamines (such as 1,3-diaminobenzene (m-phenylenediamine)) to aramids such as poly (m-phenylene isophthalamide) (Nomex®)
The polymerization of 4-amino benzoic acid chloride hydrochloride in tetramethylurea provides isotropic viscous solutions of poly(p-benzamide) (PPB), which can be directly spun into fibers.
In a tetramethylurea-LiCl mixture stable isotropic solutions can be obtained up to a PPB polymer concentration of 14%.
Tetramethylurea also dissolves cellulose ester and swells other polymers such as polycarbonates, polyvinyl chloride or aliphatic polyamides, usually at elevated temperature.
Strong and hindered non-nucleophilic guanidine bases are accessible from tetramethylurea in a simple manner, which are in contrast to the fused amidine bases DBN or DBU not alkylated.
A modification of the Koenigs-Knorr reaction for building glycosides from 2,3,4,6-tetra-O-acetyl-α-D-glucopyranosyl bromide (acetobromoglucose) originates from S. Hanessian who used the silver salt silver trifluoromethanesulfonate (TfOAg) and as a proton acceptor tetramethylurea. This process variant is characterized by a simplified process control, high anomeric purity and high yields of the products. If the reaction is carried out with acetobromoglucose and silver triflate/tetramethylurea at room temperature, then tetramethylurea reacts not only as a base, but also with the glycosyl to form a good isolable uroniumtriflates in 56% yield.
Safety
The acute toxicity of tetramethylurea is moderate. However, it is embryotoxic and teratogenic towards several animal species. Tetramethylurea was demonstrated to not exhibit dermal corrosion but did exhibit dermal and eye irritation. The sensitization potential of tetramethylurea was shown to be low compared (non-sensitizing at 1% in LLNA testing according to OECD 429).
References
Ureas
Amide solvents | Tetramethylurea | [
"Chemistry"
] | 933 | [
"Organic compounds",
"Ureas"
] |
51,735,144 | https://en.wikipedia.org/wiki/Amanita%20umbrinolutea | Amanita umbrinolutea, also known as the umber-zoned ringless amanita, is a species of the genus Amanita.
Description
The cap of A. umbrinolutea is usually free of volval remnants, wide, at first conico-paraboloid, then somewhat campanulate to convex and finally planar, umbonate, with a strongly striate margin (occupying around 25–35% of the cap's radius). The cap is often dark in the center, then pale, then dark over the inner edges of the lamellae and on the ridges between the marginal striations; it can at other times be pallid in the center, but strongly zonate; the pigmentation intensity varies, with the center ranging from umber to grayish umber-brown to beige or pale grayish brown. The gills are free, crowded, off-white to sordid pale cream in mass, and up to broad; the short gills are truncate, vary in length, and are scattered and unevenly distributed.
The stem is × 6–11 mm, pale cream to pale beige or isabella color or pale grayish brown, with a faint appressed zigzag girdles of fibrils, with a fleshy membranous sack-like volva at the base. The high volva is attached to the bottom 5 mm or so of the stipe. The spores measure 10.5–13.4 × 9.5–12.5 (1.05–1.34 x 0.95–1.25 cm) μm and are subglobose (infrequently either globose or broadly ellipsoid) and inamyloid. Clamps are absent from the bases of basidia.
Distribution and habitat
A. umbrinolutea is widely distributed in Europe, with its range extending eastward at least to around northwestern Pakistan and North India. Known specimens have examined have all been found in association with conifers (including pine and spruce).
See also
List of Amanita species
References
Umbrinolutea
Fungus species | Amanita umbrinolutea | [
"Biology"
] | 448 | [
"Fungi",
"Fungus species"
] |
51,735,357 | https://en.wikipedia.org/wiki/Hertwig%20rule | Hertwig's rule, or the long axis rule states that a cell divides along its long axis. Introduced by the German zoologist Oscar Hertwig in 1884, the rule emphasizes the cell shape as a default mechanism of spindle apparatus orientation. Hertwig's rule predicts cell division orientation, which is important for tissue architecture, cell fate and morphogenesis.
Discovery
Hertwig's experiments studied the orientation of frog egg divisions. The frog egg has a round shape and the first division occurs in a random orientation. Hertwig compressed the egg between two parallel plates. The compression forced the egg to change its shape from round to elongated. Hertwig noticed that elongated egg divides not randomly, but orthogonally to its long axis. The new daughter cells were formed along the longest axis of the cell. This observation thus became known as 'Hertwig's rule' or 'long axis rule'.
Confirmation and mechanism
Recent studies in animal and plant systems support the 'long axis rule'. The studied systems include the mouse embryo, Drosophila epithelium, Xenopus blastomeres (Strauss 2006), MDCK cell monolayers and plants (Gibson et al., 2011). The mechanism of the 'long axis rule' relies on interphase cell long axis sensing. However, during division many animal cell types undergo cell rounding, causing the long axis to disappear as the cell becomes round. It is at this rounding stage that the decision on the orientation of the cell division is made by the spindle apparatus. The spindle apparatus rotates in the round cell and after several minutes the spindle position is stabilised preferentially along the interphase cell long axis. The cell then divides along the spindle apparatus orientation. The first insights into how cells could remember their long axis came from studies on the Drosophila epithelium. The study indicated the participation of tricellular junctions (TCJs) in determining the spindle orientation. TCJs localized at the regions where three or more cells meet. As cells round up during mitosis, TCJs serve as spatial landmarks. The orientation of TCJs remains stable, independent of the shape changes associated with cell rounding. The positions of TCJs encode information about interphase cell shape anisotropy to orient division in the rounded mitotic cell. However this study is limited to only one type of epithelia in Drosophila melanogaster and has not been shown to be true in other epithelial types.
Mechanobiology
It has been shown that mechanical force can cause cells to divide against their long axis and instead with the direction of mechanical stretch in MDCK monolayers.
Importance
Cell divisions along 'long axis' are proposed to be implicated in the morphogenesis, tissue response to stresses and tissue architecture.
Division along the long cell axis reduces global tissue stress more rapidly than random divisions or divisions along the axis of mechanical stress. Long-axis division contributes to the formation of isotropic cell shapes within the monolayer.
References
Cell biology
Cell anatomy
Cell communication
Cell signaling
Cell cycle
Cellular processes
Developmental biology
Morphology (biology) | Hertwig rule | [
"Biology"
] | 643 | [
"Cell communication",
"Behavior",
"Cell biology",
"Developmental biology",
"Reproduction",
"Morphology (biology)",
"Cellular processes",
"Cell cycle"
] |
74,566,544 | https://en.wikipedia.org/wiki/Maxeon%20Solar%20Technologies | Maxeon Solar Technologies, Ltd. is a Singapore-based company that designs and manufactures photovoltaic panels. The company was previously a division of the American company SunPower. Maxeon was spun off from SunPower in August 2020. Maxeon was the primary provider of solar panels for SunPower through March 2024. Beyond the United States, Maxeon has sales operations in more than 100 countries and has the rights to use the SunPower brand in countries outside the United States.
History
When SunPower spun-off Maxeon in August 2020, the Tianjin Zhonghuan Semiconductor Company invested US$298 million for a 24% interest in Maxeon. Chinese technology company TCL later purchased Tianjin Zhonghuan Semiconductor, becoming a major investor in Maxeon. SunPower investor TotalEnergies also kept a significant ownership stake in Maxeon.
In March 2024, Maxeon Solar filed a patent infringement lawsuit against Canadian Solar. The alleged infringement was linked to Maxeon's TOPCon solar cell technology.
Products
Its products are known for being more expensive, but producing energy more efficiently than competing products. Maxeon panels are often used when there is a limited amount of space for the panels, such as on rooftops.
Ordinarily, the electrical contacts are on the front of a solar panel, facing the sun. The front of Maxeon's panels channel the light to electrical contacts on the back of the panel, reducing the amount of sunlight that is reflected rather than turned into energy. Hence, Maxeon panels are sought for efficiency and aesthetic reasons.
Notes
References
External links
Photovoltaics manufacturers
Energy companies established in 2020
Companies listed on the Nasdaq
Companies of Singapore | Maxeon Solar Technologies | [
"Engineering"
] | 340 | [
"Photovoltaics manufacturers",
"Engineering companies"
] |
74,566,652 | https://en.wikipedia.org/wiki/Rosettozymales | The Rosettozymales are an order of fungi in the class Microbotryomycetes. The order contains a single family, the Rosettozymaceae, which in turn contains a single genus, Rosettozyma. The order comprises fungi that are currently only known from their yeast states, isolated from plant leaves in China. Budding cells in yeast colonies always form rosette-like clusters, hence the name of the order.
References
Basidiomycota orders
Monotypic fungus orders
Yeasts
Pucciniomycotina | Rosettozymales | [
"Biology"
] | 112 | [
"Yeasts",
"Fungi"
] |
74,567,391 | https://en.wikipedia.org/wiki/Volyn%20biota | The Volyn biota are fossilized microorganisms found in rock samples from miarolitic cavities of igneous rocks collected in Zhytomyr Oblast, Ukraine. It is within the historical region of Volyn, hence the name of the find. Exceptionally well-preserved, they were dated to 1.5 Ga, within the "Boring Billion" period of the Proterozoic geological eon.
History of the discovery
The samples of Volyn biota were found in samples from miarolitic pegmatites ("chamber pegmatites") collected from the of the Ukrainian Shield. They were described as early as in 1987, but interpreted as abiogenic formations. In 2000, these formations were reinterpreted as the fossilized cyanobacteria from geyser-type deposits. Until very recently the origin of the Korosten pegmatites was not fully understood, but they were dated to 1.8-1.7 Ga.
Franz et al. (2022, 2023), investigating newly recovered samples they date to 1.5 Ga, described the morphology and the internal structure of Volyn biota and reported the presence of different types of filaments, of varying diameters, shapes and branching in the studied organisms, and provided evidence of the presence of fungi-like organisms and Precambrian continental deep biosphere. Some fossils give evidence of sessility, while others of free-living lifestyle.
Usually Precambrian fossils are not well preserved, but the Volyn biota had exceptional conditions for fossilization in cavities with silicon tetrafluoride-rich fluids. The cavities also preserved them from further diagenetic-metamorphic overprint.
Volyn biota is an additional support of the claim that filamentous fossils dated to 2.4 Ga from the Ongeluk Formation (Griqualand West, South Africa) were also fungi-like organisms.
See also
References
Fossils of Ukraine
Ecosystems
Biological systems
Zhytomyr Oblast
Volhynia
Proterozoic life
Lithophiles
Mesoproterozoic
Precambrian paleobiotas | Volyn biota | [
"Biology"
] | 442 | [
"Symbiosis",
"Prehistoric biotas",
"Precambrian paleobiotas",
"Ecosystems",
"nan"
] |
74,567,901 | https://en.wikipedia.org/wiki/Doron%20Levy | Doron Levy is a mathematician, scientist, magician, and academic. He is a Professor and chair at the Department of Mathematics at the University of Maryland, College Park. He is also the Director of the Brin Mathematics Research Center.
Levy's research encompasses the field of numerical analysis, applied nonlinear partial differential equations, and biology and medical applications, particularly focusing on analyzing cancer dynamics, immunology, and cell motility. He has written more than 100 peer-reviewed articles. He is the recipient of the National Science Foundation Career Award.
Levy is a Fellow of the John Simon Guggenheim Memorial Foundation He is an Editorial Board Member of the Bulletin of Mathematical Biology, Discrete and Continuous Dynamics Systems Series B, Le Matematiche, Acta Applicandae Mathematicae, Frontiers in Systems Biology, Cancer Research, Applied Mathematics Modelling, PLoS One, and Differential Equations and Dynamical Systems. He is the Editor-in-Chief at ImmunoInformatics.
Education
Levy earned his Baccalaureate degree in Mathematics and Physics in 1991 and completed a master's degree in Applied Mathematics in 1994 from Tel Aviv University. His Master's thesis was titled "From Semi-Discrete to Fully-Discrete: The Stability of Runge-Kutta Schemes by the Energy Method". In 1997, he received a Ph.D. in Applied Mathematics under the guidance of Eitan Tadmor, with a thesis on "Topics in Approximate Methods for Non-Linear Partial Differential Equations." Afterward, he held several post-doctorate fellowships at Laboratoire d'Analyse Numerique (University of Paris 6), École normale supérieure (Paris), University of California, Berkeley, and the Lawrence Berkeley National Laboratory.
Career
Following his post-doctoral fellowship at Berkeley in 2000, Levy joined the Department of Mathematics at Stanford University as an assistant professor. In 2007, he was appointed as associate professor of mathematics and a member of the Center for Scientific Computation and Mathematical Modeling at the University of Maryland, College Park. In 2014, he became a Pauli Fellow at the Wolfgang Pauli Institute of the University of Vienna in Austria. Since 2011, he has been a professor at the Department of Mathematics & Center for Scientific Computation and Mathematical Modeling of the University of Maryland, College Park.
Levy served as a Member of the Board of Governors of the Institute for Mathematics and Its Applications (IMA) at the University of Minnesota in 2018 for one year, and a Member of the Board of Directors of the Society for Mathematical Biology from 2018 to 2022. Since 2022, he has been serving as the Founding Director of the Brin Mathematics Research Center at the University of Maryland, College Park.
As of 2020, Levy has been a chair at the Department of Mathematics and the Director of the Center for Scientific Computation and Mathematical Modeling of the University of Maryland, College Park.
Research
Levy's research is focused on mathematical equations and biomedical applications of mathematics with a particular interest in cancer dynamics, drug resistance, drug delivery, immunology, imaging, and cell motility.
Numerical analysis
During his early research career, Levy worked on developing and analyzing high-order numerical methods for approximating solutions to hyperbolic conservation law and related equations. He developed novel methods for approximating solutions to nonlinear partial differential equations including Euler equations, Navier-Stokes equations, Hamilton-Jacobi equations, nonlinear dispersive equations. Some of the approximation methods he developed used Weighted Essentially Non-Oscillatory (WENO) schemes. He developed a third-order central scheme for approximating solutions of multidimensional hyperbolic conservation laws and 2D conservation laws using compact central WENO reconstructions. In a series of works with Steve Bryson, he proposed new high-order central schemes for approximating solutions of multidimensional Hamilton-Jacobi equations.
Cancer dynamics and the immune system
Levy contributed to cancer dynamics by formulating a set of computational and mathematical tools designed for specific types of cancer. He discussed the need for mathematical models to understand the complexity of breast and ovarian cancers and proposed a model to explain the failure of transvaginal ultrasound-based screening in detecting low-volume high-grade serous ovarian cancer. In a collaborative study, he investigated the effects of regulatory T cell switching the immune response and identified a biologically testable range for the switching parameter. Furthermore, he presented mathematical models for studying cancer cell growth dynamics in response to antimitotic drug treatment in vitro, to understand the immunogenic effects of LSD1 inhibition on tumor growth and T cell dynamics, and for the interaction between immune response and cancer cells in chronic myelogenous leukemia and analyzes the stability of steady states.
Levy analyzed cancer's immune response mechanisms, particularly in chronic myeloid leukemia, providing insights into the role of the immune response and drug therapy in controlling the disease. He also demonstrated that the autologous immune system may play a role in the BCR-ABL transcript variations observed in chronic phase chronic myelogenous leukemia patients on imatinib therapy. Considering the problem of drug resistance in cancer he suggested a simple compartmental system of ordinary differential equations to model it and stated that drug resistance depends on the turnover rate of cancer cells. Additionally, he extended a model of drug resistance in solid tumors to explore the dynamics of resistance levels and the emergence of heterogeneous tumors in response to chemotherapy. Conducting a study on cervical cancer, he investigated the efficacy of combination immunotherapy using engineered T cells and IL-2. Moreover, he assessed the influence of cell density, intratumoral heterogeneity, and mutations in multidrug resistance, considering the continuum model as the most suitable approach for modeling resistance heterogeneity in metastasis. In collaboration with Heyrim Cho, he also investigated the impact of competition between cancer cells and healthy cells on optimal drug delivery and indicated that in scenarios with moderate competition, combination therapies are more effective, whereas in highly competitive situations, targeted drugs prove to be more effective.
Personal life
Levy is a magician member of the Academy of Magical Arts in Hollywood (Magic Castle) and a member of the Order of Merlin of the International Brotherhood of Magicians (I.B.M.). Throughout his academic career, he has highlighted the connection between performing arts and the academic world.
Awards and honors
1998 – Haim Nessyahu Prize, Israeli Union of Mathematics
2002 – Career Award, National Science Foundation
2014 – Fellow, John Simon Guggenheim Memorial Foundation
Fellow of the American Mathematical Society in the 2024 class of fellows
Selected articles
Levy, D., & Tadmor, E. (1998). From semidiscrete to fully discrete: Stability of Runge—Kutta schemes by the energy method. SIAM review, 40(1), 40–73.
Kim, P. S., Lee, P. P., & Levy, D. (2008). Dynamics and potential impact of the immune response to chronic myelogenous leukemia. PLoS computational biology, 4(6), e1000095.
Tomasetti, C., & Levy, D. (2010). Role of symmetric and asymmetric division of stem cells in developing drug resistance. Proceedings of the National Academy of Sciences, 107(39), 16766–16771.
Lavi, O., Greene, J. M., Levy, D., & Gottesman, M. M. (2013). The role of cell density and intratumoral heterogeneity in multidrug resistance. Cancer research, 73(24), 7168–7175.
Cho, H., & Levy, D. (2018). Modeling the chemotherapy-induced selection of drug-resistant traits during tumor growth. Journal of theoretical biology, 436, 120–134.
References
Living people
Year of birth missing (living people)
Applied mathematicians
Israeli magicians
Tel Aviv University alumni
University of Maryland, College Park faculty
Stanford University faculty
Fellows of the American Mathematical Society | Doron Levy | [
"Mathematics"
] | 1,632 | [
"Applied mathematics",
"Applied mathematicians"
] |
74,569,062 | https://en.wikipedia.org/wiki/5%CE%B1-Hydroxylaxogenin | 5α-Hydroxylaxogenin is a chemical compound which is a semi-synthetic derivative of laxogenin. It is not found in the Chinese medicinal plant Smilax sieboldii, instead, identification of several synthetic impurities by Dr. Chittiboyina's group suggested that it is synthesized from diosgenin. It acts as a partial agonist at androgen receptors and has been sold as a bodybuilding supplement and pre-workout product.
See also
Ecdysterone
Turkesterone
References
Tertiary alcohols
Heterocyclic compounds with 5 rings
Oxygen heterocycles
Spiro compounds
Cyclic ketones
Secondary alcohols
Diols | 5α-Hydroxylaxogenin | [
"Chemistry"
] | 137 | [
"Pharmacology",
"Medicinal chemistry stubs",
"Organic compounds",
"Pharmacology stubs",
"Spiro compounds"
] |
74,570,526 | https://en.wikipedia.org/wiki/Heterosporium%20luci | Heterosporium luci is a species of fungus in the family Cladosporiaceae. The species is a fungal plant pathogen that has been recorded from the Central African Republic, the Ivory Coast, and Senegal.
Taxonomy
The fungus was formally described by French phytopathologist Jean Chevaugeon in 1956. The type specimen was collected in Senegal.
Many species that have been historically placed in the genus Heterosporium have since been transferred to other genera, particularly Cladosporium. In their 2012 monograph on the genus Cladosporium, Konstanze Bensch and colleagues note that according to mycologist John David, who in 1997 revised the generic placement of many species previously in Heterosporium, H. luci probably does not belong in Cladosporium in the strict sense. David suggests that it is probably cercosporoid (referring to a form genus of imperfect fungi that are leaf parasites with long slender multiseptate spores) and is more likely to be appropriately classified in Passalora or Phaeoramularia, although no formal transfer to either of those genera have been made.
Description
Heterosporium luci infects the plants cassava, Citrus, and Crotalaria retusa. The fungus appears on young twigs and branches, as well as on old fallen stems and on fruits; it can additionally cover stem cankers caused by Glomerella cingulata. These cankers become covered with a dense reddish-brown to blackish-brown mat formed by the septate conidiophores of H. luci. The conidia, usually triseptate (i.e., they contain 3 internal partitions, or septa), are cylindrical to rounded, light yellow-brown, foveolate (with small, pit-like depressions or indentations) and measure 19–30 by 4.5–6.5 μm.
Distribution
Heterosporium luci has been recorded from the Central African Republic, the Ivory Coast, and Senegal.
References
Capnodiales
Fungi described in 1956
Fungi of Africa
Fungal plant pathogens and diseases
Fungus species | Heterosporium luci | [
"Biology"
] | 441 | [
"Fungi",
"Fungus species"
] |
74,571,655 | https://en.wikipedia.org/wiki/Architectural%20exaptation | Architectural exaptation is a concept in architecture and urban design that involves repurposing buildings, structures, or architectural elements for new uses that differ significantly from their original intended purpose. This practice extends beyond mere adaptation, as it involves a transformative process where the original functions are replaced or augmented by entirely new ones. It is a concept that embraces flexibility, creativity, and innovation in the use of architectural spaces and structures.
The term "exaptation," originally coined by paleontologists Stephen J. Gould and Elisabeth Vrba, is borrowed from evolutionary biology. It describes how certain features, evolved for a specific function, can be repurposed or co-opted for a different function. In architectural terms, this can be seen when buildings or their parts, designed for a specific purpose, find new life serving a completely different need. This phenomenon is manifested through two primary mechanisms: functional shift and functional co-optation (referred to as exaptation by Telmo Pievani).
Architectural exaptation is an interdisciplinary concept that connects the fields of architecture and archaeology. Architectural exaptation challenges traditional views in design and architecture that emphasize a deterministic approach where form strictly follows function. Instead, it highlights the adaptability and potential for innovation in existing structures. This concept is especially relevant in contemporary discussions about sustainability, as it promotes the reuse and creative repurposing of existing architectural resources.
Examples of architectural exaptation can range from the conversion of industrial buildings into cultural or residential spaces, to the creative reuse of minor architectural elements within a larger structure. Iconic examples include the Tate Modern in London, which transformed from a power station into a modern art gallery, the High Line in New York City, an elevated railway turned into an urban park, Ponte Vecchio in Florence, Plaza de Toros de las Arenas in Barcelona, and Temporary appropriations of public spaces exemplify this adaptability.
Architectural exaptation is not just about physical transformation; it also encompasses a philosophical shift in how we perceive the built environment. It advocates for a more fluid, imaginative approach to design, where the potential for a building or space is not limited to its original function. This concept encourages architects, urban planners, and designers to think beyond conventional boundaries and explore the multifaceted potential of the built environment.
References
Architectural terminology
Architectural elements | Architectural exaptation | [
"Technology",
"Engineering"
] | 475 | [
"Building engineering",
"Architectural elements",
"Architectural terminology",
"Components",
"Architecture"
] |
74,571,954 | https://en.wikipedia.org/wiki/Caravelli-Traversa-Di%20Ventra%20equation | The Caravelli-Traversa-Di Ventra equation (CTDV) is a closed-form equation to the evolution of networks of memristors. It was derived by Francesco Caravelli (Los Alamos National Laboratory), Fabio L. Traversa (Memcomputing Inc.) and Massimiliano Di Ventra (UC San Diego) to study the exact evolution of complex circuits made of resistances with memory (memristors).
A memristor is a resistive device whose resistance changes as a function of the history of the applied voltage or current. A physical realization of the memristor was introduced in the Nature paper by Strukov and collaborators while studying titanium dioxide junctions, with a resistance experimentally observed to change approximately in accordance to the model
where is a parameter describing the evolution of resistance, is the current across the device and is an effective parameter which characterizes the response of the device to a current flow. If the device decays over time to a high resistance state, one can also add a term to the right-hand side of the evolution for , where is a decay constant. However, such resistive switching has been known since the late 60's. The model above is often called Williams-Strukov or Strukov model. Albeit this model is too simplistic to represent real devices, it still serves as a good model exhibiting a pinched hysteresis loop in the current-voltage diagram. However, because of Kirchhoff's laws, the evolution of networks of these components becomes utterly complicated, in particular for disordered neuromorphic materials such as nanowires. Often, these are called memristive networks. The simplest example of a memristive circuit or network is a memristors crossbar. A memristor crossbar is often used as a way to address single memristors for a variety of applications in artificial intelligence. However, this is a one particular example of memristive network arranged on a two dimensional grid. Memristive networks have also important applications, for instance, in reservoir computing. A network of memristors can serve as a reservoir for nonlinearly transforming an input signal into a high-dimensional feature space. The memristor-based reservoir concept was introduced by Kulkarni and Teuscher in 2012. While this model was initially employed for tasks like wave pattern classification and associative memory, the readout mechanism utilized a genetic algorithm, which inherently operates non-linearly.
A memristive network is a circuit that satisfies the Kirchhoff laws, e.g. the conservation of the currents at the nodes, and in which every circuit element is a memristive component. Kirchhoff's laws can be written in terms of the sum of the currents on node n as
where the first equation represents the time evolution of the memristive element's internal memory either in current or voltage, and the second equation represents the conservation of currents at the nodes. Since every element is Ohmic, then, which is Ohm's law and is the memory parameters. These parameters typically represent the internal memory of the resistive device and are associated to physical properties of the device changing as an effect of current/voltage. These equations become quickly highly nonlinear because the memristive device is typically nonlinear, and moreover Kirchhoff's laws introduce a higher layer of complexity. A silver nanowire connectome can be described using graph theory, and have applications ranging from sensors to information storage.Since memristive devices behave as axons in a neuronal network, the theory of memristive networks is the theory of nanoscale electric physical devices whose behavior parallels the one of real neuronal circuits.
In neuromorphic engineering, the goal is the use of very-large-scale integration (VLSI) systems containing electronic analog circuits to mimic neuro-biological architectures similar to the ones in the nervous system. A neuromorphic computer/chip is any device that uses physical artificial neurons (made from silicon) to do computations. The development of the formalism of memristive networks is used to understand the behavior of memristors for a variety of purposes, including modelling and understand electronic plasticity in real circuits. Side applications of such theory is to understand the role of instances in memcomputers and self-organizing logic gates.
In a typical memristive network simulation one has to solve first for Kirchhoff's laws numerically, obtain voltage drops and currents for each device, and then evolve the parameters of the memristive device and/or junction to obtain the resistance or conductance. This means that effectively, as memristive devices change their resistance or conductance, such devices are interacting. Even for the simple memristor model, such a problem leads to nonlinearities strongly dependent on the circuit realizations. The CTDV equation is a model for the evolution of networks of arbitrary circuits composed of devices such as in eqn. (1), with the inclusion of a decay parameter controlling the volatility. It can be considered a generalization of the Strukov et al. model to arbitrary circuits.
For the case of the Strukov et al. model, equations (2) can be written explicitly by integrating analytically Kirchhoff's laws. The evolution of a network of memristive devices can be written in a closed form (Caravelli-Traversa-Di Ventra equation):
as a function of the properties of the physical memristive network and the external sources, where is the internal memory parameter of each device. The equation is valid in the case of the Strukov original toy model and it can be considered as a generalization of the single device model; in the case of ideal memristors, , although the hypothesis of the existence of an ideal memristor is debatable. In the equation above, is the "forgetting" time scale constant, typically associated to memory volatility, while is the adimensional ratio between the resistance gap and off resistance value. is the vector of the voltage sources in series to each junction. Instead, is a projection matrix in which the circuit enters directly, by projecting on the fundamental loops of the graph; such matrix enforces Kirchhoff's laws. Interestingly, the equation is valid for any network topology simply by changing the corresponding matrix . The constant has the dimension of a voltage and is associated to the properties of the memristor; its physical origin is the charge mobility in the conductor. The diagonal matrix and vector and respectively, are instead the dynamical internal value of the memristive devices, with values between 0 and 1. This equation thus requires adding extra constraints on the memory values in order to be reliable, but can be used for instance to predict analytically the presence of instantonic transitions in memristive networks.
References
External links
Memristive Circuits - MIT Net Advances in Physics, Accessed January 9, 2024
Memcomputing and Instantons, NASA, Accessed January 9, 2024
Kirchhoff's laws and memristive circuits, Bachelor thesis, Accessed January 9, 2024
F. Sheldon thesis, PhD thesis, Accessed January 9, 2024
Talk by JP Carbajal, Caravelli-Traversa-Di Ventra equation for optimization (minute 40), Accessed January 9, 2024
Equations of physics | Caravelli-Traversa-Di Ventra equation | [
"Physics",
"Mathematics"
] | 1,553 | [
"Mathematical objects",
"Equations of physics",
"Equations"
] |
74,572,292 | https://en.wikipedia.org/wiki/Colacogloeaceae | The Colacogloeaceae are a family of fungi in the class Microbotryomycetes. Members of the family produce yeast states; hyphal states, where known, give rise to auricularioid (laterally septate) basidia and are parasitic on other fungi.
References
Basidiomycota families
Pucciniomycotina
Yeasts
Taxa described in 2015 | Colacogloeaceae | [
"Biology"
] | 81 | [
"Yeasts",
"Fungi"
] |
74,574,126 | https://en.wikipedia.org/wiki/Microtubular%20membrane | A microtubular membrane is a type of membrane made up of small tubular structures. Microtubular associated membranes are found in various cell types and are essential for maintaining cell structure and function. Synthetic membranes are used in chemical separation processes and in flow batteries.
Biology
Cytoskeletal proteins interact with lipid bilayer membranes via interaction with peripheral or integral membrane proteins or through specific domains of cytoskeletal proteins with the lipid bilayer. A characteristic feature of protozoan parasites is an ordered layer of microtubules beneath the cell membrane.
The interaction between microtubules and the plasma membrane provide support, shape, and stability to the cell, as well as act as tracks for transporting materials within the cell. Overall, microtubular membranes are vital components of cellular organization and function. Animal cells (and some filamentous fungi are thought to rely upon the microtubule cytoskeleton and associated motor proteins. Although plants, algae and fungi transport depends on myosins, which move along the actin cytoskeleton, certain organelles can move along microtubules in plant cells.
Applications
Flow battery
Sub-millimeter, bundled microtubular (SBMT) membrane mitigate membrane pressure, which allows ions to pass through without additional support infrastructure This reduces the cost and size of the battery. A demonstration cells displayed higher peak charge and discharge power densities of 1,322 W/Lcell and 306.1 W/Lcell, respectively, compared with <60 W/Lcell and 45 W/Lcell, for conventional (planar) flow cells. SBMT's reduced the inter=membrane distance by ~100-fold and eliminated bulky flow distributors. The battery architecture is compatible with multiple chemistries, including zinc- oxide, zinc–bromide, quinone–bromide, and vanadium.
See also
Nanotube membrane
References
Rechargeable batteries
Cell biology | Microtubular membrane | [
"Biology"
] | 394 | [
"Cell biology"
] |
74,575,092 | https://en.wikipedia.org/wiki/Kohn%E2%80%93Luttinger%20superconductivity | Kohn–Luttinger superconductivity is a theoretical mechanism for unconventional superconductivity proposed by Walter Kohn and Joaquin Mazdak Luttinger based on
Friedel oscillations. In contrast to BCS theory, in which Cooper pairs are formed due to electron–phonon interaction, Kohn–Luttinger mechanism is based on fact that screened Coulomb interaction oscillates as and can create Cooper instability for non-zero angular momentum .
Since Kohn–Luttinger mechanism does not require any additional interactions beyond Coulomb interactions, it can lead to superconductivity in any electronic system.
However, the estimated critical temperature, , for Kohn–Luttinger superconductor is exponential in and thus is extremely small. For example, for metals the critical temperature is given by
where is Boltzmann constant and is Fermi energy. However, Kohn and Luttinger conjectured that nonspherical Fermi surfaces and variation of parameters may enhance the effect. Indeed, it is proposed that Kohn–Luttinger mechanism is responsible for superconductivity in rhombohedral graphene, which has an annular Fermi surface.
Further reading
References
Condensed matter physics
Superconductivity | Kohn–Luttinger superconductivity | [
"Physics",
"Chemistry",
"Materials_science",
"Engineering"
] | 262 | [
"Matter",
"Physical quantities",
"Superconductivity",
"Phases of matter",
"Materials science",
"Condensed matter physics",
"Electrical resistance and conductance"
] |
74,576,076 | https://en.wikipedia.org/wiki/Fertilysin | Fertilysin (WIN 18446) is an experimental drug that was studied as a male contraceptive, but was never marketed. It interferes with testicular production of retinoic acid, which is necessary for spermatogenesis. In studies in male animals including rodents, wolves, cats, and shrews, fertilysin was found to be a safe, effective, and reversible oral contraceptive. However, the side effects observed in human clinical trials preclude its use in men.
Fertilysin was originally studied in the 1950s for its potential amebicidal effects. When the anti-spermatogenesis effects were observed in animal studies, the focus of the research turned towards its potential use as a contraceptive. Fertilysin is an inhibitor of aldehyde dehydrogenase 1a2, a member of the aldehyde dehydrogenase family of enzymes. Inhibition of this enzyme blocks the production of retinoic acid which prevents the production of sperm. Because aldehyde dehydrogenases are also involved in the metabolism of ethanol, fertilysin has side effects similar to the action of disulfiram (Antabuse). Fertilysin may also have teratogenic effects.
References
Abandoned drugs
Amides
Organochlorides
Contraception for males | Fertilysin | [
"Chemistry"
] | 271 | [
"Functional groups",
"Amides",
"Drug safety",
"Abandoned drugs"
] |
74,576,446 | https://en.wikipedia.org/wiki/Kac%20ring | In statistical mechanics, the Kac ring is a toy model introduced by Mark Kac in 1956 to explain how the second law of thermodynamics emerges from time-symmetric interactions between molecules (see reversibility paradox). Although artificial, the model is notable as a mathematically transparent example of coarse-graining and is used as a didactic tool in non-equilibrium thermodynamics.
Formulation
The Kac ring consists of equidistant points in a circle. Some of these points are marked. The number of marked points is , where . Each point represents a site occupied by a ball, which is black or white. After a unit of time, each ball moves to a neighboring point counterclockwise. Whenever a ball leaves a marked site, it switches color from black to white and vice versa. (If, however, the starting point is not marked, the ball completes its move without changing color.)
An imagined observer can only measure coarse-grained (or macroscopic) quantities: the ratio
and the overall color
where , denote the total number of black and white balls respectively. Without the knowledge of detailed (microscopic) configuration, any distribution of marks is considered equally likely. This assumption of equiprobability is comparable to Stosszahlansatz, which leads to Boltzmann equation.
Detailed evolution
Let denote the color of a ball at point and time with a convention
The microscopic dynamics can be mathematically formulated as
where
and is taken modulo . In analogy to molecular motion, the system is time-reversible. Indeed, if balls would move clockwise (instead of counterclockwise) and marked points changed color upon entering them (instead of leaving), the motion would be equivalent, except going backward in time. Moreover, the evolution of is periodic, where the period is at most . (After steps, each ball visits all marked points and changes color by a factor .) Periodicity of the Kac ring is a manifestation of more general Poincaré recurrence.
Coarse-graining
Assuming that all balls are initially white,
where is the number of times the ball will leave a marked point during its journey. When marked locations are unknown (and all possibilities equally likely), becomes a random variable. Considering the limit when approaches infinity but , , and remain constant, the random variable converges to the binomial distribution, i.e.:
Hence, the overall color after steps will be
Since the overall color will, on average, converge monotonically and exponentially to 50% grey (a state that is analogical to thermodynamic equilibrium). An identical result is obtained for a ring rotating clockwise. Consequently, the coarse-grained evolution of the Kac ring is irreversible.
It is also possible to show that the variance approaches zero:
Therefore, when is huge (of order 1023), the observer has to be extremely lucky (or patient) to detect any significant deviation from the ensemble averaged behavior.
See also
Ehrenfest model
References
Statistical mechanics | Kac ring | [
"Physics"
] | 622 | [
"Statistical mechanics"
] |
74,578,936 | https://en.wikipedia.org/wiki/Sodium%20ammonium%20tartrate | Sodium ammonium tartrate (NAT) is an organic compound with the formula . The salt is derived from tartaric acid by neutralizing with ammonia and with sodium hydroxide. Louis Pasteur obtained enantiopure crystals of the tetrahydrate of NAT, via the process of spontaneous resolution. His discovery led to increased study of optical activity, which eventually was shown to have broad implications. Many modifications of this salt have been investigated by X-ray crystallography, including the racemate, which crystallizes as the monohydrate.
Related compounds
, known as Rochelle salt, was the first ferroelectric material discovered.
References
Organic sodium salts
Ferroelectric materials
Tartrates
Double salts
Ammonium compounds | Sodium ammonium tartrate | [
"Physics",
"Chemistry",
"Materials_science"
] | 152 | [
"Physical phenomena",
"Ferroelectric materials",
"Double salts",
"Salts",
"Organic sodium salts",
"Materials",
"Electrical phenomena",
"Ammonium compounds",
"Hysteresis",
"Matter"
] |
74,579,145 | https://en.wikipedia.org/wiki/The%20Librarian%20%28version%20control%20system%29 | The Librarian is a version control system and source code management software product originally developed by Applied Data Research for IBM mainframe computers. It was designed to supplant physical punched card decks as a way of maintaining programs, but kept a card model in terms of its interface. During the 1970s and 1980s it was in use at thousands of IBM mainframe installations and was one of the best-selling software products in the computer industry.
After Applied Data Research was acquired by Computer Associates in 1988, the product became known as CA-Librarian. After that company was acquired by Broadcom in 2018, the product became known simply as Librarian.
History
Most computer source programs in the 1960s were kept on punched cards, which was problematic due to the amount of physical space they took, the constant chance of card decks being dropped or otherwise damaged, and problems with keeping a history of changes to the program. Even into the mid-to-late 1970s, when other forms of computer input emerged, the punched card deck was still the most important of these, and this was also true for the source code for computer programs themselves.
During its early years, Applied Data Research (ADR) was developing Autoflow, a program for automatic flowcharting, which is often cited as one of the first commercial software applications. The ADR staff wanted something to help manage the increasing size of the Autoflow source code base. Martin Goetz, an ADR co-founder, had used the UNITYPER system during a prior employment with Sperry Rand. This device wrote typed input onto a metal magnetic tape. Goetz realized that source code did not have to live on punched cards, but instead could be kept in stable magnetic storage; a program called the Librarian that did this was then built for in-house use.
ADR employees realized that what was valuable to them would be valuable to others. At first, Librarian was offered as part of ADR's Autoflow, and other software packages. This arrangement was in place by 1969. At this point, Librarian master files were kept on magnetic tape; an advertisement that ADR ran in Datamation in 1970 related the story of being able to save Librarian tapes when a fire broke out, whereas it would have been impossible to save the equivalent amount of source code had it been in punched card file cabinets.
Soon, ADR recognized that Librarian had a market of its own. By 1971, advertisements were running for the Librarian in Computerworld that did not mention it in connection with any other ADR products. A shift was made to Librarian master files being kept on mainframe disk drives, with ADR saying that data compression was used to keep disk drive usage to a minimum.
The Librarian quickly found success in the market and began being used by a large number of installations. The Librarian, along with Autoflow, became responsible for much of ADR's revenue and rapid growth as a company. Per a survey that ADR conducted amongst its customers, use of the Librarian significantly increased programmer productivity, especially in the areas of ongoing maintenance and enhancement of existing applications. Buoyed by this, ADR introduced other software packages in the category of programming tools.
By 1973, the Librarian had garnered a spot in the Datapro Research Corporation's Software Honor Roll for the number of customers and associated satisfaction that the package had, based on surveys conducted by Datapro. It made the Honor Roll in subsequent years as well. One 1979 analysis of software packages for IBM mainframe environments rated the Librarian as one of the few packages that excelled both in total number of installations and total amount of sales volume.
According to sales figures given to International Computer Programs, Inc. (ICP), by 1977, the Librarian was in use at some 3,300 sites – the most of any such software package it was tracking – and had aggregate sales revenues of over $10 million. By 1979, that number had increased to 4,500 installations. In 1982, ICP gave The Librarian an award for $50 million in total sales.
In 1985, the Librarian was named by ICP as a recipient for the $100 Million Award, again reflecting lifetime aggregate sales. It was one of only a handful of system software products to reach that level. This was followed in 1989, when ICP gave an award for $250 million in total sales for Librarian.
Throughout much of its existence, Librarian's main competitor was the Panvalet product from Pansophic Systems. It had roughly the same number of installations as the Librarian. As recollected by Pansophic's founder, Joseph A. Piscopo, "Panvalet and Librarian basically divided the program library market between the two of them.... Virtually everyone ended up with one or the other of the products."
Operation
The punched card was at the time the model for many kinds of computer input, including for those representing source code. The Librarian works by interspersing its own control cards with the source program cards. These could be physical cards, or later, lines in a file kept on disk and shown and edited on display terminals. In any case, the Librarian operated under a batch processing model.
Librarian control cards begin with a hyphen. Some, such as -DESC, -PGMR, and -LANG, are used to provide basic identifying information about a Librarian module. For the language, some typical values are ASM for 370 Assembly language and CBL for COBOL.
The Librarian makes use of sequence numbers in the source file. Traditionally these occurred as columns 1–6 of a COBOL line (before the continuation indicator in column 7, area A starting in column 8 and area B starting in column 12), or columns 73–80 of a 370 Assembly language line, likewise columns 73–80 for FORTRAN, and so forth. For instance, on the Librarian -ADD control card, which adds a new source module to Librarian, the option SEQ=COBOL indicates that the sequencing numbers to Librarian should match those normally used in COBOL programming.
The main control cards used in modifying existing programs are -INS, -REP, and -DEL. An example set of cards to update a COBOL program might be:
-REP 340
RECORD CONTAINS 704 CHARACTERS
-INS 360
01 PER-MASTER-REC.
03 PER-MASTER-KEY.
05 PER-MASTER-DIV PIC XX.
05 PER-MASTER-DEPT PIC 999.
05 PER-MASTER-JOB-CL PIC 999.
05 FILLER PIC XXX.
-REP 430
03 FILLER PIC X(693).
-DEL 540,590
-REP 1470
OR PER-MASTER-DIV GREATER THAN '94'.
The -INC control card can be used for including the source of another module into this one. It serves as an extralinguistic feature for programming languages or kept data that do not have an include directive of any kind or for shops that prefer that the source configuration system do inclusions even for languages that did have such a directive. Librarian users have control over under which circumstances, or phase, any -INC statements would be expanded. For instance, the inclusion will be done by a -SEL modname operation but not by a -PUNCH operation. In practice, however, inclusion of this kind can also be done using language-specific constructs, such as the COBOL COPY statement.
While Librarian insert/replace/deletion operations were tractible for modifications to existing code, they were an awkward vehicle in which to write new programs, where large numbers of changes or refactorings would often take place. One practice to work around this was to keep the program in a file in an online, interactive environment with a text editor, such as Source Program Maintenance Online running under CICS, that would be repeatedly submitted for batch compiles or assemblies. The file would comprise something like:
...
// EXEC STRMLIB
-DLM modulename, pswd
-ADD modulename, pswd, [other options]
complete source code of program
// EXEC ASM/COBCL/whatever
...
In this way, the module under development could be edited within the online text editor rather than with Librarian control cards, but the latest iteration would still be preserved within Librarian between batch compiles. Once the program was in a working state, however, normal Librarian updates would be done in order to keep track of changes to the module. Later, a workflow such as this could be done via the editor in the IBM ISPF facility.
In addition to keeping track of the history of changes to modules, the Librarian had features that supported the auditability, integrity, and recoverability of the master file of source modules.
Releases
The Librarian went through a series of releases, both to add new functionality and to support changes in IBM mainframe environments. For instance, a new release in 1976 added support for the OS/VS1 and OS/VS2 operating systems. An illustration of an enhancement was the addition of the LIB/AM interface in 1983, which allowed the Librarian to appear like a partitioned data set to certain programs and utilities. Some of ADRs other offerings were integrated with the Librarian, for instance its Datadictionary product.
By 1981, Release 3.0 of the Librarian was out. Release 3.4, made in 1985, added support for the more interactive VM/CMS operating system and ISPF environment, both at the CMS command line and in ISPF panels and menus and editors. By 1986, the Librarian Release 3.5 was out, introducing a Change Control Facility for greater management and awareness of the software development cycle. Early 1988 saw version 3.7 which added the Change Control Facility to the CMS/ISPF environment
Release 3.8 of the Librarian came out later in 1988, just as the product was being acquired by Computer Associates. It added the Librarian/Change Control Facility functionality for the DOS/VSE platform.
Later years
Over time, approaches to version control began to move away from the Librarian model, with the Source Code Control System (SCCS) being an important early alternative. This was, as one of the creators of it said, "a radical departure from conventional methods for controlling source code", and gave more flexibility for complicated situations such as branching. SCCS was actually originally written for IBM OS/370, but found favor on the UNIX operating system for the PDP-11 where it was included in the Programmer's Workbench.
Nonetheless, the IBM mainframe world still went on. In 1988, ADR was acquired by Computer Associates (CA). The ADR product then became known as CA-Librarian. CA made enhancements to some of its other products to integrate with CA-Librarian. By 2003, version 4.3 of CA-Librarian was available, and was billed as being part of CA's AllFusion product suite. Release 4.4 of CA-Librarian appears to have come out in 2010.
In 2018, Broadcom Inc. acquired CA Technologies (the latest name for Computer Associates). The product name then became simply Librarian, although the CA-Librarian name did not disappear.
, the Librarian is part of Broadcom's Mainframe Software line under a category for DevOps-related products. The current product version is Librarian 4.4.
The 2022 book Modern Mainframe Development, published by O'Reilly Media, lists CA Librarian as one of the source control systems still in use by mainframe developers, along with a few others such as IBM Software Configuration and Library Manager and ChangeMan ZMF from Micro Focus.
See also
History of software configuration management
References
External links
The LIBRARIAN: Total Control of Your Software Asset – ADR promotional brochure, 1988
Librarian 4.4 – Broadcom web page, 2023
1960s software
Configuration management
Proprietary version control systems
IBM mainframe software
CA Technologies | The Librarian (version control system) | [
"Engineering"
] | 2,410 | [
"Systems engineering",
"Configuration management"
] |
74,579,575 | https://en.wikipedia.org/wiki/Maui%20Nui%20Venison | Maui Nui Venison is a venison producer on the island of Maui, Hawaii. The company harvests axis deer, an invasive species in Hawaii, in order to balance the population, and sells the resulting meat. Its night harvesting and field processing system is unique in the world.
History
Maui Nui Venison was founded in 2015 by Jake and Ku‘ulani Muise to address the invasive axis deer problem on Maui by culling them and selling the meat to the public. Axis deer are native to the Indian subcontinent, and were brought to Hawaii in the 1860s, as a gift to the Hawaiian king. The deer are prolific breeders, one of the few deer species able to breed year-round, and have no predators on the island. In large numbers, they cause severe damage to the island's ecosystem. As of 2023, the axis deer population on Maui numbers 50,000 to 60,000, growing at about 30% annually.
Jake Muise was formerly axis deer coordinator for the Big Island Invasive Species Committee. The organization led eradication efforts on Hawaii Island, after the deer, populous on the islands of Molokai, Lānai and Maui, were illegally introduced to the main island in 2009. High tech tracking methods involving camera traps, forward-looking infrared (FLIR), and radio telemetry were used to aid in locating the animals.
In order to commercially hunt wild deer, Maui Nui Venison had to comply with US Department of Agriculture (USDA) regulations for hunting and processing, and animal and meat inspection. A hunting operation on Molokai, Molokai Wildlife Management, in 2007 became the first in Hawaii to obtain a USDA permit to cull axis deer and sell the USDA-certified meat.
Operations
The company uses FLIR equipment to track the deer at night, and kills, processes and stores the venison in a mobile facility. The intention is to allow the animals to roam wild and unstressed by the hunt, until the moment of death. Following USDA requirements, only single headshots are permitted. The hunters carry the carcasses on their backs to the processing facility to avoid ground contamination. Hunting is conducted on privately owned ranches, where the majority of the deer live. To meet US certification requirements, the harvest team is accompanied by a USDA inspector, and each carcass is inspected by a USDA veterinarian. The overall system makes it the only such field operation in the world.
Products
Maui Nui sells the entire animal online, as cuts of meat, bone broth, individual organs, ground meat, jerky, and pet treats. Products are shipped frozen, available within the United States.
References
Hunting in the United States
Deer hunting
Maui
Invasive animal species in the United States
Ecological restoration
Meat processing in the United States
Meat companies of the United States
Food and drink companies based in Hawaii | Maui Nui Venison | [
"Chemistry",
"Engineering"
] | 589 | [
"Ecological restoration",
"Environmental engineering"
] |
47,596,170 | https://en.wikipedia.org/wiki/Trelagliptin | Trelagliptin (trade name Zafatek) is a pharmaceutical drug used for the treatment of type 2 diabetes (diabetes mellitus).
Indications
It is a highly selective dipeptidyl peptidase-4 inhibitor that is typically used as an add on treatment when the first line treatment of metformin is not achieving the expected glycemic goals; though it has been approved for use as a first line treatment when metformin cannot be used.
Biochemistry
DPP-4 inhibitors activate T-cells and are more commonly known as T-cell activation antigens (specifically CD26). Chemically, it is a fluorinated derivative of alogliptin.
Development
Formulated as the salt trelagliptin succinate, it was approved for use in Japan in March 2015. Takeda, the company that developed trelagliptin, chose to not get approval for the drug in the US and EU. The licensing rights that Takeda purchased from Furiex Pharmaceuticals for DPP-4 inhibitors included a clause specific to development of this drug in the US and EU. The clause required that all services done for phase II and phase III clinical studies in the US and EU be purchased through Furiex. Takeda chose to cease development of this drug in the US and EU because of the high costs quoted by Furiex for these services. Gliptins have been on the market since 2006 and there are 8 gliptins currently registered as drugs (worldwide). Gliptins are an emerging market and are thus being developed at an increasing rate; there are currently two gliptins in advanced stages of development that are expected to be on the market in the coming year.
Gliptins are thought to have cardiovascular protective abilities though the extent of these effects is still being studied. They are also being studied for the ability that this class of drugs has at promoting B-cell survival.
Administration and dosing
Similar drugs in the same class as trelagliptin are administered once daily while trelagliptin is administered once weekly. Alogliptin (Nesina) is the other major DPP-4 inhibitor on the market. It is also owned by Takeda and is administered once daily. A dosing of once per week is advantageous as a reduction in the frequency of required dosing is known to increase patient compliance.
A recent meta-analysis published by Dutta et. al. highlighted the good glycaemic efficacy and safety of this molecule as compared to peer DPP4 inhibitors which have to be taken daily like alogliptin, sitagliptin, linagliptin, teneligliptin, anagliptin or vildagliptin, having an advantage of reducing the monthly pill count from 30 to 4.
Brand names
In Bangladesh it is marketed under the trade name Wedica.
References
Dipeptidyl peptidase-4 inhibitors
Pyrimidinediones
Fluoroarenes
Piperidines
Nitriles | Trelagliptin | [
"Chemistry"
] | 614 | [
"Nitriles",
"Functional groups"
] |
47,596,400 | https://en.wikipedia.org/wiki/Janet%20Abbate | Janet Abbate (born June 3, 1962) is an associate professor of science, technology, and society at Virginia Tech. Her research focuses on the history of computer science and the Internet, particularly on the participation of women in the field. Janet Abbate is also the author of Inventing the Internet (MIT Press, 1999), Standards Policy for Information Infrastructure (MIT Press, 1995), and Recoding Gender Women’s Changing Participation in Computing (MIT Press, 2012). Janet Abbate also attended The University of Pennsylvania for her Ph.D.
Academic career
Abbate received her bachelor's degree from Radcliffe College and her master's degree from the University of Pennsylvania. She also received her Ph.D. from the in American Civilization from the University of Pennsylvania in 1994. From 1996 to 1998, she was a postdoctoral fellow with the IEEE History Center, where she conducted research on women in computing. She joined the faculty of Virginia Tech's Northern Capital Region campus in 2004 and is now an associate professor and the co-director of the graduate program in Science, Technology, and Society. Janet Abbate earned a BA from Harvard University, a MA from the University of Pennsylvania, and a PhD from the University of Pennsylvania.
Prior to her academic work, Abbate was a computer programmer herself. Her background in computer programming has influenced her research approach and has been cited as relevant in reviews of her work.
Research
In 1995, Abbate co-edited Standards Policy for Information Infrastructure with Brian Kahin. Some of her main areas of research focus include: Gender in Science and Technology, History of Computing the Internet, and Labor Issues in Science and Technology.
Abbate is the author of two books: Inventing the Internet (2000) and Recoding Gender: Women’s Changing Participation in Computing (2012). Inventing the Internet was widely reviewed as an important work in the history of computing and networking, particularly in highlighting the role of social dynamics and of non-American participation in early networking development. The book was also praised for its use of archival resources to tell the history. Though some have criticized the work, citing Abbate's computer programming background as causing issues in presenting a non-technical narrative. She has since written about the need for historians to be aware of the perspectives they take in writing about the history of the Internet and explored the implications of defining the Internet in terms of "technology, use and local experience" rather than through the lens of the spread of technologies from the United States.
Recoding Gender also received positive reviews, especially for its incorporation of interviews with women in the field and for providing a historical overview of how women and gender have shaped computer programming. However, the book has also been criticized for being disjointed—that the link of "women in computing" is not strong enough to hold the different chapters together. The book received the 2014 Computer History Museum prize.
Janet Abbate is currently researching historical emergence of computer science as an intellectual discipline.
See also
History of the Internet
Protocol Wars
References
1962 births
Living people
Virginia Tech faculty
Science and technology studies scholars
University of Pennsylvania School of Arts and Sciences alumni
Radcliffe College alumni
21st-century American educators
21st-century American academics
21st-century American women academics | Janet Abbate | [
"Technology"
] | 655 | [
"Science and technology studies",
"Science and technology studies scholars"
] |
47,596,422 | https://en.wikipedia.org/wiki/ColorOS | ColorOS is a user interface created by Oppo based on the Android Open Source Project. Initially, Realme phones used ColorOS until it was replaced by Realme UI in 2020. Realme UI uses some of ColorOS's apps. Starting from the OnePlus 9 series, OnePlus will preinstall ColorOS on all smartphones that are sold in mainland China instead of HydrogenOS (Chinese version of OxygenOS).
The first version of ColorOS was launched in September 2013. Oppo had released plenty of Android smartphones before then. It was not stock Android, but Oppo did not label it as ColorOS. Over the years, Oppo launched new official versions of the operating system. To make things less confusing, in 2020 the company revealed that it would adopt the same numbering scheme as mainline Android, and as such, ColorOS jumped from ColorOS 7 to ColorOS 11 with the launch of Android 11.
It was announced that ColorOS, OnePlus' Oxygen OS, and Realme UI will merge to form a single Android skin that will appear on all OnePlus, Oppo and Realme UI phones. However these plans were cancelled as the three UI's are being developed on the same codebase, but they are separate.
Version history
See also
Oppo
Oppo phones
Further reading
How OPPO's ColorOS 13 Pushes the Trend of Android Customization
References
External links
Android (operating system)
Android (operating system) forks
ARM operating systems
Mobile Linux
Software forks
Linux distributions
Custom Android firmware | ColorOS | [
"Technology"
] | 314 | [
"Operating system stubs",
"Computing stubs"
] |
47,597,281 | https://en.wikipedia.org/wiki/Worbla | Worbla is a brand of thermoplastic modelling materials, popular among cosplayers for creating costumes, armor and props.
The name of the material is that of Worbla AG, a former synthetics manufacturer in Worblaufen, Switzerland, now part of the Gurit group. The material is marketed by the German company Cast4Art Vertriebsgesellschaft.
Use
In order to be shaped, Worbla is warmed up, usually with a hot air gun, until it becomes formable at . It is then draped over formers or hand-moulded (wearing gloves) to shape. The inbuilt adhesive allows multiple layers to be laminated easily, for either strength or to add bas relief detail. A common technique for wearable props such as armour is to laminate it to thin EVA foam sheet, giving a light and slightly flexible carapace.
Worbla can also be moulded, when warmed, as a putty and used to sculpt solid pieces. Unusually, offcuts of sheet can be recycled in this way. The material can be cut with scissors, knives or by laser. When cold it can be cut, carved or sanded with woodworking hand tools. The surface is slightly rough, similar to some grades of leather, which allows textured paint effects. For a smooth surface it can be either sanded or filled with a primer paint.
Cosplayers and prop makers have widely adopted Worbla for its light weight, and easy working with minimal tools.
Varieties and properties
Worbla is made in several varieties:
Finest Art: The original "Worbla", a sheet material composed of a thermoplastic resin and wood flour filler. Standard sheets are around thick. The sheet is coated on one side with a heat-activated adhesive.
Flame Red Art: Similar to the original, but with a flame retardant component, for "locations where safety is of the utmost importance".
TranspArt: A transparent polymer thermoplastic that becomes formable at .
Black: This product has a smoother surface, similar to EVA foam, and is designed to be painted with less filling and sanding needed. It is also workable at 90 °C.
Worbla’s® KobraCast Art: which initially resembles knitted plastic sheeting, is heat activated (approx. ) and can be shaped by hand, in a mold, or vacuformed. KobraCast Art contains a very strong adhesive, with a very stretchable, but tear-resistant mesh inside. Named after Kobracast see below.
Similar materials
Kobracast (called KOBRA CAST 445 in the health care industry), a thermoplastic and fabric mesh bandage from the German company KOB - Karl Otto Braun GmbH & Co. KG. Worked warm like Worbla, this is strong and flexible owing to the fabric mesh reinforcement, but does not offer the solid surface. Made of flexible PES fabric.
Poli® Plastics Polymorph and 42°C Poli® Mouldable Pellets (Friendly Plastic / Coolmorph), 3mm PCL Polycaprolactone thermoplastic beads, made in the United Kingdom, that are mouldable at 62 °C for SuperMorph or 42 °C for Coolmorph.
Cosplayflex, a thermoplastic material from Germany.
Sintra, more durable and stiffer
Kydex, a robust thermoplastic, less commonly used for props, but often for firearm holsters, and sheaths for knives.
References
Thermoplastics
Cosplay | Worbla | [
"Physics",
"Chemistry"
] | 755 | [
"Matter",
"Polymer stubs",
"Materials stubs",
"Materials",
"Organic chemistry stubs"
] |
47,597,338 | https://en.wikipedia.org/wiki/Specific%20output | Specific output is a measure of internal combustion engine performance. It describes the efficiency of an engine in terms of the brake horsepower it outputs relative to its displacement. The measure enables the comparison of differently sized engines, and is usually expressed as kilowatts or horsepower per litre or per cubic inch. On average, forced induction engines out-perform naturally aspirated engines by this measure, primarily due to their increased volumetric efficiency.
See also
Power density
List of automotive superlatives
References
Engine technology | Specific output | [
"Technology"
] | 101 | [
"Engine technology",
"Engines"
] |
47,598,638 | https://en.wikipedia.org/wiki/Crown%20shyness | Crown shyness (also canopy disengagement, canopy shyness, or inter-crown spacing) is a phenomenon observed in some tree species, in which the crowns of fully stocked trees do not touch each other, forming a canopy with channel-like gaps.
The phenomenon is most prevalent among trees of the same species, but also occurs between trees of different species. There exist many hypotheses as to why crown shyness is an adaptive behavior, and research suggests that it might inhibit spread of leaf-eating insect larvae.
Possible physiological explanations
The exact physiological basis of crown shyness is uncertain. The phenomenon has been discussed in scientific literature since the 1920s. The variety of hypotheses and experimental results might suggest that there are multiple mechanisms across different species, an example of convergent evolution.
Some hypotheses contend that the interdigitation of canopy branches leads to "reciprocal pruning" of adjacent trees: trees in windy areas suffer physical damage as they collide with each other during winds; the abrasions and collisions induce a crown shyness response. Studies suggest that lateral branch growth is largely uninfluenced by neighbours until disturbed by mechanical abrasion. If the crowns are artificially prevented from colliding in the winds, they gradually fill the canopy gaps. This explains instances of crown shyness between branches of the same organism. Proponents of this idea cite that shyness is particularly seen in conditions conducive to this pruning, including windy forests, stands of flexible trees, and early succession forests where branches are flexible and limited in lateral movement. According to this theory, variable flexibility in lateral branches greatly influences the degree of crown shyness.
Similarly, some research suggests that constant abrasion at growth nodules disrupts bud tissue such that it is unable to continue with lateral growth. Australian forester M.R. Jacobs, who studied the crown shyness patterns in eucalyptus in 1955, believed that the trees' growing tips were sensitive to abrasion, resulting in canopy gaps. Miguel Franco (1986) observed that the branches of Picea sitchensis (Sitka spruce) and Larix kaempferi (Japanese larch) suffered physical damage due to abrasion, which killed the leading shoots.
A prominent hypothesis is that canopy shyness has to do with mutual light sensing by adjacent plants. The photoreceptor-mediated shade avoidance response is a well-documented behavior in a variety of plant species. Neighbor detection is thought to be a function of several unique photoreceptors. Plants can sense the proximity of neighbors by sensing backscattered far-red light, a task widely thought to be accomplished by the activity of the phytochrome photoreceptors. Many species of plant respond to an increase in far-red light (and, by extension, encroaching neighbors) by directing growth away from the far-red stimulus and by increasing the rate of elongation. Similarly, plants use blue light to induce the shade-avoidance response, likely playing a role in the recognition of neighboring plants, though this was just starting to be recognised in 1988.
The characterization of these behaviors might suggest that crown shyness is simply the result of mutual shading based on well-understood shade avoidance responses. Malaysian scholar Francis S.P. Ng, who studied Dryobalanops aromatica, suggested that the growing tips were sensitive to light levels and stopped growing when nearing the adjacent foliage due to the induced shade.
A 2015 study has suggested that Arabidopsis thaliana shows different leaf placement strategies when grown amongst kin and unrelated conspecifics, shading dissimilar neighbors and avoiding kin. This response was shown to be contingent on the proper functioning of multiple photosensory modalities. A 1998 study proposed similar systems of photoreceptor-mediated inhibition of growth as explanations of crown shyness, though a causal link between photoreceptors and crown asymmetry had yet to be experimentally proven. This might explain instances of intercrown spacing that are only exhibited between conspecifics.
Species
Trees that display crown shyness patterns include:
Species of Dryobalanops, including Dryobalanops lanceolata and Dryobalanops aromatica (kapur)
Some species of eucalypt
Pinus contorta or lodgepole pine
Avicennia germinans or black mangrove
Schefflera pittieri
Clusia alata
K. Paijmans observed crown shyness in a multi-species group of trees, comprising Celtis spinosa and Pterocymbium beccarii
References
External links
Plant morphology
Forest ecology | Crown shyness | [
"Biology"
] | 956 | [
"Plant morphology",
"Plants"
] |
47,599,289 | https://en.wikipedia.org/wiki/Metasequoia%20occidentalis | Metasequoia occidentalis is an extinct redwood species of the family Cupressaceae that is found as fossils throughout the Northern Hemisphere. It is one of three extinct species of Metasequoia that are currently recognized as valid.
History
The species was first described in 1863 from fossils found in the outcrops of the Late Paleocene-Middle Eocene Chuckanut Formation around Birch Bay, Washington. The species was originally described as Taxodium occidentale by John Strong Newberry. Fossilized Metasequoia-like remains were noted in Europe and North America from the 1800s on, but were assigned to the cupressaceous genera Sequoia (redwoods) and Taxodium (bald cypresses). It was not until the living species Metasequoia glyptostroboides was discovered and described from a remote area of China during the 1940s, that the affinity of many of the fossils became apparent. In 1951, the species was reassigned to Metasequoia as M. occidentalis by Ralph Works Chaney based on the close resemblance to living Metasequoia. With a few notable exceptions, it has been claimed that the majority of the fossils documented in the literature show that M. occidentalis was indistigushable from living M. glyptostroboides.
Description
Like living Metasequoia, M. occidentalis was deciduous. The foliage consists of branchlets with oppositely arranged leaves. The leaves are ovate to linear in shape, ranging from in length and in width, with a distinct midvein, a petiolate base, and an acute tip. The seed-bearing cones are globose to ovoid, long and wide, with decussately arranged triangular scales, and are borne on long, leafless stalks. The seeds have two wings, are ovoid to cordate in shape, and are up to long and wide. The pollen-bearing cones are small, globose to ovoid, long and wide, and oppositely arranged on specialized stalks with one terminal cone.
Age and distribution
Metasequoia occidentalis appeared in fossil record during the Late Cretaceous epoch (Cenomanian stage). By the Tertiary period, it had become a major constituent of lowland and swampy forests in the northern circum-Pacific and polar regions, where it commonly coexisted with Glyptostrobus europaeus. Fossils assignable to M. occidentalis have been reported from parts of the United States, Canada, Russia, China, Japan, Greenland and Svalbard, but Metasequoia appears to have been rare or absent in much of Europe.
References
occidentalis
Prehistoric plants
Allenby Formation
Chu Chua Formation
Horsefly Shales
Klondike Mountain Formation
Tranquille Formation
Paleontology in Alberta | Metasequoia occidentalis | [
"Biology"
] | 592 | [
"Prehistoric plants",
"Plants"
] |
47,599,527 | https://en.wikipedia.org/wiki/KOI-256 | KOI-256 is a double star located in the constellation Cygnus approximately from Earth. While observations by the Kepler spacecraft suggested the system contained a gas giant exoplanet orbiting a red dwarf, later studies determined that KOI-256 was a binary system composed of the red dwarf orbiting a white dwarf.
Name
The acronym "KOI" comes from Kepler object of interest and means that the object has been cataloged by the Kepler spacecraft during its search for extrasolar planets using the transit method. The "256" is the number of the object.
Characteristics
Initial observations by the Kepler spacecraft suggested a central red dwarf with a mass of , a radius of , and a temperature of . Its candidate exoplanet was estimated to have a mass of , a radius of , an orbital period of 1.38 days, a temperature of , and a semi-major axis of 0.021 astronomical units. Further studies by Muirhead et al. (2012) refined the candidate exoplanet parameters to a radius of , a temperature of , and a semi-major axis of 0.016 AU.
Muirhead et al. (2013) performed additional observations with the Hale Telescope at Palomar Observatory. Using the radial velocity method for exoplanet detection, Muirhead's team found that the red dwarf was wobbling too much to be caused by a planetary mass object, and was more likely being influenced by a white dwarf. Using ultraviolet data from the GALEX spacecraft, it was seen that the red dwarf was significantly active, further suggesting perturbations by a white dwarf. The team re-analyzed Kepler data, and found that when the white dwarf passed in front of the red dwarf, the red dwarf's light noticeably warped and brightened, an effect called gravitational lensing. While only being slightly larger than the Earth, the white dwarf has such large mass that the physically larger red dwarf orbits around its smaller companion.
With the new observations, the red dwarf was shown to have a mass of , a radius of , and a temperature of . The white dwarf has a mass of , a radius of , and a temperature of .
References
Astronomical objects discovered in 2009
Cygnus (constellation)
Eclipsing binaries
256
J19004443
M-type main-sequence stars
White dwarfs | KOI-256 | [
"Astronomy"
] | 467 | [
"Constellations",
"Draco (constellation)"
] |
47,601,930 | https://en.wikipedia.org/wiki/Dmitry%20Dolgopyat | Dmitry Dolgopyat is a Russian-American mathematician specializing in dynamical systems, a field that studies the time evolution of natural and abstract systems. An internationally acclaimed lecturer, he holds the position of Distinguished University Professor at the University of Maryland, and is a foreign member of the Academia Europaea.
Education
Dmitry Dolgopyat graduated from Moscow State School 57 mathematical class in 1989.
From 1989 to 1994, he was an undergraduate student at Moscow State University.
From 1994 to 1997, Dolgopyat was enrolled at Princeton University, where he earned a PhD under the guidance of Yakov Sinai.
Career
From September 1999 to June 2003, Dmitry Dolgopyat served as an Assistant Professor at Penn State University.
Dolgopyat joined the University of Maryland as an Associate Professor from September 2002 to June 2006. During this period, he also spent a year at the Institute for Advanced Study (IAS) in Princeton (2002-2003).
He briefly returned to Penn State University as a Professor from September 2006 to June 2007 before settling at the University of Maryland as a Professor in September 2007, a position he holds to the present day.
Additionally, Dolgopyat spent a year at the University of Toronto and the Fields Institute from 2010 to 2011.
He has also served on the editorial boards of the Journal of Modern Dynamics, Nonlinearity, Ergodic Theory and Dynamical Systems, Annales Henri Poincaré, and the Journal of the American Mathematical Society, as well as on the Prize Committee of the International Bolyai Prize Committee.
Recognition
Dolgopyat was named a Distinguished University Professor in 2022 - the highest academic honor bestowed by the University of Maryland.
In 2020, he was elected a foreign member of the Academia Europaea - a pan-European Academy of Humanities, Letters, Law, and Sciences.
In 2009, he was awarded the Michael Brin Prize in Dynamical Systems for his fundamental contributions to the theory of hyperbolic dynamics.
In 2009, Dmitry Dolgopyat received the Annales Henri Poincaré Prize for the article Unbounded Orbits for Semicircular Outer Billiard coauthored with Bassam Fayad.
Earlier academic honors included the Sloan Fellowship (Fall 2000 - Spring 2002) and the Miller Fellowship (Fall 1997 - Spring 1999).
Guest Lectures and Academic Visits
Dolgopyat was an invited speaker at the 2003 International Congress on Mathematical Physics in Lisbon, at the 2006 International Congress of Mathematicians in Madrid, plenary speaker at the 2006 Canadian Mathematical Society Winter Meeting in Toronto, 2009 International Workshop Dynamics Beyond Uniform Hyperbolicity at the Beijing International Center for Mathematical Research, and at the 2012 International Congress in Mathematical Physics in Aalborg, Denmark. delivered mini-courses at the International Centre for Theoretical Physics in Trieste, Italy, and at the Centro di Ricerca Matematica Ennio De Giorgi in Pisa Italy.
Other longer mini-courses included DANCE (Dynamics, Attractors, Nonlinearity, Chaos & Stability) Winter School in Murcia, Spain, Program on Hyperbolic Dynamics in Vienna, School on Dynamics & Complexity at the University of the Republic (Uruguay), Special trimester on dynamical systems in Pisa, Dynamics Beyond Uniform Hyperbolicity in Evanston, with shorter visits to Manchester University, United Kingdom, Centro de Investigacion en Matematicas, Guanajuato, Mexico, Hebrew University, Jerusalem, Israel, Newton Institute, Cambridge, United Kingdom, Instituto de Matematica Pura e Aplicada, Rio de Janeiro, Brazil, Northwestern University, Evanston, Illinois, Scuola Normale, Pisa, Ecole Polytechnique, ETH, Zurich, IAS, Princeton, CalTech, Research Institute for Mathematical Sciences, Kyoto, Institut Henri Poincaré, Paris, Erwin Schroedinger Institute, Vienna, Centre International de Rencontres Mathématiques, Luminy, France, University of Toronto/ Fields Institute, University of Bristol, EPFL, Lausanne, Switzerland, Weizmann institute, Israel, Institute for Computational and Experimental Research in Mathematics, Providence, RI.
References
Living people
Russian mathematicians
Moscow State University alumni
Princeton University alumni
University of Maryland, College Park faculty
Dynamical systems theorists
1972 births
Members of Academia Europaea | Dmitry Dolgopyat | [
"Mathematics"
] | 867 | [
"Dynamical systems theorists",
"Dynamical systems"
] |
47,602,576 | https://en.wikipedia.org/wiki/Conjugated%20estrogens | Conjugated estrogens (CEs), or conjugated equine estrogens (CEEs), sold under the brand name Premarin among others, is an estrogen medication which is used in menopausal hormone therapy and for various other indications. It is a mixture of the sodium salts of estrogen conjugates found in horses, such as estrone sulfate and equilin sulfate. CEEs are available in the form of both natural preparations manufactured from the urine of pregnant mares and fully synthetic replications of the natural preparations. They are formulated both alone and in combination with progestins such as medroxyprogesterone acetate. CEEs are usually taken by mouth, but can also be given by application to the skin or vagina as a cream or by injection into a blood vessel or muscle.
Side effects of CEEs include breast tenderness and enlargement, headache, fluid retention, and nausea among others. It may increase the risk of endometrial hyperplasia and endometrial cancer in women with an intact uterus if it is not taken together with a progestogen like progesterone. The medication may also increase the risk of blood clots, cardiovascular disease, and, when combined with most progestogens, breast cancer. CEEs are estrogens, or agonists of the estrogen receptor, the biological target of estrogens like estradiol. Compared to estradiol, certain estrogens in CEEs are more resistant to metabolism, and the medication shows relatively increased effects in certain parts of the body like the liver. This results in an increased risk of blood clots and cardiovascular problems with CEEs relative to estradiol.
Premarin, the major brand of CEEs in use, is manufactured by Pfizer and was first marketed in 1941 in Canada and in 1942 in the United States. It is the most commonly used form of estrogen in menopausal hormone therapy in the United States. However, it has begun to fall out of favor relative to bioidentical estradiol, which is the most widely used form of estrogen in Europe for menopausal hormone therapy. CEEs are available widely throughout the world. An estrogen preparation very similar to CEEs but differing in source and composition is esterified estrogens. In 2020, it was the 283rd most commonly prescribed medication in the United States, with more than 1million prescriptions.
Medical uses
CEEs are a form of hormone therapy used in women. It is used most commonly in postmenopausal women who have had a hysterectomy to treat hot flashes, and burning, itching, and dryness of the vagina and surrounding areas. It must be used in combination with a progestogen in women who have not had a hysterectomy. For women already taking the medication, it can be used to treat osteoporosis, although it is not recommended solely for this use. Some lesser known uses are as a means of high-dose estrogen therapy in the treatment of breast cancer in both women and men and in the treatment of prostate cancer in men. It has been used at a dosage of 2.5 mg three times per day (7.5 mg/day total) for prostate cancer.
CEEs are specifically approved in countries such as the United States and Canada for the treatment of moderate to severe vasomotor symptoms (hot flashes) and vulvovaginal atrophy (atrophic vaginitis, atrophic urethritis) associated with menopause, hypoestrogenism due to hypogonadism, ovariectomy, or primary ovarian failure, abnormal uterine bleeding, the palliative treatment of metastatic breast cancer in women, the palliative treatment of advanced androgen-dependent prostate cancer in men, and the prevention of postmenopausal osteoporosis. The intravenous formulation of CEEs is specifically used to rapidly limit bleeding in women with hemorrhage due to dysfunctional uterine bleeding.
Available forms
Natural CEEs, as Premarin, are available in the form of oral tablets (0.3 mg, 0.625 mg, 0.9 mg, 1.25 mg, or 2.5 mg), creams for topical or vaginal administration (0.625 mg/g), and vials for intravenous or intramuscular injection (25 mg/vial). Synthetic CEEs, such as Cenestin (Synthetic A), Enjuvia (Synthetic B), and generic formulations, are available in the form of oral tablets (0.3 mg, 0.45 mg, 0.625 mg, 0.9 mg, or 1.25 mg) and creams for topical or vaginal administration (0.625 mg/g).
Contraindications
Contraindications of CEEs include breast cancer and a history of venous thromboembolism, among others.
Side effects
The most common side effects associated with CEEs are vaginal yeast infections, vaginal spotting or bleeding, painful menses, and cramping of the legs. While there are some contradictory data, estrogen alone does not appear to increase the risk of coronary heart disease or breast cancer, unlike the case of estrogen in combination with certain progestins such as levonorgestrel or medroxyprogesterone acetate. Only a few clinical studies have assessed differences between oral CEEs and oral estradiol in terms of health parameters. Oral CEEs have been found to possess a significantly greater risk of thromboembolic and cardiovascular complications than oral estradiol ( = 2.08) and oral esterified estrogens ( = 1.78). However, in another study, the increase in venous thromboembolism risk with oral CEEs plus medroxyprogesterone acetate and oral estradiol plus norethisterone acetate was found to be equivalent ( = 4.0 and 3.9, respectively). As of present, there are no randomized controlled trials that would allow for unambiguous conclusions.
Overdose
Estrogens, including CEEs, are relatively safe in acute overdose.
Interactions
Inhibitors and inducers of cytochrome P450 enzymes may interact with CEEs.
Pharmacology
Pharmacodynamics
CEEs are a combination of estrogens, or agonists of the estrogen receptors. The major estrogen in CEEs, sodium estrone sulfate, itself is inactive, and rather serves as a prodrug of estrone and then of estradiol. The transformation of estrone sulfate to estrone is catalyzed by steroid sulfatase, and of estrone into estradiol by 17β-hydroxysteroid dehydrogenase. CEEs (as Premarin) and estrone have been found to be equivalent in potency in an animal model of estrogenic activity. On the other hand, the active forms of the equine estrogens in CEEs, such as equilin and 17β-dihydroequilin, have greater potency in the liver relative to bioidentical estradiol, similarly to synthetic estrogens like ethinylestradiol and diethylstilbestrol. This results in disproportionate effects on liver protein production compared to estradiol, although to a lesser extent than ethinylestradiol and diethylstilbestrol. In addition, 17β-dihydroequilenin has shown a selective estrogen receptor modulator (SERM)-like profile of estrogenic activity in studies with monkeys, in which beneficial effects on bone and the cardiovascular system were observed but proliferative responses in breast or endometrium were not seen, although the clinical significance of this is unknown.
CEEs consists of the sodium salts of the sulfate esters of equine estrogens in a specific and consistent composition (see the table). The major estrogens in CEEs are sodium estrone sulfate and sodium equilin sulfate, which together account for approximately 71.5–92.0% of the total content of CEEs. CEEs are prodrugs of the active forms of the estrogens. Sodium estrone sulfate is a prodrug of estrone, which in turn is a prodrug of estradiol, while sodium equilin sulfate is a prodrug of equilin and then of 17β-dihydroequilin. As such, the major active estrogens with CEEs are estradiol and 17β-dihydroequilin, which have potent estrogenic activity and account for most of the effects of CEEs. The 17α-estrogens in CEEs such as 17α-estradiol and 17α-dihydroequilin have low estrogenicity and are thought to contribute minimally to its effects. There are many different steroids in natural CEE products like Premarin, as many as 230 compounds and including even androgens and progestogens, but only the estrogens are present in sufficient amounts to produce clinically-relevant effects.
A dosage of 0.625 mg/day oral CEEs has been found to increase SHBG levels by 100%. For comparison, 1 mg/day oral estradiol increased SHBG levels by 45%, while 50 μg/day transdermal estradiol increased SHBG levels by 12%. Ethinylestradiol is more potent in its effects on liver protein synthesis than either CEEs or estradiol, with 10 μg/day oral ethinylestradiol having been found to be approximately equivalent to 1.25 mg/day CEEs.
Antigonadotropic effects
A preliminary study of ovulation inhibition in women found that oral CEEs was 33% effective at 1.25 mg/day and 94% at 3.75 mg/day. A dosage of oral CEEs of 2.5 mg three times daily (7.5 mg/day total) has been found to suppress total testosterone levels in men to an equivalent extent as 3 mg/day oral diethylstilbestrol, which is the minimum dosage of diethylstilbestrol required to consistently suppress total testosterone levels into the castrate range (<50 ng/dL).
Pharmacokinetics
CEEs are hydrolyzed in the intestines during first-pass metabolism upon oral administration. Following their absorption, they are resulfated mainly in the liver also during the first pass. Following this, they serve as a circulating reservoir and are slowly rehydrolyzed into their unconjugated active forms.
Oral CEEs, at a daily dosage of 0.625 mg, achieve estrone and estradiol levels of 150 pg/mL and 30–50 pg/mL, respectively, while a daily oral dosage of 1.25 mg achieves levels of 120–200 pg/mL and 40–60 pg/mL of estrone and estradiol, respectively. The oral ingestion of 10 mg CEEs, which contains about 4.5 mg sodium estrone sulfate and 2.5 mg sodium equilin sulfate, produces maximal plasma concentrations of estrone and equilin of 1,400 pg/mL and 560 pg/mL within three and five hours, respectively. By 24 hours post-dose of 10 mg, the levels of estrone and equilin fall to 280 pg/mL and 125 pg/mL, respectively. Oral CEEs 1.25 mg/daily and oral micronized estradiol 1 mg/daily result in similar plasma concentrations of estrone and estradiol (150–300 pg/mL and 30–50 pg/mL for micronized estradiol, respectively) (oral estradiol is extensively metabolized into estrone during hepatic first-pass metabolism), although this does not account for equilin and other equine estrogens involved in the effects of CEEs, which may be significantly more potent in comparison to estrone. The pharmacokinetics of vaginal CEEs and of intravenous CEEs have been studied as well.
Eoncentrations of equilin that are very high relative to those of other estrogens are produced by typical clinical doses of CEEs. With a dosage of 1.25 mg oral CEEs, equilin levels of 1,082 to 2,465 pg/mL have been observed. The clinical significance of these levels of equilin is unknown.
The active forms are metabolized primarily in the liver. There is some enterohepatic recirculation of CEEs. Following a single oral dose of 0.625 CEEs, the biological half-life of estrone was 26.7 hours, of baseline-adjusted estrone was 14.8 hours, and of equilin was 11.4 hours.
Chemistry
CEEs are naturally occurring estrane steroids. They are in conjugate form, as the sodium salts of the C17β sulfate esters. The estrogens in CEEs, in their unconjugated active forms, include bioidentical human estrogens like estradiol and estrone as well as equine-specific estrogens such as equilin and 17β-dihydroequilin. The equine estrogens differ from human estrogens in that they have additional double bonds in the B ring of the steroid nucleus. CEEs contain both 17β-estrogens like estradiol and 17β-dihydroequilin and the C17α epimers like 17α-estradiol and 17α-dihydroequilin.
History
Conjugated estriol, an extract of the urine of pregnant women and sold under the brand names Progynon and Emmenin in the 1930s, was the predecessor of Premarin. Both of these products contained conjugated estrogens similarly to Premarin, but the estrogens were human estrogens as opposed to equine estrogens and the composition differed. The major active ingredient in Progynon and Emmenin was estriol glucuronide.
Estrone sulfate was first isolated from the urine of pregnant mares in the late 1930s by researchers in the Department of Biochemistry at University of Toronto. Premarin was first introduced in 1941 by Wyeth Ayerst as a treatment for hot flashes and other symptoms of menopause; at that time, Wyeth Ayerst only had to prove its safety, and not its efficacy. In response to the 1962 Kefauver Harris Amendment the FDA had its efficacy reviewed, and in 1972 found it effective for menopausal symptoms and probably effective for osteoporosis. The review also determined that two estrogens – estrone sulfate and equilin sulfate – were primarily responsible for the activity of Premarin, and it laid the groundwork for Abbreviated New Drug Application (ANDA) submissions of generic versions. In 1984 an NIH consensus panel found that estrogens were effective for preventing osteoporosis and 1986 the FDA announced in the Federal Register that Premarin was effective for preventing osteoporosis. This announcement led to a rapid growth in sales, and interest from generic manufacturers to introduce generic versions.
Conjugated estrogens was introduced for medical use under the brand name Premarin in Canada in 1941, in the United States in 1942, and in the United Kingdom in 1956.
The manufacturer of Premarin secretly paid gynecologist Robert A. Wilson to promote its use by menopausal women in his 1966 book, Feminine Forever, leading to increased sales.
Society and culture
Names
Estrogens, conjugated is the generic name of the drug and its and . It is also known as conjugated estrogens or as conjugated equine estrogens. The brand name Premarin is a contraction of "pregnant mares' urine".
CEEs are marketed under a large number of brand names throughout the world. The major brand name of the natural form of CEEs manufactured from the urine of pregnant mares is Premarin. Major brand names of fully synthetic versions of CEEs include Cenestin and Enjuvia in the United States and C.E.S. and Congest in Canada. CEEs are also formulated in combination with progestins. Major brand names of CEEs in combination with medroxyprogesterone acetate include Prempro and Premphase in the United States, Premplus in Canada, Premique in the United Kingdom and Ireland, Premia in Australia and New Zealand, and Premelle in South Africa. Prempak-C is a combination of CEEs and norgestrel which is used in the United Kingdom and Ireland, and Prempak N is a combination of CEEs and medrogestone which is used in South Africa. Many of the aforementioned brand names are also used in other, non-English-speaking countries.
Availability
CEEs are marketed and available widely throughout the world. This includes in all English-speaking countries, throughout the European Union, Latin America, Asia, and elsewhere in the world.
Health effects
Research starting in 1975 showed substantially increased risk of endometrial cancer. Since 1976, the drug has carried a label warning about the risk. As part of the Women's Health Initiative sponsored by the National Institutes of Health, a large-scale clinical trial of menopausal HRT showed that long-term use of estrogen and a progestin may increase the risk of strokes, heart attacks, blood clots, and breast cancer. Following these results, Wyeth experienced a significant decline in its sales of Premarin, Prempro (CEEs and medroxyprogesterone acetate), and related products, from over $2 billion in 2002 to just over $1 billion in 2006.
Litigation
This drug has been the subject of litigation; more than 13,000 people have sued Wyeth between 2002 and 2009. Wyeth and Pharmacia & Upjohn prevailed in the vast majority of hormone therapy cases previously set for trial through a combination of rulings by judges, verdicts by juries, and dismissals by plaintiffs themselves. Of the company's losses, two of the jury verdicts were reversed post-trial and others are being challenged on appeal. Wyeth also won five summary judgments on Prempro cases and had 15 cases voluntarily dismissed by plaintiffs. The company won dismissals in another 3,000 cases. In 2006, Mary Daniel, in a trial in Philadelphia, was awarded $1.5 million in compensatory damages as well as undisclosed punitive damages. As of 2010, Wyeth had won the last four of five cases, most recently in Virginia, finding that they were not responsible for the breast cancer of plaintiff Georgia Torkie-Tork. Wyeth has been quoted as saying "many risk factors associated with breast cancer have been identified, but science cannot establish what role any particular risk factor or combination play in any individual woman's breast cancer." Wyeth's counsel in the case also noted that in the WHI trial, 99.62% of women took the drug and "did not get breast cancer".
Animal welfare
Animal welfare groups claim that animal husbandry and urine collection methods used in the production of CEEs cause undue stress and suffering to the mares involved. Animal activists have made claims of abuses ranging from inadequate stall size, long periods of confinement, cumbersome urine collection, and continuous breeding cycles. After reaching advanced age, many of the mares are adopted for recreation use, while some are sent to feed lots for slaughter. Despite the controversy, the USDA called the CEEs HRT industry a model of self-regulation.
Notes
References
Further reading
External links
WHI Follow-up Study Confirms Health Risks of Long-Term Combination Hormone Therapy Outweigh Benefits for Postmenopausal Women NIH press release, 4 March 2008
Antigonadotropins
Bioethics
Combination sex hormone drugs
Estranes
Estrogens
Hormonal antineoplastic drugs
Horse products
Ketones
Organic sodium salts
Sex hormone esters and conjugates
Prolactin releasers
Sulfate esters
Drugs developed by Wyeth
Drugs developed by Pfizer | Conjugated estrogens | [
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"Ketones",
"Functional groups",
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] |
47,602,799 | https://en.wikipedia.org/wiki/1-Hydroxypyrene | 1-Hydroxypyrene is a human metabolite. It can be found in urine of outdoor workers exposed to air pollution.
Biochemistry
Experiments in pig show that urinary 1-hydroxypyrene is a metabolite of pyrene, when given orally.
A Mycobacterium sp. strain isolated from mangrove sediments produced 1-hydroxypyrene during the degradation of pyrene.
Relationship with smoking
Highly significant differences and dose-response relationships with regard to cigarettes smoked per day were found for 2-, 3- and 4-hydroxyphenanthrene and 1-hydroxypyrene, but not for 1-hydroxyphenanthrene.
References
Human metabolites
Air pollution
Recreational drug metabolites
Smoking
Pyrenes
Hydroxyarenes | 1-Hydroxypyrene | [
"Chemistry"
] | 168 | [
"Organic compounds",
"Organic compound stubs",
"Organic chemistry stubs"
] |
47,603,597 | https://en.wikipedia.org/wiki/Behavioral%20strategy | Behavioral strategy refers to the application of insights from psychology and behavioral economics to the research and practice of strategic management. In one definition of the field, "Behavioral strategy merges cognitive and social psychology with strategic management theory and practice. Behavioral strategy aims to bring realistic assumptions about human cognition, emotions, and social behavior to the strategic management of organizations and, thereby, to enrich strategy theory, empirical research, and real-world practice" (Powell, Lovallo & Fox, 2011: 1371).
More specifically, behavioral strategy is as an approach to core issues in strategic management (e.g., CEO and top management team behaviors, entry decisions, competitive interaction, firm heterogeneity) with the following characteristics:
1) It is microfoundational (Felin, Foss, & Ployhardt, 2015) in the sense that a psychology-based understanding of the actions and interactions of individuals is used to explain strategy phenomena, often on a higher level of analysis;
2) all fields of psychology, as well as relevant parts of behavioral economics and sociology, are seen as potentially applicable to, in principle, any strategic management phenomenon;
3) assumptions about behaviors and interactions are to be based in evidence (e.g., brought about by means of experiments) rather than the extent to which these allow for mathematical tractability, are "elegant" or similar.
In terms of methods, behavioral strategy follows strategy research in general by being pluralist, such that qualitative research, lab and field experiments, and agent based modelling, in addition to conventional quantitative and formal methods are all acceptable. However, because of its heavy psychology-emphasis behavioral strategy research may be more disposed towards experiments than most other streams of strategy research.
Lines of study
Behavioural finance integrates psychological research that describes how people behave in real life and applies it to finance. This research resulted in the formation of two independent study lines:
The first is about how investor behavior may differ from the textbook definition of an efficient rational investor. The other is how investors who aren't completely rational can cause market prices to vary from their underlying values.
The first strand of research examines how investors act in order to determine how investing strategies should meet their desires. The second strand of research examines how investor behavior may influence market functioning; It's used to determine whether active investment managers will find it simpler to outperform (the short answer is "no").
In 2002, a professor of psychology, Daniel Kahneman, was awarded the Nobel Prize in Economics (who won it jointly with Matt Smith) in recognition of the contribution that behavioral analysis is now making in financial economics. This research arose from a series of experiments that yielded significant findings about the biases that influence how people make decisions and create preferences.
Giving investing advice requires a thorough grasp of investor preferences, and understanding investor biases is crucial for predicting how investors will react to specific events or developments. If biases are flaws that could harm an investor's interests, investing advisers should avoid catering to them. This, for example, implies a need for investor education. Investors and their advisers should be aware of these biases because they will influence how they react to various predicted market movements.
Major historical contributions
Herbert Simon's research on cognitive decision making and the concept of bounded rationality contributed to further research in decision making and behavioral strategy. Simon's research also led him to four categoric observations on variations in ability to solve complex problems and make decisions.
Simons Observations:
One key to solving problems lies within adequate representation of the problem. Those who show proficiency in solving problems, also represent the problem accurately, highlighting the nature of the problem and utilizing the most pertinent information necessary for a solution.
Effective problem solvers use patterns. When analyzing problems and their solutions, patterns emerge. These patterns translate to 'if/then' solutions. Porter's five Forces model is an example of 'if/then' solutions with recurring patterns that consistently connect problems with effective solutions. If your supplier has high bargaining power, then seek alternative sources, as an example.
Patterns increase memory encoding and recall. A connection to a memory allows faster recall from long term memory, and patterns increase this connection making memories easier to recall.
Practice increases expertise. Practicing decision making and problem solving correlates to increased skill. Using representation, recognizing and remembering patterns, and recalling these patterns increases one's abilities.
These observations provided early support in the development of research on behavioral strategy.
Development
The use of psychology insights to further research in the behavior and performance of firms has a long history, including research on the behavioral theory of the firm (Cyert & March, 1963; Gavetti, Levinthal, and Ocasio, 2007), aspirations (Greve, 1998), attention (Ocasio, 1997), emotions (Nickerson & Zenger, 2008), goals (Lindenberg & Foss, 2011), cognitive schema, maps, sensemaking, and cognitive rivalry (Porac and Thomas, 1990; Reger and Huff, 1993; Lant and Baum, 1995; Weick, 1995), routines (Cyert & March, 1963), decision theory (Kahneman and Lovallo, 1993), escalation (Staw and Cummings, 1981), motivation, (Foss & Weber, 2016), hubris (Bollaert and Petit, 2010), and top management teams (Hambrick and Mason, 1984), dominant logic (Prahalad & Bettis, 1986), competitive interaction (Chen, Smith & Grimm, 1992), and learning (Levinthal and March, 1993). (The Behavioral Strategy site https://www.behavioralstrategywiki.org/ organizes behavioral strategy papers by juxtaposing concepts (e.g., fairness, emotions, trust, etc.) and phenomena (e.g., global strategy, incentives, CSR, etc.)).
However, the first explicit use of the term "behavioral strategy" in a journal seems to be in Lovallo and Sibony (2010), which links the term to the behavioral economics literature and the underlying heuristics and biases literature. While Lovallo and Sibony (2010) is a contribution to a practitioner journal, Powell, Lovallo and Fox (2011) edited a special issue on "Psychological Foundations of Strategic Management" of the premier strategy journal, the Strategic Management Journal. Retrospectively, this may be seen as the key event in launching behavioral strategy as a coherent, institutionalized research effort rather than a multitude of relatively unconnected research streams.
In their editorial essay Powell et al. outline three reasons why there is a need for a concerted research effort in behavioral strategy, namely that strategy has been too slow to incorporate relevant results from psychology, lacks adequate psychological grounding (e.g., heterogeneity is assumed and not explained in terms of reasoning and decision-processes), but recent developments (e.g., cognitive neuroscience developments which make it possible to link strategic decision-making and brain activity) have paved the way for a closer and more coherent integration of the cognitive sciences and strategy.
In an article published the year after the Powell et al. article Rindova, Reger, and Dalpiaz (2012) refer to a "'sociocognitive' perspective" in strategy which, "while varied in its theoretical framings, focuses on the roles of managers' and observers' attention; the bounded rationality of their cognitions, intuitions, and emotions; and the use of biases and heuristics to socially construct "perceptual answers" to traditional strategic management questions about how firms obtain and sustain competitive advantage."
Representation in scholarly associations
In terms of institutionalization provided by professional and scholarly associations, behavioral strategy research has historically been represented in context of divisions and interest groups of the Academy of Management such as "Managerial and Organizational Cognition", "Business Policy and Strategy" (now "Strategic Management") and "Technology and Innovation Management" . In 2013, the "Behavioral Strategy Interest Group" was in the context of the Strategic Management Society.
Defining the field of behavioral strategy
The increasing interest in behavioral strategy has motivated a number of recent attempts to define the field (Powell et al., 2011; Rindova et al., 2012; Hambrick and Crossland, 2019) as well as surveys of theorizing that is either part of behavioral or very closely related, such as surveys of the behavioral theory of the firm (Gavetti, Levinthal, Greve, & Ocasio, 2012) or problemistic search (Posen et al., 2018). For example, Hambrick and Crossland adopt an imagery of alternatively sized tents of behavioral strategy. In the small tent conception, behavioral strategy is "a direct transposition of the logic of behavioral economics (and behavioral finance) to the field of strategic management," whereas in the middle-size conception it is "a commitment to understanding the psychology of strategists," and in the large tent conception it behavioral strategy is basically "all forms and styles of research that consider any psychological, social, or political ingredients in strategic management" (Hambrick and Crossland, 2019).
Behavioral strategy has developed gradually into a significant subfield within strategic management. It applies insights from social psychology and cognitive to intensify strategic decision-making by understanding social dynamics and human cognition. Behavioral strategy focuses on top managers’ cognitive processes and emphasizes collaboration and communication patterns. The foundation lies in the behavioral decision theory.
Strategic cognition delves into understanding the cognitive structures within organization and the decision-making processes. Effective and intuitive reasoning plays a significant role in strategy formulation, it comes to influence organizational and managerial cognition.
The field of Behavioral strategy has gained significant attention in academic circles, with issues and volumes dedicated to it in prestigious conferences and publications. The field remains scattered and diverse despite its growth. To address this issue scholars propose integrating theoretical and empirical attention. This integration aims to provide more understanding of how behavior can impact strategic outcomes.
(The study undertakes citation-based systematic literature review to provide a better understanding of behavioral strategy. It addresses the lack of reviews in literature, it aims to illuminate the key sources, contributors, and contribution in the field. Through network analysis and bibliometric, paper maps the network of authors, documents, growth patterns, influential articles, and intellectual structure of behavioral strategy. It identifies and suggests path for future research, it will serve as a valuable resource for researchers that are interested in this area.)
Applying behavioral strategy to extreme circumstances such as Covid 19 and the implications
Behavioral strategy affected decisions made during the COVID-19 disruption. Behavioral strategy provides psychologically based interpretations that can illuminate how individuals and organizations respond to such disruptions. It suggests that strategists may not be good at using formal models, rules, or forecasts because they are not statisticians. There is supporting evidence of this observed during the disruption caused by Covid-19. Some decision-makers treated extreme model projections as deterministic predictions rather than recognizing them as improbable worst-case scenarios. An example of this was the societal lockdown. It was impossible to forecast the economic and social consequences of the lockdown, and its effectiveness, and yet decision-makers decided to implement this worst-case scenario. Another example of worst-case scenario being implemented is when the CDC gave guidance on wearing masks outdoors as this was an example of extreme caution. Decision-makers appeared to overlook the consequences of or misunderstand the lack of error margins around initial forecasts. Also of relevance, decision-makers may rely too much on models, forecasts, and data that are available. When decision-making problems are ill-structured and require quick action, relying solely on formal models and forecasts can be problematic. It becomes necessary to incorporate intuition and soft data into the decision-making process in these cases.
Limitations of behavioral strategy
Strategy making is a deeply social process and strategy research doesn't sufficiently account for this. Different experts' social standards vary, and this will influence what information is collected. COVID-19 highlighted how behavioral strategy frameworks don’t allow dealing with uncertainty beyond standard treatments of risky decision-making. Behavioral strategy is useful in extreme circumstances, however, there is more research to be done on the weaknesses present for disruptions like this.
See also
References
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Chen, M-J., Smith, Ken G., & Grimm, Curtis M. 1992. Action Characteristics as Predictors of Competitive Responses. Management Science. 38(3): 307–458.
Cyert, Richard M. & March, James G. 1963. A Behavioral Theory of the Firm. University of Illionois at Urbana-Champaign's Academy for Entrepreneurial Leadership Historical Research Reference in Entrepreneurship.
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Foss, N.J. & Weber, L. 2016. Putting Opportunism in the Back Seat: Bounded Rationality, Costly Conflict and Hierarchical Forms. Academy of Management Review, 41: 41–79.
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Hambrick, Donald C. & Mason, Phyllis A. 1984. Upper Echelons: The Organization as a Reflection of Its Top Managers. The Academy of Management Review. 9 (2): 193–206.
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Kruglanski, A. W., & Kopetz, C. 2009. What is so special (and nonspecial) about goals? A view from the cognitive perspective. In G. B. Moskowitz & H. Grant, eds., The psychology of goals (p. 27–55). Guilford Press.
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Lindenberg, S. & Foss, N.J. 2011. Managing Motivation for Joint Production: The Role of Goal Framing and Governance Mechanisms. Academy of Management Review 36: 500–525.
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Prahalad, C. K. & Bettis, Richard A. 1986. The dominant logic: A new linkage between diversity and performance. Strategic Management Journal 7(6): 485–501.
Reger, Rhonda K. & Huff, Anne Sigismund. 1993. Strategic groups: A cognitive perspective. Strategic Management Journal. 14(2): 103–123.
Rindova, Violina P., Reger, Rhonda K., & Dalpiaz, Elena. 2012. The mind of the strategist and the eye of the beholder: The Socio-cognitive perspective in strategy research. In G.B. Dagnino, eds., Handbook of Research on Comptetive Strategy. Edward Elgar Publishing.
Ryan, Richard M. & Deci, Edward L. 2017. Self-Determination Theory: Basic Psychological Needs in Motivation, Development, and Wellness. Guildford Publications.
Seminowicz, D.A., Mikulis, D. J.; Davis, K. D. 2004. Cognitive modulation of pain-related brain responses depends on behavioral strategy. Pain 112(1): 48–58.
Staw, Barry M & Cummings, Larry L. 1981. Research in Organizational Behavior. JAI Press.
Weick, Karl E.1995. Sensemaking in Organizations. Sage Publications. University of Michigan.
External links
Behavioral Economics The Behavioral Economics Guide
Behavioral Finance Overview of Behavioral Finance
Applied psychology
Behavioral finance
Financial economics
Market trends
Prospect theory | Behavioral strategy | [
"Biology"
] | 3,840 | [
"Human behavior",
"Behavior",
"Behavioral economics",
"Behaviorism",
"Behavioral finance"
] |
47,603,644 | https://en.wikipedia.org/wiki/ShakeAlert | ShakeAlert is an earthquake early warning system (EEW) in the United States, developed and operated by the United States Geological Survey (USGS) and its partners. As of 2021, the system issues alerts for the country's West Coast (specifically the states of California, Oregon and Washington). It is expected that the system will be expanded to other seismically active areas of the United States in the future. ShakeAlert is one of two EEW systems available in the United States, with Google's Android Earthquake Alerts System being the other.
Similar to other earthquake early warning systems, ShakeAlert does not predict earthquakes, but rather it attempts to quickly identify a seismic event and issue an alert before widespread shaking is felt. It does this by detecting an earthquake's fast moving (but weak) P waves, then computes the event's location and estimated magnitude, after which it issues the warning. Depending on a person's distance from the earthquake's epicenter, the alert may reach them before the earthquake's slower moving (but destructive) S waves do. These warnings can provide time for persons to take protective actions, such as "drop, cover, and hold," and for organizations to shut down transit systems, equipment, open fire station doors, and trigger specific protocols in hospitals and other sensitive work environments.
Research and development of the system began in 2006 and by the fall of 2018, the system was considered "sufficiently functional and tested" to enter phase 1 and begin issuing alerts for the West Coast states. While the warnings are generated by ShakeAlert, USGS does not send the alerts directly, instead relying on various private and public partners to distribute the messages through systems such as Wireless Emergency Alerts (WEA) and mobile apps. A statewide alert distribution system went online in California on October 17, 2019, in Oregon on March 11, 2021, and in Washington on May 4, 2021.
Development
Initially the system has been developed to monitor and alert the West Coast of the United States, an area with significant seismic risk due to the San Andreas fault zone and the Cascadia subduction zone. The West Coast system was developed by a consortium of institutions including the United States Geological Survey, the California Governor's Office of Emergency Services (Cal OES), the California Geological Survey, California Institute of Technology, the Berkeley Seismological Laboratory at University of California, Berkeley, University of Washington, University of Oregon, and the Swiss Federal Institute of Technology in Zürich (ETHZ).
Research and development of the West Coast system (initially called CISN ShakeAlert) began in August 2006, becoming demonstrable in August 2009. In 2011, test users (mostly other seismologists) were able to access the system through the "UserDisplay" software. In January 2012, "beta" users were able to access the alerts in California. In February 2015, "beta" users were able to access the alerts in Oregon and Washington. In February 2016, the system moved from demonstrable to Production Prototype version 1.0 in California, providing alerts to "pilot" users. In April 2017, Production Prototype version 1.2 went live, expanding the prototype to Oregon and Washington "pilot" users. (Until this time, the Oregon/Washington system had been developed and operated separately from the California system.) On September 28, 2018, version 2.0 went live, allowing the "sufficiently functional and tested" system to begin Phase 1 of alerting California, Oregon and Washington.
Even though ShakeAlert could alert the public beginning in September 2018, the messages themselves could not be distributed until the various private and public distribution partners had completed mobile apps and made changes to various emergency alerting systems. The first publicly available alerting system was the ShakeAlertLA app, released on New Year's Eve 2018 (although it only alerted for shaking in the Los Angeles area). On October 17, 2019—the thirtieth anniversary of the Loma Prieta earthquake— announced a statewide rollout of the alert distribution system in California. California refers to their system as the California Earthquake Early Warning System.
On March 11, 2021, a statewide alert distribution system was rolled out in Oregon. Rollout of the alert system for the West Coast was completed when a statewide alert distribution system went live in Washington on May 4, 2021.
Future plans
Of the 1,675 seismic stations needed for full implementation of the West Coast system, only 1,115 had been built or funded by April 2018 (67% of the total needed). The project continues to solicit property owners for permission to place new seismic stations.
Following the 2020 Salt Lake City earthquake, local media reported that Utah was the next state in line to get ShakeAlert.
Funding
In 2014, USGS estimated that the West Coast system would cost $38 million to complete and $16 million per year (equivalent to $
and $ in , respectively) to operate over and above the investment that had already been made in earthquake monitoring. By 2018, the estimates for the system's cost had grown to $39.4 million for the initial build out and $28.6 million for yearly maintenance and operation (equivalent to $ and $ in , respectively).
In December 2014, $5 million was added to the USGS budget for ShakeAlert development (equivalent to $ in ). This enabled USGS to purchase $1 million in seismic instrumentation and award $4 million in funding to the project partners to make the demonstration system more robust. In 2015, more than 30 Congress members signed a joint letter urging the President to add full funding for the system to his federal budget request. The Gordon and Betty Moore Foundation has invested more than $6 million in developing the system.
Neighboring systems
In August 2024, the Canadian Earthquake Early Warning system was launched by Natural Resources Canada (NRCan); this system was developed in cooperation with USGS and is based on the same software as ShakeAlert. While the two systems are distinct, USGS and NRCan share processing software, algorithms and real-time data.
Detection methods
Full implementation of ShakeAlert on the West Coast system will require 1,675 seismic stations—1,115 in California and 560 in Oregon and Washington. These stations include sensors, such as seismometers, which are part of USGS's Advanced National Seismic System. During an earthquake, the stations send data to processing infrastructure in monitoring centers which, using various algorithms, are able to calculate the necessary information and generate alerts when needed.
Initially, ShakeAlert processing centers were capable of detecting earthquakes at an early stage because of three specific algorithms. The first algorithm was ElarmS. Also known as Earthquake Alarm Systems, these signals detect the P wave energy released during an earthquake. This energy, while given off quite early, does not usually cause damage. It was also the ElarmS that were responsible for roughly estimating the geographical location and size of the earthquake. Following these Elarms, empirical attenuation relations estimated how much the earth would shake in the specified region of the quake. The second algorithm was the - OnSite algorithm. By using displacement amplitude and period of the first signs of shaking, the OnSite algorithm more accurately predicted the intensity and size of the earthquake than ElarmS did. The tradeoff of using these algorithms for the earliest detection possible meant having a less reliable approach than regional warning algorithms, however some argued that the added seconds to prepare are more important than reliability. Lastly, the Virtual Seismologist, known as the VS method, imitated the analysis of a human scientist in terms of capacity, but did so at a faster rate. A Bayesian framework was used with inputs of acceleration, velocity, and displacement. The last step required of all these algorithms is to come together in a decision module. This decision module broadcast the probability, size, and other characteristics of the earthquake.
As of 2018, all three of these algorithms have been replaced with two new algorithms – earthquake point-source integrated code (EPIC) and finite-fault detector (FinDer).
In 2024, Global Navigation Satellite System (GNSS) data was added to ShakeAlert to aid in the characterization of large magnitude earthquakes. The algorithm, GFAST (Geodetic First Approximation of Size and Timing), uses the peak ground displacement recorded at permanent GPS stations to determine magnitude. GFAST was developed by researchers from the Pacific Northwest Seismic Network at University of Washington. GFAST receives initial earthquake source information (origin time and epicenter) from EPIC or FinDer. Considerable logic was added to ShakeAlert to combine magnitude estimates from all three ShakeAlert algorithms to ensure robustness of solutions.
Alert distribution
ShakeAlert warnings are sent to both institutional users and the general public through a variety of distribution methods; this includes messages via cell phones, television and radio. These alerts may give people time to take protective actions like "drop, cover and hold on", preventing injuries caused by falling debris. Various automated systems can listen for the alerts and stop public transport systems, prevent cars from entering bridges or tunnels, automatically shut down industrial systems and gas lines, and trigger specific protocols in hospitals and other sensitive work environments.
Institutional users
Bay Area Rapid Transit (BART) was an early user of ShakeAlert, initially connecting to the system in 2012 (when it was still in development). BART uses the system to automatically brake its trains when shaking threatens the San Francisco Bay Area.
By 2015, organizations enrolled in the beta test user program included: Warning Center, LA County Fire, , Amgen, LADWP, Metrolink, CalTrans and Disneyland. Additional institutional users were able to access alerts from the system, after ShakeAlert version 2.0 went live at the end of September 2018.
Cell phone alerts
Mobile apps
As of 2023, there are two mobile apps licensed to work with ShakeAlert: MyShake, developed by UC Berkeley, and SD Emergency, developed by San Diego County.
MyShake
MyShake was released in February 2016. Initially the app did not issue alerts, but instead used a phone's accelerometers to record shaking from an earthquake and send the data back to UC Berkeley for analysis, thereby creating a crowdsourced global seismic network. On October 17, 2019, a new version of the app was announced, which would also provide alerts from ShakeAlert to users in California, while allowing users outside the state to continue being part of the crowdsourced global network. The app began providing earthquake alerts in Oregon on March 11, 2021 and in Washington state on January 26, 2022.
MyShake only delivers alerts for earthquakes exceeding MW4.5 and that will produce a shaking intensity greater than three.
SD Emergency
On August 26, 2021, officials from the County of San Diego and USGS announced that the "ShakeReadySD" feature had been added to the county's SD Emergency app, which would provide ShakeAlert warnings throughout California.
Former apps
QuakeAlertUSA
QuakeAlertUSA had been under development (and open to beta users), by Early Warning Labs, LLC, for several years before being publicly released on January 21, 2020 (at which time it only provided earthquake alerts in California). The app began providing earthquake alerts in Oregon on March 11, 2021. The QuakeAlertUSA app was decommission on November 6, 2023, so that the company could focus on its commercial earthquake response services.
QuakeAlertUSA delivered alerts for earthquakes exceeding MW4.5 and that produced a shaking intensity greater than three. (Settings could be changed to require higher intensity earthquakes before alerting the user.)
ShakeAlertLA
ShakeAlertLA, was developed by the City of Los Angeles and AT&T. This app, which only warned of shaking in the Los Angeles County area, was made available to the general public at the end of 2018, but was retired after December 31, 2020.
Wireless Emergency Alerts
In the United States, the Wireless Emergency Alerts (WEA) system is used to disseminate emergency alerts (such as AMBER alerts) to compatible mobile devices within a predefined area. ShakeAlert is capable of sending alerts to the Integrated Public Alert and Warning System (run by the Federal Emergency Management Agency), which then—through the WEA system—distributes messages to phone service providers who ultimately deliver the alert to their customers' devices.
WEA alerts are simple text messages, unlike the alerts sent by some mobile apps (as select apps include graphics with estimated intensity and arrival time of shaking). WEA alerts may also arrive more slowly than alerts from apps. Although unlike apps which must be downloaded, phones can receive WEA alerts automatically as long as emergency alerts are turned on in the device's settings.
ShakeAlert messages have been delivered via WEA in California since October 17, 2019, in Oregon since March 11, 2021, and in Washington since May 4, 2021.
WEA alerts are only sent for MW5.0 or larger earthquakes.
Push notifications
On August 11, 2020, Google announced that it had partnered with USGS, allowing its Android operating system to distribute ShakeAlerts for California. The alerts are displayed using the operating system's built-in notification feature, which does not require an app or a message from the WEA system. The feature was also rolled out on March 11, 2021, in Oregon, and in Washington in the days following May 4, 2021.
As of 2021, Apple's iOS does not include a similar built-in notification system for ShakeAlert. Conversations between USGS and Apple have occurred, but no resolution has been reached. However, these devices can still receive earthquake alerts through WEA messaging, or, depending on the state, through apps.
Past performance
Events during system development
2014 California earthquakes
The system issued alerts for several significant southern California earthquakes in 2014 including a MW4.4 event in Encino, a MW4.2 event in Westwood, and a MW5.1 event in La Habra.
It also issued a warning 5.4 seconds after the beginning of the MW6.0 South Napa earthquake that hit the Napa region on August 24, 2014. Although it was initially reported that the system provided 10 seconds of warning before the S wave arrived in Berkeley, subsequent information showed that this was in error and the warning arrived 5 seconds before the S wave in Berkeley. This means the S waves had already arrived in Napa and Vallejo when the warning was issued. San Francisco received 8 seconds warning.
2019 Ridgecrest earthquakes
ShakeAlert generated warnings for both the July 5 MW6.4 and July 5 MW7.1 Ridgecrest earthquakes.
Although not yet publicly available, beta users of the QuakeAlert mobile app received warnings on their phones. On average, the app's beta users received a warning of 45 seconds for both earthquakes. The only publicly available app (at the time), ShakeAlertLA, did not send an alert during the earthquakes. According to the City of Los Angeles, the system did not send alerts due to the estimated shaking in the Los Angeles area being below the activation threshold.
Events following general availability
2019 Cholame earthquake
On December 17, 2019, the then recently released MyShake app sent its first alert for a MW4.3 earthquake in the Cholame Valley. (Even though the earthquake was below the MW4.5 threshold, a warning was still transmitted through the app, because preliminary readings measured the magnitude as 4.8.) No Wireless Emergency Alert was transmitted because the magnitude of the earthquake was below the 5.0 threshold.
2021 Antelope Valley earthquake
The 2021 Antelope Valley earthquake occurred in a rural area near the California–Nevada border. Due to the remoteness of the area, there were few sensor stations near the earthquake and this resulted in the MW6.0 earthquake incorrectly being split into "phantom quakes" by the system – a MW4.8 near Lee Vining, MW4.8 near Stockton, and MW4.3 near Mammoth Lakes. Additionally, it took the system 25 seconds to declare an earthquake and issue an alert. While mobile apps received the alert, the warning was for an earthquake identified as MW4.8 near Stockton (an incorrect magnitude and location). No Wireless Emergency Alert was transmitted because the system initially estimated the magnitude to be below the required MW5.0 threshold (finalized reports showed the earthquake had actually exceeded the threshold for a WEA alert).
2022 Ferndale earthquake
About 270,000 phones were alerted during the magnitude 6.4 December 2022 Ferndale earthquake.
See also
Earthquake Early Warning (Japan)
References
External links
Earthquake Warning California
MyShake
SD Emergency
ShakeAlert—Earthquake Early Warning. How does it work? – IRIS Consortium
Earthquake early warning systems
Earthquake engineering
United States Geological Survey
Emergency population warning systems | ShakeAlert | [
"Technology",
"Engineering"
] | 3,474 | [
"Structural engineering",
"Earthquake engineering",
"Emergency population warning systems",
"Civil engineering",
"Warning systems"
] |
47,603,674 | https://en.wikipedia.org/wiki/Flark | A flark is a depression or hollow within a bog. Flarks typically occur as a series of parallel depressions, separated by intervening ridges known as strings.
Early theories suggested that flarks were formed by frost heaving, but flarks have since been found in areas where frost heaving does not occur. Flarks are now thought to form when the peat that forms the base of the bog becomes so thick that it slides downslope due to its own weight. Irregularities in the underlying terrain halt the slide of the peat, causing flarks to form downslope from the obstruction as the downslope peat tears away from the portion of the peat mass held back by the underlying obstruction. Another theory suggests that flarks are formed by areas within the bog which experience accelerated rates of decay, causing depressions in the bog.
References
Bogs
Landforms
Types of soil
Wetlands
Pedology | Flark | [
"Environmental_science"
] | 184 | [
"Hydrology",
"Wetlands"
] |
47,605,419 | https://en.wikipedia.org/wiki/V4650%20Sagittarii | V4650 Sagittarii (qF362) is a luminous blue variable star (LBV) in the constellation of Sagittarius. Located some 25,000 light years away, the star is positioned on the edge of a starburst cluster known as the Quintuplet cluster.
Discovery
V4650 Sgr was first catalogued in 1996 as star 362 in a list of stars in the galactic centre region near the Quintuplet Cluster. The acronym qF is used for stars in the list and so the star name is qF 362. The acronym FMM is also used, hence FMM 362. The LBV nature of qF 362 was not recognised until 1999. It is one of three LBVs close to the Quintuplet Cluster, all highly luminous stars.
V4650 was discovered using infrared telescopes. It is extremely faint at optical wavelengths due to interstellar extinction. The 2MASS survey recorded it at 17th magnitude in red light and 19th magnitude in blue light, while it is a 7th magnitude object in K band infrared.
Properties
V4650 Sgr is calculated to be one of the most luminous stars known, at to . It is considered to be a bona-fide luminous blue variable, although it has not been observed to change temperature from the S Doradus minimum strip to a cooler outburst state. The infrared brightness has varied between magnitude 7.0 and 7.9. It is calculated to have a temperature of 11,300 K and a radius of . Unlike both the two nearby LBVs, V4650 Sgr has no detectable associated nebulosity.
References
Luminous blue variables
Sagittarius (constellation)
Sagittarii, V4647
J17461798-2849034 | V4650 Sagittarii | [
"Astronomy"
] | 366 | [
"Sagittarius (constellation)",
"Constellations"
] |
47,605,998 | https://en.wikipedia.org/wiki/Multipolar%20exchange%20interaction | Magnetic materials with strong spin-orbit interaction, such as: LaFeAsO, PrFe4P12, YbRu2Ge2, UO2, NpO2, Ce1−xLaxB6, URu2Si2 and many other compounds, are found to have magnetic ordering constituted by high rank multipoles, e.g. quadruple, octople, etc. Due to the strong spin-orbit coupling, multipoles are automatically introduced to the systems when the total angular momentum quantum number J is larger than 1/2. If those multipoles are coupled by some exchange mechanisms, those multipoles could tend to have some ordering as conventional spin 1/2 Heisenberg problem. Except the multipolar ordering, many hidden order phenomena are believed closely related to the multipolar interactions
Tensor operator expansion
Basic concepts
Consider a quantum mechanical system with Hilbert space spanned by , where is the total angular momentum and is its projection on the quantization axis. Then any quantum operators can be represented using the basis set as a matrix with dimension . Therefore, one can define matrices to completely expand any quantum operator in this Hilbert space. Taking J=1/2 as an example, a quantum operator A can be expanded as
Obviously, the matrices: form a basis set in the operator space. Any quantum operator defined in this Hilbert can be expended by operators. In the following, let's call these matrices as a super basis to distinguish the eigen basis of quantum states. More specifically the above super basis can be called a transition super basis because it describes the transition between states and . In fact, this is not the only super basis that does the trick. We can also use Pauli matrices and the identity matrix to form a super basis
Since the rotation properties of follow the same rules as the rank 1 tensor of cubic harmonics and the identity matrix follows the same rules as the rank 0 tensor , the basis set can be called cubic super basis. Another commonly used super basis is spherical harmonic super basis which is built by replacing the to the raising and lowering operators
Again, share the same rotational properties as rank 1 spherical harmonic tensors , so it is called spherical super basis.
Because atomic orbitals are also described by spherical or cubic harmonic functions, one can imagine or visualize these operators using the wave functions of atomic orbitals although they are essentially matrices not spatial functions.
If we extend the problem to , we will need 9 matrices to form a super basis. For transition super basis, we have . For cubic super basis, we have . For spherical super basis, we have . In group theory, are called scalar or rank 0 tensor, are called dipole or rank 1 tensors, are called quadrupole or rank 2 tensors.
The example tells us, for a -multiplet problem, one will need all rank tensor operators to form a complete super basis. Therefore, for a system, its density matrix must have quadrupole components. This is the reason why a problem will automatically introduce high-rank multipoles to the system
Formal definitions
A general definition of spherical harmonic super basis of a -multiplet problem can be expressed as
where the parentheses denote a 3-j symbol; K is the rank which ranges ; Q is the
projection index of rank K which ranges from −K to +K. A cubic harmonic super basis where all the tensor operators are hermitian can be defined as
Then, any quantum operator defined in the -multiplet Hilbert space can be expanded as
where the expansion coefficients can be obtained by taking the trace inner product, e.g. .
Apparently, one can make linear combination of these operators to form a new super basis that have different symmetries.
Multi-exchange description
Using the addition theorem of tensor operators, the product of a rank n tensor and a rank m tensor can generate a new tensor with rank n+m ~ |n-m|. Therefore, a high rank tensor can be expressed as the product of low rank tensors. This convention is useful to interpret the high rank multipolar exchange terms as a "multi-exchange" process of dipoles (or pseudospins). For example, for the spherical harmonic tensor operators of case, we have
If so, a quadrupole-quadrupole interaction (see next section) can be considered as a two steps dipole-dipole interaction. For example, , so the one step quadrupole transition on site now becomes a two steps of dipole transition . Hence not only inter-site-exchange but also intra-site-exchange terms appear (so called multi-exchange). If is even larger, one can expect more complicated intra-site-exchange terms would appear. However, one has to note that it is not a perturbation expansion but just a mathematical technique. The high rank terms are not necessarily smaller than low rank terms. In many systems, high rank terms are more important than low rank terms.
Multipolar exchange interactions
There are four major mechanisms to induce exchange interactions between two magnetic moments in a system: 1). Direct exchange 2). RKKY 3). Superexchange 4). Spin-Lattice. No matter which one is dominated, a general form of the exchange interaction can be written as
where are the site indexes and is the coupling constant that couples two multipole moments and . One can immediately find if is restricted to 1 only, the Hamiltonian reduces to conventional Heisenberg model.
An important feature of the multipolar exchange Hamiltonian is its anisotropy. The value of coupling constant is usually very sensitive to the relative angle between two multipoles. Unlike conventional spin only exchange Hamiltonian where the coupling constants are isotropic in a homogeneous system, the highly anisotropic atomic orbitals (recall the shape of the wave functions) coupling to the system's magnetic moments will inevitably introduce huge anisotropy even in a homogeneous system. This is one of the main reasons that most multipolar orderings tend to be non-colinear.
Antiferromagnetism of multipolar moments
Unlike magnetic spin ordering where the antiferromagnetism can be defined by flipping the magnetization axis of two neighbor sites from a ferromagnetic configuration, flipping of the magnetization axis of a multipole is usually meaningless. Taking a moment as an example, if one flips the z-axis by making a rotation toward the y-axis, it just changes nothing. Therefore, a suggested definition of antiferromagnetic multipolar ordering is to flip their phases by , i.e. . In this regard, the antiferromagnetic spin ordering is just a special case of this definition, i.e. flipping the phase of a dipole moment is equivalent to flipping its magnetization axis. As for high rank multipoles, e.g. , it actually becomes a rotation and for it is even not any kind of rotation.
Computing coupling constants
Calculation of multipolar exchange interactions remains a challenging issue in many aspects. Although there were many works based on fitting the model Hamiltonians with experiments, predictions of the coupling constants based on first-principle schemes remain lacking. Currently there are two studies implemented first-principles approach to explore multipolar exchange interactions. An early study was developed in 80's. It is based on a mean field approach that can greatly reduce the complexity of coupling constants induced by RKKY mechanism, so the multipolar exchange Hamiltonian can be described by just a few unknown parameters and can be obtained by fitting with experiment data. Later on, a first-principles approach to estimate the unknown parameters was further developed and got good agreements with a few selected compounds, e.g. cerium momnpnictides. Another first-principle approach was also proposed recently. It maps all the coupling constants induced by all static exchange mechanisms to a series of DFT+U total energy calculations and got agreement with uranium dioxide.
References
Magnetic ordering
Magnetic exchange interactions | Multipolar exchange interaction | [
"Physics",
"Chemistry",
"Materials_science",
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47,606,353 | https://en.wikipedia.org/wiki/Leohumicola%20levissima | Leohumicola levissima is a species of fungus. It is named after the smooth walled appearance of its terminal conidial cells ( is Latin for "smooth"). It was first found in Crater Lake National Park, Oregon. The terminal cell of this species’ conidia remains smooth even after 3 months’ time, as opposed to the encrusted terminal cells of L. verrucosa and L. incrustata. Conidia of L. atra have similarly smooth terminal cells, but which are darker.
Description
Its conidiogenous hyphae are hyaline, measuring approximately 1–2 μm wide, often found in fascicles in aerial mycelium. These are reduced to a single denticle that is 0.5–1.5 μm long and 1.0–3.5 μm wide. Conidia are two-celled, either solitary or distributed side by side in clusters. Its terminal cell is 4.5–6.0 by 4.0–5.5 μm, being globose to subglobose, transitioning to a dark brown colour; its conidial walls are slightly thick. Chlamydospores are sparsely produced, being intercalary, single, and the same colour as the conidial terminal cell. The vegetative mycelium often carry swollen, monilioid hyphae that are 1 to 2 μm wide, septate, and show thickened walls.
References
Further reading
Chen, Juan, et al. "Leohumicola, a genus new to China." Mycotaxon 108.1 (2009): 337–340.
Leotiomycetes
Fungal plant pathogens and diseases
Fungus species | Leohumicola levissima | [
"Biology"
] | 362 | [
"Fungi",
"Fungus species"
] |
47,606,437 | https://en.wikipedia.org/wiki/Microbotryum%20silenes-dioicae | Microbotryum silenes-dioicae is a species of fungus first isolated from Brittany, France. Its name refers to its host species, Silene dioica. The fungus is the cause of anther-smut disease, which results in fungal spores replacing the pollen in the anthers. The species that most resembles ‘’M. silenes-dioicae’’ morphologically is M. lychnidis-dioicae.
Description
This species shows sori arranged in anthers. Its spore mass is powdery and brown. The spores are mainly globose, subglobose or ellipsoidal, measuring 6.5–10.5 by 5.5–9.0 μm and being pale coloured. The spore wall is reticulate, presenting 6–8 meshes per spore diameter, the latter being irregularly polygonal.
In culture
In 1869, the English suffragette Lydia Becker presented to the British Association for the Advancement of Science her theory that the fungus causes female flowers of its host to become hermaphroditic, informing her later work in gender studies.
References
Further reading
Abbate, J. L., and M. E. Hood. "Dynamic linkage relationships to the mating‐type locus in automictic fungi of the genus Microbotryum." Journal of Evolutionary Biology 23.8 (2010): 1800–1805.
Vercken, Elodie, et al. "Glacial refugia in pathogens: European genetic structure of anther smut pathogens on Silene latifolia and Silene dioica." PLoS Pathog 6 (2010): e1001229.
Gladieux, Pierre, et al. "Maintenance of fungal pathogen species that are specialized to different hosts: allopatric divergence and introgression through secondary contact." Molecular Biology and Evolution 28.1 (2011): 459–471.
External links
Mycobank
Fungal plant pathogens and diseases
Microbotryales
Fungi described in 2009
Fungus species | Microbotryum silenes-dioicae | [
"Biology"
] | 426 | [
"Fungi",
"Fungus species"
] |
59,519,520 | https://en.wikipedia.org/wiki/NGC%20732 | NGC 732 is a lenticular galaxy located 250 million light-years away in the constellation Andromeda. It was discovered by astronomer Édouard Stephan on December 5, 1883 and is a member of Abell 262.
2017fpt
On July 20, 2017, a type Ia supernova designated as 2017fpt was discovered in NGC 732.
See also
List of NGC objects (1–1000)
References
External links
732
007270
Andromeda (constellation)
Astronomical objects discovered in 1883
Lenticular galaxies
Abell 262
01406
Discoveries by Édouard Stephan
Markarian galaxies | NGC 732 | [
"Astronomy"
] | 118 | [
"Andromeda (constellation)",
"Constellations"
] |
59,520,971 | https://en.wikipedia.org/wiki/Ardenticatena | Ardenticatena is a Gram-negative, thermophilic and chemoheterotrophic genus of bacteria from the family of Ardenticatenaceae with one known species (Ardenticatena maritima). Ardenticatena maritima has been isolated from iron-rich sediments from a coastal hydrothermal field from Kagoshima in Japan.
See also
List of bacteria genera
List of bacterial orders
References
Chloroflexota
Bacteria genera
Monotypic bacteria genera | Ardenticatena | [
"Biology"
] | 98 | [
"Bacteria stubs",
"Bacteria"
] |
59,521,014 | https://en.wikipedia.org/wiki/Misuse%20of%20Drugs%20%28Medicinal%20Cannabis%29%20Amendment%20Act%202018 | The Misuse of Drugs (Medicinal Cannabis) Amendment Act 2018 (2018 No 54) is an Act of Parliament in New Zealand which amends the Misuse of Drugs Act 1975 to allow terminally-ill people to consume cannabis and to possess a cannabis utensil. The bill passed its third reading on 11 December 2018. It was supported by the centre-left Labour Party and its coalition partners New Zealand First and the Green parties but was opposed by the opposition centre-right National Party. The Act received royal assent on 17 December and came into force on 18 December 2018.
Legislative features
The Misuse of Drugs (Medicinal Cannabis) Amendment Act amends the Misuse of Drugs Act 1975 to:
introduce an exception and a statutory defence for those requiring palliative care to possess and use illicit cannabis and to possess a cannabis utensil;
provide a regulation-making power to enable the setting of standards that products manufactured, imported, and supplied under licence must meet; and
amend Schedule 2 of the Act so that cannabidiol (CBD) and CBD products are no longer classed as controlled drugs.
This Act intends to improve access to both medicinal cannabis and medicinal cannabis products of a quality standard. Cannabis compounds that are still classified as controlled drugs are tetrahydrocannabinols and related psychoactive substances.
Both the populist New Zealand First and the left-wing Green Party secured concessions to the Amendment Act including the inclusion of anyone in palliative care rather than those defined as terminally ill and the establishment of a regulated local market that allows native strains of cannabis rather than imported cannabis products. The Minister of Health David Clark has also confirmed that medicinal cannabis products will be available on prescription.
However, no individual may leave or enter New Zealand with illicit cannabis even if they have been diagnosed by a medical or nurse practitioner as requiring palliation. Individuals can still travel with one month's supply of medicines that are controlled drugs such as Sativex or three months' supply of medicines that are not controlled drugs (CBD products) provided they are able to show that the drugs have been lawfully supplied to them.
History
Introduction
The Misuse of Drugs (Medicinal Cannabis) Amendment Bill was first introduced on 30 January 2018 by Health Minister David Clark. It passed its first reading and was referred to the parliamentary Health Committee. At that stage, the Bill was supported by both the Labour-led coalition government and the opposition centre-right National Party. This Bill is not to be confused with Green MP Chlöe Swarbrick's similarly named Misuse of Drugs (Medical Cannabis and Other Matters) Amendment Bill, which did not pass its first reading on 31 January.
Health Committee report
On 24 July 2018, the National Party withdrew its support for the Government's Bill and proposed its own an alternative bill which it claimed would set out a more comprehensive and well-researched regime regulating medicinal cannabis. National MP Shane Reti's bill proposed allowing medicinal cannabis products with the exception of loose leaf cannabis to be regulated the same way as medicine, classifying medicinal cannabis as pharmacist–only medicine, and giving doctors the right to issue identification cards that would allow patients to purchase medicinal cannabis. Health Minister Clark opposed the bill, claiming National was playing politics.
On 25 July, the parliamentary Health Committee released its report to Parliament. Since the Committee was unable to reach an agreement on the Bill, it was unable to recommend the passage of the bill. The Health Committee received 1,786 written submissions on the bill with the vast majority expressing support for legalising medicinal cannabis. Only 1% opposed the intents of the bill. The Health Committee also heard 158 oral submissions, which were largely supportive of the bill. Submitters' concerns included expanding access to those with other medical conditions, the regulation of medicinal cannabis products, lack of a clear definition of terminal illnesses, and calls for a full risk assessment of cannabidioil.
The Ministry of Health also recommended several amendments included providing a legal defence for the terminally ill to possess cannabis; setting regulations to prescribe standards for all stages of cultivation, production, and manufacture of cannabis; to allow the Director-General of Health to communicate information about the availability of medicinal cannabis products; maintaining a prohibition on tetrahydrocannabinols capable of inducing a psychoactive effect on individuals, and allowing CBD products to contain some non-psychoactive cannabinoids that are naturally found in cannabis. The Labour Party expressed support for the bill as a means of decriminalizing medicinal cannabis. While the National Party supported making medicinal cannabis more easily accessible, it expressed concerns about the wording of the bill and the manufacture, distribution, and eligibility of medicinal cannabis products.
The cannabis law reform organization NORML New Zealand issued a submission voicing support for descheduling CBD products but allowing a wider 5% tolerance for other cannaboids to improve production and affordability; broadening the defence to include patients with terminal illnesses, chronic or debilitating medical conditions where the doctor has prescribed the use of cannabis; allowing the cultivation of cannabis; and taking a herbal remedy approach towards non-pharmaceutical cannabis products. While supportive of the Government's proposed Medicinal Cannabis Access Scheme, it advocated a "patient-focused regime" that allowed local cultivation as opposed to what it termed a "corporate pharmaceutical-style scheme."
Second Reading
Following the Health Committee's report, the Bill passed its second reading on 29 November 2018. The Bill was supported by the ruling coalition parties and National, which had reversed its previous opposition on the condition that some of its own legislation including those pertaining to banning of smoking "loose-leaf" cannabis be incorporated into the final bill. During its second reading, the revised Bill incorporated several changes including extending the use of medicinal cannabis to all needing palliative care; require that regulations for a Medicinal Cannabis Scheme be set up within a year after the law comes into effect; permit the use of cannabis varieties already available in New Zealand to be used for medicinal products; and revising THC thresholds for CBD medicinal products.
The Bill was subsequently referred to the Committee of the whole House on 5 December 2018.
Third reading
On 11 December, the Misuse of Drugs (Medicinal Cannabis) Bill passed its third reading. The bill was supported by Labour, New Zealand First and the Greens (63) but opposed by National (53). NZ First health spokesperson Jenny Marcroft praised the inclusion of anyone in palliative care under the bill as a compassionate approach that would provide 25,000 people with a defence for using medicinal cannabis. Greens drug reform spokesperson Chloe Swarbrick said the bill would allow the development of a domestic market for regulated cannabis products. Health Minister and bill initiator David Clark stated that the bill would allow medicinal cannabis to be made available on prescription.
By contrast, National claim that the bill amounted to the decriminalisation of cannabis by stealth, "We support medicinal cannabis but strongly oppose the smoking of loose leaf cannabis in public. Smoked loose leaf is not a medicine" said spokesman Shane Reti.
Royal Assent
On 17 December, the act received royal assent and commenced the following day.
Referendum on recreational consumption of cannabis
Also on 18 December, the Government announced that a nationwide, binding referendum on recreational consumption of cannabis would be held as part of the 2020 general election.
References
External links
2018 in New Zealand law
Cannabis in New Zealand
Drug control law
Drug policy of New Zealand
Statutes of New Zealand | Misuse of Drugs (Medicinal Cannabis) Amendment Act 2018 | [
"Chemistry"
] | 1,506 | [
"Drug control law",
"Regulation of chemicals"
] |
59,522,476 | https://en.wikipedia.org/wiki/Richard%20Dronskowski | Richard Dronskowski (born 11 November 1961, in Brilon) is a German chemist and physicist. He is a full professor at the RWTH Aachen University.
Life
Dronskowski studied chemistry and physics at the University of Münster from 1981 to 1986. He completed his chemistry diploma with Bernt Krebs and Arndt Simon in 1987. He finished his physics diploma with Ole Krogh Andersen and Johannes Pollmann in 1989. He received his doctorate under supervision of Arndt Simon at the University of Stuttgart. From 1991 to 1992, he was a visiting scientist in the group of Roald Hoffmann at Cornell University. In 1995, he finished his habilitation at the University of Dortmund. Since 1997, he is a full professor at the RWTH Aachen University.
Research
His research focuses on the following topics:
solid-state chemistry
quantum chemistry
nitrides
carbodiimides
guanidinates
intermetallics
steel
phase-change materials
chemical bonding (e.g., Crystal Orbital Hamilton Populations)
ab initio thermochemistry
structural chemistry
neutron diffraction
Awards
1990 Otto Hahn Medal (Max Planck Society)
1996 Prize of Angewandte Chemie
1997 Chemistry Lecturer Prize (Fonds der chemischen Industrie)
2014 Distinguished Professorship (RWTH Aachen University)
2015 Innovation Award (RWTH Aachen University)
2017 Egon Wiberg Lecture (Ludwig Maximilian University of Munich)
Selected publications
References
External links
Living people
21st-century German chemists
21st-century German physicists
1961 births
Academic staff of RWTH Aachen University
Solid state chemists
University of Münster alumni
University of Stuttgart alumni
Academic staff of the Technical University of Dortmund | Richard Dronskowski | [
"Chemistry"
] | 339 | [
"Solid state chemists"
] |
59,522,751 | https://en.wikipedia.org/wiki/Bauer%20maximum%20principle | Bauer's maximum principle is the following theorem in mathematical optimization:
Any function that is convex and continuous, and defined on a set that is convex and compact, attains its maximum at some extreme point of that set.
It is attributed to the German mathematician Heinz Bauer.
Bauer's maximum principle immediately implies the analogue minimum principle:
Any function that is concave and continuous, and defined on a set that is convex and compact, attains its minimum at some extreme point of that set.
Since a linear function is simultaneously convex and concave, it satisfies both principles, i.e., it attains both its maximum and its minimum at extreme points.
Bauer's maximization principle has applications in various fields, for example, differential equations and economics.
References
Mathematical optimization
Mathematical theorems | Bauer maximum principle | [
"Mathematics"
] | 162 | [
"Mathematical analysis",
"Mathematical analysis stubs",
"nan",
"Mathematical problems",
"Mathematical theorems",
"Mathematical optimization"
] |
59,524,587 | https://en.wikipedia.org/wiki/Applied%20Spectral%20Imaging | Applied Spectral Imaging or ASI is a multinational biomedical company that develops and manufactures microscopy imaging and digital analysis tools for hospitals, service laboratories and research centers. The company provides cytogenetic, pathology, and research laboratories with bright-field, fluorescence and spectral imaging in clinical applications. Test slides can be scanned, captured, archived, reviewed on the screen, analyzed with computer-assisted algorithms, and reported. ASI system platforms automate the workflow process to reduce human error in the identification and classification of chromosomal disorders, genome instability, various oncological malignancies, among other diseases.
History
Founded in 1993, ASI initially focused on spectral imaging devices for the research community.
In 2002, ASI made a strategic move to expand into the clinical cytogenetics market and thereby, introduced its CytoLabView system for karyotyping and FISH imaging.
In 2005, ASI launched its automated scanning system in order to increase throughput for case analysis, compensating for higher sample volumes and helping laboratories to better cope with a deficit of laboratory technicians and other professions. As the demand increased for more diagnostics, ASI focused on providing faster imaging and analysis to improve turn-around-time for patient results. Scanning automation and algorithms enabled laboratory technologists to spend more time on results and analysis rather than manual labor.
In 2011, ASI launched a proprietary software platform named GenASIs. The software automates the diagnostic manual process. Physicians, medical scientists and laboratory technicians integrate digital technology to manage the visualization of the slide and compute the analysis. Through algorithms, tissue suspension cell and chromosomes are analyzed for aberrations, cell classification, tumor proportion score etc. ASI's high throughput tray loader, introduced the same year, was manufactured to automate the sample and scanning process.
In 2017, ASI introduced PathFusion and HiPath Pro- the company's full pathology imaging suite for H&E, IHC, and FISH visualization and analysis software including tissue matching and whole slide imaging.
FDA Clearances
ASI has a wide FDA cleared portfolio. Its products and Quality System (QS) are compliant with IVD medical Device Standards and Regulations.
2001: FDA cleared for BandView product
2005: FDA cleared for FISHView product
2007: FDA cleared for SpotScan application for CEP XY
2010: FDA cleared for SpotScan application for HER2/neu
2011: FDA cleared for SpotScan application for UroVysion
2013: FDA cleared for SpotsScan application for ALK
2015: FDA cleared for HiPath system for IHC family HER2, ER, PR and Ki67
Patents
ASI patents cover methods and instrumentation for general fields in the life sciences. Some of the claims are specific to a special type of hardware. Others have a more general scope and refer to the application rather than the instrument. Some of the original patents are related to spectral imaging systems based on interferometry and other spectral imaging instrumentation.
Functionalities
The functionalities that Applied Spectral Imaging provides laboratories and hospitals include automated slide scanning, applications interface, whole slide imaging, scoring and analysis, sharing capabilities for team review and final sign off, database management, secure archiving of reports, connectivity to the LIS and standardized testing.
Clinical applications
ASI's clinical applications for laboratories include the scoring of chromosome analysis and karyotyping, fluorescent karyotyping, spectral karyotyping, karyotyping of multiple species, scanning and detection of metaphases and interphases, FISH review and analysis, matching of tissue FISH with H&E/ IHC, Brightfield whole slide imaging, IHC quantitative scoring, Cytokinesis-blocked micronucleus, region of interest annotating and measuring, tissue matching and FISH imaging, analysis and documentation of membrane IHC stain, analysis and documentation of nuclear IHC stain, chromosome comparison modules, Whole Slide Image viewing, enhancement and documentation, data case management and network connectivity of multiple systems in a network.
Products
ASI HiPath Pro - Brightfield imaging analysis system for a variety of histopathology needs, including IHC scoring and Whole Slide Imaging of H&E and IHC samples.
ASI PathFusion - Bridges the gap between Brightfield pathology and FISH. Combines Whole Slide Imaging, computational Tissue FISH and digital tissue matching of FISH with Haemotoxylin and Eosin (H&E) or Immunohistochemistry (IHC) samples.
ASI HiBand - Digital chromosome analysis for counting, indexing and karyotyping.
ASI HiFISH - Computational FISH diagnostics for classification, scanning and imaging analysis.
ASI CytoPower - Complete chromosomes' analysis, Karyotyping and FISH cell classification platform.
ASI Rainbow - Analysis & multicolor imaging solution for Fluorescence and Brightfield samples
References
External links
Companies based in Carlsbad, California
Companies established in 1993
Bioinformatics companies
Multinational companies headquartered in the United States
Biotechnology companies established in 1993
Biomedical engineering
Biological engineering
Medical technology companies of the United States
Medical imaging | Applied Spectral Imaging | [
"Engineering",
"Biology"
] | 1,036 | [
"Biological engineering",
"Medical technology",
"Biomedical engineering"
] |
59,524,900 | https://en.wikipedia.org/wiki/Malcolm%20Macdonald%20%28engineer%29 | Malcolm Macdonald is a Scottish space technology engineer, academic, and director. He is a Professor and the Chair of Applied Space Technology at the University of Strathclyde, and a visiting professor at University College Dublin. He was Director of the Scottish Centre of Excellence in Satellite Applications, SoXSA, from 2014 - 2020, and a non-executive member of the UK Space Agency Steering Board from 2017 - 2020. He is an acknowledged expert in space research, and in 2021 was referred to in the media as "Scotland's leading space expert".
Education
Malcolm Macdonald studied at University of Glasgow, graduating with a first in Aerospace engineering in 2000. He completed his doctoral research in Astrodynamics at University of Glasgow from then until the end of 2002, graduating in 2005, where we studied with Colin R. McInnes.
Career and research
After completing his doctoral research Macdonald continued to work with Colin R. McInnes as his Research Assistant until the end of 2004. In 2005 Macdonald joined SCISYS where he worked on projects including LISA Pathfinder and ADM-Aeolus, prior to joining the University of Strathclyde in 2008.
Macdonald describes himself as "a professional space technology engineer, working in academia". His research is in space technology, including small satellites and solar sails, as well as astrodynamics, and network science. He was awarded the 2016 Royal Society of Edinburgh Sir Makdougall Brisbane Medal, for "outstanding research work in the development and application of space mission systems to challenge conventional ideas and advance new concepts in the exploration and exploitation of space." He was elected a fellow of the Royal Society of Edinburgh in 2021.
Macdonald was the only non-US member of a National Academies of Sciences, Engineering, and Medicine's committee on Achieving Science Goals with CubeSats, and a member of the Committee on Space Research (COSPAR) Study Group on Small Satellites for Space Sciences. He was also a member of International Academy of Astronautics study group 4.23 on Post-Mission Disposal for Micro and Smaller Satellites: Concepts and Trade Studies.
Macdonald has been an associate editor of the American Institute of Aeronautics and Astronautics (AIAA) Journal of Guidance, Control, and Dynamics since 2009, and led the development of The International Handbook of Space Technology, as well as contributing several chapters. This Handbook has sixty contributing authors, including high-profile contributors from Japan, Europe, and the US, including a foreword by Elon Musk.
Macdonald is also involved in the commercialisation of space through his role as the director of the Scottish Centre of Excellence in Satellite Applications, which supports the application of space data and services as well as the development of technology that enables this data and services. He also founded the Data.Space conference, which was held annually in Glasgow, and attracted c-suite speakers and thought leaders from across the world.
Outreach and media
Macdonald is frequently quoted by national and international media on topics relating to the space industry, and is a regular contributor to BBC Radio and Television, including BBC Radio Scotland shows such as Good Morning Scotland and Drive Time, as well as appearing on television shows such as the BBC Daily Politics Show and STV's Scotland Tonight.
Macdonald is also the co-creator & co-producer of a so-called science quiz show, New Peers Review, which is broadcast on Deutsche Welle's Spectrum radio show.
He also regularly delivers talks to branches of learned societies, such as the Royal Aeronautical Society and the Institute of Physics, as well as to local science, engineering, and astronomy clubs. He has also worked with the BBC to broaden understanding of issues related to space, such as the re-entry of Tiangong-1, with CBeebies programme Nina and the Neurons for the episode Earth Explorers, and with BBC Radio Scotland to put a Red Nose into near-space for Comic Relief in 2013.
Awards and honours
Recognition of his engineering achievements includes:
2023 Fellowship of the Royal Academy of Engineering (FREng)
2021 Fellowship of the Royal Society of Arts (FRSA)
2021 Knowledge Exchange Champion of the Year, Scottish Knowledge Exchange Awards
2021 Fellowship of the Royal Society of Edinburgh (FRSE)
2016 Royal Society of Edinburgh Sir Makdougall Brisbane Medal
2013 Fellowship of the Royal Aeronautical Society (FRAeS)
2013 Elected member Royal Society of Edinburgh Young Academy of Scotland, five-year term.
2012 Best Scottish Knowledge Transfer Partnership Award, with Clyde Space Ltd.
2011 Sir Arthur C. Clarke Award for Space Research Achievement, awarded to the Advanced Space Concepts Laboratory
2010 Times Higher Education, THE, Outstanding Engineering Research Team of the Year shortlist nomination.
2009 Associate Fellow of the American Institute of Aeronautics and Astronautics
2008 Registered European Engineer with the European Federation of National Engineering Associations.
2008 Engineering Council UK Chartered Engineer (UK). Registration No. 571998.
2003 Ackroyd Stuart Propulsion Prize (2003) awarded by the Royal Aeronautical Society
References
Bibliography
The International Handbook of Space Technology Editors: Macdonald, Malcolm, Badescu, Viorel (Eds.), Springer-Verlag Berlin Heidelberg, 2014, ,
Advances in Solar Sailing Editor: Macdonald, Malcolm (Eds.), Springer-Verlag Berlin Heidelberg, 2014, ,
Macdonald, Malcolm, Smith, Lesley Jane, Impact Assessment of Scottish Independence on the Space Sector, University of Strathclyde publishing, 2014, University of Strathclyde publishing - Impact Assessment of Scottish Independence on the Space Sector
External links
Staff Profile - Prof Malcolm Macdonald, University of Strathclyde
Aerospace engineers
Space systems engineers
Academics of the University of Strathclyde
Fellows of the Royal Aeronautical Society
Fellows of the Royal Society of Edinburgh
Fellows of the Royal Academy of Engineering
Fellows of the Royal Society of Arts
Alumni of the University of Glasgow
Engineers from Glasgow
Scottish aerospace engineers
1978 births
Living people
20th-century Scottish engineers
21st-century Scottish engineers | Malcolm Macdonald (engineer) | [
"Engineering"
] | 1,179 | [
"Aerospace engineers",
"Aerospace engineering"
] |
59,525,996 | https://en.wikipedia.org/wiki/4%2C4%E2%80%B2-%28Hexafluoroisopropylidene%29diphthalic%20anhydride | 4,4′-(Hexafluoroisopropylidene)diphthalic anhydride (6FDA) is an aromatic organofluorine compound and the dianhydride of 4,4′-(hexafluoroisopropylidene)bisphthalic acid (name derived from phthalic acid).
Synthesis
The raw materials for 6FDA are hexafluoroacetone and orthoxylene. With hydrogen fluoride as a catalyst, the compounds react to 4,4′-(hexafluoroisopropylidene)bis(o-xylene). This is oxidized with potassium permanganate to 4,4′-(hexafluoroisopropylidene)bisphthalic acid. Dehydration gives the dianhydride 6FDA.
Applications
6FDA is used as monomer for the synthesis of fluorinated polyimides. These are prepared by the polymerisation of 6FDA with an aromatic diamine such as 3,5-diaminobenzoic acid or 4,4'-diaminodiphenyl sulfide. Such fluorinated polyimides are used in special applications, e. g. used to make gas-permeable polymer membranes, in the field of microelectronics and optics, such as optical lenses from polymers, OLEDs, or high-performance CMOS-contact image sensors (CISs).
These polyimides are typically soluble in common organic solvents, facilitating their production and processing. They have very low water absorption, which makes them particularly suitable for special optical applications.
References
Monomers
Carboxylic anhydrides
Trifluoromethyl compounds | 4,4′-(Hexafluoroisopropylidene)diphthalic anhydride | [
"Chemistry",
"Materials_science"
] | 373 | [
"Monomers",
"Polymer chemistry"
] |
59,527,455 | https://en.wikipedia.org/wiki/C11H13NO4 | {{DISPLAYTITLE:C11H13NO4}}
The molecular formula C11H13NO4 (molar mass: 223.23 g/mol, exact mass: 223.0845 u) may refer to:
N-Acetyl-L-tyrosine
Bendiocarb
Diethyl lutidinate
Mephenoxalone
Molecular formulas | C11H13NO4 | [
"Physics",
"Chemistry"
] | 79 | [
"Molecules",
"Set index articles on molecular formulas",
"Isomerism",
"Molecular formulas",
"Matter"
] |
59,527,925 | https://en.wikipedia.org/wiki/Ross%20640 | Ross 640 is a white dwarf star in the northern constellation of Hercules, positioned near the constellation border with Corona Borealis. With an apparent visual magnitude of 13.83, it is too faint to be visible to the naked eye. Its trigonometric parallax from the Gaia mission is , corresponding to a distance of .
This compact star has a stellar classification of DZA5.5, indicating a metal-rich atmosphere accompanied by weaker lines of hydrogen. A detailed analysis of its spectrum revealed that Ross 640 is a relatively cool white dwarf with an effective temperature of approximately 8,100 K, which means that it has been in the white dwarf phase for slightly more than 1 billion years. Ross 640 has a spectrum characterized by hydrogen Balmer lines in the visible and very strong ionized magnesium lines in the ultraviolet. The presence of heavy elements in the photosphere of Ross 640 indicates that it recently accreted rocky debris from its planetary system.
References
White dwarfs
Hercules (constellation)
Ross objects
Gliese and GJ objects | Ross 640 | [
"Astronomy"
] | 209 | [
"Hercules (constellation)",
"Constellations"
] |
59,529,853 | https://en.wikipedia.org/wiki/Triphosphono%20phosphate | Triphosphono phosphate is the simplest branched polyphosphoric acid. It is a hexaprotic acid.
It is used to prepare phosphoric monoesters.
References
Phosphates | Triphosphono phosphate | [
"Chemistry"
] | 43 | [
"Phosphates",
"Salts"
] |
59,530,258 | https://en.wikipedia.org/wiki/Gestonorone%20acetate | Gestonorone acetate, or gestronol acetate, also known as norhydroxyprogesterone acetate, is a progestin of the 19-norprogesterone and 17α-hydroxyprogesterone groups which was developed in the early 1960s but was never marketed. It is the C17α acetate ester of gestronol (17α-hydroxy-19-norprogesterone).
Gestonorone acetate has been found to consistently inhibit ovulation at an oral dosage of 10 mg/day in combination with 50 μg/day oral ethinylestradiol. Weak or no endometrial effects were observed at an oral dosage of 100 mg/day, basal vacuoles appeared at 130 to 140 mg/day, and full endometrial secretory transformation occurred at 220 mg/day.
See also
Gestonorone caproate
References
Abandoned drugs
Acetate esters
Diketones
Norpregnanes
Progestogen esters
Progestogens | Gestonorone acetate | [
"Chemistry"
] | 223 | [
"Drug safety",
"Abandoned drugs"
] |
59,530,924 | https://en.wikipedia.org/wiki/S-object | In algebraic topology, an -object (also called a symmetric sequence) is a sequence of objects such that each comes with an action of the symmetric group .
The category of combinatorial species is equivalent to the category of finite -sets (roughly because the permutation category is equivalent to the category of finite sets and bijections.)
S-module
By -module, we mean an -object in the category of finite-dimensional vector spaces over a field k of characteristic zero (the symmetric groups act from the right by convention). Then each -module determines a Schur functor on .
This definition of -module shares its name with the considerably better-known model for highly structured ring spectra due to Elmendorf, Kriz, Mandell and May.
See also
Highly structured ring spectrum
Notes
References
Algebraic topology | S-object | [
"Mathematics"
] | 167 | [
"Topology stubs",
"Fields of abstract algebra",
"Topology",
"Algebraic topology"
] |
54,556,438 | https://en.wikipedia.org/wiki/Komar%20superpotential | In general relativity, the Komar superpotential, corresponding to the invariance of the Hilbert–Einstein Lagrangian , is the tensor density:
associated with a vector field , and where denotes covariant derivative with respect to the Levi-Civita connection.
The Komar two-form:
where denotes interior product, generalizes to an arbitrary vector field the so-called above Komar superpotential, which was originally derived for timelike Killing vector fields.
Komar superpotential is affected by the anomalous factor problem: In fact, when computed, for example, on the Kerr–Newman solution, produces the correct angular momentum, but just one-half of the expected mass.
See also
Superpotential
Einstein–Hilbert action
Komar mass
Tensor calculus
Christoffel symbols
Riemann curvature tensor
Notes
References
Equations of physics
Tensors
General relativity
Potentials | Komar superpotential | [
"Physics",
"Mathematics",
"Engineering"
] | 179 | [
"Tensors",
"Equations of physics",
"Mathematical objects",
"Equations",
"General relativity",
"Relativity stubs",
"Theory of relativity"
] |
54,558,157 | https://en.wikipedia.org/wiki/List%20of%20steroid%20esters | List of steroid esters may refer to:
List of androgen esters – androgen esters
List of estrogen esters – estrogen esters
List of progestogen esters – progestogen esters
List of corticosteroid esters – corticosteroid esters
See also
List of steroids
List of sex-hormonal medications available in the United States
List of combined sex-hormonal preparations
References
Steroid esters
Chemistry-related lists
Lists of lists | List of steroid esters | [
"Chemistry"
] | 106 | [
"nan"
] |
54,558,894 | https://en.wikipedia.org/wiki/Sixth%20power | In arithmetic and algebra the sixth power of a number n is the result of multiplying six instances of n together. So:
.
Sixth powers can be formed by multiplying a number by its fifth power, multiplying the square of a number by its fourth power, by cubing a square, or by squaring a cube.
The sequence of sixth powers of integers are:
0, 1, 64, 729, 4096, 15625, 46656, 117649, 262144, 531441, 1000000, 1771561, 2985984, 4826809, 7529536, 11390625, 16777216, 24137569, 34012224, 47045881, 64000000, 85766121, 113379904, 148035889, 191102976, 244140625, 308915776, 387420489, 481890304, ...
They include the significant decimal numbers 106 (a million), 1006 (a short-scale trillion and long-scale billion), 10006 (a quintillion and a long-scale trillion) and so on.
Squares and cubes
The sixth powers of integers can be characterized as the numbers that are simultaneously squares and cubes.
In this way, they are analogous to two other classes of figurate numbers: the square triangular numbers, which are simultaneously square and triangular,
and the solutions to the cannonball problem, which are simultaneously square and square-pyramidal.
Because of their connection to squares and cubes, sixth powers play an important role in the study of the Mordell curves, which are elliptic curves of the form
When is divisible by a sixth power, this equation can be reduced by dividing by that power to give a simpler equation of the same form.
A well-known result in number theory, proven by Rudolf Fueter and Louis J. Mordell, states that, when is an integer that is not divisible by a sixth power (other than the exceptional cases and ), this equation either has no rational solutions with both and nonzero or infinitely many of them.
In the archaic notation of Robert Recorde, the sixth power of a number was called the "zenzicube", meaning the square of a cube. Similarly, the notation for sixth powers used in 12th century Indian mathematics by Bhāskara II also called them either the square of a cube or the cube of a square.
Sums
There are numerous known examples of sixth powers that can be expressed as the sum of seven other sixth powers, but no examples are yet known of a sixth power expressible as the sum of just six sixth powers. This makes it unique among the powers with exponent k = 1, 2, ... , 8, the others of which can each be expressed as the sum of k other k-th powers, and some of which (in violation of Euler's sum of powers conjecture) can be expressed as a sum of even fewer k-th powers.
In connection with Waring's problem, every sufficiently large integer can be represented as a sum of at most 24 sixth powers of integers.
There are infinitely many different nontrivial solutions to the Diophantine equation
It has not been proven whether the equation
has a nontrivial solution, but the Lander, Parkin, and Selfridge conjecture would imply that it does not.
Other properties
is divisible by 7 if n isn't divisible by 7.
See also
Sextic equation
Eighth power
Seventh power
Fifth power (algebra)
Fourth power
Cube (algebra)
Square (algebra)
References
External links
Integers
Number theory
Elementary arithmetic
Integer sequences
Unary operations
Figurate numbers | Sixth power | [
"Mathematics"
] | 786 | [
"Sequences and series",
"Figurate numbers",
"Functions and mappings",
"Integer sequences",
"Mathematical structures",
"Unary operations",
"Discrete mathematics",
"Elementary arithmetic",
"Recreational mathematics",
"Mathematical objects",
"Combinatorics",
"Elementary mathematics",
"Arithmeti... |
54,558,969 | https://en.wikipedia.org/wiki/Seventh%20power | In arithmetic and algebra, the seventh power of a number n is the result of multiplying seven instances of n together. So:
.
Seventh powers are also formed by multiplying a number by its sixth power, the square of a number by its fifth power, or the cube of a number by its fourth power.
The sequence of seventh powers of integers is:
0, 1, 128, 2187, 16384, 78125, 279936, 823543, 2097152, 4782969, 10000000, 19487171, 35831808, 62748517, 105413504, 170859375, 268435456, 410338673, 612220032, 893871739, 1280000000, 1801088541, 2494357888, 3404825447, 4586471424, 6103515625, 8031810176, ...
In the archaic notation of Robert Recorde, the seventh power of a number was called the "second sursolid".
Properties
Leonard Eugene Dickson studied generalizations of Waring's problem for seventh powers, showing that every non-negative integer can be represented as a sum of at most 258 non-negative seventh powers (17 is 1, and 27 is 128). All but finitely many positive integers can be expressed more simply as the sum of at most 46 seventh powers. If powers of negative integers are allowed, only 12 powers are required.
The smallest number that can be represented in two different ways as a sum of four positive seventh powers is 2056364173794800.
The smallest seventh power that can be represented as a sum of eight distinct seventh powers is:
The two known examples of a seventh power expressible as the sum of seven seventh powers are
(M. Dodrill, 1999);
and
(Maurice Blondot, 11/14/2000);
any example with fewer terms in the sum would be a counterexample to Euler's sum of powers conjecture, which is currently only known to be false for the powers 4 and 5.
See also
Eighth power
Sixth power
Fifth power (algebra)
Fourth power
Cube (algebra)
Square (algebra)
References
Integers
Number theory
Elementary arithmetic
Integer sequences
Unary operations
Figurate numbers | Seventh power | [
"Mathematics"
] | 487 | [
"Sequences and series",
"Algebra stubs",
"Integer sequences",
"Mathematical structures",
"Mathematical objects",
"Combinatorics",
"Elementary mathematics",
"Numbers",
"Number theory",
"Figurate numbers",
"Integers",
"Algebra",
"Functions and mappings",
"Arithmetic",
"Discrete mathematics... |
54,560,666 | https://en.wikipedia.org/wiki/OT1%20encoding | OT1 (aka TeX text) is a 7-bit TeX encoding developed by Donald E. Knuth.
Character set
See also
OML encoding
OMS encoding
References
Character sets
TeX | OT1 encoding | [
"Mathematics"
] | 38 | [
"TeX",
"Mathematical markup languages"
] |
54,560,830 | https://en.wikipedia.org/wiki/International%20System%20for%20Human%20Cytogenomic%20Nomenclature | The International System for Human Cytogenomic Nomenclature (ISCN; previously the International System for Human Cytogenetic Nomenclature) is an international standard for human chromosome nomenclature, which includes band names, symbols, and abbreviated terms used in the description of human chromosome and chromosome abnormalities.
The ISCN has been used as the central reference among cytogeneticists since 1960.
Abbreviations of this system include a minus sign (-) for chromosome deletions, and del for deletions of parts of a chromosome.
Revision history
ISCN (2024). S. Karger Publishing.
ISCN (2020). S. Karger Publishing.
ISCN (2016). S. Karger Publishing.
ISCN (2013). S. Karger Publishing.
ISCN (2009). S. Karger Publishing.
ISCN (2005). S. Karger Publishing.
ISCN (1995). S. Karger Publishing.
ISCN (1991). S. Karger Publishing.
ISCN (1985). S. Karger Publishing.
ISCN (1981). S. Karger Publishing.
ISCN (1978). S. Karger Publishing.
Paris Conference (1971): "Standardization in Human Cytogenetics." (PDF) Birth Defects: Original Article Series, Vol 8, No 7 (The National Foundation, New York 1972)
Chicago Conference (1966): "Standardization in Human Cytogenetics." Birth Defects: Original Article Series, Vol 2, No 2 (The National Foundation, New York 1966).
London Conference (1963): "London Conference on the Normal Human Karyotype." Cytogenetics 2:264–268 (1963)
Denver Conference (1960): "A proposed standard system of nomenclature of human mitotic chromosomes." The Lancet 275.7133 (1960): 1063-1065.
See also
Locus (genetics)
Cytogenetic notation
References
External links
About the ISCN recommendations - Human Genome Variation Society
Cytogenetics
Biological nomenclature | International System for Human Cytogenomic Nomenclature | [
"Biology"
] | 435 | [
"Biological nomenclature"
] |
54,561,103 | https://en.wikipedia.org/wiki/LY1%20encoding | LY1 (Y&Y 256 glyph encoding) is an 8-bit TeX encoding developed by Berthold Horn.
Character set
References
Character sets
TeX | LY1 encoding | [
"Mathematics"
] | 34 | [
"TeX",
"Mathematical markup languages"
] |
54,561,126 | https://en.wikipedia.org/wiki/Basic%20lead%20phosphite | Basic lead phosphite is an inorganic compound with the proposed composition Pb3O(OH)2(HPO3). The compound contains the phosphite anion, which provides the reducing properties associated with the application of this material.
It is widely used as a stabilizer for chlorine-containing polymers, especially polyvinylchloride. Other lead phosphites are known, including normal lead phosphite, PbHPO3, although the basic salt is especially effective.
References
Phosphites
Inorganic phosphorus compounds
Lead(II) compounds | Basic lead phosphite | [
"Chemistry"
] | 121 | [
"Inorganic phosphorus compounds",
"Inorganic compounds",
"Inorganic compound stubs"
] |
54,561,208 | https://en.wikipedia.org/wiki/Chip-firing%20game | The chip-firing game is a one-player game on a graph which was invented around 1983 and since has become an important part of the study of structural combinatorics.
Each vertex has the number of "chips" indicated by its state variable. On each firing, a vertex is selected and one of its chips is transferred to each neighbour (vertex it shares an edge with). The number of chips on each vertex cannot be negative. The game ends when no firing is possible.
Definition
Let the finite graph G be connected and loopless, with vertices V = {1, 2, . . . , n}. Let deg(v) be the degree of a vertex, and e(v,w) the number of edges between vertices v and w. A configuration or state of the game is defined by assigning each vertex a nonnegative integer s(v), representing the number of chips on this vertex. A move starts with selecting a vertex w which has at least as many chips as its degree: s(w) ≥ deg(w). The vertex w is fired, moving one chip from w along each incident edge to a neighbouring vertex, producing a new configuration defined by:and for v ≠ w, A state in which no further firing is possible is a stable state. Starting from an initial configuration, the game proceeds with the following results (on a connected graph).
If the number of chips is less than the number of edges, the game is always finite, reaching a stable state.
If each vertex has fewer chips than its degree, the game is finite.
If the number of chips is at least the number of edges, the game can be infinite, never reaching a stable state, for an appropriately chosen initial configuration.
If the number of chips is more than twice the number of edges minus the number of vertices, the game is always infinite.
For finite chip-firing games, the possible orders of firing events can be described by an antimatroid. It follows from the general properties of antimatroids that the number of times each vertex fires, and the eventual stable state, do not depend on the order of firing events.
Dollar games
Some chip-firing games, known as dollar games, interpret the chips as dollars and the vertices as money borrowers and lenders. Two variants of dollar game are prominent in the literature:
Baker and Norine's variant
In this dollar game, negative integer values (representing debt) are assigned to some of the vertices of the finite graph G. A game is called winnable if there exists a state where all the vertices can be made positive. A a graph-theoretic analogue of Riemann–Roch theorem can be used to characterize if a game is winnable or not.
Biggs's Variant
In a variant form of chip-firing closely related to the sandpile model, also known as the dollar game, a single special vertex q is designated as the bank, and is allowed to go into debt, taking a negative integer value s(q) < 0. If any other vertex can fire, the bank cannot fire, only collecting chips. Eventually, q will accumulate so many chips that no other vertex can fire: only in such a state, vertex q can fire chips to neighbouring vertices to "jump start the economy".
The set of states which are stable (i.e. for which only q can fire) and recurrent for this game can be given the structure of an abelian group which is isomorphic to the direct product of and the sandpile group (also referred to as Jacobian group or critical group). The order of the latter is the tree number of the graph.
See also
Abelian sandpile model
The Mathematics of Chip-Firing
Riemann–Roch theorem
References
A. Björner, L. Lovász: Chip-Firing Games on Directed Graphs. Journal of Algebraic Combinatorics, December 1992, Volume 1, Issue 4, pp 305–328
External links
MIT Course 18.312: Algebraic Combinatorics
Weisz Ágoston: A koronglövő játék. Szakdolgozat, ELTE TTK Bsc, 2014
Chip firing survey on Egerváry Research Group
Games built on chip-firing (2010)
The Dollar Game - Numberphile video about Baker and Norine's dollar game variant.
https://thedollargame.io/ - A game based on the Baker and Norine's dollar game variant.
Combinatorics
Graph theory | Chip-firing game | [
"Mathematics"
] | 916 | [
"Discrete mathematics",
"Mathematical relations",
"Graph theory",
"Combinatorics"
] |
54,562,671 | https://en.wikipedia.org/wiki/Dottie%20number | In mathematics, the Dottie number is a constant that is the unique real root of the equation
,
where the argument of is in radians.
The decimal expansion of the Dottie number is given by:
= ... .
Since is decreasing and its derivative is non-zero at , it only crosses zero at one point. This implies that the equation has only one real solution. It is the single real-valued fixed point of the cosine function and is a nontrivial example of a universal attracting fixed point. It is also a transcendental number because of the Lindemann–Weierstrass theorem. The generalised case for a complex variable has infinitely many roots, but unlike the Dottie number, they are not attracting fixed points.
The name of the constant originates from a professor of French named Dottie who observed the number by repeatedly pressing the cosine button on her calculator.
The Dottie number, for which an exact series expansion can be obtained using the Faà di Bruno formula, has interesting connections with the Kepler and Bertrand's circle problems.
Identities
The Dottie number appears in the closed form expression of some integrals:
Using the Taylor series of the inverse of at (or equivalently, the Lagrange inversion theorem), the Dottie number can be expressed as the infinite series:
where each is a rational number defined for odd n as
The Dottie number can also be expressed as:
where is the inverse of the regularized beta function. This value can be obtained using Kepler's equation, along with other equivalent closed forms.
In Microsoft Excel and LibreOffice Calc spreadsheets, the Dottie number can be expressed in closed form as . In the Mathematica computer algebra system, the Dottie number is .
Another closed form representation:
where is the inverse survival function of Student's t-distribution. In Microsoft Excel and LibreOffice Calc, due to the specifics of the realization of `TINV` function, this can be expressed as formulas and .
Notes
References
External links
Mathematical constants
Real transcendental numbers
Fixed points (mathematics) | Dottie number | [
"Mathematics"
] | 432 | [
"Mathematical analysis",
"Fixed points (mathematics)",
"Mathematical objects",
"Topology",
"nan",
"Mathematical constants",
"Numbers",
"Dynamical systems"
] |
54,562,796 | https://en.wikipedia.org/wiki/Simple%20wave | A simple wave is a flow in a region adjacent to a region of constant state. In the language of Riemann invariant, the simple wave can also be defined as the zone where all but one of the Riemann invariants are constant in the region of interest, and consequently, a simple wave zone is covered by arcs of characteristics that are straight lines.
Simple waves occur quite often in nature. There is a theorem (see Courant and Friedrichs) that states that a non-constant state of flow adjacent to a constant value is always a simple wave. All expansion fans including Prandtl–Meyer expansion fan are simple waves. Compressive waves until shock wave forms are also simple waves. Weak shocks (including sound waves) are also simple waves up to second-order approximation in the shock strength.
Simple waves are also defined by the behavior that all the characteristics under hodograph transformation collapses into a single curve. This means that the Jacobian involved in the hodographic transformation is zero.
Unsteady one-dimensional simple waves
Let be the gas density, the velocity, the pressure and the speed of sound. In isentropic flows, entropy is constant and if the initial state of the gas is homogenous, then entropy is a constant everywhere at all times and therefore the pressure is a function only of , i.e., In simple waves, all dependent variables are just function of any one of the dependent variables (this is certainly the case in one-dimensional sound waves) and therefore we can assume the velocity to be also a function only of . i.e., This latter property is the cause of origin of the name simple wave, although the wave is nonlinear.
From the one-dimensional Euler equations, we have
which, because , can be written as
Further, since (remember that the time derivative of a function integrated along a curve is given by )
the two equations lead to
However, since determines and therefore the above derivatives must be equal so that . Thus, we obtain , whence
This equation provides the required relation or, or, etc. The above equation is just a statement that either the or the Riemann invariant is constant.
Thus, we obtain
,
which upon integration becomes
where is an arbitrary function. This equation indicates that the characteristics in the - plane are just straight lines. When and when consequently length scale and time scale associated with the initial function disappears, the problem is self-similar and the solution depends only on the ratio . This particular case is referred as the centred simple wave.
Steady two-dimensional simple waves
Similar to the unsteady one-dimensional waves, simple waves in steady two-dimensional system cab be derived. In this case, the solution is given by
where and is an arbitrary function of pressure. The characteristics in the - plane are straight lines. Similarly, the case corresponding to is referred as the centred simple wave; the Prandtl–Meyer expansion fan is a special case of this centred wave.
References
Flow regimes
Fluid dynamics | Simple wave | [
"Chemistry",
"Engineering"
] | 606 | [
"Piping",
"Chemical engineering",
"Flow regimes",
"Fluid dynamics"
] |
54,564,340 | https://en.wikipedia.org/wiki/Fred%20McBagonluri | Fred McBagonluri (born 18 August 1970) is a Ghanaian engineer, inventor, novelist, educator and thought leader, who is currently Provost and President at Academic City College. He was previously the founding Dean at the Faculty of Engineering at Ashesi University College. He was also the founding executive director of the Ghana Climate Innovation Center, a new cleantech incubator backed by the World Bank. Prior to his role at Ashesi University College, Prof. McBagonluri lived and worked in the United States. He was the Vice President of the New Product Development Joerns Healthcare in Arlington, Texas. He has held various roles in engineering, strategy, marketing, and research, and has worked with numerous Institutions in the US, including Princeton University, where he was a visiting research associate, working for Prof. Wole Soboyejo (distinguished Dean of Engineering, Worcester Polytechnic Institute, MA), Siemens Healthcare, and Becton and Dickinson and Co.
He holds a Bachelor of Science degree (Summa Cum Laude) in Manufacturing Engineering from Central State University, with a minor in Applied Math, a Master of Science in Engineering Science and Mechanics from Virginia Tech and a Doctorate in Materials Engineering from the University of Dayton. He also holds a Masters of business administration degree from the Massachusetts Institute of Technology (MIT).
McBagonluri was the Black Engineer of the year's most promising scientist in 2008 and was the 2009 finalist of the NASA Astronaut Candidate Corps (ASCAN). In 2008, he won the New Jersey State Healthcare Business (NJBiz) Innovator Hero Award. He made incredible contributions to the development of Computer Aided Process Architecture and automation.
As a former director of R&D, McBagonluri made contributions in the areas of computer-aided design, artificial intelligence, 3D data processing and advanced hearing systems. McBagonluri has over forty patents and patents application in his name. He has authored nine books including three novels. He is a member of the American Society of Mechanical Engineers, Society of Manufacturing Engineers, and an MIT Alfred P. Sloan Fellow.
Early life and education
Fred McBagonluri was born on 18 August 1970, at La Bawaleshie, East Legon in Ghana. He was the second of three sons born to David Mac-Bagonluri and Patience Mensah, and raised by his grandmother who never had any formal education. McBagonluri began his primary school at the University Staff Village, near University Hospital, Legon. He later attended St. Louis Preparatory near Wa. He proceeded to Nandom Senior High School (formerly Nandom Secondary school) where he obtained distinction at the Ordinary Level Certificate Examination (O level). He later went to St. Augustine's College in the Central region of Ghana for his advanced level education but shortly proceeded to Central State University, where he graduated with a Bachelor of Science (summa cum laude) in Manufacturing Engineering. He obtained Masters in Engineering Mechanics from Virginia Tech. He holds an MBA from the Massachusetts Institute of Technology, and a Ph.D. from the University of Dayton, where he studied Material Engineering. He has also successfully completed the Advanced Management Course and Mentoring Programs at Siemens and Advanced Leadership Development Program from BD University.
Work
McBagonluri is currently the President and Provost at Academic City College. Prior to his current role, McBagonluri lived and worked in the United States of America. He was the Vice President of the New Product Development at Joerns Healthcare in Arlington, Texas. He was the Worldwide Director of R&D/Hypodermic Injection Systems ($700–800M) and subsequently Director of Market Development at Becton Dickinson and Co (BD Medical), a Fortune 500 Company located in Franklin Lakes, NJ. McBagonluri has held various roles in Engineering, Strategy, Marketing, and Research, and has worked with numerous Institutions in the US, including Princeton University and Siemens HealthCare.
McBagonluri is not only a Scientist but a writer, a poet, and a novelist. He has many poems and has written about nine books including more than three novels. His most recent books have been: "Harvest of Jenes", "Ultimate Surrender", "When Tears Stand Still", "A women to Marry", and "Dusk Recitals". He also writes in technical journals, conference proceedings, and book chapters.
Achievements
McBagonluri won 2008 Black Engineering of the year's Most promising scientist. He was a finalist of the 2009 NASA astronauts Candidate Corps, a feat which nearly saw him land into space as the first African. He won the New Jersey State Healthcare Business (NJBiz) Innovator Hero Award in 2008. His incredible contributions to the development of Computer Aided Process Architecture and automation as the former director of R&D made an impact on the company's over 40 U.S./European/World patents and patent applications in the areas of Computer aided design, artificial intelligence, 3D processing and advanced hearing systems.
He is Co-Inventor on 22 issued US Patents. His massive contribution to engineering was recognized throughout the United States of America. McBagonluri has over forty patents and patents application in his name. He is a member of the American Society of Mechanical Engineers, Society of Manufacturing Engineers, and an MIT Alfred P. Sloan Fellow.
References
1970 births
21st-century Ghanaian engineers
American Society of Mechanical Engineers
SME (society)
Ghanaian educators
MIT Sloan School of Management alumni
Virginia Tech alumni
Central State University alumni
Living people
Ghanaian male writers
Ghanaian expatriates in the United States
University of Dayton alumni
Engineers from Ohio
St. Augustine's College (Cape Coast) alumni
Academic staff of Ashesi University | Fred McBagonluri | [
"Engineering"
] | 1,166 | [
"American Society of Mechanical Engineers",
"Mechanical engineering organizations"
] |
54,564,418 | https://en.wikipedia.org/wiki/Chandrasekhar%27s%20H-function | In atmospheric radiation, Chandrasekhar's H-function appears as the solutions of problems involving scattering, introduced by the Indian American astrophysicist Subrahmanyan Chandrasekhar. The Chandrasekhar's H-function defined in the interval , satisfies the following nonlinear integral equation
where the characteristic function is an even polynomial in satisfying the following condition
.
If the equality is satisfied in the above condition, it is called conservative case, otherwise non-conservative. Albedo is given by . An alternate form which would be more useful in calculating the H function numerically by iteration was derived by Chandrasekhar as,
.
In conservative case, the above equation reduces to
.
Approximation
The H function can be approximated up to an order as
where are the zeros of Legendre polynomials and are the positive, non vanishing roots of the associated characteristic equation
where are the quadrature weights given by
Explicit solution in the complex plane
In complex variable the H equation is
then for , a unique solution is given by
where the imaginary part of the function can vanish if is real i.e., . Then we have
The above solution is unique and bounded in the interval for conservative cases. In non-conservative cases, if the equation admits the roots , then there is a further solution given by
Properties
. For conservative case, this reduces to .
. For conservative case, this reduces to .
If the characteristic function is , where are two constants(have to satisfy ) and if is the nth moment of the H function, then we have
and
See also
Chandrasekhar's X- and Y-function
External links
MATLAB function to calculate the H function https://www.mathworks.com/matlabcentral/fileexchange/29333-chandrasekhar-s-h-function
References
Special functions
Integral equations
Scattering
Scattering, absorption and radiative transfer (optics) | Chandrasekhar's H-function | [
"Physics",
"Chemistry",
"Materials_science",
"Mathematics"
] | 385 | [
" absorption and radiative transfer (optics)",
"Special functions",
"Integral equations",
"Mathematical objects",
"Equations",
"Combinatorics",
"Scattering",
"Condensed matter physics",
"Particle physics",
"Nuclear physics"
] |
54,564,467 | https://en.wikipedia.org/wiki/Acroleinide | In organic chemistry, acroleinide is a functional group which is composed of a cyclic ketal of a diol with acrolein. In pharmaceutical chemistry, it is present in acrocinonide (triamcinolone acroleinide).
See also
Acetonide
Acetophenide
Aminobenzal
Cyclopentanonide
Pentanonide
References | Acroleinide | [
"Chemistry"
] | 78 | [
"Organic chemistry stubs"
] |
54,564,517 | https://en.wikipedia.org/wiki/Pentanonide | In organic chemistry, pentanonide is a functional group which is composed of a cyclic ketal of a diol with 3-pentanone. It is seen in amcinafal (triamcinolone pentanonide).
See also
Acetonide
Acetophenide
Acroleinide
Aminobenzal
Cyclopentanonide
References | Pentanonide | [
"Chemistry"
] | 75 | [
"Organic chemistry stubs"
] |
54,564,531 | https://en.wikipedia.org/wiki/Cyclopentanonide | In organic chemistry, cyclopentanonide is a functional group which is composed of a cyclic ketal of a diol with cyclopentanone. It is seen in amcinonide (triamcinolone acetate cyclopentanonide).
See also
Acetonide
Acetophenide
Acroleinide
Aminobenzal
Pentanonide
References
Cyclopentanonides | Cyclopentanonide | [
"Chemistry"
] | 85 | [
"Organic chemistry stubs"
] |
54,564,550 | https://en.wikipedia.org/wiki/Aminobenzal | In organic chemistry, aminobenzal is a functional group which is composed of a cyclic ketal of a diol with 4-dimethylaminobenzylidene. It is seen in triamcinolone aminobenzal benzamidoisobutyrate.
See also
Acetonide
Acetophenide
Acroleinide
Cyclopentanonide
Pentanonide
References | Aminobenzal | [
"Chemistry"
] | 80 | [
"Organic chemistry stubs"
] |
54,564,975 | https://en.wikipedia.org/wiki/G18P | G18P or RVA/pigeon-wt/AUS/VIC/2016/G18P[17] is a strain of Rotavirus A infecting and killing domestic pigeons. This disease is found in Western Australia, Victoria, and South Australia.
References
Rotaviruses
Infraspecific virus taxa | G18P | [
"Biology"
] | 68 | [
"Virus stubs",
"Viruses"
] |
54,566,234 | https://en.wikipedia.org/wiki/NGC%207072 | NGC 7072 is an intermediate spiral galaxy located about 210 million light-years away in the constellation of Grus. NGC 7072 was discovered by astronomer John Herschel on September 5, 1834.
NGC 7072 is a member of the NGC 7060 group, a group of galaxies which contains six members, including NGC 7057, NGC 7060, NGC 7072, NGC 7072A, ESO 287-16, and ESO 287-26. However, according to A.M. Garcia, the galaxy is in the IC 5105 group (also known as LGG 445), which contains 19 members, including NGC 7057, NGC 7087, NGC 7060, NGC 7072, NGC 7075, NGC 7110, NGC 7130, plus four galaxies from the Index Catalogue and eight galaxies from the ESO catalog.
One supernova has been observed in NGC 7072: SN2024yok (typeIIb, mag. 18.35).
See also
List of NGC objects (7001–7840)
References
External links
Intermediate spiral galaxies
Grus (constellation)
7072
066874
Astronomical objects discovered in 1834
Discoveries by John Herschel
287-031
21273-4322 | NGC 7072 | [
"Astronomy"
] | 262 | [
"Grus (constellation)",
"Constellations"
] |
54,568,128 | https://en.wikipedia.org/wiki/American%20Society%20of%20Biomechanics | The American Society of Biomechanics (ASB) is a scholarly society that focuses on biomechanics across a variety of academic fields. It was founded in 1977 by a group of scientists and clinicians. The ASB holds an annual conference as an arena to disseminate and learn about the most recent progress in the field, to distribute awards to recognize excellent work, and to engage in public outreach to expand the impact of its members.
Conferences
The society hosts an annual conference that takes place in North America (usually USA). These conferences are periodically joint conferences held in conjunction with the International Society of Biomechanics, the North American Congress on Biomechanics, and the World Congress of Biomechanics. The annual conference, when not partnered with another conference, receives around 700 to 800 abstract submissions per year, with attendees in approximately the same numbers. The first conference was held in 1977.
Often, work presented at these conferences achieves media attention due to the ‘public interest’ nature of the findings or that new devices are introduced there. Examples include:
the effect of tablet reading on cervical spine posture;
the squeak of the basketball shoe;
‘underwear’ to address back-pain;
recovery after exercise;
exoskeleton boots for joint pain during exercise;
how flamingos stand on one leg.
National Biomechanics Day
The ASB is instrumental in promoting National Biomechanics Day, which has received international recognition.
In New Zealand, Massey University attracted NZ$48,000 of national funding
through the Unlocking Curious Minds programme to promote National Biomechanics Day, with the aim to engage 1,100 students from lower-decile schools in an experiential learning day focused on the science of biomechanics.
It was first held in 2016 on April 7, and consisted of ‘open house’ visits from middle and high school students to biomechanics research and teaching laboratories across the US.
In 2017, National Biomechanics Day was held on April 6. An estimated 7000+ number of high school students participated in events around USA and internationally
with significant media attention
International participation was recognised from Australia, Belgium, Brazil, Canada, England, Ireland, New Zealand, South Africa, and Taiwan.
Awards
The society grants a number of annual awards both honouring individuals in the field, and honouring notable research projects. The most notable of these is the Borelli Award, which has been awarded annually since 1984 for outstanding career accomplishment in any field of biomechanics. Past winners include:
The ASB Grants for Diversity, Equity, and Inclusion (GRADE) grant program was created by the American Society of Biomechanics Diversity Committee to enhance recruitment and retention efforts of underrepresented populations in biomechanics. The grant supports diversity, equity, and inclusion (DEI) educational, research, and capacity-building initiatives provided by biomechanics organizations and awards amounts up to $5000.
References
Conferences in the United States
Biomechanics
Learned societies of the United States
1977 establishments in the United States | American Society of Biomechanics | [
"Physics"
] | 623 | [
"Biomechanics",
"Mechanics"
] |
54,568,728 | https://en.wikipedia.org/wiki/RigExpert | Rig Expert Ukraine Ltd is a manufacturer of ham and PMR Two-way radio RF antenna analysis and antenna tuning equipment. The company was founded in 2003 and is headquartered in Kyiv, Ukraine.
Current products
The AA-30, AA-54 & AA-170 are almost the same product except for the frequency range. Similarly, the AA-600, AA-1000 & AA-1400 are the same product except for the different frequency range.
See also
Antenna analyzer
Antenna tuner
Impedance matching
References
External links
Ukraine:
USA: (website has been closed, May 2022)
Canada:
UK:
Electrical circuits
Radio electronics
Impedance measurements
Electronic test equipment manufacturers | RigExpert | [
"Physics",
"Engineering"
] | 133 | [
"Radio electronics",
"Physical quantities",
"Electronic engineering",
"Electrical engineering",
"Impedance measurements",
"Electrical resistance and conductance",
"Electrical circuits"
] |
77,519,147 | https://en.wikipedia.org/wiki/NGC%205915 | NGC 5915 is a barred spiral galaxy in the constellation of Libra. Its velocity with respect to the cosmic microwave background is 2449 ± 13 km/s, which corresponds to a Hubble distance of 36.12 ± 2.54 Mpc (∼118 million light-years). It was discovered by British astronomer John Herschel on 5 June 1836.
NGC 5915 forms a galaxy triplet due to gravitational interactions with NGC 5916 and NGC 5916A (also known as PGC 54779).
One supernova has been observed in NGC 5915: SN 2023cpt (type Ic, mag 17.1) was discovered by ATLAS on 27 February 2023.
See also
List of NGC objects (5001–6000)
References
External links
5915
54816
Libra (constellation)
Astronomical objects discovered in 1836
Discoveries by John Herschel
-02-39-019
Barred spiral galaxies
UGCA objects | NGC 5915 | [
"Astronomy"
] | 192 | [
"Libra (constellation)",
"Constellations"
] |
77,522,420 | https://en.wikipedia.org/wiki/Disorders%20of%20diminished%20motivation | Disorders of diminished motivation (DDM) are a group of disorders involving diminished motivation and associated emotions. Many different terms have been used to refer to diminished motivation. Often however, a spectrum is defined encompassing apathy, abulia, and akinetic mutism, with apathy the least severe and akinetic mutism the most extreme.
DDM can be caused by psychiatric disorders like depression and schizophrenia, brain injuries, strokes, and neurodegenerative diseases. Damage to the anterior cingulate cortex and to the striatum, which includes the nucleus accumbens and caudate nucleus and is part of the mesolimbic dopamine reward pathway, have been especially associated with DDM. Diminished motivation can also be induced by certain drugs, including antidopaminergic agents like antipsychotics, selective serotonin reuptake inhibitors (SSRIs), and cannabis, among others.
DDM can be treated with dopaminergic and other activating medications, such as dopamine reuptake inhibitors, dopamine releasing agents, and dopamine receptor agonists, among others. These kinds of drugs have also been used by healthy people to improve motivation. A limitation of some medications used to increase motivation is development of tolerance to their effects.
Definition
Disorders of diminished motivation (DDM) is an umbrella term referring to a group of psychiatric and neurological disorders involving diminished capacity for motivation, will, and affect.
A multitude of terms have been used to refer to DDM of varying severities and varieties, including apathy, abulia, akinetic mutism, athymhormia, avolition, amotivation, anhedonia, psychomotor retardation, affective flattening, akrasia, and psychic akinesia (auto-activation deficit or loss of psychic self-activation), among others. Other constructs, like fatigue, lethargy, and anergia, also overlap with the concept of DDM. Alogia (poverty of speech) and asociality (lack of social interest) are associated with DDM as well.
Often however, a spectrum of DDM is defined encompassing apathy, abulia, and akinetic mutism, with apathy being the mildest form and akinetic mutism being the most severe or extreme form. Akinetic mutism involves alertness but absence of movement and speech due to profound lack of will. People with the condition are indifferent even to biologically relevant stimuli such as pain, hunger, and thirst.
Causes
Less extreme forms of DDM, for instance apathy or anhedonia, can be a symptom of psychiatric disorders and related conditions, like depression, schizophrenia, or drug withdrawal. More extreme forms of DDM, for instance severe apathy, abulia, or akinetic mutism, can be a result of traumatic brain injury (TBI), stroke, or neurodegenerative diseases like dementia or Parkinson's disease.
Reduction in motivation and affect can also be induced by certain drugs, such as dopamine receptor antagonists including D2 receptor receptor antagonists like antipsychotics (e.g., haloperidol) and metoclopramide and D1 receptor antagonists like ecopipam, dopamine-depleting agents like tetrabenazine and reserpine, dopaminergic neurotoxins like 6-hydroxydopamine (6-OHDA) and methamphetamine, serotonergic antidepressants like the selective serotonin reuptake inhibitors (SSRIs) and MAO-A-inhibiting monoamine oxidase inhibitors (MAOIs), and cannabis or cannabinoids (CB1 receptor agonists).
Damage to a variety of brain areas have been implicated in DDM. However, damage to or reduced functioning of the anterior cingulate cortex (ACC) and striatum have been especially implicated in DDM. The striatum is part of the dopaminergic mesolimbic pathway, which connects the ventral tegmental area (VTA) of the midbrain to the nucleus accumbens (NAc) of the ventral striatum and basal ganglia. Strokes affecting other striatal and basal ganglia structures, like the caudate nucleus of the dorsal striatum, have also been associated with DDM.
Treatment
DDM, like abulia and akinetic mutism, can be treated with dopaminergic and other activating medications. These include psychostimulants and releasers or reuptake inhibitors of dopamine and/or norepinephrine like amphetamine, methylphenidate, bupropion, modafinil, and atomoxetine; D2-like dopamine receptor agonists like pramipexole, ropinirole, rotigotine, piribedil, bromocriptine, cabergoline, and pergolide; the dopamine precursor levodopa; and MAO-B-selective monoamine oxidase inhibitors (MAOIs) like selegiline and rasagiline, among others. Selegiline is also a catecholaminergic activity enhancer (CAE), and this may additionally or alternatively be involved in its pro-motivational effects.
The dopamine D1 receptor appears to have an important role in motivation and reward. Centrally acting dopamine D1-like receptor agonists like tavapadon and razpipadon and D1 receptor positive modulators like mevidalen and glovadalen are under development for medical use, including treatment of Parkinson's disease and notably of dementia-related apathy. Centrally active catechol-O-methyltransferase inhibitors (COMTIs) like tolcapone, which are likewise dopaminergic agents, have been studied in the treatment of psychiatric disorders but not in the treatment of DDM. Genetic variants in catechol-O-methyltransferase (COMT) have been associated with motivation and apathy susceptibility, as well as with reward, mood, and other neuropsychological variables.
Besides in people with DDM, psychostimulants and related agents have been used non-medically to enhance motivation in healthy people, for instance in academic contexts. This has provoked discussions on the ethics of such uses.
A limitation of certain medications used to improve motivation, like psychostimulants, is development of tolerance to their effects. Rapid acute tolerance to amphetamines is believed to be responsible for the dissociation between their relatively short durations of action (~4hours for main desired effects) and their much longer elimination half-lives (~10hours) and durations in the body (~2days). It appears that continually increasing or ascending concentration–time curves are beneficial for prolonging effects, which has resulted in administration multiple times per day and development of delayed- and extended-release formulations. Medication holidays and breaks can be helpful in resetting tolerance.
Another possible limitation of amphetamine specifically is dopaminergic neurotoxicity, which might occur even at therapeutic doses.
Besides medications, various psychological and physiological processes, including arousal, mood, expectancy effects (e.g., placebo), novelty, psychological stress or urgency, rewarding and aversive stimuli, availability of rewards, addiction, and sleep amount, among others, can also context- and/or stimulus-dependently modulate or enhance brain dopamine signaling and motivation to varying degrees. Relatedly, the psychostimulant effects of amphetamine are greatly potentiated by environmental novelty in animals.
Related concepts
Attention deficit hyperactivity disorder (ADHD) often involves motivational deficits, and the ADHD academic Russell Barkley has referred to the condition as a "motivational deficit disorder" in various publications and presentations. However, ADHD has perhaps more accurately been conceptualized as a disorder of executive function and of directing or allocating attention and motivation rather than a global deficiency in these processes. People with ADHD are often highly motivated towards stimuli that interest them, not uncommonly experiencing a flow-like state called hyperfocus while engaging such stimuli. In any case, as with management of DDM, psychostimulants and other catecholaminergic agents are used in people with ADHD to treat their symptoms, including difficulties with attention, executive control, and motivation, and are clinically effective for such purposes. Amphetamines in the treatment of ADHD appear to have among the largest effect sizes in terms of effectiveness of any interventions (medications or forms of psychotherapy) used in the management of psychiatric disorders generally.
DDM (and ADHD) should not be confused with "motivational deficiency disorder" ("MoDeD"; "extreme laziness"), a fake or spoof disease created for humorous purposes in 2006 to raise awareness about disease mongering, overdiagnosis, and medicalization.
References
Emotions
Motivation
Neuropsychology
Pro-motivational agents
Psychopathological syndromes
Symptoms and signs of mental disorders
Symptoms and signs: Nervous system | Disorders of diminished motivation | [
"Biology"
] | 1,923 | [
"Ethology",
"Behavior",
"Motivation",
"Human behavior"
] |
77,523,036 | https://en.wikipedia.org/wiki/Alessioporus%20rubriflavus | Alessioporus rubriflavus is a species of fungus in the family Boletaceae. It was described in 2017 as the first North American member of the genus Alessioporus.
Description
The cap is red when young, becoming somewhat yellow with age, the pores are yellow, and the stem is yellow with red streaks. All parts stain blue when bruised. The taste is distinctively sour or acidic.
Range
The type locality is Elbert County, Georgia, and the species is known to range along the Atlantic seaboard from Florida at least to New York.
Habitat
This species is known from oak/pine woods, scrub, and sandy soil.
Etymology
The specific epithet is derived from Latin ruber, red, and flavus, yellow, referring to the colors of the fruiting body.
Taxonomy
As of 2024, the only other member of the genus is a European species: Alessioporus ichnusanus.
References
Fungi of North America
Boletaceae
Fungi described in 2017
Fungus species | Alessioporus rubriflavus | [
"Biology"
] | 205 | [
"Fungus stubs",
"Fungi",
"Fungus species"
] |
77,523,259 | https://en.wikipedia.org/wiki/NGC%207427 | NGC 7427 is a lenticular galaxy in the constellation of Pegasus. Its velocity with respect to the cosmic microwave background is 9336 ± 35 km/s, which corresponds to a Hubble distance of 137.70 ± 9.66 Mpc (∼449 million light-years). It was discovered by Russian astronomer Otto Wilhelm von Struve on 22 November 1865.
Supernovae
Two supernovae have been observed in NGC 7427:
SN 2019uzd (type Ia, mag 18.94) was discovered by the Automatic Learning for the Rapid Classification of Events (ALeRCE) on 16 November 2019.
SN 2023uma (type Ia, mag 18.13) was discovered by the Zwicky Transient Facility on 9 October 2023.
See also
List of NGC objects (7001–7840)
References
External links
7427
70091
Pegasus (constellation)
Astronomical objects discovered in 1865
+01-58-016
Lenticular galaxies
0521 | NGC 7427 | [
"Astronomy"
] | 197 | [
"Pegasus (constellation)",
"Constellations"
] |
77,524,208 | https://en.wikipedia.org/wiki/NGC%205988 | NGC 5988 is a large spiral galaxy in the constellation of Serpens. Its velocity with respect to the cosmic microwave background is 10697 ± 10km/s, which corresponds to a Hubble distance of . However, one non-redshift measurement gives a much larger distance of . It was discovered by American astronomer Lewis Swift on 17 April 1887.
NGC 5988 is a LINER galaxy, i.e. it has a type of nucleus that is defined by its spectral line emission which has weakly ionized or neutral atoms, while the spectral line emission from strongly ionized atoms is relatively weak.
One supernova has been observed in NGC 5988: SN 2023hbv (type II, mag 19.278) was discovered by ATLAS on 29 April 2023.
See also
List of NGC objects (5001–6000)
References
External links
5988
055921
09998
Serpens
18870417
Discoveries by Lewis Swift
+02-40-012
Spiral galaxies | NGC 5988 | [
"Astronomy"
] | 209 | [
"Constellations",
"Serpens"
] |
77,524,784 | https://en.wikipedia.org/wiki/NGC%201198 | NGC 1198 is an elliptical galaxy in the constellation of Perseus. Its velocity with respect to the cosmic microwave background is 1419 ± 14 km/s, which corresponds to a Hubble distance of 20.92 ± 1.48 Mpc (∼68 million light-years). It was discovered by French astronomer Édouard Stephan on 6 December 1880. This galaxy was also observed by the American astronomer Lewis Swift on 27 October 1888, and was later added to the Index Catalogue as IC 282.
One supernova has been observed in NGC 1198: SN 2024epr (type Ia, mag 19.3721) was discovered by the Zwicky Transient Facility on 19 March 2024.
See also
List of NGC objects (1001–2000)
References
External links
1198
IC objects
011648
02533
Perseus (constellation)
18801206
Discoveries by Édouard Stephan
Discoveries by Lewis Swift
+07-07-024
Elliptical galaxies | NGC 1198 | [
"Astronomy"
] | 195 | [
"Perseus (constellation)",
"Constellations"
] |
77,525,112 | https://en.wikipedia.org/wiki/National%20Development%20Plan%20%28Brunei%29 | The National Development Plan (NDP) or natively known as (RKN), is the name assigned by the government of Brunei to a plan designed to carry out Wawasan Brunei 2035 and diversify the economy by putting projects, programs, and initiatives into action. The RKN and planning were carried out under the direction of the Department of Economic Planning and Statistics (DEPS).
In 17 National Housing Scheme (RPN) zones covering a total area of , 30,296 homes were built under the Landless Indigenous Citizens' Housing Scheme (STKRJ) and the Land Scheme since the scheme's introduction in 1984. Under the two housing schemes, it has used land lots comprising hectares across four districts have been awarded since the program's inception in 1984. This information was disclosed on 9 February 2023. The program is administered and maintained nationally by the Housing Development Department (JKP).
Background
In the 16th century the Brunei empire was a prosperous and well-managed maritime power. But by the late 19th century, internal conflicts and abuses by foreign and local actors led to its decline, with Brunei approaching collapse by 1904. Widespread corruption, abuses of power, and a poorly planned system contributed to its deterioration, demonstrating how inadequate preparation and unclear future planning can severely undermine a state's stability.
During the British Residence period (1906–1959), Brunei experienced significant administrative and economic changes. With a population of around 20,000 between 1906 and 1941, it wasn't until the 1960s that Brunei's demographic size began to approach the approximately 25,000 people from the mid-1850s. The first British resident, Malcolm McArthur, played a crucial role in stabilising the country's governance and geographical order by implementing key reforms. He established police stations, civil and criminal courts, mail services, customs offices, and wharves. These foundational developments set the stage for Brunei's economic recovery and growth, even before the commercial exploitation of its oil resources. Subsequent British Residents observed rapid trade growth and the country's transition towards true prosperity following years of decline.The discovery and commercialisation of oil marked the beginning of a transformative period for Brunei. Among the top oil producing nations in the world by the 1930s was Brunei, particularly inside the British Commonwealth. Due to its economic growth, Brunei was able to shift from "rags to riches." But this progress was halted due to World War II. The Japanese occupation and subsequent Allied bombing strikes completely devastated Brunei. Seria's oil wells were set on fire, and Brunei Town was severely damaged, with just a Chinese temple still standing. With the sultanate in ashes, the war's devastation halted Brunei's economic growth.
Following the Second World War the government gave food distribution and the restoration of basic necessities first priority. Reconstruction of about 200 business houses and new government offices handled much of the war damage by early 1953 as rehabilitation activities got underway swiftly. During Sultan Omar Ali Saifuddien III's reign, Brunei saw substantial advancements in its political system and infrastructure. His assistance was essential in bringing Brunei from under British protectorate to full independence. The 1959 Constitution of Brunei, which abolished the British Resident's power and installed a British High Commissioner in its place, was one of his greatest accomplishments. By doing this, the Sultan was given his internal sovereignty back and became the ultimate executive head of government. The five-year national development plans were introduced by the Sultan to support Brunei's post-war reconstruction and modernisation.
RKN in the 20th century
RKN 1 (1953–1958)
Initiated in 1953 and spanning from 1953 to 1958, the first national development plan (RKN 1) played a crucial role in the transformation of Brunei. Prior to its establishment, Brunei was seen as a less developed and economically deprived country. The strategy signaled a paradigm change that helped Brunei become a nation with high GDP per person and a high standard of living. A "bloodless revolution" was how observers characterised the advancement because of the extent of the improvements made, which was especially remarkable considering Brunei's tiny population at the time. the nation's first 5-Year Development Plan was started when the State Council authorised $100 million for the five-year term, because of Sultan Omar Ali Saifuddin III's leadership. The principal objectives were to improve living conditions, modernise the nation while maintaining the framework of the Melayu Islam Beraja, raise Brunei's standing in Southeast Asia, and expand the non-oil and gas sector. To monitor the plan's execution, E. R. Bevington, a British expatriate from the Colonial Office in Fiji, was named Commissioner of Development.
The $100 million was distributed across a number of important projects:
Increasing access to healthcare and education
Putting relocation plans into action
Water supply
Enhancing fishing practices and agricultural practices
Extending communication networks and highways
Building structures such as bridges and power plants
Installing phone and television networks
Under RKN 1, infrastructure development received nearly 59% of the budget, with 21.77% going to welfare, health, and education. The plan gave increasing social welfare a lot of attention, which raised Bruneians' standard of life significantly. A pension plan for the disabled and those over 60 was one of the major social welfare projects implemented; it began in 1957 and paid $20 per month. Due to the plan's sustained emphasis on social welfare, qualified Bruneians now receive $250 each month, a testament to the program's enduring success. Important projects completed during this time were the building of new wharves at Brunei Town and Kuala Belait, the construction of the main road connecting Brunei to Tutong and Belait, and the preliminary design for a future port at Muara. In Brunei Town and Kuala Belait, automatic phone exchanges were installed, along with the Old Airport. In addition, a hospital and more than thirty new schools were constructed in Kuala Belait. The plan also highlighted the need for economic diversification away from the oil sector, putting out plans for things like improved waste gas use, improved agricultural practices, rubber replanting, and a sharper emphasis on the fishing sector.
More than 59.78% of the funding for the first national development plan was earmarked for building infrastructure, with 21.77% going toward welfare, health, and education. It acknowledged that Brunei's economy needed to be more diversified than only the oil sector. Initiatives including better using waste gas, enhancing agricultural practices, planting rubber again, and highlighting the fishing industry were all part of the plan. Despite this, the majority of attempts for economic diversity failed. The waste gas schemes for the production of cement, nitrogen fertiliser, aluminum, and other materials never came to be. After the Korean War, rubber prices fell, making replanting unsuccessful.
The concept also called for the construction of a deepwater Muara Port. The necessary power was obtained, and research was done to provide electricity to remote regions. Under the strategy, efforts were undertaken to eradicate malaria with the assistance of the World Health Organization. Malaria cases decreased from 300 in 1953 to just 66 in 1959 as a result of effective efforts. Additionally, from 20 deaths per thousand in 1947 to 11.3 deaths per thousand in 1953, the death rate was reduced. This has been linked to improvements in drainage, public cleanliness, and the availability of piped fresh water for the populace. The entire amount spent on education by 1958 was $4 million. With the development of new roads and the 1954 completion of Old Airport renovation, communications were also enhanced. Under the plan, a $14 million gas industrial facility was constructed.
By authorising the construction of mosques and suraus across Brunei, the Sultan also significantly contributed to the country's Islamic revival. His efforts were most notable for the 1958 opening of the Omar Ali Saifuddien Mosque, representing the Islamic tradition of Brunei. Brunei witnessed a transition under his direction that set the stage for its current identity and system of government.
Other than that, the government started relocating Kampong Ayer's population to the land in the 1950s with the goal of granting them the ability to own property and raise crops to support themselves. The first relocation plan was implemented in 1952 when Kampong Bunut Perpindahan was established. A second migration that resulted in the creation of Kampong Burong Pingai Berakas and Kampong Pancha Delima in 1953 came after this. The development of Kampong Pengiran Siraja Muda Delima Satu, Kampong Anggerek Desa, and Kampong Orang Kaya Besar Imas in 1954 marked the beginning of larger relocation efforts. With the founding of Kampong Jaya Setia and Kampong Jaya Bakti in 1960, Kampong Ayer underwent its third relocation plan.
RKN 2 (1962–1966)
Following the first plan, the second national development plan for 1962–1966 sought to advance social conditions and the economy. But prior to the start of RKN 3 in 1975, there existed a space. With a budget of $543 million, the RKN 2 seeks to advance and enhance Bruneians' social, cultural, and economic spheres of existence. The plan consists of fourteen clearly defined goals, such as:
Diversification of the economy
Increasing productivity to raise per capita income
Preserving a high degree of employment and a comparatively steady level of prices
Establishing a sufficient and all-encompassing national education system
Constructing a thorough national health system
Supplying sufficient infrastructure for public services
Encouraging and facilitating the private sector's involvement
A Planning Committee with representatives from several ministries was entrusted with creating their own plans for this plan, which was introduced four years after the first. The plan's formulation also involved input from eight advisory groups. Diversification and the reduction of regional growth inequalities were the main economic goals of NDP 2, with a sustained increase in per capita GDP being given top priority. A national health care, a comprehensive education system, and increased income distribution equity were among the other main objectives. With an emphasis on enhancing fisheries and forest productivity, as well as raising agricultural output through pilot projects for both new and current crops including coffee, groundnuts, and maize, the main objective was to provide necessary economic and social infrastructure.
As with RKN 1, transportation, communications, and infrastructure received around 54% of the entire budget, with housing and education receiving the greatest shares. NDP 2 had a B$492 million overall budget, but like the first plan, it had poor budget management, which led to significant spending increases, especially in education, where spending more than doubled between 1966 and 1968. The plan's timeline was greatly expanded; some of its actions persisted until the end of 1972.
RKN 2 primarily aims to further accelerate Brunei's social and economic advancement. The area devoted to commercial rice growing, which would strengthen the country's agricultural sector and reduce the need to import rice from outside, was one clear sign of economic progress. People can also learn how to cultivate other crops, such as wheat, peanuts, bananas, coffee, and others, for their own knowledge and as a consequence of exporting commodities abroad. Egg and meat output increased as part of the strategy. Throughout the strategy, the fishing sector boosted its productivity by 25%.
RKN 3 (1975–1979)
A total budget of $500 million was allotted to the third national development plan. The plan was developed and designed in accordance with the RKN 2 objectives in strengthening, improving, and further developing the economic, social, and cultural life of the people of Brunei. Preference was provided to the following goals:
Maintain a high level of employment
Diversify the economy through accelerated development of agriculture and industry
The plan was created between 1973 and 1975, a time when government revenues more than quadrupled. Consequently, the Economic Planning Unit was created in 1973 with the express intent of adopting measures for more stringent financial management as well as coordinating and overseeing development plans. The plan placed a strong emphasis on diversification as a means of resolving the structural imbalance in the economy, which was recognized as a crucial concern. This includes encouraging expansion in industries seen to be critical to the long-term viability of the economy, such as manufacturing, forestry, fisheries, and agriculture. Over the course of its execution, the plan sought to generate 10,000 new employment and a 6% annual GDP growth rate.
In order to draw in both international and domestic investment in industrial endeavors, the Economic Development Board was also established, based on Singapore's model, mainly by providing tax breaks and other advantages. Nevertheless, only a tiny percentage of financing went toward forestry, fishery, agricultural, and industrial initiatives, despite the intention of diversifying Brunei's economy. Instead, the majority of the funds were used to improve infrastructure, including roads, water supplies, telecommunications, healthcare, and education. Consequently, the GDP contribution of the non-oil sector stayed constant at about 20%, while the contributions of non-oil industry and agriculture actually decreased. A pulp mill, an ammonia-urea plant, and a glass manufacturing business were among the significant industrial undertakings that failed. The proposal had a total budget of B$533,554,000.
The Department of Relocation was established in 1970, and in 1976 it conducted a survey to determine the housing needs under the RPN, which was executed nationwide through the Department of Relocation. The concurrent reorganisation of agriculture and industry has been viewed in all development plans as the best way to address the imbalances in the economy. However, such language frequently conflicts with the real financial commitments made to support such a strategy. As a result, in RKN 3, real development spending allocated to the industry accounted for just 0.1% of the total ($760,000), as opposed to 1.8% ($9 million) that was anticipated.
RKN 4 (1980–1984)
The fourth national development plan, which has a $2.2 billion budget, has a strong emphasis on advancing and promoting the people's social, cultural, and economic well-being. There are four key components to this plan:
Political component that contributed to Brunei's independence in 1983 and was crucial to preserving the country's peace, security, and prosperity
Growing awareness of the need to preserve energy supplies as a result of the ongoing rise in oil prices
Shifting geopolitical conditions in the surrounding nations
Growing challenges in sourcing inexpensive immigrant labour from surrounding nations
NDP 4 was developed by taking into account the state's developments as well as the advantages and disadvantages of previous plans. In order to achieve an annual GDP growth rate of at least 6% and a yearly rise in per capita income of 4%, it implemented a number of fiscal and development initiatives. High employment rates, economic diversification through non-oil industries and agriculture, inflation management, income inequality reduction, education expansion, and the construction of rural clinics were among the goals of the plan. NDP 4's overall budget was B$1.75 billion, three times as much as NDP 3, while less was spent on forestry, industry, agriculture, and fisheries. The allocations for social services, health care, and education stayed the same, while almost 31% of the total was allocated to public building and security. Notwithstanding these initiatives, a downturn in oil output and prices caused the GDP to fall by more than 4%, although employment growth surpassed forecasts, increasing by almost 4.5 percent.
The plan was used by the government to launch the first RPN in the 1980s. Kampong Ayer's relocation plan was established in 1983 with the creation of RPN Serasa and Kampong Perpindahan Mata-Mata. The first pilot program for RPN Lambak Kanan was established in 1984.
RKN 5 (1986–1990)
With a budget of $3.7 billion, the fifth national development plan seeks to further the nation's social and economic advancement by offering a range of services and amenities that raised people's standards of living. The following strategies were established in the plan:
Maximising the nation's economic use of its natural resources
Increasing funding for the productive sectors
Quickening the development of human resources
Enhancing facilities for industrial development.
This plan, introduced after independence, had broader goals than its predecessors, emphasising economic diversification, human resource development, and fostering Bruneian entrepreneurship. With a budget of B$2,610,000, it allocated 10 percent to industrial development, aiming for a 10 percent annual increase in non-oil investments. To support this, institutions such as the Development Bank and programs like a National Training Scheme and an expanded Institute of Technology were planned, along with a National Pension Scheme. The plan achieved some success, with private sector employment rising from 29,973 in 1986 to 53,613 in 1990, and GDP increasing from B$22,963 to B$29,404. Two textile factories were also established, although the non-oil sector's contribution to GDP fell from 66.4 percent to 53.0 percent between 1986 and 1990. However, the National Pension Scheme and Development Bank did not materialise as intended.
The RKN 5 listed many areas where action was required and touched on some of the challenges faced by the industrial sector. A review of the land code, initiatives to support a class of Malay entrepreneurs (modeled after Malaysian New Economic Policy), the creation of a development bank, the establishment of a national employee provident fund or pension plan, and the rollout of a national training program were among them. Some other ideas that were put out were the privatization of some public services, the creation of public firms through direct involvement or joint ventures, and the offering of various incentives for the development of the private sector. It has been stated that the government will aggressively invest in high-risk areas, without naming specific businesses.
RKN 6 (1991–1995)
With a budget of $5.5 billion, the sixth national development plan seeks to address the demands of the nation, particularly with regard to raising the standard of living and enhancing the quality of life for its citizens while also bolstering the country's economy. The following goals were stressed in this RKN:
Enhance the development of human resources
Broaden the economic base and foster an environment that was conducive to industry
Maximising public sector spending
Maintaining the growth of the oil and gas industry
Promoting the creation of a robust private sector
Keeping the environment clean and healthful
Approximately 2,000 job-creation initiatives totaling B$5.5 billion were included in this plan with the goal of creating 40,000 job opportunities in the manufacturing, finance, and service sectors in order to create a sustainable and varied economic basis. As with earlier programs, encouraging the growth of the non-oil industry and lowering dependency on the government sector continued to be top priority. Along with building 11,000 new homes, the plan also called for enhancing water and electricity supplies, telecommunications, and electricity generating. To draw in more industrial investment, organisational modifications were implemented, such as the creation of a Trade and Industry Council in January 1992. In that year, Brunei dispatched a mission to Hanoi to examine bilateral economic cooperation, namely in Vietnam's growing offshore petroleum industry, which Brunei was interested in participating in, while trade delegations from Taiwan and Japan traveled to Brunei to look into investment potential.
Aiming to create 40,000 employment in the manufacturing, finance, and service sectors, B$5.5 billion was allotted to support around 2,000 projects in order to develop a sustainable and varied economic basis. Similar to earlier programs, the goal was to encourage the growth of non-oil sectors and lessen reliance on the government sector. In addition, the plan called for the building of 11,000 dwelling units, improvements to the water and energy delivery infrastructure, and telecommunications. To draw in more industrial investment, organisational modifications were implemented, such as the 1992 creation of a Trade and Industry Council. To look at potential investments, trade delegations from Taiwan and Japan traveled to Brunei in the same year.
RKN 7 (1996–2000)
Part of a 20-year long-term development program that started in 1985, the seventh national development plan had a budget of $7.2 billion. The objective of this plan was to raise the standard of living for Bruneians while highlighting the country's economic successes. With $1,402 million, or 19.5 percent of the overall allocation, the transport and communication sector is the third largest in RKN 7. The following strategies were established in the plan:
Balanced socioeconomic development
Ongoing environmental protection
Effective human resource development
Well-planned infrastructure and public facilities
Economic diversification
Execution of social development projects
"53% were completed, 12% were approaching completion and 12% were being implemented by the end of the plan period, whilst the remainder were either still at preliminary stages, suspended or cancelled for various reasons," according to RKN 7, which included 1,501 development programs and projects approved for implementation within this plan.
The government raised the Information Technology Division to a department in January 1996 and launched the (TEMA) for public services in 1995. To make internet access easier, the BruNet service was launched in 1995. Notable IT advancements during RKN 7 included the establishment of official and local organisation websites. In 2000, Brunei became the first country to issue a Smart Identification Card by using biometric technology and a "smart card." In an effort to encourage youngsters to use computers and the internet widely, the government also allotted $13.3 million in 2000 for ICT initiatives, including as improving the BruNet system and adding computers to government schools.
Between June 1996 and June 2000, there was a notable surge in the number of government agencies adopting IT services (from 36 to 40) and the quantity of IT equipment pieces (387,187). Additionally, there were 297 employees in the IT department, up from 201, and there were now one computer for every four users. Due to the dramatic increase in BruNet users from 819 in 1995 to 13,860 in 1999, the Brunei Telecom Department (JTB) partnered with UUNct in the United States in 2000 to improve internet access with increased bandwidth and quality. The 'pre-paid net card' for internet access and 'e-speed' for quicker data transfer were two ways that JTB improved BruNet services in 2000. 'SimpurNet' was introduced by DST, and three other firms (QAF Brunei, Royal Brunei Technical Services, and BIBD) were granted licenses to provide supplementary services during this time of rapidly expanding commercial IT services. The implementation of 'e-government' was started, and the National Information Technology Council (BIT) was formed to supervise IT use across the country.
As of 17 June 2000, of the 42 projects for the RKN 7, 21 projects totalling $201 million had been finished, while 13 projects totalling $567 million were awaiting clearance. A$800 million grant was given to the Department of Electrical Services (DES) to enhance the infrastructure for power production, transmission, and distribution. To solve serious problems, the agency first reinforced the 11,000-volt distribution infrastructure in the Brunei–Muara District. Installing new structures, pipelines, and main stations was one way to upgrade the infrastructure for supplying power. Two Main Electric Stations, 66/11KV Beribi in Kampong Kiarong and Tungku-2 in Kampong Rimba, were inaugurated as part of the project.
Under RKN 7 Brunei significantly increased its broiler production from 4,663 metric tons in 1996 to 12,507 metric tons in 2000, achieving an 86% surplus over local demand. Chicken egg production also exceeded targets, rising to 87 million eggs in 2000 from 82 million in 1999, surpassing the 73 million eggs required for self-sufficiency. This growth led to higher exports than domestic consumption.
During RKN 7, Brunei achieved a near-universal clean water supply, reaching 99.9% of the population. The country had the lowest water tariff rate among ASEAN members, and home water usage was the highest relative to its population of about 300,000. This abundance and low cost of water pose a risk of decreased awareness and economisation in its usage, despite the cheap supply.
RKN in the 21st century
RKN 8 (2001–2005)
Minister Ahmad claimed that the government was focusing on drafting laws and guidelines to simplify private sector management of development projects under the Private Financial Initiative (PFI) Scheme. Additionally, research were conducted to strengthen government finances, develop the downstream oil and gas industry, expand the private sector, and enhance strategic areas and infrastructure for industrialisation and privatisation. The government also aimed to raise productivity and develop human resources through the Department of Economic Planning and Development. RKN prioritised physical elements to improve the investment climate and business environment. RKN 8 seeks to reduce unemployment by creating approximately 18,000 new job opportunities across seven categories and over 17 job types for local youth by 2005.
The eighth national development plan, allocated $9.5 billion, concentrated on enhancing and growing the following:
Strengthening and expanding the oil and gas industry
Promoting economic diversification
Developing value-added industries to create new employment opportunities and boost exports
Human resource development
Creating a conducive environment for investment
Enhancing infrastructural facilities
Encouraging active participation from the private sector
In 2002, RKN 8 received a $1 billion commitment announced at the 2001 ASEAN Summit. Of this, $817.9 million was allocated to the transport and communication sector. This funding focuses on road safety initiatives, including the construction of a driving training facility, and the enhancement of telecommunications infrastructure. The plan also involves updating postal services, expanding BruNet's capacity, and developing fiber optic networks. These improvements aim to boost productivity through innovative methods, automate procedures, and enhance service delivery.
The Ministry of Communications Marine Department's priorities include enforcing maritime regulations, ensuring safety, protecting the environment, supporting the maritime industry, and developing human resources in maritime fields. As part of RKN 8, the Department of Civil Aviation plans to transform Brunei International Airport into a freight centre, offering new facilities and incentives. Meanwhile, Radio Television Brunei (RTB) implemented a master plan to introduce interactive TV, online broadcasting, and additional radio channels, supported by new studios and advanced digital TV equipment. Over RKNs 8 and 9, the Kota Batu Archaeological Park was constructed in stages. The Syariah and the Brunei Supreme Court building opened for business on 3 January 2006. It was constructed in 2001 at a total cost of more than B$14 million. It was finished in 2005. Constructed on a 10-acre area, the building has four stories and nine courtrooms, including two high court, one court of appeal, and six lower court chambers. Additionally, the plan included the Legislative Council building which began construction in March 2005.
Additionally, RKN 8 allocates $526 million, or 7.2% of the overall development budget, to advance information technology, including the creation of 'e-government' services and fundamental IT infrastructure. This initiative is expected to enhance communication tools and support various IT programs, driving advancements in e-commerce and economic development. By the end of RKN 8, 99.9% of respondents had access to clean water, compared to 99.7% in RKN 7.
RKN 2007–2012
The ninth national development plan was never referred to as RKN 9, it was officially known as RKN 2007–2012. RKN 10, however, was the tenth RKN to succeed it. In addition, The Sultan established the Long-term National Development Planning Board, whose job it was to create a development strategy and framework for a 30-year period starting with the 2006 fiscal year. The Long-term National Development Planning Board, led by Prince Mohamed Bolkiah, unveiled the plan on 17 February 2007. The plan sought to expand on the RKN 8, which prioritised economic diversification and allotted $7.3 billion, with a particular emphasis on small and medium-sized businesses and non-oil industries. Additionally, the RKN 8 made large investments in environmental and ICT projects. It was projected that the RKN 2007–2012 would direct the nation's economic growth over the ensuing five years, carrying on with initiatives to strengthen the non-oil economy, which had demonstrated notable expansion, especially in the services sector.
1,048 projects totalling $9.5 billion were approved by the government for implementation. The value of the system was split across the nine main sectors. With a $3,063 million allocation (32.3%) of the total plan value, the social services sector was given the largest share. The industry and commerce sector received $1,641 million (17.3%), while the public utilities sector received $1,316 million (13.9%). The development initiatives were public utilities, social services, environment, industry and commerce, tourism, transportation and communication, science, technology, and innovation, ICT, and security.
42.4% of the $9.5 billion value of the project was spent during the RKN period, or $4,031.1 million (77.6%) of the entire budget that was allotted. Over time, spending grew and reached a pinnacle in 2011, when it exceeded the $1 billion target with $1,024.5 million spent. The largest expenditure, amounting to $1,418 million (75.4%) of the budget, was in the social services sector, mostly because of the human resource development fund and large-scale housing initiatives. $804 million (87.0%) of the funds allotted to the industry and commerce sector went into industrial projects, such as the Sungai Liang Industrial Park. The public utilities sector spent $497 million (78.8%) of its allotted funds on projects related to the delivery of electricity and water, including the Ulu Tutong Dam and the Bukit Panggal Power Station.
A portion of the work in the Brunei–Muara District entails the formation and preparation of tender papers for the supply and installation of new pipes from Bukit Barun to the district; terminals for new reservoirs at Terunjing and Berakas; and the supply and installation of pipes from Melabau to Kota Batu. More housing projects, including relocation and public housing schemes, such as those in Rimba, Meragang, Bukit Beruang, Tanah Jambu, and Salambigar; resettlement schemes of Kampong Ayer to Lumapas 'A', Katok 'B' and Sungai Buloh/Tanah Jambu. Furthermore, other projects under the RKN consisted of the Agro-Technology Park, Kampong Ayer Cultural and Tourism Gallery, and the Suri Seri Begawan Raja Pengiran Anak Damit Mosque.
The Bangar Town Boat Terminal in the Temburong District, built at a cost of about $1.4 million, was constructed between 19 June 2008 and 19 December 2009, and officially opened on 7 January 2010. More projects to improve road infrastructure, including in the district, would be funded by the RKN 2007–2012. RKN also plans to increase the capacity of high-density roads in rural areas, replace wooden viaducts, and the Bangar–Puni–Labu Highway (Jalan Labu).
RKN 2007–2012 encountered a number of obstacles when carrying out its plans and initiatives, such as trouble obtaining project locations, frequent modifications to the scope of work, and hold-ups in project brief and tender document preparation. Project execution was made even more difficult by the protracted consultant hiring process, contractor-related problems, and the sluggish approval of change orders. The government implemented a number of initiatives to address these issues and improve implementation and expenditure rates. These included lowering bankers' guarantee rates to lessen financial constraints on contractors, creating an advisory board for consultant nominations for every ministry to expedite the process, and updating protocols for Variation Order approval. To expedite projects' completion, the government also promoted packaging, modified the procedure for tender approval, strengthened the internal technical staffing of ministries and departments, and enhanced the efficiency of project and program monitoring.
RKN 10 (2012–2017)
The RKN concept of "Knowledge and Innovation, Increase Productivity, Accelerated Economic Growth" guides the tenth national development plan, which focuses on developmental initiatives to achieve quicker and greater rates of growth in the economy. The budget for RKN 10 was $8.2 billion, with an additional $1.7 billion added to the total to further spur development. A total of $6.5 billion has been set aside for RKN 10. The following six strategies were established in the plan:
Educated and highly skilled population
High quality of life
Conducive business environment
Productive and progressive economy based on knowledge and innovation
Good governance and government modernisation
High quality and sustainable development infrastructure
RKN 10 saw the approval of 567 projects with a total scheme value of $8.2 billion by the government. The Temburong Bridge (Sultan Haji Omar Ali Saifuddien Bridge) project was transferred to RKN in Financial Year 2017–2018, extending the RKN 10 period until March 2018 and increasing the total number of projects to 568. The nine primary sectors each received a portion of the RKN 10 scheme value. The social services sector received the largest allocation of $2,621.3 million (31.9%) of the total scheme value. The public utilities sector came in second with roughly $1,409.5 million (17.1%) and the transportation and communications sector with roughly $1,293.6 million (15.7%).
Between the 568 approved projects, 465 (81.9%) were successfully completed; 30 (5.3%) were in the implementation stage; 39 (7.0%) were in the tendering stage; and 34 (5.7%) were in the design and planning stage. Other large projects like the Taman Mahkota Jubli Emas, recreational parks, the building of the flyover at the intersection of the Mengkubau Housing Highway and Muara Beach, the building of Jalan Gadong and Jalan Telanai, the building of the 4,000-unit housing project under the Mengkubau National Housing Scheme, and the renovation of the Brunei International Airport are among the completed projects.
Four large bridges to Temburong were planned and constructed. These comprised two new bridges, the Pandaruan Bridge which was supposed to be finished by late 2013 but had some minor delays when it crossed the Pandaruan River to link with Limbang, Malaysia. The Raja Isteri Pengiran Anak Hajah Saleha Bridge that link Bandar Seri Begawan to Kampong Lumapas on the Brunei River's eastern bank. In addition, the Brunei Economic Development Board (BEDB) helped to support the construction of the Pulau Muara Besar Bridge that connected Pulau Muara Besar to Muara. In August 2012, the BEDB issued a consulting contract to a joint venture consisting of Korean and Bruneians, with plans to issue a construction contract by mid-2013. The largest project, as previously mentioned, was the proposed Sultan Haji Omar Ali Saifuddien Bridge, which would have crossed the Brunei Bay to link Temburong with the mainland.
In order to promote technology and knowledge transfer, international contractors have collaborated with local businesses on BEDB's housing and infrastructure projects. Notable developments include TEE International's 1,500 apartments in Tutong, Bina Puri's 2,000 units in Kamoung Pandan, and UEM's 4,000 units in Kampong Mentiri. A joint venture between the Chinese company Third Harbour Engineering and the local company Surati Construction is overseeing the construction of the Telisai–Lumut highway, a significant infrastructure project that includes Brunei's biggest bridge to date—a 600-meter span across peat swamps—as well as an 18.6-kilometer dual carriageway.
$285.7 million under RKN 10 was allotted to the health sub-sector, of which $172.3 million was used to enhance technology use, treatment accessibility, and health infrastructure. The National Health and Medical Store Building, Rimba Health Center, Pharmacy Services Building, Tutong Dialysis Centre, the Women and Children Centre at Raja Isteri Pengiran Anak Saleha Hospital, and the Suri Seri Begawan Hospital's wards and facilities were among the noteworthy projects. Pengiran Anak Saleha opened the $64.5 million RIPAS Women and Children Centre on 22 April 2015, after it was finished on 30 September 2014. The first phase of the Agro Technology Park in Kampong Tungku, covering 50 hectares and scheduled for completion in January 2013, was part of Brunei's economic diversification strategy, focusing on agroindustry and halal product manufacturing, with the full 500 hectare project expected to create over 9,000 jobs, including more than 2,000 professional positions. Other projects included the first phase of the Mechanical Training Centre and the first phase of the dual carriageway Jerudong–Tungku Link Road (Tungku Highway), also expected to be completed in 2013. After that, the 5.5 km long third phase of the same highway was finished in 2016 at an estimated cost of $9.64 million.
The implementation of RKN 10 projects faced several obstacles, including a lack of suitable construction sites and frequent changes in project scopes. Delays in creating and assessing tender documents and conducting project briefings further hindered progress. The prolonged hiring process for experts and various issues related to contractors also contributed to these delays. Despite these challenges, RKN10 continues to support the Ease of Doing Business (EODB) initiative and the growth of the private sector, particularly Micro, Small, and Medium Enterprises (MSMEs), as noted in the 13th LegCo session in March 2017.
To enhance the implementation and oversight of the RKN 10 project, the government introduced initiatives requiring timely completion of projects, adherence to performance standards, and strict budget compliance. Payments had to follow project specifications, with additional funds subjected to rigorous inspection, while the RKN Project Management System emphasized value for money and average building prices. Effective oversight was maintained through regular site inspections, monthly meetings, and payment withholding for incomplete projects, with Prince Al-Muhtadee Billah supporting the program by frequently visiting project sites.
RKN 11 (2018–2023)
The eleventh national development plan, which has as its theme "Increased Non-Oil and Gas Sector Output as Catalysts for Economic Growth," further unifies developmental efforts in the non-oil and gas sector's production. With a $3.5 billion budget, it sought to stimulate economic growth by increasing the output of the non-oil and gas sector. Six strategic development pushes were the primary objectives of the plan:
Raising the standard of education and training to generate highly qualified and educated human capital
Growing the labor force to meet industry demands
Creating visionary and balanced (Wasatiah) communities
Enhancing the sustainable welfare of the populace
Raising the output and GDP contribution of the non-oil and gas sector
Fortifying government governance to foster a business-friendly environment
RKN 11 has been delayed to the fiscal year 2023–2024 so that ministries may finish off ongoing projects and get ready for RKN 12. A $500 million budget has been set out for 211 projects, including 28 new ones, for the fiscal year 2023–2024. On 27 March 2023, at the 19th Legislative Council (LegCo) session, this was announced. $31.3 million is set aside for planning, $14.7 million for final payments, $82.1 million for projects during bidding, $368.1 million for ongoing projects, and $3.8 million in reserve were all included in the budget. With an emphasis on industries including agrifood and development, the new initiatives were anticipated to increase GDP, promote digital transformation, and generate employment locally. As part of a larger $52.8 million plan, an additional $596,000 was set aside for disaster risk reduction, supplementing the $25 million previously set aside for handling natural disasters like floods and landslides.
To improve public welfare via the provision of secure, high-quality, and reasonably priced housing, the Ministry of Development (MoD) focus on overseeing and carrying out housing projects and fundamental infrastructure in compliance with current regulations. In 2023, the ministry set aside $3,066,320 for asset and estate management. Two housing projects under the RKN 11 are currently under construction: RPN Tanah Jambu Phase, which aims to build 7,950 terrace houses by January 2025, and Lugu Phase 2, which was expected to complete 1,000 terrace houses this year despite a seven-month delay caused by the COVID-19 pandemic in Brunei. Along with 270 of the 300 units in Lambak Kanan, 140 terrace houses in Rimba were finished in September 2022 and distributed to qualified applicants in 2023.
Noteworthy infrastructure projects including the Sultan Haji Omar Ali Saifuddien Bridge, improvements to Jalan Perindustrian Serasa, Kampong Lumut Drainage Scheme, and the Muara–Tutong Highway flyover at Kampong Lugu are among the significant completed projects. Current efforts include Schools Extension Building Project (Menglait Secondary School, UNISSA and the School of Applied Science and Mathematics in UTB Phase 4), and improving agriculture through programs for raising livestock and rice farming. 75 projects were being carried out as of March 2023, while 91 were in the planning or design stages. Notable budget commitments include $6 million for rice production in Kandol, $4.5 million for livestock development, and $1.9 million for the Government Data Center and Cloud Infrastructure project. Eleven projects have been canceled or refinanced. $19.8 million for educational infrastructure (Politeknik Brunei site in Ikas Bandung and the projected UNISSA campus in Temburong), while an additional $3.4 million committed to BruHIMS functionalities.
On 21 March 2024, during its 20th session, the LegCo adopted a $6.25 billion budget for the fiscal year 2024–2025. The RKN Executive Committee has approved 305 projects worth $4 billion to be finished by 2030. It also detailed the advancement of RKN 11, pointing out that 153 projects would be undertaken under RKN 12 and 54 projects have already been finished. The second phase of commercial rice farming in Kandol ($6 million of a $36 million budget), the renovation of Sultan Hassan Secondary School, the expansion of Menglait Secondary School, the electrical projects for the Gadong market area, and the building of a flyover at the intersection of the Muara–Tutong Highway and Kampong Lugu are some of the major initiatives. In addition, there are plans to construct the Jubli Perak Sengkurong Health Centre, renovate the Hassanal Bolkiah National Stadium, replace water pipes, and carry out digital transformation initiatives for the National Welfare System (SKN) and the Central Account Password Privilege Management Platform.
RKN 12
RKN 12 places a high priority on building infrastructure, especially in the housing sector, to promote growth in the economy. Numerous construction projects are currently under way, guided by RKN and the Construction Industry Framework 2022–2035 by the Authority for Building Control and Construction Industry (ABCi). Diverse specifications for design are ensured by adopting the Different Abilities Design Guideline, which is in accordance with the United Nations Convention on the Rights of Persons with Disabilities.
The budget for the fiscal year 2024–2025 supports RKN 12 and allots $4 billion for 305 projects till 2030. By tackling long-term socioeconomic goals, RKN 12 seeks to further Wawasan Brunei 2035. $1.7 billion will be granted to 153 projects from RKN 11 and $2.3 billion to 152 new initiatives. Amounts allocated for the 24th and 25th fiscal years total $500 million, with additional expenditures for research, development of industry, and environmental sustainability, as well as national security, education, housing, and infrastructure. To achieve successful execution and high-quality outputs, ministries, non-governmental organisations, and the private sector must collaborate on the expanded project scope.
See also
History of Brunei
Economy of Brunei
References
Citations
Sources
Economy of Brunei
Economic development
Human development
Social change
Government of Brunei | National Development Plan (Brunei) | [
"Biology"
] | 9,245 | [
"Behavioural sciences",
"Behavior",
"Human development"
] |
77,525,665 | https://en.wikipedia.org/wiki/WASP-178b | WASP-178b, also known as KELT-26b and HD 134004 b, is an ultra-hot Jupiter exoplanet discovered in 2019 orbiting WASP-178, a hot A-type star located about away in the constellation of Lupus. At over 1.8 times the radius of Jupiter, it is among the largest exoplanets. The planet is tidally locked, heating up one side of the planet to such a degree that silicate rock and metal evaporate. Supersonic winds blow constantly towards the dark, cooler nighttime side, where the vaporized minerals condense and fall as rain.
Discovery and nomenclature
The planet was discovered by a team of astronomers led by Coel Hellier, who published their findings in November 2019, alongside the detection of three other planets, designated WASP-184b, WASP-185b, and WASP-192b. The four planets were all found through photometric analysis of astronomical transit data collected by WASP-South, hence the "WASP-" prefix. For WASP-178b, data was gathered over the course of eight years between May 2006 and August 2014, which was combined with follow-up observations by the CORALIE spectrograph and EulerCam, which are both part of the Swiss 1.2-metre Leonhard Euler Telescope.
Another team, headed by Romy Rodríguez Martínez, independently announced discovering the planet in December 2019 as part of the Kilodegree Extremely Little Telescope (KELT) survey, labeling it KELT-26b. The host star was photometrically observed by the KELT-South telescope for two years between September 2013 and September 2015, identifying the object as a planetary candidate. Further observations confirmed the exoplanet, which were made by TESS, the Perth Exoplanet Survey Telescope (PEST), and the CHIRON spectrograph on the SMARTS 1.5 m telescope, located at the Cerro Tololo Inter-American Observatory (CTIO). The planet was the 26th and final planet discovered by the KELT survey before it was decommissioned in 2020.
Earlier designations of the host star include CD−42° 10057 in the Cordoba Durchmusterung catalogue and HD 134004 in the Henry Draper catalogue.
Physical properties
The planet orbits its host star every 3.34 days at a distance of , a mere one-seventh the radius of Mercury's orbit. This proximity to its host star, 20 times more luminous than the Sun, heats its atmosphere up to a white-hot equilibrium temperature of , comparable to the boiling point of silver (2,162 °C). Due to the intense irradiation, some of the highest even among the ultra-hot Jupiters, the planet's outer layers are inflated to an enormous 1.81 or 1.940 , making it one of the largest planets discovered so far alongside other hot Jupiters such as WASP-12b and Ditsö̀. This also means that the planet has a low density of 0.37 g/cm3 or 0.238 g/cm3, or about as light as cork (0.24 g/cm3).
The planet's geometric albedo was measured to be between 0.1 and 0.35 by utilizing CHEOPS photometry and was then further constrained to be below 0.23, implying that it has a poorly reflective surface typical of gas giants.
Atmosphere
The dayside temperature of WASP-178b is calculated at 2,250–2,750 K, which is sufficient to evaporate silicate rock, and above 2,500 K, break down hydrogen molecules into individual atoms. The planet's tidal locking causes the heated daylight side's atmosphere to blow across to the nighttime side at speeds of . On the nightside of the planet, the atomic hydrogen recouples back into molecular H2, and minerals that evaporated on the dayside may cool and condense into rock that pours down from clouds as rain.
In 2022, the discovery of silicon monoxide was reported on WASP-178b, the first time the compound was detected in an exoplanet, and consistent with theoretical predictions of silicate minerals at high temperatures. A follow-up study in 2024, however, concluded that the atmosphere is more likely dominated by ionized magnesium and iron rather than silicon monoxide.
Emission signals from the dayside of the planet as well as the result of eclipse observations strongly suggest the presence of an atmospheric super-rotation and indicate that the chemical composition of the dayside atmosphere may be uneven.
Host star
The host star, WASP-178, is a likely Am star and possibly a Delta Scuti variable, with a spectral type of A1IV-V meaning it is in between being a main sequence star and a subgiant. The star is comparable to Sirius A in mass and radius, but slightly cooler, older, and less luminous. It is about twice as massive as the Sun and has a radius of 1.67 or 1.80 , with an effective temperature of roughly 9,000 K. A 2019 estimate of makes WASP-178 the second-hottest host to a hot Jupiter ever discovered, behind KELT-9 (10,170 K) and ahead of MASCARA-2 (8,980 K), though a lower estimate (8,640 K) provided by another paper may put it below MASCARA-2. The star is around 20 times brighter than the Sun and is million years old.
Comparison with Sirius A
See also
KELT-9b
KELT-20b
Kepler-13Ab
MASCARA-1b
WASP-33b
WASP-189b
References
Lupus (constellation)
Transiting exoplanets
Exoplanets discovered in 2019
KELT-26b
Exoplanets discovered by WASP
Hot Jupiters | WASP-178b | [
"Astronomy"
] | 1,183 | [
"Constellations",
"Lupus (constellation)"
] |
77,526,605 | https://en.wikipedia.org/wiki/Cyber%20Security%20and%20Resilience%20Bill | On July 17th 2024, it was announced at the State Opening of Parliament
that the Labour government will introduce the Cyber Security and Resilience Bill (CS&R). The proposed legislation is intended to update the existing Network and Information Security Regulations 2018, known as UK NIS. CS&R will strengthen the UK's cyber defences and resilience to hostile attacks thus ensuring that the infrastructure and critical services relied upon by UK companies are protected by addressing vulnerabilities, while ensuring the digital economy can deliver growth.
The legislation will expand the remit of the existing regulations and put regulators on a stronger footing, as well as increasing the reporting requirements placed on businesses to help build a better picture of cyber threats. Its aim is to strengthen UK cyber defences, ensuring that the critical infrastructure and digital services which companies rely on are secure. The Bill will extend and apply UK-wide.
The new laws are part of the Government's pledge to enhance and strengthen UK cyber security measures and protect the digital economy. CS&R will introduce a comprehensive regulatory framework designed to enforce stringent cyber security measures across various sectors. This framework will include mandatory compliance with established cyber security standards and practices to ensure essential cyber safety measures are being implemented. Ultimately, businesses will need to demonstrate their adherence to these standards through regular audits and reporting. Also included in the legislation are potential cost recovery mechanisms to provide resources to regulators and provide powers to proactively investigate potential vulnerabilities.
Key facts
The key facts from the King's Speech are:
Consequences
It will introduce compulsory ransomware reporting so that the authorities can better understand the threat and "alert us to potential attacks by expanding the type and nature of incidents that regulated entities must report." While this information collection is likely to increase resilience to attacks, the administrative burden for businesses from this reporting might well bring with it additional costs as well as the original cyber incident's expense.
As modern business practices are interconnected, organisations must ensure that their partners and suppliers
also adhere to the standards set by the CS&R.
In the EU, the original Network and Information Security Directive (NIS Directive 2016/1148) is being updated to Directive 2022/2555, known as EU NIS 2. EU NIS 2 introduces wide-reaching changes to the existing EU cyber security laws for network and information systems. The CS&R should bring the existing UK NIS regulations 2018 to a framework similar to that of the EU.
The Bill as yet has no information on any punishments for non-compliance or what the data regulators' demands from an organisation that has experienced a cyber security incident will be.
Reaction
Jon Ellison, NCSC Director of National Resilience, said that the proposed bill was "a landmark moment tackling the growing threat to the UK's critical systems". He continued that it will be "a crucial step towards a more comprehensive regulatory regime, fit for our volatile world".
Former head of the NCSC Ciaran Martin along with other experts welcomed the legislative proposal. On social media, he wrote that the proposed legislation seemed sensible, with mandatory reporting requirements being significant and positive steps.
A representative of the CyberUp Campaign Matt Hull said that the organisation is looking forward to the Government updating UK cyber resilience and in particular the Computer Misuse Act 1990. Any updates to this Act would help cyber professionals protect the U.K., safeguard the digital economy and unlock the potential growth within the cybersecurity industry.
Schedule
The Bill will proceed through seven stages of the legislative process which happens in both houses of the UK parliament: first reading, second reading, committee stage, report stage, third reading, opposite house and royal assent.
July 17th Bill announced.
Stage: Pre-legislative Scrutiny (current).
Stage: First reading - The Bill will be introduced to Parliament in 2025.
See also
Cyber Resilience Act - EU regulation to improve cybersecurity and cyber resilience.
GDPR - The General Data Protection Regulation.
Malware - Examples include Computer viruses, spyware and adware.
References
External links
Cyber security in the UK Research Briefing - House of Commons Library
Cybercrime in the United Kingdom
Computer network security
Department for Science, Innovation and Technology
Internet security
Labour Party (UK)
Malware
Technology | Cyber Security and Resilience Bill | [
"Technology",
"Engineering"
] | 867 | [
"Malware",
"Cybersecurity engineering",
"Computer networks engineering",
"Computer network security",
"Computer security exploits"
] |
77,526,734 | https://en.wikipedia.org/wiki/MK-7845 | MK-7845 is an experimental antiviral medication being studied as a potential treatment for COVID-19. It is believed to work by inhibiting SARS-CoV-2 main protease (3CLpro), a crucial enzyme for viral replication.
Mechanism of action
MK-7845 functions as a reversible covalent inhibitor of the SARS-CoV-2 main protease (also known as 3CLpro or Mpro). This viral protease enzyme is critical for cleaving viral polyproteins into functional viral proteins necessary for viral replication. The unique cleavage site recognized by 3CLpro features a glutamine residue at the P1 position that is not utilized by human proteases, making it an attractive target for drug development. Unlike other covalent inhibitors that typically utilize an amide group as a glutamine mimic at this position, MK-7845 incorporates a difluorobutyl substituent. Research demonstrates that this modification interacts with the protease's His163 residue, a crucial component for the binding and inhibition of the enzyme.
Research
In vitro studies have demonstrated that MK-7845 exhibits nanomolar potency against a broad spectrum of clinical subvariants of SARS-CoV-2 as well as Middle East respiratory syndrome coronavirus (MERS-CoV). In vivo studies on transgenic mouse models, specifically K18-hACE2 mice (which express human ACE2 receptors) infected with SARS-CoV-2 and K18-hDDP4 mice infected with MERS-CoV, showed that giving MK-7845 by mouth significantly decreased the amount of virus in the lungs, by more than 6 log orders. Additionally, a study also observed that MK-7845 may offer prophylactic protection to mice when administered prior to exposure to the coronaviruses tested.
A process was developed to enable kilogram-scale production of MK-7845 in accordance with good manufacturing practices (GMPs). The production process was optimized to yield drug quantities suitable for safety studies and phase 1 clinical trials.
References
COVID-19 drug development
Experimental antiviral drugs | MK-7845 | [
"Chemistry"
] | 455 | [
"COVID-19 drug development",
"Drug discovery"
] |
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