Conodonts are extinct agnathan chordates resembling eels, classified in the class Conodonta. For many years, they were known only from tooth-like microfossils found in isolation and now called conodont elements. Knowledge about soft tissues remains limited; the animals are called Conodontophora to avoid ambiguity. Conodonts are considered index fossils, fossils used to identify geological periods; the conodonts first appeared during the Cambrian Stage 2. The still unnamed Cambrian Stage 10 can be defined as the first appearance of Eoconodontus notchpeakensis; the upper boundary is defined as the appearance of Iapetognathus fluctivagus which marks the beginning of the Tremadocian and is radiometrically dated as 485.4 ± 1.9 million years ago. The Cambrian–Ordovician extinction event occurred 488 million years ago; this early Paleozoic extinction event extirpated many conodonts. The Lau event, about 420 million years ago, a minor mass extinction during the Silurian period, had a major impact on conodont populations.
The Kačák Event was a period of significant extinctions. The group most affected was the Ammonoidea, although there were faunal turnovers amongst conodonts and dacryoconarids; the entire class is postulated to have been wiped out in the Triassic–Jurassic extinction event, which occurred 200 million years ago. Near the end of the Triassic deadly marine biocalcification began to occur, along with oceanic acidification, sea-level fluctuations and the Central Atlantic Magmatic Province releasing carbon dioxide, sulfur dioxide and aerosols; these environmental catastrophes caused the extinction of the conodonts, along with 34% of other marine genera. Conodonts were first discovered by Heinz Christian Pander, the results published, in Saint Petersburg, Russia, in 1856; the name pander is a common part, in scientific names of conodonts. The 11 known fossil imprints of conodont animals record an eel-like creature with 15 or, more 19 elements that form a bilaterally symmetrical array in the head; the organisms range from a centimeter or so to 40 cm in length.
It is now agreed that conodonts had large eyes, fins with fin rays, chevron-shaped muscles and a notochord. Conodont teeth are the earliest found in the fossil record; the evolution of mineralized tissues has been puzzling for more than a century. It has been hypothesized that the first mechanism of mammalian tissue mineralization began either in the oral skeleton of conodont or the dermal skeleton of early agnathans; the element array constituted a feeding apparatus, radically different from the jaws of modern animals. They are now termed "conodont elements" to avoid confusion; the three forms of teeth, i.e. coniform cones, ramiform bars, pectiniform platforms performed different functions. For many years, conodonts were known only from enigmatic tooth-like microfossils, which occur but not always in isolation, were not associated with any other fossil; until the early 1980s, conodont teeth had not been found in association with fossils of the host organism, in a konservat lagerstätte. This is because the conodont animal was soft-bodied, thus everything but the teeth was unsuited for preservation under normal circumstances.
These microfossils are made of hydroxylapatite. The conodont elements can be extracted from rock using adequate solvents, they are used in biostratigraphy. Conodont elements are used as paleothermometers, a proxy for thermal alteration in the host rock, because under higher temperatures, the phosphate undergoes predictable and permanent color changes, measured with the conodont alteration index; this has made them useful for petroleum exploration where they are known, in rocks dating from the Cambrian to the Late Triassic. The conodont apparatus may comprise a number of discrete elements, including the spathognathiform, trichonodelliform and other forms. In the 1930s, the concept of conodont assemblages was described by Hermann Schmidt and by Harold W. Scott in 1934; the feeding apparatus of ozarkodinids is composed at the front of an axial Sa element, flanked by two groups of four close-set elongate Sb and Sc elements which were inclined obliquely inwards and forwards. Above these elements inward pointing M elements.
Behind the S-M array lay transversely oriented and bilaterally opposed Pb and Pa elements. The "teeth" of some conodonts have been interpreted as filter-feeding apparatuses, filtering plankton from the water and passing it down the throat. Others have been interpreted as a "grasping and crushing array"; the lateral position of the eyes makes it unlikely. The preserved musculature suggests that some conodonts were efficient cruisers, but incapable of bursts of speed. A study on the population dynamics of Alternognathus has been published. Among other things, it demonstrates that at least this taxon had short lifespans lasting around a month; as of 2012, scientists classify the conodonts in the phylum Chordata on the basis of their fins with fin rays, chevron-shaped muscles and notochord. Milsom and Rigby envision them as vertebrates similar in appearance to modern hagfish and lampreys, phylogenetic analysis suggests they are more derived than either of these groups. However, this analysis comes with one caveat: early forms of conodonts, the protoconodonts, appear to form a distinct clade from the paraconodonts and euconodonts.
Protoconodonts represent a stem group to the phylum that includes chaetognath worms.
A two-sided market called a two-sided network, is an intermediary economic platform having two distinct user groups that provide each other with network benefits. The organization that creates value by enabling direct interactions between two distinct types of affiliated customers is called a multi-sided platform. Two-sided networks can be found in many industries, sharing the space with traditional product and service offerings. Example markets include credit cards. Examples of well known companies employing two-sided markets include such organizations as American Express, eBay, Facebook, LinkedIn, Mall of America, Match.com, AIESEC, Monster.com, Sony. Benefits to each group exhibit demand economies of scale. Consumers, for example, prefer credit cards honored by more merchants, while merchants prefer cards carried by more consumers. Two-sided markets are useful for analyzing the chicken-and-egg problem of standards battles, such as the competition between VHS and Beta, they are useful in explaining many free pricing or "freemium" strategies where one user group gets free use of the platform in order to attract the other user group.
Two-sided markets represent a refinement of the concept of network effects. There are both cross-side network effects; each network effect can be either negative. An example of a positive same-side network effect is end-user PDF sharing or player-to-player contact in PlayStation 3; the concept of network effects was conceived independently by Geoffrey Parker and Marshall Van Alstyne to explain behavior in software markets and by Rochet & Tirole to explain behavior in credit card markets. The first known peer-reviewed paper on interdependent demands was published in 2000. Multi-sided platforms exist because there is a need of intermediary in order to match both parts of the platform in a more efficient way. Indeed, this intermediary will minimize the overall cost, for instance, by avoiding duplication, or by minimizing transaction costs; this intermediary will make possible exchanges that would not occur without them and create value for both sides. Two-sided platforms, by playing an intermediary role, produce certain value for both users that are interconnected through it, therefore those sides may both be evaluated as customers.
A two-sided network has two distinct user groups. Members of at least one group exhibit a preference regarding the number of users in the other group; each group's members may have preferences regarding the number of users in their own group. Cross-side network effects are positive, but can be negative. Same-side network effects may be either negative. For example, in marketplaces such as eBay or Taobao and sellers are the two groups. Buyers prefer a large number of sellers, meanwhile, sellers prefer a large number of buyers, such that the members in one group can find their trading partners from the other group. Therefore, the cross-side network effect is positive. On the other hand, a large number of sellers mean severe competition among sellers. Therefore, the same-side network effect is negative. Figure 1 depicts these relationships. Neither cross-side network effects nor same-side network effects are sufficient for an organization to be a MSP. Examining traditional supermarkets, it is clear that shoppers prefer higher number of suppliers and bigger variety of goods, while suppliers value higher number of buyers.
A supermarket does not qualify as an MSP because it does not enable direct contact between shoppers and suppliers. On the other hand, such network effects are not required for a firm to be seen as an MSP. One example is the situation in which niche event organizers implement a ticketing service managed by a small on-line ticket provider in their websites. Consumers affiliate with the on-line ticket provider only when they go to the website to buy the ticket. However, cross-side network effects and same-side network effects are common in MSPs. In two-sided networks, users on each side require different functionality from their common platform. In credit card networks, for example, consumers require a unique account, a plastic card, access to phone-based customer service, a monthly bill, etc. Merchants require terminals for authorizing transactions, procedures for submitting charges and receiving payment, "signage", etc. Given these different requirements, platform providers may specialize in serving users on just one side of a two-sided network.
A key feature of two-sided markets is the novel pricing strategies and business models. In order to attract one group of users, the network sponsor may subsidize the othe
Platform (2000 film)
Platform is a 2000 Chinese film written and directed by Jia Zhangke. The film is set in and around the small city of Fenyang, Shanxi province, from the end of the 1970s to the beginning of the 1990s, it follows a group of twenty-something performers as they face societal changes. The dialogue is a mixture of local speech Jin Chinese and Mandarin; the film has been called "an epic of grassroots". It is named after a popular song about waiting at a railway platform. Platform has garnered wide acclaim from critics in the years since its release, is named one of the greatest films of the 2000s; the film starts in 1979 in the wake of the Cultural Revolution. A theatre troupe of young adults in Fenyang performs state-approved material; the troupe includes Cui Minliang and his friends, Yin Ruijuan, Zhang Jun, Zhong Ping. Zhang and Zhong are together. Cui asks Yin if she is his girlfriend; the troupe leaves their hometown and travels throughout the country for several years during the 1980s. Yin becomes a tax collector.
The authorities find out about the illegal sexual relationship between Zhang and Zhong, Zhong leaves the group, never to return. As China undergoes massive social changes, the troupe alters their performances and starts to play rock music, they return to Fenyang. Cui, jaded by his years on the road, reunites with Yin. Wang Hongwei – Cui Minliang Zhao Tao – Yin Ruijuan Liang Jingdong – Zhang Jun Yang Tianyi – Zhong Ping Wang Bo – Yao Eryong Han Sanming – Sanming Platform was voted the second best film of the past decade by the Toronto International Film Festival's Cinematheque, by more than 60 film experts from around the world. Another film by Jia Zhangke, Still Life, was voted the third best film. Platform placed 32 on Slant Magazine's list of the 100 best films of the 2000s and was named as one of Sight & Sound's films of the 2000s; the film has a 79% rating on Rotten Tomatoes. Venice Film Festival, 2000 Netpac Award Three Continents Festival, 2000 Golden Montgolfiere Singapore International Film Festival, 2000 SFC Young Cinema Award Buenos Aires International Festival of Independent Cinema, 2001 Best Film Fribourg International Film Festival, 2001 Don Quixote Award FIPRESCI Prize Platform on IMDb Platform at AllMovie Platform at Rotten Tomatoes Postsocialist Grit An essay on ideology and aesthetics in Platform and Unknown Pleasures at Offscreen Journal
A forklift is a powered industrial truck used to lift and move materials over short distances. The forklift was developed in the early 20th century by various companies, including Clark, which made transmissions, Yale & Towne Manufacturing, which made hoists. Since World War II, the use and development of the forklift truck have expanded worldwide. Forklifts have become an indispensable piece of equipment in warehousing. In 2013, the top 20 manufacturers worldwide posted sales of $30.4 billion, with 944,405 machines sold. The middle nineteenth century through the early 20th century saw the developments that led to today's modern forklifts; the forerunners of the modern forklift were manually powered hoists. In 1906, the Pennsylvania Railroad introduced battery powered platform trucks for moving luggage at their Altoona, Pennsylvania train station. World War I saw the development of different types of material handling equipment in the United Kingdom by Ransomes, Sims & Jefferies of Ipswich; this was in part due to the labor shortages caused by the war.
In 1917, Clark in the United States began developing and using powered tractor and powered lift tractors in their factories. In 1919, the Towmotor Company, Yale & Towne Manufacturing in 1920, entered the lift truck market in the United States. Continuing development and expanded use of the forklift continued through the 1930s; the introduction of hydraulic power and the development of the first electric power forklifts, along with the use of standardized pallets in the late 1930s, helped to increase the popularity of forklift trucks. The start of World War II, like World War I before, spurred the use of forklift trucks in the war effort. Following the war, more efficient methods for storing products in warehouses were being implemented. Warehouses needed more maneuverable forklift trucks that could reach greater heights and new forklift models were made that filled this need. For example, in 1954, a British company named Lansing Bagnall, now part of KION Group, developed what was claimed to be the first narrow aisle electric reach truck.
The development changed the design of warehouses leading to narrower aisles and higher load stacking that increased storage capability. During the 1950s and 1960s, operator safety became a concern due to the increasing lifting heights and capacities. Safety features such as load backrests and operator cages, called overhead guards, began to be added to forklifts produced in this era. In the late 1980s, ergonomic design began to be incorporated in new forklift designs to improve operator comfort, reduce injuries and increase productivity. During the 1990s, exhaust emissions from forklift operations began to be addressed which led to emission standards being implemented for forklift manufacturers in various countries; the introduction of AC power forklifts, along with fuel cell technology, are refinements in continuing forklift development. Forklifts are rated for loads at a specified maximum weight and a specified forward center of gravity; this information is located on a nameplate provided by the manufacturer, loads must not exceed these specifications.
In many jurisdictions, it is illegal to alter or remove the nameplate without the permission of the forklift manufacturer. An important aspect of forklift operation is. While this increases maneuverability in tight cornering situations, it differs from a driver’s traditional experience with other wheeled vehicles. While steering, as there is no caster action, it is unnecessary to apply steering force to maintain a constant rate of turn. Another critical characteristic of the forklift is its instability; the forklift and load must be considered a unit with a continually varying center of gravity with every movement of the load. A forklift must never negotiate a turn at speed with a raised load, where centrifugal and gravitational forces may combine to cause a disastrous tip-over accident; the forklift is designed with a load limit for the forks, decreased with fork elevation and undercutting of the load. A loading plate for loading reference is located on the forklift. A forklift should not be used as a personnel lift without the fitting of specific safety equipment, such as a "cherry picker" or "cage".
Forklifts are a critical element of warehouses and distribution centers. It's imperative that these structures be designed to accommodate their safe movement. In the case of Drive-In/Drive-Thru Racking, a forklift needs to travel inside a storage bay, multiple pallet positions deep to place or retrieve a pallet. Forklift drivers are guided into the bay through guide rails on the floor and the pallet is placed on cantilevered arms or rails; these maneuvers require well-trained operators. Since every pallet requires the truck to enter the storage structure, damage is more common than with other types of storage. In designing a drive-in system, dimensions of the fork truck, including overall width and mast width, must be considered. Forklift hydraulics are controlled either with levers directly manipulating the hydraulic valves or by electrically controlled actuators, using smaller "finger" levers for control; the latter allows forklift designers more freedom in ergonomic design. Forklift trucks are available in many variations and load capacities.
In a typical warehouse setting most forklifts have load capacities between five tons. Larger machines, up to 50 tons lift capacity, are used for lifting heavier loads, including loaded shipping containers. In addition to a control to raise and lower the forks, the operator can
A Jumping platform is a occurring or human-made surface for people to jump from. It is situated above sufficiently deep water, or above mats, a box-spring mattress, piles of empty cardboard boxes, or other soft landing surfaces, or they may be used together with other means of dampening the impact. Children improvise platforms, either on a large scale or on a smaller scale. For cliff jumping, the platform is a simple clearing in the bushes and other vegetation along the cliff above a river, lake, or quarry. Sometimes railway bridges and other bridges are used as platforms, they can sometimes be distances up to 30 metres above the water. Abandoned quarries, deep ponds will have platforms, whether by design, or by improvisation of the people in the community. For example, platforms will be affixed to towers in abandoned rail yards, overlooking a deep pond. Many occurring platforms are unofficial, known among the children in a community. For example, the children are trespassing on quarry land, or the like, when they use the platforms.
The locals check the water to make sure it is deep enough and free of clutter, but there is always the danger of a dead fish or beverage can, branches, or the like floating near the surface of the water. Bad angle of entry can cause injury in the absence of clutter. Being knocked unconscious by the impact can lead to drowning. For cliff jumping, there are several techniques; the main technique involves landing in a pencil shape with hands at the sides or above the head. Keeping limbs in results in a freer and more painless entry. Pointed toes and closed mouth assist in a smooth jump; some prefer to jump with shoes or sandals, while others jump barefoot or naked. For larger jumps, the angle of entry is critical. To ensure that you always enter the water vertically, it is proper to jump leaning forward, keeping your point of entry in view. Extend your arms for balance; as you fall tuck in your arms, bring together your legs. A gradual backward rotation throughout the jump will bring you from your initial forward position to complete a vertical entry.
Common errors include backward over rotation and not tucking in arms or legs. Keep legs straight with a slight bend at the knees. Locking your legs when taking the pencil shape will cause impact on the knees; the highest jump that should be attempted is 30 metres
A computing platform or digital platform is the environment in which a piece of software is executed. It may be the hardware or the operating system a web browser and associated application programming interfaces, or other underlying software, as long as the program code is executed with it. Computing platforms have different abstraction levels, including a computer architecture, an OS, or runtime libraries. A computing platform is the stage. A platform can be seen both as a constraint on the software development process, in that different platforms provide different functionality and restrictions. For example, an OS may be a platform that abstracts the underlying differences in hardware and provides a generic command for saving files or accessing the network. Platforms may include: Hardware alone, in the case of small embedded systems. Embedded systems can access hardware directly, without an OS. A browser in the case of web-based software; the browser itself runs on a hardware+OS platform, but this is not relevant to software running within the browser.
An application, such as a spreadsheet or word processor, which hosts software written in an application-specific scripting language, such as an Excel macro. This can be extended to writing fully-fledged applications with the Microsoft Office suite as a platform. Software frameworks. Cloud computing and Platform as a Service. Extending the idea of a software framework, these allow application developers to build software out of components that are hosted not by the developer, but by the provider, with internet communication linking them together; the social networking sites Twitter and Facebook are considered development platforms. A virtual machine such as the Java virtual machine or. NET CLR. Applications are compiled into a format similar to machine code, known as bytecode, executed by the VM. A virtualized version of a complete system, including virtualized hardware, OS, storage; these allow, for instance, a typical Windows program to run on. Some architectures have multiple layers, with each layer acting as a platform to the one above it.
In general, a component only has to be adapted to the layer beneath it. For instance, a Java program has to be written to use the Java virtual machine and associated libraries as a platform but does not have to be adapted to run for the Windows, Linux or Macintosh OS platforms. However, the JVM, the layer beneath the application, does have to be built separately for each OS. AmigaOS, AmigaOS 4 FreeBSD, NetBSD, OpenBSD IBM i Linux Microsoft Windows OpenVMS Classic Mac OS macOS OS/2 Solaris Tru64 UNIX VM QNX z/OS Android Bada BlackBerry OS Firefox OS iOS Embedded Linux Palm OS Symbian Tizen WebOS LuneOS Windows Mobile Windows Phone Binary Runtime Environment for Wireless Cocoa Cocoa Touch Common Language Infrastructure Mono. NET Framework Silverlight Flash AIR GNU Java platform Java ME Java SE Java EE JavaFX JavaFX Mobile LiveCode Microsoft XNA Mozilla Prism, XUL and XULRunner Open Web Platform Oracle Database Qt SAP NetWeaver Shockwave Smartface Universal Windows Platform Windows Runtime Vexi Ordered from more common types to less common types: Commodity computing platforms Wintel, that is, Intel x86 or compatible personal computer hardware with Windows operating system Macintosh, custom Apple Inc. hardware and Classic Mac OS and macOS operating systems 68k-based PowerPC-based, now migrated to x86 ARM architecture based mobile devices iPhone smartphones and iPad tablet computers devices running iOS from Apple Gumstix or Raspberry Pi full function miniature computers with Linux Newton devices running the Newton OS from Apple x86 with Unix-like systems such as Linux or BSD variants CP/M computers based on the S-100 bus, maybe the earliest microcomputer platform Video game consoles, any variety 3DO Interactive Multiplayer, licensed to manufacturers Apple Pippin, a multimedia player platform for video game console development RISC processor based machines running Unix variants SPARC architecture computers running Solaris or illumos operating systems DEC Alpha cluster running OpenVMS or Tru64 UNIX Midrange computers with their custom operating systems, such as IBM OS/400 Mainframe computers with their custom operating systems, such as IBM z/OS Supercomputer architectures Cross-platform Platform virtualization Third platform Ryan Sarver: What is a platform
A diving platform or diving tower is a type of structure used for competitive diving. It consists of a vertical rigid "tower" with one or more horizontal platforms extending out over a deep pool of water. In platform diving, the diver jumps from a high stationary surface; the height of the platforms – 10 metres, 7.5 metres and 5 metres – gives the diver enough time to perform the acrobatic movements of a particular dive. There are additional platforms set at 1 metre. Diving platforms for FINA sanctioned meets must be 2 metres wide. Most platforms are covered by some sort of matting or non-slip surface to prevent athletes from slipping. All three levels of the platform are used in NCAA competition; each level offers a distinct degree of difficulty and therefore could yield different scores for divers. Diving began in the Olympics in 1904 for men, in what was called "fancy diving", believed variously to have been off a platform or off a springboard; the 10-meter dive began in the 1908 Olympics. Diving for women started in the 1912 Olympics for women, with the 10-meter dive.
In 2016, dives performed by competitors in 10 meter world competition included a 3-½ somersault tuck, a 3-½ somersault pike, a 2-½ somersault with 2½ twist, a forward 4-½ somersault, a forward reverse 3½ somersault. Springboard List of 10 meter diving platforms in the United States