title: Electrophysiology

text: Most current-clamp amplifiers provide little or no amplification of the voltage changes recorded from the cell. The "amplifier" is actually an electrometer, sometimes referred to as a "unity gain amplifier"; its main purpose is to reduce the electrical load on the small signals (in the mV range) produced by cells so that they can be accurately recorded by low-impedance electronics. The amplifier increases the current behind the signal while decreasing the resistance over which that current passes. Consider this example based on Ohm's law: A voltage of 10 mV is generated by passing 10 nanoamperes of current across 1 MΩ of resistance. The electrometer changes this "high impedance signal" to a "low impedance signal" by using a voltage follower circuit. A voltage follower reads the voltage on the input (caused by a small current through a big resistor). It then instructs a parallel circuit that has a large current source behind it (the electrical mains) and adjusts the resistance of that parallel circuit to give the same output voltage, but across a lower resistance.


title: Electrophysiology

text: This technique was developed by Erwin Neher and Bert Sakmann who received the Nobel Prize in 1991. Conventional intracellular recording involves impaling a cell with a fine electrode; patch-clamp recording takes a different approach. A patch-clamp microelectrode is a micropipette with a relatively large tip diameter. The microelectrode is placed next to a cell, and gentle suction is applied through the microelectrode to draw a piece of the cell membrane (the 'patch') into the microelectrode tip; the glass tip forms a high resistance 'seal' with the cell membrane. This configuration is the "cell-attached" mode, and it can be used for studying the activity of the ion channels that are present in the patch of membrane.


title: Electrophysiology

text: If more suction is now applied, the small patch of membrane in the electrode tip can be displaced, leaving the electrode sealed to the rest of the cell. This "whole-cell" mode allows very stable intracellular recording. A disadvantage (compared to conventional intracellular recording with sharp electrodes) is that the intracellular fluid of the cell mixes with the solution inside the recording electrode, and so some important components of the intracellular fluid can be diluted. A variant of this technique, the "perforated patch" technique, tries to minimize these problems.


title: Electrophysiology

text: Instead of applying suction to displace the membrane patch from the electrode tip, it is also possible to make small holes on the patch with pore-forming agents so that large molecules such as proteins can stay inside the cell and ions can pass through the holes freely. Also the patch of membrane can be pulled away from the rest of the cell. This approach enables the membrane properties of the patch to be analyzed pharmacologically. Patch-clamp may also be combined with RNA sequencing in a technique known as patch-seq by extracting the cellular contents following recording in order to characterize the electrophysiological properties relationship to gene expression and cell-type.


title: Electrophysiology

text: In situations where one wants to record the potential inside the cell membrane with minimal effect on the ionic constitution of the intracellular fluid a sharp electrode can be used. These micropipettes (electrodes) are again like those for patch clamp pulled from glass capillaries, but the pore is much smaller so that there is very little ion exchange between the intracellular fluid and the electrolyte in the pipette. The electrical resistance of the micropipette electrode is reduced by filling with 2-4M KCl, rather than a salt concentration which mimics the intracellular ionic concentrations as used in patch clamping. Often the tip of the electrode is filled with various kinds of dyes like Lucifer yellow to fill the cells recorded from, for later confirmation of their morphology under a microscope. The dyes are injected by applying a positive or negative, DC or pulsed voltage to the electrodes depending on the polarity of the dye.


title: Electrophysiology

text: An electrode introduced into the brain of a living animal will detect electrical activity that is generated by the neurons adjacent to the electrode tip. If the electrode is a microelectrode, with a tip size of about 1 micrometre, the electrode will usually detect the activity of at most one neuron. Recording in this way is in general called "single-unit" recording. The action potentials recorded are very much like the action potentials that are recorded intracellularly, but the signals are very much smaller (typically about 1 mV). Most recordings of the activity of single neurons in anesthetized and conscious animals are made in this way. Recordings of single neurons in living animals have provided important insights into how the brain processes information. For example, David Hubel and Torsten Wiesel recorded the activity of single neurons in the primary visual cortex of the anesthetized cat, and showed how single neurons in this area respond to very specific features of a visual stimulus. Hubel and Wiesel were awarded the Nobel Prize in Physiology or Medicine in 1981.


title: Electrophysiology

text: If the electrode tip is slightly larger, then the electrode might record the activity generated by several neurons. This type of recording is often called "multi-unit recording", and is often used in conscious animals to record changes in the activity in a discrete brain area during normal activity. Recordings from one or more such electrodes that are closely spaced can be used to identify the number of cells around it as well as which of the spikes come from which cell. This process is called spike sorting and is suitable in areas where there are identified types of cells with well defined spike characteristics.


title: Electrophysiology

text: If the electrode tip is bigger still, in general the activity of individual neurons cannot be distinguished but the electrode will still be able to record a field potential generated by the activity of many cells.


title: Electrophysiology

text: Extracellular field potentials are local current sinks or sources that are generated by the collective activity of many cells. Usually, a field potential is generated by the simultaneous activation of many neurons by synaptic transmission. The diagram to the right shows hippocampal synaptic field potentials. At the right, the lower trace shows a negative wave that corresponds to a current sink caused by positive charges entering cells through postsynaptic glutamate receptors, while the upper trace shows a positive wave that is generated by the current that leaves the cell (at the cell body) to complete the circuit. For more information, see local field potential.


title: Electrophysiology

text: Amperometry uses a carbon electrode to record changes in the chemical composition of the oxidized components of a biological solution. Oxidation and reduction is accomplished by changing the voltage at the active surface of the recording electrode in a process known as "scanning". Because certain brain chemicals lose or gain electrons at characteristic voltages, individual species can be identified. Amperometry has been used for studying exocytosis in the nervous and endocrine systems. Many monoamine neurotransmitters; e.g., norepinephrine (noradrenalin), dopamine, and serotonin (5-HT) are oxidizable. The method can also be used with cells that do not secrete oxidizable neurotransmitters by "loading" them with 5-HT or dopamine.


title: Electrophysiology

text: Planar patch clamp is a novel method developed for high throughput electrophysiology. Instead of positioning a pipette on an adherent cell, cell suspension is pipetted on a chip containing a microstructured aperture.


title: Electrophysiology

text: With this electrophysiological approach, proteoliposomes, membrane vesicles, or membrane fragments containing the channel or transporter of interest are adsorbed to a lipid monolayer painted over a functionalized electrode. This electrode consists of a glass support, a chromium layer, a gold layer, and an octadecyl mercaptane monolayer. Because the painted membrane is supported by the electrode, it is called a solid-supported membrane. It is important to note that mechanical perturbations, which usually destroy a biological lipid membrane, do not influence the life-time of an SSM. The capacitive electrode (composed of the SSM and the absorbed vesicles) is so mechanically stable that solutions may be rapidly exchanged at its surface. This property allows the application of rapid substrate/ligand concentration jumps to investigate the electrogenic activity of the protein of interest, measured via capacitive coupling between the vesicles and the electrode.


title: Electrophysiology

text: The bioelectric recognition assay (BERA) is a novel method for determination of various chemical and biological molecules by measuring changes in the membrane potential of cells immobilized in a gel matrix. Apart from the increased stability of the electrode-cell interface, immobilization preserves the viability and physiological functions of the cells. BERA is used primarily in biosensor applications in order to assay analytes that can interact with the immobilized cells by changing the cell membrane potential. In this way, when a positive sample is added to the sensor, a characteristic, "signature-like" change in electrical potential occurs. BERA is the core technology behind the recently launched pan-European FOODSCAN project, about pesticide and food risk assessment in Europe. BERA has been used for the detection of human viruses (hepatitis B and C viruses and herpes viruses), veterinary disease agents (foot and mouth disease virus, prions, and blue tongue virus), and plant viruses (tobacco and cucumber viruses) in a specific, rapid (1–2 minutes), reproducible, and cost-efficient fashion. The method has also been used for the detection of environmental toxins, such as pesticides and mycotoxins in food, and 2,4,6-trichloroanisole in cork and wine, as well as the determination of very low concentrations of the superoxide anion in clinical samples.


title: Electrophysiology

text: A recent advance is the development of a technique called molecular identification through membrane engineering (MIME). This technique allows for building cells with defined specificity for virtually any molecule of interest, by embedding thousands of artificial receptors into the cell membrane.


title: Electrophysiology

text: While not strictly constituting an experimental measurement, methods have been developed to examine the conductive properties of proteins and biomembranes "in silico". These are mainly molecular dynamics simulations in which a model system like a lipid bilayer is subjected to an externally applied voltage. Studies using these setups have been able to study dynamical phenomena like electroporation of membranes and ion translocation by channels.


title: Electrophysiology

text: The benefit of such methods is the high level of detail of the active conduction mechanism, given by the inherently high resolution and data density that atomistic simulation affords. There are significant drawbacks, given by the uncertainty of the legitimacy of the model and the computational cost of modeling systems that are large enough and over sufficient timescales to be considered reproducing the macroscopic properties of the systems themselves. While atomistic simulations may access timescales close to, or into the microsecond domain, this is still several orders of magnitude lower than even the resolution of experimental methods such as patch-clamping.


title: Electrophysiology

text: Clinical electrophysiology is the study of how electrophysiological principles and technologies can be applied to human health. For example, clinical cardiac electrophysiology is the study of the electrical properties which govern heart rhythm and activity. Cardiac electrophysiology can be used to observe and treat disorders such as arrhythmia (irregular heartbeat). For example, a doctor may insert a catheter containing an electrode into the heart to record the heart muscle's electrical activity.


title: Electrophysiology

text: Another example of clinical electrophysiology is clinical neurophysiology. In this medical specialty, doctors measure the electrical properties of the brain, spinal cord, and nerves. Scientists such as Duchenne de Boulogne (1806–1875) and Nathaniel A. Buchwald (1924–2006) are considered to have greatly advanced the field of neurophysiology, enabling its clinical applications.


title: Electrophysiology

text: Minimum Information (MI) standards or reporting guidelines specify the minimum amount of meta data (information) and data required to meet a specific aim or aims in a clinical study. The "Minimum Information about a Neuroscience investigation" (MINI) family of reporting guideline documents aims to provide a consistent set of guidelines in order to report an electrophysiology experiment. In practice a MINI module comprises a checklist of information that should be provided (for example about the protocols employed) when a data set is described for publication.


title: Trivial File Transfer Protocol

text: Trivial File Transfer Protocol (TFTP) is a simple lockstep File Transfer Protocol which allows a client to get a file from or put a file onto a remote host. One of its primary uses is in the early stages of nodes booting from a local area network. TFTP has been used for this application because it is very simple to implement.


title: Trivial File Transfer Protocol

text: Due to its simple design, TFTP can be easily implemented by code with a small memory footprint. It is therefore the protocol of choice for the initial stages of any network booting strategy like BOOTP, PXE, BSDP, etc., when targeting from highly resourced computers to very low resourced Single-board computers (SBC) and System on a Chip (SoC). It is also used to transfer firmware images and configuration files to network appliances like routers, firewalls, IP phones, etc. Today, TFTP is virtually unused for Internet transfers.


title: Trivial File Transfer Protocol

text: TFTP's design was influenced from the earlier protocol EFTP, which was part of the PARC Universal Packet protocol suite. TFTP was first defined in 1980 by IEN 133.


title: Trivial File Transfer Protocol

text: In June 1981 The TFTP Protocol (Revision 2) was published as RFC 783 and later updated in July 1992 by RFC 1350 which fixed among other things the Sorcerer's Apprentice Syndrome. In March 1995 the TFTP Option Extension RFC 1782 updated later in May 1998 by RFC 2347, defined the option negotiation mechanism which establishes the framework for file transfer options to be negotiated prior to the transfer using a mechanism which is consistent with TFTP's original specification.


title: Trivial File Transfer Protocol

text: TFTP is a simple protocol for transferring files, implemented on top of the UDP/IP protocols using well-known port number 69. TFTP was designed to be small and easy to implement, and therefore it lacks most of the advanced features offered by more robust file transfer protocols. TFTP only reads and writes files from or to a remote server. It cannot list, delete, or rename files or directories and it has no provisions for user authentication.


title: Trivial File Transfer Protocol

text: In TFTP, a transfer is initiated by the client issuing a request to read or write a particular file on the server. The request can optionally include a set of negotiated transfer parameters proposed by the client under the terms specified by RFC 2347. If the server grants the request, the file is sent in fixed length blocks of 512 bytes by default or the number specified in the blocksize negotiated option defined by RFC 2348. Each block of transferred data, which is usually carried within a single IP packet in order to avoid IP fragmentation, must be acknowledged by an acknowledgment packet before the next block can be sent. A data packet of less than 512 bytes or the agreed blocksize option signals termination of a transfer. If a packet gets lost in the network, the intended recipient will timeout and may retransmit their last packet (which may be data or an acknowledgment), thus causing the sender of the lost packet to retransmit that lost packet. The sender has to keep just one packet on hand for retransmission, since the lock step acknowledgment guarantees that all older packets have been correctly received. Notice that both devices involved in a transfer are considered senders and receivers. One sends data and receives acknowledgments, the other sends acknowledgments and receives data.


title: Trivial File Transfer Protocol

text: TFTP uses UDP as its transport protocol. A transfer request is always initiated targeting port 69, but the data transfer ports are chosen independently by the sender and receiver during the transfer initialization. The ports are chosen at random according to the parameters of the networking stack, typically from the range of ephemeral ports.


title: Trivial File Transfer Protocol

text: TFTP has always been associated to network booting. One of the first attempts in this regard was the Bootstrap Loading using TFTP standard RFC 906, published in 1984, which established the 1981 published Trivial File Transfer Protocol standard RFC 783 to be used as the standard file transfer protocol for bootstrap loading. It was followed shortly after by the Bootstrap Protocol standard RFC 951 (BOOTP), published in 1985, which allowed a disk-less client machine to discover its own IP address, the address of a TFTP server, and the name of a Network Bootstrap Program (NBP) to be TFTP transferred, loaded into memory, and executed. Dynamic Host Configuration Protocol standard RFC 2131 (DHCP) published in 1997 improved BOOTP capabilities. Finally, the Preboot Execution Environment (PXE) version 2.0 was released in December 1998, and the update 2.1 was made public in September 1999 counting on TFTP as its file transfer protocol. Intel has recently decided to widely support PXE within the new UEFI specification extending the TFTP support to all EFI/UEFI environments.


title: Trivial File Transfer Protocol

text: The original protocol has a transfer file size limit of 512 bytes/block x 65535 blocks = 32 MB. In 1998 this limit was extended to 65535 bytes/block x 65535 blocks = 4 GB by TFTP Blocksize Option RFC 2348. If the defined blocksize produces an IP packet size that exceeds the minimum MTU at any point of the network path, IP fragmentation and reassembly will occur not only adding more overhead but also leading to total transfer failure when the minimalist IP stack implementation in a host's BOOTP or PXE ROM does not (or fails to properly) implement IP fragmentation and reassembly. If TFTP packets should be kept within the standard Ethernet MTU (1500), the blocksize value is calculated as 1500 minus headers of TFTP (4 bytes), UDP (8 bytes) and IP (20 bytes) = 1468 bytes/block, this gives a limit of 1468 bytes/block x 65535 blocks = 92 MB. Today most servers and clients support block number roll-over (block counter going back to 0 or 1 after 65535) which gives an essentially unlimited transfer file size.


title: Trivial File Transfer Protocol

text: Since TFTP utilizes UDP, it has to supply its own transport and session support. Each file transferred via TFTP constitutes an independent exchange. Classically, this transfer is performed in lock-step, with only one packet (either a block of data, or an 'acknowledgement') alternatively in flight on the network at any time. Due to this single data block strategy instead of sending a larger amount of uninterrupted data blocks before pausing the transfer to wait for the corresponding acknowledge (windowing), TFTP provides low throughput especially over high latency links. Microsoft introduced windowed TFTP in Windows 2008 as part of their Windows Deployment Services (WDS), in January 2015 TFTP Windowsize Option RFC 7440 was published. This substantially improves performance for things like PXE booting without the IP fragmentation side effect sometimes observed on Blocksize Option RFC 2348


title: Trivial File Transfer Protocol

text: TFTP includes no login or access control mechanisms. Care must be taken when using TFTP for file transfers where authentication, access control, confidentiality, or integrity checking are needed. Note that those security services could be supplied above or below the layer at which TFTP runs. Care must also be taken in the rights granted to a TFTP server process so as not to violate the security of the server's file system. TFTP is often installed with controls such that only files that have public read access are available via TFTP. Also listing, deleting, renaming, and writing files via TFTP are typically disallowed. TFTP file transfers are not recommended where the inherent protocol limitations could raise insurmountable liability concerns.


title: Start Me Up

text: "Start Me Up" is a song by the English rock band the Rolling Stones from their 1981 album "Tattoo You". Released as the album's lead single, it reached number one on Australian Kent Music Report, number two in Canada, number two on the "Billboard" Hot 100, number seven on the UK Singles Chart, and the top ten in a handful of European countries north of the Alps.


title: Start Me Up

text: The basic track "Start Me Up" was recorded during the January and March 1978 sessions for the Rolling Stones' album "Some Girls". The song began as a reggae-rock track named "Never Stop", but after dozens of takes it was abandoned. "Start Me Up" was not chosen for the album and was saved for later use. Richards commented:


title: Start Me Up

text: In 1981, with the band looking to tour, engineer Chris Kimsey proposed to lead singer Mick Jagger that archived songs could comprise the set. While searching through the vaults, Kimsey found the two takes of the song with a more rock vibe among some fifty reggae versions. Overdubs were completed on the track in early 1981 in New York City at the recording studios Electric Lady Studios and The Hit Factory. On the band's recording style for this track in particular, Kimsey commented in 2004:


title: Start Me Up

text: The infectious "thump" to the song was achieved using mixer Bob Clearmountain's famed "bathroom reverb", a process involving the recording of some of the song's vocal and drum tracks with a miked speaker in the bathroom of the Power Station recording studio in New York City. It was there where final touches were added to the song, including Jagger's switch of the main lyrics from "start it up" to "start me up."


title: Start Me Up

text: The song opens with what has since become a trademark riff for Richards. It is this, coupled with Charlie Watts' steady backbeat and Bill Wyman's echoing bass, that comprises most of the song. Lead guitarist Ronnie Wood can clearly be heard playing a layered variation of Richards' main riff (often live versions of the song are lengthened by giving Wood a solo near the middle of the song, pieces of which can be heard throughout the original recording). Throughout the song Jagger breaks in with a repeated bridge of "You make a grown man cry", followed by various pronouncements of his and his partner's sexual nature.


title: Start Me Up

text: Percussion (cowbell and guiro) by Mike Carabello and handclaps by Jagger, Chris Kimsey and Barry Sage were added during overdub sessions in April and June 1981.


title: Start Me Up

text: A music video was produced for the single, directed by Michael Lindsay-Hogg. According to Lindsay-Hogg's recollection, Jagger and Watts proposed the collaboration to him over lunch with Jagger particularly keen to emulate the style of video shown on MTV, which he regarded as "the future". The subsequent production became one of the most programmed videos of MTV's early years.


title: Start Me Up

text: "Start Me Up" peaked at number seven on the UK Singles Charts in September 1981 and remains the last Rolling Stones song to appear in the UK top 10. In Australia, the song reached number one in November 1981. In the US, "Start Me Up" spent three weeks at number two on the "Billboard" Hot 100 chart in October and November 1981, the Stones' biggest hit of the 1980s in the United States.


title: Start Me Up

text: It also spent 13 weeks atop the "Billboard" Top Tracks chart. This set a record for most weeks at #1 that was not broken until 1994, when Stone Temple Pilots' "Interstate Love Song" spent 15 weeks on top. The B-side is a slow blues number called "No Use in Crying", which is also included on "Tattoo You".


title: Start Me Up

text: "Start Me Up" is often used to open the Rolling Stones' live shows and has been featured on the live albums "Still Life" (recorded 1981, released 1982), "Flashpoint" (recorded 1989, released 1991), "Live Licks" (recorded 2003, released 2004), "Shine a Light" (recorded 2006, released 2008), and "Hyde Park Live" (2013). It also features on several Stones live concert films and DVD/Blu-ray sets: "Let's Spend the Night Together" (filmed 1981, released 1983), "Stones at the Max" (filmed 1990, released 1991), "" (filmed 1994, released 1995), "Bridges to Babylon Tour '97–98" (filmed 1997, released 1998), "Four Flicks" (2003), "The Biggest Bang" (filmed 2006, released 2007), "Shine a Light" (filmed 2006, released 2008), "Sweet Summer Sun: Hyde Park Live" (2013), and "" (2016, bonus track). The song was the first of three songs played by the Stones at halftime during Super Bowl XL in 2006.


title: Start Me Up

text: The song has been included on every major Stones compilation album since its release, including "Rewind (1971–1984)", "", "Forty Licks" and "GRRR!". Writing for AllMusic, Stewart Mason noted, "there were hits after 'Start Me Up,' but at this remove, it's undeniable that this 1981 single was the last great Rolling Stones song." "Rolling Stone" magazine ranked it the 8th Best Sports Anthem.


title: Start Me Up

text: Microsoft paid about US$3 million to use this song in their Windows 95 marketing campaign. This was the first time that the Rolling Stones allowed a company to use their songs in an advertising campaign. In 2012, a remixed version of the song was used as the soundtrack to an Omega advertising campaign for their role as official timekeepers of the 2012 Summer Olympics.


title: I Feel for You

text: "I Feel for You" is a song written by American musician Prince that originally appeared on his 1979 self-titled album. The most successful and best-known version was recorded by R&B singer Chaka Khan and appeared on her 1984 album of the same name. It became the recipient of two Grammy Awards for Best R&B Song (with Prince as its songwriter) and Best Female R&B Vocal Performance for Khan.


title: I Feel for You

text: Prince originally wrote "I Feel For You" and his hit single "I Wanna Be Your Lover" for musician Patrice Rushen, but she turned down both songs. Prince subsequently recorded them for his eponymous second album, which was released in October 1979. For the song, Prince uses a falsetto vocal with the melody range between C and D.


title: I Feel for You

text: The Pointer Sisters recorded the song in 1982 on their album "So Excited!", and Rebbie Jackson recorded it for her 1984 debut album "Centipede". In 1993, Britney Spears and Justin Timberlake sang this song on "The Mickey Mouse Club".


title: I Feel for You

text: In October 2019, in honor of the 40th anniversary of the album "Prince", the Prince Estate and Warner Records released a previously unheard solo acoustic demo recording of the song, with Prince also performing acoustic guitar. The track became available on streaming services and as a limited-run 7” vinyl single which sold out.


title: I Feel for You

text: Chaka Khan's version of "I Feel for You" featured a supporting cast including rapping from Melle Mel (of Grandmaster Flash and the Furious Five); guitar, drum programming, bass guitar, keyboards and arrangement by Reggie Griffin; bass synthesizer and programming by The System's David Frank using an Oberheim DSX sequencer, which was connected to his Minimoog via CV and gate; and chromatic harmonica playing by Stevie Wonder. The song also uses vocal samples from Wonder's song "Fingertips" (1963). The repetition of Khan's name by Melle Mel at the beginning of the song was a mistake made by producer Arif Mardin, who then decided to keep it.


title: I Feel for You

text: This version of the song sold more than one million copies in the US and UK, and it helped to relaunch Khan's career. The song hit No. 1 on the "Cash Box" singles chart and peaked at No. 3 on the "Billboard" Hot 100 chart from the weeks of November 24, 1984 to December 8, 1984, prevented by further chart movement by Prince's "Purple Rain" and Wham!'s massive hit "Wake Me Up Before You Go Go". The song remained on the "Billboard" Hot 100 for 26 weeks and became one of "Billboard"s five biggest pop songs of the year for 1985. The single reached No. 1 on both the US dance and R&B charts in late 1984, remaining atop both for three weeks each. In addition, the song also reached No. 1 on the UK Singles Chart, remaining there for three weeks from November 4–25, 1984. While touring with Prince in 1998 in support of her collaborative album, "Come 2 My House", Khan and Prince performed "I Feel for You" as a duet.


title: I Feel for You

text: Khan's version of the song is written in the key of G major with a tempo of 125 beats per minute in common time. Khan's vocals span from D to A in the song.


title: I Feel for You

text: The first version of the music video for Khan's song featured her working in a club with female dancers. As rap music and breakdancing were gaining popularity in mainstream pop culture at the time, the song was released and proved a success, so another version of the video, in an inner-city courtyard setting, was created. It featured Khan with a disc jockey and break dancers Shabba Doo, Boogaloo Shrimp, Bruno Falcon and Ana Sánchez, all of whom appeared in the movie "Breakin'". A remixed version of the video was created to match the 12" vinyl version of the single.


title: Agrasen Ki Baoli

text: Agrasen Ki Baoli (also known as "Ugrasen Ki Baoli"; ) is a 60-meter long and 15-meter wide historical step well in New Delhi, India.


title: Agrasen Ki Baoli

text: Located on Hailey Road, near Connaught Place, Jantar Mantar, it was designated a protected monument by the Archaeological Survey of India (ASI) under the Ancient Monuments and Archaeological Sites and Remains Act of 1958.


title: Agrasen Ki Baoli

text: Although there are no known historical records to prove who built the stepwell, it is believed that it was originally built by the legendary king Agrasen, and the present architecture hints at it being rebuilt in the 14th century during the Tughlag or Lodi period of the Delhi Sultanate. The Baoli is open daily from 9 AM to 5:30 PM.


title: Agrasen Ki Baoli

text: Baoli or bawdi, also referred to as baori or bauri, is a Hindi word (from Sanskrit or , ). In Rajasthan and Gujarat the words for step well include and . Water temples and temple step wells were built in ancient India. The earliest forms of step well and reservoir were also built in India in places like Dholavira as far back as the Indus Valley civilisation.


title: Agrasen Ki Baoli

text: This Baoli, with 108 steps, is among a few of its kind in Delhi. Three levels of the historic stepwell are visible. Each level is lined with arched niches on both sides. From an architectural perspective, this step well was probably rebuilt during the Tughlaq or Lodi period and is flanked by a small three-sided mosque towards the west.


title: Agrasen Ki Baoli

text: The location has been used to shoot scenes from various Bollywood films such as the blockbuster film "PK" starring Aamir Khan and "Sultan" starring Salman Khan. It was also featured in the 2017 Sridevi thriller "Mom". The step well also appeared on the second episode of "The Amazing Race Australia 2" in 2012.


title: Erlang Shen

text: Erlang Shen () or Erlang, also known as the Lord of Sichuan (), is a Chinese god with a third truth-seeing eye in the middle of his forehead.


title: Erlang Shen

text: Erlang Shen may be a deified version of several semi-mythical folk heroes who helped regulate China's torrential floods dating variously from the Qin, Sui, and Jin dynasties. A later Buddhist source identifies him as the second son of the Northern Heavenly King Vaishravana.


title: Erlang Shen

text: In the Ming semi-mythical novels "Creation of the Gods" and "Journey to the West", Erlang Shen is the nephew of the Jade Emperor. In the former, he assists the Zhou army in defeating the Shang. In the latter, he is the second son of a mortal and the Jade Emperor's sister Yaoji. In the legend, he is known as the greatest warrior god of heaven.


title: Erlang Shen

text: Some common representations of Erlang Shen include Yang Jian, Li Erlang, Yang Bliss and others. The representation of Erlang Shen as Yang Jian is most common in popular media.


title: Erlang Shen

text: According to the "Story about Li Bing and His Son in Harnessing the Rivers" in the "Records of Guansian", Li Erlang assisted his father in the construction of the complex irrigation system that prevented the Min River from flooding and irrigated the Chengdu Plain. In thanks for the prosperity that this brought to them, the local people elevated the father and son to gods and dedicated the Two Kings Temple in their honor.


title: Erlang Shen

text: Legend states that Governor Li Bing sent his son out to discover the source of the flooding. He spent a year exploring the county without success. One day whilst sheltering in a cave, he encountered a tiger which he slew and seven hunters who had witnessed this bravery agreed to join him in his quest.


title: Erlang Shen

text: The group finally came to a cottage on the outskirts of Guan County (modern Dujiangyan City). From within they heard the sound of an old woman crying. The woman was Grandma Wang and she told them that her grandson was to be sacrificed to an evil dragon who was the local river god. Li Erlang reported this to his father who devised a plan to capture the dragon.


title: Erlang Shen

text: The eight friends hid in the River God Temple and jumped out on the dragon when it arrived to claim its offering. The dragon fled to the river pursued by Li Erlang, who eventually captured it. Grandma Wang arrived with an iron chain and the dragon was secured in the pool below the Dragon-Taming Temple, freeing the region from floods.


title: Erlang Shen

text: Another legend tells of Li Erlang suppressing a fire dragon that lived in the mountains north of Dujiangyan by climbing to the top of Mount Yulei, turning into a giant and building a dam with 66 mountains then filling it with water from Dragon Pacifying Pool.


title: Erlang Shen

text: Erlang's mother, Princess Yaoji, was the goddess of the realm of desire in heaven. Her job was to limit the gods' mortal urges such as love, affection, greed, and ambition. When she pursued an evil dragon who broke free of its heavenly prison into the mortal realm and was injured by it, she fell in love with Yang Tianyou, a mortal scholar, who saved her life by giving her his own heart to replace the one the dragon damaged. They had three children: Yang Jiao, Yang Jian (Erlang Shen), and Yang Chan (Holy Mother of Hua Shan). When the Jade Emperor discovered her marriage, he sent his armies to kill her family and capture her. Only Erlang and his sister Yang Chan survived.


title: Erlang Shen

text: As Li Bing, the first hydraulic engineer in the Shu area, was the hero who stopped the flooding of the Min River by constructing the Dujiangyan. This somehow led to Li Bing being turned into a folk hero who defeated a river god in order to save his prefecture from being flooded, where this story had then associated him as a new river god that protected the local people in the area from floods. However, a discrepancy comes up that even though Li Bing/Erlang was known as Guankou Shen, the river that he is associated with is in Qianwei and not Guankou.


title: Erlang Shen

text: Another discrepancy is that Li Erlang had never appeared in any of the tales related to stopping the Min River. The first appearance of Li Erlang was in "Zhishui ji" by Li Ying of the Liang Dynasty.


title: Erlang Shen

text: Historically Li Bing was conferred an official title until the Five Dynasties period under the rule of the Shu kingdom. He rose to political power when the great flood that occurred on the twenty-sixth day of the eighth month in 920 AD was reported to the emperor by Daoist Du Guangting .


title: Erlang Shen

text: Many legends and novels often describe Erlang as Yang Jian, a nephew of the Jade Emperor. According to an ancient text, Erlang Baojuan, Yang Jian's mother, was the Jade Emperor's sister, Princess Yaoji who was imprisoned under Mount Tao because she violated the Heavenly Rules by marrying a human named Yang Tianyou. Many years later, her son Yang Jian cleaved Mount Tao using his axe, hoping to set his mother free. He did successfully rescue his mother after he chased away the sun by carrying a mountain on his back.


title: Erlang Shen

text: In the 2009 TV series "Prelude of Lotus Lantern", he was not successful in the rescue mission as his mother was quickly incinerated by ten of her nephews. A grieving Yang Jian slaughtered nine of the ten sun deities with his axe. Later, he was dissuaded from killing the last sun by the moon goddess Chang'e and married a Dragon Princess, though it was an unhappy marriage that ended in divorce. After divorcing the abusive Dragon Princess, Yang Jian went to the celestial realms to take up the position of the Judicial God (司法天神), being in charge of enforcing the heavenly laws throughout the three realms with an iron fist. Both these incidents are entirely modern theatrical adaptations of the old myth.


title: Erlang Shen

text: Erlang Shen is also identified with Zhao Yu, a hermit who lived on Mount Qingcheng and was appointed by Emperor Yang of Sui as Governor of Jiazhou. Zhao Yu is said to have set forth with 1000 men to defeat a flood dragon that had been tormenting the area. Upon reaching the river, Zhao Yu dived into the water with his double-edged sword and emerged holding the dragon’s head. Following his death, according to the "Chronicle of Changshu County", the region was once again plagued by flood and he was seen riding a white horse amidst the swirling currents. The locals built a temple enshrining Zhao Yu as the god Erlang and the floods were subdued.


title: Erlang Shen

text: Deng Xia is said to have been a general under Erlang who surpassed his predecessors in valor and defeated a flood dragon, receiving the title "Erlang Shen" and a temple in his honor at Zhongqingli in Hangzhou.


title: Erlang Shen

text: Erlang makes an appearance near the start of the classic "Journey to the West" by Wu Cheng'en. Erlang, who is titled as being either True Lord or Illustrious Sage, is the nephew of the Jade Emperor. Erlang made his first appearance when he had been ordered by the Jade Emperor (in which Erlang was also with his seven elite sages whom he called his brothers) to subdue Sun Wukong, who was to be punished for his havoc in heaven.


title: Erlang Shen

text: Throughout the course of Erlang's duel between Sun Wukong, Erlang had been the stronger adversary though Sun Wukong always managed to stay ahead and at times get the better of Erlang thanks to his quick wits. After many transformations that were performed in their duel (Sun Wukong fleeing as a fish; Erlang and Sun Wukong becoming larger birds, and so forth), near the conclusion of the battle, he managed to see through Sun Wukong's disguise (as a temple) using his third eye. He eventually defeated Wukong through teamwork with several other gods; Laozi personally had dropped his refined golden ring that had hit Sun Wukong on the head, giving Erlang a chance to bring him down, and Erlang's dog bit him in the leg. After Sun Wukong had been captured (to which Sun Wukong retorts that they are cowards for attacking from behind), he and his heavenly soldiers would burn random areas of Mount Huaguo. Erlang is seen again far later in the novel when he assists Sun Wukong through chance by fighting against a certain ancient Dragon King and his villainous son-in-law, a nine-headed demon.


title: Erlang Shen

text: In "Investiture of the Gods", Yang Jian (Yang Bliss) is a disciple of Yuding Zhenren, and he learned fighting and magical skills including the 72 earthly transformations. He first appeared during the time of the Diablo Brothers' attack on the Western Foothills. After hearing of the situation, Yang personally took the offensive against the brothers. During his duel against all four brothers, Yang deliberately allowed himself to be consumed by Diablo Long Life's flying mink (some sources say an elephant). Following the battle, Yang Jian suddenly reappeared before Jiang Ziya after killing the mink inside its stomach with his many transformations. To trick the Diablo Brothers, Yang Jian later transformed himself into Long Life's flying mink and stole Diablo Red's Havoc-Umbrella. Thus, Yang was renowned as the true reason for Jiang Ziya's victory over the Diablo Brothers at an overall point.


title: Erlang Shen

text: In the tale "Lotus Lantern" ("Bao Lian Deng"), Erlang had a sister known as the Holy Mother of Mount Hua ("Hua Shan"). She married a mortal man, Liu Yanchang, who was a scholar. Together, they had a son by the name of Chen Xiang. She was admonished by Erlang for this unlawful human-deity union and imprisoned under Mount Hua. When Chen Xiang came of age, he split the mountain with an axe to free his mother, but not before facing people who repeatedly tried to undermine his mission, most notably his own uncle Erlang.


title: Erlang Shen

text: In Chinese belief, he was a filial son that entered the Chinese underworld to save his deceased mother from torment and will punish unfilial children by striking them with thunder as a punishment, hence the Chinese parent saying "Being smitten by lightning for being unfilial and ungrateful" towards unruly children. A warrior deity, he wields a "Sān Jiān Liǎng Rèn Dāo" ( - "three-pointed, double-edged blade") and always has his faithful "Xiàotiān quǎn" ( - "Howling Celestial Dog") by his side. This dog also helps him subdue evil spirits.


title: Erlang Shen

text: Erlang Shen is mostly portrayed, whether in ancient legends or games or television, as a noble and powerful warrior god who slays and vanquishes demons and monsters in the mortal realm and who embodies justice and righteousness. He is shown to have vast, superhuman strength, being able to cleave an entire mountain with his axe to save his mother in just one stroke and being capable of 72 Transformations (sometimes said to be 73 Transformations), meaning he can transform into virtually anything he wants.


title: Erlang Shen

text: His main weapon of choice is his "three-pointed, double-edged lance" (), a long three-pointed spear with two cutting edges of a saber. This spear is powerful enough to penetrate and cleave through steel and stone like wool. Erlang wields the Divine Spear with unmatched skill and superior mastery, being an unstoppable force of destruction in battle when wielding said spear, having slain countless evil gods, monstrous demonic beasts, and vast, massive armies of demons and ogres with it. He is almost always accompanied by his faithful "Howling Celestial Dog" (), which has the ability to viciously attack, maul, and subdue demons and evil spirits.


title: Erlang Shen

text: Erlang Shen has also been portrayed as possessing a unique skill known as the "Nine Turns Divine Skill" (). It grants him vast, physical durability of undefined limits and nigh-invulnerability to conventional weapons and various magic spells. In the novel "Creation of the Gods", Erlang was shown to be completely impervious to hits from various powerful mystical objects due to this skill; he has emerged completely unscathed from mystical weapons and artifacts that have proven capable of severely injuring or even killing other immortals.


title: Erlang Shen

text: Erlang Shen, as a god that embodies justice, can execute "Heaven's Punishment" by calling down countless massive, devastating bolts of holy lightning to strike and totally disintegrate evil beings.


title: Erlang Shen

text: The third-eye on his forehead does not have a fixed name, though its most popular name currently is "The Eye of Heaven" (). It has the ability to differentiate truth from lies and see through deceptions and disguises. It may be used as an offensive weapon, being able to fire continuous, highly destructive blasts of light energy and/or divine fire.


title: Erlang Shen

text: The light and fire blasts from the third-eye possesses vast, almost immeasurable destructive power; enough power to utterly destroy and vaporize anything it hits, even powerful enough to shatter and disintegrate entire mountains or completely erase and obliterate hundreds of thousands of demons from existence in one go or even cripple and destroy immortals that have supposedly indestructible bodies.


title: Erlang Shen

text: Erlang Shen is a playable character in the RPG "League of Immortals" (), an action-adventure game that combines RPG and MOBA gameplay. He is known as only "Erlang" in the game and is of the Immortal Class(), which is strong against the Devil Class().


title: Erlang Shen

text: The playable character Exiled God () from the Asian MMORPG "Asura Online" () is based on Erlang Shen in appearance and skills. He is a melee fighter who mainly uses the spear but can also use the sword and crossbow. While most of his skills involves deadly combos with his spear, they include melee attacks with the Celestial Hound and ranged power attacks with his heavenly eye.


title: Erlang Shen

text: In the MOBA game "SMITE", he is a playable character who is a melee warrior and his title is "The Illustrious Sage". His is accompanied by his Howling Celestial Dog (his passive) and has abilities utilizing his signature traits: his first is his third eye, his second his spear, his third his 72 Transformations, and his ultimate the "Nine Turns Divine Skill".


title: Erlang Shen

text: In the 1973 animation "Chinese Gods", the likeness of Bruce Lee is used to portray him. Here he possesses the third eye, kills a dragon, and fights a shape-shifting priest.


title: Erlang Shen

text: In the "Gumballs&Dungeons" roguelike RPG for Android, Erlang Shen, accompanied by his dog Xiàotiān quǎn as a sidekick, is a playable character with the "Eye of Heaven" designed as a specific attack for him, causing damage and diminishing the defense of enemies.


title: Built environment

text: The term built environment refers to human-made conditions and is often used in architecture, landscape architecture, urban planning, public health, sociology, and anthropology, among others. These curated spaces provide the setting for human activity and were created to fulfill human desires and needs. The term can refer to a plethora of components including the traditionally associated buildings, cities, public infrastructure, transportation, open space, as well as more conceptual components like farmlands, damned rivers, wildlife management, and even domesticated animals.


title: Built environment

text: The built environment is made up of physical features. However, when studied, the built environment often highlights the connection between physical space and social consequences. It impacts the environment and how society physically maneuvers and functions, as well as less tangible aspects of society such as socioeconomic inequity and health. Various aspects of the built environment contribute to scholarship on housing and segregation, physical activity, food access, climate change, and environmental racism.


title: Built environment

text: There are multiple different components that make up the built environment. Below are some prominent examples of what makes up the urban fabric:


title: Built environment

text: Buildings are used for a multitude of purposes: residential, commercial, community, institutional, and governmental. Building interiors are often designed to mediate external factors and provide space to conduct activities, whether that is to sleep, eat, work, etc. The structure of the building helps define the space around it, giving form to how individuals move through the space around the building.


title: Built environment

text: Public infrastructure covers a variety of things like roads, highways, pedestrian circulation, public transportation, and parks.


title: Built environment

text: Roads and highways are an important feature of the built environment that enable vehicles to access a wide range of urban and non urban spaces. They are often compared to veins within a cardiovascular system in that they circulate people and materials throughout a city similar to how veins distribute energy and materials to the cells. Pedestrian circulation is vital for the walkability of a city and general access on a human scale. The quality of sidewalks and walkways have an impact on safety and accessibility for those using these spaces. Public transportation is essential in urban areas, particularly in cities and areas that have a diverse population and income range.


title: Built environment

text: Agricultural production accounts for roughly 52% of U.S. land use. Not only does population growth cause an expansion of cities, it also necessitates more agriculture to accommodate the demand for food for an expanding population.


title: Built environment

text: Built environment as a term was coined in the 1980s, becoming widespread in the 1990s and places the concept in direct contrast to the supposedly "unbuilt" environment. The term describes a wide range of fields that form an interdisciplinary concept that has been accepted as an idea since classical antiquity and potentially before. Through the study of anthropology, the progression of the built environment into what it is today has been able to be examined. When people are able to travel outside of urban centers and areas where the built environment is already prominent, it pushes the boundaries of said built environment into new areas. While there are other factors that influence the built environment, like advancements in architecture or agriculture, transportation allowed for the spread and expansion of the built environment.


title: Built environment

text: Agriculture, the cultivation of soil to grow crops and animals to provide food as well as products, was first developed about 12,000 years ago. This switch, also called the Neolithic Revolution, was the beginning of favoring permanent settlements and altering the land to grow crops and farm animals. This can be thought of as the start of the built environment, the first attempt to make permanent changes to the surrounding environment for human needs. The first appearance of cities was around 7500 BCE, dotted along where land was fertile and good for agricultural use. In these early communities, a priority was to ensure basic needs were being met. The built environment, while not as extensive as it is today, was beginning to be cultivated with the implementation of buildings, paths, farm land, domestication of animals and plants, etc. Over the next several thousand years, these smaller cities and villages grew into larger ones where trade, culture, education, and economics were driving factors. As cities began to grow, they needed to accommodate more people, as well as shifted from focusing on meeting survival needs to prioritizing comfort and desires – it is important to note that there are still many individuals today who do not have their basic needs met and this idea of a shift is within the framework of the evolution of society. This shift caused the built aspect of these cities to grow and expand to meet the growing population needs.


title: Built environment

text: The pinnacle of city growth was during the Industrial Revolution due to the demand for jobs created by the rise in factories. Cities rapidly grew from the 1880s to the early 1900s within the United States. This demand led individuals to move from farms to cities which resulted in the need to expand city infrastructure and created a boom in population size. This rapid growth in population in cities led to issues of noise, sanitation, health problems, traffic jams, pollution, compact living quarters, etc. In response to these issues, mass transit, trolleys, cable cars, and subways, were built and prioritized in an effort to improve the quality of the built environment. An example of this during the industrial revolution was the City Beautiful movement. The City Beautiful movement emerged in the 1890s as a result of the disorder and unhealthy living conditions within industrial cities. The movement promoted improved circulation, civic centers, better sanitation, and public spaces. With these improvements, the goal was to improve the quality of life for those living in them, as well as make them more profitable. The City Beautiful movement, while declined in popularity over the years, provided a range of urban reforms. The movement highlighted city planning, civic education, public transportation, and municipal housekeeping.


title: Built environment

text: The invention of cars, as well as train usage, became more accessible to the general masses due to the advancements in the steel, chemicals, and fuel generated production (hitory how 2nd rev changed). In the 1920s, cars became more accessible to the general public due to Henry Ford’s advances in the assembly line production. With this new burst of personal transportation, new infrastructure was built to accommodate. Freeways were first built in 1956 to attempt to eliminate unsafe roads, traffic jams, and insufficient routes. The creation of freeways and interstate transportation systems opened up the possibility and ease of transportation outside a person's city. This allowed ease of travel not previously found and changed the fabric of the built environment. New streets were being built within cities to accommodate cars as they became increasingly popular, railway lines were being built to connect areas not previously connected, for both public transportation as well as goods transportation. With these changes, the scope of a city began to expand outside its borders. The widespread use of cars and public transportation allowed for the implementation of suburbs; the working individual was able to commute long distances to work everyday. Suburbs blurred the line of city “borders”, the day-to-day life that may have originally been relegated to a pedestrian radius now encompassed a wide range of distances due to the use of cars and public transportation. This increased accessibility allowed for the continued expansion of the built environment.


title: Built environment

text: Currently, the built environment is typically used to describe the interdisciplinary field that encompasses the design, construction, management, and use of man-made physical influence as an interrelated whole. The concept also includes the relationship of these elements of the built environment with human activities over time—rather than a particular element in isolation or at a single moment in time, these aspects act together via the multiplier effect. The field today draws upon areas such as economics, law, public policy, sociology, anthropology, public health, management, geography, design, engineering, technology, and environmental sustainability to create a large umbrella that is the built environment.


title: Built environment

text: There are some in modern academia who look at the built environment as all encompassing, that there is no natural environment left. This argument comes from the idea that the built environment not only refers to that which is built, arranged, or curated, but also to what is managed, controlled, or allowed to continue. What is referred to as “nature” today can be seen as only a commodity that is placed into an environment that is constructed to fulfill the human will and desire. This commodity allows humans to enjoy the view and experience of nature without it inconveniencing their day-to-day life. It can be argued that the forests and wild-life parks that are held on a pedestal and are seemingly natural are in reality curated and allowed to exist for the enjoyment of the human experience. The planet has been irrevocably changed by human interaction. Wildlife has been hunted, harvested, brought to the brink of extinction, modified to fit human needs, the list goes on. This argument juxtaposes the argument that the built environment is only what is built, that the forests, oceans, wildlife, and other aspects of nature are their own entity.


title: Built environment

text: The term built environment encompasses a broad range of categories, all of which have potential impacts. When looking at these potential impacts, the environment, as well as people, are heavily affected.


title: Built environment

text: The built environment can heavily impact the public’s health. Historically, unsanitary conditions and overcrowding within cities and urban environments have led to infectious diseases and other health threats. Dating back to Georges-Eugene Haussmann's comprehensive plans for urban Paris in the 1850s, concern for lack of air-flow and sanitary living conditions has inspired many strong city planning efforts. During the 19th century in particular, the connection between the built environment and public health became more apparent as life expectancy decreased and diseases, as well as epidemics, increased. Today, the built environment can expose individuals to pollutants or toxins that cause chronic diseases like asthma, diabetes, and coronary vascular disease along with many others. There is evidence to suggest that chronic disease can be reduced through healthy behaviors like a proper active lifestyle, good nutrition, and reduced exposure to toxins and pollutants. Yet, the built environment is not always designed to facilitate those healthy behaviors. Many urban environments, in particular suburbs, are automobile reliant making it difficult or unreasonable to walk or bike places. This condition not only adds to pollution, but can also make it hard to maintain a proper active lifestyle. Public health research has expanded the list of concerns associated with the built environment to include healthy food access, community gardens, mental health, physical health, walkability, and cycling mobility. Designing areas of cities with good public health is linked to creating opportunities for physical activity, community involvement, and equal opportunity within the built environment. Urban forms that encourage physical activity and provide adequate public resources for involvement and upward mobility are proven to have far healthier populations than those that discourage such uses of the built environment.


title: Built environment

text: Features in the built environment present physical barriers which constitute the boundaries between neighborhoods. Roads and railways, for instance, play a large role in how people can feasibly navigate their environment. This can result in the isolation of certain communities from various resources and from each other. The placement of roads, highways, and sidewalks also determines what access people have to jobs and childcare close to home, especially in areas where most people do not own vehicles. Walkability directly influences community, so the way a neighborhood is built affects the outcomes and opportunities of the community that lives there. Even less physically imposing features, such as architectural design, can distinguish the boundaries between communities and decrease movement across neighborhood lines.


title: Built environment

text: The segregation of communities is significant because the qualities of any given space directly impact the wellbeing of the people who live and work there. George Galster and Patrick Sharkey refer to this variation in geographic context as "spatial opportunity structure," and claim that the built environment influences socioeconomic outcomes and general welfare. For instance, the history of redlining and housing segregation means that there is less green space in many Black and Hispanic neighborhoods. Access to parks and green space has been proven to be good for mental health which puts these communities at a disadvantage. The historical segregation has contributed to environmental injustice, as these neighborhoods suffer from hotter summers since urban asphalt absorbs more heat than trees and grass. The effects of spatial segregation initiatives in the built environment, such as redlining in the 1930s and 1940s, are long lasting. The inability to feasibly move from forcibly economically depressed areas into more prosperous ones creates fiscal disadvantages that are passed down generationally. With proper public education access tied to the economic prosperity of a neighborhood, many formerly redlined areas continue to lack educational opportunities for residents and, thus, job and higher-income opportunities are limited.


title: Built environment

text: The built environment has a multitude of impacts on the planet, some of the most prominent effects are greenhouse gas emissions and Urban Heat Island Effect.


title: Built environment

text: The built environment expands along with factors like population and consumption which directly impact the output of greenhouse gases. As cities and urban areas grow, the need for transportation and structures grows as well. In 2006, transportation accounted for 28% of total greenhouse gas emissions in the U.S. Building's design, location, orientation, and construction process heavily influence greenhouse gas emissions. Commercial, industrial, and residential buildings account for roughly 43% of U.S. CO2 emissions in energy usage. In 2005, agricultural land use accounted for 10%-12% of total human-caused greenhouse gas emissions worldwide.


title: Built environment

text: Urban Heat Islands are pockets of higher temperature areas, typically within cities, that effect the environment, as well as quality of life. Urban Heat Islands are caused by reduction of natural landscape in favor of urban materials like asphalt, concrete, brick, etc. This change from natural landscape to urban materials is the epitome of the built environment and its expansion.


title: Lil' Fizz

text: Dreux Pierre Frédéric (born November 26, 1985) better known by his stage name Lil' Fizz, is an American rapper, singer, songwriter and actor best known for being the youngest member and rapper of the R&B group B2K. Formerly, he starred on the television show "".


title: Lil' Fizz

text: Frédéric was born in New Orleans, Louisiana and raised in Los Angeles, California. He is of Louisiana Creole heritage.


title: Lil' Fizz

text: Known as the rapper of the group, Lil' Fizz was a member of B2K from 2000 to 2004. After the group broke up, he began his independent rap career.


title: Lil' Fizz

text: He reconnected with former fellow B2K member J-Boog and long time friend and business manager Damuer H. Leffridge to launch a new record label, Popular Entertainment. Under Popular Ent., they released a 5-song EP titled "Night Life", available for digital download on iTunes in September 2009.


title: Lil' Fizz

text: He has a son, Kameron, born in 2010, with Moniece Slaughter. He and Slaughter have both appeared on "" since its inception in 2014.


title: Lil' Fizz

text: In (2019), Fizz revealed that he was in a romantic relationship with Apryl Jones, who was a fellow Love & Hip Hop cast member and the ex-girlfriend and babies' mother of fellow B2K member Omarion. As of 2020, he and Apryl have ended their relationship. Lingering issues between the two were addressed in "", which was filmed in 2020 during the COVID-19 pandemic and aired in 2021.


title: Lil' Fizz

text: He also appeared in "Marriage Boot Camp: Hip-Hop Edition" in 2019 with his girlfriend at that time, Tiffany Campbell.


title: Grant Fuhr

text: Grant Scott Fuhr (born September 28, 1962) is a Canadian former ice hockey goaltender in the National Hockey League and former goaltending coach for the Arizona Coyotes, who is best remembered for a decade of stellar play for the Edmonton Oilers in the 1980s during which he won the Stanley Cup five times.


title: Grant Fuhr

text: In 2017, Fuhr was named one of the 100 Greatest NHL Players in history. He set a number of firsts for black hockey players in the NHL, including being the first to win the Stanley Cup and being the first inducted into the Hockey Hall of Fame.


title: Grant Fuhr

text: Fuhr was born to one Afro-Canadian parent and one First Nation-Canadian parent from the Enoch Cree Nation; he was adopted by parents Betty Wheeler and Robert Fuhr and raised in Spruce Grove, Alberta.


title: Grant Fuhr

text: In the mid-1970s, Fuhr played for the Enoch Tomahawks' hockey team. Fuhr's mother came from Enoch Cree Nation.


title: Grant Fuhr

text: In 1979, at the age of seventeen, Fuhr joined the Victoria Cougars of the WHL. After two outstanding seasons in Victoria, which included the league championship and a trip to the Memorial Cup in 1981, Fuhr was drafted eighth overall by the Edmonton Oilers in the 1981 NHL Entry Draft, on June 10, 1981.


title: Grant Fuhr

text: Fuhr played ten seasons for the Oilers, where he teamed up first with Andy Moog, then Bill Ranford to form one of the most formidable goaltending tandems in history, winning the Stanley Cup four times in five seasons (1983-84 through '87-88). Moog was given the starting job in the 1983 playoffs, and helped lead the Oilers to their first Stanley Cup Finals, though they were swept by the New York Islanders, who captured their fourth straight Stanley Cup. The next year general manager and head coach Glen Sather chose to go with Fuhr in the 1984 playoffs, though Fuhr was injured in the third game of the Stanley Cup Finals in a rematch against the Islanders when he collided with Pat LaFontaine, so Moog stepped in and led the Oilers to a series win. Thereafter, Fuhr remained the number one goaltender. Fuhr was also involved with the infamous goal where Steve Smith scored on his own net to cost the Oilers the '86 playoffs against the Calgary Flames. Fuhr was the team's starting goaltender on the first four teams, but was injured and did not play in the 1990 playoffs, when the Oilers won for the fifth time.


title: Grant Fuhr

text: In 1987, Fuhr played in goal for the NHL All-Stars in both games of the Rendez-Vous '87 series against the Soviet National Team. In 1987-88, Fuhr backstopped Canada to a victory at the Canada Cup, playing in all nine games, then played in 75 regular season and 19 playoff games. He won his only Vezina Trophy as the NHL's top goaltender that year and finished second in voting for the Hart Memorial Trophy as league MVP, behind Mario Lemieux and ahead of teammate Wayne Gretzky. He also played in the National Hockey League All-Star Game in 1984, 1985, 1986, 1988, and 1989. Fuhr's playoff success fed into his reputation as the supreme clutch goaltender of his era, and there was a period of time from 1987 through at least 1989 where Fuhr was often called "the best goaltender in the world".


title: Grant Fuhr

text: Fuhr was suspended by the NHL for 59 games of the 1990–91 season. Fuhr had come forward about his drug use after spending two weeks in a counselling centre in Florida. He admitted that he used "a substance" (not specifying whether or not it was cocaine) for some seven years, or most of the period that the Oilers rested at the top of the NHL. Details of Fuhr's drug use were supplied by his ex-wife, Corrine, who told the press in Edmonton that she often found cocaine hidden in his clothing and that she fielded numerous threatening telephone calls from drug dealers who had not been paid. These embarrassing details no doubt contributed to the one-year suspension handed down in September 1990 by NHL president John Ziegler, who called Fuhr's conduct "dishonorable and against the welfare of the league." After missing 59 games and entering a two-week rehab program, the suspension was lifted by the league on February 18, 1991. Once Fuhr was re-instated, fans of opposing teams taunted him at games with bags of sugar.


title: Grant Fuhr

text: On September 19, 1991, Fuhr was traded to the Toronto Maple Leafs in a seven-player deal. After a season and a half in Toronto, he was again traded, this time to the Buffalo Sabres, on February 2, 1993.


title: Grant Fuhr

text: In Buffalo, he played a role in the Sabres' dramatic first-round playoff victory over the Boston Bruins, helped instill a winning attitude in the organization, and mentored a still relatively inexperienced Dominik Hašek. Fuhr then had a successful 1993–94 season with the Sabres, initially sharing goaltending duties with Hašek. Hašek became the Sabres' full time starting goaltender after Fuhr suffered multiple injuries. Fuhr and Hašek were awarded the William M. Jennings Trophy for the fewest goals allowed.


title: Grant Fuhr

text: In May 1993, while a member of the Sabres, Fuhr was denied membership in the neighbouring Transit Valley Country Club. At the time, rumours floated that the denial was based on race, as several of Fuhr's white teammates had been granted membership. Club officials denied they rejected Fuhr based on his race; rather, his application contained "incorrect and incomplete" information. Various acts of vandalism at the club occurred after news of Fuhr's rejection surfaced, including an incident where vandals burned a swastika onto one of the greens. In light of the negative publicity, the club reversed its position and offered Fuhr not only a membership, but an apology as well. Fuhr rejected the membership and joined nearby Lancaster Country Club. The club also temporarily suspended its membership committee and had an anti-bias policy written into its by-laws.


title: Grant Fuhr

text: With Hasek now ensconced in the Sabres' net, Fuhr was dealt to the Los Angeles Kings, on February 14, 1995, reuniting him with Gretzky. Although he began the season out of shape and was considered to be past his prime, his career saw a resurgence when he signed as a free agent with the St. Louis Blues on July 14, 1995, before the 1995–96 campaign. He played 79 games that season, 76 consecutively, both NHL records. On November 30, 1995, Fuhr earned his 300th career win versus the Winnipeg Jets. Fuhr and Gretzky became teammates for the third time when the Blues acquired Gretzky in a trade with the Kings on February 27, 1996. The 1996 playoff run for Fuhr ended prematurely as Maple Leafs forward Nick Kypreos ran into him in the crease in the first round, causing him to tear several knee ligaments. Jon Casey had to play the rest of the playoffs. The Blues beat Toronto in the first round, but lost to Detroit in the next. Even though over the next three years he became one of the three winningest goaltenders in Blues history (along with Mike Liut and Curtis Joseph), Fuhr never fully recovered from his injury. After the Blues signed Roman Turek as their new number one goaltender in 1999, Fuhr was traded to the Calgary Flames on September 5, 1999. He spent one season there being a mentor for Calgary's young goalies, including Fred Brathwaite, and on October 22, 1999, he earned his 400th career win against the Florida Panthers. He announced his retirement on September 6, 2000.


title: Grant Fuhr

text: Fuhr was named to the 1984 Canada Cup team but saw limited action during the tournament due to an injury. Fuhr was again selected to represent Canada for the 1987 Canada Cup. It was here that he cemented his reputation as one of the best goaltenders in the game. Playing against a tough Soviet Union squad, Fuhr turned away shot after shot during the three-game final. He also played for Canada at the 1989 World Championships where he won a silver medal.


title: Grant Fuhr

text: Fuhr was hired to be the Phoenix Coyotes goaltending coach on July 22, 2004. Fuhr held the position until the end of the 2008-09 season, when he was replaced by Sean Burke. He held a similar post with the Calgary Flames in the 2000–2001 and 2001–2002 seasons.


title: Grant Fuhr

text: In 2015, Fuhr collaborated on his biography with Bruce Dowbiggin, "Grant Fuhr: The Story of a Hockey Legend".


title: Grant Fuhr

text: Fuhr was married to Lisa Cavanaugh in the Grand Cayman Islands on September 14, 2014. He has four children from previous marriages and a step-daughter.


title: Grant Fuhr

text: Fuhr was a regular competitor at the American Century Championship, an annual competition to determine the best golfers among American sports and entertainment celebrities. The tournament is played at Edgewood Tahoe Golf Course along the edge of Lake Tahoe.


title: Grant Fuhr

text: Wayne Gretzky has said on many occasions that he believes Fuhr is the greatest goaltender in NHL history. This is mentioned in an interview with Wayne Gretzky conducted by John Davidson as part of the 2003 DVD "Ultimate Gretzky".


title: Locality-sensitive hashing

text: In computer science, locality-sensitive hashing (LSH) is an algorithmic technique that hashes similar input items into the same "buckets" with high probability. (The number of buckets is much smaller than the universe of possible input items.) Since similar items end up in the same buckets, this technique can be used for data clustering and nearest neighbor search. It differs from conventional hashing techniques in that hash collisions are maximized, not minimized. Alternatively, the technique can be seen as a way to reduce the dimensionality of high-dimensional data; high-dimensional input items can be reduced to low-dimensional versions while preserving relative distances between items.


title: Locality-sensitive hashing

text: Hashing-based approximate nearest neighbor search algorithms generally use one of two main categories of hashing methods: either data-independent methods, such as locality-sensitive hashing (LSH); or data-dependent methods, such as locality-preserving hashing (LPH).


title: Locality-sensitive hashing

text: This family formula_1 is a set of functions formula_8 that map elements of the metric space to buckets formula_9. An LSH family must satisfy the following conditions for any two points formula_10 and any hash function formula_11 chosen uniformly at random from formula_1:


title: Locality-sensitive hashing

text: Alternatively it is defined with respect to a universe of items that have a similarity function formula_22. An LSH scheme is a family of hash functions coupled with a probability distribution over the functions such that a function formula_23 chosen according to satisfies the property that formula_24 for any formula_25.


title: Locality-sensitive hashing

text: A locality-preserving hash is a hash function that maps points in a metric space formula_2 to a scalar value such that


title: Locality-sensitive hashing

text: In other words, these are hash functions where the relative distance between the input values is preserved in the relative distance between the output hash values; input values that are closer to each other will produce output hash values that are closer to each other.


title: Locality-sensitive hashing

text: This is in contrast to cryptographic hash functions and checksums, which are designed to have random output difference between adjacent inputs.


title: Locality-sensitive hashing

text: The first family of locality-preserving hash functions was devised as a way to facilitate data pipelining in implementations of parallel random-access machine (PRAM) algorithms that use universal hashing to reduce memory contention and network congestion.


title: Locality-sensitive hashing

text: Given a formula_29-sensitive family formula_1, we can construct new families formula_31 by either the AND-construction or OR-construction of formula_1.


title: Locality-sensitive hashing

text: To create an AND-construction, we define a new family formula_31 of hash functions , where each function is constructed from random functions formula_34 from formula_1. We then say that for a hash function formula_36, formula_37 if and only if all formula_38 for formula_39. Since the members of formula_1 are independently chosen for any formula_36, formula_31 is a formula_43-sensitive family.


title: Locality-sensitive hashing

text: To create an OR-construction, we define a new family formula_31 of hash functions , where each function is constructed from random functions formula_34 from formula_1. We then say that for a hash function formula_36, formula_37 if and only if formula_38 for one or more values of . Since the members of formula_1 are independently chosen for any formula_36, formula_31 is a formula_53-sensitive family.


title: Locality-sensitive hashing

text: One of the easiest ways to construct an LSH family is by bit sampling. This approach works for the Hamming distance over -dimensional vectors formula_54. Here, the family formula_1 of hash functions is simply the family of all the projections of points on one of the formula_56 coordinates, i.e., formula_57, where formula_58 is the formula_59th coordinate of formula_60. A random function formula_11 from formula_62 simply selects a random bit from the input point. This family has the following parameters: formula_63, formula_64.


title: Locality-sensitive hashing

text: Suppose is composed of subsets of some ground set of enumerable items and the similarity function of interest is the Jaccard index . If is a permutation on the indices of , for formula_65 let formula_66. Each possible choice of defines a single hash function mapping input sets to elements of .


title: Locality-sensitive hashing

text: Define the function family to be the set of all such functions and let be the uniform distribution. Given two sets formula_67 the event that formula_68 corresponds exactly to the event that the minimizer of over formula_69 lies inside formula_70. As was chosen uniformly at random, formula_71 and formula_72 define an LSH scheme for the Jaccard index.


title: Locality-sensitive hashing

text: Because the symmetric group on elements has size !, choosing a truly random permutation from the full symmetric group is infeasible for even moderately sized . Because of this fact, there has been significant work on finding a family of permutations that is "min-wise independent" — a permutation family for which each element of the domain has equal probability of being the minimum under a randomly chosen . It has been established that a min-wise independent family of permutations is at least of size formula_73, and that this bound is tight.


title: Locality-sensitive hashing

text: Because min-wise independent families are too big for practical applications, two variant notions of min-wise independence are introduced: restricted min-wise independent permutations families, and approximate min-wise independent families.


title: Locality-sensitive hashing

text: Restricted min-wise independence is the min-wise independence property restricted to certain sets of cardinality at most .


title: Locality-sensitive hashing

text: Nilsimsa is a locality-sensitive hashing algorithm used in anti-spam efforts. The goal of Nilsimsa is to generate a hash digest of an email message such that the digests of two similar messages are similar to each other. The paper suggests that the Nilsimsa satisfies three requirements:


title: Locality-sensitive hashing

text: TLSH is locality-sensitive hashing algorithm designed for a range of security and digital forensic applications. The goal of TLSH is to generate hash digests for messages such that low distances between digests indicate that their corresponding messages are likely to be similar.


title: Locality-sensitive hashing

text: Testing performed in the paper on a range of file types identified the Nilsimsa hash as having a significantly higher false positive rate when compared to other similarity digest schemes such as TLSH, Ssdeep and Sdhash.


title: Locality-sensitive hashing

text: The random projection method of LSH due to Moses Charikar called SimHash (also sometimes called arccos) is designed to approximate the cosine distance between vectors. The basic idea of this technique is to choose a random hyperplane (defined by a normal unit vector ) at the outset and use the hyperplane to hash input vectors.


title: Locality-sensitive hashing

text: Given an input vector and a hyperplane defined by , we let formula_74. That is, formula_75 depending on which side of the hyperplane lies.


title: Locality-sensitive hashing

text: Each possible choice of defines a single function. Let be the set of all such functions and let be the uniform distribution once again. It is not difficult to prove that, for two vectors formula_76, formula_77, where formula_78 is the angle between and . formula_79 is closely related to formula_80.


title: Locality-sensitive hashing

text: In this instance hashing produces only a single bit. Two vectors' bits match with probability proportional to the cosine of the angle between them.


title: Locality-sensitive hashing

text: In particular k-means hash functions are better in practice than projection-based hash functions, but without any theoretical guarantee.


title: Locality-sensitive hashing

text: Semantic hashing is a technique that attempts to map input items to addresses such that closer inputs have higher semantic similarity. The hashcodes are found via training of an artificial neural network or graphical model.


title: Locality-sensitive hashing

text: One of the main applications of LSH is to provide a method for efficient approximate nearest neighbor search algorithms. Consider an LSH family formula_1. The algorithm has two main parameters: the width parameter and the number of hash tables .


title: Locality-sensitive hashing

text: In the first step, we define a new family formula_31 of hash functions , where each function is obtained by concatenating functions formula_34 from formula_1, i.e., formula_94. In other words, a random hash function is obtained by concatenating randomly chosen hash functions from formula_1. The algorithm then constructs hash tables, each corresponding to a different randomly chosen hash function .


title: Locality-sensitive hashing

text: In the preprocessing step we hash all -dimensional points from the data set into each of the hash tables. Given that the resulting hash tables have only non-zero entries, one can reduce the amount of memory used per each hash table to formula_96 using standard hash functions.


title: Locality-sensitive hashing

text: Given a query point , the algorithm iterates over the hash functions . For each considered, it retrieves the data points that are hashed into the same bucket as . The process is stopped as soon as a point within distance formula_97 from is found.


title: Locality-sensitive hashing

text: For a fixed approximation ratio formula_104 and probabilities formula_5 and formula_6, one can set formula_107 and formula_108, where formula_109. Then one obtains the following performance guarantees:


title: Locality-sensitive hashing

text: This happens for example with Jaccard similarity data, where even the most similar neighbor often has a quite low Jaccard similarity with the query.


title: Locality-sensitive hashing

text: In it was shown how to reduce the query time to formula_117 (not including hashing costs) and similarly the space usage.


King Abdullah University of Science and Technology (KAUST; "") is a private research university located in Thuwal, Saudi Arabia. Founded in 2009, the university provides research and graduate training programs in English as the official language of instruction.


title: King Abdullah University of Science and Technology

text: KAUST is the first mixed-gender university campus in Saudi Arabia. In 2013, the university was among the 500 fastest growing research and citation records in the world. In the 2016 Nature Index Rising Stars, the university ranked 19th in the world of the fastest rising universities for high quality research output. In 2019 KAUST is ranked 8th fastest rising young universities (aged 50 and under) for their research output since 2015, as measured by fractional count (FC).


text: In 2006, Ali Al-Naimi chaired a Saudi Aramco team to undertake the building and planning of the academics. Nadhmi Al-Nasr was chosen to lead the project. They employed the Washington Advisory Group's Frank H. T. Rhodes and Frank Press to design the academic structure, SRI International to develop the four research institutes, and the architectural firm of HOK for the campus master plan, which included wind towers and solar panels. The location of the campus at Thuwal included 16.4 sq km on land and 19.6 sq km of marine sanctuary offshore. Ground breaking took place in Oct. 2007, and 178 scholarships were awarded in Jan. 2008.


text: KAUST officially opened on September 23, 2009 at an inauguration ceremony, where King Abdullah Bin Abdulaziz Al Saud gave a speech where he stated that places like the University that "embrace all people are the first line of defence against extremists". The University initially received a $10 billion endowment. Upon opening, the University admitted 400 students from over 60 countries and 70 faculty. The campus is home to Shaheen, Asia's fastest supercomputer at the time of its commissioning.


text: The University's core campus, located on the Red Sea at Thuwal, is sited on more than , encompassing a marine sanctuary, museum, and research facility.


text: KAUST is the first mixed-gender university campus in Saudi Arabia. Saudi authorities hope the mixed-gender center will help modernize the Kingdom's deeply conservative society. The religious police do not operate on-site. Women are allowed to mix freely with men and they are not required to wear veils in the coeducational classes.


text: KAUST was Saudi Arabia's first LEED certified project and is the world's largest LEED Platinum campus. Designed by international architecture firm Hellmuth, Obata and Kassabaum, it was also chosen by the American Institute of Architects (AIA) Committee on the Environment (COTE) as one of the 2010 Top Ten Green Projects. The university library received the 2011 AIA/ALA Library Building Award for accomplishments in library architecture.


text: KAUST organizes its research teams across three academic disciplines, 12 research centers and individual faculty labs. KAUST focuses its research around the areas of food and health, water, energy, environment and the digital domain.


text: Research in the Biological and Environmental Science and Engineering Division (BESE) is organized around six focal areas: environmental systems; epigenetics; functional biology; genomics; imaging/structural biology; and marine science.


text: Research in the Computer, Electrical and Mathematical Sciences and Engineering Division (CEMSE) is clustered into four main areas:


text: Research in the Physical Sciences and Engineering Division (PSE) includes areas such as theoretical physics and physical chemistry; catalysis and bioengineering; polymers and composites; energy production, storage and conversion; water purification and environmental protection; novel materials, nanodevices and systems; sensors and smart devices for the detection of pollutants and the purification of air, water, and food; earth sciences, mechanics and geomechanics; oil exploration and recovery; and CO2 sequestration.


text: The Master of Science (M.S.) program at KAUST can be taken in one of the 16 available disciplines. It is expected that students complete the degree in 18 months and may be completed with or without a thesis component.


text: Admission to the M.S. program requires the satisfactory completion of an undergraduate science degree in a relevant or related area, such as engineering, mathematics or the physical, chemical and biological sciences.


text: The Doctor of Philosophy (Ph.D.) program at KAUST can be taken in one of the 16 available disciplines. It typically takes three to four years to complete.


text: Admission to the Ph.D. program requires the satisfactory completion of a master's degree in science in a relevant or related area, such as engineering, mathematics or the physical, chemical and biological sciences.


text: The M.S./Ph.D. program allows students to apply for the Ph.D. program after completing a bachelor’s degree. The program typically takes four to five years to complete.


text: KAUST offers a one year Postgraduate Diploma in Digital Industrial Design, Physical Science and Engineering, and Bioscience. Each program is made up of soft skill, experimental, theoretical and entrepreneurship courses as well as a capstone experience.


text: The VSRP is a three to six month internship program available for 3rd/4th year undergraduate or master's students. During the program, students will work under the guidance of KAUST faculty mentors on a current research project. Students accepted into the program receive a monthly stiped as well as having their accommodation, health insurance and travel costs covered.


text: The Visiting Student Program (VS) is a flexible program allowing 3rd/4th year undergraduate or master's students to work directly with KAUST faculty members. Its length can range from a few days to several months. Students accepted into the program normally receive a monthly stiped as well as having their accommodation, health insurance and travel costs covered.


text: While there is no minimum academic entry requirement, those admitted typically have strong grade profiles and clear research interests. Applicants are also required to meet English language requirements for entry unless they qualify for an exemption.


text: Every student who is admitted receives the KAUST Fellowship. This fellowship covers the cost of a student’s tuition fees, accommodation, health insurance, and relocation costs as well as giving the student a monthly stiped.


title: Piero della Francesca

text: Piero della Francesca (, , ; – 12 October 1492), originally named Piero di Benedetto, was an Italian painter of the Early Renaissance. To contemporaries he was also known as a mathematician and geometer. Nowadays Piero della Francesca is chiefly appreciated for his art. His painting is characterized by its serene humanism, its use of geometric forms and perspective. His most famous work is the cycle of frescoes "The History of the True Cross" in the church of San Francesco in the Tuscan town of Arezzo.


title: Piero della Francesca

text: Piero was born Piero di Benedetto in the town of Borgo Santo Sepolcro, modern-day Tuscany, to Benedetto de' Franceschi, a tradesman, and Romana di Perino da Monterchi, members of the Florentine and Tuscan Franceschi noble family. His father died before his birth, and he was called Piero della Francesca after his mother, who was referred to as "la Francesca" due to her marriage into the Franceschi family (similar to how Lisa Gherardini became known as "la Gioconda" through her marriage into the Giocondo family). Romana supported his education in mathematics and art.


title: Piero della Francesca

text: He was most probably apprenticed to the local painter Antonio di Giovanni d'Anghiari, because in documents about payments it is noted that he was working with Antonio in 1432 and May 1438. He certainly took notice of the work of some of the Sienese artists active in San Sepolcro during his youth; e.g. Sassetta. In 1439 Piero received, together with Domenico Veneziano, payments for his work on frescoes for the church of Sant'Egidio in Florence, now lost. In Florence he must have met leading masters like Fra Angelico, Luca della Robbia, Donatello, and Brunelleschi. The classicism of Masaccio's frescoes and his majestic figures in the Santa Maria del Carmine were for him an important source of inspiration. Dating of Piero's undocumented work is difficult because his style does not seem to have developed over the years.


title: Piero della Francesca

text: Piero returned to his hometown in 1442 and was elected to the City Council of Sansepolcro. Three years later, he received his first commission, to paint the "Madonna della Misericordia" altarpiece for the church of the Misericordia in Sansepolcro, which was completed in the early 1460s. In 1449 he executed several frescoes in the Castello Estense and the church of Sant'Andrea of Ferrara, now also lost. His influence was particularly strong in the later Ferrarese allegorical works of Cosimo Tura.


title: Piero della Francesca

text: The "Baptism of Christ", now in the National Gallery in London, was completed in about 1450 for the high altar of the church of the Priory of S. Giovanni Battista at Sansepolcro. Other notable works are the frescoes of "The Resurrection" in Sansepolcro, and the "Madonna del parto" in Monterchi, near Sansepolcro.


title: Piero della Francesca

text: Two years later he was in Rimini, working for the condottiero Sigismondo Pandolfo Malatesta. In 1451, during that sojourn, he executed the famous fresco of "St. Sigismund and Sigismondo Pandolfo Malatesta" in the Tempio Malatestiano, as well as a portrait of Sigismondo. In Rimini, Piero may have met the famous Renaissance mathematician and architect Leon Battista Alberti, who had redesigned the Tempio Malatestiano, although it is known that Alberti directed the execution of his designs for the church by correspondence with his building supervisor. Thereafter Piero was active in Ancona, Pesaro and Bologna.


title: Piero della Francesca

text: In 1454, he signed a contract for the "Polyptych of Saint Augustine" in the church of Sant'Agostino in Sansepolcro. The central panel of this polyptych is lost, and the four panels of the wings, with representations of saints, are now scattered around the world. A few years later, summoned by Pope Nicholas V, he moved to Rome, where he executed frescoes in the Basilica di Santa Maria Maggiore, of which only fragments remain. Two years later he was again in the Papal capital, painting frescoes in the Vatican Palace, which have since been destroyed.


title: Piero della Francesca

text: In 1452, Piero della Francesca was called to Arezzo to replace Bicci di Lorenzo in painting the frescoes of the basilica of San Francesco. The work was finished in 1464.


title: Piero della Francesca

text: "The History of the True Cross" cycle of frescoes is generally considered among his masterworks and those of Renaissance painting in general. The story in these frescoes derives from legendary medieval sources as to how timber relics of the True Cross came to be found. These stories were collected in the "Golden Legend" of Jacopo da Varazze (Jacopo da Varagine) of the mid-13th century.


title: Piero della Francesca

text: At some point, Giovanni Santi invited Piero to Urbino. Between 1469 and 1486 Piero worked repeatedly in the service of Count Federico III da Montefeltro (Duke in 1474). "The Flagellation" is generally considered Piero's oldest work in Urbino (c. 1455–1470). It is one of the most famous and controversial pictures of the early Renaissance. As discussed in its own entry, it is marked by an air of geometric sobriety, in addition to presenting a perplexing enigma as to the nature of the three men standing at the foreground.


title: Piero della Francesca

text: Another famous work painted in Urbino is the "Double Portrait" of Federico and his wife Battista Sforza, in the Uffizi. The portraits in profile take their inspiration from large bronze medals and stucco roundels with the official portraits of Fedederico and his wife. Other paintings made in Urbino are the monumental Montefeltro Altarpiece (1474) in the Brera Gallery in Milan and the "Madonna of Senigallia".


title: Piero della Francesca

text: In Urbino Piero met the painters Melozzo da Forlì, Fra Carnevale, and the Flemish Justus van Gent, the mathematician Fra Luca Pacioli, the architect Francesco di Giorgio Martini, and probably also Leon Battista Alberti.


title: Piero della Francesca

text: In his later years, painters such as Perugino and Luca Signorelli frequently visited his workshop. He completed the treatise "On Perspective in Painting" in the mid-1470s to 1480s. By 1480, his vision began to deteriorate, but he continued writing treatises such as "Short Book on the Five Regular Solids" in 1485. It is documented that Piero rented a house in Rimini in 1482. Piero made his will in 1487 and he died five years later, on 12 October 1492, in his own house in San Sepolcro. He left his possessions to his family and the church.


title: Piero della Francesca

text: Recently, the Frick Collection in New York until 19 May 2013, collected seven of the eight extant paintings of Piero known to exist in the United States for exhibition. Of the seven pieces in the exhibit, critic Jerry Saltz writing in "New York" magazine singled out Piero's "Virgin and Child Enthroned With Four Angels" for its exemplary qualities.


title: Piero della Francesca

text: Saltz states that, "The Virgin and child are elevated two steps. They are in a world itself apart from this world apart. Mary isn't looking at her child and looks instead at the rose he reaches for. You begin to glean the revelation she is having. The flower represents love, devotion, and beauty. It also symbolizes blood and the crown of thorns Christ will wear. This child who will suffer a horrendous death reaches for his acceptance of fate. Mary does not pull the flower back. You sense an inner agony, noticing her deep-blue robe open to reveal scarlet beneath, symbol of outward passion and pain to come. In the dead-center vertical line of the painting is Christ's right palm that will be nailed to the cross."


title: Piero della Francesca

text: Piero's deep interest in the theoretical study of perspective and his contemplative approach to his paintings are apparent in all his work.


title: Piero della Francesca

text: In his youth, Piero was trained in mathematics, which most likely was for mercantilism. Three treatises written by Piero have survived to the present day: "", "De quinque corporibus regularibus" ("On the Five Regular Solids") and "De Prospectiva pingendi" ("On Perspective in painting"). The subjects covered in these writings include arithmetic, algebra, geometry and innovative work in both solid geometry and perspective. Much of Piero's work was later absorbed into the writing of others, notably Luca Pacioli. Piero's work on solid geometry was translated in Pacioli's "Divina proportione", a work illustrated by Leonardo da Vinci. Biographers of his patron Federico da Montefeltro of Urbino record that he was encouraged to pursue the interest in perspective which was shared by the Duke.