document_title: Valley of the Kings

question_text: map of tombs in valley of the kings

question_tokens: map of tombs in valley of the kings

text: Valley of the Kings

text: Geology[edit]

text: The types of soil where the Valley of the Kings is located are an alternating sandwich of dense limestone and other sedimentary rock (which form the cliffs in the valley and the nearby Deir el-Bahri) and soft layers of marl. The sedimentary rock was originally deposited between 35–56 million years ago during a time when the precursor to the Mediterranean Sea covered an area that extended much further inland than it does today. During the Pleistocene the valley was carved out of the plateau by steady rains.[10] There is currently little year-round rain in this part of Egypt, but there are occasional flash floods that hit the valley, dumping tons of debris into the open tombs.[11]

text: The quality of the rock in the Valley is inconsistent, ranging from finely-grained to coarse stone, the latter with the potential to be structurally unsound. The occasional layer of shale also caused construction and conservation difficulties, as this rock expands in the presence of water, forcing apart the stone surrounding it. It is thought that some tombs were altered in shape and size depending on the types of rock the builders encountered.[10]

text: Builders took advantage of available geological features when constructing the tombs. Some tombs were quarried out of existing limestone clefts, others behind slopes of scree, or were at the edge of rock spurs created by ancient flood channels.[10]

text: The problems of tomb construction can be seen with tombs of Ramesses III and his father Setnakhte. Setnakhte started to excavate KV11 but broke into the tomb of Amenmesse, so construction was abandoned and he instead usurped the tomb of Twosret, KV14. When looking for a tomb, Ramesses III extended the partly-excavated tomb started by his father.[12] The tomb of Ramesses II returned to an early style, with a bent axis, probably due to the quality of the rock being excavated (following the Esna shale).[13]

text: Between 1998 and 2002 the Amarna Royal Tombs Project investigated the valley floor using ground-penetrating radar and found that, below the modern surface, the Valley's cliffs descend beneath the scree in a series of abrupt, natural "shelves", arranged one below the other, descending several metres down to the bedrock in the valley floor.[14]

text: Hydrology[edit]

text: The area of the Theban hills is subject to infrequent violent thunder storms, causing flash floods in the valley. Recent studies have shown that there are at least seven active flood stream beds leading down into the central area of the valley.[15] This central area appears to have been flooded at the end of the Eighteenth Dynasty, with several tombs buried under metres of debris. The tombs KV63, KV62, and KV55 are dug into the actual wadi bedrock rather than the debris, showing that the level of the valley was five meters below its present level.[16] After this event later dynasties leveled the floor of the valley, making the floods deposit their load further down the valley, and the buried tombs were forgotten and only discovered in the early 20th century.[17] This was the area that was the subject of the Amarna Royal Tombs Project ground scanning radar investigation, which showed several anomalies, one of which was proved to be KV63.[18]

text: History[edit]

text: The Theban Hills are dominated by the peak of al-Qurn, known to the Ancient Egyptians as ta dehent, or 'The Peak'.[19] It has a pyramid-shaped appearance, and it is probable that this echoed the pyramids of the Old Kingdom, more than a thousand years prior to the first royal burials carved here.[20][21] Its isolated position also resulted in reduced access, and special tomb police (the Medjay) were able to guard the necropolis.[22]

text: While the iconic pyramid complexes of the Giza plateau have come to symbolize ancient Egypt, the majority of tombs were cut into rock. Most pyramids and mastabas contain sections which are cut into ground level, and there are full rock-cut tombs in Egypt that date back to the Old Kingdom.[23]

text: After the defeat of the Hyksos and the reunification of Egypt under Ahmose I, the Theban rulers began to construct elaborate tombs that reflected their newfound power.[24] The tombs of Ahmose and his son Amenhotep I (their exact location remains unknown) were probably in the Seventeenth Dynasty necropolis of Dra' Abu el-Naga'.[25] The first royal tombs in the valley were those of Amenhotep I (although this identification is also disputed),[26] and Thutmose I, whose advisor, Ineni, notes in his tomb that he advised the king to place his tomb in the desolate valley (the identity of this actual tomb is unclear, but it is probably KV20 or KV38).[19]

text:
“
I saw to the excavation of the rock-tomb of his majesty, alone, no one seeing, no one hearing.[27]
”

text: The Valley was used for primary burials from approximately 1539 BC to 1075 BC. It contains at least 63 tombs, beginning with Thutmose I (or possibly earlier, during the reign of Amenhotep I) and ending with Ramesses X or XI, although non-Royal burials continued in usurped tombs.[28]

text: Despite its name, the Valley of the Kings also contains the tombs of favorite nobles as well as the wives and children of both nobles and pharaohs. Therefore, only about 20 of the tombs actually contain the remains of kings. The remains of nobles and of the royal family, together with unmarked pits and embalming caches, make up the rest.[29] Around the time of Ramesses I (ca. 1301 BC) construction commenced in the separate Valley of the Queens.[30]

text: Royal Necropolis[edit]

text: The official name for the site in ancient times was The Great and Majestic Necropolis of the Millions of Years of the Pharaoh, Life, Strength, Health in The West of Thebes (see below for the hieroglyphic spelling), or Ta-sekhet-ma'at (the Great Field).[31]

text: At the start of the Eighteenth Dynasty, only kings were buried within the valley in large tombs. When a non-royal person was buried, it was in a small rock cut chamber, close to the tomb of their master.[27] Amenhotep III's tomb was constructed in the Western Valley, and while his son Akhenaten moved his tomb's construction to Amarna, it is thought that the unfinished WV25 may have originally been intended for him.[32] With the return to religious orthodoxy at the end of the Eighteenth Dynasty, Tutankhamun, Ay, and Horemheb returned to the royal necropolis.[33]

text: The Nineteenth and Twentieth Dynasties saw an increase in the number of burials (both here and in the Valley of the Queens), with Ramesses II and later Ramesses III constructing a massive tomb that was used for the burial of their sons (KV5 and KV3 respectively).[34][35] There are some kings that are not buried within the valley or whose tomb has not been located: Thutmose II may have been buried in Dra' Abu el-Naga' (although his mummy was in the Deir el-Bahri tomb cache),[36] Smenkhkare's burial has never been located, and Ramesses VIII seems to have been buried elsewhere.

text: In the Pyramid Age, the tomb of the king was associated with a mortuary temple located close to the pyramid. As the tomb of the king was hidden, this mortuary temple was located away from the burial, closer to the cultivation facing toward Thebes.[19] These mortuary temples became places visited during the various festivals held in the Theban necropolis. Most notable is the Beautiful festival of the valley, where the sacred barques of Amun-Re, his consort, Mut, and son, Khonsu, left the temple at Karnak in order to visit the funerary temples of deceased kings on the West Bank and their shrines in the Theban Necropolis.[37]

text: The tombs were constructed and decorated by the workers of the village of Deir el-Medina, located in a small wadi between this valley and the Valley of the Queens, facing Thebes. The workers journeyed to the tombs through various routes over the Theban hills. The daily lives of these workers are quite well known and are recorded in tombs and official documents.[38] Amongst the events documented is perhaps the first recorded worker's strike, detailed in the Turin strike papyrus.[39][40]

text: Exploration of the valley[edit]

text: The area has been a major focus of modern Egyptological exploration for the last two centuries. Prior to this time it was a site for tourism in antiquity (especially during Roman times).[28] This area illustrates the changes in the study of ancient Egypt, starting as antiquity hunting, and ending as scientific excavation of the whole Theban Necropolis. Despite the exploration and investigation noted below, only eleven of the tombs have actually been completely recorded.

text: Many of the tombs have graffiti written by these ancient tourists. Jules Baillet has located over 2,100 Greek and Latin instances of graffiti, along with a smaller number in Phoenician, Cypriot, Lycian, Coptic, and other languages.[28] The majority of the ancient graffiti is found in KV9, which contains just under a thousand of them. The earliest positively dated graffiti dates to 278 B.C.[41]

text: In 1799, members of Napoleon's expedition to Egypt (especially Dominique Vivant) drew maps and plans of the known tombs, and for the first time noted the Western Valley (where Prosper Jollois and Édouard de Villiers du Terrage located the tomb of Amenhotep III, WV22).[42] The Description de l'Égypte contains two volumes (out of a total of 24) on the area around Thebes.[43]

text: European exploration continued in the area around Thebes during the nineteenth century, boosted by Champollion's translation of hieroglyphs. Early in the century, the area was visited by Belzoni, working for Henry Salt, who discovered several tombs, including those of Ay in the West Valley (WV23) in 1816 and Seti I (KV17) the following year. At the end of his visits, Belzoni declared that all of the tombs had been located and nothing of note remained to be found. Working at the same time (and a great rival of Belzoni and Salt) was Bernardino Drovetti, the French Consul-General.[44]

text: When Gaston Maspero was reappointed as head of the Egyptian Antiquities Service, the nature of the exploration of the valley changed again. Maspero appointed English archaeologist Howard Carter as the Chief Inspector of Upper Egypt, and the young man discovered several new tombs and explored several others, clearing KV42 and KV20.[45]

text: Around the start of the 20th century American explorer Theodore M. Davis had the excavation permit in this valley. His team (led mostly by Edward R. Ayrton) discovered several royal and non-royal tombs (including KV43, KV46 and KV57). In 1907 they discovered the possible Amarna Period cache in KV55. After finding what they thought was all that remained of the burial of Tutankhamun (items recovered from KV54 and KV58), it was announced that the valley was completely explored and that no further burials were to be found. Davis's 1912 publication, The Tombs of Harmhabi and Touatânkhamanou closes with the comment, "I fear that the Valley of Kings is now exhausted."[46]

text: After Davis's death early in 1915, Lord Carnarvon acquired the concession to excavate the valley, and he employed Howard Carter to explore it. After a systematic search, they discovered the actual tomb of Tutankhamun (KV62) in November 1922.[47]

text: Various expeditions have continued to explore the valley, adding greatly to the knowledge of the area. In 2001 the Theban Mapping Project designed new signs for the tombs, providing information and plans of the open tombs.[48]

text: Tomb development[edit]

text: A map of the Valley of the Kings with locations of tombs marked

text: The earliest tombs were located in cliffs at the top of scree slopes, under storm-fed waterfalls (KV34 and KV43).[19] As these locations were filled, burials descended to the valley floor, gradually moving back up the slopes as the valley bottom filled with debris. This explains the location of the tombs KV62 and KV63 buried in the valley floor.

text: The usual tomb plan consisted of a long inclined rock-cut corridor, descending through one or more halls (possibly mirroring the descending path of the sun god into the underworld[49]) to the burial chamber. In the earlier tombs, the corridors turn 90 degrees at least once (such as KV43, the tomb of Thutmose IV), and the earliest ones had cartouche-shaped burial chambers (for example, KV43, the tomb of Thutmose IV).[50] This layout is known as 'Bent Axis',[51] After the burial the upper corridors were meant to be filled with rubble and the entrance to the tomb hidden.[52] After the Amarna Period, the layout gradually straightened, with an intermediate 'Jogged Axis' (the tomb of Horemheb, KV57 is typical of this and is one of the tombs that is sometimes open to the public), to the generally 'Straight Axis' of the late Nineteenth and Twentieth Dynasty tombs (Ramesses III's and Ramesses IX's tombs, KV11 and KV6 respectively).[53] As the tombs' axes straightened, the slopes also lessened. They almost disappeared in the late Twentieth Dynasty.[54] Another feature that is common to most tombs is the 'well', which may have originated as an actual barrier intended to stop flood waters from entering the lower parts of the tomb. It seems to have developed a 'magical' purpose later on as a symbolic shaft.[50] In the later Twentieth Dynasty, the well itself was sometimes not excavated, but the well room was still present.[50][55]

text: The majority of the royal tombs were decorated with religious texts and images. The early tombs were decorated with scenes from Amduat ('That Which is in the Underworld'), which describes the journey of the sun god through the twelve hours of the night. From the time of Horemheb, tombs were decorated with the Book of Gates, which shows the sun god passing through the twelve gates that divide the nighttime and ensures the tomb owner's own safe passage through the night.[56] These earliest tombs were generally sparsely decorated, and those of a non-royal nature were totally undecorated.

text: Late in the Nineteenth Dynasty the Book of Caverns, which divided the underworld into massive caverns containing deities as well as the deceased waiting for the sun to pass through and restore them to life, was placed in the upper parts of tombs. A complete version appears in the tomb of Ramesses VI.[56] The burial of Ramesses III saw the Book of the Earth, where the underworld is divided into four sections, climaxing in the sun disc being pulled from the earth by Naunet.[57]

text: The ceilings of the burial chambers were decorated (from the burial of Seti I onwards) with what became formalised as the Book of the Heavens, which again describes the sun's journey through the twelve hours of night. Again from Seti I's time, the Litany of Re, a lengthy hymn to the sun god began to appear.[56]

text: Each burial was provided with equipment that would enable a comfortable existence in the afterlife. Also present in the tombs were items used to perform magic rituals, such as Shabtis and divine figurines. Some equipment was what the king may have used during his lifetime (Tutankhamun's sandals for example), and some was specially constructed for the burial.[58]

text: Tomb numbering[edit]

text: The modern abbreviation "KV" stands for "Kings' Valley", and the tombs are numbered according to their order of 'discovery', from KV1 (Rameses VII) to KV64 (discovered in 2012). Since the early 19th century AD, antiquarians and archaeologists have cleared and recorded tombs, with a total of 61 sepulchers being known by the start of the 20th century.[59] KV5 was only rediscovered in the 1990s after being dismissed as unimportant by previous investigators.[58] The West Valley tombs often carry the prefix "WV", but they follow the same numbering system. Some of the tombs are unoccupied, others remain unidentifiable as regards to their owners, and still others are merely pits used for storage.[59] Most of the open tombs in the Valley of the Kings are located in the East Valley, and this is where most of the tourist facilities are located.

text: Eighteenth Dynasty[edit]

text: The Eighteenth Dynasty tombs within the valley vary quite a bit in decoration, style, and location. It seems that at first there was no fixed plan. The tomb of Hatshepsut has a unique shape, twisting and turning down over 200 metres from the entrance, so that the burial chamber is 97 metres below the surface. The tombs gradually became more regular and formalised, and those of Thutmose III and Thutmose IV, KV34 and KV43, are good examples of Eighteenth Dynasty tombs, both with their bent axis, and simple decoration.[60]

text: Perhaps the most imposing tomb of this period is that of Amenhotep III, WV22, located in the West Valley.[61] It was re-investigated in the 1990s by a team from Waseda University, Japan, but it is not open to the public.[62]

text: At the same time, powerful and influential nobles began to be buried with the royal family; the most famous of these tombs is the joint tomb of Yuya and Tjuyu, KV46. They were possibly the parents of Queen Tiy. Until the discovery of the tomb of Tutankhamun, this was the best-preserved of the tombs that had been discovered in the Valley.[63]

text: Amarna Period[edit]

text: The return of royal burials to Thebes after the end of the Amarna period marks a change to the layout of royal burials, with the intermediate 'jogged axis' gradually giving way to the 'straight axis' of later dynasties. In the Western Valley, there is a tomb commencement that is thought to have been started for Akhenaten, but it is no more than a gateway and a series of steps. The tomb of Ay, Tutankhamun's successor is close by. It is likely that this tomb was started for Tutankhamun (its decoration is of a similar style) but later usurped for Ay's burial. This would mean that KV62 may have been Ay's original tomb, which would explain the smaller size and unusual layout for a royal tomb.[64]

text: The other Amarna period tombs are located in a smaller, central area in the centre of the East Valley, with a possible mummy cache (KV55) that may contain the burials of several Amarna Period royals—Tiy and Smenkhkare or Akhenaten.[65]

text: In close proximity is the burial of Tutankhamun. This is perhaps the most famous discovery of modern Western archaeology. It was discovered here by Howard Carter on November 4, 1922, with clearance and conservation work continuing until 1932. This was the first royal tomb to be discovered that was still largely intact, although tomb robbers had entered. And until the excavation of KV63 on 10 March 2005,[66] it considered the last major discovery in the valley. The opulence of his grave goods notwithstanding, Tutankhamun was a relatively minor king, and other burials probably had more numerous treasures.[67]

text: In the same central area as KV62 and KV63, is KV64,a radar anomaly believed to be a tomb or chamber announced on 28 July 2006. It is not an official designation, and the actual existence of a tomb at all is dismissed by the Supreme Council of Antiquities.[68]

text: The nearby tomb of Horemheb, (KV57) is rarely open to visitors. But it has many unique features and is extensively decorated. The decoration shows a transition from the pre-Amarna tombs to those of the 19th dynasty tombs that followed.[69]

text: Nineteenth Dynasty[edit]

text: The Nineteenth Dynasty saw a further standardisation of tomb layout and decoration. The tomb of the first king of the dynasty, Ramesses I, was hurriedly finished due to the death of the king and is little more than a truncated descending corridor and a burial chamber. However, KV16 has vibrant decoration and still contains the sarcophagus of the king. Its central location makes it one of the more frequently visited tombs. It shows the development of the tomb entrance and passage and of decoration.[70]

text: His son and successor, Seti I's tomb, KV17 (also known as Belzoni's tomb, the tomb of Apis, or the tomb of Psammis, son of Necho), is usually regarded as the finest tomb in the valley. It has extensive relief work and paintings. When it was rediscovered by Belzoni in 1817, he referred to it as "..a fortunate day.."[71]

text: The son of Seti, Ramesses the Great, constructed a massive tomb, KV7, but it is in a ruinous state. It is currently undergoing excavation and conservation by a Franco-Egyptian team led by Christian Leblanc.[72][73] The tomb is vast in size, about the same length, and a larger area, of the tomb of his father.

text: At the same time, and just opposite his own tomb, Ramesses enlarged the earlier small tomb of an unknown Eighteenth Dynasty noble (KV5) for his numerous sons. With 120 known rooms, and excavation work still underway, it is probably the largest tomb in the valley. Originally opened (and robbed) in antiquity, it is a low-lying structure that has been particularly prone to the flash floods that sometimes hit the area. Tonnes of debris and material has washed in over the centuries, ultimately concealing its vast size. It is not currently open to the public.[74]

text: Ramesses II's son and eventual successor, Merenptah's tomb has been open since antiquity; it extends 160 metres, ending in a burial chamber that once contained a set of four nested sarcophagi.[75] Well decorated, it is typically open to the public most years.[76]

text: The last kings of the dynasty also constructed tombs in the valley, all of which follow the same general pattern of layout and decoration. Notable amongst these is the tomb of Siptah, which is well decorated, especially the ceiling.[77]

text: Twentieth Dynasty[edit]

text: The first ruler of the dynasty, Setnakhte, actually had two tombs constructed for himself. He started excavating the eventual tomb of his son, Ramesses III, but broke into another tomb and abandoned it in order to usurp and complete the tomb of the Nineteenth Dynasty female pharaoh, Twosret. Therefore, this tomb has two burial chambers, the later extensions making the tomb one of the largest of the Royal tombs, at over 150 metres.[78]

text: The tomb of Ramesses III (known as Bruce's Tomb or The Harper's Tomb due to its decoration) is one of the largest tombs in the valley and is open to the public. It is located close to the central 'rest–area', and its location and superb decoration make this one of the tombs most visited by tourists.[79]

text: The successors and offspring of Ramesses III constructed tombs that had straight axes. They all had similar decorations. Notable amongst these is KV2, the tomb of Ramesses IV, which has been open since antiquity, containing a large amount of hieratic graffiti. The tomb is mostly intact and is decorated with scenes from several religious texts.[80] The joint tomb of Ramesses V and Ramesses VI, KV9 (also known as the Tomb of Memnon or La Tombe de la Métempsychose) is decorated with many sunk-relief carvings, depicting illustrated scenes from religious texts. Open since antiquity, it contains over a thousand examples of graffiti written in ancient Greek, Latin and Coptic.[81] The spoil from the excavation and later clearance of this tomb, together with later construction of workers huts, covered the earlier burial of KV62 and seems to have been what protected that tomb from earlier discovery and looting.[82]

text: The tomb of Ramesses IX, KV6, has been open since antiquity, as can be seen by the graffiti left on its walls by Roman and Coptic visitors.[83] Located in the central part of the valley, it is between and slightly above KV5 and KV55. The tomb extends a total distance of 105 metres into the hillside, including extensive side chambers that were neither decorated nor finished. The hasty and incomplete nature of the rock-cutting and decorations (it is only decorated for a little over half its length) within the tomb indicate that the tomb was not completed by the time of Ramesses' death, with the completed hall of pillars serving as the burial chamber.[84]

text: Another notable tomb from this dynasty is KV19, the tomb of Mentuherkhepshef (son of Ramesses IX). This small tomb is simply a converted, unfinished corridor, but the decoration is extensive. The tomb has been newly restored and opened for visitors.[85][86]

text: Twenty-first Dynasty and the decline of the necropolis[edit]

text: By the end of the New Kingdom, Egypt had entered a long period of political and economic decline. The priests at Thebes grew more powerful, and they effectively administered Upper Egypt, while kings ruling from Tanis controlled Lower Egypt. Some attempt at using the open tombs was made at the start of the Twenty-first Dynasty, with the High Priest of Amun, Pinedjem I, adding his cartouche to KV4.[87] The Valley began to be heavily plundered, so during the Twenty-first Dynasty the priests of Amun opened most of the tombs and moved the mummies into three tombs in order to better protect them. They removed most of the treasure in order to further protect the bodies from robbers. Most of these were later moved to a single cache near Deir el-Bari (known as TT320). Located in the cliffs overlooking Hatshepsut's famous temple, this mass reburial contained a large number of royal mummies.[36][88] They were found in a great state of disorder, many placed in other's coffins, and several are still unidentified. Other mummies were moved to the tomb of Amenhotep II, where over a dozen mummies, many of them royal, were later relocated.[89]

text: During the later Third Intermediate Period and later periods, intrusive burials were introduced into many of the open tombs. In Coptic times, some of the tombs were used as churches, stables, and even houses.[19]

text: Minor tombs in the Valley of the Kings[edit]

text: The majority of the 65 numbered tombs in the Valley of the Kings can be considered as minor tombs, either because at present they have yielded little information or because the results of their investigations were only poorly recorded by their explorers. Some have received very little attention or were only cursorily noted. Most of these tombs are small, often consisting of only a single burial chamber accessed by a shaft or staircase with a corridor or a series of corridors leading to the chamber. But some are larger, multiple-chambered tombs. These minor tombs served various purposes: some were intended for burials of lesser royalty or private burials, some contained animal burials, and others apparently never received a primary burial. In many cases these tombs also served secondary functions, and later intrusive material has been found related to these secondary activities. While some of these tombs have been open since antiquity, the majority were discovered in the 19th and early 20th centuries during the height of exploration in the valley.

text: Tomb robbers[edit]

text: Almost all of the tombs have been ransacked.[90] Several papyri have been found that describe the trials of tomb robbers. These date mostly from the late Twentieth Dynasty. One of these, Papyrus Mayer B, describes the robbery of the tomb of Ramesses VI and was probably written in Year Nine of Ramesses IX:

text: The foreigner Nesamun took us up and showed us the tomb of King Ramesses VI ... And I spent four days breaking into it, we being present all five. We opened the tomb and entered it. ... We found a cauldron of bronze, three wash bowls of bronze ...[91]

text: The valley also seems to have suffered an official plundering during the virtual civil war, which started during the reign of Ramesses XI. The tombs were opened, all the valuables were removed, and the mummies were collected into two large caches. One in the tomb of Amenhotep II, contained sixteen, and others were hidden within Amenhotep I's tomb. A few years later most of them were moved to the Deir el-Bahri cache, containing no fewer than forty royal mummies and their coffins.[92] Only tombs whose locations were lost (KV62, KV63 and KV46, although both KV62 and KV46 were robbed soon after their actual closure[93]) were undisturbed during this period.

text: Tourism[edit]

text: Most of the tombs are not open to the public (18 of the tombs can be opened, but they are rarely open at the same time), and officials occasionally close those that are open for restoration work.[94] The number of visitors to KV62 has led to a separate charge for entry into the tomb. The West Valley has only one open tomb—that of Ay—and a separate ticket is needed to visit this tomb.[48][95] The tour guides are no longer allowed to lecture inside the tombs, and visitors are expected to proceed quietly and in single file through the tombs. This is to minimize time in the tombs and prevent the crowds from damaging the surfaces of the decoration. Photography is no longer allowed in the tombs.[96]

text: In 1997, 58 tourists and four Egyptians were massacred at nearby Deir el-Bahri by Islamist militants from Al-Gama'a al-Islamiyya. This led to an overall drop in tourism in the area.[97]

text: On most days of the week an average of 4,000 to 5,000 tourists visit the main valley. On the days that the Nile Cruises arrive, the number can rise to over 9,000. These levels are expected to rise to 25,000 by 2015.[98] The West Valley is much less visited, as there is only one tomb that is open to the public.[48]


document_title: Antigen-antibody interaction

question_text: when does the antigen affect the valence or number of bonds

root

text: Antigen-antibody interaction

text: Antibody structure[edit]

text: In an antibody, the Fab (fragment, antigen-binding) region is formed from the amino-terminal end of both the light and heavy chains of the immunoglobulin polypeptide. This region called V (variable) domain is composed of amino acid sequences that define each type of antibody and their binding affinity to an antigen. The combined sequence of variable light chain (VL) and variable heavy chain (VH) creates three hypervariable regions (HV1, HV2, and HV3). In VL these are roughly from residues 28 to 35, from 49 to 59, and from 92 to 103, respectively. HV3 is the most variable part. Thus these regions are the paratope, the binding site of antigen. The rest of the V region between the hypervariable regions are called framework regions. Each V domain has four framework domains, namely FR1, FR2, FR3, and FR4.[4][5]

tag: p

text: Properties[edit]

text: Chemical basis of antigen-antibody interaction[edit]

text: Antibodies bind antigens through weak chemical interactions, and bonding is essentially non-covalent. Electrostatic interactions, hydrogen bonds, van der Waals forces, and hydrophobic interactions are all known to be involved depending on the interaction sites.[6][7]

text: Affinity of the interaction[edit]

text: Antigen and antibody interact through a high affinity binding much like lock and key.[8] A dynamic equilibrium exists for the binding. For example, the reaction is a reversible one, and can be expressed as:

text:
[
A
b
]
+
[
A
g
]
⇋
[
A
b
A
g
]

{\displaystyle [Ab]+[Ag]\leftrightharpoons [AbAg]}

text: where [Ab] is the antibody concentration and [Ag] is the antigen concentration, either in free ([Ab],[Ag]) or bound ([AbAg]) state.

text:
The equilibrium association constant can therefore be represented as:

K

a

=

k

o
n

k

o
f
f

=

[
A
b
A
g
]

[
A
b
]
[
A
g
]

{\displaystyle K_{a}={\frac {k_{on}}{k_{off}}}={\frac {[AbAg]}{[Ab][Ag]}}}

text: where K is the equilibrium constant.

text:
Reciprocally the dissociation constant will be:

K

d

=

k

o
f
f

k

o
n

=

[
A
b
]
[
A
g
]

[
A
b
A
g
]

{\displaystyle K_{d}={\frac {k_{off}}{k_{on}}}={\frac {[Ab][Ag]}{[AbAg]}}}

text: However, these equations are applicable only to a single epitope binding, i.e. one antigen on one antibody. Since the antibody necessarily has two paratopes, and in many circumstances complex binding occurs, the multiple binding equilibrium can be summed up as:

text:
K

a

=

k

o
n

k

o
f
f

=

[
A
b
A
g
]

[
A
b
]
[
A
g
]

{\displaystyle K_{a}={\frac {k_{on}}{k_{off}}}={\frac {[AbAg]}{[Ab][Ag]}}}

 = r/c(n-r)

text: where, at equilibrium, c is the concentration of free ligand, r represents the ratio of the concentration of bound ligand to total antibody concentration and n is the maximum number of binding sites per antibody molecule (the antibody valence).

text: The overall strength of the binding of an antibody to an antigen is termed its avidity for that antigen. Since antibodies are bivalent or polyvalent, this is the sum of the strengths of individual antibody-antigen interactions. The strength of an individual interaction between a single binding site on an antibody and its target epitope is termed the affinity of that interaction.

text: Avidity and affinity can be judged by the dissociation constant for the interactions they describe. The lower the dissociation constant, the higher the avidity or affinity, and the stronger the interaction.

text: Application[edit]

text: Antigen-antibody interaction is used in laboratory techniques for serological test of blood compatibility and various pathogenic infections. The most basic is ABO blood group determination, which is useful for blood transfusion.[9] Sophisticated applications include ELISA,[10] enzyme-linked immunospot (Elispot), immunofluorescence, and immunoelectrophoresis.[11][12][13]


document_title: Working income tax benefit

question_text: when did the working income tax benefit start

text: Working income tax benefit

text: The working income tax benefit (WITB) is a refundable tax credit in Canada, similar to the Earned Income Tax Credit (EITC) in the United States. Introduced in 2007, it offers tax relief to working low-income individuals and encourages others to enter the workforce.[1] The WITB has been expanded considerably since its introduction.[2][3][4]

text: Eligibility[edit]

text: To be eligible for the WITB, the applicant or their spouse must be a Canadian resident for income tax purposes of at least 19 years of age as of December 31, and cannot be a full-time student.[5][6] The WITB can be claimed on line 453 of the income tax return if their income exceeds $3,000 for the calendar year. However, the additional paperwork required to claim the credit is complex, involving a  the 42-step process on Schedule 6 of Canada's main income-tax form.[7]

text: Benefits[edit]

text: As of 2016, the WITB is worth up to $1,028 for a single individual and $1,868 for couples and single-parent families. Benefits increase and then decrease with income. At an income of $18,529 for single individuals or $28,576 for families the benefits decrease to $0.[8] WITB is estimated to benefit 1.4 million working Canadians annually, at a cost to the federal government of CDN$1.2 billion.[7] In October 2017, the Liberal government of Justin Trudeau promised to expand the benefit by $500 million annually, beginning in 2019.[7]

text: Consistently since 2009, only about 85% of all working Canadians eligible for the WITB have claimed their benefit, with particularly low uptake in Atlantic Canada and the Prairie provinces.[7] In 2017, this left an estimated CDN$175 million in benefits unclaimed by 240,000 eligible low-income Canadians.[7] This is thought by the Canada Revenue Agency (CRA) to be due to a mixture of lack of awareness and the complexity of the forms required to claim the benefit.[7] CRA is working to increase uptake by CRA is expanding its support for free volunteer tax-preparation services and by scaling up a 2016 pilot project in New Brunswick, which highlighted the program to persons likely eligible for the program and was judged to have had a "positive impact."[7]


document_title: United Kingdom driving test

question_text: when was the driving test introduced in britain

text: United Kingdom driving test

text: History[edit]

text: UK driving licences were introduced by the Motor Car Act 1903 but no test was required.[8]

text: A test for disabled drivers was introduced by the Road Traffic Act 1930.[9]

text: Legislation for compulsory testing was introduced for all new drivers with the Road Traffic Act 1934. The test was initially voluntary to avoid a rush of candidates until 1 June 1935 when all people who had started to drive on or after 1 April 1934 needed to have passed the test.[9]

text: Testing was suspended during World War II,[9] and was suspended again during the Suez Crisis in 1956 to allow examiners help to administer petrol rations.[9]

text: The driving theory test was introduced in July 1996 as a written examination, which was updated to computerised format in 2000.[9]

text: The hazard perception segment of the theory test, was introduced in November 2002.

text: In January 2015, new CGI clips replaced the real-life video clips in the Hazard Perception Test.[10]

text: The current test[edit]

text: Currently, there are two tests (for a car licence) that need to be passed in order to obtain a full driving licence. First the theory test and then, within two years of passing this, the practical test.

text: Theory test[edit]

text: The theory test is made up of two parts, both of which differ according to the type of vehicle licence the candidate is pursuing:

text:
Multiple-choice test
Hazard perception test

tag: ul

text: Both parts must be passed in order to obtain a theory test pass certificate. This enables the candidate to book a practical driving test.[6] Candidates have two years from the date that they passed the first part of their theory test to take their practical test, or they will have to pass both parts of the theory test once again before they can book a practical test.

text: Multiple-choice test[edit]

text: This part of the theory test is performed on a computer system. The test has 50 multiple choice questions and the candidate must answer at least 43 of them correctly to pass.[11] All questions are randomly selected from a bank of just under one thousand on a selection of topics.

text: The test lasts for 57 minutes although candidates with certain special needs can apply for more time.[12] All 50 questions must be answered. The test allows 15 minutes practice time at the start of the exam to get used to answering the questions and how to use the system. To answer a question the candidate simply touches their choice of answer from the listed answers on the computer screen. If a mistake is made the candidate can deselect a choice and reselect a different option. The candidate is allowed to go back to a question at any time and can also flag questions they are unsure of in order to find and return to it quickly and easily later.[11] To pass the test, 43 of the 50 questions (86%) must be answered correctly.[6]

text: For lorry and bus drivers, 100 questions are asked over a 115-minute period, and 85 out of 100 must be answered correctly to pass.

text: Prior to 3 September 2007, the car and motorcycle multiple-choice tests comprised 35 questions, with a pass mark of 30 within a 40-minute time limit.

text: Hazard perception[edit]

text: Candidates watch fourteen one-minute clips (nineteen clips for lorry and bus candidates) filmed from the perspective of a car driver or motorcyclist and have to indicate, usually by clicking a mouse button or touching the screen, when they observe a developing hazard.[13]

text: Practical test[edit]

text: Unless one is converting a foreign licence, it is necessary to have passed both components of the theory test before sitting this exam.[14] Passing the practical test then entitles one to hold a full UK driving licence.[1]

text: The test candidate must produce their provisional licence for the examiner before the test starts.

text: The practical car test can be taken in either a manual or an automatic car; if the test is passed in an automatic car, then the full licence granted will be restricted to automatic cars only.

text: The practical motorcycle test is split into two separate modules - the off-road module and the on-road module. To get a full motorcycle licence, the candidate needs to pass both modules. The target waiting time for a practical driving test is six weeks. However, in practice the waiting time can be considerably longer.[15]

text: Format[edit]

text: The practical car test is taken on the road, with a professionally trained DVSA examiner directing the candidate around a pre-determined route. The examiner marks the candidate for driving faults, serious faults, and dangerous faults. A candidate will fail the test if he or she accumulates any serious or dangerous faults, or more than fifteen driving faults. If a candidate accumulates several driving faults in the same category, the examiner may consider the fault habitual and mark a serious fault in that category. The test usually lasts 38 to 40 minutes in a standard test, or approximately 70 minutes when the candidate is taking an extended test after having had their licence revoked.[16]

text: Eyesight test[edit]

text: Before getting to the car, the examiner will ask the candidate to read a car's number plate at a distance. The distance required is 20.5 metres for an old-style plate (A123 ABC) and 20 metres for a new style plate (AB51 ABC).[17] If the candidate needs glasses to do this, then they must be worn during the test. If the candidate fails to read the first number plate correctly, then the examiner asks the candidate to read a second number plate. If the candidate cannot correctly read the second number plate, then the examiner must use a tape measure to measure the correct distance between the candidate and a third number plate. If the candidate cannot read the third number plate, then the candidate is deemed to have failed and the test will not continue.

text: Vehicle safety questions[edit]

text: Before the candidate is taken out onto the road, the examiner asks two questions about car maintenance and safety. These are phrased in the form "Show me..." and "Tell me..."; as such, this component of the test is often known as "Show me, tell me". For example:

text:
Show me how you would check that the power assisted steering is working before starting a journey.
Open the bonnet, identify where you would check the engine oil level and tell me how you would check that the engine has sufficient oil.

text: A failure to answer one or both of these questions correctly would result in a driving fault being marked against the candidate. The questions that may be asked are changed from time to time. From July 2008, there are 19 different questions which can be asked in 13 different combinations.[18]

text: Controlled stop[edit]

text: The controlled stop, more commonly referred to as the "emergency stop", is an exercise which determines the ability of the candidate to stop the vehicle promptly yet under control during a simulated emergency. The simulation is performed by the examiner raising his or her hand and saying, "STOP!". A controlled stop exercise will be carried out on every extended test and one third of normal tests. This might be an emergency stop, or the candidate might be asked to make a controlled stop in a specific location.[16] During dangerous weather conditions, such as rain and snow, this test can be left out for safety reasons.

text: Manoeuvres[edit]

text: During the test, the examiner will ask the candidate to carry out one manoeuvre from the following list:[19]

text:
Turn in the road, colloquially known as a "3 point turn", although more than 3 moves may be necessary.
Reverse around a corner
Reverse park into a parking space either parallel to the kerb (on road), or oblique or right-angle (in a marked bay in an off-road car park)

text: This change from two manoeuvres to one was introduced to allow time for the independent driving section of the test that was introduced on 4 October 2010.

text: Manoeuvres are selected at random by the examiner depending on the route chosen and conditions on the route.

text: General driving[edit]

text: Generally, the candidate must demonstrate an ability to drive in various road and traffic conditions [20] and react appropriately in actual risk situations.[19] The conditions typically encountered on test include driving in urban areas as well as higher speed limit roads where possible; this includes dual carriageways but not motorways as motorways in Britain can only be used by full licence holders. The object of the test is to ensure that the candidate is well grounded in the basic principles of safe driving, and is sufficiently practised in them to be able to show, at the time of the test, that they are a competent and considerate driver and are not a source of danger to themselves or to other road users. The drive will include two or three normal stops at (and moving away from) the side of the road on level roads as well as on gradients, in addition to a demonstration of moving away from behind a stationary vehicle.[16] The regulations state that the on-road driving time must be no less than 30 minutes.[21] If at any point during the test, the examiner has to intervene with any controls, this will usually result in failure and could be marked on the test report as a dangerous fault.

text: Independent driving[edit]

text: The test includes a 10-minute section of independent driving. It is included in the following practical driving tests:

text:
car
motorcycle module two
large goods vehicle (LGV)
passenger carrying vehicle (PCV) tests
approved driving instructor (ADI) driving ability (sometimes called 'part two')
taxi

text: During the independent driving section, candidates have to drive by:

text:
following traffic signs to a destination, or
following a series of verbal instructions, or
following a combination of both.

text: To help candidates understand where they are to go, the examiner may show them a route diagram. It does not matter if candidates do not remember every direction, nor if they deviate from the intended route unless they commit a driving fault.

text: If there are poor or obscured traffic signs, the examiner will give the candidate directions until they can see the next traffic sign. Candidates will not need to have a detailed knowledge of the area, but will not be allowed to use Automotive navigation system for this part of the test.

text: If the candidate has special needs, the examiner will be able to make reasonable adjustments. For the independent driving section, this could be asking the candidate which method they prefer - following signs, or a series of directions (a maximum of three) [22]

text: As of 4th December 2017

text: The U.K driving test will change, all the relevant changes can be found here driving test or read this article [23]on the new changes being made.