Mandibular central incisor

The mandibular central incisor is the tooth located on the jaw, adjacent to the midline of the face. It is mesial (toward the midline of the face) from both mandibular lateral incisors. As with all incisors, its function include shearing or cutting food during mastication, commonly known as chewing. There are no cusps on the tooth. Instead, the surface area of the tooth used in eating is called an incisal ridge or incisal edge. Though the two are similar, there are some minor differences between the deciduous (baby) mandibular central incisor and that of the permanent mandibular central incisor.


Notation

In the universal system of notation, the deciduous mandibular central incisors are designated by a letter written in uppercase. The right deciduous mandibular central incisor is known as “P”, and the left one is known as “O”. The international notation has a different system of notation. Thus, the right deciduous mandibular central incisor is known as “81″, and the left one is known as “71″.

In the universal system of notation, the permanent mandibular central incisors are designated by a number. The right permanent mandibular central incisor is known as “25″, and the left one is known as “24″. In the Palmer notation, a number is used in conjunction with a symbol designating in which quadrant the tooth is found. For this tooth, the left and right central incisors would have the same number, “1″, but the right one would have the symbol, “┐”, over it, while the left one would have, “┌”. The international notation has a different numbering system than the previous two, and the right permanent mandibular central incisor is known as “41″, and the left one is known as “31″.


Anatomy

The central incisors have fossa on their lingual surfaces.


References

  • Ash, Major M. and Stanley J. Nelson, 2003. Wheeler’s Dental Anatomy, Physiology, and Occlusion. 8th edition.

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Superior alveolar artery

The superior alveolar artery is a branch of the maxillary artery that serves the upper teeth and other related structures.

The superior alveolar artery branches off of the maxillary artery in the pterygopalatine fossa. It descends to the maxilla where it gives off branches that supply the molar and premolar teeth, the maxillary sinus, and the gingivae. The superior alveolar artery divides into the posterior superior alveolar artery and the anterior superior alveolar artery.


References

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Dragonflight

Dragonflight is the first book in the long-running Dragonriders of Pern series by Anne McCaffrey.

The first segment of Dragonflight was a Hugo award–winning novella (called Weyr Search) prior to publication of the entire book.


Plot introduction

Pern is a planet inhabited by humans. The original colonists were reduced to a low level of technology by periodic onslaughts of deadly Thread raining down from the sky. By harnessing the indigenous flying, fire-breathing dragons, humanity finally managed to gain the upper hand. The dragons, with their human riders, destroyed the Thread in the skies over Pern before they were able to burrow into the land and breed. However, an unusually long interval between attacks, centuries in duration, has caused the general population to gradually dismiss the threat and withdraw support from the Weyrs where dragons are bred and trained. By the time of this novel, only one Weyr remains (the other five having mysteriously disappeared at the same time in the last quiet interval), maintaining a precarious hand-to-mouth existence.

Dragons are telepathic; each bonds to a single human being when first hatched. They come in various colors which are generally correlated with their size, blue, green, brown, bronze and gold queens. Bronzes, as the largest males, are by tradition the only ones who compete to win the queens in their mating flights. Queens, however, are always the largest dragons. As their human counterparts are linked mind-to-mind, they also mate at these times.


Plot summary

Dragonflight chronicles the story of Lessa, the sole survivor of the noble ruling family of Ruatha Hold on the northern continent of Pern. When the rest of her family was killed by a cruel usurper, Fax, she survived by disguising herself as a drudge (a menial servant).

F’lar, wingleader at Benden Weyr and rider of the bronze dragon Mnementh, finds Lessa while Searching for candidates to Impress the Queen egg that is about to hatch. After defeating Fax in single combat (following the rules of the Pernese code duello), F’lar convinces Lessa to give up her birthright as Lord Holder of Ruatha Hold and join him at Benden Weyr. Lessa Impresses the Queen dragonet Ramoth and becomes the Weyrwoman, the new co-leader of the last active Weyr. On Ramoth’s first mating flight, Mnementh is the only dragon able to catch her. By Weyr tradition, this makes F’lar the Weyrleader.

Together, Lessa and F’lar warn a dangerously unprepared Pern of the upcoming Thread scourge. They revitalize the Weyr and start working closely with the Lord Holders and the Harpers to prevent the deadly rain of Thread from destroying the Pernese civilization.

However, one Weyr by itself is not enough to defend the planet. In a desperate attempt to increase their numbers, a new queen, Prideth, and her rider, Kylara, are sent between times (a recently rediscovered skill), back 10 turns, giving Prideth time to mature and have Clutches. However, this is still not enough to stem the tide. Stretched to the breaking point, with riders and dragons injured fighting the last Threadfall, Lessa braves death for herself and her dragon by travelling four hundred years into the past to bring the five missing Weyrs forward to the present. Reinforced, Lessa and F’lar are able to save all of Pern.

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Hertwig’s epithelial root sheath

The Hertwig’s epithelial root sheath (frequently abbreviated as “HERS”) is a proliferation of epithelial cells located at the cervical loop of the enamel organ in a developing tooth. Hertwig’s epithelial root sheath initates the formation of dentin in the root of a tooth by causing the differentiation of odontoblasts from the dental papilla. The root sheath eventually disintegrates, but residual pieces that do not completely disappear are seen as epithelial cell rests of Malassez (ERM).


Evolution of HERS

Hertwig’s epithelial root sheath was not discovered in any mammalian species. Instead this epithelial structure was discovered by Oskar Hertwig in 1874 in an amphibian. While in mammalian the HERS is rather a transient structure in amphibians it is more or less a permanent one. Here the root epithelium does not fenestrate like in mammalians. Within vertebrates 3 distinct stages of HERS development can be observed.

  1. In teleosts and chondrichthyans no HERS or root is really formed, and tooth development is restricted to crown development. An inflexible joint is formed between the tooth and the bone at the apical end of the tooth where the epithelium remains open.
  2. In amphibians and non-crocodilian reptiles a continuous root sheath or HERS is formed without fragmentation of the epithelium. Once again a rather rigid connection between bone and tooth is formed at the apical end of the tooth where no epithelium is present.
  3. In crocodilians and mammals the HERS is a transient structure and fragments to form the epithelial cell rests of Malassez. Through the gaps in the root epithelium elements of the periodontal ligament can migrate and form a flexible connection between bone and root.


References

  • Cate, A.R. Ten. Oral Histology: development, structure, and function. 5th ed. 1998. ISBN 0-8151-2952-1.
  • Hertwig, O. (1847) Über das zahnsystem der amphibien und seine bedeutung für die genese des skelets der mundhöhle. Arch. Mikrosk. Anat. EntwMech. 11 (suppl): 55-56
  • Luan, X., Ito, Y. and Diekwish, T.G.H. (2006) Evolution and development of Hertwig’s Epithelial Root Sheath. Dev. Dyn. 235: 1167-1180.
  • Thomas, H.F. (1995) Root formation. Int. J. Dev. Biol. 39: 231-237

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Black raspberry

Black raspberry is a common name for two closely related species of the genus Rubus:

  • Rubus leucodermis in western North America
  • Rubus occidentalis in eastern North America

See also Rubus niveus, a closely related species

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Pulpitis

Pulpitis is an inflammation of the dental pulp.


Causes of Pulpitis

  • Caries that penetrate though the tooth enamel, the dentin, and into the pulp
  • Repeated dental procedures or tooth trauma

Regardless of the cause of pulpitis the inflammation can be associated with a bacterial infection. As in the case of a carie that penetrates the pulp cavity the tooth is no longer sealed to infectious pathogens, where as when the blood supply is cut off to the pulp, bacteria have an opportunity to over take the pulp.

When the pulp becomes inflamed pressure begins to build up in the pulp cavity exerting pressure on the nerve of the tooth and the surrounding tissues. Pressure from inflammation can cause mild to extreme pain, depending upon the severity of the inflammation. Often, pulpitis can create so much pressure on the tooth nerve the individual will have trouble locating the source of the pain, confusing it with neighbouring teeth. Inflammation in the tooth provides a difficult environment for reducing the inflammation in the pulp cavity. Unlike other parts of the body where pressure can dissipate through the surrounding soft tissues and where lymph can reach, the pulp cavity is very different. The dentin surrounding the pulp is hard and does not give under the pressure of the inflammation so the pressure has very little chance of dissipating before pulp necrosis occurs. The pulp cavity inherently provides the body with an immune system response challenge, which makes it very unlikely that the bacterial infection can be eliminated. The pain will usually stop once the pulp has died, however the infection can spread to the ancillary anatomy.


Treatment

Once the pulp has become inflamed the tooth can be diagnostically divided into two categories.

  • reversible pulpitis
  • irreversible pulpitis


Reversible pulpitis

Once the irritant is removed the pulp remains vital and is not unduely affected by the changes.


Irreversible pulpitis

The pulp is irreversibly damaged and necrosis will follow. Pain may not subside after removal of the irritant. Pain may be sharp or dull and throbbing. If there is any drainage then severity of pain is reduced

The tooth may be endodontically treated where by the pulp is removed and replaced by gutta percha. An alternative is extraction of the tooth. This may be required if there is insufficient coronal tissue remaining for restoration once root canal therapy has been completed.

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Sestina

A sestina is a highly structured poem consisting of six six-line stanzas followed by a tercet (called its envoy or tornada), for a total of thirty-nine lines. The same set of six words ends the lines of each of the six-line stanzas, but in a different order each time; if we number the first stanza’s lines 123456, then the words ending the second stanza’s lines appear in the order 615243, then 364125, then 532614, then 451362, and finally 246531. This organization is referred to as retrogradatio cruciata (”retrograde cross”). These six words then appear in the tercet as well, with the tercet’s first line usually containing 1 and 2, its second 3 and 4, and its third 5 and 6 (but other versions exist, described below). English sestinas are usually written in iambic pentameter or another decasyllabic meter.

The sestina was invented in the late 12th century by the Provençal troubadour Arnaut Daniel.

The oldest British example of the form is a double sestina, “You Goat-Herd Gods”, written by Philip Sidney. Writers such as Dante, A. C. Swinburne, Rudyard Kipling, Ezra Pound, W. H. Auden, John Ashbery and Elizabeth Bishop are all noted for having written sestinas of some fame.


Example

As an example of the way in which a sestina’s end-words shift, below is a modern translation of the first two stanzas of a sestina by Dante Alighieri.

I have come, alas, to the great circle of shadow,
to the short day and to the whitening hills,
when the colour is all lost from the grass,
though my desire will not lose its green,
so rooted is it in this hardest stone,
that speaks and feels as though it were a woman.
And likewise this heaven-born woman
stays frozen, like the snow in shadow,
and is unmoved, or moved like a stone,
by the sweet season that warms all the hills,
and makes them alter from pure white to green,
so as to clothe them with the flowers and grass.


How to

Another way to understand the pattern of line ending words for a stanza, given the previous stanza works like this:

If the words at the ends of the lines of the first stanza are A, B, C, D, E, and F

End the first line of the next stanza with the word from last line of the previous one, i.e. F.
End the next line with the word from the first line of the previous stanza, i.e A.
Next use the word from the last line not already used (E).
Next use the word from the first line not already used (B).
Next use the word from the last line not already used (D).
Next use the word from the first line not already used (C).

This gives the final word order: F A E B D C.

Then take this stanza as the model and perform the same transformation to get the next stanza.

You can visualize this as kneading bread. Fold the letters ABCDEF in half. Take the second half, DEF, turn it over to make FED, and push it down onto the first half, ABC. When the two halves are pushed together, they make FAEBDC. Take the second half of that, BDC, turn it over to make CDB, and push it onto the first half, FAE. When you push the halves together, you get CFDABE, and so on.

In writing a sestina it is often helpful to choose end-words which can be used in more than one sense or in more than one grammatical form, e.g as both a noun and a verb.

An alternate, numerical scheme for determining the ordering of elements in a sestina proceeds as follows:

Represent the words terminating the first stanza as: 1 2 3 4 5 6

Grab the outer two elements (1 and 6 here): “1” 2 3 4 5 “6

Group them together at the beginning, reading from right to left (i.e. add them as “6 1″ and not as “1 6″):

                     this operation yields:  "6 1” 2 3 4 5

Grab the next outermost couple (from the original set 1 2 3 4 5 6), in this case that is “2 5″:

                               as shown here:  1 "2” 3 4 “5” 6

Place that group (ordered from right to left as “5 2″) behind the reordered set as previously.

                                    this yields:  "6 1" "5 2" 3 4

Carry out this same set of operations again on the innermost couple (”3 4″) of the original set:

This is highlighted as follows: 1 2 3 4 5 6

   Thus, we arrive at the form of the next stanza in the sestina:  "6 1" "5 2" "4 3"

The overall transformation was: 1 2 3 4 5 6 –> 6 1 5 2 4 3

Carried through, the first six stanzas of a sestina will follow this pattern:

Stanza 1: 1 2 3 4 5 6

Stanza 2: 6 1 5 2 4 3

Stanza 3: 3 6 4 1 2 5

Stanza 4: 5 3 2 6 1 4

Stanza 5: 4 5 1 3 6 2

Stanza 6: 2 4 6 5 3 1

Tercet: Variable.

Regarding the order of the key words in the tercet: Jorge de Sena, a Portuguese poet, indicates that the first line contains words 1 & 2, the second words 3 & 4, and the final line words 5 & 6, in that order. The sestina by Philip Sidney, cited below, uses this order. Other sources specify 1 & 4; 2 & 5; 3 & 6. Sestina writers seem to have felt freer to alter this part of the pattern than the strict rotation and interchange of the end words in the six sestets.


External links

  • Forms of Verse-Sestina
  • Craft of Poetry–Sestina
  • The first sestina, in Provençal and English
  • Dozens of sestinas submitted to McSweeney’s
  • The Sestina Page
  • Guide to Verse Forms - Sestina
  • Sestinas and double sestinas at Poetry X

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Sooli

Cro character
Sooli
Gender Female
Color African
Colored eyes Black
Age Unknown
Only appearance The Legend of Big Thing
Family Old African Tribe
Friends Neandies and Pakka
Portrayer Cree Summer
was a fictional African character from the TV series Cro. She only appeared in one episode. She lost her horse and Cro and Pakka used traps to help catch it.


Appearance

Sooli was African with a large dark brown fur coat (obviously to stay out of the cold).


Old Tribe

Just like Bobb, Sooli had an old tribe, but she got separated. She was probably meant to be a new main character, but the show stopped by then.

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Equity derivative

In finance, an equity derivative is a class of financial instruments whose value is at least partly derived from one or more underlying equity securities. Market participants trade equity derivatives in order to transfer or transform certain risks associated with the underlying security. Options are by far the most common equity derivative, however there are many other types of equity derivatives that are actively traded.


Equity options

Equity options are the most common type of equity derivative. They provide the right, but not the obligation to trade a quantity of stock at a set price at a future time.


Warrants

In finance, a warrant is a security that entitles the holder to buy stock of the company that issued it at a specified price, which is much higher than the stock price at time of issue. Warrants are frequently attached to bonds or preferred stock as a sweetener, allowing the issuer to pay lower interest rates or dividends. They can be used to enhance the yield of the bond, and make them more attractive to potential buyers.


Convertible bonds

Convertible bonds are bonds that can be converted into shares of stock in the issuing company, usually at some pre-announced ratio. It is a hybrid security with debt- and equity-like features. It can be used by investors to obtain the upside of equity-like returns while protecting the downside with regular bond-like coupons.


Equity futures, options and swaps

Investors can gain exposure to the equity markets using futures, options and swaps. These can be done on single stocks, a customized basket of stocks or on an index of stocks. These equity derivatives derive their value from the price of the underlying stock or stocks.


Stock market index futures

Stock market index futures are futures contracts used to replicate the performance of an underlying stock market index. They can be used for hedging against an existing equity position, or speculating on future movements of the index. Indices for futures include well-established indices such as S&P, FTSE, DAX, CAC40 and other G12 country indices. Indices for OTC products are broadly similar, but offer more flexibility.


Equity basket derivatives

Equity basket derivatives are futures, options or swaps where the underlying is a non-index basket of shares. They have similar characteristics to equity index derivatives, but are always traded OTC, as the basket definition is not standardised in the way that an equity index is.


Single-stock futures

Single-stock futures are exchange-traded futures contracts based on an individual underlying security rather than a stock index. Their performance is similar to that of the underlying equity itself, although as futures contracts they are usually traded with greater leverage. Another difference is that holders of long positions in single stock futures typically do not receive dividends and holders of short positions do not pay dividends. Single-stock futures may be cash-settled or physically settled by the transfer of the underlying stocks at expiration, although in the United States only physical settlement is used.


Equity index swaps

An equity index swap is an agreement between two parties to swap two sets of cash flows on predetermined dates for an agreed number of years. The cash flows will be an equity index value swapped, for instance, with LIBOR. Swaps can be considered as being a relatively straight forward way of gaining exposure to an asset class you require. They can also be relatively cost efficient.


Exchange-traded derivatives

Other examples of equity derivative securities include exchange-traded funds and Intellidexes.

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Niyyah

Niyyah is an intent one evokes in his heart to do an act of worship for the sake of Allah (God). Thus, because its seat is in the heart, it does not have to be pronounced verbally. That is why no wording for Niyyah is reported from the Prophet (s.a.s.), nor from any of his companions.

Taken from “The Prescribed Prayer Made Simple” by Tajuddin B. Shu’aib

Niyyah is the the solumn and sincere disire to do something for allah, a muslim mush have niyyah to attend the hajj.

If a Muslim cannot go on the Hajj, for medical reasons etc. then Niyyah will suffice.


External links

  • Niyyah
  • Niyyah of Salah

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Dental follicle

The dental follicle is a sac containing the developing tooth and its odontogenic organ.


See also

  • Tooth development


References

  • Cate, A.R. Ten. Oral Histology: development, structure, and function. 5th ed. 1998. ISBN 0-8151-2952-1.
  • Ross, Michael H., Gordon I. Kaye, and Wojciech Pawlina. Histology: a text and atlas. 4th edition. 2003. ISBN 0-683-30242-6.

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Cavity back

A Cavity back golf club refers to a specific kind of golf iron. In a cavity back iron, most of the weight of the clubhead is distributed around the perimeter of the head, creating a “cavity” in the center of the clubhead. This process maximizes the sweet spot of the clubhead, allowing shots struck slightly off the center of the clubhead to have more distance and control than a similarly off-center shot with a traditional muscleback iron.

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George Michael Moser

George Michael Moser (1706-1783) was a renowned artist and enameller of the 18th century, father of celebrated floral painter Mary Moser, and, with his daughter, among the founder members of the Royal Academy in 1768.

Born in Schaffhausen, Switzerland, Moser trained initially as a coppersmith in Geneva, later learning additional skills as a chaser, goldsmith and engraver.

He moved to London during the 1720s and married Mary Guynier. Surviving works by him include elaborate gold snuff-boxes and watch-cases (including movements by noted watchmakers George Philip Strigel and John Ellicott, among others), and silver candlesticks in the Rococo style.

Moser was the Royal Academy’s first Keeper and as a teacher at the Academy taught many notable artists including William Blake. He also taught at the St Martin’s Lane Academy and was drawing master to the British royal family.


External links

  • Moser’s entry at the UK National Portrait Gallery

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