Definition.

A sequence of vectors formula_1 from a vector space "V" is said to be "linearly dependent", if there exist scalars formula_2, not all zero, such that where formula_4 denotes the zero vector.  Notice that if not all of the scalars are zero, then at least one is non-zero, say formula_5, in which case this equation can be written in the form Thus, formula_7 is shown to be a linear combination of the remaining vectors. A sequence of vectors formula_8 is said to be "linearly independent" if the equation can only be satisfied by formula_10 for formula_11. This implies that no vector in the sequence can be represented as a linear combination of the remaining vectors in the sequence. In other words, a sequence of vectors is linearly independent if the only representation of formula_12 as a linear combination of its vectors is the trivial representation in which all the scalars formula_13 are zero. Even more concisely, a sequence of vectors is linear independent if and only if formula_12 can be represented as a linear combination of its vectors in a unique way.  The alternate definition, that a sequence of vectors is linearly dependent if and only if some vector in that sequence can be written as a linear combination of the other vectors, is only useful when the sequence contains two or more vectors. When the sequence contains no vectors or only one vector, the original definition is used.

Infinite dimensions.

In order to allow the number of linearly independent vectors in a vector space to be countably infinite, it is useful to define linear dependence as follows. More generally, let "V" be a vector space over a field "K", and let {"v" | "i" ∈ "I"} be a family of elements of "V" indexed by the set "I". The family is "linearly dependent" over "K" if there exists a non-empty "finite" subset "J" ⊆ "I" and a family {"a" | "j" ∈ "J"} of elements of "K", all non-zero, such that  A set "X" of elements of "V" is "linearly independent" if the corresponding family {"x"} is linearly independent. Equivalently, a family is dependent if a member is in the closure of the linear span of the rest of the family, i.e., a member is a linear combination of the rest of the family. The trivial case of the empty family must be regarded as linearly independent for theorems to apply.  A set of vectors which is linearly independent and spans some vector space, forms a basis for that vector space. For example, the vector space of all polynomials in "x" over the reals has the (infinite) subset {1, "x", "x",...} as a basis.

Geometric meaning.

A geographic example may help to clarify the concept of linear independence. A person describing the location of a certain place might say, "It is 3 miles north and 4 miles east of here." This is sufficient information to describe the location, because the geographic coordinate system may be considered as a 2-dimensional vector space (ignoring altitude and the curvature of the Earth's surface). The person might add, "The place is 5 miles northeast of here." Although this last statement is "true", it is not necessary.  In this example the "3 miles north" vector and the "4 miles east" vector are linearly independent. That is to say, the north vector cannot be described in terms of the east vector, and vice versa. The third "5 miles northeast" vector is a linear combination of the other two vectors, and it makes the set of vectors "linearly dependent", that is, one of the three vectors is unnecessary.  Also note that if altitude is not ignored, it becomes necessary to add a third vector to the linearly independent set. In general, "n" linearly independent vectors are required to describe all locations in "n"-dimensional space.

Evaluating linear independence.

Vectors in R.

Three vectors: Consider the set of vectors "v" = (1, 1), "v" = (−3, 2) and "v" = (2, 4), then the condition for linear dependence seeks a set of non-zero scalars, such that or  Row reduce this matrix equation by subtracting the first row from the second to obtain, Continue the row reduction by (i) dividing the second row by 5, and then (ii) multiplying by 3 and adding to the first row, that is  We can now rearrange this equation to obtain which shows that non-zero "a" exist such that "v" = (2, 4) can be defined in terms of "v" = (1, 1), "v" = (−3, 2). Thus, the three vectors are linearly dependent.  Two vectors: Now consider the linear dependence of the two vectors "v" = (1, 1), "v" = (−3, 2), and check, or  The same row reduction presented above yields, This shows that "a" = 0, which means that the vectors "v" = (1, 1) and "v" = (−3, 2) are linearly independent.

Vectors in R.

In order to determine if the three vectors in R, are linearly dependent, form the matrix equation,  Row reduce this equation to obtain, Rearrange to solve for v and obtain, This equation is easily solved to define non-zero "a",  where "a" can be chosen arbitrarily. Thus, the vectors "v", "v" and "v" are linearly dependent.

Alternative method using determinants.

An alternative method relies on the fact that "n" vectors in formula_29 are linearly independent if and only if the determinant of the matrix formed by taking the vectors as its columns is non-zero.  In this case, the matrix formed by the vectors is We may write a linear combination of the columns as We are interested in whether "A"Λ = 0 for some nonzero vector Λ. This depends on the determinant of "A", which is Since the determinant is non-zero, the vectors (1, 1) and (−3, 2) are linearly independent.  Otherwise, suppose we have "m" vectors of "n" coordinates, with "m" < "n". Then "A" is an "n"×"m" matrix and Λ is a column vector with "m" entries, and we are again interested in "A"Λ = 0. As we saw previously, this is equivalent to a list of "n" equations. Consider the first "m" rows of "A", the first "m" equations; any solution of the full list of equations must also be true of the reduced list. In fact, if 〈"i"...,"i"〉 is any list of "m" rows, then the equation must be true for those rows.

In the theory of vector spaces, a set of vectors is said to be'if at least one of the vectors in the set can be defined as a linear combination of the others; if no vector in the set can be written in this way, then the vectors are said to be '. These concepts are central to the definition of dimension.


Family.

Eurystheus was the son of Sthenelus and Nicippe, and he was a grandson of the hero Perseus, as was his opponent Heracles. He was married to Antimache, daughter of Amphidamas.  Eurystheus was a cousin of Heracles.

Mythology.

Labours of Heracles.

In the contest of wills between Hera and Zeus over whose candidate would be hero, fated to defeat the remaining creatures representing an old order and bring about the reign of the Twelve Olympians, Eurystheus was Hera's candidate and Heracles—though his name implies that at one archaic stage of myth-making he had carried "Hera's fame"—was the candidate of Zeus. The arena for the actions that would bring about this deep change are the Twelve Labors imposed on Heracles by Eurystheus. The immediate necessity for the Labours of Heracles is as penance for Heracles' murder of his own family, in a fit of madness, which had been sent by Hera; however, further human rather than mythic motivation is supplied by mythographers who note that their respective families had been rivals for the throne of Mycenae. Details of the individual episodes may be found in the article on the Labours of Heracles, but Hera was connected with all of the opponents Heracles had to overcome.  Heracles' human stepfather Amphitryon was also a grandson of Perseus, and since Amphitryon's father (Alcaeus) was older than Eurystheus' father (Sthenelus), he might have received the kingdom, but Sthenelus had banished Amphitryon for accidentally killing (a familiar mytheme) the eldest son in the family (Electryon). When, shortly before his son Heracles was born, Zeus proclaimed the next-born descendant of Perseus should get the kingdom, Hera thwarted his ambitions by delaying Alcmene's labour and having her candidate Eurystheus born prematurely.Heracles' first task was to slay the Nemean Lion and bring back its skin, which Heracles decided to wear. Eurystheus was so scared by Heracles' fearsome guise that he hid in a subterranean bronze winejar, and from that moment forth all labors were communicated to Heracles through a herald, Copreus.  For his second labour, to slay the Lernaean Hydra, Heracles took with him his nephew, Iolaus, as a charioteer. When Eurystheus found out that Heracles' nephew had helped him he declared that the labour had not been completed alone and as a result did not count towards the ten labours set for him.  Eurystheus' third task did not involve killing a beast, but capturing one alive—the Ceryneian Hind, a golden-horned hind or doe sacred to Artemis. Heracles knew that he had to return the hind, as he had promised, to Artemis, so he agreed to hand it over on the condition that Eurystheus himself come out and take it from him. Eurystheus did come out, but the moment Heracles let the hind go, she sprinted back to her mistress, and Heracles departed, saying that Eurystheus had not been quick enough.  When Heracles returned with the Erymanthian Boar, Eurystheus was again frightened and hid in his jar, begging Heracles to get rid of the beast; Heracles obliged.  The fifth labour proposed by Eurystheus was to clear out the numerous stables of Augeias. Striking a deal with Augeias, Heracles proposed a payment of a tenth of Augeias' cattle if the labour was completed successfully. Not believing the task feasible, Augeias agreed, asking his son Phyleus to witness. Heracles rerouted two nearby rivers (Alpheis and Peneios) through the stable, clearing out the dung rapidly. When Augeias learned of Heracles' bargain for the task, he refused payment. Heracles brought the case to court, and Phyleus testified against his father. Enraged, Augeias banished both Phyleus and Heracles from the land before the court had cast their vote. However, Eurystheus refused to credit the labour to Heracles, as he had performed it for payment. So Heracles went and drove Augeias out of the kingdom and installed Phyleus as king. Heracles then took his tenth of the cattle and left them to graze in a field by his home.  For his sixth labour, Heracles had to drive the Stymphalian Birds off the marshes they plagued. He did so, shooting down several birds with his Hydra-poisoned arrows and bringing them back to Eurystheus as proof.  For his seventh labour, Heracles captured the Cretan Bull. He used a lasso and rode it back to his cousin. Eurystheus offered to sacrifice the bull to Hera his patron, who hated Heracles. She refused the sacrifice because it reflected glory on Heracles. The bull was released and wandered to Marathon, becoming known as the Marathonian Bull.  When Heracles brought back the man-eating Mares of Diomedes successfully, Eurystheus dedicated the horses to Hera and allowed them to roam freely in the Argolid. Bucephalus, Alexander the Great's horse, was said to be descended from these mares.  To acquire the belt of Hippolyte, queen of the Amazons was Heracles ninth task. This task was at the request of Eurystheus' daughter, Admete. For the tenth labour, he stole the cattle of the giant Geryon, which Eurystheus then had sacrificed to Hera.  To extend what may have once been ten Labours to the canonical dozen, it was said that Eurystheus didn't count the Hydra, as he was assisted, nor the Augean stables, as Heracles received payment for his work. For the eleventh labour Heracles had to obtain the Apples of the Hesperides; he convinced their father, the Titan Atlas, to help him, but did his share of work by temporarily holding up the sky in the Titan's stead. For his final labour, he was to capture Cerberus, the three-headed hound that guarded the entrance to Hades. When he managed to bring the struggling animal back, the terrified Eurystheus hid in his jar one more time, begging Heracles to leave for good and take the dog with him.

Death.

After Heracles died, Eurystheus remained bitter over the indignity the hero had caused him. He attempted to destroy Heracles' many children (the Heracleidae, led by Hyllus), who fled to Athens. He attacked the city but was soundly defeated, and Eurystheus and his sons were killed. Though it is widely told that Hyllus killed Eurystheus. The stories about the killer of Eurystheus and the fate of his corpse vary, but the Athenians believed the burial site of Eurystheus remained on their soil and served to protect the country against the descendants of Heracles, who traditionally included the Spartans and Argives.  After Eurystheus' death, the brothers Atreus and Thyestes, whom he had left in charge during his absence, took over the city, the former exiling the latter and assuming the kingship, while Tiryns returned to the overlordship of Argos.

Eurystheus in Euripides.

Eurystheus was a character in "Heracleidae", a play by Euripides. Macaria, one of the daughters of Heracles, and her brothers and sisters hid from Eurystheus in Athens, ruled by King Demophon. As Eurystheus prepared to attack, an oracle told Demophon that he would win if and only if a noble woman was sacrificed to Persephone. Macaria volunteered for the sacrifice and a spring was named the Macarian spring in her honor. Eurystheus speaks prophetically of his burial within Attica, claiming that he will be an anti-hero of sorts, though one who will eventually protect the Athenians.

In Greek mythology, Eurystheus (; meaning "broad strength" in folk etymology and pronounced ) was king of Tiryns, one of three Mycenaean strongholds in the Argolid, although other authors including Homer and Euripides cast him as ruler of Argos.


Biography.

Pausanias was born into a Greek family and was probably a native of Lydia; he was certainly familiar with the western coast of Asia Minor, but his travels extended far beyond the limits of Ionia. Before visiting Greece, he had been to Antioch, Joppa, and Jerusalem, and to the banks of the River Jordan. In Egypt, he had seen the pyramids. While at the temple of Ammon, he had been shown the hymn once sent to that shrine by Pindar. In Macedonia, he appears to have seen the tomb said to be that of Orpheus in Libethra (modern Leivithra). Crossing over to Italy, he had seen something of the cities of Campania and of the wonders of Rome. He was one of the first known to write of seeing the ruins of Troy, Alexandria Troas, and Mycenae.

Work.

Pausanias' "Description of Greece" is in ten books, each dedicated to some portion of Greece. He begins his tour in Attica (), where the city of Athens and its demes dominate the discussion. Subsequent books describe Corinthia () (second book), Laconia () (third), Messenia () (fourth), Elis () (fifth and sixth), Achaea () (seventh), Arcadia () (eighth), Boetia () (ninth), Phocis () and Ozolian Locris () (tenth). The project is more than topographical; it is a cultural geography. Pausanias digresses from the description of architectural and artistic objects to review the mythological and historical underpinnings of the society that produced them. As a Greek writing under the auspices of the Roman empire, he was in an awkward cultural space, between the glories of the Greek past he was so keen to describe and the realities of a Greece beholden to Rome as a dominating imperial force. His work bears the marks of his attempt to navigate that space and establish an identity for Roman Greece.  He is not a naturalist, although from time to time, he does comment on the physical realities of the Greek landscape. He notices the pine trees on the sandy coast of Elis, the deer and the wild boars in the oak woods of Phelloe, and the crows amid the giant oak trees of Alalcomenae. It is mainly in the last section that Pausanias touches on the products of nature, such as the wild strawberries of Helicon, the date palms of Aulis, and the olive oil of Tithorea, as well as the tortoises of Arcadia and the "white blackbirds" of Cyllene.  Pausanias is most at home in describing the religious art and architecture of Olympia and of Delphi. Yet, even in the most secluded regions of Greece, he is fascinated by all kinds of depictions of deities, holy relics, and many other sacred and mysterious objects. At Thebes he views the shields of those who died at the Battle of Leuctra, the ruins of the house of Pindar, and the statues of Hesiod, Arion, Thamyris, and Orpheus in the grove of the Muses on Helicon, as well as the portraits of Corinna at Tanagra and of Polybius in the cities of Arcadia.  Pausanias has the instincts of an antiquary. As his modern editor, Christian Habicht, has said, Unlike a Baedeker guide, in "Periegesis" Pausanias stops for a brief excursus on a point of ancient ritual or to tell an apposite myth, in a genre that would not become popular again until the early nineteenth century. In the topographical part of his work, Pausanias is fond of digressions on the wonders of nature, the signs that herald the approach of an earthquake, the phenomena of the tides, the ice-bound seas of the north, and the noonday sun that at the summer solstice, casts no shadow at Syene (Aswan). While he never doubts the existence of the deities and heroes, he sometimes criticizes the myths and legends relating to them. His descriptions of monuments of art are plain and unadorned. They bear the impression of reality, and their accuracy is confirmed by the extant remains. He is perfectly frank in his confessions of ignorance. When he quotes a book at second hand he takes pains to say so.  The work left faint traces in the known Greek corpus. "It was not read", Habicht relates; "there is not a single mention of the author, not a single quotation from it, not a whisper before Stephanus Byzantius in the sixth century, and only two or three references to it throughout the Middle Ages." The only manuscripts of Pausanias are three fifteenth-century copies, full of errors and lacunae, which all appear to depend on a single manuscript that survived to be copied. Niccolò Niccoli had this archetype in Florence in 1418. At his death in 1437, it went to the library of San Marco, Florence, then it disappeared after 1500.  Until twentieth-century archaeologists concluded that Pausanias was a reliable guide to the sites they were excavating, Pausanias was largely dismissed by nineteenth- and early twentieth-century classicists of a purely literary bent: they tended to follow the usually authoritative Wilamowitz in regarding him as little more than a purveyor of second-hand accounts, who, it was suggested, had not visited most of the places he described. Habicht (1985) describes an episode in which Wilamowitz was led astray by his misreading of Pausanias in front of an august party of travellers in 1873, and attributes to it Wilamowitz's lifelong antipathy and distrust of Pausanias. Modern archaeological research, however, has tended to vindicate Pausanias.

Pausanias (; "Pausanías"; ) was a Greek traveler and geographer of the second century AD who lived in the time of Roman emperors Hadrian, Antoninus Pius, and Marcus Aurelius. He is famous for his "Description of Greece" (, "Hellados Periegesis"), a lengthy work that describes ancient Greece from his firsthand observations. This work provides crucial information for making links between classical literature and modern archaeology. Andrew Stewart assesses him as:


Modern ephemeris.

For scientific uses, a modern planetary ephemeris comprises software that generates positions of planets and often of their satellites, asteroids, or comets, at virtually any time desired by the user.  Typically, such ephemerides cover several centuries, past and future; the future ones can be covered because the field of celestial mechanics has developed several accurate theories. Nevertheless, there are secular phenomena which cannot adequately be considered by ephemerides. The greatest uncertainties in the positions of planets are caused by the perturbations of numerous asteroids, most of whose masses and orbits are poorly known, rendering their effect uncertain. Reflecting the continuing influx of new data and observations, NASA's Jet Propulsion Laboratory (JPL) has revised its published ephemerides nearly every year for the past 20 years.  Solar System ephemerides are essential for the navigation of spacecraft and for all kinds of space observations of the planets, their natural satellites, stars, and galaxies.  Scientific ephemerides for sky observers mostly contain the positions of celestial bodies in right ascension and declination, because these coordinates are the most frequently used on star maps and telescopes. The equinox of the coordinate system must be given. It is, in nearly all cases, either the actual equinox (the equinox valid for that moment, often referred to as "of date" or "current"), or that of one of the "standard" equinoxes, typically J2000.0, B1950.0, or J1900. Star maps almost always use one of the standard equinoxes.  Scientific ephemerides often contain further useful data about the moon, planet, asteroid, or comet beyond the pure coordinates in the sky, such as elongation to the Sun, brightness, distance, velocity, apparent diameter in the sky, phase angle, times of rise, transit, and set, etc. Ephemerides of the planet Saturn also sometimes contain the apparent inclination of its ring.  Celestial navigation serves as a backup to the Global Positioning System. Software is widely available to assist with this form of navigation; some of this software has a self-contained ephemeris. When software is used that does not contain an ephemeris, or if no software is used, position data for celestial objects may be obtained from the modern "Nautical Almanac" or "Air Almanac".  An ephemeris is usually only correct for a particular location on the Earth. In many cases, the differences are too small to matter. However, for nearby asteroids or the Moon, they can be quite important.  Other modern ephemerides recently created are the EPM (Ephemerides of Planets and the Moon), from the Russian Institute for Applied Astronomy of the Russian Academy of Sciences, and the INPOP ("") by the French IMCCE.

In astronomy and celestial navigation, an ephemeris (plural: ephemerides) gives the trajectory of naturally occurring astronomical objects as well as artificial satellites in the sky, i.e., the position (and possibly velocity) over time. The etymology is and. Historically, positions were given as printed tables of values, given at regular intervals of date and time. The calculation of these tables was one of the first applications of mechanical computers. Modern ephemerides are often computed electronically, from mathematical models of the motion of astronomical objects and the Earth. However, printed ephemerides are still produced, as they are useful when computational devices are not available.


Naming.

"Welwitschia" is named after the Austrian botanist and doctor Friedrich Welwitsch, who was the first European to describe the plant, in 1859 in present-day Angola. Welwitsch was so overwhelmed by the plant that he, "could do nothing but kneel down and gaze at it, half in fear lest a touch should prove it a figment of the imagination." Joseph Dalton Hooker of the Linnean Society of London, using Welwitsch's description and collected material along with material from the artist Thomas Baines who had independently recorded the plant in Namibia, described the species.  Welwitsch proposed calling the genus "Tumboa" after what he believed to be the local name, "tumbo". Hooker asked Welwitsch for permission to name the genus "Welwitschia" instead. Welwitsch concurred and supplied some well-preserved material from which Hooker was able to make substantial progress in determining its botanical affinities. The taxonomy of "Welwitschia" subsequently changed intermittently with the development of new classification systems (see Flowering plants: History of classification), however, its current taxonomic status is essentially the same as Hooker's placement.  Most botanists have treated "Welwitschia" as a distinct monotypic genus in a monotypic family or even order. Most recent systems place "Welwitschia mirabilis" in its own family Welwitschiaceae in the gymnosperm order Gnetales.

Biology.

After germination, the seedling produces two cotyledons which grow to in length, and have reticulate venation. Subsequently, two foliage leaves are produced at the edge of a woody bilobed crown. The permanent leaves are opposite (at right angles to the cotyledons), amphistomatic (producing stomata on both sides of the leaf), parallel-veined and ribbon-shaped. Shortly after the appearance of the foliage leaves, the apical meristem dies and meristematic activity is transferred to the periphery of the crown.  The two foliage leaves grow continuously from a basal meristem reaching lengths up to. The tips of the leaves split and fray into several well-separated strap-shaped sections by the distortions of the woody portions surrounding the apical slit, and also by wind and adventitious external injuries. The largest specimens may be no more than tall above ground, but the circumference of the leaves in contact with the sand may exceed.  "Welwitschia" has an elongated shallow root system consisting of "a tapering taproot with one or more non-tapering extensions, some pronounced lateral roots, and a network of delicate spongy roots" and a woody fibrous unbranched main stem. The roots extend to a depth roughly equal to the span of the living leaves from tip to tip. The main stem consists of an unbranched woody crown roughly shaped like an inverted cone. The only branching in the shoot system occurs in the reproductive branches, which bear strobili.  The species is dioecious, with separate male and female plants. Fertilization is carried out by insects including flies and true bugs. The commonest of the true bugs attending "Welwitschia" is a member of the family Pyrrhocoridae, "Probergrothius angolensis", but a hypothesized role in pollination has so far not been demonstrated. Infrequently, wasps and bees also play a role as pollinators of "Welwitschia". At least some of the pollinators are attracted by "nectar" produced on both male and female strobili.  "Welwitschia" has been classified as a CAM plant (crassulacean acid metabolism) after reconciliation of some initially contradictory and confusing data. There are however some very puzzling aspects to the matter; for example, the employment of the CAM metabolism is very slight, which was part of the reason that it took so long to establish its presence at all; it is not understood why this should be.  The age of individual plants is difficult to assess, but many plants may be over 1000 years old. Some individuals may be more than 2000 years old. Because "Welwitschia" only produces a single pair of foliage leaves, the plant was thought by some to be neotenic, consisting essentially of a "giant seedling." However, research showed that its anatomy is not consistent with the giant seedling idea. Instead, the plant is more accurately thought of as achieving its unusual morphology as a result of having "lost its head" (apical meristem) at an early stage.

Distribution and habitat.

"Welwitschia mirabilis" is endemic to the Kaokoveld Desert, which lies within the Namib Desert. The population is distributed southwards from the Bentiaba River in southern Angola, to the Kuiseb River in Namibia, and up to inland of the coast. The area is extremely arid: the coast is recorded as having almost zero rainfall, while less than of rain falls annually below the escarpment in the wet season from February to April. Populations tend to occur in ephemeral water courses, indicating a dependence on ground water in addition to precipitation from fog.

Cultivation.

"Welwitschia mirabilis" grows readily from seed, which may be bought from specialty seed dealers. The seeds have been shown to display orthodox seed behavior, which in general means that they may be stored for long periods at suitably low humidity and temperature. "Welwitschia" seeds naturally develop suitably low water concentrations as they ripen.  Removal of the outer seed coverings enhances germination performance, which suggests that the seeds may display non-deep physiological dormancy. On planting the seed it is necessary to keep it moist, but not immersed in water, for the first two weeks of cultivation; it has been suggested that soaking the seeds in water before planting interferes with germination. Seeds collected from the wild often are heavily contaminated with spores of the fungus "Aspergillus niger var. phoenicis", which causes them to rot shortly after they germinate.  The fungal inoculum infects the growing cones of "W. mirabilis" early during their development, and a sharp increase in infection occurs when the pollination drops appear; through those drops the fungal spores may gain access to the interior of the developing seed. Seeds in the wild may therefore be obliterated through fungal action even before they are fully developed. Seeds from botanical gardens or other cultivated sources are much cleaner and less likely to rot. The fungicide tebuconazole may be useful in controlling limited "A. niger" seed infection.

Conservation.

The population of "Welwitschia mirabilis" in the wild is reasonably satisfactory at present. Plants in Angola are better protected than those in Namibia, because of the relatively high concentration of land mines in Angola, which keep collectors away.  Although "Welwitschia mirabilis" is not at present immediately threatened, there being abundant populations over a large area, its status is far from secure; its recruitment and growth rates are low, and its range, though wide, covers only a single compact, ecologically limited and vulnerable area. The remarkable longevity of Welwitschia favours its survival of temporary periods adverse to reproduction, but it offers no protection against circumstances of direct threat, such as overgrazing and disease. Fungal infection of female cones severely reduces seed viability, reducing already inherently low recruitment. Other threats include injury from off-road vehicles, collection of wild plants and overgrazing by zebras, rhinos, and domestic animals.

Heraldry.

The plant figures as a charge in the national coat of arms of Namibia.

Welwitschia is a monotypic gymnosperm genus, comprising solely the distinctive "Welwitschia mirabilis", endemic to the Namib desert within Namibia and Angola. The plant is commonly known simply as welwitschia in English, but the name tree tumbo is also used. It is called "kharos" or "khurub" in Nama, "tweeblaarkanniedood" in Afrikaans, "nyanka" in Damara, and "onyanga" in Herero. "Welwitschia" is the only living genus of the family Welwitschiaceae and order Welwitschiales, in the division Gnetophyta. Informal sources commonly refer to the plant as a "living fossil".


Biography.

Family.

Born in Königsberg, he was the third son of Frederick William, Elector of Brandenburg by his father's first marriage to Louise Henriette of Orange-Nassau, eldest daughter of Frederick Henry, Prince of Orange and Amalia of Solms-Braunfels. His maternal cousin was King William III of England. Upon the death of his father on 29 April 1688, Frederick became Elector Frederick III of Brandenburg and Duke of Prussia. Right after ascending the throne Frederick founded a new city southerly adjacent to Dorotheenstadt and named it after himself, the Friedrichstadt.

Military career.

Frederick was noted for his opposition to France, in contrast to his father who had sought an alliance with Louis XIV. Frederick took Brandenburg into the League of Augsburg against France and in 1689 led military forces into the field as part of the allied coalition. That year an army under his command besieged and captured Bonn. Despite this opposition to France (a characteristic that was even more prominent in his son and heir) he was fond of French culture, and styled his court in imitation of that of Louis XIV.

Reign as King.

The Hohenzollern state was then known as Brandenburg-Prussia. The family's main possessions were the Margraviate of Brandenburg within the Holy Roman Empire and the Duchy of Prussia outside of the Empire, ruled as a personal union. Although he was the Margrave and Prince-elector of Brandenburg and the Duke of Prussia, Frederick desired the more prestigious title of king. However, according to Germanic law at that time, no kingdoms could exist within the Holy Roman Empire, with the exception of the Kingdom of Bohemia which belonged to the Holy Roman Emperor.  In the Crown Treaty of 16 November 1700, Frederick persuaded Leopold I, Archduke of Austria and Holy Roman Emperor, to allow Prussia to be elevated to a kingdom. This agreement was ostensibly given in exchange for an alliance against King Louis XIV in the War of the Spanish Succession and the provision of 8,000 Prussian troops to Leopold's service. Frederick argued that Prussia had never been part of the Holy Roman Empire, and he ruled over it with full sovereignty. Therefore, he said, there was no legal or political barrier to letting him rule it as a kingdom. Frederick was aided in the negotiations by Charles Ancillon.  Frederick crowned himself on 18 January 1701 in Königsberg. Although he did so with the Emperor's consent, and also with formal acknowledgement from Augustus II the Strong, Elector of Saxony, who held the title of King of Poland, the Polish-Lithuanian Diet (Sejm) raised objections, and viewed the coronation as illegal. In fact, according to the terms of the Treaty of Wehlau and Bromberg, the House of Hohenzollern's sovereignty over the Duchy of Prussia was not absolute but contingent on the continuation of the male line (in the absence of which the duchy would revert to the Polish crown). Therefore, out of deference to the region's historic ties to the Polish crown, Frederick made the symbolic concession of calling himself "King in Prussia" instead of "King of Prussia".  His royalty was, in any case, limited to Prussia and did not reduce the rights of the Emperor in the portions of his domains that were still part of the Holy Roman Empire. In other words, while he was a king in Prussia, he was still only an elector under the suzerainty of the Holy Roman Emperor in Brandenburg. Legally, the Hohenzollern state was still a personal union between Brandenburg and Prussia. However, by the time Frederick crowned himself as king, the emperor's authority over Brandenburg (and the rest of the empire) was only nominal, and in practice it soon came to be treated as part of the Prussian kingdom rather than as a separate entity. His grandson, Frederick the Great, was the first Prussian king to formally style himself "King of Prussia".  Frederick was a patron of the arts and learning. The Akademie der Künste in Berlin was founded by Frederick in 1696, as was the Academy of Sciences in 1700, though the latter was closed down by his son as an economic measure; it was reopened in 1740 by his grandson, Frederick II. Frederick also appointed Jacob Paul von Gundling as Professor of History and Law at the Berlin Knights Academy in 1705, and as historian at the Higher Herald's Office in 1706.  Frederick died in Berlin in 1713 and is entombed in the Berliner Dom.  His grandson, Frederick the Great, referred to Frederick I as "the mercenary king", due to the fact that he greatly profited from the hiring of his Prussian troops to defend other territories, such as in northern Italy against the French. "All in all," he wrote of his grandfather, "he was great in small matters, and small in great matters."

Marriages and children.

Frederick was married three times: He also had an official mistress, Catharina von Wartenberg, between 1696 and 1711. However, he was never known to make use of her services, being deeply in love with his first wife.

Frederick I (; 11 July 1657 – 25 February 1713), of the Hohenzollern dynasty, was (as Frederick III) Elector of Brandenburg (1688–1713) and Duke of Prussia in personal union (Brandenburg-Prussia). The latter function he upgraded to royalty, becoming the first King in Prussia (1701–1713). From 1707 he was in personal union the sovereign prince of the Principality of Neuchâtel (). He was also the paternal grandfather of Frederick the Great.


Biography.

Mansfeld was an illegitimate son of Count Peter Ernst von Mansfeld (1517–1604), a member of the comital House of Mansfeld and royal Spanish stadtholder. He was raised in the Catholic faith at his father's palace in Luxembourg.  He gained his earliest military experiences during the Long War in Hungary, where his elder half-brother Charles (1543–1595), also a soldier of renown, held a high command in the imperial army. While his brother succumbed to an epidemic within short time, young Ernst stayed at the theatre of war for several years. In the War of the Jülich Succession he served under Archduke Leopold V of Austria, until that prince's ingratitude, real or fancied, drove him into the arms of the enemies of the House of Habsburg. Although he remained a Roman Catholic, from about 1610 he openly allied himself with the Protestant princes, and during the earlier part of the Thirty Years' War he was one of their foremost champions.  He was despatched by Charles Emmanuel, Duke of Savoy, at the head of about 2000 men to aid the revolting Bohemians when war broke out in 1618. He took Pilsen, but in the summer of 1619 he was defeated at the Battle of Sablat; after this he offered his services to the Emperor Ferdinand II and remained inactive while the titular king of Bohemia, Frederick V, Elector Palatine of the Rhine, was driven in headlong rout from Prague. Mansfeld, however, was soon appointed by Frederick to command his army in Bohemia, and in 1621 he took up his position in the Upper Palatinate, successfully resisting the efforts made by Tilly to dislodge him.  From the Upper Palatinate, he passed into the Rhenish Palatinate. Here he relieved Frankenthal and took Hagenau; then, joined by his master, the elector Frederick, he defeated Tilly at Wiesloch (25 April 1622) and plundered Alsace and Hesse. But Mansfeld's ravages were not confined to the lands of his enemies; they were ruinous to the districts he was commissioned to defend.  At length Frederick was obliged to dismiss Mansfeld's troops from his service. Then joining Christian of Brunswick the count led his army through Lorraine, devastating the country as he went, and in August 1622 was defeated by the Spaniards at Fleurus. He next entered the service of the United Provinces and took up his quarters in East Frisia, capturing fortresses and inflicting great hardships upon the inhabitants. A mercenary and a leader of mercenaries, Mansfeld often interrupted his campaigns by journeys made for the purpose of raising money, or in other words of selling his services to the highest bidder, and in these diplomatic matters he showed considerable skill.  About 1624 he paid three visits to London, where he was hailed as a hero by the populace, and at least one to Paris. James I, being the father-in-law of Frederick V, Elector Palatine, was anxious to furnish him with men and money for the recovery of the Palatinate, but it was not until January 1625 that Mansfeld and his army of "raw and poor rascals" sailed from Dover to the Netherlands before failing to relieve the siege of Breda. Later in the year, the Thirty Years' War having been renewed under the leadership of Christian IV of Denmark, he re-entered Germany to take part therein. But on 25 April 1626 Wallenstein inflicted a severe defeat upon him at the bridge of Dessau. Mansfeld, however, quickly raised another army, with which he intended to attack the hereditary lands of the house of Austria, and pursued by Wallenstein he pressed forward towards Hungary, where he hoped to accomplish his purpose by the aid of Bethlen Gábor, prince of Transylvania. But when Bethlen changed his policy and made peace with the emperor, Mansfeld was compelled to disband his troops. He set out for Venice, but when he reached Rakovica near Sarajevo, in Bosnia, he was taken ill, and here he died on 29 November 1626, probably from a hemorrhage. He was buried at Split.

Peter Ernst, count of Mansfeld (; c. 158029 November 1626), or simply Ernst von Mansfeld, was a German military commander who, despite being a Catholic, fought for the Protestants during the early years of the Thirty Years' War.


Planning the treaties.

German foreign minister Gustav Stresemann made his highest priority the restoration of German prestige and privileges as a leading European nation. French withdrawal from the Occupation of the Ruhr was scheduled for January 1925, but Stresemann sensed that France was very nervous about its security and might cancel the withdrawal. Having realized that France deeply desired a British guarantee of its postwar borders, but that London was reluctant, Stresemann came up with a plan whereby all sides would get what they wanted: through a series of treaties that promised these guarantees. Upon hearing this proposal, British Foreign Minister Austen Chamberlain enthusiastically agreed. France realized that its occupation of the Ruhr had caused more financial and diplomatic damage than it was worth. The foreign ministers then convened in the Swiss resort of Locarno in October 1925, where they came to an agreement on the treaties.  The first treaty was the most critical: a mutual guarantee of the frontiers of Belgium, France, and Germany, guaranteed by Britain and Italy. The second and third treaties called for arbitration between Germany and Belgium, and Germany and France, regarding future disputes. The fourth and fifth were similar arbitration treaties between Germany and Poland, and Germany and Czechoslovakia. Poland especially, and Czechoslovakia as well, felt threatened by the Locarno agreements and these treaties were an attempt to reassure them. Thanks to the Dawes Plan, Germany was now making regular reparations payments. The success of the Locarno agreements led to the admission of Germany to the League of Nations in September 1926, with a seat on its council as a permanent member.

Goals.

For the British government, the main goals were promoting Franco-German reconciliation, and the expectation that reconciliation would lead to France dissolving its "Cordon sanitaire", as the French alliance system in Eastern Europe was known between the wars. If France were to dissolve its alliances in Eastern Europe, the Poles and Czechoslovaks would peacefully hand over the territories claimed by Germany such as the Sudetenland, the Polish Corridor, and the Free City of Danzig (modern Gdańsk, Poland).

Parties and agreement.

The principal treaty concluded at Locarno was the Rhineland Pact between Germany, France, Belgium, Great Britain, and Italy. Germany formally recognised its new western borders acted by the Treaty of Versailles. Furthermore, the first three signatories undertook not to attack each other, with the latter two acting as guarantors. In the event of aggression by any of the first three states against another, all other parties were to assist the country under attack.  Germany also agreed to sign arbitration conventions with France and Belgium and arbitration treaties with Poland and Czechoslovakia, undertaking to refer future disputes to an arbitration tribunal or to the Permanent Court of International Justice.  France signed further treaties with Poland and Czechoslovakia, pledging mutual assistance in the event of conflict with Germany. These essentially reaffirmed existing treaties of alliance concluded by France with Poland on 19 February 1921 and with Czechoslovakia on 25 January 1924. These treaties also showed that relations between France and Germany had not improved to a large extent.

Effect.

The Locarno Treaties marked a dramatic improvement in the political climate of western Europe in 1925–1930. They promoted expectations for continued peaceful settlements, often called the "spirit of Locarno". This spirit was made concrete when Germany joined the League in 1926, and the withdrawal of Allied troops occupying Germany's Rhineland. The Nobel Peace Prize was given to the lead negotiators of the treaty, going to Sir Austen Chamberlain in 1925 and jointly to Aristide Briand and Gustav Stresemann in 1926.  Historian Sally Marks says: Hitler repudiated Locarno by sending troops into the demilitarized Rhineland on 7 March 1936.

Anger in Poland.

In Poland, the public humiliation received by Polish diplomats was one of the contributing factors to the fall of the Grabski cabinet. Locarno contributed to the worsening of the atmosphere between Poland and France, weakening the French-Polish alliance. Józef Beck ridiculed the treaties saying, "Germany was officially asked to attack the east, in return for peace in the west." Józef Piłsudski would say that "every honest Pole spits when he hears this word [Locarno]". Proposals in 1934 for an "eastern Locarno" pact securing Germany's eastern frontiers foundered on German opposition and on Poland's insistence that its eastern borders should be covered by a western guarantee of her borders. The Locarno treaty was heavily undermined by the Franco-Soviet Treaty of Mutual Assistance on 2 May 1935, which the German government claimed was a violation of its "spirit".

The Locarno Treaties were seven agreements negotiated at Locarno, Switzerland, on 5–16 October 1925 and formally signed in London on 1 December, in which the First World War Western European Allied powers and the new states of Central and Eastern Europe sought to secure the post-war territorial settlement, and return normalizing relations with the defeated German Reich (the Weimar Republic). It also stated that Germany would never go to war with the other countries. Locarno divided borders in Europe into two categories: western, which were guaranteed by Locarno treaties, and eastern borders of Germany with Poland, which were open for revision.


History.

The beautiful medieval town, which remains well preserved to this day, was mentioned as a city for the first time in 1218, after Count Hugo von Montfort built the "Schattenburg", a castle which still is the major landmark of Feldkirch. Other sights in the town include the cathedral of St. Nikolaus from the late Gothic period. Feldkirch was the birthplace of Rheticus, and is currently the seat of the Roman Catholic Diocese of Feldkirch. From 1651–1773 and from 1856–1979, Feldkirch was the home of the Jesuit school Stella Matutina.  March 1799 saw two clashes between the forces of the First French Republic and the Habsburg Monarchy. On the 7th, Nicolas Oudinot with 9,000 French soldiers defeated Friedrich Freiherr von Hotze with 6,000 Austrians. The Battle of Feldkirch occurred on 23 March when André Masséna and 12,000 Frenchmen were beaten by Franz Jellacic and 5,500 Austrians.

Economy and infrastructure.

Transport.

Feldkirch has had its own local bus network since 1993, which currently consists of 8 lines, including buses which run to the north of neighbouring Liechtenstein. The bus system works together with Vorarlberg's bus system which provides several supra-regional lines starting and ending in Feldkirch. There's an additional line called "nightline" which connects different bars and discos all around Feldkirch. The nightline plies until around 4 a.m. on weekends.  Feldkirch railway station lies on the main railway line through the Vorarlberg, with inter-city services to Zurich and Vienna. There are also local international trains to Buchs via Liechtenstein on the Feldkirch–Buchs railway.

Companies.

, 13,146 employees were employed by 1,464 companies in Feldkirch, including 5 large companies each employing more than 200 people.  The following companies are based in Feldkirch:

Culture and landmarks.

Central Feldkirch.

Feldkirch has one of the best preserved medieval cityscapes of Vorarlberg. The city was built around 1200 at the same time as the Schattenburg and has a geometric grid system. Since around 1500, when the city wall was rebuilt, the city remained unchanged over the centuries.  Since 2015, the Feldkirch Ensemble has been listed in the Austrian List of Cultural Heritage (cultural property protected by the Hague Convention). The city is also a member of the Association of small historic towns, a tourism marketing association.

City fortification.

The streets of the Schlossgraben, Hirschgraben and St. Leonhardsplatz marked the former course of the city wall surrounding the Neustadt area in the 13th century. The wall was largely rebuilt around 1500 and since 1826 in many places abraded.  As long as Feldkirch was surrounded by a city wall and a city moat, one could enter the city only through one of the four gates. These city gates were called Bregenzertor or Nikolaustor, Bludenzertor or Schultor, Milltor or Sautor, and Churertor or Salztor. The last two gates are still standing, the other two were removed together with the city wall at the beginning of the 19th century.

Villas and other residential buildings.

In the 19th century the Feldkirch bourgeoisie built a number of prestigious residential buildings, most of which are still privately owned. The villas were built mostly on the Reichsstraße and here mainly in the area between the Bärenkreuzung and the train station.

Cultural events.

The Poolbar Festival is a modern music and culture festival in Feldkirch. Being held annually between July and August, it attracts around 20,000 visitors featuring music, exhibitions, poetry slams, fashion and an architectural prize. It was first held in 1994 as a cultural summer-academy and is, in organization and implementation of landscape and architecture, very different from other open-air events.  Feldkirch is the home of the Feldkirch Festival, an annual summer festival founded in 2002 by Thomas Hengelbrock and directed since 2007 by Philippe Arlaud.

Climate.

Feldkirch has a humid continental climate ("Dfb").

Feldkirch () is a medieval city in the western Austrian state of Vorarlberg on the border with Switzerland and Liechtenstein. It is the administrative centre of the Feldkirch district. After Dornbirn, it is the second most populous town in Vorarlberg, slightly larger than the state capital of Bregenz. The westernmost point in Austria lies in Feldkirch on the river Rhine, at the northern tripoint between Austria, Switzerland, and Liechtenstein.


Theory.

Suspended particles have an electric surface charge, strongly affected by surface adsorbed species, on which an external electric field exerts an electrostatic Coulomb force. According to the double layer theory, all surface charges in fluids are screened by a diffuse layer of ions, which has the same absolute charge but opposite sign with respect to that of the surface charge. The electric field also exerts a force on the ions in the diffuse layer which has direction opposite to that acting on the surface charge. This latter force is not actually applied to the particle, but to the ions in the diffuse layer located at some distance from the particle surface, and part of it is transferred all the way to the particle surface through viscous stress. This part of the force is also called electrophoretic retardation force. When the electric field is applied and the charged particle to be analyzed is at steady movement through the diffuse layer, the total resulting force is zero :  Considering the drag on the moving particles due to the viscosity of the dispersant, in the case of low Reynolds number and moderate electric field strength "E", the drift velocity of a dispersed particle "v" is simply proportional to the applied field, which leaves the electrophoretic mobility μ defined as:  The most well known and widely used theory of electrophoresis was developed in 1903 by Smoluchowski:  where ε is the dielectric constant of the dispersion medium, ε is the permittivity of free space (C2 N m), η is dynamic viscosity of the dispersion medium (Pa s), and ζ is zeta potential (i.e., the electrokinetic potential of the slipping plane in the double layer, units mV or V).  The Smoluchowski theory is very powerful because it works for dispersed particles of any shape at any concentration. It has limitations on its validity. It follows, for instance, because it does not include Debye length κ (units m). However, Debye length must be important for electrophoresis, as follows immediately from the Figure on the right. Increasing thickness of the double layer (DL) leads to removing the point of retardation force further from the particle surface. The thicker the DL, the smaller the retardation force must be.  Detailed theoretical analysis proved that the Smoluchowski theory is valid only for sufficiently thin DL, when particle radius "a" is much greater than the Debye length:  This model of "thin double layer" offers tremendous simplifications not only for electrophoresis theory but for many other electrokinetic theories. This model is valid for most aqueous systems, where the Debye length is usually only a few nanometers. It only breaks for nano-colloids in solution with ionic strength close to water.  The Smoluchowski theory also neglects the contributions from surface conductivity. This is expressed in modern theory as condition of small Dukhin number:  In the effort of expanding the range of validity of electrophoretic theories, the opposite asymptotic case was considered, when Debye length is larger than particle radius:  Under this condition of a "thick double layer", Hückel predicted the following relation for electrophoretic mobility:  This model can be useful for some nanoparticles and non-polar fluids, where Debye length is much larger than in the usual cases.  There are several analytical theories that incorporate surface conductivity and eliminate the restriction of a small Dukhin number, pioneered by Overbeek. and Booth. Modern, rigorous theories valid for any Zeta potential and often any "aκ" stem mostly from Dukhin–Semenikhin theory.  In the thin double layer limit, these theories confirm the numerical solution to the problem provided by O'Brien and White.

Electrophoresis (from the Greek "ηλεκτροφόρηση" meaning "to bear electrons") is the motion of dispersed particles relative to a fluid under the influence of a spatially uniform electric field. Electrophoresis of positively charged particles (cations) is sometimes called cataphoresis, while electrophoresis of negatively charged particles (anions) is sometimes called anaphoresis.


Hard skills.

Hard skills, also called technical skills, are any skills relating to a specific task or situation. It involves both understanding and proficiency in such specific activity that involves methods, processes, procedures, or techniques. These skills are easily quantifiable unlike soft skills, which are related to one's personality. These are also skills that can be or have been tested and may entail some professional, technical, or academic qualification.

Labor skills.

Skilled workers have long had historical import ("see" Division of labor) as electricians, masons, carpenters, blacksmiths, bakers, brewers, coopers, printers and other occupations that are economically productive. Skilled workers were often politically active through their craft guilds.

Life skills.

An ability and capacity acquired through deliberate, systematic, and sustained effort to smoothly and adaptively carryout complex activities or job functions involving ideas (cognitive skills), things (technical skills), and/or people (interpersonal skills).

People skills.

According to the "Portland Business Journal", people skills are described as:  A British definition is "the ability to communicate effectively with people in a friendly way, especially in business." The term is not listed yet in major US dictionaries.  The term "people skills" is used to include both psychological skills and social skills but is less inclusive than life skills.

Social skills.

Social skill is any skill facilitating interaction and communication with others. Social rules and relations are created, communicated, and changed in verbal and nonverbal ways. The process of learning such skills is called socialization.

Soft skills.

Soft skills are a combination of interpersonal people skills, social skills, communication skills, character traits, attitudes, career attributes and emotional intelligence quotient (EQ) among others.

Hierarchy of Skills.

Skills can be categorized based on the level of expertise and motivation. The highest level of engagement corresponds to the craftsman. About 2% of people reach the highest level.

A skill is the ability to perform an action with determined results often within a given amount of time, energy, or both. Skills can often be divided into domain-general and domain-specific skills. For example, in the domain of work, some general skills would include time management, teamwork and leadership, self-motivation and others, whereas domain-specific skills would be used only for a certain job. Skill usually requires certain environmental stimuli and situations to assess the level of skill being shown and used.


Properties of the imidazole side chain.

The conjugate acid (protonated form) of the imidazole side chain in histidine has a p"K" of approximately 6.0. Thus, at below a pH of 6, the imidazole ring is mostly protonated (as described by the Henderson–Hasselbalch equation). The resulting imidazolium ring bears two NH bonds and has a positive charge. The positive charge is equally distributed between both nitrogens and can be represented with two equally important resonance structures. Above pH 6, one of the two protons is lost. The remaining proton of the imidazole ring can reside on either nitrogen, giving rise to what are known as the N1-H or N3-H tautomers. The N3-H tautomer, shown in the figure above, is protonated on the #3 nitrogen, farther from the amino acid backbone bearing the amino and carboxyl groups, whereas the N1-H tautomer is protonated on the nitrogen nearer the backbone. The imidazole/imidazolium ring of histidine is aromatic at all pH values.  The acid-base properties of the imidazole side chain are relevant to the catalytic mechanism of many enzymes. In catalytic triads, the basic nitrogen of histidine abstract a proton from serine, threonine, or cysteine to activate it as a nucleophile. In a histidine proton shuttle, histidine is used to quickly shuttle protons. It can do this by abstracting a proton with its basic nitrogen to make a positively charged intermediate and then use another molecule, a buffer, to extract the proton from its acidic nitrogen. In carbonic anhydrases, a histidine proton shuttle is utilized to rapidly shuttle protons away from a zinc-bound water molecule to quickly regenerate the active form of the enzyme. In helices E and F of haemoglobin, histidine influences binding of dioxygen as well as carbon monoxide. This interaction enhances the affinity of Fe(II) for O2 but destabilizes the binding of CO, which binds only 200 times stronger in haemoglobin, compared to 20,000 times stronger in free haem.  The tautomerism and acid-base properties of the imidazole side chain has been characterized by N NMR spectroscopy. The two 14N chemical shifts are similar (about 200 ppm, relative to nitric acid on the sigma scale, on which increased shielding corresponds to increased chemical shift). NMR spectral measurements shows that the chemical shift of N1-H drops slightly, whereas the chemical shift of N3-H drops considerably (about 190 vs. 145 ppm). This change indicates that the N1-H tautomer is preferred, possibly due to hydrogen bonding to the neighboring ammonium. The shielding at N3 is substantially reduced due to the second-order paramagnetic effect, which involves a symmetry-allowed interaction between the nitrogen lone pair and the excited π* states of the aromatic ring. At pH > 9, the chemical shifts of N1 and N3 are approximately 185 and 170 ppm.

Ligand.

The imidazole sidechain of histidine commonly serves as a ligand in metalloproteins. One example is the axial base attached to Fe in myoglobin and hemoglobin.

Metabolism.

Biosynthesis.

-Histidine, is an essential amino acid that is not synthesized "de novo" in humans. Humans and other animals must ingest histidine or histidine-containing proteins. The biosynthesis of histidine has been widely studied in prokaryotes such as "E. coli". Histidine synthesis in "E. coli" involves eight gene products (His1, 2, 3, 4, 5, 6, 7, and 8) and it occurs in ten steps. This is possible because a single gene product has the ability to catalyze more than one reaction. For example, as shown in the pathway, His4 catalyzes 4 different steps in the pathway.  Histidine is synthesized from phosphoribosyl pyrophosphate (PRPP), which is made from ribose-5-phosphate by ribose-phosphate diphosphokinase in the pentose phosphate pathway. The first reaction of histidine biosynthesis is the condensation of PRPP and adenosine triphosphate (ATP) by the enzyme ATP-phosphoribosyl transferase. ATP-phosphoribosyl transferase is indicated by His1 in the image. His4 gene product then hydrolyzes the product of the condensation, phosphoribosyl-ATP, producing phosphoribosyl-AMP (PRAMP), which is an irreversible step. His4 then catalyzes the formation of phosphoribosylformiminoAICAR-phosphate, which is then converted to phosphoribulosylformimino-AICAR-P by the His6 gene product. His7 splits phosphoribulosylformimino-AICAR-P to form -erythro-imidazole-glycerol-phosphate. After, His3 forms imidazole acetol-phosphate releasing water. His5 then makes -histidinol-phosphate, which is then hydrolyzed by His2 making histidinol. His4 catalyzes the oxidation of -histidinol to form -histidinal, an amino aldehyde. In the last step, -histidinal is converted to -histidine.  Just like animals and microorganisms, plants need histidine for their growth and development. Microorganisms and plants are similar in that they can synthesize histidine. Both synthesize histidine from the biochemical intermediate phosphoribosyl pyrophosphate. In general, the histidine biosynthesis is very similar in plants and microorganisms.

Regulation of biosynthesis.

This pathway requires energy in order to occur therefore, the presence of ATP activates the first enzyme of the pathway, ATP-phosphoribosyl transferase (shown as His1 in the image on the right). ATP-phosphoribosyl transferase is the rate determining enzyme, which is regulated through feedback inhibition meaning that it is inhibited in the presence of the product, histidine.

Degradation.

Histidine is one of the amino acids that can be converted to intermediates of the tricarboxylic acid (TCA) cycle. Histidine, along with other amino acids such as proline and arginine, takes part in deamination, a process in which its amino group is removed. In prokaryotes, histidine is first converted to urocanate by histidase. Then, urocanase converts urocanate to 4-imidazolone-5-propionate. Imidazolonepropionase catalyzes the reaction to form formiminoglutamate (FIGLU) from 4-imidazolone-5-propionate. The formimino group is transferred to tetrahydrofolate, and the remaining five carbons form glutamate. Overall, these reactions result in the formation of glutamate and ammonia. Glutamate can then be deaminated by glutamate dehydrogenase or transaminated to form α-ketoglutarate.

Requirements.

The Food and Nutrition Board (FNB) of the U.S. Institute of Medicine set Recommended Dietary Allowances (RDAs) for essential amino acids in 2002. For histidine, for adults 19 years and older, 14 mg/kg body weight/day.

External links.

Histidine (symbol His or H) is an α-amino acid that is used in the biosynthesis of proteins. It contains an α-amino group (which is in the protonated –NH form under biological conditions), a carboxylic acid group (which is in the deprotonated –COO form under biological conditions), and an imidazole side chain (which is partially protonated), classifying it as a positively charged amino acid at physiological pH. Initially thought essential only for infants, it has now been shown in longer-term studies to be essential for adults also. It is encoded by the codons CAU and CAC.


Content.

The name is opposed to the 14th century ', which was a forgery drawn up at the behest of the Habsburg duke Rudolf IV of Austria. The recipient of the'was Frederick's paternal uncle, the Babenberg margrave Henry II Jasomirgott.  In addition to the elevation of his margraviate, the emperor determined that inheritance should also be possible through the female line of the ducal family. In the absence of children, the duke was allowed to designate a successor ('). However, this extraordinary privilege was bound to the persons of Henry Jasomirgott and his wife Theodora Komnene (') for life, as both had no children and Henry's brothers Otto I of Freising and Conrad I of Passau had chosen ecclesiastical careers. The emperor reserved for himself the act of enfeoffment but would respect Henry's choice.  The duke's duty to attend the Imperial Diet was limited to those cases where it convened within the Bavarian lands ('), which saved costly traveling throughout the Empire. Also, Austria was henceforth only required to provide troops to the emperor in wars in its vicinity ('). Henry Jasomirgott was obliged to further on discharge his traditional duties as former margrave.

Background.

The issue of the "Privilegium Minus" document is to be seen within the context of the conflict that pitted the Imperial House of Hohenstaufen against the ducal House of Welf in the Holy Roman Empire. In 1138 Emperor Frederick's uncle and predecessor, King Conrad III of Germany had deposed the reluctant Bavarian duke Henry the Proud and had enfeoffed his duchy to the Austrian margrave Henry Jasomirgott. King Conrad died in February 1152 and a few weeks later his nephew Frederick was elected King of the Romans, probably with the support of late Henry the Proud's son Henry the Lion.  The young king and Henry the Lion were cousins through Frederick's mother Judith of Bavaria, sister of Henry the Proud. Frederick prepared for a campaign to Rome to be crowned Holy Roman Emperor and in order to gain military support wished to end the conflict he had inherited from his uncle. He called for a diet at Würzburg —however, Henry Jasomirgott, who anticipated the king's intentions, did not appear under the pretext, that he had not been duly summoned. After several attempts to make an arrangement, Frederick left for Italy and was crowned Emperor on 18 June 1155.  Back in Germany, Frederick resolved upon returning the Duchy of Bavaria to Henry the Lion. He finally was able to hold a secret meeting with Henry Jasomirgott on 5 June 1156 near the Bavarian capital Regensburg. After the conditions were fixed, the emperor called for another diet in Regensburg on 8 September, where the Babenberger officially renounced the Bavarian duchy, which passed to the Welf Henry the Lion. To make up for the loss, Austria with the explicit consent by the Princes of the Holy Roman Empire, led by Duke Vladislaus II of Bohemia, was raised to the status of a duchy. Frederick thereby avoided the degradation of Henry Jasomirgott to the rank of a margrave, which would have lacked any explanation and furthermore would have exposed Henry Jasomirgott to persecution by the Welfs. On the other hand, Henry the Lion only received a diminished Bavarian duchy and Henry Jasomirgott's right of "" would prevent any succession of the House of Welf in Austria. Disappointed, Henry the Lion turned to his Saxon estates in Northern Germany.  Frederick prevailed, settling the long-time conflict, keeping the Welfs covered and securing support by the House of Babenberg. Only much later, the document turned out to be the founding act for what was to become a nation. 1156 is therefore sometimes given as Austria's date of independence, which it gained from Bavaria.

Application.

13th century succession crisis.

Because the Babenberg Austria was inheritable by female lines, two rival candidates emerged after the last male Babenberg Frederick II, Duke of Austria, Styria and Carinthia died in 1246.

18th century succession crisis.

The Pragmatic Sanction of 1713 was partially based on provisions of the "Privilegium Minus" of Austria. Although not given to the Habsburgs but to the Babenbergs, it anyway allowed female heirs to succeed in Austria, and it designated to the Duke the right to name a successor in absence of heirs. It led to the War of Austrian Succession.

Further reading.

Blackwell, Basil, "Source for the History of Medieval Europe" (1966), pp. 160–164.

The is the denotation of a deed issued by Emperor Frederick Barbarossa on 17 September 1156. It included the elevation of the Bavarian frontier march of Austria ("") to a duchy, which was given as an inheritable fief to the House of Babenberg.


History.

Commander of the Praetorian Guard.

Under the empire the praetorians or imperial guards were commanded by one, two, or even three praefects (praefecti praetorio), who were chosen by the emperor from among the equites and held office at his pleasure. From the time of Alexander Severus the post was open to senators also, and if an equestrian was appointed he was at the same time raised to the senate. Down to the time of Constantine, who deprived the office of its military character, the prefecture of the guards was regularly held by tried soldiers, often by men who had fought their way up from the ranks. In course of time the command seems to have been enlarged so as to include all the troops in Italy except the corps commanded by the city praefect ("cohortes urbanae").  The special position of the praetorians made them a power in their own right in the Roman state, and their prefect, the "praefectus praetorio", soon became one of the more powerful men in this society. The emperors tried to flatter and control the praetorians, but they staged many coups d'état and contributed to a rapid rate of turnover in the imperial succession. The praetorians thus came to destabilize the Roman state, contrary to their purpose. The praetorian prefect became a major administrative figure in the later empire, when the post combined in one individual the duties of an imperial chief of staff with direct command over the guard also. Diocletian greatly reduced the power of these prefects as part of his sweeping reform of the empire's administrative and military structures.

Transformation to administrator.

In addition to his military functions, the praetorian prefect came to acquire jurisdiction over criminal affairs, which he exercised not as the delegate but as the representative of the emperor. By the time of Diocletian he had become a kind of grand-vizier as the emperor's vice-regent and 'prime minister.' Constantine removed active military command in 312. The prefect remained as chief quarter-master general responsible for the logistical supply of the army. The prefect was the chief financial officer whose office drew up the global imperial budget. His office drew up the state liturgical obligations laid on the richer inhabitants of the Empire. He ceased to be head of administration which had to be shared with the master of the offices attached to the palace. Constantine in 331 confirmed that from the sentence of the praetorian praefect there should be no appeal. A similar jurisdiction in civil cases was acquired by him not later than the time of Septimius Severus. Hence a knowledge of law became a qualification for the post, which under Marcus Aurelius and Commodus, but especially from the time of Severus, was held by the first jurists of the age, (e.g. Papinian, Ulpian, Paulus) and, under Justinianus, John the Cappadocian, while the military qualification fell more and more into the background.  The tetrarchy reform of Diocletian (c. 296) multiplied the office: there was a praetorian prefect as chief of staff (military and administrative)—rather than commander of the guard—for each of the two Augusti, but not for the two Caesars. Each praetorian prefect oversaw one of the four quarters created by Diocletian, which became regional praetorian prefectures for the young sons of Constantine ca 330 A.D. From 395 there two imperial courts, at Rome (later Ravenna) and Constantinople, but the four prefectures remained as the highest level of administrative division, in charge of several dioceses (groups of Roman provinces), each of which was headed by a Vicarius. Under Constantine I, the institution of the magister militum deprived the praetorian prefecture altogether of its military character but left it the highest civil office of the empire.

Germanic era.

The office was among the many maintained after the Western Roman Empire had succumbed to the Germanic invasion in Italy, notably at the royal court of the Ostrogothic king Theoderic the Great, who as a nominal subject of Constantinople retained the Roman-era administration intact.

List of known prefects of the Praetorian Guard.

The following is a list of all known prefects of the Praetorian Guard, from the establishment of the post in 2 BC by Augustus until the abolishment of the Guard in 314. The list is presumed to be incomplete due to the lack of sources documenting the exact number of persons who held the post, what their names were and what the length of their tenure was. Likewise, the Praetorians were sometimes commanded by a single prefect, as was the case with for example Sejanus or Burrus, but more often, the emperor appointed two commanders, who shared joint leadership. Overlapping terms on the list indicate dual command.

See also.

For praetorian prefects after the reformation of the office by emperor Constantine I, see:

The praetorian prefect (, ) was a high office in the Roman Empire. Originating as the commander of the Praetorian Guard, the office gradually acquired extensive legal and administrative functions, with its holders becoming the Emperor's chief aides. Under Constantine I, the office was much reduced in power and transformed into a purely civilian administrative post, while under his successors, territorially-defined praetorian prefectures emerged as the highest-level administrative division of the Empire. The prefects again functioned as the chief ministers of the state, with many laws addressed to them by name. In this role, praetorian prefects continued to be appointed by the Eastern Roman Empire (and the Ostrogothic Kingdom) until the reign of Heraclius in the 7th century AD, when wide-ranging reforms reduced their power and converted them to mere overseers of provincial administration. The last traces of the prefecture disappeared in the Byzantine Empire by the 840s.


History.

Battle of Alesia.

Alesia is best known for being the site of the decisive Battle of Alesia in 52 BC that marked the defeat of the Gauls under Vercingetorix by the Romans under Julius Caesar. Caesar described the battle in detail in his "" (Book VII, 69–90). The battle's outcome determined the fate of all of Gaul: in winning the battle, the Romans won both the Gallic Wars and dominion over Gaul.  The enormous measures taken during the battle were impressive: in only six weeks, Caesar's troops built a ring of fortifications long ("circumvallation") around Alesia and an additional ring long ("contravallation") around that to stop reinforcements (around 250,000 men according to Caesar) from reaching the Gauls.

Roman.

After being conquered by Caesar, Alesia became a Gallo-Roman town. It featured a town centre with monumental buildings such as temples and a forum. There was also a theatre.

Geography and location.

For a long time after the abandonment of the Roman town, the location of Alesia and thus the site of the important battle was unknown and subject to speculation. In the 19th century, Emperor Napoleon III developed an interest in the location of this crucial battle in pre-French history. He was writing a biography of Caesar and saw the command of Vercingetorix over all Gaulish armies as a symbol of the French nation. At the same time he realized that the future French nation was heavily influenced by the Roman victory and centuries of rule over Gaul.  In 1838, a find with the inscription: ", had been discovered near Alise-Sainte-Reine in the department near Dijon. Napoleon ordered an archaeological excavation by around. These excavations in 1861–65 concentrated on the vast Roman siege lines and indicated that the historical Alesia was indeed located there.  The was located on a plateau of, around above the valley floor, surrounded by steep cliffs in every direction except at the eastern and western extremities. It was protected by a wall (") enclosing an area of up to 140 hectares, pierced by at least two pincer gates and in 52 BC it possibly had a population of 80,000 including refugees and men under the command of Vercingetorix.  Later archaeological analysis at has corroborated the described siege in detail. The remains of siege rings said to match Caesar’s descriptions have been identified by archaeologists using aerial photography (e.g. by ). Franco-German excavations led by and in 1991–97 confirmed these findings and effectively ended the long debate among archaeologists about the location of Alesia.

Alternative theories on Alesia’s location.

There have been other theories about Alesia's location that claimed it was in or around in Jura. In the 1960s, a French archaeologist,, proposed that the location of Alesia is at in, at the gate of the Jura mountains—a place that better suits the descriptions in Caesar's Gallic Wars—and indeed, Roman fortifications have been found at that site. In total, around 40 towns and other locations have claimed to be the site of Alesia.

Today.

Part of the area has become the "". Not much of the Gallic is visible today, except for some remains of a rampart. Most of the ruins date to the town’s Roman period.  A large copper statue of Vercingetorix, made in 1865 by stands at the western end of the plateau.  The uncertainty surrounding Alesia's location is humorously parodied in the Asterix comic book "Asterix and the Chieftain's Shield", in which, in this case because of Gaulish pride, characters repeatedly and vehemently deny that they know its location: "I don't know where Alesia is! No one knows where Alesia is!".

Alesia was the capital of the Mandubii, one of the Gallic tribes allied with the Aedui. The Celtic was conquered by Julius Caesar during the Gallic Wars and afterwards became a Gallo-Roman town. Modern understanding of its location was controversial for a long time; however, it is now thought to have been located on, near in Burgundy, France.


Range and distribution.

Two allopatric populations (subspecies) occur in Africa. "O. m. virgatus" occurs from Ethiopia and southern Sudan to Tanzania. The other population, "O. m. megalotis", occurs in the southern part of Africa. It ranges from southern Zambia and Angola to South Africa, and extends as far east as Mozambique and Zimbabwe, spreading into the Cape Peninsula and toward Cape Agulhas. Home ranges vary in size from 0.3 to 3.5 km.

Habitat.

The bat-eared fox commonly inhabits short grasslands, as well as the more arid regions of the savanna. It prefers bare ground and areas where grass is kept short by grazing ungulates. It tends to hunt in these short grass and low shrub habitats. However, it does venture into areas with tall grasses and thick shrubs to hide when threatened.  In addition to raising their young in dens, bat-eared foxes use self-dug dens for shelter from extreme temperatures and winds. They also lie under acacia trees in South Africa to seek shade during the day.

Diet.

The bat-eared fox is predominantly an insectivore that uses its large ears to locate its prey. About 80–90% of their diet is harvester termites ("Hodotermes mossambicus"). When this particular species of termite is not available, they feed on other species of termites and have also been observed consuming other arthropods such as ants, beetles, crickets, grasshoppers, millipedes, moths, scorpions, spiders, and rarely birds, small mammals, reptiles, and fungi (the desert truffle "Kalaharituber pfeilii"). The insects they eat fulfill the majority of their water intake needs. The bat-eared fox refuses to feed on snouted harvester termites, likely because it is not adapted to tolerate termites' chemical defense.

Dentition.

The teeth of the bat-eared fox are much smaller and reduced in shearing surface formation than teeth of other canid species. This is an adaptation to its insectivorous diet. Due to its unusual teeth, the bat-eared fox was once considered as a distinct subfamily of canids (Otocyoninae). However, according to more recent examinations, it is more closely related to the true foxes of the genus "Vulpes". Other research places the genus as an outgroup which is not very closely related to foxes. The bat-eared fox is an old species that was widely distributed in the Pleistocene era. The teeth are not the bat-eared fox's only morphological adaptation for its diet. The lower jaw has a step-like protrusion called the subangular process, which anchors the large muscle to allow for rapid chewing. The digastric muscle is also modified to open and close the jaw five times per second.

Foraging.

Bat-eared foxes usually hunt in groups, mostly in pairs and groups of three. Individuals forage alone after family groups break in June or July and during the months after cub birth. Prey is located primarily by auditory means, rather than by smell or sight. Foraging patterns vary between seasons and coincide with termite availability. In the midsummer, individuals begin foraging at sunset, continuing throughout the night, and fading into the early morning. Foraging is almost exclusively diurnal during the winter it usually occurs in patches, which match the clumped prey resources, such as termite colonies, that also occur in patches. Groups are able to forage on clumps of prey in patches because they do not fight each other for food due to their degree of sociality and lack of territoriality.

Behavior.

In the more northern areas of its range (around Serengeti), they are nocturnal 85% of the time. However, around South Africa, they are nocturnal only in the summer and diurnal during the winter.  Bat-eared foxes are highly social animals. They often live in pairs or groups of up to 15 individuals, and home ranges of groups either overlap substantially or very little. Individuals forage, play, and rest together in a group, which helps in protection against predators. Social grooming occurs throughout the year, mostly between mature adults, but also between young adults and mature adults.  Visual displays are very important in communication among bat-eared foxes. When they are looking intently at something, the head is held high, eyes are open, ears are erect and facing forward, and the mouth is closed. When an individual is in threat or showing submission, the ears are pulled back and lying against the head and the head is low. The tail also plays a role in communication. When an individual is asserting dominance or aggression, feeling threatened, playing, or being sexually aroused, the tail is arched in an inverted U shape. Individuals can also use piloerection, which occurs when individual hairs are standing straight, to make it appear larger when faced with extreme threat. When running, chasing, or fleeing, the tail is straight and horizontal. The bat-eared fox can recognize individuals up to 30 m away. The recognition process has three steps: First they ignore the individual, then they stare intently, and finally they either approach or attack without displays. When greeting another, the approaching individual shows symbolic submission which is received by the other individual with a high head and tail down. Few vocalizations are used for communication, but contact calls and warning calls are used, mostly during the winter. Glandular secretions and scratching, other than for digging, are absent in communication.

Reproduction.

The bat-eared fox is predominantly socially monogamous, although it has been observed in polygynous groups. In contrast to other canids, the bat-eared fox has a reversal in parental roles, with the male taking on the majority of the parental care behavior. Gestation lasts for 60–70 days and females give birth to litters consisting of one to six kits. Beyond lactation, which lasts 14 to 15 weeks, males take over grooming, defending, huddling, chaperoning, and carrying the young between den sites. Additionally, male care and den attendance rates have been shown to have a direct correlation with cub survival rates. The female forages for food, which she uses to maintain milk production, on which the pups heavily depend. Food foraged by the female is not brought back to the pups or regurgitated to feed the pups.  Pups in the Kalahari region are born September–November and those in the Botswana region are born October–December. Young bat-eared foxes disperse and leave their family groups at 5–6 months old and reach sexual maturity at 8–9 months.

Conservation threats.

The bat-eared fox has some commercial use for humans. They are important for harvester termite population control, as the termites are considered pests. They have also been hunted for their fur by Botswana natives. Additional threats to populations include disease and drought that can harm populations of prey; however, no major threats to bat-eared fox populations exist.

The bat-eared fox ("Otocyon megalotis") is a species of fox found on the African savanna, named for its large ears, which are used for thermoregulation. Fossil records show this canid first appeared during the middle Pleistocene, about 800,000 years ago. It is considered a basal canid species, resembling ancestral forms of the family, It has also been called a Sub-Saharan African version of a fennec fox due to their huge ears.


Name.

In ancient times the island was called "Pora pora mai te pora", meaning "created by the gods" in the local Tahitian dialect. This was often abbreviated "Pora Pora" meaning simply "first born". Because of ambiguities in the phonemes of the Tahitian language, this could also be pronounced "Bola Bola" or "Bora Bora". When explorer Jacob Roggeveen first landed on the island, he and his crew adopted the name "Bora Bora" which has stood ever since.

History.

The island was inhabited by Polynesian settlers around the 4th century The first European sighting was made by Jakob Roggeveen in 1722.  James Cook sighted the island on 29 July 1769, using a Tahitian navigator, Tupaia. The London Missionary Society arrived in 1820 and founded a Protestant church in 1890. Bora Bora was an independent kingdom until 1888 when its last queen Teriimaevarua III was forced to abdicate by the French who annexed the island as a colony.

World War II.

In World War II the United States chose Bora Bora as a South Pacific military supply base, and an oil depot, airstrip, seaplane base, and defensive fortifications were constructed. Known as "Operation Bobcat", it maintained a supply force of nine ships, 20,000 tons of equipment and nearly 7,000 men.  At least eight 7"/44 caliber guns, operated by elements of the 13th Coast Artillery Regiment (later the 276th Coast Artillery Battalion), were set up at strategic points around the island to protect it against potential military attack. Eight of these guns remain in the area.  However, the island saw no combat as the American presence on Bora Bora went uncontested over the course of the war. The base was officially closed on 2 June 1946. The World War II airstrip was never able to accommodate large aircraft, but it nonetheless was French Polynesia's only international airport until Faa'a International Airport opened next to Papeete, Tahiti, in 1960.

Tourism.

The island's economy is driven almost solely by tourism. Several resorts have been built on the "motu" (small islands, from Tahitian) surrounding the lagoon. Hotel Bora Bora opened in 1961, and nine years later built the first over-the-water bungalows on stilts over the lagoon. Today, over-water bungalows are a standard feature of most Bora Bora resorts. The quality of those bungalows ranges from comparably cheap, basic accommodations to very luxurious and expensive.  Most of the tourist destinations are aqua-centric; however, it is possible to visit attractions on land such as WWII cannons. Air Tahiti has five or six flights daily to the Bora Bora Airport on Motu Mute from Tahiti (as well as from other islands). Public transport on the island is nonexistent so rental cars and bicycles are the recommended methods of transport. There are also small, two-seater buggies for hire in Vaitape. It is possible to rent a motorboat to explore the lagoon.  Snorkeling and scuba diving in and around the lagoon of Bora Bora are popular activities. Many species of sharks and rays inhabit the surrounding body of water. There are a few dive operators on the island offering manta ray dives and also shark-feeding dives. Sharks living in the island's lagoon are not considered to be dangerous to people.  In addition to the existing islands of Bora Bora, the new manmade island of Motu Marfo has been added in the northeastern corner of the lagoon on the property of the St. Regis Resort.

Climate.

Bora Bora has a tropical monsoon climate. Temperatures are relatively consistent throughout the year, with hot days and warm nights. The dry season lasts from June to October yet precipitation is still observed throughout this period.

Endemic gastropod ecology and decline.

Forest habitats on Bora Bora on the slopes of Mount Otemanu are quite diverse in gastropod life in comparison to other islands. Several species of endemic or native species existed in great numbers until relatively recently during the introductions of "Lissachatina", "Euglandina", and various flatworms which decimated populations of "Partula lutea" (an endemic partulid species that became extinct in the late 1990s), "Samoana attenuata" (a species once native to Bora Bora but later not found in surveys of the island), and "Mautodontha boraborensis" (a critically endangered species as of 1996 but most likely extinct, as it was last seen in the 1880s). The above listed native and endemic species were mostly restricted to virgin forest, and the only species that remain common (perhaps even extant) are several subulinids and tornatellinids among others, including "Orobophana pacifica ("a helicinid")."

Bora Bora (French: "Bora-Bora"; Tahitian: "Pora Pora") is a island group in the Leeward group in the western part of the Society Islands of French Polynesia, an overseas collectivity of the French Republic in the Pacific Ocean. The main island, located about northwest of Papeete, is surrounded by a lagoon and a barrier reef. In the center of the island are the remnants of an extinct volcano rising to two peaks, Mount Pahia and Mount Otemanu, the highest point at. It is part of the commune of Bora-Bora, which also includes the atoll of Tūpai.


Bird migration.

The Strait of Messina is a focal point in the migrations of birds every year, who mainly cross the strait to reach their breeding grounds in northern Europe. Due to this form of bottleneck more than 300 species are recorded in the area, which is a major European hot spot for raptors, with a record of 35.000 in a spring.  Among them the European honey buzzard and the marsh harrier are the most frequent, species like Bonelli's eagle and Egyptian vulture are less frequent but regular. In the coastal salt lakes of the Strait of Messina species like glossy ibis, flamingos and black-winged stilt stop to rest. The site is also favorable for observing storks. The Monte Dinnammare and the other Peloritani mountains overlooking the Strait are a natural theatre for birdwatching.

Marine life.

Due to its unique hydrogeological conditions the Strait of Messina has high levels of biodiversity and multiple endemic species. In its waters there is a strong presence of deep sea fish like the Sloane's viperfish which, due to the particular and peculiar currents of the strait, are occasionally found stranded on the shore at sunrise. The strait is also an important point of migration of many species of fish in the Mediterranean Sea.

Transportation.

A ferry service connects Messina on Sicily with the mainland at Villa San Giovanni, which lies several kilometers north of the large city of Reggio Calabria; the ferries hold the cars (carriages) of the mainline train service between Palermo and Naples. There is also a hydrofoil service between Messina and Reggio Calabria.  For decades, the possibility of building a bridge across the Messina Strait has been under discussion. In 2006, under Prime Minister Romano Prodi the project was cancelled. On 6 March 2009, however, as part of a massive new public works program, Silvio Berlusconi's government announced that plans to construct the Messina Bridge had been fully revived, pledging €1.3 billion as a contribution to its estimated cost of €6.1 billion Some 3.3 km long and 60 m wide, the bridge would be supported by two 382 m pillars, each higher than the Empire State Building, and accommodate six freeway lanes, a railway (for up to 200 trains a day), and two walkways.  Supporters perceive the bridge as a huge job-creation scheme and a boost for tourism to the island. Opponents see it as an ecological disaster, a structure at risk due to especially strong winds and earthquakes (the area having an intense seismic record), and a boon for Sicilian and Calabrian organized crime. Berlusconi claimed in 2009 that work would be completed by 2016 although in February 2013, the project was cancelled again.

The Strait of Messina () is a narrow strait between the eastern tip of Sicily (Punta del Faro) and the western tip of Calabria (Punta Pezzo) in the south of Italy. It connects the Tyrrhenian Sea to the north with the Ionian Sea to the south, within the central Mediterranean. At its narrowest point, between Torre Faro and Villa San Giovanni, it is wide. At the town of Messina it is wide. The strait's maximum depth is about.


Life.

He was born in Graz, Styria, his cousin Guido Starhemberg also became a famous soldier and fought as an adjutant at his side. Ernst Rüdiger von Starhemberg fought in the 1660s under Imperial Lieutenant general Raimondo Montecuccoli against French and Ottoman forces.  In 1683 he was military commander of the city of Vienna, with fewer than 20,000 men to oppose about 120,000 besieging Ottomans. On 15 July 1683 Starhemberg refused an offer by the Turkish commander Kara Mustafa Pasha to capitulate, counting on the speedy arrival of an Imperial army, sent by the Habsburg emperor Leopold I who had fled his residence, and the strength of city walls which had been fortified after the first Ottoman Siege of Vienna in 1529.  When after two months the relief army under the command of Polish king Jan Sobieski arrived in the first half of September, Vienna was on the brink of collapse. Its walls were breached by Turkish sappers who had tunnelled under the walls, packed the tunnels with gunpowder, and detonated the explosive charges. Finally, on 12 September, 80,000 Polish, Venetian, Bavarian, and Saxon troops attacked the Turks and were able to defeat them in the Battle on the Kahlenberg.  Ernst Rüdiger von Starhemberg was promoted to the rank of a field marshal by the Emperor, recognizing Starhemberg's action in saving the imperial capital. He was also made a minister of the state. Going after the retiring Ottoman troops, Starhemberg was severely wounded in 1686 during the Siege of Buda by a shot in his left hand and had to abandon his command. In 1691 he was made President of the Hofkriegsrat and was responsible for the organisation of the Habsburg army.  Starhemberg died at Vösendorf on 4 January 1701, aged 62. His tomb (by Joseph Emanuel Fischer von Erlach) is situated in the Vienna Schottenkirche.  The later Austrian politician Ernst Rüdiger Starhemberg (1899-1956) was a collateral descendant.

Legacy.

Later generations have idealized Starhemberg as saviour of the Western world and culture. By order of Emperor Franz Joseph I of Austria, a statue was erected in his honour in 1872 at the Heeresgeschichtliches Museum in Vienna, where the Battle of Vienna is thoroughly documented, with Starhemberg's épée and armour on display.

Sources.

Adolf Schinzl: Starhemberg, Ernst Rüdiger Graf von. In: Allgemeine Deutsche Biographie (ADB). Band 35, Duncker & Humblot, Leipzig 1893, S. 468–470. Die Türkenkriege, Angriff auf das Abendland (= G/Geschichte; Heft Juni 2007)

Count Ernst Rüdiger von Starhemberg (12 January 1638 – 4 January 1701) was military governor of Vienna from 1680, the city's defender during the Battle of Vienna in 1683, Imperial general during the Great Turkish War, and President of the Hofkriegsrat.