Discovery.

Members of the Hsp70 family are very strongly upregulated by heat stress and toxic chemicals, particularly heavy metals such as arsenic, cadmium, copper, mercury, etc. Hsp70 was originally discovered by FM Ritossa in the 1960s when a lab worker accidentally boosted the incubation temperature of Drosophila (fruit flies). When examining the chromosomes, Ritossa found a "puffing pattern" that indicated the elevated gene transcription of an unknown protein. This was later described as the "Heat Shock Response" and the proteins were termed the "Heat Shock Proteins" (Hsps).

Structure.

The Hsp70 proteins have three major functional domains:

Function and regulation.

The Hsp70 system interacts with extended peptide segments of proteins as well as partially folded proteins to cause aggregation of proteins in key pathways to deregulate activity When not interacting with a substrate peptide, Hsp70 is usually in an ATP bound state. Hsp70 by itself is characterized by a very weak ATPase activity, such that spontaneous hydrolysis will not occur for many minutes. As newly synthesized proteins emerge from the ribosomes, the substrate binding domain of Hsp70 recognizes sequences of hydrophobic amino acid residues, and interacts with them. This spontaneous interaction is reversible, and in the ATP bound state Hsp70 may relatively freely bind and release peptides. However, the presence of a peptide in the binding domain stimulates the ATPase activity of Hsp70, increasing its normally slow rate of ATP hydrolysis. When ATP is hydrolyzed to ADP the binding pocket of Hsp70 closes, tightly binding the now-trapped peptide chain. Further speeding ATP hydrolysis are the so-called J-domain cochaperones: primarily Hsp40 in eukaryotes, and DnaJ in prokaryotes. These cochaperones dramatically increase the ATPase activity of Hsp70 in the presence of interacting peptides.  By binding tightly to partially synthesized peptide sequences (incomplete proteins), Hsp70 prevents them from aggregating and being rendered nonfunctional. Once the entire protein is synthesized, a nucleotide exchange factor (prokaryotic GrpE, eukaryotic BAG1 and HspBP1 are among those which have been identified) stimulates the release of ADP and binding of fresh ATP, opening the binding pocket. The protein is then free to fold on its own, or to be transferred to other chaperones for further processing. HOP (the Hsp70/Hsp90 Organizing Protein) can bind to both Hsp70 and Hsp90 at the same time, and mediates the transfer of peptides from Hsp70 to Hsp90.  Hsp70 also aids in transmembrane transport of proteins, by stabilizing them in a partially folded state. It is also known to be phosphorylated which regulates several of its functions.  Hsp70 proteins can act to protect cells from thermal or oxidative stress. These stresses normally act to damage proteins, causing partial unfolding and possible aggregation. By temporarily binding to hydrophobic residues exposed by stress, Hsp70 prevents these partially denatured proteins from aggregating, and inhibits them from refolding. Low ATP is characteristic of heat shock and sustained binding is seen as aggregation suppression, while recovery from heat shock involves substrate binding and nucleotide cycling. In a thermophile anaerobe ("Thermotoga maritima") the Hsp70 demonstrates redox sensitive binding to model peptides, suggesting a second mode of binding regulation based on oxidative stress.  Hsp70 seems to be able to participate in disposal of damaged or defective proteins. Interaction with CHIP ("C"arboxyl-terminus of "H"sp70 "I"nteracting "P"rotein)–an E3 ubiquitin ligase–allows Hsp70 to pass proteins to the cell's ubiquitination and proteolysis pathways.  Finally, in addition to improving overall protein integrity, Hsp70 directly inhibits apoptosis. One hallmark of apoptosis is the release of cytochrome c, which then recruits Apaf-1 and dATP/ATP into an apoptosome complex. This complex then cleaves procaspase-9, activating caspase-9 and eventually inducing apoptosis via caspase-3 activation. Hsp70 inhibits this process by blocking the recruitment of procaspase-9 to the Apaf-1/dATP/cytochrome c apoptosome complex. It does not bind directly to the procaspase-9 binding site, but likely induces a conformational change that renders procaspase-9 binding less favorable. Hsp70 is shown to interact with Endoplasmic reticulum stress sensor protein IRE1alpha thereby protecting the cells from ER stress - induced apoptosis. This interaction prolonged the splicing of XBP-1 mRNA thereby inducing transcriptional upregulation of targets of spliced XBP-1 like EDEM1, ERdj4 and P58IPK rescuing the cells from apoptosis. Other studies suggest that Hsp70 may play an anti-apoptotic role at other steps, but is not involved in Fas-ligand-mediated apoptosis (although Hsp 27 is). Therefore, Hsp70 not only saves important components of the cell (the proteins) but also directly saves the cell as a whole. Considering that stress-response proteins (like Hsp70) evolved before apoptotic machinery, Hsp70's direct role in inhibiting apoptosis provides an interesting evolutionary picture of how more recent (apoptotic) machinery accommodated previous machinery (Hsps), thus aligning the improved integrity of a cell's proteins with the improved chances of that particular cell's survival.

Cancer.

Hsp70 is overexpressed in malignant melanoma and underexpressed in renal cell cancer.

Expression in skin tissue.

Both HSP70 and HSP47 were shown to be expressed in dermis and epidermis following laser irradiation, and the spatial and temporal changes in HSP expression patterns define the laser-induced thermal damage zone and the process of healing in tissues. HSP70 may define biochemically the thermal damage zone in which cells are targeted for destruction, and HSP47 may illustrate the process of recovery from thermally induced damage.

Family members.

Prokaryotes express three Hsp70 proteins: DnaK, HscA (Hsc66), and HscC (Hsc62).  Eukaryotic organisms express several slightly different Hsp70 proteins. All share the common domain structure, but each has a unique pattern of expression or subcellular localization. These are, among others:  The following is a list of human Hsp70 genes and their corresponding proteins:

Hsp110.

The Hsp70 superfamily also includes a family of Hsp110/Grp170 (Sse) proteins, which are larger proteins related to Hsp70. The Hsp110 family of proteins have divergent functions: yeast Sse1p has little ATPase activity but is a chaperone on its own as well as a nucleotide exchange factor for Hsp70, while the closely related Sse2p has little unfoldase activity.  The following is a list of currently named human HSP110 genes. HSPH2-4 are proposed names and the current name is linked:

The 70 kilodalton heat shock proteins (Hsp70s or DnaK) are a family of conserved ubiquitously expressed heat shock proteins. Proteins with similar structure exist in virtually all living organisms. The Hsp70s are an important part of the cell's machinery for protein folding, and help to protect cells from stress.

Hsp70 ("heat shock protein 70") je jeden z nejběžnějších proteinů teplotního šoku pracující jako chaperon. Vyskytuje se v určité podobě nejen u eukaryot včetně člověka, ale také u bakterií a archebakterií, ačkoliv se u nich obvykle označují DnaK. V eukaryotických genomech sídlí celá rodina Hsp70 genů, i kvasinky mají 14 genů pro Hsp70.


Sawmill process.

A sawmill's basic operation is much like those of hundreds of years ago; a log enters on one end and dimensional lumber exits on the other end.

Pre-Industrial Revolution.

The Hierapolis sawmill, a water-powered stone sawmill at Hierapolis, Asia Minor (modern-day Turkey, then part of the Roman Empire), dating to the second half of the 3rd century, is the earliest known sawmill. It also incorporates a crank and connecting rod mechanism.  Water-powered stone sawmills working with cranks and connecting rods, but without gear train, are archaeologically attested for the 6th century at the Byzantine cities Gerasa (in Asia Minor) and Ephesus (in Syria).  The earliest literary reference to a working sawmill comes from a Roman poet, Ausonius, who wrote a topographical poem about the river Moselle in Germany in the late 4th century AD. At one point in the poem he describes the shrieking sound of a watermill cutting marble. Marble sawmills also seem to be indicated by the Christian saint Gregory of Nyssa from Anatolia around 370/390 AD, demonstrating a diversified use of water-power in many parts of the Roman Empire.  By the 11th century, hydropowered sawmills were in widespread use in the medieval Islamic world, from Islamic Spain and North Africa in the west to Central Asia in the east.  Sawmills later became widespread in medieval Europe, as one was sketched by Villard de Honnecourt in c. 1225-1235. They are claimed to have been introduced to Madeira following its discovery in c. 1420 and spread widely in Europe in the 16th century.  Prior to the invention of the sawmill, boards were rived (split) and planed, or more often sawn by two men with a whipsaw, using saddleblocks to hold the log, and a saw pit for the pitman who worked below. Sawing was slow, and required strong and hearty men. The topsawer had to be the stronger of the two because the saw was pulled in turn by each man, and the lower had the advantage of gravity. The topsawyer also had to guide the saw so that the board was of even thickness. This was often done by following a chalkline.  Early sawmills simply adapted the whipsaw to mechanical power, generally driven by a water wheel to speed up the process. The circular motion of the wheel was changed to back-and-forth motion of the saw blade by a connecting rod known as a "pitman arm" (thus introducing a term used in many mechanical applications).  Generally, only the saw was powered, and the logs had to be loaded and moved by hand. An early improvement was the development of a movable carriage, also water powered, to move the log steadily through the saw blade.  A type of sawmill without a crank is known from Germany called "knock and drop" or simply "drop" -mills. In these drop sawmills, the frame carrying the saw blade is knocked upwards by cams as the shaft turns. These cams are let into the shaft on which the waterwheel sits. When the frame carrying the saw blade is in the topmost position it drops by its own weight, making a loud knocking noise, and in so doing it cuts the trunk.  A small mill such as this would be the center of many rural communities in wood-exporting regions such as the Baltic countries and Canada. The output of such mills would be quite low, perhaps only 500 boards per day. They would also generally only operate during the winter, the peak logging season.  In the United States, the sawmill was introduced soon after the colonisation of Virginia by recruiting skilled men from Hamburg. Later the metal parts were obtained from the Netherlands, where the technology was far ahead of that in England, where the sawmill remained largely unknown until the late 18th century. The arrival of a sawmill was a large and stimulative step in the growth of a frontier community.

Industrial Revolution.

Early mills had been taken to the forest, where a temporary shelter was built, and the logs were skidded to the nearby mill by horse or ox teams, often when there was some snow to provide lubrication. As mills grew larger, they were usually established in more permanent facilities on a river, and the logs were floated down to them by log drivers. Sawmills built on navigable rivers, lakes, or estuaries were called cargo mills because of the availability of ships transporting cargoes of logs to the sawmill and cargoes of lumber from the sawmill.  The next improvement was the use of circular saw blades, perhaps invented in England in the late 18th century, but perhaps in 17th-century Holland, the Netherlands. Soon thereafter, millers used gangsaws, which added additional blades so that a log would be reduced to boards in one quick step. Circular saw blades were extremely expensive and highly subject to damage by overheating or dirty logs. A new kind of technician arose, the sawfiler. Sawfilers were highly skilled in metalworking. Their main job was to "set" and sharpen teeth. The craft also involved learning how to "hammer" a saw, whereby a saw is deformed with a hammer and anvil to counteract the forces of heat and cutting. Modern circular saw blades have replaceable teeth, but still need to be hammered.  The introduction of steam power in the 19th century created many new possibilities for mills. Availability of railroad transportation for logs and lumber encouraged building of rail mills away from navigable water. Steam powered sawmills could be far more mechanized. Scrap lumber from the mill provided a ready fuel source for firing the boiler. Efficiency was increased, but the capital cost of a new mill increased dramatically as well.  In addition, the use of steam or gasoline-powered traction engines also allowed the entire sawmill to be mobile.  By 1900, the largest sawmill in the world was operated by the Atlantic Lumber Company in Georgetown, South Carolina, using logs floated down the Pee Dee River from as far as the edge of the Appalachian Mountains in North Carolina.  A restoration project for Sturgeon's Mill in Northern California is underway, restoring one of the last steam-powered lumber mills still using its original equipment.

Current trends.

In the twentieth century the introduction of electricity and high technology furthered this process, and now most sawmills are massive and expensive facilities in which most aspects of the work is computerized. The cost of a new facility with per day capacity is up to CAN$120,000,000. A modern operation will produce between annually.  Small gasoline-powered sawmills run by local entrepreneurs served many communities in the early twentieth century, and specialty markets still today.  A trend is the small portable sawmill for personal or even professional use. Many different models have emerged with different designs and functions. They are especially suitable for producing limited volumes of boards, or specialty milling such as oversized timber. Portable sawmills have gained popularity for the convenience of bringing the sawmill to the logs and milling lumber in remote locations. Some remote communities that have experienced natural disasters have used portable sawmills to rebuild their communities out of the fallen trees.  Technology has changed sawmill operations significantly in recent years, emphasizing increasing profits through waste minimization and increased energy efficiency as well as improving operator safety. The once-ubiquitous rusty, steel conical sawdust burners have for the most part vanished, as the sawdust and other mill waste is now processed into particleboard and related products, or used to heat wood-drying kilns. Co-generation facilities will produce power for the operation and may also feed superfluous energy onto the grid. While the bark may be ground for landscaping barkdust, it may also be burned for heat. Sawdust may make particle board or be pressed into wood pellets for pellet stoves. The larger pieces of wood that won't make lumber are chipped into wood chips and provide a source of supply for paper mills. Wood by-products of the mills will also make oriented strand board (OSB) paneling for building construction, a cheaper alternative to plywood for paneling. Some automatic mills can process 800 small logs into bark chips, wood chips, sawdust and sorted, stacked, and bound planks, in an hour.

A sawmill or lumber mill is a facility where logs are cut into lumber. Modern sawmills use a motorized saw to cut logs lengthwise to make long pieces, and crosswise to length depending on standard or custom sizes (dimensional lumber). The "portable" sawmill is of simple operation. The log lies flat on a steel bed, and the motorized saw cuts the log horizontally along the length of the bed, by the operator manually pushing the saw. The most basic kind of sawmill consists of a chainsaw and a customized jig ("Alaskan sawmill"), with similar horizontal operation.

Pila (někdy také pilnice) je provozovna, která zpracovává dřevo z polotovaru klád na řezivo (trámy, latě, prkna, fošny apod.) Moderní provozovny často zahrnují i další přidružené činnosti, například zpracování odpadu, a užívá se pro ně název dřevozpracující závod.


Etymology.

The word "Merged" (мэргэд) is a plural form derived from the Mongolian word "mergen" (мэргэн), which means both "wise" and "skillful marksperson", as in adept in the use of bow and arrow. The word is also used in many phrases in which it connotes magic, oracles, divination, augury, or religious power. Mongolian language has no clear morphological or grammatical distinction between nouns and adjectives, so "mergen" may mean "a sage" as much as "wise" or mean "skillful" just as much as "a master." "Merged" becomes plural as in "wise ones" or "skillful markspeople". In the general sense, "mergen" usually denotes someone who is skillful and wise in their affairs.

Three Mergeds.

The Mergeds were a confederation of three tribes, inhabiting the basin of the Selenga and Orkhon Rivers.

Ethnic relations.

The Merkits were related to the Mongols, Naimans, Keraites, and Khitan people.

Conflict with Genghis Khan.

Temüjin's mother Hoelun, originally from the Olkhonud, had been engaged to the Merkit chief Yehe Chiledu by 1153. She was abducted by Temüjin's father Yesugei, while being escorted home by Yehe Chiledu.  In turn, Temüjin's new wife Börte was kidnapped by Merkit raiders from their campsite by the Onon river around 1181 and given to one of their warriors. Temüjin, supported by his brother (not blood-related) Jamukha and his "khan etseg" ('khan father') Tooril Khan of the Keraites, attacked the Merkit and rescued Börte within the year. The Mergids were dispersed after this attack. Shortly thereafter she gave birth to a son named Jochi. Temüjin accepted paternity but the question lingered throughout Jochi's life. These incidents caused a strong animosity between Temüjin's family and the Merkits. Over the next two decades, he attacked them several times.  By the time he had united the other Mongol tribes and received the title Genghis Khan in 1206, the Mergids seem to have disappeared as an ethnic group. Those who survived were likely absorbed by other Mongol tribes (Oirats, Buryats, Khalkhas) and others who fled to the Kipchaks mixed with them. In 1215–1218, Jochi and Subutai crushed the remnants of them under their former leader Toghta Beki's family. The Mongols clashed with the Kankalis or the Kipchakss because they had sheltered the Merged.  Genghis Khan had a Merged khatun (queen) named Khulan. She died while Mongol forces besieged a Kievan Rus' settlement in Ryazan in 1236. In 1236, during the Mongol invasion of Volga Bulgaria, a body of the Merkit was found in the area of land dominated by the Bulgar and Kipchak.

Late Mergeds.

Few Mergeds achieved prominent position among the Mongols, but they were classified as Mongols in Mongolian society. Great Khan Guyuk's beloved khatun Oghul Qaimish, who was a regent from 1248–1251, was a Merged woman. The traditionalist Bayan and his cousin Toghta served as Grand councilors of the Yuan Dynasty in China and Mongolia. After the fall of the Yuan Dynasty, they were a clan of a banner in Northern Yuan dynasty.

The Merkit (, literally ""skillful/wise ones"") was one of the five major tribal confederations ("khanlig") of probably Mongol or Turkic origin later Mongolized in the 12th century Mongolian Plateau.

Merkité () byl mongolský (nebo snad turkický či samodijský) kmen doložený od konce 11. století. Začátkem 13. století byli Merkité násilně začleněni do mongolské říše. Žili v Zabajkalsku, na území současného Burjatska.


Standard-gauge lines.

Three quarters of the Swiss rail network is at standard gauge, comprising, administered mostly by three companies. Important railway stations are the Zürich HB (466,800 passengers per day on a working day), Bern (210,000 ppd), Basel SBB (114,200 ppd), Lausanne (108,900 ppd), Winterthur (108,000 ppd), Luzern (96,200 ppd), Zürich Oerlikon (85,700 ppd), Zürich Stadelhofen (83,300 ppd), Olten (81,300 ppd), and Geneva (73,700 ppd).

Swiss Federal Railways.

Swiss Federal Railways (SBB CFF FFS) is the largest railway company in Switzerland and handles the majority of national and international traffic. It operates the main east–west track in the Swiss Plateau area calling all larger Swiss cities and many smaller ones, and the north–south routes through the Alps via the Gotthard Line (Milano-Chiasso-Lugano-Luzern/Zurich-Basel line) and the Simplon Tunnel (Domodossola to Brig-Lausanne-Geneva line).

BLS.

BLS (Bern-Lötschberg-Simplon) is the other main company, with 10% of the standard-gauge network. It manages the other major Alpine route Bern-Brig via both Lötschberg Tunnels and connection at Brig with SBB's Simplon Tunnel to Italy.

SOB.

The Schweizerische Südostbahn AG (SOB) operates on (of which are their own) between Romanshorn on Lake Constance to St. Gallen. And further via Herisau to the Toggenburg valley in northeast Switzerland. Via Wattwil and Rapperswil SOB travels the track over the Seedamm on Lake Zurich and finally over the high moorland of Rothenthurm down to Arth-Goldau in Central Switzerland.  The named train "Voralpen Express" (VAE, Pre-Alpine Express) is operated by the Südostbahn. It runs every hour between Lucerne and St. Gallen.

Rail links to other countries.

Although both Austria and Germany use the same voltage as Switzerland, dedicated types of locomotives are necessary due to Switzerland using narrower pantographs.  The German national railway company Deutsche Bahn (DB) owns cross-border lines from the German border to Basel Badischer Bahnhof station, which is also operated by DB. It also owns and operates an east–west line across the canton of Schaffhausen that forms a link in the largely German Upper Rhine Railway, and jointly owns Schaffhausen railway station with the Swiss Federal Railways.  The German DB operates longer-distance trains from Germany to Swiss cities, including ICE services to Basel, Zurich, Berne, Chur and Interlaken. On the other hand, Swiss operators run several trains into Germany, e.g. regular EC service to Stuttgart.  The French-Swiss joint-venture TGV Lyria operates high-speed trains between Paris and South-France with services to Geneva, Lausanne, Basel and Zurich.  The Austrian Railjet by ÖBB operates the service between Zurich and several destinations in Austria. The service runs via Buchs SG and calls Innsbruck, Salzburg and Vienna besides others.  SBB and Trenitalia jointly operate EuroCity services between Switzerland and Italy. These services are running between Geneva and Milan or even Venice via the Simplon Tunnel. Between Basel and Milan via Berne and the Lötschberg Base and Simplon Tunnels, and between Zurich and Milan via the Gotthard route.

Narrow-gauge lines.

RhB and MGB.

The Rhätische Bahn (RhB) is the longest metre-gauge railway in Switzerland, linking Arosa, Disentis, Davos, St. Moritz in the high Alps, and Tirano in Italy with Chur, a rail junction with the SBB. It passes through the upper Rhine Valley and several side valleys, as well as the Engadine, the upper valley of the river Inn. The Bernina Pass is the highest point on this line, at 2253 m. Total length: 366 kilometres.  The former Furka Oberalp Bahn (FO) was a metre-gauge railway in the high southern alps. Its name referred to two passes, the Furka Pass and the Oberalp Pass. The Furka Pass lies at the upper end of the Rhône valley. The Oberalp Pass is the highest point on this line at 2033 metres, and lies at the upper end of the Rhine valley. The total length of the railway was 100 kilometres, and the line runs from Disentis to Brig. Brig is a rail junction with the SBB and BLS and sits at the north end of the Simplon tunnel on the Milan to Lausanne CFF line and Milan to Bern BLS line. The former BVZ Zermatt-Bahn (BVZ; BVZ means Brig Visp Zermatt) was a short line between Brig and Zermatt. It passes through the Visp and Matt Valleys, tributaries of the Rhône. Total length: 43 kilometres.  In 2003, the FO and BVZ merged to form the Matterhorn Gotthard Bahn (MGB).  The "Glacier Express" (GEX) runs on the combined three line route St. Moritz/Davos-Filisur-Chur-Disentis-Andermatt-Brig-Visp-Zermatt. A one-day trip in panoramic-view cars takes tourists from St. Moritz/Davos to Zermatt, or vice versa, through some of the most spectacular scenery of the Alps.

Further narrow-gauge lines.

The Appenzeller Bahnen (AB) with its total of 77 km of mainly metre-gauge tracks just recently combined (2006) the earlier separate Trogenerbahn from St. Gallen to Trogen, the standard-gauge railway from Rorschach, Switzerland to Heiden, Switzerland, the short track of the funiculair from Rheineck to Walzenhausen, as well as the previous Appenzeller Bahnen. The AB connects main spots within both Appenzells with St. Gallen and Altstätten in the Alpine Rhine Valley. The Chemin de Fer Montreux Oberland Bernois (MOB) line runs 75 kilometres from Montreux on Lake Geneva to Zweisimmen, with a connecting line to Lenk in the Simmental. The section from Montreux to Zweisimmen, approximately 63 kilometres long, is part of the "Golden Pass Panorama" trip from Montreux to Lucerne, a trip which combines rides on the MOB, the BLS and the Zentralbahn (zb).  From Interlaken, the narrow-gauge Brünigbahn section of the Zentralbahn (zb) runs 74 kilometres further to Lucerne. It skirts Lake Brienz and passes through the range of mountains to the north of the lake via Brünig Pass, and then drops into the Sarner Aa valley to Lucerne. The zb also runs the line between Lucerne and Engelberg.  The Chemins de fer du Jura (CJ), the railways of the Jura canton in northern Switzerland, is an 85-kilometre rail network of which 74 km is metre gauge, the remaining 11 km being standard gauge. It connects La Chaux-de-Fonds to Glovelier and Tramelan, both via Le Noirmont.  The Wynental- und Suhrentalbahn operates in the canton of Aargau in the two mentioned valleys connecting them in Aarau, over a total length of 32.3 km. The Berner Oberland Bahn (BOB) is a 24-kilometre line from Interlaken to Lauterbrunnen and Grindelwald. It begins at Interlaken Ost station and divides at Zweilütschinen, about 10 kilometres south of Interlaken. The western branch leads to Lauterbrunnen, while the eastern branch leads to Grindelwald. It is possible to make a loop by taking the Lauterbrunnen branch and returning via the Grindelwald branch. The two branches are connected by the Wengernalp Bahn.  The Wengernalpbahn (WAB) is a 19-kilometre line from Lauterbrunnen to Grindelwald, leading over the Eiger ridge at the junction station of Kleine Scheidegg. In the winter, this junction is a ski resort served by many lifts and trails, as well as the rail line. Skiers can ride the train from the valleys below to return to the top of the runs.  The Jungfraubahn (JB), which is also rack-and-pinion throughout, starts at Kleine Scheidegg and runs 9 kilometres through tunnels in the Eiger and Mönch, leading to the "Jungfraujoch," a saddle between the Mönch and the Jungfrau summits. At the saddle are a visitor centre and an observatory. The Aletsch Glacier, largest in Europe, runs to the south toward the Rhône valley.  The Bergbahn Lauterbrunnen-Mürren (BLM) is 6 km long, divided into two independent parts, the first part being a cable car (which runs above the old funicular railway, which was replaced in 2006), the second an adhesion railway.  The Chemin de fer Martigny–Châtelard (MC) is 19 km long, with one rack railway section, in the canton of Valais. It connects with the Saint-Gervais–Vallorcine railway in France, the joint services being marketed as "Mont-Blanc Express".  In the canton of Vaud, metre-gauge railways include the Chemin de fer Nyon-St-Cergue-Morez, the Chemin de fer Bière-Apples-Morges, the Chemin de fer Yverdon–Ste-Croix, the Chemin de fer Bex–Villars–Bretaye and the Chemin de fer Lausanne–Echallens–Bercher, as well as part of the longer MOB.  The Ferrovia Lugano–Ponte Tresa (FLP), in canton Ticino, runs 12.3 kilometres from Lugano to Ponte Tresa.  The Gornergrat Bahn climbs for 9 kilometres from an elevation of 1600 metres near the Zermatt station of the Zermatt RR to a 3000-metre high-end station on the shoulder of the Monte Rosa Mountain. The entire route is a rack-and-pinion railway.  At Brienz the Brienz Rothorn Bahn (BRB), a steam-hauled rack railway, ascends to near the summit of the Brienzer Rothorn.

Urban rail.

Trams.

There are trams operating on nine systems in seven Swiss cities. Street-running tramways are nearly all. The Chemin de fer Bex–Villars–Bretaye (BVB) in Bex is more of a mixed interuban light rail line connected to a rack railway but it does have some street running portions, particularly in Bex where the BVB operates along the right of way of a tramway system originally built in the 1890s.

S-Bahn.

In many parts of Switzerland suburban commuter rail service is today known as S-Bahn. Clock-face scheduling in commuter rail has been first put in place on the line Worb Dorf - Worblaufen near Bern in 1964. In 1968 followed the "Golden Coast Express" on the right side of Lake Zurich. 1982 clock-face scheduling was introduced all over Switzerland. The term "S-Bahn" has been used since 1990 for the Zürich S-Bahn, 1995 for Bern S-Bahn and 1997 with the Basel Regional S-Bahn. Other services include "S-Bahn Luzern" and "S-Bahn St. Gallen". But also other terms for commuter rail are in use like "Stadtbahn Zug". Around Fribourg, it is known as Réseau Express Régional (RER), in the region of Geneva the term is Léman Express and in the canton of Ticino Treni Regionali Ticino Lombardia (TILO). The commuter rail networks of Zurich, Basel, Geneva and Ticino provide also cross-border transportation services into Germany, France and Italy.

History.

The construction and operation of Swiss railways during the 19th century was carried out by private railways. The first internal line was a 16 km line opened from Zürich to Baden in 1847. By 1860 railways connected western and northeastern Switzerland. The first Alpine railway to be opened under the Gotthard Pass in 1882. A second alpine line was opened under the Simplon Pass in 1906.  In 1901 the major railways were nationalised to form Swiss Federal Railways. During the first half of the twentieth century they were electrified and slowly upgraded. After the Second World War rail rapidly lost its share of the rail market to road transport as car ownership rose and more roads were built. From 1970 the Federal Government has become more involved in upgrading the railways, especially in urban areas and on trunk routes under the Rail 2000 project. In addition, two major trans-alpine routes—the Gotthard Railway and the Lötschberg approach to the Simplon Tunnel—are being rebuilt under the NRLA project.

Integration of services.

Between rail services.

Services on the Swiss railway are integrated with each other and with other forms of public transport. Unlike its European neighbours, Switzerland has not developed a comprehensive high-speed rail network, with the running speed on its one stretch, called the Rothrist-Mattstetten line, of relatively high-speed line being 200 km/h. Instead the priority is not so much the speeding up of trains between cities, but the reduction of connection times through the nodal system. Journey times on main lines between hubs are multiples of 15 minutes so that on the hour or half-hour all trains stand in the main stations at the same time, thus minimising connection times. Indeed, the above-mentioned Rothrist-Mattstetten line reduces journey times from Bern to Zurich from 72 minutes to 57 minutes, in keeping with the clock face scheduling.

Between modes of transport.

Rail timetables are integrated with the extensive network of postal buses (branded as "PostBus",,, ) which serve both plain and high mountain villages. For example, on postal bus line 12.381 the 10:35 from the mountain village of Les Haudères is planned to arrive in the regional city of Sion at 11:20 where a train departs the station (located next to the bus station) at 11:24 for Visp. Indeed, it is a familiar sight to for the postal cars to be already lined up outside the station for the arriving train. From this perspective, the Swiss rail network functions as the core of a wider public transport network.

Costs and subsidies.

Although public investment is positively correlated with a given railway system's performance, the European Railway Performance Index finds differences in the value that countries receive in return for their public cost. The 2017 Index found Switzerland captures high value for money relative to the average ratio of performance to cost among European countries.

Passenger transport.

In 2012, the total costs for passenger transport on Swiss railway network was CHF 8.88 billion, of which CHF 4.46 billion (50%) were due to infrastructure costs, CHF 3.98 billion (45%) were costs of transportation means, CHF 427 million due to environmental and health costs, and CHF 25 million due to accidents.  CHF 4.28 billion, or 48.2%, were paid by passengers, and CHF 4.15 billion (or 47%) came from rail subsidies provided by federal, cantonal, and municipal contributions. CHF 426 million (or 4.8%) were contributed by the common weal (accident and health insurances, environmental funds etc.).

Freight transport.

In 2012, the total costs for freight transport on Swiss railway network was CHF 2.063 billion, of which CHF 779 million (37.8%) were due to infrastructure costs, CHF 900 million (43.6%) were costs of transportation means, CHF 59 million due to environmental and health costs, and CHF 325 million (15.8%) due to accidents.  CHF 1.058 billion, or 51.3%, were paid by customers, and CHF 122 million (5.9%) by transporting companies, while CHF 555 million (26.9%) were subsidised by federal, cantonal, and municipal contributions. CHF 328 millions (15.9%) were contributed by the common weal (accident and health insurances, environmental funds etc.).

The Swiss rail network is noteworthy for its density, its coordination between services, its integration with other modes of transport, timeliness and a thriving domestic and trans-alp freight system. This is made necessary by strong regulations on truck transport, and is enabled by properly coordinated intermodal logistics. In 2015, with network length, Switzerland has not only the world's most dense railway network ( km/10km, except for very small countries and city-states) despite the Alps covering about 60% of its surface, but it is also a world leader in kilometres traveled: per inhabitant and year (2015). Virtually 100% of its network is electrified, except for the few tracks on which steam locomotives operate for tourism purposes only. There are 74 railway companies in Switzerland. The share of commuters who travel to work using public transport (as main mode of transport) is 30%. The share of rail in goods transport performance by road and rail (modal split) is 39%.

Kolejová doprava tvoří ve Švýcarsku páteř veřejné dopravy. Švýcarsko má hustou železniční síť s dobrou nabídkou služeb. Klasická železniční doprava spolu se zajímavými horskými a úzkorozchodnými drahami v Alpách je jedním ze znaků Švýcarska.


Early life.

Mase was born Mason Durell Betha in Jacksonville, Florida, on August 27, 1975, as a fraternal twin born almost two months premature, to P. K. Betha and Mason Betha. He grew up with two brothers and three sisters, including his twin sister, Stason, born a few minutes after him. The father left the family when Mase was just three years old. In 1982 his mother moved herself and her children to Harlem, New York, where Mase spent the majority of his childhood. During his early teenage years, Betha began getting into trouble on the streets of Harlem, and when he was 13 his mother sent him back to Jacksonville to live with relatives. While living in Jacksonville, Betha first began attending church. After returning to live in Harlem at age 15, Betha began showing promise as a basketball player, becoming the leading point guard for his team at Manhattan Center high school during the 1993 season, where he played alongside Cameron Giles, who went on to be the rapper known as Cam'ron. He had hopes of joining the National Basketball Association (NBA), but was unable to make it into a Division I College due to his poor academic scores. He attended State University of New York at Purchase, where he grew to realize he was unlikely to make the NBA and instead began focusing more on writing music, producing demo tapes and regularly performing at local nightclubs. Betha eventually dropped out of college and focused on his music career full time.

Career.

1993-97: Children of the Corn and Bad Boy record deal.

After Betha returned to Harlem, he and his childhood friend Cam'ron began rapping as a hobby under the names Murda Mase and Killa Cam, briefly forming a group known as the Children of the Corn ("corn" short for "corner") with fellow Harlem rappers Big L, Herb McGruff and Bloodshed. Damon Dash, a fellow Manhattan Center student, was the group's manager for a while. In 1996, Mase's sister Stason introduced him to Cudda Love, a road manager for The Notorious B.I.G. Cudda took the 20-year-old Mase to Atlanta, Georgia, where Jermaine Dupri and Sean "Puff Daddy" Combs were attending a rap convention. Shortly after meeting and rapping for Puff Daddy at the Hard Rock Café, Mase signed a $250,000 deal with Bad Boy Records. Within a week of signing to the label, Betha had his stage name shortened from Murda Mase to simply Mase to make him more marketable, and was featured on and in the video for 112's "Only You" with the Notorious B.I.G. He also appeared on many hit songs with other Bad Boy artists, including Puff Daddy's “Can't Nobody Hold Me Down” and “Been Around the World” and the Notorious B.I.G.'s “Mo' Money, Mo' Problems”, which reached number 1 on the Billboard Hot 100.

1997-98: "Harlem World".

Mase's first studio album, "Harlem World", debuted at #1 on the "Billboard" Pop and R&B LP charts, selling over 270,000 copies in the U.S. during its first week of release. It has since achieved 4x Platinum status in the United States. The album spawned hit singles such as "Feel So Good" and "Lookin' at Me", which both reached #1 on the Rap Billboard charts, as well as "What You Want", which peaked at #3 on both the Rap and R&B Billboard charts. During 1997, Mase also appeared on more songs with Puff Daddy, Mariah Carey's "Honey", Brian McKnight's "You Should Be Mine (Don't Waste Your Time)", and Brandy's "Top of the World".  In 1998, Mase formed his own record label, All Out Records. He signed his group Harlem World, which included his twin sister, Stason, to the label while they were also under So So Def Recordings. He and Harlem World member Blinky Blink were featured on Blackstreet & Mýa's song "Take Me There", which appeared on the soundtrack of "The Rugrats Movie".

1999: "Double Up" and retirement.

Mase's second album, "Double Up", was released in 1999 on Bad Boy and sold 107,000 copies in its first week, debuting at #11 on the US Top 200 chart. In "Double Up" Mase's lyrics became more aggressive.  On April 20, 1999, during an interview with Funkmaster Flex on New York radio station Hot 97, Mase announced his retirement from music to pursue a "calling from God". He claimed he was "leading people, friends, kids and others down a path to hell", stating that he left to find God in his heart and follow him. He said it was time for him to serve God in "his" way, saying rap was not real, and that he wanted to deal with reality and had become unhappy with what he did, no matter how much money it had made him. The same year, Mase enrolled as a freshman at Clark Atlanta University, a historically black college, and began taking classes on August 19. Unlike other freshmen, Mase was permitted to live off campus and commute, but he is said to have downplayed his past as a rapper and stayed fairly low-key while on campus.

2004: Return to music.

After a five-year hiatus from music, during which he became an ordained minister, Mase made his return to music with "Welcome Back" in summer 2004. Before the album's release, Mase was featured on Nelly's "In My Life" as well as the remix to Fat Joe's "Lean Back".  "Welcome Back" was accompanied by a single of the same name and was released on August 24, 2004, through Bad Boy Records and distributed by Universal Music Group. It debuted at #4 in the US, selling 188,000 copies in its first week of release, and eventually went gold, selling 559,000 copies in the United States. The album portrayed Mase's new Christian lifestyle and "cleaner" image. Mase dubbed himself "a Bad Boy gone clean" on the lead single, also titled "Welcome Back". This new approach had a mixed reception. Although the album was not as big a commercial success as "Harlem World", the singles "Welcome Back" and "Breathe, Stretch, Shake" received moderate radio airplay and video play on BET and MTV, with the latter single reaching #28 on the US "Billboard" Hot 100. Both singles were also certified gold by the RIAA.  In the mid-2000s, Mase spent time touring and recording with New York hip-hop group G-Unit, and became a mainstay of 50 Cent's public image during that time, appearing with him on magazine covers, on stage, and in music videos. He has since said that working with the group was not something he regrets, but that the message he was sending was a mistake. He joined G-Unit to appeal to a different audience so they could see that they could change just as he did, thinking that "in order to get people where I'm at, I have to go back to where I once was". Under G-Unit, he released "Crucified 4 The Hood: 10 Years of Hate", a mixtape from the DJ Whoo Kid series, but an official album was never released.

2009: Second comeback.

Following the formula that worked for him years earlier, Mase has begun to appear on R&B artists' remixes. In early June 2009, he was featured on the last verse of "Uptown Boy" by Harry O, signed to The Inc. Records, which also features Ron Browz. Weeks later, Mase appeared on a street remix for Drake's "Best I Ever Had". Mase stated that Michael Jackson's death influenced him to make a comeback. He appeared on Power 105.1 to discuss his comeback with "The Prince of New York" DJ Self. Mase used that radio show as his outlet to release new music throughout the rest of the summer, with a new song or feature premiere every Friday on DJ Self's show.  The first new track featuring Mase was released on July 10, featuring the first verse on "Get It," which was produced by Big Ran and also featured Cam'ron. Mase released the Ron Browz produced "Thinkin' 'Bout You" on July 17, then followed that up by adding a verse to the street remix of Teairra Marí and Kanye West's "Diamonds", on July 24. Mase used the last Friday in July to "Shut the City Down," which was the title of his second solo release since his comeback began. The song primarily discusses the rapper's legacy and makes reference to the ways in which rap, as a business, has changed since his heyday. He also makes reference to his new Batman-esque logo, and hints at himself as hip-hop's superhero. Mase released the song "Radio" on August 21 as a prelude to his upcoming mixtape "I Bleed Money." On September 11, Mase was one of the featured artists who appeared on the remix to Ron Browz's "Gimme 20 Dollars." This was the third time since his comeback that he worked with Browz and his first collaboration with Jim Jones since their falling out years before.  In October 2009, Mase made an impromptu appearance on a live radio interview with Diddy-Dirty Money on V-103. He told the studio staff he brought documentation that would release him from the Bad Boy label and gave the forms to Diddy during the interview. Diddy signed the forms and announced "[Mase] has the freedom to go do whatever he wants to do." It was later revealed the forms did not end Mase's contractual obligations to the record label, but rather allowed him to appear on songs with artists from different labels.

2010–present: "Now We Even".

In 2010, Diddy offered Mase a one-year release from Bad Boy Records to settle all their differences, with which Mase decided to retire from rap for good although he was to be re-signed to Bad Boy after the year was up. On April 17, 2012, Spiff TV Films – a production company best known for videos made for Rick Ross's Maybach Music Group releases – tweeted a photo of Mase, Ross and French Montana, as well as singer Omarion and producer Rico Love, together in the studio. The picture sparked speculation that Mase would be making his third return to music since his announced retirement to become a pastor in April 1999 and leaving again in 2007. A week after the photo appeared, DJ Funkmaster Flex debuted a remix of Wale's "Slight Work" on radio show.  Speaking during an on-air call following the remix's debut, Mase didn't address rumors about him possibly signing with Warner Brothers imprint Maybach Music Group, rather revealing that Bad Boy artist French Montana was the reason Mase was making his third comeback. Mase is served as an A&R representative on Montana's forthcoming Bad Boy debut, "Excuse My French", as well as appearing on the remix of Montana's "Everything's a Go". "I'm not sure what kind of decisions he's going to make," Montana says, "[but] I would love to see him in my camp." In September 2012, Mase appeared on Kanye West's album "Cruel Summer", on the track "Higher" with The-Dream, Pusha T, and Cocaine 80s.  In December 2012, Mase announced that he was no longer signed to Bad Boy Records, saying he would not likely sign with a major label anytime soon. He told MTV the only two labels he would consider signing with were Kanye West's GOOD Music or Drake's OVO Sound. On October 18, 2013, Mase announced his next album would be titled "Now We Even". He also said his wish list for guest appearances would include Jay-Z, Diddy, Beyoncé, Drake, 2 Chainz, Lauryn Hill, Meek Mill, Fabolous, Ariana Grande, Dipset, Eric Bellinger, Seal and CeeLo Green.  On November 24, 2017, Mase released "The Oracle", a diss track at friend-turned-rival Cam'ron in response to the lyrical jabs Cam'ron aimed at him on his mixtape "The Program".

Legacy and influence.

Mase's melodic rap style has had an enduring influence on hip hop. Many rappers, such as Pusha T, Fabolous and Kanye West, have adopted Mase's lazy, yet melodic flow on several occasions. Jay Z and Drake among other rappers have borrowed Mase lines in their songs. Kanye West has described Mase as his favorite rapper ever.

Mason Durell Betha (born August 27, 1975), better known by his mononym Mase (formerly Murda Mase and stylized as Ma$e), is an American rapper, songwriter and minister. In the late 1990s he recorded at Bad Boy Records alongside Sean "Diddy" Combs. From 1996 to 1999, as a lead or featured artist, Mase had six Billboard Hot 100 Top 10 singles and five US Rap No. 1 singles. His 1997 album "Harlem World" was Grammy nominated and certified quadruple Platinum by RIAA. His two other albums, "Double Up" and "Welcome Back", are both certified Double platinum and Gold by RIAA.

Mason Durell Betha (* 27. srpna 1977, Jacksonville, Florida) spíše známý jako Mase je americký rapper. Nejvíce známý pro své debutové album "Harlem World" (1997).


History.

Origins and early lineups.

Canned Heat was started within the community of blues collectors. Bob Hite had been trading blues records since his early teens and his house in Topanga Canyon was a meeting place for people interested in music. In 1965 some blues devotees there decided to form a jug band and started rehearsals. The initial configuration comprised Hite as vocalist, Alan Wilson on bottleneck guitar, Mike Perlowin on lead guitar, Stu Brotman on bass and Keith Sawyer on drums. Perlowin and Sawyer dropped out within a few days, so guitarist Kenny Edwards (a friend of Wilson's)

Rise to fame and formation of the classic lineup.

The first big live appearance of Canned Heat was at the Monterey Pop Festival on June 17, 1967. A picture of the band taken at the performance was featured on the cover of "Down Beat" where an article complimented their playing: "Technically, Vestine and Wilson are quite possibly the best two-guitar team in the world and Wilson has certainly become our finest white blues harmonica man. Together with powerhouse vocalist Bob Hite, they performed the country and Chicago blues idiom of the 1950s so skillfully and naturally that the question of which race the music belongs to

"Going Up the Country" and Woodstock.

In October the band released their third album, "Living the Blues", which included "Going Up the Country", their best-known song. Wilson's incarnation of Henry Thomas' "Bull-Doze Blues" was almost a note-for-note copy of the original, including Thomas' instrumental break on the "quills" (pan-pipes) which Jim Horn duplicated on flute. Wilson rewrote the lyrics with a simple message that caught the "back-to-nature" attitude of the late 1960s. The song went to #1 in 25 countries around the world (#11 on the U.S. national chart) and would go on to become the unofficial theme song of the Woodstock Festival as captured in Michael Wadleigh's 1970 documentary. The album also included a 19-minute experimental track "Parthenogenesis", which was a nine-part sound collage of blues, ragas,

"Hooker 'n Heat" and the death of Wilson.

With Taylor and Mandel gone, Vestine returned on guitar, accompanied by bassist Antonio de la Barreda who had played with de la Parra for five years in Mexico City and was previously a member of the groups Jerome and Sam & the Goodtimers.  This lineup went into the studio to record with John Lee Hooker the tracks that would yield the double album, "Hooker 'n Heat". The band had originally met Hooker at the airport in Portland, Oregon, and discovered they were fans of each other's work. Hooker and Canned Heat became good friends and Hooker had stated that Wilson was "the greatest harmonica player ever". The planned format for the sessions called for Hooker to perform a few songs by himself, followed by some duets with Wilson playing piano or guitar. The rest of the album featured Hooker with some backing by the group (sans Bob

"Historical Figures", "New Age" and "Human Condition" line-ups.

Joel Scott Hill, who had played with the Strangers and the Joel Scott Hill Trio, was recruited to fill the void left by Wilson's death. The band still had a touring contract for September, as well as upcoming studio dates. That fall they toured Australia and Europe; including a show played in Baarn, Netherlands, for the VPRO television program "Piknik" and the following summer they appeared at the Turku Festival in Finland. These performances were recorded, but the recordings were not released until much later, with the albums "Live at Turku Rock Festival" in 1995 and "Under the Dutch Skies 1970–74" in 2007 (which encompassed three separate tours). At the end of 1971 a new studio album, "Historical Figures and Ancient Heads", was released. The album included Hite's vocal duet with Little Richard on "Rockin' with the King", written by Skip Taylor and featuring the guitar playing of

Burger Brothers revival and the death of Bob Hite.

The popularity of the blues genre rose in the late 1970s and early 1980s with the release of the musical-comedy film "The Blues Brothers" (1980), starring Dan Aykroyd and John Belushi. During this time, de la Parra had bought into the partnership of an East Hollywood recording studio at which he was again working with former bandmate Larry "The Mole" Taylor. Taylor had been associating with virtuoso guitar player Mike "Hollywood Fats" Mann and virtuoso piano player Ronnie Barron and before

Later history and the death of Vestine.

The death of frontman Bob "The Bear" Hite was a devastating blow that most thought would end the career of Canned Heat; however de la Parra kept the band alive and would lead it back into prosperity over the next few decades. An Australian tour had been set up before The Bear's death and harmonica player Rick Kellogg had joined to finish off the "Kings of the Boogie" album. This incarnation of Canned Heat without Bob Hite was nicknamed the "Mouth Band" by Vestine and was a huge hit in Australia, especially with the biker crowd. Under the management of "The Push", the band toured the States playing biker bars and began work on a video known as ""The Boogie Assault"", starring Canned Heat and

Canned Heat in the 2000s and 2010s.

Canned Heat's popularity has endured in some European countries and Australia. In Belgium they have a particularly devoted following thanks in great part to Walter de Paduwa, a.k.a. Dr. Boogie, considered by the band as their "official historian". He has assisted de la Parra in compiling and producing, "The Boogie House Tapes Vol. 1" in 2000, "The Boogie House Tapes Vol. 2" in 2004, and "Dr. Boogie Presents Rarities from the Bob Hite Vaults" in 2008; all collected from unreleased and rare Canned

Collaborations.

Canned Heat have collaborated with many blues artists, recording and helping them to regain some notoriety. Notable names include:

Canned Heat is an American rock band that was formed in Los Angeles in 1965. The group has been noted for its interpretations of blues material and for its efforts to promote interest in this type of music and its original artists. It was launched by two blues enthusiasts Alan Wilson and Bob Hite, who took the name from Tommy Johnson's 1928 "Canned Heat Blues", a song about an alcoholic who had desperately turned to drinking Sterno, generically called "canned heat", from the original 1914 product name Sterno Canned Heat, After appearances at the Monterey and Woodstock festivals at the end of the 1960s, the band acquired worldwide fame with a lineup consisting of Hite (vocals), Wilson (guitar, harmonica and vocals), Henry Vestine and later Harvey Mandel (lead guitar), Larry Taylor (bass), and Adolfo de la Parra (drums).

Canned Heat je bluesrocková skupina, která vznikla v Los Angeles v Kalifornii v roce 1965. Skupina původně hrála klasické bluesové skladby. Založili ji Alan Wilson a Bob Hite. Název vznikl z písně „Canned Heat Blues“ od Tommyho Johnsona z roku 1928. Po vystoupení na festivalech v Monterey nebo na Woodstocku na konci šedesátých let se skupina proslavila téměř po celém světě. Nejklasičtější sestava skupiny byla: Bob Hite, přezdívaný „The Bear“ (zpěv), Alan Wilson, přezdívaný „Blind Owl“ (kytara, foukací harmonika, zpěv), Henry Vestine („Sunflower“) nebo Harvey Mandel („The Snake“) na sólové kytaře, Larry Taylor, přezdívaný „The Mole“ (baskytara) a Adolfo de la Parra, přezdívaný „Fito“ (bicí).


Operation.

Most antivirus programs that utilize heuristic analysis perform this function by executing the programming commands of a questionable program or script within a specialized virtual machine, thereby allowing the anti-virus program to internally simulate what would happen if the suspicious file were to be executed while keeping the suspicious code isolated from the real-world machine. It then analyzes the commands as they are performed, monitoring for common viral activities such as replication, file overwrites, and attempts to hide the existence of the suspicious file. If one or more virus-like actions are detected, the suspicious file is flagged as a potential virus, and the user alerted.  Another common method of heuristic analysis is for the anti-virus program to decompile the suspicious program, then analyze the machine code contained within. The source code of the suspicious file is compared to the source code of known viruses and virus-like activities. If a certain percentage of the source code matches with the code of known viruses or virus-like activities, the file is flagged, and the user alerted.

Effectiveness.

Heuristic analysis is capable of detecting many previously unknown viruses and new variants of current viruses. However, heuristic analysis operates on the basis of experience (by comparing the suspicious file to the code and functions of known viruses). This means it is likely to miss new viruses that contain previously unknown methods of operation not found in any known viruses. Hence, the effectiveness is fairly low regarding accuracy and the number of false positives.  As new viruses are discovered by human researchers, information about them is added to the heuristic analysis engine, thereby providing the engine the means to detect new viruses.

What is Heuristic Analysis?

Heuristic analysis is a method of detecting viruses by examining code for suspicious properties.  Traditional methods of virus detection involve identifying malware by comparing code in a program to the code of known virus types that have already been encountered, analyzed and recorded in a database – known as signature detection.  While useful and still in use, signature detection method has also become more limited, due to the development of new threats which exploded around the turn of the century and are continuing to emerge all the time.  To counter this problem, the heuristic model was specifically designed to spot suspicious characteristics that can be found in unknown, new viruses and modified versions of existing threats as well as known malware samples.  Cybercriminals are constantly developing new threats, and heuristic analysis is one of the only methods used to deal with the huge volume of these new threats seen daily.  Heuristic analysis is also one of the few methods capable of combating polymorphic viruses — the term for malicious code that constantly changes and adapts. Heuristic analysis is incorporated into advanced security solutions offered by companies like Kaspersky Labs to detect new threats before they cause harm, without the need for a specific signature.

How Does Heuristic Analysis Work?

Heuristic analysis can employ a number of different techniques. One heuristic method, known as static heuristic analysis, involves de-compiling a suspect program and examining its source code. This code is then compared to viruses that are already known and are in the heuristic database. If a particular percentage of the source code matches anything in the heuristic database, the code is flagged as a possible threat.  Another method is known as dynamic heuristics. When scientists want to analyze something suspicious without endangering people, they contain the substance in a controlled environment like a secure lab and conduct tests. The process is similar for heuristic analysis — but in a virtual world.  It isolates the suspicious program or piece of code inside a specialized virtual machine — or sandbox — and gives the antivirus program a chance to test the code and simulate what would happen if the suspicious file was allowed to run. It examines each command as it's activated and looks for any suspicious behaviors, such as self-replication, overwriting files, and other actions that are common to viruses. Potential Issues are reported to the user.  Heuristic analysis is ideal for identifying new threats, but to be effective heuristics must be carefully tuned to provide the best possible detection of new threats but without generating false positives on perfectly innocent code.  For this reason, heuristic tools are often typically just one weapon in a sophisticated antivirus arsenal. They are typically deployed along with other methods of virus detection, such as signature analysis and other proactive technologies.

Heuristic analysis is a method employed by many computer antivirus programs designed to detect previously unknown computer viruses, as well as new variants of viruses already in the "wild".

Heuristická analýza (řecky heuriskó) je v informatice metoda využívající zkusmé řešení problému, protože přesnější metoda či algoritmus není k dispozici, využívá přitom intuici, zkušenosti. Existují různé heuristické postupy. Heuristika je často využívána antivirovými programy, kde slouží k detekci dosud neznámých počítačových virů.


Geology and mineralogy.

The lava historically erupted from Izalco consists of vesicular vitrophyric olivine basalts. Izalco's formation was preceded by fumorolic activity in 1658, before Izalco was born in 1770. Today, Izalco experiences only fumarolic activity in the form of rainwater seeping into the volcano and contacting hot rocks, rather than steam emissions from underground gases. The fumarole deposits of the volcano are noted as sources for several rare minerals. It is the type locality for the copper vanadium minerals: bannermanite, blossite, fingerite, howardevansite, lyonsite, mcbirneyite, stoiberite and ziesite.

Tourism.

The volcano is visited and climbed regularly by tourists to El Salvador via the Cerro Verde National Park and is a national icon of the country, even featured on the 10 colón bank note (US dollars replaced the colon in 2001, so the bank note is no longer in circulation). The volcano is currently quiescent but may erupt again.  A hotel was built on the nearby Cerro Verde to provide accommodation with a view of the erupting volcano, but the volcano ceased to erupt shortly before the hotel was completed.

Izalco Volcano National Symbolism.

The volcano on the stamps' central oval design is an allegorical representation of the coat of arms existing at the time; the stamps depict the Izalco volcano, popularly known as "El Faro del Pacífico" - "The Lighthouse of the Pacific". This argument is based on the fact that the decree signed by Francisco Duenas, creating the coat of arms, specifically mentions the Izalco volcano as the inspiration for its design, and also on the idea that the Izalco volcano was (and still is) one of the symbols of the country. Covers genuinely used with these stamps are rare. So far, only 37 have been recorded.

Izalco is an active stratovolcano on the side of the Santa Ana Volcano, which is located in western El Salvador. It is situated on the southern flank of the Santa Ana volcano. Izalco erupted almost continuously from 1770 (when it formed) to 1958 earning it the nickname of "Lighthouse of the Pacific", and experienced a flank eruption in 1966. During an eruption in 1926, the village of Matazano was buried and 56 people were killed. The formation of the volcano actually occupied highly arable land on the southern slope of the Santa Ana volcano which was used for the production of coffee, cacao and sugar cane.

Izalco je v současnosti již neaktivní stratovulkán nacházející se v Salvadoru v blízkosti stejnojmenného města Izalco v departementu Sonsanate. Sopka se vyvinula jako parazitický kužel nedalekého stratovulkánu Santa Ana. Svoji činnost započala v roce 1770, poslední erupce se odehrála v říjnu 1996. Během doby své aktivity patřila k nejaktivnějším sopkám v Salvadoru, známá též jako "El Faro del Pacífico" (česky Pacifický maják) díky pravidelné téměř neustálé činnosti, lávové proudy bylo možno vidět až od pacifického pobřeží. Postupem času Izalco převýšilo okolní terén o 600 metrů, nadmořská výška vrcholu je 1950 m n. m.


Geography.

Tulle is the third largest town in Limousin, behind Limoges and Brive-la-Gaillarde. It is situated in a very deep part of the river Corrèze valley, at its confluence with several of its tributaries, the Solane and the Céronne on the right bank, and the Saint-Bonnette and the Montane on the left bank. It stretches along a very narrow strip several kilometres long from the north-east to the south-west.  Tulle is located at the crossroads of several communication routes:  Tulle is the meeting point between the South-West of France and the Massif Central. It is the former capital of Bas-Limousin, whose boundaries correspond approximately to the current department of Corrèze.

History.

Antiquity.

The origins of the town are still subject to debate today but it would seem that the present puy Saint-Clair, a rocky spur with steep slopes separating the Corrèze valley from that of the Solane, was an ideal location for the establishment of a Gallic oppidum. For a long time, it seems that the town has been an important crossroads on the road between Armorique and the Mediterranean Sea and on the road between Aquitaine and the Rhone Valley. Both of which crossed the Corrèze at this point by a ford.  With the Roman occupation, the place would have been converted into a necropolis and a temple in honour of Tutela, a Roman divine power to whom the protection of people, things and especially places was entrusted, would have been built. It is from this Roman goddess, protector of the travellers who used to use the ford, that the name of the city would come from. The temple of Tutela must have been located in the Trech district, whose name refers to the crossing of a river. The real urban centre of the region moved a few kilometres north, to the commune of Naves and the site of Tintignac, which became a crossroads between the Roman roads that followed the ancient routes of the Celtic period.

Middle Ages.

The Merovingian period would have seen the Christianization of the city and the establishment of three places of worship dedicated to St. Martin, St. Peter and St. Julian. The city officially entered history only with the transformation in the 7th century of the church dedicated to Saint Martin into a monastery under the impetus of Calmine, already founder of the monastery of Mozat in Auvergne. Around the places of worship began to gather the inhabitants of the country and Tulle became once again an urban centre, a status lost since the Roman conquest.  The town was plundered several times by the Vikings, despite being several hundred kilometres from the sea, and it was during one of these sackings, in 846, that the first monastery was destroyed. To warn the inhabitants of the town of the arrival of the Vikings, a watchtower was built on a rocky promontory at Cornil, a few kilometres downstream from the Corrèze. The place was nevertheless considered safe by many churches on the Atlantic coast who had sent their relics there to preserve them from looting, notably those of Saint Clair, Saint Lô and Saint Baumard. The monastery was later rebuilt but disappeared in the 11th century. In 1989, excavations under the nave of the present cathedral uncovered the remains of an absidiole dating from the Carolingian period as well as a poly-lobed portal of Mozarabic influence.  New constructions are undertaken for the abbey, now dedicated to Saint Martin and converted to Benedictine rule in the 11th century. On a visit to Tulle in 1095, Pope Urban II granted it his protection. The first stone of the new abbey church was laid in 1130 but the building was not completed until two centuries later. The spire of the 12th century culminates at a height of 75 meters, making it the highest in Limousin. In 2005, during construction in the vicinity of the cathedral, excavations uncovered the north wall of the medieval church of Saint-Julien, the discovery of a cemetery and three granite sarcophagi dating from the High Middle Ages. In addition, the Gothic cloister is the last one preserved in Limousin.  In 1317, Pope John XXII created the diocese of Tulle by detaching fifty-two parishes from the diocese of Limoges and the abbey-church became a cathedral. During the Hundred Years' War, the English took the city in 1346 before being driven out of it a month later by the Count of Armagnac, suffering in quick succession two trying sieges during which the inhabitants were reduced to famine. In 1370, the city sided with the King of France, Charles V, which earned it tax exemption and the ennoblement of several bourgeois families. But in 1373, the Duke of Lancastre appeared before the city and demanded that the gates be opened to him, and, in the absence of any command, a representative assembly of the population was convened and decided to carry out a new sacking. The pardon of the King of France for this betrayal took place in 1375.  The black plague hit the city in 1348 and, on the evening of June 23rd, in despair, the city authorities decided to march behind a statue of Saint John to stop what was considered a divine scourge. The plague ceased shortly afterwards, and the Tullists promised to renew this procession every year. It is still perpetuated today and is called the "Procession of the Lunade".  At the beginning of the 15th century, the town fell victim to the so-called "roadmen", brigands such as Jean de La Roche who set fire to the town in 1426 or Rodrigue de Villandrando to whom the town had to pay a large ransom in order to be spared in 1436. In 1430, the bishop recognised the power of thirty-four prud'hommes, also called "boniviri", who had military and financial powers but who had in fact been dealing with the affairs of the community unofficially since the 13th century. In 1443, Charles VII convened the Estates General of Bas-Limousin in Tulle.  The town was then divided between l'Enclos, the district around the abbey-church where the nobles, bourgeois and clerics lived, and the upper town, where most of the population lived, around the castle, located on the puy Saint-Clair and which is still characterized today by its narrow, steep streets, sometimes with stairs. In the 14th century, several noble families (Saint-Martial de Puy-de-Val, Rodarel de Seilliac,...) began to extend the town on the left bank of the Corrèze, opposite the Cathedral, in the Alverge district, on the road towards Auvergne. In the 15th century, the city expanded outside its ramparts, in suburbs along the roads towards Aquitaine and the South (la Barrière and le Pilou), to Limoges and Paris (la Barussie, le Trech, le Fouret, la Rivière) and towards Auvergne (l'Alverge and le Canton).

Modern period.

The abbey is practically disused with the secularization of 1514. The bishop had a castle built and the refectory became the seat of the court. In 1566, King Charles IX endows the town with a town hall and a consulate which definitively reduces the power of the bishop.  During the Wars of Religion, Tulle held out for the Catholics; the town first resisted the Huguenots in 1577, but the troops of the Viscount of Turenne took bloody revenge in 1585. They ransacked and devastated the town after an assault that the Protestant poet Agrippa d'Aubigné recounted.  In the 16th century, the nobles and bourgeois of Tulle engaged in a veritable architectural competition, of which buildings with finely crafted facades in Renaissance style such as the Hôtel de Lauthonye (1551), the Hôtel de Ventadour or the Loyac house described by Prosper Mérimée in 1838, still stand today. In the 16th century, a college was created and in 1620, teaching was entrusted to the Jesuits. In 1670, the town was equipped with a general hospital.  Numerous religious congregations settled in the town, the Recollects (1601), the Poor Clares (1605), the Feuillants (1615), the Ursulines (1618), the Bernardines (1622), the Visitandines and the Carmelites (1644) as well as the Benedictines in 1650. In 1705, Sister Marcelline Pauper founded a house in Tulle for the congregation of the Sisters of Charity of Nevers, to relieve the misery of the people and to teach children to read.  From the 17th century onwards, new economic activities appeared, the mills on the Corrèze and Solane rivers being used to produce paper for example. The lace craft develops and the "poinct de Tulle" develops until its fame becomes worldwide, tulle being frequently used for wedding dresses in particular. It was also the beginning of the arms industry in Tulle with the establishment of a factory in 1691 resulting from the collaboration between the master harquebusier Pauphile and the financier Fénis de Lacombe. The firearms factory will become a royal factory in 1777.  The mutilations of the cathedral and the abbey buildings were very significant during the French Revolution because, converted into a weapons factory, all the fittings, including the irons supporting the dome, were torn off for recovery, causing the collapse of the dome, the chevet, the transept and the north gallery of the cloister in 1796. The Episcopal Palace, two parish churches and several chapels in the suburbs were destroyed during the Revolution. The church was reopened for worship in 1803 but did not regain its title of cathedral until 1823, while the dome was never rebuilt, the nave being simply closed and the open space used for a promenade along the Corrèze on the current Quai Edmond-Perrier.

Contemporary era.

From the 19th to World War II.

During the 19th century, the physiognomy of Tulle changed a lot. A railway station opened in Souilhac district in 1871 and the town was then connected to the national railway network via Brive-la-Gaillarde. At the same time, new industries were created, notably the firearms factory. In 1886, the latter was nationalized and settled in the new district of Souilhac, along the Céronne, a river that would provide it with electricity with the construction of a hydroelectric power station in 1888. From 1917 onwards, trains passing on the nearby tracks would supply the thermal power station with coal at the level of the present Socio-Cultural Centre. Up to 5,000 employees worked at the "Manu'" as it was then known. The Manu' was the economic lung of the city and influenced the social composition of the Tullist population, which was strongly coloured by the workers.  The urban junction between the working-class district of Souilhac and the historic district of the Cathedral is made by the urbanization of the current avenue Victor-Hugo. As in many other French cities inspired by the renovations of Baron Haussmann in Paris, the end of the 19th century saw the city open up, notably with the construction of the current Avenue du Général-de-Gaulle in the Trech district and the enlargement of the Place de la Cathédrale. At the same time, work was undertaken to limit the frequent floods and to clean up the city by burying the Solane river, which until then had flowed at the foot of the buildings. The city also acquired new public buildings in its role as the prefecture and main city of the department, such as the construction of the Town Hall (former bishopric), the Prefecture, the Hôtel Marbot (former Grand Séminaire), the Law Courts, the Post Office, the Halle-Gymnase (now the Latreille Hall) and the Lycée Edmond-Perrier, many of which were built in an Art Nouveau style. Completed in 1899, the Theatre is a monument of Anatole de Baudot, the first building of its kind in the world in reinforced cement. From the beginning of the 20th century, the town began to spread out on the very steep slopes of the valley and urbanisation spread.  Tulle became a garrison town from 1841, when an infantry regiment settled in the former barracks located on the Champ-de-Mars, on the current site of the Cité administrative, along the Corrèze.  From 1917 to 1922, Tulle was in the spotlight of the French press because of a news item. Over 100 anonymous letters were sent, denouncing all the secrets of the inhabitants of the city. The sender was actually Angele Laval, a spurned and insane woman. This fact inspired Clouzot for his film "Le Corbeau" and Cocteau for his play "La Machine à écrire".

World War II.

During the Second World War, the 2nd SS Division Das Reich division of the Waffen SS perpetrated a reprisal of civilians in Tulle, following the killing and maiming of some 40 German soldiers in Tulle on 8 June 1944 by the Maquis resistance movement.  On 9 June 1944 a large number of male civilians were rounded up by the SS. Of these, 97 were randomly selected and then hanged from lamp posts and balconies in the town. Additionally, another 321 captives were sent to forced labour camps in Germany where 101 lost their lives. In total, the actions of the Wehrmacht, the Waffen-SS, and the SD claimed the lives of 213 civilian residents of Tulle.

Since the 1960s.

In the last stages of the Algerian War and its aftermath, four military officers involved in instigating a failed coup aimed at deposing President de Gaulle were held in the prison at Tulle. De Gaulle referred at the time to "those idiotic generals playing ball in Tulle Prison". The four were Raoul Salan, Edmond Jouhaud, Maurice Challe and André Zeller. The last of them to be released was Salan, amnestied on 15 June 1968 in the wake of "The Events" of May 1968.  In 1972, the annex of the Army Technical Teaching School (EETAT) was created in Tulle to train electromechanical engineers, accountants and mechanics. In 1977, an annex of the National Technical School of the Army (ENTSOA) was opened and closed in 1984. It was replaced in 1983 by the Gendarmerie School of Tulle, located in the barracks of La Bachellerie, which today accommodates around 1,100 gendarme students.  "The Day of the Jackal", a 1973 British-French political thriller film directed by Fred Zinnemann and starring Edward Fox and Michael Lonsdale, has large segments of the film set in the Tulle area. Based on the 1971 novel "The Day of the Jackal" by Frederick Forsyth, the film is about a professional assassin known only as the "Jackal" who is hired to assassinate French president Charles de Gaulle in the summer of 1963 and uses the Tulle area and some of its (fictional) people as cover for the preparations for the assassination attempt. Tulle appears both in the story and as the actual filming localities.  Today, Tulle, prefecture of Corrèze and bishopric, is no longer the seat of a weapons factory. Until the 1980s, it had been the largest employer in Limousin, but the state-owned company Giat Industries, now Nexter, has carried out numerous restructurings over the last few decades, reducing the historic Tulle production site to 120 employees. A weapons museum was created in 1979 by the staff of the factory.  Since 1973, the town centre has had a tower, the "Cité administrative" (Administrative City Tower), which has 22 levels and is 86 m high on the river side.  In 1996, Tulle hosted the finish of a stage of the Tour de France starting from Super-Besse (Puy-de-Dôme).  On 6 May 2012, the newly elected president, François Hollande, mayor of Tulle between 2001 and 2008, gave his first speech as President of the French Republic on the Cathedral Square, which was attended by several thousand people, including some 400 French and foreign journalists and several helicopters.

Economy.

Tulle's role as a centre for lace making is highlighted by an "international lace festival" held each August. The town is also home to the Maugein accordion factory, which once employed 200, though this figure is now much reduced. Near to this there was, till recently, a significant armaments manufacturing business, but its site is now (2011) marked only by an armaments museum.  Located in another part of town is a car parts plant owned by the American Borg-Warner company, and employing approximately 300 people.

Government.

Mayors.

Mayors of Tulle since 1949 were:

Politics.

Tulle's MP in the National Assembly of France for nearly 15 years was the Socialist François Hollande, who was elected President of the Republic in 2012. Hollande also served as mayor of the town.

Population.

Demographic trends since 1793

Cultural life.

Sport.

The municipality has established an ambitious policy for sport in the early 2000s, which enabled it in 2008 to become the most sporting town in France. For example, the town has an association football team called Tulle Foot Corrèze who concentrate on youth and first team opportunities.

Media.

Tulle hosts several medias:

International relations.

Tulle is twinned with:

Personalities.

Tulle is the birthplace of:  The following people have resided in Tulle:

Tulle (; ) is a commune in central France. It is the third-largest town in the former region of Limousin and is the capital of the department of Corrèze, in the region of Nouvelle-Aquitaine. Tulle is also the episcopal see of the Roman Catholic Diocese of Tulle.

Tulle [tyl] je město ve Francii. Leží v regionu Nová Akvitánie, ve střední Francii. Je to třetí největší město v regionu po Limoges a Brive-la-Gaillarde.


Location of the TSS.

The TSS may reside anywhere in memory. A segment register called the task register (TR) holds a segment selector that points to a valid TSS segment descriptor which resides in the GDT (a TSS descriptor may not reside in the LDT). Therefore, to use a TSS the following must be done by the operating system kernel:  For security purposes, the TSS should be placed in memory that is accessible only to the kernel.

Task register.

The TR register is a 16-bit register which holds a segment selector for the TSS. It may be loaded through the LTR instruction. LTR is a privileged instruction and acts in a manner similar to other segment register loads. The task register has two parts: a portion visible and accessible by the programmer and an invisible one that is automatically loaded from the TSS descriptor.

Register states.

The TSS may contain saved values of all the x86 registers. This is used for task switching. The operating system may load the TSS with the values of the registers that the new task needs and after executing a hardware task switch (such as with an IRET instruction) the x86 CPU will load the saved values from the TSS into the appropriate registers. Note that some modern operating systems such as Windows and Linux do not use these fields in the TSS as they implement software task switching.  Note that during a hardware task switch, certain fields of the "old" TSS are updated with the CPU's current register contents before the values from the "new" TSS are read. Thus some TSS fields are read/write, while others are read-only:  The codice_22 field is in fact the very first one read out of the new TSS: since a hardware task switch can also switch to a completely different page table mapping, all the other fields (especially the codice_23) are relative to the new mapping.

I/O port permissions.

The TSS contains a 16-bit pointer to I/O port permissions bitmap for the current task. This bitmap, usually set up by the operating system when a task is started, specifies individual ports to which the program should have access. The I/O bitmap is a bit array of port access permissions; if the program has permission to access a port, a "0" is stored at the corresponding bit index, and if the program does not have permission, a "1" is stored there. If the TSS’ segment limit is less than the full bitmap, all missing bits are assumed to be "1".  The feature operates as follows: when a program issues an x86 I/O port instruction such as IN or OUT (see x86 instruction listings - and note that there are byte-, word- and dword-length versions), the hardware will do an I/O privilege level (IOPL) check to see if the program has access to all I/O ports. If the Current Privilege Level (CPL) of the program is numerically greater than the I/O Privilege level (IOPL) (the program is less-privileged than what the IOPL specifies), the program does not have I/O port access to all ports. The hardware will then check the I/O permissions bitmap in the TSS to see if that program can access the specific port(s) in the IN or OUT instruction. If (all the) relevant bit(s) in the I/O port permissions bitmap is/are clear, the program is allowed access to the port(s), and the instruction is allowed to execute. If (any of) the relevant bit(s) is/are set - or if (any of) the bit(s) is/are past the TSS’ segment limit - the program does not have access and the processor generates a general protection fault. This feature allows operating systems to grant selective port access to user programs.

Inner-level stack pointers.

The TSS contains 6 fields for specifying the new stack pointer when a privilege level change happens. The field SS0 contains the stack segment selector for CPL=0, and the field ESP0/RSP0 contains the new ESP/RSP value for CPL=0. When an interrupt happens in protected (32-bit) mode, the x86 CPU will look in the TSS for SS0 and ESP0 and load their values into SS and ESP respectively. This allows for the kernel to use a different stack than the user program, and also have this stack be unique for each user program.  A new feature introduced in the AMD64 extensions is called the Interrupt Stack Table (IST), which also resides in the TSS and contains logical (segment+offset) stack pointers. If an interrupt descriptor table specifies an IST entry to use (there are 8), the processor will load the new stack from the IST instead. This allows known-good stacks to be used in case of serious errors (NMI or Double fault for example). Previously, the entry for the exception or interrupt in the IDT pointed to a task gate, causing the processor to switch to the task that is pointed by the task gate. The original register values were saved in the TSS current at the time the interrupt or exception occurred. The processor then set the registers, including SS:ESP, to a known value specified in the TSS and saved the selector to the previous TSS. The problem here is that hardware task switching is not supported on AMD64.

Previous TSS link.

This is a 16-bit selector which allows linking this TSS with the previous one. This is only used for hardware task switching. See the IA-32 manuals for details.

Use of TSS in Linux.

Although a TSS could be created for each task running on the computer, Linux kernel only creates one TSS for each CPU and uses them for all tasks. This approach was selected as it provides easier portability to other architectures (for example, the AMD64 architecture does not support hardware task switches), and improved performance and flexibility. Linux only uses the I/O port permission bitmap and inner stack features of the TSS; the other features are only needed for hardware task switches, which the Linux kernel does not use.

Exceptions related to the TSS.

The x86 exception vector 10 is called the Invalid TSS exception (#TS). It is issued by the processor whenever something goes wrong with the TSS access. For example, if an interrupt happens in CPL=3 and is transferring control to CPL=0, the TSS is used to extract SS0 and ESP0/RSP0 for the stack switch. If the task register holds a bad TSS selector, a #TS fault will be generated. The Invalid TSS exception should never happen during normal operating system operation and is always related to kernel bugs or hardware failure.  For more details on TSS exceptions, see Volume 3a, Chapter 6 of the IA-32 manual.

TSS in x86-64 mode.

The x86-64 architecture does not support hardware task switches. However the TSS can still be used in a machine running in the 64 bit extended modes. In these modes the TSS is still useful as it stores:  Also, the task register is expanded in these modes to be able to hold a 64-bit base address.

The task state segment (TSS) is a structure on x86-based computers which holds information about a task. It is used by the operating system kernel for task management. Specifically, the following information is stored in the TSS:

Task State Segment (TSS) je segment stavu úlohy. Slouží k uložení kontextu procesoru, kterému je odebráno řízení. Každá úloha má svůj vlastní Task State Segment. Na segment TSS ukazuje popisovač systémového segmentu, který je uložen pouze v GDT (Global Descriptor Table). V registru TR je uložen selektor na TSS úlohy, kterou momentálně zpracovává procesor.