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Fibroblast growth factor 2

Fibroblast growth factor 2 (FGF-2), also known as basic fibroblast growth factor (bFGF) and FGF-β, is a growth factor and signaling protein encoded by the FGF2 gene. It binds to and exerts effects via specific fibroblast growth factor receptor (FGFR) proteins, themselves a family of closely related molecules. Fibroblast growth factor protein was first purified in 1975; soon thereafter three variants were isolated: 'basic FGF' (FGF2); Heparin-binding growth factor-2; and Endothelial cell growth factor-2. Gene sequencing revealed that this group is the same FGF2 protein and is a member of a family of FGF proteins.

Function
Like other FGF family members, basic fibroblast growth factor possesses broad mitogenic and cell survival activities, and is involved in a variety of biological processes, including embryonic development, cell growth, morphogenesis, tissue repair, tumor growth and invasion.

In normal tissue, bFGF is present in basement membranes and in the subendothelial extracellular matrix of blood vessels. It stays membrane-bound as long as there is no signal peptide.

It has been hypothesized that, during both wound healing of normal tissues and tumor development, the action of heparan sulfate-degrading enzymes activates bFGF, thus mediating the formation of new blood vessels, a process known as angiogenesis.

In addition, it is synthesized and secreted by human adipocytes and the concentration of FGF2 correlates with the BMI in blood samples. It was also shown to act on preosteoblasts – in the form of an increased proliferation – after binding to fibroblast growth factor receptor 1 and activating phosphoinositide 3-kinase.

FGF2 has been shown in preliminary animal studies to protect the heart from injury associated with a heart attack, reducing tissue death and promoting improved function after reperfusion.

Evidence has shown that low levels of FGF-2 play a key role in the incidence of excessive anxiety.

Additionally, FGF-2 is a critical component of human embryonic stem cell culture medium; the growth factor is necessary for the cells to remain in an undifferentiated state, although the mechanisms by which it does this are poorly defined. It has been demonstrated to induce gremlin expression which in turn is known to inhibit the induction of differentiation by bone morphogenetic proteins. It is necessary in mouse-feeder cell dependent culture systems, as well as in feeder and serum-free culture systems. FGF-2, in conjunction with BMP4, promote differentiation of stem cells to mesodermal lineages. After differentiation, BMP4 and FGF2 treated cells generally produce higher amounts of osteogenic and chondrogenic differentiation than untreated stem cells. However, a low concentration of bFGF (10 ng/mL) may exert an inhibitory effect on osteoblast differentiation. The nuclear form of FGF2 functions in mRNA export

FGF-2 is synthesized primarily as a 155 amino acid polypeptide, resulting in an 18 kDa protein. However, there are four alternate start codons which provide N-terminal extensions of 41, 46, 55, or 133 amino acids, resulting in proteins of 22 kDa (196 aa total), 22.5 kDa (201 aa total), 24 kDa (210 aa total) and 34 kDa (288 aa total), respectively. Generally, the 155 aa/18 kDa low molecular weight (LMW) form is considered cytoplasmic and can be secreted from the cell, whereas the high molecular weight (HMW) forms are directed to the cell's nucleus.

Since its first isolation from the bovine pituitary, FGF2 has become a prominent signaling protein studied in bovine reproduction. It has been found in cumulus cells that surround the oocyte and evidence on such early reproductive function indicates FGF2 may promote meiotic resumption and prevent cumulus cell apoptosis. FGF2 is also produced by the uterine epithelium, secreted into the lumen, and acts on the developing embryo and conceptus. Work in mice previously established that FGF2 plays a role in primitive endoderm (PE) development. Research with bovine embryos has since noted this same phenomenon. Extended blastocyst cultures with FGF2-supplemented media observed that FGF2 increases PE outgrowths via proliferation. Knockout models of the FGF receptor and its kinase activity appears to alter the cellular expression of NANOG and GATA4 (transcription factors essential for proper cell differentiation and embryonic development), indicating a specific role of FGF2 in PE specification and subsequent blastocyst development rates. Culture media supplemented with combinations of FGF2, EGF and IGF2 have found similar results and indicate that FGF2 may activate the AKT pathway for trophoblastic cell line growth. Together, this showcases the key roles FGF2 plays in bovine embryo development, as similarly described in other mammalian species.

Interactions
Fibroblast growth factor 2 has been shown to interact with casein kinase 2, alpha 1, RPL6, ribosomal protein S19 and API5.

title: Fibroblast growth factor 2


text:
Vestfold Line

The Vestfold Line (Vestfoldbanen) is a 137.79 km railway line which runs between Drammen and Eidanger in Norway. The line connects to the Drammen Line at the northern terminus at Drammen Station and continues as the Bratsberg Line past Skien Station. The line is exclusively used for passenger trains, which are provided by Vy, which connect northwards to Oslo and south-westwards to Grenland. The 13 km section from Eidanger to Skien is often colloquially included in the Vestfold Line.The standard gauge line is electrified at and has twelve remaining stations. The Vestfold Line runs through the coastal region of Vestfold and serves major towns including Holmestrand, Tønsberg, Sandefjord and Larvik, as well as Sandefjord Airport, Torp.

The section to Larvik Station was opened on 13 October 1881 and the remainder, including an extension to Skien Station, opened on 23 November 1882. The line was originally variously known as the Drammen–Skien Line (Drammen–Skienbanen), the County Line (Grevskapsbanen) and the Jarlsberg Line (Jarlsbergbanen), until it became known as the Vestfold Line. Horten was served via the now closed 7 km Horten Line from Skoppum Station. Three other branches were later built: the Brevik Line (1895), the Tønsberg–Eidsfoss Line (1901) and the Holmestrand–Vittingfoss Line (1902). The latter two were private and closed in 1938. The Vestfold Line received gauge conversion from the original narrow gauge in 1949, as the last mainline railway in Norway. It was electrified in 1957.

Since the 1980s there have been plans to upgrade the line to high speed. The first section, at Skoger, opened in 1995. It was followed by a 13 km section past Sande Station in 2001, a passing loop at Nykirke in 2002 and a 7 km section including the Jarlsberg Tunnel in Tønsberg in 2011. In 2016 a new railway through Holmestrand, of which most is in the Holmestrandsporten tunnel, opened. In September 2018 a new double track line between Larvik and Porsgrunn opened, which shortened the travel-time from 33 to 12 minutes.

Route
The Vestfold Line runs from Drammen Station to Eidanger Station, through three counties (Buskerud, Vestfold, and Telemark) and six municipalities (Drammen, Holmestrand, Horten, Tønsberg, Larvik, and Porsgrunn. The line is 137.79 km, of which 24 km is double track. The entire line is electrified, has partial automatic train control and GSM-R. It has 111 level crossings, of which 29 have light and bar. The railway line is owned and maintained by the Norwegian National Rail Administration.

Drammen−Larvik
The route roughly follows the coastline of Oslofjorden whilst, concerning the first section, running from Drammen to Sande inland, bypassing thereby Oslofjords western finger Drammensfjorden. Holmestrandsporten tunnel between Holm i Sande and Nykirke (Horten) was opened in 2016 as part of a double-track high-speed upgrading. South of Nykirke, the route, again, crosses over into Tønsberg Municipality in a hinterland passage. Due to practical reasons (avoidance of a terminus), Tønsberg once got a big loop downtown without horseshoe curve function. The next segment to Larvik via Sandefjord runs inland, but never too far away from Skagerrak coastline. Before Larvik station, Numedalslågen is bridged.

Larvik−Porsgrunn−Skien
In 2018, the original single-track route between Farriselva (Larvik) at lake Farris and Porsgrunn (via Oklungen) was abandoned in favour of a newbuilt double-track high-speed bypass, using several tunnels and not-so-small bridges. Alongside Skienselva, Vestfold Line gets northward to Skien.

Service
Revenue traffic on the line is nearly exclusively provided by Vy as a regional service, numbered RE11. These continue southwards along the Bratsberg Line to Grenland towns of Porsgrunn and Skien and northwards along the Drammen and Asker Line to Oslo and onwards via the Gardermoen Line to Oslo Airport, Gardermoen and the Dovre Line to Lillehammer. Trains operate with a fixed hourly service, with additional trains during rush-hour.

Vy uses Class 70 and 74 electric multiple units on the line. Vy freighted 1.7 million passengers on the line in 2012, making it the busiest regional rail service provided by Vy. Vy provides an included shuttle service from Sandefjord Airport Station to Sandefjord Airport, Torp, which takes four minutes. The Vestfold Line is occasionally used by rerouted freight trains along the Sørlandet Line when that line is closed between Drammen and Nordagutu.

Planning
Public opinion started debating the need for a railway through Vestfold in the late 1860s, when the Randsfjorden Line was built to Drammen, opening in 1868. The parliamentarians from Jarlsberg and Larvik County (renamed Vestfold in 1919) appealed to the government in 1869 for the construction of a railway through Vestfold south from Drammen to Larvik and onwards to Langefjorden. The request was positively accepted by the government, who instructed the railway director to carry out surveys through Vestfold, prioritizing it higher than the surveys through Østfold.

The country experienced an economic boom starting in 1871, with demands throughout the country for railways to be built. Official planning of a railway through Vestfold to Brevik commenced with a royal resolution on 24 July 1871. In addition to providing a regional rail service to Vestfold, a steamship service could be set up from Larvik to Frederikshavn, Denmark. There was also at the time problems with the inner parts of the Oslofjord and the Drammensfjord icing during winter, and access to the ports on the outer fjord would ease the export situation for industry.

There were a multitude of proposals for where the railway should run. The only points of agreement were that the line should run through Tønsberg, Sandefjord and Larvik, and the line between the three towns was the least controversial. North of Tønsberg there was more disunity. One proposal was to run the railway from Vestfossen Station on the Kongsberg Line along the east shore of Eikeren and down to Tønsberg along a route similar to that which the Tønsberg–Eidsfoss Line would later follow. A branch line would then be built to Horten. This alternative allowed the line to run through an area with good access to lumber, which the railway would aid export. The main disadvantage was that the route was 20 km longer than via Sande.

Alternatively a passage through Sande was proposed, although fourteen different routes were proposed. Three main ones were the inner, outer and combined coastal alternatives. The outer followed the shore of the Oslofjord, would be 111 km and would run through Holmestrand, Horten and Åsgårdstrand before reaching Tønsberg. The combined and inner would be 107 and 102 km, respectively, and both involved building a branch line to Horten. A major argument against the coastal route was that the towns already had a good steamship service, with services several daily departures. A third major alternative was to bypass the coast altogether and build a connection from the Kongsberg Line at Skollenborg Station down the valley of Lågendalen to Larvik. The main advantage of this alternative was the large potential for hydroelectricity along Numedalslågen.

Jarlsberg and Larvik County Council and the town councils appointed a railway committee, which asked the county governor on 27 November 1873 to issue shares in the new railway. The county bought shares worth 400,000 Norwegian krone (NOK). Shares for a coastal railway were bought for NOK 4.9 million, twice that of the interior route. The coastal route was expected to pay a dividend of three to four percent, compared to two and a half percent for the interior. Ahead of the county council meeting in December 1873 the county governor recommended that an application be sent to the government without a preferred route, but the majority of the county council's members voted in favor the interior alternative.

At the time the railway was variously referred to as the County Line and the Jarlsberg Line, both named for the historic countship of Jarlsberg. By 1874 the state railway commission had considered the line and had concluded that it should be built with narrow gauge. Only its chair, Professor Broch, voted in favor of standard gauge, and at the same time recommended that the Drammen Line be converted to the wider gauge. The advantage of narrow gauge was that it would cut construction costs by a third. By then the railway director, Carl Abraham Pihl, had concluded in disfavor of the Vestfold Line and had instead wanted to prioritize the Østfold Line. His view was shared by the cabinet. The break-through came when plans to extend the line onwards to Skien were launched. Pihl estimated the 45 km extension to cost NOK 4.5 million, in addition to a possible branch to Brevik.

The construction of the line was considered by Parliament in 1875. A political deal was struck, where representatives from the Vestfold area agreed to support the Voss Line while representatives from Hordaland supported the Jarlsberg Line. The decision, taken on 8 June 1875, was made with 76 against 36 votes, and supported the compromise coastal route with an extension to Skien. The line was budgeted to cost NOK 10.7 million, and shares of NOK 3.25 million had been sold.

Construction
Construction commenced in 1876, under the management of Pihl, Cato Maximilian Guldberg and Jørgen Meinich. The line received a minimum curve radius of 180 m and a maximum gradient of 1:55 (1.8%). The work was attempted halted twice in 1877 by parties issuing complaints. The first stated that the right-of-way should be built in preparation for conversion to standard gauge, the latter was an attempt to stall construction and instead place the route through the interior. Engineer Størmer launched a proposal in 1878 to instead build the line with standard gauge. This was considered by Parliament's Standing Committee on Railways, but voted down with five against four votes. The proposal was voted down in the plenary voting, with only 24 supporting standard gauge.

There were few difficulties building the line in the relatively flat landscape between Drammen and Larvik. The largest challenge was building through Kobbervikdalen. The navvies were uncomfortable building a cutting south of Holmestrand, where the line went through an old cemetery in clay ground and they would often find well-preserved corpses while digging. The section between Larvik and Skien went through considerably more hilly terrain, especially along the shore of Farrisvannet, which included more than twenty tunnels along a section of 15 km. At the peak, in 1879, there were 2,114 people working on the railway construction, receiving an average NOK 2.50 per day in wage.

Because King Oscar II happened to be touring Norway in October 1881, the railway between Drammen and Larvik was officially opened by him on 13 October 1881, including the branch to Horten. However, the construction was not completed and the line did not actually start operations until 7 December. The section from Larvik to Skien was officially opened on 24 November 1882. Construction cost NOK 12 million. The Brevik Line was taken out of the original plans and did not open until 15 October 1895.

Narrow-gauge years
The Vestfold Line was organized as part of the Norwegian State Railways' Drammen District. At first the line was trafficked with two daily combined passenger and freight trains in each direction, in addition to a freight services on weekdays. The most important train was the post train, a combined post and passenger express which departed Oslo West Station at 08 hours and returned from Skien at 15 hours. It used the newest rolling stock Vy had available. At Skoppum there was a corresponding local train to Horten. From the opening of the Brevik Line in 1895, local trains started running between Brevik and Skien, and an additional daily express train was set up run to Brevik, where there was a corresponding steamship service to Kristiansand.

Vy took delivery of five Class V steam locomotives, manufactured by Motala Verkstad and four lager tender Class XI locomotive built by Dübs & Company. The latter were mostly used for the express trains. The first compound locomotive, Class XIII, was taken into use in 1895. The next two were not compound: two Baldwin Locomotive Works locomotives were delivered in 1898. They remained in service until 1908, when they were transferred to the Røros Line. Two Class IX from Swiss Locomotive & Machine Works units were transferred to the Vestfold Line in 1897. Two more Class XIII were delivered in 1900. Two Class XXIIIa locomotives were delivered from Hamar Jernstøperi in 1907 and 1908, with a further ten Class XXIIId units delivered from Thune between 1913 and 1915. The line later received various other steam locomotives as narrow gauge railways were converted to standard gauge.

During construction of a level crossing at Smørstein on 17 August 1918 the area around the track started experiencing a series of landslides. Within a few days the earthwork under the tracks had slid away. Vy hired a steamship to freight passengers and cargo past the effected area, and part of the traffic was freighted across the fjord from Horten to Moss. A temporary line was built close to the mountain, while construction took place of a temporary solution, the Smørstein Tunnel. The temporary line opened on 28 October 1918 and the new segment with a tunnel on 25 May 1921.

The Jarlsberg Line officially changed its name to the Vestfold Line on 1 July 1930. It received thirty-eight new stops in the period between 1928 and 1932.

Gauge conversion
The county council debated conversion of the line to standard gauge in 1910, and issued a request to the government. It considered the question in 1912, and granted funding for preliminary surveys. After petitioning from most municipal councils and various commercial interests in 1913, Parliament agreed to the funding in April 1914. A railway committee was established, and Drammen District proposed that its lines be converted. By the time the issue had reached Parliament in 1923, a conversion of the Vestfold Line had fallen out of the plans. However, several of the surrounding railways were converted to standard gauge.

The Drammen Line was converted to dual gauge between 1917 and 1920, and then only standard gauge from 13 November 1922. The Drammen Line was electrified in two stages, in 1922 and 1930. The Bratsberg Line opened between Notodden and Skien in 1917, and the section of the Vestfold Line from Skien to Eidanger was converted to dual gauge. From 16 June 1921 the line, including the branch to Brevik, was entirely standard gauge. This caused the trains from Skien and Porsgrunn to be re-routed via the Bratsberg Line Kongsvinger to Oslo.

Trains on the Vestfold Line therefore terminated at Drammen, where passengers had to transfer to the Drammen Line. The low standard became a local political concern. The road director proposed closing the railway and building a highway, but the proposal met diminutive support. A propaganda committee was established in 1931, which in addition to gauge conversion insisted on that the line be rebuilt so it run via Horten. Parliament voted in favor on 26 June 1934 of converting the Vestfold Line. However, with the German occupation of Norway between 1940 and 1945, the Vestfold Line received a low priority and was hardly maintained. A new decision to convert the gauge was taken by Parliament in March 1946.

In 1949 there were twenty-one various versions of Class XXIII and two Class XXVI locomotives used on the Vestfold Line. New 25 kilograms per meter track were installed. However, the foundation was not resized to suit standard gauge. Between 170 and 240 men were employed and the works cost NOK 41 million. The gauge-converted railway, including the Horten Line, was taken into use on 3 October 1949. The Vestfold Line was the last railway in Norway to receive gauge conversion. Most of the remaining narrow gauge rolling stock was therefore sold to Sweden.

Electrification
The Bratsberg and Brevik Line were electrified before the Vestfold Line, between 1936 and 1949. Electrification of the Vestfold Line took place in three segments. First the segment from Eidanger to Larvik was taken into use on 15 October 1956, then the segment from Larvik to Tønsberg on 20 May 1957 and finally the segment from Tønsberg to Drammen on 1 December 1957. Vy reallocated most and later all of their El 8 locomotives to Drammen District, resulting in them being frequently used on the Vestfold Line. Class 66 multiple units were introduced on the Vestfold Line on 28 May 1967. They ran on trains to Skien until 3 June 1973, after which it only served to Larvik. They were retired on 21 May 1977. El 11 locomotives were used on the Vestfold Line from the 1970s. From the late 1970s and early 1980s, these were replaced with El 13.

Centralized traffic control was introduced in steps during the early 1970s. The section from Drammen to Holmestrand received it on 16 December 1970, the section onwards to Tønsberg on 1 July 1971, the section onwards to Sandefjord on 15 September 1971, the section onwards to Larvik on 27 October 1971, the section onwards to Porsgrunn on 16 December 1971. The port tracks in Holmestrand and Tønsberg were closed in 1980.

A major change to the service on the Vestfold Line took place on 29 May 1978, when all smaller stations were closed. Vy introduced its new InterCityExpress concept, which resulted in an increase of patronage by twenty-five percent on the Vestfold Line. From 30 May 1980 the Oslo Tunnel opened, and trains from the Vestfold Line could terminate at Oslo East Station and continue onwards to Lillehammer. The same year a commuter association was started for the Vestfold Line. With the delivery of new B5 carriages, Vy was able to put additional B3 carriages in to use on the Vestfold Line. Automatic train stop was installed from Drammen to Larvik on 18 July 1990 and from Larvik to Skien on 28 November 1991.

High-speed
The first stages of modernization of the Vestfold Line were carried out through a combination of new trains and sections of double track. Vy ordered of the Class 70 trains for their InterCityExpress services in 1988. Capable of speeds of 160 km/h, they were introduced on the Vestfold Line in 1992. The new trains increased capacity on the Vestfold Line with 2,100 seats per day. Vy soon found that the four-car trains had an unsuitable size: a single unit did not provide sufficient capacity while two units provided too much capacity. Despite the upgrades, by 1997 the trains from Larvik to Oslo were using twenty minutes longer than they were in 1973, and the average speed on the Vestfold Line was down to 65 km/h.

Starting work in 1993, the first two section of the Vestfold Line to be upgraded were a 4.5 km double track segment from Kobbervikdalen to Skoger, and a 12.5 km segment from Åshaugen via a new Sande Station to Holm. The Skoger section opened in on 17 October 1995, while the section past Sande did not open until 23 October 2001. Part of the reason for five-year delay with the second segment was delays with the installation of the signaling system which was being carried out by Adtranz.

In September 1999, the government presented their proposal for National Transport Plan 2002–11, which included three segments on the Vestfold Line: Holm–Nykirke, Barkåker–Tønsberg and Farriseidet–Porsgrunn. When Parliament passed the plan in February 2001, the Barkåker–Tønsberg segment was prioritized second on the Vestfold Line, after a new passing loop at Nykirke. The passing loop was completed in 2002, the same year as all traffic on the Horten Line was terminated. Råstad Station reopened as Sandefjord Airport Station on 21 January 2007, serving Sandefjord Airport, Torp. This allowed the Vestfold Line to act as an airport rail link to Sandefjord Airport, Torp, which had during the 1990s grown as both a regional airport and as a low-cost airport for Ryanair.

National Transport Plan 2002–11 proposed that construction start in 2005, but by November 2002, the National Rail Administration delayed the plans, following investment cuts by Bondevik's Second Cabinet. In response, Minister of Transport Torild Skogsholm stated that she was considering financing the project as a public–private partnership paid through a surcharge on tickets fares. Increased funding to railways commenced with the appointment of Stoltenberg's Second Cabinet in 2005. The go-ahead for the 7.7 km Barkåker–Tønsberg section, including the Jarlsberg Tunnel, was given by Minister of Transport Liv Signe Navarsete on 31 March 2008, estimated to cost 1.37 billion Norwegian krone (NOK).

The plan to make an isolated investment in the Barkåker–Tønsberg section was criticized by several pro-railway interest organizations, including Vy, which instead recommended that the National Rail Administration place the investments on hold until more of the Vestfold Line was planned. The short segment gives little operational advantages, while hindering a new line from running via the population centers of Horten, Åsgårdstrand and Eik. Construction of the project started on 16 March 2009, and opened on schedule on 7 November 2011. By then Vy had taken delivery of its new Class 74 units, which were put into service on the Vestfold Line. During trial runs a Class 74 unit derailed at Nykirke. The train was totaled, although no-one was seriously injured in the incident.

Architecture
Balthazar Lange was selected as the line's main architect, although some minor buildings were standardized designs by Peter Andreas Blix. Lange worked on the various plans from late 1879 until July 1882, when he retired as a railway architect. He first designed three similar, town stations: Holmestrand, Sandefjord and Porsgrunn. Designed in Swiss chalet style, they each featured gablets in each end, on both the track and town side. The ends were more anonymous. The design gave a non-symmetrical feel around the end axis, with the town side appearing in two stories and the track side as one and a half. Holmestrand and Sandefjord have both been extensively rebuilt. The stations were smaller and cheaper with resemblance of Blix' contemporary Moss Station and Fredrikstad Station on the Østfold Line, across the fjord.

The only brick stations were Tønsberg Station and Larvik Station, designed in Historicism and Renaissance Revival. In addition to these stations' size, it was decisive that local building restrictions banned wooden buildings. The two stations had the same floor plan and design, but Larvik was slightly longer. Their design was inspired from the main farmhouses of Jarlsberg and Larvik. The stations were innovative for their design with a central vestibule with direct access to both the town and track sides, with branches to waiting rooms for second and third class. They were also innovative in that the upper floor, with the station-master's residence, was smaller than the ground floor.

Skoppum Station, where the Horten Line branched off, was given an island platform design, with the station located between the two tracks. This, and the need for space for transshipment, gave the station an odd design, and the island location gave it difficult access from the surroundings. Six stations have been listed by the Directorate for Cultural Heritage: Skoppum, Tønsberg, Stokke, Råstad, the goods house at Sandefjord, the engine shed at Larvik Station, Eidanger Station and Borgestad Station.

Future
The Vestfold Line is part of the Intercity Triangle, which the authorities wish to prioritize for future upgrades. The long-term goal is to construct a continuous high-speed double track from Oslo to Skien. This is in part a response to the E18 being upgraded to a motorway. In addition to increased speeds, the current line does not allow for more trains to operate. Plans call for an initial construction of the Inner Intercity Triangle, which will give continual double track from Tønsberg to Oslo, in addition to the shortening of the segment between Larvik and Porsgrunn. This will allow travel time from Tønsberg to Oslo to be reduced from 1 hour and 28 minutes to 1 hour. An upgrade of the rest of the line, scheduled for completion by 2030, will cut travel time from Porsgrunn to Oslo from 2 hours and 45 minutes to 1 hour and 36 minutes. The line could accommodate an estimated 9.5 million passengers per year, and each station could receive between 100 and 500 percent increase in patronage. Despite the plans for the upgrades of the Vestfold Line, there are no current plans for upgrading the 15 km line and tunnel between Asker and Drammen, which all trains must follow to Oslo and which has a maximum speed of 130 km/h.

Construction of the 14.1 km section of double track between Holm and Nykirke commenced on 16 August 2010. The segment will connect the passing loop at Nykirke and the double-tracked segment through Sande, giving a combined length of 32 km of high-speed double track. Designed for speeds of 250 km/h, the new segment will feature the 12.3 km Holmestrandfjellet Tunnel, which will contain the four-track Holmestrand Station. The segment is estimated to cost NOK 5.7 billion and is scheduled for completion in 2016.

The 35 km section of railway which runs between Farriseidet and Porsgrunn is in the process of being replaced with a new, high-speed 23.5 km section. It will reduce travel time between Larvik Station and Porsgrunn Station from 34 to 12 minutes. Originally planned as single track with two passing loops, it was upped to double track with surveys showing increased traffic should the Sørlandet Line be connected to the Vestfold Line with the construction of a proposed Grenland Line. The segment includes seven tunnels with a combined length of 14.5 km and five bridges. Municipal zoning of the segment was passed in July 2010, with construction commencing in September 2012. Construction is estimated to cost NOK 5.3 billion and is scheduled for completion in 2018.

There are proposals to connect the Vestfold Line with the Sørlandet Line via a new Grenland Line. It would connect to the Vestfold Line just north of Porsgrunn Station and would run 59 km from Porsgrunn to Skorstøl on the Sørlandet Line. The line is estimated to cost NOK 20-26 billion and would allow the travel time from Kragerø to Oslo of 2 hours and from Kristiansand to Oslo in 3 hours and 23 minutes. Passenger trains along the Sørlandet Line, and possibly freight trains, would be routed via the Vestfold Line. It is therefore necessary to complete the upgrade of the Vestfold Line before the Grenland Line is opened.

There are plans to build a new road crossing of the Oslofjord between Horten and Moss, which would replace the Moss–Horten Ferry. It could include a connection of the Vestfold Line with the Østfold Line. One alternative was a suspension bridge across Drøbaksundet, which could be built to accommodate trains and feature a main span of 1300 and 1500 m. A bridge or tunnel crossing further south would require more advanced technology and presumably consist of combination of various bridge technologies, including as a pontoon bridge or a submerged floating tunnel.

The Norwegian National Transport Plan for 2018-2029 states that one of the priorities for the railway system is to establish a continuous double track between Oslo and Tønsberg by the end of 2024, and a completed double track all the way to Skien in 2032.

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/

title: Vestfold Line


text:
Lezo, Aklan

Lezo, officially the Municipality of Lezo (Aklanon: Banwa it Lezo; Hiligaynon: Banwa sang Lezo; Bayan ng Lezo), is a 5th class municipality in the province of Aklan, Philippines. It is the smallest municipality in the province both by population and by land area, and even by revenue. According to the 2020 census, it has a population of 15,639 people.

History
Before its creation into an independent municipality, Lezo was a barrio in Kalibo called Guicod derived from the word "Guicab" which means "a cavern in a creek where eels were in abundance", and was also known as Tierra Alta meaning a "high land" because the town center was not inundated during the great flood of the early 19th century.

When the Americans came in 1899, the military government appointed Felix Kimpo as head of the Calivo (covering the present territory of Kalibo, Numancia and Lezo). During the election in 1901 he was elected as the president from 1901 to 1903. At that time there were 34 towns in the province of Capiz, but these were reduced to 24 towns by a law passed by the civil Commission when it was found out that some towns were incapable of meeting their financial obligations and maintenance. So on April 4, 1903, through Act No. 720 of the Philippine Commission, Lezo, along with Numancia, and Banga was annexed to Kalibo for decreased of revenue collections.

On July 31, 1909, the civil commission issued Executive Order No. 58 separating Lezo (that includes Numancia) from Kalibo and making Lezo as the seat of government. Numancia then, became a barrio of Lezo. On December 31, 1916, through Act No. 2657, Lezo was part of the second district of the province of Capiz. On March 10, 1917, through Act No. 2711 Lezo was part of the third district of Capiz. In 1920 the situation was reversed with regards to the status of Lezo and Numancia. By Executive Order No. 17, series of 1920, the seat of government was transferred to Numancia and Lezo became a barrio of Numancia.

With several petitions by the residents over the years to separate from Numancia, President Manuel Quezon signed Executive Order No. 364 dated August 28, 1941 converting Lezo into an independent municipality. The inauguration of Lezo as a separate municipality was scheduled in 1942, but due to the outbreak of World War II it was deferred to January 1, 1945.

Geography
Lezo is located at °N, °W. It is 11 km from the provincial capital Kalibo.

According to the Philippine Statistics Authority, the municipality has a land area of 23.40 km2 constituting NaN% of the 1,821.42 km2 total area of Aklan.

Barangays
Lezo is politically subdivided into 12 barangays. Each barangay consists of puroks and some have sitios.

Demographics
In the 2020 census, Lezo had a population of 15,639. The population density was undefined PD/km2.

title: Lezo, Aklan


text:
Dermatophyllum

Dermatophyllum is a genus of three or four species of shrubs and small trees in the family Fabaceae. The genus is native to southwestern North America from western Texas to New Mexico and Arizona in the United States, and south through Chihuahua, Coahuila, and Nuevo León in northern Mexico. Members of the genus are commonly known as mescalbean, mescal bean, or frijolito. One of the common names of Dermatophyllum secundiflorum is Texas mountain laurel, although the name mountain laurel also refers to the very dissimilar and unrelated genus Kalmia (family Ericaceae) and the name laurel refers generally to plants in the unrelated order Laurales. Dermatophyllum secundiflorum is one of the most abundant woody species in the Texas Hill Country or Edwards Plateau.

Although still commonly treated in the genus Sophora, recent genetic evidence has shown that the mescalbeans are only distantly related to the other species of Sophora.

Species
Dermatophyllum comprises the following species:
 * Dermatophyllum arizonicum (S.Watson) Vincent —Arizona mescalbean (Arizona, Chihuahua)
 * subsp. arizonicum (S.Watson) Vincent
 * subsp. formosum (Kearney & Peebles) Vincent (Arizona)
 * Dermatophyllum gypsophilum (B.L. Turner & A.M. Powell) Vincent —Guadalupe mescalbean (southern New Mexico, western Texas, Coahuila)
 * subsp. guadalupense (B.L.Turner & A.M.Powell) Vincent
 * subsp. gypsophilum
 * Dermatophyllum juanhintonianum (B.L. Turner) B.L. Turner
 * Dermatophyllum purpusii (Brandegee) Vincent

 * Dermatophyllum secundiflorum (Ortega) Gandhi & Reveal —Texas mescalbean (Texas, New Mexico, Coahuila, Nuevo León)

Description
Dermatophyllum spp. grow to 1 - 11 m tall, with a trunk up to 20 cm in diameter, often growing in dense thickets that grow from basal shoots. The leaves are evergreen, leathery, 6 - 15 cm long, pinnate with 5-11 oval leaflets, 2 - 5 cm long and 1 - 3 cm broad. The flowers, produced in spring, are fragrant, purple, typical pea-flower in shape, borne in erect or spreading racemes 4 - 10 cm long. The fruit is a hard, woody seedpod 2 - 15 cm long, containing one to six oval, bright red seeds 1 - 1.5 cm long and 1 cm in diameter.

All parts of the mescalbeans are very poisonous, containing the alkaloid cytisine (not mescaline, as suggested by the name). Nevertheless, evidence exists of the seeds of the plant having been used in a ritualistic context as a hallucinogen (or more accurately; an ordeal poison) by some Native American peoples. The symptoms of cytisine poisoning are very unpleasant. This has led to speculation that the peyote cult may have developed as a relatively safe substitute for the potentially toxic mescalbean, given the close parallels in performance and divination between the two (including leaders of Plains Indian peyote rituals wearing a necklace of mescalbeans).

title: Dermatophyllum


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Libacao

Libacao, officially the Municipality of Libacao (Aklanon: Banwa it Libacao; Hiligaynon: Banwa sang Libacao; Bayan ng Libacao), is a 3rd class municipality in the province of Aklan, Philippines. According to the 2020 census, it has a population of 28,272 people.

In 1948, the arrabal of Madalag was separated from Libacao and constituted as a separate town, with the following barrios: Logohon, Singay, Balactasan, Cabangahan, Cabilawan, Pangitan, San Jose, Talimagao, Talangban, Alaminos, Catabana, Bakyang, Calicia, Mercedes, Maria Cristina, Dit-ana, Guinato-an, Tigbauan, Alas-as, Mamba, Medina, Panipiason, and Paningayan.

Geography
Libacao is located at °N, °W. It is 31 km from the provincial capital Kalibo.

According to the Philippine Statistics Authority, the municipality has a land area of 254.98 km2 constituting NaN% of the 1,821.42 km2 total area of Aklan.

Barangays
Libacao is politically subdivided into 24 barangays. Each barangay consists of puroks and some have sitios.

Demographics
In the 2020 census, Libacao had a population of 28,272. The population density was undefined PD/km2.

Tourism

 * Nasuraan Falls and
 * Kaeabnakan Falls — located in the remote barangay of Oyang. Nasuraan Falls is a 30 minutes ride and an hour trek from the main sitio.
 * Mangayaw Falls - located at Sitio Mayubay, Guadalupe, Libacao | nearest falls from Poblacion (No entrance fee)
 * Taroytoy — eyed to be the Summer Capital of Central Philippines.
 * Philippine Spotted Deer — a nocturnal and endangered species of deer located primarily in the rainforests of the Visayan islands of Panay and Negros though it once roamed other islands such as Cebu, Guimaras, Leyte, Masbate, and Samar.
 * Libacao Wild River — longest Wild River in the Philippines.
 * Libacao Wild River — longest Wild River in the Philippines.

Products Adventures
 * Coconut - Libacao has a lot of mountains and plains which are suitable for coconuts.
 * Abaca - Abaca fiber is also another product that Libacaonons produce.
 * Bamboo Raft Parade (BAESA PARADA) - a bamboo cruise parade in Aklan River showcasing the local lifestyle, livelihood, culture, and products of Libacao

title: Libacao


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Xellent Swiss Vodka

Xellent Swiss Vodka is a rye vodka distilled in Switzerland.

Presentation
Xellent Swiss vodka is made with bread quality rye and Titlis Glacier Water. This rye is a blend of matador and picasso ryes created to grow in the alps of Switzerland. It is triple distilled in pot stills to over 96% purity. This brand is available in over 22 countries including the United States. This brand is packaged in a bottle reminiscent of the old cocktail shakers. It is red with white letters - using the colors of the Swiss Flag. The brand has won numerous awards including a Double Gold from the San Francisco Spirits Competition and a 96-100 rating from F. Paul Pacult's Spirit Journal. It was also rated as the only vodka in the top 10 of the top 110 spirits for 2005 by Pacult's Spirit Journal.

authors: Я сошла с ума

title: Xellent Swiss Vodka


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Madalag

Madalag, officially the Municipality of Madalag (Aklanon: Banwa it Madalag; Hiligaynon: Banwa sang Madalag; Bayan ng Madalag), is a 4th class municipality in the province of Aklan, Philippines. It is Aklan's largest municipality by land area and also the most sparsely populated. According to the 2020 census, it has a population of 18,890 people.

Madalag was formerly an arrabal and part of Libacao. In 1948, it was separated and constituted as a separate town, with the following barrios: Logohon, Singay, Balactasan, Cabangahan, Cabilawan, Pangitan, San Jose, Talimagao, Talangban, Alaminos, Catabana, Bakyang, Calicia, Mercedes, Maria Cristina, Dit-ana, Guinato-an, Tigbauan, Alas-as, Mamba, Medina, Panikyason, and Paningayan.

Geography
According to the Philippine Statistics Authority, the municipality has a land area of 269.6 km2 constituting NaN% of the 1,821.42 km2 total area of Aklan.

Madalag is situated in the south-central section of the province, bounded on the east by Balete, west by the Province of Antique, north by Malinao and Banga, and south by Libacao. It is 192 km away from regional capital, Iloilo City, and 34 km south from the provincial capital Kalibo.

Soil
There are four varied soil types found in the municipality. They are the San Miguel Clay Loam, Alimodian clay loam, Sapcan clay and Sigcay clay. San Miguel clay is found in barangay Panipiason and Medina. Alimodian clay is found in barangay San Jose, Ma. Cristina and Galicia. Sapian clay is found in the barangay of Mercedes, Bacyang and Alaminos. Sigcay clay is found in the Poblacion, Logohon and Cabilawan.

Land Use
Some 7,717.0251 ha or 28.80% of Madalag land area is planted with high value crops leaving only about 17,772.1917 ha (66.35) as timber land and 24.6342 ha or .09% are utilized as dwelling areas majority of which are in the Poblacion.

Climate
Madalag has a Type III climate which is relatively dry from March to May and wet for the rest of the year.

Barangays
Madalag is politically subdivided into 25 barangays. Each barangay consists of puroks and some have sitios.

Demographics
In the 2020 census, Madalag had a population of 18,890. The population density was undefined PD/km2.

Madalag being predominantly a rural community has a slow growing population. It had a total population of 17,889 persons in 2007, a reduction of .05 percent or 897 persons from the 1995 population, basically due to migration towards industrial and trade centers of the country such as Manila, Cebu, Iloilo and other highly urbanized provinces and municipalities.

The municipality has twenty-five component barangays with two barangays, Poblacion and Alaminos as urban area and the twenty-three remaining barangays as rural areas. Barangay Poblacion is the most populous with 1,775 residents, followed by Panipiason (1,484 residents) and Alaminos (1,257).

Agriculture
Madalag basically has an agricultural economy. Some 7,717.0251 ha of the municipality land is devoted to agriculture. Farming and home industries are the main source of livelihood among the people. Rice is grown in almost all the twenty five (25) barangays. Corn is also planted in some upland areas. Other crops are in pineapple, camote and ube. The municipality also produces fruit trees, like lanzones, rambutan, marang and commercial crops such as coconut and abaca.

The hilly and mountainous areas produce high valued forest products such as narra, acacia, and mahogany and minor product like buri, rattan, bamboo, nipa sap and firewood.

Industry
The center of commercial activities in Madalag is situated along the 1.50 km stretch of Navarette Street and at the Madalag Public Market located in the Poblacion.

The municipality has 93 commercials establishment dominated by the sari-sari stores (37 or 39%). The others establishment (26 or 28.60%) serve as outlet for bakery, carinderias and other recreational services.

Communication
The communication system is operated by mobile signals distributed by Smart, Globe and Dito, while the postal system is managed by the Philippine Postal Corporation. The post office is managed by a postal master, and a mail sorter/carrier. There are no mail distribution and collection centers in the barangays, hence the residents go to the Poblacion to post or receive their mails.

Power and energy
There are 100 households in the barangay Poblacion of Madalag served by electricity with only 5 percent of households not served by power. The remaining twenty-four have electrical power.

Transportation
The total length of all roads types within the geographical boundaries of the municipality is 38.50 km in 2011. Of these lengths, ten percent are paved. A total of fifty percent of the road surface is earth fill while thirty percent is gravel surface. All barangays are accessible by roads except, Medina and Panipiason, that cannot be reach by four wheel vehicle. Generally, the barangays connected to the national road have better road condition compared to the interior barangays.

Water system
Water is supplied by the Poblacion Water District and Poblacion Spring Development. The other barangays are dependent from their Spring Development and artesian and shallow wells.

Healthcare
Madalag has one rural health unit (RHU) and one municipal hospital (Don Leovigildo N. Diapo Sr Memorial Hospital).

Education
Madalag has 21 primary and 8 elementary schools with a total enrollment of 2,927 pupils and 108 teachers. It has three secondary public schools with a total enrollment of 1,368 students and 43 teachers.

title: Madalag


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Makato

Makato, officially the Municipality of Makato (Aklanon: Banwa it Makato; Hiligaynon: Banwa sang Makato; Bayan ng Makato), is a 4th class municipality in the province of Aklan, Philippines. According to the 2020 census, it has a population of 29,717 people.

Established in the thirteenth century, the town’s name had been acquired by accident. Thinking that the Spaniards came to ask the route along the river, the native answered “Makato” which meant “that way”. The Spaniards recorded the name Makato in 1800, thinking it was the name of the town. In 1901, the town merged with Tangalan to form the new municipality of Taft, named after the then Governor-General of the Philippines and future United States President, William Howard Taft. But in 1923, Representative Manuel Terencio of Capiz's now-obsolete 3rd district, authored a law restoring its former name. In 1948, the arrabal of Tangalan, comprising the barrios of Tondog, Jawili, Dumatad, Afga, Baybay, Dapdap, Pudyot, Tagas, Tamalagon, Panayakan, Vivo, Lanipga, Napatag and Tamoko, was separated from Makato to form the municipality of Tangalan.

Geography
Makato is located at °N, °W. It is 8 km from Kalibo, the provincial capital.

According to the Philippine Statistics Authority, the municipality has a land area of 64.60 km2 constituting NaN% of the 1,821.42 km2 total area of Aklan.

Barangays
Makato is politically subdivided into 18 barangays. Each barangay consists of puroks and some have sitios.

Demographics
In the 2020 census, Makato had a population of 29,717. The population density was undefined PD/km2.

Religion

Domicile of the Santo Niño and Ati-atihan Festival known throughout the province and a week ahead of Kalibo, Makato has been celebrating the “Mother of all Philippine Festivals” in admiration of the Holy Child.

Elected officials
Mayor: Ramon Anselmo Martin D. Legaspi III

Vice Mayor: Leoncito Y. Mationg

Sangguniang Bayan Members:
 * Nilo M. Amboboyog
 * Marlene Mae Blaire T. Igham
 * Nerli F. dela Cena
 * Randy R. Vargas
 * Rhine I. Roldan
 * Abencio Honeyboy P. Torres III
 * Leoncito Y. Mationg
 * Steven M. Tejada

Liga ng Barangay (LnB): Bobby Clyde Legaspi

Sangguniang Kabataan Federation: Dina Mae Taladro

Infrastructure
The Aklan Sports Complex, opened in 2010, is located here in Makato. It hosted the 2010 Western Visayas Regional Athletic Association (WVRAA) Meet.

title: Makato


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Malay, Aklan

Malay, officially the Municipality of Malay (Aklanon: Banwa it Malay; Hiligaynon: Banwa sang Malay; Bayan ng Malay), is a 1st class municipality in the province of Aklan, Philippines. It is the richest municipality in the province in terms of revenue. According to the 2020 census, it has a population of 60,077 people, making it the second most populous municipality in Aklan. It is the northernmost town on the island of Panay and the youngest amongst all municipalities in Aklan province. The resort island of Boracay is part of the municipality.

History
The municipality of Malay was created on June 15, 1949, through Republic Act No. 381 and the help of Claro Tumaob, out of various portions of the municipality of Buruanga, then part of Capiz. It included the following barangays: Malay (poblacion, seat of local government), Dumlog, Cabulihan, Balusbos, Nabaoy, Cubay Norte, Cubay Sur, Cogon, Argao, Sambiray, Caticlan, Manoc-Manoc, Balabag, Yapak, Motag, Napaan, and Naasog. On April 25, 1956, Malay became part of the newly-created province of Aklan, along with several other towns of Capiz.

It was hit severely by typhoon Seniang on December 9–10, 2006, with much destruction and damage of homes and infrastructure.

Cityhood
In 2010, a resolution created an ad hoc committee and technical working group to conduct initial study and evaluation for the proposed cityhood of the municipality of Malay, Aklan.

In 2021, the Aklan Provincial Board passed a resolution urging legislative action to change the local government classification of Malay from first-class municipality to chartered city.

On November 28, 2022, House Bill No. 6401 was filed by Rep Teodorico Haresco Jr which seeks accomplish this.

Geography
Malay is located at °N, °W. It is 72 km west of the provincial capital Kalibo, 230 km from Iloilo City, 158 km from Roxas City, and 168 km from San Jose de Buenavista.

According to the Philippine Statistics Authority, the municipality has a land area of 66.01 km2 constituting NaN% of the 1,821.42 km2 total area of Aklan.

Barangays
Malay is politically subdivided into 17 barangays. Each barangay consists of puroks and some have sitios.

There are 3 barangays (Balabag, Manoc-Manoc, and Yapak) of which situated within Boracay Island, while the rest are in mainland Malay.

Demographics
In the 2020 census, Malay had a population of 60,077. The population density was undefined PD/km2.

Economy
Because of its robust tourism industry, the municipality is now considered as having the strongest economy in all the municipalities in the Region and the richest municipality of Aklan in terms of income and annual budget. The tourism industry of Boracay became the catalyst of its economic growth that brought many investors to come and helped transform the municipality into a cosmopolitan area.

Banks
, there are ten (10) banks in the municipality of Malay operated by six (6) commercial banking corporations.

Air
Malay has one airport, officially named Godofredo P. Ramos Airport but more popularly known as Caticlan Airport. Only small aircraft were allowed to land on the 950 m runway. The runway was extended to 1800 m in 2016, allowing bigger aircraft like the Airbus A320 to land at the airport.

Sea
The Caticlan Jetty Port, one of the ports along the Strong Republic Nautical Highway, serves as a gateway to Boracay island, Roxas, Oriental Mindoro, and Bulalacao, Oriental Mindoro The Tabon port is not used a lot but it is used if its not summer.

Ground Transportation
Malay uses the electrics Sikad in Boracay island

Bus
Malay is also using the hop on hop off shuttle service in boracay island

Education

 * List of schools in Malay

Elementary

 * Argao Elementary School
 * Balabag Elementary School
 * Caticlan Elementary School
 * Cubay Elementary School
 * Kabulihan-Dumlog Elementary School
 * Naasog Elementary School
 * Nabaoy Elementary School
 * Napaan Elementary School
 * Manocmanoc Elementary School
 * Malay Elementary School
 * Sambiray Primary School
 * Yapak Elementary School

Secondary

 * Boracay National High School
 * Boracay National High School Manoc-Manoc Extension
 * Caticlan Academy Foundation, Inc
 * Lamberto H. Tirol National High School
 * Malay National High School

Healthcare
Malay is being served by three hospitals, of which 1 is private, and 2 are owned by the government.
 * Don Ciriaco Tirol Memorial Hospital
 * Malay Municipal Hospital
 * Aklan Baptist Hospital

FM Radio Stations

 * Radyo Todo Aklan 88.5 (Philippine Broadcasting Service/Todo Media, Inc.)
 * 89.7 DYIE FM (Far East Broadcasting Company)
 * 91.1 Yes the Best (Manila Broadcasting Company/Philippine Broadcasting Corporation)
 * 93.5 Easy Rock (Manila Broadcasting Company/Cebu Broadcasting Company)
 * 94.9 Brigada News FM (Brigada Mass Media Corporation)
 * 97.3 Boracay Beach Radio (Interactive Broadcast Media)
 * 98.1 iFM (Radio Mindanao Network)
 * 106.1 FM2 Boracay (Philippine Broadcasting Service/One Media Boracay)

Cable Television

 * Kalibo Cable TV Network
 * Paradise Cable TV

title: Malay, Aklan


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Quantum tomography

Quantum tomography or quantum state tomography is the process by which a quantum state is reconstructed using measurements on an ensemble of identical quantum states. The source of these states may be any device or system which prepares quantum states either consistently into quantum pure states or otherwise into general mixed states. To be able to uniquely identify the state, the measurements must be tomographically complete. That is, the measured operators must form an operator basis on the Hilbert space of the system, providing all the information about the state. Such a set of observations is sometimes called a quorum. The term tomography was first used in the quantum physics literature in a 1993 paper introducing experimental optical homodyne tomography.

In quantum process tomography on the other hand, known quantum states are used to probe a quantum process to find out how the process can be described. Similarly, quantum measurement tomography works to find out what measurement is being performed. Whereas, randomized benchmarking scalably obtains a figure of merit of the overlap between the error prone physical quantum process and its ideal counterpart.

The general principle behind quantum state tomography is that by repeatedly performing many different measurements on quantum systems described by identical density matrices, frequency counts can be used to infer probabilities, and these probabilities are combined with Born's rule to determine a density matrix which fits the best with the observations.

This can be easily understood by making a classical analogy. Consider a harmonic oscillator (e.g. a pendulum). The position and momentum of the oscillator at any given point can be measured and therefore the motion can be completely described by the phase space. This is shown in figure 1. By performing this measurement for a large number of identical oscillators we get a probability distribution in the phase space (figure 2). This distribution can be normalized (the oscillator at a given time has to be somewhere) and the distribution must be non-negative. So we have retrieved a function $$W(x,p)$$ which gives a description of the chance of finding the particle at a given point with a given momentum. For quantum mechanical particles the same can be done. The only difference is that the Heisenberg's uncertainty principle mustn't be violated, meaning that we cannot measure the particle's momentum and position at the same time. The particle's momentum and its position are called quadratures (see Optical phase space for more information) in quantum related states. By measuring one of the quadratures of a large number of identical quantum states will give us a probability density corresponding to that particular quadrature. This is called the marginal distribution, $$\mathrm{pr}(X)$$ or $$\mathrm{pr}(P)$$ (see figure 3). In the following text we will see that this probability density is needed to characterize the particle's quantum state, which is the whole point of quantum tomography.

What quantum state tomography is used for
Quantum tomography is applied on a source of systems, to determine the quantum state of the output of that source. Unlike a measurement on a single system, which determines the system's current state after the measurement (in general, the act of making a measurement alters the quantum state), quantum tomography works to determine the state(s) prior to the measurements.

Quantum tomography can be used for characterizing optical signals, including measuring the signal gain and loss of optical devices, as well as in quantum computing and quantum information theory to reliably determine the actual states of the qubits. One can imagine a situation in which a person Bob prepares many identical objects (particles or fields) in the same quantum states and then gives them to Alice to measure. Not confident with Bob's description of the state, Alice may wish to do quantum tomography to classify the state herself.

Linear inversion
Using Born's rule, one can derive the simplest form of quantum tomography. Generally, being in a pure state is not known in advance, and a state may be mixed. In this case, many different types of measurements will have to be performed, many times each. To fully reconstruct the density matrix for a mixed state in a finite-dimensional Hilbert space, the following technique may be used.

Born's rule states $$\mathrm{P}(E_i | \rho) = \mathrm{Trace}(E_i \rho)$$, where $$E_i$$ is a particular measurement outcome projector and $$\rho$$ is the density matrix of the system. Given a histogram of observations for each measurement, one has an approximation $$p_i$$ to $$\mathrm{P}(E_i | \rho)$$ for each $$E_i$$.

Given linear operators $$S$$ and $$T$$, define the inner product
 * $$S \cdot T = \mathrm{Tr}[S^\dagger T] = \vec{S}^\dagger \vec{T}$$

where $$\vec{T}$$ is representation of the $$T$$ operator as a column vector and $$\vec{S}^\dagger$$ a row vector such that $$\vec{S}^\dagger \vec{T}$$ is the inner product in $$\mathbb{C}^d$$ of the two.

Define the matrix $$A$$ as
 * $$A = \begin{pmatrix} \vec E_1^\dagger \\ \vec E_2^\dagger \\ \vec E_3^\dagger \\ \vdots \end{pmatrix}$$.

Here Ei is some fixed list of individual measurements (with binary outcomes), and A does all the measurements at once.

Then applying this to $$\vec{\rho}$$ yields the probabilities:
 * $$A\vec{\rho} = \begin{pmatrix} \vec{E}_1^\dagger \vec\rho \\ \vec{E}_2^\dagger \vec\rho \\ \vec{E}_3^\dagger \vec\rho \\ \vdots \end{pmatrix} = \begin{pmatrix} E_1 \cdot \rho \\ E_2 \cdot \rho  \\ E_3 \cdot \rho \\ \vdots \end{pmatrix} = \begin{pmatrix} \mathrm{P}(E_1 | \rho) \\ \mathrm{P}(E_2 | \rho)  \\ \mathrm{P}(E_3 | \rho) \\ \vdots \end{pmatrix} \approx \begin{pmatrix} p_1 \\ p_2  \\ p_3 \\ \vdots \end{pmatrix} = \vec{p}$$.

Linear inversion corresponds to inverting this system using the observed relative frequencies $$\vec p$$ to derive $$\vec \rho$$ (which is isomorphic to $$\displaystyle\rho$$).

This system is not going to be square in general, as for each measurement being made there will generally be multiple measurement outcome projectors $$E_i$$. For example, in a 2-D Hilbert space with 3 measurements $$\sigma_x, \sigma_y, \sigma_z$$, each measurement has 2 outcomes, each of which has a projector Ei, for 6 projectors, whereas the real dimension of the space of density matrices is (2⋅22)/2=4, leaving $$A$$ to be 6 x 4. To solve the system, multiply on the left by $$A^T$$:
 * $$A^T A \vec\rho = A^T \vec{p}$$.

Now solving for $$\vec\rho$$ yields the pseudoinverse:
 * $$\vec\rho = (A^T A)^{-1} A^T \vec{p}$$.

This works in general only if the measurement list Ei is tomographically complete. Otherwise, the matrix $$A^T A$$ will not be invertible.

Continuous variables and quantum homodyne tomography
In infinite dimensional Hilbert spaces, e.g. in measurements of continuous variables such as position, the methodology is somewhat more complex. One notable example is in the tomography of light, known as optical homodyne tomography. Using balanced homodyne measurements, one can derive the Wigner function and a density matrix for the state of the light.

One approach involves measurements along different rotated directions in phase space. For each direction $$\theta$$, one can find a probability distribution $$w(q,\theta)$$ for the probability density of measurements in the $$\theta$$ direction of phase space yielding the value $$q$$. Using an inverse Radon transformation (the filtered back projection) on $$w(q,\theta)$$ leads to the Wigner function, $$\mathrm{W}(x,p)$$, which can be converted by an inverse Fourier transform into the density matrix for the state in any basis. A similar technique is often used in medical tomography.

Example: single-qubit state tomography
The density matrix of a single qubit can be expressed in terms of its Bloch vector $$\vec{r}$$ and the Pauli vector $$\vec{\sigma}$$:

 * $$ \rho = \frac{1}{2}\left(I + \vec{r} \cdot \vec{\sigma}\right)

= \frac{1}{2}\begin{pmatrix} 1 + r_z & r_x - \mathrm i r_y \\ r_x + \mathrm i r_y &  1 -  r_z \end{pmatrix}$$.

The single-qubit state tomography can be performed by means of single-qubit Pauli measurements:

 * 1) First, create a list of three quantum circuits, with the first one measuring the qubit in the computational basis (Z-basis), the second one performing a Hadamard gate before measurement (which makes the measurement in X-basis), and the third one performing the appropriate phase shift gate (that is $$\sqrt{Z}^{\dagger}=|0\rangle\langle 0|+\exp(-\mathrm i \pi/2)|1\rangle\langle 1|$$) followed by a Hadamard gate before measurement (which makes the measurement in Y-basis);
 * 2) Then, run these circuits (typically thousands of times), and the counts in the measurement results of the first circuit produces $$\bar{z}=(n_{z,+}-n_{z,-})/(n_{z,+}+n_{z,-})$$, the second circuit $$\bar{x}$$, and the third circuit $$\bar{y}$$;
 * 3) Finally, if $$\bar{x}^2+\bar{y}^2+\bar{z}^2\leq 1$$, then a measured Bloch vector is produced as $$\vec{r}_{m}=(\bar{x},\bar{y},\bar{z})$$, and the measured density matrix is $$  \rho_m = \frac{1}{2}\left(I + \vec{r}_m \cdot \vec{\sigma}\right)$$; If $$\bar{x}^2+\bar{y}^2+\bar{z}^2>1$$, it'll be necessary to renormalize the measured Bloch vector as $$\vec{r}_{m}=(\bar{x},\bar{y},\bar{z})/\sqrt{\bar{x}^2+\bar{y}^2+\bar{z}^2}$$ before using it to calculate the measured density matrix.

This algorithm is the foundation for qubit tomography and is used in some quantum programming routines, like that of Qiskit.

Example: homodyne tomography.
Electromagnetic field amplitudes (quadratures) can be measured with high efficiency using photodetectors together with temporal mode selectivity. Balanced homodyne tomography is a reliable technique of reconstructing quantum states in the optical domain. This technique combines the advantages of the high efficiencies of photodiodes in measuring the intensity or photon number of light, together with measuring the quantum features of light by a clever set-up called the homodyne tomography detector.

Quantum homodyne tomography is understood by the following example. A laser is directed onto a 50-50% beamsplitter, splitting the laser beam into two beams. One is used as a local oscillator (LO) and the other is used to generate photons with a particular quantum state. The generation of quantum states can be realized, e.g. by directing the laser beam through a frequency doubling crystal and then onto a parametric down-conversion crystal. This crystal generates two photons in a certain quantum state. One of the photons is used as a trigger signal used to trigger (start) the readout event of the homodyne tomography detector. The other photon is directed into the homodyne tomography detector, in order to reconstruct its quantum state. Since the trigger and signal photons are entangled (this is explained by the spontaneous parametric down-conversion article), it is important to realize that the optical mode of the signal state is created nonlocal only when the trigger photon impinges the photodetector (of the trigger event readout module) and is actually measured. More simply said, it is only when the trigger photon is measured, that the signal photon can be measured by the homodyne detector.

Now consider the homodyne tomography detector as depicted in figure 4 (figure missing). The signal photon (this is the quantum state we want to reconstruct) interferes with the local oscillator, when they are directed onto a 50-50% beamsplitter. Since the two beams originate from the same so called master laser, they have the same fixed phase relation. The local oscillator must be intense, compared to the signal so it provides a precise phase reference. The local oscillator is so intense, that we can treat it classically (a = α) and neglect the quantum fluctuations. The signal field is spatially and temporally controlled by the local oscillator, which has a controlled shape. Where the local oscillator is zero, the signal is rejected. Therefore, we have temporal-spatial mode selectivity of the signal. The beamsplitter redirects the two beams to two photodetectors. The photodetectors generate an electric current proportional to the photon number. The two detector currents are subtracted and the resulting current is proportional to the electric field operator in the signal mode, depended on relative optical phase of signal and local oscillator.

Since the electric field amplitude of the local oscillator is much higher than that of the signal the intensity or fluctuations in the signal field can be seen. The homodyne tomography system functions as an amplifier. The system can be seen as an interferometer with such a high intensity reference beam (the local oscillator) that unbalancing the interference by a single photon in the signal is measurable. This amplification is well above the photodetectors noise floor.

The measurement is reproduced a large number of times. Then the phase difference between the signal and local oscillator is changed in order to ‘scan’ a different angle in the phase space. This can be seen from figure 4. The measurement is repeated again a large number of times and a marginal distribution is retrieved from the current difference. The marginal distribution can be transformed into the density matrix and/or the Wigner function. Since the density matrix and the Wigner function give information about the quantum state of the photon, we have reconstructed the quantum state of the photon.

The advantage of this balanced detection method is that this arrangement is insensitive to fluctuations in the intensity of the laser.

The quantum computations for retrieving the quadrature component from the current difference are performed as follows.

The photon number operator for the beams striking the photodetectors after the beamsplitter is given by:
 * $$\hat n_{i}=\hat a_{i}^\dagger \hat a_{i}$$,

where i is 1 and 2, for respectively beam one and two. The mode operators of the field emerging the beamsplitters are given by:
 * $$\hat a_{1}= 2^{-1/2}(\hat a - \alpha_{LO})$$
 * $$\hat a_{2}= 2^{-1/2}(\hat a + \alpha_{LO})$$

The $$\hat a$$ denotes the annihilation operator of the signal and alpha the complex amplitude of the local oscillator. The number of photon difference is eventually proportional to the quadrature and given by:
 * $$\hat n_{21}=\hat n_{2} - \hat n_{1} = \alpha^*_{LO} \hat a + \alpha_{LO} \hat a^\dagger$$,

Rewriting this with the relation:
 * $$ \hat q=2^{-1/2}(\hat a^\dagger+\hat a)$$

Results in the following relation:
 * $$ \hat n_{21}=2^{1/2}|\hat\alpha_{LO}|\hat q_{\theta}$$,

where we see clear relation between the photon number difference and the quadrature component $$ \hat q_{\theta}$$. By keeping track of the sum current, one can recover information about the local oscillator's intensity, since this is usually an unknown quantity, but an important quantity for calculating the quadrature component $$ \hat q_{\theta}$$.

Problems with linear inversion
One of the primary problems with using linear inversion to solve for the density matrix is that in general the computed solution will not be a valid density matrix. For example, it could give negative probabilities or probabilities greater than 1 to certain measurement outcomes. This is particularly an issue when fewer measurements are made.

Another issue is that in infinite dimensional Hilbert spaces, an infinite number of measurement outcomes would be required. Making assumptions about the structure and using a finite measurement basis leads to artifacts in the phase space density.

Maximum likelihood estimation
Maximum likelihood estimation (also known as MLE or MaxLik) is a popular technique for dealing with the problems of linear inversion. By restricting the domain of density matrices to the proper space, and searching for the density matrix which maximizes the likelihood of giving the experimental results, it guarantees the state to be theoretically valid while giving a close fit to the data. The likelihood of a state is the probability that would be assigned to the observed results had the system been in that state.

Suppose the measurements $$\{|y_j\rang \lang y_j|\}$$ have been observed with frequencies $$f_j$$. Then the likelihood associated with a state $$\hat\rho$$ is
 * $$L(\hat\rho) = \prod_j \lang y_j|\hat\rho|y_j\rang^{f_j}$$

where $$\lang y_j|\hat\rho|y_j\rang$$ is the probability of outcome $$y_j$$ for the state $$\hat\rho$$.

Finding the maximum of this function is non-trivial and generally involves iterative methods. The methods are an active topic of research.

Problems with maximum likelihood estimation
Maximum likelihood estimation suffers from some less obvious problems than linear inversion. One problem is that it makes predictions about probabilities that cannot be justified by the data. This is seen most easily by looking at the problem of zero eigenvalues. The computed solution using MLE often contains eigenvalues which are 0, i.e. it is rank deficient. In these cases, the solution then lies on the boundary of the n-dimensional Bloch sphere. This can be seen as related to linear inversion giving states which lie outside the valid space (the Bloch sphere). MLE in these cases picks a nearby point that is valid, and the nearest points are generally on the boundary.

This is not physically a problem, the real state might have zero eigenvalues. However, since no value may be less than 0, an estimate of an eigenvalue being 0 implies that the estimator is certain the value is 0, otherwise they would have estimated some $$\epsilon$$ greater than 0 with a small degree of uncertainty as the best estimate. This is where the problem arises, in that it is not logical to conclude with absolute certainty after a finite number of measurements that any eigenvalue (that is, the probability of a particular outcome) is 0. For example, if a coin is flipped 5 times and each time heads was observed, it does not mean there is 0 probability of getting tails, despite that being the most likely description of the coin.

Bayesian methods
Bayesian mean estimation (BME) is a relatively new approach which addresses the problems of maximum likelihood estimation. It focuses on finding optimal solutions which are also honest in that they include error bars in the estimate. The general idea is to start with a likelihood function and a function describing the experimenter's prior knowledge (which might be a constant function), then integrate over all density matrices using the product of the likelihood function and prior knowledge function as a weight.

Given a reasonable prior knowledge function, BME will yield a state strictly within the n-dimensional Bloch sphere. In the case of a coin flipped N times to get N heads described above, with a constant prior knowledge function, BME would assign $$\scriptstyle\frac{1}{N+2}$$ as the probability for tails.

BME provides a high degree of accuracy in that it minimizes the operational divergences of the estimate from the actual state.

Methods for incomplete data
The number of measurements needed for a full quantum state tomography for a multi-particle system scales exponentially with the number of particles, which makes such a procedure impossible even for modest system sizes. Hence, several methods have been developed to realize quantum tomography with fewer measurements.

The concept of matrix completion and compressed sensing have been applied to reconstruct density matrices from an incomplete set of measurements (that is, a set of measurements which is not a quorum). In general, this is impossible, but under assumptions (for example, if the density matrix is a pure state, or a combination of just a few pure states) then the density matrix has fewer degrees of freedom, and it may be possible to reconstruct the state from the incomplete measurements.

Permutationally Invariant Quantum Tomography is a procedure that has been developed mostly for states that are close to being permutationally symmetric, which is typical in nowadays experiments. For two-state particles, the number of measurements needed scales only quadratically with the number of particles. Besides the modest measurement effort, the processing of the measured data can also be done efficiently: It is possible to carry out the fitting of a physical density matrix on the measured data even for large systems. Permutationally Invariant Quantum Tomography has been combined with compressed sensing in a six-qubit photonic experiment.

Quantum measurement tomography
One can imagine a situation in which an apparatus performs some measurement on quantum systems, and determining what particular measurement is desired. The strategy is to send in systems of various known states, and use these states to estimate the outcomes of the unknown measurement. Also known as "quantum estimation", tomography techniques are increasingly important including those for quantum measurement tomography and the very similar quantum state tomography. Since a measurement can always be characterized by a set of POVM's, the goal is to reconstruct the characterizing POVM's $$\Pi_l$$. The simplest approach is linear inversion. As in quantum state observation, use
 * $$\displaystyle\mathrm{Tr}[\Pi_l \rho_m] = \mathrm{P}(l | \rho_m)$$.

Exploiting linearity as above, this can be inverted to solve for the $$\Pi_l$$.

Not surprisingly, this suffers from the same pitfalls as in quantum state tomography: namely, non-physical results, in particular negative probabilities. Here the $$\Pi_l$$ will not be valid POVM's, as they will not be positive. Bayesian methods as well as Maximum likelihood estimation of the density matrix can be used to restrict the operators to valid physical results.

Quantum process tomography
Quantum process tomography (QPT) deals with identifying an unknown quantum dynamical process. The first approach, introduced in 1996 and sometimes known as standard quantum process tomography (SQPT) involves preparing an ensemble of quantum states and sending them through the process, then using quantum state tomography to identify the resultant states. Other techniques include ancilla-assisted process tomography (AAPT) and entanglement-assisted process tomography (EAPT) which require an extra copy of the system.

Each of the techniques listed above are known as indirect methods for characterization of quantum dynamics, since they require the use of quantum state tomography to reconstruct the process. In contrast, there are direct methods such as direct characterization of quantum dynamics (DCQD) which provide a full characterization of quantum systems without any state tomography.

The number of experimental configurations (state preparations and measurements) required for full quantum process tomography grows exponentially with the number of constituent particles of a system. Consequently, in general, QPT is an impossible task for large-scale quantum systems. However, under weak decoherence assumption, a quantum dynamical map can find a sparse representation. The method of compressed quantum process tomography (CQPT) uses the compressed sensing technique and applies the sparsity assumption to reconstruct a quantum dynamical map from an incomplete set of measurements or test state preparations.

Quantum dynamical maps
A quantum process, also known as a quantum dynamical map, $$\mathcal{E}(\rho)$$, can be described by a completely positive map
 * $$\mathcal{E}(\rho) = \sum_i A_i \rho A_i^\dagger$$,

where $$\rho \in \mathcal{B(H)}$$, the bounded operators on Hilbert space; with operation elements $$\displaystyle A_i$$ satisfying $$\textstyle\sum_i A_i^\dagger A_i \leq I$$ so that $$\mathrm{Tr}[\mathcal{E}(\rho)] \leq 1$$.

Let $$\displaystyle\{E_i\}$$ be an orthogonal basis for $$\mathcal{B(H)}$$. Write the $$\displaystyle A_i$$ operators in this basis
 * $$\displaystyle A_i = \sum_{m} a_{im}E_m$$.

This leads to
 * $$\mathcal{E}(\rho) = \sum_{m,n} \chi_{mn} E_{m} \rho E_n^\dagger$$,

where $$\chi_{mn} = \sum_{i} a_{im} a_{in}^*$$.

The goal is then to solve for $$\displaystyle\chi$$, which is a positive superoperator and completely characterizes $$\mathcal{E}$$ with respect to the $$\displaystyle\{E_i\}$$ basis.

Standard quantum process tomography
SQPT approaches this using $$d^2$$ linearly independent inputs $$\rho_j$$, where $$d$$ is the dimension of the Hilbert space $$\mathcal{H}$$. For each of these input states $$\rho_j$$, sending it through the process gives an output state $$\mathcal{E}(\rho)$$ which can be written as a linear combination of the $$\rho_k$$, i.e. $$\textstyle \mathcal{E}(\rho_j) = \sum_k c_{jk} \rho_k$$. By sending each $$\rho_j$$ through many times, quantum state tomography can be used to determine the coefficients $$c_{jk}$$ experimentally.

Write
 * $$E_m \rho_j E_n^\dagger = \sum_{k} B_{m,n,j,k} \rho_k$$,

where $$B$$ is a matrix of coefficients. Then
 * $$\sum_k c_{jk} \rho_k = \mathcal{E}(\rho_j) = \sum_{m,n} \chi_{m,n} E_m \rho_j E_n^\dagger = \sum_{m,n}\sum_{k} \chi_{m,n} B_{m,n,j,k} \rho_k$$.

Since $$\rho_k$$ form a linearly independent basis,
 * $$\displaystyle c_{jk} = \sum_{m,n}\chi_{m,n} B_{m,n,j,k}$$.

Inverting $$B$$ gives $$\chi$$:
 * $$\chi_{m,n} = \sum_{j,k} B^{-1}_{m,n,j,k} c_{jk}$$.

title: Quantum tomography


text:
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Nabas, Aklan

Nabas, officially the Municipality of Nabas (Aklanon: Banwa it Nabas; Hiligaynon: Banwa sang Nabas; Bayan ng Nabas), is a 4th class municipality in the province of Aklan, Philippines. Nabas serves as the arrival gateway of Boracay Airport. According to the 2020 census, it has a population of 40,632 people, making it the fifth most populous town in Aklan Province..

The resort island of Boracay is located 2 km from the north-westernmost tip of the town.

History
Accounts about the earliest community of Nabas are uncertain but the initial documentation for the town's existence was recorded in 1845. Facing the Sibuyan Sea, the town started as a small coastal village referred to as Barrio Alimbo which extends to the hills and mountains to the west. This small community occupies the floodplains of Alimbo River where the village derived its name. Fishing and farming is the primary source of livelihood, even today except for the hunting which was common on that time because of the abundances of wild pig, monkey and deer in the area.

Before, the town was part of the municipality of Ibajay under the jurisdiction of Capiz Province. Ibajay's municipal boundary was so vast but with poor road system.

The developing populaces whose tongue and customs diverge from those of the eastern community build awareness amongst people of the west. The invasion of migrants from the nearby province of Antique continued that further emphasized the difference in dialect and culture to some extent. In 1853, their notion of a separate municipality for better living and independence serves as the foundation for taking a part of Alimbo together with its adjoining barrios of Nagustan, Panaytayon (Toledo), Gibon, Namao (Rizal), Kabangrosan (Union), and Pakilawa (Unidos) ceased to be a barrio to form a new municipality inevitably. The municipality was formed in 1854 and named Navas, after Governor Nava of the province of Capiz who came to inspect the area before its creation.

In 1861, the residents of Carabao Island (locally known as Hambil Island) chose to be annexed to the municipality of Navas, Capiz following the abolition of the Pueblo de Cabalian in Tablas Island. The annexation continued until 1897 when residents of Carabao Island voted to join the municipality of Looc, Romblon.

The Cartilla System, an early teaching methods that dominantly use the letter "b" than "v" caused the variable spelling of "Navas" and "Nabas". In 1906, the Municipal Council in a resolution approved by unanimous vote adopted the name Nabas as the official name.

Recently, Nabas is currently applying for cityhood making it the third in the province after neighboring Malay and the provincial capital Kalibo.

Geography
Nabas is a strip of land located east of the town of Malay at the north-west tip of Panay Island called Northwest Panay Peninsula. It bounded on the north by Sibuyan Sea; on the south by Pandan, Antique; east by Ibajay; and west by Malay. It is 43 km from Kalibo, the provincial capital.

According to the Philippine Statistics Authority, the municipality has a land area of 96.82 km2 constituting NaN% of the 1,821.42 km2 total area of Aklan.

Landscape
The Municipality of Nabas is considered as rolling terrain and rugged terrain land topographic formation. It has an elongated land area situated along the Northwestern Panay Peninsula, with 21-kilometer coastline facing Sibuyan Sea, and with such a large span of municipal waters, approximately 300 square kilometers.

This town features natural wonders both on the mountains with its natural cold springs, caves and tiny water falls, and the sea which boast of crystal clear waters, coral reefs, and from grey or white sand to assorted coloured pebbly shores.

Nabas has one of the last remaining low elevation intact rainforest that is home to various endemic flora and fauna.

Barangays
Nabas is politically subdivided into 20 barangays. Each barangay consists of puroks and some have sitios.

There are 11 barangays which considered coastal and the rest of which are landlocked barangays. Twelve of these 20 barangays are located along the highway.

Demographics
The population of Nabas has grown dramatically for the past decade. It holds the record of fastest growing population in the whole province of Aklan covering 2011–2015, and third fastest growing population covering 2016-2020.

The Municipality of Nabas was among the fastest growing town having a population growth rate almost three times the rate of the provincial and regional levels. The rapid increase in the population growth could be attributed to in-migration due to its developing tourism industry.

Language
The residents of Nabas speaks Nabasnon, a variant of Karay-a and quite similar to Onhan Language of the islands of Hambil and Southern Tablas in Romblon Province. The eastern half of the municipality has the accent influenced and similar to Karay-a, spoken by the neighboring Antiqueños particularly the people from the towns Libertad, Pandan, and Sebaste of Antique. Those in the western half speak similar to the dialect currently regarded as Malaynon with softer intonation. Aklanon, Hiligaynon, and Tagalog are also widely used.

Economy
Nabas, a 4th class municipality, is noted for its hat and mat industry made of indigenous bariw leaves which abound on the hillsides and plain lowlands of the town. It is likewise a farming and fishing community with its vast lowlands and long shoreline. While the cost of marine commodity has soared due to the proximity of Nabas to Boracay Island, the fishermen remained impoverished.

One of the most imposing presence in Nabas is PetroWind Energy Inc. 36-megawatt wind farm in Brgy Pawa. An array of gigantic wind turbines lined-up along a mountain ridge aimed to spur tourism and add livelihood in the area is the biggest single venture in the province of Aklan.

The town serves as a satellite area for the expansion of tourism from the traditional town of Malay to expand and stretch developments to Nabas.

Culture and Festivals
Nabas is predominantly Roman Catholic. Various religious festivity is being celebrated throughout the year in different villages and in the town as a whole.

The Nabas Bariw Festival is celebrated to commemorate the feast day of Saint Isidore the Farmer, which is chosen as the town's patron saint for the town being originally agricultural. It is celebrated annually from May 12 to 15. This celebration showcases the town's hat, mat and other bariw products as well as the town's unique tourism sites and natural attractions. During this affair, various skills in mat, hat and bag making and designing are demonstrated. Among the events is a contest to produce the biggest hat and mat contest. The festival is highlighted by continuous street dancing by folks from the town's 20 barangays dressed in colorful bariw costumes accompanied by indigenous bamboo instruments.

The Nabas Municipal and Religious Fiesta is celebrated annually to commemorate the feast of Nuestra Señora de Salvacion every September 24. The feast honors the Patron Saint of Our Lady Of Salvation after the town is spared from the Japanese fatal ruthlessness during the World War II.

The Ati-Atihan Festival is also celebrated in Nagustan every February.

The San Juan Fiesta is celebrated along the coastal communities every June 24. Beach side tent parties are being held by families joining the event. Boat racing, swimming, and fluvial parades are among the highlights of the fair.

The Pailaw sa Nabas is a music and light festival held every last quarter of November or 1st quarter of December to mark the start of yuletide season in the town. The opening of lights, musical performances, live bands, and firework display are the highlights of the event.

title: Nabas, Aklan


text:
Managed retreat

Managed retreat involves the purposeful, coordinated movement of people and buildings away from risks. This may involve the movement of a person, infrastructure (e.g., building or road), or community. It can occur in response to a variety of hazards such as flood, wildfire, or drought. Politicians, insurers, and residents are increasingly paying attention to managed retreat from low-lying coastal areas because of the threat of sea level rise due to climate change. Trends in climate change predict substantial sea level rises worldwide, causing damage to human infrastructure through coastal erosion and putting communities at risk of severe coastal flooding. The type of managed retreat proposed depends on the location and type of natural hazard,  and on local policies and practices for managed retreat. In the United Kingdom, managed realignment through removal of flood defences is often a response to sea-level rise exacerbated by local subsidence. In the United States, managed retreat often occurs through voluntary acquisition and demolition or relocation of at-risk properties by government. In the Global South, relocation may occur through government programs. Some low-lying countries, facing inundation due to sea-level rise, are planning for the relocation of their populations, such as Kiribati planning for "Migration with Dignity".

Managed realignment
In the United Kingdom, the main reason for managed realignment is to improve coastal stability, essentially replacing artificial 'hard' coastal defences with natural 'soft' coastal landforms. According to University of Southampton researchers Matthew M. Linham and Robert J. Nicholls, "one of the biggest drawbacks of managed realignment is that the option requires land to be yielded to the sea." One of its benefits is that it can help protect land further inland by creating natural spaces that act as buffers to absorb water or dampen the force of waves.

Managed realignment has also been used to mitigate for loss of intertidal habitat. Although land reclamation has been an important factor for salt marsh loss in the UK in the past, the majority of current salt marsh loss in the UK is believed to be due to erosion. This erosion may involve coastal squeeze, where protective sea walls prevent the landward migration of salt marsh in response to sea level rise when sediment supply is limited. Salt marshes are protected under the EU Habitats Directive as well as providing habitat for a number of species protected by the Birds Directive (see Natura 2000). Following this guidance, the UK's biodiversity action plan aims to prevent net losses to the area of salt marsh present in 1992. It is, therefore, a legal requirement that all losses in marsh area must be compensated by replacement habitat with equivalent biological characteristics. This equates to the need to restore approximately 1.4 km2 of salt marsh habitat per year in the UK. One of the major reasons cited for the slow pace of current salt marsh restoration in the UK is the uncertainty associated with the practice (Foresight).

There are no agreed protocols on the monitoring of managed realignment sites and, consequently, very few of the sites are being monitored consistently and effectively. Due to the low levels of monitoring there is little evidence on which to base future managed realignment projects. This has led to the results of managed realignment schemes being extremely unpredictable.

Relocation programs
Managed retreat in the form of relocation has been used in inland and coastal areas in response to severe flooding and hurricanes. In the United States, this often takes the form of "buyout" programs, in which government acquires and relocates or demolishes at-risk properties. In some cases, individual homes are purchased after disasters. In other cases, such as Odanah and Soldiers Grove, Wisconsin, or Valmeyer, Illinois, or Isle de Jean Charles, Louisiana the entire community has relocated.

Managed retreat can be very controversial. A lawsuit in Del Mar California brought on by residents was initiated to stop a managed retreat program based on worries that home values, insurance costs and restricted home expansion have been effects of the policy. Some areas included in managed retreat are above sea level and are recommended based primarily on estimated engineering costs and by studies financed by the California Coastal Commission itself.

Despite the controversy, as the costs of climate change adaptation increase, more communities are beginning to consider managed retreat. One such community is Marina, California, adjacent to Monterey Bay. Marina's general acceptance of managed retreat became the subject of a Los Angeles Times feature article, published in 2020.

Realignment examples
In the UK, the first managed retreat site was an area of 8000 m2 at Northey Island in Essex flooded in 1991, followed by larger sites at Tollesbury and Orplands (1995), Freiston Shore (2001) and Abbott's Hall Farm, at Great Wigborough in the Blackwater Estuary, it is one of the largest managed retreat schemes in Europe. It covers nearly 280 ha of land on the north side of the estuary (2002) and a number of others. The programme was started by the Essex Wildlife Trust (EWT) who own Abbott's Hall Farm. They made five breaches in the original old sea wall to allow the held-back sea to flood through to create salt marshland. The marshland over time reverted to its original state before cultivation, providing excellent bird habitat and breeding grounds.

Forced retreat under climate change
Since 2010, the New Zealand Coastal Policy Statement, a policy under the Resource Management Act of 1991, has required the government to conduct managed retreats.

As a result of two climate change related landslides in New Zealand in 2005, the Whakatāne District Council began to plan for climate-related migration to the Matatā township over the next decade. The vast majority of residents accepted the need to relocate and did so with council assistance and compensation but one resident has rejected both the process and the need to move and is now the neighbourhood's sole remaining occupant. NIWA coastal hazards expert Rob Bell says the issue of retreat is primarily socio-political rather than technocratic.

title: Managed retreat