Aden is a port city and the temporary capital of Yemen, located by the eastern approach to the Red Sea, some 170 km east of Bab-el-Mandeb. Its population is 800,000 people. Aden's natural harbour lies in the crater of a dormant volcano, which now forms a peninsula joined to the mainland by a low isthmus; this harbour, Front Bay, was first used by the ancient Kingdom of Awsan between the 5th and 7th centuries BC. The modern harbour is on the other side of the peninsula. Aden gives its name to the Gulf of Aden. Aden consists of a number of distinct sub-centres: Crater, the original port city. Khormaksar, located on the isthmus that connects Aden proper with the mainland, includes the city's diplomatic missions, the main offices of Aden University, Aden International Airport, Yemen's second biggest airport. On the mainland are the sub-centres of Sheikh Othman, a former oasis area. Aden encloses the eastern side of a natural harbour that comprises the modern port; this city has no natural resources available in it.

However, Aden does have the Aden Tanks. These reservoirs accumulate rain water for the sole purpose of drinking for the city's citizens; the city is prosperous with Indian vessels arriving for trade. The volcanic peninsula of Little Aden forms a near-mirror image, enclosing the harbour and port on the western side. Little Aden became the site of the oil tanker port. Both were established and operated by British Petroleum until they were turned over to Yemeni government ownership and control in 1978. Aden was the capital of the People's Democratic Republic of Yemen until that country's unification with the Yemen Arab Republic in 1990, again served as Yemen's temporary capital during the aftermath of the Houthi takeover in Yemen, as declared by President Abd Rabbuh Mansur Hadi after he fled the Houthi occupation of Sana'a. From March to July 2015, the Battle of Aden raged between loyalists to President Hadi. Water and medical supplies ran short in the city. On 14 July, the Saudi Army launched an offensive to retake Aden for Hadi's government.

Within three days the Houthis had been removed from the city. Since February 2018, Aden has been seized by the Southern Transitional Council, supported by UAE, the Southern Transitional Council was formed from previous Aden Mayor Aidroos Alzubaidi after he was dismissed from his post by Abdrabbuh Mansur Hadi together with sacked former Cabinet minister Salfi-religious leader Hani Bin Buraik. A local legend in Yemen states; some believe that Cain and Abel are buried somewhere in the city. The port's convenient position on the sea route between India and Europe has made Aden desirable to rulers who sought to possess it at various times throughout history. Known as Eudaemon in the 1st century BC, it was a transshipping point for the Red Sea trade, but fell on hard times when new shipping practices by-passed it and made the daring direct crossing to India in the 1st century AD, according to the Periplus of the Erythraean Sea; the same work describes Aden as "a village by the shore," which would well describe the town of Crater while it was still little-developed.

There is no mention of fortification at this stage, Aden was more an island than a peninsula as the isthmus was not so developed as it is today. Although the pre-Islamic Himyar civilization was capable of building large structures, there seems to have been little fortification at this stage. Fortifications at Mareb and other places in Yemen and the Hadhramaut make it clear that both the Himyar and the Sabean cultures were well capable of it. Thus, watch towers, since destroyed, are possible. However, the Arab historians Ibn al Mojawir and Abu Makhramah attribute the first fortification of Aden to Beni Zuree'a. Abu Makhramah has included a detailed biography of Muhammad Azim Sultan Qamarbandi Naqsh in his work, Tarikh ul-Yemen; the aim seems to have been twofold: to keep hostile forces out and to maintain revenue by controlling the movement of goods, thereby preventing smuggling. In its original form, some of this work was feeble. After 1175 AD, rebuilding in a more solid form began, since Aden became a popular city attracting sailors and merchants from Egypt, Gujarat, East Africa and China.

According to Muqaddasi, Persians formed the majority of Aden's population in the 10th century. In 1421, China's Ming dynasty Yongle Emperor ordered principal envoy grand eunuch Li Xing and grand eunuch Zhou Man of Zheng He's fleet to convey an imperial edict with hats and robes to bestow on the king of Aden; the envoys set sail from Sumatra to the port of Aden. This event was recorded in the book Yingyai Shenglan by Ma Huan. In 1513, the Portuguese, led by Afonso de Albuquerque, launched an unsuccessful four-day naval siege of Aden. Before British administration, Aden was ruled by the Portuguese between 1513–1538 and 1547–1548, it was ruled by the Ottoman Empire between 1538–1547 and 1548–1645. In 1609 The Ascension was the first English ship to visit Aden, before sailing on to Mocha during the Fourth voyage

Convenience yield

A convenience yield is an implied return on holding inventories. It is an adjustment to the cost of carry in the non-arbitrage pricing formula for forward prices in markets with trading constraints. Let F t, T be the forward price of an asset with initial price S t and maturity T. Suppose that r is the continuously compounded interest rate for one year; the non-arbitrage pricing formula should be F t, T = S t ⋅ e r However, this relationship does not hold in most commodity markets because of the inability of investors and speculators to short the underlying asset, S t. Instead, there is a correction to the forward pricing formula given by the convenience yield c. Hence F t, T = S t ⋅ e This makes it possible for backwardation to be observable. A trader has observed that the price of six-month gold futures price is $1,300 per troy ounce, whereas the spot price is $1,371 per troy ounce; the borrowing rate for a six-month loan is 3.5% per annum, storage cost for gold is negligible. Since we know we have the relation: F = S What is the convenience yield implied by the futures price?

From the formula above, we isolate the convenience yield, we obtain: c = r + 1 T c = 0.035 + 1 0.5 = 0.13857 = 13.9 % For information, if we had a continuously compounded 6-month borrowing rate and if we were looking for the continuously compounded convenience yield, we would have the formula: F = S ⋅ e T And the convenience yield would therefore be: c = r − 1 T ln ⁡ c = 0.035 − 1 0.5 × ln ⁡ = 0.14135 = 14.1 % Users of a consumption asset may obtain a benefit from physically holding the asset prior to T, not obtained from holding the futures contract. These benefits include the ability to profit from temporary shortages, the ability to keep a production process running. One of the main reasons that it appears is due to availability of stocks and inventories of the commodity in question. Everyone who owns inventory has the choice between consumption investment for the future. A rational investor will choose the outcome, best for himself; when inventories are high, this suggests an expected low scarcity of the commodity today versus some time in the future.

Otherwise, the investor would not perceive that there is any benefit of holding onto inventory and therefore sell his stocks. Hence, expected future prices should be higher than they are. Futures or forward prices F t, T of the asset should be higher than the current spot price, S t. From the above formula, this only tells us that r − c > 0. The interesting line of reasoning comes; when inventories are low, we expect. Unlike the previous case, the investor can not buy inventory to make up for demand today. In a sense, the investor is unable. Therefore, we expect future prices to be lower than today and hence that F t, T < S t. This implies that r − c < 0. The convenience yield is inversely related to inventory levels

Milton Keynes

Milton Keynes ( KEENZ is a large town in Buckinghamshire, about 50 miles north-west of London. It is the principal settlement of the Borough of a unitary authority. At the 2011 Census, its population was 230,000; the River Great Ouse forms its northern boundary. 25% of the urban area is parkland or woodland and includes two SSIs. In the 1960s, the UK Government decided that a further generation of new towns in the South East of England was needed to relieve housing congestion in London; the New Town of Milton Keynes was to be the biggest yet, with a target population of 250,000, in a "designated area" of about 22,000 acres. At designation, its area incorporated the existing towns of Bletchley and Stony Stratford, along with another fifteen villages and farmland in between; these settlements had an extensive historical record since the Norman conquest. The government established a Development Corporation to deliver this New City; the Corporation decided on a softer, more human-scaled landscape than in the earlier new towns but with an emphatically modernist architecture.

Recognising how traditional towns and cities had become choked in traffic, they established a'relaxed' grid of distributor roads about 1 kilometre between edges, leaving the spaces between to develop more organically. An extensive network of shared paths for leisure cyclists and pedestrians criss-crosses through and between them. Again rejecting the residential tower blocks, so fashionable but unloved, they set a height limit of three stories outside the planned centre. Facilities include a 1,400-seat theatre, a municipal art gallery, two multiplex cinemas, an ecumenical central church, a 400-seat concert hall, a teaching hospital, a 30,500-seat football stadium, an indoor ski-slope and a 65,000-capacity open-air concert venue. There are five railway stations; the Open University is based here and there is a campus of the University of Bedfordshire. Most sports are represented at amateur level; the Peace Pagoda overlooking Willen Lake was the first such to be built in Europe. Milton Keynes has one of the more successful economies in the UK, ranked against a number of criteria.

As one of the UK's top five fastest growing centres, it has benefited from above-average economic growth. It has the fifth highest number of business startups per capita, it is home to several major international companies. Despite this economic success and personal wealth for some, there are pockets of nationally significant poverty; the employment profile is composed of 9 % manufacturing. In the 1960s, the UK government decided that a further generation of new towns in the South East of England was needed to relieve housing congestion in London. Since the 1950s, overspill housing for several London boroughs had been constructed in Bletchley. Further studies in the 1960s identified north Buckinghamshire as a possible site for a large new town, a new city, encompassing the existing towns of Bletchley, Stony Stratford and Wolverton; the New Town was to be the biggest yet, with a target population of 250,000, in a "designated area" of 21,883 acres The name "Milton Keynes" was taken from that of an existing village on the site.

On 23 January 1967, when the formal'new town designation order' was made, the area to be developed was farmland and undeveloped villages. The site was deliberately located equidistant from London, Leicester and Cambridge, with the intention that it would be self-sustaining and become a major regional centre in its own right. Planning control was taken from elected local authorities and delegated to the Milton Keynes Development Corporation. Before construction began, every area was subject to detailed archaeological investigation: doing so has exposed a rich history of human settlement since Neolithic times and has provided a unique insight into the history of a large sample of the landscape of North Buckinghamshire; the Corporation's modernist designs were featured in the magazines Architectural Design and the Architects' Journal. MKDC was determined to learn from the mistakes made in the earlier New Towns, revisit the Garden City ideals, they set in place the characteristic grid roads that run between districts, as well as a programme of intensive planting, balancing lakes and parkland.

Central Milton Keynes was not intended to be a traditional town centre but a central business and shopping district to supplement local centres embedded in most of the grid squares. This non-hierarchical devolved city plan was a departure from the English New Towns tradition and envisaged a wide range of industry and diversity of housing styles and tenures; the largest and the last of the British New Towns, Milton Keynes has'stood the test of time far better than most, has proved flexible and adaptable'. The radical grid plan was inspired by the work of Melvin M. Webber, described by the founding architect of Milton Keynes, Derek Walker, as the "fath