Kunming is the capital and the largest city of Yunnan province—China's fourth least developed province based on disposable income per capita. Known as Yunnan-Fu until the 1920s, today it is a prefecture-level city and the political, economic and cultural centre of the province as well as the seat of the provincial government; the headquarters of many of Yunnan's large businesses are in Kunming. It was important during World War II as a Chinese military center, American air base, transport terminus for the Burma Road. Located in the middle of the Yunnan–Guizhou Plateau, Kunming is located at an altitude of 1,900 metres above sea level and at a latitude just north of the Tropic of Cancer; as of 2014, Kunming has a population of 6,626,000 with an urban population of 4,575,000, is located at the northern edge of Dian Lake, surrounded by temples and lake-and-limestone hill landscapes. Kunming consists of an old walled city, a modern commercial district, residential zones and university areas; the city has an astronomical observatory, its institutions of higher learning include Yunnan University, Yunnan Normal University, Kunming University of Science and Technology, Kunming Medical University.

On the northeast mountainous outskirt is a bronze temple dating from the Ming dynasty, the largest of its kind in China. Its economic importance derives from its geographical position, it is positioned near the border with Southeastern Asian countries, serving as a transportation hub in Southwest China, linking by rail to Vietnam and by road to Burma and Thailand. This positioning makes it an important trade center in this region of the nation, it houses some manufacturing, chiefly the processing of copper, as well as various chemicals, textiles and cement. Though having a nearly 2,400-year history, its modern prosperity dates only from 1910, when the railway from Hanoi was built; the city has continued to develop under China's modernization efforts. Kunming's streets have widened while housing projects develop at a fast pace. Kunming has been designated a special tourism center and as such sports a proliferation of high-rises and luxury hotels. Kunming long profited from its position on the caravan roads through to South-East Asia and Tibet.

Early townships in the southern edge of Lake Dianchi can be dated back to 279 BC, although they have been long lost to history. Early settlements in the area around Lake Dian date back to Neolithic times; the Dian Kingdom, whose original language was related to Tibeto-Burman languages was established near the area. Dian was subjugated by the Chinese Han dynasty under the reign of Emperor Wu of Han in 109 BC; the Han dynasty incorporated the territory of the Dian Kingdom into their Yizhou Commandery, but left the King of Dian as the local ruler. The Han dynasty, seeking control over the Southern Silk Road running to Burma and India, brought small parts of Yunnan into China's orbit, though subsequent dynasties could do little to tame what was a remote and wild borderland. During the Sui dynasty, two military expeditions were launched against the area, it was renamed Kunzhou in Chinese sources. Founded in 765, Kunming was known to the Chinese as Tuodong city in the Kingdom of Nanzhao during the 8th and 9th centuries.

Tuodong became part of the successor Kingdom of Dali. The possession of Tuodong changed hands when the city came under the control of the Yuan dynasty invasion of the southwest in 1252–1253. During the reign of provincial governor Ajall Shams al-Din Omar, a "Chinese Style" city named Zhongjing Chen was founded where modern Kunming is today. Shams al-Din ordered the construction of Buddhist temple, a Confucian temple, two mosques in the city; the Confucian temple, doubling as a school, was the first of its kind in Yunnan, attracting students from minority groups across the province. Coupled with his promotion of Confucian ceremonies and customs, Shams al-Din has been credited with the sinicization of the region; the city grew as the rest of China. It is considered by scholars to have been the city of Yachi Fu where people had used cowries as cash and ate their meat raw, as described by the 13th-century Venetian traveler Marco Polo. In the 14th century, Kunming was retaken from Mongolian control when the Ming dynasty defeated the Yuan Dynasty building a wall surrounding present-day Kunming.

300 years Ming General Wu Sangui defected to Manchu invaders and held the city until his death in 1678, long after the rest of China had fallen under Manchu rule. During the beginning of Qing rule, the entirety of Yunnan and Guizhou were ruled from Kunming and Wu. During the Revolt of the Three Feudatories, the seat of Wu's newly declared Zhou dynasty was moved to Hengzhou, Hunan. In 1678 when Wu died, his grandson Wu Shifan resisted the Qing for two more months before committing suicide, thereby reverting control of the city back into Qing hands. During the Ming and Qing dynasties, it was the seat of the superior prefecture of Yunnan; the area was first dubbed Kunming in the period towards the decline of the Yuan dynasty and still in 1832, the beginnings of a real city were acknowledged within the city walls and significant structures within their confines. Founding of the city can, therefore be said to have been a predominantly 19th century affair, it was in this century that the city grew to become the major market and transport centre for the region.

Many of the city's inhabitants were displaced as a result of the 1833 Kunming earthquake. The rebel leader Du Wenxiu, the Muslim Han Sultan of Dali, attacked and

Pulmonary alveolus

A pulmonary alveolus is a hollow cup-shaped cavity found in the lung parenchyma where gas exchange takes place. Lung alveoli are found in the acini at the beginning of the respiratory zone, they are located sparsely on the respiratory bronchioles, line the walls of the alveolar ducts, are more numerous in the blind-ended alveolar sacs. The acini are the basic units of respiration, with gas exchange taking place in all the alveoli present; the alveolar membrane is the gas exchange surface, surrounded by a network of capillaries. Across the membrane oxygen is diffused into the capillaries and carbon dioxide released from the capillaries into the alveoli to be breathed out. Alveoli are particular to mammalian lungs. Different structures are involved in gas exchange in other vertebrates; the alveoli are located in the alveolar sacs of the lungs in the pulmonary lobules of the respiratory zone, representing the smallest functional units in the respiratory tract. They are present in the respiratory bronchioles as scattered outpockets, extending from their lumens.

The respiratory bronchioles lead into alveolar ducts which are lined with alveoli. Each respiratory bronchiole gives rise to between eleven alveolar ducts; each duct opens into six alveolar sacs into which clusters of alveoli open. New alveoli continue to form until the age of eight years. A typical pair of human lungs contain about 300 million alveoli; each alveolus is wrapped in a fine mesh of capillaries covering about 70% of its area. The diameter of an alveolus is between 500 µm; the alveoli consist of an epithelial layer of simple squamous epithelium, an extracellular matrix surrounded by capillaries. The epithelial lining is part of the alveolar membrane known as the respiratory membrane, that allows the exchange of gases; the membrane has several layers – a layer of lining fluid that contains surfactant, the epithelial layer and its basement membrane. The whole membrane however is only between 0.2 µm at 0.6 µm at its thickest. In the alveolar walls there are interconnecting air passages between the alveoli known as the pores of Kohn.

The alveoli contain elastic fibers. The elastic fibres allow the alveoli to stretch, they spring back during exhalation in order to expel the carbon dioxide-rich air. There are three major types of alveolar cell. Two types are pneumocytes known as type I and type II cells found in the alveolar wall, a large phagocytic cell known as an alveolar macrophage that moves about in the lumens of the alveoli, in the connective tissue between them. Type I cells are squamous and flat and form the structure of the alveoli. Type II cells release pulmonary surfactant to lower surface tension. Type II cells can differentiate to replace damaged type I cells. Type I cells are flat epithelial lining cells, that form the structure of the alveoli, they are squamous and their long cytoplasmic extensions line more than 95% of the alveolar surface. Type I cells are involved in the process of gas exchange between blood; these cells are thin sometimes only 25 nm – the electron microscope was needed to prove that all alveoli are lined with epithelium.

This thin lining enables a fast diffusion of gas exchange between the air in the alveoli and the blood in the surrounding capillaries. The nucleus of a type I cell occupies a large area of free cytoplasm and its organelles are clustered around it reducing the thickness of the cell; this keeps the thickness of the blood-air barrier reduced to a minimum. The cytoplasm in the thin portion contains pinocytotic vesicles which may play a role in the removal of small particulate contaminants from the outer surface. In addition to desmosomes, all type I alveolar cells have occluding junctions that prevent the leakage of tissue fluid into the alveolar air space; the low solubility of oxygen, necessitates the large internal surface area and thin walls of the alveoli. Weaving between the capillaries and helping to support them is an extracellular matrix, a meshlike fabric of elastic and collagenous fibres; the collagen fibres, being more rigid, give the wall firmness, while the elastic fibres permit expansion and contraction of the walls during breathing.

Type I pneumocytes are susceptible to toxic insults. In the event of damage, type II cells can proliferate and differentiate into type I cells to compensate. Type II cells are the most numerous cells in the alveoli, yet do not cover as much surface area as the squamous type I cells. Type II cells in the alveolar wall contain secretory granular organelles known as lamellar bodies that fuse with the cell membranes and secrete pulmonary surfactant; this surfactant is a film of fatty substances, a group of phospholipids that reduce alveolar surface tension. The phospholipids are stored in the lamellar bodies. Without this coating, the alveoli would collapse; the surfactant is continuously released by exocytosis. Reinflation of the alveoli following exhalation is made easier by the surfactant, which reduces surface tension in the thin fluid coating of the alveoli; the fluid coating is produced by the body in order to facilitate the transfer of gases between blood and alveolar air, the type II cells are found at the blood-air barrier.

Type II cells start to develop at about 2

Bernhard Danckelmann

Bernhard Engelbert Joseph Danckelmann was a German forester and forest scientist. He studied forestry at the Eberswalde Forest Academy in 1850–52, studied law at the University of Berlin. From 1862 he worked as an Oberförster in Hambach, two years became a forest inspector in Potsdam. In 1866 he was appointed director of the Forest Academy in Eberswalde. From 1869 he was editor of the Zeitschrift für Forst und Jagdwesen. Die Forstakademie Eberwalde von 1830 bis 1880, in: Festschrift für die Fünfzigjährige Jubelfeier der Forstakademie Eberswalde, 1880, pp. -62 – The forest academy in Eberswalde from 1830 to 1880, in: Festschrift for fifty years of jubilant celebration of the forestry academy in Eberswalde. Die Ablösung und Regelung der Waldgrundgerechtigkeiten, 1880. Die deutschen Nutzholzzölle. Forstbotanischer Garten Eberswalde Albrecht Milnik: Bernhard Danckelmann. Leben und Leistungen eines Forstmannes. Nimrod, Suderburg 1999, 352 S. ISBN 3-927848-28-X Albrecht Milnik: Bernhard Danckelmann, in ders.

Et al.: Im Dienst am Wald – Lebenswege und Leistungen brandenburgischer Forstleute. Brandenburgische Lebensbilder. Verlag Kessel, Remagen-Oberwinter 2006, ISBN 3-935638-79-5, S. 231–233. Works by or about Bernhard Danckelmann at Internet Archive Literature by and about Bernhard Danckelmann in the German National Library catalogue Eintrag in Meyers Konversationslexikon 1905ff. Materialien zur Entstehungsgeschichte des BGB Biographie Staatsbibliothek Berlin