SUMMARY / RELATED TOPICS

Car bomb

A car bomb, lorry bomb, or truck bomb known as a vehicle-borne improvised explosive device, is an improvised explosive device designed to be placed and detonated in an automobile or other vehicles. Car bombs can be divided into two main categories: those used to kill the occupants of the vehicle and those used as a means to kill, injure or damage people and buildings outside the vehicle; the latter type may be either parked or the vehicle might be used to deliver the bomb. It is used as a weapon of terrorism or guerrilla warfare to kill people near the blast site or to damage buildings or other property. Car bombs act as their own delivery mechanisms and can carry a large amount of explosives without attracting suspicion. Car bombs are activated in a variety of ways, including opening the vehicle's doors, starting the engine, depressing the accelerator or brake pedals or lighting a fuse or setting a timing device; the gasoline in the vehicle's fuel tank may make the explosion of the bomb more powerful by dispersing and igniting the fuel.

Car bombs are effective weapons as they are an easy way to transport a large amount of explosives to the intended target. A car bomb produces copious shrapnel, or flying debris, secondary damage to bystanders and buildings. In recent years, car bombs have become used by suicide bombers. Defending against a car bomb involves keeping vehicles at a distance from vulnerable targets by using roadblocks and checkpoints, Jersey barriers, concrete blocks or bollards, metal barriers, or by hardening buildings to withstand an explosion. Since the height of the Provisional Irish Republican Army campaign in 1991, the entrance to Downing Street has been closed, preventing the general public from getting near Number 10. Where major public roads pass near buildings, road closures may be the only option; these tactics have encouraged potential bombers to target "soft" or unprotected targets, such as markets. In the Syrian Civil War, Iraq, the car bomb concept was modified so that it could be driven and detonated by a driver, but armoured to withstand incoming fire.

The vehicle would be driven to its target area, in a similar fashion to a kamikaze plane of WW2. These were known by VBIEDs; this saw civilian cars with armour plating added, that would protect the car for as long as possible, so that it could reach its intended target. Cars were sometimes driven into incoming enemy columns. Most the SVIEDs were used by ISIL against Government forces, but used by Syrian rebels against government troops; the vehicles have become more sophisticated, with armour plating on the vehicle, protected vision slits, armour plating over the wheels so they would withstand being shot at, in some cases, additional metal grating over the front of the vehicle designed to activate rocket propelled grenades before hitting the actual surface of the vehicle. In some cases trucks were used, as well as cars, they were sometimes used to start an assault. The vehicles had a large space that would contain heavy explosives. In some cases, animal drawn carts with improvised explosive devices have been used either mules or horses.

Tactically, a single vehicle may be used, or an initial "breakthrough" vehicle followed by another vehicle. While many car bombs are disguised as ordinary vehicles, some that are used against military forces have improvised vehicle armour attached to prevent the driver from being shot when attacking a fortified outpost. Car bombs are preceded by the 16th century hellburners, explosive-laden ships which were used to deadly effect by the besieged Dutch forces in Antwerp against the besieging Spanish. Though using a less refined technology, the basic principle of the hellburner is similar to that of the car bomb; the first reported suicide car bombing was the Bath School bombings of 1927, where 45 people, including the bomber, were killed and half of a school was blown up. Mass-casualty car bombing, suicide car bombing, is a predominantly Middle Eastern phenomenon; the tactic was first introduced to the region by the Zionist paramilitary organization Lehi, who used it extensively against Palestinian and British military targets.

The tactic was used in the Lebanese Civil War by the Shia militia group Hezbollah. A notable suicide car bombing was the 1983 Beirut barracks bombing, when two simultaneous attacks killed 241 U. S. Marines and 58 French military personnel; the perpetrator of these attacks has never been positively confirmed. In the Lebanese Civil War, an estimated 3,641 car bombs were detonated. While not an adaptation of a people-carrying vehicle, the WW2 German Goliath remote control tank, shares many parallels with a vehicle-based IED, it approached a target at some speed, exploded, destroying itself and the target. It was armoured so. However, it was not driven by a person, instead operated by remote control from a safe distance, it was an armoured suicide drone. Car bombs and detonators function in a diverse manner of ways and there are n

Ectomycorrhiza

An ectomycorrhiza is a form of symbiotic relationship that occurs between a fungal symbiont, or mycobiont, the roots of various plant species. The mycobiont is from the phyla Basidiomycota and Ascomycota, more from the Zygomycota. Ectomycorrhizas form on the roots of around 2% of plant species woody plants, including species from the birch, myrtle, willow and rose families. Research on ectomycorrhizas is important in areas such as ecosystem management and restoration and agriculture. Unlike other mycorrhizal relationships, such as arbuscular mycorrhiza and ericoid mycorrhiza, ectomycorrhizal fungi do not penetrate their host's cell walls. Instead they form an intercellular interface known as the Hartig net, consisting of branched hyphae forming a latticework between epidermal and cortical root cells. Ectomycorrhizas are further differentiated from other mycorrhizas by the formation of a dense hyphal sheath, known as the mantle, surrounding the root surface; this sheathing mantle can be up to 40 µm thick, with hyphae extending up to several centimeters into the surrounding soil.

The hyphal network helps the plant to take up nutrients including water and minerals helping the host plant to survive adverse conditions. In exchange, the fungal symbiont is provided with access to carbohydrates. Well known EcM fungal fruiting bodies include the economically important and edible truffle and the deadly death caps and destroying angels. Mycorrhizal symbioses are ubiquitous in terrestrial ecosystems, it is possible that these associations helped to facilitate land colonization by plants. There is paleobiological and molecular evidence that arbuscular mycorrhizas originated at least 460 million years ago. EcM plants and fungi exhibit a wide taxonomic distribution across all continents, suggesting that the EcM symbiosis has ancient evolutionary roots. Pinaceae is the oldest extant plant family in which symbiosis with EcM fungi occurs, fossils from this family date back to 156 million years ago, it has been proposed that habitat type and the distinct functions of different mycorrhizas help determine which type of symbiosis is predominant in a given area.

In this theory, EcM symbioses evolved in ecosystems such as boreal forests that are productive but in which nutrient cycling is still limiting. Ectomycorrhizas are intermediate in their ability to take up nutrients, being more efficient than arbuscular mycorrhizas and less so than ericoid mycorrhizas, making them useful in an intermediate nutrient situation. Fungi are composed of soft tissues, making fossilization difficult and the discovery of fungal fossils rare. However, some exquisitely preserved specimens have been discovered in the middle Eocene Princeton Chert of British Columbia; these ectomycorrhizal fossils show clear evidence of a Hartig net and hyphae, demonstrating well-established EcM associations at least 50 million years ago. The fossil record shows that the more common arbuscular mycorrhizas formed long before other types of fungal-plant symbioses. Ectomycorrhizas may have evolved with the diversification of plants and the evolution of conifers and angiosperms. Arbuscular mycorrhizas may thus have been a driving force in the plant colonization of land, while ectomycorrhizas may have arisen either in response to further speciation as the earth's climate became more seasonal and arid, or simply in response to nutritionally deficient habitats.

Molecular and phylogenetic analyses of fungal lineages suggest that EcM fungi have evolved and persisted numerous times from non-EcM ancestors such as humus and wood saprotrophic fungi. The estimates range from 7-16 to ~66 independent evolutions of EcM associations; some studies suggest that reversals back to the ancestral free-living condition have occurred, but this is controversial. As suggested by the name, the biomass of the mycosymbiont is exterior to the plant root; the fungal structure is composed of three parts: 1) the intraradical hyphae making up the Hartig net. The Hartig net is formed by an ingrowth of hyphae into the root of the plant host; the hyphae penetrate and grow in a transverse direction to the axis of the root, thus form a network between the outer cells of the root axis. In this region fungal and root cells touch, this is where nutrient and carbon exchange occurs; the depth of penetration differs between species. In Eucalyptus and Alnus the Hartig net is confined to the epidermis, whereas in most gymnosperms the hyphae penetrate more into the cortical cells or the endodermis.

In many epidermal types elongation of cells along the epidermis occurs, increasing surface contact between fungus and root cells. Most cortical type Hartig nets do not show this elongation, suggesting different strategies for increasing surface contact among species. A hyphal sheath known as the mantle, which has more biomass than the Hartig net interface, envelops the root; the structure of the mantle is variable, ranging from a loose network of hyphae to a structured and stratified arrangement of tissue. These layers resemble plant parenchyma tissue and are referred to as pseudoparenchymatous; because the root is enveloped by the mantle it is affected developmentally. EcM fungal partners characteristically suppress root hair development of their plant symbiont, they can increase root branching by inducing cytokinins in the p

China–Kazakhstan border

The China–Kazakhstan border, or the Sino-Kazakhstan border is the international border between the People's Republic of China and the Republic of Kazakhstan. The border line between the two countries has been inherited from the border existing between the Soviet Union and the PRC, earlier, between the Russian Empire and the Qing Empire. According to the international boundary commissions that have carried out the border demarcation, the border is 1,782.75 km long. The origins of the border date from the mid-19th century, when the Russian Empire expanded into Central Asia, was able to establish its control over the Lake Zaysan region; the establishment of the border between the Russian Empire and the Qing Empire, not too different from today's Sino-Kazakh/Kyrgyz/Tajik border was provided for in the Convention of Peking of 1860. The Qing Empire's military presence in the Irtysh basin crumbled during the Dungan revolt. After the fall of the rebellion and the reconquest of Xinjiang by Zuo Zongtang, the border between the Russian and the Qing empires in the Ili River basin was further readjusted, in Russia's favour, by the Treaty of Saint Petersburg and a series of protocols.

In 1915 an agreement was signed more delimiting the border the Ili Valley and Dzungarian Alatau region. The southern-most section of the frontier remained undemarcated, owing to the ongoing rivalry between Britain and Russia for dominance in Central Asia known as the Great Game. China was not a party to these agreement and hence the southern-most section of the China-Russia boundary remained undefined. After the Xinhai Revolution and the Chinese Civil War in China and the October Revolution and the Russian Civil War in Russia, the Sino-Russian border became the PRC-USSR border. However, the Chinese and Soviet authorities were not always in agreement where the border line ran on the ground, which led, in particular to a border conflict east of Lake Zhalanashkol in August 1969. After Kazakhstan became an independent country, it negotiated a border treaty with China, signed in Almaty on April 26, 1994, ratified by the President of Kazakhstan on June 15, 1995. According to the treaty, a narrow strip of hilly terrain east of Zhalanashkol which the USSR and China had contested in 1969 has become recognized as part of China.

To delineate certain small sections of the border more additional agreements were signed on 24 September 1997 and 4 July 1998. Over the next several years, the border was demarcated on the ground by joint commissions. According to the commissions' protocols and maps, the two countries' border line is 1782.75 km long, including 1215.86 km of land border and 566.89 km of border line run along rivers or lakes. The commissions' work was documented by several joint protocols, finalized with the Protocol signed in Beijing on May 10, 2002. In 2011 a cross-border free trade area opened on the border at Khorgos in an effort to boost Chinese-Kazakh trade; the two countries' border protection authorities carry out regular meetings, on occasions joint border patrols. Maikapchagai -Jemina Bakhty - Tacheng Dostyk/Druzhba – Alashankou Khorgos – Khorgas Kolzhat – Dulart Tacheng Huocheng Khorgos Alekseyeva Taunchang Akshoky Bakhty Dostyk Almaly Khorgos Kolzhat Sarybastau Sumbe Narynkol Historical maps of the China-Kazakh SSR border from north to south, mid & late 20th century: International Map of the World: Operational Navigation Chart: Tactical Pilotage Chart: China–Kazakhstan relations 中哈边界.