The Carbon, Phosphorus, and Nitrogen Cycles and the Human Impact on Essay

The Carbon, Phosphorus, and Nitrogen Cycles and the Human Impact on These Cycles - Essay Example Carbon cycle is typically carried out whenever a hydrocarbon fuel or petroleum uses oxygen for combustion to run an engine of a vehicle or a facotry equipment. Like respiration, during combustion the carbon and hydrogen content of fuel are burned to yield water and carbon dioxide as products given off to the atmosphere. These products as well as the energy released by the exothermic reaction are then absorbed by the plants so the latter manages to produce its own food as photosynthesis takes place with the help other nutrients besides the sustenance provided by carbon dioxide. These plants consequently emit oxygen back into the atmosphere and possess carbohydrates, formed out of using carbon dioxide and water, with its stored energy to be used by the living organism once again. When weathering occurs, phosphate cycle begins when the inorganic materials containing phosphorus and phosphate ions in certain ocean salts or rock sediments are transported to land. Plants eventually take them in and are transferred to herbivores upon consumption and these herbivores may be eaten further by carnivorous animals so that the latter are also imparted a share of phosphorus or phosphates. At the point of death, they are brought back to soil by the decomposers that feed on decaying bodies with phosphorus and these materials may return to the ocean or be reconstituted into the rocks by means of run-off water.

Outline the history of excavation and interpretation at Great Essay

Outline the history of excavation and interpretation at Great Zimbabwe. What does this history tell us about colonialist ideolog - Essay Example At the Ruanga and Chipadze ruins, cattle were important. Five of the excavated ruins have produced dates that suggest they were all built and occupied between the beginning of the fourteenth and the end of the fifteenth centuries. Some have been dated as late as the sixteenth century (Fagan, 1984). In terms of development in the colonial era, the church offered education and what would today be known as "development" for Africans on the model of charitable church acts. These historical ties laid the foundations for modern development efforts: Christian missions worked arm-in-arm with the state to provide education as well as agricultural training in attempts to "educate" Africans, and at the same time, to create a passive, productive rural labor force for colonial capitalism. There has been widespread scholarship on colonial missions in Africa (Hall, & Bombardella, 2005). The colonial era was marked by the efforts of the state to control the work of missionaries, and by tensions of i nvolvement between missionaries and colonial administrations. These dynamics are important not only in terms of historical context, but as points of reference, as they are noticeable in the modern work of Christian NGOs. In southern Rhodesia, missionaries worked in collaboration with colonial administrators, bargaining with Cecil Rhodes, the head of the British South Africa Company, for land to build schools, chapels, in addition to hospitals (Shepherd, 2002). The system of indirect rule positioned local rulers in opposition to missionaries. Although missions served the colonial regime by intervening the spread of Western culture as well as morally legitimizing colonial rule, they also undermined the regimes dependence on customary authority and "heathen" practices. In northern Rhodesia, this turned volatile, when native catechists worked in opposition to the traditions of the customary rulers supported by British indirect rule. To the extent that the command of African chiefs depen ded on the culture as well as customary infrastructure of social life, missionaries produced a novel type of "disorder" from the perspective of the colonial administration in the form of millennial movements. Garlake, (1982) documents how in South Africa, as missionaries advocated nonconformist native relations as well as abolitionist movements, they were placed in opposing and collaborative relationships with the colonial and settler states (Hall, 1995). After independence and through the newly formed socialist state, ZANU-PF renewed and transformed dialogues of community development from development-as-charity in the colonial era to development as the right of Zimbabwean citizens. In so doing, the state faced a challenge of legality as it required gaining authority over a rural population that had been politicized in opposition to the Rhodesian state during the war (Piriyaki, 1999). As the mission-educated African elite came to power in recently independent socialist Zimbabwe, the church once again (as in the colonial era) was politically associated with the state. In the early years of independence, doctrines of Christian socialism imposed a welfare state that promised to relieve economic inequalities created by colonialism and to bring fairness to all Africans (Fontein, 2006). This period saw a large propagation of NGO activity in Zimbabwe as the