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Most studies on dietary vegetable oil in rainbow trout (Oncorhynchus mykiss) have been conducted on a background of dietary EPA (20 : 5n-3) and DHA (22 : 6n-3) contained in the fishmeal used as a protein source in aquaculture feed. If dietary EPA and DHA repress their endogenous synthesis fromα-linolenic acid (ALA, 18 : 3n-3), then the potential of ALA-containing vegetable oils to maintain tissue EPA and DHA has been underestimated. We examined the effect of individual dietaryn-3 PUFA on the expression of the biosynthetic genes required for metabolism of ALA to DHA in rainbow trout. A total of 720 juvenile rainbow trout were allocated to twenty-four experimental tanks and assigned one of eight diets. The effect of dietary ALA, EPA or DHA, in isolation or in combination, on hepatic expression of fatty acyl desaturase (FADS)2a(Δ6),FADS2b(Δ5), elongation of very long-chain fatty acid (ELOVL)5andELOVL2was examined after 3 weeks of dietary intervention. The effect of these diets on liver and muscle phospholipid PUFA composition was also examined. The expression levels ofFADS2a(Δ6), ELOVL5andELOVL2were highest when diets were high in ALA, with no added EPA or DHA. Under these conditions ALA was readily converted to tissue DHA. Dietary DHA had the largest and most consistent effect in down-regulating the gene expression of all four genes. TheELOVL5expression was the least responsive of the four genes to dietaryn-3 PUFA changes. These findings should be considered when optimising aquaculture feeds containing vegetable oils and/or fish oil or fishmeal to achieve maximum DHA synthesis.

The Australian Murray cod supports a growing national industry. However, with regard to the process of weaning fry, there is a lack of information and optimal procedures need to be developed. The aim of the present investigation was to test the biological and economic efficacy of different weaning strategies for Murray cod. Three weaning strategies were tested on triplicate groups of fish: (1) only Artemia for 5 d, 7 d on Artemia plus starter diet, and 14 d on dry diet only; (2) 12 d on Artemia plus starter diet and 14 d on dry diet only; and (3) directly to dry diet for the entire experimental period. No significant differences were recorded in the growth and feed efficiency, while significantly higher mortality (38.4 ± 0.35%) was recorded in fish weaned directly onto dry diet. Fish subjected to the first 5 d on Artemia only showed a growth reduction during this period, which was compensated by a phase of enhanced growth during the dry-diet phase. No significant differences were noted in the proximate composition of fish under the different treatments. The economic evaluation suggested that the treatment with the simultaneous supply of Artemia and starter diet is preferable.

This article spans the fifty years of the independent Sudan (1956–2006) during which the country was torn by five civil wars made manifest by the historic marginalization of the Sudanese on the periphery by the powerful riverine Sudanese living in the heartland along the Nile, the awlad al-bahr (people of the river) and the deep cultural, ethnic, linguistic, and religious differences between those of the center and the periphery that have produced four of the five civil wars. The longest, most violent, and destructive were the two civil wars between the northern and southern Sudanese, the Anya-Nya civil war, 1963–1972 and the second southern civil war, 1983–2006. Moreover, the second southern civil war experienced from 1991 to 1996 its own internal civil war between the Dinka and Nuer that caused enormous casualties and suffering before the Sudan People's Liberation Army could establish its supremacy. After the military coup detat (June 30, 1989) and the subsequent Islamist revolution, insurgencies erupted both in the East led by the Beja Congress in 1994 and in the West in Darfur by the Sudan Liberation Movement and the Justice and Equality Movement in 2003. The Beja insurgency was settled in 2006 but the disaster in Darfur continues after great loss of life. This article summarizes each of these insurgencies, interprets their ideology, and analyzes the deep tensions which produced them.

The history of the Sudan has been the subject of greater inquiry than almost any other country of Sub-Saharan Africa. The scope and depth of the literature is overwhelming and cannot and should not be repeated here, for there are several excellent bibliographies which the general reader, student, or scholar can consult to investigate specific subjects. This bibliography was compiled by me during the writing of A Modern History of the Sudan (forthcoming) for the Cambridge University Press. Upon completion of the manuscript for the press, my editor and I realized that this bibliography of books concerning the history of the modern Sudan was much too long and detailed for a general history. I subsequently reduced the number of books listed here to only a third of those most pertinent to the text.

This study, based on 3 years of commercial data, presents the results of an economic analysis of a 20-tonne per annum (TPA) commercial recirculating aquaculture system (RAS) facility located in Warrnambool, Victoria, Australia. Based on the assumptions of the analysis, results highlight the non-viability of the facility, with a 10-year projected negative cumulative cash flow of −$648,038, and negative net present value (NPV) of −$707,546. Economies of scale were assessed by the development of economic models for hypothetical 50-TPA and 100-TPA facilities, based on the actual figures obtained from the 20-TPA case study. These analyses highlighted marginal viability for the 50-TPA facility (with a ten-year projected cumulative cash flow of $1,030,300; negative NPV of −$167,651 and internal rate of return (IRR) of 11.75%), and an economically viable 100-TPA facility (with a ten-year projected cumulative cash flow of $3,176,750; NPV of $522,200 and IRR of 21.03%). Sensitivity analysis highlighted that the greatest gains to be realised in improving profitability were those associated with increasing the productive capacity of the facility, increasing the sale price of the product, and decreasing the capital costs of RAS facilities. Contradictions between the results from the present study to similar studies clearly highlight a need for further economic analyses of commercial RAS facilities, using commercial data sets and standard economic analysis procedures.

After the great drought of the 1980s, the waters of the Nile River returned in abundance during the last decade of the 20th century; however, the peoples of the Nile Basin are reproducing at a greater rate than the waters of the Nile. The claims to this scarce resource are based on history and equity, which are fundamentally incompatible. Despite the creation of basin state organizations for discussion, conferences, and the intervention of the World Bank, the ten basin states, particularly Egypt, are determined to construct their own projects for Nile Control to feed their citizens in the new millennium.

This chapter describes the African slave trade to Asia across the Sahara Desert. The only criteria for the Muslim was that the slave be pagan, and since African traditional religions were unacceptable, sub-Saharan Africa became the most important source of slaves for the Muslim merchants who established elaborate commercial networks to transport them out of Africa across the Sahara, the Red Sea and the Indian Ocean. The Red Sea slave trade was ironically older than the trans-Saharan. The Greek mercantile presence in the Indian Ocean did not survive the dominance of Rome in the Mediterranean, but trade on the East African coast was continued as in the past by merchants from Arabia, Persia, India, and China who plied the waters of the Indian Ocean on the monsoon winds of the Sabaean Lane. Slavery was an institution in most African societies, and its abolition came later than in the Americas. Keywords:African slave trade; Americas; Arabia; Asia; Greek; Indian Ocean; Muslim; Persia; Red Sea

This essay seeks to place the events in Turkan during the first decades of the twentieth century into a wider perspective. Despite their modest numbers and the wasteland they inhabited, the challenge to the Turkana did not come from their neighbors, whom they could raid with success or live in harmony with. The threat to their traditional way of life came from Ethiopian and British imperialism, the reasons and forces of which the Turkana were oblivious to. Britain could not tolerate an Ethiopian presence in Turkan and regarded the problem of the Turkana as largely an imperial contest with the “Abyssinians.” In the 1960s and 1970s revisionist historians challenged this interpretation, arguing that the Turkana, in order to defeat their African neighbors, adopted new leaders and military techniques in the 1880s that introduced into Turkana society a new and aggressive militarism. Since their territorial ambitions in Turkan appeared to have been satisfied by using these tactics by the 1890s, Turkana “militarism” was thereafter used to defend their pastures and waterholes from incursions by African neighbors, to recover livestock stolen by them, or to replenish Turkana herds lost to raids, drought, or disease. Turkana historians have thus argued that the representation of Turkana militarism for continued territorial expansion is more a Western creation, for the Turkana were more concerned to defend their acquired territory than participate in unprovoked belligerence against imperial invaders. Sadly, at the time neither of the protagonists could have predicted the subsequent unmitigated disaster for the Turkana in the aftermath of the Turkana Patrol of 1918, in which they had become the unwitting victims of a larger conflict for control of an imperial frontier.

The mean total length (LT), mass and age of ready to migrate female silver shortfin eels Anguilla australis from the Hopkins River estuary and the mouth of the Merri River in south-eastern Australia, were 83·2 ± 1·2 cm, 1051 ± 51 g, and 17·2 ± 1·79 years, respectively. The eye index (IE) of the silver shortfin eels was 50% of all the fatty acids in the lipid.

In glass eels (54 mm TL; 0.018 g) of the Australian shortfin eel Anguilla australis the fatty acid composition was typical of marine species, with a n-3 to n-6 ratio of 5.3, a low level of mono saturated fatty acids (monoenes) and a high level of polyunsaturated fatty acids (PUFA). In elvers (pigmented: 56 mm TL; 0.028 g), the n-3 to n-6 ratio was 2.6. In elvers monoenes, as per cent of all identifiable fatty acids, increased to 30.9% from that of 19.8% in glass eels. The fatty acid composition of juvenile eels, reared from the original stock of glass eels and elvers, in outdoor, fertilized ponds, with (115 mmTL; 2.2 g) and without feeding (110 mmTL; 1.9 g), had a fatty acid composition typical of freshwater species, with a n-3 to n-6 ratio 1.9 and 1.3, and 37.7 and 46.5% of monoenes in unfed and fed groups respectively. A principal component analysis summarized efficiently the progressive changes in fatty acid composition from the glass eel to juvenile eel stage. The observed changes in the fatty acid of the different developmental stages in Australian shortfin eel are discussed in relation to physiological changes associated with the diadromous habit.

The second edition of A History of Sub-Saharan Africa continues to provide an accessible introduction to the continent's history for students and general readers. The authors employ a thematic approach to their subject, focusing on how the environment has shaped the societies and cultures of the African peoples. The text demonstrates how the geography, climate and geology of Africa influenced the rise of states and empires, the emergence of the trans-Atlantic slave trade, the European conquest and the creation of independent African nations. Yet the book maintains a focus on the peoples whose creative energies built unique communities and traditions within the challenging context of the Africa landmass. In the process of reconstructing this continent's rich history, the authors analyze the contentious scholarly debates that have emerged from this field. The book is illustrated with photographs, maps and sidebars that feature the salient points on either side of the debates.

After traversing more than three millennia of the African past, it is time to pause and take stock, to look back in history as well as forward, at the beginning of the twenty-first century. Over the past half-century, scholars have scoured archaeological sites, colonial archives, published works, and oral traditions; utilized social science methodologies – anthropology, linguistics, and demography; and developed an appreciation of African art, music, and literature, to construct a new paradigm for understanding the continent's past. We hope that readers of this text will have recognized the themes in the last several thousand years of the African past that thread their way through the text into the twenty-first century. They are indeed the themes of this book, and they will most certainly reappear – in different forms, to be sure – in the twenty-first century. Environment continues to shape the lives of the African peoples. As seen in the previous chapters, population has long been tied to the interaction between humans and the unique African environment. In relation to its landmass, Africa has, historically, been under populated. Two thousand years ago, Africa south of the Sahara had only an estimated population one-fifth that of China or the Roman Empire. During the next 1,500 years, this ratio continued to decline so that by 1500, Africa contained less than an estimated 15 percent of the world's human beings. At the beginning of the twentieth century, the population of Africa accounted for only about 1 percent of the 2 billion people inhabiting the earth. The reasons for this low rate of growth remain unclear to this day. Was this creeping rate of reproduction caused by a harsh climate, disease, poor soils, conflict, and slavery? One can only reflect and suggest that the reasons lie in the complex interaction between humanity and nature in Africa.

After four hundred years during which Europe had displayed little or no interest in Africa beyond its coastline, suddenly – in the twenty years between 1878 and 1898 – the European states partitioned and conquered virtually the entire continent. To observers in the last quarter of the nineteenth century, this sudden conquest was a frantic, often unseemly, and largely unexpected scramble for territory in a continent about which the Europeans knew little and for which most cared nothing. Their sentiments were encapsulated in the famous remark by the English historian John H. Seeley that his generation had conquered half of the world “in a fit of absence of mind.” Today, however, with the advantage of hindsight historians have perceived several fundamental causes and events that combined to upset four hundred years of equilibrium between Africa and Europe and precipitate the European conquest of virtually the entire continent. The Industrial Revolution created demands for new raw materials from Africa, and made Africa an attractive potential market for European manufactured goods. Moreover, the new technologies produced by the Industrial Revolution provided the instruments that upset the long-standing balance of power between Africa and Europe. Imperialism was propelled as well by popular nationalism, which pressed European statesmen into pursuing expansionist policies in the name of imperial defense. Changing terms of trade required European merchants to seek political stability in Africa, where for centuries they had profited from the instability that had fostered the slave trade. European Christianity was also changing in the nineteenth century, as the new and powerful Evangelical movement inspired aggressive missionary activity, which in the past had been largely confined to the African coast, deeper into the continent.