The devastating 2004 Indian Ocean tsunami caught millions of coastal residents and the scientific community off-guard. Subsequent research in the Indian Ocean basin has identified prehistoric tsunamis, but the timing and recurrence intervals of such events are uncertain. Here we present an extraordinary 7,400 year stratigraphic sequence of prehistoric tsunami deposits from a coastal cave in Aceh, Indonesia. This record demonstrates that at least 11 prehistoric tsunamis struck the Aceh coast between 7,400 and 2,900 years ago. The average time period between tsunamis is about 450 years with intervals ranging from a long, dormant period of over 2,000 years, to multiple tsunamis within the span of a century. Although there is evidence that the likelihood of another tsunamigenic earthquake in Aceh province is high, these variable recurrence intervals suggest that long dormant periods may follow Sunda megathrust ruptures as large as that of the 2004 Indian Ocean tsunami.
Rare mitochondrial lineages with relict distributions can sometimes be disproportionately informative about deep events in human prehistory. We have studied one such lineage, haplogroup R0a, which uniquely is most frequent in Arabia and the Horn of Africa, but is distributed much more widely, from Europe to India. We conclude that: (1) the lineage ancestral to R0a is more ancient than previously thought, with a relict distribution across the Mediterranean/Southwest Asia; (2) R0a has a much deeper presence in Arabia than previously thought, highlighting the role of at least one Pleistocene glacial refugium, perhaps on the Red Sea plains; (3) the main episode of dispersal into Eastern Africa, at least concerning maternal lineages, was at the end of the Late Glacial, due to major expansions from one or more refugia in Arabia; (4) there was likely a minor Late Glacial/early postglacial dispersal from Arabia through the Levant and into Europe, possibly alongside other lineages from a Levantine refugium; and (5) the presence of R0a in Southwest Arabia in the Holocene at the nexus of a trading network that developed after ~3 ka between Africa and the Indian Ocean led to some gene flow even further afield, into Iran, Pakistan and India.
Endemic animal diseases such as tsetse-transmitted trypanosomosis are a constant drain on the financial resources of African livestock keepers and on the productivity of their livestock. Knowing where the potential benefits of removing animal trypanosomosis are distributed geographically would provide crucial evidence for prioritising and targeting cost-effective interventions as well as a powerful tool for advocacy. To this end, a study was conducted on six tsetse-infested countries in Eastern Africa: Ethiopia, Kenya, Somalia, South Sudan, Sudan and Uganda. First, a map of cattle production systems was generated, with particular attention to the presence of draught and dairy animals. Second, herd models for each production system were developed for two scenarios: with or without trypanosomosis. The herd models were based on publications and reports on cattle productivity (fertility, mortality, yields, sales), from which the income from, and growth of cattle populations were estimated over a twenty-year period. Third, a step-wise spatial expansion model was used to estimate how cattle populations might migrate to new areas when maximum stocking rates are exceeded. Last, differences in income between the two scenarios were mapped, thus providing a measure of the maximum benefits that could be obtained from intervening against tsetse and trypanosomosis. For this information to be readily mappable, benefits were calculated per bovine and converted to US$ per square kilometre. Results indicate that the potential benefits from dealing with trypanosomosis in Eastern Africa are both very high and geographically highly variable. The estimated total maximum benefit to livestock keepers for the whole of the study area amounts to nearly US$ 2.5 billion, discounted at 10% over twenty years - an average of approximately US$ 3300 per square kilometre of tsetse-infested area - but with great regional variation from less than US$ 500 per square kilometre to well over US$ 10,000. The greatest potential benefits accrue to Ethiopia, because of its very high livestock densities and the importance of animal traction, but also to parts of Kenya and Uganda. In general, the highest benefit levels occur on the fringes of the tsetse infestations. The implications of the models' assumptions and generalisations are discussed.
Ochre is a common feature at Middle Stone Age (MSA) sites and has often been interpreted as a proxy for the origin of modern behaviour. However, few ochre processing tools, ochre containers, and ochre-stained artefacts from MSA contexts have been studied in detail within a theoretical framework aimed at inferring the technical steps involved in the acquisition, production and use of these artefacts. Here we analyse 21 ochre processing tools, i.e. upper and lower grindstones, and two ochre-stained artefacts from the MSA layers of Porc-Epic Cave, Dire Dawa, Ethiopia, dated to ca. 40 cal kyr BP. These tools, and a large proportion of the 4213 ochre fragments found at the site, were concentrated in an area devoted to ochre processing. Lower grindstones are made of a variety of raw materials, some of which are not locally available. Traces of use indicate that different techniques were employed to process ochre. Optical microscopy, XRD, μ-Raman spectroscopy, and SEM-EDS analyses of residues preserved on worn areas of artefacts show that different types of ferruginous rocks were processed in order to produce ochre powder of different coarseness and shades. A round stone bearing no traces of having been used to process ochre is half covered with residues as if it had been dipped in a liquid ochered medium to paint the object or to use it as a stamp to apply pigment to a soft material. We argue that the ochre reduction sequences identified at Porc-Epic Cave reflect a high degree of behavioural complexity, and represent ochre use, which was probably devoted to a variety of functions.
The structure, interdependence, and fragility of systems ranging from power-grids and transportation to ecology, climate, biology and even human communities and the Internet have been examined through network science. While response to perturbations has been quantified, recovery strategies for perturbed networks have usually been either discussed conceptually or through anecdotal case studies. Here we develop a network science based quantitative framework for measuring, comparing and interpreting hazard responses as well as recovery strategies. The framework, motivated by the recently proposed temporal resilience paradigm, is demonstrated with the Indian Railways Network. Simulations inspired by the 2004 Indian Ocean Tsunami and the 2012 North Indian blackout as well as a cyber-physical attack scenario illustrate hazard responses and effectiveness of proposed recovery strategies. Multiple metrics are used to generate various recovery strategies, which are simply sequences in which system components should be recovered after a disruption. Quantitative evaluation of these strategies suggests that faster and more efficient recovery is possible through network centrality measures. Optimal recovery strategies may be different per hazard, per community within a network, and for different measures of partial recovery. In addition, topological characterization provides a means for interpreting the comparative performance of proposed recovery strategies. The methods can be directly extended to other Large-Scale Critical Lifeline Infrastructure Networks including transportation, water, energy and communications systems that are threatened by natural or human-induced hazards, including cascading failures. Furthermore, the quantitative framework developed here can generalize across natural, engineered and human systems, offering an actionable and generalizable approach for emergency management in particular as well as for network resilience in general.
BACKGROUND: Female circumcision (FC) has lifelong adverse social and health consequences for women, and its abolition will not only enhance the health of children and women, but also promote gender equality. Like many other Western countries, Norway hosts a large proportion of immigrants from FC-practicing countries, though primarily from Somalia, which is the country with the highest prevalence of FC in the world. A behavioral change by the practicing communities has the best chance to successfully and sustainably eliminate this practice. However, FC prevention programs require a behavioral surveillance that monitors the process of change, with this being the first quantitative study since the major migration of the Somali community to Norway began in 1991 to investigate whether or not Somali immigrants' attitudes toward the practice has improved in favor of its abandonment. METHODS: A cross-sectional study using a respondent-driven sampling (RDS) was conducted in Oslo from April to June of 2011. A sample of 214 persons was interviewed, using structured questionnaires. RESULTS: The results show that 70% of Somalis in Oslo support the discontinuation of all forms of FC compared to 30% who support its continuation, with the latter group more likely to be people who lived in Norway [LESS-THAN OR EQUAL TO] 4 years. Of the 10 girls who came to Norway at the age of [LESS-THAN OR EQUAL TO] 7 years, only one was circumcised, though whether the circumcision occurred before or after the girl’s arrival in Norway remains unclear. The perception that FC is required by religion was the sole factor to be significantly associated with an ongoing support of FC. CONCLUSION: The study reveals that Somalis in Oslo demonstrate a trend to abandon this practice over time. Nevertheless, the 30% of the people who still support its continuation, and who are primarily newly arrived immigrants, require a targeted intervention that is implemented in the early phase of the immigrants' arrival.
Goda Buticha is a cave site near Dire Dawa in southeastern Ethiopia that contains an archaeological sequence sampling the late Pleistocene and Holocene of the region. The sedimentary sequence displays complex cultural, chronological and sedimentological histories that seem incongruent with one another. A first set of radiocarbon ages suggested a long sedimentological gap from the end of Marine Isotopic Stage (MIS) 3 to the mid-Holocene. Macroscopic observations suggest that the main sedimentological change does not coincide with the chronostratigraphic hiatus. The cultural sequence shows technological continuity with a late persistence of artifacts that are usually attributed to the Middle Stone Age into the younger parts of the stratigraphic sequence, yet become increasingly associated with lithic artifacts typically related to the Later Stone Age. While not a unique case, this combination of features is unusual in the Horn of Africa. In order to evaluate the possible implications of these observations, sedimentological analyses combined with optically stimulated luminescence (OSL) were conducted. The OSL data now extend the radiocarbon chronology up to 63 ± 7 ka; they also confirm the existence of the chronological gap between 24.8 ± 2.6 ka and 7.5 ± 0.3 ka. The sedimentological analyses suggest that the origin and mode of deposition were largely similar throughout the whole sequence, although the anthropic and faunal activities increased in the younger levels. Regional climatic records are used to support the sedimentological observations and interpretations. We discuss the implications of the sedimentological and dating analyses for understanding cultural processes in the region.
The Arabic miswak (Somali, adayge) is a tooth-cleaning stick from the Salvadora persica plant. In this article, we trace the social life of a “thing,” examining meanings inscribed in the stick brush, drawing on interviews with 82 Somali refugees in Massachusetts and an analysis of local and transnational science and marketing. The miswak toothbrush symbolizes relationships to nature, homeland culture, global Islam, globalizing dental medicine, and the divine as it intersects with the lives of producers, marketers, distributors, and users, creating hybrid cultural forms in new contexts. [ethnodentistry, Islam, Somali diaspora, commodifiction, miswak] This article is protected by copyright. All rights reserved.
The camel is a multipurpose animal with a huge productive potential. Camel milk is a key food in arid and semi-arid areas of the African and Asian countries. The quality of milk is influenced by different bacteria present in milk. This study was conducted to evaluate total bacterial content in raw camel milk along the market chain in Fafen zone, Ethiopian Somali Regional State.