92 research outputs found
Coastal Management: A guide to using archaeological, palaeoenvironmental, historical and artistic resources
This ‘Guide’ has been produced as part of the project ‘Archaeology, art and coastal heritage: tools to support coastal management and climate change planning across the Channel Regional Sea’ (Arch-Manche). It details how data sources have been identified, ranked and analysed together to provide evidence of coastal change. Experiences of deploying a range of field investigation techniques to gather scientific data supporting understanding of past coastal change are detailed. The importance of this work in relation to coastal management is presented through a range of results from case studies within areas exhibiting different physical and geomorphological characteristics. The results demonstrate the asyet unrealised potential within archaeological, paleoenvironmental, historical and artistic resources to inform on the scale and pace of coastal change
Thermal age, cytosine deamination and the veracity of 8,000 year old wheat DNA from sediments
YesRecently, the finding of 8,000 year old wheat DNA from submerged marine sediments (1) was challenged on the basis of a lack of signal of cytosine deamination relative to three other data sets generated from young samples of herbarium and museum specimens, and a 7,000 year old human skeleton preserved in a cave environment (2). The study used a new approach for low coverage data sets to which tools such as mapDamage cannot be applied to infer chemical damage patterns. Here we show from the analysis of 148 palaeogenomic data sets that the rate of cytosine deamination is a thermally correlated process, and that organellar generally shows higher rates of deamination than nuclear DNA in comparable environments. We categorize four clusters of deamination rates (alpha,beta,gamma,epsilon) that are associated with cold stable environments, cool but thermally fluctuating environments, and progressively warmer environments. These correlations show that the expected level of deamination in the sedaDNA would be extremely low. The low coverage approach to detect DNA damage by Weiss et al. (2) fails to identify damage samples from the cold class of deamination rates. Finally, different enzymes used in library preparation processes exhibit varying capability in reporting cytosine deamination damage in the 5 prime region of fragments. The PCR enzyme used in the sedaDNA study would not have had the capability to report 5 prime cytosine deamination, as they do not read over uracil residues, and signatures of damage would have better been sought at the 3 prime end. The 8,000 year old sedaDNA matches both the thermal age prediction of fragmentation, and the expected level of cytosine deamination for the preservation environment. Given these facts and the use of rigorous controls these data meet the criteria of authentic ancient DNA to an extremely stringent level
Bleu Arabia: Palaeolithic and underwater survey in SW Saudi Arabia and the role of coasts in Pleistocene dispersals
The role of coastal regions and coastlines in the dispersal of human populations from Africa and across the globe has been highlighted by the recent polarisation between coastal and interior models. The debate has been clouded by the use of the single term ‘coastal dispersal’ to embrace what is in fact a wide spectrum of possibilities, ranging from seafaring populations who spend most of their time at sea living off marine resources, to land-based populations in coastal regions with little or no reliance on marine foods. An additional complicating factor is the fact of Pleistocene and early Holocene sea-level change, which exposed an extensive coastal region that is now submerged, and may have afforded very different conditions from the modern coastal environment. We examine these factors in the Arabian context and use the term ‘Blue’ to draw attention to the fertile coastal rim of the Arabian Peninsula, and to the now submerged offshore landscape, which is especially extensive in some regions. We further emphasise that the attractions of the coastal rim are a product of two quite different factors, ecological diversity and abundant water on land, which have created persistently ‘Green’ conditions throughout the vagaries of Pleistocene climate change in some coastal regions, especially along parts of the western Arabian escarpment, and potentially productive marine environments around its coastline, which include some of the most fertile in the world. We examine the interplay of these factors in the Southwest region of Saudi Arabia and the southern Red Sea, and summarise some of the results of recent DISPERSE field investigations, including survey for Palaeolithic sites on the mainland, and underwater survey of the continental shelf in the vicinity of the Farasan Islands. We conclude that coastlines are neither uniformly attractive nor uniformly marginal to human dispersal, that they offer diverse opportunities that were spatially and temporally variable at scales from the local to the continental, and that investigating Blue Arabia in relation to its episodically Green interior is a key factor in the fuller understanding of long-term human population dynamics within Arabia and their global implications
Моделирование двух частотного акустического тракта для прибора диагностики гайморита
В данной ВКР проводилось изучение методов диагностики гайморита, применения ультразвука в медицине, метода конечных элементов, двухчастотного метода для компенсации погрешности измерения ультразвукового локатора. Кроме того, построены многослойные модели в программной пакете COMSOL, проведены предварительные расчеты распространения упругой волны в различных средах, имеющих различную геометрическую форму на разработанной модели, обработаны принятые сигналы для определения начала прихода эхо-сигнала, разработана структурная схема прибора, а также рассчитаны необходимые элементы для его реализации.In this diplom were studied methods for diagnosing sinusitis, ultrasound in medicine purpose, the finite element method, and the two-frequency method to compensate the measurement error of ultrasonic locators. In addition, multilayer models were built in the COMSOL software package, preliminary calculations of the propagation of an elastic wave in various media with different geometric shapes, received signals were processed to determine the recieve moment of the echo signal, a structural diagram of the device was developed, and the necessary elements were calculated
Blue Arabia : Palaeolithic and Underwater Survey in SW Saudi Arabia and the Role of Coasts in Pleistocene Dispersal
The role of coastal regions and coastlines in the dispersal of human populations from Africa and across the globe has been highlighted by the recent polarisation between coastal and interior models. The debate has been clouded by the use of the single term ‘coastal dispersal’ to embrace what is in fact a wide spectrum of possibilities, ranging from seafaring populations who spend most of their time at sea living off marine resources, to land-based populations in coastal regions with little or no reliance on marine foods. An additional complicating factor is the fact of Pleistocene and early Holocene sea-level change, which exposed an extensive coastal region that is now submerged, and may have afforded very different conditions from the modern coastal environment. We examine these factors in the Arabian context and use the term ‘Blue’ to draw attention to the fertile coastal rim of the Arabian Peninsula, and to the now submerged offshore landscape, which is especially extensive in some regions. We further emphasise that the attractions of the coastal rim are a product of two quite different factors, ecological diversity and abundant water on land, which have created persistently ‘Green’ conditions throughout the vagaries of Pleistocene climate change in some coastal regions, especially along parts of the western Arabian escarpment, and potentially productive marine environments around its coastline, which include some of the most fertile in the world. We examine the interplay of these factors in the Southwest region of Saudi Arabia and the southern Red Sea, and summarise some of the results of recent DISPERSE field investigations, including survey for Palaeolithic sites on the mainland, and underwater survey of the continental shelf in the vicinity of the Farasan Islands. We conclude that coastlines are neither uniformly attractive nor uniformly marginal to human dispersal, that they offer diverse opportunities that were spatially and temporally variable at scales from the local to the continental, and that investigating Blue Arabia in relation to its episodically Green interior is a key factor in the fuller understanding of long-term human population dynamics within Arabia and their global implications
Sedimentary DNA from a submerged site reveals wheat in the British Isles 8000 years ago
YesThe Mesolithic-to-Neolithic transition marked the time when a hunter-gatherer economy gave way to agriculture, coinciding with rising sea levels. Bouldnor Cliff, is a submarine archaeological site off the Isle of Wight in the United Kingdom that has a well-preserved Mesolithic paleosol dated to 8000 years before the present. We analyzed a core obtained from sealed sediments, combining evidence from microgeomorphology and microfossils with sedimentary ancient DNA (sedaDNA) analyses to reconstruct floral and faunal changes during the occupation of this site, before it was submerged. In agreement with palynological analyses, the sedaDNA sequences suggest a mixed habitat of oak forest and herbaceous plants. However, they also provide evidence of wheat 2000 years earlier than mainland Britain and 400 years earlier than proximate European sites. These results suggest that sophisticated social networks linked the Neolithic front in southern Europe to the Mesolithic peoples of northern Europe
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