Investigation into the nexus of human-environmental behavior has seen increasing collaboration of... more Investigation into the nexus of human-environmental behavior has seen increasing collaboration of archaeologists, historians, and paleo-scientists. However, many studies still lack interdisciplinarity and overlook incompatibilities in spatiotemporal scaling of environmental and societal data and their uncertainties. Here, we argue for a strengthened commitment to collaborative work and introduce the "dahliagram" as a tool to analyze and visualize quantitative and qualitative knowledge from diverse disciplinary sources and epistemological backgrounds. On the basis of regional cases of past human mobility in eastern Africa, Inner Eurasia, and the North Atlantic, we develop three dahliagrams that illustrate pull and push factors underlying key phases of population movement across different geographical scales and over contrasting periods of time since the end of the last Ice Age. Agnostic to analytical units, dahliagrams offer an effective tool for interdisciplinary investigation, visualization, and communication of complex human-environmental interactions at a diversity of spatiotemporal scales.
HAL (Le Centre pour la Communication Scientifique Directe), 2018
Introduction. Living in arid environments from prehistoric times to the present day: approaches t... more Introduction. Living in arid environments from prehistoric times to the present day: approaches to the study of refugia and oases
HAL (Le Centre pour la Communication Scientifique Directe), 2013
Tell Hamoukar’s Southern Extension, occupied during the late Chalcolithic 1-2 period and located ... more Tell Hamoukar’s Southern Extension, occupied during the late Chalcolithic 1-2 period and located in northern Mesopotamia, presents a unique early household craft-manufacturing site at a scale never before seen for the period. The large quantities of obsidian on the site, collected through both systematic survey and excavation, are unattested for this period at such distances from available source zones. In addition to the large quantities of obsidian collected, the form in which this worked obsidian was recovered attests to a major obsidian production economy that is almost entirely dependent on this stone resource for tool production. This paper discusses the nature of the Southern Extension occupation and its possible role in obsidian circulation in this period through geochemical source analyses of a sample of the worked obsidian excavated as well as through a preliminary morpho-technological study of its residents’ lithic industry.
Journal of Archaeological Science: Reports, Oct 1, 2016
Background: Hexuronic acids such as D-galacturonic acid and D-glucuronic acid can be utilized via... more Background: Hexuronic acids such as D-galacturonic acid and D-glucuronic acid can be utilized via different pathways within the metabolism of microorganisms. One representative, the oxidative pathway, generates α-ketoglutarate as the direct link entering towards the citric acid cycle. The penultimate enzyme, keto-deoxy glucarate dehydratase/decarboxylase, catalyses the dehydration and decarboxylation of keto-deoxy glucarate to α-ketoglutarate semialdehyde. This enzymatic reaction can be tracked continuously by applying a pH-shift assay. Results: Two new keto-deoxy glucarate dehydratases/decarboxylases (EC 4.2.1.41) from Comamonas testosteroni KF-1 and Polaromonas naphthalenivorans CJ2 were identified and expressed in an active form using Escherichia coli ArcticExpress(DE3). Subsequent characterization concerning K m , k cat and thermal stability was conducted in comparison with the known keto-deoxy glucarate dehydratase/decarboxylase from Acinetobacter baylyi ADP1. The kinetic constants determined for A. baylyi were K m 1.0 mM, k cat 4.5 s −1 , for C. testosteroni K m 1.1 mM, k cat 3.1 s −1 , and for P. naphthalenivorans K m 1.1 mM, k cat 1.7 s −1. The two new enzymes had a slightly lower catalytic activity (increased K m and a decreased k cat) but showed a higher thermal stability than that of A. baylyi. The developed pHshift assay, using potassium phosphate and bromothymol blue as the pH indicator, enables a direct measurement. The use of crude extracts did not interfere with the assay and was tested for wild-type landscapes for all three enzymes. Conclusions: By establishing a pH-shift assay, an easy measurement method for keto-deoxy glucarate dehydratase/ decarboxylase could be developed. It can be used for measurements of the purified enzymes or using crude extracts. Therefore, it is especially suitable as the method of choice within an engineering approach for further optimization of these enzymes.
Climate conditions in Africa have varied substantially during the Late Quaternary with alternatin... more Climate conditions in Africa have varied substantially during the Late Quaternary with alternating humid and arid periods controlled mainly by the African monsoonal regime. However, the duration and termination of the last African Humid Period (14e6 ka BP) and its internal climatic variability are still debated. Using a laminated sequence from the Nile Deep-Sea Fan, we reconstruct for the first time the monsoon-induced frequency of exceptional Nile floods at centennial resolution during the African Humid Period. By combining sedimentological, geochemical and microscopic tools and comparing our record with two proximal piston cores and with regional paleoclimatic records, we show: a) the occurrence of recurrent high-energy floods between 10.1 and 9 ka BP, during the height of the African Humid Period; b) a shift in the hydro-climatic regime as early as 9 ka BP, with a progressive reduction in flood frequency and magnitude until 8.2 ka BP, likely related to a southward migration of the monsoon rainfall belt; c) a drastic reduction of flood activity between 8.2 and 7.8 ka BP; d) an unstable Ethiopian-Nile hydrological system from 7.8 ka BP, followed by a further decrease in river runoff until~4 ka BP. The occurrence of a stepwise hydro-climatic deterioration over the Ethiopian Highlands from~9 ka BP brings into question the climatic linkages and feedbacks between low and high latitudes during the Early to Mid-Holocene and in particular around the 8.2 ka BP North Atlantic cooling event. Our unique record of flood frequency at centennial-resolution therefore allows us to draw new insights on fluvial and geomorphic feedbacks of the Nile hydrologic system to monsoonal regimes during a period of major environmental shifts.
L’étude des échanges d’obsidienne permet d’obtenir une meilleure connaissance des systèmes d’inte... more L’étude des échanges d’obsidienne permet d’obtenir une meilleure connaissance des systèmes d’interaction entre les villages sédentaires au début du Néolithique au Proche-Orient. Le modèle d’échange d’obsidienne, down-the-line, a dominé pour expliquer la diffusion de l’obsidienne entre les villages néolithiques. Cependant, l’information disponible sur la quantité d’obsidienne présente dans les sites, les simulations mathématiques de cette distribution et l’observation des parallèles ethnographiques suggèrent l’existence d’un modèle d’échange plus complexe au cours de cette période. Dans cet article, nous utilisons l’analyse de régression pour étudier les données archéologiques et proposer l’existence d’un réseau complexe, testé par modélisation mathématique, pour expliquer les échanges d’obsidienne. À l’appui des données ethnographiques et archéologiques, on discute des implications d’ordre social et économique de ce réseau complexe d’échanges entre les villages néolithiques.
In this paper, we explore the conditions that led to the origins and development of the Near East... more In this paper, we explore the conditions that led to the origins and development of the Near Eastern Neolithic using mathematical modelling of obsidian exchange. The analysis presented expands on previous research, which established that the down-the-line model could not explain long-distance obsidian distribution across the Near East during this period. Drawing from outcomes of new simulations and their comparison with archaeological data, we provide results that illuminate the presence of complex networks of interaction among the earliest farming societies. We explore a network prototype of obsidian exchange with distant links which replicates the long-distance movement of ideas, goods and people during the Early Neolithic. Our results support the idea that during the first (Pre-Pottery Neolithic A) and second (Pre-Pottery Neolithic B) phases of the Early Neolithic, the complexity of obsidian exchange networks gradually increased. We propose then a refined model (the optimized dis...
Enhanced continental weathering (δ 7 Li, εNd) during the rise of East African complex polities: a... more Enhanced continental weathering (δ 7 Li, εNd) during the rise of East African complex polities: an early large-scale anthropogenic forcing?
Until recently, the western Arabian Peninsula has had an enigmatic role in the large-scale prehis... more Until recently, the western Arabian Peninsula has had an enigmatic role in the large-scale prehistoric exchange networks of the greater ancient Near East. New geological and archaeological data recovered from obsidian-rich zones as well as sites in south-west Arabia and beyond, have begun to elucidate the region’s unprecedented position as a regional and interregional supplier and consumer of obsidian as early as the sixth millennium BC. This paper reviews recent data on obsidian sourcing in Arabia as well as new source matches to archaeological sites in the major source zone supplying obsidian across the region, namely the Dhamār highland plains of Yemen, and discusses the results within the context of previous obsidian research. These data offer new perspectives that will allow us to broaden our understanding of the development of ancient Near Eastern societies over time, to include south-west Arabia. Furthermore, these new data provide us with a preliminary diachronic view of the...
Investigation into the nexus of human-environmental behavior has seen increasing collaboration of... more Investigation into the nexus of human-environmental behavior has seen increasing collaboration of archaeologists, historians, and paleo-scientists. However, many studies still lack interdisciplinarity and overlook incompatibilities in spatiotemporal scaling of environmental and societal data and their uncertainties. Here, we argue for a strengthened commitment to collaborative work and introduce the "dahliagram" as a tool to analyze and visualize quantitative and qualitative knowledge from diverse disciplinary sources and epistemological backgrounds. On the basis of regional cases of past human mobility in eastern Africa, Inner Eurasia, and the North Atlantic, we develop three dahliagrams that illustrate pull and push factors underlying key phases of population movement across different geographical scales and over contrasting periods of time since the end of the last Ice Age. Agnostic to analytical units, dahliagrams offer an effective tool for interdisciplinary investigation, visualization, and communication of complex human-environmental interactions at a diversity of spatiotemporal scales.
HAL (Le Centre pour la Communication Scientifique Directe), 2018
Introduction. Living in arid environments from prehistoric times to the present day: approaches t... more Introduction. Living in arid environments from prehistoric times to the present day: approaches to the study of refugia and oases
HAL (Le Centre pour la Communication Scientifique Directe), 2013
Tell Hamoukar’s Southern Extension, occupied during the late Chalcolithic 1-2 period and located ... more Tell Hamoukar’s Southern Extension, occupied during the late Chalcolithic 1-2 period and located in northern Mesopotamia, presents a unique early household craft-manufacturing site at a scale never before seen for the period. The large quantities of obsidian on the site, collected through both systematic survey and excavation, are unattested for this period at such distances from available source zones. In addition to the large quantities of obsidian collected, the form in which this worked obsidian was recovered attests to a major obsidian production economy that is almost entirely dependent on this stone resource for tool production. This paper discusses the nature of the Southern Extension occupation and its possible role in obsidian circulation in this period through geochemical source analyses of a sample of the worked obsidian excavated as well as through a preliminary morpho-technological study of its residents’ lithic industry.
Journal of Archaeological Science: Reports, Oct 1, 2016
Background: Hexuronic acids such as D-galacturonic acid and D-glucuronic acid can be utilized via... more Background: Hexuronic acids such as D-galacturonic acid and D-glucuronic acid can be utilized via different pathways within the metabolism of microorganisms. One representative, the oxidative pathway, generates α-ketoglutarate as the direct link entering towards the citric acid cycle. The penultimate enzyme, keto-deoxy glucarate dehydratase/decarboxylase, catalyses the dehydration and decarboxylation of keto-deoxy glucarate to α-ketoglutarate semialdehyde. This enzymatic reaction can be tracked continuously by applying a pH-shift assay. Results: Two new keto-deoxy glucarate dehydratases/decarboxylases (EC 4.2.1.41) from Comamonas testosteroni KF-1 and Polaromonas naphthalenivorans CJ2 were identified and expressed in an active form using Escherichia coli ArcticExpress(DE3). Subsequent characterization concerning K m , k cat and thermal stability was conducted in comparison with the known keto-deoxy glucarate dehydratase/decarboxylase from Acinetobacter baylyi ADP1. The kinetic constants determined for A. baylyi were K m 1.0 mM, k cat 4.5 s −1 , for C. testosteroni K m 1.1 mM, k cat 3.1 s −1 , and for P. naphthalenivorans K m 1.1 mM, k cat 1.7 s −1. The two new enzymes had a slightly lower catalytic activity (increased K m and a decreased k cat) but showed a higher thermal stability than that of A. baylyi. The developed pHshift assay, using potassium phosphate and bromothymol blue as the pH indicator, enables a direct measurement. The use of crude extracts did not interfere with the assay and was tested for wild-type landscapes for all three enzymes. Conclusions: By establishing a pH-shift assay, an easy measurement method for keto-deoxy glucarate dehydratase/ decarboxylase could be developed. It can be used for measurements of the purified enzymes or using crude extracts. Therefore, it is especially suitable as the method of choice within an engineering approach for further optimization of these enzymes.
Climate conditions in Africa have varied substantially during the Late Quaternary with alternatin... more Climate conditions in Africa have varied substantially during the Late Quaternary with alternating humid and arid periods controlled mainly by the African monsoonal regime. However, the duration and termination of the last African Humid Period (14e6 ka BP) and its internal climatic variability are still debated. Using a laminated sequence from the Nile Deep-Sea Fan, we reconstruct for the first time the monsoon-induced frequency of exceptional Nile floods at centennial resolution during the African Humid Period. By combining sedimentological, geochemical and microscopic tools and comparing our record with two proximal piston cores and with regional paleoclimatic records, we show: a) the occurrence of recurrent high-energy floods between 10.1 and 9 ka BP, during the height of the African Humid Period; b) a shift in the hydro-climatic regime as early as 9 ka BP, with a progressive reduction in flood frequency and magnitude until 8.2 ka BP, likely related to a southward migration of the monsoon rainfall belt; c) a drastic reduction of flood activity between 8.2 and 7.8 ka BP; d) an unstable Ethiopian-Nile hydrological system from 7.8 ka BP, followed by a further decrease in river runoff until~4 ka BP. The occurrence of a stepwise hydro-climatic deterioration over the Ethiopian Highlands from~9 ka BP brings into question the climatic linkages and feedbacks between low and high latitudes during the Early to Mid-Holocene and in particular around the 8.2 ka BP North Atlantic cooling event. Our unique record of flood frequency at centennial-resolution therefore allows us to draw new insights on fluvial and geomorphic feedbacks of the Nile hydrologic system to monsoonal regimes during a period of major environmental shifts.
L’étude des échanges d’obsidienne permet d’obtenir une meilleure connaissance des systèmes d’inte... more L’étude des échanges d’obsidienne permet d’obtenir une meilleure connaissance des systèmes d’interaction entre les villages sédentaires au début du Néolithique au Proche-Orient. Le modèle d’échange d’obsidienne, down-the-line, a dominé pour expliquer la diffusion de l’obsidienne entre les villages néolithiques. Cependant, l’information disponible sur la quantité d’obsidienne présente dans les sites, les simulations mathématiques de cette distribution et l’observation des parallèles ethnographiques suggèrent l’existence d’un modèle d’échange plus complexe au cours de cette période. Dans cet article, nous utilisons l’analyse de régression pour étudier les données archéologiques et proposer l’existence d’un réseau complexe, testé par modélisation mathématique, pour expliquer les échanges d’obsidienne. À l’appui des données ethnographiques et archéologiques, on discute des implications d’ordre social et économique de ce réseau complexe d’échanges entre les villages néolithiques.
In this paper, we explore the conditions that led to the origins and development of the Near East... more In this paper, we explore the conditions that led to the origins and development of the Near Eastern Neolithic using mathematical modelling of obsidian exchange. The analysis presented expands on previous research, which established that the down-the-line model could not explain long-distance obsidian distribution across the Near East during this period. Drawing from outcomes of new simulations and their comparison with archaeological data, we provide results that illuminate the presence of complex networks of interaction among the earliest farming societies. We explore a network prototype of obsidian exchange with distant links which replicates the long-distance movement of ideas, goods and people during the Early Neolithic. Our results support the idea that during the first (Pre-Pottery Neolithic A) and second (Pre-Pottery Neolithic B) phases of the Early Neolithic, the complexity of obsidian exchange networks gradually increased. We propose then a refined model (the optimized dis...
Enhanced continental weathering (δ 7 Li, εNd) during the rise of East African complex polities: a... more Enhanced continental weathering (δ 7 Li, εNd) during the rise of East African complex polities: an early large-scale anthropogenic forcing?
Until recently, the western Arabian Peninsula has had an enigmatic role in the large-scale prehis... more Until recently, the western Arabian Peninsula has had an enigmatic role in the large-scale prehistoric exchange networks of the greater ancient Near East. New geological and archaeological data recovered from obsidian-rich zones as well as sites in south-west Arabia and beyond, have begun to elucidate the region’s unprecedented position as a regional and interregional supplier and consumer of obsidian as early as the sixth millennium BC. This paper reviews recent data on obsidian sourcing in Arabia as well as new source matches to archaeological sites in the major source zone supplying obsidian across the region, namely the Dhamār highland plains of Yemen, and discusses the results within the context of previous obsidian research. These data offer new perspectives that will allow us to broaden our understanding of the development of ancient Near Eastern societies over time, to include south-west Arabia. Furthermore, these new data provide us with a preliminary diachronic view of the...
ANALYSE piotr smolar jérusalem correspondant D' un côté, le monde. De l'autre, Israël et les répu... more ANALYSE piotr smolar jérusalem correspondant D' un côté, le monde. De l'autre, Israël et les républicains UN FRANÇAIS AU PAYS DES MOLLAHS
For more than 10 years, I was one of a number of American and Yemeni archaeologists surveying and... more For more than 10 years, I was one of a number of American and Yemeni archaeologists surveying and excavating sites dating to the fabled South Arabian kingdoms and beyond, to prehistoric times. We were members of the Dhamar Survey Project, started by the University of Chicago and named for a historic town in highland Yemen.
Rencontres internationales d’archéologie et d’histoire d’Antibes (France)
Tuesday 10 October to T... more Rencontres internationales d’archéologie et d’histoire d’Antibes (France) Tuesday 10 October to Thursday 12 October 2017
From refugia to oases: living in arid environments from prehistoric times to the present day
Organizing committee Academic: L. Purdue, J. Charbonnier, L. Khalidi (University Côte d’Azur, CNRS, CEPAM, France) Administrative: A.-M. Gomez and M. Benou (University Côte d’Azur, CNRS, CEPAM, France)
The history of human occupation in arid environments has always been inextricably tied to the history of water. From prehistory to now, populations have continuously occupied isolated spaces in proximity to watering holes, or refugia, later modifying their environments in the form of artificial niches, or oases. The objective of this conference is to investigate the natural formation of these spaces, followed by their construction and evolution as socio-economic, political and agricultural entities. The theme of this conference contributes directly to current debates on the preservation and integrated exploitation of this continually changing human heritage.
We are pleased to invite you to participate to the session “Advances in tracing the origin and ci... more We are pleased to invite you to participate to the session “Advances in tracing the origin and circulationof mineral-based prestige items in the prehistory of the Middle East and itsadjacent regions”. This session is part of the “Raw materials exploitation in Prehistory: sourcing, processing and distribution” symposium, to be held 10th-12th of March 2016 in Faro, Portugal.
Please note that the deadline for proposals will expire next October 15th, 2015.
You can find more information about submission on the symposium webpage http://www.rawmaterials2016.com/
From Refugia to Oases: living in arid environments from prehistoric times to the present day / Des refuges aux oasis: vivre en milieu aride de la Préhistoire à aujourd'hui. L. Purdue, J. Charbonnier and L. Khalidi (eds.), 2018
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Papers by Lamya Khalidi
Tuesday 10 October to Thursday 12 October 2017
From refugia to oases: living in arid environments from prehistoric times to the present day
Organizing committee
Academic: L. Purdue, J. Charbonnier, L. Khalidi (University Côte d’Azur, CNRS, CEPAM, France)
Administrative: A.-M. Gomez and M. Benou (University Côte d’Azur, CNRS, CEPAM, France)
The history of human occupation in arid environments has always been inextricably tied to the history of water. From prehistory to now, populations have continuously occupied isolated spaces in proximity to watering holes, or refugia, later modifying their environments in the form of artificial niches, or oases. The objective of this conference is to investigate the natural formation of these spaces, followed by their construction and evolution as socio-economic, political and agricultural entities. The theme of this conference contributes directly to current debates on the preservation and integrated exploitation of this continually changing human heritage.
Please note that the deadline for proposals will expire next October 15th, 2015.
You can find more information about submission on the symposium webpage http://www.rawmaterials2016.com/