Microbotanical signatures of kreb: differentiating inflorescence phytoliths from northern African wild grasses

Throughout northern Africa, evidence for an intensification of wild grass gathering is reflected in Holocene archaeological contexts. However, both the recovery of macrobotanical assemblages and the specificity of their taxonomic classification are heavily influenced by food processing and post-depositional conditions. In contrast, inflorescence phytoliths provide high levels of taxonomic specificity and preserve well in most archaeological contexts. This study analyses the in situ morphology of inflorescence phytoliths from modern specimens of nine wild C4 grass species commonly observed in ethnographic studies and recovered in seed assemblages from archaeological contexts across northern Africa. Morphological differences in Interdigitate phytoliths within the fertile florets of six Paniceae species enabled differentiation between them. The morphological parameters established in this study provide an additional resource for archaeological and palaeoecological analyses using phytoliths, which demonstrates the effectiveness of applying this method to African wild grass species.Introduction Materials and methods - Selected species - Sample preparation and analysis - Phytolith nomenclature Results Variations in phytolith occurrence between inflorescence bracts - Glumes - Lemmas - Paleas Classification of Interdigitate morphotypes Discussion Conclusion

New porous medium Poisson-Nernst-Planck equations for strongly oscillating electric potentials

We consider the Poisson-Nernst-Planck system which is well-accepted for describing dilute electrolytes as well as transport of charged species in homogeneous environments. Here, we study these equations in porous media whose electric permittivities show a contrast compared to the electric permittivity of the electrolyte phase. Our main result is the derivation of convenient low-dimensional equations, that is, of effective macroscopic porous media Poisson-Nernst-Planck equations, which reliably describe ionic transport. The contrast in the electric permittivities between liquid and solid phase and the heterogeneity of the porous medium induce strongly oscillating electric potentials (fields). In order to account for this special physical scenario, we introduce a modified asymptotic multiple-scale expansion which takes advantage of the nonlinearly coupled structure of the ionic transport equations. This allows for a systematic upscaling resulting in a new effective porous medium formulation which shows a new transport term on the macroscale. Solvability of all arising equations is rigorously verified. This emergence of a new transport term indicates promising physical insights into the influence of the microscale material properties on the macroscale. Hence, systematic upscaling strategies provide a source and a prospective tool to capitalize intrinsic scale effects for scientific, engineering, and industrial applications

A new CP-approach for a parallel machine scheduling problem with time constraints on machine qualifications

International audienceThis paper considers the scheduling of job families on parallel machines with time constraints on machine qualifications. In this problem, each job belongs to a family and a family can only be executed on a subset of qualified machines. In addition, machines can lose their qualifications during the schedule. Indeed, if no job of a family is scheduled on a machine during a given amount of time, the machine loses its qualification for this family. The goal is to minimize the sum of job completion times, i.e. the flow time, while maximizing the number of qualifications at the end of the schedule. The paper presents a new Constraint Programming (CP) model taking more advantages of the CP feature to model machine disqualifications. This model is compared with two existing models: an Integer Linear Programming (ILP) model and a Constraint Programming model. The experiments show that the new CP model outperforms the other model when the priority is given to the number of disqualifications objective. Furthermore, it is competitive with the other model when the flow time objective is prioritized

Revisiting Kalundu Mound, Zambia: implications for the timing of social and subsistence transitions in Iron Age Southern Africa

Novel trajectories of food production, urbanism, and inter-regional trade fueled the emergence of numerous complex Iron Age polities in central and southern Africa. Renewed research and re-dating efforts in Botswana, Zimbabwe, and along the Swahili Coast are transforming models for how inter-regional interaction spheres contributed to these patterns. While societies in present-day Zambia played an important role in the trade of copper, ivory, gold, and other resources between central and southern Africa, little is known about lifeways during the rise of social complexity in this region. This paper reports the results of re-excavation at Kalundu Mound on the Batoka Plateau of southern Zambia, one of the iconic mound sites of the Iron Age “Kalomo Culture.” New radiocarbon dates were combined with the original dates in a series of Bayesian models, indicating that previous chronologies for the site are not reliable and that the mound site likely developed rapidly from AD 1190 to 1410. Archaeobotanical, zooarchaeological, and paleo-proteomic analyses of excavated materials suggests a broad subsistence base combining wild and domesticated species, including the first reported evidence for finger millet (Eleusine coracana) in the region. Considering these findings, it is necessary to re-evaluate the temporal context of the Kalomo site-group, and to also systematically reinvestigate the systems of exchange and subsistence that supported Later Iron Age complexity.Introduction Situating Kalundu Mound Within the Regional Archaeology Kalundu Mound and the Kalomo Culture - Environmental Setting and Regional History - The 1957 Excavations - The 1960–1962 Excavations - The 2017 Excavations Results - Stratigraphy - Chronology - Chronological Modeling Results - Chronology Summary Subsistence - Faunal Remains - Macrobotanical Remains - Material culture Discussion - Site Formation - Iron Age Agriculture at Kalundu - Chronology for Kalundu Mound and the Kalomo Group Conclusio

The second season of excavations at Jebel Moya (south-central Sudan)

This report presents the latest data from ongoing excavations at Jebel Moya, Sudan. This year saw the opening of five new trenches and continued excavation of an archaeologically rich trench. We have recovered four individual burials, a mud brick wall and a number of animal and archaeobotanical remains. The excavations also yielded a longer pottery sequence, showing clearly that the site was in use by at least the sixth millennium BC. This season confirms the long and complex history of Jebel Moya and provides the material for future studies on population health and subsistence. This season also saw an increase in community engagement and a more detailed study of the various historical trajectories that make up the biography of Jebel Moya

Revisiting Kalundu Mound, Zambia: Implications for the Timing of Social and Subsistence Transitions in Iron Age Southern Africa

Novel trajectories of food production, urbanism, and inter-regional trade fueled the emergence of numerous complex Iron Age polities in central and southern Africa. Renewed research and re-dating efforts in Botswana, Zimbabwe, and along the Swahili Coast are transforming models for how inter-regional interaction spheres contributed to these patterns. While societies in present-day Zambia played an important role in the trade of copper, ivory, gold, and other resources between central and southern Africa, little is known about lifeways during the rise of social complexity in this region. This paper reports the results of re-excavation at Kalundu Mound on the Batoka Plateau of southern Zambia, one of the iconic mound sites of the Iron Age “Kalomo Culture.” New radiocarbon dates were combined with the original dates in a series of Bayesian models, indicating that previous chronologies for the site are not reliable and that the mound site likely developed rapidly from AD 1190 to 1410. Archaeobotanical, zooarchaeological, and paleo-proteomic analyses of excavated materials suggests a broad subsistence base combining wild and domesticated species, including the first reported evidence for finger millet (Eleusine coracana) in the region. Considering these findings, it is necessary to re-evaluate the temporal context of the Kalomo site-group, and to also systematically reinvestigate the systems of exchange and subsistence that supported Later Iron Age complexity

Computer-Assisted Prototyping of Advanced Microsystems

Contains reports on five research projects.Defense Advanced Research Projects Agency Contract DABT 63-95-C-0088Stanford Universit

Computer-Integrated Design and Manufacture of Integrated Circuits

Contains research goals and objectives, reports on sixteen research projects and a list of publications.Defense Advanced Research Projects Agency/U.S. Navy Contract N00174-93-K-0035Defense Advanced Research Projects Agency/U.S. Army Contract DABT 63-95-C-0088Multisponsored Projects Industrial/MIT Leaders for Manufacturing Progra