168 research outputs found

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

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    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

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

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    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

    Time sequence ordering extensions to the Entity-Relationship model and their application to the automated manufacturing process

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    New extensions to the entity-relationship (E-R) model have been developed to represent time sequencing and ordering aspects of information flow, and to represent the integration of control (programming) information into a database. The model constructs specify an implementation ordering of records in a relational database table. Time sequencing refers to an implementation of process information flow as a result of this ordering. The modeling constructs are needed to more completely model process recipe information flow in a typical automated manufacturing facility. The development of these E-R extensions is pursued using a data model for the factory of the future as a motivation and development vehicle. The extensions are defined formally and possible variations of the constructs are given. Further, the incorporation of the constructs into the existing E-R model semantics and the transformation of these extensions to ordering properties and integrity constraints on a corresponding database implementation is discussed.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/29158/1/0000203.pd

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

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    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

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

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    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-Integrated Design and Manufacture of Integrated Circuits

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    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

    Biomedical and therapeutic applications of biosurfactants

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    During the last years, several applications of biosurfactants with medical purposes have been reported. Biosurfactants are considered relevant molecules for applications in combating many diseases and as therapeutic agents due to their antibacterial, antifungal and antiviral activities. Furthermore, their role as anti-adhesive agents against several pathogens illustrate their utility as suitable anti-adhesive coating agents for medical insertional materials leading to a reduction of a large number of hospital infections without the use of synthetic drugs and chemicals. Biomedical and therapeutic perspectives of biosurfactants applications are presented and discussed in this chapter

    Developing manufacturing control software: A survey and critique

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    The complexity and diversity of manufacturing software and the need to adapt this software to the frequent changes in the production requirements necessitate the use of a systematic approach to developing this software. The software life-cycle model (Royce, 1970) that consists of specifying the requirements of a software system, designing, implementing, testing, and evolving this software can be followed when developing large portions of manufacturing software. However, the presence of hardware devices in these systems and the high costs of acquiring and operating hardware devices further complicate the manufacturing software development process and require that the functionality of this software be extended to incorporate simulation and prototyping.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/45542/1/10696_2005_Article_BF01328739.pd

    Effects of chemical pre-treatments on modified starch granules: recommendations for dental calculus decalcification for ancient starch research

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    Starch granules and other plant microremains embedded in dental calculus provide information about the diet and culinary practices of past individuals. While most researchers use either hydrochloric acid (HCl) or ethylenediaminetetraacetic acid (EDTA) to demineralise samples and release embedded microremains, protocols vary significantly in regard to chemical concentration and duration. Furthermore, there are conflicting reports concerning the suitability of these chemicals for archaeological starch analyses, particularly when granules are modified (damaged) such as from food processing or enzymatic digestion. This study tests 0.5 M HCl and 0.5 M EDTA on modified modern wheat, chickpea and potato starch with direct observation of individual starch granules over 168 h, the maximum duration reported so far for full decalcification of archaeological calculus samples. While there were no observable changes to gross morphological characteristics of any granules, metric analysis indicates slight changes to average granule size in milled potato and wheat starch in all solutions. Furthermore, interactions between the chemical reagent and ions released from the calculus matrix have the potential to result in the diminished recovery of archaeological starch from HCl extractions. We recommend that of these two chemical decalcification options, EDTA is more suitable for processing archaeological dental calculus for starch microremains as it chelates ions released during decalcification of the calculus matrix that might otherwise adversely affect archaeological starch granules.1. Introduction 2. Previous research on the effects of HCl and EDTA on starch granules 3. Materials and methods 4. Results and discussion 4.1. Differential effects of HCl and EDTA on native and modified starch 4.2. Why does EDTA yield higher microremain counts from calculus than HCl? 5. Conclusio
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