277 research outputs found

    Shelley and Berkeley: The Platonic Connection

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    [Δεν διατίθεται περίληψη / no abstract available

    Coastal Subsistence, Maritime Trade, and the Colonization of Small Offshore Islands in Eastern African Prehistory

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    Recent archaeological research has firmly established eastern Africa's offshore islands as important localities for understanding the region's pre-Swahili maritime adaptations and early Indian Ocean trade connections. While the importance of the sea and small offshore islands to the development of urbanized and mercantile Swahili societies has long been recognized, the formative stages of island colonization—and in particular the processes by which migrating Iron Age groups essentially became “maritime”—are still relatively poorly understood. Here we present the results of recent archaeological fieldwork in the Mafia Archipelago, which aims to understand these early adaptations and situate them within a longer-term trajectory of island settlement and pre-Swahili cultural developments. We focus on the results of zooarchaeological, archaeobotanical, and material culture studies relating to early subsistence and trade on this island to explore the changing significance of marine resources to the local economy. We also discuss the implications of these maritime adaptations for the development of local and long-distance Indian Ocean trade networks

    On the chronological structure of the solutrean in Southern Iberia

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    The Solutrean techno-complex has gained particular significance over time for representing a clear demographic and techno-typological deviation from the developments occurred during the course of the Upper Paleolithic in Western Europe. Some of Solutrean's most relevant features are the diversity and techno-typological characteristics of the lithic armatures. These have been recurrently used as pivotal elements in numerous Solutrean-related debates, including the chronological organization of the techno-complex across Iberia and Southwestern France. In Southern Iberia, patterns of presence and/or absence of specific point types in stratified sequences tend to validate the classical ordering of the techno-complex into Lower, Middle and Upper phases, although some evidence, namely radiocarbon determinations, have not always been corroborative. Here we present the first comprehensive analysis of the currently available radiocarbon data for the Solutrean in Southern Iberia. We use a Bayesian statistical approach from 13 stratified sequences to compare the duration, and the start and end moments of each classic Solutrean phase across sites. We conclude that, based on the current data, the traditional organization of the Solutrean cannot be unquestionably confirmed for Southern Iberia, calling into doubt the status of the classically defined type-fossils as precise temporal markers.Fundacao para a Ciencia e Tecnologia [PTDC/HAH/64184/2006, PTDC/HIS-ARQ/117540/2010, SFRH/BD/65527/2009, SFRH/BPD/96277/2013]; National Geographic Society [8045-06]; Wenner-Gren Foundation for Anthropological Research [8290

    Radiocarbon dates for the late Pleistocene and Early Holocene occupations of Cova Rosa (Ribadesella, Asturias, Spain)

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    Four excavations have been performed at the archaeological site of Cova Rosa (Asturias, Cantabrian Spain): three of them in the second half of last century and the other in this decade. Although little of the archaeological material found in those excavations has been published, here we attempt the stratigraphic correlation of sections revealed by the different excavations and we present 22 new radiocarbon dates for bones and marine shells, built in a Bayesian statistical model. This has enabled the documentation of occupations that mainly took place during the Last Glacial period, in the Solutrean (middle and upper phases) and Magdalenian (archaic, lower, and upper phases), and also in the early Holocene (Mesolithic). These occupations are compared with the record at other sites in Cantabrian Spain in general and in Asturias, in particular.Introduction Cova Rosa Cave - Geographical and Geological Setting - History of Research - Stratigraphy Radiocarbon dates at Cova Rosa - Method - Validity Analysis - Results and Critical Assessment - Solutrean - Magdalenian - Mesolithic Discussion: 14C chronology of Cova Rosa Conclusion

    An integrated, multi-modelling approach for the assessment of water quality: lessons from the Pinios River case in Greece

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    Major factors influencing water quality along a river are land use practices, seasonal hydro-meteorological conditions, groundwater interactions and wastewater discharges. These complex water quantity and water quality aspects demand integrated solution approaches. The study links hydrologic, hydraulic and water quality models using the OpenMI standard to evaluate water quality in the Pinios River in Greece. OpenMI allows data to be exchanged at run time, between models from different providers, thus facilitating integrated modelling. The Pinios River was selected due to its high intensity of cultivation with water demanding crops. The objectives of the overall project, of which this study forms a part, were to assess water quality during extreme events and identify areas where any further pollution could be critical. A multi-modelling approach was utilized, where two separate integrated models were developed by two different research groups, each combining, using OpenMI, commercial and academic model components, thus creating a form of modelling ensemble. The assumptions and results are compared and critically discussed. The study’s conclusions also address generic integrated modelling issues such as the benefit of bi-directional links and integrated model stability. They also identify challenges in model comparison, within a multi-modelling framework in view of differences in conceptualization, discretisation and solving schemes chosen by different researchers, which become apparent once the barriers for direct comparison are alleviated, with the use of approaches such as OpenMI

    An integrated, multi-modelling approach for the assessment of water quality: lessons from the Pinios River case in Greece

    Get PDF
    Major factors influencing water quality along a river are land use practices, seasonal hydro-meteorological conditions, groundwater interactions and wastewater discharges. These complex water quantity and water quality aspects demand integrated solution approaches. The study links hydrologic, hydraulic and water quality models using the OpenMI standard to evaluate water quality in the Pinios River in Greece. OpenMI allows data to be exchanged at run time, between models from different providers, thus facilitating integrated modelling. The Pinios River was selected due to its high intensity of cultivation with water demanding crops. The objectives of the overall project, of which this study forms a part, were to assess water quality during extreme events and identify areas where any further pollution could be critical. A multi-modelling approach was utilized, where two separate integrated models were developed by two different research groups, each combining, using OpenMI, commercial and academic model components, thus creating a form of modelling ensemble. The assumptions and results are compared and critically discussed. The study’s conclusions also address generic integrated modelling issues such as the benefit of bi-directional links and integrated model stability. They also identify challenges in model comparison, within a multi-modelling framework in view of differences in conceptualization, discretisation and solving schemes chosen by different researchers, which become apparent once the barriers for direct comparison are alleviated, with the use of approaches such as OpenMI

    Lipid nanoparticle-mediated messenger RNA delivery for ex vivo engineering of natural killer cells

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    Natural killer (NK) cells participate in the immune system by eliminating cancer and virally infected cells through germline-encoded surface receptors. Their independence from prior activation as well as their significantly lower toxicity have placed them in the spotlight as an alternative to T cells for adoptive cell therapy (ACT). Engineering NK cells with mRNA has shown great potential in ACT by enhancing their tumor targeting and cytotoxicity. However, mRNA transfection of NK cells is challenging, as the most common delivery methods, such as electroporation, show limitations. Therefore, an alternative non-viral delivery system that enables high mRNA transfection efficiency with preservation of the cell viability would be beneficial for the development of NK cell therapies. In this study, we investigated both polymeric and lipid nanoparticle (LNP) formulations for eGFP-mRNA delivery to NK cells, based on a dimethylethanolamine and diethylethanolamine polymeric library and on different ionizable lipids, respectively. The mRNA nanoparticles based on cationic polymers showed limited internalization by NK cells and low transfection efficiency. On the other hand, mRNA-LNP formulations were optimized by tailoring the lipid composition and the microfluidic parameters, resulting in a high transfection efficiency (∼100%) and high protein expression in NK cells. In conclusion, compared to polyplexes and electroporation, the optimized LNPs show a greater transfection efficiency and higher overall eGFP expression, when tested in NK (KHYG-1) and T (Jurkat) cell lines, and cord blood-derived NK cells. Thus, LNP-based mRNA delivery represents a promising strategy to further develop novel NK cell therapies

    Distinguishing African bovids using Zooarchaeology by Mass Spectrometry (ZooMS): new peptide markers and insights into Iron Age economies in Zambia

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    Assessing past foodways, subsistence strategies, and environments depends on the accurate identification of animals in the archaeological record. The high rates of fragmentation and often poor preservation of animal bones at many archaeological sites across sub-Saharan Africa have rendered archaeofaunal specimens unidentifiable beyond broad categories, such as “large mammal” or “medium bovid”. Identification of archaeofaunal specimens through Zooarchaeology by Mass Spectrometry (ZooMS), or peptide mass fingerprinting of bone collagen, offers an avenue for identification of morphologically ambiguous or unidentifiable bone fragments from such assemblages. However, application of ZooMS analysis has been hindered by a lack of complete reference peptide markers for African taxa, particularly bovids. Here we present the complete set of confirmed ZooMS peptide markers for members of all African bovid tribes. We also identify two novel peptide markers that can be used to further distinguish between bovid groups. We demonstrate that nearly all African bovid subfamilies are distinguishable using ZooMS methods, and some differences exist between tribes or sub-tribes, as is the case for Bovina (cattle) vs. Bubalina (African buffalo) within the subfamily Bovinae. We use ZooMS analysis to identify specimens from extremely fragmented faunal assemblages from six Late Holocene archaeological sites in Zambia. ZooMS-based identifications reveal greater taxonomic richness than analyses based solely on morphology, and these new identifications illuminate Iron Age subsistence economies c. 2200–500 cal BP. While the Iron Age in Zambia is associated with the transition from hunting and foraging to the development of farming and herding, our results demonstrate the continued reliance on wild bovids among Iron Age communities in central and southwestern Zambia Iron Age and herding focused primarily on cattle. We also outline further potential applications of ZooMS in African archaeology.Introduction Faunal identifications and key research questions ZooMS in African archaeology Materials & methods Collagen extraction and digestion Peptide mass fingerprinting LC-MS/MS Biomarker identification and confirmation Identification of archaeological samples Results and discussion - Data quality control - Distinguishing among bovid groups Comparison with published markers ZooMS analysis and archaeofaunal identifications Herding economies and the persistence of hunting in Iron Age Zambia Conclusio

    A Zymomonas mobilis mutant with delayed growth on high glucose concentrations

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    Exponentially growing cells of Zymomonas mobilis normally exhibit a lag period of up to 3 h when transferred from 0.11 M (2%) to 0.55 M (10%) glucose liquid medium. A mutant of Z, mobilis (CU1Rif2), fortuitously isolated, showed more than a 20-h lag period when grown under the same conditions, whereas on 0.55 M glucose solid medium, it failed to grow. The growth of CU1Rif2 on elevated concentrations of other fermentable (0.55 M sucrose or fructose) or nonfermentable (0.11 M glucose plus 0.44 M maltose or xylose) sugars appeared to be normal, Surprisingly, CU1Rif2 cells grew without any delay on 0.55 M glucose on which wild-type cells had been incubated for 3 h and removed at the beginning of their exponential phase. This apparent preconditioning was not observed with medium obtained from wild-type cells grown on 0.11 M glucose and supplemented to 0.55 M after removal of the wild-type cells. Undelayed growth of CU1Rif2 on 0.55 M glucose previously conditioned by the wild type was impaired by heating or protease treatment. It is suggested that in Z, mobilis, a diffusible proteinaceous heat-labile factor, transitionally not present in 0.55 M glucose CU1Rif2 cultures, triggers growth on 0.55 M glucose. Biochemical analysis of glucose uptake and glycolytic enzymes implied that glucose assimilation was not directly involved in the phenomenon. By use of a wild-type Z. mobilis genomic library, a 4.5-kb DNA fragment which complemented in low copy number the glucose-defective phenotype as well as glucokinase and glucose uptake of CU1Rif2 was isolated. This fragment carries a gene cluster consisting of Four putative coding regions, encoding 167, 167, 145, and 220 amino acids with typical Z, mobilis codon usage, -35 and -10 promoter elements, and individual Shine-Dalgarno consensus sites. However, strong homologies were not deterred in a BLAST2 (EMBL-Heidelberg) computer search with known protein sequences.J Bacterio
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