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

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

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 reports on three research projects.Defense Advanced Research Projects Agency DABT 63-95-C-0088Defense Advanced Research Projects Agency N00174-93-K-0035Stanford UniversityLeaders for Manufacturing Progra

Effects of nitrogen and potassium fertilization on the susceptibility of tomatoes to post-harvest proliferation of Salmonella enterica

Fresh fruits and vegetables are increasingly recognized as vehicles of salmonellosis. Pre- and post-harvest environmental conditions, and physiological, and genetic factors are thought to contribute to the ability of human pathogens to persist in the production environment, attach to, colonize and proliferate in and on raw produce. How field production conditions affect the post-harvest food safety outcomes is not entirely understood. This study tested how varying nitrogen and potassium fertilization levels affected the "susceptibility" of tomatoes to Salmonella infections following the harvest of fruits. Two tomato varieties grown over three seasons under high, medium, and low levels of nitrogen and potassium fertilization in two locations were inoculated with seven strains of Salmonella. Even though the main effects of nitrogen and potassium fertilization on the susceptibility of tomatoes to infections with Salmonella enterica were not statistically significant overall, differences in nitrogen concentrations in plant tissues correlated with the susceptibility of partially ripe tomatoes (cv. Solar Fire) to Salmonella. Tomato maturity and the season in which tomatoes were produced had the strongest effect on the ability of Salmonella to multiply in tomatoes. Tomato phenolics, accumulation of which is known to correlate with rates of the N fertilization, did not inhibit growth of Salmonella in vitro

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

Factors that affect proliferation of Salmonella in tomatoes post-harvest: the roles of seasonal effects, irrigation regime, crop and pathogen genotype

MAIN OBJECTIVES: Fresh fruits and vegetables become increasingly recognized as vehicles of human salmonellosis. Physiological, ecological, and environmental factors are all thought to contribute to the ability of Salmonella to colonize fruits and vegetables pre- and post-harvest. The goal of this study was to test how irrigation levels, fruit water congestion, crop and pathogen genotypes affect the ability of Salmonella to multiply in tomatoes post-harvest. EXPERIMENTAL DESIGN: Fruits from three tomato varieties, grown over three production seasons in two Florida locations, were infected with seven strains of Salmonella and their ability to multiply post-harvest in field-grown tomatoes was tested. The field experiments were set up as a two-factor factorial split plot experiment, with the whole-plot treatments arranged in a randomized complete-block design. The irrigation treatment (at three levels) was the whole-plot factor, and the split-plot factor was tomato variety, with three levels. The significance of the main, two-way, and three-way interaction effects was tested using the (type III) F-tests for fixed effects. Mean separation for each significant fixed effect in the model was performed using Tukey's multiple comparison testing procedure. MOST IMPORTANT DISCOVERIES AND SIGNIFICANCE: The irrigation regime per se did not affect susceptibility of the crop to post-harvest proliferation of Salmonella. However, Salmonella grew significantly better in water-congested tissues of green tomatoes. Tomato maturity and genotype, Salmonella genotype, and inter-seasonal differences were the strongest factors affecting proliferation. Red ripe tomatoes were significantly and consistently more conducive to proliferation of Salmonella. Tomatoes harvested in the driest, sunniest season were the most conducive to post-harvest proliferation of the pathogen. Statistically significant interactions between production conditions affected post-harvest susceptibility of the crop to the pathogen. UV irradiation of tomatoes post-harvest promoted Salmonella growth

Biomedical and therapeutic applications of biosurfactants

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