A Chaotic-Dynamical Conceptual Model to Describe Fluid flow and Contaminant Transport in a Fractured Vadose zone

(1) To determine if and when dynamical chaos theory can be used to investigate infiltration of fluid and contaminant transport in heterogeneous soils and fractured rocks. (2) To introduce a new approach to the multiscale characterization of flow and transport in fractured basalt vadose zones and to develop physically based conceptual models on a hierarchy of scales. The following activities are indicative of the success in meeting the project s objectives: A series of ponded infiltration tests, including (1) small-scale infiltration tests (ponded area 0.5 m2) conducted at the Hell s Half Acre site near Shelley, Idaho, and (2) intermediate-scale infiltration tests (ponded area 56 m2) conducted at the Box Canyon site near Arco, Idaho. Laboratory investigations and modeling of flow in a fractured basalt core. A series of small-scale dripping experiments in fracture models. Evaluation of chaotic behavior of flow in laboratory and field experiments using methods from nonlinear dynamics; Evaluation of the impact these dynamics may have on contaminant transport through heterogeneous fractured rocks and soils, and how it can be used to guide remediation efforts; Development of a conceptual model and mathematical and numerical algorithms for flow and transport that incorporate (1) the spatial variability of heterogeneous porous and fractured media, and (2) the description of the temporal dynamics of flow and transport, both of which may be chaotic. Development of appropriate experimental field and laboratory techniques needed to detect diagnostic parameters for chaotic behavior of flow. This approach is based on the assumption that spatial heterogeneity and flow phenomena are affected by nonlinear dynamics, and in particular, by chaotic processes. The scientific and practical value of this approach is that we can predict the range within which the parameters of flow and transport change with time in order to design and manage the remediation, even when we can not predict the behavior at any point or time

The chronostratigraphy of the Haua Fteah cave (Cyrenaica, northeast Libya)

The 1950s excavations by Charles McBurney in the Haua Fteah, a large karstic cave on the coast of northeast Libya, revealed a deep sequence of human occupation. Most subsequent research on North African prehistory refers to his discoveries and interpretations, but the chronology of its archaeological and geological sequences has been based on very early age determinations. This paper reports on the initial results of a comprehensive multi-method dating program undertaken as part of new work at the site, involving radiocarbon dating of charcoal, land snails and marine shell, cryptotephra investigations, optically stimulated luminescence (OSL) dating of sediments, and electron spin resonance (ESR) dating of tooth enamel. The dating samples were collected from the newly exposed and cleaned faces of the upper 7.5 m of the w14.0 m-deep McBurney trench, which contain six of the seven major cultural phases that he identified. Despite problems of sediment transport and reworking, using a Bayesian statistical model the new dating program establishes a robust framework for the five major lithostratigraphic units identified in the stratigraphic succession, and for the major cultural units. The age of two anatomically modern human mandibles found by McBurney in Layer XXXIII near the base of his Levalloiso-Mousterian phase can now be estimated to between 73 and 65 ka (thousands of years ago) at the 95.4% confidence level, within Marine Isotope Stage (MIS) 4. McBurney’s Layer XXV, associated with Upper Palaeolithic Dabban blade industries, has a clear stratigraphic relationship with Campanian Ignimbrite tephra. Microlithic Oranian technologies developed following the climax of the Last Glacial Maximum and the more microlithic Capsian in the Younger Dryas. Neolithic pottery and perhaps domestic livestock were used in the cave from the mid Holocene but there is no certain evidence for plant cultivation until the Graeco-Roman period

Risk of chronic kidney disease in children who developed acute kidney injury secondary to nephrotoxic medication exposure in infancy

AbstractIntroduction Nephrotoxic medication (NTM) is one of the common causes of acute kidney injury (AKI) in critically ill infants. Current knowledge about the long-term effects of NTM exposure and associated AKI during the neonatal period and early infancy is limited. Hence, we aimed to explore the risk of chronic kidney disease (CKD) after NTM-AKI in this age group.Methods We performed a cross-sectional study including children 2–7 years of age, who had a history of high NTM exposure during NICU hospitalization. Cases and controls were defined as children who developed AKI and who did not develop AKI after NTM exposure, respectively. The primary outcome of interest was to explore the prevalence of composite CKD. In addition, we explored differences in urinary biomarker kidney injury molecule-1 (KIM-1) between the groups.Results We enrolled 48 children, 18 cases and 30 controls in which 25/48 (52%) had at least one finding of CKD. The composite CKD outcome tended to be higher in cases vs controls (61.1% vs. 46.6%, odds ratio = 1.79 (95% confidence interval 0.54-5.8)); however, this was not statistically significant. Median urinary KIM-1 value trended higher in controls, 0.367(0.23-0.59) vs. 0.20 (IQR 0.11-0.47), which was not statistically significant.Conclusion In this study, 52% of children exposed to NTM had at least one marker of CKD at a median age of 5 years. Multicenter, large prospective studies are needed to improve our understanding of the natural course of NTM-AKI and to determine risk factors and strategies to reduce CKD in this high-risk population

Implementation strategies for baby NINJA (nephrotoxic injury negated by just-in-time action) to prevent neonatal medication-induced kidney injury

Acute kidney injury (AKI) is a common complication among patients admitted to the neonatal intensive care unit. Nephrotoxic medications (NTMs) are known to increase the incidence of AKI, but the use of these -medications is often unavoidable. Baby NINJA (Nephrotoxic Injury Negated by Just-in-Time Action) is a -quality improvement (QI) project that may be implemented at individual institutions and aims to systematically identify AKI in neonates and infants receiving NTMs. The purpose of this review is to describe nephrotoxic AKI in the neonatal population, introduce the Baby NINJA QI project and its potential to reduce neonatal AKI, and outline strategies for effective implementation of Baby NINJA