BGS Karst Report Series: P1. Karst in the northern outcrop of Permian limestones

This report documents the evidence for karst and rapid groundwater flow in the northern outcrop of the Permian dolomitic limestones and their associated gypsum sequences in County Durham and a small part of North Yorkshire, in northern England. It is part of the BGS karst report series on those karst aquifers in England in which cave development is limited – principally the Upper Cretaceous Chalk and the Jurassic and Permian limestones. The term “karst” applies to rocks that are soluble. In classic karst there are extensive caves and large-scale surface karst landforms such as dolines, shafts, stream/river sinks, and springs. In the past, the Chalk and the Jurassic and Permian limestones of England were not considered karstic because they have limited cave development, and because karst features are usually small and have not been well documented. The reports provide data and information on karst in each area. There is clear evidence for karstic development in the Permian dolomitic limestones in the P1 area. Some short caves occur which appear to be fully or partially karstic in origin, and although they are now predominantly dry, they demonstrate that cave sized voids can develop in the limestones. Other caves and voids related to mass-movement are also present. There are also smaller karstic conduits, solutional fissures, dolines, dissolution pipes, stream sinks and springs present. However, there are no comprehensive datasets on these features and information on their frequency, distributions and characteristics is generally scarce. There is some further evidence that karstic networks of solutional fissures and conduits occur in the saturated zone, with some high transmissivities and yields, and large fissure inflows during construction. Both the unsaturated and saturated zones of the aquifer are impacted by karst, with a proportion of rapid recharge via surface karst features and solutional fissures, as well as some saturated zone networks of solutional conduits and fissures. These networks are likely to result in groundwater flow in unexpected directions and potentially over long distances. Considerable further work is needed to develop better datasets on karst features, and to assess the role of karst in the limestones in this area. There is more information on gypsum karst in the area, which is well-developed and poses significant engineering hazards and challenges, and also impacts on the limestones which collapse into the gypsum karst. The presence of sulphate-rich groundwater and springs indicate the interconnection of limestone and gypsum sequences in the Permian strata in the area, highlighting the complexity and connectivity between different geologies

BGS karst report series : P2. Karst in the southern outcrop of Permian limestones (and associated gypsum)

This report documents the evidence for karst and rapid groundwater flow in the southern outcrop of the Permian limestones in Northern England, together with the associated gypsum karst. It is part of the BGS karst report series on those karst aquifers in England in which cave development is limited – principally the Upper Cretaceous Chalk and the Jurassic and Permian limestones. The term “karst” applies to rocks that are soluble. In classic karst there are extensive caves and large-scale surface karst landforms such as dolines, shafts, stream/river sinks, and springs. In the past, the Chalk and the Jurassic and Permian limestones of England were not considered karstic because they have limited cave development, and because karst features are usually small and have not been well documented. These reports provide data and information on karst in each area. The Permian dolomitic limestones comprise the Cadeby Formation and the Brotherton Formation. These formations are separated by the Edlington Formation and overlain by the Roxby Formation, both of which contain extensive evaporite karst (in gypsum and anhydrite) interspersed with low permeability mudstones penetrated by karstic collapse features. This report is primarily focused on the dolomitic limestone karst, but the variable geology results in high complexity with interactions between the limestone and evaporite karst. Karst in the Permian gypsum associated with the limestones has not been well-recognised in hydrogeological studies. Evaporite karst in the area is well developed and documented with caves, dolines, and dissolution pipes. Collapse features extend into the limestones, especially in the Brotherton Formation, and there is evidence of groundwater connectivity between the evaporite and limestone karst, for example with sulphate-rich groundwater in the limestones and overlying strata. The gypsum sequences in contact with the limestones result in locally very high transmissivities and mixing of waters from the two types of karstified rocks. There is also clear evidence for karstification within the dolomitic limestones. Quite large, although short and dry, dolomitic limestone caves occur in the Cadeby Formation, with 21 karst caves recorded, ranging from 2.5 to 290 m in length. There is also evidence that smaller solutional conduits and fissures occur in the limestones which are likely to be an important component of groundwater flow. There are many other caves, some of which are formed by mass movement (slip rift caves) and some for which it is unclear whether they are mass movement caves or karst caves. In some instances, slip rift caves form a focus for recharge to the limestones, but many may be largely dry. There are significant karst stream sinks into the Cadeby Formation at Wadworth Wood near Doncaster and near Darrington, and a major karst river sink into the Cadeby Formation on the River Skell. Some limestone dolines and dissolution pipes have been recorded in the Cadeby and Brotherton formations. There are large numbers of springs in the Permian limestones, and although their flows and characteristics are generally not well documented, it appears that many are quite small, and a few may have substantial flows. Tracer tests have been carried out at one location, and these demonstrated connectivity between a groundwater abstraction and both a leaking sewer and a surface water course, over distances of 10s to 100s metres. At this locality high transmissivity, and high yields (> 80 l/s) also indicate solutional development of permeability. There are other abstractions in the P2 area with high yields and transmissivities of > 1000 m2/day suggesting they may be supplied by karstic solutional networks. Detailed borehole investigations using slug tests and water level monitoring have revealed rapid flow velocities of 13 to 242 m/day in the Cadeby Formation at the Leeds University study site, and modelling work over a wider area suggested very rapid flows of up to 9000 m/day (Medici et al 2019a,b). These studies also showed that very low effective porosities (2.8 x 10-4) are needed to represent the karstic development of permeability in the Permian limestones and the potential large scale of contaminant transport. The data collated in this report demonstrate that a component of unsaturated zone flow in the Permian limestones is rapid, but the proportion of rapid flow, and the frequency of rapid flowpaths that extend through the entire unsaturated zone, is uncertain. Evidence of cave, conduit and solutional fissure development; and some high transmissivities and high borehole yields, especially where gypsum is present, suggest that there are saturated zone networks of solutional fissures and conduits which might enable pollutant transport over long distances and in unexpected directions, but further work is needed to determine how frequently these networks occur and how extensive they are. Such networks can form along stream sink to spring flowpaths or through mixing corrosion. Overall, this report highlights the importance of karst in the Permian limestones, the complexities of the interactions with the evaporite karst, and the need for further development of karst datasets and conceptualisation of the karst hydrogeology to assist with groundwater studies and management in this area

On the Generalizability of Experimental Results

The age-old question of the generalizability of the results of experiments that are conducted in artificial laboratory settings to more realistic inferential and decision making situations is considered in this paper. Conservatism in probability revision provides an example of a result that 1) has received wide attention, including attention in terms of implications for real-world decision making, on the basis of experiments conducted in artificial settings and 2) is now apparently thought by many to be highly situational and not at all a ubiquitous phenomenon, in which case its implications for real-world decision making are not as extensive as originally claimed. In this paper we consider the questions of generalizations from the laboratory to the real world in some detail, both within the context of the experiments regarding conservatism and within a more general context. In addition, we discuss some of the difficulties inherent in experimentation in realistic settings, suggest possible procedures for avoiding or at least alleviating such difficulties, and make a plea for more realistic experiments

Experimental Facilities Development

This research was sponsored by the National Science Foundation Grant NSF PHY 87-1440

Phenomenology of the Lense-Thirring effect in the Solar System

Recent years have seen increasing efforts to directly measure some aspects of the general relativistic gravitomagnetic interaction in several astronomical scenarios in the solar system. After briefly overviewing the concept of gravitomagnetism from a theoretical point of view, we review the performed or proposed attempts to detect the Lense-Thirring effect affecting the orbital motions of natural and artificial bodies in the gravitational fields of the Sun, Earth, Mars and Jupiter. In particular, we will focus on the evaluation of the impact of several sources of systematic uncertainties of dynamical origin to realistically elucidate the present and future perspectives in directly measuring such an elusive relativistic effect.Comment: LaTex, 51 pages, 14 figures, 22 tables. Invited review, to appear in Astrophysics and Space Science (ApSS). Some uncited references in the text now correctly quoted. One reference added. A footnote adde

Implementation Evaluation of a Complex Intervention to Improve Timeliness of Care for Veterans with Transient Ischemic Attack

Background: The Protocol-guided Rapid Evaluation of Veterans Experiencing New Transient Neurologic Symptoms (PREVENT) program was designed to address systemic barriers to providing timely guideline-concordant care for patients with transient ischemic attack (TIA). Objective: We evaluated an implementation bundle used to promote local adaptation and adoption of a multi-component, complex quality improvement (QI) intervention to improve the quality of TIA care Bravata et al. (BMC Neurology 19:294, 2019). Design: A stepped-wedge implementation trial with six geographically diverse sites. Participants: The six facility QI teams were multi-disciplinary, clinical staff. Interventions: PREVENT employed a bundle of key implementation strategies: team activation; external facilitation; and a community of practice. This strategy bundle had direct ties to four constructs from the Consolidated Framework for Implementation Research (CFIR): Champions, Reflecting & Evaluating, Planning, and Goals & Feedback. Main measures: Using a mixed-methods approach guided by the CFIR and data matrix analyses, we evaluated the degree to which implementation success and clinical improvement were associated with implementation strategies. The primary outcomes were the number of completed implementation activities, the level of team organization and > 15 points improvement in the Without Fail Rate (WFR) over 1 year. Key results: Facility QI teams actively engaged in the implementation strategies with high utilization. Facilities with the greatest implementation success were those with central champions whose teams engaged in planning and goal setting, and regularly reflected upon their quality data and evaluated their progress against their QI plan. The strong presence of effective champions acted as a pre-condition for the strong presence of Reflecting & Evaluating, Goals & Feedback, and Planning (rather than the other way around), helping to explain how champions at the +2 level influenced ongoing implementation. Conclusions: The CFIR-guided bundle of implementation strategies facilitated the local implementation of the PREVENT QI program and was associated with clinical improvement in the national VA healthcare system

Thorium speciation in seawater

Author Posting. © The Authors, 2006. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Marine Chemistry 100 (2006): 250-268, doi:10.1016/j.marchem.2005.10.024.Since the 1960’s, thorium isotopes occupy a special place in the oceanographer’s toolbox as tracers for determining rates and mechanisms of oceanic scavenging, particle dynamics, and carbon fluxes. Due to their unique and constant production rates from soluble parent nuclides of uranium and radium, their disequilibrium can be used to calculate rates and time scales of sinking particles. In addition, by ratio-ing particulate 234Th (as well, in principle, other Thnuclides) to carbon (and other elements), and linking this ratio to the parent-daughter disequilibrium in the water column, it is possible to calculate fluxes of carbon and other elements. Most of these applications are possible with little knowledge of the dissolved chemical properties of thorium, other than its oxidation state (IV) and tendency to strongly sorb to surfaces, i.e., its “particle- or surface-activity”. However, the use of any tracer is hindered by a lack of knowledge of its chemical properties. Recent observations in the variability of carbon to 234Th ratios in different particle types, as well as of associations of Th(IV) with various marine organic biomolecules has led to the need for a review of current knowledge and what future endeavors should be taken to understand the marine chemistry of thorium.The writing of this paper was supported, in parts by NSF (OCE-0351559; OCE-0350758, and OCE 0354757)

Collisional and Radiative Processes in Optically Thin Plasmas

Most of our knowledge of the physical processes in distant plasmas is obtained through measurement of the radiation they produce. Here we provide an overview of the main collisional and radiative processes and examples of diagnostics relevant to the microphysical processes in the plasma. Many analyses assume a time-steady plasma with ion populations in equilibrium with the local temperature and Maxwellian distributions of particle velocities, but these assumptions are easily violated in many cases. We consider these departures from equilibrium and possible diagnostics in detail

Designing a broad-spectrum integrative approach for cancer prevention and treatment

Targeted therapies and the consequent adoption of "personalized" oncology have achieved notablesuccesses in some cancers; however, significant problems remain with this approach. Many targetedtherapies are highly toxic, costs are extremely high, and most patients experience relapse after a fewdisease-free months. Relapses arise from genetic heterogeneity in tumors, which harbor therapy-resistantimmortalized cells that have adopted alternate and compensatory pathways (i.e., pathways that are notreliant upon the same mechanisms as those which have been targeted). To address these limitations, aninternational task force of 180 scientists was assembled to explore the concept of a low-toxicity "broad-spectrum" therapeutic approach that could simultaneously target many key pathways and mechanisms. Using cancer hallmark phenotypes and the tumor microenvironment to account for the various aspectsof relevant cancer biology, interdisciplinary teams reviewed each hallmark area and nominated a widerange of high-priority targets (74 in total) that could be modified to improve patient outcomes. For thesetargets, corresponding low-toxicity therapeutic approaches were then suggested, many of which werephytochemicals. Proposed actions on each target and all of the approaches were further reviewed forknown effects on other hallmark areas and the tumor microenvironment. Potential contrary or procar-cinogenic effects were found for 3.9% of the relationships between targets and hallmarks, and mixedevidence of complementary and contrary relationships was found for 7.1%. Approximately 67% of therelationships revealed potentially complementary effects, and the remainder had no known relationship. Among the approaches, 1.1% had contrary, 2.8% had mixed and 62.1% had complementary relationships. These results suggest that a broad-spectrum approach should be feasible from a safety standpoint. Thisnovel approach has potential to be relatively inexpensive, it should help us address stages and types ofcancer that lack conventional treatment, and it may reduce relapse risks. A proposed agenda for futureresearch is offered

Projected WIMP sensitivity of the LUX-ZEPLIN dark matter experiment

LUX-ZEPLIN (LZ) is a next-generation dark matter direct detection experiment that will operate 4850 feet underground at the Sanford Underground Research Facility (SURF) in Lead, South Dakota, USA. Using a two-phase xenon detector with an active mass of 7 tonnes, LZ will search primarily for low-energy interactions with weakly interacting massive particles (WIMPs), which are hypothesized to make up the dark matter in our galactic halo. In this paper, the projected WIMP sensitivity of LZ is presented based on the latest background estimates and simulations of the detector. For a 1000 live day run using a 5.6-tonne fiducial mass, LZ is projected to exclude at 90% confidence level spin-independent WIMP-nucleon cross sections above 1.4 × 10-48cm2 for a 40 GeV/c2 mass WIMP. Additionally, a 5σ discovery potential is projected, reaching cross sections below the exclusion limits of recent experiments. For spin-dependent WIMP-neutron(-proton) scattering, a sensitivity of 2.3 × 10−43 cm2 (7.1 × 10−42 cm2) for a 40 GeV/c2 mass WIMP is expected. With underground installation well underway, LZ is on track for commissioning at SURF in 2020