Experimental Design and Observation for Large Systems Bates, R. A.; Buck, R. J.; Riccomagno, E. ...
Journal of the Royal Statistical Society. Series B, Methodological,
01/1996, Letnik:
58, Številka:
1
Journal Article
Recenzirano
Large systems require new methods of experimental designs suitable for the highly adaptive models which are employed to cope with complex non-linear responses and high dimensionality of input spaces. ...The area of computer experiments has started to provide such designs especially Latin hypercube and lattice designs. System decomposition, prevalent in several branches of engineering, can be employed to decrease complexity. A combination of system decomposition using a sparse matrix method, experimental design and modelling is applied to one example of an electrical circuit simulator producing a usable emulator of the circuit for use in optimization and sensitivity analysis.
To compare stereoscopic digital mammography (DM) with standard DM for the rate of patient recall and the detection of cancer in a screening population at elevated risk for breast cancer.
Starting in ...September 2004 and ending in December 2007, this prospective HIPAA-compliant, institutional review board-approved screening trial, with written informed consent, recruited female patients at elevated risk for breast cancer (eg, personal history of breast cancer or breast cancer in a close relative). A total of 1298 examinations from 779 patients (mean age, 58.6 years; range, 32-91 years) comprised the analyzable data set. A paired study design was used, with each enrolled patient serving as her own control. Patients underwent both DM and stereoscopic DM examinations in a single visit, findings of which were interpreted independently by two experienced radiologists, each using a Breast Imaging Reporting and Data System (BI-RADS) assessment (BI-RADS category 0, 1, or 2). All patients determined to have one or more findings with either or both modalities were recalled for standard diagnostic evaluation. The results of 1-year follow-up or biopsy were used to determine case truth.
Compared with DM, stereoscopic DM showed significantly higher specificity (91.2% 1167 of 1279 vs 87.8% 1123 of 1279; P = .0024) and accuracy (90.9% 1180 of 1298 vs 87.4% 1135 of 1298; P = .0023) for detection of cancer. Sensitivity for detection of cancer was not significantly different for stereoscopic DM (68.4% 13 of 19) compared with DM (63.2% 12 of 19, P .99). The recall rate for stereoscopic DM was 9.6% (125 of 1298) and that for DM was 12.9% (168 of 1298) (P = .0018).
Compared with DM, stereoscopic DM significantly improved specificity for detection of cancer, while maintaining comparable sensitivity. The recall rate was significantly reduced with stereoscopic DM compared with DM.
http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.12120382/-/DC1.
Anderson and Prelli argued that pentadic cartography could be used to examine the motivational vocabularies of discourses and to provide alternative vocabularies for negotiating rhetorical terrains. ...Applications of pentadic cartography have used Kenneth Burke's principles to examine and critique the motivational vocabularies of a variety of texts but have less often mapped proposed alternative vocabularies. This article expands the application of pentadic cartography by demonstrating the value of a full mapping process. This study examines two potential mappings of former Secretary of Health and Human Services Michael Leavitt's speech outlining US health diplomacy. Two maps are generated: a pragmatic map centered on an agency-purpose ratio and an idealist map centered on an agent-act ratio. Each mapping is assessed for its abilities to open and to close the universe of discourse. The importance of fully mapping humanitarian discourses is outlined.
A major uncertainty are the causes for interannual variability of the global ocean uptake of CO2. Existing estimates, based on atmospheric CO2 data, indicate that peak‐to‐peak interannual variability ...in ocean uptake of CO2 is up to 2–4 Pg C year−1 (Pg = 1015 g), while those estimates based on ocean observations and models suggest that year‐to‐year variability is much smaller (∼0.4–0.8 Pg C year−1). Here, it is shown that these differences can be partly reconciled if global air‐sea CO2 flux estimates include the CO2 flux associated with tropical cyclones (TC), extra‐tropical cyclones (ETC), and new air‐sea CO2 gas exchange relationships. The impact of storm events on air‐sea CO2 flux is influenced by climate variability such as the El Niño/Southern Oscillation (ENSO) and North Atlantic Oscillation (NAO), contributing to an interannual peak‐to‐peak variability in global ocean uptake of CO2 of up to ∼1.8 Pg C year−1.
The American public is increasingly concerned about risks associated with food additives like high-fructose corn syrup (HFCS). To promote its product as safe, the Corn Refiners Association (CRA) ...employed two forms of straw-person arguments. First, the CRA opportunistically misrepresented HFCS opposition as inept. Second, the CRA strategically chose to refute claims that were easier to defeat while remaining ambiguous about more complex points of contention. We argue that CRA's discursive contributions represented unreasonable yet sustainable use of straw-person arguments in debates surrounding health and risk.
The Niemann-Pick C (NPC) pathway plays an essential role in the intracellular trafficking of cholesterol by facilitating the release of lipoprotein-derived sterol from the lumen of lysosomes. ...Regulation of cellular cholesterol homeostasis is of particular importance to lung alveolar type II cells because of the need for production of surfactant with an appropriate lipid composition. We performed microscopic and biochemical analysis of NPC proteins in isolated rat type II pneumocytes. NPC1 and NPC2 proteins were present in the lung, isolated type II cells in culture, and alveolar macrophages. The glycosylated and nonglycosylated forms of NPC1 were prominent in the lung and the lamellar body organelles. Immunocytochemical analysis of isolated type II pneumocytes showed localization of NPC1 to the limiting membrane of lamellar bodies. NPC2 and lysosomal acid lipase were found within these organelles, as confirmed by z-stack analysis of confocal images. All three proteins also were identified in small, lysosome-like vesicles. In the presence of serum, pharmacological inhibition of the NPC pathway with compound U18666A resulted in doubling of the cholesterol content of the type II cells. Filipin staining revealed a striking accumulation of cholesterol within lamellar bodies. Thus the NPC pathway functions to control cholesterol accumulation in lamellar bodies of type II pneumocytes and, thereby, may play a role in the regulation of surfactant cholesterol content.
Surface hydrographic and biogeochemical properties were measured contemporaneously at high spatial density during a transit from Chesapeake Bay, across the Middle Atlantic Bight MAB and Gulf Stream ...to the Sargasso Sea near Bermuda from 28 September–2 October 1996. Discrete samples were collected for total organic carbon TOC, dissolved organic carbon DOC, total organic nitrogen TON, dissolved organic nitrogen DON, total carbon dioxide TCO
2 and alkalinity TA. Continuous measurements of temperature, salinity, fluorescence, seawater
pCO
2 and atmospheric
pCO
2 were also collected. Estuarine waters of Chesapeake Bay (salinity>20) had high
pCO
2 (>600 μatm) and high TOC (>200 μM), DOC (>190 μM) and TON (>20 μM) concentrations reflecting the riverine input of terrestrial organic matter. Low seawater
pCO
2 concentrations (∼350 μatm), compared to MAB waters (∼370–430 μatm), were observed in the offshore plume of the Chesapeake. High TOC, TON, TCO
2 and alkalinity concentrations were observed within a filament of low salinity shelf water abutting the western wall of the Gulf Stream. These filaments are apparently advected off the shelf near Cape Hatteras and subducted beneath the Gulf Stream. We estimate that this process will export shelf organic carbon into the North Atlantic basin at a rate ∼3–31×10
12 g C year
−1, depending on the amount of water advected off the shelf.
•MS3DATA predicts multiphase flow characteristics using simulation data.•Bubble statistics computed using novel detection and tracking algorithm.•Algorithm capabilities exemplified by application to ...bubbling fluidized bed case.•3D detection accurately captures small bubbles, slugs and their azimuthal velocity.•Algorithm is scalable and computes high-resolution statistics with insignificant cost.
Bubble dynamics play a critical role in the hydrodynamics of fluidized beds and significantly affect reactor performance. In this study, MS3DATA (Multiphase-flow Statistics using 3D Detection And Tracking Algorithm) is developed, validated and applied to numerical simulations of large-scale fluidized beds. Using this algorithm, bubbles are detected using void fraction data from simulations and are completely characterized by their size, shape and location while their velocities are computed by tracking bubbles across successive time frames. A detailed analysis of 2D (across vertical sections) and 3D bubble statistics using 3D simulations of lab-scale (diameter 14.5cm) and pilot-scale bed (diameter 30cm) is presented and it is shown that the former (a) under-predicts sizes of larger bubbles, (b) cannot detect a large fraction of small bubbles (<3cm) and (c) is unable to track the azimuthal motion of bubbles in the larger bed. The scalability of the algorithm is discussed by comparing the computational cost of computing bubble statistics on highly resolved grids. Even though 3D bubble detection is significantly more expensive than 2D detection, the cost is still negligible compared to the cost of accurate simulations. Besides application to fluidization simulation data of large fluidized beds, this algorithm can be easily extended to characterize bubbles, droplets and clusters in other areas of multiphase flows.
•Indicators of the effectiveness of climate change adaptation are urgently required.•Conceptual, analytical and practical challenges exist in doing so.•A flexible framework for climate change ...adaptation indicators is proposed.•Further work required to support indicator development is identified.
Impacts of climate change on natural and human systems will become increasingly severe as the magnitude of climate change increases. Climate change adaptation interventions to address current and projected impacts are thus paramount. Yet, evidence on their effectiveness remains limited, highlighting the need for appropriate ecological indicators to measure progress of climate change adaptation for the natural environment. We outline conceptual, analytical, and practical challenges in developing such indicators, before proposing a framework with three process-based and two results-based indicator types to track progress in adapting to climate change. We emphasize the importance of dynamic assessment and modification over time, as new adaptation targets are set and/or as intervention actions are monitored and evaluated. Our framework and proposed indicators are flexible and widely applicable across species, habitats, and monitoring programmes, and could be accommodated within existing national or international frameworks to enable the evaluation of both large-scale policy instruments and local management interventions. We conclude by suggesting further work required to develop these indicators fully, and hope this will stimulate the use of ecological indicators to evaluate the effectiveness of policy interventions for the adaptation of the natural environment across the globe.
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