Nonstationary spatiotemporal Bayesian data fusion for pollutants in the near‐road environment

Concentrations of near‐road air pollutants (NRAPs) have increased to very high levels in many urban centers around the world, particularly in developing countries. The adverse health effects of exposure to NRAPs are greater when the exposure occurs in the near‐road environment as compared to background levels of pollutant concentration. Therefore, there is increasing interest in monitoring pollutant concentrations in the near‐road environment. However, due to various practical limitations, monitoring pollutant concentrations near roadways and traffic sources is generally rather difficult and expensive. As an alternative, various deterministic computer models that provide predictions of pollutant concentrations in the near‐road environment, such as the research line‐source dispersion model (RLINE), have been developed. A common feature of these models is that their outputs typically display systematic biases and need to be calibrated in space and time using observed pollutant data. In this paper, we present a nonstationary Bayesian data fusion model that uses a novel data set on monitored pollutant concentrations (nitrogen oxides or NOx and fine particulate matter or PM2.5) in the near‐road environment and, combining it with the RLINE model output, provides predictions at unsampled locations. The model can also be used to evaluate whether including the RLINE model output leads to improved pollutant concentration predictions and whether the RLINE model output captures the spatial dependence structure of NRAP concentrations in the near‐road environment. A defining characteristic of the proposed model is that we model the nonstationarity in the pollutant concentrations by using a recently developed approach that includes covariates, postulated to be the driving force behind the nonstationary behavior, in the covariance function.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/151876/1/env2581.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/151876/2/env2581_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/151876/3/ENV_2581-Supp-0001-BDF_supp_material.pd

Further investigation of confirmed urinary tract infection (UTI) in children under five years: a systematic review.

Background: Further investigation of confirmed UTI in children aims to prevent renal scarring and future complications. Methods: We conducted a systematic review to determine the most effective approach to the further investigation of confirmed urinary tract infection (UTI) in children under five years of age. Results: 73 studies were included. Many studies had methodological limitations or were poorly reported. Effectiveness of further investigations: One study found that routine imaging did not lead to a reduction in recurrent UTIs or renal scarring. Diagnostic accuracy: The studies do not support the use of less invasive tests such as ultrasound as an alternative to renal scintigraphy, either to rule out infection of the upper urinary tract (LR- = 0.57, 95%CI: 0.47, 0.68) and thus to exclude patients from further investigation or to detect renal scarring (LR+ = 3.5, 95% CI: 2.5, 4.8). None of the tests investigated can accurately predict the development of renal scarring. The available evidence supports the consideration of contrast-enhanced ultrasound techniques for detecting vesico-ureteric reflux (VUR), as an alternative to micturating cystourethrography (MCUG) (LR+ = 14.1, 95% CI: 9.5, 20.8; LR- = 0.20, 95%CI: 0.13, 0.29); these techniques have the advantage of not requiring exposure to ionising radiation. Conclusion: There is no evidence to support the clinical effectiveness of routine investigation of children with confirmed UTI. Primary research on the effectiveness, in terms of improved patient outcome, of testing at all stages in the investigation of confirmed urinary tract infection is urgently required

Determination of the optical depth of a DI diesel spray

The optical depth is responsible of limiting the optical diagnostic using visible wavelength in the sprays. This paper proposes to measure the optical depth directly in a real Diesel spray through line-of-sight laser extinction measurements. This easily reproducible method which does not require expensive or complex optical techniques is detailed and the measurement procedure is presented in this paper. As diesel sprays are mostly optically thick, the measurements in the denser region are not reliable and a fuel concentration model has been used to derive the results to the entire spray. This work provides values of SMD at different distance from the nozzle tip depending on the specific parameters like injection pressure or discharge density. The values extracted from a combined experimental/computational approach have been compared to PDPA measurements under the same testing conditions. The results have shown that the maximum optical depth was higher than 10 and that an increase of the injection pressure led to higher ¿ values. The SMD values appeared to be below the results measured by the PDPA and the droplet diameter showed to be the main responsible of the optical depth of the jet under the tested conditions. © 2011 The Korean Society of Mechanical Engineers and Springer-Verlag Berlin Heidelberg.Payri González, F.; Pastor, JV.; Payri, R.; Manin, JL. (2011). Determination of the optical depth of a DI diesel spray. Journal of Mechanical Science and Technology. 25(1):209-219. https://doi.org/10.1007/s12206-010-1024-xS209219251L. Pickett and D. Siebers, Non-sooting, low flame temperature mixing-controlled DI diesel combustion, SAE Paper, 2004-01-1399 (2004).S. Cheng, A. Upatnieks and C. J. Mueller, Investigation of fuel effects on dilute, mixing-controlled combustion in an optical direct-injection diesel engine, Energy & Fuels, 21 (2007) 1989–2002.S. Park, H. Kim and B. Choi, Emission characteristics of exhaust gases and nanoparticles from a diesel engine with biodiesel-diesel blended fuel (BD20), J. Mech. Sci. Technol., 23(9) (2009) 2555–2564.J. Benajes, S. Molina, K. De Rudder and T. Rente, Influence of injection rate shaping on combustion and emissions for a medium duty diesel engine, J. Mech. Sci. Technol., 20(9) (2006) 1436–1448.S. Som, S. K. Aggarwal, E. M. El-Hannouny, D. E. Longman, Investigation of Nozzle Flow and Cavitation Characteristics in a Diesel Injector, J. of Eng. Gas Turb. and Power, 132(4) (2010).J. Lee and K. Min, Effects of needle response on spray characteristics in high pressure injector driven by piezo actuator for common-rail injection system, J. Mech. Sci. Technol., 19(5) (2005) 1194–1205.R. Payri, F. J. Salvador, J. Gimeno and V. Soare, Determination of diesel sprays characteristics in real engine in-cylinder air density and pressure conditions, J. Mech. Sci. Technol., 19 (2005) 2040–2052.Y. Yue, C. F. Powell, R. Poola and J. Wang, Quantitative measurements of diesel fuel spray characteristics in the near-nozzle region by using x-ray absorption, Atomization Sprays, 11(4) (2001).M. Linne, M. Paciaroni, T. Hall and T. Parker, Ballistic imaging of the near field in a diesel spray, Experiments in Fluid,s 40(6) (2006) 836–846.H. E. Albrecht, N. Damaschke, M. Borys and C. Tropea, Laser Doppler and Phase Doppler Measurement Techniques, Springer Berlin (2003).R. Domann and Y. Hardalupas, Quantitative Measurement of planar Droplet Sauter Mean Diameter in sprays using Planar Droplet Sizing, 11th Int. Symp. on App. of Laser Techniques to Fluid Mechanics (Lisbon Portugal) (2002).M. Van der Mark, M. Van Albada and A. Lagendijk, Light scattering in strongly scattering media: Multiple scattering and weak localization, Physical Review, B 37(7) (1988).L. Araneo and R. Payri, Experimental quantification of the planar droplet sizing technique error for micro-metric monodispersed spherical particles, Proc. of the Inst. for Liquid Atomization and Spray Systems Conf. (Como Italy) (2008).G. Hiromi, Multiple scattering correction in the measurement of particle size and number density by the diffraction method, Applied Optics 25(19) (1986) 3552–3558.C. Dumouchel, P. Yongyingsakthavorn and J. Cousin, Light multiple scattering correction of laser-diffraction spray drop-size distribution measurements, International Journal of Multiphase Flow 35(3) (2009) 277–287.J. V. Pastor, R. Payri, L. Araneo and J. Manin, Correction method for droplet sizing by laser-induced fluorescence in a controlled test situation, Optical Engineering, 48(1) (2009).C. Espey and J. E. Dec, The effect of TDC temperature and density on the liquid-phase fuel penetration in a Di Diesel engine, SAE transactions, 104(4) (1995) 1400–1414.J. M. Desantes, R. Payri, A. García and J. Manin, Experimental Study of Biodiesel Blends’ Effects on Diesel Injection Processes, Energy & Fuels, 23 (2009) 3227–3235.C. R. Kitchin, Stars, Nebulae and the Interstellar Medium: Observational Physics and Astrophysics CRC Press (1987).M. A. Linne, Spectroscopic Measurement: An Introduction to the Fundamentals, Academic Press (London, UK) (2002).J. V. Pastor, J. J. Lopez, J. E. Juliá and J. V. Benajes, Planar laser-induced fluorescence fuel concentration measurements in isothermal sprays, Opt. Express, 10(7) (2002) 309–323.J. Benajes, R. Payri, S. Molina, A.H. Plazas, Investigation of the influence of injection rate shaping on the spray characteristics in a diesel common rail system equipped with a piston amplifier, Journal of fluids engineering-transactions of the ASME, 127(6) (2005) 1102–1110.V. Bermudez, R. Payri, F. J. Salvador and A. H. Plazas, Study of the influence of nozzle seat type on injection rate and spray behavior, ImechE, Journal of automobile engineering, Part D, 219 (2005) 677–689.R. Payri, J. M. Garcia, F. J. Salvador and J. Gimeno, Using spray momentum flux measurements to understand the influence of diesel nozzle geometry on spray characteristics, Fuel, 84 (2005) 551–561.J. M. Desantes, R. Payri, F. J. Salvador and A. Gil, Development and validation of a theoretical model for diesel spray penetration, Fuel, 85 (2006) 910–917.H. Hattori, K. Narumiya, M. Tsue and T. Kadota, Analysis of initial breakup mechanism of diesel spray injected into high-pressure ambience, SAE Paper, 2004-01-0528 (2004).J. D. J. Ingle and S. R. Crouch, Spectrochemical Analysis, Prentice Hall (New Jersey, USA) (1988).F. V. Tinaut, A. Melgar, F. Castro, M. L. Sanchez and B. A. Gimenez, Method to determine liquid concentration in nonstationary axisymmetric sprays, Experiments in Fluids, 23 (1997) 299–305.P. Laven, Simulation of Rainbows, Coronas and Glories by the use of Mie theory, Applied Optics 43(3) (2003) 436–444.J. M. Desantes, R. Payri, J. M. Garcia and F. J. Salvador, A contribution to the understanding of isothermal diesel spray dynamics, Fuel, 86(7–8) (2007) 1093–1101.R. Payri, L. Araneo, J. Shakal and V. Soare, Phase doppler measurements: system set-up optimization for characterization of a diesel nozzle, J. Mech. Sci. Technol., 22 (2008) 1620–1632.E. Berrocal, D. L. Sedarsky, M. E. Paciaroni, I. V. Meglinski and M. A. Linne, Laser light scattering in turbid media Part I: Experimental and simulated results for the spatial intensity distribution, Optics Express, 15 (2007) 10649–10665.C. Roze, T. Girasole, L. Mevcs, G. Grehan, L. Hespel and A. Delfour, Interaction between ultra short pulses and a dense scattering medium by Monte Carlo simulation: consideration of particle size effect, Optics Communications, 220(4–6) (2003) 237–245.E. Berrocal, D. L. Sedarsky, M. E. Paciaroni, I. 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Assessing the value of seasonal climate forecasts for decision‐making

Seasonal climate forecasts (SCF) can support decision‐making and thus help society cope with and prepare for climate variability and change. The demand for understanding the value and benefits of using SCF in decision‐making processes can be associated with different logics. Two of these would be the need to justify public and private investment in the provision of SCF and demonstrating the gains and benefits of using SCF in specific decision‐making contexts. This paper reviews the main factors influencing how SCF is (or can be) valued in supporting decision‐making and the main methods and metrics currently used to perform such valuations. Our review results in four key findings: (a) there is a current emphasis on economic ex ante studies and the quantification of SCF value; (b) there are fundamental differences in how the value of SCF is defined and estimated across methods and approaches; (c) most valuation methods are unable to capture the differential benefits and risks of using SCF across spatiotemporal scales and groups; and (d) there is limited involvement of the decision‐makers in the valuation process. The paper concludes by providing some guiding principles towards more effective valuations of SCF, notably the need for a wider diversity and integration of methodological approaches. These should particularly embrace ex‐post, qualitative, and participatory approaches which allow co‐evaluation with decision‐makers so that more comprehensive and equitable SCF valuations can be developed in future

How does study quality affect the results of a diagnostic meta-analysis?

Background: The use of systematic literature review to inform evidence based practice in diagnostics is rapidly expanding. Although the primary diagnostic literature is extensive, studies are often of low methodological quality or poorly reported. There has been no rigorously evaluated, evidence based tool to assess the methodological quality of diagnostic studies. The primary objective of this study was to determine the extent to which variations in the quality of primary studies impact the results of a diagnostic meta-analysis and whether this differs with diagnostic test type. A secondary objective was to contribute to the evaluation of QUADAS, an evidence-based tool for the assessment of quality in diagnostic accuracy studies. Methods: This study was conducted as part of large systematic review of tests used in the diagnosis and further investigation of urinary tract infection (UTI) in children. All studies included in this review were assessed using QUADAS, an evidence-based tool for the assessment of quality in systematic reviews of diagnostic accuracy studies. The impact of individual components of QUADAS on a summary measure of diagnostic accuracy was investigated using regression analysis. The review divided the diagnosis and further investigation of UTI into the following three clinical stages: diagnosis of UTI, localisation of infection, and further investigation of the UTI. Each stage used different types of diagnostic test, which were considered to involve different quality concerns. Results: Many of the studies included in our review were poorly reported. The proportion of QUADAS items fulfilled was similar for studies in different sections of the review. However, as might be expected, the individual items fulfilled differed between the three clinical stages. Regression analysis found that different items showed a strong association with test performance for the different tests evaluated. These differences were observed both within and between the three clinical stages assessed by the review. The results of regression analyses were also affected by whether or not a weighting (by sample size) was applied. Our analysis was severely limited by the completeness of reporting and the differences between the index tests evaluated and the reference standards used to confirm diagnoses in the primary studies. Few tests were evaluated by sufficient studies to allow meaningful use of meta-analytic pooling and investigation of heterogeneity. This meant that further analysis to investigate heterogeneity could only be undertaken using a subset of studies, and that the findings are open to various interpretations. Conclusion: Further work is needed to investigate the influence of methodological quality on the results of diagnostic meta-analyses. Large data sets of well-reported primary studies are needed to address this question. Without significant improvements in the completeness of reporting of primary studies, progress in this area will be limited

Validation of Calprotectin As a Novel Biomarker For The Diagnosis of Pleural Effusion: a Multicentre Trial

Discriminating between malignant pleural effusion (MPE) and benign pleural effusion (BPE) remains difficult. Thus, novel and efficient biomarkers are required for the diagnosis of pleural effusion (PE). The aim of this study was to validate calprotectin as a diagnostic biomarker of PE in clinical settings. A total of 425 patients were recruited, and the pleural fluid samples collected had BPE in 223 cases (53.7%) or MPE in 137 patients (33%). The samples were all analysed following the same previously validated clinical laboratory protocols and methodology. Calprotectin levels ranged from 772.48 to 3,163.8 ng/mL (median: 1,939 ng/mL) in MPE, and 3,216-24,000 ng/mL in BPE (median: 9,209 ng/mL; p < 0.01), with an area under the curve of 0.848 [95% CI: 0.810-0.886]. For a cut-off value of </= 6,233.2 ng/mL, we found 96% sensitivity and 60% specificity, with a negative and positive predictive value, and negative and positive likelihood ratios of 96%, 57%, 0.06, and 2.4, respectively. Multivariate analysis showed that low calprotectin levels was a better discriminator of PE than any other variable [OR 28.76 (p < 0.0001)]. Our results confirm that calprotectin is a new and useful diagnostic biomarker in patients with PE of uncertain aetiology which has potential applications in clinical practice because it may be a good complement to cytological methods

Calibrating ensemble reliability whilst preserving spatial structure

Ensemble forecasts aim to improve decision-making by predicting a set of possible outcomes. Ideally, these would provide probabilities which are both sharp and reliable. In practice, the models, data assimilation and ensemble perturbation systems are all imperfect, leading to deficiencies in the predicted probabilities. This paper presents an ensemble post-processing scheme which directly targets local reliability, calibrating both climatology and ensemble dispersion in one coherent operation. It makes minimal assumptions about the underlying statistical distributions, aiming to extract as much information as possible from the original dynamic forecasts and support statistically awkward variables such as precipitation. The output is a set of ensemble members preserving the spatial, temporal and inter-variable structure from the raw forecasts, which should be beneficial to downstream applications such as hydrological models. The calibration is tested on three leading 15-d ensemble systems, and their aggregation into a simple multimodel ensemble. Results are presented for 12 h, 1° scale over Europe for a range of surface variables, including precipitation. The scheme is very effective at removing unreliability from the raw forecasts, whilst generally preserving or improving statistical resolution. In most cases, these benefits extend to the rarest events at each location within the 2-yr verification period. The reliability and resolution are generally equivalent or superior to those achieved using a Local Quantile-Quantile Transform, an established calibration method which generalises bias correction. The value of preserving spatial structure is demonstrated by the fact that 3×3 averages derived from grid-scale precipitation calibration perform almost as well as direct calibration at 3×3 scale, and much better than a similar test neglecting the spatial relationships. Some remaining issues are discussed regarding the finite size of the output ensemble, variables such as sea-level pressure which are very reliable to start with, and the best way to handle derived variables such as dewpoint depression

Efectos de partos ocurridos alrededor del inicio de la época lluviosa sobre indicadores de eficiencia. I. Producción de leche

The objective of this study was to evaluate seasonal calving effect on milk production at the beginning of the rainy season in Camagüey province. Commercial dairy herds were assessed during four periods with 68 % of annual seasonal calvings. Each period comprised five months, i. e., March-July, April-August, May-September, and JuneOctober. Variables measured were milk production per dairy cow, milk production per work unit, milk production per hectare, and annual total milk production. The statistical method used was a covariance analysis. The best seasonal calving period was April-August (P &lt; 0,05) with the higher scores for the studied variables: milk production per dairy cow (4,5 ± 0,14 kg), milk production per hectare (1 281 ± 15,8 kg), milk production per work unit (33 383 ± 11 kg), and annual total milk production (139 417 ± 291 kg). Therefore, efficiency of dairy stock systems improves during the April-August period. Further studies on beef production under different environmental conditions are recommended.Con el objetivo de evaluar el efecto del período de los partos ocurridos alrededor del inicio del período lluvioso, sobre la producción de leche de rebaños comerciales en Camagüey, Cuba, se estudiaron cuatro períodos de cinco meses cada uno (marzo-julio, abril-agosto, mayo-septiembre y junio-octubre) con más de un 68 % de los partos del año. Se midieron las variables: producción de leche por vaca, unidad de trabajo, hectárea y total. Como método estadístico se utilizó un análisis de covarianza y se determinó que el mejor período de ocurrencia de los partos fue abrilagosto (P &lt; 0,05), con los mejores resultados en producción de leche por vaca (4,5 ± 0,14 kg), hectárea (1 281 ± 15,8 kg), unidad de trabajo (33 383 ± 11 kg) y el total anual (139 417 ± 291 kg). Se concluye que en el período abril-agosto mejora la eficiencia de los sistemas vacunos lecheros, por lo que se recomienda extender el estudio hacia otras condiciones ambientales de producción vacuna