scholarly journals An unusual way to validate regional chemistry-transport models

2016 ◽  
Author(s):  
Lauren Menut ◽  
Sylvain Mailler ◽  
Bertrand Bessagnet ◽  
Guillaume Siour ◽  
Augustin Colette ◽  
...  
Keyword(s):  
Model Evaluation ◽  
Temporal Correlation ◽  
Spatial Location ◽  
Reference Period ◽  
Evaluation Technique ◽  
Transport Models ◽  
Time Periods ◽  
The Difference ◽  
Spatial Locations

Abstract. A simple and exhaustive model evaluation technique for regional chemistry-transport is discussed. It is based on the concept that we can learn more on models performances by comparing the results to in situ measurements available for other time periods than the period originally targeted in the simulation. First, the usual scores (spatial and temporal correlation) are computed for a reference period, using the actual temporal synchronization and spatial location of measurements . Second, the same scores are calculated for several other years by conserving only the actual spatial locations and days of the year. The difference between the two score provides complementary insights to the following questions: (i) is the model performing well only because the situation is persistent? (ii) is the model representative enough of the measurements for all variables? (iii) if the pollutants concentrations are not well modelled, is it due to meteorology or chemistry? In order to synthetize the large amount of results, a new score is proposed: the "multi-year variability", designed to compare the several indicators between all the years of validation and to quantify if the studied period was well modelled and, if yes, for the good reasons.

scholarly journals The 2015–2016 carbon cycle as seen from OCO-2 and the global in situ network

2019 ◽  
Vol 19 (15) ◽  
pp. 9797-9831 ◽  
Author(s):  
Sean Crowell ◽  
David Baker ◽  
Andrew Schuh ◽  
Sourish Basu ◽  
Andrew R. Jacobson ◽  
...  
Keyword(s):  
Carbon Cycle ◽  
Carbon Sink ◽  
Total Carbon ◽  
Transport Models ◽  
New Information ◽  
Global Coverage ◽  
The Difference ◽  
The Tropics

Abstract. The Orbiting Carbon Observatory-2 has been on orbit since 2014, and its global coverage holds the potential to reveal new information about the carbon cycle through the use of top-down atmospheric inversion methods combined with column average CO2 retrievals. We employ a large ensemble of atmospheric inversions utilizing different transport models, data assimilation techniques, and prior flux distributions in order to quantify the satellite-informed fluxes from OCO-2 Version 7r land observations and their uncertainties at continental scales. Additionally, we use in situ measurements to provide a baseline against which to compare the satellite-constrained results. We find that within the ensemble spread, in situ observations, and satellite retrievals constrain a similar global total carbon sink of 3.7±0.5 PgC yr−1, and 1.5±0.6 PgC yr−1 for global land, for the 2015–2016 annual mean. This agreement breaks down in smaller regions, and we discuss the differences between the experiments. Of particular interest is the difference between the different assimilation constraints in the tropics, with the largest differences occurring in tropical Africa, which could be an indication of the global perturbation from the 2015–2016 El Niño. Evaluation of posterior concentrations using TCCON and aircraft observations gives some limited insight into the quality of the different assimilation constraints, but the lack of such data in the tropics inhibits our ability to make strong conclusions there.

scholarly journals Spatial distribution ofSalmonella entericain poultry shed environments observed by intensive longitudinal environmental sampling

2019 ◽  
Author(s):  
Helen K Crabb ◽  
Joanne Lee Allen ◽  
Joanne Maree Devlin ◽  
Colin Reginald Wilks ◽  
James Rudkin Gilkerson
Keyword(s):  
Salmonella Enterica ◽  
Spatial Location ◽  
Epidemiological Studies ◽  
Epidemiological Surveillance ◽  
Environmental Sampling ◽  
Sample Collection ◽  
The North ◽  
Serovar Typhimurium ◽  
The Difference ◽  
Spatial Locations

ABSTRACTDuring a series of epidemiological studies to investigate the transmission of salmonellae within poultry environments, intensive longitudinal sampling within caged sheds revealed that both the number and location of sample collection within this environment were important to ensure the best chance of detectingSalmonellaspp. Multiple serovars ofSalmonella entericasubspeciesentericawere detected in each shed; 5% of all samples contained more than one serovar. Samples collected on the north side of the shed (OR = 1.77, 95% CI [1.17, 2.68]), on the sheltered side of the shed (OR = 1.90, 95% CI [1.26, 2.89]) and during winter (OR = 48.41, 95%CI [23.56, 104.19]) were more likely to be positive for salmonellae. The distribution of salmonellae within a shed was not homogenous, as differences were identified in the within-shed distribution ofSalmonella entericasubspeciesentericaserovar Typhimurium (χ2(27, 1,538) = 54.4, P < 0.001), andSalmonella entericasubspeciesentericaserovar Infantis (χ2(27, 1,538) = 79.8, P < 0.0001). The difference in sample prevalence by serovar and spatial location within a shed indicates that there are important shed micro-environmental factors that influence survival and/or distribution of salmonellae. These factors should be taken into consideration when undertaking environmental surveillance for salmonellae in flocks housed in caged sheds.IMPORTANCERoutine epidemiological surveillance for salmonellae in poultry relies initially on environmental sampling. Our study confirmed that the sampling methodology conducted within a poultry environment is a non-trivial part of sampling design. The spatial locations of sample collection within a shed revealed differences in both the sample prevalence and serovar of salmonellae detected.

scholarly journals The 2015–2016 Carbon Cycle As Seen from OCO-2 and the Global <i>In Situ</i> Network

2019 ◽  
Author(s):  
Sean Crowell ◽  
David Baker ◽  
Andrew Schuh ◽  
Sourish Basu ◽  
Andrew R. Jacobson ◽  
...  
Keyword(s):  
Carbon Cycle ◽  
Carbon Sink ◽  
Total Carbon ◽  
Transport Models ◽  
New Information ◽  
Global Coverage ◽  
The Difference ◽  
The Tropics

Abstract. The Orbiting Carbon Observatory-2 has been on orbit since 2014, and its global coverage holds the potential to reveal new information about the carbon cycle through the use of top-down atmospheric inversion methods combined with column average CO2 retrievals. We employ a large ensemble of atmospheric inversions utilizing different transport models, data assimilation techniques and prior flux distributions in order to quantify the satellite-informed fluxes from OCO-2 Version 7r land observations and their uncertainties at continental scales. Additionally, we use in situ measurements to provide a baseline against which to compare the satellite-constrained results. We find that within ensemble spread, in situ observations and satellite retrievals constrain a similar global total carbon sink of 3.7 ± 0.5 PgC, and 1.5 ± 0.6 PgC per year for global land, for the 2015–2016 annual mean. This agreement breaks down on smaller regions, and we discuss the differences between the experiments. Of particular interest is the difference between the different assimilation constraints in the tropics, with the largest differences occurring in tropical Africa, which could be an indication of the global perturbation from the 2015–2016 El Niño. Evaluation of posterior concentrations using TCCON and aircraft observations gives some limited insight into the quality of the different assimilation constraints, but the lack of such data in the tropics inhibits our ability to make strong conclusions there.

Dynamic Visual Noise Affects Visual Short-Term Memory for Surface Color, but not Spatial Location

2010 ◽  
Vol 57 (1) ◽  
pp. 17-26 ◽  
Author(s):  
Kevin Dent
Keyword(s):  
Short Term Memory ◽  
Spatial Location ◽  
Visual Noise ◽  
Dynamic Visual Noise ◽  
Short Term ◽  
Surface Color ◽  
Term Memory ◽  
Visual Short Term Memory ◽  
Experimental Tool ◽  
Spatial Locations

In two experiments participants retained a single color or a set of four spatial locations in memory. During a 5 s retention interval participants viewed either flickering dynamic visual noise or a static matrix pattern. In Experiment 1 memory was assessed using a recognition procedure, in which participants indicated if a particular test stimulus matched the memorized stimulus or not. In Experiment 2 participants attempted to either reproduce the locations or they picked the color from a whole range of possibilities. Both experiments revealed effects of dynamic visual noise (DVN) on memory for colors but not for locations. The implications of the results for theories of working memory and the methodological prospects for DVN as an experimental tool are discussed.

Comparison of Mammography and Ultrasonography for Tumor Size of DCIS of Breast Cancer

2019 ◽  
Vol 15 (2) ◽  
pp. 209-213
Author(s):  
Yu Wang ◽  
Jiantao Wang ◽  
Haiping Wang ◽  
Xinyu Yang ◽  
Liming Chang ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Correlation Coefficient ◽  
Tumor Size ◽  
Ductal Carcinoma ◽  
Pearson Correlation ◽  
Dense Breast ◽  
Pathological Examination ◽  
Negative Group ◽  
The Difference

Objective: Accurate assessment of breast tumor size preoperatively is important for the initial decision-making in surgical approach. Therefore, we aimed to compare efficacy of mammography and ultrasonography in ductal carcinoma in situ (DCIS) of breast cancer. Methods: Preoperative mammography and ultrasonography were performed on 104 women with DCIS of breast cancer. We compared the accuracy of each of the imaging modalities with pathological size by Pearson correlation. For each modality, it was considered concordant if the difference between imaging assessment and pathological measurement is less than 0.5cm. Results: At pathological examination tumor size ranged from 0.4cm to 7.2cm in largest diameter. For mammographically determined size versus pathological size, correlation coefficient of r was 0.786 and for ultrasonography it was 0.651. Grouped by breast composition, in almost entirely fatty and scattered areas of fibroglandular dense breast, correlation coefficient of r was 0.790 for mammography and 0.678 for ultrasonography; in heterogeneously dense and extremely dense breast, correlation coefficient of r was 0.770 for mammography and 0.548 for ultrasonography. In microcalcification positive group, coeffient of r was 0.772 for mammography and 0.570 for ultrasonography. In microcalcification negative group, coeffient of r was 0.806 for mammography and 0.783 for ultrasonography. Conclusion: Mammography was more accurate than ultrasonography in measuring the largest cancer diameter in DCIS of breast cancer. The correlation coefficient improved in the group of almost entirely fatty/ scattered areas of fibroglandular dense breast or in microcalcification negative group.

Dynamic network intelligent hybrid recommendation algorithm and its application in online shopping platform

2021 ◽  
pp. 1-13
Author(s):  
Yuxuan Gao ◽  
Haiming Liang ◽  
Bingzhen Sun
Keyword(s):  
Online Shopping ◽  
Rapid Development ◽  
Dynamic Network ◽  
Topsis Method ◽  
Recommendation Algorithm ◽  
Time Periods ◽  
The Difference ◽  
Relationship Of ◽  
Hybrid Recommendation ◽  
Novel Model

With the rapid development of e-commerce, whether network intelligent recommendation can attract customers has become a measure of customer retention on online shopping platforms. In the literature about network intelligent recommendation, there are few studies that consider the difference preference of customers in different time periods. This paper proposes the dynamic network intelligent hybrid recommendation algorithm distinguishing time periods (DIHR), it is a integrated novel model combined with the DEMATEL and TOPSIS method to solved the problem of network intelligent recommendation considering time periods. The proposed method makes use of the DEMATEL method for evaluating the preference relationship of customers for indexes of merchandises, and adopt the TOPSIS method combined with intuitionistic fuzzy number (IFN) for assessing and ranking the merchandises according to the indexes. We specifically introduce the calculation steps of the proposed method, and then calculate its application in the online shopping platform.

scholarly journals Comparison of In-Situ and Retrospective Self-Reports on Assessing Hearing Aid Outcomes

2020 ◽  
Author(s):  
Yu-Hsiang Wu ◽  
Elizabeth Stangl ◽  
Octav Chipara ◽  
Anna Gudjonsdottir ◽  
Jacob Oleson ◽  
...  
Keyword(s):  
Hearing Aids ◽  
Hearing Aid ◽  
Outcome Data ◽  
Self Report ◽  
Data Collection And Analysis ◽  
Self Reports ◽  
Outcome Difference ◽  
The Difference ◽  
Ecological Momentary

Abstract Background Ecological momentary assessment (EMA) is a methodology involving repeated surveys to collect in-situ self-reports that describe respondents' current or recent experiences. Audiology literature comparing in-situ and retrospective self-reports is scarce. Purpose To compare the sensitivity of in-situ and retrospective self-reports in detecting the outcome difference between hearing aid technologies, and to determine the association between in-situ and retrospective self-reports. Research Design An observational study. Study Sample Thirty-nine older adults with hearing loss. Data Collection and Analysis The study was part of a larger clinical trial that compared the outcomes of a prototype hearing aid (denoted as HA1) and a commercially available device (HA2). In each trial condition, participants wore hearing aids for 4 weeks. Outcomes were measured using EMA and retrospective questionnaires. To ensure that the outcome data could be directly compared, the Glasgow Hearing Aid Benefit Profile was administered as an in-situ self-report (denoted as EMA-GHABP) and as a retrospective questionnaire (retro-GHABP). Linear mixed models were used to determine if the EMA- and retro-GHABP could detect the outcome difference between HA1 and HA2. Correlation analyses were used to examine the association between EMA- and retro-GHABP. Results For the EMA-GHABP, HA2 had significantly higher (better) scores than HA1 in the GHABP subscales of benefit, residual disability, and satisfaction (p = 0.029–0.0015). In contrast, the difference in the retro-GHABP score between HA1 and HA2 was significant only in the satisfaction subscale (p = 0.0004). The correlations between the EMA- and retro-GHABP were significant in all subscales (p = 0.0004 to <0.0001). The strength of the association ranged from weak to moderate (r = 0.28–0.58). Finally, the exit interview indicated that 29 participants (74.4%) preferred HA2 over HA1. Conclusion The study suggests that in-situ self-reports collected using EMA could have a higher sensitivity than retrospective questionnaires. Therefore, EMA is worth considering in clinical trials that aim to compare the outcomes of different hearing aid technologies. The weak to moderate association between in-situ and retrospective self-reports suggests that these two types of measures assess different aspects of hearing aid outcomes.

scholarly journals Tuning Single-Molecule Conductance by Controlled Electric Field-Induced trans-to-cis Isomerisation

2021 ◽  
Vol 11 (8) ◽  
pp. 3317
Author(s):  
C.S. Quintans ◽  
Denis Andrienko ◽  
Katrin F. Domke ◽  
Daniel Aravena ◽  
Sangho Koo ◽  
...  
Keyword(s):  
Electric Field ◽  
Electric Fields ◽  
Single Molecule ◽  
Quantum Interference ◽  
Single Molecule Level ◽  
Wet Chemical Synthesis ◽  
Single Molecule Junctions ◽  
Tunnelling Microscopy ◽  
The Difference

External electric fields (EEFs) have proven to be very efficient in catalysing chemical reactions, even those inaccessible via wet-chemical synthesis. At the single-molecule level, oriented EEFs have been successfully used to promote in situ single-molecule reactions in the absence of chemical catalysts. Here, we elucidate the effect of an EEFs on the structure and conductance of a molecular junction. Employing scanning tunnelling microscopy break junction (STM-BJ) experiments, we form and electrically characterize single-molecule junctions of two tetramethyl carotene isomers. Two discrete conductance signatures show up more prominently at low and high applied voltages which are univocally ascribed to the trans and cis isomers of the carotenoid, respectively. The difference in conductance between both cis-/trans- isomers is in concordance with previous predictions considering π-quantum interference due to the presence of a single gauche defect in the trans isomer. Electronic structure calculations suggest that the electric field polarizes the molecule and mixes the excited states. The mixed states have a (spectroscopically) allowed transition and, therefore, can both promote the cis-isomerization of the molecule and participate in electron transport. Our work opens new routes for the in situ control of isomerisation reactions in single-molecule contacts.

scholarly journals Analyzing Satellite Ocean Color Match-Up Protocols Using the Satellite Validation Navy Tool (SAVANT) at MOBY and Two AERONET-OC Sites

2021 ◽  
Vol 13 (14) ◽  
pp. 2673
Author(s):  
Adam Lawson ◽  
Jennifer Bowers ◽  
Sherwin Ladner ◽  
Richard Crout ◽  
Christopher Wood ◽  
...  
Keyword(s):  
Infrared Imaging ◽  
Ocean Color ◽  
Visible Spectrum ◽  
Ground Truth ◽  
Naval Research ◽  
Satellite Validation ◽  
The Difference ◽  
Stability And Accuracy ◽  
Satellite Ocean Color

The satellite validation navy tool (SAVANT) was developed by the Naval Research Laboratory to help facilitate the assessment of the stability and accuracy of ocean color satellites, using numerous ground truth (in situ) platforms around the globe and support methods for match-up protocols. The effects of varying spatial constraints with permissive and strict protocols on match-up uncertainty are evaluated, in an attempt to establish an optimal satellite ocean color calibration and validation (cal/val) match-up protocol. This allows users to evaluate the accuracy of ocean color sensors compared to specific ground truth sites that provide continuous data. Various match-up constraints may be adjusted, allowing for varied evaluations of their effects on match-up data. The results include the following: (a) the difference between aerosol robotic network ocean color (AERONET-OC) and marine optical Buoy (MOBY) evaluations; (b) the differences across the visible spectrum for various water types; (c) spatial differences and the size of satellite area chosen for comparison; and (d) temporal differences in optically complex water. The match-up uncertainty analysis was performed using Suomi National Polar-orbiting Partnership (SNPP) Visible Infrared Imaging Radiometer Suite (VIIRS) SNPP data at the AERONET-OC sites and the MOBY site. It was found that the more permissive constraint sets allow for a higher number of match-ups and a more comprehensive representation of the conditions, while the restrictive constraints provide better statistical match-ups between in situ and satellite sensors.

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