Large Relative Differences Research Articles

Meso-scale environmental heterogeneity drives plant trait distributions in fragmented dry grasslands

Environmental heterogeneity shapes the patterns of resources and limiting factors and therefore can be an important driver of plant community composition through the selection of the most adaptive functional traits. In this study, we explored plant trait–environment relationships in environmentally heterogeneous microsite complexes at the meso-scale (few meters), and used ancient Bulgarian and Hungarian burial mounds covered by dry grasslands as a model habitat. We assessed within-site trait variability typical of certain microsites with different combinations of environmental parameters (mound slopes with different aspects, mound tops, and surrounding plain grasslands) using a dataset of 480 vegetation plots. For this we calculated community-weighted means (CWMs) and abundance models. We found that despite their small size, the vegetation on mounds was characterized by different sets of functional traits (higher canopy, higher level of clonality, and heavier seeds) compared to the plain grasslands. North-facing slopes with mild environmental conditions were characterized by perennial species with light seeds, short flowering period, and a high proportion of dwarf shrubs sharply contrasted from the plain grasslands and from the south-facing slopes and mound tops with harsh environmental conditions. Patterns predicted by CWMs and abundance models differed in the case of certain traits (perenniality, canopy height, and leaf dry matter content), suggesting that environmental factors do not necessarily affect trait optima directly, but influence them indirectly through correlating traits. Due to the large relative differences in environmental parameters, contrasts in trait composition among microsites were mostly consistent and independent from the macroclimate. Mounds with high environmental heterogeneity can considerably increase variability in plant functional traits and ecological strategies at the site and landscape levels. The large trait variation on topographically heterogeneous landscape features can increase community resilience against climate change or stochastic disturbances, which underlines their conservation importance.

Intercomparison of aerosol optical depths from four reanalyses and their multi-reanalysis consensus

Abstract. The emergence of aerosol reanalyses in recent years has facilitated a comprehensive and systematic evaluation of aerosol optical depth (AOD) trends and attribution over multi-decadal timescales. Notable multi-year aerosol reanalyses currently available include NAAPS-RA from the US Naval Research Laboratory, the NASA MERRA-2, JRAero from the Japan Meteorological Agency (JMA), and CAMSRA from Copernicus/ECMWF. These aerosol reanalyses are based on differing underlying meteorology models, representations of aerosol processes, as well as data assimilation methods and treatment of AOD observations. This study presents the basic verification characteristics of these four reanalyses versus both AERONET and MODIS retrievals in monthly AOD properties and identifies the strength of each reanalysis and the regions where divergence and challenges are prominent. Regions with high pollution and often mixed fine-mode and coarse-mode aerosol environments, such as South Asia, East Asia, Southeast Asia, and the Maritime Continent, pose significant challenges, as indicated by higher monthly AOD root mean square error. Moreover, regions that are distant from major aerosol source areas, including the polar regions and remote oceans, exhibit large relative differences in speciated AODs and fine-mode versus coarse-mode AODs among the four reanalyses. To ensure consistency across the globe, a multi-reanalysis consensus (MRC, i.e., ensemble mean) approach was developed similarly to the International Cooperative for Aerosol Prediction Multi-Model Ensemble (ICAP-MME). Like the ICAP-MME, while the MRC does not consistently rank first among the reanalyses for individual regions, it performs well by ranking first or second globally in AOD correlation and RMSE, making it a suitable candidate for climate studies that require robust and consistent assessments.

A single centre intercomparison between commercial treatment planning systems for 90Y radioembolization using virtual and experimental phantoms

IntroductionDedicated Treatment Planning Systems (TPSs) were developed to personalize 90Y-transarterial radioembolization. This study evaluated the agreement among four commercial TPSs assessing volumes of interest (VOIs) volumes and dose metrics. MethodsA homogeneous (EH) and an anthropomorphic phantom with hot and cold inserts (EA) filled with 99mTc-pertechnetate were acquired with a SPECT/CT scanner. Their virtual versions (VH and VA, respectively) and a phantom with activity inside a single voxel (VK) were generated by an in-house MATLAB script. Images and delineated VOIs were imported into the TPSs to compute voxel-based absorbed dose distributions with various dose deposition approaches: local deposition method (LDM) and dose kernel convolution (DKC) with/without local density correction (LDC). VOI volumes and mean absorbed doses were assessed against their median value across TPSs. Dose-volume histograms (DVHs) and VK-derived dose profiles were evaluated. ResultsSmall (<2.1 %) and large (up to 42.4 %) relative volume differences were observed on large (>500 ml) and small VOIs, respectively. Mean absorbed doses relative differences were < 3 % except for small VOIs with steep dose gradients (up to 89.1 % in the VA Cold Sphere VOI). Within the same TPS, LDC negligibly affected the mean absorbed dose, while DKC and LDM showed differences up to 63 %. DHVs were mostly overlapped in experimental phantoms, with some differences in the virtual versions. Dose profiles agreed within 1 %. ConclusionTPSs showed an overall good agreement except for small VOI volumes and mean absorbed doses of VOIs with steep dose gradients. These discrepancies should be considered in the dosimetry uncertainty assessment, thus requiring an appropriate harmonization.

Changes in Socioeconomic Disparities for Traffic-Related Air Pollution Exposure During Pregnancy Over a 20-Year Period in Texas

Air pollution presents clear environmental justice issues. However, few studies have specifically examined traffic-related air pollution (TRAP), a source driven by historically racist infrastructure policies, among pregnant individuals, a population susceptible to air pollution effects. How these disparities have changed over time is also unclear but has important policy implications. To examine changes in TRAP exposure by sociodemographic characteristics among recorded pregnancies over a 20-year period. This population-based birth cohort study used descriptive analysis among pregnant individuals in Texas from 1996 to 2016. All pregnant individuals with valid residential address, socioeconomic, and demographic data were included. Individual-level race and ethnicity, education, and maternal birthplace data were extracted from birth certificates and neighborhood-level household income and historical neighborhood disinvestment (ie, redlining) data were assessed via residential addresses. Data analysis occurred between June 2022 and June 2023. The main outcome, TRAP exposure at residential addresses, was assessed via traffic levels, represented by total and truck-specific vehicle miles traveled (VMT) within 500 m; nitrogen dioxide (no2) concentrations from a spatial-temporal land use regression model (ie, vehicle tailpipe emissions); and National Air Toxic Agency cancer risk index from on-road vehicle emissions. TRAP exposure differences were assessed by sociodemographic indicators over the 1996 to 2016 period. Among 7 043 598 pregnant people (mean [SD] maternal age, 26.8 [6.1] years) in Texas from 1996 to 2016, 48% identified as Hispanic or Latinx, 4% identified as non-Hispanic Asian or Pacific Islander, 12% identified as non-Hispanic Black, and 36% identified as non-Hispanic White. There were differences in TRAP for pregnant people by all sociodemographic variables examined. The absolute level of these disparities decreased from 1996 to 2016, but the relative level of these disparities increased: for example, in 1996, non-Hispanic Black pregnant individuals were exposed to a mean (SD) 15.3 (4.1) ppb of no2 vs 13.5 (4.4) ppb of no2 for non-Hispanic White pregnant individuals, compared with 2016 levels of 6.7 (2.4) ppb no2 for Black pregnant individuals and 5.2 (2.4) ppb of no2 for White pregnant individuals. Large absolute and relative differences in traffic levels were observed for all sociodemographic characteristics, increasing over time. For example, non-Hispanic Black pregnant individuals were exposed to a mean (SD) of 22 836 (32 844) VMT within 500 m of their homes, compared with 12 478 (22 870) VMT within 500 m of the homes of non-Hispanic White pregnant individuals in 2016, a difference of 83%. This birth cohort study found that while levels of air pollution disparities decreased in absolute terms over the 20 years of the study, relative disparities persisted and large differences in traffic levels remained, requiring renewed policy attention.

Gypsum-Based Humidity-Control Material: Preparation, Performance and Its Impact on Building Energy Consumption.

This paper introduces a new type of gypsum-based humidity-control material. The material combines gypsum-silica gel humidity-control material with 20% sepiolite powder activated by calcium chloride. Both experimental and simulation studies were conducted to assess its humidity-control performance. The experimental results indicate that gypsum-based humidity-control material has the property of absorbing moisture in high-humidity environments and releasing moisture in low-humidity environments. Moreover, both environmental temperature and relative humidity (RH) have an impact on the material's humidity-control performance. At a relative humidity of 97.4%, the maximum equilibrium moisture content of the material is 0.225 g/g, which is 1.4 times that of the gypsum-silica gel humidity-control material and 4.5 times that of pure gypsum material. The simulation results indicate that gypsum-based humidity-control material effectively mitigates indoor relative humidity fluctuations and maintains indoor air relative humidity within a narrow range. Furthermore, the material has the potential to reduce building energy consumption. This is especially evident under climate conditions with large temperature and relative humidity differences between day and night, such as in Beijing, Paris, and Atlanta. The maximum potential energy-saving rate in Beijing can reach up to 19.31%.

Low-dissipation engines: Microscopic construction via shortcuts to adiabaticity and isothermality, the optimal relation between power and efficiency.

We construct a microscopic model of low-dissipation engines by driving a Brownian particle in a time-dependent harmonic potential. Shortcuts to adiabaticity and shortcuts to isothermality are introduced to realize the adiabatic and isothermal branches in a thermodynamic cycle, respectively. We derive an analytical formula of the efficiency at maximum power with explicit expressions of dissipation coefficients under the optimized protocols. When the relative temperature difference between the two baths in the cycle is insignificant, this expression satisfies the universal law of efficiency at maximum power up to the quadratic term of the Carnot efficiency. For large relative temperature differences, the efficiency at maximum power tends to be 1/2. Furthermore, we analyze the issue of power at any given efficiency for general low-dissipation engines and then obtain the supremum of the power in three limiting cases, respectively. These expressions of maximum power at given efficiency provide the optimal relations between power and efficiency which are tighter than the results in previous references.

The effects of modified operation on emissions from a pellet-fed, forced-draft gasifier stove

Traditional solid fuel cookstoves emit gas- and particle-phase pollutants that contribute to household air pollution, human disease, and climate impacts. Forced-draft semi-gasifier stoves are an attractive intermediate step to zero-emitting stoves due to their reported lower emissions in laboratory and field studies, and potential for increased availability in more rural locales. However, emissions from these stoves have been shown to be highly variable and sensitive to stove design, fuel type, secondary air velocity, and operation mode. We measured carbon monoxide (CO), particulate matter (PM2.5), organic and elemental carbon, and particle number (15–685 nm) emissions of the widely adopted Mimi Moto pellet-fed, gasifier stove for different operating conditions under two modified protocols, the Water Boiling Test (WBT) and an updated laboratory testing protocol ISO 19867-1 (ISO). We categorized operating conditions into three approaches: Startup (varying ignition material), Shutdown (varying fan speed during a 45-min burnout period), and Refuel (varying the height of charred pellets added for re-ignition). Refueling led to the largest and most variable emissions, but lab emissions were all lower than high field emissions (e.g., similar to those of traditional solid fuels) and remained primarily in ISO Tiers 5 and 4 for CO and PM2.5, aspirational and second-best, respectively. We find large relative differences in emissions when comparing our results to similar studies conducted with the Mimi Moto and ISO protocol, suggesting small operational differences can have large emissions implications. To minimize emissions, we recommend using kerosene for ignition, turning the fan off when pellets are done burning and flame has extinguished, and reigniting with fresh pellets instead of pellet char. Improved training and maintenance are needed in real-world applications to decrease the frequency of high-emission events. Tightly constrained testing and detection limits remain challenges to fully understanding factors contributing to these events.

Atmospheric simulation‐based precipitation datasets outperform satellite‐based products in closing basin‐wide water budget in the eastern Tibetan Plateau

AbstractSatellite‐based precipitation products (SBPs) have been widely used in hydrological applications in recent decades but may contain large uncertainties in mountainous regions. Atmospheric simulation‐based datasets (ABDs) have been greatly improved in recent years, but their applications in mountainous hydrology are rare and need further validation. This study compares the performance of three SBPs and two ABDs in the mountainous Minjiang River basin, focusing on their potential for closing the basin‐wide water budget. The three SBPs include the China Merged Precipitation Analysis (CMPA), the Integrated Multi‐satellitE Retrievals for Global Precipitation Measurement (IMERG) and the Global Satellite Mapping of Precipitation (GSMaP); the two ABDs are the fifth generation Reanalysis product of the European Centre for Medium Range Weather Forecasts (ERA5) and the High Asia Refined Analysis Version 2 (HAR V2). The five products are validated with rain gauge data and results show that all the five products except IMERG can generally reproduce the spatial pattern and elevation dependence of observed precipitation. Particularly, precipitation amount in the two ABDs is close to gauge observations in the low elevations, but much more than the gauge observations in areas with a sharp rise in elevations. Assessment of water budget shows that all SBPs yield severe negative water imbalance (greater than 50.0% of corresponding runoff) at most sub‐basins, while the ABDs can better close the water budget with water imbalance values between ±30.0% in most sub‐basins, respectively. Further analyses show that large relative differences between SBPs and ABDs mainly occur in areas with large topographical relief and in winter, which is likely because the ABDs outperform the SBPs in capturing orographic precipitation in complex terrain and solid precipitation in winter.

A comprehensive study on the coupled multi-mode vibrations of cylindrical shells

As is discussed in the previous work (Dong et al. 2021), the functions of beam-like modes are not suitable for simulating the cylindrical shells with the clamped and free ends. Also, ignoring the influences of the in-plane inertias can lead to large relative differences of the solutions of vibration characteristics. This work aims to accurately calculate the vibration characteristics of the cylindrical shells under various classical boundary conditions comprised of movable simply-supported, immovable simply-supported, sliding, clamped and free ends. Meanwhile, this work deals with the nonlinear coupled multi-mode vibrations of the cylindrical shell under different boundary conditions with the in-plane inertias taken into consideration. Firstly, several modified Chebyshev polynomials in terms of the axial coordinate and new harmonic functions in terms of the circumferential coordinate are employed to establish the equations of natural frequency in the frame of Lagrange equations for all the single-modes, where the polynomials are independent of geometries and material properties of the shells. And then, the circumferential-wave-dependent mode functions of the cylindrical shells are proposed, based on these mode functions coming from the linear vibration, a unified nonlinear differential equation of motion of the cylindrical shells under different boundary conditions is established for the first endeavor, in which the coupled multi-mode vibrations containing various vibration waves are considered. Finally, the high dimensional differential equation with the square and cubic nonlinearities is investigated by employing the incremental harmonic balance method. Results shown that polynomials accurately satisfy various boundary conditions, and the contribution of the single-mode to the coupled multi-mode vibration is related to the loading patterns.

Critical examination on in-plane inertias for vibration characteristics of cylindrical shells

There has been a common assumption that neglects the in-plane inertia or rotary inertia of a cylindrical shell to yield analytical and numerical solutions of the vibration characteristics. This assumption can largely simplify some derivation processes and result in a unified governing equation, nevertheless, precondition and justification of this assumption have not been examined yet. Presented herein is a critical examination on the in-plane inertia and rotary inertia for breathing vibration of the cylindrical shell. Analytical solutions are presented based on Donnell’s shell theory and the first-order shear deformation theory, respectively, in which simply-supported, clamped and free ends of the cylindrical shell are considered. Finite-element analyses about breathing modes and vibration characteristics are conducted to confirm the validity of present solutions. Furthermore, the mechanisms of some phenomenons are interpreted. It is shown herein that the influences of ignoring the in-plane and rotary inertias on natural frequencies of the cylindrical shell depend on the breathing modes, principally by the number of waves in the circumferential direction of the breathing modes. The in-plane inertia along the axial direction has a very limited effect on natural frequencies compared with those along the radial and circumferential directions. There are large relative differences by using the functions of beam-like modes to calculate the vibration characteristics of the cylindrical shell with clamped or free ends under the cases of lower number waves.

A systematic review and meta-analysis of racial/ethnic differences and similarities in executive function performance in the United States.

The extent that executive function performance varies between racial/ethnic groups in the United States is unclear, limiting future studies on the problems underlying these differences. The aim of this meta-analysis was to test two competing hypotheses: The cultural differences hypothesis asserts large differences between Whites and racial/ethnic minorities in the U.S., and small differences between- (e.g., African Americans, Latinos) and within- (e.g., Latinos: Mexican Americans, Cuban Americans) minority groups. The cultural similarities hypothesis posits small differences between Whites and minorities, and these differences are equal or smaller in magnitude than differences between- and within-minorities on executive function performance. We also tested moderators of these differences. We focused on overall executive functioning performance and its three core components: inhibitory control, working memory, and cognitive flexibility.. A systematic search on PsycINFO, Web of Science, ERIC, PubMed, and ProQuest Dissertations and Theses Global identified 46 records (17% unpublished; 38 independent samples) with 56,067 total participants (Mage = 44.48 years; range = 3.05-80.45; 52% female; 39.5% racial/ethnic minority). Absolute differences between Whites and minorities (d = 0.85, 95% CI [0.65, 1.05]) were larger in magnitude compared to between-minorities (d = 0.44, 95% CI [0.28, 0.60]) and within-minorities (d = 0.09, 95% CI [0.03, 0.15]). White-minority differences were moderated by type of executive function measure and year of data collection. Post hoc analyses revealed large relative differences between some groups but not others. Findings support the cultural differences hypothesis for executive function performance. This meta-analysis underscores the need to address social inequalities in the U.S. that drive performance differences. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Revealing the Complex Relationships Between Ethnicity and Health: 29 Outcomes From the Scottish Health and Ethnicity Linkage Study (SHELS) Cohort

Objectives: To present a data visualization approach based on epidemiological principles that can be used to illustrate the complexity of health inequalities by ethnicity. Methods: We provide an example of our technique by presenting results from the Scottish Health and Ethnicity Linkage Study (SHELS) on 29 different health outcomes across ten ethnic groups. SHELS is a census-based retrospective cohort study of the general population of Scotland (4.62 million people) linking ethnicity data to health records. We employed different colors to show health advantage, disadvantage or equivalence; different color shades to represent degree of certainty, combining effect size and precision of estimate; and different font sizes for absolute rates, to highlight more common conditions. We ranked health conditions by age-adjusted rate within each ethnic group to identify differences in burden of disease. Results: Data visualization clearly demonstrates that ethnic differences in health vary substantially depending on outcome, sex and ethnic group. Inequalities were present for every outcome but were not uniformly worse for non-White populations. The patterns are also complex within each ethnic group such as the Pakistani population where strong advantage for some outcomes (e.g. RR=0.52 in men for all-cause mortality) coexists with strong disadvantage for others (e.g. RR=1.80 in women for cardiovascular disease). Despite large differences in relative disease rates, ranking conditions within ethnic groups showed that most ethnic groups have similar disease priorities. Conclusions: Our approach demonstrates the complexity of ethnic differences in health. The use of these simple data visualization techniques can facilitate interpretation of this complexity and avoid misleading generalizations that the health of ethnic minorities is worse or better than majority populations. Using absolute rates of disease and ranking conditions within ethnic groups is also useful as large relative differences in rates of disease between ethnic groups may not always translate into different disease priorities.

Visualising the complex relationships between ethnic group and health in Scotland: 2001-2013

Abstract Background With growing numbers of migrants worldwide, accurate data are needed to assess the health of migrants and ethnic minorities, highlight inequalities and evaluate relevant policies and actions. To summarise and reveal the complexity of the findings, we developed data visualisation techniques based on epidemiological principles. Methods We used published results from the Scottish Health and Ethnicity Linkage Study (SHELS), a retrospective cohort of 4.62 million people linking census ethnicity data to health service and death records during 2001-2013. In tables mainly using rate ratios, we employed different colours to show health advantage, disadvantage or equivalence; different colour shades to represent degree of certainty, combining effect size and precision of estimate; and different font sizes for absolute rates, to highlight more common conditions. We ranked health conditions by age-adjusted rate within each ethnic group to show differences in burden of disease and disease priorities. Results Using 30 health outcomes for up to 11 ethnic groups, we show that ethnic differences vary greatly depending on outcome, sex and ethnic group. The patterns are complex with some ethnic groups showing strong advantages for some outcomes and strong disadvantages for others. Using absolute rates highlighted differences in common conditions such as myocardial infarction, COPD, and falls. Ranking conditions within ethnic groups showed that most ethnic groups have largely similar disease priorities. Conclusions Our approach helps reveal and interpret the complexity of ethnic health differences. Simplistic generalisations that the health of migrants or ethnic minorities is worse or better than majority populations are often misleading and best avoided. Using absolute rates and ranking conditions within ethnic groups are useful as large relative differences in disease rates between ethnic groups may not translate into different disease priorities. Key messages Statements that the health of migrants or ethnic minorities is worse or better than majority populations are often misleading and best avoided. Large relative differences in disease rates between ethnic groups may not translate into different disease priorities.

MAX-DOAS observations of aerosols, formaldehyde and nitrogen dioxide in the Beijing area: comparison of two profile retrieval approaches

Abstract. A 4-year data set of MAX-DOAS observations in the Beijing area (2008–2012) is analysed with a focus on NO2, HCHO and aerosols. Two very different retrieval methods are applied. Method A describes the tropospheric profile with 13 layers and makes use of the optimal estimation method. Method B uses 2–4 parameters to describe the tropospheric profile and an inversion based on a least-squares fit. For each constituent (NO2, HCHO and aerosols) the retrieval outcomes are compared in terms of tropospheric column densities, surface concentrations and "characteristic profile heights" (i.e. the height below which 75% of the vertically integrated tropospheric column density resides). We find best agreement between the two methods for tropospheric NO2 column densities, with a standard deviation of relative differences below 10%, a correlation of 0.99 and a linear regression with a slope of 1.03. For tropospheric HCHO column densities we find a similar slope, but also a systematic bias of almost 10% which is likely related to differences in profile height. Aerosol optical depths (AODs) retrieved with method B are 20% high compared to method A. They are more in agreement with AERONET measurements, which are on average only 5% lower, however with considerable relative differences (standard deviation ~ 25%). With respect to near-surface volume mixing ratios and aerosol extinction we find considerably larger relative differences: 10 ± 30, −23 ± 28 and −8 ± 33% for aerosols, HCHO and NO2 respectively. The frequency distributions of these near-surface concentrations show however a quite good agreement, and this indicates that near-surface concentrations derived from MAX-DOAS are certainly useful in a climatological sense. A major difference between the two methods is the dynamic range of retrieved characteristic profile heights which is larger for method B than for method A. This effect is most pronounced for HCHO, where retrieved profile shapes with method A are very close to the a priori, and moderate for NO2 and aerosol extinction which on average show quite good agreement for characteristic profile heights below 1.5 km. One of the main advantages of method A is the stability, even under suboptimal conditions (e.g. in the presence of clouds). Method B is generally more unstable and this explains probably a substantial part of the quite large relative differences between the two methods. However, despite a relatively low precision for individual profile retrievals it appears as if seasonally averaged profile heights retrieved with method B are less biased towards a priori assumptions than those retrieved with method A. This gives confidence in the result obtained with method B, namely that aerosol extinction profiles tend on average to be higher than NO2 profiles in spring and summer, whereas they seem on average to be of the same height in winter, a result which is especially relevant in relation to the validation of satellite retrievals.

Radiation-induced second primary cancer risks from modern external beam radiotherapy for early prostate cancer: impact of stereotactic ablative radiotherapy (SABR), volumetric modulated arc therapy (VMAT) and flattening filter free (FFF) radiotherapy

Risks of radiation-induced second primary cancer following prostate radiotherapy using 3D-conformal radiotherapy (3D-CRT), intensity-modulated radiotherapy (IMRT), volumetric modulated arc therapy (VMAT), flattening filter free (FFF) and stereotactic ablative radiotherapy (SABR) were evaluated. Prostate plans were created using 10 MV 3D-CRT (78 Gy in 39 fractions) and 6 MV 5-field IMRT (78 Gy in 39 fractions), VMAT (78 Gy in 39 fractions, with standard flattened and energy-matched FFF beams) and SABR (42.7 Gy in 7 fractions with standard flattened and energy-matched FFF beams). Dose-volume histograms from pelvic planning CT scans of three prostate patients, each planned using all 6 techniques, were used to calculate organ equivalent doses (OED) and excess absolute risks (EAR) of second rectal and bladder cancers, and pelvic bone and soft tissue sarcomas, using mechanistic, bell-shaped and plateau models. For organs distant to the treatment field, chamber measurements recorded in an anthropomorphic phantom were used to calculate OEDs and EARs using a linear model. Ratios of OED give relative radiation-induced second cancer risks.SABR resulted in lower second cancer risks at all sites relative to 3D-CRT. FFF resulted in lower second cancer risks in out-of-field tissues relative to equivalent flattened techniques, with increasing impact in organs at greater distances from the field. For example, FFF reduced second cancer risk by up to 20% in the stomach and up to 56% in the brain, relative to the equivalent flattened technique. Relative to 10 MV 3D-CRT, 6 MV IMRT or VMAT with flattening filter increased second cancer risks in several out-of-field organs, by up to 26% and 55%, respectively. For all techniques, EARs were consistently low. The observed large relative differences between techniques, in absolute terms, were very low, highlighting the importance of considering absolute risks alongside the corresponding relative risks, since when absolute risks are very low, large relative risks become less meaningful.A calculated relative radiation-induced second cancer risk benefit from SABR and FFF techniques was theoretically predicted, although absolute radiation-induced second cancer risks were low for all techniques, and absolute differences between techniques were small.

Inferring Attribute Non-attendance from Discrete Choice Experiments: Implications for Benefit Transfer

Typical convergent validity tests of benefit transfer based on stated preference data assume that willingness to pay (WTP) estimates have been accurately measured, and that differences in WTP arise from differences in observable and unobservable characteristics between the study and the policy sites. In this paper, we conduct a convergent validity test assuming equality of underlying preferences, but allow for the possibility that transfer errors arise from differences in the way that respondents process information in the preference elicitation tasks. Using data from an identical survey instrument applied to the population of two river basins in Spain, we obtain marginal and total WTP estimates for ecological improvements of water bodies and the corresponding transfer errors across sites. Results of equality constrained latent class (ECLC) models that infer attribute non-attendance (AN-A) are compared to results from mixed logit (MXL) models in WTP space. We find large absolute and relative differences in marginal and total WTP between sites for the MXL models, and significantly reduced transfer errors for the ECLC models. This paper therefore provides further evidence that AN-A can significantly affect environmental values derived from attribute-based stated preference methods and is the first to investigate the implications for benefit transfer.

Non-Boussinesq gravity currents propagating on different bottom slopes

AbstractExperiments on the non-Boussinesq gravity currents generated from an instantaneous buoyancy source propagating on an inclined boundary in the slope angle range $0^{\circ } \le \theta \le 9^{\circ }$ with relative density difference in the range of $0.05 \le \epsilon \le 0.17$ are reported, where $\epsilon = (\rho _1-\rho _0)/\rho _0$, with $\rho _1$ and $\rho _0$ the densities of the heavy and light ambient fluids, respectively. We showed that a $3/2$ power-law, ${(x_f+x_0)}^{3/2}= K_M^{3/2} {B_0'}^{1/2} (t+t_{I0})$, exists between the front location measured from the virtual origin, $(x_f+x_0)$, and time, $t$, in the early deceleration phase for both the Boussinesq and non-Boussinesq cases, where $K_M$ is a measured empirical constant, $B_0'$ is the total released buoyancy, and $t_{I0}$ is the $t$-intercept. Our results show that $K_M$ not only increases as the relative density difference increases but also assumes its maximum value at $\theta \approx 6^{\circ }$ for sufficiently large relative density differences. In the late deceleration phase, the front location data deviate from the $3/2$ power-law and the flow patterns on $\theta =6^{\circ },9^{\circ }$ slopes are qualitatively different from those on $\theta =0^{\circ },2^{\circ }$. In the late deceleration phase, we showed that viscous effects could become more important and another power-law, ${(x_f+x_0)}^{2}= K_{V}^{2} {B_0'}^{2/3} {{A}^{1/3}_0} {\nu }^{-1/3} (t+t_{V0})$, applies for both the Boussinesq and non-Boussinesq cases, where $K_V$ is an empirical constant, $A_0$ is the initial volume of heavy fluid per unit width, $\nu $ is the kinematic viscosity of the fluids, and $t_{V0}$ is the $t$-intercept. Our results also show that $K_V$ increases as the relative density difference increases and $K_V$ assumes its maximum value at $\theta \approx 6^{\circ }$.

SPARC Data Initiative: A comparison of ozone climatologies from international satellite limb sounders

AbstractA comprehensive quality assessment of the ozone products from 18 limb‐viewing satellite instruments is provided by means of a detailed intercomparison. The ozone climatologies in form of monthly zonal mean time series covering the upper troposphere to lower mesosphere are obtained from LIMS, SAGE I/II/III, UARS‐MLS, HALOE, POAM II/III, SMR, OSIRIS, MIPAS, GOMOS, SCIAMACHY, ACE‐FTS, ACE‐MAESTRO, Aura‐MLS, HIRDLS, and SMILES within 1978–2010. The intercomparisons focus on mean biases of annual zonal mean fields, interannual variability, and seasonal cycles. Additionally, the physical consistency of the data is tested through diagnostics of the quasi‐biennial oscillation and Antarctic ozone hole. The comprehensive evaluations reveal that the uncertainty in our knowledge of the atmospheric ozone mean state is smallest in the tropical and midlatitude middle stratosphere with a 1σ multi‐instrument spread of less than ±5%. While the overall agreement among the climatological data sets is very good for large parts of the stratosphere, individual discrepancies have been identified, including unrealistic month‐to‐month fluctuations, large biases in particular atmospheric regions, or inconsistencies in the seasonal cycle. Notable differences between the data sets exist in the tropical lower stratosphere (with a spread of ±30%) and at high latitudes (±15%). In particular, large relative differences are identified in the Antarctic during the time of the ozone hole, with a spread between the monthly zonal mean fields of ±50%. The evaluations provide guidance on what data sets are the most reliable for applications such as studies of ozone variability, model‐measurement comparisons, detection of long‐term trends, and data‐merging activities.

Bimanual coordination in children: manipulation of object distance

The performance of many everyday activities requires the coordination of the two upper limbs to achieve the goal of the task. Although bimanual performance has been studied in detail in adults, few studies have examined how children coordinate the movements of the two hands during symmetric and asymmetric bimanual prehension. With the current study, we asked younger (4-6 years, n = 14) and older (7-10 years, n = 16) children to complete a discrete bimanual task. Specifically, they reached to grasp cylinders located at near and far positions in either unimanual or bimanual condition. During bimanual symmetric conditions, participants performed movements with both hands toward two objects located at the same distance (both near or both far), while in the bimanual asymmetric conditions, they reached for objects at different distances. Results of the kinematic analyses indicated that the young children consistently experienced the "two target" effect, whereby bimanual movements were executed more slowly than unimanual movements to the same distance. Older children employed a hybrid strategy, exhibiting slower movements in bimanual congruent conditions, but larger non-dominant apertures in bimanual incongruent conditions. This hybrid strategy was hypothesized to stem from developmental changes occurring in the integration of sensory information around 8 years of age. While older children exhibited temporal and spatial coordination patterns that were similar to patterns reported in adults, large relative timing differences at the start and end of bimanual movements and considerably weaker spatial coupling were seen in the younger children.

Transition state theory thermal rate constants and RRKM-based branching ratios for the N(2D) + CH4reaction based on multi-sState and multi-referenceAb Initiocalculations of interest for the titan's chemistry

Multireference single and double configuration interaction (MRCI) calculations including Davidson (+Q) or Pople (+P) corrections have been conducted in this work for the reactants, products, and extrema of the doublet ground state potential energy surface involved in the N((2)D) + CH(4) reaction. Such highly correlated ab initio calculations are then compared with previous PMP4, CCSD(T), W1, and DFT/B3LYP studies. Large relative differences are observed in particular for the transition state in the entrance channel resolving the disagreement between previous ab initio calculations. We confirm the existence of a small but positive potential barrier (3.86 ± 0.84 kJ mol(-1) (MR-AQCC) and 3.89 kJ mol(-1) (MRCI+P)) in the entrance channel of the title reaction. The correlation is seen to change significantly the energetic position of the two minima and five saddle points of this system together with the dissociation channels but not their relative order. The influence of the electronic correlation into the energetic of the system is clearly demonstrated by the thermal rate constant evaluation and it temperature dependance by means of the transition state theory. Indeed, only MRCI values are able to reproduce the experimental rate constant of the title reaction and its behavior with temperature. Similarly, product branching ratios, evaluated by means of unimolecular RRKM theory, confirm the NH production of Umemoto et al., whereas previous works based on less accurate ab initio calculations failed. We confirm the previous findings that the N((2)D) + CH(4) reaction proceeds via an insertion-dissociation mechanism and that the dominant product channels are CH(2)NH + H and CH(3) + NH.