Hydraulic validation of two-dimensional simulations of braided river flow with spatially continuous aDcp data

Gravel‐bed braided rivers are characterized by shallow, branching flow across low relief, complex, and mobile bed topography. These conditions present a major challenge for the application of higher dimensional hydraulic models, the predictions of which are nevertheless vital to inform flood risk and ecosystem management. This paper demonstrates how high‐resolution topographic survey and hydraulic monitoring at a density commensurate with model discretization can be used to advance hydrodynamic simulations in braided rivers. Specifically, we detail applications of the shallow water model, Delft3d, to the Rees River, New Zealand, at two nested scales: a 300 m braid bar unit and a 2.5 km reach. In each case, terrestrial laser scanning was used to parameterize the topographic boundary condition at hitherto unprecedented resolution and accuracy. Dense observations of depth and velocity acquired from a mobile acoustic Doppler current profiler (aDcp), along with low‐altitude aerial photography, were then used to create a data‐rich framework for model calibration and testing at a range of discharges. Calibration focused on the estimation of spatially uniform roughness and horizontal eddy viscosity, νH, through comparison of predictions with distributed hydraulic data. Results revealed strong sensitivity to νH, which influenced cross‐channel velocity and localization of high shear zones. The high‐resolution bed topography partially accounts for form resistance, and the recovered roughness was found to scale by 1.2–1.4 D84 grain diameter. Model performance was good for a range of flows, with minimal bias and tight error distributions, suggesting that acceptable predictions can be achieved with spatially uniform roughness and νH.Field campaigns were primarily funded by NERC Grant NE/G005427/1 and NERC Geophysical Equipment Facility Loan 892 as well as NSERC and CFI (Canada) grants to Colin Rennie. Damia Vericat was supported by a Ramon y Cajal Fellowship (RYC‐2010‐06264) funded by the Spanish Ministry of Science and Innovation during the preparation of this manuscript. Numerical simulations were undertaken during a visit by Richard Williams to NIWA. This visit was funded by the British Hydrology Society and an Aberystwyth University Postgraduate Studentship. Murray Hicks and Richard Measures were funded by NIWA core funding under the Sustainable Water Allocation Programme

Modelling Braided River Morphodynamics Using a Particle Travel Length Framework

Numerical models that predict channel evolution are an essential tool for investigating processes that occur over timescales which render field observation intractable. The current generation of morphodynamic models, however, either oversimplify the relevant physical processes or, in the case of more physically complete codes based on computational fluid dynamics (CFD), have computational overheads that severely restrict the space–time scope of their application. Here we present a new, open-source, hybrid approach that seeks to reconcile these modelling philosophies. This framework combines steady-state, two-dimensional CFD hydraulics with a rule-based sediment transport algorithm to predict particle mobility and transport paths which are used to route sediment and evolve the bed topography. Data from two contrasting natural braided rivers (Rees, New Zealand, and Feshie, United Kingdom) were used for model verification, incorporating reach-scale quantitative morphological change budgets and volumetric assessment of different braiding mechanisms. The model was able to simulate 8 of the 10 empirically observed braiding mechanisms from the parameterized bed erosion, sediment transport, and deposition. Representation of bank erosion and bar edge trimming necessitated the inclusion of a lateral channel migration algorithm. Comparisons between simulations based on steady effective discharge versus event hydrographs discretized into a series of model runs were found to only marginally increase the predicted volumetric change, with greater deposition offsetting erosion. A decadal-scale simulation indicates that accurate prediction of event-scale scour depth and subsequent deposition present a methodological challenge because the predicted pattern of deposition may never “catch up” to erosion if a simple path-length distribution is employed, thus resulting in channel over-scouring. It may thus be necessary to augment path-length distributions to preferentially deposit material in certain geomorphic units. We anticipate that the model presented here will be used as a modular framework to explore the effect of different process representations, and as a learning tool designed to reveal the relative importance of geomorphic transport processes in rivers at multiple timescales

Repository Corticotropin Injection for Active Rheumatoid Arthritis Despite Aggressive Treatment: A Randomized Controlled Withdrawal Trial.

INTRODUCTION: The objective of this study was to assess efficacy and safety of repository corticotropin injection (RCI) in subjects with active rheumatoid arthritis (RA) despite treatment with a corticosteroid and one or two disease-modifying antirheumatic drugs (DMARDs). METHODS: All subjects received open-label RCI (80 U) twice weekly for 12 weeks (part 1); only those with low disease activity [LDA; i.e., Disease Activity Score 28 joint count and erythrocyte sedimentation rate (DAS28-ESR) \u3c 3.2] were randomly assigned to receive either RCI (80 U) or placebo twice weekly during the 12-week double-blind period (part 2). The primary efficacy endpoint was the proportion of subjects who achieved LDA at week 12. Secondary efficacy endpoints included proportions of subjects who maintained LDA during weeks 12 through 24 and achieved Clinical Disease Activity Index (CDAI) ≤ 10 at weeks 12 and 24. Safety was assessed via adverse event reports. RESULTS: Of the 259 enrolled subjects, 235 completed part 1; 154 subjects (n = 77 each for RCI and placebo) entered part 2, and 127 (RCI, n = 71; placebo, n = 56) completed. At week 12, 163 subjects (62.9%) achieved LDA and 169 (65.3%) achieved CDAI ≤ 10 (both p \u3c 0.0001). At week 24, 47 (61.0%) RCI-treated and 32 (42.1%) placebo-treated subjects maintained LDA (p = 0.019); 66 (85.7%) RCI-treated and 50 (65.8%) placebo-treated subjects maintained CDAI ≤ 10 (p = 0.004). No unexpected safety signals were observed. CONCLUSIONS: RCI was effective and generally safe in patients with active RA despite corticosteroid/DMARD therapy. By week 12, \u3e 60% of patients achieved LDA, which was maintained with 12 additional weeks of treatment. Most patients who achieved LDA maintained it for 3 months after RCI discontinuation. TRIAL REGISTRATION: Clinicaltrials.gov identifier NCT02919761

A Pilot Study to Determine Whether Disability and Disease Activity Are Different in African-American and Caucasian Patients with Rheumatoid Arthritis in

ABSTRACT. Objective. To compare the levels of disability and disease activity in African-Americans and Caucasians with rheumatoid arthritis (RA) in an academic medical center practice, and to determine whether the differences are independently associated with ethnicity. Methods. Data on socioeconomic, disease related, psychological, and behavioral variables were obtained from 100 outpatients (67 Caucasians, 33 African-Americans) with RA. Functional status was assessed with the Health Assessment Questionnaire (HAQ) and Disease Activity Score (DAS-28). Chi-square and Student t tests were used to test for differences between groups. Multiple regression analysis was used to determine whether ethnicity was associated with these differences independent of other factors known to influence disease outcome. Results. African-Americans and Caucasians did not differ with respect to age, sex, disease duration, rheumatoid factor positivity, and medication compliance. African-Americans had higher scores than Caucasians for HAQ (1.5 ± 0.8 vs 0.9 ± 0.7; p < 0.001) and DAS-28 (5.5 ± 1.3 vs 4.3 ± 1.4; p < 0.001). Regression models showed that ethnicity was not independently associated with the higher HAQ and DAS-28 scores when controlled for demographic, socioeconomic, psychological, and behavioral factors. Arthritis self-efficacy approaches significance in the regression model. Conclusion. HAQ disability and RA disease activity were higher in African-Americans than Caucasians in this sample from an academic medical center practice. However, ethnicity was not independently associated with these outcomes when socioeconomic and psychological factors were taken into account. Improvement in self-efficacy has the potential to improve outcome in AfricanAmericans with RA. (J Rheumatol 2005;32:602-8

Associations of cigarette smoking with rheumatoid arthritis in African Americans

To examine the associations of cigarette smoking with rheumatoid arthritis (RA) in African Americans and to determine to whether this association is impacted by HLA-DRB1 shared epitope (SE)

Towards implementation of robust monitoring technologies alongside freshwater improvement policy in Aotearoa New Zealand

International studies point out that some freshwater policy objectives are not achieved. This study describes that this is in part caused by shortcomings that include: the lack of targeted monitoring schemes to measure impact; a too small range of specific technologies rather than a wider suite of integrated multiple technologies; a too tight focus on sub-sets of stakeholders instead of the involvement of the wider range of end users; and poor trust building and technology explanations to end users. As an example, the New Zealand government is addressing widespread concern over the deterioration of the national freshwater resource by supporting a diverse portfolio of land and riparian management actions. Efforts to assess the effectiveness of these interventions and establish an evidence-based framework for future policies are however limited by the existing regional-scale freshwater monitoring infrastructure. Such hydrometric networks were established largely to assess the broader-scale regional ‘state’ of the environment and are generally out-of-phase with freshwater improvement actions that are implemented more typically at edge-of-field, farm or sub-catchment scales. Recent and rapid evolution in sensor technologies have created new opportunities to deliver information tuned to the appropriate parameters and frequencies needed to evaluate improvement actions. Despite this, the necessary transformative change in freshwater monitoring has yet to gather pace. In this study we explore barriers and solutions with the objective to better understand what is needed for successful integration of innovative monitoring technologies in a transitional environmental policy setting, using recent New Zealand policy directives as a case study. We use expert surveys and scenario testing to explore barriers to adoption to more robust and comprehensive monitoring required to establish the success, or otherwise, of freshwater improvement actions. This process reveals that rather than further innovations in technology, change in the practice of environmental monitoring is limited instead by the development of defensible and accepted guidelines on the application and effective deployment of existing sensors and methods. We demonstrate that improved knowledge exchange between engineers, scientists and practitioners can be addressed and propose a new decision support and communication tool to enable the selection of monitoring technologies and solutions fit-for-purpose to evaluate freshwater improvement outcomes on multiple scales involving multiple stakeholders

Complementary and Alternative Medicine Use in African Americans With Rheumatoid Arthritis: Prevalence of CAM in an African American Cohort

Racial/ethnic differences with regard to complementary and alternative medicine (CAM) use have been reported in the US. However, specific details of CAM use by African Americans with rheumatoid arthritis (RA) are lacking

Most Common SNPs Associated with Rheumatoid Arthritis in Subjects of European Ancestry Confer Risk of Rheumatoid Arthritis in African-Americans

Large-scale genetic association studies have identified over 20 rheumatoid arthritis (RA) risk alleles among individuals of European ancestry. The influence of these risk alleles has not been comprehensively studied in African-Americans. We therefore sought to examine whether these validated RA risk alleles are associated with RA in an African-American population

An African Ancestry-Specific Allele of CTLA4 Confers Protection against Rheumatoid Arthritis in African Americans

Cytotoxic T-lymphocyte associated protein 4 (CTLA4) is a negative regulator of T-cell proliferation. Polymorphisms in CTLA4 have been inconsistently associated with susceptibility to rheumatoid arthritis (RA) in populations of European ancestry but have not been examined in African Americans. The prevalence of RA in most populations of European and Asian ancestry is ∼1.0%; RA is purportedly less common in black Africans, with little known about its prevalence in African Americans. We sought to determine if CTLA4 polymorphisms are associated with RA in African Americans. We performed a 2-stage analysis of 12 haplotype tagging single nucleotide polymorphisms (SNPs) across CTLA4 in a total of 505 African American RA patients and 712 African American controls using Illumina and TaqMan platforms. The minor allele (G) of the rs231778 SNP was 0.054 in RA patients, compared to 0.209 in controls (4.462×10−26, Fisher's exact). The presence of the G allele was associated with a substantially reduced odds ratio (OR) of having RA (AG+GG genotypes vs. AA genotype, OR 0.19, 95% CI: 0.13–0.26, p = 2.4×10−28, Fisher's exact), suggesting a protective effect. This SNP is polymorphic in the African population (minor allele frequency [MAF] 0.09 in the Yoruba population), but is very rare in other groups (MAF = 0.002 in 530 Caucasians genotyped for this study). Markers associated with RA in populations of European ancestry (rs3087243 [+60C/T] and rs231775 [+49A/G]) were not replicated in African Americans. We found no confounding of association for rs231778 after stratifying for the HLA-DRB1 shared epitope, presence of anti-cyclic citrullinated peptide antibody, or degree of admixture from the European population. An African ancestry-specific genetic variant of CTLA4 appears to be associated with protection from RA in African Americans. This finding may explain, in part, the relatively low prevalence of RA in black African populations

Radiographic severity of Rheumatoid Arthritis in African Americans: Results from a multicenter observational study

To describe radiographic changes in African-Americans with rheumatoid arthritis (RA) from the CLEAR (Consortium for the Longitudinal Evaluation of African-Americans with Early Rheumatoid Arthritis) Registry, a multicenter observational study